全文获取类型
收费全文 | 2400篇 |
免费 | 158篇 |
国内免费 | 27篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 124篇 |
妇产科学 | 45篇 |
基础医学 | 362篇 |
口腔科学 | 36篇 |
临床医学 | 164篇 |
内科学 | 489篇 |
皮肤病学 | 75篇 |
神经病学 | 178篇 |
特种医学 | 87篇 |
外国民族医学 | 1篇 |
外科学 | 480篇 |
综合类 | 29篇 |
一般理论 | 1篇 |
预防医学 | 173篇 |
眼科学 | 57篇 |
药学 | 112篇 |
中国医学 | 1篇 |
肿瘤学 | 135篇 |
出版年
2021年 | 25篇 |
2020年 | 28篇 |
2019年 | 31篇 |
2018年 | 41篇 |
2017年 | 46篇 |
2016年 | 46篇 |
2015年 | 27篇 |
2014年 | 64篇 |
2013年 | 98篇 |
2012年 | 134篇 |
2011年 | 148篇 |
2010年 | 91篇 |
2009年 | 105篇 |
2008年 | 115篇 |
2007年 | 135篇 |
2006年 | 103篇 |
2005年 | 90篇 |
2004年 | 91篇 |
2003年 | 72篇 |
2002年 | 106篇 |
2001年 | 82篇 |
2000年 | 60篇 |
1999年 | 60篇 |
1998年 | 50篇 |
1997年 | 29篇 |
1996年 | 44篇 |
1995年 | 32篇 |
1994年 | 33篇 |
1993年 | 16篇 |
1992年 | 31篇 |
1991年 | 23篇 |
1990年 | 29篇 |
1989年 | 24篇 |
1988年 | 25篇 |
1987年 | 31篇 |
1986年 | 37篇 |
1985年 | 28篇 |
1984年 | 23篇 |
1983年 | 18篇 |
1979年 | 13篇 |
1978年 | 16篇 |
1975年 | 16篇 |
1974年 | 22篇 |
1973年 | 21篇 |
1972年 | 20篇 |
1971年 | 22篇 |
1970年 | 16篇 |
1969年 | 13篇 |
1968年 | 24篇 |
1966年 | 16篇 |
排序方式: 共有2585条查询结果,搜索用时 0 毫秒
1.
Michiel R. de Boer Jos Twisk Annette C. Moll Hennie J. M. Völker-Dieben Henrica C. W. de Vet Ger H. M. B. van Rens 《Ophthalmic & physiological optics》2006,26(6):535-544
Consecutive patients (n = 215) who were referred to optometric (55%) or multidisciplinary (45%) low-vision services and above 50 years of age were recruited from four hospitals in the Netherlands. They completed two vision-related quality of life questionnaires, the Vision Quality of Life Core Measure (VCM1) and the Low Vision Quality of Life Questionnaire (LVQOL), before their first visit with low-vision services and 1 year later. At follow-up, patients referred to multidisciplinary low-vision services had lower scores on the mobility subscale of the LVQOL than patients referred to optometric low-vision services [5.3 points; 95% confidence interval (CI): 0.2-10.5]. Paired sample t-tests for the two groups of patients taken together show improvement for the VCM1 (3.1 points; 95% CI: 0.6-5.6) and deterioration for the basic aspects of vision (3.5 points; 95% CI: 1.1-5.9) and the mobility (6.6 points; 95% CI: 3.7-9.5) subscales of the LVQOL. In conclusion, people referred to optometric services showed less deterioration in mobility than those referred to multidisciplinary services. No differences were observed for any of the other subscales of the LVQOL and the VCM1. Future research in this field should include randomized controlled designs comparing low-vision services with no treatment or placebo. 相似文献
2.
3.
R Mollà J M Garcia-Verdugo C López-Garcia V Martín-Perez 《Journal für Hirnforschung》1986,27(6):625-637
The neuronal morphological development of the avian telencephalic cortex (DMC) is studied in Golgi-stained brain sections. The neuronal types at embryonic days 10, 13, 16, as well as of newborn chick are identified. The immature neurons are characterized by the presence of hair-like processes, growth cones and dendritic varicosities. These characteristics are absent in neuronal types of newborn chick. There are five patterns of differentiation, which produce six neuronal types in the newborn chick: horizontal neurons, pyramidal neurons, bipyramidal neurons, short axon multipolar neurons, long axon multipolar neurons and periventricular neurons. The morphological features of migrating embryonic cells are described. The dendritic spines appear in 16-day embryos in the majority of neuronal types. 相似文献
4.
Work-related injuries in minors 总被引:6,自引:0,他引:6
S E Schober J L Handke W E Halperin M B Moll M J Thun 《American journal of industrial medicine》1988,14(5):585-595
Since 1938, federal child labor laws have restricted employment of persons under 18 years old, in part to protect them from hazardous occupations. Workers' compensation claims reported to the Supplementary Data System of the Bureau of Labor Statistics were examined to define the current status of occupational injuries among minors. Data tapes from 1980 to 1983 were searched to identify all current claims for injuries and illnesses occurring in 1980 in persons under age 18. Injury rates were calculated using information about employment in 1979 available from the 1980 census. In the 24 states included in this study, 23,823 claims were reported for persons less than 18 years old. Of these claims, approximately 10% were from persons under age 16. Rates of injuries in 16- and 17 year olds were 12.6 per 100 full-time male workers and 6.6 per 100 full-time female workers. Serious injuries included fractures, dislocations, and amputations, accounting for 5.8%, 0.7%, and 0.6% of cases, respectively. California, the only state that coded whether injuries resulted in fatalities, reported 12 deaths in this age group. Machines and vehicles, many of which are restricted under child labor laws, accounted for 8.3% and 5.8% of claims. These data suggest that persons under age 18 years are not adequately protected from occupational injury. Further attention and, possibly, new preventive strategies are needed. 相似文献
5.
A 2.5-year-old boy and a 2-month-old girl presented with fever without an apparent source. Additional laboratory tests were requested due to alarming signs for the presence of a serious bacterial infection. Pneumonia and viral meningitis respectively were diagnosed, and adequate therapy led to a quick and complete recovery. Due to changing prospects following the near eradication of invasive Haemophilus influenzae type b (Hib) infections by vaccination, there are no suitable guidelines at present concerning fever without an apparent source in children. A selection of patients at risk can first of all be made based on patient history and a physical examination and secondly by carrying out additional laboratory tests. Furthermore, careful evaluation, clinical acumen, well-informed parents and observation are all important elements in the treatment of these patients. 相似文献
6.
7.
An overview of diagnostic and therapeutic methods (techniques) of manual medicine (MM)/chirotherapy in the thoracic spine region is presented. The three schools of MM of the German Society of MM describe the methods taught in seminars for physicians. The authors distinguish between common, orienting and specific diagnostics and therapeutic approaches such as mobilisation of joints and muscles and manipulative treatment. Relations to other regions are considered. Diagnostics and therapeutic approaches to the cervicothoracic region and chest will be considered in further publications. 相似文献
8.
9.
Comparative genomic hybridization (CGH) discloses chromosomal and subchromosomal copy number changes in Merkel cell carcinomas 总被引:1,自引:0,他引:1
M. Härle N. Arens I. Moll W. Back T. Schulz H. Scherthan 《Journal of cutaneous pathology》1996,23(5):391-397
We analyzed three Merkel cell carcinomas (MCC), applying comparative genomic hybridization (CGH) with DNA from paraffin-embedded and cultured tumor material as the probes. By this method, numerous changes in chromosome copy numbers were observed in each tumor investigated. Recurrent gains of chromosomes 1, 6, 18q and 20 were detected in two tumors. A third tumor showed complex chromosomal copy number changes, including gain of chromosome 8 and 9. These gains, as well as gain of chromosome 1 in the first two tumors, were confirmed by fluorescence in situ hybridization to paraffin tissue sections. Our results support the view that important genes for MCC development may be located on chromosomes 1, 6, 18q and 20. 相似文献
10.
Expression of intermediate filament proteins in subtypes of renal cell carcinomas and in renal oncocytomas. Distinction of two classes of renal cell tumors 总被引:10,自引:0,他引:10
S Pitz R Moll S St?rkel W Thoenes 《Laboratory investigation; a journal of technical methods and pathology》1987,56(6):642-653
We examined the expression of the diverse cytokeratin (CK) polypeptides as well as vimentin in human renal cell carcinomas of various subtypes and in renal oncocytomas by applying both two-dimensional gel electrophoresis and immunocytochemistry by using polypeptide-specific monoclonal antibodies. The tumors were classified according to the guidelines of the World Health Organization, with some modifications based primarily on recently proposed cytomorphological criteria. All clear cell carcinomas (G I, G II; N = 20) co-expressed CKs nos. 8 and 18, and vimentin, with CK no. 19 being present in 13 of the 20 cases and exhibiting a heterogeneous distribution. Dedifferentiated carcinomas (G III; N = 8) also co-expressed CKs nos. 8 and 18 as well as vimentin, but in addition, exhibited CK no. 19 and, in many cases, CK no. 7; in 1 case, only vimentin was expressed. Both eosinophilic-granular (N = 3) and basophilic (small cell cuboidal; N = 6) carcinomas contained CKs nos. 8 and 18, and the co-expression of vimentin was a consistent feature of these tumors; CK no. 19 was found in all of these cases, while CK no. 7 was present in the majority. In chromophobe cell carcinomas (N = 8), in contrast to all of the other carcinoma types, no vimentin was detected in the tumor cells, with only CKs nos. 8, 18, and to a variable extent 7, being present. Similarly, oncocytomas (N = 8) lacked vimentin and exhibited only CKs nos. 8 and 18. Conspicuous scattered CK no. 19-positive cells were found in these two last tumor types. No CK polypeptides other than simple-epithelium-type CKs (nos. 7, 8, 18, and 19) were detected in any of the tumors studied. These results indicate that, in renal cell tumors, the expression of intermediate-filament proteins is strikingly correlated with the specific morphologic appearance. While the co-expression of CKs nos. 8 and 18 and vimentin was a surprisingly consistent feature of the most common subtypes of renal cell carcinomas, CK no. 19 exhibited remarkable heterogeneity of expression both within individual tumors and between different tumors, the expression patterns of this CK being correlated to the tumor subtypes. The consistent absence of vimentin in chromophobe cell carcinomas and oncocytomas makes it possible to define these as a separate class of renal cell tumors. This finding supports the view that chromophobe cell carcinomas represent a distinct tumor entity and points to their close phenotypic relationship to benign oncocytomas as well as to normal renal tubules. 相似文献