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| 1 | Function of apoptosis and expression of the proteins Bcl-2,p53 and C-myc in the development of gastric cancer显示文摘INTRODUCTIONIn China ,the incidence and mortality of gastric cancer rank the second among all cancers. Recent development of cancer [1-20].The aim of this study was investigat the insight of apoptosis and bcl-2, p53 and C-myc protein expression in the development of gastric cancer . | An Gao Xu Shao Guang Li Ji Hong Liu Ai Hua Gan Research Laboratory of Digestive Disease,Huizhou Central People’s Hospital,Huizhou 516001,Guangdong Province,ChinaDr.An Gao Xu graduated from Guangdong Medical College in 1984.He is an associate physician-in-chief,specializing in the research and treatment of gastrointestinal and liver tumors.He has published 24 papers and 1 book. | 2001 | World Journal of Gastroenterology2001,7,3: | 91 |
| 2 | Prevalence of Nontraumatic Osteonecrosis of the Femoral Head and its Associated Risk Factors in the Chinese Population: Results from a Nationally Representative Survey显示文摘 | De-Wei Zhao Mang Yu Kai Hu Wei Wang Lei Yang Ben-Jie Wang Xiao-Hong Gao Yong-Ming Guo Yong-Qing Xu Yu-Shan Wei Si-Miao Tian Fan Yang Nan Wang Shi-Bo Huang Hui Xie Xiao-Wei Wei Hai-Shen Jiang Yu-Qiang Zang Jun Ai Yuan-Liang Chen Guang-Hua Lei Yu-Jin Li Geng Tia Zong-Sheng Li Yong Cao Li Ma | 2015 | Chinese Medical Journal2015,,21: | 151 |
| 3 | New eolian red clay sequence on the western Chinese Loess Plateau linked to onset of Asian desertification about 25 Ma ago显示文摘The expansion of inland Asia deserts has considerably influenced the environmental, social and economic activities in Asia. Aridification of inland Asia, especially timing of the initiation of Asian desertification, is a contentious topic in paleoclimatology. Late Cenozoic eolian loess-red clay sequences on the Chinese Loess Plateau, which possess abundant paleoclimatic and paleo-environmental information, can be regarded as an indicator of inland Asia desertification. Here we present a detailed magnetostratigraphic investigation of a new red clay sequence about 654 m in Zhuanglang located at the western Chinese Loess Plateau. Sedimentological, geochemical, mineralogical, and quartz morphological lines of evidence show that the red clay is of eolian origin. Magnetostratigraphic correlations indicate that this core sequence spans from 25.6 to 4.8 Ma, and typical eolian red clay appears as early as 25 Ma. This extends the lower limit of the red clay on the Chinese Loess Plateau from the previously thought early Miocene back into the late Oligocene. This new red clay record further implies that the inland Asia desertification was initiated at least by the late Oligocene. This sequence provides a unique high-resolution geological record for understanding the inland Asia desertification process since the late Oligocene. | QIANG XiaoKe AN ZhiSheng SONG YouGui CHANG Hong SUN YouBin LIU WeiGuo AO Hong DONG JiBao FU ChaoFeng WU Feng LU FengYan CAI YanJun ZHOU WeiJian CAO JunJi XU XinWen AI Li | 2011 | Science China Earth Sciences2011,54,1: | 73 |
| 4 | Epidemiological features and risk factors of sepsis-associated encephalopathy in intensive care unit patients: 2008-2011显示文摘背景 Encephalopathy 是败血的普通复杂并发症,并且它的发作能在败血的任何阶段发生并且暗示更坏的 prognosis.However ,发生,传染病学,并且这研究的联系败血的 encephalopathy 遗体 controversial.The 目的致病是为我们的回顾的学习包括了的联系败血的 encephalopathy.Methods 调查流行病学的特征和风险因素有败血的所有病人从排除 91 的 2008~2011 .After 承认了我们的特别护理单位P=0.013 ) ,在一台通风机上花了一显著地更长的时间((8. | ZHANG Li-na WANG Xiao-ting AI Yu-hang GUO Qu-lian HUANG Li LIU Zhi-yong Vao Bo | 2012 | Chinese Medical Journal2012,,5: | 70 |
| 5 | Prevalence, risk factors, clinical course, and outcome of acute kidney injury in Chinese intensive care units: a prospective cohort study显示文摘 | WEN Ying JIANG Li XU Yuan QIAN Chuan-yun LI Shu-sheng QIN Tie-he CHEN Er-zhen LIN Jian-dong AI Yu- hang WU Da-wei WANG Yu-shan SUN Ren-hua HU Zhen-jie CAO Xiang-yuan ZHOU Fa-chun HE Zhen-yang ZHOU Li-hua AN You-zhong KANG Yan MA Xiao-chun YU Xiang-you ZHAO Ming-yan XI Xiu-ming DU Bin | 2013 | Chinese Medical Journal2013,,23: | 40 |
| 6 | Effects of resource additions on species richness and ANPP in an alpine meadow community显示文摘Aims Theories based on resource additions indicate that plant species richness is mainly determined by the number of limiting resources.However,the individual effects of various limiting resources on species richness and aboveground net primary productivity(ANPP)are less well understood.Here,we analyzed potential linkages between additions of limiting resources,species loss and ANPP increase and further explored the underlying mechanisms.Methods Resources(N,P,K and water)were added in a completely randomized block design to alpine meadow plots in the Qinghai-Tibetan Plateau.Plant aboveground biomass,species composition,mean plant height and light availability were measured in each plot.Regression and analysis of variance were used to analyze the responses of these measures to the different resource-addition treatments.Important Findings Species richness decreased with increasing number of added limiting resources,suggesting that plant diversity was apparently determined by the number of limiting resources.Nitrogen was the most important limiting resource affecting species richness,whereas Pand K alone had negligible effects.The largest reduction in species richness occurred when all three elements were added in combination.Water played a different role compared with the other limiting resources.Species richness increased when water was added to the treatments with N and P or with N,P and K.The decreases in species richness after resource additions were paralleled by increases in ANPP and decreases in light penetration into the plant canopy,suggesting that increased light competitionwas responsible for the negative effects of resource additions on plant species richness. | Zhengwei Ren Qi Li Chengjin Chu Luqiang Zhao Jieqi Zhang Dexiecuo Ai Yingbo Yang Gang Wang | 2010 | Journal of Plant Ecology2010,3,1: | 40 |
| 7 | A Positioning System based on Communication Satellites and the Chinese Area Positioning System(CAPS)显示文摘The Chinese Area Positioning System(CAPS) is a positioning system based on satellite communication that is fundamentally different from the 3'G'(GPS,GLONASS and GALILEO) systems.The latter use special-purpose navigation satellites to broadcast navi-gation information generated on-board to users,while the CAPS transfers ground-generated navigation information to users via the communication satellite.In order to achieve accurate Positioning,Velocity and Time(PVT),the CAPS employs the following strategies to over-come the three main obstacles caused by using the communication satellite:(a) by real-time following-up frequency stabilization to achieve stable frequency;(b) by using a single carrier in the transponder with 36 MHz band-width to gain sufficient power;(c) by incorporating Decommissioned Geostationary Orbit communication satellite(DGEO),barometric pressure and Inclined Geostationary Orbit communication satellite(IGSO) to achieve the 3-D posi-tioning.Furthermore,the abundant transponders available on DGEO can be used to realize the large capacity of communication as well as the integrated navigation and communication.With the communication functions incorporated,five new functions appear in the CAPS:(1) combination of navigation and communication;(2) combination of navigation and high accu-racy orbit measurement;(3) combination of navigation message and wide/local area differen-tial processing;(4) combination of the switching of satellites,frequencies and codes;and(5) combination of the navigation message and the barometric altimetry.The CAPS is thereby labelled a PVT5C system of high accuracy.In order to validate the working principle and the performance of the CAPS,a trial system was established in the course of two years at a cost of about 20 million dollars.The trial constellation consists of two GEO satellites located at E87.5° and E110.5°,two DGEOs located at E130° and E142°,as well as barometric altimetry as a virtual satellite.Static and dynamic performance tests were completed for the Eastern,the Western,the Northern,the Southern and the Middle regions of China.The evaluation results are as follows:(1) land static test,plane accuracy range:C/A code,15~25m;P code,5~10 meters;altitude accuracy range,1~3 m;(2) land dynamic test,plane accuracy range,C/A code,15~25m;P code,8~10m;(3) velocity accuracy,C/A code,0.13~0.3ms-1,P code,0.15~0.17ms-1;(4) timing accuracy,C/A code,160ns,P code,13 ns;(5) timing compared accuracy of Two Way Satellite Time and Frequency Transfer(TWSTFT),average accuracy,0.068ns;(6) random error of the satellite ranging,10.7 mm;(7) orbit determination accuracy,better than 2 m.The above stated random error is 1σ error.At present,this system is used as a preliminary operational system and a complete system with 3 GEO,3 DGEO and 3 IGSO is being established. | Guo-Xiang Ai Hu-Li Shi Hai-Tao Wu Yi-Hua Yan Yu-Jing Bian Yong-Hui Hu Zhi-Gang Li Ji Guo Xian-De Cai | 2008 | Chinese Journal of Astronomy and Astrophysics2008,8,6: | 33 |
| 8 | Diver CE versus Guardwire Plus for thrombectomy in patients with inferior myocardial infarction:a trial of aspiration of thrombus during primary angioplasty for inferior myocardial infarction显示文摘背景不同可行、安全的 thrombectomy 和远侧的保护设备用 Diver CE 设备在临床的 practice.The 效率和附属物 thrombectomy 的安全被使用了( Invatec ,意大利 )对 Guardwire 正设备( Medtronic ,美国)在经皮的冠的干预(一种总线标准)与尖锐劣等的 ST-segment-elevation 心肌的梗塞( STEMI )在病人被作比较不到 12 个小时以前,在心肌的梗塞( TIMI )的 thrombolysis 流动分级 0~1 ,并且总计吸藏第二等的结束点被让结束心脏舒张的体积( LVEDV )室,左室喷射部分( LVEF )和包括死亡的主要不利心脏的事件(权标),心肌的梗塞,在 122 个病人的 30 days.Results A 总数的目标容器 revascularization 和击同等地被划分成 Diver CE 组和 Guardwire 正组,它到年龄是可比较的(( 60 ?????????汣灯摩杯敲????朠潲灵?潃据畬楳湯??湡獵? | YAN Hong-bing WANG Jian LI Nan ZHU Xiao-ling GAO Hai AI Hui LI Xiang YE Ming CHI Yun-peng ZHANG Hong | 2007 | Chinese Medical Journal2007,,7: | 29 |
| 9 | The Association of Maternal Body Composition and Dietary Intake with the Risk of Gestational Diabetes Mellitus during the Second Trimester in a Cohort of Chinese Pregnant Women显示文摘Objective To investigate the association of maternal body composition and dietary intake with the risk of gestational diabetes mellitus(GDM). Methods A total 154 GDM subjects and 981 controls were enrolled in a prospective cohort study in 11 hospitals from May 20, 2012 to December 31, 2013. Bioelectrical impedance analysis and dietary surveys were used to determine body composition and to evaluate the intake of nutrients in subjects at 21-24 weeks' gestation(WG). Logistic regression analysis was applied to explore the relationships of maternal body composition and dietary intake with the risk of GDM morbidity. Results Age, pre-pregnant body weight(BW), and body mass index(BMI) were associated with increased risk of GDM. Fat mass(FM), fat mass percentage(FMP), extracellular water(ECW), BMI, BW, energy, protein, fat, and carbohydrates at 21-24 WG were associated with an increased risk of GDM. In contrast, fat free mass(FFM), muscular mass(MM), and intracellular water(ICW) were associated with a decreased risk of GDM. Conclusion Maternal body composition and dietary intake during the second trimester of pregnancy were associated with the risk of GDM morbidity. | Xu Qing Gao Zhi Ying Li Li Ming Wang Lu Zhang Qian Teng Yue Zhao Xia Ge Sheng Jing Hong Jiang Yang Yong Tao Liu Xiao Jun Lyu Chun Jian Mao Lun Yu Xiao Ming Liu Ying Hua Kong Ai Jing Yang Xue Yan Liu Zhao Zhang Yong Wang Jin Zhang Xin Sheng Xue Chang Yong Lu Yan Ping | 2016 | Biomedical and Environmental Sciences2016,29,1: | 29 |
| 10 | Chinese Multidisciplinary Expert Consensus on the Diagnosis and Treatment of Hyperuricemia and Related Diseases显示文摘 | Zou, He-Jian Wu, Hu-Sheng Zhou, Jing-Guo Zeng, Xue-Jun Dai, Lie Wu, Hua-Xiang Zhu, Xiao-Xia Mei, Chang-Lin Hao, Chuan-Ming Chen, Nan Liu, Bi-Cheng Chen, Jiang-Hua Yang, Li Nie, Jing Yu, Chen Peng, Ai Yu, Sheng-Qiang Li, Lin Ge, Jun-Bo Huo, Yong Zhang, Shu-Yang Chen, Yun-Dai Dong, Yu-Gang Liang, Chun Dai, Yu-Xiang Gao, Xin Li, Chang-Gui Zhao, Jia-Jun Chen, Hai-Bing Cheng, Zhi-Feng Lin, Huan-Dong Guan, Yang-Tai Wang, Kai Luo, Ben-Yan Dai, Ruo-Lian Jiang, Quan Xue, Luan Liang, Chao-Chao Chen, Ming Fan, Song | 2017 | Chinese Medical Journal2017,,20: | 30 |
| 11 | Estimation of biomass in wheat using random forest regression algorithm and remote sensing data显示文摘Wheat biomass can be estimated using appropriate spectral vegetation indices.However,the accuracy of estimation should be further improved for on-farm crop management.Previous studies focused on developing vegetation indices,however limited research exists on modeling algorithms.The emerging Random Forest(RF) machine-learning algorithm is regarded as one of the most precise prediction methods for regression modeling.The objectives of this study were to(1) investigate the applicability of the RF regression algorithm for remotely estimating wheat biomass,(2) test the performance of the RF regression model,and(3) compare the performance of the RF algorithm with support vector regression(SVR) and artificial neural network(ANN) machine-learning algorithms for wheat biomass estimation.Single HJ-CCD images of wheat from test sites in Jiangsu province were obtained during the jointing,booting,and anthesis stages of growth.Fifteen vegetation indices were calculated based on these images.In-situ wheat above-ground dry biomass was measured during the HJ-CCD data acquisition.The results showed that the RF model produced more accurate estimates of wheat biomass than the SVR and ANN models at each stage,and its robustness is as good as SVR but better than ANN.The RF algorithm provides a useful exploratory and predictive tool for estimating wheat biomass on a large scale in Southern China. | Li'ai Wang Xudong Zhou Xinkai Zhu Zhaodi Dong Wenshan Guo | 2016 | The Crop Journal2016,4,3: | 30 |
| 12 | Incidence of Pleural Effusion in Patients with Pulmonary Embolism显示文摘 | Min Liu Ai Cui Zhen-Guo Zhai Xiao-Juan Guo Man Li Lei-Lei Teng Li-Li Xu Xiao-Juan Wang Zhen Wang Huan-Zhong Shi | 2015 | Chinese Medical Journal2015,,8: | 25 |
| 13 | Construction, expression and characterization of the engineered antibody against tumor surface antigen, p185^(c-erbB-2)显示文摘The c-erbB-2 proto-oncogene encodes a 185kDa protein p185, which belongs to epidermal growth factorreceptor family. Amplification of this gene has been shown to correlate with poor clinical prognosis forcertain cancer patients. The monoclonal antibody A21 which directed against p185 specifically inhibitsproliferation of tumor cells overexpressing p185, hence allows it to be a candidate for targeted therapy. Inorder to overcome several drawbacks of murine MAb, we cloned its VH and VL genes and constructed thesingle-chain Fv (scFv) through a peptide linker. The recombinant scFvA21 was expressed in Escherichiacoli and purified by the affinity column. Subsequently it was characterized by ELISA, Western blot, cellimmunohistochemistry and FACS. All these assays showed the binding activity to extracellular domain(ECD) of p185. Based on those properties of scFvA21, we further constructed the scFv-Fc fusion moleculewith a homodimer form and the recombinant product was expressed in mammalian cells. In a series ofsubsequent analysis this fusion protein showed identical antigen binding site and activity with the parentantibody. These anti-p185 engineered antibodies have promised to be further modified as a tumor targetingdrugs, with a view of application in the diagnosis and treatment of human breast cancer. | LIAN SHENG CHENG, AI PING LIU, JIA HONG YANG, YAN QIU DONG, LIANG WEI LI, JING WANG, CHAO CHEN WANG, JING LIUSchool of Life Science, University of Science and Technology of China, Hefei 230027, China | 2003 | Cell Research2003,13,1: | 24 |
| 14 | Barometric altimetry system as virtual constellation applied in CAPS显示文摘This work describes the barometric altimetry as virtual constellation applied to the Chinese Area Positioning System (CAPS), which uses the transponders of communication satellites to transfer navigation messages to users. Barometric altimetry depends on the relationship of air pressure varying with altitude in the Earth’s atmosphere. Once the air pressure at a location is measured the site altitude can be found. This method is able to enhance and improve the availability of three-dimensional positioning. The difficulty is that the relation between barometric pressure and altitude is variable in different areas and under various weather conditions. Hence, in order to obtain higher accuracy, we need to acquire the real-time air pressure corresponding to an altimetric region’s reference height. On the other hand, the altimetry method will be applied to satellite navigation system, but the greatest difficulty lies in how to get the real-time air pressure value at the reference height in the broad areas overlaid by satellite navigation. We propose an innovational method to solve this problem. It is to collect the real-time air pressures and temperatures of the 1860 known-altitude weather observatories over China and around via satellite communication and to carry out time extrapolation forecast uniformly. To reduce data quantity, we first partition the data and encode them and then broadcast these information via navigation message to CAPS users’ receivers. Upon the interpolations being done in receivers, the reference air pressure and temperature at the receiver’s nearby place is derived. Lastly, combing with the receiver-observed real air pressure and temperature, the site’s altitude can be determined. The work is presented in the following aspects: the calculation principle, formulae, data collection, encoding, prediction, interpolation method, navigation message transmission together with errors causes and analyses. The advantages and shortcomings of the technique are discussed at the end. | AI GuoXiang SHENG PeiXuan DU JinLin ZHENG YongGuang CAI XianDe WU HaiTao HU YongHui HUA Yu LI XiaoHui | 2009 | Science China(Physics,Mechanics & Astronomy)2009,52,3: | 22 |
| 15 | Induction of apoptosis of human gastric carcinoma SGC-7901 cell line by 5,7-dihydroxy-8-nitrochrysin in vitro显示文摘AIM: To investigate the effect of 5, 7-dihydroxy-8- nitrochrysin (NOChR) on apoptosis of human gastric carcinoma SGC-7901 cell line. METHODS: SGC-7901 cells were cultured in vitro and the inhibitory effect of NOChR on proliferation of SGC-7901 cells was measured by using an MTT assay. NOChR-induced apoptosis rate of SGC-7901 cells was detected using flow cytometry (FCM) with PI staining. DNA ladder bands were observed by DNA agarose gel electrophoresis. The influence of NOChR on the proxisome proliferator-activated receptor-γ (PPARγ), Bcl-2 and Bax protein expression of SGC-7901 cells was analyzed by Western blot. RESULTS: MTT assay showed that NOChR markedly inhibited proliferation of SGC-7901 cells in a dose- dependent manner, and when IC50 was 4.14 μmol/L, the potency of NOChR was 10 times than that of lead compound, chrysin (ChR, IC50 was 40.56 μmol/L), and was similar to 5-fluorouracil (5-FU, IC50 was 4.51 μmol/L). FCM with propidium iodide (PI) staining demonstrated that the apoptosis rates of SGC-7901 cells treated with 1.25, 5.00 and 20.00 μmol/L NOChR for 48 h were 9.8% ± 0.2%, 36.8% ± 1.9% and 45.5% ± 3.5%, respectively, and were significantly higher when treated with 5.00 and 20.00 μmol/L NOChR than that with 20.00 μmol/L ChR (12.9% ± 1.5%). DNA agarose gel electrophoresis showed that treatment of SGC-7901 cells with 20.00 μmol/L NOChR for 48 h resulted in typical DNA ladder bands of DNA of SGC-7901 cells, which could be eliminated by treating with 10.00 μmol/L GW9662, a blocker of PPARγ. Western blot analysis revealed that after 24 h of treatment with 20.00 μmol/L NOChR, PPARgamma and Bax protein expression of SGC-7901 cells increased but Bcl-2 expression decreased; however, pre-incubation with 10.00 μmol/L GW9662 could efficiently antagonize and weaken the regulatory effect of 20.00 μmol/L NOChR on Bax and Bcl-2 protein expression of SGC-7901 cells. CONCLUSION: NOChR induces apoptosis of SGC-7901 cell lines by activating PPARγ and decreasing ratio of Bcl-2 to Bax. | Xiao-Hong Ai Xing Zheng Xiao-Qing Tang Li Sun Yang-Qin Zhang Yong Qin Hua-Qing Liu Hong Xia Jian-Guo Cao | 2007 | World Journal of Gastroenterology2007,13,28: | 22 |
| 16 | Report on Childhood Obesity in China (9): Sugar-sweetened Beverages Consumption and Obesity显示文摘Objective To explore the associations between sugar-sweetened beverage (SSB) consumption and obesity as well as obesity-related cardiometabolic disorders among children in China. Methods A total of 6974 (boys 3558, girls 3412) children aged 6-13 years participated in the study. Each participant's height, weight, waist circumference, fasting glucose, triglycerides, total cholesterol, high- density lipoprotein cholesterol, and low-density lipoprotein cholesterol were measured. The type of beverage consumption was determined using a self-administered questionnaire. Results SSBs were consumed regularly by 46.1% of the children. The prevalence [adjusted odds ratio (95% confidence internal (CI)] of obesity was 7.6% [as the reference group (ref.)], 10.1% [1.36(1.07, 1.74)], and 11.6% [1.46(1.21, 1.75)], among children who regularly drank milk, other beverages and SSBs, respectively. Regularly drinking SSBs elevated the likelihood of abdominal obesity [adjusted odds ratio (95% CI): 1.36 (1.17, 1.59)]. The prevalence [adjusted odds ratio (95% CI)] of obesity among children who regularly drank sports/caloric beverages, carbonated beverages, sweet tea, and plant protein beverages was 16.8% [2.00(1.31, 3.07)], 12.7% [1.52(1.23, 1.88)], 11.5% [1.52(1.18, 1.95)], and 10.4% [1.41(1.03, 1.94)], respectively, which was higher than that of regular milk drinkers [7.6 % (ref.)]. The prevalence [adjusted odds ratio (95% CI)] of abdominal obesity among children who regularly drank sweet tea, fruit/vegetable juices, and carbonated beverages was 17.7% [1.55(1.26, 1.90)], 16.2% [1.36(1.09, 1.70)], and 15.3% [1.24(1.03, 1.50)], respectively, which was much higher than that of regular milk drinkers [12.8% (ref.)]. Conclusions Regular SSB consumption was positively related to obesity and abdominal obesity. This relationship should be investigated further using a longitudinal study design. | SHANG Xian Wen LIU Ai Ling ZHANG Qian HU Xiao Qi DU Song Ming MA Jun XU Gui Fa LI Ying GUO Hong Wei DU Lin LI Ting Yu MA Guan Sheng | 2012 | Biomedical and Environmental Sciences2012,25,2: | 23 |
| 17 | Osteoimmunomodulatory effects of biomaterial modification strategies on macrophage polarization and bone regeneration显示文摘Biomaterials as bone substitutes are always considered as foreign bodies that can trigger host immune responses.Traditional designing principles have been always aimed at minimizing the immune reactions by fabricating inert biomaterials.However,clinical evidence revealed that those methods still have limitations and many of which were only feasible in the laboratory.Currently,osteoimmunology,the very pioneering concept is drawing more and more attention-it does not simply regard the immune response as an obstacle during bone healing but emphasizes the intimate relationship of the immune and skeletal system,which includes diverse cells,cytokines,and signaling pathways.Properties of biomaterials like topography,wettability,surface charge,the release of cytokines,mediators,ions and other bioactive molecules can impose effects on immune responses to interfere with the skeletal system.Based on the bone formation mechanisms,the designing methods of the biomaterials change from immune evasive to immune reprogramming.Here,we discuss the osteoimmunomodulatory effects of the new modification strategies—adjusting properties of bone biomaterials to induce a favorable osteoimmune environment.Such strategies showed potential to benefit the development of bone materials and lay a solid foundation for the future clinical application. | Yajuan Xie Cheng Hu Yi Feng Danfeng Li Tingting Ai Yulei Huang Xiaodan Chen Lijia Huang Jiali Tan | 2020 | Regenerative Biomaterials2020,7,3: | 22 |
| 18 | The principle of the positioning system based on communication satellites显示文摘It is a long dream to realize the communication and navigation functionality in a satellite system in the world. This paper introduces how to establish the system, a positioning system based on communication satellites called Chinese Area Positioning System (CAPS). Instead of the typical navigation satellites, the communication satellites are configured firstly to transfer navigation signals from ground stations, and can be used to obtain service of the positioning, velocity and time, and to achieve the function of navigation and positioning. Some key technique issues should be first solved; they include the accuracy position determination and orbit prediction of the communication satellites, the measur- ing and calculation of transfer time of the signals, the carrier frequency drift in communication satellite signal transfer, how to improve the geometrical configuration of the constellation in the system, and the integration of navigation & communication. Several innovative methods are developed to make the new system have full functions of navigation and communication. Based on the development of crucial techniques and methods, the CAPS demonstration system has been designed and developed. Four communication satellites in the geosynchronous orbit (GEO) located at 87.5°E, 110.5°E, 134°E, 142°E and barometric altimetry are used in the CAPS system. The GEO satellites located at 134°E and 142°E are decommissioned GEO (DGEO) satellites. C-band is used as the navigation band. Dual frequency at C1=4143.15 MHz and C2=3826.02 MHz as well as dual codes with standard code (CA code and precision code (P code)) are adopted. The ground segment consists of five ground stations; the master station is in Lintong, Xi’an. The ground stations take a lot of responsibilities, including monitor and management of the operation of all system components, determination of the satellite position and prediction of the satellite orbit, accomplishment of the virtual atomic clock measurement, transmission and receiving navigation signals to and from each satellite. In the north, the south, the east, the west and the center of Chinese main land, the function of CAPS demonstration system is checked and measured. In cars and on board the system is also checked and measured. The results are as follow: CA-code, horizontal positioning accuracy, 15-25 m (1σ), vertical, 1-3 m; P-code, horizontal positioning accuracy, 8-10 m (1σ), vertical, 1-3 m; velocity accuracy, CA-code, 0.13-0.30 m/s, P-code, 0.15-0.17 m/s; time accuracy, CA-code, 160 ns, P-code, 13 ns; determination accuracy of orbit ≤2 m. About 20 million US $ and two years are spent for the development of demonstration. A complete CAPS system is now being established. | AI GuoXiang SHI HuLi WU HaiTao LI ZhiGang GUO Ji | 2009 | Science China(Physics,Mechanics & Astronomy)2009,52,3: | 21 |
| 19 | Expression of regulating apoptosis gene and apoptosis index in primary liver cancer显示文摘INTRODUCTIONProgramed cell death plays an important role in thegenesis of cancer.Certain cancer genes canregulate apoptosis.Recently,several proteins thatare structurally related to Bcl-2,an inhibitor ofapoptosis,have been identified.Therefore,novel strategies and agents that target specificmolecular pathways,as well as triggering a | Hong Yu Xu You Lin Yang Xi Li Guan Guang Song Ai Min Jiang Li Jun Shi | 2000 | World Journal of Gastroenterology2000,6,5: | 21 |
| 20 | 3D reconstruction method and connectivity rules of fracture networks generated under different mining layouts显示文摘In current research,a series of triaxial tests,which were employed to simulate three typical mining layouts(i.e.,top-coal caving,non-pillar mining and protected coal seam mining),were conducted on coal by using MTS815 Flex Test GT rock mechanics test system,and the fracture networks in the broken coal samples were qualitatively and quantitatively investigated by employing CT scanning and 3D reconstruction techniques.This work aimed at providing a detail description on the micro-structure and fractureconnectivity characteristics of rupture coal samples under different mining layouts.The results show that:(i)for protected coal seam mining layout,the coal specimens failure is in a compression-shear manner and oppositely,(ii)the tension-shear failure phenomenon is observed for top-coal caving and non-pillar mining layouts.By investigating the connectivity features of the generated fractures in the direction ofσ_1,under different mining layouts,it is found that the connectivity level of the fractures of the samples corresponding to non-pillar mining layout was the highest. | Zhang Ru Ai Ting Li Hegui Zhang Zetian Liu Jianfeng | 2013 | International Journal of Mining Science and Technology2013,23,6: | 18 |