Multifunctional Modulator Research Articles

Rayleigh wave manipulation based on phase shift between two periodic surface corrugations

The propagation of Rayleigh waves along solid surfaces has attracted great attention due to its ubiquity in seismic waves, non-destructive evaluation, acoustic surface wave devices, and so on. Moreover, Rayleigh waves in periodic structures and their related band gaps caused by Bragg resonances have also been investigated. In this paper, we theoretically and experimentally demonstrate the propagation mechanism of Rayleigh waves along the side wall of a periodically corrugated aluminum plate. As expected, the band gap structures are observed in the spectrum of Rayleigh waves. However, not all the band gaps are caused by the Bragg resonances. The additional band gaps created by the interference of different transverse modes are observed. Different from the well-known Bragg resonance, the different mode interference, producing stronger energy attenuation and wider band gap, is called non-Bragg resonances. The two resonances can be manipulated by varying the phase shift of two sidewall corrugations, achieving an effective prohibition of Rayleigh wave propagation. These findings on Rayleigh wave propagation in periodic structures provide a comprehensive understanding of wave-structure interactions, which can be used to regulate elastic waves in various applications, such as multifunctional elastic wave separators, filters, and modulators.

THz broadband and dual-channel perfect absorbers based on patterned graphene and vanadium dioxide metamaterials.

This paper proposes a novel and perfect absorber based on patterned graphene and vanadium dioxide hybrid metamaterial, which can not only achieve wide-band perfect absorption and dual-channel absorption in the terahertz band, but also realize their conversion by adjusting the temperature to control the metallic or insulating phase of VO2. Firstly, the absorption spectrum of the proposed structure is analyzed without graphene, where the absorption can reach as high as 100% at one frequency point (f = 5.956 THz) when VO2 is in the metal phase. What merits attention is that the addition of graphene above the structure enhances the almost 100% absorption from one frequency point (f = 5.956 THz) to a wide frequency band, in which the broadband width records 1.683 THz. Secondly, when VO2 is the insulating phase, the absorption of the metamaterial structure with graphene outperforms better, and two high absorption peaks are formed, logging 100% and 90.7% at f3 = 5.545 THz and f4 = 7.684 THz, respectively. Lastly, the adjustment of the Fermi level of graphene from 0.8 eV to 1.1 eV incurs an obvious blueshift of the absorption spectra, where an asynchronous optical switch can be achieved at fK1 = 5.782 THz and fK2 = 6.898 THz. Besides, the absorber exhibits polarization sensitivity at f3 = 5.545 THz, and polarization insensitivity at f4 = 7.684 THz with the shift in the polarization angle of incident light from 0° to 90°. Accordingly, this paper gives insights into the new method that increases the high absorption width, as well as the great potential in the multifunctional modulator.

Application of additional high-frequency modulation to reduce influence of residual amplitude modulation LiNbO3 phase modulator on fiber optical gyroscope signal

Residual amplitude modulation in LiNbO3 phase modulator is one of the key factors that limit the accuracy of high-sensitive fiber-optical sensors. A fiber-optical gyroscope is an angular velocity sensor whose sensitivity is better than 0.001 °/h. Optical light intensity changes after phase modulator is a reason for wrong phase difference that introduces an error in the angular velocity signal. Most existing residual amplitude modulation suppression methods are based on reduction of back reflections between an optical fiber and integrated optical waveguide, absorbing groove to suppress or reduce reflection on the bottom face, and algorithmic compensation. In this paper, new approach to reduce residual amplitude modulation in LiNbO3 for fiber optical gyroscope application is presented. Method feature is an application of additional differential signal modulation with uniform amplitude distribution in the input signal voltage range of the phase modulator. The proposed method allows to suppress residual amplitude modulation of the multifunctional integrated optical circuit phase modulator more than 3 times using additional triangle signal modulation with the frequency f = 200.09 MHz and power P = 36 dBm. This method is suitable for improving fiber optical gyroscope accuracy. Moreover, it could be applied for any fiber-optic sensors based on LiNbO3 phase modulator. The paper will be of interest to specialists in the field of highly sensitive fiber optical sensors, fiber, and integrated optics.

Switchable triple plasmon-induced transparency in graphene sandwich metamaterial structures

In this research, a metamaterial structure composed of graphene sandwich structure is put forward to achieve triple plasmon-induced transparency. This phenomenon is generated by bright–bright modes interaction in the proposed structure, and the results calculated though couple mode theory are consistent with the simulation ones using finite difference time domain method. In addition, the effects of graphene Fermi level and scattering rate on the transmission spectrum are also discussed. It is found that the five-fold switching effects are achieved with the modulation depths (MDs) of 92%, 91%, 95%, 90% and 94%, respectively. What is more, the different graphene strip can also be adjusted by changing Fermi levels to achieve the switching effects with the MDs of 98% and 97%. This model has the prospect to be applied in multi-functional modulators and optical switches in terahertz band.

A 3D-printed molybdenum-containing scaffold exerts dual pro-osteogenic and anti-osteoclastogenic effects to facilitate alveolar bone repair

The positive regulation of bone-forming osteoblast activity and the negative feedback regulation of osteoclastic activity are equally important in strategies to achieve successful alveolar bone regeneration. Here, a molybdenum (Mo)-containing bioactive glass ceramic scaffold with solid-strut-packed structures (Mo-scaffold) was printed, and its ability to regulate pro-osteogenic and anti-osteoclastogenic cellular responses was evaluated in vitro and in vivo. We found that extracts derived from Mo-scaffold (Mo-extracts) strongly stimulated osteogenic differentiation of bone marrow mesenchymal stem cells and inhibited differentiation of osteoclast progenitors. The identified comodulatory effect was further demonstrated to arise from Mo ions in the Mo-extract, wherein Mo ions suppressed osteoclastic differentiation by scavenging reactive oxygen species (ROS) and inhibiting mitochondrial biogenesis in osteoclasts. Consistent with the in vitro findings, the Mo-scaffold was found to significantly promote osteoblast-mediated bone formation and inhibit osteoclast-mediated bone resorption throughout the bone healing process, leading to enhanced bone regeneration. In combination with our previous finding that Mo ions participate in material-mediated immunomodulation, this study offers the new insight that Mo ions facilitate bone repair by comodulating the balance between bone formation and resorption. Our findings suggest that Mo ions are multifunctional cellular modulators that can potentially be used in biomaterial design and bone tissue engineering.

Rationally Designed Molecules Synergistically Modulate Multifaceted Aβ Toxicity, Microglial Activation, and Neuroinflammation.

Synergistic modulation of multifaceted toxicity is the key to tackle multifactorial Alzheimer's disease (AD). The etiology of AD includes amyloid β (Aβ) amyloidosis, metal ion dyshomeostasis, reactive oxygen species (ROS), oxidative stress, mitochondrial damage, and neuroinflammation. We rationally designed multifunctional modulators by integrating pharmacophores for metal chelation, antioxidant and anti-inflammatory properties, and modulation of Aβ42 aggregation on the naphthalene monoimide (NMI) scaffold. The in vitro and cellular studies of NMIs revealed that M3 synergistically modulates metal-independent and -dependent amyloid toxicity, scavenges ROS, alleviates oxidative stress, and emulates Nrf2-mediated stress response in neuronal cells. M3 effectively reduced structural and functional damage of mitochondria, reduced Cyt c levels, and rescued cells from apoptosis. The biological atomic force microscopy and Western blot analysis revealed the ability of M3 to suppress microglial activation and neuroinflammation through inhibition of the NF-κβ pathway. The synergistic action of M3 is in agreement with our design strategy to develop a multifunctional therapeutic candidate by integrating multiple pharmacophores with distinct structural and functional elements to ameliorate the multifaceted toxicity of AD.

Modulatory effect of long-term treatment with escitalopram and clonazepam on the expression of anxiety-related neuropeptides: neuromedin U, neuropeptide S and their receptors in the rat brain

Newly identified multifunctional peptidergic modulators of stress responses: neuromedin U (NMU) and neuropeptide S (NPS) are involved in the wide spectrum of brain functions. However, there are no reports dealing with potential molecular relationships between the action of diverse anxiolytic or antidepressant drugs and NMU and NPS signaling in the brain. The present work was therefore focused on local expression of the aforementioned stress-related neuropeptides in the rat brain after long-term treatment with escitalopram and clonazepam. Studies were carried out on adult, male Sprague-Dawley rats that were divided into 3 groups: animals injected with saline (control) and experimental individuals treated with escitalopram (at single dose 5mg/kg daily), and clonazepam (at single dose 0.5mg/kg). All individuals were sacrificed under anaesthesia and the whole brain excised. Total mRNA was isolated from homogenized samples of amygdala, hippocampus, hypothalamus, thalamus, cerebellum and brainstem. Real time-PCR method was used for estimation of related NPS, NPS receptor (NPSR), NMU, NMU and receptor 2 (NMUR2) mRNA expression. The whole brains were also sliced for general immunohistochemical assessment of the neuropeptides expression. Chronic administration of clonazepam resulted in an increase of NMU mRNA expression and formation of NMU-expressing fibers in the amygdala, while escitalopram produced a significant decrease in NPSR mRNA level in hypothalamus. Long-term escitalopram administration affects the local expression of examined neuropeptides mRNA in a varied manner depending on the brain structure. Pharmacological effects of escitalopram may be connected with local at least partially NPSR-related alterations in the NPS/NMU/NMUR2 gene expression at the level selected rat brain regions. A novel alternative mode of SSRI action can be therefore cautiously proposed.

Neurotransmitters receptors gene drive the olfactory learning behavior of honeybee

The neurotransmitters receptor gene are multifunctional modulators of behaviors in social insects, with significant effects among species and several dominant roles within the same species. Multiple amines receptors affect diverse behavioral and physiological processes in the honeybee. Apis mellifera ligustica is excellent bee species due to its remarkable learning abilities. Here we analyze whether changes in expression of neurotransmitters receptor genes are related to olfaction learning behavior. We present a behavioral experiment on honeybees’ appetitive olfactory conditioning and examine the relationship between learning success and neurotransmitters receptor gene expression. Bees were trained using proboscis extension response to discriminate learner and failed learner bees and examine the expression of neurotransmitters receptors genes in the brains of learner and failed-learner bees. Real-time quantitative PCR was performed to assess neurotransmitter expression levels. Our finding showed significant results in differentiating the learner and failed-learner bee. The expression level of AmDop1, AmDop2, AmDop3, AmOa1, AmTyr1 and 5-HT showed significantly higher expression in learner and failed-learner bees. Our finding suggests the critical role of neurotransmitters receptors in the olfactory learning behavior of A. mellifera. These significant neurotransmitters receptors could thus act together to define optimal motivational or attentional levels and improve learning success. This study revealed the dynamic modulation of neurotransmitters expression in the brain of learner and failed learner bees and suggested an essential role for neurotransmitters receptors gene in regulating the olfactory learning behavior in honeybees. We suggested that neurotransmitters receptors are expressed in the brain of bees and are likely to be directly influential in regulating olfactory learning success in honeybees.

Proteomics analysis reveals a critical role for the WSSV immediate-early protein IE1 in modulating the host prophenoloxidase system

ABSTRACT White spot syndrome virus (WSSV) is a large, enveloped, double-stranded DNA virus that threatens shrimp aquaculture worldwide. So far, the mechanisms of WSSV-host interactions are ill-defined. Recent studies have revealed that IE1, an immediate-early protein of WSSV, is a multifunctional modulator implicated in virus–host interactions. In this study, the functions of IE1 were further explored by identifying its interacting proteins using GST-pull down and mass spectrometry analysis. A total of 361 host proteins that potentially bind to IE1 were identified. Bioinformatics analysis revealed that the identified IE1-interactors wereinvolved in various signaling pathways such as prophenoloxidase (proPO) system, PI3K-AKT, and MAPK. Among these, the regulatory role of IE1 in shrimp proPO system was further studied. The Co-immunoprecipitation results confirmed that IE1 interacted with the Ig-like domain of Penaeus vannamei proPO or proPO-like protein (hemocyanin). Additionally, we found that knockdown of IE1 reduced viral genes expression and viral loads and increased the hemocytes’ PO activity, whereas recombinant IE1 protein inhibited the PO activity in a dose-dependent manner. Finally, we demonstrated that WSSV could suppress the hemocytes’ PO activity at the early infection stage. Collectively, our current data indicate that IE1 is a novel viral regulator that negatively modulates the shrimp proPO system.

A multifunctional piperidine-based modulator for printable mesoscopic perovskite solar cells

Printable mesoscopic perovskite solar cells (PSCs) have received extensive attention due to their convenient large-area fabrication and good stability. The further improvement of the power conversion efficiency (PCE) of such simplified PSC configuration is limited by the low open circuit voltage (VOC). The high density of defects at grain boundaries of perovskites inside the mesoporous scaffold can cause severe nonradiative recombination, which have negative effects on VOC. Additive engineering has demonstrated advantages in improving the perovskite crystallization inside the pores, passivating the defects of perovskite and enhancing the performance of printable mesoscopic PSCs. Herein, we introduce a multifunctional modulator 1-(2-Chloroethyl) piperidine hydrochloride (ClEP) as an additive into the perovskite precursor solution. Benefiting from the strong interaction between ClEP and perovskite, it can interact with non-coordinating ions and defect states to achieve multi-defect passivation. As a result, the VOC of the printable mesoscopic PSC increases from 895.25 mV to 982.24 mV and the ClEP-treated printable mesoscopic PSC reaches a champion PCE of 17.08%. This work provides a new approach for developing efficient printable mesoscopic PSCs.

Simultaneous bottom-up double-layer synergistic optimization by multifunctional fused-ring acceptor with electron-deficient core for stable planar perovskite solar cells with approaching 24% efficiency

The interface defects and energy barrier between perovskite and electron transport layer (ETL) severely hinder the further improvement of the efficiency and stability of the perovskite solar cells (PSCs). Therefore, there is an urgent desire to develop multifunctional interface modulators to manage the interface between perovskite and ETL. Here, a multifunctional bottom-up double-layer interface modulation strategy is developed, that is, 2,2′-[[12,13-Bis(2-butyloctyl)− 12,13-dihydro-3,9-dinonylbisthieno[2'',3'':4′,5′]thieno[2′,3′:4,5]pyrrolo[3,2-e:2′,3′-g][2,1,3]benzothiadiazole-2,10-diyl]bis[methylidyne(5,6-chloro-3-oxo-1 H-indene-2,1(3 H)-diylidene)]]bis[propanedinitrile] (BTP-eC9) is combined in the SnO2/perovskite interface to achieve high efficiency and outstanding stability of PSCs. The BTP-eC9 can effectively prevent the detrimental contact between the FTO and perovskite and construct two electron transport paths by formatting the cascade energy level structure, which can eliminate the probability of carrier recombination and improve the interfacial carrier transfer. Chemically, BTP-eC9 can not only passivate the uncoordinated Sn ions, showing high conductivity and large photo-generated carrier transmission efficiency, but also can effectively passivate the underlying perovskite defects through a spontaneous bottom-up passivation process and improve the nucleation and crystallization kinetics of perovskite films. Based on the above efficient synergy, the power conversion efficiency (PCE) of up to 23.10% was obtained and it retains 90% of its original PCE after 8000 h in the ambient atmosphere without any encapsulation by the two-step method. In addition, the champion PCE of 23.75% with ultrahigh open-circuit voltage (VOC) of 1.25 V was achieved by the one-step method and this VOC is the highest value of a perovskite film with a band gap of approximately 1.60 eV, demonstrating the effectiveness and universality of this strategy. This research guides design methods of the ETL to raise the PCE of PSCs by interfacial engineering.

Multidimensional manipulation of broadband absorption with dual-controlled terahertz metamaterial absorbers

In this paper, we develop a dual-controlled graphene plasmon-based broadband metamaterial absorber (BMMA) integrating the photosensitive silicon. The designed device can implement active frequency, intensity, and bandwidth modulations of broadband absorption by electrically doping graphene and optically pumping silicon individually or simultaneously, featuring terahertz devices with multidimensional manipulation. To interpret the modulation mechanism of the broadband absorption, an equivalent circuit model based on the transmission line theory is constructed, and theorical results agree well with the simulated ones. In addition, the absorption characteristics depending on polarization angles, incident angles, and structural parameters are also systematically investigated. Therefore, the proposed broadband metamaterial absorber with multidimensional tunability endowed by dual-controlled mode could have potential applications on the design of active and multifunctional terahertz metadevices, such attenuators, modulators, selectors, and detectors.

Passivating buried interface with multifunctional novel ionic liquid containing simultaneously fluorinated anion and cation yielding stable perovskite solar cells over 23% efficiency

Interfacial defects and energy barrier would result in serious interfacial non-radiative recombination losses. In addition, the quality of perovskite films is highly dependent on deposition substrates. Consequently, there is an urgent desire to develop multifunctional interface modulators to manage the interface between electron transport layer and perovskite layer. Here, we report a multifunctional buried interface modulation strategy that 4-fluoro-phenylammonium tetrafluoroborate (FBABF4) consisting of simultaneously fluorinated anion and cation is inserted between SnO2 layer and perovskite layer. It is uncovered by time-of-flight secondary ion mass spectroscopy that the anion and cation in modifier are mainly located at this interface, which is put down to coordination bond of the fluorine atom on BF4− with SnO2, and the hydrogen bond of the fluorine atom on FBA+ with formamidinium. This suggests that simultaneous fluorination of anion and cation in the ionic liquid molecule is of crucial importance to ameliorate interfacial contact through chemical linker. The interface modification approach enables the realization of interfacial defect passivation, interfacial energy band alignment modulation, and perovskite crystallization manipulation, which are translated into enhanced efficiency and stability as well as significantly suppressed hysteresis. The multiple functions of FBABF4 endow the modified solar cells excellent photovoltaic performance with an efficiency exceeding 23% along with appealing long-term stability. This work highlights the critical role of fluorination strategy in engineering multifunctional organic salt modulators for improving interfacial contact.

IQM-PC332, a Novel DREAM Ligand with Antinociceptive Effect on Peripheral Nerve Injury-Induced Pain.

Neuropathic pain is a form of chronic pain arising from damage of the neural cells that sense, transmit or process sensory information. Given its growing prevalence and common refractoriness to conventional analgesics, the development of new drugs with pain relief effects constitutes a prominent clinical need. In this respect, drugs that reduce activity of sensory neurons by modulating ion channels hold the promise to become effective analgesics. Here, we evaluated the mechanical antinociceptive effect of IQM-PC332, a novel ligand of the multifunctional protein downstream regulatory element antagonist modulator (DREAM) in rats subjected to chronic constriction injury of the sciatic nerve as a model of neuropathic pain. IQM-PC332 administered by intraplantar (0.01–10 µg) or intraperitoneal (0.02–1 µg/kg) injection reduced mechanical sensitivity by ≈100% of the maximum possible effect, with ED50 of 0.27 ± 0.05 µg and 0.09 ± 0.01 µg/kg, respectively. Perforated-patch whole-cell recordings in isolated dorsal root ganglion (DRG) neurons showed that IQM-PC332 (1 and 10 µM) reduced ionic currents through voltage-gated K+ channels responsible for A-type potassium currents, low, T-type, and high voltage-activated Ca2+ channels, and transient receptor potential vanilloid-1 (TRPV1) channels. Furthermore, IQM-PC332 (1 µM) reduced electrically evoked action potentials in DRG neurons from neuropathic animals. It is suggested that by modulating multiple DREAM–ion channel signaling complexes, IQM-PC332 may serve a lead compound of novel multimodal analgesics.

The Multifunctional Faces of T-Cell Intracellular Antigen 1 in Health and Disease.

T-cell intracellular antigen 1 (TIA1) is an RNA-binding protein that is expressed in many tissues and in the vast majority of species, although it was first discovered as a component of human cytotoxic T lymphocytes. TIA1 has a dual localization in the nucleus and cytoplasm, where it plays an important role as a regulator of gene-expression flux. As a multifunctional master modulator, TIA1 controls biological processes relevant to the physiological functioning of the organism and the development and/or progression of several human pathologies. This review summarizes our current knowledge of the molecular aspects and cellular processes involving TIA1, with relevance for human pathophysiology.

Improved performance and stability of perovskite solar modules by interface modulating with graphene oxide crosslinked CsPbBr3 quantum dots

A multifunctional interface modulator GO/(CsPbBr3 QD) composite decreases resistive losses of perovskite solar modules by enhanced charge transport and decreased carrier recombination, as well as inhibiting ion/molecule diffusion.

Novel X gene point mutations in chronic hepatitis B and HBV related cirrhotic patients.

HBx is a multifunctional modulator viral protein with key roles in various biological processes such as signal transduction, transcription, proliferation, and cell apoptosis. Also, HBx has an important role in the progression of cirrhosis and hepatocellular carcinoma (HCC). This study aimed to determine mutations in X gene, enhancer II (EnhII), and basal core promoter (BCP) of genotype D of Hepatitis B Virus (HBV) in cirrhotic and chronic HBV patients. This cross-sectional study was performed on 68 cases with chronic HBV (cHBV) and 50 cases with HBV related cirrhosis. Serum samples were obtained for genomic DNA extraction. Semi-nested PCR was used to amplify the HBx region. Point mutations in the HBx region were detected by sequencing. Novel mutations were detected, including C1491G, C1500T, G1613T, and G1658T in the N-terminal of the X gene. The frequency of C1481T/G1479A, T1498C, C1500T, G1512A, A1635T, C1678T, A1727T, and A1762T/ G1764A/ C1773T was significantly higher in cirrhotic patients compared to chronically HBV infected ones. A higher rate of A1635T, C1678T, A1727T, A1762T, G1764A, and C1773T was observed in cirrhotic patients. Our findings showed that the frequency of mutations in the basal-core promoter, enhancer II, and regulatory region of the HBx gene was more seen in cirrhotic patients than in chronic HBV cases. Novel mutations were detected in the HBx gene, causing amino acid substitutions; however, the clinical impact of these novel mutations is yet to be cleared.

Multifunctional molecules with a bipyridyl core ameliorate multifaceted amyloid toxicity

A series of 2,2'-bipyridine derivatives appended with structurally unique biomolecular auxiliaries were synthesized and investigated for their ability to ameliorate multifaceted amyloid toxicity. Our results highlight the roles of the metal-chelating bipyridine core and functional auxiliaries in effectively modulating metal-independent and -dependent amyloid toxicity, and oxidative stress observed in Alzheimer's disease (AD).

Multipronged diagnostic and therapeutic strategies for Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder and a major contributor to dementia cases worldwide. AD is clinically characterized by learning, memory, and cognitive deficits. The accumulation of extracellular amyloid β (Aβ) plaques and neurofibrillary tangles (NFTs) of tau are the pathological hallmarks of AD and are explored as targets for clinical diagnosis and therapy. AD pathology is poorly understood and there are no fully approved diagnosis and treatments. Notwithstanding the gap, decades of research in understanding disease mechanisms have revealed the multifactorial nature of AD. As a result, multipronged and holistic approaches are pertinent to targeting multiple biomarkers and targets for developing effective diagnosis and therapeutics. In this perspective, recent developments in Aβ and tau targeted diagnostic and therapeutic tools are discussed. Novel indirect, combination, and circulating biomarkers as potential diagnostic targets are highlighted. We underline the importance of multiplexing and multimodal detection of multiple biomarkers to generate biomarker fingerprints as a reliable diagnostic strategy. The classical therapeutics targeting Aβ and tau aggregation pathways are described with bottlenecks in the strategy. Drug discovery efforts targeting multifaceted toxicity involving protein aggregation, metal toxicity, oxidative stress, mitochondrial damage, and neuroinflammation are highlighted. Recent efforts focused on multipronged strategies to rationally design multifunctional modulators targeting multiple pathological factors are presented as future drug development strategies to discover potential therapeutics for AD.

Bio-Inspired Microwave Modulator for High-Temperature Electromagnetic Protection, Infrared Stealth and Operating Temperature Monitoring

HighlightsA multifunctional microwave modulator is developed for electromagnetic protection, infrared stealth and operating temperature monitoring over wide temperature ranges for the first time.Microwave modulator achieves the integration of two electromagnetic protection mechanisms, microwave absorption and radiation deflection.Microwave modulator demonstrates the maximum effective bandwidth of 5.2 GHz with a thickness of only 1.5 mm in the temperature range 298–673 K.