全文获取类型
收费全文 | 2378篇 |
免费 | 232篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 88篇 |
妇产科学 | 62篇 |
基础医学 | 357篇 |
口腔科学 | 11篇 |
临床医学 | 312篇 |
内科学 | 374篇 |
皮肤病学 | 59篇 |
神经病学 | 122篇 |
特种医学 | 165篇 |
外科学 | 275篇 |
综合类 | 72篇 |
一般理论 | 1篇 |
预防医学 | 251篇 |
眼科学 | 107篇 |
药学 | 170篇 |
中国医学 | 4篇 |
肿瘤学 | 176篇 |
出版年
2021年 | 23篇 |
2020年 | 23篇 |
2019年 | 33篇 |
2018年 | 46篇 |
2017年 | 20篇 |
2016年 | 49篇 |
2015年 | 44篇 |
2014年 | 53篇 |
2013年 | 81篇 |
2012年 | 96篇 |
2011年 | 101篇 |
2010年 | 55篇 |
2009年 | 79篇 |
2008年 | 88篇 |
2007年 | 118篇 |
2006年 | 106篇 |
2005年 | 82篇 |
2004年 | 82篇 |
2003年 | 72篇 |
2002年 | 77篇 |
2001年 | 65篇 |
2000年 | 71篇 |
1999年 | 54篇 |
1998年 | 73篇 |
1997年 | 64篇 |
1996年 | 36篇 |
1995年 | 32篇 |
1994年 | 39篇 |
1993年 | 39篇 |
1992年 | 38篇 |
1991年 | 29篇 |
1990年 | 39篇 |
1989年 | 39篇 |
1988年 | 38篇 |
1987年 | 33篇 |
1986年 | 48篇 |
1985年 | 66篇 |
1984年 | 32篇 |
1983年 | 24篇 |
1982年 | 26篇 |
1981年 | 19篇 |
1980年 | 21篇 |
1979年 | 19篇 |
1978年 | 26篇 |
1977年 | 33篇 |
1976年 | 24篇 |
1974年 | 22篇 |
1971年 | 30篇 |
1970年 | 32篇 |
1969年 | 19篇 |
排序方式: 共有2623条查询结果,搜索用时 31 毫秒
101.
102.
An analysis of nursing students’ decision‐making in teams during simulations of acute patient deterioration
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
103.
104.
Emblem KE Scheie D Due-Tonnessen P Nedregaard B Nome T Hald JK Beiske K Meling TR Bjornerud A. 《中国神经肿瘤杂志》2008,6(2):84-84
BACKGROUND AND PURPOSE: Inclusion of oligodendroglial tumors may confound the utility of MR based glioma grading. Our aim was, first, to assess retrospectively whether a histogram-analysis method of MR peifusion images may both grade gliomas and differentiate between low-grade oligodendroglial tumors with or without loss of heterozygosity (LOH) on 1p/19q and, second, to assess retrospectively whether low-grade oligodendroglial subtypes can be identified in a population of patients with high-grade and low-grade astrocytic and oligodendroglial tumors. 相似文献
105.
Dissecting the Akt/mammalian target of rapamycin signaling network: emerging results from the head and neck cancer tissue array initiative. 总被引:2,自引:0,他引:2
Alfredo A Molinolo Stephen M Hewitt Panomwat Amornphimoltham Somboon Keelawat Samraeung Rangdaeng Abelardo Meneses García Ana R Raimondi Rafael Jufe María Itoiz Yan Gao Dhananjaya Saranath George S Kaleebi George H Yoo Lee Leak Ernest M Myers Satoru Shintani David Wong H Davis Massey W Andrew Yeudall Fulvio Lonardo John Ensley J Silvio Gutkind 《Clinical cancer research》2007,13(17):4964-4973
PURPOSE: As an approach to evaluate the expression pattern and status of activation of signaling pathways in clinical specimens from head and neck squamous cell carcinoma (HNSCC) patients, we established the Head and Neck Cancer Tissue Array Initiative, an international consortium aimed at developing a high-density HNSCC tissue microarray, with a high representation of oral squamous cell carcinoma. EXPERIMENTAL DESIGN: These tissue arrays were constructed by acquiring cylindrical biopsies from multiple individual tumor tissues and transferring them into tissue microarray blocks. From a total of 1,300 cases, 547 cores, including controls, were selected and used to build the array. RESULTS: Emerging information by the use of phosphospecific antibodies detecting the activated state of signaling molecules indicates that the Akt-mammalian target of rapamycin (mTOR) pathway is frequently activated in HNSCC, but independently from the activation of epidermal growth factor receptor or the detection of mutant p53. Indeed, we identified a large group of tissue samples displaying active Akt and mTOR in the absence of epidermal growth factor receptor activation. Furthermore, we have also identified a small subgroup of patients in which the mTOR pathway is activated but not Akt, suggesting the existence of an Akt-independent signaling route stimulating mTOR. CONCLUSIONS: These findings provide important information about the nature of the dysregulated signaling networks in HNSCC and may also provide the rationale for the future development of novel mechanism-based therapies for HNSCC patients. 相似文献
106.
Xiaohong R Yang Mark E Sherman David L Rimm Jolanta Lissowska Louise A Brinton Beata Peplonska Stephen M Hewitt William F Anderson Neonila Szeszenia-Dabrowska Alicja Bardin-Mikolajczak Witold Zatonski Richard Cartun Daniza Mandich Grzegorz Rymkiewicz Marcin Ligaj Stanislaw Lukaszek Radzisaw Kordek Montserrat García-Closas 《Cancer epidemiology, biomarkers & prevention》2007,16(3):439-443
Analysis of gene expression data suggests that breast cancers are divisible into molecular subtypes which have distinct clinical features. This study evaluates whether pathologic features and etiologic associations differ among molecular subtypes. We evaluated 804 women with invasive breast cancers and 2,502 controls participating in a Polish Breast Cancer Study. Immunohistochemical stains for estrogen receptor alpha, progesterone receptor, human epidermal growth factor receptors (HER2 and HER1), and cytokeratin 5 were used to classify cases into five molecular subtypes: luminal A, luminal B, HER2-expresing, basal-like, and unclassified. Relative risks were estimated using adjusted odds ratios and 95% confidence intervals. We observed that compared with the predominant luminal A tumors (69%), other subtypes were associated with unfavorable clinical features at diagnosis, especially HER2-expressing (8%) and basal-like (12%) tumors. Increasing body mass index significantly reduced the risk of luminal A tumors among premenopausal women (odds ratios, 0.71; 95% confidence intervals, 0.57-0.88 per five-unit increase), whereas it did not reduce risk for basal-like tumors (1.18; 0.86-1.64; P(heterogeneity) = 0.003). On the other hand, reduced risk associated with increasing age at menarche was stronger for basal-like (0.78; 0.68-0.89 per 2-year increase) than luminal A tumors (0.90; 0.95-1.08; P(heterogeneity) = 0.0009). Although family history increased risk for all subtypes (except for unclassified tumors), the magnitude of the relative risk was highest for basal-like tumors. Results from this study have shown that breast cancer risk factors may vary by molecular subtypes identified in expression studies, suggesting etiologic, in addition to clinical, heterogeneity of breast cancer. 相似文献
107.
Nadine Zidek Juergen Hellmann Peter-Juergen Kramer Philip G Hewitt 《Toxicological sciences》2007,99(1):289-302
Drug-induced hepatotoxicity is a major issue for drug development, and toxicogenomics has the potential to predict toxicity during early toxicity screening. A bead-based Illumina oligonucleotide microarray containing 550 liver specific genes has been developed. We have established a predictive screening system for acute hepatotoxicity by analyzing differential gene expression profiles of well-known hepatotoxic and nonhepatotoxic compounds. Low and high doses of tetracycline, carbon tetrachloride (CCL4), 1-naphthylisothiocyanate (ANIT), erythromycin estolate, acetaminophen (AAP), or chloroform as hepatotoxicants, clofibrate, theophylline, naloxone, estradiol, quinidine, or dexamethasone as nonhepatotoxic compounds, were administered as a single dose to male Sprague-Dawley rats. After 6, 24, and 72 h, livers were taken for histopathological evaluation and for analysis of gene expression alterations. All hepatotoxic compounds tested generated individual gene expression profiles. Based on leave-one-out cross-validation analysis, gene expression profiling allowed the accurate discrimination of all model compounds, 24 h after high dose treatment. Even during the regeneration phase, 72 h after treatment, CCL4, ANIT, and AAP were predicted to be hepatotoxic, and only these three compounds showed histopathological changes at this time. Furthermore, we identified 64 potential marker genes responsible for class prediction, which reflected typical hepatotoxicity responses. These genes and pathways, commonly deregulated by hepatotoxicants, may be indicative of the early characterization of hepatotoxicity and possibly predictive of later hepatotoxicity onset. Two unknown test compounds were used for prevalidating the screening test system, with both being correctly predicted. We conclude that focused gene microarrays are sufficient to classify compounds with respect to toxicity prediction. 相似文献
108.
Jian-Zhong Shou Nan Hu Mikiko Takikita Mark J Roth Laura Lee Johnson Carol Giffen Quan-Hong Wang Chaoyu Wang Yuan Wang Hua Su Li-Hui Kong Michael R Emmert-Buck Alisa M Goldstein Stephen M Hewitt Philip R Taylor 《Cancer epidemiology, biomarkers & prevention》2008,17(6):1424-1435
Molecular events associated with the initiation and progression of esophageal squamous cell carcinoma (ESCC) remain poorly understood but likely hold the key to effective early detection approaches for this almost invariably fatal cancer. CDC25B and LAMC2 are two promising early detection candidates emerging from new molecular studies of ESCC. To further elucidate the role of these two genes in esophageal carcinogenesis, we did a series of studies to (a) confirm RNA overexpression, (b) establish the prevalence of protein overexpression, (c) relate protein overexpression to survival, and (d) explore their potential as early detection biomarkers. Results of these studies indicated that CDC25B mRNA was overexpressed (>/=2-fold overexpression in tumor compared with normal) in 64% of the 73 ESCC cases evaluated, whereas LAMC2 mRNA was overexpressed in 89% of cases. CDC25B protein expression was categorized as positive in 59% (144 of 243) of ESCC cases on a tumor tissue microarray, and nonnegative LAMC2 patterns of protein expression were observed in 82% (225 of 275) of cases. Multivariate-adjusted proportional hazard regression models showed no association between CDC25B protein expression score and risk of death [hazard ratio (HR) for each unit increase in expression score, 1.00; P = 0.90]; however, several of the LAMC2 protein expression patterns strongly predicted survival. Using the cytoplasmic pattern as the reference (the pattern with the lowest mortality), cases with a diffuse pattern had a 254% increased risk of death (HR, 3.52; P = 0.007), cases with no LAMC2 expression had a 169% increased risk of death (HR, 2.69; P = 0.009), and cases with a peripheral pattern had a 130% greater risk of death (HR, 2.30; P = 0.02). CDC25B protein expression scores in subjects with esophageal biopsies diagnosed as normal (n = 35), dysplastic (n = 23), or ESCC (n = 32) increased significantly with morphologic progression. For LAMC2, all normal and dysplastic patients had a continuous pattern of protein expression, whereas all ESCCs showed alternative, noncontinuous patterns. This series of studies showed that both CDC25B and LAMC2 overexpress RNA and protein in a significant majority of ESCC cases. The strong relation of LAMC2 pattern of protein expression to survival suggests a role in prognosis, whereas the association of CDC25B with morphologic progression indicates a potential role as an early detection marker. 相似文献
109.
Christina Hewitt 《Behavior genetics》2000,30(6):499-500
Summary List
Referees for Volume 30 相似文献110.