Effect of VIPS fabrication parameters on the removal of acetic acid by supported liquid membrane using a PES–graphene membrane support

In this study, the removal of acetic acid by supported liquid membrane (SLM) using hybrid polyethersulfone (PES)–graphene membrane prepared by vapor induced phase separation (VIPS) was investigated. The effects of graphene loading, coagulation bath temperature, air exposure time, and air humidity on the morphology, mechanical strength, porosity, and contact angle of the membrane were analyzed. The performance and stability of the hybrid membrane as a SLM support for acetic acid removal were studied. The best PES–graphene membrane support was produced at a coagulation bath temperature of 50 °C, an air exposure time of 30 s and air humidity of 80%. The fabricated membrane has a symmetrical micropore cellular structure, high porosity and high contact angle. Under specific SLM conditions, almost 95% of acetic acid was successfully removed from 10 g L⁻¹ aqueous acetic acid solution. The hybrid membrane remains stable for more than 116 h without suffering any membrane breakage during the continuous SLM process.

In this study, the removal of acetic acid by supported liquid membrane (SLM) using hybrid polyethersulfone (PES)–graphene membrane prepared by vapor induced phase separation (VIPS) was investigated.     

Management of infant diarrhea with high-lactose probiotic-containing formula

To study the influence of high-lactose probiotic-containing formula on the course of acute diarrhea, an experiment using a randomized controlled clinical trial with patients having acute diarrhea for 3 days was conducted. One hundred patients were allocated into two groups that were comparable for age, sex, and nutritional status. The test group was administered high-lactose Bifidobacterium bifidum-containing formula, while the control group had no high-lactose probiotic until the end of the experiment. The degree of subsequent diarrhea and recovery were monitored in both groups. The results for the test and control groups were analyzed and compared using the chi-square test and Fisher exact test with a significance level (alpha) of 0.05. The study results revealed that there was no significant difference between the test and control groups (p>0.05) as well as at positive clinical test (13%) and positive floating test (65%). However, the patients receiving probiotic-containing formula had significantly less frequency of stools, when compared with the control group (p<0.05).     

Non homologous end joining-mediated DNA break repair is impaired in B lymphocytes of aging mice

Aging is an irreversible physiological process characterized by increased risk of diseases, reduced effectiveness of vaccines, and decreased immune responses. One of the most prominent paradigms of aging and age related conditions is the progressive accumulation of un-repaired DNA breaks leading to apoptosis and exhaustion of stem cells. Here we hypothesized that B lymphocytes from old mice have reduced DNA repair mechanisms as a contributing factor for DNA break accumulation. We analyzed class switch recombination (CSR) of naïve B lymphocytes from old and adult mice to delineate the DNA double strand repair mechanisms during aging. In vitro CSR assays and DNA break analysis by labeling phosphorylated histone H2AX showed that old mice had significantly reduced DNA repair efficiency following DNA breaks. Functional efficiency analysis of DNA break repairs using plasmid ligation method showed that B lymphocytes from old mice had poor repair efficiency and increased misrepair of linear plasmid. Diminished DNA repair in old age can contribute to reduced immune cell repertoire and impaired immunity; increased occurrence of cancer; and reduced stem cell reserve.     

HLA-DO increases bacterial superantigen binding to human MHC molecules by inhibiting dissociation of class II-associated invariant chain peptides

HLA-DO (H2-O in mice) is an intracellular non-classical MHC class II molecule (MHCII). It forms a stable complex with HLA-DM (H2-M in mice) and shapes the MHC class II-associated peptide repertoire. Here, we tested the impact of HLA-DO and H2-O on the binding of superantigens (SAgs), which has been shown previously to be sensitive to the structural nature of the class II-bound peptides. We found that the binding of staphylococcal enterotoxin (SE) A and B, as well as toxic shock syndrome toxin 1 (TSST-1), was similar on the HLA-DO⁺ human B cell lines 721.45 and its HLA-DO⁻ counterpart. However, overexpressing HLA-DO in MHC class II⁺ HeLa cells (HeLa-CIITA-DO) improved binding of SEA and TSST-1. Accordingly, knocking down HLA-DO expression using specific siRNAs decreased SEA and TSST-1 binding. We tested directly the impact of the class II-associated invariant chain peptide (CLIP), which dissociation from MHC class II molecules is inhibited by overexpressed HLA-DO. Loading of synthetic CLIP on HLA-DR⁺ cells increased SEA and TSST-1 binding. Accordingly, knocking down HLA-DM had a similar effect. In mice, H2-O deficiency had no impact on SAgs binding to isolated splenocytes. Altogether, our results demonstrate that the sensitivity of SAgs to the MHCII–associated peptide has physiological basis and that the effect of HLA-DO on SEA and TSST-1 is mediated through the inhibition of CLIP release.