This study systematically introduces the development of the world’s first full-link and full-system ground demonstration and verification system for the OMEGA space solar power satellite(SSPS).First,the OMEGA 2.0 inn...This study systematically introduces the development of the world’s first full-link and full-system ground demonstration and verification system for the OMEGA space solar power satellite(SSPS).First,the OMEGA 2.0 innovation design was proposed.Second,field-coupling theoretical models of sunlight concentration,photoelectric conversion,and transmitting antennas were established,and a systematic optimization design method was proposed.Third,a beam waveform optimization methodology considering both a high beam collection efficiency and a circular stepped beam shape was proposed.Fourth,a control strategy was developed to control the condenser pointing toward the sun while maintaining the transmitting antenna toward the rectenna.Fifth,a high-efficiency heat radiator design method based on bionics and topology optimization was proposed.Sixth,a method for improving the rectenna array’s reception,rectification,and direct current(DC)power synthesis efficiencies is presented.Seventh,high-precision measurement technology for high-accuracy beam-pointing control was developed.Eighth,a smart mechanical structure was designed and developed.Finally,the developed SSPS ground demonstration and verification system has the capacity for sun tracking,a high concentration ratio,photoelectric conversion,microwave conversion and emission,microwave reception,and rectification,and thus satisfactory results were obtained.展开更多
A novel scheme for generating optical chaos is proposed and experimentally demonstrated,which supports to simultaneously produce two low-correlation chaotic signals with wideband spectrum and suppressed time-delay-sig...A novel scheme for generating optical chaos is proposed and experimentally demonstrated,which supports to simultaneously produce two low-correlation chaotic signals with wideband spectrum and suppressed time-delay-signature(TDS).In the proposed scheme,we use the output of an external-cavity semiconductor laser(ECSL)as the driving signal of a phase modulator to modulate the output of a CW laser.Then the phase-modulated continuous-wave(CW)light is split into two parts,one is injected back into the ECSL that outputs one chaotic signal,while the other part is passed through a dispersion module for generating another chaotic signal simultaneously.The experimental results prove that the proposed scheme has three merits.Firstly,it can improve the bandwidth of ECSL-based chaos by several times,and simultaneously generate another wideband flat-spectrum chaotic signal.Secondly,the undesired TDS characteristics of the simultaneously-generated chaotic signals can be efficiently suppressed to an indistinguishable level within a wide parameter range,as such the complexities of the chaotic signals are considerably high.Thirdly,the correlation coefficient between these two simultaneously-generated chaotic signals is smaller than 0.1.The proposed scheme provides an attractive solution for parallel multiple chaos generation,and shows great potential for multiple channel chaos communications and multiple random bit generations.展开更多
This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular...This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.展开更多
In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple...In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple independent PV arrays.In each PV array,there are multiple independent PV subarrays.In this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV array.This method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this paper.When the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed proportionally.The principle and control method of the proposed droop control method is analyzed in this paper.The effectiveness of the method is verified through MATLAB/Simulink simulation and experiment.Simulation and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.展开更多
We propose and numerically demonstrate a photonic computing primitive designed for integrated spiking neural networks (SNNs) based on add-drop ring microresonators (ADRMRs) and electrically reconfigurable phasechange ...We propose and numerically demonstrate a photonic computing primitive designed for integrated spiking neural networks (SNNs) based on add-drop ring microresonators (ADRMRs) and electrically reconfigurable phasechange material (PCM) photonic switches. In this neuromorphic system, the passive silicon-based ADRMR,equipped with a power-tunable auxiliary light, effectively demonstrates nonlinearity-induced dual neural dynamics encompassing spiking response and synaptic plasticity that can generate single-wavelength optical neural spikes with synaptic weight. By cascading these ADRMRs with different resonant wavelengths, weighted multiple-wavelength spikes can be feasibly output from the ADRMR-based hardware arrays when external wavelengthaddressable optical pulses are injected;subsequently, the cumulative power of these weighted output spikes is utilized to ascertain the activation status of the reconfigurable PCM photonic switches. Moreover, the reconfigurable mechanism driving the interconversion of the PCMs between the resonant-bonded crystalline states and the covalent-bonded amorphous states is achieved through precise thermal modulation. Drawing from the thermal properties, an innovative thermodynamic leaky integrate-and-firing (TLIF) neuron system is proposed. With the TLIF neuron system as the fundamental unit, a fully connected SNN is constructed to complete a classic deep learning task:the recognition of handwritten digit patterns. The simulation results reveal that the exemplary SNN can effectively recognize 10 numbers directly in the optical domain by employing the surrogate gradient algorithm. The theoretical verification of our architecture paves a whole new path for integrated photonic SNNs, with the potential to advance the field of neuromorphic photonic systems and enable more efficient spiking information processing.展开更多
Natural tactile sensation is complex,which involves not only contact force intensity detection but also the perception of the force direction,the surface texture,and other mechanical parameters.Nevertheless,the vast m...Natural tactile sensation is complex,which involves not only contact force intensity detection but also the perception of the force direction,the surface texture,and other mechanical parameters.Nevertheless,the vast majority of the developed tactile sensors can only detect the normal force,but usually cannot resolve shear force or even distinguish the directions of the force.Here,we present a new paradigm of bioinspired tactile sensors for resolving both the intensity and the directions of mechanical stimulations via synergistic microcrack-bristle structure design and cross-shaped configuration engineering.The microcrack sensing structure gives high mechanical sensitivity to the tactile sensors,and the synergistic bristle structure further amplifies the sensitivity of the sensors.The cross-shaped configuration engineering of the synergistic microcrack-bristle structure further endows the tactile sensors with good capability to detect and distinguish the directions of the applied mechanical forces.The as-fabricated tactile sensors exhibit a high sensitivity(25.76 N^(−1)),low detection limit(5.4 mN),desirable stability(over 2,500 cycles),and good capability to resolve both mechanical intensity and directional features.As promising application scenarios,surface texture recognition and biomimetic path explorations are successfully demonstrated with these tactile sensors.This newly proposed tactile sensation strategy and technology have great potential applications in ingenious tactile sensation and construction of various robotic and bionic prostheses with high operational dexterity.展开更多
Background:People with atrial fibrillation(AF)have elevated risk of developing cognitive impairment.At present,there is a dearth of randomized controlled trials investigating cognitive impairment management in patient...Background:People with atrial fibrillation(AF)have elevated risk of developing cognitive impairment.At present,there is a dearth of randomized controlled trials investigating cognitive impairment management in patients with AF.The Atrial Fibrillation Follow-up Investigation to Recover Memory and learning(AFFIRMING)study is aimed at evaluating the potential for computerized cognitive training to improve cognitive function in patients with AF.Methods:The study is a multi-center,double-blind,randomized controlled study using a 1:1 parallel design.A total of 200 patients with AF and mild cognitive decline without dementia are planned to be recruited.The intervention group will use the adaptive training software with changes in difficulty,whereas the positive control group will use basic training software with minimal or no variation in difficulty level.At the end of 12 weeks,the participants will be unblinded,and the positive control group will stop training.The intervention group will be rerandomized 1:1 to stop training or continue training.All participants will be followed up until 24 weeks.The primary endpoint is the propor-tion of the improvement of the global cognitive function at week 12 compared with baseline,using the Basic Cognitive Ability Test(BCAT).展开更多
Background:Statins,a first-line therapeutic option for atherosclerotic cardiovascular disease(ASCVD),have prompted concerns regarding dysglycemia and diabetes,thus posing a dilemma in treating patients with prediabete...Background:Statins,a first-line therapeutic option for atherosclerotic cardiovascular disease(ASCVD),have prompted concerns regarding dysglycemia and diabetes,thus posing a dilemma in treating patients with prediabetes.Xuezhikang(XZK)decreases blood cholesterol levels without affecting glucose metabolism,and may serve as a potential substitute.Methods:The XTREME study is a prospective,randomized,open-label,multi-center trial evaluating whether XZK 1200 mg/d,compared with atorvastatin 20 mg/d,has favorable effects on HbA1c levels after 24 weeks of treatment in patients with dyslipidemia and prediabetes.After a 1-week run-in period for adherence assessment,the study will ran-domly assign(1:1)392 patients meeting the protocol inclusion criteria to one of two treatment groups:an experimental group(XZK 1200 mg/day)or a control group(atorvastatin 20 mg/day).All participants will be recruited from approxi-mately 20 Chinese medical centers.The last participant is planned to be recruited before December 2023.The primary endpoint will be change in HbA1c level from baseline to 24 weeks,or before anti-diabetic therapy initiation within 24 weeks.The key secondary outcomes will include other biomarkers reflecting blood glucose or lipid metabolism.Discussion:Delaying diabetes is desirable for individuals with prediabetes.The XTREME trial presents a unique oppor-tunity to demonstrate whether XZK might provide an alternative to statins for patients with dyslipidemia and prediabetes.展开更多
OBJECTIVE： To explore the regulatory effects of es- tablished Chinese herbal formulas on inflammatory mediators released during asthma attacks, and to elucidate the molecular mechanism of Traditional Chinese Medicine...OBJECTIVE： To explore the regulatory effects of es- tablished Chinese herbal formulas on inflammatory mediators released during asthma attacks, and to elucidate the molecular mechanism of Traditional Chinese Medicine in the treatment of asthma. METHODS： Seventy-five asthmatic children were randomly divided into a Chinese medication group （45 cases） and a Western medication control group （30 cases）. Patients in the Chinese medication group were treated with a series of established Chi- nese herbal formulas, whereas the Western medica- tion control group received a leukotriene receptor antagonist and a bronchial relaxant. Real-time PCR was used to determine the mRNA expression levels of interleukin （IL）-4, cysteinyl leukotriene receptor 1 （CysLTR1）, and interferon （IFN）-γ in peripheralblood mononuclear cells before and after treat- ment. Enzyme-linked immunosorbent assay was used to measure the peripheral blood levels of IL-4, leukotriene （LTE）-4, and INF-γ before and after treat- ment. RESULTS： After treatment, the mRNA expression levels of 11-4 and CysLTR1 were down-regulated （P〈 0.01） and the mRNA expression levels of IFN-γ were up-regulated （P〈0.05） in the Chinese medication and Western medication groups; no significant dif- ference was found between the two groups. In the Chinese medication group, IL-4 blood level was de- creased and it was significantly different from that in the Western medication group （P〈0.05）; there was also a significant increase in IFN-γ blood levels after treatment with Chinese medica- tion （P〈0.05）. There were no significant differenc- es in LTE-4 blood levels between the two groups before and after treatment （P〉0.05）. CONCLUSION： Chinese medication has a regulato- ry effect on leukotriene receptor gene expression and the imbalance of Th1/Th2 immune cells dur- ing asthma attacks in pediatric patients.展开更多
The irreversible motion of magnetic domain walls in ferromagnets can dissipate a large portion of the elastic energy,and the associated damping capacity is proportional to the magnetostriction constant.In contrast,her...The irreversible motion of magnetic domain walls in ferromagnets can dissipate a large portion of the elastic energy,and the associated damping capacity is proportional to the magnetostriction constant.In contrast,here we found that the damping capacity of the large magnetostriction Fe-Ga alloys can be enhanced by 2-3 times through introducing structural defects including interfacial dislocations and stacking faults,despite that these defects deteriorate the magnetostriction.These structural defects were introduced by aging the BCC(body-centered-cubic)solution-treated precursor,for which the formation of mechanically harder FCT(face-centered-tetragonal)and/or FCC(face-centered-cubic)phases can result in high-density partial dislocations at the semi-coherent phase interfaces and quasi-periodically stacked nano-layer substructure inside the FCC variants.The structural defects act as extra damping sources besides the magnetic domain walls because the structural accommodation of the semi-coherent phase interfaces between BCC and FCT/FCC nanoprecipitates with different elastic moduli and the nano-layer substructure towards long-range ordered periodical stacking can dissipate a large portion of mechanical energy.These findings suggest that introducing structural defects provides fresh freedom to design high damping ferromagnetic materials.展开更多
Introduction:The development of coal power base(CPB)poses a severe challenge to the soil.We conducted a soil survey in Xilinhot CPB,to evaluate and analyze the pollution characteristics,potential ecological risk,and s...Introduction:The development of coal power base(CPB)poses a severe challenge to the soil.We conducted a soil survey in Xilinhot CPB,to evaluate and analyze the pollution characteristics,potential ecological risk,and sources of six heavy metals(As,Pb,Cu,Zn,Mn,and Cd)in soil by using Geo-accumulation index,revised Nemerow integrated pollution index(RNIPI),and potential ecological risk index(RI).Outcomes/other:The results showed that the pollution of Cd and As were dramatic.The mean of Cd and As were 1.11 mg·kg^(-1) and 25.13 mg·kg^(-1),which were 42.55 times and 4.41 times higher than its local background value.The Geo-accumulation indices showed the contamination degree of Cd was strong and As was moderate,and the status of Cu,Pb,Zn,and Mn were uncontaminated.Xilinhot was strongly contaminated based on its RNIPI and RI values.Discussion:The accumulations of As,Pb,and Cd were mainly associated with anthropogenic sources,including coal mining and combustion,and industrial exhaust emissions.Cu,Mn,and Zn were primarily originated from the parent material(natural sources).Conclusion:This study provides scientific basis and effective countermeasures for the prevention and control of soil pollution in surrounding areas of CPB.展开更多
Space Solar Power Station(SSPS)is a giant spacecraft to collect space solar energy and transmit electric energy to the ground by using the wireless transmission technology.As a concentrated space solar power station,S...Space Solar Power Station(SSPS)is a giant spacecraft to collect space solar energy and transmit electric energy to the ground by using the wireless transmission technology.As a concentrated space solar power station,SSPS via the Orb-shape Membrane Energy Gathering Array(OMEGA)system is comprised of the concentrator subsystem,the photovoltaic array subsystem and the transmitting antenna subsystem.In this manuscript,the comprehensive study on the coordinate kinematic among subsystems is carried out.Firstly,kinematic analysis and dynamic analysis are conducted.Secondly,under the condition of ideal attitude,the influence of the moving condition of the Photovoltaic(PV)array on the overall system is studied.Finally,the control ability for the deviation attitude caused by the acceleration process of the photovoltaic array is studied.The simulation results demonstrate the serious influence of the angular acceleration of the photovoltaic array on the system’s attitude and the validity of the designed attitude control system.展开更多
Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications.Due to the chaotic bandwid...Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications.Due to the chaotic bandwidth limitation resulting from intrinsic relaxation oscillation frequency of lasers,multiplexing of optical chaotic signal,such as wavelength division multiplexing in fiber,is a typical candidate for high-capacity secure applications.However,to our best knowledge,the utilization of the spatial dimension of optical chaos for free-space secure communication has not yet been reported.Here,we experimentally demonstrate a free-space all-optical chaotic communication system that simultaneously enhances transmission capacity and security by orbital angular momentum(OAM)multiplexing.Optical chaotic signals with two different OAM modes totally carrying 20 Gbps on-off keying signals are secretly transmitted over a 2 m free-space link,where the channel crosstalk of OAM modes is less than-20 d B,with the mode spacing no less than 3.The receiver can extract valid information only when capturing approximately 92.5% of the OAM beam and correctly demodulating the corresponding mode.Bit error rate below the 7%hard-decision forward error correction threshold of 3.8×10^(-3)can be achieved for the intended recipient.Moreover,a simulated weak turbulence is introduced to comprehensively analyze the influence on the system performance,including channel crosstalk,chaotic synchronization,and transmission performance.Our work may inspire structured light application in optical chaos and pave a new way for developing future high-capacity free-space chaotic secure communication systems.展开更多
Cable-net structures are of substantial importance in the construction of large mesh reflector antennas.Owing to the inevitable errors in their manufacturing process,the reflector surface accuracy deteriorates.This st...Cable-net structures are of substantial importance in the construction of large mesh reflector antennas.Owing to the inevitable errors in their manufacturing process,the reflector surface accuracy deteriorates.This study makes a comprehensive investigation of random manufacturing errors during constructing the mesh reflector antennas,and analyze its influence on reflector surface accuracy.Firstly,the sensitivity of reflector surface accuracy with respect to the random errors of the unstressed cable length is mathematically deducted.Secondly,a non-button connecting method is proposed and analyzed to reduce manufacturing errors.Thirdly,two physical experiment models based on 2.62-meter mesh reflector antenna are made.Finally,numerical examples and experimental tests are given to demonstrate the effectiveness of the proposed method.Compared with the traditional method,the proposed method can effectively reduce the influence of the manufacturing errors on the reflector surface accuracy.Moreover,the reduction in the sizes of the nodes also reduces the risk of entanglement of the mesh reflector antenna during the deployment process,and thereby improves the deployment reliability.展开更多
Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compare...Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing.Methods：This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant.Twenty-one patients came to the 1-month follow-up visit.Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode.For these patients,sensor response factors were left at default settings （ACC =8,MV =3） and sensor indicated rates （SIRs） for DS,ACC and MV sensor were retrieved from the pacemaker memories,along with measured sinus node （SN） rates from the beginning to 1-minute after the end of the treadmill test,and compared among study groups.Repeated measures analysis of variance and profile analysis,as well as variance analysis of randomized block designs,were used for statistical analysis.Results：Fifteen patients （15/2 l） were determined to be chronotropically competent.The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor （mean difference between SIR and SN rate：ACC vs.SN,MV vs.SN,DS vs.SN,respectively,34.84,17.60,16.15 beats/min）,though no sensors could mimic sinus rates under the default settings for sensor response factor （ACC vs.SN P-adjusted 〈 0.001; MV vs.SN P-adjusted =0.002; DS vs.SN P-adjusted =0.005）.However,both in the range of 1st minute and first 3 minutes of exercise,only the DS SIR profile did not differ from sinus rates （P-adjusted =0.09,0.90,respectively）.Conclusions：The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors （ACC or MV sensor）.Further study is needed to determine if individual optimization would further improve adaptive performance of the DS.展开更多
OBJECTIVE:To establish a quantification model of Traditional Chinese Medicine(TCM)syndromes by sampling patients undergoing idiopathic precocious puberty(IPP)and early puberty.METHODS:A questionnaire for classifying a...OBJECTIVE:To establish a quantification model of Traditional Chinese Medicine(TCM)syndromes by sampling patients undergoing idiopathic precocious puberty(IPP)and early puberty.METHODS:A questionnaire for classifying and quantifying TCM syndromes was designed and administered.All the results were analyzed;the relationship between 3 types of syndrome and 47symptoms were summated.Meanwhile,the frequency distribution of each symptom or sign was aggregated.Fuzzy mathematics was used to develop a quantification model ofTCM syndromes.RESULTS:We found that precocious puberty had 3types of syndrome,including hyperactivity of fire due to Yin deficiency(Syndrome I),depressed liver Qi transforming into fire(Syndrome II),and end retention of damp heat(Syndrome III).In the IPP group,Syndrome I was the most common principal syndrome(100%).Forty-six patients(43.81%)werediagnosed with Syndrome I accompanied by Syndrome II and 11(10.48%)were diagnosed with Syndrome I accompanied by Syndrome III.In the early puberty group,Syndrome I was also the main syndrome(98.39%).The degrees of most symptoms were mild to moderate.Reddened tongue was the most common tongue manifestation(62.86%prevalence)in the IPP group.The most common pulse manifestations were slippery pulse,thread pulse,and taut pulse.The Asymptotic Normalization Coefficient(ANC)method was used to quantify the TCM syndromes in 167 cases.Diagnostic accuracy rate reached 91%,comparable to expert diagnosis.CONCLUSION:We find that there are 3 types of syndrome in the IPP group and in the early puberty group.Syndrome I(hyperactivity of fire due to Yin deficiency)is the main syndrome in the two groups.ANC may be an appropriate for quantification model ofTCM syndromes.展开更多
We consider semantic image segmentation.Our method is inspired by Bayesian deep learning which improves image segmentation accuracy by modeling the uncertainty of the network output.In contrast to uncertainty,our meth...We consider semantic image segmentation.Our method is inspired by Bayesian deep learning which improves image segmentation accuracy by modeling the uncertainty of the network output.In contrast to uncertainty,our method directly learns to predict the erroneous pixels of a segmentation network,which is modeled as a binary classification problem.It can speed up training comparing to the Monte Carlo integration often used in Bayesian deep learning.It also allows us to train a branch to correct the labels of erroneous pixels.Our method consists of three stages:(i)predict pixel-wise error probability of the initial result,(ii)redetermine new labels for pixels with high error probability,and(iii)fuse the initial result and the redetermined result with respect to the error probability.We formulate the error-pixel prediction problem as a classification task and employ an error-prediction branch in the network to predict pixel-wise error probabilities.We also introduce a detail branch to focus the training process on the erroneous pixels.We have experimentally validated our method on the Cityscapes and ADE20K datasets.Our model can be easily added to various advanced segmentation networks to improve their performance.Taking DeepLabv3+as an example,our network can achieve 82.88%of mloU on Cityscapes testing dataset and 45.73%on ADE20K validation dataset,improving corresponding DeepLabv3+results by 0.74%and 0.13%respectively.展开更多
Zigzag carbon nanobelts are a long-sought-after yet unrealized target for organic synthesis.Herein,we report a study toward the synthesis of tetrabenzo[10]cyclacene,an undocumented zigzag carbon nanobelt.The synthetic...Zigzag carbon nanobelts are a long-sought-after yet unrealized target for organic synthesis.Herein,we report a study toward the synthesis of tetrabenzo[10]cyclacene,an undocumented zigzag carbon nanobelt.The synthetic precursor of tetrabenzo[10]cyclacene is its box-shaped tetraepoxy derivative,which is synthesized through iterative Diels–Alder reactions utilizing a“C”-shaped building block.Attempted aromatization of this tetraepoxy nanobox toward the formation of a fully conjugated nanobelt results in an octahydro derivative of tetrabenzo[10]cyclacene.The structures of the tetraepoxy nanobox and octahydrotetrabenzo[10]cyclacene were both unambiguously identified with single-crystal X-ray crystallography.展开更多
Protein-RNA interaction networks are essential to understand gene regulation control. Identifying binding sites of RNA-binding proteins （RBPs） by the UV-crosslinking and immunoprecipitation （CLIP） represents one o...Protein-RNA interaction networks are essential to understand gene regulation control. Identifying binding sites of RNA-binding proteins （RBPs） by the UV-crosslinking and immunoprecipitation （CLIP） represents one of the most powerful methods to map protein RNA interactions in vivo. However, the traditional CLIP protocol is technically challenging, which requires radioactive labeling and suffers from material loss during PAGE-membrane transfer procedures. Here we introduce a super-efficient CLIP method （GoldCLIP） that omits all gel purification steps. This nonisotopic method allows us to perform highly reproducible CLIP experiments with polypyrimidine tract-binding protein （PTB）, a classical RBP in human cell lines. In principle, our method guarantees sequencing library constructions, providing the protein of interest can be successfully crosslinked to RNAs in living cells. GoldCLIP is readily applicable to diverse proteins to uncover their endogenous RNA targets.展开更多
文摘This study systematically introduces the development of the world’s first full-link and full-system ground demonstration and verification system for the OMEGA space solar power satellite(SSPS).First,the OMEGA 2.0 innovation design was proposed.Second,field-coupling theoretical models of sunlight concentration,photoelectric conversion,and transmitting antennas were established,and a systematic optimization design method was proposed.Third,a beam waveform optimization methodology considering both a high beam collection efficiency and a circular stepped beam shape was proposed.Fourth,a control strategy was developed to control the condenser pointing toward the sun while maintaining the transmitting antenna toward the rectenna.Fifth,a high-efficiency heat radiator design method based on bionics and topology optimization was proposed.Sixth,a method for improving the rectenna array’s reception,rectification,and direct current(DC)power synthesis efficiencies is presented.Seventh,high-precision measurement technology for high-accuracy beam-pointing control was developed.Eighth,a smart mechanical structure was designed and developed.Finally,the developed SSPS ground demonstration and verification system has the capacity for sun tracking,a high concentration ratio,photoelectric conversion,microwave conversion and emission,microwave reception,and rectification,and thus satisfactory results were obtained.
基金This work was supported by the National Natural Science Foundation of China(Grant no.62171087,61671119)the Sichuan Science and Technology Program(Grant no.2021JDJQ0023)the Fundamental Research Funds for the Central Universities(Grant no.ZYGX2019J003).
文摘A novel scheme for generating optical chaos is proposed and experimentally demonstrated,which supports to simultaneously produce two low-correlation chaotic signals with wideband spectrum and suppressed time-delay-signature(TDS).In the proposed scheme,we use the output of an external-cavity semiconductor laser(ECSL)as the driving signal of a phase modulator to modulate the output of a CW laser.Then the phase-modulated continuous-wave(CW)light is split into two parts,one is injected back into the ECSL that outputs one chaotic signal,while the other part is passed through a dispersion module for generating another chaotic signal simultaneously.The experimental results prove that the proposed scheme has three merits.Firstly,it can improve the bandwidth of ECSL-based chaos by several times,and simultaneously generate another wideband flat-spectrum chaotic signal.Secondly,the undesired TDS characteristics of the simultaneously-generated chaotic signals can be efficiently suppressed to an indistinguishable level within a wide parameter range,as such the complexities of the chaotic signals are considerably high.Thirdly,the correlation coefficient between these two simultaneously-generated chaotic signals is smaller than 0.1.The proposed scheme provides an attractive solution for parallel multiple chaos generation,and shows great potential for multiple channel chaos communications and multiple random bit generations.
基金supported in part by the National Key Research and Development Program of China(2021YFB3900300)in part by the National Natural Science Foundation of China(62201416)+2 种基金in part by the Fundamental Research Funds for the Central Universities(QTZX23070)in part by the Qin Chuang Yuan High-Level Innovative and Entrepreneurial Talents Project(QCYRCXM-2022-314)in part by Singapore Ministry of Education Academic Research Fund Tier 1。
文摘This work presents an optimal design method of antenna aperture illumination for microwave power transmission with an annular collection area.The objective is to maximize the ratio of the power radiated on the annular collection area to the total transmitted power.By formulating the aperture amplitude distribution through a summation of a special set of series,the optimal design problem can be reduced to finding the maximum ratio of two real quadratic forms.Based on the theory of matrices,the solution to the formulated optimization problem is to determine the largest characteristic value and its associated characteristic vector.To meet security requirements,the peak radiation levels outside the receiving area are considered to be extra constraints.A hybrid grey wolf optimizer and Nelder–Mead simplex method is developed to deal with this constrained optimization problem.In order to demonstrate the effectiveness of the proposed method,numerical experiments on continuous apertures are conducted;then,discrete arrays of isotropic elements are employed to validate the correctness of the optimized results.Finally,patch arrays are adopted to further verify the validity of the proposed method.
基金supported by the Civil Aerospace Technology Research Project,China(No.D010103)the National Natural Science Foundation of China(Nos.52022075 and U1937202)the National Key R&D Program of China(No.2021YFB3900300).
文摘In this paper,a multi-bus distributed Power Conditioning Unit(PCU)is proposed for the Space Solar Power Station with large scale photovoltaic(PV)array and power levels reaching MW level.In this unit,there are multiple independent PV arrays.In each PV array,there are multiple independent PV subarrays.In this paper,a V-P droop control method with adaptive droop coefficient is proposed,which modifies the droop intercept based on the bus voltage deviation and the power per unit value of the PV array.This method ensures the accuracy of bus voltage and achieves proportional distribution of power between PV arrays based on the proposed topology structure in this paper.When the load changes or the output power of the PV array fluctuates,this method can ensure that power is distributed proportionally.The principle and control method of the proposed droop control method is analyzed in this paper.The effectiveness of the method is verified through MATLAB/Simulink simulation and experiment.Simulation and experimental results show that the proposed method can achieve power distributed proportionally when load changes and PV output power fluctuates,reduce bus voltage error caused by line impedance and differences in rated power of different PV arrays,and improve the performance of PV power generation system applied to space.
基金National Natural Science Foundation of China(62171087)Sichuan Science and Technology Program(2021JDJQ0023)Fundamental Research Funds for the Central Universities (ZYGX2019J003)。
文摘We propose and numerically demonstrate a photonic computing primitive designed for integrated spiking neural networks (SNNs) based on add-drop ring microresonators (ADRMRs) and electrically reconfigurable phasechange material (PCM) photonic switches. In this neuromorphic system, the passive silicon-based ADRMR,equipped with a power-tunable auxiliary light, effectively demonstrates nonlinearity-induced dual neural dynamics encompassing spiking response and synaptic plasticity that can generate single-wavelength optical neural spikes with synaptic weight. By cascading these ADRMRs with different resonant wavelengths, weighted multiple-wavelength spikes can be feasibly output from the ADRMR-based hardware arrays when external wavelengthaddressable optical pulses are injected;subsequently, the cumulative power of these weighted output spikes is utilized to ascertain the activation status of the reconfigurable PCM photonic switches. Moreover, the reconfigurable mechanism driving the interconversion of the PCMs between the resonant-bonded crystalline states and the covalent-bonded amorphous states is achieved through precise thermal modulation. Drawing from the thermal properties, an innovative thermodynamic leaky integrate-and-firing (TLIF) neuron system is proposed. With the TLIF neuron system as the fundamental unit, a fully connected SNN is constructed to complete a classic deep learning task:the recognition of handwritten digit patterns. The simulation results reveal that the exemplary SNN can effectively recognize 10 numbers directly in the optical domain by employing the surrogate gradient algorithm. The theoretical verification of our architecture paves a whole new path for integrated photonic SNNs, with the potential to advance the field of neuromorphic photonic systems and enable more efficient spiking information processing.
基金the Sichuan Science and Technology Program(2022YFS0025)the project“Key Technologies and Applications of Sensitive Components for Pathogenic Microorganisms and Metabolic Markers of Misease”(2021YFB3201200)This work was also supported by the“Fundamental Research Funds for the Central Universities of China.”
文摘Natural tactile sensation is complex,which involves not only contact force intensity detection but also the perception of the force direction,the surface texture,and other mechanical parameters.Nevertheless,the vast majority of the developed tactile sensors can only detect the normal force,but usually cannot resolve shear force or even distinguish the directions of the force.Here,we present a new paradigm of bioinspired tactile sensors for resolving both the intensity and the directions of mechanical stimulations via synergistic microcrack-bristle structure design and cross-shaped configuration engineering.The microcrack sensing structure gives high mechanical sensitivity to the tactile sensors,and the synergistic bristle structure further amplifies the sensitivity of the sensors.The cross-shaped configuration engineering of the synergistic microcrack-bristle structure further endows the tactile sensors with good capability to detect and distinguish the directions of the applied mechanical forces.The as-fabricated tactile sensors exhibit a high sensitivity(25.76 N^(−1)),low detection limit(5.4 mN),desirable stability(over 2,500 cycles),and good capability to resolve both mechanical intensity and directional features.As promising application scenarios,surface texture recognition and biomimetic path explorations are successfully demonstrated with these tactile sensors.This newly proposed tactile sensation strategy and technology have great potential applications in ingenious tactile sensation and construction of various robotic and bionic prostheses with high operational dexterity.
基金funded by Capital’s Funds for Health Improvement and Research,grant/award number 2022-2-2067The trial is supported by the Science and Technology Foundation of Beijing Anzhen Hospital,Capital Medical University,grant/award number:KCGY2022.
文摘Background:People with atrial fibrillation(AF)have elevated risk of developing cognitive impairment.At present,there is a dearth of randomized controlled trials investigating cognitive impairment management in patients with AF.The Atrial Fibrillation Follow-up Investigation to Recover Memory and learning(AFFIRMING)study is aimed at evaluating the potential for computerized cognitive training to improve cognitive function in patients with AF.Methods:The study is a multi-center,double-blind,randomized controlled study using a 1:1 parallel design.A total of 200 patients with AF and mild cognitive decline without dementia are planned to be recruited.The intervention group will use the adaptive training software with changes in difficulty,whereas the positive control group will use basic training software with minimal or no variation in difficulty level.At the end of 12 weeks,the participants will be unblinded,and the positive control group will stop training.The intervention group will be rerandomized 1:1 to stop training or continue training.All participants will be followed up until 24 weeks.The primary endpoint is the propor-tion of the improvement of the global cognitive function at week 12 compared with baseline,using the Basic Cognitive Ability Test(BCAT).
文摘Background:Statins,a first-line therapeutic option for atherosclerotic cardiovascular disease(ASCVD),have prompted concerns regarding dysglycemia and diabetes,thus posing a dilemma in treating patients with prediabetes.Xuezhikang(XZK)decreases blood cholesterol levels without affecting glucose metabolism,and may serve as a potential substitute.Methods:The XTREME study is a prospective,randomized,open-label,multi-center trial evaluating whether XZK 1200 mg/d,compared with atorvastatin 20 mg/d,has favorable effects on HbA1c levels after 24 weeks of treatment in patients with dyslipidemia and prediabetes.After a 1-week run-in period for adherence assessment,the study will ran-domly assign(1:1)392 patients meeting the protocol inclusion criteria to one of two treatment groups:an experimental group(XZK 1200 mg/day)or a control group(atorvastatin 20 mg/day).All participants will be recruited from approxi-mately 20 Chinese medical centers.The last participant is planned to be recruited before December 2023.The primary endpoint will be change in HbA1c level from baseline to 24 weeks,or before anti-diabetic therapy initiation within 24 weeks.The key secondary outcomes will include other biomarkers reflecting blood glucose or lipid metabolism.Discussion:Delaying diabetes is desirable for individuals with prediabetes.The XTREME trial presents a unique oppor-tunity to demonstrate whether XZK might provide an alternative to statins for patients with dyslipidemia and prediabetes.
基金Supported by Major Research Project of Shanghai Traditional Chinese Medicine Three-year Action Plan(ZYSNXD-CC-ZDYJ034)Shanghai Science and Technology Research Grant Program(No.12401905500)Shanghai Health Bureau Medical Research Fund Grant Program(No.2006L032A)
文摘OBJECTIVE： To explore the regulatory effects of es- tablished Chinese herbal formulas on inflammatory mediators released during asthma attacks, and to elucidate the molecular mechanism of Traditional Chinese Medicine in the treatment of asthma. METHODS： Seventy-five asthmatic children were randomly divided into a Chinese medication group （45 cases） and a Western medication control group （30 cases）. Patients in the Chinese medication group were treated with a series of established Chi- nese herbal formulas, whereas the Western medica- tion control group received a leukotriene receptor antagonist and a bronchial relaxant. Real-time PCR was used to determine the mRNA expression levels of interleukin （IL）-4, cysteinyl leukotriene receptor 1 （CysLTR1）, and interferon （IFN）-γ in peripheralblood mononuclear cells before and after treat- ment. Enzyme-linked immunosorbent assay was used to measure the peripheral blood levels of IL-4, leukotriene （LTE）-4, and INF-γ before and after treat- ment. RESULTS： After treatment, the mRNA expression levels of 11-4 and CysLTR1 were down-regulated （P〈 0.01） and the mRNA expression levels of IFN-γ were up-regulated （P〈0.05） in the Chinese medication and Western medication groups; no significant dif- ference was found between the two groups. In the Chinese medication group, IL-4 blood level was de- creased and it was significantly different from that in the Western medication group （P〈0.05）; there was also a significant increase in IFN-γ blood levels after treatment with Chinese medica- tion （P〈0.05）. There were no significant differenc- es in LTE-4 blood levels between the two groups before and after treatment （P〉0.05）. CONCLUSION： Chinese medication has a regulato- ry effect on leukotriene receptor gene expression and the imbalance of Th1/Th2 immune cells dur- ing asthma attacks in pediatric patients.
基金supported by the National Natural Science Foundation of China(Nos.51871174,52071256,and 51831006)the State Key Laboratory of Solidification Processing in NPU(No.SKLSP202003)the State Key Laboratory for Mechanical Behavior of Materials(No.2019016)。
文摘The irreversible motion of magnetic domain walls in ferromagnets can dissipate a large portion of the elastic energy,and the associated damping capacity is proportional to the magnetostriction constant.In contrast,here we found that the damping capacity of the large magnetostriction Fe-Ga alloys can be enhanced by 2-3 times through introducing structural defects including interfacial dislocations and stacking faults,despite that these defects deteriorate the magnetostriction.These structural defects were introduced by aging the BCC(body-centered-cubic)solution-treated precursor,for which the formation of mechanically harder FCT(face-centered-tetragonal)and/or FCC(face-centered-cubic)phases can result in high-density partial dislocations at the semi-coherent phase interfaces and quasi-periodically stacked nano-layer substructure inside the FCC variants.The structural defects act as extra damping sources besides the magnetic domain walls because the structural accommodation of the semi-coherent phase interfaces between BCC and FCT/FCC nanoprecipitates with different elastic moduli and the nano-layer substructure towards long-range ordered periodical stacking can dissipate a large portion of mechanical energy.These findings suggest that introducing structural defects provides fresh freedom to design high damping ferromagnetic materials.
基金This work was supported by the National Key Research and Development Program of China[2016YFC0501101,2016YFC0503603].
文摘Introduction:The development of coal power base(CPB)poses a severe challenge to the soil.We conducted a soil survey in Xilinhot CPB,to evaluate and analyze the pollution characteristics,potential ecological risk,and sources of six heavy metals(As,Pb,Cu,Zn,Mn,and Cd)in soil by using Geo-accumulation index,revised Nemerow integrated pollution index(RNIPI),and potential ecological risk index(RI).Outcomes/other:The results showed that the pollution of Cd and As were dramatic.The mean of Cd and As were 1.11 mg·kg^(-1) and 25.13 mg·kg^(-1),which were 42.55 times and 4.41 times higher than its local background value.The Geo-accumulation indices showed the contamination degree of Cd was strong and As was moderate,and the status of Cu,Pb,Zn,and Mn were uncontaminated.Xilinhot was strongly contaminated based on its RNIPI and RI values.Discussion:The accumulations of As,Pb,and Cd were mainly associated with anthropogenic sources,including coal mining and combustion,and industrial exhaust emissions.Cu,Mn,and Zn were primarily originated from the parent material(natural sources).Conclusion:This study provides scientific basis and effective countermeasures for the prevention and control of soil pollution in surrounding areas of CPB.
基金co-supported by the National Natural Science Foundation of China(Nos.51775404,U1637207,51607131)the Qian Xuesen Laboratory of Space Technology Seed Fund(No.QXSZZJJ03-08)+1 种基金the Natural Science Foundation of Shaanxi Provincial Department of Education,China(No.19JK0848)the Natural Science Foundation of Shaanxi Province,China(No.2020JQ-595)。
文摘Space Solar Power Station(SSPS)is a giant spacecraft to collect space solar energy and transmit electric energy to the ground by using the wireless transmission technology.As a concentrated space solar power station,SSPS via the Orb-shape Membrane Energy Gathering Array(OMEGA)system is comprised of the concentrator subsystem,the photovoltaic array subsystem and the transmitting antenna subsystem.In this manuscript,the comprehensive study on the coordinate kinematic among subsystems is carried out.Firstly,kinematic analysis and dynamic analysis are conducted.Secondly,under the condition of ideal attitude,the influence of the moving condition of the Photovoltaic(PV)array on the overall system is studied.Finally,the control ability for the deviation attitude caused by the acceleration process of the photovoltaic array is studied.The simulation results demonstrate the serious influence of the angular acceleration of the photovoltaic array on the system’s attitude and the validity of the designed attitude control system.
基金National Natural Science Foundation of China(62105338,62171087)Sichuan Science and Technology Program(2021JDJQ0023,2021ZYCD001)+1 种基金Fundamental Research Funds for the Central Universities(ZYGX2019J003)Science and Technology Commission of Shanghai Municipality(SKLSFO2020-05)。
文摘Optical chaotic signals emitted from an external-cavity feedback or injected laser diode enable small-signal information concealment in a noise-like carrier for secure optical communications.Due to the chaotic bandwidth limitation resulting from intrinsic relaxation oscillation frequency of lasers,multiplexing of optical chaotic signal,such as wavelength division multiplexing in fiber,is a typical candidate for high-capacity secure applications.However,to our best knowledge,the utilization of the spatial dimension of optical chaos for free-space secure communication has not yet been reported.Here,we experimentally demonstrate a free-space all-optical chaotic communication system that simultaneously enhances transmission capacity and security by orbital angular momentum(OAM)multiplexing.Optical chaotic signals with two different OAM modes totally carrying 20 Gbps on-off keying signals are secretly transmitted over a 2 m free-space link,where the channel crosstalk of OAM modes is less than-20 d B,with the mode spacing no less than 3.The receiver can extract valid information only when capturing approximately 92.5% of the OAM beam and correctly demodulating the corresponding mode.Bit error rate below the 7%hard-decision forward error correction threshold of 3.8×10^(-3)can be achieved for the intended recipient.Moreover,a simulated weak turbulence is introduced to comprehensively analyze the influence on the system performance,including channel crosstalk,chaotic synchronization,and transmission performance.Our work may inspire structured light application in optical chaos and pave a new way for developing future high-capacity free-space chaotic secure communication systems.
基金supported by the National Natural Science Foundations of China(Nos.52022075,U1937202,&52175246)the Fundamental Research Funds for the Central Universities(Nos.QTZX2188&QTZX2173)。
文摘Cable-net structures are of substantial importance in the construction of large mesh reflector antennas.Owing to the inevitable errors in their manufacturing process,the reflector surface accuracy deteriorates.This study makes a comprehensive investigation of random manufacturing errors during constructing the mesh reflector antennas,and analyze its influence on reflector surface accuracy.Firstly,the sensitivity of reflector surface accuracy with respect to the random errors of the unstressed cable length is mathematically deducted.Secondly,a non-button connecting method is proposed and analyzed to reduce manufacturing errors.Thirdly,two physical experiment models based on 2.62-meter mesh reflector antenna are made.Finally,numerical examples and experimental tests are given to demonstrate the effectiveness of the proposed method.Compared with the traditional method,the proposed method can effectively reduce the influence of the manufacturing errors on the reflector surface accuracy.Moreover,the reduction in the sizes of the nodes also reduces the risk of entanglement of the mesh reflector antenna during the deployment process,and thereby improves the deployment reliability.
文摘Background：Dual sensor （DS） for rate adaption was supposed to be more physiological.To evaluate its superiority,the DS （accelerometer [ACC] and minute ventilation [MV]） and normal sinus rate response were compared in a self-controlled way during exercise treadmill testing.Methods：This self-controlled study was performed in atrioventricular block patients with normal sinus function who met the indications of pacemaker implant.Twenty-one patients came to the 1-month follow-up visit.Patients performed a treadmill test 1-month post implant while programmed in DDDR and sensor passive mode.For these patients,sensor response factors were left at default settings （ACC =8,MV =3） and sensor indicated rates （SIRs） for DS,ACC and MV sensor were retrieved from the pacemaker memories,along with measured sinus node （SN） rates from the beginning to 1-minute after the end of the treadmill test,and compared among study groups.Repeated measures analysis of variance and profile analysis,as well as variance analysis of randomized block designs,were used for statistical analysis.Results：Fifteen patients （15/2 l） were determined to be chronotropically competent.The mean differences between DS SIRs and intrinsic sinus rates during treadmill testing were smaller than those for ACC and MV sensor （mean difference between SIR and SN rate：ACC vs.SN,MV vs.SN,DS vs.SN,respectively,34.84,17.60,16.15 beats/min）,though no sensors could mimic sinus rates under the default settings for sensor response factor （ACC vs.SN P-adjusted 〈 0.001; MV vs.SN P-adjusted =0.002; DS vs.SN P-adjusted =0.005）.However,both in the range of 1st minute and first 3 minutes of exercise,only the DS SIR profile did not differ from sinus rates （P-adjusted =0.09,0.90,respectively）.Conclusions：The DS under default settings provides more physiological rate response during physical activity than the corresponding single sensors （ACC or MV sensor）.Further study is needed to determine if individual optimization would further improve adaptive performance of the DS.
基金Supported by the National Natural Science Foundation of China(No.81072841)the Shanghai Science and Technology Research Grant Program(No.09dZ1971600)State Key Clinical Department of TCM pediatrics
文摘OBJECTIVE:To establish a quantification model of Traditional Chinese Medicine(TCM)syndromes by sampling patients undergoing idiopathic precocious puberty(IPP)and early puberty.METHODS:A questionnaire for classifying and quantifying TCM syndromes was designed and administered.All the results were analyzed;the relationship between 3 types of syndrome and 47symptoms were summated.Meanwhile,the frequency distribution of each symptom or sign was aggregated.Fuzzy mathematics was used to develop a quantification model ofTCM syndromes.RESULTS:We found that precocious puberty had 3types of syndrome,including hyperactivity of fire due to Yin deficiency(Syndrome I),depressed liver Qi transforming into fire(Syndrome II),and end retention of damp heat(Syndrome III).In the IPP group,Syndrome I was the most common principal syndrome(100%).Forty-six patients(43.81%)werediagnosed with Syndrome I accompanied by Syndrome II and 11(10.48%)were diagnosed with Syndrome I accompanied by Syndrome III.In the early puberty group,Syndrome I was also the main syndrome(98.39%).The degrees of most symptoms were mild to moderate.Reddened tongue was the most common tongue manifestation(62.86%prevalence)in the IPP group.The most common pulse manifestations were slippery pulse,thread pulse,and taut pulse.The Asymptotic Normalization Coefficient(ANC)method was used to quantify the TCM syndromes in 167 cases.Diagnostic accuracy rate reached 91%,comparable to expert diagnosis.CONCLUSION:We find that there are 3 types of syndrome in the IPP group and in the early puberty group.Syndrome I(hyperactivity of fire due to Yin deficiency)is the main syndrome in the two groups.ANC may be an appropriate for quantification model ofTCM syndromes.
基金supported by the National Natural Science Foundation of China(No.61732016).
文摘We consider semantic image segmentation.Our method is inspired by Bayesian deep learning which improves image segmentation accuracy by modeling the uncertainty of the network output.In contrast to uncertainty,our method directly learns to predict the erroneous pixels of a segmentation network,which is modeled as a binary classification problem.It can speed up training comparing to the Monte Carlo integration often used in Bayesian deep learning.It also allows us to train a branch to correct the labels of erroneous pixels.Our method consists of three stages:(i)predict pixel-wise error probability of the initial result,(ii)redetermine new labels for pixels with high error probability,and(iii)fuse the initial result and the redetermined result with respect to the error probability.We formulate the error-pixel prediction problem as a classification task and employ an error-prediction branch in the network to predict pixel-wise error probabilities.We also introduce a detail branch to focus the training process on the erroneous pixels.We have experimentally validated our method on the Cityscapes and ADE20K datasets.Our model can be easily added to various advanced segmentation networks to improve their performance.Taking DeepLabv3+as an example,our network can achieve 82.88%of mloU on Cityscapes testing dataset and 45.73%on ADE20K validation dataset,improving corresponding DeepLabv3+results by 0.74%and 0.13%respectively.
基金This research was made possible as a result of generous grants from the Research Grants Council of Hong Kong(GRF 14300218)the Croucher Senior Research Fellowship.
文摘Zigzag carbon nanobelts are a long-sought-after yet unrealized target for organic synthesis.Herein,we report a study toward the synthesis of tetrabenzo[10]cyclacene,an undocumented zigzag carbon nanobelt.The synthetic precursor of tetrabenzo[10]cyclacene is its box-shaped tetraepoxy derivative,which is synthesized through iterative Diels–Alder reactions utilizing a“C”-shaped building block.Attempted aromatization of this tetraepoxy nanobox toward the formation of a fully conjugated nanobelt results in an octahydro derivative of tetrabenzo[10]cyclacene.The structures of the tetraepoxy nanobox and octahydrotetrabenzo[10]cyclacene were both unambiguously identified with single-crystal X-ray crystallography.
基金supported in part by grants from the Ministry of Science and Technology of China(Grant No.2017YFA0504200 to YY,Grant Nos.2012CB910502 and 2011CB966304 to JM)the National Natural Science Foundation of China(Grant Nos.91640105 and 31770875 to YY,Grant No.31230041 to JM,and Grant Nos.91640115 and 31670827 to YZ)
文摘Protein-RNA interaction networks are essential to understand gene regulation control. Identifying binding sites of RNA-binding proteins （RBPs） by the UV-crosslinking and immunoprecipitation （CLIP） represents one of the most powerful methods to map protein RNA interactions in vivo. However, the traditional CLIP protocol is technically challenging, which requires radioactive labeling and suffers from material loss during PAGE-membrane transfer procedures. Here we introduce a super-efficient CLIP method （GoldCLIP） that omits all gel purification steps. This nonisotopic method allows us to perform highly reproducible CLIP experiments with polypyrimidine tract-binding protein （PTB）, a classical RBP in human cell lines. In principle, our method guarantees sequencing library constructions, providing the protein of interest can be successfully crosslinked to RNAs in living cells. GoldCLIP is readily applicable to diverse proteins to uncover their endogenous RNA targets.
