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   1744篇
  免费   91篇
  国内免费   21篇
耳鼻咽喉   1篇
儿科学   23篇
妇产科学   19篇
基础医学   220篇
口腔科学   24篇
临床医学   125篇
内科学   285篇
皮肤病学   54篇
神经病学   220篇
特种医学   97篇
外科学   451篇
综合类   7篇
预防医学   69篇
眼科学   50篇
药学   86篇
中国医学   2篇
肿瘤学   123篇
  2022年   26篇
  2021年   24篇
  2020年   18篇
  2019年   21篇
  2018年   23篇
  2017年   31篇
  2016年   24篇
  2015年   32篇
  2014年   49篇
  2013年   59篇
  2012年   73篇
  2011年   79篇
  2010年   32篇
  2009年   47篇
  2008年   81篇
  2007年   64篇
  2006年   65篇
  2005年   82篇
  2004年   64篇
  2003年   102篇
  2002年   88篇
  2001年   76篇
  2000年   78篇
  1999年   63篇
  1998年   25篇
  1997年   19篇
  1996年   16篇
  1995年   12篇
  1994年   11篇
  1992年   27篇
  1991年   34篇
  1990年   31篇
  1989年   38篇
  1988年   30篇
  1987年   37篇
  1986年   27篇
  1985年   18篇
  1984年   13篇
  1983年   30篇
  1982年   9篇
  1981年   16篇
  1980年   10篇
  1979年   15篇
  1978年   18篇
  1977年   12篇
  1976年   8篇
  1975年   19篇
  1974年   9篇
  1973年   14篇
  1968年   8篇
排序方式: 共有1856条查询结果,搜索用时 15 毫秒
1.
Tacrolimus combined with mycophenolate mofetil (MMF) is an effective regimen in kidney transplantation. This study compared the efficacy of combining tacrolimus and two different dosages of sirolimus with an established tacrolimus-MMF regimen. Each day in addition to tacrolimus, 325 patients received 2 mg sirolimus (TAC-SRL2 mg), 325 patients received 0.5 mg sirolimus (TAC-SRL0.5 mg) and 327 patients 1 g MMF (TAC-MMF). The initial tacrolimus dose was 0.2 mg/kg/day. Sirolimus patients received loading doses of 6 or 1.5 mg, and daily doses of 2 or 0.5 mg thereafter. Steroid administration was identical for all groups. The incidence of biopsy-proven acute rejection was lower in the TAC-SRL2 mg group (15.7%) compared with the TAC-SRL0.5 mg (25.2%, p = 0.003) and the TAC-MMF groups (22.3%, p = 0.036). Six-month graft survival was 91.0% (TAC-SRL2 mg), 92.6% (TAC-SRL0.5 mg) and 92.4% (TAC-MMF); the respective values for patient survival were 98.1%, 97.8% and 97.9%. Thirty-four patients (10.5%), 19 patients (5.8%) and 16 patients (4.9%) in the TAC-SRL2 mg, TAC-SRL0.5 mg and TAC-MMF groups, respectively, discontinued the study because of adverse events. Hyperlipemia was reported more often in the TAC-SRL2 mg group (24.0%) compared with 19.4% (TAC-SRL0.5 mg) and 11.0% (TAC-MMF; p < 0.05). Combining 2 mg sirolimus/day with tacrolimus results in lower rates of acute rejection, but a higher incidence of adverse events.  相似文献   
2.
3.
4.
Background: Residual neuromuscular blockade remains a problem even after short surgical procedures. The train-of-four (TOF) ratio at the adductor pollicis required to avoid residual paralysis is now considered to be at least 0.9. The incidence of residual paralysis using this new threshold is not known, especially after a single intubating dose of intermediate-duration nondepolarizing relaxant. Therefore, the aim of the study was to determine the incidence of residual paralysis in the postanesthesia care unit after a single intubating dose of twice the ED95 of a nondepolarizing muscle relaxant with an intermediate duration of action.

Methods: Five hundred twenty-six patients were enrolled. They received a single dose of vecuronium, rocuronium, or atracurium to facilitate tracheal intubation and received no more relaxant thereafter. Neuromuscular blockade was not reversed at the end of the procedure. On arrival in the postanesthesia care unit, the TOF ratio was measured at the adductor pollicis, using acceleromyography. Head lift, tongue depressor test, and manual assessment of TOF and DBS fade were also performed. The time delay between the injection of muscle relaxant and quantitative measurement of neuromuscular blockade was calculated from computerized anesthetic records.

Results: The TOF ratios less than 0.7 and 0.9 were observed in 16% and 45% of the patients, respectively. Two hundred thirty-nine patients were tested 2 h or more after the administration of the muscle relaxant. Ten percent of these patients had a TOF ratio less than 0.7, and 37% had a TOF ratio less than 0.9. Clinical tests (head lift and tongue depressor) and manual assessment of fade showed a poor sensitivity (11-14%) to detect residual blockade (TOF < 0.9).  相似文献   

5.
T lymphocyte function was analyzed in patients hemodialyzed with 'high-flux' polysulfone membranes, which have been reported to improve the patients' overall clinical condition and well-being. For comparison purposes, patients treated by the use of 'low-flux' cuprophane membranes were also studied. Peripheral blood white cell counts, numbers of lymphocytes as well as the numbers of T cells and their CD4 and CD8 subsets were within normal range in both patient groups. The absolute number of B cells was slightly decreased in cuprophane-membrane- but not polysulfone-membrane-treated patients. The proliferative response of T lymphocytes after stimulation with optimal concentration of phytohemagglutinin (PHA) was normal in patients treated with 'high-flux' membrane dialysis but significantly reduced in those treated with cuprophane membranes. The generation of interleukin-2 (IL-2) receptor on T lymphocytes after PHA stimulation was normal in the polysulfone-membrane-treated group and slightly impaired in the cuprophane-membrane-dialyzed patients. Production of both IL-2 and interleukin-1, as well as the natural killer cell activity, in patients treated by 'high-flux' membrane dialysis were also comparable to controls. The levels of serum beta 2-microglobulin were significantly elevated in patients-maintained on 'high-flux' dialysis membranes but did not reach the levels seen in patients dialyzed by cuprophane membranes. The beta 2-microglobulin at levels seen in patients on cuprophane dialysis had no effects on activation and proliferation of control lymphocytes in vitro. These results suggest that impaired functional responses of T lymphocytes seen in end-stage disease patients on prolonged hemodialysis with cuprophane membranes are not seen in similar patients hemodialyzed with polysulfone membranes.  相似文献   
6.
Serum growth hormone (GH), insulin-like growth factor (IGF-I), insulin and C-peptide were measured by RIA in fetal blood collected in utero by umbilical cord puncture performed for a variety of indications. Eighty-four fetuses were aged 19-25 weeks and 14 were 26-37 weeks. IGF-I values were lower than the sensitivity of the method. The range for GH was 3-197 micrograms/l (GH-micrograms/l x 2 = mU/l), for insulin 14.3-117 pmol/l, for C-peptide 66.2-827.5 pmol/l. GH significantly increased from week 19 to 25; insulin and C-peptide levels increased from week 19 to 37. GH levels at 19-25 weeks were significantly higher in fetuses with femoral length less than the 5th compared with those with femoral length greater than the 95th centile for that age. GH and insulin levels did not correlate with weight at birth or with maternal hormone levels. These data provide evidence for a presence in living fetuses, from the 19th week, of high levels of GH and of insulin levels not very different from those in adults but these hormones do not seem to be directly responsible for fetal growth.  相似文献   
7.
We report the results of the vaccinations against hepatitis B carried out with vaccine H-B-VAX of the commercial firm (Merck Sharp and Dohme), on 102 U.S.L. 32 hospital workers in Portomaggiore (Ferrara, Italy). The vaccine rendered 92% of the subjects inoculated immune and the incidence of secondary effects was low.  相似文献   
8.
9.
The authors present a retrospective study of 66 infected cases in their series of limb salvage surgery performed from January 84 to August 92. Special emphasis was given to the alternative techniques of treatment in infection. In 85% of the cases healing was achieved, however removal of the implant and amputation are still frequent occurrences. Time to recovery is very demanding.  相似文献   
10.
P F Piguet  C Vesin  J Guo  Y Donati    C Barazzone 《Immunology》1998,95(1):111-116
We explored the thrombocytopaenia elicited by the i.v. injection of mouse recombinant tumour necrosis factor (TNF) in mice. Injection of 10 micrograms of TNF led to a thrombocytopaenia (evident after 0.5 hr) which was caused by decreased platelet survival, as seen by the injection of labelled platelets. TNF-induced thrombocytopaenia was not prevented by heparin, nor by depletion of either fibrinogen or C'. TNF-induced thrombocytopaenia was markedly attenuated in mice treated with reserpine, an agent that depletes monoamines from mast cells and other cells, and in the mast-cell-deficient WWv mice. In vitro, TNF elicited a modest release of monoamine from peritoneal mast cells and from a mast cell line. When mice are injected with 3H-serotonin (3H-5HT) before TNF, TNF injection increased the plasma 3H-5HT content 1 hr later, modifications absent in reserpine pretreated or mast-cell-deficient mice. 3H-5HT content of the small intestine was markedly depleted in TNF-injected mice, suggesting that this organ is the source of the plasma 3H-5HT. Drop in body temperature and mortality induced by TNF were also attenuated in mast-cell-deficient, and in reserpine pretreated mice. These results indicate that TNF can induce a release of monoamines from mast cells, mainly from those of the small intestine, a process that contributes to TNF-induced thrombocytopaenia and mortality.  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