Objective:To validate the 8 th edition of the American Joint Committee on Cancer(AJCC)staging system for pancreatic ductal adenocarcinoma(PDAC)in a Chinese cohort of radically resected patients and to develop a refine...Objective:To validate the 8 th edition of the American Joint Committee on Cancer(AJCC)staging system for pancreatic ductal adenocarcinoma(PDAC)in a Chinese cohort of radically resected patients and to develop a refined staging system for PDAC.Methods:Data were collected from the China Pancreas Data Center(CPDC)for patients with resected PDAC in 2016 and 2017,and cancer-specific survival(CSS)was evaluated using the Kaplan-Meier method and log-rank test.Univariate and multivariate analyses based on Cox regression were performed to identify prognostic factors.The recursive partitioning analysis(RPA),Kaplan-Meier method,and log-rank test were performed on the training dataset to generate a proposed modification for the 8 th TNM staging system utilizing the preoperative carbohydrate antigen(CA)19-9 level.Validation was performed for both staging systems in the validation cohort.Results:A total of 1,676 PDAC patients were retrieved,and the median CSS was significantly different between the 8 th TNM groupings,with no significant difference in survival between stage IB and IIA.The analysis of T and N stages demonstrated a better prognostic value in the N category.Multivariate analysis showed that the preoperative serum CA19-9 level was the strongest prognostic indicator among all the independent risk factors.All patients with CA19-9>500 U/mL had similar survival,and we proposed a new staging system by combining IB and IIA and stratifying all patients with high CA19-9 into stage III.The modified staging system had a better performance for predicting CSS than the 8 th AJCC staging scheme.Conclusions:The 8 th AJCC staging system for PDAC is suitable for a Chinese cohort of resected patients,and the N category has a better prognostic value than the T category.Our modified staging system has superior accuracy in predicting survival than the 8 th AJCC TNM staging system.展开更多
The yellowing of leaves caused by the decomposition of chlorophyll(Chl)is a characteristic event during senescence,which can be induced by various environmental stresses.However,the molecular mechanisms of high temper...The yellowing of leaves caused by the decomposition of chlorophyll(Chl)is a characteristic event during senescence,which can be induced by various environmental stresses.However,the molecular mechanisms of high temperature-induced Chl degradation in horticultural plants remain poorly understood.Here,we found that heat stress induced Chl degradation and the expression of ABI5 and MYB44 in cucumber.Silencing of ABI5 compromised heat stress-induced Chl degradation,and the transcription of pheophytinase(PPH)and pheophorbide a oxygenase(PAO),two key genes in Chl catabolic pathway,but silencing of MYB44 exhibited the opposite results.Furthermore,ABI5 interacted with MYB44 in vitro and in vivo.ABI5 positively regulated heat stress-induced Chl degradation through two pathways.ABI5 directly bound to PPH and PAO promoters to promote their expression,leading to accelerating Chl degradation.On the other hand,the interaction between ABI5 and MYB44 reduced the binding of MYB44 to PPH and PAO promoters and led to the ubiquitination-depended protein degradation of MYB44,thereby alleviating the transcription inhibitory effect of MYB44 on PPH and PAO.Taken together,our findings propose a new regulatory network for ABI5 in regulating heat stress-induced Chl degradation.展开更多
In plants and algae,PGR5-dependent cyclic electron flow(CEF)is an important regulator of acclimation to fluctuating environments,but how PGR5 participates in CEF is unclear.In this work,we analyzed two PGR5s in cucumb...In plants and algae,PGR5-dependent cyclic electron flow(CEF)is an important regulator of acclimation to fluctuating environments,but how PGR5 participates in CEF is unclear.In this work,we analyzed two PGR5s in cucumber(Cucumis sativus L.)under different conditions and found that CsPGR5a played the dominant role in PGR5-dependent CEF.The results of yeast two-hybrid,biomolecular fluorescence complementation(BiFC),blue native PAGE,and coimmunoprecipitation(CoIP)assays showed that PGR5a interacted with PetC,Lhcb3,and PsaH.Furthermore,the intensity of the interactions was dynamic during state transitions,and the abundance of PGR5 attached to cyt b_(6)f decreased during the transition from state 1 to state 2,which revealed that the function of PGR5a is related to the state transition.We proposed that PGR5 is a small mobile protein that functions when attached to protein complexes.展开更多
Achieving larger electromagnetic enhancement using a nanogap between neighboring metallic nanostructures has been long pursued for boosting light–matter interactions.However,the quantitative probing of this enhanceme...Achieving larger electromagnetic enhancement using a nanogap between neighboring metallic nanostructures has been long pursued for boosting light–matter interactions.However,the quantitative probing of this enhancement is hindered by the lack of a reliable experimental method for measuring the local fields within a subnanometer gap.Here,we use layered MoS2 as a two-dimensional atomic crystal probe in nanoparticle-on-mirror nanoantennas to measure the plasmonic enhancement in the gap by quantitative surface-enhanced Raman scattering.Our designs ensure that the probe filled in the gap has a well-defined lattice orientation and thickness,enabling independent extraction of the anisotropic field enhancements.We find that the field enhancement can be safely described by pure classical electromagnetic theory when the gap distance is no<1.24 nm.For a 0.62 nm gap,the probable emergence of quantum mechanical effects renders an average electric field enhancement of 114-fold,38.4%lower than classical predictions.展开更多
Control measures during the coronavirus disease 2019(COVID-19)outbreak may have limited the spread of infectious diseases.This study aimed to analyze the impact of COVID-19 on the spread of hand,foot,and mouth disease...Control measures during the coronavirus disease 2019(COVID-19)outbreak may have limited the spread of infectious diseases.This study aimed to analyze the impact of COVID-19 on the spread of hand,foot,and mouth disease(HFMD)in China.A mathematical model was established to fit the reported data of HFMD in six selected cities in China's Mainland from 2015 to 2020.The absolute difference(AD)and relative difference(RD)between the reported incidence in 2020,and simulated maximum,minimum,or median incidence of HFMD in 2015-2019 were calculated.The incidence and R effof HFMD have decreased in six selected cities since the outbreak of COVID-19,and in the second half of 2020,the incidence and R effof HFMD have rebounded.The results show that the total attack rate(TAR)in 2020 was lower than the maximum,minimum,and median TAR fitted in previous years in six selected cities(except Changsha City).For the maximum,median,minimum fitted TAR,the range of RD(%)is 42·20-99·20%,36·35-98·41%48·35-96·23%(except Changsha City)respectively.The preventive and control measures of COVID-19 have significantly contributed to the containment of HFMD transmission.展开更多
Introduction:The coronavirus disease 2019(COVID-19)pandemic recently affected Taiwan,China.This study aimed to calculate the transmissibility of COVID-19 to predict trends and evaluate the effects of interventions.Met...Introduction:The coronavirus disease 2019(COVID-19)pandemic recently affected Taiwan,China.This study aimed to calculate the transmissibility of COVID-19 to predict trends and evaluate the effects of interventions.Methods:The data of reported COVID-19 cases was collected from April 20 to May 26,2021,which included daily reported data(Scenario I)and reported data after adjustment(Scenario II).A susceptibleexposed-symptomatic-asymptomatic-recovered model was developed to fit the data.The effective reproductive number(Reff)was used to estimate the transmissibility of COVID-19.Results:A total of 4,854 cases were collected for the modelling.In Scenario I,the intervention has already taken some effects from May 17 to May 26(the Reff reduced to 2.1).When the Reff was set as 0.1,the epidemic was projected to end on July 4,and a total of 1,997 cases and 855 asymptomatic individuals would have been reported.In Scenario II,the interventions were projected as having been effective from May 24 to May 26(the Reff reduced to 0.4).When the Reff was set as 0.1,the epidemic was projected to end on July 1,and a total of 1,482 cases and 635 asymptomatic individuals would have been reported.Conclusion:The epidemic of COVID-19 was projected to end after at least one month,even if the most effective interventions were applied in Taiwan,China.Although there were some positive effects of intervention in Taiwan,China.展开更多
Introduction:Vaccination booster shots are completely necessary for controlling breakthrough infections of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in China.The study aims to estimate effectiveness o...Introduction:Vaccination booster shots are completely necessary for controlling breakthrough infections of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in China.The study aims to estimate effectiveness of booster vaccines for high-risk populations(HRPs).Methods:A vaccinated Susceptible-Exposed-Symptomatic-Asymptomatic-Recovered/Removed(SEIAR)model was developed to simulate scenarios of effective reproduction number(Reff)from 4 to 6.Total number of infectious and asymptomatic cases were used to evaluated vaccination effectiveness.Results:Our model showed that we could not prevent outbreaks when covering 80%of HRPs with booster unless Reff=4.0 or the booster vaccine had efficacy against infectivity and susceptibility of more than 90%.The results were consistent when the outcome index was confirmed cases or asymptomatic cases.Conclusions:An ideal coronavirus disease 2019(COVID-19)booster vaccination strategy for HRPs would be expected to reach the initial goal to control the transmission of the Delta variant in China.Accordingly,the recommendation for the COVID-19 booster vaccine should be implemented in HRPs who are already vaccinated and could prevent transmission to other groups.展开更多
The photothermoelectric(PTE)effect enables efficient harvesting of the energy of photogenerated hot carriers and is a promising choice for high-efficiency photoelectric energy conversion and photodetection.Recently,th...The photothermoelectric(PTE)effect enables efficient harvesting of the energy of photogenerated hot carriers and is a promising choice for high-efficiency photoelectric energy conversion and photodetection.Recently,the PTE effect was reported in low-dimensional nanomaterials,suggesting the possibility of optimizing their energy conversion efficiency.Unfortunately,the PTE effect becomes extremely inefficient in low-dimensional nanomaterials,owing to intrinsic disadvantages,such as low optical absorption and immature fabrication methods.In this study,a giant PTE effect was observed in lightly doped p-type silicon nanoribbons caused by photogenerated hot carriers.The open-circuit photovoltage responsivity of the device was 3-4 orders of magnitude higher than those of previously reported PTE devices.The measured photovoltage responses fit very well with the proposed photothermoelectric multiphysics models.This research proposes an application of the PTE effect and a possible method for utilizing hot carriers in semiconductors to significantly improve their photoelectric conversion efficiency.展开更多
The monocular vision-based system can obtain the leaf wall area characterizing the canopy parameter for online detection and real-time variable spraying,aiming to improve the accuracy of orchard spraying equipment and...The monocular vision-based system can obtain the leaf wall area characterizing the canopy parameter for online detection and real-time variable spraying,aiming to improve the accuracy of orchard spraying equipment and the utilization efficiency of pesticide.This study established a spraying system,in which canopy parameters were collected by monocular vision,and the spray volume decision coefficient was constructed by the leaf wall area and the L^(*)value in International Commission on Illumination Lab color space to control the duty cycle of each solenoid valve to achieve variable spraying.Four spray flow models were designed to determine the spray volume decision coefficient.The coefficients of determination of the spray volumes with the duty cycle range of 15%to 65%were all over 94 and the error of the leaf wall area values obtained using the improved super green algorithm(calculated as ExG=2.1G–1.1R–1.1B)was only 0.5%.The test showed that there is a negative relationship between canopy denseness and L^(*),and the value of L^(*)is smaller in the dense area compared with the sparse area;the actual flow generated by the system is similar to the theoretical flow when the duty cycle is 65%.The field validation tests showed that the variable spraying system could refine the droplet size and increase the droplet density to a certain extent with the same coverage rate,which had advantages over the continuous spraying.In terms of droplet deposition,DV0.1 and DV0.9 were reduced by 2μm and 18μm,respectively,and the increase of droplet density to 75 droplets/cm2.At the same time,the improvement of droplet distribution uniformity and droplet penetration by 16%and 3%,respectively.Compared with continuous spraying,variable spraying can achieve 55.64%savings.The study demonstrates the feasibility of monocular vision in guiding spraying operations and provides a reference for the use of monocular vision in plant protection operations.展开更多
Together with the development of the focused assessment with sonography for trauma protocol for ultrasound in trauma patients,point-of-care ultrasound is widely used in the field of emergency and critical care medicin...Together with the development of the focused assessment with sonography for trauma protocol for ultrasound in trauma patients,point-of-care ultrasound is widely used in the field of emergency and critical care medicine.Researchers have established several classic operating protocols for different diseases,such as acute respiratory failure,shock,and cardiac arrest,in the emergency department and intensive care unit.With further development in the portability and popularity of ultrasonic equipment,it is expected to be used as a new type of technology for physical examination,including inspection,palpation,percussion,auscultation,and insonation,which will improve the clinical medicine practice in the future.展开更多
After the policy adjustment,China no longer carries out COVID-19 PCR testing for all people,and antigen testing has become the main way to detect and manage infectious sources.We developed a dynamic model to evaluate ...After the policy adjustment,China no longer carries out COVID-19 PCR testing for all people,and antigen testing has become the main way to detect and manage infectious sources.We developed a dynamic model to evaluate and compare the effects between PCR and antigen testing for controlling the pandemic.Due to the increase of contact degree,the peak reduction effect of PCR testing in population is lower than that of antigen testing.Even if it was only 20%of people isolated at home after antigen testing,the peak of the epidemic could be reduced by 9.46%.If the proportion of antigen testing is further increased to 80%,the peak of the pandemic can be reduced by 31.41%.Antigen testing performed better effects in school(reduction proportion 29.27%)and community(29.34%)than in workplace(27.75%).Therefore,we recommend that antigen testing in the popu-lation should be encouraged during the pandemic,and home isolation of infected persons should be advocated,especially in crowded places.To improve the availability of antigen,the testing proportion should be further enhanced.展开更多
Objective:This study elaborated the natural history parameters of Delta variant,explored the differences in detection cycle thresholds(Ct)among cases.Methods:Natural history parameters were calculated based on the dif...Objective:This study elaborated the natural history parameters of Delta variant,explored the differences in detection cycle thresholds(Ct)among cases.Methods:Natural history parameters were calculated based on the different onset time and exposure time of the cases.Intergenerational relationships between generations of cases were calculated.Differences in Ct values of cases by gender,age,and mode of detection were analyzed statistically to assess the detoxification capacity of cases.Results:The median incubation period was 4 days;the detection time for cases decreased from 25 to 7 h as the outbreak continued.The average generation time(GT),time interval between transmission generations(TG)and serial interval(SI)were 3.6±2.6 days,1.67±2.11 days and 1.7±3.0 days.Among the Ct values,we found little differences in testing across companies,but there were some differences in the gender of detected genes.The Ct values continuous to decreased with age,but increased when the age was greater than 60.Conclusion:This epidemic was started from aggregation of factories.It is more reasonable to use SI to calculate the effective reproduction number and the time-varying reproduction number.And the analysis of Ct values can improve the positive detection rate and improve prevention and control measures.展开更多
Introduction:The aim of this study was to construct an assessment method for cross-regional transmission of coronavirus disease 2019(COVID-19)and to provide recommendations for optimizing measures such as interregiona...Introduction:The aim of this study was to construct an assessment method for cross-regional transmission of coronavirus disease 2019(COVID-19)and to provide recommendations for optimizing measures such as interregional population movements.Methods:Taking Xi’an City as the example subject of this study’s analysis,a Cross-Regional-Gravitational-Dynamic model was constructed to simulate the epidemic in each district of Xi’an under three scenarios of controlled population movement(Scenario 1:no intensive intervention;Scenario 2:blocking Yanta District on December 18 and blocking the whole region on December 23;and Scenario 3:blocking the whole region on December 23).This study then evaluated the effects of such simulated population control measures.Results:The cumulative number of cases for the three scenarios was 8,901,425,178,and 474,respectively,and the duration of the epidemic was 175,18,and 22 days,respectively.The real world prevention and control measures in Xi’an reduced the cumulative number of cases for its outbreak by 99.98%in comparison to the simulated response in Scenario 1;in contrast,the simulated prevention and control strategies set in Scenarios 2(91.26%)and 3(76.73%)reduced cases even further than the real world measures used in Xi’an.Discussion:The constructed model can effectively simulate an outbreak across regions.Timely implementation of two-way containment and control measures in areas where spillover is likely to occur is key to stopping cross-regional transmission.展开更多
基金supported by grants from the National Natural Science Foundation of China(No.81672353 and 81871954)。
文摘Objective:To validate the 8 th edition of the American Joint Committee on Cancer(AJCC)staging system for pancreatic ductal adenocarcinoma(PDAC)in a Chinese cohort of radically resected patients and to develop a refined staging system for PDAC.Methods:Data were collected from the China Pancreas Data Center(CPDC)for patients with resected PDAC in 2016 and 2017,and cancer-specific survival(CSS)was evaluated using the Kaplan-Meier method and log-rank test.Univariate and multivariate analyses based on Cox regression were performed to identify prognostic factors.The recursive partitioning analysis(RPA),Kaplan-Meier method,and log-rank test were performed on the training dataset to generate a proposed modification for the 8 th TNM staging system utilizing the preoperative carbohydrate antigen(CA)19-9 level.Validation was performed for both staging systems in the validation cohort.Results:A total of 1,676 PDAC patients were retrieved,and the median CSS was significantly different between the 8 th TNM groupings,with no significant difference in survival between stage IB and IIA.The analysis of T and N stages demonstrated a better prognostic value in the N category.Multivariate analysis showed that the preoperative serum CA19-9 level was the strongest prognostic indicator among all the independent risk factors.All patients with CA19-9>500 U/mL had similar survival,and we proposed a new staging system by combining IB and IIA and stratifying all patients with high CA19-9 into stage III.The modified staging system had a better performance for predicting CSS than the 8 th AJCC staging scheme.Conclusions:The 8 th AJCC staging system for PDAC is suitable for a Chinese cohort of resected patients,and the N category has a better prognostic value than the T category.Our modified staging system has superior accuracy in predicting survival than the 8 th AJCC TNM staging system.
基金This work was funded by the National Natural Science Foundation of China(31872152)the Open Fundation of the Key Laboratory of Horticulture for Southern Mountainous Regions,Ministry of Education,Southwest University,the China Agriculture Research System(CARS-23)the Postdoctoral Research Funding Scheme of Jiangsu Province(2019 K071).
文摘The yellowing of leaves caused by the decomposition of chlorophyll(Chl)is a characteristic event during senescence,which can be induced by various environmental stresses.However,the molecular mechanisms of high temperature-induced Chl degradation in horticultural plants remain poorly understood.Here,we found that heat stress induced Chl degradation and the expression of ABI5 and MYB44 in cucumber.Silencing of ABI5 compromised heat stress-induced Chl degradation,and the transcription of pheophytinase(PPH)and pheophorbide a oxygenase(PAO),two key genes in Chl catabolic pathway,but silencing of MYB44 exhibited the opposite results.Furthermore,ABI5 interacted with MYB44 in vitro and in vivo.ABI5 positively regulated heat stress-induced Chl degradation through two pathways.ABI5 directly bound to PPH and PAO promoters to promote their expression,leading to accelerating Chl degradation.On the other hand,the interaction between ABI5 and MYB44 reduced the binding of MYB44 to PPH and PAO promoters and led to the ubiquitination-depended protein degradation of MYB44,thereby alleviating the transcription inhibitory effect of MYB44 on PPH and PAO.Taken together,our findings propose a new regulatory network for ABI5 in regulating heat stress-induced Chl degradation.
基金the National Key Research and Development Program of China(2018YFD1000800)the National Natural Science Foundation of China(No.31672199 and No.31471869)the China Agriculture Research System(CARS-23-B12).
文摘In plants and algae,PGR5-dependent cyclic electron flow(CEF)is an important regulator of acclimation to fluctuating environments,but how PGR5 participates in CEF is unclear.In this work,we analyzed two PGR5s in cucumber(Cucumis sativus L.)under different conditions and found that CsPGR5a played the dominant role in PGR5-dependent CEF.The results of yeast two-hybrid,biomolecular fluorescence complementation(BiFC),blue native PAGE,and coimmunoprecipitation(CoIP)assays showed that PGR5a interacted with PetC,Lhcb3,and PsaH.Furthermore,the intensity of the interactions was dynamic during state transitions,and the abundance of PGR5 attached to cyt b_(6)f decreased during the transition from state 1 to state 2,which revealed that the function of PGR5a is related to the state transition.We proposed that PGR5 is a small mobile protein that functions when attached to protein complexes.
基金supported by the National Key Basic Research Program(Grant No.2015CB932400)the National Key R&D Program of China(Grant Nos.2017YFA0303504 and 2017YFA0205800)+1 种基金the National Natural Science Foundation of China(Grant Nos.11304233,11674256,11674255,and 11404247)the China Postdoctoral Science Foundation(Grant No.2014T70727).
文摘Achieving larger electromagnetic enhancement using a nanogap between neighboring metallic nanostructures has been long pursued for boosting light–matter interactions.However,the quantitative probing of this enhancement is hindered by the lack of a reliable experimental method for measuring the local fields within a subnanometer gap.Here,we use layered MoS2 as a two-dimensional atomic crystal probe in nanoparticle-on-mirror nanoantennas to measure the plasmonic enhancement in the gap by quantitative surface-enhanced Raman scattering.Our designs ensure that the probe filled in the gap has a well-defined lattice orientation and thickness,enabling independent extraction of the anisotropic field enhancements.We find that the field enhancement can be safely described by pure classical electromagnetic theory when the gap distance is no<1.24 nm.For a 0.62 nm gap,the probable emergence of quantum mechanical effects renders an average electric field enhancement of 114-fold,38.4%lower than classical predictions.
基金This study was partly supported by the Bill&Melinda Gates Foun-dation(INV-005834).
文摘Control measures during the coronavirus disease 2019(COVID-19)outbreak may have limited the spread of infectious diseases.This study aimed to analyze the impact of COVID-19 on the spread of hand,foot,and mouth disease(HFMD)in China.A mathematical model was established to fit the reported data of HFMD in six selected cities in China's Mainland from 2015 to 2020.The absolute difference(AD)and relative difference(RD)between the reported incidence in 2020,and simulated maximum,minimum,or median incidence of HFMD in 2015-2019 were calculated.The incidence and R effof HFMD have decreased in six selected cities since the outbreak of COVID-19,and in the second half of 2020,the incidence and R effof HFMD have rebounded.The results show that the total attack rate(TAR)in 2020 was lower than the maximum,minimum,and median TAR fitted in previous years in six selected cities(except Changsha City).For the maximum,median,minimum fitted TAR,the range of RD(%)is 42·20-99·20%,36·35-98·41%48·35-96·23%(except Changsha City)respectively.The preventive and control measures of COVID-19 have significantly contributed to the containment of HFMD transmission.
基金Bill&Melinda Gates Foundation(INV-005834)the Science and Technology Program of Fujian Province(No:2020Y0002)Provincial Natural Science Foundation of Fujian Province(No:2020J01094).
文摘Introduction:The coronavirus disease 2019(COVID-19)pandemic recently affected Taiwan,China.This study aimed to calculate the transmissibility of COVID-19 to predict trends and evaluate the effects of interventions.Methods:The data of reported COVID-19 cases was collected from April 20 to May 26,2021,which included daily reported data(Scenario I)and reported data after adjustment(Scenario II).A susceptibleexposed-symptomatic-asymptomatic-recovered model was developed to fit the data.The effective reproductive number(Reff)was used to estimate the transmissibility of COVID-19.Results:A total of 4,854 cases were collected for the modelling.In Scenario I,the intervention has already taken some effects from May 17 to May 26(the Reff reduced to 2.1).When the Reff was set as 0.1,the epidemic was projected to end on July 4,and a total of 1,997 cases and 855 asymptomatic individuals would have been reported.In Scenario II,the interventions were projected as having been effective from May 24 to May 26(the Reff reduced to 0.4).When the Reff was set as 0.1,the epidemic was projected to end on July 1,and a total of 1,482 cases and 635 asymptomatic individuals would have been reported.Conclusion:The epidemic of COVID-19 was projected to end after at least one month,even if the most effective interventions were applied in Taiwan,China.Although there were some positive effects of intervention in Taiwan,China.
文摘Introduction:Vaccination booster shots are completely necessary for controlling breakthrough infections of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)in China.The study aims to estimate effectiveness of booster vaccines for high-risk populations(HRPs).Methods:A vaccinated Susceptible-Exposed-Symptomatic-Asymptomatic-Recovered/Removed(SEIAR)model was developed to simulate scenarios of effective reproduction number(Reff)from 4 to 6.Total number of infectious and asymptomatic cases were used to evaluated vaccination effectiveness.Results:Our model showed that we could not prevent outbreaks when covering 80%of HRPs with booster unless Reff=4.0 or the booster vaccine had efficacy against infectivity and susceptibility of more than 90%.The results were consistent when the outcome index was confirmed cases or asymptomatic cases.Conclusions:An ideal coronavirus disease 2019(COVID-19)booster vaccination strategy for HRPs would be expected to reach the initial goal to control the transmission of the Delta variant in China.Accordingly,the recommendation for the COVID-19 booster vaccine should be implemented in HRPs who are already vaccinated and could prevent transmission to other groups.
基金supported by the National Key R&D Program of China(Grant No.2017YFA0205800)the National Natural Science Foundation of China(Nos.91850207 and 11674256)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB30000000).
文摘The photothermoelectric(PTE)effect enables efficient harvesting of the energy of photogenerated hot carriers and is a promising choice for high-efficiency photoelectric energy conversion and photodetection.Recently,the PTE effect was reported in low-dimensional nanomaterials,suggesting the possibility of optimizing their energy conversion efficiency.Unfortunately,the PTE effect becomes extremely inefficient in low-dimensional nanomaterials,owing to intrinsic disadvantages,such as low optical absorption and immature fabrication methods.In this study,a giant PTE effect was observed in lightly doped p-type silicon nanoribbons caused by photogenerated hot carriers.The open-circuit photovoltage responsivity of the device was 3-4 orders of magnitude higher than those of previously reported PTE devices.The measured photovoltage responses fit very well with the proposed photothermoelectric multiphysics models.This research proposes an application of the PTE effect and a possible method for utilizing hot carriers in semiconductors to significantly improve their photoelectric conversion efficiency.
基金supported by Guangzhou Science and Technology Plan Project(Grant No.202002030245)supported by the National Natural Science Foundation of China(Grant No.31671591,31971797)+4 种基金Guangdong Province Modern Agricultural Key Technology Model Integration and Demonstration and Promotion Project(2021)Guangdong Province Modern Agricultural Industry Technology System Innovation Team Construction Special Fund(Grant No.2021KJ108)Guangdong Provincial Education Department Special Innovation Category Project(Grant No.2019KTSCX013)Guangdong Provincial Science and Technology Innovation Strategy Special Funds in 2020(“Climbing Plan”Special Funds,Grant No.pdjh2020a0084)Guangdong Provincial Students’Innovation and Entrepreneurship Project in 2020(Grant No.S202010564150)。
文摘The monocular vision-based system can obtain the leaf wall area characterizing the canopy parameter for online detection and real-time variable spraying,aiming to improve the accuracy of orchard spraying equipment and the utilization efficiency of pesticide.This study established a spraying system,in which canopy parameters were collected by monocular vision,and the spray volume decision coefficient was constructed by the leaf wall area and the L^(*)value in International Commission on Illumination Lab color space to control the duty cycle of each solenoid valve to achieve variable spraying.Four spray flow models were designed to determine the spray volume decision coefficient.The coefficients of determination of the spray volumes with the duty cycle range of 15%to 65%were all over 94 and the error of the leaf wall area values obtained using the improved super green algorithm(calculated as ExG=2.1G–1.1R–1.1B)was only 0.5%.The test showed that there is a negative relationship between canopy denseness and L^(*),and the value of L^(*)is smaller in the dense area compared with the sparse area;the actual flow generated by the system is similar to the theoretical flow when the duty cycle is 65%.The field validation tests showed that the variable spraying system could refine the droplet size and increase the droplet density to a certain extent with the same coverage rate,which had advantages over the continuous spraying.In terms of droplet deposition,DV0.1 and DV0.9 were reduced by 2μm and 18μm,respectively,and the increase of droplet density to 75 droplets/cm2.At the same time,the improvement of droplet distribution uniformity and droplet penetration by 16%and 3%,respectively.Compared with continuous spraying,variable spraying can achieve 55.64%savings.The study demonstrates the feasibility of monocular vision in guiding spraying operations and provides a reference for the use of monocular vision in plant protection operations.
基金supported by the Key R&D Program of Shandong Province(2021ZLGX02)the Education and Teaching Reform Research Project of Shandong University(2020Y118)+7 种基金the Clinical Research Center of Shandong University(no.2020SDUCRCC018,2020SDUCRCA006,and 2020 SDUCRCB003)the National Natural Science Foundation of China(81801942)supported by the National Key R&D Program of China(2020YFC1512700,2020YFC1512705,2020YFC1512703,and 2020YFC0846600)National S&T Fundamental Resources Investigation Project(2018FY100600,and 2018FY100602)Taishan Pandeng Scholar Program of Shandong Province(tspd20181220)Taishan Young Scholar Program of Shandong Province(tsqn20161065,tsqn201812129)Undergraduate Education Development Fund,Cheeloo College of Medicine,Shandong University(qlyxjy-201824)Youth Top-Talent Project of National Ten Thousand Talents Plan,and the Qilu Young Scholar Program.
文摘Together with the development of the focused assessment with sonography for trauma protocol for ultrasound in trauma patients,point-of-care ultrasound is widely used in the field of emergency and critical care medicine.Researchers have established several classic operating protocols for different diseases,such as acute respiratory failure,shock,and cardiac arrest,in the emergency department and intensive care unit.With further development in the portability and popularity of ultrasonic equipment,it is expected to be used as a new type of technology for physical examination,including inspection,palpation,percussion,auscultation,and insonation,which will improve the clinical medicine practice in the future.
基金supported by the National Key Research and Development Program of China (2021YFC2301604)Guiding projects of Science and Technology Program in Fujian Province (2019D014).
文摘After the policy adjustment,China no longer carries out COVID-19 PCR testing for all people,and antigen testing has become the main way to detect and manage infectious sources.We developed a dynamic model to evaluate and compare the effects between PCR and antigen testing for controlling the pandemic.Due to the increase of contact degree,the peak reduction effect of PCR testing in population is lower than that of antigen testing.Even if it was only 20%of people isolated at home after antigen testing,the peak of the epidemic could be reduced by 9.46%.If the proportion of antigen testing is further increased to 80%,the peak of the pandemic can be reduced by 31.41%.Antigen testing performed better effects in school(reduction proportion 29.27%)and community(29.34%)than in workplace(27.75%).Therefore,we recommend that antigen testing in the popu-lation should be encouraged during the pandemic,and home isolation of infected persons should be advocated,especially in crowded places.To improve the availability of antigen,the testing proportion should be further enhanced.
基金This work was partly supported by the Bill&Melinda Gates Foundation(INV-005834)the National Key Research and Development Program of China(2021YFC2301604)the Fujian Provincial Department of Science and Technology pilot project(2020D019).
文摘Objective:This study elaborated the natural history parameters of Delta variant,explored the differences in detection cycle thresholds(Ct)among cases.Methods:Natural history parameters were calculated based on the different onset time and exposure time of the cases.Intergenerational relationships between generations of cases were calculated.Differences in Ct values of cases by gender,age,and mode of detection were analyzed statistically to assess the detoxification capacity of cases.Results:The median incubation period was 4 days;the detection time for cases decreased from 25 to 7 h as the outbreak continued.The average generation time(GT),time interval between transmission generations(TG)and serial interval(SI)were 3.6±2.6 days,1.67±2.11 days and 1.7±3.0 days.Among the Ct values,we found little differences in testing across companies,but there were some differences in the gender of detected genes.The Ct values continuous to decreased with age,but increased when the age was greater than 60.Conclusion:This epidemic was started from aggregation of factories.It is more reasonable to use SI to calculate the effective reproduction number and the time-varying reproduction number.And the analysis of Ct values can improve the positive detection rate and improve prevention and control measures.
基金Supported by the National Key Research and Development Program of China(2021YFC2301604).
文摘Introduction:The aim of this study was to construct an assessment method for cross-regional transmission of coronavirus disease 2019(COVID-19)and to provide recommendations for optimizing measures such as interregional population movements.Methods:Taking Xi’an City as the example subject of this study’s analysis,a Cross-Regional-Gravitational-Dynamic model was constructed to simulate the epidemic in each district of Xi’an under three scenarios of controlled population movement(Scenario 1:no intensive intervention;Scenario 2:blocking Yanta District on December 18 and blocking the whole region on December 23;and Scenario 3:blocking the whole region on December 23).This study then evaluated the effects of such simulated population control measures.Results:The cumulative number of cases for the three scenarios was 8,901,425,178,and 474,respectively,and the duration of the epidemic was 175,18,and 22 days,respectively.The real world prevention and control measures in Xi’an reduced the cumulative number of cases for its outbreak by 99.98%in comparison to the simulated response in Scenario 1;in contrast,the simulated prevention and control strategies set in Scenarios 2(91.26%)and 3(76.73%)reduced cases even further than the real world measures used in Xi’an.Discussion:The constructed model can effectively simulate an outbreak across regions.Timely implementation of two-way containment and control measures in areas where spillover is likely to occur is key to stopping cross-regional transmission.
