全文获取类型
收费全文 | 706篇 |
免费 | 38篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 32篇 |
妇产科学 | 5篇 |
基础医学 | 59篇 |
口腔科学 | 34篇 |
临床医学 | 56篇 |
内科学 | 134篇 |
皮肤病学 | 22篇 |
神经病学 | 48篇 |
特种医学 | 117篇 |
外科学 | 82篇 |
综合类 | 25篇 |
预防医学 | 38篇 |
眼科学 | 5篇 |
药学 | 53篇 |
中国医学 | 1篇 |
肿瘤学 | 39篇 |
出版年
2024年 | 1篇 |
2021年 | 16篇 |
2020年 | 8篇 |
2019年 | 15篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 14篇 |
2015年 | 16篇 |
2014年 | 18篇 |
2013年 | 31篇 |
2012年 | 38篇 |
2011年 | 26篇 |
2010年 | 31篇 |
2009年 | 35篇 |
2008年 | 22篇 |
2007年 | 20篇 |
2006年 | 34篇 |
2005年 | 17篇 |
2004年 | 24篇 |
2003年 | 18篇 |
2002年 | 14篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 20篇 |
1998年 | 35篇 |
1997年 | 26篇 |
1996年 | 24篇 |
1995年 | 14篇 |
1994年 | 23篇 |
1993年 | 25篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 7篇 |
1989年 | 13篇 |
1988年 | 16篇 |
1987年 | 10篇 |
1986年 | 14篇 |
1985年 | 7篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 12篇 |
1978年 | 4篇 |
1977年 | 5篇 |
1976年 | 9篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1957年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有752条查询结果,搜索用时 15 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.
3.
Outbreaks of vesicular stomatitis, serotype New Jersey, during epidemics in the United States and northern Mexico, 1982-5, were examined by backward trajectories of winds to investigate spread and possible sources. The outbreaks selected for analysis did not involve introduction of disease by infected animals. The findings indicate that wind could have been responsible for carrying infection from northern Mexico to Arizona and New Mexico and thence to Colorado and Utah and on to Wyoming, Idaho and Montana. The results of these analyses are consistent with the findings from T1 RNAse fingerprinting of virus isolates from outbreaks during the epidemics. The arrival of the trajectories was associated with the passage of a front and rain or passage of a front alone or rain alone. At the time of the trajectories temperatures of 10 degrees C and higher were recorded at heights up to 2500-3500 m. Introduction by airborne particles would appear unlikely as it would have required a source of at least 10(5) infectious units per minute per animal. Vesicular stomatitis virus had been isolated from Simulium and Culicoides during the epidemic with amounts of virus from Simulium sufficient to suggest biological transmission. The possibility of Simulium infected with vesicular stomatitis virus being carried downwind to introduce disease is discussed in relation to the behaviour of Simulium and the pathogenesis of vesicular stomatitis in large animals. 相似文献
4.
AR Jones BSC AJP Sandison FRCS WJ Owen MS FRCS 《International journal of clinical practice》1997,51(5):294-295
Pre-clerking of all patients undergoing elective general surgical operations was introduced at our hospital in an attempt to reduce an unacceptably high operation cancellation rate. A prospective audit has been performed on the effect of this policy on the cancellation rate. Before the introduction of pre-clerking there was a marked seasonal variation in the number of patients who failed to attend for surgery, which could be explained by absence on holiday. This seasonal variation disappeared after the start of pre-clerking clinics, but there has been no reduction in the number of cancellations for medical reasons. 相似文献
5.
Androgen receptor YAC transgenic mice carrying CAG 45 alleles show trinucleotide repeat instability 总被引:1,自引:15,他引:1
La Spada AR; Peterson KR; Meadows SA; McClain ME; Jeng G; Chmelar RS; Haugen HA; Chen K; Singer MJ; Moore D; Trask BJ; Fischbeck KH; Clegg CH; McKnight GS 《Human molecular genetics》1998,7(6):959-967
X-linked spinal and bulbar muscular atrophy (SBMA) is caused by a CAG
repeat expansion in the first exon of the androgen receptor (AR) gene.
Disease-associated alleles (37-66 CAGs) change in length when transmitted
from parents to offspring, with a significantly greater tendency to shift
size when inherited paternally. As transgenic mice carrying human AR cDNAs
with 45 and 66 CAG repeats do not display repeat instability, we attempted
to model trinucleotide repeat instability by generating transgenic mice
with yeast artificial chromosomes (YACs) carrying AR CAG repeat expansions
in their genomic context. Studies of independent lines of AR YAC transgenic
mice with CAG 45 alleles reveal intergenerational instability at an overall
rate of approximately 10%. We also find that the 45 CAG repeat tracts are
significantly more unstable with maternal transmission and as the
transmitting mother ages. Of all the CAG/CTG repeat transgenic mice
produced to date the AR YAC CAG 45 mice are unstable with the smallest
trinucleotide repeat mutations, suggesting that the length threshold for
repeat instability in the mouse may be lowered by including the appropriate
flanking human DNA sequences. By sequence-tagged site content analysis and
long range mapping we determined that one unstable transgenic line has
integrated an approximately 70 kb segment of the AR locus due to
fragmentation of the AR YAC. Identification of the cis - acting elements
that permit CAG tract instability and the trans -acting factors that
modulate repeat instability in the AR YAC CAG 45 mice may provide insights
into the molecular basis of trinucleotide repeat instability in humans.
相似文献
6.
P?Mallick J?Chakrabarti Mallick B?Guha AR?Khuda-BukhshEmail author 《BMC complementary and alternative medicine》2003,3(1):7
Background
Arsenic in groundwater and its accumulation in plants and animals have assumed a menacing proportion in a large part of West Bengal, India and adjoining areas of Bangladesh. Because of the tremendous magnitude of the problem, there seems to be no way to tackle the problem overnight. Efforts to provide arsenic free water to the millions of people living in these dreaded zones are being made, but are awfully inadequate. In our quest for finding out an easy, safe and affordable means to combat this problem, a homeopathic drug, Arsenicum Album-30, appears to yield promising results in mice. The relative efficacies of two micro doses of this drug, namely, Arsenicum Album-30 and Arsenicum Album-200, in combating arsenic toxicity have been determined in the present study on the basis of some accepted biochemical protocols. 相似文献7.
Background
The current status of radioiodine-131 (RaI) dosimetry for Graves' hyperthyroidism is not clear. Recurrent hyperthyroidism and iatrogenic hypothyroidism are two problems which interact such that trying to solve one leads to exacerbation of the other. Optimized RaI therapy has therefore begun to be defined just in terms of early hypothyroidism (ablative therapy) as physicians have given up on reducing hypothyroidism.Methods
Optimized therapy is evaluated both in terms of the greatest separation of cure rate from hypothyroidism rate (non-ablative therapy) or in terms of early hypothyroidism (ablative therapy) by mathematical modeling of outcome after radioiodine and critically discussing the three common methods of RaI dosing for Graves' disease.Results
Cure follows a logarithmic relationship to activity administered or absorbed dose, while hypothyroidism follows a linear relationship. The effect of including or omitting factors in the calculation of the administered I–131 activity such as the measured thyroid uptake and effective half-life of RaI or giving extra compensation for gland size is discussed.Conclusions
Very little benefit can be gained by employing complicated methods of RaI dose selection for non-ablative therapy since the standard activity model shows the best potential for cure and prolonged euthyroidism. For ablative therapy, a standard MBq/g dosing provides the best outcome in terms of cure and early hypothyroidism. 相似文献8.
Malate dehydrogenase (MDH) (E.C.1.1.1.37) activity was detected in the filariaMolinema dessetae at a level similar to those found in other filariae. InM. dessetae, the cytoplasmic form (c-MDH) predominated and the study was performed on partially purified fractions. The pH optimum for oxaloacetate reduction was 6.1, with maximal activity at 7811 nmol min–1 mg protein–1, but high concentrations of oxaloacetate inhibited MDH activity. TheK
m value for oxaloacetate was determined as 22 M forM. dessetae c-MDH and 33M for mammalian c-MDH. Anthelmintic drugs were compared as potential inhibitors of filarial and mammalian c-MDH. Among the compounds evaluated, amocarzine showed a specific inhibitory effect on filarial c-MDH through only at high concentrations. Suramin alone showed an inhibitory effect at low concentrations (K
i=1.15 M) but without selective action towards filarial c-MDH. The suramin type of inhibition was found to be competitive. Suramin probably acts on both enzymes in the same manner. Nevertheless,M. dessetae c-MDH is proposed as a suitable enzyme assay model to screen MDH inhibitors as potential filaricides. 相似文献
9.
Harald Treuer Martin Kocher Moritz Hoevels Stefan Hunsche Klaus Luyken Mohammad Maarouf Jürgen Voges Rolf-Peter Müller Volker Sturm 《Radiotherapy and oncology》2006,81(1):25-32
OBJECTIVE: Determination of the impact of inaccuracies in the determination and setup of the target point in stereotactic radiosurgery (SRS) on the expectable complication and control probabilities. METHODS: Two randomized samples of patients with arteriovenous malformation (AVM) (n=20) and with brain metastases (n=20) treated with SRS were formed, and the probability for complete obliteration (COP) or complete remission (CRP), the size of the 10 Gy-volume in the brain tissue (VOI10), and the probability for radiation necrosis (NTCP) were calculated. The dose-effect relations for COP and CRP were fitted to clinical data. Target point deviations were simulated through random vectors and the resulting probabilities and volumes were calculated and compared with the values of the treatment plan. RESULTS: The decrease of the relative value of the control probabilities at 1mm target point deviation was up to 4% for AVMs and up to 10% for metastases. At 2 mm the median decrease was 5% for AVMs and 9% for metastases. The value for the target point deviation, at which COP and CRP decreased about 0.05 in 90% of the cases, was 1.3 mm. The increase of NTCP was maximally 0.0025 per mm target point deviation for AVMs and 0.0035/mm for metastases. The maximal increase of VOI10 was 0.7 cm(3)/mm target point deviation in both patient groups. CONCLUSIONS: The upper limit for tolerable target point deviations is at 1.3mm. If this value cannot be achieved during the system test, a supplementary safety margin should be applied for the definition of the target volume. A better accuracy level is desirable, in order to ensure optimal chances for the success of the treatment. The target point precision is less important for the minimization of the probability of radiation necroses. 相似文献