How to Combine Elasticity with Fire Protection?:Progress in Ceramifiable Composites Development

One of the most unique features of polymeric materials is their ability to undergo elastic, reversible deformation. A group of polymers exhibiting such properties owns even an exceptional name – elastomers. The relevance of elastic properties is undeniable in numerous industrial applications form high-performance tyres to seals, gaskets, hoses, cables, and plenty others functional materials manufacturing. However, the hydrocarbon or siloxane macromolecular structure providing elastomeric properties bears also some considerable drawbacks. High flammability is one of the most severe among them. Grand prevalence of polymer materials poses a serious fire threat in households, public, industrial and commercial buildings, as well as mass or private transport vehicles. In order to reduce the fire threat, different approaches with regard to material development and fire-safety are explored. Increase of fire resistance of polymer materials can be provided by chemical modification of the polymer macromolecules or incorporation of flame retardant additives. These additives can be divided according to the mechanism of their action into chemical (suppressing the radical mechanism of fire growth), physical (heat consumption or dissipation, enhancing the polymer/fire barrier interphase) or physicochemical flame retardants. Very often the physical-flame retardants are also called passive-flame retardants due to the fact that they do not generate any harmful products during the fire suppressing mechanism. This makes them more suitable for polymers devoted to applications in densely populated places. One of the most promising paths of increasing the fire resistance of polymers is the development of ceramifiable composites. These materials consist of a polymeric (most often elastomeric) continuous matrix and a properly designed mix of fillers triggering structural conversion under fire/elevated-temperature conditions from elastic composite to brittle ceramics [1]. The ceramic structure formed exhibits continuous morphology and high mechanical and thermal-barrier properties, improving not only fire resistance of the composite but also providing a significant fire/heat protection to the element coated by the composite. Therefore, the interest in these composites is growing considerably. Starting with their utilization as special, fire-resistant cable covers [2-4] and developing into coating for construction-steel elements [5] or anti-ablative materials [6]. The aim of this work is to review current trends in the ceramifiable composites development. Mechanisms of the ceramification phenomena will be presented and discussed, with an emphasis on the latest physical [7] and physicochemical [8] approaches. Tailoring of properties of the composites by functional additives [9, 10] and using new polymers as the composites matrices [11, 12] will also be reviewed. 1. L.G. Hanu, O.P. Simon, J. Mansouri, R.P. Burford and Y.B. Cheng, Journal of Materials Processing Technology 153-154, 401 (2004). 2. S. Hamdani, C. Longuet, J-M. Lopez-Cuesta and F. Ganachaud, Polymer Degradation and Stability 95, 1911 (2010) 3. S. Hamdani-Devarennes, A. Pommier, C. Longuet, J-M. Lopez-Cuesta and F. Ganachaud, Polymer Degradation and Stability 96, 1562 (2011) 4. S. Hamdani-Devarennes, C. Longuet, R. Sonnier, F. Ganachaud and J-M. Lopez-Cuesta, Polymer Degradation and Stability 98, 2021 (2013) 5. B. Gardelle, S. Duquesne, P. Vandereecken and S. Bourbigot, Journal of Fire Sciences 32, 374 (2014) 6. G. Zhang, F. Wang, Z. Huang, J. Dai and M Shi, Materials 9, 723 (2016) 7. X. Zhang, Y. Guan, Y. Xie and D. Qiu, RSC Advances 6, 7970 (2016) 8. S. Hu, F. Chen, J-G. Li, Q. Shen, Z-X Huang and L-M Zhang, Polymer Degradation and Stability 126, 196 (2016) 9. R. Anyszka, D.M. Bielinski, Z. Pedzich and M. Szumera, Journal of Thermal Analysis and Calorimetry 119, 111 (2015). 10. M. Imiela, R. Anyszka, D.M. Bielinski, Z. Pedzich, M. Zarzecka-Napierala and M. Szumera, Journal of Thermal Analysis and Calorimetry 124, 197 (2016). 11. R. Anyszka, D.M. Bielinski, Z. Pedzich, P. Rybinski, M. Imiela, M. Sicinski, M. Zarzecka-Napieraa, T. Gozdek and P. Rutkowski, Materials 9, 604 (2016). 12. H-W. Di, C. Deng, R-M. Li, L-P. Dong and Y-Z. Wang, RSC Advances 5, 51248 (2015

Mimicking the velcro system from the nature for an alternative rubber/silica coupling system

Beside carbon black, silica becomes the most important filler for high-performance rubber products. However, unlike carbon black its surface properties are not favorable for providing satisfactory rubber/filler interactions. A significant amount of silanol groups present on the silica surface results in a considerably polar character, whereas most of rubbers exhibit a non-polar or relatively low-polar character. Because of this, various approaches towards different surface treatments of silica were made. Currently, it is state of the art that thesilanization with sulfide-silanes or mercaptosilanes is applied to provide an improved rubber/filler couplingvia sulfur links during vulcanization of rubber. Such solution results in the formation of strong, covalent bonds between the silica surface and rubber macromolecules giving the required performance. However, the covalent, sulfur links are relatively stiff and once broken they are unable to reconnect. Moreover, this type of coupling provides only one type of rubber/filler connections via sulfur chains, therefore not leaving much space for tailoring and modifying the interactions. The aim of this research is to introduce an alternative type of rubber/silica coupling inspired by the velcro system existing in nature. The bio-mimicking mechanism bases on physical entanglements and steric hindrance between tangled rubber macromolecules – acting as molecular loops - and oligomer brushes grafted on the silica surface – acting as molecular hooks. This results in the formation of molecular hooks- and-loops, a rubber/silica interphasefastener.The oligomer brushes were synthesized using a monohydroxy telechelic butadiene oligomercontaining ca. 65 % of monomeric units in vinyl configuration as a backbone, which wasconnected to the silica surface via an isocyanate silane. Afterwards, various thiols were attached to this oligomeric backbone by radical reaction with the vinyl groups of the oligomer. Depending on the chemical structure of the used thiols, these synthesized brushes interact differently with the rubber matrix influencing macroscopic properties of the rubber compound. This approach allows tailoring of rubber/filler interactions by using thiols of various chemical structures as side groups of an oligomer backbone. A major advantage of this coupling system is the possibility to reconnect the rubber/filler physical joints after their detachment. The present work is the first step towards the implementation of a velcro-likefastener as analternative coupling method between rubber and silica

Perubahan Struktural Dalam Pembangunan Perkotaan

Pertumbuhan daerah kota di negra berkembang menunjukan gejala yang tidak di harapkan.untuk mengantisipasi kondisi keterbelakangan ini, daerah perkotaan haurus di dorong secara kuat untuk meningkatkan permintaan terhadap barang dan pelayanan untuk seluruh kepentingan nasional. permasalahan kota yang telah di hadapi bukan hanya persoalan keruangan dan Perubahan struktur ekonomi saja, tapi juga pembentukan implikasi sosial dan lingkungan. hal ini dapat di lihat di Bogota dengan pola dualisme sistem sosialnya, adanya pemisahan ruang antara masyarakat kaya di daerah utara dan masyarakat miskin di daerah selatan dan barat. Fenomena serupa juga di temukan di Indonesia. Jakarta yang berkembang secara cepat dengan dukungan sektor manufaktur dan keuanga, mencapai kondisi ekonomi dan pendapatan yang baik. Bagaimanapun, di Balik kondisi tersebut, ditemukan biaya yang tak terhindarkan secara nyata, yang umum muncul berupa penurunan kualitas lingkungan. Beberapa kebijaksanaan direkomendasikan adalah: (1) Meningkatkan produktivitas ekonomi wilayah kota yang terintegrasi ke dalam pembangunan regional dan pedesaan, (2) Meningkatkan produktivitas kelompok miskin perkotaan melalui perbaikan infrastruktur sosial dan perluasan kesempatan kerja, (3) Menghindari Perusakan lingkungan serta konsekwensi lainnya di sekitar wilayah masyarakat miskin, dan (4) Membangun persepsi yang seimbang terhadap pembangunan kota dan permasalahan-permasalahan yang berkaitan dengannya: pemerintah, sektor swasta, dan masyarakat

TCF7L2 single nucleotide polymorphisms, cardiovascular disease and all-cause mortality: the Atherosclerosis Risk in Communities (ARIC) study

We hypothesize that transcription factor 7-like 2 (TCF7L2) single nucleotide polymorphisms (SNPs) are associated with cardiovascular disease (CVD) and that the associations differ in diabetic and non-diabetic participants

Association of sICAM-1 and MCP-1 with coronary artery calcification in families enriched for coronary heart disease or hypertension: the NHLBI Family Heart Study

<p>Abstract</p> <p>Background</p> <p>Data accumulated from mouse studies and in vitro studies of human arteries support the notion that soluble intercellular adhesion molecule-1 (sICAM-1) and monocyte chemoattractant protein-1 (MCP-1) play important roles in the inflammation process involved in atherosclerosis. However, at the population level, the utility of sICAM-1 and MCP-1 as biomarkers for subclinical atherosclerosis is less clear. In the follow-up exam of the NHLBI Family Heart Study, we evaluated whether plasma levels of sICAM-1 and MCP-1 were associated with coronary artery calcification (CAC), a measure of the burden of coronary atherosclerosis.</p> <p>Methods</p> <p>CAC was measured using the Agatston score with multidetector computed tomography. Information on CAC and MCP-1 was obtained in 2246 whites and 470 African Americans (mean age 55 years) without a history of coronary heart disease (CHD). Information on sICAM-1 was obtained for white participants only.</p> <p>Results</p> <p>In whites, after adjustment for age and gender, the odds ratios (ORs) of CAC (CAC > 0) associated with the second, third, fourth, and fifth quintiles of sICAM-1 compared to the first quintile were 1.22 (95% confidence interval [CI]: 0.91–1.63), 1.15 (0.84–1.58), 1.49 (1.09–2.05), and 1.72 (1.26–2.36) (p = 0.0005 for trend test), respectively. The corresponding ORs for the second to fifth quintiles of MCP-1 were 1.26 (0.92–1.73), 0.99 (0.73–1.34), 1.42 (1.03–1.96), and 2.00 (1.43–2.79) (p < 0.0001 for trend test), respectively. In multivariable analysis that additionally adjusted for other CHD risk factors, the association of CAC with sICAM-1 and MCP-1 was attenuated and no longer statistically significant. In African Americans, the age and gender-adjusted ORs of CAC associated with the second and third tertiles of MCP-1 compared to the first tertile were 1.16 (0.64–2.08) and 1.25 (0.70–2.23) (p = 0.44 for trend test), respectively. This result did not change materially after additional adjustment for other CHD risk factors. Test of race interaction showed that the magnitude of association between MCP-1 and CAC did not differ significantly between African Americans and whites. Similar results were obtained when CAC ≥ 10 was analyzed as an outcome for both MCP-1 and sICAM-1.</p> <p>Conclusion</p> <p>This study suggests that sICAM-1 and MCP-1 are biomarkers of coronary atherosclerotic burden and their association with CAC was mainly driven by established CHD risk factors.</p

TBC1D3, a Hominoid-Specific Gene, Delays IRS-1 Degradation and Promotes Insulin Signaling by Modulating p70 S6 Kinase Activity

Insulin/IGF-1 signaling plays a pivotal role in the regulation of cellular homeostasis through its control of glucose metabolism as well as due to its effects on cell proliferation. Aberrant regulation of insulin signaling has been repeatedly implicated in uncontrolled cell growth and malignant transformations. TBC1D3 is a hominoid specific gene previously identified as an oncogene in breast and prostate cancers. Our efforts to identify the molecular mechanisms of TBC1D3-induced oncogenesis revealed the role of TBC1D3 in insulin/IGF-1 signaling pathway. We document here that TBC1D3 intensifies insulin/IGF-1-induced signal transduction through intricate, yet elegant fine-tuning of signaling mechanisms. We show that TBC1D3 expression substantially delayed ubiquitination and degradation of insulin receptor substrate-1 (IRS-1). This effect is achieved through suppression of serine phosphorylation at S636/639, S307 and S312 of IRS-1, which are key phosphorylation sites required for IRS-1 degradation. Furthermore, we report that the effect of TBC1D3 on IRS-1:S636/639 phosphorylation is mediated through TBC1D3-induced activation of protein phosphatase 2A (PP2A), followed by suppression of T389 phosphorylation on p70 S6 kinase (S6K). TBC1D3 specifically interacts with PP2A regulatory subunit B56γ, indicating that TBC1D3 and PP2A B56γ operate jointly to promote S6K:T389 dephosphorylation. These findings suggest that TBC1D3 plays an unanticipated and potentially unique role in the fine-tuning of insulin/IGF-1 signaling, while providing novel insights into the regulation of tumorigenesis by a hominoid-specific protein

Essential Roles of the Tap42-Regulated Protein Phosphatase 2A (PP2A) Family in Wing Imaginal Disc Development of Drosophila melanogaster

Protein ser/thr phosphatase 2A family members (PP2A, PP4, and PP6) are implicated in the control of numerous biological processes, but our understanding of the in vivo function and regulation of these enzymes is limited. In this study, we investigated the role of Tap42, a common regulatory subunit for all three PP2A family members, in the development of Drosophila melanogaster wing imaginal discs. RNAi-mediated silencing of Tap42 using the binary Gal4/UAS system and two disc drivers, pnr- and ap-Gal4, not only decreased survival rates but also hampered the development of wing discs, resulting in a remarkable thorax cleft and defective wings in adults. Silencing of Tap42 also altered multiple signaling pathways (HH, JNK and DPP) and triggered apoptosis in wing imaginal discs. The Tap42RNAi-induced defects were the direct result of loss of regulation of Drosophila PP2A family members (MTS, PP4, and PPV), as enforced expression of wild type Tap42, but not a phosphatase binding defective Tap42 mutant, rescued fly survivorship and defects. The experimental platform described herein identifies crucial roles for Tap42•phosphatase complexes in governing imaginal disc and fly development

QTLs of factors of the metabolic syndrome and echocardiographic phenotypes: the hypertension genetic epidemiology network study

<p>Abstract</p> <p>Background</p> <p>In a previous study of the Hypertension Genetic Epidemiology Network (HyperGEN) we have shown that metabolic syndrome (MetS) risk factors were moderately and significantly associated with echocardiographic (ECHO) left ventricular (LV) phenotypes.</p> <p>Methods</p> <p>The study included 1,393 African Americans and 1,133 whites, stratified by type 2 diabetes mellitus (DM) status. Heritabilities of seven factor scores based on the analysis of 15 traits were sufficiently high to pursue QTL discovery in this follow-up study.</p> <p>Results</p> <p>Three of the QTLs discovered relate to combined MetS-ECHO factors of "blood pressure (BP)-LV wall thickness" on chromosome 3 at 225 cM with a 2.8 LOD score, on chromosome 20 at 2.1 cM with a 2.6 LOD score; and for "LV wall thickness" factor on chromosome 16 at 113.5 with a 2.6 LOD score in whites. The remaining QTLs include one for a "body mass index-insulin (BMI-INS)" factor with a LOD score of 3.9 on chromosome 2 located at 64.8 cM; one for the same factor on chromosome 12 at 91.4 cM with a 3.3 LOD score; one for a "BP" factor on chromosome 19 located at 67.8 cM with a 3.0 LOD score. A suggestive linkage was also found for "Lipids-INS" with a 2.7 LOD score located on chromosome 11 at 113.1 cM in African Americans. Of the above QTLs, the one on chromosome 12 for "BMI-INS" is replicated in both ethnicities, (with highest LOD scores in African Americans). In addition, the QTL for "LV wall thickness" on chromosome 16q24.2-q24.3 reached its local maximum LOD score at marker D16S402, which is positioned within the 5th intron of the <it>cadherin 13 </it>gene, implicated in heart and vascular remodeling.</p> <p>Conclusion</p> <p>Our previous study and this follow-up suggest gene loci for some crucial MetS and cardiac geometry risk factors that contribute to the risk of developing heart disease.</p

Genome-Wide Association Analysis of Soluble ICAM-1 Concentration Reveals Novel Associations at the NFKBIK, PNPLA3, RELA, and SH2B3 Loci

Soluble ICAM-1 (sICAM-1) is an endothelium-derived inflammatory marker that has been associated with diverse conditions such as myocardial infarction, diabetes, stroke, and malaria. Despite evidence for a heritable component to sICAM-1 levels, few genetic loci have been identified so far. To comprehensively address this issue, we performed a genome-wide association analysis of sICAM-1 concentration in 22,435 apparently healthy women from the Women's Genome Health Study. While our results confirm the previously reported associations at the ABO and ICAM1 loci, four novel associations were identified in the vicinity of NFKBIK (rs3136642, P = 5.4×10−9), PNPLA3 (rs738409, P = 5.8×10−9), RELA (rs1049728, P = 2.7×10−16), and SH2B3 (rs3184504, P = 2.9×10−17). Two loci, NFKBIB and RELA, are involved in NFKB signaling pathway; PNPLA3 is known for its association with fatty liver disease; and SH3B2 has been associated with a multitude of traits and disease including myocardial infarction. These associations provide insights into the genetic regulation of sICAM-1 levels and implicate these loci in the regulation of endothelial function