2,142 research outputs found
Characterization of Shewanella oneidensis MtrC: a cell-surface decaheme cytochrome involved in respiratory electron transport to extracellular electron acceptors
MtrC is a decaheme c-type cytochrome associated with the outer cell membrane of Fe(III)-respiring species of the Shewanella genus. It is proposed to play a role in anaerobic respiration by mediating electron transfer to extracellular mineral oxides that can serve as terminal electron acceptors. The present work presents the first spectropotentiometric and voltammetric characterization of MtrC, using protein purified from Shewanella oneidensis MR-1. Potentiometric titrations, monitored by UV–vis absorption and electron paramagnetic resonance (EPR) spectroscopy, reveal that the hemes within MtrC titrate over a broad potential range spanning between approximately +100 and approximately -500 mV (vs. the standard hydrogen electrode). Across this potential window the UV–vis absorption spectra are characteristic of low-spin c-type hemes and the EPR spectra reveal broad, complex features that suggest the presence of magnetically spin-coupled low-spin c-hemes. Non-catalytic protein film voltammetry of MtrC demonstrates reversible electrochemistry over a potential window similar to that disclosed spectroscopically. The voltammetry also allows definition of kinetic properties of MtrC in direct electron exchange with a solid electrode surface and during reduction of a model Fe(III) substrate. Taken together, the data provide quantitative information on the potential domain in which MtrC can operate
Innovative development of the inspired sinewave device to measure lung functions and inhomogeneity for diagnosis and evaluations of early lung diseases
Surprisingly, lung disease is still one of the leading causes of deaths in the developed countries, including UK.  According to the UK National Health Service (NHS), Chronic Obstructive Pulmonary Disease (COPD) is the fifth biggest killer disease in the UK, killing approximately 25,000 people a year. This prob-lem is even worse in developing countries such as Vietnam, India and China, where air pollution is a big problem and the disease awareness is under-recognised. The NHS has set out one of its challenges is to identify people with lung disease earlier in the disease’s development pathway, in order to pro-vide more effective and timely intervention and treatment. This paper presents a novel Inspired Sinewave Device (ISD) to measure lung function and inhomogeneity. Both set of infor-mation are important for diagnosis and detection of early lung diseases. ISD has the potential to replace or supplement the traditional spirometry in the routine lung function testing. The paper describes both the principle of ISD and a set of experi-mental results demonstrating the capability of ISD to asymp-totically detect asthmatic symptoms. Finally the paper discuss-es the future plan, including the testing of 300+ COPD patients at the Oxford Respiratory Trials Unit in UK, and the potential collaborations among research institutions in Vietnam and UK about cost-effective and innovative developments of smart devices, biosensors, lab-on-chips and telehealth solutions for the routine lung function testing, diagnosis and evaluations of early lung diseases
Superpulsed low-level laser therapy protects skeletal muscle of mdx mice against damage, inflammation and morphological changes delaying dystrophy progression.
Aim: To evaluate the effects of preventive treatment with low-level laser therapy (LLLT) on progression of dystrophy in mdx mice. Methods: Ten animals were randomly divided into 2 experimental groups treated with superpulsed LLLT (904 nm, 15 mW, 700 Hz, 1 J) or placebo-LLLT at one point overlying the tibialis anterior muscle (bilaterally) 5 times per week for 14 weeks (from 6th to 20th week of age). Morphological changes, creatine kinase (CK) activity and mRNA gene expression were assessed in animals at 20th week of age. Results: Animals treated with LLLT showed very few morphological changes in skeletal muscle, with less atrophy and fibrosis than animals treated with placebo-LLLT. CK was significantly lower (p = 0.0203) in animals treated with LLLT (864.70 U.l−1, SEM 226.10) than placebo (1708.00 U.l−1, SEM 184.60). mRNA gene expression of inflammatory markers was significantly decreased by treatment with LLLT (p<0.05): TNF-α (placebo-control = 0.51 µg/µl [SEM 0.12], - LLLT = 0.048 µg/µl [SEM 0.01]), IL-1β (placebo-control = 2.292 µg/µl [SEM 0.74], - LLLT = 0.12 µg/µl [SEM 0.03]), IL-6 (placebo-control = 3.946 µg/µl [SEM 0.98], - LLLT = 0.854 µg/µl [SEM 0.33]), IL-10 (placebo-control = 1.116 µg/µl [SEM 0.22], - LLLT = 0.352 µg/µl [SEM 0.15]), and COX-2 (placebo-control = 4.984 µg/µl [SEM 1.18], LLLT = 1.470 µg/µl [SEM 0.73]). Conclusion: Irradiation of superpulsed LLLT on successive days five times per week for 14 weeks decreased morphological changes, skeletal muscle damage and inflammation in mdx mice. This indicates that LLLT has potential to decrease progression of Duchenne muscular dystrophy
Mitochondrial-dependent apoptosis in Huntington's disease human cybrids
We investigated the involvement of mitochondrial-dependent apoptosis in Huntington's disease (HD) vs. control (CTR) cybrids, obtained from the fusion of human platelets with mitochondrial DNA-depleted NT2 cells, and further exposed to 3-nitropropionic acid (3-NP) or staurosporine (STS). Untreated HD cybrids did not exhibit significant modifications in the activity of mitochondrial respiratory chain complexes I-IV or in mtDNA sequence variations suggestive of a primary role in mitochondrial susceptibility in the subpopulation of HD carriers studied. However, a slight decrease in mitochondrial membrane potential and increased formation of intracellular hydroperoxides was observed in HD cybrids under basal conditions. Furthermore, apoptotic nuclei morphology and a moderate increase in caspase-3 activation, as well as increased levels of superoxide ions and hydroperoxides were observed in HD cybrids upon 3-NP or STS treatment. 3-NP-evoked apoptosis in HD cybrids involved cytochrome c and AIF release from mitochondria, which was associated with mitochondrial Bax translocation. CTR cybrids subjected to 3-NP showed increased mitochondrial Bax and Bim levels and the release of AIF, but not cytochrome c, suggesting a different mode of cell death, linked to the loss of membrane integrity. Additionally, increased mitochondrial Bim and Bak levels, and a slight release of cytochrome c in untreated HD cybrids may help to explain their moderate susceptibility to mitochondrial-dependent apoptosi
Mapping Patent Classifications: Portfolio and Statistical Analysis, and the Comparison of Strengths and Weaknesses
The Cooperative Patent Classifications (CPC) jointly developed by the
European and US Patent Offices provide a new basis for mapping and portfolio
analysis. This update provides an occasion for rethinking the parameter
choices. The new maps are significantly different from previous ones, although
this may not always be obvious on visual inspection. Since these maps are
statistical constructs based on index terms, their quality--as different from
utility--can only be controlled discursively. We provide nested maps online and
a routine for portfolio overlays and further statistical analysis. We add a new
tool for "difference maps" which is illustrated by comparing the portfolios of
patents granted to Novartis and MSD in 2016.Comment: Scientometrics 112(3) (2017) 1573-1591;
  http://link.springer.com/article/10.1007/s11192-017-2449-
The plant pathogen Pseudomonas syringae pv. tomato is genetically monomorphic and under strong selection to evade tomato immunity
addresses: Department of Plant Pathology, Physiology, and Weed Science, Virginia Tech, Blacksburg, Virginia, United States of America.notes: PMCID: PMC3161960types: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.Recently, genome sequencing of many isolates of genetically monomorphic bacterial human pathogens has given new insights into pathogen microevolution and phylogeography. Here, we report a genome-based micro-evolutionary study of a bacterial plant pathogen, Pseudomonas syringae pv. tomato. Only 267 mutations were identified between five sequenced isolates in 3,543,009 nt of analyzed genome sequence, which suggests a recent evolutionary origin of this pathogen. Further analysis with genome-derived markers of 89 world-wide isolates showed that several genotypes exist in North America and in Europe indicating frequent pathogen movement between these world regions. Genome-derived markers and molecular analyses of key pathogen loci important for virulence and motility both suggest ongoing adaptation to the tomato host. A mutational hotspot was found in the type III-secreted effector gene hopM1. These mutations abolish the cell death triggering activity of the full-length protein indicating strong selection for loss of function of this effector, which was previously considered a virulence factor. Two non-synonymous mutations in the flagellin-encoding gene fliC allowed identifying a new microbe associated molecular pattern (MAMP) in a region distinct from the known MAMP flg22. Interestingly, the ancestral allele of this MAMP induces a stronger tomato immune response than the derived alleles. The ancestral allele has largely disappeared from today's Pto populations suggesting that flagellin-triggered immunity limits pathogen fitness even in highly virulent pathogens. An additional non-synonymous mutation was identified in flg22 in South American isolates. Therefore, MAMPs are more variable than expected differing even between otherwise almost identical isolates of the same pathogen strain
Probing ultrafast carrier dynamics and nonlinear absorption and refraction in core-shell silicon nanowires
We investigate the relaxation dynamics of photogenerated carriers in silicon
nanowires consisting of a crystalline core and a surrounding amorphous shell,
using femtosecond time-resolved differential reflectivity and transmission
spectroscopy at photon energies of 3.15 eV and 1.57 eV. The complex behavior of
the differential transmission and reflectivity transients is the mixed
contributions from the crystalline core and the amorphous silicon on the
nanowire surface and the substrate where competing effects of state filling and
photoinduced absorption govern the carrier dynamics. Faster relaxation rates
are observed on increasing the photo-generated carrier density. Independent
experimental results on crystalline silicon-on-sapphire help us in separating
the contributions from the carrier dynamics in crystalline core and the
amorphous regions in the nanowire samples. Further, single beam z-scan
nonlinear transmission experiments at 1.57 eV in both open and close aperture
configurations yield two-photon absorption coefficient \ (~3 cm/GW) and
nonlinear refraction coefficient \ (-2.5x10^-4 cm2/GW).Comment: 6 pages, 6 figure
Anesthesia of Epinephelus marginatus with essential oil of Aloysia polystachya: an approach on blood parameters
This study investigated the anesthetic potential of the essential oil (EO) of Aloysia polystachya in juveniles of dusky grouper (Epinephelus marginatus). Fish were exposed to different concentrations of EO of A. polystachya to evaluate time of induction and recovery from anesthesia. In the second experiment, fish were divided into four groups: control, ethanol and 50 or 300 mu L L-1 EO of A. polystachya, and each group was submitted to induction for 3.5 min and recovery for 5 or 10 min. The blood gases and glucose levels showed alterations as a function of the recovery times, but Na+ and K+ levels did not show any alteration. In conclusion, the EO from leaves of A. polystachya is an effective anesthetic for dusky grouper, because anesthesia was reached within the recommended time at EO concentrations of 300 and 400 mu L L-1. However, most evaluated blood parameters showed compensatory responses due to EO exposure.Fundacao de Amparo a Pesquisa do Estado do Rio Grande do Sul/Programa de Apoio a Nucleos de Excelencia (FAPERGS/PRONEX) [10/0016-8]; Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [470964/2009-0]; Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior, Brazil (CAPES)info:eu-repo/semantics/publishedVersio
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