全文获取类型
收费全文 | 13304篇 |
免费 | 978篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 119篇 |
儿科学 | 514篇 |
妇产科学 | 211篇 |
基础医学 | 1711篇 |
口腔科学 | 157篇 |
临床医学 | 1447篇 |
内科学 | 2641篇 |
皮肤病学 | 209篇 |
神经病学 | 1290篇 |
特种医学 | 454篇 |
外国民族医学 | 2篇 |
外科学 | 1823篇 |
综合类 | 195篇 |
一般理论 | 12篇 |
预防医学 | 1098篇 |
眼科学 | 537篇 |
药学 | 1048篇 |
中国医学 | 24篇 |
肿瘤学 | 825篇 |
出版年
2023年 | 64篇 |
2022年 | 116篇 |
2021年 | 316篇 |
2020年 | 180篇 |
2019年 | 268篇 |
2018年 | 324篇 |
2017年 | 274篇 |
2016年 | 275篇 |
2015年 | 348篇 |
2014年 | 417篇 |
2013年 | 658篇 |
2012年 | 994篇 |
2011年 | 1009篇 |
2010年 | 551篇 |
2009年 | 461篇 |
2008年 | 777篇 |
2007年 | 875篇 |
2006年 | 808篇 |
2005年 | 834篇 |
2004年 | 742篇 |
2003年 | 696篇 |
2002年 | 627篇 |
2001年 | 176篇 |
2000年 | 179篇 |
1999年 | 160篇 |
1998年 | 167篇 |
1997年 | 123篇 |
1996年 | 88篇 |
1995年 | 102篇 |
1994年 | 120篇 |
1993年 | 76篇 |
1992年 | 117篇 |
1991年 | 114篇 |
1990年 | 90篇 |
1989年 | 94篇 |
1988年 | 83篇 |
1987年 | 60篇 |
1986年 | 74篇 |
1985年 | 77篇 |
1984年 | 75篇 |
1983年 | 62篇 |
1982年 | 77篇 |
1981年 | 66篇 |
1980年 | 52篇 |
1979年 | 66篇 |
1978年 | 51篇 |
1977年 | 38篇 |
1974年 | 32篇 |
1973年 | 33篇 |
1972年 | 34篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
911.
912.
Binnie CD 《Lancet neurology》2003,2(12):725-730
Epileptiform EEG discharges are not confined to people with epilepsy, and their frequency is only weakly related to severity. A fundamental principle of EEG practice is, therefore, to avoid overinterpretation of epileptiform activity. Epileptiform discharges not accompanied by obvious clinical events are generally regarded as subclinical or interictal. However, in many patients sensitive methods of observation, notably continuous psychological testing, show brief episodes of impaired cognitive function during such discharges. This phenomenon of transitory cognitive impairment (TCI) is found in about 50% of patients who show discharges during testing. TCI is not simple inattention. The effects are material and site specific: lateralised discharges are associated with deficits of functions mediated by the hemisphere in which the discharges occur. Conversely, specific tasks can activate or suppress focal discharges over the brain regions that mediate the cognitive activity in question. TCI clearly contributes to the cognitive problems of some people with epilepsy and may cause deficits that pass unrecognised. TCI is demonstrable in many cases of benign partial epilepsy of childhood, a disorder once thought to have no adverse psychological effects. TCI can contribute to abnormalities of psychological test profiles and interferes with daily tasks, such as reading and driving. In children it may be associated with behavioural disorders. An important practical issue is whether TCI materially impairs psychosocial function and, if so, whether drug treatment is desirable or effective. Uncontrolled reports and two preliminary randomised controlled trials of antiepileptic treatment of TCI have suggested that suppression of discharges is associated with significant improvement in psychosocial function. 相似文献
913.
Previous studies point to a lower use of radiotherapy by Australian cancer patients in lower socioeconomic areas and in country regions that are some distance from urban treatment centres. These were cross-sectional studies with the potential for error from changes in place of residence. We used a cohort design to avoid such error. South Australian patients diagnosed in 1990-1994 were followed until the date of censoring of 31 December 1999 using data from the State Cancer Registry. The percentage found to have had megavoltage therapy in the first 12 months following diagnosis varied by leading primary incidence site from 44% for the prostate to 40% for female breast, 38% for lung, 17% for rectum, 3% for colon and 2% for skin (melanoma). Multivariate analysis indicated that determinants of not receiving megavoltage therapy in the first 12 months were older age, female sex, residence in a country region and country of birth. Melanoma data revealed earlier stages for women than men. If this difference by sex applies to other cancers, it might explain the lower exposure of women to radiotherapy. Fewer older patients received radiotherapy, consistent with trends observed in hospital-based cancer-registry data. The influence on this finding of differences in stage and comorbidity requires additional study. While earlier findings of a lower exposure of country residents to radiotherapy were confirmed, the difference was comparatively small in this study. Variations in exposure by socioeconomic status of residential area were not observed. 相似文献
914.
Woolsey S Nambirajan T Mahendra V Mulholland C Kernohan R 《Scandinavian journal of urology and nephrology》2003,37(3):269-270
Tumours arising in bowel-augmented bladders are rare. Usually these tumours are adenocarcinomas that occur along the anastomotic line. We present two unusual tumours, squamous cell carcinoma and transitional cell carcinoma, that occurred in bladder augmentations. We also emphasize the need for regular cystoscopic surveillance. 相似文献
915.
916.
Genome-wide screening for complete genetic loss in prostate cancer by comparative hybridization onto cDNA microarrays 总被引:6,自引:0,他引:6
Clark J Edwards S Feber A Flohr P John M Giddings I Crossland S Stratton MR Wooster R Campbell C Cooper CS 《Oncogene》2003,22(8):1247-1252
We demonstrate that comparative genomic hybridization (CGH) onto cDNA microarrays may be used to carry out genome-wide screens for regions of genetic loss, including homozygous (complete) deletions that may represent the possible location of tumour suppressor genes in human cancer. Screening of the prostate cancer cell lines LNCaP, PC3 and DU145 allowed the mapping of specific regions where genome copy number appeared altered and led to the identification of two novel regions of complete loss at 17q21.31 (500 kb spanning STAT3) and at 10q23.1 (50-350 kb spanning SFTPA2) in the PC3 cell line. 相似文献
917.
Clancy JL Henderson MJ Russell AJ Anderson DW Bova RJ Campbell IG Choong DY Macdonald GA Mann GJ Nolan T Brady G Olopade OI Woollatt E Davies MJ Segara D Hacker NF Henshall SM Sutherland RL Watts CK 《Oncogene》2003,22(32):5070-5081
EDD (E3 isolated by differential display), located at chromosome 8q22.3, is the human orthologue of the Drosophila melanogaster tumour suppressor gene 'hyperplastic discs' and encodes a HECT domain E3 ubiquitin protein-ligase. To investigate the possible involvement of EDD in human cancer, several cancers from diverse tissue sites were analysed for allelic gain or loss (allelic imbalance, AI) at the EDD locus using an EDD-specific microsatellite, CEDD, and other polymorphic microsatellites mapped in the vicinity of the 8q22.3 locus. Of 143 cancers studied, 38 had AI at CEDD (42% of 90 informative cases). In 14 of these cases, discrete regions of imbalance encompassing 8q22.3 were present, while the remainder had more extensive 8q aberrations. AI of CEDD was most frequent in ovarian cancer (22/47 informative cases, 47%), particularly in the serous subtype (16/22, 73%), but was rare in benign and borderline ovarian tumours. AI was also common in breast cancer (31%), hepatocellular carcinoma (46%), squamous cell carcinoma of the tongue (50%) and metastatic melanoma (18%). AI is likely to represent amplification of the EDD gene locus rather than loss of heterozygosity, as quantitative RT-PCR and immunohistochemistry showed that EDD mRNA and protein are frequently overexpressed in breast and ovarian cancers, while among breast cancer cell lines EDD overexpression and increased gene copy number were correlated. These results demonstrate that AI at the EDD locus is common in a diversity of carcinomas and that the EDD gene is frequently overexpressed in breast and ovarian cancer, implying a potential role in cancer progression. 相似文献
918.
919.
Kotsopoulos J Sohn KJ Martin R Choi M Renlund R McKerlie C Hwang SW Medline A Kim YI 《Carcinogenesis》2003,24(5):937-944
Epidemiologic studies have suggested that dietary folate intake is inversely related to breast cancer risk. However, epidemiologic evidence has not been consistent nor has it provided unequivocal support for this purported inverse relationship. This study investigated the effect of dietary folate on N-methyl-N-nitrosourea (MNU)-induced mammary tumorigenesis in rats. Weanling, female Sprague-Dawley rats were fed diets containing either 0 (deficient; n = 22), 2 (basal dietary requirement, control; n = 20) or 8 mg (supplemented; n = 20) folate/kg diet for 30 weeks. At 50 days of age, rats received an i.p. injection of MNU (50 mg/kg body wt). At necropsy, all macroscopic mammary tumors were identified and examined microscopically. The effect of dietary folate on genomic DNA methylation in mammary tumorigenesis was determined by the in vitro methyl acceptance assay. The incidence of mammary adenoma and adenocarcinoma in the folate-deficient group was lower than that of the control and folate-supplemented groups (55 versus 90 and 75%, respectively, P = 0.043). Kaplan-Meier analyses also demonstrated a similar trend in the rates of appearance of either adenoma or adenocarcinoma (P = 0.06). In contrast, folate supplementation did not significantly modulate mammary tumorigenesis compared with the control group. Although mammary tumors were significantly hypomethylated compared with non-neoplastic mammary tissues in each dietary group (P < 0.03), folate status did not significantly affect the extent of DNA methylation. The data suggest that dietary folate deficiency of a moderate degree suppresses, whereas folate supplementation at four times the basal dietary requirement does not significantly modulate, mammary tumorigenesis in this model. The role of folate in mammary tumorigenesis needs to be clarified for safe and effective prevention of breast cancer. 相似文献
920.
Jaisson-Hot I Schott AM Clippe C Ganne C Hajri T Poncet B Trillet-Lenoir V Colin C 《Bulletin du cancer》2003,90(11):939-945
The increasing costs of care make it important to identify those strategies of greatest value from both an effectiveness and cost perspective. Economic analysis is characterized by a simultaneous consideration of alternatives costs and outcomes, and can provide useful data for managerial decision making. In this paper, methods of economic evaluations in general and in cancer in particular is reviewed. In cancer treatment, preventive, curative or palliative strategies can be concerned. Economic evaluation have become increasingly important in oncology because of the proliferation of expensive new treatments. Furthermore, considering quality of life effects is particularly important in oncology, where many treatments obtain modest improvements in response or survival. Quality of life measurements are also reviewed. 相似文献