全文获取类型
收费全文 | 9091篇 |
免费 | 590篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 127篇 |
儿科学 | 364篇 |
妇产科学 | 232篇 |
基础医学 | 1194篇 |
口腔科学 | 348篇 |
临床医学 | 617篇 |
内科学 | 2223篇 |
皮肤病学 | 246篇 |
神经病学 | 725篇 |
特种医学 | 394篇 |
外科学 | 1317篇 |
综合类 | 33篇 |
一般理论 | 2篇 |
预防医学 | 738篇 |
眼科学 | 180篇 |
药学 | 444篇 |
中国医学 | 47篇 |
肿瘤学 | 482篇 |
出版年
2023年 | 54篇 |
2022年 | 59篇 |
2021年 | 342篇 |
2020年 | 188篇 |
2019年 | 299篇 |
2018年 | 356篇 |
2017年 | 223篇 |
2016年 | 204篇 |
2015年 | 272篇 |
2014年 | 339篇 |
2013年 | 440篇 |
2012年 | 672篇 |
2011年 | 682篇 |
2010年 | 399篇 |
2009年 | 331篇 |
2008年 | 517篇 |
2007年 | 514篇 |
2006年 | 494篇 |
2005年 | 442篇 |
2004年 | 416篇 |
2003年 | 397篇 |
2002年 | 365篇 |
2001年 | 225篇 |
2000年 | 215篇 |
1999年 | 218篇 |
1998年 | 64篇 |
1997年 | 69篇 |
1996年 | 50篇 |
1995年 | 45篇 |
1994年 | 27篇 |
1993年 | 36篇 |
1992年 | 70篇 |
1991年 | 69篇 |
1990年 | 75篇 |
1989年 | 60篇 |
1988年 | 55篇 |
1987年 | 65篇 |
1986年 | 44篇 |
1985年 | 37篇 |
1984年 | 25篇 |
1983年 | 25篇 |
1982年 | 13篇 |
1981年 | 13篇 |
1979年 | 31篇 |
1977年 | 16篇 |
1976年 | 18篇 |
1974年 | 13篇 |
1973年 | 12篇 |
1972年 | 13篇 |
1967年 | 13篇 |
排序方式: 共有9713条查询结果,搜索用时 156 毫秒
81.
The changes in the content of the catecholamines in each structure of the geniculate and extrageniculate visual system of the rat during the aging period (6-30 months) have been studied. Dopamine was found at lower levels than noradrenaline in all the structures. The dopamine and noradrenaline showed different developmental profiles. Dopamine and its metabolite levels decreased in the lateral geniculate and visual cortex and increased in superior colliculus and posterior thalamus. Noradrenaline and its metabolites increased in all structures during the aging period. However, 3-methoxy-4-hydroxyphenylglycol/noradrenaline and normetanephrine/noradrenaline ratios decreased in all structures except in superior colliculus. These results suggest age-related changes in the catecholamines in the visual system of the rat. 相似文献
82.
Isolated adducted thumbs is an uncommon malformation that occurs sporadically in the majority of cases although some affected families have been reported. Previously, autosomal dominant inheritance was suggested in two familial cases, but this mode of inheritance has not been confirmed. Here we describe a family with adducted thumbs and other digital anomalies in which seven members (six females and one male) are affected in three consecutive generations. Additionally, the patients showed mild abnormalities of fingers 2nd–4th bilaterally and hypoplasia of the middle phalanx of the 5th fingers. This family represents an autosomal dominant condition that apparently has not been previously reported. 相似文献
83.
Cruz-Martínez A Arpa J Santiago S Pérez-Conde C Gutiérrez-Molina M Campos Y 《Electromyography and clinical neurophysiology》2004,44(1):35-38
Conventional EMG, nerve conduction studies and SFEMG were performed in 18 patients with various phenotypes of MD. 14 cases showed findings consistent with mild myopathy, 2 patients signs of sensory-motor axonal neuropathy and 2 cases a mixture of myopathy and axonal neuropathy. Motor unit fiber density was mild increased in 8 out of 13 tested cases. Jitter was abnormal in 10 out of 18 tested patients. Jitter abnormalities were not related to myopathic or neurogenic features in the EMG study, and may be observed in muscles without clinical weakness. The results suggest the existence of neuromuscular transmission disturbances in patients with MD. 相似文献
84.
Miguel A. Rojo-Tirado Pedro J. Benito Jonatan R. Ruiz Francisco B. Ortega Blanca Romero-Moraleda Javier Butragueo Laura M. Bermejo Eliane A. Castro Carmen Gmez-Candela 《Nutrients》2021,13(1)
Studies comparing different types of exercise-based interventions have not shown a consistent effect of training on long-term weight maintenance. The aim of this study was to compare the effects of exercise modalities combined with diet intervention on body composition immediately after intervention and at 3 years’ follow-up in overweight and obese adults. Two-hundred thirty-nine people (107 men) participated in a 6-month diet and exercise-based intervention, split into four randomly assigned groups: strength group (S), endurance group (E), combined strength and endurance group (SE), and control group (C). The body composition measurements took place on the first week before the start of training and after 22 weeks of training. In addition, a third measurement took place 3 years after the intervention period. A significant interaction effect (group × time) (p = 0.017) was observed for the fat mass percentage. It significantly decreased by 5.48 ± 0.65%, 5.30 ± 0.65%, 7.04 ± 0.72%, and 4.86 ± 0.65% at post-intervention for S, E, SE, and C, respectively. Three years after the intervention, the fat mass percentage returned to values similar to the baseline, except for the combined strength and endurance group, where it remained lower than the value at pre-intervention (p < 0.05). However, no significant interaction was discovered for the rest of the studied outcomes, neither at post-intervention nor 3 years later. The combined strength and endurance group was the only group that achieved lower levels of fat mass (%) at both post-intervention and 3 years after intervention, in comparison with the other groups. 相似文献
85.
Asher Y. Rosinger Samantha M. Olson Sascha R. Ellington Janice Perez-Padilla Regina M. Simeone Caitlin S. Pedati Betsy A. Schroeder Gilberto A. Santiago Freddy A. Medina Jorge L. Muoz-Jordn Laura E. Adams Romeo R. Galang Miguel Valencia-Prado Sonia Bakkour Candimar Coln Mary Goodwin Dana Meaney-Delman Jennifer S. Read Lyle R. Petersen Denise J. Jamieson Carmen C. Deseda Margaret A. Honein Brenda Rivera-García Carrie K. Shapiro-Mendoza 《Emerging infectious diseases》2021,27(5):1505
We evaluated nucleic acid amplification testing (NAAT) for Zika virus on whole-blood specimens compared with NAAT on serum and urine specimens among asymptomatic pregnant women during the 2015–2016 Puerto Rico Zika outbreak. Using NAAT, more infections were detected in serum and urine than in whole blood specimens. 相似文献
86.
Brenes Monge Alexander Fernández Elorriaga María Poblano Verástegui Ofelia Valdez Santiago Rosario Martínez Nolasco Manuel A. Yáñez Álvarez Iraís Saturno Hernández Pedro J. 《Maternal and child health journal》2021,25(4):565-573
Maternal and Child Health Journal - To identify and describe the frequency and characteristics of disrespect and abuse practices towards women during facility-based delivery in four hospitals in... 相似文献
87.
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
88.
Carlos Solano Lourdes Vázquez Estela Giménez Rafael de la Cámara Eliseo Albert Montserrat Rovira Ildefonso Espigado Carmen M. Calvo Javier López-Jiménez María Suárez-Lledó Anabella Chinea Albert Esquirol Ariadna Pérez Aránzazu Bermúdez Raquel Saldaña Inmaculada Heras Ana J. González-Huerta Tamara Torrado Guiomar Bautista Montserrat Batlle Santiago Jiménez Carlos Vallejo Pere Barba María Á. Cuesta José L. Piñana David Navarro 《American journal of transplantation》2021,21(1):258-271
The net impact of cytomegalovirus (CMV) DNAemia on overall mortality (OM) and nonrelapse mortality (NRM) following allogeneic hematopoietic stem cell transplantation (allo-HSCT) remains a matter of debate. This was a retrospective, multicenter, noninterventional study finally including 749 patients. CMV DNA monitoring was conducted by real-time polymerase chain reaction (PCR) assays. Clinical outcomes of interest were OM and NRM through day 365 after allo-HSCT. The cumulative incidence of CMV DNAemia in this cohort was 52.6%. A total of 306 out of 382 patients with CMV DNAemia received preemptive antiviral therapy (PET). PET use for CMV DNAemia, but not the occurrence of CMV DNAemia, taken as a qualitative variable, was associated with increased OM and NRM in univariate but not in adjusted models. A subcohort analysis including patients monitored by the COBAS Ampliprep/COBAS Taqman CMV Test showed that OM and NRM were comparable in patients in whom either low or high plasma CMV DNA threshold (<500 vs ≥500 IU/mL) was used for PET initiation. In conclusion, CMV DNAemia was not associated with increased OM and NRM in allo-HSCT recipients. The potential impact of PET use on mortality was not proven but merits further research. 相似文献
89.
Aránzazu Caballero-Marcos Magdalena Salcedo Roberto Alonso-Fernández Manuel Rodríguez-Perálvarez María Olmedo Javier Graus Morales Valentín Cuervas-Mons Alba Cachero Carmelo Loinaz-Segurola Mercedes Iñarrairaegui Lluís Castells Sonia Pascual Carmen Vinaixa-Aunés Rocío González-Grande Alejandra Otero Santiago Tomé Javier Tejedor-Tejada José María Álamo-Martínez Luisa González-Diéguez Flor Nogueras-Lopez Gerardo Blanco-Fernández Gema Muñoz-Bartolo Francisco Javier Bustamante Emilio Fábrega Mario Romero-Cristóbal Rosa Martin-Mateos Julia Del Rio-Izquierdo Ana Arias-Milla Laura Calatayud Alberto A. Marcacuzco-Quinto Víctor Fernández-Alonso Concepción Gómez-Gavara Jordi Colmenero Patricia Muñoz José A. Pons the Spanish Society of Liver Transplantation 《American journal of transplantation》2021,21(8):2876-2884
The protective capacity and duration of humoral immunity after SARS-CoV-2 infection are not yet understood in solid organ transplant recipients. A prospective multicenter study was performed to evaluate the persistence of anti-nucleocapsid IgG antibodies in liver transplant recipients 6 months after coronavirus disease 2019 (COVID-19) resolution. A total of 71 liver transplant recipients were matched with 71 immunocompetent controls by a propensity score including variables with a well-known prognostic impact in COVID-19. Paired case–control serological data were also available in 62 liver transplant patients and 62 controls at month 3 after COVID-19. Liver transplant recipients showed a lower incidence of anti-nucleocapsid IgG antibodies at 3 months (77.4% vs. 100%, p < .001) and at 6 months (63.4% vs. 90.1%, p < .001). Lower levels of antibodies were also observed in liver transplant patients at 3 (p = .001) and 6 months (p < .001) after COVID-19. In transplant patients, female gender (OR = 13.49, 95% CI: 2.17–83.8), a longer interval since transplantation (OR = 1.19, 95% CI: 1.03–1.36), and therapy with renin–angiotensin–aldosterone system inhibitors (OR = 7.11, 95% CI: 1.47–34.50) were independently associated with persistence of antibodies beyond 6 months after COVID-19. Therefore, as compared with immunocompetent patients, liver transplant recipients show a lower prevalence of anti-SARS-CoV-2 antibodies and more pronounced antibody levels decline. 相似文献
90.
M. Djindjian A. Ribeiro E. Ortega A. Gaston J. Poirier 《Surgical and radiologic anatomy : SRA》1988,10(3):201-209
Summary The arterial and venous blood-supply of the intradural filum terminale was studied microscopically in 18 fresh cadavers after removing the dorsolumbar spinal cord in one piece, with the roots and the filum in their dural sheath. The arteries were examined after manual injection of the artery of the lumbar enlargement, while study of the veins was made without injection since their bluish-black color made them easily identifiable. After gross examination, each specimen was fixed and then sectioned at 12 different levels from the medullary conus to the bottom of the dural sac for histologic study. The distribution of the vascularization the filum terminale appeared constant. A single artery, the artery of the filum, arises from the termination of the anterior spinal axis, either by trifurcation or from the proximal part of one of the 2 branches of the anastomotic ansa of the conus. The artery travels in front of the filum, with rapidly diminishing caliber; rarely, it can be followed into the sacral canal. The vein of the filum travels in front of that structure but behind the artery, as in the cord; its caliber is uniform but varies from subject to subject. It traverses the dura below and continuous with the anterior spinal vein above. No vessels were found on the dorsal aspect of the filum. While the artery of the filum is of a caliber proportional to that of the filum and appears to be a nutrient vessel, the vein has a caliber unrelated to that of the filum and appears rather as an intradural drainage route continuous with the anterior spinal vein. Several cases of disease of the filum terminale confirm this anatomic appearance and also show that, because of the existing hyperpressure in the vein of the filum, the posterior spinal vein also shares in the drainage of the latter and that entire system may function in both ascending and descending directions.
La vascularisation normale du filum terminale intradural chez l'homme
Résumé La vascularisation artérielle et veineuse du filum terminale intradural a été étudiée sur 18 cadavres frais, sous microscope, après prélèvement en monobloc de la moelle épinière dorso-lombaire, des racines et du filum dans leur étui dural. L'examen des artères a été fait après injection manuelle de l'artère du renflement lombaire, tandis que l'étude des veines s'est faite sans injection compte tenu d'une coloration bleu-noir spontanée qui les rendent aisément identifiables. Après étude macroscopique, chaque pièce a été fixée, puis coupée à 12 niveaux différents depuis le cône médullaire jusqu'au fond du cul-de-sac dure-mérien, pour étude histologique. La distribution de la vascularisation du FT apparaît constante. Une artère unique, l'artère du FT, naît de la terminaison de l'axe spinal antérieur, soit par trifurcation, soit de la partie proximale d'une des 2 branches de l'anse anastomotique du cône. L'artère chemine devant le FT; son calibre diminue rapidement; rarement, elle a pu être suivie jusque dans le canal sacré. Une veine, la veine du FT, chemine en avant du FT mais en arrière de l'artère, comme au niveau médullaire. Son calibre est uniforme mais variable d'un sujet à l'autre. Elle traverse la dure-mère en bas; elle se continue avec la veine spinale antérieure en haut. Aucun vaisseau n'a été retrouvé à la face dorsale du FT. Si l'artère du FT a un calibre qui est proportionnel à celui du filum et apparaît comme un vaisseau nourricier, la veine a un calibre sans aucun rapport avec le volume de celui-ci et apparaît davantage comme une voie de drainage intradural en continuité avec la veine spinale antérieure. Quelques cas de pathologie du FT confirment cet aspect anatomique et montrent aussi qu'en raison de l'hyperpression veineuse régnant dans la veine du FT, la veine spinale postérieure participe également au drainage de celle-ci et que l'ensemble peut fonctionner dans les 2 sens ascendant ou descendant.相似文献