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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.
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.
In previous work, a platform was developed for testing computer-vision algorithms for robotic planetary exploration. This platform consisted of a digital video camera connected to a wearable computer for real-time processing of images at geological and astrobiological field sites. The real-time processing included image segmentation and the generation of interest points based upon uncommonness in the segmentation maps. Also in previous work, this platform for testing computer-vision algorithms has been ported to a more ergonomic alternative platform, consisting of a phone camera connected via the Global System for Mobile Communications (GSM) network to a remote-server computer. The wearable-computer platform has been tested at geological and astrobiological field sites in Spain (Rivas Vaciamadrid and Riba de Santiuste), and the phone camera has been tested at a geological field site in Malta. In this work, we (i) apply a Hopfield neural-network algorithm for novelty detection based upon colour, (ii) integrate a field-capable digital microscope on the wearable computer platform, (iii) test this novelty detection with the digital microscope at Rivas Vaciamadrid, (iv) develop a Bluetooth communication mode for the phone-camera platform, in order to allow access to a mobile processing computer at the field sites, and (v) test the novelty detection on the Bluetooth-enabled phone camera connected to a netbook computer at the Mars Desert Research Station in Utah. This systems engineering and field testing have together allowed us to develop a real-time computer-vision system that is capable, for example, of identifying lichens as novel within a series of images acquired in semi-arid desert environments. We acquired sequences of images of geologic outcrops in Utah and Spain consisting of various rock types and colours to test this algorithm. The algorithm robustly recognized previously observed units by their colour, while requiring only a single image or a few images to learn colours as familiar, demonstrating its fast learning capability.
Stimulated Brillouin scattering of an electromagnetic wave is investigated analytically in a dissipative magnetized plasma in the presence of negative ions. With an increase in the number of negative ions (maintaining quasi-neutrality), it is found that the growth rate of ion-acoustic waves decreases very slowly up to 50% concentration (i.e. half of the total ionic contribution) of negative ions. Further increase in the number density of negative ions beyond 50% results in a sharp fall in growth rate.
The stimulated Brillouin scattering of Alfvén waves is studied in low-density plasmas. It is shown that ion-sound oscillations may be excited by this mechanism under suitable ionospheric conditions and that the presence of negative ions reduces the probability of such excitations.
A systematic and comprehensive study of linear and nonlinear analyses of the propagation of low-frequency modes in two-ion-species plasma has been made. Two new non-propagating modes on different ion time-scales are reported. These modes are excited by nonlinear coupling with the external pump. The threshold field of the pump and the growth rates of the various modes above the threshold are also calculated. A comparison of the results with those of single-ion-species plasma shows that the non-propagating mode on the fast ion time-scale excites the oscillating two-stream instability. In addition, the mode corresponding to ωr = 0 on the slow ion time-scale becomes important nonlinearly and excites a new type of instability. It is interesting to note that the threshold electric fields excitation of these instabilities are the same.
Background: Depression in the elderly is a common and disabling condition. The aim of the study was to evaluate the sensitivity and specificity of a two-question screen to identify depression and common mental disorders in the elderly.
Method: Residents of a ward in the town of Vellore were identified by a door-to-door survey from which 204 subjects aged over 60 years were selected for the study by systematic random sampling. They were screened using the two-question screen. The Revised Clinical Interview Schedule (CIS-R) was employed to confirm the diagnosis.
Results: The prevalence of depression and common mental disorder, using the CIS-R standard, was found to be 31.5%. The two-question screen has a sensitivity of 93.8% and specificity of 48.2%.
Conclusions: The high sensitivity of the two-question screen makes it a useful screening method which can be employed by health workers in the field.