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   1466篇
  免费   55篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   45篇
妇产科学   22篇
基础医学   202篇
口腔科学   34篇
临床医学   172篇
内科学   206篇
皮肤病学   20篇
神经病学   170篇
特种医学   50篇
外科学   117篇
综合类   29篇
预防医学   193篇
眼科学   27篇
药学   134篇
中国医学   24篇
肿瘤学   71篇
  2023年   9篇
  2022年   25篇
  2021年   28篇
  2020年   22篇
  2019年   103篇
  2018年   72篇
  2017年   53篇
  2016年   42篇
  2015年   49篇
  2014年   54篇
  2013年   103篇
  2012年   38篇
  2011年   55篇
  2010年   51篇
  2009年   50篇
  2008年   56篇
  2007年   51篇
  2006年   32篇
  2005年   33篇
  2004年   35篇
  2003年   20篇
  2002年   20篇
  2001年   24篇
  2000年   16篇
  1999年   11篇
  1998年   14篇
  1997年   9篇
  1996年   18篇
  1995年   16篇
  1994年   17篇
  1993年   10篇
  1991年   15篇
  1990年   10篇
  1989年   11篇
  1988年   18篇
  1987年   9篇
  1986年   10篇
  1985年   42篇
  1984年   51篇
  1983年   25篇
  1982年   21篇
  1981年   27篇
  1980年   23篇
  1979年   24篇
  1978年   14篇
  1977年   20篇
  1976年   13篇
  1975年   20篇
  1974年   10篇
  1973年   14篇
排序方式: 共有1525条查询结果,搜索用时 203 毫秒
1.
The midwifery art has emphasised the uniqueness of human beings throughout its Nordic history. The educated Nordic midwife has in the last decade celebrated several hundred years of memories. This article studies how the key ideas of the midwifery art and patterns of ideas become evident in the zeitgeist from the beginning of the 19th century to the millennium in the Nordic countries. The legacy and pattern of ideas of the art of midwifery are interpreted in relation to the texts of the selected historical sources and based on Ricoeur's phenomenological-hermeneutic approach to the text and further to the dedication of understanding and interpretation. The historical sources refer to unprinted primary sources from historical archives and printed secondary and tertiary sources. The patterns of ideas include a tripartite whole: the true cultivation of the head, the philosophy and aesthetics of the hand, the strength of the heart and the drive of calling. These ideas open for unique visions and attest to the evident in modern midwives. Today's midwives have academic training with examinations, and the education is based on scientific evidence. The midwife profession is authorised by the state and supervised by the authorities.  相似文献   
2.
The county of Vestfold in the South-eastern part of Norway has undergone two incidence and prevalence surveys on multiple sclerosis. The prevalence of definite/probable MS on January 1.1963 was 61.6/100000. Based on the same diagnostic criteria, the present study reports a slight increase in prevalence to 86.4/100000 on January 1st 1983. The average annual incidence was calculated for 5 years periods from 1953 to 1983. The time periods 1953–1962 and 1973–1977 showed age-adjusted incidence rates between 4.50 and 5.49/100000 while the 10–year period 1963–1972 showed significantly lower rates. The fluctuating pattern of MS incidence and prevalence over time supports the view that MS is not a stable disease, and that exogenous factors are influencing the disease pattern.  相似文献   
3.
International comparisons show that populations having a high consumption of fish experience low incidence of breast cancer. We compared death rates from breast cancer among socioeconomic groups in a prospective study of 533,276 Norwegian women aged 35–54 years who were followed from 1970 through 1985. Compared with the reference group (wives of unskilled workers) the fishermen's wives had a decreased risk of breast cancer with a relative risk (RR) of 0.67 (95% confidence interval [CI]=0.47–0.94) adjusted for age and the number of children. Among fishermen's wives who were parous, adjustment for age at first birth gave an RR of 0.62 (CI=0.43–0.91). This study supports the hypothesis that certain aspects of diet, i. e., fish consumption, may be associated with lower breast-cancer mortality.Drs Lund and Bønaa are with the Institute of Community Medicine, University of Tromsø, Tromsø, Norway. Address correspondence to Dr Lund, Institute of Community Medicine, University of Tromsø, N-9037 Tromsø, Norway.  相似文献   
4.
BACKGROUND.: Mercuric chloride (HgCl2 induces a lymphoproliferative disorderand autoimmune glomerulonephritis in Brown Norway (BN) rats.This syndrome is the consequence of T cell-dependent polyclonalB cell activation and autoantibody production. We have previouslyshown that HgCl2-induced autoimmune perturbations can be preventedin BN rats by the administration of cyclosporin A (CsA). Themost potent vitamin D3 metabolite 1,25(OH)2 D3 (Vit D3) sharescertain immunomodulatory properties with CsA. We therefore choseto compare the effects of Vit D3 to those of CsA in BN ratstreated with HgCl2 in order to establish whether Vit D3 eitheralone or in combination with CsA can attenuate an autoimmunesyndrome in vivo. METHODS.: BN rats were treated with HgCl2 according to a standard protocol.Subgroups of rats were also given CsA alone, Vit D3 or syntheticanalogues of Vit D3 alone, or combinations of both agents. Differentdoses and routes of administration were compared. The followingmarkers of disease activity were evaluated: mortality, peakproteinuria, serum IgE concentrations, and renal immunoglobulindeposition. RESULTS.: Disease activity was markedly attenuated in all rats treatedwith CsA alone. Vit D3 and certain of its synthetic analoguesadministered alone also tempered the autoimmune process, butto a lesser extent than did CsA. The effect of CsA alone wasso potent, that no additive or synergistic effects could bedemonstrated when CsA was administered in combination with VitD3. CONCLUSIONS.: Despite similar described immunomodulatory effects in vitro,CsA is clearly more effective than Vit D3 in preventing HgCl2autoimmune disease in BN rats. This suggests that there is adifference in the cellular targets of these two agents in vivo,and/or a difference in the potency with which HgCl2-triggeredimmune activation is suppressed.  相似文献   
5.
Experimental autoimmune glomerulonephritis (EAG) was induced in brown Norway (BN) rats by a single i.m. injection of collagenase-solubilized homologous glomerular basement membrane (GBM) in Freund's complete adjuvant. This model of anti-GBM disease is characterized by the development, over several weeks, of circulating and deposited anti-GBM antibodies, accompanied by albuminuria. We examined the effects of treatment with oral cyclosporin A (CsA) at different doses, starting at the time of immunization and during the course of the disease. Pretreatment with CsA 5 mg kg daily produced a moderate reduction in circulating anti-GBM antibody levels, reduced deposition of antibody on the GBM and decreased albuminuria. Doses of 10 and 20 mg/kg CsA produced a marked reduction in circulating antibody, absence of detectable deposited antibody and virtual absence of albuminuria. Renal function remained normal in CsA-treated and control animals. When CsA treatment was introduced at 2 or 4 weeks after immunization, there were significant effects on the subsequent autoimmune response and albuminuria at 10 and 20 mg/kg daily. These studies demonstrate that CsA in conventional doses has a therapeutic effect in this model of anti-GBM disease, and suggest a role for T lymphocytes in the pathogenesis of EAG.  相似文献   
6.
7.
The high affinity uptakes of asparate (Asp) and glutamate (Glu) were heavily and selectively reduced in the lateral septum (?67%) and mammillary body (?52%) by surgical interruption of their connections with the hippocampal formation in rats. There was no reduction in the medial septum. GABA uptake, glutamate decarboxylase, choline acetyltransferase and carnitine acetyltransferase were not reduced. Choline acetyltransferase was increased (+51%) in the lateral septum. The normal activities of these parameters showed characteristic distribution patterns between medial and lateral septum, mammillary body and hippocampus. The ratio of Glu and Asp uptakes was not changed by lesions and vaired only little between the regions sampled.  相似文献   
8.
BACKGROUND: No adequate enteral sensitization models are available to study food allergy and the allergenicity of food proteins. To further validate an enteral brown Norway (BN) rat sensitization model under development, we studied specific protein recognition to determine whether a comparable pattern of proteins is recognized by the rat immune system and the human immune system. METHODS: The animals were exposed to either ovalbumin as a positive reference control, hen's egg-white-protein extract, or a cow's milk preparation by daily gavage dosing (0.5, 1, 2.5, 5, 10, or 15 mg protein per rat/day) for 9 weeks. No adjuvants were used during the sensitization studies. The specificities of antibodies against hen's egg-white proteins or cow's-milk proteins in sera from orally sensitized rats and food-allergic patients were studied and compared by immunoblotting. RESULTS: The IgG and IgE antibodies to hen's egg-white proteins and cow's-milk proteins present in sera from orally sensitized rats and food-allergic patients showed a comparable pattern of protein recognition. CONCLUSIONS: Upon daily intragastric exposure to food allergens, the specificities of the induced antibody responses in the BN rat resemble those found in food-allergic patients. These studies add further support to the hypothesis that the BN rat may provide a suitable animal model for food allergy research and research on the allergenicity of food proteins.  相似文献   
9.
Summary For years, brown tumors have been considered to be a characteristic of primary hyperparathyroidism. However, since 1963 several reports indicate the incidence of brown tumors in patients with renal secondary hyperparathyroidism to be 1.5%–1.7%. The appearance of multiple brown tumor lesions is rather uncommon in secondary hyperparathyroidism which is also true for malabsorption as its cause. We report on a 56-year-old man presenting with pain in the bones and multiple osteolyses. A bone biopsy specimen and the laboratory examinations were indicative of secondary hyperparathyroidism caused by malabsorption most likely due to Billroth's II/I gastric resection. Thus, the patient's osteolyses represent brown tumors which have been induced by nutritional secondary hyperparathyroidism.  相似文献   
10.
Seven groups of laboratory reared Connecticut P. leucopus were exposed to a 9L:15D photoperiod for either 6, 9, 12, 20, 25, 32, or 36 weeks. An eighth group was maintained on 16L:8D. During the final 6 weeks all mice were cold exposed (13°C). Substantial reproductive regression occurred in females following 6 weeks exposure to 9L:15D relative to 16L:8D animals. In males, a slight decrease in testicular weight occurred following 6 weeks on 9L:15D; this effect was pronounced by 9 weeks, along with a decrease in seminal vesicle weight. Reproductive recrudescence occurred in females by week 32 and in males by week 36. Between 10 and 12 weeks on 9L:15D mice exhibited increases in nesting, incidence of daily torpor, and presence of the winter molt. These increases persisted through 36 weeks on 9L:15D. An increase in the interscapular brown fat pad occurred between 12 and 25 weeks. Reproductive and thermoregulatory characters respond differently to prolonged exposure to a short day photoperiod in this species.  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