A multicentric, 2 × 2 factorial, randomised, open-label trial to evaluate the clinical effectiveness of structured physical activity training and cognitive behavioural therapy versus usual care in heart failure patients: a protocol for the PACT-HF trial.

Background: Heart failure (HF) is a multi-morbid chronic condition, which adversely affects the quality of life of the affected individual. Engaging the patient and their caregivers in self-care is known to reduce mortality, rehospitalisation and improve quality of life among HF patients. The PACT-HF trial will answer whether clinical benefits in terms of mortality and hospitalisation outcomes can be demonstrated by using a pragmatic design to explore the specific effects of physical activity, and cognitive behavioural therapy in HF patients in India. Methods: We will conduct a 2 × 2 factorial, randomized, open-label trial, which aims to see if rehabilitation strategies of structured physical activity training and cognitive behavioural therapy for depression and self-management reduce the risk of repeat hospitalisation and deaths in HF patients in India. Patients will be randomised to (1) physical activity + usual care (2) cognitive behaviour therapy + usual care, (3) physical activity + cognitive behaviour therapy + usual care, and (4) usual care at 1:1:1:1 ratio. Time to mortality will be the primary outcome. A composite of mortality and hospitalisation for HF will be the main secondary outcome. Additional secondary outcomes will include 'days alive and out of hospital', cumulative hospitalisation, quality of life, Minnesota Living with Heart Failure questionnaire score, depression score, six minutes walking distance, handgrip strength, and adherence to medicines and lifestyle.  The effects of intervention on the primary outcome will be estimated from Cox proportional hazard models. For the continuous secondary outcome variables, differences between randomised groups will be estimated from linear mixed models or generalised estimating equations (GEE) as appropriate. Discussion: PACT-HF is designed to provide reliable evidence about the balance of benefits and risks conferred by physical activity and cognitive behavioural therapy-based cardiac rehabilitation for those with HF, irrespective of their initial disease severity.

Chitin nanowhiskers from shrimp shell waste as green filler in acrylonitrile-butadiene rubber: Processing and performance properties.

In this work, chitin nanowhiskers with high crystallinity index were obtained from shrimp shells waste using acid hydrolysis method and then comprehensively characterized. Subsequently, the impact of chitin nanowhisker content on processing and performance of acrylonitrile-butadiene rubber based nanocomposites was evaluated. The results showed that the addition of chitin nanowhiskers increased tensile strength and tear strength of nanocomposites by 116 % and 54 %, which was related to suitable dispersion of chitin nanowhiskers in matrix. Reinforcing effect of chitin nanowhiskers in acrylonitrile-butadiene rubber was also confirmed by Wolff activity coefficient, glass transition temperature and equilibrium swelling measurements. Moreover, it was found that higher content chitin nanowhiskers significantly improve the thermal stability of studied nanocomposites. The incorporation of chitin nanowhiskers resulted in increase of 74 °C for onset degradation temperature. This work confirmed that shrimp shell waste can be upcycled into chitin nanowhiskers - promising green filler in NBR for high-performance elastomeric applications.

Cellulose Nanofibers Isolated from the Cuscuta Reflexa Plant as a Green Reinforcement of Natural Rubber.

In the present work, we used the steam explosion method for the isolation of cellulose nanofiber (CNF) from Cuscuta reflexa, a parasitic plant commonly seen in Kerala and we evaluated its reinforcing efficiency in natural rubber (NR). Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Thermogravimetric analysis (TGA) techniques indicated that type I cellulose nanofibers, with diameter: 10-30 nm and a 67% crystallinity index were obtained by the proposed method. The results showed that application of CNF in NR based nanocomposites resulted in significant improvement of their processing and performance properties. It was observed that the tensile strength and tear strength of NR/CNF nanocomposites are found to be a maximum at 2 phr CNF loading, which corresponds with the studies of equilibrium swelling behavior. Dynamic mechanical analysis, thermogravimetric analysis, and morphological studies of tensile fractured samples also confirm that CNF isolated from Cuscuta reflexa plant can be considered as a promising green reinforcement for rubbers.

Green tire technology: Effect of rice husk derived nanocellulose (RHNC) in replacing carbon black (CB) in natural rubber (NR) compounding.

The effect of replacing carbon black (CB) by rice husk derived type-I nanocellulose (RHNC) in natural rubber vulcanization is presented in this study. The synthesized RHNC was characterized using various analytical techniques like FTIR, XRD, SEM, TEM, DLS, TGA etc. The cure characteristics, mechanical, technological, thermal, barrier and dynamic mechanical properties of the composites were analysed. The mechanical properties of the NR composites containing 30 wt% of CB are comparable with the composite containing 25 wt% of CB and 5 wt% of RHNC. The DMA studies show that the loss tangent (tan δ) at 60 °C is lower for the composite containing 5 wt% of RHNC and 25 wt% CB compared to the composite containing 30 wt% CB. This shows that RHNC can impart low rolling resistance, which is a crucial parameter for green tire applications.

A stealth emulsion based on natural rubber latex, core-shell ferrofluid/carbon black in the S and X bands.

A lossy dielectric with an appropriate magnetic property is one of the requirements of a stealth material. The thickness of the absorber and the corresponding bandwidth of absorption are also other deciding factors that determine the choice of the material as microwave absorbers. A stable emulsion, which is lossy as well as magnetic, is promising, since it can be coated on surfaces with required thickness in the desired band. A magnetic nanofluidic emulsion serves the purpose. A microwave absorbing emulsion based on natural rubber latex with core-shell magnetic nanoparticles, based on superparamagnetic iron oxide nanoparticles (SPIONs), was developed. The effect of additives like carbon black on the bandwidth of absorption was also studied as a function of weight percentage of carbon black. The complex dielectric permittivity and magnetic permeability were evaluated using a vector network analyser in the S and X bands. Furthermore, these results were modelled using surface impedance equations. These investigations revealed that the incorporation of carbon black enhances the bandwidth of absorption and an emulsion with the required dielectric permittivity and magnetic permeability can be tailored for stealth applications.

Flexible regenerated cellulose/polypyrrole composite films with enhanced dielectric properties.

Flexible regenerated cellulose/polypyrrole (RC-PPy) conductive composite films were prepared by insitu polymerization of pyrrole on regenerated cellulose (RC) matrix using ammonium persulphate as oxidant. FTIR, XPS and XRD analysis of RC-PPy composite films revealed strong interaction between polypyrrole (PPy) and RC matrix. XRD results indicated that crystalline structure of RC matrix remains intact even after composite formation. SEM micrographs revealed the formation of a continuous conductive network of PPy particles in the RC matrix, leading to significant improvement in electrical and dielectric properties. The electrical conductivity of RC-PPy composites with 12wt% of PPy was 3.2×10-5S/cm, which is approximately seven fold higher than that of RC. Composites showed high dielectric constant and low dielectric loss values, which is essential in capacitor application.

Investigation on the panchromaticity of silver-doped poly(vinyl alcohol)/acrylamide photopolymer.

An investigation on the panchromaticity of a silver-doped poly(vinyl alcohol)/acrylamide photopolymer system is presented in this paper. Frequency-doubled Nd:YAG (532 nm) and Ar⁺ (488 nm) lasers were used for the characterization of the films. Previous studies using an He-Ne laser (632.8 nm) showed that plane-wave transmission grating with a high diffraction efficiency of 75% could be stored in the optimized film. From the present study, it was noted that transmission gratings with 70% diffraction efficiency could be recorded using Ar⁺ and Nd:YAG lasers, thereby elucidating the possibility of using the developed photopolymer system as a competent panchromatic recording medium.

Silver-doped photopolymer media for holographic recording.

Incorporation of silver ions into a dye-sensitized poly(vinyl alcohol)/acrylamide photopolymer is observed to give better performance compared to other metal-ion-doped photopolymer holographic recording media. Plane-wave transmission gratings were recorded in the photopolymer films using a He-Ne laser, and various holographic parameters were optimized so as to explore maximum potential of the material for various holographic applications. Silver-doped films showed good energy sensitivity, and gratings recorded in optimized film exhibited a diffraction efficiency of more than 75%. The potential of the material for holographic data storage applications is also studied using peristrophic multiplexing.

Ground state and excited state dipole moments of alkyl substituted para-nitroaniline derivatives.

The ground state and excited state dipole moment of a series of alkyl substituted para-nitroaniline derivatives is reported. Ground state dipole moment was determined by the Debye-Guggenheim method and the excited state dipole moment was estimated using the solvatochromic method. For all molecules under investigation, the excited state dipole moment was found to be higher than the ground state dipole moment. The molecules exhibited positive solvatochromism.

On the dipole moments and first-order hyperpolarizability of N,N-bis(4-bromobutyl)-4-nitrobenzenamine.

The nonlinear optical molecule N,N-bis(4-bromobutyl)-4-nitrobenzenamine was synthesized. The ground state dipole moment was determined by the Debye-Guggenheim method. A solvent mixture of acetonitrile and toluene was used for the solvatochromic determination of the excited state dipole moment. Excited state has a high value for the dipole moment which indicated a higher degree of charge transfer from the donor to the acceptor moiety on excitation by light. The first hyperpolarizability (beta(ijk)) of the molecule was evaluated assuming the two level model of the first hyperpolarizability.

Enhancement of diffraction efficiency and storage life of poly(vinyl chloride)-based optical recording medium with incorporation of an electron donor.

The diffraction efficiency, sensitivity, and storage life of methylene blue-sensitized poly(vinyl chloride) film was improved by the addition of an electron donor in the matrix. The addition of pyridine enhanced the diffraction efficiency by two times, and storage life of the gratings was increased to 2-3 days.

Fabrication and characterization of methylene-blue-doped polyvinyl alcohol-polyacrylic acid blend for holographic recording.

A methylene-blue-sensitized polymer blend of polyvinyl alcohol and polyacrylic acid is fabricated and tested for holographic recording. It was found to have good characteristics such as high sensitivity, storage stability, ease of fabrication, and environmental stability. Optimization of the ratio of polyvinyl alcohol/polyacrylic acid, the sensitizer concentration, pH, energy, diffraction efficiency measurements, etc., have been done. pH is found to have a great influence on the recovery of the dye in this matrix. The results of experimental investigations into the properties of this new material are reported.

Complex methylene-blue-sensitized polyvinyl chloride: a polymer matrix for hologram recording.

A new polymer matrix sensitized with methylene blue for use as an optical recording material is described here. The characterization is done to determine the optimal recording conditions. These films need no chemical development and are found to be stable for several months. The matrix has excellent shelf life and needs an exposure only as short as 20 s. Direct imaging was done on this material.