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We developed a low-vibrational-noise cooling configuration using continuous liquefaction of evaporated helium gas from a multi-channel SQUID gradiometer system for whole-head magnetoencephalography (MEG) measurements. The initial reduction of the vibration of the cryocooler was done by rigidly mounting the remote motor and cold head chamber on a concrete wall. This significantly reduces transmission of vibrations to the transfer tube, especially compared with mounting them on vertical aluminum frames. In addition, to reduce vibrations from a mechanical SQUID array insert, we completely eliminated it by mounting each SQUID gradiometer separately on the helmet surface within the vacuum space. Thus, vibrations from the boiling liquid helium and transmission from the transfer tube were both greatly reduced. Magnetic field noise of the 150-channel SQUID gradiometer system showed that the vibration-induced interference peaks are comparable in amplitude to those from a conventional MEG system without helium reliquefaction.

A thermoelectric coated grain nanocomposite CuInTe2/SnTe with eco-friendly elements was synthesized. The nanocomposite contains a coating layer of CuInTe2 and SnO2 at the grain boundaries of the SnTe matrix. The coating layer was synthesized using the cation exchange process considering the hard soft acid base (HSAB) concept, the solubility product, and crystal structure. The CuInTe2 coating layer blocks the low energy carriers of the composite resulting in 40% enhancement of the Seebeck coefficient due to energy filtering. The coherent phonon scattering by the coating layer of CuInTe2 effectively reduces the lattice thermal conductivity to almost the minimum theoretical limit. The thermoelectric figure of merit (zT) for the CuInTe2/SnTe nanocomposite was as high as 1.68 at 823 K, which is significantly higher than that of bulk SnTe in the mid-temperature range. The average zT from 373 K to 823 K for the nanocomposite was 0.76, which is promising for utilization in industrial application.

Background: Few studies have reported the outcomes of primary volar locking plate fixation in Gustilo and Anderson type II and IIIA open distal radius fractures. We report the outcomes of treatment of Gustilo and Anderson type II and IIIA open distal radius fractures using primary volar locking plate fixation. Methods: We retrospectively reviewed 24 patients with open distal radius fractures who were treated using primary volar locking plate fixation. The range of motion (ROM) and modified Mayo wrist scores were measured to assess functional outcomes. Radiological outcomes included the bone union period, radial inclination, volar tilt, radial length and ulnar variance. Results: Functional outcomes, including mean ROM in flexion (39.1°) and extension (52.5°), improved following primary volar locking plate treatment. Radiological outcomes were as follows. Mean bone union period, radial length and ulnar variance were 7.8 months, 10.4 and 0.7 mm, respectively. Two patients had superficial wound infection 2 weeks after surgery and one patient had non-union of the radius that required implant removal, autologous iliac crest bone graft and plate re-fixation. Conclusions: Primary volar locking plate fixation is a safe and reliable treatment option for Gustilo and Anderson type II and IIIA open distal radius fractures. By providing firm stabilisation and allowing early ROM exercise, primary volar locking plate fixation resulted in good functional and radiological outcomes. Level of Evidence: Level IV (Therapeutic)

Magnetoencephalography (MEG) is a functional neuroimaging technique that noninvasively detects the brain magnetic field from neuronal activations. Conventional MEG measures brain signals using superconducting quantum interference devices (SQUIDs). SQUID-MEG requires a cryogenic environment involving a bulky non-magnetic dewar and the consumption of liquid helium, which restricts the variability of the sensor array and the gap between the cortical sources and sensors. Recently, miniature optically pumped magnetometers (OPMs) have been developed and commercialized. OPMs do not require cryogenic cooling and can be placed within millimeters from the scalp. In the present study, we arranged six OPM sensors on the temporal area to detect auditory-related brain responses in a two-layer magnetically shielded room. We presented the auditory stimuli of 1-kHz pure-tone bursts with 200-ms duration and obtained the M50 and M100 components of auditory evoked fields. We delivered the periodic stimuli with a 40-Hz repetition rate and observed the gamma-band power changes and inter-trial phase coherence of auditory steady-state responses at 40 Hz. We found that the OPM sensors have a performance comparable to that of conventional SQUID-MEG sensors, and our results suggest the feasibility of using OPM sensors for functional neuroimaging and brain–computer interface applications.

AimsThe purpose of this study was to evaluate the relationships between the degree of injury to the medial and lateral collateral ligaments (MCL and LCL) and associated fractures in patients with a posterolateral dislocation of the elbow, using CT and MRI.MethodsWe retrospectively reviewed 64 patients who presented between March 2009 and March 2018 with a posterolateral dislocation of the elbow and who underwent CT and MRI. CT revealed fractures of the radial head, coronoid process, and medial and lateral humeral epicondyles. MRI was used to identify contusion of the bone and collateral ligament injuries by tear, partial or complete tear.ResultsA total of 54 patients had a fracture; some had more than one. Radial head fractures were found in 25 patients and coronoid fractures in 42. Lateral and medial humeral epicondylar fractures were found in eight and six patients, respectively. Contusion of the capitellum was found in 43 patients and rupture of the LCL was seen in all patients (partial in eight and complete in 56), there was complete rupture of the MCL in 37 patients, partial rupture in 19 and eight had no evidence of rupture. The LCL tear did not significantly correlate with the presence of fracture, but the MCL rupture was complete in patients with a radial head fracture (p = 0.047) and there was significantly increased association in those without a coronoid fracture (p = 0.015).ConclusionIn posterolateral dislocation of the elbow, LCL ruptures are mostly complete, while the MCL exhibits various degrees of injury, which are significantly associated with the associated fractures. Cite this article: Bone Joint J 2020;102-B(2):227–231.

Differentiating central vestibulopathy from more common vestibular disorders is crucial because it often necessitates different treatment strategies, and early detection can help to minimize potential complications. Isolated nodular infarct is one of the central brain lesions that can mimic peripheral vertigo. We present a case of isolated nodular infarct that had been misdiagnosed as vestibular neuritis on the contralateral side at the initial evaluation. The patient was successfully treated with anticoagulants and antihyperlipidemic agents. Clinicians should keep in mind that some causes of central vertigo mimic peripheral vestibulopathy at the early stage.

The hippocampus is one of the most metabolically active regions of the brain; therefore, it may be affected by various acute disorders. This study aimed to introduce and categorize various acute conditions that can involve the hippocampus and explain the findings of MRI, especially diffusion-weighted imaging (DWI). Acute hippocampal disorders are divided into six categories: infection, inflammation, metabolic, ischemic, traumatic, and miscellaneous. In this study, patients were retrospectively reviewed based on clinical findings and MRI, especially DWI. All diseases had been confirmed clinically or pathologically. Many acute hippocampal disorders overlap with the clinical manifestations. Thus, it is necessary to categorize acute hippocampal lesions and understand their specific imaging findings for differential diagnosis.해마는 뇌에서 가장 대사가 활발한 부위 중 하나이다. 그러므로 해마는 다양한 급성기 질환으로부터 영향을 받을 수 있다. 이 연구의 목적은 해마와 관련된 다양한 질환들을 소개 및 분류하며 특히 확산강조영상을 중심으로 자기공명영상 소견에 대해 설명하는 것이다. 급성기 해마 질환은 감염, 염증, 대사성, 허혈성, 외상성 그리고 기타 총 6가지로 분류하였다. 환자들은 임상적 소견 그리고 확산강조영상 중심의 자기공명영상을 토대로 후향적으로 검토되었다. 모든 질환들은 임상적 또는 병리학적으로 진단되었다. 급성기 해마 질환들은 임상 양상이 겹치는 경우가 많다. 그러므로 감별 진단을 위해서 급성기 해마 질환들을 분류하고 각각의 특징적인 영상 소견을 이해하는 것이 중요하다.

In this chapter, we design and fabricate a 52GHz frequency synthesizer for 60GHz dualconversion receiver using SiGe BiCMOS process technology. The designed PLL-based frequency synthesizer consists of a 26-GHz PLL and a 52-GHz frequency doubler. In the

Ideal electromagnetic (EM) wave absorbers can absorb all incident EM waves, regardless of the incident direction, polarization, and frequency. Absorptance and reflectance are intrinsic material properties strongly correlated with electrical conductivity; hence, achieving perfect absorptance with zero reflectance is challenging. Herein, we present a design strategy for preparing a nearly ideal EM absorber based on a layered metal that maximizes absorption by utilizing multiple internal reflections and minimizes reflection using a monotonic gradient of intrinsic impedance. This approach was experimentally verified using aluminum nanoflakes prepared via topochemical etching of lithium from Li9Al4, and the impedance-graded structure was obtained through the size-based sorting behavior of aluminum nanoflakes sinking in dispersion. Unlike in traditional shielding materials, strong absorption (26.76 dB) and negligible reflectivity (0.04 dB) with a ratio of >103 can be achieved in a 120 μm thick film. Overall, our findings exhibit potential for developing a novel class of antireflective shielding materials.

Topological crystal insulator (TCI) and topological Dirac semimetals have topologically nontrivial surface and bulk state, respectively. The parent compound of Pb0.5Sn0.5Te exhibiting TCI band inversion has particle-hole symmetry owing to the gapless Dirac band implying a strong electron–hole bipolar compensation in Seebeck coefficient. We recently reported that weak perturbation of TCI state can enhance thermoelectric performance significantly due to highly dispersive and degenerated energy bands. It is a great interest that the further increase of chemical potential has beneficiary to thermoelectric performance in the vicinity of topological phase transition. Here we investigate the thermoelectric properties of the co-doping effect by K and Se in (Pb0.5Sn0.5)1−xKxTe0.95Se0.05 (x = 0.0, 0.005, 0.010, 0.015, 0.02) compounds. K-doping increases the band gap from 0.15 eV (Pb0.5Sn0.5Te) to 0.21 eV (x = 0.05) as well as increasing chemical potential resulting in the suppression of bipolar diffusion effect. In spite of the suppression of bipolar diffusion effect by K-doping, the power factor in K-doped compound is decreased significantly than the one of non-doped Pb0.5Sn0.5Te0.95Se0.05 compound. It indicates that when we increase chemical potential further on the breaking of topological band inversion, the thermoelectric performance is deteriorated because the chemical potential resides far from the linear band dispersions which become conventional material. The ZT for the K-doped (Pb0.5Sn0.5)1−xKxTe0.95Se0.05 is obtained as 0.91 at 750 K for x = 0.017 which is increased as much as 99% comparing to the pristine compound Pb0.5Sn0.5Te but it is reduced value (51.5%) comparing to those of Pb0.5Sn0.5Te0.95Se0.05 compound. We believe that this research is valuable on the confirmation that the weak perturbation of topological state and appropriate chemical potential tuning are important criteria in high thermoelectric performance.

Fifth generation mobile networks will be designed to utilize the benefits of the large available bandwidth in the mmWave spectrum. Commercialization of 5G mmWave technology will be launched soon, due to progress in RF hardware and large efforts on integration of mmWave beamforming technologies in standardization bodies such as 3GPP. The main challenges of mmWave mobility in 5G result from the impact of fast-varying channels on beamforming systems. However, the corresponding feasibility has not yet been fully investigated. In this article we first identify and review the technical challenges that remain in 5G mmWave mobile networks. We then present sample measurements of outdoor mmWave channels, and emulate the mobile system operation in them. We discuss insights, based on these results, on under what circumstances supporting mmWave mobility is feasible.