23 research outputs found

    Photoproduction of Long-Lived Holes and Electronic Processes in Intrinsic Electric Fields Seen through Photoinduced Absorption and Dichroism in Ca_3Ga_{2-x}Mn_xGe_3O_{12} Garnets

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    Long-lived photoinduced absorption and dichroism in the Ca_3Ga_{2-x}Mn_xGe_3O_{12} garnets with x < 0.06 were examined versus temperature and pumping intensity. Unusual features of the kinetics of photoinduced phenomena are indicative of the underlying electronic processes. The comparison with the case of Ca_3Mn_2Ge_3O_{12}, explored earlier by the authors, permits one to finally establish the main common mechanisms of photoinduced absorption and dichroism caused by random electric fields of photoproduced charges (hole polarons). The rate of their diffusion and relaxation through recombination is strongly influenced by the same fields, whose large statistical straggling is responsible for a broad continuous set of relaxation components (observed in the relaxation time range from 1 to about 1000 min). For Ca_3Ga_{2-x}Mn_xGe_3O_{12}, the time and temperature dependences of photoinduced absorption and dichroism bear a strong imprint of structure imperfection increasing with x.Comment: 20 pages, 10 figure

    arch^{arch}PbMoO4 scintillating bolometer as detector to searches for the neutrinoless double beta decay of 100^{100}Mo

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    The archPbMoO4 scintillating crystal has been produced from archaeological lead for the first time. The advanced technique for deep purification of lead against chemical impurities was used resulting in 99.9995% purity level of final material. The archPbMoO4 crystal was characterized by means of cryogenics bolometric measurements and demonstrates excellent performances as a scintillating bolometer. The energy resolution (0.3% at 1462 keV of 40K), the high light yield (5.2 keV/MeV for γs, and 1.2 keV/MeV for α particles) and the highly efficient particle identification achieved with this detector, representing the high quality of the crystal. As a final proof for the feasibility of the archPbMoO4 crystal as a promising detector to search for the neutrinoless double β-decay of 100Mo, the crystal should be produced using the LTG Czochralski technique to prevent the possible contamination during the crystal growth and to increase the production yield

    Discovery of the 151^{151}Eu α\alpha decay

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    We report on the first compelling observation of α\alpha decay of 151^{151}Eu to the ground state of 147^{147}Pm. The measurement was performed using a 6.15 g Li6_6Eu(BO3_3)3_3 crystal operated as a scintillating bolometer. The Q-value and half-life measured are: Q = 1948.9±6.9(stat.)±5.1(syst.)\pm 6.9(stat.) \pm 5.1(syst.) keV, and T1/2=(4.62±0.95(stat.)±0.68(syst.))×1018_{1/2}=\left( 4.62\pm0.95(stat.)\pm0.68(syst.)\right) \times 10^{18} y . The half-life prediction of nuclear theory using the Coulomb and proximity potential model are in good agreement with this experimental result

    Ethics of HIV cure research: an unfinished agenda

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    Background: The pursuit of a cure for HIV is a high priority for researchers, funding agencies, governments and people living with HIV (PLWH). To date, over 250 biomedical studies worldwide are or have been related to discovering a safe, effective, and scalable HIV cure, most of which are early translational research and experimental medicine. As HIV cure research increases, it is critical to identify and address the ethical challenges posed by this research. Methods: We conducted a scoping review of the growing HIV cure research ethics literature, focusing on articles published in English peer-reviewed journals from 2013 to 2021. We extracted and summarized key developments in the ethics of HIV cure research. Twelve community advocates actively engaged in HIV cure research provided input on this summary and suggested areas warranting further ethical inquiry and foresight via email exchange and video conferencing. Discussion: Despite substantial scholarship related to the ethics of HIV cure research, additional attention should focus on emerging issues in six categories of ethical issues: (1) social value (ongoing and emerging biomedical research and scalability considerations); (2) scientific validity (study design issues, such as the use of analytical treatment interruptions and placebos); (3) fair selection of participants (equity and justice considerations); (4) favorable benefit/risk balance (early phase research, benefit-risk balance, risk perception, psychological risks, and pediatric research); (5) informed consent (attention to language, decision-making, informed consent processes and scientific uncertainty); and (6) respect for enrolled participants and community (perspectives of people living with HIV and affected communities and representation). Conclusion: HIV cure research ethics has an unfinished agenda. Scientific research and bioethics should work in tandem to advance ethical HIV cure research. Because the science of HIV cure research will continue to rapidly advance, ethical considerations of the major themes we identified will need to be revisited and refined over time

    The ethics of digital well-being: a multidisciplinary perspective

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    This chapter serves as an introduction to the edited collection of the same name, which includes chapters that explore digital well-being from a range of disciplinary perspectives, including philosophy, psychology, economics, health care, and education. The purpose of this introductory chapter is to provide a short primer on the different disciplinary approaches to the study of well-being. To supplement this primer, we also invited key experts from several disciplines—philosophy, psychology, public policy, and health care—to share their thoughts on what they believe are the most important open questions and ethical issues for the multi-disciplinary study of digital well-being. We also introduce and discuss several themes that we believe will be fundamental to the ongoing study of digital well-being: digital gratitude, automated interventions, and sustainable co-well-being

    Development of Growth Technologies for the Photonic Single Crystals by the Czochralski Method at Institute for Single Crystals, NAS of Ukraine

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    The present paper briefly overviews the application of the Czochralski method for growth of a set of oxide crystals for photonics, as well as the design of equipment at the Institute for Single Crystals, NAS of Ukraine. The examples of crystal growth and their characterization are described. The simultaneous Q-switched lasing and self-Raman frequency conversion were demonstrated in Nd-doped PbWO4PbWO_4 and PbMoO4PbMoO_4 crystals grown by the Czochralski method. The slope lasing efficiency obtained for a PbMoO4:Nd3+PbMoO_4:Nd^{3+} laser is the best result for all the crystals with the scheelite-type structure. A detection unit with high scintillation characteristics based on a large volume (V ≈ 350 cm^3) CdWO4CdWO_4 crystal was produced. Crystal growth procedures and properties of new double tungstate and vanadate crystals are presented, too

    Luminescence of PbWO4O_{4} single crystals doped with fluorine

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    Tumour necrosis factor (TNF)-alpha-converting enzyme (TACE) is a metalloproteinase-disintegrin that releases soluble TNF-alpha from cells by cleaving within the extracellular domain of membrane-bound pro-TNF-alpha. It was proposed that TNF-alpha is involved in the pathogenesis of psoriasis, and it is therefore suggested that TACE has important roles in psoriasis. However, it is unclear whether TACE is expressed in psoriatic tissue.To clarify whether TACE is expressed in psoriatic lesions and whether expression levels of TACE mRNA are increased in lesional compared with nonlesional psoriatic skin.Skin biopsies were obtained from patients with psoriasis. We examined the expression of TACE in psoriatic tissues using a novel real-time quantitative reverse transcriptase-polymerase chain reaction method and immunohistochemical analysis.There was a significant rise in the level of TACE mRNA expression in lesional psoriatic skin compared with nonlesional skin in all patients. There was a statistically significant rise in the level of TACE mRNA expression in lesional psoriatic skin compared with nonlesional skin (mean +/- SD TACE/glyceraldehyde-3-phosphate dehydrogenase ratio 0.031 +/- 0.012 vs. 0.009 +/- 0.002, P < 0.05). In lesional psoriatic skin, immunostaining with anti-TACE antibody was present throughout all layers of the epidermis. TACE immunostaining was found in the cytoplasm of keratinocytes. There was staining associated with blood vessels in the papillary dermis and perivascular inflammatory cells. In particular, mast cells showed strong staining. They contained numerous granules that were stained for TACE in the cytoplasm.The findings of the present study suggest that elevation of TACE mRNA in psoriatic lesions is due to many cells, particularly mast cells, that function in lesional psoriatic skin as an important source of TNF-alpha and other cytokines
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