Electrical power free, low dead volume, pressure-driven pumping for microfluidic applications

This paper presents a simple-to-construct, low dead volume pump capable of generating a wide range of positive and negative pressures for microfluidic applications. The pump generates pressure or vacuum by changing the volume of air confined inside a syringe and is able to generate pressures between -95 and +300 kPa with a resolution as high as 1 Pa. Different from syringe pumps and electrokinetic pumping, which are capable of controlling flow rates only, our pump can be used to generate constant flow rates or constant pressures, which are required for certain applications such as the aspiration of biological cells for biophysical characterization. Compared to syringe pumps, the new pump has almost zero dead volume and does not exhibit pulsatile flows. Additionally, the system does not require electrical power and is cost effective (～$100). To demonstrate the capabilities of the pump, we used it to aspirate osteoblasts (MC3T3-E1 cells) and to determine Young's modulus of the cells, to generate a concentration gradient, and to produce variable-sized droplets in microchannels using hydrodynamic focusing.     

A new approach for constrained chaos synchronization with application to secure data communication

In this paper, a new technique is introduced for chaos secure data communication. In this approach, in addition to the usually used techniques for data encryption, the concept of carrier encryption is introduced to increase the security level of the secure communication scheme. To fulfill this objective, at the transmitting end, two chaotic oscillators are coupled, and a set of inequality time dependent constraints with time dependent bounds is imposed on the generated chaotic signals. Moreover, to increase system complexity and its security level, the imposed set of constraints and their bounds are allowed to be changeable from one time period to another during the transmission process. As a result, the patterns of the generated chaotic signals are completely changed and the chaotic oscillator is completely encrypted. At the receiving end, the newly developed Constrained Smoothed Regularized Least Square (CSRLS) observer is used to synchronize the received constrained chaotic signals and hence retrieve the transmitted data. Using such an approach, the quality of the received information, measured by the Bit Error Rate (BER), is highly improved due to the superior performance of the developed CSRLS observer. The stability of the observer is analyzed, and simulation results are presented to show the efficiency and effectiveness of the proposed secure communication scheme.     

A hybrid partial feedback linearization and deadbeat control scheme for a nonlinear gantry crane

This paper presents the design of a hybrid partial feedback linearization and deadbeat control scheme for a nonlinear gantry crane with friction to control its position and sway angle. The partial feedback linearization is used to linearize the nonlinear model and to stabilize its internal dynamics. In many crane applications, it's necessary to accelerate the system response. As a result, this will cause oscillation in the position as well as the sway angle. So, the deadbeat controller is added to get the desirable accelerated response without any oscillation or adverse effects on the internal dynamics stability. By using Lyapunov stability method, the proposed scheme is proved to be globally stable, with converging tracking errors to the desired performance. The simulation results are accomplished to evaluate the effectiveness of the proposed scheme and to demonstrate its reliability to control crane systems with comparative results.     

Urinary Urea,Uric Acid and Hippuric Acid as Potential Biomarkers in Multiple Sclerosis Patients

Urine is a proven source of metabolite biomarkers and has the potential to be a rapid, noninvasive, inexpensive, and efficient diagnostic tool for various human diseases. Despite these advantages, urine is an under-investigated source of biomarkers for multiple sclerosis (MS). The objective was to investigate the level of some urinary metabolites (urea, uric acid and hippuric acid) in patients with MS and correlate their levels to the severity of the disease, MS subtypes and MS treatment. The urine samples were collected from 73 MS patients-48 with RRMS and 25 with SPMS- and age matched 75 healthy controls. The values of urinary urea, uric acid and hippuric acid in MS patients were significantly decreased, and these metabolites in SPMS pattern showed significantly decrease than RRMS pattern. Also showed significant inverse correlation with expanded disability status scale and number of relapses. Accordingly, they may act as a potential urinary biomarkers for MS, and correlate to disease progression.     

The effect of 10 days of intermittent fasting on Wingate anaerobic power and prolonged high-intensity time-to-exhaustion cycling performance

Many physically active individuals have undertaken intermittent fasting to reduce their daily caloric intake. However, abstaining from meals for a specific length of time may lead to the acute disturbance of highly carbohydrate-dependent exercise performance. The purpose of this study was to observe the effect of 10 days of intermittent fasting on high-intensity type exercises, Wingate anaerobic (WT) and prolonged high-intensity time-to-exhaustion (HIT) cycling test. Twenty participants were randomised into an intermittent fasting (FAS) and a control group (CON). One day after baseline data collection on Day-0 where participants consumed their recommended daily caloric intake (FAS?=?2500?±?143?kcal?day^?1; CON?=?2492?±?20?kcal?day^?1) served over a course of five meals, the FAS group consumed only four meals where 40% was restricted by the omission of lunch (FAS?=?1500?±?55?kcal?day^?1). This diet was then continued for 10 days. Data on exercise performance and other dependent variables were collected on Day-2, -4, -6, -8 and -10. A reduction in WT power in the FAS group was observed on Day-2 (821.74?±?66.07?W) compared to Day-0 (847.63?±?95.94?W) with a moderate effect size (p?p?p?相似文献   

Correction to: Examining Agency in Children’s Nonfiction Picture Books

Children's Literature in Education - In the original publication of the article unfortunately contained a mistake in the name of co-author Vera Sotirvoska.The correct name should be Vera...     

Dynamic three-dimensional virtual environment to improve learning of anatomical structures

Increasing number of medical students and limited availability of cadavers have led to a reduction in anatomy teaching through human cadaveric dissection. These changes triggered the emergence of innovative teaching and learning strategies in order to maximize students learning of anatomy. An alternative approach to traditional dissection was presented in an effort to improve content delivery and student satisfaction. The objective of this study is to acquire three-dimensional (3D) anatomical data using structured-light surface scanning to create a dynamic four-dimensional (4D) dissection tool of four regions: neck, male inguinal and femoral areas, female perineum, and brachial plexus. At each dissection step, identified anatomical structures were scanned using a 3D surface scanner (Artec Spider™). Resulting 3D color meshes were overlaid to create a 4D (3D+time) environment. An educational interface was created for neck dissection. Its implementation in the visualization platform allowed 4D virtual dissection by navigating from surface to deep layers and vice versa. A group of 28 second-year medical students and 17 first-year surgery residents completed a satisfaction survey. A majority of medical students (96.4%) and 100% of surgery residents said that they would recommend this tool to their colleagues. According to surgery residents, the main elements of this virtual tool were the realistic high-quality of 3D acquisitions and possibility to focus on each anatomical structure. As for medical students, major elements were the interactivity and entertainment aspect, precision, and accuracy of anatomical structures. This approach proves that innovative solutions to anatomy education can be found to help to maintain critical content and student satisfaction in anatomy curriculum.     

Promoting more future-ready anatomy education after the Covid-19 pandemic: A scoping review

The coronavirus disease 2019 (Covid-19) pandemic caused an abrupt transition from face-to-face to online anatomy teaching, learning, and assessment. Although online education has ensured the continuity of anatomy education during the pandemic, its implementation has been challenging, and its effectiveness has been questioned. Therefore, literature pertinent to online anatomy education during the pandemic is crucial to explain Covid-19's disruptions to this field. Accordingly, this scoping review explored changes, disruptions, and gaps in anatomy teaching and assessment during Covid-19 using an enhanced version of Arksey and O′Malley's six-stage protocol. Five online databases were searched for articles that described changes and disruptions in anatomy education. Three independent researchers were involved in titles, abstracts, and full texts screening, while another four researchers were independently involved in data extraction, charting, and synthesis. This review revealed six themes: immediate strategic plans and actions, teaching and learning changes, online assessment practice, students' and educators' receptivity and adaptability, online learning and assessment effects, and future directions. It also revealed four gaps: non-future-ready curricula, learning obstacles, administrative and teaching challenges, and online education ethical issues. The results were reported in tabular and narrative forms, following the PRISMA Extension for Scoping Reviews (PRISMA-ScR guidelines). Understanding the evolution and gaps in anatomy education during the Covid-19 pandemic will help anatomists design future-ready, adaptable curricula.