Mechanistic Study of Glucose Photoreforming over TiO2-Based Catalysts for H2 Production

Glucose is a key intermediate in cellulose photoreforming for H₂ production. This work presents a mechanistic investigation of glucose photoreforming over TiO₂ and Pt/m-TiO₂ catalysts. Analysis of the intermediates formed in the process confirmed the α-scission mechanism of glucose oxidation forming arabinose (C_n-1 sugar) and formic acid in the initial oxidation step. The selectivity to sugar products and formic acid differed over Pt/TiO₂ and TiO₂, with Pt/TiO₂ showing the lower selectivity to formic acid due to enhanced adsorption/conversion of formic acid over Pt/TiO₂. In situ ATR-IR spectroscopy of glucose photoreforming showed the presence of molecular formic acid and formate on the surface of both catalysts at low glucose conversions, suggesting that formic acid oxidation could dominate surface reactions in glucose photoreforming. Further in situ ATR-IR of formic acid photoreforming showed Pt-TiO₂ interfacial sites to be key for formic acid oxidation as TiO₂ was unable to convert adsorbed formic acid/formate. Isotopic studies of the photoreforming of formic acid in D₂O (with different concentrations) showed that the source of the protons (to form H₂ at Pt sites) was determined by the relative surface coverage of adsorbed water and formic acid.

Wolf's Isotopic Response After Herpes Zoster Infection in Chronic Lichen Sclerosus-Like Graft versus Host Disease: Case Report and Literature Review

Wolf's isotopic response (WIR) refers to the occurrence of a new skin disease at the exact site of an unrelated skin disease that had previously healed, often subsequent to virus infection. Secondary cutaneous diseases that are frequently observed in WIR include granulomatous reactions, dysimmune reactions, malignancies, and infections. However, secondary chronic graft-versus-host disease (GVHD) is rare. We describe a patient with lichen sclerosus-like GVHD who developed lichen planus-like GVHD lesions secondary to herpes zoster infection.

Nonisomorphic and Nonisotopic Multidermatomal Discoid Lupus Erythematosus - A Rare Subtype of Cutaneous Lupus Erythematosus

Discoid lupus erythematosus (DLE) is the most common variant of chronic cutaneous lupus erythematosus. Several cases of Blaschko-linear lupus erythematosus, which is regarded as a distinct subtype of lupus erythematosus, have been reported across the globe. Dermatomal involvement in DLE is rare and that too has been reported in patients of systemic lupus erythematosus at site of healed herpes zoster either as an isomorphic or isotopic phenomenon. Here, we report a case of DLE on account of its unusual morphology, de novo multidermatomal configuration, without previous episode of herpes zoster or trauma.

Green synthesis and bactericidal activities of isotropic and anisotropic spherical gold nanoparticles produced using Peganum harmala L leaf and seed extracts

Shape, size, and homogeneity affect the biological activity of gold nanoparticles (AuNPs) in nanomedicine and catalytic applications. Here we biosynthesized monodispersed isotropic and polydispersed anisotropic spherical AuNPs from leaf and seed extract broths of the medicinal plant Peganum harmala L. (Ph. L). Synthesized AuNPs were characterized by ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy (FT-IRS), field-emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The antimicrobial activity of AuNPs against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) human pathogens was also assessed. Leaf- and seed-derived AuNPs had characteristic localized surface plasmon resonances of 530 and 578 nm, respectively. TEM, FE-SEM, EDX, and XRD revealed the formation of elemental face-centered cubic spherical monodispersed isotropic AuNPs of average size 43.44 nm and polydispersed anisotropic AuNPs of average size 52.04 nm from leaf and seed extract broths, respectively. FT-IR revealed polyphenols and alcohols as responsible for AuNP capping, reduction, and protection. Anisotropic AuNPs showed no antibacterial activity, whereas isotropic AuNPs showed good inhibition of both E. coli and S. aureus. This represents a simple and ecofriendly protocol for the green synthesis of monodispersed isotropic spherical AuNPs, which may have value in a variety of applications.

[Source of Nitrate in Surface Water and Shallow Groundwater Around Baiyangdian Lake Area Based on Hydrochemical and Stable Isotopes]

In order to study the source of nitrate in surface water and groundwater near a domestic sewage discharge river in the Baiyangdian watershed, including the Fuhe River and Baiyangdian Lake, shallow groundwater and deep groundwater samples were collected in July 2014.Water chemistry and stable isotopes (δ² H and δ¹⁸O) were used to study the relationship between the surface water and groundwater. δ¹⁵ N was used to explore the source of nitrate. The results show that urban and rural domestic sewage discharge to Fuhe River and then experience evaporation. Shallow groundwater is affected by the Fuhe River, Baiyangdian Lake, and lateral recharge from groundwater in the Taihang Mountain area. There are 16.7% of shallow groundwater samples exceeds the NO₃^- threshold for drinking water according to the World Health Organization standard. Due to the effect of self-purification capacity, the NO₃^- mass concentration in the Fuhe River is higher in the upstream area than in the downstream area. Due the regional water flow from northwest to southeast, the NO₃^- mass concentration in the shallow groundwater is higher in the south bank area than in north bank area. The shallow groundwater near the Fuhe River and Baiyangdian Lake is recharged by surface water. In addition, soil, fertilizer, and point sources are also major sources for groundwater nitrate. Urban and rural residential living and agricultural production activities are the main reasons for surface water and groundwater nitrate.

[Simulation of Nitrate Isotopic (δ15N and δ18O) by Coupling the Hydrology and Transport Processes Described by the SWAT Model]

To improve the reliability of methods to trace surface water pollutants in river basins, hydrological and water quality processes in the Fuxi River Basin were continuously monitored from 2013 to 2015, and the main pollution sources in the watershed and δ¹⁵N as well as δ¹⁸O in the rivers were measured simultaneously. The Soil and Water Assessment Tool (SWAT) model was used to simulate the NH₄⁺ and NO₃^- migration processes in the hydrological processes of the land surface and rivers. On this basis, the processes of mixing, transformation, and fractionation of δ¹⁵N and δ¹⁸O in NO₃^- were coupled, and the simulation methods of δ¹⁵N and δ¹⁸O in the rivers were developed. The results showed that δ¹⁵N and δ¹⁸O in the rivers were mainly affected by the pollution sources in the river basin and the variation in runoff conditions during different hydrological periods. The contribution of the mixing process of different isotopes to the isotope abundance was 82.74%. The contribution of isotope fractionation in the process of nitrogen conversion was 16.26%. The influence of NH₄⁺ and NO₃^- concentration deviation from the SWAT simulation on the simulation errors of δ¹⁵N and δ¹⁸O was 10.44%. The δ¹⁸O simulation errors were 18.72% larger than those of δ¹⁵N because of the higher variation range of δ¹⁸O in rainfall and the complexity of δ¹⁸O. The systematic errors and deviations of the simulated δ¹⁵N and δ¹⁸O results using the proposed method were less than 10% and 15%, respectively. The simulation method of δ¹⁵N and δ¹⁸O in the river basin has a clear physical meaning, which provides a useful approach for tracing nitrogen sources in rivers.

Zosteriform impetigo: Wolf's isotopic response in a cutaneous immunocompromised district

Background:

Impetigo can result from Staphylococcus aureus (S. aureus). Wolf’s isotopic response is the occurrence of a new cutaneous disorder at the site of a previously healed disease. A cutaneous immunocompromised district is an area of skin that is more vulnerable than the rest of the individual’s body.

Purpose:

To describe a man with impetigo localized to a unilateral dermatome and review the clinical features of other patients with zosteriform Staphylococcus aureus cutaneous infection.

Methods:

PubMed was used to search the following terms, separately and in combination: cutaneous, dermatome, dermatomal, district, herpes, immunocompromised, impetigo, infection, isotopic, response, skin, staphylococcal, Staphylococcus aureus, Wolf, zoster, zosteriform. All papers were reviewed and relevant manuscripts, along with their reference citations, were evaluated.

Results:

Crusted, eroded and intact, erythematous papules and nodules acutely presented localized to the mandibular branch of the left trigeminal nerve on the face of a 66-year-old man; he did not recall a prior episode of varicella-zoster virus infection in that area. A bacterial culture isolated methicillin-susceptible S. aureus. Viral cultures and direct fluorescent absorption studies were negative for herpes simplex and herpes zoster virus. All of the lesions resolved after oral treatment with cefdinir. Impetigo and/or furunculosis in a zosteriform distribution have also been described in 3 additional patients. The bacterial culture showed either methicillin-susceptible or methicillin-resistant S. aureus; the skin infection resolved after treatment with oral antibiotics; however one man experienced 2 recurrences in the same area.

Conclusions:

Zosteriform cutaneous staphylococcal impetigo may be an example of Wolf’s isotopic response in a cutaneous immunocompromised district