229 research outputs found
Chirality in charge-transfer salts of BEDT-TTF of tris(oxalato)chromate(III)
Crystallisation from chiral electrolyte (R)-(−)-carvone has produced three new chiral semiconducting salts of BEDT-TTF from racemic anion tri(oxalato)chromate(III)
Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans
Rabies kills many people throughout the developing world every year. The murine monoclonal antibody (mAb) 62-71-3 was recently identified for its potential application in rabies postexposure prophylaxis (PEP). The purpose here was to establish a plant-based production system for a chimeric mouse-human version of mAb 62-71-3, to characterize the recombinant antibody and investigate at a molecular level its interaction with rabies virus glycoprotein. Chimeric 62-71-3 was successfully expressed in Nicotiana benthamiana. Glycosylation was analyzed by mass spectroscopy; functionality was confirmed by antigen ELISA, as well as rabies and pseudotype virus neutralization. Epitope characterization was performed using pseudotype virus expressing mutagenized rabies glycoproteins. Purified mAb demonstrated potent viral neutralization at 500 IU/mg. A critical role for antigenic site I of the glycoprotein, as well as for two specific amino acid residues (K226 and G229) within site I, was identified with regard to mAb 62-71-3 neutralization. Pseudotype viruses expressing glycoprotein from lyssaviruses known not to be neutralized by this antibody were the controls. The results provide the molecular rationale for developing 62-71-3 mAb for rabies PEP; they also establish the basis for developing an inexpensive plant-based antibody product to benefit low-income families in developing countries.—Both, L., van Dolleweerd, C., Wright, E., Banyard, A. C., Bulmer-Thomas, B., Selden, D., Altmann, F., Fooks, A. R., Ma, J. K.-C. Production, characterization, and antigen specificity of recombinant 62-71-3, a candidate monoclonal antibody for rabies prophylaxis in humans
Stress ocupacional no ensino : um estudo com professores dos 3º ciclo e ensino secundário
Este trabalho foi realizado com 689 professores portugueses, a leccionarem nos terceiro ciclo e ensino secundário. Foram avaliados indicadores de stress, “burnout”, saúde física e satisfação profissional. Observaram-se valores significativos de stress ocupacional (perto de 40%), e de “burnout” (10% na exaustão emocional, 3% na baixa realização pessoal e 1% na despersonalização), vários problemas de saúde física e valores de insatisfação profissional perto dos 20%. As análises de regressão múltipla apontaram diferentes variáveis preditoras para as três dimensões do “burnout” (62% de variância explicada na exaustão emocional, 16% na realização pessoal e 13% na despersonalização). As análises discriminantes e “t-test” para amostras independentes demonstraram maior stress ocupacional nas mulheres, nos professores mais velhos, nos profissionais com vínculos profissionais mais precários, nos professores com mais horas de trabalho e com mais alunos em sala de aula. No final, apresentam-se as limitações do estudo e as implicações para a investigação futura.(undefined
Whole-body tissue stabilization and selective extractions via tissue-hydrogel hybrids for high-resolution intact circuit mapping and phenotyping
To facilitate fine-scale phenotyping of whole specimens, we describe here a set of tissue fixation-embedding, detergent-clearing and staining protocols that can be used to transform excised organs and whole organisms into optically transparent samples within 1–2 weeks without compromising their cellular architecture or endogenous fluorescence. PACT (passive CLARITY technique) and PARS (perfusion-assisted agent release in situ) use tissue-hydrogel hybrids to stabilize tissue biomolecules during selective lipid extraction, resulting in enhanced clearing efficiency and sample integrity. Furthermore, the macromolecule permeability of PACT- and PARS-processed tissue hybrids supports the diffusion of immunolabels throughout intact tissue, whereas RIMS (refractive index matching solution) grants high-resolution imaging at depth by further reducing light scattering in cleared and uncleared samples alike. These methods are adaptable to difficult-to-image tissues, such as bone (PACT-deCAL), and to magnified single-cell visualization (ePACT). Together, these protocols and solutions enable phenotyping of subcellular components and tracing cellular connectivity in intact biological networks
The measuring systems of the wire tension for the MEG II Drift Chamber by means of the resonant frequency technique
The ultra-low mass Cylindrical Drift Chamber designed for the MEG experiment
upgrade is a challenging apparatus made of 1728 phi = 20 micron gold plated
tungsten sense wires, 7680 phi = 40 micron and 2496 phi = 50 micron silver
plated aluminum field wires. Because of electrostatic stability requirements
all the wires have to be stretched at mechanical tensions of about 25, 19 and
29 g respectively which must be controlled at a level better than 0.5 g. This
chamber is presently in acquisition, but during its construction about 100
field wires broke, because of chemical corrosion induced by the atmospheric
humidity. On the basis of the experience gained with this chamber we decided to
build a new one, equipped with a different type of wires less sensitive to
corrosion. The choice of the new wire required a deep inspection of its
characteristics and one of the main tools for doing this is a system for
measuring the wire tension by means of the resonant frequency technique, which
is described in this paper. The system forces the wires to oscillate by
applying a sinusoidal signal at a known frequency, and then measures the
variation of the capacitance between a wire and a common ground plane as a
function of the external signal frequency. We present the details of the
measuring system and the results obtained by scanning the mechanical tensions
of two samples of MEG II CDCH wires and discuss the possible improvements of
the experimental apparatus and of the measuring technique.Comment: Ten pages, twelve figures, to be submitted to Nuclear Instruments and
Methods
Performances of a new generation tracking detector: the MEG II cylindrical drfit chamber
The cylindrical drift chamber is the most innovative part of the MEG~II
detector, the upgraded version of the MEG experiment. The MEG~II chamber
differs from the MEG one because it is a single volume cylindrical structure,
instead of a segmented one, chosen to improve its resolutions and efficiency in
detecting low energy positrons from muon decays at rest. In this paper, we show
the characteristics and performances of this fundamental part of the MEG~II
apparatus and we discuss the impact of its higher resolution and efficiency on
the sensitivity of the MEG~II experiment. Because of its innovative structure
and high quality resolution and efficiency the MEG~II cylindrical drift chamber
will be a cornerstone in the development of an ideal tracking detector for
future positron-electron collider machines.Comment: 27 pages, 41 figures, to be submitted to EPJ
uMoDT: an unobtrusive multi-occupant detection and tracking using robust Kalman filter for real-time activity recognition
Performances of a new generation tracking detector: the MEG II cylindrical drift chamber
The cylindrical drift chamber is the most innovative part of the MEG II detector, the upgraded version of the MEG experiment. The MEG II chamber differs from the MEG one because it is a single volume cylindrical structure, instead of a segmented one, chosen to improve its resolutions and efficiency in detecting low energy positrons from muon decays at rest. In this paper, we show the characteristics and performances of this fundamental part of the MEG II apparatus and we discuss the impact of its higher resolution and efficiency on the sensitivity of the MEG II experiment. Because of its innovative structure and high quality resolution and efficiency the MEG II cylindrical drift chamber will be a cornerstone in the development of an ideal tracking detector for future positron-electron collider machines
Genetic Resistance to Rhabdovirus Infection in Teleost Fish Is Paralleled to the Derived Cell Resistance Status
Genetic factors of resistance and predisposition to viral diseases explain a significant part of the clinical variability observed within host populations. Predisposition to viral diseases has been associated to MHC haplotypes and T cell immunity, but a growing repertoire of innate/intrinsic factors are implicated in the genetic determinism of the host susceptibility to viruses. In a long-term study of the genetics of host resistance to fish rhabdoviruses, we produced a collection of double-haploid rainbow trout clones showing a wide range of susceptibility to Viral Hemorrhagic Septicemia Virus (VHSV) waterborne infection. The susceptibility of fibroblastic cell lines derived from these clonal fish was fully consistent with the susceptibility of the parental fish clones. The mechanisms determining the host resistance therefore did not associate with specific host immunity, but rather with innate or intrinsic factors. One cell line was resistant to rhabdovirus infection due to the combination of an early interferon IFN induction - that was not observed in the susceptible cells - and of yet unknown factors that hamper the first steps of the viral cycle. The implication of IFN was well consistent with the wide range of resistance of this genetic background to VSHV and IHNV, to the birnavirus IPNV and the orthomyxovirus ISAV. Another cell line was even more refractory to the VHSV infection through different antiviral mechanisms. This collection of clonal fish and isogenic cell lines provides an interesting model to analyze the relative contribution of antiviral pathways to the resistance to different viruses
Pharmacokinetic Modeling of Non-Linear Brain Distribution of Fluvoxamine in the Rat
Introduction. A pharmacokinetic (PK) model is proposed for estimation of total and free brain concentrations of fluvoxamine. Materials and methods. Rats with arterial and venous cannulas and a microdialysis probe in the frontal cortex received intravenous infusions of 1, 3.7 or 7.3 mg.kg j1 of fluvoxamine. Analysis. With increasing dose a disproportional increase in brain concentrations was observed. Th
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