61 research outputs found

    Quantitative investigation of two metallohydrolases by X-ray absorption spectroscopy near-edge spectroscopy

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    The last several years have witnessed a tremendous increase in biological applications using X-ray absorption spectroscopy (BioXAS), thanks to continuous advancements in synchrotron radiation (SR) sources and detector technology. However, XAS applications in many biological systems have been limited by the intrinsic limitations of the Extended X-ray Absorption Fine Structure (EXAFS) technique e.g., the lack of sensitivity to bond angles. As a consequence, the application of the X-ray absorption near-edge structure (XANES) spectroscopy changed this scenario that is now continuously changing with the introduction of the first quantitative XANES packages such as Minut XANES (MXAN). Here we present and discuss the XANES code MXAN, a novel XANES-fitting package that allows a quantitative analysis of experimental data applied to Zn K-edge spectra of two metalloproteins: Leptospira interrogans Peptide deformylase (LiPDF) and acutolysin-C, a representative of snake venom metalloproteinases (SVMPs) from Agkistrodon acutus venom. The analysis on these two metallohydrolases reveals that proteolytic activities are correlated to subtle conformation changes around the zinc ion. In particular, this quantitative study clarifies the occurrence of the LiPDF catalytic mechanism via a two-water-molecules model, whereas in the acutolysin-C we have observed a different proteolytic activity correlated to structural changes around the zinc ion induced by pH variations

    Correlation Analysis Between Required Surgical Indexes and Complications in Patients With Coronary Heart Disease

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    A total of 215 patients with coronary heart disease (CHD) were analyzed with SPSS. Samples of different genders showed significance in the obtuse marginal branch of the left circumflex branch × 1, the diagonal branch D1 × 1, and the ms PV representation. Patients with left circumflex branch occlusion are more male and tend to be younger. Age displayed a positive correlation with left intima-media thickness (IMT) and right IMT. This indicated that as age increases, the values of left IMT and right IMT increase. Samples of different CHD types showed significance in the obtuse marginal branch of the left circumflex branch × 1, the middle part of RCA × 1, and the middle part of the left anterior descending branch × 1.5. For non-ST-segment elevation angina pectoris with acute total vascular occlusion, the left circumflex artery is the most common, followed by the right coronary artery and anterior descending branch. Ultrasound of carotid IMT in patients with CHD can predict changes in left ventricular function, but no specific correlation between left and right common carotid IMT was found. Samples with or without the medical history of ASCVD showed significance in the branch number of coronary vessel lesions. The value of the branch number of coronary vessel lesions in patients with atherosclerotic cardiovascular disease (ASCVD) was higher than in those without ASCVD. The occurrence of complication is significantly relative with the distance of left circumflex branch × 1, the middle segment of left anterior descending branch × 1.5, and the distance of left anterior descending branch × 1. For patients without complications, the values in the distal left circumflex branch × 1, the middle left anterior descending branch × 1.5, and the distal left anterior descending branch × 1 were higher than those for patients with complications. The VTE scores showed a positive correlation with the proximal part of RCA × 1, the branch number of coronary vessel lesions, the posterior descending branch of left circumflex branch × 1, the distal part of left circumflex branch × 1, and the middle part of left anterior descending branch × 1.5

    Psychoeducational Intervention Benefits the Quality of Life of Patients with Active Systemic Lupus Erythematosus

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    Objectives. Systemic lupus erythematosus (SLE) is a complex and relapsing autoimmune disease and worsens the quality of life (QOL) of patients by affecting their physical and psychological status. The effectiveness of psychoeducational interventions on patients with active SLE was investigated. Methods. Eight-five patients with active SLE were randomly assigned to an observation group or a control group; patients in the observation group received psychoeducational interventions. The following variables were evaluated within a week after admission, 3 and 6 months after psychoeducational intervention: the World Health Organization Quality of Life Instrument- (WHOQOL-) BREF scores, the Medical Outcomes Study Short Form 36 (SF-36) scores, the Beck Depression Inventory, and Spielberger’s State-Trait Anxiety Inventory (STAI). Results. We found that scores of all four domains of the WHOQOL-BREF scale were remarkably increased 3 months after psychoeducational intervention in the intervention group and significantly higher than the control group (P<0.05); 6 months after psychoeducational intervention, psychological and social domain scores of the WHOQOL-BREF scale were remarkably higher in the intervention group than those in the control group, while other scores of three domains were not. PF, RP, BP, GH, RE, and MH scores of the SF-36 scale were remarkably increased 3 months after psychoeducational intervention in the intervention group rather than VT and SF, while all scores of subscales were notably higher in the intervention group than those in the control group (P<0.05). Six months after psychoeducational intervention, PF, RP, BP, GH, and RE scores of the SF-36 scale were remarkably higher in the intervention group than those in the control group, while VT, SF, and MH scores were not. Three months after psychoeducational intervention, the levels of depression and anxiety of SLE patients were reduced and significantly lower than those in the control group (P<0.05). Six months after psychoeducational intervention, the level of depression was still reduced, while the level of anxiety was not. Compared with the control group, the levels of depression and anxiety of SLE patients were remarkably declined in the observation group 6 months after psychoeducational intervention (P<0.05). Conclusion. These data suggest psychoeducational interventions can significantly improve and maintain the QOL of patients with active SLE

    Composition of Lycium barbarum polysaccharides and their apoptosis-inducing effect on human hepatoma SMMC-7721 cells

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    Background: Lycium barbarum polysaccharide (LBP) is a natural functional component that has a variety of biological activities. The molecular structures and apoptosis-inducing activities on human hepatoma SMMC-7721 cells of two LBP fractions, LBP-d and LBP-e, were investigated. Results: The results showed that LBP-d and LBP-e both consist of protein, uronic acid, and neutral sugars in different proportions. The structure of LBP was characterized by gas chromatography, periodate oxidation, and Smith degradation. LBP-d was composed of eight kinds of monosaccharides (fucose, ribose, rhamnose, arabinose, xylose, mannose, galactose, and glucose), while LBP-e was composed of six kinds of monosaccharides (fucose, rhamnose, arabinose, mannose, galactose, and glucose). LBP-d and LBP-e blocked SMMC-7721 cells at the G0/G1 and S phases with an inhibition ratio of 26.70 and 45.13%, respectively, and enhanced the concentration of Ca2 + in the cytoplasm of SMMC-7721. Conclusion: The contents of protein, uronic acid, and galactose in LBP-e were much higher than those in LBP-d, which might responsible for their different bioactivities. The results showed that LBP can be provided as a potential chemotherapeutic agent drug to treat cancer

    Dual-targeted carbon-dot-drugs nanoassemblies for modulating Alzheimer's related amyloid-β aggregation and inhibiting fungal infection

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    Amyloid aggregation and fungal infection, especially amyloid beta (Aβ) peptide and Candida albicans are considered as two of the crucial pathogenic agents in Alzheimer's disease (AD). In this work, we propose an innovative treatment strategy for AD, targeting at not only Aβ aggregation but also Candida albicans infection. Here, a high-performance nanomaterial, namely gCDs-E, have been prepared by self-assembled of glycosylated carbon dots (gCDs) and epigallocatechin-3-gallate (EGCG). Surprisingly, gCDs-E can not only suppress the fibrillation of Aβ and disaggregate Aβ fibrils, but also effectively inhibit the activity of Candida albicans. More importantly, the prepared gCDs-E can effectively cut down the cytotoxicity of amyloid aggregations, and the cell viability reached to 99.2%. In addition, the capability of the gCDs-E for blood brain barrier (BBB) penetration was also observed using a normal mice model. Above all, the gCDs-E greatly cleaned Aβ deposition and improved memory impairment in APP/PS1 transgenic AD model mice, confirming its potential as therapeutic agent for AD treatment

    High performance lithium-ion capacitors based on dynamic matching principle

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    As a new generation of energy storage devices, lithium-ion capacitors (LICs) rationally combine high energy density and high power density, providing an alternative solution for multi-functional electronic equipment and state grid system. However, the dynamic mismatch between the battery-type anode and the capacitor-type cathode seriously limits its development and application. Herein, a high performance LIC simultaneously using carbon materials derived from Ethylenediaminetetraacetic Acid Ferric Sodium Salt (EDTA-Na-Fe) was prepared. By calcination of EDTA-Na-Fe in an inert atmosphere, nitrogen-doped carbon frameworks (NCF) can be obtained which possess a high reversible capacity and excellent rate-capability. Using this NCF as the anode and cathode of the LICs, the hybrid devices with a wide voltage window of 0.5-4.0 V are obtained. The employment of the same materials as the anode and cathode can largely simplify the fabrication process. The energy density of LICs can reach 193.4 Wh·kg-1 at a power density of 225 W·kg-1. This reasonable dynamic matching strategy can be helpful for the application of LICs

    A Nanocrystalline Fe2O3 Film Anode Prepared by Pulsed Laser Deposition for Lithium-Ion Batteries

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    Abstract Nanocrystalline Fe2O3 thin films are deposited directly on the conduct substrates by pulsed laser deposition as anode materials for lithium-ion batteries. We demonstrate the well-designed Fe2O3 film electrodes are capable of excellent high-rate performance (510 mAh g− 1 at high current density of 15,000 mA g− 1) and superior cycling stability (905 mAh g− 1 at 100 mA g− 1 after 200 cycles), which are among the best reported state-of-the-art Fe2O3 anode materials. The outstanding lithium storage performances of the as-synthesized nanocrystalline Fe2O3 film are attributed to the advanced nanostructured architecture, which not only provides fast kinetics by the shortened lithium-ion diffusion lengths but also prolongs cycling life by preventing nanosized Fe2O3 particle agglomeration. The electrochemical performance results suggest that this novel Fe2O3 thin film is a promising anode material for all-solid-state thin film batteries
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