The superconducting magnet system of a fusion reactor plays a vital role in plasma confinement,a process that can be dis-rupted by various operational factors.A critical parameter for evaluating the temperature margin...The superconducting magnet system of a fusion reactor plays a vital role in plasma confinement,a process that can be dis-rupted by various operational factors.A critical parameter for evaluating the temperature margin of superconducting magnets during normal operation is the nuclear heating caused by D-T neutrons.This study investigates the impact of nuclear heat-ing on a superconducting magnet system by employing an improved analysis method that combines neutronics and thermal hydraulics.In the magnet system,toroidal field(TF)magnets are positioned closest to the plasma and bear the highest nuclear-heat load,making them prime candidates for evaluating the influence of nuclear heating on stability.To enhance the modeling accuracy and facilitate design modifications,a parametric TF model that incorporates heterogeneity is established to expedite the optimization design process and enhance the accuracy of the computations.A comparative analysis with a homogeneous TF model reveals that the heterogeneous model improves accuracy by over 12%.Considering factors such as heat load,magnetic-field strength,and cooling conditions,the cooling circuit facing the most severe conditions is selected to calculate the temperature of the superconductor.This selection streamlines the workload associated with thermal-hydraulic analysis.This approach enables a more efficient and precise evaluation of the temperature margin of TF magnets.Moreover,it offers insights that can guide the optimization of both the structure and cooling strategy of superconducting magnet systems.展开更多
AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectio...AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectional survey of diabetic patients in Subei district,China.Data covering physical measurements,fasting blood-glucose(FBG),glycosylated hemoglobin(Hb A1 c),blood lipid,urinary albumin/creatinine ratio(UACR),ocular fundus examination,and diabetes treatment records were collected.An independent sample t-test were used to analyze differences.A Logistic regression analysis was applied to study the independent risk factors of DR.RESULTS:A total of 1282 patients with type 2 DM were enrolled,and 191 cases had DR(14.9%).The age at diabetes onset,education level,alcohol consumption,Hb A1 c level,UACR level,and hypoglycemic drugs were independent influencing factors for DR.The older the onset of diabetes,the less likely to develop DR(OR:0.958,95%CI:0.942-0.975,P=0.000).Patients were then divided in terms of age at diabetes onset as follows:<50 y,50-59 y,60-69 y,and≥70 y.Compared with diabetes onset age<50 y,50-59 y(OR:0.463,95%CI:0.306-0.699,P=0.000),60-69 y(OR:0.329,95%CI:0.203-0.535,P=0.000)and≥70 y(OR:0.232,95%CI:0.094-0.577,P=0.002)were at a lower risk of DR.The prevalence of DR was highest in patients with diabetes onset age<50 y(29.5%,P<0.05).The Hb A1 c level(8.67±1.97)%and proportion of insulin injection(52.5%)in patients with diabetes onset<40 y were higher than in patients with older diabetes onset age(P<0.05).CONCLUSION:Diabetes onset at an earlier age and uncontrollable high Hb A1 c level could be independent risk factors for DR.展开更多
Phytochemicalinvestigation onthe whole plants of Ypsilandra yunnanensiswas carried out forthe firsttime andledtothe isolation of five new cholestanol glycosides,ypsiyunnosides A–E(1–5),and one known analogue.Their s...Phytochemicalinvestigation onthe whole plants of Ypsilandra yunnanensiswas carried out forthe firsttime andledtothe isolation of five new cholestanol glycosides,ypsiyunnosides A–E(1–5),and one known analogue.Their structures were determined mainly by detailed spectroscopic analysis,including extensive 1D and 2D NMR,MS and UV,as well as chemical methods.Among them,compound 1 possessed a rare 6/6/6/5/5 fused-rings cholestanol sketelon,which was identified as(23R,25R)-3β,16α,26-triol-16,23-cyclocholest-5,17(20)-dien-22-one.Their induced platelet aggregation activities and cytotoxicities were evaluated.Graphical Abstract Five new cholestanol glycosides,ypsiyunnosides A–E(1–5),were isolated from the whole plants of Ypsilandra yunnanensis.Compound 1 possessed a rare 6/6/6/5/5 fused-rings cholestanol sketelon.Their structures were elucidated by a combination of 1D and 2D NMR,MS and chemical analysis.展开更多
Rhizoma Paridis(RP,M®),a traditional Chinese medicine,is the rhizoma of Paris polyphylla var.yunnanensis(PPY)or P.polyphylla var.chinensis which are widely used as important raw materials for several Chinese pate...Rhizoma Paridis(RP,M®),a traditional Chinese medicine,is the rhizoma of Paris polyphylla var.yunnanensis(PPY)or P.polyphylla var.chinensis which are widely used as important raw materials for several Chinese patent drugs.However,the wild resources of these herbs have become less and less due to their slow-growing characteristics and previously excessive excavation.This review covers untiring investigations on alternative resources of RP by our research group over the past decades,including non-medicinal parts of PPY as well as other plants of Liliaceae and Liliflorae families.The arial parts of PPY and the whole plants of Trillium kamtschaticum might be alternative resources for RP based on the fact that they shared the same or similar saponins and bioactivities.展开更多
The whole plants of Ypsilandra thibetica have been analyzed as part of a systematic study on saponin constituents of medicinal plants.This has resulted in the isolation of two new bisdesmosidic furostanol saponins,nam...The whole plants of Ypsilandra thibetica have been analyzed as part of a systematic study on saponin constituents of medicinal plants.This has resulted in the isolation of two new bisdesmosidic furostanol saponins,named ypsilandroside P(1)and ypsilandroside Q(2),and one new pregnane glycoside,named ypsilandroside R(3),together with nine known steroidal glycosides.Their structures were elucidated on the basis of extensive spectroscopic analysis,including that of 2D NMR data,and the results of acidic hydrolysis.Ypsilandroside P(1)was cytotoxicity against two human tumor cell lines.展开更多
Phytochemical investigation of the rhizomes of Paris polyphylla var.stenophylla led to the isolation of two new highly oxygenated spirostanol saponins,named paristenosides A(1)and B(2),together with seven known compou...Phytochemical investigation of the rhizomes of Paris polyphylla var.stenophylla led to the isolation of two new highly oxygenated spirostanol saponins,named paristenosides A(1)and B(2),together with seven known compounds.Their structures were established mainly on the base of NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.In addition,the cytotoxicity of the two new saponins was tested.Graphical Abstract Two new highly oxygenated spirostanol saponins,paristenosides A(1)and B(2),were isolated from the rhizomes of Paris polyphylla var.stenophylla.Their structures were established mainly based on NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.展开更多
Two new monosaccharide steroidal saponins,named ypsilandroside S(1)and ypsilandroside T(2),have been isolated from the whole plants of Ypsilandra thibetica.Their structures were elucidated as heloniogenin 3-O-b-D-apio...Two new monosaccharide steroidal saponins,named ypsilandroside S(1)and ypsilandroside T(2),have been isolated from the whole plants of Ypsilandra thibetica.Their structures were elucidated as heloniogenin 3-O-b-D-apiofuranoside(1)and pregna 5,16-dien-3b,12a-diol-20-one-3-O-b-D-apiofuranoside(2)by spectroscopic techniques(1D and 2D NMR,MS).Compounds 1 and 2 were tested for their inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells.展开更多
BACKGROUNDPerioperative stroke is a rare but devastating complication. The risk factors formassive cerebral stroke in surgical patients include older age, male sex, priorcerebrovascular disease, hypertension, renal fa...BACKGROUNDPerioperative stroke is a rare but devastating complication. The risk factors formassive cerebral stroke in surgical patients include older age, male sex, priorcerebrovascular disease, hypertension, renal failure, smoking, diabetes mellitus,and atrial fibrillation.CASE SUMMARYWe describe two cases of perioperative massive cerebral stroke following thoracicsurgery and one case following bronchoscopy. Neurologic symptoms, includingchanges in mental status and hemiplegia, occurred within 10 h after surgery in thethree patients. All three patients died after the surgery.CONCLUSIONPerioperative massive cerebral stroke may be more likely to occur in thoracicsurgical patients if there are pre-existing factors including previous stroke,hypotension, and hypoxemia. Sufficient pain control after surgery and timelyneurology consultation and management are helpful for the diagnosis and controlof stroke in high-risk patients.展开更多
Phytochemical investigation of the MeOH extract of twigs and leaves of Baeckea frutescens led to the isolation of seven new polymethylated phloroglucinol meroterpenoids(PPMs),named baeckfrutones M-S(1-7).Their structu...Phytochemical investigation of the MeOH extract of twigs and leaves of Baeckea frutescens led to the isolation of seven new polymethylated phloroglucinol meroterpenoids(PPMs),named baeckfrutones M-S(1-7).Their structures and absolute configurations were determined by spectroscopic analyses,chiral-phase HPLC analysis,and electronic circular dichroism(ECD)calculations.PPM 1 is a novel meroterpenoid possessing a 6/6/5/3 tetracyclic skeleton in PPMs,whereas 3 and 4 are the first hydroxytasmanone type phloroglucinol-monoterpene hybrids.(+)-2 and 7 displayed potent antiinflammatory activity with IC50 values of 20.86±0.60 and 36.21±1.18 lL,respectively.展开更多
Two new eudesmane-type sesquiterpenoid lactones,named chlorelactone A(1)and chlorelactone B(2),and one new labdane-type diterpenoid,named elatiorlabdane(3),along with seven known sesquiterpenoids and one known disesqu...Two new eudesmane-type sesquiterpenoid lactones,named chlorelactone A(1)and chlorelactone B(2),and one new labdane-type diterpenoid,named elatiorlabdane(3),along with seven known sesquiterpenoids and one known disesquiterpenoid were isolated from the whole plants of Chloranthus elatior.Their structures and relative configurations were established on the basis of extensive spectroscopic analysis.展开更多
Phytochemical reinvestigation on the whole plants of Ypsilandra thibetica obtained four new spirostanol glycosides,named ypsilandrosides U-X(1-4),and one new cholestanol glycoside,named ypsilandroside Y(5).Their struc...Phytochemical reinvestigation on the whole plants of Ypsilandra thibetica obtained four new spirostanol glycosides,named ypsilandrosides U-X(1-4),and one new cholestanol glycoside,named ypsilandroside Y(5).Their structures have been established by extensive spectroscopic data and chemical methods.Among them,compound 4 is a rare spirostanol glycoside which possesses a novel 5(6→7)abeo-steroidal aglycone,while compound 1 is a first spiro-stanol bisdesmoside attached to C-3 and C-12,respectively,isolated from the genus Ypsilandra.The induced platelet aggregation activity of the isolates was tested.展开更多
Callisalignenes G–I(1–3),three new meroterpenoids of b-triketone and monoterpene,along with two known analogues(4 and 5),were isolated from Callistemon salignus.Their structures and absolute configurations were unam...Callisalignenes G–I(1–3),three new meroterpenoids of b-triketone and monoterpene,along with two known analogues(4 and 5),were isolated from Callistemon salignus.Their structures and absolute configurations were unambiguously established by a combination of NMR and MS analysis and electronic circular dichroism(ECD)evidence.Callisalignenes H(2)and I(3)have a rare sec-butyl moiety at C-7.Meroterpenoids 1–3 exhibited cytotoxicity against HCT116 cells with IC50 values of 8.51±1.8,9.12±0.3,and 16.33±3.3 lM,respectively.展开更多
Correction to:Natural Products and Bioprospecting(2018)8:431–439 https://doi.org/10.1007/s13659-018-0189-3 In the original publication,two errors have occurred.The corrected texts are provided below:1.The author,Xu-J...Correction to:Natural Products and Bioprospecting(2018)8:431–439 https://doi.org/10.1007/s13659-018-0189-3 In the original publication,two errors have occurred.The corrected texts are provided below:1.The author,Xu-Jie Qi,should read as Xu-Jie Qin among the author group.2.The reference 9 should be cited as X.J.Qin,Y.E.Zhi,H.Yan,Y.Zhang,H.Liu,Q.Yu,S.Wang,Q.Zhao,L.He,X.Ma,L.K.An,H.Y.Liu,Tetrahedron 74,6658–6666(2018).展开更多
We present a sample of 48 metal-poor galaxies at z 〈 0.14 selected from 92 510 galaxies in the LAMOST survey. These galaxies are identified by their detection of the auroral emission line[OⅢ]λ4363 above the 3σ lev...We present a sample of 48 metal-poor galaxies at z 〈 0.14 selected from 92 510 galaxies in the LAMOST survey. These galaxies are identified by their detection of the auroral emission line[OⅢ]λ4363 above the 3σ level, which allows a direct measurement of electron temperature and oxygen abundance. The emission line fluxes are corrected for internal dust extinction using the Balmer decrement method. With electron temperature derived from [OⅢ]λλ4959, 5007/[OⅢ]λ4363 and electron density from [SⅡ]λ6731/[SⅡ]λ6717, we obtain the oxygen abundances in our sample which range from 12 ＋ log（O/H） = 7.63（0.09 Z_⊙） to 8.46（0.6 Z_⊙）. We find an extremely metal-poor galaxy with 12 ＋ log（O/H） = 7.63 ± 0.01. With multiband photometric data from FUV to NIR and Hαmeasurements, we also determine the stellar masses and star formation rates, based on the spectral energy distribution fitting and Hα luminosity, respectively. We find that our galaxies have low and intermediate stellar masses with 6.39 ≤ log（M/M_⊙） ≤ 9.27, and high star formation rates（SFRs） with-2.18 ≤ log（SFR/M_⊙yr^（-1）） ≤ 1.95. We also find that the metallicities of our galaxies are consistent with the local T_e-based mass-metallicity relation, while the scatter is about 0.28 dex. Additionally,assuming the coefficient of α = 0.66, we find most of our galaxies follow the local mass-metallicity-SFR relation, but a scatter of about 0.24 dex exists, suggesting the mass-metallicity relation is weakly dependent on SFR for those metal-poor galaxies.展开更多
Applied field magnetoplasmadynamic thrusters(AF-MPDTs), with their high specific impulse and considerable thrust, are increasingly favored for large-scale space missions. This paper presents the composition, functiona...Applied field magnetoplasmadynamic thrusters(AF-MPDTs), with their high specific impulse and considerable thrust, are increasingly favored for large-scale space missions. This paper presents the composition, functionality, and testing methods of a high-power electric propulsion performance testing system, along with the vacuum ignition test results of a 100 kW superconducting MPD thruster. The relationships between thruster efficiency, magnetic field strength, current,and mass flow rate are analyzed. For each combination of current and flow rate in an AF-MPDT, there is an optimal magnetic field strength where the thruster efficiency reaches its peak. Under conditions of 320 A current and 60 mg/s flow rate,the optimal magnetic field strength is 0.5 T, yielding the highest thruster efficiency of 71%.展开更多
The magnetoplasmadynamic thruster(MPDT) is characterized by its high specific impulse and substantial thrust density, making it a promising propulsion system for deep space exploration missions. In both laboratory exp...The magnetoplasmadynamic thruster(MPDT) is characterized by its high specific impulse and substantial thrust density, making it a promising propulsion system for deep space exploration missions. In both laboratory experiments and practical applications, cathode ablation has emerged as a critical concern. An optical diagnostic approach based on monochromatic radiation temperature measurement, utilizing plume emission spectra and the selection of an appropriate test band, has been successfully employed. This method provides an accurate temperature distribution across the cathode surface, offering a novel testing technique for the optimization and evaluation of magnetic plasma thruster designs.展开更多
Background:Computed tomography images are easy to misjudge because of their complexity,especially images of solitary pulmonary nodules,of which diagnosis as benign or malignant is extremely important in lung cancer tr...Background:Computed tomography images are easy to misjudge because of their complexity,especially images of solitary pulmonary nodules,of which diagnosis as benign or malignant is extremely important in lung cancer treatment.Therefore,there is an urgent need for a more effective strategy in lung cancer diagnosis.In our study,we aimed to externally validate and revise the Mayo model,and a new model was established.Methods:A total of 1450 patients from three centers with solitary pulmonary nodules who underwent surgery were included in the study and were divided into training,internal validation,and external validation sets(n=849,365,and 236,respectively).External verification and recalibration of the Mayo model and establishment of new logistic regression model were performed on the training set.Overall performance of each model was evaluated using area under receiver operating characteristic curve(AUC).Finally,the model validation was completed on the validation data set.Results:The AUC of the Mayo model on the training set was 0.653(95%confidence interval[CI]:0.613–0.694).After re-estimation of the coefficients of all covariates included in the original Mayo model,the revised Mayo model achieved an AUC of 0.671(95%CI:0.635–0.706).We then developed a new model that achieved a higher AUC of 0.891(95%CI:0.865–0.917).It had an AUC of 0.888(95%CI:0.842–0.934)on the internal validation set,which was significantly higher than that of the revised Mayo model(AUC:0.577,95%CI:0.509–0.646)and the Mayo model(AUC:0.609,95%CI,0.544–0.675)(P<0.001).The AUC of the new model was 0.876(95%CI:0.831–0.920)on the external verification set,which was higher than the corresponding value of the Mayo model(AUC:0.705,95%CI:0.639–0.772)and revised Mayo model(AUC:0.706,95%CI:0.640–0.772)(P<0.001).Then the prediction model was presented as a nomogram,which is easier to generalize.Conclusions:After external verification and recalibration of the Mayo model,the results show that they are not suitable for the prediction of malignant pulmonary nodules in the Chinese population.Therefore,a new model was established by a backward stepwise process.The new model was constructed to rapidly discriminate benign from malignant pulmonary nodules,which could achieve accurate diagnosis of potential patients with lung cancer.展开更多
Fabrication of large-area and uniform semiconducting thin films of two-dimensional(2D)materials is paramount for the full exploitation of their atomic thicknesses and smooth surfaces in integrated circuits.In addition...Fabrication of large-area and uniform semiconducting thin films of two-dimensional(2D)materials is paramount for the full exploitation of their atomic thicknesses and smooth surfaces in integrated circuits.In addition to elaborate vapor-based synthesis techniques for the wafer-scale growth of 2D films,solution-based approaches for high-quality thin films from the liquid dispersions of 2D flakes,despite underdeveloped,are alternative cost-effective tactics.Here,we present layer-by-layer(LbL)assembly as an effective approach to obtaining scalable semiconducting films of molybdenum disulfide(MoS_(2))for field-effect transistors(FETs).LbL assembly is achieved by coordinating electrochemically exfoliated MoS_(2) with cationic poly(diallyldimethylammonium chloride)(PDDA)through electrostatic interactions.The PDDA/MoS_(2) percolating nanofilms show controlled and self-limited growth on a variety of substrates,and are easily patterned through lift-off processes.Ion gel gated FETs are fabricated on these MoS_(2) nanofilms,and they show mobilities of 9.8 cm^(2)·V^(−1)·s^(−1),on/off ratios of 2.1×10^(5) with operating voltages less than 2 V.The annealing temperature in the fabrication process can be as low as 200℃,thereby permitting the fabrication of flexible FETs on polyethylene terephthalate substrates.The LbL assembly technique holds great promise for the large-scale fabrication of flexible electronics based on solution-processed 2D semiconductors.展开更多
基金the National Natural Science Foundation of China(Nos.52222701,52077211,and 52307034).
文摘The superconducting magnet system of a fusion reactor plays a vital role in plasma confinement,a process that can be dis-rupted by various operational factors.A critical parameter for evaluating the temperature margin of superconducting magnets during normal operation is the nuclear heating caused by D-T neutrons.This study investigates the impact of nuclear heat-ing on a superconducting magnet system by employing an improved analysis method that combines neutronics and thermal hydraulics.In the magnet system,toroidal field(TF)magnets are positioned closest to the plasma and bear the highest nuclear-heat load,making them prime candidates for evaluating the influence of nuclear heating on stability.To enhance the modeling accuracy and facilitate design modifications,a parametric TF model that incorporates heterogeneity is established to expedite the optimization design process and enhance the accuracy of the computations.A comparative analysis with a homogeneous TF model reveals that the heterogeneous model improves accuracy by over 12%.Considering factors such as heat load,magnetic-field strength,and cooling conditions,the cooling circuit facing the most severe conditions is selected to calculate the temperature of the superconductor.This selection streamlines the workload associated with thermal-hydraulic analysis.This approach enables a more efficient and precise evaluation of the temperature margin of TF magnets.Moreover,it offers insights that can guide the optimization of both the structure and cooling strategy of superconducting magnet systems.
基金Supported by the Health and Family Planning Commission Project from Jiangsu Province,China(No.H201672)Xuzhou Medical Innovation(Technical Breakthrough)Team from Xuzhou Health and Planning Committee(No.XWCX201610)。
文摘AIM:To assess the effect of age at diabetes onset and uncontrollable high Hb A1 c levels on the development of diabetic retinopathy(DR)among Chinese type 2 diabetes mellitus(DM)patients.METHODS:This was a cross-sectional survey of diabetic patients in Subei district,China.Data covering physical measurements,fasting blood-glucose(FBG),glycosylated hemoglobin(Hb A1 c),blood lipid,urinary albumin/creatinine ratio(UACR),ocular fundus examination,and diabetes treatment records were collected.An independent sample t-test were used to analyze differences.A Logistic regression analysis was applied to study the independent risk factors of DR.RESULTS:A total of 1282 patients with type 2 DM were enrolled,and 191 cases had DR(14.9%).The age at diabetes onset,education level,alcohol consumption,Hb A1 c level,UACR level,and hypoglycemic drugs were independent influencing factors for DR.The older the onset of diabetes,the less likely to develop DR(OR:0.958,95%CI:0.942-0.975,P=0.000).Patients were then divided in terms of age at diabetes onset as follows:<50 y,50-59 y,60-69 y,and≥70 y.Compared with diabetes onset age<50 y,50-59 y(OR:0.463,95%CI:0.306-0.699,P=0.000),60-69 y(OR:0.329,95%CI:0.203-0.535,P=0.000)and≥70 y(OR:0.232,95%CI:0.094-0.577,P=0.002)were at a lower risk of DR.The prevalence of DR was highest in patients with diabetes onset age<50 y(29.5%,P<0.05).The Hb A1 c level(8.67±1.97)%and proportion of insulin injection(52.5%)in patients with diabetes onset<40 y were higher than in patients with older diabetes onset age(P<0.05).CONCLUSION:Diabetes onset at an earlier age and uncontrollable high Hb A1 c level could be independent risk factors for DR.
基金This work was supported by the National Natural Science Funding of China(Grants 31170333 and 31570363).
文摘Phytochemicalinvestigation onthe whole plants of Ypsilandra yunnanensiswas carried out forthe firsttime andledtothe isolation of five new cholestanol glycosides,ypsiyunnosides A–E(1–5),and one known analogue.Their structures were determined mainly by detailed spectroscopic analysis,including extensive 1D and 2D NMR,MS and UV,as well as chemical methods.Among them,compound 1 possessed a rare 6/6/6/5/5 fused-rings cholestanol sketelon,which was identified as(23R,25R)-3β,16α,26-triol-16,23-cyclocholest-5,17(20)-dien-22-one.Their induced platelet aggregation activities and cytotoxicities were evaluated.Graphical Abstract Five new cholestanol glycosides,ypsiyunnosides A–E(1–5),were isolated from the whole plants of Ypsilandra yunnanensis.Compound 1 possessed a rare 6/6/6/5/5 fused-rings cholestanol sketelon.Their structures were elucidated by a combination of 1D and 2D NMR,MS and chemical analysis.
基金supported by the National Natural Science Foundation of China(Nos.31570363,31770391,and 31600283)the Natural Science Foundation of Yunnan Province(2015FA031 and 2017FB128)+2 种基金the Science and Technology Research Program(Grant No.KIB2016001)of Kunming Institute of Botany,CAS,Guiding Program of Interdisciplinary Studies from Kunming Institute of Botany,CAS(Grant No.KIB2017004)the Foundation of State Key Laboratory of Phytochemistry and Plant Resources in West China(P2017-ZZ04)Kunming Institute of Botany,Chinese Academy of Sciences.
文摘Rhizoma Paridis(RP,M®),a traditional Chinese medicine,is the rhizoma of Paris polyphylla var.yunnanensis(PPY)or P.polyphylla var.chinensis which are widely used as important raw materials for several Chinese patent drugs.However,the wild resources of these herbs have become less and less due to their slow-growing characteristics and previously excessive excavation.This review covers untiring investigations on alternative resources of RP by our research group over the past decades,including non-medicinal parts of PPY as well as other plants of Liliaceae and Liliflorae families.The arial parts of PPY and the whole plants of Trillium kamtschaticum might be alternative resources for RP based on the fact that they shared the same or similar saponins and bioactivities.
基金supported by National Natural Science Funding of China(No.31170333)the Natural Sci-ence Foundation of Yunnan Province(No.2009CC019)+1 种基金the West Light Foundation of the Chinese Academy of Sciences(No.2908025712W1)a fund(No.540806321211)of State Key Laboratory of Phytochemistry and Plant Resources in West China,Germplasm Bank of Wild Species and CAS Innovation Program of Kunming Institute of Botany.
文摘The whole plants of Ypsilandra thibetica have been analyzed as part of a systematic study on saponin constituents of medicinal plants.This has resulted in the isolation of two new bisdesmosidic furostanol saponins,named ypsilandroside P(1)and ypsilandroside Q(2),and one new pregnane glycoside,named ypsilandroside R(3),together with nine known steroidal glycosides.Their structures were elucidated on the basis of extensive spectroscopic analysis,including that of 2D NMR data,and the results of acidic hydrolysis.Ypsilandroside P(1)was cytotoxicity against two human tumor cell lines.
基金This work is funded by the National Natural Science Funding of China(Grand No.31570363)the Key Research Program of the Chinese Academy of Sciences(Grand No.KSZDEW-Z-004-03-4)the Natural Science Foundation of Yunnan Province(Grand No.2015FA031).
文摘Phytochemical investigation of the rhizomes of Paris polyphylla var.stenophylla led to the isolation of two new highly oxygenated spirostanol saponins,named paristenosides A(1)and B(2),together with seven known compounds.Their structures were established mainly on the base of NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.In addition,the cytotoxicity of the two new saponins was tested.Graphical Abstract Two new highly oxygenated spirostanol saponins,paristenosides A(1)and B(2),were isolated from the rhizomes of Paris polyphylla var.stenophylla.Their structures were established mainly based on NMR spectroscopic techniques and mass spectrometry,as well as chemical methods.
基金the National Natural Science Funding of China(No.31170333)the Natural Science Foundation of Yunnan Province(No.2009CC019).
文摘Two new monosaccharide steroidal saponins,named ypsilandroside S(1)and ypsilandroside T(2),have been isolated from the whole plants of Ypsilandra thibetica.Their structures were elucidated as heloniogenin 3-O-b-D-apiofuranoside(1)and pregna 5,16-dien-3b,12a-diol-20-one-3-O-b-D-apiofuranoside(2)by spectroscopic techniques(1D and 2D NMR,MS).Compounds 1 and 2 were tested for their inhibitory effects on lipopolysaccharide-induced nitric oxide production in RAW 264.7 cells.
文摘BACKGROUNDPerioperative stroke is a rare but devastating complication. The risk factors formassive cerebral stroke in surgical patients include older age, male sex, priorcerebrovascular disease, hypertension, renal failure, smoking, diabetes mellitus,and atrial fibrillation.CASE SUMMARYWe describe two cases of perioperative massive cerebral stroke following thoracicsurgery and one case following bronchoscopy. Neurologic symptoms, includingchanges in mental status and hemiplegia, occurred within 10 h after surgery in thethree patients. All three patients died after the surgery.CONCLUSIONPerioperative massive cerebral stroke may be more likely to occur in thoracicsurgical patients if there are pre-existing factors including previous stroke,hypotension, and hypoxemia. Sufficient pain control after surgery and timelyneurology consultation and management are helpful for the diagnosis and controlof stroke in high-risk patients.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.31570363 and 31770391)Key Research and Development Plan of Yunnan Province–Special Project of Science and Technology in Yunnan Province(2017IB007)+2 种基金Major Biomedical Project of Yunnan Province(2018ZF005)Innovation Team of the Ministry of Education(No.IRT-17R49)the Foundation of State Key Laboratory of Phytochemistry and Plant Resources in West China(P2017-ZZ04 and P2017-KF06),Kunming Institute of Botany,Chinese Academy of Sciences.
文摘Phytochemical investigation of the MeOH extract of twigs and leaves of Baeckea frutescens led to the isolation of seven new polymethylated phloroglucinol meroterpenoids(PPMs),named baeckfrutones M-S(1-7).Their structures and absolute configurations were determined by spectroscopic analyses,chiral-phase HPLC analysis,and electronic circular dichroism(ECD)calculations.PPM 1 is a novel meroterpenoid possessing a 6/6/5/3 tetracyclic skeleton in PPMs,whereas 3 and 4 are the first hydroxytasmanone type phloroglucinol-monoterpene hybrids.(+)-2 and 7 displayed potent antiinflammatory activity with IC50 values of 20.86±0.60 and 36.21±1.18 lL,respectively.
基金supported by National Natural Science Funding of China(No.81072543)the Key Project of Knowledge Innovation Project of CAS(No.KSCX2-EW-Q-10)funds(No.P2009-KF04)from the State Key Laboratory of Phytochemistry and Plant Resources in West China.
文摘Two new eudesmane-type sesquiterpenoid lactones,named chlorelactone A(1)and chlorelactone B(2),and one new labdane-type diterpenoid,named elatiorlabdane(3),along with seven known sesquiterpenoids and one known disesquiterpenoid were isolated from the whole plants of Chloranthus elatior.Their structures and relative configurations were established on the basis of extensive spectroscopic analysis.
基金supported by the National Natural Science Foundation of China (U1802287 and 32000280)the Ten Thousand Talents Plan of Yunnan Province for Industrial Technology Leading Talentsthe State Key Laboratory of Phytochemistry and Plant Resources in West China (P2019-ZZ02).
文摘Phytochemical reinvestigation on the whole plants of Ypsilandra thibetica obtained four new spirostanol glycosides,named ypsilandrosides U-X(1-4),and one new cholestanol glycoside,named ypsilandroside Y(5).Their structures have been established by extensive spectroscopic data and chemical methods.Among them,compound 4 is a rare spirostanol glycoside which possesses a novel 5(6→7)abeo-steroidal aglycone,while compound 1 is a first spiro-stanol bisdesmoside attached to C-3 and C-12,respectively,isolated from the genus Ypsilandra.The induced platelet aggregation activity of the isolates was tested.
基金National Natural Science Foundation of China(Nos.31600283 and 31570363)fund of State Key Laboratory of Phytochemistry and Plant Resources in West China(No.P2017-ZZ04)from Kunming Institute of Botany,Chinese Academy of Sciences.
文摘Callisalignenes G–I(1–3),three new meroterpenoids of b-triketone and monoterpene,along with two known analogues(4 and 5),were isolated from Callistemon salignus.Their structures and absolute configurations were unambiguously established by a combination of NMR and MS analysis and electronic circular dichroism(ECD)evidence.Callisalignenes H(2)and I(3)have a rare sec-butyl moiety at C-7.Meroterpenoids 1–3 exhibited cytotoxicity against HCT116 cells with IC50 values of 8.51±1.8,9.12±0.3,and 16.33±3.3 lM,respectively.
文摘Correction to:Natural Products and Bioprospecting(2018)8:431–439 https://doi.org/10.1007/s13659-018-0189-3 In the original publication,two errors have occurred.The corrected texts are provided below:1.The author,Xu-Jie Qi,should read as Xu-Jie Qin among the author group.2.The reference 9 should be cited as X.J.Qin,Y.E.Zhi,H.Yan,Y.Zhang,H.Liu,Q.Yu,S.Wang,Q.Zhao,L.He,X.Ma,L.K.An,H.Y.Liu,Tetrahedron 74,6658–6666(2018).
基金Funding for the project has been provided by the National Development and Reform Commissionsupported by the Strategic Priority Research Program “The Emergence of Cosmological Structures” of the Chinese Academy of Sciences (No. XDB09000000)+1 种基金the National Basic Research Program of China (973 Program) (2015CB857004)the National Natural Science Foundation of China (NSFC, Nos. 11225315, 1320101002, 11433005 and 11421303)
文摘We present a sample of 48 metal-poor galaxies at z 〈 0.14 selected from 92 510 galaxies in the LAMOST survey. These galaxies are identified by their detection of the auroral emission line[OⅢ]λ4363 above the 3σ level, which allows a direct measurement of electron temperature and oxygen abundance. The emission line fluxes are corrected for internal dust extinction using the Balmer decrement method. With electron temperature derived from [OⅢ]λλ4959, 5007/[OⅢ]λ4363 and electron density from [SⅡ]λ6731/[SⅡ]λ6717, we obtain the oxygen abundances in our sample which range from 12 ＋ log（O/H） = 7.63（0.09 Z_⊙） to 8.46（0.6 Z_⊙）. We find an extremely metal-poor galaxy with 12 ＋ log（O/H） = 7.63 ± 0.01. With multiband photometric data from FUV to NIR and Hαmeasurements, we also determine the stellar masses and star formation rates, based on the spectral energy distribution fitting and Hα luminosity, respectively. We find that our galaxies have low and intermediate stellar masses with 6.39 ≤ log（M/M_⊙） ≤ 9.27, and high star formation rates（SFRs） with-2.18 ≤ log（SFR/M_⊙yr^（-1）） ≤ 1.95. We also find that the metallicities of our galaxies are consistent with the local T_e-based mass-metallicity relation, while the scatter is about 0.28 dex. Additionally,assuming the coefficient of α = 0.66, we find most of our galaxies follow the local mass-metallicity-SFR relation, but a scatter of about 0.24 dex exists, suggesting the mass-metallicity relation is weakly dependent on SFR for those metal-poor galaxies.
文摘Applied field magnetoplasmadynamic thrusters(AF-MPDTs), with their high specific impulse and considerable thrust, are increasingly favored for large-scale space missions. This paper presents the composition, functionality, and testing methods of a high-power electric propulsion performance testing system, along with the vacuum ignition test results of a 100 kW superconducting MPD thruster. The relationships between thruster efficiency, magnetic field strength, current,and mass flow rate are analyzed. For each combination of current and flow rate in an AF-MPDT, there is an optimal magnetic field strength where the thruster efficiency reaches its peak. Under conditions of 320 A current and 60 mg/s flow rate,the optimal magnetic field strength is 0.5 T, yielding the highest thruster efficiency of 71%.
文摘The magnetoplasmadynamic thruster(MPDT) is characterized by its high specific impulse and substantial thrust density, making it a promising propulsion system for deep space exploration missions. In both laboratory experiments and practical applications, cathode ablation has emerged as a critical concern. An optical diagnostic approach based on monochromatic radiation temperature measurement, utilizing plume emission spectra and the selection of an appropriate test band, has been successfully employed. This method provides an accurate temperature distribution across the cathode surface, offering a novel testing technique for the optimization and evaluation of magnetic plasma thruster designs.
基金the National Natural Science Foundation of China(No.81670091)the Zhongyuan Science and Technology Innovation Leading Talent Project(No.194200510).
文摘Background:Computed tomography images are easy to misjudge because of their complexity,especially images of solitary pulmonary nodules,of which diagnosis as benign or malignant is extremely important in lung cancer treatment.Therefore,there is an urgent need for a more effective strategy in lung cancer diagnosis.In our study,we aimed to externally validate and revise the Mayo model,and a new model was established.Methods:A total of 1450 patients from three centers with solitary pulmonary nodules who underwent surgery were included in the study and were divided into training,internal validation,and external validation sets(n=849,365,and 236,respectively).External verification and recalibration of the Mayo model and establishment of new logistic regression model were performed on the training set.Overall performance of each model was evaluated using area under receiver operating characteristic curve(AUC).Finally,the model validation was completed on the validation data set.Results:The AUC of the Mayo model on the training set was 0.653(95%confidence interval[CI]:0.613–0.694).After re-estimation of the coefficients of all covariates included in the original Mayo model,the revised Mayo model achieved an AUC of 0.671(95%CI:0.635–0.706).We then developed a new model that achieved a higher AUC of 0.891(95%CI:0.865–0.917).It had an AUC of 0.888(95%CI:0.842–0.934)on the internal validation set,which was significantly higher than that of the revised Mayo model(AUC:0.577,95%CI:0.509–0.646)and the Mayo model(AUC:0.609,95%CI,0.544–0.675)(P<0.001).The AUC of the new model was 0.876(95%CI:0.831–0.920)on the external verification set,which was higher than the corresponding value of the Mayo model(AUC:0.705,95%CI:0.639–0.772)and revised Mayo model(AUC:0.706,95%CI:0.640–0.772)(P<0.001).Then the prediction model was presented as a nomogram,which is easier to generalize.Conclusions:After external verification and recalibration of the Mayo model,the results show that they are not suitable for the prediction of malignant pulmonary nodules in the Chinese population.Therefore,a new model was established by a backward stepwise process.The new model was constructed to rapidly discriminate benign from malignant pulmonary nodules,which could achieve accurate diagnosis of potential patients with lung cancer.
基金The work was supported by the National Natural Science Foundation of China(No.51873088)Tianjin Municipal Science and Technology Commission(No.18JCZDJC38400)111 Project(B18030)in China.
文摘Fabrication of large-area and uniform semiconducting thin films of two-dimensional(2D)materials is paramount for the full exploitation of their atomic thicknesses and smooth surfaces in integrated circuits.In addition to elaborate vapor-based synthesis techniques for the wafer-scale growth of 2D films,solution-based approaches for high-quality thin films from the liquid dispersions of 2D flakes,despite underdeveloped,are alternative cost-effective tactics.Here,we present layer-by-layer(LbL)assembly as an effective approach to obtaining scalable semiconducting films of molybdenum disulfide(MoS_(2))for field-effect transistors(FETs).LbL assembly is achieved by coordinating electrochemically exfoliated MoS_(2) with cationic poly(diallyldimethylammonium chloride)(PDDA)through electrostatic interactions.The PDDA/MoS_(2) percolating nanofilms show controlled and self-limited growth on a variety of substrates,and are easily patterned through lift-off processes.Ion gel gated FETs are fabricated on these MoS_(2) nanofilms,and they show mobilities of 9.8 cm^(2)·V^(−1)·s^(−1),on/off ratios of 2.1×10^(5) with operating voltages less than 2 V.The annealing temperature in the fabrication process can be as low as 200℃,thereby permitting the fabrication of flexible FETs on polyethylene terephthalate substrates.The LbL assembly technique holds great promise for the large-scale fabrication of flexible electronics based on solution-processed 2D semiconductors.
