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Hydroxyapatite (HAp) nanomaterials have been synthesized via wet-chemical precipitation route with Ca/P molar ratios of 1.40, 1.60, 1.67, 1.80 and 2.00. These samples have been characterized using scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, Fourier transform-infrared spectroscopy (FT-IR), ultraviolet–visible (UV–vis) diffuse reflectance spectroscopy (DRS), X-ray powder diffraction (XRPD), Rietveld refinement and dielectric spectroscopy. Micrographs from SEM showed that the calcined HAp particles were spherical in shape and they were highly agglomerated. The chemical composition derived from EDX was in good accordance with the theoretical Ca/P ratio. FT-IR spectroscopy revealed the characteristic functional groups: PO43−and OH−. Certain peaks were observed in the diffuse reflectance spectrum which is argued to originate from O2−→ Ca2+and O2−→ P5+charge transfer transitions. Phase analysis showed the existence of single pure HAp (P63/m) only for samples with Ca/P = 1.6 and 1.67. However, HAp with Ca/P = 1.4 had tricalcium phosphate (TCP, Ca3(PO4)2) as the secondary phase, while Ca/P = 1.8 and 2.0 had CaCO3as the secondary phase. Thermograms displayed multiple steps indicating the degradation of secondary phases at higher temperatures. Further, XRD analysis of post-TGA samples revealed that there was no change in the space group symmetry; however, the phase identified was Ca5(PO4)3(CO3)0.01(OH)1.3. The dielectric constant (ε′) and dielectric loss (tanδ) decline with enhancing frequency corresponding well with space-charge and ionic-type polarization behaviour. The ac electrical conductivity enhanced with increasing frequency obeying the Jonscher universal power law.

Disentangling the sources of visual motion in a dynamic scene during self-movement or ego motion is important for autonomous navigation and tracking. In the dynamic image segments of a video frame containing independently moving objects, optic flow relative to the next frame is the sum of the motion fields generated due to camera and object motion. The traditional ego-motion estimation methods assume the scene to be static, and the recent deep learning-based methods do not separate pixel velocities into object- and ego-motion components. We propose a learning-based approach to predict both ego-motion parameters and object-motion field (OMF) from image sequences using a convolutional autoencoder while being robust to variations due to the unconstrained scene depth. This is achieved by: 1) training with continuous ego-motion constraints that allow solving for ego-motion parameters independently of depth and 2) learning a sparsely activated overcomplete ego-motion field (EMF) basis set, which eliminates the irrelevant components in both static and dynamic segments for the task of ego-motion estimation. In order to learn the EMF basis set, we propose a new differentiable sparsity penalty function that approximates the number of nonzero activations in the bottleneck layer of the autoencoder and enforces sparsity more effectively than L1- and L2-norm-based penalties. Unlike the existing direct ego-motion estimation methods, the predicted global EMF can be used to extract OMF directly by comparing it against the optic flow. Compared with the state-of-the-art baselines, the proposed model performs favorably on pixelwise object- and ego-motion estimation tasks when evaluated on real and synthetic data sets of dynamic scenes.

ObjectiveLung hypoplasia associated with congenital diaphragmatic hernia (CDH) results in respiratory insufficiency and pulmonary hypertension after birth. We have investigated whether aerating the lung before removing placental support (physiologically based cord clamping (PBCC)), improves the cardiopulmonary transition in lambs with a CDH.MethodsAt ≈138 days of gestational age, 17 lambs with surgically induced left-sided diaphragmatic hernia (≈d80) were delivered via caesarean section. The umbilical cord was clamped either immediately prior to ventilation onset (immediate cord clamping (ICC); n=6) or after achieving a target tidal volume of 4 mL/kg, with a maximum delay of 10 min (PBCC; n=11). Lambs were ventilated for 120 min and physiological changes recorded.ResultsPulmonary blood flow (PBF) increased following ventilation onset in both groups, but was 19-fold greater in PBCC compared with ICC lambs at cord clamping (19±6.3 vs 1.0±0.5 mL/min/kg, p<0.001). Cerebral tissue oxygenation was higher in PBCC than ICC lambs during the first 10 min after cord clamping (59%±4% vs 30%±5%, p<0.001). PBF was threefold higher (23±4 vs 8±2 mL/min/kg, p=0.01) and pulmonary vascular resistance (PVR) was threefold lower (0.6±0.1 vs 2.2±0.6 mm Hg/(mL/min), p<0.001) in PBCC lambs compared with ICC lambs at 120 min after ventilation onset.ConclusionsCompared with ICC, PBCC prevented the severe asphyxia immediately after birth and resulted in a higher PBF due to a lower PVR, which persisted for at least 120 min after birth in CDH lambs.

ObjectiveInfants with a congenital diaphragmatic hernia (CDH) are at high risk of developing pulmonary hypertension after birth, but little is known of their physiological transition at birth. We aimed to characterise the changes in cardiopulmonary physiology during the neonatal transition in an ovine model of CDH.MethodsA diaphragmatic hernia (DH) was surgically created at 80 days of gestational age (dGA) in 10 fetuses, whereas controls underwent sham surgery (n=6). At 138 dGA, lambs were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood gas values were measured.ResultsDH lambs had lower wet lung-to-body-weight ratio (0.016±0.002vs0.033±0.004), reduced dynamic lung compliance (0.4±0.1mL/cmH2O vs1.2±0.1 mL/cmH2O) and reduced arterial pH (7.11±0.05vs7.26±0.05), compared with controls. While measured pulmonary blood flow (PBF) was lower in DH lambs, after correction for lung weight, PBF was not different between groups (4.05±0.60mL/min/gvs4.29±0.57 mL/min/g). Cerebral tissue oxygen saturation was lower in DH compared with control lambs (55.7±3.5vs67.7%±3.9%).ConclusionsImmediately after birth, DH lambs have small, non-compliant lungs, respiratory acidosis and poor cerebral oxygenation that reflects the clinical phenotype of human CDH. PBF (indexed to lung weight) was similar in DH and control lambs, suggesting that the reduction in PBF associated with CDH is proportional to the degree of lung hypoplasia during the neonatal cardiopulmonary transition.

ObjectiveFetoscopic endoluminal tracheal occlusion (FETO) aims to reverse pulmonary hypoplasia associated with congenital diaphragmatic hernia (CDH) and mitigate the associated respiratory insufficiency and pulmonary hypertension after birth. We aimed to determine whether FETO improves the cardiopulmonary transition at birth in an ovine model of CDH.MethodsIn 12 ovine fetuses with surgically induced diaphragmatic hernia (DH; 80 dGA), an endotracheal balloon was placed tracheoscopically at ≈110 dGA and removed at ≈131 dGA (DH+FETO), while 10 were left untreated (DH). At ≈138 dGA, all lambs (survival at delivery: 67% [DH+FETO], 70% [DH]) were delivered via caesarean section and ventilated for 2 hours. Physiological and ventilation parameters were continuously recorded, and arterial blood-gas values were measured.ResultsCompared with DH, DH+FETO lambs had increased wet lung-to-body-weight ratio (0.031±0.004 vs 0.016±0.002) and dynamic lung compliance (0.7±0.1 vs 0.4±0.1 mL/cmH2O). Pulmonary vascular resistance was lower in DH+FETO lambs (0.44±0.11 vs 1.06±0.17 mm Hg/[mL/min]). However, after correction for lung weight, pulmonary blood flow was not significantly different between the groups (4.19±0.57 vs 4.05±0.60 mL/min/g). Alveolar–arterial difference in oxygen tension was not significantly different between DH+FETO and DH (402±41mm Hg vs 401±45 mm Hg).ConclusionsFETO accelerated lung growth in fetuses with CDH and improved neonatal respiratory function during the cardiopulmonary transition at birth. However, despite improved lung compliance and reduced pulmonary vascular resistance, there were less pronounced benefits for gas exchange during the first 2 hours of life.

The present work focuses on developing carbon-coated lithium iron phosphate (LFP/C) cathode material from economical, high-dense Fe3O4iron precursor resulting in good capacity, high atomic economy, and appreciable tap density for lithium-ion battery (LIB) fabrication. In addition, Fe2O3and Fe were also used as Fe precursor for LFP/C synthesis and the results were compared with Fe3O4-LFP/C. Less gas evolution during heating and high-density precursors resulted in ~20–25 % more atomic efficiency and ~1.5 to 1.8 times higher tap density over FeC2O4-LFP/C. Further, the synthesized materials have been characterized for their phase purity, morphology, and oxidation states using various characterization techniques. Electrochemical studies showed that Fe3O4-LFP/C delivers a high capacity of 137 mAh g−1at 1C when compared with Fe2O3-LFP/C and Fe-LFP/C. Interestingly, Fe3O4-LFP/C retained 83 % capacity after 600 cycles at 1C, illustrating the long cyclic stability. In addition, Fe3O4-LFP/C with the high atomic economy (73 %) and tap density equivalent to the commercially available LFP/C paves the path for affordable LFP synthesis for high-energy density batteries. Hence, the LFP/C developed in this work can be used as a cathode material for high-density electrodes that are appropriate for high-energy applications.