Colorectal cancer(CRC)is the third leading cause of cancer deaths worldwide and the fourth most common cancer diagnosed among men and women in the United States.Considering the risk factors of CRC,dietary therapy has ...Colorectal cancer(CRC)is the third leading cause of cancer deaths worldwide and the fourth most common cancer diagnosed among men and women in the United States.Considering the risk factors of CRC,dietary therapy has become one of the most effective approaches in reducing CRC morbidity and mortality.The use of probiotics is increasing in popularity for both the prevention and treatment of a variety of diseases.As the most common types of microbes used as probiotics,lactic acid bacteria(LAB)are comprised of an ecologically diverse group of microorganisms united by formation of lactic acid as the primary metabolite of sugar metabolism.LAB have been successfully used in managing diarrhea,food allergies,and inflammatory bowel disease.LAB also demonstrated a host of properties in preventing colorectal cancer development by inhibiting initiation or progression through multiple pathways.In this review,we discuss recent insights into cellular and molecular mechanisms of LAB in CRC prevention including apoptosis,antioxidant DNA damages,immune responses,and epigenetics.The emerging experimental findings from clinical trials as well as the proposed mechanisms of gut microbiota in carcinogenesis will also be briefly discussed.展开更多
On January 22,2020,China National Center for Bioinformation(CNCB)released the 2019 Novel Coronavirus Resource(2019nCoVR),an open-access information resource for the severe acute respiratory syndrome coronavirus 2(SARS...On January 22,2020,China National Center for Bioinformation(CNCB)released the 2019 Novel Coronavirus Resource(2019nCoVR),an open-access information resource for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).2019nCoVR features a comprehensive integration of sequence and clinical information for all publicly available SARS-CoV-2 isolates,which are manually curated with value-added annotations and quality evaluated by an automated in-house pipeline.Of particular note,2019nCoVR offers systematic analyses to generate a dynamic landscape of SARS-CoV-2 genomic variations at a global scale.It provides all identified variants and their detailed statistics for each virus isolate,and congregates the quality score,functional annotation,and population frequency for each variant.Spatiotemporal change for each variant can be visualized and historical viral haplotype network maps for the course of the outbreak are also generated based on all complete and high-quality genomes available.Moreover,2019nCoVR provides a full collection of SARS-CoV-2 relevant literature on the coronavirus disease 2019(COVID-19),including published papers from PubMed as well as preprints from services such as bioRxiv and medRxiv through Europe PMC.Furthermore,by linking with relevant databases in CNCB,2019nCoVR offers data submission services for raw sequence reads and assembled genomes,and data sharing with NCBI.Collectively,SARS-CoV-2 is updated daily to collect the latest information on genome sequences,variants,haplotypes,and literature for a timely reflection,making 2019nCoVR a valuable resource for the global research community.2019nCoVR is accessible at https://bigd.big.ac.cn/ncov/.展开更多
Social media websites allow users to exchange short texts such as tweets via microblogs and user status in friendship networks. Their limited length, pervasive abbrevi- ations, and coined acronyms and words exacerbate...Social media websites allow users to exchange short texts such as tweets via microblogs and user status in friendship networks. Their limited length, pervasive abbrevi- ations, and coined acronyms and words exacerbate the prob- lems of synonymy and polysemy, and bring about new chal- lenges to data mining applications such as text clustering and classification. To address these issues, we dissect some poten- tial causes and devise an efficient approach that enriches data representation by employing machine translation to increase the number of features from different languages. Then we propose a novel framework which performs multi-language knowledge integration and feature reduction simultaneously through matrix factorization techniques. The proposed ap- proach is evaluated extensively in terms of effectiveness on two social media datasets from Facebook and Twitter. With its significant performance improvement, we further investi- gate potential factors that contribute to the improved perfor- mance.展开更多
The design, construction and test of an Organic Rankine Cycle(ORC) with R123 as the working fluid were performed. A scroll expander was integrated in the system.The conductive oil with its temperature of 150 °C w...The design, construction and test of an Organic Rankine Cycle(ORC) with R123 as the working fluid were performed. A scroll expander was integrated in the system.The conductive oil with its temperature of 150 °C was used to simulate the low-grade heat source. An AC dynamometer unit measured the expander shaft torque, rotating speed and shaft power. The experiments were conducted in two operating modes: the constant mass flow rate and the constant shaft torque. Under the constant mass flow rate operating mode, the stepped increase of the shaft torque increased the expansion ratios of the expander and decreased the vapor superheats at the expander inlet. Thus,the shaft power and thermal efficiency were increased.Alternatively, the constant shaft torque operating mode involved two different regions, interfaced at the pumping frequency of 9 Hz. By the increase of the mass flow rates,the vapor superheats at the expander inlet was decreased and the shaft power was increased, but the ORC thermal efficiencies were slightly decreased. Both operating modes yielded the saturation shaft powers that were the maximum values one could use. It was found that the measured shaft powers and ORC thermal efficiencies were lower than the enthalpy determined values based on the fluid pressures and temperatures at the expander inlet and outlet. The maximum measured shaft power and thermal efficiency were 2.63 kW and 5.31 %, compared with the enthalpy determined values of 3.87 kW and 9.46 %, respectively.展开更多
We present the continuously measurements of volatile organic compounds(VOCs)at a receptor site(Wan Qing Sha,WQS)in the Pearl River Delta(PRD)region from September to November of 2017.The average mixing ratios of total...We present the continuously measurements of volatile organic compounds(VOCs)at a receptor site(Wan Qing Sha,WQS)in the Pearl River Delta(PRD)region from September to November of 2017.The average mixing ratios of total VOCs(TVOCs)was 36.3±27.9 ppbv with the dominant contribution from alkanes(55.5%),followed by aromatics(33.3%).The diurnal variation of TVOCs showed a strong photochemical consumption during daytime,resulting in the formation of ozone(O_(3)).Five VOC sources were resolved by the positive matrix factorization(PMF)model,including solvent usage(28.6%),liquid petroleum gas(LPG)usage(24.4%),vehicle exhaust(21.0%),industrial emissions(13.2%)and gasoline evaporation(12.9%).The regional transport air masses from the upwind cities of south China can result in the elevated concentrations of TVOCs.Low ratios of TVOCs/NO_(x)(1.53±0.88)suggested that the O_(3) formation regime at WQS site was VOC-limited,which also confirmed by a photochemical box model with the master chemical mechanism(PBM-MCM).Furthermore,the observation on high-O_(3) episode days revealed that frequent O_(3) outbreaks at WQS were mainly caused by the regional transport of anthropogenic VOCs especially for aromatics and the subsequent photochemical reactions.This study provides valuable information for policymakers to propose the effective control strategies on photochemical pollution in a regional perspective.展开更多
An augmented flight dynamics model is developed to extend the existing flight dynamics model of tilt-rotor aircraft for optimal landing procedure analysis in the event of one engine failure.Compared with the existing ...An augmented flight dynamics model is developed to extend the existing flight dynamics model of tilt-rotor aircraft for optimal landing procedure analysis in the event of one engine failure.Compared with the existing flight dynamics model, the augmented model involves with more pilot control information in cockpit and is validated against the flight test data. Based on the augmented flight dynamics model, the optimal landing procedure of XV-15 tilt-rotor aircraft after one engine failure is formulated into a Nonlinear Optimal Control Problem(NOCP), solved by collocation and numerical optimization method. The time histories of pilot controls in cockpit during the optimal landing procedure are obtained for the evaluation of pilot workload. An evaluation method which can synthetically quantify the pilot workload in time and frequency domains is proposed with metrics of aggressiveness and cutoff frequencies of pilot controls. The scale of the pilot workload is compared with those of the shipboard landing procedures, bob-up/bob-down and dash/quickstop maneuvers of UH-60 helicopter. The results show that the aggressiveness of pilot collective and longitudinal controls for the tilt-rotor aircraft optimal landing procedure after one engine failure are higher than those for UH-60 helicopter shipboard landing procedures up to the condition of sea state 4, while the pilot cutoff frequency of collective control is lower than that of the bob-up/bob-down maneuver but the pilot cutoff frequency of longitudinal control is higher than that of the dash/quick-stop maneuver. The evaluated pilot workload level is between Cooper–Harper HQR Level 2 and Level 3.展开更多
OBJECTIVE:To summarize the evidence from Traditional Chinese Medicine(TCM)practice in the treatment of coronavirus disease 2019(COVID-19)and provide timely clinical practice guidance.METHODS:The guidelines were develo...OBJECTIVE:To summarize the evidence from Traditional Chinese Medicine(TCM)practice in the treatment of coronavirus disease 2019(COVID-19)and provide timely clinical practice guidance.METHODS:The guidelines were developed in accordance with the World Health Organization rapid guideline process.The evidence on TCM for COVID-19 from published guidelines,direct and indirect published clinical evidence,first hand clinical data,and expert experience and consensus were collected.The grading of recommendations assessment,development and evaluation(GRADE)method was used to grade the evidence and make the recommendations.RESULTS:Based on the available evidence,the guidelines recommended 17 Chinese medicines for COVID-19:2 Chinese herbal granules,7 Chinese patent medicines,and 8 Chinese herbal injections.CONCLUSION:As the literature search was conducted on March,any subsequent versions of these guidelines require an up-to-date literature review.We hope that the evidence summary in these guidelines will be helpful in global efforts to address COVID-19.展开更多
A novel thermal biosensor based on enzyme reaction for pesticides detection has been developed. This biosensor is a flow injection analysis system and consists of two channels with enzyme reaction column and identical...A novel thermal biosensor based on enzyme reaction for pesticides detection has been developed. This biosensor is a flow injection analysis system and consists of two channels with enzyme reaction column and identical reference column, which is set for eliminating the unspecific heat. The enzyme reaction takes place in the enzyme reaction column at a constant temperature(40℃) realized by a thermoelectric thermostat. Thermosensor based on the thermoelectric module containing 127 serial BiTe-thermocouples is used to monitor the temperature difference between two effluents from enzyme reaction column and reference column. The ability of this biosensor to detect pesticides is demonstrated by the decreased degree of the hydrolytic heat in two types of thermosensor mode. The hydrolytic reaction is inhibited by 36% at 1 mg/L DDVP and 50 % at 10 mg/L DDVP when cell-typed thermosensor is used. The percent inhibition is 30% at 1 mg/L DDVP and 42% at 10 mg/L DDVP in tube-typed thermosensor mode. The detection for real sample shows that this biosensor can be used for detection of organophosphate pesticides residue.展开更多
Intratumoral microbiota has become research hotspots,and emerges as a non-negligent new component of tumor microenvironments(TME),due to its powerful infuence on tumor initiation,metas-tasis,immunosurveillance and pro...Intratumoral microbiota has become research hotspots,and emerges as a non-negligent new component of tumor microenvironments(TME),due to its powerful infuence on tumor initiation,metas-tasis,immunosurveillance and prognosis despite in low-biomass.The accumulations of microbes,and their related components and metabolites within tumor tissues,endow TME with additional pluralistic features which are distinct from the conventional one.Therefore,it's definitely necessary to comprehen-sively delineate the sophisticated landscapes of tumor microbe microenvironment,as well as their func-tions and related underlying mechanisms.Herein,in this review,we focused on the fields of tumor microbe microenvironment,including the heterogeneity of intratumor microbiota in different types of tu-mors,the controversial roles of intratumoral microbiota,the basic features of tumor microbe microenvi-ronment(i.e.,pathogen-associated molecular patterns(PAMPs),typical microbial metabolites,autophagy,infammation,multi-faceted immunomodulation and chemoresistance),as well as the multi-disciplinary approach-based intervention of tumor microbiome for cancer therapy by applying wild-type or engineered live microbes,microbiota metabolites,antibiotics,synthetic biology and rationally de-signed biomaterials.We hope our work will provide valuable insight to deeply understand the interplay of cancer-immune-microbial,and facilitate the development of microbes-based tumor-specific treatments.展开更多
In this paper,we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study.From our theoretical study,the octahedral spherical hohlraums with 6 Laser Entrance Holes(LEHs)of octa...In this paper,we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study.From our theoretical study,the octahedral spherical hohlraums with 6 Laser Entrance Holes(LEHs)of octahedral symmetry have robust high symmetry during the capsule implosion at hohlraum-to-capsule radius ratio larger than 3.7.In addition,the octahedral spherical hohlraums also have potential superiority on low backscattering without supplementary technology.We studied the laser arrangement and constraints of the octahedral spherical hohlraums,and gave a design on the laser arrangement for ignition octahedral hohlraums.As a result,the injection angle of laser beams of 50°-60°was proposed as the optimum candidate range for the octahedral spherical hohlraums.We proposed a novel octahedral spherical hohlraum with cylindrical LEHs and LEH shields,in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport.We studied on the sensitivity of the octahedral spherical hohlraums to random errors and compared the sensitivity among the octahedral spherical hohlraums,the rugby hohlraums and the cylindrical hohlraums,and the results show that the octahedral spherical hohlraums are robust to these random errors while the cylindrical hohlraums are the most sensitive.Up till to now,we have carried out three experiments on the spherical hohlraum with 2 LEHs on Shenguang(SG)laser facilities,including demonstration of improving laser transport by using the cylindrical LEHs in the spherical hohlraums,spherical hohlraum energetics on the SGIII prototype laser facility,and comparisons of laser plasma instabilities between the spherical hohlraums and the cylindrical hohlraums on the SGIII laser facility.展开更多
The formation mechanism of porous anodic oxides remains unclear till now.The classical field-assisted dissolution(FAD)theory cannot explain the relationship between the current curve and FAD reaction,and the influence...The formation mechanism of porous anodic oxides remains unclear till now.The classical field-assisted dissolution(FAD)theory cannot explain the relationship between the current curve and FAD reaction,and the influence of the electrode potential on anodization is rarely reported.The electrode potential theory,oxygen bubble model and the ionic current and electronic current theories were introduced to explain the growth of porous anodic oxides of three metals(Ti,Zr and Fe).Taking the anodization of Ti in aqueous solution containing 0.5wt% NH_(4)F as an example,the electrode potential was calculated,and the morphology of porous anodic oxides was investigated at low voltages.Results show that the growth of porous anodic oxides is determined by the ratio of the ionic current to the electronic current.During the anodization,metals are classified into two groups:one is easy to form the compact oxide layer,and the other is easy to induce oxygen releasing,thus forming oxygen bubbles.The electrolyte is also classified into two groups correspondingly:compact oxide layer-assisted electrolyte and releasing oxygen-assisted electrolyte.展开更多
Manned multi-rotor electric Vertical Takeoff and Landing(eVTOL)aircraft is prone to actuator saturation due to its weak yaw control efficiency.To address this inherent problem,a rotor cross-tilt configuration is appli...Manned multi-rotor electric Vertical Takeoff and Landing(eVTOL)aircraft is prone to actuator saturation due to its weak yaw control efficiency.To address this inherent problem,a rotor cross-tilt configuration is applied in this paper,with an optimization method proposed to improve the overall control efficiency of the vehicle.First,a flight dynamics model of a 500-kg manned multi-rotor eVTOL aircraft is established.The accuracy of the co-axial rotor model is verified using a single arm test bench,and the accuracy of the flight dynamics model is verified by the flight test data.Then,an optimization method is designed based on the flight dynamics model to calculate an optimal rotor cross-tilt mounting angle,which not only improves the yaw control efficiency,but also basically maintains the efficiency of other control channels.The ideal rotor cross-tilt mounting angle for the prototype is determined by comprehensively considering the optimal results with different payloads,forward flight speeds,and rotor mounting angle errors.Finally,the feasibility of the rotor cross-tilt mounting angle is proved by analyzing the control derivatives of the flight dynamics model,the test data of a ground three Degree-of-Freedom(3DOF)platform,and the actual flight data of the prototype.The results show that a fixed rotor cross-tilt mounting angle can achieve ideal yaw control effectiveness,improving yaw angle tracking and hold ability,increasing endurance time,and achieving good yaw control performance with different payloads and forward speeds.展开更多
Due to the rising concept of advanced air mobility(AAM),electric vertical take-off and landing(eVTOL)aircraft has become the hotspot for academic research and commercial application.This paper provides a comprehensive...Due to the rising concept of advanced air mobility(AAM),electric vertical take-off and landing(eVTOL)aircraft has become the hotspot for academic research and commercial application.This paper provides a comprehensive review of latest researches related to autonomous eVTOL.It examines key technologies involved in autonomous eVTOL,including automated flight control,sensing&perception,safety&reliability,and decision making.It also addresses the technical,regulatory,and societal challenges associated with the wholesale adoption of autonomous eVTOL into AAM.The paper concludes with a discussion of future trends and recommendations,including the importance of integration with air traffic management,urban infrastructure and human–machine interaction.It aims to be a useful resource for those involved in the research,policy,and industry of autonomous eVTOL technology.展开更多
The rapid development of concepts and technologies for civil aircraft navigation systems has put forward higher requirements for agile iteration and integrated design verification in the research and development(R&...The rapid development of concepts and technologies for civil aircraft navigation systems has put forward higher requirements for agile iteration and integrated design verification in the research and development(R&D)process.Traditional document based system engineering(DBSE)methods have gradually become inadequate.Model based system engineering(MBSE)is fully based on user′s needs and is carried out from top to bottom,in line with the concept of forward design.It is gradually being applied in the development of civil aircraft systems.This article focuses on the civil aircraft radio navigation system and proposes a complete system engineering solution based on models,from system design and development to validation.Guided by the Arcadia methodology,with Capella modeling tool,Simulink simulation tool,and system validation tool,the complete R&D process from design and development to testing and validation was achieved through model construction,code generation,and testing validation.A radio navigation station selection optimization method based on machine learning was proposed,and results had good signal quality and persistence.The verification result of Beijing⁃Shanghai flight route shows MBSE method practiced in this article can ensure the feasibility of the entire process of radio navigation system development,as well as the rationality of tuning and positioning result.By automatically generating code to form a universal functional module,an optimization method that integrates different radio navigation station selection strategies is achieved,providing new ideas for the development and design of radio navigation systems.展开更多
To increase the consistency of glioma multidisciplinary team(MDT)management across different regions and hospitals at varying levels,we have updated the Expert Consensus on MDT of Glioma in China based on the currentl...To increase the consistency of glioma multidisciplinary team(MDT)management across different regions and hospitals at varying levels,we have updated the Expert Consensus on MDT of Glioma in China based on the currently available evidence.This version has revised and updated the process-management rules and quality-control standards for a glioma MDT,providing reference and guidance for relevant clinical disciplines and physicians.All members of the Consensus Expert Group,abstract,background,and prospects can be seen in supplementaryle,http://links.lww.com/CM9/B999.展开更多
Eosinophils are terminally differentiated cells derived from hematopoietic stem cells(HSCs)in the bone marrow.Several studies have confirmed the effective roles of eosinophils in asthmatic airway pathogenesis.However,...Eosinophils are terminally differentiated cells derived from hematopoietic stem cells(HSCs)in the bone marrow.Several studies have confirmed the effective roles of eosinophils in asthmatic airway pathogenesis.However,their regulatory functions have not been well elucidated.Here,increased C-C chemokine ligand 6(CCL6)in asthmatic mice and the human orthologs CCL15 and CCL23 that are highly expressed in asthma patients are described,which are mainly derived from eosinophils.Using Cc/6 knockout mice,further studies revealed CCL6-dependent allergic airway inflammation and committed eosinophilia in the bone marrow following ovalbumin(OVA)challenge and identified a CCL6-CCR1 regulatory axis in hematopoietic stem cells(HSCs).Eosinophil differentiation and airway inflammation were remarkably decreased by the specific CCR1 antagonist BX471.Thus,the study identifies that the CCL6-CCR1 axis is involved in the crosstalk between eosinophils and HSCs during the development of allergic airway inflammation,which also reveals a potential therapeutic strategy for targeting G protein-coupled receptors(GPCRs)for future clinical treatment of asthma.展开更多
This study aims to provide the pilot with optimal control time histories for stabilization of a helicopter after releasing the slung load in aerial delivery missions. A model with 21 degrees of freedom(21-DOF) has bee...This study aims to provide the pilot with optimal control time histories for stabilization of a helicopter after releasing the slung load in aerial delivery missions. A model with 21 degrees of freedom(21-DOF) has been developed and validated for a helicopter slung load system. The control history is generated with detailed procedure based on trajectory optimization. Effects of the objective function formulation on the results are discussed and rules are obtained to assist in the objective function determination. We conclude that the pilot should first decrease and then increase the collective control and adjust the longitudinal control to stabilize the helicopter after the in-hover slung load release. The obtained control history is reasonable and helpful for safety and efficiency improvement. Effects of path constraints and the Flight Control System(FCS) are studied. More stringent path constraints will lead to longer time spent and more controls. Stronger stiffness and weaker damping from the FCS will cause milder control histories but sharper on-axis state histories.展开更多
Nitrogen(N) fertilizers in agriculture suffer losses by volatilization of N to the air, surface runoff and leaching into the soil, resulting in low N use efficiency(NUE)( 50%) and raising severe environmental pollutio...Nitrogen(N) fertilizers in agriculture suffer losses by volatilization of N to the air, surface runoff and leaching into the soil, resulting in low N use efficiency(NUE)( 50%) and raising severe environmental pollutions. Controlledrelease nitrogen fertilizers(CRNFs) can control the release of N nutrients to NUE in crop production. Different methods were used to develop new CRNFs.However, different CRNF technologies are still underdeveloped due to inadequate controlling on N releasing time and/or unsustainable diffusion. The study on the influences of CRNF processing parameters on microbial conditions are lacking when the CRNFs composed of various bio-ingredients such as biochar, composts, and biowaste. The complexity of processing methods, material biodegradability, and other physical properties make current CRNFs of questionable value in agricultural production. This research aims to develop a novel biochar-compost-based controlled-release urea fertilizer(BCRUF) to preserve microbial properties carried by the compost. The BCRUF was synthesized by pelletizing the 50:50(dry, wt/wt) mixture of biochar and compost. BCRUF was loaded with urea and then spray-coated with polylactic acid(PLA). The releasing time of two types of BCRUFs, coated and uncoated with PLA, for 80% of N release in water was up to 6 h at three different temperatures(4, 23, and 40 °C), compared to conventional urea fertilizer and commercial environmentally smart N(ESN) fertilizer. The releasing time of coated BCRUF for 80% N release in soil was up to 192 h(8 days). Fourier-transform infrared spectroscopy(FTIR) analysis revealed that no new functional groups were found in the release solution, indicating no new chemical hazards generated. The differential scanning calorimetry(DSC)tests also verified that its thermal stability could be up to 160 °C. The microbe populations in the BCRUF pellets were reduced after the pelleting and drying processes in BCRUF fabrication, but a few bacteria can endure in the air-drying process. BCRUF pellets soaked in展开更多
基金Supported by Grant No.NSFC-81272444 to Zhong LNo.PN-II-ID-PCE-2012-4-0608 Nr.48/02.09.2013 to Covasa M
文摘Colorectal cancer(CRC)is the third leading cause of cancer deaths worldwide and the fourth most common cancer diagnosed among men and women in the United States.Considering the risk factors of CRC,dietary therapy has become one of the most effective approaches in reducing CRC morbidity and mortality.The use of probiotics is increasing in popularity for both the prevention and treatment of a variety of diseases.As the most common types of microbes used as probiotics,lactic acid bacteria(LAB)are comprised of an ecologically diverse group of microorganisms united by formation of lactic acid as the primary metabolite of sugar metabolism.LAB have been successfully used in managing diarrhea,food allergies,and inflammatory bowel disease.LAB also demonstrated a host of properties in preventing colorectal cancer development by inhibiting initiation or progression through multiple pathways.In this review,we discuss recent insights into cellular and molecular mechanisms of LAB in CRC prevention including apoptosis,antioxidant DNA damages,immune responses,and epigenetics.The emerging experimental findings from clinical trials as well as the proposed mechanisms of gut microbiota in carcinogenesis will also be briefly discussed.
基金This work was supported by grants from the Strategic PriorityResearch Program of Chinese Academy of Sciences(GrantNos.XDA19090116,XDA19050302,and XDB38030400)awarded to SS,ZZ,and MLthe National Key R&D Programof China(Grant Nos.2020YFC0848900,2020YFC0847000,2016YFE0206600,and 2017YFC0907502)+5 种基金the 13th Five-yearInformatization Plan of Chinese Academy of Sciences(GrantNo.XXH13505-05)Genomics Data Center Construction ofChinese Academy of Sciences(Grant No.XXH-13514-0202)the Open Biodiversity and Health Big Data Programme ofInternational Union of Biological Sciences,International Part-nership Program of Chinese Academy of Sciences(Grant No.153F11KYSB20160008)the Professional Association of theAlliance of International Science Organizations(Grant No.ANSO-PA-2020-07)This work was also supported by KCWong Education Foundation to ZZthe YouthInnovation Promotion Association of Chinese Academy ofSciences(Grant Nos.2017141 and 2019104)awarded to SSand ML.
文摘On January 22,2020,China National Center for Bioinformation(CNCB)released the 2019 Novel Coronavirus Resource(2019nCoVR),an open-access information resource for the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).2019nCoVR features a comprehensive integration of sequence and clinical information for all publicly available SARS-CoV-2 isolates,which are manually curated with value-added annotations and quality evaluated by an automated in-house pipeline.Of particular note,2019nCoVR offers systematic analyses to generate a dynamic landscape of SARS-CoV-2 genomic variations at a global scale.It provides all identified variants and their detailed statistics for each virus isolate,and congregates the quality score,functional annotation,and population frequency for each variant.Spatiotemporal change for each variant can be visualized and historical viral haplotype network maps for the course of the outbreak are also generated based on all complete and high-quality genomes available.Moreover,2019nCoVR provides a full collection of SARS-CoV-2 relevant literature on the coronavirus disease 2019(COVID-19),including published papers from PubMed as well as preprints from services such as bioRxiv and medRxiv through Europe PMC.Furthermore,by linking with relevant databases in CNCB,2019nCoVR offers data submission services for raw sequence reads and assembled genomes,and data sharing with NCBI.Collectively,SARS-CoV-2 is updated daily to collect the latest information on genome sequences,variants,haplotypes,and literature for a timely reflection,making 2019nCoVR a valuable resource for the global research community.2019nCoVR is accessible at https://bigd.big.ac.cn/ncov/.
文摘Social media websites allow users to exchange short texts such as tweets via microblogs and user status in friendship networks. Their limited length, pervasive abbrevi- ations, and coined acronyms and words exacerbate the prob- lems of synonymy and polysemy, and bring about new chal- lenges to data mining applications such as text clustering and classification. To address these issues, we dissect some poten- tial causes and devise an efficient approach that enriches data representation by employing machine translation to increase the number of features from different languages. Then we propose a novel framework which performs multi-language knowledge integration and feature reduction simultaneously through matrix factorization techniques. The proposed ap- proach is evaluated extensively in terms of effectiveness on two social media datasets from Facebook and Twitter. With its significant performance improvement, we further investi- gate potential factors that contribute to the improved perfor- mance.
基金supported by the National Basic Research Program of China(2011CB710703)the National Natural Science Foundation of China(51306048,51210011)
文摘The design, construction and test of an Organic Rankine Cycle(ORC) with R123 as the working fluid were performed. A scroll expander was integrated in the system.The conductive oil with its temperature of 150 °C was used to simulate the low-grade heat source. An AC dynamometer unit measured the expander shaft torque, rotating speed and shaft power. The experiments were conducted in two operating modes: the constant mass flow rate and the constant shaft torque. Under the constant mass flow rate operating mode, the stepped increase of the shaft torque increased the expansion ratios of the expander and decreased the vapor superheats at the expander inlet. Thus,the shaft power and thermal efficiency were increased.Alternatively, the constant shaft torque operating mode involved two different regions, interfaced at the pumping frequency of 9 Hz. By the increase of the mass flow rates,the vapor superheats at the expander inlet was decreased and the shaft power was increased, but the ORC thermal efficiencies were slightly decreased. Both operating modes yielded the saturation shaft powers that were the maximum values one could use. It was found that the measured shaft powers and ORC thermal efficiencies were lower than the enthalpy determined values based on the fluid pressures and temperatures at the expander inlet and outlet. The maximum measured shaft power and thermal efficiency were 2.63 kW and 5.31 %, compared with the enthalpy determined values of 3.87 kW and 9.46 %, respectively.
基金supported by the National Key R&D Program of China(Nos.2017YFC0212802 and 2017YFC0212004)the support of MOST project(No.2017YFC0212001)for the collaboration。
文摘We present the continuously measurements of volatile organic compounds(VOCs)at a receptor site(Wan Qing Sha,WQS)in the Pearl River Delta(PRD)region from September to November of 2017.The average mixing ratios of total VOCs(TVOCs)was 36.3±27.9 ppbv with the dominant contribution from alkanes(55.5%),followed by aromatics(33.3%).The diurnal variation of TVOCs showed a strong photochemical consumption during daytime,resulting in the formation of ozone(O_(3)).Five VOC sources were resolved by the positive matrix factorization(PMF)model,including solvent usage(28.6%),liquid petroleum gas(LPG)usage(24.4%),vehicle exhaust(21.0%),industrial emissions(13.2%)and gasoline evaporation(12.9%).The regional transport air masses from the upwind cities of south China can result in the elevated concentrations of TVOCs.Low ratios of TVOCs/NO_(x)(1.53±0.88)suggested that the O_(3) formation regime at WQS site was VOC-limited,which also confirmed by a photochemical box model with the master chemical mechanism(PBM-MCM).Furthermore,the observation on high-O_(3) episode days revealed that frequent O_(3) outbreaks at WQS were mainly caused by the regional transport of anthropogenic VOCs especially for aromatics and the subsequent photochemical reactions.This study provides valuable information for policymakers to propose the effective control strategies on photochemical pollution in a regional perspective.
基金supported by the National Natural Science Foundation of China (No. 11672128)
文摘An augmented flight dynamics model is developed to extend the existing flight dynamics model of tilt-rotor aircraft for optimal landing procedure analysis in the event of one engine failure.Compared with the existing flight dynamics model, the augmented model involves with more pilot control information in cockpit and is validated against the flight test data. Based on the augmented flight dynamics model, the optimal landing procedure of XV-15 tilt-rotor aircraft after one engine failure is formulated into a Nonlinear Optimal Control Problem(NOCP), solved by collocation and numerical optimization method. The time histories of pilot controls in cockpit during the optimal landing procedure are obtained for the evaluation of pilot workload. An evaluation method which can synthetically quantify the pilot workload in time and frequency domains is proposed with metrics of aggressiveness and cutoff frequencies of pilot controls. The scale of the pilot workload is compared with those of the shipboard landing procedures, bob-up/bob-down and dash/quickstop maneuvers of UH-60 helicopter. The results show that the aggressiveness of pilot collective and longitudinal controls for the tilt-rotor aircraft optimal landing procedure after one engine failure are higher than those for UH-60 helicopter shipboard landing procedures up to the condition of sea state 4, while the pilot cutoff frequency of collective control is lower than that of the bob-up/bob-down maneuver but the pilot cutoff frequency of longitudinal control is higher than that of the dash/quick-stop maneuver. The evaluated pilot workload level is between Cooper–Harper HQR Level 2 and Level 3.
基金Supported by National Key Research&Development Program of China Research on the Development and Evaluation of International Standards of Traditional Chinese Medicine(No.2019YFC17120002019YFC1712005+2 种基金2019YFC1712003)National Science and Technology Major Project"The Belt and Road"Popularization and Application of Traditional Chinese Medicine Clinical Diagnosis and Treatment Project for Infectious Diseases(No.2018ZX10101001-005-0032018ZX10101001-005-004)。
文摘OBJECTIVE:To summarize the evidence from Traditional Chinese Medicine(TCM)practice in the treatment of coronavirus disease 2019(COVID-19)and provide timely clinical practice guidance.METHODS:The guidelines were developed in accordance with the World Health Organization rapid guideline process.The evidence on TCM for COVID-19 from published guidelines,direct and indirect published clinical evidence,first hand clinical data,and expert experience and consensus were collected.The grading of recommendations assessment,development and evaluation(GRADE)method was used to grade the evidence and make the recommendations.RESULTS:Based on the available evidence,the guidelines recommended 17 Chinese medicines for COVID-19:2 Chinese herbal granules,7 Chinese patent medicines,and 8 Chinese herbal injections.CONCLUSION:As the literature search was conducted on March,any subsequent versions of these guidelines require an up-to-date literature review.We hope that the evidence summary in these guidelines will be helpful in global efforts to address COVID-19.
文摘A novel thermal biosensor based on enzyme reaction for pesticides detection has been developed. This biosensor is a flow injection analysis system and consists of two channels with enzyme reaction column and identical reference column, which is set for eliminating the unspecific heat. The enzyme reaction takes place in the enzyme reaction column at a constant temperature(40℃) realized by a thermoelectric thermostat. Thermosensor based on the thermoelectric module containing 127 serial BiTe-thermocouples is used to monitor the temperature difference between two effluents from enzyme reaction column and reference column. The ability of this biosensor to detect pesticides is demonstrated by the decreased degree of the hydrolytic heat in two types of thermosensor mode. The hydrolytic reaction is inhibited by 36% at 1 mg/L DDVP and 50 % at 10 mg/L DDVP when cell-typed thermosensor is used. The percent inhibition is 30% at 1 mg/L DDVP and 42% at 10 mg/L DDVP in tube-typed thermosensor mode. The detection for real sample shows that this biosensor can be used for detection of organophosphate pesticides residue.
基金This work was supported by grants from National Natural Science Foundation of China(No.82204281)Natural Science Foundation of Chongqing,China(cstc2021jcyj-msxmX0544)+3 种基金Chongqing Science Fund for Distinguished Young Scholars(CSTB2023NSCQ-JQX0021,China)Key project for clinical innovation of Army Medical University(CX2019LC107,China)Innovative Research Group at Higher Educational Institutions in Chongqing(CXQT20006,China)Doctoral Through Train Scientific Research Project of Chongqing(CSTB2022BSXMJCX0004,China).
文摘Intratumoral microbiota has become research hotspots,and emerges as a non-negligent new component of tumor microenvironments(TME),due to its powerful infuence on tumor initiation,metas-tasis,immunosurveillance and prognosis despite in low-biomass.The accumulations of microbes,and their related components and metabolites within tumor tissues,endow TME with additional pluralistic features which are distinct from the conventional one.Therefore,it's definitely necessary to comprehen-sively delineate the sophisticated landscapes of tumor microbe microenvironment,as well as their func-tions and related underlying mechanisms.Herein,in this review,we focused on the fields of tumor microbe microenvironment,including the heterogeneity of intratumor microbiota in different types of tu-mors,the controversial roles of intratumoral microbiota,the basic features of tumor microbe microenvi-ronment(i.e.,pathogen-associated molecular patterns(PAMPs),typical microbial metabolites,autophagy,infammation,multi-faceted immunomodulation and chemoresistance),as well as the multi-disciplinary approach-based intervention of tumor microbiome for cancer therapy by applying wild-type or engineered live microbes,microbiota metabolites,antibiotics,synthetic biology and rationally de-signed biomaterials.We hope our work will provide valuable insight to deeply understand the interplay of cancer-immune-microbial,and facilitate the development of microbes-based tumor-specific treatments.
基金supported by the National Fundamental Research Program of China(Contact No.11475033 and 11405011)CAEP(Contact No.2013A0102002).
文摘In this paper,we give a review of our theoretical and experimental progress in octahedral spherical hohlraum study.From our theoretical study,the octahedral spherical hohlraums with 6 Laser Entrance Holes(LEHs)of octahedral symmetry have robust high symmetry during the capsule implosion at hohlraum-to-capsule radius ratio larger than 3.7.In addition,the octahedral spherical hohlraums also have potential superiority on low backscattering without supplementary technology.We studied the laser arrangement and constraints of the octahedral spherical hohlraums,and gave a design on the laser arrangement for ignition octahedral hohlraums.As a result,the injection angle of laser beams of 50°-60°was proposed as the optimum candidate range for the octahedral spherical hohlraums.We proposed a novel octahedral spherical hohlraum with cylindrical LEHs and LEH shields,in order to increase the laser coupling efficiency and improve the capsule symmetry and to mitigate the influence of the wall blowoff on laser transport.We studied on the sensitivity of the octahedral spherical hohlraums to random errors and compared the sensitivity among the octahedral spherical hohlraums,the rugby hohlraums and the cylindrical hohlraums,and the results show that the octahedral spherical hohlraums are robust to these random errors while the cylindrical hohlraums are the most sensitive.Up till to now,we have carried out three experiments on the spherical hohlraum with 2 LEHs on Shenguang(SG)laser facilities,including demonstration of improving laser transport by using the cylindrical LEHs in the spherical hohlraums,spherical hohlraum energetics on the SGIII prototype laser facility,and comparisons of laser plasma instabilities between the spherical hohlraums and the cylindrical hohlraums on the SGIII laser facility.
基金National Natural Science Foundation of China(51577093,51777097)Natural Science Foundation of Jiangsu Higher Education Institutions(20KJB430040)+1 种基金Changzhou Science&Technology Program(CJ20200026)Qing Lan Project in Colleges and Universities of Jiangsu Province。
文摘The formation mechanism of porous anodic oxides remains unclear till now.The classical field-assisted dissolution(FAD)theory cannot explain the relationship between the current curve and FAD reaction,and the influence of the electrode potential on anodization is rarely reported.The electrode potential theory,oxygen bubble model and the ionic current and electronic current theories were introduced to explain the growth of porous anodic oxides of three metals(Ti,Zr and Fe).Taking the anodization of Ti in aqueous solution containing 0.5wt% NH_(4)F as an example,the electrode potential was calculated,and the morphology of porous anodic oxides was investigated at low voltages.Results show that the growth of porous anodic oxides is determined by the ratio of the ionic current to the electronic current.During the anodization,metals are classified into two groups:one is easy to form the compact oxide layer,and the other is easy to induce oxygen releasing,thus forming oxygen bubbles.The electrolyte is also classified into two groups correspondingly:compact oxide layer-assisted electrolyte and releasing oxygen-assisted electrolyte.
基金co-supported by the National Natural Science Foundation of China(Nos.12202406,11672128)。
文摘Manned multi-rotor electric Vertical Takeoff and Landing(eVTOL)aircraft is prone to actuator saturation due to its weak yaw control efficiency.To address this inherent problem,a rotor cross-tilt configuration is applied in this paper,with an optimization method proposed to improve the overall control efficiency of the vehicle.First,a flight dynamics model of a 500-kg manned multi-rotor eVTOL aircraft is established.The accuracy of the co-axial rotor model is verified using a single arm test bench,and the accuracy of the flight dynamics model is verified by the flight test data.Then,an optimization method is designed based on the flight dynamics model to calculate an optimal rotor cross-tilt mounting angle,which not only improves the yaw control efficiency,but also basically maintains the efficiency of other control channels.The ideal rotor cross-tilt mounting angle for the prototype is determined by comprehensively considering the optimal results with different payloads,forward flight speeds,and rotor mounting angle errors.Finally,the feasibility of the rotor cross-tilt mounting angle is proved by analyzing the control derivatives of the flight dynamics model,the test data of a ground three Degree-of-Freedom(3DOF)platform,and the actual flight data of the prototype.The results show that a fixed rotor cross-tilt mounting angle can achieve ideal yaw control effectiveness,improving yaw angle tracking and hold ability,increasing endurance time,and achieving good yaw control performance with different payloads and forward speeds.
基金This work is supported by NSFC Project(Grant No.62103383,62201518,12202406)NFS Project of Zhejiang Province(Grant No.LQ20F030008).
文摘Due to the rising concept of advanced air mobility(AAM),electric vertical take-off and landing(eVTOL)aircraft has become the hotspot for academic research and commercial application.This paper provides a comprehensive review of latest researches related to autonomous eVTOL.It examines key technologies involved in autonomous eVTOL,including automated flight control,sensing&perception,safety&reliability,and decision making.It also addresses the technical,regulatory,and societal challenges associated with the wholesale adoption of autonomous eVTOL into AAM.The paper concludes with a discussion of future trends and recommendations,including the importance of integration with air traffic management,urban infrastructure and human–machine interaction.It aims to be a useful resource for those involved in the research,policy,and industry of autonomous eVTOL technology.
文摘The rapid development of concepts and technologies for civil aircraft navigation systems has put forward higher requirements for agile iteration and integrated design verification in the research and development(R&D)process.Traditional document based system engineering(DBSE)methods have gradually become inadequate.Model based system engineering(MBSE)is fully based on user′s needs and is carried out from top to bottom,in line with the concept of forward design.It is gradually being applied in the development of civil aircraft systems.This article focuses on the civil aircraft radio navigation system and proposes a complete system engineering solution based on models,from system design and development to validation.Guided by the Arcadia methodology,with Capella modeling tool,Simulink simulation tool,and system validation tool,the complete R&D process from design and development to testing and validation was achieved through model construction,code generation,and testing validation.A radio navigation station selection optimization method based on machine learning was proposed,and results had good signal quality and persistence.The verification result of Beijing⁃Shanghai flight route shows MBSE method practiced in this article can ensure the feasibility of the entire process of radio navigation system development,as well as the rationality of tuning and positioning result.By automatically generating code to form a universal functional module,an optimization method that integrates different radio navigation station selection strategies is achieved,providing new ideas for the development and design of radio navigation systems.
基金Shanghai Hospital Development Center under Project(No.SHDC22021208)
文摘To increase the consistency of glioma multidisciplinary team(MDT)management across different regions and hospitals at varying levels,we have updated the Expert Consensus on MDT of Glioma in China based on the currently available evidence.This version has revised and updated the process-management rules and quality-control standards for a glioma MDT,providing reference and guidance for relevant clinical disciplines and physicians.All members of the Consensus Expert Group,abstract,background,and prospects can be seen in supplementaryle,http://links.lww.com/CM9/B999.
基金supported by the National Natural Science Foundation of China(81930003,81420108001,81870007,81920108001)the Major Research Plan(91642202).
文摘Eosinophils are terminally differentiated cells derived from hematopoietic stem cells(HSCs)in the bone marrow.Several studies have confirmed the effective roles of eosinophils in asthmatic airway pathogenesis.However,their regulatory functions have not been well elucidated.Here,increased C-C chemokine ligand 6(CCL6)in asthmatic mice and the human orthologs CCL15 and CCL23 that are highly expressed in asthma patients are described,which are mainly derived from eosinophils.Using Cc/6 knockout mice,further studies revealed CCL6-dependent allergic airway inflammation and committed eosinophilia in the bone marrow following ovalbumin(OVA)challenge and identified a CCL6-CCR1 regulatory axis in hematopoietic stem cells(HSCs).Eosinophil differentiation and airway inflammation were remarkably decreased by the specific CCR1 antagonist BX471.Thus,the study identifies that the CCL6-CCR1 axis is involved in the crosstalk between eosinophils and HSCs during the development of allergic airway inflammation,which also reveals a potential therapeutic strategy for targeting G protein-coupled receptors(GPCRs)for future clinical treatment of asthma.
基金supported by the National Natural Science Foundation of China (Nos. 11672128)A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘This study aims to provide the pilot with optimal control time histories for stabilization of a helicopter after releasing the slung load in aerial delivery missions. A model with 21 degrees of freedom(21-DOF) has been developed and validated for a helicopter slung load system. The control history is generated with detailed procedure based on trajectory optimization. Effects of the objective function formulation on the results are discussed and rules are obtained to assist in the objective function determination. We conclude that the pilot should first decrease and then increase the collective control and adjust the longitudinal control to stabilize the helicopter after the in-hover slung load release. The obtained control history is reasonable and helpful for safety and efficiency improvement. Effects of path constraints and the Flight Control System(FCS) are studied. More stringent path constraints will lead to longer time spent and more controls. Stronger stiffness and weaker damping from the FCS will cause milder control histories but sharper on-axis state histories.
基金funding supports from the South Dakota Governor’s Office of Economic Development (POC2020-04)the USDA NIFA through the North Central Regional Sun Grant Center, and Hatch Projects (3AR652, 3AR689, and 3AH658) of the South Dakota Agricultural Experiment Station。
文摘Nitrogen(N) fertilizers in agriculture suffer losses by volatilization of N to the air, surface runoff and leaching into the soil, resulting in low N use efficiency(NUE)( 50%) and raising severe environmental pollutions. Controlledrelease nitrogen fertilizers(CRNFs) can control the release of N nutrients to NUE in crop production. Different methods were used to develop new CRNFs.However, different CRNF technologies are still underdeveloped due to inadequate controlling on N releasing time and/or unsustainable diffusion. The study on the influences of CRNF processing parameters on microbial conditions are lacking when the CRNFs composed of various bio-ingredients such as biochar, composts, and biowaste. The complexity of processing methods, material biodegradability, and other physical properties make current CRNFs of questionable value in agricultural production. This research aims to develop a novel biochar-compost-based controlled-release urea fertilizer(BCRUF) to preserve microbial properties carried by the compost. The BCRUF was synthesized by pelletizing the 50:50(dry, wt/wt) mixture of biochar and compost. BCRUF was loaded with urea and then spray-coated with polylactic acid(PLA). The releasing time of two types of BCRUFs, coated and uncoated with PLA, for 80% of N release in water was up to 6 h at three different temperatures(4, 23, and 40 °C), compared to conventional urea fertilizer and commercial environmentally smart N(ESN) fertilizer. The releasing time of coated BCRUF for 80% N release in soil was up to 192 h(8 days). Fourier-transform infrared spectroscopy(FTIR) analysis revealed that no new functional groups were found in the release solution, indicating no new chemical hazards generated. The differential scanning calorimetry(DSC)tests also verified that its thermal stability could be up to 160 °C. The microbe populations in the BCRUF pellets were reduced after the pelleting and drying processes in BCRUF fabrication, but a few bacteria can endure in the air-drying process. BCRUF pellets soaked in
