全文获取类型
收费全文 | 27885篇 |
免费 | 2040篇 |
国内免费 | 63篇 |
专业分类
耳鼻咽喉 | 201篇 |
儿科学 | 704篇 |
妇产科学 | 393篇 |
基础医学 | 3907篇 |
口腔科学 | 467篇 |
临床医学 | 3398篇 |
内科学 | 4987篇 |
皮肤病学 | 261篇 |
神经病学 | 2449篇 |
特种医学 | 996篇 |
外科学 | 3824篇 |
综合类 | 397篇 |
一般理论 | 32篇 |
预防医学 | 3435篇 |
眼科学 | 551篇 |
药学 | 2050篇 |
中国医学 | 53篇 |
肿瘤学 | 1883篇 |
出版年
2023年 | 190篇 |
2022年 | 277篇 |
2021年 | 612篇 |
2020年 | 392篇 |
2019年 | 548篇 |
2018年 | 666篇 |
2017年 | 470篇 |
2016年 | 562篇 |
2015年 | 706篇 |
2014年 | 895篇 |
2013年 | 1214篇 |
2012年 | 1978篇 |
2011年 | 2042篇 |
2010年 | 1141篇 |
2009年 | 1070篇 |
2008年 | 1723篇 |
2007年 | 1947篇 |
2006年 | 1801篇 |
2005年 | 1732篇 |
2004年 | 1692篇 |
2003年 | 1586篇 |
2002年 | 1413篇 |
2001年 | 394篇 |
2000年 | 359篇 |
1999年 | 333篇 |
1998年 | 301篇 |
1997年 | 209篇 |
1996年 | 198篇 |
1995年 | 158篇 |
1994年 | 174篇 |
1993年 | 156篇 |
1992年 | 199篇 |
1991年 | 196篇 |
1990年 | 175篇 |
1989年 | 193篇 |
1988年 | 171篇 |
1987年 | 225篇 |
1986年 | 167篇 |
1985年 | 165篇 |
1984年 | 145篇 |
1983年 | 131篇 |
1982年 | 75篇 |
1981年 | 82篇 |
1980年 | 77篇 |
1979年 | 78篇 |
1978年 | 81篇 |
1976年 | 76篇 |
1974年 | 73篇 |
1973年 | 83篇 |
1972年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Paraimmunoblastic variant of small lymphocytic lymphoma/leukemia 总被引:1,自引:0,他引:1
We report 16 cases of a distinctive, biologically aggressive variant of small lymphocytic lymphoma/leukemia (SLL/L) that is characterized by the diffuse proliferation of cells normally comprising the pseudoproliferation centers (so-called paraimmunoblasts). Demographically, the patients differed in no significant regard from patients with SLL/L of usual type. Rapidly progressive, generalized lymphadenopathy was the dominant clinical finding in 15 of the 16 patients; one patient presented with symptoms related to lymphomatous involvement of the stomach and regional lymph nodes. Splenomegaly was observed in five patients. Seven patients, two of whom had a history of indolent-phase chronic lymphocytic leukemia, had an absolute lymphocytosis at diagnosis. In most patients, bone marrow involvement was noted at diagnosis. It consisted predominantly of small lymphocytic infiltrates indistinguishable from those observed in SLL/L of usual type; significant paraimmunoblastic infiltration was infrequent and generally occurred late in the disease course. Immunohistochemical and cytogenetic study further substantiated the hypothesized relationship of these cases to SLL/L. Findings included (a) coexpression of sIg and Leu-1 antigen in the majority of cases and (b) the presence of a t(11;14) (q13;q32) chromosome translocation in two of three cases with analyzable metaphases. Although treatment protocols were not uniform, follow-up data indicated an accelerated clinical course. Eleven patients have died of their disease between 3 and 39 months after diagnosis; the median survival was 28 months. 相似文献
42.
Background
Persisting neck pain is common in society. It has been reported that the prevalence of neck pain in office workers is much higher than in the general population. The costs to the worker, employer and society associated with work-related neck pain are known to be considerable and are escalating. The factors that place office workers at greater risk of developing neck pain are not understood. The aim of this study is to investigate the incidence and risk factors of work-related neck pain in Australian office workers. 相似文献43.
44.
45.
The evolution of the dorsal thalamus in various vertebrate lineages of jawed vertebrates has been an enigma, partly due to two prevalent misconceptions: the belief that the multitude of nuclei in the dorsal thalamus of mammals could be meaningfully compared neither with the relatively few nuclei in the dorsal thalamus of anamniotes nor with the intermediate number of dorsal thalamic nuclei of other amniotes and a definition of the dorsal thalamus that too narrowly focused on the features of the dorsal thalamus of mammals. The cladistic analysis carried out here allows us to recognize which features are plesiomorphic and which apomorphic for the dorsal thalamus of jawed vertebrates and to then reconstruct the major changes that have occurred in the dorsal thalamus over evolution. Embryological data examined in the context of Von Baerian theory (embryos of later-descendant species resemble the embryos of earlier-descendant species to the point of their divergence) supports a new ‘Dual Elaboration Hypothesis’ of dorsal thalamic evolution generated from this cladistic analysis. From the morphotype for an early stage in the embryological development of the dorsal thalamus of jawed vertebrates, the divergent, sequential stages of the development of the dorsal thalamus are derived for each major radiation and compared. The new hypothesis holds that the dorsal thalamus comprises two basic divisions—the collothalamus and the lemnothalamus—that receive their predominant input from the midbrain roof and (plesiomorphically) from lemniscal pathways, including the optic tract, respectively. Where present, the collothalamic, midbrain-sensory relay nuclei are homologous to each other in all vertebrate radiations as discrete nuclei. Within the lemnothalamus, the dorsal lateral geniculate nucleus of mammals and the dorsal lateral optic nucleus of non-synapsid amniotes (diapsid reptiles, birds and turtles) are homologous as discrete nuclei; most or all of the ventral nuclear group of mammals is homologous as a field to the lemniscal somatosensory relay and motor feedback nuclei of non-synapsid amniotes; the anterior, intralaminar and medial nuclear groups of mammals are collectively homologous as a field to both the dorsomedial and dorsolateral (including perirotundal) nuclei of non-synapsid amniotes; the anterior, intralaminar, medial and ventral nuclear groups and the dorsal lateral geniculate nucleus of mammals are collectively homologous as a field to the nucleus anterior of anamniotes, as are their homologues in non-synapsid amniotes. In the captorhinomorph ancestors of extant land vertebrates, both divisions of the dorsal thalamus were elaborated to some extent due to an increase in proliferation and lateral migration of neurons during development. Mammals are unique in the degree to which their synapsid ancestors further elaborated the lemnothalamus, so that the identity of and previous experience with objects in their environment has become their most salient priority. 相似文献
46.
A device called the Dex Frame has recently been marketed as an aid for children with specific learning difficulties. Using a test of reading speed and a test of reading accuracy we have attempted to evaluate the device. Two groups of children with learning difficulties were used, one having sole use of the device and being allowed to carry it with them and a second group who only used the device when attending for remedial tuition and assessment. The results show that no significant improvement occurred in reading performance of the groups with learning difficulties using the Dex Frame as compared with a control group. The teachers of the groups did, however, feel that on an individual basis some children (< 10%) expressed that they felt more comfortable using the device. 相似文献
47.
48.
49.
50.
Peter M Miller Ruth Stockdell Lynne Nemeth Chris Feifer Ruth G Jenkins Paul J Nietert Andrea Wessell Heather Liszka Steven Ornstein 《Substance Abuse》2006,27(1-2):61-70
Many medical conditions are caused or exacerbated by heavy drinking, necessitating alcohol screening and discussion in primary care practices. This is particularly true of hypertension, the most common primary diagnosis in the United States, which has been linked to the regular consumption of 3 or more standard alcoholic beverages a day. The Accelerating Alcohol Screening-Translating Research into Practice (AA-TRIP) project was designed to improve detection and management of alcohol problems in primary care patients with hypertension. Medical providers are being trained using the Practice Partner Research Network's- Translating Research into Practice (PPRNet-TRIP) quality improvement model. This includes a multi-method intervention (electronic medical records, on-site academic detailing, practice feedback reports and annual network meetings) to help practices increase adherence to clinical guidelines. Qualitative analyses of initial steps taken by nine primary care practices toward the routine implementation of alcohol screening guidelines are presented. Organizational factors and provider and patient characteristics all influenced the method and consistency of alcohol screening and intervention. Perceived time constraints, patient sensitivity to questions about alcohol, and possible stigma associated with a diagnosis of alcoholism were also relevant barriers requiring problem solving. 相似文献