Low damping characteristics have always been a key sticking points in the development of gas bearings.The application of squeeze film dampers can significantly improve the damping performance of gas lubricated bearing...Low damping characteristics have always been a key sticking points in the development of gas bearings.The application of squeeze film dampers can significantly improve the damping performance of gas lubricated bearings.This paper proposed a novel hermetic diaphragm squeeze film damper(HDSFD)for oil-free turbomachinery supported by gas lubricated bearings.Several types of HDSFDs with symmetrical structure were proposed for good damping performance.By considering the compressibility of the damper fluid,based on hydraulic fluid mechanics theory,a dynamic model of HDSFDs under medium is proposed,which successfully reflects the frequency dependence of force coefficients.Based on the dynamic model,the effects of damper fluid viscosity,bulk modulus of damper fluid,thickness of damper fluid film and plunger thickness on the dynamic stiffness and damping of HDSFDs were analyzed.An experimental test rig was assembled and series of experimental studies on HDSFDs were conducted.The damper fluid transverse flow is added to the existing HDSFD concept,which aims to make the dynamic force coefficients independent of frequency.Although the force coefficient is still frequency dependent,the damping coefficient at high frequency excitation with damper fluid supply twice as that without damper fluid supply.The results serve as a benchmark for the calibration of analytical tools under development.展开更多
Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing ...Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing materials from LDHs.Herein,we designed heterostructure NiCo-LDHs@ZnO nanorod and then subsequent heat treating to derive NiCo@C/ZnO composites.Finally,with the synergy of excellent dielectric loss and magnetic loss,an outstanding absorption performance could be achieved with the reflection loss of−60.97 dB at the matching thickness of 2.3 mm,and the widest absorption bandwidth of 6.08 GHz was realized at 2.0 mm.Moreover,this research work provides a reference for the development and utilization of LDHs materials in the field of microwave absorption materials and can also provide ideas for the design of layered structural absorbers.展开更多
Background:Since December 2019,an outbreak of the Corona Virus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2)in Wuhan,China,has become a public health emergency of internatio...Background:Since December 2019,an outbreak of the Corona Virus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2)in Wuhan,China,has become a public health emergency of international concern.The high fatality of aged cases caused by SARS-CoV-2 was a need to explore the possible age-related phenomena with non-human primate models.Methods:Three 3-5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS-CoV-2,and then analyzed by clinical signs,viral replication,chest X-ray,histopathological changes and immune response.Results:Viral replication of nasopharyngeal swabs,anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS-CoV-2 challenge.Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema,notably,old monkeys exhibited diffuse severe interstitial pneumonia.Viral antigens were detected mainly in alveolar epithelial cells and macrophages.Conclusion:SARS-CoV-2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys.Rhesus macaque models infected with SARS-CoV-2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS-CoV-2 infection.展开更多
Recent developments in synthesis and nanofabrication technologies offer the tantalizing prospect of realizing various applications from twodimensional(2D)materials.A revolutionary development is to flexibly construct ...Recent developments in synthesis and nanofabrication technologies offer the tantalizing prospect of realizing various applications from twodimensional(2D)materials.A revolutionary development is to flexibly construct many different kinds of heterostructures with a diversity of 2D materials.These 2D heterostructures play an important role in semiconductor and condensed matter physics studies and are promising candidates for new device designs in the fields of integrated circuits and quantum sciences.Theoretical and experimental studies have focused on both vertical and lateral 2D heterostructures;the lateral heterostructures are considered to be easier for planner integration and exhibit unique electronic and photoelectronic properties.In this review,we give a summary of the properties of lateral heterostructures with homogeneous junction and heterogeneous junction,where the homogeneous junctions have the same host materials and the heterogeneous junctions are combined with different materials.Afterward,we discuss the applications and experimental synthesis of lateral 2D heterostructures.Moreover,a perspective on lateral 2D heterostructures is given at the end.展开更多
Nickel oxide(NiOx)has exhibited great potential as an inorganic hole transport layer(HTL)in perovskite solar cells(PSCs)due to its wide optical bandgap and superior stability.In this study,we have modulated the Ni26 v...Nickel oxide(NiOx)has exhibited great potential as an inorganic hole transport layer(HTL)in perovskite solar cells(PSCs)due to its wide optical bandgap and superior stability.In this study,we have modulated the Ni26 vacancies in NiOx film by controlling deposition temperature in a hot-casting process,resulting the change of coordination structure and charge state of NiOx.Moreover,the change of the HOMO level of NiOx makes it more compatible with perovskite to decrease energy losses and enhance hole carrier injection efficiency.Besides,the defect modulation in the electronic structure of NiOx is beneficial for increasing the electrical conductivity and mobility,which are considered to achieve the balance of charge carrier transport and avoid charge accumulation at the interface between perovskite and HTL effectively.Both experimental analyses and theoretical calculations reveal the increase of nickel vacancy defects change the electronic structure of NiOx by increasing the ratio of Ni3^+/Ni2^+-and improving the p-type characteristics.Accordingly,an optimal deposition temperature at 120℃enabled a 36.24%improvement in the power conversion efficiency compared to that deposited at room temperature(25℃).Therefore,this work provides a facile method to manipulate the electronic structure of NiOx to improve the charge carrier transport and photovoltaic performance of related PSCs.展开更多
Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and...Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and optimizing the ecosystem of science and technology innovation,this article summarizes the highlights of CAMS & PUMC’s efforts in safeguarding people’ s health and promoting the Healthy China 2030 strategy through scientific and technological innovation in the fields including basic research,disease prevention and treatment,and medical technology in the past ten years.These achievements embody the endeavors and responsibility of CAMS& PUMC in realizing self-reliance and self-improvement of Chinese medical science and technology and highlight its contributions to the development of medical science and technology of China.展开更多
The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide,with the pathogenesis mostly unclear.Both virus and host-derived microRNA(miRNA)play essential roles in the pathology of virus infection.This study ...The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide,with the pathogenesis mostly unclear.Both virus and host-derived microRNA(miRNA)play essential roles in the pathology of virus infection.This study aims to uncover the mechanism for SARS-CoV-2 pathogenicity from the perspective of miRNA.We scanned the SARS-CoV-2 genome for putative miRNA genes and miRNA targets and conducted in vivo experiments to validate the virus-encoded miRNAs and their regulatory role on the putative targets.One of such virus-encoded miRNAs,MR147-3p,was overexpressed that resulted in significantly decreased transcript levels of all of the predicted targets in human,i.e.,EXOC7,RAD9A,and TFE3 in the virus-infected cells.The analysis showed that the immune response and cytoskeleton organization are two of the most notable biological processes regulated by the infection-modulated miRNAs.Additionally,the genomic mutation of SARS-CoV-2 contributed to the changed miRNA repository and targets,suggesting a possible role of miRNAs in the attenuated phenotype of SARS-CoV-2 during its evolution.This study provided a comprehensive view of the miRNA-involved regulatory system during SARS-CoV-2 infection,indicating possible antiviral therapeutics against SARS-CoV-2 through intervening miRNA regulation.展开更多
Exploring the emergence and maintenance of cooperation in social dilemma is valuable and it arises considerable concerns of many researchers. In this paper, we propose a mechanism to promote cooperation, called benefi...Exploring the emergence and maintenance of cooperation in social dilemma is valuable and it arises considerable concerns of many researchers. In this paper, we propose a mechanism to promote cooperation, called benefit community,in which cooperators linking together form a common benefit community and all their payoffs obtained from game are divided coequally. The robustness of conclusions is tested for the PDG(prisoners' dilemma game) on square lattice and WS small world network. We find that cooperation can be promoted by this typical mechanism, especially, it can diffuse and prevail more easily and rapidly on the WS small world network than it on the square lattice, even if a big temptation to defect b. Our research provides a feasible direction to resolve the social dilemma.展开更多
Cardiovascular diseases are diseases related to blood vessels,heart and surrounding tissues which affect one’s health and normal life.Cardiovascular diseases include heart disease,stroke,endocarditis,arrhythmia,and m...Cardiovascular diseases are diseases related to blood vessels,heart and surrounding tissues which affect one’s health and normal life.Cardiovascular diseases include heart disease,stroke,endocarditis,arrhythmia,and more.The main causes of cardiovascular diseases are drinking,smoking,obesity,hypertension,diabetes,hyperlipidemia,and so on.In addition,there also are environmental factors and dietary factors.At present,the most basic disease treatment methods are life intervention and clinical intervention.When the disease is severe,it needs to be treated by surgical intervention.The effect of hypertension on patients’health is very significant,which is closely related to the incidence rate of cardiovascular disease.Therefore,this paper investigated and studied the development of hypertension and its impact on the risk of cardiovascular disease,and analyzed and summarized it in the form of review to provide references for clinical research.展开更多
The growth of γ-In_(2)Se_(3) thin films on mica by molecular beam epitaxy is studied. Single-crystalline γ-In_(2)Se_(3) is achieved at a relatively low growth temperature. An ultrathin β-In_(2)Se_(3) buffer layer i...The growth of γ-In_(2)Se_(3) thin films on mica by molecular beam epitaxy is studied. Single-crystalline γ-In_(2)Se_(3) is achieved at a relatively low growth temperature. An ultrathin β-In_(2)Se_(3) buffer layer is observed to nucleate and grow through a process of self-organization at initial deposition, which facilitates subsequent monolithic epitaxy of single-crystallineγ-In_(2)Se_(3) at low temperature. Strong room-temperature photoluminescence and moderate optoelectronic response are observed in the achieved γ-In_(2)Se_(3) thin films.展开更多
Quantum communications aim to share encryption keys between the transmitters and receivers governed by the laws of quantum mechanics.Integrated quantum photonics offers significant advantages of dense integration,high...Quantum communications aim to share encryption keys between the transmitters and receivers governed by the laws of quantum mechanics.Integrated quantum photonics offers significant advantages of dense integration,high stability and scalability,which enables a vital platform for the implementation of quantum information processing and quantum communications.This article reviews recent experimental progress and advances in the development of integrated quantum photonic devices and systems for quantum communications and quantum networks.展开更多
Objective: To evaluate X-linked inhibitor of apoptosis protein (XIAP) expression in biopsy specimens from the patients with stage lib osteosarcomas before chemotherapy to study XIAP expression and its predictive si...Objective: To evaluate X-linked inhibitor of apoptosis protein (XIAP) expression in biopsy specimens from the patients with stage lib osteosarcomas before chemotherapy to study XIAP expression and its predictive significance of progosis in stage lib osteosarcomas. Methods: The expression of XIAP was retrospectively detected by SP immunohistochem- istry in 31 cases biopsy specimens from stage lib osteosarcomas before chemotherapy, and the relationship between XIAP expression and clinicopathologic features of the patients with stage lib osteosarcomas was analyzed. Results: The osteo- sarcoma specimens showed strong cell nucleus immunoreaction of XIAP while normal bone specimens showed weak. High XIAP positive expression independently predicted the patient's poor outcome and had no relationship with clinicopathologic variables such as age, gender, location, tumor size, rate of tumor necrosis to preoperative chemotherapy, local recurrence (P 〉 0.05). Significant correlations were found between high XIAP expression and metastasis (P -- 0.022), and also between high XIAP expression and final survival (P = 0.011). Conclusion: XIAP plays an important role in the development of stage liB osteosarcomas and XIAP expression of biopsy specimens before chemotherapy can be seen as a promising prognostic marker in early predicting the outcome of patients suffering from stage lib osteosarcomas,展开更多
Hepatic inflammatory pseudotumor(IPT)is a benign lesion characterized by chronic infiltration of inflammatory cells and fibrosis that clinically,radiologically,and pathologically mimics malignancy.However,the epidemio...Hepatic inflammatory pseudotumor(IPT)is a benign lesion characterized by chronic infiltration of inflammatory cells and fibrosis that clinically,radiologically,and pathologically mimics malignancy.However,the epidemiology of IPTs remains unclear.IPTs are often misdiagnosed as malignant lesions because of the lack of characteristic features.We present the case of a 32-year-old man that was misdiagnosed as intrahepatic cholangiocarcinoma by CECT,CEMRI,and CEUS,which was finally confirmed as IPT by fine-needle liver biopsy.In this report,the key factor in the diagnosis of liver inflammatory masses was the presence of hepatic perfusion disorder.展开更多
The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministr...The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministry of Agriculture and Rural Affairs,P.R.China carried out by 24 institutes and universities that located in the Yangtze River basin surveys the status of(1)fish species composition and spatial distribution,(2)current fish abundance,(3)endangered fishes,(4)Yangtze finless porpoise,(5)aquatic eco-environments,(6)water-level fluctuation areas,(7)capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries,including Yalong River,Heng River,Min River(including Dadu River),Chishui River,Tuo River,Jialing River,Wu River,Han River,Dongting Lake and Poyang Lake.The results showed that there were 443 fish species(belonging to 163 genus,37 families,and 18 orders)before 2017,but only 323 fish species(including 15 new recorded exotic species)were recorded in the project of 2017-2021.Among them,Cyprinus carpio,Carassius auratus,Hypophthalmichthys molitrix,Pelteobagrus fulvidraco,Coilia brachygnathus,Silurus asotus,Saurogobio dabryi,Ctenopharyngodon idellus,Pelteobagrus nitidus,Hemiculter leucisculus,Siniperca chuatsi,Coreius heterodon,Culter alburnus,Parabramis pekinensis,and Aristichthys nobilis were the dominant species across the whole Yangtze River system.It is estimated that there were 886 million individuals weighing 124.8 million kg,merely equivalent to 27.3%of the resources in 1950s,30.9%of the resources in 1960s,or 58.7%of the resources in 1980s.In the new list of protected fishes that recorded in the Yangtze River system,only 15 of 29 were collected in this project of 2017-2021.Psephurus gladius has been affirmed to be Extinct by International Union for Conservation of Nature(IUCN).The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct already.Acipenser dabryanus has been affirmed to be Extinct in the Wild by IUCN.The natural propagations of A.sinensis,Myxocyprinus asiaticus and Trachidermus fasciatus have been interrupted for many years.The populations of Yangtze finless porpoise in the Yangtze River mainstream,Dongting Lake and Poyang Lake have steadily rising sizes and expanding distributions in 2017-2021.Parts of them migrate from one region to another with the seasons,which would result in the fluctuation of Yangtze finless porpoise population within some regions.The conventional indicators of water quality in the Yangtze River system were good and conformed to the water quality criteria of fishery in 2017-2021.In the last 40 years,the maximum surface water area in the Yangtze River basin extended to approximately 63,360 km2,the minimum surface water area covered approximately 26,396 km2,and the seasonal water-level fluctuation areas occupied approximately 36,964 km2.Compared with 1984-2000 period,the 2001-2020 period witnessed an overall decreasing trend in the frequency of surface water occurrence within about 25,869 km2 of aquatic areas.From 1984 to 2000 period to 2001-2020 period,permanent surface water has decreased by nearly 8,750 km2.In 2017,the fishermen were mainly 40-60 years old and their educational levels were mainly lower than junior high school.In 2017,most anglers were older than 40 and used hand rod and/or sea rod.Their average catch of each time was mainly less than 1 kg.Results suggested that the fishing ban in key waters of the Yangtze River basin is not only an ecological project of aquatic ecosystem conservation,but also a livelihood project for the fisherman to embrace industrial transformation and improve their living conditions.After the implementation of the fishing ban,the fisheries resources would gradually recover,and the Yangtze finless porpoise population size would also see a steady increase.However,the endangered species would remain threatened for a long time.The degraded waterbodies and water-level fluctuation areas would be the key restrictive factors for future aquatic ecosystem recovery in the Yangtze River basin.Since this survey was carried out before the fishing ban,the current results could provide a baseline for future evaluation of the effect of the Yangtze River fishing ban.展开更多
The destruction of the intestinal barrier is likely to cause an increase in intestinal permeability and cause pathological damage.Numerous studies have demonstrated that intestinal barrier function plays an important ...The destruction of the intestinal barrier is likely to cause an increase in intestinal permeability and cause pathological damage.Numerous studies have demonstrated that intestinal barrier function plays an important role in the occurrence and development of inflammatory bowel disease(IBD).Oral administration is the most common route for intestinal diseases.In this study,a synergistic strategy is proposed for IBD management through active barrier repair combined with anti-inflammatory treatment,which can interrupt the pathological process of IBD,resulting in the significantly improved efficacy of existing treatments.Based on the specific pH values and high reactive oxygen species(ROS)levels in inflammatory sites of IBD,an orally administrated ROS-responsive drug delivery system targeting inflamed colon has been designed,and confirmed in vitro and in vivo.The anti-inflammatory drug dexamethasone acetate(Dex)and the barrier function regulator LY294002 are delivered by the synthesized nanocarrier to treat IBD synergistically by inhibiting inflammation and actively repairing the intestinal barrier through tight junctions(TJs).The accumulation of nanocarriers in the inflamed colon and synergistic efficacy has been validated in mice with colitis.In brief,a drug delivery system and a therapeutic strategy for IBD are successfully developed.展开更多
Simulating the dynamic evolution of physical and molecular systems in a quantum computer is of fundamental interest in many applications.The implementation of dynamics simulation requires efficient quantum algorithms....Simulating the dynamic evolution of physical and molecular systems in a quantum computer is of fundamental interest in many applications.The implementation of dynamics simulation requires efficient quantum algorithms.The Lie-Trotter-Suzuki approximation algorithm,also known as the Trotterization,is basic in Hamiltonian dynamics simulation.A multi-product algorithm that is a linear combination of multiple Trotterizations has been proposed to improve the approximation accuracy.However,implementing such multiproduct Trotterization in quantum computers remains challenging due to the requirements of highly controllable and precise quantum entangling operations with high success probability.Here,we report a programmable integrated-photonic quantum simulator based on a linear combination of unitaries,which can be tailored for implementing the linearly combined multiple Trotterizations,and on the simulator we benchmark quantum simulation of Hamiltonian dynamics.We modify the multi-product algorithm by integrating it with oblivious amplitude amplification to simultaneously reach high simulation precision and high success probability.The quantum simulator is devised and fabricated on a large-scale silicon-photonic quantum chip,which allows the initialization,manipulation,and measurement of arbitrary four-qubit states and linearly combined unitary gates.As an example,the quantum simulator is reprogrammed to emulate the dynamics of an electron spin and nuclear spin coupled system.This work promises the practical dynamics simulations of real-world physical and molecular systems in future large-scale quantum computers.展开更多
基金supported by the National Natural Science Foundation of China (31872261)the project of Northeast Asia Biodiversity Research Center (2572022DS09)the Fundamental Research Funds for the Central Universities (2572021DJ08,2572019CP11)。
基金Supported by National Key Research and Development Program of China (Grant No.2021YFF0600208)National Natural Science Foundation of China (Grant No.52005170)Hunan Provincial Science and Technology Innovation Program of China (Grant No.2020RC4018)。
文摘Low damping characteristics have always been a key sticking points in the development of gas bearings.The application of squeeze film dampers can significantly improve the damping performance of gas lubricated bearings.This paper proposed a novel hermetic diaphragm squeeze film damper(HDSFD)for oil-free turbomachinery supported by gas lubricated bearings.Several types of HDSFDs with symmetrical structure were proposed for good damping performance.By considering the compressibility of the damper fluid,based on hydraulic fluid mechanics theory,a dynamic model of HDSFDs under medium is proposed,which successfully reflects the frequency dependence of force coefficients.Based on the dynamic model,the effects of damper fluid viscosity,bulk modulus of damper fluid,thickness of damper fluid film and plunger thickness on the dynamic stiffness and damping of HDSFDs were analyzed.An experimental test rig was assembled and series of experimental studies on HDSFDs were conducted.The damper fluid transverse flow is added to the existing HDSFD concept,which aims to make the dynamic force coefficients independent of frequency.Although the force coefficient is still frequency dependent,the damping coefficient at high frequency excitation with damper fluid supply twice as that without damper fluid supply.The results serve as a benchmark for the calibration of analytical tools under development.
基金This work was financially supported by the National Natural Science Foundation of China(No.51407134)Natural Science Foundation of Shandong Province(No.ZR2019YQ24)+3 种基金Taishan Scholars and Young Experts Program of Shandong Province(No.tsqn202103057)China Postdoctoral Science Foundation(No.2016M590619)the Qingchuang Talents Induction Program of Shandong Higher Education Institution(Research and Innovation Team of Structural-Functional Polymer Composites)The authors acknowledge the support from The Thousand Talents Plan,The World-Class University and Discipline,The Taishan Scholar’s Advantageous and Distinctive Discipline Program of Shandong Province and The World-Class Discipline Program of Shandong Province.
文摘Layered double hydroxides(LDHs)have a special structure and atom composition,which are expected to be an excellent electromagnetic wave(EMW)absorber.However,it is still a problem that obtaining excellent EMWabsorbing materials from LDHs.Herein,we designed heterostructure NiCo-LDHs@ZnO nanorod and then subsequent heat treating to derive NiCo@C/ZnO composites.Finally,with the synergy of excellent dielectric loss and magnetic loss,an outstanding absorption performance could be achieved with the reflection loss of−60.97 dB at the matching thickness of 2.3 mm,and the widest absorption bandwidth of 6.08 GHz was realized at 2.0 mm.Moreover,this research work provides a reference for the development and utilization of LDHs materials in the field of microwave absorption materials and can also provide ideas for the design of layered structural absorbers.
基金This work was supported by the National Research and Development Project of China(Grant No.2020YFC0841100)Fundamental Research Funds for CAMS of China(Grant No.2020HY320001)+3 种基金National Key Research and Development Project of China(Grant No.2016YFD0500304)CAMS initiative for Innovative Medicine of China(Grant No.2016-I2M-2-006)National Mega projects of China for Major Infectious Diseases(Grant No.2017ZX10304402)and National Key Research and Development Programme of China(2016YFD0500301,2020YFC0840800,2020YFC0840900).
文摘Background:Since December 2019,an outbreak of the Corona Virus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus(SARS-CoV-2)in Wuhan,China,has become a public health emergency of international concern.The high fatality of aged cases caused by SARS-CoV-2 was a need to explore the possible age-related phenomena with non-human primate models.Methods:Three 3-5 years old and two 15 years old rhesus macaques were intratracheally infected with SARS-CoV-2,and then analyzed by clinical signs,viral replication,chest X-ray,histopathological changes and immune response.Results:Viral replication of nasopharyngeal swabs,anal swabs and lung in old monkeys was more active than that in young monkeys for 14 days after SARS-CoV-2 challenge.Monkeys developed typical interstitial pneumonia characterized by thickened alveolar septum accompanied with inflammation and edema,notably,old monkeys exhibited diffuse severe interstitial pneumonia.Viral antigens were detected mainly in alveolar epithelial cells and macrophages.Conclusion:SARS-CoV-2 caused more severe interstitial pneumonia in old monkeys than that in young monkeys.Rhesus macaque models infected with SARS-CoV-2 provided insight into the pathogenic mechanism and facilitated the development of vaccines and therapeutics against SARS-CoV-2 infection.
基金the National Key Research and Development Program of China (No. 2018YFA0306100)National Natural Science Foundation of China (No. 61604140)Thousand Talents Program
文摘Recent developments in synthesis and nanofabrication technologies offer the tantalizing prospect of realizing various applications from twodimensional(2D)materials.A revolutionary development is to flexibly construct many different kinds of heterostructures with a diversity of 2D materials.These 2D heterostructures play an important role in semiconductor and condensed matter physics studies and are promising candidates for new device designs in the fields of integrated circuits and quantum sciences.Theoretical and experimental studies have focused on both vertical and lateral 2D heterostructures;the lateral heterostructures are considered to be easier for planner integration and exhibit unique electronic and photoelectronic properties.In this review,we give a summary of the properties of lateral heterostructures with homogeneous junction and heterogeneous junction,where the homogeneous junctions have the same host materials and the heterogeneous junctions are combined with different materials.Afterward,we discuss the applications and experimental synthesis of lateral 2D heterostructures.Moreover,a perspective on lateral 2D heterostructures is given at the end.
基金financially supported by the National Natural Science Foundation of China NSFC(51702038)the Recruitment Program for Young Professionals+1 种基金the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,21961160720)for financial support。
文摘Nickel oxide(NiOx)has exhibited great potential as an inorganic hole transport layer(HTL)in perovskite solar cells(PSCs)due to its wide optical bandgap and superior stability.In this study,we have modulated the Ni26 vacancies in NiOx film by controlling deposition temperature in a hot-casting process,resulting the change of coordination structure and charge state of NiOx.Moreover,the change of the HOMO level of NiOx makes it more compatible with perovskite to decrease energy losses and enhance hole carrier injection efficiency.Besides,the defect modulation in the electronic structure of NiOx is beneficial for increasing the electrical conductivity and mobility,which are considered to achieve the balance of charge carrier transport and avoid charge accumulation at the interface between perovskite and HTL effectively.Both experimental analyses and theoretical calculations reveal the increase of nickel vacancy defects change the electronic structure of NiOx by increasing the ratio of Ni3^+/Ni2^+-and improving the p-type characteristics.Accordingly,an optimal deposition temperature at 120℃enabled a 36.24%improvement in the power conversion efficiency compared to that deposited at room temperature(25℃).Therefore,this work provides a facile method to manipulate the electronic structure of NiOx to improve the charge carrier transport and photovoltaic performance of related PSCs.
文摘Focusing on the reform initiatives of Chinese Academy of Medical Sciences(CAMS) & Peking Union Medical College(PUMC) in medical scientific and technological innovation from perspectives of deepening the reform and optimizing the ecosystem of science and technology innovation,this article summarizes the highlights of CAMS & PUMC’s efforts in safeguarding people’ s health and promoting the Healthy China 2030 strategy through scientific and technological innovation in the fields including basic research,disease prevention and treatment,and medical technology in the past ten years.These achievements embody the endeavors and responsibility of CAMS& PUMC in realizing self-reliance and self-improvement of Chinese medical science and technology and highlight its contributions to the development of medical science and technology of China.
基金This work was supported by National Natural Science Foundation of China(NSFC)grant No.81671983 and 81871628 to X.L.,NSFC grant No.81703306China Postdoctoral Science Foundation(2017M611867)+1 种基金Postdoctoral Science Foundation of Jiangsu Province(1701119C)to Z.L.,NSFC grant No.81902027Natural Science Foundation of Jiangsu Province to J.W.(BK20171045).
文摘The outbreak of COVID-19 caused by SARS-CoV-2 is spreading worldwide,with the pathogenesis mostly unclear.Both virus and host-derived microRNA(miRNA)play essential roles in the pathology of virus infection.This study aims to uncover the mechanism for SARS-CoV-2 pathogenicity from the perspective of miRNA.We scanned the SARS-CoV-2 genome for putative miRNA genes and miRNA targets and conducted in vivo experiments to validate the virus-encoded miRNAs and their regulatory role on the putative targets.One of such virus-encoded miRNAs,MR147-3p,was overexpressed that resulted in significantly decreased transcript levels of all of the predicted targets in human,i.e.,EXOC7,RAD9A,and TFE3 in the virus-infected cells.The analysis showed that the immune response and cytoskeleton organization are two of the most notable biological processes regulated by the infection-modulated miRNAs.Additionally,the genomic mutation of SARS-CoV-2 contributed to the changed miRNA repository and targets,suggesting a possible role of miRNAs in the attenuated phenotype of SARS-CoV-2 during its evolution.This study provided a comprehensive view of the miRNA-involved regulatory system during SARS-CoV-2 infection,indicating possible antiviral therapeutics against SARS-CoV-2 through intervening miRNA regulation.
基金Project supported by the National Natural Science Foundation of China(Grant No.61673096)the Fundamental Research Funds for the Central Universities,China(Grant No.N160602002)+1 种基金the Social Science Project of the Ministry of Education of China(Grant No.16YJC630118)the Project of Promoting Talents in Liaoning Province,China(Grant No.XLYC1807033)
文摘Exploring the emergence and maintenance of cooperation in social dilemma is valuable and it arises considerable concerns of many researchers. In this paper, we propose a mechanism to promote cooperation, called benefit community,in which cooperators linking together form a common benefit community and all their payoffs obtained from game are divided coequally. The robustness of conclusions is tested for the PDG(prisoners' dilemma game) on square lattice and WS small world network. We find that cooperation can be promoted by this typical mechanism, especially, it can diffuse and prevail more easily and rapidly on the WS small world network than it on the square lattice, even if a big temptation to defect b. Our research provides a feasible direction to resolve the social dilemma.
文摘Cardiovascular diseases are diseases related to blood vessels,heart and surrounding tissues which affect one’s health and normal life.Cardiovascular diseases include heart disease,stroke,endocarditis,arrhythmia,and more.The main causes of cardiovascular diseases are drinking,smoking,obesity,hypertension,diabetes,hyperlipidemia,and so on.In addition,there also are environmental factors and dietary factors.At present,the most basic disease treatment methods are life intervention and clinical intervention.When the disease is severe,it needs to be treated by surgical intervention.The effect of hypertension on patients’health is very significant,which is closely related to the incidence rate of cardiovascular disease.Therefore,this paper investigated and studied the development of hypertension and its impact on the risk of cardiovascular disease,and analyzed and summarized it in the form of review to provide references for clinical research.
基金Project supported by the National Key R&D Program of China(Grant Nos.2018YFA0306102 and 2018YFA0306703)the National Natural Science Foundation of China(Grant No.61474014)+1 种基金the Sichuan Science and Technology Program,China(Grant No.2019YJ0202)the University Program for Elaborate Courses of Postgraduates。
文摘The growth of γ-In_(2)Se_(3) thin films on mica by molecular beam epitaxy is studied. Single-crystalline γ-In_(2)Se_(3) is achieved at a relatively low growth temperature. An ultrathin β-In_(2)Se_(3) buffer layer is observed to nucleate and grow through a process of self-organization at initial deposition, which facilitates subsequent monolithic epitaxy of single-crystallineγ-In_(2)Se_(3) at low temperature. Strong room-temperature photoluminescence and moderate optoelectronic response are observed in the achieved γ-In_(2)Se_(3) thin films.
基金support from the Natural Science Foundation of China(61975001)National Key R&D Program of China(2018YFB1107205)+1 种基金Beijing Natural Science Foundation(Z190005)the Key R&D Program of Guangdong Province(2018B030329001).
文摘Quantum communications aim to share encryption keys between the transmitters and receivers governed by the laws of quantum mechanics.Integrated quantum photonics offers significant advantages of dense integration,high stability and scalability,which enables a vital platform for the implementation of quantum information processing and quantum communications.This article reviews recent experimental progress and advances in the development of integrated quantum photonic devices and systems for quantum communications and quantum networks.
基金a grant from the Foundation for Scientific Research of Medical Science of Guangzhou (No. 2006-YB-017).
文摘Objective: To evaluate X-linked inhibitor of apoptosis protein (XIAP) expression in biopsy specimens from the patients with stage lib osteosarcomas before chemotherapy to study XIAP expression and its predictive significance of progosis in stage lib osteosarcomas. Methods: The expression of XIAP was retrospectively detected by SP immunohistochem- istry in 31 cases biopsy specimens from stage lib osteosarcomas before chemotherapy, and the relationship between XIAP expression and clinicopathologic features of the patients with stage lib osteosarcomas was analyzed. Results: The osteo- sarcoma specimens showed strong cell nucleus immunoreaction of XIAP while normal bone specimens showed weak. High XIAP positive expression independently predicted the patient's poor outcome and had no relationship with clinicopathologic variables such as age, gender, location, tumor size, rate of tumor necrosis to preoperative chemotherapy, local recurrence (P 〉 0.05). Significant correlations were found between high XIAP expression and metastasis (P -- 0.022), and also between high XIAP expression and final survival (P = 0.011). Conclusion: XIAP plays an important role in the development of stage liB osteosarcomas and XIAP expression of biopsy specimens before chemotherapy can be seen as a promising prognostic marker in early predicting the outcome of patients suffering from stage lib osteosarcomas,
文摘Hepatic inflammatory pseudotumor(IPT)is a benign lesion characterized by chronic infiltration of inflammatory cells and fibrosis that clinically,radiologically,and pathologically mimics malignancy.However,the epidemiology of IPTs remains unclear.IPTs are often misdiagnosed as malignant lesions because of the lack of characteristic features.We present the case of a 32-year-old man that was misdiagnosed as intrahepatic cholangiocarcinoma by CECT,CEMRI,and CEUS,which was finally confirmed as IPT by fine-needle liver biopsy.In this report,the key factor in the diagnosis of liver inflammatory masses was the presence of hepatic perfusion disorder.
文摘The Yangtze River is the mother river of China.To promote the aquatic ecosystem protection of the great river,the Project of Yangtze Fisheries Resources and Environment Investigation(2017-2021)supported by the Ministry of Agriculture and Rural Affairs,P.R.China carried out by 24 institutes and universities that located in the Yangtze River basin surveys the status of(1)fish species composition and spatial distribution,(2)current fish abundance,(3)endangered fishes,(4)Yangtze finless porpoise,(5)aquatic eco-environments,(6)water-level fluctuation areas,(7)capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries,including Yalong River,Heng River,Min River(including Dadu River),Chishui River,Tuo River,Jialing River,Wu River,Han River,Dongting Lake and Poyang Lake.The results showed that there were 443 fish species(belonging to 163 genus,37 families,and 18 orders)before 2017,but only 323 fish species(including 15 new recorded exotic species)were recorded in the project of 2017-2021.Among them,Cyprinus carpio,Carassius auratus,Hypophthalmichthys molitrix,Pelteobagrus fulvidraco,Coilia brachygnathus,Silurus asotus,Saurogobio dabryi,Ctenopharyngodon idellus,Pelteobagrus nitidus,Hemiculter leucisculus,Siniperca chuatsi,Coreius heterodon,Culter alburnus,Parabramis pekinensis,and Aristichthys nobilis were the dominant species across the whole Yangtze River system.It is estimated that there were 886 million individuals weighing 124.8 million kg,merely equivalent to 27.3%of the resources in 1950s,30.9%of the resources in 1960s,or 58.7%of the resources in 1980s.In the new list of protected fishes that recorded in the Yangtze River system,only 15 of 29 were collected in this project of 2017-2021.Psephurus gladius has been affirmed to be Extinct by International Union for Conservation of Nature(IUCN).The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct already.Acipenser dabryanus has been affirmed to be Extinct in the Wild by IUCN.The natural propagations of A.sinensis,Myxocyprinus asiaticus and Trachidermus fasciatus have been interrupted for many years.The populations of Yangtze finless porpoise in the Yangtze River mainstream,Dongting Lake and Poyang Lake have steadily rising sizes and expanding distributions in 2017-2021.Parts of them migrate from one region to another with the seasons,which would result in the fluctuation of Yangtze finless porpoise population within some regions.The conventional indicators of water quality in the Yangtze River system were good and conformed to the water quality criteria of fishery in 2017-2021.In the last 40 years,the maximum surface water area in the Yangtze River basin extended to approximately 63,360 km2,the minimum surface water area covered approximately 26,396 km2,and the seasonal water-level fluctuation areas occupied approximately 36,964 km2.Compared with 1984-2000 period,the 2001-2020 period witnessed an overall decreasing trend in the frequency of surface water occurrence within about 25,869 km2 of aquatic areas.From 1984 to 2000 period to 2001-2020 period,permanent surface water has decreased by nearly 8,750 km2.In 2017,the fishermen were mainly 40-60 years old and their educational levels were mainly lower than junior high school.In 2017,most anglers were older than 40 and used hand rod and/or sea rod.Their average catch of each time was mainly less than 1 kg.Results suggested that the fishing ban in key waters of the Yangtze River basin is not only an ecological project of aquatic ecosystem conservation,but also a livelihood project for the fisherman to embrace industrial transformation and improve their living conditions.After the implementation of the fishing ban,the fisheries resources would gradually recover,and the Yangtze finless porpoise population size would also see a steady increase.However,the endangered species would remain threatened for a long time.The degraded waterbodies and water-level fluctuation areas would be the key restrictive factors for future aquatic ecosystem recovery in the Yangtze River basin.Since this survey was carried out before the fishing ban,the current results could provide a baseline for future evaluation of the effect of the Yangtze River fishing ban.
基金the National Natural Science Foundation of China(No.81973267)the Zhejiang Provincial Natural Science Foundation of China(No.LZ22H060001).
文摘The destruction of the intestinal barrier is likely to cause an increase in intestinal permeability and cause pathological damage.Numerous studies have demonstrated that intestinal barrier function plays an important role in the occurrence and development of inflammatory bowel disease(IBD).Oral administration is the most common route for intestinal diseases.In this study,a synergistic strategy is proposed for IBD management through active barrier repair combined with anti-inflammatory treatment,which can interrupt the pathological process of IBD,resulting in the significantly improved efficacy of existing treatments.Based on the specific pH values and high reactive oxygen species(ROS)levels in inflammatory sites of IBD,an orally administrated ROS-responsive drug delivery system targeting inflamed colon has been designed,and confirmed in vitro and in vivo.The anti-inflammatory drug dexamethasone acetate(Dex)and the barrier function regulator LY294002 are delivered by the synthesized nanocarrier to treat IBD synergistically by inhibiting inflammation and actively repairing the intestinal barrier through tight junctions(TJs).The accumulation of nanocarriers in the inflamed colon and synergistic efficacy has been validated in mice with colitis.In brief,a drug delivery system and a therapeutic strategy for IBD are successfully developed.
基金Innovation Program for Quantum Science and Technology(2021ZD0301500)Key R&D Program of Guangdong Province(2018B030329001)+2 种基金Beijing Natural Science Foundation(Z190005,Z220008)National Natural Science Foundation of China(12325410,61975001,62235001)National Key Research and Development Program of China(2019YFA0308702)。
文摘Simulating the dynamic evolution of physical and molecular systems in a quantum computer is of fundamental interest in many applications.The implementation of dynamics simulation requires efficient quantum algorithms.The Lie-Trotter-Suzuki approximation algorithm,also known as the Trotterization,is basic in Hamiltonian dynamics simulation.A multi-product algorithm that is a linear combination of multiple Trotterizations has been proposed to improve the approximation accuracy.However,implementing such multiproduct Trotterization in quantum computers remains challenging due to the requirements of highly controllable and precise quantum entangling operations with high success probability.Here,we report a programmable integrated-photonic quantum simulator based on a linear combination of unitaries,which can be tailored for implementing the linearly combined multiple Trotterizations,and on the simulator we benchmark quantum simulation of Hamiltonian dynamics.We modify the multi-product algorithm by integrating it with oblivious amplitude amplification to simultaneously reach high simulation precision and high success probability.The quantum simulator is devised and fabricated on a large-scale silicon-photonic quantum chip,which allows the initialization,manipulation,and measurement of arbitrary four-qubit states and linearly combined unitary gates.As an example,the quantum simulator is reprogrammed to emulate the dynamics of an electron spin and nuclear spin coupled system.This work promises the practical dynamics simulations of real-world physical and molecular systems in future large-scale quantum computers.