Visible light-driven C-C bond formation to produce C2-based liquid fuel selectively from CO2 is of great interest and remains a challenging task due to uphill electron transfer kinetics. Herein, we...

In the quest for renewable fuel production, the selective conversion of CO2 to CH4 under visible light in water is a leading-edge challenge considering the involvement of kinetically sluggish multiple elementary steps. Herein, 1-pyrenebutyric acid is post-synthetically grafted in a defect-engineered Zr-based metal organic framework by replacing exchangeable formate. Then, methyl viologen is incorporated in the confined space of post-modified MOF to achieve donor-acceptor complex, which acts as an antenna to harvest visible light, and regulates electron transfer to the catalytic center (Zr-oxo cluster) to enable visible-light-driven CO2 reduction reaction. The proximal presence of the charge transfer complex enhances charge transfer kinetics as realized from transient absorption spectroscopy, and the facile electron transfer helps to produce CH4 from CO2. The reported material produces 7.3 mmol g−1 of CH4 under light irradiation in aqueous medium using sacrificial agents. Mechanistic information gleans from electron paramagnetic resonance, in situ diffuse reflectance FT-IR and density functional theory calculation.

The granulomas of lupus vulgaris (LV) were characterized by preponderance of CD4+ lymphocytes and a raised CD4+/CD8+ ratio. In contrast, in scrofuloderma (SF) the CD8+ T-lymphocyte subpopulation predominated and the CD4+/CD8+ ratio was significantly decreased. A higher percentage of lymphocytes expressed interleukin-2 receptor (IL-2R) in LV as compared with SF, indicating an activated cellular immune response in the former. Immunophenotypic changes in tuberculosis verrucosa cutis (TBVC) were intermediate between LV and SF. CD4+ lymphocytes were the main infiltrating T-cell type in borderline tuberculoid leprosy (BT), while CD8+ lymphocytes predominated in the granuloma of lepromatous lepromatous (LL). The CD4+/CD8+ ratio and percentage of lymphocytes expressing IL-2R was significantly higher in BT as compared with LL. These immunophenotypic findings suggest that in both cutaneous tuberculosis and leprosy there is a continuous spectrum with regard to cell-mediated immunity depending on the clinical presentation.

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An unusual association of scrofuloderma of the scalp, psoas abscess, and caries spine was seen in a 4-year-old girl. The diagnosis was confirmed by relative and absolute criteria. The peripheral T-lymphocytes and their subsets were within normal limits, although her immunohistopathological changes indicated an intermediary response across the spectrum depicting an unstable immunity. This may have been responsible for the silent spread of Mycobacterium tuberculosis and the current association.

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Severe acute respiratory virus syndrome coronavirus 2 (SARS-CoV-2) was responsible for coronavirus disease (COVID-19) pandemic, which resulted in global health care crisis. As patients recovered from COVID-19 infection, hair loss was increasingly observed as a distressing symptom. We conducted a prospective cross-sectional study of patients presenting with post COVID-19 hair loss between July to December 2021 at a tertiary care centre in north India. Detailed history, clinical examination, trichoscopy and biochemical tests were performed and recorded. COVID-19 disease severity was assessed based on the duration of COVID-19 infection and place of management (home or hospitalized). The study included 120 patients with mean age being 39.6 years. There was female preponderance. Majority of the patients (87%) were treated at home and 43.3% had COVID-19 infection for >2 weeks. Mean visual analog scale (VAS) score for stress was 5.25. Vitamin D deficiency was present in 56.7% and low ferritin in 30% of cases. Mean time of onset of hair loss post COVID-19 was 49 days. Patients mainly presented with diffuse (72.4%) and patterned hair loss (31.6%). Trichodynia was present in 15.8% of cases. The degree of hair loss was severe in 55.8% of the subjects, predominantly in older age group and females. Positive hair pull test was seen in 65% of patients. Most common trichoscopic features included single hair follicles’ (81.7%) and vellus hair >10% (60%). Trichoscopy can aid in unmasking co-existing patterned hair loss in patients presenting clinically with diffuse hair loss. Patients with COVID-19 infection for > 2 weeks had significantly more severe hair loss and VAS score. Trichoscopic findings of vellus hair >10% and empty hair follicles were more frequent in patients who were hospitalized for COVID-19 infection.