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   49196篇
  免费   3673篇
  国内免费   117篇
耳鼻咽喉   389篇
儿科学   2090篇
妇产科学   1463篇
基础医学   6463篇
口腔科学   488篇
临床医学   6665篇
内科学   9213篇
皮肤病学   783篇
神经病学   4848篇
特种医学   1027篇
外国民族医学   38篇
外科学   4684篇
综合类   511篇
一般理论   99篇
预防医学   7153篇
眼科学   674篇
药学   2619篇
中国医学   85篇
肿瘤学   3694篇
  2024年   76篇
  2023年   492篇
  2022年   722篇
  2021年   1531篇
  2020年   920篇
  2019年   1447篇
  2018年   1687篇
  2017年   1229篇
  2016年   1298篇
  2015年   1372篇
  2014年   1916篇
  2013年   2795篇
  2012年   3962篇
  2011年   4065篇
  2010年   2159篇
  2009年   1882篇
  2008年   3401篇
  2007年   3361篇
  2006年   3096篇
  2005年   3031篇
  2004年   2735篇
  2003年   2444篇
  2002年   2291篇
  2001年   305篇
  2000年   195篇
  1999年   312篇
  1998年   456篇
  1997年   342篇
  1996年   292篇
  1995年   302篇
  1994年   256篇
  1993年   226篇
  1992年   134篇
  1991年   139篇
  1990年   121篇
  1989年   101篇
  1988年   108篇
  1987年   77篇
  1986年   97篇
  1985年   104篇
  1984年   117篇
  1983年   102篇
  1982年   121篇
  1981年   158篇
  1980年   105篇
  1979年   64篇
  1978年   57篇
  1977年   60篇
  1976年   58篇
  1974年   55篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
There is no established treatment for the neurological features of the recently discovered fragile X-associated tremor/ataxia syndrome (FXTAS). Fifty-six patients with FXTAS completed a questionnaire to determine whether any medications had been effective for neurological symptoms. Of 11 subjects with definite FXTAS, 8 (70%) were on medications for their neurological symptoms, whereas most subjects with possible or probable FXTAS, 31 (70%) of 45 subjects, were not on medications. Although no therapy was uniformly effective for intention tremor, ataxia, Parkinsonism, memory loss, or anxiety, some subjects with intention tremor or Parkinsonism reported improvement with medications frequently used in other movement disorders. Overall, all 22 subjects on medications reported improvement in one or more symptoms. Lack of insight, recall bias, and cognitive impairment may have resulted in an underestimation of the beneficial effect of medical therapy. This study suggests that patients with FXTAS can derive improvement from medication treatment for some of their symptoms.  相似文献   
53.
Conjugated linoleic acid (CLA) refers to a mixture of positional and geometric dienoic isomers of linoleic acid found naturally in animal products of ruminant sources. Recent interest in CLA research stems from the well-documented anticarcinogenic, antiatherogenic, antidiabetic, and antiobesity properties of CLA in rodents. However, there has been very little published human research on CLA. This review discusses the physiologic properties of CLA and their potential implications for human health.  相似文献   
54.
OBJECTIVES: Measurement of cortical thickness and subjective assessment of cortical porosity on panoramic radiographs are methods previously reported for diagnosing osteoporosis. The aims of this study were to determine the relative efficacy of the mandibular cortical index and cortical width in detecting osteoporosis, both alone and in combination, and to determine the optimal cortical width threshold for referral for additional osteoporosis investigation. STUDY DESIGN: Six hundred seventy-one postmenopausal women 45 to 70 years of age were recruited for this study. They received dual energy x-ray absorptiometry (DXA) scans of the left hip and lumbar spine (L1 to L4), and dental panoramic radiographic examinations of the teeth and jaws. Three observers separately assessed the mandibular cortical width and porosity in the mental foramen region of the mandible. Cortical width was corrected for magnification errors. Chi-squared automatic interaction detection analysis (CHAID) software was used (SPSS AnswerTree, version 3.1, SPSS Inc., Chicago, IL). RESULTS: Chi-squared automatic interaction detection analysis showed that the cortical porosity was a poorer predictor of osteoporosis than mandibular cortical width. For the 3 observers, a mandibular cortical width of <3 mm provided diagnostic odds ratios of 6.51, 6.09, and 8.04. The test is therefore only recommended in triage screening of individuals by using radiographs made for purposes other than osteoporosis. CONCLUSION: When evaluating panoramic radiographs, only those patients with the thinnest mandibular cortices (i.e., <3 mm) should be referred for further osteoporosis investigation.  相似文献   
55.
Functional magnetic resonance imaging (fMRI) based on blood oxygen level-dependent (BOLD) contrast has become an invaluable tool in the assessment of in vivo neuronal activation. Quantification of the BOLD response is determined by the hemodynamic and metabolic changes that occur in response to brain stimulation. However, these changes may vary by changes in insulin, a hormone known to be vasoactive in some tissues. To determine if insulin has an effect on fMRI, we measured the BOLD response to a visual stimulus in five normal volunteers in which insulin was first suppressed and then brought to a high physiological concentration. In addition, we also examined the effect of insulin on activation of the visual cortex as measured by the visual-evoked potential (VEP). We found that the BOLD response measured in the presence of insulin (serum insulin=236+/-29 pmol/L) was significantly lower (P<0.001) than that measured in its absence (serum insulin=8+/-2 pmol/L). Insulin was without effect on P100 amplitude or latency acquired in the presence or absence of insulin in 28 subjects using the same stimulus as that used for the fMRI experiments. Our observations suggest that insulin may have effects on cerebral blood flow and/or metabolism that affect the BOLD signal that are independent of its effects on neuronal activation identified by event related potentials (ERP). These findings highlight the complexity that must be considered when interpreting differences in fMRI responses between groups of subjects that differ in insulin concentration and/or insulin sensitivity.  相似文献   
56.
57.
58.
We evaluated blood pressure control, quality of life, quality of care, and satisfaction of patients who were monitored by specially trained community pharmacists in a group medical practice. After participating in an intensive skill development program, pharmacists performed in an interdisciplinary team in a rural clinic. The primary objective was assessed by evaluating outcome variables at 6 months compared with baseline in 25 patients randomly assigned to a study group. A control group of 26 patients was also evaluated to determine if outcome variables remained constant from baseline to 6 months. Systolic blood pressure was reduced in the study group (151 mm Hg baseline, 140 mm Hg at 6 mo, p<0.001) and diastolic blood pressure was significantly lower at 2, 4, and 5 months compared with baseline. Ratings from a blinded peer review panel indicated significant improvement in the appropriateness of the blood pressure regimen, going from 8.7 ± 4.7 to 10.9 ± 4.5 in the study group (p<0.01), but they did not change in the control group. Several quality of life scores improved significantly in the study group after 6 months (p<0.05). These included physical functioning (61.6 vs 70.7), physical role limitations (56.8 vs 72.8), and bodily pain (60.0 vs 71.7) at baseline and 6 months, respectively. There were no significant changes in the control group. Patient satisfaction scores were consistently higher in the study group at the end of the study. Our results indicate that when community pharmacists in a clinic setting are trained and included as members of the primary care team, significant improvements in blood pressure control, quality of life, and patient satisfaction can be achieved.  相似文献   
59.
60.
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