Comparison of Aging Resistance and Antimicrobial Properties of Ethylene-Norbornene Copolymer and Poly(Lactic Acid) Impregnated with Phytochemicals Embodied in Thyme (Thymus vulgaris) and Clove (Syzygium aromaticum).

The effects of plant-based extracts on the solar aging and antimicrobial properties of impregnated ethylene-norbornene (EN) copolymer and poly(lactic acid) (PLA) were investigated. In this study, the impregnation yield of polyolefin, lacking in active centers capable of phytochemical bonding, and polyester, abundant in active sides, was measured. Moreover, two different extracts plentiful in phytochemicals-thyme (TE) and clove (CE)-were employed in the solvent-based impregnation process. The effect of thymol and eugenol, the two main compounds embodied in the extracts, was studied as well. Interestingly, oxidation induction times (OIT) for the impregnation of EN with thyme and clove extracts were established to be, respectively, 27.7 and 39.02 min, which are higher than for thymol (18.4 min) and eugenol (21.1 min). Therefore, an aging experiment, mimicking the full spectrum of sunlight, was carried out to investigate the resistance to common radiation of materials impregnated with antioxidative substances. As expected, the experiment revealed that the natural extracts increased the shelf-life of the polymer matrix by inhibiting the degradation processes. The aging resistance was assessed based on detected changes in the materials' behavior and structure that were examined with Fourier-transform infrared spectroscopy, contact angle measurements, color quantification, tensile tests, and hardness investigation. Such broad results of solar aging regarding materials impregnated with thyme and clove extracts have not been reported to date. Moreover, CE was found to be the most effective modifying agent for enabling material with antimicrobial activity against Escherichia coli to be obtained.

Fe3O4@Void@Microporous Organic Polymer-Based Multifunctional Drug Delivery Systems: Targeting, Imaging, and Magneto-Thermal Behaviors.

Multifunctional drug delivery systems were designed and engineered by template synthesis of a microporous organic polymer (MOP) and by postsynthetic modification. Hollow MOP spheres bearing Fe3O4 yolks (Fe3O4@Void@MOP) were prepared by the synthesis of MOP on Fe3O4@SiO2 nanoparticles and by successive silica etching. In addition to the magneto-thermal function of Fe3O4 yolks, an aggregation-induced emission (AIE) feature was incorporated into the Fe3O4@Void@MOP through a homocoupling of tetra(4-ethynylphenyl)ethylene to form Fe3O4@Void@MOP-TE. Folate groups were further introduced into Fe3O4@Void@MOP-TE through the postsynthetic modification based on the thiol-yne click reaction. The resultant Fe3O4@Void@MOP-TE-FA showed multifunctionality in antitumoral therapy via folate receptor targeting, doxorubicin delivery, AIE-based imaging, and the magneto-thermal feature.

A Tellurium-Based Small Immunomodulatory Molecule Ameliorates Depression-Like Behavior in Two Distinct Rat Models.

Major depressive disorder (MDD) is a leading cause of morbidity, and the fourth leading cause of disease burden worldwide. While MDD is a treatable condition for many individuals, others suffer from treatment-resistant depression (TRD). Here, we suggest the immunomodulatory compound AS101 as novel therapeutic alternative. We previously showed in animal models that AS101 reduces anxiety-like behavior and elevates levels of the brain-derived neurotrophic factor (BDNF), a protein that has a key role in the pathophysiology of depression. To explore the potential antidepressant properties of AS101, we used the extensively characterized chronic mild stress (CMS) model, and the depressive rat line (DRL Finally, in Exp. 3 to attain insight into the mechanism we knocked down BDNF in the hippocampus, and demonstrated that the beneficial effect of AS101 was abrogated. Together with the previously established safety profile of AS101 in humans, these results may represent the first step towards the development of a novel treatment option for MDD and TRD.

Absorption of Ethylene on Membranes Containing Potassium Permanganate Loaded into Alumina-Nanoparticle-Incorporated Alumina/Carbon Nanofibers.

Ethylene is a natural aging hormone in plants, and controlling its concentration has long been a subject of research aimed at reducing wastage during packaging, transport, and storage. We report on packaging membranes, produced by electrospinning, that act as efficient carriers for potassium permanganate (PPM), a widely used ethylene oxidant. PPM salt loaded on membranes composed of alumina nanofibers incorporating alumina nanoparticles outperform other absorber systems and oxidize up to 73% of ethylene within 25 min. Membrane absorption of ethylene generated by avocados was totally quenched in 21 h, and a nearly zero ethylene concentration was observed for more than 5 days. By comparison, the control experiments exhibited a concentration of 53% of the initial value after 21 h and 31% on day 5. A high surface area of the alumina nanofiber membranes provides high capacity for ethylene absorption over a long period of time. In combination with other properties, such as planar form, flexibility, ease of handling, and lightweight, these membranes are a highly desirable component of packaging materials engineered to enhance product lifetime.

The effect of ethylene absorbent treatment on the softening of blueberry fruit.

The potential of ethylene absorbent (EA) to delay softening of 'Lanfeng' blueberry (Vaccinium spp.) fruit in conjunction with cold storage was evaluated. The fruit quality was evaluated after 60 days of storage at 0 °C again kept at 20 °C, with or without EA. Changes in quality attributes and ethylene biosynthesis and fruit softening indicators were assessed. The results indicated that EA treatment inhibited fruit softening, reduced weight loss and decay, and prevented the loss of total phenolic content. It also decreased the fruit ethylene production by inhibiting 1-aminocyclopropane-1-carboxylic acid oxidase and 1-aminocyclopropane-1- carboxylic acid synthase activities, whilst maintaining firmness by hampering cell wall-degrading enzyme activities, especially after more than 30 days of cold storage. In conclusion, EA treatment can inhibit the softening of harvested blueberry fruit during storage at 0 °C and shelf life after cold storage. After being refrigerated for more than 30 days at 0 °C, the EA has a good effect on blueberries storage.

Ultrasound-assisted chemoenzymatic epoxidation of soybean oil by using lipase as biocatalyst.

The present work reports the use of ultrasonic irradiation for enhancing lipase catalyzed epoxidation of soybean oil. Higher degree of unsaturated fatty acids, present in the soybean oil was converted to epoxidized soybean oil by using an immobilized lipase, Candida antarctica (Novozym 435). The effects of various parameters on the relative percentage conversion of the double bond to oxirane oxygen were investigated and the optimum conditions were established. The parameters studied were temperature, hydrogen peroxide to ethylenic unsaturation mole ratio, stirring speed, solvent ratio, catalyst loading, ultrasound frequency, ultrasound input power and duty cycle. The main objective of this work was to intensify chemoenzymatic epoxidation of the soybean oil by using ultrasound, to reduce the time required for epoxidation. Epoxidation of the soybean oil was achieved under mild reaction conditions by indirect ultrasonic irradiations (using ultrasonic bath). The relative percentage conversion to oxirane oxygen of 91.22% was achieved within 5h. The lipase was remarkably stable under optimized reaction conditions, later was recovered and reused six times to produce epoxidized soybean oil (ESO).

New Generation Agent Defeat Weapons: Energetic N,N'-Ethylene-Bridged Polyiodoazoles.

Sodium salts of iodine-rich pyrazole and imidazole with 1-(2-bromoethyl)-5-aminotetrazole are useful precursors for energetic N,N'-ethylene-bridged polyiodoazoles. Compounds 1-3 were characterized with IR, and 1 H and 13 C NMR spectroscopy as well as elemental analyses. The molecular structures of 1 and 2 were confirmed by using single crystal X-ray diffraction. Heats of formation were calculated using Gaussian 03 and detonation properties and biocidal efficiency were calculated with CHEETAH 7. The decomposition products of 1-3 destroy microbes more effectively than some previously reported biocides since the thermal decomposition occurs at below 400 °C without addition of oxidizer or combustion adjuvant.

Anthocyanin concentration depends on the counterbalance between its synthesis and degradation in plum fruit at high temperature.

Anthocyanin synthesis and degradation processes were analyzed at transcript, enzyme, and metabolite levels to clarify the effects of high temperature on the concentration of anthocyanin in plum fruit (Prunus salicina Lindl.). The transcript levels of PsPAL, PsCHS, and PsDFR decreased while those of PsANS and PsUFGT were similar at 35 °C compared with 20 °C. The activities of the enzymes encoded by these genes were all increased in fruits at 35 °C. The concentrations of anthocyanins were higher at 35 °C on day 5 but then decreased to lower values on day 9 compared with that at 20 °C. Furthermore, high temperature (35 °C) increased the concentration of hydrogen peroxide and the activity of class III peroxidase in the fruit. The concentration of procatechuic acid, a product of the reaction between anthocyanin and hydrogen peroxide, hardly changed at 20 °C but was significantly increased at 35 °C on day 9, indicating that anthocyanin was degraded by hydrogen peroxide, which was catalyzed by class III peroxidase. Based on mathematical modeling, it was estimated that more than 60-70% was enzymatically degraded on day 9 when the temperature increased from 20 °C to 35 °C. We conclude that at the high temperature, the anthocyanin content in plum fruit depend on the counterbalance between its synthesis and degradation.

Encapsulation of Ethylene Gas into Granular Cold-Water-Soluble Starch: Structure and Release Kinetics.

Ethylene gas was introduced into granular cold-water-soluble (GCWS) starches using a solid encapsulation method. The morphological and structural properties of the novel inclusion complexes (ICs) were characterized using scanning electron microscopy, X-ray diffractometry, and Raman spectroscopy. The V-type single helix of GCWS starches was formed through controlled gelatinization and ethanol precipitation and was approved to host ethylene gas. The controlled release characteristics of ICs were also investigated at various temperature and relative humidity conditions. Avrami's equation was fitted to understand the release kinetics and showed that the release of ethylene from the ICs was accelerated by increasing temperature or RH and was decelerated by increased degree of amylose polymerization. The IC of Hylon-7 had the highest ethylene concentration (31.8%, w/w) among the five starches, and the IC of normal potato starch showed the best controlled release characteristics. As a renewable and inexpensive material, GCWS starch is a desirable solid encapsulation matrix with potential in agricultural and food applications.

Postharvest Application of Oligochitosan and Chitosan Reduces Calyx Alterations of Citrus Fruit Induced by Ethephon Degreening Treatment.

In the present study, we investigated whether the postharvest application of oligochitosan and chitosan could be used as potential alternatives to 2,4-dichlorophenoxyacetic acid (2,4-D) treatment to prevent calyx senescence of mandarin fruits induced by degreening treatment. The results of scanning electron microscopy indicated that the ethephon degreening treatment could accelerate the formation of pedicel abscission layers. Treatments with 15 g kg-1 oligochitosan, 5 g kg-1 chitosan, and 50 mg kg-1 2,4-D significantly suppressed the formation of pedicel abscission layers of ethephon degreening fruit and inhibited the browning of the calyx. These two treatments delayed the degradation of protopectin, cellulose, and lignin. Inhibition of the increase in the abscisic acid (ABA) content was also observed in these two treatments. In conclusion, these two treatments, particularly 15 g kg-1 oligochitosan, could be potentially used as alternatives to 2,4-D to improve calyx alterations induced by the ethephon degreening treatment in mandarin fruits.

Impact of Cultivation Conditions, Ethylene Treatment, and Postharvest Storage on Selected Quality and Bioactivity Parameters of Kiwifruit "Hayward" Evaluated by Analytical and Chemometric Methods.

Organic, semiorganic, and conventional "Hayward" kiwifruits, treated with ethylene for 24 h and stored during 10 days, were assessed by UV spectrometry, fluorometry, and chemometrical analysis for changes in selected characteristics of quality (firmness, dry matter and soluble solid contents, pH, and acidity) and bioactivity (concentration of polyphenols via Folin-Ciocalteu and p-hydroxybenzoic acid assays). All of the monitored qualitative parameters and characteristics related to bioactivity were affected either by cultivation practices or by ethylene treatment and storage. Results obtained, supported by statistical evaluation (Friedman two-way ANOVA) and chemometric analysis, clearly proved that the most significant impact on the majority of the evaluated parameters of quality and bioactivity of "Hayward" kiwifruit had the ethylene treatment followed by the cultivation practices and the postharvest storage. Total concentration of polyphenols expressed via p-hydroxybenzoic acid assay exhibited the most significant sensitivity to all three evaluated parameters, reaching a 16.5% increase for fresh organic compared to a conventional control sample. As a result of postharvest storage coupled with ethylene treatment, the difference increased to 26.3%. Three-dimensional fluorescence showed differences in the position of the main peaks and their fluorescence intensity for conventional, semiorganic, and organic kiwifruits in comparison with ethylene nontreated samples.

Slow softening of Kanzi apples (Malus×domestica L.) is associated with preservation of pectin integrity in middle lamella.

Kanzi is a recently developed apple cultivar that has an extremely low ethylene production, and maintains its crispiness during ripening. To identify key determinants of the slow softening behaviour of Kanzi apples, a comparative analysis of pectin biochemistry and tissue fracture pattern during different ripening stages of Kanzi apples was performed against Golden Delicious, a rapid softening cultivar. While substantial pectin depolymerisation and solubilisation was observed during softening in Golden Delicious apples, no depolymerisation or increased solubilisation was observed in Kanzi apples. Moreover, tissue failure during ripening was mainly by cell breakage in Kanzi apples and, in contrast, by cell separation in Golden Delicious apples. Kanzi apples had lower activity of beta-galactosidase, with no decline in the extent of branching of the pectin chain. A sudden decrease in firmness observed during senescence in Kanzi apples was not due to middle lamella dissolution, as tissue failure still occurred by cell breakage.

The zinc spark is an inorganic signature of human egg activation.

Egg activation refers to events required for transition of a gamete into an embryo, including establishment of the polyspermy block, completion of meiosis, entry into mitosis, selective recruitment and degradation of maternal mRNA, and pronuclear development. Here we show that zinc fluxes accompany human egg activation. We monitored calcium and zinc dynamics in individual human eggs using selective fluorophores following activation with calcium-ionomycin, ionomycin, or hPLCζ cRNA microinjection. These egg activation methods, as expected, induced rises in intracellular calcium levels and also triggered the coordinated release of zinc into the extracellular space in a prominent "zinc spark." The ability of the gamete to mount a zinc spark response was meiotic-stage dependent. Moreover, chelation of intracellular zinc alone was sufficient to induce cell cycle resumption and transition of a meiotic cell into a mitotic one. Together, these results demonstrate critical functions for zinc dynamics and establish the zinc spark as an extracellular marker of early human development.

A density functional theory study of ethylene hydrogenation on MgO- and γ-Al2O3-supported carbon-containing Ir4 clusters.

Density functional theory was used to investigate the reaction mechanisms of ethylene hydrogenation on MgO(100)- and γ-Al2O3(110)-supported carbon-containing Ir4 clusters. The cluster supported on γ-Al2O3(110) is more active than that on MgO(100), which is consistent with experimental observations. The present calculations show that the binding energies of reactants on the carbon-containing Ir4 cluster are weaker on the γ-Al2O3 supported catalysts compared to the MgO supported Ir cluster. This relatively weak adsorption energy of ethylene on the γ-Al2O3 surface means that ethylene desorption is easier, hence a higher catalytic activity is achieved. To gain further understanding, the energy decomposition method and micro-kinetic analysis are also introduced.

Nitroxide-mediated radical ring-opening copolymerization: chain-end investigation and block copolymer synthesis.

Well-defined, degradable copolymers are successfully prepared by nitroxide-mediated radical ring opening polymerization (NMrROP) of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) or methyl methacrylate (MMA), a small amount of acrylonitrile (AN) and cyclic ketene acetals (CKAs) of different structures. Phosphorous nuclear magnetic resonance allows in-depth chain-end characterization and gives crucial insights into the nature of the copoly-mer terminal sequences and the living chain fractions. By using a small library of P(OEGMA-co-AN-co-CKA) and P(MMA-co-AN-co-CKA) as macroinitiators, chain extensions with styrene are performed to furnish (amphiphilic) block copolymers comprising a degradable segment.

Economic feasibility of the sugar beet-to-ethylene value chain.

As part of a long-term strategy toward renewable feedstock, a feasibility study into options for the production of bioethylene by integrating the sugar beet-to-ethanol-to-ethylene value chain. Seven business cases were studied and tested for actual economic feasibility of alternative sugar-to-ethanol-to-ethylene routes in comparison to fossil-fuel alternatives. An elaborate model was developed to assess the relevant operational and financial aspects of each business case. The calculations indicate that bioethylene from sugar beet is not commercially viable under current market conditions. In light of expected global energy and feedstock prices it is also reasonable to expect that this will not change in the near future. To consider biorenewable sources as starting material, they need to be low in cost (compared to sugar beets) and also require less capital and energy-intensive methods for the conversion to chemicals. In general, European sugar prices will be too high for many chemical applications. Future efforts for in sugar-to-chemicals routes should, therefore, focus on integrated process routes and process intensification and/or on products that contain a significant part of the original carbohydrate backbone.

Reversible photo-controllable gels based on bisthienylethene-doped lecithin micelles.

An aza-15-crown-5-ether functionalized bisthienylethene (BTE-15C5) was synthesized, which can reversibly capture and release calcium ions by UV/Vis irradiation. After doping this photochromic bisthienylethene with a two-component lecithin-Ca(2+) organogel, the original deep-blue gel changed to light-blue fluid due to the cooperative binding with Ca(2+) by the open-form bisthienylethene dopant. Upon UV irradiation, the closed isomer was formed which released the Ca(2+) and the organogel was retrieved. Hence, a novel organic simple doped-type three-component photo-induced gel-to-sol transition system was constructed.

Clinically relevant fracture testing of all-ceramic crowns.

OBJECTIVES: Fracture strength measured in vitro indicates that most all-ceramic crowns should be able to withstand mastication forces. Nevertheless, fractures are one of the major clinical problems with all-ceramic restorations. Furthermore, the fracture mode of all-ceramic crowns observed in clinical use differs from that found in conventional fracture strength tests. The aim of the present study was to develop and investigate a method that simulates clinical fracture behavior in vitro. METHODS: 30 crowns with alumina cores were made to fit a cylindrical model with a molar-like preparation design. These crowns were randomly allocated to 3 tests groups (n=10). The crowns in group 1 were cemented to abutment models of epoxy and subsequently fractured by occlusal loading without contact damage. The crowns in group 2 were fractured by cementation with expanding cement. The crowns in group 3 were cemented on an abutment model of epoxy split almost in two and fractured by increasing the diameter of the model in the bucco-lingual direction. The fractured crowns were analyzed by fractographic methods and compared to a reference group of 10 crowns fractured in clinical use. RESULTS: The fracture modes of all the in vitro crowns were similar to clinical fracture modes. The fracture modes in group 1 were most closely matched to the clinical fractures. These crowns also fractured at clinically relevant loads. CONCLUSION: Laboratory tests that induce a distortion of the abutment model during occlusal loading without occlusal contact damage can simulate clinical fractures of all-ceramic crowns.

Health-promoting effects of ethylene-treated kiwifruit 'Hayward' from conventional and organic crops in rats fed an atherogenic diet.

Kiwifruit is a subtropical fruit that is very popular among consumers. Kiwifruit 'Hayward' ( Actinidia deliciosa C.F. Liang et A.R. Ferguson) is an important source of bioactive compounds and possesses high antioxidant capacity, but its value can be changed during ripening. The aim of this study was to compare the levels of total polyphenols (TP), ascorbic acid (AA), and total antioxidant capacities (TACs) of ethylene-treated and nontreated kiwifruits 'Hayward' from conventional and organic farming. The influence of these fruits on lipid profile, TAC, and liver enzymes in plasma of rats fed diets with cholesterol was studied. Ethylene treatment shortened the ripening of kiwifruits. Ethylene-treated kiwifruits from organic farming (OHE) have the highest contents of TP and TAC. The experiment in vivo was performed during 33 days on male Wistar rats (111 ± 5 g), divided into six groups: one without cholesterol, control (C), and five groups with 1% of cholesterol (Chol). Four groups with cholesterol were supplemented with 5% of lyophilized kiwifruits: ethylene treated, organic (Chol/OHE) or conventional (Chol/CHE); and untreated, organic (Chol/OHC) or conventional (Chol/CHC). Cholesterol diets supplemented with kiwifruit influenced the palatability and feed intake, body gain, and FER. Diets containing kiwifruits significantly influenced the decrease of TG (61%), TC (29%), LDL-C (38%), atherogenic index TC/HDL-C (25%), and atherogenic index (AI, 32%), without differences between treatments. A significant increase of TAC in plasma of rats fed kiwifruit was obtained by DPPH (18%), FRAP (55%), and ABTS (55%). Aspartate aminotransferase (AST) activity in serum was significantly lower for all groups with kiwifruit supplementation. Alanine aminotransferase (ALT) was lower only in diet groups supplemented with conventional fruits in comparison with the cholesterol group. Glucose levels were higher in groups with kiwifruit supplementation than in C and Chol groups. Supplementation of Chol groups with organic kiwifruits influenced the prothrombin index and significantly decreased the amount of platelets (PLT) in blood. In conclusion, studied kiwifruit 'Hayward' can be a very good ingredient of the diet, especially for patients suffering from hypercholesterolemia and with other cardiovascular diseases, but not for diabetic patients.

Organoactinides in the polymerization of ethylene: is TIBA a better cocatalyst than MAO?

The synthesis of two pyridylamidinate bis(N,N'-bis(trimethylsilyl)-2-pyridylamidinate)An(µ-Cl)2Li(TMEDA) (An = U (1), Th (2)) complexes is presented. For complex 1 the solid state X-ray structures were studied and compared to that of complex 2. The organoactinide complexes were studied as pre-catalysts in the polymerization of ethylene when activated by methylalumoxane (MAO). The catalytic activity was improved using a mixture of trityl tetrakispentafluorophenylborate (TTPB) and a small amount of methylalumoxane (MAO) as cocatalysts, and was amazingly improved, providing the greatest activity, using only triisobutyl aluminum (TIBA). We present a combination of ESR, C60 radical trapping, and MALDI-TOF studies describing the formation of the single-site active species, capturing some unique features of the complexes and shedding light on the polymerization mechanism.