485 research outputs found

    Finite size effects and magnetic order in the spin-1/2 honeycomb lattice compound InCu{2/3}V{1/3}O{3}

    Full text link
    High field electron spin resonance, nuclear magnetic resonance and magnetization studies addressing the ground state of the quasi two-dimensional spin-1/2 honeycomb lattice compound InCu{2/3}V{1/3}O{3} are reported. Uncorrelated finite size structural domains occurring in the honeycomb planes are expected to inhibit long range magnetic order. Surprisingly, ESR data reveal the development of two collinear antiferromagnetic (AFM) sublattices below ~ 20 K whereas NMR results show the presence of the staggered internal field. Magnetization data evidence a spin reorientation transition at ~ 5.7 T. Quantum Monte-Carlo calculations show that switching on the coupling between the honeycomb spin planes in a finite size cluster yields a Neel-like AFM spin structure with a substantial staggered magnetization at finite temperatures. This may explain the occurrence of a robust AFM state in InCu{2/3}V{1/3}O{3} despite an unfavorable effect of structural disorder.Comment: revised version, accepted as a Rapid Communication in Phys. Rev. B (2010

    The incarnation of the Nersesyan-Tsvelik model in (NO)[Cu(NO3)3]

    Full text link
    The topology of the magnetic interactions of the copper spins in the nitrosonium nitratocuprate (NO)[Cu(NO3)3] suggests that it could be a realization of the Nersesyan-Tsvelik model, whose ground state was argued to be either a resonating valence bond (RVB) state or a valence bond crystal (VBC). The measurement of thermodynamic and resonant properties reveals a behavior inherent to low dimensional spin S = 1/2 systems and provides indeed no evidence for the formation of long-range magnetic order down to 1.8 K.Comment: 12 pages, 6 figure

    Mode of delivery among HIV-Infected pregnant women in Philadelphia, 2005-2013

    Get PDF
    Objective Current guidelines call for HIV-infected women to deliver via scheduled Caesarean when the maternal HIV viral load (VL) is >1,000 copies/ml. We describe the mode of delivery among HIV-infected women and evaluate adherence to relevant recommendations. Study Design We performed a population-based surveillance analysis of HIV-infected pregnant women in Philadelphia from 2005 to 2013, comparing mode of delivery (vaginal, scheduled Caesarean, or emergent Caesarean) by VL during pregnancy, closest to the time of delivery (≤1,000 copies/ml versus an unknown VL or VL >1,000 copies/ml) and associated factors in multivariable analysis. Results Our cohort included 824 deliveries from 648 HIV-infected women, of whom 69.4% had a VL ≤1,000 copies/ml and 30.6% lacked a VL or had a VL >1,000 copies/ml during pregnancy, closest to the time of delivery. Mode of delivery varied by VL: 56.6% of births were vaginal, 30.1% scheduled Caesarean, and 13.3% emergent Caesarean when the VL was ≤1,000 copies/ml; when the VL was unknown or >1,000 copies/ml, 32.9% of births were vaginal, 49.9% scheduled Caesarean and 17.5% emergent Caesarean. In multivariable analyses, Hispanic women (adjusted odds ratio (AOR) 0.17, 95% Confidence Interval (CI) 0.04–0.76) and non-Hispanic black women (AOR 0.27, 95% CI 0.10–0.77) were less to likely to deliver via scheduled Caesarean compared to non-Hispanic white women. Women who delivered prior to 38 weeks’ gestation (AOR 0.37, 95% CI 0.18–0.76) were also less likely to deliver via scheduled Caesarean compared to women who delivered after 38 weeks’ gestation. An interaction term for race and gestational age at delivery was significant in multivariable analysis. Non-Hispanic black (AOR 0.06, 95% CI 0.01–0.36) and Hispanic women (AOR 0.03, 95% CI 0.00–0.59) were more likely to deliver prematurely and less likely to deliver via scheduled C-section compared to non-Hispanic white women. Having a previous Caesarean (AOR 27.77, 95% CI 8.94–86.18) increased the odds of scheduled Caesarean delivery. Conclusions Only half of deliveries for women with an unknown VL or VL >1,000 copies/ml occurred via scheduled Caesarean. Delivery prior to 38 weeks, particularly among minority women, resulted in a missed opportunity to receive a scheduled Caesarean. However, even when delivering at or after 38 weeks’ gestation, a significant proportion of women did not get a scheduled Caesarean when indicated, suggesting a need for focused public health interventions to increase the proportion of women achieving viral suppression during pregnancy and delivering via scheduled Caesarean when indicated

    Melhoria da qualidade de filetes de tilápia do Nilo congelados com óleo de alecrim e tomilho

    Get PDF
    The food industry and the frozen fish sector in particular have benefitted greatly from advancements in food processing technologies. This study investigated the effect of adding natural antioxidants such as rosemary and thyme oil to frozen fillets of Nile tilapia (Oreochromis niloticus) in order to preserve their quality for consumers. Fillets were treated with rosemary and thyme at two concentrations (1% and 1.5%) and then were stored at 4°C. Samples were analyzed over 4 days for bacteriological (aerobic plate count, psychotropic count, and coliform count), chemical (determination of pH, thiobarbituric acid reactive substances-TBARS, and total volatile base nitrogen-TVB-N), and sensory quality examination (color, texture, and odor). Significant differences (P < 0.05) were observed among different groups in terms of aerobic plate count, psychotropic count, and coliform count during the storage. Moreover, pH, TVB-N, and TBARS mean values in the treated groups were lower than those in the untreated group. The best sensory quality was obtained at the highest concentrations (1.5%) of thyme and rosemary oil

    On bi-hamiltonian geometry of some integrable systems on the sphere with cubic integral of motion

    Full text link
    We obtain bi-Hamiltonian structure for a family of integrable systems on the sphere S with an additional integral of third order in momenta. These results are applied to the Goryachev system and Goryachev-Chaplygin top for which we give an explicit procedure to find the separated coordinates and the separated relations.Comment: 11 pages, LaTeX with AMS fonts, corrected typo

    The Application of Nanoparticles of Waste Tires in Remediating Boron from Desalinated Water

    Get PDF
    A waste tire rubber (WTR) collected from the remains discarded tires has exhibited a noteworthy capacity to adsorb Boron. In the current study, the boron adsorption remediation from water at selected pH values, initial boron concentration, contact time, adsorbent dosage and particle size were examined using the WTR, the chemically modified WTR, and nano-WTR. The adsorption isotherms were best fitted to the Freundlich model with a high correlation coefficient (R2 :0.89-0.99), while the adsorption kinetics were satisfactorily described by the pseudo second order kinetic equation with correlation coefficient (R2: 1).The boron remediation using the WTR, the chemically modified-WTR and nano-WTR at low boron concentration (≤ 17.7 mg/L) were comparable with other adsorbents. The highest adsorption capacities for WTR, chemically modified-WTR and nano-WTR at initial concentration of 17.5 mg/L were 16.7 ± 1.3 mg/g, 13.8 ± 1.9 mg/g and 12.7 ± 1.8mg/g, respectively.This publication was made possible by UREP # (19-171-1-031) from the Qatar National Research Fund (a member of Qatar Foundation)

    Cellular localization, accumulation and trafficking of double-walled carbon nanotubes in human prostate cancer cells

    Get PDF
    Carbon nanotubes (CNTs) are at present being considered as potential nanovectors with the ability to deliver therapeutic cargoes into living cells. Previous studies established the ability of CNTs to enter cells and their therapeutic utility, but an appreciation of global intracellular trafficking associated with their cellular distribution has yet to be described. Despite the many aspects of the uptake mechanism of CNTs being studied, only a few studies have investigated internalization and fate of CNTs inside cells in detail. In the present study, intracellular localization and trafficking of RNA-wrapped, oxidized double-walled CNTs (oxDWNT–RNA) is presented. Fixed cells, previously exposed to oxDWNT–RNA, were subjected to immunocytochemical analysis using antibodies specific to proteins implicated in endocytosis; moreover cell compartment markers and pharmacological inhibitory conditions were also employed in this study. Our results revealed that an endocytic pathway is involved in the internalization of oxDWNT–RNA. The nanotubes were found in clathrin-coated vesicles, after which they appear to be sorted in early endosomes, followed by vesicular maturation, become located in lysosomes. Furthermore, we observed co-localization of oxDWNT–RNA with the small GTP-binding protein (Rab 11), involved in their recycling back to the plasma membrane via endosomes from the trans-golgi network

    Circulating adrenomedullin estimates survival and reversibility of organ failure in sepsis: the prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock-1 (AdrenOSS-1) study

    Get PDF
    Background: Adrenomedullin (ADM) regulates vascular tone and endothelial permeability during sepsis. Levels of circulating biologically active ADM (bio-ADM) show an inverse relationship with blood pressure and a direct relationship with vasopressor requirement. In the present prospective observational multinational Adrenomedullin and Outcome in Sepsis and Septic Shock 1 (, AdrenOSS-1) study, we assessed relationships between circulating bio-ADM during the initial intensive care unit (ICU) stay and short-term outcome in order to eventually design a biomarker-guided randomized controlled trial. Methods: AdrenOSS-1 was a prospective observational multinational study. The primary outcome was 28-day mortality. Secondary outcomes included organ failure as defined by Sequential Organ Failure Assessment (SOFA) score, organ support with focus on vasopressor/inotropic use, and need for renal replacement therapy. AdrenOSS-1 included 583 patients admitted to the ICU with sepsis or septic shock. Results: Circulating bio-ADM levels were measured upon admission and at day 2. Median bio-ADM concentration upon admission was 80.5 pg/ml [IQR 41.5-148.1 pg/ml]. Initial SOFA score was 7 [IQR 5-10], and 28-day mortality was 22%. We found marked associations between bio-ADM upon admission and 28-day mortality (unadjusted standardized HR 2.3 [CI 1.9-2.9]; adjusted HR 1.6 [CI 1.1-2.5]) and between bio-ADM levels and SOFA score (p &lt; 0.0001). Need of vasopressor/inotrope, renal replacement therapy, and positive fluid balance were more prevalent in patients with a bio-ADM &gt; 70 pg/ml upon admission than in those with bio-ADM ≤ 70 pg/ml. In patients with bio-ADM &gt; 70 pg/ml upon admission, decrease in bio-ADM below 70 pg/ml at day 2 was associated with recovery of organ function at day 7 and better 28-day outcome (9.5% mortality). By contrast, persistently elevated bio-ADM at day 2 was associated with prolonged organ dysfunction and high 28-day mortality (38.1% mortality, HR 4.9, 95% CI 2.5-9.8). Conclusions: AdrenOSS-1 shows that early levels and rapid changes in bio-ADM estimate short-term outcome in sepsis and septic shock. These data are the backbone of the design of the biomarker-guided AdrenOSS-2 trial. Trial registration: ClinicalTrials.gov, NCT02393781. Registered on March 19, 2015

    Formulation, characterisation and stabilisation of buccal films for paediatric drug delivery of omeprazole

    Get PDF
    This study aimed to develop films for potential delivery of omeprazole (OME) via the buccal mucosa of paediatric patients. Films were prepared using hydroxypropylmethylcellulose (HPMC), methylcellulose (MC), sodium alginate (SA), carrageenan (CA) and metolose (MET) with polyethylene glycol (PEG 400) as plasticiser, OME (model drug) and L-arg (stabiliser). Gels (1% w/w) were prepared at 40°C using water and ethanol with PEG 400 (0–1% w/w) and dried in an oven (40°C). Optimised formulations containing OME and L-arg (1:1, 1:2 and 1:3) were prepared to investigate the stabilisation of the drug. Tensile properties (Texture analysis, TA), physical form (differential scanning calorimetry, DSC; X-ray diffraction, XRD; thermogravimetric analysis, TGA) and surface topography (scanning electron microscopy, SEM) were investigated. Based on the TA results, SA and MET films were chosen for OME loading and stabilisation studies as they showed a good balance between flexibility and toughness. Plasticised MET films were uniform and smooth whilst unplasticised films demonstrated rough lumpy surfaces. SA films prepared from aqueous gels showed some lumps on the surface, whereas SA films prepared from ethanolic gels were smooth and uniform. Drug-loaded gels showed that OME was unstable and therefore required addition of L-arg. The DSC and XRD suggested molecular dispersion of drug within the polymeric matrix. Plasticised (0.5% w/w PEG 400) MET films prepared from ethanolic (20% v/v) gels and containing OME: L-arg 1:2 showed the most ideal characteristics (transparency, ease of peeling and flexibility) and was selected for further investigation
    • …
    corecore