265 research outputs found
Measurement of 208 Pb ( n , Îł ) 209 Pb Maxwellian averaged neutron capture cross section
The doubly magic 208Pb nucleus is a bottleneck at the termination of the s-process path due to its very low
neutron capture cross section. This cross section is also important for the decomposition ofs,r processes and U/Th
radiogenic decay contributions to the Pb-Bi solar abundances. The 208Pb(n,Îł )
209Pb cross section was measured
at the Soreq Applied Research Accelerator Facility Phase I using an intense quasi-Maxwellian neutron source
produced by irradiation of the liquid-lithium target with a 1.5-mA continuous-wave proton beam at 1.94 MeV.
The cross section was measured by counting the ÎČ activity from the irradiated lead target. The measurement
allowed us to evaluate the Maxwellian averaged cross section (MACS) at 30 keV obtaining a value of 0.33(2)
mb. This has been compared with the earlier activation and time-of-flight measurements found in the literature.
The MACS cross-sectional value of the 63Cu(n,Îł )
64Cu reaction was determined in the same experiment and is
compared to a recent published value.EC NeutAndalus (FP7-PEOPLE-2012-CIG No. 334315
Oxazepam and temazepam attenuate paroxetine-induced elevation of serotonin levels in guinea-pig hippocampus
Selective serotonin (5-HT) reuptake inhibitors (SSRIs) are used as a first-line treatment in depression. However, many depressed patients are also treated with benzodiazepines to alleviate increased anxiety and sleep disturbances normally associated with depression. Since benzodiazepines inhibit 5-HT neuronal firing activity, they might attenuate SSRI-induced increase in extracellular 5-HT levels. This study aimed to assess, using in-vivo microdialysis, the effects of the benzodiazepines oxazepam or temazepan on the SSRI paroxetine-induced 5-HT increase in the hippocampus of freely moving guinea-pigs. It was found that the acute systemic administration of paroxetine increased extracellular 5-HT levels. Pre-administration of oxazepam or temazepam significantly diminished the paroxetine-induced elevation of extracellular 5-HT levels (from 350% to 200% of baseline). It was concluded that benzodiazepines attenuate the ability of SSRIs to elevate hippocampal 5-HT levels. Thus, co-administration of benzodiazepines might affect the therapeutic efficacy of SSRI treatment
The DLV System for Knowledge Representation and Reasoning
This paper presents the DLV system, which is widely considered the
state-of-the-art implementation of disjunctive logic programming, and addresses
several aspects. As for problem solving, we provide a formal definition of its
kernel language, function-free disjunctive logic programs (also known as
disjunctive datalog), extended by weak constraints, which are a powerful tool
to express optimization problems. We then illustrate the usage of DLV as a tool
for knowledge representation and reasoning, describing a new declarative
programming methodology which allows one to encode complex problems (up to
-complete problems) in a declarative fashion. On the foundational
side, we provide a detailed analysis of the computational complexity of the
language of DLV, and by deriving new complexity results we chart a complete
picture of the complexity of this language and important fragments thereof.
Furthermore, we illustrate the general architecture of the DLV system which
has been influenced by these results. As for applications, we overview
application front-ends which have been developed on top of DLV to solve
specific knowledge representation tasks, and we briefly describe the main
international projects investigating the potential of the system for industrial
exploitation. Finally, we report about thorough experimentation and
benchmarking, which has been carried out to assess the efficiency of the
system. The experimental results confirm the solidity of DLV and highlight its
potential for emerging application areas like knowledge management and
information integration.Comment: 56 pages, 9 figures, 6 table
Electron-Electron Interaction in Disordered Mesoscopic Systems: Weak Localization and Mesoscopic Fluctuations of Polarizability and Capacitance
The weak localization correction and the mesoscopic fluctuations of the
polarizability and the capacitance of a small disordered sample are studied
systematically in 2D and 3D geometries. While the grand canonical ensemble
calculation gives the positive magnetopolarizability, in the canonical ensemble
(appropriate for isolated samples) the sign of the effect is reversed. The
magnitude of mesoscopic fluctuations for a single sample exceeds considerably
the value of the weak localization correction.Comment: 13 pages Latex, 3 .eps figures included. To appear in Phys. Rev. B.
Minor corrections, in particular in formulae; new references adde
Do Stress Responses Promote Leukemia Progression? An Animal Study Suggesting a Role for Epinephrine and Prostaglandin-E2 through Reduced NK Activity
In leukemia patients, stress and anxiety were suggested to predict poorer prognosis. Oncological patients experience ample physiological and psychological stress, potentially leading to increased secretion of stress factors, including epinephrine, corticosteroids, and prostaglandins. Here we tested whether environmental stress and these stress factors impact survival of leukemia-challenged rats, and studied mediating mechanisms. F344 rats were administered with a miniscule dose of 60 CRNK-16 leukemia cells, and were subjected to intermittent forced swim stress or to administration of physiologically relevant doses of epinephrine, prostaglandin-E2 or corticosterone. Stress and each stress factor, and/or their combinations, doubled mortality rates when acutely applied simultaneously with, or two or six days after tumor challenge. Acute administration of the ÎČ-adrenergic blocker nadolol diminished the effects of environmental stress, without affecting baseline survival rates. Prolonged ÎČ-adrenergic blockade or COX inhibition (using etodolac) also increased baseline survival rates, possibly by blocking tumor-related or normal levels of catecholamines and prostaglandins. Searching for mediating mechanisms, we found that each of the stress factors transiently suppressed NK activity against CRNK-16 and YAC-1 lines on a per NK basis. In contrast, the direct effects of stress factors on CRNK-16 proliferation, vitality, and VEGF secretion could not explain or even contradicted the in vivo survival findings. Overall, it seems that environmental stress, epinephrine, and prostaglandins promote leukemia progression in rats, potentially through suppressing cell mediated immunity. Thus, patients with hematological malignancies, which often exhibit diminished NK activity, may benefit from extended ÎČ-blockade and COX inhibition
Opportunities for high-energy neutron- and deuteron-induced measurements for fusion technology at the Soreq applied research accelerator facility (SARAF)
The Soreq Applied Research Accelerator Facility (SARAF) will be based on a 40 MeV, 5 mA CW (continuous wave) proton/deuteron superconducting linear accelerator, currently under construction at Soreq Nuclear Research Center in Yavne, Israel. It is planned to commence operation during 2025. Experiments at SARAF could provide data on high-energy deuteron- and neutron-induced cross-sections, yields and radiation damage, which are invaluable for the design and operation of the International Fusion Materials Irradiation Facility-DEMO-Oriented NEutron Source (IFMIF-DONES), and fusion technology in general. Pulsed beams (âŒ1 nsec) of variable energy deuterons will irradiate a lithium target and generate pulsed neutron beams with energy up to âŒ55 MeV, which will be used to measure energy-dependent neutron-induced differential cross-sections, utilizing time of flight techniques. Impinging continuous wave (CW) 40 MeV deuteron beams on a unique gallium-indium (GaIn) liquid-jet target, will generate a neutron rate of more than 1 Ă 1015 n/sec, with energies up to âŒ45 MeV. We plan to use this high rate to measure integral neutron-induced reaction yields of all channels simultaneously, employing an original novel method that will identify the reaction-produced nuclei via accurate mass measurement. The neutron-energy dependence of the yields could be deduced by combining measurements at various deuteron energies. The measured cross-sections and yields at SARAF may predict the activation characteristics of construction materials of IFMIF-DONES and future fusion reactors. The deuteron beams will also be used directly to measure cross-sections via in-beam and offline methods. The high neutron and deuteron rates will extend SARAFâs reach to rare materials. The deuteron beam power density on the liquid GaIn target will be 100 kW/cm2 (similar to IFMIF-DONES) on a 2 cm2 spot. The resulting neutron flux on small secondary samples will be in the 1013 n/cm2/s level, only an order of magnitude less than IFMIF-DONES. Therefore, SARAF may serve as a pilot facility for fusion-related radiation damage studies, providing important information towards the design of IFMIF-DONES
Nitrous oxide may not increase the risk of cancer recurrence after colorectal surgery: a follow-up of a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Even the best cancer surgery is usually associated with minimal residual disease. Whether these remaining malignant cells develop into clinical recurrence is at least partially determined by adequacy of host defense, especially natural killer cell function. Anesthetics impair immune defenses to varying degrees, but nitrous oxide appears to be especially problematic. We therefore tested the hypothesis that colorectal-cancer recurrence risk is augmented by nitrous oxide administration during colorectal surgery.</p> <p>Methods</p> <p>We conducted a 4- to 8-year follow-up of 204 patients with colorectal cancer who were randomly assigned to 65% nitrous oxide (n = 97) or nitrogen (n = 107), balanced with isoflurane and remifentanil. The primary outcome was the time to cancer recurrence. Our primary analysis was a multivariable Cox-proportional-hazards regression model that included relevant baseline variables. In addition to treatment group, the model considered patient age, tumor grade, dissemination, adjacent organ invasion, vessel invasion, and the number of nodes involved. The study had 80% power to detect a 56% or greater reduction in recurrence rates (i.e., hazard ratio of 0.44 or less) at the 0.05 significance level.</p> <p>Results</p> <p>After adjusting for significant baseline covariables, risk of recurrence did not differ significantly for nitrous oxide and nitrogen, with a hazard ratio estimate (95% CI) of 1.10 (0.66, 1.83), <it>P </it>= 0.72. No two-way interactions with the treatment were statistically significant.</p> <p>Conclusion</p> <p>Colorectal-cancer recurrence risks were not greatly different in patients who were randomly assigned to 65% nitrous oxide or nitrogen during surgery. Our results may not support avoiding nitrous oxide use to prevent recurrence of colorectal cancer.</p> <p>Implications Statement</p> <p>The risk of colorectal cancer recurrence was similar in patients who were randomly assigned to 65% nitrous oxide or nitrogen during colorectal surgery.</p> <p>Trial Registration</p> <p>Current Controlled Clinical Trials NCT00781352 <url>http://www.clinicaltrials.gov</url></p
Repression of Mitochondrial Translation, Respiration and a Metabolic Cycle-Regulated Gene, SLF1, by the Yeast Pumilio-Family Protein Puf3p
Synthesis and assembly of the mitochondrial oxidative phosphorylation (OXPHOS) system requires genes located both in the nuclear and mitochondrial genomes, but how gene expression is coordinated between these two compartments is not fully understood. One level of control is through regulated expression mitochondrial ribosomal proteins and other factors required for mitochondrial translation and OXPHOS assembly, which are all products of nuclear genes that are subsequently imported into mitochondria. Interestingly, this cadre of genes in budding yeast has in common a 3âČ-UTR element that is bound by the Pumilio family protein, Puf3p, and is coordinately regulated under many conditions, including during the yeast metabolic cycle. Multiple functions have been assigned to Puf3p, including promoting mRNA degradation, localizing nucleus-encoded mitochondrial transcripts to the outer mitochondrial membrane, and facilitating mitochondria-cytoskeletal interactions and motility. Here we show that Puf3p has a general repressive effect on mitochondrial OXPHOS abundance, translation, and respiration that does not involve changes in overall mitochondrial biogenesis and largely independent of TORC1-mitochondrial signaling. We also identified the cytoplasmic translation factor Slf1p as yeast metabolic cycle-regulated gene that is repressed by Puf3p at the post-transcriptional level and promotes respiration and extension of yeast chronological life span when over-expressed. Altogether, these results should facilitate future studies on which of the many functions of Puf3p is most relevant for regulating mitochondrial gene expression and the role of nuclear-mitochondrial communication in aging and longevity
The Genetic Landscape and Epidemiology of Phenylketonuria
Phenylketonuria (PKU), caused by variants in the phenylalanine hydroxylase (PAH) gene, is the most common autosomal-recessive Mendelian phenotype of amino acid metabolism. We estimated that globally 0.45 million individuals have PKU, with global prevalence 1:23,930 live births (range 1:4,500 [Italy]â1:125,000 [Japan]). Comparing genotypes and metabolic phenotypes from 16,092 affected subjects revealed differences in disease severity in 51 countries from 17 world regions, with the global phenotype distribution of 62% classic PKU, 22% mild PKU, and 16% mild hyperphenylalaninemia. A gradient in genotype and phenotype distribution exists across Europe, from classic PKU in the east to mild PKU in the southwest and mild hyperphenylalaninemia in the south. The c.1241A>G (p.Tyr414Cys)-associated genotype can be traced from Northern to Western Europe, from Sweden via Norway, to Denmark, to the Netherlands. The frequency of classic PKU increases from Europe (56%) via Middle East (71%) to Australia (80%). Of 758 PAH variants, c.1222C>T (p.Arg408Trp) (22.2%), c.1066â11G>A (IVS10â11G>A) (6.4%), and c.782G>A (p.Arg261Gln) (5.5%) were most common and responsible for two prevalent genotypes: p.[Arg408Trp];[Arg408Trp] (11.4%) and c.[1066â11G>A];[1066â11G>A] (2.6%). Most genotypes (73%) were compound heterozygous, 27% were homozygous, and 55% of 3,659 different genotypes occurred in only a single individual. PAH variants were scored using an allelic phenotype value and correlated with pre-treatment blood phenylalanine concentrations (n = 6,115) and tetrahydrobiopterin loading test results (n = 4,381), enabling prediction of both a genotype-based phenotype (88%) and tetrahydrobiopterin responsiveness (83%). This study shows that large genotype databases enable accurate phenotype prediction, allowing appropriate targeting of therapies to optimize clinical outcome.Fil: Hillert, Alicia. No especifĂca;Fil: Anikster, Yair. No especifĂca;Fil: Belanger Quintana, Amaya. No especifĂca;Fil: Burlina, Alberto. No especifĂca;Fil: Burton, Barbara K.. No especifĂca;Fil: Carducci, Carla. No especifĂca;Fil: Chiesa, Ana Elena. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Centro de Investigaciones EndocrinolĂłgicas "Dr. CĂ©sar Bergada". Gobierno de la Ciudad de Buenos Aires. Centro de Investigaciones EndocrinolĂłgicas "Dr. CĂ©sar Bergada". FundaciĂłn de EndocrinologĂa Infantil. Centro de Investigaciones EndocrinolĂłgicas "Dr. CĂ©sar Bergada"; ArgentinaFil: Christodoulou, John. No especifĂca;Fil: Dordevic, Maja. No especifĂca;Fil: Desviat, Lourdes R.. No especifĂca;Fil: Eliyahu, Aviva. No especifĂca;Fil: Evers, Roeland A.F.. No especifĂca;Fil: Fajkusova, Lena. No especifĂca;Fil: Feillet, Francois. No especifĂca;Fil: Bonfim Freitas, Pedro E.. No especifĂca;Fil: Gizewska, MarĂa. No especifĂca;Fil: Gundorova, Polina. No especifĂca;Fil: Karall, Daniela. No especifĂca;Fil: Kneller, Katya. No especifĂca;Fil: Kutsev, Sergey I.. No especifĂca;Fil: Leuzzi, Vincenzo. No especifĂca;Fil: Levy, Harvey L.. No especifĂca;Fil: Lichter Koneck, Uta. No especifĂca;Fil: Muntau, Ania C.. No especifĂca;Fil: Namour, Fares. No especifĂca;Fil: Oltarzewsk, Mariusz. No especifĂca;Fil: Paras, Andrea. No especifĂca;Fil: Perez, BelĂ©n. No especifĂca;Fil: Polak, Emil. No especifĂca;Fil: Polyakov, Alexander V.. No especifĂca;Fil: Porta, Francesco. No especifĂca;Fil: Rohrbach, Marianne. No especifĂca;Fil: Scholl BĂŒrgi, Sabine. No especifĂca;Fil: SpĂ©cola, Norma. No especifĂca;Fil: Stojiljkovic, Maja. No especifĂca;Fil: Shen, Nan. No especifĂca;Fil: Santana da Silva, Luiz C.. No especifĂca;Fil: Skouma, Anastasia. No especifĂca;Fil: van Spronsen, Francjan. No especifĂca;Fil: Stoppioni, Vera. No especifĂca;Fil: Thöny, Beat. No especifĂca;Fil: Trefz, Friedrich K.. No especifĂca;Fil: Vockley, Jerry. No especifĂca;Fil: Yu, Youngguo. No especifĂca;Fil: Zschocke, Johannes. No especifĂca;Fil: Hoffmann, Georg F.. No especifĂca;Fil: Garbade, Sven F.. No especifĂca;Fil: Blau, Nenad. No especifĂca
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