全文获取类型
收费全文 | 18283篇 |
免费 | 1474篇 |
国内免费 | 38篇 |
专业分类
耳鼻咽喉 | 129篇 |
儿科学 | 704篇 |
妇产科学 | 523篇 |
基础医学 | 2379篇 |
口腔科学 | 229篇 |
临床医学 | 2053篇 |
内科学 | 3469篇 |
皮肤病学 | 305篇 |
神经病学 | 1971篇 |
特种医学 | 298篇 |
外国民族医学 | 5篇 |
外科学 | 1957篇 |
综合类 | 163篇 |
一般理论 | 67篇 |
预防医学 | 2749篇 |
眼科学 | 264篇 |
药学 | 1144篇 |
1篇 | |
中国医学 | 38篇 |
肿瘤学 | 1347篇 |
出版年
2024年 | 43篇 |
2023年 | 286篇 |
2022年 | 485篇 |
2021年 | 919篇 |
2020年 | 553篇 |
2019年 | 759篇 |
2018年 | 861篇 |
2017年 | 614篇 |
2016年 | 630篇 |
2015年 | 697篇 |
2014年 | 905篇 |
2013年 | 1158篇 |
2012年 | 1602篇 |
2011年 | 1617篇 |
2010年 | 828篇 |
2009年 | 666篇 |
2008年 | 1140篇 |
2007年 | 1203篇 |
2006年 | 967篇 |
2005年 | 905篇 |
2004年 | 816篇 |
2003年 | 727篇 |
2002年 | 540篇 |
2001年 | 74篇 |
2000年 | 64篇 |
1999年 | 65篇 |
1998年 | 112篇 |
1997年 | 75篇 |
1996年 | 39篇 |
1995年 | 50篇 |
1994年 | 41篇 |
1993年 | 39篇 |
1992年 | 30篇 |
1991年 | 21篇 |
1990年 | 21篇 |
1989年 | 20篇 |
1987年 | 11篇 |
1986年 | 21篇 |
1985年 | 18篇 |
1984年 | 21篇 |
1983年 | 8篇 |
1982年 | 13篇 |
1981年 | 15篇 |
1980年 | 14篇 |
1978年 | 6篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1961年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
52.
Sinonasal surfactant protein A1, A2, and D gene expression in cystic fibrosis: a preliminary report. 总被引:1,自引:0,他引:1
Bradford A Woodworth Rachel Wood John E Baatz Rodney J Schlosser 《Otolaryngology--head and neck surgery》2007,137(1):34-38
OBJECTIVE: To measure alterations in SPA1, A2, and D gene expression in various forms of inflammatory chronic rhinosinusitis (CRS). STUDY DESIGN AND SETTING: Sinus mucosal biopsies were performed in patients with allergic fungal rhinosinusitis (AFS), CRS with nasal polyposis, cystic fibrosis (CF), and controls. SP mRNA was measured with quantitative polymerase chain reaction. RESULTS: Patients with CF (n = 4) showed significantly increased SPA1 (82-fold), SPA2 (100-fold), and SPD (47-fold) mRNA (P < 0.05) when compared with controls (n = 5). Patients with CRS with nasal polyposis (n = 5) also demonstrated elevated SPA1 (27-fold), SPA2 (13-fold), and SPD (13-fold). Patients with AFS (n = 7) had increased SPA1 (5-fold), SPA2 (9-fold), and SPD (17-fold), but were not statistically significant. CONCLUSION: SPA1, A2, and D are upregulated in various forms of CRS, but are significantly elevated in cystic fibrosis CRS. SIGNIFICANCE: Understanding the role of SPs in CRS will help develop novel treatment approaches for sinonasal pathoses. 相似文献
53.
Kathryn E Merkel Karen L Schmidt Rachel M Levenstein Jessie M VanSwearingen Barbara C Bentley 《Otolaryngology--head and neck surgery》2007,137(1):100-104
OBJECTIVES: Positive affect in individuals with a facial movement disorder may promote lip corner movement (zygomaticus major) during smiling. We investigated whether a positive affect marker (orbicularis oculi activity) observed in an initial clinic visit of individuals with facial movement disorder (N = 28) predicted increased lip corner movement at a subsequent visit. STUDY DESIGN AND SETTING: In this clinical outcomes study, lip corner movement was assessed with the use of automated facial analysis. Asymmetry of movement was compared in individuals who smiled with or without the positive affect marker at an initial clinic visit. RESULTS: The positive affect marker at the initial visit was associated with a reduction in the asymmetry of the lip corner movement at the second visit. CONCLUSION: Positive affect predicts improved facial movement outcomes in patients with facial movement disorders. SIGNIFICANCE: Positive emotion in facial movement patients may be an important factor in recovery of facial movement during therapy. 相似文献
54.
55.
The additive benefit of hypnosis and cognitive-behavioral therapy in treating acute stress disorder 总被引:3,自引:0,他引:3
Bryant RA Moulds ML Guthrie RM Nixon RD 《Journal of consulting and clinical psychology》2005,73(2):334-340
This research represents the first controlled treatment study of hypnosis and cognitive- behavioral therapy (CBT) of acute stress disorder (ASD). Civilian trauma survivors (N=87) who met criteria for ASD were randomly allocated to 6 sessions of CBT, CBT combined with hypnosis (CBT-hypnosis), or supportive counseling (SC). CBT comprised exposure, cognitive restructuring, and anxiety management. CBT-hypnosis comprised the CBT components with each imaginal exposure preceded by a hypnotic induction and suggestions to engage fully in the exposure. In terms of treatment completers (n=69), fewer participants in the CBT and CBT-hypnosis groups met criteria for posttraumatic stress disorder at posttreatment and 6-month follow-up than those in the SC group. CBT-hypnosis resulted in greater reduction in reexperiencing symptoms at posttreatment than CBT. These findings suggest that hypnosis may have use in facilitating the treatment effects of CBT for posttraumatic stress. 相似文献
56.
OBJECTIVE: To examine the prevalence and correlates of self-reported urogenital symptoms (dryness, irritation or itching, discharge, dysuria) among postmenopausal women aged 50-79. DESIGN: A cross-sectional analysis based on n=98,705 women enrolled in the US-based Women's Health Initiative observational study and clinical trials. Urogenital symptoms, symptom severity (mild, moderate, severe), and all covariates were self-reported through questionnaires at enrollment. Prevalence rates of each urogenital symptom were examined and logistic regression was used to identify potential correlates. RESULTS: Prevalence rates for each symptom were: dryness, 27.0%; irritation or itching, 18.6%; discharge, 11.1%; and dysuria, 5.2%. Four factors were correlated with two or more symptoms: Hispanic ethnicity (adjusted odds ratio (AOR)=2.1-3.1 versus white women across all symptoms), obesity (AOR=2.2 severe discharge versus none, AOR=3.6 severe irritation/itching versus none), treated diabetes (pills or shots) compared to no diabetes (AOR=2.4 severe dysuria versus none, AOR=3.2 severe irritation/itching versus none), and vaginal cream HRT/ERT compared to those who never used HRT/ERT (AOR=4.4 severe dryness versus none, AOR=4.6 severe irritation/itching versus none). Factors not associated with the symptoms included sexual activity, age, years since menopause, current smoking, marital status, gravidity, and natural versus surgical menopause. CONCLUSIONS: This is the first report to document urogenital symptoms by race/ethnicity among an exclusively postmenopausal population. We found an elevated prevalence of urogenital symptoms among women who are Hispanic, obese, and/or diabetic. Confirmation of our findings in these subgroups, and, if confirmed, analysis on why these populations are at greater risk, are areas for future research. 相似文献
57.
Hepatocyte proliferation is the possible mechanism for the transient decrease in liver injury during steatosis stage of alcoholic liver disease 总被引:2,自引:0,他引:2
Steatosis is a frequent pathologic stage in alcoholic liver disease (ALD). Although the mechanisms for increased susceptibility of steatotic liver to injury have been postulated, the ability of these hepatocytes to proliferate and withstand injury is unknown. There are conflicting reports on the status of hepatocyte regeneration following chronic alcohol ingestion. Hence, the objective of this study was to investigate the temporal dynamics between the pattern of liver injury and hepatocyte proliferation during the steatosis stage of ALD. Alcoholic steatosis was induced in male Sprague-Dawley rats by feeding an ethanol (EtOH)-containing Lieber-DeCarli liquid diet for a period of 5 weeks. Microvesicular steatosis was evident in H&E sections by three weeks in the EtOH-treated rats, which further developed into panlobular macrovesicular steatosis by 5 weeks. Plasma transaminase activities indicated progressive increase in liver injury peaking at 3 weeks with significant but mild decrease at 4 and 5 weeks. CYP2E1 protein and activity was significantly increased in EtOH-fed rats as measured by Western blot and pNP hydroxylation assay. PCNA analysis of liver sections indicated that EtOH-treated rats had a significantly higher number of cells in S phase of cell division at weeks 1 (3.20 +/- 0.19), 2 (7.03 +/- 0.92), and 3 (4.23 +/- 1.41) when compared to controls (1.5 +/- 0.22). NF-kappaB DNA binding and Cyclin D1 proteins increased significantly in the EtOH-treated rats corresponding with enhanced hepatic proliferation. These data suggest the transient decline in liver injury during alcoholic steatosis is due to enhanced NF-kappaB-dependent hepatocyte proliferation. 相似文献
58.
Luiza Guilherme Ed cio Cunha Neto Guilherme Renesto Anna C. Goldberg Josely Chiarella Rachel Snitcowsky Ma. Helena Kiss Cl vis Silva Jorge Kalil 《Human immunology》1996,47(1-2):20
β-hemolytic streptococcal infection in developing countries still causes thousands of cases of Rheumatic Fever (RF). Molecular mimicry between streptococcal M protein (strep M) and heart components has been proposed as the triggering factor leading to autoimmunity in individuals with genetic susceptibility, which is linked to different HLA-DR alleles in different populations. In our hands, RF was significantly associated to HLA-DR7/53. Previous work in our lab has shown that heart-infiltrating T cells that simultaneously recognize strep M and heart proteins. Further, such T cells predominantly recognized the 81-103 strep M5 epitope. In this work, we analysed the proliferative response of peripheral blood mononuclear cells of 99 RF patients and 40 normal controls. Eighty-nine of the RF patients were HLA-typed. As among heart-infiltrating T cells, the 81-103 strep M5 protein epitope is the most frequently recognized epitope among RF PBMC (35.4%), against a 7.5% frequency of proliferation among normal controls (p=0.0018, chi square). However, the 81-103 epitope was as frequently recognized by HLA-DR7,53 positive as by negative individuals (45.2% vs 54.8%, respectively). Taken together, the results suggest that the 81-103 strep M5 epitope may be the immunodominant epitope, “promiscuously” recognized by T cells in a genetically diverse population. The demonstration that molecular mimicry is targeted to a discrete immunodominant “promiscuous” epitope in strep M5 may allow the development of a safe anti-streptococcal synthetic vaccine devoid of such epitopes. 相似文献
59.
60.
Vascular Endothelial Growth Factor/Vascular Permeability Factor Is Temporally and Spatially Correlated with Ocular Angiogenesis in a Primate Model 总被引:19,自引:2,他引:19 下载免费PDF全文
Joan W. Miller Anthony P. Adamis David T. Shima Patricia A. D'Amore Rachel S. Moulton Michael S. O'Reilly Judah Folkman Harold F. Dvorak Lawrence F. Brown Brygida Berse Tet-Kin Yeo Kiang-Teck Yeo 《The American journal of pathology》1994,145(3):574-584
Ischemia often precedes neovascularization. Inocular neovascularization, such as occurs in diabetic retinopathy, a diffusible angiogenic factor has been postulated to be produced by ischemicretina and to lead to neovascularization of theretina, optic nerve, or iris. However, no angiogenic factor has been conclusively identified that satisfies this hypothesis. Vascular endothelial growth factor/vascular permeability factor, hereafter referred to as VEGF, is a likely candidate for an ocular angiogenic factor because it is a secreted mitogen, specific for endothelial cells, and is upregulated by hypoxia. We investigated the association of VEGF with the development of experimental iris neovascularization in the cynomolgus monkey. Following theproduction of retinal ischemia by laser occlusion of all branch retinal veins, VEGF was increased in the aqueous fluid, and the aqueous VEGF levels changed synchronously and proportionally with the severity of iris neovascularization. Northern analysis and in situ hybridization revealed that VEGF messenger RNA is upregulated in the ischemic retina. These observations support the hypothesis that ocular neovascularization is regulated by a diffusible factor and identify VEGF as a likely candidate for a retina-derived vascular permeability and angiogenesis factor in vivo. 相似文献