Self-trapped electrons and holes in PbBr2_2 crystals

We have directly observed self-trapped electrons and holes in PbBr$_{2}$ crystals with electron-spin-resonance (ESR) technique. The self-trapped states are induced below 8 K by two-photon interband excitation with pulsed 120-fs-width laser light at 3.10 eV. Spin-Hamiltonian analyses of the ESR signals have revealed that the self-trapping electron centers are the dimer molecules of Pb$_2$$^{3+}$ along the crystallographic a axis and the self-trapping hole centers are those of Br$_2$$^-$ with two possible configurations in the unit cell of the crystal. Thermal stability of the self-trapped electrons and holes suggests that both of them are related to the blue-green luminescence band at 2.55 eV coming from recombination of spatially separated electron-hole pairs.Comment: 8 pages (7 figures, 2 tables), ReVTEX; revised the text and figures 1, 4, and

Дослідження проблеми здимання гірських порід із застосуванням апарату теорії стійкості механічних систем: постановка задачі

Описаны возможные направления развития исследований явлений, сопровождающихся большими пластическими деформациями (исследование геодинамических явлений, явлений потери устойчивости почвы выработки (пучения) и т.п.).Possible directions of development of researches of the effects, attended with large plastic strains are described (research of the geodynamics effects, effects of losses of roadway floor sustainability (rock heaving) etc.)

Op weg naar maatschappelijke kosten-batenanalyses voor preventie en zorg : Themarapport Volksgezondheid Toekomst Verkenning 2014

Een maatschappelijke kosten-batenanalyse (MKBA) biedt een overzicht van de voor- en nadelen van een maatregel, zoals de aanleg van een weg of woonwijk. Door deze voor- en nadelen zoveel mogelijk te kwantificeren en in euro's uit te drukken, geeft een MKBA inzicht in het effect van de maatregel op de welvaart in Nederland. Met die informatie kan een MKBA de politieke besluitvorming ondersteunen en verhelderen. Om de kwaliteit en de vergelijkbaarheid van MKBA's te waarborgen hebben het Centraal Planbureau (CPB) en het Planbureau voor de Leefomgeving (PBL) in 2013 een algemene MKBA-leidraad opgesteld. De ministeries zullen de komende jaren werkwijzers maken, waarin de principes van de algemene leidraad worden geconcretiseerd voor het eigen beleidsterrein. Dit rapport van het RIVM is bedoeld als een eerste stap om te komen tot zo'n werkwijzer voor volksgezondheid en zorg. In het rapport laten we zien wat de consequenties zijn als vanuit de MKBA-methode naar dit terrein wordt gekeken. Een goede MKBA kan ook op het terrein van volksgezondheid en zorg een bijdrage leveren aan de beleidsvoorbereiding en de besluitvorming. Daarvoor moeten nog wel enkele methodologische aspecten nader uitgewerkt en bediscussieerd worden. Belangrijke thema's daarbij zijn: effecten op de verdeling van welvaart tussen groepen mensen, de waarde van gezondheid in euro's, het kwantificeren van arbeidsbaten en het waarderen van toekomstige baten (de 'discontovoet'). In dit rapport signaleert en expliciteert het RIVM de belangrijkste vragen en dilemma's waarop de werkwijzer een antwoord moet geven

Is severity of motor coordination difficulties related to co-morbidity in children at risk for developmental coordination disorder?

Aim of the study was to investigate whether 7-9 year old children with severe motor difficulties are more at risk of additional difficulties in activities in daily living, academic skills, attention and social skills than children with moderate motor difficulties. Children (N=6959) from a population based cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC), were divided into three groups based on their scores on the ALSPAC Coordination Test at age 7: control children (scores above 15th centile; N=5719 [82.1%]); children with moderate (between 5th and 15th centile; N=951 [13.7%]); and children with severe motor difficulties (below 5th centile N=289 [4.2%]). Children with neurological disorders or an IQ<70 were excluded. Logistic regression was used to compare children with moderate and severe motor coordination difficulties with each other and with control children regarding their risk of co-morbidity defined as significant (<10th centile) difficulties with activities of daily living (ADL); academic skills (reading, spelling and handwriting); attention; social skills (social cognition and nonverbal skills). Children with severe motor difficulties demonstrated a higher risk of difficulties in ADL, handwriting, attention, reading, and social cognition than children with moderate motor difficulties, who in turn had a higher risk of difficulties than control children in five out of seven domains. Screening and intervention of co-morbid problems is recommended for children with both moderate and severe motor difficulties

Self-trapped states and the related luminescence in PbCl2_2 crystals

We have comprehensively investigated localized states of photoinduced electron-hole pairs with electron-spin-resonance technique and photoluminescence (PL) in a wide temperature range of 5-200 K. At low temperatures below 70 K, holes localize on Pb$^{2+}$ ions and form self-trapping hole centers of Pb$^{3+}$. The holes transfer to other trapping centers above 70 K. On the other hand, electrons localize on two Pb$^{2+}$ ions at higher than 50 K and form self-trapping electron centers of Pb$_2$$^{3+}$. From the thermal stability of the localized states and PL, we clarify that blue-green PL band at 2.50 eV is closely related to the self-trapped holes.Comment: 8 pages (10 figures), ReVTEX; removal of one figure, Fig. 3 in the version

Влияние условий синтеза на размер наночастиц железа

Показана возможность получения наночастиц железа разного размера путем варьирования условий синтеза. Методами электронной микроскопии, ИК спектроскопии и электронной дифракции изучена их морфология и структура. Установлено, что при нанесении наночастиц железа на угольный носитель размер, распределение и строение частиц не меняется.Показана можливість отримання наночастинок заліза різного розміру шляхом варіювання умов синтезу. Методами електронної мікроскопії, ІЧ спектроскопії та електронної дифракції вивчено їх морфологію та структуру. Знайдено, що при нанесенні наночастинок заліза на носії розмір, розподіл та будова не змінюється.The preparation of monodisperse Fe nanoparticles of various sizes by varying synthesis conditions is reported. Nanoparticles have been studied by transmission electron microscopy, IR spectroscopy, and electron diffraction. It was shown that Fe nanoparticles do not change its size, distribution, and structure after impregnation of support

Brain changes due to hypoxia during light anaesthesia can be prevented by deepening anaesthesia:a study in rats

In anaesthetic practice the risk of cerebral ischemic/hypoxic damage is thought to be attenuated by deep anaesthesia. The rationale is that deeper anaesthesia reduces cerebral oxygen demand more than light anaesthesia, thereby increasing the tolerance to ischemia or hypoxia. However, evidence to support this is scarce. We thus investigated the influence of light versus deep anaesthesia on the responses of rat brains to a period of hypoxia. In the first experiment we exposed adult male Wistar rats to deep or light propofol anaesthesia and then performed [18F]- Fludeoxyglucose (FDG) Positron Emission Tomography (PET) scans to verify the extent of cerebral metabolic suppression. In subsequent experiments, rats were subjected to light/deep propofol anaesthesia and then exposed to a period of hypoxia or ongoing normoxia (n = 9-11 per group). A further 5 rats, not exposed to anaesthesia or hypoxia, served as controls. Four days later a Novel Object Recognition (NOR) test was performed to assess mood and cognition. After another 4 days, the animals were sacrificed for later immunohistochemical analyses of neurogenesis/neuroplasticity (Doublecortin; DCX), Brain Derived Neurotrophic Factor (BDNF) expression and neuroinflammation (Ionized calcium-binding adaptor protein-1; Iba-1) in hippocampal and piriform cortex slices. The hippocampi of rats subjected to hypoxia during light anaesthesia showed lower DCX positivity, and therefore lower neurogenesis, but higher BDNF levels and microglia hyper-ramification. Exploration was reduced, but no significant effect on NOR was observed. In the piriform cortex, higher DCX positivity was observed, associated with neuroplasticity. All these effects were attenuated by deep anaesthesia. Deepening anaesthesia attenuated the brain changes associated with hypoxia. Hypoxia during light anaesthesia had a prolonged effect on the brain, but no impairment in cognitive function was observed. Although reduced hippocampal neurogenesis may be considered unfavourable, higher BDNF expression, associated with microglia hyper-ramification may suggest activation of repair mechanisms. Increased neuroplasticity observed in the piriform cortex supports this, and might reflect a prolonged state of alertness rather than damage

The effectiveness of Video-feedback Intervention to promote Positive Parenting for Foster Care (VIPP-FC)

Background: Foster children are at higher risk of the development of behavior and emotional problems, which can contribute to the development of insecure attachment bonds with their foster parents and (subsequently) to placement breakdown. Sensitive parenting might minimize the adverse effects of the behavior and emotional problems. Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline in Foster Care (VIPP-FC) is an adaptation of the evidence-based Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline (VIPP-SD) and aims at increasing sensitive parenting and the use of sensitive discipline strategies of foster parents. The current study is the first to examine the effectiveness of VIPP-FC. Methods: A randomized controlled trial is used with 60 foster parent-child dyads (intervention group n=30, control group n=30). The primary outcomes are parental sensitivity, parental disciplining, and parental attitudes towards parenting. Data about attachment (in)security, behavioral and emotional problems, neurobiological parameters, and possible confounders is additionally collected. Discussion: Examining the effectiveness of VIPP-FC contributes to the knowledge of evidence-based prevention and intervention programs needed in foster care practice

CLINICAL TRIAL PARTICIPATION AFTER ACUTE CORONARY SYNDROME AND ASSOCIATED OUTCOMES: INSIGHT FROM THE ACTION REGISTRY-GWTG

Background/Aims: In liver diseases, reactive oxygen species (ROS) are involved in cell death and liver injury, but the mechanisms are not completely elucidated. To elucidate the mechanisms of hepatocyte cell death induced by the ROS superoxide anions and hydrogen peroxide, primary cultures of hepatocytes were exposed to the superoxide anion donor menadione (10-50 mu mol/L) or H(2)O(2) (1-5 mmol/L). Hepatocytes were also treated with caspases and MAPKs inhibitors, superoxide dismutase (PEG-SOD) and SNAP, a nitric oxide donor. Apoptosis was determined by measuring caspase-9, -6, -3 activation and cleaved PARP, and necrotic cell death by Sytox Green staining. Results: (1) Menadione (50 mu mol/L) induces JNK phosphorylation, caspase-9, -6, -3 activation, PARP cleavage and apoptosis. Superoxide anions-induced apoptosis is dependent on JNK activity. Menadione (50 mu mol/L) induces the phosphorylation of ERK1/2 and this attenuates cell death. (2) H(2)O(2) increases necrotic cell death at high concentration or when H(2)O(2) detoxification is impaired. H202 does not activate MAPKs signalling. (3) PEG-SOD prevents ERK1/2-, JNK- phosphorylation, caspase activation and apoptosis induced by menadione. Glutathione depletion increases menadione-induced apoptosis. (4) SNAP abolishes menadione-induced apoptosis but increases necrotic cell death. Conclusions: In normal hepatocytes, superoxide anions-induced caspase activation and apoptosis is dependent on JNK activity and totally abolished by superoxide scavengers. (c) 2005 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved