Antimicrobial sensitivity pattern of gram positive CSF isolates in children with septic meningitis in a Tertiary Care Hospital

The present study was conducted with the objective to determineantimicrobial susceptibility of Gram positive CSF isolates in septic meningitis in a tertiary care hospital. CSF (3-5 ml) was collected from 638 admitted children clinically suspected of septic meningitis. Bacterial isolates were identified and microbial sensitivity was assessed by the Kirby-Bauer’s disk diffusion method. Of the samples tested 102 (15.99%) were culture positive of which 45 (44.12%) culture positives were found inchildren aged 1-12 years. M: F ratio was 1.62:1. Maximum incidence (51 cases) was in summer-rainy season and in institutional delivery (58 cases). Primary immunization did not protect against septic meningitis. The isolates in 66 (64.71%) cases were Gram positive of which 36 (54.55%) were Streptococcus spp., 24 (36.36%) Staphylococcus aureus and 6 (9.09%) cases coagulase negative Staphylococcus (CONS). Both Streptococci and coagulase negative Staphylococci were highly sensitive (100%) to Linezolid, Vancomycin and Piperacillin-Tazobactam. However, Staphylococcus aureus were 100% sensitive to Linezolid and Vancomycin but were only 87.5% sensitive to Piperacillin-Tazobactam combination. The Streptococcus species showed a high degree of resistance to Tetracyclin91.67%, Co-trimoxazole 88.89% and Penicillin 63.89%. Staphylococcus aureus showed resistance to the tune of 83.33% each to Tetracycline and Co-trimoxazxole and 79.17% with Penicillin. In case of coagulase negative Staphylococcus, Co-trimoxazole showed resistance in 83.33%, Penicillin in 66.67% and Tetracycline in 50% cases. In septic meningitis Gram positive isolates predominate. Therapy should be based on trends of bacterial sensitivity

FLOW ANALYSIS ON DELTA WING – A REVIEW

Many aircraft, like fighters and bombers, are delta-winged aircraft. These aircraft have the characteristics of producing a greater lift at very small angles of attack even at very low Reynold’s number. Highly swept-wing aircraft experience greater lift due to the generation of the leading-edge vortex at a high angle of attack flight. The phenomena of vortex breakdown are noticed which leads to the reduction of the vortex lift and leads to the instability of the aircraft. This paper deals with an analysis of the flow on the delta wing with the existing literature and compares its benefits over the conventional wings using experimental and computational methods. The critical angles, pressure, and velocity variations are observed along with chord and spanwise locations

Ordered monolayer gold nano-urchin structures and their size induced control for high gas sensing performance

The synthesis of ordered monolayers of gold nano-urchin (Au-NU) nanostructures with controlled size, directly on thin films using a simple electrochemical method is reported in this study. In order to demonstrate one of the vast potential applications, the developed Au-NUs were formed on the electrodes of transducers (QCM) to selectively detect low concentrations of elemental mercury (Hg0) vapor. It was found that the sensitivity and selectivity of the sensor device is enhanced by increasing the size of the nanospikes on the Au-NUs. The Au-NU-12 min QCM (Au-NUs with nanospikes grown on it for a period of 12 min) had the best performance in terms of transducer based Hg0 vapor detection. The sensor had 98% accuracy, 92% recovery, 96% precision (repeatability) and significantly, showed the highest sensitivity reported to date, resulting in a limit of detection (LoD) of only 32 μg/m3 at 75 °C. When compared to the control counterpart, the accuracy and sensitivity of the Au-NU-12 min was enhanced by ~2 and ~5 times, respectively. The results demonstrate the excellent activity of the developed materials which can be applied to a range of applications due to their long range order, tunable size and ability to form directly on thin-films

Electron- and Hole-Doping Effects on AA-site Ordered NdBaMn2_2O6_6

We have investigated electron- and hole-doping effects on $A$-site ordered perovskite manganite NdBaMn$_2$O$_6$, which has the $A$-type (layered) antiferromagnetic (AFM) ground state. Electrons (holes) are introduced by partial substitution of Ba$^{2+}$ (Nd$^{3+}$) with Nd$^{3+}$ (Ba$^{2+}$). Electron-doping generates ferromagnetic (FM) clusters in the $A$-type AFM matrix. With increasing the electron-doping level, the volume fraction of the FM phase or the number of the FM clusters is abruptly increasing. In contrast, the $A$-type AFM phase is robust against the hole-doping, and no FM correlation is observed in the hole-doped NdBaMn$_2$O$_6$.Comment: 8 pages, 5 figures, to be published in Journal of the Physical Society of Japa

Electro-deposition of gold nano-structures on gold Quartz Crystal Microbalance (QCM) electrodes for enhanced mercury vapour sensitivity in the presence of interferent gasses

Gold electrode quartz crystal microbalances (QCMs) were used as transducing platform to detect and sense elemental mercury (Hg) in gas phase. The enhanced sensitivity, resulting form the electro-deposition of gold nano-structures on the surface is shown to increase the response magnitude (RM) of the sensors in the presence of ammonia and humidity interference. The concentration of NH3 and H2O was varied in the range 590 to 1770mg/m3 and 4.2 to 10.4mg/m3, respectively. A constant gas flow of 200sccm, balanced in nitrogen was used as the carrier gas. The RM for Hg was enhanced by creating nanostructures on the sensorpsilas gold electrodes via electro-deposition of gold in a lead acetate electrolyte. The results presented are a critical step in the development of a cheap regenerable and reliable sensor for measuring Hg in the presence of interferents gases commonly found in industrial applications

Cryptanalysis of an MPEG-Video Encryption Scheme Based on Secret Huffman Tables

This paper studies the security of a recently-proposed MPEG-video encryption scheme based on secret Huffman tables. Our cryptanalysis shows that: 1) the key space of the encryption scheme is not sufficiently large against divide-and-conquer (DAC) attack and known-plaintext attack; 2) it is possible to decrypt a cipher-video with a partially-known key, thus dramatically reducing the complexity of the DAC brute-force attack in some cases; 3) its security against the chosen-plaintext attack is very weak. Some experimental results are included to support the cryptanalytic results with a brief discuss on how to improve this MPEG-video encryption scheme.Comment: 8 pages, 4 figure

Development of nano-structured titanium oxide thin films using a gas carving technique

A method is developed for producing nano-structured titanium oxide thin films using H2 gas interaction with titanium thin film at a high temperature. These nano-structured thin films have been formed on a quartz crystal substrate. Titanium (Ti) thin films were deposited on the quartz crystal using a RF magnetron sputterer. The samples were placed in the oven at 500-800°C for 5 hours. The gas mixture of 1% H2 in N2 was introduced in the oven. The process of Ti annealing in the presence of H2 carves Ti films into nano-structure shapes. The process is a gas-solid interaction. Thin films were characterised using Scanning Electron Microscopes (SEM) and X-Ray Diffraction (XRD) technique. The nano structures formed have dimensions in a range of 25nm - 150nm obtained after gas carving

COUROUPITA GUIANENSIS LEAF CALLUS EXTRACT MEDIATED SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF SILVER NANOPARTICLES.

Objective: Synthesis of varied sized and morphologically distinct silver nanoparticles (AgNPs) using callus/callus extract, and their promising antibacterial and cytotoxicity was reported from very few plant systems. Here, we investigated silver nanoparticle synthetic potential of Couroupita guianensis leaf callus extract and their antibacterial activity.Methods: synthesis of callus mediated silver nanoparticles and characterisation of physical, chemical, and antibacterial activity of AgNPs.Results: Callus extract rapidly reduced silver ions and stabilized nanoparticles have displayed characteristic maximum UV absorbance at 410 nm. SEM and AFM images revealed their spherical morphology and size variation, which is ranged from 30.38 nm to 88.32 nm and were in small aggregates. Capping of AgNPs by the phenolic compounds and proteins revealed from FTIR spectral peaks. Silver nanoparticles displayed significantly high antimicrobial activity against both Gram positive and negative bacterial strains compared to silver ions and gentamicin. This enhanced antimicrobial activity of AgNPs may due their small size leading to efficient molecular contact with cell surface, and uptake and interaction with vital biomolecules.Conclusions: Stable AgNPs were synthesized through reduction and capping of silver ions by polyphenols and proteins present in callus extract. Theenhanced antimicrobial activity of AgNPs may due to their small size leading to efficient molecular contact with the cell surface, penetration, andinteraction, and inactivation of vital biomolecules.Â