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Aims: To compare the antimicrobial efficacy of Bioactive glass, combination of 1% Chlorhexidine gluconate gel and Calcium hydroxide powder and 1% Chlorhexidine gluconate gel as intracanal medicament in primary molars.Settings and Design: In vivo study design Methods and Material: The present study was conducted in the Department of Pediatric and Preventive Dentistry, Krishnadevaraya College of Dental Sciences and Hospital, Bengaluru. This study included 48 subjects within the age group ranging from 4-11 years who were indicated for multi visit Pulpectomy. These subjects were randomly divided into three experimental groups, containing sixteen samples per group. Group 1: Bioactive glass; Group 2:1% Chlorhexidine gel and Calcium hydroxide powder; Group 3:1% Chlorhexidine gel. Under rubber dam isolation, following lesion sterilization S0 sample was obtained. Following access opening and working length, sample S1 was obtained and the respective medicament was placed inside the canals after cleaning and shaping and a double seal was done with ZOE and GIC. Patient was recalled after a period of 5 to 7 days and the medicaments were flushed under isolation and sample S2 was obtained. Pulpectomy procedure was then completed. S0, S1, S2 samples were subjected to microbiological analysis and the total bacterial count in CFU/ml was calculated.Statistical analysis used: Kruskal Wallis Test and One-way ANOVA.Results: The mean percentage of reduction of bacterial count from S1- S2 (Before and after placement of medicament) with Group 1: Bioactive glass was 75.7%, with Group 2:1% Chlorhexidine gluconate and calcium hydroxide was 52% and Group 3:1% Chlorhexidine gluconate was 28.6%, revealing that bioactive glass has the superior antibacterial efficacy when compared with other groups. Antibacterial efficacy of bioactive glass was significant in both primary maxillary and mandibular first molar and second molar proving it to work best for all types of root anatomy in mixed dentition population. Superior clinical and microbiological results were found when bioactive glass was used as intracanal medicament in both intraoral and extra oral abscess cases in primary molars.Conclusions: Bioactive glass; intracanal medicament; primary dentition; primary molar; mixed dentition.

Nanotechnology has gained considerable attention in the present century due to its peculiar properties make it as an effective candidate in multidisciplinary fields with numerous applications. Nanoparticles displays characteristic chemical and physical properties like stability, high thermal and electrical conductivity, optical properties and catalytic activity. These made them promising material for applications in different fields like space applications, industry, photo imaging, photo thermal therapy, cosmetics and medical applications, nano sensors for the detection of biomolecules and several environmental parameters, drug delivery, anti-microbial, anti-pathogens and mosquiticidal uses. The article focuses on the preparing of silver nanoparticles through a greener strategy from a substrate onion peel, which is a domestic waste. The particles synthesized were characterized using UV–Vis Spectroscopy and X-Ray Diffraction. Furthermore, the particles were tested for its antimicrobial activity against two strains of microorganisms. The development of biosensor for environmental contaminants such as heavy metals were also approached. The green pathway we followed are sustainable, environmentally benign, simple, cost-effective and does not produce any harmful byproducts.

Plant mediated synthesis of nanoparticles is a path breaking approach to fabricate ecologically friendly nanoparticles which can be utilized in various applications. The majority of the existing pr...

Metal-insulator-metal (MIM) capacitor with high-k insulator such as BST enhances specific capacitance. The effects of barium mole fraction (x) of BaxSr1 – xTiO3 ceramic-based MIM capacitor on speci...

Silver and carbon nanoparticles are the two inorganic species that have been receiving considerable attention in recent years because of their excellent and fascinating properties. The idea of a combination of these astonishing elements to develop more capable and advantageous nanocomposites with various potential applications arose some time ago. Various procedures have been employed for the synthesis of these nanocomposites. Out of these, green synthesis of silver nanocomposites is examined in this chapter as time asks for that. A more eco-friendly and low-cost method of fabrication of Ag-inorganic nanocomposites is necessary to solve the issues related to toxicity, stability, and environmental concerns. This review evaluates the possible mechanisms for incorporating silver nanoparticles into graphene oxide (GO) sheets and other carbon forms that may generate highly efficient inorganic nanocomposites.

Evidence show that shortened telomere length (TL) and low Vitamin D levels can increase the risk of type 2 diabetes mellitus (T2DM) and its associated complications. T2DM has been considered as an age-related disease, it may be associated with TL. The study aimed to evaluate the association of TL and Vitamin D levels with complications of T2DM and the impact of Vitamin D on TL in patients with T2DM. This 1-year cross-sectional study was conducted at a tertiary care hospital on 90 patients. Height, weight, body mass index, waist-hip ratio was calculated. Fasting blood sugars, postprandial blood sugar, and glycated hemoglobin (HbA1c) were analyzed. Absolute TL was obtained from quantitative real-time polymerase chain reaction (qPCR). Vitamin D estimation was done by chemiluminescent immunoassay. Descriptive analysis of the data was done using R i386 3.6.3. The study found a positive correlation between TL and Vitamin D levels (r = 0.64; P < 0.0001). The interaction with high HbA1c levels and lower levels of Vitamin D led to the shortening of TL (P = 0.0001). The median of TL and mean of Vitamin D levels were significantly less in the diabetic group (P < 0.0001). Vitamin D levels positively affected the TL and its levels had an inverse relation with the HbA1c levels. This association had a significant effect on the shortening of TL. Vitamin D also had a significant association with other diabetic complications that instigated the shortening of TL. Therefore, assessing the role of Vitamin D levels on the shortening of TL can prove to be crucial biomarkers in managing optimal glycemic levels in T2DM patients.

The silver nanoparticles preparation following green pathways have shown great potential with wide applications in different fields include biosensing, biomedical, electronics, catalysis etc. The current study deals with the selective colorimetric detection of mercury using green synthesized AgNPs. Silver nanoparticles were prepared using the extract of Cynodon dactylon, a common medicinal plant from South India following green pathway. The fresh bio- synthesized particles were turned to colorless, together with the extension and blue shifting of Surface Plasmon Resonance band by the addition of mercuric ions into the medium and hence flagged way towards the naked eye detection of mercury and henceforth headed towards the development of cost effective colorimetric sensors. In addition, the antimicrobial potential of the Cynodon based silver nanoparticles were exploited. This work presents a unique method for the synthesis of nanoparticles from a common medicinal plant in Kerala following green approach. Furthermore, the study attempts towards the chemo sensor development for the detection of mercury, a toxic heavy metal in a cost effective manner.

Red oil incidents reported worldwide are attributed to the reactive thermal reactions between Tributyl phosphate (TBP) and nitric acid. The vigor of thermal behavior may be influenced by various factors including irradiation, presence of metal nitrates etc. This work is focused to study the influence of irradiation on the reactive thermal behavior of 30% TBP with varying strengths of HNO3 for the first time. The Accelerating Rate Calorimetry (ARC) studies reveal that irradiated 30% TBP reacts exothermically with 4 mol/L–16 mol/L HNO3 and contributes to rise in system pressure. A lower onset temperature for exothermic reaction was noticed in irradiated TBP compared to the non-irradiated 30% TBP with acid. From the Zero-Order kinetic model, the TMRad for irradiated and non-irradiated TBP 4 mol/L HNO3 system was been determined for thermal hazard assessment. FT-IR, NMR and GC–MS characterization of the residues of ARC clearly suggest that conversion of butanol to butanoic acid is the exothermic red-oil forming reaction.

Tributyl phosphate and its degradation products saturated with nitric acid and exposed to elevated temperatures lead to an accidental condition known as “reactive red oil formation”. The present study aims at elucidating the chemical pathway of this reaction in an Accelerating Rate Calorimeter (ARC). The thermal characteristics obtained from ARC coupled with end product analysis using spectroscopic techniques proved that red-oil forming mechanisms varied as per the concentration of nitric acid. The chemical pathway for red oil formation was found to occur through the oxidation of butanol at lower temperatures and with dilute nitric acid, the predominant path was via butyl nitrite intermediate at higher temperatures. Independent ARC experiments with butanol and butyl nitrite with nitric acid validated the mechanism. This study also revealed that most of the diluents employed for TBP undergo exothermic reaction with nitric acid, even in the absence of TBP.

Cost effective chemosensors were developed from green synthesized silver nanoparticles using Leucas indica and were characterized with surface Plasmon Resonance (SPR) UV Spectrometry. The sensitivity and selectivity of green synthesized silver nanoparticles towards transition metal ions and alkaline earth metals were studied. Applications such as antimicrobial activity and the ability of formed stable nanoparticle to act as chemosensors are also studied. UV studies confirmed the presence of silver nanoparticles by their characteristic peak in range of 436-446nm. Ag NPs also showed antimicrobial activities with gram negative (Escherichia coli) microorganisms.

In the past few years, the science of nanostructure and technology has gained magnificent attention in the worldwide area of research and technology because of its capability to show various applications which are high thermal and electrical properties, magnetic properties, optical properties, catalytic properties, mechanical properties etc. These properties suits them for different technology and uses such as drug design, pharmaceuticals, space applications, cosmetics, medical industries, photo imaging, nano sensors used for the detection and monitoring of biomolecules. It is also suitable in the environmental field of mosquiticidal, antimicrobial properties. This article is basically focused on the synthesis of silver nanoparticles in a greener procedure by using the leaves of Justicia adhatoda (also called as Malabar nut) which is a medicinal plant used for cough, asthma, allergic conditions, excessive uterine bleeding, heavy menstruation etc. and is seen in various parts of India. The silver nanoparticles once synthesized were characterized using UV-Visible spectroscopy and XRD technique. Later, the particles were analysed for antimicrobial activity against two strains of microorganisms. This greener method that we used is simple, economically feasible, environment friendly and does not produce any harmful substances.

Transition metal oxides of FeO-MnO magnetic hetero nanostructures were prepared by chemical co-precipitation method using a biological surfactant Deoxyribonucleic Acid (DNA). The characterization of the nanoparticles was performed by Energy-dispersive X-ray spectroscopy (EDS), X-Ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning Electron Microscope (SEM), and vibrating-sample magnetometer (VSM). Elemental composition was confirmed by EDS.XRD analysis gave information about the crystallinity and two different phases present in the sample. Optical studies were done using FTIR spectroscopy. The sample morphology was explored in SEM images. Magnetic nature confirmed using VSM analysis. Antimicrobial activities of the samples were investigated against bacteria Staphylococcus aureus(S aureus) and Escherichia Coli (E Coli) were swabbed using agarwell diffusion method. The antioxidant properties of the samples were assessed by using DPPH (2, 2-diphenyl-1-picryl-hydrazyl-hydrate) assay, Hydrogen peroxide, hydroxyl, and superoxide free radicals. The synthesized nanoparticles were shown potential activity in scavenging in vitro DPPH assay. The synthesized nanocomposites having reduced size exhibit better scavenging activity and act as good antioxidant compared to others.

Nano Science and technology is an emerging area of research all over the globe because of the peculiar properties make it as a successful candidate in different cross cutting fields with multiple applications. The silver nanoparticles has much importance and widely employed in our day to day life as it exhibits immense potential antimicrobial activity against wide variety of pathogenic microorganisms and henceforth used commonly in medicines, organ implants, theatre products and pharmaceutical products. There are several traditional methodologies for the synthesis of nanoparticles, but all are expensive, time consuming, needs sophisticated equipment’s, chemicals and contaminate the environment. In the current work, we have approached the preparation of nanoparticles following green protocol with the leaf extract from a medicinal plant, Hydnocarpus pentandra. The silver nanoparticles prepared were characterized using UV-Vis Spectroscopy and Scanning Electron Microscopy. The antimicrobial activities where tested for gram negative (Escherichia coli) and gram-positive (Salmonella aureus) microorganisms. The method that we used here is simple, cheap, sustainable and non-poisonous to non-target organisms and does not cause any harm to environment. The larvicidal activity against mosquito larvae were assessed as per World Health Organization Standards. The nanoparticles synthesized exhibits excellent antimicrobial and anti larvicidal activities. We have come up with a novel technique for the synthesis of nanoparticles following green conduit, which is viable, simple, eco-friendly, cost effective, and have explored its applications in different fields.

The development of antibiotics has played a significant role in combating the dreaded infectious disease such as tuberculosis, pneumonia, typhoid fever and meningitis in 20th century. However, the improper use of antibiotics led to the development of multidrug resistance (MDR) in microbial flora raising a global public health concern of 21st century. This unforeseen threat demands the development of new drugs and strategies for combating antibiotic resistance shown by many microbial species. Recent developments in nanotechnology to engineer nanoparticles with desired physicochemical properties have been projected as a new line of defense against MDR micro-organism. In this review, we summarized and discussed the recent development demonstrating the potential of nanomaterials to evade the MDR. Nanoparticles have shown effective antimicrobial activity against MDR bacteria, such as Acinetobacter baumanii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Mycobacterium tuberculosis, vancomycin resistant enterococci, methicillin-resistant Staphylococcus aureus and others. Furthermore, new strategies like combination of radiation and drugs with nanoparticle that are being explored to potentiate the effectiveness against MDR bacteria have also been summarized.

The exothermic behavior of Tributyl Phosphate (TBP) with nitric acid at elevated temperatures is a serious cause of concern in nuclear industry as well as in various other industries where it is the principal extractant. In this study, the comparative study of thermal hazard of TBP and one of its major decomposition products, Dibutyl phosphate, (DBP) has been investigated under adiabatic conditions. Parameters such as comparative self-heat rate and pressure rise were deduced using world’s benchmark adiabatic calorimeter, Accelerating Rate Calorimeter (ARC). FTIR spectrum of the products obtained after ARC experiments pertaining to TBP and DBP are compared.

Background Carcinoma cervix is a leading cause of cancer in Indian females where 15%–60% of the cases eventually metastasize. This is a retrospective review of outcome of metastatic carcinoma cervix patients treated in Kidwai Memorial institute, Bangalore from 2016-2018. Methods We retrospectively analysed our data between October 2016 and September 2018 to identify the cases of metastatic carcinoma cervix and tried to analyse their outcomes with platinum-based chemotherapy. Results 138 cases of metastatic carcinoma cervix were identified during these 2 years. Median age was 49 years (29-73 years). 27(19.5%) patients were HIV+. 39(28.8%) were upfront metastatic & 99(71.8%) were recurrent metastatic. Most common histology was Squamous cell carcinoma, grade II (50%). Nodal recurrence was seen in 108 (78.2%) patients, with most common being pelvic lymph nodes (69.5%) followed by retroperitoneal lymphadenopathy (36.9%) & supraclavicular lymphadenopathy (19.5%). Distant recurrence seen in 93 patients (67.3%) & most common site was lung (54.3%) followed by liver(45.6%), adrenal(4.3%), bone(6.5%) & ascites(8.6%). Nodal-only recurrence was seen in 45 (32.6%) patients. 129(93.4%) patients received palliative chemotherapy as follows- Paclitaxel/Carboplatin (82.6%), Paclitaxel/Cisplatin (6.5%), Gemcitabine/Carboplatin (2.1%), Paclitaxel/Carboplatin/Bevacizumab (2.1%). Overall response rates were 32.6% (CR-4.3%). Median progression-free survival and overall survival (OS) were 6 months and 13 months, respectively. Conclusions Nodal-only metastasis did not show favourable outcome as compared to visceral metastasis. However, disease remains aggressive and poor survival demands further research into newer molecules & regimens. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Background Recurrence is a rule after 1st line therapy in small cell lung cancer (SCLC). Patients who would not tolerate platinum or who recur within 6 months of 1st line therapy; choice of 2nd line is not well defined in them. Methods SCLC patients, who progressed within 6 months after 1st line, or at anytime but who are not candidates for platinum, were non-randomly assigned to receive Paclitaxel 80mg/m2 weekly or Irinotecan 100mg/m2 weekly, till progression or for 12 cycles, or Temozolomide 75mg/m2 21days, every 4 weekly for 6 cycles in patients with brain metastasis. Response, toxicities, survival durations were noted. Results In Irinotecan arm 1(12.5%) had PR, 2(25%) had SD and 3(37.5%) had PD (Response rate[RR]=37.5%). In the Taxane arm, 2(9.5%) had CR, 8(38.0%) had PR, 5(23.8%) had SD, and 6(28.5%) had PD (RR = 71.4%). 2(33.3%) had PR, 1(16.6%) had SD (RR = 50%) in the Temozolomade arm. Mean and median PFS after 2nd line after a min follow up of 18 months was 2.27 and 1.5 months for the whole cohort. Same for Taxane, Irinotecan and Temozolomide were (3.04 and 3 months), (0.81 and 0 months) and (1.5 and 0 months) respectively (p = 0.035). HR for progression for Taxane and Irinotecan were (0.565 p = 0.24, 95% CI [0.218-1.464]) and (1.358 p = 0.575, 95% CI [0.466-3.957]) respectively. Avg grade ¾ haematologic toxicities, febrile neutropenia, GI and hepatotoxicities were lowest for Taxane (0.81/patient p = 0.001, 0.48/patient p = 0.047, 1.14/patient p = 0.137 and 0.19/patient p = 0.08 respectively). Hypersensitivity (all grades) were more common for Irinotecan than taxane (0.62 vs 0.33/patient, p = 0.196). 3 patients died of causes attributed to therapy (2 out of 8 [25%] of Irinotecan arm, 1 out of 21 [4.7%] of Taxane arm). Median OS for the whole cohort was 11.5 months; highest for Taxane 12.5 months> 11 months for Temozolomide>9.5 months for Irinotecan, p = 0.185. HR for death for Taxane and Irinotecan were (0.643 p = 0.376, 95% CI [0.242-1.710]) and (1.383 p = 0.550, 95% CI [0.477-4.009]) respectively. Conclusions Weekly Paclitaxel in 2nd line may have favourable toxicity profile and response rate comparable to Irinotecan or Temozolomide; may translate into better quality of life and OS. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.

Aim To isolate and characterize bacteriocin, BL8, from the bacteria identified as Bacillus licheniformis from marine environment. Methods and Results One-hundred and twelve bacterial isolates from sediment and water samples collected off the coast of Cochin, India, were screened for antibacterial activity. Strain BTHT8, identified as Bacillus licheniformis, inhibited the growth of Gram-positive test organisms. The active component labelled as bacteriocin BL8 was partially purified by ammonium sulphate fractionation and was subjected to glycine SDS-PAGE. The band exhibiting antimicrobial activity was electroeluted and analysed using MALDI-TOF mass spectrometry, and the molecular mass was determined as 1·4 kDa. N-terminal amino acid sequencing of BL8 gave a 13 amino acid sequence stretch. Bacteriocin BL8 was stable even after boiling at 100°C for 30 min and over a wide pH range of 1–12. Conclusion A novel, pH-tolerant and thermostable bacteriocin BL8, active against the tested Gram-positive bacteria, was isolated from Bacillus licheniformis. Significance and Impact of the Study This study reports a stable, low molecular weight bacteriocin from Bacillus licheniformis. This bacteriocin can be used to address two important applications: as a therapeutic agent and as a biopreservative in food processing industry.

The accelerating rate calorimetry studies on the tributyl phosphate and nitric acid reactions at various acid concentrations revealed that the conditions for red oil formation may vary with acid strength. The accelerating rate calorimeter studies supplemented with FT-IR characterization of the end products confirmed the formation of red oil at temperatures as low as 75 °C. This study thus strongly advocates for a revisit of safety limits set in the fuel reprocessing plants to prevent red oil formation. The chemical pathway for red oil formation is worked out.

Violent decomposition of Tributyl Phosphate (TBP), a widely employed extractant in the Plutonium Uranium Extraction process of nuclear fueling reprocessing plants in the presence of Nitric acid at temperatures in excess of 130 °C is a matter of concern in serious accidents including in the Savannah River (USA) and Tomsk (Russia). The thermal behavior of TBP under adiabatic conditions employing the world’s benchmark adiabatic calorimeter, the Accelerating Rate Calorimeter is examined. TBP shows multiple self heating exothermic activities with the onset of primary exotherm at 250 °C. The exothermic activity is accompanied by considerable pressure rise. The thermal decomposition of TBP is found to follow first order Arrhenius kinetic model. TBP loses about 70% of its chemical moieties as volatile matter during the exothermic decomposition. Spectroscopic methods are used to elucidate the degradation pathway.

The tea mosquito bug (TMB) Helopeltis antonii Signoret is a major constraint in cashew cultivation. Exploring host plant resistance will open up new avenues to manage this. The present study is the on biochemical changes occurring in four cashew varieties belonging to highly susceptible and less susceptible categories towards tea mosquito bug. The results reveal that total leaf protein was found to be more in the less susceptible variety Damodar (0.9925 mg g−1) and the least with the highly susceptible Madakkathara-1 (0.6729 mg g−1). Likewise, the total phenol and tannin were more in the less susceptible Damodar (69.834 mg g−1 and 4.276 mg g−1, respectively) and Raghav (67.207 mg g−1 and 4.420 mg g−1, respectively); with the least values being in the highly susceptible Anagha and Madakkathara-1. The activity of polyphenol oxidase was more in Damodar (0.003158 EU g−1min−1) and the least with Anagha (0.001406 EU g−1min−1). These observations on the biochemical changes conclude that there is significant variation in the infestation reactions of TMB in the highly susceptible and less susceptible cashew varieties. Also, the defensive molecules such as tannin, phenols and the defensive enzymes like polyphenol oxidase and phenyl alanine lyase were more in the less susceptible varieties Damodar and Raghav.

A 10-year-old boy admitted for high-grade fever and pneumonia developed left preseptal and early orbital cellulitis, unresponsive to higher intravenous antibiotics. He received oseltamivir, on testing positive for H1N1 virus on the nasopharyngeal and throat swabs. There was dramatic improvement with resolution of orbital cellulitis within 24 h of starting oseltamivir. We report a very rare presentation of pediatric orbital cellulitis secondary to systemic H1N1 infection. Prompt investigations and timely treatment with oseltamivir aided in complete resolution, avoiding vision and life-threatening complications.

Beta-turmerin from turmeric (Curcuma longa) waste grits obtained after extraction of curcumin was purified by successive gel permeation chromatography. Homogeneity of beta-turmerin was confirmed by its movement as single band both in SDS-PAGE and as well as in native (basic) PAGE. The apparent molecular mass is approximately 34 kDa by SDS-PAGE. It is more hydrophobic protein and showed sharp single peak in RP-HPLC with retention time of 62.17 min. It is a glycoprotein as it shows the presence of amino sugars up to 0.021 gm%. In three different model systems i.e., linolenic acid micelles, erythrocyte membrane systems and liposomes, beta-turmerin at 0.125 microM offered 70%, 64%, and 60% inhibition of lipid peroxidation, which is 3200 times more efficient than the standard antioxidants BHA (400 microM) and alpha-tocopherol (400 microM). beta-turmerin inhibited diene-triene and tetraene conjugation up to 54%, 72% and 47%, respectively. beta-turmerin also effectively scavenges hydroxyl radicals when compared to BHA and alpha-tocopherol. beta-turmerin (2.5 microM) further inhibited the activation of PMNL mediated by fMLP up to the extent of 75%, where as standards BHA (400 microM) and mannitol (10 microM) inhibited the same to 65% and 55%, respectively. At 0.125 microM dose beta-turmerin prevented t-BOOH induced cell death at all time intervals. In addition to the above properties, it is non-toxic to lymphocytes as it did not affect the viability of cells. The mechanism of antioxidant action of beta-turmerin could probably be by counteracting/quenching of reactive oxygen species (ROS). We report the purification and characterization of beta-turmerin ( approximately 34 kDa), a potent antioxidant protein from turmeric waste grits.

Highly porous organic inorganic hybrid networks have been prepared from tetraethoxysilane (TEOS) and 3-glycidoxypropyltrimethoxysilane (GPTMS) precursors by drying at ambient pressure. Hydrolysis-condensation reactions of the alkoxy groups on the precursors provide the inorganic network and polymerization of the epoxy group on GPTMS, the organic network. The effects of varying the molar ratios, water/OR, and TEOS/GPTMS (precursor ratio) on the gel structure were investigated. Infrared spectroscopy, thermal analysis, nitrogen adsorption measurements, and tunneling electron microscopy were used to characterize the structure and porosity features of the hybrids. At low precursor ratios, the organic networking is characterized by highly cross-linked polymer chains of low molecular weight and at high precursor ratios it consists of mainly linear chains of high molecular weight. Organic networking reinforces the inorganic network at high precursor ratios and the monoliths effectively withstand the stress produced during drying at ambient pressure. But as the proportion of the organic precursor increases, there is a higher shrinkage of the gel network, increasing the density of the dried gel. Variation in precursor ratio affects the volume of larger pores, while varying water content influences the volume of smaller pores. Monolithic gels with low shrinkage and density could be prepared through ambient pressure drying by this method.

The effect of an organically modified precursor, 3-glycidoxypropyltrimethoxysilane in an ambient pressure process involving aging in silane solution for silica aerogels is presented. The effect of increasing trialkoxysilane/tetraalkoxysilane precursor ratio and the influence of water to Si molar ratio on the gelation and adsorption properties were investigated. An optimum water to Si molar ratio (8) gave the fastest gelation for all precursor ratios indicating a balance between the increase in rate of hydrolysis and a decrease in concentration of the monomers. Surface area analysis proved that in the dried gel, the organic groups are largely present on the pore walls and prevent the condensation of the silanol groups during drying. This in turn prevents pore collapse and further increases the total pore volume. The inclusion of the organically functionalised silane in the process further enhances the ambient pressure drying through this effect.

A new organic–inorganic hybrid synthesized through a sol-gel process starting from alkoxysilane and chitosan is reported. Functionalization of the hybrid was effected through in situ hydrolysis–condensation reaction of methyltrimethoxysilane (MTMS) and vinyltrimethoxysilane (VTMS) in the reaction medium. The process yields highly transparent and hydrophobic silica–chitosan hybrids. The hybrid gel was investigated with respect to chemical modification, thermal degradation, hydrophobicity, and transparency under the ultraviolet-visible region. The extent of hydrophobicity had been tailored by varying the precursor ratio. SiO2–chitosan–MTMS hybrids showed a higher thermal stability than SiO2–chitosan–VTMS (SCV) hybrids with respect to hydrophobicity. Condensation of silsesquioxanes generated from the hydrolysis of MTMS and VTMS over the silica-chitosan particles impart hydrophobicity to the hybrid. The coatings of functionalized SiO2–chitosan precursor sol on glass substrates showed nearly 100% optical transmittance in the visible region. The present hybrid material may find application in optics and other industries.

The effect of hydrocolloids – namely Arabic (AR), guar (GR), xanthan (XN), carrageenan (CG) and hydroxypropylmethylcellulose (HPMC) – on the rheological, microstructural and quality characteristics of south Indian parotta was studied separately at the level of 0.5%. Addition of hydrocolloids increased farinograph water absorption. The extensograph resistance to extension at 135 min increased with the addition of hydrocolloids. Addition of XN, GR and CG decreased extensibility, while AR and HPMC increased extensibility. The alveograph maximum over pressure increased, with the exception of AR, and average abscissa at rupture decreased with different hydrocolloids. The amylograph peak viscosity increased with all the hydrocolloids. In the micrographs of dough treated with different hydrocolloids, the starch granules appeared coated with gum, and the coating appeared prominent in the case of dough treated with GR and HPMC. Among the hydrocolloids tried, GR brought about the greatest improvement in the quality of parotta, followed in decreasing order by HPMC, XN, CG and AR. PRACTICAL APPLICATIONS In India, demand for the large-scale manufacture of packed parottas is increasing. The beneficial effects of hydrocolloids in parotta-making have not yet been explored. This paper discusses the effect of different hydrocolloids on the rheological characteristics of dough in relation to parotta. The information generated on the use of hydrocolloids that are beneficial for parotta-making will be useful for the large-scale manufacturers of parotta.

Silica–gelatin nano-hybrid composites are reported where the synthesis has been done through hydrolysis of tetraethoxysilane (TEOS) in presence of gelatin solution. Chemical interaction between silica and gelatin, gelation characteristics, rheological behaviour of the sol, thermal decomposition of the nanocomposites, porosity features, optical transmittance and thickness of the coatings are reported. FTIR spectra show that the interaction of silica and gelatin is through the hydrogen bonding of C O and N–H groups of gelatin to the silanol hydrogen. However at higher pH, electrostatic interaction between negatively charged silica and gelatin leads to the precipitation of silica. Thermal analysis data show that certain amount of water in the hydrolysed silica precursor is replaced by gelatin molecules and the decomposition of gelatin takes place above 315 °C. We could get a surface area as large as 350 m2 g−1 for silica–gelatin hybrid even without calcination. Coatings of silica–gelatin composite hybrid developed on glass surface has thickness of 300 nm and were found to be >90% transparent as evidenced by optical transmittance measurements. Further the coating can be applied to biological substrates such as leather.

Silica aerogels were synthesised by subcritical drying technique which involves controlled solvent exchange and aging of the wet gel in silane solution followed by drying under controlled conditions. Effect of temperature of aging in silane solution on the porosity characteristics of silica aerogels and the thermal pore stability of the resultant gels were investigated. Aging in silane solution leads to an increased degree of condensation reactions, siloxane crosslinking and the dissolution and reprecipitation of silica monomers to the gel structure and enhances the total strength of the gel. Thermal aging of the wet gel have a pronounced effect on bulk density, linear drying shrinkage, surface area and pore volume. As the temperature of aging increases the bulk density decreases whereas the surface area and pore volume were found to increase. We could achieve a surface area of 1040 m2/g, pore volume 1.2 cc/g and an average pore size of 49 A corresponding to an aging temperature of 70 °C. Thermal pore stability of the gel was found to be up to 700 °C above which densification of SiO2 gel starts. The novel findings will help in tailoring the process parameters to prepare mesoporous oxides from sol–gel precursors with specific pore features.

Curcumin is a fat soluble yellow pigment present in turmeric. The water soluble form of curcumin has been applied onto expanded extruded balls, made from corn and defatted soybean flours. The stability of this natural turmeric colourant has been examined and compared with that of the permitted synthetic colour like tartrazine. The products are packed in polypropylene pouches and subjected to storage studies at ambient (27 °C, 65% relative humidity), and are tested for moisture content, and colour and pigment retention. Brightness of the sample reduces markedly up to 30% during storage. After 10 weeks of storage, the retention of curcumin is about 77%, and the effective shelf life of the product is 6 weeks at ambient condition with 83 and 93% retention of curcumin and tartrazine, respectively. The retention of both colours follows first order kinetics (0.86 ⩽ r ⩽ 0.98, p ⩽ 0.01) while curcumin showing a faster rate of degradation compared to tartrazine. Turmeric colourant may be a viable alternative for tartrazine for using it onto extruded products.

Silica-biopolymer hybrid has been synthesised using colloidal silica as the precursor for silica and gelatin as the biopolymer counterpart. The surface modification of the hybrid material has been done with methyltrimethoxysilane leading to the formation of biocompatible hydrophobic silica-gelatin hybrid. Here we are reporting hydrophobic silica-gelatin hybrid and coating precursor for the first time. The hybrid gel has been evaluated for chemical modification, thermal degradation, hydrophobicity, particle size, transparency under the UV-visible region and morphology. FTIR spectroscopy has been used to verify the presence of CH(3) groups which introduce hydrophobicity to the SiO2-MTMS-gelatin hybrids. The hydrophobic property has also been tailored by varying the concentration of methyltrimethoxysilane. Contact angle by Wilhelmy plate method of transparent hydrophobic silica-gelatin coatings has been found to be as high as approximately 95 degrees . Oxidation of the organic group which induces the hydrophobic character occurs at 530 degrees C which indicates that the surface hydrophobicity is retained up to that temperature. Optical transmittance of SiO2-MTMS-gelatin hybrid coatings on glass substrates has been found to be close to 100% which will enable the hybrid for possible optical applications and also for preparation of transparent biocompatible hydrophobic coatings on biological substrates such as leather.