939 research outputs found
Large-scale Synthesis and Functional Elements for the Antimicrobial Activity of Defensins
Human neutrophil defensins, and their analogues incorporating anionic, hydrophobic or cationic residues at the N- and C-termini, were synthesized by solid-phase procedures. The synthetic defensins were examined for their microbicidal activity against Candida albicans, two Gram-negative bacteria (Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis) and two Gram-positive bacteria (Streptococcus gordonii and Streptococcus mutans). The human neutrophil peptide 1 (HNP1) and HNP2 were found to be potent candidacidal agents. HNP3, which differs by one amino acid at the N-terminus of its sequence, was totally inactive. The Gram-negative bacteria A. actinomycetemcomitans and P. gingivalis and the Gram-positive bacteria S. gordonii and S. mutans were insensitive to human defensins. However, the insertion of two basic residues, such as arginine, at both the N-terminus and the C-terminus of HNP2 significantly enhanced antifungal and antibacterial activity. The addition of anionic residues, such as aspartic acid, at the N- and C-termini rendered the molecule totally inactive. The presence of two hydrophobic amino acids, such as valine, at the N-terminus of HNP2 and of two basic arginine residues at its C-terminus resulted in molecules that were optimally active against these oral pathogens. The results suggest that the N- and C-terminal residues in defensin peptides are the crucial functional elements that determine their microbicidal potency. The three-dimensional structure of all defensins constitutes the same amphiphilic beta-sheet structure, with the polar face formed by the N- and C-terminal residues playing an important role in defining microbicidal potency and the antimicrobial spectrum. The enhanced microbicidal activity observed for defensin peptides with two basic residues at both the N- and C-termini could be due to optimization of the amphiphilicity of the structure, which could facilitate specific interactions with the microbial membranes
Purification and characterization of hyaluronic acid produced by Streptococcus zooepidemicus strain 3523-7
Hyaluronic acid (HA) is a hydrated gel and comprises repeating units of glucuronic acid and N-acetylglucosamine. Production and recovery of HA has gained great importance due to its vast clinical applications. In pursuit of obtaining highly pure HA, we have developed a fed-batch fermentation process using Streptococcus zooepidemicus in a 25 L bioreactor that resulted in a maximum yield of 2.3 g/L HA. In addition, we have devised an efficient method for separation and recovery of hyaluronic acid from a highly viscous broth by treating with trichloroacetic acid (0.1%) and charcoal (1-2%), passing through filtration (0.45 μm) and ultrafiltration that resulted in recovery of 72.2% of clinical grade HA with molecular weight of 2.5×106 Da. We have also characterized our purified HA using FTIR and NMR spectroscopy. These studies revealed the similarity in both the FTIR spectrum as well as NMR spectrum of both reference standard and purified HA from S. zooepidemicus indicating that the reported process is more efficient in terms of better yield and high quality (99.2%)
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Techno-Economic Analysis of Hybrid Layered Manufacturing
Subtractive manufacturing (CNC machining) has high quality of geometric and
material properties but is slow, costly and infeasible in some cases; additive
manufacturing (RP) is just the opposite. Total automation and hence speed is
achieved in RP by compromising on quality. Hybrid Layered Manufacturing
(HLM) developed at IIT Bombay combines the best features of both these
approaches. It uses arc welding for building near-net shapes which are finish
machined to final dimensions. High speed of HLM surpasses all other processes
for tool making by eliminating NC programming and rough machining. The
techno-economic viability of HLM process has been proved through a real life
case study. Time and cost of tool making using HLM promises to be substantially
lower than that of CNC machining and other RP methods. Interestingly, the
material cost in HLM was also found to be lower. HLM is a cheaper retrofitment
to any 3 or 5 axis CNC milling machine or machining center.Mechanical Engineerin
A prospective study on maternal and perinatal outcome of gestational diabetes mellitus
Background: To identify risk factors, study maternal, fetal and perinatal outcome of pregnancy in relation to the glycemic control and different modalities of management in pregnancy complicated by Gestational Diabetes Mellitus (GDM).Methods: Descriptive study conducted in Department of OBG, Government TD Medical College Alappuzha, during the one year period January 2005 to December 2005. Study group comprised of 134 women who are diagnosed to have GDM. The aim was to study the maternal, fetal and perinatal outcome.Results: Despite early diagnosis and treatment the GDM patients in the present study had a statistically significant higher incidence of pregnancy induced hypertension (11.9%) induction of labor about (37.2%), caesarean section (58.96%) preterm delivery (2.99%) macrosomia (2.9%). Incidence of perinatal morbidity was 29.8%, common causes being neonatal hypoglycemia (32.5%), hyperbilirubinemia (12.5%) meconium aspiration syndrome (7.5%). Admission to neonatal unit required in (25%). There were 2 cases of intrauterine deaths, 2 cases of neonatal deaths and no still births. Perinatal mortality was 2.9%.Conclusions: The occurrence of GDM is a high-risk situation. Maternal morbidity, perinatal morbidity and mortality are increased in women with GDM. All pregnant women should be screened for GDM with a 50gm oral glucose load followed by a glucose determination 1 hour later. This helps to detect all GDM cases earlier and so timely intervention can be done which will reduces the complications. Proper management of GDM during the antenatal period will improve pregnancy outcome
Impact of Bt cotton technology in an Indian cotton production system: A comparative econometric analysis between Maharashtra and Tamil Nadu
Cotton is one of India's most important commercial crops, known as the "White Gold." India has the largest area under cotton production with comparatively low productivity, owing to the enormous area under rainfed agriculture with insufficient input supply, implying inefficient resource usage. The present study measures the resource use efficiency and technical efficiency of Bt cotton production in Tamil Nadu in comparison with one of the major cotton-producing states, Maharashtra. The resource use efficiency was calculated using the Cobb–Douglas production function, and the stochastic frontier approach is deployed to estimate technical efficiency. Resource use efficiency analysis indicated that the majority of resources are being used at suboptimal levels, and there is the potential to increase cotton production by reaching the most profitable level of input use. However, frontier analysis confirmed that production was inefficient, with a greater gap in which both Tamil Nadu and Maharashtra, particularly small and marginal farms, need to be addressed to increase production and farm income. The results indicated that the mean technical efficiency among Bt and non-Bt farmers was 94 % and 76 % in Tamil Nadu and 97 % and 74 %, implying the potential to increase cotton production with the current level of resources and technology. This study suggested a development policy aimed at stimulating extension activity through motivation to provide rural farm households with the necessary farm management skills to boost productivity]
Effect of blend ratio and single, double and plated yarn on moisture management properties of bamboo/cotton jersey knitted fabrics
Effect of bamboo/cotton blend ratio on the moisture management properties of single, double and plated yarn singlejersey knitted fabrics has been studied. The moisture management properties of the fabrics are measured by SDL-ATLASmoisture management tester. Absorption rate, wetting time, maximum wetted radius, spreading speeds, one-waytransportation capability and overall moisture management capacity are measured and discussed. The results show that thebamboo composition has a significant influence on moisture management properties
Environmental Impacts of Sediment Nutrients in Hyper Eutrophic Reservoir in South India
Source: ICHE Conference Archive - https://mdi-de.baw.de/icheArchiv
Poetical discourse analysis of a Tamil song Ovvoru Puukkalumee
This study is an attempt to analyze the Tamil movie song ‘Ovvoru PuukkaLumee ’ meaning ‘every flower’ from the Tamil movie 'Autograph'. This song is one of the popular songs of P. Vijay, a Tamil lyricist. The texture discourse of this song will be analyzed in terms of grammatical and lexical usages found by making use of discourse analysis
Development of a New RP-UPLC Method for the Determination of Rabeprazole Sodium in Pharmaceutical Formulation and Application in Dissolution Studies
Purpose: To develop a reverse phase ultra-performance liquid chromatographic (RP-UPLC) method for the estimation of rabeprazole sodium in tablet formulations.Methods: Chromatographic separation was achieved on a Waters Acquity BEH C18 (50 x 2.1 mm, particle size 1.7 μm) column using an isocratic method with mobile phase composed of acetonitrile and phosphate buffer (pH 7.4) in the ratio of 35:65 (v/v). The flow rate was 0.4 ml/min, temperature of the column was maintained at ambient, injection volume was 5 μL and detection was made at 280 nm. The run time was as short as 2 min. Comparison of system performance with conventional HPLC was made with respect to analysis time, efficiency and sensitivity.Results: The developed method was linear for rabeprazole sodium from 0.03 - 30 μg/ml and the linear regression obtained was > 0.999. Precision, evaluated by intra- and inter-day assay,s had relative standard deviation (R.S.D) values within 1.5 %. Recovery data were in the range 98.0 - 101.5 % with R.S.D. values < 1.5 %.Conclusion: The method is precise, accurate, linear, robust and fast. The short retention time of 1.49 min allows the analysis of a large number of samples in a short period of time and, therefore, should be cost-effective for routine analysis in the pharmaceutical industry.Keywords: Ultra performance liquid chromatography, Assay, Rabeprazole sodium, Validatio
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