- Electrically polarized TiO2 nanotubes on Ti implants to enhance early-stage osseointegration. [Journal Article]
- ABActa Biomater 2019 Jul 18
- Ti is characteristically bioinert and is supplemented with modifications in surface topography and chemistry to find use in biomedical applications. The aim of this study is to understand the effects…
Ti is characteristically bioinert and is supplemented with modifications in surface topography and chemistry to find use in biomedical applications. The aim of this study is to understand the effects of surface charge on TiO2 nanotubes (TNT) on Ti implants towards early stage osseointegration. We hypothesize that charge storage on TNT will improve bioactivity and enhance early-stage osseointegration in vivo. Commercially pure Ti surface was altered by growing TNT via anodic oxidation followed by the introduction of surface charge through electrothermal polarization to form bioelectret. Our results indicate a stored charge of 37.15±14 mC/cm2 for TNT surfaces. The polarized TNT (TNT-Ps) samples did not show any charge leakage up to 18 months, and improved wettability with a measured contact angle less than 1°. No cellular toxicity through osteoblast proliferation and differentiation in vitro were shown by the TNT-Ps. Enhanced new bone formation at 5 weeks post-implantation for the TNT-Ps in contrast to TNTs was observed in vivo. Histomorphometric analyses show ∼40% increase in mineralized bone formation around the TNT-P implants than the TNTs at 5 weeks, which is indicative of accelerated bone remodeling cycle. These results show that stored surface charge on TiO2 nanotubes helped to accelerate bone healing due to early-stage osseointegration in vivo. STATEMENT OF SIGNIFICANCE: To improve surface bioactivity of metallic biomaterials, various approaches have been proposed and implemented. Among them, stored surface charge has been explored to enhance biological responses for hydroxyapatite ceramics where charged surfaces show favorable bone tissue ingrowth. However, surface charge effects have not yet been explored as a way to mitigate bio-inertness of titanium. This study intends to understand novel integration of bioactive titania-nanotubes and charge storage as surface modification for titanium implants. Our results show excellent biological response due to surface charge on titania-nanotubes offering possibilities of faster healing particularly for patients with compromised bone health.
- AMOT130/YAP pathway in topography-induced BMSC osteoblastic differentiation. [Journal Article]
- CSColloids Surf B Biointerfaces 2019 Jun 28; 182:110332
- Micro/nano-topography (MNT) is an important variable affecting osseointegration of bone biomaterials, but the underlying mechanisms are not fully understood. We probed the role of a AMOT130/YAP pathw…
Micro/nano-topography (MNT) is an important variable affecting osseointegration of bone biomaterials, but the underlying mechanisms are not fully understood. We probed the role of a AMOT130/YAP pathway in osteoblastic differentiation of bone marrow mesenchymal stems cultured on titanium (Ti) carrying MNTs. Ti surfaces with two well-defined MNTs (TiO2 nanotubes of different diameters and wall thicknesses) were prepared by anodization. Rat BMSCs were cultured on flat Ti and Ti surfaces carrying MNTs, and cell behaviors (i.e., morphology, F-actin development, osteoblastic differentiation, YAP localization) were studied. Ti surfaces carrying MNTs increased F-actin formation, osteoblastic gene expression, and protein AMOT130 production in BMSCs (all vs. flat Ti), and the surface carrying larger nantubes was more effective, confirming osteoblastic differentiation induced by MNTs. Elevation of the AMOT130 level (by inhibiting its degradation) increased the osteoblastic gene expression, F-actin formation, and nuclear localization of YAP. These show that, AMOT130/YAP is an important pathway mediating the translation of MNT signals to BMSC osteoblastic commitment, likely via the cascade: AMOT130 promotion of F-actin formation, increased YAP nuclear import, and activation of osteoblastic gene expression.
- Meta-analysis of Natural, Unnatural, and Cause-Specific Mortality Rates Following Discharge From Inpatient Psychiatric Facilities. [Journal Article]
- APActa Psychiatr Scand 2019 Jul 20
- CONCLUSIONS: Suicide may be the largest single cause of death in the short term after discharge from inpatient psychiatric facilities but vascular disease is the major cause of mortality in the medium and long term. This article is protected by copyright. All rights reserved.
- Molecular adsorption and dissociation of CO2 on TiO2 anatase (001) activated by oxygen vacancies. [Journal Article]
- JMJ Mol Model 2019 Jul 19; 25(8):231
- A study on the influence of oxygen vacancies on the anatase (001) surface on the CO2 adsorption process is presented. For its realization, density functional theory (DFT) was used under the Perdew-Bu…
A study on the influence of oxygen vacancies on the anatase (001) surface on the CO2 adsorption process is presented. For its realization, density functional theory (DFT) was used under the Perdew-Burke-Ernzerhof (PBE) generalized gradient and the spin-polarized approximations. Hubbard-U corrections and van der Waals interactions were also included. Three different types of oxygen vacancies were investigated at different sites on the anatase (001) surface; the formation energies in each case were 67.05, 113.84, and 93.16 kcal/mol, respectively. We identified a type of oxygen vacancy that could favor both the CO2 adsorption and dissociation. The differences on CO2 adsorption properties are due to electronic and structural causes, such as midgap states (Ti3+ polarons species) and changes in the structural properties on the TiO2 surface, generated upon the introduction of an oxygen vacancy. It is concluded that oxygen vacancies can play an important role in both CO2 adsorption and dissociation.
- Dopey1-Mon2 complex binds to dual-lipids and recruits kinesin-1 for membrane trafficking. [Journal Article]
- NCNat Commun 2019 Jul 19; 10(1):3218
- Proteins are transported among eukaryotic organelles along the cytoskeleton in membrane carriers. The mechanism regarding the motility of carriers and the positioning of organelles is a fundamental q…
Proteins are transported among eukaryotic organelles along the cytoskeleton in membrane carriers. The mechanism regarding the motility of carriers and the positioning of organelles is a fundamental question in cell biology that remains incompletely understood. Here, we find that Dopey1 and Mon2 assemble into a complex and localize to the Golgi, endolysosome and endoplasmic reticulum exit site. The Golgi localization of Dopey1 and Mon2 requires their binding to phosphatidylinositol-4-phosphate and phosphatidic acid, respectively, two lipids known for the biogenesis of membrane carriers and the specification of organelle identities. The N-terminus of Dopey1 further interacts with kinesin-1, a plus-end or centrifugal-direction microtubule motor. Dopey1-Mon2 complex functions as a dual-lipid-regulated cargo-adaptor to recruit kinesin-1 to secretory and endocytic organelles or membrane carriers for centrifugally biased bidirectional transport. Dopey1-Mon2 complex therefore provides an important missing link to coordinate the budding of a membrane carrier and subsequent bidirectional transport along the microtubule.
- Single-Board-Computer Clusters for Cloudlet Computing in Internet of Things. [Journal Article]
- SSensors (Basel) 2019 Jul 09; 19(13)
- The number of connected sensors and devices is expected to increase to billions in the near future. However, centralised cloud-computing data centres present various challenges to meet the requiremen…
The number of connected sensors and devices is expected to increase to billions in the near future. However, centralised cloud-computing data centres present various challenges to meet the requirements inherent to Internet of Things (IoT) workloads, such as low latency, high throughput and bandwidth constraints. Edge computing is becoming the standard computing paradigm for latency-sensitive real-time IoT workloads, since it addresses the aforementioned limitations related to centralised cloud-computing models. Such a paradigm relies on bringing computation close to the source of data, which presents serious operational challenges for large-scale cloud-computing providers. In this work, we present an architecture composed of low-cost Single-Board-Computer clusters near to data sources, and centralised cloud-computing data centres. The proposed cost-efficient model may be employed as an alternative to fog computing to meet real-time IoT workload requirements while keeping scalability. We include an extensive empirical analysis to assess the suitability of single-board-computer clusters as cost-effective edge-computing micro data centres. Additionally, we compare the proposed architecture with traditional cloudlet and cloud architectures, and evaluate them through extensive simulation. We finally show that acquisition costs can be drastically reduced while keeping performance levels in data-intensive IoT use cases.
- Development of Polymer Blend Electrolyte Membranes Based on Chitosan: Dextran with High Ion Transport Properties for EDLC Application. [Journal Article]
- IJInt J Mol Sci 2019 Jul 09; 20(13)
- Solid polymer blend electrolyte membranes (SPBEM) composed of chitosan and dextran with the incorporation of various amounts of lithium perchlorate (LiClO4) were synthesized. The complexation of the …
Solid polymer blend electrolyte membranes (SPBEM) composed of chitosan and dextran with the incorporation of various amounts of lithium perchlorate (LiClO4) were synthesized. The complexation of the polymer blend electrolytes with the salt was examined using FTIR spectroscopy and X-ray diffraction (XRD). The morphology of the SPBEs was also investigated using field emission scanning electron microscopy (FESEM). The ion transport behavior of the membrane films was measured using impedance spectroscopy. The membrane with highest LiClO4 content was found to exhibit the highest conductivity of 5.16 × 10-3 S/cm. Ionic (ti) and electronic (te) transference numbers for the highest conducting electrolyte were found to be 0.98 and 0.02, respectively. Electrochemical stability was estimated from linear sweep voltammetry and found to be up to ~2.3V for the Li+ ion conducting electrolyte. The only existence of electrical double charging at the surface of electrodes was evidenced from the absence of peaks in cyclic voltammetry (CV) plot. The discharge slope was observed to be almost linear, confirming the capacitive behavior of the EDLC. The performance of synthesized EDLC was studied using CV and charge-discharge techniques. The highest specific capacitance was achieved to be 8.7 F·g-1 at 20th cycle. The efficiency (η) was observed to be at 92.8% and remained constant at 92.0% up to 100 cycles. The EDLC was considered to have a reasonable electrode-electrolyte contact, in which η exceeds 90.0%. It was determined that equivalent series resistance (Resr) is quite low and varies from 150 to 180 Ω over the 100 cycles. Energy density (Ed) was found to be 1.21 Wh·kg-1 at the 1st cycle and then remained stable at 0.86 Wh·kg-1 up to 100 cycles. The interesting observation is that the value of Pd increases back to 685 W·kg-1 up to 80 cycles.
- Video Activity Recognition: State-of-the-Art. [Review]
- SSensors (Basel) 2019 Jul 18; 19(14)
- Video activity recognition, although being an emerging task, has been the subject of important research efforts due to the importance of its everyday applications. Surveillance by video cameras could…
Video activity recognition, although being an emerging task, has been the subject of important research efforts due to the importance of its everyday applications. Surveillance by video cameras could benefit greatly by advances in this field. In the area of robotics, the tasks of autonomous navigation or social interaction could also take advantage of the knowledge extracted from live video recording. The aim of this paper is to survey the state-of-the-art techniques for video activity recognition while at the same time mentioning other techniques used for the same task that the research community has known for several years. For each of the analyzed methods, its contribution over previous works and the proposed approach performance are discussed.
- Prediction of suspicious thyroid nodule using artificial neural network based on radiofrequency ultrasound and conventional ultrasound: A preliminary study. [Journal Article]
- UUltrasonics 2019 Jun 24; 99:105951
- This study explored the use of backscattered radiofrequency ultrasound signals combined with artificial neural network (ANN) technology to differentiate benign and malignant thyroid nodules, in compa…
This study explored the use of backscattered radiofrequency ultrasound signals combined with artificial neural network (ANN) technology to differentiate benign and malignant thyroid nodules, in comparison with conventional ultrasound techniques. The proposed method uses the gray level co-occurrence matrix algorithm and principal component analysis to identify principal characteristics for use as inputs in the ANN. The dataset consisted of 131 ultrasound images, of which 59 were benign and 72 were malignant, as determined by subsequent surgeries. The nodules were divided randomly into training, validation, and testing groups. Receiver operating characteristic curves (ROC) were drawn to compare the diagnostic efficiency of the ANN when applied to radiofrequency and conventional ultrasound images. The sensitivity, specificity, and accuracy of the ANN in predicting malignancy from the radiofrequency ultrasound images were 100, 91.5, and 96.2%, respectively; from conventional ultrasound, the corresponding values were 94.4, 93.2, and 93.9%, respectively. The area under the receiver operating characteristic curve (AUC) was also higher for radiofrequency than conventional ultrasound (AUC = 0.945 vs. 0.917, 95% confidence interval = 0.901-0.998 vs. 0.854-0.979, using a P-value of 0.26). We then classified each nodule into new risk categories according to the output of each sample generated by the proposed method. The malignancy risks in the proposed Categories 3, 4, and 5 were 0, 18.8, and 94.5%, respectively, compared with 0, 55.1, and 88.2% using the American College of Radiology's Thyroid Imaging Reporting and Data System. Thus, this preliminary study initially indicated that the proposed method of using radiofrequency ultrasound and the ANN was more accurate at predicting malignancy and stratifying thyroid nodules than conventional ultrasound methods, thus offering significant potential to reduce the number of unnecessary thyroid biopsies.
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- Comparison of video and conventional laryngoscopes for simulated difficult emergency tracheal intubations in the presence of liquids in the airway. [Journal Article]
- PlosPLoS One 2019; 14(7):e0220006
- The presence of vomit, blood, or other foreign liquid materials in the upper airway is a major obstacle in difficult tracheal intubations (TIs) especially in prehospital care. However, the usefulness…
The presence of vomit, blood, or other foreign liquid materials in the upper airway is a major obstacle in difficult tracheal intubations (TIs) especially in prehospital care. However, the usefulness of video laryngoscopes (VLs) in these situations has not been investigated. The objective of this study was to compare the Airway Scope (AWS) and the Macintosh laryngoscope (ML) for their performance in TIs performed by emergency medical technicians (EMTs) using mannequin models with liquids in the airway. Rice gruel and mock blood were used to fill the upper airways of mannequins to create mock vomit and hematemesis models, respectively. TIs were performed by certified EMTs after visualizing the glottis using an AWS with an 18-Fr suction catheter and a ML with an 18-Fr suction catheter. TIs with AWS and ML were performed in random order in a comparative crossover trial. The TI success rate was evaluated based on the following: (a) the time taken from laryngoscope insertion into the oral cavity to glottis visualization, tracheal tube passage through the glottis, until the initiation of ventilation and (b) the subjective level of difficulty, which was assessed using a visual analog scale (VAS). TIs in vomiting and hematemesis scenarios were performed by 25 and 26 EMTs, respectively. The TI success rates for these scenarios were 100% with both AWS and ML. The median time required until successful ventilation was significantly shorter with AWS than with ML in both the vomiting (42 vs. 58 s) and hematemesis models (33 vs. 39 s), respectively. In the hematemesis scenarios, difficulty assessed using a VAS was lower with AWS than with ML (13 vs. 38 in median), respectively. Compared to the ML, the AWS was capable of faster and easier TIs, in a simulated model of liquid foreign material in the upper airway.