全文获取类型
收费全文 | 11359篇 |
免费 | 622篇 |
国内免费 | 40篇 |
专业分类
耳鼻咽喉 | 217篇 |
儿科学 | 372篇 |
妇产科学 | 206篇 |
基础医学 | 1328篇 |
口腔科学 | 313篇 |
临床医学 | 729篇 |
内科学 | 2941篇 |
皮肤病学 | 353篇 |
神经病学 | 741篇 |
特种医学 | 237篇 |
外国民族医学 | 1篇 |
外科学 | 1789篇 |
综合类 | 121篇 |
一般理论 | 4篇 |
预防医学 | 822篇 |
眼科学 | 299篇 |
药学 | 830篇 |
中国医学 | 50篇 |
肿瘤学 | 668篇 |
出版年
2023年 | 60篇 |
2022年 | 105篇 |
2021年 | 319篇 |
2020年 | 165篇 |
2019年 | 313篇 |
2018年 | 471篇 |
2017年 | 264篇 |
2016年 | 262篇 |
2015年 | 270篇 |
2014年 | 362篇 |
2013年 | 498篇 |
2012年 | 826篇 |
2011年 | 913篇 |
2010年 | 431篇 |
2009年 | 362篇 |
2008年 | 745篇 |
2007年 | 752篇 |
2006年 | 762篇 |
2005年 | 695篇 |
2004年 | 635篇 |
2003年 | 570篇 |
2002年 | 530篇 |
2001年 | 184篇 |
2000年 | 199篇 |
1999年 | 187篇 |
1998年 | 60篇 |
1997年 | 46篇 |
1996年 | 54篇 |
1995年 | 48篇 |
1994年 | 38篇 |
1993年 | 22篇 |
1992年 | 66篇 |
1991年 | 58篇 |
1990年 | 55篇 |
1989年 | 52篇 |
1988年 | 45篇 |
1987年 | 59篇 |
1986年 | 51篇 |
1985年 | 44篇 |
1984年 | 38篇 |
1983年 | 43篇 |
1982年 | 31篇 |
1981年 | 27篇 |
1980年 | 20篇 |
1979年 | 31篇 |
1978年 | 22篇 |
1977年 | 19篇 |
1975年 | 17篇 |
1974年 | 33篇 |
1973年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
R Maxwell R López M E Furuya J C Ramírez U Beltrán J Sandoval E Lupi Herrera 《Archivos del Instituto de Cardiología de México》1988,58(2):89-93
In order to establish an animal model of pulmonary vasoconstriction we followed the time course of intrapulmonary shunt (Qs/Qt) in a canine model of lobar atelectasis with closed chest. Ten mongrel dogs were studied. Bronchial occlusion of the right lower lobe (RLL) was performed by inflating the balloon of a Foley catheter placed through a rigid bronchoscopy. Analysis of variance was used for statistical analysis. (15 minutes) After occlusion Qs/Qt reached its maximum increasing from 8.2 +/- 3.6 to 29.7 +/- 11.7% (p less than 0.05) and PaO2 decreased from 357 +/- 49 to 100 +/- 43 mm Hg (p less than 0.05). Afterwards, there was a progressive decline of Qs/QT accompanied by an also progressive increase in PaO2. At the end of the experiment (3 hrs post atelectasis) Qs/Qt was 11.2 +/- 4.9 and PaO2 251 +/- 124 mm Hg (p less than 0.05). Pulmonary vascular resistance increased post atelectasis from 439 +/- 168 to 598 +/- 256 d.s.cm-5 (p less than 0.05). Complete atelectasis of the RLL was confirmed postmortem. As the changes in Qs/Qt and PaO2 did not parallel the change in cardiac output we conclude that the mechanism of decrease in Qs/Qt was hypoxic vasoconstriction. 相似文献
33.
Alfredo Avellaneda Fernández álvaro Pérez Martín Maravillas Izquierdo Martínez Mar Arruti Bustillo Francisco Javier Barbado Hernández Javier de la Cruz Labrado Rafael Díaz-Delgado Pe?as Eduardo Gutiérrez Rivas Cecilia Palacín Delgado José Ramón Ramón Giménez Javier Rivera Redondo 《Atencion primaria / Sociedad Espa?ola de Medicina de Familia y Comunitaria》2009,41(10):e1-e5
34.
Jonathan D Schiff Michelle L Ramírez Natan Bar-Chama 《Endocrinology & Metabolism Clinics of North America》2007,36(2):313-331
Male infertility is the result of a variety of highly treatable conditions. The critical step in treating male infertility is to evaluate properly every male partner of an infertile couple and to generate the proper treatment strategy. There are many medical and surgical options that can help most couples overcome male factor infertility. Male infertility can most easily be broken down into problems of sperm production (testicular dysfunction) and problems of sperm transport (obstruction). When applicable, medical therapies are used as an initial strategy to improve sperm production or as a preliminary therapy to boost production transiently in anticipation of a surgical sperm retrieval attempt. A range of surgical options is available to correct varicoceles, reconstruct the obstructed system, or retrieve sperm for assisted reproduction. 相似文献
35.
Experience in the management of myelomeningocele in Puerto Rico 总被引:1,自引:0,他引:1
The medical records of 128 children with myelomeningocele who were treated at the Pediatric University Hospital, Puerto Rico Medical Center, from January, 1980, to July, 1985, were reviewed retrospectively. The medical and surgical management during the first hospitalization of these children was studied in detail for predefined parameters. The average age at the time of myelomeningocele repair was 6.6 days. Statistical analysis showed that repair of the myelomeningocele defect before 48 hours of age did not reduce the occurrence of ventriculitis. The incidence of ventriculitis secondary to the management of the myelomeningocele lesion was 12.5%. Complications after repair of the myelomeningocele (including skin flap necrosis, cerebrospinal fluid leaks, and wound infection) were present in 43.8% of the patients who developed ventriculitis and in 19.0% of those who did not. This observation is statistically significant (p = 0.03) and indicates that complications of healing after myelomeningocele repair represent the most significant risk factor for the development of ventriculitis. 相似文献
36.
37.
Interobserver variability in neonatal cranial ultrasonography 总被引:1,自引:0,他引:1
Jennifer Pinto Nigel Paneth Elias Kazam Ram Kairam Sylvan Wallenstein Walter Rose David Rosenfeld Steven Schonfeld Irving Stein Thomas Witomski 《Paediatric and perinatal epidemiology》1988,2(1):43-58
The reliability of cranial ultrasound diagnosis in the premature neonate was examined using data from an ongoing multicentre study of the epidemiology and long-term consequences of neonatal brain haemorrhage. First week ultrasound films (obtained at 4 hours, 24 hours and 7 days) from 60 study subjects were randomly selected for independent review by two groups of experienced interpreters, and results were recorded separately for observations (i.e. presence or absence of an abnormal echodense area on a film) and interpretations (i.e. presence or absence of haemorrhage or ventricular dilatation) in each hemisphere. Because of deaths in the first week of life, the total number of films examined was 138. Concordance on the presence or absence of an abnormal echodensity was examined for each individual film for three areas of interest: the germinal matrix, the ventricles and the parenchyma. Concordance on the presence or absence of haemorrhage or ventricular dilatation was examined only for the seventh-day film, or the final film prior to death. Finally, concordance was analysed with the diagnostic interpretations grouped into categories thought to differ prognostically for long-term outcome. In general, concordance was poorest for germinal matrix lesions and best for parenchymal lesions. Concordance was lower for observations made on each individual film than it was for interpretation of the final film in each case. Fifty-five of 60 cases (92%) were assigned to the same major prognostic category by both readers. Ultrasound review conferences were held periodically and there was evidence that concordance in ultrasound reading and interpretation improved during the course of the study. 相似文献
38.
Fangli Chen Margaret Barkett Kavitha T. Ram Adrian Quintanilla Iswar K. Hariharan 《Proceedings of the National Academy of Sciences of the United States of America》1997,94(23):12485-12490
The activity of Ras family proteins is modulated in vivo by the function of GTPase activating proteins, which increase their intrinsic rate of GTP hydrolysis. We have isolated cDNAs encoding a GAP for the Drosophila Rap1 GTPase. Drosophila Rapgap1 encodes an 850-amino acid protein with a central region that displays substantial sequence similarity to human RapGAP. This domain, when expressed in Escherichia coli, potently stimulates Rap1 GTPase activity in vitro. Unlike Rap1, which is ubiquitously expressed, Rapgap1 expression is highly restricted. Rapgap1 is expressed at high levels in the developing photoreceptor cells and in the optic lobe. Rapgap1 mRNA is also localized in the pole plasm in an oskar-dependent manner. Although mutations that completely abolish Rapgap1 function display no obvious phenotypic abnormalities, overexpression of Rapgap1 induces a rough eye phenotype that is exacerbated by reducing Rap1 gene dosage. Thus, Rapgap1 can function as a negative regulator of Rap1-mediated signaling in vivo. 相似文献
39.
40.
J M Tejerina Lobo J V Bagan Sebastián J Ramón Mu?iz 《Avances en Odontoestomatología》1989,5(5):263-267
Infection of the oral mucous membrane is frequent in patients with removable prostheses, either totally of partially, and particularly when the prostheses is palatal. The principal etiological factor causing the infection is accepted to be "Candidas" aided by the presence of plaque bacteria (in patients with poor oral hygiene care), and a poor fit of the prostheses to the soft tissues. Treatment of the infection must proceed in the following order: a) use of effective medication against oral fungus such as Nystatin or Ketoconazole. b) Meticulous oral hygiene care in the mucous membrane as well as in the prostheses, but using the prostheses as little as possible during the treatment period. c) A total cure of the infection (denture stomatitis) before proceeding to the next phase of the treatment. d) Determination of the adjustment and occlusion of the prostheses in order to determine those areas of the prostheses which need to be refilled because of maladjustment of the prostheses to the soft tissues of the patient. 相似文献