Synthesis of guar gum maleate under dry conditions: Reaction kinetics and characterization.

In the present study, a novel environment friendly dry method for preparation of guar gum maleate (GGM) with varying degrees of substitution (DS; 0.02-1.04) was optimized. GGM with a maximum DS of 1.04 was successfully synthesized using guar gum (GG) and maleic anhydride (MA) in proportion of 1: 1 at 80 °C with 4 h of reaction time. The activation energy for the reaction was determined to be 36.91 ± 3.61 kJ mol-1 with pre-exponential factor of 1392 min-1. Esterification of GG was confirmed by FT-IR and 13C NMR. Analysis using size exclusion chromatography (SEC) indicated a decrease in weight average molecular weight (Mw) of the polymer with an increase in polydispersity index (PDI) due to esterification. In comparison with GG, GGM displayed increased hydrophobicity and reduced thermal stability, as analysed by differential scanning calorimetry (DSC). Rheological studies of GGM revealed that initial apparent viscosity decreased with increasing DS. For the first time, the study offered valuable insights on GGM synthesis under dry solvent-less reaction conditions enabling simpler and scalable synthesis process.

Efficacy of middle-ear packing in success of type 1 tympanoplasty: a prospective randomised study.

OBJECTIVE: A prospective randomised study was undertaken to compare the results of type 1 tympanoplasty with and without middle-ear packing with gelfoam. METHOD: Eighty patients undergoing type 1 tympanoplasty were randomised into two groups according to packing in the middle ear: with gelfoam and without gelfoam. The data in terms of graft uptake rate, hearing gain and subjective improvement were analysed at one and three months. RESULTS: The graft uptake rate between both groups did not show a statistically significant difference. There was conductive hearing loss in the gelfoam group in the early post-operative period. Subjectively, patients were more comfortable with respect to heaviness and hearing gain than in the non-gelfoam group. CONCLUSION: Gelfoam use in middle-ear packing is not an essential step and causes more discomfort in patients during the early post-operative period. It should be a surgeon's choice to use it when and where it is necessary.

Melt layer erosion during ELM-like heat loading on molybdenum as an alternative plasma-facing material.

Transient events that occur during plasma instabilities in fusion reactors impart large heat fluxes onto the surrounding plasma-facing components (PFCs). Erosion and splashing of PFCs can contaminate the plasma and shorten material lifetime. Although tungsten is currently considered the most promising candidate material for future PFCs, concerns over the thermal shock performance during type-I ELMs (transient events expected in fusion devices) necessitate the study of other comparable materials. ELM-like heat loading was applied via a pulsed Nd:YAG millisecond laser on a pristine molybdenum (Mo) surface to measure surface melting and mass loss. One potential advantage of Mo is its higher specific heat of vaporization, which could lead to reduced particle emission. Imaging of the surface after loading revealed that complete surface melting began at 1.0 MJ m-2 (heat load parameter of 31.62 MJ m-2 s-1/2). Photon excitation also increased significantly above 1.0 MJ m-2, indicating possible phase change. At 1.4 MJ m-2 (44.27 MJ m-2 s-1/2), in situ mass loss measurements found an exponential increase in particle emission, indicating the presence of droplet formation and boiling. Direct comparisons of erosion during pulsed heat loading between PFC candidate materials will ensure that future fusion devices design components with optimal thermal strength.

Antimicrobial assay and genetic screening of selected freshwater Cyanobacteria and identification of a biomolecule dihydro-2H-pyran-2-one derivative.

AIMS: Explorations of freshwater Cyanobacteria as antimicrobial (bacteria, fungi and methicillin-resistant Staphylococcus aureus (MRSA) strains) drug resource using bioassay, NRPS (non-ribosomal polypeptide synthetase) and PKS (polyketide synthase) genes, as well as in silico approach. METHODS AND RESULTS: We have bioassayed the extracts of Phormidium CCC727, Geitlerinema CCC728, Arthrospira CCC729, Leptolyngbya CCC732, Phormidium CCC730, Phormidium CCC731 against six pathogenic bacteria comprising Gram (+ve): S. aureus including seven clinical MRSA and Enterococcus faecalis, Gram (-ve): Escherichia coli, Salmonella Typhimurium, Klebsiella pneumoniae and Shigella boydii along with non-pathogenic Enterobacter aerogenes as well as fungal strains (Cryptococcus neoformans and Candida albicans, C. krusei, C. tropicalis and Aspergillus niger) exhibiting antimicrobial potential. The NRPS and PKS genes of the target strains were also amplified and sequenced. The putative protein structures were predicted using bioinformatics approach. CONCLUSION: PKS gene expression indicated ß keto-acyl synthase as one of the important active domains in the biomolecules related to antitumour and antifungal group. The simultaneous identification of the biomolecule (dihydro-2H-pyran-2-one derivative) was also inferred spectroscopically. SIGNIFICANCE AND IMPACT OF THE STUDY: Freshwater Cyanobacteria are prolific producers of secondary metabolite(s) that may act as the antimicrobial drug resource in addition to their much explored marine counterpart.

Effect of high-flux, low-energy He+ ion irradiation on Ta as a plasma-facing material.

The goal of this work is to assess Ta as a potential plasma-facing material for future fusion reactors in terms of its response to high-flux, low-energy He+ ion irradiation. Ta samples were irradiated with 100 eV He+ ions at various fluences up to 3.5 × 1025 ions m-2 while simultaneously heated at constant temperatures in the range 823-1223 K. SEM studies show that irradiated Ta surfaces undergo significant morphology changes that have a strong dependence on both ion fluence and sample temperature. Optical reflectivity complements SEM and demonstrates a vertical growth of surface structures with increasing fluence. Ex situ XPS and XRD both show significant oxidation of the irradiated Ta surfaces, giving further qualitative information on the extent of surface modification. Overall, these irradiation-induced structures on Ta are similar to early-stage "fuzz" structures observed in W. However, Ta exhibits a higher fluence threshold for structure formation. While Ta may have less desirable bulk properties (e.g., thermal conductivity) when compared to W, its higher resilience to He+ ion-induced surface modification suggests that surface thermal and mechanical properties may not degrade as quickly in extreme fusion environments; this quality may be a redeeming factor for Ta as a plasma-facing material.

An appraisal of the bioavailability enhancers in Ayurveda in the light of recent pharmacological advances.

The concept of bioavailability enhancer is new to the modern system of medicine. Basically, this concept originated in Ayurveda and being used in this system of medicine since centuries. Bio-enhancers augment the bioavailability or biological activity of drugs when co-administered with principal drug at low doses. Ayurveda is using several drugs such as Piper longum Linn., Zingiber officinale Rosc., and Glycyrhhiza glabra Linn. as bio-enhancers and different methods for bio-enhancing since centuries. The bio-enhancement leads to reduction in therapeutic dose of principal drug, thus reducing the possibilities of toxicity and side effects of drug, potentiating the efficacy, reducing the resistance, decreasing the requirement of raw material for drug manufacture, and ultimately benefitting to the world economy by reducing the treatment cost. This review article attempts to consolidate different drugs as well as methods being used traditionally for enhancing bioavailability in Ayurvedic system of medicine and to discuss their possible mechanism of action. Authentic subject material has been reviewed from different Ayurvedic texts and from different related research and review articles. Thus, it is a humble effort to explore the different aspects of bio-enhancers including therapeutic techniques such as Shodhana, the drugs such as Pippali, and properties such as Yogavahi and Rasayana, which have been described in Ayurveda along with their mechanism of action and uses wherever available.

Identification and structure elucidation of antimicrobial compounds from Lyngbya aestuarii and Aphanothece bullosa.

Cyanobacteria are known to produce array of compounds. In an earlier report, we reported antibacterial and antifungal activities in methanolic crude extracts of laboratory grown Lyngbya aestuarii and Aphanothece bullosa isolated from Chilka Lake and local paddy field respectively. In this report the same methanolic crude extracts were subjected to TLC purification twice by altering the solvents and UV—illuminated bands bioassayed. Such UV illuminated potent bands obtained after 2nd TLC were subjected to spectroscopic analysis (UV, IR, 1H NMR and LCMS/MS). We have screened malyngolide and dragonamide C from L. aestuarii and a diterpenoid and majusculoic acid from A. bullosa. Dragonamide C and malyngolide were found to be antifungal while majusculoic acid and a diterpenoid as antibacterial. As far as our knowledge goes, this is the first ever report where fresh water A. bullosa was found to be a source of diterpenoid and majusculoic acid. Likewise, L. aestuarii was also established as a source of malyngolide and dragonamide C. This again indicated that cyanobacteria are inherently endowed with the capacity to produce metabolites according to niche and species specific manner emphasising fresh water cyanobacterial strain are as important as marine one.

Structural and photoluminescence study of Mn2+-activated CaYAl3 O7 blue phosphors.

The structural and photoluminescence properties of CaYAl3 O7 phosphor material doped with varying concentration of Mn(2+) have been studied. The phosphor material was synthesized by the combustion method at 500 °C and was characterized using X-ray diffraction, Fourier transform infrared spectroscopy and photoluminescence spectroscopy (PL). X-ray diffraction showed that the crystallites have average sizes in the range of ~58-70 nm. Corresponding Fourier transform infrared spectroscopy investigations confirm the phase formation and the presence of aluminate group (Al-O bands) in CaYAl3 O7 :Mn(2+) phosphor. Under the excitation at 356 nm wavelength, the PL spectra show the occurrence of two emission peaks obtained in the blue region at 389 nm and 412 nm, which is attributed to the 4 T1(G) → 6A1 transition of Mn(2+) ion. Upon increasing Mn(2+) concentration, the relative PL intensity shows an initial decrement followed by an increase displaying the effect of concentration quenching. Overall the results suggest the possibility of using this material in white lighting devices and plasma display panels.

The effect of Fe-coverage on the structure, morphology and magnetic properties of α-FeSi2 nanoislands.

Self-assembled α-FeSi(2) nanoislands were formed using solid-phase epitaxy of low (~1.2 ML) and high (~21 ML) Fe coverages onto vicinal Si(111) surfaces followed by thermal annealing. At a resulting low Fe-covered Si(111) surface, we observed in situ, by real-time scanning tunneling microscopy and surface electron diffraction, the entire sequence of Fe-silicide formation and transformation from the initially two-dimensional (2 × 2)-reconstructed layer at 300 °C into (2 × 2)-reconstructed nanoislands decorating the vicinal step-bunch edges in a self-ordered fashion at higher temperatures. In contrast, the silicide nanoislands at a high Fe-covered surface were noticeably larger, more three-dimensional, and randomly distributed all over the surface. Ex situ x-ray photoelectron spectroscopy and high-resolution transmission electron microscopy indicated the formation of an α-FeSi(2) island phase, in an α-FeSi(2){112} // Si{111} orientation. Superconducting quantum interference device magnetometry showed considerable superparamagnetism, with ~1.9 µ(B)/Fe atom at 4 K for the low Fe-coverage, indicating stronger ferromagnetic coupling of individual magnetic moments, as compared to high Fe-coverage, where the calculated moments were only ~0.8 µ(B)/Fe atom. Such anomalous magnetic behavior, particularly for the low Fe-coverage case, is radically different from the non-magnetic bulk α-FeSi(2) phase, and may open new pathways to high-density magnetic memory storage devices.

Transgenic banana expressing Pflp gene confers enhanced resistance to Xanthomonas wilt disease.

Banana Xanthomonas wilt (BXW), caused by Xanthomonas campestris pv. musacearum, is one of the most important diseases of banana (Musa sp.) and currently considered as the biggest threat to banana production in Great Lakes region of East and Central Africa. The pathogen is highly contagious and its spread has endangered the livelihood of millions of farmers who rely on banana for food and income. The development of disease resistant banana cultivars remains a high priority since farmers are reluctant to employ labor-intensive disease control measures and there is no host plant resistance among banana cultivars. In this study, we demonstrate that BXW can be efficiently controlled using transgenic technology. Transgenic bananas expressing the plant ferredoxin-like protein (Pflp) gene under the regulation of the constitutive CaMV35S promoter were generated using embryogenic cell suspensions of banana. These transgenic lines were characterized by molecular analysis. After challenge with X. campestris pv. musacearum transgenic lines showed high resistance. About 67% of transgenic lines evaluated were completely resistant to BXW. These transgenic lines did not show any disease symptoms after artificial inoculation of in vitro plants under laboratory conditions as well as potted plants in the screen-house, whereas non-transgenic control plants showed severe symptoms resulting in complete wilting. This study confirms that expression of the Pflp gene in banana results in enhanced resistance to BXW. This transgenic technology can provide a timely solution to the BXW pandemic.

Anti-histaminic, mast cell stabilizing and bronchodilator effect of hydroalcoholic extract of polyherbal compound- Bharangyadi.

Bronchial asthma is a chronic inflammatory disorder of the airways associated with reversible airway obstruction and increased airway responsiveness to a variety of stimuli. An intuitive inference from this definition is that a causal relationship may exist between airway inflammation and airway hyperresponsiveness. It can be say that "airway inflammation equal to airway hyperresponsiveness". Attachment of antigen antibody complex to the mast cell causes its disruption and release of inflammatory mediators such as histamine.To evaluate the efficacy of anti-asthmatic property of a drug, evaluation of anti-histaminic, mast cell stabilizing and bronchodilator property can be use as pharmacodynamic parameter. Bharangyadi is a polyherbal compound having Bharangi (Clerodendrum serratum), Sati (Hedychium spicatum) and Pushkarmoola (Inula racemosa) as ingredient herbs The present study aimed to evaluate the anti-asthmatic activity of an indigenous polyherbal compound Bharangyadi through various in-vitro & in-vivo experimental models.The results demonstrate that drug has potent histamine antagonism property with significant mast cell stabilizing and spasmolytic activity in the experimental animals. Compound 48/80, a potent mast cell degranulator, provoked 76% degranulation of mast cells in the control group. Ethanolic extract of Bharangyadi at the doses 500 and 1000 µg/ml protected from compound 48/80-evoked degranulation (P < 0.01) in dose dependent manner.Pre-treatment with Bharangyadi extract showed 80% & 86% protection from histamine induced bronchoconstriction in guinea pigs with 27.8% and 36.1% increase in preconvoulsion time (equal to standard drug). Screening of Histamine antagonism activity on guinea pig ileum showed that drug reduces the smooth muscle contraction in dose dependent manner. Increasing concentration of Bharangyadi extract with maximum dose of histamine (1.6µg) showed maximum inhibition at the dose of 50mg (99.78%). Inhibition of smooth muscle contraction by addition of drug in organ bath before adding histamine showed that drug has preventive type antagonism.

Evaluation of antimicrobial activity and bronchodialator effect of a polyherbal drug-Shrishadi.

OBJECTIVE: To investigate antimicrobial and bronchodialator effect of hydroalcholic extract of polyherbal drug Shirishadi containing Shirisha (Albezzia lebbeck), Nagarmotha (Cyprus rotandus) & Kantakari (Solanum xanthocarpum). METHODS: Antimicrobial activity was evaluated by disc diffusion method and MIC, MBC, MFC were calculated by micro dilution method. Hydroalcholic extract of this preparation was investigated for its phytochemical analysis, phenol and flavonoid were determined by spectrophotometric method and in vivo bronchodilator effect was analysed by convulsion time. RESULTS: The phytochemical tests revealed presence of alkaloids, anthraquinones, carbohydrates, flavonoids, saponins and tannins. The antimicrobial result showed the MIC of 6.25 mg/mL against Staphylococcus aureus and 12.5 mg/mL for Escherichia coli and 12.5 mg/mL against remaining bacteria tested, with strong antifungal activity. The maximum inhibition zone is found against Pseudomonas aeruginosa with MIC 16 mg/mL. Drug showed significant bronchodilator effect with 27.86% & 36.13% increase in preconvulsion time of guinea pigs pretreated with 100 & 200 mg/kg body weight of extract. CONCLUSIONS: The study reveals that the extracts possess antibacterial activity and antifungal activity in a dose dependent manner. This antimicrobial property may be due to presence of several saponins, further studies are highly needed for the drug development.

A Comparative clinical trial on the role of Panchakarma therapy and Unmada Gajankusha Rasa in the cases of major depressive disorder vis-à-vis kaphaja Unmada.

Depression is a common but serious mood disorder which exerts wide range of physical, physiological and psychological impact. On the basis of the severity of disease, depression is classified under various categories. Of all the types of depression, major depressive disorder resembles the features of kaphaja Unmada. The patients of Kaphaja Unmada are dirty in appearance, their speech and activities are retarded and they prefer to remain in solitude and lonely places. The presentstudy has been conducted in eighty patients of major depressive disorder dividing them into four groups, A, B, C and D using Vamana therapy and Unmada Gajankusha Rasa in the dose of 250 mg twice daily with water. The results were assessed on scoring of clinical symptoms and signs and by using Hamilton depression rating scale (HDRS).The results reveal the mild to moderate degree of response over various parameters which has been presented in detail in the article.

Clinical efficacy of Rasona Pinda in the management of Amavata (rheumatoid arthritis).

In the present clinical study, 63 patients of Amavata were registered from the Kayachikitsa out patient department/indoor patient department (OPD/IPD) of Sir Sunder Lal Hospital (Indian Medicine Wing), IMS, BHU, Varanasi-5. In group I (Rasona Pinda), 27 patients completed the study of a total of 33patients registered in the group (six patients dropped out mid-therapy). In group II (control group), 23 patients completed all three follow-ups out of 30 patients (there were seven dropouts in mid-therapy). In group I, complete remission in 29.6%, major improvement in 59.3% and minor improvement in change font so as to appear 11.1% were observed. In group II, complete remission in 13%, major improvement in 21.7%, minor improvement in 39.1% and unchanged in 26.9% of the patients were observed.

Human babesiosis--a case report.

Babesiosis is an emerging, tick-transmitted, zoonotic disease caused by hematotropic parasites of the genus Babesia. Most cases of Babesial infections in humans have been acquired in temperate regions of the United States, Europe, France and England. A few cases of Babesiosis have been described in other parts of the world, including China, Taiwan, Egypt, South Africa, and Mexico.1,2 We report the first case of human Babesiosis, in a normosplenic, previously healthy individual from India.

Leading Article - Role of biotechnology in medicinal plants

Medicinal plants are the most important source of life saving drugs for the majority of the world's population. The biotechnological tools are important to select; multiply and conserve the critical genotypes of medicinal plants. In-vitro regeneration holds tremendous potential for the production of high-quality plant-based medicine. Cryopreservation is long-term conservation method in liquid nitrogen and provides an opportunity for conservation of endangered medicinal plants. In-vitro production of secondary metabolites in plant cell suspension cultures has been reported from various medicinal plants. Bioreactors are the key step towards commercial production of secondary metabolites by plant biotechnology. Genetic transformation may be a powerful tool for enhancing the productivity of novel secondary metabolites; especially by Agrobacterium rhizogenes induced hairy roots. This article discusses the applications of biotechnology for regeneration and genetic transformation for enhancement of secondary metabolite production in-vitro from medicinal plants

Inflammatory cytokines and oxidized low density lipoproteins increase endothelial cell expression of membrane type 1-matrix metalloproteinase.

We investigated whether inflammatory cytokines or oxidized low density lipoproteins (Ox-LDL) present in human atheroma modulate extracellular matrix degradation by inducing membrane type 1-matrix metalloproteinase (MT1-MMP) expression. Cultured human endothelial cells (EC) constitutively expressed MT1-MMP mRNA and protein with enzymatic activity. Tumor necrosis factor-alpha (TNF-alpha), interleukin-1alpha, or interleukin-1beta caused a time-dependent increase in the steady-state MT1-MMP mRNA levels within 4 h of exposure, peaking about 4-fold by 6 h, and remaining elevated for 12 h. Increased MT1-MMP mRNA correlated with a 2.5-fold increase in MT1-MMP protein in EC membranes. Ox-LDL also increased MT1-MMP mRNA levels that varied with the duration of exposure and degree of LDL oxidation. The increase in MT1-MMP mRNA occurred within 6 h of exposure to Ox-LDL and peaked over 3-fold by 6 h. Ox-LDL, but not native LDL, increased MT1-MMP protein by 2-fold in EC membranes. A combination of TNF-alpha and Ox-LDL was additive in increasing MT1-MMP expression. Nuclear run-on assays showed that TNF-alpha or Ox-LDL augmented steady-state mRNA levels by increased transcription of the MT1-MMP gene. These findings indicate that activation of EC by inflammatory cytokines and/or Ox-LDL increase MT1-MMP expression. Since MT1-MMP promotes matrix degradation by activating pro-MMP-2, these results suggest a novel mechanism whereby cytokines or Ox-LDL may influence extracellular matrix remodeling.

Hemoglobin endocytosis in Leishmania is mediated through a 46-kDa protein located in the flagellar pocket.

Four lines of evidence indicate that a specific high affinity binding site on the surface of Leishmania donovani promastigotes mediates rapid internalization and degradation of hemoglobin. 1) Binding and uptake of 125I-hemoglobin by Leishmania followed saturation kinetics and were competed by unlabeled hemoglobin but not by globin or hemin or other heme- or iron-containing proteins. 2) Immunogold labeling studies revealed that, at 4 degreesC, hemoglobin binding was localized in the flagellar pocket of the promastigotes. Indirect immunofluorescence assays showed that, at 37 degreesC, the bound hemoglobin in such cells entered an endocytic compartment within 2 min and dispersed throughout the cell body by 15 min. 3) After incubation with hemoglobin-gold conjugates at 25 degreesC or 37 degreesC, the particles accumulated in discrete intracellular vesicles. 4) A single biotinylated protein of 46 kDa was revealed when solubilized membranes from surface biotinylated intact Leishmania adsorbed by hemoglobin-agarose beads were subjected to SDS-polyacrylamide gel electrophoresis and Western blotting with avidin-horseradish peroxidase. Considered together, these data indicate that this 46-kDa protein on the cell surface of L. donovani promastigotes mediates the binding of hemoglobin and its rapid internalization through a vesicular pathway characteristic of receptor-mediated endocytosis.