全文获取类型
收费全文 | 17159篇 |
免费 | 1036篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 215篇 |
儿科学 | 520篇 |
妇产科学 | 381篇 |
基础医学 | 2525篇 |
口腔科学 | 910篇 |
临床医学 | 1994篇 |
内科学 | 3310篇 |
皮肤病学 | 362篇 |
神经病学 | 1553篇 |
特种医学 | 308篇 |
外科学 | 1395篇 |
综合类 | 127篇 |
一般理论 | 10篇 |
预防医学 | 2061篇 |
眼科学 | 300篇 |
药学 | 1132篇 |
中国医学 | 84篇 |
肿瘤学 | 1074篇 |
出版年
2024年 | 19篇 |
2023年 | 180篇 |
2022年 | 355篇 |
2021年 | 684篇 |
2020年 | 408篇 |
2019年 | 612篇 |
2018年 | 653篇 |
2017年 | 468篇 |
2016年 | 466篇 |
2015年 | 570篇 |
2014年 | 741篇 |
2013年 | 923篇 |
2012年 | 1456篇 |
2011年 | 1577篇 |
2010年 | 768篇 |
2009年 | 678篇 |
2008年 | 1164篇 |
2007年 | 1104篇 |
2006年 | 1036篇 |
2005年 | 930篇 |
2004年 | 789篇 |
2003年 | 753篇 |
2002年 | 724篇 |
2001年 | 102篇 |
2000年 | 78篇 |
1999年 | 73篇 |
1998年 | 138篇 |
1997年 | 87篇 |
1996年 | 74篇 |
1995年 | 61篇 |
1994年 | 59篇 |
1993年 | 54篇 |
1992年 | 35篇 |
1991年 | 39篇 |
1990年 | 36篇 |
1989年 | 16篇 |
1988年 | 19篇 |
1987年 | 25篇 |
1986年 | 28篇 |
1985年 | 22篇 |
1984年 | 27篇 |
1983年 | 28篇 |
1982年 | 29篇 |
1981年 | 25篇 |
1980年 | 25篇 |
1979年 | 17篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1975年 | 10篇 |
1930年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Neuropsychiatric symptoms are common in older adults with dementia and can be associated with a rapid decline in cognitive and functional status. This article reviews the current literature supporting the use of atypical antipsychotic medications in this population. Among the currently available atypical antipsychotics, risperidone and olanzapine have been the most widely studied in double-blind, randomized, placebo-controlled clinical trials. Despite the common use of other atypical antipsychotic medications, their efficacy and safety in older adults with dementia has not been as extensively studied. Some controversy surrounds the use of atypical antipsychotic agents in older adults with the suggestion that they may increase the incidence of stroke or even death. Despite the potential for increased risk of harm from the use of these medications, atypical antipsychotics are often effective in treating troublesome neuropsychiatric symptoms refractory to other treatments. Whenever possible, these atypical antipsychotic drug treatments should be combined with non-pharmacological treatments to limit the need and dose of antipsychotic drugs and constant monitoring for potential harms should be maintained. The choice of which atypical antipsychotic agent can be guided by the nature and severity of the target symptom and the medication least likely to cause harm to the patient. 相似文献
42.
43.
Psychiatric Quarterly - 相似文献
44.
We report a malformed infant with a de novo interstitial deletion of 4q. This is the second patient reported with del(4) (q25q27). Although there are several common features such as marked hypotonia, cardiac abnormalities, cleft palate, and micrognathia noted in our case and that of Chudley et al. (1988), we conclude from our comparison of the seven previously reported cases involving deletions of bands 4(q25q27) that a specific phenotype cannot yet be described for this deletion. 相似文献
45.
BACKGROUND: When and whether early enteral nutrition (EN) benefits critically ill patients is debatable. This prospective clinical audit aimed to evaluate the feasibility of an early EN protocol and to identify factors that may hinder EN delivery in critically ill patients. METHODS: Thirty-six medical patients with severe respiratory failure under invasive ventilation and scheduled to receive early EN, with a length of ICU stay >72 hours, were included. As asserted by the Society of Critical Care Medicine, 8% of patients were priority 1, 72% priority 2, and 20% priority 3 for intensive therapeutic and vital support interventions. RESULTS: Overall, because of gastrointestinal complications, only 39% of the prescribed EN was administered; only 8 (22%) patients did tolerate EN within the first 48 hours after admission and did achieve their minimum nutritional requirements. The most frequent complication (78%) was high volume of gastric residuals followed by abdominal distention (61%), both associated with hemodynamic instability (HI). Gastrointestinal dysfunction was associated with high Acute Physiologic and Chronic Health Evaluation II score (p = .01), total calorie intake (p = .02), total carbohydrate intake (p = .02), HI (p = .03), malnutrition (p = .04), volume of IV saline (p = .04), and concurrent vasoactive drug administration (p = .05). CONCLUSIONS: This audit in extremely severe intensive care patients identified several factors that impair gastrointestinal function and preclude EN at any stage, namely early EN. Nutrition management must take into account concurrent therapies, given their potential interference with nutrition and organ function. 相似文献
46.
47.
48.
A tailored proficiency test programme in high-resolution gamma-spectrometric analysis has been established for the radionuclide laboratories designated to support the verification of the Comprehensive Nuclear-Test-Ban Treaty (CTBT). It entails certified reference samples that contain fission products relevant to the CTBT. The sample geometries and materials correspond to aerosol filter samples from the high-volume samplers of the radionuclide stations of the International Monitoring System (IMS) and the related calibration sources are matrix and geometry matched to the reference samples. 相似文献
49.
Frances Chung Doris Tong Paula C. Miceli Joseph Reiz Zoltan Harsanyi Andrew C. Darke Lance W. Payne 《Journal canadien d'anesthésie》2004,51(3):216-221
PURPOSE: Following ambulatory surgery, long-acting analgesics may provide advantages over short-acting analgesics. This study compared controlled-release codeine (CC) and acetaminophen plus codeine (A/C; 300 mg/30 mg) for pain control in the 48-hr period following laparoscopic cholecystectomy. METHODS: Eligible patients were randomized to CC or A/C in a double-blind, double-dummy parallel group study. Unrelieved pain in hospital was treated with fentanyl i.v. bolus. Pain [100 mm visual analogue scale (VAS)] was assessed before the first dose of medication; at 0.5, one, two, three, and four hours post-dose; at discharge; and three times a day for 48 hr. Adverse events were recorded and measures of patient satisfaction were assessed at the end of the study. RESULTS: Eighty-four patients were enrolled in the study; 42 patients in each group. There were no statistically significant differences between CC and A/C treatment. Mean VAS baseline pain was similar in both groups (P = 0.49) and there was no significant difference in the time to onset of analgesia (P = 0.17). At 0.5 hr, the mean VAS pain score was significantly reduced from baseline in both groups (P = 0.0001). The VAS pain scores at discharge were reduced 59% and 56% from baseline, respectively (P = 0.61). There was no difference between treatments in the incidence of adverse events and patients reported similar levels of satisfaction. CONCLUSIONS: Controlled-release codeine provides an equivalent onset of analgesia, reduction in postoperative pain, and level of patient satisfaction, to acetaminophen plus codeine, over 48 hr following cholecystectomy, with the advantage of less frequent dosing. 相似文献
50.
Antonio C Pastorino Rejane D C Rimazza Cláudio Leone Ana Paula M Castro Dirceu Solé Cristina M A Jacob 《The Journal of asthma》2006,43(9):695-700
BACKGROUND: Identify risk factors for asthma in adolescents from S?o Paulo, Brazil. METHODS: total of 528 adolescents (141 asthmatics, 387 control subjects) from the ISAAC study (phase III) were submitted to a complementary questionnaire to evaluate risk factors, through response to questions regarding personal history, environment, and diet and an agreement to undergo the skin prick test (SPT) for aeroallergens. RESULTS: Positive SPT to at least one allergen occurred in 49.4% adolescents. The risk factors for asthma were: prematurity (OR: 3.84, 95% CI: 1.54-9.64), rhinitis (OR: 3.18, 95% CI: 1.71-5.91), positivity in the SPT (OR: 2.81, 95% CI: 1.48-5.32), eczema in characteristic skin-folds (OR: 2.86, 95% CI: 1.13-7.26), and an allergic mother (OR: 2.01, 95% CI: 1.02-3.93). The consumption of cooked vegetables was a protective factor for asthma (OR: 0.37, 95% CI: 0.18-0.79) CONCLUSIONS: Asthma is a multifatorial disease. An allergic mother, aeroallergen sensitization, rhinitis, eczema and prematurity were considered risk factors and the consumption of cooked vegetables was considered a protective factor for asthma in this population. 相似文献