全文获取类型
收费全文 | 157054篇 |
免费 | 8687篇 |
国内免费 | 152篇 |
专业分类
耳鼻咽喉 | 2554篇 |
儿科学 | 5305篇 |
妇产科学 | 3575篇 |
基础医学 | 23508篇 |
口腔科学 | 4728篇 |
临床医学 | 13385篇 |
内科学 | 29124篇 |
皮肤病学 | 4725篇 |
神经病学 | 16097篇 |
特种医学 | 6606篇 |
外国民族医学 | 2篇 |
外科学 | 23819篇 |
综合类 | 840篇 |
一般理论 | 44篇 |
预防医学 | 9133篇 |
眼科学 | 3343篇 |
药学 | 10642篇 |
中国医学 | 237篇 |
肿瘤学 | 8226篇 |
出版年
2023年 | 889篇 |
2022年 | 570篇 |
2021年 | 1569篇 |
2020年 | 1360篇 |
2019年 | 1672篇 |
2018年 | 3513篇 |
2017年 | 2917篇 |
2016年 | 3727篇 |
2015年 | 3363篇 |
2014年 | 3637篇 |
2013年 | 6302篇 |
2012年 | 8464篇 |
2011年 | 9427篇 |
2010年 | 5189篇 |
2009年 | 3545篇 |
2008年 | 9137篇 |
2007年 | 9624篇 |
2006年 | 9305篇 |
2005年 | 9143篇 |
2004年 | 8598篇 |
2003年 | 8531篇 |
2002年 | 8408篇 |
2001年 | 5697篇 |
2000年 | 7115篇 |
1999年 | 4111篇 |
1998年 | 1601篇 |
1997年 | 1316篇 |
1996年 | 1021篇 |
1995年 | 876篇 |
1994年 | 853篇 |
1993年 | 803篇 |
1992年 | 936篇 |
1991年 | 869篇 |
1990年 | 794篇 |
1989年 | 821篇 |
1988年 | 685篇 |
1987年 | 775篇 |
1986年 | 663篇 |
1985年 | 893篇 |
1984年 | 779篇 |
1983年 | 688篇 |
1982年 | 664篇 |
1981年 | 646篇 |
1980年 | 584篇 |
1979年 | 612篇 |
1978年 | 541篇 |
1977年 | 569篇 |
1976年 | 478篇 |
1975年 | 523篇 |
1974年 | 488篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Pascale Jolliet Stéphane Nion Gwena?lle Allain-Veyrac L Tilloy-Fenart Dorothée Vanuxeem Vincent Berezowski Roméo Cecchelli 《Pharmacological research》2007,56(1):11-17
PURPOSE: The objective of the current study was to determine the ability of some antiemetic compounds to cross the blood-brain barrier (BBB) and thereby to determine possible side effects of compounds for the central nervous system (CNS). METHODS: We compared the brain penetration of some antiemetic compounds using an in vitro BBB model consisting in brain capillary endothelial cells co-cultured with primary rat glial cells. RESULTS: This study clearly demonstrated that the metopimazine metabolite, metopimazine acid, has a very low brain penetration, lower than metopimazine and even less than the other antiemetic compounds tested in this study. CONCLUSIONS: The poor brain penetration of metopimazine acid, metopimazine biodisponible form, seems very likely related to the clinically observed difference in therapeutic and safety profile. 相似文献
102.
Dietmar Georg PhD Bernhard Kroupa Petra Georg Peter Winkler Joachim Bogner Karin Dieckmann Richard Pötter 《Strahlentherapie und Onkologie》2006,182(8):473-480
PURPOSE: To compare commercial treatment-planning systems (TPS) for inverse planning (IP) and to assess constraint variations for specific IMRT indications. MATERIAL AND METHODS: For IP, OTP, XiO and BrainSCAN were used and step-and-shoot intensity-modulated radiotherapy (IMRT) delivery was assumed. Based on identical constraints, IP was performed for a prostate, head and neck, brain, and gynecologic case. IMRT plans were compared in terms of conformity/homogeneity, dose-volume histograms (DVHs), and delivery efficiency. For ten patients each of a class of indications, constraint variations were evaluated. RESULTS: IMRT plans were comparable concerning minimum target dose, homogeneity, conformity, and maximum doses to organs at risk. Larger differences were seen in dose gradients outside the target, monitor units, and segment number. Using help structures proved efficient to shape isodoses and to reduce segmentation workload. For IMRT class solutions, IP constraint variations depended on anatomic site. CONCLUSION: IP systems requiring doses as input and having objective functions based on physical parameters had a very similar performance. Constraint templates can be established for a class of IMRT indications. 相似文献
103.
104.
105.
Gastric cancer still represents the second most common cause of gastrointestinal cancers in Germany. A disturbing issue is that at the time of diagnosis there are less than 15% of patients for whom a cure can be achieved. Nowadays, biological, histomorphological, molecular genetic and epidemiological data suggest that Helicobacter pylori eradication may lead to the prevention of gastric pre-neoplastic lesions and even gastric cancer. At present, eradication can be offered to selected patients and populations at increased risk, but more research is required before embarking on general and global H. pylori eradication for gastric cancer prevention. The main challenge is to determine how long mucosal abnormalities remain reversible and gastric cancer development can be halted. 相似文献
106.
Birgitta Malmberg Göran Kecklund Björn Karlson Roger Persson Per Flisberg Palle Ørbaek 《BMC health services research》2010,10(1):239
Background
It is well known that physicians' night-call duty may cause impaired performance and adverse effects on subjective health, but there is limited knowledge about effects on sleep duration and recovery time. In recent years occupational stress and impaired well-being among anaesthesiologists have been frequently reported for in the scientific literature. Given their main focus on handling patients with life-threatening conditions, when on call, one might expect sleep and recovery to be negatively affected by work, especially in this specialist group. The aim of the present study was to examine whether a 16-hour night-call schedule allowed for sufficient recovery in anaesthesiologists compared with other physician specialists handling less life-threatening conditions, when on call. 相似文献107.
BACKGROUND: Necrotizing fasciitis (NF) is still a source of high morbidity and mortality. These difficult cases are increasingly referred to burn centers due to special wound and critical care issues. Here we examine our institution's recent experience with a large series of NF. METHOD: We performed a retrospective chart review of 32 consecutive patients over a 10-year period with NF who required radical surgical debridement and surface reconstruction. RESULTS: Overall survival was 85%, with average length of stay of 74.0+/-7.5 days for survivors (S) and 68.8+/-6.3 days for nonsurvivors (NS) (P>0.05). Time until first operation was 5.2 days in S and 3.4 days in NS (P<0.05). Patient age averaged 51.1+/-11.2 years for S and 57.0+/-12.0 years for NS (P<0.05). Survivors averaged 1.6 relevant comorbidities and NS averaged 3.6 (P<0.05). Affected total body surface (TBS) per patient averaged 6.8+/-3.3% for S and 10.2+/-5.1% for NS (P<0.05). All NS had affection of the trunk, and none of the patients with exclusive affection of extremities died. CONCLUSIONS: There were frequent delays in diagnosis and referrals to our institution, and progress can be made in educating the medical community to identify these patients. Not only the affected TBS and location but also comorbidities, age, and immediate surgical treatment are important prognostic factors. Referral to a specialized facility such as a burn center is urgently recommended for optimal surgical intervention, wound care, and critical care management. 相似文献
108.
109.
110.