Three-dimensional virtual bone bank system workflow for structural bone allograft selection: a technical report

Structural bone allograft has been used in bone defect reconstruction during the last fifty years with acceptable results. However, allograft selection methods were based on 2-dimensional templates using X-rays.Thanks to preoperative planning platforms, three dimensional (3D) CT-derived bone models were used to define size and shape comparison between host and donor. The purpose of this study was to describe the workflow of this virtual technique in order to explain how to choose the best allograft using a virtualbone bank system. We measured all bones in a 3D virtual environment determining the best match. The use of a virtual bone banksystem has allowed optimizing the allograft selection in a bone bank, providing more information to the surgeons before surgery.In conclusion, 3D preoperative planning in a virtual environment for allograft selection is an important and helpful tool in order to achieve a good match between host and donor.Fil: Ritacco, Lucas. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Farfalli, Germán Luis. Hospital Italiano; ArgentinaFil: Milano, Federico Edgardo. Hospital Italiano; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ayerza, Miguel Ángel. Hospital Italiano; ArgentinaFil: Muscolo, Domingo L.. Hospital Italiano; Argentina. Hospital Italiano; ArgentinaFil: Aponte Tinao, Luis. Hospital Italiano; Argentin

Aqueous two-phase systems within selectively permeable vesicles

An aqueous two-phase system (ATPS) encapsulated within a vesicle organizes the vesicle core as two coexisting phases that partition encapsulated solutes. Here, we use microfluidic technologies to produce vesicles that efficiently encapsulate mixtures of macromolecules, providing a versatile platform to determine the phase behavior of ATPSs. Moreover, we use compartmentalized vesicles to investigate how membrane permeability affects the dynamics of the encapsulated ATPS. Designing a membrane selectively permeable to one of the components of the ATPS, we show that out-of-equilibrium phase separations formed by a rapid outflow of water can be spontaneously reversed by a slower outflow of the permeating component across the vesicle membrane. This dynamics may be exploited advantageously by cells to separate and connect metabolic and signaling routes within their nucleoplasm or cytoplasm depending on external conditionsThe authors acknowledge financial support from the Spanish Ministry of Science and Innovation (MCI) through the María de Maeztu Programme for Units of Excellence in R&D (CEX2018-000805-M). L.R.A. and J.L.A. also acknowledge financial support from MCI through the Ramón y Cajal Programme (RYC2018-025575-I and RYC2019-028189-I; MCI/AEI/FSE, UE

Capacidad condrogénica de injertos libres de periostio en la reparación de defectos del cartílago articular: estudio experimental en conejos

Ante la incapacidad de reparación de las lesiones del cartílago articular, hemos diseñado un modelo experimental, consistente en la realización de una úlcera condral de 8 mm, en la superficie articular de la rótula, en 48 conejos distribuidos en 2 series. Mientras en la serie control (24 conejos) dicha úlcera se dejó a evolución espontánea, en la experimental (24 conejos) fue cubierta con plastia libre de periostio tibial para poder investigar la posibilidad de regeneración del cartílago articular. Los resultados se valoraron macroscópica y microscópicamente a intervalos de 1, 2, 4 y 8 semanas, comprobando la ausencia de regeneración espontánea y el desarrollo de un neocartílago hialino a partir de la plastia de periostio, con lo que se demuestra la capacidad condrogénica de la misma.An animal experimental study was designed in order to repair chondral defects of 8 mm. diameter, performed at the articular surface of the patella in adult rabitts. A total of 48 animals were operated. The control serie consisted of 24 animals in which the defect was not repaired. In other 24 animals, the defect was covered whit a free tibial periosteal praft. Rcsults were evaluated macro and microscopically at 1, 2, 4 and 8 weeks after surgeon. In control cases, there were no spontaneous repair while in case with periosteal implantation, a new trialine cartilage originated in the implanted tissue was observed. These findings demonstrated the chondrogenic capacity of periosteal free grafts for repair of articular surface defects

Floating Bare Tether as Upper Atmosphere Probe

Use of a (bare) conductive tape electrically floating in LEO as an effective e-beam source that produces artificial auroras, and is free of problems that have marred standard beams, is considered. Ambient ions impacting the tape with KeV energies over most of its length liberate secondary electrons, which race down the magnetic field and excite neutrals in the E-layer, resulting in auroral emissions. The tether would operate at night-time with both a power supply and a plasma contactor off; power and contactor would be on at daytime for reboost. The optimal tape thickness yielding a minimum mass for an autonomous system is determined; the alternative use of an electric thruster for day reboost, depending on mission duration, is discussed. Measurements of emission brightness from the spacecraft could allow determination of the (neutral) density vertical profile in the critical E-layer; the flux and energy in the beam, varying along the tether, allow imaging line-of-sight integrated emissions that mix effects with altitude-dependent neutral density and lead to a brightness peak in the beam footprint at the E-layer. Difficulties in tomographic inversion, to determine the density profile, result from beam broadening, due to elastic collisions, which flattens the peak, and to the highly nonlinear functional dependency of line-of-sight brightness. Some dynamical issues are discussed

The “Effect of Marangoni convection on heat transfer in Phase Change Materials” experiment, from a student project to the International Space Station

This manuscript summarizes the educational and scientific outcome of the Research-based learning activities performed in the bachelor’s, master’s, and doctorate programmes in aerospace engineering at the Technical University of Madrid. The activities are related to the line of research in Phase Change Materials in microgravity developed at the Spanish User Support and Operations Centre. The principal scientific results obtained during these years are outlined, drawing particular attention to those related to the “Thermocapillary Effects in Phase Change Materials in Microgravity” experiment and the “Effect of Marangoni convection on heat transfer in Phase Change Materials” project. The outcomes of this research are discussed from an educational perspective. Since 2016, we observe an increased interest from students to participate in research activities, which has had direct positive impact on the production of scientific result

Reparación de lesiones del cartílago articular de la rótula de conejos con injertos libres de pericondrio costal y periostio tibial: Estudio histológico comparativo

El propósito del presente, estudio experimental es comparar la capacidad condrogénica de injertos libres de pericondrio y periostio en lesiones que afectan a todo el espesor del cartílago articular rotuliano. Para ellos, se eligieron 18 conejos adolescentes de Nueva Zelanda con un peso comprendido entre los 2400 y 3600 gramos, a los que se realizó una lesión de 6 mm de diámetro y 3 mm de espesor en la superficie articular de la rótula, y se distribuyeron de modo aleatorio en tres grupos: control, tratados con injerto libre de pericondrio (PC) y tratados con injerto libre de periostio (PO). Todos los animales fueron sacrificados a las 8 semanas y las preparaciones histológicas fueron evaluadas con arreglo a una escala que concede una puntuación de 0 a 17 puntos. En el análisis estadístico, las diferencias encontradas han sido, en todos los casos, entre el control y los grupos tratados, para ninguna de las variables se ha podido demostrar diferencias estadísticamente significativas entre los grupos PC y PO.The purpose of this experimental study was to compare the chondrogenic capacity of both perichondrium and periosteal free grafts in lesions affecting all the articular chondral thickness of the patella. A total of 18 white New Zeland rabbits with a weight ranging from 2.4 to 3.6 kg were operated. A chondral lesion o f 6 mm of diameter and 3 mm in depth was performed at the articular surface on the patella. The lesion was repair with either a perichondrium (6 animals) or a periosteal free grafts (6 animals). In other 6 animals, the control group, the lesion was not repaired. All animals were killed 8 weeks after surgery. Histological studies were performed using a modified O'Discoll's scale. Statistically significant differences were found between the control group and the two groups in which the lesions were repaired, but not between lesions treated with perichondrium and periosteal grafts

Allograft Selection for Transepiphyseal Tumor Resection Around the Knee Using Three-Dimensional Surface Registration

Transepiphyseal tumor resection is a common surgical procedure in patients with malignant bone tumors. The aim of this study is to develop and validate a computer-assisted method for selecting the most appropriate allograft from a cadaver bone bank. Fifty tibiae and femora were 3D reconstructed from computed tomography (CT) images. A transepiphyseal resection was applied to all of them in a virtual environment. A tool was developed and evaluated that compares each metaphyseal piece against all other bones in the data bank. This is done through a template matching process, where the template is extracted from the contralateral healthy bone of the same patient. The method was validated using surface distance metrics and statistical tests comparing it against manual methods. The developed algorithm was able to accurately detect the bone segment that best matches the patient's anatomy. The automatic method showed improvement over the manual counterpart. The proposed method also substantially reduced computation time when compared to state-of-the-art methods as well as the manual selection. Our findings suggest that the accuracy, robustness, and speed of the developed method are suitable for clinical trials and that it can be readily applied for preoperative allograft selectio

Floating bare tether as upper atmosphere probe

Use of a conductive bare tape electrically floating in low Earth orbit as an effective electron beam source to produce artificial auroral effects, free of problems that mard tandard beams, is considered. Ambient ions impacting the tape with keV energies over most of its length liberate secondary electrons that race down the magnetic field, excite neutrals in the E layer, and result in auroral emissions. The tether would operate with both a power supply and a plasma contactor off at nighttime; power and contactor would be on at daytime for reboost. Tomographic analysis of auroral emissions from the footprint of the beam, as observed from the spacecraft, can provide density profiles of dominant neutral species in the E layer. A characteristic tether system, at altitude 300 km and moderate orbital inclination, would involve an aluminum tape with a length of 20 km, a width of 15 mm, and a thickness of 0.2 mm for a full-system mass around 1200 kg, with two thirds going into the power subsystem

Leptospirosis porcina: prevalencia serológica en establecimientos productores de la República Argentina

RESUMENObjetivo. Detectar la presencia de anticuerpos contra Leptospira sp en cerdos que no presentaban sintomatología clínica, pertenecientes a establecimientos de producción porcina ubicados en todo el territorio de la República Argentina. Materiales y métodos. La asignación de predios y muestras se realizó en forma proporcional a los registrados en cada provincia a lo largo de todo el país. En total se estudiaron 1.524 predios, de los cuales se tomaron 19.872 muestras de suero y en la primera etapa se procesaron 3.631 de los mismos. Este estudio toma en consideración zonas identificadas por provincia, municipio y predios. Los sueros fueron analizados por la técnica de MAT (prueba de microaglutinación). Resultados. El 30% de las muestras resultaron positivas a la prueba tamiz empleada (primera etapa del MAT). La mayoría presentó coaglutininas a dos o a tres serovariedades. Al realizar la titulación de los sueros (segunda etapa del MAT), el porcentaje de positividad se mantuvo, siendo los serovares de mayor prevalencia Castellonis e Icterohaemorrhagiae. El 90% de las muestras presentó un título final de 1:200. Conclusiones. La existencia de sueros positivos en todas las provincias indica el contacto de los animales con la leptospira a lo largo de todo el país

Taking Intellectual Property Rights Seriously: Are We In or Out? (Phase 1: Intellectual Property Awareness Among Students and Faculty: Tracking Changing Attitudes and Awareness)

The study was conducted to assess the intellectual property awareness among students and faculty was undertaken to determine attitudes, existing IP delivery, drivers seeking information, aspirations, identify unmet needs and generate suggestions to improve the IP system. A mixed method approach using both quantitative and qualitative methodologies were carried out to a prospective group of students and faculty. Data were analyzed and descriptive statistics were used and further analysis using inferential statistics were calculated to compare results. For the students, the most important and relevant topics to the study of Intellectual Property includes knowing where to find and use patent information and the most common method of delivering IP lessons was through briefing workshop on IP, followed by modules and integrating issues in the course. In order to improve IP Delivery, students noted that they prefer to give more emphasis on the overview of IP, patents, copyright, design right and plagiarism. However, students considered that they know some things about Intellectual Property but there were gaps to be filled in. Findings revealed from faculty respondents showed association of the inclusion of the understanding of disclosure and confidentiality to gender, program of students handled by faculty, and cluster where faculty belongs. Moreover, recognition for collaborative work has significant impact on program of students and academic level of faculty. Similarly, other relevant topics like exploiting ideas commercially was found to be associated also with the program of students handled by faculty. Tenure classification was indicated to be associated with understanding health and safety regulations. Results of the focus group discussion with faculty members included improvement of IP delivery and services, curriculum development to include IP education, problems on IP processing, preparation of documents for application. Keywords: intellectual property awareness, IP rights, IP perspectives and insight