全文获取类型
收费全文 | 1434篇 |
免费 | 113篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 54篇 |
妇产科学 | 75篇 |
基础医学 | 194篇 |
口腔科学 | 28篇 |
临床医学 | 140篇 |
内科学 | 188篇 |
皮肤病学 | 9篇 |
神经病学 | 80篇 |
特种医学 | 118篇 |
外科学 | 111篇 |
综合类 | 61篇 |
一般理论 | 3篇 |
预防医学 | 171篇 |
眼科学 | 17篇 |
药学 | 226篇 |
中国医学 | 3篇 |
肿瘤学 | 94篇 |
出版年
2023年 | 7篇 |
2022年 | 18篇 |
2021年 | 36篇 |
2020年 | 21篇 |
2019年 | 26篇 |
2018年 | 36篇 |
2017年 | 23篇 |
2016年 | 27篇 |
2015年 | 33篇 |
2014年 | 29篇 |
2013年 | 38篇 |
2012年 | 67篇 |
2011年 | 77篇 |
2010年 | 35篇 |
2009年 | 26篇 |
2008年 | 64篇 |
2007年 | 76篇 |
2006年 | 70篇 |
2005年 | 69篇 |
2004年 | 58篇 |
2003年 | 71篇 |
2002年 | 49篇 |
2001年 | 46篇 |
2000年 | 47篇 |
1999年 | 47篇 |
1998年 | 20篇 |
1997年 | 21篇 |
1996年 | 14篇 |
1995年 | 15篇 |
1994年 | 21篇 |
1993年 | 21篇 |
1992年 | 28篇 |
1991年 | 30篇 |
1990年 | 30篇 |
1989年 | 28篇 |
1988年 | 22篇 |
1987年 | 26篇 |
1986年 | 31篇 |
1985年 | 17篇 |
1984年 | 26篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 11篇 |
1980年 | 7篇 |
1979年 | 10篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1975年 | 12篇 |
1967年 | 5篇 |
1966年 | 6篇 |
排序方式: 共有1582条查询结果,搜索用时 0 毫秒
11.
12.
Marais DJ Rose RC Lane C Kay P Nevin J Denny L Soeters R Dehaeck CM Williamson AL 《Journal of medical virology》2000,60(4):403-410
The aim of the study was to determine the prevalence of antibodies to human papillomavirus (HPV) types 16, 18, 31, 33, and 45 in woman in Cape Town with cervical intraepithelial neoplasia (CIN) (n = 95), cervical cancer (n = 40), female blood donors (n = 95) and children (n = 110). The enzyme-linked immunosorbent assay (ELISA) made use of baculovirus synthesised HPV virus like particles (VLPs) as antigen. Antibodies to at least one HPV type were detected in sera from 75% of cancer patients, 71.6% of CIN patients, 44.2% of blood donors and 27.3% of children. Sera from 95 women with CIN were compared with age-matched female blood donors. There was a significant association of seropositivity to VLP-16 (P = 0.006) and VLP-45 (P = 0.008) with CIN compared with the blood donors. There was also a significant difference in the seropositivity of women with CIN to any of the five virus-like particle (VLP) types compared to the blood donors (P = 0.0002: OR = 3.2). Thirty-nine of sixty-nine (56.5%) women with CIN were found to be HPV-16 DNA positive. The average age of women in this group that were VLP-16 seropositive was 34 years and those found to be VLP-16 seronegative was 52 years of age. Antibodies to all five VLP types were detected in these populations, thus an ideal vaccine should induce protection from infection by a wide range of HPV types. 相似文献
13.
14.
A male factor is implicated in more than 50% of couples treated with IVF. However, neither the routine testing of male fertility potential nor its treatment address the specific mechanisms by which spermatozoal factors may impact upon reproductive outcome. An important function of spermatozoa is to deliver the paternal genome to the oocyte. Recently, a number of acquired spermatozoal nuclear factors that may have implications on reproductive outcome have been described. These include non-specific DNA strand breaks, numerical abnormalities in spermatozoal chromosome content, Y chromosome microdeletions and alterations in the epigenetic regulation of paternal genome. The exact mechanisms by which these factors affect reproduction are unknown and their implications for assisted reproduction technology outcome need to be further investigated. These recent findings point to the need for novel and more personalized approaches to test and treat male factor infertility. 相似文献
15.
High prevalence of HPV 16 in South African women with cancer of the cervix and cervical intraepithelial neoplasia 总被引:9,自引:0,他引:9
Kay P Soeters R Nevin J Denny L Dehaeck CM Williamson AL 《Journal of medical virology》2003,71(2):265-273
Despite the high prevalence of cervical cancer and cervical neoplasias in South Africa, few studies have been performed in this region to establish which human papillomavirus (HPV) types are associated with the development of high-grade cervical intraepithelial neoplasia lesions and cervical cancer. To investigate these prevalence rates, punch biopsies were obtained from 56 women with cervical cancer and 141 women with histologically diagnosed cervical intraepithelial neoplasia 2 or 3 lesions. Nested polymerase chain reaction (PCR) using consensus degenerate PCR primers was performed for the detection of HPV DNA and HPV typing was done by restriction fragment length polymorphism. Forty-seven (94%) of the cervical cancer and 114 (88%) of the cervical intraepithelial neoplasia 2/3 biopsies were positive for HPV DNA. The prevalence rates of the HPV types detected in the cervical cancer biopsies were HPV 16 (82%), HPV 18, (10%), HPV 33 (10%), HPV 31 (2%), HPV 58 (2%), HPV 35 (2%), and HPV 59 (2%). The cervical intraepithelial neoplasia lesions contained HPV 16 (56.6%), HPV 33 (14%), HPV 31 (10.9%), HPV X (7%), HPV 52 (3.9), HPV 58 (3.1%), HPV 35 (2.3%), HPV 18 (1.6%), HPV 11 (0.8%). Five of the nine fragments that were not typed by the RFLP, designated HPV-X, were sequenced to give HPV6 (1/5), HPV 26 (2/5), HPV 68 (1/5), and candHPV 87 (1/5). HPV 58 was detected in one cervical cancer biopsy and four biopsies from cervical intraepithelial neoplasia grade 3 lesions and was shown to be a previously described variant [Williamson and Rybicki (1991) J. Med. Virol. 33:165-171]. In addition, a cervical intraepithelial neoplasia grade 2 lesion was shown to harbour HPV type HAN2294 (cand HPV 87). The results of this study indicate that cervical cancer and cervical intraepithelial neoplasia 2/3 are largely associated with HPV 16 infection in this group of South African women and, therefore, an effective HPV 16 based vaccine should prevent the development of cervical cancer in a large proportion of women from this region of South Africa. 相似文献
16.
Dimitrios I. Athanasiadis Sara Monfared Hamed Asadi Cameron L. Colgate Denny Yu Dimitrios Stefanidis 《Surgery》2021,169(3):496-501
BackgroundWork-related musculoskeletal injuries have been increasingly recognized to affect surgeons. It is unknown whether such injuries also affect surgical trainees. The purpose of this study was to assess the ergonomic risk of surgical trainees as compared with that of experienced surgeons.MethodsErgonomic data were recorded from 9 surgeons and 11 trainees. Biomechanical loads during surgery were assessed using motion tracking sensors and electromyography sensors. Demanding and static positions of the trunk, neck, right/left shoulder, as well as activity from the deltoid and trapezius muscles bilaterally were recorded. In addition, participants reported their perceived discomfort on validated questionnaires.ResultsA total of 87 laparoscopic general surgery cases (48 attendings and 39 trainees) were observed. Both trainees and attendings spent a similarly high percentage of each case in static (>60%) and demanding positions (>5%). Even though residents reported overall more discomfort, all participants shared similar ergonomic risk with the exception of trainees’ trunk being more static (odds ratio: –11.42, P = .006).ConclusionSurgeons are prone to ergonomic risk. Trainees are exposed to similar postural ergonomic risk as surgeons but report more discomfort and, given that musculoskeletal injuries are cumulative over time, the focus should be on interventions to reduce ergonomic risk in the operating room. 相似文献
17.
A series of substituted 2-phenylbenzimidazole-4-carboxamides has been synthesized and evaluated for in vitro and in vivo antitumor activity. These compounds represent the logical conclusion to our search for "minimal" DNA-intercalating agents with the lowest possible DNA-binding constants. Such "2-1" tricyclic chromophores, of lower aromaticity than the structurally similar 2-phenylquinolines, have the lowest DNA binding affinity yet seen in the broad series of tricyclic carboxamide intercalating agents. Despite very low in vitro cytotoxicities, several of the compounds had moderate levels of in vivo antileukemic effects. However, the most interesting aspect of their biological activity was the lack of cross-resistance shown to an amsacrine-resistant P388 cell line, suggesting that these compounds may not express their cytotoxicity via interaction with topoisomerase II. 相似文献
18.
19.
心脏直视手术围术期自体血回输335例的监护 总被引:2,自引:0,他引:2
0 引言 自体输血是采集患者体内血或回收自体失血,再输回同一患者,献血者与受血者为同一个体,既可以节约临床用血,减少患者费用,更重要是可以避免或减少同种输血传播感染性疾病.我科对335例体外循环心内直视手术患者实行自体血回输,收到较好的社会效益和经济效益.1 临床资料 1998-09/1999-02,我科心脏直视手术共445例,围术期采用自体输血335例,其中先心病226例,瓣膜手术59例,复杂心内畸形37例,冠心病、大血管13例,占同期体外循环心内直视手术75%.患者主要适应证:心脏及大血管外科手术,术前一般情况尚好,无肝、肾、呼吸功能障碍;术前检查… 相似文献
20.
Milbank JB Tercel M Atwell GJ Wilson WR Hogg A Denny WA 《Journal of medicinal chemistry》1999,42(4):649-658
A series of racemic 6-amino-seco-cyclopropylindole (seco-CI) compounds was prepared by coupling 1-(tert-butyloxycarbonyl)-3-(chloromethyl)-6-nitroindoline with appropriate acids, followed by nitro group reduction, and evaluated for cytotoxicity in AA8, UV4, EMT6, and SKOV3 cell lines. These compounds are of interest due to their close structural relationship to known AT-specific alkylating agents and cytotoxins and also for the possible construction of stable amine-based prodrugs designed for tumor-specific release. Variations included indole or furan side chains with different substituents, sulfonamide or carboxamide linkers, extension of the minor groove binding side chain to two subunits, and the use of a pyrroylacryloyl unit previously reported to give extremely potent analogues. The parent compound, with a trimethoxyindole side chain, was a moderately potent cytotoxin (IC50 = 0.34 microM in AA8 cells, 4 h exposure). A single 5-methoxy group on the indole minor groove binding unit was sufficient to maintain potency, and a series of dimethylaminoethoxy-substituted analogues retained the cytotoxicity of the parent compound, while providing increased aqueous solubility. 相似文献