Coronavirus-19 (COVID-19) is an emerging pandemic that has caused significant disruptions to education, resulting in marked scholar closures across the world. The present study documents the student perception of the online educational process at six universities in Saudi Arabia during the COVID-19 lockdown period. The individual variable factors, i.e., institution, sex, and blended learning, that might influence student perception were also investigated. In this respect, a questionnaire that assessed the impact of COVID-19 on the online learning process and student perception was emailed to a total of 17,230 students from 3 institutions (medical, applied health and dental students) affiliated with six universities in Saudi Arabia. Principal component analysis (PCA) was performed to determine the validity of the questionnaire. A total of 4850 (28%) students responded to the questionnaire and 46.9% (n = 2275) of the respondents were highly satisfied with their online education. Analyses of the scores from the students showed a highly significant difference (p = 0.000) between the male and female students. Applied health students (highly satisfied score = 63.13) were the most satisfied with their online education, while medical students (highly satisfied score = 39.3) were the least satisfied with this education. In addition, applied health, dental and medical students showed a significantly higher score in favor of blended learning after schools re-open (p = 0.000). Collectively, student satisfaction with online education was common, and blended learning was preferred over the traditional format by both genders and all the students. The present data provide interesting contributions and evidence for policy makers and implementers, which might be helpful for the judgment side of decision making.

Aim Osteoporosis, often resulting from estrogen deficiency, is marked by progressive bone loss, oxidative stress, inflammation, and increased cellular apoptosis. This study evaluated the therapeutic efficacy of Tempol, a superoxide dismutase mimetic, in mitigating osteoporotic changes in an ovariectomized (OVX) rat model. Methods Thirty Female Sprague–Dawley rats were assigned to three groups: Sham, OVX, and OVX treated with Tempol (100 mg/kg/day) for 12 weeks via intraperitoneal injection. Results Histological analysis of femoral tissue revealed significant trabecular thinning, increased separation, and reduced osteocyte numbers in the OVX group. These structural impairments were accompanied by decreased serum levels of bone formation markers—alkaline phosphatase (ALP) and osteocalcin—and elevated bone resorption indicators CTX and TRACP-5b. Temporal treatment reversed these changes, improving trabecular architecture and restoring osteocyte density, while normalizing bone turnover markers. Biochemical assays showed that OVX rats had diminished levels of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), indicating heightened oxidative stress. Tempol significantly elevated these enzymes, suggesting enhanced antioxidant defense. Furthermore, Tempol suppressed inflammatory cytokines (TNF-α, IL-6, IL-1β) and pro-apoptotic proteins (Bax, caspase-3) and upregulated the anti-apoptotic marker Bcl-2. Conclusion Overall, Tempol demonstrated a protective role against osteoporosis by improving bone structure, enhancing antioxidant capacity, and modulating inflammatory and apoptotic pathways. These findings support Tempol as a promising candidate for the prevention and treatment of postmenopausal osteoporosis.

The application of tourniquets during limb surgery can lead to ischemia-reperfusion (IR) injury, a pathological process characterized by excessive oxidative stress, increased inflammatory signaling, and progressive muscle fiber damage. Hesperidin, a bioactive flavonoid derived from citrus fruits, is known for its antioxidant and anti-inflammatory properties. This study evaluated the protective effects of hesperidin against lower-limb skeletal muscle IR injury and investigated the molecular pathways potentially associated with these effects. Male Wistar rats were allocated to four groups: control, hesperidin alone, IR (2 h of ischemia followed by 2 h of reperfusion), and IR + hesperidin (100 mg/kg administered 30 min before ischemia). Histological examination of the gastrocnemius muscle was performed, and plasma markers of muscle injury, including creatine kinase (CK), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP), were measured. Oxidative stress and antioxidant parameters (MDA, SOD, CAT, and GPx), components of the Nrf2/HO-1/NQO1 pathway, inflammatory mediators (NF-κB, TNF-α, IL-6, and IL-1β), pyroptosis-associated markers (NLRP3 and caspase-1), and apoptosis-associated proteins (Bax and caspase-3) were also assessed. IR resulted in pronounced muscle fiber disruption, elevated plasma injury markers, increased lipid peroxidation, and reduced antioxidant capacity. IR also decreased Nrf2, HO-1, and NQO1 levels while increasing NF-κB, NLRP3, caspase-1, pro-inflammatory cytokines, and apoptosis-associated proteins. Hesperidin pretreatment markedly attenuated these changes by preserving muscle structural integrity, reducing plasma injury markers and lipid peroxidation, restoring antioxidant enzyme activity, increasing Nrf2/HO-1/NQO1-associated antioxidant responses, and reducing NF-κB-associated inflammatory, NLRP3/caspase-1-associated pyroptotic, and apoptotic responses. Overall, hesperidin pretreatment protected skeletal muscle against tourniquet-induced IR injury and was associated with enhanced Nrf2-mediated antioxidant defenses and attenuation of NF-κB-associated inflammation and NLRP3/caspase-1-associated responses. These findings support further investigation of hesperidin as a potential prophylactic intervention for reducing tourniquet-associated lower-limb IR injury.