962 resultados para Hare, Robert D.: Snakes in suits
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Dissertation presented to obtain the Ph.D degree in Biology, Neuroscience
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Dissertation presented to obtain the Ph.D degree in Biology.
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Dissertation presented to obtain the Ph.D degree in Biology.
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INTRODUCTION: Lamivudine is a nucleoside analogue that is used clinically for treating chronic hepatitis B infection. However, the main problem with prolonged use of lamivudine is the development of viral resistance to the treatment. Mutations in the YMDD motif of the hepatitis B virus DNA polymerase gene have been associated with resistance to drug therapy. So far, there have not been many studies in Brazil reporting on genotype-dependent development of resistance to lamivudine. Thus, the aim of the present study was to determine the possible correlation between a certain genotype and increased development of resistance to lamivudine among chronic hepatitis B patients. METHODS: HBV DNA in samples from 50 patients under lamivudine treatment was amplified by means of conventional PCR. Samples were collected at Hospital das Clínicas, FMRP-USP. The products were then sequenced and phylogenetic analysis was performed. RESULTS: Phylogenetic analysis revealed that 29 (58%) patients were infected with genotype D, 20 (40%) with genotype A and one (2%) with genotype F. Mutations in the YMDD motif occurred in 20% of the patients with genotype A and 27.6% of the patients with genotype D. CONCLUSIONS: Despite the small number of samples, our results indicated that mutations in the YMDD motif were 1.38 times more frequent in genotype D than in genotype A.
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Fundação para a Ciência e a Tecnologia (FCT), Fundação Calouste Gulbenkian, Fundação Millennium bcp, Direcção Geral do Livro e das Bibliotecas/MC
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Iniciativa paralela à galeria de pintura criada pelo rei D. Luís no Palácio da Ajuda, em 1867, o “museu de antiguidades” conservou e expôs o essencial das colecções de numismática e ourivesaria daquele monarca, acrescidas com diversas peças pertencentes ao tesouro da Casa Real, parte das quais provenientes dos conventos extintos pelo Liberalismo. Hoje disperso por diferentes instituições museológicas, colecções particulares ou em paradeiro incerto, aquele acervo pretende ser dado a conhecer ao longo deste artigo, sobretudo no que diz respeito aos seus núcleos mais representativos, procurando-se simultaneamente reconstituir a apagada memória do espaço que o albergou, o papel desempenhado pelo seu conservador, Teixeira de Aragão, e as aquisições efectuadas. Em foco estarão também os catálogos editados, a cedência de peças para exposições nacionais e internacionais e a atenção dada por D. Luís aos novos processos fotográficos como forma de documentar e divulgar a colecção real.
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Supplementary data associated with this article can be found, in the online version, at: http://dx.doi.org/10.1016/j.electacta.2015.09.169.
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Doctoral thesis in Marketing and Strategy.
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In order to study the action of herbicides - sodium salt, amine salt and ester of 2,4-D, TCA and 2,4,5-T a preliminary experiment for pre-emergence weed control was corried out, and the corresponding results are given in table I and II. The corn used in the experiments was of the flint type 1A 3531. The loam soil on which the experiment has been carried out is called "terra roxa". All treatments were highly significant when compared with the check plots, except the 2B one in the control of broad leaf weeds, and 4B in the control of grass weeds. Among these treatments there are no significant differences. But we note the following: (table I). a) treatments of higher concentrations were superior to lower ones. b) the treatments which gave the best control for broad leaf weeds were in the following decreasing order: 1A, 5A and 3A. For grass weeds, they were 5A, 1A and 3A. c) the amine 2,4-D (600 grs. per hectare) supplied very good control when we get into consideration that on the acid basis, it was in very low concentration. d) TCA in high concentration affected the germination, growth and yield, in the lower one it did not show good control of weeds, especially of grasses. It is not suitable for pre-emergence control in corn. e) 2,4,5-T was not better than the 2,4-D products. As it is much more expensive than the others, economically its use in pre-emergence weed control in corn is not praticable. f) all the products used controled grass weeds as well as broad leaf ones; this show the superiority of the pre-emergence treatment method over that of post-emergence. g) Even a dose as strong as the treatment 1A (3.400g. of 2,4-D acid per hectare) did not damage corn production (table II). h) the superiority noted in the production of all the treatments with the exception of 2A, which damaged the plants, we atribute to the lack of competion between corn and weeds; all chek-plots suffered this competition, because they were not Probably, there was, also, hormonial effect of 2,4-D on the corn plant. Not withstanding the fact that the present experiment has been successful, we think that new researches are necessary, especially with the purpose of studying factors as climate and soil which in other countries, interferred with the success of the pre-emergence weed control.
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This paper explores the effects of two main sources of innovation -intramural and external R&D- on the productivity level in a sample of 3,267 Catalonian firms. The data set used is based on the official innovation survey of Catalonia which was a part of the Spanish sample of CIS4, covering the years 2002-2004. We compare empirical results by applying usual OLS and quantile regression techniques both in manufacturing and services industries. In quantile regression, results suggest different patterns at both innovation sources as we move across conditional quantiles. The elasticity of intramural R&D activities on productivity decreased when we move up the high productivity levels both in manufacturing and services sectors, while the effects of external R&D rise in high-technology industries but are more ambiguous in low-technology and knowledge-intensive services. JEL codes: O300, C100, O140. Keywords: Innovation sources, R&D, Productivity, Quantile regression
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Background: Immunosuppressive and antivira[ prophy[ actic drugs are needed to prevent acute rejection and infection after organ transplantation. We assessed the effectiveness of a new combined regimen introduced at our transplantation center. Methods: We reviewed at[ consecutive patients who underwent kidney transplantation at our institution over a 5.5-year period, with a follow-up of at [east 6 months. Patients transplanted from 1/2000 to 3/2003 (Period 1) were compared to patients transplanted from 4/2003 to 7/2005 (Period 2). In period 1, patients were treated with Basi[iximab, Cic[osporin, steroids and Mycophenotate or Azathioprine. Prophylaxis with Va[acic[ ovir was prescribed in CMV D+/R- patients; otherwise, a preemptive antivira[ approach was used. In period 2, immunosuppressive drugs were Basi[- iximab, Tacro[imus, steroids and Mycopheno[ate. A 3-month CMV prophylaxis with Va[gancic[ovir was used, except in D-/R- patients. Results: Sixty-three patients were transplanted in period 1 and 70 patients in period 2. Baseline characteristics of both groups were comparable; in particular 17% of patients were CMV D+/R- in period 1 compared to 23% in period 2 (p=0.67). Acute rejection was more frequent in period 1 than in period 2 (40% of patients vs 7%, respectively p<0.001). Nineteen patients (30%) in period 1 were diagnosed with CMV infection/disease that required treatment, compared with 8 patients (11.4%) in period 2 (p = 0.003). Of these 8 patients, at[ had CMV infection/disease after discontinuation of Va[gancic[ovir prophylaxis, 6 were D+/R- (75%), and at[ were treated with oral Va[gancic[ovir. There was no difference between periods in terms of incidence of BK nephropathy, post-transplant [ymphopro[ iferative disease, graft toss, and mortality. Conclusions: These results indicate that a 3-month course of oral Va[gancic[ovir is very effective to prevent CMV infection/disease in kidney transplantation. Late-onset CMV disease is a residual problem in D+/R- patients receiving VGC prophylaxis.
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Report for the scientific sojourn carried out at the Max Planck Institut of Molecular Phisiology, Germany, from 2006 to 2008.The work carried out during this postdoctoral stage was focused on two different projects. Firstly, identification of D-Ala D-Ala Inhibitors and the development of new synthethic approaches to obtain lipidated peptides and proteins and the use of these lipidated proteins in biological and biophysical studies. In the first project, new D-Ala D-Ala inhibitors were identified by using structural alignments of the ATP binding sites of the bacterial ligase DDl and protein and lipid kinases in complex with ATP analogs. We tested a series of commercially available kinase inhibitors and found LFM-A13 and Tyrphostine derivatives to inhibit DDl enzyme activity. Based on the initial screening results we synthesized a series of malononitrilamide and salicylamide derivatives and were able to confirm the validity of these scaffolds as inhibitors of DDl. From this investigation we gained a better understanding of the structural requirements and limitations necessary for the preparation of ATP competitive DDl inhibitors. The compounds in this study may serve as starting points for the development of bi-substrate inhibitors that incorporate both, an ATP competitive and a substrate competitive moiety. Bisubstrate inhibitors that block the ATP and D-Ala binding sites should exhibit enhanced selectivity and potency profiles by preferentially inhibiting DDl over kinases. In the second project, an optimized synthesis for tha alkylation of cysteins using the thiol ene reaction was establisehd. This new protocol allowed us to obtain large amounts of hexadecylated cysteine that was required for the synthesis of differently lipidated peptides. Afterwards the synthesis of various N-ras peptides bearing different lipid anchors was performed and the peptides were ligated to a truncated N-ras protein. The influence of this differently lipidated N-ras proteins on the partioning and association of N-Ras in model membrane subdomains was studied using Atomic Force Microscopy.
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Recent studies have demonstrated the immunomodulatory properties of vitamin D, and vitamin D deficiency may be a risk factor for the development of MS. The risk of developing MS has, in fact, been associated with rising latitudes, past exposure to sun and serum vitamin D status. Serum 25-hydroxyvitamin D [25(OH)D] levels have also been associated with relapses and disability progression. The identification of risk factors, such as vitamin D deficiency, in MS may provide an opportunity to improve current treatment strategies, through combination therapy with established MS treatments. Accordingly, vitamin D may play a role in MS therapy. Small clinical studies of vitamin D supplementation in patients with MS have reported positive immunomodulatory effects, reduced relapse rates and a reduction in the number of gadolinium-enhancing lesions. However, large randomized clinical trials of vitamin D supplementation in patients with MS are lacking. SOLAR (Supplementation of VigantOL(®) oil versus placebo as Add-on in patients with relapsing-remitting multiple sclerosis receiving Rebif(®) treatment) is a 96-week, three-arm, multicenter, double-blind, randomized, placebo-controlled, Phase II trial (NCT01285401). SOLAR will evaluate the efficacy of vitamin D(3) as add-on therapy to subcutaneous interferon beta-1a in patients with RRMS. Recruitment began in February 2011 and is aimed to take place over 1 calendar year due to the potential influence of seasonal differences in 25(OH)D levels.
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PURPOSE: Transanal endoscopic microsurgery provides a minimally invasive alternative to radical surgery for excision of benign and malignant rectal tumors. The purpose of this study was to review our experience with transanal endoscopic microsurgery to clarify its role in the treatment of different types of rectal pathology. METHODS: A prospective database documented all patients undergoing transanal endoscopic microsurgery from October 1996 through June 2008. We analyzed patient and operative factors, complications, and tumor recurrence. For recurrence analysis, we excluded patients with fewer than 6 months of follow-up, previous excisions, known metastases at initial presentation, and those who underwent immediate radical resection following transanal endoscopic microsurgery. RESULTS: Two hundred sixty-nine patients underwent transanal endoscopic microsurgery for benign (n = 158) and malignant (n = 111) tumors. Procedure-related complications (21%) included urinary retention (10.8%), fecal incontinence (4.1%), fever (3.8%), suture line dehiscence (1.5%), and bleeding (1.5%). Local recurrence rates for 121 benign and 83 malignant tumors were 5% for adenomas, 9.8% for T1 adenocarcinoma, 23.5% for T2 adenocarcinoma, 100% for T3 adenocarcinoma, and 0% for carcinoid tumors. All 6 (100%) recurrent adenomas were retreated with endoscopic techniques, and 8 of 17 (47%) recurrent adenocarcinomas underwent salvage procedures with curative intent. CONCLUSIONS: Transanal endoscopic microsurgery is a safe and effective method for excision of benign and malignant rectal tumors. Transanal endoscopic microsurgery can be offered for (1) curative resection of benign tumors, carcinoid tumors, and select T1 adenocarcinomas, (2) histopathologic staging in indeterminate cases, and (3) palliative resection in patients medically unfit or unwilling to undergo radical resection.
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Non-indigenous species can have strong impacts on biodiversity by affecting trophic relationships in their new environments. The piscivorous dice snake (Natrix tessellata) has been introduced to Geneva Lake, western Switzerland, where the endangered viperine snake (Natrix maura) is native. Local, dramatic declines in the viperine snake population might be associated with the appearance of the dice snake through dietary overlap between these 2 species, which mainly feed on bullhead (Cottus gobio). In response to this decline, a control program for dice snake was implemented in 2007 to reduce numbers of this introduced snake. In 2010, a new species of fish, the freshwater blenny (Salaria fluviatilis), which shares the same habitat as the bullhead, was introduced into Lake Geneva and has since reached high densities. We determined the impact of freshwater blenny on diet composition and body condition of dice snakes. In addition, we tested for effects of the control program on the body condition of dice snakes and viperine snakes. We collected 294 dice snakes between 2007 and 2013. Based on morphology and a genetic marker (cytochrome b gene), we determined the ®sh species contained in these snakes' stomachs. We found a drastic switch in dice snake diet following the arrival of freshwater blenny, as consumption of bullhead declined by 68% and was replaced by the blenny. In addition, the body condition of dice snakes increased significantly after the arrival of freshwater blenny. The body condition of both snake species was positively correlated with the number of dice snakes removed from the study area. This finding has important implications concerning the conservation of the endangered viperine snake, and suggests that the control program of dice snakes should be continued.