Nano-biomaterials in Antimicrobial Therapy

Silver nanoparticles (AgNps) have attracted much interest in biomedical engineering, since they have excellent antimicrobial properties. Silver nanopolymer composites have applications in biochemical sensors, antimicrobial activity and drug delivery system. Silver nanoparticles are more effective than ionic homologues (Ag+) for their antimicrobial activity. Antimicrobial properties of silver nanoparticles are used by their incorporation into medical devices, tissues and other health-related products for skin pathologies to reduce the risk of contamination and to promote higher preventive infection control. Novel hybrid material thin films based on various polymeric systems with embedded silver nanoparticles were synthesized using various methods. The electrical, optical and plasmonic responses of AgNps onto thin layers of polymer composites show encapsulation of nanoparticles. The antibacterial activity of AgNps/polymer composites against various common bacteria is discussed in this chapter. The antibacterial activity of the synthesized hybrid materials was tested against various bacteria, commonly found in hospital environment. Silver nanostructures have especially been of interest because of contrast agents for biomedical image. Shunts used for hydrocephalous silicon elastomer grafted with hydrogel, polyvinylpyrrolidone (PVP) soaked in various antibiotics proved to be active for longer time

The Caenorhabditis elegans D2-like dopamine receptor DOP-2 physically interacts with GPA-14, a Gαi subunit

Dopaminergic inputs are sensed on the cell surface by the seven-transmembrane dopamine receptors that belong to a superfamily of G-protein-coupled receptors (GPCRs). Dopamine receptors are classified as D1-like or D2-like receptors based on their homology and pharmacological profiles. In addition to well established G-protein coupled mechanism of dopamine receptors in mammalian system they can also interact with other signaling pathways. In C. elegans four dopamine receptors (dop-1, dop-2, dop-3 and dop-4) have been reported and they have been implicated in a wide array of behavioral and physiological processes. We performed this study to assign the signaling pathway for DOP-2, a D2-like dopamine receptor using a split-ubiquitin based yeast two-hybrid screening of a C. elegans cDNA library with a novel dop-2 variant (DOP-2XL) as bait. Our yeast two-hybrid screening resulted in identification of gpa-14, as one of the positively interacting partners. gpa-14 is a Gα coding sequence and shows expression overlap with dop-2 in C. elegans ADE deirid neurons. In-vitro pull down assays demonstrated physical coupling between dopamine receptor DOP-2XL and GPA-14. Further, we sought to determine the DOP-2 region necessary for GPA-14 coupling. We generated truncated DOP-2XL constructs and performed pair-wise yeast two-hybrid assay with GPA-14 followed by in-vitro interaction studies and here we report that the third intracellular loop is the key domain responsible for DOP-2 and GPA-14 coupling. Our results show that the extra-long C. elegans D2-like receptor is coupled to gpa-14 that has no mammalian homolog but shows close similarity to inhibitory G-proteins. Supplementing earlier investigations, our results demonstrate the importance of an invertebrate D2-like receptor's third intracellular loop in its G-protein interaction

Remote Sensing of Mountain Glaciers and Related Hazards

Mountain glaciers are highly sensitive to temperature and precipitation fluctuations and active geomorphic agents in shaping the landforms of glaciated regions which are direct imprints of past glaciations, providing reliable evidence of the evolution of the past Cryosphere and contain important information on climatic variables. But most importantly, glaciers have aroused a lot of concern in terms of glacier area changes, thickness change, mass balance and their consequences on water resources as well as related hazards. The contribution of glacier mass loss to global sea-level rise and increasing number of glacier-related hazards are the most important and current socioeconomic concerns. Therefore, understanding the dynamics of the changes and constant monitoring of glaciers are essential for studying climate, water resource management and hydropower and also to predict and evade glacier-related hazards. The recent advances in the techniques of earth observations have proved as a boon for investigating glaciers and glacier-related hazards. Remote sensing technology enables extraction of glacier parameters such as albedo/reflectance/scattering, glacier area, glacier zones and facies, equilibrium line, glacier thickness, volume, mass balance, velocity and glacier topography. The present chapter explores the prospective of remote sensing technology for understanding and surveying glaciers formed at high, inaccessible mountains and glacier-induced hazards

Sharp bounds on Coefficient functionals of certain Sakaguchi functions

We determine sharp bounds on some Hankel determinants involving initial coefficients, inverse coefficients, and logarithmic inverse coefficients for two subclasses of Sakaguchi functions which are associated with the right half of the lemniscate of Bernoulli and the exponential function. Further, we compute sharp bounds on the second Hermitian-Toeplitz determinants involving logarithmic coefficients and logarithmic inverse coefficients. We also discuss invariant property for the obtained estimates with respect to various coefficients

Prevalence, Antibiotic Susceptibility Testing, Beta-Lactamase Production and mcr-1 Gene Detection in Uropathogenic Klebsiella Pneumoniae Isolated from A Tertiary Care Hospital in Bhopal: A Prospective Study

Introduction: Klebsiella pneumoniae (K pneumoniae) is an inhabitant of the nasopharynx and gastrointestinal tract and it is capable of causing a variety of infections, including urinary tract infection (UTI), pneumonia, liver abscess and septicemia. UTI in humans can be hospital and community-acquired. UTI should initially be treated with Co-trimoxazole, Nitrofurantoin, 1st generation cephalosporins, and Ciprofloxacin. Still, in India, frequent usage of broad-spectrum antibiotics such as cephalosporins, carbapenems and colistin for getting immediate response has led to resistance to these drugs. K pneumoniae possess several different mechanisms of drug resistance for survival. ESBL, MBL and AmpC beta-lactamase production is one of the dominant mechanisms to inactivate the beta-lactam antibiotics. UTI caused by MDR K pneumoniae is often treated with carbapenems and colistin. Inappropriate doses and frequent usage of these antibiotics make bacteria resistant therefore it is important to know about the susceptibility of antibiotics against K pneumoniae before giving broad-spectrum antibiotics in the local community for the better management of UTI. Methods: The present study is a prospective study. All clean-catch, mid-stream urine samples were collected in the sample collection centre from the patients suspecting UTI. Semi-quantitative culture method (SQCM) was used to isolate K pneumoniae. SQCM is a routinely used culture method as a diagnostic criterion for patients having a UTI. SQCM indicates the bacterial count present in the urine sample. Firstly, K pneumoniae was isolated and identified followed by Antimicrobial-susceptibility testing (AST). After the AST, double disc synergy test checked the production of ESBL, MBL and AmpC beta-lactamase. Lastly, colistin resistance in K pneumoniae was determined by the E-strip method and K pneumoniae strains positive by E-strip method were further screened for mcr-1 gene by PCR. Results: A total of 11740 urine samples were received and processed. 2465 (21%) samples showed significant growth of uropathogens. Out of all pathogens, 332 (13%) were identified as K pneumoniae.  Other 2133 (87%) pathogens were identified as Enterobacteriaceae members, Pseudomonas aeruginosa, Burkholderia, Acinetobacter baumannii, Enterococcus, and Staphylococcus. Of all the antibiotics we tested in our study, colistin (87%), carbapenems (78-79%) were the most and penicillin (00-43%) group was the least sensitive. ESBL, AmpC and MBL were 203 (61%), 126 (38%) and 83 (25%) respectively in K pneumonia. Colistin resistance was shown by 43 (13%) K pneumonia strains and out of these 43, only 08 (19%) strains were positive for mcr-1 gene

Surface Functionalization of TiO2 with Plant Extracts and their Combined Antimicrobial Activities Against E. faecalis and E. Coli

Abstract: The aim of this study is to enhance the antibacterial activity of TiO2 by pure plant extracts of Bauhinia variegata and Tinospora. cordifolia by making a composite of plant extract and TiO2. Plant extracts, TiO2 and plant extracts/TiO2 composites were investigated against two bacterial strain Enterococcus faecalis and Escherichia coli. X-ray diffraction investigations have confirmed the presence of TiO2 nanoparticles in the plant extract/TiO2 nanocomposites. UV-visible investigations have shown an enhanced photocatalytic activity of plant extract/TiO2 nanocomposites compared to that of pure TiO2 and pure plant extract. Plant extract/TiO2 nanocomposites have shown various level of antibacterial activity on different test microorganisms. The highest antibacterial potentiality expressed in terms of zone of inhibition (ZOI) in mm was exhibited by the aqueous extract of Bauhinia variegata /TiO2 (45 mm against Enterococcus faecalis and 30 mm against Escherichia coli) and benzene extract of Tinospora cordifolia /TiO2 (26 mm) nanocomposites. This is the first study on these types of bio-nano composite materials and it serves as basis for further research on these types of composite materials as a potent antibacterial agent

Chemical Beneficiation of Low Grade Coal - A Review

India is having large reserves of low grade coals. The use of low-grade coal in various industries like power plants, metallurgical plants, cement units etc. leads to environ-mental pollution because of generation of large amount of solid and gaseous pollutants. Therefore, it is of impor-tance paramount to clean the coal before its utilization. There are a number of upgrading technologies to produce clean coal. The current paper reviews demineralization aspects by physical and chemical beneficiation of high ash and/ sulfur containing coal.Physical beneficiation of coal is not very effective in separation of the finely dispersed minerals, whereas chemical beneficiation uses expensive reagents and leads to generation of large amount of waste-water which needs to be purified before discharge. Thus, a combined approach consisting of physical and chemical cleaning of coal appears to have a potential for. signifi-cant reduction of ash with less investment while generat-ing less polluting wastewater

Extraction of trivalent chromium from tannery effluent by ion exchange with indion 790 resin

Extraction of chromium(III) from a model tanning effluent has been studied by ion exchange using Indion 790 resin. The resin has been found to be selective for the sorption of chromium(III) in the pH range 0.5-3.5 from a model solution containing 500 ppm chromium(III). Beyond pH 3.5 extraction of chromium(III) drastically decreases from 92% to 76.5%. Sorption of chromium(III) on Indion 790 follows Freundlich isotherm indicating strong chemical interaction of the metal ion with the resin. Desorption of chromium(III) from the loaded resin increases with the increase in concentration of eluant (5-20% H2SO4). With 20% sulfuric acid solution 89% chromium(III) was eluted in two stages. The bench scale results are also validated in continuous mode in a fixed bed column for the recovery of chromium(III) from tannery effluent