全文获取类型
收费全文 | 5326篇 |
免费 | 414篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 208篇 |
妇产科学 | 164篇 |
基础医学 | 547篇 |
口腔科学 | 141篇 |
临床医学 | 384篇 |
内科学 | 1304篇 |
皮肤病学 | 189篇 |
神经病学 | 336篇 |
特种医学 | 355篇 |
外科学 | 840篇 |
综合类 | 86篇 |
预防医学 | 448篇 |
眼科学 | 103篇 |
药学 | 335篇 |
中国医学 | 30篇 |
肿瘤学 | 216篇 |
出版年
2023年 | 29篇 |
2022年 | 60篇 |
2021年 | 129篇 |
2020年 | 82篇 |
2019年 | 143篇 |
2018年 | 172篇 |
2017年 | 117篇 |
2016年 | 90篇 |
2015年 | 122篇 |
2014年 | 186篇 |
2013年 | 217篇 |
2012年 | 313篇 |
2011年 | 288篇 |
2010年 | 233篇 |
2009年 | 213篇 |
2008年 | 273篇 |
2007年 | 264篇 |
2006年 | 224篇 |
2005年 | 234篇 |
2004年 | 227篇 |
2003年 | 209篇 |
2002年 | 190篇 |
2001年 | 147篇 |
2000年 | 156篇 |
1999年 | 119篇 |
1998年 | 113篇 |
1997年 | 83篇 |
1996年 | 105篇 |
1995年 | 73篇 |
1994年 | 62篇 |
1993年 | 55篇 |
1992年 | 76篇 |
1991年 | 75篇 |
1990年 | 63篇 |
1989年 | 66篇 |
1988年 | 68篇 |
1987年 | 66篇 |
1986年 | 51篇 |
1985年 | 31篇 |
1984年 | 29篇 |
1983年 | 31篇 |
1982年 | 18篇 |
1981年 | 22篇 |
1980年 | 20篇 |
1979年 | 23篇 |
1977年 | 23篇 |
1975年 | 19篇 |
1974年 | 16篇 |
1973年 | 19篇 |
1971年 | 21篇 |
排序方式: 共有5753条查询结果,搜索用时 15 毫秒
1.
José A. Lorente Pablo Cardinal-Fernández Diego Muñoz Fernando Frutos-Vivar Arnaud W. Thille Carlos Jaramillo Aida Ballén-Barragán José M. Rodríguez Oscar Peñuelas Guillermo Ortiz José Blanco Bruno Valle Pinheiro Nicolás Nin María del Carmen Marin Andrés Esteban Taylor B. Thompson 《Intensive care medicine》2015,41(11):1921-1930
2.
Eduardo Krajewski Ian S Soriano Jorge Ortiz 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2006,10(4):426-431
BACKGROUND: Solid-organ transplantation has become the treatment of choice for patients with end-stage renal disease, end-stage liver failure, and some patients with type 1 diabetes mellitus. Similarly, surgical expertise and mechanical improvements have led to significant advances in laparoscopic surgery. Laparoscopic interventions are sometimes not pursued in transplant recipients due to the lack of strong supporting evidence for the use of laparoscopic techniques in these patients. METHODS: Using an extensive literature search, we review herein the available data on the utility of laparoscopic interventions in transplant recipients, with particular attention to the risks and benefits, indications, and contraindications for this complex patient population. RESULTS: Although randomized trials are few, multiple case reports indicate that many transplant recipients have benefited from laparoscopic interventions. CONCLUSION: The well-known benefits of laparoscopy could be extended to transplant recipients. 相似文献
3.
4.
Evidence that dopamine in the nucleus accumbens is involved in the ability of rats to switch to cue-directed behaviours. 总被引:2,自引:0,他引:2
R van den Bos G A Charria Ortiz A C Bergmans A R Cools 《Behavioural brain research》1991,42(1):107-114
Recently we have reported that injections of d-amphetamine into the nucleus accumbens enhanced the number of switches to cue-directed behaviours without an effect on the number of switches to non-cue-directed behaviours in a swimming test. In the present study we investigated to what extent this effect is mediated via the dopaminergic system in the nucleus accumbens. For that purpose drugs selective for D1- and D2-receptors were studied in this swimming test. It was found that the selective D2-agonist LY 171 555 (50 ng/0.5 microliters) enhanced the number of different cue-directed behaviours. The selective D2-antagonist raclopride (50 ng/0.5 microliters) decreased it. Furthermore an ineffective dose of raclopride attenuated the effect of LY 171 555. Both the selective D1-antagonist SCH 23390 (400 ng/0.5 microliters) and the selective D1-agonist SKF 38393 (50-400 ng/0.5 microliters) decreased the number of different cue-directed behaviours. The effect induced by SCH 23390 could not be blocked by SKF 38393. Similarly the effect induced by SKF could not be attenuated by SCH 23390. These data point to a role for dopamine D2-receptors in the ability to switch to cue-directed behaviours. The present findings do not yet allow the conclusion that D1-receptors are involved. 相似文献
5.
Marco Antonio Palma Rocio Ortiz Carlos Alvarez-Dardet Maria T. Ruiz 《Social science & medicine (1982)》2009
The possible effect of Government Consumption (a component of Gross Domestic Product (GDP)) on attainment of the hunger Millennium Development Goal (MDG1) was analyzed by evaluating the effect of macroeconomic, social, demographic and policy variables on average undernourished population. Eighty-four developing countries with data available on undernourished population were included in an ecological study. Regression models were applied to explore possible determinants of Undernourished between 1990 and 2004 and consequent achievement of the projected 2004 MDG1. In 2004, 1.4% of the overall undernourished population in the studied countries [70.16 million people] was in excess of the projected level required to meet MDG1. The multiple linear regression showed significant associations between Undernourished and poverty levels, the Gini Index, rural population and Government Consumption. The multiple logistic regression showed significant associations between achievement of projected 2004 MDG1 levels and Government Consumption and the Gini Index. The significant associations between Undernourished and Government Consumption suggest that the effects of GDP components on social conditions call for more thorough research and that policymakers such as governments and international financial institutions need to ensure that changes in distributive and redistributive policies do not negatively affect the possibility of achieving MDG1. 相似文献
6.
Arthroscopic acromioplasty. Technique and results 总被引:3,自引:0,他引:3
D W Altchek R F Warren T L Wickiewicz M J Skyhar G Ortiz E Schwartz 《The Journal of bone and joint surgery. American volume》1990,72(8):1198-1207
Of forty-four patients who were treated by arthroscopic acromioplasty from July 1984 through August 1986, forty were available for analysis. The average age was 43.2 years, and 86 per cent of them had participated regularly in sports but were disabled due to symptoms of impingement. All patients had had a minimum of six months of non-operative therapy. The final diagnoses, which were based on the findings at arthroscopy and on clinical examination, plain radiographs, and arthrograms, were Stage-II impingement in twenty-four patients, a partial-thickness tear of the rotator cuff in six, and a full-thickness tear of the rotator cuff in ten. The shoulders were scored before the operation and again at follow-up. Preoperatively, thirty-six shoulders were rated as poor and four, as fair. After a minimum follow-up of twelve months (average, seventeen months), the scores had increased in all but one patient. The result was rated good or excellent in twenty-nine (73 per cent) of the forty patients: twenty of the twenty-four who had Stage-II impingement, four of the six who had a partial-thickness tear, and six of the ten who had a full-thickness tear. The over-all average time to return to work was nine days, and the average time to return to sports was 2.4 months. Of the thirty-three patients who had participated in sports, twenty-five (76 per cent) had returned to sports activity at the time of the most recent follow-up. The average time until full recovery was 3.8 months. There were no complications, and, over-all, thirty-eight (92 per cent) of the forty patients were satisfied with the result. In four patients, the result was a failure, and three of the four had a reoperation that relieved the symptoms. 相似文献
7.
目的 探讨创伤后迟发性脑肿胀的临床特点、发病机制与治疗。方法 回顾性分析1998年1月~2005年6月年收治的17例迟发性脑肿胀患者的临床特点和救治情况。结果 所有颅脑损伤患者采用保守治疗后均有好转,但于伤后5-10d出现恶化,CT复查有脑肿胀,经加强综合脱水等治疗后16例治愈,1例死亡。结论 迟发性脑肿胀好发于对冲性额、颞叶挫裂伤伴明显蛛网膜下腔出血、硬膜下薄层血肿及早期CT有脑肿胀者。其发病机制可能与创伤后的迟发性脑血管痉挛、微循环障碍、静脉回流障碍及甘露醇作用下降等因素有关。此类患者病情隐蔽性强,应加强观察、积极行CT复查,如能早期明确诊断,保守治疗多数效果良好。 相似文献
8.
Early postoperative feeding after elective colorectal surgery is not a benefit unique to laparoscopy-assisted procedures 总被引:3,自引:0,他引:3
Previous analyses of non-prospectively randomized trials have suggested that early oral postoperative feeding might be a
benefit unique to laparoscopic surgery. However, some authors have indicated that early feeding can be tolerated by the majority
of patients after elective open surgery. Aim: This prospective randomized study was undertaken to assess whether the time prior to oral intake of food after laparoscopy-assisted
surgery is shorter than that after standard laparotomy. Methods: This trial included 40 patients who were divided randomly into two groups before operation. Group I included 20 patients
(mean age, 52 years; range , 15 – 77 years) who underwent a laparoscopy-assisted colon or rectal procedure (LAP). Group II
consisted of 20 patients (mean age, 56 years, range, 41 – 74 years) who underwent surgery with a standard midline incision
(SMI). On the evening after surgery, patients were allowed clear liquids ab libitum. This regimen was continued until the
first postoperative day at which time they could elect to start eating a regular diet. If a patient had two episodes of vomiting,
a nasogastric tube was inserted. Results: Five laparoscopic procedures were converted to SMI because of adhesions (25%) and an equal number of patients was excluded
from the group that was treated in the traditional manner. Therefore, only 30 patients were included in the analysis. There
were no deaths in this trial. Complications appeared in four of the patients in the LAP group and in two of the patients in
the SMI group (no significant difference). There were no statistically significant differences between the two groups in terms
of the ability to tolerate the early oral intake of food, in the frequency of vomiting or in the incidence of insertion of
a nasogastric tube. The time to the first bowel movement was 5.4 days in LAP and 5.5 days in SMI, and the difference was not
significant. Conclusion: This study invalidates the claim by laparoscopic surgeons that earlier oral intake of food is tolerated by their patients
than by patients who undergo standard procedures.
Accepted: 20 June 1996 相似文献
Résumé. Des études randomisées non prospectives ont suggéré que la reprise précoce de l'alimentation orale peut être un bénéfice particulier à la chirurgie laparoscopique. Certains auteurs ont indiqué que la reprise précoce de l'alimentation orale peut être bien tolérée par la plupart des patients après chirurgie élective ouverte. Cette étude prospective randomisée a été entreprise pour déterminer si la reprise orale de l'alimentation après chirurgie laparoscopique peut être plus précoce qu'après une laparotomie standard. Quarante patients ont été inclus dans cette étude et ont été divisés de manière randomisée en deux groupes avant chirurgie. Le groupe 1 comporte 20 patients (15 à 77 ans, moyenne d'age 52 ans) qui ont subi une résection colique ou rectale laparoscopique (LAP). Le groupe II comporte 20 patients (41 à 74 ans, moyenne d'age 56 ans) qui ont subi une chirurgie par une incision médiane standard (SMI). Le soir de l'intervention chirurgicale, les patients ont été autorisés à boire librement. Ce régime a été continué le premier jour postopératoire à partir duquel les patients pouvaient débuter une alimentation normale. Si un patient présente deux épisodes de vomissements, une sonde naso-gastrique a été mise en place. Cinq interventions laparaoscopiques ont d?être converties en chirurgie ouverte en raison d'adhérences (25%) et un nombre égal de patients ont été exclus du groupe qui a été traité de manière traditionelle. En conséquence, 30 patients ont été inclus dans l'analyse. Aucun décès n'est à déplorer. Quatre complications sont survenues chez des patients du groupe laparoscopique et deux dans le collectif des patients ayant subi un chirurgie ouverte (pas de différence statistique significative). Il n'y a pas de différence statistique significative entre les deux groupes en ce qui concerne la tolérance à la reprise orale de l'alimentation, à la fréquence des vomissements ou à la nécessité de réinsérer un tube naso-gastrique. La première exonération est survenue au 5.4 jour dans le groupe laparoscopique et au 5,5 jour dans le groupe de chirurgie ouverte sans que la différence ne soit significative. En conclusion: Cette étude infirme l'idée que la chirurgie laparoscopique permet une reprise précoce et bien tolérée de l'alimentation en comparaison à la chirrugie ouverte.
Accepted: 20 June 1996 相似文献
9.
C Albet J M Fernandez E Rozman J A Perez A Sacristan J A Ortiz 《Journal of pharmaceutical and biomedical analysis》1992,10(2-3):205-211
A high-performance liquid chromatographic method is developed for the determination of bulk sertaconazole nitrate and related compounds (potential impurities and degradation products) as well as a sertaconazole nitrate cream formulation. A 10-microns Spherisorb CN column is used along with a mobile phase consisting of acetonitrile and aqueous 0.01 M sodium phosphate (37:63, v/v). The sertaconazole nitrate peak is monitored at a wavelength of 260 nm; the retention time being 19.3 min. The detector response for sertaconazole nitrate is linear over the concentration range from 64 to 96 micrograms ml-1. The method is found to be sufficiently selective for the reliable determination of related compounds, FI-7001, FI-7009 and FI-7011, as indicated by same-day and between-day relative standard deviations (RSD) for replicate assays of 1.72% (n = 9) and 2.17% (n = 24), respectively. The application of this method to a cream formulation of sertaconazole nitrate is found to give a mean percentage recovery of 99.4% with RSD of 1.14% (n = 9); none of the cream vehicle peaks are found to interfere with the determination of sertaconazole nitrate. 相似文献
10.
Felipe A. Calvo David Ortiz de Urbina Luis Sierrasesúmaga Oscar Abuchaibe Ignacio Azinovic Federico Antillon Manuel Santos Jos Canadell 《Pediatric blood & cancer》1991,19(6):478-485
From September 1984 to December 1989, 38 patients of pediatric age with localized bone sarcomas received intraoperative radiotherapy (IORT) as part of a multidisci plinary treatment program. The age ranged from 6 to 21 years. The tumor histologies were 22 osteosarcomas and 16 Ewing's sarcomas. Thirty-four had initial primary disease (90%) and 4 were treated for local recurrence (10%). IORT was used on 32 untreated patients and in 6 previously treated with external beam radiotherapy (EBR). The IORT field included the surgically exposed tumor bed area. Single radiation doses ranging from 10 to 20 Gy were delivered, using 6–20 MeV electron beams. The median follow-up time for the entire group is 25 months (2–65+ months). The projected 5-year disease-free and overall survival rates are 65% and 69%, respectively. One patient developed a local recurrence in each histological group: one chondroblastic osteosarcoma and one cervical Ewing's sarcoma. Six patients died from metastatic progression: 3 initially recurrent tumors and three primary disease cases. Severe neuropathy and soft tissue necrosis were seen in some patients as IORT related complications. IORT is a feasible technique to be integrated in multidisciplinary programs that may promote local control in pediatric and adolescent patients with bone sarcomas. Peripheral nerves are dose-limiting tissue structures for IORT. 相似文献