全文获取类型
收费全文 | 8585篇 |
免费 | 603篇 |
国内免费 | 190篇 |
专业分类
耳鼻咽喉 | 34篇 |
儿科学 | 125篇 |
妇产科学 | 56篇 |
基础医学 | 669篇 |
口腔科学 | 177篇 |
临床医学 | 739篇 |
内科学 | 1952篇 |
皮肤病学 | 172篇 |
神经病学 | 302篇 |
特种医学 | 332篇 |
外科学 | 740篇 |
综合类 | 1072篇 |
现状与发展 | 1篇 |
预防医学 | 794篇 |
眼科学 | 38篇 |
药学 | 1352篇 |
2篇 | |
中国医学 | 589篇 |
肿瘤学 | 232篇 |
出版年
2024年 | 14篇 |
2023年 | 117篇 |
2022年 | 506篇 |
2021年 | 595篇 |
2020年 | 276篇 |
2019年 | 257篇 |
2018年 | 246篇 |
2017年 | 287篇 |
2016年 | 317篇 |
2015年 | 342篇 |
2014年 | 501篇 |
2013年 | 665篇 |
2012年 | 436篇 |
2011年 | 520篇 |
2010年 | 410篇 |
2009年 | 384篇 |
2008年 | 405篇 |
2007年 | 362篇 |
2006年 | 315篇 |
2005年 | 293篇 |
2004年 | 215篇 |
2003年 | 201篇 |
2002年 | 216篇 |
2001年 | 137篇 |
2000年 | 97篇 |
1999年 | 115篇 |
1998年 | 105篇 |
1997年 | 100篇 |
1996年 | 96篇 |
1995年 | 97篇 |
1994年 | 89篇 |
1993年 | 43篇 |
1992年 | 78篇 |
1991年 | 67篇 |
1990年 | 47篇 |
1989年 | 58篇 |
1988年 | 33篇 |
1987年 | 42篇 |
1986年 | 41篇 |
1985年 | 54篇 |
1984年 | 36篇 |
1983年 | 29篇 |
1982年 | 24篇 |
1981年 | 24篇 |
1980年 | 21篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1977年 | 14篇 |
1975年 | 7篇 |
1973年 | 4篇 |
排序方式: 共有9378条查询结果,搜索用时 15 毫秒
51.
52.
Jin Deng Maha Balouch Ashley Mooney Christopher Garnet Ducoin Enrico M. Camporesi 《Surgery for obesity and related diseases》2021,17(5):963-967
BackgroundNoninvasive monitoring of partial pressure of carbon dioxide can be accomplished indirectly with capnography (PETCO2) or with transcutaneous carbon dioxide monitoring (PTCCO2). The use of capnography has been shown to offer an advantage over pulse oximetry alone in the early detection of adverse respiratory events when supplemental oxygen is administered. Furthermore, capnography allows for the monitoring of various respiratory measures, including end-tidal carbon dioxide, respiratory rate, tidal volume, and changes in breathing patterns. Transcutaneous CO2 also closely approximates arterial CO2 values, but is not as easy to monitor for prolonged periods. The purpose of this study was to examine the usefulness of capnography and of transcutaneous carbon dioxide monitoring in patients recovering from obesity surgery at high risk of developing postoperative obstructive sleep apnea.MethodsIn a prospective observational study, 64 bariatric surgery patients at risk of developing obstructive sleep apnea were monitored in the postanesthesia care unit (PACU) with either capnography alone (31 patients) or capnography plus transcutaneous carbon dioxide monitoring (33 additional patients) every 3–5 minutes for the duration of their recovery. Primary endpoints included end-tidal and transcutaneous carbon dioxide, peripheral oxygen saturation, respiratory rate, pain scores, and incidence of adverse respiratory events.ResultsAlthough no adverse pulmonary events were observed, capnography detected several patients who experienced short periods of respiratory apnea while maintaining pulse oximetry readings within normal limits. Transcutaneous values were slow to change and averaged 4.5 ± 5.5 mm Hg (P < .05) higher than corresponding end-tidal measurements.ConclusionsThese results indicate the capabilities of both these noninvasive techniques for postoperative monitoring. Capnography acutely monitors changes in respiration, whereas transcutaneous monitoring more accurately reflects arterial CO2 levels. 相似文献
53.
T. A. Sapozhnikova F. S. Zarudii N. Zh. Baschenko S. F. Gabdrahmanova N. S. Makara R. Yu. Khisamutdinova N. A. Ivanova V. S. Nazarov 《Bulletin of experimental biology and medicine》2008,145(2):223-224
Therapeutic administration of 11-deoxymisoprostol had a hepatoprotective effect, which manifested in a decrease in the content
of alanine transaminase and aspartate transaminase in blood plasma, and produced a choleretic effect in rats with CCl4-induced toxic hepatitis.
__________
Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 2, pp. 183–184, February, 2008 相似文献
54.
Laparoscopic resection for a left adrenal black adenoma 总被引:2,自引:0,他引:2
Adrenalblackadenoma (pigmentedadenoma)isquiterare Recently,weperformedalaparoscopicresectionforafunctioningadrenalblackadenoma Wereportthecasehere CASEREPORTA 2 1 year oldfemalewasadmittedtoourhospitalbecauseofamenorrheaandobesity ShepresentedwithtypicalCus… 相似文献
55.
离子交换树脂法与活性炭吸附法提取左旋多巴结果比较 总被引:2,自引:0,他引:2
以水和盐酸为溶剂从猫豆中提取左旋多巴,并对提取液分别用离子交换树脂法和活性炭吸附法富集左旋多巴,再分别用氨水和醇洗脱,经浓缩、精制得左旋多巴。实验结果表明,前法提取周期较长,平均提取率为2.50%,后法提取周期较短,平均提取率为2.66%,提示后法优于前法。 相似文献
56.
57.
伍林生 《重庆医科大学学报》2000,25(Z1):76-78
马克思曾设想俄国农村公社有可能跨越资本主义制度“卡夫丁峡谷”而直接进入共产主义社会。本文运用马克思主义理论辩证地阐述了人类社会实现跨越发展所必备的条件内在因素、外在条件、动力以及跨越的内容。 相似文献
58.
Jonathan P. Purday 《Journal canadien d'anesthésie》1994,41(9):818-844
Monitoring of paediatric anaesthesia has become increasingly more complex in recent years and this is particulary true of
cardiac anaesthesia. The purpose of this review is to give a comprehensive update of published material related to both routine
and specialized cardiac monitoring. Routine monitoring can be particularly affected by the alterations of cardiac rhythm,
blood flow, cardiac output and oxygenation which result from the congenital heart abnormalities themselves, the type of surgery
undertaken and the effects of cardiopulmonary bypass. The use of specialized monitoring is becoming more widespread, particularly
in the areas of cerebral function, mixed venous oxygenation, cardiac output measurement and coagulation. In the last five
years, with the development of smaller probes, a great deal has been published on transoesophageal echocardiography. The use
of the current monitors of cerebral function still remains controversial despite the need for a monitor of adequate brain
perfusion, reflecting the need for a great deal of further research in this area. This review will concentrate on particular
areas which have seen the most profound changes and on monitoring that may form the standards of tomorrow. Finally, amongst
all the technology, it should not be forgotten that the most important clinical monitor is the bedside clinical monitoring
of the physicians themselves.
Depuis quelques années, le monitorage de l’anesthésie pédiatrique devient déplus en plus complexe et tout particulièrement
en anesthésie cardiaque. L’objectif de ce travail consiste à passer en revue la littérature actuelle qui traite du monitorage
usuel et spécialisé. Le monitorage usuel peut être influencé par les modifications de la fréquence cardiaque, du courant sanguin,
du débit cardiaque et de l’oxygénation provoqués par les anomalies cardiaques congénitales, du type de chirurgie et des retentissements
de la circulation extracorporelle. L’utilisation du monitorage spécialisé est de plus en plus répandu et concerne particulièrement
la circulation cérébrale, l’oxygénation du sang veineux mêlé, la mesure du débit cardiaque et la coagulation. Au cours des
cinq dernières années, le développement de sondes plus petites a généré de nombreuses publications sur l’échocardiographie
transoesophagienne. L’utilisation des moniteurs actuels de la fonction cérébrale demeure sujet à controverse bien qu ’un moniteur
de perfusion cérébrale adéquat demeure toujours aussi essentiel, confirmant ainsi le besoin de recherches supplémentaires
sur ce sujet. Ce survol se portera spécialement sur les champs d’activités qui ont connu les changements les plus profonds
et sur le monitorage qui établira les standards du futur. Finalement, au milieu de cette technologie, il ne faut jamais oublier
que le moniteur clinique le plus important se trouve au chevet du malade en la personne du médecin. 相似文献
59.
Bodmeier Roland Wang Hui Dixon David J. Mawson Simon Johnston Keith P. 《Pharmaceutical research》1995,12(8):1211-1217
Purpose. The objective was to prepare polymeric microparticles by atomizing organic polymer solutions into a spray chamber containing compressed CO2 (PCA-process) and to study the influence of various process parameters on their morphological characteristics.
Methods. The swelling of various pharmaceutically acceptable polymers [ethyl cellulose, poly(methyl methacrylate), poly(-caprolactone), poly(dl-lactide), poly(l-lactide) and poly(dl-lactide-glycolide) copolymers] in CO2 was investigated in order to find polymers which did not agglomerate during the spraying process. Poly(l-lactide) (L-PLA) microparticles were prepared by spraying the organic polymer solution into CO2 in a specially designed spraying apparatus. The effect of various process (pressure and temperature of the CO2 phase, flow rate) and formulation (polymer concentration) variables on the morphology and particle size of L-PLA-microparticles was investigated.
Results. Polymers with low glass transition temperatures agglomerated even at low temperatures. The formation of microparticles was favored at moderate temperatures, low polymer concentrations, high pressures and high flow rates of CO2. High polymer concentrations and low flow rates resulted in the formation of polymeric fibers. Colloidal L-PLA particles could also be prepared with this technique in a surfactant-free environment. Initial studies on the microencapsulation of drugs resulted in low encapsulation efficiencies.
Conclusions. The PCA method is a promising technique for the preparation of drug-containing microparticles. Potential advantages of this method include the flexibility of preparing microparticles of different size and morphology, the elimination of surfactants, the minimization of residual organic solvents, low to moderate processing temperatures and the potential for scale-up. 相似文献
60.
Six mainstream and twelve sidestream infrared carbon dioxide (CO2) analysers were tested for accuracy of the CO2 display value, alarm activation and the effects of nitrous oxide (N2O), oxygen (O2) and water vapour according to the ISO Draft International Standard (DIS) #9918. Mainstream analysers (M-type): Novametrix Capnogard 1265; Hewlett Packard HP M1166A (CO2module HP M1016A); Datascope Passport; Marquette Tramscope 12; Nellcor Ultra Cap N-6000; Heilige Vicom-sm SMU 611/612 ETC. Sidestream analysers: Brüel &; Kjaer Type 1304; Datex Capnomac II; Marquette MGA-AS; Datascope Multinex; Ohmeda 4700 OxiCap (all type S1: respiratory cycles not demanded); Biochem BCI 9000; Bruker BCI 9100; Dräger Capnodig and PM 8020; Criticare Poet II; Heilige Vicom-sm SMU 611/612 A-GAS (all type S2: respiratory cycles demanded). The investigations were performed with premixed test gases (2.5, 5, 10 vol%, error ?1% rel.). Humidification (37° C) of gases were generated by a Dräger Aquapor. Respiratory cycles were simulated by manually activated valves. All monitors complied with the tolerated accuracy bias in CO2 reading (≤ 12% or 4 mmHg of actual test gas value) for wet and dry test gases at all concentrations, except that the Marquette MGA-AS exceeded this accuracy limit with wet gases at 5 and 10 vol% CO2. Water condensed in the metal airway adapter of the HP M1166A at 37° C gas temperature but not at 3(P C. The Servomex 2500 (nonclinical reference monitor), Passport (M-type), Multinex (S1-type) and Poet II (S2-type) showed the least bias for dry and wet gases. Nitrous oxide and O2 had practically no effect on the Capnodig and the errors in the others were max. 3.4 mmHg, still within the tolerated bias in the DIS (same as above). The difference between the display reading at alarm activation and the set point was in all monitors (except in the Capnodig: bias 1.75 mmHg at 5 vol% CO2) below the tolerated limit of the DIS (difference ≤ 0.2 vol%). The authors conclude that the tested monitors are safe for clinical use (except those failing the DIS limits). The accuracy of the CO2-reading (average of mean absolute bias) is better in the M-type than in the S1- or S2- type analysers although no statistical (nor clinical) significant differences could be detected. Most manufacturers work with stricter limits than those proposed by the DIS. 相似文献