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   11397篇
  免费   829篇
  国内免费   263篇
耳鼻咽喉   475篇
儿科学   119篇
妇产科学   74篇
基础医学   847篇
口腔科学   351篇
临床医学   1033篇
内科学   787篇
皮肤病学   33篇
神经病学   1417篇
特种医学   402篇
外科学   3123篇
综合类   1482篇
一般理论   1篇
预防医学   748篇
眼科学   88篇
药学   735篇
  7篇
中国医学   412篇
肿瘤学   355篇
  2024年   13篇
  2023年   222篇
  2022年   353篇
  2021年   530篇
  2020年   574篇
  2019年   462篇
  2018年   427篇
  2017年   470篇
  2016年   486篇
  2015年   456篇
  2014年   916篇
  2013年   901篇
  2012年   660篇
  2011年   748篇
  2010年   667篇
  2009年   657篇
  2008年   555篇
  2007年   587篇
  2006年   476篇
  2005年   420篇
  2004年   351篇
  2003年   272篇
  2002年   208篇
  2001年   158篇
  2000年   122篇
  1999年   100篇
  1998年   94篇
  1997年   91篇
  1996年   73篇
  1995年   61篇
  1994年   39篇
  1993年   41篇
  1992年   39篇
  1991年   28篇
  1990年   30篇
  1989年   34篇
  1988年   28篇
  1987年   18篇
  1986年   16篇
  1985年   24篇
  1984年   18篇
  1983年   9篇
  1982年   14篇
  1981年   10篇
  1980年   6篇
  1979年   6篇
  1978年   4篇
  1977年   4篇
  1976年   6篇
  1975年   2篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
BackgroundLaparoscopic central bisectionectomy (Couinaud's segment IV, V, and VIII) needs exposure of the RHV and MHV on the surface of the remnant and the resecting side, respectively. Avoiding venous injury is mandatory and laparoscopy-specific cranio-caudal approach to hepatic veins might be helpful [1]. We present this procedure in performing laparoscopic central bisectionectomy.PatientA 45-year-old female was admitted to our hospital with a 6 cm HCC in the segment VIII and IV. Her comorbid disease was non-cirrhotic HBV hepatitis (Child-Pugh grade A) and diabetes (untreated).MethodAfter cholecystectomy, G4 branches were dissected and cut by extra- or intra-hepatic approach. Hilar plate was dissected and the Gant was encircled and occluded by a vascular clip. Afterwards, exposure of the MHV was started at its root on IVC [2,3] and extended in cranio-caudal direction [1]. After sufficient space was obtained around the Gant, the Gant and the MHV were cut. Parenchymal transection between right anterior and right posterior sections was also started form the root of the RHV to its cranio-caudal direction. Liver resection was finished with full exposure of the RHV.ResultsThe operating time was 380 minutes, and the blood loss volume was 30 ml. Postoperative CT image showed exposure of the RHV and umbilical portion of Glissonean branch, and no fluid retention.ConclusionLaparoscopy-specific cranio-caudal approach to hepatic veins may be useful to avoid split injury of venous branches [4], especially if the hepatectomy requires complete exposure of hepatic vein, such as central bisectionectomy.  相似文献   
43.
44.
In the Netherlands, safe and sufficient drinking water is provided to the general population by ten drinking water companies. To guarantee safe drinking water the World Health Organization (WHO) developed a Water Safety Plan (WSP), a Risk Assessment and a Risk Management (RA/RM) framework. The objective of the study was to identify legally required RA approaches, to document application of RA/RM activities at Dutch drinking water companies and to determine to what extent these RA/RM activities as a whole cover all the elements of the WHO WSP approach. This study could be of interest to both managers of large water utilities and decision makers.The assessment was performed by means of a policy review and interviews with two to four staff members involved in RA/RM from all ten Dutch drinking water companies combined with a joint workshop. The drinking water companies are well aware of the potential hazards and risks that can influence the drinking water quality. To guarantee the supply of safe and sufficient drinking water, the Dutch drinking water sector uses six different legally required RA/RM approaches. This study shows that by using the six legally required RA/RM approaches, all WSP steps are covered. WSP entails a generic risk assessment for identifying all hazards and hazardous events from source to tap, whereas the six legally required RA/RM each focus on specific risks at an advanced level. Each risk assessment provides information on specific hazards and hazardous events covering a part of the water supply chain. These legal requirements are complemented with additional RA/RM activities at sector and water company level such as codes of practices and standard operating procedures. The outcomes of all RA/RM approaches combined provide information from source to tap. When using multiple RA/RM approaches, it is crucial to share and combine information derived from the different activities.  相似文献   
45.
目的:探讨腹腔镜下中间入路右半结肠癌根治术的临床疗效及并发症。方法:回顾性分析在2015年6月1日至2018年6月1日期间由中国人民解放军第967医院普外科收治的82例右半结肠癌患者临床资料,45例患者接受腹腔镜中间入路右半结肠癌根治术,为中间入路组,37例患者接受腹腔镜侧方入路右半结肠癌根治术,为侧方入路组;对比两组患者手术时间、术中出血量、清扫淋巴结数量、中转开腹率、术后肠功能恢复时间、术后住院时间及术后并发症等临床指标,评价分析腹腔镜下中间入路右半结肠癌根治术的优越性。结果:中间入路组手术时间、术中出血量、淋巴结清扫数量、中转开腹率与侧方入路组相比差异显著,均有统计学意义(P<0.05);但中间入路组在术后肠功能恢复时间、术后住院时间及术后并发症发生情况等方面与侧方入路组相比无统计学差异(P>0.05)。结论:采用腹腔镜下中间入路右半结肠癌根治术能缩短手术时间、减少术中出血量、减少中转开腹率、增加清扫淋巴结个数,近期治疗效果满意,值得在临床中应用并推广。  相似文献   
46.
Background: The importance of conversation partners (CPs) for persons with aphasia (PwA) was recently highlighted. Trained CPs are shown to increase communicative access and improve quality of life. The Kagan scales, i.e., “Measure of skills in Supported Conversation” and “Measure of Participation in Conversation” (the MSC-MPC scales), between PwA and their CPs were designed to assess the communication dyad. The MSC-MPC scales were translated and adapted to Italian in 2015.

Aim: To validate the Italian version of the MSC-MPC scales (I-MSC/MPC) by assessing intra- and inter-rater reliability and concurrent validity.

Methods & Procedures: Thirty-two couples formed by 16 PwA and two CPs (one trained and one untrained) for each PwA were enrolled in the study. Aphasia severity was staged by the Therapy Outcome Measures “Dysphasia” impairment scale. Functional communication and pragmatic abilities were assessed with the I-ASHA-FACS and the Pragmatic Protocol, respectively. The PwA were videotaped while communicating both with trained and untrained CPs. All videotapes were assessed using the I-MSC/MPC scales by one expert speech and language therapist and two trainee speech and language therapists. The Intraclass Correlation Coefficient (ICC) was used to calculate inter- and intra-rater reliability. Correlations between the I-MSC/MPC scales and the aphasia severity, the I-ASHA-FACS, and the Pragmatic Protocol results were calculated by the Spearman’s test. The Mann-Whitney test was used to separate the I-MSC/MPC results obtained by the trained CPs from the untrained CPs.

Outcomes & Results: Inter-rater and intra-rater reliability ICC results were highly significant and strong (ICC > .906, ICC > .978, p < .001, respectively). Significant correlations between the aphasia severity and the I-MSC/MPC scales ranged from moderate to strong (Spearman rho>.487, p < .005). Correlations between the I-MSC and the I-ASHA-FACS domains ranged from moderate to strong (rho >.458, p < .008). Correlation between the I-MPC and the I-ASHA-FACS domains were generally strong (rho > .569, p < .001) while correlations between the I-MSC and the I-ASHA-FACS domains ranged from moderate to strong (rho > .458, p = .008). Pragmatic aspects were shown to be mostly preserved in the PwA. All correlations between the I-MSC/MPC scales and the Pragmatic Protocol were strong (rho >.635, p < .008). The Mann-Whitney test showed significant results for the I-MSC scale (p < .026).

Conclusions: The I-MSC-MPC scales proved to be a valid and reliable instrument to assess the communicative dyad. The I-MSC scale was also used to distinguish trained from untrained CPs. The use of I-MSC-MPC scales is recommended in clinical practice.  相似文献   

47.
48.
《The Journal of arthroplasty》2019,34(12):2962-2967
BackgroundEnthusiasm for anterior-based approaches for total hip arthroplasty (THA) continues to increase but there is concern for increased complications during the learning curve period associated. This study aimed to investigate if there was a difference in perioperative variables, intraoperative and immediate postoperative complications, or patient-reported outcomes when transitioning from a mini-posterior approach (mPA) to an anterior-based muscle-sparing (ABMS) approach for THA.MethodsRetrospective cohort study on the first 100 primary THA cases (n = 96 patients) of the senior author (August 2016 to August 2017) using the ABMS approach. These cases were compared to primary THA cases done the year prior (July 2015 to July 2016, n = 91 cases in 89 patients) using an mPA. Data were extracted and analyzed via gamma regression with robust standard errors and using generalized estimating equation regression.ResultsWe found no difference in the estimated blood loss (P = .452) and surgical time (P = .564) between the cohorts. The ABMS cases had a slightly shorter length of stay (P = .001) with an adjusted mean length of stay of 1.53 days (95% confidence interval 1.4-1.6) compared to 1.85 days (95% confidence interval 1.8-1.9) in the mPA cases. There was no difference in the frequency of immediate postoperative complications (all, P > .05). There was no difference in the adjusted mean change in patient-reported outcomes (all P > .05). In the ABMS group, there was no difference in surgical time or physical function computerized adaptive test between the first 20 cases (reference) and each subsequent group of 20 cases (all P > .05).ConclusionThis study demonstrates no associated learning curve for an experienced senior surgeon when switching routine THA approach from mPA to ABMS. We advise careful interpretation of our results, as they may not apply to all surgeons and practices.Level of EvidenceLevel III Therapeutic Study: retrospective comparative study.  相似文献   
49.
美国胃肠病协会(AGA)于2019年8月在Gastroenterology(《胃肠病学》)杂志上发表了针对胰腺坏死处理的临床实践专家共识的更新,归纳并总结了当前的临床证据与专家意见,旨在为胰腺坏死这一复杂临床情况的最佳干预提供指导建议。近年来,随着临床实践的不断深入,急性胰腺炎胰腺坏死的处理经历了较大的变革。从一开始的以手术为主的清创策略过渡到现阶段较为成熟的升阶梯治疗模式。针对胰腺坏死的治疗主要包含两个方面:非手术治疗和有创干预。其中,非手术治疗主要包括抗菌治疗和营养支持等。一旦坏死组织发生感染或无菌性坏死使病人产生显著临床症状,提示有强烈干预指征时,此时更多地依赖于有创干预。升阶梯治疗模式的主要内容为:以经皮引流或透壁内镜引流为首要手段,对于引流无法处理的大量固体坏死,可进行经皮微创或经内镜下坏死清除,若微创手段干预无效可进行开放手术清创。关于选择经皮微创阶梯治疗还是经内镜阶梯治疗,目前尚无研究显示两者之间对病死率等主要临床结局产生影响,不同治疗中心可根据各中心的专业特长和医疗资源,合理选择治疗方案。  相似文献   
50.
This study aimed at evaluating how encapsulation in a regular nanocarrier (NC) (providing extended circulation time) or in a brain-targeting NC (providing prolonged circulation time and increased brain uptake) may influence the therapeutic index compared with the unformulated drug and to explore the key parameters affecting therapeutic performance using a model-based approach. Pharmacokinetic (PK) models were built with chosen PK parameters. For a scenario where central effect depends on area under the unbound brain concentration curve and peripheral toxicity relates to peak unbound plasma concentration, dose-effect and drug-side effect curves were constructed, and the therapeutic index was evaluated. Regular NC improved the therapeutic index compared with the unformulated drug due to reduced peripheral toxicity, while brain-targeting NC enhanced the therapeutic index by lowering peripheral toxicity and increasing central effect. Decreasing drug release rate or systemic clearance of NC with drug still encapsulated could increase the therapeutic index. Also, a drug with shorter half-life would therapeutically benefit more from a NC encapsulation. This work provides insights into how a NC for brain delivery should be optimized to maximize the therapeutic performance and is helpful to predict if and to what extent a drug with certain PK properties would obtain therapeutic benefit from nanoencapsulation.  相似文献   
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