全文获取类型
收费全文 | 91081篇 |
免费 | 7749篇 |
国内免费 | 4950篇 |
专业分类
耳鼻咽喉 | 827篇 |
儿科学 | 1568篇 |
妇产科学 | 1212篇 |
基础医学 | 11155篇 |
口腔科学 | 1369篇 |
临床医学 | 12475篇 |
内科学 | 14216篇 |
皮肤病学 | 1096篇 |
神经病学 | 6187篇 |
特种医学 | 2979篇 |
外国民族医学 | 34篇 |
外科学 | 9520篇 |
综合类 | 11341篇 |
现状与发展 | 16篇 |
一般理论 | 42篇 |
预防医学 | 7889篇 |
眼科学 | 2285篇 |
药学 | 8419篇 |
54篇 | |
中国医学 | 3354篇 |
肿瘤学 | 7742篇 |
出版年
2024年 | 244篇 |
2023年 | 1326篇 |
2022年 | 3078篇 |
2021年 | 4198篇 |
2020年 | 3086篇 |
2019年 | 2924篇 |
2018年 | 3200篇 |
2017年 | 2691篇 |
2016年 | 2638篇 |
2015年 | 3802篇 |
2014年 | 4747篇 |
2013年 | 4642篇 |
2012年 | 7162篇 |
2011年 | 7766篇 |
2010年 | 4733篇 |
2009年 | 3648篇 |
2008年 | 5070篇 |
2007年 | 5320篇 |
2006年 | 5050篇 |
2005年 | 5046篇 |
2004年 | 3645篇 |
2003年 | 3357篇 |
2002年 | 2997篇 |
2001年 | 1519篇 |
2000年 | 1687篇 |
1999年 | 1754篇 |
1998年 | 1296篇 |
1997年 | 1185篇 |
1996年 | 891篇 |
1995年 | 817篇 |
1994年 | 784篇 |
1993年 | 489篇 |
1992年 | 521篇 |
1991年 | 466篇 |
1990年 | 398篇 |
1989年 | 340篇 |
1988年 | 247篇 |
1987年 | 245篇 |
1986年 | 192篇 |
1985年 | 133篇 |
1984年 | 95篇 |
1983年 | 73篇 |
1982年 | 70篇 |
1981年 | 50篇 |
1980年 | 26篇 |
1979年 | 36篇 |
1977年 | 13篇 |
1976年 | 15篇 |
1975年 | 12篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 1 毫秒
1.
2.
3.
4.
Tony R Cucuzzella Elva G Delport Nancy Kim Julie Marley Christine Pruitt Anton G Delport 《The spine journal》2006,6(4):364-369
BACKGROUND CONTEXT: Substantial variation exists regarding the use of sedation before interventional spine techniques. Patient preference should play an important role in decision making regarding the need for sedation. However, little is known about patients' anxiety levels before spinal injections and their perceptions about the necessity of sedation. PURPOSE: To determine patient perception for need for sedation before epidural steroid injections and zygapophyseal joint injections. STUDY DESIGN/SETTING: Survey of consecutive spinal injection patients in an outpatient spine center. PATIENT SAMPLE: 500 consecutive lumbar, thoracic, and cervical patients receiving spinal injections. OUTCOME MEASURES: A 12-item questionnaire assessing patients' perceived anxiety before to a spinal injection. METHODS: Subjects were given the questionnaire after their spinal injection. Percentages requesting sedation for a first and potential second procedure were assessed. Additionally, anxiety level and pain rating, location of injection, age, sex, and other medication use were analyzed to determine the effect on the request for sedation. RESULTS: 17% of patients questioned requested sedation before an injection, and 28% would request sedation if they were to have a second injection. CONCLUSIONS: Routine sedation before diagnostic and therapeutic injections is not necessary as the majority of patients would not request sedation before the procedure when given the option. However, in some patients sedation is indicated, and all patients would benefit from educational material on sedation before the injection. 相似文献
5.
Xin Mei Jiang Akio Ohnishi Tatsunori Yamamoto Yoshiyuki Murai Akira Awaya Masato Ikeda 《Acta neuropathologica》1995,90(2):130-134
One of the pyrimidine compounds, 2-piperadino-6-methyl-5-oxo-5,6-dihydro(7H)pyrrolo[3,4-d]pyrimidine (MS-818), has neurotropic effects in vitro. Therefore, we studied the effect of MS-818 on the regeneration of the peroneal nerve in C57BL/6J mice after a crush injury. Two test groups, which received a daily intraperitoneal injection of 5 mg/kg or 10 mg/kg MS-818, respectively, were compared with controls, which received daily intraperitoneal injections of physiological saline, over a 14-day period. The maximum foot-width ratio (crushed side/uncrushed side) was obtained on days 1, 8 and 14 after the crush injury, and the various morphometric parameters were evaluated at both 5 and 10 mm distal to the proximal portion of the crush site. The significant effects of MS-818 included a larger maximum foot width (P<0.04) and a greater number of unmyelinated axons per nerve at both levels (P<0.003) in both test groups than in controls. MS-818 had no significant effects on body weight, the increase of total transverse fascicular area after the crush injury, the total number of myelinated fibers with their size distributions, or the number of nuclei of Schwann cells and macrophages. Therefore, we conclude that MS-818 promotes axonal sprouting and elongation after a crush injury in mice. 相似文献
6.
J. de Pedro-Cuesta V. Abraira G.-X. Jiang G. Solders S. Fredrikson 《Acta neurologica Scandinavica》1996,93(2-3):175-183
Using hierarchical cluster analysis, applied to 47 cases of Guillain-Barre Syndrome (GBS) incident in South-West Stockholm (SWS) during the period from January 1973 to June 1992, we identified three major clinicoepidemiological subgroups. The first subgroup, 25.5% of the cases (26.7 ± 6.7 years), recorded a peak incidence at ages 20–29 years and presented significant differences from other subgroups, a high proportion of cases with onset at low age preceded by respiratory infection (83.3%) and with normal motor conduction velocity (50.0%). Also found, were less affected biological parameters, a rapidly progressive course and independence in gait at one month after onset. A second subgroup, 27.7% of cases, was severely affected, clinically and functionally. It consisted predominantly of young individuals (22.7 ± 11.1 years), with a high incidence (69.2% of cases) in autumn. A third subgroup, comprising 40.47; of cases, was older (61.1 ± 11.0 years) and, in general, also severely affected. The incidence of this form appeared to be invariant with time. 相似文献
7.
OBJECTIVE: To understand the role of nasal mucous epithelial cells to hypoxia in early stage of nasal polyps(NP) formation. METHODS: Epithelial cells of NP and inferior turbinate (IT) were cultured without serum under normal oxygen and hypoxia, and stimulus of inflammatory cytokines. Erythropoietin (EPO) was regarded as hypoxia mark, and expression of vascular endothelial growth factor(VEGF) mRNA and protein derived from epithelial cells were detected respectively by in situ hybridization and ELISA. RESULTS: 1. Under hypoxia, EPO mRNA was expressed intensely in epithelial cells from NP and IT, and there was no significant difference between both of them. This result suggested that EPO might be regarded as a hypoxic mark. 2. The ability of producing VEGF mRNA increased with cytokines stimulation, especially under hypoxia. Protein level of VEGF from epithelial cells of NP and IT increased with cytokines stimulation, especially in hypoxia and was time-dependent. CONCLUSION: Epithelial cells actively produce vast VEGF under hypoxia. The VEGF induced by hypoxia of the mucosa in middle meatus is of importance in the formation of nasal polyps(NP) in early stage, which may be the major cause of NP formation in middle meatus. 相似文献
8.
Rodica Pop-Busui Jiang Lu Neuza Lopes Teresa L. Z. Jones and the BARI D Investigators 《Journal of the peripheral nervous system : JPNS》2009,14(1):1-13
Abstract We evaluated the associations between glycemic therapies and prevalence of diabetic peripheral neuropathy (DPN) at baseline among participants in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial on medical and revascularization therapies for coronary artery disease (CAD) and on insulin-sensitizing vs. insulin-providing treatments for diabetes. A total of 2,368 patients with type 2 diabetes and CAD was evaluated. DPN was defined as clinical examination score >2 using the Michigan Neuropathy Screening Instrument (MNSI). DPN odds ratios across different groups of glycemic therapy were evaluated by multiple logistic regression adjusted for multiple covariates including age, sex, hemoglobin A1c (HbA1c), and diabetes duration. Fifty-one percent of BARI 2D subjects with valid baseline characteristics and MNSI scores had DPN. After adjusting for all variables, use of insulin was significantly associated with DPN (OR = 1.57, 95% CI: 1.15–2.13). Patients on sulfonylurea (SU) or combination of SU/metformin (Met)/thiazolidinediones (TZD) had marginally higher rates of DPN than the Met/TZD group. This cross-sectional study in a cohort of patients with type 2 diabetes and CAD showed association of insulin use with higher DPN prevalence, independent of disease duration, glycemic control, and other characteristics. The causality between a glycemic control strategy and DPN cannot be evaluated in this cross-sectional study, but continued assessment of DPN and randomized therapies in BARI 2D trial may provide further explanations on the development of DPN. 相似文献
9.
Jing‐Ping Zhang Limin Zheng Jiang‐Hai Wang Karl‐Eric Magnusson Xin Liu 《Phytotherapy research : PTR》2009,23(6):844-850
Ganoderma sinensis has been used widely in Oriental countries for the prevention and treatment of various diseases including cancer. Previous studies have shown that the lipid extract from Ganoderma exhibits direct cytotoxicity against tumor cells. Here, it is reported that the lipid extract from germinating G. sinensis spores, at lower concentrations that have no direct tumoricidal activity, induce potent antitumor immune responses in human monocytes/macrophages. Upon stimulation with the lipid extract, monocytes/macrophages exhibited markedly increased production of proinflammatory cytokines and surface expression of costimulatory molecules. Conditioned medium from stimulated cells effectively suppressed the growth of tumor cells. Apparently, the lipid extract triggered macrophage activation via a mechanism different from that associated with LPS. Moreover, it was observed that the lipid extract could partially re‐establish the antitumor activity of the immunosuppressive tumor‐associated macrophages. These results indicated that in addition to its direct tumoricidal activity, the lipid extract from G. sinensis spores could exert antitumor activity by stimulating the activation of human monocytes/macrophages. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
10.
Julie M Aultman 《Medical education》2009,43(11):1107-1107