Design and fabrication of La-based perovskites incorporated with functionalized carbon nanofibers for the electrochemical detection of roxarsone in water and food samples

The pentavalent arsenic compound roxarsone (RSN) is used as a feed additive in poultry for rapid growth, eventually ending up in poultry litter. Poultry litter contains chicken manure, which plays a vital role as an affordable fertilizer by providing rich nutrients to agricultural land. Consequently, the extensive use of poultry droppings serves as a conduit for the spread of toxic forms of arsenic in the soil and surface water. RSN can be easily oxidized to release highly carcinogenic As(III) and As(IV) species. Thus, investigations were conducted for the sensitive detection of RSN electrochemically by developing a sensor material based on lanthanum manganese oxide (LMO) and functionalized carbon nanofibers (f-CNFs). The successfully synthesised LMO/f-CNF composite was confirmed by chemical, compositional, and morphological studies. The electrochemical activity of the prepared composite material was examined using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained results confirmed that LMO/f-CNF showed enhanced electrocatalytic activity and improved current response with a good linear range (0.01-0.78 μM and 2.08-497 μM, respectively), exhibiting a low limit of detection (LOD) of 0.004 μM with a high sensitivity of 13.24 μA μM-1 cm-2 towards the detection of RSN. The noteworthy features of LMO/f-CNF composite with its superior electrochemical performance enabled reliable reproducibility, exceptional stability and reliable practical application in the analysis of tap water and food sample, affording a recovery range of 86.1-98.87%.

Prevalence and Visual Outcomes of Cataract Surgery in Rural South India: A Cross-Sectional Study

PURPOSE

To determine the prevalence of cataract surgery and postoperative vision-related outcomes, especially with respect to sex, socioeconomic status (SES) and site of first contact with eye care, in a rural area of South India.

METHODS

In a population-based cross-sectional survey of 5530 individuals aged 50 years or older from 10 villages selected by cluster sampling, individuals who had undergone cataract surgery in one or both eyes were identified. Consenting participants were administered a questionnaire, underwent vision assessment and ophthalmic examination. Outcomes were classified as good if visual acuity of the operated eye was 6/18 or better, fair if worse than 6/18 but better than or equal to 6/60, and poor if worse than 6/60.

RESULTS

Prevalence of cataract surgery in this age group (771 persons) was 13.9% (95% confidence interval, CI, 13.0-14.9%). In the 1112 eyes of 749 persons studied, at presentation, 53.1% (95% CI 50.1-56.1%) of operated eyes had good, 38.1% (95% CI 35.2-41.0%) had fair, and 8.8% (95% CI 7.1-10.5%) had poor outcomes. With pinhole, 75.2% (95% CI 72.6-77.8%) had good, 17.2% (95% CI 14.9-19.5%) had fair, and 7.4% (95% CI 5.8-9.0%) had poor outcomes. In 76.3% of eyes with fair and poor presenting outcomes we detected an avoidable cause for the suboptimal visual acuity. Place of surgery and duration since surgery of 3 years or more were risk factors for blindness, while SES, sex and site of first eye care contact were not.

CONCLUSION

The high prevalence of avoidable causes of visual impairment in this rural setting indicates the scope for preventive strategies.

In vitro antioxidant and antibacterial activity of Rhaphidophora pertusa stem

Methanol extract of Rhaphidophora pertusa stem was analyzed for its antioxidant (DPPH, reducing power and Fe(3+) metal chelation methods) and antibacterial activities. The extract was found effective against the three antioxidant test models and exhibited strong and moderate antibacterial activity against the tested pathogenic bacteria.