251 research outputs found

    Non-left-handed transmission and bianisotropic effect in a [pi]-shaped metallic metamaterials

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    A [pi]-shaped metallic metamaterial (geometrically, a combination medium of C-shaped resonators and continuous wires) is proposed to numerically investigate its transmission band near the resonant frequency, where otherwise it should be a negative-permeability (or negative-permittivity) stop band if either the C-shaped or continuous-wire constituent is separately considered. However, in contrast to the left-handed materials (LHMs)composed of split-ring resonators and wires as well as other metallic LHMs, this resonant transmission is a non-left-handed one as a result of the intrinsic bianisotropic effect attributed to the electrically asymmetric configuration of this [pi]-shaped metamaterial.Comment: 19 pages, 6 figure

    Human Pluripotent Stem Cell-Derived Mesenchymal Stem Cells for Oncotherapy

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    Mesenchymal stem/stromal cells (MSCs) with hematopoietic-supporting and immunoregulatory properties have aroused great expectations in the field of regenerative medicine and the concomitant pathogenesis. However, many obstacles still remain before the large-scale preparation of homogeneous and standardized MSCs with high cellular vitality for clinical purposes ascribe to elusive nature and biofunction of MSCs derived from various adult and fetal sources. Current progress in human pluripotent stem cells (hPSCs), including embryonic stem cells (ESCs) and induced PSCs (iPSCs), have highlighted the feasibility of MSC development and disease remodeling, together with robust MSC generation dispense from the inherent disadvantages of the aforementioned MSCs including ethical and pathogenic risks, donor heterogeneity and invasiveness. Herein, we review the state-of-the-art updates of advances for MSC preparation from hPSCs and multiple tissues (perinatal tissue, adult tissue) as well as tumor intervention with biomaterials, and thus propose a framework for MSCs-based oncotherapy in regenerative medicine. Collectively, we describe the landscape of in vitro generation and functional hierarchical organization of hPSC-MSCs, which will supply overwhelming new references for further dissecting MSC-based tissue engineering and disease remodeling

    Strategies to improve the therapeutic efficacy of mesenchymal stem cell‐derived extracellular vesicle (MSC-EV): a promising cell-free therapy for liver disease

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    Liver disease has emerged as a significant worldwide health challenge due to its diverse causative factors and therapeutic complexities. The majority of liver diseases ultimately progress to end-stage liver disease and liver transplantation remains the only effective therapy with the limitations of donor organ shortage, lifelong immunosuppressants and expensive treatment costs. Numerous pre-clinical studies have revealed that extracellular vesicles released by mesenchymal stem cells (MSC-EV) exhibited considerable potential in treating liver diseases. Although natural MSC-EV has many potential advantages, some characteristics of MSC-EV, such as heterogeneity, uneven therapeutic effect, and rapid clearance in vivo constrain its clinical translation. In recent years, researchers have explored plenty of ways to improve the therapeutic efficacy and rotation rate of MSC-EV in the treatment of liver disease. In this review, we summarized current strategies to enhance the therapeutic potency of MSC-EV, mainly including optimization culture conditions in MSC or modifications of MSC-EV, aiming to facilitate the development and clinical application of MSC-EV in treating liver disease

    Fibrosis progression in interferon treatment-naive Chinese plasma donors with chronic hepatitis C for 20 years: a cohort study

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    SummaryObjectivesTo evaluate the progression of fibrosis and factors influencing this in interferon (IFN) treatment-naive Chinese plasma donors infected with hepatitis C virus (HCV) for approximately 20 years.MethodsFrom July 2010 to June 2011, we investigated 122 IFN treatment-naive chronic hepatitis C (CHC) patients infected by plasma donation in 1992–1995. Liver fibrosis stage and inflammation grade were evaluated by Metavir and Scheuer scoring systems, respectively.ResultsOne hundred and twenty patients underwent liver biopsy. Liver biopsy was not performed in one patient with cirrhosis due to ascites, and another patient was excluded because of an invalid biopsy specimen. Cirrhosis was observed in three patients (fibrosis stage F4 in two patients revealed by biopsy, and one patient with ascites confirmed by physical and Doppler ultrasound examination). Fibrosis stages F1 and F2 were present in 55 and 50 patients, respectively. The severity of liver inflammation was independently related to moderate to severe fibrosis (F ≥2). Older age and male sex showed an increasing tendency for more severe fibrosis (F3/F4) in the present cohort.ConclusionsBased on histopathology results, the progression of fibrosis in patients with CHC infected by repeated plasma donation is slow after HCV infection of approximately 20 years. Liver inflammation is closely related to the development of moderate to severe liver fibrosis

    Calcium-sensing receptors regulate cardiomyocyte Ca2+ signaling via the sarcoplasmic reticulum-mitochondrion interface during hypoxia/reoxygenation

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    Communication between the SR (sarcoplasmic reticulum, SR) and mitochondria is important for cell survival and apoptosis. The SR supplies Ca2+ directly to mitochondria via inositol 1,4,5-trisphosphate receptors (IP3Rs) at close contacts between the two organelles referred to as mitochondrion-associated ER membrane (MAM). Although it has been demonstrated that CaR (calcium sensing receptor) activation is involved in intracellular calcium overload during hypoxia/reoxygenation (H/Re), the role of CaR activation in the cardiomyocyte apoptotic pathway remains unclear. We postulated that CaR activation plays a role in the regulation of SR-mitochondrial inter-organelle Ca2+ signaling, causing apoptosis during H/Re. To investigate the above hypothesis, cultured cardiomyocytes were subjected to H/Re. We examined the distribution of IP3Rs in cardiomyocytes via immunofluorescence and Western blotting and found that type 3 IP3Rs were located in the SR. [Ca2+]i, [Ca2+]m and [Ca2+]SR were determined using Fluo-4, x-rhod-1 and Fluo 5N, respectively, and the mitochondrial membrane potential was detected with JC-1 during reoxygenation using laser confocal microscopy. We found that activation of CaR reduced [Ca2+]SR, increased [Ca2+]i and [Ca2+]m and decreased the mitochondrial membrane potential during reoxygenation. We found that the activation of CaR caused the cleavage of BAP31, thus generating the pro-apoptotic p20 fragment, which induced the release of cytochrome c from mitochondria and the translocation of bak/bax to mitochondria. Taken together, these results reveal that CaR activation causes Ca2+ release from the SR into the mitochondria through IP3Rs and induces cardiomyocyte apoptosis during hypoxia/reoxygenation

    Manipulating spatial structure of high-order quantum coherence with entangled photons

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    High-order quantum coherence reveals the statistical correlation of quantum particles. Manipulation of quantum coherence of light in temporal domain enables to produce single-photon source, which has become one of the most important quantum resources. High-order quantum coherence in spatial domain plays a crucial role in a variety of applications, such as quantum imaging, holography and microscopy. However, the active control of high-order spatial quantum coherence remains a challenging task. Here we predict theoretically and demonstrate experimentally the first active manipulation of high-order spatial quantum coherence by mapping the entanglement of spatially structured photons. Our results not only enable to inject new strength into current applications, but also provide new possibilities towards more wide applications of high-order quantum coherence.Comment: 11 pages, 5 figure

    Solid-state microscale lithium batteries prepared with microfabrication processes

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    The miniaturization of power sources is important for meeting the requirements of low power, mass and volume for nano- or microelectronics and MEMS devices. In this paper a dexterous microfabrication process was developed for preparing microscale solid-state lithium batteries. The active size of a single microbattery is 500 mu m x 500 mu m and its thickness is 1.5 mu m. LiCoO2 films prepared by RF sputtering, then annealed at moderate temperature (500 degrees C), were employed as a cathode electrode, and LiPON and Al films were used as a solid electrolyte and an anode electrode, respectively. An individual microbattery delivers a capacity of about 17 nAh at a current of 5 nA at the initial cycles, and can be operated at as high as 40 nA discharge current.National 973 Program [2009CB220102]; National Defence [XMDX2008176]; Fujian province [2006H0090
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