全文获取类型
收费全文 | 2413篇 |
免费 | 182篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 15篇 |
儿科学 | 130篇 |
妇产科学 | 124篇 |
基础医学 | 361篇 |
口腔科学 | 36篇 |
临床医学 | 192篇 |
内科学 | 511篇 |
皮肤病学 | 102篇 |
神经病学 | 345篇 |
特种医学 | 55篇 |
外科学 | 185篇 |
综合类 | 8篇 |
预防医学 | 216篇 |
眼科学 | 19篇 |
药学 | 110篇 |
中国医学 | 2篇 |
肿瘤学 | 190篇 |
出版年
2023年 | 20篇 |
2022年 | 27篇 |
2021年 | 85篇 |
2020年 | 51篇 |
2019年 | 83篇 |
2018年 | 75篇 |
2017年 | 52篇 |
2016年 | 64篇 |
2015年 | 67篇 |
2014年 | 111篇 |
2013年 | 111篇 |
2012年 | 194篇 |
2011年 | 178篇 |
2010年 | 105篇 |
2009年 | 83篇 |
2008年 | 146篇 |
2007年 | 159篇 |
2006年 | 125篇 |
2005年 | 155篇 |
2004年 | 120篇 |
2003年 | 111篇 |
2002年 | 115篇 |
2001年 | 51篇 |
2000年 | 42篇 |
1999年 | 28篇 |
1998年 | 21篇 |
1997年 | 15篇 |
1996年 | 12篇 |
1995年 | 14篇 |
1994年 | 11篇 |
1993年 | 13篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 14篇 |
1986年 | 5篇 |
1985年 | 15篇 |
1984年 | 5篇 |
1983年 | 10篇 |
1981年 | 6篇 |
1980年 | 4篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1973年 | 4篇 |
1972年 | 6篇 |
1971年 | 3篇 |
1970年 | 3篇 |
1967年 | 3篇 |
排序方式: 共有2601条查询结果,搜索用时 921 毫秒
1.
2.
ImmunoCyt/uCyt is a fluorescent test combining three monoclonal antibodies. In this study, it has been tested as a complement to cytology in the detection of urothelial carcinoma in urine. It has been performed simultaneously with standard cytology and cystoscopy on 870 urine analyses from one hospital. In 136 cases, one or more bladder tumors were found. Overall sensitivity of cytology, ImmunoCyt/uCyt and combined analyses reached 29, 74 and 84%, respectively, and overall specificity was 98, 62 and 61%. The negative predictive value of cytology, ImmunoCyt/uCyt and both analyses was 88, 93 and 95%, respectively, and the positive predictive value was 70, 26 and 29%. The sensitivity of cytology for low malignant potential neoplasms, low- and high-grade papillary carcinomas was 6, 18 and 53%, while it reached 71, 79 and 93% when combined with ImmunoCyt/uCyt. The sensitivity of cytology for stages Ta, T1, T2 and over and Tis tumors was 12, 67, 47 and 50%, while it reached 78, 83, 79 and 100% when combined with ImmunoCyt/uCyt. In the absence of tumor on cystoscopy but with positive ImmunoCyt/uCyt, 18% of patients developed a tumor, 2-6 months later. Of the 109 cases diagnosed as suspicious for malignancy by cytology, a tumor was present in 30 cases and ImmunoCyt/uCyt was positive in 22 (73%) of them. In conclusion, ImmunoCyt/uCyt may be used to postpone cystoscopies in patients followed for bladder cancer and may help to save cytologist and pathologist screening time. 相似文献
3.
4.
5.
Athena Milatovich Graeme Bolger Tamar Michaeli Uta Francke 《Somatic Cell and Molecular Genetics》1994,20(2):75-86
Cyclic nucleotides are important second messengers that mediate a number of cellular responses to external signals. Cyclic nucleotide phosphodiesterases play a role in signal transduction by regulating the cellular concentrations of these messengers. Here, we have applied Southern analyses of somatic cell hybrid lines and of recombinant inbred (RI) mouse strains as well as fluorescence chromosomal in situ hybridization (FISH) to chromosomally localize five cAMP-specific nucleotide phosphodiesterase genes in human and mouse. GenesDPDE1, DPDE2, DPDE3, andDPDE4 that share sequence homology with theDrosophila dunce gene were assigned to human chromosomes 19 (DPDE1 andDPDE2), 5q12 (DPDE3), and 1p31 (DPDE4) and to mouse chromosomes 8, 9, 13, and 4, respectively. The high-affinity cAMP-specific phosphodiesterase gene (HCP1) was mapped to human chromosome 8q13-q22. Since these genes are potential candidates for involvement in psychiatric or behavioral disorders, knowledge of their chromosomal localizations will facilitate the discovery of their association with disease genes as they are being mapped by linkage studies. 相似文献
6.
The effects of anesthesia on otoacoustic emissions 总被引:4,自引:0,他引:4
Noam Harel Akinobu Kakigi Haruo Hirakawa Richard J. Mount Robert V. Harrison 《Hearing research》1997,110(1-2):25-33
We have measured transient-evoked and distortion-product otoacoustic emissions (OAEs) in the chinchilla and compared them in the awake and anesthetized animal (using either ketamine or barbiturate agents). We report a significant increase in OAE amplitudes during anesthesia, particularly using ketamine. These effects are most evident for transient-evoked otoacoustic emissions (TEOAEs) as measured in the non-linear mode. Our data support the hypothesis that tonic activity levels in cochlear efferents may be reduced by anesthetic effects, either directly or indirectly (e.g., by general reductions in descending pathway activity), and that reduced cochlear efferent activity will result in the observed increase of OAE amplitudes. 相似文献
7.
Mary Arevian Samar Noureddine Tamar Kabakian-Khasholian 《Journal of transcultural nursing》2006,17(4):357-364
Women need to practice cervical screening regularly to reduce morbidity and mortality. The purpose of this study was to examine the impact of an intervention program on knowledge, attitude, and practice of cervical screening in the population of Lebanese/Armenian women. The design was a cross-sectional, quasi-experimental posttest survey following a year long intervention program. The sample included 176 women, who were members of the Armenian Relief Cross in Lebanon. Interventions consisted of educational classes, media messages, and free screening. The instrument was a self-administered questionnaire. Knowledge of women with intervention was higher (p > .05) and practice rate increased between intervention and comparison groups. No difference in attitude was noted. The study was successful in raising awareness and increasing screening in the sample. It is recommended to continue helping women to overcome barriers for cervical screening. 相似文献
8.
Dezfulian H Batisson I Fairbrother JM Lau PC Nassar A Szatmari G Harel J 《Journal of clinical microbiology》2003,41(4):1375-1385
The virulence genotype profile and presence of a pathogenicity island(s) (PAI) were studied in 18 strains of F165-positive Escherichia coli originally isolated from diseased calves or piglets. On the basis of their adhesion phenotypes and genotypes, these extraintestinal pathogenic strains were classified into three groups. The F165 fimbrial complex consists of at least two serologically and genetically distinct fimbriae: F165(1) and F165(2). F165(1) is encoded by the foo operon (pap-like), and F165(2) is encoded by fot (sfa related). Strains in group 1 were foo and fot positive, strains in group 2 were foo and afa positive, and strains in group 3 were foo positive only. The strains were tested for the presence of virulence genes found mainly in extraintestinal pathogenic E. coli (ExPEC) strains. Although all the strains were positive for the papA variant encoding F11 fimbriae incD, traT, and papC, the prevalence of virulence genes commonly found in PAIs associated with ExPEC strains was highly variable, with strains of group 2 harboring most of the virulence genes tested. papG allele III was detected in all strains in group 1 and in one strain in group 3. All other strains were negative for the known alleles encoding PapG adhesins. The association of virulence genes with tRNA genes was characterized in these strains by using pulsed-field gel electrophoresis and DNA hybridization. The insertion site of the foo operon was found at the pheU tRNA locus in 16 of the 18 strains and at the selC tRNA locus in the other 2 strains. Furthermore, 8 of the 18 strains harbored a high-pathogenicity island which was inserted in either the asnT or the asnV/U tRNA locus. These results suggest the presence of one or more PAIs in septicemic strains from animals and the association of the foo operon with at least one of these islands. F165-positive strains share certain virulence traits with ExPEC, and most of them are pathogenic in piglets, as tested in experimental infections. 相似文献
9.
Giorgadze T Ward RM Baloch ZW LiVolsi VA 《Archives of pathology & laboratory medicine》2002,126(10):1233-1236
We present a case of a malignant phyllodes tumor metastasizing to a Hürthle cell adenoma of the thyroid. A 55-year-old woman underwent mastectomy for a malignant phyllodes tumor. Two years later, she presented with a left thyroid mass, which was a single, circumscribed, soft, deep red-brown nodular lesion with an eccentric area of firmer consistency. Histologically, the thyroid tumor was composed of 2 distinct types of cellular proliferation. Atypical spindle cells were infiltrating between the Hürthle cell cords and follicles in a fibrosarcomatous pattern. A battery of immunohistochemical stains was applied to both the thyroid and breast tumors for comparison. Based on the histologic and immunophenotypic features of the fibrosarcomatous components of both the breast and thyroid tumors, we rendered a diagnosis of cystosarcoma phyllodes metastatic to Hürthle cell adenoma. To the best of our knowledge, this unusual case is a first report of tumor-to-tumor metastasis of a sarcoma to a primary thyroid neoplasm. 相似文献
10.
Einat Rabinovitch Dror Harats Pnina Yaron Tamar Luvish Merav Lidar Ron Kedem Aviv Shaish Issahar Ben-Dov Avi Livneh 《Annals of allergy, asthma & immunology》2007,99(6):517-521
BACKGROUND: Asthma is an inflammatory airway disease caused by interaction between susceptibility genes and diverse environmental factors. In Israel, asthma seems to be familial and more severe in patients of Iraqi Jewish descent. On the other hand, asthma is less frequent in individuals with familial Mediterranean fever, an autoinflammatory disease prevalent in the Iraqi Jewish community and linked to mutations in the familial Mediterranean fever gene, designated MEFV. OBJECTIVES: To explore a possible role for mutated MEFV in the reduced susceptibility to asthma and to determine its expression in Israeli subjects of Iraqi origins. METHODS: Using a case-control approach, we studied the presence of the 3 most common MEFV mutations (M694V, V726A, and E148Q) in DNA samples from 75 patients with asthma and 45 asymptomatic first-degree relatives, all of Iraqi Jewish origin. The severity of asthma was evaluated using a published severity score. RESULTS: Eleven patients with asthma and 14 of their relatives carried 1 or 2 mutations in the MEFV gene, a carrier rate significantly lower in patients with asthma than in their first-degree relatives and in ethnically matched healthy individuals (P < .03 and P < .003, respectively). Carriers of MEFV mutations had less severe disease, compared with noncarriers (P < .002). CONCLUSION: These findings suggest that MEFV mutations may have a protective effect in the pathogenesis of asthma. 相似文献