26 research outputs found

    Fragmentation channels of relativistic 7^7Be nuclei in peripheral interactions

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    Nuclei of 7^7Li were accelerated at the JINR Nuclotron. After the charge-exchange reaction involving these nuclei at an external target a second 7^7Be beam of energy 1.23A GeV was formed. This beam was used to expose photo-emulsion chambers. The mean free path for inelastic 7^7Be interactions in emulsion λ\lambda=14.0±\pm0.8 cm coincides within the errors with those for 6^6Li and 7^7Li nuclei. More than 10% of the 7^7Be events are associated with the peripheral interactions in which the total charge of the relativistic fragments is equal to the charge of the 7^7Be and in which charged mesons are not produced. An unusual ratio of the isotopes is revealed in the composition of the doubly charged 7^7Be fragments: the number of 3^3He fragments is twice as large as that of 4^4He fragments. In 50% of peripheral interactions, a 7^7Be nucleus decays to two doubly charged fragments. The present paper gives the channels of the 7^7Be fragmentation to charged fragments. In 50% of events, the 7^7Be fragmentation proceeds only to charged fragments involving no emission of neutrons. Of them, the 3^3He+4^4He channel dominates, the 4^4He+d+p and 6^6Li+pchannels constitute 10% each. Two events involving no emission of neutrons are registered in the 3-body 3^3He+t+p and 3^3He+d+d channels. The mean free path for the coherent dissociation of relativistic 7^7Be nuclei to 3^3He+4^4He is 7±\pm1 m. The particular features of the relativistic 7^7Be fragmentation in such peripheral interactions are explained by the 3^3He+4^4He 2-cluster structure of the 7^7Be nucleus.Comment: 10 pages, 3 figures, 3 tables, conference: Conference on Physics of Fundamental Interactions, Moscow, Russia, 5-9 Dec 200

    Monozygotic twins discordant for constitutive BRCA1 promoter methylation, childhood cancer and secondary cancer

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    We describe monozygotic twins discordant for childhood leukemia and secondary thyroid carcinoma. We used bisulfite pyrosequencing to compare the constitutive promoter methylation of BRCA1 and several other tumor suppressor genes in primary fibroblasts. The affected twin displayed an increased BRCA1 methylation (12%), compared with her sister (3%). Subsequent bisulfite plasmid sequencing demonstrated that 13% (6 of 47) BRCA1 alleles were fully methylated in the affected twin, whereas her sister displayed only single CpG errors without functional implications. This between-twin methylation difference was also found in irradiated fibroblasts and untreated saliva cells. The BRCA1 epimutation may have originated by an early somatic event in the affected twin: approximately 25% of her body cells derived from different embryonic cell lineages carry one epigenetically inactivated BRCA1 allele. This epimutation was associated with reduced basal protein levels and a higher induction of BRCA1 after DNA damage. In addition, we performed a genome-wide microarray analysis of both sisters and found several copy number variations, i.e., heterozygous deletion and reduced expression of the RSPO3 gene in the affected twin. This monozygotic twin pair represents an impressive example of epigenetic somatic mosaicism, suggesting a role for constitutive epimutations, maybe along with de novo genetic alterations in recurrent tumor development

    The International Natural Product Sciences Taskforce (INPST) and the power of Twitter networking exemplified through #INPST hashtag analysis

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    Background: The development of digital technologies and the evolution of open innovation approaches have enabled the creation of diverse virtual organizations and enterprises coordinating their activities primarily online. The open innovation platform titled "International Natural Product Sciences Taskforce" (INPST) was established in 2018, to bring together in collaborative environment individuals and organizations interested in natural product scientific research, and to empower their interactions by using digital communication tools. Methods: In this work, we present a general overview of INPST activities and showcase the specific use of Twitter as a powerful networking tool that was used to host a one-week "2021 INPST Twitter Networking Event" (spanning from 31st May 2021 to 6th June 2021) based on the application of the Twitter hashtag #INPST. Results and Conclusion: The use of this hashtag during the networking event period was analyzed with Symplur Signals (https://www.symplur.com/), revealing a total of 6,036 tweets, shared by 686 users, which generated a total of 65,004,773 impressions (views of the respective tweets). This networking event's achieved high visibility and participation rate showcases a convincing example of how this social media platform can be used as a highly effective tool to host virtual Twitter-based international biomedical research events

    AMELIORATIVE EFFECTS OF ARTEMISIA JUDAICA L. EXTRACT AGAINST ALLOXAN-INDUCED BIOCHEMICAL ALTERATIONS IN MALE WISTAR RATS

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    Objective: The current study aims to evaluate the potential of crude leaf extract of Artemisia judaica L. (AJE) in reducing the biochemical abnormalities accompanied to alloxan-induced diabetes in male Wistar rats.Methods: Thirty male albino rats (100-110 g) were divided equally into three groups including control, diabetic and diabetic+AJE. Diabetes was induced by using a single dose of alloxan (120 mg/kg of body weight). Serum biochemical parameters, including insulin, glucose, triglycerides, total cholesterol (TC), high-density lipoprotein cholesterol (HDL), low-density lipoprotein cholesterol (LDL), very low density lipoprotein cholesterol (VLDL), total proteins, albumin, globulin, renal markers (creatinine, urea, uric acid), activities of aspartate transaminase (AST), alanine transaminase (ALT) and gamma-glutamyltransferase (ɤGT) were measured in all groups. Also, values of homeostasis model assessment of insulin resistance (HOMA-IR) and ratios of albumin: globulin (A: G), TC/HDL (risk factor-1), LDL/HDL (risk factor-2) were calculated for each group.Results: Diabetic rats showed reduction in body weight and marked decline in the values of serum insulin, protein profile indices and HDL accompanied with marked elevation in values of glucose, HOMA_IR, triglycerides, TC, LDL, VLDL, TC/HDL, LDL/HDL, renal markers and activities of the estimated enzymes. Supplementation of diabetic rats with AJE, twice daily for 30 days, significantly ameliorated most of the estimated biochemical parameters.Conclusion: The current results demonstrate that AJE possesses a hypoglycemic effect and acts as a protective factor against metabolic abnormalities induced by diabetes mellitus.Â

    Thermal modeling and hydrocarbon generation of the Late Jurassic-Early Cretaceous Chia Gara Formation in Iraqi Kurdistan region, northern Zagros Fold Belt

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    The Late Jurassic-Early Cretaceous Chia Gara Formation is an important oil-source rock in Iraqi Kurdistan region. Chia Gara source rock is characterised by high organic matter and sulphur content with Type II_S kerogen. 1D basin models were integrated with geological information and geochemical data from Chia Gara Fm at four well locations in Kurdistan region, northern Iraq. The models of the burial/thermal history indicate that Chia Gara Fm is presently in the peak-oil generation window and some oil cracked to gas during Late Eocene to Late Miocene time. Onset of oil-generation began during the Middle Paleocene- Early Oligocene (60–30 Ma). Oil was generated during the Late Eocene to Late Miocene (48–9 Ma). The models also suggest that the oil was expelled from Chia Gara source rock during the Late Eocene to Late Miocene (37–9 Ma), with a transformation ratio more than 50%. The high transformation ratio of more than 80% in two wells suggests that the generated oil was cracked to gas during the end of Middle Miocene time and continued to present day. The basin modeling results further suggest that Chia Gara Formation acts as a prolific petroleum-source rock and significant of oil and limited of gas have been generated and expelled to any nearby prospect reservoir rocks in the Kurdistan region. Keywords: Chia Gara Formation, Basin modeling, Petroleum generation history, Zagros Fold Belt Basin, North Ira
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