Improvement of Model Predictive Current Control Sensing Strategy for a Developed Small Flux-Switching Permanent Magnet Motor.

This paper presents an improved control system for a small flux-switching permanent magnet motor (FSPM) to enhance its performance and torque sensing. The analytical magnetic circuit design was used to determine the related motor parameters, such as the air gap flux density, permeance coefficient (Pc), torque, winding turns, pole number, width, length, magnet geometry, and the current density of FSPM. The electromagnetic analysis of this motor was performed by software (ANSYS Maxwell) to optimize the motor performance. In this study, the performance of FSPM was investigated by the uniform design experimentation (UDE). For the control system, the model predictive current control (MPCC) is currently recognized as a high-performance control strategy, due to its quick response and simple principle. This model contained the nonlinear part of the system, to improve the torque ripple of FSPM. A modified MPCC strategy was proposed to improve the distortion of the current waveform and decrease the computational burden. The new modified control architecture was mainly composed of three parts, such as the estimation of electromotive force (EMF), current prediction, and optimal vector selection/vector duration. When the reference voltage vector was obtained, the three-phase duties were easily determined by the principle of space vector modulation (SVM). The results show the different strategy methods between the newly proposed modified MPCC and traditional proportional integral (PI) controller. In the control of FSPM, a modified MPCC strategy was able to achieve a better performance response and decrease the computational burden. At a low speed of 350 rpm, the proposed modified MPCC can achieve a better dynamic response. The nonlinear problem of the startup speed was also effectively resolved. The torque sensing performance of the simulation and the experimental test value were compared. The torque sensing performance of the simulation and the actual test value were also examined. In this study, the optimization focused not only on the motor design and fabrication, but also on an improved motor control strategy and torque sensing, in order to achieve the integrity of the FSPM system.

A Wireless Monitoring System Using a Tunneling Sensor Array in a Smart Oral Appliance for Sleep Apnea Treatment.

Sleep apnea is a serious sleep disorder, and the most common type is obstructive sleep apnea (OSA). Untreated OSA will cause lots of potential health problems. Oral appliance therapy is an effective and popular approach for OSA treatment, but making a perfect fit for each patient is time-consuming and decreases its efficiency considerably. This paper proposes a System-on-a-Chip (SoC) enabled sleep monitoring system in a smart oral appliance, which is capable of intelligently collecting the physiological data about tongue movement through the whole therapy. A tunneling sensor array with an ultra-high sensitivity is incorporated to accurately detect the subtle pressure from the tongue. When the device is placed on the wireless platform, the temporary stored data will be retrieved and wirelessly transmitted to personal computers and cloud storages. The battery will be recharged by harvesting external RF power from the platform. A compact prototype module, whose size is 4.5 × 2.5 × 0.9 cm³, is implemented and embedded inside the oral appliance to demonstrate the tongue movement detection in continuous time frames. The functions of this design are verified by the presented measurement results. This design aims to increase efficiency and make it a total solution for OSA treatment.

Molecular dynamics study on the nucleation of methane + tetrahydrofuran mixed guest hydrate.

The nucleation of methane (CH4), tetrahydrofuran (THF), and CH4 + THF hydrates are investigated by microsecond MD simulations. These three systems exhibit distinct structural developments in the aqueous phase quantified by the formation of cage structures of hydrogen bonded water molecules. The development of a cluster of cages in the CH4 system is limited by the scarce CH4 molecules in the solution, while in the THF system it is limited by the short lifetime of cages. In the CH4 + THF mixed guest system, a small cluster of caged CH4 molecules can be rapidly stabilized by abundant neighboring cages of THF molecules. Therefore, the induction time of the CH4 + THF mixed guest system is found to be significantly shorter than that of the pure CH4 and pure THF systems. Furthermore, the structure of cages found in the initially formed cage clusters are often different from the typical 5(12)6(n) (n = 0, 2, 3, 4) cages observed in clathrate hydrate systems. The cluster of cages may grow or transform into structure I or II clathrate hydrate in the later stages.

Characterization and evaluation of the differentiation ability of human adipose-derived stem cells growing in scaffold-free suspension culture.

BACKGROUND AIMS: Human adipose-derived stem cells (hADSCs) have become a popular stem cell source because of their abundant supplies, high differentiation ability and the fact that they present few ethical concerns. Suspension culture, a type of three-dimensional culture, is a more suitable model for mimicking cell-cell and cell-extracellular matrix interactions than is two-dimensional monolayer culture. The aim of this study was to determine the effects of suspension culture on the viability and differentiation potential of hADSCs. METHODS: Different densities of hADSCs were cultured in ultra-low-attachment surface plates. The morphology and mean diameter of the resultant aggregates were determined by means of microscopy. The viability of the aggregates was evaluated with the use of 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, inner salt, lactate dehydrogenase and live/dead assays. To detect osteogenesis, chondrogenesis and adipogenesis in hADSCs in suspension culture, cell aggregates were stained to determine cell function, and the expression of specific markers was evaluated through the use of real-time reverse transcriptase-polymerase chain reaction. RESULTS: The hADSCs remained viable in suspension culture and formed cell aggregates. The diameter of the majority of the aggregates was in the range of 50-200 µm, regardless of cell density. The aggregation of the hADSCs served to maintain cell survival. In addition, the results of the histomorphometric and gene expression analyses showed that the hADSCs were more efficiently induced to differentiate into osteoblasts, chondrocytes and adipocytes in suspension culture than in two-dimensional monolayer culture. CONCLUSIONS: Suspension culture can be used to maintain cell viability and contributes to the effective differentiation of hADSCs, providing an alternative cell growth strategy for application to stem cell-based regenerative medicine.

Perceived discrimination, family functioning, and depressive symptoms among immigrant women in Taiwan.

This study examined the moderating effect of family functioning on the relationship between perceived discrimination and depressive symptoms in immigrant women. A total of 239 immigrant women were selected from four administrative regions in Central Taiwan. Questionnaires concerning perceived discrimination, family functioning (including family cohesion and family adaptability), depressive symptoms, and demographic characteristics were completed by either women themselves (N = 120) or their husbands (N = 119). The moderating effect of family functioning on the relationship between perceived discrimination and depression symptoms was analyzed using multiple regression analysis. Findings showed that a higher level of perceived discrimination among immigrant women is associated with more severe depressive symptoms. Family functioning serves as a moderator between the relationship of perceived discrimination and depressive symptoms, but the moderating effect of family adaptability was evident only in data reported by immigrant women. The results indicate that perceived discrimination has negative mental health implications, and also point to the importance of family functioning for depression. Findings suggest that providers should consider addressing immigrant women's mental health needs through declining their psychosocial distress at multiple ecological levels.

Factors associated with intensiveness of use of child preventive health services in Taiwan: a comparative study between cross-cultural immigrant families and native-born families.

OBJECTIVES: To compare intensiveness of use of child preventive health services (CPHS) between cross-cultural immigrant families and native-born families in Taiwan and to explore factors associated with differences in intensiveness of CPHS use. DESIGN: Cross-cultural immigrant families were defined as families where the mother was an immigrant from another southeast Asian country. In native-born families, both parents were Taiwanese-born. Data were collected from 318 immigrant mothers and 340 native-born mothers of children aged 7 years or younger in a cross-sectional survey in central Taiwan. A social determinants framework of health inequities was constructed, and ordinal logistic regression models were used to examine the effect of four domains of intermediary determinants on the relationship between family type and underuse of CPHS: CPHS-related factors, medical-related factors, maternal acculturation factors, and sociodemographic/socioeconomic characteristics. RESULTS: Cross-cultural immigrant families were less likely to intensively use CPHS than native-born families. This difference appeared to be mediated by the greater likelihood of having an older child or a lower educated father in cross-cultural families. CONCLUSION: Findings of this study highlight the importance of promoting health behaviors and combating health inequities and social inequalities for cross-cultural immigrant families in Taiwan from a sociodemographic/socioeconomic and political context.

Baseline Circulating miR-125b Levels Predict a High FIB-4 Index Score in Chronic Hepatitis B Patients after Nucleos(t)ide Analog Treatment.

The regulatory role of microRNAs (miRNAs) in HBV-associated HCC pathogenesis has been reported previously. This study aimed to investigate the association between serum miR-125b and liver fibrosis progression in chronic hepatitis B (CHB) patients after nucleos(t)ide analog (NA) treatment. Baseline serum miR-125b levels and other relevant laboratory data were measured for 124 patients who underwent 12-month NA therapy. Post-12-month NA therapy, serum miR-125, platelet, AST, and ALT levels were measured again for post-treatment FIB-4 index calculation. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors for a higher post-treatment FIB-4 index. Results showed that baseline miR-125b levels were inversely correlated with the post-treatment FIB-4 index (ρ = −0.2130, p = 0.0082). In logistic regression analyses, age (OR = 1.17, p < 0.0001), baseline platelet level (OR = 0.98, p = 0.0032), and ALT level (OR = 1.00, p = 0.0241) were independent predictors of FIB-index > 2.9 post-12-month treatment. The baseline miR-125b level was not significantly associated with a higher post-treatment FIB-4 index (p = 0.8992). In 59 patients receiving entecavir (ETV) monotherapy, the alternation of serum miR-125b in 12 months and age were substantially associated with a higher post-treatment FIB-4 index (>2.9), suggesting that miR-125b is a reliable biomarker for detecting early liver fibrosis under specific anti-HBV NA treatments (e.g., ETV).

A theoretical study of the effect of zero-crossing points within the dispersion map upon a longhaul RZ-DPSK system.

A theoretical study focusing on the effect of zero-crossing points in the dispersion map for the long-haul return-to-zero differential phase shift keying (RZ-DPSK) transmission system had been conducted. Difference of the transmission performance was characterized with regard to number of zero-crossing points within the dispersion map. It was observed that increasing the number of zero-crossing points in the dispersion map combined with the self phase modulation (SPM) caused the performance degradation near the system zero dispersion wavelength.

Numerical study of the performance improvement of the APSK transmission system using zero-nulling method.

We have studied the transmission performance of amplitude and phase shift keying (APSK) format theoretically. As there is a trade-off between the performance of amplitude shift keying (ASK) and phase shift keying (PSK) through the extinction ratio of the ASK format, zero-nulling method to improve the performance of the PSK format had been proposed. A demerit of the zero-nulling method is a reduction of the total capacity. This paper described the effectiveness of the zero-nulling method when the total capacity of the system was identical.

Low power laser irradiation and human adipose-derived stem cell treatments promote bone regeneration in critical-sized calvarial defects in rats.

Both stem cell therapy and physical treatments have been shown to be beneficial in accelerating bone healing. However, the efficacy of combined treatment with stem cells and physical stimuli for large bone defects remains uncertain. The aim of this study was to evaluate the bone regeneration effects of low-power laser irradiation (LPLI) and human adipose-derived stem cell (ADSC) treatments during fracture repair using a comparative rat calvarial defect model. We evaluated the viability of human ADSCs, which were cultured on a porous PLGA scaffold using an MTS assay. The critical-sized calvarial bone defect rats were divided into 4 groups: control group, LPLI group, ADSC group, and ADSC+LPLI group. Bone formation was evaluated using micro-CT. New bone formation areas and osteogenic factor expression levels were then examined by histomorphological analysis and immunohistochemical staining. Our data showed that PLGA had no cytotoxic effect on human ADSCs. Micro-CT analyses revealed that both the LPLI and ADSC groups showed improved calvarial bone defect healing compared to the control group. In addition, the ADSC+LPLI group showed significantly increased bone volume at 16 weeks after surgery. The area of new bone formation ranked as follows: control group < LPLI group < ADSC group < ADSC+LPLI group. There were significant differences between the groups. In addition, both ADSC and ADSC+LPLI groups showed strong signals of vWF expression. ADSC and LPLI treatments improved fracture repair in critical-sized calvarial defects in rats. Importantly, the combined treatment of ADSCs and LPLI further enhances the bone healing process.

Low-power laser irradiation suppresses inflammatory response of human adipose-derived stem cells by modulating intracellular cyclic AMP level and NF-κB activity.

Mesenchymal stem cell (MSC)-based tissue regeneration is a promising therapeutic strategy for treating damaged tissues. However, the inflammatory microenvironment that exists at a local injury site might restrict reconstruction. Low-power laser irradiation (LPLI) has been widely applied to retard the inflammatory reaction. The purpose of this study was to investigate the anti-inflammatory effect of LPLI on human adipose-derived stem cells (hADSCs) in an inflammatory environment. We showed that the hADSCs expressed Toll-like Receptors (TLR) 1, TLR2, TLR3, TLR4, and TLR6 and that lipopolysaccharide (LPS) significantly induced the production of pro-inflammatory cytokines (Cyclooxygenase-2 (Cox-2), Interleukin-1ß (IL-1ß), Interleukin-6 (IL-6), and Interleukin-8 (IL-8)). LPLI markedly inhibited LPS-induced, pro-inflammatory cytokine expression at an optimal dose of 8 J/cm². The inhibitory effect triggered by LPLI might occur through an increase in the intracellular level of cyclic AMP (cAMP), which acts to down-regulate nuclear factor kappa B (NF-κB) transcriptional activity. These data collectively provide insight for further investigations of the potential application of anti-inflammatory treatment followed by stem cell therapy.

Low-power laser irradiation promotes the proliferation and osteogenic differentiation of human periodontal ligament cells via cyclic adenosine monophosphate.

Retaining or improving periodontal ligament (PDL) function is crucial for restoring periodontal defects. The aim of this study was to evaluate the physiological effects of low-power laser irradiation (LPLI) on the proliferation and osteogenic differentiation of human PDL (hPDL) cells. Cultured hPDL cells were irradiated (660 nm) daily with doses of 0, 1, 2 or 4 J⋅cm(-2). Cell proliferation was evaluated by the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay, and the effect of LPLI on osteogenic differentiation was assessed by Alizarin Red S staining and alkaline phosphatase (ALP) activity. Additionally, osteogenic marker gene expression was confirmed by real-time reverse transcription-polymerase chain reaction (RT-PCR). Our data showed that LPLI at a dose of 2 J⋅cm(-2) significantly promoted hPDL cell proliferation at days 3 and 5. In addition, LPLI at energy doses of 2 and 4 J⋅cm(-2) showed potential osteogenic capacity, as it stimulated ALP activity, calcium deposition, and osteogenic gene expression. We also showed that cyclic adenosine monophosphate (cAMP) is a critical regulator of the LPLI-mediated effects on hPDL cells. This study shows that LPLI can promote the proliferation and osteogenic differentiation of hPDL cells. These results suggest the potential use of LPLI in clinical applications for periodontal tissue regeneration.

Low-power GaAlAs laser irradiation promotes the proliferation and osteogenic differentiation of stem cells via IGF1 and BMP2.

Low-power laser irradiation (LPLI) has been found to induce various biological effects and cellular processes. Also, LPLI has been shown to promote fracture repair. Until now, it has been unclear how LPLI promotes bone formation and fracture healing. The aim of this study was to investigate the potential mechanism of LPLI-mediated enhancement of bone formation using mouse bone marrow mesenchymal stem cells (D1 cells). D1 cells were irradiated daily with a gallium-aluminum-arsenide (GaAlAs) laser at dose of 0, 1, 2, or 4 J/cm(2). The lactate dehydrogenase (LDH) assay showed no cytotoxic effects of LPLI on D1 cells, and instead, LPLI at 4 J/cm(2) significantly promoted D1 cell proliferation. LPLI also enhanced osteogenic differentiation in a dose-dependent manner and moderately increased expression of osteogenic markers. The neutralization experiments indicated that LPLI regulated insulin-like growth factor 1 (IGF1) and bone morphogenetic protein 2 (BMP2) signaling to promote cell proliferation and/or osteogenic differentiation. In conclusion, our study suggests that LPLI may induce IGF1 expression to promote both the proliferation and osteogenic differentiation of D1 cells, whereas it may induce BMP2 expression primarily to enhance osteogenic differentiation.