Feasibility Experiment Research Articles

A novel solution for freezing small numbers of spermatozoa using a sperm vitrification device.

Does a novel sperm vitrification device (SpermVD) provide an efficient method for freezing a small number of human spermatozoa from men suffering from non-obstructive azoospermia? The novel SpermVD is an efficient and simple carrier method for freezing a small number of spermatozoa in low-volume droplets, reducing post-thaw search time from hours to minutes, allowing a 96% recovery rate and leading to successful use of sperm for fertilization. Previous methods for cryopreservation of small numbers of human spermatozoa (e.g. mini-straws, ICSI pipette, alginate beads, cryoloop) have been proposed as a solution for cases of severe male infertility. Many drawbacks have prevented their widespread use, including cumbersome preparation and sperm retrieval procedures, and the fact that the thawed spermatozoa are not immediately available for micromanipulation and required additional treatment which posed excess risk of harm. We conducted a feasibility experiment of the novel SpermVD and a prospective cohort study of ICSI cycles in men suffering from non-obstructive azoospermia in two outpatient fertility IVF clinics, from 2015 through 2017. All patients underwent extended ejaculate search prior to the day of oocyte retrieval, and any single motile spermatozoa found was transferred to 0.8 μl droplets of 1:1 washing medium/cryoprotectant on the SpermVD, then plunged into liquid nitrogen for cryopreservation. In patients with non-obstructive azoospermia who underwent surgical TESE, both the motile and immotile spermatozoa found underwent cryopreservation using the SpermVD. On the day of oocyte retrieval, the SpermVD was thawed, directly transfered to the ICSI plate and retrieved spermatozoa were used for the ICSI procedure. The prospective cohort included 44 cases. We used the SpermVD to vitrify 631 spermatozoa, of which 540 (86%) were motile. The average number of frozen spermatozoa per patient was 14.3 ± 9.3. After thawing, we retrieved 607 spermatozoa, producing a recovery rate of 96%. The average number of thawed spermatozoa was 13.8 ± 9.2. The recovery of 180 thawed motile sperm accounted for 33% of all frozen motile spermatozoa. The fertilization rate was 59%. Of 44 oocyte retrieval procedures, 24 (55%) clinical pregnancies were achieved. The delivery rate (not including three ongoing pregnancies) was 32% and the miscarriage rate was 29%. Although we presented the SpermVD on 44 cases, a larger cohort would provide more information. Moreover, we cryopreserved only motile sperm from the ejaculates and not immotile sperm, thus limiting the knowledge regarding the efficacy of the VD for immotile sperm from this source. The novel SpermVD is a simple efficient carrier, optimizing the protocol for freezing a small number of spermatozoa. It may allow for the routine use of frozen spermatozoa after TESE for men suffering from non-obstructive azoospermia and thus avoid repeated TESE surgeries. Furthermore, in cases of non-obstructive azoospermia, routine cryopreservation of the retrieved spermatozoa prior to the IVF cycle may avoid the risk of cycle cancelation and thus decrease the number of unnecessary oocyte retrieval procedures. There was no external funding. There are no competing interests. IRB no 00119-16-ASMC.

Feasibility experiment of physics-based global electron temperature profile control in KSTAR

KSTAR experiments have been conducted aiming at establishing a real-time control system that uses multiple actuators (NBI and ECH) to control the plasma profiles (Te and q profiles) and validating an applied physics-based plasma profile response model. Toward establishing the multiple plasma profile control system, the control experiment of the electron temperature profile has been performed in KSTAR as a first step. Although the plasma profile control system was in the commissioning phase, the electron temperature was feedback controlled successfully in real-time while the normalized radial profile of electron temperature remained nearly constant. In the circumstance, the implemented physics-based response model was successfully validated against control experiments with a step variation on the control target and an application of multiple actuators. The robustness of the controller is examined against an external disturbance in which a static version of the control matrix was used.

Feasibility study of carbon dioxide separation from gas mixture by vortex tube

The vortex tube uses energy separation technology to separate inlet gases into hotter and colder mixtures than the inlet state. In this research, a feasibility study is carried out on a vortex tube used to separate CO2 gas from air-CO2 gas mixture at atmospheric temperature. Prior to the feasibility experiment, transient response of vortex tube is investigated to determine the time needed to achieve steady state temperature of energy separation. The experimental parameters of gas separation are the pressures and concentrations of CO2 that is mixed with air. Results show that CO2 gas separation is proportional to operating pressure. The results also show that the cold mass fraction is a core parameter for gas separation. The percentage mass fraction of separated CO2 gas at cold exit is 7.4% at 3 barg and cold mass fraction of 0.6.

Assessment of a micro-UAV system for microwave tomography radar imaging

Micro-Unmanned Aerial Vehicles (UAVs) are flexible observation platforms suitable to cover inaccessible areas on demand. Accordingly, huge attention is deserved towards development of miniaturized sensing technologies compliant with UAV payload constrains and capable of providing high-resolution images of the region under test. As a contribution to this topic, the paper presents a prototype UAV system for radar imaging made by a commercial micro-UAV equipped with a miniaturized low power radar, whose imaging capabilities are enhanced by a properly designed data processing strategy. Such a strategy involves a processing step performed in time domain, which accounts for a procedure devoted to compensate flight altitude variation and a Singular Value Decomposition (SVD) based noise filtering approach. After, the focused images of the surveyed scenario are obtained by using a microwave tomographic approach, which integrates data about UAV position and faces the imaging as a linear inverse scattering problem. A feasibility experiment, carried out to test the operational mode of the assembled system, is presented. The obtained results corroborate that the integration of GPS and flight altitude information into the microwave tomography approach allows valuable radar imaging capabilities in terms of target localization accuracy.

Investigation onto nanometer millisecond delay charges

ABSTRACTIn this paper, through a new manufacturing process to obtain ultrafine milliseconds detonators, and then test its key performance parameters. An important factor influencing the delay precision detonator is determined by orthogonal experiments, thus optimizing formulations to expect to get a better precision detonator recipe. Through the analysis of the ultrafine particle size testing and the volume delay testing of the drug, the method of improving the accuracy of the delay detonator is put forward, and the technical feasibility experiment is used to verify that the ultrafine drug can improve the precision of the delay detonator in milliseconds.

Effect of correlating adjacent neurons for identifying communications: Feasibility experiment in a cultured neuronal network.

Neuronal networks have fluctuating characteristics, unlike the stable characteristics seen in computers. The underlying mechanisms that drive reliable communication among neuronal networks and their ability to perform intelligible tasks remain unknown. Recently, in an attempt to resolve this issue, we showed that stimulated neurons communicate via spikes that propagate temporally, in the form of spike trains. We named this phenomenon “spike wave propagation”. In these previous studies, using neural networks cultured from rat hippocampal neurons, we found that multiple neurons, e.g., 3 neurons, correlate to identify various spike wave propagations in a cultured neuronal network. Specifically, the number of classifiable neurons in the neuronal network increased through correlation of spike trains between current and adjacent neurons. Although we previously obtained similar findings through stimulation, here we report these observations on a physiological level. Considering that individual spike wave propagation corresponds to individual communication, a correlation between some adjacent neurons to improve the quality of communication classification in a neuronal network, similar to a diversity antenna, which is used to improve the quality of communication in artificial data communication systems, is suggested.

Feasibility Study for Unconstrained Respiration Monitoring Based on Multi-Way Approach Using an Acceleration and Force Sensing Module

The purpose of this paper was to validate the feasibility of a proposed sensing module for multiway respiratory monitoring. The proposed monitoring system was implemented using an ultralow-power microcontroller, that included a three-axis accelerometer, an analog/digital input port to connect to an external sensor, and a Bluetooth module for wireless communication. We developed an accelerometer-equipped wireless sensing module and a layered-architecture external strip-type force sensor interface for respiration monitoring. In the feasibility experiment, the accelerometer-equipped module was inserted in a pillow and strip-type force sensors were placed under each of the head, chest, and abdomen to investigate the performance of the respiration measurement in terms of the measurement position. Twelve subjects participated in the experiment, and signals from the accelerometer and the strip-type force sensor were simultaneously recorded during sleep. The results of the experiment showed that the deviation in length of the respiration cycle was estimated with errors under 250 ms in the acceleration signal and the signal from the strip force sensors.

Note: Development of a new Bridgman-type high pressure cell for accurate dielectric measurements.

We developed a new high pressure cell which allows us to perform accurate dielectric measurements above 3 GPa. The developed cell is based on Bridgman type opposed anvil cells with electrodes immersed into holes in the anvils in order to make the electrode area constant under compression. As a feasibility experiment, dielectric measurements for H2O were conducted up to 6.6 GPa and obtained dielectric constants are well consistent with previous studies.

Production of 92Y via the 92Zr(n,p) reaction using the C(d,n) accelerator neutron source

We have proposed a new method of producing medical radioisotope 92 Y as a candidate of alternatives of 111 In bioscan prior to 90 Y ibritumomab tiuxetan treatment. The 92 Y isotope is produced via the 92 Zr (n ,p ) reaction using accelerator neutrons generated by the interaction of deuteron beams with carbon. A feasibility experiment was performed at Cyclotron and Radioisotope Center, Tohoku University. A carbon thick target was irradiated by 20-MeV deuterons to produce accelerator neutrons. The thick target neutron yield (TTNY) was measured by using the multiple foils activation method. The foils were made of Al, Fe, Co, Ni, Zn, Zr, Nb, and Au. The production amount of 92 Y and induced impurities were estimated by simulation with the measured TTNY and the JENDL-4.0 nuclear data.

Feasibility Experiment of Respiratory Signal Measurement Based on Magnetic Induction

Feasibility Experiment of Respiratory Signal Measurement Based on Magnetic Induction

Protein characterization of intracellular target-sorted, formalin-fixed cell subpopulations.

Cellular heterogeneity is inherent in most human tissues, making the investigation of specific cell types challenging. Here, we describe a novel, fixation/intracellular target-based sorting and protein extraction method to provide accurate protein characterization for cell subpopulations. Validation and feasibility tests were conducted using homogeneous, neural cell lines and heterogeneous, rat brain cells, respectively. Intracellular proteins of interest were labeled with fluorescent antibodies for fluorescence-activated cell sorting. Reproducible protein extraction from fresh and fixed samples required lysis buffer with high concentrations of Tris-HCl and sodium dodecyl sulfate as well as exposure to high heat. No deterioration in protein amount or quality was observed for fixed, sorted samples. For the feasibility experiment, a primary rat subpopulation of neuronal cells was selected for based on high, intracellular β-III tubulin signal. These cells showed distinct protein expression differences from the unsorted population for specific (phosphorylated tau) and non-specific (total tau) protein targets. Our approach allows for determining more accurate protein profiles directly from cell types of interest and provides a platform technology in which any cell subpopulation can be biochemically investigated.

Morphological analysis of the growth stages of in-vivo mouse hair follicles by using optical coherence tomography

Swept-source optical coherence tomography (SS-OCT), a bio-photonic imaging modality, was used to demonstrate an initial feasibility experiment for detecting morphological variations of in-vivo mouse hair follicles for the anagen and the telogen growth stages. Two C57BL/6 adult male mice, one undergoing the anagen stage and the other undergoing the telogen stage of the hair follicle growth cycle, were selected for the experiment. The OCT cross-sectional images of mice skin were acquired in-vivo within an interval of 15 days, and the observed morphological changes were analyzed. The micro-structural features of mice skin on the 15th experimental day were further compared with corresponding histological observations. The preliminary result of this study provides clear insights into the structural details of mouse skin, confirming the resemblance of the OCT images with the corresponding histological measurements, and ensures the suitability of SS-OCT for non-invasive analysis of hair follicle conditions.

A novel energy conversion method based on hydrogel material for self-powered sensor system applications

In this paper, a novel energy conversion method based on hydrogel material for self-powered sensor system applications is proposed, which can harvest energy from environment vibrations and supply power to sensors without any external power source. In this approach, hemispherical hydrogel arrays are positioned between two parallel-arranged conductive plates. The deformation of hydrogel arrays caused by ambient vibrations will result in non-equilibrium charge distribution in the conductive plates. The charge redistribution leads to electrons transfer, thereby converting mechanical vibration energy into electricity. Based on this energy conversion principle, a hydrogel-based energy harvester is fabricated and experimentally characterized. The fabricated device exhibits a superwide working bandwidth (0–80Hz) and high reliability in power generation. Moreover, favorable adaptability of the tilt angle during installation is achieved. In the feasibility experiment, an LCD screen is operated to verify the potential of the hydrogel-based energy conversion method to self-powered sensor applications under vibration environment. Finally, a visualized self-powered force sensor is also demonstrated with the fabricated hydrogel-based energy harvester, which proves its great potential in various application fields.

Proton Radiography With Timepix Based Time Projection Chambers.

The development of a proton radiography system to improve the imaging of patients in proton beam therapy is described. The system comprises gridpix based time projection chambers, which are based on the Timepix chip designed by the Medipix collaboration, for tracking the protons. This type of detector was chosen to have minimal impact on the actual determination of the proton tracks by the tracking detectors. To determine the residual energy of the protons, a BaF 2 crystal with a photomultiplier tube is used. We present data taken in a feasibility experiment with phantoms that represent tissue equivalent materials found in the human body. The obtained experimental results show a good agreement with the performed simulations.

Wavelet PWM Technique for Single-Phase Three-Level Inverters

The wavelet PWM (WPWM) technique has been applied in two-level inverters successfully, but directly applying the WPWM technique to three-level inverters is impossible. This paper proposes a WPWM technique suitable for a single-phase three-level inverter. The work analyzes the control strategy with the WPWM and obtains the design of its parameters. Compared with the SPWM technique for a single-phase three-level inverter under the same conditions, the WPWM can obtain high magnitudes of the output fundamental frequency component, low total harmonic distortion, and simpler digital implementation. The feasibility experiment is given to verify of the proposed WPWM technique.

First experience with single-source dual-energy computed tomography in six patients with acute arthralgia: a feasibility experiment using joint aspiration as a reference.

Dual-energy computed tomography (DECT) is an emerging imaging technique for examining patients with suspected gout. Single-source dual-energy CT (S-DECT) is a new way of obtaining DECT information on conventional CT scanners rather than using special dual-source CT systems. We tested the feasibility of S-DECT (320-row CT; Aquilion ONE, Toshiba Medical Systems, Otawara, Japan) in 6 patients (5 men, 1 woman; mean age 61.3, range 48 to 69 years) with acute arthralgia and suspected gout, and compared the S-DECT findings with the results of joint aspiration. Three patients had a diagnosis of gouty arthritis with negatively birefringent crystals in synovial fluid, in addition to gouty tophi in S-DECT. Three patients had no detectable crystals by polarization microscopy and no tophi on DECT. Their final diagnoses were rheumatoid arthritis, activated osteoarthritis, and septic arthritis in one case each. This initial experience suggests that S-DECT might be a valuable alternative to dual-source CT. Hence, more patients may benefit from its additional diagnostic abilities in the future.

Feasibility experiment on the simple hot box-heat flow meter method and the optimization based on simulation reproduction

This paper proposes a simple hot box-heat flow meter method (SHB-HFM) and verifies its feasibility by an in-situ measurement of wall thermal transmittance. The experimental results show that even under very unfavorable test conditions, the test error of the wall thermal transmittance by the SHB-HFM is only −5.97% relative to the design value, which proves that the SHB-HFM has the adequate test accuracy, thereby proving that this method is feasible. And through arranging reference test sensors, 15 cm up and down from the central primary test sensors, the test errors due to location deviation increase to −8.14% and −9.60% respectively, which basically meets the accuracy requirement and thereby demonstrates the SHB-HFM has an acceptable tolerance for the in-situ operation. To further explore the influence of various factors on the test accuracy, a mathematical model is established and verified by the experimental data. The simulation results indicate that the perfect in-situ measurement conditions do not improve the measurement accuracy obviously, while moderately enlarging the box dimensions or simultaneously arranging heat flow meters on the inner and outer surfaces is more effective in improving the test accuracy.

The enhancement of ammonium removal from ethanolamine wastewater using air-cathode microbial fuel cells coupled to ferric reduction

A microbial fuel cell (MFC) with biological Fe(III) reduction was implemented for simultaneous ethanolamine (ETA) degradation and electrical energy generation. In the feasibility experiment using acetate as a substrate in a single-chamber MFC with goethite and ammonium at a ratio of 3.0(mol/mol), up to 96.1% of the ammonium was removed through the novel process related to Fe(III). In addition, the highest voltage output (0.53V) and maximum power density (0.49Wm−2) were obtained. However, the ammonium removal and electrical performance decreased as acetate was replaced with ETA. In the long-term experiment, the electrical performance markedly decreased where the voltage loss increased due to Fe deposition on the membranes.

Laser Prestressed Bending of Titanium Alloy Sheet

The new method of laser prestressed bending of Titanium alloy sheet is put forward in this paper. Titanium alloy sheet is produced pre-deformation by a clamp, the laser beam with some certain intensity scans its surface along the given path, and it is formed due to the thermal effect of the laser to reduce the yield strength of the scanning area and enhance its plastic deformation ability. A feasibility experiment for Ti-6Al-4V sheet is done and the bending effect is remarkable. Laser prestressed bending mechanism is described and the main influence factors are analyzed.

Fluoroscopy-based laser guidance system for linear surgical tool insertion depth control.

In most orthopedic surgeries, knowing how far to insert surgical tools is crucial. The objective of this study was to provide guidance information on depth without tracking surgical tools. A previously developed laser guidance system for linear surgical tool insertion uses two laser beams that display the insertion point and orientation on the skin surface. However, the system only provides 4 degrees of freedom guidance (an entry point on the planned pathway line and the orientation) but do not inform surgeons on the ideal insertion depth. A 5-DOF guidance method was developed to provide guidance information by direct projection onto the surgical area using laser beams without tracking markers. A position and orientation guidance performed by two laser beams and depth guidance performed by a single laser beam are appeared on the surgical area in turn. However, depth point appears on the surgical tool side face with some error because of tool radius. Using the actual depth position, insertion path vector and location of the laser sources, the correct depth point on the tool's surface is calculated by the proposed method. So, this system can indicate and navigate the 5-DOF which is planning path and the correct depth point. An evaluation of the accuracy of depth guidance revealed a depth guidance error of 0.55±0.29 mm and results from phantom target insertions revealed overall system accuracies of 1.44 ± 1.09 mm, 0.91° ± 0.82°. In addition, overall system accuracies of application feasibility experiment under the X-ray condition were 1.94 ± 0.98mm, 1.39° ± 1.30°. A new surgical tool depth insertion method was developed using a fluorolaser guidance system. This tool informs surgeons of the surgical tool tip depth assuming that the insertion point and orientation are correct. The new method was tested successfully in vitro.