全文获取类型
收费全文 | 343篇 |
免费 | 16篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 7篇 |
儿科学 | 11篇 |
妇产科学 | 6篇 |
基础医学 | 20篇 |
口腔科学 | 20篇 |
临床医学 | 38篇 |
内科学 | 74篇 |
皮肤病学 | 8篇 |
神经病学 | 10篇 |
特种医学 | 48篇 |
外科学 | 17篇 |
综合类 | 12篇 |
预防医学 | 26篇 |
眼科学 | 3篇 |
药学 | 51篇 |
肿瘤学 | 26篇 |
出版年
2023年 | 3篇 |
2022年 | 5篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 6篇 |
2017年 | 4篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 4篇 |
2013年 | 13篇 |
2012年 | 8篇 |
2011年 | 8篇 |
2010年 | 17篇 |
2009年 | 15篇 |
2008年 | 10篇 |
2007年 | 19篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 9篇 |
2002年 | 4篇 |
2001年 | 9篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 14篇 |
1997年 | 13篇 |
1996年 | 16篇 |
1995年 | 10篇 |
1994年 | 13篇 |
1993年 | 12篇 |
1992年 | 3篇 |
1991年 | 7篇 |
1990年 | 4篇 |
1989年 | 9篇 |
1988年 | 12篇 |
1987年 | 7篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1972年 | 6篇 |
排序方式: 共有377条查询结果,搜索用时 31 毫秒
1.
Of 431 patients with gastric cancer observed in our institution, 23 (5.3%) had early gastric cancer (EGC). Macroscopic presentation, histology, depth of invasion, and lymph node involvement were evaluated in all the cases. All patients underwent surgery and an intensive follow-up was performed. Five of the 23 patients progressed, and the risk factors were examined. Histology seemed to be the main prognostic factor in our study, since intestinal type of EGC was associated to a significantly better prognosis. Total gastrectomy is indicated in the proximal localization of EGC, and should perhaps be performed also in cases presenting undifferentiated histology. 相似文献
2.
G C Porretta M Scalzo F Chimenti A Bolasco M Biava M Fischetti F Riccardi 《Il Farmaco; edizione scientifica》1987,42(9):629-639
The synthesis and microbiological activities of 2-methyl-5-aryl-3-furoic acids and 2-methyl-3-imidazolyl-methyl-5-aryl-3-furans are reported. Antimicrobial data in comparison with pyrrolnitrin showed an interesting antifungal activity but a very poor antibacterial activity. The presence of an imidazole nucleus does not increase antifungal activity. The introduction of a substituent in the para position of the aryl at a C5 of the furan ring affects antifungal activity. 相似文献
3.
Yang GC; Croaker D; Zhang AL; Manglick P; Cartmill T; Cass D 《Human molecular genetics》1998,7(6):1047-1052
Lethal white foal syndrome (LWFS) is a congenital anomaly of horses
characterized by a white coat colour and aganglionosis of the bowel, which
is similar to Hirschsprung disease (HSCR). We decided to investigate
possible mutations of the endothelin-B receptor gene ( EDNRB ) in LWFS as
recent studies in mutant rodents and some patients have demonstrated EDNRB
defects. First, we identified a full-length cDNA for horse EDNRB . This
cDNA fragment contained a 1329 bp open reading frame which encoded 443
amino acid residues. The predicted amino acid sequence was 89, 91 and 85%
identical to human, bovine and mouse as well as rat EDNRB respectively, but
only 55% identical to the human, bovine and rat endothelin A receptor
(EDNRA). Secondly, sequence analysis, together with allele-specific PCR and
the amplification- created restriction site (ACRS) technique, revealed a
dinucleotide TC-- >AG mutation, which changed isoleucine to lysine in
the predicted first transmembrane domain of the EDNRB protein. This was
associated with LWFS when homozygous and with the overo phenotype when
heterozygous.
相似文献
4.
Relationship between HLA-DRB1 and DQ alleles and the genetic susceptibility to type 1 diabetes 总被引:6,自引:0,他引:6
Objective To study the relationship between human leukocyte antigen (HLA)-DRB1 and DQ alleles and the genetic susceptibility of type 1 diabetes in North Chinese children. Methods Polymerase chain reaction (PCR) techniques were used to amplify the second exon of DRB1 and DQ alleles, after which sequence specific olignucleotide probe (SSOP) dot blot hybridization techniques were used to analyze the amplified products. Results DRB1*0301, DQA1*0301, DQB1*0201 alleles and DRB1*0301-DQA1*0501-DQB1*0201 haplotype were significantly increased in patients, while DQA1*0103 and DQB1*0601 alleles were significantly increased in controls. The distribution of DR4 and DR9 haplotypes in patients and controls were not significantly different, but DR3/DR4 and DR4/DR9 heterozygotes were significantly increased in patients. Conclusions DRB1*0301, DQA1*0301 and DQB1*0201 confer susceptibility while DQA1*0103 and DQB1*0601 confer protection to type 1 diabetes. DRB1*0301-DQA1*0501-DQB1*0201 haplotype offers a predisposition to type 1 diabetes in North Chinese. Although the distribution of DR4 and DR9 in patients and controls had no significant difference, DR3/DR4 and DR3/DR9 heterozygotes were significantly increased in patients, showing that the susceptive effects of DR3 and DR4 or DR4 and DR9 haplotypes could be added up. 相似文献
5.
Miranda Michele Zarivi Osvaldo Amicarelli Fernanda Ragnelli Anna Maria Aimola Pierpaolo Porretta Rocchina Natali Pier Giorgio Arcadi Antonio Savino Maria Poma Anna Bonfigli Antonella 《Journal of neuro-oncology》1997,31(1-2):185-193
This paper presents evidence that L-tyrosine oxidation products and 5,6-dihydroxyindole, an intermediate of melanin synthesis bind to and modify DNA structure, as tested by extracting cell DNA, using topoisomerase I and denaturation assays. When supercoiled plasmid pCU18 or pBR322 DNAs are treated with 5,6-dihydroxyindole the supercoiled species disappear and are converted to species less mobile in a gel retardation test with respect to relaxed DNA. 5,6-Dihydroxyindole causes an easier acid denaturation of the double helix. The results, that are dose dependent,would point to both intercalation and cross-linking of DNA by 5,6-dihydroxyindole and its oxidation product(s). 3H-L-tyrosine deriving radioactivity, bound to nuclear DNA, is higher at low pH, (5.6) if compared to pH 6.8. The highest radioactivity bound to cell DNA is found during the transition from the amelanotic to the melanotic phenotype in human melanoma cell lines. As a control, the binding of 3H-L-tyrosine radioactivity to human prostate fibroblast DNA was investigated. 相似文献
6.
We report our clinical experience with phototherapy in 3802 infants; 3629 were exposed to "standard" daylight phototherapy and 173 to "high-intensity" blue-light phototherapy. High-intensity blue-light phototherapy was twice as effective as standard daylight phototherapy in decreasing bilirubin concentrations. No failures occurred with high-intensity phototherapy compared with an overall failure rate of 1.84/1000 with daylight lamps; these cases were transferred to high-intensity phototherapy with prompt response. Rebound after cessation of phototherapy was greater in those exposed to high-intensity blue light with a significantly greater number requiring a second exposure. However, the incidence was still low. No third exposure was required in any infant. Nursing of infants under high-intensity blue light was more difficult and inconvenient as was clinical monitoring. The light also caused more stress on the nursing and medical personnel. However, the infants tolerated both types of phototherapy equally well. High-intensity blue-light phototherapy would seem to be the treatment of choice for infants with rapidly increasing or very high bilirubin levels, as well as in those not responding adequately to daylight phototherapy. 相似文献
7.
Early perioperative results and surgical recurrence after strictureplasty and miniresection for complicated Crohn's disease 总被引:2,自引:0,他引:2
Sampietro GM Cristaldi M Porretta T Montecamozzo G Danelli P Taschieri AM 《Digestive surgery》2000,17(3):261-267
BACKGROUND/AIMS: Strictureplasty (SP) or miniresective 'bowel-sparing' techniques (MR) can prevent the risk of intestinal stomia and short bowel syndrome in patients affected by Crohn's disease (CD). The aim of this study was to analyze the perioperative morbidity and mortality in 104 of 138 consecutive patients treated for CD complications using bowel-sparing techniques. We also considered the factors that may be related to the risk of perioperative complications and the long-term outcome. METHODS: One hundred and four patients were treated with SP and/or MR and then included in a prospectively maintained database. The factors claimed to influence perioperative complications were analyzed using Fisher's exact test for categorical observations and the Mann-Whitney U test for continuous variables. A multivariate analysis, using logistic regression, and a long-term time-to-event analysis using the Kaplan-Meier function, were also performed. RESULTS: Perioperative mortality was nil. In relation to the 6 postoperative complications (5.8%), 4 patients underwent minimal bowel resection (MR), 1 a MR with SP, and 1 SP alone. Three of these patients (2.9%) needed reoperation for septic complications, and 3 (2.9%) were treated as outpatients for enterocutaneous fistulas. A correlation (p < 0.05) was found between low serum hemoglobin levels and postoperative complications at univariate and multivariate analyses. The 5-year surgical recurrence-free rate was 75% overall, 73% for patients treated with SP, 78% with MR, and 77% with MR + SP. CONCLUSIONS: Postoperative complications are not related to conservative or miniresective surgery even when active disease is present at the resection margins or the site of SP. The higher risk reported for patients with low serum hemoglobin and hematocrit levels suggests that surgeons should consider using preoperative iron and vitamin support, parenteral nutrition and erythropoietin therapy, when necessary, in those cases. Our postoperative morbidity, mortality and long-term surgical recurrence rate results support the efficacy and safety of SP and MR surgery in the treatment of complicated CD. 相似文献
8.
Informed consent, parental awareness, and reasons for participating in a randomised controlled study
M van Stuijvenberg MH Suur S de Vos GC Tjiang EW Steyerberg G Derksen-Lubsen HA Moll 《Archives of disease in childhood》1998,79(2):120-125
BACKGROUND: The informed consent procedure plays a central role in randomised controlled trials but has only been explored in a few studies on children. AIM: To assess the quality of the informed consent process in a paediatric setting. METHODS: A questionnaire was sent to parents who volunteered their child (230 children) for a randomised, double blind, placebo controlled trial of ibuprofen syrup to prevent recurrent febrile seizures. RESULTS: 181 (79%) parents responded. On average, 73% of parents were aware of the major study characteristics. A few had difficulty understanding the information provided. Major factors in parents granting approval were the contribution to clinical science (51%) and benefit to the child (32%). Sociodemographic status did not influence initial participation but west European origin of the father was associated with willingness to participate in future trials. 89% of participants felt positive about the informed consent procedure; however, 25% stated that they felt obliged to participate. Although their reasons for granting approval and their evaluation of the informed consent procedure did not differ, relatively more were hesitant about participating in future. Parents appreciated the investigator being on call 24 hours a day (38%) and the extra medical care and information provided (37%) as advantages of participation. Disadvantages were mainly the time consuming aspects and the work involved (23%). CONCLUSIONS: Parents' understanding of trial characteristics might be improved by designing less difficult informed consent forms and by the investigator giving extra attention and information to non-west European parents. Adequate measures should be taken to avoid parents feeling obliged to participate, rather than giving true informed consent. 相似文献
9.
A monokine regulates colony-stimulating activity production by vascular endothelial cells 总被引:20,自引:0,他引:20
Human umbilical vein endothelial cells were cultured in supernatants of peripheral blood monocytes that had been cultured for 3 days with and without lactoferrin. Colony-stimulating activity (CSA) was measured in supernatants of the endothelial cell cultures and appropriate control cultures using normal, T-lymphocyte-depleted, phagocyte-depleted, low- density bone marrow cells in colony growth (CFU-GM) assays. Monocyte- conditioned medium contained a nondialyzable, heat labile factor that enhanced 4-15--fold the production of CSA by endothelial cells. The addition of lactoferrin to monocyte cultures reduced the activity of this monokine by 69%. Lactoferrin did not inhibit CSA production by monokine-stimulated endothelial cells. Therefore, vascular endothelial cells are potent sources of CSA, the production of CSA by these cells is regulated by a stimulatory monokine, and the production and/or release of the monokine is inhibited by lactoferrin, a neutrophil- derived putative feedback inhibitor of granulopoiesis. Inasmuch as a similar monokine is known to stimulate CSA production by fibroblasts and T lymphocytes, we suggest that mononuclear phagocytes play a pivotal role in the regulation of granulopoiesis by recruiting a variety of cell types to produce CSA. 相似文献
10.
Jihyun Lee Kristina K. Vargo David L. Porretta 《Journal of developmental and physical disabilities》2018,30(3):409-426
This study examined the effects of two types of physical activities on stereotypic behaviors (SBs) and task engagement of young children with autism spectrum disorder. Locomotor activities and object manipulation activities were applied to three preschoolers with autism spectrum disorder. A multi-element design with a three-component test sequence (Morrison et al. Journal of Applied Behavior Analysis, 44, 523–541, 2011) was used to identify changes in SBs and task engagement in the following three consecutive 5-min phases: pre-physical activity (pre-PA), physical activity (PA), and post-physical activity (post-PA). For the locomotor activity condition, all participants engaged in less SBs in post-PA compared to pre-PA, while increased SBs were observed in post-PA compared to pre-PA for the object manipulation activity condition. Positive effects of locomotor activities on task engagement were found, but the effects were clear to only one of the three participants. 相似文献