全文获取类型
收费全文 | 1105篇 |
免费 | 70篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 86篇 |
妇产科学 | 19篇 |
基础医学 | 373篇 |
口腔科学 | 2篇 |
临床医学 | 65篇 |
内科学 | 322篇 |
皮肤病学 | 4篇 |
神经病学 | 11篇 |
特种医学 | 3篇 |
外科学 | 30篇 |
综合类 | 58篇 |
预防医学 | 11篇 |
眼科学 | 6篇 |
药学 | 12篇 |
肿瘤学 | 180篇 |
出版年
2023年 | 6篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 19篇 |
2019年 | 19篇 |
2018年 | 17篇 |
2017年 | 18篇 |
2016年 | 22篇 |
2015年 | 23篇 |
2014年 | 35篇 |
2013年 | 49篇 |
2012年 | 31篇 |
2011年 | 39篇 |
2010年 | 27篇 |
2009年 | 46篇 |
2008年 | 45篇 |
2007年 | 44篇 |
2006年 | 40篇 |
2005年 | 44篇 |
2004年 | 47篇 |
2003年 | 51篇 |
2002年 | 50篇 |
2001年 | 41篇 |
2000年 | 32篇 |
1999年 | 41篇 |
1998年 | 43篇 |
1997年 | 49篇 |
1996年 | 41篇 |
1995年 | 41篇 |
1994年 | 27篇 |
1993年 | 24篇 |
1992年 | 23篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 10篇 |
1987年 | 10篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 3篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1975年 | 5篇 |
1969年 | 1篇 |
排序方式: 共有1184条查询结果,搜索用时 15 毫秒
1.
Timson C Appanna Shareen H Doak Spencer A Jenkins Howard G Kynaston Timothy P Stephenson James M Parry 《International journal of urology》2007,14(6):539-544
OBJECTIVE: Tumors arising within augmentation cystoplasties are aggressive, have poor prognosis and the majority are not detected at follow-up cystoscopy. Genetic changes in tumors precede morphological abnormalities. Therefore, the aim of this study was to investigate whether genetic abnormalities detected by comparative genomic hybridization (CGH) could be used to identify those patients with augmentation cystoplasties at increased risk of tumorigenesis. METHODS: Bladder biopsy samples were obtained from 16 augmentation cystoplasty patients both distant from and near to the enterovesical anastomosis. CGH was used to detect genetic abnormalities in DNA extracted from the biopsies, archival specimens of two augmentation cystoplasties and two de novo bladder adenocarcinomas. RESULTS: A greater number of amplifications on 2p, 3q, 8q, 9p, 17p, 18pq and 20pq, were observed in bladder biopsies obtained near to the enterovesical anastomosis compared to those taken distant to the suture line. CGH of archival augmentation cystoplasty tumor DNA indicated abnormalities at several loci with amplifications at 2q, 5q, 10p and 21pq, while deletions occurred at 5p and 16p. CONCLUSIONS: The results of this study suggest that the urothelium adjacent to the bladder and/or bowel anastomosis in augmentation cystoplasties is genetically unstable. Furthermore, longitudinal studies are required to establish whether or not patients exhibiting genetic instability following augmentation cystoplasty are at greater risk of developing tumors than those with genetically stable epithelia. 相似文献
2.
M L Cibull M E Thompson L Smith C D Jennings M A Doukas E J Pavlik D E Powell 《American journal of hematology》1987,24(3):293-299
The emergence of a near-haploid clone of cells in blast phase chronic myelogenous leukemia is an unusual event. We report such a case and review eight other cases described in the English literature. The significance of the substantial loss of genetic material is discussed as is the phenotypic and genotypic heterogeneity observed in this group of patients. 相似文献
3.
Arnold Criel Gregor Verhoef Robert Vlietinck Cristina Mecucci Johan Billiet Lucienne Michaux Peter Meeus ries Louwagie Angeline Van Orshoven Achiel Van Hoof Mark Boogaerts Herman Van den Berghe & Chris De Wolf-Peeters 《British journal of haematology》1997,97(2):383-391
We analysed a group of 390 patients, diagnosed with chronic lymphocytic leukaemia (CLL). Cases were subclassified as morphologically typical and atypical CLL according to the criteria of the FAB proposal. Typical CLL cases were mostly diagnosed at a low-risk stage (Binet A/Rai 0), required no immediate treatment and expected a long survival; atypical CLL cases mostly presented at a more advanced risk stage (Binet B/Rai I–II), usually required immediate treatment and their survival was shorter. Moreover, clinical staging was of prognostic significance in typical but not in atypical cases. In typical CLL, del(11q) was the most common chromosomal abnormality (21%) whereas in atypical CLL trisomy 12 was found in about 65% of the cases documented with an abnormal karyotype. Although chromosomal abnormalities were associated with a poor survival in typical CLL, they are of no prognostic significance in atypical CLL. Based on these data, we conclude that subtyping CLL by morphology enables the identification of two groups of cases, each characterized by a specific clinical presentation, different cytogenetic abnormalities and prognostic parameters. We speculate that these two groups may represent two related, but different, diseases with different prognostic parameters and a different survival. 相似文献
4.
5.
6.
Unpublished results from our laboratory showed that colchicine increased the incidence of hyperploid mouse metaphase II (MII) oocytes when injected at the same time as human chorionic gonadotrophin (HCG). The objective of the present study was to determine whether the time of administering colchicine influenced the incidence of aneuploidy in MII oocytes. CD-1 mice were given pregnant mare's serum (PMS) and 48 hr later, HCG. An intraperitoneal injection of 0.2 mg/kg colchicine was given at +4, +2, 0, -2, or -4 hr relative to HCG. Oocytes were collected 17 hr post-HCG and processed, and chromosomes were subsequently C-banded. The percentage of hyperploid oocytes was 0.77, 2.56, 5.71, 7.79, 3.54, and 2.70 for control, +4, +2, 0, -2, or -4 hr pre/post-HCG, respectively. Chi-square analyses of these data demonstrated that colchicine significantly increases the proportion of aneuploid oocytes, and that the relative sensitivity of colchicine-induced aneuploidy depends upon the time that this drug is administered relative to HCG. 相似文献
7.
The phylogeny of howler monkeys (Alouatta, Platyrrhini): Reconstruction by multicolor cross-species chromosome painting 总被引:2,自引:0,他引:2
Edivaldo H. C. de Oliveira Michaela Neusser Wilsea B. Figueiredo Cleusa Nagamachi Julio Cesar Pieczarka Ives J. Sbalqueiro Johannes Wienberg Stefan Müller 《Chromosome research》2002,10(8):669-683
We performed multidirectional chromosome painting in a comparative cytogenetic study of the three howler monkey species Alouatta fusca, A. caraya and A. seniculus macconnelli (Atelinae, Platyrrhini) in order to reconstruct phylogenetic relationships within this genus. Comparative genome maps between these species were established by multicolor fluorescence in-situ hybridization (FISH) employing human, Saguinus oedipus and Lagothrix lagothricha chromosome-specific probes. The three species included in this study and previously analyzed howler monkey species were subjected to a phylogenetic analysis on the basis of a data matrix comprised of 98 discrete molecular cytogenetic characters. The results revealed that howler monkeys represent the genus with the most extensive karyotype diversity within Platyrrhini so far analyzed with high levels of intraspecific chromosomal variability. Two different multiple sex chromosome systems were identified. The phylogenetic analysis indicated that Alouatta is a monophyletic clade which can be derived from a proposed ancestral Atelinae karyotype of 2n=62 chromosomes by a chromosome fusion, a fission, a Y-autosomal translocation and a pericentric inversion. Following these suggestions, the genus Alouatta can be divided into two distinct species groups: the first includes A. caraya and A. belzebul, the second A. s. macconnelli, A. sara, A. s. arctoidea and A. fusca. 相似文献
8.
郑春兰 《牡丹江医学院学报》2002,23(6)
目的 :探讨福建莆田遗传咨询者的医学细胞遗传学主要特征。方法 :采用细胞遗传学方法对 739例遗传咨询者进行外周血淋巴细胞检查。结果 :739例遗传咨询者中发现染色体异常 5 6例 ,异常率为 7.5 8% ,其中常染色体数目结构异常 4 3例 ,占 76 .9% ,性染色体异常 13例 ,占 2 3.1%。结论 :智力低下、不良孕产史、性发育异常与遗传染色体异常密切相关 ,不良孕产史推出异常核型率 3.31% ,较正常群体的 0 .5 %显著性增高 ,与文献报道基本符合 相似文献
9.
Mayumi Matsuta Yuko Imamura Morimasa Matsuta Saiichi Kon Kohsuke Sasaki 《The Journal of dermatology》1994,21(1):14-19
We have applied DNA flow cytometric analysis to paraffin-embedded tissue sections of primary malignant melanomas. Conventionally, flow cytometric analysis of paraffin-embedded tissue sections has been done by the method of Hedley et al. We added ultrasound treatment to the method of Hedley et al. and a lower value of coefficient of variation was shown. Furthermore, a new technique, fluorescence in situ hybridization with a chromosome-specific repetitive DNA probe, was used for the analysis of chromosomal numerical aberrations in the same paraffin-embedded tissue sections. The DNA flow cytometric analysis showed that in 8 cases six primary malignant melanomas were of the aneuploid pattern and two cases of lentigo maligna (melamona in situ) were of the diploid pattern. By fluorescence in situ hybridization, the two cases with the diploid pattern had spots/nucleus of 1.28 and 1.12, and those with the aneuploid pattern had spots/nucleus from 2.01 to 2.27. Only one nodular melanoma in an aneuploid case showed spots/nucleus of 1.71. These data indicate that fluorescence in situ hybridization with chromosome-specific repetitive DNA probes can serve as a cytogenetic tool for the analysis of interphase nuclei of solid human tumors and may be useful for the study of tumor cell heterogeneity. 相似文献
10.
应用细胞遗传学和皮纹分析方法对142例先天性智能发育不全患儿进行了研究。其中,120例正常核型,22例异常核型。异常核型46,XY,t(1;3;21)(1pter→1q32.1∶∶21p11.2→21qter;3 qter→3p26.2∶∶1 q32.1→1 qter)和45,X/45,X,-22,+der(22)t(Y;22)(22qter→22p11.1∶∶Yq11.1→Yq11.2)两种核型国内尚未见报道。皮纹分析结果表明56.7%的患者有1项以上异常皮纹;染色体异常患者均有2项以上异常皮纹;先天愚型患者有“特定”的皮纹改变。 相似文献