全文获取类型
收费全文 | 6908篇 |
免费 | 666篇 |
国内免费 | 26篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 211篇 |
妇产科学 | 143篇 |
基础医学 | 850篇 |
口腔科学 | 212篇 |
临床医学 | 793篇 |
内科学 | 1458篇 |
皮肤病学 | 107篇 |
神经病学 | 560篇 |
特种医学 | 291篇 |
外科学 | 672篇 |
综合类 | 117篇 |
一般理论 | 4篇 |
预防医学 | 818篇 |
眼科学 | 177篇 |
药学 | 670篇 |
中国医学 | 5篇 |
肿瘤学 | 486篇 |
出版年
2022年 | 38篇 |
2021年 | 123篇 |
2020年 | 72篇 |
2019年 | 101篇 |
2018年 | 109篇 |
2017年 | 77篇 |
2016年 | 89篇 |
2015年 | 132篇 |
2014年 | 168篇 |
2013年 | 235篇 |
2012年 | 304篇 |
2011年 | 288篇 |
2010年 | 196篇 |
2009年 | 161篇 |
2008年 | 295篇 |
2007年 | 325篇 |
2006年 | 306篇 |
2005年 | 331篇 |
2004年 | 327篇 |
2003年 | 288篇 |
2002年 | 289篇 |
2001年 | 268篇 |
2000年 | 246篇 |
1999年 | 208篇 |
1998年 | 116篇 |
1997年 | 102篇 |
1996年 | 84篇 |
1995年 | 84篇 |
1994年 | 74篇 |
1993年 | 77篇 |
1992年 | 161篇 |
1991年 | 160篇 |
1990年 | 133篇 |
1989年 | 145篇 |
1988年 | 130篇 |
1987年 | 131篇 |
1986年 | 120篇 |
1985年 | 116篇 |
1984年 | 86篇 |
1983年 | 82篇 |
1982年 | 60篇 |
1981年 | 60篇 |
1980年 | 41篇 |
1979年 | 56篇 |
1978年 | 59篇 |
1977年 | 38篇 |
1976年 | 48篇 |
1975年 | 42篇 |
1974年 | 38篇 |
1972年 | 37篇 |
排序方式: 共有7600条查询结果,搜索用时 18 毫秒
21.
22.
Nancy Ballard Lois Robley Darcy Barrett Danielle Fraser Inocencia Mendoza 《American journal of critical care》2006,15(1):86-94; quiz 95
BACKGROUND: Neuromuscular blocking agents used for therapeutic purposes, such as facilitating mechanical ventilation and relieving life-threatening agitation, paralyze patients but leave them fully conscious. Aggressive sedation or analgesia is necessary to reduce awareness, relieve fear, produce comfort, decrease anxiety, induce unconsciousness, and minimize possible complications such as posttraumatic stress syndrome. Little information is available on the extent to which patients experience awareness during therapeutic paralysis. OBJECTIVES: To determine and describe the remembered experiences of critical care patients who were given neuromuscular blocking agents and sedatives and/or analgesics to facilitate mechanical ventilation, improve hemodynamic stability, and improve oxygenation. METHODS: A phenomenological approach with in-depth interviews with 11 patients was used. Data were analyzed by using the constant comparative approach. RESULTS: A total of 4 themes and 3 subthemes were identified. The first theme was back and forth between reality and the unreal, between life and death; the subtheme was having weird dreams. The second theme was loss of control; the 2 subthemes were (1) fighting or being tied down and (2) being scared. The third theme was almost dying, and the fourth theme was feeling cared for. CONCLUSIONS: Patients can remember having both negative and positive experiences during neuromuscular blockade. Steps to improve the experiences of patients receiving neuromuscular blockers include improving assessment parameters, developing and using sedation/analgesia guidelines, and investing in quality improvement programs to provide assessment of awareness during therapeutic paralysis and follow-up and referral as necessary. Ways to decrease the use of neuromuscular blockers would also be useful. 相似文献
23.
24.
C Feinstein Y Kaminer R P Barrett B Tylenda 《Research in developmental disabilities》1988,9(2):109-121
There is an unmet need for a reliable method of evaluating disorders of mood and affect in developmentally disabled children and adolescents. Such a measure is required for both accurate diagnosis and treatment monitoring in this population. An extensive review of existing assessment techniques confirms that: (a) current techniques for the evaluation of emotional disorders in cognitively normal individuals are inappropriate for most children with developmental disabilities; and (b) current instruments designed for the assessment of developmentally disabled children pay inadequate attention to affective symptoms. In this paper, the preliminary version of a new instrument, the "Emotional Disorders Rating Scale for Developmental Disabilities" (EDRS-DD), designed to evaluate mood and affect in children and adolescents with developmental disabilities, is presented. A pilot study indicates that interrater agreement is good. 相似文献
25.
Event-related potentials and the semantic matching of faces 总被引:2,自引:1,他引:1
Event-related brain potentials (ERPs) were recorded while subjects determined whether two sequentially presented famous faces depicted individuals belonging to the same or to different occupational categories. During the 1.56 sec interval between the onset of the faces, ERPs recorded from right hemisphere electrodes were more negative-going than those from electrodes over the left hemisphere. The ERPs evoked by the second face on each trial differed as a consequence of whether or not the person depicted belonged to the occupational category specified by the first face. This difference took the form of a bilaterally-distributed negative-going shift in the ERPs evoked by non-matching as opposed to matching faces. This negativity was maximal around 450 msec post-stimulus. The ERP asymmetries during the inter-stimulus interval are interpreted as evidence for the engagement of cognitive processes lateralized to the right hemisphere. The match/non-match differences are considered to reflect the modulation of an "N400" component similar to that evoked by words, and thus suggest that such components can be modulated by associative priming between non-linguistic stimuli. 相似文献
26.
Savoie FH Wilkinson MM Bryan A Barrett GR Shelton WR Manning JO 《Journal of Athletic Training》1992,27(3):268-269
Ligamentous injuries of the ankle are usually benign and may be managed satisfactorily by nonoperative measures. This is not true, however, of the Maisonneuve variant. In this paper we present a case report of a high school athlete who sustained a Maisonneuve fracture dislocation of the ankle. The diagnosis was missed initially, because of an incomplete examination. The subsequent physical and radiographic examination revealed the proper diagnosis. Guidelines for the evaluation and appropriate treatment are discussed. 相似文献
27.
Factors associated with the provision of anti-smoking advice in general practice consultations. 下载免费PDF全文
Alison Wynn Tim Coleman Stephen Barrett Andrew Wilson 《The British journal of general practice》2002,52(485):997-999
Guidelines urge general practitioners (GPs) to discuss smoking with patients as frequently as possible. Using data collected before and after consultations, this study confirms that GPs are more likely to discuss smoking in the context of smoking-related problems. Encouraging GPs to make greater use of problem-orientated opportunities to discuss smoking may have more effect on rates of advice giving than urging them to advise all smokers. 相似文献
28.
Takeki Tsutsui Yuriko Tanaka Yuko Matsudo J. Carl Barrett 《Methods in Cell Science》1995,17(2):155-160
Immortalization of normal human fibroblasts is a very rare event. Multiple genes such as p53 and cellular senescence genes are possibly involved in immortalization of human fibroblasts, suggesting that multiple treatments with carcinogens are required for the immortalization. We describe here the procedure for immortalization of human fibroblasts (MDAH 087) from Li-Fraumeni cancer syndrome with a germ-line p53 mutation. The cells were subjected to multiple treatments with aflatoxin B1 (AFB1) in the presence of exogenous metabolic activation with rat liver post-mitochondrial supernatant (PMS), and 3 of 9 MDAH 087 cell cultures treated 1–3 times with 0.1–1 µg/ml AFB1 became immortal, defined as continuous growth for over 300 population doublings after the first treatment. However, cultures of human fibroblasts from a normal embryo treated under the same conditions failed to escape senescence. The results indicate that the model of human fibroblasts with a mutated p53 allele exposed to AFB1 is potentially useful for studying mechanisms of chemically induced immortalization. 相似文献
29.
Schecter AD Berman AB Yi L Ma H Daly CM Soejima K Rollins BJ Charo IF Taubman MB 《Journal of leukocyte biology》2004,75(6):1079-1085
Monocyte chemoattractant protein-1 (MCP-1, CCL2) is a mediator of inflammation that has been implicated in the pathogenesis of a wide variety of human diseases. CCR2, a heterotrimeric G-coupled receptor, is the only known receptor that functions at physiologic concentrations of MCP-1. Despite the importance of CCR2 in mediating MCP-1 responses, several recent studies have suggested that there may be another functional MCP-1 receptor. Using arterial smooth muscle cells (SMC) from CCR2(-/-) mice, we demonstrate that MCP-1 induces tissue-factor activity at physiologic concentrations. The induction of tissue factor by MCP-1 is blocked by pertussis toxin and 1,2-bis(O-aminophenyl-ethane-ethan)-N,N,N',N'-tetraacetic acid-acetoxymethyl ester, suggesting that signal transduction through the alternative receptor is G(alphai)-coupled and dependent on mobilization of intracellular Ca(2+). MCP-1 induces a time- and concentration-dependent phosphorylation of the mitogen-activated protein kinases p42/44. The induction of tissue factor activity by MCP-1 is blocked by PD98059, an inhibitor of p42/44 activation, but not by SB203580, a selective p38 inhibitor. These data establish that SMC possess an alternative MCP-1 receptor that signals at concentrations of MCP-1 that are similar to those that activate CCR2. This alternative receptor may be important in mediating some of the effects of MCP-1 in atherosclerotic arteries and in other inflammatory processes. 相似文献
30.
Image analysis derived ploidy and proliferation indices in soft tissue sarcomas: comparison with clinical outcome. 下载免费PDF全文
AIMS--To compare prognostic information obtained by image analysis cytometry of paraffin wax embedded soft tissue sarcomas with conventional assessment. METHODS--A CAS 200 image analyser was used to determine DNA content of Feulgen stained cytology preparations and tissue sections and to quantify immunostaining by Ki67 and PC10 antibodies. A mitotic count in 50 high power fields was undertaken and histological grade assigned by the Trojani system. Clinical details including follow up and outcome were obtained by case note review. The Kruskal-Wallis one way analysis test, Spearman rho significance test, Kaplan-Meier method, and log-rank test were applied in statistical analysis. RESULTS--Ploidy status, DNA index, 2.5c exceeding rate, 5c exceeding rate, mitotic count and Trojani grade all correlated significantly with clinical outcome. The relation between Ki67 index and outcome did not reach significance. The PC10 index and outcome were not related. Only 2.5c exceeding rate, 5c exceeding rate, and mitotic count correlated significantly with Trojani grade. CONCLUSIONS--DNA content determination of soft tissue sarcomas by image analysis provides quantifiable information of benefit in prediction of outcome. Larger series are required to determine the independent value of ploidy. In this study quantification of anti-Ki67 and anti-PC10 immunostaining was not of prognostic benefit) by contrast with mitotic count and Trojani grade. 相似文献