441 research outputs found
Measurement of Trace I-129 Concentrations in CsI Powder and Organic Liquid Scintillator with Accelerator Mass Spectrometry
Levels of trace radiopurity in active detector materials is a subject of
major concern in low-background experiments. Procedures were devised to measure
trace concentrations of I-129 in the inorganic salt CsI as well as in organic
liquid scintillator with Accelerator Mass Spectrometry (AMS) which leads to
improvement in sensitivities by several orders of magnitude over other methods.
No evidence of their existence in these materials were observed. Limits of < 6
X 10^{-13} g/g and < 2.6 X 10^{-17} g/g on the contaminations of I-129 in CsI
and liquid scintillator, respectively, were derived.These are the first results
in a research program whose goals are to develop techniques to measure trace
radioactivity in detector materials by AMS.Comment: Proceedings of 10th International Conference on Accelerator Mass
Spectrometr
Measurement of Ultra-Low Potassium Contaminations with Accelerator Mass Spectrometry
Levels of trace radiopurity in active detector materials is a subject of
major concern in low-background experiments. Among the radio-isotopes, \k40
is one of the most abundant and yet whose signatures are difficult to reject.
Procedures were devised to measure trace potassium concentrations in the
inorganic salt CsI as well as in organic liquid scintillator (LS) with
Accelerator Mass Spectrometry (AMS), giving, respectively, the
\k40-contamination levels of and g/g.
Measurement flexibilities and sensitivities are improved over conventional
methods. The projected limiting sensitivities if no excess of potassium signals
had been observed over background are g/g and g/g for the CsI and LS, respectively. Studies of the LS samples
indicate that the radioactive contaminations come mainly in the dye solutes,
while the base solvents are orders of magnitude cleaner. The work demonstrate
the possibilities of measuring naturally-occurring isotopes with the AMS
techniques.Comment: 18 pages, 4 figures, 3 table
Deficiency of Th17 cells in hyper IgE syndrome due to mutations in STAT3
Hyperâimmunoglobulin E syndrome (HIES) is a primary immune deficiency characterized by abnormal and devastating susceptibility to a narrow spectrum of infections, most commonly Staphylococcus aureus and Candida albicans. Recent investigations have identified mutations in STAT3 in the majority of HIES patients studied. Despite the identification of the genetic cause of HIES, the mechanisms underlying the pathological features of this disease remain to be elucidated. Here, we demonstrate a failure of CD4+ T cells harboring heterozygous STAT3 mutations to generate interleukin 17âsecreting (i.e., T helper [Th]17) cells in vivo and in vitro due to a failure to express sufficient levels of the Th17-specific transcriptional regulator retinoid-related orphan receptor Îłt. Because Th17 cells are enriched for cells with specificities against fungal antigens, our results may explain the pattern of infection susceptibility characteristic of patients with HIES. Furthermore, they underscore the importance of Th17 responses in normal host defense against the common pathogens S. aureus and C. albicans
ĐĐœĐŸĐłĐŸŃĐ”ĐœŃŃĐŸĐČĐŸĐ” ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžĐ” ŃŃŃĐ”ĐșŃĐžĐČĐœĐŸŃŃĐž ĐœĐ”ĐŸĐ°ĐŽŃŃĐČĐ°ĐœŃĐœĐŸĐč ŃĐ”ŃапОО ĐĄĐĐ ĐĐ„/бДĐČĐ°ŃОзŃĐŒĐ°Đ± Ń ĐœĐ”ĐŸĐżĐ”ŃабДлŃĐœŃŃ Đ±ĐŸĐ»ŃĐœŃŃ Ń ĐŒĐ”ŃĐ°ŃŃĐ°Đ·Đ°ĐŒĐž ĐșĐŸĐ»ĐŸŃĐ”ĐșŃĐ°Đ»ŃĐœĐŸĐłĐŸ ŃĐ°ĐșĐ° ĐČ ĐżĐ”ŃĐ”ĐœĐž
ĐŃĐŸĐ°ĐœĐ°Đ»ĐžĐ·ĐžŃĐŸĐČĐ°ĐœŃ ŃДзŃĐ»ŃŃĐ°ŃŃ ĐŒĐœĐŸĐłĐŸŃĐ”ĐœŃŃĐŸĐČĐŸĐłĐŸ ĐžŃŃĐ»Đ”ĐŽĐŸĐČĐ°ĐœĐžŃ
II ŃĐ°Đ·Ń, ĐČ ĐșĐŸŃĐŸŃĐŸĐŒ ĐżĐŸĐșĐ°Đ·Đ°ĐœĐ° ŃŃŃĐ”ĐșŃĐžĐČĐœĐŸŃŃŃ Đž Đ±Đ”Đ·ĐŸĐżĐ°ŃĐœĐŸŃŃŃ ĐșĐŸĐŒĐ±ĐžĐœĐ°ŃОО
ŃĐ”Đ¶ĐžĐŒĐ° CAPOX Ń Đ±Đ”ĐČĐ°ŃОзŃĐŒĐ°Đ±ĐŸĐŒ ĐżŃĐž ĐœĐ”ĐŸĐ°ĐŽŃŃĐČĐ°ĐœŃĐœĐŸĐč ŃĐ”ŃапОО ĐœĐ” ĐżĐŸĐŽĐ»Đ”Đ¶Đ°ŃĐžŃ
Ń
ĐžŃŃŃгОŃĐ”ŃĐșĐŸĐŒŃ Đ»Đ”ŃĐ”ĐœĐžŃ ĐżĐ°ŃĐžĐ”ĐœŃĐŸĐČ Ń ĐŒĐ”ŃĐ°ŃŃĐ°Đ·Đ°ĐŒĐž ĐșĐŸĐ»ĐŸŃĐ”ĐșŃĐ°Đ»ŃĐœĐŸĐłĐŸ ŃĐ°ĐșĐ° ĐČ ĐżĐ”ŃĐ”ĐœĐž: ŃДзДĐșŃабДлŃĐœĐŸŃŃŃ ĐżĐŸŃĐ»Đ”ĐŽĐœĐžŃ
бŃла ĐŽĐŸŃŃĐžĐłĐœŃŃĐ° ĐČ 44%
ŃĐ»ŃŃĐ°Đ”ĐČ, 12-ĐŒĐ”ŃŃŃĐœĐ°Ń ĐČŃжОĐČĐ°Đ”ĐŒĐŸŃŃŃ: ĐŸĐ±ŃĐ°Ń â 96%, бДзŃĐ”ŃОЎОĐČĐœĐ°Ń â 50%. ĐĐ»ŃŃĐ”ĐČŃĐ” ŃĐ»ĐŸĐČĐ°: ĐșĐŸĐ»ĐŸŃĐ”ĐșŃĐ°Đ»ŃĐœŃĐč
ŃĐ°Đș, ĐŒĐ”ŃĐ°ŃŃĐ°Đ·Ń ĐČ ĐżĐ”ŃĐ”ĐœĐž,
бДĐČĐ°ŃОзŃĐŒĐ°Đ±, ĐșапДŃĐžŃĐ°Đ±ĐžĐœ,
ĐŸĐșŃалОплаŃĐžĐœ.The results of multicentre study of II phase
are analyzed. The efficacy and safety of combined
regimen CAPOX + bevacizumab in adjuvant therapy
of patients not selected for upfront resection and with
colorectal cancer metastasis in liver is demonstrated. The
respectability was achieved in 44% of cases, 12-month
survival, overall, survival 96%, without relapse 50%. Key Words: bevacizumab, capecitabine, colorectal
cancer, liver metastases, oxaliplati
Self-organization of stack-up block copolymers into polymeric supramolecules
Polyethylene oxide âbâ polypropylene oxide -b- polyethylene oxide (EO106PO70EO106) block copolymer self-organizes into polymeric supramolecules, characterized by NMR as phase transition from the isotropic stack-up block structure to the ordered cubic polymeric supramolecular structure. Its dependence on both temperature and copolymer concentration is clearly shown by the changes in line shape and chemical shift of the PO70blockÎČ,Îłresonances
Glycemic Control and Clinical Outcomes in U.S. Patients With COVID-19: Data From the National COVID Cohort Collaborative (N3C) Database
OBJECTIVE The purpose of the study is to evaluate the relationship between HbA1c and severity of coronavirus disease 2019 (COVID-19) outcomes in patients with type 2 diabetes (T2D) with acute COVID-19 infection. RESEARCH DESIGN AND METHODS We conducted a retrospective study using observational data from the National COVID Cohort Collaborative (N3C), a longitudinal, multicenter U.S. cohort of patients with COVID-19 infection. Patients were â„18 years old with T2D and confirmed COVID-19 infection by laboratory testing or diagnosis code. The primary outcome was 30-day mortality following the date of COVID-19 diagnosis. Secondary outcomes included need for invasive ventilation or extracorporeal membrane oxygenation (ECMO), hospitalization within 7 days before or 30 days after COVID-19 diagnosis, and length of stay (LOS) for patients who were hospitalized. RESULTS The study included 39,616 patients (50.9% female, 55.4% White, 26.4% Black or African American, and 16.1% Hispanic or Latino, with mean ± SD age 62.1 ± 13.9 years and mean ± SD HbA1c 7.6% ± 2.0). There was an increasing risk of hospitalization with incrementally higher HbA1c levels, but risk of death plateaued at HbA1c >8%, and risk of invasive ventilation or ECMO plateaued 9%. There was no significant difference in LOS across HbA1c levels. CONCLUSIONS In a large, multicenter cohort of patients in the U.S. with T2D and COVID-19 infection, risk of hospitalization increased with incrementally higher HbA1c levels. Risk of death and invasive ventilation also increased but plateaued at different levels of glycemic control
X(3872) and Other Possible Heavy Molecular States
We perform a systematic study of the possible molecular states composed of a
pair of heavy mesons such as , , in
the framework of the meson exchange model. The exchanged mesons include the
pseudoscalar, scalar and vector mesons. Through our investigation, we find that
(1) the structure X(3764) is not a molecular state; (2) There exists strong
attraction in the range fm for the system with .
If future experiments confirm as a loosely bound molecular state,
its quantum number is probably . Its partner state may
be searched for in the channel; (3) The vector meson exchange
provides strong attraction in the channel together with the
pion exchange. A bound state solution exists with a reasonable cutoff parameter
GeV. X(3872) may be accommodated as a molecular state
dynamically although drawing a very definite conclusion needs further
investigation; (4) The molecular state exists.Comment: 21 pages, 17 tables, 11 figures. Typos correcte
Heavy quarkonium: progress, puzzles, and opportunities
A golden age for heavy quarkonium physics dawned a decade ago, initiated by
the confluence of exciting advances in quantum chromodynamics (QCD) and an
explosion of related experimental activity. The early years of this period were
chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in
2004, which presented a comprehensive review of the status of the field at that
time and provided specific recommendations for further progress. However, the
broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles
could only be partially anticipated. Since the release of the YR, the BESII
program concluded only to give birth to BESIII; the -factories and CLEO-c
flourished; quarkonium production and polarization measurements at HERA and the
Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the
deconfinement regime. All these experiments leave legacies of quality,
precision, and unsolved mysteries for quarkonium physics, and therefore beg for
continuing investigations. The plethora of newly-found quarkonium-like states
unleashed a flood of theoretical investigations into new forms of matter such
as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the
spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b},
and b\bar{c} bound states have been shown to validate some theoretical
approaches to QCD and highlight lack of quantitative success for others. The
intriguing details of quarkonium suppression in heavy-ion collisions that have
emerged from RHIC have elevated the importance of separating hot- and
cold-nuclear-matter effects in quark-gluon plasma studies. This review
systematically addresses all these matters and concludes by prioritizing
directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K.
Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D.
Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A.
Petrov, P. Robbe, A. Vair
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