180 research outputs found

    The effects of the combination of mesenchymal stromal cells and nanofiber-hydrogel composite on repair of the contused spinal cord

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    A bone marrow-derived mesenchymal stromal cell (MSC) transplant and a bioengineered nanofiber-hydrogel composite (NHC) have been shown to stimulate nervous tissue repair in the contused spinal cord in rodent models. Here, these two modalities were combined to assess their repair effects in the contused spinal cord in adult rats. Cohorts of contused rats were treated with MSC in NHC (MSC-NHC), MSC in phosphate-buffered saline (MSC-PBS), NHC, or PBS injected into the contusion site at 3 days post-injury. One week after injury, there were significantly fewer CD68+ cells in the contusion with MSC-NHC and NHC, but not MSC-PBS. The reduction in CD86+ cells in the injury site with MSC-NHC was mainly attributed to NHC. One and eight weeks after injury, we found a greater CD206+/CD86+ cell ratio with MSC-NHC or NHC, but not MSC-PBS, indicating a shift from a pro-inflammatory towards an anti-inflammatory milieu in the injury site. Eight weeks after injury, the injury size was significantly reduced with MSC-NHC, NHC, and MSC-PBS. At this time, astrocyte, and axon presence in the injury site was greater with MSC-NHC compared with MSC-PBS. We did not find a significant effect of NHC on MSC transplant survival, and hind limb function was similar across all groups. However, we did find fewer macrophages at 1 week post-injury, more macrophages polarized towards a pro-regenerative phenotype at 1 and 8 weeks after injury, and reduced injury volume, more astrocytes, and more axons at 8 weeks after injury in rats with MSC-NHC and NHC alone compared with MSC-PBS; these findings were especially significant between rats with MSC-NHC and MSC-PBS. The data support further study in the use of an NHC-MSC combination transplant in the contused spinal cord

    A sutureless technique for securing leaking sclerotomies with viscoelastic substances in 23-gauge microincision vitrectomy surgery

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    AIM: To introduce and evaluate the clinical efficacy of a new technique, the use of viscoelastic substances (VS) to close leaking sclerotomy in 23G microincision vitrectomy, and to observe its effect on the visual acuity and intraocular pressure (IOP) of patients. METHODS: Patients who underwent 23G vitrectomy in Ningbo Eye Hospital before the use of VS technique (June 2019 to September 2020) and after the use of VS technique (October 2020 to December 2021) were selected as the subjects of this study. The above cases underwent operation by the same surgeon and were retrospectively analyzed. VS technique was used as the alternative to suturing, in which a small amount of VS was injected at the leaking sclerotomy and then gently massaged to confirm leaking sclerotomy closure. RESULTS: A total of 174 eyes were covered in the study, including 84 eyes in the control group (before the use of VS technique) and 90 eyes in the VS technique group. The number of eyes that needed to be sutured decreased considerably from 42.9% in the control group to 3.3% in the VS technique group, and the proportion of subconjunctival hemorrhage at 1-2d after surgery decreased remarkably from 35.7% in the control group to 2.2% in the VS technique group. No substantial differences in the incidence of mean IOP and low IOP were found between 1-2 and 3-20d after surgery in the VS technique group. No major complications associated with VS technique were identified during the study. CONCLUSION: In 23G microincision vitrectomy, VS technique is a safe, simple, and effective method to close leaking sclerotomy

    Designable ultra-smooth ultra-thin solid-electrolyte interphases of three alkali metal anodes

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    该研究是在毛秉伟教授和董全峰教授共同指导下,由2014级博士生谷宇、2016级博士生王卫伟、2013级博士生李艺娟等同学通力合作的成果。泉州师范学院吴启辉教授和上海应用物理研究所樊春海研究员分别在X射线光电子能谱表征和同步辐射表征中提供了大力支持。化学化工学院郑明森副教授、颜佳伟教授、吴德印教授、iChEM研究员丁松园博士在实验和理论计算方面给予了大力帮助;田中群教授和郑南峰教授等对此工作提出了宝贵意见。 金属锂是下一代高能量密度二次电池最理想的负极材料之一。在以金属锂作为负极的电池中,锂电沉积过程中枝晶的生长及溶解过程的死锂现象是制约电池库仑效率、稳定性和安全性的重要因素,而金属锂表面的微观平整性及固态电解质界面(SEI)膜的组成和结构及由其所决定的电学和力学性质对锂电沉积和溶解行为有重要影响。 课题组所发展的电化学调控方法可进一步拓展到钠、钾碱金属负极上,形成大范围原子平整的钠、钾表面和超薄超光滑的SEI膜。特别是金属钠平面电极可在2 mA cm–2(1 mAh cm–2)100% Na DOD下稳定循环550周以上且库伦效率近100%。这一基于电化学调控的碱金属表面抛光和SEI膜构筑的方法及多尺度联合表征,为解决碱金属负极问题提供了新的思路,也为开展表面科学基础研究提供高质量的碱金属表面。【Abstract】Dendrite growth of alkali metal anodes limited their lifetime for charge/discharge cycling. Here, we report near-perfect anodes of lithium, sodium, and potassium metals achieved by electrochemical polishing, which removes microscopic defects and creates ultra-smooth ultra-thin solid-electrolyte interphase layers at metal surfaces for providing a homogeneous environment. Precise characterizations by AFM force probing with corroborative in-depth XPS profile analysis reveal that the ultra-smooth ultra-thin solid-electrolyte interphase can be designed to have alternating inorganic-rich and organic-rich/mixed multi-layered structure, which offers mechanical property of coupled rigidity and elasticity. The polished metal anodes exhibit significantly enhanced cycling stability, specifically the lithium anodes can cycle for over 200 times at a real current density of 2 mA cm-2 with 100% depth of discharge. Our work illustrates that an ultra-smooth ultra-thin solid-electrolyte interphase may be robust enough to suppress dendrite growth and thus serve as an initial layer for further improved protection of alkali metal anodes.This work was supported by the MOST projects (2015CB251102, 2012CB932902) and the NSFC projects (U1305246, 21621091, 21473147, 21533006, 21673193). 研究工作得到科技部973计划(项目批准号:2015CB251102、2012CB932902),国家自然科学基金(项目批准号:U1305246、21621091、21473147、21533006、21673193)等项目的资助

    Prospects for detection rate of very-high-energy {\gamma}-ray emissions from short {\gamma}-ray bursts with the HADAR experiment

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    The observation of short gamma ray bursts (SGRBs) in the TeV energy range plays an important role in understanding the radiation mechanism and probing new areas of physics such as Lorentz invariance violation. However, no SGRB has been observed in this energy range due to the short duration of SGRBs and the weakness of current experiments. New experiments with new technology are required to detect sub-TeV SGRBs. In this work, we observe the very high energy (VHE) γ\gamma-ray emissions from SGRBs and calculate the annual detection rate with the High Altitude Detection of Astronomical Radiation HADAR (HADAR) experiment. First, a set of pseudo-SGRB samples is generated and checked using the observations of Fermi-GBM, Fermi-LAT, and SWIFT measurements. The annual detection rate is calculated from these SGRB samples based on the performance of the HADAR instrument. As a result, the HADAR experiment can detect 0.5 SGRB per year if the spectral break-off of γ\gamma-rays caused by the internal absorption is larger than 100 GeV. For a GRB09010-like GRB in HADAR's view, it should be possible to detect approximately 2000 photons considering the internal absorption. With a time delay assumption due to the Lorentz invariance violation effects, a simulated light curve of GRB090510 has evident energy dependence. We hope that the HADAR experiment can perform the SGRB observations and test our calculations in the future

    The LAMOST Survey of Background Quasars in the Vicinity of the Andromeda and Triangulum Galaxies -- II. Results from the Commissioning Observations and the Pilot Surveys

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    We present new quasars discovered in the vicinity of the Andromeda and Triangulum galaxies with the LAMOST during the 2010 and 2011 observational seasons. Quasar candidates are selected based on the available SDSS, KPNO 4 m telescope, XSTPS optical, and WISE near infrared photometric data. We present 509 new quasars discovered in a stripe of ~135 sq. deg from M31 to M33 along the Giant Stellar Stream in the 2011 pilot survey datasets, and also 17 new quasars discovered in an area of ~100 sq. deg that covers the central region and the southeastern halo of M31 in the 2010 commissioning datasets. These 526 new quasars have i magnitudes ranging from 15.5 to 20.0, redshifts from 0.1 to 3.2. They represent a significant increase of the number of identified quasars in the vicinity of M31 and M33. There are now 26, 62 and 139 known quasars in this region of the sky with i magnitudes brighter than 17.0, 17.5 and 18.0 respectively, of which 5, 20 and 75 are newly-discovered. These bright quasars provide an invaluable collection with which to probe the kinematics and chemistry of the ISM/IGM in the Local Group of galaxies. A total of 93 quasars are now known with locations within 2.5 deg of M31, of which 73 are newly discovered. Tens of quasars are now known to be located behind the Giant Stellar Stream, and hundreds behind the extended halo and its associated substructures of M31. The much enlarged sample of known quasars in the vicinity of M31 and M33 can potentially be utilized to construct a perfect astrometric reference frame to measure the minute PMs of M31 and M33, along with the PMs of substructures associated with the Local Group of galaxies. Those PMs are some of the most fundamental properties of the Local Group.Comment: 26 pages, 6 figures, AJ accepte

    Stem Cell Therapy with Overexpressed VEGF and PDGF Genes Improves Cardiac Function in a Rat Infarct Model

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    Therapeutic potential was evaluated in a rat model of myocardial infarction using nanofiber-expanded human cord blood derived hematopoietic stem cells (CD133+/CD34+) genetically modified with VEGF plus PDGF genes (VIP).Myocardial function was monitored every two weeks up to six weeks after therapy. Echocardiography revealed time dependent improvement of left ventricular function evaluated by M-mode, fractional shortening, anterior wall tissue velocity, wall motion score index, strain and strain rate in animals treated with VEGF plus PDGF overexpressed stem cells (VIP) compared to nanofiber expanded cells (Exp), freshly isolated cells (FCB) or media control (Media). Improvement observed was as follows: VIP>Exp> FCB>media. Similar trend was noticed in the exercise capacity of rats on a treadmill. These findings correlated with significantly increased neovascularization in ischemic tissue and markedly reduced infarct area in animals in the VIP group. Stem cells in addition to their usual homing sites such as lung, spleen, bone marrow and liver, also migrated to sites of myocardial ischemia. The improvement of cardiac function correlated with expression of heart tissue connexin 43, a gap junctional protein, and heart tissue angiogenesis related protein molecules like VEGF, pNOS3, NOS2 and GSK3. There was no evidence of upregulation in the molecules of oncogenic potential in genetically modified or other stem cell therapy groups.Regenerative therapy using nanofiber-expanded hematopoietic stem cells with overexpression of VEGF and PDGF has a favorable impact on the improvement of rat myocardial function accompanied by upregulation of tissue connexin 43 and pro-angiogenic molecules after infarction

    Human Umbilical Cord Blood-Derived CD34+ Cells Reverse Osteoporosis in NOD/SCID Mice by Altering Osteoblastic and Osteoclastic Activities

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    Osteoporosis is a bone disorder associated with loss of bone mineral density and micro architecture. A balance of osteoblasts and osteoclasts activities maintains bone homeostasis. Increased bone loss due to increased osteoclast and decreased osteoblast activities is considered as an underlying cause of osteoporosis.The cures for osteoporosis are limited, consequently the potential of CD34+ cell therapies is currently being considered. We developed a nanofiber-based expansion technology to obtain adequate numbers of CD34(+) cells isolated from human umbilical cord blood, for therapeutic applications. Herein, we show that CD34(+) cells could be differentiated into osteoblastic lineage, in vitro. Systemically delivered CD34(+) cells home to the bone marrow and significantly improve bone deposition, bone mineral density and bone micro-architecture in osteoporotic mice. The elevated levels of osteocalcin, IL-10, GM-CSF, and decreased levels of MCP-1 in serum parallel the improvements in bone micro-architecture. Furthermore, CD34(+) cells improved osteoblast activity and concurrently impaired osteoclast differentiation, maturation and functionality.These findings demonstrate a novel approach utilizing nanofiber-expanded CD34(+) cells as a therapeutic application for the treatment of osteoporosis

    Genomewide association study of leprosy.

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    BACKGROUND: The narrow host range of Mycobacterium leprae and the fact that it is refractory to growth in culture has limited research on and the biologic understanding of leprosy. Host genetic factors are thought to influence susceptibility to infection as well as disease progression. METHODS: We performed a two-stage genomewide association study by genotyping 706 patients and 1225 controls using the Human610-Quad BeadChip (Illumina). We then tested three independent replication sets for an association between the presence of leprosy and 93 single-nucleotide polymorphisms (SNPs) that were most strongly associated with the disease in the genomewide association study. Together, these replication sets comprised 3254 patients and 5955 controls. We also carried out tests of heterogeneity of the associations (or lack thereof) between these 93 SNPs and disease, stratified according to clinical subtype (multibacillary vs. paucibacillary). RESULTS: We observed a significant association (P<1.00x10(-10)) between SNPs in the genes CCDC122, C13orf31, NOD2, TNFSF15, HLA-DR, and RIPK2 and a trend toward an association (P=5.10x10(-5)) with a SNP in LRRK2. The associations between the SNPs in C13orf31, LRRK2, NOD2, and RIPK2 and multibacillary leprosy were stronger than the associations between these SNPs and paucibacillary leprosy. CONCLUSIONS: Variants of genes in the NOD2-mediated signaling pathway (which regulates the innate immune response) are associated with susceptibility to infection with M. leprae

    Aggregation-Induced Emission (AIE), Life and Health

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    Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health
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