In Vivo Cellular-Level 3D Imaging of Peripheral Nerves Using a Dual-Focusing Technique for Intra-Neural Interface Implantation

In vivo volumetric imaging of the microstructural changes of peripheral nerves with an inserted electrode could be key for solving the chronic implantation failure of an intra-neural interface necessary to provide amputated patients with natural motion and sensation. Thus far, no imaging devices can provide a cellular-level three-dimensional (3D) structural images of a peripheral nerve in vivo. In this study, an optical coherence tomography-based peripheral nerve imaging platform that employs a newly proposed depth of focus extension technique is reported. A point spread function with the finest transverse resolution of 1.27 µm enables the cellular-level volumetric visualization of the metal wire and microstructural changes in a rat sciatic nerve with the metal wire inserted in vivo. Further, the feasibility of applying the imaging platform to large animals for a preclinical study is confirmed through in vivo rabbit sciatic nerve imaging. It is expected that new possibilities for the successful chronic implantation of an intra-neural interface will open up by providing the 3D microstructural changes of nerves around the inserted electrode.

Identification of the effect of extracellular polymeric substances on bacterial adhesion to the membrane surface in a membrane bioreactor using Pseudomonas fluorescens

In a membrane bioreactor (MBR) process containing a variety of bacteria, the bacterial adhesion to the membrane surface, prior to cake formation, causes an increased filtration resistance. In this study, Pseudomonas fluorescens, commonly found in the municipal wastewater treatment process with activated sludge, was used to show the effects of extracellular polymeric substances (EPS) on bacterial adhesion to the membrane surface in the MBR. Of the various roles of EPS in promoting membrane fouling, the adhesion of bacteria to the membrane surface was calculated using the specific cake resistance (alpha, m/kg). Although the amount of EPS binding with bacteria was increased by the addition of Ca2+, there was no significant effect on the bacterial growth. The results of the particle size distribution showed that the addition of Ca2+ increased flocculation, allowing the formation of a complex with the bacteria and EPS. In order to identify the effects of the addition of Ca2+ on the hydrophobicity, the contact angle was also measured. The result showed that the addition of Ca2+ showed no significant differences in the hydrophobicity, even though there was an increase in flocculation. With the bacteria containing a higher EPS concentration, a higher specific cake resistance was observed. From the results of the adhesion experiment, which was conducted with various EPS levels, displayed as the COD and TOC concentration, an increased EPS concentration was shown to promote bacterial adhesion to the membrane surface.

Polymorphisms within the CTLA4 gene are associated with infant atopic dermatitis

BACKGROUND

Atopic dermatitis (AD) is one of the most common childhood disorders. It can have a significant impact on the physical and psychological well-being of affected individuals. Although environmental triggers are important, AD also has a strong genetic component. Identifying genes associated with AD may help to understand better the basis of this disorder and its relationship with other allergic disorders such as asthma.

OBJECTIVES

Polymorphisms in the gene encoding the inhibitory CTLA4 receptor, an important regulator of T cells, are associated with asthma as well as autoimmune disorders. We have now tested whether polymorphisms in the CTLA4 gene are also associated with early childhood AD.

METHODS

A family-based cohort of 112 children and their parents was recruited from Western Sydney, Australia. All children were seen by a paediatric dermatologist and presented with AD within the first 3 years of life. Using the transmission disequilibrium test, individual and haplotypic associations with the +49 and CT60 polymorphisms in exon 1 and the 3' nontranslated DNA of the CTLA4 gene were tested.

RESULTS

Single tests of association revealed significant association of the +49(A) [P = 0.037, odds ratio (OR) 1.59, 95% confidence interval (CI) 1-2.55] and borderline significance of the CT60(A) alleles (P = 0.055, OR 1.51, 95% CI 1-2.38). Significant association of the +49(A)/CT60(A) haplotype was detected (P = 0.002, OR 1.78, 95% CI 1.2-2.65).

CONCLUSIONS

Polymorphisms within the gene encoding CTLA4 were associated with early onset infant AD. This is in agreement with findings from asthmatic cohorts, suggesting that the +49(A)/CT60(A) haplotype is a genetic risk factor common to asthma and AD.

Comparison of membrane biofouling in nitrification and denitrification for the membrane bioreactor (MBR)

Batch filtration tests were conducted to compare the characteristics of membrane biofouling with regard to nitrification and denitrification. A Modified Fouling Index (MFI) was obtained using a stirred cell tester. The denitrification assays showed higher membrane fouling rates than the nitrification assays. The fouling became worse, not only due to pore blocking resistance, but also from cake layer resistance after denitrification. The Extracellular Polymeric Substances (EPS) concentration and relative hydrophobicity were decreased after denitrification, resulting in floc deterioration. The floc deterioration was assumed to have increased the cake layer resistance in the filtration test. The protein Soluble Microbial Products (SMP) concentration, portion of high molecular weight in carbohydrate SMP and relative hydrophobicity were increased after denitrification, which was assumed to cause membrane pore blocking. The changes in the EPS and SMP characteristics were the main fouling parameters in denitrification.

Polymorphisms within the PHF11 gene at chromosome 13q14 are associated with childhood atopic dermatitis

Atopic dermatitis is an increasingly common and debilitating childhood disorder that is often accompanied by asthma and allergic rhinitis. Although the pathology of these disorders is distinct, the majority of cases are atopic, typified by elevated serum IgE. A new locus at chromosome 13q14 centred on the genes SETDB2 and PHF11 and associated with increased total serum IgE has recently been identified. Although the precise functions of SETDB2 and PHF11 are not known, both proteins are expressed in cells of the immune system and include conserved domains that suggest a role in chromatin remodelling or transcriptional regulation, respectively. In a family-based association study across the SETDB2 and PHF11 genes, we have identified two single-nucleotide polymorphisms in the PHF11 gene significantly associated with childhood atopic dermatitis in an Australian cohort. These results provide further evidence that this locus is a novel and important regulator of human atopic disease.

Effect of residual ozone on membrane fouling reduction in ozone resisting microfiltration (MF) membrane system

The effect of residual ozone on reducing the membrane fouling was investigated using ozone resisting microfiltration membrane. It was found out that the fouling was reduced effectively by maintaining residual ozone in the membrane module. To clarify the reason why the residual ozone reduces the membrane fouling, research was focused on the molecular degradation reaction and particle destabilization reaction induced by residual ozone. The major reason of membrane fouling reduction was attributed to the reduction of reversible resistance induced by the cake layer. The reversible resistance was reduced due to degradation of organic substances in the cake layer. In addition to degradation reaction, the increase of fouling particle size due to residual ozone in the cake layer is another important process for fouling reduction. This effect has been referred to as ozone-induced destabilization reaction. The calcium present in the raw water influenced this reaction. The increase of fouling particles size improves the filterability through the cake layer and backwashing efficiency.