106 research outputs found

    Spectral function at high missing energies and momenta

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    The nuclear spectral function at high missing energies and momenta has been determined from a self-consistent calculation of the Green's function in nuclear matter using realistic nucleon-nucleon interactions. The results are compared with recent experimental data derived from (e,e′pe,e'p) reactions on 12C^{12}C. A rather good agreement is obtained if the Green's functions are calculated in a non-perturbative way.Comment: 10 pages, 3 figure

    Effects of Ketosis and Hypocalcemia on The Biochemical Parameters and Subsequent Postpartum Reproductive Performance in Buffaloes

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    Water buffaloes (Bubalus bubalis) are mainly distributed in tropical and subtropical countries that include the Indian sub-continent and some Mediterranean countries such as Egypt. The transition period is the most stressful period for buffaloes, and it is considered as a turning point in the productive cycle from one lactation to the next and includes different metabolic, physiological, and nutritional changes. Metabolic disorders are common causes of lower productivity in buffaloes. Of these metabolic disorders, ketosis and hypocalcemia are most prevalent. This study aimed to study the ketosis- and hypocalcemia-related biochemical changes during the transition period and their impacts on the postpartum reproductive fertility in Buffaloes. Out of 120 total number of examined buffaloes, 40 buffaloes were used in this study; control group (n=10), hypocalcemia-affected (n=15), and ketosis-affected group (n=15). All buffaloes were subjected to thorough clinical and gynecological examination. Both urine and blood samples were collected from all groups. The amounts of ketone bodies were detected in urine. Biochemical parameters were evaluated including concentrations of glucose, triglycerides, cholesterol, non-esterified fatty acids (NEFA), calcium, phosphorus, sodium, potassium, albumin, total protein, urea and progesterone hormone (P4) in blood the following time-points (2-weeks prepartum, 1-week prepartum, partum, 1-week postpartum, and 2-weeks postpartum). Both hypocalcemia- and ketosis affected buffaloes had lower glucose, phosphorus, sodium and albumin and higher NEFA than control group. Hypocalcemia-affected buffaloes showed lower calcium and higher total protein than control group, while, ketosis-affected buffaloes showed lower cholesterol and total protein than control group. Moreover, metabolic disorders negatively affected the reproductive performance. Both ketosis and hypocalcemia significantly prolonged the duration to first estrus, increased both the number of days-open and the number of services per conceptio

    Small-Molecule Inhibitors of Dengue-Virus Entry

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    Flavivirus envelope protein (E) mediates membrane fusion and viral entry from endosomes. A low-pH induced, dimer-to-trimer rearrangement and reconfiguration of the membrane-proximal “stem" of the E ectodomain draw together the viral and cellular membranes. We found stem-derived peptides from dengue virus (DV) bind stem-less E trimer and mimic the stem-reconfiguration step in the fusion pathway. We adapted this experiment as a high-throughput screen for small molecules that block peptide binding and thus may inhibit viral entry. A compound identified in this screen, 1662G07, and a number of its analogs reversibly inhibit DV infectivity. They do so by binding the prefusion, dimeric E on the virion surface, before adsorption to a cell. They also block viral fusion with liposomes. Structure-activity relationship studies have led to analogs with submicromolar IC90s against DV2, and certain analogs are active against DV serotypes 1,2, and 4. The compounds do not inhibit the closely related Kunjin virus. We propose that they bind in a previously identified, E-protein pocket, exposed on the virion surface and although this pocket is closed in the postfusion trimer, its mouth is fully accessible. Examination of the E-trimer coordinates (PDB 1OK8) shows that conformational fluctuations around the hinge could open the pocket without dissociating the trimer or otherwise generating molecular collisions. We propose that compounds such as 1662G07 trap the sE trimer in a “pocket-open" state, which has lost affinity for the stem peptide and cannot support the final “zipping up" of the stem

    Michael Reactions of Arylidenesulfonylacetonitriles. A New Route to Polyfunctional Benzo[a]quinolizines

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    Abstract: Arylidenesulfonylacetonitriles react in acetonitrile with 1-methylisoquinoline and isoquinolin-1-yl-acetonitrile in the presence of piperidine to give benzo[a]quinolizines 6,9 and 7,10, respectively. The structures of the products were established on the basis of elemental and spectral analyses and their chemical reactivity

    Chemistry of the Enaminone of 1-Acetylnaphthalene under Microwave Irradiation Using Chitosan as a Green Catalyst

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    Enaminone 1 was reacted with hydrazonoyl halides 2a-d to yield 3,4-disubstituted pyrazoles 6a-d. Coupling with arenediazonium chlorides afforded the 2-(arylhydrazono)-3-(1-naphthalenyl)-3-oxopropionaldehydes 13a-c. Compounds 13 could be utilized for the synthesis of a variety of arylpyrazoles, arylazolopyrimidines, and pyridazinones via reaction with hydrazines, aminoazoles, and active methylene derivatives, respectively. A comparative study of aforementioned reactions was carried out with chitosan as a basic ecofriendly catalyst under conventional heating as well as under pressurized microwave irradiation conditions

    2-(4-Chloro­phenyl)-1,3-di­cyano-6,7-di­hydro-4-imino-9,10-di­methoxy­benzo­[a]­quinolizine–water (2/5)

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    Crystals of the title compound, C23H17ClN4O2 x 2.5H2O, contain channels filled with highly disordered water molecules. The best structure refinement was obtained by removing the solvent contribution from the intensity data and refining against a solvent-free model. The central six-membered ring of the quinolizine molecule has a slightly distorted screw-boat conformation
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