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   638篇
  免费   33篇
  国内免费   26篇
耳鼻咽喉   7篇
儿科学   51篇
妇产科学   9篇
基础医学   53篇
口腔科学   29篇
临床医学   69篇
内科学   160篇
皮肤病学   6篇
神经病学   11篇
特种医学   117篇
外科学   48篇
综合类   7篇
预防医学   15篇
眼科学   5篇
药学   73篇
肿瘤学   37篇
  2022年   3篇
  2021年   7篇
  2020年   3篇
  2019年   3篇
  2018年   6篇
  2016年   5篇
  2015年   8篇
  2014年   9篇
  2013年   15篇
  2012年   8篇
  2011年   6篇
  2010年   10篇
  2009年   16篇
  2008年   14篇
  2007年   27篇
  2006年   7篇
  2005年   14篇
  2004年   8篇
  2003年   18篇
  2002年   8篇
  2001年   13篇
  2000年   8篇
  1999年   8篇
  1998年   39篇
  1997年   44篇
  1996年   53篇
  1995年   41篇
  1994年   33篇
  1993年   31篇
  1992年   11篇
  1991年   17篇
  1990年   12篇
  1989年   22篇
  1988年   22篇
  1987年   17篇
  1986年   13篇
  1985年   17篇
  1984年   14篇
  1983年   8篇
  1982年   7篇
  1981年   7篇
  1980年   6篇
  1979年   10篇
  1978年   8篇
  1977年   7篇
  1976年   7篇
  1975年   10篇
  1974年   3篇
  1969年   2篇
  1968年   4篇
排序方式: 共有697条查询结果,搜索用时 15 毫秒
1.
2.
de Vries Reilingh  TS  van Geldere  D  Langenhorst  BLAM  de Jong  D  van der Wilt  GJ  van Goor  H  Bleichrodt  RP 《Hernia》2004,8(1):56-59
Polypropylene mesh is widely used for the reconstruction of incisional hernias that cannot be closed primarily. Several techniques have been advocated to implant the mesh. The objective of this study was to evaluate, retrospectively, early and late results of three different techniques, onlay, inlay, and underlay. The records of 53 consecutive patients with a large midline incisional hernia — 25 women and 28 men, mean age 60.4 (range 28–94) — were reviewed. Polypropylene mesh was implanted using the onlay technique in 13 patients, inlay in 23 patients, and underlay in 17 patients. Either the greater omentum or a polyglactin mesh was interponated between the mesh and the viscera. The records of these 53 patients were reviewed with respect to: size and cause of the hernia, pre- and postoperative mortality and morbidity, with special attention to wound complications. Patients were invited to attend the outpatient clinic at least 12 months after implantation of the mesh for physical examination of the abdominal wall. Postoperative complications occurred in 14 (26.4%) patients. The onlay technique had significantly more complications, as compared to both other techniques. Reherniation occurred in 15 (28.3%) patients. The reherniation rate of the inlay technique was significantly higher than after the underlay technique (44% vs 12%, P=0.03) and tended to be higher than the onlay technique (44% vs 23%, P=0.22). Repair of large midline incisional hernias with the use of a polypropylene mesh carries a high risk of complications and has a high reherniation rate. The underlay technique seems to be the better technique.  相似文献   
3.
4.
Fifty patients with refractory acute lymphoblastic leukemia underwent allogeneic bone marrow transplantation after conditioning with high-dose cytosine arabinoside and fractionated total body irradiation. Twenty-nine received intravenous immunoglobulin (i.v.Ig) infusion, primarily to prevent cytomegalovirus infection, and 21 did not. The two groups were biologically comparable. Seven (24.5%) of the i.v.Ig-treated and 14 (66.7%) of the non-i.v.Ig-treated patients developed systemic viral, fungal or bacterial infections and/or interstitial pneumonitis (p less than 0.005), which were fatal in three and 12 cases respectively (p less than 0.001). Currently, 23 (79.3%) of the 29 i.v.Ig-treated and eight (38.1%) of the 21 non-i.v.Ig-treated patients are alive and well (p less than 0.01). We conclude that prophylactic i.v.Ig infusions may reduce the frequency of all forms of serious infection in patients with acute lymphoblastic leukemia undergoing allogeneic marrow transplantation, and thereby improve their survival expectation.  相似文献   
5.
Olson  MA; Becker  GJ 《Radiology》1986,159(1):25-26
An anomalous pulmonary vein draining into the subdiaphragmatic inferior vena cava was initially demonstrated on computed tomographic (CT) scans. The diagnosis of scimitar syndrome was confirmed with digital subtraction angiography. In retrospect, the anomalous vein and dextroposition of the heart were shown on chest radiographs.  相似文献   
6.
One-hundred and six male children aged 6-23 months with a history of acute watery diarrhoea of less than 72 h duration were randomized to receive either folic acid in a dose of 5 mg at 8-h intervals or placebo for 5 d. There were 54 children in the folic acid group and 52 in the placebo group. The admission characteristics were comparable between the two groups. No significant differences were observed in the intake of oral rehydration solution or stool output between the groups. The mean ± SD of total stool output (g kg−1) was 532 ± 476 vs 479 ± 354 and the duration (h) of diarrhoea was 108 ± 68 vs 103 ± 53 in the folic acid vs placebo group, respectively. The findings, therefore, should have a positive influence on preventing the inappropriate use of folic acid in acute diarrhoea.  相似文献   
7.
Gramzinski  RA; Broze  GJ Jr; Carson  SD 《Blood》1989,73(4):983-989
Studies of proteins that inhibit tissue factor activity have generally been conducted using either an extracted tissue homogenate ("thromboplastin") or tissue factor protein reconstituted into phospholipid vesicles rather than with tissue factor expressed in cell membranes (its physiological environment). In the present study, a human fibroblast cell strain was used to evaluate the effects of lipoprotein associated coagulation inhibitor (LACI), placental anticoagulant protein (PAP), and apolipoprotein A-II (apo A-II) on human tissue factor in cell membranes. LACI was tested from 7.8 to 500 pmol/L on fibroblasts cultured at cell densities ranging from 3,500 to 9,925 cells/well, and caused a progressive inhibition of tissue factor activity. PAP was tested from 3.9 nmol/L to 1 mumol/L at cell densities ranging from 4,500 to 15,400 cells/well and caused up to 83% inhibition of tissue factor activity. Inhibition by these proteins appeared to be influenced by cell density as well as whether the cells were intact or disrupted. Apo A-II, up to 1 mumol/L, did not inhibit the tissue factor activity of intact or disrupted fibroblasts at any cell density examined even though it did inhibit the activity of tissue factor in phospholipid vesicles. Of these inhibitors of tissue factor-dependent activation of factor X, LACI was the most effective in suppressing the generation of factor Xa activity. The effects obtained with apo A-II are clearly dependent on the nature of the tissue factor preparation with which it is tested. The disparity between the inhibitory effect of apo A-II on the activity of tissue factor reconstituted into lipid vesicles and the absence of effect on the activity of tissue factor remaining in cell membranes serves to reemphasize the necessity of reexamining results obtained with model systems using as nearly physiological reagents as possible.  相似文献   
8.
A 63-year-old man with iron loss anaemia and hypercalcaemia was found to have a renal cell carcinoma. Despite the iron-deficient blood and bone marrow picture, the serum ferritin concentration was markedly raised. This was mainly due to a “basic isoferritin”. The serum parathormone concentration was normal. The serum ferritin and calcium concentrations returned to normal after the tumour was removed. We propose that the renal cell carcinoma cells in this patient secreted the basic isoferritin as well as humoral factor(s) responsible for hypercalcaemia.  相似文献   
9.
Glomeruli from 6 cases of sickle cell disease (SS) with the nephrotic syndrome (NS) were compared histologically and quantitatively with glomeruli from 9 cases of SS, 10 cases of sickle cell trait (SCT), 4 cases of other hemoglobinopathies, all without NS, and normal controls. Five of 6 patients with SS and NS had extensive reduplication of their glomerular basement membranes and mild mesangial proliferation. Similar but milder lesions occurred in SS without NS but not in SCT or controls. Incidental renal disease occurred in 1 patient with SS and NS. Nephrotic syndrome was probably secondary to effects of sickle cell disease. Glomeruli in SS were significantly larger (>70%) than in SCT and controls. Mean total glomerular area per unit area of cortex in SS with normal BUN significantly exceeded that of SCT, which, in turn, was significantly greater than that of controls. Mechanisms for the histologic lesions and hypertrophy of the glomeruli were suggested.  相似文献   
10.
We have used the “allogeneic effect” as a model system for investigating the effects of augmented thymus-derived lymphocyte function on secondary antibody responses of primed inbred guinea pigs. A transient graft-versus-host reaction was induced by infusing nonimmune strain 13 lymphoid cells into strain 2 guinea pigs which had been primed with dinitrophenylated (DNP) ovalbumin. Six days later the recipients were challenged with the priming antigen intradermally. Four days after boosting with antigen, sera from these “allogeneic” guinea pigs had significantly higher affinity for ε-DNP-L -lysine than sera from “control” guinea pigs which were primed, but had not received allogeneic lymphoid cells. Spleen cells taken from “allogeneic” guinea pigs three to five days after boosting were shown to have both higher numbers of plaque-forming cells and a predominance of high avidity antibody-producing cells in comparison to spleen cells from “control” guinea pigs. Thus, increased donor thymus-derived lymphocyte function brought about by the transient graft-versus-host reaction causes an enlargement of the host antibody-producing cell pool and preferentially expands the subpopulation of cells producing high affinity antibody. The effects of this preferential expansion are reflected in the sera of “allogeneic” guinea pigs as higher affinity antibody in comparison to serum antibody of “control” guinea pigs.  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