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   1487篇
  免费   99篇
  国内免费   7篇
耳鼻咽喉   4篇
儿科学   65篇
妇产科学   26篇
基础医学   138篇
口腔科学   30篇
临床医学   211篇
内科学   379篇
皮肤病学   57篇
神经病学   54篇
特种医学   253篇
外科学   208篇
综合类   29篇
预防医学   37篇
眼科学   8篇
药学   53篇
中国医学   5篇
肿瘤学   36篇
  2021年   13篇
  2019年   9篇
  2018年   26篇
  2017年   12篇
  2016年   24篇
  2015年   26篇
  2014年   30篇
  2013年   38篇
  2012年   27篇
  2011年   39篇
  2010年   44篇
  2009年   67篇
  2008年   44篇
  2007年   26篇
  2006年   30篇
  2005年   26篇
  2004年   19篇
  2003年   30篇
  2002年   32篇
  2001年   36篇
  2000年   30篇
  1999年   33篇
  1998年   60篇
  1997年   60篇
  1996年   72篇
  1995年   50篇
  1994年   46篇
  1993年   51篇
  1992年   32篇
  1991年   15篇
  1990年   32篇
  1989年   47篇
  1988年   43篇
  1987年   39篇
  1986年   46篇
  1985年   37篇
  1984年   28篇
  1983年   23篇
  1982年   26篇
  1981年   17篇
  1980年   12篇
  1979年   15篇
  1978年   11篇
  1977年   15篇
  1976年   20篇
  1975年   27篇
  1974年   18篇
  1972年   10篇
  1969年   10篇
  1968年   9篇
排序方式: 共有1593条查询结果,搜索用时 0 毫秒
71.
It has been suggested that proliferation of enterobacteriaceae and/or anaerobes in the duodenum of some children with acute diarrhoea determines whether the episode becomes persistent. A review of published studies and the comparison of cultures of duodenal aspirates from Peruvian children with acute and persistent diarrhoea and diarrhoea-free children did not support this hypothesis. Although many children had enterobacteriaceae and/or anaerobes cultured there was no correlation with clinical and nutritional outcome. Age, nutritional status, the environment and the aetiology of the episode were determinants of the duodenal microflora independent of diarrhoea. Culture of the duodenal aspirates did not increase the yield of enteropathogens which were isolated more frequently from stools than from the duodenum. Despite the presence of a single strain or serotype of enterobacteriaceae suggesting that these bacteria were colonizing the duodenum, we were unable to demonstrate any adherence mechanisms in the majority of them. Two often bacteria with no other evidence of virulence caused diarrhoea in the RITARD rabbit model.  相似文献   
72.
It is important that a routine search be done roentgenographically for intramural intestinal gas. Several different patterns may be present, but unfortunately, classification of the findings is not helpful in predicting either the cause, or the presence, of gangrene. Also, the clinical circumstances in which intramural intestinal gas is discovered are important--if seen in a patient with acute pain in the abdomen, panmural gangrene is nearly always present and early operation desirable. However, if first discovered in the early postoperative period, a more selective approach is possible. Although many of the patients with intramural intestinal gas died, approximately one-quarter will survive. Hopefully, more timely recognition of intramural intestinal gas will allow earlier surgical intervention in some patients with ischemia of the intestine.  相似文献   
73.
BACKGROUND: Minimally invasive surgical techniques have become routinely applied to the evaluation and treatment of patients with isolated diaphragmatic injuries due to penetrating trauma. The objective of the study was to compare the healing of diaphragm injuries as determined by macroscopic inspection, histologic appearance, and tensile strength following repair by open suturing, laparoscopic suturing, and laparoscopic stapling techniques in an animal model. METHODS: Using a pig model, three injuries were created and repaired in each hemidiaphragm of five animals, for a total of 30 lacerations. These injuries were repaired using single-layer open repair, single-layer laparoscopic repair, or laparoscopic stapling. After a 6-week healing period the animals were sacrificed. The gross integrity, histologic appearance using H+E and trichrome satins, and tensile strength of each repair were assessed. RESULTS: All injuries were grossly intact without dehiscence or herniation. Histologic examination revealed no difference in the collagen deposition between the three groups. The tensile strengths of each type of repair were similar. CONCLUSION: Laparoscopic techniques used to repair diaphragmatic injuries allow for adequate healing equivalent to open sutured repairs. Simple approximation of the peritoneum with laparoscopic staples allows full-thickness healing of these injuries.  相似文献   
74.
Very-low-birthweight (VLBW) neonates are more prone to complications and death than term infants are. In a 15-year period, 19 neonates with VLBW were operated on for necrotizing enterocolitis (NEC). Indications for operation were pneumoperitoneum in 12 and deterioration of general condition in 7. Bowel resection and intestinal diversion was performed in 12, a lateral enterostomy at the site of perforation was created in 5, and 2 neonates with necrosis of the whole bowel underwent an exploratory laparotomy without any further surgical treatment. Surgical complications were found in one-third of the patients. The mortality rate was significantly higher when the ileum was affected. The survival rate was 68%. Prior to 1984 the survival rate was 37% (3/8); subsequently, it has improved to 91% (10/11) as a result of improved intensive therapy.  相似文献   
75.
76.
The injection of a γ-emitting tracer in backward-facing step flow was modelled. Flow and concentration fields were calculated by CFD and detector responses by a Monte-Carlo code. The objective was to show the influence of the radiotracer energy on the detector response, so as to interpret better data from radiotracer experiments. The radiotracer selection is important in obtaining reliable results, each specific case requiring careful analysis of the experimental data. However, more work is still required to achieve the prescribed goal aimed at.  相似文献   
77.
We sampled, using the brain dialysis technique, interstitial fluid adenosine from the frontal cortex of newborn piglets subjected to hemorrhagic hypotension while measuring sagittal sinus blood flow, cerebrovascular resistance (CVR), and cerebral O2 delivery. In group 1 (n = 8), MABP was reduced in successive steps from 76 to 30 mm Hg with decrements of approximately 10 mm Hg. At 60 mm Hg, CVR decreased by 19% (p less than 0.001), but sagittal sinus blood flow and interstitial fluid adenosine remained unchanged. At 50 mm Hg, both sagittal sinus blood flow and CVR decreased by 19% (p less than 0.001) and interstitial fluid adenosine rose 4.7-fold (p less than 0.05). At 40 and 30 mm Hg, sagittal sinus blood flow decreased further but CVR remained steady, whereas interstitial fluid adenosine rose 10- and 16-fold, respectively. In group 2 (n = 7), an abrupt reduction of MABP from 80 to 47 mm Hg produced no change in sagittal sinus blood flow and a 29% decrease in CVR (p less than 0.01). Interstitial fluid adenosine increased twofold (p less than 0.01). In group 3 (n = 7), an abrupt reduction of MABP from 79 to 40 mm Hg decreased sagittal sinus blood flow and CVR by 24 and 30%, respectively (p less than 0.01). Interstitial fluid adenosine rose threefold (p less than 0.01). In groups 1, 2, and 3, the increases in interstitial fluid adenosine accompanied decreases in cerebral O2 delivery. In group 4 (n = 7), artificial CSF with a PO2 of 152 mm Hg was perfused through the brain dialysis cannula during graded hypotension.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
78.
Duodenal "diverticulization" for duodenal and pancreatic injury   总被引:20,自引:0,他引:20  
Duodenal “diverticulization” has been achieved in thirty-four cases of combined duodenal and pancreatic or severe duodenal or pancreatic injury. The operation consists of gastric antrectomy with end to side gastrojejunostomy, tube duodenostomy, closure of the duodenal perforation, and drainage. The combined mortality for these thirty-four cases and a previously reported series of sixteen cases is 16 per cent. Regional complications that developed after duodenal diverticulization were generally well tolerated and not lethal. All duodenal and pancreatic fistulas closed spontaneously.  相似文献   
79.
80.
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