Occlusal Loading Effect on Stress Distribution of Endodontically Treated Teeth: Finite Element Analysis Study.

AIM: Evaluate the influence of occlusal loading on the stress distribution of endodontically treated teeth after root canal preparation with different file's sizes and tapers by means of finite element analysis. METHODOLOGY: Seven three-dimensional models of a single-rooted, single-canal lower second premolar were established, one healthy control and six endodontically treated and restored models. The shape of root canal preparations followed file configurations 30/.05, 30/.09, 35/.04, 35/.06, 40/.04, and 40/.06. Von- Mises equivalent stresses were calculated by applying 30 N, 90 N and 270 N loads to the buccal cusp tip, each one at 90º, 45º and 20º angles from the occlusal plane simulating occlusion, dental interference and laterality, respectively. RESULTS: 45º loading was more prone to formation of higher stress values. The simulation of occlusion and laterality resulted in maximum stress areas located at the inner side of the root curvature, while under occlusal interference they were on the lingual surface over the tooth's long axis. CONCLUSIONS: The angulation of occlusal loading and magnitude were determinants for stress distribution on dental structure. Both variations of size and taper were not determinants for the increase in the maximum stress areas.

Prognostic value of thrombocytosis in patients undergoing surgery for colorectal cancer with synchronous liver metastases.

PURPOSE: The purpose of this study was to evaluate the prognostic role of thrombocytosis in patients with synchronous colorectal liver metastases (CRLM). METHODS: Retrospective analysis of patients who underwent surgery for colorectal cancer with synchronous CRLM at the Division of General and Hepatobiliary Surgery, University of Verona Hospital Trust between 2005 and 2016. RESULTS: One hundred and ninety-six patients met the inclusion criteria. High platelet count (H-PC) was found in 32%, and it was associated with a higher rate of palliative surgery (p < 0.001), extra-hepatic metastases (p < 0.001), bilobar liver disease (p = 0.007), presence of more than three metastases (p = 0.005), biggest metastasis larger than 5 cm (p < 0.001), and CEA level higher than 200 ng/mL (p = 0.035). H-PC was significantly associated with poorer 5-year overall survival (14.3% vs. 34.3%; p = 0.001). At the multivariate analysis on R0-1 cases, platelet count resulted the only independent predictor of survival (HR 2.07, p = 0.036). CONCLUSION: H-PC correlates with the main negative clinical-pathological factors in patients with synchronous CRLM, as well as with overall survival. Moreover, it was the only independent prognostic factor in those who underwent curative surgery.

Possible effects of clustering structure in the competition between fast emission processes and compound nucleus decay / Posibles efectos de estructura de agrupamiento en la competencia entre los procesos de emisión rápida y desintegración del núcleo compuesto

Abstract The attention to nuclear clustering has been renewed due to the study of weakly bound nuclei at the drip lines. In particular, clustering structural properties in medium-mass systems have been studied by looking at the competition between the evaporation and pre-equilibrium particle emission in central collisions. Although for light nuclei at an excitation energy close to the particle separation value there are experimental evidence of such structure effects, this is still not the case for heavier systems since the determination of pre-formed clusters within nuclear matter is less obvious. Two systems, leading to the same 81Rb* compound nucleus, have been studied at the same beam velocity 16 AMeV: 16O + 65Cu and 19F + 62Ni. The experiment has been performed using the GARFIELD + RCo detection system installed at the Legnaro National Laboratories.Light charged particles energy distributions and multiplicities have been compared with different statistical and dynamical model calculations. From the first comparison between the two systems a difference in the fast α-decay channel has been evidenced, which can be related to the difference in the projectile structure. Recent data analysis results and comparisons with model calculations are presented in this contribution.

Resumen La atención a la agrupación nuclear se ha renovado debido al estudio de núcleos débilmente unidos en las líneas de goteo. En particular, se han estudiado las propiedades estructurales del agrupamiento en sistemas de masa media al observar la competencia entre la evaporación y la emisión de partículas de preequilibrio en colisiones centrales. Aunque para núcleos ligeros a una energía de excitación cercana al valor de separación de la partícula hay evidencia experimental de tales efectos de estructura, este no es el caso para sistemas más pesados ya que la determinación de agrupamientos preformados dentro de la materia nuclear es menos obvia. Se han estudiado dos sistemas, que conducen al mismo núcleo compuesto 81Rb *, a la misma velocidad de haz 16 AMeV: 16O + 65Cu y 19F + 62Ni. El experimento se ha realizado utilizando el sistema de detección GARFIELD + RCo instalado en los Laboratorios Nacionales Legnaro. Las distribuciones de energía y las multiplicidades de partículas de carga ligera se han comparado con diferentes cálculos de modelos estadísticos y dinámicos. Desde la primera comparación entre los dos sistemas, se ha evidenciado una diferencia en el canal de desintegración α rápida, que se puede relacionar con la diferencia en la estructura del proyectil. En esta contribución se presentan los resultados del análisis de datos recientes y las comparaciones con los cálculos del modelo.

Robotic phrenic nerve harvest: a feasibility study in a pig model.

The aim of this study was to report on the feasibility of robotic phrenic nerve harvest in a pig model. A surgical robot (Da Vinci S™ system, Intuitive Surgical(®), Sunnyvale, CA) was installed with three ports on the pig's left chest. The phrenic nerve was transected distally where it enters the diaphragm. The phrenic nerve harvest was successfully performed in 45 minutes without major complications. The advantages of robotic microsurgery for phrenic nerve harvest are the motion scaling up to 5 times, elimination of physiological tremor, and free movement of joint-equipped robotic arms. Robot-assisted neurolysis may be clinically useful for harvesting the phrenic nerve for brachial plexus reconstruction.

Brachial plexus endoscopy: feasibility study on cadavers.

UNLABELLED: The development of a minimally invasive technique for exploration of the brachial plexus seems a logical step towards refinement of diagnosis and treatment. For certain pathological conditions, minimally invasive techniques have become the method of choice; for others, they remain as an ancillary option for assistance during open surgery. We have developed a full endoscopic technique for brachial plexus exploration. Our endoscopic technique used saline liquid infusion in seven brachial plexus of four cadavers. Five portals have been described and the endoscopic landmarks also. We were able to demonstrate excellent views and adequate possibilities for cadaver plexus dissection and its anatomic landmarks and portals. LEVEL OF EVIDENCE: 4.

Anomalous presentation of flexor carpi radialis brevis: a report of six cases.

An anomalous presentation of flexor carpi radialis brevis (FCRB) is reported in six patients. These findings occurred in a consecutive series of 172 distal radius fracture fixations using a volar approach between 2002 and 2007. This is the first report of this anomalous muscle from a clinical series.

Four corner arthrodesis limited to the centre using a scaphoid one piece graft and a dorsal circular plate.

We present 20 patients, who had a four corner arthrodesis, from July 2006 to March 2008, using a dorsal circular plate, to treat scaphoid nonunion and scapholunate dissociation with advanced collapse (SNAC, SLAC). The surgical technique was a fusion restricted to the central area filled with one piece of cancellous bone graft taken from the excised scaphoid. Wrist motion, grip strength, and Disabilities of Arm Shoulder and Hand (DASH) score improved after surgery at a mean follow-up of 20.2 months. Fusion occurred in 19/20 patients. Two patients (10%) had persistent pain. The rest had a good clinical result. We found that four-corner fusion using a dorsal circular plate using the specific technical modifications was successful.

Análise da adaptação marginal de coifas: confeccionadas em ligas de Ni-Cr e In-Ceram® Zircônia sobre componente Ceraone / Analyzed of the marginal fit of coping manufacture

O presente trabalho avaliou microscopicamente a adaptação de coifas confeccionadas em ligas de Níquel-Cromo (Ni-Cr) Wiron® 99 In-Ceram® Zircônia sobre componentes do tipo CeraOne®. Para tal foram confeccionadas 10 coifas de cada tipo de material, e após estas serem adaptadas sobre os componentes, foram avaliadas em microscópio eletrônico pra mensurar o tamanho do desajuste de cada material. Foram analisadas seis faces de cada coifa, e após foi feita análise estatística dos valores através do teste Wilcoxon-Mann-Whitney. Foi constatado que as coifas confeccionadas em ligas de Níquel-Cromo obtiveram médias de desadaptação menores, de 81,37 µm, com limite de desajuste mínimo de 63,5 µm e limite de desajuste máximo de 114,5 µm, com amplitude de 51,0 µm e que as coifas de In-Ceram® Zircônia o valor médio de desadaptação obtido foi de 107,75 µm, com limite de desajuste mínimo de 64,5 µm e máximo de 175 µm, com amplitude de 110,5 µm