全文获取类型
收费全文 | 5084篇 |
免费 | 285篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 127篇 |
妇产科学 | 105篇 |
基础医学 | 614篇 |
口腔科学 | 207篇 |
临床医学 | 814篇 |
内科学 | 883篇 |
皮肤病学 | 198篇 |
神经病学 | 486篇 |
特种医学 | 87篇 |
外科学 | 399篇 |
综合类 | 58篇 |
一般理论 | 4篇 |
预防医学 | 688篇 |
眼科学 | 65篇 |
药学 | 250篇 |
中国医学 | 10篇 |
肿瘤学 | 331篇 |
出版年
2023年 | 19篇 |
2022年 | 54篇 |
2021年 | 77篇 |
2020年 | 79篇 |
2019年 | 92篇 |
2018年 | 135篇 |
2017年 | 99篇 |
2016年 | 123篇 |
2015年 | 110篇 |
2014年 | 174篇 |
2013年 | 243篇 |
2012年 | 376篇 |
2011年 | 435篇 |
2010年 | 234篇 |
2009年 | 178篇 |
2008年 | 350篇 |
2007年 | 417篇 |
2006年 | 376篇 |
2005年 | 343篇 |
2004年 | 326篇 |
2003年 | 267篇 |
2002年 | 270篇 |
2001年 | 28篇 |
2000年 | 26篇 |
1999年 | 32篇 |
1998年 | 52篇 |
1997年 | 44篇 |
1996年 | 31篇 |
1995年 | 20篇 |
1994年 | 27篇 |
1993年 | 33篇 |
1992年 | 19篇 |
1991年 | 15篇 |
1990年 | 21篇 |
1989年 | 12篇 |
1988年 | 14篇 |
1987年 | 11篇 |
1986年 | 12篇 |
1985年 | 14篇 |
1984年 | 19篇 |
1983年 | 23篇 |
1982年 | 29篇 |
1981年 | 25篇 |
1980年 | 12篇 |
1979年 | 10篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 5篇 |
排序方式: 共有5376条查询结果,搜索用时 15 毫秒
11.
Magnus M 《Journal of the National Medical Association》2004,96(5):650-656
The purpose of this survey of 528 black men in Miami and Fort Lauderdale, FL, was to assess prostate cancer knowledge among African-American, English-speaking Caribbean, Haitian-American, and African men in America. Knowledge levels were assessed by education, ethnicity, age, income, family history of prostate cancer, and perceived prostate cancer knowledge. Twenty-five barbershops were visited during Fridays, Saturdays, and Sundays over a course of five months. The response rate was 99%. As the black men waited to be seen by their barbers, three interviewers asked them to answer the demographic and knowledge questions. SPSS was used to analyze the data. The main findings were that knowledge levels were adequate, with mean correct responses being 68.4%. Approximately 19.1% of respondents answered 80% of questions correctly, and 7.1% answered 100% of questions correctly. There were no statistically significant differences in knowledge among black men of different ethnicities. There were only two factors which were significantly related to prostate cancer knowledge. Men who earned more than dollars 50,000 and those with a family history of prostate cancer scored significantly higher than lower-income men and men with no family history of prostate cancer. As the percentage of Caribbean-American men and African men in the United States continues to increase, especially in metropolitan centers, those men at highest risk need to be targeted vigorously so that the disproportionate burden of prostate cancer on black men can be relieved. 相似文献
12.
Luiz Alberto Benvenuti MD Maria de Lourdes Higuchi MD Vera Demarchi Aiello MD Marcia Martins Reis 《Cardiovascular pathology》1994,3(4):277-280
The expression of atrial natriuretic peptide (ANP) was analyzed in the atrial and ventricular myocardium in three cases of Pompe's disease (glycogen storage disease of the myocardium), using an immunoperoxidase technique. The cytoplasm of almost all atrial myocytes and some subendocardial myocytes from the right and left ventricles were ANP-positive, excluding the typical central vacuole, which was occupied by glycogen. Ventricular ANP expression was usually more prominent in left ventricular samples, and its distribution was similar to that described in dilated, hypertrophic, restrictive, or ischemic heart disease; however, the enlargement of the myocytes in Pompe's disease is not caused by hypertrophy. We conclude that the atrial myocytes in Pompe's disease maintain ANP expression, despite severe cytoplasmic vacuolization. These results suggest that ventricular ANP expression may be related to mechanical stimuli, such as the increase in wall stress, and not directly related to myocyte hypertrophy. 相似文献
13.
The authors review the literature from human and animal studies on the neurochemical and pathological psychiatric effects of supraphysiological doses of anabolic-androgenic steroids (AAS) and discuss the AAS use and abuse patterns, additional drug use patterns, and personality and behavioral characteristics of AAS abusers. 相似文献
14.
15.
Robert H. Gray Marcia Sokol Roberta K. Brabec Michael J. Brabec 《Experimental and molecular pathology》1981,34(1):72-86
Studies have been undertaken to investigate the role of cellular autophagy in the accommodation of stress in a biological system. Chloroquine (Aralen hydrochloride), an antimalarial and anti-inflammatory drug, was used to induce autophagy in rat liver. A method is presented which uses differential and discontinuous sucrose gradient centrifugation for the preparation of autophagic vacuole-enriched fractions from rat liver. Ultrastructural studies of the autophagic vacuole fractions showed that the integrity of the autophagic vacuoles was maintained throughout the isolation procedure and that they were morphologically similar to those seen in situ. Assay of glucose-6-phosphatase, NADPH-DCIP reductase, and acid phosphatase confirm the presence of membranes derived from the endoplasmic reticulum, as well as lysosomes, in the autophagic vacuole fractions. The distribution of [14C]-chloroquine suggested a preferential binding of the drug to the autophagic vacuoles may have occurred. These results suggest that cellular autophagy may play an important role in the accommodation of chemically induced alterations in hepatocytes by preferentially sequestering chloroquine, as well as restoring cellular ultrastructure. 相似文献
16.
Twelve females were tested at four times during the menstrual cycle with a visual detection task and a visual pattern discrimination task. Mood levels and confidence ratings were evaluated for each session. In addition to the behavioral testing, plasma samples were collected and radioimmunoassayed for estradiol, progesterone, luteinizing hormone, and follicle stimulating hormone levels. Visual detection fluctuated significantly during the menstrual cycle with impaired performance occurring at the premenstrual session. In contrast to previous reports, the impaired performance was not related to lowered confidence ratings or to mood levels. 相似文献
17.
Nascimento Jdos S Giambiagi-deMarval M de Oliveira SS Ceotto H dos Santos KR Bastos Mdo C 《Research in microbiology》2005,156(8):837-842
Among 363 strains of Staphylococcus aureus, 21 were shown to produce bacteriocins (Bac), antimicrobial peptides with potential biotechnological applications. This collection includes strains which are either isolated from food, patients and healthy cattle, or are involved in subclinical bovine mastitis. From these 21 strains, 17 were shown to carry closely-related 8.0-kb Bac plasmids encoding bacteriocins either identical to or similar to aureocin A70, a bacteriocin able to inhibit strains of Listeria monocytogenes, a food-borne pathogen. Such findings prompted us to investigate the genetic relationships among these Bac+ strains. To obtain more discriminatory results, a combined analysis of AP-PCR, rep-PCR, and a modified PCR technique that we designated SD-PCR was employed. The 17 Bac+ strains harboring 8.0-kb Bac plasmids exhibited seven fingerprint patterns. One such genotype was composed of 8 out of the 11 strains associated with bovine mastitis, which suggests the prevalence of a clone of Bac+ strains involved in this animal infection carrying 8.0-kb Bac plasmids. Our data support the assumption that Bac+ strains of S. aureus carrying genetically related 8.0-kb Bac plasmids do not belong to a single clone. It seems, therefore, that 8.0-kb Bac plasmids have spread horizontally among different S. aureus strains. There also seems to be genetic diversity among the remaining Bac+ strains analyzed. 相似文献
18.
Epstein-Barr virus (EBV) is a ubiquitous human gamma-herpesvirus that establishes life-long latency and is associated with lymphoproliferative disorders and the development of several malignancies. EBV infection is frequently, but not always, associated with the development of a syndrome termed infectious mononucleosis. The recent isolation and characterization of a murine gamma-herpesvirus, MHV-68 (gammaHV-68) has provided the first small animal model for studying immunity and pathogenesis of a gamma-herpesvirus in its natural host. MHV-68 has important biological and genetic similarities with the human gamma-herpesviruses. Following intranasal infection of mice with MHV-68, an acute respiratory infection in the lung develops and is cleared, followed by the establishment of latency. Similar to EBV, MHV-68 latency is largely established in B cells, although other cell types can be latently infected. The establishment of latency correlates with a prominent splenomegaly, polyclonal B cell activation with associated autoantibody production, and CD8+ T cell-dominated peripheral blood lymphocytosis, in many aspects mirroring EBV-induced infectious mononucleosis. There are key differences in the MHV-68- and EBV-induced CD8+ T cell responses however. Whereas the expanded CD8+ T cells associated with EBV-induced mononucleosis are largely the outgrowth of T cells responding to lytic viral epitopes elicited during the acute phase of the response, the CD8+ T cell lymphocytosis associated with MHV-68-induced infectious mononucleosis is dominated by an oligoclonal population of T cells expressing Vbeta4+ T cell receptors that are not reactive to acute viral epitopes. The focus of this article will be to highlight the similarities and differences in the infectious mononucleosis syndrome associated with human and murine gamma-herpesviruses. 相似文献
19.
Coon DW Lipman PD Ory MG 《Journal of acquired immune deficiency syndromes (1999)》2003,33(Z2):S194-S205
Social and behavioral HIV/AIDS prevention interventions designed to test their effects on older cohorts are sorely lacking in the scientific literature even though middle-aged and older people represent a significant minority of both existing and new AIDS cases. This article raises key issues relevant in developing and evaluating HIV/AIDS social and behavioral interventions for older cohorts. These interventions must build on our current understanding of behavior change and HIV prevention successes with younger populations while considering important intervention principles gathered from work with older populations in other health arenas. In addition, the authors expand on recent national panels and published reviews relevant to the topic and provide a set of intervention recommendations for use in tandem with these intervention principles. The article also calls for additional research into the sociocultural contexts that influence risk-taking among older cohorts and for the development of interventions at multiple levels. Pragmatic considerations such as identifying and dismantling ageism in interventions, delineating intervention outcomes, and planning for intervention transferability, dissemination, and sustainability also are raised. 相似文献
20.
Ospedal KZ Appel MH Fillus Neto J Mangili OC Sanches Veiga S Gremski W 《International journal of experimental pathology》2002,83(6):287-294
Loxoscelism, the term used to describe envenomation with brown spiders, is characterized by a dermonecrotic lesion at the bite site. In the present investigation we submitted albino rabbits to an acute experimental envenomation protocol using Loxosceles intermedia (brown spider) venom, with in order to determine the pathogenesic features of the lesion induced by this spider, which is the cause of several accidents throughout the world. Rabbits received intradermal injections of the venom and were monitored over the first 4 h, and then at 12 h and 1, 2 and 5 days after envenomation. Histological specimens from 3 rabbits per time point were collected from euthanized animals and processed for histological examination by light microscopy. Major findings observed during the first 4 h were oedema, haemorrhage, degeneration of blood vessel walls, plasma exudation, thrombosis, neutrophil accumulation in and around blood vessels with an intensive diapedesis, a diffuse collection of inflammatory cells (polymorphonuclear leucocytes) in the dermis, and subcutaneous muscular oedema. Over the following hours and up to 5 days after envenomation the changes progressed to massive neutrophil infiltration (with no other leucocytes) into the dermis and even into subcutaneous muscle tissue, destruction of blood vessels, thrombosis, haemorrhage, myonecrosis, and coagulative necrosis on the 5th day. 相似文献