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   6493篇
  免费   368篇
  国内免费   22篇
耳鼻咽喉   57篇
儿科学   122篇
妇产科学   229篇
基础医学   1095篇
口腔科学   555篇
临床医学   491篇
内科学   1160篇
皮肤病学   148篇
神经病学   619篇
特种医学   187篇
外科学   983篇
综合类   42篇
一般理论   9篇
预防医学   441篇
眼科学   131篇
药学   345篇
中国医学   22篇
肿瘤学   247篇
  2023年   50篇
  2022年   108篇
  2021年   183篇
  2020年   119篇
  2019年   161篇
  2018年   204篇
  2017年   140篇
  2016年   196篇
  2015年   184篇
  2014年   251篇
  2013年   344篇
  2012年   439篇
  2011年   491篇
  2010年   275篇
  2009年   255篇
  2008年   414篇
  2007年   411篇
  2006年   321篇
  2005年   273篇
  2004年   301篇
  2003年   245篇
  2002年   211篇
  2001年   166篇
  2000年   152篇
  1999年   109篇
  1998年   35篇
  1997年   18篇
  1996年   35篇
  1994年   23篇
  1992年   54篇
  1991年   42篇
  1990年   43篇
  1989年   28篇
  1988年   47篇
  1987年   31篇
  1986年   39篇
  1985年   40篇
  1984年   21篇
  1983年   29篇
  1982年   20篇
  1981年   20篇
  1980年   17篇
  1979年   23篇
  1975年   22篇
  1974年   18篇
  1973年   16篇
  1972年   18篇
  1971年   22篇
  1970年   30篇
  1969年   18篇
排序方式: 共有6883条查询结果,搜索用时 15 毫秒
81.
82.

Background

There is a hypothesis that the growing use of mobile phones in an inappropriate posture to text and read (text neck) could be a reason for the increasing prevalence of neck pain in the past decade. Before testing if there is an association between text neck and neck pain, it is necessary to develop reliable pragmatic tools appropriate to epidemiological studies.

Objectives

The primary aim of this study was to assess the reliability of the self-perception of text neck, as well as the reliability of physiotherapists’ classification of the text neck.

Methods

The convenience sample was composed of 113 high school students between 18 and 21 years old from a cross-sectional study. As their self-perceived posture, participants had to choose in a questionnaire one of four neck postures of a person texting on a mobile phone. The physiotherapists classified lateral photographs taken with the participants texting on a mobile phone in their habitual posture as 1 (normal), 2 (acceptable), 3 (inappropriate), and 4 (excessively inappropriate).

Results

The results showed that the test–retest reliability of the self-perception was substantial (kappa?=?0.73, 95% CI 0.54 to 0.86). The reliability of the physiotherapists’ responses, according to the photographic analysis considering the three raters, was moderate (kappa?=?0.5, 95% CI 0.39 to 0.61). Seventy-six percent of the participants with appropriate posture in the photographic analysis self-reported an inappropriate posture.

Conclusion

This study showed that the self-perception of the neck posture during mobile phone texting is reliable over time and that the physiotherapists’ classification based on photographic analysis was acceptable for epidemiological studies. Participants had a tendency to report that the posture was worse than it actually was in the photographic analysis performed by the physiotherapists.  相似文献   
83.
This case report presents the effect of Cognitive Functional Therapy (CFT) in a patient with chronic non-specific neck pain. The patient believed that pain signified tissue damage, and demonstrated pain catastrophizing, hypervigilance, stress sensitivity, and movement impairment of the neck, during extension and rotation. The CFT intervention integrated a cognitive approach with manual therapy and active exercises to encourage the patient to trust her neck again. One month after the first appointment, the patient had recovered confidence, and the pain and disability had disappeared almost entirely.  相似文献   
84.
Low- and middle-income countries account for the majority of hypertension disease burden. However, little is known about the distribution of this illness within subpopulations of these countries, particularly among those who live in urban informal settlements. A cross-sectional hypertension survey was conducted in 2003 among 5649 adult residents of a slum settlement in the city of Salvador, Brazil. Hypertension was defined as either an elevated arterial systolic (≥140 mmHg) or diastolic (≥90 mmHg) blood pressure. Sex-specific multivariable models of systolic blood pressure were constructed to identify factors associated with elevated blood pressure. The prevalence of hypertension in the population 18 years and older was 21 % (1162/5649). Men had 1.2 times the risk of hypertension compared with women (95 % confidence intervals (CI), 1.05, 1.36). Increasing age and lack of any schooling, particularly for women, were also significantly associated with elevated blood pressure (p < 0.05). There was also a direct association between men who were black and an elevated blood pressure. Among those who were hypertensive, 65.5 % were aware of their condition, and only 36.3 % of those aware were actively using anti-hypertensive medications. Men were less likely to be aware of their diagnosis or to use medications (p < 0.01 for both) than women. The prevalence of hypertension in this slum community was lower than reported frequencies in the non-slum population of Brazil and Salvador, yet both disease awareness and treatment frequency were low. Further research on hypertension and other chronic non-communicable diseases in slum populations is urgently needed to guide prevention and treatment efforts in this growing population.  相似文献   
85.
86.
This report investigates the contributions of the sympathetic nerves and adrenal medulla to resting mean arterial pressure (MAP) and to emotionally conditioned MAP and heart rate (HR) responses in unrestrained spontaneously hypertensive rats (SHR) and Wistar-Kyoto normotensive control rats (WKY). Resting MAP (in mm Hg), which was higher in SHR (WKY = 120 +/- 4; SHR = 163 +/- 4; p less than 0.01), did not differ in the two strains following chemosympathectomy (WKY = 105 +/- 2; SHR = 101 +/- 2; n.s.). Adrenal medullectomy did not affect resting MAP in WKY (125 +/- 6; n.s.) but lowered it in SHR (146 +/- 5; p less than 0.05), relative to controls (see above). The conditioned pressor response (in mm Hg) in controls consisted of two peaks (I, II) in both strains, but was exaggerated in SHR (I = WKY, 13 +/- 1; SHR, 25 +/- 2; p less than 0.01; II = WKY 10 +/- 2; SHR 20 +/- 2; p less than 0.01). Chemosympathectomy suppressed (relative to controls) the first peak, but not the second, in both strains (WKY: I = 4 +/- 1, p less than 0.01; II = 12 +/- 2, n.s.; SHR: I = 6 +/- 1, p less than 0.01; II = 15 +/- 2, n.s.). Adrenal medullectomy alone had little effect on the pressor response, but when combined with chemosympathectomy both peaks were largely eliminated (WKY: I = 2 +/- I; II = 5 +/- 1; SHR: I = 1 +/- 0; II = 2 +/- 0). These data indicate that: 1) hypertension in conscious, freely behaving SHR is largely sustained by the sympathetic vasomotor nerves but that the adrenal medulla contributes to the magnitude of the elevation; 2) the early component of the exaggerated pressor response during aversive stimulation is mediated by sympathetic vasomotor excitation; and 3) the later component of the exaggerated pressor response reflects coactivation of the sympathetic vasomotor nerves and the adrenal medulla.  相似文献   
87.
Active hospital-based surveillance in the city of Salvador, Brazil, from December 1995 through October 1998, identified 221 patients with confirmed pneumococcal meningitis. Of these 221 patients, 29 (13%) had isolates with intermediate-level resistance to penicillin. Infection with these penicillin-nonsusceptible isolates was significantly associated with age of <2 years (P<.0019), previous antibiotic use (P<.0006), and coresistance to trimethoprim-sulfamethoxazole (P<.0000). Serotype 14 was the most prevalent serotype (55.2%) of penicillin-nonsusceptible isolates. Strain typing by repetitive element BOX polymerase chain reaction (PCR) analysis showed that penicillin-nonsusceptible serotype 14 isolates had closely related BOX PCR patterns, whereas penicillin-susceptible serotype 14 isolates each had distinct, unrelated patterns. Penicillin-nonsusceptible serotype 14 isolates from Salvador and other Brazilian cities had similar BOX PCR patterns. These observations indicate that in Brazil a large proportion of cases of penicillin-nonsusceptible pneumococcal meningitis appear to be caused by a closely related group of serotype 14 strains that may have disseminated to widely separate geographic areas.  相似文献   
88.
Sport Sciences for Health - To investigate the hemodynamic responses, especially HPE following different resistance exercises RE protocols in young adult subjects. Eighty-nine men...  相似文献   
89.
The frequency, nature, context, and caregivers' reactions to aggressive behavior in 213 dementia patients residing in the community was studied. Aggression was reported in 57.2% of the patients and in 10.6% of the caregivers. Predictors of patient aggression were greater frequency of behavior and memory problems, premorbid aggression, and a more troubled premorbid social relationship between patient and caregiver. Patient aggression predicted the decision to discontinue home care.  相似文献   
90.
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