全文获取类型
收费全文 | 3708篇 |
免费 | 135篇 |
国内免费 | 33篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 45篇 |
妇产科学 | 79篇 |
基础医学 | 505篇 |
口腔科学 | 48篇 |
临床医学 | 392篇 |
内科学 | 796篇 |
皮肤病学 | 16篇 |
神经病学 | 409篇 |
特种医学 | 113篇 |
外科学 | 618篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 251篇 |
眼科学 | 26篇 |
药学 | 293篇 |
中国医学 | 2篇 |
肿瘤学 | 248篇 |
出版年
2023年 | 17篇 |
2022年 | 35篇 |
2021年 | 65篇 |
2020年 | 39篇 |
2019年 | 51篇 |
2018年 | 82篇 |
2017年 | 33篇 |
2016年 | 61篇 |
2015年 | 71篇 |
2014年 | 112篇 |
2013年 | 183篇 |
2012年 | 247篇 |
2011年 | 285篇 |
2010年 | 136篇 |
2009年 | 143篇 |
2008年 | 264篇 |
2007年 | 268篇 |
2006年 | 263篇 |
2005年 | 236篇 |
2004年 | 245篇 |
2003年 | 226篇 |
2002年 | 246篇 |
2001年 | 44篇 |
2000年 | 36篇 |
1999年 | 49篇 |
1998年 | 55篇 |
1997年 | 52篇 |
1996年 | 28篇 |
1995年 | 36篇 |
1994年 | 31篇 |
1993年 | 16篇 |
1992年 | 22篇 |
1991年 | 13篇 |
1990年 | 16篇 |
1989年 | 21篇 |
1988年 | 12篇 |
1987年 | 15篇 |
1986年 | 22篇 |
1985年 | 12篇 |
1984年 | 14篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 6篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1970年 | 3篇 |
1967年 | 4篇 |
1963年 | 3篇 |
排序方式: 共有3876条查询结果,搜索用时 15 毫秒
31.
Filali-Zegzouti Y Abdelmelek H Rouanet JL Cottet-Emard JM Pequignot JM Barré H 《Pflügers Archiv : European journal of physiology》2000,441(2-3):275-280
Physiological studies have shown that glucagon is a potential mediator of nonshivering thermogenesis (NST) in birds. The present work was undertaken in order to investigate whether the observed thermogenesis results from a direct action of glucagon on avian thermoregulatory mechanisms or in fact requires the participation of other agents such as catecholamines. Our experiments were performed using cold-acclimated (CA) ducklings which developed muscle NST. A comparison was made with thermoneutral (TN) ducklings of the same age. Our principal results showed that: (1) at ambient temperature (25 degrees C), circulating norepinephrine (NE) was markedly decreased in CA ducklings (-42%), while circulating epinephrine (E) did not undergo any consistent change; (2) in CA and TN ducklings, an intraperitoneal injection of glucagon (360 microg x kg(-1)) was followed after 10 min by prominent lipolysis and a large increase in circulating NE (4- to 6-fold) and E (14- to 17-fold), which was sustained for at least 1 h. The elevation of circulating NE was less pronounced in CA ducklings. The thermogenic action of glucagon in birds is probably indirect and involves at least the mobilization of lipids and sympatho-adrenal stimulation. The changes in peripheral noradrenergic activity during cold acclimation could be associated with adaptive changes leading to NST. 相似文献
32.
Frdric Bonfils Jean-Marc Fabre Louis Giral Claude Montginoul Aumduth Mungroo Ren Sagnes Franois Schu 《Macromolecular chemistry and physics.》1989,190(11):2759-2771
In order to study the influence of the nature of the moiety bearing a tetrathiafulvalenyl group in the polymers upon the microlithographic properties of resists, poly(p-chloromethylstyrene)s and poly(styrene-co-p-chloromethylstyrene)s containing the 4-tetrathiafulvalenylphenoxymethyl group with a variety of controlled molecular weights and molecular weight distributions were studied. The copolymers were all prepared by reaction of poly(4-vinylbenzyl chloride) with potassium 4-tetrathiafulvalenylphenolate ( 3 ). Without exception, the resulting poly[p-chloromethylstyrene-co-p-(tetrathiafulvalenylphenoxymethyl)styrene]s are highly insoluble. However, by reaction of potassium 4-tetrathiafulvalenylphenolate with poly(styrene-co-p-chloromethylstyrene) soluble copolymers could be prepared. 相似文献
33.
Genetic polymorphism of cytomegalovirus strains responsible of congenital infections 总被引:1,自引:0,他引:1
Picone O Costa JM Ville Y Chaix ML Rouzioux C Leruez-Ville M 《Pathologie-biologie》2004,52(9):534-539
OBJECTIVES: Congenital Cytomegalovirus (CMV) infection is the main cause of neurological handicap in young children. The objective for studying genetic polymorphism of strains responsible for congenital infection is to identify CMV strains or groups of strains which would be more frequent in this context and/or which would be responsible for more severe congenital infection. METHODS: In this paper, we report and analyze the literature concerning the genetic polymorphism of CMV strains responsible of congenital infection, in the genes coding for the envelop protein B and the non structural UL144 protein and in the CMV short tandem repeats. RESULTS AND CONCLUSION: All UL144 and gB genotypes can be vertically transmitted from mothers to fetuses, none of these studies has shown any link between the genotypes and the severity of congenital disease. Moreover, no link between short tandem repeats polymorphism and severity of congenital disease has been demonstrated. However, short tandem repeats analysis may be a powerful tool to study the epidemiology of CMV congenital infections. 相似文献
34.
Effects of carotid sinus nerve transection on changes in neuropeptide Y and indolamines induced by long-term hypoxia in rats 总被引:1,自引:0,他引:1
Ludovic Poncet L. Denoroy Yvette Dalmaz Jean-Marc Pequignot 《Pflügers Archiv : European journal of physiology》1998,437(1):130-138
Long-term hypoxia induces changes in neuropeptide-Y-like immunoreactivity (NPY-LI) and/or in the content of serotonin (5-HT)
and its metabolite 5-hydroxyindoleacetic acid (5-HIAA) at the central level. To determine whether these alterations depend
on the integrity of carotid body (CB) chemoreceptors, intact rats or those whose carotid sinus nerve was transected (CSNT)
were exposed to hypoxia (10% O2) or to normoxia for 14 days. Thereafter, NPY-LI, 5-HT and 5-HIAA levels in discrete brain regions were determined. The increase
in NPY-LI in the ventrolateral medulla oblongata (VLM) of intact hypoxic rats was mostly abolished after CSNT and therefore
is mainly mediated by CB chemoreceptors. In contrast, other hypoxia-induced changes were similar or even enhanced in CSNT
as compared to intact rats and therefore do not depend on the integrity of CB chemoreceptors. This was the case for the increase
of NPY-LI in the striatum and the caudal dorsomedian medulla oblongata (DMM), as well as for all the changes in 5-HT and 5-HIAA
in the DMM, the VLM, the raphe nuclei, the striatum and the frontal cortex. We propose that long-term hypoxia alters brain
NPY-LI and indolamine content through the stimulation of CB chemoreceptors or ancillary chemoreceptors, as well as through
local biochemical or morphological mechanisms.
Received: 5 May 1998 / Received after revision: 27 July 1998 / Accepted: 3 September 1998 相似文献
35.
Behavioral and neurochemical effects induced by subchronic combined exposure to toluene at 40 ppm and noise at 80 dB-A in rats 总被引:1,自引:0,他引:1
We investigated whether exposure to noise, in addition to its well-known potentiating effect on toluene-induced ototoxicity, may also exacerbate behavioral disturbances and brain neurochemical alterations produced by subchronic exposure to low toluene concentration. To test this hypothesis, we evaluated whether subchronic combined exposure (16 weeks, 104 h per week) to noise at 80 dB-A and toluene at 40 ppm potentiates the recently reported neurotoxic effects of subchronic exposure to 40 ppm toluene. Locomotor and rearing activities, sensitization to narcosis induced by acute toluene at high concentration, and tyrosine and tryptophan hydroxylase activities in the caudate-putamen and hippocampus were investigated in both male and female rats. Our results confirm that subchronic exposure to 40 ppm toluene significantly decreases rearing activity and leads to a sensitization to toluene-induced narcosis, as evaluated by loss of righting reflex, but fails to demonstrate any adverse effect of noise, alone or in combination with toluene. Given that toluene has addictive properties, the lack of potentiating behavioral and neurochemical effect of noise is discussed with regards to a recent study that has shown that methamphetamine neurotoxicity is potentiated by exposure to loud noise. 相似文献
36.
Buser Julie M. Boyd Carol J. Moyer Cheryl A. Zulu Davy Ngoma-Hazemba Alice Jones Andrew D. Lori Jody R. 《Maternal and child health journal》2021,25(8):1182-1186
Maternal and Child Health Journal - Low birthweight (LBW) is a significant public health problem in sub-Saharan Africa and LBW in rural Zambia is high. Our study explored the prevalence of LBW for... 相似文献
37.
Giuliante Felice Viganò Luca De Rose Agostino M. Mirza Darius F. Lapointe Réal Kaiser Gernot Barroso Eduardo Ferrero Alessandro Isoniemi Helena Lopez-Ben Santiago Popescu Irinel Ouellet Jean-Francois Hubert Catherine Regimbeau Jean-Marc Lin Jen-Kou Skipenko Oleg G. Ardito Francesco Adam René 《Annals of surgical oncology》2021,28(13):8198-8208
Annals of Surgical Oncology - The liver-first approach in patients with synchronous colorectal liver metastases (CRLM) has gained wide consensus but its role is still to be clarified. We aimed to... 相似文献
38.
39.
Gianfranco Donatelli Andrea Spota Fabrizio Cereatti Stefano Granieri Ibrahim Dagher Renaud Chiche Jean-Marc Catheline Guillaume Pourcher Lionel Rebibo Daniela Calabrese Simon Msika Carmelisa Dammaro Hadrien Tranchart Panagiotis Lainas Thierry Tuszynski Filippo Pacini Roberto Arienzo Jean-Marc Chevallier Jean-Loup Dumont 《Surgery for obesity and related diseases》2021,17(8):1432-1439
BackgroundEndoscopy plays a pivotal role in the management of adverse events (AE) following bariatric surgery. Leaks, fistulae, and post-operative collection after sleeve gastrectomy (SG) may occur in up to 10% of cases.ObjectivesTo evaluate the efficacy and safety of endoscopic internal drainage (EID) for the management of leak, fistula, and collection following SG.SettingRetrospective, observational, single center study on patients referred from several bariatric surgery departments to an endoscopic referral center.MethodsEID was used as first-line treatment for the management of leaks, fistulae, and collections. Leaks and fistulae were treated with double pigtail stent (DPS) deployment in order to guarantee internal drainage and second intention cavity obliteration. Collections were treated with endoscropic ultrasound (EUS)–guided deployment of DPS or lumen apposing metal stents.ResultsA total of 617 patients (83.3% female; mean age, 43.1 yr) were enrolled in the study for leak (n = 300, 48.6%), fistula (n = 285, 46.2%), and collection (n = 32, 5.2%). Median follow-up was 19.5 months. Overall clinical success was 84.7% whereas 15.3% of cases required revisional surgery after EID failure. Clinical success according to type of AE was 89.5%, 78.5%, and 90% for leak, fistula, and collection, respectively. A total of 10 of 547 (1.8%) presented a recurrence during follow-up. A total of 28 (4.5%) AE related to the endoscopic treatment occurred. At univariate logistic regression predictors of failure were: fistula (OR 2.012), combined endoscopic approach (OR 2.319), need for emergency surgery (OR 1.755), and previous endoscopic treatment (OR 4.818).ConclusionEarly EID for the management of leak, fistula, and post-operative collection after SG seems a safe and effective first-line approach with good long-term results. 相似文献
40.
Davy C. H. Cheng Frances Chung Kenneth R. Chapman Jack Romanelli 《Journal canadien d'anesthésie》1990,37(5):521-527
This randomized double-blind study compared the effects of: (1) saline infusion (C); (2) sufentanil alone (1.0 micrograms.kg-1) (S); and (3) low-dose sufentanil (0.5 micrograms.kg-1) in combination with lidocaine (1.5 mg.kg-1) (LS): on the cardiovascular responses to tracheal intubation and on postoperative ventilation as monitored by respiratory inductive plethysmography in day-care surgical procedures of approximately 60 min duration. Thirty healthy, unpremedicated patients were studied. Thiopentone requirements were reduced by 40 and 28 per cent in the S and LS groups respectively compared with control (P less than 0.001). Both treatments suppressed HR and BP responses (P less than 0.005) to intubation. Postoperatively, PaCO2 was elevated (P less than 0.05) in group S. Dose-related respiratory depression was observed. The incidence of postoperative apnoea was significantly higher in both S and LS groups than compared with control (P less than 0.05). However, only patients in group S showed higher apnoea index and mean apnoea duration over the initial 10-20 min after surgery compared with control (P less than 0.005). In addition, group S showed slower respiratory frequency and prolonged expiratory time (P less than 0.005). In conclusion, an induction dose of sufentanil (1 microgram.kg-1) used in balanced anaesthesia of less than 70 min duration was associated with significant respiratory depression, particularly during the initial 10-20 min after surgery, whereas low-dose sufentanil (0.5 micrograms.kg-1) with lidocaine (1.5 mg.kg-1) had minimal postoperative respiratory depression and comparable attenuation of pressor responses to intubation. 相似文献