Optical trapping in micro- and nanoconfinement systems: Role of thermo-fluid dynamics and applications

In this mini-review, recent advances on the role of a focused laser in micro- and nanofluidic systems is widely introduced with special interest in thermo-fluid dynamical aspects and their importance in optical manipulation. As a brief introduction to microfluidic systems, we describe the advantages and challenges of the use of micro- and nanoscale confinement in optical trapping, as well as standard fabrication techniques for micro- and nanofluidic systems. From thermo-fluid dynamical viewpoints, various phenomena that accompany a laser irradiation to fluidic devices, are explained in detail. These phenomena can affect the optical trapping of target materials significantly, and are classified into two categories: one that induces the fluid flow around the target and another that directly acts on it as an external force. These classes are reviewed by shedding light on some recent cutting-edge researches for optical manipulation. Some applications using thermo-fluid dynamics in microfluidic systems for the measurement of optical forces and for the separation, measurement, and detection of target materials are also introduced

Quantification of patellar tendon reflex using portable mechanomyography and electromyography devices

Deep tendon reflexes are one of the main components of the clinical nervous system examinations. These assessments are inexpensive and quick. However, evaluation can be subjective and qualitative. This study aimed to objectively evaluate hyperreflexia of the patellar tendon reflex using portable mechanomyography (MMG) and electromyography (EMG) devices. This study included 10 preoperative patients (20 legs) who had a pathology that could cause bilateral patellar tendon hyperreflexia and 12 healthy volunteers (24 legs) with no prior history of neurological disorders. We attached MMG/EMG sensors onto the quadriceps and tapped the patellar tendon with maximal and constant force. Our results showed a significantly high amplitude of the root mean square (RMS) and low frequency of the mean power frequency (MPF) in the rectus femoris, vastus medialis, and vastus lateralis muscles in both EMG and MMG with both maximal and constant force. Especially in the patients with cervical and thoracic myelopathy, the receiver operating characteristic (ROC) curve for diagnosing hyperreflexia of the patellar tendon showed a moderate to very high area under the curve for all EMG-RMS, EMG-MPF, MMG-RMS, and MMG-MPF values. The use of EMG and MMG for objectively quantifying the patellar tendon reflex is simple and desirable for future clinical applications and could help diagnose neurological disorders

Characterization of the chromosomal inversion associated with the Koa mutation in the mouse revealed the cause of skeletal abnormalities

<p>Abstract</p> <p>Background</p> <p>Koala (<it>Koa</it>) is a dominant mutation in mice causing bushy muzzle and pinna, and is associated with a chromosomal inversion on the distal half of chromosome 15. To identify the gene responsible for the <it>Koa </it>phenotypes, we investigated phenotypes of <it>Koa </it>homozygous mice and determined the breakpoints of the inversion with a genetic method using recombination between two different chromosomal inversions.</p> <p>Results</p> <p>Skeletal preparation of <it>Koa </it>homozygotes showed marked deformity of the ribs and a wider skull with extended zygomatic arches, in addition to a general reduction in the lengths of long bones. They also had open eyelids at birth caused by a defect in the extension of eyelid anlagen during the embryonic stages. The proximal and distal breakpoints of the <it>Koa </it>inversion were determined to be 0.8-Mb distal to the <it>Trsps1 </it>gene and to 0.1-Mb distal to the <it>Hoxc4 </it>gene, respectively, as previously reported. The phenotypes of mice with the recombinant inverted chromosomes revealed the localization of the gene responsible the <it>Koa </it>phenotype in the vicinity of the proximal recombinant breakpoint. Expression of the <it>Trsps1 </it>gene in this region was significantly reduced in the <it>Koa </it>homozygous and heterozygous embryos.</p> <p>Conclusion</p> <p>While no gene was disrupted by the chromosomal inversion, an association between the <it>Koa </it>phenotype and the proximal recombinant breakpoint, phenotypic similarities with <it>Trps1</it>-deficient mice or human patients with <it>TRSP1 </it>mutations, and the reduced expression of the <it>Trsps1 </it>gene in <it>Koa </it>mice, indicated that the phenotypes of the <it>Koa </it>mice are caused by the altered expression of the <it>Trps1 </it>gene.</p

Short-term outcomes of mirogabalin in patients with peripheral neuropathic pain: a retrospective study

Background Mirogabalin, which is approved for the treatment of peripheral neuropathic pain in Japan, is a ligand for the α2δ subunit of voltage-gated calcium channels. Both pregabalin and mirogabalin act as nonselective ligands at the α2δ-1 and α2δ-2 subunits. Mirogabalin has a unique binding profile and long duration of action. Pregabalin has been reported to produce intolerable adverse effects in some patients. This study investigated outcomes associated with mirogabalin administration in patients with peripheral neuropathic pain who ceased treatment with pregabalin. Methods We retrospectively assessed peripheral neuropathic pain using the neuropathic pain screening questionnaire (NeP score) in 187 patients (58 men, 129 women) who were treated with mirogabalin. All patients had switched from pregabalin to mirogabalin due to lack of efficacy or adverse events. Differences in the treatment course (i.e., numeric rating scale (NRS) scores) were compared using one-way analysis of variance with Bonferroni post hoc tests. Results The mean age of the patients was 72.3 years (range, 30–94 years), and the mean duration of disease was 37 months (range, 3–252 months). After treatment with mirogabalin for 1 week, NRS scores significantly decreased compared with baseline and continued to decrease over time. After 8 weeks, NRS scores improved by ≥ 30% from baseline in 113 patients (69.3%). Twenty-four patients (12.8%) stopped mirogabalin treatment due to adverse events. Somnolence (26.7%), dizziness (12.3%), edema (5.9%), and weight gain (0.5%) were noted as adverse events of mirogabalin. Conclusions The results of this investigation indicate that mirogabalin is safe and effective for reducing peripheral neuropathic pain

Single Balloon Enteroscopy-Assisted ERCP Using Rendezvous Technique for Sharp Angulation of Roux-en-Y Limb in a Patient with Bile Duct Stones

The acute angulation of Roux-en-Y (R-Y) limb precludes endoscopic access for endoscopic retrograde cholangiopancreatography (ERCP) even using a balloon enteroscopy. Here, we describe a case of successful single balloon enteroscopy (SBE)-assisted ERCP using a rendezvous technique in a patient with sharply angulated R-Y limb in a 79-year-old woman who had bile duct stones. Method. At first, a guidewire was passed antegradely through the major papilla after the needle puncture using percutaneous transhepatic biliary drainage technique. A hydrophilic guidewire with an ERCP catheter was antegradely advanced beyond the Roux limb. After a guidewire was firmly grasped by a snare forceps, it was pulled out of the body, resulting that the enteroscope could advance to the papilla. After papillary dilation, complete removal of bile duct stones was achieved without any procedure-related complication. In conclusion, although further study is needed, SBE-assisted ERCP using a rendezvous technique may have a potential for selected patients

歯の形態形成に関与する新規遺伝子の解明

Tooth development is controlled by body plan during the fetal period, the generation of teeth from tooth germ is induced by the epithelial-mesenchymal interaction. Spatiotemporal regulation of tooth morphogenesis is supported by gene expression. Although many of the genes involved in tooth development are known, the molecular mechanism underlying tooth morphogenesis is not completely understood. For a comprehensive understanding of tooth development, the elucidation of unknown genes is necessary. In this study, to identify unknown genes involved in tooth development, we performed genome-wide analysis at each stage of tooth development and identified 17 genes with high levels of expression and large changes in expression. In addition, we performed qPCR and in situ hybridization analyses to elucidate the spatiotemporal regulation, such as the regulation that occurs around or in the entire tooth germ, enamel knots, epithelium, and mesenchyme. These results show that these characteristic genes may play important roles in each time period or region of tooth development, and the elucidation of the functions of these genes will lead to an integrated understanding of the process of tooth development.博士（医学）・甲第790号・令和3年3月15日発行元である日本再生歯科医学会の許諾を得て登録（2021年6月29日付）ジャーナル公式サイト（日本再生歯科医学会HP内）：http://www.jarde.jp/zasshi/e/18-2-1.htm

Optimization of quantum noise in space gravitational-wave antenna DECIGO with optical-spring quantum locking considering mixture of vacuum fluctuations in homodyne detection

Quantum locking using optical spring and homodyne detection has been devised to reduce quantum noise that limits the sensitivity of DECIGO, a space-based gravitational wave antenna in the frequency band around 0.1 Hz for detection of primordial gravitational waves. The reduction in the upper limit of energy density ${\Omega}_{\mathrm{GW}}$ from $2{\times}10^{-15}$ to $1{\times}10^{-16}$, as inferred from recent observations, necessitates improved sensitivity in DECIGO to meet its primary science goals. To accurately evaluate the effectiveness of this method, this paper considers a detection mechanism that takes into account the influence of vacuum fluctuations on homodyne detection. In addition, an advanced signal processing method is devised to efficiently utilize signals from each photodetector, and design parameters for this configuration are optimized for the quantum noise. Our results show that this method is effective in reducing quantum noise, despite the detrimental impact of vacuum fluctuations on its sensitivity.Comment: 12 pages, 5 figure