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| 1 | Current concepts on osteonecrosis of the femoral head显示文摘It is estimated that 20000 to 30000 new patients are diagnosed with osteonecrosis annually accounting for approximately 10% of the 250000 total hip arthroplasties done annually in the United States. Thelack of level 1 evidence in the literature makes it difficult to identify optimal treatment protocols to manage patients with pre-collapse avascular necrosis of the femoral head, and early intervention prior to collapse is critical to successful outcomes in joint preserving procedures. There have been a variety of traumatic and atraumatic factors that have been identified as risk factors for osteonecrosis, but the etiology and pathogenesis still remains unclear. Current osteonecrosis diagnosis is dependent upon plain anteroposterior and frog-leg lateral radiographs of the hip, followed by magnetic resonance imaging(MRI). Generally, the first radiographic changes seen by radiograph will be cystic and sclerotic changes in the femoral head. Although the diagnosis may be made by radiograph, plain radiographs are generally insufficient for early diagnosis, therefore MRI is considered the most accurate benchmark. Treatment options include pharmacologic agents such as bisphosphonates and statins, biophysical treatments, as well as joint-preserving and joint-replacing surgeries. the surgical treatment of osteonecrosis of the femoral head can be divided into two major branches: femoral head sparing procedures(FHSP) and femoral head replacement procedures(FHRP). In general, FHSP are indicated at pre-collapse stages with minimal symptoms whereas FHRP are preferred at post-collapse symptomatic stages. It is difficult to know whether any treatment modality changes the natural history of core decompression since the true natural history of core decompression has not been delineated. | Joaquin Moya-Angeler Arianna L Gianakos Jordan C Villa Amelia Ni Joseph M Lane | 2015 | World Journal of Orthopedics2015,6,8: | 94 |
| 2 | Climate variation since the Last Interglaciation recorded in the Guliya ice core显示文摘The climatic and environmental variations since the Last Interglaciation are reconstructed based on the study of the upper 268 m of the 309-m-long Guliya ice core. Five stages can be distinguished since the Last Interglaciation from the δ18O record in the Guliya ice core: Stage 1 (Deglaciation), Stage 2 (the Last Glacial Maximum), Stage 3 (interstadial), Stage 4 (interstadial in the early glacial maximum) and Stage 5 (the Last Interglaciation). Stage 5 can be divided further into 5 substages; a, b, c, d, e. The δ18O record in the Guliya ice core indicates clearly the close correlation between the temperature variation on the Tibetan Plateau and the solar activities. The study indicates that the solar activity is a main forcing to the climatic variation on the Tibetan Plateau. Through a comparison of the ice core record in Guliya with that in the Greenland and the Antarctic, it can be found that the variation of large temperature variation events in different parts of the world is generally the same, | 姚檀栋 L.G.Thompson 施雅风 秦大河 焦克勤 杨志红 田立德 E.M.Thompson | 1997 | Science China Earth Sciences1997,40,6: | 68 |
| 3 | Osteonecrosis of the femoral head: An update in year 2012显示文摘Osteonecrosis is a phenomenon involving disruption to the vascular supply to the femoral head, resulting in articular surface collapse and eventual osteoarthritis. Although alcoholism, steroid use, and hip trauma remain the most common causes, several other etiologies for osteonecrosis have been identified. Basic science research utilizing animal models and stem cell applications continue to further elucidate the pathophysiology of osteonecrosis and promise novel treatment options in the future. Clinical studies evaluating modern joint-sparing procedures have demonstrated significant improvements in outcomes, but hip arthroplasty is still the most common procedure performed in these affected younger adults. Further advances in joint-preserving procedures are required and will be widely studied in the coming decade. | Anjan P Kaushik Anusuya Das Quanjun Cui | 2012 | World Journal of Orthopedics2012,3,5: | 68 |
| 4 | Theoretical research on construction quality real-time monitoring and system integration of core rockfill dam显示文摘With the enlargement of core rockfill dam construction scale and the improvement of construction mechanization level, the traditional manual construction quality control method is now difficult to meet the quality and safety demands of modern dam construction, so automatic and real-time dam construction quality monitoring with high-techs is urgently needed. The paper makes theoretical research on construction quality real-time monitoring and system integration of core rockfill dam, proposes implementation method and integrated solution of construction quality real-time monitoring of core rockfill dam construction process, realizes refining, all-whether, entire-process and real-time control and analysis on key links of dam construction, and introduces the application of the construction quality real-time monitoring and system integration technology to a practical core rockfill dam project. | ZHONG DengHua CUI Bo LIU DongHai TONG DaWei | 2009 | Science China(Technological Sciences)2009,52,11: | 59 |
| 5 | Abrupt climatic changes on the Tibetan Plateau during the Last Ice Age——Comparative study of the Guliya ice core with the Greenland GRIP ice core显示文摘Based on a comparative study of the Gtdiya ice core with the Greenland GRIP ice core, the abrupt climatic changes on the Tibetan Plateau during the Last Ice Age have been examined. The major stadial-interstadial events and 7 warm events (BrΦrump, Odderade, Oerel, Glinde, Hengelo, Denekamp, BΦlling) are consistent in the two ice cores. However, there are some unique features in the Guliya ice core records. The transition from warm to cold periods in the Guliya ice core is faster than that in the Greenland GRIP ice core. The magnitude of the climatic changes in the Guliya ice core is also larger than that in the Greenland GRIP ice core. Another significant feature of the Guliya ice core records is that there is a series of cycles of about 200 a from 18 to 35 kaBP. 22 warm events and 20 cold events with a fluctuation magnitude of 7℃ have been distinguished. The warm and cold events with a fluctuation magnitude within 3℃ are as high as 100. It is speculated that the abrupt climatic changes in | 姚檀栋 | 1999 | Science China Earth Sciences1999,42,4: | 49 |
| 6 | Variations in temperature and precipitation in the past 2000 a on the Xizang (Tibet) Plateau——Guliya ice core record显示文摘The past temperature and precipitation variations are recorded precisely and continuously in μ18O and glacial accumulation records in the Guliya ice core. Fight warm periods and seven cold periods can be distinguished in the past 2000 a. Of the four most intensive cold periods, three are in the Little Ice Age and one in the 11th - 12th century. The variation of precipitation is relatively small compared with that of temperature. Five humid periods and four dry periods occurred in the past 2 000 a. The long-term variation of temperature is positively correlated with that of precipitation according to the Guliya ice core record, but the variation of precipitation lags behind the variation of temperature. | 姚檀栋 L.G.Thompson 秦大河 田立德 焦克勤 杨志红 谢超 | 1996 | Science China Earth Sciences1996,39,4: | 46 |
| 7 | Decadal climatic variations recorded in Guliya ice core and comparison with the historical documentary data from East China during the last 2000 years显示文摘The high-resolution records of δ18O and snow accumulation variations from the Guliya ice core provide valuable data for research on climatic variations at a decadal resolution during the past 2000 years in China. Based on the ice core data, five spells have been divided: the warm and wet period before 270 AD, the cold and dry period between 280 and 970 AD, the moderate and dry period between 970 and 1510 AD, the well-defined' Little Ice Age 'with drastic cold-warm fluctuations between 1510 and 1930 AD and the warming period since 1930 AD. According to the combination of temperature and precipitation, cold events (55 times) surpass warm ones (26 times), and dry events (55 times) surpass wet ones (45 times). Cold-wet events (14 times) are less than cold-dry ones (16 times), while warmwet events (10 times) are more than warm-dry ones (4 times). If the difference of 2‰ in δ18O (corresponding to 3K in temperature) between two or three adjacent decades is taken as the criterion of it, the abrupt | 施雅风 姚檀栋 杨保 | 1999 | Science China Earth Sciences1999,42,S1: | 31 |
| 8 | CT引导下经皮肺穿刺对周围型肺部肿块的临床应用价值显示文摘 | 李为春 朱银喜 | 2006 | 临床肺科杂志2006,11,3: | 30 |
| 9 | 虚拟图书馆中元数据研究显示文摘元数据是虚拟图书馆建设的关键技术之一。本文从虚拟图书馆的元数据著录项目为何宜选用都柏林核心元素集 。 | 臧国全 柯平 郭少友 | 2001 | 图书馆2001,,1: | 28 |
| 10 | AN ENORMOUS THRUST NAPPE AND EXTENSIONAL METAMORPHIC CORE COMPLEX NEWLY DISCOVERED IN SINO-MONGOLIAN BOUNDARY AREA显示文摘An enormous thrust nappe and a metamorphic core complex of extensional origin have been recently discovered within the Hercynian-Indosinian orogen of Inner Mongolia. Both features are of the Mesozoic age, but the former is older. The thrust nappe strikes WNW-ESE and Proterozoic dolomite was thrust southwards atop strata ranging from the Cambrian to the Triassic in age. The visible displacement of the thrust is ca. 70 km and the deduced one is over 140 km. The metamorphic core complex (mainly mylonites) extends in an N-E direction, forming itself into a dome geometry and lying under an extensional detachment fault. The mylonitic foliation dips gently and the stretching mineral lineation, as a whole, plunges SSE. Various shear sense markers show a normal-sense shear movement. Some significant problems atise from the coexistence of nappe and extensional structures at a postoro-genic stage. | 郑亚东 王士政 王玉芳 | 1991 | Science China Chemistry1991,34,9: | 26 |
| 11 | MARC与Dublin Core之比较研究显示文摘本文简述MARC与DublinCore两种元数据的结构、特点 ,对二者进行比较 。 | 赵光林 | 2002 | 情报学报2002,21,2: | 26 |
| 12 | Genotypes and viral variants in chronic hepatitis B: A review of epidemiology and clinical relevance显示文摘The Hepatitis B Virus(HBV) has a worldwide distribu-tion and is endemic in many populations. It is constantly evolving and 10 genotypic strains have been identified with varying prevalences in different geographic regions. Numerous stable mutations in the core gene and in the su-rface gene of the HBV have also been identified in untreated HBV populations. The genotypes and viral variants have been associated with certain clinical featu-res of HBV related liver disease and Hepatocellu-lar carcinoma. For example Genotype C is associated withlater hepatitis B e antigen(HBe Ag) seroconversion, and more advanced liver disease. Genotype A is associated with a greater risk of progression to chronicity in adu-lt acqu-ired HBV infections. Genotype D is particu-larly associated with the precore mu-tation and HBe Ag negative chronic hepatitis B(CHB). The genotypes prevalent in parts of West Africa, Central and Sou-th America, E, F and H respectively, are less well stu-died. Viral variants especially the Basal Core Promotor mutation is associated with increased risk of fibrosis and cancer of the liver. Althou-gh not cu-rrently part of rou-tine clinical care, evalu-ation of genotype and viral variants may provide u-sefu-l adju-nctive information in predicting risk abou-t liver related morbidity in patients with CHB. | Catherine MN Croagh Paul V Desmond Sally J Bell | 2015 | World Journal of Hepatology2015,7,3: | 24 |
| 13 | Evidence for cold events in the early Holocene from the Guliya ice core, Tibetan Plateau,China显示文摘Evidence for the '8.2 ka cold event' has been provided mostly from the circum-North Atlantic area. However, whether this cold event occurred in other places is a key to understanding its cause. Here, we provide the evidence for the '8.2 ka cold event' from the Guliya ice core in the northwest Tibetan Plateau, and it was found that the peak cooling (-8.3-8.2 ka) in this ice core was about 7.8-10°C, which was larger than the cooling in the North Atlantic region. The primary causes for this episode were diminished solar activity and weakened thermohaline circulation. Moreover, another weak cold event, centered about 9.4 ka, was also recorded in the Guliya ice core record. These two cold events were concurrent with the ice-rafting episodes in the North Atlantic during the early Holocene, which implies that the millennial-scale climatic cyclicity might exist in the Tibetan Plateau as well as in the North Atlantic. | WANG Ninglian YAO Tandong L.G.Thompson K.A.Henderson M.E.Davis | 2002 | Chinese Science Bulletin2002,47,17: | 23 |
| 14 | Multistage Extension and Age Dating of the Xiaoqinling Metamorphic Core Complex,Central China显示文摘There are two extensional systems in the Xiaoqinling metamorphic core complex (XMCC). One is the detachment fault system developed along the peripheries of the XMCC, which extended in an ESE-WNW direction and whose upper plate moved towards the WNW. The other extensional system includes the retrograde shear zones and normal faults developed within the XMCC, which represent the collapse of the XMCC. Ar-Ar and K-Ar dating shows that the extension of the detachment fault system continued from 135 to 123 Ma, i.e. in the late stage of its evolution at about 127 Ma. The collapse represented by the extensional system within the XMCC was operative during 120-106 Ma, and its main activity occurred about 116 Ma ago. These suggest that the XMCC experienced two extensional stages in its evolution, i.e., the syn-orogenic regional extension and post-orogenic collapse extension. | ZHANG Jinjiang ZHENG Yadong | 1999 | Acta Geologica Sinica(English Edition)1999,73,2: | 22 |
| 15 | Liutex (vortex) core definition and automatic identification for turbulence vortex structures显示文摘As a milestone research in vortex identification(VI),the physical quantity of Liutex,including its forms of scalar,vector and tensor,was systematically explored and rigorously obtained as the third-generation(3G)of the vortex definition and identification methods distinguished from the first generation(1G)by vorticity and the second generation(2G)by the vortex identification(VI)criteria solely dependent on the velocity gradient tensor eigenvalues.Based on these findings,the vortex-core lines were abstracted from the well-defined Liutex,and for the first time,were automatically generated and massively visualized using computer.The distinctive characteristics of these vortex cores with the intriguing threshold-independency make them be the uniquely appropriate entity to represent and to depict the vortex structures in turbulence.The letter made use of the DNS data for the natural transition in a zero-pressure gradient flat-plate(Type-A turbulent boundary layer(TBL))and the fully-developed turbulence in a square annular duct(Type-B TBL)to demonstrate the vortex structure represented by the vortex-core lines.The 3G VI approach based on the vortex-core lines is capable of profoundly uncovering the vortex natures.Moreover,the capability of automatically identifying the vortex cores and massively visualizing the large number of vortex-core behaviors in a transient way will enable the fluid-mechanics and other related-science communities to step into a new era to explore the intrinsic natures of the centennial puzzle of turbulence and other vortex-related phenomena in future. | Hongyi Xu Xiao-shu Cai Chaoqun Liu | 2019 | Journal of Hydrodynamics2019,31,5: | 21 |
| 16 | ^(40)Ar-^(39)Ar ages of the Louzidian-Dachengzi ductile shear zone near Chifeng,Inner Mongolia and their tectonic significance显示文摘The Louzidian normal fault occurs as the eastern detachment fault of the Kalaqin metamorphic core complex. Field observations and microstructural analyses reveal that the Louzidian-Dachengzi ductile shear zone developed in its lower-plate was genetically related to sinistral strike-slips and extensional faulting. Two samples from this ductile shear zone yield 40Ar-39Ar plateau ages of 133 Ma (Bi) and 126 Ma (Kp), which are concordant with their isochron ages. The plateau age of 133 Ma (Bi) records the formation age of the ductile shear zone. The inconsistent relationship between the earlier strike-slip ductile shear zone and the later normal fault makes the Kalaqin Quasi-metamorphic core complex distinctive from Cordil-leran nietamorphic core complex. These ages provide important geochronological data for putting constraints on the formation age and genesis of such ductile shear zones. | ZHANG Xiaohui, LI Tiesheng, PU Zhiping & WANG HuiResearch Center for Mineral Resources Exploration, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100101, China Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, G | 2002 | Chinese Science Bulletin2002,47,15: | 21 |
| 17 | HBeAg negative variants and their role in the natural history of chronic hepatitis B virus infection显示文摘Molecular virology methods including polymerase chain reaction,cloning and sequencing have revolutionised our understanding of viral genome variation.In the case of hepatitis B virus(HBV),sequencing studies have identified a number of virus variants normally found during the natural course of chronic infection.The appearance of the precore stop codon(with G-for-A substitution at position 1896)and basal core promoter(BCP)(with A-for-T and G-for-A,at positions 1762 and 1764,respectively)variants which reduce or abrogate hepatitis B e antigen(HBeAg)production,heralds the initiation of the seroconversion phase from HBeAg to antiHBe positivity.The gradual removal of the tolerogenic effect of HBeAg leads to the awakening of the immune response(immune clearance phase).Most patients after HBeAg seroconversion become'inactive HBsAg carriers'.However during the course of infection precore and/or BCP variants may emerge and be selected leading to HBeAg negative chronic hepatitis B(CHB)with high viremia levels(reactivation phase).The prevalence of HBeAg negative CHB has been increasing over the last few decades and has become the commonest type of HBV infection in many countries of the world.This probably reflects the aging of existing HBV carriers and the effective prevention measures restricting new HBV infections.Frequent acute exacerbations accompanied by high viral replication,elevated alanine aminotransferase levels and histological activity are a common feature of HBeAg negative CHB leading to cirrhosis much faster than in HBeAg positive CHB patients. | Alexra Alexopoulou Peter Karayiannis | 2014 | World Journal of Gastroenterology2014,20,24: | 21 |
| 18 | Gene heterogeneity of hepatitis B virus isolates from patients with severe hepatitis B显示文摘BACKGROUND: The pathogenesis of severe hepatitis B remains unknown. Reports have indicated that hepatitis B virus (HBV) mutations are important factors in the pathogenesis of this disease. This study was to investigate the genetic heterogeneity of HBV strains from serum samples of patients with fulminant hepatitis B. METHODS: Full-length HBV genomes from 4 patients with severe hepatitis B were cloned and sequenced to observe mutations in every open reading-frame ( ORF). Serum samples of another 25 patients with severe hepatitis B, 30 patients with chronic hepatitis B, and 25 HBV carriers were collected for sequencing and comparison of mutations in preS2, preC and core promoter regions. RESULTS: Of 4 HBV full-length genome sequences, 3 had a G to A mutation at nucleotide A1896 in the preC region and 1 had double mutations of T1762-A1764 in the core promoter region. The 4 sequences showed mutations in the known B or T cell epitopes of the preS2 and C regions. For the other 3 groups, more mutations were seen in the preS2 region in the HBV isolates from the patients with severe hepatitis B than those from the patients with chronic hepatitis B and HBV carriers (P <0.01). There was a significant difference of mutations in the T cell epitope region of preS2 between the patients with severe hepatitis B and those with chronic hepatitis B or HBV carriers (P <0.01). In the preC and core promoter regions, the mutation frequencies of T1653 and C1753 were 48.0% and 24.0% respectively in the patients with severe hepatitis B, but none of these mutations were observed in the patients with chronic hepatitis B group or HBV carriers (P <0.01). The mutation frequency of T1762-A1764 was 76.0% in the patients with severe hepatitis B, 40.0% in the patients with chronic hepatitis B (P <0. 01) , and 16. 0% in the HBV carriers ( P < 0. 01). There was a significant difference in A1896 mutation between the patients with severe hepatitis B and the patients with chronic hepatitis B (P < 0. 05 ) or the HBV carriers (P<0.05). CONCLUSION: Our observations suggest that the accumulation and persistence of high frequency mutations or complex mutations may be associated with the development and deterioration of HBV infection. | Wei Wu, Yu Chen, Bing Ruan and Lan-Juan Li Hangzhou, China Department of Infectious Diseases, First Affiliated Hospital, Zhejiang University School of Medicine, Key Laboratory of Infectious Diseases of Health Ministry of China, Hangzhou 310003, China | 2005 | Hepatobiliary & Pancreatic Diseases International2005,4,4: | 20 |
| 19 | A Liutex based definition and identification of vortex core center lines显示文摘Six core issues for vortex definition and identification concern with (1) the absolute strength,(2) the relative strength,(3) the rotational axis,(4) the vortex core center,(5) the vortex core size, and (6) the vortex boundary (Liu C. 2019). However, most of the currently popular vortex identification methods, including the Q criterion, the criterion and the Acj criterion etc., are Eulerian local region-type vortex identification criteria and can only approximately identify the vortex boundary by somewhat arbitrary threshold. On the other hand, the existing Eulerian local line-type methods, which seek to extract line-type features such as vortex core line, are not entirely satisfactory since most of these methods are based on vorticity or pressure minimum that will fail in many cases. The key issue is the lack of a reasonable mathematical definition for vortex core center. To address this issue, a Liutex (previously named Rortex) based definition of vortex core center is proposed in this paper. The vortex core center, also called vortex rotation axis line here, is defined as a line where the Liutex magnitude gradient vector is aligned with the Liutex vector, which mathematically implies that the cross product of the Liutex magnitude gradient vector and the Liutex vector on the line is equal to zero. Based on this definition, a novel three-step method for extracting vortex rotation axis lines is presented. Two test cases, namely the Burgers vortex and hairpin vortices, are examined to justify the proposed method. The results demonstrate that the proposed method can successfully identify vortex rotation axis lines without any user-specified threshold, so that the proposed method is very straightforward, robust and efficient. | Yi-sheng Gao Jian-ming Liu Yi-fei Yu Chaoqun Liu | 2019 | Journal of Hydrodynamics2019,31,3: | 19 |
| 20 | Humoral and cellular immunogenecity of DNA vaccine based on hepatitis B core gene in rhesus monkeys显示文摘INTRODUCTIONHepatitis B virus (HBV) is the most commonetiologic agent for infectious liver diseases. It isestimated that there are more than 250 millionchronic HBV carriersin the world today and thereis a significant association among persistentinfection, liver cirrhosis and hepatocellularcarcinoma[1-3]. | Zu Hu Huang1 Hui Zhuang2 Shan Lu3 Ren Hua Guo1 Guo Min Xu2 Jie Cai1 Wan Fu Zhu2 1Department of Infectious Diseases. The First Affiliated Hospital of Nanjing Medical University, Nenjing 210029, Jiangsu Province. China2Faculty of Microbiology, Beijing University, Beijing 100000, China3University of Massachusetts Medical Center | 2001 | World Journal of Gastroenterology2001,7,1: | 19 |