This research sought to enhance the efficiency and biocompatibility of anodes in bioelectrochemical systems (BESs) such as microbial fuel cells (MFCs), with an aim toward large-scale, real-world applications. The study focused on the effects of acid-heat treatment and chemical modification of three-dimensional porous pristine carbon felt (CF) on power generation. Different treatments were applied to the pristine CF, including coating with carbon nanofibers (CNFs) dispersed using dodecylbenzene sulfonate (SDBS) surfactant and biopolymer chitosan (CS).
View Article and Find Full Text PDFThis study introduces the utilization of self-powered microbial fuel cell (MFC)-based biosensors for the detection of biotoxicity in wastewater. Current MFC-based biosensors lack specificity in distinguishing between different pollutants. To address this limitation, a novel approach is introduced, capitalizing on the adaptive capabilities of anodic biofilms.
View Article and Find Full Text PDFBacterial degraders of chlorophenoxy herbicides have been isolated from various ecosystems, including pristine environments. Among these degraders, the sphingomonads constitute a prominent group that displays versatile xenobiotic-degradation capabilities. Four separate sequencing strategies were required to provide the complete sequence of the complex and plastic genome of the canonical chlorophenoxy herbicide-degrading Sphingobium herbicidovorans MH.
View Article and Find Full Text PDFIn estuarine ecosystems, metallic and organic contaminants are mainly associated with fine grain sediments which settle on mudflats. Over time, the layers of sediment accumulate and are then transformed by diagenetic processes mainly controlled by microbial activity, recording the history of the estuary's chemical contamination. In an environment of this specific type, we investigated the evolution of the chemical contamination and the structure of both total and active microbial communities, based on PhyloChip analysis of a 4.
View Article and Find Full Text PDFAntibiotic resistance, including multiresistance acquisition and dissemination by pathogens, is a critical healthcare issue threatening our management of infectious diseases [1-3]. Rapid accumulation of resistance phenotypes implies a reservoir of transferable antibiotic resistance gene determinants (ARGDs) selected in response to inhibition of antibiotic concentrations, as found in hospitals [1, 3-5]. Antibiotic resistance genes were found in environmental isolates, soil DNA [4-6], secluded caves [6, 7], and permafrost DNA [7, 8].
View Article and Find Full Text PDFThis study focused on the microbial ecology of tetrachloroethene (PCE) degradation to trichloroethene, cis-1,2-dichloroethene and vinyl chloride to evaluate the relationship between the microbial community and the potential accumulation or degradation of these toxic metabolites. Multiple soil microcosms supplied with different organic substrates were artificially contaminated with PCE. A thymidine analogue, bromodeoxyuridine (BrdU), was added to the microcosms and incorporated into the DNA of actively replicating cells.
View Article and Find Full Text PDFA straightforward method for the preparation of hybrid bioorganic-inorganic materials is reported. Common strategies to synthesize such promising materials require special surface modifications of silica followed by grafting of the organic moiety via chemoselective ligation. In this context, we set up a general and bottom-up strategy relying on modified peptides functionalized with a trialkoxysilane group.
View Article and Find Full Text PDFWe investigated the interactions between snowpack chemistry, mercury (Hg) contamination and microbial community structure and function in Arctic snow. Snowpack chemistry (inorganic and organic ions) including mercury (Hg) speciation was studied in samples collected during a two-month field study in a high Arctic site, Svalbard, Norway (79 °N). Shifts in microbial community structure were determined by using a 16S rRNA gene phylogenetic microarray.
View Article and Find Full Text PDFChitin is the second most produced biopolymer on Earth after cellulose. Chitin degrading enzymes are promising but untapped sources for developing novel industrial biocatalysts. Hidden amongst uncultivated micro-organisms, new bacterial enzymes can be discovered and exploited by metagenomic approaches through extensive cloning and screening.
View Article and Find Full Text PDFAppl Environ Microbiol
February 2011
Soil microbial communities contain the highest level of prokaryotic diversity of any environment, and metagenomic approaches involving the extraction of DNA from soil can improve our access to these communities. Most analyses of soil biodiversity and function assume that the DNA extracted represents the microbial community in the soil, but subsequent interpretations are limited by the DNA recovered from the soil. Unfortunately, extraction methods do not provide a uniform and unbiased subsample of metagenomic DNA, and as a consequence, accurate species distributions cannot be determined.
View Article and Find Full Text PDFThe repair of DNA double-strand breaks (DSBs) is essential to maintain genomic integrity. In higher eukaryotes, DNA DSBs are predominantly repaired by non-homologous end joining (NHEJ), but DNA ends can also be joined by an alternative error-prone mechanism termed microhomology-mediated end joining (MMEJ). In MMEJ, the repair of DNA breaks is mediated by annealing at regions of microhomology and is always associated with deletions at the break site.
View Article and Find Full Text PDFSaudi J Kidney Dis Transpl
October 2012
Viral hepatitis, especially "C" type (HCV), is an important cause of morbidity and mortality among recipients of renal transplants. In a retrospective long-term study, we reviewed 399 renal transplant patients (133F, 266M) who received 415 kidneys during the past eight-years. We evaluated their HCV infection and liver status.
View Article and Find Full Text PDFThe synthesis of a series of fully O-derivatised para-acyl-calix[8]arenes is described, where the acyl function is either octanoyl or hexadecanoyl. The groups attached at the phenolic face are, carboxymethoxy (anionic), carboxypropoxy (anionic), 4-sulfonatobutoxy (anionic), ethoxycarboxymethoxy (neutral), ethoxycarboxypropoxy (neutral), 2-methoxyethoxy (neutral) and 2-(2-methoxy)diethoxy (neutral). The use of specific synthetic routes has allowed complete substitution in high yields for all the compounds obtained.
View Article and Find Full Text PDFA calix[4]arene functionalized at one phenolic group with a pendant ethoxy acetate group, forms an inclusion complex that is stable even in the presence of other potential guest molecules.
View Article and Find Full Text PDFBackground: Arterial hypertension (HT), secondary to cyclosporine A (CsA) used as main immunosuppressive treatment in renal transplantation (RTx), is very frequent (70%), usually severe and explained mostly by vasoconstriction of the glomerular afferent arteriole with secondary sodium and water retention.
Material And Methods: In a retrospective study, we have analyzed 294 consecutive recipients receiving a first renal cadaveric allograft and all treated with CsA (the majority with triple therapy). We studied, by molecular biology, the polymorphism of genes previously implicated in essential HT such as: angiotensin-converting enzyme (ACE: II, ID and DD), angiotensinogen (AGT: MM, MT and TT), angiotensin II type 1 receptor (AT1-R: AA, AC and CC) and endothelial constitutive nitric oxide synthase (ecNOS: aa, ab and bb), and correlated the data to the prevalence and severity of post-Tx HT.
HEPATITIS G VIRUS: The hepatitis G virus is an RNA virus with a genomic organization and variability similar to the hepatitis C virus but with a much different pathogenic power which remains to be elucidated. HEPATITIS G: No cases of chronic hepatitis have been observed. Coinfections with HCV and HIV do occur but do not aggravate the prognosis.
View Article and Find Full Text PDFBackground: Infection with hepatitis B virus (HBV) or hepatitis C virus (HCV) is a well-known etiology for membranoproliferative glomerulonephritis (MPGN) with subendothelial deposits (MPGN type 1).
Material And Methods: The newly discovered hepatitis G virus (HGV) is currently under active investigation. We report the first case of de novo MPGN type 1 associated with HGV infection in a young male renal transplant recipient who manifested glomerulonephritis (GN) with proteinuria 7 years after transplant, and whose original disease was chronic obstructive pyelonephritis secondary to nephrolithiasis.
Nephrol Dial Transplant
November 1998
Introduction: The newly discovered (1995) hepatitis G virus (HGV) is an RNA virus from the Flaviviridae family with 85% genomic homology to GB virus C (GBV-C). We studied the prevalence of HGV infection among a cohort of 398 renal transplant recipients (RTR), all of whom had previously received blood transfusions, been grafted between August 1984 and December 1991, and been treated by cyclosporin A (CsA) as the main immunosuppressant.
Subjects And Methods: According to hepatitis C virus (HCV) antibody status, and after exclusion of 28 HBs antigen-positive recipients, this cohort had previously been divided into an HCV +ve subgroup (106 RTR; 62 M vs 44 F; 29 French vs 77 non-French) and an HCV -ve subgroup (264 RTR; 181 M vs 83 F, 196 French vs 68 non-French).
Nephrol Dial Transplant
February 1997
The prevalence of HCV infection is high in renal transplantation (RT) patients: 29% in our cohort of 399 RT recipients. The consequences of that infection on the liver have to be carefully assessed. Clinical chronic hepatitis was detected from ALT concentrations (> x 1.
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