Acid-catalysed Hydrolysis of N-Phenyl-n-butyrohydroxamic Acid

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Pressure induced electronic topological transition in Sb2S3

Pressure induced electronic topological transitions in the wide band gap semiconductor Sb2S3 (Eg = 1.7-1.8 eV) with similar crystal symmetry (SG: Pnma) to its illustrious analog, Sb2Se3, has been studied using Raman spectroscopy, resistivity and the available literature on the x-ray diffraction studies. In this report, the vibrational and the transport properties of Sb2S3 have been studied up to 22 GPa and 11 GPa, respectively. We observed the softening of phonon modes Ag(2), Ag(3) and B2g and a sharp anomaly in their line widths at 4 GPa. The resistivity studies also shows an anomaly around this pressure. The changes in resistivity as well as Raman line widths can be ascribed to the changes in the topology of the Fermi surface which induces the electron-phonon and the strong phonon-phonon coupling, indicating a clear evidence of the electronic topological transition (ETT) in Sb2S3. The pressure dependence of a/c ratio plot obtained from the literature showed a minimum at ~ 5 GPa, which is consistent with our high pressure Raman and resistivity results. Finally, we give the plausible reasons for the non-existence of a non-trivial topological state in Sb2S3 at high pressures.Comment: 24 pages, 6 Figures, 2 tables submitted for publicatio

Evaluation of neutropenia and neutrophilia in preterm infants

OBJECTIVE: Neutrophil counts are used routinely as part of the sepsis evaluation in newborn infants. In this article, we review the normal blood neutrophil concentrations and the clinical approach to neutropenia and neutrophilia in the neonatal period. METHODS: A literature search was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies. RESULTS: Neutropenia and neutrophilia are documented frequently in premature infants. Neutropenia can be seen in up to 8% of all infants admitted to neonatal intensive care. Neutrophilia is even more common, reported in up to 40% of all preterm infants. CONCLUSIONS: Neutrophil counts should be carefully evaluated in premature neonates. Maternal and perinatal history, physical examination, and a limited laboratory assessment is usually adequate for making a diagnosis in most infants

Effect of Cavity Design on the Strength of Direct Posterior Composite Restorations: An Empirical and FEM Analysis

The aim of the present study was to verify the hypothesis that cavity design does not affect the strength of direct composite restorations as do material properties. Finite element modeling (FEM) and empirical testing were done for two cavity designs: a box shape (cube) and a concave shape (U). Two microhybrid composites were used to prepare the samples with the help of split stainless steel moulds. Compressive strength was tested. The results were statistically analyzed. Both FEA and empirical testing were complementary to each other in that the concave shape showed a significantly higher strength than box. Material properties affected the values only when box shape was used. The null hypothesis is thus rejected, and it is concluded that design significantly affects the strength of direct composite restorations

Association between red cell transfusions and necrotizing enterocolitis

OBJECTIVE: Several case reports and retrospective studies have reported a temporal association between red blood cell (RBC) transfusions and necrotizing enterocolitis (NEC). In this article, we review the clinical evidence and biological plausibility of the association between RBC transfusions and NEC. METHODS: A literature search was performed using the databases PubMed, EMBASE, and Scopus, and the electronic archive of abstracts presented at the annual meetings of the Pediatric Academic Societies. RESULTS: Among all cases of NEC, 25 -40% patients were noted to have received an RBC transfusion within a 48 hour period prior to onset of NEC. Compared to infants who developed NEC unrelated to transfusion, neonates with transfusion-associated NEC were born at an earlier gestation, had lower birth weights, and had a delayed onset at 3-5 weeks of postnatal age. CONCLUSIONS: Based on current clinical evidence, transfusion-associated NEC appears to be a plausible clinical entity. However, there is a need for cautious interpretation of data because all the studies that have been conducted until date are retrospective, and therefore, susceptible to bias. A large, prospective, multi-center trial is needed to evaluate the association between RBC transfusion and NEC

Challenges of user-driven R&D: BARC model

This article does not have an abstract

A second ceramic age - a new materials frontier

A second ceramic age started in the mid-twentieth century as a new, exciting materials frontier. Electroceramics with phenomenally wide range of electrical resistivity (spread over 30 orders of magnitude) span insulators, semiconductors, metal-like conductors, ionic conductors, and, recently, superconductors. They also include ferroelectrics, piezoelectrics, pyroelectrics and electro-optics beside ferrites. Advances in electroceramics have been fascinating and rapid, leading to unprecedented rates of industrial growth. Age-old limitations of poor mechanical strength and brittleness of ceramics are being overcome by outstanding toughness and strength achieved in zirconia-based ceramics exploiting the martensitic transformation at the tetragonal-monoclinic phase change. The dimensional changes at this transition which prevented the use of zirconia earlier has now been turned into a mechanism for toughening ceramics to significant levels. Ceramics with near-zero overall thermal expansion coefficient offer new opportunities to science and industry

Multiple Slot Fractal Structured Antenna for Wi-Fi and Radio Altimeter for uncertain Applications

A multiple slot fractal antenna design has been determined communication efficiency and its multi-function activities.  High-speed small communication devices have been required for future smart chip applications, so that researchers have been employed new and creative antenna design. Antennas are key part in communication systems, those are used to improve communication parameters like gain, efficiency, and bandwidth. Consistently, modern antennas design with high bandwidth and gain balancing is very difficult, therefore an adaptive antenna array chip design is required. In this research work a coaxial fed antenna with fractal geometry design has been implemented for Wi-Fi and Radio altimeter application. The fractal geometry has been taken with multiple numbers of slots in the radiating structure for uncertain applications. The coaxial feeding location has been selected based on the good impedance matching condition (50 Ohms). The overall dimension mentioned for antenna are approximately 50X50X1.6 mm on FR4 substrate and performance characteristic analysis is performed with change in substrate material presented in this work. Dual-band resonant frequency is being emitted by the antenna with resonance at 3.1 and 4.3 GHz for FR4 substrate material and change in the resonant bands is obtained with change in substrate. The proposed Antenna is prototyped on Anritsu VNA tool and presented the comparative analysis like VSWR 12%, reflection coefficient 9.4%,3D-Gain 6.2% and surface current 9.3% had been improved

Physiological Mechanisms Relevant to Genetic Improvement of Salinity Tolerance in Crop Plants

Crop species differ widely in their ability to grow and yield under saline condition,, However almost all crop plants belong to the glycophytic category except for a few crop species such as sugar beel, whch has halophytic ancestors by ecological definition , halohytes are tha native flora of saline habitats[1] from a crop improvement perspective the variability for salinity tolerance......................

Potential for Genetic Improvement in Salinity Tolerance in Legumes: Pigeon Pea

Leguminous crops are cultivated throughout the world because of their importance as a protein source in the diets of humans and livestock. Furthcr, many leguminous species are cultivated as pasture, fodder, or green manure plants. Legumes thereby form essential components of cropping systems, primarily because of their inputs of nitrogen fixed from the atmosphere but also for other benefits thcy offer, such as improving the soil physical and chemical environment and breaking disease cycles (I). Among various crop plants tested, however, legumes have generally been found to be more sensitive to soil salinity (2). With the emphasis given to increasing cereal production in recent decades, the cultivation of legume crops has generally been forced to more marginal lands, including those prone to salinity problems. Further, legumes grown on residual soil moisture in the season after thc rains, such as chickpea and lentil, are particularly pronc to salt damage: salts are progressively concentrated in the soil solution and precipitated toward the soil surface as the soil dries out. Thus, legumcs generally face a greater threat of salinity than cereals because of their greater salt sensitivity and an increasing likelihood of being exposed to saline environments. Thcreforc, improvement in the salinity tolerance of legumes is of immediate and increasing concern