Propellant Grade Hydrazine in Mono/Bi-propellant Thrusters: Preparation and Performance Evaluation

Propellant grade hydrazine was prepared with 64 per cent yield and 95.5 per cent purity. Purity of the propellant grade hydrazine was determined using wet chemical, gas chromatographic (GC) and eudiometric methods. It was observed that the compositions containing blends of hydrazine-methyl alcohol-ammonium nitrate and hydrazine-methyl alcohol-ammonium perchlorate were not found to be frozen even after cooling to -65 °C for 30 minutes. Mono and bi-propellant thrusters were designed and developed to demonstrate the performance of prepared propellant grade hydrazine as a promising rocket fuel. Five static tests with 22 N thruster and one static test with 1 N thruster were performed successfully in mono-propellant mode. The hurdles of chamber pressure oscillations were overcome by compact packing of the catalyst. The desired decomposition and chamber pressure were achieved. One static test was performed successfully with 60 N bi-propellant thruster. The desired chamber pressure and thrust were achieved. The combustion was smooth and C* achieved was higher than that of UH-25, N2O4 combination. The performance of prepared propellant grade hydrazine shows it as a promising rocket fuels.Defence Science Journal, Vol. 65, No. 1, January 2015, pp.31-38, DOI:http://dx.doi.org/10.14429/dsj.65.798

Role of magnetic resonance imaging in distinguishing fungal from nonfungal multiple brain abscesses

AbstractCladophialophora bantiana is a neurotropic dematiaceous fungus known for affecting immunocompromised and immunocompetent hosts. We report a case of 24year old immunocompetent male presenting with headache, fever and vomiting. MRI was suggestive of multiple fungal brain abscesses. He underwent total excision of abscesses. Pus culture was suggestive of brain abscess caused by C. bantiana. We report a culture proven case of C. bantiana emphasizing on specific MRI features which are critical in differentiating fungal from nonfungal brain abscesses

Tissue Microenvironments Define and Get Reinforced by Macrophage Phenotypes in Homeostasis or during Inflammation, Repair and Fibrosis

Current macrophage phenotype classifications are based on distinct in vitro culture conditions that do not adequately mirror complex tissue environments. In vivo monocyte progenitors populate all tissues for immune surveillance which supports the maintenance of homeostasis as well as regaining homeostasis after injury. Here we propose to classify macrophage phenotypes according to prototypical tissue environments, e.g. as they occur during homeostasis as well as during the different phases of (dermal) wound healing. In tissue necrosis and/or infection, damage- and/or pathogen-associated molecular patterns induce proinflammatory macrophages by Toll-like receptors or inflammasomes. Such classically activated macrophages contribute to further tissue inflammation and damage. Apoptotic cells and antiinflammatory cytokines dominate in postinflammatory tissues which induce macrophages to produce more antiinflammatory mediators. Similarly, tumor-associated macrophages also confer immunosuppression in tumor stroma. Insufficient parenchymal healing despite abundant growth factors pushes macrophages to gain a profibrotic phenotype and promote fibrocyte recruitment which both enforce tissue scarring. Ischemic scars are largely devoid of cytokines and growth factors so that fibrolytic macrophages that predominantly secrete proteases digest the excess extracellular matrix. Together, macrophages stabilize their surrounding tissue microenvironments by adapting different phenotypes as feed-forward mechanisms to maintain tissue homeostasis or regain it following injury. Furthermore, macrophage heterogeneity in healthy or injured tissues mirrors spatial and temporal differences in microenvironments during the various stages of tissue injury and repair. Copyright (C) 2012 S. Karger AG, Base

Comprehensive Proteomics Analysis of Stressed Human Islets Identifies GDF15 as a Target for Type 1 Diabetes Intervention

Type 1 diabetes (T1D) results from the progressive loss of β cells, a process propagated by pro-inflammatory cytokine signaling that disrupts the balance between pro- and anti-apoptotic proteins. To identify proteins involved in this process, we performed comprehensive proteomics of human pancreatic islets treated with interleukin-1β and interferon-γ, leading to the identification of 11,324 proteins, of which 387 were significantly regulated by treatment. We then tested the function of growth/differentiation factor 15 (GDF15), which was repressed by the treatment. We found that GDF15 translation was blocked during inflammation, and it was depleted in islets from individuals with T1D. The addition of exogenous GDF15 inhibited interleukin-1β+interferon-γ-induced apoptosis of human islets. Administration of GDF15 reduced by 53% the incidence of diabetes in NOD mice. Our approach provides a unique resource for the identification of the human islet proteins regulated by cytokines and was effective in discovering a potential target for T1D therapy

The dominant Anopheles vectors of human malaria in the Asia-Pacific region: occurrence data, distribution maps and bionomic précis

<p>Abstract</p> <p>Background</p> <p>The final article in a series of three publications examining the global distribution of 41 dominant vector species (DVS) of malaria is presented here. The first publication examined the DVS from the Americas, with the second covering those species present in Africa, Europe and the Middle East. Here we discuss the 19 DVS of the Asian-Pacific region. This region experiences a high diversity of vector species, many occurring sympatrically, which, combined with the occurrence of a high number of species complexes and suspected species complexes, and behavioural plasticity of many of these major vectors, adds a level of entomological complexity not comparable elsewhere globally. To try and untangle the intricacy of the vectors of this region and to increase the effectiveness of vector control interventions, an understanding of the contemporary distribution of each species, combined with a synthesis of the current knowledge of their behaviour and ecology is needed.</p> <p>Results</p> <p>Expert opinion (EO) range maps, created with the most up-to-date expert knowledge of each DVS distribution, were combined with a contemporary database of occurrence data and a suite of open access, environmental and climatic variables. Using the Boosted Regression Tree (BRT) modelling method, distribution maps of each DVS were produced. The occurrence data were abstracted from the formal, published literature, plus other relevant sources, resulting in the collation of DVS occurrence at 10116 locations across 31 countries, of which 8853 were successfully geo-referenced and 7430 were resolved to spatial areas that could be included in the BRT model. A detailed summary of the information on the bionomics of each species and species complex is also presented.</p> <p>Conclusions</p> <p>This article concludes a project aimed to establish the contemporary global distribution of the DVS of malaria. The three articles produced are intended as a detailed reference for scientists continuing research into the aspects of taxonomy, biology and ecology relevant to species-specific vector control. This research is particularly relevant to help unravel the complicated taxonomic status, ecology and epidemiology of the vectors of the Asia-Pacific region. All the occurrence data, predictive maps and EO-shape files generated during the production of these publications will be made available in the public domain. We hope that this will encourage data sharing to improve future iterations of the distribution maps.</p

Extraction and purification of tannase by reverse micelle system

Tannin acyl hydrolase commonly called as tannase (EC 3.1.1.20) is a commercially important enzyme. Partially purified and concentrated tannase is required for commercial applications. Typical objectives of purification process comprise high fold-purification, recovery and concentration. These objectives may be potentially conflicting. Conventional methods of purification require multiple steps which are time consuming and may cause higher loss. Reverse micellar extraction (RME) using ionic surfactants provides an attractive option for concentration and purification of tannase which is a highly hydrophilic glycoprotein. This study presents an optimized methodology for RME and purification of Aspergillus allahabadi intracellular tannase. Fold-purification, percent recovery and extraction time were the objective while the type and concentration of surfactant, contact time, pH, ionic strength, and the ratio of organic to aqueous phase were the decision variables. Some of these parameters were also studied for their effect on back-extraction. Among the surfactants tested, CTAB–isooctane system was found to be suitable. Under optimized conditions, 12.7-fold purification, 81.2% recovery and 3-fold concentration of tannase with a process time of 45 min was obtained. Conventional purification methods provided a higher fold-purification albeit at a much lower enzyme recovery. Further, the conventional method requires a process time of several hours

Efficient lipase purification using reverse micellar extraction

Reverse micellar extraction (RME) of enzyme provides an attractive option for conventional method with the potential to achieve purification and concentration in a single step with high yield. This study presents a methodology for optimization of RME with Pseudomonas lipase as model system. Fold-purification, percent recovery and extraction time were the objective functions while the type and concentration of surfactant, contact time, pH, ionic strength, and the ratio of organic to aqueous phase were the decision variables. Under optimized conditions, the AOT (Aerosol OT (bis 2-ethylhexyl) sodium sulfosuccinate)–isooctane system gave a 15-fold purification, 80% recovery and 2.5-fold concentration of the Pseudomonas lipase with process time of 45 min

Comparative Evaluation of Antibiotic Susceptibility Testing on Vitek-2 Compact and Direct Sensitivity Test from Blood Cultures from a Tertiary Care Centre in South India

Bloodstream infections (BSIs), recognized to be a major cause of morbidity and mortality globally, are increasing in incidence. India currently tackles an estimated 7,50,000 cases of BSI every year which includes 2% of hospitalized patients and 70% of patients admitted in the Intensive Care Unit. The associated crude mortality rate is 14-57%. Blood culture samples were subjected simultaneously to susceptibility testing by Direct Sensitivity Test (DST) by disk diffusion method and Antibiotic Sensitivity Test (AST) by Vitek-2 Compact (BioMerieux) a reference method from positive blood cultures flagged by BacT/ALERT 3D System, with the culture bottles FA and PA was used for blood culture. All the blood cultures flagged positive by BacT ALERT 3D system were included in the study. A total of 102 positive blood cultures showing monomicrobial gram-positive cocci or gram-negative bacilli identified after doing a Gram’s stain, were taken for further testing. A total of 102 blood cultures yielding mono-microbial bacterial growth were evaluated in this study. Organisms belonging to the family Enterobacteriaceae accounted for 41.2% of the isolates (42/102) followed by Staphylococcus spp. giving 40.2% of the isolates (41/102). E. coli and Klebsiella spp. were the commonest Gram negative isolates. These data suggest that VITEK 2 cards inoculated with samples taken directly from positive Bact/ALERT blood culture bottles would provide acceptable antimicrobial susceptibility testing results for Gram-negative bacilli, but not for Gram-positive cocci. Compared to the reference method, the direct method would reduce turnaround time by at least 24 h

Treating double-digit hyponatremia: walking a tight rope

We report the case of a diabetic patient who presented with severe hyponatremia (serum sodium concentration of 88 mEq/l) caused by hypovolemia and thiazide diuretic use. His serum sodium levels were gradually corrected using a combination of isotonic and hypotonic fluids based on urine output and rate of rise in sodium levels. The patient had complete recovery without any evidence of osmotic demyelination

Clinical Profile of Malaria in and around Hubballi-Dharwad: A Region of North Karnataka

Introduction: Malaria is an endemic vector borne parasitic infection. Plasmodium vivax has been associated with severe malaria while P. falciparum is traditionally associated with severe course. Of late, P. vivax is increasingly reported to cause severe and life threatening disease. However, majority of P. vivax are sensitive to antimalarials and therefore, it is important to speculate this pathogen. Aim: To study the clinical profile of confirmed malaria cases. Materials and Methods: This prospective study was undertaken at SDM College of Medical Sciences and Hospital, Dharwad, Karnataka, India, between the period of 2010 to 2012 for the duration of two years. A total of 124 clinically suspected malaria cases aged from 8 years to 65 years were included in the study. Laboratory identification was done by Quantitative Buffy Coat (QBC). A comparative analysis of clinical presentations in 62 QBC positive samples and an equal number of age and sex matched QBC negative was done. Results: Out of 62 QBC positive samples, Plasmodium vivax was seen in 40/62 (64.52%) patients while P. falciparum in 10/40 (16.13%) cases. Mixed infection by P. vivax and P. falciparum was seen in 12/40 (19.35%) cases. Fever, chills and headache were common symptoms. Pallor was seen in 23/40 (37.1%) cases and icterus, splenomegaly and vomiting were seen in 14/62 (22.6%) cases followed by hepatosplenomegaly in 11 (17.7%) cases. Among QBC negative controls, fever (100%), chills 51/62 (82.3%), rigors 21/62 (33.9%) and pain abdomen (24.2 %) were the common symptoms. Pallor and hepatomegaly was seen in 19.4 % and 11.3% respectively among the QBC negatives. Ten out of 11 (90.9%) of females and 37/51 (72.5%) of males suffering from malaria had anaemia. Thrombocytopenia was seen in 59/62 (95.2%) cases of which 33 cases had moderate thrombocytopenia (53.2%) while 17 cases had severe thrombocytopenia. In QBC negative controls, severe thrombocytopenia was noted in 4 (6.5%) samples, mild and moderate thrombocytopenia was seen in 14 and 16 (22.5 and 25.8%) patients respectively. About 94% cases recovered completely. One patient suffering from P. vivax succumbed to the infection. Conclusion: Plasmodium vivax, traditionally thought to cause benign malaria can also produce life threatening complications similar to falciparum malaria. Early recognition of signs and symptoms of severe malaria and laboratory confirmation of species is most important in management of this condition