Kinetin Capped Zinc Oxide Nanoparticles Improve Plant Growth and Ameliorate Resistivity to Polyethylene Glycol (PEG)-Induced Drought Stress in Vigna radiata (L.) R. Wilczek (Mung Bean).

Plants are sessile and mostly exposed to various environmental stresses which hamper plant growth, development, and significantly decline its production. Drought stress is considered to be one of the most significant limiting factors for crop plants, notably in arid and semi-arid parts the world. Therefore, the present study aimed to evaluate the potential impact of different concentrations (10, 100, and 200 µg/mL) of kinetin capped zinc oxide nanoparticles (Kn-ZnONPs) on Vigna radiata (L.) R. Wilczek under varying levels (5%, 10%, 15%) of PEG-induced drought stress. ZnONPs were synthesized by a co-precipitation method using Zinc acetate as a precursor at pH-12, incinerated to 500 °C, and kinetin was used as a surface functionalizing agent. The resulting Kn-ZnONPs were characterized by various contemporary analytical techniques, including SEM, SEM-EDS, XRD, DLS, and Zeta potential and IR spectroscopy. Crystalline Kn-ZnONPs, with a zeta potential of 27.8 mV and a size of 67.78 nm, of hexagonal wurtzite structure and vibrational stretches associated with N-H, C-O, C-N, etc., were confirmed. PEG-induced drought stress significantly reduced the growth of V. radiata by declining the chlorophyll and carotenoid contents. Moreover, a significant decrease in the levels of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), soluble sugar contents, proline, protein contents, phenol, and tannin were observed compared to the control. However, the exogenous application of Kn-ZnONPs ameliorated all photosynthetic parameters by up-regulating the antioxidant defense system through the promotion of SOD, POD, CAT, and lipid peroxidation levels. The biochemical parameters, such as proteins, soluble sugars, and proline, were observed to be maximum in plants treated with 200 µg/mL Kn-ZnONPs under 5% drought stress. The application of Kn-ZnONPs also enhanced the total phenol contents, flavonoid, and tannin contents. In conclusion, the findings of this study demonstrate that the exogenous application of Kn-ZnONPs provides beneficial effects to V. radiata by attenuating the damaging effects of drought stress through the up-regulation of the antioxidant defense system and osmolytes. These results suggest that Kn-ZnONPs have potential as a novel approach to improve crop productivity under drought stress conditions.

Obstructive Sleep Apnoea in Pakistan: A Single Tertiary Care Center Experience.

INTRODUCTION: Considerable interest has been shown in the field of sleep medicine in recent decades. Obstructive sleep apnoea (OSA) is a common condition that remains neglected in most parts of the world. Data are scarce, if any, when it comes to developing countries. We sought to describe the patient population in a single private tertiary care center from such a country. MATERIALS AND METHODS: A cross-sectional study that included a total of 203 patients over a five-year period was conducted. Polysomnographic studies were conducted in a dedicated sleep laboratory, under the supervision of sleep physicians. Data were described and analyzed based on clinical and self-reported outcomes, as well as polysomnographic characteristics, and compared them between genders and severity. RESULTS: With the participants having an average age of 50.84 years and a BMI of 34.7 kg/m2, the study found that the increase in age and BMI was significantly correlated with an increase in the severity of obstructive sleep apnea in the Pakistani population. There was a significant difference in sleep latency (20.6 min in women vs. 10.8 min in men; p-value = 0.001) and efficiency (63.7% in women vs. 69.8 in men; p-value = 0.02) between the two genders. Decreases in nadir saturation, total sleep time, and sleep latency were also associated with an increase in the level of severity. CONCLUSION: There is a dire need for Pakistani, and in extension Asian, medical professionals to ramp up their pace to meet the needs of their population with regard to sleep medicine.