全文获取类型
收费全文 | 98217篇 |
免费 | 6006篇 |
国内免费 | 732篇 |
专业分类
耳鼻咽喉 | 1097篇 |
儿科学 | 2946篇 |
妇产科学 | 2463篇 |
基础医学 | 13186篇 |
口腔科学 | 2181篇 |
临床医学 | 7897篇 |
内科学 | 21613篇 |
皮肤病学 | 2012篇 |
神经病学 | 9125篇 |
特种医学 | 3986篇 |
外国民族医学 | 23篇 |
外科学 | 13946篇 |
综合类 | 1659篇 |
一般理论 | 54篇 |
预防医学 | 5731篇 |
眼科学 | 1557篇 |
药学 | 7847篇 |
3篇 | |
中国医学 | 511篇 |
肿瘤学 | 7118篇 |
出版年
2023年 | 406篇 |
2022年 | 967篇 |
2021年 | 1758篇 |
2020年 | 1163篇 |
2019年 | 1655篇 |
2018年 | 2026篇 |
2017年 | 1573篇 |
2016年 | 1655篇 |
2015年 | 1925篇 |
2014年 | 2555篇 |
2013年 | 3782篇 |
2012年 | 5076篇 |
2011年 | 5343篇 |
2010年 | 3449篇 |
2009年 | 3037篇 |
2008年 | 4675篇 |
2007年 | 4920篇 |
2006年 | 4635篇 |
2005年 | 4484篇 |
2004年 | 4781篇 |
2003年 | 4605篇 |
2002年 | 4622篇 |
2001年 | 3747篇 |
2000年 | 3666篇 |
1999年 | 2979篇 |
1998年 | 1170篇 |
1997年 | 933篇 |
1996年 | 855篇 |
1995年 | 811篇 |
1994年 | 722篇 |
1993年 | 696篇 |
1992年 | 1784篇 |
1991年 | 1764篇 |
1990年 | 1505篇 |
1989年 | 1444篇 |
1988年 | 1335篇 |
1987年 | 1196篇 |
1986年 | 1182篇 |
1985年 | 1049篇 |
1984年 | 774篇 |
1983年 | 704篇 |
1982年 | 459篇 |
1981年 | 392篇 |
1979年 | 571篇 |
1978年 | 422篇 |
1975年 | 430篇 |
1974年 | 486篇 |
1973年 | 462篇 |
1972年 | 424篇 |
1971年 | 393篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Arnold Criel Gregor Verhoef Robert Vlietinck Cristina Mecucci Johan Billiet Lucienne Michaux Peter Meeus ries Louwagie Angeline Van Orshoven Achiel Van Hoof Mark Boogaerts Herman Van den Berghe & Chris De Wolf-Peeters 《British journal of haematology》1997,97(2):383-391
We analysed a group of 390 patients, diagnosed with chronic lymphocytic leukaemia (CLL). Cases were subclassified as morphologically typical and atypical CLL according to the criteria of the FAB proposal. Typical CLL cases were mostly diagnosed at a low-risk stage (Binet A/Rai 0), required no immediate treatment and expected a long survival; atypical CLL cases mostly presented at a more advanced risk stage (Binet B/Rai I–II), usually required immediate treatment and their survival was shorter. Moreover, clinical staging was of prognostic significance in typical but not in atypical cases. In typical CLL, del(11q) was the most common chromosomal abnormality (21%) whereas in atypical CLL trisomy 12 was found in about 65% of the cases documented with an abnormal karyotype. Although chromosomal abnormalities were associated with a poor survival in typical CLL, they are of no prognostic significance in atypical CLL. Based on these data, we conclude that subtyping CLL by morphology enables the identification of two groups of cases, each characterized by a specific clinical presentation, different cytogenetic abnormalities and prognostic parameters. We speculate that these two groups may represent two related, but different, diseases with different prognostic parameters and a different survival. 相似文献
92.
93.
IgA antiendomysium antibodies in human umbilical cord sections as a screening test in relatives of patients with celiac disease 总被引:1,自引:0,他引:1
M. Bagnasco P. Montagna A. De Alessandri E. Castellano G. P. Pesce R. Gatti 《Allergy》1997,52(10):1017-1021
We performed the serum IgA antiendomysium antibody (EmA) assay by indirect immunofluorescence on human umbilical cord sections in 86 subjects with celiac disease, in 187 first-degree relatives of such patients, and in a control group of 68 unrelated subjects, to investigate the suitability of the method in the screening of populations at risk of gluten sensitivity. Conventional EmA assay using monkey esophagus sections was performed in parallel experiments. The results obtained showed a perfpect correlation between the two methods. All the celiac patients and none of the controls were positive for EmA. EmA positivity was also observed in 11 apparently healthy relatives: intestinal biopsy performed in five of them invariably showed villous atrophy and increase of mucosal lymphocytes. Taking into account the low cost of EmA assay on human umbilical cord, especially when compared to monkey esophagus sections, the method is probably suitable and effective in identifying latent, asymptomatic gluten sensitivity in at-risk populations. 相似文献
94.
95.
Nakamura Hajime; De Rosa Stephen; Roederer Mario; Anderson Michael T.; Dubs J. Gregson; Yodoi Junji; Holmgren Arne; Herzenberg Leonard A.; Herzenberg Leonore A. 《International immunology》1996,8(4):603-611
Thioredoxin (Trx), a ubiquitous protein intimately involvedin redox and protein disulfide reductions, has been shown tobe released from cells and to have cytokine-like activities.In addition, Trx has been implicated in the redox regulationof immunological responses and shown to be deficient in tissuesfrom AIDS patients. In studies presented here, plasma Trx levelswere measured by ELISA in plasma samples from HIV-infected individuals(n = 136) and HIV-negative controls (n = 47). To account forthe release of Trx into plasma due to hemolysis, the Trx measurementswere corrected according to the level of hemoglobin in the plasmasample. Data presented show that, in contrast to tissue Trxlevels, corrected plasma Trx levels are significantly higherin HIV-infected individuals than in controls (P < 0.0001).Furthermore, {small tilde}25% of the HIV-infected individualsstudied have plasma Trx levels greater than the highest levelfound in controls (37 ng/ml). Detailed multiparameter FACS analysisof peripheral blood mononuclear cells (PBMC) from the infectedindividuals demonstrates that those with higher plasma Trx levels(37 ng/ml or greater) tend to have lower overall CD4 counts.In addition, increases in plasma Trx levels correlate with decreasesin monochlorobimane staining (indicative of lower intracellularglutathione levels in PBMC) and with changes in surface antigenexpression (CD62L, CD38 and CD20) that occur in the later stagesof HIV infection. These correlations suggest that elevationof plasma Trx levels may be an important component of advancedHIV disease, perhaps related to the oxidative stress that oftenoccurs at this stage. 相似文献
96.
C Altomare A Carotti S Cellamare G Leogrande D De Vito 《Il Farmaco; edizione pratica》1990,45(11):1229-1236
A simple and efficient method is described for the direct determination of Isoniazide (INH) and Pyrazinamide (PZAm) in human plasma, based on reversed-phase HPLC. A number of other antitubercular drugs such as p-Aminosalycylic acid (PAS), Streptomycin (STM) and Ethambutol (ETH) and the major metabolites of the two investigated drugs, namely N-Monoacetylisoniazide (AcINH) and Pyrazinoic acid (PZAc), were shown not to interfere with the assay method. A potential application of the method to routine clinical monitoring of antitubercular drugs is discussed. 相似文献
97.
98.
Obstructive and restrictive ventilatory impairment in polyvinylchloride fabrication workers 总被引:1,自引:0,他引:1
P Ernst L De Guire B Armstrong G Thériault 《American journal of industrial medicine》1988,14(3):273-279
Responses to a standardized respiratory symptom questionnaire, spirometry, and cross-shift decreases in lung function between 70 current employees of a polyvinylchloride (PVC) fabrication plant and a control group consisting of 48 men employed in a vegetable packing plant were compared. FEV1/FVC was significantly lower in the PVC workers. Cross-shift drops in Vmax75 of 15% or more were also more prevalent in the exposed group (p = .01). When examining the association between months of work within the exposed workforce and spirometric indices of airway obstruction, no relationship could be demonstrated. However, an inverse dose-response relationship was seen between level of FVC and duration of employment, suggesting a restrictive impairment. While the specific exposures have not been identified, it appears that employment in PVC fabrication may be associated with both obstructive and restrictive ventilatory effects. 相似文献
99.
肥胖患者胰升糖素水平变化及其对空腹血糖的影响 总被引:1,自引:0,他引:1
目的 探讨肥胖患者胰升糖素的变化特点及其对血糖的影响。方法 将 82例患者根据体重指数分为 3组 :A组 (BMI <2 4,n =2 3 )、B组 (2 4≤BMI <2 7,n =2 7)、C组 (BMI≥ 2 7,n =3 2 ) ,分别测定胰升糖素、胰岛素、空腹血糖 ,采用单因素方差分析法与Spearman等级相关性分析法进行分析。结果 3组胰升糖素分别为 (15 6.3± 5 8.6)、(186.7± 67.5 )、(2 2 2 .2± 88.4)ng·L-1,C组与A组比较有显著性差异 (P <0 .0 1) ;3组胰岛素分别为 (15 .4± 4.7)mIU·L-1、(2 0 .6± 9.6)mIU·L-1、(2 2 .3± 10 .6)mIU·L-1,B组、C组与A组比较差异有显著意义 (P <0 .0 5、P <0 .0 1) ;B、C两组胰升糖素与空腹血糖呈正相关。结论 肥胖患者胰岛素、胰升糖素一致性增高 ,胰升糖素的增高是空腹血糖增高的重要因素。 相似文献
100.
P. Peeters J. Sennesael H. De Raeve M. De Waele D. Verbeelen 《Transplant international》1997,10(6):471-474
Lymphoma in immunocompromised transplant patients is a feared cause of morbidity and mortality. Superimposed on the lymphoma
and the transplantation immunosuppression is a rare condition: hemophagocytic syndrome (HS). HS is characterized by fever,
hepatosplenomegaly and lymphadenopathy, skin rashes, jaundice, coagulopathy, and phagocytosis of blood elements with pancytopenia.
Here we describe a rare but fatal case of a kidney transplant patient who developed T-cell lymphoma and HS, without evidence
of EBV replication. A short review of the diagnosis, treatment, and prognosis of HS is given.
Received: 4 March 1997 Received after revision: 6 June 1997 Accepted: 30 June 1997 相似文献