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   1231篇
  免费   31篇
耳鼻咽喉   4篇
儿科学   22篇
妇产科学   20篇
基础医学   141篇
口腔科学   32篇
临床医学   111篇
内科学   209篇
皮肤病学   28篇
神经病学   103篇
特种医学   46篇
外科学   227篇
综合类   4篇
预防医学   79篇
眼科学   5篇
药学   75篇
肿瘤学   156篇
  2023年   2篇
  2022年   4篇
  2021年   8篇
  2020年   3篇
  2019年   9篇
  2018年   5篇
  2017年   3篇
  2016年   5篇
  2015年   20篇
  2014年   15篇
  2013年   22篇
  2012年   96篇
  2011年   127篇
  2010年   26篇
  2009年   27篇
  2008年   128篇
  2007年   122篇
  2006年   122篇
  2005年   96篇
  2004年   92篇
  2003年   89篇
  2002年   70篇
  2001年   18篇
  2000年   18篇
  1999年   20篇
  1998年   6篇
  1997年   6篇
  1996年   10篇
  1995年   4篇
  1994年   2篇
  1993年   5篇
  1992年   6篇
  1991年   9篇
  1990年   9篇
  1989年   8篇
  1988年   4篇
  1987年   4篇
  1986年   6篇
  1985年   7篇
  1984年   5篇
  1982年   2篇
  1981年   4篇
  1979年   4篇
  1978年   2篇
  1975年   2篇
  1974年   2篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1965年   1篇
排序方式: 共有1262条查询结果,搜索用时 0 毫秒
1.
Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring.  相似文献   
2.
Leukemic cells from two patients with Philadelphia-negative chronic myeloid leukemia (CML) were investigated: I) Cytogenetics showed a normal 46.XY karyotype in both cases, 2) molecular studies revealed rearrangement of the M-BCR region and formation of BCR-ABL fusion mRNA with b2a2 (patient I) or b3a2 (patient 2) configuration, and 3) fluorescence in situ hybridization (FISH) demonstrated relocation of the 5′ BCR sequences from one chromosome 22 to one chromosome 9. The ABL probe hybridized to both chromosomes 9 at band q34, while two other probes which map centromeric and telomeric of BCR on 22q 11 hybridized solely with chromosome 22. For the first time, a BCR-ABL rearrangement is shown to take place on 9q34 instead of in the usual location on 22q 11. A rearrangement in the latter site is found in all Ph-positive CML and in almost all investigated CML with variant Ph or Ph-negative, BCR-positive cases. The few aberrant chromosomal localizations of BCR-ABL recombinant genes found previously were apparently the result of complex and successive changes. Furthermore in patient 2, both chromosomes 9 showed positive FISH signals with both ABL and BCR probes. Restriction fragment length polymorphism (RFLP) analysis indicated that mitotic recombination had occurred on the long arm of chromosome 9 and that the rearranged chromosome 9 was of paternal origin. The leukemic cells of this patient showed a duplication of the BCR-ABL gene, analogous to duplication of the Ph chromosome in classic CML. In addition they had lost the maternal alleles of the 9q34 chromosomal region. The lymphocytes of patient 2 carried the maternal chromosome 9 alleles and were Ph-negative as evidenced by RFLP and FISH analyses, respectively. © 1993 Wiley-Liss, Inc.  相似文献   
3.
Fetal thrombosis of the dural sinus is an extremely rare congenital cerebrovascular condition that is potentially fatal. We report a case of dural sinus thrombosis diagnosed by prenatal ultrasonography and fetal magnetic resonance imaging (MRI) in the second trimester. The thrombosis showed partial resolution during pregnancy and resolved spontaneously after birth without neurological complications. This is the first report of spontaneous postnatal resolution, and may provide helpful information on the natural history and prenatal counseling of fetal thrombosis of the dural sinus.  相似文献   
4.
OBJECTIVE: This evaluated the long-term outcome after endoscopic thoracic sympathectomy (ETS) from below D1 to D4, using a single-site access technique for primary hyperhidrosis of the upper limbs. SUMMARY BACKGROUND DATA: Primary hyperhidrosis of the upper limbs is a distressing and often socially disabling condition. Endoscopic thoracic sympathectomy is considered the treatment of choice, causing minimal morbidity and high initial success rates. However, data regarding long-term results are scarce. METHODS: Two hundred seventy of 323 patients (83.7%), in whom 480 sympathectomies were performed, answered a questionnaire after a mean of 14.6 years postoperatively regarding the early postoperative result, side effects, and complications caused by the operation and long-term results with particular emphasis on patient satisfaction. RESULTS: There was no postoperative mortality and no major complications requiring surgical reintervention. A majority of the patients (98.1%) were relieved, and 95.5% were satisfied initially. Permanent side effects included compensatory sweating in 67.4%, gustatory sweating in 50.7% and Horner's trias in 2.5%. However, patient satisfaction declined over time, although only 1.5% recurred. This left only 66.7% satisfied, and a 26.7% partially satisfied. Compensatory and gustatory sweating were the most frequently stated reasons for dissatisfaction. Individuals operated for axillary hyperhidrosis without palmar involvement were significantly less satisfied (33.3% and 46.2%, respectively).  相似文献   
5.
The aim of this study was to estimate the incidence of morbidity and mortality due to injuries in the population over the age of 14 years in Barcelona, Spain. Injury distribution according to sex, age, external cause, place of occurrence of the injury and severity was also obtained. A one-year survey was conducted in the emergency departments of the six main hospitals in Barcelona, based on a multistage sampling. Information was collected prospectively in emergency services by specially trained non-staff interviewers. Mortality data were drawn from death certificates. The incidence rate was 74.7 injury cases per 1,000 person-years over 14 years of age, higher in males than in females. Injury rates were highest in the youngest age-group and progressively lower until people over 75 years of age. Main external causes of injury were falls, being struck or caught by objects, and traffic-related injuries. The leading specific causes of injury mortality were traffic injuries, suicides and poisonings. While the overall admission incidence was 3.34 cases per 1,000 inhabitants, the proportion of hospitalized cases was 45.0 per 1,000 injury cases admitted to emergency rooms, higher for females, for traffic injuries and in the elderly population. Ninety-six percent of injury cases had an ISS value of 8 or less, mean ISS being highest for traffic injuries and falls. Injury morbidity and mortality amongst residents of Barcelona follow sex, age and cause of injury patterns which are, overall, comparable to those observed in other industrialized countries, suggesting that similar etiologic factors might be operating in those areas. The results should enable the orientation of injury prevention policies in the urban environment targeted on the young and the elderly population.  相似文献   
6.
BACKGROUND: Severe acute respiratory syndrome (SARS) became a worldwide outbreak with a mortality of 9.2%. This new human emergent infectious disease is dominated by severe lower respiratory illness and is aetiologically linked to a new coronavirus (SARS-CoV). METHODS: Pulmonary pathology and clinical correlates were investigated in seven patients who died of SARS in whom there was a strong epidemiological link. Investigations include a review of clinical features, morphological assessment, histochemical and immunohistochemical stainings, ultrastructural study, and virological investigations in postmortem tissue. RESULTS: Positive viral culture for coronavirus was detected in most premortem nasopharyngeal aspirate specimens (five of six) and postmortem lung tissues (two of seven). Viral particles, consistent with coronavirus, could be detected in lung pneumocytes in most of the patients. These features suggested that pneumocytes are probably the primary target of infection. The pathological features were dominated by diffuse alveolar damage, with the presence of multinucleated pneumocytes. Fibrogranulation tissue proliferation in small airways and airspaces (bronchiolitis obliterans organising pneumonia-like lesions) in subpleural locations was also seen in some patients. CONCLUSIONS: Viable SARS-CoV could be isolated from postmortem tissues. Postmortem examination allows tissue to be sampled for virological investigations and ultrastructural examination, and when coupled with the appropriate lung morphological changes, is valuable to confirm the diagnosis of SARS-CoV, particularly in clinically unapparent or suspicious but unconfirmed cases.  相似文献   
7.
8.
Recent studies have provided evidence that macrophages from Th1-prone mouse strains respond with an M1 profile, and macrophages from Th2-prone mouse strains respond with an M2 profile, characterized by the dominant production of NO or TGF-beta 1, respectively. We have shown that peritoneal macrophages from IL-12p40 gene knockout mice have a bias toward the M2 profile, spontaneously secreting large amounts of TGF-beta 1 and responding to rIFN-gamma with weak NO production. Moreover, IL-12p40KO macrophages are more permissive to Trypanosoma cruzi replication than their wild-type littermate cells. Prolonged incubation with rIL-12 fails to reverse the M2 polarization of IL-12p40KO macrophages. However, TGF-beta 1 is directly implicated in sustaining the M2 profile because its inhibition increases NO release from IL-12p40KO macrophages. IFN-gamma deficiency is apparently not the reason for TGF-beta 1 up-regulation, because rIFN-gamma KO macrophages produce normal amounts of this cytokine. These findings raise the possibility that IL-12 has a central role in driving macrophage polarization, regulating their intrinsic ability to respond against intracellular parasites.  相似文献   
9.
10.
Factor VIII activity and factor VIII related--or Willebrand--antigen were studied in 49 known carriers of haemophilia A and 31 normal women, and the data were analysed by four statistical approaches. Sixteen per cent of normals and 18% of carriers were misclassified, overlapping with the other group. Although the percentage of carriers detected is higher when taking into account the results of both biological and immunological factor VIII, it is lower than others recently reported, and the discrepancies between the results obtained are discussed.  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