Using a deformed crystal for bending a sub-GeV positron beam

Abstract We analyze the scattering of 480 MeV positrons in bent crystal lattices carried out at the Beam Test Facility of the INFN – Laboratori Nazionali di Frascati. We observe experimentally that some particles follow the bending of the crystal lattice, presumably being guided by channeling phenomenon, and are deflected through the angles of about 10 mrad over length of 1 mm of silicon. This technique may lead to the use of channeling effect for steering of particle beams at the energies under 1 GeV, aimed at the production of ultrastable beams of low emittance for medical and biological applications

Steering a multi-MeV positron beam with a curved crystal

We observe positron bending by a crystal lattice, presumably being guided by a channeling phenomenon, deflecting the beam by about 10 milliradian over a length of 1 mm of silicon. This technique may lead to the use of the channeling effect for steering particle beams at energies below 1 GeV, for the purpose of producing beams of low emittance with enhanced stability for medical and biological applications

Heliospheric Response to Different Possible Interstellar Environments

At present, the heliosphere is embedded in a warm, low-density interstellar cloud that belongs to a cloud system flowing through the local standard of rest with a velocity near ~18 km s-1. The velocity structure of the nearest interstellar material (ISM), combined with theoretical models of the local interstellar cloud (LIC), suggest that the Sun passes through cloudlets on timescales of ≤103-104 yr, so the heliosphere has been, and will be, exposed to different interstellar environments over time. By means of a multifluid model that treats plasma and neutral hydrogen self-consistently, the interaction of the solar wind with a variety of partially ionized ISM is investigated, with the focus on low-density cloudlets such as are currently near the Sun. Under the assumption that the basic solar wind parameters remain/were as they are today, a range of ISM parameters (from cold neutral to hot ionized, with various densities and velocities) is considered. In response to different interstellar boundary conditions, the heliospheric size and structure change, as does the abundance of interstellar and secondary neutrals in the inner heliosphere, and the cosmic-ray level in the vicinity of Earth. Some empirical relations between interstellar parameters and heliospheric boundary locations, as well as neutral densities, are extracted from the models

Thermal- and Oxidative Stress Causes Enhanced Release of NKG2D Ligand-Bearing Immunosuppressive Exosomes in Leukemia/Lymphoma T and B Cells

Immune evasion from NK surveillance related to inadequate NK-cell function has been suggested as an explanation of the high incidence of relapse and fatal outcome of many blood malignancies. In this report we have used Jurkat and Raji cell lines as a model for studies of the NKG2D receptor-ligand system in T-and B cell leukemia/lymphoma. Using real-time quantitative RT-PCR and immunoflow cytometry we show that Jurkat and Raji cells constitutively express mRNA and protein for the stress-inducible NKG2D ligands MICA/B and ULBP1 and 2, and up-regulate the expression in a cell-line specific and stress-specific manner. Furthermore, we revealed by electron microscopy, immunoflow cytometry and western blot that these ligands were expressed and secreted on exosomes, nanometer-sized microvesicles of endosomal origin. Acting as a decoy, the NKG2D ligand-bearing exosomes downregulate the in vitro NKG2D receptor-mediated cytotoxicity and thus impair NK-cell function. Interestingly, thermal and oxidative stress enhanced the exosome secretion generating more soluble NKG2D ligands that aggravated the impairment of the cytotoxic response. Taken together, our results might partly explain the clinically observed NK-cell dysfunction in patients suffering from leukemia/lymphoma. The adverse effect of thermal and oxidative stress, enhancing the release of immunosuppressive exosomes, should be considered when cytostatic and hyperthermal anti-cancer therapies are designed

Erratum to: "Double volume reflection of a proton beam by a sequence of two bent crystals" [Phys. Lett. B 658 (2008) 109]

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Comment on the letter of the Society of Vertebrate Paleontology (SVP) dated April 21, 2020 regarding 'Fossils from conflict zones and reproducibility of fossil‑based scientific data': Myanmar amber

Recently, the Society of Vertebrate Paleontology (SVP) has sent around a letter, dated 21st April, 2020 to more than 300 palaeontological journals, signed by the President, Vice President and a former President of the society (Rayfield et al. 2020). The signatories of this letter request significant changes to the common practices in palaeontology. With our present, multi-authored comment, we aim to argue why these suggestions will not lead to improvement of both practice and ethics of palaeontological research but, conversely, hamper its further development. Although we disagree with most contents of the SVP letter, we appreciate this initiative to discuss scientific practices and the underlying ethics. Here, we consider different aspects of the suggestions by Rayfield et al. (2020) in which we see weaknesses and dangers. It is our intent to compile views from many different fields of palaeontology, as our discipline is (and should remain) pluralistic. This contribution deals with the aspects concerning Myanmar amber. Reference is made to Haug et al. (2020a) for another comment on aspects concerning amateur palaeontologists/citizen scientists/private collectors

Comment on the letter of the Society of Vertebrate Paleontology (SVP) dated April 21, 2020 regarding “Fossils from conflict zones and reproducibility of fossil‑based scientific data”: Myanmar amber

Non peer reviewe

The Influence of Political Connection and Institutions to the Performance and Bank Loans of Private Listed Companies

我国有着不同于西方发达国家的制度背景和政治制度，政府对市场的管制力度较大，上市公司的高管具有一定的政治背景，其中国有企业本身大股东的政府背景性质，其政治关联很可能是与生俱来的，而民营企业政治关联的形成则具有主动性。改革开放以来，民营经济不断发展壮大，己成为我国经济增长的主要推动力量，因此，研究政治关联对民营公司的影响这一问题在中国更具有现实启发意义。 本文以民营上市公司的高级管理人员是否是前任或现任的政府官员、人大代表或政协委员来衡量公司是否具有政治关联，选取2004年—2008年中国沪深两市所有A股民营上市公司为样本，实证研究了政治关联与制度环境对民营上市公司经营绩效和银行贷款的影响。研究...Chinese current institution and political system are different from the Western developed countries. Under this system, many executives of private listed companies are relevant to politics. Therefore the study of political influence of private companies related to this issue in China is more realistic instructive. This paper focuses on whether the company has the political connection, which measu...学位：管理学硕士院系专业：管理学院财务学系_财务学学号：1762007115174

Ротавирусная инфекция у детей — нерешенная проблема. Обзор рекомендаций по вакцинопрофилактике

These clinical guidelines were developed by the professional association of pediatric specialists «Union of Pediatricians of Russia» and approved by the Association’s Executive Committee at the Congress of Pediatricians of Russia «Actual Problems of Pediatrics». Clinical guidelines are devoted to the problem of rotavirus infection, the relevance of which is determined by the high prevalence level and significant contribution of infectious diarrhea to the mortality pattern of children in the first 5 years of life. We present epidemiological data and detailed information on the infectious agent and pathogenesis of rotavirus infection progression. A detailed picture of clinical manifestations as well as extraintestinal complications is presented. The approach to specific prophylaxis has been reasoned. Practical recommendations for immunization as well as various regimens for administering the vaccine, depending on the age and condition of the patient, are given.Данные клинические рекомендации разработаны профессиональной ассоциацией детских специалистов «Союз педиатров России» и утверждены Исполкомом ассоциации на Съезде педиатров России «Актуальные проблемы педиатрии». Клинические рекомендации посвящены проблеме ротавирусной инфекции, актуальность которой определяется высоким уровнем распространенности и значительным вкладом инфекционной диареи в структуру смертности детей первых 5 лет жизни. Приводятся эпидемиологические данные, подробно описаны особенности возбудителя, патогенез развития ротавирусной инфекции. Представлена развернутая картина клинических проявлений, а также внекишечных осложнений. Обоснована тактика специфической профилактики. Даны практические рекомендации по проведению иммунизации, а также различные схемы введения вакцины в зависимости от возраста и состояния пациента