Selenium Improves Physiological Parameters and Alleviates Oxidative Stress in Strawberry Seedlings under Low-Temperature Stress.

Here, we investigated the effects of selenium (Se) applications on two strawberry varieties, Akihime and Benihoppe, under chilling stress and recovery conditions. Changes in photosynthetic parameters, antioxidant enzyme activities, ascorbate (AsA)-glutathione (GSH) cycle-related enzyme activities, and low-molecular-mass antioxidant contents were determined. Foliar spraying with Se alleviated the decline in the net photosynthetic rate and chlorophyll content and increased the malondialdehyde and hydrogen peroxide contents of strawberry seedlings’ leaves under chilling stress. As the time under chilling stress increased, the stomatal conductance decreased and intercellular CO2 concentration increased, suggesting that nonstomatal factors had major limiting effects on the net photosynthetic rate's decrease. Se applications significantly alleviated the adverse impacts of chilling stress on changes in stomatal conductance and intercellular CO2 concentration. Se, especially at lower concentrations, significantly increased superoxide dismutase, catalase, and peroxide enzyme activities during chilling stress. Approximately 5 mg·L−1 of sodium selenite solution had the greatest stress-alleviating effects. Among the AsA-GSH cycle-related enzymes, ascorbate peroxidase, glutathione reductase, dehydroascorbate reductase, and monodehydroascorbate reductase (MDHAR) treatments, coupled with an appropriate dose of Se, significantly enhanced ascorbate peroxidase and MDHAR activities, which suggested that Se applications played important roles in strawberry leaves by affecting AsA-GSH cycle-related defenses against the oxidative damage caused by chilling stress. Furthermore, MDHAR was the key enzyme required to maintain the balance between AsA consumption and regeneration that may assist in protecting strawberry seedlings in a low-temperature environment.

Effect of HLA-B-associated transcript 3 polymorphisms on lung cancer risk: a meta-analysis.

BACKGROUND: The association between the HLA-B-associated transcript 3 polymorphisms and lung cancer risk is a subject of debate. We conducted a meta-analysis to evaluate the association between these polymorphisms and lung cancer susceptibility. MATERIAL/METHODS: A systematic search of electronic databases (PubMed, EMBASE, Wanfang, and China National Knowledge Infrastructure) was performed. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. RESULTS: Ten case-control studies with 37 945 and 56 807 controls were included in this meta-analysis. Overall, a significant association between rs1052486 polymorphism and lung cancer susceptibility was observed (OR=1.07, 95% CI 1.01-1.12, P=0.01). In addition, a significant association was found for rs3117582 polymorphism (OR=1.29, 95% CI 1.22-1.37, P<0.01). CONCLUSIONS: This meta-analysis suggested that HLA-B-associated transcript 3 polymorphisms are risk factors for lung cancer.

Mitigation effects of exogenous melatonin-selenium nanoparticles on arsenic-induced stress in Brassica napus.

Melatonin (MT) and selenium (Se) application known to decrease heavy metal uptake and toxicity in plants. By mixing the Se in MT medium a new complex MT-Se nanoparticles (MT-Se NPs) was synthesized and we investigated the role of MT-Se NPs on B. napus growth and tolerance against As stress. The MT-Se particles significantly enhanced the plant growth and other associated physiological attributes under As stress. The As treatment at 80 µM was more phytotoxic, however MT-Se NPs application resulted in a substantial increase in leaf chlorophyll fluorescence, biomass accumulation, and decreased ROS relative to As stressed plants. The use of MT-Se NPs to As stressed plants reduced photosynthetic inhibition and oxidative stress and attenuated the increase in MDA and H2O2 contents. The application of MT-Se NPs also boosted the antioxidant enzymes activities such as SOD, POD and CAT as well as the APX, GR and GSH activates under As stress. The results also showed MT-Se NPs treatments alleviated the growth inhibition induced by As and reduced the accumulation of As in leaves and roots of B. napus seedlings. Moreover, treatment with MT-Se NPs improved the plant growth more successfully than treatment of MT and Se alone. This study explored the mechanism of melatonin and selenium efficiency in the composition can be jointly encouraged to exert synergistic effects and boost plant enzymatic activities.

COVID-19 cases with delayed absorption of lung lesion.

OBJECTIVE: Over 90% of the COVID-19 patients with computed tomographic (CT) manifestations showed radiological improvement on dissipating stage. Cases with refractory pulmonary infiltration were discussed in this study. METHODS: During hospitalization, chest CT scan and reverse transcriptase polymerase chain reaction (RT-PCR) test were repeatedly performed. While drawing parallels to RT-PCR, the impact of delayed absorption of lung lesions on length of hospital stay (LOS) and medical expense was investigated. Features for delayed absorption of lung lesions were identified using cox proportional hazard regression model. RESULTS: Cases with delayed absorption of lung lesions had a prolonged LOS (18.00 ± 4.90 vs 9.25 ± 4.20, p < 0.01) and increased medical expense (9124.55 ± 2421.31 vs 4923.88 ± 2218.56, p < 0.01). Time interval from admission to a negative RT-PCR (ATN) was also prolonged (13.29 ± 4.72 vs 9.25 ± 4.20, p = 0.03). The cox proportional hazard regression model indicated that imported cases bore high risk of delayed absorption of lung lesions (hazard ratio = 2.54, 95% confidence interval 1.05, 6.11, p = 0.04). Sensitivity analysis revealed similar pattern (hazard ratio = 6.64, 95% confidence interval 1.62, 27.18, p = 0.01). CONCLUSION: Imported cases of COVID-19 were more likely to have refractory pulmonary infiltration, which subsequently prolongs LOS and increases medical expense.

A novel risk model to predict first-ever ischemic stroke in heart failure with reduced ejection fraction.

Patients with heart failure are at increased risk for ischemic stroke. We aim to develop a more accurate stroke risk prediction tools identify high-risk patients with heart failure with reduced ejection fraction (HFrEF). Patient data were extracted retrospectively from the electronic medical database between January 2009 and February 2019. Univariate and multivariate Cox regression analysis were performed to identify independent predictors, which were utilized to construct a nomogram for predicting ischemic stroke. AUROC analysis was used to compare the prognostic value between the new risk score and CHADS2/CHA2DS2-VASc scores. In 6087 patients with HFrEF, the risk of first-ever ischemic stroke was 5.8% events/pts-years (n=468) during 8007.2 person-years follow-up. A nomogram constructed by integrating 6 variables, including age, atrial fibrillation (AF), deep vein thrombosis (DVT), d-dimer, anticoagulant use and spontaneous echocardiographic contrast (SEC)/left ventricular thrombus (LVT), exhibited a greater area under the curve of 0.727, 0.728 and 0.714 than that by CHADS2 score (0.515, 0.522 and 0.540), and by CHA2DS2-VASc score (0.547, 0.553 and 0.562) for predicting first-ever ischemic stroke at hospitalization, 30-day and 6-month follow-up (all p<0.001). This novel stroke risk score performed better than existing CHADS2/ CHA2DS2-VASc scores and showed improvement in predicting first-ever ischemic stroke in HFrEF patients.

Ursolic Acid Limits Salt-Induced Oxidative Damage by Interfering With Nitric Oxide Production and Oxidative Defense Machinery in Rice.

Crops frequently encounter abiotic stresses, and salinity is a prime factor that suppresses plant growth and crop productivity, globally. Ursolic acid (UA) is a potential signaling molecule that alters physiology and biochemical processes and activates the defense mechanism in numerous animal models; however, effects of UA in plants under stress conditions and the underlying mechanism of stress alleviation have not been explored yet. This study examined the effects of foliar application of UA (100 µM) to mitigate salt stress in three rice cultivars (HZ, 712, and HAY). A pot experiment was conducted in a climate-controlled greenhouse with different salt stress treatments. The results indicated that exposure to NaCl-induced salinity reduces growth of rice cultivars by damaging chlorophyll pigment and chloroplast, particularly at a higher stress level. Application of UA alleviated adverse effects of salinity by suppressing oxidative stress (H2O2, O2-) and stimulating activities of enzymatic and non-enzymatic antioxidants (APX, CAT, POD, GR, GSH, AsA, proline, glycinebutane), as well as protecting cell membrane integrity (MDA, LOX, EL). Furthermore, UA application brought about a significant increase in the concentration of leaf nitric oxide (NO) by modulating the expression of NR and NOS enzymes. It seems that UA application also influenced Na+ efflux and maintained a lower cytosolic Na+/K+ ratio via concomitant upregulation of OsSOS1 and OsHKT1;5 in rice cultivars. The results of pharmacological tests have shown that supply of the NO scavenger (PTI) completely reversed the UA-induced salt tolerance in rice cultivars by quenching endogenous NO and triggering oxidative stress, Na+ uptake, and lipid peroxidation. The PTI application with UA and sodium nitroprusside (SNP) also caused growth retardation and a significant increase in Na+ uptake and oxidative stress in rice cultivars. This suggests that UA promoted salt tolerance of rice cultivars by triggering NO production and limiting toxic ion and reactive oxygen species (ROS) accumulation. These results revealed that both UA and NO are together required to develop a salt tolerance response in rice.