首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   3472篇
  免费   125篇
  2020年   47篇
  2019年   62篇
  2018年   89篇
  2017年   84篇
  2016年   99篇
  2015年   71篇
  2014年   62篇
  2013年   1110篇
  2012年   78篇
  2011年   89篇
  2010年   79篇
  2009年   79篇
  2008年   77篇
  2007年   58篇
  2006年   63篇
  2005年   42篇
  2004年   38篇
  2003年   32篇
  2002年   46篇
  2001年   51篇
  2000年   31篇
  1999年   45篇
  1998年   23篇
  1997年   31篇
  1996年   27篇
  1995年   23篇
  1994年   41篇
  1993年   32篇
  1992年   34篇
  1991年   21篇
  1990年   32篇
  1989年   28篇
  1988年   32篇
  1987年   33篇
  1986年   30篇
  1985年   33篇
  1984年   52篇
  1983年   55篇
  1982年   47篇
  1981年   38篇
  1980年   34篇
  1979年   41篇
  1978年   42篇
  1977年   30篇
  1976年   32篇
  1975年   34篇
  1973年   27篇
  1972年   31篇
  1971年   21篇
  1970年   32篇
排序方式: 共有3597条查询结果,搜索用时 15 毫秒
241.
In 1885, Dr. Guilio Melotti published an Italian translation of a lecture on "Convulsive Tics with Coprolalia and Echolalia" given by Jean-Martin Charcot. Although this lecture often has been cited as an authoritative statement of Charcot's view, until now it has not been translated into English. The lecture presents a number of statements that appear nowhere else in Charcot's published corpus, including some that seem to contradict Charcot's other pronouncements on maladie des tics. Although the Melotti-Charcot lecture may portray Charcot's position accurately in many passages, the article most likely is a compilation from a variety of sources.  相似文献   
242.
243.
244.
Historians have debated the degree to which past patients have provided meaningful consent prior to medical interventions. This article, a chart review of 170 patients treated for cancer between 1945 and 1970, adds to this literature by exploring the years when informed consent was being introduced in medical practice. As would be expected in a largely paternalistic era, physicians controlled most of the clinical encounters, even concealing cancer diagnoses. Yet thirty-one (18 percent) of the patients showed some involvement in decision making, either writing restrictions on their consent forms, asking probing questions, or otherwise challenging physicians' orders. Although the overall number of patients studied was small, minority and other ward patients were as likely as white, private patients to speak up. This study concludes that most patients passively assented to treatment, signing consent forms without making any inquiries. But a small group of patients challenged their physicians, leading them to learn more about proposed treatment options and perhaps make more informed decisions. Although motivated in part by the increasing attention to better consent practices, these patients spoke up for other reasons as well, possibly including their basic personalities, prior negative experiences in hospitals, or apprehensiveness regarding specific types of interventions. Further research should explore the factors--beyond the introduction of informed consent--that have historically promoted better dialogue between physicians and patients.  相似文献   
245.
Building upon Emile Meyerson's correspondence and other personal papers, all of them hosted by the Central Zionist Archives in Jerusalem, this article presents a mainly personal portrait of the philosopher (1859–1933). Thus this article describes his family circle in Lublin (Poland), his higher education (in Germany) and his professional course: settled in France, he worked first in chemistry, then get a job as foreign news editor and later took an important position at the Jewish Colonization Association. This article deals also with Meyerson's contacts with the French and international intellectuel milieu (scientists as well as writers).  相似文献   
246.
This article examines the introduction of blood transfusion into general practice from the end of the First World War to the Second World War. Developments during most of this period were not the result of new discoveries but rather the spread of ideas and the establishment of donor organizations to secure an adequate blood supply. The identification, testing, and organization of potential donors were done in a wide variety of settings that reflected differences in political and cultural experiences. At the end of the 1930s, with war approaching, the resolution of problems with storage of blood and the discovery of new techniques for separating and storing plasma dramatically changed transfusion practice. Thus, the innovations of the Second World War were very much based on the development of broad donor organizations plus the new technical discoveries that had occurred during the interwar period.  相似文献   
247.
248.
This study investigates temporal changes in dietary practices in the Caribbean archipelago during the Ceramic Age (400 BC–AD 1500), through analyses of dental wear and pathology. Some previous studies in the region have suggested that diet and subsistence practices changed over time due to increasing sociopolitical complexity, climate change, or adaptation to island environments rich in marine resources. Both horticultural/agricultural intensification and increased marine focus of the diet over time have been posited, based among other things on faunal and botanical remains, and early ethnohistorical accounts. Local and micro‐regional stable isotope studies of temporal dietary variation have found few indications for change over time, and large regional isotope studies are still lacking. Dentitions from sites throughout the region dating to the Early Ceramic Age (400 BC–AD 600/800) and the Late Ceramic Age (AD 600/800–1500) were analysed in order to assess temporal differences. Intra‐individual rates of wear were calculated using the difference in degree of wear between the adjacent molars and the two groups were compared with principal axis analysis. Caries, antemortem tooth loss, abscesses and dental calculus were recorded per individual and per tooth/socket, and population caries and antemortem tooth loss rates were assessed and compared by age group, tooth class and sex. Comparisons between the two occupation periods revealed significant differences in the rate of dental wear and pathology, indicating a shift in dietary practices over time, coinciding with known social changes. The increase in pathology rates suggests a rise in the consumption of cariogenic foods or preparation techniques that increase cariogenicity. The decrease in rate of wear over time indicates a reduction in abrasivity of the diet. Together these data suggest that there was a growing focus on refined, cariogenic foods, likely horticultural/agricultural produce. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
249.
It is believed on the basis of archaeozoological research that the domestic cat appeared in Central Europe during the Roman Period. In Poland, the domestic cat is a common species in medieval deposits. Only a few finds of cat remains of pre‐medieval age have been reported from Poland to date, including several specimens from deposits older than the Roman Period, dated to the pre‐Roman Period and even the Bronze Age. To clarify the earliest history of the domestic cat in Poland, the paper presents a review of the available published cat remains and adds some data about newly discovered remains. Combined methods of morphometry and ancient DNA were applied to enable distinction of wildcats and domestic cats. The domestic cat remains were radiocarbon dated. In six cases of domesticated cat reported in the literature, five were positively taxonomically verified, both by morphology and by genetic analysis, and one was recognised as a European wildcat. According to radiocarbon chronology, the oldest studied find is dated to the fourth–third century bc and represents a wildcat. Only two individuals of domestic cat – skeletons from Łojewo and Sławsko Wielkie, both from Kuyavia region (central‐northern Poland) – represent the Roman Period (first–third century ad ), and they are the oldest confirmed domestic cats in Poland. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
250.
Stable isotope analyses of human tooth enamel have allowed us to reconstruct the isotope composition of dietary carbon, changes in the oxygen isotope composition of drinking water and the possible migration of humans in ancient Terqa and Tell Masaikh (SE Syria). δ18Ocarbonate values of human tooth enamel from the interval comprising the Neo‐Assyrian to the modern Islamic periods (from 900 BC to AD 1949) generally mirror the isotope composition of Euphrates water, which is believed to have been a major drinking water source. Lower δ18Ocarbonate values of human Bronze Age apatite are linked to a different hydrologic system that was present in the Middle Euphrates valley at that time (2650–1700 BC). Higher δ18Ocarbonate values of some individuals in the Neo‐Assyrian (900–700 BC) and Islamic periods (AD 600–1200) may indicate human migration from the interior of the Near East. Low δ13Ccarbonate values (−11.3 to −12.4‰) of human tooth enamel from the interval comprising the Early Bronze to the Islamic periods (from 2650 BC to AD 1200) indicate C3 plants as a predominant source of dietary carbon. Changes in human dietary customs in SE Syria (with inferred usage of C4 plants) occurred in the modern Islamic period only (AD 1850–1949). Oxygen and carbon isotope data of sheep enamel show the usage of water bodies characterised by an enhanced evaporation rate during the Neo‐Assyrian time (900–700 BC) and grazing sheep herds on drier areas during the Islamic and the modern Islamic periods (after AD 600). Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号