Mechanistic and Clinical Studies of Platelet Rich Plasma: A Simple Clinical Method for Enhancing Bone and Soft Tissue Healing

Platelet rich plasma (PRP) is a methodology of using a patient\u27s own platelets to enhance bone and soft tissue healing following oral surgical procedures. Whole blood is drawn from the patient by conventional phlebotomy techniques and then centrifuged with the formation of a distinct middle layer that contains platelets and white blood cells (WBCs). This layer of platelets and WBCs is then placed into the surgical site to enable faster and more predictable healing. This technique has also found use in general medical surgeries and is gaining in popularity. Platelets contain growth factors and other cytokines that are beneficial for healing following surgical trauma. This project uses both in vitro and in vivo studies to provide the mechanistic basis for the continued and possible expanded clinical use of PRP. A simple and inexpensive technique for acquiring PRP is examined and provides evidence that during the platelet harvesting steps the platelets are properly concentrated, not altered, and that growth factors (GFs) critical to bone formation are present. A retrospective clinical trial provides data that illustrate a significant decrease (p \u3c .0001) in the frequent complication of dry socket (alveolar osteitis, AO) formation following mandibular tooth extractions. The study reveals that not using PRP is a risk factor for AO formation. The project also utilizes a molecular study utilizing human mesenchymal stem cells (hMSCs) to provide a mechanistic basis for bone formation following PRP use. Enhanced proliferation and inducement of differentiation of hMSCs were found to the possible explanations for the clinical successes reported with PRP use. A prospective clinical study provides radiographic evidence for increased radiographic opacity (indicating bone formation) during the initial two weeks following placement of PRP at the time of mandibular third molar removal. This translational research offers scientific support for the use of PRP in osseous surgeries. The use of this simple and inexpensive PRP technique could help patients recover faster, with fewer complications and greater bone formation predictability following surgeries involving bone manipulation

First record of phoresy of Dendrochernes cyrneus (L. Koch, 1873) (Pseudoscorpiones, Chernetidae) on Cerambyx cerdo Linnaeus, 1758 (Coleoptera, Cerambycidae) and their potential value as bioindicators

El primer registro de foresía de Dendrochernes cyrneus (L. Koch, 1873) (Pseudoscorpiones, Chernetidae) en Cerambyx cerdo Linnaeus, 1758 (Coleoptera, Cerambycidae) y su valor potencial como bioindicadores Se documenta la primera prueba de foresía de Dendrochernes cyrneus (L. Koch, 1873) en Cerambyx cerdo Linnaeus, 1758. También se presenta una revisión crítica de todos los informes científicos publicados sobre la foresía relacionados con D. cyrneus. Dos de estos informes guardan relación con la misma observación y son el resultado de la confusión sistemática existente en la familia Cerambycidae. Ambas especies se tratan como vestigios del bosque primigenio y sus aisladas poblaciones viven en las zonas residuales dispersas de los bosques antiguos que cubrían Europa en el pasado. Aportamos nueva información sobre las relaciones ecológicas de D. cyrneus con escarabajos saproxílicos y analizamos las preferencias ecológicas de las dos especies y su función como indicadores de la calidad del ambiente.El primer registro de foresía de Dendrochernes cyrneus (L. Koch, 1873) (Pseudoscorpiones, Chernetidae) en Cerambyx cerdo Linnaeus, 1758 (Coleoptera, Cerambycidae) y su valor potencial como bioindicadores Se documenta la primera prueba de foresía de Dendrochernes cyrneus (L. Koch, 1873) en Cerambyx cerdo Linnaeus, 1758. También se presenta una revisión crítica de todos los informes científicos publicados sobre la foresía relacionados con D. cyrneus. Dos de estos informes guardan relación con la misma observación y son el resultado de la confusión sistemática existente en la familia Cerambycidae. Ambas especies se tratan como vestigios del bosque primigenio y sus aisladas poblaciones viven en las zonas residuales dispersas de los bosques antiguos que cubrían Europa en el pasado. Aportamos nueva información sobre las relaciones ecológicas de D. cyrneus con escarabajos saproxílicos y analizamos las preferencias ecológicas de las dos especies y su función como indicadores de la calidad del ambiente.The first evidence of phoresy of Dendrochernes cyrneus (L. Koch, 1873) on Cerambyx cerdo Linnaeus, 1758 is documented. A critical review of all known literature reports of phoresy involving D. cyrneus is also presented. Two of these reports relate to the same observation and are the result of the systematic turmoil within the family Cerambycidae. Both species are treated as primeval forest relics and their isolated populations live in the scattered remains of the ancient forests that covered Europe in the past. We provide new information about the ecological relationships of D. cyrneus with saproxylic beetles, and discuss the ecological preferences of the two species and their role as indicators of the quality of the environment

The application of canting keel concept in racing windsurfing fins: does it lead to superior performance?

Windsurfing is a young, dynamically evolving sport. As the numbers of windsurfers increase around the world, equipment producers race against each other, using the latest materials and technologies in the never ending pursuit of better performance. The aim of this research is to investigate the latest development idea – the canting fin. The project is based on Formula Windsurfing, a racing discipline, where fins reach 70cm of length and have crucial influence on a competitor’s final result. Primary data was collected in two stages, in both qualitative and quantitative forms. The former involved 4 male, international-level windsurfing competitors who tested two provided sample fins – one of a classic design and the other, with the same geometry and material properties but altered into the canting concept. Subjects’ observations were recorded using a semi-structured questionnaire. The second stage of data gathering was based on GPS measurements of fins’ performance. Once again the two described sample foils were used to identify the advantages and disadvantages of the novel design. At this point, over 5000 of speed and course measurements were taken providing a significant data set. The presented results show numerous differences between the tested fins. Overall, combining all of the measured characteristics, the canting fin proved to be superior by 44% in a simulated competition situation. In a competitive situation, research participants would have chosen the new fin in 87% of the tested situations over the classic design. The project generated an interesting set of results without having to base on multiple assumptions. It was 100% practise-based and was designed as an alternative to laboratory-based modelling. Factors influencing data precision and the measurement error were discussed and several areas for further research were outlined

Thermal resistance of PCD materials with borides bonding phase

In these studies, one group of PCD materials was prepared using diamond powder and 10 wt % of TiB₂ and the second batch of the PCD material was prepared using a mixture of diamond powder with 5 wt % of TiB₂ and 2 wt % of Co. The materials have been sintered using a Bridgman-type high-pressure apparatus at 8.0±0.2 GPa, at a temperature of 2000±50 °C. Thermogravimetric (TG) measurements and Differential Thermal Analysis (DTA) have been carried out for diamond micropowders, TiB₂ bonding phase, and sintered composites. The coefficients of friction for diamond composites in a sliding contact with an Al₂O₃ ceramic ball have been determined from the room temperature up to 800 °C. Material phase compositions were analyzed for initial samples and after wear tests, at the temperature of 800 °C. Raman spectra of diamond composites with borides bonding phases, observed for the first-order zone centre modes of diamond and graphite during the heating up to 800 °C in air have been presented. Thermal properties have been compared with the commercial diamond-cobalt PCD. It has been found that diamond with TiB₂ and Co is the most resistant to the hardness changes at elevated temperatures and this material maintains the high hardness value up to 800 °C but it has a high coefficient of friction.Досліджено полікристалічні алмазні композити – одну групу матеріалів було приготовано з використанням алмазного порошку і 10 % (за масою) TiB₂, а другу – з алмазного порошку, 5 % (за масою) TiB₂ і 2 % (за масою) Co. Матеріали було спечено в апараті високого тиску типу Бріджмена при тиску 8,0±0,2 ГПа і температурі 2000±50 °С. Термогравіметричні вимірювання та диференційний термічний аналіз було проведено для алмазних мікропорошків, зв’язуючої фази TiB₂ і спечених композітов. Визначено коефіцієнти тертя для алмазних композитів при ковзному контакті з кулькою з кераміки Al₂O₃ при температурі від кімнатної до 800 °С. Фазові склади матеріалів проаналізовано для вихідних зразків і після їх випробування на знос при температурі 800 °С. Представлено спектри комбінаційного розсіювання алмазних композитів зі зв’язуючими фазами боридів, що спостерігаються в центрі зони першого порядку алмазу і графіту в процесі нагрівання до 800 °С на повітрі. Порівнювали термічні властивості отриманих полікристалічних алмазних композитів і промислового композита алмаз–кобальт. Було виявлено, що алмаз з TiB₂ і Co є найбільш стійким до змін твердості при підвищених температурах і зберігає високу твердість до 800 °С, але має високий коефіцієнт тертя.Исследованы поликристаллические алмазных композиты – одна группа материалов была приготовлена с использованием алмазного порошка и 10 % (по массе) TiB₂, а вторая – из алмазного порошка, 5 % (по массе) TiB₂ и 2 % (по массе) Co. Материалы были спечены в аппарате высокого давления типа Бриджмена при давлении 8,0±0,2 ГПа и температуре 2000±50 °С. Термогравиметрические измерения и дифференциальный термический анализ были проведены для алмазных микропорошков, связующей фазы TiB₂ и спеченных композитов. Определены коэффициенты трения для алмазных композитов при скользящем контакте с шариком из керамики Al₂O₃ при температуре от комнатной до 800 °С. Фазовые составы материалов проанализированы для исходных образцов и после их испытания на износ при температуре 800 °С. Представлены спектры комбинационного рассеяния алмазных композитов со связующими фазами боридов, наблюдаемые в центре зоны первого порядка алмаза и графита в процессе нагрева до 800 °С на воздухе. Сравнивали термические свойства полученных поликристаллических алмазных композитов и промышленного поликристаллического композита алмаз–кобальт. Было обнаружено, что алмаз с TiB₂ и Co является наиболее устойчивым к изменениям твердости при повышенных температурах и сохраняет высокую твердость до 800 °С, но имеет высокий коэффициент трения

A Stimulated Raman Loss spectrometer for metrological studies of quadrupole lines of hydrogen isotopologues

We discuss layout and performance of a high-resolution Stimulated Raman Loss spectrometer that has been newly developed for accurate studies of spectral lineshapes and line center frequencies of hydrogen isotopologues and in general of Raman active transitions. Thanks to the frequency comb calibration of the detuning between pump and Stokes lasers and to an active alignment of the two beams, the frequency accuracy is well below 100 kHz. Over the vertical axis the spectrometer benefits from shot-noise limited detection, signal enhancement via multipass cell, active flattening of the spectral baseline and measurement times of few seconds over spectral spans larger than 10 GHz. Under these conditions an efficient averaging of Raman spectra is possible over long measurement times with minimal distortion of spectral lineshapes. By changing the pump laser, transitions can be covered in a very broad frequency span, from 50 to 5000 $\mathrm{cm^{-1}}$, including both vibrational and rotational bands. The spectrometer has been developed for studies of fundamental and collisional physics of hydrogen isotopologues and has been recently applied to the metrology of the Q(1) 1-0 line of $\mathrm{H_2}$

The effect of charge separation on the phase behavior of dipolar colloidal rods

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.Colloids with anisotropic shape and charge distribution can assemble into a variety of structures that could find use as novel materials for optical, photonic, electronic and structural applications. Because experimental characterization of the many possible types of multi-shape and multipolar colloidal particles that could form useful structures is difficult, the search for novel colloidal materials can be enhanced by simulations of colloidal particle assembly. We have simulated a system of dipolar colloidal rods at fixed aspect ratio using discontinuous molecular dynamics (DMD) to investigate how the charge separation of an embedded dipole affects the types of assemblies that occur. Each dipolar rod is modeled as several overlapping spheres fixed in an elongated shape to represent excluded volume and two smaller, embedded spheres to represent the charges that make up the extended dipole. Large charge separations predominately form structures where the rods link head-to-tail while small charge separations predominately form structures where the rods stack side-by-side. Rods with small charge separations tend to form dense aggregates while rods with large charge separations tend to form coarse gel-like structures. Structural phase boundaries between fluid, string-fluid, and "gel'' (networked) phases are mapped out and characterized as to whether they have global head-to-tail or global side-by-side order. A structural coarsening transition is observed for particles with large charge separations in which the head-tail networks thicken as temperature is lowered due to an increased tendency to form side-by-side structures. Triangularly connected networks form at small charge separations; these may be useful for encapsulating smaller particles.DFG, GRK 1524, Self-Assembled Soft-Matter Nanostructures at Interface

IK-FA, a new heuristic inverse kinematics solver using firefly algorithm

In this paper, a heuristic method based on Firefly Algorithm is proposed for inverse kinematics problems in articulated robotics. The proposal is called, IK-FA. Solving inverse kinematics, IK, consists in finding a set of joint-positions allowing a specific point of the system to achieve a target position. In IK-FA, the Fireflies positions are assumed to be a possible solution for joints elementary motions. For a robotic system with a known forward kinematic model, IK-Fireflies, is used to generate iteratively a set of joint motions, then the forward kinematic model of the system is used to compute the relative Cartesian positions of a specific end-segment, and to compare it to the needed target position. This is a heuristic approach for solving inverse kinematics without computing the inverse model. IK-FA tends to minimize the distance to a target position, the fitness function could be established as the distance between the obtained forward positions and the desired one, it is subject to minimization. In this paper IK-FA is tested over a 3 links articulated planar system, the evaluation is based on statistical analysis of the convergence and the solution quality for 100 tests. The impact of key FA parameters is also investigated with a focus on the impact of the number of fireflies, the impact of the maximum iteration number and also the impact of (a, ß, ¿, d) parameters. For a given set of valuable parameters, the heuristic converges to a static fitness value within a fix maximum number of iterations. IK-FA has a fair convergence time, for the tested configuration, the average was about 2.3394 × 10-3 seconds with a position error fitness around 3.116 × 10-8 for 100 tests. The algorithm showed also evidence of robustness over the target position, since for all conducted tests with a random target position IK-FA achieved a solution with a position error lower or equal to 5.4722 × 10-9.Peer ReviewedPostprint (author's final draft