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Aim: A minimally invasive surgery (MIS) extraperitoneal (XP) approach to left-sided colorectal resection utilizing the laparoscopic approach has recently been shown to be safe and feasible and to have potential advantages over the transperitoneal approach, especially in high-risk surgical patients. The aim of this article is to provide a first cadaveric demonstration of the use of a single-port robotic platform in performing XP low anterior resection by MIS., Method: A single-port robotic platform (DaVinci®SP™) was used to perform XP single-port low anterior resection in two cadavers with body mass indexes (BMIs) of 19 and 40 kg/m 2 ., Results: The single-port robotic platform with versatile arms was successfully used to perform a complete low anterior resection with splenic flexure mobilization and total mesorectal excision through a single port., Conclusions: A single-port robotic platform enhances complete XP dissection in the supine patient in extreme BMI ranges. Clinical studies are necessary to confirm these findings., (© 2024 Association of Coloproctology of Great Britain and Ireland.)

Objective: Our study aims to analyse and compare the efficacy, adverse effect profile and survival among the Paclitaxel/Cisplatin/5-Flurouracil (TPF) induction chemotherapy and Paclitaxel/carboplatin (PC) first line or cisplatin chemotherapy in a high-volume tertiary care cancer centre., Materials and Methods: 215 patients with oral cavity cancer were recruited in this study. Patients with stages I-IIc underwent surgical resection or radiation therapy 66-74 GY/fraction. Patients of Stages III-IV were administered with either induction chemotherapy TPF or PC or cisplatin regimen. Treatment responses were assessed by CT and MRI. Response rates, survival and adverse effects data were tabulated and analysed., Results: The mean age was 49.2 ± 11.68 years. Symptoms were ulceration (33.5%), growth (20.5%), pain (13%), ulcer-proliferative growth (8.4%) and swelling (13, 6%). The tumour site was found at the base of the tongue, C01 (42.2%) followed by C06 (35.8%), C08 (6.5%), C07 (5.2%) and C05 (4.6%). There were no significant differences ( P > 0.05) in efficacy and survival outcomes between the different groups of treatment. Median survival was achieved within 36 months. The major side effect observed were anaemia (15.81%), diarrhoea (36.2%), dyspepsia (28.8%), fever (33.95%), mucositis (28.85%), myalgia (33.95%) and nausea (7.9%). Survival among the responder categories (CR, PR and NR) was significantly different as per Log-rank analysis ( P = 0.015)., Conclusions: TPF induction therapy and PC first line chemotherapy showed similar efficacy, safety profile and survival whereas cisplatin shows poor efficacy and safety and survival in Indian oral cancer patients., (Copyright © 2024 Copyright: © 2024 Journal of Cancer Research and Therapeutics.)

Gamma-papillomaviruses, though traditionally classified as cutaneotropic, actual tissue tropism is largely unexplored. This study aimed to evaluate the tissue-specific prevalence of two novel-HPV 223 and 225 in samples of oral mucosa and keratinized epithelium of varied skin parts from 226 female and male subjects, with or without neoplastic/dysplastic lesions in oral cavity or cervix. The gamma-human papillomavirus (gamma-HPV) 223 and 225 DNA presences were determined by polymerase chain reaction (PCR) ursing the HPV type-specific primers and confirmed by Sanger sequencing. Viral load in the HPV 223 and HPV 225 positive samples were determined by absolute real-time quantification method. Alpha-HPV DNA prevalence was also checked in oral mucosa to ascertain coinfection status. Novel HPV 223 was present in 4.4% (10/226) oral mucosal samples of the study population; interestingly all were females with no prevalence in their corresponding skin swab samples. Whereas, the prevalence of HPV 225 was found both in the skin and oral mucosa of 28.2% (N = 37/131) female and 17.9% (N = 17/95) male participants. Alongside, HPV 223 viral load was found to be significantly higher (p = 0.02 < 0.05) in the oral mucosa of diseased participants, whereas, HPV 225 viral load was higher in the oral mucosa of normal participants. Our results suggest that gamma-HPV 223 has its prevalence only in the oral mucosal epithelium, whereas, HPV 225 has its prevalence on both mucosal and keratinized skin epithelium, indicating its dual tropism nature., (© 2023 Wiley Periodicals LLC.)

Introduction: Technical challenges during laparoscopic and robotic anterior resection include identification of key retroperitoneal structures and obtaining clear views of the inferior mesenteric artery (IMA) pedicle and total mesorectal excision (TME) plane. Steep head-down position improves surgical exposure but is associated with cerebral oedema, high intrapulmonary pressures, and rare neurological complications. In this article we describe the key steps of an anterior resection performed via the extra-peritoneal (XP) space in the supine position., Methods: The technique of same-side lateral-to-medial XP dissection has been developed and refined in serial cadaveric workshops. A standard periumbilical port is inserted for initial laparoscopic exploration. Dissection is then performed in the left XP space via a 5 cm skin incision (later used as the extraction site) to allow for insertion of four (latterly three) working ports. The colon is mobilized along its lateral attachments, reflecting retroperitoneal structures down and away. The IMA pedicle is taken proximally, next to the duodenum. If required, TME dissection can be continued in the same plane. A short intraperitoneal phase is then required to complete the procedure., Results: Eight cadavers were studied (seven males; median 78 y). Four operations were performed laparoscopically and four robotically. Excellent views of the key retroperitoneal structures were achieved early in the procedure. Anatomical identification was performed sequentially for left-sided structures-psoas tendon, gonadal vessel, ureter, common iliac artery, IMA, and duodenum before ligation of the IMA pedicle. High ligation of IMA on the aorta and splenic flexure mobilization were performed in all eight procedures., Conclusions: This novel study shows it is feasible to perform the key steps of an anterior resection using the XP space in the supine position. This will reduce the need for steep head-down positioning which may have meaningful clinical benefits. Prospective clinical studies are required to validate the technique within a patient population., (Crown Copyright © 2022. Published by Elsevier Inc. All rights reserved.)

For the correction of defocus and astigmatism, mechanical approaches are well known, but there is a need for a non-mechanical, electrically tunable optical system that could provide both focus and astigmatism power correction with an adjustable axis. The optical system presented here is composed of three liquid-crystal-based tunable cylindrical lenses that are simple, low cost, and having a compact structure. Potential applications of the concept device include smart eyeglasses, virtual reality (VR)/ augmented reality (AR) head-mounted displays (HMDs), and optical systems subject to thermal or mechanical distortion. Details of the concept, design method, numerical computer simulations of the proposed device, as well as characterization of a prototype, are provided in this work.

Background: Current transperitoneal approaches to colorectal resections can be technically challenging, especially in obese patients. The head-down position can lead to rare but serious complications, e.g. compartment syndrome and brachial plexus injuries., Objective: The aim of this study was to assess the safety and feasibility of a novel extraperitoneal approach in patients requiring anterior resection., Methods: The extraperitoneal left-sided approach was performed in the supine position. A 5 cm LIF incision was created into which a Gelpoint port was inserted. The full video of the procedure is embedded in the QR code below. The procedure was performed by three surgeons with experience in minimally invasive surgery. Patients requiring left colonic resections were prospectively selected over a 2-year period., Results: Forty-one patients were prospectively assessed between March 2020 and April 2022; 26 were males, with a median age of 67 (55-88) years. The average body mass index (BMI) was 30 (22-40). 38/41 cases were cancers and three were diverticular diseases; 31 cases had anterior resection and 11 had sigmoid colectomies. Peak airway pressures were significantly less (10 cmH20) in the supine position compared with the head-down position (p < 0.0001). Median time to identify the ureter and gonadal vessels was 23 (3-55) min, and median time to return of bowel function and length of stay was 2 (0-13) and 5 (IQR 3-7) days, respectively. No intraoperative complications or postoperative mortality occurred within 90 days of discharge. Three patients had anastomotic complications, and an R0 resection was achieved in all 38 cancer patients. The median lymph node count was 16., Conclusion: Extraperitoneal surgery for left colonic resections is safe and clinically feasible, and allows for early identification of important retroperitoneal structures., (© 2022. Society of Surgical Oncology.)

The key feature of the present work is the dexterous utilization of an apparently destructive process, pyrolysis, for the synthesis of the most esteemed nanomaterial, graphene. This work is an attempt to synthesize graphene from nonconventional sources such as tannic acid, alginic acid, and green tea by a controlled pyrolysis technique. The precursors used in this work are not petroleum-derived and hence are green. A set of pyrolysis experiments was carried out at different temperatures, followed by a thorough step-by-step analysis of the product morphology, enabling the optimization of the graphitization conditions. A time-dependent morphological analysis was also carried out along with isothermal thermogravimetric studies to optimize the ideal pyrolysis time for graphitization. The specific capacitance of the graphene obtained from alginic acid was 315 F/g, which makes it fairly suitable for application as green supercapacitors. The same graphene was also used to fabricate a rubber-latex-based flexible supercapacitor film with 137 F/g specific capacitance. The graphene and graphene-based latex film exhibited room-temperature magnetic hysteresis, indicating their ferromagnetic nature, which also supports their spintronic applications., Competing Interests: The authors declare no competing financial interest., (© 2021 American Chemical Society.)

Presbyopia is the failure of the eye lens to accommodate. The widely used presbyopia correction method involves wearing bi/trifocal or progressive glasses, which limits the field of view due to division of lens area into sections of different optical power. A large aperture focus tunable liquid crystal lens has the potential to correct human eye accommodation failure and provide a wide field of view. In this paper, we present characterization and demonstration of a segmented phase profile liquid crystal lens, which has the characteristics of a large area (diameter: 20 mm), being flat and thin (<2 mm), and having continuous focus tunability (1.5 D to 0 D), fast response time (<500 ms), low operating voltage (<5 V), and on-axis diffraction-limited performance (for a 5mm aperture). Considering all these properties, our lens provides performance details of an approach for presbyopia correction. We have tested the minimum resolution and visual acuity of 20 subjects using the designed lens and compared the results with a reference glass lens of the same optical power.

Polydimethylsiloxane (PDMS) polymers are highly appreciated materials that are broadly applied in several industries, from baby bottle nipples to rockets. Momentive researchers are continuously working to understand and expand the scope of PDMS-based materials. Fluorofunctional PDMS has helped the world to apply in specialty applications. Efforts are taken to develop such siloxane-fluoropolymer composite materials with good thermal, solvent, and chemical resistance performances. We leveraged inherently flexible PDMS as the model matrix, whereas polytetrafluoroethylene (PTFE) was used as the additive to impart the functional benefits, offering great value in comparison to the individual polymers. The composites were made at three different mixing temperatures, that is, 0-35 °C, and different loadings of PTFE, that is, 0.5-8% (w/w), were selected as the model condition. A strong dependency of the mixing temperature against the performance attributes of the developed composites was noted. Mechanical and thermal stability of the composites were evaluated along with optical properties. X-ray diffraction demonstrated the change in the crystallite size of the PTFE particles as a function of processing temperature. Compared to the phase II crystallite structure of the PTFE, the fibrils formed in phase IV imparted a better reinforcing capability toward the PDMS matrix. A synergistic balance between higher filler loading and mechanical properties of the composite can be achieved by doping the formulation with short-chain curable PDMS, with 238% increment of tensile strength at 8 wt % PTFE loading when compared to the control sample. The learning was extended to check the applicability of doping such PTFE powder in commercial liquid silicone rubber (LSR). In the window of study, the formulated LSR demonstrated improved mechanical properties with additional functional benefits like resistance toward engine oil and other chemical solvents., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)

In locally advanced cases of carcinoma larynx, which are being treated with total laryngectomy, routine excision of the thyroid gland (either total or hemi section) is carried out. This study was carried out to evaluate the requirement of routine thyroidectomise with total laryngectomy. An analysis of the final histology of 83 patients, who underwent the traditional treatment, together with the preoperative contrast enhanced CT scan was carried out. Among 58 cases of T3 carcinoma larynx 2 revealed thyroid involvement by metastasis (3.45%), 1 of them was suspected in preoperative CT and confirmed by FNAC. Among 25 cases of T4a carcinoma larynx 6 revealed thyroid involvement by direct extension (24%) with evidence of same in preoperative CT. Risk of thyroid involvement is low in T3 cases (3.45%) and is by metastasis. Risk of thyroid involvement is higher in T4a cases (24%) and is by direct extension. Preoperative CECT is a good tool to predict thyroid gland involvement either by metastasis or by direct spread. This study thus raises doubts about the requirement of routine thyroidectomise in association with total laryngectomies in advanced carcinoma larynx. We thus believe that further investigations, on a larger scale and multi-institutional, is warranted., Competing Interests: Conflict of interestThe authors declare that they have no conflict of interest., (© Association of Otolaryngologists of India 2019.)

Supernovae and their remnants are a central problem in astrophysics due to their role in the stellar evolution and nuclear synthesis. A supernova's explosion is driven by a blast wave causing the development of Rayleigh-Taylor and Richtmyer-Meshkov instabilities and leading to intensive interfacial mixing of materials of a progenitor star. Rayleigh-Taylor and Richtmyer-Meshkov mixing breaks spherical symmetry of a star and provides conditions for synthesis of heavy mass elements in addition to light mass elements synthesized in the star before its explosion. By focusing on hydrodynamic aspects of the problem, we apply group theory analysis to identify the properties of Rayleigh-Taylor and Richtmyer-Meshkov dynamics with variable acceleration, discover subdiffusive character of the blast wave-induced interfacial mixing, and reveal the mechanism of energy accumulation and transport at small scales in supernovae., Competing Interests: The authors declare no conflict of interest.

Sepiolite nanoclay needles have been selectively localized either in the natural rubber (NR) phase or in the carboxylated nitrile rubber (XNBR) phase of the XNBR/NR (50/50) blend prepared by the solution casting method. In a systematic manner, the role of the difference value between the interaction parameter of individual blend components (NR or XNBR)/solvent and the interaction parameter of sepiolite nanoclay/solvent in selectively localizing the sepiolite nanoclay to the NR phase or the XNBR phase of the XNBR/NR (50/50) blend has been explored. A higher percentage of sepiolite nanoclay resides in the dispersed NR phase when the difference value between the interaction parameter of NR/solvent and the interaction parameter of sepiolite nanoclay/solvent is lower than the difference value between the interaction parameter of XNBR/solvent and the interaction parameter of sepiolite nanoclay/solvent. On the other hand, a higher percentage of sepiolite nanoclay resides in the continuous XNBR phase when the difference value between the interaction parameter of XNBR/solvent and the interaction parameter of sepiolite nanoclay/solvent is lower than the difference value between the interaction parameter of NR/solvent and the interaction parameter of sepiolite nanoclay/solvent. It has been shown that by judiciously choosing different solvent combinations to prepare the blend and to disperse nanoclay, it is possible to fine-tune the difference value between the interaction parameter of individual blend components (NR or XNBR)/solvent and the interaction parameter of sepiolite nanoclay/solvent and dictate the selective localization of sepiolite nanoclay to the NR phase or the XNBR phase of XNBR/NR (50/50) blend. This study shows that it is possible to generate a rubber blend with controlled properties by selectively localizing needlelike sepiolite nanoclay in the dispersed phase or the continuous phase of the rubber blend prepared by the solution casting method., Competing Interests: The authors declare no competing financial interest.

Purpose: The tumor suppressor protein p53 is known to control cell cycle arrest and apoptosis. Lupeol is a phytochemical that has been found to induce apoptosis in different cancer types through the extrinsic pathway. As yet, however, its role in the induction of cell cycle arrest and apoptosis through the intrinsic pathway in head and neck cancer has not been investigated. Here, we aimed at understanding the mechanism underlying the antitumor effect of Lupeol in head and neck cancer., Methods: The antitumor effect of Lupeol on oral and laryngeal carcinomas was assessed using two in vitro 2D cell line models (HEp-2, UPCI:SCC-131) and, subsequently, an ex vivo 3D tumor explant culture platform that maintains key features of the native tumor microenvironment. The mechanism underlying Lupeol-mediated antitumor responses was delineated using MTT, colony formation, flow cytometry, immunofluorescence, Western blotting and immunohistochemistry assays., Results: We found that Lupeol induced an enhanced expression of p53 in both cell line models tested and, subsequently, cell cycle arrest at the G1 phase. In addition we found that, following Lupeol treatment, p53 induced Bax expression and activated the intrinsic apoptotic pathway (as measured by Caspase-3 cleavage). Interestingly, Lupeol was also found to trigger G1 cell cycle arrest through up-regulation of the expression of CDKN2A, but not p21, resulting in inhibition of CyclinD1. In an ex vivo platform Lupeol was found to impart a potent antitumor response as defined by inhibition of Ki67 expression, decreased cell viability and concomitant activation (cleavage) of Caspase-3. Finally, we found that Lupeol can re-sensitize primary head and neck squamous cell carcinoma (HNSCC) tumor samples that had clinically progressed under a Cisplatin treatment regimen., Conclusion: Together, our data indicate that Lupeol may orchestrate a bifurcated regulation of neoplastic growth and apoptosis in head and neck cancers and may serve as a promising agent for the management of tumors that have progressed on a platinum-based treatment regimen.

The processing of abasic site DNA damage lesions in extracellular DNA in the presence of engineered carbon nanomaterials (CNMs) is demonstrated. The efficacy of the apurinic-apyrimidinic endonuclease 1 (APE1) in the cleavage of abasic site lesions in the presence of carboxylated multi-walled carbon nanotubes (MWCNT-COOH) and graphene oxide (GO) are compared. The CNMs were found to perturb the incision activity of APE1. The reason for such perturbation process was anticipated to take place either by the non-specific adsorption of APE1 over the free surface of the CNMs or steric hindrance offered by the CNM-DNA complex. Accordingly, bovine serum albumin (BSA) was selectively utilized to block the free surface of the CNM-DNA hybrid material. Further treatment of the CNM-DNA-BSA complex with APE1 resulted in a marginal increase in APE1 efficiency. This indicates that APE1 in solution is unable to process the abasic sites on DNA adsorbed over the CNMs. However, the cleavage activity of APE1 was restored in the presence of non-ionic surfactant (Tween 20) that inhibits adsorption of the DNA on the surface of the CNMs. The conformational deformation of the DNA, along with steric hindrance induced by the CNMs resulted in the inhibition of abasic site DNA repair by APE1. Moreover, appreciable changes in the secondary structure of APE1 adsorbed over the CNMs were observed that contribute further to the repair refractivity of the abasic sites. From a toxicological viewpoint, these findings can be extended to the study of the effect of engineered nanoparticles in the intracellular DNA repair process., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Grafting of high molecular weight polymers to graphitic nanoplatelets is a critical step toward the development of high performance graphene nanocomposites. However, designing such a grafting route has remained a major impediment. Herein, we report a " grafting to " synthetic pathway by which high molecular weight polymer, poly(ε-caprolactone) (PCL), is tethered, at high grafting density, to highly anisotropic graphitic nanoplatelets. The efficacy of this tethering route and the resultant structural arrangements within the composite are confirmed by neutron and X-ray scattering measurements in the melt and solution phase. In the semicrystalline state, X-ray analysis indicates that chain tethering onto the graphitic nanoplatelets results in conformational changes of the polymer chains, which enhance the nucleation process and aid formation of PCL crystallites. This is corroborated by the superior thermal properties of the composite, manifested in accelerated crystallization kinetics and a significant increase in the thermal degradation temperature. In principle, this synthesis route can be extended to a variety of high molecular weight polymers, which can open new avenues to solution-based processing of graphitic nanomaterials and the fabrication of complex 3D patterned graphitic nanocomposites.

Epidermal growth factor receptor (EGFR) and its downstream elements are overexpressed in most cases of the head and neck squamous cell carcinoma. This study investigated the expression pattern of key proteins linked to the EGFR pathway in laryngeal carcinoma patients with a history of cannabis smoking. We selected 83 male glottic cancer patients, aged between 45 to 75 years with three distinct populations-nonsmoker, cigarette smoker, and cannabis smoker. Immunohistochemical staining was performed for EGFR, protein kinase B (PKB or Akt), nuclear factor kappa B p50 (NF-КB), and cyclooxygenase-2 (COX-2) followed by boolean scoring for statistical analysis. Experimental data showed upregulation of the selected EGFR cascade in tumor cells, stromal expression of EGFR, and nuclear localization of COX-2 in metaplastic gland cells of laryngeal cancer tissue sample. Statistical analyses indicated that overexpression of the EGFR cascade is significantly correlated to cannabis smoking. Cannabis smokers had higher expression (p < 0.01) of these onco-proteins with respect to both nonsmokers as well as cigarette smokers. Risk factor analysis showed high risk of these proteins expression in age <60 years (odds ratio (OR) > 1.5) as the lower age group had relatively higher number of cannabis smokers. This study provides evidence for a direct association between cannabis smoking and increased risk of laryngeal cancer. Higher expression of the EGFR cascade in cannabis smokers revealed that cannabis smoking may be a major cause for the early onset of aggressive laryngeal cancer.

Single-stranded DNA-melamine hybrid molecular building blocks were synthesized using a phosphoramidation cross-coupling reaction with a zero linker approach. The self-assembly of the DNA-organic hybrid molecules was achieved by DNA hybridization. Following self-assembly, two distinct types of nanostructures in the form of linear chains and network arrays were observed. The morphology of the self-assembled nanostructures was found to depend on the number of DNA strands that were attached to a single melamine molecule.

A novel tyrosine-based copolymer containing l-tyrosine (Tyr) and diglycidylether of bisphenol A(DGEBA) was synthesized and studied for its interaction with DNA for potential applications in biological systems. The synthesis of the polymer was optimized by varying monomer ratios using 4-(dimethylamino)pyridine (DMAP) as a catalyst to yield polymers with a M w of 7500-8000. Further characterization by FTIR, NMR and thermal analysis supported the formation of the monotyrosine-DGEBA polymer. The interaction of the 1 : 1 DGEBA-tyrosine copolymer with DNA was investigated by gel electrophoresis, thermal melting, and fluorescence spectroscopy in ratios ranging from 0.5 : 1 to 12 : 1 polymer-DNA (w/w). The copolymer was seen to lend stability to the DNA without damaging it and demonstrated endonuclease resistivity that is conducive for biological applications. Scanning electron microscopy, dynamic light scattering and zeta potential studies of the polymer-DNA complex also established that the polymer is capable of encapsulating DNA leading to the formation of the DNA-polymer polyplex nano-assembly. The potential of the polymer for biological applications was further reinstated by its non-cytotoxicity.

The efficiency of the apurinic/apyrimidinic endonuclease (APE1) DNA repair enzyme in the processing of abasic site DNA damage lesions at precise location in DNA oligomer duplexes that are adsorbed on clay surfaces was evaluated. Three different forms of clay namely montmorillonite, quaternary ammonium salt modified montmorillonite and its boiled counterpart i.e. partially devoid of organic moiety were used for a comparative study of adsorption, desorption and DNA repair efficiency on their surfaces. The interaction between the DNA and the clay was analysed by X-ray diffraction, Atomic force microscopy, UV-Vis spectroscopy and Infrared spectroscopy. The abasic site cleavage efficiency of APE1 enzyme was quantitatively evaluated by polyacrylamide gel electrophoresis. Apart from the difference in the DNA adsorption or desorption capacity of the various forms of clay, substantial variation in the repair efficiency of abasic sites initiated by the APE1 enzyme on the clay surfaces was observed. The incision efficiency of APE1 enzyme at abasic sites was found to be greatly diminished, when the DNA was adsorbed over organomodified montmorillonite. The reduced repair activity indicates an important role of the pendant surfactant groups on the clay surfaces in directing APE1 mediated cleavage of abasic site DNA damage lesions., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A "grafting to" methodology for the attachment of a silane based polymer (SG) onto functionalized graphitic platelets is demonstrated. The siloxy end groups of the modifier were further cross-linked without addition of any external curative. These sterically stabilized nanoplatelets with a high grafting density ensured complete screening of the attractive interparticle interactions. As a result, a better dispersion of platelets was observed compared to the physically mixed platelets in the polymer matrix (SUG). The larger size of the polymer tethered graphitic particles and the greater extent of heat liberated due to grafting resulted in a higher enthalpic contribution in the case of SG compared to SUG. This makes the formation of SG thermodynamically more favorable compared to SUG. Presence of a hierarchical spatial arrangement with a good dispersion of graphitic platelets was observed within the siloxane matrix in the case of SG compared to SUG. The nanoparticle tethered composite generated exhibited an "instant" conducting adhesive behavior. The adhesive properties of the SG were found to be increased due to grafting of graphitic platelets when compared with the neat polymer. Further, SG exhibited a conductive character whereas the neat polymer and SUG demonstrated an insulating character.

The generation of stress in expanded graphite (E-GPT) due to covalent attachment of bulky side groups connected via a hetero atom is reported. Specifically, E-GPT is modified at different levels of grafting using "click" chemistry to graft 1-ethynyl-4-fluoro benzene onto graphene sheets via a triazole ring. In the range of grafting densitites examined, Raman spectroscopy indicates that the stress generated in graphene is linearly dependent on the extent of grafting. The functionalized graphene platelets with 6% functionalization transform from semi-metal behavior of the pristine material to semi-conductor behavior and indicates the ability of functionalization to change optical and electronic properties of graphene platelets similar to the deposition of thin layers of top gate oxides onto graphene.

Content of tumor microenvironment (TME) is varied greatly among different types of laryngeal tumors, namely, supraglottic, glottic and subglottic tumors. These three different TMEs shape infiltrating monocytes/macrophages toward M2 genotypes in variable degrees. Results obtained from in vitro studies demonstrated extent of expression of M2 phenotypic features on macrophages was maximum after their exposure to supraglottic laryngeal tumor cell lysates (SLTCL) than glottic or subglottic lysates. Moreover, M2 macrophages generated under influence of SLTCL show less nitric oxide production, greater IL-10: IL-12 ratio and poor antigen presentation. Co-culture of such M2 macrophages with T cells from healthy donors resulted decreased activation of T cells and T cell mediated tumor cell cytotoxicity, than, glottic or subglottic. SLTCL mediated macrophage polarization is STAT3 dependent and might be one of the major factors for severe immune paralysis leading to poor prognosis of supraglottic laryngeal tumor bearer following standard treatment., (Copyright © 2013 Elsevier B.V. All rights reserved.)

Unlike conventional routes by van der Waals forces, a facile and novel approach using covalent bonding is established in the present work to synthesize polyaniline (PANI)-grafted carbon nanofiber (CNF) composites as promising supercapacitors. For this purpose, toluenediisocyanate was initially functionalized to carboxylated CNF via amidation followed by reaction with excess aniline to form a urea derivative and residual aniline, which was subsequently polymerized and grafted with a urea derivative. Amidation of CNF (TCNF) and, consequently, the grafting of PANI on TCNF were verified by IR, Raman, 1H NMR, X-ray photoelectron, and UV-visible spectroscopic methods, X-ray diffraction, and thermogravimetric analysis. Morphological analysis revealed uniform distribution of PANI on the surface of TCNF, indicating strong interaction between them. Electrochemical tests of the composite containing 6 wt % TCNF demonstrated efficient capacitance of ∼557 F g(-1) with a capacity retention of 86% of its initial capacitance even after 2000 charge-discharge cycles at a current density of 0.3 A g(-1), suggesting its superiority compared to the materials formed by van der Waals forces. The remarkably enhanced electrochemical performance showed the importance of the phenyl-substituted amide linkage in the development of a π-conjugated structure, which facilitated charge transfer and, consequently, made it attractive for efficient supercapacitors.

Bionanowhiskers were extracted from jute by acid hydrolysis. At first cellulose microfibrils were formed by alkali treatment. Addition of an acid to the microfibrils triggered the formation of cellulose nanowhiskers. These were characterized by using different techniques viz. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetry (TGA), scanning electron microscopy (SEM) and atomic force microscopy (AFM). In the FTIR study, absence of peak at 1738 cm(-1) indicated removal of hemicellulose. The rod like morphology of the nanowhiskers (length - 550±100 nm, width - 77±30 nm) was observed after 1h of acid hydrolysis, whereas further increase in time resulted in triangular shape morphology. Acid hydrolysis increased crystallinity, but decreased the temperature corresponding to major degradation (T(max)) and onset of degradation (T(i)). These bionanowhiskers might be useful as reinforcing element in nanocomposites., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Structure of nanofillers and their subsequent interaction with a polymer is very important in determining thermal stability of polymer nanocomposite. In this paper, we tried to correlate structure of various 0, 1 and 2 dimensional nanofillers with the thermal stability of hydrogenated nitrile butadiene rubber (HNBR) nanocomposites. Organically modified and unmodified layered silicates such as montmorillonite (Cloisite Na+, Cloisite 30B and Cloisite 15A), rod-like fibrous filler (sepiolite) and spherical nanoparticles (nanosilica) were chosen for this purpose. A significant improvement in thermal stability (obtained by thermogravimeric analysis and differential scanning calorimetry) was observed for silica-filled nanocomposites. However, the activation energy of the nanocomposites calculated by different kinetic methods (both non-isothermal and isothermal methods) was found to be significantly high for sepiolite, 30B and silica-filled nanocomposites. The results were explained with the help of structure of the nanofillers, their interaction with the elastomer and the subsequent dispersion, as measured by X-ray diffraction, transmission electron microscopy and atomic force microscopy. From these analyses it was concluded that organically modified montmorillonite, sepiolite and nanosilica increase the thermal stability of the nanocomposite to a great extent due to the interaction of the reactive groups on the surface of these fillers with the polymer and high thermal stability of these inorganic fillers. Finally, degradation mechanism of HNBR in presence of the nanofillers at severe operating temperatures was investigated with the help of FTIR spectroscopy.

The aim of this research was to synthesize magnesium oxide nanoparticles and to use them as cure activator for polychloroprene rubber (CR). The effects of counterions of magnesium salts on the homogeneous phase precipitation reaction to control size, monodispersity, crystallinity, and morphology of Mg(OH)2 nanoparticles were also investigated. Magnesium oxide nanoparticles were synthesized by optimizing the calcination temperature of Mg(OH)2 nanoparticles. Finally, the MgO nanoparticles were dispersed in polychloroprene rubber (CR) solution along with zinc oxide (ZnO) powder. The influence of MgO nanoparticles on the mechanical, dynamic mechanical and thermal properties of the resulting nanocomposites was quantified. The modulus and strength of ZnO-cured polychloroprene rubber with 4% MgO nanoparticles appeared to be superior to those with ZnO particles or ZnO with rubber grade MgO particles. These composites were further characterized by transmission electron microscopy and infrared spectroscopy in order to understand the morphology of the resulting system and the load transfer mechanism.

A series of ethylene vinyl acetate (EVA) nanocomposites using four kinds of EVA with 40, 50, 60, and 70 wt% vinyl acetate (VA) contents and three different carbon-based nanofillers-expanded graphite (EG), multi-walled carbon nanotube (MWCNT), and carbon nanofiber (CNF) have been prepared via solution blending. The influence of the matrix polarity and the nature of nanofillers on the morphology and properties of EVA nanocomposites have been investigated. It is observed that the sample with lowest vinyl acetate content exhibits highest mechanical properties. However, the enhancement in mechanical properties with the incorporation of various nanofillers is the highest for EVA with high VA content. This trend has been followed in both dynamic mechanical properties and thermal conductivity of the nanocomposites. EVA copolymer undergoes a transition from partial to complete amorphousness between 40 and 50 wt% VA content, and this changes the dispersion of the nanofillers. The high VA-containing polymers show more affinity toward fillers due to the large free volume available and allow easy dispersion of nanofillers in the amorphous rubbery phase, as confirmed from the morphological studies. The thermal stability of the nanocomposites is also influenced by the type of nanofiller.

Use of sulfur crosslinked nanogels to improve various properties of virgin elastomers was investigated for the first time. Natural rubber (NR) and styrene butadiene rubber (SBR) nanogels were prepared by prevulcanization of the respective rubber lattices. These nanogels were characterized by dynamic light scattering, atomic force microscopy (AFM), solvent swelling, mechanical, and dynamic mechanical property measurements. Intermixing of gel and matrix at various ratios was carried out. Addition of NR gels greatly improved the green strength of SBR, whereas presence of SBR nanogels induced greater thermal stability in NR. For example, addition of 16 phr of NR gel increased the maximum tensile stress value of neat SBR by more than 48%. Noticeable increase in glass transition temperature of the gel filled systems was also observed. Morphology of these gel filled elastomers was studied by a combination of energy dispersive X-ray mapping, transmission electron microscopy, and AFM techniques. Particulate filler composite reinforcement models were used to understand the reinforcement mechanism of these nanogels. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s11671-009-9262-5) contains supplementary material, which is available to authorized users.

Novel polyurethane nanocomposites based on toluene diisocyanate, poly(propylene glycol), various hyperbranched polymers (HBPs), and layered silicate were synthesized with the aim of determining the effect of the layered silicate loading and the functionality of HBP on the structure and properties of polyurethane nanocomposites. The microstructure of the nanocomposites was investigated by X-ray diffraction analysis and high-resolution transmission electron microscopy. It was found that exfoliated morphology and good dispersion were obtained up to 8 phr clay loading for all of the nanocomposites. approximately 100% increment in tensile strength, approximately 2-fold increase in the lap shear strength, approximately 200% increment in the peel strength, and 120% increment in the storage modulus along with a dramatic improvement in thermal stability were observed with the addition of 8 phr clay, over the pristine polyurethane. The higher the level of functionality of the HBP, the higher is the property enhancement. These properties were correlated with the state of dispersion of the clay platelets in the polyurethane matrix, the structure of the matrix, and clay-polymer interaction.

Carbon nanofiber (CNF) is one of the stiffest materials produced commercially, having excellent mechanical, electrical, and thermal properties. The reinforcement of rubbery matrices by CNFs was studied in the case of ethylene vinyl acetate (EVA). The tensile strength was greatly (61%) increased, even for very low fiber content (i.e., 1.0 wt.%). The surface modification of the fiber by high energy electron beam and gamma irradiation led to better dispersion in the rubber matrix. This in turn gave rise to further improvements in mechanical and dynamic mechanical properties of EVA. The thermal conductivity also exhibited improvements from that of the neat elastomer, although thermal stability of the nanocomposites was not significantly altered by the functionalization of CNFs. Various results were well supported by the morphological analysis of the nanocomposites.

Reinforcement of a novel poly(phenylene ether) (PPE) based thermoplastic elastomer (TPE), i.e., styrene-ethylene-butylene-styrene (SEBS)/ethylene vinyl acetate (EVA) and PPE-polystyrene (PS), was studied to develop a reinforced thermoplastic elastomer or thermoplastic vulcanizate (TPV). An effort was made to reinforce selectively the elastomeric dispersed phase of EVA by silica nanoparticles and silica sol-gel precursors, like alkoxy orthosilanes, using twin-screw extrusion and injection molding processes. Improvement of tensile strength and percent elongation at break was observed both with silica nanoparticles and tetraethoxy orthosilane (TEOS). Addition of TEOS transformed the dispersed EVA lamellar morphology into semispherical domains as a consequence of possible crosslinking. Soxhlet extraction was done on the silica and TEOS reinforced materials. The insoluble residues collected from both the silica and TEOS reinforced samples were analyzed in detail using both morphological and spectroscopic studies. This extensive study also provided an in-depth conceptual understanding of the PPE based TPE behavior upon reinforcement with silica nanoparticles and silica sol-gel precursors and the effect of reinforcement on recycling behavior.

Commercially available multiwalled carbon nanotubes (MWNT) were chemically modified by amine, acid and silane and their ethylene vinyl acetate (EVA) based nanocomposites were prepared. Unmodified and modified nanotubes were characterized by thermogravimetry, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and transmission electron microscopy. Early degradation of modified nanotubes from the thermogravimetry study proved the presence of functional groups on nanotube surface. Increase in D-band to G-band ratio and a shift in radial breathing mode peaks from the Raman spectra indicated the generation of surface defects due to functionalization and variation in van der Waals force of attraction between nanotube aggregates on modification. The unmodified nanotubes improved the tensile strength by 30% with 4 weight% of filler. Amine modification imparted further increase in strength due to the presence of functional groups on the nanotube surface and the subsequent better dispersion of the nanotubes in the polymer matrix. The silane treatment imparted maximum improvement in various properties of the nanocomposites. The nanotubes provided better thermal degradation stability and also higher thermal conductivity to virgin EVA. The results were well supported by the morphological as well as swelling study of the various samples.

A comparative study on biodegradation of di-cumyl peroxide (DCP) crosslinked and uncrosslinked natural rubber by Pseudomonas sp. was carried out. Decrease in organic carbon content along with the changes in tensile strength of the treated rubber, both DCP crosslinked and uncrosslinked natural rubber, indicated rubber hydrocarbon utilization by the Pseudomonas sp. A decrease in 60.88% MPa and 41.66% MPa was observed after five month's old treated uncrosslinked natural rubber and DCP crosslinked rubber, respectively. Biodegradation was more pronounced in natural uncrosslinked rubber, which was further confirmed by the formation of aldehydic compounds with decrease in CH2 stretching frequencies.

Esthesioneuroblastoma (Olfactory Neuroblastoma) arises from the olfactory placode in the olfactory area of the nasal cavity. The age incidence ranges from 3 years to 79 years. It usually presents with nasal symptoms like obstructed nasal breathing and epistaxis. The diagnosis may be delayed for several months due to its slow growing nature. It may be misdiagnosed with other small round cell tumors. One such case is reported here due to its rare incidence, difficulty in early diagnosis and very aggressive behaviour compared to the reported series inspite of recommended treatment by different modalities.