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   552篇
  免费   48篇
耳鼻咽喉   5篇
儿科学   29篇
妇产科学   21篇
基础医学   102篇
口腔科学   3篇
临床医学   54篇
内科学   122篇
皮肤病学   37篇
神经病学   53篇
特种医学   5篇
外科学   46篇
综合类   6篇
预防医学   49篇
眼科学   11篇
药学   32篇
中国医学   2篇
肿瘤学   23篇
  2022年   9篇
  2021年   17篇
  2020年   12篇
  2019年   23篇
  2018年   21篇
  2017年   8篇
  2016年   7篇
  2015年   21篇
  2014年   22篇
  2013年   25篇
  2012年   27篇
  2011年   33篇
  2010年   13篇
  2009年   28篇
  2008年   20篇
  2007年   25篇
  2006年   28篇
  2005年   34篇
  2004年   24篇
  2003年   28篇
  2002年   27篇
  2001年   22篇
  2000年   24篇
  1999年   24篇
  1998年   5篇
  1997年   3篇
  1996年   4篇
  1994年   2篇
  1992年   3篇
  1991年   7篇
  1990年   2篇
  1988年   4篇
  1987年   6篇
  1986年   4篇
  1985年   3篇
  1983年   2篇
  1982年   4篇
  1981年   2篇
  1980年   2篇
  1978年   2篇
  1976年   1篇
  1974年   2篇
  1973年   1篇
  1971年   1篇
  1970年   3篇
  1969年   2篇
  1968年   3篇
  1966年   1篇
  1960年   1篇
  1954年   2篇
排序方式: 共有600条查询结果,搜索用时 125 毫秒
1.
2.
Three hundred and sixty one extracorporeal lithotripsies for renal, ureteric and bladder stones have been performed by means of a system of ultrasonographic detection and piezoelectric destruction (EDAP LT01). The localisation of the stone is achieved by a 5 MHz real time sectorial transducer situated in the centre of a small dish containing 320 piezoelectric elements concentrated in a source 5 mm wide by 15 mm high. The pressure recorded in vitro is 900 bars. The stone is easily detected in 87.2% of cases, difficult to detect in 10% of cases and impossible to detect in 28% of cases. By using a frequency of 1.25 to 5 per second, extracorporeal lithotripsy can be performed without any local, regional or general anaesthesia and without premedication in the 120 patients with a renal stone, reviewed between 1 and 3 months, 88 (73%) were considered to be complete successes. Ten (8%) were considered to be failures and 19 (21%) were considered to be partial successes. The best results were obtained in stones of the renal pelvis less than 20 mm in diameter. These results relate to a mean series which must take into account the successive improvements made to the lithotripter. Today, stone fragmentation is obtained in 93% of cases. Thirty six stones of the lumber and pelvic ureter were treated with success rates of 93% and 50%, respectively. Six bladder calculi were treated with a 50% success rate. Forty two patients were treated without being admitted to hospital.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
3.
Purpose. The objective of this study was to determine the relationship between muscular strength and bone mineral density (BMD) in patients undergoing regular haemodialysis. Methods. The BMD was measured in the lumbar spine (L2L4) and in the proximal femur (femoral neck and trochanter) with dual-energy X-ray absorptiometry (DEXA (Lunar DPX). Muscular strength of the extensors, flexors and abductors muscles of the femur (proximal muscles) and extensors muscles of the back was measured with an isometric cynamometer. Thirty patients, 15 women with a mean age of 33.7 years (18-43) and 15 men with a mean age of 15.5 years (18-65) were included in the study. Results. There was a positive and significant correlation between the BMD of the femoral neck and muscular strength of the flexors (r=0.490, P<0.005), the extensors (r=0.658, P<0.01) and the abductors muscles of the femur (r=0.671, P <0.0008), as well as between the muscular strength of the flexors (r=0.413, P <0.02) and extensors muscles of the femur (r=0.433, P <0.01) with BMD of the trochanter. There was no correlation between the muscular strength of the back extensor muscles and the BMD of the lumbar spine (r=-0.119, P NS). There was no correlation between the BMD and the number of years of haemodialysis therapy (r=-0.032, P NS), the patient's age (r=-159, P NS), or the value of serum PTH (r=0.369, P NS) respectively. However, there was a significant correlation between the BMD of the femoral neck with muscular strength (r=0.602, P <0.05). Conclusion. This study reveals the close relationship that exists between muscular strength of the proximal muscles and the BMD of proximal femur in patients undergoing haemodialysis.  相似文献   
4.
The development of molecular techniques for HLA typing has allowed the identification of genes previously assigned as serologic blank alleles. Lack or poor cell surface expression has been found for molecules coded by HLA-A, -B, -DRB4, -DRB5, and -DPB1 genes. In this report we describe the first HLA-C gene encoding for a null cell surface molecule. HLA-Cw*0409 N shows a point deletion at position 1095 within exon 7. This mutation provokes a codon reading shift, generating a new translation stop codon 97 bp downstream to that described in alleles normally expressed. This new stop codon location implies the presence of 32 extra amino acid residues in the cytoplasmic domain. Transfection experiments suggest that elongation of the cytoplasmic domain in Cw*0409 N would be the cause of cell surface expression failure, although Cw*0409 N heavy chain is able to create stable complexes with beta2-microglobulin. HLA-C fragment length analysis in a small selected group of samples with B44-Cblk haplotypic associations allowed us to identify two additional subjects showing both a serologic silent Cw*04 allele and a point base deletion at the 3' end of the HLA-C gene. This finding indicates that the allele frequency of Cw*0409 N within serologic C blank alleles would be appreciable, although basically restricted to the (A23)-Cw*0409 N-B*4403-DR7-DQ2 haplotype.  相似文献   
5.
Hopes raised by results published by Leibel and Sheline in "Journal of Neurosurgery" 66 (1987) 1-22 have not been confirmed in our own work. Nevertheless, even our own results, though not statistically significant, have shown a combination of surgery, irradiation, and polychemotherapy to be recommendable for treatment of cases of malignant supratentorial glioma.  相似文献   
6.
The COVID‐19 pandemic continues to be a major public health threat globally and low‐ and middle‐income countries (LMICs) are not an exception. The impact of the COVID‐19 pandemic is far‐reaching on many areas including but not limited to global health security, economic and healthcare delivery with a potential impact on access to healthcare in LMICs. We evaluate the impact of the COVID‐19 pandemic on access to healthcare in LMICs, as well as plausible strategies that can be put in place to ensure that the delivery of healthcare is not halted. In order to mitigate the devastating effect of the COVID‐19 pandemic on the already weak health systems in LMICs, it is much necessary to reinforce and scale up interventions and proactive measures that will ensure that access to healthcare is not disrupted even in course of the pandemic.  相似文献   
7.
We present a small child with febrile peaks and syncopal episodes secundary to ventricular tachycardia, in whom it was eventually possible to demostrate the Brugada Syndrome with a special presentation in the ECG; early repolarization pattern in lead I and a aVL and Brugada pattern during fever in V1‐V2. This is, to our knowledge, tha first case with this special ECG presentation in a small child.  相似文献   
8.
Dystrophic epidermolysis bullosa is a rare blistering condition caused by mutations in the COL7A1 gene. Different clinical variants have been described, with dominant and recessive inheritance, but no consistent findings have been elucidated to establish a genotype–phenotype correlation. We present three unrelated patients with two identical pathogenic compound heterozygous mutations in the COL7A1 gene that developed different clinical forms of dystrophic epidermolysis bullosa—epidermolysis bullosa pruriginosa and mild recessive non‐Hallopeau–Siemens—raising the possibility of other genetic or environmental modifying factors responsible for the phenotype of the disease.  相似文献   
9.
Epidermolytic palmoplantar keratoderma (EPPK), an autosomal‐dominant genodermatosis, is the most frequently occurring hereditary palmoplantar keratoderma. EPPK is characterized by hyperkeratosis of the palms and soles. Approximately 90% of patients present with mutations in the KRT9 gene, which encodes for keratin 9. Many of these mutations are located within the highly conserved coil 1A region of the alpha‐helical rod domain of keratin 9, an important domain for keratin heterodimerization. The objective was to assess the clinical and molecular characteristics of a Mexican family with EPPK. The clinical characteristics of members of this family were analyzed. The KRT9 gene of affected members was polymerase chain reaction amplified from genomic DNA and sequenced. All affected members of the family had hyperkeratosis of the palms and soles with knuckle pads. The R163W mutation in the KRT9 gene was present in all affected individuals who were tested. Although R163W is the most frequent KRT9 mutation in patients with EPPK, only two families have been reported with knuckle pads associated with this mutation. Our findings indicate that knuckle pads can be associated with EPPK and the R163W mutation in a family with a genetic background different from that described here.  相似文献   
10.
Group A beta‐hemolytic streptococcus cause most vulvovaginal infections seen in prepubertal girls. Bacterial vaginosis is a common cause of abnormal vaginal discharge in women of childbearing age but is rare in children. Data are insufficient to suggest that bacterial vaginosis is an exclusively sexually transmitted disease. We report a 10‐year‐old girl with no history or suspicion of sexual abuse who developed bacterial vaginosis in the context of a lichen sclerosus being treated with tacrolimus ointment. Secondary bacterial infection in lichen sclerosus is uncommon. We speculate that the immunosuppressive effect of topical tacrolimus could have triggered the infection.  相似文献   
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