Probing interlayer interactions between graphene and metal substrates by supersonic rare-gas atom scattering

We demonstrate that highly surface-sensitive supersonic rare-gas (He, Ar, and Xe) atom scattering, in both the quantum and classical regimes, can probe and quantify the interlayer interactions between graphene monolayers and metal substrates in terms of the Debye temperature corresponding to the surface normal vibration, and the surface effective mass. As models of the strongly and weakly interacting graphene, we investigated two systems, graphene on Ru(0001) and Pt(111), respectively. The experimental data for Ar and Xe are compared with the results from theoretical simulations based on the classical smooth surface model. For gr/Pt(111) we find that the scattering pattern of the rare-gas beam, including the Debye-Waller attenuation of the He beam, are quite similar to that from highly oriented pyrolytic graphite (HOPG); this suggests that the graphene-Pt(111) interaction is much like a van der Waals interaction. On the contrary, for the gr/Ru(0001) system, we find a smaller Debye-Waller attenuation and a larger surface effective mass, indicating that graphene on Ru(0001) is tightly bonded to the substrate. Furthermore, asymmetrical spectral shapes in the Ar and Xe scattering spectra from gr/Ru(0001) are interpreted as a result of the lateral distribution of the interlayer interaction corresponding to the moiré pattern. It is found that the “valley” region of the moiré pattern has high effective mass reflecting stronger bonding to the substrate, contributing to the high reflectivity of the He beam reported for this system. On the other hand, the effective mass of the “hill” region is found to be similar to that of HOPG, indicating that this region is well decoupled from the substrate. These results demonstrate a unique capability of atom scattering to probe and evaluate the molecule-substrate interaction and its spatial distributions

Lower Expression of TLR2 and SOCS-3 Is Associated with Schistosoma haematobium Infection and with Lower Risk for Allergic Reactivity in Children Living in a Rural Area in Ghana

Inflammatory diseases such as atopic disorders are a major health problem in the Western world, but their prevalence is also increasing in developing countries, especially in urban centres. There is increasing evidence that exposure to a rural environment with high burden of compounds derived from parasites and microorganisms is associated with protection from atopic disorders. Since urbanisation is progressing at a rapid pace, particularly in less-developed nations, there is a need to understand the molecular processes that control the progress towards the development of allergic diseases in developing countries. In this study we have examined a population of school children living in a rural area of Ghana, where helminth (worm) infections are prevalent and associated with protection from skin reactivity to house dust mite. Blood samples were collected from these children and analysed for the expression levels of several genes involved in the development of a pro allergic immune system. The results point at a potential molecular link that might explain the negative association between schistosome infections and allergies

Epigenetic Modification of TLRs in Leukocytes Is Associated with Increased Susceptibility to Salmonella enteritidis in Chickens

Toll-like receptors (TLRs) signaling pathways are the first lines in defense against Salmonella enteritidis (S. enteritidis) infection but the molecular mechanism underlying susceptibility to S. enteritidis infection in chicken remains unclear. SPF chickens injected with S. enteritidis were partitioned into two groups, one consisted of those from Salmonella-susceptible chickens (died within 5 d after injection, n = 6), the other consisted of six Salmonella-resistant chickens that survived for 15 d after injection. The present study shows that the bacterial load in susceptible chickens was significantly higher than that in resistant chickens and TLR4, TLR2-1 and TLR21 expression was strongly diminished in the leukocytes of susceptible chickens compared with those of resistant chickens. The induction of expression of pro-inflammatory cytokine genes, IL-6 and IFN-β, was greatly enhanced in the resistant but not in susceptible chickens. Contrasting with the reduced expression of TLR genes, those of the zinc finger protein 493 (ZNF493) gene and Toll-interacting protein (TOLLIP) gene were enhanced in the susceptible chickens. Finally, the expression of TLR4 in peripheral blood mononuclear cells (PBMCs) infected in vitro with S. enteritidis increased significantly as a result of treatment with 5-Aza-2-deoxycytidine (5-Aza-dc) while either 5-Aza-dc or trichostatin A was effective in up-regulating the expression of TLR21 and TLR2-1. DNA methylation, in the predicted promoter region of TLR4 and TLR21 genes, and an exonic CpG island of the TLR2-1 gene was significantly higher in the susceptible chickens than in resistant chickens. Taken together, the results demonstrate that ZNF493-related epigenetic modification in leukocytes probably accounts for increased susceptibility to S. enteritidis in chickens by diminishing the expression and response of TLR4, TLR21 and TLR2-1

Analysis of the human monocyte-derived macrophage transcriptome and response to lipopolysaccharide provides new insights into genetic aetiology of inflammatory bowel disease

The FANTOM5 consortium utilised cap analysis of gene expression (CAGE) to provide an unprecedented insight into transcriptional regulation in human cells and tissues. In the current study, we have used CAGE-based transcriptional profiling on an extended dense time course of the response of human monocyte-derived macrophages grown in macrophage colony-stimulating factor (CSF1) to bacterial lipopolysaccharide (LPS). We propose that this system provides a model for the differentiation and adaptation of monocytes entering the intestinal lamina propria. The response to LPS is shown to be a cascade of successive waves of transient gene expression extending over at least 48 hours, with hundreds of positive and negative regulatory loops. Promoter analysis using motif activity response analysis (MARA) identified some of the transcription factors likely to be responsible for the temporal profile of transcriptional activation. Each LPS-inducible locus was associated with multiple inducible enhancers, and in each case, transient eRNA transcription at multiple sites detected by CAGE preceded the appearance of promoter-associated transcripts. LPS-inducible long non-coding RNAs were commonly associated with clusters of inducible enhancers. We used these data to re-examine the hundreds of loci associated with susceptibility to inflammatory bowel disease (IBD) in genome-wide association studies. Loci associated with IBD were strongly and specifically (relative to rheumatoid arthritis and unrelated traits) enriched for promoters that were regulated in monocyte differentiation or activation. Amongst previously-identified IBD susceptibility loci, the vast majority contained at least one promoter that was regulated in CSF1-dependent monocyte-macrophage transitions and/or in response to LPS. On this basis, we concluded that IBD loci are strongly-enriched for monocyte-specific genes, and identified at least 134 additional candidate genes associated with IBD susceptibility from reanalysis of published GWA studies. We propose that dysregulation of monocyte adaptation to the environment of the gastrointestinal mucosa is the key process leading to inflammatory bowel disease

Vesicovaginal/rectovaginal fistula formation and outcome of Stage IVA carcinoma of the cervix treated with radiotherapy

Purpose: To review the morbidity and mortality of Stage IVA cervical cancer, with a particular focus on the incidence of fistulae. Materials and Methods: The authors retrospectively analyzed 30 patients with Stage IVA cervical cancer, treated with whole pelvic-external beam radiotherapy (WP-EBRT) and high-dose-rate intracavitary brachytherapy (HDR-ICBT). Results: Seven patients presented with vesicovaginal fistula at the time of cancer diagnosis and six developed a fistula during or after radiotherapy (RT). Fistula was diagnosed 0-41 months after cancer diagnosis. The patients with fistulae had a median survival of 32 months. Six patients are alive, four of whom have no evidence of recurrence, while two have persistent disease. The five-year overall survival (OS) was 14.9% in the patients with fistula and was 39.4% in the total series. On multivariate analysis, RT without HDR-ICBT was an independent prognostic factor. Conclusion: High rates of vesicovaginal fistulae were observed in Stage IVA cervical cancer. Interventions for vesicovaginal fistula to improve quality of life are very important