全文获取类型
收费全文 | 19161篇 |
免费 | 1200篇 |
国内免费 | 134篇 |
专业分类
耳鼻咽喉 | 162篇 |
儿科学 | 444篇 |
妇产科学 | 363篇 |
基础医学 | 2203篇 |
口腔科学 | 749篇 |
临床医学 | 1802篇 |
内科学 | 4233篇 |
皮肤病学 | 422篇 |
神经病学 | 1163篇 |
特种医学 | 455篇 |
外国民族医学 | 5篇 |
外科学 | 2498篇 |
综合类 | 489篇 |
一般理论 | 14篇 |
预防医学 | 1590篇 |
眼科学 | 732篇 |
药学 | 1806篇 |
中国医学 | 214篇 |
肿瘤学 | 1151篇 |
出版年
2024年 | 20篇 |
2023年 | 222篇 |
2022年 | 557篇 |
2021年 | 1093篇 |
2020年 | 716篇 |
2019年 | 861篇 |
2018年 | 1022篇 |
2017年 | 725篇 |
2016年 | 780篇 |
2015年 | 788篇 |
2014年 | 1067篇 |
2013年 | 1231篇 |
2012年 | 1689篇 |
2011年 | 1728篇 |
2010年 | 1013篇 |
2009年 | 780篇 |
2008年 | 1158篇 |
2007年 | 1021篇 |
2006年 | 856篇 |
2005年 | 733篇 |
2004年 | 576篇 |
2003年 | 488篇 |
2002年 | 424篇 |
2001年 | 70篇 |
2000年 | 81篇 |
1999年 | 77篇 |
1998年 | 59篇 |
1997年 | 49篇 |
1996年 | 46篇 |
1995年 | 40篇 |
1994年 | 22篇 |
1993年 | 37篇 |
1992年 | 35篇 |
1991年 | 32篇 |
1990年 | 31篇 |
1989年 | 28篇 |
1988年 | 26篇 |
1987年 | 26篇 |
1986年 | 24篇 |
1985年 | 24篇 |
1984年 | 30篇 |
1983年 | 28篇 |
1982年 | 21篇 |
1981年 | 14篇 |
1980年 | 14篇 |
1979年 | 14篇 |
1978年 | 13篇 |
1975年 | 12篇 |
1974年 | 16篇 |
1973年 | 19篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
Objective: To find out the spectrum of various histopathologic types of primary neoplasms of different parts of the gastrointestinal tract (oesophagus, stomach, small intestine, colorectum, anal canal) seen at the Kathmandu University Teaching Hospital (KUTH), Dhulikhel as there exists a worldwide wide variation in the distribution of various neoplasms of different parts of the gastrointestinal tract, which appears largely due to exogenous factors rather than due to inherent differences between populations. Materials and methods: This was a retrospective study. It was carried out at Kathmandu University Teaching Hospital (KUTH), Dhulikhel, Kavre, Nepal. All neoplasms of the gastrointestinal tract seen at the KUTH during the period 1st January 2004 to 31st December 2004 were included in this study and examined by light microscope (LM). Results: A total number of 18 cases of neoplasms of the gastrointestinal tract were seen. Out of these, 3 (16.7%) were of the oesophagus (all squamous cell carcinoma), 10 (55.5%) were of the stomach (six intestinal type and four diffuse type), 2 (11.1%) were of the small intestine (one was lymphoma of the mucosa associated lymphoid tissue - MALTOMA and other was a malignant gastrointestinal stromal tumour - GIST), 3 (16.7%) were of the colorectum (all adenocarcinoma), and none was of the anal canal. Conclusion: Relatively large number of cases of the carcinoma of the stomach were found in our this small series of the cases of the gastrointestinal tract in comparison to the Western countries. Key words: Neoplasms, gastrointestinal tract, gastric carcinoma intestinal type, gastric carcinoma diffuse type, Kathmandu University Teaching Hospital (KUTH). 相似文献
32.
R Bassan P E Cornelli R Battista F Terzi M Buelli A Rambaldi P Viero A D'Emilio E Dini T Barbui 《Hematological oncology》1992,10(2):105-110
Twenty-three patients (16 adults) failing their first or subsequent (n = 8) intensive treatment for de novo acute lymphoblastic leukemia (ALL) and chronic myeloid leukemia lymphoid blast phase (n = 2) were managed with protocol POG 8201, originally introduced in relapsed ALL of childhood. In this programme, a four-drug induction phase is followed by early consolidation with teniposide-cytarabine, intrathecal chemotherapy, continuation weekly chemotherapy alternating teniposide-cytarabine with vincristine-cyclophosphamide, and periodic reinduction courses. Fourteen adults and five children with ALL achieved a complete response (CR) (86 per cent). The highest response rate (100 per cent) was obtained in 12 patients treated at first relapse after an initial CR of greater than 18 months (p = 0.07). Median duration of CR was 8 months in adults and 11 months in children. A longer than previous one CR (inversion) was obtained in four cases. Four ALL patients were successfully transplanted from a matched sibling after 3-11 months from achievement of CR. Median overall survival in adults with ALL was 11 months, significantly longer than for 40 comparable cases treated intensively but without rotational continuation therapy in previous years (p less than 0.001). This regimen is applicable to adults with relapsed ALL, where prolongation of survival may allow time for effective salvage with bone marrow transplantation. 相似文献
33.
A new human cell line, WSU-BL, was established from a malignant ascitic fluid occurring in a patient with Burkitt's lymphoma. The established line grows in a single-cell suspension with a doubling time of 19 hours and expresses L3 morphologic features by the French-American-British classification. Immunologic study revealed that WSU-BL cells express IgM-lambda both in the cytoplasm and on the surface and react with monoclonal antibodies to B-cell antigens (B1, B4, BL3, BL4, HLA-DR, and common acute lymphoblastic leukemia antigen [CALLA]). These cells are negative for T-cell and myeloid/monocyte antigens as well as Epstein-Barr virus nuclear antigen (EBNA). These results suggest that WSU-BL corresponds to an intermediate stage of B-cell differentiation. Both fresh tumor and WSU-BL cells had a hyperdiploid karyotype carrying the 8;14 chromosome translocation. Molecular studies showed that WSU-BL has a rearrangement of c-myc proto-oncogene and expresses c-myc RNA. Phorbol ester 12-0-tetradecanoylphorbol-13-acetate (TPA) and interferon-gamma (IFN-gamma) were able to induce several phenotypic changes on WSU-BL cells. Two-dimensional gel electrophoresis of total cellular protein showed that either TPA or IFN-gamma induced both the synthesis or loss of several proteins. Analysis of the protein patterns indicated that some proteins were uniquely responsive to either TPA or IFN-gamma and others were common to both. This cell line should be valuable for future studies of cell proliferation, differentiation, and oncogenesis concerning this neoplasm. 相似文献
34.
Jamal M. Arif Sikandar G. Khan Mohammad Aslam Nayyara Mahmood Qamar Rahman 《Basic & clinical pharmacology & toxicology》1992,71(1):37-40
Abstract: In order to determine the pulmonary toxicity of kerosene and its ignition product (soot) in asbestos exposed subjects, the activities of phase I and phase II drug metabolizing enzymes in rat lungs after single intratracheal coexposure to Indian chrysotile asbestos and kerosene or its soot and Indian chrysotile were assayed. Exposure to kerosene or its soot resulted in a significant increase in the level of microsomal cytochrome P-450 and the activity of P-450 dependent monooxygenase, benzo(a)pyrene hydroxylase, as well as in the activities of microsomal epoxide hydrase and cytosolic glutathione-S-transferase (GST). However, in chrysotile exposed animals a reverse pattern in these parameters was recorded. The co-exposure to chrysotile and kerosene or chrysotile and soot led to a significant depletion in cytochrome P-450 level and a decrease in the activities of benzo(a)pyrene hydroxylase, epoxide hydrase and GST when compared to kerosene and soot controls, respectively. These results suggest that asbestos by altering the pulmonary drug metabolizing enzyme system may increase the toxic potential of kerosene and its ignition product in the respiratory system. 相似文献
35.
William Davies Mohammad Jazayeri Patrick Tchou 《Cardiovascular drugs and therapy / sponsored by the International Society of Cardiovascular Pharmacotherapy》1988,2(3):283-286
Summary Encainide is a type Ic antiarrhythmie agent. During encainide therapy, mild Q-T interval prolongation can be seen, usually associated with prolongation of the Q-R-S interval. The present case report describes an unusual and marked prolongation of the Q-T interval with no Q-R-S interval prolongation in a patient who was treated with encainide for atrioventricular nodal reentrant tachycardia. The drug metabolite profile in this patient's serum indicated an unusual elevation of the 3-methoxy-O-demethyl encainide metabolite, versus O-demethyl encainide. This elevated metabolite level suggests that 3-methoxy-O-demethyl encainide has a significant effect on prolongation of repolarization. An abnormal metabolism of encainide may be the underlying mechanism by which some patients would manifest an unusual prolongation of Q-T interval during encainide therapy. 相似文献
36.
37.
38.
Mohammad Diab Jiann-Jiu Wu Frederic Shapiro David Eyre 《American journal of medical genetics. Part A》1994,49(4):402-409
There is growing evidence that a spectrum of chondrodysplasias are caused by mutations in the gene coding for type II collagen. The basic molecular defect in diastrophic dysplasia has not been defined, but it appears not to be in collagen type II. Cartilage contains other tissue-specific collagens, types IX, X, and XI, but no mutations have yet been found in their genes in clinical disease. Type IX collagen is hypothesized to play a role in the regulation of type II collagen fibril organization and structure in cartilage extracellular matrix. In this study, we have examined iliac crest growth cartilage from a patient with diastrophic dysplasia. Although collagen fibrils were markedly increased in diameter on transmission electron microscopy, type II collagen appeared to be normal biochemically. Type XI collagen was also normal. However, type IX collagen appeared abnormal on sodium dodecyl sulfate polyacrylamide gel electrophoresis with a pronounced excess of the COL1 domain of the molecule in pepsin extracts. The findings point to an abnormality in structure or metabolism of type IX collagen in diastrophic dysplasia. © 1994 Wiley-Liss, Inc. 相似文献
39.
C. C. Obihara N. Beyers R. P. Gie M. O. Hoekstra J. E. Fincham B. J. Marais C. J. Lombard L. A. Dini J. L. L. Kimpen 《Clinical and experimental allergy》2006,36(5):640-648
BACKGROUND: Epidemiological relation of intestinal helminth infection and atopic disease, both associated with a T-helper (Th) 2 immune response, is controversial, as it has been reported that helminth infection may either suppress or pre-dispose to atopic disease. This relation has not been tested in an area with a high burden of Mycobacterium tuberculosis (MTB) infection, a known Th1-stimulating infection. OBJECTIVE: To study the association of intestinal helminth infection and atopic disease in a community where helminth infection is endemic and MTB infection is high. METHODS: Three-hundred and fifty-nine randomly selected children aged 6-14 years from a poor urban suburb were tested with allergy questionnaire, skin prick test (SPT) to common aeroallergens, Ascaris-specific IgE (Ascaris-sIgE), fecal examination for pathogenic intestinal helminths and tuberculin skin testing (TST). Histamine bronchoprovocation was tested in the group of children aged 10 years and older. RESULTS: were corrected for demographic variables, socioeconomic status, parental allergy, environmental tobacco smoke (ETS) exposure in the household, recent anthelminthic treatment and for clustering in the sampling unit. Results Ascaris-sIgE was elevated in 48% of children, Ascaris eggs were found in 15% and TST was positive in 53%. Children with elevated Ascaris-sIgE had significantly increased risk of positive SPT to aeroallergens, particularly house dust mite, atopic asthma (ever and recent), atopic rhinitis (ever and recent) and increased atopy-related bronchial hyper-responsiveness. In children with negative TST (<10 mm), elevated Ascaris-sIgE was associated with significantly increased risk of atopic symptoms (adjusted odds ratio (OR(adj)) 6.5; 95% confidence interval (CI) 1.9-22.4), whereas in those with positive TST (>/=10 mm) this association disappeared (OR(adj) 0.96; 95% CI 0.4-2.8). CONCLUSIONS: These results suggest that immune response to Ascaris (Ascaris-sIgE) may be a risk factor of atopic disease in populations exposed to mild Ascaris infection and that MTB infection may be protective against this risk, probably by stimulation of anti-inflammatory networks. 相似文献
40.
Despite the controversy of airway responsiveness to beta2-agonist drugs in asthma, in a previous study we showed increased responsiveness of asthmatic airways to isoprenaline. Therefore, in the present study of airway sensitivity to other beta2-agonists, salbutamol and its relationship to histamine responsiveness was reexamined. The threshold bronchodilator concentrations of inhaled salbutamol required for a 20% increase in forced expiratory flow in 1 sec (FEV1), (PC20) was measured in 20 normal and 19 asthmatic adults. Airway responsiveness to histamine, as the concentration that caused a 20% decrease in FEV1, was also measured in 11 normal and 12 asthmatic subjects; and the correlation between PC20 salbutamol and PC20 histamine was evaluated. Sensitivity to salbutamol was greater in asthmatics (PC20 = 7.24 mg/L) than in non-asthmatics (PC20 = 124.25 mg/L, p < 0.001). Airway responsiveness to histamine in asthmatics (PC20 = 0.18 g/L) was also significantly greater than in normal subjects (PC20 = 19.46 g/L, p < 0.001). There was a significant correlation between PC20 salbutamol and histamine (Rs = 0.6052, p < 0.005). Maximum response to both salbutamol and histamine and slope of concentration-response curves of both agents were significantly greater in patients with asthma than in normal subjects (p < 0.001 and p < 0.005 for maximum response and slope, respectively). The increased sensitivity of asthmatics to inhaled salbutamol suggests that they also may be more sensitive to their endogenous adrenaline, which may thus dilate and stabilize their airways. 相似文献