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Hair shafts from three trichothiodystrophy (TTD) patients with mutations in the ERCC2 (XPD) gene were examined by transmission electron microscopy. TTD is a rare, recessive disorder with mutations in several genes in the DNA repair/transcription pathway, including ERCC2. Unlike previous studies, the hair shafts were examined after relaxation of their structure by partial disulphide bond reduction in the presence of sodium dodecyl sulphate, permitting improved visualization. Compared with hair shafts of normal phenotype, TTD cuticle cells displayed aberrant marginal bands and exocuticle layers. Clusters of cells stained differently (light versus dark) in the cortex of aberrant shafts, and the keratin macrofibrils appeared much shorter in the cytoplasm. Considerable heterogeneity in these properties was evident among samples and even along the length of single hair shafts. The results are consistent with not only a paucity of high sulphur components, such as keratin-associated proteins, but also a profound imbalance in protein content and organization.

Organic compounds display several electronic and structural features which enable their application in various fields, ranging from biological to non-biological. These compounds contain heteroatoms like sulfur, nitrogen and oxygen, which provide coordination sites to act as ligands in the field of coordination chemistry and are used as chemosensors to detect various metal ions. This review article covers different organic compounds including thiourea, Schiff base, pyridine, thiophene, coumarin, triazolyl pyrenes, imidazole, fluorescein, thiazole, tricarbocyanine, rhodanine, porphyrin, hydrazone, benzidine and other functional groups based chemosensors, that contain heteroatoms like sulfur, nitrogen and, oxygen for fluorimetric and colorimetric detection of Ag+ in different environmental, agricultural, and biological samples. Further, the sensing mechanism and performances of these chemosensors have been discussed, which could help the readers for the future design of highly efficient, selective, and sensitive chemosensors for the detection and determination of Ag+ ions. [ABSTRACT FROM AUTHOR]

Rapid detection of potentially toxic heavy metals like Hg(II) has attracted great attention in the last few decades due to the importance to maintain a safe and sustainable environment for human beings. Coordination chemistry and concepts therein, play an important role in the detection of Hg(II). Size, charge, and nature of the donor atom and the respective cation (metal ion), are crucial in selective interactions between the sensor and metal ions. The sensors designed for the purpose, coordinate to Hg(II) ion through various donor sites, coordination causes a change in the electron density in organic molecules and results in either visible color change or enhancing/quenching fluorescence intensity. Since Hg(II) is soft metal, with d10 electron system, so majority of the sensors have soft donor sites which prefer to coordinate with Hg(II). Oxygen is also present in some chelating ligands which is least preferred coordination site, due to its hard nature. There are several reports of replacing other ligating sites by sulfur for enhanced mercury sensing. In some cases, desulfurization is being detected as clear change in spectral behavior during the sensing process. Efforts are still in progress to design and introduce a sensor with utmost sensitivity and selectivity. In this review, we made an attempt to explain the coordination aspects of Hg(II) detectors, reasons for poor efficiency and possible suggestions to improve the selection criterion of various compounds. It will help researchers to know about important concepts in designing more sensitive and selective sensors for detection of Hg(II) in environmental and biological samples. [ABSTRACT FROM AUTHOR]

Methanol oxidation stands out as a pivotal solution in addressing the global energy crisis and environmental pollution, owing to its practical applicability, high current density, and the ready availability of methanol as a fuel source. To effectively catalyze methanol oxidation, an electrocatalyst is imperious to overcome the activation energy barrier. Herein, a three‐dimensionally arranged NiSe2 nanosheet‐based electrocatalyst is synthesized through a facile solvothermal followed by an annealing method. The catalyst's porous structure enhances catalytic efficiency by providing a substantial electrochemical surface area (ECSA) equivalent to 0.121 mF cm−2. Notably, the electrocatalyst exhibits a remarkable response of 21.58 mA cm−2 at an overpotential of 1.70 V vs RHE, accompanied by the lowest Tafel slope recorded at 39.14 mV dec−1. The electronic circuit, represented by Rs(Qf(RfW(QdlRct)), aligns well with electrochemical impedance spectroscopy data, elucidating the reaction path and intrinsic properties. Furthermore, the catalytic performance is elucidated concerning ECSA and weight, revealing current densities of 5.60 mA cm−2 and 71.34 mA mg−1, respectively. Impressively, the catalyst demonstrates exceptional resistance to poisoning and sustained stability over a continuous 3600‐s operation. This comprehensive study underscores the promising potential of the NiSe2 nanosheet‐based electrocatalyst for efficient methanol oxidation, providing valuable insights for advancing clean energy technologies. [ABSTRACT FROM AUTHOR]

The discovery of one-dimensional (1D) materials and their applications in cutting-edge technologies like spintronics has led to extensive efforts being devoted to their theoretical and experimental research. Here, by using first principles density functional theory (DFT) calculations, we systematically investigate the properties of zigzag boron nitride nanoribbons (ZBNNRs) over edge passivation (X = H, F, Cl, NH2, NO2, OH, CH3, and COOH), and varying widths. Numerical results demonstrate that single nitrogen edge passivation and both edge passivation show semiconducting and insulating behaviour, but single boron edge passivation shows fully spin-polarized Dirac fermions at the Fermi level in the minority spin, and the opposite spin has a tuneable band gap over a wide range (0.9–5.1 eV). Upon changing different chemical groups, the band gap between Dirac points can also be manipulated (0.01–0.14 eV). Ab initio molecular dynamics result in stable NRs at room temperature and Curie temperature for ZBNNRs-BX shows ferromagnetism (FM) above room temperature. Spin-polarized projected density of states (SP-PDOS) provides a detailed origin of edge states, their importance in metal to non-metal transition, as well as insights into the Dirac points. Interestingly SP-PDOS reveals that only bare edge states are responsible for electric flow and FM, independent of the NR width. Therefore, this work showcases intrinsic half metallicity and provides a detailed way of revealing the spin-polarized Dirac fermion nature of edge passivated ZBNNRs showing potential applications towards BN based, low consumption, and thermally stable spintronic nano-devices. [ABSTRACT FROM AUTHOR]