全文获取类型
收费全文 | 1073篇 |
免费 | 56篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 17篇 |
妇产科学 | 9篇 |
基础医学 | 208篇 |
口腔科学 | 32篇 |
临床医学 | 64篇 |
内科学 | 153篇 |
皮肤病学 | 6篇 |
神经病学 | 119篇 |
特种医学 | 29篇 |
外科学 | 77篇 |
综合类 | 27篇 |
预防医学 | 65篇 |
眼科学 | 19篇 |
药学 | 133篇 |
中国医学 | 7篇 |
肿瘤学 | 158篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 9篇 |
2019年 | 10篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 12篇 |
2015年 | 19篇 |
2014年 | 25篇 |
2013年 | 22篇 |
2012年 | 50篇 |
2011年 | 71篇 |
2010年 | 17篇 |
2009年 | 28篇 |
2008年 | 71篇 |
2007年 | 60篇 |
2006年 | 66篇 |
2005年 | 78篇 |
2004年 | 105篇 |
2003年 | 68篇 |
2002年 | 70篇 |
2001年 | 60篇 |
2000年 | 28篇 |
1999年 | 31篇 |
1998年 | 17篇 |
1997年 | 15篇 |
1996年 | 16篇 |
1995年 | 18篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 16篇 |
1991年 | 20篇 |
1990年 | 20篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1954年 | 2篇 |
1952年 | 2篇 |
1951年 | 1篇 |
1950年 | 1篇 |
1949年 | 1篇 |
1875年 | 2篇 |
排序方式: 共有1138条查询结果,搜索用时 15 毫秒
1.
Efficacy of radical neck dissection for the control of cervical metastasis after radiotherapy for nasopharyngeal carcinoma 总被引:5,自引:0,他引:5
Fifty-one patients who had persistent or recurrent neck disease from nasopharyngeal carcinoma after radiotherapy underwent radical neck dissection. The follow-up period ranged from 0.5 to 9 years (median: 2 years). Multiple cervical lymph node involvement was present in 51% of the patients (26 of 51). Malignant cells were detected in 88% of the resected specimens (45 of 51). The clinical sign of fixation of lymph node is the only factor that affects the successful control of neck disease (p = 0.04). Extracapsular extension of the nodal disease was present, and 35% of the lymph nodes were adherent to surrounding structures at operation (18 of 51). There was one hospital mortality and the overall morbidity was minimal. The actuarial survival at 5 years was 38%, and the probability of control of neck disease was 66%. Radical neck dissection is effective in controlling post-irradiation cervical metastasis from nasopharyngeal carcinoma. 相似文献
2.
3.
S. Shaikh D. A. Collier P. Sham L. Pilowsky T. Sharma L. K. Lin M. A. Crocq M. Gill R. Kerwin 《American journal of medical genetics. Part A》1995,60(6):541-545
We have examined the hypothesis that a variable number of tandem repeats in the third cytoplasmic loop of the dopamine D4 receptor influences clinical response to clozapine using a sample of 189 schizophrenic patients. Alleles of the 48-bp repeat, which range from two to ten copies in the normal human population, were analysed by the polymerase chain reaction using genomic DNA as template. Association between these alleles and response to clozapine was tested using the difference in pre-and post-treatment GAS scores as a measure of response. We found no statistically significant variation between genotypic groups and response by analysis of variance. We conclude that the variation of the number of 48-bp repeats alone does not determine response to clozapine. Larger studies are underway to determine if there is a more subtle relationship with sequence variation within the repeats or at other polymorphic sites within the gene that may provide evidence for a component of clozapine's action being at D4 receptors. © 1995 Wiley-Liss, Inc. 相似文献
4.
J S Sham W I Wei D Choy C M Ho P T Tai P H Choi 《The British journal of radiology》1989,62(736):355-361
The early results of brachytherapy for persistent and recurrent nasopharyngeal carcinoma in 30 patients is presented. Fifteen patients were treated by intracavitary caesium, 12 patients were treated by interstitial gold grain implant using the split-palate approach and three patients were treated by both intracavitary caesium and interstitial gold grain implant for the first and second relapse in the nasopharynx, respectively. The overall tumour control rate for intracavitary caesium was 5/18 (28%) with median follow-up of 25.2 months, and for interstitial gold grain implant it was 9/14 (64%) with median follow-up of 16.5 months. Interstitial gold grain implantation appears to be effective in the treatment of persistent and recurrent nasopharyngeal carcinoma. 相似文献
5.
6.
Sarah Curran Shaun Purcell Ian Craig Philip Asherson Pak Sham 《American journal of medical genetics. Part B, Neuropsychiatric genetics》2005,(1):42-47
Molecular studies of attention deficit hyperactivity disorder (ADHD) have identified susceptibility genes for the categorically diagnosed disorder using operational diagnostic criteria. Here, we take a QTL approach to mapping genes for ADHD using a composite continuous index of ADHD behavior in a large epidemiological sample. Previous studies of clinical ADHD suggest that two functional polymorphisms in the serotonin transporter gene (SLC6A4), one in the 5'-regulatory region of the gene (5-HTTLPR) and the other a VNTR (5-HTTVNTR) in the second intron, as well as a single nucleotide polymorphism in the 3'-untranslated region (3'-UTR SNP), may be associated with the disorder. Here, we investigate these polymorphisms as well as an additional ten SNPs spread across the gene. We found significant association with the long (L) allele of the 5-HTTLPR; P = 0.019, but neither the 5-HTTVNTR nor the 3'-UTR SNP were significantly associated. Significant associations (P < 0.05) were found for a further 5 the 10 other markers tested. We found evidence for two haplotype blocks spanning the region. We found strong evidence for association with the first haplotype block (comprised of four markers), with the significance of a combined primary and secondary test of association reaching an empirical P value = 0.0054 for the global test and an empirical P value = 0.00081 for the largest local test. Thus, we show here that SLC6A4, which has a major influence on brain serotonin availability, may be a QTL for ADHD. 相似文献
7.
102T/C polymorphism of serotonin receptor type 2A gene is not associated with schizophrenia in either Chinese or British populations 总被引:7,自引:0,他引:7
He L Li T Melville C Liu S Feng GY Gu NF Fox H Shaw D Breen G Liu X Sham P Brown J Collier D St Clair D 《American journal of medical genetics》1999,88(1):95-98
Several pieces of evidence implicate serotonin receptors in the aetiology of schizophrenia, and recently a number of studies have reported a genetic association between the 102T/C polymorphism of serotonin receptor type 2A gene and schizophrenia. Unfortunately a number of failures to replicate these positive associations in both Caucasian and Chinese populations have also been reported. We have examined the 102T/C polymorphism by PCR amplification and restriction analysis of DNA from: 202 schizophrenics and 202 controls from Shanghai; 112 schizophrenics and 224 parents from Chengdu, Cina; and 253 schizophrenics and 244 controls from the the UK. We find no evidence of association or transmission disequilibrium between the 102T/C polymorphism and schizophrenia in any of the groups we have examined. We conclude that either the original positive reports occurred by chance or any effect must be minimal, and urge caution in interpreting small positive results derived using data from different centres. 相似文献
8.
Correlation of AIB1 overexpression with advanced clinical stage of human colorectal carcinoma 总被引:7,自引:0,他引:7
AIB1, a member of the steroid receptor coactivator 1 family, has been cloned on 20q12 and is a candidate oncogene in human breast cancer. It is commonly amplified and overexpressed in several types of human cancers. In this study, we examined the expression of AIB1, as related to clinicopathologic features, in 85 human colorectal cancers (CRCs). The status of the number of AIB1 copies, p53 expression, and DNA ploidy was also analyzed. The overexpression of AIB1 was detected in 35% of CRCs. Amplification of AIB1 was observed in 10% of CRCs. In addition, the overexpression of AIB1 was observed more frequently in CRCs in later clinical stages (T3 N1 M0/T3 N0 2M1), compared with that in T3 N0 M0 stage (P < .05). These results suggest that overexpression of AIB1 might provide a selective advantage for the developmental growth and/or progression of subsets of CRCs. In addition, a significant correlation (P < .05) of overexpression of AIB1 with p53 overexpression as well as with aneuploid DNA content was observed in these CRCs. The overexpression of p53 was also correlated significantly with CRC DNA ploidy (P < .05). Furthermore, there was a substantial population of CRCs showing overexpression of both AIB1 and p53 protein and all had aneuploid DNA content; most of these were in the later clinical stage. These findings suggest a possible convergence of AIB1 with a pathway involving p53, which might induce chromosomal instability and affect the clinical phenotype of a subset of CRCs. 相似文献
9.
Recurrent genetic alterations in 26 colorectal carcinomas and 21 adenomas from Chinese patients 总被引:5,自引:0,他引:5
He QJ Zeng WF Sham JS Xie D Yang XW Lin HL Zhan WH Lin F Zeng SD Nie D Ma LF Li CJ Lu S Guan XY 《Cancer Genetics and Cytogenetics》2003,144(2):112-118
Colorectal cancer (CRC) is one of the most common malignancies worldwide. The incidence of CRC in the Chinese population has increased dramatically during the last two decades; however, nonrandom chromosomal alterations in Chinese patients have not been described. In the present study, comparative genomic hybridization (CGH) was applied to detect recurrent chromosome alterations in 26 primary colorectal carcinomas and 21 colorectal adenomas from Chinese patients. In CRC, several recurrent chromosomal changes were found, including gains of 8q (14/26 cases, 54%), 20q (54%), 3q (50%), 13q (50%), 5p (46%), 7p (42%), 7q (42%), and 12p (38%) and losses of 18q (65%) and 17p (42%). From comparison with previous CGH studies, the frequent gains of 3q and 12p might be distinctive occurrences in Chinese patients. The distribution of frequently found chromosomal alterations in different locations was studied. The gain of 20q was more frequently found in colon cancer (P<0.01) and the gain of 12p was more frequently found in rectal cancer. Chromosomal alterations were found in 19/21 of adenomas; the most frequent chromosomal alteration was the loss of 18q (9/21 cases, 43%). These recurrent alterations provide several starting points for the isolation of candidate oncogenes and tumor suppressor genes. 相似文献
10.
Life events and depression in a community sample of siblings 总被引:4,自引:0,他引:4
Rijsdijk FV Sham PC Sterne A Purcell S McGuffin P Farmer A Goldberg D Mann A Cherny SS Webster M Ball D Eley TC Plomin R 《Psychological medicine》2001,31(3):401-410
BACKGROUND: The overall aim of the GENESiS project is to identify quantitative trait loci (QTLs) for anxiety/depression, and to examine the interaction between these loci and psychosocial adversity. Here we present life-events data with the aim of clarifying: (i) the aetiology of life events as inferred from sibling correlations; (ii) the relationship between life events and measures of anxiety and depression, as well as neuroticism; and (iii) the interaction between life events and neuroticism on anxiety/depression indices. METHODS: We assessed the occurrence of one network and three personal life-event categories and multiple indices of anxiety/depression including General Health Questionnaire, Anhedonic Depression, Anxious Arousal and Neuroticism in a large community-based sample of2150 sib pairs, 410 trios and 81 quads. Liability threshold models and raw ordinal maximum likelihood were used to estimate within-individual and between-sibling correlations of life events. The relationship between life events and indices of emotional states and personality were assessed by multiple linear regression and canonical correlations. RESULTS: Life events showed sibling correlations of 0-37 for network events and between 0-10 and 0.19 for personal events. Adverse life events were related to anxiety and depression and, to a less extent, neuroticism. Trait-vulnerability (as indexed by co-sib's neuroticism, anxiety and depression) accounted for 11% and life events for 3% of the variance in emotional states. There were no interaction effects. CONCLUSIONS: Life events show moderate familiality and are significantly related to symptoms of anxiety and depression in the community. Appropriate modelling of life events in linkage and association analyses should help to identify QTLs for depression and anxiety. 相似文献