全文获取类型
收费全文 | 1732篇 |
免费 | 138篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 46篇 |
儿科学 | 38篇 |
妇产科学 | 41篇 |
基础医学 | 193篇 |
口腔科学 | 22篇 |
临床医学 | 129篇 |
内科学 | 321篇 |
皮肤病学 | 31篇 |
神经病学 | 136篇 |
特种医学 | 50篇 |
外科学 | 273篇 |
综合类 | 21篇 |
一般理论 | 1篇 |
预防医学 | 126篇 |
眼科学 | 90篇 |
药学 | 91篇 |
中国医学 | 13篇 |
肿瘤学 | 253篇 |
出版年
2023年 | 23篇 |
2022年 | 45篇 |
2021年 | 97篇 |
2020年 | 58篇 |
2019年 | 78篇 |
2018年 | 97篇 |
2017年 | 56篇 |
2016年 | 87篇 |
2015年 | 61篇 |
2014年 | 72篇 |
2013年 | 82篇 |
2012年 | 141篇 |
2011年 | 146篇 |
2010年 | 63篇 |
2009年 | 65篇 |
2008年 | 85篇 |
2007年 | 96篇 |
2006年 | 87篇 |
2005年 | 64篇 |
2004年 | 55篇 |
2003年 | 52篇 |
2002年 | 53篇 |
2001年 | 22篇 |
2000年 | 33篇 |
1999年 | 33篇 |
1998年 | 8篇 |
1997年 | 5篇 |
1996年 | 7篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 9篇 |
1991年 | 8篇 |
1990年 | 6篇 |
1989年 | 10篇 |
1988年 | 7篇 |
1987年 | 4篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1979年 | 4篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1967年 | 4篇 |
1966年 | 4篇 |
1963年 | 2篇 |
排序方式: 共有1875条查询结果,搜索用时 484 毫秒
91.
Abnormalities of the RB1 pathway in ovarian serous papillary carcinoma as determined by overexpression of the p16(INK4A) protein. 总被引:2,自引:0,他引:2
Jane E Armes Rohan Lourie Melanie de Silva Georgia Stamaratis Alison Boyd Beena Kumar Gareth Price Simon Hyde David Allen Peter Grant Deon J Venter 《International journal of gynecological pathology》2005,24(4):363-368
Dysfunction of proteins involved in the G1 to S transition of the cell cycle, such as p16(INK4A) and RB1, is common in many cancer types. A screen of p16 protein expression was performed in benign, borderline, and invasive ovarian tumors, together with endometrial cancers, aligned on a tissue microarray. We observed frequent p16 overexpression in serous papillary carcinomas of ovarian and endometrial origin. An extended cohort of ovarian serous papillary carcinomas was examined to further evaluate the frequency of p16 overexpression. Strong, uniform staining in the majority of cancer cells occurred commonly in invasive serous papillary ovarian cancers, particularly in grade 3 carcinomas. RB1 protein expression abnormalities were rare. Our data indicate that abnormalities in the retinoblastoma pathway, as determined by p16 overexpression, are common in serous papillary carcinomas and are probably an early event. 相似文献
92.
Thomas E Rohan Shu-Qiu Li Robert Hartwick Rita A Kandel 《Cancer epidemiology, biomarkers & prevention》2006,15(7):1316-1323
Disruption of p53 gene function seems to have a pivotal role in carcinogenesis. p53 gene changes occur before the development of breast cancer and therefore might influence breast cancer risk. We investigated the association between p53 protein accumulation and p53 mutations detected in benign breast tissue and risk of subsequent breast cancer. We conducted a case-control study nested within the cohort of 4,888 women in the Canadian National Breast Screening Study who were diagnosed with biopsy-confirmed benign breast disease during active follow-up. Cases were women with benign breast disease who subsequently developed breast cancer; five controls were matched to each case. p53 protein accumulation was assessed immunohistochemically using sections of paraffin-embedded benign breast tissue from 104 cases and 385 controls; for 82 of these cases and 327 of the controls, DNA was successfully extracted from the breast tissue for p53 gene analysis using PCR-single-strand conformation polymorphism/direct sequencing. p53 protein accumulation was associated with a 2-fold increase in risk of progression to breast cancer [adjusted odds ratio (OR), 2.16; 95% confidence interval (95% CI), 1.08-4.30], whereas p53 nucleotide changes overall were not associated with altered risk (adjusted OR, 1.22; 95% CI, 0.68-2.19); those with both p53 immunopositivity and a p53 nucleotide change had an OR (95% CI) of 3.20 (1.21-8.50). Nonpolymorphic intronic changes were associated with a 2.8-fold increase in risk (OR, 2.84; 95% CI, 1.09-7.41). The results of this study suggest that p53 protein accumulation and nonpolymorphic intronic changes in p53 are associated with increased risk of progression to breast cancer in women with benign breast disease. 相似文献
93.
Helen Trottier Salaheddin Mahmud Maria Cecilia Costa Jo?o P Sobrinho Eliane Duarte-Franco Thomas E Rohan Alex Ferenczy Luisa L Villa Eduardo L Franco 《Cancer epidemiology, biomarkers & prevention》2006,15(7):1274-1280
BACKGROUND: Besides an established role for certain human papillomavirus (HPV) genotypes in the etiology of cervical cancer, little is known about the influence of multiple-type HPV infections on cervical lesion risk. We studied the association between multiple HPV types and cervical lesions among 2,462 Brazilian women participating in the Ludwig-McGill study group investigation of the natural history of HPVs and cervical neoplasia. METHODS: Cervical specimens were typed by a PCR protocol. The cohort's repeated-measurement design permitted the assessment of the relation between the cumulative and concurrent number of HPV types and any-grade squamous intraepithelial lesions (SIL) and high-grade SIL (HSIL). RESULT: At individual visits, 1.9% to 3.2% of the women were infected with multiple HPVs. Cumulatively during the first year and the first 4 years of follow-up, 12.3% and 22.3% were infected with multiple types, respectively. HSIL risk markedly increased with the number of types [odds ratio (OR), 41.5; 95% confidence interval (95% CI), 5.3-323.2 for single-type infections; OR, 91.7; 95% CI, 11.6-728.1 for two to three types; and OR, 424.0; 95% CI, 31.8-5651.8 for four to six types, relative to women consistently HPV-negative during the first year of follow-up]. The excess risks for multiple-type infections remained after exclusion of women infected with HPV-16, with high-risk HPV types, or persistent infections, particularly for any-grade SIL. Coinfections involving HPV-16 and HPV-58 seemed particularly prone to increase risk. CONCLUSION: Infections with multiple HPV types seem to act synergistically in cervical carcinogenesis. These findings have implications for the management of cervical lesions and prediction of the outcome of HPV infections. 相似文献
94.
95.
Satoshi Teramukai Thomas Rohan Kyong-Yeon Lee Hiroyuki Eguchi Takashi Oda Suminori Kono 《Cancer science》2002,93(11):1187-1194
Several epidemiological studies have found that high levels of plasma insulin-like growth factor (IGF)-I and low levels of IGF-binding protein (IGFBP)-3 are related to an increased risk of colorectal cancer or late-stage adenomas. We examined the relation of body mass index, fasting and 2-h postload plasma glucose levels and plasma concentrations of IGF-I and IGFBP-3 to colorectal adenomas in middle-aged Japanese men. The study subjects comprised 157 cases of histologically diagnosed colorectal adenomas and 311 controls with normal colonoscopy or non-polyp benign lesions in a consecutive series of 803 men receiving a preretirement health examination at two hospitals of the Self Defense Forces (SDF). After adjustment for rank in the SDF, hospital, smoking and IGFBP-3, a statistically nonsignificant modest increase in the prevalence odds of colorectal adenomas was observed for the highest versus the lowest quartile level of IGF-I. The increase was slightly greater with further adjustment for 2-h glucose concentrations (adjusted odds ratio 1.8, 95% confidence interval 1.0–4.5, trend P =0.06). Men with high levels of IGFBP-3 showed only a minimal decrease in risk after adjustment for IGF-I. The association with IGF-I was less evident for advanced adenomas (≥5 mm in size or tubulovillous/villous). Fasting and 2-h glucose and body mass index were more strongly positively associated with colorectal adenomas than IGF-I, especially with advanced adenomas, independently of IGF-I and IGFBP-3. The findings suggest that plasma IGF-I and IGFBP-3 may be involved in colorectal tumorigenesis regardless of the stage in growth of adenoma, but not as a mediator for the effects of being overweight or of hyperglycemia. 相似文献
96.
97.
98.
A polysaccharide hydrogel was isolated from the seeds of Tamarindus indica (tamarind) and was used as release modifier for the preparation of diclofenac sodium spheroids, using extrusion-spheronization technique. The process was studied for the effect of variables to arrive at spheroids with satisfactory particle shape, size and size-distribution. The prepared spheroids were characterized for surface morphology, qualitative surface porosity, friability, bulk density, and flow properties. The in vitro release studies exhibited a zero-order release kinetics that was confirmed by Higuchi's and Peppas' models. A credible correlation was obtained among swelling index, viscosity, surface roughness of the polysaccharide, and in vitro dissolution profile of the spheroids. In the comparative bioavailability study, we found that the developed spheroids were able to sustain the drug release over 8 hr and could improve the extent of absorption and bioavailability of the drug. 相似文献
99.
100.
Hazra R Gafni RI Maldarelli F Balis FM Tullio AN DeCarlo E Worrell CJ Steinberg SM Flaherty J Yale K Kearney BP Zeichner SL 《Pediatrics》2005,116(6):e846-e854