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   335篇
  免费   44篇
  国内免费   3篇
儿科学   12篇
妇产科学   2篇
基础医学   28篇
口腔科学   7篇
临床医学   35篇
内科学   61篇
皮肤病学   10篇
神经病学   89篇
特种医学   32篇
外科学   42篇
综合类   11篇
预防医学   24篇
眼科学   1篇
药学   9篇
肿瘤学   19篇
  2023年   4篇
  2022年   2篇
  2021年   4篇
  2020年   4篇
  2019年   9篇
  2018年   8篇
  2016年   3篇
  2015年   3篇
  2014年   8篇
  2013年   10篇
  2012年   7篇
  2011年   9篇
  2010年   5篇
  2009年   14篇
  2008年   13篇
  2007年   17篇
  2006年   15篇
  2005年   8篇
  2004年   10篇
  2003年   10篇
  2002年   23篇
  2001年   10篇
  2000年   13篇
  1999年   9篇
  1998年   12篇
  1997年   14篇
  1996年   10篇
  1995年   14篇
  1994年   8篇
  1993年   6篇
  1992年   7篇
  1991年   5篇
  1990年   6篇
  1989年   6篇
  1988年   11篇
  1987年   4篇
  1986年   2篇
  1985年   6篇
  1984年   5篇
  1983年   6篇
  1982年   7篇
  1981年   6篇
  1980年   8篇
  1979年   4篇
  1974年   3篇
  1973年   5篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1969年   2篇
排序方式: 共有382条查询结果,搜索用时 9 毫秒
31.
This study examined the criterion validity and sensitivity and specificity of a single item to rapidly screen patients in ambulatory oncology clinics for cancer-related fatigue. In an effort to expand the utility of the Zung Self-Rating Depression Scale (ZSDS) as a screen for other symptoms, the utility of the single fatigue item was examined. The fatigue item reads "I get tired for no reason" and is rated on a four-point scale ranging from "none or a little of the time" to "most or all of the time." Fifty-two subjects were administered the Zung, the Functional Assessment of Cancer Therapy-Anemia (FACT-An) scale, and the Fatigue Symptom Inventory (FSI). The Zung item was highly correlated with the ZSDS (r= 0.63, p < 0.0001) and the FACT-An (r = -0.70, p < 0.0001), as well as to the individual items of the FSI, ranging from 0.41 (p < 0.003) to 0.71 (p < 0.0001). All 10 subjects considered to be depressed based on the ZSDS were also considered to fatigued on the FACT-An. Setting the ZSDS item cutoff point at level 3--"A good part of the time"--yielded a sensitivity of 78.95% and a specificity of 87.88%. It is concluded that a single item can be a fast and accurate way of screening cancer patients for fatigue to trigger additional follow-up, thus expanding the utility of a depression screening tool for problems other than the purely psychiatric.  相似文献   
32.
BACKGROUND: Vasculitis of the peripheral nervous system (PNS) is rare. There are no controlled treatment trials, and clinical practice is guided by experience from case series and indirectly by analogy with systemic vasculitis. METHODS: We identified patients (n=212) with possible vasculitic peripheral neuropathy (VPN) from the neuropathology and neurophysiology records of two centres over 28 years. Case-notes were available for 181, from which, 106 cases of clinicopathological VPN were identified. Adequate treatment data were available in 100; follow-up data, in 93. RESULTS: Of 106 cases, 95 had systemic vasculitis and 11 had vasculitis confined to the PNS. Pharmacological treatment (94/100 cases) was corticosteroid-based, and included cyclophosphamide in 54; 17 received additional agents. Initial stabilization was achieved in all but six. One-year survival was 90.3%. Of the nine who died in the first years (mean age 73 years), seven had received cyclophosphamide, and all but two had severe, multisystem vasculitis. The neurological relapse rate was 10%. Only one relapse occurred after cyclophosphamide treatment. Outcome was reported as good in 72% (78% in those who relapsed). DISCUSSION: Death and relapse were infrequent in treated patients. Relapse occurred almost exclusively in patients treated with prednisolone alone. Aggressive early treatment with cyclophosphamide may prevent relapse. The current management approach to VPN appears largely effective, especially if cyclophosphamide is used.  相似文献   
33.
34.
35.
36.
37.
Fifty-one patients with previously untreated or minimally treated chronic myelogenous leukemia in chronic phase received human alpha interferon 3 to 9 X 10(6) units intramuscularly (IM) daily until complete hematologic remission, then at doses ranging from 3 X 10(6) units every other day to 9 X 10(6) units daily. Forty-one (80%) patients achieved a hematologic response, 36 (71%) of them attaining a complete hematologic remission with normal peripheral WBC and differential counts. Responding patients showed continuous but slow normalization of several other blood and marrow parameters including platelet counts, serum lactic dehydrogenase and B12 levels, and marrow cellularity and maturation index. Suppression of the Philadelphia chromosome on serial cytogenetic studies of marrow metaphases was documented in 20 of the 36 patients who achieved complete hematologic remission (56%; 39% of total group), eight of whom (22%) had a decrease of the Philadelphia chromosome-positive metaphases to less than 35%. These changes were persistent for 6 months or longer in 18 patients, seven of whom had continuous suppression of the Philadelphia chromosome to less than 90% for a median of 30+ months (range 21+ to 39+ months). After a median follow-up period of 37 months, 25 patients remain in continued disease control with interferon therapy. The projected 3-year survival rate is 76%, with a yearly death rate of 6%, 9%, and 9% in the first 3 years. Response, Philadelphia chromosome suppression, and survival were significantly better among patients in the low-risk category compared to intermediate- and high-risk categories, as defined by a multivariate analysis-derived prognostic model. The projected 3- year survival rate was 94% for patients who achieved a complete hematologic remission on interferon therapy and 45% for those who did not. Thirteen patients have developed blastic crisis, six with lymphoid and three with undifferentiated morphology. We conclude that human leukocyte alpha interferon effectively controls chronic myeloid leukemia and allows reappearance of diploid hemopoietic cells in some patients.  相似文献   
38.
Aglycaemic / anoxic slices of rat olfactory cortex lose all electrical activity. On reoxygenation, 10 μM adenosine enhanced recovery from 23 ± 7% to 53 ± 12%; an increased tissue endurance of 5–7 min. 100 μM adenosine slightly depressed recovery to 11.5 ± 2.1%. Dipyridamole increasedwhereas adenosine deaminase reduced recovery. These observations question the therapeutic effectiveness of high adenosine concentrations.  相似文献   
39.
Stevenson  KB; Clark  RA; Nauseef  WM 《Blood》1989,74(6):2136-2143
Erythrocytes possess a well-characterized submembranous filamentous network which interacts with transmembrane glycoproteins and is composed primarily of spectrin, ankyrin, band 4.1, and short actin filaments. An analogous structure was recently described in platelets. Human polymorphonuclear leukocytes (PMNs) were examined for the presence and plasma membrane association of similar proteins. Isolated PMNs, free of contamination with erythrocytes or platelets, were disrupted by nitrogen cavitation and separated into subcellular organelles on a discontinuous Percoll gradient. Detergent lysates of plasma membrane vesicles, but not azurophilic or specific granules, contained insoluble actin filaments and associated proteins. Immunoblots of detergent-insoluble plasma membrane fractions contained proteins recognized by antibodies to brain fodrin and erythrocyte band 4.1, whereas blots probed with antibodies to erythrocyte spectrin and ankyrin were negative. Fodrin and band 4.1 were not detected in granule fractions, but some fodrin was present in the cytosol. The association of proteins related to fodrin and band 4.1 with the plasma membrane suggests that PMNs contain a submembranous skeleton structurally analogous to that of erythrocytes and platelets. The specific function of these proteins and their structural organization in human PMNs await further study.  相似文献   
40.
Lyme borreliosis, caused by the tick-borne bacterium Borrelia burgdorferi, has become the most common vector-borne disease in North America over the last three decades. To understand the dynamics of the epizootic spread and to predict the evolutionary trajectories of B. burgdorferi, accurate information on the population structure and the evolutionary relationships of the pathogen is crucial. We, therefore, developed a multilocus sequence typing (MLST) scheme for B. burgdorferi based on eight chromosomal housekeeping genes. We validated the MLST scheme on B. burgdorferi specimens from North America and Europe, comprising both cultured isolates and infected ticks. These data were compared with sequences for the commonly used genetic markers rrs-rrlA intergenic spacer (IGS) and the gene encoding the outer surface protein C (ospC). The study demonstrates that the concatenated sequences of the housekeeping genes of B. burgdorferi provide highly resolved phylogenetic signals and that the housekeeping genes evolve differently compared with the IGS locus and ospC. Using sequence data, the study reveals that North American and European populations of B. burgdorferi correspond to genetically distinct populations. Importantly, the MLST data suggest that B. burgdorferi originated in Europe rather than in North America as proposed previously.  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