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   1073280篇
  免费   73218篇
  国内免费   1361篇
耳鼻咽喉   15015篇
儿科学   34606篇
妇产科学   28623篇
基础医学   153387篇
口腔科学   29553篇
临床医学   94907篇
内科学   203623篇
皮肤病学   24393篇
神经病学   81436篇
特种医学   42961篇
外国民族医学   201篇
外科学   163088篇
综合类   21702篇
现状与发展   1篇
一般理论   263篇
预防医学   74599篇
眼科学   24535篇
药学   86113篇
  7篇
中国医学   2805篇
肿瘤学   66041篇
  2019年   7755篇
  2018年   11293篇
  2017年   8906篇
  2016年   10094篇
  2015年   11260篇
  2014年   15267篇
  2013年   22197篇
  2012年   30546篇
  2011年   32290篇
  2010年   18950篇
  2009年   17813篇
  2008年   29944篇
  2007年   32065篇
  2006年   32700篇
  2005年   31028篇
  2004年   29721篇
  2003年   28549篇
  2002年   27524篇
  2001年   60020篇
  2000年   61475篇
  1999年   50927篇
  1998年   12443篇
  1997年   11000篇
  1996年   11014篇
  1995年   10320篇
  1994年   9341篇
  1993年   8857篇
  1992年   37788篇
  1991年   36273篇
  1990年   35744篇
  1989年   34285篇
  1988年   30864篇
  1987年   29986篇
  1986年   28214篇
  1985年   26448篇
  1984年   19185篇
  1983年   16113篇
  1982年   8822篇
  1979年   17029篇
  1978年   11404篇
  1977年   10229篇
  1976年   8837篇
  1975年   10068篇
  1974年   11651篇
  1973年   11273篇
  1972年   10754篇
  1971年   10092篇
  1970年   9252篇
  1969年   8938篇
  1968年   7917篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
181.
182.
183.
This study qualitatively examined factors that influenced contraceptive choices in a sample of young, HIV-infected women. Individual qualitative interviews were conducted among 30 vertically and horizontally HIV-infected women (= 26 African American) from the ages of 14 to 24 years (Mean age = 20.9 years). We recruited sample groups with the following characteristics: (a) current contraceptive/condom use with ≥1 child (= 11); (b) current contraceptive/condom use with no children (= 12); and (c) no current contraceptive/condom use with no children (= 7). A semi-structured interview guide was used to ask participants about factors influencing past and current contraceptive choices. Individual interviews were digitally recorded and transcribed verbatim; analyses to identify core themes were informed by the Grounded Theoretical approach. Young, HIV-infected women did not identify their HIV serostatus or disease-related concerns as influential in their contraceptive decisions. However, they reported that recommendations from health-care providers and input from family and friends influenced their contraceptive choices. They also considered a particular method’s advantages (e.g., menstrual cycle improvements) and disadvantages (e.g., increased pill burden) when selecting a method. Findings suggested that HIV-infected young women’s contraceptive decisions were influenced by factors other than those related to their infection.  相似文献   
184.
185.
International Journal of Legal Medicine - Sex identification is a primary step in forensic analysis of skeletal remains. The accuracy of sex estimation methods greatly depends on the sexual...  相似文献   
186.
187.
188.
Introduction: This study investigated variables associated with subjective decline in executive function among Veterans of Operations Enduring Freedom, Iraqi Freedom, and New Dawn (OEF/OIF/OND) following a history of blast-related mild traumatic brain injury (mTBI).

Method: Fifty-six male U.S. Veterans (MAge = 35.3 ± 8.8 years) with a history of blast-related mTBI (6.6 ± 3.2 years post injury) completed a battery of self-report questionnaires and neuropsychological measures. Participants rated current and retrospectively estimated pre-mTBI executive function difficulties on the Frontal Systems Behavior Scale (FrSBe). A difference score (post- minus pre-mTBI ratings) was the dependent variable (?FrSBe). Linear regression models examined variables predicting ?FrSBe, including: pre-injury characteristics (education, premorbid intelligence), injury-related characteristics (number of blast exposures, losses of consciousness), post-injury clinical symptoms (PTSD Checklist–Military version; Pittsburgh Sleep Quality Index), and post-injury neuropsychological performances on executive function measures (Trail Making Test Part B; Controlled Oral Word Association Test; Auditory Consonant Trigrams; Wisconsin Card Sorting Test).

Results: While 11% of participants had a clinically elevated pre-injury FrSBe total score, 82% had a clinically elevated post-injury FrSBe total score. Only self-reported PTSD symptom severity independently predicted perceived change in executive function.

Conclusions: Many OEF/OIF/OND Veterans with a history of blast-related mTBI experience subjective decline in executive function following injury. Perceived executive function decline was associated with higher PTSD symptom severity, aligning with previous research associating PTSD with cognitive complaints. Results did not support a correspondence between perceived cognitive change and neuropsychological performances.  相似文献   
189.
Osteoporosis is a condition in which the bones are thinner and more liable to fracture. It is commoner in women and in people over 50. It cannot be cured so the focus is on prevention, which means identifying and addressing risk factors such as obesity, low vitamin D, chronic inflammation and prolonged steroid medication. Chronic urticaria (hives, CU) is an inflammatory condition, so one might expect it to be linked with osteoporosis, but that has never been investigated. If people with CU are indeed more likely to develop osteoporosis, they could be advised about preventative measures. To study this, doctors from Israel identified 11,944 patients diagnosed with CU in a large medical database covering 4.5 million people. A potential difficulty was that people with CU are more likely to be female, obese and to have been treated with systemic steroids, all of which also increase the risk of osteoporosis. Therefore for each CU patient they studied 5 age- and sex-matched control patients (people of the same age and sex but without CU) and their analyses took into account other known risk factors for osteoporosis. During a 16 year period 8.7% of the patients with CU were diagnosed with osteoporosis compared with 6.8% of the controls. They concluded that CU is a small but significant additional risk factor for osteoporosis. An accompanying editorial cautions against basing conclusions on routine health records which may not have all the information required. Nonetheless, doctors treating chronic urticaria might bear in mind the risk of osteoporosis in their patients, and counsel accordingly.  相似文献   
190.
ABSTRACT

Take-Away Points:

1. Geriatric palliative care requires integrating the disciplines of hospital medicine and palliative care in pursuit of delivering comprehensive, whole-person care to aging patients with serious illnesses.

2. Older adults have unique palliative care needs compared to the general population, different prevalence and intensity of symptoms, more frequent neuropsychiatric challenges, increased social needs, distinct spiritual, religious, and cultural considerations, and complex medicolegal and ethical issues.

3. Hospital-based palliative care interdisciplinary teams can take many forms and provide high-quality, goal-concordant care to older adults and their families.  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