Multifunction integrated lithium niobate photonic chip for photon pairs generation and manipulation.

We report on a unique photonic quantum source chip highly integrating four-stage photonic elements in a lithium niobate (LN) waveguide circuit platform, where an aperiodically poled LN (APPLN) electro-optic (EO) polarization mode converter (PMC) is sandwiched between two identical type-0 PPLN spontaneous parametric down-converters (SPDCs), followed by an EO phase controller (PC). These core nonlinear optic and EO building blocks on the chip are systematically characterized stage by stage to show its high performance as an integrated quantum source. The APPLN EO PMC, optimally constructed by a genetic algorithm, is characterized to have a broad bandwidth (>13 nm), benefiting an efficient control of broadband type-0 SPDC photon pairs featuring a short correlation time. We demonstrate an efficient conversion of the |VV> photon-pair state generated from the first PPLN SPDC stage to the |HH> state through the APPLN EO PMC stage over its operating bandwidth, a broadband or broadly tunable polarization-entangled state can thus be possibly produced via the superposition of the |VV> state generated from the other PPLN SPDC on the third stage of the chip. Such a state can be further manipulated into two of the Bell states if the relative phases between the two polarization states can be properly modulated through the EO PC on the fourth stage of the chip. Such a multifunction integrated quantum photonic source chip can be of high value to developing a compact, efficient, and high-speed quantum information processor.

Design of dual peptide-conjugated hydrogels for proliferation and differentiation of human pluripotent stem cells.

Completely synthetic cell cultivation materials for human pluripotent stem cells (hPSCs) are important for the future clinical use of hPSC-derived cells. Currently, cell culture materials conjugated with extracellular matrix (ECM)-derived peptides are being prepared using only one specific integrin-targeting peptide. We designed dual peptide-conjugated hydrogels, for which each peptide was selected from different ECM sites: the laminin ß4 chain and fibronectin or vitronectin, which can target α6ß1 and α2ß1 or αVß5. hPSCs cultured on dual peptide-conjugated hydrogels, especially on hydrogels conjugated with peptides obtained from the laminin ß4 chain and vitronectin with a low peptide concentration of 200 µg/mL, showed high proliferation ability over the long term and differentiated into cells originating from 3 germ layers in vivo as well as a specific lineage of cardiac cells. The design of grafting peptides was also important, for which a joint segment and positive amino acids were added into the designed peptide. Because of the designed peptides on the hydrogels, only 200 µg/mL peptide solution was sufficient for grafting on the hydrogels, and the hydrogels supported hPSC cultures long-term; in contrast, in previous studies, greater than 1000 µg/mL peptide solution was needed for the grafting of peptides on cell culture materials.

The relationships between physical function, nutrition, cognitive function, depression, and sleep quality for facility-dwelling older adults with dynapenia.

BACKGROUND: The growing population of older adults worldwide is associated with an extended life expectancy and an increasing proportion of older adults with dynapenia. Most research on dynapenia has involved only populations of older adults living in the community; little research has examined the effects of risk factors on sleep quality among older adults with dynapenia residing in assisted living facilities. AIM: This study examined the relationships among physical function, nutrition, cognitive function, depression, and sleep quality among older adults with dynapenia residing in assisted living facilities. METHODS: In this cross-sectional study, data on physical function, nutrition, cognitive function, depression, and sleep quality was collected from 178 older adults with dynapenia residing in assisted living facilities, who were selected using purposive sampling. Descriptive statistical analysis, independent-sample t tests, chi-squared tests, and logistic regression analysis were performed using SPSS 25.0. RESULTS: The statistical analyses revealed correlations between sleep quality and age (t = 2.37, p < 0.05), level of education (χ2 = 3.85, p < 0.05), grip strength (t = 3.40, p < 0.01), activities of daily living (t = 4.29, p < 0.001), instrumental activities of daily living (t = 2.23, p < 0.001), calf circumference (t = 2.89, p < 0.01), Mini Nutritional Assessment scores (t = 2.29, p < 0.05), Mini Mental State Exam (MMSE) scores (t = 4.50, p < 0.001), and Geriatric Depression Scale (GDS) scores (t = - 4.20, p < 0.001). Calf circumference (OR = 0.8, 95% CI = 0.650.97, p < 0.05), GDS score (OR = 1.42, 95% CI = 1.05-1.92, p < 0.05), and MMSE score (OR = 0.85, 95% CI = 0.73-0.97, p < 0.05) were related to sleep quality among the sample population. CONCLUSION: Physical function, nutrition, cognitive function, and depression affect the sleep quality of older adults with dynapenia residing in assisted living facilities. Facility nurses must regularly assess these aspects of their patients to ensure that facility-dwelling older adults can maintain their physical function and improve their health to improve the quality of their sleep.

Next-generation materials for RNA-lipid nanoparticles: lyophilization and targeted transfection.

RNA, including mRNA, siRNA and miRNA, is part of a new class of patient treatments that prevent and treat several diseases. As an alternative to DNA therapy using plasmid DNA, RNA functions in the cellular cytosol, avoiding the potential risks of insertion into patient genomes. RNA drugs, including mRNA vaccines, need carrier materials for delivery into the patient's body. Several delivery carriers of mRNA, such as cationic polymers, lipoplexes, lipid-polymer nanoparticles and lipid nanoparticles (LNPs), have been investigated. For clinical applications, one of the most commonly selected types of RNA delivery carrier is LNPs, which are typically formed with (a) ionizable lipids, which bind to RNA; (b) cholesterol for stabilization; (c) phospholipids to form the LNPs; and (d) polyethylene glycol-conjugated lipids to prevent aggregation and provide stealth characteristics. Most RNA-LNP research has been devoted to achieving highly efficient RNA expression in vitro and in vivo. It is also necessary to study the extended storage of RNA-LNPs under mild conditions. One of the most efficient methods to store RNA-LNPs for a long time is to prepare freeze-dried (lyophilized) RNA-LNPs. Future research should include investigating LNP materials for the development of freeze-dried RNA-LNPs using optimal lipid components and compositions with optimal cryoprotectants. Furthermore, the development of sophisticated RNA-LNP materials for targeted transfection into specific tissues, organs or cells will be a future direction in the development RNA therapeutics. We will discuss the prospects for the development of next-generation RNA-LNP materials.

Broadband tunable electro-optic switch/power divider as potential building blocks in integrated lithium niobate photonics.

We demonstrate an electro-optic (EO) switch or in general, an EO controllable power divider based on a periodically poled lithium niobate (PPLN) polarization mode converter (PMC) and a five-waveguide adiabatic coupler integrated on a Ti:LN photonic circuit chip. In this integrated photonic circuit (IPC) device, the PPLN works as an EO controllable polarization rotator (and therefore a PMC), while the adiabatic coupler functions as a broadband polarization beam splitter (PBS). The 1-cm long PPLN EO PMC of the IPC device is characterized to have a half-wave (or switching) voltage of Vπ∼20 V and a conversion bandwidth of ∼2.6 nm. The splitting ratios of the adiabatic coupler PBS in the IPC device are >99% for both polarization modes over a broad spectral range from 1500-1640 nm. The EO mode of the implemented IPC device is activated when the PPLN EO PMC section is driven by an external voltage; the characterized EO switching/power division behavior of the device is in good agreement with the theoretical fit. The tunability of the EO IPC device in the 100-nm experimental spectral range is also demonstrated via the temperature tuning. The featured broad tunability and high integrability of the EO device presented in this study facilitates it to be an advantageous building block for realizing an on-chip photonic system.

Simultaneous electro-optic spectral switching and Q switching in a dual-wavelength Nd:YVO4 laser based on an aperiodic optical superlattice lithium niobate.

We report the demonstration of an electro-optic (EO) switchable dual-wavelength (1064- and 1342-nm) Nd:YVO4 laser based on an aperiodically poled lithium niobate (APPLN) chip whose domain structure is designed using aperiodic optical superlattice (AOS) technology. The APPLN works as a wavelength-dependent EO polarization-state controller in the polarization-dependent laser gain system to enable switching among multiple laser spectra simply by voltage control. When the APPLN device is driven by a voltage-pulse train modulating between a VHQ (in which target laser lines obtain gain) and a VLQ (in which laser lines are gain suppressed), the unique laser system can produce Q-switched laser pulses at dual wavelengths 1064 and 1342 nm, single wavelength 1064 nm, and single wavelength 1342 nm, as well as their non-phase-matched sum-frequency and second-harmonic generations at VHQ = 0, 267, and 895 V, respectively. A laser can benefit from such a novel, to the best of our knowledge, simultaneous EO spectral switching and Q switching mechanisms to increase its processing speed and multiplexity for versatile applications.

Purification of Colon Carcinoma Cells from Primary Colon Tumor Using a Filtration Method via Porous Polymeric Filters.

Cancer stem cells (CSCs) or cancer-initiating cells (CICs) are key factors for tumor generation and metastasis. We investigated a filtration method to enhance CSCs (CICs) from colon carcinoma HT-29 cells and primary colon carcinoma cells derived from patient colon tumors using poly(lactide-co-glycolic acid)/silk screen (PLGA/SK) filters. The colon carcinoma cell solutions were permeated via porous filters to obtain a permeation solution. Then, the cell cultivation media were permeated via the filters to obtain the recovered solution, where the colon carcinoma cells that adhered to the filters were washed off into the recovered solution. Subsequently, the filters were incubated in the culture media to obtain the migrated cells via the filters. Colon carcinoma HT-29 cells with high tumorigenicity, which might be CSCs (CICs), were enhanced in the cells in the recovered solution and in the migrated cells based on the CSC (CIC) marker expression, colony-forming unit assay, and carcinoembryonic antigen (CEA) production. Although primary colon carcinoma cells isolated from colon tumor tissues contained fibroblast-like cells, the primary colon carcinoma cells were purified from fibroblast-like cells by filtration through PLGA/SK filters, indicating that the filtration method is effective in purifying primary colon carcinoma cells.

Ultra-compact, broadband adiabatic passage optical couplers in thin-film lithium niobate on insulator waveguides.

We report the first demonstration of broadband adiabatic directional couplers in thin-film lithium niobate on insulator (LNOI) waveguides. A three LN-waveguide configuration with each waveguide having a ridge cross section of less than 1 square micron, built atop a layer of SiO2 based on a 500-µm-thick Si substrate, has been designed and constructed to optically emulate a three-state stimulated Raman adiabatic passage system, with which a unique counterintuitive adiabatic light transfer phenomenon in a high coupling efficiency of >97% (corresponding to a >15 dB splitting ratio) spanning telecom S, C, and L bands for both TE and TM polarization modes has been observed for a 2-mm long coupler length. An even broader operating bandwidth of >800 nm of the device can be found from the simulation fitting of the experimental data. The footprint of the realized LNOI adiabatic coupler has been reduced by >99% compared to its bulk counterparts. Such an ultra-compact, broadband LNOI adiabatic coupler can be further used to implement or integrate with various photonic elements, a potential building block for realizing large-scale integrated photonic (quantum) circuits in LN.

Identifying Hybrid DDoS Attacks in Deterministic Machine-to-Machine Networks on a Per-Deterministic-Flow Basis.

The Deterministic Network (DetNet) is becoming a major feature for 5G and 6G networks to cope with the issue that conventional IT infrastructure cannot efficiently handle latency-sensitive data. The DetNet applies flow virtualization to satisfy time-critical flow requirements, but inevitably, DetNet flows and conventional flows interact/interfere with each other when sharing the same physical resources. This subsequently raises the hybrid DDoS security issue that high malicious traffic not only attacks the DetNet centralized controller itself but also attacks the links that DetNet flows pass through. Previous research focused on either the DDoS type of the centralized controller side or the link side. As DDoS attack techniques are evolving, Hybrid DDoS attacks can attack multiple targets (controllers or links) simultaneously, which are difficultly detected by previous DDoS detection methodologies. This study, therefore, proposes a Flow Differentiation Detector (FDD), a novel approach to detect Hybrid DDoS attacks. The FDD first applies a fuzzy-based mechanism, Target Link Selection, to determine the most valuable links for the DDoS link/server attacker and then statistically evaluates the traffic pattern flowing through these links. Furthermore, the contribution of this study is to deploy the FDD in the SDN controller OpenDayLight to implement a Hybrid DDoS attack detection system. The experimental results show that the FDD has superior detection accuracy (above 90%) than traditional methods under the situation of different ratios of Hybrid DDoS attacks and different types and scales of topology.

A Spatiotemporal-Oriented Deep Ensemble Learning Model to Defend Link Flooding Attacks in IoT Network.

(1) Background: Link flooding attacks (LFA) are a spatiotemporal attack pattern of distributed denial-of-service (DDoS) that arranges bots to send low-speed traffic to backbone links and paralyze servers in the target area. (2) Problem: The traditional methods to defend against LFA are heuristic and cannot reflect the changing characteristics of LFA over time; the AI-based methods only detect the presence of LFA without considering the spatiotemporal series attack pattern and defense suggestion. (3) Methods: This study designs a deep ensemble learning model (Stacking-based integrated Convolutional neural network-Long short term memory model, SCL) to defend against LFA: (a) combining continuous network status as an input to represent "continuous/combination attacking action" and to help CNN operation to extract features of spatiotemporal attack pattern; (b) applying LSTM to periodically review the current evolved LFA patterns and drop the obsolete ones to ensure decision accuracy and confidence; (c) stacking System Detector and LFA Mitigator module instead of only one module to couple with LFA detection and mediation at the same time. (4) Results: The simulation results show that the accuracy rate of SCL successfully blocking LFA is 92.95%, which is 60.81% higher than the traditional method. (5) Outcomes: This study demonstrates the potential and suggested development trait of deep ensemble learning on network security.

The Relations Among Physical Indicators, Cognitive Status, Community Participation, and Depression of the Frail Male Elderly in Taiwan.

This study explored the basic attributes, physiological indices, cognitive states, and community participation of older male outpatients with frailty for predicting depression. Questionnaires were collected using purposive sampling from a medical clinic in a teaching hospital in northern Taiwan. One hundred and ninety frail men enrolled as participants. The results revealed that older male adults with frailty, the age, residence, income, self-reported health status, alcohol consumption, total instrumental activities of daily living (IADL) scores in physiological indices, IADL grouping, cognitive state score, each Mini-Mental State Examination category, and involvement and dedication scores exhibited statistical differences from depression scores. Depression determinants, such as an excellent and normal self-reported health status and IADL total score, could predict the depression status of male older adults with frailty. Nursing personnel should assess the self-reported health status and self-care ability of male older adults with frailty early to prevent or delay geriatric depression.

Electro-optically spectrum switchable, multiwavelength optical parametric oscillators based on aperiodically poled lithium niobate.

We report the first fast switchable multiwavelength optical parametric oscillator based on aperiodic optical superlattice technology. The constructed aperiodically poled lithium niobate (APPLN) integrates the functionalities of two quasi-phase-matching devices on a chip to work simultaneously as an electro-optic (EO) switchable notch-like filter and a multiline optical parametric downconverter. When such an APPLN is built in a 1064-nm-pumped optical resonator system, we achieve the oscillation of dual signals at 1540 and 1550 nm, for a single signal at 1540 nm, and a single signal at 1550 nm in the system when the 3-cm-long APPLN is driven by 0 V, 354 V, and 805 V, respectively. The switching among the three signal spectra is operationally simple and electro-optically fast. The electro-optically switched signals also feature enhanced power spectral density due to the unique EO gain-spectrum filtering mechanism employed in this work.

A Mobility Aware Binary Tree Algorithm to Resolve RFID Jam and Bottleneck Problems in a Next Generation Specimen Management System.

Hospitals are continuously working to reduce delayed analysis and specimen errors during transfers from testing stations to clinical laboratories. Radio-frequency identification (RFID) tags, which provide automated specimen labeling and tracking, have been proposed as a solution to specimen management that reduces human resource costs and analytic delays. Conventional RFID solutions, however, confront the problem of traffic jams and bottlenecks on the conveyor belts that connect testing stations with clinical laboratories. This mainly results from methods which assume that the arrival rate of specimens to laboratory RFID readers is fixed/stable, which is unsuitable and impractical in the real world. Previous RFID algorithms have attempted to minimize the time required for tag identification without taking the dynamic arrival rates of specimens into account. Therefore, we propose a novel RFID anti-collision algorithm called the Mobility Aware Binary Tree Algorithm (MABT), which can be used to improve the identification of dynamic tags within the reader's coverage area and limited dwell time.

Quantifying source apportionment for ambient haze: An image haze extraction approach with air quality monitoring data.

The annual average concentration of fine particles (PM2.5) in Taiwan has been decreasing yearly. However, ambient haze has not abated and visibility is still poor. This study proposes a method for quantifying the source apportionment of ambient haze from various constituents, namely measured PM2.5, moisture, and secondary organic aerosols (SOA, represented by the sum of measured O3 and NO2 levels). This study's model-based demisting technology integrated image haze extracting technology with air quality monitoring data. The images for haze extraction were from the instant cameras of the Taiwan Environmental Protection Agency's air quality monitoring stations (AQMSs). Results indicate that haze constituents with the product of light extinction and scene depth have very high correlation (R2 ≥ 0.8452), which demonstrate that this quantification approach was successful. The contributions of ambient haze from various constituents had quarterly and regional variations in the eastern, northern, central, and southern regions of Taiwan, which are slightly, lowly, moderately, and heavily contaminated areas, respectively. Each area was assigned a selected representative AQMS to represent its ambient haze characteristics. Cases where the dominant contributors to haze were PM2.5, moisture, and SOA were studied, in addition to the event days of PM2.5 and ozone. We detail the limits of this approach, especially with regard to the use of images. This approach can help administrators understand the composition of ambient haze to generate effective haze strategies and policies. Residents can use this method to determine the health effects of daily haze.

Social-Aware Peer Discovery for Energy Harvesting-Based Device-to-Device Communications.

In Device-to-Device (D2D) communications, the first step is to find all of the neighboring peers in the network by performing a peer discovery process. Most previous studies use the social behaviors of the users to adjust the sending rates of the peer discovery messages (i.e., beacons) under the constraint of consumed power for increasing the Peer Discovery Ratio (PDR). However, these studies do not consider the potential for energy harvesting, which allows for the User Equipments (UEs) to procure additional power within charging areas. Accordingly, this paper proposes an Energy-Ratio Rate Decision (ERRD) algorithm that comprises three steps, namely Social Ratio Allocation (SRA), Energy Ratio Allocation (ERA), and Beacon Rate Decision (BRD). The SRA step determines the allocated power quantum for each UE from the total budget power based on the social behavior of the UE. The ERA step then adjusts this allocated power quantum in accordance with the power that is harvested by the UE. Finally, the BRD step computes the beacon rate for the UE based on the adjusted power quantum. The simulation results show that ERRD outperforms the previously-reported Social-Based Grouping (SBG) algorithm by 190% on the PDR for a budget power of one watt and 8% for a budget power of 20 watts.

Broadband on-chip polarization mode splitters in lithium niobate integrated adiabatic couplers.

We report, to the best of our knowledge, the first broadband polarization mode splitter (PMS) based on the adiabatic light passage mechanism in the lithium niobate (LiNbO3) waveguide platform. A broad bandwidth of ~140 nm spanning telecom S, C, and L bands at polarization-extinction ratios (PER) of >20 dB and >18 dB for the TE and TM polarization modes, respectively, is found in a five-waveguide adiabatic coupler scheme whose structure is optimized by an adiabaticity engineering process in titanium-diffused LiNbO3 waveguides. When the five-waveguide PMS is integrated with a three-waveguide "shortcut to adiabaticity" structure, we realize a broadband, high splitting-ratio (ηc) mode splitter for spatial separation of TE- (H-) polarized pump (700-850 nm for ηc>99%), TM- (V-) polarized signal (1510-1630 nm for ηc>97%), and TE- (H-) polarized idler (1480-1650 nm for ηc>97%) modes. Such a unique integrated-optical device is of potential for facilitating the on-chip implementation of a pump-filtered, broadband tunable entangled quantum-state generator.

Heat stress upregulates G-T mismatch binding activities in zebrafish (Danio rerio) embryos preexposed and nonexposed to a sublethal level of cadmium (Cd).

G-T mispair frequently appears in eukaryotic DNA due to the spontaneous deamination of 5-methylcytosine paired with guanine and is therefore an important target for DNA mismatch repair (MMR). Our earlier studies showed the downregulation of G-T binding activities in cadmium (Cd)-exposed (Danio rerio) embryos. Since elevation of water temperature was reported to increase Cd toxicity in zebrafish, this study explored whether heat stress affected zebrafish mismatch binding capacity in the absence or presence of Cd. Heat stress (37 °C for 30 min) induced heat shock protein 70 mRNA expression in embryos at 10 and 24 h post fertilization (hpf). Heat stress weakly upregulated normal G-T sensing machinery and inhibited G-T recognition activity in embryos preexposed to 3 µM Cd for 9 h. Either heat shock or a 23-h Cd treatment alone caused a 1.7-fold stimulation of G-T binding capacity in 24 hpf embryos and heat stress of Cd-preexposed embryos further enhanced G-T binding activity to 2.5 fold of control. Normal and Cd-downregulated loop binding activities in 10 and 24 hpf embryos were almost unreactive to heat shock. Heat stress-upregulated G-T sensing in nonexposed, but not in Cd-preexposed, 24 hpf embryos correlated with stronger gene activities encoding MMR-linked mismatch detecting factors MutS homolog 2 and 6 plus a higher DNA binding activity of the transcription factor Sp1 that regulates msh2/msh6 expression. Our results suggested the importance of heat shock response in facilitating the correction of G-T mismatch in developing zebrafish even under Cd exposure.

Quantum metasurface for multiphoton interference and state reconstruction.

Metasurfaces based on resonant nanophotonic structures have enabled innovative types of flat-optics devices that often outperform the capabilities of bulk components, yet these advances remain largely unexplored for quantum applications. We show that nonclassical multiphoton interferences can be achieved at the subwavelength scale in all-dielectric metasurfaces. We simultaneously image multiple projections of quantum states with a single metasurface, enabling a robust reconstruction of amplitude, phase, coherence, and entanglement of multiphoton polarization-encoded states. One- and two-photon states are reconstructed through nonlocal photon correlation measurements with polarization-insensitive click detectors positioned after the metasurface, and the scalability to higher photon numbers is established theoretically. Our work illustrates the feasibility of ultrathin quantum metadevices for the manipulation and measurement of multiphoton quantum states, with applications in free-space quantum imaging and communications.

Asymmetric adiabatic couplers for fully-integrated broadband quantum-polarization state preparation.

Spontaneous parametric down-conversion (SPDC) is a widely used method to generate entangled photons, enabling a range of applications from secure communication to tests of quantum physics. Integrating SPDC on a chip provides interferometric stability, allows to reduce a physical footprint, and opens a pathway to true scalability. However, dealing with different photon polarizations and wavelengths on a chip presents a number of challenging problems. In this work, we demonstrate an on-chip polarization beam-splitter based on z-cut titanium-diffused lithium niobate asymmetric adiabatic couplers (AAC) designed for integration with a type-II SPDC source. Our experimental measurements reveal unique polarization beam-splitting regime with the ability to tune the splitting ratios based on wavelength. In particular, we measured a splitting ratio of 17 dB over broadband regions (>60 nm) for both H- and V-polarized lights and a specific 50%/50% splitting ratio for a cross-polarized photon pair from the AAC. The results show that such a system can be used for preparing different quantum polarization-path states that are controllable by changing the phase-matching conditions in the SPDC over a broad band. Furthermore, we propose a fully integrated electro-optically tunable type-II SPDC polarization-path-entangled state preparation circuit on a single lithium niobate photonic chip.

Dispersion-corrected frequency-resolved optical gating.

The phase retrieval algorithm of a frequency-resolved optical gating (FROG) is generalized to handle traces seriously distorted by group delay dispersion and non-uniform phase-matching spectra arising from the nonlinear crystal. In our proof-of-concept experiments, 15 mm thick aperiodically poled lithium niobate was employed in FROG, and successfully reconstructed chirped signal pulses were actually stretched by >5 times inside the crystal. This method is particularly promising in the measurement of weak few-cycle pulses produced by supercontinuum generation in fibers.