REFRACTOMETRY AND TEXTURES OF METHYL-CYANOETHYL CELLULOSE/DICHLOROACETIC ACID LIQUID CRYSTA LLI NE SOLUTIONS^+

An Abbe refractometer with a rotatable polarizer mounted on the eyepiece is used for determining the two principal refractive indices of methyl-cyanoethyl cellulose/dichloroacetic acid liquid crystalline solutions. The critical concentration where the mesophase appears can be determined according to the variation of the increment of the refractive index with the concentration. Mesophase textures of the liquid crystalline solutions are observed and the influence of the concentration on mesophase textures is also discussed.

Treatment Process for the Low Residual of Dichloroacetic Acid in Lauramidopropyl Betaine

Without using sodium sulfite or oxides,The content of residual dichloroacetic acid in lauramidopropyl betaine was reduced by technology improvement.The effects of reaction temperature,pressure,reaction time,pH and color on the residual dichloroacetic acid were studied.The optimum conditions were screened out,i.e.processing time of 3 h,processing temperature of 120℃,pressure of 0.11 MPa and pH of 12.0.Hereby the dichloroacetic acid residues could be reduced from 450 mg/kg to less than 50 mg/kg,and the color of the product was below 70 hazen.

Dichloroacetic acid and rapamycin synergistically inhibit tumor progression

Mammalian target of rapamycin(mTOR)controls cellular anabolism,and mTOR signaling is hyperactive in most cancer cells.As a result,inhibition of mTOR signaling benefits cancer patients.Rapamycin is a US Food and Drug Administration(FDA)-approved drug,a specific mTOR complex 1(mTORC1)inhibitor,for the treatment of several different types of cancer.However,rapamycin is reported to inhibit cancer growth rather than induce apoptosis.Pyruvate dehydrogenase complex(PDHc)is the gatekeeper for mitochondrial pyruvate oxidation.PDHc inactivation has been observed in a number of cancer cells,and this alteration protects cancer cells from senescence and nicotinamide adenine dinucleotide(NAD^(+))exhaustion.In this paper,we describe our finding that rapamycin treatment promotes pyruvate dehydrogenase E1 subunit alpha 1(PDHA1)phosphorylation and leads to PDHc inactivation dependent on mTOR signaling inhibition in cells.This inactivation reduces the sensitivity of cancer cells'response to rapamycin.As a result,rebooting PDHc activity with dichloroacetic acid(DCA),a pyruvate dehydrogenase kinase(PDK)inhibitor,promotes cancer cells'susceptibility to rapamycin treatment in vitro and in vivo.

Enhanced ozonation of dichloroacetic acid in aqueous solution using nanometer ZnO powders

Nanometer zinc oxide （ZnO） powders were used as a catalyst to enhance the ozonation for the degradation of dichloroacetic acid （DCAA） in aqueous solution. The batch experiments were carded out to investigate the effects of key factors such as catalyst dosage, ozone dosage, solution pH and tert-butyl alcohol （t-BuOH） on the degradation efficiency of DCAA. Density functional theory （DFT） was adopted to explore the mechanism of generating hydroxyl radical （＇OH） on the ZnO surface. The results showed that adsorption and ozonation processes were not effective for DCAA removal, and the addition of ZnO catalyst improved the degradation efficiency of DCAA during ozonation, which caused an increase of 22.8% for DCAA decomposition compared to the case of ozonation alone after 25 min. Under the same experimental conditions, the DCAA decomposition was enhanced by increasing catalyst dosage from 100 to 500 mg/L and ozone dosage from 0.83 to 3.2 mg/L. The catalytic ozonation process is more pronounced than the ozonation process alone at pH 3.93, 6.88, and 10. With increasing the concentration of t-BuOH from 10 to 200 rag/L, the degradation of DCAA was significantly inhibited in the process of catalytic ozonation, indicating that ZnO catalytic ozonation followed ＂OH reaction mechanism. Based on the experimental results and DFT analysis, it is deduced that the generation of ＂OH on the ZnO surface is ascribed to the adsorption of molecule ozone followed by the interaction of adsorbed ozone with active sites of the catalyst surface. It is also concluded that ZnO may be an effective catalyst for DCAA removal, which could promote the formation of .OH derived from the catalytic decomposition of ozone.

Preparation and characterization of Pd/Fe bimetallic nanoparticles immobilized on Al_2O_3/PVDF membrane:Parameter optimization and dechlorination of dichloroacetic acid

Using a liquid-solid phase inversion method, a hybrid matrix poly（vinylidene fluoride）（PVDF） membrane was prepared with alumina（Al2O3） nanoparticle addition. Pd/Fe nanoparticles（NPs） were successfully immobilized on the Al2O3/PVDF membrane, which was characterized by Scanning Electron Microscopy（SEM） and Transmission Electron Microscopy（TEM）. The micrographs showed that the Pd/Fe NPs were dispersed homogeneously. Several important experimental parameters were optimized, including the mechanical properties, contact angle and surface area of Al2O3/PVDF composite membranes with different Al2O3 contents. At the same time, the ferrous ion concentration and the effect of hydrophilization were studied. The results showed that the modified Al2O3/PVDF membrane functioned well as a support. The Al2O3/PVDF membrane with immobilized Pd/Fe NPs exhibited high efficiency in terms of dichloroacetic acid（DCAA） dechlorination. Additionally, a reaction pathway for DCAA dechlorination by Pd/Fe NPs immobilized on the Al2O3/PVDF membrane system was proposed.

Cocrystallization-like strategy for the codelivery of hydrophobic and hydrophilic drugs in a single carrier material formulation

Codelivery of drugs by drug carriers is a promising strategy against several diseases such as infections and cancer.However,traditional drug carriers are typically characterized by low drug payload,limiting their treatment efficacy.Using nanocrystals of insoluble drug as carriers,a carrier free platform was developed previously to deliver a second insoluble drug for codelivery.To extend the concept,we hypothesized,herein,that the platform allows for codelivery of hydrophobic and hydrophilic drugs using a cocrystalization-like strategy.To obtain proof-of-concept,paclitaxel(PTX),an insoluble chemotherapeutic agent,and dichloroacetic acid(DCA),a water-soluble inhibitor of pyruvate dehydrogenase kinase,were utilized as model drugs.PTX-DCA hybrid nanocrystals(PTX-DCA NCs)were prepared by antisolvent precipitation and characterized.Their in vitro antitumor activity against cancer cells was evaluated.PTX-DCA NCs prepared from the optimized formulation had a diameter of 160 nm and a rodshape morphology and possessed encapsulated efficacy of approximately 30%for DCA.The use of the hybrid crystals enabled synergy to kill cancer cells,in particular in PTX-resistant cells in a dosedependent pattern.In conclusion,by using a cocrystalization-like strategy,a hydrophilic drug can be formulated into a drug’s nanocrystal for codelivery.