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   243015篇
  免费   20633篇
  国内免费   5997篇
耳鼻咽喉   3336篇
儿科学   4634篇
妇产科学   3818篇
基础医学   20325篇
口腔科学   8271篇
临床医学   21708篇
内科学   25851篇
皮肤病学   2689篇
神经病学   13838篇
特种医学   6636篇
外国民族医学   13篇
外科学   23119篇
综合类   37526篇
现状与发展   14篇
一般理论   24篇
预防医学   30666篇
眼科学   2289篇
药学   26899篇
  346篇
中国医学   27474篇
肿瘤学   10169篇
  2024年   1048篇
  2023年   4711篇
  2022年   8931篇
  2021年   11704篇
  2020年   11119篇
  2019年   12248篇
  2018年   10979篇
  2017年   9550篇
  2016年   8657篇
  2015年   8230篇
  2014年   15746篇
  2013年   16677篇
  2012年   14230篇
  2011年   15023篇
  2010年   12286篇
  2009年   10708篇
  2008年   10072篇
  2007年   10109篇
  2006年   8760篇
  2005年   7502篇
  2004年   6250篇
  2003年   5628篇
  2002年   4507篇
  2001年   3877篇
  2000年   3435篇
  1999年   2852篇
  1998年   2419篇
  1997年   2303篇
  1996年   1905篇
  1995年   1767篇
  1994年   1626篇
  1993年   1416篇
  1992年   1356篇
  1991年   1254篇
  1990年   1089篇
  1989年   1063篇
  1988年   981篇
  1987年   883篇
  1986年   800篇
  1985年   2150篇
  1984年   2402篇
  1983年   1513篇
  1982年   1959篇
  1981年   1409篇
  1980年   1196篇
  1979年   1071篇
  1978年   882篇
  1977年   676篇
  1976年   805篇
  1975年   565篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
AIMS: The aim of this study is to compare PUMA curves with different pathologic conditions causing bladder dysfunction in 158 men and 83 women. METHODS: PUMA results in terms of bladder outlet obstruction and detrusor contractility were compared in 92 men with benign prostatic hypertrophy (BPH) and p(ves) congruent with p(det) (i.e., p(abd) congruent with 0) with the results of the urodynamics operator's opinion, the provisional International Continence Society method, Abrams and Griffith's diagram, urethral resistence factor (URA), Sch?fer's diagram, and Watt factor. PUMA curves correlated reliably with different pathologic conditions such as obstructive BPH, orthotopic bladder, cystocele, the neurological bladder, and bladder diverticulum. Statistical analysis indicated excellent agreement between PUMA and URA; agreement with other methods was good in cases of obstruction and nonobstruction. In doubtful cases, as diagnosed by standard methods, PUMA agreed only with the Abrams and Griffith's diagram. PUMA and Wmax were in good agreement on detrusor con traction force. Agreement between PUMA and Sch?fer's diagram was excellent for patients with detrusor hypercontractility and good for patients with detrusor hypocontractility and normocontractility. PUMA is the only method applicable to women. It is easy to perform. When integrated with other diagnostic tests, it provides realistic data for diagnosis, medical or surgical therapy, and outcome.  相似文献   
92.
目的 揭示大脑中动脉闭塞(MCAO)后丘脑钙调磷酸酶(CaN)的时空变化规律,探讨CaN的作用机制。方法 制备大鼠大脑中动脉永久性闭塞模型,分别测定缺血后不同时间点病灶侧丘脑CaN的活性和含量。结果 缺血后24h始丘脑CaN的含量下降且不恢复;CaN的活性在缺血后2h和4h减弱,6h始恢复至正常水平。可见,CaN的活性与含量分离。结论 大脑中动脉闭塞后丘脑CaN活性独特的时间变化规律显示其参与介导继发性丘脑损伤,可能具有毒性作用。  相似文献   
93.
目的:探讨靶重建放大扫描技术对肺孤立性结节病变的诊断价值。方法:对63例患者先行常规CT平扫,选定结节处为兴趣区,行薄层靶重建放大扫描,层厚、层距为2mm,FOV为160。结果:42例恶性病变中有37例表现为深分叶,占88.1%;21例良性病变中有15例表现为浅分叶,占71.4%。恶性结节中15例内部出现条状低密度支气管征;7例出现血管集中征;8例出现空泡征;病变内部出现液化坏死13例,其中恶性病变ll例。22例出现钙化,包括12例良性病变和10例恶性病变。2例错构瘤内均见小面积脂肪性低密度影。结论:靶重建放大扫描比普通CT扫描可提供更多的信息,对良恶性病变的鉴别诊断有一定价值。恶性病变大多数为深分叶,良性病变大多数为浅分叶或无分叶。  相似文献   
94.
Conjugated linoleic acid (CLA) is a unique lipid that elicits dramatic reductions in adiposity in several animal models when included at < or = 1% of the diet. Despite a flurry of investigations, the precise mechanisms by which conjugated linoleic acid elicits its dramatic effects in adipose tissue and liver are still largely unknown. In vivo and in vitro analyses of physiological modifications imparted by conjugated linoleic acid on protein and gene expression suggest that conjugated linoleic acid exerts its de-lipidating effects by modulating energy expenditure, apoptosis, fatty acid oxidation, lipolysis, stromal vascular cell differentiation and lipogenesis. The purpose of this review shall be to examine the recent advances and insights into conjugated linoleic acid's effects on obesity and lipid metabolism, specifically focused on changes in gene expression and physiology of liver and adipose tissue.  相似文献   
95.
In this work the feasibility of separating fat and water signals using the balanced steady-state free precession (SSFP) technique is demonstrated. The technique is based on the observation (Scheffler and Hennig, Magnetic Resonance in Medicine 2003;49:395-397) that at the nominal values of TE = TR/2 in SSFP imaging, phase coherence can be achieved at essentially only two orientations (0 degrees and 180 degrees ) relative to the RF pulses in the rotating frame, under the assumption of TR < T2, and independently of the SSFP angle. This property allows in-phase and out-of-phase SSFP images to be obtained by proper choices of the center frequency offset, and thus allows the Dixon subtraction method to be utilized for effective fat-water separation. The TR and frequency offset for optimal fat-water separation are derived from theories. Experimental results from healthy subjects, using a 3.0 Tesla system, show that nearly complete fat suppression can be accomplished.  相似文献   
96.
中风毒邪论是一种与传统中医中风病理有所不同的理论 ,在中风毒邪论指导下形成解毒通络方是较为理想的神经保护剂 ,可解决目前神经保护治疗的主要障碍 ,有望成为提高中医治疗中风急性期疗效的关键  相似文献   
97.
2008年连云港市“手足口病”流行特征及病原学分型   总被引:1,自引:0,他引:1  
宋华 《职业与健康》2010,26(2):191-193
目的分析连云港市2008年手足口病的流行特征及病原学分型情况。方法应用流行病学方法对2008年该市的手足口病流行资料进行分析。结果依据疫情报告,实验室诊断病例45例,其中CoxA1638例,EV71型7例,其他肠道病毒0例。2008年该市临床报告手足口病例1067例,报告发病率为23.19/10万,比2007年上升442.34%,男女发病比为3.1∶1。发病年龄最小的为0岁组,最大的为8岁;0~5岁组,共计发病976例,占总发数的91.47%。发病数的构成以散居儿童最多,占76.66%。地区分布:全市各个区县均有手足口病病例报告,但城区的总体发病率高于县。结论连云港市手足口病发病率有上升趋势;控制传染源是有效防止该病流行的关键。  相似文献   
98.
BACKGROUND: In an effort to improve the quality of life of children with cancer, this study analyzes the signs and symptoms at the end of life in such children. It is hoped that these data will contribute to the development of appropriate programs to address the challenges faced by these children. PROCEDURE: Between 1994 and 2000, 28 children died after treatment for cancer at Hamamatsu University Hospital, Japan. The circumstances, signs and symptoms at the end of life of these children were analyzed through their medical records. RESULTS: Of the 28 children, the underlying diseases were leukemia/lymphoma (LL group; n=11), brain tumors (BT group; n=7), and other solid tumors (OST group; n=10). Records showed poor appetite (100%), dyspnea (82.1%), pain (75.0%), fatigue (71.4%), nausea/vomiting (57.1%), constipation (46.4%) and diarrhea (21.4%) among these children. Anxiety was reported in 53.6% of the entire group of 28 children; however, no child in the BT group manifested anxiety. However, disturbance of consciousness was reported in all children in the BT group, which was significantly greater than in the other groups. Awareness, fear or acceptance of the imminence of his/her own death as indicated by verbal expression was reported in nine children (32.1%). CONCLUSIONS: Using the data obtained in the present study, we describe situations faced in the terminal care of children. It is important to address the problems revealed by this analysis in order to achieve improvements in both the physical and psychological care of children with terminal cancer.  相似文献   
99.
Milieu relationships provide the critical background presence to staff's attempts to motivate, regulate, and teach patients how to cope with stress. Forging a connection with hospitalized children and adolescents demands attention to how they respond to adults and engage with staff around milieu expectations. Assessment guides that deal with these issues are presented. Important aspects of children's relatedness are presented in the context of their working models of adults and the influence of these representations on their response to staff. Coping skills are explained with particular emphasis on behavioral coping strategies. Tied to the assessment process are interventions that emphasize staff's role in helping patients manage strong affects and avoid the use of nonproductive behavior regulation strategies.  相似文献   
100.
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups.  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