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More or less universally, bis(3-triethoxysilyl propyl) tetrasulfide (TESPT) has been used as a coupling agent during dispersion of silica filler in a virgin nonpolar rubber compound. It is for the first time that TESPT has been used as a devulcanizing agent and as-grown devulcanized rubber facilitates the silica dispersion in nonpolar rubber compound without any coupling agent. Dual functionalities of TESPT have been modeled and validated in this work. Various factors like the role of sol-gel content, inherent viscosity of sol rubber, crosslink density, and degree of devulcanization were investigated as a function of devulcanization time and amount of TESPT to optimize devulcanization time and TESPT amount. To study the silica reinforcement, revulcanization of devulcanized SBR was carried out with silica filler and the curing characteristics of the material were evaluated. From the mechanical properties and thermogravimetry analysis the optimum time for devulcanization is determined. Further, scanning electron microscopy (SEM) studies were undertaken to check the coherency and homogeneity of the material., INTRODUCTION Generally, the demand of styrene butadiene rubber (SBR) in tyre industries increases manifold primarily for less C[O.sub.2] emission since SBR offers low rolling resistance and hence accounts for low [...]

Identification of a new G-quadruplex ligand having anti-telomerase activity would be a promising strategy for cancer therapy. The screened compound from ZINC database using docking studies was experimentally verified for its binding with three different telomeric G-quadruplex DNA sequences and anti-telomerase activity in A549 cells. Identified compound is an intrinsic fluorescent molecule, permeable to live cells and has a higher affinity to 22AG out of three different telomeric G-quadruplex DNA. It showed cytotoxicity and a significant reduction of telomerase activity in human A549 cells at a very low dose. So, this compound has a good anti-cancer effect. [ABSTRACT FROM AUTHOR]

A new sustainable approach for the development of value added devulcanized rubber will augment its application in tire industry and play a significant role toward the product quality, production economy and market completion. The right choice of devulcanizing agent is carried out to keep in mind that the chemical will act as superior devulcanizing agent, easily available, low cost, smoothly penetrate into the crosslinked network in presence of carrier, multifunctional activity and eco‐friendly in nature. Consequently, the current research work is focused on the devulcanization of ground tire rubber (GTR) by way of a multifunctional devulcanizing agent, bis(3‐triethoxysilylpropyl)tetrasulfide. The uniqueness of the chemical agent is that it will devulcanize GTR mechanochemically and subsequently the so‐grown devulcanized rubber can facilitate the homogeneous silica dispersion into the revulcanized rubber compound. The degree of devulcanization and the devulcanized rubber quality is measured by the swelling experiment and Horikx theory. The experimental results clearly specified that the optimal devulcanization time is 40 min to obtain better‐quality of devulcanized rubber and enhanced mechanical and thermal performance of revulcanized rubber. The homogeneous silica dispersion in the rubber matrix is further supported by the scanning electron microscopy images. Ultimately, it was established that the as‐grown technology is suitable for rubber reclaiming, which provides to the advancement in the ecological sustainability. [ABSTRACT FROM AUTHOR]

In this investigation, incorporation of silica into natural rubber (NR)-reclaim rubber (RR) blend system was carried out by sol-gel technique at various sol-gel reaction temperatures. The effect of RR on silica reinforcement, hitherto unexplored, was studied for different NR/RR blend systems. The degree of reinforcement of sol-gel vulcanizates by equilibrium swelling method indicates that the reinforcing efficiency of the in situ generated silica by sol-gel technique increases with increasing reclaim rubber content. The reinforcing efficiency, tensile properties and thermal stability of sol gel vulcanizates (SGV) prepared at 50°C become maxima as compared to SGV prepared at 30°C and 70°C. The amount of silica incorporated by sol-gel technique was determined by thermogravimetry analysis. It indicates that the thermal stability increases with silica content. Attenuated total reflection study indicates that RR forms bond with silica particles due to the presence of active functional site on RR. Scanning electron microscopy studies further indicate the coherency and homogeneity in the silica filled NR/RR vulcanizates. The microwave diagnosis of different SGVs was also carried out and the frequency dependence of dielectric permittivity (E') and loss (E') were measured. POLYM. ENG. SCI., 53:227-237, 2013. © 2012 Society of Plastics Engineers, INTRODUCTION Reinforcement of elastomeric compounds, defined as the simultaneous enhancement of the elastic modulus and the elongation at break, by addition of particulate filler, is probably one of the most [...]

Mechanochemically devulcanized ground rubber tire (GRT) was (re)vulcanized in compositions with virgin natural rubber (NR). The NR/GRT (re)vulcanizates with GRT content from 20 to 60 wt% have been prepared and studied. Reclaiming of GRT was successfully carried out by tetra methyl thiuram disulfide (TMTD) in presence of spindle oil at around ambient temperature. The cure characteristics and mechanical properties of the virgin NR/reclaim GRT blend were studied. The optimum cure time decreases but scorch time remain unaltered with increasing reclaim rubber content in the blend. Effect of carbon black was studied in NR/RR (80/20) blend. Ageing characteristics of different NR/RR blends were evaluated. Scanning electron microscopy (SEM) studies further indicate the coherency and homogeneity in the NR/RR vulcanizate. The dynamic mechanical properties and swelling behavior of NR/RR blend vulcanizates were examined. The elastic and storage modulus of the NR/RR vulcanizates become improve with increasing reclaim rubber content. Electrical properties of NR/RR vulcanizates were also studied. POLYM. ENG. SCI., 47:1091-1100, 2007. © 2007 Society of Plastics Engineers, INTRODUCTION In the twenty-first century, recycling of waste materials is of growing importance for all the industries in the world. The automotive and transportation industries are the biggest consumers of [...]

Background: Different parts of Dillenia pentagyna have long been used in traditional medicines to cure several diseases including cancer. However, the mechanism(s) of anti-cancer effects are still unknown. We aimed to elucidate the anti-metastatic potential of ethanolic extracts of leaves of D. pentagyna (EELDP) and active fractions of it in highly metastatic human cancer cells. Methods: We screened different HPLC fractions of EELDP based on their anti-metastatic effect. We used TLC and ESI-MS for determining the presence of various phytochemicals in EELDP and fractions. We monitored in vitro anti-metastasis effect of EELDP (0-0.6 mg/ml) and active fractions (0-0.050 mg/ml) on various human cancer cells like A549, HeLa, and U2OS. Results: EELDP significantly reduced cell viability and cell migration in A549, HeLa, and U2OS cells. However, higher sensitivity was observed in A549 cells. We screened 2 active HPLC fractions F6 and F8 having anti-MMPs activity. EELDP and active fractions reduced metastasis via the NF-κB pathway, decreased the expression of Vimentin, N-cadherin, and increased the expression of Claudin-1. Conclusion: Significant reduction of metastasis by EELDP at a dose of 0.1 mg/ml or by active fractions at 0.050 mg/ml implicates that the active compound(s) present in crude or fractions are extremely potent to control highly metastatic cancer. [ABSTRACT FROM AUTHOR]

From an environmental and economic viewpoint, it is a win-win strategy to use materials obtained from renewable resources for the production of high-performance elastomer composites. Lignin, being a renewable biomass, was employed as a functional filler material to obtain an elastomer composite with a higher degree of mechanical performance. In the presence of a suitable coupling agent, an elevated temperature was preferred for the reactive mixing of lignin with polybutadiene rubber (BR). It is quite fascinating that the mechanical performance of this composite was comparable with carbon black-filled composites. The extraordinary reinforcing behavior of lignin in the BR matrix was understood by an available model of rubber reinforcement. In rubber composite preparation, the interfacial interaction between polybutadiene rubber and lignin in the presence of a coupling agent enabled the efficient dispersion of lignin into the rubber matrix, which is responsible for the excellent mechanical properties of the rubber composites. The rubber composites thus obtained may lead to the development of a sustainable and cost-effective end product with reliable performance. This novel approach could be implemented in other type of elastomeric materials, enabling a genuine pathway toward a sustainable globe. [ABSTRACT FROM AUTHOR]

Purpose: Radiotherapy using gamma ray is still the main therapeutic modality for the treatment of various cancers. However, local recurrence and increase of metastasis after radiotherapy is still a major therapeutic challenge. Aim of this work was to check cell migration along with activity and expression of some marker proteins involved in epithelial–mesenchymal transition (EMT) pathway in three different human cancer cells after exposure with gamma radiation in combination with PARP inhibitor olaparib. Materials and methods: Here, we presented cell viability, in vitro cell migration, activity of MMPs by gelatin zymography, expression of few EMT marker proteins and the signaling cascade involved in transcriptional regulation of MMPs after gamma irradiation with and without olaparib pretreatment in highly metastatic three human cancer cell lines—A549, HeLa and U2OS. Results: We observed that gamma irradiation alone increased in vitro cell migration, MMP-2,-9 activity, expression of N-cadherin, vimentin and the signaling molecules EGFR, ERK1/2, Akt, p38 that enhanced NF-kB expression in all three cell types. Olaparib treatment alone reduced in vitro cell migration along with reduction of expression of all the above-mentioned marker proteins of the EMT pathway. However, 4 h olaparib pretreatment prevented gamma ray induced activation of all these marker proteins in all three cell types. Conclusions: This data implicates that olaparib treatment in combination with gamma therapy could be promising in protecting patients from gamma-induced metastasis. [ABSTRACT FROM AUTHOR]

This article illustrates the reclaiming of guayule natural rubber (GNR) vulcanizate by bis[3-(triethoxysilyl)propyl] tetrasulfide (TESPT), and as-grown reclaim rubber facilitates the silica dispersion in GNR product application without adding any coupling agent. This article deals with the performance evaluation of silica-filled revulcanizates with promising application in green tire. The extent of reclaiming was monitored through the measurement of sol content, cross-link density, Mooney viscosity, and degree of reclaiming. The differential scanning calorimetry study was carried out to evaluate the fraction of immobilized polymer chains and its dependence on cross-link density of the vulcanizates. The Fourier transform infrared study and also sulfur analysis independently indicate the attachment of the fragmented TESPT with the polymer chain and cross-link bonds. The study of mechanical properties clearly shows that in revulcanized GNR, the optimum property is achieved when reclaiming time is set for 40 min. The effect of reclaiming time on dynamic mechanical behavior such as storage modulus and loss tangent was studied. The scanning electron microscopy studies show the coherency and homogeneity of silica-filled revulcanize rubber with reclaiming time. [ABSTRACT FROM AUTHOR]

Ethoxy functionalized devulcanize natural rubber (DeVulcNR) is used as compatibilizer for silica/graphene oxide (SiO2@GO) hybrid fillers in the styrene butadiene rubber (SBR) to fabricate SBR composites. The dispersion behavior of SiO2@GO hybrid filler was investigated through scanning electron microscopy (SEM) analysis of the tensile fracture surface along with the broken rubber surface developed by plunging into liquid nitrogen. The rubber–filler interfacial interactions were evaluated through the measurement of equilibrium swelling experiment, fraction of immobilized polymer chain by DSC study, FTIR analysis, and molecular dynamics simulation. The results reveal that in the presence of DeVulcNR, the rubber–filler interaction is enhanced compared with that of the control formulations containing only SBR. SiO2@GO hybrid‐filler shows synergistic effect on the mechanical properties of the composites in the presence of DeVulcNR. The improved mechanical properties of the SiO2@GO hybrid filler rubber composites may be due to chemical interaction among the functional groups of SiO2 and GO with the DeVulcNR. Further, XRD study indicates that there is no significant layer‐by‐layer restack of GO in the SBR/DeVulcNR composites. The higher storage modulus and lower tan δ of the SiO2@GO hybrid filler rubber composites show superior interfacial interaction between rubber and filler compared with that of the control formulations. POLYM. COMPOS., 40:E1559–E1572, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Mechanochemically devulcanized styrene‐butadiene rubber, prepared by bis[3‐(triethoxysilyl)propyl]‐tetrasulfide, was blended with fresh styrene‐butadiene rubber. The ultimate properties of the blend vulcanizate depend on a three‐dimensional network structure formed during vulcanization which relies mainly on the accelerator and the vulcanizing system used during compounding. The effect of monosulfide, disulfide, and poly sulfide cross‐links, which primarily gets controlled by different accelerators such as N‐cyclohexyl‐benzothiazyl‐sulfenamide (CBS), tetramethylthiuram disulfide, 2‐mercaptobenzothiazol, and N‐tert‐butyl‐2‐benzothiazyl‐sulfonamide on mechanical, thermal, and dielectric behavior of the blend vulcanizates, was studied. The results indicate that the semi‐efficient CBS vulcanizate has superior mechanical and thermal properties. Therefore, the effect of accelerator to sulfur ratio, that is, (accelerator/sulfur) on the properties of the blend vulcanizates was determined. It is to highlight that a distinctive correlation is observed between the cross‐link types and the fraction of immobilized polymer chains of the blend vulcanizates. Further, the effect of cross‐link types on segmental dynamics of the blend vulcanizates was studied through broadband dielectric spectroscopy. The SEM micrographs indicate the homogeneity of the blend vulcanizates. [ABSTRACT FROM AUTHOR]

Autoimmune hepatitis (AIH) and primary biliary cholangitis (PBC) are two major immune‐mediated chronic liver diseases. Overlap syndrome (OS) is diagnosed if patients have features of both AIH and PBC; however, there is no consensus on the definition or diagnostic criteria for OS. Here, we report a new scoring classification for OS and evaluate its usefulness. This new scoring classification was developed by modifying the International Autoimmune Hepatitis Group classification by selecting histologic features of AIH and PBC along with modifications of biochemical and immunologic characteristics. We evaluated 272 patients with chronic liver disease, including 105 with AIH, 102 with PBC, and 65 with OS. The best performance for the diagnosis of OS was noted among patients with an overlap score of ≥21 who had a sensitivity of 98.5%, a specificity of 92.8%, a positive predictive value of 81.0%, and a negative predictive value of 99.5%. By using a cut‐off score of 21, 64 (98.5%) patients were diagnosed with OS as opposed to 9 (8.8%) and 6 (5.7%) with PBC and AIH, respectively. All patients with OS had an aggregate score of >19, whereas most patients with PBC or AIH scored <19, making this a safe discriminatory cut‐off point against OS. Conclusion: The new scoring system for the diagnosis of OS has a high sensitivity and specificity for scores ≥21, while a score <19 suggests a diagnosis other than OS. This classification can identify patients and diagnose OS with a reasonable amount of accuracy and may be superior to current OS scoring systems in detecting mild forms of OS. (Hepatology Communications 2018;2:245‐253) [ABSTRACT FROM AUTHOR]

To study the silica content and its dispersion behavior in natural rubber (NR)-polybutadiene rubber (PBR)- reclaim rubber (RR)/SiO2 nanocomposites, scanning electron microscopy (SEM) images was used by image processing technique. A suitable algorithm was proposed to determine the silica percentage of the nanocomposites. Based on proposed algorithm, image analysis was carried out to present quantitative and qualitative measure of size distribution of silica (filler) agglomerates in the polymer nanocomposites. On the basis of stack based region detection algorithm, various sizes of silica particles was detected and 2D image was reconstructed through 10 different colors for 10 types of regions. This article also dealt with various aspects of the polymers such as filler-filler interaction, agglomerate detection, and dispersion of filler agglomerates through image analysis of their SEM micrographs. [ABSTRACT FROM AUTHOR]

We describe a case of a young male without stroke risk factors who presented with a sudden onset of left-sided weakness, left hand numbness, and left eye blurriness. CT scan of the head without contrast and diffusion-weighted MRI of the brain with contrast revealed an ischemic stroke in the right middle cerebral artery distribution. Transesophageal echocardiography (TEE) revealed a mobile pedunculated mass on the posterior surface of the mitral valve. This mass was resected and pathology showed a cardiac papillary fibroelastoma (CPFE), which was determined to be the cause of the patient’s cardioembolic stroke. Further workup also found that patient had microcytic anemia secondary to β-thalassemia intermedia, a rare hematologic disorder due to defective hemoglobin synthesis. Recently, another case report suggested β-thalassemia major may underlie the pathogenesis of CPFE. β-Thalassemia major causes a state of chronic inflammation and endothelial damage, which can mediate CPFE formation. Based on literature review, this is the first case report of a CPFE in a patient with β-thalassemia intermedia. This hypothesis-generating case report calls attention to the need for elucidating the relationship between CPFE and β-thalassemia in future studies to better understand the diagnosis and management of a rare cardiac tumor. [ABSTRACT FROM AUTHOR]

Hugh-Stovin Syndrome (HSS) is characterized by recurrent thrombophlebitis and multiple pulmonary and/or bronchial artery aneurysms indistinguishable from the cardiovascular features seen in Behcet's disease (BD). Our case describes a 30-year-old male with recurrent pulmonary embolism and bilateral pulmonary aneurysms. Autoimmune, hypercoagulable, and infectious work up were negative. Elevated inflammatory markers and absence of the typical clinical findings seen in BD led to the diagnosis of Hugh-Stovin syndrome (HSS). Immunosuppression using steroids and azathioprine led to clinical response. Anticoagulation was continued based on risk/benefit ratio. [ABSTRACT FROM AUTHOR]

Silica incorporation into natural rubber (NR)-polybutadiene rubber (PBR)-reclaim rubber (RR) ternary blend system was carried out by sol-gel technique at different temperatures. The effect of RR on silica reinforcement was studied for NR-PBR-RR blend systems. The physicochemical properties of sol-gel vulcanizates indicates that the reinforcing efficiency of the nanocomposites increases with increasing RR content. Sol-gel vulcanizates prepared at 50°Cshows superior mechanical properties than others. The amount of silica incorporated by sol-gel technique was determined through thermogravimetry analysis, which indicates the increasing trend of thermal stability with silica content. SEM studies indicate the coherency and homogeneity in the NR-PBR-RR/SiO2nanocomposites. [ABSTRACT FROM AUTHOR]

The article discusses a study which characterized the thermal behavior of grass fiber by thermogravimetric analysis and differential scanning calorimetry analysis. The effect of aging on the tensile strength of the grass fiber is examined. Findings suggest that the removal of water-soluble matter improved the thermal behavior of grass fiber over that of unleached fiber, and was further enhanced by an alkali treatment of the grass fiber.

There has been ever raising concern in last few decades about the utilization of biomass for different commercial applications such as filler materials in rubber composites. In this context, an interesting pathway has been proposed to develop such composites by introducing waste lignin as a reinforcing constituent in high cis-polybutadiene rubber (BR). With a judicious selection of rubber curing ingredients and, simultaneously, adopting suitable solid-state mixing protocols, particularly, a relatively high-temperature multi-steps melt-mixing process (above the glass transition temperature of lignin), rubber composites with an outstanding mechanical performance were prepared. The reinforced rubber composites with 50 (weight) parts lignin loading per hundred parts of rubber (phr) offer ∼10 MPa tensile strength (TS), ∼276% elongation at break (EB), and ∼3.51 MPa tensile stress at 100% elongation (so-called rubber modulus M 100). These values are superior when compared with the composites comprised with standard reinforcing carbon black (∼8.5 TS, ∼224% EB, ∼2.79 M 100) and even with a silica-silane system (∼7.34 TS, ∼229% EB, ∼2.44 M 100) with same filler loading. The unique combination of the curing packages and four-stage mixing process allowed us to establish a homogeneous and fine dispersion of lignin. Furthermore, this is the first time that available models of rubber reinforcement are applied to the description of the reinforcement mechanisms of lignin in a soft elastomer involving various aspects like filler-filler interaction, rubber-filler interactions, critical strains for destroying the filler-filler network, effective filler volume fractions, shape factor, etc. The developed compounding methods for BR and their characterization and modeling can be easily applied to other commercial rubbers facilitating a real breakthrough in developing cheap and bio-based high-performance rubber composites. [Display omitted] • Utilization of lignin as value added rubber reinforcing agent. • High temperature mixing of kraft lignin with polybutadiene rubber. • Comparison reinforcing capacity of different types of lignin. • Dispersion of lignin by use of coupling agent. • Comparable reinforcing ability of lignin with reinforcing carbon back. [ABSTRACT FROM AUTHOR]

In spite of advancement of pharmaceutical industry crude extract of medicinal plants are still reliable for treatment of various diseases and large number of people are still using this. India is rich in medicinal plants which have long been used in ayurvedic medicine for treatment of different diseases including cancer. Here we compared anti-metastatic property of ethanolic extract of leaf from an Indian medicinal plant on two different cancer cells a549 and hela. The cells were treated with different concentrations (0-0.6 mg/ml) of ethanolic extract of leaf for 24h to investigate pathways of anti-metastatic property. We did cell cytotoxicity, wound healing, Cell migration, zymography and expression of some metastasis related genes. We found that crude extract reduced cell migration, wound healing and mmp-2,-9 activity in a dose dependent manner. Expression of both mmp-2,-9 and its transcription factor nf-?? was decreased in both cell line after treatment. This data implicates that our crude extract inhibits metastasis via down-regulation of nf-?? followed by reduced expression of mmp-2,-9 and decrease of cell migration/invasion. Out of these two cell-types, we observed higher effect in A549 cells compared with hela. So, our crude extract reduces metastasis in both cells implicating that this crude extract is not cell-specific. Since our crude extract is effective at as low as 0.1 mg/ml, the active ingredient has a great extent to control highly metastatic cancer cells. [ABSTRACT FROM AUTHOR]

Devulcanized natural rubber (DeVulcNR) was produced from NR vulcanizate in an open roll mixing mill by using bis(3-triethoxysilyl propyl) tetrasulfide (TESPT), a novel devulcanizing agent. The versatility of the proposed devulcanizing agent TESPT is that it acts as a devulcanizing agent during devulcanization and as a coupling agent during dispersion of silica filler in devulcanize rubber compound. The extent of devulcanization was monitored through the measurements of sol content, gel content, crosslink density, molecular weight between crosslinks, Mooney viscosity of devulcanized rubber and degree of devulcanization as a function of devulcanization time and the concentration of TESPT. The study of extent of devulcanization by monitoring the above mentioned parameters clearly indicate that the optimum concentration of TESPT is 6 mL. Therefore, for further study DeVulcNR is prepared using 6 mL TESPT and designated as DeVulcNR-6 to optimize the devulcanization time. Determination of the fraction of immobilized polymer chains of DeVulcNR-6 by differential scanning calorimetry (DSC) study indicates that with sol content the fraction of immobilized polymer chains decreases due to increasing molecular weight between crosslinks. To get an idea about the application of DeVulcNR in product formulation revulcanization characteristics in the presence of silica filler were studied. The optimum cure time decreases whereas cure rate increases with devulcanization time. The mechanical properties e.g., modulus at 50% and 100% elongation, tensile strength and elongation at break increases with devulcanization time upto 40 min. To see the reinforcement of silica filler, the mechanical properties of ReVulcNR-6 with silica is compared to that of the ReVulcNR-6 without silica. The mechanical property and thermal behavior data clearly indicates that the optimum time for devulcanization is 40 min. Scanning electron microscopy (SEM) studies further show the coherency and homogeneity of DeVulcNR-6 in the revulcanizate when devulcanization is carried out by optimum TESPT concentration 6 mL and devulcanization time 40 min. [ABSTRACT FROM AUTHOR]

The report describes the synthesis, self-association and DNA binding studies of an aromatic tripeptide H-Phe-Phe-Phe-OH (FFF). The peptide backbone adopts β-sheet conformation both in solid and solution. In aqueous solution, FFF self-assembles to form nanostructured aggregates. Interactions of this peptide with calf-thymus DNA (ct-DNA) have been studied using various biophysical techniques including ultraviolet (UV) absorption spectroscopy, fluorescence spectroscopy and circular dichroism (CD) spectroscopy. The value of mean binding constant calculated from UV and fluorescence spectroscopic data is (2.914 ± 0.74) x 10 3  M -1 which is consistent with an external binding mode. Fluorescence intercalator displacement (FID) assay, iodide quenching study, viscosity measurement and thermal denaturation study of DNA further confirm the groove binding mode of peptide, FFF with ct-DNA. MTT cell survival assay reveals very low cytotoxicity of the peptide toward human lung carcinoma cell line A549.