41 research outputs found
ENANTIOSELECTIVE EXTRACTION OF RACEMIC OFLOXACIN BY DI(2-ETHYLHEXYL)PHOSPHORIC ACID AND TARTARIC ACID DERIVATIVES AS MIXED COMPLEX CHIRAL SELECTORS
Creating Visible-to-Near-Infrared Mechanoluminescence in Mixed-Anion Compounds SrZn 2 S 2 O and SrZnSO
Abstract(#br)Mechanoluminescence (ML) materials featuring light emission in response to mechanical stimulus have shown promising applications in damage diagnosis, dynamic force detection, and information storage. However, their applications are greatly limited by a very small number of available ML materials as well as unsatisfied ML spectra. In this paper, we developed novel ML materials with intense ML and super-broad visible-to-near-infrared (470-1600 nm) spectra by incorporating lanthanide ions or transition metals into mixed-anion compounds SrZn 2 S 2 O and SrZnSO. These mixed-anion compounds show a linear relationship between ML intensity and applied force, allowing them to be used in non-contact/multi-touch stress sensing. Moreover, the mixed-anion compounds exhibit multiband near-infrared ML enabling a significant bright-field stress sensing approach without the interference of ambient light. This work offers a unique insight for discovering new ML materials and enriching the ML spectral range, thereby promoting their potential applications in stress intelligent sensors, electronic skins, and human-machine interfaces
Novel ceRNA network construction associated with programmed cell death in acute rejection of heart allograft in mice
BackgroundT cell-mediated acute rejection(AR) after heart transplantation(HT) ultimately results in graft failure and is a common indication for secondary transplantation. It’s a serious threat to heart transplant recipients. This study aimed to explore the novel lncRNA-miRNA-mRNA networks that contributed to AR in a mouse heart transplantation model.MethodsThe donor heart from Babl/C mice was transplanted to C57BL/6 mice with heterotopic implantation to the abdominal cavity. The control group was syngeneic heart transplantation with the same kind of mice donor. The whole-transcriptome sequencing was performed to obtain differentially expressed mRNAs (DEmRNAs), miRNAs (DEmiRNAs) and lncRNAs (DElncRNAs) in mouse heart allograft. The biological functions of ceRNA networks was analyzed by GO and KEGG enrichment. Differentially expressed ceRNA involved in programmed cell death were further verified with qRT-PCR testing.ResultsLots of DEmRNAs, DEmiRNAs and DElncRNAs were identified in acute rejection and control after heart transplantation, including up-regulated 4754 DEmRNAs, 1634 DElncRNAs, 182 DEmiRNAs, and down-regulated 4365 DEmRNAs, 1761 DElncRNAs, 132 DEmiRNAs. Based on the ceRNA theory, lncRNA-miRNA-mRNA regulatory networks were constructed in allograft acute rejection response. The functional enrichment analysis indicate that the down-regulated mRNAs are mainly involved in cardiac muscle cell contraction, potassium channel activity, etc. and the up-regulated mRNAs are mainly involved in T cell differentiation and mononuclear cell migration, etc. The KEGG pathway enrichment analysis showed that the down-regulated DEmRNAs were mainly enriched in adrenergic signaling, axon guidance, calcium signaling pathway, etc. The up-regulated DEmRNAs were enriched in the adhesion function, chemokine signaling pathway, apoptosis, etc. Four lncRNA-mediated ceRNA regulatory pathways, Pvt1/miR-30c-5p/Pdgfc, 1700071M16Rik/miR-145a-3p/Pdgfc, 1700071M16Rik/miR-145a-3p/Tox, 1700071M16Rik/miR-145a-3p/Themis2, were finally validated. In addition, increased expression of PVT1, 1700071M16Rik, Tox and Themis2 may be considered as potential diagnostic gene biomarkers in AR.ConclusionWe speculated that Pvt1/miR-30c-5p/Pdgfc, 1700071M16Rik/miR-145a-3p/Pdgfc, 1700071M16Rik/miR-145a-3p/Tox and 1700071M16Rik/miR-145a-3p/Themis2 interaction pairs may serve as potential biomarkers in AR after HT
Pathogenicity and Impact of HLA Class I Alleles in Aplastic Anemia Patients of Different Ethnicities
Acquired aplastic anemia (AA) is caused by autoreactive T cell-mediated destruction of early hematopoietic cells. Somatic loss of human leukocyte antigen (HLA) class I alleles was identified as a mechanism of immune escape in surviving hematopoietic cells of some patients with AA. However, pathogenicity, structural characteristics, and clinical impact of specific HLA alleles in AA remain poorly understood. Here, we evaluated somatic HLA loss in 505 patients with AA from 2 multi-institutional cohorts. Using a combination of HLA mutation frequencies, peptide-binding structures, and association with AA in an independent cohort of 6,323 patients from the National Marrow Donor Program, we identified 19 AA risk alleles and 12 non-risk alleles and established a potentially novel AA HLA pathogenicity stratification. Our results define pathogenicity for the majority of common HLA-A/B alleles across diverse populations. Our study demonstrates that HLA alleles confer different risks of developing AA, but once AA develops, specific alleles are not associated with response to immunosuppression or transplant outcomes. However, higher pathogenicity alleles, particularly HLA-B*14:02, are associated with higher rates of clonal evolution in adult patients with AA. Our study provides insights into the immune pathogenesis of AA, opening the door to future autoantigen identification and improved understanding of clonal evolution in AA
Advances in structures required of polyphenols for xanthine oxidase inhibition
Abstract Polyphenols have been used as natural medicaments for the management of hyperuricemia for a long history. They have been attracted many interests because of the little side effects in curing hyperuricemia, which is an important advantage over the antihyperuricemic drugs. In this review, the structure–activity relationships for polyphenols as xanthine oxidase (XO) inhibitors were discussed. It is concluded that the presence of hydroxyl groups, which influences the inhibitory effects, is closely related to whether the substitutions increase the steric hindrance or disturb the interaction of flavonoid with the catalytic site of XO, and the increased size of the molecule after glycosylation may increase the steric hindrance between flavonoid and XO, and consequently reducing the competitive inhibition behaviors. However, there is no obtained simple general rule that can comprehensively describe the effects of structural alteration on the inhibition activity because the results are varied among different subclasses of polyphenols. In addition, the inhibition mechanisms are mainly assumed as polyphenol binding to the active site of XO and hindering the entrance of xanthine or the discharge of uric acid and diffusion of O2− radical
Antibacterial Activity of Polyphenols: Structure-Activity Relationship and Influence of Hyperglycemic Condition
Polyphenols are plant-derived natural products with well-documented health benefits to human beings, such as antibacterial activities. However, the antibacterial activities of polyphenols under hyperglycemic conditions have been rarely studied, which could be relevant to their antibacterial efficacy in disease conditions, such as in diabetic patients. Herein, the antibacterial activities of 38 polyphenols under mimicked hyperglycemic conditions were evaluated. The structure-antibacterial activity relationships of polyphenols were also tested and analyzed. The presence of glucose apparently promoted the growth of the bacterial strains tested in this study. The OD600 values of tested bacteria strains increased from 1.09-fold to 1.49-fold by adding 800 mg/dL glucose. The polyphenols showed structurally dependent antibacterial activities, which were significantly impaired under the hyperglycemic conditions. The results from this study indicated that high blood glucose might promote bacterial infection, and the hyperglycemic conditions resulting from diabetes were likely to suppress the antibacterial benefits of polyphenols
Influence of Bovine Serum Albumin-Flavonoid Interaction on the Antioxidant Activity of Dietary Flavonoids: New Evidence from Electrochemical Quantification
Interaction between dietary flavonoids and albumins plays an important role in the bioavailability and bioactivity of flavonoids. Therefore, the influence of this interaction on the antioxidant activity of flavonoid has attracted much interest. In this study, a ceric reducing/antioxidant capacity assay (CRAC) was employed to investigate the effects of albumin-flavonoid interaction on the antioxidant activity of seven common flavonoids. The results obtained from the CRAC assay were also compared separately with the results from the spectrophotometric methods including 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. All the flavonoids show a decreasing in the antioxidant activity detected by CRAC assay, indicting a “masking effect” of bovine serum albumin (BSA)-flavonoid interaction. However, the results from DPPH and FRAP assays were conflicting, which may be attributed to the influence of solvent systems
The influence of executive age, career horizon and incentives on pre-turnover earnings management
In this paper we hypothesize that CEOs will be motivated to manage earnings prior to a turnover decision. This motivation comes from the horizon problem for CEOs nearing retirement age and for CEOs whose profit-based bonus is a large portion of their total compensation. We find that firms in which CEOs are nearing retirement age have large discretionary accruals in the year prior to turnover. Although we find firms with a larger proportion of profit-based bonus pay have larger discretionary accruals, this result is not robust with the inclusion of control variables in the regressions. Copyright Springer Science+Business Media, LLC 2007
Influence of Human Serum Albumin Glycation on the Binding Affinities for Natural Flavonoids
Electrochemical antioxidant screening and evaluation based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE)
In this study, an electrochemical biosensor based on guanine and chitosan immobilized MoS2 nanosheet modified glassy carbon electrode (guanine/CS/MoS2/GCE) was developed and employed for antioxidant screening and antioxidant capacity evaluation. The oxidation peak current of guanine was improved and nearly tripled after modifications of chitosan and MoS2 nanosheet. The immobilized guanine could be damaged by hydroxyl radicals generated in Fenton solution. However, in the presence of antioxidants, the guanine was protected and the oxidation peak current of guanine increased. This process mimics the mechanism of antioxidant protection in human body. The factors affecting preparation of sensor and detection of antioxidant capacity were optimized. At the optimum conditions, the guanine/CS/MoS2/GCE showed wide linear range, low detection limit, satisfactory reproducibility and stability for detection. Ascorbic acid was used as a model antioxidant to evaluate the antioxidant capacity. A good linearity was observed with a correlation coefficient of 0.9959 in the concentrations between 0.5 and 4.0 mg L-1. The antioxidant capacities of three flavonoids were also tested and the rank of antioxidant capacities was ascorbic acid (51.84%), quercetin (45.82%), fisetin (34.39%) and catechin (16.99%). Due to the rapid measurement and low cost, this sensor could provide an available sensing platform for antioxidant screening and evaluation