Exorbitant signatures of pesticides and pharmaceuticals in municipal solid wastes (MSWs): Novel insights through risk analysis, dissolution dynamics, and model-based source identification.

Studies on the occurrence and fates of emerging organic micropollutants (EOMPs) like pharmaceuticals and pesticides in MSWs are scarce in the literature. Therefore, MSWs were sampled from 20 Indian landfills and characterized for five widely consumed EOMPs (chlorpyrifos, cypermethrin, carbofuran, carbamazepine, and sodium diclofenac), physicochemical, and biological properties. The pesticide (median: 0.17-0.44 mg kg-1) and pharmaceutical (median: 0.20-0.26 mg kg-1) concentrations significantly fluctuated based on landfill localities. Eventually, principal component and multi-factor (MFA) models demonstrated close interactions of EOMPs with biological (microbial biomass and humification rates) and chemical (N, P, K, Ca, S, etc.) properties of MSWs. At the same time, the MFA resolved that EOMPs' fates in MSWs significantly differ from bigger cosmopolitan cities to smaller rural townships. Correspondingly, the concentration-driven ecological risks were high in 15 MSWs with EOMP-toxicity ranks of diclofenac > carbofuran = chlorpyrifos > cypermethrin > carbamazepine. The EOMPs' dissolution dynamics and source apportionments were evaluated using the positive matrix factorization (PMF) model for the first time on experimental data, extracting four anthropogenic sources (households, heterogeneous business centers, agricultural, and open drains). The most significant contribution of EOMPs to MSWs was due to heterogeneous business activity. Notably, the aging of soluble chemical fractions seems to influence the source characteristics of EOMPs strongly.

Characterization of Polycyclic Aromatic Hydrocarbons (PAHs) associated with fine aerosols in ambient atmosphere of high-altitude urban environment in Sikkim Himalaya.

Polycyclic Aromatic Hydrocarbons (PAHs) compounds are ubiquitous in ambient air due to their persistence, carcinogenicity, and mutagenicity. Gangtok being one of the cleanest cities in India located in Eastern Himalayan region, witnesses high developmental activities with enhanced urbanization affecting the ambient air quality. The present study aims to measure PM2.5 and PAHs in the ambient atmosphere of the Sikkim Himalaya to understand the influence of natural and anthropogenic activities on aerosol loading and their chemical characteristics. The PM2.5 samples were collected and analysed for the duration from Jan 2020 to Feb 2021.The seasonal mean concentrations of PM2.5 and PAHs were observed to be high during autumn and low during summer season. Overall, the annual mean concentration of PM2.5 was found higher than the prescribed limit of World Health Organization and National Ambient Air Quality Standards. The concentration of the 16 individual PAHs were found to be highest during autumn season (55.26 ± 37.15 ng/m3). Among the different PAHs, the annual mean concentration of fluorene (3.29 ± 4.07 ng/m3) and naphthalene (1.15 ± 3.76 ng/m3) were found to be the highest and lowest, respectively. The Molecular Diagnostic Ratio (MDR) test reveals higher contribution from heavy traffic activities throughout the winter and autumn seasons. The other possible sources identified over the region are fossil fuel combustion, and biomass burning. The multivariate statistical analysis (Multifactor Principal Component Analysis) also indicates a strong association between PM2.5 /PAHs and meteorological variables across the region in different seasons. The precipitation and wind pattern during the study period suggests that major contribution of the PM2.5 and PAHs were from local sources, with minimal contribution from long-range transport. The findings are important for comprehending the trends of PAH accumulation over a high-altitude urban area, and for developing sustainable air quality control methods in the Himalayan region.

Rapidly Evolving Large Rhinolith: Cause of Recurrent Nasal Bleed.

Rhinoliths are a rare cause of nasal obstruction but may also present with other symptoms including nasal bleed. We report a case of a rapidly evolving rhinolith in a patient presenting with the complaint of recurrent epistaxis for 2 years. A high index of suspicion is needed for diagnosing this condition.

Understanding of multi-level resistive switching mechanism in GeOx through redox reaction in H2O2/sarcosine prostate cancer biomarker detection.

Formation-free multi-level resistive switching characteristics by using 10 nm-thick polycrystalline GeOx film in a simple W/GeOx/W structure and understanding of switching mechanism through redox reaction in H2O2/sarcosine sensing (or changing Ge°/Ge4+ oxidation states under external bias) have been reported for the first time. Oxidation states of Ge0/Ge4+ are confirmed by both XPS and H2O2 sensing of GeOx membrane in electrolyte-insulator-semiconductor structure. Highly repeatable 1000 dc cycles and stable program/erase (P/E) endurance of >106 cycles at a small pulse width of 100 ns are achieved at a low operation current of 0.1 µA. The thickness of GeOx layer is found to be increased to 12.5 nm with the reduction of polycrystalline grain size of <7 nm after P/E of 106 cycles, which is observed by high-resolution TEM. The switching mechanism is explored through redox reaction in GeOx membrane by sensing 1 nM H2O2, which is owing to the change of oxidation states from Ge0 to Ge4+ because of the enhanced O2- ions migration in memory device under external bias. In addition, sarcosine as a prostate cancer biomarker with low concentration of 50 pM to 10 µM is also detected.

Black Phosphorus N-Type Field-Effect Transistor with Ultrahigh Electron Mobility via Aluminum Adatoms Doping.

High-performance black phosphorus n-type field-effect transistors are realized using Al adatoms as effective electron donors, which achieved a record high mobility of >1495 cm2 V-1 s-1 at 260 K. The electron mobility is corroborated to charged-impurity scattering at low temperature, whilst metallic-like conduction is observed at high gate bias with increased carrier density due to enhanced electron-phonon interactions at high temperature.