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   2762篇
  免费   170篇
  国内免费   12篇
耳鼻咽喉   52篇
儿科学   68篇
妇产科学   36篇
基础医学   303篇
口腔科学   194篇
临床医学   209篇
内科学   650篇
皮肤病学   54篇
神经病学   272篇
特种医学   54篇
外科学   410篇
综合类   11篇
一般理论   1篇
预防医学   220篇
眼科学   27篇
药学   153篇
中国医学   18篇
肿瘤学   212篇
  2023年   24篇
  2022年   49篇
  2021年   112篇
  2020年   64篇
  2019年   82篇
  2018年   124篇
  2017年   76篇
  2016年   68篇
  2015年   85篇
  2014年   145篇
  2013年   173篇
  2012年   224篇
  2011年   264篇
  2010年   132篇
  2009年   113篇
  2008年   170篇
  2007年   167篇
  2006年   153篇
  2005年   166篇
  2004年   138篇
  2003年   135篇
  2002年   93篇
  2001年   23篇
  2000年   20篇
  1999年   26篇
  1998年   20篇
  1997年   11篇
  1996年   12篇
  1995年   8篇
  1994年   6篇
  1993年   9篇
  1992年   7篇
  1991年   7篇
  1990年   3篇
  1989年   3篇
  1987年   2篇
  1986年   3篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1980年   1篇
  1979年   1篇
  1976年   2篇
  1975年   3篇
  1974年   3篇
  1970年   3篇
  1969年   2篇
  1968年   2篇
  1966年   1篇
  1934年   1篇
排序方式: 共有2944条查询结果,搜索用时 15 毫秒
21.
22.
The general aim of this study is to create a cohort of asthma patients with varying grades of severity in order to gain greater insight into the mechanisms underlying the genesis and course of this disease.The specific objectives focus on various studies, including imaging, lung function, inflammation, and bronchial hyperresponsiveness, to determine the relevant events that characterize the asthma population, the long-term parameters that can determine changes in the severity of patients, and the treatments that influence disease progression. The study will also seek to identify the causes of exacerbations and how this affects the course of the disease.Patients will be contacted via the outpatient clinics of the 8 participating institutions under the auspices of the Spanish Respiratory Diseases Networking System (CIBER). In the inclusion visit, a standardized clinical history will be obtained, a clinical examination, including blood pressure, body mass index, complete respiratory function tests, and FENO will be performed, and the Asthma Control Test (ACT), Morisky-Green test, Asthma Quality of Life Questionnaire (Mini AQLQ), the Sino-Nasal Outcome Test 22 (SNOT-22), and the Hospital Anxiety and Depression scale (HADS) will be administered. A specific electronic database has been designed for data collection. Exhaled breath condensate, urine and blood samples will also be collected. Non-specific bronchial hyperresponsiveness testing with methacholine will be performed and an induced sputum sample will be collected at the beginning of the study and every 24 months. A skin prick test for airborne allergens and a chest CT will be performed at the beginning of the study and repeated every 5 years.  相似文献   
23.
24.
25.
Tissue-selective estrogen complex (TSEC) is projected as a progestogen-free option for the treatment of estrogen deficiency symptoms in postmenopausal, non-hysterectomized women. TSEC combines the benefits of estrogen with a selective estrogen receptor modulator (SERM), in this case bazedoxifene acetate (BZA), which has an antagonistic effect on the endometrium, thus avoiding the use of progestins. The authorized TSEC combination (conjugated estrogens [CE] 0.45?mg/BZA 20?mg) for the alleviation of vasomotor symptoms has been demonstrated in randomized clinical trials compared with placebo or menopausal hormone therapy (MHT). In addition, TSEC has shown improvements in quality of life and vaginal atrophy. In respect to MHT using progestins, the benefits of TSEC are found mainly in the bleeding pattern, amenorrhea rate, and reduction in mammary repercussion (i.e., breast tenderness and radiological density). The objective of this guide will be to analyze the efficacy and safety of TSEC consisting of CE/BZA in postmenopausal women.  相似文献   
26.
27.
ABSTRACT

Reactive Attachment Disorder (RAD) is presumed to be a consequence of social neglect and deprivation of the kind particularly associated with institutional care. Despite its clinical relevance there is a lack of assessment tools for RAD based on the direct observation of child–caregiver interaction.

Here we describe the development and validation of such a tool for use with preschool children, the Rating of Inhibited Attachment Disordered Behavior (RInAB). The RInAB is composed of 17 ratings grouped in three subscales assessing (1) Attachment, (2) Exploratory, and (3) Socioemotional behavior.

Participants were 134 institutionalized preschool children (M = 54.84 months; SD = 10.83; 60% boys) and their caregivers.

Adequate reliability was found for RInAB subscales and total score. Confirmatory factor analyses documented the three aforementioned RInAB subscales. Correlational analyses documented: (i) construct validity via positive and significant associations with caregiver sensitivity and quality of child–caregiver relationship; (ii) convergence validity via association evidence with some emotionally/withdrawn inhibited items of the Disturbed Attachment Interview (DAI), as well as, with Child Behavior Checklist (CBCL)’s somatic complaints and withdraw syndrome scales; and (iii) discriminant validity via nonsignificant or negative associations with DAI-indiscriminate subscale, Rating of Infant and Stranger Engagement (RISE) and CBCL-externalizing problems. Discussion highlights the contributions complementary roles of RInAB for a comprehensive assessment of child RAD-related functioning.  相似文献   
28.
This study was designed to test the reproducibility of a food frequency questionnaire used in a population‐based case‐control study on diet and pancreatic cancer. Repeat questionnaires covering the same time period were obtained using 63 male and female population controls, 35–79 years of age. For selected food items included in the case‐control study, the attenuation of the odds ratios due to random error was estimated. Using 54 male and female population controls, 35–79 years of age, we conducted a second study to examine the agreement between original and repeat interviews when the time interval between interview and the period of interest was constant.

In the first study, the median correlation coefficient was 0.72 for foods (ranging from 0.36 and 0.59 for subgroups of vegetables to 0.96 for alcoholic beverages) and 0.77 for nutrients (ranging from 0.62 for β‐carotene to 0.85 for energy and 0.91 for ethanol). In the second study, the median correlation coefficient was 0.68 for foods (ranging from 0.28 for eggs to 0.87 for alcoholic beverages) and 0.75 for nutrients (ranging from 0.48 for β‐carotene to 0.76 for energy).

We conclude that for most items the agreement between original and repeat estimates was moderate (r> 0.50) to high (r > 0.70). Moderate agreement was found for 28 of 33 food items (85%) and for all 21 nutrient items (100%) and high agreement for 19 of 33 of food items (56%) and 15 of 21 nutrient items (71 %). In the second study, agreement was somewhat lower but closely paralleled the results of the first study. On average, random error presumably attenuated most of the observed diet‐cancer relationships only moderately; i.e., an observed odds ratio of 1.5 and a correlation coefficient of 0. 70 yield an unattenuated odds ratio of 2.1.  相似文献   
29.
ABSTRACT: Central giant cell lesions are benign intraosseous proliferative lesions that have considerable local aggressiveness. Nonsurgical treatment methods, such as intralesional corticosteroid injections, systemic calcitonin and interferon have been reported. Recently, bisphosphonates have been used to treat central giant cell lesions. A case of a 36-year-old male with a central giant cell lesion crossing the mandibular midline was treated with intralesional corticosteroids combined with alendronate sodium for the control of systemic bone resorption. The steroid injections and the use of bisphosphonates were stopped after seven months when further needle penetration into the lesion was not possible due to new bone formation. After two years, the bony architecture was near normal, and only minimal radiolucency was present around the root apices of the involved teeth. The patient was followed up for four years, and panoramic radiography showed areas of new bone formation. Thus far, neither recurrence nor side effects of the medication have been detected.  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