全文获取类型
收费全文 | 18418篇 |
免费 | 1078篇 |
国内免费 | 107篇 |
专业分类
耳鼻咽喉 | 160篇 |
儿科学 | 474篇 |
妇产科学 | 335篇 |
基础医学 | 2322篇 |
口腔科学 | 517篇 |
临床医学 | 1482篇 |
内科学 | 4623篇 |
皮肤病学 | 454篇 |
神经病学 | 2051篇 |
特种医学 | 739篇 |
外国民族医学 | 3篇 |
外科学 | 2517篇 |
综合类 | 125篇 |
一般理论 | 3篇 |
预防医学 | 860篇 |
眼科学 | 282篇 |
药学 | 1217篇 |
中国医学 | 44篇 |
肿瘤学 | 1395篇 |
出版年
2023年 | 99篇 |
2022年 | 189篇 |
2021年 | 466篇 |
2020年 | 273篇 |
2019年 | 343篇 |
2018年 | 424篇 |
2017年 | 321篇 |
2016年 | 390篇 |
2015年 | 432篇 |
2014年 | 595篇 |
2013年 | 783篇 |
2012年 | 1227篇 |
2011年 | 1226篇 |
2010年 | 710篇 |
2009年 | 601篇 |
2008年 | 1056篇 |
2007年 | 1008篇 |
2006年 | 972篇 |
2005年 | 1041篇 |
2004年 | 927篇 |
2003年 | 784篇 |
2002年 | 707篇 |
2001年 | 509篇 |
2000年 | 516篇 |
1999年 | 428篇 |
1998年 | 156篇 |
1997年 | 143篇 |
1996年 | 150篇 |
1995年 | 132篇 |
1994年 | 132篇 |
1993年 | 98篇 |
1992年 | 319篇 |
1991年 | 261篇 |
1990年 | 250篇 |
1989年 | 202篇 |
1988年 | 179篇 |
1987年 | 162篇 |
1986年 | 171篇 |
1985年 | 157篇 |
1984年 | 121篇 |
1983年 | 79篇 |
1982年 | 54篇 |
1981年 | 59篇 |
1980年 | 47篇 |
1979年 | 90篇 |
1974年 | 50篇 |
1973年 | 50篇 |
1972年 | 68篇 |
1971年 | 48篇 |
1968年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
1.
2.
Del Lama Rafael Silva Candido Raquel Mariana Chiari-Correia Natália Santana Nogueira-Barbosa Marcello Henrique de Azevedo-Marques Paulo Mazzoncini Tinós Renato 《Journal of digital imaging》2022,35(3):446-458
Journal of Digital Imaging - Vertebral Compression Fracture (VCF) occurs when the vertebral body partially collapses under the action of compressive forces. Non-traumatic VCFs can be secondary to... 相似文献
3.
4.
Rocco Spagnuolo Alessandro Corea Mariantonietta Blumetti Alessia Giovinazzo Massimiliano Serafino Caterina Pagliuso Raffaele Pagnotta Grazia Curto Cristina Cosco Vincenzo Cosco Rosellina Margherita Mancina Pietro Garieri Anna Papaleo Laura Grande Anna Barilaro Eugenio Garofalo Andrea Bruni Patrizia Doldo 《Journal of advanced nursing》2020,76(11):2993-3002
5.
Rosario Fernández-Plata Rogelio Pérez-Padilla Rodrigo Del Río-Hidalgo Cecilia García-Sancho Laura Gochicoa-Rangel Christian Rodríguez-Hernández Luis Torre-Bouscoulet David Martínez-Briseño 《Archivos de bronconeumología》2019,55(10):513-518
IntroductionPeople with Down syndrome (DS) have high respiratory morbidity, evaluating their respiratory health with standardized, objective tests is desirable. Thus, the objective of this study was to evaluate the technical quality of Pulmonary Function Tests (PFTs) to determine which ones are most suitable for this population.MethodsParticipants included children, teenagers and adults with DS, 5 years of age or older (n = 302). The technical quality of the impulse oscillometry system (IOS), forced spirometry, lung-diffusing capacity for carbon monoxide (DLCO), and 6-min walk test (6MWT) were analyzed by age group. Capnography and pulse oximetry were included in the study. Technical quality was determined on the basis of current international PFTs standards.ResultsFifty-one percent of participants were males. A total of 184 participants (71%) who completed the IOS fulfilled the quality criteria, while 210 (70%) completed the 6MWT. Performance on forced spirometry and DLCO was poor. All pulse oximetries and 96% percent heart rates obtained had good quality, but exhaled carbon dioxide (PetCO2) and respiratory rate (RR) showed deficient repeatability.ConclusionsIOS appears to be the most reliable instrument for evaluating lung mechanics in individuals with DS. 相似文献
6.
7.
María Cabrerizo Gloria Trallero María José Pena Amaia Cilla Gregoria Megias Carmen Mu?oz-Almagro Eva Del Amo Diana Roda Ana Isabel Mensalvas Antonio Moreno-Docón Juan García-Costa Nuria Rabella Manuel Ome?aca María Pilar Romero Sara Sanbonmatsu-Gámez Mercedes Pérez-Ruiz María José Santos-Mu?oz Cristina Calvo And the study group of “Enterovirus parechovirus infections in children under ?years-old Spain” PI- 《European journal of pediatrics》2015,174(11):1511-1516
8.
9.
Caterina Proto Daniela Romualdi Rosa Maria Cento Rosario S Spada Giuseppina Di Mento Raffaele Ferri Antonio Lanzone 《Gynecological endocrinology》2006,22(4):213-218
BACKGROUND: In the central nervous system, several neuropeptides are believed to be involved in the pathophysiology of Alzheimer's disease (AD). Indeed, previous studies have documented that glucagon-like peptide 1 (GLP-1) possesses neurotropic properties and can reduce amyloid-beta peptide levels in the brain in vivo. Moreover, the concentrations of neuropeptide Y (NPY) seem to be altered in the cerebrospinal fluid of patients with AD and in subjects with major depression. Finally, among the modifications induced by aging, a dysregulation of the ghrelin-growth hormone (GH) system has been reported. METHODS: We investigated the plasma concentrations of these neuropeptides in 14 subjects with AD. Data obtained from these patients were compared with data from an age- and weight-matched healthy group. RESULTS: No significant differences were found between the two groups in relation to plasma levels of GLP-1, NPY, ghrelin and GH. Peripheral NPY concentrations were positively correlated with ghrelin levels in both groups, and with plasma GLP-1 concentration only in controls. CONCLUSION: On the basis of our results, peripheral levels of these neuropeptides seem not to serve as biochemical markers of AD. 相似文献
10.
Monolateral hypoplasia of the motor vagal nuclei in a case of sudden infant death syndrome 总被引:1,自引:1,他引:0
Veronica Macchi Rossella Snenghi Raffaele De Caro Anna Parenti 《Journal of anatomy》2002,200(2):195-198
During the development of motor vagal nuclei (MVN), the neuroblasts of the myeloencephalic basal plate migrate in the dorsolateral direction to form the dorsal motor vagal nucleus (DMVN) and ventrolaterally to form the ventral motor vagal nucleus (VMVN). Those neuroblasts that remain close to the median sulcus will form the hypoglossal nucleus. In support of the congenital origin of the alteration of the MVN in sudden infant death syndrome (SIDS), we report the case of an 8‐month‐old female child who was found dead in her cot. The neuropathological assessment revealed that the medullary triangle of the 4th ventricle floor was asymmetric, owing to the presence of three prominences to the left side of the median sulcus. The medial prominence corresponded to the hypoglossal nucleus, which showed a marked increase in the number of large neurons; the intermediate prominence corresponded to the DMVN whose large neurons were reduced and were recognizable mainly at the level of the medial fringe; the lateral prominence corresponded to the solitary nucleus. The left solitary tract showed a reduction of the transverse diameter. Also, the left VMVN showed marked reduction in the number of neurons. Inflammatory and astrocytic reactions were absent. We suggest that in SIDS cases the hypocellularity of the MVN and the increased number of neurons of the hypoglossal nucleus are intimately related, indicating a congenital alteration due to incomplete migration of the vagal neuroblasts with abnormality of the autonomic cardio‐respiratory control. 相似文献