全文获取类型
收费全文 | 229573篇 |
免费 | 17071篇 |
国内免费 | 5889篇 |
专业分类
耳鼻咽喉 | 1407篇 |
儿科学 | 2766篇 |
妇产科学 | 3129篇 |
基础医学 | 25556篇 |
口腔科学 | 3752篇 |
临床医学 | 20122篇 |
内科学 | 37956篇 |
皮肤病学 | 2254篇 |
神经病学 | 15779篇 |
特种医学 | 8831篇 |
外国民族医学 | 1篇 |
外科学 | 16178篇 |
综合类 | 36131篇 |
现状与发展 | 22篇 |
一般理论 | 8篇 |
预防医学 | 16177篇 |
眼科学 | 2899篇 |
药学 | 31196篇 |
124篇 | |
中国医学 | 15444篇 |
肿瘤学 | 12801篇 |
出版年
2024年 | 186篇 |
2023年 | 2697篇 |
2022年 | 4002篇 |
2021年 | 8362篇 |
2020年 | 7743篇 |
2019年 | 7358篇 |
2018年 | 7417篇 |
2017年 | 8196篇 |
2016年 | 8469篇 |
2015年 | 7916篇 |
2014年 | 10749篇 |
2013年 | 14473篇 |
2012年 | 12272篇 |
2011年 | 14322篇 |
2010年 | 9728篇 |
2009年 | 9705篇 |
2008年 | 11194篇 |
2007年 | 12211篇 |
2006年 | 11691篇 |
2005年 | 10648篇 |
2004年 | 8972篇 |
2003年 | 8012篇 |
2002年 | 6442篇 |
2001年 | 5944篇 |
2000年 | 5022篇 |
1999年 | 4190篇 |
1998年 | 3186篇 |
1997年 | 3209篇 |
1996年 | 2833篇 |
1995年 | 2634篇 |
1994年 | 2534篇 |
1993年 | 2128篇 |
1992年 | 1920篇 |
1991年 | 1798篇 |
1990年 | 1541篇 |
1989年 | 1267篇 |
1988年 | 1235篇 |
1987年 | 1122篇 |
1986年 | 1027篇 |
1985年 | 1449篇 |
1984年 | 1161篇 |
1983年 | 848篇 |
1982年 | 880篇 |
1981年 | 726篇 |
1980年 | 690篇 |
1979年 | 538篇 |
1978年 | 356篇 |
1977年 | 300篇 |
1976年 | 267篇 |
1975年 | 197篇 |
排序方式: 共有10000条查询结果,搜索用时 26 毫秒
1.
《Journal of pediatric surgery》2023,58(7):1274-1280
BackgroundPerianal abscesses and anal fistulas are common. The principle of intention-to-treat has not been considered in previous systemic reviews. Thus, the comparison between primary and post-recurrence management was confused, and the recommendation of primary treatment is obscure. The current study aims to identify the optimal initial treatment for pediatric patients.MethodsUsing PRISMA guidelines, studies were identified from MEDLINE, EMBASE, PubMed, Cochrane Library, and Google Scholar without any language or study design restriction. The inclusion criteria include original articles or articles with original data, studies of management for a perianal abscess with or without anal fistula, and patient age of <18 years. Patients with local malignancy, Crohn's disease, or other underlying predisposing conditions were excluded. Studies without analyzing recurrence, case series of <5, and irrelevant articles were excluded in the screening stage. Of the 124 screened articles, 14 articles had no full texts or detailed information. Articles written in a language other than English or Mandarin were translated by Google Translation first and confirmed with native speakers. After the eligibility process, studies that compared identified primary managements were then included in the qualitative synthesis.ResultsThirty-one studies involving 2507 pediatric patients met the inclusion criteria. The study design consisted of two prospective case series of 47 patients and retrospective cohort studies. No randomized control trials were identified. Meta-analyses for recurrence after initial management were performed with a random-effects model. Conservative treatment and drainage revealed no difference (Odds ratio [OR], 1.222; 95% Confidential interval [CI]: 0.615–2.427, p = 0.567). Conservative management had a higher risk of recurrence than surgery without statistical significance (OR 0.278, 95% CI: 0.109–0.707, p = 0.007). Compared with incision/drainage, surgery can prevent recurrence remarkably (OR 4.360, 95% CI: 1.761–10.792, p = 0.001). Subgroup analysis of different approaches within conservative treatment and operation was not performed for lacking information.ConclusionStrong recommendations cannot be made due to the lack of prospective or randomized controlled studies. However, the current study based on real primary management supports initial surgical intervention for pediatric patients with perianal abscesses and anal fistula to prevent recurrence.Level of evidenceType of study: Systemic review; Evidence level: Level II. 相似文献
2.
Rolf Svedjeholm Gabriele Ferrari Farkas Vanky Örjan Friberg Jonas Holm 《Acta anaesthesiologica Scandinavica》2023,67(10):1373-1382
Background
Glutamate plays a key role for post-ischaemic recovery of myocardial metabolism. According to post hoc analyses of the two GLUTAMICS trials, patients without diabetes benefit from glutamate with less myocardial dysfunction after coronary artery bypass surgery (CABG). Copeptin reflects activation of the Arginine Vasopressin system and is a reliable marker of heart failure but available studies in cardiac surgery are limited. We investigated whether glutamate infusion is associated with reduced postoperative rises of plasma Copeptin (p-Copeptin) after CABG.Methods
A prespecified randomised double-blind substudy of GLUTAMICS II. Patients had left ventricular ejection fraction ≤0.30 or EuroSCORE II ≥3.0 and underwent CABG ± valve procedure. Intravenous infusion of 0.125 M L-glutamic acid or saline at 1.65 mL/kg/h was commenced 10–20 min before the release of the aortic cross-clamp and then continued for another 150 min P-Copeptin was measured preoperatively and postoperatively on day one (POD1) and day three. The primary endpoint was an increase in p-Copeptin from the preoperative level to POD1. Postoperative stroke ≤24 h and mortality ≤30 days were safety outcomes.Results
We included 181 patients of whom 48% had diabetes. The incidence of postoperative mortality ≤30 days (0% vs. 2.1%; p = .50) and stroke ≤24 h (0% vs. 3.2%; p = .25) did not differ between the glutamate group and controls. P-Copeptin increased postoperatively with the highest values recorded on POD1 without significant inter-group differences. Among patients without diabetes, p-Copeptin did not differ preoperatively but postoperative rise from preoperative level to POD1 was significantly reduced in the glutamate group (73 ± 66 vs. 115 ± 102 pmol/L; p = .02). P-Copeptin was significantly lower in the Glutamate group on POD1 (p = .02) and POD 3 (p = .02).Conclusions
Glutamate did not reduce rises of p-Copeptin significantly after moderate to high-risk CABG. However, glutamate was associated with reduced rises of p-Copeptin among patients without diabetes. These results agree with previous observations suggesting that glutamate mitigates myocardial dysfunction after CABG in patients without diabetes. Given the exploratory nature of these findings, they need to be confirmed in future studies. 相似文献3.
目的:分析子野个数限值对宫颈癌固定野调强放疗(fixed-field intensity-modulated radiotherapy,ff-IMRT)计划的影响,寻求最优的子野个数限值。方法:选取10例接受ff-IMRT的宫颈癌患者,基于Monaco 5.11.03计划系统,以45 Gy/25 f处方剂量分别对同一患者设计8种ff-IMRT计划(ff-IMRT计划依据子野个数限值命名,子野个数限值分别为40、60、70、80、100、120、130、150),采用SPSS 20.0软件比较除plan100之外7个ff-IMRT计划与plan100剂量学参数、优化时间和治疗参数的差异。结果:8种ff-IMRT计划归一化后,plan40和plan60的D2%、Dmin、CI和HI均劣于plan100(P<0.05)。8种ff-IMRT计划均能较好保护危及器官(organ at risk,OAR)和正常组织。plan40小肠V45;plan40和plan60小肠D2cc,直肠、膀胱V45、D40%,两侧股骨头V40和正常组织 V35、V40均高于plan100(P<0.05)。plan40和plan60优化时间、治疗参数均优于plan100(P<0.05);plan120、plan130和plan150子野面积、子野个数(51~150 cm2和>150 cm2)和出束时间均劣于plan100(P<0.05)。结论:子野个数限值为70~100时,ff-IMRT计划能兼顾剂量学参数满足临床要求、优化时间和治疗参数最优化,建议在设计宫颈癌ff-IMRT计划时在该范围内设置子野个数限值。 相似文献
4.
5.
6.
7.
8.
9.
《Journal of vascular and interventional radiology : JVIR》2022,33(3):249-254.e1
An ovine iliac vein thrombosis model was devised to test a wall-contacting rotational thrombectomy device. Thrombosis was successfully induced in 9 sheep with an average clot length of 31 mm ± 12 and >60% vessel occlusion on angiography. The thrombus was subsequently removed, maintaining normal intraoperative pulmonary arterial pressure (5.9 mm Hg ± 3.6) and complete distal reperfusion after thrombectomy. Additionally, the sheep were without signs of vascular trauma or embolic complications on gross necropsy and histopathologic analysis. The findings from this study support the use of an ovine iliac deep vein thrombosis model for testing of a lower extremity thrombectomy device. 相似文献
10.
《Radiography》2022,28(2):353-359
Patient contact shielding has been in use for many years in radiology departments in order to reduce the effects and risks of ionising radiation on certain organs. New technologies in projection imaging and CT scanning such as digital receptors and automatic exposure control (AEC) systems have reduced doses and improved image consistency. These changes and a greater understanding of both the benefits and the risks from the use of shielding have led to a review of shielding use in radiology. A number of professional bodies have already issued guidance in this regard. This paper represents the current consensus view of the main bodies involved in radiation safety and imaging in Europe: European Federation of Organisations for Medical Physics, European Federation of Radiographer Societies, European Society of Radiology, European Society of Paediatric Radiology, EuroSafe Imaging, European Radiation Dosimetry Group (EURADOS), and European Academy of DentoMaxilloFacial Radiology (EADMFR). It is based on the expert recommendations of the Gonad and Patient Shielding (GAPS) Group formed with the purpose of developing consensus in this area. The recommendations are intended to be clear and easy to use. They are intended as guidance, and they are developed using a multidisciplinary team approach. It is recognised that regulations, custom and practice vary widely on the use of patient shielding in Europe and it is hoped that these recommendations will inform a change management program that will benefit patients and staff. 相似文献