456 research outputs found
Toll-like receptor stimulation induces higher TNF-alpha secretion in peripheral blood mononuclear cells from patients with hyper IgE syndrome
Hyper IgE syndromes (HIES) are primary immunodeficiency disorders of unknown pathogenesis. Patients are typically affected with `cold' abscesses of the skin, recurrent cyst-forming pneumonia, chronic mucocutaneous candidiasis and other less frequent features such as progressive skeletal abnormalities. Defective signaling in the Toll-like receptor (TLR) pathways has been suggested as a responsible pathologic mechanism, however, in previous reports, 10 patients revealed no defect in inflammatory cytokine responses to different TLR ligands. Here, we report the increase in pro-inflammatory cytokines TNF-alpha and IL-8, following TLR2 and TLR4 stimulation in a larger cohort of 25 additional patients with HIES, and provide a meta-analysis of the TLR data in HIES. Copyright (C) 2008 S. Karger AG, Basel
Strong polarization-induced reduction of addition energies in single-molecule nanojunctions
We address polarization-induced renormalization of molecular levels in
solid-state based single-molecule transistors and focus on an organic conjugate
molecule where a surprisingly large reduction of the addition energy has been
observed. We have developed a scheme that combines a self-consistent solution
of a quantum chemical calculation with a realistic description of the screening
environment. Our results indeed show a large reduction, and we explain this to
be a consequence of both (a) a reduction of the electrostatic molecular
charging energy and (b) polarization induced level shifts of the HOMO and LUMO
levels. Finally, we calculate the charge stability diagram and explain at a
qualitative level general features observed experimentally.Comment: 9 pages, 5 figure
Molecular identification of bacterial and fungal pathogens in certain disease-free shrimp
At present, the aquaculture industry to provide proper instructions in the field of health management, including production of Specific Pathogen Free shrimp (SPF), require sensitive and reliable methods for the detection and identification of pathogenic microorganisms. Molecular methods which used in the detection of microorganisms have a high discriminatory power in the taxonomy and in relation to libraries in the world. On the other hand, the accurate identification of microorganisms, providing the genetic data bank of shrimp pathogens and maintenance of these strains is the step to promote further research on the mechanisms of pathogenesis of pathogens, diagnosis, treatment, prevention of disease, identify indigenous production kits, diagnosis re emerging and emerging diseases and their origin. Therefore, in this project, by using ribotyping technique, native isolated pathogenic bacteria and fungi were identified and recorded in the gene bank database center. During sampling of shrimp and water of Specific Pathogen Free shrimp center, 40 bacterial strains were isolated, which 8 of them had the most frequency and identification based on 16S rDNA sequencing was performed. Bacteria identified are: Vibrio nigripulchritudo strain IS013(GenBank:KP843725), Vibrio brasiliensis strain IS014 (GenBank:KR186076), Vibrio rotiferianus strain IS015 (GenBank:KR186077), Vibrio azureus strain IS012 (GenBank:KJ018724.1), Vibrio owensii strain IS016 (GenBank:KR186078), Agarivorans gilvus strain IS017 (GenBank:KR186079), Vibrio brasiliensis IS018 (GenBank:KR186080) and Vibrio alginolyticus strain IS019 (GenBank:1817854), which were recorded in The World Bank genes. In this study fungal isolates were not detected
Electrical manipulation of spin states in a single electrostatically gated transition-metal complex
We demonstrate an electrically controlled high-spin (S=5/2) to low-spin
(S=1/2) transition in a three-terminal device incorporating a single Mn2+ ion
coordinated by two terpyridine ligands. By adjusting the gate-voltage we reduce
the terpyridine moiety and thereby strengthen the ligand-field on the Mn-atom.
Adding a single electron thus stabilizes the low-spin configuration and the
corresponding sequential tunnelling current is suppressed by spin-blockade.
From low-temperature inelastic cotunneling spectroscopy, we infer the
magnetic excitation spectrum of the molecule and uncover also a strongly
gate-dependent singlet-triplet splitting on the low-spin side. The measured
bias-spectroscopy is shown to be consistent with an exact diagonalization of
the Mn-complex, and an interpretation of the data is given in terms of a
simplified effective model.Comment: Will appear soon in Nanoletter
Mid-mantle deformation inferred from seismic anisotropy
With time, convective processes in the Earth's mantle will tend to align crystals, grains and inclusions. This mantle fabric is detectable seismologically, as it produces an anisotropy in material properties—in particular, a directional dependence in seismic-wave velocity. This alignment is enhanced at the boundaries of the mantle where there are rapid changes in the direction and magnitude of mantle flow, and therefore most observations of anisotropy are confined to the uppermost mantle or lithosphere and the lowermost-mantle analogue of the lithosphere, the D" region. Here we present evidence from shear-wave splitting measurements for mid-mantle anisotropy in the vicinity of the 660-km discontinuity, the boundary between the upper and lower mantle. Deep-focus earthquakes in the Tonga–Kermadec and New Hebrides subduction zones recorded at Australian seismograph stations record some of the largest values of shear-wave splitting hitherto reported. The results suggest that, at least locally, there may exist a mid-mantle boundary layer, which could indicate the impediment of flow between the upper and lower mantle in this region
A self-consistent quantum master equation approach to molecular transport
We propose a self-consistent generalized quantum master equation (GQME) to
describe electron transport through molecular junctions. In a previous study
[M.Esposito and M.Galperin. Phys. Rev. B 79, 205303 (2009)], we derived a
time-nonlocal GQME to cure the lack of broadening effects in Redfield theory.
To do so, the free evolution used in the Born-Markov approximation to close the
Redfield equation was replaced by a standard Redfield evolution. In the present
paper, we propose a backward Redfield evolution leading to a time-local GQME
which allows for a self-consistent procedure of the GQME generator. This
approach is approximate but properly reproduces the nonequilibrium steady state
density matrix and the currents of an exactly solvable model. The approach is
less accurate for higher moments such as the noise.Comment: 9 pages, 4 figure
Differential regulation of RNA polymerase III genes during liver regeneration.
Mouse liver regeneration after partial hepatectomy involves cells in the remaining tissue synchronously entering the cell division cycle. We have used this system and H3K4me3, Pol II and Pol III profiling to characterize adaptations in Pol III transcription. Our results broadly define a class of genes close to H3K4me3 and Pol II peaks, whose Pol III occupancy is high and stable, and another class, distant from Pol II peaks, whose Pol III occupancy strongly increases after partial hepatectomy. Pol III regulation in the liver thus entails both highly expressed housekeeping genes and genes whose expression can adapt to increased demand
Attitudes towards Human Papillomavirus vaccination among African parents in a city in the north of England: A qualitative study.
Background: Human papillomavirus (HPV) is sexually transmitted and has been conclusively linked to cervical cancer and genital warts. Cervical cancer is attributed to approximately 1100 deaths annually in UK, and is the second most common female cancer globally. It has been suggested that black African women are more predisposed to HPV infection and cervical cancer. A vaccine has been developed to reduce HPV infection, and in the UK, has been offered to 12-13 year old adolescent girls through schools as part of their childhood immunization programme since 2008. Upon programme initiation, it was noted that vaccine uptake was lower in schools where girls from ethnic minority groups were proportionately higher.
Objectives: The study’s objectives were to explore factors influencing UK based African parents’ acceptance or decline of the HPV vaccine, whether fathers and mothers share similar views pertaining to vaccination and any interfamily tensions resulting from differing views.
Methodology: A qualitative study was conducted with five African couples residing in north England. Face to face semi-structured interviews were carried out. Participants were parents to at least one daughter aged between 8 and 14 years. Recruitment was done through purposive sampling using snowballing.
Results: HPV and cervical cancer awareness was generally low, with awareness lower in fathers. HPV vaccination was generally unacceptable among the participants, with fear of promiscuity, infertility and concerns that it’s still a new vaccine with yet unknown side effects cited as reasons for vaccine decline. There was HPV risk denial 3 as religion and good cultural upbringing seemed to result in low risk perceptions, with HPV and cervical cancer generally perceived as a white person’s disease. Religious values and cultural norms influenced vaccine decision-making, with fathers acting as the ultimate decision makers. Current information about why the vaccine is necessary was generally misunderstood.
Conclusion: Tailored information addressing religious and cultural concerns may improve vaccine acceptability in African parents
Dispersion of the second-order nonlinear susceptibility in ZnTe, ZnSe, and ZnS
We have measured the absolute values of the second-harmonic generation (SHG) coefficient |d| for the zinc-blende II-VI semiconductors ZnTe, ZnSe, and ZnS at room temperature. The investigated spectral region of the fundamental radiation λF ranges from 520 to 1321 nm using various pulsed laser sources. In the transparent region of the II-VI semiconductors, the SHG coefficient exceeds the values of birefringent materials as ammonium dihydrogen phosphate (ADP) and potassium dihydrogen phosphate (KDP) by one or two orders of magnitudes. Above the E0 band gap a strong dispersion of |d| is observed, showing a maximum for a second-harmonic frequency close to the E1 gap. The experimental results are compared to calculated values using a simple three-band model including spin-orbit splitting. Substantial agreement is found to the experimentally observed dispersion of the second-order nonlinear susceptibility
Diabetes-Related Autoantibodies in Children With Acute Lymphoblastic Leukemia
[No abstract available
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