In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a n...In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world’s attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development;we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control(including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.展开更多
The mutation status of KRAS is a significant biomarker in the prognosis of rectal cancer.This study investigated the feasibility of MRI-based radiomics in predicting the mutation status of KRAS with a composite index ...The mutation status of KRAS is a significant biomarker in the prognosis of rectal cancer.This study investigated the feasibility of MRI-based radiomics in predicting the mutation status of KRAS with a composite index which could be an important criterion for KRAS mutation in clinical practice.In this retrospective study,a total of 127 patients with rectal cancer were enrolled.The 3D Slicer was used to extract the radiomics features from the MRI images,and sparse support vector machine(SVM)with linear kernel was applied for feature reduction.The radiomics classifier for predicting the KRAS status was then constructed by Linear Discriminant Analysis(LDA)and its performance was evaluated.The composite index was determined with LDA model.Out of 127 rectal cancer subjects,there were 44 KRAS mutation cases and 83 wild cases.A total of 104 radiomics features were extracted,54 features were filtered by linear SVM with L1-norm regularization and 6 features that had no significant correlations within them were finally selected.The radiomics classifier constructed using the 6 features featured an AUC value of 0.669(specificity:0.506;sensitivity:0.773)with LDA.Furthermore,the composite index(Radscore)had statistically significant difference between the KRAS mutation and wild groups.It is suggested that the MRI-based radiomics has the potential in predicting the KRAS status in patients with rectal cancer,which may enhance the diagnostic value of MRI in rectal cancer.展开更多
BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tu...BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tumor. However, the treatment response is observed only in a fraction of patients due to the partial radiological response secondary to stabilization of abnormal vessels which does not essentially indicate a true antitumor effect. Perfusion-weighted magnetic resonance imaging(PWMRI) techniques have shown implicitness as a strong imaging biomarker for gliomas since they give hemodynamic information of blood vessels. Hence, there is a rapid expansion of PW-MRI related studies and clinical applications.AIM To determine the diagnostic performance of PW-MRI techniques including:(A)dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI); and(B)dynamic susceptibility contrast magnetic resonance imaging(DSC-MRI) for evaluating response to antiangiogenic therapy in patients with recurrent gliomas.METHODS Databases such as PubMed(MEDLINE included), EMBASE, and Google Scholar were searched for relevant original articles. The included studies were assessed for methodological quality with the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Medical imaging follow-up or histopathological analysis was used as the reference standard. The data were extracted by two reviewers independently, and then the sensitivity, specificity, summary receiver operating characteristic curve, area under the curve(AUC), and heterogeneity were calculated using Meta-Disc 1.4 software.RESULTS This study analyzed a total of six articles. The overall sensitivity for DCE-MRI and DSC-MRI was 0.69 [95% confidence interval(CI): 0.53-0.82], and the specificity was 0.99(95%CI: 0.93-1) by a random effects model(DerSimonianeeLaird model). The likelihood ratio(LR) +, LR-, and diagnostic odds ratio(DOR)were 12.84(4.54-36.28), 0.35(0.22-0.53), and 24.44(7.19-83.06), respectively. The AUC(± SE) was 0.9921(± 0.0120), and the Q* index(± SE) was 0.9640(± 0.0323).For DSC-MRI, the sensitivity was 0.73, the specificity was 0.98, the LR+ was 7.82,the LR-was 0.32, the DOR was 31.65, the AUC(± SE) was 0.9925(± 0.0132), and the Q* index was 0.9649(± 0.0363). For DCE-MRI, the sensitivity was 0.41, the specificity was 0.97, the LR+ was 5.34, the LR-was 0.71, the DOR was 8.76, the AUC(± SE) was 0.9922(± 0.2218), and the Q* index was 0.8935(± 0.3037).CONCLUSION This meta-analysis demonstrated a beneficial value of PW-MRI(DSC-MRI and DCE-MRI) in monitoring the response of recurrent gliomas to antiangiogenic therapy, with reasonable sensitivity, specificity, +LR, and-LR.展开更多
2019新型冠状病毒(2019 novel coronavirus,2019-nCoV)感染的肺炎,因2019年12月发生在武汉的不明原因病毒性肺炎病例而被发现,并于2020年1月12日被世界卫生组织(World Health Organization,WHO)命名。在之后的一个月时间内,2019-nCoV在...2019新型冠状病毒(2019 novel coronavirus,2019-nCoV)感染的肺炎,因2019年12月发生在武汉的不明原因病毒性肺炎病例而被发现,并于2020年1月12日被世界卫生组织(World Health Organization,WHO)命名。在之后的一个月时间内,2019-nCoV在湖北省内外甚至其他国家传播造成了数以千计的病例出现,同时也引起了民众一定程度的恐慌。本指南的制订希望能够从疾病流行病学、病因学、诊断、治疗、护理、医院感染控制等方面给临床医生、社区居民等提供医疗护理及居家照护相关指导。展开更多
This paper presents the design,fabrication,and characterization of a quartz tuning fork temperature sensor based on a new ZY-cut quartz crystal bulk acoustic wave resonator vibrating in a flexural mode.Design and perf...This paper presents the design,fabrication,and characterization of a quartz tuning fork temperature sensor based on a new ZY-cut quartz crystal bulk acoustic wave resonator vibrating in a flexural mode.Design and performance analysis of the quartz tuning fork temperature sensor were conducted and the thermal sensing characteristics were examined by measuring the resonance frequency shift of this sensor caused by an external temperature.Finite element method is used to analyze the vibratory modes and optimize the structure of the sensor.The sensor prototype was successfully fabricated and calibrated in operation from 0 to 100 ℃ with the thermo-sensitivity of 70×10-6/℃.Experimental results show that the sensor has high thermo-sensitivity,good stability,and good reproducibility.This work presents a high-precision low-power temperature sensor using the comprehensive thermal characterization of the ZY-cut quartz tuning fork resonator.展开更多
Body size is the most important economic trait for animal production and breeding.Several hundreds of loci have been reported to be associated with growth trait and body weight in chickens.The loci are mapped to large...Body size is the most important economic trait for animal production and breeding.Several hundreds of loci have been reported to be associated with growth trait and body weight in chickens.The loci are mapped to large genomic regions due to the low density and limited number of genetic markers in previous studies.Herein,we employed comparative population genomics to identify genetic basis underlying the small body size of Yuanbao chicken(a famous ornamental chicken)based on 89 whole genomes.The most significant signal was mapped to the BMP10 gene,whose expression was upregulated in the Yuanbao chicken.Overexpression of BMP10 induced a significant decrease in body length by inhibiting angiogenic vessel development in zebrafish.In addition,three other loci on chromosomes 1,2,and 24 were also identified to be potentially involved in the development of body size.Our results provide a paradigm shift in identification of novel loci controlling body size variation,availing a fast and efficient strategy.These loci,particularly BMP10,add insights into ongoing research of the evolution of body size under artificial selection and have important implications for future chicken breeding.展开更多
Silica aerogels are widely used in many fields for thermal insulation,such as building insulation,electric power energy,energy storage systems,and high-temperature thermal protection due to their excellent insulation ...Silica aerogels are widely used in many fields for thermal insulation,such as building insulation,electric power energy,energy storage systems,and high-temperature thermal protection due to their excellent insulation per-formance.Therefore,the heat transfer in silica aerogels and its modeling in recent years have attracted much attention and many valuable achievements have been acquired.The heat transfer in nano-porous silica aerogels and its modeling methods are reviewed in this work.This review starts with a brief introduction of heat transfer characteristics in silica aerogels,including the multi-component and multi-mode coupling effect,size effect,and multiscale effect.Then the heat transfer mechanism of each mode,including heat transfer via gas phase,solid phase,and thermal radiation,is reviewed,and the models for predicting the gaseous thermal conductivity in nanoscale pores,gas-contributed thermal conductivity,the apparent thermal conductivity of solid skeleton,and finally the effective thermal conductivity are collected and discussed in details.Besides,modeling of transient heat transfer in silica aerogels is also briefly introduced.Finally,the conclusions and some problems which need to be further investigated in the future are provided.展开更多
The spatial-dependent propagation(SDP)model has been demonstrated to account for the spectral hardening of both primary and secondary Cosmic Rays(CRs)nuclei above about 200 GV.In this work,we further apply this model ...The spatial-dependent propagation(SDP)model has been demonstrated to account for the spectral hardening of both primary and secondary Cosmic Rays(CRs)nuclei above about 200 GV.In this work,we further apply this model to the latest AMS-02 observations of electrons and positrons.To investigate the effect of different propagation models,both homogeneous diffusion and SDP are compared.In contrast to the homogeneous diffusion,SDP brings about harder spectra of background CRs and thus enhances background electron and positron fluxes above tens of GeV.Thereby,the SDP model could better reproduce both electron and positron energy spectra when introducing a local pulsar.The influence of the background source distribution is also investigated,where both axisymmetric and spiral distributions are compared.We find that considering the spiral distribution leads to a larger contribution of positrons for energies above multi-GeV than the axisymmetric distribution.In the SDP model,when including a spiral distribution of sources,the all-electron spectrum above TeV energies is thus naturally described.In the meantime,the estimated anisotropies in the all-electrons spectrum show that in contrary to the homogeneous diffusion model,the anisotropy under SDP is well below the observational limits set by the Fermi-LAT experiment,even when considering a local source.展开更多
基金supported(in part)by the Entrusted Project of National Center for Medical Service Administration,National Health and Family Planning Commission China(No.[2019]099)the First Level Funding of the Second Medical Leading Talent Project in Hubei Provincethe Special Project for Emergency of the Ministry of Science and Technology(2020YFC0841300)。
文摘In December 2019, a new type viral pneumonia cases occurred in Wuhan, Hubei Province;and then named "2019 novel coronavirus(2019-nCoV)" by the World Health Organization(WHO) on 12 January 2020. For it is a never been experienced respiratory disease before and with infection ability widely and quickly, it attracted the world’s attention but without treatment and control manual. For the request from frontline clinicians and public health professionals of 2019-nCoV infected pneumonia management, an evidence-based guideline urgently needs to be developed. Therefore, we drafted this guideline according to the rapid advice guidelines methodology and general rules of WHO guideline development;we also added the first-hand management data of Zhongnan Hospital of Wuhan University. This guideline includes the guideline methodology, epidemiological characteristics, disease screening and population prevention, diagnosis, treatment and control(including traditional Chinese Medicine), nosocomial infection prevention and control, and disease nursing of the 2019-nCoV. Moreover, we also provide a whole process of a successful treatment case of the severe 2019-nCoV infected pneumonia and experience and lessons of hospital rescue for 2019-nCoV infections. This rapid advice guideline is suitable for the first frontline doctors and nurses, managers of hospitals and healthcare sections, community residents, public health persons, relevant researchers, and all person who are interested in the 2019-nCoV.
文摘The mutation status of KRAS is a significant biomarker in the prognosis of rectal cancer.This study investigated the feasibility of MRI-based radiomics in predicting the mutation status of KRAS with a composite index which could be an important criterion for KRAS mutation in clinical practice.In this retrospective study,a total of 127 patients with rectal cancer were enrolled.The 3D Slicer was used to extract the radiomics features from the MRI images,and sparse support vector machine(SVM)with linear kernel was applied for feature reduction.The radiomics classifier for predicting the KRAS status was then constructed by Linear Discriminant Analysis(LDA)and its performance was evaluated.The composite index was determined with LDA model.Out of 127 rectal cancer subjects,there were 44 KRAS mutation cases and 83 wild cases.A total of 104 radiomics features were extracted,54 features were filtered by linear SVM with L1-norm regularization and 6 features that had no significant correlations within them were finally selected.The radiomics classifier constructed using the 6 features featured an AUC value of 0.669(specificity:0.506;sensitivity:0.773)with LDA.Furthermore,the composite index(Radscore)had statistically significant difference between the KRAS mutation and wild groups.It is suggested that the MRI-based radiomics has the potential in predicting the KRAS status in patients with rectal cancer,which may enhance the diagnostic value of MRI in rectal cancer.
文摘BACKGROUND It is of vital importance to find radiologic biomarkers that can accurately predict treatment response. Usually, the initiation of antiangiogenic therapy causes a rapid decrease in the contrast enhancing tumor. However, the treatment response is observed only in a fraction of patients due to the partial radiological response secondary to stabilization of abnormal vessels which does not essentially indicate a true antitumor effect. Perfusion-weighted magnetic resonance imaging(PWMRI) techniques have shown implicitness as a strong imaging biomarker for gliomas since they give hemodynamic information of blood vessels. Hence, there is a rapid expansion of PW-MRI related studies and clinical applications.AIM To determine the diagnostic performance of PW-MRI techniques including:(A)dynamic contrast-enhanced magnetic resonance imaging(DCE-MRI); and(B)dynamic susceptibility contrast magnetic resonance imaging(DSC-MRI) for evaluating response to antiangiogenic therapy in patients with recurrent gliomas.METHODS Databases such as PubMed(MEDLINE included), EMBASE, and Google Scholar were searched for relevant original articles. The included studies were assessed for methodological quality with the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Medical imaging follow-up or histopathological analysis was used as the reference standard. The data were extracted by two reviewers independently, and then the sensitivity, specificity, summary receiver operating characteristic curve, area under the curve(AUC), and heterogeneity were calculated using Meta-Disc 1.4 software.RESULTS This study analyzed a total of six articles. The overall sensitivity for DCE-MRI and DSC-MRI was 0.69 [95% confidence interval(CI): 0.53-0.82], and the specificity was 0.99(95%CI: 0.93-1) by a random effects model(DerSimonianeeLaird model). The likelihood ratio(LR) +, LR-, and diagnostic odds ratio(DOR)were 12.84(4.54-36.28), 0.35(0.22-0.53), and 24.44(7.19-83.06), respectively. The AUC(± SE) was 0.9921(± 0.0120), and the Q* index(± SE) was 0.9640(± 0.0323).For DSC-MRI, the sensitivity was 0.73, the specificity was 0.98, the LR+ was 7.82,the LR-was 0.32, the DOR was 31.65, the AUC(± SE) was 0.9925(± 0.0132), and the Q* index was 0.9649(± 0.0363). For DCE-MRI, the sensitivity was 0.41, the specificity was 0.97, the LR+ was 5.34, the LR-was 0.71, the DOR was 8.76, the AUC(± SE) was 0.9922(± 0.2218), and the Q* index was 0.8935(± 0.3037).CONCLUSION This meta-analysis demonstrated a beneficial value of PW-MRI(DSC-MRI and DCE-MRI) in monitoring the response of recurrent gliomas to antiangiogenic therapy, with reasonable sensitivity, specificity, +LR, and-LR.
文摘2019新型冠状病毒(2019 novel coronavirus,2019-nCoV)感染的肺炎,因2019年12月发生在武汉的不明原因病毒性肺炎病例而被发现,并于2020年1月12日被世界卫生组织(World Health Organization,WHO)命名。在之后的一个月时间内,2019-nCoV在湖北省内外甚至其他国家传播造成了数以千计的病例出现,同时也引起了民众一定程度的恐慌。本指南的制订希望能够从疾病流行病学、病因学、诊断、治疗、护理、医院感染控制等方面给临床医生、社区居民等提供医疗护理及居家照护相关指导。
基金Project (No. 11551074) supported by the Science Research Fund of Heilongjiang Provincial Education Department,China
文摘This paper presents the design,fabrication,and characterization of a quartz tuning fork temperature sensor based on a new ZY-cut quartz crystal bulk acoustic wave resonator vibrating in a flexural mode.Design and performance analysis of the quartz tuning fork temperature sensor were conducted and the thermal sensing characteristics were examined by measuring the resonance frequency shift of this sensor caused by an external temperature.Finite element method is used to analyze the vibratory modes and optimize the structure of the sensor.The sensor prototype was successfully fabricated and calibrated in operation from 0 to 100 ℃ with the thermo-sensitivity of 70×10-6/℃.Experimental results show that the sensor has high thermo-sensitivity,good stability,and good reproducibility.This work presents a high-precision low-power temperature sensor using the comprehensive thermal characterization of the ZY-cut quartz tuning fork resonator.
基金This work was supported by the National Natural Science Foundation of China (31671325 and 31271339). N.O.O. thanks the CAS-TWAS President's Fellowship Program for Doctoral Candidates for support.
基金supported by grants from the National Natural Science Foundation of China(91331104)the 973 Program(2013CB835200,2013CB835204)Bureau of Science and Technology of Yunnan Province(2015FA026)。
文摘Body size is the most important economic trait for animal production and breeding.Several hundreds of loci have been reported to be associated with growth trait and body weight in chickens.The loci are mapped to large genomic regions due to the low density and limited number of genetic markers in previous studies.Herein,we employed comparative population genomics to identify genetic basis underlying the small body size of Yuanbao chicken(a famous ornamental chicken)based on 89 whole genomes.The most significant signal was mapped to the BMP10 gene,whose expression was upregulated in the Yuanbao chicken.Overexpression of BMP10 induced a significant decrease in body length by inhibiting angiogenic vessel development in zebrafish.In addition,three other loci on chromosomes 1,2,and 24 were also identified to be potentially involved in the development of body size.Our results provide a paradigm shift in identification of novel loci controlling body size variation,availing a fast and efficient strategy.These loci,particularly BMP10,add insights into ongoing research of the evolution of body size under artificial selection and have important implications for future chicken breeding.
基金supported by the National Natural Science Foundation of China(Grant Nos.:52006243 and 51776158)the Natural Science Foundation of Shandong Province(Grant No.:ZR2020QE197)+1 种基金Qingdao Postdoctoral Application Research Project(Grant No.:qdyy20190093)the Fundamental Research Funds for the Central Universities(Grant No.:20CX06055A).
文摘Silica aerogels are widely used in many fields for thermal insulation,such as building insulation,electric power energy,energy storage systems,and high-temperature thermal protection due to their excellent insulation per-formance.Therefore,the heat transfer in silica aerogels and its modeling in recent years have attracted much attention and many valuable achievements have been acquired.The heat transfer in nano-porous silica aerogels and its modeling methods are reviewed in this work.This review starts with a brief introduction of heat transfer characteristics in silica aerogels,including the multi-component and multi-mode coupling effect,size effect,and multiscale effect.Then the heat transfer mechanism of each mode,including heat transfer via gas phase,solid phase,and thermal radiation,is reviewed,and the models for predicting the gaseous thermal conductivity in nanoscale pores,gas-contributed thermal conductivity,the apparent thermal conductivity of solid skeleton,and finally the effective thermal conductivity are collected and discussed in details.Besides,modeling of transient heat transfer in silica aerogels is also briefly introduced.Finally,the conclusions and some problems which need to be further investigated in the future are provided.
基金Supported by the National Key Research and Development Program of China(2016YFA0400200)the National Natural Science Foundation of China(11875264,11635011,11761141001,11663006)。
文摘The spatial-dependent propagation(SDP)model has been demonstrated to account for the spectral hardening of both primary and secondary Cosmic Rays(CRs)nuclei above about 200 GV.In this work,we further apply this model to the latest AMS-02 observations of electrons and positrons.To investigate the effect of different propagation models,both homogeneous diffusion and SDP are compared.In contrast to the homogeneous diffusion,SDP brings about harder spectra of background CRs and thus enhances background electron and positron fluxes above tens of GeV.Thereby,the SDP model could better reproduce both electron and positron energy spectra when introducing a local pulsar.The influence of the background source distribution is also investigated,where both axisymmetric and spiral distributions are compared.We find that considering the spiral distribution leads to a larger contribution of positrons for energies above multi-GeV than the axisymmetric distribution.In the SDP model,when including a spiral distribution of sources,the all-electron spectrum above TeV energies is thus naturally described.In the meantime,the estimated anisotropies in the all-electrons spectrum show that in contrary to the homogeneous diffusion model,the anisotropy under SDP is well below the observational limits set by the Fermi-LAT experiment,even when considering a local source.