全文获取类型
收费全文 | 22777篇 |
免费 | 2171篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 237篇 |
儿科学 | 713篇 |
妇产科学 | 670篇 |
基础医学 | 3039篇 |
口腔科学 | 346篇 |
临床医学 | 3092篇 |
内科学 | 4367篇 |
皮肤病学 | 355篇 |
神经病学 | 1911篇 |
特种医学 | 868篇 |
外国民族医学 | 3篇 |
外科学 | 2716篇 |
综合类 | 533篇 |
一般理论 | 14篇 |
预防医学 | 2282篇 |
眼科学 | 729篇 |
药学 | 1620篇 |
中国医学 | 22篇 |
肿瘤学 | 1479篇 |
出版年
2023年 | 128篇 |
2022年 | 148篇 |
2021年 | 324篇 |
2020年 | 272篇 |
2019年 | 379篇 |
2018年 | 428篇 |
2017年 | 371篇 |
2016年 | 411篇 |
2015年 | 494篇 |
2014年 | 655篇 |
2013年 | 908篇 |
2012年 | 1253篇 |
2011年 | 1357篇 |
2010年 | 728篇 |
2009年 | 760篇 |
2008年 | 1122篇 |
2007年 | 1276篇 |
2006年 | 1206篇 |
2005年 | 1213篇 |
2004年 | 1171篇 |
2003年 | 1019篇 |
2002年 | 1009篇 |
2001年 | 482篇 |
2000年 | 483篇 |
1999年 | 527篇 |
1998年 | 392篇 |
1997年 | 327篇 |
1996年 | 332篇 |
1995年 | 292篇 |
1994年 | 235篇 |
1993年 | 199篇 |
1992年 | 330篇 |
1991年 | 332篇 |
1990年 | 305篇 |
1989年 | 323篇 |
1988年 | 294篇 |
1987年 | 263篇 |
1986年 | 301篇 |
1985年 | 263篇 |
1984年 | 219篇 |
1983年 | 171篇 |
1982年 | 174篇 |
1981年 | 135篇 |
1980年 | 138篇 |
1979年 | 198篇 |
1978年 | 159篇 |
1977年 | 124篇 |
1976年 | 114篇 |
1974年 | 115篇 |
1973年 | 134篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Elliott AM Graham JM Curry CJ Pal T Rimoin DL Lachman RS 《American journal of medical genetics》2002,113(4):351-361
Dolichospondylic dysplasia (DD) is a rare skeletal dysplasia primarily characterized by tall vertebral bodies and disproportionate short stature. Radiographic manifestations include tall vertebral bodies and gracile bones of the hands. Patients usually have eye and ear findings in addition to borderline mental retardation; however, tall vertebral bodies and slender tubular bones are also seen in the 3-M syndrome. Patients with the 3-M syndrome have a characteristic face with a triangular shape, frontal bossing, a flattened malar region, full eyebrows, a short nose with a bulbous tip, upturned nares, and full lips. We present two unrelated patients who share a distinct phenotype and have tall vertebral bodies, overtubulation of long bones, and short tubular bones of the hands and feet. We discuss the overlapping and distinguishing features between DD and the 3-M syndrome. Patient 1 was a 13-year-old female, and patient 2 was an unrelated adult female. These patients had normocephaly and short stature. They shared a common phenotype consisting of mild malar hypoplasia, a narrowed nasal body with a fleshy tip, full lips, and normal intelligence. In addition, they showed mild hand and foot abnormalities. These two patients lack many of the typical clinical features of both DD and the 3-M syndrome. They share a common phenotype and likely represent a distinct disorder. The spectrum of disorders with tall vertebral bodies as a key feature may include different entities that may be further defined with the characterization of the molecular defect(s). 相似文献
82.
Peebles RS Sheller JR Collins RD Jarzecka AK Mitchell DB Parker RA Graham BS 《Journal of medical virology》2001,63(2):178-188
Severe respiratory syncytial virus (RSV)-induced disease is associated with childhood asthma and atopy. We combined murine models of allergen-sensitization and RSV infection to explore the interaction of allergic and virus-induced airway inflammation and its impact on airway hyperresponsiveness (AHR). We found that RSV infection during ova-sensitization (OVA/RSV) increased and prolonged AHR compared to mice only RSV-infected (RSV) or ova-sensitized (OVA). AHR is known to be associated with an increase in Type 2 cytokines (IL-4, IL-5, and IL-13) in allergen-sensitized mice. Therefore, we hypothesized that RSV-induced enhancement of AHR was a result of potentiating the Type 2 cytokine profile promoted by ova-sensitization. Surprisingly, we found that Type 2 cytokines induced by ova-sensitization were not increased by RSV infection despite the increase in AHR, and in some cases were diminished. RNAse protection assay revealed no difference in IL-4 and IL-5 mRNA levels between the OVA and OVA/RSV groups, and IL-13 mRNA was significantly decreased in the OVA/RSV mice compared to the OVA group. Flow cytometric analysis of Type 2 cytokines demonstrated the same frequency of IL-4 and IL-5 production in lung-derived T lymphocytes from the OVA/RSV and OVA groups. Direct cytokine ELISA measurements of lung supernatant showed the level of IL-13 was significantly decreased in the OVA/RSV group compared to OVA mice, while there was no difference in either IL-4 or IL-5 between these two groups. These data indicate that the enhanced and prolonged AHR caused by the interaction of allergic airway inflammation and virus-induced immune responses is a complex process that can not be explained simply by augmented production of Type 2 cytokines. 相似文献
83.
M Avellanet RM Mirapeix D Escudero C Riera JM Domenech-Mateu 《Surgical and radiologic anatomy : SRA》1996,18(4):271-273
Summary We present a case with a characteristic magnetic resonance image (MRI) of bilateral open-lipped schizencephaly and atypical clinical presentation. The patient is still alive and in good health in her forties, she has never presented seizures, and although the motor dysfunction is well correlated with cerebral lobe involvement, neurobehavioral dysfunction is not proportional to the MR image of the cerebral malformation.
Un cas inhabituel de schizencéphalie bilatérale
Résumé Nous présentons un cas de schizencéphalie bilatérale ouverte caractérisé par une présentation clinique atypique et une imagerie par résonance magnétique nucléaire caractéristique. La patiente est encore vivante, en bonne santé, à plus de 40 ans, elle n'a jamais présenté de crise comitiale et, bien que les troubles moteurs soient bien corrélés aux altérations cérébrales, les troubles neuro-comportementaux ne sont pas proportionnels aux images IRM de cette malformation cérébrale.相似文献
84.
85.
Characterization of a Helicobacter pylori neutrophil-activating protein. 总被引:25,自引:0,他引:25 下载免费PDF全文
D J Evans Jr D G Evans T Takemura H Nakano H C Lampert D Y Graham D N Granger P R Kvietys 《Infection and immunity》1995,63(6):2213-2220
Helicobacter pylori-associated gastritis is mainly an inflammatory cell response. In earlier work we showed that activation of human neutrophils by a cell-free water extract of H. pylori is characterized by increased expression of neutrophil CD11b/CD18 and increased adhesiveness to endothelial cells. The work reported here indicates that the neutrophil-activating factor is a 150,000-molecular-weight protein (150K protein). Neutrophil proadhesive activity copurified with this protein, which is a polymer of identical 15K subunits. Specific antibody, prepared against the purified 15K subunit, neutralized the proadhesive activity of the pure protein and of water extracts obtained from different strains of H. pylori. The gene (napA) for this protein (termed HP-NAP, for H. pylori neutrophil-activating protein) was detected, by PCR amplification, in all of the H. pylori isolates tested; however, there was considerable strain variation in the level of expression of HP-NAP activity in vitro. HP-NAP could play an important role in the gastric inflammatory response to H. pylori infection. 相似文献
86.
Much has been written about social worker/general-practitioner collaboration, particularly about conflict of roles, differing functions, avenues of accountability, and problems of distributing scarce resources.
We suggest that if the two professions are to work more comfortably together, then it is imperative that both also share the despair, hopelessness, anxiety, and anger that are the occupational hazards of each. We suggest ways in which doctors and social workers can look at the pain their patients are suffering to the benefit of the patient and their own working relationship.
相似文献87.
Electrodermal Lability and Visual Information Processing 总被引:1,自引:0,他引:1
Individual differences in electrodermal lability have been related to performance in vigilance and reaction time tasks. The goal of the present study was to employ an "additive factors" approach to identify the stages of information processing that might underlie these effects. Nineteen labile and 17 stabile subjects performed a choice reaction time task in which a visual imperative stimulus was presented under two conditions of intensity (presumed to affect the speed of pre-processing operations) X three conditions of degradation (which influences later encoding processes related to feature extraction). Measures of both reaction time and movement time were obtained. The major findings were: (a) labile subjects had faster reaction times than stabiles, and (b) lability interacted significantly with stimulus degradation. Labiles also tended (p less than .10) to have faster movement times. This pattern indicates that labiles and stabiles differ in the performance of later encoding operations, and possibly in the speed of motor processes as well. However, they do not appear to differ in the early pre-processing of the simple physical attributes of a stimulus. 相似文献
88.
89.
Mycobacterium avium complex pseudobacteriuria from a hospital water supply. 总被引:2,自引:2,他引:2 下载免费PDF全文
From July 1983 through November 1985, organisms belonging to Mycobacterium avium complex were isolated from the urine of 29 patients. Strains recovered from the urine of nine patients from July 1983 through August 1984 were serotyped. Eight of the nine samples belonged to serovar 4. M. avium complex was isolated from the urine of 21 patients during the period from November 1984 through November 1985. While the possibility of a point source contamination was investigated, M. avium complex was recovered from the phenol red solution used for processing urine specimens in the mycobacteriology laboratory and the deionized tap water of that laboratory that is used to make the reagent. M. avium complex serovar 4 was subsequently recovered from the tap water of the laboratory and four hospital wards. During the year following the installation of a microbiological filter for the mycobacteriology laboratory deionized tap water, 2 urine isolates were recovered, compared to 26 the previous year. This study demonstrates the importance of filtration devices at tap water sites that are used to make laboratory reagents and the value of serotyping as a marker for the detection of a specific source of M. avium complex contamination. 相似文献
90.
Molecular mechanisms of inherited cardiomyopathies 总被引:28,自引:0,他引:28
Cardiomyopathies are diseases of heart muscle that may result from a diverse array of conditions that damage the heart and other organs and impair myocardial function, including infection, ischemia, and toxins. However, they may also occur as primary diseases restricted to striated muscle. Over the past decade, the importance of inherited gene defects in the pathogenesis of primary cardiomyopathies has been recognized, with mutations in some 18 genes having been identified as causing hypertrophic cardiomyopathy (HCM) and/or dilated cardiomyopathy (DCM). Defining the role of these genes in cardiac function and the mechanisms by which mutations in these genes lead to hypertrophy, dilation, and contractile failure are major goals of ongoing research. Pathophysiological mechanisms that have been implicated in HCM and DCM include the following: defective force generation, due to mutations in sarcomeric protein genes; defective force transmission, due to mutations in cytoskeletal protein genes; myocardial energy deficits, due to mutations in ATP regulatory protein genes; and abnormal Ca2+ homeostasis, due to altered availability of Ca2+ and altered myofibrillar Ca2+ sensitivity. Improved understanding that will result from these studies should ultimately lead to new approaches for the diagnosis, prognostic stratification, and treatment of patients with heart failure. 相似文献