18 research outputs found
A novel tension monitoring device of multi-rope friction hoister by using acoustic filtering sensor
Wire rope tension is one of the vital monitoring parameters for the hoister system, which seriously influence mine coal safety production. However, wire ropes endure vibration and shock in lifting process of multi-rope friction hoisters in coal mine, which interferes with measurement of wire rope tension and lifting load seriously. Aimed to the difficulty of monitoring wire rope tension, this paper put forward a new measurement method of wire rope tension by transferring wire rope tension measurement to pressure measurement, which improves the measurement safety and avoids the safety hazards of adopting pull sensor in series with wire rope, and this paper also designed an acoustic filtering sensor which uses the filtering characteristic of acoustic cavity to eliminate the effect of vibration and shock in wire rope tension measurement. Meanwhile, a novel wire rope tension monitoring device of multi-rope friction hoister is presented based on the proposed measurement method and sensor, which can measure each wire rope tension in the lifting process, display the cage load and monitor the fault of wire rope tension unbalance. Real-time and accurate wire rope tension measurement is realized. By comparing the signals measured by the common sensor and the acoustic filtering sensor, the influence of vibration and shock on the multi-ropes tension measurement is eliminated, and the fault of wire rope tension unbalance can be monitored. This advanced tension monitoring device is of great significance to the safety of coal mine production
Molecular shape and immunogenicity of meningococcal polysaccharide group A conjugate vaccine
Neisseria meningitidis is a leading cause of severe bacterial infections in infants and young children. As a major virulence factor, meningococcal capsular polysaccharide (PS) is poorly immunogenic and generally does not induce immunological memory. Conjugation of PS with a carrier protein can significantly increase the PS-specific immunogenicity and induce immunological memory. It is well known that the molecular shape/size of the conjugate vaccine is important for its immunogenicity. However, little is known about the molecular shape/size of the meningococcal conjugate vaccine. A meningococcal PS ovalbumin (OVA) conjugate vaccine was prepared using cystamine as linker. Four components (P1-P4) with different molecular size were fractionated from the conjugate. Small angle X-ray scattering (SAXS) analysis revealed that the conjugate vaccine exhibited a rod-like shape similar to virus-like particles. PS-specific immunogenicity of the conjugate vaccine was related to its molecular shape and increased as a function of its molecular size. Thus, the present study provides a three-dimensional shape of the conjugate vaccine and helps to identify optimal design of a potent meningococcal conjugate vaccine. (C) 2015 Elsevier Ltd. All rights reserved
TiO2-Horseradish Peroxidase Hybrid Catalyst Based on Hollow Nanofibers for Simultaneous Photochemical-Enzymatic Degradation of 2,4-Dichlorophenol
Degradations of 2,4-dichlorophenol (2,4-DCP) using TiO2/UV photochemical and horseradish peroxidase (HRP) enzymatic treatments, as well as simultaneous photochemical enzymatic treatments, by combining these two processes were systematically investigated and compared. When free HRP was used in the simultaneous process, a negative synergetic effect was observed due to serious inactivation of the HRP caused by UV irradiation in the presence of TiO2. A hybrid catalyst system was then developed by in situ encapsulating HRP inside nanochambers of TiO2-doped hollow nanofibers through coaxial electrospinning. Such encapsulation effectively avoided UV-induced deactivation of the enzymes, thus the 2,4-DCP degradation efficiency was improved significantly as compared with the that using HRP or TiO2/UV either separately or simultaneously in free formation. Furthermore, the higher the concentration of 2,4-DCP, the more remarkable the enhancement achieved, such that a 90% removal ratio was obtained within only 3 h for the degradation of 10 mM 2,4-DCP using the integrated TiO2 HRP hybrid catalyst system. While the removal ratio obtained with dispersed TiO2/UV, TiO2 doped in PU hollow nanofibers, free HRP, combination of dispersed TiO2 and free HRP under UV, as well as the encapsulated HRP, were only 31.37%, 27.98%, 49.71%, 36.53%, and 58.32%, respectively. The hybrid catalysts system also showed excellent recycling capability and thermal stability
Acetyl-CoA Synthetase 2 as a Therapeutic Target in Tumor Metabolism
Acetyl-CoA Synthetase 2 (ACSS2) belongs to a member of the acyl-CoA short-chain synthase family, which can convert acetate in the cytoplasm and nucleus into acetyl-CoA. It has been proven that ACSS2 is highly expressed in glioblastoma, breast cancer, liver cancer, prostate cancer, bladder cancer, renal cancer, and other tumors, and is closely related to tumor stage and the overall survival rate of patients. Accumulating studies show that hypoxia and a low serum level induce ACSS2 expression to help tumor cells cope with this nutrient-poor environment. The potential mechanisms are associated with the ability of ACSS2 to promote the synthesis of lipids in the cytoplasm, induce the acetylation of histones in the nucleus, and facilitate the expression of autophagy genes. Novel-specific inhibitors of ACSS2 are developed and confirmed to the effectiveness in pre-clinical tumor models. Targeting ACSS2 may provide novel approaches for tumor treatment. This review summarizes the biological function of ACSS2, its relation to survival and prognosis in different tumors, and how ACSS2 mediates different pathways to promote tumor metastasis, invasion, and drug resistance
Nickel cobalt oxide-single wall carbon nanotube composite material for superior cycling stability and high-performance supercapacitor application
The electron conductivity of electrode material has always been a problem that hinders the practical application of supercapacitor. In this contribution, we report a facile synthesis of highly conductive nickel cobalt oxide-single wall carbon nanotube (NiCo2O4–SWCNT) nanocomposite by controlled hydrolysis process in ethanol–water mixed solvent. Ultrafine NiCo2O4 nanocrystals with a diameter around 6–10 nm are formed on the functionalized SWCNT bundles. This novel material not only exhibits a high specific capacitance of 1642 F g–1 within a 0.45 V potential range but also shows an excellent cycling stability of 94.1% retention after 2000 cycles at high mass loading. Our method provides a promising facile and high-performance strategy for supercapacitor electrode application
Simultaneous Tracing of Protein Vicinal Dithiols in Live Cells Using an “Off-on” Fluorescent Probe
Vicinal dithiol-containing proteins (VDPs) are of considerable importance due to their role in regulating cellular functions through the reversible dithiol/disulfide inter-conversion reaction. However, there are currently no effective tools for the simultaneous tracing of endogenous VDPs in live cells. Here, we report an “off-on” fluorescent probe (RhQ) for the selective detection of VDPs and illustrate its utility for the long-term tracing of protein vicinal dithiols with simultaneous fluorescence imaging in various cell lines. Importantly, our study provides the first-time valuable insight into the localization of VDPs in whole cells, dynamically visualizing that presence of cell-surface protein vicinal dithiols in MCF-7 cells. Interestingly, some functional cell-surface VDPs have been reported for MCF-7 cells using proteomic analysis. Furthermore, the gradually released fluorescence from RhQ after its interaction with VDPs provides an overall picture of the cellular protein vicinal dithiol profile for different cell lines. This technology shows great promise as a visualization tool for revealing the role of cellular protein vicinal dithiols, especially VDPs on the cell-surface, and stimulating the design of VDP related drug candidates and vectors
Nickel Cobalt Oxide-Single Wall Carbon Nanotube Composite Material for Superior Cycling Stability and High-Performance Supercapacitor Application
The electron conductivity of electrode material has always
been
a problem that hinders the practical application of supercapacitor.
In this contribution, we report a facile synthesis of highly conductive
nickel cobalt oxide-single wall carbon nanotube (NiCo<sub>2</sub>O<sub>4</sub>–SWCNT) nanocomposite by controlled hydrolysis process
in ethanol–water mixed solvent. Ultrafine NiCo<sub>2</sub>O<sub>4</sub> nanocrystals with a diameter around 6–10 nm are formed
on the functionalized SWCNT bundles. This novel material not only
exhibits a high specific capacitance of 1642 F g<sup>–1</sup> within a 0.45 V potential range but also shows an excellent cycling
stability of 94.1% retention after 2000 cycles at high mass loading.
Our method provides a promising facile and high-performance strategy
for supercapacitor electrode application
Selective and Ratiometric Fluorescent Trapping and Quantification of Protein Vicinal Dithiols and in Situ Dynamic Tracing in Living Cells
Protein
vicinal dithiols play fundamental roles in intracellular
redox homeostasis due to their involvement in protein synthesis and
function through the reversible vicinal dithiol oxidation to disulfide.
To provide quantitative information about the global distribution
and dynamic changes of protein vicinal dithiols in living cells, we
have designed and synthesized a ratiometric fluorescent probe (<b>VTAF</b>) for trapping of vicinal dithiol-containing proteins
(VDPs) in living cells. <b>VTAF</b> exhibits a ratiometric fluorescence
signal upon single excitation, which enables self-calibration of the
fluorescence signal and quantification of endogenous vicinal dithiols
of VDPs. Its potential for in situ dynamic tracing of changes of protein
vicinal dithiols under different cellular redox conditions was exemplified. <b>VTAF</b> facilitated the direct observation of subcellular distribution
of endogenous VDPs via ratiometric fluorescence imaging and colocalization
assay. And the results suggested that there are abundant VDPs in mitochondria.
Moreover, some redox-sensitive VDPs are also present on cell surface
which can respond to redox stimulus. This ratiometric fluorescence
technique presents an important extension to previous fluorescence
intensity-based probes for trapping and quantifying protein vicinal
dithiols in living cells, as well as its visible dynamic tracing of
VDPs
Sensitive Detection of Polycyclic Aromatic Molecules: Surface Enhanced Raman Scattering via π–π Stacking
We report silver nanoparticles (Ag
NPs) with high stability, sensitivity,
and no surface enhanced Raman scattering (SERS) background. The Ag
NPs were synthesized via a one-step process with polysodium styrenesulfonate
(PSSS) templates, and they could efficiently adsorb polycyclic aromatic
molecules via π–π stacking. The adsorption mechanisms
and applicability were systematically studied by experimental measurements
and theoretical simulations. When the polycyclic aromatic analytes
were adsorbed on the PSSS-templated Ag NPs, the vibrations of π–π
stacking-bound moieties were attenuated, yet those of the other unbound
aromatic moieties increased. Most importantly, when the analytes had
more than two π–π stacking binding sites, the PSSS-templated
Ag NPs could trap the analytes by focusing through the optical force
induced or via the simultaneously formed analyte–Ag NPs aggregates.
This afforded high SERS intensity and very low detection limits