Biocompatible electrospun tactic poly(methyl methacrylate) blend fibers

Uniform and beads free fibers of pristine syndiotactic PMMA (s-PMMA), isotactic PMMA (i-PMMA), and their blends in the ratio of s:i = 3:1, 1:1 and 1:3 were successfully prepared using the electrospinning technique. The tactic PMMA blend fibers showed unique thermal stability and glass transition temperatures compared to their pristine counterparts. An interesting endotherm peak was observed for the s:i = 1:3 electrospun fibers, which might indicate a complex formation between the two tactic PMMAs. Systematic surface functionalities study by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) revealed the interactions between these two tactic PMMAs. Biocompatibility of tactic PMMA and their blend fibers was first time comparably investigated using HeLa as the model mammalian cell line; an intriguing observance was first revealed that the blend fibers showed better biocompatibility than both pristine ones, though the behind mechanism is not well understood yet.     

Structural changes of starch/polyvinyl alcohol biocomposite films reinforced with microcrystalline cellulose due to biodegradation in simulated aerobic compost environment

Starch/Polyvinyl alcohol (PVA) based biocomposite films reinforced with micro crystalline cellulose (MCC) (10 wt %) particles were prepared by solution casting method, incorporating glycerol as plasticizer. These biocomposite films were subjected to biodegradation at ambient temperature in a simulated aerobic compost pit. The extent of biodegradation of these films was studied in terms of weight loss. The corresponding changes in the structure of the films were observed using scanning electron microscopy, X‐Ray diffraction study, and differential scanning calorimetry. The melting point of PVA component of the biocomposite film shifted from 204 to 223°C with increase in biodegradation time and a remarkable difference was observed in their melt crystallization behavior. The unreinforced films also showed a similar trend, but the increase in the crystallinity of PVA was more pronounced in MCC reinforced films than that observed in the unreinforced ones. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.     

METHANOL TO GASOLINE: IMPROVED GASOLINE YIELDS

The role played by the catalyst in the mehhanol-to-gasoline process under varying conditions is significant. The mobil ZSM-5 catalyst yielded dimethyl ether as a major product in earlier experiments conducted in the Chemical Engineering Department. This prompted us to ascertain those parameters which yielded a high percentage of gasoline and minimized or eliminated dimethyl ether. A number of parameters like residence time, reaction temperature, and methanol catalyst weight ratio were studied and knowledge regarding how best a high gasoline yield could be produced was obtained. Product characterization was done by gas chromatographic analysis. GC-MS proved to be an extremely beneficial tool.     

LoWaNA: low overhead watermark based node authentication in WSN

Nodes in a wireless sensor network (WSN) are generally deployed in unattended environments making them susceptible to attacks. Therefore, the need of defending such attacks is of utmost importance. The challenge in providing security in this network is that the securing mechanism must be lightweight to make it implementable for such resource-constrained nodes. A robust security solution for such networks must facilitate authentication of sensor nodes. So far, only data authentication has drawn much attention from the research community. In this paper, a digital watermark based low-overhead solution (LoWaNA) is proposed for node authentication. The proposed watermarking technique consists of three modules viz. watermark generation, embedding and detection. The robustness of the algorithm is measured in terms of cracking probability and cracking time. This robustness analysis helps us to set the design guideline regarding size of watermark. Performance of the scheme is analyzed in terms of storage, computation and communication overhead. The analytical results are compared with two of the existing schemes and that show significant reduction of all such overheads. Thus it proves the suitability of the proposed scheme for resource-constrained networks like WSN. Finally the entire scheme is simulated in Cooja, the Contiki network simulator to make it readily implementable in real life mote e.g. MICAz.

     

Microhardness study of the nonlinear optical crystal L-arginine hydrochloride monohydrate

The results of measurement of the Vickers microhardness (H _v ) of the (100), (010), and (001) faces of the nonlinear optical (NLO) crystal L-arginine hydrochloride monohydrate (LAHCl) have been reported. It was observed that the microhardnesses of the three crystal planes decrease with the increase of applied load, and the hardness profile is different for different planes. The proportional specimen-resistance (PSR) model of Li and Bradt is used to explain the microhardness behavior of LAHCl. The indentation work-hardening coefficients (n) for three planes were found to be greater than 1.8, and this indicates that LAHCl is a soft crystal.     

Surface treatment of cellulose fibers with methylmethacrylate for enhanced properties of in situ polymerized PMMA/cellulose composites

Cellulose micro/nanofibers (CNF), prepared from jute fibers were surface treated with methyl methacrylate (MMA) for better dispersion into poly methyl methacrylate (PMMA) matrix. PMMA/cellulose composites were prepared by in situ suspension polymerization technique. The surface treatment of CNF was confirmed by Fourier transform infrared spectroscopy (FTIR) and Nuclear magnetic resonance (NMR) analysis. MMA‐treated cellulose micro/nanofibers (MCNF) demonstrated improved affinity and dispersion in MMA monomer as well as in the PMMA/cellulose composites. Thermal properties of the cellulose composites were analyzed by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The glass transition temperature (T_g) of PMMA increased by nearly 19°C in the in situ cellulose composites compared to that of unreinforced PMMA as indicated by DSC. TGA showed increased thermal stability of the cellulose composites. Enhanced tensile properties as well as significantly lower moisture uptake were observed in the in situ prepared PMMA/cellulose composites. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39808.     

METHANOL TO GASOLINE: IMPROVED GASOLINE YIELDS

ABSTRACT

The role played by the catalyst in the mehhanol-to-gasoline process under varying conditions is significant. The mobil ZSM-5 catalyst yielded dimethyl ether as a major product in earlier experiments conducted in the Chemical Engineering Department. This prompted us to ascertain those parameters which yielded a high percentage of gasoline and minimized or eliminated dimethyl ether. A number of parameters like residence time, reaction temperature, and methanol catalyst weight ratio were studied and knowledge regarding how best a high gasoline yield could be produced was obtained. Product characterization was done by gas chromatographic analysis. GC-MS proved to be an extremely beneficial tool.     

Design and development of cancer regulatory system by modeling electrical network of gene

An electrical network system for prostate gene is realized using individual amino acid model to reduce the computational load of existing gene system. A control strategy is also incorporated along with the reduced gene system to control the progression of cancer gene. The amino acids Tyrosine, Phenylalanine, Glutamine and Methionine are treated as inhibitor and Tryptophan as booster element in the cancer regulatory system, which control the growth of cancer. The system performance is analyzed by measuring percentage of error with frequency. The accuracy of the model is tested on 35 gene samples associated with prostate cells and achieved 96.7 % accuracy. The main focus of the paper is to identify the cancerous and healthy prostate genes, and regulate the specific amino acid for inhibiting the growth and metastasis of prostate cancer. The electrical response of the model is truly matched with biological characteristics beyond the frequency of 50 kHz.     

Interaction of a Triantennary Quinoline Glycoconjugate with the Asialoglycoprotein Receptor

Targeted intracellular delivery is an efficient strategy for developing therapeutics against cancer and other intracellular infections. Nonspecific drug delivery shows limited clinical applications owing to high dosage, cytotoxicity, nonspecific action, high cost, etc. Therefore, targeted delivery of less cytotoxic drug candidates to hepatocytes through ASGPR-mediated endocytosis could be an efficient strategy to surmount the prevailing shortcomings. In the present work, the gene encoding ASGPR-H1-CRD was amplified from Huh7 cells, cloned into pET 11a vector, and the ASGPR-H1-CRD protein was expressed and purified from E. coli. A novel triantennary galactose-conjugated quinoline derivative 4 was synthesized that demonstrates 17-fold higher binding affinity to isolated ASGPR-H1-CRD protein receptor (K_d∼54 μM) in comparison to D-galactose (K_d∼900 μM). Moreover, micro-calorimetric studies for the interaction of glycoconjugate 4 with ASGPR protein on live hepatocytes showed notable thermal response in case of ASGPR-containing Huh7 cells, in comparison to non-ASGPR Chang cells. These results might serve as an approach towards targeted delivery of small glycoconjugates to hepatocytes.     

Lauric acid coated fly ash as a reinforcement in recycled polymer matrix composites

Sustainable composites were developed from fly ash (FA) and recycled polypropylene (R) with lauric acid (LA) as the coupling agent. The FA particles were surface‐coated with 1, 2, 3, and 5 wt % LA, and the coating on the FA particles was verified by transmission electron microscopy and Fourier transform infrared spectroscopy. R and LA‐coated FA particles were melt‐mixed in a 1:1 weight ratio to achieve a high‐filler‐loaded composite. The flexural, impact, nanoindentation, and fracture surface analyses were carried out to examine the properties of the composites. The flexural strength and modulus values increased in the 2 wt % LA‐coated FA/R composites by 6 and 50%, respectively, compared to the values of the uncoated FA/R composites, whereas the impact strength increased considerably by 119% in the 1 wt % LA‐coated composites. Nanoindentation tests also showed an increase in the mechanical properties in the case of the 1 and 2 wt % LA‐coated composites in comparison to the uncoated ones. Fracture surface studies done by scanning electron microscopy revealed improved interfacial interactions between the filler and matrix in the presence of the LA coupling agent. X‐ray diffraction (XRD) studies indicated reorientations of the polymer chains in the presence of different concentrations of the LA coupling agent; this resulted into different crystallinities and crystallite sizes. Differential scanning calorimetry showed a significant difference in the crystalline peaks of the composites, and this corroborated well with the XRD observations. LA, thus, significantly influenced the structural properties of the composites, and this, in turn, influenced their mechanical and thermal properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41586.