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The ventricular assist device is being increasingly used as a “bridge-to-transplant” option in children with heart failure who have failed medical management. Care for this medically complex population must be optimised, including through concomitant pharmacotherapy. Pharmacokinetic/pharmacodynamic alterations affecting pharmacotherapy are increasingly discovered in children supported with extracorporeal membrane oxygenation, another form of mechanical circulatory support. Similarities between extracorporeal membrane oxygenation and ventricular assist devices support the hypothesis that similar alterations may exist in ventricular assist device-supported patients. We conducted a literature review to assess the current data available on pharmacokinetics/pharmacodynamics in children with ventricular assist devices. We found two adult and no paediatric pharmacokinetic/pharmacodynamic studies in ventricular assist device-supported patients. While mechanisms may be partially extrapolated from children supported with extracorporeal membrane oxygenation, dedicated investigation of the paediatric ventricular assist device population is crucial given the inherent differences between the two forms of mechanical circulatory support, and pathophysiology that is unique to these patients. Commonly used drugs such as anticoagulants and antibiotics have narrow therapeutic windows with devastating consequences if under-dosed or over-dosed. Clinical studies are urgently needed to improve outcomes and maximise the potential of ventricular assist devices in this vulnerable population.
A key to long-term sustainable enhancement of viable livestock production is the introduction of genetic traits that ensure that fertility and meat quality characteristics are compatible with farming environments and market needs. For example, the sheep industry could benefit if daughters of hill-breed ewes were of a crossbred genotype that enhances both carcass characteristics and fertility traits. Use of sires that confer better conformation is an option but does not significantly boost prolificacy. Introduction of the ‘Inverdale’ fecundity gene could change this. On a flock basis in the Romney breed, mean ovulation is increased by 1.0 and litter size by 0.6 in adult ewes carrying a single copy of this gene (designated as FecXI because it is on the X chromosome; Davis et al. 1992). Carrier males transmit it to all of their female offspring, these being heterozygous carriers of the gene unless it also is maternally inherited. In the latter instance, young would be infertile the homozygous genotype confers an undesirable ‘streak ovary’ phenotype. Although a number of sheep breeds world-wide exhibit significant ‘single gene’ effects on ovulation and litter size (Montgomery et al. 2001), Scottish hill sheep breeds show no evidence of this. Consequently, all ewe lambs generated by crossing these hill ewes with a ram carrying the Inverdale gene should be heterozygous. To ascertain whether such animals exhibit enhanced fecundity, an on-farm study investigated ovulation incidence in cyclic ewe lambs born to Cheviot or Scottish Blackface ewes that had been bred to Texel rams carrying a single copy of the ‘Inverdale’ gene.
This study aimed to estimate the prevalence and risk factors for hepatitis C virus (HCV) infection in Mexican Americans living in South Texas. We tested plasma for the presence of HCV antibody from the Cameron County Hispanic Cohort (CCHC), a randomized, population-based cohort in an economically disadvantaged Mexican American community on the United States/Mexico border with high rates of chronic disease. A weighted prevalence of HCV antibody of 2·3% [n = 1131, 95% confidence interval (CI) 1·2–3·4] was found. Participants with diabetes had low rates of HCV antibody (0·4%, 95% CI 0·0–0·9) and logistic regression revealed a statistically significant negative association between HCV and diabetes (OR 0·20, 95% CI 0·05–0·77) after adjusting for sociodemographic and clinical factors. This conflicts with reported positive associations of diabetes and HCV infection. No classic risk factors were identified, but important differences between genders emerged in analysis. This population-based study of HCV in Mexican Americans suggests that national studies do not adequately describe the epidemiology of HCV in this border community and that unique risk factors may be involved.
Group B streptococcus (GBS) is an increasing cause of disease in adults. We present long-term trends in incidence of overall infections and identify characteristics of patients with GBS cellulitis, bone and joint infections. Active, population-based surveillance was conducted from 1995–2012 in three California counties and the data were analysed retrospectively. All cases had isolation of GBS from a normally sterile site. Cases of cellulitis were classified based on clinical diagnosis. GBS bone or joint infection was defined as isolation of GBS from a bone or joint or a diagnosis of osteomyelitis or septic arthritis. Medical charts were reviewed for demographic and clinical information. There were 3917 cases of GBS; the incidence of disease increased from 5·8 to 8·3 cases/100 000 persons (P < 0·001) from 1995 to 2012. In adults aged ⩾40 years, the overall incidence of GBS increased from 8·5 to 14·2 cases/100 000 (P < 0·001) persons during the study period. The incidence of cellulitis increased from 1·6 to 3·8 cases/100 000 (P < 0·001), bone infection increased from 0·7 to 2·6 cases/100 000 (P < 0·001), and the incidence of joint infection remained approximately constant at an average rate of 1·0 case/100 000. The highest incidence rates were observed in men, persons aged ⩾80 years, non-Hispanic blacks and Hispanics. Diabetes was the most common underlying condition (51·2% cellulitis cases, 76·3% bone infections, 29·8% joint infections).
An epitaxial shell of cadmium sulphide is grown on lead sulphide quantum dots in order to reduce the concentration of surface defects. Thin solid films of these core/shell materials are found to have low carrier concentrations due to effective surface passivation which reduces the number of dangling bonds. In this paper PbS/CdS is used as a quasi-intrinsic layer in p-i-n photovoltaic devices where PbS acts as the p-layer and ZnO the n-layer. By studying different permutations of these layers and the degree of PbS p-type doping by annealing we optimise fill factor and open-circuit voltage.
Coronal Multi-channel Polarimeter (CoMP-S), developed by HAO/NCAR, has been introduced to regular operation at the Lomnicky Peak Observatory (High Tatras in northern Slovakia, 2633 m a.s.l.) of the Astronomical Institute of Slovak Academy of Sciences. We present here the technical parameters of the current version of the instrument and its potential for observations of prominences in the visual and near-IR spectral regions. The first results derived from observations of prominences in the Hα emission line taken during a coordinated observing campaign of several instruments in October 2012 are shown here.
We introduced a long-term care facility (LTCF) infectious disease (ID) consultation service (LID service) that provides on-site consultations to residents of a Veterans Affairs (VA) LTCF. We determined the impact of the LID service on antimicrobial use and Clostridium difficile infections at the LTCF.
A 160-bed VA LTCF.
Systemic antimicrobial use and positive C. difficile tests at the LTCF were compared for the 36 months before and the 18 months after the initiation of the ID consultation service through segmented regression analysis of an interrupted time series.
Relative to that in the preintervention period, total systemic antibiotic administration decreased by 30% (P<.001), with significant reductions in both oral (32%; P<.001) and intravenous (25%; P = .008) agents. The greatest reductions were seen for tetracyclines (64%; P<.001), clindamycin (61%; P<.001), sulfamethoxazole/trimethoprim (38%; P<.001), fluoroquinolones (38%; P<.001), and β lactam/β-lactamase inhibitor combinations (28%; P<.001). The rate of positive C. difficile tests at the LTCF declined in the postintervention period relative to preintervention rates (P = .04).
Implementation of an LTCF ID service led to a significant reduction in total antimicrobial use. Bringing providers with ID expertise to the LTCF represents a new and effective means to achieve antimicrobial stewardship.
The results of our recent research on the ohmic contact formation mechanism in furnace alloyed Au/Te/Au/GaAs contacts are summarized, and preliminary Raman measurements on annealed Ge/Pd/GaAs structures are presented. The data and those reported in literature on the AuGe- and Ge/Pd- GaAs systems are argued to be more in agreement with the graded crystalline heterojunction concept (the formation of n+-Ge/GaAs, n+Ga2Te3/GaAs junctions) than with the doping model (the formation of n+-GaAs).
This paper describes the electrical and physical characteristics of ultrathin Jet Vapor Deposited (JVD) Silicon Oxynitride films. Capacitance-Voltage measurements indicate an equivalent oxide thickness (EOT) of less than 2 nm, taking into account the quantum-mechanical correction. These films have leakage currents almost two orders of magnitude lower than thermal oxide of the same equivalent thickness. Measurements on NMOSFETs with 0.15 μm of channel length demonstrate excellent electrical properties, including high drive currents (∼0.5 mA/μm @ Vd=Vg–Vt=l.5 V), low sub-threshold swings (∼72 mV/decade), and high transconductance (∼0.36 mS/μm @ Vd=1.5 V). These films were also analyzed using a variety of physicochemical methods, including Total X-ray Fluorescence (TXRF), Atomic Force Microscopy (AFM), Nuclear Reaction Analysis (NRA), Low Energy (500 eV) Secondary Ion Mass Spectrometry (SIMS), and Transmission Electron Microscopy (TEM). Surface metal concentrations of less than 1011 atoms/cm2 were measured from the TXRF analysis. The microroughness values for these films varied between 0.15 – 0.17 nm as measured by AFM. Low energy (500 eV) SIMS and NRA indicate high [N] near the top as well as throughout the bulk of the film, and a significant amount of [O] near the top of the film. High Resolution TEM pictures show a very uniform film with a physical thickness of 2.8 ± 0.1 nM, which yields an effective dielectric constant of 5.5, consistent with these types of oxynitride films.
An aspect which has hindered the development of ferroelectric memories is dielectric fatigue and to resolve this conducting oxides are promising candidates as an electrode material for lead zirconate titanate thin films. In this work ferroelectric films have been grown by pulsed laser deposition on ruthenium oxide electrodes. The phase distribution, microstructure and the effect of subsequent heat treatment have been studied by grazing angle X ray diffraction and electron microscopy; the results and implications for use of RuO2 as the bottom electrode during vapour phase deposition are discussed.
A design-of-experiments methodology was implemented to assess the commercial equipment viability to fabricate the high-K dielectrics Ta2O5, TiO2 and BST (70/30 and 50/50 compositions) for use as gate dielectrics. The high-K dielectrics were annealed in 100% or 10% O2 for different times and temperatures in conjunction with a previously prepared NH3 nitrided or 14N implanted silicon surface. Five metal electrode configurations—Ta, TaN, W, WN and TiN—were concurrently examined. Three additional silicon surface configurations were explored in conjunction with a more in-depth set of time and temperature anneals for Ta2O5. Electrical characterization of capacitors fabricated with the above high-K gate dielectrics, as well as SIMS and TEM analysis, indicate that the post high-K deposition annealing temperature was the most significant variable impacting the leakage current density, although there was minimal influence on the capacitance. Further studies are required, however, to clarify the physical mechanisms underlying the electrical data presented.
Streptococcus pneumoniae is a common cause of community-acquired pneumonia (CAP) but existing diagnostic tools have limited sensitivity and specificity. We enrolled adults undergoing chest radiography at three Indian Health Service clinics in the Southwestern United States and collected acute and convalescent serum for measurement of PsaA and PspA titres and urine for pneumococcal antigen detection. Blood and sputum cultures were obtained at the discretion of treating physicians. We compared findings in clinical and radiographic CAP patients to those in controls without CAP. Urine antigen testing showed the largest differential between CAP patients and controls (clinical CAP 13%, radiographic CAP 17%, control groups 2%). Serological results were mixed, with significant differences between CAP patients and controls for some, but not all changes in titre. Based on urine antigen and blood culture results, we estimated that 11% of clinical and 15% of radiographic CAP cases were due to pneumococcus in this population.
Few population-based studies have investigated the epidemiology of adult community-acquired pneumonia (CAP). We aimed to determine the incidence of CAP in a population at high-risk for pneumococcal disease and to evaluate a standardized method for interpreting chest radiographs adapted from the World Health Organization paediatric chest radiograph interpretation guidelines. We reviewed radiology records at the two healthcare facilities serving the White Mountain Apache tribe to identify possible pneumonia cases ⩾40 years of age. We categorized patients with clinical criteria and a physician diagnosis of pneumonia as clinical CAP and those with clinical criteria and an acute infiltrate as radiographic CAP. We identified 100 (27/1000 person-years) and 60 (16/1000 person-years) episodes of clinical and radiographic CAP, respectively. The incidence of CAP increased with age. Both radiographic and clinical CAP were serious illnesses with more than half of patients hospitalized. Our case definitions and methods may be useful for comparing data across studies and conducting vaccine trials.
An allometric scaling approach has been used to calculate biological half-lives of elimination (TB1/2) and concentration factors (CF) for radionuclides in marine biota. Power functions of organism mass are fitted to a biokinetic database for plankton, seaweed, fish, crustaceans and molluscs, using data generated by us, in combination with reviewed data. Scaling of the CF to M-0.26 ± 0.09 is observed, compatible at ±1σ with metabolic theory predictions that metabolism scales to M0.75. We also observe scaling of TB1/2 to M+0.16 ± 0.03, within the previously reported range +0.15 to +0.30 for biota from various environments and, at < ± 3σ, slightly outside turnover rate scaling predictions to M-0.25. The elements for which the CF scales better allometrically are particle seeking, mainly lanthanides and actinides. Association of the independent term of the allometric power function a with the sediment-water partition coefficient Kd is strongest for these elements, possibly through binding to biological/organic matter. The findings from this study are relevant to extend the range of applicability of our biota dose assessment methodologies where data gaps in transfer exist.