Outgassing Losses of Toluene and m-Xylene Evaluated by 14C-Based Mass Balances for Laboratory Bioventing Simulations

Mixtures of toluene, ethylbenzene, and the xylenes spiked with ¹⁴C-labeled toluene or m-xylene were added to bench-scale bioventing simulation columns filled with hydrocarbon-contaminated subsurface soils. After 2 to 4 weeks of incubation during which air was pumped through the column at rates of at least 2?ml·min^?1·kg^?1 between 54 and 84% of the radiolabel was recovered in traps as outgassed parent compound from four columns sterilized with gamma-irradiation. In contrast, seven nonsterilized but otherwise identically treated (except for inorganic nitrogen addition) columns lost less than 0.4% (and one column lost 0.7%) of the radiolabel through outgassing of the parent compound. Nonsterilized columns lost 40 to 61% of the radiolabel as ¹⁴CO₂, whereas gamma-irradiated columns usually lost only trace amounts of ¹⁴C in this form. Biologically active columns also retained much larger fractions than sterilized columns of the radiolabel in the subsoil in forms, possibly microbial biomass, from which it could be recovered by wet oxidation. Addition of 10 or 40?mg/kg of mineral nitrogen had no consistent effect on bioventing performance.     

Mortality incidence estimation using federal death certificate and natality data with an application to Tay–Sachs disease

For confidentiality reasons, US federal death certificate data are incomplete with regards to the dates of birth and death for the decedents, making calculation of total lifetime of a decedent impossible and thus estimation of mortality incidence difficult. This paper proposes the use of natality data and an imputation‐based method to estimate age‐specific mortality incidence rates in the face of this missing information. By utilizing previously determined probabilities of birth, a birth date and death date are imputed for every decedent in the dataset. Thus, the birth cohort of each individual is imputed, and the total on‐study time can be calculated. This idea is implemented in two approaches for estimation of mortality incidence rates. The first is an extension of a person‐time approach, while the second is an extension of a life table approach. Monte Carlo simulations showed that both approaches perform well in comparison to the ideal complete data methods, but that the person‐time method is preferred. An application to Tay–Sachs disease is demonstrated. It is concluded that the imputation methods proposed provide valid estimates of the incidence of death from death certificate data without the need for additional assumptions under which usual mortality rates provide valid estimates.     

High-Performance Dye-Sensitized Solar Cells Based on Morphology-Controllable Synthesis of ZnO–ZnS Heterostructure Nanocone Photoanodes

High-density and well-aligned ZnO–ZnS core–shell nanocone arrays were synthesized on fluorine-doped tin oxide glass substrate using a facile and cost-effective two-step approach. In this synthetic process, the ZnO nanocones act as the template and provide Zn²⁺ ions for the ZnS shell formation. The photoluminescence spectrum indicates remarkably enhanced luminescence intensity and a small redshift in the UV region, which can be associated with the strain caused by the lattice mismatch between ZnO and ZnS. The obtained diffuse reflectance spectra show that the nanocone-based heterostructure reduces the light reflection in a broad spectral range and is much more effective than the bare ZnO nanocone and nanorod structures. Dye-sensitized solar cells based on the heterostructure ZnO–ZnS nanocones are assembled, and high conversion efficiency (η) of approximately 4.07% is obtained. The η improvement can be attributed primarily to the morphology effect of ZnO nanocones on light-trapping and effectively passivating the interface surface recombination sites of ZnO nanocones by coating with a ZnS shell layer.     

Complement Activation in Patients with Focal Segmental Glomerulosclerosis

Background

Recent pre-clinical studies have shown that complement activation contributes to glomerular and tubular injury in experimental FSGS. Although complement proteins are detected in the glomeruli of some patients with FSGS, it is not known whether this is due to complement activation or whether the proteins are simply trapped in sclerotic glomeruli. We measured complement activation fragments in the plasma and urine of patients with primary FSGS to determine whether complement activation is part of the disease process.

Study Design

Plasma and urine samples from patients with biopsy-proven FSGS who participated in the FSGS Clinical Trial were analyzed.

Setting and Participants

We identified 19 patients for whom samples were available from weeks 0, 26, 52 and 78. The results for these FSGS patients were compared to results in samples from 10 healthy controls, 10 patients with chronic kidney disease (CKD), 20 patients with vasculitis, and 23 patients with lupus nephritis.

Outcomes

Longitudinal control of proteinuria and estimated glomerular filtration rate (eGFR).

Measurements

Levels of the complement fragments Ba, Bb, C4a, and sC5b-9 in plasma and urine.

Results

Plasma and urine Ba, C4a, sC5b-9 were significantly higher in FSGS patients at the time of diagnosis than in the control groups. Plasma Ba levels inversely correlated with the eGFR at the time of diagnosis and at the end of the study. Plasma and urine Ba levels at the end of the study positively correlated with the level of proteinuria, the primary outcome of the study.

Limitations

Limited number of patients with samples from all time-points.

Conclusions

The complement system is activated in patients with primary FSGS, and elevated levels of plasma Ba correlate with more severe disease. Measurement of complement fragments may identify a subset of patients in whom the complement system is activated. Further investigations are needed to confirm our findings and to determine the prognostic significance of complement activation in patients with FSGS.     

Detection of Hepatitis E Virus Antibodies in Dogs in the United Kingdom

Hepatitis E virus (HEV) genotypes 3 and 4 are zoonotic pathogens, with pigs predominantly implicated in disease transmission. The rapid rise in human cases in developed countries over the past decade indicates a change in epidemiology of HEV, and it has been suggested that additional animal species may be involved in transmission of infection. Multiple studies have identified contact with dogs as a risk factor for HEV infection in industrialised nations, and a low seroprevalence to HEV has previously been reported in dogs in low-income countries. In this study we aimed to evaluate the possibility that dogs are susceptible to HEV, and determine the frequency with which this occurs. Serum samples from UK dogs with and without hepatitis were screened for HEV-specific antibodies, and canine liver and stool samples were analysed by qPCR for the presence of HEV RNA. We describe evidence to show HEV infection occurs at low levels in dogs in the UK, but the strain of origin is undetermined. The low seroprevalence level of HEV in dogs implies the risk of zoonotic disease transmission is likely to be limited, but further investigations will be required to determine if HEV-infected dogs can transmit HEV to man.     

Phylogeographical patterns in Coenosia attenuata (Diptera: Muscidae): a widespread predator of insect species associated with greenhouse crops

The tiger‐fly Coenosia attenuata is a globally widespread predatory fly which is not only associated with greenhouse crops, but also occurs in open fields. It is a potential control agent against some of the more common pests in these crops. Assessing the genetic structure and gene flow patterns may be important for planning crop protection strategies and for understanding the historical processes that led to the present distribution of genetic lineages within this species. In the present study, the phylogeographical patterns of this species, based on mitochondrial cytochrome oxidase I and nuclear white and elongation factor‐1α genes, are described, revealing relatively low genetic diversity and weak genetic structure associated with a recent and sudden population expansion of the species. The geographical distribution of mitochondrial haplotypes indicates the Mediterranean as the most likely region of origin of the species. Some dispersal patterns of the species are also revaled, including at least three independent colonizations of North and South America: one from Middle East to North America with a strong bottleneck event, another from Europe to South America (Chile), with both likely to be a result of unintentional introduction, and a third one of still undetermined origin to South America (Ecuador). © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114 , 308–326.     

Measurement of opsonophagocytic activity of antibodies specific toNeisseria meningitidis serogroup A capsular polysaccharide-serogroup B outer membrane vesicle conjugate in animal model

Neisseria meningitidis is efficiently phagocytosed by polymorphonuclear leukocytes (PMNS) following opsonization with opsonic antibodies; opsonophagocytosis is the primary mechanism for clearance of meningococci from the host. Thus, in testing meningococcal vaccines, the level of opsonophagocytic antibodies appears to correlate with vaccine-induced protection. Our previous studies demonstrated that the conjugation ofN. meningitidis serogroup A capsular polysaccharide (CPSA) to serogroup B outer membrane vesicle (OMV) could induce a high level of bactericidal antibody response against serogroup A meningococci in animals. The purpose of this study was to evaluate opsonophagocytic activity of the conjugate of CPSA to OMV (CPSA-OMV). In order to evaluate the potential efficacy of CPSA-OMV a flow cytometric opsonophagocytic assay was used. The conjugate and controls were injected intramuscularly into four groups of rabbits with boosters on days 14, 28 and 42 following primary immunization. The rabbits were bled prior to injection and two weeks after each injection. Opsonophagocytic activity of antibodies in hyperimmune sera through rabbit PMNS were measured with flow cytometer, using dihydrorhodamine-123 as a probe. The results indicated that our conjugate could induce a highly significant level of opsonophagocytic activity against serogroup A meningococci after 56 days compared to the control groups (P<0.05). We conclude that this conjugate represents a vaccine candidate against serogroups A and B meningococci after further investigation.     

Inhibitory effects of flavonoids on aldehyde oxidase activity

Flavonoids are an important group of natural compounds that can interfere with the activity of some enzymes. In this study, effects of various flavonoids on aldehyde oxidase (AO) activity were evaluated in vitro. AO was partially purified from guinea pig liver. The effects of 12 flavonoids from three subclasses of flavon-3-ol, flavan-3-ol and flavanone on the oxidation of vanillin and phenanthridine as substrates of AO and xanthine as a substrate of xanthine oxidase (XO) were investigated spectrophotometrically. Among the 12 flavonoids, myricetin and quercetin were the most potent inhibitors of both AO and XO. In general, the oxidation of vanillin was more inhibited by flavonoids than that of phenanthridine. Almost all of the flavonoids inhibited AO activity more potently than XO, which was more evident with non-planner flavanols. A planner structure seems to be essential for a potent inhibitory effect and any substitution by sugar moieties reduces the inhibitory effects. This study could provide a new insight into AO natural inhibitors with potential to lead to some food-drug interactions.