A Novel Cryogenic Approach to 3D Printing Cytocompatible, Conductive, Hydrogel-Based Inks.

In the field of tissue engineering and regenerative medicine, developing cytocompatible 3D conductive scaffolds that mimic the native extracellular matrix is crucial for the engineering of excitable cells and tissues. In this study, a custom cryogenic extrusion 3D printer was developed, which afforded control over both the ink and printing surface temperatures. Using this approach, aqueous inks were printed into well-defined layers with high precision.

Enhanced photoactivity and selectivity over BiOI-decorated BiWO microflower for selective oxidation of benzylamine: Role of BiOI and mechanism.

The importance of developing effective and selective photocatalytic materials to realize efficient renewable energy-based organic synthetic processes, such as selective oxidation of benzylamines and its derivatives to the corresponding imines has become more apparent in recent years. Here we present the first reported BiOI/BiWO (BI/BW) microflower heterostructure as a visible-light-driven photocatalyst for such reactions. By decorating the hydrothermally prepared BW with BI via successive ionic layer adsorption and reaction (SILAR) method, benzylamine conversion is improved from 68 % to 92 % as compared to undecorated.

LED PEDD Discharge Photometry: Effects of Software Driven Measurements for Sensing Applications.

This work explores the effects of embedded software-driven measurements on a sensory target when using a LED as a photodetector. Water turbidity is used as the sensory target in this study to explore these effects using a practical and important water quality parameter. Impacts on turbidity measurements are examined by adopting the Paired Emitter Detector Diode (PEDD) capacitive discharge technique and comparing common embedded software/firmware implementations.

Advances in Optical Based Turbidity Sensing Using LED Photometry (PEDD).

Turbidity is one of the primary metrics to determine water quality in terms of health and environmental concerns, however analysis typically takes place in centralized facilities, with samples periodically collected and transported there. Large scale autonomous deployments (WSNs) are impeded by both initial and per measurement costs. In this study we employ a Paired Emitter-Detector Diode (PEDD) technique to quantitatively measure turbidity using analytical grade calibration standards.

Flexible Polymer X-ray Detectors with Non-fullerene Acceptors for Enhanced Stability: Toward Printable Tissue Equivalent Devices for Medical Applications.

There is growing interest in the development of novel materials and devices capable of ionizing radiation detection for medical applications. Organic semiconductors are promising candidates to meet the demands of modern detectors, such as low manufacturing costs, mechanical flexibility, and a response to radiation equivalent to human tissue. However, organic semiconductors have typically been employed in applications that convert low energy photons into high current densities, for example, solar cells and LEDs, and thus existing design rules must be re-explored for ionizing radiation detection where high energy photons are converted into typically much lower current densities.

Solvothermally synthesized anatase TiO2 nanoparticles for photoanodes in dye-sensitized solar cells.

Many researchers working on the development of Dye-sensitized solar cells (DSCs) continue to focus on the synthesis of photoanode materials with high surface area, along with high light scattering ability to enhance light harvesting efficiency (LHE). On the other hand, dye packing density, which can also affect the LHE significantly, is often overlooked. Solvothermally synthesized anatase TiO nanoparticles (SANP) were obtained by a new and simple approach using a mixed solvent, ethanol and acetic acid.

The effect of amorphous TiO in P25 on dye-sensitized solar cell performance.

P25 is one of the most widely used forms of titanium(iv) oxide (TiO), routinely utilised in dye-sensitised solar cells (DSCs), where it is often employed as a control, in spite of its poorly defined nature and the typically low device efficiency (or possibly because of this). Work by Park in 2000 and later by Lin et al. suggests that the rutile component might not be to blame for this, as has often been claimed.

Aggregated mesoporous nanoparticles for high surface area light scattering layer TiO photoanodes in Dye-sensitized Solar Cells.

Hierarchically structured aggregates, consisting of TiO nanoparticles were produced via one-step solvothermal syntheses with a mixed solvent system containing both acetic acid and ethanol. Two of the resulting structures, one ~700 nm and the other ~300 nm in diameter, were found to be comprised of 8.5 nm and 10.

Composite Photocatalysts Containing BiVO for Degradation of Cationic Dyes.

The creation of composite structures is a commonly employed approach towards enhanced photocatalytic performance, with one of the key rationales for doing this being to separate photoexcited charges, affording them longer lifetimes in which to react with adsorbed species. Here we examine three composite photocatalysts using either WO, TiO or CeO with BiVO for the degradation of model dyes Methylene Blue and Rhodamine B. Each of these materials (WO, TiO or CeO) has a different band edge energy offset with respect to BiVO, allowing for a systematic comparison of these different arrangements.

Understanding chemically processed solar cells based on quantum dots.

Photovoltaic energy conversion is one of the best alternatives to fossil fuel combustion. Petroleum resources are now close to depletion and their combustion is known to be responsible for the release of a considerable amount of greenhouse gases and carcinogenic airborne particles. Novel third-generation solar cells include a vast range of device designs and materials aiming to overcome the factors limiting the current technologies.

Improving the Medical Curriculum in Predoctoral Dental Education: Recommendations From the American Association of Oral and Maxillofacial Surgeons Committee on Predoctoral Education and Training.

Dental procedures are often performed on patients who present with some level of medical fragility. In many dental schools, the exercise of taking a medical history is all too often a transcription of information to the dental chart, with little emphasis on the presurgical risk assessment and the development of a treatment plan appropriate to the medical status of the dental patient. Changes in dentistry, driven by an increasingly medically complex population of dental patients, combined with treatment advances rooted in the biomedical sciences necessitate the adaptation of our dental education to include a stronger background in systemic health.

Bone Reduction to Facilitate Immediate Implant Placement and Loading Using CAD/CAM Surgical Guides for Patients With Terminal Dentition.

The aim of this study is to present a method, using 3 computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guides, to accurately obtain the desired bone reduction followed by immediate implant placements and loading for patients diagnosed with terminal dentition. Patients who had bone reduction, implants placed, and immediate loading using Anatomage Invivo 5 CAD/CAM surgical guides between the period 2013 and 2015 were evaluated retrospectively. Patients diagnosed with terminal dentition and treated using the "3-guide technique" were identified.

Accuracy Assessment of Immediate and Delayed Implant Placements Using CAD/CAM Surgical Guides.

The aim of this study is to assess the accuracy of immediately placed implants using Anatomage Invivo5 computer-assisted design/computer-assisted manufacturing (CAD/CAM) surgical guides and compare the accuracy to delayed implant placement protocol. Patients who had implants placed using Anatomage Invivo5 CAD/CAM surgical guides during the period of 2012-2015 were evaluated retrospectively. Patients who received immediate implant placements and/or delayed implant placements replacing 1-2 teeth were included in this study.

Increased upconversion performance for thin film solar cells: a trimolecular composition.

Photochemical upconversion based on triplet-triplet annihilation (TTA-UC) is employed to enhance the short-circuit currents generated by two varieties of thin-film solar cells, a hydrogenated amorphous silicon (a-Si:H) solar cell and a dye-sensitized solar cell (DSC). TTA-UC is exploited to harvest transmitted sub-bandgap photons, combine their energies and re-radiate upconverted photons back towards the solar cells. In the present study we employ a dual-emitter TTA-UC system which allows for significantly improved UC quantum yields as compared to the previously used single-emitter TTA systems.

Trap-Assisted Transport and Non-Uniform Charge Distribution in Sulfur-Rich PbS Colloidal Quantum Dot-based Solar Cells with Selective Contacts.

This study reports evidence of dispersive transport in planar PbS colloidal quantum dot heterojunction-based devices as well as the effect of incorporating a MoO3 hole selective layer on the charge extraction behavior. Steady state and transient characterization techniques are employed to determine the complex recombination processes involved in such devices. The addition of a selective contact drastically improves the device efficiency up to 3.

An intermediate band dye-sensitised solar cell using triplet-triplet annihilation.

A new mechanism of charge photogeneration is demonstrated for the first time, based on organic molecular structures. This intermediate band approach, integrated into a dye-sensitised solar cell configuration is shown to generate charges upon illumination with low energy photons. Specifically 610 nm photoexcitation of Pt porphyrins, through a series of energy transfer steps and triplet-triplet annihilation, excites a higher energy absorption onset molecule, which is then capable of charge injection into TiO2.

The effect of surface passivation on the structure of sulphur-rich PbS colloidal quantum dots for photovoltaic application.

The use of PbS colloidal quantum dots in photovoltaic devices is very promising because of their simple and low cost production processes and their unique properties, such as bandgap tunability and potential multiple exciton generation. Here we report the synthesis of PbS nanocrystals used for application in solar cells. The sulphur-rich nature of their surface appears to be caused by the exposure to ambient conditions.

N719- and D149-sensitized 3D hierarchical rutile TiO2 solar cells--a comparative study.

Poor dye loading on rutile TiO2 is one of the chief reasons for lower solar-to-electric conversion efficiency (η) in dye-sensitized solar cells (DSCs), compared to their anatase based counterparts. Previously, we showed that similar light harvesting for both rutile and anatase was realized by using a metal-free organic indoline dye, D149 [Sci. Rep.

Integrating a triplet-triplet annihilation up-conversion system to enhance dye-sensitized solar cell response to sub-bandgap light.

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology.

Photocatalytic degradation of methyl orange by CeO2 and Fe-doped CeO2 films under visible light irradiation.

Undoped CeO2 and 0.50-5.00 mol% Fe-doped CeO2 nanoparticles were prepared by a homogeneous precipitation combined with homogeneous/impreganation method, and applied as photocatalyst films prepared by a doctor blade technique.

3D hierarchical rutile TiO2 and metal-free organic sensitizer producing dye-sensitized solar cells 8.6% conversion efficiency.

Three-dimensional (3D) hierarchical nanoscale architectures comprised of building blocks, with specifically engineered morphologies, are expected to play important roles in the fabrication of 'next generation' microelectronic and optoelectronic devices due to their high surface-to-volume ratio as well as opto-electronic properties. Herein, a series of well-defined 3D hierarchical rutile TiO2 architectures (HRT) were successfully prepared using a facile hydrothermal method without any surfactant or template, simply by changing the concentration of hydrochloric acid used in the synthesis. The production of these materials provides, to the best of our knowledge, the first identified example of a ledgewise growth mechanism in a rutile TiO2 structure.

Enhanced visible-light photocatalytic activity of g-C3N4/TiO2 films.

Enhanced photocatalytic degradation of methylene blue (MB) using graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) catalyst films has been demonstrated in this present work. The g-C3N4/TiO2 composites were prepared by directly heating the mixture of melamine and pre-synthesized TiO2 nanoparticles in Ar gas flow. The g-C3N4 contents in the g-C3N4/TiO2 composites were varied as 0, 20, 50 and 70 wt%.

Carbon nanotube - reduced graphene oxide composites for thermal energy harvesting applications.

By controlling the SWNT-rGO electrode composition and thickness to attain the appropriate porosity and tortuosity, the electroactive surface area is maximized while rapid diffusion of the electrolyte through the electrode is maintained. This leads to an increase in exchange current density between the electrode and electrolyte which results in enhanced thermocell performance.