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This article presents the topology and material optimization of an underactuated lower limb robot for gait rehabilitation of stroke survivors. Robot aided lower limb rehabilitation has been studied for the last three decades and a few over-actuated and underactuated robot designs have been proposed in the literature. Over-actuated robots give more controlled motions, whereas underactuated designs allow unconstrained naturalistic motions. Designing an underactuated robot is difficult as it must be lightweight and yet strong enough to scaffold human lower limbs during gait. In this research, a Stephenson III six-bar linkage is modified to be used as single-actuated lower limb robot. The proposed robot design couples two four-bar linkages in a driver-driven mode to provide motions, which are equivalent to the motions from a six-bar linkage. A digital twin of the underactuated robot is developed to conduct in-silico experiments and evaluate the use of three different materials namely, aluminum alloy, structural steel, and fiber reinforced carbon composite. Finite element analysis (FEA) modeling is carried out using the Ansys workbench to assess mechanical performance indices. In order to minimize the overall weight of the robot, structural optimization is carried out using a multi-mode single objective genetic algorithm. Functional and nonfunctional design requirements are formulated as constraints to be used during the optimization experiments. The topology and material optimization presented in this article provides insights into the robot design requirements and the optimization process. As a result of this process, a significant reduction in the robot weight is achieved without compromising the mechanical performance. [ABSTRACT FROM AUTHOR]

Robot-assisted rehabilitation is a rapidly advancing field whereby robotic devices are used for the treatment of disabilities. Mechanism design and actuation of these devices play important roles in the treatment and the non-ergonomic designs may even increase the cardiorespiratory load and cause discomfort leading to further gait disorders. This article identifies crucial design and actuation aspects of gait rehabilitation robots and presents the first intrinsically compliant gait robot design with three actuated and five passive degrees of freedom, alleviating the prevalent issues. The gait robot joints remain aligned with the human anatomical joints during the swing and the stance phases due to the use of special bushes and dampers. The intrinsically compliant actuators on the new gait robot make it safe to work with human subjects. Increased degrees of freedom allow for natural walking dynamics instead of canceling or constraining them. The robot firmware, including the kinematic modeling, is designed using multiple adaptive neuro-fuzzy inference system to save on the computational time of the robot controller. The new robot design is finally validated for its intended use in gait rehabilitation, by employing a fuzzy logic controller and evaluating the position, velocity, and acceleration profiles of its joints. [ABSTRACT FROM AUTHOR]

Background: Patterns of humoral immune responses represent a major hurdle in terms of pig-to-human xenotransplantation approaches. The best-known xenogeneic glycan antigens present in pigs are the αGal (Galili antigen) and the non-human sialic acid Neu5Gc. As there are further differences between porcine and human cellular surface glycosylation, a much broader range of glycan epitopes with xeno-reactive relevance can be anticipated. Therefore, we set out to chemically modify porcine cellular surface glycans in a global approach by applying sodium periodate (NaIO4) oxidation. Methods: Porcine endothelial cells were exposed to oxidation with 1 to 5 mM NaIO4 for different time periods at 37 °C or 4 °C and under static or dynamic conditions. The impact on cellular survival was determined by applying live/dead assays. Oxidation of αGal-epitopes was assessed by fluorescence microscopy-based quantification of isolectin-B4 (IL-B4) staining. Overall immunogenicity of porcine cells was determined by human serum antibody binding. Results: Treatment of porcine endothelial cells and tissues with NaIO4 led to reduced binding of the αGal-specific IL-B4 and/or human serum antibodies. NaIO4 was revealed to be cytotoxic when performed at elevated temperatures and for a prolonged time. However, by applying 2 mM NaIO4 for 60 min at 4 °C, a high extent of cellular viability and a relevant reduction in detectable αGal epitope were observed. No differences were detected irrespectively on whether the cells were oxidized under static or flow conditions. Conclusions: Glycan epitopes on living cells can be oxidized with NaIO4 while maintaining their viability. Accordingly, this strategy holds promise to prevent immune reactions mediated by preformed anti-glycan antibodies. [ABSTRACT FROM AUTHOR]

Abstract Objectives Symmetrical dental occlusion blocking is used in dentistry as a quick diagnostic tool to test for potential influences of the craniomandibular system on body sway and weight distribution. This study presents the changes of body sway and pressure distribution in healthy subjects, free of a temporomandibular dysfunction (TMD). Immediate effects between occlusal blocking and rest position on body sway and body weight distribution in general, as well as for both genders and for four age decades will be evaluated. Materials and methods 725 (396f/329 m) subjects (neither subjective signs of TMD nor acute/chronic complaints in the musculoskeletal system) volunteered (21 to 60 years) while both genders were divided into four age groups according to decades. A pressure measuring platform was used. Body sway and weight distribution were recorded in two dental occlusion conditions (a) in rest position and (b) symmetrical blocking (bicuspid region) by cotton rolls. Results Both, the frontal sway and the sagittal sway reduced by 0.67 mm (t(724) = − 3.9 (p

Abstract Background Temporary occlusal changes and their influence on the upper body statics are still controversially discussed. Furthermore, concrete statements on whether age- or gender-specific differences in neurophysiological reactions exist are missing. Therefore, it is the aim of this study to evaluate the immediate effects of a symmetrical occlusion blocking on the upper body posture. These effects shall be investigated for both genders and for a larger age range. Methods In this study, 800 (407f/393 m) subjects volunteered aged from 21 to 60 years. Both genders were divided into four age groups according to decades. The three-dimensional upper body posture was measured by using the rasterstereography (ABW-Bodymapper). The habitual static posture was measured in two dental occlusion conditions (a) in rest position and (b) symmetrical blocking in the bicuspid region by cotton rolls. Results A significant reduction of the trunk length (0.72 mm; p

Abstract Background Infectious diseases are of great economic importance in commercial pig production, causing both clinical and subclinical disease, with influence on welfare, productivity, and antibiotic use. The causes of these diseases are often multifactorial and laboratory diagnostics are seldom routinely performed. The aim of the present study was to explore the benefits of monthly pathogen monitoring in nursery and finisher herds and to examine association between laboratory results and observed clinical signs, including coughing and diarrhoea. Three monthly samplings were conducted in three different age groups in six nursery and four finisher production units. For each unit, two pens were randomly selected in each age group and evaluated for coughing and diarrhoea events. Furthermore, faecal sock and oral fluid samples were collected in the selected pens and analysed for 18 respiratory and enteric viral and bacterial pathogens using the high-throughput real-time PCR BioMark HD platform (Fluidigm, South San Francisco, USA). Results In total, 174 pens were sampled in which eight coughing events and 77 diarrhoeic events were observed. The overall findings showed that swine influenza A virus, porcine circovirus 2, porcine cytomegalovirus, Brachyspira pilosicoli, Lawsonia intracellularis, Escherichia coli fimbria types F4 and F18 were found to be prevalent in several of the herds. Association between coughing events and the presence of swine influenza A virus, porcine cytomegalovirus (Cq ≤ 20) or a combination of these were found. Furthermore, an association between diarrhoeic events and the presence of L. intracellularis (Cq ≤ 24) or B. pilosicoli (Cq ≤ 26) was found. Conclusions The use of high-throughput real-time PCR analysis for continuous monitoring of pathogens and thereby dynamics of infections in a pig herd, provided the veterinarian and farmer with an objective knowledge on the distribution of pathogens in the herd. In addition, the use of a high-throughput method in combination with information about clinical signs, productivity, health status and antibiotic consumption, presents a new and innovative way of diagnosing and monitoring pig herds and even to a lower cost than the traditional method.

IntroductionEven though many adolescent smokers want to quit, it is difficult to recruit them into smoking cessation interventions. Little is known about which adolescent smokers are currently reached by these measures. In this study we compare participants of a group-based, cognitive behavioral smoking cessation intervention with adolescent smokers who decided against participating.MethodsWithin a non-randomized controlled trial, data of 1053 smokers (aged 11-19) from 42 German secondary schools were analyzed. Of these smokers, 272 were recruited into 47 courses of the intervention. An in-class information session, individually addressing potential participants, and incentives were used as means of recruitment. Personal predictors of participation were analyzed using regression analyses and multivariate path analyses to test for mediation.ResultsIn the path analysis model, nicotine dependence, quit motivation, and a previous quit attempt were directly positively related to participation. Heavier smoking behavior was indirectly positively associated with participation through nicotine dependence and negatively through quit motivation, yielding an overall positive indirect effect. The positive effect of a previous quit attempt on participation was partially mediated through nicotine dependence and quit motivation. The proportion of smoking friends were indirectly positively related to participation, mediated through nicotine dependence.ConclusionsSince adolescents with heavier smoking behavior and stronger nicotine dependence are less likely to undertake a successful unassisted quit attempt, the reach of these young smokers with professional cessation interventions is desirable. Further measures to improve the recruitment of those currently not motivated to quit have to be examined in future studies.