557 research outputs found
Development of High-Resolution MT-InSAR System for Long-Term Infrastructure Monitoring
No full textA Master of Science thesis in Civil Engineering by Haifa Parayil Valappil entitled, “Development of High-Resolution MT-InSAR System for Long-Term Infrastructure Monitoring”, submitted in November 2025. Thesis advisor is Dr. Tarig Ali and thesis co-advisor is Dr. Mohammad AlHamaydeh. Soft copy is available (Thesis, Completion Certificate, Approval Signatures, and AUS Archives Consent Form)College of EngineeringDepartment of Civil EngineeringMaster of Science in Civil Engineering (MSCE
Spectrum of diffuse parenchymal lung diseases: An Experience from A Tertiary Care Referral Centre From South India
No full textBackground Diffuse parenchymal lung diseases (DPLDs) include the idiopathic interstitial pneumonias, hypersensitivity pneumonitis, connective tissue disease-related interstital lung disease (ILD), lymphangioleiomyomatosis, sarcoidosis, etc. The prevalence and outcome of DPLD is not studied well across India. The current study was aimed at studying clinical radiological spectrum of DPLD in India.
Aim The primary objective was to study the clinical radiological spectrum of DPLD, and the secondary objective was to identify the occurrence of idiopathic pulmonary fibrosis (IPF) and risk factors combined with IPF in a study population.
Materials and methods All patients diagnosed with DPLDs in department of pulmonary medicine during the study period were included. SPSS 20 version was used for doing statistical analysis. P value of less than 0.05 was considered statistically significant.
Results Mean age of the study cohort was 55±15.45 years. There were 83 (63.4%) female patients, and 11.6% of the patients gave history of prior antituberculosis medicine. Most common symptoms were gradually progressing dyspnoea (94.5%) followed by dry cough (78.29%). The commonest finding on chest radiograph in our series was reticulonodular pattern (80.2%). The commonest pattern on high-resolution computed tomography was fibrosis in interstitum (49.9%). The commonest cause of DPLD in study was connective tissue disorder (34.9%) followed by IPF (23.25%) and sarcoidosis (17.05%). Of all patients, 47 showed improvement on the six-minute walk test. Smoking was one of the major risk factor associated with IPF, and 66.7% of patients with IPF were smokers (P<0.001). The other risk factor associated with IPF was gastro esophageal reflux disease (GERD) (P=0.003).
Conclusions Connective tissue disease (CTD)-related ILD was the commonest DPLD followed by IPF and non specific interstitial pneumonitis (NSIP) in the present study. IPF was present in 23% of the cases. Smoking and GERD were the commonest risk factors associated with IPF
Fabrication and characterization of biodegradable poly(3-hydroxybutyrate) composite containing bioglass
No full textBacterially derived poly(3-hydroxybutyrate) (P(3HB)) has been used to produce composite films by incorporating Bioglass particles (<5 m) in 5 and 20 wt % concentrations. P(3HB) was produced using a large scale fermentation technique. The polymer was extracted using the Soxhlet technique and was found to have similar thermal and structural properties to the commercially available P(3HB). The effects of adding Bioglass on the microstructure surface and thermal and mechanical properties were examined using differential scanning calorimetry, dynamic mechanical analysis (DMA), X-ray diffraction, surface interferometry, electron microscopy, and nanoindentation. The addition of increasing concentrations of Bioglass in the polymer matrix reduced the degree of crystallinity of the polymer as well as caused an increase in the glass transition temperature as determined by DMA. The presence of Bioglass particulates reduced the Young's modulus of the composite. The storage modulus and the loss modulus, however, increased with the addition of 20 wt % Bioglass. A short period (28 days) in vitro bioactivity study in simulated body fluid confirmed the bioactivity of the composites, demonstrated by the formation of hydroxyapatite crystals on the composites' surface. <br/
Polyhydroxyalkanoate (PHA) biosynthesis from structurally unrelated carbon sources by a newly characterized Bacillus spp
No full textA newly acquired polyhydroxyalkanoate (PHA) producing Bacillus spp. was identified to be a strain of Bacillus cereus using a range of microbiological and molecular techniques. This strain, named B. cereus SPV, was found to be capable of using a wide range of carbon sources including glucose, fructose, sucrose, various fatty acids and gluconate for the production of PHAs, an advantage for the commercial production of the polymers. The media used for the polymer production was novel in the context of the genus Bacillus. The PHA, once produced, was found to remain at a constant maximal concentration, without any degradation, a great advantage for the commercial production of the PHAs. This particular strain of Bacillus spp. was able to synthesize various PHAs with 3-hydroxybutyrate (3HB), 3-hydroxyvalerate (3HV) and 4-hydroxybutyrate (4HB)-like monomer units from structurally unrelated carbon sources such as fructose, sucrose and gluconate. This is the first report of the incorporation of a 4HB related monomer containing PHA by the genus Bacillus and from structurally unrelated carbon sources. The PHAs isolated had molecular weights ranging between (0.4 and 0.8) × 106 and low polydispersity index values (MW/MN) ranging from 2.6 to 3.4
Nanoindentation testing of biodegradabale polymers
No full textNanoindentation testing of biodegradabale polymer
Polyhydroxyalkanoate biosynthesis in Bacillus cereus SPV under varied limiting conditions and an insight into the biosynthetic genes involved
No full textAims: A new strain of Bacillus, Bacillus cereus SPV, was found to be capable of using a wide range of carbon sources for the production of polyhydroxyalkanoates (PHAs) (Valappil et al. 2007b). Limiting nutrient in the culture conditions is crucial for PHA production. In this study, B. cereus SPV was grown in different culture conditions with limitation of potassium, nitrogen, sulphur and phosphorous to establish the impact of nutritional limitation on PHA production.
Methods and Results: The PHA yields obtained were found to be 13·4, 38, 13·15 and 33·33% dcw for potassium, nitrogen, sulphur and phosphorus limitations, respectively. Gas chromatography–mass spectrometry analysis of the isolated polymers showed the presence of P(3HB) under nitrogen, sulphur and phosphate-limiting conditions and P(3HB-3HV) copolymer under potassium limiting conditions. This ability of B. cereus SPV to accumulate different PHA monomers from structurally unrelated carbon sources led to an interest in the molecular analysis of PHA biosynthesis in this organism. To achieve this, PCR was used to identify the polyhydroxyalkanoate biosynthetic genes in B. cereus SPV.
Conclusion: Sequence analysis of the PCR products from B. cereus SPV revealed the sequence of the putative biosynthetic genes, and possible regions involved in substrate binding
Effect of silver content on the structure and antibacterial activity of silver-doped phosphate-based glasses
No full textStaphylococcus aureus can cause a range of diseases, such as osteomyelitis, as well as colonize implanted medical devices. In most instances the organism forms biofilms that not only are resistant to the body's defense mechanisms but also display decreased susceptibilities to antibiotics. In the present study, we have examined the effect of increasing silver contents in phosphate-based glasses to prevent the formation of S. aureus biofilms. Silver was found to be an effective bactericidal agent against S. aureus biofilms, and the rate of silver ion release (0.42 to 1.22 µg·mm–2·h–1) from phosphate-based glass was found to account for the variation in its bactericidal effect. Analysis of biofilms by confocal microscopy indicated that they consisted of an upper layer of viable bacteria together with a layer (20 µm) of nonviable cells on the glass surface. Our results showed that regardless of the silver contents in these glasses (10, 15, or 20 mol%) the silver exists in its +1 oxidation state, which is known to be a highly effective bactericidal agent compared to that of silver in other oxidation states (+2 or +3). Analysis of the glasses by 31P nuclear magnetic resonance imaging and high-energy X-ray diffraction showed that it is the structural rearrangement of the phosphate network that is responsible for the variation in silver ion release and the associated bactericidal effectiveness. Thus, an understanding of the glass structure is important in interpreting the in vitro data and also has important clinical implications for the potential use of the phosphate-based glasses in orthopedic applications to deliver silver ions to combat S. aureus biofilm infections
IMSA Gardens
No full textTo combat the rise of food deserts and create more sustainable and healthy communities, IMSA Gardens (founded by Solange Simpson, Mridhul Valappil, and Elijah Nagel) is providing less fortunate communities access to healthy and affordable foods. Thousands of communities all across the country can benefit from IMSA Gardens’ unique and affordable meal plans that are grown natural with homemade fertilizer in environmentally friendly gardens. IMSA Gardens has the well-being of the less fortunate communities everywhere at heart, which is why they choose to place a vast majority of the profits back into the cause of creating more healthy and sustainable communities by expanding and innovating upon the gardens to reach more people.These monthly meal subscription boxes will have a major impact upon those that live within food deserts, providing them with a more sustainable lifestyle that has a positive impact upon both their health and wallet. IMSA Gardens strives to eventually inspire sustainable communities and cities all across the country by providing their service to as many as possible, through its driving purpose, which is “In order to build sustainable communities that can thrive, we must provide an alternative service that communities may use to better sustain themselves through the use of community gardens
Development of polyhydroxyalkanoates/Bioglass® composite tissue scaffolds for tissue engineering applications
No full text: a point prevalence study
No full textObjectivesOccult (surface antigen-negative/DNA-positive) hepatitis B virus (HBV) infection is common in areas of the world where HBV is endemic. The main objectives of this study were to determine the prevalence of occult HBV infection in HIV-infected African migrants to the UK and to determine factors associated with occult coinfection.MethodsThis anonymized point-prevalence study identified Africans attending three HIV clinics, focussing on patients naïve to antiretroviral therapy (ART). Stored blood samples were tested for HBV DNA. Prevalence was calculated in the entire cohort, as well as in subpopulations. Risk factors for occult HBV coinfection were identified using logistic regression analysis.ResultsAmong 335 HIV-positive African migrants, the prevalence of occult HBV coinfection was 4.5% [95% confidence interval (CI) 2.8–7.4%] overall, and 6.5% (95% CI 3.9–10.6%) and 0.8% (95% CI 0.2–4.6%) in ART-naïve and ART-experienced patients, respectively. Among ART-naïve anti-HBV core (anti-HBc)-positive patients, the prevalence was 16.4% (95% CI 8.3–25.6%). The strongest predictor of occult coinfection was anti-HBc positivity [odds ratio (OR) 7.4; 95% CI 2.0–27.6]. Median HBV DNA and ALT levels were 54 IU/mL [interquartile range (IQR) 33–513 IU/mL] and 22 U/L (IQR 13–27 U/L), respectively.ConclusionsOccult HBV coinfection remains under-diagnosed in African HIV-infected patients in the UK. Given the range of HBV DNA levels observed, further studies are warranted to determine its clinical significance and to guide screening strategies and ART selection in these patients
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