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The morphology regulation and plasmonic spectral properties of Au@AuAg yolk-shell nanorods with controlled interior gap
摘要： Au@AuAg yolk-shell nanorods with tunable and uniform interior gap were synthesized through galvanic replacement reaction, where Au@Ag core-shell nanorods served as sacrificial templates and HAuCl4 solution served as reductant. The effects of HAuCl4, Ag shell thickness and aspect ratio (AR) of Au nanorods on the morphology of Au@AuAg yolk-shell nanorods had been investigated systemically. The results clearly indicated that AuAg alloy shell thickness of Au@AuAg yolk-shell nanorods could be increased from 3.6 to 10.0 nm by varying the amount of HAuCl4. Meanwhile, the shape of AuAg alloy shell could be tuned by changing the shape of Ag coating. With the increasing of Ag coating thickness, the interior gap could be finely tuned in the range from 2.6 to 8.1 nm. The uniformity of interior gap could be improved by increasing the AR of Au nanorods. All these tunable geometries can further affect the plasmonic spectral properties of Au@AuAg yolk-shell nanorods. Because of the appearance of interior gap, the longitudinal localized surface plasmon resonance (LSPR) peak of Au@AuAg yolk-shell nanorods was located between that of bare Au nanorods and Au@Ag core-shell nanorods without interior gap. The increase of outer AuAg shell thickness can weaken the coupling between the inner and outer surface of the AuAg shell and lead to the decrease of AR, so the transverse and longitudinal LSPR bands gather together. The decrease of Ag coating thickness can enhance the coupling between inner Au nanorod and outer AuAg shell, which results in the red shift of the longitudinal LSPR band. This paper provides a method for studying the plasmonic coupling between two metal surfaces with a metal layer or a dielectric layer, which is also a new approach for regulating the plasmonic spectral properties of bimetallic nanoparticles. The controllability of Au@AuAg yolk-shell nanorods in both the interior gap and outer alloy shells makes them have potential applications in biomedicine, catalysis, nanoreactors, and energy storage.
关键词： interior gap,localized surface plasmon resonance,spectral properties,morphology regulation,Au@AuAg yolk-shell nanorods
更新于2025-09-23 15:21:01
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Conjugated Polymer Nanoparticles for Imaging, Cell Activity Regulation, and Therapy
摘要： Conjugated polymer nanoparticles, considered as a class of promising nanomaterials for biomedical application, are extensively employed in bioimaging, anti-microorganism and antitumor, gene and drug delivery/release in the past decade. By virtue of unique photoelectric properties, such as strong light absorbing quality, high brightness, good photostability, tunable spectra property, and favorable compatibility, conjugated polymer nanoparticles attract increasing attention and are used in more emerging aspects in biological and biomedical fields. This review summarizes the recent (2014–2018) development of conjugated polymer nanoparticles, including design, synthesis, and biomedical applications. Especially, their abilities of bioimaging, cell activity regulation, anti-microorganism and antitumor therapy are discussed in detail. Finally, the challenges and outlooks in the field are highlighted.
关键词： cell activity regulation,phototherapy,Conjugated polymer nanoparticles,bioimaging
更新于2025-09-23 15:21:01
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Stress Physiology of Tea in the Face of Climate Change || UV-B Radiation-Induced Changes in Tea Metabolites and Related Gene Expression
摘要： UV-B radiation is an inevitable abiotic stress, which could induce a series of changes in metabolites and related metabolisms in plants. UV-B-induced metabolic changes in leaves of Camellia sinensis affect the tea quality. This review summarizes the recent investigations into UV-B radiation-induced changes in tea metabolites and their related gene expression, involving in flavonoids, amino acids, and volatile compounds. UV-B radiation induces flavonoid accumulation by increasing expression of key genes in general phenylpropanoid pathway and flavonoid pathway. The UV-B radiation-induced gene expressions in flavonoid biosynthesis pathway also are affected by transcription factors and endogenous phytohormones signaling pathway. Changes of individual amino acids under UV-B radiation exhibit significant variation among different plants, and their responses to UV-B radiation dose are different. These regulations involve in modulation of gene expressions related to GABA shunt and tricarboxylic acid cycle (TCA). Volatile compounds in Camellia sinensis under UV-B radiation are regulated by both metabolites biosynthesis and volatile glycosidic-precursors hydrolysis. In a word, UV-B radiation influences metabolisms in tea in a rather complex way. More researches on UV-B-induced transcriptional regulation, endogenous-phytohormone signal regulation, metabolisms diversions regulation, etc. are needed in the future.
关键词： Gene expression,Signal regulation,Amino acids,Volatile compounds,Tea polyphenols,UV-B radiation
更新于2025-09-23 15:21:01
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[IEEE 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz2018) - Nagoya, Japan (2018.9.9-2018.9.14)] 2018 43rd International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Turning THz Communications into Reality: Status on Technology, Standardization and Regulation
摘要： Already a couple of years ago THz communications have not only become an attractive new research area on channel modeling but also triggered a couple of projects heading to develop appropriate technological solutions to enable the set-up of hardware demonstrators. Also discussions and activities in standardization and regulation already took off. In October 2017, IEEE published Std. IEEE 802.15.3d-2017 the worldwide first wireless communications standard operating in the 300 GHz frequency band. In parallel to the standardization process activities at the ITU-R level targeting on the provision of an appropriate regulatory framework at the World Radio Conference 2019 (WRC-2019) via a dedicated agenda item have taken off. This paper provides a brief overview on the current status of the development of THz Communication systems focusing on recent results on advanced channel characterization at 300 GHz, hardware demonstrators operating in this frequency range, the past and current activities at IEEE 802 and the WRC 2019 preparations.
关键词： channel modeling,standardization,THz communications,regulation,hardware demonstrators
更新于2025-09-23 15:21:01
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[IEEE 2019 IEEE International Conference on Mechatronics and Automation (ICMA) - Tianjin, China (2019.8.4-2019.8.7)] 2019 IEEE International Conference on Mechatronics and Automation (ICMA) - Stability Control of Intermediate Frequency for A Double Cavity HCN Laser
摘要： Proponents of deploying LTE in the 5 GHz band for providing additional cellular network capacity have claimed that LTE would be a better neighbour to Wi-Fi in the unlicensed band, than Wi-Fi is to itself. On the other side of the debate, the Wi-Fi community has objected that LTE would be highly detrimental to Wi-Fi network performance. However, there is a lack of transparent and systematic engineering evidence supporting the contradicting claims of the two camps, which is essential for ascertaining whether regulatory intervention is in fact required to protect the Wi-Fi incumbent from the new LTE entrant. To this end, we present a comprehensive coexistence study of Wi-Fi and LTE-in-unlicensed, surveying a large parameter space of coexistence mechanisms and a range of representative network densities and deployment scenarios. Our results show that, typically, harmonious coexistence between Wi-Fi and LTE is ensured by the large number of 5 GHz channels. For the worst-case scenario of forced co-channel operation, LTE is sometimes a better neighbour to Wi-Fi—when effective node density is low—but sometimes worse—when density is high. We ?nd that distributed interference coordination is only necessary to prevent a ‘‘tragedy of the commons’’ in regimes where interference is very likely. We also show that in practice it does not make a difference to the incumbent what kind of coexistence mechanism is added to LTE-in-unlicensed, as long as one is in place. We therefore conclude that LTE is neither friend nor foe to Wi-Fi in the unlicensed bands in g(cid:101)n(cid:101)ral. We submit that the systematic engineering analysis exemplified by our case study is a best-practice approach for supporting evidence-based rulemaking by the regulator.
关键词： LTE,spectrum regulation,coexistence,Wi-Fi,IEEE 802.11,unlicensed
更新于2025-09-23 15:19:57
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Microcirculatory Response to Photobiomodulationa??Why Some Respond and Others Do Not: A Randomized Controlled Study
摘要： Photobiomodulation (PBM), a non‐ionizing, non‐thermal irradiation, used clinically to accelerate wound healing and inhibit pain, was previously shown to increase blood flow. However, some individuals respond to PBM, but others do not. The purpose of this study was to investigate factors affecting this patient‐specific response using advanced, noninvasive methods for monitoring microcirculatory activity. In this prospective, randomized controlled trial (NCT03357523), 20 healthy non‐smoking volunteers (10:10 males:females, 30 ± 8 years old) were randomized to receive either red‐ (633 nm and 70 W/cm2) or near‐infrared light (830 nm and 55 mW/cm2) over the wrist for 5 minutes. Photoplethysmography, laser Doppler flowmetry, and thermal imaging were used to monitor palm microcirculatory blood volume, blood flow, and skin temperature, respectively, before, during, and 20 minutes after irradiation. Participants with skin temperature change ≥0.5°C from baseline were considered “responders”. Near‐infrared PBM was found to induce a 27% increase in microcirculatory flow that increased to 54% during the 20‐minute follow‐up period (P = 0.049 and P = 0.004, respectively), but red light PBM did not increase the median flow. Only 10 of 20 participants were responders by thermal imaging (i.e., ≥0.5°C from baseline), and their initial skin temperature was between 33 and 37.5°C. The non‐responders had either “hot” hands (≥37.5°C) or “cold” hands (≤33°C). In responders, the meantime to 20% increase in microcirculatory blood volume and blood flow was less than 2.5 minutes after initiation of PBM irradiation. We demonstrated that PBM induces arteriolar vasodilatation that results in both immediate and long‐lasting increased capillary flow and tissue perfusion in healthy individuals. This response was wavelength‐dependent and modified by skin temperature. These findings regarding physiological parameters associated with sensitivity or resistance to PBM provide information of direct relevance for patient‐specific therapy.
关键词： body temperature regulation,laser‐Doppler flowmetry,microcirculation,low‐level laser therapy,vasodilation,thermal imaging,photoplethysmography
更新于2025-09-23 15:19:57
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Achieving the hypsochromic electroluminescence of ultraviolet OLED by tuning excitons relaxation
摘要： Organic light emitting diode (OLED) has huge impact on display-related fields. Due to potential applications in information storage and backlight sources for full color display, ultraviolet OLED has attracted widespread attention. In this paper, we present an inverted UV OLED device with electroluminescence (EL) peak of 369 nm. The device employs zinc oxide (ZnO) as electron injection layer (EIL), revealing a relationship between the exciton diffusion and emitting peaks. The organic-inorganic interface in the device reduces the diffusion length of excitons and that can lead to a hampered relaxation of higher energy states, resulting in a hypsochromic shift of the EL spectrum. The existence of buffer layer will affect the relaxation process. Additionally, the emission peak of the UV-OLED can be adjusted from 369 nm to 384 nm by varying kinds and thickness of the organic functional layers.
关键词： Hypsochromic shift,OLED,Exciton relaxation,Ultraviolet emission,Wavelength regulation,Diffusion model
更新于2025-09-23 15:19:57
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3-Phase grid-connected building integrated photovoltaic system with reactive power control capability
摘要： Recently, a tendency in the growing of grid-connected building integrated photovoltaic (BIPV) systems has been noticed in most countries. Hence, high penetration of PV power into the system network can be observed in many points in the network. This may cause severe problems on the distribution network due to the intermittent nature of PV systems. As a feasible solution, the reactive power capability of voltage source inverter in PV systems can be employed rather than approaching expensive grid infrastructures in the distribution network. The purpose of this study is to implement a 3-phase grid-connected (BIPV) system with reactive power control to regulate the system voltage and improve the system power factor. Subsequent to this, a specific system model has been designed and developed in MATLAB Simulink application. The selection of PV system specifications is based on practical system implementation. The inverter control system along with the reactive power control has been developed for the proper system operation at different system conditions to reduce the var compensation on the utility grid. Better system accuracy of the developed system model has been found by validating with real system data. The overall system performance has indicated that the effective utilization of reactive power control of a grid-connected PV system yields to a stable, reliable and cost-effective system network operation which reduces the heavy burden on the utility grid to control the PV system effects.
关键词： Reactive power control,Voltage source inverter,Grid-connected PV system,Voltage regulation
更新于2025-09-23 15:19:57
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Indoor and outdoor characterization of concentrating photovoltaic attached to multi-layered microchannel heat sink
摘要： Concentrating Photovoltaic technology is a promising option in power generation using the photovoltaics compared to the conventional ?at PV system. This study investigates the performance of a high concentrated photovoltaic single solar cell module attached to a multi-layered microchannel heat sink. The system has been tested the ?rst time experimentally both at indoor and outdoor conditions. The indoor characterization of the system investigated the e?ect of varying the number of the layers of the heat sink and the ?ow rate of the ?uid electrically and thermally. The experiments show that varying the number of the heat sink layers from 1-layer to 3-layers increase the maximum electrical generation by 10% and reduces the cell temperature by 3.15 °C under the same ?uid ?ow rate of 30 ml/min. The outdoor experiments show the maximum output electrical generation of the system of 4.60 W and the short circuit current of 1.96 A. The maximum solar cell temperature was maintained below 61 °C where the extracted heat of the system was 12.85 W which represents of 74.9% of the total generated power.
关键词： Heat sink,Concentrating photovoltaic,Thermal regulation,Multi-layered microchannel
更新于2025-09-23 15:19:57
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A Circulating MicroRNA Profile in a Laser-Induced Mouse Model of Choroidal Neovascularization
摘要： Choroidal neovascularization (CNV) is a pathological process in which aberrant blood vessels invade the subretinal space of the mammalian eye. It is a characteristic feature of the prevalent neovascular age-related macular degeneration (nAMD). Circulating microRNAs (cmiRNAs) are regarded as potentially valuable biomarkers for various age-related diseases, including nAMD. Here, we investigated cmiRNA expression in an established laser-induced CNV mouse model. Upon CNV induction in C57Bl/6 mice, blood-derived cmiRNAs were initially determined globally by RNA next generation sequencing, and the most strongly dysregulated cmiRNAs were independently replicated by quantitative reverse transcription PCR (RT-qPCR) in blood, retinal, and retinal pigment epithelium (RPE)/choroidal tissue. Our findings suggest that two miRNAs, mmu-mir-486a-5p and mmur-mir-92a-3p, are consistently dysregulated during CNV formation. Furthermore, in functional in vitro assays, a significant impact of mmu-mir-486a-5p and mmu-mir-92a-3p on murine microglial cell viability was observed, while mmu-mir-92a-3p also showed an impact on microglial mobility. Taken together, we report a robust dysregulation of two miRNAs in blood and RPE/choroid after laser-induced initiation of CNV lesions in mice, highlighting their potential role in pathology and eventual therapy of CNV-associated complications.
关键词： cmiRNA regulation,biomarker,laser-induced choroidal,neovascularization,age-related macular degeneration
更新于2025-09-23 15:19:57