568 research outputs found
Congenital Cytomegalovirus Infection: A Narrative Review of the Issues in Screening and Management From a Panel of European Experts.
Maternal primary and non-primary cytomegalovirus (CMV) infection during pregnancy can result in in utero transmission to the developing fetus. Congenital CMV (cCMV) can result in significant morbidity, mortality or long-term sequelae, including sensorineural hearing loss, the most common sequela. As a leading cause of congenital infections worldwide, cCMV infection meets many of the criteria for screening. However, currently there are no universal programs that offer maternal or neonatal screening to identify infected mothers and infants, no vaccines to prevent infection, and no efficacious and safe therapies available for the treatment of maternal or fetal CMV infection. Data has shown that there are several maternal and neonatal screening strategies, and diagnostic methodologies, that allow the identification of those at risk of developing sequelae and adequately detect cCMV. Nevertheless, many questions remain unanswered in this field. Well-designed clinical trials to address several facets of CMV treatment (in pregnant women, CMV-infected fetuses and both symptomatic and asymptomatic neonates and children) are required. Prevention (vaccines), biology and transmission factors associated with non-primary CMV, and the cost-effectiveness of universal screening, all demand further exploration to fully realize the ultimate goal of preventing cCMV. In the meantime, prevention of primary infection during pregnancy should be championed to all by means of hygiene education
Effect of treatment with hcl/alcoholic in the modification of corn starch.
Corn is the cereal most produced in the world. Corn starches were modified by HCl 0.1 mol L-1 in alcoholic and aqueous solutions. Three mass losses can be observed in the degradation process using TG-DTG curve. The native and treated starches samples don't show differences in the stability region. With DSC curves were observed lower values of the ΔH of gelatinization of the modified starch by HCl in the alcoholic solutions. The modifications using alcoholic solutions demonstrated a good alternative to obtain modifies starches.Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru
UV-Induced Structural Changes of Model DNA Helices Probed by Optical Spectroscopy
International audienceChemical alterations of DNA, if not repaired, may lead to carcinogenic mutations. Structural modifications of the helix around the lesion enable its recognition by repair enzymes. We have used absorption spectroscopy and mass spectrometry to detect structural changes provoked by cyclobutane thymine dimers, the major lesion induced by UV radiation. We found that formation of a cyclobutane dimer in the model duplex (dA)20 · (dT)20 destroys base stacking on the adenine strand. The physical background of this novel approach is the existence of charge-transfer states among neighboring bases, whose contribution to the hypochromism of the helix disappears following destacking
Epidemiology and In Vitro Activity of Ceftazidime/Avibactam, Meropenem/Vaborbactam and Imipenem/Relebactam against KPC-Producing K. pneumoniae Collected from Bacteremic Patients, 2018 to 2020
The management of KPC-producing K. pneumoniae (KPC-Kp) in bloodstream infections (BSIs) represent a serious clinical challenge. In this study, the aim is to assess the incidence of resistance to novel β-lactams-β-lactamase inhibitor combinations (βL-βLICs), such as ceftazidime-avibactam (CAZ-AVI), meropenem-vaborbactam (MER-VAB) and imipenem-relebactam (IMI-REL), in KPC-Kp strains collected during a three-year period from patients with bacteremia. KPC-Kp strains resistant to βL-βLICs were selected for whole-genome sequencing. A total of 133 K. pneumoniae strains were isolated, and KPC-Kp strains were the most represented (87.2%). In 2018, resistance to CAZ-AVI and MER-VAB was 6.5% and 14.5%, respectively. In 2019, KPC-Kp resistance to CAZ-AVI and MER-VAB remained at low levels, with values of 12.9% and 3.2%, respectively. During 2020, CAZ-AVI resistance was detected in 2/23 of KPC-Kp strains (8.7%). IMI-REL was the most active βL-βLIC, inhibiting >98% of the isolates, while CAZ-AVI and MER-VAB inhibited 87-93% and 85-97% of the KPC producers, respectively. Correlations between genotypic traits and resistance to βL-βLICs showed that KPC-Kp strains resistant to CAZ-AVI harbored a mutation within the blaKPC-3 gene, while all KPC-Kp strains resistant to CAZ-AVI, MER-VAB and/or IMI-REL carried the blaKPC-3 gene. Moreover, genetic analysis of porin genes showed that 14/16 of KPC-Kp resistant isolates possessed a truncated OmpK35 and glycine (G) and aspartic acid (D) insertions at positions 134-135 within OmpK36, whereas 2/16 displayed truncated OmpK35 and OmpK36 porins. Novel βL-βLICs are promising agents against KPC-Kp infections; however, the emergence of resistance to these agents highlights the need for continuous surveillance and application of enhanced antimicrobial stewardship
Thermal tools to evaluation of decayed and weathered wood polymer composites prepared by in situ polymerization.
This study aims to apply thermal tools in the evaluation of decayed and weathered wood polymer composites prepared by in situ polymerization of methyl methacrylate (MMA) using glycidyl methacrylate (GMA) and methacrylic acid (MAA) as cross-linkers. The pine wood samples were impregnated in a vacuum/pressure system and polymerized in an oven at 90°C for 10h, using benzoyl peroxide at 1.5 wt% as catalyst. The untreated wood and composites were exposed to in vitro decay tests with Trametes versicolor and Gloeophyllum trabeum fungi, and to artificial weathering. The weight loss after tests was measured, and the characterization was performed by thermogravimetric (TGA) and differential scanning calorimetry (DSC) analysis. The mass loss caused by exposure to fungi was evidently higher in untreated wood in relation to the composites, ~2.5 to 10 times - the composites with GMA and MAA showed the highest resistance to both fungi. The composites without cross-linkers showed the higher mass loss in the artificial weathering tests (>11%), due to the leaching of part of poly(MMA) formed inside wood. By TGA and DSC analysis, we observed shifting in the temperature of thermal events related to polysaccharides and lignin after exposed to decays tests ? more significant changes were for Trametes versicolor tests. The thermograms related to weathered samples showed different results for each composite. The untreated wood and the composite without cross-linker presented loss in lignin, meanwhile the composites with cross-linkers presented degradation in the copolymer formed onto surface of wood. Keywords: TGA, DSC, pinewood, methacrylate, additivesCBRATEC
Singlet excited state dynamics of uracil and thymine derivatives: A femtosecond fluorescence upconversion study in acetonitrile
The excited state properties of uracil, thymine and four analogous uracil compounds have been studied in acetonitrile by steady-state and time-resolved spectroscopy. The excited state lifetimes were measured using femtosecond UV fluorescence upconversion. The excited state lifetimes of uracil and its 1- and 3-methyl substituted derivatives are well described by one ultrafast (6100 fs) component. Five substituted compounds show a more complex behavior, exhibiting longer excited state lifetimes and bi-exponential fluorescence decays. These longer decays are substantially faster in acetonitrile than in aqueous solution showing that the excited state deactivation mechanism is in part governed by the solvent
Thermal analysis of byproducts from fast-pyrolysis of Eucalyptus flour.
Fast pyrolysis is the thermal decomposition of biomass in the absence of oxygen. This study aims to evaluate thermal analysis of byproducts from fast-pyrolysis of Eucalyptus wood fines. The pyrolysis was conducted in a pilot-scale at 500°C and 100 mm H2O. Charcoal from this process showed high ash content (over than 20%) and incomplete carbonization. Aqueous extract and bio-oil showed similar thermal decomposition events. However, mass percentage decomposed at each temperature was different between these samples.Edição dos Anais do 7º Simpósio de Análise Térmica, 2015, Bauru
JAK-2 inhibitors and allogeneic transplant in myelofibrosis
7The activation of the JAK1/JAK2 pathway plays a crucial role in the pathogenesis of myelofibrosis. Treatment with the JAK2 inhibitor ruxolitinib demonstrated to reduce splenomegaly and symptoms in patients affected by myelofibrosis, leading to a significant improvement of overall survival in comparison with the supportive therapies. Taking in account this recent therapeutic progress, it is necessary to redefine the role of the allogeneic hematopoietic stem cell transplantation, which has been considered the only curative option for fit myelofibrosis patients up to now. In the era of JAK2 inhibitors, allogeneic transplant is still indicated in patients with intermediate-2 and high-risk myelofibrosis or red blood cell transfusion dependent patients or patients with unfavourable karyotype. There is no direct evidence to recommend which conditioning regimen should be preferentially adopted. Graft failure, relapse and transplant related mortality are still current issues of the allogeneic stem cell transplantation, particularly from unrelated donors. Ruxolitinib can be efficaciously included in the platform of allogeneic transplant. In fact, ruxolitinib treatment for 3-4 months before transplant has demonstrated to reduce spleen and improve performance status in about 30-50% of patients, without impairing the outcome of the subsequent transplant. Ruxolitinib has to stopped the day before conditioning to avoid rebound phenomenon. There are no sufficient data to recommend ruxolitinib administration after transplant with the aim of eradicating minimal residual disease and preventing relapse.openopenPatriarca, F; Sperotto, A; De Marchi, R; Perali, G; Cigana, C; Lazzarotto, D; Fanin, RPatriarca, Francesca; Sperotto, A; De Marchi, R; Perali, G; Cigana, C; Lazzarotto, D; Fanin, Renat
Caracterização térmica e comparação da composição de óleos essenciais provenientes de folhas secas e frescas de eucalipto.
O óleo essencial de eucalipto possui amplo espectro de utilização no mercado atual. O inseto psilídeo (Glycaspis brimblecombei) tem sido alvo de muitos estudos recentes, uma vez que o dano causado ao plantio de eucalipto pode inviabilizar o uso. Em estudo anterior realizado por nosso grupo de pesquisa, relacionamos a resistência dos eucaliptos com as características térmicas de seus óleos essenciais extraídos das folhas secas. O presente trabalho tem como objetivo comparar a composição de óleos essenciais de eucaliptos provenientes de folhas frescas e secas, tendo em vista que o psilídeo ataca as folhas frescas de eucaliptos. Para isso foram extraídos óleos essenciais de folhas frescas e secas de três espécies de eucaliptos e realizada análise de TG-DTA. Para ambas espécies foi comum a perda de massa em temperatura menor para os óleos essencias de folhas secas, e curvas DTA com diferentes perfis, o que demostra uma composição química diferente para os óleos essenciais das folhas frescas e secas. Estudos adicionais são necessários para caracterização e identificação dos compostos presentes nestes óleos essenciais
Thermal tool for evaluation of essential oils of Eucalyptus spp susceptible and resistant to Glycaspis brimblecombei attack.
Eucalyptus spp genus is economically important to different industry fields. There are pests that damage the development of eucalypts and Glycaspis brimblecombei, a sap-sucking insect, is one of them. Studies about this insect attack to the eucalypts showed preferences. This work aim was to compare the preferences of the insect with thermoanalytical characteristics of different eucalypts (susceptible, less susceptible and resistant to Glycaspis brimblecombei) essential oils. The leaves of six species of Eucalyptus were crushed and the essential oil was extracted using Clevenger apparatus. The Shimadzu DTG-60H was used to analyze the samples. The results showed that the samples from more susceptible eucalypts had total mass loss at about 124ºC to 156ºC, lower than samples from more resistant eucalypts (from 168ºC to 175ºC). Furthermore, the study suggests that the susceptibility or the resistance of eucalypts to the pest may be related to their essential oil composition and concentration of monoterpenes and sesquiterpenes.Disponível online
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