Comprehensive Development of a Cellulose Acetate and Soy Protein-Based Scaffold for Nerve Regeneration.

BACKGROUND: The elaboration of biocompatible nerve guide conduits (NGCs) has been studied in recent years as a treatment for total nerve rupture lesions (axonotmesis). Different natural polymers have been used in these studies, including cellulose associated with soy protein. The purpose of this report was to describe manufacturing NGCs suitable for nerve regeneration using the method of dip coating and evaporation of solvent with cellulose acetate (CA) functionalized with soy protein acid hydrolysate (SPAH). METHODS: The manufacturing method and bacterial control precautions for the CA/SPAH NGCs were described. The structure of the NGCs was analyzed under a scanning electron microscope (SEM); porosity was analyzed with a degassing method using a porosimeter. Schwann cell (SCL 4.1/F7) biocompatibility of cell-seeded nerve guide conduits was evaluated with the MTT assay. RESULTS: The method employed allowed an easy elaboration and customization of NGCs, free of bacteria, with pores in the internal surface, and the uniform wall thickness allowed manipulation, which showed flexibility; additionally, the sample was suturable. The NGCs showed initial biocompatibility with Schwann cells, revealing cells adhered to the NGC structure after 5 days. CONCLUSIONS: The fabricated CA/SPAH NGCs showed adequate features to be used for peripheral nerve regeneration studies. Future reports are necessary to discuss the ideal concentration of CA and SPAH and the mechanical and physicochemical properties of this biomaterial.

Exploring Schwann Cell Behavior on Electrospun Polyhydroxybutyrate Scaffolds with Varied Pore Sizes and Fiber Thicknesses: Implications for Neural Tissue Engineering.

The placement of a polymeric electrospun scaffold is among the most promising strategies to improve nerve regeneration after critical neurotmesis. It is of great interest to investigate the effect of these structures on Schwann cells (SCs), as these cells lead nerve regeneration and functional recovery. The aim of this study was to assess SC viability and morphology when cultured on polyhydroxybutyrate (PHB) electrospun scaffolds with varied microfiber thicknesses and pore sizes. Six electrospun scaffolds were obtained using different PHB solutions and electrospinning parameters. All the scaffolds were morphologically characterized in terms of fiber thickness, pore size, and overall appearance by analyzing their SEM images. SCs seeded onto the scaffolds were analyzed in terms of viability and morphology throughout the culture period through MTT assay and SEM imaging. The SCs were cultured on three scaffolds with homogeneous smooth fibers (fiber thicknesses: 2.4 µm, 3.1 µm, and 4.3 µm; pore sizes: 16.7 µm, 22.4 µm, and 27.8 µm). SC infiltration and adhesion resulted in the formation of a three-dimensional network composed of intertwined fibers and cells. The SCs attached to the scaffolds maintained their characteristic shape and size throughout the culture period. Bigger pores and thicker fibers resulted in higher SC viability.

Effects of Low-Level Laser Therapy and Purified Natural Latex (Hevea brasiliensis) Protein on Injured Sciatic Nerve in Rodents: Morpho-Functional Analysis.

The present study analyzed the effects of low-level laser therapy (LLLT) and the purified natural latex protein (Hevea brasiliensis, F1 protein) on the morpho-function of sciatic nerve crush injuries in rats. One-hundred and eight male Wistar rats were randomly allocated to six groups (n = 18): 1. Control; 2. Exposed (nerve exposed); 3. Injury (injured nerve without treatment); 4. LLLT (injured nerve irradiated with LLLT (15 J/cm2, 780 nm)); 5. F1 (injured nerve treated with F1 protein (0.1%)); and 6. LLLT + F1 (injured nerve treated with LLLT and F1). On the 1st, 7th, 14th, and 56th days after injury, a functional sensory analysis of mechanical allodynia and mechanical hyperalgesia and a motor analysis of grip strength and gait were performed. After 3, 15, and 57 days, the animals were euthanized for morphometric/ultrastructural analyses. The treatments applied revealed improvements in morphometric/ultrastructural parameters compared to the injured group. Sensory analyses suggested that the improvements observed were associated with time progression and not influenced by the treatments. Motor analyses revealed significant improvements in grip strength from the 7th day in the LLLT group and in gait from the 56th day in all treated groups. We concluded that even though the morphological analyses showed improvements with the treatments, they did not influence sensory recovery, and LLLT improved motor recovery.

Characterization of Mandibular Border Movements and Mastication in Each Skeletal Class Using 3D Electromagnetic Articulography: A Preliminary Study.

Mandibular movement recording is relevant for the planning and evaluation of mandibular function. These movements can include mandibular border movements (MBM) or mastication. Our objective was to characterize the kinematics of MBM and mastication among skeletal classes I, II, and III in the three spatial planes. A descriptive cross-sectional study was conducted with 30 participants. Instructions were provided on how to form Posselt's envelope and to perform masticatory. After data processing, we obtained numerical values for the areas, trajectories, and ranges of MBM that formed Posselt's envelope and the values for speed, masticatory frequency, and the areas of each masticatory cycle. Significant differences were found in the area of Posselt's envelope in the horizontal plane between skeletal classes I and III and in the range of right laterality between skeletal classes II and III. Mastication showed significant differences in the area of the masticatory cycles in the horizontal plane between classes I and III and between classes II and III. In conclusion, there were differences in MBM and mastication between skeletal classes III and I in the horizontal plane. This study supports the need to establish normal values for mandibular kinematics in skeletal class III.

Determination of Mandibular Position and Mouth Opening in Healthy Patients and Patients with Articular and/or Muscular Pathology: A Pilot Study with 3D Electromagnetic Articulography and Surface Electromyography.

Temporomandibular disorders (TMDs) are a group of pathologies that affect the temporomandibular joint and its related structures, producing intracapsular and muscular pathologies. The aim of this study is to describe, by electromagnetic articulography (EMA) and simultaneous electromyography (sEMG), the mandibular postural position and mouth opening in healthy patients and with articular and/or muscular pathology. MATERIALS AND METHODS: A pilot study was conducted with a sample of sixteen participants aged 18 years or older who attended the TMDs and Orofacial Pain Polyclinic of the University of La Frontera due to TMDs. The physiological inoculation space was evaluated from the mandibular postural position (MPP) with swallowing command and without command, in both healthy patients and patients with articular, muscular, and mixed TMDs, measured simultaneously with EMA and sEMG. An angular measurement of the oral opening was also performed with the data obtained. RESULTS: The physiological inoculation space was obtained from the determination of the MPP through the procedures with swallowing command and without command, and different mouth opening degrees were evaluated. CONCLUSIONS: Simultaneous position and sEMG records can be produced from EMA, and different characterization variables such as the vertical distance, Euclidean distance, and angle can be obtained.

Assessing siliceous sinter matrices for long-term preservation of lipid biomarkers in opaline sinter deposits analogous to Mars in El Tatio (Chile).

Subaerial hydrothermal systems are of great interest for paleobiology and astrobiology as plausible candidate environments to support the origin of life on Earth that offer a unique and interrelated atmosphere-hydrosphere-lithosphere interface. They harbor extensive sinter deposits of high preservation potential that are promising targets in the search for traces of possible extraterrestrial life on Hesperian Mars. However, long-term quality preservation is paramount for recognizing biosignatures in old samples and there are still significant gaps in our understanding of the impact and extent of taphonomy processes on life fingerprints. Here, we propose a study based on lipid biomarkers -highly resistant cell-membrane components- to investigate the effects of silicification on their preservation in hydrothermal opaline sinter. We explore the lipid biomarkers profile in three sinter deposits of up to ~3000 years from El Tatio, one of the best Martian analogs on Earth. The lipid profile in local living biofilms is used as a fresh counterpart of the fossil biomarkers in the centuries-old sinter deposits to qualitatively assess the taphonomy effects of silicification on the lipid's preservation. Despite the geological alteration, the preserved lipids retained a depleted stable-carbon isotopic fingerprint characteristic of biological sources, result highly relevant for astrobiology. The data allowed us to estimate for the first time the degradation rate of lipid biomarkers in sinter deposits from El Tatio, and to assess the time preservation framework of opaline silica. Auxiliary techniques of higher taxonomic resolution (DNA sequencing and metaproteomics) helped in the reconstruction of the paleobiology. The lipids were the best-preserved biomolecules, whereas the detection of DNA and proteins dropped considerably from 5 cm depth. These findings provide new insights into taphonomy processes affecting life fingerprints in hydrothermal deposits and serves as a useful baseline for assessing the time window for recovering unambiguous signs of past life on Earth and beyond.

A Novel Technique to Accurately Measure Mouth Opening Using 3D Electromagnetic Articulography.

The mouth opening is an important indication of the functionality of the temporomandibular joint (TMJ). Mouth opening is usually evaluated by asking the patient to open their mouth as wide as possible and measuring the distance between the edges of the frontal incisors with a ruler or caliper. With the advancement of technology, new techniques have been proposed to record mandibular movement. The aim of this work is to present a novel technique based on 3D electromagnetic articulography and data postprocessing to analyze the mouth opening considering distances, trajectories, and angles. A maxilla-mandible phantom was used to simulate the mouth opening movement and fixed position mouth opening. This was recorded using the AG501 3D EMA (Carstens Medizinelektronik GmbH, Bovenden, Germany). The collected data was processed using Matlab (Mathworks, Natick, MA, USA). Fix and mobile mouth opening of 1, 2, 3 and 4 cm were simulated. It was possible to evaluate the mandibular opening through the vertical distance, the Euclidean distance, the trajectory, and the opening angle. All these values were calculated and the results were consistent with expectations. The trajectory was the highest value obtained while the vertical distance was the lowest. The angle increased as the mouth opening increased. This new technique opens up new possibilities in future research since oral opening can be analyzed using multiple variables without the need to use different devices or depending on the researcher's experience. This will make it possible to establish which parameter presents significant differences between groups of patients or between patients who have undergone some treatment.

Comprehensive Metabolic and Taxonomic Reconstruction of an Ancient Microbial Mat From the McMurdo Ice Shelf (Antarctica) by Integrating Genetic, Metaproteomic and Lipid Biomarker Analyses.

Paleobiological reconstructions based on molecular fossils may be limited by degradation processes causing differential preservation of biomolecules, the distinct taxonomic specificity of each biomolecule type, and analytical biases. Here, we combined the analysis of DNA, proteins and lipid biomarkers using 16S and 18S rRNA gene metabarcoding, metaproteomics and lipid analysis to reconstruct the taxonomic composition and metabolisms of a desiccated microbial mat from the McMurdo Ice Shelf (MIS) (Antarctica) dated ~1,000 years BP. The different lability, taxonomic resolution and analytical bias of each biomolecule type led to a distinct microbial community profile. DNA analysis showed selective preservation of DNA remnants from the most resistant taxa (e.g., spore-formers). In contrast, the proteins profile revealed microorganisms missed by DNA sequencing, such as Cyanobacteria, and showed a microbial composition similar to fresh microbial mats in the MIS. Lipid hydrocarbons also confirmed Cyanobacteria and suggested the presence of mosses or vascular plant remnants from a period in Antarctica when the climate was warmer (e.g., Mid-Miocene or Eocene). The combined analysis of the three biomolecule types also revealed diverse metabolisms that operated in the microbial mat before desiccation: oxygenic and anoxygenic photosynthesis, nitrogen fixation, nitrification, denitrification, sulfur reduction and oxidation, and methanogenesis. Therefore, the joint analysis of DNA, proteins and lipids resulted in a powerful approach that improved taxonomic and metabolic reconstructions overcoming information gaps derived from using individual biomolecules types.

Lipid Profiles From Fresh Biofilms Along a Temperature Gradient on a Hydrothermal Stream at El Tatio (Chilean Andes), as a Proxy for the Interpretation of Past and Present Biomarkers Beyond Earth.

Hydrothermal systems and their deposits are primary targets in the search for fossil evidence of life beyond Earth. However, to learn how to decode fossil biomarker records in ancient hydrothermal deposits, we must first be able to interpret unambiguously modern biosignatures, their distribution patterns, and their association with physicochemical factors. Here, we investigated the molecular and isotopic profile of microbial biomarkers along a thermal gradient (from 29 to 72°C) in a hot spring (labeled Cacao) from El Tatio, a geyser field in the Chilean Andes with abundant opaline silica deposits resembling the nodular and digitate structures discovered on Mars. As a molecular forensic approach, we focused on the analysis of lipid compounds bearing recognized resistance to degradation and the potential to reconstruct the paleobiology of an environment on a broader temporal scale than other, more labile, biomolecules. By exploiting the lipid biomarkers' potential to diagnose biological sources and carbon fixation pathways, we reconstructed the microbial community structure and its ecology along the Cacao hydrothermal transect. The taxonomic adscription of the lipid biomarkers was qualitatively corroborated with DNA sequencing analysis. The forensic capacity of the lipid biomarkers to identify biosources in fresh biofilms was validated down to the genus level for Roseiflexus, Chloroflexus, and Fischerella. We identified lipid biomarkers and DNA of several new cyanobacterial species in El Tatio and reported the first detection of Fischerella biomarkers at a temperature as high as 72°C. This, together with ecological peculiarities and the proportion of clades being characterized as unclassified, illustrates the ecological singularity of El Tatio and strengthens its astrobiological relevance. The Cacao hydrothermal ecosystem was defined by a succession of microbial communities and metabolic traits associated with a high- (72°C) to low-(29°C) temperature gradient that resembled the inferred metabolic sequence events from the 16S rRNA gene universal phylogenetic tree from thermophilic to anoxygenic photosynthetic species and oxygenic phototrophs. The locally calibrated DNA-validated lipidic profile in the Cacao biofilms provided a modern (molecular and isotopic) end member to facilitate the recognition of past biosources and metabolisms from altered biomarkers records in ancient silica deposits at El Tatio analogous to Martian opaline silica structures.

Masticatory function according to body mass index: part II: electromyographic analysis / Función masticatoria según índice de masa corporal: parte II: análisis electromiográfico

Introduction: The objective of this study was to explore the electrical activity of the superficial muscles of mastication required to exert unilateral maximum bite force in subjects with different body mass index. Material and Methods: A cross-sectional observational study was conducted with a sample of 21 participants with an average age of 22.9 ± 3.5 years who were classified according to their body mass index, forming three study groups: normal weight (18.5-24.9), overweight (25-29.9) and obesity (≥30), with seven participants each. Through surface electromyography, the superficial muscles of mastication during right and left maximum bite force were evaluated. Results: No statistically significant differences in the maximum bite force were observed between the study groups. The data obtained from the electromyographic analysis of the superficial muscles of mastication demonstrate a trend indicating that subjects with a normal body mass index similarly activate the muscles on each side when performing a maximum bite force on a particular side, while overweight or obese subjects demonstrated significantly greater activation of the temporalis muscle associated with the side where the maximal bite force is performed. Conclusion: Our findings suggest that the maximum bite force is not influenced by body mass index and that during the performance of a maximum bite force subjects with increased body mass index present a greater activation of the temporalis muscle associated with the side where the maximum bite force was performed.

Introducción: El objetivo de este estudio fue explorar la actividad eléctrica de los músculos superficiales de la masticación, necesarios para ejercer la máxima fuerza de mordida unilateral, en sujetos con diferente índice de masa corporal. Material y Métodos: Se realizó un estudio observacional de corte transversal con una muestra de 21 participantes con una edad promedio de 22.9 ± 3.5 años, quienes fueron clasificados de acuerdo a su índice de masa corporal, formando tres grupos de estudio: peso normal (18,5-24,9), sobrepeso (25,0-29,9) y obesidad (≥30.0), con siete participantes cada uno. La electromiografía de superficie evaluó los músculos superficiales de la masticación durante la fuerza de mordida máxima derecha e izquierda. Resultados: No se observaron diferencias estadísticamente significativas en la fuerza de mordida máxima entre los grupos de estudio. Los datos obtenidos del análisis electromiográfico de los músculos superficiales de la masticación demuestran una tendencia que indica que los sujetos con un índice de masa corporal normal activan de manera similar los músculos de cada lado cuando ejercen la fuerza de mordida máxima en un lado en particular. mientras que los sujetos con sobrepeso u obesos demostraron una activación significativamente mayor del músculo temporal asociado con el lado donde se realiza la fuerza máxima de mordida. Conclusión: Nuestros hallazgos sugieren que la fuerza de mordida máxima no está influenciada por el índice de masa corporal y que durante la realización de una fuerza de mordida máxima los sujetos con índice de masa corporal aumentado presentan una mayor activación del músculo temporal asociado al lado donde se realizó la fuerza de mordida máxima.

Polyhydroxybutyrate (PHB) Scaffolds for Peripheral Nerve Regeneration: A Systematic Review of Animal Models.

In the last two decades, artificial scaffolds for nerve regeneration have been produced using a variety of polymers. Polyhydroxybutyrate (PHB) is a natural polyester that can be easily processed and offer several advantages; hence, the purpose of this review is to provide a better understanding of the efficacy of therapeutic approaches involving PHB scaffolds in promoting peripheral nerve regeneration following nerve dissection in animal models. A systematic literature review was performed following the "Preferred Reporting Items for Systematic Reviews and Meta-Analyses" (PRISMA) criteria. The revised databases were: Pub-Med/MEDLINE, Web of Science, Science Direct, EMBASE, and SCOPUS. Sixteen studies were included in this review. Different animal models and nerves were studied. Extension of nerve gaps reconnected by PHB scaffolds and the time periods of analysis were varied. The additives included in the scaffolds, if any, were growth factors, neurotrophins, other biopolymers, and neural progenitor cells. The analysis of the quality of the studies revealed good quality in general, with some aspects that could be improved. The analysis of the risk of bias revealed several weaknesses in all studies. The use of PHB as a biomaterial to prepare tubular scaffolds for nerve regeneration was shown to be promising. The incorporation of additives appears to be a trend that improves nerve regeneration. One of the main weaknesses of the reviewed articles was the lack of standardized experimentation on animals. It is recommended to follow the currently available guidelines to improve the design, avoid the risk of bias, maximize the quality of studies, and enhance translationality.

Masticatory function according to body mass index: part I: kinematic analysis using different food textures / Función masticatoria según índice de masa corporal: parte I: análisis cinemático utilizando diferentes texturas de alimentos

Introduction: Chewing is a learned orofacial function, important in the nutrition process of most mammals. It has been described that it can vary according to the characteristics of the individuals and the characteristics of the food. The aim of this study was to compare the kinematic characteristics of mastication in subjects with different body mass index (BMI), including foods of different hardness in the analysis. Material and Methods: A cross-sectional observational study was conducted. The mastication of 3.7 g of peanut (soft food) and 3.7 g of carrot (hard food) was compared among three study groups formed according to BMI: normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9) and obese (BMI ≥30); each with 7 participants. The kinematics of the masticatory movement were assessed with a 3D Electromagnetic Articulograph, the characteristics analyzed were number of masticatory cycles, masticatory frequency, speed and area of the cycles. Results: No significant differences were noted among the study groups for the number of masticatory cycles, frequency or speed in the two foods studied. It was observed that when chewing carrot, the horizontal area of the masticatory cycles was significantly larger in the obese than in the overweight group. However, when chewing peanuts, this parameter did not present significant differences among the different groups. A comparison of the characteristics of mastication of the two foods revealed that the carrot chewing presented a significantly greater masticatory frequency and speed than the peanut chewing. Conclusion: This study demonstrated that food hardness influences the kinematic characteristics of mastication more than BMI, noting that hard foods are masticated faster and more frequently than soft foods and that masticatory frequency tends to increase with BMI.

Introduction: Chewing is a learned orofacial function, important in the nutrition process of most mammals. It has been described that it can vary according to the characteristics of the individuals and the characteristics of the food. The aim of this study was to compare the kinematic cha-racteristics of mastication in subjects with different body mass index (BMI), including foods of different hardness in the analysis. Material and Methods: A cross-sectional observational study was con- ducted. The mastication of 3.7 g of peanut (soft food) and 3.7 g of carrot (hard food) was compared among three study groups formed according to BMI: normal weight (BMI 18.5-24.9), overweight (BMI 25-29.9) and obese (BMI ?30); each with 7 participants. The kinematics of the masticatory movement were assessed with a 3D Electromagnetic Articulograph, the characteristics analyzed were number of masticatory cycles, masticatory frequency, speed and area of the cycles. Results: No significant differences were noted among the study groups for the number of masticatory cycles, frequency or speed in the two foods studied. It was observed that when chewing carrot, the horizontal area of the masticatory cycles was significantly larger in the obese than in the overweight group. However, when chewing peanuts, this parameter did not present significant differences among the different groups. A comparison of the characteristics of mastication of the two foods revealed that the carrot chewing presented a significantly greater masticatory frequency and speed than the peanut chewing. Conclusion: This study demonstrated that food hardness influences the kinematic characteristics of mastication more than BMI, noting that hard foods are masticated faster and more frequently than soft foods and that masticatory frequency tends to increase with BMI.

Optimal Morphometric Characteristics of a Tubular Polymeric Scaffold to Promote Peripheral Nerve Regeneration: A Scoping Review.

Cellular behavior in nerve regeneration is affected by the architecture of the polymeric nerve guide conduits (NGCs); therefore, design features of polymeric NGCs are critical for neural tissue engineering. Hence, the purpose of this scoping review is to summarize the adequate quantitative/morphometric parameters of the characteristics of NGC that provide a supportive environment for nerve regeneration, enhancing the understanding of a previous study. 394 studies were found, of which 29 studies were selected. The selected studies revealed four morphometric characteristics for promoting nerve regeneration: wall thickness, fiber size, pore size, and porosity. An NGC with a wall thickness between 250-400 µm and porosity of 60-80%, with a small pore on the inner surface and a large pore on the outer surface, significantly favored nerve regeneration; resulting in an increase in nutrient permeability, retention of neurotrophic factors, and optimal mechanical properties. On the other hand, the superiority of electrospun fibers is described; however, the size of the fiber is controversial in the literature, obtaining optimal results in the range of 300 nm to 30 µm. The incorporation of these optimal morphometric characteristics will encourage nerve regeneration and help reduce the number of experimental studies as it will provide the initial morphometric parameters for the preparation of an NGC.

Methods to Characterize Electrospun Scaffold Morphology: A Critical Review.

Electrospun scaffolds can imitate the hierarchical structures present in the extracellular matrix, representing one of the main concerns of modern tissue engineering. They are characterized in order to evaluate their capability to support cells or to provide guidelines for reproducibility. The issues with widely used methods for morphological characterization are discussed in order to provide insight into a desirable methodology for electrospun scaffold characterization. Reported methods include imaging and physical measurements. Characterization methods harbor inherent limitations and benefits, and these are discussed and presented in a comprehensive selection matrix to provide researchers with the adequate tools and insights required to characterize their electrospun scaffolds. It is shown that imaging methods present the most benefits, with drawbacks being limited to required costs and expertise. By making use of more appropriate characterization, researchers will avoid measurements that do not represent their scaffolds and perhaps might discover that they can extract more characteristics from their scaffold at no further cost.

How Fiber Surface Topography Affects Interactions between Cells and Electrospun Scaffolds: A Systematic Review.

Electrospun scaffolds have a 3D fibrous structure that attempts to imitate the extracellular matrix in order to be able to host cells. It has been reported in the literature that controlling fiber surface topography produces varying results regarding cell-scaffold interactions. This review analyzes the relevant literature concerning in vitro studies to provide a better understanding of the effect that controlling fiber surface topography has on cell-scaffold interactions. A systematic approach following PRISMA, GRADE, PICO, and other standard methodological frameworks for systematic reviews was used. Different topographic interventions and their effects on cell-scaffold interactions were analyzed. Results indicate that nanopores and roughness on fiber surfaces seem to improve proliferation and adhesion of cells. The quality of the evidence is different for each studied cell-scaffold interaction, and for each studied morphological attribute. The evidence points to improvements in cell-scaffold interactions on most morphologically complex fiber surfaces. The discussion includes an in-depth evaluation of the indirectness of the evidence, as well as the potentially involved publication bias. Insights and suggestions about dose-dependency relationship, as well as the effect on particular cell and polymer types, are presented. It is concluded that topographical alterations to the fiber surface should be further studied, since results so far are promising.

Time-Integrative Multibiomarker Detection in Triassic-Jurassic Rocks from the Atacama Desert: Relevance to the Search for Basic Life Beyond Earth.

Detecting evidence of life on other planetary bodies requires a certain understanding of known biomarkers and their chemical nature, preservation potential, or biological specificity. In a planetary search for life, carbonates are of special interest due to their known association with life as we know it. On Earth, carbonates serve as an invaluable paleogeochemical archive of fossils of up to billions of years old. Here, we investigated biomarker profiles on three Chilean Triassic-Jurassic sedimentary records regarding our search for signs of past and present life over ∼200 Ma. A multianalytical platform that combines lipid-derived biomarkers, metaproteomics, and a life detector chip (LDChip) is considered in the detection of biomolecules with different perdurability and source-diagnosis potential. The combined identification of proteins with positive LDChip inmunodetections provides metabolic information and taxonomic affiliation of modern/subrecent biosignatures. Molecular and isotopic analysis of more perdurable hydrocarbon cores allows for the identification of general biosources and dominant autotrophic pathways over time, as well as recreation of prevailing redox conditions over ∼200 Ma. We demonstrate how extraterrestrial life detection can benefit from the use of different biomarkers to overcome diagnosis limitations due to a lack of specificity and/or alteration over time. Our findings have implications for future astrobiological missions to Mars.

Main Morphological Characteristics of Tubular Polymeric Scaffolds to Promote Peripheral Nerve Regeneration-A Scoping Review.

The "nerve guide conduits" (NGC) used in nerve regeneration must mimic the natural environment for proper cell behavior. OBJECTIVE: To describe the main morphological characteristics of polymeric NGC to promote nerve regeneration. METHODS: A scoping review was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) criteria in the PubMed, Web of Science, Science Direct, and Scientific Electronic Library Online (SciELO) databases. Primary studies that considered/evaluated morphological characteristics of NGC to promote nerve regeneration were included. RESULT: A total of 704 studies were found, of which 52 were selected. The NGC main morphological characteristics found in the literature were: (I) NGC diameter affects the mechanical properties of the scaffold. (II) Wall thickness of NGC determines the exchange of nutrients, molecules, and neurotrophins between the internal and external environment; and influences the mechanical properties and biodegradation, similarly to NGC (III) porosity, (IV) pore size, and (V) pore distribution. The (VI) alignment of the NGC fibers influences the phenotype of cells involved in nerve regeneration. In addition, the (VII) thickness of the polymeric fiber influences neurite extension and orientation. CONCLUSIONS: An NGC should have its diameter adjusted to the nerve with wall thickness, porosity, pore size, and distribution of pores, to favor vascularization, permeability, and exchange of nutrients, and retention of neurotrophic factors, also favoring its mechanical properties and biodegradability.

Análisis cinemático de la masticación de alimentos duros y blandos en participantes dentados utilizando articulografía electromagnética 3D / Kinematic analysis of hard and soft food mastication in dentate participants using 3D electromagnetic articulography

RESUMEN: Diversos estudios reportan que el tipo de alimento influye directamente en los patrones cinemáticos de la masticación. El objetivo de este estudio fue analizar y comparar los ciclos masticatorios de participantes adultos y completamente dentados durante la masticación de alimentos de diferente textura y dureza (maní y zanahoria) utilizando articulografía electromagnética 3D. Se evaluaron 11 participantes sanos (5 hombres; 6 mujeres), de 31,9 ± 5,2 años de edad. Mediante articulografía electromagnética 3D, se registró la masticación de dos alimentos de prueba (maní y zanahoria). Los datos de movimiento mandibular fueron procesados con MATLAB® y obteniendo diferentes parámetros-frecuencia masticatoria en ciclos por segundo, velocidad de descenso y ascenso mandibular, área de las proyecciones de cada ciclo masticatorio en los tres planos del espacio-que fueron comparados según tipo de alimento y género de los participantes. Se encontraron diferencias estadísticamente significativas entre las áreas de los ciclos masticatorios en el plano horizontal según tipo de alimento, siendo mayor para la masticación de zanahoria (P=,003). Así mismo, se detectaron diferencias estadísticamente significativas entre las áreas sagitales de los ciclos entre hombres y mujeres, siendo mayor en mujeres (P=,042). Nuestros resultados concuerdan con otros estudios que afirman que la textura del alimento influye en las características cinemáticas de los ciclos masticatorios.

SUMMARY: Several studies report that the type of food directly influences the kinematic patterns of mastication. The aim of this study was to analyze and compare the chewing cycles of adult and fully dentate participants during the mastication of foods of different texture and hardness (peanuts and carrots) using 3D electromagnetic articulography. Eleven healthy participants (5 men; 6 women), 31.9 ± 5.2 years old, were evaluated. By means of 3D electromagnetic articulography, the mastication of two test foods (peanuts and carrots) was recorded. The data associated to mandibular movement were processed with MATLAB® obtaining different parameters-masticatory frequency in cycles per second, mandibular descent and ascent rate, area of the projections of each masticatory cycle in the three planes of space-which were compared according to type of food and sex of the participants. Statistically significant differences were found between the areas of the masticatory cycles in the horizontal plane according to type of food, being greater for carrots (P=.003). Likewise, statistically significant differences were detected between the sagittal areas of the cycles between men and women, being greater in women (P=.042). Our results agree with other studies that affirm that the texture of the food influences the kinematic characteristics of the masticatory cycles.

Symmetry of mandibular movements: A 3D electromagnetic articulography technique applied on asymptomatic participants.

STATEMENT OF PROBLEM: Asymmetries in mandibular movements (MMs) can be found in patients with some temporomandibular joint disorders, condylar fracture, or after orthognathic or orthodontic surgery. Quality and symmetry of the MMs should be recorded and analyzed. However, methods for this purpose are limited. PURPOSE: The purpose of this clinical study was to determine the symmetry of MMs on asymptomatic participants by applying an innovative technique based on 3D electromagnetic articulography. MATERIAL AND METHODS: The symmetry of MMs was studied in 16 fully dentate participants (8 men and 8 women). A 3D electromagnetic articulograph was used to register MM by placing a sensor on the interincisal midline of the mandible. The border movements related to the frontal (FP), sagittal (SP), and horizontal (HP) polygons of the Posselt envelope of motion were recorded, as well as masticatory movements. Digital data processing was applied to calculate the trajectory and ranges of mandible displacement, area of the right and left sectors of FP and HP, similarity index between the right and left sectors of FP and HP, and orientation of the individualized masticatory cycles. The Shapiro-Wilk statistical test was used to determine the normality of the sample. To compare the characteristics of the right and left sectors of the polygons, a paired-samples t test (normal distributions) and Wilcoxon test for paired samples (non-normal distributions) were applied (α=.05). RESULTS: No statistically significant differences were found between the right and left sectors of the frontal and horizontal polygons in terms of trajectory (FP, P=.408; HP, P=.417), ranges of movement (FP, P=.736; HP, P=.650), areas (FP, P=.736; HP, P=.233), or orientation of the cycles (P=.506). The similarity index between the morphology of the right and left sectors of the polygons was 68 ±12% for the FP and 67 ±11% for the HP. The areas, trajectories, and ranges had similar values, but they had a different morphology on each side of the polygons. Regarding masticatory cycles, a balanced distribution was observed in terms of their orientation. CONCLUSIONS: The technique used allowed the assessment of symmetry of MM on asymptomatic participants. The evaluated parameters maintain similar values at both left and right sides; however, a different morphology of the trajectories and areas was observed.

Mandibular border movements: The two envelopes of motion.

BACKGROUND: The envelope of motion is a diagrammatic representation of the mandibular border movements. Classically, those movements are carried out eccentrically; starting from the position of maximal intercuspation, the mandible describes an excursion movement until reaching maximal mouth opening. Reverse movements would describe a different path, but up to now concentric development of mandibular border movements has not been considered. Literature states that beyond mandibular border movements limits, no movement is possible. Therefore, it is of great interest to compare both paths-both envelopes of motion-and define the actual limits of mandibular movement. OBJECTIVE: The aim of this study was to compare the geometric characteristics of mandibular border movements carried out eccentrically and concentrically by healthy subjects. METHODS: Sixteen individuals aged between 18 and 27 years, molar class I and with no temporomandibular disorders, participated in the study. Eccentric and concentric mandibular movements were recorded using a 3D electromagnetic articulograph. Data were processed with computational scripts developed in MATLAB. Maximum mouth opening, trajectories, displacement ranges, polygon areas and chewing cycle area/ mandibular border movements area ratio were analysed. RESULTS: The frontal plane showed significant differences in all the parameters evaluated. Higher values were registered in the concentric area of the border movement envelope (P = .008) and in the trajectories on both sides. Statistical differences were observed in polygon areas (P = .006) in the sagittal plane and right ranges (P = .046) in the horizontal plane. CONCLUSION: Concentric mandibular movements revealed significant differences in three-dimensional trajectories in the frontal plane.