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Objectives: To test the hypothesis that restoration of class II mesio-occlusal-distal (MOD) cavities can be strengthened through judicious choice of restoration geometry and material properties., Methods: An intact extracted human maxillary molar tooth was digitized, segmented, reconstructed, and four 3D restored tooth models were developed with four different restoration geometries: one straight, one single-curved, and two double-curved. Stress analysis was conducted for representative loading using finite element analysis, and maximum principal stresses were determined at the dentine-enamel and restoration-enamel junctions. A range of restorative material elastic moduli (5-80 GPa) and Poisson's ratios (0.25-0.35) were studied. Vertical loads of 400 N were applied on occlusal points, while the roots of the molar teeth, below the crevices, were supported in all directions. All the materials were modelled as homogeneous, isotropic, and elastic., Results: The maximum principal stresses at the restoration-enamel junctions were strongly dependent on the MOD restoration geometries. Peak stresses occurred along the palatal surface of the restoration rather than the opposite buccal surface. Double-curved restorations showed the lowest peak stress at restoration-enamel junctions. Choice of the mechanical properties of restorative material in the range of 5-35 GPa further reduced stress concentrations on the enamel., Significance: Class II MOD restorations may be stronger if designed with double-curved marginal geometries that can reduce stress concentrations. Designs with convex and concave geometries were particularly effective because they reduced stress concentrations dramatically. Results suggest that relatively minor changes to the geometry of a restoration can have a substantial effect on stress at the restoration-enamel junction and motivate future experimental analysis., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Distributed fibre optic sensors (DFOS) are popular for structural health monitoring applications in large engineering infrastructure because of their ability to provide spatial strain measurements continuously along their lengths. Curved paths, particularly semicircular paths, are quite common for optical fibre placement in large structures in addition to straight paths. Optical fibre sensors embedded in a curved path configuration typically measure a component of strain, which often cannot be validated using traditional approaches. Thus, for most applications, strain measured along curved paths is ignored as there is no proper validation tool to ensure the accuracy of the measured strains. To overcome this, an analytical strain transformation equation has been developed and is presented here. This equation transforms the horizontal and vertical strain components obtained along a curved semicircular path into a strain component, which acts tangentially as it travels along the curved fibre path. This approach is validated numerically and experimentally for a DFOS installed on a steel specimen with straight and curved paths. Under tensile and flexural loading scenarios, the horizontal and vertical strain components were obtained numerically using finite element analysis and experimentally using strain rosettes and then, substituted into the proposed strain transformation equation for deriving the transformed strain values. Subsequently, the derived strain values obtained from the proposed transformation equation were validated by comparing them with the experimentally measured DFOS strains in the curved region. Additionally, this study has also shown that a localised damage to the DFOS coating will not impact the functionality of the sensor at the remaining locations along its length. In summary, this paper presents a valid strain transformation equation, which can be used for transforming the numerical simulation results into the DFOS measurements along a semicircular path. This would allow for a larger scope of spatial strains measurements, which would otherwise be ignored in practice.

Localized surface plasmon resonances (LSPR) of nanostructures can be tuned by controlling their morphology, local dielectric environment, and free carrier concentration. We report the colloidal synthesis of an ∼3 tungsten-oxygen (W-O) layer thick (∼1 nm), two-dimensional (2D) WO 3- x nanoplatelets (NPLs) ( x ≈ 0.55-1.03), which display tunable near-infrared LSPR properties and additionally high free electron density ( N e ) that arises predominantly from the large shape factor of 2D NPLs. Importantly, the W to O composition ratios inferred from their LSPR measurements show much higher percentage of oxygen vacancies than those determined by X-ray diffraction analysis, suggesting that the aspect ratio of ultrathin WO 3- x NPLs is the key to producing an unprecedentedly large N e , although synthesis temperature is also an independent factor. We find that NPL formation is kinetically controlled, whereas thermodynamic parameter manipulation leads to N e values as high as 4.13 × 10 22 cm -3 , which is close to that of plasmonic noble metals, and thus our oxide-based nanostructures can be considered as quasi-metallic . The unique structural properties of 2D nanomaterials along with the high N e of WO 3- x NPLs provide an attractive alternative to plasmonic noble metal nanostructures for various plasmon-driven energy conversions and design of photochromic nanodevices.

Background: The clinical utility of measuring pressure at the prosthetic socket-residual limb interface is currently unknown., Objectives: This study aimed to identify whether measuring interface pressure during prosthetic design and fabrication results in closer agreement in pressure measurements between sockets made by different clinicians, and a reduction in pressure over areas of concern. It also investigated whether clinicians value knowing the interface pressure during the fabrication process., Study Design: Mixed methods., Methods: Three prosthetists designed a complete prosthetic system for a transtibial residual limb surrogate. Standardised mechanical testing was performed on each prosthetic system to gain pressure measurements at four key anatomical locations. These measurements were provided to the clinicians, who subsequently modified their sockets as each saw fit. The pressure at each location was re-measured. Each prosthetist completed a survey that evaluated the usefulness of knowing interface pressures during the fabrication process., Results: Feedback and subsequent socket modifications saw a reduction in the pressure measurements at three of the four anatomical locations. Furthermore, the pressure measurements between prosthetists converged. All three prosthetists found value in the pressure measurement system and felt they would use it clinically., Conclusions: Results suggest that sensors measuring pressure at the socket-limb interface has clinical utility in the context of informing prosthetic socket design and fabrication. If the technology is used at the check socket stage, iterative designs with repeated measurements can result in increased consistency between clinicians for the same residual limb, and reductions in the magnitudes of pressures over specific anatomical landmarks., Clinical Relevance: This study provides new information on the value of pressure feedback to the prosthetic socket design process. It shows that with feedback, socket modifications can result in reduced limb pressures, and more consistent pressure distributions between prosthetists. It also justifies the use of pressure feedback in informing clinical decisions.

For efficient charge separations, multimaterial hetero-nanostructures are being extensively studied as photocatalysts. While materials with one heterojunction are widely established, the chemistry of formation of multijunction heterostructures is not explored. This needs a more sophisticated approach and modulations. To achieve these, a generic multistep seed mediated growth following controlled ion diffusion and ion exchange is reported which successfully leads to triple-material hetero-nanostructures with bimetallic-binary alloy-binary/ternary semiconductors arrangements. Ag 2 S nanocrystals are used as primary seeds for obtaining AuAg-AuAgS bimetallic-binary alloyed metal-semiconductor heterostructures via partial reduction of Ag(I) using Au(III) ions. These are again explored as secondary seeds for obtaining a series of triple-materials heterostructures, AuAg-AuAgS-CdS (or ZnS or AgInS 2 ), with introduction of different divalent and trivalent ions. Chemistry of each step of the gold ion-induced changes in the rate of diffusion and/or ion exchanges are investigated and the formation mechanism for these nearly monodisperse triple material heterostructures are proposed. Reactions without gold are also performed, and the change in the reaction chemistry and growth mechanism in presence of Au is also discussed., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Herein, we demonstrate the preparation of highly luminescent carbon quantum dots (CQDs) from Aloe vera leaf gel; in just 2h at 250°C through carbonization pathway. The prepared CQDs are structurally characterized with high resolution transmission electron microscopy (HRTEM), hydrodynamic diameter, surface polarity, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Raman, UV-visible absorption spectrophotometry and fluorescence spectroscopy. The functional carbon nanoparticles are observed as non-cytotoxic materials. The biocompatibility, less cytotoxicity and high aqueous dispersibility of as-synthesized CQDs are motivated to design carbon quantum dot (CQD) tailored calcium alginate (CA) hydrogel films with an aim to controlled delivery of glycopeptides antibiotic vancomycin in the gastrointestinal tract (GI). With CQD, the drug loading capacity of CA/CQD film is increased to 89% from 38% (CA film), whereas; with β-cyclodextrin (β-CD) the vancomycin uptake capacity is increased more, 96%. The release of vancomycin through CA/CQD film is more pronounced at pH1.5, close to the pH of the stomach and it is found that in pH1.5 with β-CD, the release rate of vancomycin is lowered, 56% in 120h. The high drug uptake capacity (96%) and lower release rate (56% in 120h) of CA/CQD hydrogel film in pH1.5 with β-CD can be used for its applicability as drug delivery vehicle for controlled release of vancomycin into the stomach region and therefore it can offer a potential option for oral administration of vancomycin., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Objectives: The characterization of the physical properties of dental resin composites is fraught with difficulties relating to significant intra and inter test parameter variabilities and is relatively time consuming and expensive. The main aim of this study was to evaluate whether optical fiber Bragg grating (FBG) sensing system may become a viable tool to study dental material characteristics. Of particular focus was the potential for the system to demonstrate a multi parameter all-in-one feature., Methods: A miniature FBG was embedded in six different dental resin composites and employed as a sensor to evaluate linear polymerization shrinkage, thermal expansion and water sorption. Six commercially available dental composites with different filler types and volume are evaluated. The tests are repeated with three sets of samples. The curing characteristics and residual strain gradient exhibited by the cured dental composites were also observed and commented., Results: Among the studied samples, SDR shows lowest polymerization shrinkage, while Beautifil FO3 shows the highest. The results also show clear distinction between particle filler type and fiber reinforcement based composites in their polymerization shrinkage properties. The agreement of the results with existing literatures show that FBG based system provides accurate results. Polymerization shrinkage rate of the samples are also obtained. Thermal expansion of the composites are measured using the FBG sensing method for the first time and is correlated with resin type, volume, filler type and glass transition temperature. The water sorption characteristics of the dental composite are also successfully measured using the FBG sensing method. The high level of repeatability and the low standard deviations shown in the results indicate good reliability with the use of FBG sensors., Significance: This study demonstrates how optical fiber technology can provide simple and reliable methods of measuring the critical physical properties of dental composites. In addition due to the embedding and preservation of the sensor within the samples multiple parameters can be tested for with the same sample. These features are expected to greatly assist material science researchers in dentistry as well as other biomedical fields. Of some interest the phenomenon of stress relaxation of dental composite at higher temperature was observed., (Copyright © 2016 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.)

A generic modular synthetic strategy for the fabrication of a series of binary-ternary group II-VI and group I-III-VI coupled semiconductor nano-heterostructures is reported. Using Ag2 Se nanocrystals first as a catalyst and then as sacrificial seeds, four dual semiconductor heterostructures were designed with similar shapes: CdSe-AgInSe2 , CdSe-AgGaSe2 , ZnSe-AgInSe2 , and ZnSe-AgGaSe2 . Among these, dispersive type-II heterostructures are further explored for photocatalytic hydrogen evolution from water and these are observed to be superior catalysts than the binary or ternary semi-conductors. Details of the chemistry of this modular synthesis have been studied and the photophysical processes involved in catalysis are investigated., (© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Fixed-aspect-ratio rod-to-rod conversion of binary V-VI Sb2 Se3 to ternary I-V-VI Cu3 SbSe3 semiconducting nano structures is reported. Capturing the inter mediate products, the insight mechanisms of the ion-diffusion process for the structural transformation are established. The final ternary structure shows localized surface plasmonresonance-induced absorption in the near-infrared regions., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The classical mechanism of crystal growth for architecting different nanomaterials in solution, although widely studied, is mainly restricted to binary semiconductor systems. However, this method is not applicable to multinary nanomaterials, which have multivalent cations possessing different reactivity under identical reaction conditions. Hence, the shape architectures of these nanostructures, which require a more sophisticated approach, remain relatively unexplored compared to those of binary semiconductors. Owing to the importance of the multinary materials, which are emerging as excellent green materials for both light harvesting and light emission, we investigated the diffusion-rate-controlled formation of ternary AgGaSe2 nanostructures and studied their heterostructures with noble metals. Controlling the changes in the rate of diffusion of the Ag ions resulted in the formation of tadpole-shaped AgGaSe2 ternary nanostructures. In situ study by collecting a sequential collection of samples has been carried out, and the conversion of amorphous Ga-selenide to crystalline AgGaSe2 has been monitored. In addition, heterostructures of tadpole AgGaSe2 with noble metals, Au and Pt, were designed, and their photocatalytic behaviors were studied.

Doping foreign impurities in host nanomaterials can induce new materials properties. In addition, doping can also influence the crystallization process and change the shape and/or phase of the host material. While dopant-induced changes in the properties of materials have been well studied, the concept of doping and its chemistry in the design of different nanostructures has rarely been investigated. In order to further understand the doping chemistry, this study investigated the dopant-controlled enhancement of the rate of the chemical reaction during the transformation from one doped material to another and the consequent effect on the shape evolution of the nanostructures. These are performed during the selenization of metal Pd(0), using Ag dopant. While the controlled process produced cuboidal Pd17Se15 from the quasi-spherical nanocrystals of Pd(0), on doping, the shape of Pd17Se15 transformed into hollow cubes. The rate was also enhanced by more than 30 times for the doped case in comparison to undoped Pd(0). Importantly, while for the undoped nanocrystals, the selenization approached in one direction, where for the doped particles, it occurred all around the nanocrystals and triggered the Kirkendall effect. Detailed investigations were conducted to elucidate the influence of the dopant on both the rate and directional approach of selenization in Pd(0), initiation of the fast diffusion of Pd, change in shape, and formation of the hollow structures. To our understanding, the role of dopants in controlling chemical processes is of fundamental importance, and this will undoubtedly broaden the scope of research on the chemistry of doping and crystal growth in solution.

Seventeen patients with posterior fossa extradural haematoma are presented. While 7 patients had acute course, 6 had subacute and 4 had chronic course. All patients had evidence of occipital injury. Two patients did not have any fracture in the occipital bone. Concomitant lesions included cerebellar contusion in 3 cases, cerebral contusion in 4 patients, supratentorial extradural haematoma in 2 and hydrocephalus in 2 patients. All but one patient were treated surgically. None of the supratentorial lesions were operated upon. All patients with subacute and chronic course had good outcome while 43% with acute course succumbed to death. Besides the initial clinical status the co-existing lesions signifying the increased severity of injury have influenced the mortality and quality of outcome. In presence of occipital fracture a careful observation and timely intervention are warranted.

Nine patients with traumatic epidural haematoma (EDH) have been reported and literature reviewed. Drowsiness was present in 5, dullness in 3 and papilloedema in 2 cases. Four patients had hemiparesis. The thickness of the haematoma was 1.6 cms in one and 4.3 cms in another while in the rest it was 1.6 cms or less. Patients with minor head injury (Glasgow Coma Score [GCS] 13-15) with mild clinical symptoms in static or recovery phase and minimal signs presenting late after 36 hours of injury, where CT scan reveals diffuse haematoma (rather than localised one indenting on the brain) of thickness less than 1.5 cms without midline shift may be managed without surgical intervention only if facilities for close observation are available. Surgical evacuation is the gold standard for all extradural haematomas when there is any doubt.

We are reporting a case of craniopharyngioma presenting with features of mania. To our knowledge, this is the first reported case of craniopharyngioma with presenting features of mania- The patient is a six years old child with history of maniac behaviour of six months duration. There is no significant family history. During the course in the hospital he was found to be having craniopharyngioma. The patient recovered completely following the surgical intervention without any aid of antipsychotics.