Soft robots are designed to convert stored energy into useful work done. Typically, the soft robot designer starts from a type of soft actuation technology at a component level, rather than from a ...systems engineering level. The characteristics of soft actuation technology may apply constraints on the final system. Bond‐graph theory can be used to graphically represent a model of the energy transfer through a system. Top‐level ion can be in the form of a word bond‐graph and bond‐graph elements can form a lower component level ion. Herein, bond‐graph ion is applied to different soft actuators and their essential characteristics are identified from an energy‐based perspective. Several distinct soft actuation technologies are represented using bond‐graph components for each of the key elements: the energy source, the intermediate energy storage, energy dissipation, energy transformation, and the interaction with the environment. By applying this analysis, the soft robot designer is enabled to select the most suitable actuation technology to fulfill their top‐level system requirements independently of the actuation domain. A systems engineering approach to develop soft robotic systems leads to more everyday products that impact our everyday lives.
Designers of soft robots typically start at a component level rather than from a systems engineering level. Herein, bond‐graph ion is applied to different soft actuators and their essential characteristics are identified. By applying this analysis, the soft robot designer is enabled to select the most suitable actuation technology to fulfill their top‐level system requirements independently of the actuation domain.
Background The benefits of biocompatible peritoneal dialysis (PD) fluids, particularly for residual renal function (RRF), are controversial. Moreover, the clinical effects of a PD regimen consisting ...of different biocompatible PD fluids have not been fully established. Study Design Prospective, randomized, controlled, open-label study. Setting & Participants Patients with end-stage kidney disease newly started on continuous ambulatory PD therapy (N = 150). Intervention A 12-month intervention with 3 biocompatible PD fluids (a neutral-pH, low glucose degradation product, 1.5% glucose solution; a solution with 1.1% amino acid; and a fluid with 7.5% icodextrin) or conventional PD fluid. Outcomes The primary outcome was change in RRF and daily urine volume. Secondary outcomes were peritoneal transport and inflammation markers. Measurements RRF, daily urine volume, serum and dialysate cytokine levels. Results RRF(3.24 ± 1.98 vs 2.88 ± 2.43 mL/min/1.73 m2 ; P = 0.9) and rate of decline in RRF (−0.76 ± 1.77 vs −0.91 ± 1.92 mL/min/1.73 m2 per year; P = 0.6) did not differ between the biocompatible- and conventional-PD-fluid groups. However, patients using the biocompatible PD fluids had better preservation of daily urine volume (959 ± 515 vs 798 ± 615 mL/d in the conventional group, P = 0.02 by comparison of difference in overall change by repeated-measures analysis of variance). Their dialysate-plasma creatinine ratio at 4 hours was higher at 12 months (0.78 ± 0.13 vs 0.68 ± 0.12; P = 0.01 for comparison of the difference in overall change by repeated-measures analysis of variance). They also had significantly higher serum levels of adiponectin and overnight spent dialysate levels of cancer antigen 125, adiponectin, and interleukin 6 (IL-6). No differences between the 2 groups were observed for serum C-reactive protein and IL-6 levels. Limitations Unblinded, relatively short follow-up; no formal sample-size calculations. Conclusions Use of a combination of 3 biocompatible PD fluids for 12 months compared with conventional PD fluid did not affect RRF, but was associated with better preservation of daily urine volume. The biocompatible PD fluids also lead to changes in small-solute transport and an increase in dialysate cancer antigen 125, IL-6, adiponectin, and systemic adiponectin levels, but have no effect on systemic inflammatory response. The clinical significance of these changes, while of great interest, remains to be determined by further studies.
Abstract Background context Facet joint orientation and facet tropism (FT) are presented as the potential anatomical predisposing factors for lumbar degenerative changes that may lead in turn to ...early degeneration and herniation of the corresponding disc or degenerative spondylolisthesis. However, no biomechanical study of this concept has been reported. Purpose To investigate the biomechanical influence of the facet orientation and FT on stress on the corresponding segment. Study design Finite element analysis. Methods Three models, F50, F55, and F60 were simulated with different facet joint orientations (50°, 55°, and 60° relative to coronal plane) at both L2–L3 facet joints. A FT model was also simulated to represent a 50° facet joint angle at the right side and a 60° facet joint angle at the left side in the L2–L3 segment. In each model, the intradiscal pressures were investigated under four pure moments and anterior shear force. Facet contact forces at the L2–L3 segment were also analyzed under extension and torsion moments and anterior shear force. This study was supported by 5000 CHF grant of 2011 AO Spine Research Korea fund. The authors of this study have no topic-specific potential conflicts of interest related to this study. Results The F50, F55, and F60 models did not differ in the intradiscal pressures generated under four pure moments: but under anterior shear force, the F60 and FT models showed increases of intradiscal pressure. The F50 model under extension and the F60 model under torsion each generated an increase in facet contact force. In all conditions tested, the FT model yielded the greatest increase of intradiscal pressure and facet contact force of all the models. Conclusions The facet orientation per se did not increase disc stress or facet joint stress prominently at the corresponding level under four pure moments, but FT could make the corresponding segment more vulnerable to external moments or anterior shear force.
Systemic lupus erythematosus (SLE) is an autoimmune disease with a strong genetic involvement. The susceptibility genes identified so far can only explain a small proportion of disease heritability. ...Through a genome-wide association in a Hong Kong Chinese cohort and subsequent replication in two other Asian populations, with a total of 3164 patients and 4482 matched controls, we identified association of ELF1 (E74-like factor 1) with SLE (rs7329174, OR = 1.26, joint P= 1.47 × 10(-8)). ELF1 belongs to the ETS family of transcription factors and is known to be involved in T cell development and function. Database analysis revealed transcripts making use of three alternative exon1s for this gene. Near equivalent expression levels of distinct transcripts initiated from alternative exon1s were detected in peripheral blood mononuclear cells from both SLE patients and healthy controls. Although a direct association of rs7329174 with the three forms of transcripts for this gene was not detected, these findings support an important role of ELF1 in SLE susceptibility and suggest a potentially tight regulation for the expression of this gene.
The mechanical and thermal properties of nanoclay polymer composites have been experimentally investigated over the last decade. Most of the research has been focused mainly on the control of their ...interplanar structures, which govern the global properties of the composites. In reality, these structures (both exfoliated and intercalated patterns) are hardly achieved through the use of conventional manufacturing process for plastic products. Different sizes of clusters mixed by nanoclays and matrix would be easily formed, particularly in the extrusion of polymer-based components. This paper experimentally studied the hardness and interlaminar shear properties of nanoclay/epoxy composites with different amount of nanoclay content, which formed different sizes of nanoclay/epoxy clusters after mixing in an extruder. The results showed that the micro-hardness of the composites could be enhanced when a small amount of nanoclay was added into the epoxy. However, there was an optimal limit in which the hardness was dropped by continuously increasing the nanoclay content. Microscopic observation on the fracture surfaces showed that the size of the clusters varied with the amount of nanoclays used in the composites. Although previous literatures have reported that the use of nanoclays in polymer-based composites could enhance their mechanical properties, the interlaminar shear test indicated that the short beam shear strength of the composites decreased after adding the nanoclays into the matrix.
Forty-seven patients with severe hepatitis B exacerbation were compared with patients who had mild exacerbation (n = 96) or no exacerbation (n = 96). Seventeen patients (36.2%) died or underwent ...liver transplantation. Preexisting cirrhosis and a prothrombin time (PT) of >30 s were associated with adverse outcome in 60.9% and 87.5% of patients, respectively. The rate of adverse outcome increased to 92.3% when albumin levels of ⩽35 g/L and bilirubin levels of >200 μM were present. Other factors associated with adverse outcomes included peak bilirubin level, peak PT, time to reach peak PT, and the presence of encephalopathy and/or ascites. There was no difference in the frequency of precore mutations in patients with severe or mild exacerbation or without exacerbation. A significantly lower prevalence of core promoter mutants was found in patients with severe exacerbation (50%), compared with those who had mild exacerbation (81.3%; P = .004). Patients with severe exacerbation of hepatitis B with poor prognostic factors should be considered for early liver transplantation.
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