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   630篇
  免费   20篇
  国内免费   14篇
耳鼻咽喉   2篇
儿科学   8篇
妇产科学   52篇
基础医学   54篇
口腔科学   1篇
临床医学   21篇
内科学   192篇
皮肤病学   6篇
神经病学   24篇
特种医学   27篇
外科学   112篇
一般理论   1篇
预防医学   82篇
眼科学   2篇
药学   37篇
中国医学   1篇
肿瘤学   42篇
  2023年   6篇
  2022年   12篇
  2021年   12篇
  2020年   4篇
  2019年   14篇
  2018年   10篇
  2017年   10篇
  2016年   11篇
  2015年   14篇
  2014年   12篇
  2013年   40篇
  2012年   39篇
  2011年   33篇
  2010年   15篇
  2009年   12篇
  2008年   31篇
  2007年   23篇
  2006年   35篇
  2005年   39篇
  2004年   39篇
  2003年   32篇
  2002年   34篇
  2001年   20篇
  2000年   19篇
  1999年   18篇
  1998年   8篇
  1997年   3篇
  1996年   10篇
  1995年   8篇
  1994年   4篇
  1993年   5篇
  1992年   8篇
  1991年   8篇
  1990年   8篇
  1989年   7篇
  1988年   6篇
  1987年   8篇
  1986年   3篇
  1985年   5篇
  1984年   2篇
  1983年   3篇
  1982年   2篇
  1979年   2篇
  1974年   2篇
  1973年   2篇
  1971年   4篇
  1970年   2篇
  1968年   7篇
  1967年   3篇
  1966年   4篇
排序方式: 共有664条查询结果,搜索用时 31 毫秒
1.
BACKGROUND: High-dose chemotherapy followed by autologous blood stem cell transplantation induces remission of plasma cell dyscrasia in patients with AL amyloidosis. The impact of this treatment on the glomerular amyloid mass is still unknown. METHODS: In the present study, the quantity of the renal amyloid mass before and more than 3 years after high-dose melphalan treatment and autologous blood stem cell transplantation was assessed in two patients. At the time of the second renal biopsy, both patients were in complete remission without detectable serum and urinary monoclonal IgA-lambda and a normal percentage of plasma cells in the bone marrow. RESULTS: In both patients with biopsy-proven AL amyloidosis, urinary protein excretion decreased from 7 g/24 h to <2 g/24 h more than 3 years after autologous blood stem cell transplantation. In contrast, glomerular amyloid deposits persisted, as shown in the second biopsy. CONCLUSION: Despite complete remission of the plasma cell dyscrasia and improvement of glomerular permeability, the amount of glomerular amyloid mass did not regress.  相似文献   
2.
The risk of hemorrhage in infants with severe coagulopathies unresponsive to fresh frozen plasma (FFP) infusions may preclude therapeutic invasive interventional procedures. We describe the successful use of recombinant factor VIIa (rFVIIa) in two such infants, the first with cirrhosis requiring paracentesis and the second with necrotizing enterocolitis requiring laparotomy. This report reviews the current concepts on the mechanism of action of the drug rFVIIa and considers its expanded use in infants unresponsive to FFP replacement.  相似文献   
3.
Somatostatin Receptor Localization of Pancreatic Endocrine Tumors   总被引:2,自引:0,他引:2  
n = 39) than conventional imaging studies (MRI, n = 25; CT, n = 13); 23 of 24 patients had positive octreotide scintigraphy, 17 of 24 had positive MRI-scans, and 12 of 24 patients had positive CT scans. It was concluded that 111 In-octreotide scintigraphy combined with conventional imaging improves the preoperative localization of presumably tumorous lesions in patients with gastroenterohepatic endocrine tumors.  相似文献   
4.
Diclofenac and its derivative nitrofenac were compared to test their anti-inflammatory efficacy and gastrointestinal toxicity in rats.A similar good anti-inflammatory activity of the two drugs was observed in carrageenan oedema and a marked gastrointestinal toxicity was induced by diclofenac, while nitrofenac failed to produce gastric damage even with very high doses (50 and 100 mg/kg).The lack of the gastric ulcers in rats treated with nitrofenac could be due to the absorption of the drug as an inactive inhibitor of PG synthesis and/or to the fact that probably nitric oxide is release in the intestine and plays an important protective role in maintaining the tissue integrity.  相似文献   
5.
OBJECTIVE: Elevation of blood pressure and heart rate increase the risk of cardiovascular disease. Administration of estrogens does not affect heart rate but may decrease 24 h blood pressure. In this study, we tested the effect of the estro-progestogenic compound tibolone. METHODS: Thirty healthy, post-menopausal women were randomized to receive placebo (n = 15) or tibolone, at the commonly prescribed dose of 2.5 mg per day (n = 15). Before and after 6 months of treatment, in each woman blood pressure and heart rate were monitored every 30 min for 41 h by an ambulatory device. Valuable readings were those collected from 8:00 a.m. of the second day to 8:00 a.m. of third day. Analyses were performed of 24 h, day-time (7:00 a.m.-11:00 p.m.) and night-time (11:00 p.m.-7:00 a.m.) values. Day to night difference was also calculated. Results: Placebo did not modify 24h, day-time, and night-time blood pressure or heart rate values. Day-night differences were also not affected by placebo. Similarly to placebo, tibolone administration did not modify any of the blood pressure parameters taken into consideration. By contrast, a significant decline of 24 h heart rate (73.2 +/- 2.3 beats/min versus 69.3 +/- 1.7 beats/min; P < 0.0008) was observed. The effect was significant both at day (76.6 +/- 2.4 beats/min versus 72.1 +/- 1.9 beats/min; P < 0.0001) and night (65.8 +/ 2.6 beats/min versus 62.4 +/- 1.9 beats/min; P < 0.05). Day-night blood pressure and heart rate differences were not affected by tibolone. CONCLUSIONS: In post-menopausal women, administration of tibolone does not influence 24 h blood pressure but reduces heart rate.  相似文献   
6.
Summary This study was performed in order to elucidate some of the problems of incidence, morphology and natural history concerned with Stage A prostatic cancer or prostatic microcarcinoma (PMC).The prostates of 100 patients, treated by subtotal prostatectomy for benign prostatic hyperplasia (BPH), were studied by comparing both routine and step-section techniques. The incidence of PMC was 41% by the former and 86% by the latter technique. Assessment of the size of PMC, as measured by the sum of the two main diameters, resulted in three groups: A1, A2, A3. The last of these may represent a frankly malignant condition, judged by size and the histological appearance. Radical prostatectomy is strongly suggested as appropriate therapy for this group.Supported in part by a Grant from the Ministry of Education (art. 286 T.U., 1977/78)  相似文献   
7.
Kava-Kava administration reduces anxiety in perimenopausal women   总被引:1,自引:0,他引:1  
OBJECTIVE: Disturbances of mood, such as anxiety and depression, increase in the perimenopausal period. Hormone replacement therapy or neuroactive drugs represent useful treatments for these disturbances but may be contraindicated or not accepted. Herein it was investigated the efficacy of Kava-Kava, an extract of Piper Methysticum, on mood of perimenopausal women. DESIGN: A 3-months randomized prospective open study investigating in perimenopausal women modifications induced by calcium supplementation (control; n=34), calcium plus Kava-Kava at the dose of 100 mg/day (n=15) or calcium plus Kava-Kava at the dose 200 mg/day (n=19). Anxiety was evaluated by the State Trait Anxiety Inventory (STAI); depression by the Zung's scale (SDS), and climacteric symptoms by the Greene's scale. Evaluations were performed at baseline and after 1 and 3 months. RESULTS: In the control group during the 3 months, anxiety, depression and climacteric symptoms tended to decline, but not significantly. During Kava-Kava anxiety declined (P<0.001) at 1 (-3.8+/-1.03) and 3 (-5.03+/-1.2) months, depression declined at 3 months (-5.03+/-1.4; P<0.002) and climacteric score declined (P<0.0006) at 1 (-2.87+/-1.5) and 3 (-5.38+/-1.3) months. Only the decline of anxiety induced by Kava-Kava was significantly greater than that spontaneously occurring in controls (P<0.009). CONCLUSIONS: The present data indicate that, in perimenopausal women, administration of Kava-Kava induces an improvement of mood, particularly of anxiety.  相似文献   
8.
Patients affected by diabetes mellitus are reported to have an increased incidence of gallbladder abnormalities. The pathophysiologic mechanisms for this phenomenon are unclear. In the present study ultrasonography was used to determine gallbladder emptying in response to a meal or separate cephalic or hormonal stimulation in 21 diabetic patients and 10 healthy subjects. Gallbladder emptying and refilling after a meal were similar in diabetic patients and healthy subjects. When diabetics were divided according to the presence or absence of cardiac autonomic neuropathy (AN), a significant reduction of gallbladder emptying in response to cephalic stimulation was found in diabetics with AN (P<0.01 in comparison with diabetics without AN or healthy subjects). A dose-response curve of gallbladder emptying in response cerulein, a cholecystokinin analog, at concentrations of 0.25, 1, and 4 g/kg/min was evaluated. No differences of gallbladder emptying were found in the three groups of subjects, indicating that gallbladder sensitivity to hormonal stimulation is not changed in diabetic patients with or without AN. Diabetic patients with AN have a significant reduction of gastric acid output and pancreatic polypeptide (PP) secretion in response to cephalic stimulation (P<0.05 in comparison with diabetic patients without AN or healthy subjects). Cerulein-induced PP secretion was similar in all three groups of subjects (P>0.05). This study indicates that in diabetic patients with AN, gallbladder emptying as well as gastric acid and PP secretions induced by neural stimulation are markedly reduced in comparison to diabetics without AN.  相似文献   
9.
Nitric oxide (NO) is a short-lived diffusable molecule now believed to participate in multiple physiologic functions in the CNS including neurotransmission and the maintenance of vascular tone. Previously, we reported that cell lines obtained by retroviral immortalization of tissue macrophages (M?;) could be induced to synthesize nitrite (NO), a stable end product of the NO synthetic pathway. We have further characterized the induction and activity of this pathway in a panel of seven microglial clones derived from primary embryonic mouse brain cultures. Like M?;, these clones were found to release high levels of NO-2 in response to recombinant interferon-γ (rIFN-γ) as a priming signal together with either bacterial lipopolysaccharide (LPS) or exogenous recombinant tumor necrosis factor-α (rTNF-α). As previously demonstrated for M?;, phagocytosis of zymosan particles during induction of enzyme activity enhanced subsequent NO production, which is of interest in light of the postulated phagocytic role of microglia within the CNS. Biochemical characterization of enzyme activity in intact microglial clones and in isolated cytosolic fractions indicates that the microglial NO synthase present in these murine cell clones represents the M?;-like isotype. These findings suggest that microglial cells could represent a major source of NO within the CNS.  相似文献   
10.
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