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Reappraisement and refinement of zircon U-Pb isotope and trace element analyses by LA-ICP-MS 被引量:1110
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作者 LIU YongSheng HU ZhaoChu +4 位作者 ZONG KeQing GAO ChangGui GAO Shan XU Juan CHEN HaiHong 《Chinese Science Bulletin》 SCIE EI CAS 2010年第15期1535-1546,共12页
A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The... A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The obtained U-Pb ages for zircon standards GJ-1,TEMORA and SK10-2 are consistent with the preferred values within about 1% uncertainty (2σ) by simple external calibration against zircon standard 91500.Different data reduction softwares could yield different uncertainties for calculation of U-Pb ages.The commercially available program GLITTER4.4 could apply an improper uncertainty calculation strategy,but it may yield artificial high precisions for single analyses.Our trace element analyses indicate that Si is not an ideal internal standard for zircon when calibrated against the NIST glasses.Calibration against the NIST glasses using Si as an internal standard,a systematic deviation of 10% 30% was found for most trace elements including Zr.However,the trace element compositions of zircon can be accurately measured by calibration against multiple reference materials with natural compositions (e.g.,BCR-2G,BHVO-2G and BIR-1G),or calibration against NIST SRM 610 and using Zr as an internal standard.Analyses of two pieces of GJ-1 demonstrate that it is relatively homogenous for most trace elements (except for Ti). 展开更多
关键词 PB同位素 微量元素 元素分析 ICP MS法 锆石 LA 固体火箭发动机
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Characterization of microRNAs in serum: a novel class of biomarkers for diagnosis of cancer and other diseases 被引量:985
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作者 Xi Chen Yi Ba +26 位作者 Lijia Ma Xing Cai Yuan Yin Kehui Wang Jig ang Guo Yujing Zhang Jiangning Chen Xing Guo Qibin Li Xiaoying Li Wenjing Wang Yan Zhang Jin Wang Xueyuan Jiang Yang Xiang Chen Xu Pingping Zheng Juanbin Zhang Ruiqiang Li Hongjie Zhang Xiaobin Shang Ting Gong Guang Ning Jun Wang Ke Zen Junfeng Zhang Chen-Yu Zhang 《Cell Research》 SCIE CAS CSCD 2008年第10期997-1006,共10页
Dysregulated expression of microRNAs (miRNAs) in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and o... Dysregulated expression of microRNAs (miRNAs) in various tissues has been associated with a variety of diseases, including cancers. Here we demonstrate that miRNAs are present in the serum and plasma of humans and other animals such as mice, rats, bovine fetuses, calves, and horses. The levels of miRNAs in serum are stable, reproducible, and consistent among individuals of the same species. Employing Solexa, we sequenced all serum miRNAs of healthy Chinese subjects and found over 100 and 91 serum miRNAs in male and female subjects, respectively. We also identified specific expression patterns of serum miRNAs for lung cancer, colorectal cancer, and diabetes, providing evidence that serum miRNAs contain fingerprints for various diseases. Two non-small cell lung cancer-specific serum miRNAs obtained by Solexa were further validated in an independent trial of 75 healthy donors and 152 cancer patients, using quantitative reverse transcription polymerase chain reaction assays. Through these analyses, we conclude that serum miRNAs can serve as potential biomarkers for the detection of various cancers and other diseases. 展开更多
关键词 serum-microRNA expression profile FINGERPRINT blood-based biomarker Solexa CANCERS diabetes
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Current cancer situation in China:good or bad news from the 2018 Global Cancer Statistics? 被引量:890
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作者 Rui-Mei Feng Yi-Nan Zong +1 位作者 Su-Mei Cao Rui-Hua Xu 《Cancer Communications》 SCIE 2019年第1期202-213,共12页
Cancer is the leading cause of death in China and depicting the cancer pattern of China would provide basic knowhows on how to tackle it more effectively.In this study we have reviewed several reports of cancer burden... Cancer is the leading cause of death in China and depicting the cancer pattern of China would provide basic knowhows on how to tackle it more effectively.In this study we have reviewed several reports of cancer burden,including the Global cancer statistics 2018 and Cancer statistics in China,2015,along with the GLOBCAN 2018 online database,to investigate the differences of cancer patterns between China,the United States(USA)and the United Kingdom(UK).An estimated 4.3 million new cancer cases and 2.9 million new cancer deaths occurred in China in 2018.Compared to the USA and UK,China has lower cancer incidence but a 30%and 40%higher cancer mortality than the UK and USA,among which 36.4%of the cancer-related deaths were from the digestive tract cancers(stomach,liver,and esophagus cancer)and have relatively poorer prognoses.In comparison,the digestive cancer deaths only took up≤5%of the total cancer deaths in either USA or UK.Other reasons for the higher mortality in China may be the low rate of early-stage cancers at diagnosis and non-uniformed clinical cancer treatment strategies performed by different regions.China is undergoing the cancer transition stage where the cancer spectrum is changing from developing country to developed country,with a rapidly increase cancer burden of colorectal,prostate,female breast cancers in addition to a high occurrence of infection-related and digestive cancers.The incidence of westernized lifestyle-related cancers in China(i.e.colorectal cancer,prostate,bladder cancer)has risen but the incidence of the digestive cancers has decreased from 2000 to 2011.An estimated 40%of the risk factors can be attributed to environmental and lifestyle factors either in China or other developed countries.Tobacco smoking is the single most important carcinogenic risk factor in China,contributing to~24.5%of cancers in males.Chronic infection is another important preventable cancer contributor which is responsible for~17%of cancers.Comprehensive prevention and control strategies in China should inc 展开更多
关键词 GLOBCAN 2018 Cancer pattern China USA UK Carcinogenic risk factor Tobacco smoking Chronic infection Westernized lifestyles Cancer control strategies
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Petrogenesis of Mesozoic granitoids and volcanic rocks in South China: A response to tectonic evolution 被引量:731
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作者 Xinmin Zhou Tao Sun +2 位作者 Weizhou Shen Liangshu Shu Yaoling Niu 《Episodes》 SCIE 2006年第1期26-33,共8页
This paper summarizes the new results on the petrogenesis of Mesozoic granitoids and volcanic rocks in South China. The authors propose that these rocks were formed in time and space as a response to regional tectonic... This paper summarizes the new results on the petrogenesis of Mesozoic granitoids and volcanic rocks in South China. The authors propose that these rocks were formed in time and space as a response to regional tectonic regime change from the continent-continent collision of the Indosinian orogeny within the broad Tethyan orogenic domain in the Early Mesozoic (T1-T3) (Period Ⅰ) to the largely extensional setting as a result of the Yanshanian orogeny genetically associated with the NW-WNW-ward subduction of the paleo-Pacific oceanic lithosphere in the Late Mesozoic (J2-K2) (Period Ⅱ). Of the Period I Indosinian granitoids, the early (T1-T2^1) ones are syn-collisional, and formed in a compressional setting; the late (T2^2-T3) ones are latecollisional, and formed in a locally extensional environment. During the Period Ⅱ Yanshanian magmatism, the Early Yanshanian (J2-J3) granitoid-volcanic rocks, which are distributed mainly in the Nanling Range and in the interior of the South China tectonic block (SCB), are characteristic of rift-type intraplate magmatism, whereas the Late Yanshanian K1 granitoidovolcanic rocks are interpreted as genetically representing active continental margin magmatism. The K2 tholeiitic basalts interlayered with red beds are interpreted as genetically associated with the development of back-arc extensional basins in the interior of the SCB. The Yanshanian granitoid-volcanic rocks are distributed widely in South China, reflecting extensional tectonics within much of the SCB. The extension-induced deep crustal melting and underplating of mantle-derived basaltic melts are suggested as the two principal driving mechanisms for the Yanshanian granitic magmatism in South China. 展开更多
关键词 SOUTHEASTERN CHINA CRUSTAL EVOLUTION JAPANESE ISLANDS GEOCHEMISTRY MAGMATISM ASIA ND CONSTRAINTS SUBDUCTION ACCRETION
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Management of hepatitis B in China 被引量:661
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作者 LU Feng-min ZHUANG Hui 《Chinese Medical Journal》 SCIE CAS CSCD 2009年第1期3-4,共2页
Hepatitis B virus (HBV) infection is a global public health problem. According to the data of WorldHealth Organization (WHO), 2 billion people worldwide have been infected with HBV, and among them 350400 million a... Hepatitis B virus (HBV) infection is a global public health problem. According to the data of WorldHealth Organization (WHO), 2 billion people worldwide have been infected with HBV, and among them 350400 million are chronic HBV carriers. Hepatitis B causes about 1 million deaths of HBV related liver failure, cirrhosis, and hepatocellular carcinoma annually. 展开更多
关键词 HBV 乙肝病毒 乙型肝炎 肝硬变
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Future Physics Programme of BESⅢ 被引量:543
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作者 M.Ablikim M.N.Achasov +147 位作者 P.Adlarson S.Ahmed M.Albrecht M.Alekseev A.Amoroso F.F.An Q.An Y.Bai O.Bakina R.Baldini Ferroli Y.Ban K.Begzsuren J.V.Bennett N.Berger M.Bertani D.Bettoni F.Bianchi J Biernat J.Bloms I.Boyko R.A.Briere L.Calibbi H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin J.Chai J.F.Chang W.L.Chang J.Charles G.Chelkov Chen G.Chen H.S.Chen J.C.Chen M.L.Chen S.J.Chen Y.B.Chen H.Y.Cheng W.Cheng G.Cibinetto F.Cossio X.F.Cui H.L.Dai J.P.Dai X.C.Dai A.Dbeyssi D.Dedovich Z.Y.Deng A.Denig Denysenko M.Destefanis S.Descotes-Genon F.De Mori Y.Ding C.Dong J.Dong L.Y.Dong M.Y.Dong Z.L.Dou S.X.Du S.I.Eidelman J.Z.Fan J.Fang S.S.Fang Y.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.Q.Feng M.Fritsch C.D.Fu Y.Fu Q.Gao X.L.Gao Y.Gao Y.Gao Y.G.Gao Z.Gao B.Garillon I.Garzia E.M.Gersabeck A.Gilman K.Goetzen L.Gong W.X.Gong W.Gradl M.Greco L.M.Gu M.H.Gu Y.T.Gu A.Q.Guo F.K.Guo L.B.Guo R.P.Guo Y.P.Guo A.Guskov S.Han X.Q.Hao F.A.Harris K.L.He F.H.Heinsius T.Held Y.K.Heng Y.R.Hou Z.L.Hou H.M.Hu J.F.Hu T.Hu Y.Hu G.S.Huang J.S.Huang X.T.Huang X.Z.Huang Z.L.Huang N.Huesken T.Hussain W.Ikegami Andersson W.Imoehl M.Irshad Q.Ji Q.P.Ji X.B.Ji X.L.Ji H.L.Jiang X.S.Jiang X.Y.Jiang J.B.Jiao Z.Jiao D.P.Jin S.Jin Y.Jin T.Johansson N.Kalantar-Nayestanaki X.S.Kang R.Kappert M.Kavatsyuk B.C.Ke I.K.Keshk T.Khan A.Khoukaz P.Kiese R.Kiuchi R.Kliemt L. 《Chinese Physics C》 SCIE CAS CSCD 2020年第4期I0001-I0004,1-102,共106页
There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B fac... There has recently been a dramatic renewal of interest in hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like XYZ states at BESⅢ and B factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related X(1835) meson state at BESⅢ, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESⅢ during the remaining operation period of BEPCⅡ. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCⅡ to higher luminosity. 展开更多
关键词 MESON HADRON optimization
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子宫颈环形电切术在子宫颈上皮内瘤变治疗中的价值 被引量:470
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作者 樊庆泊 Tay Sun Kuie 沈铿 《中华妇产科杂志》 CAS CSCD 北大核心 2001年第5期271-274,共4页
目的 探讨宫颈环形电切术 (LEEP)治疗宫颈上皮内瘤变 (CIN)的效果以及宫颈标本边缘受累与否与预后的关系。方法 采用阴道镜辅助下的宫颈环形电切术 ,对 135例CIN患者进行治疗并对其疗效进行回顾性分析。结果 本研究中 ,患者中位年龄... 目的 探讨宫颈环形电切术 (LEEP)治疗宫颈上皮内瘤变 (CIN)的效果以及宫颈标本边缘受累与否与预后的关系。方法 采用阴道镜辅助下的宫颈环形电切术 ,对 135例CIN患者进行治疗并对其疗效进行回顾性分析。结果 本研究中 ,患者中位年龄为 42岁 (18~ 6 7岁 ) ,中位妊娠次数2 2次 (0~ 8次 )。根据宫颈细胞学涂片检查结果 ,诊断为重度鳞状上皮内瘤变 (HGSIL)占 6 5 9% ,阴道镜诊断亦与上述结果类似 (75 6 % )。LEEP术后病理检查结果阴性者 7例 (5 2 % ) ;人乳头状瘤病毒(HPV)感染者 2例 (1 5 % ) ;CINⅠ级 (CINⅠ ) 15例 (11 1% ) ;HGSIL 10 8例 (80 0 % ) ,其中CINⅡ级 (CINⅡ ) 2 0例 (14 8% ) ,CINⅢ级 (CINⅢ ) 88例 (6 5 2 % ) ;宫颈微小浸润癌 3例 (2 2 % )。 78例 (5 7 8% )宫颈标本边缘病理学检查未见CIN病变 ;5 7例 (4 2 2 % )宫颈标本边缘CIN病变检测阳性或不能确定 (指由于电灼对细胞的破坏 ,影响了LEEP术后标本边缘的病理诊断 ) ,其中HGSIL 5 4例 (94 7% )。在 2 1例(15 6 % )宫颈标本边缘CIN病变检测阳性和 36例 (2 6 7% )宫颈标本边缘病理学检查不能确定患者中 ,CIN病变残留患者分别为 1例 (4 8% )和 3例 (8 3% ) ,复发患者分别为 1例 (4 8% )和 2例(5 6 % ) ;而在 78例宫颈? 展开更多
关键词 电外科手术 子宫颈上皮内瘤样病变 手术中并发症 局部肿瘤复发
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个性化推荐系统的研究进展 被引量:437
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作者 刘建国 周涛 汪秉宏 《自然科学进展》 北大核心 2009年第1期1-15,共15页
互联网技术的迅猛发展把我们带进了信息爆炸的时代.海量信息的同时呈现,一方面使用户很难从中发现自己感兴趣的部分,另一方面也使得大量少人问津的信息成为网络中的"暗信息",无法被一般用户获取.个性化推荐系统通过建立用户... 互联网技术的迅猛发展把我们带进了信息爆炸的时代.海量信息的同时呈现,一方面使用户很难从中发现自己感兴趣的部分,另一方面也使得大量少人问津的信息成为网络中的"暗信息",无法被一般用户获取.个性化推荐系统通过建立用户与信息产品之间的二元关系,利用已有的选择过程或相似性关系挖掘每个用户潜在感兴趣的对象,进而进行个性化推荐,其本质就是信息过滤.个性化推荐系统不仅在社会经济中具有重要的应用价值,而且也是一个非常值得研究的科学问题.事实上,它是目前解决信息过载问题最有效的工具.文中根据推荐算法的不同,分别介绍了协同过滤系统,基于内容的推荐系统,混合推荐系统,以及最近兴起的基于用户—产品二部图网络结构的推荐系统.并结合这些推荐系统的特点以及存在的缺陷,提出了改进的方法和未来可能的若干研究方向.推荐系统的研究受到了信息科学、计算数学、统计物理学、认知科学等多学科的关注,它与管理科学、消费行为等研究也密切相关.能够为不同学科领域的科研工作者研究推荐系统提供借鉴,有助于我国学者了解该领域的主要进展. 展开更多
关键词 推荐系统 个性化推荐 协同过滤 基于内容的推荐 基于网络的推荐
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中国植被和土壤碳贮量 被引量:383
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作者 李克让 王绍强 曹明奎 《中国科学(D辑)》 CSCD 北大核心 2003年第1期72-80,共9页
应用0.5°经纬网格分辨率的气候、土壤和植被数据驱动的生物地球化学模型估算了当前中国植被和土壤的碳贮量.结果表明,中国陆地生态系统植被和土壤总碳贮量分别为13.33和82.65 Gt,分别为全球植被和土壤碳贮量的3%和4%,平均植被和... 应用0.5°经纬网格分辨率的气候、土壤和植被数据驱动的生物地球化学模型估算了当前中国植被和土壤的碳贮量.结果表明,中国陆地生态系统植被和土壤总碳贮量分别为13.33和82.65 Gt,分别为全球植被和土壤碳贮量的3%和4%,平均植被和土壤碳密度分别为1.47和9.17 kg/m2.它们受气候、植被和土壤类型等影响,区域差异明显,其总趋势是暖湿的东南区大于西北干旱区.最高植被碳密度出现在温暖的东南和西南地区,而最高土壤碳密度出现在寒冷的东北地区和青藏高原东南缘.这些空间类型决定于由气候状况所控制的植物生产力和土壤有机质分解速率,表明植被和土壤碳密度由不同的气候因素所控制. 展开更多
关键词 中国 植被 土壤 碳贮量 生物地球化学模型 碳密度 陆地生态系统 气候变化
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极高强度他汀治疗对冠状动脉粥样硬化消退的影响——ASTEROID试验 被引量:347
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作者 Steven E. Nissen Stephen J. Nicholls +16 位作者 Ilks Sipahi Peter Libby Joel S. Raichlen Christie M. Ballantyne Jean Davignon Raimund Erbel Jean Charles Fruchart Jean-Claude Tardif Paul Schoenhagen Tim Crowe Valerie Cain Kathy Wolski Marlene Coormastic E. Murat Tuzcu 仝其广(译) 王淑敏(译) 胡大一(校) 《美国医学会杂志(中文版)》 2006年第4期215-223,共9页
背景:以前的血管内超声(intravascular ultrasound,IVUS)试验证实,他汀治疗可减缓或阻止动脉粥样硬化的进展,但是迄今尚无应用动脉粥样斑块体积百分比(percent atheroma volume,PAV)证实粥样硬化消退的确切证据。PAV是最严格... 背景:以前的血管内超声(intravascular ultrasound,IVUS)试验证实,他汀治疗可减缓或阻止动脉粥样硬化的进展,但是迄今尚无应用动脉粥样斑块体积百分比(percent atheroma volume,PAV)证实粥样硬化消退的确切证据。PAV是最严格的评价病变进展和消退的IVUS测量指标。 目标:评价极高强度他汀治疗是否能逆转IVUS确定的冠状动脉粥样硬化。 设计和地点:于美国、加拿大、欧洲和澳大利亚53个社区和3级保健中心进行前瞻性开标盲法终点试验(A Study to Evaluate the Effect of Rosuvastatin on Intravascular Ultrasound-Derived Coronary Atheroma Burden,ASTEROID)。应用马达驱动回撤IVUS评价基线和治疗24个月时冠状动脉粥样斑块负荷。每对基线和随访IVUS测量结果均进行盲法分析。 病例:从2002年11月到2003年10月,507例患者有基线IVUS检查结果,并接受至少1个剂量的研究药物。在24个月后,349例患者具有可用于评估的系列IVUS检查结果。 干预:所有患者均接受瑞舒伐他汀40ms/d强化治疗。 主要观测指标:预先设定了两个一级疗效指标:PAV变化和基线最严重病变10min节段动脉粥样斑块体积变化。二级疗效指标为整个动脉标准化总斑块体积的变化。结果:平均(SD)LDL—C水平由基线时的130.4(34.3)ms/dL降至60.8(20.0)ms/扎,平均下降了53.2%(P〈0.001)。平均(SD)HDL-C水平从基线时的43.1(11.1)ms/dL升至49.0(12.6)ms/dL,平均增加了14.7%(P〈0.001)。整个血管PAV平均(SD)变化为-0.98%(3.15%),中位数为-0.79%(97.5%CI,-1.21%~-0.53%)(与基线比较,P〈0.001)。最严重病变10min节段斑块体积平均(SD)变化为-6.1(10.1)mm^3,中位数为-5.6mm^3(97.5%CI,-6.8~-4.0mm^3)(与基线比较,P〈0.001)。总斑块体积变化中位数降低了6.8%,� 展开更多
关键词 冠状动脉粥样硬化 瑞舒伐他汀 强化治疗 斑块消退 冠状动脉粥样斑块 INTRAVASCULAR 试验 强度 ROSUVASTATIN 冠心病患者
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Cancer incidence,mortality,and burden in China:a time-trend analysis and comparison with the United States and United Kingdom based on the global epidemiological data released in 2020 被引量:346
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作者 Haibo Qiu Sumei Cao Ruihua Xu 《Cancer Communications》 SCIE 2021年第10期1037-1048,共12页
Background:Cancer is one of the leading causes of death and a main economic burden in China.Investigating the differences in cancer patterns and control strategies between China and developed countries could provide r... Background:Cancer is one of the leading causes of death and a main economic burden in China.Investigating the differences in cancer patterns and control strategies between China and developed countries could provide reference for policy planning and contribute to improving cancer control measures.In this study,we reviewed the rates and trends of cancer incidence and mortality and disability-adjusted life year(DALY)burden in China,and compared them with those in the United States(US)and the United Kingdom(UK).Methods:Cancer incidence,mortality,and DALY data for China,US and UK were obtained fromtheGLOBOCAN2020 online database,Global Burden of Disease(GBD)2019 study,and Cancer Incidence in Five Continents plus database(CI5 plus).Trends of cancer incidence and mortality in China,US,and UK were analyzed using Joinpoint regression models to calculate annual percent changes(APCs)and identify the best-fitting joinpoints.Results:An estimated 4,568,754 newly diagnosed cancer cases and 3,002,899 cancer deaths occurred in China in 2020.Additionally,cancers resulted in 67,340,309 DALYs in China.Compared to the US and UK,China had lower cancer incidence but higher cancer mortality andDALY rates.Furthermore,the cancer spectrum of China was changing,with a rapid increase incidence and burden of lung,breast,colorectal,and prostate cancer in addition to a high incidence and heavy burden of liver,stomach,esophageal,and cervical cancer.Conclusions:The cancer spectrum of China is changing from a developing country to a developed country.Population aging and increase of unhealthy lifestyles would continue to increase the cancer burden of China.Therefore,the Chinese authorities should adjust the national cancer control program with reference to the practices of cancer control which have been well-established in the developed countries,and taking consideration of the diversity of cancer types by of different regions in China at the same time. 展开更多
关键词 cancer pattern incidence MORTALITY disability-adjusted life year trend risk factor GLOBOCAN 2020 China United States United Kingdom
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Physical activity as a treatment of non-alcoholic fatty liver disease:A systematic review 被引量:330
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作者 Maureen Whitsett Lisa B VanWagner 《World Journal of Hepatology》 CAS 2015年第16期2041-2052,共12页
AIM: To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease(NAFLD) and potential benefits in treating insulin resistance and atherosclerosis.METHODS: Medline(EBSCOhost) and Pub Med w... AIM: To review the effectiveness of exercise as a therapy for nonalcoholic fatty liver disease(NAFLD) and potential benefits in treating insulin resistance and atherosclerosis.METHODS: Medline(EBSCOhost) and Pub Med were searched for English-language randomized controlled trials and prospective cohort studies in human adults aged ≥ 18 which investigated the various effects of exercise alone, a combination of exercise and diet, or exercise and diet coupled with behavioral modification on NAFLD from 2010 to Feburary 2015.RESULTS: Eighteen of 2298 available studies were chosen for critical review, which included 6925 patients. Nine(50%) studies were randomized controlled trials. Five(27.8%) studies utilized biopsy to examine the effects of physical activity on hepatic histology. The most commonly employed imaging modality to determine change in hepatic steatosis was hydrogen-magnetic resonance spectroscopy. Only two studies examined the effects of low impact physical activity for patients with significant mobility limitations and one compared the efficacy of aerobic and resistance exercise. No studies examined the exact duration of exercise required for hepatic and metabolic improvement in NAFLD.CONCLUSION: While exercise improved hepatic steatosis and underlying metabolic abnormalities in NAFLD, more studies are needed to define the most beneficial form and duration of exercise treatment. 展开更多
关键词 NONALCOHOLIC FATTY LIVER DISEASE Nonalcoholicsteatohepatitis FATTY LIVER EXERCISE OBESITY
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新疆北部石炭纪-二叠纪独特的构造-成矿作用:对古亚洲洋构造域南部大地构造演化的制约 被引量:313
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作者 肖文交 韩春明 +8 位作者 袁超 陈汉林 孙敏 林寿发 厉子龙 毛启贵 张继恩 孙枢 李继亮 《岩石学报》 SCIE EI CAS CSCD 北大核心 2006年第5期1062-1076,共15页
新疆北部晚古生代独特的构造-成矿作用以发育大量石炭纪-二叠纪构造-成矿事件为特征,其中包括:(1)发育于晚石炭世-二叠世的阿尔泰岛弧及其变质事件、阿尔泰麻粒岩与基性杂岩、西南天山放射虫硅质岩和高压-超高压-低压麻粒岩相变质事件;... 新疆北部晚古生代独特的构造-成矿作用以发育大量石炭纪-二叠纪构造-成矿事件为特征,其中包括:(1)发育于晚石炭世-二叠世的阿尔泰岛弧及其变质事件、阿尔泰麻粒岩与基性杂岩、西南天山放射虫硅质岩和高压-超高压-低压麻粒岩相变质事件;(2)北疆发育的石炭纪(-二叠世)埃达克岩-高镁安山岩-富Nd玄武质岩组合、阿拉斯加型基性-超基性杂岩和大量的与俯冲相关的钙碱性岩浆活动与斑岩型铜矿床成矿作用;(3)天山晚石炭世晚期蛇绿岩与岛弧火山岩等。结合北疆地区相关的前陆盆地发育不明显、碰撞型花岗岩欠发育与大量发育平行造山带大型走滑构造等现象,可以认为新疆北部在石炭纪-二叠纪挤压-伸展-走滑并存,岩浆活动与成矿作用活跃。这些新进展表明新疆北部在晚石炭世-二叠纪可能仍存在活动陆缘,因此,古亚洲洋构造域南部复杂增生造山作用最后延至晚石炭世晚期-二叠纪。 展开更多
关键词 新疆北部 石炭纪-二叠世构造-成矿事件 古亚洲洋构造南部
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农村减贫:应该更关注教育还是健康?——基于收入增长和差距缩小双重视角的实证 被引量:315
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作者 程名望 Jin Yanhong +1 位作者 盖庆恩 史清华 《经济研究》 CSSCI 北大核心 2014年第11期130-144,共15页
基于2003-2010年全国农村固定观察点微观住户数据,运用分位数回归方法,从收入增长与差距缩小的双重视角研究了健康与教育对中国农户贫困的影响。研究发现:2003-2010年间,中国农村贫困发生率呈现逐年降低的趋势,这一趋势主要得益于农户... 基于2003-2010年全国农村固定观察点微观住户数据,运用分位数回归方法,从收入增长与差距缩小的双重视角研究了健康与教育对中国农户贫困的影响。研究发现:2003-2010年间,中国农村贫困发生率呈现逐年降低的趋势,这一趋势主要得益于农户收入增长,而不是收入差距缩小。健康与教育所体现的人力资本是影响农户收入水平的显著因素,对农村减贫具有显著作用。但从收入差距缩小视角看,健康对农村减贫的作用比教育更为显著。坚持提升农村人力资本积累的基本战略取向,特别是提高贫困农户健康水平,对于农村减贫具有较强的政策意义。 展开更多
关键词 健康 教育 贫困 分位数回归
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再论南岭燕山早期花岗岩的成因类型与构造意义 被引量:305
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作者 李献华 李武显 李正祥 《科学通报》 EI CAS CSCD 北大核心 2007年第9期981-991,共11页
中国东南部南岭地区广泛出露的燕山早期(侏罗纪)花岗岩与稀有金属成矿作用有非常密切的关系,这些花岗岩以弱过铝质黑云母二长花岗岩和黑云母钾长花岗岩为主,并和一些规模较小的含角闪石花岗岩和含白云母±石榴子石的浅色花岗岩在时... 中国东南部南岭地区广泛出露的燕山早期(侏罗纪)花岗岩与稀有金属成矿作用有非常密切的关系,这些花岗岩以弱过铝质黑云母二长花岗岩和黑云母钾长花岗岩为主,并和一些规模较小的含角闪石花岗岩和含白云母±石榴子石的浅色花岗岩在时-空上密切共生.在以往的文献中,这些黑云母花岗岩一般被认为是陆壳改造型(相当于S型)花岗岩,是区域元古代变质沉积岩重熔的产物.对南岭燕山早期一些代表性花岗岩的岩石化学特征和SiO2-P2O5相关关系进行了系统的分析研究,结果显示这些花岗岩的SiO2-P2O5均呈明显的负相关关系,表明南岭燕山早期的含角闪石花岗闪长岩-黑云母二长花岗岩-黑云母钾长花岗岩-二(白)云母花岗岩为准铝质-弱过铝质的I型/分异I型花岗岩演化系列,其源岩主要为元古代火成岩,少量新生地壳和/或地幔分异物质很可能参与了花岗岩的形成.同时,这些I型/分异I型花岗岩在时空上和A型酸性、基性火山/侵入岩以及碱性岩密切共生,构成了一个比较典型的板内非造山火成岩组合,反映了燕山早期南岭及邻区大陆岩石圈以伸展背景为主. 展开更多
关键词 花岗岩 成因分类 燕山早期 南岭 华南 岩石圈伸展
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基于POI数据的广州零售商业中心热点识别与业态集聚特征分析 被引量:295
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作者 陈蔚珊 柳林 梁育填 《地理研究》 CSSCI CSCD 北大核心 2016年第4期703-716,共14页
商业中心是城市零售活动的重要载体,优化商业资源在城市内部空间的合理配置,摸清不同零售经营形态的区位选择,显得尤为重要。以面向公众服务的商业机构兴趣点(POI)数据为研究对象,提出一种城市商业中心与零售业态集聚区识别的方法;以广... 商业中心是城市零售活动的重要载体,优化商业资源在城市内部空间的合理配置,摸清不同零售经营形态的区位选择,显得尤为重要。以面向公众服务的商业机构兴趣点(POI)数据为研究对象,提出一种城市商业中心与零售业态集聚区识别的方法;以广州市为例,分析商业活动的热点地区以及零售业态集聚区的空间分布特征。研究表明:1根据核密度估计法提取的商业中心在等级上表现出由城市中心圈层向外围圈层扩散的趋势,结果符合客观事实。2以街区为单元,商业网点密度符合局域Getis-Ord G*指数统计特征的热点区域主要分布在越秀区和天河区,广州市零售业发展的双核心空间格局已经形成。3不同的零售业态对商业集聚的区位选择具有显著差异性,百货商店、超市、便利店等零售经营形态的空间集聚特征与该业态的市场定位、经营模式及选址策略基本吻合。总体来看,基于POI数据的广州零售业集聚空间分析结果能够反映实体零售企业行为与广州商业经济分布的相关性,有助于提高政府部门商业规划和零售商选址前期研究的客观性和科学性。 展开更多
关键词 POI数据 商业中心识别 零售业态 集聚特征 广州
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长江中下游地区铜金(钼)矿Re-Os年龄测定及其对成矿作用的指示 被引量:279
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作者 毛景文 Holly STEIN +5 位作者 杜安道 周涛发 梅燕雄 李永峰 藏文栓 李进文 《地质学报》 EI CAS CSCD 北大核心 2004年第1期121-131,共11页
长江中下游是中国东部一个重要的Cu-Au-Fe-Mo矿成矿带。笔者等在5个夕卡岩-斑岩Cu-Au-Mo矿区采集了11件辉钼矿样品,在铜陵地区大团山层控夕卡岩Cu-Au-Mo矿体采集了5件辉钼矿样品进行Re-Os同位素年龄测定。在对16件样品进行ICP-MS方法测... 长江中下游是中国东部一个重要的Cu-Au-Fe-Mo矿成矿带。笔者等在5个夕卡岩-斑岩Cu-Au-Mo矿区采集了11件辉钼矿样品,在铜陵地区大团山层控夕卡岩Cu-Au-Mo矿体采集了5件辉钼矿样品进行Re-Os同位素年龄测定。在对16件样品进行ICP-MS方法测定的同时,还利用NTIMS方法对其中9件样品进行了精测,两种方法测定的结果基本吻合。16件辉钼矿的Re-Os同位素模式年龄为134.7±2.3~143.7±1.6Ma(2σ)。其中大团山铜矿区的5件样品的模式年龄更为接近,分布范围为 138.0± 3.2~140.8±2.0 Ma,平均 139.3±2.6Ma,其等时线年龄为 139.1±2.7Ma,初始Os为0.7±8.1(MSWD=0.29)。这些结果清楚地反映出夕卡岩-斑岩Cu-Au-Fe-Mo矿床与层控夕卡岩Cu-Au-Mo矿床为同一时代形成,属于同一成矿系统。作为中国东部大规模成矿作用的组成部分,长江中下游地区铜钼金矿床的形成与岩石圈构造体制大转换之地球动力学事件相耦合,为中生代第二期大规模成矿作用的产物。 展开更多
关键词 Re-Os年龄测定 铜矿 金矿 长江中下游地区
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河岸植被缓冲带与河岸带管理 被引量:236
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作者 邓红兵 王青春 +2 位作者 王庆礼 吴文春 邵国凡 《应用生态学报》 CAS CSCD 2001年第6期951-954,共4页
河岸带是水陆交错带的一种景观表现形式 ,即岸边陆地上同河水发生作用的植被区域 ,是介于河溪和高地植被之间的生态过渡带 .目前 ,河岸带的保护和管理日益为人们所关注 ,并成为自然资源经营及管理中不可缺少的部分 .本文对国外河岸带管... 河岸带是水陆交错带的一种景观表现形式 ,即岸边陆地上同河水发生作用的植被区域 ,是介于河溪和高地植被之间的生态过渡带 .目前 ,河岸带的保护和管理日益为人们所关注 ,并成为自然资源经营及管理中不可缺少的部分 .本文对国外河岸带管理有关的研究和实践进行了总结 ,对河岸带管理的目标、作用、一般途径、面临的问题以及将来发展趋势进行了讨论 ,并详细介绍了USDA FS的河岸植被缓冲带系统 .文章最后指出 ,有必要在国内尽快开展河岸带管理的研究和实践 . 展开更多
关键词 河岸植被缓冲带 河岸带 生态系统管理
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超轻多孔金属材料的多功能特性及应用 被引量:253
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作者 卢天健 何德坪 +3 位作者 陈常青 赵长颖 方岱宁 王晓林 《力学进展》 EI CSCD 北大核心 2006年第4期517-535,共19页
超轻多孔金属是近年来随着多样化需求的材料制备以及机械加工技术的迅速发展而出现的一类新颖多功能材料,是材料的选择及其性能研究的新课题,本文介绍有关多孔金属材料与结构基础研究的国内外研究现状和发展趋势,涉及材料制备、性能表... 超轻多孔金属是近年来随着多样化需求的材料制备以及机械加工技术的迅速发展而出现的一类新颖多功能材料,是材料的选择及其性能研究的新课题,本文介绍有关多孔金属材料与结构基础研究的国内外研究现状和发展趋势,涉及材料制备、性能表征等方面,着重于探讨多孔金属的多功能复合特性及其在国民经济和高技术中的应用。 展开更多
关键词 多孔金属材料 制备工艺 力学行为 物理波传播 传热特性
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中国非酒精性脂肪性肝病诊疗指南(2010年修订版) 被引量:275
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作者 范建高 《中国医学前沿杂志(电子版)》 2012年第7期4-10,共7页
非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)是一种与胰岛素抵抗(insulin resistance,IR)和遗传易感密切相关的代谢应激性肝脏损伤,其病理学改变与酒精性肝病(alcoholic liver disease,ALD)相似,但患者无过量饮酒史,... 非酒精性脂肪性肝病(nonalcoholic fatty liver disease,NAFLD)是一种与胰岛素抵抗(insulin resistance,IR)和遗传易感密切相关的代谢应激性肝脏损伤,其病理学改变与酒精性肝病(alcoholic liver disease,ALD)相似,但患者无过量饮酒史,疾病谱包括非酒精性单纯性脂肪肝(nonalcoholic simple fatty liver,NAFL)、非酒精性脂肪性肝炎(nonalcoholic steatohepatitis,NASH)及其相关肝硬化和肝细胞癌[1,2],NAFLD 是21世纪全球重要的公共健康问题之一,亦是我国愈来愈重视的慢性肝病问题[3]。 展开更多
关键词 脂肪肝 诊断 治疗 指南[文献类型] 代谢综合征
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