全文获取类型
收费全文 | 464篇 |
免费 | 38篇 |
国内免费 | 32篇 |
专业分类
儿科学 | 9篇 |
妇产科学 | 5篇 |
基础医学 | 44篇 |
口腔科学 | 18篇 |
临床医学 | 33篇 |
内科学 | 100篇 |
皮肤病学 | 16篇 |
神经病学 | 13篇 |
特种医学 | 114篇 |
外科学 | 26篇 |
综合类 | 86篇 |
预防医学 | 6篇 |
眼科学 | 4篇 |
药学 | 43篇 |
肿瘤学 | 17篇 |
出版年
2022年 | 2篇 |
2021年 | 5篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 4篇 |
2016年 | 6篇 |
2015年 | 5篇 |
2014年 | 6篇 |
2013年 | 11篇 |
2012年 | 11篇 |
2011年 | 12篇 |
2010年 | 11篇 |
2009年 | 17篇 |
2008年 | 20篇 |
2007年 | 34篇 |
2006年 | 25篇 |
2005年 | 22篇 |
2004年 | 7篇 |
2003年 | 10篇 |
2002年 | 7篇 |
2001年 | 10篇 |
2000年 | 11篇 |
1999年 | 14篇 |
1998年 | 36篇 |
1997年 | 25篇 |
1996年 | 23篇 |
1995年 | 20篇 |
1994年 | 19篇 |
1993年 | 15篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 6篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 5篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 1篇 |
1978年 | 5篇 |
1977年 | 3篇 |
1976年 | 1篇 |
1975年 | 7篇 |
1971年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有534条查询结果,搜索用时 0 毫秒
91.
HPLC分离测定格列齐特片及其有关物质 总被引:6,自引:0,他引:6
目的:建立新的HPLC法分离测定格列齐特征及其有关物质。方法:色谱条件为:Shim-Pack VP-ODS(5um,150mm*4.6mm i.d.)色谱柱;甲醇-0.02mol/L磷酸(用三乙胺调节PH至3.5),(70:30)为流动相;检测波长为229nm。结果:在50-300ug;/ml的浓度范围内线性关系良好。r=0.9999(n=6);平均回收率为100.5%,RSD为0.17%(n=6),重复进样RSD为0.12%(n=6),格列齐特及其有关物质得到基线分离。结论:本法简便,快速,准确,适用于格列齐特及其制剂的质量控制。 相似文献
92.
93.
The authors studied 54 patients with multisystem trauma, including blunt chest injury, using combined dynamic first-pass and electrocardiographically (ECG) gated radionuclide ventriculography (RNV) to evaluate for posttraumatic myocardial dysfunction. Twenty-six of 54 (48%) patients had abnormalities of ventricular wall motion. The ventricular dysfunction was confined to the right ventricle in 92% of cases. In general, abnormalities consisted of right ventricular dilatation and diffuse hypokinesia, although in seven cases there were localized wall-motion abnormalities. The right ventricular ejection fraction of those patients with wall-motion abnormalities was significantly lower than those with normal studies. Left ventricular ejection fraction did not differ significantly between these groups. ECG changes were not associated with the cardiac dysfunction demonstrated scintigraphically, nor was there a relationship between the number or type of extrathoracic or thoracic injuries demonstrated by RNV. Follow-up studies obtained in 15 cases showed a significant overall improvement in cardiac function by 3 weeks after injury. Combined first-pass and ECG-gated RNV is useful for the identification and follow-up of patients with posttraumatic cardiac dysfunction. 相似文献
94.
95.
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
96.
97.
The irritable bowel syndrome is the commonest gastrointestinal disorder seen in practice but its exact prevalence in India is not known. This study was carried out to determine the prevalence of symptoms compatible with this diagnosis in general population. A cross sectional random sample survey was conducted in various strata of urban population in Wanoworie area of Pune. Survey utilized personal interviews based on a questionnaire. Symptoms were evaluated as per Manning criteria and the diagnosis of irritable bowel syndrome was defined by Kruis diagnostic index. Of the 1010 subjects interviewed, 370 (37%) reported more than 6 episodes of abdominal pain in previous 6 months, with 333 reporting symptoms consistent with the the diagnosis of irritable bowel syndrome. At least one of the Manning''s symptoms was present in 307 out of 370 subjects (83%). The male female ratio was 5.3:1. Among males, 288 (35%) and among females 82 (53.2%) persons had at least some degree of abdominal discomfort. Other common symptoms were: excessive passage of wind (42.2%), irregular bowel habits (33%), excessive belching (30.8%), constipation (27.5) and feeling of incomplete evacuation(28.1%). About one third of the symptomatic subjects (134 or 36.2%) had seen a doctor or wanted to be seen by a specialist. Overall prevalence of the symptoms consistent with irritable bowel syndrome thus, is 33 per cent though only about a third of these may possibly consult a doctor. Follow up of all these patients for a mean duration of 8.3 months showed that no case of organic disease was picked up either by the scoring system or by the gastroenterologist. Symptoms consistent with the diagnosis of irritable bowel syndrome are see in almost one third of the study population residing in Wanoworie area of Pune.KEYWORDS: Irritable bowel syndrome, Kruis diagnostic index, Manning''s symptoms 相似文献
98.
Matson GB; Twieg DB; Karczmar GS; Lawry TJ; Gober JR; Valenza M; Boska MD; Weiner MW 《Radiology》1988,169(2):541-547
Localized phosphorus-31 magnetic resonance (MR) spectroscopy in humans has previously been accomplished with surface coils by means of depth-resolved surface coil spectroscopy or rotating frame experiments, in which the extent of tissue sampled critically depends on surface coil placement. The authors' goal was to modify the surface coil image-selected in vivo spectroscopy (ISIS) experiment to accomplish three-dimensional volume selection through application of selective pulses in the presence of B0 gradients. Advantages of ISIS include the ability to use proton images to define the volume of interest (VOI) and reduced dependence on exact positioning of the surface coil. However, rapid replication of the surface coil ISIS experiment can cause spectral contamination from signals originating outside the VOI. A modified version of the ISIS experiment was developed to alleviate contamination under conditions of rapid replication. Applications of localized P-31 MR spectroscopy for observation of high-energy phosphorus metabolites are presented in human liver, heart, and transplanted and normal kidney. 相似文献
99.
100.
GS Heithersay 《Australian dental journal》2007,52(S1):S105-S121
A correct diagnosis and an understanding of the aetiology and dynamics of the processes involved in tooth resorption is critical to effective management. Tooth resorptions can be classified as: (1) trauma induced; (2) infection induced; or (3) hyperplastic invasive. Some transient trauma induced resorptions require no treatment but must be carefully monitored to check that there are no complicating issues such as infection. In cases of trauma induced replacement resorption, a multidisciplinary approach is usually necessary to ensure an optimal long-term solution. Infection induced tooth resorptions require the removal of the invading micro-organisms by endodontic therapy including intra-canal medication which can also facilitate repair of the resorbed tooth structure. The hyperplastic invasive tooth resorptions pose considerable challenges in management due to the complexity and aggressive nature of the resorptive process. With careful case selection and complete inactivation of resorptive tissue successful management can be achieved. 相似文献