全文获取类型
收费全文 | 1532篇 |
免费 | 178篇 |
国内免费 | 95篇 |
专业分类
耳鼻咽喉 | 17篇 |
儿科学 | 19篇 |
妇产科学 | 6篇 |
基础医学 | 172篇 |
口腔科学 | 17篇 |
临床医学 | 86篇 |
内科学 | 247篇 |
皮肤病学 | 7篇 |
神经病学 | 71篇 |
特种医学 | 144篇 |
外科学 | 19篇 |
综合类 | 167篇 |
预防医学 | 320篇 |
眼科学 | 21篇 |
药学 | 187篇 |
3篇 | |
中国医学 | 235篇 |
肿瘤学 | 67篇 |
出版年
2024年 | 7篇 |
2023年 | 18篇 |
2022年 | 66篇 |
2021年 | 115篇 |
2020年 | 63篇 |
2019年 | 39篇 |
2018年 | 38篇 |
2017年 | 51篇 |
2016年 | 65篇 |
2015年 | 68篇 |
2014年 | 113篇 |
2013年 | 124篇 |
2012年 | 97篇 |
2011年 | 112篇 |
2010年 | 80篇 |
2009年 | 53篇 |
2008年 | 73篇 |
2007年 | 81篇 |
2006年 | 58篇 |
2005年 | 47篇 |
2004年 | 54篇 |
2003年 | 45篇 |
2002年 | 41篇 |
2001年 | 32篇 |
2000年 | 27篇 |
1999年 | 23篇 |
1998年 | 22篇 |
1997年 | 21篇 |
1996年 | 8篇 |
1995年 | 20篇 |
1994年 | 11篇 |
1993年 | 9篇 |
1992年 | 11篇 |
1991年 | 15篇 |
1990年 | 14篇 |
1989年 | 11篇 |
1988年 | 7篇 |
1987年 | 8篇 |
1986年 | 4篇 |
1985年 | 18篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 1篇 |
1981年 | 7篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 2篇 |
排序方式: 共有1805条查询结果,搜索用时 31 毫秒
1.
BARI NUHOLU ALI AYYILDIZ VECIHI FIDAN ÖZDEN CEBECI UUR KOAR CANKON GERMIYANOLU 《International journal of urology》2006,13(2):109-110
OBJECTIVE: Nocturnal enuresis is a common pediatric problem, the etiology of which is unclear. In recent years, various studies have been published stating that children with nocturnal enuresis exhibit growth and skeletal maturation retardation. METHODS: In this cross-sectional study, we included 27 patients (16 boys, 11 girls) between the ages of 6 and 14 years who had presented with primary nocturnal enuresis (PNE) complaints. We included in the evaluation 19 healthy subjects (12 boys, 7 girls), who were the siblings of the children with PNE, as the control group. RESULTS: The patients in both groups were similar in chronological age, bone age, height and weight, with no significant difference between groups (P>0.05). CONCLUSION: The two groups in our study consisted of the same genetic background. Thus, our results were found to be different from the previous studies. We have concluded that there is no direct relationship between enuresis nocturnal and skeletal maturation. 相似文献
2.
Uta Lichter-Konecki Christian Benninger Werner E. Brandeis Peter Matthis Dieter Scheffner 《Pediatric hematology and oncology》1987,4(1):77-85
Thirteen children with acute lymphoblastic leukemia (ALL) were investigated before and during cytotoxic therapy. EEG findings were correlated with the clinical course and the therapy protocol and compared with normal data obtained from 295 healthy children. Frequency analysis of the background activity of the EEG revealed an initial slowing of the background activity prior to therapy and further slowing each time a combination of vincristine (VCR), daunorubicine (DAU) or adriblastine (ADR), prednisone (FRED), and L-asparaginase (L-ASP) was administered. The slowing of the background activity correlated only with the administration of these drugs. DAU, ADR, and FRED are not known to influence the EEG; therefore, VCR and L-ASP remain the primary candidates responsible for the central nervous system alteration. 相似文献
3.
用放射化学分析方法,对新疆核试验场周围10个调查区和远离核试验场位于上风向的5个对照区采取的土壤样品进行了90Sr、137Cs分析测定。核试验场周围调查区土壤中90Sr累积平均沉降量为1.5×103Bqm-2,137Cs为4.9×103Bqm-2;对照区90Sr累积平均沉降量为1.3×103Bqm-2,137Cs为3.9×103Bqm-2。调查区和对照区表层土壤中州90Sr,137Cs放射性平均水平无显著性差异。通过估算得出了调查区90Sr、137Cs对居民产生约定有效剂量当量分别为78.3μSv(集体剂量当量负担为23.9人·sv)和270μSv(集体剂量当量负担为82.3人·sv),对照区分别为70.5μSv,(集体剂量当量负担为14.1人·sv)和220μSv(集体剂量当量负担为14.1人·sv)。两个地区居民受到来自核试验产生的90Sr和137Cs给予人体的内照射剂量当量负担基本上是一样的。可认为90Sr、137Cs对新疆核试验场周围没有造成严重的局部污染。对居民的身体健康不致于产生不良影响。 相似文献
4.
Krzysztof Ulfig Marek Korcz 《International journal of environmental health research》1994,4(4):244-253
The qualitative and quantitative (q/q) changes of keratinolytic fungi in soil mixtures with added sewage sludge were examined during a preliminary reclamation experiment. Sludge before land application was characterized by the weak growth of keratinolytic fungi. In devastated urban soil, abundant fungal growth was observed. Over a 19‐month reclamation period, decreasing frequency of Chrysosporium concurrent with the enrichment of the mixture with the geophilic dermatophytes Arthroderma quadrifidum and A. uncinatum were clearly seen. The results are discussed with respect to possible ecological factors influencing the occurrence of keratinolytic fungi in the materials examined. The public health risk associated with the application of sewage sludge for reclamation is also discussed. 相似文献
5.
以湖北省78个县、市为研究对象,用单因素及多因素分析方法探讨了土壤、地质因素与胃癌死亡率的关系,直线相关分析表明与胃癌死亡率有显著性相关(双侧检验,P<0.05)的因素有:变质岩(r=0.6021)、酸性土(r=0.3751)、沉积岩(r=-0.2939)、砂土(r=0.2786)、碱性土(r=-0.2686)和二迭系地层(r=-0.2502)等6个因素;逐步回归分析表明在α=0.05时,变质岩、第三系地层和中性土三因素被选入回归方程,结合多元线性回归分析可知此三因素是与胃癌死亡率线性相关的主要因素。 相似文献
6.
城市污水致突变物活性及其土壤净化 总被引:1,自引:0,他引:1
城市污水及处理出水均程度不同地含有致突物质,其含量在枯水期高于丰水期。污灌区浅层地下水浓集物呈致突变性,而季节变化与原污水同步。浅层地下水GC/MS检测出31种有机化合物,基本与污水一致。实验证明土壤微生物对污水致突物有一定的降解作用。为避免污灌区浅层地下水的污染,污水在灌溉之前必须加强处理,使减少致突物至土壤降解能力所能承受的程度。 相似文献
7.
本文探讨了广东滨海沙土中微量元素B、Mo、Mn、Cu、Zn与木麻黄生长的关系,结果表明:B、Mo有利于促进生长与抗病,Cu含量高对生长有抑制作用,其余的作用不明显。 相似文献
8.
Takeichi N Fukushima J Kurkin S Yamanobe T Shinmei Y Fukushima K 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2003,149(3):380-390
The smooth pursuit system moves the eyes in space accurately while compensating for visual inputs from the moving background
and/or vestibular inputs during head movements. To understand the mechanisms underlying such interactions, we examined the
influence of a stationary textured visual background on smooth pursuit tracking and compared the results in young and adult
humans and monkeys. Six humans (three children, three adults) and six macaque monkeys (five young, one adult) were used. Human
eye movements were recorded using infrared oculography and evoked by a sinusoidally moving target presented on a computer
monitor. Scleral search coils were used for monkeys while they tracked a target presented on a tangent screen. The target
moved in a sinusoidal or trapezoidal fashion with or without whole body rotation in the same plane. Two kinds of backgrounds,
homogeneous and stationary textured, were used. Eye velocity gains (eye velocity/target velocity) were calculated in each
condition to compare the influence of the textured background. Children showed asymmetric eye movements during vertical pursuit
across the textured (but not the homogeneous) background; upward pursuit was severely impaired, and consisted mostly of catch-up
saccades. In contrast, adults showed no asymmetry during pursuit across the different backgrounds. Monkeys behaved similarly;
only slight effects were observed with the textured background in a mature monkey, whereas upward pursuit was severely impaired
in young monkeys. In addition, VOR cancellation was severely impaired during upward eye and head movements, resulting in residual
downward VOR in young monkeys. From these results, we conclude that the directional asymmetry observed in young primates may
reflect a different neural organization of the vertical, particularly upward, pursuit system in the face of conflicting visual
and vestibular inputs that can be associated with pursuit eye movements. Apparently, proper compensation matures later.
Electronic Publication 相似文献
9.
10.
AIM: Digital imaging is useful in conventional photography because it immediately provides images, and the image quality can be improved afterwards by the use of computer programs. The major disadvantages of consumer-type digital cameras mounted on microscopes are (i) unequal illumination through the image, and (ii) a coloured background. A computer program was specifically adapted and refined to improve images obtained with consumer-type digital cameras mounted on microscopes. METHODS AND RESULTS: An approach using a division operation between the specimen image and a background image leads to homogeneous illumination throughout the image, with automatically corrected brightness and white background. The correct colour spectrum is preserved by correction of the histogram. This approach was obtained from the freeware computer program 'Image Arithmetic'. In a test, three different consumer-type digital cameras (Sony, Nikon, Olympus) on different microscopes were used to obtain images of different types of histological specimens (cervical smear, bone marrow biopsy, and colonic biopsy). The computer program dramatically improved the quality of images obtained with all tested cameras. CONCLUSION: Using this approach, even low-cost digital cameras mounted on microscopes produce brilliant images with homogeneous illumination and a white background, the image quality being comparable with expensive cameras especially designed for microscopes. 相似文献