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   2162篇
  免费   56篇
耳鼻咽喉   11篇
儿科学   102篇
妇产科学   75篇
基础医学   196篇
口腔科学   59篇
临床医学   383篇
内科学   539篇
皮肤病学   84篇
神经病学   93篇
特种医学   1篇
外科学   253篇
综合类   4篇
一般理论   18篇
预防医学   147篇
眼科学   42篇
药学   160篇
肿瘤学   51篇
  2017年   12篇
  2016年   25篇
  2015年   33篇
  2014年   24篇
  2013年   64篇
  2012年   27篇
  2011年   11篇
  2010年   73篇
  2009年   88篇
  2008年   28篇
  2007年   24篇
  2006年   25篇
  2003年   18篇
  2001年   27篇
  2000年   25篇
  1999年   60篇
  1998年   96篇
  1997年   122篇
  1996年   113篇
  1995年   86篇
  1994年   71篇
  1993年   73篇
  1992年   70篇
  1991年   62篇
  1990年   52篇
  1989年   62篇
  1988年   66篇
  1987年   52篇
  1986年   54篇
  1985年   48篇
  1984年   56篇
  1983年   35篇
  1982年   52篇
  1981年   56篇
  1980年   48篇
  1979年   33篇
  1978年   28篇
  1977年   27篇
  1976年   23篇
  1975年   20篇
  1974年   17篇
  1973年   11篇
  1972年   18篇
  1971年   17篇
  1970年   24篇
  1969年   11篇
  1967年   11篇
  1966年   10篇
  1956年   11篇
  1954年   15篇
排序方式: 共有2218条查询结果,搜索用时 31 毫秒
41.
Aldicarb Immunotoxicity: Functional Analysis of Cell-MediatedImmunity and Quantitation of Lymphocyte Subpopulations. THOMAS,P., RATAJCZAK, H., DEMETRAL, D., HAGEN, K., AND BARON, R. (1990).Fundam. Appl. Toxicol. 15, 221–230. Adult female B6C3F1mice received distilled water only or water containing 1.0,10, or 100 ppb of aldicarb daily for 34 days. The target concentrationof aldicarb present in the 100 ppb dosing solution was analyticallyverified. To further develop an immune profile of this compound,following aldicarb exposure, the ability of splenic naturalkiller cells and specifically sensitized cytotoxic T-lymphocytesto lyse YAC-1 lymphoma and P815 tumor cells, respectively, wasevaluated. To supplement the functional assays, the impact ofaldicarb exposure on the percentages and absolute numbers oftotal T-cells, T-suppressor, T-helper, and B-cells was evaluated.The absence of statistically significant effects on any of theseparameters supports earlier reports that aldicarb does not resultin adverse effects on the immune system of mice.  相似文献   
42.
We describe the establishment of a joint alcohol misuse clinic,staffed by both a psychiatrist and a physician, in a LondonTeaching Hospital providing general as well as specialist medicalservices. The demographic and medicopsychiatric problems ofthe first 100 referrals (60% attendance rate) are described.The clinic provides an assessment and re-education role formost patients referred with alcohol misuse problems: the needfor specialist alcohol treatment facilities, especially forin-patients, remains essential. In addition, the clinic providesa valuable training and research resource.  相似文献   
43.
The Noninvasive Mouse Ear Swelling Assay. I. Refinements forDetecting Weak Contact Sensitizers. THORNE, P. S., HAWK, C,KAUSZEWSKI, S. D., AND GUINEY, P. D. (1991). Fundam. Appl. Toxicol.17, 790–806. The noninvasive mouse ear swelling assay(MESA) is a model for delayed-type hypersensitivity that holdspromise as a testing protocol for allergic contact dermatitis(ACD). The MESA employs only topical sensitization on the abdomenand does not use injections, adjuvants, anesthesia, occlusion,or disruption of the stratum comeum. Five days after induction,the ears are challenged topically and ear swelling measurementstaken at 24,48, and 72 hr indicate the extent of ACD. In thisstudy, refinements of the assay were explored in BALB/cBy miceusing dinitrofluorobenzene (DNFB) and dinitrochlorobenzene (DNCB).A complete dose-response curve was developed for DNFB and thedose which sensitized half the mice in a group (SD50, 0.001%,w/v) was used to test noninvasive enhancement protocols. Severaltriple-dose protocols tested produced no increase in responsivenessand daily dosing showed a trend toward tolerance induction yielding20% positive responses. Dietary vitamin A supplementation produceda dramatic enhancement of the responses: ear thickness increasewas doubled and the SD50 sensitized 94 to 100% of the mice inthe vitamin A groups. We conclude that the MESA allowed identificationof ACD potency for known sensitizers at very low concentrationswhich do not produce ACD with other techniques. The importanceof dose-response studies for avoiding the high-dose reduced-responseregion was also shown. Based on the observation that the vitaminA-augmented MESA was considerably more sensitive than with regularfeed, a companion study (P. S. THORNE, C. HAWK, S. D. KALISZEWSKI,P. D. GUINEY, Fundam. Appl. Tox. 17, 807–820, 1991) presentstests of the enhancements to the MESA developed in this work,using weak sensitizers and complex mixtures.  相似文献   
44.
Context: The Disclosure, Apology, and Offer (DA&O) model, a response to patient injuries caused by medical care, is an innovative approach receiving national attention for its early success as an alternative to the existing inherently adversarial, inefficient, and inequitable medical liability system. Examples of DA&O programs, however, are few. Methods: Through key informant interviews, we investigated the potential for more widespread implementation of this model by provider organizations and liability insurers, defining barriers to implementation and strategies for overcoming them. Our study focused on Massachusetts, but we also explored themes that are broadly generalizable to other states. Findings: We found strong support for the DA&O model among key stakeholders, who cited its benefits for both the liability system and patient safety. The respondents did not perceive any insurmountable barriers to broad implementation, and they identified strategies that could be pursued relatively quickly. Such solutions would permit a range of organizations to implement the model without legislative hurdles. Conclusions: Although more data are needed about the outcomes of DA&O programs, the model holds considerable promise for transforming the current approach to medical liability and patient safety.  相似文献   
45.
46.
International Journal of Paediatric Dentistry 2012; 22: 427–434 Aims. To ascertain whether deproteinization pretreatment of molar‐incisor hypomineralization (MIH) enamel affects resin sealant infiltration. Design. Thirty one extracted MIH teeth were divided into three sections and randomly allocated into the Control (etch and FS), Treatment 1 (5% NaOCl, etched and fissure sealed), and Treatment 2 (5% NaOCl and fissure sealed with no etch) groups. Two hundred seventy nine sealant tag/enamel grade observations were recorded by scanning electron microscopy. Results. Control and Treatment 1 were similar in their outcomes, and Treatment 2 was markedly different. There was no statistical evidence to suggest that there was any difference between Treatment 1 and the Control Treatment (95% CI, 0.52, 1.51; P = 0.6). There was a marked difference between Treatment 2 and the Control Treatment (95% CI, 0.07, 0.25; P < 0.001). All treatments also demonstrated a high‐predicted probability of obtaining ‘poor’ sealant tags (Control = 47%, Treatment 1 = 49%, and Treatment 2 = 40%). Conclusions. The findings suggest that there was no significant difference in the tag quality between the conventional technique (Control) and the ‘bleach‐etch‐seal’ technique (Treatment 1). There was no benefit in pre‐treating with NaOCl alone (without etch) before sealing. This research also showed that there was a high‐predicted probability of obtaining ‘poor’ sealant tags in MIH enamel, regardless of which of the three treatments was used.  相似文献   
47.
kevern p. (2012) Journal of Nursing Management  20, 981–989
Who can give ‘spiritual care’? The management of spiritually sensitive interactions between nurses and patients Aims This article considers the purpose of contemporary ‘spiritual care’ in order to help managers make informed decisions about its appropriate delivery in a clinical context. Background Although there are national policies in place concerning spiritual care, surveys indicate that nurses are reluctant to engage with the spiritual needs of patients. Evaluation A consideration of the character of spiritual care indicates the need to take account of the context of contemporary Western society. A model drawn from the social psychology of religion is used to analyse the different types of nurse–patient interaction available in the provision of spiritual care. Key Issues Although religious and spiritual commitments can vary widely, they are subject to the same pressures in a secular and pluralist social context. This enables some general guidelines to be developed. Conclusions Effective spiritual care requires a consideration of both the patient’s and the nurse’s implicit and explicit religious commitments. Implications for nursing management Nurse managers need to take account of the personal commitments of nurses when directing them to offer spiritual care. This article offers a diagnostic tool for deploying nurses in an appropriate way.  相似文献   
48.
Gastric and oesophageal emptying in insulin-dependent diabetes mellitus   总被引:4,自引:0,他引:4  
Abstract Gastric emptying of a digestible solid and liquid meal and oesophageal emptying of a solid bolus were measured with scintigraphic techniques in 45 randomly selected insulin-dependent diabetics and in 22 control subjects. In the diabetics, the relationships between oesophageal emptying, gastric emptying, age, duration of diabetes mellitus, upper gastrointestinal symptoms, glycaemic control and the complications, autonomic neuropathy, peripheral neuropathy and retinopathy were examined. The lag period before solid food left the stomach was not significantly different in diabetics compared with control subjects, but the percentage retention of solid food at 100 min was greater ( P < 0.001) in the diabetic subjects. Both the early phase (percentage retention at 10 min) and the 50% emptying time for liquid gastric emptying were delayed ( P < 0.001) in the diabetic subjects. Of the diabetics, 58% had delayed gastric emptying of either the solid and/or the liquid meal; oesophageal emptying was delayed in 42%. Upper gastrointestinal symptoms correlated poorly with both gastric and oesophageal emptying. Oesophageal emptying, solid gastric emptying and the liquid 50% emptying time correlated with the severity of autonomic nerve dysfunction ( P < 0.05). The early phase of liquid emptying (retention at 10 min) was significantly slower ( P < 0.05) in patients with mean plasma glucose concentrations of > 15 mmol/l during the gastric emptying test and the lag period for solid emptying correlated with both the glycosylated haemoglobin and mean plasma glucose concentrations.  相似文献   
49.
α1-Receptor Subtype Stimulation of Purkinje Fibers. Introduction: Previously we found that WB4101 (WB) 10-7 M competitively blocks three α1-adrenergic receptor-effector responses: the increase in normal automaticity occurring in Purkinje fibers (PF) at high membrane potentials: the increase in abnormal automaticity occurring in PF at depolarized membrane potentials; and the prolongation of PF action potential duration. These observations are consistent with two different hypotheses: (1) WB blocks a single α1-receptor subtype, which subserves different effector pathways; and (2) WB blocks different receptor subtypes, eacb of which subserves an independent patbway. The aim of this study was to test both hypotheses. Methods and Results: We used standard microelectrode techniques to study the concentration-dependent actions of three α1-adrenoreceptor blockers (WB (α1A1D], 5-methylurapidil [5-MU] [α1A, ?α1D], and UK52,046 [nonselective]) on norepinephrine (NK) effects in normal PF and in PF depolarized with a simulated ischemic solution ([K+]o= 10 mM; pO2 < 20 mmHg; pH 6.8; maximum diastolic potential -60 ± 1 mV). In normally polarized PF, concentration-dependent actions of all blockers on both the positive cbronotropic response and the prolongation of action potential duration completely coincide. In contrast, the response to NE of abnormal automaticity in “ischemic” PF differs from normals: there is a bigh sensitivity to WB and 5-MU and no response to UK52,046. Conclusions: (1) A single receptor subtype appears responsible for botb the α1-induced prolongation of repolarization and the positive chronotropic effect in normal PF. (2) Two different receptor subtypes may be responsible for the α1-induced effects on automaticity in normal and ischemic fibers. It is likely that the latter one is α1A, and that consideration of antiarrhythmic therapy with α1-adrenergic blockers should focus on this subtype as a potential target.  相似文献   
50.
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