The anti-sliding stability of a gravity dam along its foundation surface is a key problem in the design of gravity dams.In this study,a sensitivity analysis framework was proposed for investigating the factors affecti...The anti-sliding stability of a gravity dam along its foundation surface is a key problem in the design of gravity dams.In this study,a sensitivity analysis framework was proposed for investigating the factors affecting gravity dam anti-sliding stability along the foundation surface.According to the design specifications,the loads and factors affecting the stability of a gravity dam were comprehensively selected.Afterwards,the sensitivity of the factors was preliminarily analyzed using the Sobol method with Latin hypercube sampling.Then,the results of the sensitivity analysis were verified with those obtained using the Garson method.Finally,the effects of different sampling methods,probability distribution types of factor samples,and ranges of factor values on the analysis results were evaluated.A case study of a typical gravity dam in Yunnan Province of China showed that the dominant factors affecting the gravity dam anti-sliding stability were the anti-shear cohesion,upstream and downstream water levels,anti-shear friction coefficient,uplift pressure reduction coefficient,concrete density,and silt height.Choice of sampling methods showed no significant effect,but the probability distribution type and the range of factor values greatly affected the analysis results.Therefore,these two elements should be sufficiently considered to improve the reliability of the dam anti-sliding stability analysis.展开更多
Ex situ characterization techniques in molecular beam epitaxy(MBE)have inherent limitations,such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber.In recent years...Ex situ characterization techniques in molecular beam epitaxy(MBE)have inherent limitations,such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber.In recent years,the need for improved accuracy and reliability in measurement has driven the increasing adoption of in situ characterization techniques.These techniques,such as reflection high-energy electron diffraction,scanning tunneling microscopy,and X-ray photoelectron spectroscopy,allow direct observation of film growth processes in real time without exposing the sample to air,hence offering insights into the growth mechanisms of epitaxial films with controlled properties.By combining multiple in situ characterization techniques with MBE,researchers can better understand film growth processes,realizing novel materials with customized properties and extensive applications.This review aims to overview the benefits and achievements of in situ characterization techniques in MBE and their applications for material science research.In addition,through further analysis of these techniques regarding their challenges and potential solutions,particularly highlighting the assistance of machine learning to correlate in situ characterization with other material information,we hope to provide a guideline for future efforts in the development of novel monitoring and control schemes for MBE growth processes with improved material properties.展开更多
Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberel...Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.展开更多
Infertility represents a significant health concern,with sperm quantity and quality being crucial determinants of male fertility.Oligoasthenoteratozoospermia(OAT)is characterized by reduced sperm motility,lower sperm ...Infertility represents a significant health concern,with sperm quantity and quality being crucial determinants of male fertility.Oligoasthenoteratozoospermia(OAT)is characterized by reduced sperm motility,lower sperm concentration,and morphological abnormalities in sperm heads and flagella.Although variants in several genes have been implicated in OAT,its genetic etiologies and pathogenetic mechanisms remain inadequately understood.In this study,we identified a homozygous nonsense mutation(c.916C>T,p.Arg306*)in the coiled-coil domain containing 146(CCDC146)gene in an infertile male patient with OAT.This mutation resulted in the production of a truncated CCDC146 protein(amino acids 1-305),retaining only two out of five coiled-coil domains.To validate the pathogenicity of the CCDC146 mutation,we generated a mouse model(Ccdc146^(mut/mut))with a similar mutation to that of the patient.Consistently,the Ccdc146mut/mut mice exhibited infertility,characterized by significantly reduced sperm counts,diminished motility,and multiple defects in sperm heads and flagella.Furthermore,the levels of axonemal proteins,including DNAH17,DNAH1,and SPAG6,were significantly reduced in the sperm of Ccdc146^(mut/mut) mice.Additionally,both human and mouse CCDC146 interacted with intraflagellar transport protein 20(IFT20),but this interaction was lost in the mutated versions,leading to the degradation of IFT20.This study identified a novel deleterious homozygous nonsense mutation in CCDC146 that causes male infertility,potentially by disrupting axonemal protein transportation.These findings offer valuable insights for genetic counseling and understanding the mechanisms underlying CCDC146 mutant-associated infertility in human males.展开更多
Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a promine...Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a prominent component of Paeonia lactiflora Pall.,has demonstrated the ability to restore barrier function in UC mice,but the precise mechanism remains unclear.In this study,we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s.C57BL/6 mice were subjected to random allocation into 7 distinct groups,namely the control group,the 2%dextran sodium sulfate(DSS)group,the paeoniflorin groups(25,50,and 100 mg/kg),the anti-tumor necrosis factor-like ligand 1A(anti-TL1A)antibody group,and the IgG group.We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using Western blot and flow cytometry,respectively.Meanwhile,DR3-overexpressing MNK-3 cells and 2%DSS-induced Rag1^(-/-)mice were used for verification.The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier.Simultaneously,paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines(interleukin-17A,granulocyte-macrophage colony stimulating factor,and interleukin-22).Alternatively,paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage independently of the adaptive immune system.We additionally confirmed that paeoniflorin-conditioned medium(CM)restored the expression of tight junctions in Caco-2 cells via coculture.In conclusion,paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner,and its mechanism is associated with the inhibition of the DR3 signaling pathway.展开更多
Gastrochilus is an orchid genus containing 73 species of mainly epiphytic on trees or rocks in mountain forests of tropical and subtropical Asia.Previous phylogenetic analyses and morphological assessments have failed...Gastrochilus is an orchid genus containing 73 species of mainly epiphytic on trees or rocks in mountain forests of tropical and subtropical Asia.Previous phylogenetic analyses and morphological assessments have failed to produce a well-resolved phylogeny at the infrageneric level.In the present study,a new infrageneric classification of Gastrochilus is proposed based on thoroughly morphological and phylogenetic analyses based on 52 species.Our phylogenetic analysis divided the genus into six sections including three new sections,G.sect.Pseudodistichi,G.sect.Brachycaules and G.sect.Acinacifolii.We also reinstate G.suavis to the specific rank.Furthermore,two new species,G.armeniacus Jun Y.Zhang,B.Xu&Yue H.Cheng and G.minjiangensis Jun Y.Zhang,B.Xu&Yue H.Cheng,are described and illustrated.A key to six sections of the genus is presented.展开更多
The structural integrity of the sperm flagellum is essential for proper sperm function.Flagellar defects can result in male infertility,yet the precise mechanisms underlying this relationship are not fully understood....The structural integrity of the sperm flagellum is essential for proper sperm function.Flagellar defects can result in male infertility,yet the precise mechanisms underlying this relationship are not fully understood.CCDC181,a coiled-coil domain-containing protein,is known to localize on sperm flagella and at the basal regions of motile cilia.Despite this knowledge,the specific functions of CCDC181 in flagellum biogenesis remain unclear.In this study,Ccdc181 knockout mice were generated.The absence of CCDC181 led to defective sperm head shaping and flagellum formation.Furthermore,the Ccdc181 knockout mice exhibited extremely low sperm counts,grossly aberrant sperm morphologies,markedly diminished sperm motility,and typical multiple morphological abnormalities of the flagella(MMAF).Additionally,an interaction between CCDC181 and the MMAF-related protein LRRC46 was identified,with CCDC181 regulating the localization of LRRC46 within sperm flagella.These findings suggest that CCDC181 plays a crucial role in both manchette formation and sperm flagellum biogenesis.展开更多
The ocean conditions beneath the ice cover play a key role in understanding the sea ice mass balance in the polar regions.An integrated high-frequency ice-ocean observation system,including Acoustic Doppler Velocimete...The ocean conditions beneath the ice cover play a key role in understanding the sea ice mass balance in the polar regions.An integrated high-frequency ice-ocean observation system,including Acoustic Doppler Velocimeter,Conductivity-Temperature-Depth Sensor,and Sea Ice Mass Balance Array(SIMBA),was deployed in the landfast ice region close to the Chinese Zhongshan Station in Antarctica.A sudden ocean warming of 0.14℃(p<0.01)was observed beneath early-frozen landfast ice,from(−1.60±0.03)℃during April 16-19 to(−1.46±0.07)℃during April 20-23,2021,which is the only significant warming event in the nearly 8-month records.The sudden ocean warming brought a double rise in oceanic heat flux,from(21.7±11.1)W/m^(2) during April 16-19 to(44.8±21.3)W/m^(2) during April 20-23,2021,which shifted the original growth phase at the ice bottom,leading to a 2 cm melting,as shown from SIMBA and borehole observations.Simultaneously,the slowdown of ice bottom freezing decreased salt rejection,and the daily trend of observed ocean salinity changed from+0.02 d^(-1) during April 16-19,2021 to+0.003 d^(-1) during April 20-23,2021.The potential reasons are increased air temperature due to the transit cyclones and the weakened vertical ocean mixing due to the tide phase transformation from semi-diurnal to diurnal.The high-frequency observations within the ice-ocean boundary layer enhance the comprehensive investigation of the ocean’s influence on ice evolution at a daily scale.展开更多
As the second of Earth's Trojan asteroids, 2020 XL_(5) is worthy of rendezvous and even sample return missions in many aspects. In this paper, a rendezvous mission to Earth's second Trojan asteroid 2020 XL_(5)...As the second of Earth's Trojan asteroids, 2020 XL_(5) is worthy of rendezvous and even sample return missions in many aspects. In this paper, a rendezvous mission to Earth's second Trojan asteroid 2020 XL_(5) is proposed.However, due to its high inclination and large eccentricity, direct impulsive transfer requires large amounts of fuel consumption. To address this challenge, we explore the benefits of electric propulsion and multi-gravity assist techniques for interplanetary missions. These two techniques are integrated in this mission design. The design of a low-thrust gravity-assist(LTGA) trajectory in multi-body dynamics is thoroughly investigated,which is a complex process. A comprehensive framework including three steps is presented here for optimization of LTGA trajectories in multi-body dynamics. The rendezvous mission to 2020 XL_(5) is designed with this three-step approach. The most effective transfer sequence among the outcomes involves Earth–Venus–Earth–Venus-2020 XL_(5). Numerical results indicate that the combination of electric propulsion and multi-gravity assists can greatly reduce the fuel consumption, with fuel consumption of 9.03%, making it a highly favorable choice for this rendezvous mission.展开更多
Subject identification via the subject’s gait is challenging due to variations in the subject’s carrying and dressing conditions in real-life scenes.This paper proposes a novel targeted 3-dimensional(3D)gait model(3...Subject identification via the subject’s gait is challenging due to variations in the subject’s carrying and dressing conditions in real-life scenes.This paper proposes a novel targeted 3-dimensional(3D)gait model(3DGait)represented by a set of interpretable 3DGait descriptors based on a 3D parametric body model.The 3DGait descriptors are utilised as invariant gait features in the 3DGait recognition method to address object carrying and dressing.The 3DGait recognitionmethod involves 2-dimensional(2D)to 3DGaitdata learningbasedon3Dvirtual samples,a semantic gait parameter estimation Long Short Time Memory(LSTM)network(3D-SGPE-LSTM),a feature fusion deep model based on a multi-set canonical correlation analysis,and SoftMax recognition network.First,a sensory experiment based on 3D body shape and pose deformation with 3D virtual dressing is used to fit 3DGait onto the given 2D gait images.3Dinterpretable semantic parameters control the 3D morphing and dressing involved.Similarity degree measurement determines the semantic descriptors of 2D gait images of subjects with various shapes,poses and styles.Second,using the 2D gait images as input and the subjects’corresponding 3D semantic descriptors as output,an end-to-end 3D-SGPE-LSTM is constructed and trained.Third,body shape,pose and external gait factors(3D-eFactors)are estimated using the 3D-SGPE-LSTM model to create a set of interpretable gait descriptors to represent the 3DGait Model,i.e.,3D intrinsic semantic shape descriptor(3DShape);3D skeleton-based gait pose descriptor(3D-Pose)and 3D dressing with other 3D-eFators.Finally,the 3D-Shape and 3D-Pose descriptors are coupled to a unified pattern space by learning prior knowledge from the 3D-eFators.Practical research on CASIA B,CMU MoBo,TUM GAID and GPJATK databases shows that 3DGait is robust against object carrying and dressing variations,especially under multi-cross variations.展开更多
BACKGROUND The recently introduced ultrasonic flow ratio(UFR),is a novel fast computational method to derive fractional flow reserve(FFR)from intravascular ultrasound(IVUS)images.In the present study,we evaluate the d...BACKGROUND The recently introduced ultrasonic flow ratio(UFR),is a novel fast computational method to derive fractional flow reserve(FFR)from intravascular ultrasound(IVUS)images.In the present study,we evaluate the diagnostic performance of UFR in patients with intermediate left main(LM)stenosis.METHODS This is a prospective,single center study enrolling consecutive patients with presence of intermediated LM lesions(diameter stenosis of 30%-80%by visual estimation)underwent IVUS and FFR measurement.An independent core laboratory assessed offline UFR and IVUS-derived minimal lumen area(MLA)in a blinded fashion.RESULTS Both UFR and FFR were successfully achieved in 41 LM patients(mean age,62.0±9.9 years,46.3%diabetes).An acceptable correlation between UFR and FFR was identified(r=0.688,P<0.0001),with an absolute numerical difference of 0.03(standard difference:0.01).The area under the curve(AUC)in diagnosis of physiologically significant coronary stenosis for UFR was 0.94(95%CI:0.87-1.01),which was significantly higher than angiographic identified stenosis>50%(AUC=0.66,P<0.001)and numerically higher than IVUS-derived MLA(AUC=0.82;P=0.09).Patient level diagnostic accuracy,sensitivity and specificity for UFR to identify FFR≤0.80 was 82.9%(95%CI:70.2-95.7),93.1%(95%CI:82.2-100.0),58.3%(95%CI:26.3-90.4),respectively.CONCLUSION In patients with intermediate LM diseases,UFR was proved to be associated with acceptable correlation and high accuracy with pressure wire-based FFR as standard reference.The present study supports the use of UFR for functional evaluation of intermediate LM stenosis.展开更多
Objectives To evaluate the feasibility and safety of a second generation robotic percutaneous coronary intervention(R-PCI)system in China.Background Robotic PCI has been shown to be an effective method for conducting ...Objectives To evaluate the feasibility and safety of a second generation robotic percutaneous coronary intervention(R-PCI)system in China.Background Robotic PCI has been shown to be an effective method for conducting coronary interventions.It has further benefits of more accurate lesion measurement,improved stent deployment,reduced incidence of geographic miss and reduction of operator radiation exposure.Methods This single center evaluation enrolled 10 consecutive patients who had been selected for PCI.Clinical success was defined as residual stenosis<30%and no in-hospital major adverse cardiovascular events.Learning curve effect was assessed by comparing efficiency metrics of early vs.later cases.Results Eleven lesions were treated all successfully without manual interruption or MACE events.Most lesions(63%)were ACC/AHA class B2 and C.Mean procedure time was 57.7±26.4 min,however two procedures were part of live demonstrations.Excluding the two live cases,the mean procedure time was 51.8±23.7 min.Procedural efficiency tended to improve from early cases to later cases based on PCI time(48.3±32.9 vs.25.5±13.0 min,P=0.27),fluoroscopy time(20.3±8.2 vs.12.5±4.6 min,P=0.16),contrast volume(145.0±28.9 vs.102.5±17.1 mL,P=0.05)and Air Kerma dose(1932±978 vs.1007±70 mGy,P=0.31).Conclusions Second generation robotic PCI was safe,effective and there were trends toward improvements in procedural efficiency during this early experience in China.展开更多
Optoelectronic devices on silicon substrates are essential not only to the optoelectronic integrated circuit but also to low-cost lasers,large-area detectors,and so forth.Although heterogeneous integration of III-V se...Optoelectronic devices on silicon substrates are essential not only to the optoelectronic integrated circuit but also to low-cost lasers,large-area detectors,and so forth.Although heterogeneous integration of III-V semiconductors on Si has been welldeveloped,the thermal dissipation issue and the complicated fabrication process still hinders the development of these devices.The monolithic growth of III-V materials on Si has also been demonstrated by applying complicated buffer layers or interlayers.On the other hand,the growth of lattice-matched B-doped group-III-V materials is an attractive area of research.However,due to the difficulty in growth,the development is still relatively slow.Herein,we present a comprehensive review of the recent achievements in this field.We summarize and discuss the conditions and mechanisms involved in growing B-doped group-III-V materials.The unique surface morphology,crystallinity,and optical properties of the epitaxy correlating with their growth conditions are discussed,along with their respective optoelectronic applications.Finally,we detail the obstacles and challenges to exploit the potential for such practical applications fully.展开更多
BACKGROUND: We aim to investigate effects of metabolic syndrome on onset age and long-termoutcomes in patients with acute coronary syndrome (ACS).METHODS: Patients with ACS (n=6,431) who underwent percutaneous coronar...BACKGROUND: We aim to investigate effects of metabolic syndrome on onset age and long-termoutcomes in patients with acute coronary syndrome (ACS).METHODS: Patients with ACS (n=6,431) who underwent percutaneous coronary interventionfrom January to December 2013 were enrolled. After excluding patients with previous coronary arterydisease, 1,558 patients were diagnosed with early-onset ACS (men aged ≤50 years;women aged≤60 years) and 3,044 patients with late-onset ACS. Baseline characteristics and five-year clinicaloutcomes were measured.RESULTS: Body mass index, triglyceride, low-density lipoprotein cholesterol, and uric acidconcentrations were significantly higher, while the high-density lipoprotein cholesterol (HDL-C)concentration was lower in the early-onset ACS group (P<0.001). Multivariate logistic regression revealedobesity (odds ratio [OR] 1.590, 95% confi dence interval [CI] 1.345–1.881), hypertriglyceridemia (OR 1.403,95% CI 1.185–1.660), and low HDL-C (OR 1.464, 95% CI 1.231–1.742) as independent risk factorsfor early-onset ACS (all P<0.001). The fi ve-year follow-up showed that the incidences of all cause death(1.5% vs. 3.8%, P<0.001), cardiac death (1.1% vs. 2.0%, P=0.023), and recurrent stroke (2.2% vs. 4.2%,P<0.001) were lower, while bleeding events were more frequent in the early-onset ACS group. A subgroupanalysis showed higher incidences of recurrent myocardial infarction (MI) and revascularization in patientswith early-onset ACS and metabolic syndrome.CONCLUSIONS: Obesity, hypertriglyceridemia, and lower HDL-C level are independent riskfactors for early-onset ACS, recurrent MI, and revascularization. The control of metabolic syndromemay reduce the incidence of early-onset ACS and improve the long-term prognosis.展开更多
The present study evaluated the expression of key molecules and the status of DNA in both oral squamous cell carcinoma（OSCC） and adjacent tissues to establish a molecular surgical boundary and provide a cancer progr...The present study evaluated the expression of key molecules and the status of DNA in both oral squamous cell carcinoma（OSCC） and adjacent tissues to establish a molecular surgical boundary and provide a cancer progression model. Biopsy samples from 50 OSCC patients were divided into T（cancer）, P1（0–0.5 cm）, P2（0.5–1 cm）, P3（1–1.5 cm） and P4（1.5–2 cm） groups based on the distances from the visible boundary of the primary focus. Twenty samples of normal mucosa were used as controls. We used immunohistochemical staining and flow cytometry to evaluate p53, p21CIP1/WAF1, e IF4 E and Ki-67 expression and to determine DNA status, respectively. Sub-mucosal invasion was present in the P1 and P2 groups as determined by haematoxylin and eosin staining.Mutant p53 expression decreased gradually from cancerous to normal mucosae, whereas p21CIP1/WAF1 expression displayed an opposite trend. e IF4 E expression decreased from cancerous to normal mucosae. Ki-67 expression, the heteroploidy ratio, S-phase fraction and proliferative index decreased gradually with the distance from the tumour centre. Based on these results, we suggest that the resection boundary in OSCC surgery should be beyond 2 cm from the tumour. Additionally, the adjacent tissues of the primary focus could be used as a model for assessing cancer progression.展开更多
A novel amperometric biosensor for the detection of hydrogen peroxide is described. The biosensor was constructed by electrodepositing HRP/PPy membrane on the surface of ferrocenecarboxylic acid mediated sol-gel deriv...A novel amperometric biosensor for the detection of hydrogen peroxide is described. The biosensor was constructed by electrodepositing HRP/PPy membrane on the surface of ferrocenecarboxylic acid mediated sol-gel derived composite carbon electrode. The biosensor gives response to hydrogen peroxide in a few seconds with detection limit of 5×10-7 mol·L-1 （based on signal : noise=3）. Linear range is up to 0.2 mmol·L-1.展开更多
Both boron nitride(BN)and carbon(C)have sp,sp^(2)and sp^(3)hybridization modes,thus resulting in a variety of BN and C polymorphs with similar structures,such as hexagonal BN(hBN)and graphite,cubic BN(cBN)and diamond....Both boron nitride(BN)and carbon(C)have sp,sp^(2)and sp^(3)hybridization modes,thus resulting in a variety of BN and C polymorphs with similar structures,such as hexagonal BN(hBN)and graphite,cubic BN(cBN)and diamond.Here,five types of BN polymorph structures are proposed theoretically,inspired by the graphite-diamond hybrid structures discovered in a recent experiment.These BN polymorphs with graphite-diamond hybrid structures possess excellent mechanical properties with combined high hardness and high ductility,and also exhibit various electronic properties such as semi-conductivity,semi-metallicity,and even one-and two-dimensional conductivity,differing from known insulators hBN and cBN.The simulated diffraction patterns of these BN hybrid structures could account for the unsolved diffraction patterns of intermediate products composed of so-called“compressed hBN”and diamond-like BN,caused by phase transitions in previous experiments.Thus,this work provides a theoretical basis for the presence of these types of hybrid materials during phase transitions between graphite-like and diamond-like BN polymorphs.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52079120).
文摘The anti-sliding stability of a gravity dam along its foundation surface is a key problem in the design of gravity dams.In this study,a sensitivity analysis framework was proposed for investigating the factors affecting gravity dam anti-sliding stability along the foundation surface.According to the design specifications,the loads and factors affecting the stability of a gravity dam were comprehensively selected.Afterwards,the sensitivity of the factors was preliminarily analyzed using the Sobol method with Latin hypercube sampling.Then,the results of the sensitivity analysis were verified with those obtained using the Garson method.Finally,the effects of different sampling methods,probability distribution types of factor samples,and ranges of factor values on the analysis results were evaluated.A case study of a typical gravity dam in Yunnan Province of China showed that the dominant factors affecting the gravity dam anti-sliding stability were the anti-shear cohesion,upstream and downstream water levels,anti-shear friction coefficient,uplift pressure reduction coefficient,concrete density,and silt height.Choice of sampling methods showed no significant effect,but the probability distribution type and the range of factor values greatly affected the analysis results.Therefore,these two elements should be sufficiently considered to improve the reliability of the dam anti-sliding stability analysis.
基金supported by the National Key R&D Program of China(Grant No.2021YFB2206503)National Natural Science Foundation of China(Grant No.62274159)+1 种基金CAS Project for Young Scientists in Basic Research(Grant No.YSBR-056)the“Strategic Priority Research Program”of the Chinese Academy of Sciences(Grant No.XDB43010102).
文摘Ex situ characterization techniques in molecular beam epitaxy(MBE)have inherent limitations,such as being prone to sample contamination and unstable surfaces during sample transfer from the MBE chamber.In recent years,the need for improved accuracy and reliability in measurement has driven the increasing adoption of in situ characterization techniques.These techniques,such as reflection high-energy electron diffraction,scanning tunneling microscopy,and X-ray photoelectron spectroscopy,allow direct observation of film growth processes in real time without exposing the sample to air,hence offering insights into the growth mechanisms of epitaxial films with controlled properties.By combining multiple in situ characterization techniques with MBE,researchers can better understand film growth processes,realizing novel materials with customized properties and extensive applications.This review aims to overview the benefits and achievements of in situ characterization techniques in MBE and their applications for material science research.In addition,through further analysis of these techniques regarding their challenges and potential solutions,particularly highlighting the assistance of machine learning to correlate in situ characterization with other material information,we hope to provide a guideline for future efforts in the development of novel monitoring and control schemes for MBE growth processes with improved material properties.
基金supported by grants from the China Agriculture Research System(CARS-28-14)the Technical System of Fruit Industry in Anhui Province,China(AHCYTX-10)the Scientific Research Projects for Postgraduates of Anhui Universities,China(YJS20210207).
文摘Drought stress is a devastating natural disaster driven by the continuing intensification of global warming,which seriously threatens the productivity and quality of several horticultural crops,including pear.Gibberellins(GAs)play crucial roles in plant growth,development,and responses to drought stress.Previous studies have shown significant reductions of GA levels in plants under drought stress;however,our understanding of the intrinsic regulation mechanisms of GA-mediated drought stress in pear remains very limited.Here,we show that drought stress can impair the accumulation of bioactive GAs(BGAs),and subsequently identified PbrGA2ox1 as a chloroplast-localized GA deactivation gene.This gene was significantly induced by drought stress and abscisic acid(ABA)treatment,but was suppressed by GA_(3)treatment.PbrGA2ox1-overexpressing transgenic tobacco plants(Nicotiana benthamiana)exhibited enhanced tolerance to dehydration and drought stresses,whereas knock-down of PbrGA2ox1 in pear(Pyrus betulaefolia)by virus-induced gene silencing led to elevated drought sensitivity.Transgenic plants were hypersensitive to ABA,and had a lower BGAs content,enhanced reactive oxygen species(ROS)scavenging ability,and augmented ABA accumulation and signaling under drought stress compared to wild-type plants.However,the opposite effects were observed with PbrGA2ox1 silencing in pear.Moreover,exogenous GA_(3)treatment aggravated the ROS toxic effect and restrained ABA synthesis and signaling,resulting in the compromised drought tolerance of pear.In summary,our results shed light on the mechanism by which BGAs are eliminated in pear leaves under drought stress,providing further insights into the mechanism regulating the effects of GA on the drought tolerance of plants.
基金supported by the National Key Research and Developmental Program of China(2021YFC2700202,2022YFC2702601,2019YFA0802600,2022YFA0806303)National Natural Science Foundation of China(32470915,32000587,32270901,82171601)+1 种基金Global Select Project(DJK-LX-2022010)of the Institute of Health and Medicine,Hefei Comprehensive National Science Center,Joint Fund for New Medicine of USTC(YD9100002034)Scientific Research Foundation for Scholars of the First Affiliated Hospital of USTC(RC2023054)。
文摘Infertility represents a significant health concern,with sperm quantity and quality being crucial determinants of male fertility.Oligoasthenoteratozoospermia(OAT)is characterized by reduced sperm motility,lower sperm concentration,and morphological abnormalities in sperm heads and flagella.Although variants in several genes have been implicated in OAT,its genetic etiologies and pathogenetic mechanisms remain inadequately understood.In this study,we identified a homozygous nonsense mutation(c.916C>T,p.Arg306*)in the coiled-coil domain containing 146(CCDC146)gene in an infertile male patient with OAT.This mutation resulted in the production of a truncated CCDC146 protein(amino acids 1-305),retaining only two out of five coiled-coil domains.To validate the pathogenicity of the CCDC146 mutation,we generated a mouse model(Ccdc146^(mut/mut))with a similar mutation to that of the patient.Consistently,the Ccdc146mut/mut mice exhibited infertility,characterized by significantly reduced sperm counts,diminished motility,and multiple defects in sperm heads and flagella.Furthermore,the levels of axonemal proteins,including DNAH17,DNAH1,and SPAG6,were significantly reduced in the sperm of Ccdc146^(mut/mut) mice.Additionally,both human and mouse CCDC146 interacted with intraflagellar transport protein 20(IFT20),but this interaction was lost in the mutated versions,leading to the degradation of IFT20.This study identified a novel deleterious homozygous nonsense mutation in CCDC146 that causes male infertility,potentially by disrupting axonemal protein transportation.These findings offer valuable insights for genetic counseling and understanding the mechanisms underlying CCDC146 mutant-associated infertility in human males.
基金supported by the National Natural Science Foundation of China(Grant No.:82074092),Natural Science Foundation of Guangdong Province,China(Grant No.:2021A1515012219)Guangzhou University of Chinese Medicine“Double First-Class”and High-level University Discipline Collaborative Innovation Team Project,China(Grant No.:2021xk81) and Graduate Research Innovation Project of Guangzhou University of Chinese Medicine,China.
文摘Inhibiting the death receptor 3(DR3)signaling pathway in group 3 innate lymphoid cells(ILC3s)presents a promising approach for promoting mucosal repair in individuals with ulcerative colitis(UC).Paeoniflorin,a prominent component of Paeonia lactiflora Pall.,has demonstrated the ability to restore barrier function in UC mice,but the precise mechanism remains unclear.In this study,we aimed to delve into whether paeoniflorin may promote intestinal mucosal repair in chronic colitis by inhibiting DR3 signaling in ILC3s.C57BL/6 mice were subjected to random allocation into 7 distinct groups,namely the control group,the 2%dextran sodium sulfate(DSS)group,the paeoniflorin groups(25,50,and 100 mg/kg),the anti-tumor necrosis factor-like ligand 1A(anti-TL1A)antibody group,and the IgG group.We detected the expression of DR3 signaling pathway proteins and the proportion of ILC3s in the mouse colon using Western blot and flow cytometry,respectively.Meanwhile,DR3-overexpressing MNK-3 cells and 2%DSS-induced Rag1^(-/-)mice were used for verification.The results showed that paeoniflorin alleviated DSS-induced chronic colitis and repaired the intestinal mucosal barrier.Simultaneously,paeoniflorin inhibited the DR3 signaling pathway in ILC3s and regulated the content of cytokines(interleukin-17A,granulocyte-macrophage colony stimulating factor,and interleukin-22).Alternatively,paeoniflorin directly inhibited the DR3 signaling pathway in ILC3s to repair mucosal damage independently of the adaptive immune system.We additionally confirmed that paeoniflorin-conditioned medium(CM)restored the expression of tight junctions in Caco-2 cells via coculture.In conclusion,paeoniflorin ameliorates chronic colitis by enhancing the intestinal barrier in an ILC3-dependent manner,and its mechanism is associated with the inhibition of the DR3 signaling pathway.
基金supported by the National Key Research and Development Program of China (Grant No.2020YFE0203200)the Second Tibetan Plateau Scientific Expedition and Research (STEP)program (Grant Nos.2019QZKK0301&2019QZKK0502)+3 种基金2022 Central Finance Forestry Grassland Ecological Protection and Restoration National Park Subsidy Project2022-2023 Subsidy Projects of Prohibited Developmental Areas from the Transfer Payment of the National Key Ecological Functional Areas2023 Central financial protection and restoration funds for forestry and grassland ecologyWild Plants Sharing and Service Platform of Sichuan Province。
文摘Gastrochilus is an orchid genus containing 73 species of mainly epiphytic on trees or rocks in mountain forests of tropical and subtropical Asia.Previous phylogenetic analyses and morphological assessments have failed to produce a well-resolved phylogeny at the infrageneric level.In the present study,a new infrageneric classification of Gastrochilus is proposed based on thoroughly morphological and phylogenetic analyses based on 52 species.Our phylogenetic analysis divided the genus into six sections including three new sections,G.sect.Pseudodistichi,G.sect.Brachycaules and G.sect.Acinacifolii.We also reinstate G.suavis to the specific rank.Furthermore,two new species,G.armeniacus Jun Y.Zhang,B.Xu&Yue H.Cheng and G.minjiangensis Jun Y.Zhang,B.Xu&Yue H.Cheng,are described and illustrated.A key to six sections of the genus is presented.
基金supported by the National Natural Science Foundation of China(82071709,81971446,82171599,82374212)Global Select Project(DJK-LX-2022010)of the Institute of Health and Medicine,Hefei Comprehensive National Science CenterJoint Fund for New Medicine of USTC(YD9100002034)。
文摘The structural integrity of the sperm flagellum is essential for proper sperm function.Flagellar defects can result in male infertility,yet the precise mechanisms underlying this relationship are not fully understood.CCDC181,a coiled-coil domain-containing protein,is known to localize on sperm flagella and at the basal regions of motile cilia.Despite this knowledge,the specific functions of CCDC181 in flagellum biogenesis remain unclear.In this study,Ccdc181 knockout mice were generated.The absence of CCDC181 led to defective sperm head shaping and flagellum formation.Furthermore,the Ccdc181 knockout mice exhibited extremely low sperm counts,grossly aberrant sperm morphologies,markedly diminished sperm motility,and typical multiple morphological abnormalities of the flagella(MMAF).Additionally,an interaction between CCDC181 and the MMAF-related protein LRRC46 was identified,with CCDC181 regulating the localization of LRRC46 within sperm flagella.These findings suggest that CCDC181 plays a crucial role in both manchette formation and sperm flagellum biogenesis.
基金The National Natural Science Foundation of China under contract Nos 42276251,42211530033,and 41876212the Taishan Scholars Program.
文摘The ocean conditions beneath the ice cover play a key role in understanding the sea ice mass balance in the polar regions.An integrated high-frequency ice-ocean observation system,including Acoustic Doppler Velocimeter,Conductivity-Temperature-Depth Sensor,and Sea Ice Mass Balance Array(SIMBA),was deployed in the landfast ice region close to the Chinese Zhongshan Station in Antarctica.A sudden ocean warming of 0.14℃(p<0.01)was observed beneath early-frozen landfast ice,from(−1.60±0.03)℃during April 16-19 to(−1.46±0.07)℃during April 20-23,2021,which is the only significant warming event in the nearly 8-month records.The sudden ocean warming brought a double rise in oceanic heat flux,from(21.7±11.1)W/m^(2) during April 16-19 to(44.8±21.3)W/m^(2) during April 20-23,2021,which shifted the original growth phase at the ice bottom,leading to a 2 cm melting,as shown from SIMBA and borehole observations.Simultaneously,the slowdown of ice bottom freezing decreased salt rejection,and the daily trend of observed ocean salinity changed from+0.02 d^(-1) during April 16-19,2021 to+0.003 d^(-1) during April 20-23,2021.The potential reasons are increased air temperature due to the transit cyclones and the weakened vertical ocean mixing due to the tide phase transformation from semi-diurnal to diurnal.The high-frequency observations within the ice-ocean boundary layer enhance the comprehensive investigation of the ocean’s influence on ice evolution at a daily scale.
基金supported by Basic Research Project of China(grant No:JCKY2020110C096)the National Key R&D Program of China (grant No:2020YFC2201202)。
文摘As the second of Earth's Trojan asteroids, 2020 XL_(5) is worthy of rendezvous and even sample return missions in many aspects. In this paper, a rendezvous mission to Earth's second Trojan asteroid 2020 XL_(5) is proposed.However, due to its high inclination and large eccentricity, direct impulsive transfer requires large amounts of fuel consumption. To address this challenge, we explore the benefits of electric propulsion and multi-gravity assist techniques for interplanetary missions. These two techniques are integrated in this mission design. The design of a low-thrust gravity-assist(LTGA) trajectory in multi-body dynamics is thoroughly investigated,which is a complex process. A comprehensive framework including three steps is presented here for optimization of LTGA trajectories in multi-body dynamics. The rendezvous mission to 2020 XL_(5) is designed with this three-step approach. The most effective transfer sequence among the outcomes involves Earth–Venus–Earth–Venus-2020 XL_(5). Numerical results indicate that the combination of electric propulsion and multi-gravity assists can greatly reduce the fuel consumption, with fuel consumption of 9.03%, making it a highly favorable choice for this rendezvous mission.
基金funded by the Research Foundation of Education Bureau of Hunan Province,China,under Grant Number 21B0060the National Natural Science Foundation of China,under Grant Number 61701179.
文摘Subject identification via the subject’s gait is challenging due to variations in the subject’s carrying and dressing conditions in real-life scenes.This paper proposes a novel targeted 3-dimensional(3D)gait model(3DGait)represented by a set of interpretable 3DGait descriptors based on a 3D parametric body model.The 3DGait descriptors are utilised as invariant gait features in the 3DGait recognition method to address object carrying and dressing.The 3DGait recognitionmethod involves 2-dimensional(2D)to 3DGaitdata learningbasedon3Dvirtual samples,a semantic gait parameter estimation Long Short Time Memory(LSTM)network(3D-SGPE-LSTM),a feature fusion deep model based on a multi-set canonical correlation analysis,and SoftMax recognition network.First,a sensory experiment based on 3D body shape and pose deformation with 3D virtual dressing is used to fit 3DGait onto the given 2D gait images.3Dinterpretable semantic parameters control the 3D morphing and dressing involved.Similarity degree measurement determines the semantic descriptors of 2D gait images of subjects with various shapes,poses and styles.Second,using the 2D gait images as input and the subjects’corresponding 3D semantic descriptors as output,an end-to-end 3D-SGPE-LSTM is constructed and trained.Third,body shape,pose and external gait factors(3D-eFactors)are estimated using the 3D-SGPE-LSTM model to create a set of interpretable gait descriptors to represent the 3DGait Model,i.e.,3D intrinsic semantic shape descriptor(3DShape);3D skeleton-based gait pose descriptor(3D-Pose)and 3D dressing with other 3D-eFators.Finally,the 3D-Shape and 3D-Pose descriptors are coupled to a unified pattern space by learning prior knowledge from the 3D-eFators.Practical research on CASIA B,CMU MoBo,TUM GAID and GPJATK databases shows that 3DGait is robust against object carrying and dressing variations,especially under multi-cross variations.
基金supported by CAMS Innovation Fund for Medical Sciences(CIFMS)(2022–12M-C&TB-043).
文摘BACKGROUND The recently introduced ultrasonic flow ratio(UFR),is a novel fast computational method to derive fractional flow reserve(FFR)from intravascular ultrasound(IVUS)images.In the present study,we evaluate the diagnostic performance of UFR in patients with intermediate left main(LM)stenosis.METHODS This is a prospective,single center study enrolling consecutive patients with presence of intermediated LM lesions(diameter stenosis of 30%-80%by visual estimation)underwent IVUS and FFR measurement.An independent core laboratory assessed offline UFR and IVUS-derived minimal lumen area(MLA)in a blinded fashion.RESULTS Both UFR and FFR were successfully achieved in 41 LM patients(mean age,62.0±9.9 years,46.3%diabetes).An acceptable correlation between UFR and FFR was identified(r=0.688,P<0.0001),with an absolute numerical difference of 0.03(standard difference:0.01).The area under the curve(AUC)in diagnosis of physiologically significant coronary stenosis for UFR was 0.94(95%CI:0.87-1.01),which was significantly higher than angiographic identified stenosis>50%(AUC=0.66,P<0.001)and numerically higher than IVUS-derived MLA(AUC=0.82;P=0.09).Patient level diagnostic accuracy,sensitivity and specificity for UFR to identify FFR≤0.80 was 82.9%(95%CI:70.2-95.7),93.1%(95%CI:82.2-100.0),58.3%(95%CI:26.3-90.4),respectively.CONCLUSION In patients with intermediate LM diseases,UFR was proved to be associated with acceptable correlation and high accuracy with pressure wire-based FFR as standard reference.The present study supports the use of UFR for functional evaluation of intermediate LM stenosis.
文摘Objectives To evaluate the feasibility and safety of a second generation robotic percutaneous coronary intervention(R-PCI)system in China.Background Robotic PCI has been shown to be an effective method for conducting coronary interventions.It has further benefits of more accurate lesion measurement,improved stent deployment,reduced incidence of geographic miss and reduction of operator radiation exposure.Methods This single center evaluation enrolled 10 consecutive patients who had been selected for PCI.Clinical success was defined as residual stenosis<30%and no in-hospital major adverse cardiovascular events.Learning curve effect was assessed by comparing efficiency metrics of early vs.later cases.Results Eleven lesions were treated all successfully without manual interruption or MACE events.Most lesions(63%)were ACC/AHA class B2 and C.Mean procedure time was 57.7±26.4 min,however two procedures were part of live demonstrations.Excluding the two live cases,the mean procedure time was 51.8±23.7 min.Procedural efficiency tended to improve from early cases to later cases based on PCI time(48.3±32.9 vs.25.5±13.0 min,P=0.27),fluoroscopy time(20.3±8.2 vs.12.5±4.6 min,P=0.16),contrast volume(145.0±28.9 vs.102.5±17.1 mL,P=0.05)and Air Kerma dose(1932±978 vs.1007±70 mGy,P=0.31).Conclusions Second generation robotic PCI was safe,effective and there were trends toward improvements in procedural efficiency during this early experience in China.
文摘Optoelectronic devices on silicon substrates are essential not only to the optoelectronic integrated circuit but also to low-cost lasers,large-area detectors,and so forth.Although heterogeneous integration of III-V semiconductors on Si has been welldeveloped,the thermal dissipation issue and the complicated fabrication process still hinders the development of these devices.The monolithic growth of III-V materials on Si has also been demonstrated by applying complicated buffer layers or interlayers.On the other hand,the growth of lattice-matched B-doped group-III-V materials is an attractive area of research.However,due to the difficulty in growth,the development is still relatively slow.Herein,we present a comprehensive review of the recent achievements in this field.We summarize and discuss the conditions and mechanisms involved in growing B-doped group-III-V materials.The unique surface morphology,crystallinity,and optical properties of the epitaxy correlating with their growth conditions are discussed,along with their respective optoelectronic applications.Finally,we detail the obstacles and challenges to exploit the potential for such practical applications fully.
基金supported by the National Key Researchand Development Program of China (2016YFC130130 [Subtopic:2016YFC1301301]).
文摘BACKGROUND: We aim to investigate effects of metabolic syndrome on onset age and long-termoutcomes in patients with acute coronary syndrome (ACS).METHODS: Patients with ACS (n=6,431) who underwent percutaneous coronary interventionfrom January to December 2013 were enrolled. After excluding patients with previous coronary arterydisease, 1,558 patients were diagnosed with early-onset ACS (men aged ≤50 years;women aged≤60 years) and 3,044 patients with late-onset ACS. Baseline characteristics and five-year clinicaloutcomes were measured.RESULTS: Body mass index, triglyceride, low-density lipoprotein cholesterol, and uric acidconcentrations were significantly higher, while the high-density lipoprotein cholesterol (HDL-C)concentration was lower in the early-onset ACS group (P<0.001). Multivariate logistic regression revealedobesity (odds ratio [OR] 1.590, 95% confi dence interval [CI] 1.345–1.881), hypertriglyceridemia (OR 1.403,95% CI 1.185–1.660), and low HDL-C (OR 1.464, 95% CI 1.231–1.742) as independent risk factorsfor early-onset ACS (all P<0.001). The fi ve-year follow-up showed that the incidences of all cause death(1.5% vs. 3.8%, P<0.001), cardiac death (1.1% vs. 2.0%, P=0.023), and recurrent stroke (2.2% vs. 4.2%,P<0.001) were lower, while bleeding events were more frequent in the early-onset ACS group. A subgroupanalysis showed higher incidences of recurrent myocardial infarction (MI) and revascularization in patientswith early-onset ACS and metabolic syndrome.CONCLUSIONS: Obesity, hypertriglyceridemia, and lower HDL-C level are independent riskfactors for early-onset ACS, recurrent MI, and revascularization. The control of metabolic syndromemay reduce the incidence of early-onset ACS and improve the long-term prognosis.
基金supported by the National Natural Science Foundation of China (Grant Nos. 81001209 and 81172578)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (Grant No. 81321002)
文摘The present study evaluated the expression of key molecules and the status of DNA in both oral squamous cell carcinoma（OSCC） and adjacent tissues to establish a molecular surgical boundary and provide a cancer progression model. Biopsy samples from 50 OSCC patients were divided into T（cancer）, P1（0–0.5 cm）, P2（0.5–1 cm）, P3（1–1.5 cm） and P4（1.5–2 cm） groups based on the distances from the visible boundary of the primary focus. Twenty samples of normal mucosa were used as controls. We used immunohistochemical staining and flow cytometry to evaluate p53, p21CIP1/WAF1, e IF4 E and Ki-67 expression and to determine DNA status, respectively. Sub-mucosal invasion was present in the P1 and P2 groups as determined by haematoxylin and eosin staining.Mutant p53 expression decreased gradually from cancerous to normal mucosae, whereas p21CIP1/WAF1 expression displayed an opposite trend. e IF4 E expression decreased from cancerous to normal mucosae. Ki-67 expression, the heteroploidy ratio, S-phase fraction and proliferative index decreased gradually with the distance from the tumour centre. Based on these results, we suggest that the resection boundary in OSCC surgery should be beyond 2 cm from the tumour. Additionally, the adjacent tissues of the primary focus could be used as a model for assessing cancer progression.
文摘A novel amperometric biosensor for the detection of hydrogen peroxide is described. The biosensor was constructed by electrodepositing HRP/PPy membrane on the surface of ferrocenecarboxylic acid mediated sol-gel derived composite carbon electrode. The biosensor gives response to hydrogen peroxide in a few seconds with detection limit of 5×10-7 mol·L-1 （based on signal : noise=3）. Linear range is up to 0.2 mmol·L-1.
基金supported by the National Natural Science Foundation of China(Grant Nos.52090020,91963203,U20A20238,51772260,52073245,and 51722209)the National Key R&D Program of China(Grant Nos.2018YFA0703400 and 2018YFA0305900)+1 种基金the Natural Science Foundation for Distinguished Young Scholars of Hebei Province of China(Grant No.E2018203349)the Talent Research Project in Hebei Province(Grant No.2020HBQZYC003)。
文摘Both boron nitride(BN)and carbon(C)have sp,sp^(2)and sp^(3)hybridization modes,thus resulting in a variety of BN and C polymorphs with similar structures,such as hexagonal BN(hBN)and graphite,cubic BN(cBN)and diamond.Here,five types of BN polymorph structures are proposed theoretically,inspired by the graphite-diamond hybrid structures discovered in a recent experiment.These BN polymorphs with graphite-diamond hybrid structures possess excellent mechanical properties with combined high hardness and high ductility,and also exhibit various electronic properties such as semi-conductivity,semi-metallicity,and even one-and two-dimensional conductivity,differing from known insulators hBN and cBN.The simulated diffraction patterns of these BN hybrid structures could account for the unsolved diffraction patterns of intermediate products composed of so-called“compressed hBN”and diamond-like BN,caused by phase transitions in previous experiments.Thus,this work provides a theoretical basis for the presence of these types of hybrid materials during phase transitions between graphite-like and diamond-like BN polymorphs.
