ABSTRACT Purpose: This study aimed to develop a minimally invasive surgical procedure for laminar lift and posterior cervical laminoplasty via the intermuscular approach using a canine model. Methods: Six Alaskan dogs were used for developing the surgical approach. The bilateral laminae of C3-7 were cut with an ultrasonic osteotome and fixed with bilateral plates to maintain the lamina lifting and reshape a wider spinal canal. The important structures, such as ligaments, supraspinous ligaments, interspinous ligaments, and ligamentum flavum were preserved. The therapeutic effect was evaluated by preoperative and postoperative imaging results and neck mobility. Results: The surgical procedures were all successfully performed in the 6 animals. All the dogs survived well within 1 year of postoperative follow-up. The postoperative neck mobility was as good as the preoperative one. Computed tomography results showed that the anteroposterior diameter of the spinal canal was successfully enlarged and maintained well. Conclusions: The minimally invasive surgical procedure for laminar lift and posterior cervical laminoplasty via the intermuscular approach was feasible in a canine model, which might be applied in clinical practice.

Abstract Polyphenol oxidase is the popular enzyme involved in fruit-vegetable browning and melanin synthesis. In the present paper, L-3-phenyllactic acid, a natural bacteriostatic substance, was investigated as an inhibitor of polyphenol oxidase. The results were demonstrated that the residual enzyme activity of polyphenol oxidase decreased gradually with the increase of the concentration of L-3-phenyllactic acid. The L and ΔE values of the reaction system increased gradually. The reversible mixed-type inhibition mode of L-3-phenyllactic acid was determined by Lineweaver Burk plot. At the same time, the results of fluorescence quenching demonstrated that L-3-phenyllactic acid was a quencher of polyphenol oxidase, and the molecular docking study provided the binding mode of L-3-phenyllactic acid and polyphenol oxidase at the molecular level. L-3-phenyllactic acid decreased the activity of polyphenol oxidase and browning of fresh-cut Agaricus Bosporus. This research first studied the inhibitory effect of L-3-phenyllactic acid on the activity of polyphenol oxidase, and would provide a theoretical foundation for the use of L-3-phenyllactic acid as anti-polyphenol oxidase agents.

Durante las últimas décadas, el exceso de velocidad ha sido identificado como el factor más dominante que contribuye a la ocurrencia de accidentes graves y lesiones en las vías, de ahí que la medida de fijar la velocidad límite sea lo más común. Sin embargo, algunos estudios han concentrado sus esfuerzos en el problema de la velocidad límite en ambientes adversos, debido a la reducción en visibilidad y fricción en el pavimento. El propósito principal de esta investigación es desarrollar un prototipo de recomendaciones de velocidad límite para segmentos básicos de autopistas con condiciones ambientales difíciles. Si el vehículo delantero realiza una parada súbita, la distancia de separación del vehículo trasero es dividida en cuatro fases. Suponiendo que la visibilidad sea menor que la distancia segura entre dos vehículos consecutivos, una ecuación parabólica puede ser construida para describir la relación entre la máxima velocidad segura del vehículo, condiciones del pavimento, pendiente del segmento y visibilidad, y de ahí la máxima velocidad segura es redondeada hacia abajo, el múltiplo de 5 más cercano, y es propuesta como la velocidad límite bajo condiciones nubladas, de lluvia y nieve.

Over the past decade, over speeding has been identified to be the most dominant factor contributing to the occurrence of severe crashes and injuries on freeways, and thus speed limit performs the most popular countermeasure. However, few studies have focused on the problem of freeway speed limits in bad weather due to reduction of visibility and pavement friction. Therefore, the primary purpose of this research is to develop a prototype of speed limits recommendations for basic freeway segments under the inclement weather conditions. If the leading vehicle makes a sudden stop, the travelling distance of the following vehicle is divided into four phases. Assuming the visibility is no less than the safe following distance between consecutive vehicles, consequently, a parabolic equation is constructed to describe the relation between the vehicle's maximum safe speed, pavement conditions, segment slope and visibility, and then maximum safe speed is rounded down to the nearest multiple of 5 as the proposed speed limit under the fogy, rainy or snowy conditions.

In this paper, polyacrylamide (PAM)-modified magnetite (Fe3O4) nanoparticles were prepared by in situ polymerization in aqueous solution. The particle size, morphology, crystal phase and magnetic properties were measured utilizing scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM), respectively. The size distribution and stability of the nano-particles in aqueous solution were evaluated using the laser particle size analyzer and ultraviolet-visible spectroscopy (UV-vis). The influences of the dose of acrylamide (AM) and the pH value on the particle size and stability were also examined. The results showed that the Fe3O4 nanoparticles possessed superparamagnetic property and super dispersion stability in aqueous solution after PAM modification.