首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   106篇
  免费   6篇
  国内免费   10篇
儿科学   5篇
妇产科学   5篇
基础医学   8篇
口腔科学   13篇
临床医学   14篇
内科学   14篇
皮肤病学   8篇
神经病学   2篇
特种医学   6篇
外科学   12篇
综合类   5篇
预防医学   4篇
眼科学   2篇
药学   16篇
中国医学   5篇
肿瘤学   3篇
  2022年   5篇
  2019年   2篇
  2018年   4篇
  2017年   5篇
  2016年   4篇
  2014年   3篇
  2013年   5篇
  2012年   9篇
  2011年   11篇
  2010年   5篇
  2009年   3篇
  2008年   2篇
  2007年   11篇
  2006年   6篇
  2005年   11篇
  2004年   2篇
  2003年   2篇
  2002年   6篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1997年   4篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1988年   2篇
  1986年   1篇
  1985年   2篇
  1944年   1篇
  1939年   1篇
排序方式: 共有122条查询结果,搜索用时 15 毫秒
31.
Cytosolic estradiol and progesterone receptor concentrations were measured in luteal phase endometrial biopsy samples obtained from 12 anovulatory or oligoovulatory women on clomiphene citrate therapy and from 40 normal control subjects. Clomiphene citrate treatment (250 to 750 mg per cycle) decreased both endometrial estradiol and progesterone receptor concentrations. Estradiol receptor levels were nondetectable in seven tissue samples and progesterone receptor levels in four samples from the 12 subjects given clomiphene citrate compared to nondetectable estradiol receptor concentrations in one tissue sample and progesterone receptor concentrations in two samples from the 40 normal control subjects. In histologically dated endometrium, mean estradiol receptor concentrations on days 20 to 23 and progesterone receptor levels on days to 24 to 27 were lower than the values observed in the comparable dated endometrium of normal ovulatory women. Steroid receptor concentrations correlated negatively with the duration of clomiphene citrate therapy, which implies a time-dependent suppressive effect of clomiphene citrate on measurable cytosolic estradiol and progesterone receptor concentrations during the luteal phase of the cycle.  相似文献   
32.
There is increasing evidence that cytogenetically invisible chromosome rearrangements are an important cause of genetic disease. Clues to the chromosomal location of these rearrangements may be provided by a specific clinical diagnosis, which can then be investigated by targeted FISH or molecular studies. However, the phenotypic features of some microdeletion syndromes are difficult to recognise, particularly in infants. In addition, the presence of other chromosome aneuploidy may mask the typical clinical features. In the present study, the presence of tubers on cranial magnetic resonance imaging (MRI) of a 5-week-old infant prompted an investigation, by FISH, with probes from the tuberous sclerosis gene, TSC2. This and further FISH deletion mapping studies revealed a submicroscopic deletion encompassing the entire TSC2 gene and the adjacent PKD1 gene on one chromosome 16, confirming a del(16)(p13.3). Because of the large number of abnormal phenotypic features in this infant, we performed a 12-colour FISH assay (M-TEL) to screen for subtelomeric rearrangements involving the del(16p). The M-TEL assay revealed a cryptic der(16)t(16;19)(p13.3;p13.3). Further FISH with 19p and 19q subtelomeric probes demonstrated that this was derived from a balanced maternal t(16;19)(p13.3;p13.3). Importantly, 24-colour painting by multiplex FISH (M-FISH) failed to detect the translocation in either the infant or his mother. Based on our FISH mapping studies, we estimate the size of the trisomic region from 19p13.3 to be approximately 2 Mb, and the region of monosomy for 16p13.3 as 2.25 Mb. This case adds to the growing literature which indicates that many apparent chromosomal deletions are unbalanced translocations. The M-TEL assay provides a sensitive alternative to M-FISH for the detection of these subtle telomeric rearrangements.  相似文献   
33.
娄超  边惠洁  陈志南 《医学争鸣》2001,22(4):369-371
0 引言 凋亡或细胞程序性死亡是一种不同于细胞坏死的死亡方式 ,是在基因控制下的有序死亡 ,是一个主动性自杀过程 ,常伴有特征性形态学和生化变化 .临床上放射线治疗肿瘤主要应用射线诱导细胞凋亡这一机制 .1 88Re发射 2 110Ke V的 β射线 ,15 5 Ke Vγ射线 ,半衰期 17h,具有良好的核物理性质 .国外 1 88Re的研究主要在 1 88Re标记单克隆抗体对肿瘤的放射免疫治疗 ,并显示具有一定的疗效 ,而国内关于 1 88Re的研究较少 ,经文献检索未见有关于 1 88Re诱导细胞凋亡的报道 .本实验旨在研究 1 88Re-β射线诱导人肝癌细胞系 h HCC(human…  相似文献   
34.
The authors investigate the effect of bumetan ide, an inhibitor of NKCC1 and a loop diuretic, on the tone of human umbilical artery (HUA). Rings of HUA (n = 35) from vaginal deliveries were suspended for isometric tension recordings in organ baths. Cumulative concentration-response curves to serotonin, histamine, and KCl were performed in the absence (control) or in the presence of bumetanide. The relaxant effect of bumetanide was also evaluated in serotonin- and histamine-induced contractions. Bumetanide inhibited HUA tone in serotonin- and histamine-induced contractions with significant changes in the potency (pD(2)) and maximum contractile response (E(max)) values. However, only pD( 2) values for KCl-induced contraction significantly changed in the presence of bumetanide. Bumetanide caused concentration-dependent and sustained relaxations in serotonin-induced contraction; however, there was refractoriness in histamine-induced contraction. These findings raise the possibility that NKCC1 may play a role in the regulation of the umbilical artery tone.  相似文献   
35.
海风藤中巴豆环氧素的衍生物研究   总被引:1,自引:0,他引:1  
陈泽乃  徐佩娟 《药学学报》1993,28(11):876-880
Through reactions of deacetylation and partial deacetylation with selected opening of epoxide ring, seven derivatives of crotepoxide (futoxide), a known antitumor constituent from Piper futokudzura, were prepared. Preliminary pharmacological tests showed that individual derivative possess significant inhibitory activity at 2×10-4 mol/L to the PAF—induced platelet aggregation, while crotepoxide has no effect even at fivefold of this concentration.  相似文献   
36.
Color Doppler sonography was performed in 32 patients with a painful scrotum in whom testicular ischemia from torsion or postherniorrhaphy was clinically suspected. Surgical correlation was available in 15 patients, and scintigraphic correlation was available in 17 patients. Seven of the 32 patients were diagnosed as having testicular ischemia from torsion. Color Doppler flow imaging demonstrated a lack of intratesticular flow in six of the seven testes with torsion and relatively normal intratesticular flow in one of the patients with acute torsion. Normal or increased intratesticular flow was demonstrated by color Doppler in all 57 of the nonischemic testes. Using the single criterion of presence or absence of identifiable intratesticular flow, the authors found that color Doppler was 86% sensitive, 100% specific, and 97% accurate in the diagnosis of torsion and ischemia in the painful scrotum. Color Doppler sonography is an accurate, noninvasive means of rapidly assessing perfusion of the testis in the painful scrotum.  相似文献   
37.
38.
Congenital long QT syndrome (LQTS) is an inherited potentially fatal arrhythmogenic disorder that is characterized by prolonged corrected QT (QTc) interval. Mutations in three genes (KCNQ1, KCNH2, and SCN5A) account for the majority of the cases. However, 10 other genes are now known to be implicated in LQTS. In this work, we describe the clinical and molecular analysis in a large Saudi family with LQTS. Screening KCNQ1, KCNH2, and SCN5A genes in the proband, who presented with syncope, led to the identification of a heterozygous mutation (p.H258P) in KCNQ1. An extended clinical and genetic screening of the family identified 11 other members who were carriers for this mutation. All identified carriers had prolonged QTc intervals; yet, only two were symptomatic. Screening the family members for three LQTS modifiers (rs4657139 and rs16847548 in NOS1AP and KCNE1‐D85N) did not reveal a correlation with symptoms or QTc intervals. The electrocardiographic and molecular analysis stratified seven carriers at high risk of a cardiac event as they had a QTc of ≥500 ms and were carriers of a KCNQ1 mutation. Our work illustrates the importance of extended family screening in LQTS to identify silent carriers and hence adopt the most appropriate therapeutic and preventive intervention.  相似文献   
39.
The aim of this study was to compare quantitatively the masticatory performance of patients with overdentures supported by two implants, conventional complete dentures, and natural dentitions. Each patient was asked to chew a gelatin cube. The collected remains of the test food (gelatine cube) were fractioned by a sieving procedure and weighed. Maximum mouth opening and masticatory area were measured using kinesiography. There were statistically significant differences among groups with respect to masticatory performance using a 3.15-mm-diameter sieve (P < .001) and 0.5-mm-diameter sieve (P < .001), masticatory area (P = .019), and maximum mouth opening (P < .001). Increasing retention of a mandibular complete denture with two implants improved masticatory performance.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号