Disruption of Microtubules Sensitizes the DNA Damage-induced Apoptosis Through Inhibiting Nuclear Factor κB (NF-κB) DNA-binding Activity

The massive reorganization of microtubule network involves in transcriptional regulation of several genes by controlling transcriptional factor, nuclear factor-kappa B (NF-κB) activity. The exact molecular mechanism by which microtubule rearrangement leads to NF-κB activation largely remains to be identified. However microtubule disrupting agents may possibly act in synergy or antagonism against apoptotic cell death in response to conventional chemotherapy targeting DNA damage such as adriamycin or comptothecin in cancer cells. Interestingly pretreatment of microtubule disrupting agents (colchicine, vinblastine and nocodazole) was observed to lead to paradoxical suppression of DNA damage-induced NF-κB binding activity, even though these could enhance NF-κB signaling in the absence of other stimuli. Moreover this suppressed NF-κB binding activity subsequently resulted in synergic apoptotic response, as evident by the combination with Adr and low doses of microtubule disrupting agents was able to potentiate the cytotoxic action through caspase-dependent pathway. Taken together, these results suggested that inhibition of microtubule network chemosensitizes the cancer cells to die by apoptosis through suppressing NF-κB DNA binding activity. Therefore, our study provided a possible anti-cancer mechanism of microtubule disrupting agent to overcome resistance against to chemotherapy such as DNA damaging agent

A Kinetic Study on Enhanced Cementation of Gold Ions by Galvanic Interactions between Aluminum (Al) as an Electron Donor and Activated Carbon (AC) as an Electron Mediator in Ammonium Thiosulfate System

The enhanced cementation technique by galvanic interaction of aluminum (Al; electron donor) and activated carbon (AC; electron mediator) to recover gold (Au) ions from the ammonium thiosulfate solution is a promising technique to eliminate the challenges of poor recovery in the system. This study presents the kinetics of Au ion cementation in an ammonium thiosulfate lixiviant as functions of initial Au concentration, size/amount of Al and AC, temperature, and shaking speed. The recovery results basically followed first order kinetics and showed that the cementation rate increased with a higher initial concentration of Au, smaller electron donor size, greater both electron donor and mediator quantity, decrease in temperature, and higher shaking speed in the system, while size of electron mediator did not significantly affect Au recovery

Laser-Induced Graphitization of Cellulose Nanofiber Substrates under Ambient Conditions

A CO2 laser engraver was used to synthesize conductive graphitic carbon directly on cellulose nanofiber (CNF) substrates under ambient conditions. CNFs were prepared via a TEMPO (2,2,6,6-tetramethylpiperidin-1-oxyl radical)-mediated oxidation reaction of bleached pulp, and a porous paper or a transparent film was obtained based on the drying conditions employed. Laser irradiation on a porous CNF paper led to the formation of amorphous carbon owing to an increase in temperature. Subsequent lasing converted the amorphous carbon to conductive graphitic carbon. The conductivity of this carbon increased from 3 mu S/cm to 60 mS/cm as the number of irradiations increased from one to four. Although the CNF paper was converted to graphitic carbon by means of multiple lasing, graphitic carbon was obtained for the CNF film by a single run of lasing owing to its very low oxygen permeability. The conversion of the CNF substrates to graphitic carbon under ambient conditions was attributed to the presence of sodium in CNFs. A control experiment using a CNF in which sodium was replaced with hydrogen demonstrated that only amorphous carbon was produced by laser exposure.11Nsciescopu

Merit Principles Merit Further Investigation: The Influence on Employee Perception of Whistleblowing

Merit principles have been fundamental to managing human resources for several decades in public administration. However, the meaning of merit and its relationship with other values needs more attention from the scholarship. This study investigates how three components of merit principles, i.e., tenure protection, merit-based hiring, and merit-based rewards, affect government employees in different ways by focusing on their willingness to report wrongdoings. This study finds from the Federal Employee Viewpoint Survey that tenure protection is a significant positive predictor of whistleblowing, and its negative marginal effect turns to positive when employees perceive their tenures are well protected. However, their willingness to blow the whistle is less related to merit-based hiring, while merit-based rewards have a positive effect on whistleblowing despite the ambiguous expectation in the literature. Employee empowerment, trust in management, and ethical leadership consistently increase the probability of whistleblowing. This study finds no evidence of interagency differences

Enhanced sensitivity of lateral flow immunoassays by using water-soluble nanofibers and silver-enhancement reactions

We developed a facile method for enhancing the sensitivity of lateral flow immunoassays (LFIAs) using core-shell hybrid nanofibers comprising a water-soluble polymer in the shell and silver-reducing reagents in the core. These nanofibers were produced using a coaxial electrospinning method and directly deposited in front of the test line on a nitrocellulose (NC) membrane. When a human serum spiked with various concentrations of Troponin I (TnI), a cardiac biomarker, was dropped on the absorption pad, a color change was induced by the binding of TnI-gold nanoparticle complexes to the antibodies at the test line. The silver-reducing reagents were subsequently released from the nanofibers via dissolution, which reduced silver ions to metallic silver around the gold nanoparticles and darkened the color of the test line. The hybrid nanofibers enhanced the detection limit of a commercial LFIA by up to 10 times when viewed with the naked eye while maintaining the assay time and convenience characteristics of this analysis.11Nsciescopu