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   456篇
  免费   8篇
  国内免费   12篇
耳鼻咽喉   8篇
儿科学   17篇
妇产科学   7篇
基础医学   55篇
口腔科学   7篇
临床医学   36篇
内科学   72篇
皮肤病学   22篇
神经病学   35篇
特种医学   71篇
外科学   76篇
综合类   19篇
预防医学   10篇
眼科学   16篇
药学   12篇
中国医学   3篇
肿瘤学   10篇
  2022年   3篇
  2021年   3篇
  2019年   2篇
  2018年   11篇
  2017年   3篇
  2016年   2篇
  2015年   6篇
  2014年   8篇
  2013年   15篇
  2012年   13篇
  2011年   14篇
  2010年   12篇
  2009年   18篇
  2008年   34篇
  2007年   21篇
  2006年   20篇
  2005年   32篇
  2004年   29篇
  2003年   29篇
  2002年   35篇
  2001年   16篇
  2000年   22篇
  1999年   17篇
  1998年   13篇
  1997年   8篇
  1996年   12篇
  1995年   5篇
  1994年   4篇
  1993年   9篇
  1992年   6篇
  1989年   5篇
  1988年   3篇
  1987年   3篇
  1986年   1篇
  1985年   6篇
  1984年   3篇
  1983年   4篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1979年   3篇
  1978年   3篇
  1977年   3篇
  1976年   1篇
  1975年   2篇
  1971年   1篇
  1964年   2篇
  1963年   1篇
  1962年   1篇
  1961年   3篇
排序方式: 共有476条查询结果,搜索用时 281 毫秒
1.
Background: Among gastric restrictive operations, the procedure of choice is still controversial. The aim of this study is to compare the results of two different gastric restrictive procedures: vertical banded gastroplasty (VBG) and stoma adjustable silicone gastric banding (ASGB). Methods: Between 1991 and 1996, 51 patients were treated surgically for morbid obesity: 27 underwent VBG and 24 underwent ASGB. Preoperative body weight (BW), body mass index (BMI) and percentage of ideal body weight (% IBW) were (mean ± SD): 145.7 ± 45.3 kg; 53.9 ± 15.9 kg/m2; 249.1 ± 73.5% respectively in the VBG group. Corresponding figures for the ASBG group were 132.5 ± 22.7 kg; 46.9 ± 7.8 kg/m2 and 207.2 ± 35.0%. Results: In the VBG group, the median follow-up period was 26 months (range: 7-47). Eighteen months after the operation BW, BMI, % IBW and percentage of excess weight loss (% EWL) were 85.5 ± 26.8 kg, 31.9 ± 9.8 kg/m2, 145.4 ± 43.9% and 74 ± 1% respectively. Complications included incisional hernia (n = 1), and bowel obstruction (n = 1). One patient died of acute myocardial infarction on the third postoperative day. In the ASGB group, median follow-up time was 19.7 months (range: 18-26). At 18 months postoperation BW, BMI, % IBW and % EWL values were 86.6 ± 20.6 kg 30.6 ± 6.6 kg/m2 140.6 ± 29.3% and 64 ± 1% respectively. Gastric wall erosion occurred in two patients and the bands had to be removed. These patients underwent VBG 6 months later. Complications encountered in this group were incisional hernia (n = 1), outlet stenosis and reflux esophagitis (n = 1), reservoir leakage (n = 1) and gastrointestinal bleeding (n = 1). Two patients died of pulmonary embolism and acute gastrointestinal bleeding. Conclusions: Weight reduction was not statistically significant between the two groups. ASGB was easier to perform and less invasive than VBG.  相似文献   
2.
In animals, perfluorochemicals (PFCs) are effective ultrasound (US) contrast agents that produce hepatic, splenic, and tumor enhancement. The use of Fluosol-DA 20%, an emulsion of perfluorodecalin and perfluorotripropylamine, was studied in nine non-critically ill patients with cancer who had liver lesions. US studies without Fluosol were compared with studies obtained 24, 48, and 72 hours after Fluosol infusion. Vital signs and extensive laboratory analyses are performed before and after Fluosol infusion. Liver metastases from colonic, pancreatic, and gastric carcinoma exhibited rim or diffuse enhancement after a Fluosol dose of 1.6 g/kg or greater. Fluosol produced echogenic enhancement of the liver and spleen relative to kidney at a dose of 2.4 g/kg, allowing the detection of nonenhancing lesions. In addition, Fluosol at a dose of 1.6 g/kg or greater allowed detection of lesions not seen before contrast medium was administered in three of the seven patients studied. There was a mild increase in the level of serum glutamic oxaloacetic transaminase in two patients, one given 2.4 and the other 3.2 g/kg of Fluosol. Mild and transient allergic reactions without change in vital signs were experienced by two patients.  相似文献   
3.
Classical and anaplastic seminoma: difference in survival   总被引:1,自引:0,他引:1  
Bobba  VS; Mittal  BB; Hoover  SV; Kepka  A 《Radiology》1988,167(3):849-852
Classical and anaplastic seminoma are traditionally treated with radiation therapy and are said to have the same prognosis. A retrospective study was undertaken of 90 seminoma patients treated with radiation therapy between 1961 and 1985. The classical group consisted of 71 patients of whom 50 had stage I and 21 had stage II disease. The anaplastic group consisted of 19 patients of whom ten had stage I and nine had stage II disease. The median follow-up time was 64 months for the entire group. The 10-year relapse-free survival rate for the classical group was 94% and for the anaplastic group was 70% (P less than .05). For patients with classical stage I disease, the relapse-free actuarial survival rate was 98%; for patients with anaplastic stage I disease, it was 64% (P less than .02). For the classical stage II disease group, the relapse-free actuarial survival rate was 84% and for the anaplastic stage II disease group, 75% (P less than .70). Four patients in the classical group (6%) had relapses; of these, one patient had local recurrence of tumor, and three had distant metastases. In the anaplastic group, four patients (21%) had relapses; two patients had local recurrence of tumor, and two had distant metastases. Therefore the data suggest a difference in survival and relapse rates between classical and anaplastic seminoma.  相似文献   
4.
5.
Cytokeratins (CKs) are expressed specifically in the cytoplasm of epithelial cells. We investigated the expression of CKs immunohistochemically in basal cell carcinomas (BCCs), epidermis overlying tumour, and skin tumor-associated amyloidosis (STA). Twenty cases of BCC, 11 of which had STA were included to the study. The primary antibodies of CK1-8 (AE3), CK10 (DEK-10), CK14 (LL002), CK17 (E3), CK18 (DC10), CK19 (KS19.1), CK 5/6/18 (LP34), CK8/18 (5D3) were applied to the section immunohistochemically. In BCCs without STA, CK1-8, CK14 and CK17 antibodies were expressed by tumour tissue in all biopsy specimens. In the BCCs with STA, tumour tissue was immunoreactive always with CK1-8 and CK17 antibodies, and commonly immunoreactive with anti-CK 14 antibody. In the epidermis overlying tumour tissue, there was positive immunoreactivity with anti-CK 1-8, CK 5/6/18, CK 10 and CK 14 antibodies in all biopsy specimens. Anti-CK 17 antibody was also positive in 17 biopsy specimens. STA is immunoreactive with anti-CK1-8 in all specimens. There was mild staining with anti-CK5/6/18 and with anti-CK19 whereas no immunoreactivity with anti-CK10 and CK18 antibodies was found. In conclusion, we could not find a significant CK expression difference between BCCs with and without STA. Weak positivity and a few number of CKs were shown in STA when compared with those of BCC and epidermis overlying tumour tissue expressing the more variable CKs. Interestingly, although CKs coexpressed in pairs consisting of one basic and one acidic CK, we detected predominantly basic CKs in STA.  相似文献   
6.
7.
Supravalvular aortic stenosis (SVAS) is an inherited obstructive vascular disease that affects the aorta, carotid, coronary and pulmonary arteries. Previous molecular genetic data have led to the hypothesis that SVAS results from mutations in the elastin gene, ELN. In these studies, the disease phenotype was linked to gross DNA rearrangements (35 and 85 kb deletions and a translocation) in three SVAS families. However, gross rearrangements of ELN have not been identified in most cases of autosomal dominant SVAS. To define the spectrum of ELN mutations responsible for this disorder, we refined the genomic structure of human ELN and used this information in mutational analyses. ELN point mutations co-segregate with the disease in four familial cases and are associated with SVAS in three sporadic cases. Two of the mutations are nonsense, one is a single base pair deletion and four are splice site mutations. In one sporadic case, the mutation arose de novo. These data demonstrate that point mutations of ELN cause autosomal dominant SVAS.   相似文献   
8.
The effects of arachidonic acid (AA) on binding of [3H]naloxone to the agonist and antagonist configurations of opioid receptors were investigated in rat brain. Equilibrium binding parameters of the agonist and antagonist configurations of the receptors were evaluated from homologue displacement data in the presence or absence of AA. Addition of AA at a concentration of 0.6 mM (1.5 mumole/mg of protein) reduced by 22% and 53% the maximal number of binding sites (Bmax) respectively in the absence or presence of 100 mM NaCl. Binding affinity (KD) was not altered significantly (P < 0.05) either in the presence or absence of 100 mM NaCl and AA. We conclude that AA mediated reduction in [3H]naloxone specific binding was chiefly due to a decrease in the number of binding sites.  相似文献   
9.
The use of laparoscopic surgery in peritonitis has increased rapidly. The present study examined the effects of pneumoperitoneum on bacterial clearance. Spraque-Dawley rats were divided into six groups of seven animals. In groups 1 and 4, laparotomy with a midline incision was performed and 10(9) E. coli in a volume of 1 ml inserted into the peritoneal cavity. Groups 2, 3, 5, 6 received an identical quantity of E. coli by intraperitoneal injection. Groups 3 and 6 received carbon dioxide pneumoperitoneum at a constant pressure of 5 mmHg for 60 minutes after intraperitoneal injection of E. coli. In one hour groups; the mean bacterial counts per lung from the E. coli injection with laparotomy group was significantly higher than for the E. coli injection with pneumoperitoneum group (p < 0.05). The mean bacterial counts per kidney in the E. coli injection with laparotomy group was higher compared with the E. coli injection and E. coli injection with pneumoperitoneum groups (p < 0.0001). There was statistically significant difference in quantitative bacteraemia between the E. coli injection with laparotomy group and the E. coli injection or E. coli injection with pneumoperitoneum groups (p < 0.05). In four-hour groups; the mean bacterial counts of lungs and liver-spleen were significantly higher in the E. coli injection with laparotomy group than in the E. coli injection and E. coli injection with pneumoperitoneum groups (p < 0.05 and p < 0.001 respectively). The quantitative bacteria was significantly higher in the E. coli injection with laparotomy group than in the E. coli injection and E. coli injection with pneumoperitoneum groups (p < 0.05). This study demonstrates that pneumoperitoneum impairs the clearance of bacteria from the peritoneal cavity in an experimental model of peritonitis. However, we could not detect the deleterious effects of pneumoperitoneum compared with laparotomy.  相似文献   
10.
Summary A patient with end stage renal disease developed ischaemic skin necrosis and digital gangrene. He had diffuse arterial calcification associated with hyperparathyroidism secondary to renal failure. The patient received inappropriate cyclophosphamide therapy as he had been misdiagnosed as having an inflammatory vasculitis. This clinical picture, previously named calciphylaxis should come into the differential diagnosis of systemic vasculitis in a uraemic patient with hyperparathyroidism.  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