STRUCTURAL AND OPTICAL PROPERTIES OF ZnS NANOPARTICLES SYNTHESIZED BY MICROWAVE IRRADIATION METHOD

ZnS nanoparticles were synthesized by Microwave assisted irradiation method. The obtained ZnS nanoparticles were characterized by XRD, SEM and UV-Vis spectroscopy. XRD characterization of the samples were taken which verify the crystalline form of the samples and also the average size of the nanocrystallites were measured by DebyeScherrer formula as per the XRD spectrum, which was found to be around 6 nm. The surface morphology of the ZnS nanocrystallites was taken by Scanning Electron Microscopy. The UV-Visible absorption spectra of the nanocrystallites were taken and the optical bandgap of the ZnS nanocrystals were found to be 3.76 eV

Hypervalent iodine mediated synthesis of 3-substituted-s- triazolo[3,4-a]phthalazines

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Hypervalent iodine mediated synthesis of the heterocyclyl-1,3,4-oxadiazoles

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Design and Build a Compact Raman Sensor for Identification of Chemical Composition

A compact remote Raman sensor system was developed at NASA Langley Research Center. This sensor is an improvement over the previously reported system, which consisted of a 532 nm pulsed laser, a 4-inch telescope, a spectrograph, and an intensified charge-coupled devices (CCD) camera. One of the attractive features of the previous system was its portability, thereby making it suitable for applications such as planetary surface explorations, homeland security and defense applications where a compact portable instrument is important. The new system was made more compact by replacing bulky components with smaller and lighter components. The new compact system uses a smaller spectrograph measuring 9 x 4 x 4 in. and a smaller intensified CCD camera measuring 5 in. long and 2 in. in diameter. The previous system was used to obtain the Raman spectra of several materials that are important to defense and security applications. Furthermore, the new compact Raman sensor system is used to obtain the Raman spectra of a diverse set of materials to demonstrate the sensor system's potential use in the identification of unknown materials

Remote Raman Sensor System for Testing of Rocks and Minerals

Recent and future explorations of Mars and lunar surfaces through rovers and landers have spawned great interest in developing an instrument that can perform in-situ analysis of minerals on planetary surfaces. Several research groups have anticipated that for such analysis, Raman spectroscopy is the best suited technique because it can unambiguously provide the composition and structure of a material. A remote pulsed Raman spectroscopy system for analyzing minerals was demonstrated at NASA Langley Research Center in collaboration with the University of Hawaii. This system utilizes a 532 nm pulsed laser as an excitation wavelength, and a telescope with a 4-inch aperture for collecting backscattered radiation. A spectrograph equipped with a super notch filter for attenuating Rayleigh scattering is used to analyze the scattered signal. To form the Raman spectrum, the spectrograph utilizes a holographic transmission grating that simultaneously disperses two spectral tracks on the detector for increased spectral range. The spectrum is recorded on an intensified charge-coupled device (ICCD) camera system, which provides high gain to allow detection of inherently weak Stokes lines. To evaluate the performance of the system, Raman standards such as calcite and naphthalene are analyzed. Several sets of rock and gemstone samples obtained from Ward s Natural Science are tested using the Raman spectroscopy system. In addition, Raman spectra of combustible substances such acetone and isopropanol are also obtained. Results obtained from those samples and combustible substances are presented

High anorectal malformation in a five-month-old boy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Anorectal malformation, one of the most common congenital defects, may present with a wide spectrum of defects. Almost all male patients present within first few days of life.</p> <p>Case presentation</p> <p>A five-month-old baby boy of Indian origin and nationality presented with anal atresia and associated rectourethral prostatic fistula. The anatomy of the malformation and our patient's good condition permitted a primary definitive repair of the anomaly. A brief review of the relevant literature is included.</p> <p>Conclusion</p> <p>Delayed presentation of a patient with high anorectal malformation is rare. The appropriate treatment can be rewarding.</p

Sarcocystis cymruensis: discovery in Western Hemisphere in the Brown rat (Rattus norvegicus) from Grenada, West Indies: redescription, molecular characterization, and transmission to IFN-γ gene knockout mice via sporocysts from experimentally infected domestic cat (Felis catus)

Rodents are intermediate hosts for many species of Sarcocystis. Little is known of Sarcocystis cymruensis that uses the Brown rat (Rattus norvegicus) as intermediate hosts and the domestic cat (Felis catus) as experimental definitive host. Here, we identified and described Sarcocystis cymruensis in naturally infected R. norvegicus from Grenada, West Indies. Rats (n = 167) were trapped in various locations in two parishes (St. George and St. David). Microscopic, thin (\u3c 1 μm) walled, slender sarcocysts were found in 11 of 156 (7.0%) rats skeletal muscles by squash examination. A laboratory-raised cat fed naturally infected rat tissues excreted sporocysts that were infectious for interferon gamma gene knockout (KO) mice, but not to Swiss Webster outbred albino mice. All inoculated mice remained asymptomatic, and microscopic S. cymruensis-like sarcocysts were found in the muscles of KO mice euthanized on day 70, 116, and 189 post inoculation (p.i.). Sarcocysts from infected KO mice were infective for cats at day 116 but not at 70 days p.i. By transmission electron microscopy, the sarcocyst wall was Btype 1a.^ Detailed morphological description of the cyst wall, metrocytes, and bradyzoites is given for the first time. Additionally, molecular data on S. cymruensis are presented also for the first time. Molecular characterization of sarcocysts 18S rDNA and 28S rDNA, ITS-1, and cox1 loci showed the highest similarity with S. rodentifelis and S. muris. In conclusion, the present study described the natural infection of S. cymruensis in Brown rat for the first time in a Caribbean country and provided its molecular characteristics

Ethylene induced stay-green gene expression regulates drought stress in wheat

Stay-green is an integrated drought adaptation trait characterized by a green leaf phenotype during grain filling under terminal drought. Ethylene is the key hormone for regulating the leaf senescence pathway under natural and stress conditions. The present study was conducted to assess the associative function of ethylene in regulating chlorophyll degrading enzymes viz., chlorophyllase (TaCHLase) and pheophorbide a oxygenase (TaPaO) in wheat (Triticum aestivum L.) under drought stress. Three wheat genotypes (HW 4059, HW 4022 and HW 2078) differing in drought tolerance efficiency were subjected to drought stress for ten days at the reproductive stage. A decline in stay-green traits was found in susceptible genotypes (HW 4059) with yield losses compared to tolerant ones (HW 4022 and HW 2078). The expression level of TaCHLase1 and TaPaO was higher in susceptible genotypes than tolerant ones under drought/osmotic stress. Ethylene upregulated, while ethylene inhibitors downregulated the gene expression. In this study, a novel gene annotated as TaCHLase1 was cloned. The complete cDNA sequence of TaCHLase1 is composed of 1054 bp nucleotides containing an open reading frame of 960 bp encoding 319 amino acids. The encoded protein contained conserved residues such as lipase motif GXSXGG at position 143-148 and putative active site Ser145. Sequence alignment showed TaCHLase1 shares a higher degree of identity with other species. The result suggested that ethylene upregulates the expression of TaCHLase1 gene, inducing chlorophyll degradation. The study further helps in understanding the mechanism of stay-green trait-induced drought tolerance mechanism in wheat

Duplication cyst of pyloroduodenal canal: a rare cause of neonatal gastric outlet obstruction: a case report

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