Presence Of PA Research Articles

Tuning of the properties of polyvinyl alcohol/ polyacrylamide film by phytic acid and gamma radiation crosslinking for food packaging applications

ABSTRACT Polyvinyl alcohol/polyacrylamide/phytic acid (PVA/PAAm/PA) film was prepared using gamma radiation. The strength, tensile stress, and elongation of PVA/PAAm/PA are higher than PVA/PAAm. The contact angle was enhanced in the presence of PA and by increasing the irradiation dose. PVA/PAAm/PA film has antimicrobial activity against gram-positive and gram-negative bacteria. Solubility and water uptake highly decreased by incorporating PA and were supported by exposure to gamma irradiation. A completely insoluble (PVA/PAAm/PA) film was obtained at 20 kGy. The results revealed that the synergistic effect of PA and gamma radiation in enhancing the properties of the prepared films.

Effect of TX-100 pretreatment on carbon paste electrode for selective sensing of dopamine in presence of paracetamol

Dopamine (DA) is one of the chief neurotransmitters present in the central nervous system of mammals. Therefore detection of DA in presence of various analytes like paracetamol has great importance. In the current work, we are proposing that Triton X-100 (TX-100) pretreated carbon paste electrode (CPE) can be useful to detect the DA selectively in presence of PA. After the pretreatment CPE can detect DA in presence of PA effectively. Cyclic voltammetry was employed to observe the amplified electron transfer reaction between the modified CPE and DA. To understand electron transfer regioselectivity at the TX-100 pretreated CPE, a dual descriptor was used. The prepared electrode showed satisfactory stability when kept under ambient conditions. The proposed approach also showed excellent analytical applicability to identify DA and PA in commercial formulations. The scope of the work is limited to detecting DA in presence of PA. We will consider the other interferes for future works.

A coumarin coupled electron donor-acceptor dyad for cascade detection of aluminium ions and explosive nitroaromatic compounds

A coumarin coupled electron donor–acceptor dyad (HL) has been synthesized and characterized by different conventional techniques. Details spectroscopic investigation has been carried out to understand the photophysical behavior of as-prepared HL. The UV–visible spectral behavior of HL is found to be intramolecular charge transfer in nature and shows broadband, having maxima at 432 nm with a shoulder peak around 348 nm in DMF. The emission spectrum of HL also gives broadband, having maxima located at 480 nm in DMF. Further, HL is employed for the cascade detection of Al3+ ions (ON) and picric acid (PA, OFF) in DMF-H2O (7:3, v/v) media. A colorimetric change from yellow to colorless is observed in the presence of Al3+ ions. A significant fluorescence enhancement is observed due to the well coordination of Al3+ ions with HL. A visual bluish-green color could be seen under 365 nm UV light irradiation, which is also well supported by the color chromaticity diagram. The fluorescence of the HL-Al3+ complex is quenched in the presence of PA among all the tested nitroaromatic compounds. The sensitivity of HL and HL-Al3+ complex towards detection of Al3+ ions and PA can be possible down to 0.638 μM and 0.623 µM, respectively. The developed chemosensor is employed for the practical application for mapping Al3+ ions in the living cell. The performance of HL toward Al3+ ions proved that it could be exploited as a signal tool for environmental and biological samples.

An invisible threat? Aspergillus positive cultures and co-infecting bacteria in airway samples

BackgroundAspergillus fumigatus (Af) infection is associated with poor lung health in chronic suppurative lung diseases but often goes undetected. We hypothesised that inhibition of Af growth by Pseudomonas aeruginosa (Pa) increases the frequency of false-negative Af culture in co-infected people. Using a substantial group of cystic fibrosis (CF) airway samples, we assessed the relationship between Af and bacterial pathogens, additionally comparing fungal culture with next-generation sequencing. MethodsFrequency of co-culture was assessed for 44,554 sputum/BAL cultures, from 1,367 CF patients between the years 2010–2020. In a subgroup, Internal Transcribed Spacer-2 (ITS2) fungal sequencing was used to determine sequencing-positive, culture-negative (S+/C-) rates. ResultsPa+ samples were nearly 40% less likely (P<0.0001) than Pa- samples to culture Af, an effect that was also seen with some other Gram-negative isolates. This impact varied with Pa density and appeared to be moderated by Staphylococcus aureus co-infection. Sequencing identified Af-S+/C- for 40.1% of tested sputa. Samples with Pa had higher rates of Af-S+/C- (49.3%) than those without (35.7%; RR 1.38 [1.02–1.93], P<0.05). Af-S+/C- rate was not changed by other common bacterial infections. Pa did not affect the S+/C- rates of Candida, Exophiala or Scedosporium. ConclusionsPa/ Af co-positive cultures are less common than expected in CF. Our findings suggest an Af-positive culture is less likely in the presence of Pa. Interpretation of negative cultures should be cautious, particularly in Pa-positive samples, and a companion molecular diagnostic could be useful. Further work investigating mechanisms, alternative detection techniques and other chronic suppurative lung diseases is needed.

Nanofibers from hydroxypropyl β-cyclodextrin/pantothenic acid supramolecular complexes: Physicochemical characterization and potential biomedical applications

The electrospinning of nanofibers (NFs) from 2-hydroxypropyl β-cyclodextrin supramolecular inclusion complexes (150% HPβ-CD, w/v) with vitamin B5 (pantothenic acid [PA]) was achieved without using any carrier polymeric matrix. The presence of PA and the formation of the HPβ-CD/PA inclusion complex within the NFs structure were confirmed by SEM, FTIR, XRD, and TGA analysis. SEM images depicted the bead-free uniform NFs and confirmed the incorporation of HPβ-CD/PA NFs did not alter the fiber morphology having an average fiber diameter of 512 ± 24 nm, 328 ± 18 nm, and 150 ± 19 nm, respectively. Fourier transform infrared (FTIR) spectrum indicated inclusion complex from the shifting of the peaks of each component in HPβ-CD/PA NFs, whereas XRD pattern revealed that HPβ-CD/PA NFs was achieved due to the formation of a new amorphous structure. TGA studies showed that the stability of PA after HPβ-CD encapsulation was improved. Molecular docking was used to simulate the positions and interactions of the binding sites of the HPβ-CD/PA inclusion complex. The phase solubility test showed enhanced solubility of PA due to the inclusion complexation; in addition, the stoichiometry of HPβ-CD/PA was determined to be 1:1. The release of PA from HPβ-CD/PA NFs prevented the colonization of Escherichia coli (5.0 ± 0.3%) and Staphylococcus aureus (2.0 ± 0.5%) bacteria to a great extent, as observed in the antibacterial activity results. The cell viability of HCT-116 cells treated with 100 μg/mL of HPβ-CD/PA NFs was registered at 97.5 ± 2.1%. It was observed that HPβ-CD/PA NFs had higher anticancer activity compared to pure PA and HPβ-CD due to the solubility increase. In brief, our results suggested that polymer-free HPβ-CD/PA inclusion complex NFs could have potential applications in food, pharmaceuticals, and healthcare thanks to its efficient antibacterial and anticancer activities.

Effect of mixing structure on the water uptake of mixtures of ammonium sulfate and phthalic acid particles

Abstract. Aerosol mixing state regulates the interactions between water molecules and particles and thus controls aerosol activation and hygroscopic growth, which thereby influences visibility degradation, cloud formation, and its radiative forcing. There are, however, few current studies on the mixing structure effects on aerosol hygroscopicity. Here, we investigated the hygroscopicity of ammonium sulfate / phthalic acid (AS / PA) aerosol particles with different mass fractions of PA in different mixing states in terms of initial particle generation. Firstly, the effect of PA coatings on the hygroscopic behavior of the core-shell-generated mixtures of AS with PA was studied using a coating hygroscopicity tandem differential mobility analyzer (coating HTDMA). The slow increase in the hygroscopic growth factor of core-shell-generated particles is observed with increasing thickness of the coating PA prior to the deliquescence relative humidity (DRH) of AS. At relative humidity (RH) above 80 %, a decrease in the hygroscopic growth factor of particles occurs as the thickness of the PA shell increases, which indicates that the increase of PA mass fractions leads to a reduction of the overall core-shell-generated particle hygroscopicity. In addition, the use of the Zdanovskii–Stokes–Robinson (ZSR) relation leads to the underestimation of the measured growth factors of core-shell-generated particles without consideration of the morphological effect of core-shell-generated particles, especially at higher RH. Secondly, in the case of the AS / PA initially well-mixed particles, a shift of the DRH of AS (∼80 %, Tang and Munkelwitz, 1994) to lower RH is observed due to the presence of PA in the initially well-mixed particles. The predicted hygroscopic growth factor using the ZSR relation is consistent with the measured hygroscopic growth factor of the initially well-mixed particles. Moreover, we compared and discussed the influence of mixing states on the water uptake of AS / PA aerosol particles. It is found that the hygroscopic growth factor of the core-shell-generated particles is slightly higher than that of the initially well-mixed particles with the same mass fractions of PA at RH above 80 %. The observation of AS / PA particles may contribute to a growing field of knowledge regarding the influence of coating properties and mixing structure on water uptake.

Bark extract of Cassia sieberiana DC. (Caesalpiniaceae) displayed good antibacterial activity against MDR gram-negative phenotypes in the presence of phenylalanine-arginine \u03b2-naphthylamide

BackgroundMultidrug-resistant (MDR) bacteria remain a major cause of morbidity and mortality globally. The present study was designed to investigate the in vitro antibacterial activities of crude methanol extract and constituents isolated by Column Chromatography (CC) from Cassia sieberiana bark (CSB) against ten MDR Gram-negative bacteria, as well as the mechanisms of action of the most active sample.MethodsThe antibacterial activity of the tested samples (extract, the fractions and their compounds isolated by CC and the structures obtained by exploiting 1H and 13C Nuclear magnetic resonance (NMR) spectra) in the presence and absence of an efflux pumps inhibitor, phenylalanine-arginine β-naphthylamide (PAβN), was evaluated using the micro-dilution method. The effects of the most active sample were evaluated on the cell growth kinetic and on the bacterial H+-ATPase proton pumps.ResultsPhytochemical composition of the crude extract showed a rather selective distribution of secondary metabolites (presence of polyphenols, tannins, steroids, triterpenes, flavonoids, alkaloids, saponins and absence of anthocyanins, anthraquinones). The tested samples displayed different antibacterial activities with minimal inhibitory concentrations (MICs) ranging from 64 to 512 μg/mL. Crude extract (CS) and fraction CSc showed the highest inhibitory spectra, both inhibiting all of the studied bacteria except Enterobacter aerogenes EA27 strain. Fraction CSc exerted bactericidal effects on most bacteria meanwhile, crude extract (CS) and sub-fraction CSc2 exerted bacteriostatic effects. Compounds 1 (spectaline) and 2 (iso-6-cassine) inhibited the growth of 70% (Escherichia coli ATCC8739 and AG102, Klebsiella pneumoniae ATCC11296, Enterobacter aerogenes ATCC13048 and EA27, Providencia stuartii ATCC29916, Pseudomonas aeruginosa PA01) and 60% (Escherichia coli ATCC8739, Klebsiella pneumoniae ATCC11296 and KP55, Providencia stuartii ATCC29916, Pseudomonas aeruginosa PA01 and PA124) of bacteria respectively with MICs ranging from 128 to 512 μg/mL. In the presence of PAβN, the activities of crude extract CS, fraction CAc and sub-fraction CSc2 strongly increased on most bacteria strains as their MICs significantly decreased. Sub-fraction CSc2 inhibited the H+-ATPase proton pumps and altered growth kinetic of Escherichia coli ATCC8739.ConclusionThe overall results justify the traditional use of C. sieberiana for the treatment of bacterial infections.

Synthesis, characterization and chemical sensor applications of pyrene side‐functional polylactide copolymers

AbstractA novel polylactide (PLA) polymer containing pyrene side groups (P2) was synthesized and employed as a nitroaromatic compound (NAC) and heavy metal ion (HMI) sensing chemical probe. P2 was prepared in a four‐step reaction sequence, including azidification, esterification, ring opening polymerization and click reactions. First, an azido functional cyclic carbonate monomer (ADTC) was synthesized and then a copolymer of l‐lactide and ADTC monomers was synthesized to obtain PLA with azido functional groups (P(LA‐co‐ADTC), P1). Finally, P1 was modified with pyrene groups using ‘click chemistry’ which is a highly effective modification method (P2). The chemical structures and molecular characteristics of the obtained polymers were clearly verified via Fourier transform infrared spectroscopy, gel permeation chromatography and 1H NMR analysis techniques and the fluorescence properties were examined via UV–visible and fluorescence spectrometry. The prepared P2 polymers were employed as a fluorescent probe towards certain HMI (Zn2+, Hg2+, Mn2+, Pb2+, Cd2+, Co2+) compounds and NACs (1,2‐dinitrobenzene, 2,4‐dinitrotoluene, 2,4,6‐trinitrophenol (picric acid, PA), 4‐nitrophenol (4‐NP), 2,4‐dinitrophenol (2,4‐DNP), 2,4,6‐trinitrotoluene, 4‐nitrotoluene). The fluorescence intensity of the P2 polymers was gradually reduced upon the addition of NACs and HMIs. For all compounds, the highest quenching efficiencies were attained in the presence of PA (94.03%), 4‐NP (91.11%) and 2,4‐DNP (89.08%). Because of its simplicity and sensitivity, the proposed P2 polymers can be especially considered as potential chemical probes to detect NACs. © 2020 Society of Industrial Chemistry

Biphasic polylactide/polyamide 6,10 blends: Influence of composition on polyamide structure and polyester crystallization

Blends with different ratios of polylactide and polyamide 6,10 (PA610) have been prepared by melt-mixing using a Brabender mixer equipment. Previously, a rheologically modified polylactide (PLAREx) was obtained through reactive extrusion using a multifunctional epoxide agent. It was expected that unreacted epoxy groups of PLAREx were able to improve the compatibility between the two polymers. SEM observations revealed a logical dependence of the morphology of immiscible phases with composition, and more interestingly a co-continuity at relatively low PA content (around 50%) was detected. This result contrasts with previous observations performed with non-modified PLA.Confined PA domains increased with the PA content and hardly crystallized at the typical crystallization temperature of the pure PA (195 °C). Synchrotron X-ray diffraction studies indicated that a PA crystallization at a lower temperature close to 120 °C was enhanced and led to a pseudohexagonal γ phase that differs from the characteristic layered structure of PA610. SAXS data revealed also that well differentiated lamellar entities could be assigned at both immiscible polymer phases. Clear differences were observed in the spherulitic morphologies attained under isothermal melt crystallization experiments. Results indicated that the texture of PLAREx spherulites was modified by the presence of PA. Compatibilization of PA molecules on the crystal lamellar boundaries of PLAREx led to an enhancement of the lamellar twisting frequency. Optical microscopy results also indicated that the crystal growth rate of PLAREx increased by the incorporation of PA, but in contrast this had an adverse effect on the nucleation process.

Globular CTRP9 protects cardiomyocytes from palmitic acid-induced oxidative stress by enhancing autophagic flux

BackgroundOxidative stress in cardiac myocytes is an important pathogenesis of cardiac lipotoxicity. Autophagy is a cellular self-digestion process that can selectively remove damaged organelles under oxidative stress, and thus presents a potential therapeutic target against cardiac lipotoxicity. Globular CTRP9 (gCTRP9) is a newly identified adiponectin paralog with established metabolic regulatory properties. The aim of this work is to investigate whether autophagy participates the protection effects of gCTRP9 in neonatal rat cardiac myocytes (NRCMs) under oxidative stress and the underlying mechanism. ResultsNRCMs were treated with PA of various concentrations for indicated time period. Our results showed that PA enhanced intracellular ROS accumulation, decreased mitochondrial membrane potential (Δψm) and increased activation of caspases 3. These changes suggested lipotoxicity due to excessive PA. In addition, PA was observed to impair autophagic flux in NRCMs and impaired autophagosome clearance induced by PA contributes to cardiomyocyte death. Besides, we found that gCTRP9 increased the ratio of LC3II/I and the expression of ATG5 which was vital to the formation of autophagosomes and decreased the level of P62, suggesting enhanced autophagic flux in the absence or presence of PA. The result was further confirmed by the methods of infection with LC3-mRFP-GFP lentivirus and blockage of autophagosome–lysosome fusion by BafA1. Moreover, gCTRP9 reestablished the loss of mitochondrial membrane potential, suppressed ROS generation, and reduced PA -induced myocyte death. However, the protective effect of gCTRP9 on the cardiac lipotoxicity was partly abolished by blockade of autophagy by autophagy-related 5 (ATG5) siRNA, indicating that the effect of gCTRP9 on cell survival is critically mediated through regulation of autophagy. ConclusionAutophagy induction by gCTRP9 could be utilized as a potential therapeutic strategy against oxidative stress-mediated damage in cardiomyocytes.

Broad spectrum resistance in Helicobacter pylori isolated from gastric biopsies of patients with dyspepsia in Cameroon and efflux-mediated multiresistance detection in MDR isolates

BackgroundAntibiotic resistance is a leading cause of treatment failure in Helicobacter pylori infection. In Africa, there are very little data concerning the susceptibility of Helicobacter pylori isolates to antibiotics. The purpose of this study was to evaluate the resistance prevalence of Helicobacter pylori strains circulating in Cameroon, and to assess overexpression of efflux pump as a possible multi-drug resistance mechanisms.MethodsA total of 140 H. pylori isolates were recovered from gastric biopsies of dyspeptic patients in two reference hospitals in Cameroon and analyzed for their antimicrobial susceptibility to amoxicillin, co-amoxiclav, ampicillin, penicillin, imipenem, metronidazole, rifabutin, erythromycin, clarithromycin, azithromycin, levofloxacin, ciprofloxacin, norfloxacin, tetracycline, doxycycline and minocycline. Antibiotic sensitivity was tested by disk diffusion method. Phe-Arg-naphthylamide (PAßN) was used as efflux pump inhibitor. INT broth microdilution method in supplemented Brain Heart Infusion broth was used to determine the MIC of ampicillin, amoxicillin, metronidazole, erythromycin, clarithromycin and doxycycline in the absence and the presence of PAßN against 32 selected MDR isolates.ResultsOverall H. pylori resistance rate was 100% to ampicillin, penicillin and co-amoxiclav; 97.14% to amoxicillin, 97.85% to metronidazole, 47.85% to erythromycin, 13.57% to clarithromycin; 5, 2.86 and 0.71% to doxycycline, tetracycline and minocycline respectively. No resistance to azithromycin, rifabutin, imipenem, ciprofloxacin, norfloxacin and levofloxacin was detected among H. pylori isolates. Seventy percent (70%) of the tested isolates elicited a multiple drugs resistance pattern; 42.57% double, 15.71% triple and 5.71% quadruple drugs resistance. Metronidazole and amoxicillin were more concerned with double resistance pattern (86.76%). The spectrum of activity recorded with metronidazole, doxycycline, clarithromycin and erythromycin ranged from 0 to 100% in the absence to the presence of PAßN against the tested MDR isolates. An 8 to 128-fold increase in potency was also noticed with these antibiotics in the presence of PAßN.ConclusionWith regard to the high resistance rate to both amoxicillin and metronidazole, these drugs should be avoided as components of triple therapy in our milieu. In contrast, ciprofloxacin, norfloxacin, levofloxacin and tetracyclines could be used to achieve a better eradication rate and to reduce the risk of selection of H. pylori resistant strains.

Highly selective fluorescent chemosensor for the relay detection of Al3+ and picric acid

A visible “off-on-off” fluorescent chemosensor N′,N′-bis(-(2-hydroxynaphthalen-1-yl)methylene)-1,10-phenanthroline-2,9-dicarbohydrazide (L, OFF) was developed for the sequential detection of Al3+ (ON) and picric acid (PA, OFF) in DMSO-H2O (7:3, v/v) media. The sensor (L) form a 1:2 complex with Al3+ (L-Al3+) which resulted in the significant fluorescence enhancement at 544 nm due to the chelation enhanced fluorescence (CHEF) effect. The fluorescence of L-Al3+ complex was quenched in the presence of PA by quenching mode and magnitude of quenching constant was 6.45 × 107 M−1. The sensitivity L and L-Al3+ towards the detection of Al3+ and PA can be possible down to 1.91 nM and 96.3 nM, respectively. The coordination modes of the sensor were further studied by various spectroscopic techniques such as 1H NMR, mass and DFT studies. The developed sensor was applied for the practical application, determining Al3+ in pharmaceutical and water samples.

Palmitic Acid Induces Extracellular Vesicle Release in Human Renal Proximal Tubule Epithelial Cells

Lipotoxicity, an accumulation of intracellular lipid metabolites, has been proposed as an important pathogenic mechanism leading to kidney dysfunction in the context of metabolic disease. Palmitate, a predominant lipid derivative, can cause lipoapoptosis and the release of inflammatory extracellular vesicles (EVs) in hepatocytes. This study was aimed to investigate whether free fatty acid palmitate could increase EV release in renal tubular epithelial cells. A human proximal tubule epithelial cell line, HK‐2, was incubated with 1% bovine serum albumin (BSA), BSA‐conjugated palmitic acid (PA, 250 μM), BSA‐conjugated oleic acid (OA, 250 μM), or diluent (control) for 24 hours. The released EVs were isolated by ultracentrifugation, then characterized and quantified by immunoblot and nanoparticle‐tracking analysis (NTA). To examine the uptake of EVs by tubular cells, isolated EVs were further labelled and applied to HK‐2 cells. According to the NTA, the size distribution of HK‐2‐derived EVs was 30–200 nm with a similar mode size in all four groups. Interestingly, incubation of HK‐2 cells with 1%BSA alone significantly increased the release of EVs compared to the vehicle control. Moreover, BSA‐induced EV release was further increased by approximately two‐fold in the presence of PA, whereas EV production was not significantly changed by the addition of OA. PA (250 μM)‐enhanced EV release in HK‐2 is independent of cell apoptosis since apoptosis‐related proteins were not different between BSA and BSA‐PA groups. Both confocal microscopy and flow cytometry analyses confirmed that labeled lipid‐induced EVs were taken up by HK‐2 cells. Collectively, our results indicate that saturated fatty acid palmitate stimulates EV release from HK‐2 cells. Lipid‐induced EVs may serve as an untapped source to evaluate novel signaling pathways contributing to nephropathy progression.Support or Funding InformationNIH Diabetes and Digestive Kidney Disease Grant Number: R25DK1136559MSM Interdisciplinary Sleep/Clinical Cardiovascular Research Training Program (T32)This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Selective separation of yttrium(III) through a liquid membrane system using 2-thenoyltrifluoroacetone as an extractant carrier

2-Thenoyltrifluoroacetone has been offered as a mobile carrier in organic phase for the transport and selective separation of yttrium from aqueous media using a liquid membrane system. Perceivably, the use of n-propylamine (PA) in the source phase enhances the transport of yttrium ions. The extraction and stripping conditions have entirely been evaluated and explained. The suggested method has been utilized for the separation of yttrium(III) from its binary mixtures with strontium(II) and some other cations such as Ni2+, Co2+, Ag+, Fe2+, Al3+, Cu2+, Hg2+and Cs+ in aqueous solutions of pH 5.4 in the presence of PA, while 1 M nitric acid was acting as a stripping agent in the receiving division. Cyanide ion and 5-sulfosalicylic acid have been used as masking agents to minimize the interferences from different transition metal ions and Al3+ in the source phase, respectively. 90Y in secular equilibrium with 90Sr in the source phase, was transferred to receiving phase and separated completely from its long-lived parent isotope. The activity of the transported 90Y was found to decay with a half-life 64.17 ± 0.05 h. The purity of yttrium-90 was comparable or better than the other applied liquid membrane systems for purification of yttrium-90.

Chemiluminescence and reactivity of the composites based on blends of polypropylene and polyamide

The effect of the composition of blends based on isotactic polypropylene (PP) and aliphatic polyamide 6/66-4 (PA) on the rate of photo-oxidation of their mixtures in air at room temperature has been studied. The decay of photoinduced chemiluminescence was studied to determine the kinetics of peroxyl radical termination in composites and the rate constants of this process depending on the composition of the mixtures. In the presence of PA, the rate of photo-oxidation of mixtures is much higher than the rates of photo-oxidation of separately taken components, PP and PA. Thus, the kinetics of photo-oxidation of mixtures differs from the simple sum of photo-oxidation kinetics of PP and PA, which should be expected in the absence of chemical and physical interaction of the components of the mixture. A decrease in the rate constants due to PA additives indicates a decrease in the mobility of molecules in the composites and explains the observed increase in photo-oxidation of mixtures.

GLP-1 Analogue, Exendin-4, Modulates MAPKs Activity but not the Heat Shock Response in Human HepG2 Cells.

Glucagon-like peptide-1 (GLP-1) analogues reduce ER stress and inflammation in key metabolic organs, including the liver. However, their effects on heat shock response (HSR) and mitogen-activated protein kinases (MAPKs) have not yet been elucidated. In the present study, we investigate whether the GLP-1 analogue, exendin-4, triggers the expression of HSR and increases MAPK activity under metabolic stress. The effects of exendin-4 in the presence or absence of palmitic acid (PA; 400 μm) or glucose (30 mm) in the HepG2 liver cell line are assessed using Western blots, quantitative real-time PCR, and label-free proteomics. Heat shock proteins (HSP60, HSP72, HSP90, and GRP78) and other chaperones are not significantly affected by exendin-4 under the conditions tested. In contrast, the presence of exendin-4 alone increases the MAPK phosphorylation levels (JNK, ERK1/2, and p38). For short incubation periods, in the presence of PA or glucose, treatment with exendin-4 exhibits limited effects but significantly attenuates MAPK phosphorylation after a 24-h incubation. Interestingly, canonical signaling pathways, such as EIF2, ILK, PKA, and Rho, are modulated by exendin-4. Identifying new pathways modulated by GLP-1 analogues will provide further insights into their benefits beyond their currently recognized roles in glycemic control, such as MAPK activity, energy homeostasis, and body weight decrease.

Development of o-phthalic anhydride as a low-temperature activator in H2O2 bleaching system for cotton fabric

O-phthalic anhydride (PA) was developed as a low-temperature activator in the H2O2 bleaching system for cotton fabric. The performance of the H2O2/PA bleaching system was investigated by measuring the CIE whiteness index (WI) of the bleached cotton fabric, H2O2 decomposition rate and bursting strength, respectively. The effects of experimental conditions, including PA dosage, bleaching time, bleaching temperature and NaOH concentration, were discussed in the H2O2/PA bleaching system. Upon addition of PA, the WI and H2O2 decomposition rate increased significantly at 70 °C. The results showed that the bleaching system had a promising application prospect. Compared with the H2O2 system, the H2O2/PA system significantly promoted 1O2 generation under the same alkali condition by using 9,10-dimethylanthracene as a fluorescent probe for 1O2. And the generation of large amount of 1O2 did not obviously affect the bleaching performance in the H2O2/PA system. By using benzenepentacarboxylic acid as a fluorescent probe for HO· detection, it was found that the fluorescence intensity was enhanced 14 folds in the presence of PA, indicating that PA could strongly promote HO· generation. By using dimethyl sulfoxide as a scavenger to control HO· concentration, it was found that the WI of the fabric was closely related to the HO· concentration, revealing that the HO· could play an important role in the bleaching process. Phthalic acid was also added to the H2O2 bleaching system to investigate potential bleaching route of the H2O2/PA system. Based on these experimental results, a possible bleaching mechanism of the H2O2/PA system was proposed.

Gas Chromatographic Separation and Identification of Jacaric and Punicic 2‐Ethyl‐1‐Hexyl Esters

AbstractThe present study demonstrates the separation of a critical pair of conjugated linolenic acid (CLN) isomers—jacaric acid (JA; c8, t10, c12‐18:3) and punicic acid (PA; c9, t11, c13‐18:3)—on a 60‐m conventional Supelcowax 10 column. The alkyl esters of different alcohols (C1–C8) of JA and PA were prepared and analyzed isothermally at 220, 230 and 240 °C. The adequacy of their separation was determined from the separation factors (α) and peak resolutions (Rs). Acceptable resolution (Rs = 1.01) of JA and PA was obtained with their 2‐ethyl‐1‐hexyl ester derivatives at a column temperature of 230 °C. In addition, the Gibbs energy of transfer from solution to gas of the three double bonds ) could be used to describe the interactions of the double bond with the stationary phase. Characterization of 2‐ethyl‐1‐hexyl esters of Jacaranda mimosifolia seed oil at 230 °C demonstrates that the oil contains JA and α‐ and β‐calendic acid as a CLN without the presence of PA. The results suggested that JA could be resolved from PA on a 60‐m Supelcowax 10 column as the ethyl hexyl ester.

Preparation and Antiproliferative Activity of Liposomes Containing a Combination of Cisplatin and Procainamide Hydrochloride.

We have previously reported the enhancement of the antiproliferative and apoptotic activities of cis-diamminedichloroplatinum(II) (DDP) when it is coadministered with a class I antiarrhythmic drug procainamide hydrochloride (PA). Here, we determined the antiproliferative activity of DDP, either in solution or loaded in liposomes, in the presence of PA, in the bulk solution, or directly embedded in liposomes together with DDP. Our results show that PA potentiates the activity of DDP-liposomes and that this effect is maintained at least in some of the investigated cell types when both drugs were mixed and loaded together into liposomes.

The secretion of the bacterial phytase PHY-US417 by Arabidopsis roots reveals its potential for increasing phosphate acquisition and biomass production during co-growth.

SummaryPhytic acid (PA) is a major source of inorganic phosphate (Pi) in the soil; however, the plant lacks the capacity to utilize it for Pi nutrition and growth. Microbial phytases constitute a group of enzymes that are able to remobilize Pi from PA. Thus, the use of these phytases to increase the capacity of higher plants to remobilize Pi from PA is of agronomical interest. In the current study, we generate transgenic Arabidopsis lines (ePHY) overexpressing an extracellular form of the phytase PHY‐US417 of Bacillus subtilis, which are characterized by high levels of secreted phytase activity. In the presence of PA as sole source of Pi, while the wild‐type plants show hallmark of Pi deficiency phenotypes, including the induction of the expression of Pi starvation‐induced genes (PSI, e.g. PHT1;4) and the inhibition of growth capacity, the ePHY overexpressing lines show a higher biomass production and no PSI induction. Interestingly, when co‐cultured with ePHY overexpressors, wild‐type Arabidopsis plants (or tobacco) show repression of the PSI genes, improvement of Pi content and increases in biomass production. In line with these results, mutants in the high‐affinity Pi transporters, namely pht1;1 and pht1;1‐1;4, both fail to accumulate Pi and to grow when co‐cultured with ePHY overexpressors. Taken together, these data demonstrate the potential of secreted phytases in improving the Pi content and enhancing growth of not only the transgenic lines but also the neighbouring plants.