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To develop a physiological data-driven model for early identification of impending cardiac arrest in neonates and infants with cardiac disease hospitalised in the cardiovascular ICU.
We performed a single-institution retrospective cohort study (11 January 2013–16 September 2015) of patients ≤1 year old with cardiac disease who were hospitalised in the cardiovascular ICU at a tertiary care children’s hospital. Demographics and diagnostic codes of cardiac arrest were obtained via the electronic health record. Diagnosis of cardiac arrest was validated by expert clinician review. Minute-to-minute physiological monitoring data were recorded via bedside monitors. A generalized linear model was used to compute a minute by minute risk score. Training and test data sets both included data from patients who did and did not develop cardiac arrest. An optimal risk-score threshold was derived based on the model’s discriminatory capacity for impending arrest versus non-arrest. Model performance measures included sensitivity, specificity, accuracy, likelihood ratios, and post-test probability of arrest.
The final model consisting of multiple clinical parameters was able to identify impending cardiac arrest at least 2 hours prior to the event with an overall accuracy of 75% (sensitivity = 61%, specificity = 80%) and observed an increase in probability of detection of cardiac arrest from a pre-test probability of 9.6% to a post-test probability of 21.2%.
Our findings demonstrate that a predictive model using physiologic monitoring data in neonates and infants with cardiac disease hospitalised in the paediatric cardiovascular ICU can identify impending cardiac arrest on average 17 hours prior to arrest.
Three-dimensional printing (3DP) is becoming a standard manufacturing practice for a variety of biomaterials and biomedical devices. This layer-by-layer methodology provides the ability to fabricate parts from computer-aided design files without the need for part-specific tooling. Three-dimensional printed medical components have transformed the field of medicine through on-demand patient care with specialized treatment such as local, strategically timed drug delivery, and replacement of once-functioning body parts. Not only can 3DP technology provide individualized components, it also allows for advanced medical care, including surgical planning models to aid in training and provide temporary guides during surgical procedures for reinforced clinical success. Despite the advancement in 3DP technology, many challenges remain for forward progress, including sterilization concerns, reliability, and reproducibility. This article offers an overview of biomaterials and biomedical devices derived from metals, ceramics, polymers, and composites that can be three-dimensionally printed, as well as other techniques related to 3DP in medicine, including surgical planning, bioprinting, and drug delivery.
Dust vortices with a void at the centre are reported in this paper. The role of the spatial variation of the plasma potential in the rotation of dust particles is studied in a parallel plate glow discharge plasma. Probe measurements reveal the existence of a local potential minimum in the region of formation of the dust vortex. The minimum in the potential well attracts positively charged ions, while it repels the negatively charged dust particles. Dust rotation is caused by the interplay of the two oppositely directed ion drag and Coulomb forces. The balance between these two forces is found to play a major role in the radial confinement of the dust particles above the cathode surface. Evolution of the dust vortex is studied by increasing the discharge current from 15 to 20 mA. The local minimum of the potential profile is found to coincide with the location of the dust vortex for both values of discharge currents. Additionally, it is found that the size of the dust vortex as well as the void at the centre increases with the discharge current.
The geometry of quadric varieties (hypersurfaces) in finite projective spaces of N dimensions has been studied by Primrose (12) and Ray-Chaudhuri (13). In this paper we study the geometry of another class of varieties, which we call Hermitian varieties and which have many properties analogous to quadrics. Hermitian varieties are defined only for finite projective spaces for which the ground (Galois field) GF(q2) has order q2, where q is the power of a prime. If h is any element of GF(q2), then
= hq is defined to be conjugate to h.
Observational evidence from archival, pre-explosion images, suggests that progenitors of type-IIP SNe (SNe-IIP) have 8 ⩽ MP ⩽ 17 M⊙. However, the post-explosion temporal evolution of the event suggests that even in this mass range, the stellar evolutionary paths, the ensuing mass loss, and the eventual interaction of the supernova shock with the resulting CSM can show considerable diversity. Here we present the results from our program on multi-waveband (mainly optical) observations of SNe-IIP. Mass loss in their progenitors, with a massive and extended H-envelopes, is seen to occur via both strong stellar winds, or episodic mass ejections. Moreover, some type-IIP SNe also show unusually steep decline, characteristic of type-IIL (e.g. SN-IIP 2013ej). Our early and late-time spectrophotometry of these events shows CSM- shock interaction to varying degree among progenitors of comparable mass. Combined with X-ray data, our findings suggest that SNe-IIP progenitors can lose mass via strong stellar winds (e.g. SN2013ej, and SN2014cx), have episodic mass loss (SN2011ja), or have negligible mass loss (SN2012aw, SN2013ab).
A regional cross-country profile of fruit and vegetable (F&V) consumption is lacking in the Eastern Mediterranean Region (EMR). This study examines the prevalence of and differences in consumption of F&V ≥5 times/d among adolescents in eleven EMR countries, and describes differences in the proportions of taking F&V ≥5 times/d by sex, age and BMI. The study included 26 328 school adolescents (13–15 years) with complete data on consumption of F&V, age, sex, weight and height taken from the Global School-based Student Health Survey conducted in the EMR between 2005 and 2009. Overall, only 19·4 % of adolescents reported consuming F&V ≥5 times/d. The highest prevalence was reported in Djibouti (40·4 %) and the lowest was reported in Pakistan (10·0 %). Statistically significant differences in prevalence were observed across countries (P<0·05). With the exception of Oman, Libya and Djibouti, significantly more males than females ate F&V ≥5 times/d. The proportion of students consuming F&V ≥5 times/d also varied significantly in all countries based on BMI (P<0·0001), with students within normal BMI having the highest frequency. A negative trend was observed between age and intake of F&V ≥5 times/d in most of the eleven EMR countries except Jordan, Djibouti and Morocco. The prevalence of adequate intake of F&V is low in the eleven EMR countries. There is a need for interventions to increase the prevalence of adolescents consuming F&V ≥5 times/d. Interventions should take into consideration the psychosocial, environmental and socio-environmental factors influencing F&V intake within countries.
Regional cross-country profile of fruit and vegetable (F&V) consumption is lacking in the Eastern Mediterranean Region (EMR). This study examines the prevalence and differences of consuming F&V ≥5 times/d among adolescents in eleven EMR countries, and also describes differences in the proportions of taking F&V ≥5 times/d by sex, age and BMI. The study included 26 328 school adolescents (13–15 years) with complete data on consumption of F&V, age, sex, weight and height taken from the Global School-based Student Health Survey conducted in the EMR between 2005 and 2009. Overall, only 19·4 % of adolescents reported consuming F&V ≥5 times/d. The highest prevalence was reported in Djibouti (40·4 %) and the lowest was reported in Pakistan (10·0 %). Statistically significant differences in prevalence were observed across countries (P<0·05). With the exception of Oman, Libya and Djibouti, significantly more males than females ate F&V ≥5 times/d. Proportion of students consuming F&V ≥5 times/d also varied significantly in all counties based on BMI (P<0·0001), with students within normal BMI having the highest frequency. A negative trend was observed between age and the prevalence of taking F&V ≥5 times/d in most of the eleven EMR countries but Jordan, Djibouti and Morocco. The prevalence of adequate intake of F&V was low in the eleven EMR countries. There is a need for interventions to increase the prevalence of adolescents consuming F&V ≥5 times/d. Interventions should take into consideration psychosocial, environmental and socio-environmental factors influencing F&V intake within countries.
The development of efficient large-area organic light emitting diodes (OLED) requires reliable and easily processable charge generation layers (CGL) with low excess voltage drop and high optical transparency. OVPD offers the advantage of a precise control of layer morphology, composition and thickness and is a powerful method for the deposition of advanced OLED designs. In this work, electrical doping of organic semiconductors using OVPD is investigated and applied to stacked OLED utilizing inorganic/organic CGL. The organic p-type dopant NDP-9 of Novaled GmbH is used for doping the hole transport material N,N‘-diphenyl-N,N‘-bis(1-naphthylphenyl)-1,1‘-biphenyl-4,4‘-diamine (α-NPD) in an AIXTRON OVPD tool. A doping concentration of 8 vol.% of NDP-9 in α-NPD is found optimal for hole injection as well as conductivity. This dopant concentration was employed in CGL with the structure: electron transport material/LiF/Al/α-NPD:8 vol.% NDP-9. External quantum efficiencies (EQE) of 15%, 35% and 50% and luminous efficiencies of 37 lm/W, 45 lm/W and 45 lm/W at 1000 cd/m2 are demonstrated for single, double- and triple-unit green phosphorescent OLED, respectively.
The light out-coupling potential of introducing a semitransparent Ag layer between the anode and the organic layer stack of monochrome bottom-emitting organic light emitting diodes (OLED) is examined. Red and green phosphorescent as well as deep-blue fluorescent resonant-cavity OLED (RC-OLED) comprising a semitransparent Ag layer are processed by means of organic vapor phase deposition (OVPD). An enhancement of the luminous efficiency of up to 81% can be observed.
The impressive efficiency enhancement can be explained by a reduced formation of substrate modes in combination with a strong narrowing of the emission spectrum leading to an increased true luminous efficiency.
Elevated striatal dopamine synthesis capacity is thought to be fundamental to the pathophysiology of schizophrenia and has also been reported in people at risk of psychosis. It is therefore unclear if striatal hyperdopaminergia is a vulnerability marker for schizophrenia, or a state feature related to the psychosis itself. Relatives of patients with schizophrenia are themselves at increased risk of developing the condition. In this study we examined striatal dopamine synthesis capacity in both members of twin pairs discordant for schizophrenia.
In vivo striatal dopamine synthesis capacity was examined using fluorine-18-l-dihydroxyphenylalanine (18F-DOPA) positron emission tomography (PET) scans in seven twin pairs discordant for schizophrenia and in a control sample of 10 healthy control twin pairs.
Striatal 18F-DOPA uptake was not elevated in the unaffected co-twins of patients with schizophrenia (p=0.65) or indeed in the twins with schizophrenia (p=0.89) compared to the control group. Levels of psychotic symptoms were low in the patients with schizophrenia who were in general stable [mean (s.d.) Positive and Negative Syndrome Scale (PANSS) total=56.8 (25.5)] whereas the unaffected co-twins were largely asymptomatic.
Striatal dopamine synthesis capacity is not elevated in symptom-free individuals at genetic risk of schizophrenia, or in well-treated stable patients with chronic schizophrenia. These findings suggest that striatal hyperdopaminergia is not a vulnerability marker for schizophrenia.
We present here new information on the effect of irradiation temperature on the strength and mechanical anisotropy of Zr-2.5%Nb CANDU pressure tube material. Polished samples aligned normal to the transverse (TN), axial (AN) and radial (RN) directions of the pressure tube were irradiated at 300°C with 8.5 MeV Zr+ ions to assess the effect of concurrent thermal annealing of the irradiation damage. Constant-load micro-indentation creep tests were performed at 25°C at indentation depths from 0.1 to 2.0 μm on the ion irradiated samples.
The increase in the initial indentation stress with increasing levels of Zr+ ion irradiation at 300°C was lower than that reported earlier for similar samples exposed to Zr+ irradiation at 25°C. While the anisotropy of the indentation stress decreased significantly with Zr+ ion irradiation, the level of the decrease was reduced when the irradiation was performed at 300oC compared to 25oC. The apparent activation energy ΔG0 of the obstacles that limit the rate of dislocation glide during indentation creep did not change with indentation direction but did increase with increasing levels of Zr+ ion damage. The values of ΔG0 were, again, lower for samples that were irradiated at 300°C than for those irradiated at 25oC.
The observed differences in the magnitude of, and the anisotropy of, the initial indentation stress and also the decrease in the apparent activation energy of the indentation creep process of Zr-2.5%Nb samples irradiated with Zr+ ions at 300oC compared to those irradiated at 25oC indicate the effect that concurrent thermal annealing has on the accumulation of irradiation damage. The effect of irradiation temperature on reducing the degree of, and the strength of, irradiation induced crystallographic damage must therefore be considered when predicting the strength and thermal creep behaviour of irradiated nuclear materials.
This paper reviews the several powder processing techniques that have been applied to the fabrication of both monolithic aluminides and their composites. Attention is given to the active research at Rensselaer on reactive sintering and reactive hot isostatic pressing of elemental powders, hot pressing of prealloyed powders, and molding of powder-fiber-binder slurries. The application of one or more of these techniques to the following monolithic intermetallics is described: NiAl, Ni3Al, TiAl, NbAl3, Ta2Al, and TaAl3. Progress has occurred in fabrication of dense compacts, including some composites, from these aluminides.
Composites containing alumina fibers in Ni3Al+B or an Ni3Al, Cr+B alloy have been prepared by several powder metallurgical processes. Tensile tests reveal some ductility and a mixed fracture mode in both monolithic and composite alloys. Previous reports of inadequate bonding of fibers in Ni3 Al+B have been confirmed.
Exposure of GaAs and AlGaAs to a hydrogen plasma has been shown to result in a significant change in the electrical and optical properties. The changes are related to the electrical deactivation of the deep and shallow impurities by hydrogenation. Spectroscopic and electrical measurements have shown that Si donors and C acceptors in high purity GaAs can be passivated by hydrogenation. Hydrogenation of p-type GaAs and AlGaAs has resulted in highly resistive material. SiO2 was found to be a suitable mask for the hydrogenation process. Single and multiple stripe geometry lasers have been fabricated by properly masking the laser structure. The lasers produced using the hydrogenation process have low threshold currents and are capable of cw room temperature operation.
In this paper we have studied the dia and paramagentic susceptibilities of the holes in ultrathin films of magnetic materials in the presence of a parallel magentic field on the basis of a newly derived dispersion law for such systems. The numerical computations are performed taking Hg1-xMnx Te and Cd1-xMnx Se as examples. Both the susceptibilities increses with decreasing doping and film thickness respectively. It is important to note that not only the paramagnetic-to-diamagnetic susceptibility ratio for the present case deviates from (1/3) in conventional semiconductors, but also that is a critical region, where quenching of the diamagnetic occurs. The theoretical analysis is in agreement with the experimental datas as given elsewhere.