全文获取类型
收费全文 | 7484篇 |
免费 | 486篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 210篇 |
妇产科学 | 190篇 |
基础医学 | 965篇 |
口腔科学 | 377篇 |
临床医学 | 585篇 |
内科学 | 1842篇 |
皮肤病学 | 180篇 |
神经病学 | 505篇 |
特种医学 | 348篇 |
外科学 | 887篇 |
综合类 | 47篇 |
一般理论 | 3篇 |
预防医学 | 623篇 |
眼科学 | 106篇 |
药学 | 544篇 |
中国医学 | 41篇 |
肿瘤学 | 420篇 |
出版年
2023年 | 43篇 |
2022年 | 137篇 |
2021年 | 226篇 |
2020年 | 139篇 |
2019年 | 221篇 |
2018年 | 272篇 |
2017年 | 176篇 |
2016年 | 215篇 |
2015年 | 249篇 |
2014年 | 314篇 |
2013年 | 367篇 |
2012年 | 519篇 |
2011年 | 514篇 |
2010年 | 295篇 |
2009年 | 277篇 |
2008年 | 398篇 |
2007年 | 384篇 |
2006年 | 322篇 |
2005年 | 306篇 |
2004年 | 272篇 |
2003年 | 259篇 |
2002年 | 223篇 |
2001年 | 195篇 |
2000年 | 178篇 |
1999年 | 177篇 |
1998年 | 87篇 |
1997年 | 84篇 |
1996年 | 59篇 |
1995年 | 53篇 |
1994年 | 41篇 |
1993年 | 40篇 |
1992年 | 81篇 |
1991年 | 82篇 |
1990年 | 82篇 |
1989年 | 48篇 |
1988年 | 42篇 |
1987年 | 63篇 |
1986年 | 49篇 |
1985年 | 60篇 |
1984年 | 41篇 |
1983年 | 39篇 |
1981年 | 20篇 |
1980年 | 23篇 |
1979年 | 40篇 |
1978年 | 23篇 |
1977年 | 22篇 |
1975年 | 25篇 |
1974年 | 27篇 |
1973年 | 26篇 |
1969年 | 23篇 |
排序方式: 共有8005条查询结果,搜索用时 20 毫秒
51.
Andr Luca Araujo de Sousa Wanderson Carvalho de Almeida Jean de Pinho Mendes Victor Angelo Martins Montalli Antonione Santos Bezerra Pinto 《Acta stomatologica Croatica》2022,56(2):176
The Melanotic Neuroectodermal Tumor of Infancy (MNTI) is an asymptomatic, pigmented neoplasm characterized by a fast and locally aggressive growth along with a rare tissue formation. In the diagnostic process, the use of imaging exams can suggest a local destruction suggestive of malignancy, a sign of bone remodeling and expansion. Therefore, as any early diagnosis minimizes risks and improves the prognosis of treatment for the patient, the aim of this study was, based on a clinical case report, to corroborate the use of histopathological analysis associated with immunohistochemistry. Thus, we conclude that the immunohistochemical exam is of great importance for a better complementation of the MNTI diagnosis process. In addition, it can reveal signs of possible aggressive growth. 相似文献
52.
53.
Food labels are the first information tool used by consumers in the purchase and consumption of food products. Food labeling is a tool that can influence the consumers’ perception of quality and, in turn, their food choice. This study characterizes and demonstrates the importance of labeling and the degree of consumers’ perception and literacy about food labels through the application of an online questionnaire. The results obtained, in a sample of n = 467, showed that Portuguese consumers have the habit of reading the label and recognizing its importance but do not understand all the information contained in the label. They have an easier time understanding the front-of-pack labeling systems, especially those presented through symbols/colors. Thus, it demonstrates the need for greater education and literacy in the areas of food and nutrition so that through the reading and interpretation of labels, consumers can make informed food choices. 相似文献
54.
55.
56.
Danielle Barbosa Morais Tarcizio Antônio Rêgo de Paula Karine Moura de Freitas Sérgio Luis Pinto da Matta 《亚太生殖杂志》2012,1(4):303-307
ObjectiveTo describe the seminiferous epithelium cycle (SEC) by tubular morphology method, and the acrosomal development of individualizing spermatids, and to explore the distinction of the stages between two generations of spermatids.MethodsTesticular fragments were fixed in Karnovsky, embedded in glycol methacrylate and examined under light microscopy and transmission electron microscopy. Sections in 3 μm thickness were stained with toluidine blue for the characterization of the stages of the SEC by the tubular morphology method, or submitted to the PAS reaction for the visualization of the acrosomal formation. Additional details on the acrosomal formation were observed under transmission electron microscopy.ResultsThrough the eight stages described by tubular morphology method, 10 steps of acrosomal formation were observed in the spermatid development, called acrosomal steps. As the spermatids were produced in stage V of the tubular morphology method, it was at this stage from which began the steps of acrosomal development.ConclusionsWe propose association of the acrosomal steps for the first time, with the different stages by tubular morphology method. This method presents an alternative to the existent Methods, allowing interspecific comparisons of the SEC, not only among different species of bats, but also among the other mammals. 相似文献
57.
58.
Gustavo Leporace Jomilto Praxedes Glauber Ribeiro Pereira Sérgio Medeiros Pinto Daniel Chagas Leonardo Metsavaht Flávio Chame Luiz Alberto Batista 《Physical Therapy in Sport》2013,14(1):35-43
ObjectiveTo examine the influence of a preventative training program (PTP) on sagittal plane kinematics during different landing tasks and vertical jump height (VJH) in males.DesignSix weeks prospective exercise intervention.ParticipantsFifteen male volleyball athletes (13 ± 0.7 years, 1.70 ± 0.12 m, 60 ± 12 kg).InterventionsPTP consisting of plyometric, balance and core stability exercises three times per week for six weeks. Bilateral vertical jumps with double leg (DL) and single leg (SL) landings were performed to measure the effects of training.Main outcome measurementsKinematics of the knee and hip before and after training and VJH attained during both tasks after training. The hypothesis was that the PTP would produce improvements in VJH, but would not generate great changes in biomechanical behavior.ResultsThe only change identified for the SL was the longest duration of landing, which represents the time spent from initial ground contact to maximum knee flexion, after training, while increased angular displacement of the knee was observed during DL. The training did not significantly alter the VJH in either the SL (difference: 2.7 cm) or the DL conditions (difference: 3.5 cm).ConclusionsDespite the PTP’s effectiveness in inducing some changes in kinematics, the changes were specific for each task, which highlights the importance of the specificity and individuality in selecting prevention injury exercises. Despite the absence of significant increases in the VJH, the absolute differences after training showed increases corroborating with the findings of statistically powerful studies that compared the results with control groups. The results suggest that short-term PTPs in low risk young male volleyball athletes may enhance performance and induce changes in some kinematic parameters. 相似文献
59.
Milena de Paiva Cavalcanti Filipe Dantas-Torres Suênia da Cunha Gonçalves de Albuquerque Rayana Carla Silva de Morais Maria Edileuza Felinto de Brito Domenico Otranto Sinval Pinto Brandão-Filho 《Molecular and cellular probes》2013,27(3-4):122-128
American cutaneous leishmaniasis (ACL) caused by Leishmania (Viannia) braziliensis is a neglected disease of humans in the New World that may also cause irreversible skin and eventually mucocutaneous lesions. This parasite can also infect dogs and represents a diagnostic challenge for veterinarians. Methods currently available for the diagnosis of ACL have a low sensitivity and may be time-consuming, representing a limit for treatment expedition of ACL. Quantitative real time PCR assays (qPCR) for the detection of L. (V.) braziliensis in canine blood samples were developed herein, and the detection limit and specificity of different molecular targets (kDNA and rDNA) evaluated. Of the protocols assessed, two qPCR assays, one targeting the kDNA and other the SSU rDNA of L. (V.) braziliensis, performed better, with detection limits of 100 fg and 10 pg, respectively. These assays were also used to test skin samples from humans with suspected ACL. The results indicate that the qPCR protocols developed represent an advance for the diagnosis of ACL in dogs and humans from this region, and provide a rapid and non-invasive diagnosis of the infection by L. (V.) braziliensis. Considering the quantitative nature of the assays, they will also be useful for monitoring treatment efficacy and preventing relapses in human patients in Brazil, although further studies are needed to critically evaluate the specificity of the qPCRs for their capacity to distinguish different Leishmania species and subspecies (represented by zymodemes) in other countries. Finally, molecular assays established may represent new tools for future basic and applied research focused on species identification, host–parasite associations, and infection dynamics in host and vector populations. 相似文献