Search

The Kerr Parametric Oscillator (KPO) is a nonlinear resonator system that is often described as a synthetic two-level system. In the presence of noise, the system switches between two states via a fluctuating trajectory in phase space, instead of following a straight path. The presence of such fluctuating trajectories makes it hard to establish a precise count or even a useful definition, of the "lifetime" of the state. Addressing this issue, we compare several rate counting methods that allow to estimate a lifetime for the levels. In particular, we establish that a peak in the Allan variance of fluctuations can also be used to determine the levels' lifetime. Our work provides a basis for characterizing KPO networks for simulated annealing where an accurate determination of the state lifetime is of fundamental importance. [ABSTRACT FROM AUTHOR]

Encapsulated bulk mode microresonators in the megahertz range are used in commercial timekeeping and sensing applications, but their performance is limited by the current state of the art of readout methods. We demonstrate a readout using dispersive coupling between a high-Q encapsulated bulk mode micromechanical resonator and a lumped element microwave resonator that is implemented with commercially available components and standard printed circuit board fabrication methods and operates at room temperature and pressure. A frequency domain measurement of the microwave readout system yields a displacement resolution of 522 fm / Hz , which demonstrates an improvement over the state of the art of displacement measurement in bulk-mode encapsulated microresonators. This approach can readily be implemented in cryogenic measurements, allowing for future work characterizing the thermomechanical noise of encapsulated bulk mode resonators at cryogenic temperatures. [ABSTRACT FROM AUTHOR]

Clamping loss in micromechanical resonators can strongly depend on the boundary conditions far away from the actual vibrating structure because the acoustic wavelength greatly exceeds the device dimensions. We demonstrate a scheme for post-fabrication tuning of the clamping loss in flexural-mode and bulk-mode resonators by modifying the boundary conditions of the chip with the frame. The measured quality factor increases by more than an order-of-magnitude for the microcantilevers and more than a factor of three for the bulk-mode resonators when frame contact is minimized via suspension of the chip by wirebonds. We propose a two-degree-of-freedom fluctuation-dissipation model to describe the thermomechanical noise and forced response in the presence of this tunable anchor damping. By studying the thermomechanical displacement spectrum with tunable clamping loss, we show that variable clamping loss tunes the mechanical quality factor, modifying both the resonator transfer function and thermomechanical noise force. We delineate the dependence of the tunable clamping loss mechanism on microcantilever beam length and ambient temperature from 300 K down to 40 K, and observe potential temperature dependence to clamping loss with reducing temperature. [2021-0141] [ABSTRACT FROM AUTHOR]

Pedicle screw instrumentation is a fundamental technique in lumbar spine surgery. However, several complications could occur when placing a pedicle screw, the most serious being damage to the neural structures. We developed an attachable magnetic nerve stimulating probe used for triggered electromyography (t-EMG) to avoid these. This study aimed to investigate the efficacy of this probe for intraoperative neuromonitoring (ION) during lumbar pedicle screw placement in a porcine model. Forty pedicle screws were inserted bilaterally into the pedicles of the fourth and fifth lumbar vertebrae of five pigs; 20 were inserted typically into the pedicle without nerve damage (Group A), and the other 20 were inserted through the broken medial wall of the pedicle to permit contact with the neural structures (Group B). We measured the triggered threshold for pedicle screw placement through the conventional nerve probe and our newly developed magnetic probe. There was no significant difference in the triggered threshold between the two instruments (p = 0.828). Our newly developed magnetic stimulating probe can be attached to a screwdriver, thus preventing real-time screw malpositioning and making it practical and equally safe. This probe could become indispensable in revision spine surgeries with severe adhesions or endoscopic spine surgeries. [ABSTRACT FROM AUTHOR]

We present a study on the quantification of energy dissipation of Micro-Electro-Mechanical System (MEMS) resonators. Toroidal Ring Gyroscope (TRG) was used as a platform to conduct the study. The main energy dissipation mechanisms in TRG include viscous air damping, Thermo-Elastic Damping (TED), anchor loss, and surface loss. During our experimental study, these energy dissipation mechanisms were minimized and controlled by venting the encapsulation and actively pumping down to high vacuum, cooling the temperature down to around 123 K, adjusting modal balance by electrostatic tuning, and pre-baking the device at high temperature (425 °C), respectively. At room temperature, the quality factor related to viscous air damping was measured to be 625,000, TED to be 170,000, and anchor loss to be 1,350,000. Finite Element Analysis (FEA) was conducted to support these findings. Relation between the anchor loss and electrostatic tuning was also explored. The effects of moisture-related surface loss have also been demonstrated by monitoring characteristics over a 2-year period of time. High temperature bake-out was proven to be effective in removing the moisture and reducing the surface loss. This paper combines topics that are scattered in literature on identification of energy dissipation mechanisms in kilohertz-range silicon MEMS resonators and presents the topic as a single methodology illustrating how the contribution of each energy dissipation mechanism can be quantified independently. To the best of our knowledge, this study is the first to experimentally quantify all major energy dissipation mechanisms in a kilohertz-range silicon MEMS resonator. [2020-0294] [ABSTRACT FROM AUTHOR]

We present a Lamé mode resonator whose limiting damping mechanism depends on its anchor geometry. The device is anchor-limited when the anchors are stiffer and is Akhiezer-limited with more compliant anchors. This result is determined by observing the temperature dependence of the quality factor (Q) for devices with different lateral dimensions and different anchor designs. The total measured Q increases by an order of magnitude with the more compliant anchors and reaches a room temperature fxQ product of $\boldsymbol {2.2\times 10^{13}}$. We studied the relationship between the device design and the anchor design and the measured Q(T) results to identify the contributions from different dissipation mechanisms. This investigation provides insight into how anchor design affects anchor damping. [2020-0195] [ABSTRACT FROM AUTHOR]

In this work we present measurements of drive-induced negative nonlinear dissipation present in doubly clamped microbeams fabricated in a hermetically sealed package. We characterize the amplitude-frequency nonlinearity and nonlinear dissipation present in this system under direct drive. The negative nature of the nonlinear dissipation is observed when measuring either the directly- or parametrically-actuated response. By comparing to the free ringdown response, we confirm that the nonlinear dissipation is induced by driving the resonator. Drive-induced nonlinear damping is an important consideration for resonant sensors and oscillators operated at large amplitudes. [2020-0140] [ABSTRACT FROM AUTHOR]

We derive the displacement noise spectrum of a parametrically pumped resonator below the onset for self-excited oscillations. We extend the fluctuation-dissipation response of a thermomechanical-noise-driven resonator to the case of degenerate parametric pumping as a function of pump magnitude and frequency while properly accounting for the quadrature-dependence of the parametric thermal noise squeezing. We use measurements with a microelectromechanical cantilever to corroborate our model. [ABSTRACT FROM AUTHOR]

We demonstrate two novel dual-mode ovenized MEMS resonators, each with an in-chip device layer micro-oven that utilizes less than 30mW for resonator temperature control over variations in external temperature from −40°C to +60°C. The device layer micro-oven enables correction for ambient temperature variations and achieves a 1-week frequency stability for the output mode over temperature near 1.5 ppb for the Lamé-mode resonator. The devices were built in the Epi-Seal fabrication process and take advantage of the exceptional long-term stability of MEMS resonators built in that process. These results exceed all prior reports for frequency stability over time and temperature for MEMS resonators and have the potential to impact the development of miniature, low-power time references. [2019-0054] [ABSTRACT FROM AUTHOR]

The therapeutic potential of tonsil-derived mesenchymal stem cells (TMSCs) has been proved in several in vitro and in vivo models based on their antioxidative capacity. Oxidative stress is involved in the formation of vocal fold scars and the aging of vocal folds. However, few studies have examined the direct correlation between oxidative damage and reconstitution of extracellular matrix (ECM) in the vocal fold fibrosis. We, therefore, sought to investigate the impact of oxidative stress on cell survival and ECM production of human vocal fibroblasts (hVFFs) and the protective effects elicited by TMSCs against oxidative damages in hVFFs. hVFFs were exposed to different concentrations of tert-butyl hydroperoxide in the presence or absence of TMSCs. Cell viability and reactive oxygen species (ROS) production were assessed to examine the progression of oxidative stress in vitro. In addition, expression patterns of ECM-associated factors including various collagens were examined by real-time PCR and immunocytochemical analysis. We found that both cell viability and proliferation capacity of hVFFs were decreased following the exposure to tBHP in a dose-dependent manner. Furthermore, tBHP treatment induced the generation of ROS and reactive aldehydes, while it decreased endogenous activity of antioxidant enzymes in hVFF. Importantly, TMSCs could rescue these oxidative stress-associated damages of hVFFs. TMSCs also downregulated tBHP-mediated production of proinflammatory cytokines in hVFFs. In addition, coculture with TMSC could restore the endogenous matrix metalloproteinase (MMP) activity of hVFFs upon tBHP treatment and, in turn, reduce the oxidative stress-induced ECM accumulation in hVFFs. We have, therefore, shown that the changes in hVFF proliferative capacity and ECM gene expression induced by oxidative stress are consistent with in vivo phenotypes observed in aging vocal folds and vocal fold scarring and that TMSCs may function to reduce oxidative stress in aging vocal folds. [ABSTRACT FROM AUTHOR]

Sensitive capacitive transduction of micromechanical resonators can contribute significant electrical dissipation, which degrades the quality factor of the eigenmodes. We theoretically and experimentally demonstrate a scheme for isolating the electrical damping of a mechanical resonator due to Ohmic dissipation in the readout amplifier. The quality factor suppression arising from the amplifier is strongly dependent on the amplifier feedback resistance and parasitic capacitance. By studying the thermomechanical displacement noise spectrum of a doubly clamped micromechanical beam, we confirm that electrical dissipation tunes the actual, not effective, quality factor. Electrical dissipation is an important consideration in the design of sensitive capacitive displacement transducers, which are a key component in resonant sensors and oscillators. [ABSTRACT FROM AUTHOR]

The thermomechanical motion imposes the fundamental noise limit in room-temperature resonant sensors and oscillators. Due to the inherently low sensitivity of capacitive transduction in microelectromechanical (MEM) resonators, its effects are often masked by noise in the subsequent amplifier and measurement stages. In this work, we demonstrate a capacitive transduction scheme for measuring kHz-MHz frequency MEM resonators across 1 $\mu \text{m}$ capacitive gaps with 99.8% thermomechanical-noise-limited resolution. We delineate the transimpedance gain and noise of our custom off-chip differential transimpedance amplifier setup. The thermomechanical noise spectrum can provide estimates of the resonant frequency, quality factor, and electromechanical transduction factor comparable to the commonly used driven response, without the downsides of capacitive feedthrough or nonlinearity. [2019-0115] [ABSTRACT FROM AUTHOR]

This work demonstrates that thin slots strategically placed in MEMS ring resonators are able to enhance the quality factor (Q) of the device operated in a wineglass mode in the isothermal region. The devices are optimized using COMSOL for an increased Q through increased slot size, using the Zener curve as a comparative baseline. These parts are fabricated and encapsulated in an ultra-clean environment, and tested in various temperature and pressure conditions to directly measure changes in anchor, gas, and thermoelastic dissipation across temperature. [2020-0156] [ABSTRACT FROM AUTHOR]

Abstract: Fillers are products that fill the space in soft tissues of the human body and actively used in the various medical fields. Unfortunately, most of the cost‐effective commercially available fillers are synthetic and have limitations in terms of their biocompatibility. Here, we evaluated the possible application of decellularized xenogenic cartilage as a long‐lasting material for soft tissue augmentation and compared it with two commercially available fillers Artesense (polymethylmethacrylate microspheres) and Radiesse (calcium hydroxyapatite [CaHa]). To do so, porcine auricular cartilage was harvested, followed by freezing and grinding of the tissue into flakes. Then, we used 1% Triton X‐100 to decellularize the flakes. We then, respectively, injected 0.1 cc of each material (decellularized xenogenic cartilage, Radiesse, and Artesense) into the subcutaneous layer at three different sites per subject in 12 Sprague‐Dawley rats, and evaluated the inflammatory cell infiltration and foreign body reactions of each. Our data indicate that the infiltration of giant cells in the injection area was significantly lower in the decellularized xenogenic cartilage injection group than that in the Radiesse and Artesense injection groups. Further, we observed some neutrophil infiltration in the xenogenic cartilage and Artesense injection groups at 1 month, but these levels were much lower at 3 months (comparable to the Radiesse injection group). Thus, decellularized xenogenic cartilage may have a distinct advantage in terms of biocompatibility compared with other commercial injectable long‐lasting fillers, making it one of the most feasible, natural, and cost effective materials in the market. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2708–2715, 2018. [ABSTRACT FROM AUTHOR]

The conversion and manipulation of light via luminescent down-shifting (LDS) show promise in numerous applications. An elegant combination of lanthanide-doped polymer-derived ceramics incorporated with versatile nanopatterns is demonstrated using direct nanoimprint techniques. The prompt formation of nanoscale photonic structures enhances the fluorescence emission from the LDS while retaining the material's optical transparency. The functionality of this material is further expanded to accommodate surface energy modulation by nanopatterns. The practical applicability of this platform in photovoltaic devices is evaluated, showing distinctively enhanced efficiency and lifetime mainly attributed to the nanopattern assisted strong LDS property. Moreover, to efficiently combine two lanthanide emissions, so called a 'double imprint' approach is devised by superpositioning two LDS nanopatterned arrays. Combined with the multi-functionality such as prominent LDS characteristics, color tunability, and surface energy modulation, the developed LDS platform offers promise for esthetic building-integrated photovoltaics. [ABSTRACT FROM AUTHOR]

An optically controlled energy‐harvesting smart window that incorporates a semitransparent solar cell with a photo­sensitive liquid crystal (LC) layer is demonstrated. The LC layer can switch between a transparent (day mode) and an opaque (night mode) state depending upon the incident solar radiation. Combined with a photovoltaic cell, this window provides a template for future smart window systems. [ABSTRACT FROM AUTHOR]

In this paper, we demonstrate a dual frequency oven-controlled MEMS resonator that can be designed to have an output frequency of 1.27 Mhz or 13 Mhz depending on the crystal orientation of the device. Both modes operate based on closed-loop thermal compensation that can offer PPB (parts-per-billion) level temperature stability over a wide temperature range using low power and exhibit strong shock robustness. As the device is rotated 45- degrees with respect to the $< 100>$ plane of the wafer, the two modes used in oven control exhibit a unique temperature coefficient of frequency (tcF) reversal that allows selection of the output frequency for timing reference applications. The stiffer inplane mode has better temperature stability and shock resistance whereas the plate-bending mode offers ease of drive. Both devices retain stability performance after multiple 12,000g level shocks. [2020-0143] [ABSTRACT FROM AUTHOR]

In the above article , Reference should have read as follows: [ABSTRACT FROM AUTHOR]

Mesenchymal stromal cells (MSCs) from various sources exhibit different potential for stemness and therapeutic abilities. Recently, we reported a unique MSCs from human palatine tonsil (TMSCs) and their superior proliferation capacity compared to MSCs from other sources. However, unique characteristics of each MSC are not yet precisely elucidated. We investigated the role of stanniocalcin-1 (STC1), an anti-oxidative hormone, in the functions of TMSCs. We found that STC1 was highly expressed in TMSC compared with MSCs from bone marrow or adipose tissue. The proliferation, senescence and differentiation of TMSCs were assessed after the inhibition of STC1 expression. STC1 inhibition resulted in a significant decrease in the proliferation of TMSCs and did not affect the differentiation potential. To reveal the anti-oxidative ability of STC1 in TMSCs themselves or against other cell types, the generation of mitochondrial reactive oxygen species (ROS) in TMSC or ROS-mediated production of interleukin (IL)-1β from macrophage-like cells were detected. Interestingly, the basal level of ROS generation in TMSCs was significantly elevated after STC1 inhibition. Moreover, down-regulation of STC1 impaired the inhibitory effect of TMSCs on IL-1β production in macrophages. Taken together, these findings indicate that STC1 is highly expressed in TMSCs and plays a critical role in proliferating and ROS-regulatory abilities. [ABSTRACT FROM AUTHOR]

An optically controlled energy‐harvesting smart window that incorporates a semitransparent solar cell with a photosensitive liquid crystal layer is reported by Stephen M. Morris, Richard H. Friend, Doo‐Hyun Ko, and co‐workers in article number 1401347. When the sun shines on the window, the pitch of the liquid crystal layer is modulated and the window becomes transparent (day mode). In the dark, the window is opaque (night mode). [ABSTRACT FROM AUTHOR]

Background: Metastatic lymph nodes are occasionally found in suprasternal lymph nodes in patients with papillary thyroid cancer (PTC). However, limited studies have examined these lymph nodes thus far. Therefore, we investigated the frequency and risk factors of suprasternal lymph node metastasis in patients with PTC and lateral cervical lymph node metastasis., Methods: A total of 85 patients with cN1b PTC underwent total thyroidectomy, central neck dissection, and ipsilateral selective neck dissection including suprasternal lymph node dissection. We analyzed the correlation between suprasternal lymph node metastasis and sex, age, tumor characteristics, and cervical lymph node metastasis status., Results: Eleven (12.9%) patients had pathological suprasternal lymph node metastasis. Suprasternal lymph node metastasis was associated with tumors located in the inferior pole of the thyroid gland and level IV lymph node metastasis (P=0.005 and 0.014, respectively). Receiver operating characteristic curve analysis indicated that two or more level IV metastatic lymph nodes had the best predictive value for suprasternal lymph node metastasis (P<0.001)., Conclusions: In patients with cN1b PTC, especially those with tumors in the inferior pole of the thyroid gland or level IV lymph node metastasis, greater attention should be paid to the suprasternal lymph nodes and suprasternal lymph node dissection should be routinely included as part of selective neck dissection., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at http://dx.doi.org/10.21037/gs-20-368). The authors have no conflicts of interest to declare., (2021 Gland Surgery. All rights reserved.)

Objectives: Facial nerve monitoring (FNM) can be used to identify the facial nerve, to obtain information regarding its course, and to evaluate its status during parotidectomy. However, there has been disagreement regarding the efficacy of FNM in reducing the incidence of facial nerve palsy during parotid surgery. Therefore, instead of using electromyography (EMG) to identify the location and state of the facial nerve, we applied an intraoperative neuromonitoring (IONM) system using a surface pressure sensor to detect facial muscle twitching. The objective of this study was to investigate the feasibility of using the IONM system with a surface pressure sensor to detect facial muscle twitching during parotidectomy., Methods: We evaluated the stimulus thresholds for the detection of muscle twitching in the orbicularis oris and orbicularis oculi, as well as the amplitude and latency of EMG and the surface pressure sensor in 13 facial nerves of seven rabbits, using the same stimulus intensity., Results: The surface pressure sensor detected muscle twitching in the orbicularis oris and orbicularis oculi in response to a stimulation of 0.1 mA in all 13 facial nerves. The stimulus threshold did not differ between the surface pressure sensor and EMG., Conclusion: The application of IONM using a surface pressure sensor during parotidectomy is noninvasive, reliable, and feasible. Therefore, the IONM system with a surface pressure sensor to measure facial muscle twitching may be an alternative to EMG for verifying the status of the facial nerve.

Salivary gland dysfunction is a common symptom that occurs after menopause. This study was performed to investigate the mechanism of salivary gland dysfunction to confirm the relationship between ferroptosis and salivary gland dysfunction by ovariectomy. Forty-eight female rats were randomly divided into four groups (12 rats in each group). Histology, real time PCR, western blot, immunohistochemistry, electron microscopy, cytosolic iron assay, and salivary function were analyzed. Human salivary gland tissue analysis was also done. Lipogenesis and lipid deposition in the submandibular gland tissue occurred after ovariectomy. ROS generation, MDA+HAE was increased and GPX4 activity was decreased and in the OVX group compared to the CON group. Iron deposition in the submandibular gland tissue was increased in the OVX group. Submandibular gland fibrosis was increased and saliva secretion was decreased in the OVX group. In human submandibular gland analysis, lipid and iron deposition was also increased in the postmenopause group. This is the first in vivo study in which salivary gland dysfunction is associated with the ferroptosis in postmenopausal animal model. Increased lipid and iron deposition in normal submandibular gland tissues of postmenopausal women can suggest that the salivary gland dysfunction after menopause may be associated with the ferroptosis.

Objectives: The loss of signal during intraoperative neuromonitoring (IONM) using electromyography (EMG) in thyroidectomy is one of the biggest problems. We have developed a novel IONM system with an endotracheal tube (ETT) with an attached pressure sensor instead of EMG to detect laryngeal twitching. The aim of the present study was to investigate the feasibility and reliability of this novel IONM system using an ETT with pressure sensor during thyroidectomy in a porcine model., Methods: We developed an ETT-attached pressure sensor that uses the piezoelectric effect to measure laryngeal muscle twitching. Stimulus thresholds, amplitude, and latency of laryngeal twitching evaluated using the pressure sensor were compared to those measured using transcartilage needle EMG. The measured amplitude changes by EMG and the pressure sensor during recurrent laryngeal nerve (RLN) traction injury were compared., Results: No significant differences in stimulus threshold intensity between EMG and the pressure sensor were observed. The EMG amplitude detected at 0.3 mA, increased with increasing stimulus intensity. When the stimulus was more than 1.0 mA, the amplitude showed a plateau. In a RLN traction injury experiment, the EMG amplitude did not recover even 20 minutes after stopping RLN traction. However, the pressure sensor showed a mostly recovery., Conclusion: The change in amplitude due to stimulation of the pressure sensor showed a pattern similar to EMG. Pressure sensors can be feasibly and reliably used for RLN traction injury prediction, RLN identification, and preservation through the detection of laryngeal muscle twitching. Our novel IONM system that uses an ETT with an attached pressure sensor to measure the change of surface pressure can be an alternative to EMG in the future.

Human palatine tonsils are potential tissue source of multipotent mesenchymal stem cells (MSCs). The proliferation rate of palatine tonsil-derived MSCs (TMSCs) is far higher than that of bone marrow-derived MSCs (BMSCs) or adipose tissue-derived MSCs (ADSCs). In our previous study, we had found through DNA microarray analysis that tensin-3 (TNS3), a type of focal adhesion protein, was more highly expressed in TMSCs than in both BMSCs and ADSCs. Here, the role of TNS3 in TMSCs and its relationship with integrin were investigated. TNS3 expression was significantly elevated in TMSCs than in other cell types. Cell growth curves revealed a significant decrease in the proliferation and migration of TMSCs treated with siRNA for TNS3 (siTNS3). siTNS3 treatment upregulated p16 and p21 levels and downregulated SOX2 expression and focal adhesion kinase, protein kinase B, and c-Jun N-terminal kinase phosphorylation. siTNS3 transfection significantly reduced adipogenic differentiation of TMSCs and slightly decreased osteogenic and chondrogenic differentiation. Furthermore, TNS3 inhibition reduced active integrin beta-1 (ITGβ1) expression, while total ITGβ1 expression was not affected. Inhibition of ITGβ1 expression in TMSCs by siRNA showed similar results observed in TNS3 inhibition. Thus, TNS3 may play an important role in TMSC proliferation and differentiation by regulating active ITGβ1 expression.

Objectives: The sensitivity and positive predictive value of widely used intraoperative neuromonitoring (IONM) using electromyography (EMG) of the vocalis muscle in thyroid surgery are controversial. Thus, we developed a novel IONM system with an accelerometer sensor that uses the piezoelectric effect instead of EMG to detect laryngeal twitching. The objective of this study was to evaluate the feasibility and safety of this novel IONM system during thyroid surgery in a porcine model., Methods: We developed an accelerometer sensor that uses the piezoelectric effect to measure laryngeal twitching in three dimensions. This novel accelerometer sensor was placed in the anterior neck skin (transcutaneous) or postcricoid area. Stimulus thresholds, amplitude, and latency of laryngeal twitching measured using the accelerometer sensor were compared to those measured through EMG of the vocalis muscle., Results: The amplitudes of the accelerometer sensor at the anterior neck and postcricoid area were significantly lower than those of EMG because of differences in the measurement method used to evaluate laryngeal movement. However, no significant differences in stimulus thresholds between the EMG endotracheal tube and transcutaneous or postcricoid accelerometer sensors were observed., Conclusion: Accelerometer sensors located at the anterior neck or postcricoid area were able to identify laryngeal twitching. The stimulus intensity measured with these sensors was equivalent to that from conventional vocalis EMG. Our novel IONM system with an accelerometer sensor that checks changes in surface acceleration can be an alternative to EMG of the vocalis muscle for IONM in the future.

The alterations of the extracellular matrix (ECM) in lamina propria of the vocal folds are important changes that are associated with decreased vibrations and increased stiffness in aging vocal fold. The aim of this study was to investigate the differences in gene expression of lamina propria using next generation sequencing (NGS) in young and aging rats and to identify genes that affect aging-related ECM changes for developing novel therapeutic target molecule. Among the 40 genes suggested in the NGS analysis, voltage-gated calcium channels (VGCC) subunit alpha1 S (CACNA1S), VGCC auxiliary subunit beta 1 (CACNB1), and VGCC auxiliary subunit gamma 1 (CACNG1) were increased in the lamina propria of the old rats compared to the young rats. The synthesis of collagen I and III in hVFFs decreased after si-CACNA1S and verapamil treatment. The expression and activity of matrix metalloproteinases (MMP)-1 and -8 were increased in hVFFs after the treatment of verapamil. However, there was no change in the expression of MMP-2 and -9. These results suggest that some calcium channels may be related with the alteration of aging-related ECM in vocal folds. Calcium channel has promising potential as a novel therapeutic target for the remodeling ECM of aging lamina propria.

We describe a metal nanodisk-insulator-metal (MIM) structure that enhances lanthanide-based upconversion (UC) and downshifting (DS) simultaneously. The structure was fabricated using a nanotransfer printing method that facilitates large-area applications of nanostructures for optoelectronic devices. The proposed MIM structure is a promising way to harness the entire solar spectrum by converting both ultraviolet and near-infrared to visible light concurrently through resonant-mode excitation. The overall photoluminescence enhancements of the UC and DS were 174- and 29-fold, respectively.

Origins of the irreversible capacity loss were addressed through probing changes in the electronic and structural properties of hollow-structured Co3O4 nanoparticles (NPs) during lithiation and delithiation using electrochemical Co3O4 transistor devices that function as a Co3O4 Li-ion battery. Additive-free Co3O4 NPs were assembled into a Li-ion battery, allowing us to isolate and explore the effects of the Co and Li2O formation/decomposition conversion reactions on the electrical and structural degradation within Co3O4 NP films. NP films ranging between a single monolayer and multilayered film hundreds of nanometers thick prepared with blade-coating and electrophoretic deposition methods, respectively, were embedded in the transistor devices for in situ conduction measurements as a function of battery cycles. During battery operation, the electronic and structural properties of Co3O4 NP films in the bulk, Co3O4/electrolyte, and Co3O4/current collector interfaces were spatially mapped to address the origin of the initial irreversible capacity loss from the first lithiation process. Further, change in carrier injection/extraction between the current collector and the Co3O4 NPs was explored using a modified electrochemical transistor device with multiple voltage probes along the electrical channel.