Assessment of water quality of River Ganges during Kumbh mela 2010

In the present study the water quality of Ganga River was assessed during Maha Kumbh-2010.  River water samples were collected from five sites.  Various Physico-Chemical and microbiological parameters were analysed. It was observed that all parameters were within the permissible limit according to WHO (2009) and BIS (2004) except most probable number that is the indication of low sanitary condition and it can further lead to the outbreak of diseases. During this mass bathing two sites were found to be more affected than the other three sites. These were noted to Har-ki-pauri and Mayapur ghat at Haridwar, at these sites parameters are observed to be slightly raised in comparison to other three sites

Clinical benefits of preemptive oral clonidine versus oral tramadol for abdominal hysterectomy conducted under subarachnoid block with 0.5% hyperbaric bupivacaine: a comparative evaluation

Background: Neuraxial techniques possess many benefits for elective abdominal hysterectomy due to profound surgical anesthesia and muscle relaxation. The present study was aimed to compare the clinical benefits of pre-emptive oral clonidine with oral tramadol for abdominal hysterectomy conducted under subarachnoid block with 0.5% hyperbaric bupivacaine.Methods: Sixty adult female patients of American Society of Anaesthesiologists (ASA) physical status I and II, aged 42 to 65 years, were randomized into two groups of 30 patients each to receive either oral clonidine, 100 µg (Group C) or oral tramadol 50 mg tramadol (Group T), 90 min before initiation of subarachnoid block with 3.5 mL of 0.5% hyperbaric bupivacaine. Intraoperative hemodynamic changes, duration of analgesia and incidence of shivering were recorded as primary end points. Drug related effects of pruritus, sedation, nausea, vomiting, and respiratory depression were recorded as secondary outcomes.Results: The onset of sensory and motor block was comparable between the groups but the time to two dermatome regression were prolonged in patients of Group C with statistical significant difference (p=0.05). Duration of analgesia was also enhanced in patients of Group C (268.27±12.18 min versus 223.15±14.31 min in Group T) with statistically highly significant difference (p=0.000). The incidence of shivering was lower in the patients of clonidine group. The heart rate was lower in patients of clonidine throughout intraoperative period and no incidence of bradycardia, hypotension or sedation occurred in any patient.Conclusions: Both drugs showed clinical benefits as pre-emptive oral medication for abdominal hysterectomy conducted under subarachnoid block but oral clonidine (100 µg) proved to be more beneficial

Boron Nitride Fabrication Techniques and Physical Properties

The III-nitride semiconductors are known for their excellent extrinsic properties like direct bandgap, low electron affinity, and chemical and thermal stability. Among III-nitride semiconductors, boron nitride has proven to be a favorable candidate for common dimension materials in several crystalline forms due to its sp2- or sp3-hybridized atomic orbitals. Among all crystalline forms, hexagonal (h-BN) and cubic (c-BN) are considered as the most stable crystalline forms. Like carbon allotropes, the BN has been obtained in different nanostructured forms, e.g., BN nanotube, BN fullerene, and BN nanosheets. The BN nanosheets are a few atomic layers of BN in which boron and nitrogen are arranged in-planer in hexagonal form. The nanostructure sheets are used for sensors, microwave optics, dielectric gates, and ultraviolet emitters. The most effective and preferred technique to fabricate BN materials is through CVD. During the growth, BN formation occurs as a bottom-up growth mechanism in which boron and nitrogen atoms form a few layers on the substrate. This technique is suitable for high quality and large-area growth. Although a few monolayers of BN are grown for most applications, these few monolayers are hard to detect by any optical means as BN is transparent to a wide range of wavelengths. This chapter will discuss the physical properties and growth of BN materials in detail

Recent Advancements in GaN LED Technology

Gallium nitride (GaN)-based solid state lighting technology has revolutionized the semiconductor industry. The GaN technology has played a crucial role in reducing world energy demand as well as reducing the carbon footprint. As per the reports, the global demand for lighting has reduced around 13% of total energy consumption in 2018. The Department of Energy (USA) has estimated that bright white LED source could reduce their energy consumption for lighting by 29% by 2025. Most of the GaN LEDs are grown in c-direction, and this direction gives high growth rate and good crystal integrity. On the other hand, the c-plane growth induces piezoelectric polarization, which reduces the overall efficiency of LEDs since the last decade researchers round the globe working on III-N material to improve the existing technology and to push the limit of III-V domain. Now, the non-polar and semi-polar grown LEDs are under investigation for improved efficiency. With the recent development, the GaN is not only limited to lighting, but latest innovations also led the development of micro-LEDs, lasers projection and point source. These developments have pushed GaN into the realm of display technology. The miniaturization of the GaN-based micro-LED and integration of GaN on silicon driving the application into fast response photonic integrated circuits (ICs). Most of the recent advancements in GaN LED field would be discussed in detail

Improved protocol for plasma microRNA extraction and comparison of commercial kits

MicroRNAs are small, non-coding RNA molecules that are becoming popular biomarkers in several diseases. However, their low abundance in serum/plasma poses a challenge in exploiting their potential in clinics. Several commercial kits are available for rapid isolation of microRNA from plasma. However, reports guiding the selection of appropriate kits to study downstream assays are scarce. Hence, we compared four commercial kits to evaluate microRNA-extraction from plasma and provided a modified protocol that further improved the superior kit’s performance. We compared four kits (miRNeasy Serum/Plasma, miRNeasy Mini Kit from Qiagen; RNA-isolation, and Absolutely-RNA MicroRNA Kit from Agilent technologies) for quality and quantity of microRNA isolated, extraction efficiency, and cost-effectiveness. Bioanalyzer-based Agilent Small RNA kit was used to evaluate quality and quantity of microRNA. Extraction efficiency was evaluated by detection of four endogenous control microRNA using real-time-PCR. Further, we modified the manufacturer’s protocol for miRNeasy Serum/Plasma kit to improve yield. miRNeasy Serum/Plasma kit outperformed the other three kits in microRNA-quality (P < 0.005) and yielded maximum microRNA-quantity. Recovery of endogenous control microRNA i.e. hsa-miR-24-3p, hsa-miR-191-5p, hsa-miR-423-5p and hsa-miR-484 was higher as well. Modification with the inclusion of a double elution step enhanced yield of microRNA extracted with miRNeasy Serum/Plasma kit significantly (P < 0.001). We demonstrated that miRNeasy Serum/Plasma kit outperforms other kits and can be reliably used with a limited plasma quantity. We have provided a modified microRNA-extraction protocol with improved microRNA output for downstream analyses

Influence of growth temperature on structural and optical properties of laser MBE grown epitaxial thin GaN films on a-plane sapphire

Epitaxial thin GaN films (similar to 60 nm) have been grown on a-plane sapphire substrates at different growth temperatures (500-700 degrees C) using laser molecular beam epitaxy (LMBE). The effect of growth temperatures on the structural and optical properties of GaN layers grown on low temperature (LT) GaN buffer on prenitridated a-sapphire have been studied systematically. The in situ reflection high energy electron diffraction pattern revealed the three-dimensional epitaxial growth of GaN films on a-sapphire under the adopted growth conditions. The full width at half maximum (FWHM) value of x-ray rocking curves (XRCs) along GaN (0002) and (10-12) planes decreases with increasing growth temperature. The FWHM values of (0002) and (10-12) XRC for the 700 degrees C grown GaN film are 1.09 degrees and 1.08 degrees, respectively. Atomic force microscopy characterization showed that the grain size of GaN increases from 30-60 to 70-125 nm with the increase in growth temperature as GaN coalescence time is shorter at high temperature. The refractive index value for the dense GaN film grown at 600 degrees C is obtained to be similar to 2.19 at the wavelength of 632 nm as deduced by spectroscopic ellipsometry. Photoluminescence spectroscopy confirmed that the epitaxial GaN layers grown on a-sapphire at 600-700 degrees C possess near band edge emission at similar to 3.39 eV, close to bulk GaN. The GaN growth at 700 degrees C without a buffer still produced films with better crystalline and optical properties, but their surface morphology and coverage were inferior to those of the films grown with LT buffer. The results show that the growth temperature strongly influences the structural and optical quality of LMBE grown epitaxial GaN thin films on a-plane sapphire, and a growth temperature of >600 degrees C is necessary to achieve good quality GaN films. Published by the AVS

Elaboration of self-healing polymer membranes

L'objectif de cette thèse est d'élaborer et de développer un type de membranes polymères qui peuvent se réparer de manière autonome en cas de fissures. Si elles ne sont pas détectées, ces fissures peuvent poser des problèmes notamment pour des applications médicales. Dans une première partie, une membrane polymère dynamique à base de micelles de copolymère tribloc ABA a été préparée. Le bloc "A" est représenté par le poly (styrene-co-acrylonitrile), copolymère bloc mécaniquement robuste, et un bloc "B" relativement mou et souple, le poly (ethylene oxide). Lorsqu'une pression est appliquée à la membrane, sa morphologie peut être ajustée grâce à la nature compressible des micelles, ainsi que les ponts dynamiques intermicellaires. Une gamme de porosités accessible peut être régulée par la pression et de manière à contrôler la performance de filtration. La même nature dynamique a également été utilisée pour montrer une réparation autonome entrainée par la pression. L'efficacité du processus de réparation dépend de la taille des fissures, de la valeur de pression et de la durée d'application de la pression. En utilisant la propriété d'auto-réparation de la membrane ci-dessus, le processus « Direct Mode Translocation » de nanoparticules a également été étudié. Quatre classes différentes de nanoparticules ont été utilisées avec diverses propriétés intrinsèques et extrinsèques. Les conclusions de ces travaux prouvent que les caractéristiques de taille, de forme et de surface des nanoparticules ainsi que la force exercée régissent le processus de translocation. Dans une seconde partie, un revêtement 2D et 3D réversible basé sur l'auto-assemblage de micelles de copolymère dibloc constitué d'un poly (methyl methacrylate) (PMMA) et du poly (n-octadecyl methacrylate) (PODMA) blocs a été développé. L'assemblage de micelles est réalisé par l'effet "Zipper", grâce aux longues chaînes pendantes du bloc PODMA. Le même effet "Zipper" permet d'enlever facilement le revêtement par lavage dans un solvant sélectif, donnant ainsi la possibilité de modifier la surface d'un substrat plusieurs fois de manière réversible. La cristallisation à température ambiante du bloc PODMA offre la possibilité d'avoir un revêtement auto-réparable thermiquement sans affecter la morphologie globale des micelles. Enfin, une dernière partie a été conceptualisée, dans laquelle l'auto-réparation se fait par « nano-gel » encapsulés et dispersés dans une membrane. Le « nano-gel » est à base d'un copolymère hydrophile en forme d'une étoile partiellement réticulée et qui doit être synthétisée par la technique de "Reversible Addition-Fragmentation Transfer" (RAFT) polymérisation. La synthèse d'un agent RAFT avec 4 bras pour la polymérisation a été accomplie, cependant, des travaux sont encore nécessaires pour valider la voie de synthèse vers la synthèse de « nano-gel » ainsi que son application pour le processus d'auto-réparation.The objective of this thesis is to develop such kind of polymeric membranes which can repair themselves autonomously in an event of damage. Such damage in a membrane, if left undetected can pose serious health issues in some of the intended applications. In the first approach, a dynamic polymeric membrane based on ABA type triblock copolymer micelles has been prepared. The block “A” is represented by mechanically robust poly(styrene-co-acrylonitrile) copolymer while block “B” by relatively soft and flexible poly(ethylene oxide). When pressure is applied to the membrane, its morphology can be fine-tuned thanks to the compressible nature of micelles as well as intermicellar dynamic bridges. A range of porosities are accessible which can be regulated by pressure and thereby controlling the filtration performance. The same dynamic nature has also been utilized to display an effective pressure driven autonomous healing. The efficiency of healing process has been found to be dependent on the extent of damage, pressure value and time duration of application of pressure. Using the self-healing property of above membrane, “Direct Mode Translocation” of nanoparticles has also been studied. Four different classes of nanoparticles were used with varied intrinsic and extrinsic properties. The findings of the work prove that the size, shape and surface characteristics of the nanoparticles as well as the applied force govern the translocation process. In a second approach, a 2D and 3D reversible coating based on the self-assembly of micelles of diblock copolymer consisting of poly(methyl methacrylate) (PMMA) and poly(n-octadecyl methacrylate) (PODMA) blocks have been developed. The assembly of micelles is accomplished via so called “Zipper” effect, thanks to the long pendant chains of PODMA block. The same “zipper” effect plays the role of removing the coating easily by washing in a selective solvent, thus giving the ability to alter the surface of substrate for many times in reversible manner. The room temperature crystallization of PODMA block provides huge implications for a thermally assisted self-healing coating without affecting the global micelle morphology. Finally, another approach has been conceptualized in which self-healing occurs via encapsulated nano-gel dispersed within a membrane. The nano-gel is based on a partially crosslinked hydrophilic star shaped block copolymer which has to be synthesized by “Reversible Addition-Fragmentation Transfer” (RAFT) polymerization technique. The synthesis of a 4- arm RAFT agent for polymerization has been accomplished however ; a substantial amount of work is still needed to validate the synthetic route towards the nano-gel synthesis as well as its further application for the self-healing process

Data Lakes: The Biggest Big Data Challenges

Why data lakes are an important piece of the overall big data strategy

To study the correlation of symptoms of angina with the diagnosis of ST Segment Elevation Myocardial Infarction (STEMI)

Introduction: Chest pain is amongst the commonest causes of visits to the emergency department. A rapid assessment with a prompt evaluation with an electrocardiogram clinches the diagnosis in most cases. However, with ever increasing strain on our limited resources, patient reported symptoms are central to initial assessment and must decide the course of action. Although considered ominous signs requiring further, often emergent, assessment, data on correlation of symptoms of angina with ST segment elevation is limited in contemporary literature. Methodology: 230 patients with biomarker proven ST segment elevation myocardial infarction (STEMI) were studied and assessed for frequency of the four, patient reported, cardinal symptoms of angina, namely retrosternal chest discomfort, diaphoresis, palpitations and radiation. We assessed the relative presence or absence of these supposedly cardinal symptoms of angina and set out to classify the most important symptoms of angina. Results: Our study shows that presence of three or more above symptoms is associated with a much higher possibility of an actual STEMI as opposed to only one symptom. Furthermore, a measurable increase in the probability of MI exists, when the number of patient reported symptoms increases from none to all four, as mentioned above. Though the study also reaffirmed the association between hypertension and Type 2 Diabetes Mellitus with acute coronary syndromes, our study was neither powered, nor designed to study this association. Conclusions: Patient reported symptoms have a direct and additive correlation with STEMI. A quick but detailed history in the emergency department is of paramount importance to identify high risk patients