Assessment of the Structural Vibration Effect on Plasma Current Measurement Using a Fiber Optic Current Sensor in ITER.

In this paper, we assess the effect of cryostat bridge vibrations on the plasma current measurement accuracy when using a fiber optic current sensor (FOCS) in ITER. The impact of vibrations on the light polarization state was first experimentally investigated using a miniaturized mock-up which represented a relevant part of the ITER FOCS structure. The set-up was then numerically simulated using the Jones matrix approach. Equivalent vibration matrices obtained from the experiment were used in the simulations to determine the effect of the vibrations on the FOCS accuracy. It is demonstrated that although the vibrations imply some changes in the polarization state, this effect can be strongly reduced when a proper low-birefringent spun optical fiber is used. The ITER requirement regarding the plasma current measurement accuracy can therefore be fulfilled.

Compact solid-state optical phased array beam scanners based on polymeric photonic integrated circuits.

Optical phased array (OPA) devices are being actively investigated to develop compact solid-state beam scanners, which are essential in fields such as LiDAR, free-space optical links, biophotonics, etc. Based on the unique nature of perfluorinated polymers, we propose a polymer waveguide OPA with the advantages of low driving power and high optical throughput. Unlike silicon photonic OPAs, the polymer OPAs enable sustainable phase distribution control during beam scanning, which reduces the burden of beamforming. Moreover, by incorporating a tunable wavelength laser comprising a polymer waveguide Bragg reflector, two-dimensional beam scanning is demonstrated, which facilitates the development of laser-integrated polymeric OPA beam scanners.

Polymeric tunable wavelength filter with two-stage cascaded tilted Bragg gratings.

Wavelength-division multiplexed optical communication systems used in 5G networks require tunable wavelength filters with narrow bandwidth for 100 GHz channel spacing, wide wavelength range to cover 16 channels, and a side mode suppression ratio (SMSR) exceeding 30 dB. To fabricate wavelength filters satisfying these specifications, tunable Bragg grating filters based on polymeric optical waveguides are proposed. The combination of mode-sorting waveguide and tilted Bragg grating enables the extraction of Bragg reflected signals to another path, without using an external circulator. Moreover, the double reflection by the two-stage cascaded structure produces narrower reflection bandwidth, improved SMSR characteristics, and reduced adjacent-channel crosstalk through the suppression of undesired mode coupling. The proposed device exhibits a 20 dB bandwidth of 1.0 nm and SMSR of 35 dB, over the entire wavelength-tuning range.

Silicon nitride optical phased array based on a grating antenna enabling wavelength-tuned beam steering.

An optical phased array (OPA) in silicon nitride (SiN) is conspicuously highlighted as a vital alternative to its counterpart in silicon. However, a limited number of studies have been conducted on this array in terms of wavelength-tuned beam steering. A SiN OPA has been proposed and implemented with a grating antenna that incorporated an array of shallow-etched waveguides, rendering wavelength-tuned beam steering along the longitudinal direction. To accomplish a superior directionality on a wavelength-tuned beam steering, the spectral beam emission characteristics of the antenna have been explored from the viewpoint of a planar structure that entails a buried oxide (BOX), a SiN waveguide core, and an upper cladding. Two OPA devices having substantially different thicknesses of the resonant cavities, established by combining the BOX and SiN core, were considered theoretically and experimentally to scrutinize the spectral emission characteristics of the antenna on beam steering. Both of the fabricated OPA devices steered light by an angle of 7.4° along the longitudinal direction for a wavelength ranging from 1530 to 1630 nm, while they maintained a divergence angle of 0.2°×0.6° in the longitudinal and lateral directions. Meanwhile, the OPA fabricated on a substantially thick BOX layer featured a limited steering performance to attain a stabilized response over a broad spectral region. We examined the influence of the cavity thickness on the spectral response of the antenna in terms of optical thickness. Based on the two antenna characteristics, it was confirmed that the grating antenna emitted the beam with a higher efficiency when the optical thickness of the cavity corresponded to odd integer multiples of the quarter wavelength. This work is a considerable strategy for designing a stabilized SiN OPA over a desired spectral region.

Temporal response of polymer waveguide beam scanner with thermo-optic phase-modulator array.

Solid-state light detection and ranging, capable of performing beam scanning without using any mechanical moving parts, requires a phase-modulator array. Polymers facilitate the fabrication of efficient phase modulators with low drive power, owing to their high thermo-optic (TO) effect and low thermal conductivity. We designed and fabricated a polymeric phase-modulator array and analyzed the temporal response of the TO phase modulator. The frequency response of the phase modulator was measured for a Mach-Zehnder interferometer (MZI), and the transfer function was modeled in terms of multiple poles and zeros. The frequency response of a fabricated beam-scanning device incorporating the TO phase modulator was also measured. The temporal response of the beam scanner was confirmed to coincide well with that of the MZI modulator. The device exhibited a fast rise time of 12 ms, accompanied by slight power variations appearing for a long period (over hundreds of seconds), which originated from the inherent viscoelastic effect of the polymer materials.

Imaging appearance following surgical decompression of the ulnar nerve.

Ulnar neuropathy at the elbow is the second most common entrapment neuropathy of the upper extremity. Yet, there is a paucity of literature focusing on the imaging appearance following surgical decompression of the ulnar nerve at the elbow. Diagnostic imaging studies obtained after surgical decompression at The University of Michigan were reviewed and imaging findings were documented. We aim to describe the various techniques of ulnar nerve decompression and corresponding post-operative appearance on imaging. Potential complications following decompression will also be described with imaging and clinical correlation of recalcitrant ulnar neuropathy. It is important for the radiologist who performs MRI or ultrasound of the elbow to be aware of the various ulnar nerve decompression procedures. This knowledge will facilitate rapid and accurate diagnosis of normal and abnormal appearance of the ulnar nerve in this context.

Sonography of Wrist Ganglion Cysts: Which Location Is Most Common?

OBJECTIVES: The literature states that wrist ganglion cysts are most commonly dorsal; however, our experience suggests a volar location is more common. The purpose of this study was to identify the locations of ganglion cysts of the wrist as imaged with sonography. METHODS: After Institutional Review Board approval with informed consent waived, retrospective review of wrist sonography reports from January to April 2016 was completed. Only patients who had a comprehensive evaluation that included the dorsal and volar wrist were included. Ultrasound images were reviewed to characterize wrist ganglion cysts. RESULTS: The study group consisted of 98 subjects (78% female, 22% male) (median age, 51 years; range 13-79) with 124 wrist ganglion cysts, where 69% (86 of 124) were volar and 31% (38 of 124) were dorsal. Ganglion cysts were located between the radial artery and flexor carpi radialis in 63% (78 of 124), followed by a dorsal location superficial to the scapholunate ligament in 20% (25 of 124), other dorsal locations in 11% (13 of 124), and other volar locations in 6% (8 of 124). With dorsal ganglion cysts, the scapholunate ligament when imaged appeared normal in 91% (20 of 22). Ganglion cysts were multilocular/multilobular in all subjects. CONCLUSIONS: The most common location for wrist ganglion cysts is in the volar wrist, particularly between the radial artery and flexor carpi radialis tendon, appearing multilocular or multilobular with a mean largest dimension of 1.0 cm. Given the propensity of ganglion cysts to occur at this site, attention to this area when imaging the wrist with sonography or magnetic resonance imaging should be considered.

Polymer waveguide WDM channel selector operating over the entire C and L bands.

A tunable channel selector operating over both the C and L bands of wavelength-division-multiplexing optical network is proposed based on a thermo-optic tunable Bragg grating device in a polymer waveguide. A tilted Bragg grating cascaded with an asymmetric Y-branch waveguide effectively implements a small Bragg-reflection wavelength filter that does not require an external circulator. To increase the operating wavelength span of the channel selector, two Bragg gratings with different periods are fabricated on a single substrate for covering C and L bands, respectively. A wide tuning range over 80 nm along with a narrow bandwidth is demonstrated. Moreover, the polarization dependence of the reflection spectrum is observed to be less than 0.1 nm.

Musculoskeletal ultrasound: athletic injuries of the lower extremity.

Athletic injuries of the lower extremities are commonly encountered in clinical practice. While some pathology can be diagnosed on physical exam, others are a clinical dilemma with nonspecific symptomatology. In these situations, ultrasound imaging can be utilized as an exceptional diagnostic tool, offering unique advantages over other imaging modalities. This article will review the imaging characteristics of commonly encountered athletic injuries of the lower extremity.

Allopregnanolone Effects on Transmission in the Brain Stem Solitary Tract Nucleus (NTS).

During pregnancy, the progesterone metabolite, allopregnanolone (ALLO), becomes elevated and has been associated with altered levels within the CNS and resulting changes in GABAA receptor function. Pregnant animals poorly compensate reflexes for a decrease in blood pressure during hemorrhage. Previous works suggested that ALLO decreases baroreflex responses by central actions, however, the underlying mechanisms are poorly understood. In this study, we tested ALLO actions on visceral afferent synaptic transmission at second-order neurons within medial portions of the nucleus tractus solitarius (NTS) using hindbrain slices from non-pregnant female rats. Solitary tract (ST) stimulation-evoked excitatory postsynaptic currents (ST-eEPSCs) in NTS neurons directly connected to vagal afferents within the ST. ST-eEPSCs were functionally identified as monosynaptic by the latency characteristics (low jitter = standard deviation of latency, ≤200 µs) to ST stimulation. Such second-order neurons all displayed spontaneous inhibitory postsynaptic currents (sIPSCs), and low micromolar concentrations of ALLO increased frequency and decay time. At submicromolar concentrations, ALLO induced a tonic, GABAergic inhibitory current and suppressed ST-eEPSCs' amplitude. While GABAA receptor antagonist, bicuculline, blocked all ALLO effects, gabazine only blocked sIPSC actions. In current-clamp mode, ALLO perfusion increased failure of ST stimulation to trigger action potentials in most neurons. Thus, our results indicate that ALLO acts to suppress visceral afferent ST synaptic transmission at first synapses by activating pharmacologically distinct GABAA subtypes at different concentration ranges. This ALLO-mediated attenuated visceral afferent signal integration in NTS may underlie reflex changes in blood pressure during gestation.

Optical Waveguide Tunable Phase Delay Lines Based on the Superior Thermo-Optic Effect of Polymer.

Strong thermo-optic effect of polymers is useful for fabricating tunable phase-delay devices with low power consumption and wide tuning range. However, if the temperature change is increased to extend the tuning range, an attenuation of the guided light is accompanied by the refractive index gradient across the waveguide core. For three different waveguide structures, in this study, the optimal structure of the device for a variable phase delay line was found by investigating the attenuation and interference phenomena accompanying phase modulation. By improving the uniformity of thermal distribution across the waveguide core, a phase delay of 130π rad was obtained with an output attenuation less than 0.5 dB.

GAREM1 regulates the PR interval on electrocardiograms.

PR interval is the period from the onset of P wave to the start of the QRS complex on electrocardiograms. A recent genomewide association study (GWAS) suggested that GAREM1 was linked to the PR interval on electrocardiograms. This study was designed to validate this correlation using additional subjects and examined the function of Garem1 in a mouse model. We analyzed the association of rs17744182, a variant in the GAREM1 locus, with the PR interval in 5646 subjects who were recruited from 2 Korean replication sets, Yangpyeong (n = 2471) and Yonsei (n = 3175), and noted a significant genomewide association by meta-analysis (P = 2.39 × 10-8). To confirm the function of Garem1 in mice, Garem1 siRNA was injected into mouse tail veins to reduce the expression of Garem1. Garem1 transcript levels declined by 53% in the atrium of the heart (P = 0.029), and Garem1-siRNA injected mice experienced a significant decrease in PR interval (43.27 ms vs. 44.89 ms in control, P = 0.007). We analyzed the expression pattern of Garem1 in the heart by immunohistology and observed specific expression of Garem1 in intracardiac ganglia. Garem1 was expressed in most neurons of the ganglion, including cholinergic and adrenergic cells. We have provided evidence that GAREM1 is involved in the PR interval of ECGs. These findings increase our understanding of the regulatory signals of heart rhythm through intracardiac ganglia of the autonomic nervous system and can be used to guide the development of a therapeutic target for heart conditions, such as atrial fibrillation.

Bias-free optical current sensors based on quadrature interferometric integrated optics.

A reflective quadrature interferometer was constructed by integrating polymeric optical waveguide components, to demonstrate an optical current sensor that could operate without bias feedback control. In order to obtain two interference signals with a phase difference of 90°, half-wave and quarter-wave plates were inserted in the polymeric optical waveguide chip, and a polarization-dependent birefringence modulator was used for the initialization of the optical sensor, including detector gain adjustment. During the bias-free operation of the sensor, the measurement error was less than ± 0.2%, and it was confirmed that the sensor output was stable for 15 h even if the operating point was not maintained.

The Long-Term Course of Outcomes for Lumbar Intervertebral Disc Herniation following Integrated Complementary and Alternative Medicine Inpatient Treatment: A Prospective Observational Study.

A prospective observational study was conducted in 524 lumbar intervertebral disc herniation (LDH) inpatients to report the long-term effects of complementary and alternative medicine (CAM) treatment. Participants received integrative CAM treatment during hospitalization, from June 2012 to May 2013, and long-term outcomes were assessed from July to August 2016. Numerical rating scales (NRSs) of back and leg pain, the Oswestry disability index (ODI), satisfaction, surgery, recurrence, and current care status were investigated. Baseline characteristics were analyzed to determine factors that predicted long-term satisfaction. A total of 367 patients were available for follow-up. The long-term change in NRS of back and leg pain and ODI was 3.53 (95% CI, 3.22, 3.83), 2.72 (2.34, 3.11), and 32.89 (30.21, 35.57), respectively, showing that improvements were well sustained. Regarding satisfaction, 86.11% responded that they were "slightly improved" or better. Range of lumbar flexion ≤ 60° and both legs' pain at admission were significant predictors of "much improved" or better satisfaction in the long term. Overall, LDH patients who received CAM treatment maintained favorable states in the long term. However, as an uncontrolled observational study, further studies with placebo and/or active controls are warranted. Trial Registration. This trial is registered with ClinicalTrials.gov NCT02257723 (date of registration: October 2, 2014).

Csk Regulates Blood Pressure by Controlling the Synthetic Pathways of Aldosterone.

BACKGROUND: Blood pressure is regulated by a network of diverse physiological pathways. The C-terminal Src kinase (CSK) locus (15q24) is associated with blood pressure in various ethnic groups. It was recently reported thatCskinsufficiency increases blood pressure through Src. The mechanisms of hypertension inCsk+/-mice are examined further in this study.Methods and Results:To identify a causal component responsible for hypertension inCsk+/-, the heart rate was measured by electrocardiogram and plasma volume by Evans blue dilution. Plasma volume increased inCsk+/-compared with wild-types, while the heart rate did not change. Plasma sodium and aldosterone levels rose consistently inCsk+/-vs. wild-types, and spironolactone, a mineralocorticoid receptor antagonist, reduced blood pressure. The amounts of Sgk1 and Na+/K+-ATPase (NKA) increased in the kidney ofCsk+/-compared with wild-types. It was also found that Cyp11b2 (aldosterone synthase) was upregulated in the adrenal glands ofCsk+/-, and that Csk was enriched in the zona glomerulosa of adrenals, the major site of aldosterone production in the normal mouse. CONCLUSIONS: The results of the present study identify a physiological pathway by which blood pressure is regulated, in which the insufficiency ofCskinduces aldosterone production with zonal specificity in the adrenal glands, increasing sodium reabsorption and plasma volume and thus resulting in hypertension.

CFL-1, a novel F-box protein with leucine-rich repeat may interact with UNC-10 for the regulation of defecation and daumone response in Caenorhabditis elegans.

Previously we reported that CFL-1, the single LRR-type F-box protein in the Caenorhabditis elegans genome, affected defecation behavior and daumone response. CFL-1 is highly homologous to the FBXL20 in mammals, which regulates synaptic vesicle release by targeting its substrate Rim1 for ubiquitin-mediated degradation. The worm homolog of Rim1 is UNC-10, a presynaptic membrane protein that triggers synaptic vesicle fusion through interaction with RAB-3 GTPase. To examine if CFL-1 exerts its modulatory effect on the defecation and daumone response via ubiquitination of UNC-10, we performed RNAi knock-down of CFL-1 in the unc-10(e102) mutant background. We noticed additive increase in defecation interval when the activities of both CFL-1 and UNC-10 were compromised. Also, the degree of dauer formation upon daumone treatment in unc-10 mutants treated with CFL-1 RNAi decreased further than the level observed in untreated mutants or wild type N2 worms with CFL-1 RNAi knock-down. Our data suggest that CFL-1 affects defecation frequency and daumone response in C. elegans through the ubiquitination of UNC-10.

Ultrasound-Guided Percutaneous Tenotomy.

Of the many treatment options for tendinopathy, percutaneous tenotomy has been used throughout the body with success. With this procedure, a needle is repeatedly passed into the abnormal tendon with the goal of converting a chronic degenerative process to an acute inflammatory condition that will progress to tendon healing. Ultrasound guidance for this procedure is essential to ensure that the abnormal region of the tendon is accurately targeted. The treatment has few contraindications, and negligible complications have been described. This article reviews the rationale behind tenotomy for the treatment of tendinopathy and the ultrasound-guided technique. The current literature comparing the results of tenotomy to other percutaneous tendon treatments is also reviewed, although many of the other tendon injection treatments incorporate tenotomy as part of the procedure.

Tumors and Tumor-like Abnormalities of the Midfoot and Forefoot.

The differential diagnosis for a midfoot or forefoot mass or mass-like abnormality includes several common benign and malignant pathologies. Evaluation with imaging can often provide a diagnosis, or at least several likely etiologies, and guide management. Determining if a mass is cystic or solid with ultrasound or MRI can limit the differential diagnosis. Identifying the abnormality at a specific anatomical site, such as a bursa, peripheral nerve, plantar aponeurosis, or tendon, can often suggest a correct diagnosis. Correlation with radiography is essential to determine potential osseous origin or involvement and further characterize matrix mineralization. Imaging evaluation can effectively characterize a mass or mass-like abnormality of the midfoot or forefoot, which can provide a precise or limited differential diagnosis and guide further management for biopsy or other treatment.

Integrated-optic current sensors with a multimode interference waveguide device.

Optical current sensors based on polarization-rotated reflection interferometry are demonstrated using polymeric integrated optics and various functional optical waveguide devices. Interferometric sensors normally require bias feedback control for maintaining the operating point, which increases the cost. In order to resolve this constraint of feedback control, a multimode interference (MMI) waveguide device is integrated onto the current-sensor optical chip in this work. From the multiple outputs of the MMI, a 90° phase-shifted transfer function is obtained. Using passive quadrature demodulation, we demonstrate that the sensor could maintain the output signal regardless of the drift in the operating bias-point.

Gene Silencing and Haploinsufficiency of Csk Increase Blood Pressure.

OBJECTIVE: Recent genome-wide association studies have identified 33 human genetic loci that influence blood pressure. The 15q24 locus is one such locus that has been confirmed in Asians and Europeans. There are 21 genes in the locus within a 1-Mb boundary, but a functional link of these genes to blood pressure has not been reported. We aimed to identify a causative gene for blood pressure change in the 15q24 locus. METHODS AND RESULTS: CSK and ULK3 were selected as candidate genes based on eQTL analysis studies that showed the association between gene transcript levels and the lead SNP (rs1378942). Injection of siRNAs for mouse homologs Csk, Ulk3, and Cyp1a2 (negative control) showed reduced target gene mRNA levels in vivo. However, Csk siRNA only increased blood pressure while Ulk3 and Cyp1a2 siRNA did not change it. Further, blood pressure in Csk+/- heterozygotes was higher than in wild-type, consistent with what we observed in Csk siRNA-injected mice. We confirmed that haploinsufficiency of Csk increased the active form of Src in Csk+/- mice aorta. We also showed that inhibition of Src by PP2, a Src inhibitor decreased high blood pressure in Csk+/- mice and the active Src in Csk+/- mice aorta and in Csk knock-down vascular smooth muscle cells, suggesting blood pressure regulation by Csk through Src. CONCLUSIONS: Our study demonstrates that Csk is a causative gene in the 15q24 locus and regulates blood pressure through Src, and these findings provide a novel therapeutic target for the treatment of hypertension.