99 research outputs found

    Engineering Moir\'e Meta-crystals with Conventional Photonic and Phononic Structures

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    Recent discoveries on Mott insulating and unconventional superconducting states in twisted bilayer graphene with Moir\'e superlattices have reshaped the landscape of ''twistronics'' and paved the way for developing high-temperature superconductors and new devices for quantum computing and sensing. Meanwhile, artificially structured photonic and phononic metamaterials/crystals (or meta-crystals) have become a fertile playground for emulating quantum-mechanical features of condensed matter systems, revealing new routes for robust control of classical waves. Drawing inspiration from the success of twisted bilayer graphene, this perspective casts an overarching framework of the emerging Moir\'e photonic and phononic meta-crystals that promise novel classical-wave devices. We begin with the fundamentals of Moir\'e superlattices, before highlighting recent works that exploit twist angle and interlayer coupling as new ingredients to engineer and tailor the band structures and effective material properties of photonic and phononic meta-crystals. We finally discuss future directions and promises of this emerging area in materials science and wave physics.Comment: 4 figure

    NMDA Receptors of Gastric-Projecting Neurons in the Dorsal Motor Nucleus of the Vagus Mediate the Regulation of Gastric Emptying by EA at Weishu (BL21)

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    A large number of studies have been conducted to explore the efficacy of electroacupuncture (EA) for the treatment of gastrointestinal motility. While several lines of evidence addressed the basic mechanism of EA on gastrointestinal motility regarding effects of limb and abdomen points, the mechanism for effects of the back points on gastric motility still remains unclear. Here we report that the NMDA receptor (NMDAR) antagonist kynurenic acid inhibited the gastric emptying increase induced by high-intensity EA at BL21 and agonist NMDA enhanced the effect of the same treatment. EA at BL21 enhanced NMDAR, but not AMPA receptor (AMPAR) component of miniature excitatory postsynaptic current (mEPSC) in gastric-projecting neurons of the dorsal motor nucleus of the vagus (DMV). In sum, our data demonstrate an important role of NMDAR-mediated synaptic transmission of gastric-projecting DMV neurons in mediating EA at BL21-induced enhancement of gastric emptying

    Large extraordinary Hall effect in [Pt/Co]5/Ru/[Co/Pt]5 multilayer

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    This Brief Report presents giant extraordinary Hall effect (EHE) in the Ru-mediated antiferromagnetically coupled [Pt/Co]5/Ru/[Co/Pt]5 multilayers (MLs) compared with those MLs without the Ru spacer. The enhancement of the EHE is attributed to the strong Ru/Co interface scattering. Through the variation in the Pt layer thickness and the temperature, we determine the relation between the Hall voltage and the longitudinal resistivity. It is found that the conventional scaling analysis has difficulties in consistently interpreting our data

    Auricular Acupuncture and Vagal Regulation

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    Auricular acupuncture has been utilized in the treatment of diseases for thousands of years. Dr. Paul Nogier firstly originated the concept of an inverted fetus map on the external ear. In the present study, the relationship between the auricular acupuncture and the vagal regulation has been reviewed. It has been shown that auricular acupuncture plays a role in vagal activity of autonomic functions of cardiovascular, respiratory, and gastrointestinal systems. Mechanism studies suggested that afferent projections from especially the auricular branch of the vagus nerve (ABVN) to the nucleus of the solitary tract (NTS) form the anatomical basis for the vagal regulation of auricular acupuncture. Therefore, we proposed the “auriculovagal afferent pathway” (AVAP): both the autonomic and the central nervous system could be modified by auricular vagal stimulation via projections from the ABVN to the NTS. Auricular acupuncture is also proposed to prevent neurodegenerative diseases via vagal regulation. There is a controversy on the specificity and the efficacy of auricular acupoints for treating diseases. More clinical RCT trials on auricular acupuncture and experimental studies on the mechanism of auricular acupuncture should be further investigated

    Intravenous Laser Blood Irradiation, Interstitial Laser Acupuncture, and Electroacupuncture in an Animal Experimental Setting: Preliminary Results from Heart Rate Variability and Electrocorticographic Recordings

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    This is the first study to investigate intravenous (i.v.) laser blood irradiation, interstitial (i.st.) laser acupuncture, and electroacupuncture (EA) in combination with heart rate variability (HRV) and electrocorticogram. We investigated 10 male anesthetized Sprague-Dawley rats under the three conditions mentioned previously in Beijing, China, and data analysis was performed in Graz, Europe. For i.v. laser stimulation in the femoral vein and i.st. laser acupuncture at Neiguan (PC6), we used a European system (Modulas needle, Schwa-Medico, Germany; 658 nm, 50 mW, continuous wave mode), and for EA at Neiguan, a Chinese system (Hanshi-100A; Nanjing Jisheng Medical Technology Company, China; 15 Hz, 1 mA). HR, HRV, and electrocorticogram were recorded using a biophysical amplifier AVB-10 (Nihon-Kohden, Japan). HR changed significantly during i.st. laser acupuncture stimulation of Neiguan in anesthetized rats. Total HRV increased insignificantly during i.v. and i.st. laser stimulation. The LF/HF ratio showed significant changes only during i.v. laser blood irradiation. Integrated cortical EEG (electrocorticogram) decreased insignificantly during EA and i.v. laser blood irradiation. Further studies concerning dosage-dependent alterations are in progress

    Auricular Acupuncture and Vagal Regulation

    Get PDF
    Auricular acupuncture has been utilized in the treatment of diseases for thousands of years. Dr. Paul Nogier firstly originated the concept of an inverted fetus map on the external ear. In the present study, the relationship between the auricular acupuncture and the vagal regulation has been reviewed. It has been shown that auricular acupuncture plays a role in vagal activity of autonomic functions of cardiovascular, respiratory, and gastrointestinal systems. Mechanism studies suggested that afferent projections from especially the auricular branch of the vagus nerve (ABVN) to the nucleus of the solitary tract (NTS) form the anatomical basis for the vagal regulation of auricular acupuncture. Therefore, we proposed the "auriculovagal afferent pathway" (AVAP): both the autonomic and the central nervous system could be modified by auricular vagal stimulation via projections from the ABVN to the NTS. Auricular acupuncture is also proposed to prevent neurodegenerative diseases via vagal regulation. There is a controversy on the specificity and the efficacy of auricular acupoints for treating diseases. More clinical RCT trials on auricular acupuncture and experimental studies on the mechanism of auricular acupuncture should be further investigated

    Delivery of the Sox9 gene promotes chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells in an in vitro model

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    SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.publishedVersio

    Are Primo Vessels (PVs) on the Surface of Gastrointestine Involved in Regulation of Gastric Motility Induced by Stimulating Acupoints ST36 or CV12?

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    Previous studies showed primo vessels (PVs), which were referred to as Bonhan ducts (BHDs) and a part of circulatory system by Kim, located in different places of the body. The BHDs system was once considered as the anatomical basis of classical acupuncture meridian but not clearly identified by other investigators. In the present study, we tried to address the relationship between PVs and meridians through detecting the modulation of gastric motility by stimulating the PVs on the surface of stomach or intestine, as well as acupoints Zusanli (ST36) and Zhongwan (CV12). The results showed electric stimulation of the PVs had no effect on the gastric motility. While stimulating CV12 inhibited gastric motility significantly in PVs-intact and PVs-cut rats, there is no significant difference between the inhibition rate of the PVS-intact and the PVS-cut rats. Stimulating at ST36 increased gastric motility significantly in both the PVs-intact and the PVs-cut rats, yet there was no significant difference between the facilitation rate of the both groups. Taken together, the PVs on the surface of stomach or intestine did not mediate the regulation of gastric motility induced by stimulating at the acupoints ST36 or CV12
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