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   1278篇
  免费   116篇
  国内免费   122篇
耳鼻咽喉   10篇
儿科学   37篇
妇产科学   16篇
基础医学   113篇
口腔科学   23篇
临床医学   217篇
内科学   355篇
皮肤病学   39篇
神经病学   30篇
特种医学   110篇
外科学   124篇
综合类   63篇
预防医学   60篇
眼科学   40篇
药学   127篇
中国医学   12篇
肿瘤学   140篇
  2022年   14篇
  2021年   12篇
  2020年   13篇
  2019年   13篇
  2018年   29篇
  2017年   20篇
  2016年   18篇
  2015年   42篇
  2014年   49篇
  2013年   68篇
  2012年   54篇
  2011年   57篇
  2010年   50篇
  2009年   52篇
  2008年   39篇
  2007年   111篇
  2006年   58篇
  2005年   49篇
  2004年   31篇
  2003年   39篇
  2002年   35篇
  2001年   23篇
  2000年   17篇
  1999年   22篇
  1998年   48篇
  1997年   36篇
  1996年   34篇
  1995年   24篇
  1994年   28篇
  1993年   25篇
  1992年   31篇
  1991年   41篇
  1990年   37篇
  1989年   36篇
  1988年   39篇
  1987年   28篇
  1986年   20篇
  1985年   20篇
  1984年   11篇
  1983年   10篇
  1982年   14篇
  1981年   11篇
  1980年   12篇
  1979年   11篇
  1978年   6篇
  1977年   9篇
  1976年   8篇
  1975年   9篇
  1974年   6篇
  1958年   14篇
排序方式: 共有1516条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: On December 26, 2004, the biggest earthquake for 40 years, measuring 9.0 on the Richter scale, triggered a tsunami that pounded the coastal areas of South Asia and East Africa. The effects of the tsunami on skin conditions have not been evaluated. OBJECTIVE: To determine the influence of the tsunami on skin conditions by evaluating the skin problems of patients presenting at hospitals after the tsunami. METHODS: Between 5 and 25 January 2005, two dermatologists evaluated patients who complained of skin problems at an outpatient clinic and emergency room of a general hospital in Banda Aceh, Aceh Province, Indonesia. RESULTS: The total number of patients that presented during the study period was 235 (131 males and 104 females), and they had a total of 265 skin problems. In terms of age distribution, most subjects were in their fourth decade (23.0%), followed by the third (22.6%) and fifth decade (16.6%). The most prevalent skin problems were infections-infestations (32.5%), followed by eczemas (29.8%) and traumatic skin disorders (29.4%). In males, traumatic skin disorders were most common. The great majority of infection-infestation cases involved superficial fungal infections. Contact dermatitis accounted for three-quarters of eczema cases, and mainly involved the arms (40.0%) and legs (27.1%). The majority of traumatic skin disorders were lacerations, punctures and penetrations, and the feet (44.7%) and hands (18.8%) were most frequently affected. CONCLUSIONS: Unhygienic conditions, exposure to a hazardous environment and contact with various objects during and after the tsunami probably increased the prevalence of infections-infestations, traumatic skin disorders and contact dermatitis. To prevent these problems and associated secondary bacterial infections, health-related education and early medical management are required.  相似文献   
2.
Summary— KR31080 (2-butyl-5-methyl-6-(1-oxopyridin-2-yl)-3-[[2'-(1H-tetrazol-5-yl) biphenyl-4-yl]methyl]-3H-imidazo[4,5-b] pyridine) is a potent inhibitor of angiotensin type 1 (AT1) receptors in rabbit aorta and human recombinant AT1 receptors. In the isolated rabbit thoracic aorta, KR31080 caused a nonparallel shift to the right of the concentration-response curves to angiotensin II (All) with decreased maximal response (pD'2 = 10.1 ± 0.1), but had no effect on the contractile response induced by norepinephrine. KR31080 inhibited specific [125I]AII binding to rabbit aortic membranes (AT, receptors) and [125I][Sar1, Ile8]AII binding to human recombinant AT1 receptors in a concentration-dependent manner with IC50 values of 0.84 ± 0.08 nM and 1.92 ± 0.15 nM, respectively, but did not inhibit specific [125I)AII binding to bovine cerebellum membranes (ÀT2 receptors). In the Scatchard analysis, KR31080 interacted with rabbit aortic AT1 receptors in a competitive manner, similar to losartan. These results demonstrate that KR31080 is a potent and AT1 selective angiotensin receptor antagonist which exerts a competitive antagonism in the [125I]AII binding assay and insurmountable AT1 receptor antagonism in the functional study.  相似文献   
3.
Soft tissue sarcomas of the head and neck in adults   总被引:1,自引:0,他引:1  
We reviewed the clinical records and pathologic material of 176 adults with primary soft tissue sarcomas treated at Memorial Sloan-Kettering Cancer Center between 1950 and 1985. Seventy-two patients (41%) had low-grade sarcomas and 104 (59%) had high-grade sarcomas. All but 18 patients underwent some form of excision as initial therapy. Adjuvant radiotherapy and chemotherapy combined with surgical excision showed no significant effect. A significantly increased risk of treatment failure was associated with large tumor size, positive surgical margins, bone involvement, local recurrence, metastatic spread, and high histologic grade. Except for recurrence, the p value by univariate analysis in the log-rank test for comparison of survival according to these clinical and pathologic characteristics was p less than 0.0001. Although the overall survival was 75% at 2 years, 55% at 5 years, and 46% at 10 years, only 20% of the patients with high-grade sarcomas were alive 10 years after treatment. Most patients with rhabdomyosarcoma, high-grade peripheral nerve tumor, and high-grade fibrous histiocytoma and all patients with high-grade angiosarcoma died of disease less than 5 years after diagnosis. New therapeutic strategies are needed to improve the survival of adult patients with high-grade soft tissue sarcomas of the head and neck.  相似文献   
4.
5.
We report on the development of features of the postpericardiotomy syndrome following coronary perforation during balloon angioplasty, in a patient that was managed conservatively. The case illustrates that while cardiac tamponade does not invariably follow coronary perforation, late consequences derived from this complication may occur. It also widens the spectrum of conditions where the postpericardiotomy syndrome has been observed.  相似文献   
6.
Summary A phase II study of high-dose ifosfamide in hepatocellular carcinoma was conducted among 17 Chinese patients. The dose of ifosfamide used was 2.5 g/m2 daily given as a continuous infusion for 5 days. In all, 15 patients were evaluable for tumour response. There was no complete or partial responder. The treatment was well tolerated. The most frequent toxicity was alopecia, which occurred in 11 patients, and 5 patients developed mild haematological toxicity. There was no evidence of liver or bladder toxicity. Overall, 14 patients were evaluable for survival. The median survival was 92 days (range, 30–568 days). We conclude that high-dose ifosfamide is well tolerated but ineffective in hepatocellular carcinoma in Chinese patients.  相似文献   
7.
BACKGROUND: Autoantibody production by the fetus is thought to be extremely unlikely. Only one possible case of in utero autoantibody production against red cells by the fetus has previously been described. STUDY DESIGN AND METHODS: A case of apparent red cell IgG autoantibody production in utero is reported. RESULTS: This was established by a positive direct antiglobulin test in a newborn infant without evidence of maternal alloantibodies or autoantibodies. There was no evidence of clinically significant hemolysis at the infant's birth. After 6 weeks, his direct antiglobulin test remained strongly positive. The infant thrived without evidence of hemolysis, and after 6 months the direct antiglobulin test was negative. CONCLUSION: The production of autoantibodies to red cells in utero is possible, though rare. This did not result in apparent hemolysis in this patient.  相似文献   
8.
The hormonally responsive prolactin-inducible protein (PIP), gene is expressed in benign and malignant breast tumor tissues and in such normal exocrine organs as sweat, salivary, and lacrimal glands. In this communication we report the regional chromosome localization of the PIPgene locus to chromosome 7 by Southern hybridization to DNA from human-hamster somatic cell hybrids, and to 7q32–36 by in situ hybridization.  相似文献   
9.
Summary Human cytomegalovirus (HCMV) infection is an important cause of neonatal death. Using primers derived from sequences within the morphological transforming region II (mtrII), HCMV DNA was amplified by polymerase chain reaction (PCR) from fixed tissues of infants who had died of congenital HCMV infection. In one neonate, HCMV DNA with reduction in the expected size was detected in the liver, spleen, kidney, adrenal, und thyroid tissues by gel electrophoresis. Nucleotide sequencing of the PCR product revealed a 65bp frame-shift deletion within the 79 amino acid open reading frame (ORF) of themtrII. Based upon this observation, it is likely that viral genomic rearrangement involving themtrII may occur in some cases of congenital HCMV infection.  相似文献   
10.
The present study investigated the role of lateral septal serotonin (5HT) in memory consolidation and the subtype of 5HT receptors involved in this process. Rats with cannulae implanted bilaterally into the lateral septum were trained in an inhibitory avoidance task. Immediately after training, the septal serotonergic function was manipulated by pharmacological agents selectively blocking 5HT reuptake (fluoxetine and zimelidine), antagonizing 5HT2 receptors (ketanserin and ritanserin), or activating 5HT1A receptors, respectively. Results indicated that direct fluoxetine infusions into the lateral septum at a dose of 6 micrograms/0.5 microliter and zimelidine at a dose of 5 micrograms/0.5 microliter both markedly enhanced memory. Intralateral septal injections of ketanserin (0.3 microgram/0.5 microliter and 0.5 microgram/0.5 microliter) and ritanserin (0.3 microgram/0.5 microliter and 0.6 microgram/0.5 microliter) did not have a significant effect by themselves on memory, and neither did they attenuate the memory-facilitating effect of fluoxetine in the same area. Intralateral septal infusions of 8-hydroxy-2-(di-n-propylamino)tetralin at 5 micrograms/0.5 microliter significantly impaired memory retention. These findings altogether support the notion that the lateral septal nuclei of rats are involved in the memory processes of inhibitory avoidance learning. Furthermore, postsynaptic 5HT receptor activation (not the 5HT2 receptor subtype) probably exerts a facilitatory effect while presynaptic 5HT1A receptor activation exerts an impairing effect on the memory consolidation process, probably due to autoreceptor inhibition of 5HT release.  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