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Magnetic nanoparticle CoFe2O4-based hyperthermia is a promising non-invasive approach for cancer therapy. However, CoFe2O4 nanoparticles (NPs) have a low heat transfer efficiency, which limits their practical clinical applications. Hence, it is necessary to investigate the higher-performance magnetic NPs-based hybrid nanostructures to enhance their magnetic hyperthermia efficiency. This work presents a facile in situ approach for synthesizing cobalt ferrite (CoFe2O4) silver (Ag) hybrid NPs as optical-magnetic hyperthermia heat mediators. The prepared cobalt ferrite silver hybrid NPs exhibit a higher heat generation than that of individual Ag or CoFe2O4 NPs under simultaneous exposure to an alternating current magnetic field and laser source. The obtained results confirm that the hybridization of CoFe2O4 and Ag NPs could significantly enhance the hyperthermia efficiency of the prepared NPs. Therefore, the CoFe2O4-Ag hybrid NPs are considered as potential candidates for a high-performance hyperthermia mediator based on a simple and effective synthesis approach.

Ocean radiation monitoring and warning systems are essential in monitoring radioactive species' contamination levels in an oceanic environment and predicting the radioactive materials propagation caused by nuclear incidents in a marine area. Since the Fukushima nuclear disaster, different types of mobile radiation monitoring devices have been investigated based on modern technologies in electronic – communication. Those types of equipment can directly measure the radioactive contamination in the ocean instead of the traditional laboratory method. This study presents a complete process of researching, designing, manufacturing, and integrating a mobile radiation monitoring system (MRMS) in the ocean. The integrated radiation sensor can both measure radiation dose rate and identify radioactive isotopes on a floating device. The measured data from the sensor is processed and displayed on the electronic block by developed software, or it can be transmitted directly to the mainland by one of three different communication devices. This prototype system is the first product in Vietnam in the development of the MRMS, which is highly promising in terms of performance, low cost, and maintenance.

In conventional Finite Element – Lagrangian methods, the dynamics model of a flexible robot is usually formulated based on a critical assumption that the kinetic energy of an element is approximately calculated with an integral of mass point energy. Since the energy integral is implicit, the formulation of the dynamics model is also very complex and implicit. Hence, this paper develops a new mathematical approach for the dynamic modelling of a general flexible/rigid robot. The proposed method is more comprehensive and efficient in comparison with the previous ones because it no longer requires the calculation of the symbolic integrals and the implicit expressions of the elemental and global mass matrices. Besides, the proposed approach is applicable for both the flexible robots and the hybrid flexible/rigid robots. To validate the proposed method, numerical simulations and experimental results are presented.

Developing standard communication in an educational environment is imperative. Currently, by equipping behavioral skills, especially communication skills, to confidently communicate and integrate into a multicultural environment without losing national identity, students can become not only holistically developed global citizens in virtue, mind, and strength but also knowledgeable, skillful, and professionally responsible as set out in the educational goals by the University. This topic investigates the status quo of communication behaviors and some factors that affect students' behaviors. This study was conducted using quantitative and qualitative methods, including a questionnaire survey and interviews. The results show that the communication behaviors of students of the Foreign Languages Department at the University are affected by various factors such as learning environment, family circumstances, educational background, etc. Based on the results of surveys and interviews provided by students and lecturers of a university in the Mekong Delta, the topic researches and proposes a set of communication rules for students at the University. Article visualizations

Designing proper frontend electronics is critical in the development of highly sophisticated electrode systems. Multielectrode arrays for measuring electrical signals or impedance require multichannel readout systems. Even more challenging is the differential or ratiometric configuration with simultaneous assessment of measurement and reference channels. In this work, an eight-channel frontend was developed for contacting a 2×8 electrode array (8 measurement and 8 reference electrodes) with a large common electrode to the impedance gain-phase analyzer Solartron 1260 (S-1260). Using the three independent and truly parallel monitor channels of the S-1260, impedance of trapped cells and reference material was measured at the same time, thereby considerably increasing the performance of the device. The frontend electronics buffers the generator output and applies a potentiostatic signal to the common electrode of the chip. The applied voltage is monitored using the current monitor of the S-1260 via voltage/current conversion. The frontend monitors the current through the electrodes and converts it to a voltage fed into the voltage monitors of the S-1260. For assessment of the 8 electrode pairs featured by the chip, a relay-based multiplexer was implemented. Extensive characterization and calibration of the frontend were carried out in a frequency range between 100 Hz and 1 MHz. Investigating the influence of the multiplexer and the frontend electronics, direct measurement with and without frontend was compared. Although differences were evident, they have been negligible below one per cent. The significance of measurement using the complex S-1260-frontend-electrode was tested using Kohlrausch's law. The impedance of an electrolytic dilution series was measured and compared to the theoretical values. The coincidence of measured values and theoretical prediction serves as an indicator for electrode sensitivity to cell behavior. Monitoring of cell behavior on the microelectrode surface will be shown as an example.

Compressive sampling (CS) has been commonly employed in the field of magnetic resonance imaging (MRI) to accurately reconstruct sparse and compressive signals. In a MR image, a large amount of encoded information focuses on the origin of the k-space. For the 2D Cartesian K-space MRI, under-sampling the frequency-encoding (kx) dimension does not affect to the acquisition time, thus, only the phase-encoding (ky) dimension can be exploited. In the traditional random under-sampling approach, it acquired Gaussian random measurements along the phaseencoding (ky) in the k-space. In this paper, we proposed a hybrid under-sampling approach; the number of measurements in (ky) is divided into two portions: 70% of the measurements are for random under-sampling and 30% are for definite under-sampling near the origin of the k-space. The numerical simulation consequences pointed out that, in the lower region of the under-sampling ratio r, both the average error and the universal image quality index of the appointed scheme are drastically improved up to 55 and 77% respectively as compared to the traditional scheme. For the first time, instead of using highly computational complexity of many advanced reconstruction techniques, a simple and efficient CS method based simulation is proposed for MRI reconstruction improvement. These findings are very useful for designing new MRI data acquisition approaches for reducing the imaging time of current MRI systems.

The aim of this work is to fabricate a sensitive and novel enzymeless electrochemical sensor for the simultaneous determination of parathion and paraoxon using the Nd-UiO-66@MWCNT nanocomposite. For this purpose, Neodymium (Nd) was introduced into a Universitetet i Oslo (UiO-66) structure to construct Nd-UiO-66 and then, adding multi-walled carbon nanotubes to the Nd-UiO-66 to increase the electrocatalytic activity and surface area of the obtained composite. The Nd-UiO-66@MWCNT has numerous advantages like excellent conductivity, tunable texture, and large surface area and can be used as a distinctive structure for the construction of modified glassy carbon electrode (GCE) to enhance the charge-transfer and the efficiency of electrochemical sensors. This modified electrode showed sensitive and selective determination of paraoxon and parathion over the linear ranges of 0.7-100 and 1-120 nM, with detection limits of 0.04 and 0.07 nM, respectively. The proposed Nd-UiO-66@MWCNT/GCE sensor in this study can be applied in environmental and toxicological laboratories and field tests to detect parathion and paraoxon levels.

Nanomaterials of cobalt ferrite (CoFe2O4) doped with zinc have been synthesized by co-precipitation using KOH solution of 10-4 M as a precipitant. The effect of zinc contents and calcination temperature on the structure and magnetic properties of Co1-xZnxFe2O4 were studied. The parameters of the crystalline cubic lattice (a ~ 8.4 Å) and the crystalline size (d = 20–30 nm) increased with increasing the calcination temperature and zinc content in the samples. However, the remanent magnetization, saturation magnetization, coercive force and M at the maximum field decreased with increasing the zinc content. The nanomaterials of cobalt ferrite doped with zinc have Hc values in the range of 8.67–179.63 Oe, Mr values in the range of 1.33–16.90 emu/g, which are quite smaller than those of original CoFe2O4 material (Hc=497.89 Oe, Mr=36.29 emu/g); moreover, the nanomaterials prepared have Ms values in the range of 56.00 – 99.97 emu/g, which are similar to those of original CoFe2O4 material (Ms= 88.67 emu/g) and are quite higher than those of original ZnFe2O4 material (Ms ~ 1.2 emu/g).

Microsphere biolasers employing biological materials as their cavity matrix have attracted tremendous research attention due to their potential for bio-integration, cell-tracking and biosensing. Several techniques have been applied for fabricating microsphere biolasers such as emulsion and vacuum freeze-drying but the current technology generally can not control the output size of the laser and therefore hinder them from many applications. In this work, we demonstrate that a low-cost microfluidic device can be very effective in fabricating nearly monodisperse dye-doped protein microspheres with up to 70% of them having the same size. Under optical pumping, these microspheres emit lasing emission with a lasing threshold of ∼1 µJ and a quality factor of ∼2.5 × 103. The lasing mechanism is ascribed to whispering gallery mode. Furthermore, the obtained microlasers can be employed for temperature sensing based on the wavelength shift of lasing mode with increasing temperature. The sensor sensitivity in the measured range of 25 °C–50 °C is about 0.47 nm/°C. More interestingly, microlasers of the same size exhibit a very similar sensing performance which confirm their high reproducibility and reliability. Owing to the biocompatibility and small size, these miniature laser-based sensors can be implantable in skins and tissues for biological studies and medical diagnostic.

Microsphere biolasers have attracted a great deal of interest due to their potential for biosensing and cell tracking. Here we demonstrate a novel, to the best of our knowledge, microfluidic-based fabrication of nearly monodisperse dye-doped protein microsphere biolasers with a tunable size from 150 to 50 µm. In particular, for an 85 µm-bead, about 70% of the fabricated microspheres have the same size of 85 µm. Under optical pumping, the fabricated microspheres emit whispering gallery mode lasing emission with a lasing threshold of 7 µ J m m − 2 and quality ( Q ) factor up to 3000. Interestingly, microspheres with the same size exhibit a similar lasing threshold and spectrum. The result indicates a high reproducibility of microsphere biolasers by the microfluidic-based fabrication technique. This Letter provides an effective method for mass production of high- Q factor microsphere biolasers which is a significant step toward real biosensing and medical applications.

Alport Syndrome (AS) is a genetic disorder characterized by impaired kidney function. The development of a noninvasive tool for early diagnosis and monitoring of renal function during disease progression is of clinical importance. Hyperpolarized 13C MRI is an emerging technique that enables non-invasive, real-time measurement of in vivo metabolism. This study aimed to investigate the feasibility of using this technique for assessing changes in renal metabolism in the mouse model of AS. Mice with AS demonstrated a significant reduction in the level of lactate from 4- to 7-week-old, while the levels of lactate were unchanged in the control mice over time. This reduction in lactate production in the AS group accompanied a significant increase of PEPCK expression levels, indicating that the disease progression in AS triggered the gluconeogenic pathway and might have resulted in a decreased lactate pool size and a subsequent reduction in pyruvate-to-lactate conversion. Additional metabolic imaging parameters, including the level of lactate and pyruvate, were found to be different between the AS and control groups. These preliminary results suggest that hyperpolarized 13C MRI might provide a potential noninvasive tool for the characterization of disease progression in AS.

This paper presents the results of the comparison of the use efficiency between two numerical algorithms which are the Adjust of Generalized Vector (AGV) and the Closed-Loop Inverse kinematics (CLIK) method when solving the inverse kinematics problem (IK) for the redundant serial-link robots. AGV method is developed based on the Taylor expansion method but adjusted to improve the accuracy of the IK solution. CLIK is a numerical method that is built as a closed-loop kinematics control system with the position error of the end-effector point in the workspace. The industrial SCARA robots with 4 degrees of freedom (DOF) including rotational and translational joints and PA10-7C industrial robots with 7-DOF are used to illustrate the effectiveness of the algorithms. The comparison results are expressed through the obtained joint variables values, the position error of the end-effector point in the workspace, and the deviation values of joint variables between the two methods. The results of this study allow evaluating the effectiveness of these methods for solving the IK and serve as the basis for choosing a suitable method for each specific robot configuration. However, this article has not considered the effectiveness of the methods mentioned above for other types of robots.

In practice, the inverse kinematic modelling and analysis of a five-axis CNC center is of importance when transferring and postprocessing a cutter location (CL) data file for machining part surfaces of complex geometry. Decades ago, though there has been a number of investigations focusing on the kinematic modelling and postprocessor development for five-axis CNC centers, a little attention has been paid to the generalization of the inverse kinematic modelling for the rotational axes of five-axis CNC centers. In this paper, a new and general analytical approach for deriving effectively the inverse kinematic equation of two rotational axes of any five-axis CNC center is proposed. It has shown that the proposed technique is very useful for the postprocessor development of any five-axis CNC center.

In most of the previous investigations, the kinematics model of five-axis computer-numerical control (CNC) centers was formulated just at the position level, and the differential kinematic relationships (velocity, acceleration and jerk of the five joints of a five-axis center) that are necessary for several purposes, especially for investigating the relationship between the limits of a machine’s drives and the feed rate maximization (the productivity maximization), have been overlooked. Therefore, this paper addresses the differential kinematic modelling and analysis for the five-axis CNC centers. In particular, the differential kinematic equations are formulated in a parametric domain so that they are useful for investigating the kinematic behaviors of the five-axis centers in real time.

Magnetic nanoparticles (MNPs) have garnered increasing attention for use in the improvement and production of magnetic biosensing, magnetic isolation and purification, drug delivery, quantitative investigation, and magnetic imaging for numerous usages. The latest improvements in the exploitation of nanomagnetic particles for amending various levels of analytical procedures are reviewed. According to the results obtained in the field of analytical chemistry research, the exploitation of magnetic fields affords useful and beneficial techniques for manipulating and examining particles at the molecular level. Among these different applications of magnetic nanomaterials in analytical chemistry, this chapter considers the usages of MNPs in colorimetric sensors. Colorimetric techniques have acquired noteworthy consideration due to such benefits as selectivity; easy preparation; and fast, sensitive, and cost-effective recognition; and it does not require advanced and sophisticated devices.