bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex Ratio at Birth: A Retrospective Audit of the Birth Records of a Nigerian Hospital
Authors: Onyiriuka AN , Ikeanyi EM
Published: August 2015

Aims: The aim was to determine the sex ratio at birth in St Philomena Catholic Hospital (SPCH), Benin City, south-south, Nigeria and to assess its relationship with birth order and maternal age. Methods: In this retrospective cohort study, the records of all deliveries at St Philomena Catholic Hospital (SPCH), Benin City, Nigeria between 1st January, 2005 and 31st December, 2014 (10 years) were retrieved and analyzed. Stillbirths and infants with ambiguous genitalia were excluded in the analysis. Results: The total number of live-births during the 10-year period under review was 13,702 and these consisted of 7,007 males and 6,695 females, resulting in a sex ratio of 104.7:100 (approximately 1.05) at birth. The yearly sex ratios varied from 1.01 to 1.14. The maternal age and the birth order significantly influenced offspring sex ratio at birth (p < 0.001). The highest sex ratio was found among third-birth-order offspring and the lowest was found among offspring of fifth-birth order and above. Offspring of mothers aged 25-29 years had the highest sex ratio and those of mothers aged 40 years and above had the lowest sex ratio. Conclusions: The sex ratio at birth in south-south Nigeria is comparable to values obtained from south-west Nigeria but lower than that obtained from north-west Nigeria. The birth order and maternal age influenced the offspring sex ratio at birth.
Males in Dietetics, What Can Be Learned from the Nursing Profession? A Narrative Review of the Literature
Authors: Gheller Brandon , Lordly Daphne
Published: August 2015

In Canada 95% of dietitians are female despite serving a sex-diverse population. Literature examining why there are so few male dietitians is limited. However, nursing, like dietetics, is female dominated but has a large body of literature examining sex diversity within the profession. Therefore, a narrative literature review was conducted to find articles that examined the following questions: (i) What are the barriers and motivating factors for prospective male nursing students? and (ii) What are the perceived sex-based challenges that male nursing students encounter during their education? A total of 38 articles were included in the final review and the results are presented under the following headings: barriers, motivators, and educational experiences both in the classroom and during clinical rotations. The review outlines the current state of knowledge regarding sex as it relates to nursing and how this information compares with the current dietetics literature. Conclusions and recommendations are drawn about what changes could be made in dietetic education immediately and how further research could provide insight towards reducing the barriers and facilitating easier access to dietetics education for males.
Moving Forward with School Nutrition Policies: A Case Study of Policy Adherence in Nova Scotia
Authors: McIsaac Jessie-Lee D. , Shearer Cindy L. , Veugelers Paul J. , Kirk Sara F.L.
Published: August 2015

Many Canadian school jurisdictions have developed nutrition policies to promote health and improve the nutritional status of children, but research is needed to clarify adherence, guide practice-related decisions, and move policy action forward. The purpose of this research was to evaluate policy adherence with a review of online lunch menus of elementary schools in Nova Scotia (NS) while also providing transferable evidence for other jurisdictions. School menus in NS were scanned and a list of commonly offered items were categorized, according to minimum, moderate, or maximum nutrition categories in the NS policy. The results of the menu review showed variability in policy adherence that depended on food preparation practices by schools. Although further research is needed to clarify preparation practices, the previously reported challenges of healthy food preparations (e.g., cost, social norms) suggest that many schools in NS are likely not able to use these healthy preparations, signifying potential noncompliance to the policy. Leadership and partnerships are needed among researchers, policy makers, and nutrition practitioners to address the complexity of issues related to food marketing and social norms that influence school food environments to inspire a culture where healthy and nutritious food is available and accessible to children.
How do Student Clients of a University-based Food Bank Cope with Food Insecurity?
Authors: Farahbakhsh Jasmine , Ball Geoff D.C. , Farmer Anna P. , Maximova Katerina , Hanbazaza Mahitab , Willows Noreen D.
Published: August 2015

Purpose: To describe the food security status, food insecurity coping strategies, characteristics, and experiences of student clients of the Campus Food Bank (CFB) at the University of Alberta in Edmonton, Alberta, Canada.

Methods: A convenience sample of 58 students completed a survey from April 2013 to April 2014. Food security status was determined using the “Adult Food Security Survey Module”.

Results: Ninety percent of CFB student clients who participated in this study were food insecure, which included both moderately and severely food insecure groups. The most prevalent coping strategies for food insecurity included applying for a loan or bursary (86.2%), seeking employment or working more hours (84.5%), and purchasing food using a credit card (77.6%). Participants were a diverse mix of students, including graduate students (50.0%), international students (46.6%), and caregivers of children (24.1%). The most common primary sources of income were government student loans (29.3%) and research assistantships (20.7%). Most participants (82.8%) liked the food they received from the food bank.

Conclusions: Food insecurity is highly prevalent among student clients of this university-based food bank. Students used a variety of coping strategies to increase their disposable income, highlighting the need for additional strategies to alleviate food insecurity among vulnerable students.
Editorial
Authors: Welch Penny , Wright Susan
Published: August 2015

Welcome to this issue of Learning and Teaching: The International Journal of Higher Education in the Social Sciences. Important social aspects of contemporary higher education are addressed in this issue by authors from a number of countries and social science disciplines. These range from learning and teaching concepts of capitalism and alienation, to the impacts of computerised university administration, the systematic ways certain categories of students fall through cracks in the academic pipeline, and how to reintroduce social activism into a ‘professionalised’ curriculum and teach social justice through international study visits.
Audit culture and the infrastructures of excellence: On the effects of campus management technologies
Authors: Vonderau Asta
Published: August 2015

Drawing upon ethnographic data, this article investigates the effects of a new online campus management system in one of the largest universities in Germany. It shows the various ways in which this technological innovation influenced students', teachers' and administrative personnel's relations and everyday working practices and how it is influential in the reorganisation of university structures. The online management system is regarded as an important part of an emerging infrastructure of excellence, which materialises the changing understanding of qualitative studies and teaching. Findings show that the online management supports standardised and economised study, teaching and administrative practices and silences creativity and flexibility. However, these standardisations are negotiated and questioned by the actors involved.
A comparison study on the flexural strength and compressive strength of four resin-modified luting glass ionomer cements
Authors: Li Yuan , Lin Hong , Zheng Gang , Zhang Xuehui , Xu Yongxiang
Published: August 2015

Abstract

The purpose of this study is to compare the differences in flexural strength and compressive strength between four resin-modified luting glass ionomer cements that are commonly used in clinics. Furthermore, this study investigates the influence of curing mode on the flexural strength and compressive strength of dual-cured resin-modified glass ionomer cements. Initially, flexural strength and compressive strength test specimens were prepared for RL, NR, GCP, and GCC. The RL group and NR group were cured by the light-curing mode and chemical-curing mode. Five specimens were prepared for each test group, and the flexural strength and compressive strength of each were measured. Data were analyzed by one-way ANOVA with SPSS 13.0. Furthermore, the fracture morphology of the flexural specimens was observed by SEM. The result of the mean flexural strength of each group is as follows: the NR light-cured group > NR chemically-cured group > GCP > RL light-cured group > GCC > RL chemically-cured group. More specifically, the flexural strength of the NR light-cured group ((42.903±4.242) MPa) is significantly higher (P<0.05) than those of the other groups, and in addition, the flexural strength of the light-curing mode is significantly higher (P<0. 05) than that of both the NR and RL chemically-cured groups. The result of the mean compressive strength of each group is as follows: GCP > NR chemically-cured group > NR light-cured group > GCC > RL light-cured group > RL chemically-cured group. Although the compressive strengths of the NR and GCP groups are higher than those of the GCC and RL groups, there are no significant differences (P>0.05) between NR and GCP, and no significant differences between GCC and RL. Furthermore, there are no significant differences (P>0.05) between the two curing modes on NR and RL. From the present study, it can be concluded that NR has superior flexural strength and compressive strength compared to the other three materials. Additionally, the curing mode can affect the flexural strength of dual-cured RMGIC because with the light-curing mode, the flexural strength is higher than with the chemical-curing mode. Therefore, light curing is an essential procedure when using dual-cured RMGIC in clinics.
Color difference threshold determination for acrylic denture base resins
Authors: Ren Jiabao , Lin Hong , Huang Qingmei , Liang Qifan , Zheng Gang
Published: August 2015

Abstract

This study aimed to set evaluation indicators, i.e., perceptibility and acceptability color difference thresholds, of color stability for acrylic denture base resins for a spectrophotometric assessing method, which offered an alternative to the visual method described in ISO 20795-1:2013. A total of 291 disk specimens 50±1 mm in diameter and 0.5±0.1 mm thick were prepared (ISO 20795-1:2013) and processed through radiation tests in an accelerated aging chamber (ISO 7491:2000) for increasing times of 0 to 42 hours. Color alterations were measured with a spectrophotometer and evaluated using the CIE L*a*b* colorimetric system. Color differences were calculated through the CIEDE2000 color difference formula. Thirty-two dental professionals without color vision deficiencies completed perceptibility and acceptability assessments under controlled conditions in vitro. An S-curve fitting procedure was used to analyze the 50:50% perceptibility and acceptability thresholds. Furthermore, perceptibility and acceptability against the differences of the three color attributes, lightness, chroma, and hue, were also investigated. According to the S-curve fitting procedure, the 50:50% perceptibility threshold was 1.71ΔE00 (r2=0.88) and the 50:50% acceptability threshold was 4.00 ΔE00 (r2=0.89). Within the limitations of this study, 1.71/4.00 ΔE00 could be used as perceptibility/acceptability thresholds for acrylic denture base resins.
Thermal treatment of expanded polytetraflu-oroethylene (ePTFE) membranes for reconstruction of a valved conduit
Authors: Zhu Guangyu , Yuan Qi , Hock Yeo Joon , Nakao Masakazu
Published: August 2015

Abstract

The unique micro porous structure of expanded polytetrafluoroethylene (ePTFE) that allows bio-integration for fixation, as well as overall mechanical integrity make it used successfully in a number of biomedical and clinical applications, which include the reconstruction of the pulmonary valve in in right ventricular outflow tract reconstruction (RVOT) operations. The objective of this study was to determine the effects of the thermal treatment on physical and mechanical properties of ePTFE membranes. ePTFE sheets were cut into 16 rectangle strips (10 mm by 60 mm) and evenly separated into 4 groups. One group was the blank control (group A), while the rest of the three groups (group B to D) were heated to 350°C and cooled to 24°C at different cooling rates (10°C/min, 20°C/min and rapid ambient air cooling) in a temperature controlled atmosphere. The mechanical and morphological characteristics of all the samples were tested using a tensile test machine and a scanning electron microscopy (SEM). The results show that the elastic modulus of group B to D was 24.95%, 33.45% and 72.76% higher than group A. The percentage elongation of groups B to D was found to be between 2.3% and 40.45% lower than group A. The proportion of pores in the ePTFE membrane was reduced following the thermal treatment. There were no morphology differences observed between groups B to D. In summary, the selection of cooling rate was important for preserving the mechanical properties of ePTFE membranes under thermal treatment. These findings may provide useful information for the preparation of molded ePTFE valve in RVOT operations.
Preparation of polysaccharide loaded collagen membrane with anti-oxidative activity
Authors: Shu Zibin , Ding Shengli , He Xiaohong , Dai Xuemei , Xiao Qian , Yang Min , Leng Xue , Ma Yanshun , Yang Hua
Published: August 2015

Abstract

The scavenging activity of polysaccharides from Lycium barbarum, Lentinus edodes and Ganoderma Lucidum Karst to DPPH free radicals was investigated. It was found that among the three polysaccharides, Lycium barbarum polysaccharides (LBP) exhibits the best scavenging activity. Polysaccharide loaded collagen membranes were prepared by mixing LBP with collagen, starch, glycerol, sodium carboxymethyl cellulose and glutaraldehyde. In vitro drug release from membranes was evaluated. With increasing the immersion time, the release rate first increases and then slows down. Meanwhile, the scavenging activity to DPPH radicals exhibits similar variation, in agreement with a good release effect of the membrane. The optimal formulation of collagen membrane and preparation parameters were obtained considering the overall properties and the scavenging activity to radicals.
Evaluating formability of LCP plate for sacral fractures with one step inverse forming finite element analysis
Authors: Li Xiaoda , Zhang Xiangkui , Hu Ping , Liu Weijie , Shen Guozhe , Zhan Xianghui
Published: August 2015

Abstract

The locking compression plate fixation treatment for the unstable sacral fractures is simple and effective, with less trauma and complications. Some locking compression plate parts have been made of high-strength Plate manufactured by hot stamping process since the demand for lightweight biomedical materials. Finite Element (FE) method of One-Step inverse forming based on deformation theory is the tool to evaluate the formability of locking compression plate panel quickly in initial design for reducing costs and development cycle of Plate. But current one-step inverse forming methods are all suitable for cold stamping, not hot-stamping. This paper proposed one-step inverse forming method and workflow for hot-stamping of locking compression Plate. And the B pillar of a sacral bone was simulated and its computing result was compared with experimental value. The result shows that the proposed method in this paper can quickly evaluate high temperature formability of high-strength Plate. And the method is proposed to be used in initial design.
Evaluation of the novel three-dimensional porous poly (L-lactic acid)/nano-hydroxyapatite composite scaffold
Authors: Huang Jianghong , Xiong Jianyi , Liu Jianquan , Zhu Weimin , Chen Jielin , Duan Li , Zhang Jufeng , Wang Daping
Published: August 2015

Abstract

To determine the optimal ratio of nano-hydroxyapatite (n-HA) to polylactic acid (PLLA) in the novel three-dimensional porous PLLA/n-HA composite scaffolds, low-temperature rapid prototyping technology was employed to fabricate the composite materials with different n-HA contents. Mechanical properties and degradation behaviors of the composites were examined, and the scaffold microstructure and n-HA dispersion were observed by scanning electron microscope (SEM). Mechanical tests demonstrated that the tensile strength of the composite material gradually decreased with an increase in n-HA content. When the n-HA content reached 20 wt%, the bending strength of the composite material peaked at 138.5 MPa. SEM images demonstrated that the optimal content of n-HA was 20 wt% as the largest interconnected pore size that can be seen, with a porosity as high as 80%. In vitro degradation experiments demonstrated that the pH value of the material containing solution gradually decreased in a time-dependent manner, with a simultaneous weakening of the mechanical properties. In vitro study using rat osteoblast cells showed that the composite scaffolds were biocompatible; the 20 wt% n-HA scaffold offered particular improvement to rat osteoblast cell adhesion and proliferation compared to other compositions. It was therefore concluded that 20 wt% n-HA is the optimal nano-hydroxyapatite (n-HA) to polylactic acid (PLLA) ratio, with promise for bone tissue engineering.
Soft tissue modelling with conical springs
Authors: Omar Nadzeri , Zhong Yongmin , Jazar Reza N. , Subic Aleksandar , Smith Julian , Shirinzadeh Bijan
Published: August 2015

Abstract

This paper presents a new method for real-time modelling soft tissue deformation. It improves the traditional mass-spring model with conical springs to deal with nonlinear mechanical behaviours of soft tissues. A conical spring model is developed to predict soft tissue deformation with reference to deformation patterns. The model parameters are formulated according to tissue deformation patterns and the nonlinear behaviours of soft tissues are modelled with the stiffness variation of conical spring. Experimental results show that the proposed method can describe different tissue deformation patterns using one single equation and also exhibit the typical mechanical behaviours of soft tissues.
The application of multi-frequency fringe projection profilometry on the measurement of biological tissues
Authors: Jiang Chao , Jia Shuhai , Xu Yong , Bao Qingchen , Dong Jun , Lian Qin
Published: August 2015

Abstract

A volume of research has been performed on the optical surface profilometry in the field of biomedicine and the optical system with the phase-measuring method becomes the main emphasis of the research. In this research, a brand new fringe projection profilometry with multiple frequencies is described for measuring the biological tissue. A pork liver, as an object, is regarded as a human organ and a DMD projector is used to generate the multi-frequency fringe patterns. The wrapped phase maps are obtained by means of the five-step phase shifting method and calculated via a peak searching algorithm in which the process of measuring the point on the surface of the object is independent so that the step of unwrapping the phase can be avoided. The final results given are acceptable which confirm this method and suggest its enormous potential for the biomedical measurements.
A study on new method of noninvasive esophageal venous pressure measurement based on the airflow and laser detection technology
Authors: Hu Chenghuan , Huang Feizhou , Zhang Rui , Zhu Shaihong , Nie Wanpin , Liu Xunyang , Liu Yinglong , Li Peng
Published: August 2015

Abstract

Using optics combined with automatic control and computer real-time image detection technology, a novel noninvasive method of noncontact pressure manometry was developed based on the airflow and laser detection technology in this study. The new esophageal venous pressure measurement system was tested in-vitro experiments. A stable and adjustable pulse stream was produced from a self-developed pump and a laser emitting apparatus could generate optical signals which can be captured by image acquisition and analysis system program. A synchronization system simultaneous measured the changes of air pressure and the deformation of the vein wall to capture the vascular deformation while simultaneously record the current pressure value. The results of this study indicated that the pressure values tested by the new method have good correlation with the actual pressure value in animal experiments. The new method of noninvasive pressure measurement based on the airflow and laser detection technology is accurate, feasible, repeatable and has a good application prospects.
Research on the multiple linear regression in non-invasive blood glucose measurement
Authors: Zhu Jianming , Chen Zhencheng
Published: August 2015

Abstract

A non-invasive blood glucose measurement sensor and the data process algorithm based on the metabolic energy conservation (MEC) method are presented in this paper. The physiological parameters of human fingertip can be measured by various sensing modalities, and blood glucose value can be evaluated with the physiological parameters by the multiple linear regression analysis. Five methods such as enter, remove, forward, backward and stepwise in multiple linear regression were compared, and the backward method had the best performance. The best correlation coefficient was 0.876 with the standard error of the estimate 0.534, and the significance was 0.012 (sig. <0.05), which indicated the regression equation was valid. The Clarke error grid analysis was performed to compare the MEC method with the hexokinase method, using 200 data points. The correlation coefficient R was 0.867 and all of the points were located in Zone A and Zone B, which shows the MEC method provides a feasible and valid way for non-invasive blood glucose measurement.
Automated detection of cardiac phase from intracoronary ultrasound image sequences
Authors: Sun Zheng , Dong Yi , Li Mengchan
Published: August 2015

Abstract

Intracoronary ultrasound (ICUS) is a widely used interventional imaging modality in clinical diagnosis and treatment of cardiac vessel diseases. Due to cyclic cardiac motion and pulsatile blood flow within the lumen, there exist changes of coronary arterial dimensions and relative motion between the imaging catheter and the lumen during continuous pullback of the catheter. The action subsequently causes cyclic changes to the image intensity of the acquired image sequence. Information on cardiac phases is implied in a non-gated ICUS image sequence. A 1-D phase signal reflecting cardiac cycles was extracted according to cyclical changes in local gray-levels in ICUS images. The local extrema of the signal were then detected to retrieve cardiac phases and to retrospectively gate the image sequence. Results of clinically acquired in vivo image data showed that the average inter-frame dissimilarity of lower than 0.1 was achievable with our technique. In terms of computational efficiency and complexity, the proposed method was shown to be competitive when compared with the current methods. The average frame processing time was lower than 30 ms. We effectively reduced the effect of image noises, useless textures, and non-vessel region on the phase signal detection by discarding signal components caused by non-cardiac factors.
Design improvement and dynamic finite element analysis of novel ITI dental implant under dynamic chewing loads
Authors: Cheng Yung-Chang , Lin Deng-Huei , Jiang Cho-Pei , Lee Shyh-Yuan
Published: August 2015

Abstract

The main aim of this article was to introduce the application of a uniform design for experimental methods to drop the micromotion of a novel ITI dental implant model under the dynamic loads. Combining the characteristics of the traditional ITI and Nano-Tite implants, a new implant with concave holes has been constructed. Compared to the traditional ITI dental implant model, the micromotion of the new dental implant model was significantly reduced by explicit dynamic finite element analysis. From uniform design of experiments, the dynamic finite element analysis method was applied to caluculated the maximum micromotion of the full model. Finally, the chief design in all the experiment simulations which cause the minimum micromotion is picked as the advanced model of the design. Related to the original design, which was associated with a micromotion of 45.11 μm, the micromotion of the improved version was 31.37 μm, for an improvement rate of 30.5%.
Experimal study of young male drivers’ responses to vehicle collision using EMG of lower extremity
Authors: Gao Zhenhai , Li Chuzhao , Hu Hongyu , Zhao Hui , Chen Chaoyang , Yu Huili
Published: August 2015

Abstract

A driver’s response to a front-coming vehicle collision consists of braking reaction time and braking behavior. The purpose was to investigate drivers’ responses at different speeds, relative distances, and particularly the behavior on the accelerator at the collision moment. Twelve young men participated in driving simulator tests. Vehicle parameters and electromyograms (EMGs) of the drivers’ tibialis anterior muscles were recorded and responses were analyzed. The drivers’ braking reaction time windows were divided into pre-motor time, muscle activation time, accelerator release time, and movement time. By comparing the reaction times and collision times, braking behaviors were investigated. It was found that movement times (r = -0.281) decreased with speed. Pre-motor times (r = 0.326) and muscle activation times (r = 0.281) increased with relative distance. At the collision moment, the probability of the driver’s lower extremity being on the accelerator, in the air, and on the brake pedal was 7.4%, 18.9%, and 73.7%, respectively. With higher speeds and smaller distances, the lower extremity was more likely to be in the air or even on the accelerator in different muscle activation states. The driver will collide in normal driving postures which muscles are not or not fully activated in very urgent situation.
Application of multi-output support vector regression on EMGs to decode hand continuous movement trajectory
Authors: Tian Pan , Hu Jie , Qi Jin , Xia Peng , Peng Ying-Hong
Published: August 2015

Abstract

Applications of neural machine interfaces have received increased attention during the last decades. It is crucial to realize the continuous control of prosthetic devices based on biological signals. In order to deal with the highly nonlinear relationship between the Electromyography (EMG) signals and motion, this study presents a novel decoding approach which employs multi-output support vector regression (M-SVR). The proposed M-SVR is compared with other popular regression techniques and the experimental results demonstrate the effectiveness of M-SVR in hand continuous movement trajectory reconstruction.
Development of an integrated digital hand grip dynamometer and norm of hand grip strength
Authors: Chang Ho , Chen Chih-Hao , Huang Tung-Sun , Tai Chun-Yen
Published: August 2015

Abstract

This study designs and fabricates a novel integrated digital hand grip dynamometer and analyzes collected grip strength data. The dynamometer directly stores collected data in a computer, unlike those on the market that cannot directly store information. A strain gauge load cell is used as a force sensor. The dynamometer is designed to maximize ergonomics. Excitation voltage of the load cell is 5 V, and a 9 V battery supplies power to its circuit. The signal receiver is National Instruments (NI) data acquisition (DAQ) card that transmits signals to the computer. The operation system is designed using LabView. This study assesses the correlation between variables of collected data. The correlation coefficients for height, weight and palm length were 0.793, 0.609 and 0.715, respectively, indicating that variables were moderately to strongly correlate with grip strength.
Study of cervical muscle response and injury of driver during a frontal vehicle collision
Authors: Gao Zhenhai , Li Chuzhao , Hu Hongyu , Zhao Hui , Chen Chaoyang , Yu Huili
Published: August 2015

Abstract

Frontal vehicle collisions can cause injury to a driver’s cervical muscles resulting from intense changes in muscle strain and muscle load. This study investigated the influence of collision forces in a sled test environment using a modified Hybrid III 50th percentile dummy equipped with simulated spring-type muscles. Cervical muscle responses including strain and load of the sternocleidomastoid (SCM), splenius capitis (SPL), and trapezius (TRP) were analyzed, and muscle injury was assessed. The SCM, SPL, and TRP suffered average peak muscle strains of 21%, 40%, and 23%, respectively, exceeding the injury threshold. The average peak muscle loads of the SCM, SPL and TRP were 11 N, 25 N, and 25 N, respectively, lower than the ultimate failure load. The SPL endured the largest injury, while the injuries to the SCM and TRP were relatively small. This is a preliminary study to assess the cervical muscle of driver during a frontal vehicle collision. This study provides a foundation for investigating the muscle response and injury in sled test environments, which can lead to the improvement of occupant protections.
Design of a quasi-passive 3 DOFs ankle-foot wearable rehabilitation orthosis
Authors: Zhang Chao , Zhu Yanhe , Fan Jizhuang , Zhao Jie , Yu Hongying
Published: August 2015

Abstract

Muscular rigidity and atrophy caused by long-term underactivity usually lead to foot drop, strephenopodia, foot extorsion or some other complications for the lower limb movement disorders or lower limb surgery sufferers. The ankle-foot orthosis can help patients conduct the right ankle motion mode training, inhibit spasm and prevent ankle complications. In this paper, a quasi-passive 3 DOFs ankle-foot wearable orthosis was designed on the basis of kinematics and dynamics analysis of the ankle joint. Ankle joint trajectory and dynamic characteristics similar to those of natural gait can be obtained by the combination of passive energy storage and additional power complement. In terms of function, the orthosis has shock absorption and low energy consumption. Given its excellent characteristics of comfortableness, lightweight, and anthropomorphic construction, the orthosis can be used in medical institutions for rehabilitation training or as a daily-walking auxiliary equipment for surgery sufferers.
Falls study: Proprioception, postural stability, and slips
Authors: Sohn Jeehoon , Kim Sukwon
Published: August 2015

Abstract

The present study evaluated effects of exercise training on the proprioception sensitivity, postural stability, and the likelihood of slip-induced falls. Eighteen older adults (6 in balance, 6 in weight, and 6 in control groups) participated in this study. Three groups met three times per week over the course of eight weeks. Ankle and knee proprioception sensitivities and postural stability were measured. Slip-induced events were introduced for all participants before and after training. The results indicated that, overall, strength and postural stability were improved only in the training group, although proprioception sensitivity was improved in all groups. Training for older adults resulted in decreased likelihood of slip-induced falls. The study suggested that proprioception can be improved by simply being active, however, the results suggested that training would aid older adults in reducing the likelihood of slip-induced falls.
Accelerating sino-atrium computer simulations with graphic processing units
Authors: Zhang Hong , Xiao Zheng , Lin Shien-fong
Published: August 2015

Abstract

Sino-atrial node cells (SANCs) play a significant role in rhythmic firing. To investigate their role in arrhythmia and interactions with the atrium, computer simulations based on cellular dynamic mathematical models are generally used. However, the large-scale computation usually makes research difficult, given the limited computational power of Central Processing Units (CPUs). In this paper, an accelerating approach with Graphic Processing Units (GPUs) is proposed in a simulation consisting of the SAN tissue and the adjoining atrium. By using the operator splitting method, the computational task was made parallel. Three parallelization strategies were then put forward. The strategy with the shortest running time was further optimized by considering block size, data transfer and partition. The results showed that for a simulation with 500 SANCs and 30 atrial cells, the execution time taken by the non-optimized program decreased 62% with respect to a serial program running on CPU. The execution time decreased by 80% after the program was optimized. The larger the tissue was, the more significant the acceleration became. The results demonstrated the effectiveness of the proposed GPU-accelerating methods and their promising applications in more complicated biological simulations.
Design of a biped robot actuated by pneumatic artificial muscles
Authors: Liu Yixiang , Zang Xizhe , Liu Xinyu , Wang Lin
Published: August 2015

Abstract

High compliant legs are essential for the efficient versatile locomotion and shock absorbency of humans. This study proposes a biped robot actuated by pneumatic artificial muscles to mimic human locomotion. On the basis of the musculoskeletal architecture of human lower limbs, each leg of the biped robot is modeled as a system of three segments, namely, hip joint, knee joint, and ankle joint, and eleven muscles, including both monoarticular and biarticular muscles. Each rotational joint is driven by a pair of antagonistic muscles, enabling joint compliance to be tuned by operating the pressure inside the muscles. Biarticular muscles play an important role in transferring power between joints. Walking simulations verify that biarticular muscles contribute to joint compliance and can absorb impact energy when the robot makes an impact upon ground contact.
Temporal integration reflected by frequency following response in auditory brainstem
Authors: Xu Qin , Ye Datian
Published: August 2015

Abstract

Auditory temporal integration (ATI) has been widely described in psychoacoustic studies, especially for loudness perception. Loudness increases with increasing sound duration for durations up to a time constant about 100 ∼ 200 ms, and then loudness becomes saturated with more duration increase. However, the electrophysiological mechanism underlying the ATI phenomenon has not been well understood. To investigate ATI at the brainstem level of auditory system and its relationship to cortical and behavioral ATI, frequency follow response (FFR) was acquired in our study. Simultaneously, ATI in auditory cortex was evaluated by cortical response P1. Behavioral loudness and electrophysiological measures were estimated from normal-hearing young adults for vowel /a/ whose durations varied from 50 ms to 175 ms. Significant effects of stimulus duration were found both on FFR and P1 amplitudes. Linear regression analysis revealed that as stimulus duration increased, brainstem FFR amplitude was significantly associated with cortical P1 amplitude and behavioral loudness, which confirmed the existence of temporal integration in auditory brainstem. Moreover, behavioral loudness ATI was better predicted using brainstem and cortical measures together than merely using each one separately, indicating an interplay and coordination for ATI across the three levels along auditory pathway.
A new method to accurately assess post-laser-surgery refractive changes with the intrinsic corneal power changes
Authors: Liu Yongji , Wang Zhaoqi , Wang Yan
Published: August 2015

Abstract

To evaluate the ability of assessing the refractive change induced by myopic laser surgery using the intrinsic data, obtained from a reference intrinsic to the cornea. Twenty-nine eyes with laser in situ keratomileusis for myopia were included in the study. Statistical analyses were performed to determine the relationship between refractive changes and two kinds of corneal power: KIP_value (obtained by keratometric index of 1.3375 and radius of curvature) and RIP_value (obtained by real corneal refraction index of 1.376 and radius of curvature). The comparisons were made between results given by intrinsic data and Pentacam HR. Preoperatively, the intrinsic radii of curvature are significantly less (p≪0.001) than those from Pentacam HR, while the intrinsic radii of curvature are significantly larger (p≪0.001) after surgery. The corneal power changes given by Pentacam HR always underestimate the refractive changes. However, the intrinsic data generally reduce the discrepancies between the corneal power and the refractive changes. The intrinsic KIP_value correlated best with the refractive changes at the corneal plane (p≪0.001) with a prediction error as low as 1.51%. The use of intrinsic data of the cornea can possibly provide an accurate estimation of surgically induced refractive changes.
The involvement of neuronal nitric oxide synthase in the anti-epileptic action of curcumin on pentylenetetrazol-kindled rats
Authors: Zhu Wenting , Su Jing , Liu Jing , Jiang Changbin
Published: August 2015

Abstract

In this study, it was investigated whether a NO signaling pathway is involved in the anti-epileptic effect of curcumin on pentylenetetrazol (PTZ)-kindled rats. PTZ-kindled rats received different doses of curcumin that were administered intraperitoneally for 24 days. Either a non-selective inhibitor of nitric oxide synthase (NOS) (N-nitro-L-arginine methyl ester (L-NAME)), a selective inhibitor of neuronal NOS (7-Nitroindazole (7-NI)), a selective inhibitor of inducible NOS (aminoguanidine (AG)), or a NO precursor (L-arginine (L-ARG)) was administered chronically to evaluate the role of NO in curcumin’s anti-seizure effect. A chronic administration of curcumin (200 mg/kg) was most effective for decreasing the mean frequency of epileptiform discharge. Furthermore, a pretreatment with L-NAME or 7-NI augmented the anti-epileptic effect of curcumin. In contrast, AG failed to significantly alter the anti-epileptic effect of curcumin. A pretreatment with L-ARG temporally reversed the anti-epileptic effect of curcumin in the early stage, but in the late stage, it potentiated curcumin’s anti-epileptic effect. These findings suggest that the L-arginine–nitric oxide pathway may be involved in the anti-epileptic properties of curcumin, and that the role of nNOS (and not iNOS) is prominent in this neuroprotective feature.
Quantitative evaluation of contrast-induced-nephropathy in vascular post-angiography patients: Feasibility study of a semi-empirical model
Authors: Pan Lung Fa , Davaa Otgonbaatar , Chen Chien Yi , Pan Lung Kwang
Published: August 2015

Abstract

In this study, the contrast-induced-nephropathy (CIN) of vascular patients who had undergone angiography was quantitatively evaluated using a semi-empirical model. The model compiled six essential serum readings and biological data from 70 patients in order to develop a 1st-order nonlinear equation with 16 defined terms. The expectation value of the model was used to predict the serum creatinine reading of patients that had been determined to be at high risk of CIN after contrast media (CM) administration. The other five variables included body surface area (BSA), administrated CM, serum creatinine level before CM administration, blood urea nitrogen (BUN), and systolic blood pressure level. A loss function was used to define the difference between the observed and predicted serum creatinine readings after CM administration. The dominant variables were proven to be systolic blood pressure, serum creatinine level before CM administration, and BSA. The cross interaction between the serum creatinine level before CM administration and systolic blood pressure was the decisive term of the model’s performance, indicating that both should be specially considered in order to prevent CIN. The BSA, which was usually ignored by medical staff, was also proven to be a significant variable, whereas the BUN reading and amount of injected contrast media were negligible in the semi-empirical model.
Mental workload prediction based on attentional resource allocation and information processing
Authors: Xiao Xu , Wanyan Xiaoru , Zhuang Damin
Published: August 2015

Abstract

Mental workload is an important component in complex human-machine systems. The limited applicability of empirical workload measures produces the need for workload modeling and prediction methods. In the present study, a mental workload prediction model is built on the basis of attentional resource allocation and information processing to ensure pilots’ accuracy and speed in understanding large amounts of flight information on the cockpit display interface. Validation with an empirical study of an abnormal attitude recovery task showed that this model’s prediction of mental workload highly correlated with experimental results. This mental workload prediction model provides a new tool for optimizing human factors interface design and reducing human errors.
Fuzzy linguistic prediction model for sinoatrial node field potential analysis in acute hyperglycemia environment
Authors: Feng Yu , Cao Hui , Wang Yanxia , Zhang Yanbin
Published: August 2015

Abstract

The objective of this study is to build a fuzzy linguistic prediction model (FLPM) for analyzing the actuation duration of acute hyperglycemia to sinoatrial node field potential. The field potential was recorded using microelectrode arrays (MEA). The experimental data were analyzed using partial least squares (PLS), support vector machine (SVM), back propagation neural network (BPNN) and the proposed method. The experimental results showed that the fuzzy linguistic prediction model could be adopted for predicting the actuation duration of high glucose to the sinoatrial node field potential. Compared with the other aforementioned models, the proposed model had higher prediction accuracy.
Novel DiR and SPIO nanoparticles embedded PEG-PLGA nanobubbles as a multimodalimaging contrast agent
Authors: Luo Binhua , Zhang Huajie , Liu Xuhan , Rao Rong , Wu Yun , Liu Wei
Published: August 2015

Abstract

Fluorescence dye DiR and superparamagnetic iron oxide nanoparticles (SPIONs) embedded in PEG-PLGA nanobubbles (DiR-SPIO-NBs) were produced using double emulsion method on a membrane of Shirasu porous glass (SPG). The nanobubbles encapsulated with DiR and SPIONs had a liquid core (perfluoropentane) and a PEG-PLGA shell. DiR-SPIO-NBs showed biocompatibility based on MTT cytotoxicity and hemolysis studies. The PFP encapsulated in the nanobubbles experienced phase transition under ultrasonic irradation. Nanobubbles dispersed well in saline over 3 months, and the relaxivity was 127.9 mM−1s−1, suggesting that it could be used as a contrast agent in MRI. The MR and fluorescence images in vivo demonstrated that the signal intensity in the spleen and liver was significantly enhanced with the treatment of nanobubbles. In addition, results of ultrasound images suggested that the nanobubbles had persistent contrast ability. In conclusion, nanobubbles could be utilized as an US/MRI/fluorescence contrast agent.
Analog front-end measuring biopotential signal with effective offset rejection loop
Authors: Lim Seunghyun , Kim Hyunho , Song Haryong , Cho Dong-il “Dan” , Ko Hyoungho
Published: August 2015

Abstract

This paper presents an analog front-end (AFE) IC design for recording biopotential signals. The AFE employs a capacitively coupled instrumentation amplifier to achieve a low-noise and high-common mode rejection ratio (CMRR) system. A ripple reduction loop is proposed to reduce the ripple generated by the up-modulating chopper. The low frequency noise is attenuated by an input AC coupling capacitor, and is attenuated again by a DC servo loop. The proposed AFE features a differential gain of 71 dB, and a CMRR of 89 dB, at 50 Hz. Furthermore, the proposed AFE can robustly acquire biopotential signals even in the presence of an input offset and ripples.
A radiation emission shielding method for high intensity focus ultrasound probes
Authors: Wu Hao , Shen Guofeng , Chen Yazhu
Published: August 2015

Abstract

Electromagnetic compatibility (EMC) is a key issue in the design and development of safe and effective medical instruments. The treatment probes of high intensity focused ultrasound (HIFU) systems not only receive and transmit electromagnetic waves, but also radiate ultrasound waves, resulting in electromagnetic coupling. In this paper, an electromagnetic shielding method involving the enclosure of the probe in a copper wire mesh was introduced. First, sound pressure distribution simulations and measurements were performed using a hydrophone in order to evaluate the effects of the wire mesh on the acoustic performance of the HIFU system. The results indicated that the wire mesh did not disturb the normalized sound pressure field. In addition, the attenuation of the maximum pressure in the focal plane was equal to 6.2%. Then, the electronic emission level was tested in a chamber. After the implementation of the wire mesh, the 10-100 MHz frequency band radiation was suppressed, and the HIFU system satisfied the national EMC standards.
Brain white matter fiber estimation and tractography using Q-ball imaging and Bayesian MODEL
Authors: Lu Meng
Published: August 2015

Abstract

Diffusion tensor imaging allows for the non-invasive in vivo mapping of the brain tractography. However, fiber bundles have complex structures such as fiber crossings, fiber branchings and fibers with large curvatures that tensor imaging (DTI) cannot accurately handle. This study presents a novel brain white matter tractography method using Q-ball imaging as the data source instead of DTI, because QBI can provide accurate information about multiple fiber crossings and branchings in a single voxel using an orientation distribution function (ODF). The presented method also uses graph theory to construct the Bayesian model-based graph, so that the fiber tracking between two voxels can be represented as the shortest path in a graph. Our experiment showed that our new method can accurately handle brain white matter fiber crossings and branchings, and reconstruct brain tractograhpy both in phantom data and real brain data.
Iterative reconstruction with segmentation penalty for PET
Authors: Teng Yueyang , Zhang Yaonan , Kang Yan
Published: August 2015

Abstract

Segmentation technique is widely accepted to reduce noise propagation from transmission scanning for positron emission tomography. The conventional routine is to sequentially perform reconstruction and segmentation. A smoothness penalty is also usually used to reduce noise, which can be imposed to both the ML and WLS estimators. In this paper we replace the smoothness penalty by a segmentation penalty that biases the object toward piecewise-homogeneous reconstruction. Two updating algorithms are developed to solve the penalized ML and WLS estimates, which monotonically decrease the cost functions. Experimental results on simulated phantom and real clinical data were both given to demonstrate the effectiveness and efficiency of the algorithms which were proposed.