Synthesis and spectroscopic calf thymus deoxyribonucleic acid binding investigations of luteolin – zinc(II) complex

196-201A luteolin–zinc(II) (lut–Zn) complex has been synthesized by the reaction of luteolin with copper acetate in alcohol. The binding mode of lut–Zn with calf thymus deoxyribonucleic acid (ctDNA) is studied by different spectroscopic methods in pH 7.4 tris(hydroxymethyl)aminomethane–HCl (Tris–HCl) buffer solution. Ultraviolet (UV)–visible absorption spectrophotometry and fluorescence spectroscopy as well as viscosity measurements have proved the formation of lut–Zn–ctDNA complex. Binding constant (Ka) of lut–Zn–ctDNA complex is 4.29 × 104 L mol-1 (310 K). Fluorophotometry measurements has proved that the quenching mechanism of fluorescence of acridine orange (AO)–ctDNA by lut–Zn is static quenching. The thermodynamic parameters entropy change (ΔS), enthalpy change (ΔH) and Gibbs free energy (ΔG) of binding reaction are calculated to be -20.87 J K-1 mol -1, -3.39 × 104 J mol-1 and -2.74 × 104 J mol-1 at 310 K, respectively. Negative values of ΔH and ΔS have indicated that there are hydrogen bonds and van der Waals forces in the binding reaction of lut–Zn with ctDNA. The fluorescence results and UV–visible absorption together have revealed that the interaction mode of lut–Zn to ctDNA is an intercalation mode. This conclusion is further confirmed by viscosity measurements

Maternal control of axial–paraxial mesoderm patterning via direct transcriptional repression in zebrafish

AbstractAxial–paraxial mesoderm patterning is a special dorsal–ventral patterning event of establishing the vertebrate body plan. Though dorsal–ventral patterning has been extensively studied, the initiation of axial–paraxial mesoderm pattering remains largely unrevealed. In zebrafish, spt cell-autonomously regulates paraxial mesoderm specification and flh represses spt expression to promote axial mesoderm fate, but the expression domains of spt and flh initially overlap in the entire marginal zone of the embryo. Defining spt and flh territories is therefore a premise of axial–paraxial mesoderm patterning. In this study, we investigated why and how the initial expression of flh becomes repressed in the ventrolateral marginal cells during blastula stage. Loss- and gain-of-function experiments showed that a maternal transcription factor Vsx1 is essential for restricting flh expression within the dorsal margin and preserving spt expression and paraxial mesoderm specification in the ventrolateral margin of embryo. Chromatin immunoprecipitation and electrophoretic mobility shift assays in combination with core consensus sequence mutation analysis further revealed that Vsx1 can directly repress flh by binding to the proximal promoter at a specific site. Inhibiting maternal vsx1 translation resulted in confusion of axial and paraxial mesoderm markers expression and axial–paraxial mesoderm patterning. These results demonstrated that direct transcriptional repression of the decisive axial mesoderm gene by maternal ventralizing factor is a crucial regulatory mechanism of initiating axial–paraxial mesoderm patterning in vertebrates

Isolation of Thiobacillus spp. and its application in the removal of heavy metals from activated sludge

Two strains of Thiobacillus isolated from native excess activated sludge were identified as Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans by 16S rRNA gene sequencing and physiological-biochemical characteristics. Single and mixed cultures of the strains were used to carry out bioleaching for 9 days in order to remove heavy metals from activated sludge. The changes in pH, oxidation-reduction potential, and contents of heavy metals were measured. The results show that the bioleaching effect of the mixed culture was best in all runs, and that the final removals of As, Cr, Cu, Ni, and Zn were 96.09, 93.47, 98.32, 97.88, and 98.60%, respectively, whereas the removals of Cd and Pb decreased rapidly after six days. In addition, we demonstrate for the first time that bioleaching can reduce the pathogenicity of sludge by detecting fecal coliforms before and after bioleaching in order to ensure that the sludge was suitable for agricultural land application.Key words: Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, excess activated sludge, removing heavy metals, sludge pathogenicity

Convergence and Stability in Collocation Methods of Equation u

This paper is concerned with the convergence, global superconvergence, local superconvergence, and stability of collocation methods for u′(t)=au(t)+bu([t]). The optimal convergence order and superconvergence order are obtained, and the stability regions for the collocation methods are determined. The conditions that the analytic stability region is contained in the numerical stability region are obtained, and some numerical experiments are given

Total ginsenosides suppress monocrotaline-induced pulmonary hypertension in rats: involvement of nitric oxide and mitogen-activated protein kinase pathways

AbstractBackgroundGinsenosides have been shown to exert beneficial pharmacological effects on the central nervous, cardiovascular, and endocrine systems. We sought to determine whether total ginsenosides (TG) inhibit monocrotaline (MCT)-induced pulmonary hypertension and to elucidate the underlying mechanism.MethodsMCT-intoxicated rats were treated with gradient doses of TG, with or without NG-nitro-l-arginine methyl ester. The levels of molecules involving the regulation of nitric oxide and mitogen-activated protein kinase pathways were determined.ResultsTG ameliorated MCT-induced pulmonary hypertension in a dose-dependent manner, as assessed by the right ventricular systolic pressure, the right ventricular hypertrophy index, and pulmonary arterial remodeling. Furthermore, TG increased the levels of pulmonary nitric oxide, endothelial nitric oxide synthase, and cyclic guanosine monophosphate. Lastly, TG increased mitogen-activated protein kinase phosphatase-1 expression and promoted the dephosphorylation of extracellular signal-regulated protein kinases 1/2, p38 mitogen-activated protein kinase, and c-Jun NH2-terminal kinase 1/2.ConclusionTG attenuates MCT-induced pulmonary hypertension, which may involve in part the regulation of nitric oxide and mitogen-activated protein kinase pathways

Integrating HIV and mental health interventions to address a global syndemic among men who have sex with men

In this Series paper, we review evidence on the co-occurring and synergistic epidemics (syndemic) of HIV and mental health problems worldwide among men who have sex with men (MSM). The multilevel determinants of this global syndemic include structural factors that enable stigma, systematic bias, and violence towards MSM across geographical and cultural contexts. Cumulative exposure to these factors over time results in population-level inequities in the burden of HIV infections and mental health problems among MSM. Evidence for this syndemic among MSM is strongest in the USA, Canada, western Europe, and parts of Asia and Latin America, with emerging evidence from sub-Saharan Africa. Integrated interventions are needed to address syndemics of HIV and mental health problems that challenge the wellbeing of MSM populations worldwide, and such interventions should consider various mental health conditions (eg, depression, anxiety, trauma, and suicidality) and their unique expressions and relationships with HIV outcomes depending on cultural contexts. In addition, interventions should identify and intervene with locally relevant structural factors that result in HIV and mental health vulnerabilities among MSM

Psychiatric Symptoms, Risk, and Protective Factors Among University Students in Quarantine During the COVID-19 Pandemic in China

Background: The COVID-19 pandemic has made unprecedented impact on the psychological health of university students, a population vulnerable to distress and mental health disorders. This study investigated psychiatric symptoms (anxiety, depression, and traumatic stress) during state-enforced quarantine among university students in China (N = 1912) through a cross-sectional survey during March and April 2020. Results: Psychiatric symptoms were alarmingly prevalent: 67.05% reported traumatic stress, 46.55% had depressive symptoms, and 34.73% reported anxiety symptoms. Further, 19.56% endorsed suicidal ideation. We explored risk and protective factors of psychological health, including demographic variables, two known protective factors for mental health (mindfulness, perceived social support), four COVID-specific factors (COVID-19 related efficacy, perceived COVID-19 threat, perceived COVID-19 societal stigma, COVID-19 prosocial behavior) and screen media usage. Across symptom domains, mindfulness was associated with lower symptom severity, while COVID-19 related financial stress, perceived COVID-19 societal stigma, and perceived COVID-19 threat were associated with higher symptom severity. COVID-19 threat and COVID-19 stigma showed main and interactive effects in predicting all mental health outcomes, with their combination associated with highest symptom severity. Screen media device usage was positively associated with depression. Female gender and COVID-19 prosocial behavior were associated with higher anxiety, while COVID-19 self-efficacy associated with lower anxiety symptoms. Conclusions: Findings suggest high need for psychological health promotion among university students during the COVID-19 pandemic and inform an ecological perspective on the detrimental role of stigma during an emerging infectious disease outbreak. Interventions targeting multi-level factors, such as promoting mindfulness and social support at individual and interpersonal levels while reducing public stigma about COVID-19, may be particularly promising. Attending to the needs of disadvantaged groups including those financially impacted by COVID-19 is needed

Niacin Inhibits Apoptosis and Rescues Premature Ovarian Failure

Background/Aims: Over 99% of mouse and human ovarian follicles will undergo specialized cell death including atresia and apoptosis. Reduction of apoptosis may help reduce infertility and maintain the reproductive ability in women. Methods: 3-day B6D2F1 mice were used to culture small follicle and ovary tissue with niacin and 18-day mice were intraperitoneal injected with niacin to determine its effect on follicle development. Then establish 8-weeks POF animal model with cytoxan (CTX) or radiation. Treatment group was given 0.1 mL of 100 mM niacin by an intraperitoneal injection twice before ovulation. The ovaries were collected and the follicles were counted and categorized, and ovarian histologic sections were stained for TUNEL. Ovarian function was then evaluated by monitoring ovulation. Microarray analyses, Western blot, immunofluorescence and real-time quantitative PCR were used to assess the mechanism of ovarian injury and repair. Results: We found that niacin promotes follicle growth in the immature oocyte and it increased the levels of a germ-line cell marker DDX4, and a cell proliferation marker PCNA in the ovary. Addition of niacin to the cell culture reduced oocyte apoptosis in vitro. Administration of niacin to treat premature ovarian failure (POF) in mouse models showed inhibition of follicular apoptosis under harmful conditions, such as radiation and chemotherapy damage, by markedly reducing cumulus cell apoptosis. Additionally, the number of developing follicles increased after administration of niacin. Conclusion: Niacin may have an important function in treating POF by reducing apoptosis in clinical applications

System metabolic tools reveal fucoxanthin metabolism in Nitzschia laevis for the improvement of fucoxanthin productivity

The production of fucoxanthin from microalgae is rapidly gaining popularity due to its exceptional productivity, lack of contamination, and straightforward extraction process. However, the optimal conditions for increasing biomass concentration and/or fucoxanthin content through the manipulation of light and carbon sources are context specific. This study explored fucoxanthin metabolism in Nitzschia laevis under heterotrophic and mixotrophic conditions using 13C tracer-based metabolic flux analysis, targeted metabolomics, and transcriptome analysis. Mixotrophic culture at 10 μmol m-2 s-1 improved fucoxanthin content by 27.54% but decreased biomass concentration by 15.65% compared to heterotrophic culture. At the molecular level, exposure to low light results in a reduction in carbon flux in the TCA cycle, leading to an increased flux toward carotenoid and fatty acid biosynthesis. The accumulation of high levels of citrate, isocitrate, and α-ketoglutaric acid is attributed to the reduced activity of the TCA cycle. Moreover, the metabolism of glyceraldehyde-3-phosphate and phosphoenolpyruvate was found to be more active under mixotrophic cultivation than heterotrophic ones, resulting in a substantial accumulation of fucoxanthin. The higher ATP and NADPH consumption provided sufficient energy for fucoxanthin and fatty acid biosynthesis. Furthermore, gene expression analysis revealed that low light upregulated the genes involved in fucoxanthin biosynthesis and promoted the violaxanthin cycle, especially after 12 h of cultivation. To improve fucoxanthin productivity, low light conditions were applied after a fed-batch culture, resulting in a 22.92% increase in fucoxanthin accumulation. The findings of this study offer valuable insights into the advantages of employing multi-stage cultivation techniques to improve microalgal production

Glycolipid Metabolism Disorder in the Liver of Obese Mice Is Improved by TUDCA via the Restoration of Defective Hepatic Autophagy

Objective. Tauroursodeoxycholic acid (TUDCA) has been considered an important regulator of energy metabolism in obesity. However, the mechanism underlying how TUDCA is involved in insulin resistance is not fully understood. We tested the effects of TUDCA on autophagic dysfunction in obese mice. Material and Methods. 500 mg/kg of TUDCA was injected into obese mice, and metabolic parameters, autophagy markers, and insulin signaling molecular were assessed by Western blotting and real-time PCR. Results. The TUDCA injections in the obese mice resulted in a reduced body weight gain, lower blood glucose, and improved insulin sensitivity compared with obese mice that were injected with vehicle. Meanwhile, TUDCA treatment not only reversed autophagic dysfunction and endoplasmic reticulum stress, but also improved the impaired insulin signaling in the liver of obese mice. Additionally, the same results obtained with TUDCA were evident in obese mice treated with the adenoviral Atg7. Conclusions. We found that TUDCA reversed abnormal autophagy, reduced ER stress, and restored insulin sensitivity in the liver of obese mice and that glycolipid metabolism disorder was also improved via the restoration of defective hepatic autophagy