Thermoelastic wave generation and its longitudinal wave.

Laser ultrasonics is a noncontact measurement method that uses a laser-induced elastic wave source in combination with an optical surface displacement-tracking system. This study compared the performances of two optical interferometers with different characteristics when applied to measurement of pulsed thermoelastic waves. The surface displacement-tracking system was designed to measure the center of the microscopic view. A pulsed laser beam irradiated a black ink layer to generate the thermoelastic waves. The out-of-plane displacement on the axially opposite side was then measured using either a Michelson interferometer or a Sagnac interferometer. The objective lens of the system was of a type commonly used in biological observations. The Michelson interferometer estimated a maximum displacement of 0.43 nm and a maximum sound pressure of 24.7 kPa. The signal-to-noise ratios from 16 averages were 14.9 dB (Michelson interferometer) and 19.2 dB (Sagnac interferometer). Furthermore, this paper compares the performance of the numerically estimated Sagnac interferometer outputs calculated from the measured Michelson interferometer outputs with the experimentally obtained Sagnac interferometer outputs. The numerically estimated Sagnac interferometer's output was shown to be identical to the experimentally acquired output. The Michelson interferometer requires a higher average operating frequency (i.e., it needs a longer data acquisition time), although this interferometer does offer superior displacement output linearity. This property enables calculation of the sound pressure from the displacement amplitude. These findings indicated that combination of the measurement points of the Sagnac interferometer with those of the sparsely distributed Michelson interferometer reduced the measurement time when compared with a single use of the Michelson interferometer while also maintaining the data acquisition quality.

Comparative analysis of ventricular stiffness across species.

Investigating ventricular diastolic properties is crucial for understanding the physiological cardiac functions in organisms and unraveling the pathological mechanisms of cardiovascular disorders. Ventricular stiffness, a fundamental parameter that defines ventricular diastolic functions in chordates, is typically analyzed using the end-diastolic pressure-volume relationship (EDPVR). However, comparing ventricular stiffness accurately across chambers of varying maximum volume capacities has been a long-standing challenge. As one of the solutions to this problem, we propose calculating a relative ventricular stiffness index by applying an exponential approximation formula to the EDPVR plot data of the relationship between ventricular pressure and values of normalized ventricular volume by the ventricular weight. This article reviews the potential, utility, and limitations of using normalized EDPVR analysis in recent studies. Herein, we measured and ranked ventricular stiffness in differently sized and shaped chambers using ex vivo ventricular pressure-volume analysis data from four animals: Wistar rats, red-eared slider turtles, masu salmon, and cherry salmon. Furthermore, we have discussed the mechanical effects of intracellular and extracellular viscoelastic components, Titin (Connectin) filaments, collagens, physiological sarcomere length, and other factors that govern ventricular stiffness. Our review provides insights into the comparison of ventricular stiffness in different-sized ventricles between heterologous and homologous species, including non-model organisms.

Remimazolam-based total intravenous anesthesia in a patient with a confirmed diagnosis of malignant hyperthermia: a case report.

BACKGROUND: Malignant hyperthermia (MH) is a rare, life-threatening disorder of calcium homeostasis in skeletal muscle cells that is triggered by volatile anesthetics and succinylcholine, leading to a hypermetabolic reaction. The pathogenic ryanodine receptor 1 (RYR1) gene variant is critical. Patients susceptible to MH should avoid triggering agents, and total intravenous anesthesia (TIVA) is preferred. Remimazolam is safe in patients with suspected MH. CASE PRESENTATION: We present the first case of remimazolam treatment in a genetically confirmed patient with MH without MH development. A 72-year-old man with a family history of MH underwent remimazolam-based TIVA. After informed consent was obtained, a muscle biopsy and genetic testing were performed. Intraoperatively and postoperatively, the patient exhibited no signs of MH. An enhanced function of the RYR1 channel into releasing calcium was indicated, and the genetic testing revealed a pathogenic variant of RYR1. CONCLUSIONS: Remimazolam-based TIVA is safe in patients confirming the diagnosis of MH.

A case of autoimmune encephalitis in a patient with a solitary intracranial plasmacytoma.

A 65-year-old woman presented with fever and abnormal behavior. Magnetic resonance imaging showed swelling of the left medial temporal lobe and an intracranial extra-axial occipital tumor. While her neurological symptoms improved after the administration of corticosteroid therapy under the suspicion of autoimmune encephalitis, the occipital tumor unexpectedly shrank, and the diagnosis of a solitary plasmacytoma was confirmed by biopsy. Additional examinations revealed elevated anti-glutamate receptor antibodies in the cerebrospinal fluid. The patient was diagnosed with autoimmune encephalitis concurrent with an intracranial solitary plasmacytoma. Central nervous system involvement can be considered a neurological complication in patients with a solitary plasmacytoma.

Optical development in the murine eye lens of accelerated senescence-prone SAMP8 and senescence-resistant SAMR1 strains.

The eye lens is responsible for focusing objects at various distances onto the retina and its refractive power is determined by its surface curvature as well as its internal gradient refractive index (GRIN). The lens continues to grow with age resulting in changes to the shape and to the GRIN profile. The present study aims to investigate how the ageing process may influence lens optical development. Murine lenses of accelerated senescence-prone strain (SAMP8) aged from 4 to 50 weeks; senescence-resistant strain (SAMR1) aged from 5 to 52 weeks as well as AKR strain (served as control) aged from 6 to 70 weeks were measured using the X-ray interferometer at the SPring-8 synchrotron Japan within three consecutive years from 2020 to 2022. Three dimensional distributions of the lens GRIN were reconstructed using the measured data and the lens shapes were determined using image segmentation in MatLab. Variations in the parameters describing the lens shape and the GRIN profile with age were compared amongst three mouse strains. With advancing age, both the lens anterior and posterior surface flattens and the lens sagittal thickness increase in all three mouse strains (Anterior radius of curvature increase at 0.008 mm/week, 0.007 mm/week and 0.002 mm/week while posterior radius of curvature increase at 0.002 mm/week, 0.007 mm/week and 0.003 mm/week respectively in AKR, SAMP8 and SAMR1 lenses). Compared with the AKR strain, the SAMP8 samples demonstrate a higher rate of increase in the posterior curvature radius (0.007 mm/week) and the thickness (0.015 mm/week), whilst the SAMR1 samples show slower increases in the anterior curvature radius (0.002 mm/week) and its thickness (0.013 mm/week). There are similar age-related trends in GRIN shape in the radial direction (in all three types of murine lenses nr2 and nr6 increase with age while nr4 decrease with age consistently) but not in the axial direction amongst three mouse strains (nz1 of AKR lens decrease while of SAMP8 and SAMR1 increase with age; nz2 of all three models increase with age; nz3 of AKR lens increase while of SAMP8 and SAMR1 decrease with age). The ageing process can influence the speed of lens shape change and affect the GRIN profile mainly in the axial direction, contributing to an accelerated decline rate of the optical power in the senescence-prone strain (3.5 D/week compared to 2.3 D/week in the AKR control model) but a retardatory decrease in the senescence-resistant strain (2.1 D/week compared to the 2.3D/week in the AKR control model).

Nonconventional Tether Structure for Quality Factor Enhancement of Thin-Film-Piezoelectric-on-Si MEMS Resonator.

This article presents a new design of supporting tethers through the concept of force distribution. The transmitted force applied on tethers will be distributed on the new tether design area, resulting in low acoustic energy transferred to anchor boundaries and stored energy enhancement. This technique achieves an anchor quality factor of 175,000 compared to 58,000 obtained from the conventional tether design, representing a three-fold enhancement. Furthermore, the unloaded quality factor of the proposed design improved from 23,750 to 27,442, representing a 1.2-fold improvement.

Reem-Shape Phononic Crystal for Q Anchor Enhancement of Thin-Film-Piezoelectric-on-Si MEMS Resonator.

This paper proposes a reem-shaped phononic crystal for the performance enhancement of TPoS resonators. The proposed phononic crystal offers an ultra-wide acoustic band gap that prevents energy leakage through the supporting substrate upon its placement at the anchoring boundary, resulting in significant improvements in the resonator quality factor. Simulated results show reem-shape phononic crystals generate a band gap up to 175 MHz with a BG of 90% and enhance the anchor quality factor from 180,000 to 6,000,000 and the unloaded quality factor from 133,000 to 160,000, representing 33.3-fold and 1.2-fold improvements, respectively.

Effects of Ndufs4 Deletion on Hearing after Various Acoustic Exposures.

Mitochondrial dysfunction can cause cochlear dysfunction and accelerate noise-induced hearing loss (NIHL). NADH dehydrogenase (ubiquinone) Fe-S protein 4 (Ndufs4) is one of the subunits of mitochondrial complex I and has a role in the assembly and stabilization of complex I. However, the involvement of Ndufs4 in the pathogenesis of NIHL has not been reported. The aim of this study was to evaluate whether Ndufs4 deletion causes vulnerability to noise exposures. The wild-type (WT) and Ndufs4 knockout (KO) mice with C57BL/6J genetic background were used. Cochlear histology and hearing thresholds were assessed after noise exposure at 100 or 86 dB sound pressure level (SPL). Immunostaining showed the widespread expression of Ndufs4 in the cochlea. After noise exposure at 100 dB SPL, auditory brainstem response (ABR) threshold shifts at 4 kHz in Ndufs4 KO mice were significantly higher than that in WT mice. After noise exposure at 86 dB SPL, ABR threshold shifts, wave 1 amplitudes, and the number of synapses in the inner hair cells were not significantly different. RNA sequencing revealed the decreased expression of energy generation-related genes inNdufs4 KO mice. Ndufs4 deficiency accelerates permanent low-frequency threshold shifts after moderate noise exposure.

Combination of Tetragonal Crystals With LiTaO3 Thin Plate for Transverse Resonance Suppression of Surface Acoustic Wave Devices.

This article discusses combination of tetragonal crystals with LiTaO3 (LT) thin plate for complete transverse resonance suppression of surface acoustic wave (SAW) devices without k2 deterioration by manipulating the slowness shape. Besides, better lateral energy confinement is achieved as well by the use of a double bus-bar structure. First, the mechanism of slowness shape manipulation by combining tetragonal crystals is studied. By comparison, YZ-lithium tetraborate (LBO) shows better performance than 69°Y90°X quartz. Then, numerical simulations are carried out using a periodic 3-D finite method assisted by a hierarchical cascading technique (HCT), and the effectiveness of transverse mode suppression by flattening the slowness shape is revealed. Also, the possibility to realize temperature compensation (TC) is discussed owing to the unique material property of LBO. Moreover, the capability of other tetragonal crystals for slowness manipulation is compared, and LBO is the best choice among these tetragonal crystals.

Cardiac hemodynamics and ventricular stiffness of sea-run cherry salmon (Oncorhynchus masou masou) differ critically from those of landlocked masu salmon.

Ventricular diastolic mechanical properties are important determinants of cardiac function and are optimized by changes in cardiac structure and physical properties. Oncorhynchus masou masou is an anadromous migratory fish of the Salmonidae family, and several ecological studies on it have been conducted; however, the cardiac functions of the fish are not well known. Therefore, we investigated ventricular diastolic function in landlocked (masu salmon) and sea-run (cherry salmon) types at 29-30 months post fertilization. Pulsed-wave Doppler echocardiography showed that the atrioventricular inflow waveforms of cherry salmon were biphasic with early diastolic filling and atrial contraction, whereas those of masu salmon were monophasic with atrial contraction. In addition, end-diastolic pressure-volume relationship analysis revealed that the dilatability per unit myocardial mass of the ventricle in cherry salmon was significantly suppressed compared to that in masu salmon, suggesting that the ventricle of the cherry salmon was relatively stiffer (relative ventricular stiffness index; p = 0.0263). Contrastingly, the extensibility of cardiomyocytes, characterized by the expression pattern of Connectin isoforms in their ventricles, was similar in both types. Histological analysis showed that the percentage of the collagen accumulation area in the compact layer of cherry salmon increased compared with that of the masu salmon, which may contribute to ventricle stiffness. Although the heart mass of cherry salmon was about 11-fold greater than that of masu salmon, there was no difference in the morphology of the isolated cardiomyocytes, suggesting that the heart of the cherry salmon grows by cardiomyocyte proliferation, but not cell hypertrophy. The cardiac physiological function of the teleosts varies with differences in their developmental processes and life history. Our multidimensional analysis of the O. masou heart may provide a clue to the process by which the heart acquires a biphasic blood-filling pattern, i.e., a ventricular diastolic suction.

First-Order Perturbation Analysis of Nonlinear Signal Generation in Surface Acoustic Wave Resonators on LiTaO3/SiO2/Si Structure Based on Coupling-of-Modes Theory.

This article describes the first-order perturbation analysis of nonlinear responses in surface acoustic wave (SAW) resonators on the LiTaO3/SiO2/Si structure, where bulk wave radiation is negligible near the main resonance while the longitudinal resonances are not. The coupling-of-modes (COMs) theory is employed as the platform for both the linear and nonlinear response analyses. Stress and dielectric flux are assumed to be generated by nonlinear mixture of linear strain and electric fields proportional to the SAW displacement and applied voltage, respectively, and they are newly introduced to the extended COM equations as excitation sources. The simulated third harmonic (H3) responses agree well with the experimental ones including that caused by longitudinal resonances, and effectiveness of the present method is demonstrated. Furthermore, this theory is applied to the infinitely long interdigital transducer (IDT) to highlight the impact of longitudinal resonances.

Postnatal expression of cell cycle promoter Fam64a causes heart dysfunction by inhibiting cardiomyocyte differentiation through repression of Klf15.

Introduction of fetal cell cycle genes into damaged adult hearts has emerged as a promising strategy for stimulating proliferation and regeneration of postmitotic adult cardiomyocytes. We have recently identified Fam64a as a fetal-specific cell cycle promoter in cardiomyocytes. Here, we analyzed transgenic mice maintaining cardiomyocyte-specific postnatal expression of Fam64a when endogenous expression was abolished. Despite an enhancement of cardiomyocyte proliferation, these mice showed impaired cardiomyocyte differentiation during postnatal development, resulting in cardiac dysfunction in later life. Mechanistically, Fam64a inhibited cardiomyocyte differentiation by repressing Klf15, leading to the accumulation of undifferentiated cardiomyocytes. In contrast, introduction of Fam64a in differentiated adult wildtype hearts improved functional recovery upon injury with augmented cell cycle and no dedifferentiation in cardiomyocytes. These data demonstrate that Fam64a inhibits cardiomyocyte differentiation during early development, but does not induce de-differentiation in once differentiated cardiomyocytes, illustrating a promising potential of Fam64a as a cell cycle promoter to attain heart regeneration.

Figure of Merit Enhancement of Laterally Vibrating RF-MEMS Resonators via Energy-Preserving Addendum Frame.

This paper examines a new technique to improve the figure of merit of laterally vibrating RF-MEMS resonators through an energy-preserving suspended addendum frame structure using finite element analysis. The proposed suspended addendum frame on the sides of the resonant plate helps as a mechanical vibration isolator from the supporting substrate. This enables the resonator to have a low acoustic energy loss, resulting in a higher quality factor. The simulated attenuation characteristics of the suspended addendum frame are up to an order of magnitude larger than those achieved with the conventional structure. Even though the deployed technique does not have a significant impact on increasing the effective electromechanical coupling coefficient, due to a gigantic improvement in the unloaded quality factor, from 4106 to 51,136, the resonator with the suspended frame achieved an 11-folds improvement in the figure of merit compared to that of the conventional resonator. Moreover, the insertion loss was improved from 5 dB down to a value as low as 0.7 dB. Furthermore, a method of suppressing spurious mode is demonstrated to remove the one incurred by the reflected waves due to the proposed energy-preserving structure.

Double Busbar Structure for Transverse Energy Leakage and Resonance Suppression in Surface Acoustic Wave Resonators Using 42°YX-Lithium Tantalate Thin Plate.

This article describes a new transverse edge structure with double busbar for surface acoustic wave (SAW) devices employing a 42°YX-lithium tantalate thin plate such as incredible high-performance (I.H.P.) SAW. This design offers good energy confinement and scattering loss suppression for a wide frequency range. First, preexisting transverse edge designs are reviewed, and their difficulties are pointed out using the dispersion relation for lateral SAW propagation. Then, numerical simulations are performed using the periodic 3-D finite-element method (FEM) powered by the hierarchical cascading technique, and effectiveness of the proposed structure is revealed. In addition, we also provide a possible solution to expand the frequency range giving well energy confinement and demonstrate effectiveness of manipulating the SAW slowness curve shape for transverse mode suppression.

[Development of autoimmune hemolytic anemia after BNT162b2 mRNA COVID-19 vaccination].

A 75-year-old woman with a history of postoperative chemotherapy for lung adenocarcinoma and a history of Helicobacter pylori eradication for idiopathic thrombocytopenic purpura (ITP) was admitted to the department of hematology and oncology for the treatment of anemia 2 weeks after BNT162b2 mRNA COVID-19 vaccination. Her blood examination revealed direct and indirect Coombs test-positive hemolytic anemia and elevation of serum LDH and indirect bilirubin levels. No obvious trigger other than BNT162b2 mRNA COVID-19 vaccination was found. She was diagnosed with autoimmune hemolytic anemia (AIHA), and oral prednisolone therapy was administered. The anemia improved soon after the administration of prednisolone. Although vaccination is considered to be very important for suppressing the spread of COVID-19, there have been reports of increasing risk of ITP development and deterioration caused by BNT162b2 mRNA COVID-19 vaccination. Because the number of vaccinated people is increasing rapidly, hematologists must be vigilant to the development of AIHA after BNT162b2 mRNA COVID-19 vaccination although case reports of this phenomenon have been very rare thus far.

Cochlear Synaptic Degeneration and Regeneration After Noise: Effects of Age and Neuronal Subgroup.

In CBA/CaJ mice, confocal analysis has shown that acoustic overexposure can immediately destroy synapses between auditory-nerve fibers (ANFs) and their peripheral targets, the inner hair cells (IHCs), and that years later, a corresponding number of ANF cell bodies degenerate. In guinea pig, post-exposure disappearance of pre-synaptic ribbons can be equally dramatic, however, post-exposure recovery to near-baseline counts has been reported. Since confocal counts are confounded by thresholding issues, the fall and rise of synaptic ribbon counts could represent "regeneration," i.e., terminal retraction, re-extension and synaptogenesis, or "recovery," i.e., down- and subsequent up-regulation of synaptic markers. To clarify, we counted pre-synaptic ribbons, assessed their juxtaposition with post-synaptic receptors, measured the extension of ANF terminals, and quantified the spatial organization and size gradients of these synaptic elements around the hair cell. Present results in guinea pigs exposed as adults (14 months), along with prior results in juveniles (1 month), suggest there is post-exposure neural regeneration in the guinea pig, but not the CBA/CaJ mouse, and that this regenerative capacity extends into adulthood. The results also show, for the first time, that the acute synaptic loss is concentrated on the modiolar side of IHCs, consistent with a selective loss of the high-threshold ANFs with low spontaneous rates. The morphological similarities between the post-exposure neurite extension and synaptogenesis, seen spontaneously in the guinea pig, and in CBA/CaJ only with forced overexpression of neurotrophins, suggest that the key difference may be in the degree of sustained or injury-induced expression of these signaling molecules in the cochlea.

Characteristics of aspiration pneumonia patients in acute care hospitals: A multicenter, retrospective survey in Northern Japan.

BACKGROUND: Pneumonia is a common cause of illness and death of the elderly in Japan. Its prevalence is escalating globally with the aging of population. To describe the latest trends in pneumonia hospitalizations, especially aspiration pneumonia (AP) cases, we assessed the clinical records of pneumonia patients admitted to core acute care hospitals in Miyagi prefecture, Japan. METHODS: A retrospective multi-institutional joint research was conducted for hospitalized pneumonia patients aged ≥20 years from January 2019 to December 2019. Clinical data of patients were collected from the medical records of eight acute care hospitals. RESULTS: Out of the 1,800 patients included in this study, 79% of the hospitalized pneumonia patients were aged above 70 years. The most common age group was in the 80s. The ratio of AP to total pneumonia cases increased with age, and 692 out of 1,800 patients had AP. In univariate analysis, these patients had significantly older ages, lower body mass index (BMI), a lower ratio of normal diet intake and homestay before hospitalization, along with more AP recurrences and comorbidities. During hospitalization, AP patients had extended fasting periods, more swallowing assessments and interventions, longer hospitalization, and higher in-hospital mortality rate than non-AP patients. A total of 7% and 2% AP patients underwent video endoscopy and video fluorography respectively. In multivariate analysis, lower BMI, lower C-reactive protein, a lower ratio of homestay before hospitalization, a higher complication rate of cerebrovascular disease, dementia, and neuromuscular disease were noted as a characteristic of AP patients. Swallowing interventions were performed for 51% of the AP patients who had been hospitalized for more than two weeks. In univariate analysis, swallowing intervention improved in-hospital mortality. Lower AP recurrence before hospitalization and a lower ratio of homestay before hospitalization were indicated as characteristics of AP patients of the swallowing intervention group from multivariate analysis. Change in dietary pattern from normal to modified diet was observed more frequently in the swallowing intervention group. CONCLUSION: AP accounts for 38.4% of all pneumonia cases in acute care hospitals in Northern Japan. The use of swallowing evaluations and interventions, which may reduce the risk of dysphagia and may associate with lowering mortality in AP patients, is still not widespread.

Synaptic migration and reorganization after noise exposure suggests regeneration in a mature mammalian cochlea.

Overexposure to intense noise can destroy the synapses between auditory nerve fibers and their hair cell targets without destroying the hair cells themselves. In adult mice, this synaptopathy is immediate and largely irreversible, whereas, in guinea pigs, counts of immunostained synaptic puncta can recover with increasing post-exposure survival. Here, we asked whether this recovery simply reflects changes in synaptic immunostaining, or whether there is actual retraction and extension of neurites and/or synaptogenesis. Analysis of the numbers, sizes and spatial distribution of pre- and post-synaptic markers on cochlear inner hair cells, in guinea pigs surviving from 1 day to 6 months after a synaptopathic exposure, shows dramatic synaptic re-organization during the recovery period in which synapse counts recover from 16 to 91% of normal in the most affected regions. Synaptic puncta move all over the hair cell membrane during recovery, translocating far from their normal positions at the basolateral pole, and auditory-nerve terminals extend towards the hair cell's apical end to re-establish contact with them. These observations provide stronger evidence for spontaneous neural regeneration in a mature mammalian cochlea than can be inferred from synaptic counts alone.

Effects of intravenous injection of indocyanine green on the oxygen reserve index (ORi™).

PURPOSE: The oxygen reserve index (ORi™) is a parameter used for the noninvasive evaluation of arterial partial pressure of oxygen (PaO2), specifically in the 100-200 mmHg range. We aimed to report on the impact of indocyanine green (ICG) on the ORi™. METHODS: In this study, we retrospectively examined patients who underwent neurosurgery between April and July 2019 and assessed the impact of ICG on ORi™. We excluded patients who did not use ICG or who were not examined for ORi™. The dose and timing of ICG administration were determined by a neurosurgeon. The changes in ORi™ were measured for up to 30 min. RESULTS: We analyzed ten patients and found that the ORi™ increased to 1.00 in all of them. The median time for ORi ™ to rise to 1.00 after ICG administration was 2 min (range 1-4). After rising to 1.00, ORi ™ decreased and took 27 min to return to the pre-dose value. CONCLUSION: It is important to consider the initial rapid increase and subsequent slow decrease in ORi™ when using ICG during surgery.