263 research outputs found
New England's small cities: a mostly untapped resource
With a different policy mind-set, small cities could boost the region’s overall competitiveness and provide appealing alternatives for suburbanites tired of living behind the wheel of a car.Cities and towns - New England ; Economic policy - New England
Controlled synthesis of CoFe2O4 nano-octahedra
International audienceNano-octahedral grains of cobalt ferrite (CoFe2O4) with size around 20 nm were synthesized by a hydrothermal route. X-rays and electron diffraction, along with scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy and thermogravimetric analysis were used to characterize the powders. Images and simulations of high-resolution electron microscopy allowed the identification of the shape of the grains. Process parameters such as temperature and time of reaction, reagents concentration, and pH of the reacting medium were optimized. The surfactant cetyltrimethylammonium bromide (CTAB) hindered the formation of goethite, which favored the production of a pure CoFe2O4 powder. The oxidation state of cobalt atoms on the ferrite structure was also influenced by CTAB. The control of the shape of the grains was associated mainly to the nature of the precipitating agent
Structure-based virtual screening to get new scaffold inhibitors of the Ser/Thr protein kinase PknB from mycobacterium tuberculosis
In search of new inhibitors of the Ser/Thr protein kinase PknB from Mycobacterium tuberculosis we carried out a structure-based virtual screening study to identify ATP-competitive inhibitors of this enzyme. These studies point out that N-phenylmethylindole-2-carboxamide is a promising scaffold for the development of new PknB inhibitors. We synthesized a small set of analogue compounds to assess the pharmacophore structural requirements and to optimize the inhibitory activity against PknB. This strategy led to the identification of compound 3, endowed with an IC50 of 20 ÎĽM, which provides a novel scaffold for further improvement of PknB inhibitors
Immune responses in healthy adults elicited by a bivalent norovirus vaccine candidate composed of GI.4 and GII.4 VLPs without adjuvant
The development of an efficacious vaccine against norovirus is of paramount importance given its potential to reduce the global burden of norovirus-associated morbidity and mortality. Here, we report a detailed immunological analysis of a phase I, double-blind, placebo-controlled clinical trial performed on 60 healthy adults, ages 18 to 40. Total serum immunoglobulin and serum IgA against vaccine strains and cross-reactive serum IgG against non-vaccine strains were measured by enzyme immunoassays, whereas cell-mediated immune responses were quantified using intracellular cytokine staining by flow cytometry. A significant increase in humoral and cellular responses, e.g., IgA and CD4+ polypositive T cells, was triggered by the GI.4 Chiba 407 (1987) and GII.4 Aomori 2 (2006) VLP-based norovirus vaccine candidate rNV-2v, which is formulated without adjuvant. No booster effect was observed after the second administration in the pre-exposed adult study population. Furthermore, a cross-reactive immune response was elicited, as shown by IgG titers against GI.3 (2002), GII.2 OC08154 (2008), GII.4 (1999), GII.4 Sydney (2012), GII.4 Washington (2018), GII.6 Maryland (2018), and GII.17 Kawasaki 308 (2015). Due to viral infection via mucosal gut tissue and the high variety of potentially relevant norovirus strains, a focus should be on IgA and cross-protective humoral and cell-mediated responses in the development of a broadly protective, multi-valent norovirus vaccine.Clinical trial registrationhttps://clinicaltrials.gov, identifier NCT05508178. EudraCT number: 2019-003226-25
On the simulation of enzymatic digest patterns: the fragmentation of oligomeric and polymeric galacturonides by endo-polygalacturonase II
A simulation methodology for predicting the time-course of enzymatic
digestions is described. The model is based solely on the enzyme's subsite
architecture and concomitant binding energies. This allows subsite binding
energies to be used to predict the evolution of the relative amounts of
different products during the digestion of arbitrary mixtures of oligomeric or
polymeric substrates. The methodology has been specifically demonstrated by
studying the fragmentation of a population of oligogalacturonides of varying
degrees of polymerization, when digested by endo-polygalacturonase II (endo-PG
II) from Aspergillus niger.Comment: Preprint - has been accepted to Biochimica et Biophysica Act
A role for B cells to transmit hepatitis C virus infection
Hepatitis C virus (HCV) is highly variable and transmits through infected blood to establish a chronic liver infection in the majority of patients. Our knowledge on the infectivity of clinical HCV strains is hampered by the lack of in vitro cell culture systems that support efficient viral replication. We and others have reported that HCV can associate with and infect immune cells and may thereby evade host immune surveillance and elimination. To evaluate whether B cells play a role in HCV transmission, we assessed the ability of B cells and sera from recent (<2 years) or chronic (≥ 2 years) HCV patients to infect humanized liver chimeric mice. HCV was transmitted by B cells from chronic infected patients whereas the sera were non-infectious. In contrast, B cells from recently infected patients failed to transmit HCV to the mice, whereas all serum samples were infectious. We observed an association between circulating anti-glycoprotein E1E2 antibodies and B cell HCV transmission. Taken together, our studies provide evidence for HCV transmission by B cells, findings that have clinical implications for prophylactic and therapeutic antibody-based vaccine design
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