Effect of long-chain branching molar fraction on scratch behavior of polypropylene

Polymers containing a certain amount of long-chain-branching (LCB) structure are expected to possess improved mechanical properties over those of the linear structure counterpart. However, fundamental knowledge on the structure–property relationship in LCB containing polypropylene (PP) is still illusive. In the present study, a set of model PP systems containing an increasing molar fraction of LCB (5–19 mol%) were prepared by reactive extrusion to determine how LCB content may influence the scratch behavior of PP. It is shown that with only 5 mol% of LCB content in PP can improve resistance against scratch-induced fish-scale formation by over 25%. The improvement of scratch resistance is attributed to the increases in entanglement density in LCB-containing PPs, which is evidenced by their creep-recovery behavior. The present study demonstrates that the incorporation of LCB in PP leads to higher viscoelastic recovery and increased tensile strength, which account for the observed improvement in scratch performance. The usefulness of LCB in polymers for improving scratch performance is discussed.     

Subcellular Localization of Acyl-CoA: Lysophosphatidylethanolamine Acyltransferases (LPEATs) and the Effects of Knocking-Out and Overexpression of Their Genes on Autophagy Markers Level and Life Span of A. thaliana

Arabidopsis thaliana possesses two acyl-CoA:lysophosphatidylethanolamine acyltransferases, LPEAT1 and LPEAT2, which are encoded by At1g80950 and At2g45670 genes, respectively. Both single lpeat2 mutant and double lpeat1 lpeat2 mutant plants exhibit a variety of conspicuous phenotypes, including dwarfed growth. Confocal microscopic analysis of tobacco suspension-cultured cells transiently transformed with green fluorescent protein-tagged versions of LPEAT1 or LPEAT2 revealed that LPEAT1 is localized to the endoplasmic reticulum (ER), whereas LPEAT2 is localized to both Golgi and late endosomes. Considering that the primary product of the reaction catalyzed by LPEATs is phosphatidylethanolamine, which is known to be covalently conjugated with autophagy-related protein ATG8 during a key step of the formation of autophagosomes, we investigated the requirements for LPEATs to engage in autophagic activity in Arabidopsis. Knocking out of either or both LPEAT genes led to enhanced accumulation of the autophagic adaptor protein NBR1 and decreased levels of both ATG8a mRNA and total ATG8 protein. Moreover, we detected significantly fewer membrane objects in the vacuoles of lpeat1 lpeat2 double mutant mesophyll cells than in vacuoles of control plants. However, contrary to what has been reported on autophagy deficient plants, the lpeat mutants displayed a prolonged life span compared to wild type, including delayed senescence.     

DNA Methylation Signatures of Bone Metabolism in Osteoporosis and Osteoarthritis Aging-Related Diseases: An Updated Review

DNA methylation is one of the most studied epigenetic mechanisms that play a pivotal role in regulating gene expression. The epigenetic component is strongly involved in aging-bone diseases, such as osteoporosis and osteoarthritis. Both are complex multi-factorial late-onset disorders that represent a globally widespread health problem, highlighting a crucial point of investigations in many scientific studies. In recent years, new findings on the role of DNA methylation in the pathogenesis of aging-bone diseases have emerged. The aim of this systematic review is to update knowledge in the field of DNA methylation associated with osteoporosis and osteoarthritis, focusing on the specific tissues involved in both pathological conditions.     

Fire safe,sustainable loose furnishing

The aim of this exploratory study has been to investigate the fire properties and environmental aspects of different upholstery material combinations, mainly for domestic applications. An analysis of the sustainability and circularity of selected textiles, along with lifecycle assessment, is used to qualitatively evaluate materials from an environmental perspective. The cone calorimeter was the primary tool used to screen 20 different material combinations from a fire performance perspective. It was found that textile covers of conventional fibres such as wool, cotton and polyester, can be improved by blending them with fire resistant speciality fibres. A new three‐dimensional web structure has been examined as an alternative padding material, showing preliminary promising fire properties with regard to ignition time, heat release rates and smoke production.     

Use of durum residue flour,a lower value product of durum milling,by incorporation into wheat flour dough without deterioration in baking quality

BACKGROUND: During the milling of durum wheat to semolina, about 10–15% of total products produced is residue flour, a lower value product than the semolina. This study investigated the potential for using the durum residue flour as an additive in bread‐making to improve its potential commercial value. RESULTS: Incorporation of residue durum flour from 102 breeding lines into a low protein flour and standard bakers' flour at 20% incorporation improved the bake loaf volume with minimal change in Mixograph dough mixing time and peak resistance in many of the lines tested. Loaf yellow b was always increased even with only a 10% incorporation. Baking flours can tolerate 20% incorporation with no deleterious affects on loaf volume and bake score. CONCLUSION: The results show a potential for using the lower value durum residue flour for baking bread of acceptable quality with a slightly higher yellow colour. This would improve the profitability for the miller and provide alternative ingredients to the baker for preparing specialty breads. Copyright © 2008 Crown in the Right of the State of New South Wales and Society of Chemical Industry     

Book reviews

BT Environment City Bulletin: The Big Picture - all eight topics under one roof Edited by C. Wood, 1994, Lincoln, The Wildlife Trusts, 110pp., £19.00 for local authorities, £14.00 for local businesses, £9.00 for voluntary groups.

Theme Parks, Leisure Centres, Zoos and Aquaria Anthony and Patricia Wylson, 1994, Harlow, Longman, 183pp. ISBN 0 582 09928 5, hb £60.00

The Picturesque Landscape: Visions of Georgian Herefordshire Edited by Stephen Daniels and Charles Watkins, 1994, Department of Geography, University of Nottingham, 100pp. ISBN 0 85358 033 2, £7.50

The Countryside Ideal: Anglo-American Images of Landscape Michael Bunce, 1994, London, Routledge, 232pp. ISBN 0 415 10435 1

Ordering Space: Types in Architecture and Design Karen A Frank and Lynda H Schneekloth (eds.), 1994, New York, Van Norstrand Reinhold, 383pp ISBN 0 442 01233 0, pb £34.50     

Assessing terrestrial wildlife populations in the Toronto and Region Area of Concern

Beneficial use impairments (BUIs) under the Great Lakes Water Quality Agreement identify environmental issues requiring remedial action within the Great Lakes Areas of Concern (AOCs). We conducted this study to support the assessment of the wildlife component of BUI 3: degradation of fish and wildlife populations. We compared bird and amphibian (frogs and toads) data from the Toronto and Region Conservation Authority’s Terrestrial Long-term Monitoring Program in the Toronto and Region AOC to an adjacent, but otherwise similar, reference watershed, Duffins Creek. Twelve of 13 targets were met within the AOC for forest bird, wetland bird, meadow bird and amphibian populations based on averages of mean annual values at sites within the AOC that were within two standard deviations of averages at sites in the Duffins Creek reference watershed between 2008 and 2017. Even though wildlife populations within the AOC were within the normal range of variability expected from a reference watershed, they were often at lower levels than within the Duffins Creek reference watershed. In addition, forest bird and amphibian populations were negatively affected by urbanization within the AOC and meadow bird indices declined. We conclude that while wildlife populations within the AOC currently meet targets for BUI 3, they continue to be negatively impacted by numerous stressors that are primarily related to past and ongoing urbanization. Thus, continued restoration of wildlife habitat and protection of existing habitat within the AOC is highly recommended.     

Low bandgap carbazole copolymers containing an electron-withdrawing side chain for solar cell applications

A new series of low bandgap carbazole copolymers containing an electron-withdrawing moiety as a side chain, via Suzuki, Yamamoto, and Stille polymerization reactions has been synthesized. Their bandgaps and molecular energy levels can be tuned by copolymerizing with different conjugated electron-donating units. The resulting copolymers have low optical and electrochemical bandgaps. The optical bandgaps of the copolymers range from 1.79 to 1.24 eV. In order to investigate their photovoltaic properties, polymer solar cell devices based on low bandgap copolymers were fabricated with a structure of ITO/PEDOT:PSS/copolymers:PCBM/Al, under the illumination of AM 1.5 G, 100 mW/cm². The power conversion efficiencies (PCE) of the polymer solar cells based on these low bandgap copolymers were measured. The best performance was obtained by using PC-CARB as the electron donor and 6,6-phenyl C₇₁-butyric acid methyl ester (PC₇₁BM) as the electron acceptor. The PCE of the solar cell based on PC-CARB/P₇₁CBM (1:4) was 1.27% with an open-circuit voltage (V_oc) of 0.65 V, and a short-circuit current (J_sc) of 6.69 mA/cm².     

Molecular inflammation hypothesis of aging based on the anti-aging mechanism of calorie restriction

Accumulating evidence strongly suggests that oxidative stress underlies aging processes. Research provides consistent evidence that calorie restriction (CR) reduces age-related oxidative stress and has anti-inflammatory properties. However, information is lacking on the molecular mechanism that would better define the interrelation of reactive oxygen species and nitrogen species and the pro-inflammatory states of the aging process. In this review, the biochemical and molecular bases of the inflammatory process in the aging process are analyzed to delineate the molecular inflammation hypothesis of aging. The key players involved in the proposed hypothesis are the age-related upregulation of NF-kappa B, IL-1 beta, IL-6, TNFalpha, cyclooxygenase-2, and inducible NO synthase, all of which are attenuated by CR. Furthermore, age-related NF kappa B activation is associated with phosphorylation by I kappa B kinase/NIK and MAPKs, while CR blocked these activation processes. The modulation of these factors provides molecular insights of the anti-inflammatory action of CR in relation to the aging process. Based on available finding and our recent supporting evidence, we prefer to use "molecular inflammation" to emphasize the importance of the molecular reaction mechanisms and their aberrance, predisposing to fully expressed chronic inflammatory phenomena. It was further proposed that CR's major force of the regulation of redox-sensitive inflammation may well be its life-prolonging action.