INTRODUCTIONWith the coming of the 21st century, we are faced the problems of the environment, re-sources and population. The ocean is regarded as supplier of resources such as food, minerals,energy and space, and pla...INTRODUCTIONWith the coming of the 21st century, we are faced the problems of the environment, re-sources and population. The ocean is regarded as supplier of resources such as food, minerals,energy and space, and plays an important role in sustainable economic development. At thesame time the ocean has a very important effect on the worldwide environmental changes.展开更多
Little information is available on the prevalence of drug-resistance mutations in patients harboring the human immunodeficiency virus type 1(HIV-1) circulating recombinant form(CRF)07_BC variant in Sichuan, China. Thi...Little information is available on the prevalence of drug-resistance mutations in patients harboring the human immunodeficiency virus type 1(HIV-1) circulating recombinant form(CRF)07_BC variant in Sichuan, China. This study examined 375 plasma samples from patients with HIV-1 who were infected with the CRF07_BC strain, including 104 drug-naive participants and 271 in whom antiretroviral therapy(ART) had failed. Only one participant in the drug-naive group had a drug-resistance mutation(M46L), compared with 31.73% of those in whom ART had failed. Further analysis showed that 19.56% of strains contained mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors(NNRTIs) alone, 0.74% were resistant to nucleoside reverse transcriptase inhibitors(NRTIs) alone, and 11.44% were dual-resistant to both NRTIs and NNRTIs. The most common mutation in the ART-failure group was M184V(35.88%), K103N(45.01%), Y181C(17.33%), and G190S/A(15.88%). The percentages of HIV-1 strains resistant to lamivudine, emtricitabine, efavirenz, etravirine, and nevirapine were 10.70%, 10.70%, 28.04%, 7.75%, and 26.20%, respectively. To explore site variants possibly related to drug resistance, variations in the ancestor/consensus CRF07_BC sequences from the therapy-naive and ART-failure groups were compared, and seven mutations at six positions were identified as being significantly differently distributed between the two groups(p<0.05). Detailed sequence data will provide information on CRF07_BC genetic characterizations, and improve our understanding of antiretroviral susceptibility and the evolution of drug-resistance mutations. This will be valuable in developing and implementing local public-health approaches for HIV drug-resistance prevention and treatment.展开更多
Aim of this study was to investigate the genotypic distribution of extended-spectrum β-lactamases (ESBLs) and AmpC enzymes among Escherichia coli isolated from farm animals in Chongqing City. 326 E.coli isolates were...Aim of this study was to investigate the genotypic distribution of extended-spectrum β-lactamases (ESBLs) and AmpC enzymes among Escherichia coli isolated from farm animals in Chongqing City. 326 E.coli isolates were obtained from piglets,cattle and chickens.In these isolates,19 ESBLs and 6 AmpC-producing E.coli isolates were detected by preliminary screening and phenotypic identification, and polymerase chain reaction and sequence analysis methods were used to detect ESBLs and AmpCβ-lactamases genes.The results showed that the frequencies of TEM,CTX-M,DHA-1 and CMY-2 genes were 2.15%,5.21%,0.61%and 0.61%,respectively,in E.coli of animal origin in the Chongqing area,and 5 E.coli isolates were found to carry two kinds of genotype.The DHA-1 gene was detected for the first time in a veterinary clinic in China;its GenBank accession number is FJ386455.This study indicated that TEM and CTX-M genes were the predominant genotypes in Chongqing,and the majority of ESBLs and AmpC-producing E.coli isolates were multi-resistant to antibiotics,so they deserve particular attention in veterinary clinics.展开更多
This paper reports, for the first time, observation results of the Coherent Beacon System(CBS) onboard the China SeismoElectromagnetic Satellite-1(CSES-1). We describe the CBS, and the Computerized Ionospheric Tomogra...This paper reports, for the first time, observation results of the Coherent Beacon System(CBS) onboard the China SeismoElectromagnetic Satellite-1(CSES-1). We describe the CBS, and the Computerized Ionospheric Tomography(CIT) algorithm program is validated by numerical experiment. Two examples are shown, for daytime and nighttime respectively. The Equatorial Ionization Anomaly(EIA) can be seen, and the northern crest core is located at ～20°N in the reconstruction image at 07:28 UTC on 20 July 2018(daytime).Disturbances are shown in the reconstruction image at 18:40 UTC on 13 July 2018(nighttime). We find that beacon measurements are more consistent with ionosonde measurements than model results, by comparing Nm F2 at three sites at Lanzhou, Chongqing, and Kunming; consistency with ionosonde measurements validates beacon measurements. Finally, we have studied Vertical Total Electron Content(VTEC) variations from ground to ～500 km(the height of CSES-1 orbit) and ratios of VTEC between beacon measurements and CODE(Center for Orbit Determination in Europe) data. VTEC variation from ground to ～500 km has a range of 7.2–16.5 TECU for the daytime case and a range of 1.1–1.7 TECU for the nighttime case. The Beacon/CODE ratio of VTEC varies with latitude and time. The mean Beacon/CODE ratio is 0.69 for the daytime case and 0.26 for the nighttime case. The fact that the nighttime case yields lower ratios indicates the higher altitude of the ionosphere during nighttime when the ionosphere is assumed to be a thin layer.展开更多
Through 40 years of reform and open-up,China’s system is no longer a monocentric one of centralized control and at the same time neither is it a polycentric one,but rather it is a"1+N"centric model of gover...Through 40 years of reform and open-up,China’s system is no longer a monocentric one of centralized control and at the same time neither is it a polycentric one,but rather it is a"1+N"centric model of governance.It is a model that combines polycentric with monocentric with several centers,all of which however are centering on a mono-center.展开更多
China launched Algeria’s communications satellite,Alcomsat-1,on a LM-3B carrier rocket into its preset orbit from the Xichang Satellite Launch Center at 00:40 Beijing time on December 11 successfully.Alcomsat-1 is Al...China launched Algeria’s communications satellite,Alcomsat-1,on a LM-3B carrier rocket into its preset orbit from the Xichang Satellite Launch Center at 00:40 Beijing time on December 11 successfully.Alcomsat-1 is Algeria’s first communications satellite as well as the first cooperative project in the aerospace industry between China and Algeria.China and Algeria are展开更多
福建沿海地区第四系较为发育,是研究晚更新世以来相对海平面变化的理想区域。本文以福建宁德NDQK5岩芯中产出的高分辨率介形类化石为研究对象,结合加速器质谱法(accelerator mass spectrometry,AMS)14C和光释光测年技术建立岩芯年代框架...福建沿海地区第四系较为发育,是研究晚更新世以来相对海平面变化的理想区域。本文以福建宁德NDQK5岩芯中产出的高分辨率介形类化石为研究对象,结合加速器质谱法(accelerator mass spectrometry,AMS)14C和光释光测年技术建立岩芯年代框架,重建了中全新世期间福建沿海地区的相对海平面变化。结果显示,NDQK5岩芯中的介形类化石记录主要分布于4~17.1 m段,对应年代约为8.2~6.9 ka BP。岩芯内共计识别出海相介形类23属26种,根据优势种以及特征种的相对丰度变化特征可将岩芯内的介形类动物群划分为3个组合:①介形类组合A以Bicornucythere bisanensis和Sinocytheridea impressa为主,代表潮下带环境;②介形类组合B以Sinocytheridea impressa和Neomonoceratina delicata为优势种,指示近岸内陆架的沉积环境;③介形类组合C以Sinocytheridea impressa和Loxoconcha ocellifera为主,代表潮间带的沉积环境。基于介形类组合的分布特征,本文推断福建沿海地区海平面约在8.2~7.4 ka BP期间持续上升,并在约7.9~7.4 ka BP区间达到最高;7.4~7.0 ka BP期间海平面下降,随后再次上升。因此,介形类化石记录指示福建沿海地区在全新世高海平面背景下依然存在相对海平面的次一级波动。同时,结合已有福建沿海地区海平面变化驱动机制的研究结果,本研究推断8.2~7 ka BP期间福建沿海地区的海平面变化可能主要受控于冰盖融水;7 ka BP后该地区的海平面波动可能受控于“冰川-水均衡调整”作用。展开更多
文摘INTRODUCTIONWith the coming of the 21st century, we are faced the problems of the environment, re-sources and population. The ocean is regarded as supplier of resources such as food, minerals,energy and space, and plays an important role in sustainable economic development. At thesame time the ocean has a very important effect on the worldwide environmental changes.
基金supported by the Chinese Government AIDS Program (grant number 2008ZX001-016)the China 4th Global Fund AIDS Program (grant number CHN-405-G05-H)a Sichuan Provincial Health Department research project (number 120154)
文摘Little information is available on the prevalence of drug-resistance mutations in patients harboring the human immunodeficiency virus type 1(HIV-1) circulating recombinant form(CRF)07_BC variant in Sichuan, China. This study examined 375 plasma samples from patients with HIV-1 who were infected with the CRF07_BC strain, including 104 drug-naive participants and 271 in whom antiretroviral therapy(ART) had failed. Only one participant in the drug-naive group had a drug-resistance mutation(M46L), compared with 31.73% of those in whom ART had failed. Further analysis showed that 19.56% of strains contained mutations conferring resistance to non-nucleoside reverse transcriptase inhibitors(NNRTIs) alone, 0.74% were resistant to nucleoside reverse transcriptase inhibitors(NRTIs) alone, and 11.44% were dual-resistant to both NRTIs and NNRTIs. The most common mutation in the ART-failure group was M184V(35.88%), K103N(45.01%), Y181C(17.33%), and G190S/A(15.88%). The percentages of HIV-1 strains resistant to lamivudine, emtricitabine, efavirenz, etravirine, and nevirapine were 10.70%, 10.70%, 28.04%, 7.75%, and 26.20%, respectively. To explore site variants possibly related to drug resistance, variations in the ancestor/consensus CRF07_BC sequences from the therapy-naive and ART-failure groups were compared, and seven mutations at six positions were identified as being significantly differently distributed between the two groups(p<0.05). Detailed sequence data will provide information on CRF07_BC genetic characterizations, and improve our understanding of antiretroviral susceptibility and the evolution of drug-resistance mutations. This will be valuable in developing and implementing local public-health approaches for HIV drug-resistance prevention and treatment.
基金supported by Chongqing Natural Science Foundation(CSTC,2007BB0002)
文摘Aim of this study was to investigate the genotypic distribution of extended-spectrum β-lactamases (ESBLs) and AmpC enzymes among Escherichia coli isolated from farm animals in Chongqing City. 326 E.coli isolates were obtained from piglets,cattle and chickens.In these isolates,19 ESBLs and 6 AmpC-producing E.coli isolates were detected by preliminary screening and phenotypic identification, and polymerase chain reaction and sequence analysis methods were used to detect ESBLs and AmpCβ-lactamases genes.The results showed that the frequencies of TEM,CTX-M,DHA-1 and CMY-2 genes were 2.15%,5.21%,0.61%and 0.61%,respectively,in E.coli of animal origin in the Chongqing area,and 5 E.coli isolates were found to carry two kinds of genotype.The DHA-1 gene was detected for the first time in a veterinary clinic in China;its GenBank accession number is FJ386455.This study indicated that TEM and CTX-M genes were the predominant genotypes in Chongqing,and the majority of ESBLs and AmpC-producing E.coli isolates were multi-resistant to antibiotics,so they deserve particular attention in veterinary clinics.
基金supported by the “China Seismo-Electromagnetic Satellite (CSES)” projectthe 13th Five-Year Technology Program (Grant No. 315030409)
文摘This paper reports, for the first time, observation results of the Coherent Beacon System(CBS) onboard the China SeismoElectromagnetic Satellite-1(CSES-1). We describe the CBS, and the Computerized Ionospheric Tomography(CIT) algorithm program is validated by numerical experiment. Two examples are shown, for daytime and nighttime respectively. The Equatorial Ionization Anomaly(EIA) can be seen, and the northern crest core is located at ～20°N in the reconstruction image at 07:28 UTC on 20 July 2018(daytime).Disturbances are shown in the reconstruction image at 18:40 UTC on 13 July 2018(nighttime). We find that beacon measurements are more consistent with ionosonde measurements than model results, by comparing Nm F2 at three sites at Lanzhou, Chongqing, and Kunming; consistency with ionosonde measurements validates beacon measurements. Finally, we have studied Vertical Total Electron Content(VTEC) variations from ground to ～500 km(the height of CSES-1 orbit) and ratios of VTEC between beacon measurements and CODE(Center for Orbit Determination in Europe) data. VTEC variation from ground to ～500 km has a range of 7.2–16.5 TECU for the daytime case and a range of 1.1–1.7 TECU for the nighttime case. The Beacon/CODE ratio of VTEC varies with latitude and time. The mean Beacon/CODE ratio is 0.69 for the daytime case and 0.26 for the nighttime case. The fact that the nighttime case yields lower ratios indicates the higher altitude of the ionosphere during nighttime when the ionosphere is assumed to be a thin layer.
文摘Through 40 years of reform and open-up,China’s system is no longer a monocentric one of centralized control and at the same time neither is it a polycentric one,but rather it is a"1+N"centric model of governance.It is a model that combines polycentric with monocentric with several centers,all of which however are centering on a mono-center.
文摘China launched Algeria’s communications satellite,Alcomsat-1,on a LM-3B carrier rocket into its preset orbit from the Xichang Satellite Launch Center at 00:40 Beijing time on December 11 successfully.Alcomsat-1 is Algeria’s first communications satellite as well as the first cooperative project in the aerospace industry between China and Algeria.China and Algeria are
文摘福建沿海地区第四系较为发育,是研究晚更新世以来相对海平面变化的理想区域。本文以福建宁德NDQK5岩芯中产出的高分辨率介形类化石为研究对象,结合加速器质谱法(accelerator mass spectrometry,AMS)14C和光释光测年技术建立岩芯年代框架,重建了中全新世期间福建沿海地区的相对海平面变化。结果显示,NDQK5岩芯中的介形类化石记录主要分布于4~17.1 m段,对应年代约为8.2~6.9 ka BP。岩芯内共计识别出海相介形类23属26种,根据优势种以及特征种的相对丰度变化特征可将岩芯内的介形类动物群划分为3个组合:①介形类组合A以Bicornucythere bisanensis和Sinocytheridea impressa为主,代表潮下带环境;②介形类组合B以Sinocytheridea impressa和Neomonoceratina delicata为优势种,指示近岸内陆架的沉积环境;③介形类组合C以Sinocytheridea impressa和Loxoconcha ocellifera为主,代表潮间带的沉积环境。基于介形类组合的分布特征,本文推断福建沿海地区海平面约在8.2~7.4 ka BP期间持续上升,并在约7.9~7.4 ka BP区间达到最高;7.4~7.0 ka BP期间海平面下降,随后再次上升。因此,介形类化石记录指示福建沿海地区在全新世高海平面背景下依然存在相对海平面的次一级波动。同时,结合已有福建沿海地区海平面变化驱动机制的研究结果,本研究推断8.2~7 ka BP期间福建沿海地区的海平面变化可能主要受控于冰盖融水;7 ka BP后该地区的海平面波动可能受控于“冰川-水均衡调整”作用。
