Objective: Digital healthcare is rapidly becoming a new model for medical development in the information society with its convenience, and personalization, and a research boom in digital healthcare has formed at home ...Objective: Digital healthcare is rapidly becoming a new model for medical development in the information society with its convenience, and personalization, and a research boom in digital healthcare has formed at home and abroad in recent years. The purpose of this study is to conduct a bibliometric analysis of the field of digital healthcare and to understand the research background and development trend in this field. Methods: A visual analysis of authors, institutions, journals and keywords was conducted using CiteSpace 5.8R3 software. Results: A total of 1646 digital healthcare-related retrieved from WoS and PubMed studies. There was an overall upward trend in the number of digital healthcare publications, with the highest number of publications in 2021 (290). The author AZIZ SHEIKH is ranked first in the number of published articles (13), while King Saud University (23) is the research institution with the most articles. Keyword clustering showed that the first cluster was data security;the common high frequency keywords that appeared were systems (85), artificial intelligence (82), mobile health (70), internet (61), and technology (57). Digital healthcare, artificial intelligence, healthcare services, machine learning and deep learning are the hotspot of current research. Conclusion: This paper summarises the state of the art in digital healthcare research. Using statistical analysis and network visualisation, it highlights the background, trends and hot topics in digital healthcare research. The paper finds that there is significant potential for artificial intelligence to help bridge the digital divide and reduce health inequalities. To understand the current state, hot trends and future directions of digital healthcare research, this paper can serve as a reference. .展开更多
This paper analyzes the current situation of agricultural credit policy in Dingxi City,and further studies the problems in the implementation of credit policy in Dingxi City,and puts forward strategies and suggestions...This paper analyzes the current situation of agricultural credit policy in Dingxi City,and further studies the problems in the implementation of credit policy in Dingxi City,and puts forward strategies and suggestions according to these problems.展开更多
<strong>Background: </strong>In less than a year, COVID-19 has swept the world and continued, too, seriously threatening the safety of all mankind, and caused great social panic and global economic and fin...<strong>Background: </strong>In less than a year, COVID-19 has swept the world and continued, too, seriously threatening the safety of all mankind, and caused great social panic and global economic and financial crisis. At the beginning, the epidemic was first diagnosed in China and the epidemic was severe. Under the strong command of the highest level of the Chinese government, the whole Chinese people united as one, and achieved initial results in the struggle against COVID-19 with scientific prevention and control. <strong>Objective:</strong> Summarizing China’s experience and lessons in combating the epidemic is undoubtedly very beneficial to the people of the world in jointly combating the impact of the COVID-19 epidemic. <strong>Measures:</strong> The article shows the imminent Chinese experience in controlling the spread of SARS-CoV-2. It details the lines of action and the measures taken to control this epidemic in the country where the population is quite large. The most important experience is: strong organizational leadership, enhanced cooperation with the WHO, the establishment of a national anti-epidemic headquarters, responsible for the command and control of human, financial and material resources throughout the country, and local officials at all levels in the front line of the epidemic, Heart to heart with the people, breathing together and sharing a common destiny. Prevention is the first, prevention and treatment are combined. All measures were taken to control the source of infection, cut off the spread and protect susceptible people. <strong>Conclusion: </strong>As long as the people of the world unite, make scientific decisions and learn from the successful experience of countries around the world, especially the China’s experience, combine the national conditions of each country, and use the wisdom of all man-kind to deal with the common enemy SARS-CoV-2 and COVID-19, we can definitely win this people’s war against the disease.展开更多
In Ga As is an important bandgap-variable ternary semiconductor which has wide applications in electronics and optoelectronics. In this work, single-crystal In Ga As nanowires were synthesized by a chemical vapor depo...In Ga As is an important bandgap-variable ternary semiconductor which has wide applications in electronics and optoelectronics. In this work, single-crystal In Ga As nanowires were synthesized by a chemical vapor deposition method.Photoluminescence measurements indicate the In Ga As nanowires have strong light emission in near-infrared region. For the first time, photodetector based on as-grown In Ga As nanowires was also constructed. It shows good light response over a broad spectral range in infrared region with responsivity of 6.5×10~3 AW^(-1) and external quantum efficiency of 5.04×10~5%. This photodetector may have potential applications in integrated optoelectronic devices and systems.展开更多
Mix-dimensional van der Waals heterostructures(vdWHs)have inspired worldwide interests and efforts in the field of ad-vanced electronics and optoelectronics.The fundamental understanding of interfacial charge transfer...Mix-dimensional van der Waals heterostructures(vdWHs)have inspired worldwide interests and efforts in the field of ad-vanced electronics and optoelectronics.The fundamental understanding of interfacial charge transfer is of vital import-ance for guiding the design of functional optoelectronic applications.In this work,type-Ⅱ0D-2D CdSe/ZnS quantum dots/MoS_(2)vdWHs are designed to study the light-triggered interfacial charge behaviors and enhanced optoelectronic performances.From spectral measurements in both steady and transient states,the phenomena of suppressed photolu-minescence(PL)emissions,shifted Raman signals and changed PL lifetimes provide strong evidences of efficient charge transfer at the 0D-2D interface.A series of spectral evolutions of heterostructures with various QDs overlapping concentrations at different laser powers are analyzed in details,which clarifies the dynamic competition between exciton and trion during an efficient doping of 3.9×10^(13)cm^(−2).The enhanced photoresponses(1.57×10^(4)A·W^(-1))and detectivities(2.86×10^(11)Jones)in 0D/2D phototransistors further demonstrate that the light-induced charge transfer is still a feasible way to optimize the performance of optoelectronic devices.These results are expected to inspire the basic understand-ing of interfacial physics at 0D/2D interfaces,and shed the light on promoting the development of mixed-dimensional op-toelectronic devices in the near future.展开更多
In this work, we synthesized high-quality In As nanowires by a convenient chemical vapor deposition method,and developed a simple laser heating method to measure the thermal conductivity of a single In As nanowire in ...In this work, we synthesized high-quality In As nanowires by a convenient chemical vapor deposition method,and developed a simple laser heating method to measure the thermal conductivity of a single In As nanowire in air. During the measurement, a focused laser was used to heat one end of a freely suspended nanowire, with its other end embedded into a carbon conductive adhesive. In order to obtain the thermal conductivity of In As nanowires, the heat loss in the heat transfer process was estimated, which includes the heat loss through air conduction, the heat convection, and the radiation loss. The absorption ratio of the laser power in the In As nanowire was calculated. The result shows that the thermal conductivity of In As nanowires monotonically increases from 6.4 W m-1K-1to 10.5 W m-1K-1with diameters increasing from 100 nm to 190 nm, which is ascribed to the enhanced phonon-boundary scattering.展开更多
Purpose:We aimed to compare treatment efficacy,safety and material cost between tissue gel and coil regarding variceal embolization during transjugular intrahepatic portosystemic shunt(TIPS).Materials&Methods:This...Purpose:We aimed to compare treatment efficacy,safety and material cost between tissue gel and coil regarding variceal embolization during transjugular intrahepatic portosystemic shunt(TIPS).Materials&Methods:This retrospective study including cirrhotic patients with variceal bleeding treated with TIPS combined with variceal embolization between January 2016 and August 2017.Patients were divided into three groups according to embolic agents used in variceal embolization:tissue gel group(Group A),combination group(Group B),and coil group(Group C).The primary endpoint was 1-year rebleeding rate after TIPS creation.The secondary endpoints included shunt dysfunction,overt hepatic encephalopathy,liver function,and embolic agents-related expense.Results:A total of 60 patients(30,10,and 20 in Group A,B,and C)were included.Variceal rebleeding occurred in3(10%),0(0%),and 4(20%)patients within one year after TIPS creation in Group A,B,and C,respectively.Stent dysfunction occurred in 2(3.3%)patients and 9(15.0%)patients experienced overt hepatic encephalopathy.No significant differences were observed between three groups regarding primary and secondary endpoints except embolic agents-related expense,with a significantly lower cost in Group A when compared to the other two groups.Stent dysfunction occurred in two patients,with one patient in Group A developed acute occlusion caused by thrombus and another patient in Group C underwent stent stenosis during follow-up.Conclusions:Compares to coil alone or combines with coil,tissue gel has similar treatment efficacy and safety,but with significantly lower cost for variceal bleeding during TIPS.展开更多
Objectives:To present a case series of modified transjugular intrahepatic portosystemic shunts(TIPS) and percutaneous transhepatic intrahepatic portosystemic shunts(PTIPS) in cirrhotic patients with variceal bleeding(...Objectives:To present a case series of modified transjugular intrahepatic portosystemic shunts(TIPS) and percutaneous transhepatic intrahepatic portosystemic shunts(PTIPS) in cirrhotic patients with variceal bleeding(VB).In addition,the scientific literature pertaining to PTIPS was reviewed.Methods:This retrospective clinical case series included six cirrhotic patients with VB who were treated with PTIPS after the failure of endoscopic band ligation or endoscopic injection sclerotherapy combined with vasoactive drugs.The treatment was conducted between January 2017 and June 2019 at a single institution.Three patients suffered from severe atrophy of the right or left lobar of the liver as well as the main right or left branch of the portal vein.The remaining three patients showed severe atrophy of the whole liver and portal vein,resulting in widening of the liver fissure.A paired t-test was used to compare the changes in portal pressure gradient between before and after the PTIPS operation.The rebleeding rate,treatment efficacy,complications,and technical success rate were all assessed during follow-up.Results:All six PTIPS procedures were performed successfully,with no severe procedural-related complications observed.None of the patients experienced VB during a mean follow-up of 22.8(range,18.0-28.0) months.The mean portosystemic pressure gradient decreased from 28.3 ± 4.3 mmHg pre-procedure to 12.3 ± 2.6 mmHg immediately post-procedure(P <0.001).At follow-up,one patient was found to have developed grade 2 hepatic encephalopathy thrice during the first year,according to the West Haven criteria.However,this was resolved following medical treatment.Conclusions:When the patient’s portal venous anatomy is unconducive to the performance of TIPS using the transjugular approach,PTIPS can be considered as a safe,effective complementary surgical approach for patients with VB.展开更多
Highly efficient and robust electrocatalysts have been in urgent demand for oxygen evolution reaction(OER).For this purpose,high-cost carbon materials,such as graphene and carbon nanotubes,have been used as supports t...Highly efficient and robust electrocatalysts have been in urgent demand for oxygen evolution reaction(OER).For this purpose,high-cost carbon materials,such as graphene and carbon nanotubes,have been used as supports to metal oxides to enhance their catalytic activity.We report here a new Co_(3)O_(4)-based catalyst with nitrogen-doped porous carbon material as the support,prepared by pyrolysis of porous polyurea(PU) with Co(NO_(3))_(2)immobilized on its surface.To this end,PU was first synthesized,without any additive,through a very simple one-step precipitation polymerization of toluene diisocyanate in a binary mixture of H2O-acetone at room temperature.By immersing PU in an aqueous solution of Co(NO_(3))_(2)at room temperature,a cobalt coordinated polymer composite,Co(NO_(3))_(2)/PU,was obtained,which was heated at 500℃ in air for 2 h to get a hybrid,Co_(3)O_(4)/NC,consisting of Co_(3)O_(4)nanocrystals and sp2-hybridized N-doped carbon.Using this Co_(3)O_(4)/NC as a catalyst in OER,a current density of10 mA·cm^(-2)was readily achieved with a low overpotential of 293 mV with a Tafel slope of87 mV·dec^(-1),a high catalytic activity.This high performance was well retained after 1000 recycled uses,demonstrating its good durability.This work provides therefore a facile yet simple pathway to fabrication of a new transition metal oxides-based N-doped carbon catalyst for OER with high performance.展开更多
The development of agriculture with plateau characteristics is a market-oriented strategic choice,made by Yunnan Province,of agricultural economy with regional characteristics,on the basis of resources and location ad...The development of agriculture with plateau characteristics is a market-oriented strategic choice,made by Yunnan Province,of agricultural economy with regional characteristics,on the basis of resources and location advantages,as well as geographical division of the national economy. The characteristic agribusiness is an important carrier for building a new agricultural management system with plateau characteristics,and also a key way to promote characteristic agricultural industrialization. In this paper,with 26 agribusinesses with plateau characteristics in Yunnan Province as samples,we establish the competitiveness evaluation system for the agribusiness with plateau characteristics,and use the operating data( 2012-2014) and AHP to calculate and the sample business competitiveness index and sort these businesses. Finally,we make a comprehensive analysis on the competitiveness of sample agribusinesses with plateau characteristics in Yunnan Province,in order to provide decision-making basis for promotion of the competitiveness of the agribusiness with plateau characteristics.展开更多
To the Editor:With an aging global population,the incidences of community-acquired pneumonia(CAP)and chronic obstructive pulmonary disease(COPD)have signicantly increased.[1]Previous studies have conrmed that COPD and...To the Editor:With an aging global population,the incidences of community-acquired pneumonia(CAP)and chronic obstructive pulmonary disease(COPD)have signicantly increased.[1]Previous studies have conrmed that COPD and asthma are independently associated with the prevalence of CAP.The use of inhaled corticosteroid(ICS),the cornerstone of treatment for asthma,COPD with frequent acute exacerbations,and asthma-COPD overlap(ACO)may induce changes in the local lung microbiome and abnormal lung immunity,ultimately,causing a signicantly increased risk of pneumonia.However,in cases of pneumonia,the effect of the use of ICS on CAP mortality remains controversial.While data from one study favored the prior use of ICS,which was associated with a signicantly lower short-term mortality rate,[2]other studies have identied no impact on mortality.To date,data on the impact of the use of ICS on mortality,prehospitalization or during hospitalization,are scarce,particularly in the older population.Therefore,this multicenter,retrospective study explored the association between the use of ICS during hospitalization and short-term mortality in older patients with CAP and those with chronic pulmonary disease(CPD).展开更多
E-beam lithography is a powerful tool for generating nanostructures and fabricating nanodevices with fine features approaching a few nanometers in size.However,alternative approaches to conventional spin coating and d...E-beam lithography is a powerful tool for generating nanostructures and fabricating nanodevices with fine features approaching a few nanometers in size.However,alternative approaches to conventional spin coating and development processes are required to optimize the lithography procedure on irregular surfaces.In this review,we summarize the state of the art in nanofabrication on irregular substrates using e-beam lithography.To overcome these challenges,unconventional methods have been developed.For instance,polymeric and nonpolymeric materials can be sprayed or evaporated to form uniform layers of electron-sensitive materials on irregular substrates.Moreover,chemical bonds can be applied to help form polymer brushes or self-assembled monolayers on these surfaces.In addition,thermal oxides can serve as resists,as the etching rate in solution changes after e-beam exposure.Furthermore,e-beam lithography tools can be combined with cryostages,evaporation systems,and metal deposition chambers for sample development and lift-off while maintaining low temperatures.Metallic nanopyramids can be fabricated on an AFM tip by utilizing ice as a positive resistor.Additionally,Ti/Au caps can be patterned around a carbon nanotube.Moreover,3D nanostructures can be formed on irregular surfaces by exposing layers of anisole on organic ice surfaces with a focused e-beam.These advances in e-beam lithography on irregular substrates,including uniform film coating,instrumentation improvement,and new pattern transferring method development,substantially extend its capabilities in the fabrication and application of nanoscale structures.展开更多
Heavy metals(HMs)represent pervasive and highly toxic environmental pollutants,known for their long latency periods and high toxicity levels,which pose significant challenges for their removal and degradation.Therefor...Heavy metals(HMs)represent pervasive and highly toxic environmental pollutants,known for their long latency periods and high toxicity levels,which pose significant challenges for their removal and degradation.Therefore,the removal of heavy metals from the environment is crucial to ensure the water safety.Biochar materials,known for their intricate pore structures and abundant oxygen-containing functional groups,are frequently harnessed for their effectiveness in mitigating heavy metal contamination.However,conventional tests for optimizing biochar synthesis and assessing their heavy metal adsorption capabilities can be both costly and tedious.To address this challenge,this paper proposes a data-driven machine learning(ML)approach to identify the optimal biochar preparation and adsorption reaction conditions,with the ultimate goal of maximizing their adsorption capacity.By utilizing a data set comprising 476 instances of heavy metal absorption by biochar,seven classical integrated models and one stacking model were trained to rapidly predict the efficiency of heavy metal adsorption by biochar.These predictions were based on diverse physicochemical properties of biochar and the specific adsorption reaction conditions.The results demonstrate that the stacking model,which integrates multiple algorithms,allows for training with fewer samples to achieve higher prediction accuracy and improved generalization ability.展开更多
Supercapacitors have garnered significant attention due to their superior power density,excellent cycle stability,and fast charge/discharge rates.The properties of the electrode materials determine the charge storage ...Supercapacitors have garnered significant attention due to their superior power density,excellent cycle stability,and fast charge/discharge rates.The properties of the electrode materials determine the charge storage performance of supercapacitors.Covalent organic frameworks(COFs)are a novel class of crystalline porous polymer materials with uniform nanoscale pores,large specific surface areas,and tunable redox-active groups within the framework,which can be tuned to suit specific applications.They have flexible molecular designs and synthetic strategies,demonstrating their strong application potential in the field of energy storage.Most COFs exhibit poor inherent conductivity and low utilization of active sites,resulting in incomplete electrochemical performance.Hybrid systems can be developed by incorporating redox-active groups,hydrogen bonding,or combining COFs with other materials to improve the energy storage performance of COFs materials.In this review article,the background of COFs is summarized,including a brief introduction,design strategy,and synthesis methods.It also discusses their applications in supercapacitors and is categorized into:pristine COFs,modified COFs,and COF matrix composites.Finally,the review addresses the challenges that remain for the practical application of these materials in supercapacitors.展开更多
Aims:Surveys and research on the applications of the hepatic venous pressure gradient(HVPG)are important for understanding the current status and future development of this technology in China.This article aimed to in...Aims:Surveys and research on the applications of the hepatic venous pressure gradient(HVPG)are important for understanding the current status and future development of this technology in China.This article aimed to investigate the status of hepatic venous pressure gradient measurement in China in 2022.Methods:We investigated the overall status of HVPG technology in China-including hospital distribution,hospital level,annual number of cases,catheters used,average cost,indications,and current challenges by using online questionnaire.By counting the number and percentages of cases of these results,we hope to clarify the current status of HVPG measurements in China.Results:According to the survey,85 hospitals in China used HVPG technology in 2022 distributed across 29 provinces.A total of 4989 HVPG measurements were performed in all of the surveyed hospitals in 2022,of which 2813 cases(56.4%)were measured alone.The average cost of HVPG measurement was 5646.8±2327.9 CNY.Of the clinical teams who performed the measurements(sometimes multiple per hospital),94.3%(82/87)used the balloon method,and the majority of the teams(72.4%,63/87)used embolectomy catheters.Conclusions:This survey clarified the clinical application status of HVPG in China and confirmed that some medical institutions in China have established a foundation for this technology.It is still necessary to continue promoting and popularizing this technology in the future.展开更多
To the Editor,Upper gastrointestinal bleeding(UGIB)caused by portal hypertension is not uncommon in clinical practice,but UGIB caused by superior mesenteric arteriovenous fistula(SMAVF)is extremely rare.The primary et...To the Editor,Upper gastrointestinal bleeding(UGIB)caused by portal hypertension is not uncommon in clinical practice,but UGIB caused by superior mesenteric arteriovenous fistula(SMAVF)is extremely rare.The primary etiologies of SMAVF are associated with traumatic or iatrogenic injury,and congenital lesions.1,2 Although many patients remain asymptomatic after unrecognized injury to the superior mesenteric artery(SMA)for many years,most previous studies reported delayed presentation of persistent epigastric pain,vomiting and nausea,ascites,mesenteric ischemia,or bleeding.The incidence of SMAVF is 0.09%,with a mortality rate of 39%–77%.3 Thus,prompt diagnosis and treatment are very important to prevent morbidity and mortality.展开更多
Pressurized fluidized beds have been developed in quite a few industrial applications because of intensified heat and mass transfer and chemical reaction.The bubble behaviors under elevated pressure,strongly influenci...Pressurized fluidized beds have been developed in quite a few industrial applications because of intensified heat and mass transfer and chemical reaction.The bubble behaviors under elevated pressure,strongly influencing the fluidization and reaction conversion of the whole system,are of great research significance.In this work,the bubble behaviors of Geldart B particle in a pseudo two-dimensional(2D)pressurized fluidized bed were experimentally studied based on digital image analysis technique.The effects of pressure and fluidization gas velocity on the general bubble behaviors(i.e.,size,shape and spatial distribution)and the dynamic characteristics,such as the time-evolution of voidage distribution and local flow regimes,were comprehensively investigated.Results show that increasing pressure re-duces the stability of bubbles and facilitates gas passing through the emulsion phase,resulting in the"smoother"fluidization state with smaller bubbles and declined bubble fraction and standard deviation.The equivalent bubble diameter and bubble aspect ratio increase with the increasing gas velocity while decrease as pressure rises.The elevated pressure reduces bubbles extension in the vertical direction,prohibits the"short pass"of fluidization gas in large oblong bubbles/slugs and benefits the gas-solid interaction.The flow regimes variation with gas velocity is affected by the elevated pressure,and demonstrates different features in different local positions of the bed.展开更多
在二维半导体与金属材料间引入范德华接触构建器件被认为是解决二维材料电接触问题的有效途径之一.然而,迄今为止,研究主要集中在半导体材料合成与改性上,而对金属材料的制备和性能的研究较少.在这项工作中,我们报道了利用化学气相沉积...在二维半导体与金属材料间引入范德华接触构建器件被认为是解决二维材料电接触问题的有效途径之一.然而,迄今为止,研究主要集中在半导体材料合成与改性上,而对金属材料的制备和性能的研究较少.在这项工作中,我们报道了利用化学气相沉积法可控合成厚度从3.5到10^(6)nm的层状MoO_(2)金属二维纳米片.利用X射线衍射、扫描隧道显微镜和透射电子显微镜对制备的MoO_(2)纳米片进行了系统表征,结果表明,制备的MoO_(2)为单斜晶型、晶质质量高、稳定性好.电学表征表明,MoO_(2)具有优良的导电性能,其导电率超过10^(6)S m^(-1),可与石墨烯和某些金属相媲美.此外,我们还通过引入MoO_(2)薄片作为范德华接触材料,探索了其在MoS_(2)场效应晶体管中的接触应用.所获得的MoS_(2)场效应晶体管表现出低肖特基势垒(36 m e V)和高载流子迁移率(210 cm^(2)V^(-1)s^(-1),10 K).这项工作为金属二维材料的可控制备和应用提供了新思路,并有望促进二维材料电子器件的发展.展开更多
文摘Objective: Digital healthcare is rapidly becoming a new model for medical development in the information society with its convenience, and personalization, and a research boom in digital healthcare has formed at home and abroad in recent years. The purpose of this study is to conduct a bibliometric analysis of the field of digital healthcare and to understand the research background and development trend in this field. Methods: A visual analysis of authors, institutions, journals and keywords was conducted using CiteSpace 5.8R3 software. Results: A total of 1646 digital healthcare-related retrieved from WoS and PubMed studies. There was an overall upward trend in the number of digital healthcare publications, with the highest number of publications in 2021 (290). The author AZIZ SHEIKH is ranked first in the number of published articles (13), while King Saud University (23) is the research institution with the most articles. Keyword clustering showed that the first cluster was data security;the common high frequency keywords that appeared were systems (85), artificial intelligence (82), mobile health (70), internet (61), and technology (57). Digital healthcare, artificial intelligence, healthcare services, machine learning and deep learning are the hotspot of current research. Conclusion: This paper summarises the state of the art in digital healthcare research. Using statistical analysis and network visualisation, it highlights the background, trends and hot topics in digital healthcare research. The paper finds that there is significant potential for artificial intelligence to help bridge the digital divide and reduce health inequalities. To understand the current state, hot trends and future directions of digital healthcare research, this paper can serve as a reference. .
文摘This paper analyzes the current situation of agricultural credit policy in Dingxi City,and further studies the problems in the implementation of credit policy in Dingxi City,and puts forward strategies and suggestions according to these problems.
文摘<strong>Background: </strong>In less than a year, COVID-19 has swept the world and continued, too, seriously threatening the safety of all mankind, and caused great social panic and global economic and financial crisis. At the beginning, the epidemic was first diagnosed in China and the epidemic was severe. Under the strong command of the highest level of the Chinese government, the whole Chinese people united as one, and achieved initial results in the struggle against COVID-19 with scientific prevention and control. <strong>Objective:</strong> Summarizing China’s experience and lessons in combating the epidemic is undoubtedly very beneficial to the people of the world in jointly combating the impact of the COVID-19 epidemic. <strong>Measures:</strong> The article shows the imminent Chinese experience in controlling the spread of SARS-CoV-2. It details the lines of action and the measures taken to control this epidemic in the country where the population is quite large. The most important experience is: strong organizational leadership, enhanced cooperation with the WHO, the establishment of a national anti-epidemic headquarters, responsible for the command and control of human, financial and material resources throughout the country, and local officials at all levels in the front line of the epidemic, Heart to heart with the people, breathing together and sharing a common destiny. Prevention is the first, prevention and treatment are combined. All measures were taken to control the source of infection, cut off the spread and protect susceptible people. <strong>Conclusion: </strong>As long as the people of the world unite, make scientific decisions and learn from the successful experience of countries around the world, especially the China’s experience, combine the national conditions of each country, and use the wisdom of all man-kind to deal with the common enemy SARS-CoV-2 and COVID-19, we can definitely win this people’s war against the disease.
基金the NSF of China(Nos.61574054,61505051,11374092,11204073,61474040,and51302077)the National Basic Research Program of China(No.2012CB932703)+2 种基金the Hunan province science and technology plan(No.2014FJ2001,2014GK3015,and 2014TT1004)the Hunan Provincial Natural Science Foundation of China(No.2015JJ3049)the Aid program for Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province
文摘In Ga As is an important bandgap-variable ternary semiconductor which has wide applications in electronics and optoelectronics. In this work, single-crystal In Ga As nanowires were synthesized by a chemical vapor deposition method.Photoluminescence measurements indicate the In Ga As nanowires have strong light emission in near-infrared region. For the first time, photodetector based on as-grown In Ga As nanowires was also constructed. It shows good light response over a broad spectral range in infrared region with responsivity of 6.5×10~3 AW^(-1) and external quantum efficiency of 5.04×10~5%. This photodetector may have potential applications in integrated optoelectronic devices and systems.
基金This work is supported by National Natural Science Foundation of China(No.92163135,11904098,51972105,U19A2090 and 62090035)Hunan Provincial Natural Science Foundation of China(No.2019JJ30004)+1 种基金Hunan International Innovation Cooperation Platform(No.2018WK4004)Key Program of Science and Technology Department of Hunan Province(Nos.2019XK2001,2020XK2001).
文摘Mix-dimensional van der Waals heterostructures(vdWHs)have inspired worldwide interests and efforts in the field of ad-vanced electronics and optoelectronics.The fundamental understanding of interfacial charge transfer is of vital import-ance for guiding the design of functional optoelectronic applications.In this work,type-Ⅱ0D-2D CdSe/ZnS quantum dots/MoS_(2)vdWHs are designed to study the light-triggered interfacial charge behaviors and enhanced optoelectronic performances.From spectral measurements in both steady and transient states,the phenomena of suppressed photolu-minescence(PL)emissions,shifted Raman signals and changed PL lifetimes provide strong evidences of efficient charge transfer at the 0D-2D interface.A series of spectral evolutions of heterostructures with various QDs overlapping concentrations at different laser powers are analyzed in details,which clarifies the dynamic competition between exciton and trion during an efficient doping of 3.9×10^(13)cm^(−2).The enhanced photoresponses(1.57×10^(4)A·W^(-1))and detectivities(2.86×10^(11)Jones)in 0D/2D phototransistors further demonstrate that the light-induced charge transfer is still a feasible way to optimize the performance of optoelectronic devices.These results are expected to inspire the basic understand-ing of interfacial physics at 0D/2D interfaces,and shed the light on promoting the development of mixed-dimensional op-toelectronic devices in the near future.
基金the National Basic Research Program of China (No. 2012CB932703)the NSF of China (Nos. 11374092 and 11204073)+2 种基金the Research Fund for the Doctoral Program of Higher Education (Nos. 20110161110034, 20110161120027)the Fundamental Research Funds for Central Universities (Nos. xjj2011001 and 2012jdgz04)the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2013)
文摘In this work, we synthesized high-quality In As nanowires by a convenient chemical vapor deposition method,and developed a simple laser heating method to measure the thermal conductivity of a single In As nanowire in air. During the measurement, a focused laser was used to heat one end of a freely suspended nanowire, with its other end embedded into a carbon conductive adhesive. In order to obtain the thermal conductivity of In As nanowires, the heat loss in the heat transfer process was estimated, which includes the heat loss through air conduction, the heat convection, and the radiation loss. The absorption ratio of the laser power in the In As nanowire was calculated. The result shows that the thermal conductivity of In As nanowires monotonically increases from 6.4 W m-1K-1to 10.5 W m-1K-1with diameters increasing from 100 nm to 190 nm, which is ascribed to the enhanced phonon-boundary scattering.
基金funded by the Jiangsu Provincial Medical Talent Funding(ZDRCA2016038)the Suzhou Special Diagnosis and Treatment Technology of Clinical Key Diseases(LCZX201704)+2 种基金the National Natural Science Foundation of China(81771945,81901847)the Natural Science Foundation of Jiangsu Province(BK20190177)the Suzhou Science and Technology Youth Plan(KJXW2018003).
文摘Purpose:We aimed to compare treatment efficacy,safety and material cost between tissue gel and coil regarding variceal embolization during transjugular intrahepatic portosystemic shunt(TIPS).Materials&Methods:This retrospective study including cirrhotic patients with variceal bleeding treated with TIPS combined with variceal embolization between January 2016 and August 2017.Patients were divided into three groups according to embolic agents used in variceal embolization:tissue gel group(Group A),combination group(Group B),and coil group(Group C).The primary endpoint was 1-year rebleeding rate after TIPS creation.The secondary endpoints included shunt dysfunction,overt hepatic encephalopathy,liver function,and embolic agents-related expense.Results:A total of 60 patients(30,10,and 20 in Group A,B,and C)were included.Variceal rebleeding occurred in3(10%),0(0%),and 4(20%)patients within one year after TIPS creation in Group A,B,and C,respectively.Stent dysfunction occurred in 2(3.3%)patients and 9(15.0%)patients experienced overt hepatic encephalopathy.No significant differences were observed between three groups regarding primary and secondary endpoints except embolic agents-related expense,with a significantly lower cost in Group A when compared to the other two groups.Stent dysfunction occurred in two patients,with one patient in Group A developed acute occlusion caused by thrombus and another patient in Group C underwent stent stenosis during follow-up.Conclusions:Compares to coil alone or combines with coil,tissue gel has similar treatment efficacy and safety,but with significantly lower cost for variceal bleeding during TIPS.
基金supported by the Jiangsu Provincial Medical Talent Funding (ZDRCA2016038)the Suzhou Special Diagnosis and Treatment Technology of Clinical Key Diseases (LCZX201704)+2 种基金the National Natural Science Foundation of China (81771945, 81901847)the Natural Science Foundation of Jiangsu Province (BK20190177)the Suzhou Science and Technology Youth Plan (KJXW2018003)。
文摘Objectives:To present a case series of modified transjugular intrahepatic portosystemic shunts(TIPS) and percutaneous transhepatic intrahepatic portosystemic shunts(PTIPS) in cirrhotic patients with variceal bleeding(VB).In addition,the scientific literature pertaining to PTIPS was reviewed.Methods:This retrospective clinical case series included six cirrhotic patients with VB who were treated with PTIPS after the failure of endoscopic band ligation or endoscopic injection sclerotherapy combined with vasoactive drugs.The treatment was conducted between January 2017 and June 2019 at a single institution.Three patients suffered from severe atrophy of the right or left lobar of the liver as well as the main right or left branch of the portal vein.The remaining three patients showed severe atrophy of the whole liver and portal vein,resulting in widening of the liver fissure.A paired t-test was used to compare the changes in portal pressure gradient between before and after the PTIPS operation.The rebleeding rate,treatment efficacy,complications,and technical success rate were all assessed during follow-up.Results:All six PTIPS procedures were performed successfully,with no severe procedural-related complications observed.None of the patients experienced VB during a mean follow-up of 22.8(range,18.0-28.0) months.The mean portosystemic pressure gradient decreased from 28.3 ± 4.3 mmHg pre-procedure to 12.3 ± 2.6 mmHg immediately post-procedure(P <0.001).At follow-up,one patient was found to have developed grade 2 hepatic encephalopathy thrice during the first year,according to the West Haven criteria.However,this was resolved following medical treatment.Conclusions:When the patient’s portal venous anatomy is unconducive to the performance of TIPS using the transjugular approach,PTIPS can be considered as a safe,effective complementary surgical approach for patients with VB.
基金financially supported by the Natural Science Foundation of Shandong Province,China(grant numbers ZR2021MB112,ZR2019MB031,ZR2020QB065)Natural Science Foundation of Guangdong Province,China(grant number2020A1515110374)Science and Technology Bureau of Jinan City,Shandong Province,China(2021GXRC105)。
文摘Highly efficient and robust electrocatalysts have been in urgent demand for oxygen evolution reaction(OER).For this purpose,high-cost carbon materials,such as graphene and carbon nanotubes,have been used as supports to metal oxides to enhance their catalytic activity.We report here a new Co_(3)O_(4)-based catalyst with nitrogen-doped porous carbon material as the support,prepared by pyrolysis of porous polyurea(PU) with Co(NO_(3))_(2)immobilized on its surface.To this end,PU was first synthesized,without any additive,through a very simple one-step precipitation polymerization of toluene diisocyanate in a binary mixture of H2O-acetone at room temperature.By immersing PU in an aqueous solution of Co(NO_(3))_(2)at room temperature,a cobalt coordinated polymer composite,Co(NO_(3))_(2)/PU,was obtained,which was heated at 500℃ in air for 2 h to get a hybrid,Co_(3)O_(4)/NC,consisting of Co_(3)O_(4)nanocrystals and sp2-hybridized N-doped carbon.Using this Co_(3)O_(4)/NC as a catalyst in OER,a current density of10 mA·cm^(-2)was readily achieved with a low overpotential of 293 mV with a Tafel slope of87 mV·dec^(-1),a high catalytic activity.This high performance was well retained after 1000 recycled uses,demonstrating its good durability.This work provides therefore a facile yet simple pathway to fabrication of a new transition metal oxides-based N-doped carbon catalyst for OER with high performance.
基金Supported by Research Project of Yunnan "Three Rural Issues" and New Rural Construction Research Base in 2016Youth Social Science Project of Yunnan Agricultural University(2015SK01)
文摘The development of agriculture with plateau characteristics is a market-oriented strategic choice,made by Yunnan Province,of agricultural economy with regional characteristics,on the basis of resources and location advantages,as well as geographical division of the national economy. The characteristic agribusiness is an important carrier for building a new agricultural management system with plateau characteristics,and also a key way to promote characteristic agricultural industrialization. In this paper,with 26 agribusinesses with plateau characteristics in Yunnan Province as samples,we establish the competitiveness evaluation system for the agribusiness with plateau characteristics,and use the operating data( 2012-2014) and AHP to calculate and the sample business competitiveness index and sort these businesses. Finally,we make a comprehensive analysis on the competitiveness of sample agribusinesses with plateau characteristics in Yunnan Province,in order to provide decision-making basis for promotion of the competitiveness of the agribusiness with plateau characteristics.
基金supported by grants from the National Science Grant for Distinguished Young Scholars(No.81425001/H0104)the National Key Technology Support Program from the Ministry of Science and Technology(No.2015BAI12B11)the Beijing Science and Technology Project(No.D151100002115004)
文摘To the Editor:With an aging global population,the incidences of community-acquired pneumonia(CAP)and chronic obstructive pulmonary disease(COPD)have signicantly increased.[1]Previous studies have conrmed that COPD and asthma are independently associated with the prevalence of CAP.The use of inhaled corticosteroid(ICS),the cornerstone of treatment for asthma,COPD with frequent acute exacerbations,and asthma-COPD overlap(ACO)may induce changes in the local lung microbiome and abnormal lung immunity,ultimately,causing a signicantly increased risk of pneumonia.However,in cases of pneumonia,the effect of the use of ICS on CAP mortality remains controversial.While data from one study favored the prior use of ICS,which was associated with a signicantly lower short-term mortality rate,[2]other studies have identied no impact on mortality.To date,data on the impact of the use of ICS on mortality,prehospitalization or during hospitalization,are scarce,particularly in the older population.Therefore,this multicenter,retrospective study explored the association between the use of ICS during hospitalization and short-term mortality in older patients with CAP and those with chronic pulmonary disease(CPD).
文摘E-beam lithography is a powerful tool for generating nanostructures and fabricating nanodevices with fine features approaching a few nanometers in size.However,alternative approaches to conventional spin coating and development processes are required to optimize the lithography procedure on irregular surfaces.In this review,we summarize the state of the art in nanofabrication on irregular substrates using e-beam lithography.To overcome these challenges,unconventional methods have been developed.For instance,polymeric and nonpolymeric materials can be sprayed or evaporated to form uniform layers of electron-sensitive materials on irregular substrates.Moreover,chemical bonds can be applied to help form polymer brushes or self-assembled monolayers on these surfaces.In addition,thermal oxides can serve as resists,as the etching rate in solution changes after e-beam exposure.Furthermore,e-beam lithography tools can be combined with cryostages,evaporation systems,and metal deposition chambers for sample development and lift-off while maintaining low temperatures.Metallic nanopyramids can be fabricated on an AFM tip by utilizing ice as a positive resistor.Additionally,Ti/Au caps can be patterned around a carbon nanotube.Moreover,3D nanostructures can be formed on irregular surfaces by exposing layers of anisole on organic ice surfaces with a focused e-beam.These advances in e-beam lithography on irregular substrates,including uniform film coating,instrumentation improvement,and new pattern transferring method development,substantially extend its capabilities in the fabrication and application of nanoscale structures.
基金supported by the National Natural Science Foundation of China(62375079,52072117,62375081,52221001,51972105,62090035,U19A2090,and 61905071)the National Key R&D Program of China(2022YFA1204300)+4 种基金the Key Program of Science and Technology Department of Hunan Province(2019XK2001 and 2020XK2001)the Key Research and Development Plan of Hunan Province(2023GK2012)the Open Project Program of Key Laboratory of Nanodevices and Applications,Suzhou Institute of Nano-Tech and Nano-Bionics,Chinese Academy of Sciences(22ZS01)the Hunan Provincial Natural Science Foundation of China(2021JJ30132)the China Scholarship Council.
基金financially supported by the National Key Research and Development Program of China(No.2021YFC1808902)the National Natural Science Foundation of China(No.42307546)+1 种基金the Key Research and Development Program of Shaanxi Province(China)(Nos.2019NY200,2020ZDLNY06-06,and 2020ZDLNY07-10)the Agricultural Technology Innovation Driven Program of Shaanxi Province(China)(No.NYKJ-2022-XA-02).
文摘Heavy metals(HMs)represent pervasive and highly toxic environmental pollutants,known for their long latency periods and high toxicity levels,which pose significant challenges for their removal and degradation.Therefore,the removal of heavy metals from the environment is crucial to ensure the water safety.Biochar materials,known for their intricate pore structures and abundant oxygen-containing functional groups,are frequently harnessed for their effectiveness in mitigating heavy metal contamination.However,conventional tests for optimizing biochar synthesis and assessing their heavy metal adsorption capabilities can be both costly and tedious.To address this challenge,this paper proposes a data-driven machine learning(ML)approach to identify the optimal biochar preparation and adsorption reaction conditions,with the ultimate goal of maximizing their adsorption capacity.By utilizing a data set comprising 476 instances of heavy metal absorption by biochar,seven classical integrated models and one stacking model were trained to rapidly predict the efficiency of heavy metal adsorption by biochar.These predictions were based on diverse physicochemical properties of biochar and the specific adsorption reaction conditions.The results demonstrate that the stacking model,which integrates multiple algorithms,allows for training with fewer samples to achieve higher prediction accuracy and improved generalization ability.
基金financially supported by the National Key Research and Development Program of China(Grant No.2021YFC1808903).
文摘Supercapacitors have garnered significant attention due to their superior power density,excellent cycle stability,and fast charge/discharge rates.The properties of the electrode materials determine the charge storage performance of supercapacitors.Covalent organic frameworks(COFs)are a novel class of crystalline porous polymer materials with uniform nanoscale pores,large specific surface areas,and tunable redox-active groups within the framework,which can be tuned to suit specific applications.They have flexible molecular designs and synthetic strategies,demonstrating their strong application potential in the field of energy storage.Most COFs exhibit poor inherent conductivity and low utilization of active sites,resulting in incomplete electrochemical performance.Hybrid systems can be developed by incorporating redox-active groups,hydrogen bonding,or combining COFs with other materials to improve the energy storage performance of COFs materials.In this review article,the background of COFs is summarized,including a brief introduction,design strategy,and synthesis methods.It also discusses their applications in supercapacitors and is categorized into:pristine COFs,modified COFs,and COF matrix composites.Finally,the review addresses the challenges that remain for the practical application of these materials in supercapacitors.
文摘Aims:Surveys and research on the applications of the hepatic venous pressure gradient(HVPG)are important for understanding the current status and future development of this technology in China.This article aimed to investigate the status of hepatic venous pressure gradient measurement in China in 2022.Methods:We investigated the overall status of HVPG technology in China-including hospital distribution,hospital level,annual number of cases,catheters used,average cost,indications,and current challenges by using online questionnaire.By counting the number and percentages of cases of these results,we hope to clarify the current status of HVPG measurements in China.Results:According to the survey,85 hospitals in China used HVPG technology in 2022 distributed across 29 provinces.A total of 4989 HVPG measurements were performed in all of the surveyed hospitals in 2022,of which 2813 cases(56.4%)were measured alone.The average cost of HVPG measurement was 5646.8±2327.9 CNY.Of the clinical teams who performed the measurements(sometimes multiple per hospital),94.3%(82/87)used the balloon method,and the majority of the teams(72.4%,63/87)used embolectomy catheters.Conclusions:This survey clarified the clinical application status of HVPG in China and confirmed that some medical institutions in China have established a foundation for this technology.It is still necessary to continue promoting and popularizing this technology in the future.
基金supported by the Key Research and Development Plan(Social Development)Project of the Jiangsu Provincial Department of Science and Technology(No.BE2021648)the Jiangsu Provincial Natural Science Foundation General Project(No.SBK2023022210).
文摘To the Editor,Upper gastrointestinal bleeding(UGIB)caused by portal hypertension is not uncommon in clinical practice,but UGIB caused by superior mesenteric arteriovenous fistula(SMAVF)is extremely rare.The primary etiologies of SMAVF are associated with traumatic or iatrogenic injury,and congenital lesions.1,2 Although many patients remain asymptomatic after unrecognized injury to the superior mesenteric artery(SMA)for many years,most previous studies reported delayed presentation of persistent epigastric pain,vomiting and nausea,ascites,mesenteric ischemia,or bleeding.The incidence of SMAVF is 0.09%,with a mortality rate of 39%–77%.3 Thus,prompt diagnosis and treatment are very important to prevent morbidity and mortality.
基金Financial support of this work by the National Natural Science Foundation of China(grant No.52106216)Fundamental Research Funds for the Central Universities(grant No.27RA2114005)are gratefully acknowledged.
文摘Pressurized fluidized beds have been developed in quite a few industrial applications because of intensified heat and mass transfer and chemical reaction.The bubble behaviors under elevated pressure,strongly influencing the fluidization and reaction conversion of the whole system,are of great research significance.In this work,the bubble behaviors of Geldart B particle in a pseudo two-dimensional(2D)pressurized fluidized bed were experimentally studied based on digital image analysis technique.The effects of pressure and fluidization gas velocity on the general bubble behaviors(i.e.,size,shape and spatial distribution)and the dynamic characteristics,such as the time-evolution of voidage distribution and local flow regimes,were comprehensively investigated.Results show that increasing pressure re-duces the stability of bubbles and facilitates gas passing through the emulsion phase,resulting in the"smoother"fluidization state with smaller bubbles and declined bubble fraction and standard deviation.The equivalent bubble diameter and bubble aspect ratio increase with the increasing gas velocity while decrease as pressure rises.The elevated pressure reduces bubbles extension in the vertical direction,prohibits the"short pass"of fluidization gas in large oblong bubbles/slugs and benefits the gas-solid interaction.The flow regimes variation with gas velocity is affected by the elevated pressure,and demonstrates different features in different local positions of the bed.
基金supported by the National Key R&D Program of China(2022YFA1402501)the National Natural Science Foundation of China(51902098,51972105,U19A2090,U22A20138,62090035,and 12104144)+3 种基金the Key Program of Science and Technology Department of Hunan Province(2019XK2001 and 2020XK2001)the Science and Technology Innovation Program of Hunan Province(2021RC3061,2020RC2028,and 2021RC2042)the Natural Science Foundation of Hunan Province(2021JJ30132 and 2021JJ20016)China Postdoctoral Science Foundation(BX2021094,2020M680112,and 2021M690953)。
文摘在二维半导体与金属材料间引入范德华接触构建器件被认为是解决二维材料电接触问题的有效途径之一.然而,迄今为止,研究主要集中在半导体材料合成与改性上,而对金属材料的制备和性能的研究较少.在这项工作中,我们报道了利用化学气相沉积法可控合成厚度从3.5到10^(6)nm的层状MoO_(2)金属二维纳米片.利用X射线衍射、扫描隧道显微镜和透射电子显微镜对制备的MoO_(2)纳米片进行了系统表征,结果表明,制备的MoO_(2)为单斜晶型、晶质质量高、稳定性好.电学表征表明,MoO_(2)具有优良的导电性能,其导电率超过10^(6)S m^(-1),可与石墨烯和某些金属相媲美.此外,我们还通过引入MoO_(2)薄片作为范德华接触材料,探索了其在MoS_(2)场效应晶体管中的接触应用.所获得的MoS_(2)场效应晶体管表现出低肖特基势垒(36 m e V)和高载流子迁移率(210 cm^(2)V^(-1)s^(-1),10 K).这项工作为金属二维材料的可控制备和应用提供了新思路,并有望促进二维材料电子器件的发展.
