Modulatory Effects of the Kuwanon-Rich Fraction from Mulberry Root Bark on the Renin-Angiotensin System.

In this study, we investigated the anti-hypertensive properties of mulberry products by modulating the renin-angiotensin system (RAS). Comparative analysis showed that the ethyl acetate fractions, particularly from the Cheongil and Daeshim cultivars, contained the highest levels of polyphenols and flavonoids, with concentrations reaching 110 mg gallic acid equivalent (GE)/g and 471 mg catechin equivalent (CE)/g of extract, respectively. The ethyl acetate fraction showed superior angiotensin-converting enzyme (ACE) inhibitory activity, mainly because of the presence of the prenylated flavonoids kuwanon G and H. UPLC/Q-TOF-MS analysis identified kuwanon G and H as the primary active components, which significantly contributed to the pharmacological efficacy of the extract. In vivo testing of mice fed a high-salt diet showed that the ethyl acetate fraction substantially reduced the heart weight and lowered the serum renin and angiotensinogen levels by 34% and 25%, respectively, highlighting its potential to modulate the RAS. These results suggested that the ethyl acetate fraction of mulberry root bark is a promising candidate for the development of natural ACE inhibitors. This finding has significant implications for the management of hypertension through RAS regulation and the promotion of cardiovascular health in the functional food industry.

A comprehensive dataset for home appliance control using ERP-based BCIs with the application of inter-subject transfer learning.

Brain-computer interfaces (BCIs) have a potential to revolutionize human-computer interaction by enabling direct links between the brain and computer systems. Recent studies are increasingly focusing on practical applications of BCIs-e.g., home appliance control just by thoughts. One of the non-invasive BCIs using electroencephalography (EEG) capitalizes on event-related potentials (ERPs) in response to target stimuli and have shown promise in controlling home appliance. In this paper, we present a comprehensive dataset of online ERP-based BCIs for controlling various home appliances in diverse stimulus presentation environments. We collected online BCI data from a total of 84 subjects among whom 60 subjects controlled three types of appliances (TV: 30, door lock: 15, and electric light: 15) with 4 functions per appliance, 14 subjects controlled a Bluetooth speaker with 6 functions via an LCD monitor, and 10 subjects controlled air conditioner with 4 functions via augmented reality (AR). Using the dataset, we aimed to address the issue of inter-subject variability in ERPs by employing the transfer learning in two different approaches. The first approach, "within-paradigm transfer learning," aimed to generalize the model within the same paradigm of stimulus presentation. The second approach, "cross-paradigm transfer learning," involved extending the model from a 4-class LCD environment to different paradigms. The results demonstrated that transfer learning can effectively enhance the generalizability of BCIs based on ERP across different subjects and environments.

Fully reconfigurable MEMS-based second-order coupled-resonator optical waveguide (CROW) with ultra-low tuning energy.

Integrated microring resonators are well suited for wavelength-filtering applications in optical signal processing, and cascaded microring resonators allow flexible filter design in coupled-resonator optical waveguide (CROW) configurations. However, the implementation of high-order cascaded microring resonators with high extinction ratios (ERs) remains challenging owing to stringent fabrication requirements and the need for precise resonator tunability. We present a fully integrated on-chip second-order CROW filter using silicon photonic microelectromechanical systems (MEMS) to adjust tunable directional couplers and a phase shifter using nanoscale mechanical out-of-plane waveguide displacement. The filter can be fully reconfigured with regard to both the ER and center wavelength. We experimentally demonstrated an ER exceeding 25 dB and continuous wavelength tuning across the full free spectral range of 0.123 nm for single microring resonator, and showed reconfigurability in second-order CROW by tuning the ER and resonant wavelength. The tuning energy for an individual silicon photonic MEMS phase shifter or tunable coupler is less than 22 pJ with sub-microwatt static power consumption, which is far better than conventional integrated phase shifters based on other physical modulation mechanisms.

Programmable MZI based on a silicon photonic MEMS-tunable delay line.

We report on a scalable and programmable integrated Mach-Zehnder interferometer (MZI) with a tunable free spectral range (FSR) and extinction ratio (ER). For the tunable path of the MZI, we designed and utilized a tunable delay line having high flexibility based on silicon photonic microelectromechanical systems (MEMS). By utilizing MEMS, the length of the delay line can be geometrically modified. In this way, there is no optical loss penalty other than the waveguide propagation loss as the number of tunable steps increases. Therefore, our device is more scalable in terms of optical loss than the previous approaches based on cascaded MZIs. In addition, the tuning energy required to reconfigure the length is only 8.46 pJ.

Unraveling prokaryotic diversity distribution and functional pattern on nitrogen and methane cycling in the subtropical Western North Pacific Ocean.

Prokaryotes play an important role in marine nitrogen and methane cycles. However, their community changes and metabolic modifications to the concurrent impact of ocean warming (OW), acidification (OA), deoxygenation (OD), and anthropogenic­nitrogen-deposition (AND) from the surface to the deep ocean remains unknown. We examined here the amplicon sequencing approach across the surface (0-200 m; SL), intermediate (200-1000 m; IL), and deep layers (1000-2200 m; DL), and characterized the simultaneous impacts of OW, OA, OD, and AND on the Western North Pacific Ocean prokaryotic changes and their functional pattern in nitrogen and methane cycles. Results showed that SL possesses higher ammonium oxidation community/metabolic composition assumably the reason for excess nitrogen input from AND and modification of their kinetic properties to OW adaptation. Expanding OD at IL showed hypoxic conditions in the oxygen minimum layer, inducing higher microbial respiration that elevates the dimerization of nitrification genes for higher nitrous oxide production. The aerobic methane-oxidation composition was dominant in SL presumably the reason for adjustment in prokaryotic optimal temperature to OW, while anaerobic oxidation composition was dominant at IL due to the evolutionary changes coupling with higher nitrification. Our findings refocus on climate-change impacts on the open ocean ecosystem from the surface to the deep-environment integrating climate-drivers as key factors for higher nitrous-oxide and methane emissions.

Utilizing Three-Dimensional Head-Lesser Trochanter Distance Could Further Reduce Leg Length Inequality in Primary Bipolar Hemiarthroplasty.

Background: The aim of this study was to investigate whether the use of three-dimensional (3-D) computed tomography (CT)-based head-lesser trochanter distance (HLD) could reduce leg length discrepancy (LLD) more than the use of a two-dimensional (2-D) plain film method in primary bipolar hemiarthroplasty. Methods: Propensity score matching (PSM) analysis was used to adjust the confounding factors. A retrospective comparative analysis of 128 patients was performed. In the control group, the leg length was equalized using the 2-D, plain film-based HLD. In the study group, primary bipolar hemiarthroplasty was performed using the 3-D CT-based HLD method. Postoperative LLDs were compared between the two groups using the method of Ranawat. In addition, the Harris hip score (HHS) was evaluated and compared at one year after surgery. Results: A significant difference was observed in mean postoperative LLD between the 2-D HLD group and the 3-D CT HLD group: 1.6 ± 1.2 mm (range, 0.1−6.0 mm) and 1.1 ± 1.2 mm (range, 0.1−5.1 mm), respectively (p < 0.05). Additionally, a higher percentage of patients in the 3-D CT HLD group had an LLD of less than 2 mm. The mean HHS at one year after surgery showed no significant difference between the two groups. Conclusions: To minimize the occurrence of LLD, HLD measurement from a CT scanner may be more accurate than an X-ray. The 2-D and 3-D HLD differences in the 3-D CT HLD group were statistically significant. Using a 3-D, CT-based HLD method might decrease the possibility of an LLD over 2 mm.

Edible Matrix Code with Photogenic Silk Proteins.

Counterfeit medicines are a healthcare security problem, posing not only a direct threat to patient safety and public health but also causing heavy economic losses. Current anticounterfeiting methods are limited due to the toxicity of the constituent materials and the focus of secondary packaging level protections. We introduce an edible, imperceptible, and scalable matrix code of information representation and data storage for pharmaceutical products. This matrix code is digestible as it is composed of silk fibroin genetically encoded with fluorescent proteins produced by ecofriendly, sustainable silkworm farming. Three distinct fluorescence emission colors are incorporated into a multidimensional parameter space with a variable encoding capacity in a format of matrix arrays. This code is smartphone-readable to extract a digitized security key augmented by a deep neural network for overcoming fabrication imperfections and a cryptographic hash function for enhanced security. The biocompatibility, photostability, thermal stability, long-term reliability, and low bit error ratio of the code support the immediate feasibility for dosage-level anticounterfeit measures and authentication features. The edible code affixed to each medicine can serve as serialization, track and trace, and authentication at the dosage level, empowering every patient to play a role in combating illicit pharmaceuticals.

Simultaneous Determination of Pyridate, Quizalofop-ethyl, and Cyhalofop-butyl Residues in Agricultural Products Using Liquid Chromatography-Tandem Mass Spectrometry.

An analytical method was developed to simultaneously determine pyridate, quizalofop-ethyl, and cyhalofop-butyl in brown rice, soybean, potato, pepper, and mandarin using LC-MS/MS. Purification was optimized using various sorbents: primary−secondary amine, octadecyl (C18) silica gel, graphitized carbon black, zirconium dioxide-modified silica particles, zirconium dioxide-modified silica particles (Z-SEP), and multi-walled carbon nanotubes (MWCNTs). Three versions of QuECHERS methods were then tested using the optimal purification agent. Finally, samples were extracted using acetonitrile and QuEChERS EN salts and purified using the Z-SEP sorbent. A six-point matrix-matched external calibration curve was constructed for the analytes. Good linearity was achieved with a determination coefficient ≥0.999. The limits of detection and quantification were 0.0075 mg/kg and 0.01 mg/kg, respectively. The method was validated after fortifying the target standards to the blank matrices at three concentration levels with five replicates for each concentration. The average recovery was within an acceptable range (70−120%), with a relative standard deviation <20%. The applicability of the developed method was evaluated with real-world market samples, all of which tested negative for these three herbicide residues. Therefore, this method can be used for the routine analysis of pyridate, quizalofop-ethyl, and cyhalofop-butyl in agricultural products.

Highly Reliable Flexible Device with a Charge Compensation Layer.

Flexible devices fabricated with a polyimide (PI) substrate are essential for foldable, rollable, and stretchable products and various applications. However, inherent technical challenges remain in mobile charge-induced device instabilities and image retention, significantly hindering future technologies. Here, we introduce a new barrier material, SiCOH, into the backplane of amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs) and applied it to production-level flexible panels. We found that the SiCOH layer effectively compensates for the surface charging induced by fluorine ions at the interface between the PI substrate and the barrier layer under bias stress, thereby preventing abnormal positive shifts in threshold voltage (Vth) and image disturbance. The a-IGZO TFTs and metal-insulator-metal and metal-insulator-semiconductor capacitors with a SiCOH layer demonstrate reliable device performance, Vth shifts, and capacitance changes with an increase in gate bias stress. A flexible device with SiCOH enables the suppression of abnormal Vth shifts associated with PIs and plays a vital role in image sticking. This work provides new insights into process integrity and paves the way for expediting versatile form factors.

Coherent terahertz wireless communication using dual-parallel MZM-based silicon photonic integrated circuits.

Coherent terahertz (THz) wireless communication using silicon photonics technology provides critical solutions for achieving high-capacity wireless transmission beyond 5G and 6G networks and seamless connectivity with fiber-based backbone networks. However, high-quality THz signal generation and noise-robust signal detection remain challenging owing to the presence of inter-channel crosstalk and additive noise in THz wireless environments. Here, we report coherent THz wireless communication using a silicon photonic integrated circuit that includes a dual-parallel Mach-Zehnder modulator (MZM) and advanced digital signal processing (DSP). The structure and fabrication of the dual-parallel MZM-based silicon photonic integrated circuit are systematically optimized using the figure of merit (FOM) method to improve the modulation efficiency while reducing the overall optical loss. The advanced DSP compensates for in-phase and quadrature (IQ) imbalance as well as phase noise by orthogonally decoupling the IQ components in the frequency domain after adaptive signal equalization and carrier phase estimation. The experimental results show a reduction in phase noise that induces degradation of transmission performance, successfully demonstrating error-free 1-m THz wireless transmission with bit-error rates of 10-6 or less at a data rate of 50 Gbps.

Integrated linkage-driven dexterous anthropomorphic robotic hand.

Robotic hands perform several amazing functions similar to the human hands, thereby offering high flexibility in terms of the tasks performed. However, developing integrated hands without additional actuation parts while maintaining important functions such as human-level dexterity and grasping force is challenging. The actuation parts make it difficult to integrate these hands into existing robotic arms, thus limiting their applicability. Based on a linkage-driven mechanism, an integrated linkage-driven dexterous anthropomorphic robotic hand called ILDA hand, which integrates all the components required for actuation and sensing and possesses high dexterity, is developed. It has the following features: 15-degree-of-freedom (20 joints), a fingertip force of 34N, compact size (maximum length: 218 mm) without additional parts, low weight of 1.1 kg, and tactile sensing capabilities. Actual manipulation tasks involving tools used in everyday life are performed with the hand mounted on a commercial robot arm.

Effects of polyimide curing on image sticking behaviors of flexible displays.

Flexible displays on a polyimide (PI) substrate are widely regarded as a promising next-generation display technology due to their versatility in various applications. Among other bendable materials used as display panel substrates, PI is especially suitable for flexible displays for its high glass transition temperature and low coefficient of thermal expansion. PI cured under various temperatures (260 °C, 360 °C, and 460 °C) was implemented in metal-insulator-metal (MIM) capacitors, amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFT), and actual display panels to analyze device stability and panel product characteristics. Through electrical analysis of the MIM capacitor, it was confirmed that the charging effect in the PI substrates intensified as the PI curing temperature increased. The threshold voltage shift (ΔVth) of the samples was found to increase with rising curing temperature under negative bias temperature stress (NBTS) due to the charging effect. Our analyses also show that increasing ΔVth exacerbates the image sticking phenomenon observed in display panels. These findings ultimately present a direct correlation between the curing temperature of polyimide substrates and the panel image sticking phenomenon, which could provide an insight into the improvement of future PI-substrate-based displays.

Self-Assembled Bimetallic Aluminum-Salen Catalyst for the Cyclic Carbonates Synthesis.

Bimetallic bis-urea functionalized salen-aluminum catalysts have been developed for cyclic carbonate synthesis from epoxides and CO2. The urea moiety provides a bimetallic scaffold through hydrogen bonding, which expedites the cyclic carbonate formation reaction under mild reaction conditions. The turnover frequency (TOF) of the bis-urea salen Al catalyst is three times higher than that of a µ-oxo-bridged catalyst, and 13 times higher than that of a monomeric salen aluminum catalyst. The bimetallic reaction pathway is suggested based on urea additive studies and kinetic studies. Additionally, the X-ray crystal structure of a bis-urea salen Ni complex supports the self-assembly of the bis-urea salen metal complex through hydrogen bonding.

Threshold voltage instability and polyimide charging effects of LTPS TFTs for flexible displays.

In this paper, we investigate the Vth shift of p-type LTPS TFTs fabricated on a polyimide (PI) and glass substrate considering charging phenomena. The Vth of the LTPS TFTs with a PI substrate positively shift after a bias temperature stress test. However, the Vth with a glass substrate rarely changed even with increasing stress. Such a positive Vth shift results from the negative charging of fluorine stemmed from the PI under the gate bias. In fact, the C-V characterization on the metal-insulator-metal capacitor reveals that charging at the SiO2/PI interface depends on the applied gate bias and the PI material, which agrees well with the TCAD simulation and SIMS analyses. As a result, the charging at the SiO2/PI interface contributes to the Vth shift of the LTPS TFTs leading to image sticking.

Assessing the Effects of Temperature and Oxygen Vacancy on Band Gap Renormalization in LaCrO3-δ: First-Principles and Experimental Corroboration.

Understanding the temperature dependence of functional properties in high-temperature gas sensors is vital for applications in combustion environments. Temperature effect on the electronic structure due to electron-phonon coupling is a key property of interest as this influences other responses of sensors. In this work, we assess the impact of temperature on band gap renormalization of pristine and oxygen-vacant LaCrO3-δ perovskite employing Allen-Heine-Cardona theory with first-principles simulations and corroborate with experimental observation. Antiferromagnetic cubic LaCrO3 shows a direct ground-state band gap of 2.62 eV that is reduced by over 1 eV due to the presence of oxygen vacancies, which can form endothermically. We find excellent agreement in temperature-dependent band gap shift in LaCrO3 between theory and an in-house experiment, proving that the theory can adequately predict renormalization on the band gap in a magnetic system. Band gaps in cubic LaCrO3-δ are found to monotonically narrow by 1.13 eV in pristine and by around 0.62 eV in oxygen-vacant structures as temperature increases from 0 to 1500 K. The predicted band gap variations are rationalized using an analytical model. The experimental zero-temperature band gaps are extracted from the model fits that can provide useful insights on the simulated band gaps.

Leakage Current Analysis Method for Metal Insulator Semiconductor Capacitors Through Low-Frequency Noise Measurement.

Use of thinner oxides to improve the operating speed of a complementary metal-oxidesemiconductor (CMOS) device causes serious gate leakage problems. Leakage current of the dielectric analysis method has I-V, C-V, and charge pumping, but the procedure is very complicated. In this premier work, we analyzed the leakage current of metal insulator semiconductor (MIS) capacitors with different initiators through low-frequency noise (LFN) measurement with simplicity and high sensitivity. The LFN measurement results show a correlation between power spectral density (SIG) and gate leakage current (IG). MIS capacitors of hafnium zirconium silicate (HZS, (HfZrO4)1-x (SiO2)x) were used for the experiments with varying SiO2 ratio (x = 0, 0.1, 0.2) of hafnium zirconium oxide (HZO, HfZrO4). As the SiO2 ratio increased, the leakage current decreased according to J-V measurement. Further, the C-V measurement confirmed that the oxide-trapped charge (Not) increased with increasing SiO2 ratio. Finally, the LFN measurement method revealed that the cause of leakage current reduction was trap density reduction of the insulator.

First-principles exploration of oxygen vacancy impact on electronic and optical properties of ABO3-δ (A = La, Sr; B = Cr, Mn) perovskites.

ABO3-δ perovskites are utilized in many applications including optical gas sensing for energy systems. Understanding the opto-electronic properties allows rational selection of the perovskite-based sensors from a diverse family of ABO3-δ perovskites, associated with the choices of A and B cations and range of oxygen concentrations. Herein, we assess the impact of oxygen vacancies on the electronic structure and optical response of pristine and oxygen-vacant ABO3-δ (A = La, Sr; B = Cr, Mn) perovskites via first-principles calculations. The endothermic formation energy for oxygen vacancies shows that the generation of ABO3-δ defect structures is thermodynamically possible. LaCrO3 and LaMnO3 have direct and indirect ground-state band gaps, respectively, whereas SrCrO3 and SrMnO3 are metallic. In the presence of an oxygen mono-vacancy, however, the band gap decreases in LaCrO3-δ and vanishes in LaMnO3-δ. In contrast to the decrease in the band gaps, the oxygen vacancies in ABO3-δ are found to increase optical absorption in the visible to near-infrared wavelength regime, and thus lower the onset energy of absorption compared with the pristine materials. Our assessments emphasize the role of the oxygen vacancy, or other possible oxygen non-stoichiometry defects, in perovskite oxides with respect to the opto-electronic performance parameters that are of interest for optical gas sensors for energy generation process environments.

Demonstration of photonics-aided terahertz wireless transmission system with using silicon photonics circuit: erratum.

We present an erratum for our recent paper [Opt. Express 28, 23397 (2020)] to include funding information in the funding section.

Demonstration of photonics-aided terahertz wireless transmission system with using silicon photonics circuit.

We experimentally demonstrate the use of silicon photonics circuit (SPC) in the simple and cost-effective photonics-aided Terahertz (THz) wireless transmission system. We perform theoretical investigation (with experimental confirmation) to understand that the system performance is more sensitive to the free space path loss (FSPL) at the THz wireless link than the SPC's insertion loss. The SPC, we design and fabricate, combines two incident optical carriers at different wavelengths and modulates one of two optical carriers with data to transfer, consequently reducing the system footprint that is indeed one of the key challenges that must be tackled for better practicability of the THz communication system. We perform experimental verification to show the feasibility of 40 Gb/s non-return-to-zero (NRZ) on-off-keying (OOK) signal transmission over 1.4 m wireless link for possibly its application in short-reach indoor wireless communication systems utilizing (sub-)THz frequency band such as, e.g., indoor WiFi, distributed antenna/radio systems, rack-to-rack data delivery, etc. The SPC could be further integrated with various photonic elements such as semiconductor optical amplifiers, laser diodes, and photo-mixers, which will enable the path towards all-photonic THz-wave synthesizers.

Photoelectric Silk via Genetic Encoding and Bioassisted Plasmonics.

Genetically encoded photoelectric silk that can convert photons to electrons (light to electricity) over a wide visible range in a self-power mode is reported. As silk is a versatile host material with electrical conductivity, biocompatibility, and processability, a photoelectric protein is genetically fused with silk by silkworm transgenesis. Specifically, mKate2, which is conventionally known as a far-red fluorescent protein, is used as a photoelectric protein. Characterization of the electrochemical and optical properties of mKate2 silk allows designing a photoelectric measurement system. A series of in situ photocurrent experiments support the sensitive and stable performance of photoelectric conversion. In addition, as a plasmonic nanomaterial with a broad spectral resonance, titanium nitride (TiN) nanoparticles are biologically hybridized into the silk glands, taking full advantage of the silkworms' open circulatory system as well as the absorption band of mKate2 silk. This biological hybridization via direct feeding of TiN nanoparticles further enhances the overall photoelectric conversion ability of mKate2 silk. It is envisioned that the biologically derived photoelectric protein, its ecofriendly scalable production by transgenic silkworms, and the bioassisted plasmonic hybridization can potentially broaden the biomaterial choices for developing next-generation biosensing, retina prosthesis, and neurostimulation applications.