Methylation of softwood and hardwood kraft lignins with chloromethane.

Methylation is a well-established means of enhancing the thermal stability, improving the compatibility in polymer blends, and lowering the glass-transition temperature of lignins. This process normally involves reagents that are costly, associated with poor atom economy and/or highly toxic. Herein, we report the methylation of softwood and hardwood kraft lignins using chloromethane in alkaline aqueous media. This reaction proceeds in high yields at 90-110 °C under moderate pressure (40 psi) while generating environmentally benign sodium chloride and water as by-products.

Human symptom responses to bioeffluents, short-chain carbonyls/acids, and long-chain carbonyls in a simulated aircraft cabin environment.

Occupants of aircraft have reported an array of symptoms related to general discomfort and irritation. Volatile organic compounds (VOCs) have been suggested to contribute to the reported symptoms. VOCs are from products used, bioeffluents from people and oxidation reaction products. Thirty-six healthy, young female subjects rated symptoms and environmental quality during an eight-hour exposure to groups of compounds often present in aircraft: (i) long-chain carbonyls, (ii) simulated bioeffluents, and (iii) short-chain carbonyls/organic acids. Statistically more symptoms were identified for the simulated bioeffluents and, to a lesser extent, short-chain carbonyls/organic acids compared to a control condition, although they remained in the acceptable range. There were three temporal patterns in the environmental quality and symptom reports: (i) an adaptive response (immediate increases followed by a decline); (ii) an apparent physiological effect (increases one to three hours into the exposure that remained elevated); and (iii) no statistical differences in reported environmental quality or symptom severity compared to the control air conditions. Typical concentrations found in aircraft can cause transitory symptoms in healthy individuals questioning the adequacy of current standards. Understanding the effects on individuals sensitive to air pollutants and methods to remove the compounds causing the greatest symptom responses are needed.

Synthesis and characterization of carboxymethylated xylan and its application as a dispersant.

In this study, carboxymethylated beechwood xylan was produced under alkali conditions using sodium chloroacetate. Taguchi orthogonal design was used to explore the influence of the process parameters, i.e. NaOH concentration, time, temperature, the molar ratio of sodium chloroacetate to xylan and the concentration of the reaction medium on the charge density and degree of substitution (DS) of xylan. Carboxymethylated xylan (CMX) with the maximum charge density of 1.62meq/g and DS of 0.21 was produced under the optimal conditions of 0.75M NaOH concentration, 1.0mol/mol sodium chloroacetate (SCA)/xylan ratio, 2h reaction time, 70°C and 15g/L xylan concentration. The carboxylate group of the product was 1.48mmol/g. The attachment of the carboxymethylated group to xylan was confirmed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ((1)H NMR) spectroscopy. The molecular weight of xylan increased and its thermal stability was improved via carboxymethylation. The dispersion performance of the carboxymethylated xylan in clay suspensions was determined by photometric dispersion analyzer (PDA). CMX showed better performance than sodium carbonate-polyacrylic acid (Na2CO3-PAA) in dispersing the clay suspension. The unmodified xylan did not show any dispersion performance.

Anti-cancer activity of bromelain nanoparticles by oral administration.

Oral administration of anti-cancer drugs is an effective alternative to improve their efficacy and reduce undesired toxicity. Bromelain (BL) is known as an effective anti-cancer phyto-therapeutic agent, however, its activity is reduced upon oral administration. In addressing the issue, BL was encapsulated in Poly(lactic-co-glycolic acid) (PLGA) to formulate nanoparticles (NPs). Further, the NPs were coated with Eudragit L30D polymer to introduce stability against the gastric acidic conditions. The resultant coated NPs were characterized for BL entrapment, proteolytic activity and mean particle size. The stability and release pattern of NPs were evaluated under simulated gastrointestinal tract (GIT) pH conditions. Cytotoxicity studies carried out in human cell lines of diverse origin have shown significant dose advantage (-7-10 folds) with NPs in reducing the IC50 values compared with free BL. The cellular uptake of NPs in MCF-7, HeLa and Caco-2 cells monolayer was significantly enhanced several folds as compared to free BL. Altered expression of marker proteins associated with apoptosis and cell death (P53, P21, Bcl2, Bax) also confirmed the enhanced anti-carcinogenic potential of formulated NPs. Oral administration of NPs reduced the tumor burden of Ehrlich ascites carcinoma (EAC) in Swiss albino mice and also increased their life-span (160.0 ± 5.8%) when compared with free BL (24 ± 3.2%). The generation of reactive oxygen species, induction of apoptosis and impaired mitochondrial membrane potential in EAC cells treated with NPs confirmed the suitability of Eudragit coated BL-NPs as a promising candidate for oral chemotherapy.

First case series of emerging Rickettsial neonatal sepsis identified by polymerase chain reaction-based deoxyribonucleic acid sequencing.

PURPOSE: To detect and identify the aetiological agent in the peripheral blood from the cases of neonatal sepsis. MATERIALS AND METHODS: Four neonates from geographically different regions of South India presented with signs of neonatal sepsis and all the routine clinical and laboratory investigations were performed. Blood culture by Bac T Alert 3D was negative. To establish the aetiology, polymerase chain reaction (PCR) for eubacterial genome and subsequent amplification with Gram positive and Gram negative primers were performed followed by deoxyribonucleic acid (DNA) sequencing. RESULTS: PCR for the detection of eubacterial genome was positive in all the four neonates and further amplification with designed Gram positive and Gram negative primers revealed the presence of Gram negative bacteria. The amplicons were identified as Orientia tsutsugamushi in three neonates and Coxiella burnetti in the other neonate. Multalin analysis was done to further characterise the strain variation among the three strains. CONCLUSION: PCR-based DNA sequencing is a rapid and reliable diagnostic tool to identify the aetiological agents of neonatal sepsis. This is the first case series of emerging Rickettsial neonatal sepsis in India .

Growth in Children with Steroid Sensitive Nephrotic Syndrome.

BACKGROUND: Nephrotic syndrome in children usually has an onset between 2-8 years of age and steroids form the mainstay of management. Therapy may affect growth in children with relapsing nephrotic syndrome. This study was carried out to correlate growth with the cumulative dose of steroids in children with steroid sensitive nephrotic syndrome (SSNS). METHODS: Data of 35 children with SSNS was analysed retrospectively. They were divided into two groups. Group I received prednisolone only and Group II received levamisole and or cyclophosphamide in addition to steroids. Their heights were recorded at the time of inclusion and again one year later. The SD scores for age were determined. Growth rate as a change in the SD score over one year (Δ SD score) was correlated to the cumulative dose of steroids over the same period using the Pearson's correlation. RESULT: There were 24 (68.6 %) boys and 11 (31.4 %) girls (M:F ratio 2.18:1) in the age group of 17 months to 11 years at inclusion. Group I constituted 19 (54.2 %) and Group II, 16 (45.8 %). Pearson's correlation coefficients for all children, Groups I and II were -0.341, -0.441 and -0.255 respectively indicating "Fair correlation". This indicates that as the cumulative dose of steroid increases the growth retardation becomes more apparent. CONCLUSION: Growth retardation is proportional to the cumulative dose of steroids in children with SSNS.

Long-wavelength equation for vertically falling films.

An equation is derived for describing wave evolution on the surface of a vertically falling viscous film. The traditional long-wavelength scaling is replaced by a new scaling to reduce the (We) must be used instead of the Reynolds number (Re) to distinguish between viscous and inertia dominated regimes for vertically falling films. This equation includes viscous dissipation and pressure correction terms that are missing in the existing single evolution equations at the same order. Comparison of the neutral stability curves and growth rates predicted by different models to that of the Orr-Sommerfeld (OS) equation shows that our equation matches with the OS results better than the existing single evolution equations. However, our equation is not free from finite time blowup. Selective regularization leads to a two mode model in flow rate and film thickness. The regularized equation is free from finite time blowup and predicts two families of solitary waves. Numerical simulations of the derived equation and its regularized version in the traveling wave coordinate show the transition of wave structure from regular (periodic) to chaotic profiles. Model predictions on maximum wave amplitude on the low celerity branch show good agreement with experimental data.

Low-dimensional models for vertically falling viscous films.

Long wave evolution on free falling viscous films is described using a new evolution equation. The scaling proposed here brings in the viscous and pressure correction terms that are missing in the existing long-wave equations. Small amplitude expansion of the equation gives a dissipative form of the Kuromoto-Sivashinsky equation. Improved accuracy of the new equation over existing equations is demonstrated by comparison of neutral curves with Orr-Sommerfeld equations and experimental data.

Calibration Point for Electron Ionization MS / MS spectra measured with multiquadrupole mass spectrometers.

A protocol for establishing standard instrument conditions for measurement of product ion MS/MS spectra from parent ions produced by electron ionization is presented. Within this protocol, the ion at m/z 231 (C5F9 (+)) from perfluorokerosene or perfluorotributylamine is selected as the parent ion and subjected to collision-induced dissociation. The relative intensities of product ions at m/z 69, 131, and 181 are monitored as a function of collision energy while keeping the target gas pressure constant within the range of 10(-4)-10(-6) torr (measured), or a beam attenuation of approximately 30-70%. The collision energy at which the ion intensities for product ions at m/z 69 and 181 are equal is defined as the calibration point at that collision gas pressure; the intensity of the ion at m/z 131 is very close to this value as well. Electron ionization MS/MS spectra taken at the calibration point using two different multiquadrupole instruments show good reproducibility for several test compounds. The high degree of similarity may aid in the establishment of a MS/MS spectral library.

The adolescent growth spurt of height among rural Indian boys in relation to childhood nutritional background: an 18 year longitudinal study.

The Adolescent Growth Spurt (AGS) was studied in rural Hyderabad boys of 5+ years of age with known childhood nutritional background. Longitudinal data on height measurements of pre-school children available for 13 to 16 points of follow-up, during an 18 year period of study (i.e., from 1965-66 to 1983-84) were utilized for this purpose. A Preece and Baines model 1 (PB 1) function was fitted for height measurements of 323 boys aged 19-24 years in 1984. The boys were classified into three groups according to degree of under-nutrition at the age of 5+ years, using Boston reference values for height. Boys with severe height deficit at age 5+ were considered to have had a background of severe undernutrition and were referred as Group III. Boys with normal range height measurements at age 5+ were considered to have a normal nutritional background and were referred to as Group I. Group II boys had height deficits in between the above two groups and were considered to have milk to moderate undernutrition backgrounds. Group I boys had similar timing, intensity, duration of Adolescent Growth Spurt Period (AGSP) and gained a similar amount of height during puberty as did British boys. Group III boys differed significantly from British boys for AGS. They entered late into puberty, with significantly depressed intensity, but gained a similar amount of height, as a result of prolonged AGSP, which continued till 19.2 years. Thus a childhood background of undernutrition did not lead to any additional deficit in height during puberty. However, pre-pubertal height deficits were carried into adult height. The growth curves of rural Hyderabad children were parallel to the British distance height curve after 12 years of age. The mean constant height velocity curve of group I boys was superimposable on the British curve during puberty.

New colorimetric method for folic acid assay in dosage forms.

A new colorimetric method has been developed for estimating folic acid. The British Pharmacopoeial method has been modified to reduce folic acid to 2,4,5-triamino-6-hydroxy-pyrimidine (TAHP), which is treated with ninhydrin to yield a stable purple complex. Participation of 5-amino and 6-hydroxy groups of TAHP in the color reaction with ninhydrin is suggested on the basis of experimental evidence. The color obtained has an absorbance maximum at 555 nm and obeys Beer's law in the concentration range of 4.5 to 45 microng folic acid/ml. The method has been successfully used for assaying folic acid, its tablets, and injections.