全文获取类型
收费全文 | 32604篇 |
免费 | 3093篇 |
国内免费 | 179篇 |
专业分类
耳鼻咽喉 | 352篇 |
儿科学 | 1187篇 |
妇产科学 | 829篇 |
基础医学 | 4263篇 |
口腔科学 | 1191篇 |
临床医学 | 3335篇 |
内科学 | 6939篇 |
皮肤病学 | 871篇 |
神经病学 | 3193篇 |
特种医学 | 793篇 |
外科学 | 3642篇 |
综合类 | 361篇 |
一般理论 | 41篇 |
预防医学 | 3561篇 |
眼科学 | 512篇 |
药学 | 2032篇 |
1篇 | |
中国医学 | 86篇 |
肿瘤学 | 2687篇 |
出版年
2024年 | 24篇 |
2023年 | 419篇 |
2022年 | 784篇 |
2021年 | 1670篇 |
2020年 | 1091篇 |
2019年 | 1523篇 |
2018年 | 1657篇 |
2017年 | 1266篇 |
2016年 | 1387篇 |
2015年 | 1366篇 |
2014年 | 1760篇 |
2013年 | 2146篇 |
2012年 | 2778篇 |
2011年 | 2908篇 |
2010年 | 1620篇 |
2009年 | 1287篇 |
2008年 | 1826篇 |
2007年 | 1733篇 |
2006年 | 1592篇 |
2005年 | 1442篇 |
2004年 | 1252篇 |
2003年 | 1048篇 |
2002年 | 902篇 |
2001年 | 264篇 |
2000年 | 219篇 |
1999年 | 208篇 |
1998年 | 162篇 |
1997年 | 138篇 |
1996年 | 119篇 |
1995年 | 114篇 |
1994年 | 75篇 |
1993年 | 84篇 |
1992年 | 77篇 |
1991年 | 62篇 |
1990年 | 57篇 |
1989年 | 59篇 |
1988年 | 83篇 |
1987年 | 78篇 |
1986年 | 67篇 |
1985年 | 56篇 |
1984年 | 66篇 |
1983年 | 34篇 |
1982年 | 38篇 |
1981年 | 48篇 |
1980年 | 28篇 |
1979年 | 24篇 |
1978年 | 20篇 |
1977年 | 22篇 |
1975年 | 20篇 |
1974年 | 18篇 |
排序方式: 共有10000条查询结果,搜索用时 812 毫秒
81.
A detailed study comparing the distribution of D2 receptors and tyrosine hydroxylase-immunoreactive fibers in the hippocampus and parahippocampal cortices of the rat, cat, and human was conducted. The distribution of [125I]epidepride binding to D2 receptors along the transverse and longitudinal axes of the hippocampus and parahippocampus differed among the species. In rat hippocampus, the number of sites was highest in septal portions of lacunosum-moleculare of CA1 and stratum moleculare of the subiculum. Virtually no binding to D2 receptors existed in the temporal hippocamps. For the cat hippocampus, the highest binding existed in the inner one-third of the molecular layer of the dentate gyrus (DG). There were also significant numbers of D2 receptors in strata radiatum and oriens of the CA subfields, with almost undetectable levels in lacunosum moleculare and subiculum. The number of sites was higher in the septal than temporal hippocampus. In the human hippocampus, highest binding was observed in the molecular layer of DG and the subiculum, with lower levels in strata oriens and lacunosum-moleculare of CA3, and very low binding in CA1. The histochemical demonstration of the pattern of mossy fibers revealed an organization complementary to that of D2 receptors in cat and human. In none of the species was there significant expression of D2 receptors in the entorhinal cortex, except in the caudal extreme of this region in the rat. In that region a trilaminar pattern was exhibited that continued into the perirhinal cortex. A trilaminar pattern of D2 receptor expression was observed in the perirhinal cortex of all species, with the highest values in the external and deep laminae and low expression in the middle laminae. The organization of dopamine fibers was assessed by comparing the distribution of tyrosine hydroxylase-positive and dopamine β-hydroxylase-immunoreactive fibers in these same regions. It revealed consistent mismatches between the pattern of D2 receptor expression and dopaminergic innervation in all three species. The implications for this mismatch are discussed. It is hypothesized that the distribution of D2 receptors, and not of dopamine fibers, determines what neural systems dopamine influences in the hippocampal complex. © 1994 Wiley-Liss, Inc. 相似文献
82.
83.
Promoting autonomy and independence for older people within nursing practice: a literature review 总被引:1,自引:0,他引:1
Sue Davies Bsc Msc RGN RHV Sara Laker BA RGN Lorraine Ellis BA MSc RGN RNT 《Journal of advanced nursing》1997,26(2):408-417
The principles of promoting autonomy and independence underpin many approaches to improving the quality of nursing care for older people in whatever setting, and are in line with wider developments in health care such as the Patient's Charter. However, these concepts require careful definition if nursing practices which might promote autonomy and independence are to be identified. Although the generalizability of the research-based literature in this field is limited by a focus upon older people in continuing-care settings, a review of the literature found a number of indicators associated with attempts to promote patient autonomy and independence. These were grouped into the following categories: systems of care delivery which promote comprehensive individualized assessment and multidisciplinary care planning; attempts to encourage patients/clients to participate in decisions about their care; patterns of communication which avoid exerting power and control over patients/clients and attempts to modify the environment to promote independence and minimize risk. It is suggested that the review identifies a number of principles for nursing practice which can be applied in a range of care settings in order to promote the autonomy and independence of older people. 相似文献
84.
85.
The effect of testosterone and anabolic steroids on the size of sebaceous glands was studied by means of interactive morphometry in skin biopsies of power athletes. The subjects used self-administered high doses of testosterone and anabolic steroids during a 4-week strength training period. After 4 weeks' use of hormones, the area of sectioned sebaceous glands enlarged significantly by a factor of 89.2% (p less than 0.005). The number of cells in the so-called differentiating cell pool (DCP) and in the undifferentiated cell pool (UCP) also increased significantly (p less than 0.025, p less than 0.05, respectively). The size of the area occupied by UCP cells increased significantly (p less than 0.05). The study suggests that high doses of testosterone and anabolic steroids lead to an enlargement of sebaceous glands in male power athletes. 相似文献
86.
Some prostatic cancers (T4) spread out along the ureters to the kidneys. Patients, usually arrive with terminal renal failure and bladder retention and have often fast-advancing cancer with massive nodes invading. T.U.R., reimplantation of the ureters into the bladder dome or into a pso?c bladder and the specific treatment of the cancer, have often permitted these patients to survive for some years without any dialysis. In these cases we often find very important lower limbs oedema. With lymphatic nodes radiotherapy and subcutaneous injections of heparin, these oedema may regress completely. 相似文献
87.
Antonio Amoroso Pierluigi Garzia Marta Vadacca Sara Galluzzo Flavia Del Porto Anna P Mitterhofer Antonella Afeltra 《The Journal of adolescent health》2003,32(1):94-97
We report on a 26-year-old female affected by Noonan syndrome (NS), a congenital disorder characterized by various phenotypic features and congenital anomalies) associated with a variety of autoimmune diseases, including systemic lupus erythematosus, celiac disease, and Hashimoto thyroiditis. Autoimmunity is seldom described in NS and the association between this congenital disease and three autoimmune disorders has not been previously reported. Should the occurrence of autoimmune disorders in NS be confirmed, a relevant clinical and laboratory evaluation of NS patients should be performed in order to clarify whether the immune system involvement represents only an occasional event or is a feature of the disease. 相似文献
88.
A. Koşar K. Sarica B. Küpeli G. Alçiğir O. Süzer S. Küpeli 《International urology and nephrology》1997,29(3):351-356
Infertility may occur in patients with unilateral testicular torsion whose contralateral testis is intact. Depending on this
observation, the physicians have begun to examine the contralateral testis.
In the present prospective study we aimed to examine the histopathologic alterations occurring in the contralateral testicle
with time. Sixty adult male albino rats were included in the programme, and following experimental torsion the histopathologic
findings, especially those in the contralateral testis, were evaluated after 4–12 weeks. Long-term and high degree torsion
of the testicle led to varying degrees of deterioration in the germinal epithelium and interstitial cells of the contralateral
testicle. Histopathologic alterations were reversed in 12 weeks. Tubular diameter and testicular volume also decreased in
accordance with the histopathologic alteration.
In our opinion, orchiectomy following torsion of one testicle will limit potential histopathologic alterations in the contralateral
testicle. 相似文献
89.
Changes in the content of the opiate peptide Met-enkephalin at the early stages of immune response are studied in different
structures of rats brain 20 min and 24 h after immunization with sheep erythrocytes.
Translated fromByulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 123, No. 2, pp. 170–172, February, 1997 相似文献
90.
Michael Steinitz Alejandro Livoff Sara Tamir Talma Brenner 《Medical oncology (Northwood, London, England)》1993,10(1-2):49-52
A universal method for selection of surface marker-positive cells is described. The cells, admixed with an excess of surface marker-negative cells, are In-st labelled with a specific biotinylated ligand and then isolated with the aid of monoclonal, anti-biotin coated beads. The method enables selection and isolation of cells with a frequency as low as 10-4. The ligand can be an antigen (for selection of infrequent antibody-producing cells), an antibody (for selection of surface antigen-positive cells) or other molecules (for selection of specific receptor-positive cells). 相似文献