Promising performance of chemically exfoliated Zr-doped MoS2 nanosheets for catalytic and antibacterial applications

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications. Such materials have also demonstrated considerable efficacy to counter effects of chemical toxicity. In this study, nanostructured molybdenum disulfide (MoS₂) was doped with various concentrations (2.5, 5, 7.5, 10 wt%) of zirconium (Zr) using a hydrothermal route in order to assess its antimicrobial and catalytic potential. Doped and control samples were characterized with various techniques. X-ray diffraction (XRD) analysis confirmed the presence of the hexagonal phase of MoS₂ and identification of various functional groups and characteristic peaks (Mo bonding) was carried out using FTIR spectra. Micrographs obtained from FESEM and HR-TEM showed a sheet-like surface morphology, while agglomeration of nanosheets was observed upon doping with nanoparticles. To seek further clarity regarding the layered features of S–Mo–S planes, the defect densities and electronic band structure of pure MoS₂ and doped MoS₂ samples were investigated through Raman analysis. Optical properties of Zr-doped MoS₂ nanosheets were assessed using a UV-vis spectrophotometer and the results indicated a red-shift, i.e., movement of peaks towards longer wavelengths, of the material. Dynamics of migration and recombination of excited electron–hole pairs were investigated using PL spectroscopy, which was also used to confirm the presence of exfoliated nanosheets. In addition, the synthetic dye degradation potential of pure and doped samples was investigated in the presence of a reducing agent (NaBH₄). It was noted that doped MoS₂ showed superior catalytic activity compared to undoped MoS₂. The nanocatalyst synthesized in this study exhibited enhanced antibacterial activity against E. coli and S. aureus at high concentrations (0.5, 1.0 mg/50 μl). The present study suggests a cost-effective and environmentally friendly material that can be used to remove toxins such as synthetic dyes and tannery pollutants from industrial wastewater.

Nanostructured materials incorporated with biological reducing agents have shown significant potential for use in bactericidal applications.     

No evidence of an association between polymorphisms in the IRAK-M gene and atopic dermatitis in a German cohort

Atopic dermatitis (AD) is a chronic inflammatory skin disease which affects up to 10–15% of the human population in industrialized countries. A complex interaction of genetic and environmental factors is suggested to be involved in the pathogenesis of this disease. Activation of the innate immune system via toll-like receptors (TLRs) might play a role in this respect.Interleukin-1 receptor associated kinase M (IRAK-M) negatively regulates TLR signalling and inflammation. Recently, the IRAK-M gene was identified to confer linkage to asthma on chromosome 12q13–24 in a Sardinian population, and variation within the IRAK-M gene was associated with early-onset persistent asthma in Sardinian and Italian cohorts. In order to evaluate the possible role of polymorphisms in the IRAK-M gene in the pathogenesis of AD, we investigated six single nucleotide polymorphisms (SNPs) in this gene in a German AD case-control study. Unrelated AD patients (n = 361) and healthy controls (n = 325) were studied genetically using PCR-coupled methods. Analysis of single SNPs and haplotypes did not reveal a significant association between polymorphisms in the IRAK-M gene and AD in this cohort.     

Evaluation of the toll-like receptor 6 Ser249Pro polymorphism in patients with asthma,atopic dermatitis and chronic obstructive pulmonary disease

Background  

For allergic disorders, the increasing prevalence over the past decade has been attributed in part to the lack of microbial burden in developed countries ('hygiene hypothesis'). Variation in genes encoding toll-like receptors (TLRs) as the receptor system for the first innate immune response to microbial stimuli has been implicated in various inflammatory diseases. We evaluated here the role of a coding variation, Ser249Pro, in the TLR6 gene in the pathogenesis of asthma, atopic dermatitis (AD) and chronic obstructive pulmonary disease (COPD).     

Variation in genes encoding eosinophil granule proteins in atopic dermatitis patients from Germany

Background  

Atopic dermatitis (AD) is believed to result from complex interactions between genetic and environmental factors. A main feature of AD as well as other allergic disorders is serum and tissue eosinophilia. Human eosinophils contain high amounts of cationic granule proteins, including eosinophil cationic protein (ECP), eosinophil-derived neurotoxin (EDN), eosinophil peroxidase (EPO) and major basic protein (MBP). Recently, variation in genes encoding eosinophil granule proteins has been suggested to play a role in the pathogenesis of allergic disorders. We therefore genotyped selected single nucleotide polymorphisms within the ECP, EDN, EPO and MBP genes in a cohort of 361 German AD patients and 325 healthy controls.     

TiO2 Co-doped with Zr and Ag shows highly efficient visible light photocatalytic behavior suitable for treatment of polluted water

The objective of this study is to analyze the effects of zirconium (Zr) and silver (Ag) doping on the photoactivity of titania (TiO₂). Zr–Ag (ZA) co-doped TiO₂ products were fabricated via sol–gel technique and their properties (structural and chemical) were characterized. The weight ratio of TiO₂ was fixed, while weight ratios of Zr and Ag were varied from 2 to 4, 6 and 8 wt% while synthesized samples were calcined at 400 °C for 3 h. The XRD results demonstrated that the incorporation of metal doping agents failed to alter the host material''s lattice structure, however, its crystallite size was reduced from 13.54 to 5.05 nm with increasing Zr⁴⁺ and Ag⁺ concentrations. FTIR spectroscopy was used to examine various functional groups. In the attained spectra, an ample absorption peak between 500 and 1000 cm⁻¹ was recorded, which was ascribed to Ti–O–Ti linkage vibration mode present within TiO₂. Surface morphology, microstructure, SAED patterns and elemental composition were examined with FE-SEM, HR-TEM and EDX, which served to confirm the ZA-doped TiO₂ product. Band gap energy of the co-doped material was significantly reduced as indicated by a higher wavelength redshift in the spectra. The photoactivity and kinetics of photo-products were investigated by observing photo-decolorization of methylene blue (MB) under a radiation source. Photodecomposition of MB was dramatically enhanced when titania co-doped with Zr and Ag was employed compared to un-doped or mono-doped TiO₂. The ZA (8 wt%) co-doped TiO₂ photocatalyst depicted the maximum MB removal efficiency (∼93%) within 90 min under a light source.

The objective of this study is to analyze the effects of zirconium (Zr) and silver (Ag) doping on the photoactivity of titania (TiO₂).     

Variation in the BDNF and NGFB genes in German atopic dermatitis patients

In humans, atopic dermatitis (AD) is believed to result from a complex interaction between genetic and environmental factors. Based on recent evidence, it has been proposed that neurotrophins play an important role in allergic inflammation. Levels of nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF) in blood have been found to be elevated and correlated positively with disease in AD patients. Therefore, we sought to evaluate the role of nucleotide variation in the NGFB and BDNF genes in relation to the pathogenesis of AD. A functional polymorphism within the BDNF gene (Val66Met) and six selected polymorphisms in the NGFB gene were examined in 361 German AD patients and 325 non-atopic controls. In this cohort, no significant association with AD was detected, refuting the hypothesis that variation in these two neurotrophin genes contributes substantially to AD.     

Implementation of the World Health Organization Trauma Care Checklist Program in 11 Centers Across Multiple Economic Strata: Effect on Care Process Measures

Background

Trauma contributes more than ten percent of the global burden of disease. Initial assessment and resuscitation of trauma patients often requires rapid diagnosis and management of multiple concurrent complex conditions, and errors are common. We investigated whether implementing a trauma care checklist would improve care for injured patients in low-, middle-, and high-income countries.

Methods

From 2010 to 2012, the impact of the World Health Organization (WHO) Trauma Care Checklist program was assessed in 11 hospitals using a stepped wedge pre- and post-intervention comparison with randomly assigned intervention start dates. Study sites represented nine countries with diverse economic and geographic contexts. Primary end points were adherence to process of care measures; secondary data on morbidity and mortality were also collected. Multilevel logistic regression models examined differences in measures pre- versus post-intervention, accounting for patient age, gender, injury severity, and center-specific variability.

Results

Data were collected on 1641 patients before and 1781 after program implementation. Patient age (mean 34 ± 18 vs. 34 ± 18), sex (21 vs. 22 % female), and the proportion of patients with injury severity scores (ISS) ≥ 25 (10 vs. 10 %) were similar before and after checklist implementation (p > 0.05). Improvement was found for 18 of 19 process measures, including greater odds of having abdominal examination (OR 3.26), chest auscultation (OR 2.68), and distal pulse examination (OR 2.33) (all p < 0.05). These changes were robust to several sensitivity analyses.

Conclusions

Implementation of the WHO Trauma Care Checklist was associated with substantial improvements in patient care process measures among a cohort of patients in diverse settings.

     

Polymorphisms in NACHT-LRR (NLR) genes in atopic dermatitis

Atopic dermatitis (AD) is a chronic skin disease affecting up to 15% of children in industrialized countries. AD belongs to the group of atopic disorders characterized by excessive immune reactions to ubiquitous antigens. Complex interactions between genetic and environmental factors have been suggested for atopic disorders. Dysregulation of the innate immune system appears crucial for the pathogenesis of AD. The NACHT-LRRs (NLRs) represent a group of innate immune receptors with special relevance for inflammatory processes. In order to investigate the role of variation in NLR genes for AD, we genotyped 23 single nucleotide polymorphisms (SNPs) in seven selected NLR genes (CARD4, CARD15, CARD12, NALP1, NALP3, NALP12, MHC2TA) in 392 AD patients and 297 controls by restriction enzyme digestion or TaqMan assays. Single-SNP analysis demonstrated significant associations of the CARD15_R702W variation and the NALP12_In9 T-allele with AD (P = 0.008 and P = 0.03, resp.; insignificant after Bonferroni correction). In the CARD4 gene, a rare haplotype was more frequent in AD patients than in controls. Interactions between all pairs of SNPs in the seven genes were analysed by logistic regression. Significant interactions comprised SNPs in the CARD4 gene (CARD4_In1 and CARD4_Ex6, P = 6.56 x 10(-7); CARD4_Prom und CARD4_Ex6, P = 2.45 x 10(-4)) and promoter polymorphisms in the CARD12 and NALP1 genes (P = 4.31 x 10(-4)). In conclusion, variation in individual genes from the NLR family as well as interactions within this group of innate immune receptor genes could play a role in AD pathogenesis. Investigations in other populations and functional studies are warranted to clarify contributions of NLR variation for this frequent skin disease.