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   13296篇
  免费   980篇
  国内免费   52篇
耳鼻咽喉   93篇
儿科学   515篇
妇产科学   227篇
基础医学   1519篇
口腔科学   251篇
临床医学   1250篇
内科学   2988篇
皮肤病学   221篇
神经病学   1681篇
特种医学   456篇
外国民族医学   1篇
外科学   2000篇
综合类   190篇
一般理论   5篇
预防医学   1067篇
眼科学   202篇
药学   815篇
中国医学   9篇
肿瘤学   838篇
  2021年   150篇
  2020年   122篇
  2019年   179篇
  2018年   189篇
  2017年   186篇
  2016年   191篇
  2015年   208篇
  2014年   308篇
  2013年   413篇
  2012年   611篇
  2011年   652篇
  2010年   367篇
  2009年   336篇
  2008年   614篇
  2007年   619篇
  2006年   646篇
  2005年   560篇
  2004年   494篇
  2003年   524篇
  2002年   468篇
  2001年   433篇
  2000年   483篇
  1999年   382篇
  1998年   166篇
  1997年   188篇
  1996年   184篇
  1995年   157篇
  1994年   126篇
  1993年   120篇
  1992年   272篇
  1991年   300篇
  1990年   269篇
  1989年   271篇
  1988年   226篇
  1987年   206篇
  1986年   220篇
  1985年   201篇
  1984年   146篇
  1983年   129篇
  1982年   93篇
  1981年   94篇
  1979年   139篇
  1978年   122篇
  1977年   107篇
  1976年   102篇
  1975年   123篇
  1974年   114篇
  1973年   103篇
  1972年   91篇
  1970年   89篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
21.
22.
23.
Brinerdin (Sandoz), a combination of a diuretic (clopamide 5 mg), a vasodilator (dihydro-ergocristine 0.5 mg) and reserpine (0.1 mg) (CDR) was compared with methyldopa (MD) plus hydrochlorothiazide (HCT) for antihypertensive effect, adverse reactions, compliance and patient preference in an open cross-over trial. Eighteen patients completed both arms of the trial and 5 patients who completed the CDR arm were withdrawn while on the MD arm because of adverse effects in 4 and poor control in 1. On HCT 50 mg daily the mean baseline systolic blood pressure was 163.9 +/- 16.3 mmHg and the diastolic blood pressure was 105.9 +/- 6.7 mmHg. On CDR these were reduced to systolic blood pressure 140.3 +/- 15.1 mmHg and diastolic blood pressure 87.8 +/- 9.3 mmHg. On MD + HCT the systolic blood pressure was reduced to 138.5 +/- 16.9 mmHg and the diastolic blood pressure to 88.9 +/- 10.3 mmHg. The differences between the two treatment periods in systolic blood pressure (1.8 mmHg; 95% confidence interval (CI) - 4.1 + 7.7 mmHg) and diastolic blood pressure (1.1 mmHg; 95% CI - 4.6 + 2.4 mmHg) were not significant with P values of 0.6 and 0.7 respectively. Compliance was 98.2% for CDR and 94.7% for MD + HCT (P = 0.02). Unusual sleepiness occurred more frequently in the MD arm (P less than 0.01). Thirteen patients chose to continue on CDR, 2 on MD + HCT and 3 had no preference (P = 0.005). CDR is similar in antihypertensive effect to MD + HCT but is better tolerated with fewer withdrawals, fewer adverse effects, better compliance and has more patients electing to continue taking it.  相似文献   
24.
Thirty-three patients with primary gastrointestinal lymphoma (GIL) followed at Ankara University Medical School have been evaluated. The most frequent locations of the disease are the small intestine (48.4%) and the stomach (39.3%). The intermediate and high grade lymphomas constitute 84.8% of the cases. The mean age of the patients with small intestinal lymphoma is 28.7 years and 47.1 years for those with gastric lymphoma. The patients treated with surgery and chemotherapy (S+CT) have a longer survival than those treated with chemotherapy (CT) alone. In conclusion: 1) Small intestinal lymphoma occurs more frequently than gastric lymphoma in our study. 2) The median age of the Turkish patients with primary GIL is approximately 10 years less than those in the Western countries. 3) The therapeutic results of S+CT are superior to those of CT in the early stages of the disease.  相似文献   
25.
Anastomotic leaks are still among the most common severe postoperative complications and account for the majority of postoperative deaths after esophagectomy and gastrectomy. Every disturbance of the normal postoperative course should trigger surgeons to consider an underlying anastomotic leak and initiate a specific diagnostic workup. This includes direct endoscopic inspection of the anastomosis to evaluate the vitality of the anastomosed organs and the size of the leak. Adequate external drainage of the leak and prevention of further contamination are the primary therapeutic goals. Selection of therapy is guided by the available modalities for sufficiently draining the leak and avoiding sepsis. The spectrum of therapeutic options ranges from simple opening of the neck incision in cervical esophageal anastomoses, interventional placement of drains, to endoscopic intervention with closure of the fistula or placement of stents, and reoperation with exclusion, diversion, or discontinuity resection.  相似文献   
26.
Abstract: The results of an intensive treatment program for patients 16–60 yr of age with de novo acute myeloid leukemia are presented. The patients were given conventional induction treatment with daunorubicin and cytarabine. Patients not entering complete remission (CR) after 1 course of daunorubicin/cytarabine were given 1 course of amsacrine/etoposide/cytarabine. Those entering complete remission received 3 consolidation courses using mitoxantrone, etoposide, amsacrine and cytarabine. One hundred and eighteen patients were enrolled. Complete remission was attained after 1–2 courses in 90 patients (76%). Another 6 patients reached CR after 3–4 induction courses for a total CR rate of 81%. If feasible, patients were offered either allogeneic or unpurged autologous bone marrow transplantation. Twenty-four patients underwent allogeneic bone marrow transplantation; 15 in first remission, 8 in second remission, 1 in early relapse. Thirty patients below 56 yr of age underwent autologous bone marrow transplantation in first remission. The overall probability of survival at 4 yr was 34%, and for patients below 40 yr of age 50%. Leukemia-free survival was 35% for the whole cohort of patients; 52% for patients below 40 yr of age. Patients undergoing allogeneic or autologous bone marrow transplantation in first remission had an overall survival of 86% and 47%, respectively, while the probability of leukemia-free survival in these groups was 87% vs. 40% at 4 yr. The CR rate and long-term results of this intensive treatment program compare favorably with other recent studies using intensive consolidation with allogeneic or autologous bone marrow transplantation or high dose cytarabine.  相似文献   
27.
Disordered vergence control in dyslexic children.   总被引:4,自引:1,他引:3       下载免费PDF全文
By means of a synoptophore vergence eye movements were recorded in dyslexic and normal children while they were attempting to track small targets moving in simulated depth. Of the dyslexic children 64% were unable to make proper vergence movements when macular sized fusion targets (2 1/2 degrees) were employed, but their vergence control was better for larger (7 degrees) targets. The normal readers and the remaining dyslexics showed normal vergence responses for both large and small moving fusion stimuli. The results suggest that many dyslexics suffer a disorder of visuomotor control and perception for stimuli falling on the macula; this may explain their characteristic visual problems when reading. Hence recording vergence eye movement responses to small moving fusion stimuli may be useful in the investigation and treatment of children with reading difficulties.  相似文献   
28.
BACKGROUND. Temafloxacin is a new broad-spectrum arylfluoroquinolone antimicrobial with an extended serum half-life. METHODS. In this large, multicenter, double-blind clinical trial, 404 women with acute, uncomplicated urinary tract infections (UTI) were randomized to receive temafloxacin 400 mg once daily for 3 days, or ciprofloxacin 250 mg twice daily for 7 days. Clinical and microbiologic evaluations were repeated at 4 to 5 days after initiation of treatment, at the end of therapy, and at 5 to 9 days posttreatment. One hundred fifteen patients who received temafloxacin and 105 patients who received ciprofloxacin met the eligibility criteria for efficacy evaluation. The predominant urinary pathogens were Escherichia coli, Proteus mirabilis, and coagulase-negative staphylococci. No pretherapy isolate was resistant to either study drug. RESULTS. Bacteriologic eradication was observed in 112 (97%) of 115 women treated with temafloxacin and 101 (96%) of 105 women treated with ciprofloxacin. Clinical cure rates at 5 to 9 days posttreatment were 90% (the remaining 10% improved) with temafloxacin and 95% (the remaining 5% improved) with ciprofloxacin. Adverse effects associated with treatment occurred in 24 (12%) women who received temafloxacin and 31 (15%) women who received ciprofloxacin. Headache (2% with temafloxacin and 2% with ciprofloxacin), nausea (3% with temafloxacin and 6% with ciprofloxacin), and somnolence (4% with temafloxacin and 3% with ciprofloxacin) were reported most often. Only three and five patients who were treated with temafloxacin and ciprofloxacin, respectively, discontinued treatment because of adverse effects. CONCLUSIONS. In this study, a 3-day treatment regimen using a single daily 400-mg dose of temafloxacin was found to be as effective as a 7-day course of ciprofloxacin in women with acute uncomplicated UTI.  相似文献   
29.
Lowering of the elevated plasma FFA concentration in 18- 24-h fasted rats with nicotinic acid (NA) caused complete ablation of subsequent glucose-stimulated insulin secretion (GSIS). Although the effect of NA was reversed when the fasting level of total FFA was maintained by coinfusion of soybean oil or lard oil (plus heparin), the more saturated animal fat proved to be far more potent in enhancing GSIS. We therefore examined the influence of individual fatty acids on insulin secretion in the perfused rat pancreas. When present in the perfusion fluid at 0.5 mM (in the context of 1% albumin), the fold stimulation of insulin release from the fasted pancreas in response to 12.5 mM glucose was as follows: octanoate (C8:0), 3.4; linoleate (C18:2 cis/cis), 5.3; oleate (C18:1 cis), 9.4; palmitate (C16:0), 16. 2; and stearate (C18:0), 21.0. The equivalent value for palmitoleate (C16:1 cis) was 3.1. A cis--> trans switch of the double bond in the C16:1 and C18:1 fatty acids had only a modest, if any, impact on their potency. A similar profile emerged with regard to basal insulin secretion (3 mM glucose). When a subset of these fatty acids was tested in pancreases from fed animals, the same rank order of effectiveness at both basal and stimulatory levels of glucose was seen. The findings reaffirm the essentiality of an elevated plasma FFA concentration for GSIS in the fasted rat. They also show, however, that the insulinotropic effect of individual fatty acids spans a remarkably broad range, increasing and decreasing dramatically with chain length and degree of unsaturation, respectively. Thus, for any given level of glucose, insulin secretion will be influenced greatly not only by the combined concentration of all circulating (unbound) FFA, but also by the makeup of this FFA pool. Both factors will likely be important considerations in understanding the complex interplay between the nature of dietary fat and whole body insulin, glucose, and lipid dynamics.  相似文献   
30.
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