Pressure dependent electronic properties of MgO polymorphs: A first-principles study of Compton profiles and autocorrelation functions

The first-principles periodic linear combination of atomic orbitals method within the framework of density functional theory implemented in the CRYSTAL06 code has been applied to explore effect of pressure on the Compton profiles and autocorrelation functions of MgO. Calculations are performed for the B1, B2, B3, B4, B8_1 and h-MgO polymorphs of MgO to compute lattice constants and bulk moduli. The isothermal enthalpy calculations predict that B4 to B8_1, h-MgO to B8_1, B3 to B2, B4 to B2 and h-MgO to B2 transitions take place at 2, 9, 37, 42 and 64 GPa respectively. The high pressure transitions B8_1 to B2 and B1 to B2 are found to occur at 340 and 410 GPa respectively. The pressure dependent changes are observed largely in the valence electrons Compton profiles whereas core profiles are almost independent of the pressure in all MgO polymorphs. Increase in pressure results in broadening of the valence Compton profiles. The principal maxima in the second derivative of Compton profiles shifts towards high momentum side in all structures. Reorganization of momentum density in the B1 to B2 structural phase transition is seen in the first and second derivatives before and after the transition pressure. Features of the autocorrelation functions shift towards lower r side with increment in pressure.Comment: 19 pages, 8 figures, accepted for publication in Journal of Materials Scienc

Randomised controlled trial of school-based humanistic counselling for emotional distress in young people: Feasibility study and preliminary indications of efficacy

The purpose of this study was to test the feasibility of a randomised controlled trial comparing six weeks of humanistic school-based counselling versus waiting list in the reduction of emotional distress in young people, and to obtain initial indications of efficacy. Following a screening procedure, young people (13 - 15 years old) who experienced emotional distress were randomised to either humanistic counselling or waiting list in this multi-site study. Outcomes were assessed using a range of self-report mental health measures, with the emotional symptoms subscale of the Strengths and Difficulties Questionnaire (SDQ) acting as the primary outcome indicator. Recruitment procedures were successful, with 32 young people consenting to participate in the trial and 27 completing endpoint measures. Trial procedures were acceptable to all involved in the research. No significant differences were found between the counselling and waiting list groups in reductions in levels of emotional symptoms (Hedges' g = 0.03), but clients allocated to counselling showed significantly greater improvement in prosocial behaviour (g = 0.89) with an average effect size (g) across the nine outcome measures of 0.25. Participants with higher levels of depressive symptoms showed significantly greater change. This study suggested that a randomised controlled trial of counselling in schools is acceptable and feasible, although initial indications of efficacy are mixed

Chlorine Dioxide Is a Size-Selective Antimicrobial Agent

Background / Aims: ClO2, the so-called "ideal biocide", could also be applied as an antiseptic if it was understood why the solution killing microbes rapidly does not cause any harm to humans or to animals. Our aim was to find the source of that selectivity by studying its reaction-diffusion mechanism both theoretically and experimentally. Methods: ClO2 permeation measurements through protein membranes were performed and the time delay of ClO2 transport due to reaction and diffusion was determined. To calculate ClO2 penetration depths and estimate bacterial killing times, approximate solutions of the reaction-diffusion equation were derived. In these calculations evaporation rates of ClO2 were also measured and taken into account. Results: The rate law of the reaction-diffusion model predicts that the killing time is proportional to the square of the characteristic size (e. g. diameter) of a body, thus, small ones will be killed extremely fast. For example, the killing time for a bacterium is on the order of milliseconds in a 300 ppm ClO2 solution. Thus, a few minutes of contact time (limited by the volatility of ClO2) is quite enough to kill all bacteria, but short enough to keep ClO2 penetration into the living tissues of a greater organism safely below 0.1 mm, minimizing cytotoxic effects when applying it as an antiseptic. Additional properties of ClO2, advantageous for an antiseptic, are also discussed. Most importantly, that bacteria are not able to develop resistance against ClO2 as it reacts with biological thiols which play a vital role in all living organisms. Conclusion: Selectivity of ClO2 between humans and bacteria is based not on their different biochemistry, but on their different size. We hope initiating clinical applications of this promising local antiseptic

Parvovirus B19 infection in Tunisian patients with sickle-cell anemia and acute erythroblastopenia

<p>Abstract</p> <p>Background</p> <p>Human parvovirus B19 is the etiologic agent of erythema infectiosum in children. It is also associated with other clinical manifestations in different target groups. Patients with chronic hemolytic anemia are at high risk of developing acute erythroblastopenia following infection by the virus. They usually become highly viremic and pose an increased risk of virus transmission. Close monitoring of such high risk groups is required for epidemiologic surveillance and disease prevention activities. Here we report a molecular epidemiological study on B19 virus infection in Tunisian patients with chronic hemolytic anemia.</p> <p>Methods</p> <p>This study was conducted on 92 young chronic hemolytic anemia patients who attended the same ward at the National Bone Marrow Transplantation Center of Tunis and 46 controls from a different hospital. Screening for IgM and IgG anti-B19 antibodies was performed using commercially available enzyme immunoassays and B19 DNA was detected by nested PCR in the overlapping <it>VP1/VP2 </it>region. DNA was sequenced using dideoxy-terminator cycle sequencing technology.</p> <p>Results</p> <p>Anti-parvovirus B19 IgG antibodies were detected in 26 of 46 sickle-cell anemia patients, 18 of 46 β-thalassemia and 7 of 46 controls. Anti-parvovirus B19 IgM antibodies were detected only in 4 of the sickle-cell anemia patients: two siblings and two unrelated who presented with acute erythroblastopenia at the time of blood collection for this study and had no history of past transfusion. B19 DNA was detected only in sera of these four patients and the corresponding 288 bp nested DNA amplicons were sequenced. The sequences obtained were all identical and phylogenetic analysis showed that they belonged to a new B19 virus strain of Genotype1.</p> <p>Conclusion</p> <p>A new parvovirus B19 strain of genotype1 was detected in four Tunisian patients with sickle-cell anemia. Virus transmission appeared to be nosocomial and resulted in acute erythroblastopenia in the four patients. The possibility of independent transmission of this B19 variant to the patients is unlikely in light of the present epidemiological data. However this possibility cannot be ruled out because of the low genetic variability of the virus.</p

Nurse managers' experience with ethical issues in six government hospitals in Malaysia: A cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Nurse managers have the burden of experiencing frequent ethical issues related to both their managerial and nursing care duties, according to previous international studies. However, no such study was published in Malaysia. The purpose of this study was to explore nurse managers' experience with ethical issues in six government hospitals in Malaysia including learning about the way they dealt with the issues.</p> <p>Methods</p> <p>A cross-sectional study was conducted in August-September, 2010 involving 417 (69.2%) of total 603 nurse managers in the six Malaysian government hospitals. Data were collected using three-part self-administered questionnaire. Part I was regarding participants' demographics. Part II was about the frequency and areas of management where ethical issues were experienced, and scoring of the importance of 11 pre-identified ethical issues. Part III asked how they dealt with ethical issues in general; ways to deal with the 11 pre-identified ethical issues, and perceived stress level. Data were analyzed using descriptive statistics, cross-tabulations and Pearson's Chi-square.</p> <p>Results</p> <p>A total of 397 (95.2%) participants experienced ethical issues and 47.2% experienced them on weekly to daily basis. Experiencing ethical issues were not associated with areas of practice. Top area of management where ethical issues were encountered was "staff management", but "patient care" related ethical issues were rated as most important. Majority would "discuss with other nurses" in dealing generally with the issues. For pre-identified ethical issues regarding "patient care", "discuss with doctors" was preferred. Only 18.1% referred issues to "ethics committees" and 53.0% to the code of ethics.</p> <p>Conclusions</p> <p>Nurse managers, regardless of their areas of practice, frequently experienced ethical issues. For dealing with these, team-approach needs to be emphasized. Proper understanding of the code of ethics is needed to provide basis for reasoning.</p

Short Lag Times for Invasive Tropical Plants: Evidence from Experimental Plantings in Hawai'i

Background: The lag time of an invasion is the delay between arrival of an introduced species and its successful spread in a new area. To date, most estimates of lag times for plants have been indirect or anecdotal, and these estimates suggest that plant invasions are often characterized by lag times of 50 years or more. No general estimates are available of lag times for tropical plant invasions. Historical plantings and documentation were used to directly estimate lag times for tropical plant invasions in Hawai’i. Methodology/Principal Findings: Historical planting records for the Lyon Arboretum dating back to 1920 were examined to identify plants that have since become invasive pests in the Hawaiian Islands. Annual reports describing escape from plantings were then used to determine the lag times between initial plantings and earliest recorded spread of the successful invaders. Among 23 species that eventually became invasive pests, the average lag time between introduction and first evidence of spread was 14 years for woody plants and 5 years for herbaceous plants. Conclusions/Significance: These direct estimates of lag times are as much as an order of magnitude shorter than previous, indirect estimates, which were mainly based on temperate plants. Tropical invaders may have much shorter lag times than temperate species. A lack of direct and deliberate observations may have also inflated many previous lag time estimates. Although there have been documented cases of long lag times due to delayed arrival of a mutualist or environmenta

Detection of Prion Infectivity in Fat Tissues of Scrapie-Infected Mice

Distribution of prion infectivity in organs and tissues is important in understanding prion disease pathogenesis and designing strategies to prevent prion infection in animals and humans. Transmission of prion disease from cattle to humans resulted in banning human consumption of ruminant nervous system and certain other tissues. In the present study, we surveyed tissue distribution of prion infectivity in mice with prion disease. We show for the first time detection of infectivity in white and brown fat. Since high amounts of ruminant fat are consumed by humans and also incorporated into animal feed, fat-containing tissues may pose a previously unappreciated hazard for spread of prion infection

Metabolomic analysis of human disease and its application to the eye

Metabolomics, the analysis of the metabolite profile in body fluids or tissues, is being applied to the analysis of a number of different diseases as well as being used in following responses to therapy. While genomics involves the study of gene expression and proteomics the expression of proteins, metabolomics investigates the consequences of the activity of these genes and proteins. There is good reason to think that metabolomics will find particular utility in the investigation of inflammation, given the multi-layered responses to infection and damage that are seen. This may be particularly relevant to eye disease, which may have tissue specific and systemic components. Metabolomic analysis can inform us about ocular or other body fluids and can therefore provide new information on pathways and processes involved in these responses. In this review, we explore the metabolic consequences of disease, in particular ocular conditions, and why the data may be usefully and uniquely assessed using the multiplexed analysis inherent in the metabolomic approach