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   156篇
  免费   15篇
耳鼻咽喉   7篇
儿科学   17篇
妇产科学   9篇
基础医学   50篇
临床医学   5篇
内科学   28篇
皮肤病学   2篇
神经病学   28篇
特种医学   3篇
外科学   6篇
预防医学   6篇
眼科学   1篇
药学   2篇
肿瘤学   7篇
  2019年   1篇
  2014年   2篇
  2013年   1篇
  2011年   2篇
  2010年   2篇
  2009年   5篇
  2008年   10篇
  2007年   7篇
  2006年   9篇
  2005年   5篇
  2004年   8篇
  2003年   6篇
  2002年   5篇
  2001年   14篇
  2000年   9篇
  1999年   1篇
  1997年   1篇
  1996年   2篇
  1995年   3篇
  1994年   3篇
  1993年   2篇
  1992年   3篇
  1991年   6篇
  1990年   5篇
  1989年   3篇
  1988年   4篇
  1987年   4篇
  1986年   2篇
  1985年   7篇
  1984年   5篇
  1983年   7篇
  1982年   2篇
  1981年   3篇
  1980年   4篇
  1979年   8篇
  1978年   2篇
  1977年   4篇
  1976年   1篇
  1973年   1篇
  1967年   1篇
  1936年   1篇
排序方式: 共有171条查询结果,搜索用时 15 毫秒
1.
The T-cell response induced by Francisella tularensis antigen in sensitized subjects was characterized in vitro by measuring DNA synthesis in whole-blood and mononuclear cell cultures, interleukin 2 (IL-2) and gamma interferon (IFN-gamma) production, and IL-2 receptor expression. Correlations between these variables were estimated. The strengths of the responses were compared in 21 subjects naturally infected 2 years ago, 6 subjects vaccinated 5 to 6 years ago, and 13 control subjects with no history of infection or vaccination. Subjects with a history of natural infection synthesized more DNA in both whole-blood and mononuclear cell cultures, secreted more IL-2 and IFN-gamma, and expressed more IL-2 receptors than control subjects did. All these responses differed highly significantly (P less than 0.001) from those of the control subjects. The vaccinees exhibited somewhat lower responses than the naturally immunized subjects did, but the vaccinees could be distinguished from the control subjects by their DNA synthesis, receptor expression, and IFN-gamma production (P less than 0.01 to 0.001). The vaccinees showed a lower response, in terms of DNA synthesis and IL-2 secretion (P less than 0.05), than the infected group did but responded in a manner similar to that of this group, with respect to receptor positivity and IFN-gamma secretion (P greater than 0.10). The correlations between all the T-cell functions were good, with highly significant correlations (P less than 0.001) between whole-blood DNA synthesis and IL-2 and IFN-gamma secretion and between the two lymphokines (P less than 0.001). The results not only increase our knowledge of the T-cell response to tularemia antigen but also give an alternative approach to DNA synthesis measurement for the quantitation of T-cell responses. The results for the low-responding sensitized subjects seem to indicate that the parameters were comparable in sensitivity.  相似文献   
2.
3.
We describe a lethal malformation syndrome in 28 newborn infants from 18 families. The main manifestations were hydrocephalus (often with an unusual structure of the brain and the occipital bone), very small mandible, Polydactyly, congenital heart defect, abnormalities of the respiratory organs, and (different from the Meckel syndrome) normal kidneys. Polyhydramnios and stillbirth or neonatal death were the rule. Autosomal recessive inheritance is evident. This syndrome is another in the group of rare recessive disorders which are found in Finland. Because of the 25 % recurrence risk and possibilities for prenatal diagnosis, this syndrome should be recognized by paediatricians and, because of the frequent stillbirths, also by obstetricians and pathologists. The name hydrolethalus syndrome (hydramnios, hydrocephalus, lethality) may be of help in this.  相似文献   
4.
Tenascin-C is an extracellular matrix glycoprotein that is spatially expressed during organogenesis, in inflammatory and fibrotic disorders, and in neoplasms. The aim of this study was to analyze its expression in developing human lung tissues during pseudoglandular, canalicular, saccular, and alveolar periods corresponding to Weeks 12 to 40. Lung tissues were obtained at autopsy from 34 nonmalformed cases. An immunohistochemical analysis and a messenger RNA (mRNA) in situ hybridization method combined with light microscopy were used. The extent of tenascin-C immunoreactivity was scored as absent, low, moderate, or strong in and around different types of pulmonary cells. The immunohistochemical expression for tenascin-C was strong beneath the airway epithelium, especially at the sites of airway subdivision during Weeks 12 to 23, whereas its expression was moderate or weak underneath alveolar and bronchiolar epithelia between Weeks 24 and 40. The expression for tenascin-C was strong in the intima of veins, especially in the canalicular period, i.e., Weeks 17 to 28. A moderate or strong immunoreactivity for tenascin-C was also observed around chondrocytes in every case studied during all periods. The increased expression of tenascin-C mRNA was most often seen in the cells below the airway epithelium. Taken together, tenascin-C is expressed in human lung during all developmental periods, and its expression is especially strong below the airway epithelium at the sites of airway subdivision.  相似文献   
5.
Epidemiological features of blood culture confirmed typhoid fever and antibiotic sensitivity of isolated Salmonella typhi strains were investigated in Bohol Province in Central Philippines from where no earlier information of these was avialable. Typhoid fever is endemic elsewhere in the Philippines (eg Metropolitan Manila and surroundings) where also multidrug resistant S. typhi strains have been detected. A laboratory for surveillance of invasive bacterial infections was established in a tertiary care government hospital, in Bohol, Central Philippines, in 1994. Patients with suspected typhoid fever or other serious infection were managed and blood cultures from them were taken according to clinicians' judgment. Blood cultures were processed and the isolated bacteria identified using generally accepted methods. S. typhi and other Salmonella isolates were identified using commercial antisera. Patient data were collected from hospital records. Of a total of 4,699 blood cultures done during a period of 3 3/4 years, 1,530 (32%) were requested for suspected typhoid fever. S. typhi was the most common pathogen isolated from 422 patients (8.9%), followed by S. paratyphi A from 55 patients (1%). Most patients were young adults (43%) and school age children (28%). Male:female ratio was 1.5:1. Among the 422 patients, there were 9 (2%) deaths due to typhoid fever, all with complications. All S. typhi isolates were sensitive to chloramphenicol, cotrimoxazole, and ampicillin. Our observation on blood culture confirmed typhoid fever demonstrates its importance as a major infectious disease in Bohol and gives a sound basis for treatment of typhoid patients and for further clinical and epidemiologic studies of typhoid fever and for following antibiotic sensitivity of S. typhi in Bohol and elsewhere in the Philippines.  相似文献   
6.
Dr. S. M. Virtanen  T. Saukkonen  E. Savilahti  K. Ylönen  L. Räsänen  A. Aro  M. Knip  J. Tuomilehto  H. K. Åkerblom  R. Lounamaa  L. Toivanen  E. A. Kaprio  J. Pitkäniemi  E. Virtala  A. Fagerlund  M. v. Flittner  B. Gustafsson  C. Häggqvist  A. Hakulinen  L. Herva  P. Hiltunen  T. Huhtamäki  N. -P. Huttunen  T. Huupponen  M. Hyttinen  T. Joki  R. Jokisalo  M. -L. Käär  S. Kallio  U. Kaski  L. Laine  J. Lappalainen  J. Mäenpää  A. -L. Mäkelä  K. Niemi  A. Niiranen  P. Ojajärvi  T. Otonkoski  K. Pihlajamäki  S. Pöntynen  J. Rajantie  J. Sankala  J. Schumacher  M. Sillanpää  M. -R. Ståhlberg  C. -H. Stråhlmann  T. Uotila  M. Väre  P. Varimo 《Diabetologia》1994,37(4):381-387
Summary Associations of infant feeding patterns and milk consumption with cow's milk protein antibody titres were studied in 697 newly-diagnosed diabetic children, 415 sibling-control children and 86 birth-date-and sex-matched population-based control children in the nationwide Childhood Diabetes in Finland study. IgA and IgG antibody titres to the proteins of cow's milk formula, BLG and BSA, and IgM antibody titres to cow's milk formula proteins were measured by ELISA. Several inverse correlations were observed between the duration of breast-feeding or age at introduction of dairy products and antibody titres, and positive correlations were observed between milk consumption and antibody titres in all three populations studied. Multivariate analyses which included the infant feeding variables, milk consumption and current age simultaneously showed that the earlier the introduction of dairy products and the greater the consumption of milk was, the higher several antibody titres were. High IgA antibody titres to cow's milk formula were associated with a greater risk of IDDM both among diabeticpopulation-control and diabetic-sibling-control pairs when adjusted for other cow's milk antibody titres, dietary variables and in diabetic-sibling-control pairs also for ICA. The results suggest that young age at introduction of dairy products and high milk consumption during childhood increase the levels of cow's milk antibodies and that high IgA antibodies to cow's milk formula are independently associated with increased risk of IDDM.Abbreviations IDDM Insulin-dependent diabetes mellitus - BLG betalactoglobulin - BSA bovine serum albumin - ICA islet cell antibodies - IAA insulin autoantibodies - OR odds ratio - CI confidence interval  相似文献   
7.
Serum type (IgG, IgM and IgA-class) and secretory type antibodies specific to Streptococcus pneumoniae (Pn), Haemophilus influenzae (Hi) and Branhamella catarrhalis (Br) were measured by enzyme-linked immunosorbent assay (ELISA) in 46 serum and 114 middle ear effusion (MEE) samples from 85 children with acute otitis media (AOM). The samples were obtained within 12 h from the onset of the ear symptoms. Serum (but not secretory) type antibodies to the infecting Pn serotype were found in 24% of the MEE samples of the patients with Pn AOM and, correspondingly, serum and/or secretory type antibodies to Hi and Br were seen in 54% and 63% of the MEE samples of the patients with Hi or Br AOM, respectively. Moreover, antibodies against bacteria other than the causative one could also be found in the MEE. The occurrence of the serum type antibodies against these bacteria in the MEE was closely correlated with their serum levels. The findings of this study indicate that during the very early phase of AOM, the MEE contains both serum type antibodies originating from the serum, and secretory antibodies of middle ear origin. Among them there are antibodies specific to the three most common bacteria causing AOM (Pn, Hi, and Br) regardless of the bacterial etiology of the AOM attack in question.  相似文献   
8.
The hydrolethalus syndrome is an autosomal recessive malformation syndrome which has been recently described in Finland. The name hydrolethalus refers to the main findings, namely polyhydramnios, hydrocephalus and lethality. The patients are either stillborn or die soon after birth. The typical roentgenologic findings are hypoplasia of the tibia associated with the anomalies of the respective bone ray, e.g. metatarsus primus varus atavisticus, hallux varus or hallux duplex varus and hydrocephalus with extreme micrognathia and a specific midline defect of the occipital bone.  相似文献   
9.
10.
In a routine cytogenetic investigation of the outpatients of a hospital for the mentally retarded, a 26-year-old women with a presumptive interstitial deletion of the short arm of one of the X chromosomes was found. The same aberration was found in her phenotypically normal mother and in one of her four sisters, all phenotypically normal. By GTG- and QFQ-banding methods, the deletion was interpreted to involve the entire band Xp21 and adjacent parts of p11 and p22. The karyotype is written 46,X,del(X)(pter leads to p22::p11 leads to qter). By autoradiography and Bud R acridine orange technique, the deleted X was the late replicating one in all three affected persons. The deletion apparently causes shortness of stature but no other phenotypic symptoms or signs. Hence a gene or genes controlling stature is located in band Xp21 or regions immediately adjacent to this band. Since the absence of this region does not cause streak gonads, it does not contain genes controlling the formation of the ovaries. This appears to be the first example of a heritable chromosome deletion compatible with a normal phenotype and reproduction.  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