Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lak...Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lake,a subtropical plateau lake in Yunnan Province,SW China,has long experienced the effects of eutrophication and cyanobacterial blooms.To mitigate the eutrophication of Dianchi Lake,various efforts have been implemented since 2000,including reducing nutrient inputs,reestablishing aquatic macrophytes in lakeside zones,manipulating fishes and so on.However,little is known about the changes in its ecosystem structure and function after long-term efforts of eutrophication management in the lake.Therefore,this study on such changes was conducted by comparing the field data-based Ecopath models between 2009 and 2019,a decade marked by a rapid implementation of eutrophication management policies.Results show that both top-down and bottom-up processes have influenced the ecosystem structure and function.First,over this decade,nutrient reduction significantly reduced phytoplankton biomass by 49.4%.Nutrient recycling and path length in food web began to decrease,as indicated by the decrease of Finn's cycling index and Finn's mean path length.Secondly,fishing management strategy has greatly changed the composition of fish assemblage,which was dominated by the small zooplantivorous fishes with ecological niche overlapping with shrimps.In general,the stability of the ecosystem has been decreasing,due to the dramatic decrease in zooplankton biomass(83.67%)and hence a collapse of the microbial loop in the food web.Therefore,we strongly advocate the persistent efforts to mitigate the risk of recurrent cyanobacteria blooms in Dianchi Lake,necessitating stricter regulation of nutrient levels and implementing effective fish population management techniques.展开更多
In this paper,we proposed a compact,lightweight flapping actuation mechanism and a flight control mechanism for a twin-winged,tailless,hover-capable flapping robot named HiFly-Hummingbird,which has a total mass of 14....In this paper,we proposed a compact,lightweight flapping actuation mechanism and a flight control mechanism for a twin-winged,tailless,hover-capable flapping robot named HiFly-Hummingbird,which has a total mass of 14.4 g and a wingspan of 18.8 cm.A four-bar linkage and gears set were adopted to convert the rotation motion of DC motor into flapping oscillation and amplify the flapping amplitude.As well as,a parallel coupled flight control mechanism was designed to implement the aerodynamic moments generation strategies.The proposed flapping actuation mechanism,with a mass of 2.95 g,has been validated to achieve a 168°amplitude at a frequency of 26 Hz with an asymmetrical stroke deviation of 3.5%,operating at a power consumption of 4.05 W.The parallel coupled control mechanism weights 2.14 g(including three servos).Benefit from the nonlinen inverse kinematics model of the parallel coupled control mechanism,the proposed control mechanism exhibits a roll motion range of±10°with an accuracy error of 0.8°and a pitch motion range of±12°with an accuracy error of 0.6°.The proposed mechanical systems are beneficial to lightweight design,manufacture and assemble under stringent size,weight and power(SWaP)constraints of flapping wing micro air vehicles(FW-MAVs),and possess favorable efficiency and accuracy.Relying on the hardware control circuit and feed-back attitude control algorithm,the robot hummingbird successfully achieved untethered lifting off and reached a maximum flight altitude of 4 m in several flight tests,demonstrating that the proposed mechanical designs of the flapping robot platform effectively enhances the miniaturization and light-weighting of the hummingbird-like FW-MAVs under the conditions of meeting the propulsion and control requirements for lifting off.展开更多
Over the past decade,there has been increasing attention on the interaction between microbiota and bile acid metabolism.Bile acids are not only involved in the metabolism of nutrients,but are also important in signal ...Over the past decade,there has been increasing attention on the interaction between microbiota and bile acid metabolism.Bile acids are not only involved in the metabolism of nutrients,but are also important in signal transduction for the regulation of host physiological activities.Microbial-regulated bile acid metabolism has been proven to affect many diseases,but there have not been many studies of disease regulation by microbial receptor signaling pathways.This review considers findings of recent research on the core roles of farnesoid X receptor(FXR),G protein-coupled bile acid receptor(TGR5),and vitamin D receptor(VDR)signaling pathways in microbial–host interactions in health and disease.Studying the relationship between these pathways can help us understand the pathogenesis of human diseases,and lead to new solutions for their treatments.展开更多
The speed of an Electro-Hydrostatic Actuator(EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in a...The speed of an Electro-Hydrostatic Actuator(EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in aircraft EHA systems. In order to reduce churning losses at high speeds, more attention should be given to the design of an insert. In this paper, the effect of an insert with different design parameters on churning losses is investigated through Computational Fluid Dynamics(CFD) simulation and experiments by calculating the difference between churning losses torques of the test pump with and without the insert based on a high-speed churning losses test rig.Analytical results show that the gap between the insert and the cylinder is critical for churning losses reduction. It is found that the churning losses of the test pump can be reduced with a decreasing gap between the cylinder block and the insert at high speeds. This is because the insert can decrease the turbulence occurrence at high speeds. The results can be used for flow field analysis and optimization of the high-speed EHA pump and provide a new method for improving efficiency of high-speed EHA pumps.展开更多
High-speed axial piston pumps are hydraulic power supplies for electro-hydrostatic actuators(EHAs). The efficiency of a pump directly affects the operating performance of an EHA, and an understanding of the physical p...High-speed axial piston pumps are hydraulic power supplies for electro-hydrostatic actuators(EHAs). The efficiency of a pump directly affects the operating performance of an EHA, and an understanding of the physical phenomena occurring in the cylinder/valve plate interface is essential to investigate energy dissipation. The effects of the splined shaft bending rigidity on the cylinder tilt behaviour in an EHA pump need to be considered, because the deflection and radial expansion of a steel shaft rotating at a high speed cannot be ignored. This paper proposes a new mathematical model to predict the cylinder tilt behaviour by establishing a quantitative relationship between the splined shaft deflection, the cylinder tilt angle, and the tilt azimuth angle. The moments exerted by the splined shaft are included in the equilibrium equation of the cylinder. The effects of solid and hollow splined shafts equipped in an EHA pump prototype are compared at variable speeds of 5000–10,000 r/min. With a weight saving of 29.7%, the hollow shaft is experimentally found to have almost no influence on the volumetric efficiency, but to reduce the mechanical efficiency by 0.6–2.4%. The results agree with the trivial differences of the simulated central gap heights of the interface between the two shafts and the enlargement of the simulated tilt angles by the hollow shaft. The findings could guide designs of the cylinder/valve plate interface and the splined shaft to improve both the efficiency and power density of an EHA pump.展开更多
Lymphatic metastasis(LM)emerges as an independent prognostic marker for hypopharyngeal squamous cell carcinoma(HSPSCC),chiefly contributing to treatment inefficacy.This study aimed to scrutinize the prognostic relevan...Lymphatic metastasis(LM)emerges as an independent prognostic marker for hypopharyngeal squamous cell carcinoma(HSPSCC),chiefly contributing to treatment inefficacy.This study aimed to scrutinize the prognostic relevance of HSP90AA1 and its potential regulatory mechanism of concerning LM in HPSCC.Methods:In a preceding investigation,HSP90AA1,a differential gene,was discovered through transcriptome sequencing of HPSCC tissues,considering both the presence and absence of LM.Validation of HSP90AA1 expression was accomplished via qRT-PCR,western-blotting(WB),and immunohistochemistry(IHC),while its prognostic significance was assessed employing Kaplan–Meier survival analysis(KMSA),log-rank test(LR),and Cox’s regression analysis(CRA).Bioinformatics techniques facilitated the prediction and analysis of its plausible mechanisms in LM,further substantiated by in vitro and in vivo experiments utilizing FaDu cell lines.Results:HSP90AA1 is substantially upregulated in HPSCC with LM and is identified as an independent prognostic risk determinant.The down-regulation of HSP90AA1 can achieve inhibition of tumor cell proliferation,migration and invasion.Both in vivo experiments and Bioinformatics exploration hint at promoting LM by Epithelial-mesenchymal transition(EMT),regulated by HSP90AA1.Conclusions:HSP90AA1,by controlling EMT,can foster LM in HPSCC.This finding sets the foundation for delving into new therapeutic targets for HPSCC.展开更多
Objective:To observe the effect of the cyclophosphamide(CTX) on systemic lupus erythematosus mice by fluorescent quantitative polymerase chain reaction.Methods:(BALB/c C57BL/J6) Fl hybrid mice were used as recipients ...Objective:To observe the effect of the cyclophosphamide(CTX) on systemic lupus erythematosus mice by fluorescent quantitative polymerase chain reaction.Methods:(BALB/c C57BL/J6) Fl hybrid mice were used as recipients of donor lymphocytes which were injected intravenously.Mice were randomly divided into control group and treatment group,serum autoantibody and urinary protein were measured,renal pathological changes and the situation of fungal infection were observed.Results:The reduced urinary protein,ameliorated renal lesions were found in the CTX-treated mice.Candida albicans and Aspergillus Jlants were detected respectively in respiratory tract and gastrointestinal tract.Conclusions:CTX can alleviate lupus nephritis and the fluorescent quantitative PCR is a rapid and sensitive method for the detection of fungal infection.展开更多
BACKGROUND The incidence of prostate cancer(PCa)is on the rise in China.The risk level of patients with PCa is associated with disease-free survival rate at 10 years after radical prostatectomy.Predicting prognosis in...BACKGROUND The incidence of prostate cancer(PCa)is on the rise in China.The risk level of patients with PCa is associated with disease-free survival rate at 10 years after radical prostatectomy.Predicting prognosis in advance according to the degree of risk can provide a reference for patients,especially treatment options and postoperative adjuvant treatment measures for high-risk/extremely high-risk patients.AIM To explore the predictive value of the prognostic nutritional index(PNI)for biological recurrence in Chinese patients with high/extremely high-risk PCa after radical prostatectomy.METHODS The biochemical test results and clinical data of 193 patients who underwent radical prostatectomy for the first time from January 2015 to December 2020 were retrospectively collected.The PNI value of peripheral blood within 1 wk before surgery was calculated,and during the follow-up period,prostate-specific antigen≥0.2 ng/mL was considered to have biological recurrence.The receiver operating characteristic(ROC)curve was used to calculate the optimal critical value and area under the curve(AUC)of the patients.According to the critical value,the progression-free survival of the high PNI group and low PNI group was compared.The independent influencing factors of the patients’prognosis were obtained by the Cox proportional hazards regression model.RESULTS The non-biological recurrence rates at 1,3,and 5 years were 92.02%,84.05%,and 74.85%,respectively.The optimal critical value for PNI to predict biological recurrence was 46.23,and the AUC was 0.789(95%confidence interval:0.651-0.860;P<0.001).The sensitivity and specificity were 82.93%and 62.30%,respectively.In accordance with the optimal critical value of the ROC curve(46.23),193 patients were further divided into a high PNI group(PNI≤46.23,n=108)and low PNI group(PNI>46.23,n=85).The incidence of postoperative complications in the high PNI group was lower than that in the low PNI group(21.18%vs 38.96%).Kaplan-Meier survival analysis showed that the overall survival rate at 5 years in the low PNI group was 87.96%(13/108),which was lower than that in the high PNI group(61.18%,33/85;P<0.05).Low PNI[hazard ratio(HR)=1.74;P=0.003]and positive incisal margin status(HR=2.14;P=0.001)were independent predictors of biological recurrence in patients with high/extremely high-risk PCa.CONCLUSION The PNI has predictive value for the prognosis of patients with high/extremely high-risk PCa,and is an independent prognostic factor.Patients with low PNI value have a shorter time of nonbiological recurrence after prostatectomy.It is expected that the combined prediction of other clinicopathological data will further improve the accuracy and guide postoperative adjuvant therapy to improve the quality of prognosis.展开更多
Nitrous oxide（N_2O） is a potent greenhouse gas that can be emitted during biological nitrogen removal. N_2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600 m L/min sequenc...Nitrous oxide（N_2O） is a potent greenhouse gas that can be emitted during biological nitrogen removal. N_2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600 m L/min sequencing batch reactor（SBRL） and 1200 m L/min（SBRH）.The nitrogen removal percentage was 89% in SBRLand 71% in SBRH, respectively. N_2O emission mainly occurred during the aerobic phase, and the N_2O emission factor was 10.1%in SBRLand 2.3% in SBRH, respectively. In all batch experiments, the N_2O emission potential was high in SBRLcompared with SBRH. In SBRL, with increasing aeration rates, the N_2O emission factor decreased during nitrification, while it increased during denitrification and simultaneous nitrification and denitrification（SND）. By contrast, in SBRHthe N_2O emission factor during nitrification, denitrification and SND was relatively low and changed little with increasing aeration rates. The microbial competition affected the N_2O emission during biological nitrogen removal.展开更多
BACKGROUND Gastric cancer(GC)has high morbidity and mortality.Moreover,because GC has no typical symptoms in the early stages,most cases are already in the advanced stages by the time the symptoms appear,thus resultin...BACKGROUND Gastric cancer(GC)has high morbidity and mortality.Moreover,because GC has no typical symptoms in the early stages,most cases are already in the advanced stages by the time the symptoms appear,thus resulting in poor prognosis and a low survival rate.Endoscopic submucosal dissection(ESD)can realize the early detection and diagnosis of GC and become the main surgical method for early GC.However,ESD has a steep learning curve and high technical skill requirements for endoscopists,which is not conducive to its widespread implementation and advancement.Therefore,a series of auxiliary techniques have been derived.AIM To evaluate the safety and efficacy of magnetic anchor technique(MAT)-assisted ESD in early GC.METHODS This was an ex vivo animal experiment.The experimental models were the isolated stomachs of pigs,which were divided into two groups,namely the study group(n=6)with MAT-assisted ESD and the control group(n=6)with traditional ESD.Comparing the total surgical time,incidence of surgical complications,complete mucosal resection rate,specimen size,and the scores of endoscopist’s satisfaction with the procedure reflected their feelings about convenience during the surgical procedure between the two groups.The magnetic anchor device for auxiliary ESD in the study group comprised three parts,an anchor magnet(AM),a target magnet(TM),and a soft tissue clip.Under gastroscopic guidance,the soft tissue clip and the TM were delivered to the pre-marked mucosal lesion through the gastroscopic operating hole.The soft tissue clip and the TM were connected by a thin wire through the TM tail structure.The soft tissue clip was released by manipulating the operating handle of the soft tissue clip in a way that the soft tissue clip and the TM were fixed to the lesion mucosa.In vitro,ESD is aided by maneuvering the AM such that the mucosal dissection surface is exposed.RESULTS The total surgical time was shorter in the study group than in the control group(26.57±0.19 vs 29.97±0.28,P<0.001),and the scores of endoscopist’s satisfaction with the procedure were higher in the study group than in the control group(9.53±0.10 vs 8.00±0.22,P<0.001).During the operation in the study group,there was no detachment of the soft tissue clip and TM and no mucosal tearing.The magnetic force between the AM and TM provided good mucosal exposure and sufficient tissue tension for ESD.The mucosal lesion was completely peeled off,and the operation was successful.There were no significant differences in the incidence of surgical complications(100%vs 83.3%),complete mucosal resection rate(100%vs 66.7%,P=0.439),and specimen size(2.44±0.04 cm vs 2.49±0.02,P=0.328)between the two groups.CONCLUSION MAT-ESD is safe and effective for early GC.It provides a preliminary basis for subsequent internal animal experiments and clinical research.展开更多
The double perovskites Sr_(2)SmNbO_(6),Sr_(2)CoNbO_(6)and Ba2CoNbO_(6)were investigated with first principles computations based on the density functional theory and plus U treatment.Firstly,different calculation meth...The double perovskites Sr_(2)SmNbO_(6),Sr_(2)CoNbO_(6)and Ba2CoNbO_(6)were investigated with first principles computations based on the density functional theory and plus U treatment.Firstly,different calculation methods were examined in order to quantitatively approach the exact band gap.It was found that neither the strongly constrained and appropriately normed(SCAN)semilocal density functional nor the hybrid HSE06 functional can well address the semiconducting nature of the investigated double perovskites,while PBEþU or SCANþU with appropriately determining the U value can have good performance,which paves the way for future studies of double perovskites.With self-consistently calculated electron correlation strength,the magnetic states and the band gaps of the Sr_(2)CoNbO_(6)and Ba_(2)CoNbO_(6)were more precisely determined.The electronic,optical and thermoelectric properties were then investigated and discussed for possible applications.展开更多
TiO2 films have been widely applied in photo- voltaic conversion techniques. TiO2 nanotube arrays （TiO2 NAs） can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi2S3 and PbS nanoparticl...TiO2 films have been widely applied in photo- voltaic conversion techniques. TiO2 nanotube arrays （TiO2 NAs） can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi2S3 and PbS nanoparticles （NPs） were firstly co-sensitized on TiOa NAs （denoted as PbS/Bi2S3（n）/TiO2 NAs） by a two-step process containing hydrothermal and sonication-assisted SILAR method. When the concentration of Bi3＋ is 5 mmol/L, the best photoelectrical performance was obtained under simulated solar irradiation. The short-circuit photocurrent （Jsc） and photoconversion efficiency （η） of PbS/Bi2S3（5）/TiO2 NAs electrode were 4.70 mA/cm and 1.13 %, respectively.展开更多
Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）....Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）. There have been comprehensive and intensive studies on the applications, the fundamental lattice dynamic and electronic properties, etc., of A15 superconductors. Various reviews on the preparations, structures, and properties have already been written in the last few years. Nevertheless, on account of the large amount of existing facts and views, a coherent view on the relations between the structures and properties has not appeared to unify the facts. This article sketches a multi-scale point of view on the relations between the multi- scale structures and the corresponding properties.展开更多
YBa2Cu3O7-d （YBCO）-coated conductors havewide-ranging potential in large-scale applications such assuperconducting maglev trains and superconducting electriccables, but low current carrying capability restrains thep...YBa2Cu3O7-d （YBCO）-coated conductors havewide-ranging potential in large-scale applications such assuperconducting maglev trains and superconducting electriccables, but low current carrying capability restrains thepractical application of YBCO-coated conductors at hightemperatures and high magnetic fields. It is crucial todevelop YBCO-coated conductors with high critical currentdensity. In this paper, epitaxial, dense, smooth, andcrack-free Fe-doped YBCO films were prepared on aLaAlO3 single crystal substrate via a fluorine-free polymerassistedmetal organic deposition method. The effects ofthe dilute Fe doping on microstructure and superconductingcharacter of YBCO films were investigated. The criticaltemperature for superconducting of the Fe-dopedYBCO films decreases slightly. However, the in-fieldcritical current density of YBCO films improves with diluteFe doping of amounts less than x = 0.005, compared to thepure YBCO film. Therefore, the current carrying capabilityof YBCO film can improve by doping with appropriateamounts of Fe. This means that dilute Fe doping in YBCOfilms may be a feasible way to prepare high-performancecoated conductors.展开更多
BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study repo...BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study reported a rare TC with multiple bone metastases.A 77-year-old man presented with a 2-month history of lower back pain and weight loss of 5 kg.Magnetic resonance imaging scans revealed damage to the lumbar spine,sacrocaudal vertebrae and iliac crest,suggesting bone metastasis;computed tomography(CT)scan of the thorax showed a calcified anterior mediastinal mass;positron emission tomography-CT demonstrated multiple abnormal bone signals;and laboratory work-up showed no endocrine abnormalities.Fine-needle aspiration biopsy revealed predominantly single small,round to oval cells with scant cytoplasm and some loose clusters,suggesting endocrine manifestations.The pathological diagnosis was atypical carcinoid,which tend to originate from the thymus and was classified as intermediate-highly invasive.The patient underwent anlotinib-targeted therapy.Anlotinib(12 mg)was administered daily for 2 wk,after which the patient was allowed to rest for 21 d.Follow-up CT after one year demonstrated that the tumor had shrunk by approximately 29%after therapy.Treatment has a long stable disease benefit of more than 2.5 years.CONCLUSION These findings demonstrated that anlotinib is a promising treatment regimen for patients with TC and multiple bone metastases.展开更多
基金Supported by the Yunnan-Kunming Major Science and Technology Project(No.202202AH210006)the Dianchi Lake Ecosystem Observation and Research Station of Yunnan Province Project(No.202305AM340008)+2 种基金the Yunnan-Kunming Liu Yongding Academician Workstation Funds(No.YSZJGZZ-2020018)the Yunnan Science and Technology Commission(Nos.202401AS070119,202103AC100001)the National Natural Science Foundation of China(No.52379081)。
文摘Large and shallow lakes are widely influenced by multiple anthropogenic stressors,including eutrophication.Normally,diverse strategies of eutrophication management are needed to restore the lake ecosystems.Dianchi Lake,a subtropical plateau lake in Yunnan Province,SW China,has long experienced the effects of eutrophication and cyanobacterial blooms.To mitigate the eutrophication of Dianchi Lake,various efforts have been implemented since 2000,including reducing nutrient inputs,reestablishing aquatic macrophytes in lakeside zones,manipulating fishes and so on.However,little is known about the changes in its ecosystem structure and function after long-term efforts of eutrophication management in the lake.Therefore,this study on such changes was conducted by comparing the field data-based Ecopath models between 2009 and 2019,a decade marked by a rapid implementation of eutrophication management policies.Results show that both top-down and bottom-up processes have influenced the ecosystem structure and function.First,over this decade,nutrient reduction significantly reduced phytoplankton biomass by 49.4%.Nutrient recycling and path length in food web began to decrease,as indicated by the decrease of Finn's cycling index and Finn's mean path length.Secondly,fishing management strategy has greatly changed the composition of fish assemblage,which was dominated by the small zooplantivorous fishes with ecological niche overlapping with shrimps.In general,the stability of the ecosystem has been decreasing,due to the dramatic decrease in zooplankton biomass(83.67%)and hence a collapse of the microbial loop in the food web.Therefore,we strongly advocate the persistent efforts to mitigate the risk of recurrent cyanobacteria blooms in Dianchi Lake,necessitating stricter regulation of nutrient levels and implementing effective fish population management techniques.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences under Grant XDA2202050partially supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant 2013213.
文摘In this paper,we proposed a compact,lightweight flapping actuation mechanism and a flight control mechanism for a twin-winged,tailless,hover-capable flapping robot named HiFly-Hummingbird,which has a total mass of 14.4 g and a wingspan of 18.8 cm.A four-bar linkage and gears set were adopted to convert the rotation motion of DC motor into flapping oscillation and amplify the flapping amplitude.As well as,a parallel coupled flight control mechanism was designed to implement the aerodynamic moments generation strategies.The proposed flapping actuation mechanism,with a mass of 2.95 g,has been validated to achieve a 168°amplitude at a frequency of 26 Hz with an asymmetrical stroke deviation of 3.5%,operating at a power consumption of 4.05 W.The parallel coupled control mechanism weights 2.14 g(including three servos).Benefit from the nonlinen inverse kinematics model of the parallel coupled control mechanism,the proposed control mechanism exhibits a roll motion range of±10°with an accuracy error of 0.8°and a pitch motion range of±12°with an accuracy error of 0.6°.The proposed mechanical systems are beneficial to lightweight design,manufacture and assemble under stringent size,weight and power(SWaP)constraints of flapping wing micro air vehicles(FW-MAVs),and possess favorable efficiency and accuracy.Relying on the hardware control circuit and feed-back attitude control algorithm,the robot hummingbird successfully achieved untethered lifting off and reached a maximum flight altitude of 4 m in several flight tests,demonstrating that the proposed mechanical designs of the flapping robot platform effectively enhances the miniaturization and light-weighting of the hummingbird-like FW-MAVs under the conditions of meeting the propulsion and control requirements for lifting off.
基金Project supported by the Fundamental Research Funds for the Central Universities(No.2015FZA4001)the Youth Funds of the State Key Laboratory of Fluid Power Transmission and Control(No.SKLo FP_QN_1502),China
基金Project supported by the National Key Research and Development Program of China(No.2016YFA0501602)the National Natural Science Foundation of China(Nos.61801108 and 81801478)
文摘Over the past decade,there has been increasing attention on the interaction between microbiota and bile acid metabolism.Bile acids are not only involved in the metabolism of nutrients,but are also important in signal transduction for the regulation of host physiological activities.Microbial-regulated bile acid metabolism has been proven to affect many diseases,but there have not been many studies of disease regulation by microbial receptor signaling pathways.This review considers findings of recent research on the core roles of farnesoid X receptor(FXR),G protein-coupled bile acid receptor(TGR5),and vitamin D receptor(VDR)signaling pathways in microbial–host interactions in health and disease.Studying the relationship between these pathways can help us understand the pathogenesis of human diseases,and lead to new solutions for their treatments.
基金financial supports from the National Basic Research Program of China(973 Program)(No.2014CB046403)the National Natural Science Foundation of China(No.1737110)
文摘The speed of an Electro-Hydrostatic Actuator(EHA) pump can recently reach 20000 r/min, and its churning losses increase obviously with an increasing speed, which results in low efficiency and thus increasing heat in aircraft EHA systems. In order to reduce churning losses at high speeds, more attention should be given to the design of an insert. In this paper, the effect of an insert with different design parameters on churning losses is investigated through Computational Fluid Dynamics(CFD) simulation and experiments by calculating the difference between churning losses torques of the test pump with and without the insert based on a high-speed churning losses test rig.Analytical results show that the gap between the insert and the cylinder is critical for churning losses reduction. It is found that the churning losses of the test pump can be reduced with a decreasing gap between the cylinder block and the insert at high speeds. This is because the insert can decrease the turbulence occurrence at high speeds. The results can be used for flow field analysis and optimization of the high-speed EHA pump and provide a new method for improving efficiency of high-speed EHA pumps.
基金supported by the NSFC-Zhejiang Joint Fund for the Integration of Industrialization and Informatization(No.U1509204),Chinathe National Natural Science Foundation of China(Nos.91748210 and 51375431)the Strengthening Industrial Base Project(No.TC150B5C0-29),China
基金the financial supports received from the National Basic Research Program of China (973 Program) (No. 2014CB046403)the National Natural Science Foundation of China (Nos. U1509204 and 51605425)
文摘High-speed axial piston pumps are hydraulic power supplies for electro-hydrostatic actuators(EHAs). The efficiency of a pump directly affects the operating performance of an EHA, and an understanding of the physical phenomena occurring in the cylinder/valve plate interface is essential to investigate energy dissipation. The effects of the splined shaft bending rigidity on the cylinder tilt behaviour in an EHA pump need to be considered, because the deflection and radial expansion of a steel shaft rotating at a high speed cannot be ignored. This paper proposes a new mathematical model to predict the cylinder tilt behaviour by establishing a quantitative relationship between the splined shaft deflection, the cylinder tilt angle, and the tilt azimuth angle. The moments exerted by the splined shaft are included in the equilibrium equation of the cylinder. The effects of solid and hollow splined shafts equipped in an EHA pump prototype are compared at variable speeds of 5000–10,000 r/min. With a weight saving of 29.7%, the hollow shaft is experimentally found to have almost no influence on the volumetric efficiency, but to reduce the mechanical efficiency by 0.6–2.4%. The results agree with the trivial differences of the simulated central gap heights of the interface between the two shafts and the enlargement of the simulated tilt angles by the hollow shaft. The findings could guide designs of the cylinder/valve plate interface and the splined shaft to improve both the efficiency and power density of an EHA pump.
基金supported by the National Natural Science Foundation of China(Grant No.82173303)Natural Science Foundation of Chongqing,China(Grant No.cstc2021ycjh-bgzxm0149).
文摘Lymphatic metastasis(LM)emerges as an independent prognostic marker for hypopharyngeal squamous cell carcinoma(HSPSCC),chiefly contributing to treatment inefficacy.This study aimed to scrutinize the prognostic relevance of HSP90AA1 and its potential regulatory mechanism of concerning LM in HPSCC.Methods:In a preceding investigation,HSP90AA1,a differential gene,was discovered through transcriptome sequencing of HPSCC tissues,considering both the presence and absence of LM.Validation of HSP90AA1 expression was accomplished via qRT-PCR,western-blotting(WB),and immunohistochemistry(IHC),while its prognostic significance was assessed employing Kaplan–Meier survival analysis(KMSA),log-rank test(LR),and Cox’s regression analysis(CRA).Bioinformatics techniques facilitated the prediction and analysis of its plausible mechanisms in LM,further substantiated by in vitro and in vivo experiments utilizing FaDu cell lines.Results:HSP90AA1 is substantially upregulated in HPSCC with LM and is identified as an independent prognostic risk determinant.The down-regulation of HSP90AA1 can achieve inhibition of tumor cell proliferation,migration and invasion.Both in vivo experiments and Bioinformatics exploration hint at promoting LM by Epithelial-mesenchymal transition(EMT),regulated by HSP90AA1.Conclusions:HSP90AA1,by controlling EMT,can foster LM in HPSCC.This finding sets the foundation for delving into new therapeutic targets for HPSCC.
基金supported by Department of Science&Technology of Shandong Province.Topic No.2011YD18044
文摘Objective:To observe the effect of the cyclophosphamide(CTX) on systemic lupus erythematosus mice by fluorescent quantitative polymerase chain reaction.Methods:(BALB/c C57BL/J6) Fl hybrid mice were used as recipients of donor lymphocytes which were injected intravenously.Mice were randomly divided into control group and treatment group,serum autoantibody and urinary protein were measured,renal pathological changes and the situation of fungal infection were observed.Results:The reduced urinary protein,ameliorated renal lesions were found in the CTX-treated mice.Candida albicans and Aspergillus Jlants were detected respectively in respiratory tract and gastrointestinal tract.Conclusions:CTX can alleviate lupus nephritis and the fluorescent quantitative PCR is a rapid and sensitive method for the detection of fungal infection.
文摘BACKGROUND The incidence of prostate cancer(PCa)is on the rise in China.The risk level of patients with PCa is associated with disease-free survival rate at 10 years after radical prostatectomy.Predicting prognosis in advance according to the degree of risk can provide a reference for patients,especially treatment options and postoperative adjuvant treatment measures for high-risk/extremely high-risk patients.AIM To explore the predictive value of the prognostic nutritional index(PNI)for biological recurrence in Chinese patients with high/extremely high-risk PCa after radical prostatectomy.METHODS The biochemical test results and clinical data of 193 patients who underwent radical prostatectomy for the first time from January 2015 to December 2020 were retrospectively collected.The PNI value of peripheral blood within 1 wk before surgery was calculated,and during the follow-up period,prostate-specific antigen≥0.2 ng/mL was considered to have biological recurrence.The receiver operating characteristic(ROC)curve was used to calculate the optimal critical value and area under the curve(AUC)of the patients.According to the critical value,the progression-free survival of the high PNI group and low PNI group was compared.The independent influencing factors of the patients’prognosis were obtained by the Cox proportional hazards regression model.RESULTS The non-biological recurrence rates at 1,3,and 5 years were 92.02%,84.05%,and 74.85%,respectively.The optimal critical value for PNI to predict biological recurrence was 46.23,and the AUC was 0.789(95%confidence interval:0.651-0.860;P<0.001).The sensitivity and specificity were 82.93%and 62.30%,respectively.In accordance with the optimal critical value of the ROC curve(46.23),193 patients were further divided into a high PNI group(PNI≤46.23,n=108)and low PNI group(PNI>46.23,n=85).The incidence of postoperative complications in the high PNI group was lower than that in the low PNI group(21.18%vs 38.96%).Kaplan-Meier survival analysis showed that the overall survival rate at 5 years in the low PNI group was 87.96%(13/108),which was lower than that in the high PNI group(61.18%,33/85;P<0.05).Low PNI[hazard ratio(HR)=1.74;P=0.003]and positive incisal margin status(HR=2.14;P=0.001)were independent predictors of biological recurrence in patients with high/extremely high-risk PCa.CONCLUSION The PNI has predictive value for the prognosis of patients with high/extremely high-risk PCa,and is an independent prognostic factor.Patients with low PNI value have a shorter time of nonbiological recurrence after prostatectomy.It is expected that the combined prediction of other clinicopathological data will further improve the accuracy and guide postoperative adjuvant therapy to improve the quality of prognosis.
基金supported by the Shenzhen Overseas High-Level Talents Innovation Funds Peacock Plan Project (No. KQCX20120814155347053)the National Natural Science Foundation of China (No. 51108242)
文摘Nitrous oxide（N_2O） is a potent greenhouse gas that can be emitted during biological nitrogen removal. N_2O emission was examined in a multiple anoxic and aerobic process at the aeration rates of 600 m L/min sequencing batch reactor（SBRL） and 1200 m L/min（SBRH）.The nitrogen removal percentage was 89% in SBRLand 71% in SBRH, respectively. N_2O emission mainly occurred during the aerobic phase, and the N_2O emission factor was 10.1%in SBRLand 2.3% in SBRH, respectively. In all batch experiments, the N_2O emission potential was high in SBRLcompared with SBRH. In SBRL, with increasing aeration rates, the N_2O emission factor decreased during nitrification, while it increased during denitrification and simultaneous nitrification and denitrification（SND）. By contrast, in SBRHthe N_2O emission factor during nitrification, denitrification and SND was relatively low and changed little with increasing aeration rates. The microbial competition affected the N_2O emission during biological nitrogen removal.
基金Supported by the Key Research&Development Program-Social Development of Shaanxi Province of China,No.2021SF-163the Innovation Capability Support Plan of Shaanxi Province of China,No.2020KJXX-022.
文摘BACKGROUND Gastric cancer(GC)has high morbidity and mortality.Moreover,because GC has no typical symptoms in the early stages,most cases are already in the advanced stages by the time the symptoms appear,thus resulting in poor prognosis and a low survival rate.Endoscopic submucosal dissection(ESD)can realize the early detection and diagnosis of GC and become the main surgical method for early GC.However,ESD has a steep learning curve and high technical skill requirements for endoscopists,which is not conducive to its widespread implementation and advancement.Therefore,a series of auxiliary techniques have been derived.AIM To evaluate the safety and efficacy of magnetic anchor technique(MAT)-assisted ESD in early GC.METHODS This was an ex vivo animal experiment.The experimental models were the isolated stomachs of pigs,which were divided into two groups,namely the study group(n=6)with MAT-assisted ESD and the control group(n=6)with traditional ESD.Comparing the total surgical time,incidence of surgical complications,complete mucosal resection rate,specimen size,and the scores of endoscopist’s satisfaction with the procedure reflected their feelings about convenience during the surgical procedure between the two groups.The magnetic anchor device for auxiliary ESD in the study group comprised three parts,an anchor magnet(AM),a target magnet(TM),and a soft tissue clip.Under gastroscopic guidance,the soft tissue clip and the TM were delivered to the pre-marked mucosal lesion through the gastroscopic operating hole.The soft tissue clip and the TM were connected by a thin wire through the TM tail structure.The soft tissue clip was released by manipulating the operating handle of the soft tissue clip in a way that the soft tissue clip and the TM were fixed to the lesion mucosa.In vitro,ESD is aided by maneuvering the AM such that the mucosal dissection surface is exposed.RESULTS The total surgical time was shorter in the study group than in the control group(26.57±0.19 vs 29.97±0.28,P<0.001),and the scores of endoscopist’s satisfaction with the procedure were higher in the study group than in the control group(9.53±0.10 vs 8.00±0.22,P<0.001).During the operation in the study group,there was no detachment of the soft tissue clip and TM and no mucosal tearing.The magnetic force between the AM and TM provided good mucosal exposure and sufficient tissue tension for ESD.The mucosal lesion was completely peeled off,and the operation was successful.There were no significant differences in the incidence of surgical complications(100%vs 83.3%),complete mucosal resection rate(100%vs 66.7%,P=0.439),and specimen size(2.44±0.04 cm vs 2.49±0.02,P=0.328)between the two groups.CONCLUSION MAT-ESD is safe and effective for early GC.It provides a preliminary basis for subsequent internal animal experiments and clinical research.
基金supported by the Research Start-up Fund of Southwest Jiaotong University(No.~2019KY23)the Fundamental Research Funds for the Central Universities,China(No.2682019CX06)+1 种基金the National Natural Sciences Foundation of China(No.52204227,No.52072311)the Outstanding Young Scientific and Technical Talents in Sichuan Province,China(2019JDJQ0009).
文摘The double perovskites Sr_(2)SmNbO_(6),Sr_(2)CoNbO_(6)and Ba2CoNbO_(6)were investigated with first principles computations based on the density functional theory and plus U treatment.Firstly,different calculation methods were examined in order to quantitatively approach the exact band gap.It was found that neither the strongly constrained and appropriately normed(SCAN)semilocal density functional nor the hybrid HSE06 functional can well address the semiconducting nature of the investigated double perovskites,while PBEþU or SCANþU with appropriately determining the U value can have good performance,which paves the way for future studies of double perovskites.With self-consistently calculated electron correlation strength,the magnetic states and the band gaps of the Sr_(2)CoNbO_(6)and Ba_(2)CoNbO_(6)were more precisely determined.The electronic,optical and thermoelectric properties were then investigated and discussed for possible applications.
基金supported by Program of International S&T Cooperation(2013 DFA51050)National Magnetic Confinement Fusion Science Program(2013GB110001)+2 种基金the 863Program(2014AA032701)the National Natural Science Foundation of China(11405138,51302231)the Western Superconducting Technologies Co.,Ltd
文摘TiO2 films have been widely applied in photo- voltaic conversion techniques. TiO2 nanotube arrays （TiO2 NAs） can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi2S3 and PbS nanoparticles （NPs） were firstly co-sensitized on TiOa NAs （denoted as PbS/Bi2S3（n）/TiO2 NAs） by a two-step process containing hydrothermal and sonication-assisted SILAR method. When the concentration of Bi3＋ is 5 mmol/L, the best photoelectrical performance was obtained under simulated solar irradiation. The short-circuit photocurrent （Jsc） and photoconversion efficiency （η） of PbS/Bi2S3（5）/TiO2 NAs electrode were 4.70 mA/cm and 1.13 %, respectively.
基金financially supported by the Science Foundation for International Cooperation of Sichuan Province (2014HH0016)the Fundamental Research Funds for the Central Universities (SWJTU2014: A0920502051113-10000)National Magnetic Confinement Fusion Science Program (2011GB112001)
文摘Nb3Sn and other A15 members have been widely applied in nuclear power, nuclear magnetic resonance, and high-energy particle accelerators for their high critical current density （Jc） and upper critical field （Bc2）. There have been comprehensive and intensive studies on the applications, the fundamental lattice dynamic and electronic properties, etc., of A15 superconductors. Various reviews on the preparations, structures, and properties have already been written in the last few years. Nevertheless, on account of the large amount of existing facts and views, a coherent view on the relations between the structures and properties has not appeared to unify the facts. This article sketches a multi-scale point of view on the relations between the multi- scale structures and the corresponding properties.
基金supported by the Specialized Research Fund for the Doctoral Program of Higher Education (200806131034, 200806130023)Natural Science Foundation of China under Contract Nos. 50672078 and 50872116+6 种基金the National Science Fund for Distinguished Young Scholars under Contract No. 50588201, and 51102199the National High-Tech Program of China (863 Program) under Contract No. 2007AA03Z203the PCSIRT of the Ministry of Education of China (IRT0751)Research and Development Foundation of Southwest Jiao tong University under Grant Contract No. 2004A02Fundamental Research Funds for the Central Universities (SWJTU12CX019)the National Natural Science Foundation (51202202)Fundamental Research Funds for the Central Universities of China (SWJTU2682013CX005)
文摘YBa2Cu3O7-d （YBCO）-coated conductors havewide-ranging potential in large-scale applications such assuperconducting maglev trains and superconducting electriccables, but low current carrying capability restrains thepractical application of YBCO-coated conductors at hightemperatures and high magnetic fields. It is crucial todevelop YBCO-coated conductors with high critical currentdensity. In this paper, epitaxial, dense, smooth, andcrack-free Fe-doped YBCO films were prepared on aLaAlO3 single crystal substrate via a fluorine-free polymerassistedmetal organic deposition method. The effects ofthe dilute Fe doping on microstructure and superconductingcharacter of YBCO films were investigated. The criticaltemperature for superconducting of the Fe-dopedYBCO films decreases slightly. However, the in-fieldcritical current density of YBCO films improves with diluteFe doping of amounts less than x = 0.005, compared to thepure YBCO film. Therefore, the current carrying capabilityof YBCO film can improve by doping with appropriateamounts of Fe. This means that dilute Fe doping in YBCOfilms may be a feasible way to prepare high-performancecoated conductors.
基金Supported by Guangxi Guilin Science and Technology Fund,No.20190218-7-6.
文摘BACKGROUND Thymic carcinoid(TC)is a rare entity among anterior mediastinal malignancies.TCs are neuroendocrine carcinomas that constitute approximately 2%–5%of all thymic epithelial tumors.CASE SUMMARY The study reported a rare TC with multiple bone metastases.A 77-year-old man presented with a 2-month history of lower back pain and weight loss of 5 kg.Magnetic resonance imaging scans revealed damage to the lumbar spine,sacrocaudal vertebrae and iliac crest,suggesting bone metastasis;computed tomography(CT)scan of the thorax showed a calcified anterior mediastinal mass;positron emission tomography-CT demonstrated multiple abnormal bone signals;and laboratory work-up showed no endocrine abnormalities.Fine-needle aspiration biopsy revealed predominantly single small,round to oval cells with scant cytoplasm and some loose clusters,suggesting endocrine manifestations.The pathological diagnosis was atypical carcinoid,which tend to originate from the thymus and was classified as intermediate-highly invasive.The patient underwent anlotinib-targeted therapy.Anlotinib(12 mg)was administered daily for 2 wk,after which the patient was allowed to rest for 21 d.Follow-up CT after one year demonstrated that the tumor had shrunk by approximately 29%after therapy.Treatment has a long stable disease benefit of more than 2.5 years.CONCLUSION These findings demonstrated that anlotinib is a promising treatment regimen for patients with TC and multiple bone metastases.
