70 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

    Properties of asymmetric nuclear matter in different approaches

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    Properties of asymmetric nuclear matter are derived from various many-body approaches. This includes phenomenological ones like the Skyrme Hartree-Fock and relativistic mean field approaches, which are adjusted to fit properties of nuclei, as well as more microscopic attempts like the Brueckner-Hartree-Fock approximation, a self-consistent Greens function method and the so-called VlowkV_{lowk} approach, which are based on realistic nucleon-nucleon interactions which reproduce the nucleon-nucleon phase shifts. These microscopic approaches are supplemented by a density-dependent contact interaction to achieve the empirical saturation property of symmetric nuclear matter. The predictions of all these approaches are discussed for nuclear matter at high densities in β\beta-equilibrium. Special attention is paid to behavior of the isovector component of the effective mass in neutron-rich matter.Comment: 16 pages, 7 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

    Camel milk or silymarin could improve the negative effects that experimentally produced by aflatoxin B1 on rat’s male reproductive system

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    Abstract Background Camel milk and silymarin have many different beneficial effects on several animal species. Meanwhile, Aflatoxins are mycotoxins with extraordinary potency that pose major health risks to several animal species. Additionally, it has been documented that aflatoxins harm the reproductive systems of a variety of domestic animals. The present design aimed to investigate the impact of aflatoxin B1 (AFB1) on rat body weight and reproductive organs and the ameliorative effects of camel milk and silymarin through measured serum testosterone, testes pathology, and gene expression of tumor necrosis factor (TNF-α), luteinizing hormone receptor (LHR), and steroidogenic acute regulatory protein (StAR) in the testes. A total of sixty mature male Wister white rats, each weighing an average of 83.67 ± 0.21 g, were used. There were six groups created from the rats. Each division had ten rats. The groups were the control (without any treatment), CM (1 ml of camel milk/kg body weight orally), S (20 mg silymarin/kg b. wt. suspension, orally), A (1.4 mg aflatoxin/kg diet), ACM (aflatoxin plus camel milk), and AS (aflatoxin plus silymarin). Results The results indicated the positive effects of camel milk and silymarin on growth, reproductive organs, and gene expression of TNF-α, LHR, and StAR with normal testicular architecture. Also, the negative effect of AFB1 on the rat’s body weight and reproductive organs, as indicated by low body weight and testosterone concentration, was confirmed by the results of histopathology and gene expression. However, these negative effects were ameliorated by the ingestion of camel milk and silymarin. Conclusion In conclusion, camel milk and silymarin could mitigate the negative effect of AFB1 on rat body weight and reproductive organs
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