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Closed loop cable robot for large horizontal workspaces
Sergio Juárez-Pérez,Antonio González-Rodriguez,Guillermo Rubio-Gómez,David Rodríguez-Rosa,Erika Ottaviano,Fernando J. Castillo-Garcia 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.2
Inspection and maintenance of civil structures are important issues for sustainability of existing and new infrastructures. Classical approach relies on large human activities eventually performed in unsafe conditions. This paper proposed a non-invasive solution for inspecting horizontal surface such as decks of bridges. The proposal presented here is based in cable-driven robots and allows to inspect large surfaces maintaining a very low vertical occupancy in comparison to the conventional architecture of this kind of robot. Using closed cables loop instead of a set of cables a device with low motorization power and very large workspace is designed and prototyped. As example of control an inverse dynamics technique is applied to control the end-effector where inspection tool is located, e.g., a vision system. Experimental results demonstrate that this novel device allows to inspect large horizontal surfaces, with low motorization and low vertical occupancy.
Mixed-phenotype acute leukemia: suboptimal treatment when the 2008/2016 WHO classification is used
Alan Pomerantz,Sergio Rodriguez-Rodriguez,Roberta Demichelis-Gomez,Georgina Barrera-Lumbreras,Olga Barrales-Benitez,Xavier Lopez-Karpovitch,Alvaro Aguayo-Gonzalez 대한혈액학회 2016 Blood Research Vol.51 No.4
BackgroundDifferent criteria have been used to diagnose mixed-phenotype acute leukemia (MPAL), which has impacted the number of individuals diagnosed with this pathology. Better out-comes have been reported when using acute lymphoblastic leukemia (ALL)-type chemo-therapy in the treatment of MPAL.MethodsWe compared the outcome of 4 groups of patients with MPAL. Group 1 included patients diagnosed using the 2008/2016 World Health Organization (WHO) classification; group 2 included patients diagnosed using the European Group for the Immunological Characterization of Leukemias (EGIL) criteria; group 3 included patients diagnosed using either the EGIL or the 2008/2016 WHO criteria; and group 4 was comprised of patients diagnosed with MPAL using the EGIL classification only.ResultsWe found a significantly worse disease-free survival (groups 1‒4) and overall survival (OS) (groups 2 and 3) when comparing MPAL patients to other acute leukemia (AL) patients. A significantly better OS was obtained in patients (groups 2‒4) treated with ALL-type che-motherapy compared to acute myeloid leukemia (AML)-type regimens.ConclusionIn light of these results, and because a trend (P=0.06) was found with regard to a better OS in group 4 when compared to other AL patients, an argument can be made that the 2008/2016 WHO classification is underpowered to diagnose all MPAL cases, potentially resulting in the suboptimal treatment of some individuals with AL.
Alvarez-Carrizal, Ruth P.,Rodriguez-Garcia, Jose A.,Cortes-Hernandez, Dora A.,Esparza-Vazquez, Sergio J.,Rocha-Rangel, Enrique Techno-Press 2021 Advances in materials research Vol.10 No.4
This research shows the development of a composite material with an alumina matrix reinforced with different percentages of titanium (0.0%, 0.5%, 1%, 2% y 3%) with the intention of analyzing their mechanical and biocompatible properties for its possible application as a biomaterial. Alumina was synthesized using the reaction bonding aluminum oxide (RBAO) methodology. The powders resulting from the milling process had a size distribution ranging from nanometers to 2 microns. By means of X-ray diffraction and differential thermal analysis, it was determined that aluminum oxidizes in both solid and liquid states. It was also found that the alumina formation reaction is complete at 900℃. Using scanning electron microscopy, it was determined that the microstructure has fine grain sizes and homogeneous morphology. Likewise, the elastic modulus and fracture toughness of the composites obtained were determined, results indicate that these properties are higher than the properties of cortical bone. In addition, bioactivity was promoted using the biomimetic method. The results obtained demonstrate that the resulting composite can be used as a biomaterial.
Guillermo Rubio-Gómez,Sergio Juárez,David Rodríguez-Rosa,Enrique Bravo,Erika Ottaviano,Antonio Gonzalez-Rodriguez,Fernando J. Castillo-Garcia 국제구조공학회 2021 Smart Structures and Systems, An International Jou Vol.27 No.2
Cable-driven robots are parallel manipulators in which rigid links are replaced by actuated cables. The end-effector is then supported by a set of cables commanded by motors that are usually placed in a fixed frame. By varying the cables length, it is possible to change the end-effector position and/or orientation. Among the advantages presented by cable robots are they light-weight structure, high energy efficiency and their ability to cover large workspaces since cables are easy to wind. When high-speed operation is not required, a safer solution is to design cable-driven suspended robots, where all vertical components of cables tension are against gravity direction. Cable-driven suspended robots present limited workspace due to the elevated torque requirements for the higher part of the workspace. In this paper, the addition of a passive carriage in the top of the frame is proposed, allowing to achieve a much greater feasible workspace than the conventional one, i.e., with the same size as the desired inspection area while maintaining the same motor requirements. In the opposite, this new scheme presents non-desired vibration during the end-effector maneuvers. These vibrations can be removed by means of a more complex control strategy. Kinematics and dynamics models are developed in this paper. An analysis of sensor system is carried out and a control scheme is proposed for controlling the end-effector pose. Simulation and experimental results show that the feasible workspace can be notoriously increased while end-effector pose is controlled. This new architecture of cable-driven robot can be easily applied for automated inspection and monitoring of very large vertical surfaces of civil infrastructures, such as facades or dams.
Kinetic Study of the Oxidation of ε-Caprolactam Impurities with Permanganate for PZ Estimation
Romero, Arturo,Santos, Aurora,Yustos, Pedro,Rodriguez, Sergio 한국공업화학회 2005 Journal of Industrial and Engineering Chemistry Vol.11 No.1
The permanganate number, PZ, is usually used to characterize the behavior of ε-caprolactam during its polymerization. Impurities in ε-caprolactam that are quickly oxidized by permanganate decrease the PZ value and the associated ε-caprolactam quality. To estimate the value of PZ of an ε-caprolactam containing a mixture of different impurities, a knowledge of the kinetics of the reactions involved is necessary. In this study, we obtained the rate laws of the oxidation of some typical ε-caprolactam impurities with permanganate. We added separately to a commercial ε-caprolactam different amounts, ranging from 1 to 3000 ppm, of both commercial (cyclohexylamine, hexylamine, aniline, ο-toluidine, ρ-toluidine, ε-caprolactone, phenol, nitrobenzene, 2-heptylamine, cyclohexanol, cyclohexene, hexylamide, and cyclohexanone oxime) and synthesized impurities (octahydrophenazine, methyl- δ-valerolactam, cyclohexenone oxime, azocyclohepten-2-one, and cyclohexanone oxime). A parallel reaction network is proposed to describe the reactions between the impurities and permanganate and the kinetic parameters have been calculated by fitting the values of PZ obtained experimentally. The PZ value measured for a mixture of impurities was compared to that predicted by using the kinetic parameters, we obtained; a good agreement exists.
Stability of the prosthetic screws of three types of craniofacial prostheses retention systems
Antonio Gabriel Lanata Flores,Eder Alberto Sigua Rodriguez,Douglas Rangel Goulart,Veber Luiz Bomfim Azevedo,Sergio Olate,José,Ricardo de Albergaria Barbosa 대한구강악안면외과학회 2016 대한구강악안면외과학회지 Vol.42 No.6
Objectives: This study aimed to evaluate the stability of prosthetic screws from three types of craniofacial prostheses retention systems (bar-clip, ball/O-ring, and magnet) when submitted to mechanical cycling. Materials and Methods: Twelve models of acrylic resin were used with implants placed 20 mm from each other and separated into three groups: (1) bar-clip (Sistema INP, São Paulo, Brazil), (2) ball/O-ring (Sistema INP), and (3) magnet (Metalmag, São Paulo, Brazil), with four samples in each group. Each sample underwent a mechanical cycling removal and insertion test (f =0.5 Hz) to determine the torque and the detorque values of the retention screws. A servo-hydraulic MTS machine (810-Flextest 40; MTS Systems, Eden Prairie, MN, USA) was used to perform the cycling with 2.5 mm and a displacement of 10 mm/s. The screws of the retention systems received an initial torque of 30 Ncm and the torque values required for loosening the screw values were obtained in three cycles (1,080, 2,160, and 3,240). The screws were retorqued to 30 Ncm before each new cycle. Results: The sample was composed of 24 screws grouped as follows: bar-clip (n=8), ball/O-ring (n=8), and magnet (n=8). There were significant differences between the groups, with greater detorque values observed in the ball/O-ring group when compared to the bar-clip and magnet groups for the first cycle. However, the detorque value was greater in the bar-clip group for the second cycle. Conclusion: The results of this study indicate that all prosthetic screws will loosen slightly after an initial tightening torque, also the bar-clip retention system demonstrated greater loosening of the screws when compared with ball/O-ring and magnet retention systems.
Warm autoimmune hemolytic anemia: experience from a single referral center in Mexico City
Hernandez-Company Alonso,Anguiano-Alvarez Victor Manuel,Carmona Gonzalez Carlos Amir,Rodriguez-Rodriguez Sergio,Pomerantz Allan,Lopez-Karpovitch Xavier,Tuna-Aguilar Elena Juventina 대한혈액학회 2017 Blood Research Vol.52 No.1
Background: Autoimmune hemolytic anemia (AIHA) is characterized by an autoimmune-mediated de-struction of red blood cells. Warm AIHA (wAIHA) represents 60% of AIHA cases and is associated with the positive detection of IgG and C3d in the direct antiglobulin test (DAT). This study aimed to assess the clinical and laboratorial differences between primary and secondary wAIHA patients from a referral center in Mexico City. Methods: All patients diagnosed with wAIHA in our institution from January 1992 to December 2015 were included and received corticosteroids as the first-line treatment. We analyzed the response to the first-line treatment, relapse-free survival, and time to splenectomy. Results: Eighty-nine patients were included. Secondary wAIHA represented 55.1% of the cases. At diagnosis, secondary wAIHA patients showed a DAT mixed pattern more frequently than primary wAIHA patients (36.7 vs. 17.5%, P<0.001). In the survival analysis, patients with secondary wAIHA had a lower time to response (18 vs. 37 days, P=0.05), median disease-free survival (28.51 vs. 50.95 weeks, P=0.018), and time to splenectomy (43.5 vs. 61 wks, P=0.029) than those with primary wAIHA. Due to economic constraints, ritux-imab was considered as the third-line treatment in only two patients. Conclusion: Secondary wAIHA may benefit from a longer low-dose steroid maintenance period mainly due to its shorter time to relapse and time to splenectomy than primary wAIHA.
Warm autoimmune hemolytic anemia: experience from a single referral center in Mexico City
Hernandez-Company Alonso,Anguiano-Alvarez Victor Manuel,Carmona Gonzalez Carlos Amir,Rodriguez-Rodriguez Sergio,Pomerantz Allan,Lopez-Karpovitch Xavier,Tuna-Aguilar Elena Juventina 대한혈액학회 2017 Blood Research Vol.52 No.1
Background: Autoimmune hemolytic anemia (AIHA) is characterized by an autoimmune-mediated de-struction of red blood cells. Warm AIHA (wAIHA) represents 60% of AIHA cases and is associated with the positive detection of IgG and C3d in the direct antiglobulin test (DAT). This study aimed to assess the clinical and laboratorial differences between primary and secondary wAIHA patients from a referral center in Mexico City. Methods: All patients diagnosed with wAIHA in our institution from January 1992 to December 2015 were included and received corticosteroids as the first-line treatment. We analyzed the response to the first-line treatment, relapse-free survival, and time to splenectomy. Results: Eighty-nine patients were included. Secondary wAIHA represented 55.1% of the cases. At diagnosis, secondary wAIHA patients showed a DAT mixed pattern more frequently than primary wAIHA patients (36.7 vs. 17.5%, P<0.001). In the survival analysis, patients with secondary wAIHA had a lower time to response (18 vs. 37 days, P=0.05), median disease-free survival (28.51 vs. 50.95 weeks, P=0.018), and time to splenectomy (43.5 vs. 61 wks, P=0.029) than those with primary wAIHA. Due to economic constraints, ritux-imab was considered as the third-line treatment in only two patients. Conclusion: Secondary wAIHA may benefit from a longer low-dose steroid maintenance period mainly due to its shorter time to relapse and time to splenectomy than primary wAIHA.