全文获取类型
收费全文 | 23436篇 |
免费 | 1444篇 |
国内免费 | 77篇 |
专业分类
耳鼻咽喉 | 309篇 |
儿科学 | 457篇 |
妇产科学 | 536篇 |
基础医学 | 3092篇 |
口腔科学 | 1682篇 |
临床医学 | 1730篇 |
内科学 | 5317篇 |
皮肤病学 | 519篇 |
神经病学 | 1825篇 |
特种医学 | 507篇 |
外国民族医学 | 1篇 |
外科学 | 2906篇 |
综合类 | 140篇 |
一般理论 | 8篇 |
预防医学 | 2110篇 |
眼科学 | 514篇 |
药学 | 1869篇 |
中国医学 | 158篇 |
肿瘤学 | 1277篇 |
出版年
2023年 | 183篇 |
2022年 | 496篇 |
2021年 | 890篇 |
2020年 | 533篇 |
2019年 | 714篇 |
2018年 | 848篇 |
2017年 | 604篇 |
2016年 | 654篇 |
2015年 | 770篇 |
2014年 | 976篇 |
2013年 | 1241篇 |
2012年 | 1722篇 |
2011年 | 1863篇 |
2010年 | 986篇 |
2009年 | 844篇 |
2008年 | 1317篇 |
2007年 | 1301篇 |
2006年 | 1168篇 |
2005年 | 1053篇 |
2004年 | 882篇 |
2003年 | 826篇 |
2002年 | 702篇 |
2001年 | 472篇 |
2000年 | 445篇 |
1999年 | 358篇 |
1998年 | 137篇 |
1997年 | 127篇 |
1996年 | 112篇 |
1995年 | 93篇 |
1994年 | 83篇 |
1993年 | 80篇 |
1992年 | 232篇 |
1991年 | 216篇 |
1990年 | 208篇 |
1989年 | 167篇 |
1988年 | 161篇 |
1987年 | 117篇 |
1986年 | 134篇 |
1985年 | 127篇 |
1984年 | 94篇 |
1983年 | 75篇 |
1982年 | 64篇 |
1981年 | 52篇 |
1979年 | 103篇 |
1978年 | 50篇 |
1977年 | 53篇 |
1976年 | 54篇 |
1975年 | 62篇 |
1974年 | 59篇 |
1973年 | 50篇 |
排序方式: 共有10000条查询结果,搜索用时 20 毫秒
81.
Polymorphism of the Mouse H-2 Loci 总被引:7,自引:0,他引:7
82.
Calabrese KS Paradela AS do Valle TZ Tedesco RC Leonardo R Mortara RA Gonçalves da Costa SC 《Pathologie-biologie》2003,51(3):129-134
In this article, we have characterized cell subpopulations found in the hearts of mice presenting acute Chagas' disease by immunocytochemistry and subjected to different schedules of an immunosuppressive therapy with cyclophosphamide (CY). In this comparative study, CY treatment with different doses was carried out before or after infection with Trypanosoma cruzi Y strain trypomastigotes, enabling us to discriminate the parasitemic kinetics and inflammatory processes in the heart, 12 d after infection. Animals treated with 200 mg/kg of CY 2 d before infection presented high parasitaemia as well as heavy inflammation and low parasite loads in the heart. Mice treated 5 d after infection with the same dose, developed the same parasitaemic peak but were not able to control it. Their heart did not present inflammation, but a high number of parasites could be seen. Animals treated with five 3 mg/kg doses of CY every other day presented heavy inflammatory reaction and low parasitaemia. In this group, as well as the one treated before infection, immunocytochemistry studies have shown predominance of CD8(+) T cells in the myocardium. On the other hand, mice treated with 200 mg/kg of CY 5 d after infection, presented small amounts of CD4(+) T cells while no CD8(+) could be found. These results have confirmed the dose dependence influence of this drug on the T cell populations in the inflammatory infiltrates as well as the importance of the schedule employed. 相似文献
83.
Pardono E van Bever Y van den Ende J Havrenne PC Iughetti P Maestrelli SR Costa F O Richieri-Costa A Frota-Pessoa O Otto PA 《American journal of medical genetics. Part A》2003,(3):223-235
Here we present the results of a study performed on 59 patients affected by Waardenburg syndrome (WS), 30 with the I variant, 21 having the type II, and 8 of them being isolated cases without telecanthus. These patients belong to 37 families; the main contributions and conclusions are based on the detailed study of 25 of these families, examined using standard procedures. All patients were examined as to the presence of eight cardinal signs important for the diagnosis of the condition; from each patient, from many of his/her normal relatives, and from a control sample of 300 normal individuals stratified by age and sex, 23 different craniofacial measurements were obtained. We also estimated, using our own data as well those collected from the literature, the frequencies of the cardinal signs, based on a total sample of 461 affected individuals with WSI and 121 with WSII. In order to originate discriminant functions to separate individuals affected by one of the two variants, both metric (from craniofacial measurements) as well as categoric data (based on the frequencies of the cardinal signs or symptoms) were used. Discriminant analysis based on the frequency of the eight cardinal signs can improve the separation of WSI patients without telecanthus from those presenting the variant II. We present also a Table with the conditional probabilities favoring the diagnosis of WSI for suspect subjects without telecanthus and any combination of the other seven signs/symptoms. The discriminant function based on the four ocular measurements (inner and outer intercanthal, interpupillary, and inferior lacrymal distances), on the other side, perfectly classifies patients affected by one of the variants of WS, the same taking place when the average values of the W index of all affected individuals per family are used. The discriminant function based solely in the individual W index values of patients correctly classifies 93% of WSII subjects, but only 60% of the patients with the I variant of WS. 相似文献
84.
Effect of platelet-derived growth factor on the development and persistence of asbestos-induced fibroproliferative lung disease. 总被引:1,自引:0,他引:1
Jian Li Halet G Poovey Juan Felipe Rodriguez Arnold Brody Gary W Hoyle 《Journal of environmental pathology, toxicology and oncology》2004,23(4):253-266
Platelet-derived growth factor (PDGF) isoforms and PDGF receptor-alpha are upregulated in fibroproliferative lesions in response to asbestos exposure. To examine the functional role of PDGF in asbestos-induced lung disease, we have evaluated the impact of PDGF-B overexpression in the lung on the development of pulmonary fibrosis induced by asbestos inhalation. Transgenic mice expressing PDGF-B from the surfactant protein C promoter and wild-type C57BL/6 mice were exposed to aerosolized chrysotile asbestos fibers via three different exposure regimens: 3 consecutive days to 9 mg/m(3), once a week for 5 weeks to 12 mg/m(3), or once a week for 8 weeks to 11 mg/m(3). The 3-day exposure did not produce fibroproliferative lesions in SPC-PDGFB or wild-type mice, indicating that PDGF expression did not increase susceptibility to a subthreshold dose of asbestos. Transgenic and wild-type mice subjected to the 5-week exposure protocol exhibited similar fibrogenic lesions histologically 48 hours and 8 weeks postexposure, but lungs from transgenic mice had elevated lung hydroxyproline content 8 weeks postexposure relative to wild-type mice. In addition, SPC-PDGFB transgenic mice developed pronounced thickening of arterioles following the 5-week exposure regimen. Mice exposed to asbestos for 8 weeks and examined 10 months later showed pronounced, diffuse fibrotic lesions of terminal bronchioles and alveolar ducts, but no histological differences between transgenic and nontransgenic mice were observed. These results indicated that PDGF-B overexpression can stimulate increased collagen deposition and vascular smooth muscle hyperplasia following asbestos inhalation and that a limited exposure (8 times) to chrysotile aerosol can produce long-lasting fibrotic lesions. The 8-week exposure regimen provides an animal model that encompasses an important aspect of human asbestosis-i.e., persistence of fibrosis for long periods after cessation of asbestos exposure. 相似文献
85.
Nguyen Khac F Waill MC Romana SP Radford-Weiss I Busson M Collonge-Rame MA Ribadeau-Dumas A Piffaut MC Daniel MT Davi F Merle-Béral H Berger R Arock M 《Cancer Genetics and Cytogenetics》2002,138(1):22-26
Two patients with Ph-positive chronic myelocytic leukemia in erythroblastic transformation and rearrangement of the short arm of chromosome 18 are reported. Fluorescence in situ hybridization studies showed that the 18p rearrangement resulted from translocation of the main part of chromosome 22 long arm to 18p, including BCR-ABL1 fusion. The 18p abnormality resulted, thus, in loss of 18p and duplication of BCR-ABL1 in both patients. The possible relation to the erythroblastic type of blastic phase is briefly discussed. In addition an apparently intact germline ABL1 gene was duplicated and inserted into chromosome 6 at band p21 in one of these patients. 相似文献
86.
Antibodies to staphylococcal enterotoxins and toxic shock syndrome toxin 1 in sera of patients and healthy people in Rio de Janeiro, Brazil. 总被引:3,自引:0,他引:3 下载免费PDF全文
A L Solino Noleto E da Costa Cesar M S Bergdoll 《Journal of clinical microbiology》1986,24(5):809-811
Sera from 33 persons with staphylococcal infections and from 37 healthy persons were surveyed for the presence of antibody to staphylococcal enterotoxins A, B, C, D, and E and toxic shock syndrome toxin 1. Thirty-one (93.9%) of the patients and 35 (94.6%) of the control group had antibodies to one or more of the enterotoxins. The numbers of patients with antibody to the enterotoxins were as follows: A, 8; B, 9; C, 7; D, 17; E, 21; and toxic shock syndrome toxin 1, 11. The numbers of healthy individuals with antibody to the enterotoxins were as follows: A, 6; B, 12; C, 8; D, 27; E, 21; and toxic shock syndrome toxin 1, 9. 相似文献
87.
Leal GF Roberts E Silva EO Costa SM Hampshire DJ Woods CG 《Journal of medical genetics》2003,40(7):540-542
88.
R Bernardini C E Fiore L Insirello M Pistritto V Costa G Clementi 《International journal of tissue reactions》1992,14(1):25-29
We have studied the effect of intravenous injection of eel calcitonin (ECT) on creatine kinase E.C.2.7.3.2. BB isozyme (CKBB) in the kidney of male Wistar rats. CKBB immunoreactivity was detected by the peroxidase-antiperoxidase method. Eel calcitonin increased CKBB immunoreactivity in the renal medulla in a dose-dependent fashion. Its effect peaked at 2 h and lasted up to 24 h. The distribution of activated CKBB in the kidney occurs in the same areas where highly specific CT-binding sites have been previously demonstrated, and is in agreement with the current concepts on renal actions of this hormone. 相似文献
89.
90.
A group of 83 men and women who had been referred to Johns Hopkins Hospital for cardiac catheterization for evaluation of chest pain and possible coronary artery bypass surgery were assessed behaviorally for their chest pains. During the approximately 2-week period between clinical evaluation and catheterization, the patients completed self-report forms about their chest pains. Patients completed one form for each episode of chest pain. Referring physicians also completed a form about the patients "typical" chest pain. The data were analyzed in terms of the antecedents, concomitants, and consequences of the chest pain, and patients' reports were compared to physicians' judgments. Major findings were as follows: 1) Antecedents--most episodes occurred while the patient was at home at times when his mood was one of contentment. 2) Concomitants--the average patient reported fewer than one episode per day which persisted for about 4 min and was rated as 36 on a scale of 0 to 100. The most common physical symptoms accompanying the episode were breathlessness and weakness, and the most common pain sensations were reported to be pressing or aching. There was no consistency among patients either in primary location or path of radiation of the pain. Duration of pain did not correlate significantly either with sensation or symptoms; however, severity rating did correlate with symptoms and sensations. 3) Consequences--most episodes were self-treated with nitroglycerin or rest. Patients typically returned to their ongoing activities; however, there were a number of interactions between the likelihood of returning to ones ongoing activity and the antecedents of the episodes. 4) The referring physicians significantly overestimated the frequency and severity of their patients' episodes; furthermore, they were selective in their abilities to identify correctly the antecedents or concomitants associated with their patients' pain--e.g., they were reliable in their judgments about subjects who had sleep-related episodes; however, they were inaccurate in characterizing the typical sensations or symptoms reported by their patients. It is suggested that a behavioral analysis may enable a physician to characterize his patient's chest complaints better, and perhaps also may facilitate the differentiation between chest complaints indicative of coronary artery disease and chest complaints of a noncoronary origin. 相似文献