20 research outputs found
Multi-Physical Design and Resonant Controller Based Trajectory Tracking of the Electromagnetically Driven Fast Tool Servo
In this paper, a voice coil motor (VCM) actuated fast tool servo (FTS) system is developed for diamond turning. To guide motions of the VCM actuator, a crossed double parallelogram flexure mechanism is selected featuring totally symmetric structure with high lateral stiffness. To facilitate the determination of the multi-physical parameters, analytical models of both electromagnetic and mechanical systems are developed. The designed FTS with balanced stroke and natural frequency is then verified through the finite element analysis. Finally, the prototype of the VCM actuated FTS is fabricated and experimentally demonstrated to achieve a stroke of ±59.02 μm and a first natural frequency of 253 Hz. By constructing a closed-loop control using proportional–integral–derivative (PID) controller with the internal-model based resonant controller, the error for tracking a harmonic trajectory with ±10 μm amplitude and 120 Hz frequency is obtained to be ±0.2 μm, demonstrating the capability of the FTS for high accuracy trajectory tracking
Effect of textured DLC coatings on tribological properties of titanium alloy under grease lubrication
To improve the tribological properties of titanium alloy surface and promote the functional application of titanium alloy, the synergistic anti-friction and wear-resistant effect of laser micro-textures and diamond-like carbon (DLC) coatings on titanium alloy surface under grease lubrication were investigated in this paper. Micro-textures and DLC coatings were fabricated on the surface of titanium alloy by Nd:YAG laser and magnetron sputtering technology. Effects of different surface treatment methods and micro-textures parameters on tribological properties of titanium alloy samples was studied. The results showed that, compared with the smooth titanium alloy sample, the friction coefficient of micro-textured sample, DLC coated sample and textured DLC coated sample decreased by 43.7%, 75.8%, 80.6% respectively. The surface of textured coated titanium alloy had the best tribological properties with a friction coefficient of 0.0799. The wear on the surface of the titanium alloy sample treated by laser micro-textures and DLC coatings was obviously improved. Compared with the severe adhesive wear on the surface of the titanium alloy sample, the surface of the textured coated titanium alloy sample was slightly scratched, and the wear volume was decreased by 97.5%. Meanwhile, DLC coatings with 30% textures density and 20 μ m textures depth showed the best anti-friction effect as well as the optimal hydrodynamic lubrication effect. Under the condition of grease lubrication, the surface of textured DLC coated titanium alloy substrate presented favorable anti-friction and wear-resistance effects, which revealed that reasonable micro-textures density and depth could more effectively exert the lubricating and anti-friction properties of textured DLC coatings
Serum IFN-γ levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis
Abstract Background To explore the mechanism of the different clinical efficacies of mesenchymal stem cell transplantation (MSCT) and identify a possible serum biomarker for predicting the therapeutic effect of MSCT in rheumatoid arthritis (RA) patients. Methods A total of 105 patients with persistently active RA and poor responses to traditional medication were randomly divided into MSCT and control groups. Outcomes were evaluated according to the 28-joint Disease Activity Score and Health Assessment Questionnaire, serological indicators, regulatory T cell (Treg) to T helper 17 (Th17) cell ratio, and inflammatory cytokine levels. Twelve weeks after MSCT, the outcomes of the MSCT group were evaluated according to the European League against Rheumatism response criteria. Patients with a good or moderate response were added to the response group, and those with no response were added to the no-response group. Results No serious adverse events were reported for either MSCT subgroup (28 in the response group and 24 in the no-response group). The therapeutic effects lasted for 48 weeks without continuous administration. Notably, a transient increase in serum IFN-γ (>2 pg/ml) levels was observed in the response group, but not in the no-response group. Furthermore, an increase in IL-10 levels and the Treg/Th17 ratio and a reduction in IL-6 levels appeared 2–3 weeks after the transient IFN-γ increase. Conclusions Allogeneic MSCT is safe and feasible, and we propose high serum IFN-γ levels as a potent biomarker for predicting MSCT response. Trial registration chictr.org, ChiCTR-ONC-16008770. Registered 3 July 2016, http://www.chictr.org.cn/showproj.aspx?proj=1482
The impact of education/training on nurses caring for patients with stroke: a scoping review
Abstract Background Stroke survivors have complex needs that necessitate the expertise and skill of well-trained healthcare professionals to provide effective rehabilitation and long-term support. Limited knowledge exists regarding the availability of specialized education and training programs specifically designed for nurses caring for stroke patients. Aim This review aims to assess the content and methods of training for nurses caring for stroke patients, examine its impact on both nurses and patients, and identify key facilitators and barriers to its implementation. Methods We conducted a comprehensive scoping review by reviewing multiple databases, including PubMed, Cumulative Index to Nursing and Allied Health Literature, PsycINFO, Embase, Web of Science, Scopus, ProQuest Dissertations and Theses, Google Scholar, and Cochrane databases. Data extraction and narrative synthesis were performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Results Seventeen articles were included in this review. We found that education/training not only enhanced patients' self-care abilities, nursing outcomes, and satisfaction, but also had a positive impact on the knowledge, skills, and practices of nurses. The obstacles to education/training included feasibility and cost-effectiveness, while the driving factors were management support and participation, professional education/training, and controlled environment creation. Conclusions This review highlights the crucial role of education/training in enhancing stroke care provided by nurses. Effective education/training integrates various educational methods and management support to overcome implementation barriers and optimize clinical practice benefits. These findings indicate the necessity of universal and consistent stroke education/training for nurses to further improve patient outcomes in stroke care
Effects of W/Co co-doping on the structural, multiferroic, dielectric and optical properties of filled tungsten bronze Ba4Sm2Fe2Nb8O30 ceramics
The structural, magnetic, ferroelectric, dielectric, magneto-dielectric and optical properties of W/Co co-substituted tungsten bronze Ba4Sm2Fe2Nb8-3x(W2Co)xO30 (0 ≤ x ≤ 0.3) ceramics were studied in detail. All the samples can be indexed with the tetragonal structure with the space group of P4bm. The room-temperature ferromagnetism with rather high ferromagnetic Curie temperature Tc was obtained in all compositions. The co-doping of W/Co ions obviously optimized the ferromagnetism and ferroelectricity. The composition x  = 0.2 showed a superior multiferroicity with the remnant magnetization Mr of 0.15 emu/g and the remnant polarization Pr of 2.1μC/cm2 as well as the Tc of 886 K. The low-temperature relaxation was related to the thermal process of oxygen vacancies, while the another one around 300 K was ascribed to the localized hopping of electrons. The relative increment of magneto-dielectric constant (MDC) obeyed with the square term of magnetization in Ginzburg-Landau theory, implying the existence of intrinsic magneto-electric coupling effect. A relatively large MDC of 0.17 % was achieved in pure sample. In addition, two direct inter-band transitions with the narrow band gaps of ∼2.0 eV and ∼2.5 eV were demonstrated
MOESM3 of Serum IFN-ÃŽÅ‚ levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis
Additional file 3: Figure S1. IFN-ÃŽÅ‚ increases IDO expression of MSC in vitro
MOESM1 of Serum IFN-ÃŽÅ‚ levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis
Additional file 1: Table S1. Clinical and demographic characteristics of the patients enrolled in the study
MOESM2 of Serum IFN-ÃŽÅ‚ levels predict the therapeutic effect of mesenchymal stem cell transplantation in active rheumatoid arthritis
Additional file 2. Source and preparation of MSCs
Additional file 1 of The impact of education/training on nurses caring for patients with stroke: a scoping review
Additional file 1. Appendix A provides the full list of search terms