Multiple sclerosis is an inflammatory disorder chara cterized by inflammation,demyelination,and neurodegeneration in the central nervous system.Although current first-line therapies can help manage symptoms and slow d...Multiple sclerosis is an inflammatory disorder chara cterized by inflammation,demyelination,and neurodegeneration in the central nervous system.Although current first-line therapies can help manage symptoms and slow down disease progression,there is no cure for multiple sclerosis.The gut-brain axis refers to complex communications between the gut flo ra and the immune,nervous,and endocrine systems,which bridges the functions of the gut and the brain.Disruptions in the gut flora,termed dys biosis,can lead to systemic inflammation,leaky gut syndrome,and increased susceptibility to infections.The pathogenesis of multiple sclerosis involves a combination of genetic and environmental factors,and gut flora may play a pivotal role in regulating immune responses related to multiple scle rosis.To develop more effective therapies for multiple scle rosis,we should further uncover the disease processes involved in multiple sclerosis and gain a better understanding of the gut-brain axis.This review provides an overview of the role of the gut flora in multiple scle rosis.展开更多
Background:The Taylor Spatial Frame(TSF)has gained popularity among orthopedic surgeons for treating open fractures.However,a key challenge is the timely and safe removal of the frame.This study assessed the efficacy ...Background:The Taylor Spatial Frame(TSF)has gained popularity among orthopedic surgeons for treating open fractures.However,a key challenge is the timely and safe removal of the frame.This study assessed the efficacy and safety of axial load-share ratio(ALSR)testing to evaluate callus healing strength after TSF treatment of open tibial fractures.Methods:A retrospective case-control study was conducted,analyzing 180 adult patients with open tibial fractures treated at Tianjin Hospital’s Orthopedic Limb Correction Unit between August 2019 and August 2022.All patients underwent TSF external fixation surgery,and were divided into two groups based on ALSR testing.Group I(92 patients)underwent ALSR testing,with frame removal if the test value fell below 5%.Traditional methods were used for fixator removal guidance in Group II(88 patients).Clinical outcomes,including fixation duration,complications after fixator removal,and Johner-Wruhs functional scores,were compared between the two groups.Results:The groups showed no statistically significant differences(P>0.05)in sex,age,injury side,body mass index,surgery timing,or fracture type.Group I had a significantly shorter fixation duration(25.85±5.57 weeks)compared to Group II(31.82±6.98 weeks)(P<0.05).Following fixator removal,Group I demonstrated superior Johner-Wruhs scores compared to Group II,indicating better outcomes(P<0.05).Complication rates did not differ significantly between the groups at the last follow-up(P>0.05).Conclusion:Regular postoperative ALSR testing could safely and effectively guide TSF removal following open tibial fracture treatment.This method significantly reduced fixation duration compared to traditional guidance methods while maintaining efficacy and safety.展开更多
Because of the increasingly prominent problem of alumina content inhomogeneity in large or super-scale aluminum reduction cells,a transient numerical model for the alumina mixing process was developed for a400kA cell,...Because of the increasingly prominent problem of alumina content inhomogeneity in large or super-scale aluminum reduction cells,a transient numerical model for the alumina mixing process was developed for a400kA cell,and the relationship between the alumina content distribution and electrolyte flow field was analyzed.In the ANSYS software platform,several numerical simulation cases were presented to display the influence of the feeder configuration on the alumina mixing characteristics.The results showed that a large vortex flow of the molten electrolyte is beneficial for alumina mixing and uniform distribution in the inner areas of the vortexes.The alumina particles reach the inter-electrode zone in10?15s from the beginning of the feeding action,and the risk of early precipitation occurs in10?25s after the feeding.It was also found that a suitable grouping of feeders could reduce the content fluctuation and gradient.Therefore,a feeding on demand strategy was proposed,and the simulation results showed that although the spatial characteristics are not changed,the uniformity of the alumina content was markedly improved.展开更多
In view of the unclear cause of perfluorocarbons(PFCs)emission in the anode effect stage of aluminum electrolysis,the microscopic formation mechanism of PFCs was studied by density functional theory calculation and X-...In view of the unclear cause of perfluorocarbons(PFCs)emission in the anode effect stage of aluminum electrolysis,the microscopic formation mechanism of PFCs was studied by density functional theory calculation and X-ray photoelectron spectroscopy(XPS).It is found that the discharge of fluorine containing anions([F]−)on carbon anode first causes the substitution of C—H by C—F and further results in the saturation of aromatic C—C bonds,leading to the appearance of—CF_(3)or—C_(2)F_(5)group through six-carbon-ring opening.Elimination of—CF_(3)and—C_(2)F_(5) with F atom could be a likely mechanism of CF_(4) and C_(2)F_(6) formation.XPS results confirm that different types of—CF_(x) group can be formed on anode surface during electrolysis,and the possibility that[F]−discharges continuously at the C edge and finally forms different C—F bonds in quantum mechanical calculation was verified.展开更多
Multiple sclerosis （MS） is a chronic inflammatory demyelinating disorder of the central nervous system characterized by episodic and progressive neurologic dysfunction resulting from inflammatory and autoimmune reac...Multiple sclerosis （MS） is a chronic inflammatory demyelinating disorder of the central nervous system characterized by episodic and progressive neurologic dysfunction resulting from inflammatory and autoimmune reactions. The underlying pathogenesis of MS remains largely unclear. However, it is currently accepted as a T cell-mediated autoimmune disease. Among other clinical manifestations, sexual dysfunction （SD） is a painful but still underreported and underdiagnosed symptom of the disorder. SD in MS patients may result from a complex set of conditions and may be associated with multiple anatomic, physiologic, biologic, medical and psychological factors. SD arises primarily from lesions affecting the neural pathways involved in physiologic function. In addition, psychological factors, the side effects of medications and physical symptoms such as fatigue, muscular weakness, menstrual changes, pain and concerns about bladder and bowel incontinence may also be involved. Since MS primarily affects young people, SD secondary to MS may have a great impact on quality of life. Thus, maintaining a healthy sexual life with MS is an important priority. The treatment of SD requires multidisciDlinarv teamwork and coooeration amone specialists,individual patients, partners and the society.展开更多
A comprehensive dataset from 594 fracturing wells throughout the Duvernay Formation near Fox Creek, Alberta, is collected to quantify the influences of geological, geomechanical, and operational features on the distri...A comprehensive dataset from 594 fracturing wells throughout the Duvernay Formation near Fox Creek, Alberta, is collected to quantify the influences of geological, geomechanical, and operational features on the distribution and magnitude of hydraulic fracturing-induced seismicity. An integrated machine learning-based investigation is conducted to systematically evaluate multiple factors that contribute to induced seismicity. Feature importance indicates that a distance to fault, a distance to basement, minimum principal stress, cumulative fluid injection, initial formation pressure, and the number of fracturing stages are among significant model predictors. Our seismicity prediction map matches the observed spatial seismicity, and the prediction model successfully guides the fracturing job size of a new well to reduce seismicity risks. This study can apply to mitigating potential seismicity risks in other seismicity-frequent regions.展开更多
Recent advances in neuroimaging contribute a lot to the accurate diagnosis and evaluation of cerebrovascular diseases. To explore the relationship among blood perfusion, metabolism and brain structure integrity, 6 Chi...Recent advances in neuroimaging contribute a lot to the accurate diagnosis and evaluation of cerebrovascular diseases. To explore the relationship among blood perfusion, metabolism and brain structure integrity, 6 Chinese transient ischemic attack (TIA) patients with middle cerebral artery (MCA) stenosis were examined by xenon-enhanced computed tomography (Xe-CT), magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) to compare cerebral blood flow (CBF) values, (choline + creatine)/ N-acetyl aspartate [(Cho + Cr)/NAA] values and fractional anisotropy (FA) values in the MCA territory. Our results showed that CBF values significantly decreased in the ipsilateral basal ganglion regions in all 5 cases with unilateral MCA stenosis, with a corresponding decrease of FA values in the same region. In conclusion, decreased blood perfusion may indicate nerve fibre damage in the dominating regions of stenosed arteries.展开更多
A previously healthy 19 year-old college student presented with abrupt onset of nausea, vomiting, dizziness and vertigo, and progressively worsened with hoarseness, and swallowing disturbance, imbalance, numbness of r...A previously healthy 19 year-old college student presented with abrupt onset of nausea, vomiting, dizziness and vertigo, and progressively worsened with hoarseness, and swallowing disturbance, imbalance, numbness of right face and left-side limbs and trunk. The diagnosis of Wallenberg syndrome was established by clinical manifestations and medullary hemorrhage by combination use of magnetic resonance imaging (MRI) with computed tomography (CT). Supportive treatment was given to the patient and there was considerable improvement in his neurologic status after 40 days treatment.展开更多
Tungsten(W),as a plasma-facing material,is subjected to high fluence plasma,resulting in both radiation damage and deuterium(D)retention.This study explores the blistering behavior and D supersaturated layers in both ...Tungsten(W),as a plasma-facing material,is subjected to high fluence plasma,resulting in both radiation damage and deuterium(D)retention.This study explores the blistering behavior and D supersaturated layers in both pre-damaged and undamaged W samples.To achieve a uniform damage profile similar to neutron irradiation,carbon(C)ions with multiple energies and angles were employed.The samples were further irradiated with low-energy D ions under two fluences at temperatures from~380 to 640 K.Using various experimental techniques,we found that pre-damaged W samples can effectively suppress the formation of blistering and lower the threshold temperature at which the surface remains free of blistering.We also observed the prominent D supersaturated peaks within the depth of 20 nm in both pre-damaged and undamaged W.Furthermore,a close correlation between blistering and the D supersaturation was investigated.The results suggest that neutron irradiation in the fusion reactors could increase the critical D concentration for blistering,while a greater depth of damage facilitated the inward diffusion of D,thereby reducing the D concentration gradient and alleviating surface blistering.展开更多
Life sciences,a group of disciplines dedicated to exploring biological phenomena and elucidating the principles underlying biological activities,span multiple levels of research ranging from molecules to cells,tissues...Life sciences,a group of disciplines dedicated to exploring biological phenomena and elucidating the principles underlying biological activities,span multiple levels of research ranging from molecules to cells,tissues,organs,individuals,and populations.It represents one of the most dynamic frontiers in contemporary scientific research[1].In recent years,China has made remarkable progress in scientific research investment and development.China’s basic research funds reached 221.2 billion yuan in 2023,representing a 9.3%increase over the previous year.展开更多
In this study, the genetic diversity of 51 cultivars in the primary core collection of peach （Prunus persica （L.） Batsch） was evaluated by using simple sequence repeats （SSRs）. The phylogenetic relationships and...In this study, the genetic diversity of 51 cultivars in the primary core collection of peach （Prunus persica （L.） Batsch） was evaluated by using simple sequence repeats （SSRs）. The phylogenetic relationships and the evolutionary history among different cultivars were determined on the basis of SSR data. Twenty-two polymorphic SSR primer pairs were selected, and a total of 111 alleles were identified in the 51 cultivars, with an average of 5 alleles per locus. According to traditional Chinese classification of peach cultivars, the 51 cultivars in the peach primary core collection belong to six variety groups. The SSR analysis revealed that the levels of the genetic diversity within each variety group were ranked as Sweet peach 〉 Crisp peach 〉 Flat peach 〉 Nectarine 〉 Honey Peach 〉 Yellow fleshed peach. The genetic diversity among the Chinese cultivars was higher than that among the introduced cultivars. Cluster analysis by the unweighted pair group method with arithmetic averaging （UPGMA） placed the 51 cultivars into five linkage clusters. Cultivar members from the same variety group were distributed in different UPGMA clusters and some members from different variety groups were placed under the same cluster. Different variety groups could not be differentiated in accordance with SSR markers. The SSR analysis revealed rich genetic diversity in the peach primary core collection, representative of genetic resources of peach.展开更多
Objective Cerebral autoregulation （CA） is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure. CA can be evaluated by dynamic monitoring of cerebral blood...Objective Cerebral autoregulation （CA） is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure. CA can be evaluated by dynamic monitoring of cerebral blood flow velocity （CBFV） with transcranial Doppler sonography （TCD）. The present study aimed to explore CA in chronic anxiety. Methods Subjects with Hamilton anxiety scale scores 〉14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD. Results In both the anxious and the healthy subjects, the mean CBFV was significantly lower in the upright position than when supine. However, the CBFV changes from supine to upright differed between the anxious and the healthy groups. Anxious subjects showed more pronounced decreases in CBFV with abrupt standing. Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety; anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change. Given the fact that anxiety and impaired CA are associated with cardiovascular disease, early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population, and improve the primary prevention of cardiovascular disease.展开更多
The aim of our study was to compare the sperm retrieval rates(SRRs)and clinical outcomes of patients with different causes of azoospermia who underwent microdissection testicular sperm extraction-intracytoplasmic sper...The aim of our study was to compare the sperm retrieval rates(SRRs)and clinical outcomes of patients with different causes of azoospermia who underwent microdissection testicular sperm extraction-intracytoplasmic sperm injection(micro-TESE-ICSI).We conducted a retrospective study at the Reproductive Medicine Center of Peking University Third Hospital in Beijing,China,from January 2014 to December 2017.This study examined 769 patients with nonobstructive azoospermia who underwent 347 cycles of micro-TESE-ICSI.Patients with azoospermia were classified into Group A(Klinefelter syndrome,n=284,125 cycles),Group B(azoospermia Y chromosome factor c[AZFc]microdeletion,n=91,64 cycles),Group C(cryptorchidism,n=52,39 cycles),Group D(previous mumps and bilateral orchitis,n=23,23 cycles),and Group E(idiopathic azoospermia,n=319,96 cycles).Clinical characteristics,SRR,embryonic development,and pregnancy outcomes of the patients were compared between all groups.Patients in Group D had the highest and most successful SRR.The average SRR for all patients was 46.0%.The rates of clinical pregnancy,implantation,and live birth in Group D were 78.3%,65.0%,and 74.0%,respectively,which were higher than those in all other groups(P<0.05).Group B patients had the lowest clinical pregnancy,implantation,and live birth rates of all groups(P<0.05).No differences were found in the miscarriage rate or birth defects among the groups(P>0.05).Patients with orchitis had the highest SRR and best clinical outcomes.Although AZFc microdeletion patients had a higher SRR,their clinical outcomes were worse.展开更多
Previous studies suggest that air pollution has a negative effect on semen quality.However,most studies are cross-sectional and the results are controversial.This study investigated the associations between air pollut...Previous studies suggest that air pollution has a negative effect on semen quality.However,most studies are cross-sectional and the results are controversial.This study investigated the associations between air pollutants(PM25,PM10,SO2,NO2,CO,and O3)and seme n quality among sperm donation candidates,especially when the air pollution was artificially con trolled in Beijing,China.We an a lyzed 8945 semen samples in the human sperm bank of Peki ng Un iversity Third Hospital(Beijing,China)from October 2015 to May 2018.Air pollution data during the entire period(0-90 days prior)and key stages(0-9,10-14,and 70-90 days prior)of sperm development were collected from the China National Environmental Monitoring Centre.The association between air pollutants and seme n parameters(sperm con centrati on and progressive motility)was an a lyzed by a mixed model adjusted for age,abstinence duration,month,and average ambient temperature.Only O3 during key stages of 0-9 days and 10-14 days and the entire period was negatively associated with sperm concentration between 2015 and 2018(P v 0.01).During the period of air pollution control from November 2017 to January 2018,except for the in crease in O3 concentration,other five pollutants'concentrations decreased compared to those in previous years.In this period,the sperm concentration decreased(P<0.001).During the pollution-control period,O3 exposure 10-14 days prior was negatively associated with sperm concentration(95%Cl:-0.399—0.111;P<0.001).No significant association was found between the other five pollutants and semen quality during that period?Our study suggested that only O3 exposure was harmful to semen quality.Therefore,O3 should not be neglected during pollution control operation.展开更多
We performed this study to evaluate the clinical outcomes of microdissection testicular sperm extraction-intracytoplasmic sperm injection(micro-TESE-ICSI)treatment that used fresh or cryopreserved sperm in patients wi...We performed this study to evaluate the clinical outcomes of microdissection testicular sperm extraction-intracytoplasmic sperm injection(micro-TESE-ICSI)treatment that used fresh or cryopreserved sperm in patients with nonobstructive azoospermia(NOA).A total of 338 NOA patients with 344 consecutive cycles received treatment in the reproductive medicine center of Peking University Third Hospital in Beijing,China,from January 2014 to December 2017.Fresh oocytes and fresh sperm were used in 222 patients with 234 cycles(Group A).Fresh oocytes and cryopreserved sperm were used in 116 patients with 110 cycles(Group B).We compared patient characteristics,embryonic development,and pregnancy outcomes between Groups A and B.There was no statistical difference in the patient characteristics,and no differences were observed with fertilization or quality embryo rates between Groups A and B.The rates of clinical pregnancy and live birth were both higher for Group A than those for Group B(both P<0.05).In conclusion,fresh testicular sperm appears to produce better ICSI outcomes than cryopreserved testicular sperm in patients with NOA.展开更多
The emission of dioxins from the iron ore sintering process is the largest emission source of dioxins, and the reduction in dioxin emission from the iron ore sintering process to the environment is increasingly import...The emission of dioxins from the iron ore sintering process is the largest emission source of dioxins, and the reduction in dioxin emission from the iron ore sintering process to the environment is increasingly important. Three approaches to control the emission of dioxins were reviewed： source control, process control, and terminal control. Among them, two terminal control technologies, activated carbon adsorption and selective reduction technology, were discussed in detail. Following a comparison of the reduction technologies, the terminal control method was indicated as the key technology to achieve good control of dioxins during the sintering process. For the technical characteristics of the sintering process and flue gas, multiple methods should be collectively considered, and the most suitable method may be addition of inhibitors ＋ ultra-clean dust collection （electrostatic precipitation/bag filter） ＋ desulphurization ＋ selective catalytic reduction to sufficiently remove multiple pollutants, which provides a direction for the cooperative disposal of flue gas pollutants in future.展开更多
Objective: To present our treatment experiences and the follow-up data of patients with paradoxical embolism (PDE). Methods: The clinical characteristics, management, and follow-up data of all included patients who we...Objective: To present our treatment experiences and the follow-up data of patients with paradoxical embolism (PDE). Methods: The clinical characteristics, management, and follow-up data of all included patients who were diagnosed with PDE at Fuwai Hospital from January 1994 to October 2015 were recorded. Results: Twelve patients were included;all had a pulmonary embolism, and 8 had deep venous thrombosis. The artery embolisms involved the cerebral artery (7 patients), renal artery (2 patients), mesentery artery (2 patients), popliteal artery (1 patient), descending aorta thrombus (1 patient), and thrombus-straddled patent foramen ovale (PFO) (1 patient). PFO was found in 3 cases. One patient underwent thrombectomy and PFO closure;Six patients received thrombolysis;and 3 patients were implanted with a vena cava filter. Long-term anticoagulation with warfarin was recommended for each patient. One patient died from ventricular fibrillation despite cardiopulmonary resuscitation. Eleven patients were discharged with improvements. No late mortality occurred in 8 patients with a complete follow-up of 10.6-17.7 years. One had a recurrent deep venous thrombosis. No patient had a recurrent pulmonary or arterial embolism. Two patients changed their treatment from warfarin to aspirin;others remained on warfarin. Only 1 case had an occasional gum bleeding. Conclusions: PDE treatment including thrombolysis, anticoagulation, and embolectomy should be individualized. We recom-mend long-term anticoagulation therapy to prevent the recurrence of PDE, especially to those with an intracardiac communication or persistent risk factors for re-thrombosis.展开更多
文摘Multiple sclerosis is an inflammatory disorder chara cterized by inflammation,demyelination,and neurodegeneration in the central nervous system.Although current first-line therapies can help manage symptoms and slow down disease progression,there is no cure for multiple sclerosis.The gut-brain axis refers to complex communications between the gut flo ra and the immune,nervous,and endocrine systems,which bridges the functions of the gut and the brain.Disruptions in the gut flora,termed dys biosis,can lead to systemic inflammation,leaky gut syndrome,and increased susceptibility to infections.The pathogenesis of multiple sclerosis involves a combination of genetic and environmental factors,and gut flora may play a pivotal role in regulating immune responses related to multiple scle rosis.To develop more effective therapies for multiple scle rosis,we should further uncover the disease processes involved in multiple sclerosis and gain a better understanding of the gut-brain axis.This review provides an overview of the role of the gut flora in multiple scle rosis.
基金funding support from Natural Science Foundation Key Project of Tianjin(20JCZDJC00600)Tianjin Health Research Project(TJWJ2023QN050)+2 种基金Applied Basic Research Foundation of Tianjin(22JCQNJC00230,22JCQNJC00360)Beijing-Tianjin-Hebei Basic Research Cooperation Project(J230007/23JCZXJC00050)Tianjin Municipal Health Commission Key Discipline Specialization(TJWJ2024XK015).
文摘Background:The Taylor Spatial Frame(TSF)has gained popularity among orthopedic surgeons for treating open fractures.However,a key challenge is the timely and safe removal of the frame.This study assessed the efficacy and safety of axial load-share ratio(ALSR)testing to evaluate callus healing strength after TSF treatment of open tibial fractures.Methods:A retrospective case-control study was conducted,analyzing 180 adult patients with open tibial fractures treated at Tianjin Hospital’s Orthopedic Limb Correction Unit between August 2019 and August 2022.All patients underwent TSF external fixation surgery,and were divided into two groups based on ALSR testing.Group I(92 patients)underwent ALSR testing,with frame removal if the test value fell below 5%.Traditional methods were used for fixator removal guidance in Group II(88 patients).Clinical outcomes,including fixation duration,complications after fixator removal,and Johner-Wruhs functional scores,were compared between the two groups.Results:The groups showed no statistically significant differences(P>0.05)in sex,age,injury side,body mass index,surgery timing,or fracture type.Group I had a significantly shorter fixation duration(25.85±5.57 weeks)compared to Group II(31.82±6.98 weeks)(P<0.05).Following fixator removal,Group I demonstrated superior Johner-Wruhs scores compared to Group II,indicating better outcomes(P<0.05).Complication rates did not differ significantly between the groups at the last follow-up(P>0.05).Conclusion:Regular postoperative ALSR testing could safely and effectively guide TSF removal following open tibial fracture treatment.This method significantly reduced fixation duration compared to traditional guidance methods while maintaining efficacy and safety.
基金Projects(51574289,61533020,51674300)supported by the National Natural Science Foundation of ChinaProject(2015CXS017)supported by Innovation-driven Plan in Central South University,China
文摘Because of the increasingly prominent problem of alumina content inhomogeneity in large or super-scale aluminum reduction cells,a transient numerical model for the alumina mixing process was developed for a400kA cell,and the relationship between the alumina content distribution and electrolyte flow field was analyzed.In the ANSYS software platform,several numerical simulation cases were presented to display the influence of the feeder configuration on the alumina mixing characteristics.The results showed that a large vortex flow of the molten electrolyte is beneficial for alumina mixing and uniform distribution in the inner areas of the vortexes.The alumina particles reach the inter-electrode zone in10?15s from the beginning of the feeding action,and the risk of early precipitation occurs in10?25s after the feeding.It was also found that a suitable grouping of feeders could reduce the content fluctuation and gradient.Therefore,a feeding on demand strategy was proposed,and the simulation results showed that although the spatial characteristics are not changed,the uniformity of the alumina content was markedly improved.
基金the financial supports from the National Natural Science Foundation of China(Nos.51974373,51874365,62133016)the Major Scientific and Technological Innovation Projects of Shandong Province,China(No.2019JZZY020123)the Fundamental Research Funds for the Central Universities of Central South University,China(No.2019zzts242)。
文摘In view of the unclear cause of perfluorocarbons(PFCs)emission in the anode effect stage of aluminum electrolysis,the microscopic formation mechanism of PFCs was studied by density functional theory calculation and X-ray photoelectron spectroscopy(XPS).It is found that the discharge of fluorine containing anions([F]−)on carbon anode first causes the substitution of C—H by C—F and further results in the saturation of aromatic C—C bonds,leading to the appearance of—CF_(3)or—C_(2)F_(5)group through six-carbon-ring opening.Elimination of—CF_(3)and—C_(2)F_(5) with F atom could be a likely mechanism of CF_(4) and C_(2)F_(6) formation.XPS results confirm that different types of—CF_(x) group can be formed on anode surface during electrolysis,and the possibility that[F]−discharges continuously at the C edge and finally forms different C—F bonds in quantum mechanical calculation was verified.
文摘Multiple sclerosis （MS） is a chronic inflammatory demyelinating disorder of the central nervous system characterized by episodic and progressive neurologic dysfunction resulting from inflammatory and autoimmune reactions. The underlying pathogenesis of MS remains largely unclear. However, it is currently accepted as a T cell-mediated autoimmune disease. Among other clinical manifestations, sexual dysfunction （SD） is a painful but still underreported and underdiagnosed symptom of the disorder. SD in MS patients may result from a complex set of conditions and may be associated with multiple anatomic, physiologic, biologic, medical and psychological factors. SD arises primarily from lesions affecting the neural pathways involved in physiologic function. In addition, psychological factors, the side effects of medications and physical symptoms such as fatigue, muscular weakness, menstrual changes, pain and concerns about bladder and bowel incontinence may also be involved. Since MS primarily affects young people, SD secondary to MS may have a great impact on quality of life. Thus, maintaining a healthy sexual life with MS is an important priority. The treatment of SD requires multidisciDlinarv teamwork and coooeration amone specialists,individual patients, partners and the society.
基金This research has been made possible by contributions from the Natural Sciences and Engineering Research Council(NSERC)/Energi Simulation Industrial Research Chair in Reservoir Simulation and the Alberta Innovates(iCore)Chair in Reservoir ModelingThis research was supported by the Science Foundation of China University of Petroleum,Beijing(No.2462023BJRC001)the National Natural Science Foundation of China Joint Fund Key Support Project(No.U19B6003).
文摘A comprehensive dataset from 594 fracturing wells throughout the Duvernay Formation near Fox Creek, Alberta, is collected to quantify the influences of geological, geomechanical, and operational features on the distribution and magnitude of hydraulic fracturing-induced seismicity. An integrated machine learning-based investigation is conducted to systematically evaluate multiple factors that contribute to induced seismicity. Feature importance indicates that a distance to fault, a distance to basement, minimum principal stress, cumulative fluid injection, initial formation pressure, and the number of fracturing stages are among significant model predictors. Our seismicity prediction map matches the observed spatial seismicity, and the prediction model successfully guides the fracturing job size of a new well to reduce seismicity risks. This study can apply to mitigating potential seismicity risks in other seismicity-frequent regions.
文摘Recent advances in neuroimaging contribute a lot to the accurate diagnosis and evaluation of cerebrovascular diseases. To explore the relationship among blood perfusion, metabolism and brain structure integrity, 6 Chinese transient ischemic attack (TIA) patients with middle cerebral artery (MCA) stenosis were examined by xenon-enhanced computed tomography (Xe-CT), magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI) to compare cerebral blood flow (CBF) values, (choline + creatine)/ N-acetyl aspartate [(Cho + Cr)/NAA] values and fractional anisotropy (FA) values in the MCA territory. Our results showed that CBF values significantly decreased in the ipsilateral basal ganglion regions in all 5 cases with unilateral MCA stenosis, with a corresponding decrease of FA values in the same region. In conclusion, decreased blood perfusion may indicate nerve fibre damage in the dominating regions of stenosed arteries.
文摘A previously healthy 19 year-old college student presented with abrupt onset of nausea, vomiting, dizziness and vertigo, and progressively worsened with hoarseness, and swallowing disturbance, imbalance, numbness of right face and left-side limbs and trunk. The diagnosis of Wallenberg syndrome was established by clinical manifestations and medullary hemorrhage by combination use of magnetic resonance imaging (MRI) with computed tomography (CT). Supportive treatment was given to the patient and there was considerable improvement in his neurologic status after 40 days treatment.
基金supported by the National Key R&D Program of China(Grant No.2017YFA0402503)。
文摘Tungsten(W),as a plasma-facing material,is subjected to high fluence plasma,resulting in both radiation damage and deuterium(D)retention.This study explores the blistering behavior and D supersaturated layers in both pre-damaged and undamaged W samples.To achieve a uniform damage profile similar to neutron irradiation,carbon(C)ions with multiple energies and angles were employed.The samples were further irradiated with low-energy D ions under two fluences at temperatures from~380 to 640 K.Using various experimental techniques,we found that pre-damaged W samples can effectively suppress the formation of blistering and lower the threshold temperature at which the surface remains free of blistering.We also observed the prominent D supersaturated peaks within the depth of 20 nm in both pre-damaged and undamaged W.Furthermore,a close correlation between blistering and the D supersaturation was investigated.The results suggest that neutron irradiation in the fusion reactors could increase the critical D concentration for blistering,while a greater depth of damage facilitated the inward diffusion of D,thereby reducing the D concentration gradient and alleviating surface blistering.
文摘Life sciences,a group of disciplines dedicated to exploring biological phenomena and elucidating the principles underlying biological activities,span multiple levels of research ranging from molecules to cells,tissues,organs,individuals,and populations.It represents one of the most dynamic frontiers in contemporary scientific research[1].In recent years,China has made remarkable progress in scientific research investment and development.China’s basic research funds reached 221.2 billion yuan in 2023,representing a 9.3%increase over the previous year.
基金Supported by Beijing Municipal Education Commission Urban Agriculture Disciplines Development Project (XK1001900553)Program for new Century Excellent Talents in University of China (NCET-06-0108).
文摘In this study, the genetic diversity of 51 cultivars in the primary core collection of peach （Prunus persica （L.） Batsch） was evaluated by using simple sequence repeats （SSRs）. The phylogenetic relationships and the evolutionary history among different cultivars were determined on the basis of SSR data. Twenty-two polymorphic SSR primer pairs were selected, and a total of 111 alleles were identified in the 51 cultivars, with an average of 5 alleles per locus. According to traditional Chinese classification of peach cultivars, the 51 cultivars in the peach primary core collection belong to six variety groups. The SSR analysis revealed that the levels of the genetic diversity within each variety group were ranked as Sweet peach 〉 Crisp peach 〉 Flat peach 〉 Nectarine 〉 Honey Peach 〉 Yellow fleshed peach. The genetic diversity among the Chinese cultivars was higher than that among the introduced cultivars. Cluster analysis by the unweighted pair group method with arithmetic averaging （UPGMA） placed the 51 cultivars into five linkage clusters. Cultivar members from the same variety group were distributed in different UPGMA clusters and some members from different variety groups were placed under the same cluster. Different variety groups could not be differentiated in accordance with SSR markers. The SSR analysis revealed rich genetic diversity in the peach primary core collection, representative of genetic resources of peach.
基金supported by grants from China Scholarship Council
文摘Objective Cerebral autoregulation （CA） is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure. CA can be evaluated by dynamic monitoring of cerebral blood flow velocity （CBFV） with transcranial Doppler sonography （TCD）. The present study aimed to explore CA in chronic anxiety. Methods Subjects with Hamilton anxiety scale scores 〉14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD. Results In both the anxious and the healthy subjects, the mean CBFV was significantly lower in the upright position than when supine. However, the CBFV changes from supine to upright differed between the anxious and the healthy groups. Anxious subjects showed more pronounced decreases in CBFV with abrupt standing. Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety; anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change. Given the fact that anxiety and impaired CA are associated with cardiovascular disease, early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population, and improve the primary prevention of cardiovascular disease.
基金This research was sponsored by the National Key Research and Development Project(SQ2018YFC100243)National Key Research and Development Project(2016YFC1000302)+4 种基金National Key Research and Developmental Program of China(2018YFC1003600)Young Scientists Fund of the National NaturalScience Foundation of China(Grant No.81601272)Clinical MedicinePlusX-Young Scholars Project,Peking University(Grant No.2102018237)Beijing Municipal Natural Science Foundation(7182177)National KeyResearch and Development Program of China(Grant No.2017YFC1002001).
文摘The aim of our study was to compare the sperm retrieval rates(SRRs)and clinical outcomes of patients with different causes of azoospermia who underwent microdissection testicular sperm extraction-intracytoplasmic sperm injection(micro-TESE-ICSI).We conducted a retrospective study at the Reproductive Medicine Center of Peking University Third Hospital in Beijing,China,from January 2014 to December 2017.This study examined 769 patients with nonobstructive azoospermia who underwent 347 cycles of micro-TESE-ICSI.Patients with azoospermia were classified into Group A(Klinefelter syndrome,n=284,125 cycles),Group B(azoospermia Y chromosome factor c[AZFc]microdeletion,n=91,64 cycles),Group C(cryptorchidism,n=52,39 cycles),Group D(previous mumps and bilateral orchitis,n=23,23 cycles),and Group E(idiopathic azoospermia,n=319,96 cycles).Clinical characteristics,SRR,embryonic development,and pregnancy outcomes of the patients were compared between all groups.Patients in Group D had the highest and most successful SRR.The average SRR for all patients was 46.0%.The rates of clinical pregnancy,implantation,and live birth in Group D were 78.3%,65.0%,and 74.0%,respectively,which were higher than those in all other groups(P<0.05).Group B patients had the lowest clinical pregnancy,implantation,and live birth rates of all groups(P<0.05).No differences were found in the miscarriage rate or birth defects among the groups(P>0.05).Patients with orchitis had the highest SRR and best clinical outcomes.Although AZFc microdeletion patients had a higher SRR,their clinical outcomes were worse.
基金This research was supported by the Key Program of National Natural Science Foundation of China(Grant No.81630087 and 81601272)the National Key Research and Development Program of China(Grant No.2017YFC1002001).All these sponsors had no role in the study design,in the collection,analysis,and interpretation of data,in the writing of the report,or in the decision to submit the article for publication.
文摘Previous studies suggest that air pollution has a negative effect on semen quality.However,most studies are cross-sectional and the results are controversial.This study investigated the associations between air pollutants(PM25,PM10,SO2,NO2,CO,and O3)and seme n quality among sperm donation candidates,especially when the air pollution was artificially con trolled in Beijing,China.We an a lyzed 8945 semen samples in the human sperm bank of Peki ng Un iversity Third Hospital(Beijing,China)from October 2015 to May 2018.Air pollution data during the entire period(0-90 days prior)and key stages(0-9,10-14,and 70-90 days prior)of sperm development were collected from the China National Environmental Monitoring Centre.The association between air pollutants and seme n parameters(sperm con centrati on and progressive motility)was an a lyzed by a mixed model adjusted for age,abstinence duration,month,and average ambient temperature.Only O3 during key stages of 0-9 days and 10-14 days and the entire period was negatively associated with sperm concentration between 2015 and 2018(P v 0.01).During the period of air pollution control from November 2017 to January 2018,except for the in crease in O3 concentration,other five pollutants'concentrations decreased compared to those in previous years.In this period,the sperm concentration decreased(P<0.001).During the pollution-control period,O3 exposure 10-14 days prior was negatively associated with sperm concentration(95%Cl:-0.399—0.111;P<0.001).No significant association was found between the other five pollutants and semen quality during that period?Our study suggested that only O3 exposure was harmful to semen quality.Therefore,O3 should not be neglected during pollution control operation.
基金This research was sponsored by the National Key Research and Development Projects(No.2018YFC1003600,2016YFC1000302,2017YFC1002001 and SQ2018YFC100243)the Clinical Medicine PlusX Young Scholars Project,Peking University(No.2102018237)the Beijing Municipal Natural Science Foundation(No.7182177).
文摘We performed this study to evaluate the clinical outcomes of microdissection testicular sperm extraction-intracytoplasmic sperm injection(micro-TESE-ICSI)treatment that used fresh or cryopreserved sperm in patients with nonobstructive azoospermia(NOA).A total of 338 NOA patients with 344 consecutive cycles received treatment in the reproductive medicine center of Peking University Third Hospital in Beijing,China,from January 2014 to December 2017.Fresh oocytes and fresh sperm were used in 222 patients with 234 cycles(Group A).Fresh oocytes and cryopreserved sperm were used in 116 patients with 110 cycles(Group B).We compared patient characteristics,embryonic development,and pregnancy outcomes between Groups A and B.There was no statistical difference in the patient characteristics,and no differences were observed with fertilization or quality embryo rates between Groups A and B.The rates of clinical pregnancy and live birth were both higher for Group A than those for Group B(both P<0.05).In conclusion,fresh testicular sperm appears to produce better ICSI outcomes than cryopreserved testicular sperm in patients with NOA.
基金The authors acknowledge financial support from the Key Project of National Natural Science Foundation of China（U1660206） and General Program of National Natural Science Foundation of China （51674002）.
文摘The emission of dioxins from the iron ore sintering process is the largest emission source of dioxins, and the reduction in dioxin emission from the iron ore sintering process to the environment is increasingly important. Three approaches to control the emission of dioxins were reviewed： source control, process control, and terminal control. Among them, two terminal control technologies, activated carbon adsorption and selective reduction technology, were discussed in detail. Following a comparison of the reduction technologies, the terminal control method was indicated as the key technology to achieve good control of dioxins during the sintering process. For the technical characteristics of the sintering process and flue gas, multiple methods should be collectively considered, and the most suitable method may be addition of inhibitors ＋ ultra-clean dust collection （electrostatic precipitation/bag filter） ＋ desulphurization ＋ selective catalytic reduction to sufficiently remove multiple pollutants, which provides a direction for the cooperative disposal of flue gas pollutants in future.
文摘Objective: To present our treatment experiences and the follow-up data of patients with paradoxical embolism (PDE). Methods: The clinical characteristics, management, and follow-up data of all included patients who were diagnosed with PDE at Fuwai Hospital from January 1994 to October 2015 were recorded. Results: Twelve patients were included;all had a pulmonary embolism, and 8 had deep venous thrombosis. The artery embolisms involved the cerebral artery (7 patients), renal artery (2 patients), mesentery artery (2 patients), popliteal artery (1 patient), descending aorta thrombus (1 patient), and thrombus-straddled patent foramen ovale (PFO) (1 patient). PFO was found in 3 cases. One patient underwent thrombectomy and PFO closure;Six patients received thrombolysis;and 3 patients were implanted with a vena cava filter. Long-term anticoagulation with warfarin was recommended for each patient. One patient died from ventricular fibrillation despite cardiopulmonary resuscitation. Eleven patients were discharged with improvements. No late mortality occurred in 8 patients with a complete follow-up of 10.6-17.7 years. One had a recurrent deep venous thrombosis. No patient had a recurrent pulmonary or arterial embolism. Two patients changed their treatment from warfarin to aspirin;others remained on warfarin. Only 1 case had an occasional gum bleeding. Conclusions: PDE treatment including thrombolysis, anticoagulation, and embolectomy should be individualized. We recom-mend long-term anticoagulation therapy to prevent the recurrence of PDE, especially to those with an intracardiac communication or persistent risk factors for re-thrombosis.
