VO

VO
  • 文章类型: Journal Article
    纳米材料中氧空位(Vo)的工程可以有效地控制其理化性质。SrTiO3具有典型的ABO3结构,由于其化学稳定性和高导带能量,在钛酸盐中引起了广泛的关注。这导致其在光催化能源相关过程中的广泛使用,在其他人中。在这里,我们介绍了火焰喷雾热解(FSP)的使用;一种工业和可扩展的工艺来生产富含Vo的SrTiO3钙钛矿。我们介绍了两种使用CH4气体作为还原源的缺氧火焰喷雾热解(A-FSP)技术:径向A-FSP(RA-FSP);和轴向A-FSP(AA-FSP)。这些用于SrTiO3-x纳米晶格中氧空位的控制工程。基于X射线光电子能谱,拉曼和热重-差热分析,我们讨论了Vos在如此生产的纳米SrTiO3-x中的作用和数量,与SrTiO3-x的纳米晶格性质和能带结构相关。目前的工作进一步证实了FSP作为一种合成工艺的多功能性,以及该工艺在未来潜在的应用,以制造具有氧空位的光催化剂,其数量可以以千克为单位进行测量。
    Engineering of oxygen vacancies (Vo) in nanomaterials allows diligent control of their physicochemical properties. SrTiO3 possesses the typical ABO3 structure and has attracted considerable attention among the titanates due to its chemical stability and its high conduction band energy. This has resulted in its extensive use in photocatalytic energy-related processes, among others. Herein, we introduce the use of Flame Spray Pyrolysis (FSP); an industrial and scalable process to produce Vo-rich SrTiO3 perovskites. We present two types of Anoxic Flame Spray Pyrolysis (A-FSP) technologies using CH4 gas as a reducing source: Radial A-FSP (RA-FSP); and Axial A-FSP (AA-FSP). These are used for the control engineering of oxygen vacancies in the SrTiO3-x nanolattice. Based on X-ray photoelectron spectroscopy, Raman and thermogravimetry-differential thermal analysis, we discuss the role and the amount of the Vos in the so-produced nano-SrTiO3-x, correlating the properties of the nanolattice and energy-band structure of the SrTiO3-x. The present work further corroborates the versatility of FSP as a synthetic process and the potential future application of this process to engineer photocatalysts with oxygen vacancies in quantities that can be measured in kilograms.
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  • 文章类型: Journal Article
    本研究旨在探索(-)-表没食子儿茶素没食子酸酯(EGCG)预防肥胖相关性早熟的潜在调控途径。对从人体随机对照试验中收集的血浆样本进行了EGCG对肥胖女孩青春期发作影响的回顾性分析。在审判中,参与者服用EGCG胶囊12周。在动物实验中,大鼠分为4组:正常饮食对照组(NC),高脂饮食(HFD)组,NC+EGCG组,HFD+EGCG组。在出生后第27、33和36天收集血液样本以检测性发育指标。通过RT-qPCR和Westernblot检测下丘脑kisspeptin/Kiss1R和神经激肽B(NKB)/NK3R信号的表达。通过免疫组织化学测定评估卵巢NKB蛋白表达。EGCG组的血清NKB水平比安慰剂组低0.599ng/mL[β=-0.599,95%CI:(-1.005,-0.193)],在干预结束时和校正混杂因素后(临床研究)。在动物实验中,EGCG干预能显著延缓HFD大鼠的阴道开放时间。第33天,EGCG干预可显著降低血清NKB,黄体生成素(LH)水平,卵巢NKB蛋白表达,和HFD喂养大鼠的子宫内膜厚度,EGCG干预能显著增加NKB/NK3R的mRNA和蛋白表达。EGCG通过NKB/NK3R信号通路预防肥胖相关性早熟,这可能为EGCG在预防肥胖女孩性早熟中的作用提供了新的见解。
    This study aimed to explore the potential regulatory pathways of (-)-epigallocatechin-3-gallate (EGCG) in preventing obesity-related precocious puberty. A retrospective analysis on the impact of EGCG on puberty onset in obese girls was conducted on plasma samples collected from a human randomized controlled trial. In the trial, participants consumed EGCG capsules for 12 weeks. In the animal experiment, rats were divided into four groups: normal diet control (NC) group, high-fat diet (HFD) group, NC+EGCG group, and HFD+EGCG group. Blood samples were collected on postnatal days 27, 33, and 36 to detect sexual development indicators. The hypothalamic expressions of kisspeptin/Kiss1R and neurokinin B (NKB)/NK3R signaling were measured by RT-qPCR and Western blot assay. The ovary NKB protein expression was assessed by immunohistochemical assays. Serum NKB level in the EGCG group was lower than the placebo group by 0.599 ng/mL [β=-0.599, 95% CI: (-1.005, -0.193)], at the end of intervention and after adjusting for confounders (clinical study). In the animal experiment, EGCG intervention could significantly delay the vaginal opening (VO) time of rats fed with HFD. On day 33, EGCG intervention could significantly reduce serum NKB, luteinizing hormone (LH) levels, ovarian NKB protein expression, and endometrial thickness of HFD-fed rats, while EGCG intervention could remarkably increase mRNA and protein expression of NKB/NK3R. EGCG could prevent obesity-related precocious puberty through NKB/NK3R signaling pathway, which may provide a novel insight into the role of EGCG in preventing precocious puberty in obese girls.
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  • 文章类型: Journal Article
    人类视觉皮层被划分为不同的功能区,从低到高,变得越来越有选择性,对复杂的特征尺寸也越来越敏感。在这里,我们使用fMRI-BOLD信号的代表性相似性分析(RSA)来对LGN和以体素响应模式编码的低级刺激信息的多个视觉区域进行定量比较。我们的刺激集被选择为针对从LGN输入视觉皮层的四个功能不同的皮层下通道:两个消色差正弦波刺激,它们有利于高颞叶细胞和高空间小卵细胞通路的反应,分别,和两个彩色刺激隔离L/M-锥对手和S-锥对手途径,分别。每种刺激类型都有三个空间范围来采样中央凹和中央旁视野。有了RSA,我们定量比较了每个区域中个体刺激和刺激组合的反应专业化,以及这些在视觉皮层中的变化。首先,我们的结果在背侧视觉区域复制了已知的运动/闪烁反应偏好.此外,我们沿着腹侧视觉流识别出两个不同的梯度。在早期视觉区域(V1-V3),最强的差分表示是消色差高空间频率刺激,适合形式视觉,色差和消色差的差异非常弱。出现在腹侧枕骨区(V4,VO1和VO2),然而,是对彩色和消色差对比度的响应越来越强的分离,并且高空间频率表示的下降。这些梯度为视觉信息如何在视觉皮层中转换提供了新的见解。
    Human visual cortex is partitioned into different functional areas that, from lower to higher, become increasingly selective and responsive to complex feature dimensions. Here we use a Representational Similarity Analysis (RSA) of fMRI-BOLD signals to make quantitative comparisons across LGN and multiple visual areas of the low-level stimulus information encoded in the patterns of voxel responses. Our stimulus set was picked to target the four functionally distinct subcortical channels that input visual cortex from the LGN: two achromatic sinewave stimuli that favor the responses of the high-temporal magnocellular and high-spatial parvocellular pathways, respectively, and two chromatic stimuli isolating the L/M-cone opponent and S-cone opponent pathways, respectively. Each stimulus type had three spatial extents to sample both foveal and para-central visual field. With the RSA, we compare quantitatively the response specializations for individual stimuli and combinations of stimuli in each area and how these change across visual cortex. First, our results replicate the known response preferences for motion/flicker in the dorsal visual areas. In addition, we identify two distinct gradients along the ventral visual stream. In the early visual areas (V1-V3), the strongest differential representation is for the achromatic high spatial frequency stimuli, suitable for form vision, and a very weak differentiation of chromatic versus achromatic contrast. Emerging in ventral occipital areas (V4, VO1 and VO2), however, is an increasingly strong separation of the responses to chromatic versus achromatic contrast and a decline in the high spatial frequency representation. These gradients provide new insight into how visual information is transformed across the visual cortex.
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  • 文章类型: Journal Article
    A 3D network composed of V2O5 nanofibers was manufactured on a novel conductive printing paper [urea-LiClO4-PVA (ULP) deep eutectic solvent gel-doped graphite/printing paper, U-paper] for use as electrodes linked with a ULP neutral gel electrolyte for 3D network V2O5 wearable symmetric pseudocapacitors (WSSCs). The function of the ULP gel is not only that it can be doped into the conductive ink to decrease the resistance of the conductive printing paper but also that it increases the stability of V2O5-based electrodes. Moreover, 3D network V2O5 WSSCs containing the ULP gel can support high operating voltages of 4.0 V with great specific capacitance (160 F/g) and offer a high energy density (355 W h/kg at 0.2 kW/kg). The 3D network V2O5 WSSCs exhibit a superior cycling stability/durability after 5000 cycles (capacitance retention of ∼91%). Operando X-ray absorption spectroscopy experiments show the reversibility and pseudocapacitive properties of V2O5 from the ULP gel and offer the information of the oxidation states of vanadium during charge-discharge cycles. The 3D network V2O5 WSSCs with the ULP gel electrolyte show great potential prospective candidates for smarter 3D wearable energy-storage devices and Internet-of-Things applications.
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  • 文章类型: Journal Article
    Introduction: Reference values for cardiopulmonary exercise testing (CPET) parameters provide the comparative basis for answering important questions concerning the normalcy of exercise responses in patients, and significantly impacts the clinical decision-making process. Areas covered: The aim of this study was to provide an updated systematic review of the literature on reference values for CPET parameters in healthy subjects across the life span. A systematic search in MEDLINE, Embase, and PEDro databases were performed for articles describing reference values for CPET published between March 2014 and February 2019. Expert opinion: Compared to the review published in 2014, more data have been published in the last five years compared to the 35 years before. However, there is still a lot of progress to be made. Quality can be further improved by performing a power analysis, a good quality assurance of equipment and methodologies, and by validating the developed reference equation in an independent (sub)sample. Methodological quality of future studies can be further improved by measuring and reporting the level of physical activity, by reporting values for different racial groups within a cohort as well as by the exclusion of smokers in the sample studied. Normal reference ranges should be well defined in consensus statements.
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  • 文章类型: Journal Article
    Spinal cord injury (SCI) derives in loss of bone mineral content (BMC) and bone mineral density (BMD). However, physical activity is an important determinant in bone mass acquisition, which is partially mediated through the lean mass (LM). The aim was to examine the effect of cardiorespiratory fitness (CRF) on BMD and BMC arms of adult males with SCI and able-bodied controls using the arm LM as a mediator variable. Thirty able-bodied men and thirty men with SCI participated. BMC and BMD were analysed by DXA, and indirect calorimetry was used to calculate VO2peak during a progressive arm-cranking test. When groups were divided by the amount of LM, the subgroup with highest LM had significantly higher arm BMC compared to the lowest LM subgroup (p ≤ 0.05) in both SCI and able-bodied groups. Moreover, same differences were found when confidence intervals were analysed. Only in the SCI group, arm LM mediated the relationship between bone mass and CRF at 30.9%, as indicated by the Sobel test (z = 2.17 and z = 2.04 for BMC and BMD, respectively). In conclusion, LM mediates the indirect association between CRF and bone health, specifically in the arms. This finding highlights the importance of having an adequate CRF for the maintenance of good bone health in SCI men.
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  • 文章类型: Journal Article
    Drones are becoming increasingly significant for vast applications, such as firefighting, and rescue. While flying in challenging environments, reliable Global Navigation Satellite System (GNSS) measurements cannot be guaranteed all the time, and the Inertial Navigation System (INS) navigation solution will deteriorate dramatically. Although different aiding sensors, such as cameras, are proposed to reduce the effect of these drift errors, the positioning accuracy by using these techniques is still affected by some challenges, such as the lack of the observed features, inconsistent matches, illumination, and environmental conditions. This paper presents an integrated navigation system for Unmanned Aerial Vehicles (UAVs) in GNSS denied environments based on a Radar Odometry (RO) and an enhanced Visual Odometry (VO) to handle such challenges since the radar is immune against these issues. The estimated forward velocities of a vehicle from both the RO and the enhanced VO are fused with the Inertial Measurement Unit (IMU), barometer, and magnetometer measurements via an Extended Kalman Filter (EKF) to enhance the navigation accuracy during GNSS signal outages. The RO and VO are integrated into one integrated system to help overcome their limitations, since the RO measurements are affected while flying over non-flat terrain. Therefore, the integration of the VO is important in such scenarios. The experimental results demonstrate the proposed system\'s ability to significantly enhance the 3D positioning accuracy during the GNSS signal outage.
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  • 文章类型: Journal Article
    BACKGROUND: A major effect of cyanide toxicity (CN) and vascular occlusion (VO) is the production of reactive oxygen species (ROS) linked with a defective energy coupling process in the mitochondria. In CN, oxygen is present but its conversion is blocked in the mitochondria (Complex V). By contrast, in VO, oxidative stress is induced via reduction of oxygen (blood) circulation to the occluded brain region. We hypothesize that differential oxygen concentration in both forms of ischemia affect ROS production rate in the mitochondria; thus distinguishing the cytotoxicity pattern for CN and VO.
    METHODS: Male, adult Wistar rats (N = 30) were separated into three groups. A set of n = 12 animals were treated with orally administered potassium ferricyanide. Global vascular occlusion (GVO) was induced in a second set of animals (n = 12) using neck cuffs to occlude the common carotid arteries and brachiocephalic vein. The control group (n = 6) received normal saline for the total duration of the treatment (10 days). Glutathione (GSH), superoxide dismutase (SOD), glutathione peroxidase (GPx), malondialdehyde (MDA) and acid phosphatase (ACP) levels were assayed in tissue homogenate using colorimetric assay techniques while Cathepsin D (CAD+) was demonstrated through antigen retrieval immunohistochemistry. Data were analyzed in One Way ANOVA with Tukey\'s post-hoc test. Significance was set p < 0.05.
    CONCLUSIONS: Cyanide treatment and VO caused a significant rise in SOD; attributed to ROS formation in both forms of ischemia. However, an increase in GSH levels demonstrates mitochondria-ROS production in cyanide treatment while no significant change in GSH was observed in VO versus the control (reduced mitochondria-ROS production). In addition, CN recorded a significant increase in GSH when compared with the control and VO (p < 0.001). The level of ROS was also proportional to the degree of lipid peroxidation (GPx) and autophagic cell response (ACP/CAD+). Ultimately, the lipid peroxidation/ROS effect was more significant in CN than VO.
    CONCLUSIONS: Although CN and VO induced oxidative stress through ROS production, our findings suggest a difference in the threshold of ROS production and cytotoxicity for both forms of ischemia. However, this threshold is dependent on the availability of oxygen to fuel mitochondria-ROS production in oxidative stress. Ultimately, the difference in oxygen availability in vivo determined the significance of lipid peroxidation, calcium-shift and autophagic cell response associated with the ischemia. CN treatment generated more ROS and was associated with prominent cellular changes when compared with VO.
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  • 文章类型: Journal Article
    关于人类大脑对颜色的反应如何在视觉通路内组织存在争议。一个关键问题是是否存在选择性响应颜色的模块化途径,或者是否存在颜色和消色差(Ach)对比度的共同神经底物。我们使用功能磁共振成像(fMRI)适应来研究早期和超视觉区域对颜色和Ach对比度的反应。高对比度红绿(RG)和Ach正弦波环(0.5周期/度,2Hz)用作块设计中的适应刺激和测试刺激。我们在所有视觉区域中发现了对RG或Ach对比度的强大适应。RG和Ach对比度之间的交叉适应发生在所有区域,表明存在整合,颜色和Ach响应。值得注意的是,我们揭示了两种测试刺激的对比趋势。对于RG测试,非选择性处理(对RG和Ach对比度的强大适应)在早期视觉区域(V1和V2)中最为明显,但是选择性反应,揭示出相同刺激之间的适应大于不同刺激之间的交叉适应,出现在腹侧皮层,特别是在V4和VO中。对于Ach测试,非选择性反应在早期视觉区域再次最明显,但Ach选择性出现在背侧皮层(V3a和hMT)。我们的发现支持在视觉层次结构中强烈存在颜色和Ach对比度的集成机制,随着在不同视觉区域的选择性处理的进展。
    There is controversy as to how responses to colour in the human brain are organized within the visual pathways. A key issue is whether there are modular pathways that respond selectively to colour or whether there are common neural substrates for both colour and achromatic (Ach) contrast. We used functional magnetic resonance imaging (fMRI) adaptation to investigate the responses of early and extrastriate visual areas to colour and Ach contrast. High-contrast red-green (RG) and Ach sinewave rings (0.5 cycles/degree, 2 Hz) were used as both adapting stimuli and test stimuli in a block design. We found robust adaptation to RG or Ach contrast in all visual areas. Cross-adaptation between RG and Ach contrast occurred in all areas indicating the presence of integrated, colour and Ach responses. Notably, we revealed contrasting trends for the two test stimuli. For the RG test, unselective processing (robust adaptation to both RG and Ach contrast) was most evident in the early visual areas (V1 and V2), but selective responses, revealed as greater adaptation between the same stimuli than cross-adaptation between different stimuli, emerged in the ventral cortex, in V4 and VO in particular. For the Ach test, unselective responses were again most evident in early visual areas but Ach selectivity emerged in the dorsal cortex (V3a and hMT+). Our findings support a strong presence of integrated mechanisms for colour and Ach contrast across the visual hierarchy, with a progression towards selective processing in extrastriate visual areas.
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  • 文章类型: Journal Article
    While there are many state-of-the-art approaches to introducing telemedical services in the area of medical imaging, it is hard to point to studies which would address all relevant aspects in a complete and comprehensive manner. In this paper we describe our approach to design and implementation of a universal platform for imaging medicine which is based on our longstanding experience in this area. We claim it is holistic, because, contrary to most of the available studies it addresses all aspects related to creation and utilization of a medical teleconsultation workspace. We present an extensive analysis of requirements, including possible usage scenarios, user needs, organizational and security issues and infrastructure components. We enumerate and analyze multiple usage scenarios related to medical imaging data in treatment, research and educational applications - with typical teleconsultations treated as just one of many possible options. Certain phases common to all these scenarios have been identified, with the resulting classification distinguishing several modes of operation (local vs. remote, collaborative vs. non-interactive etc.). On this basis we propose a system architecture which addresses all of the identified requirements, applying two key concepts: Service Oriented Architecture (SOA) and Virtual Organizations (VO). The SOA paradigm allows us to decompose the functionality of the system into several distinct building blocks, ensuring flexibility and reliability. The VO paradigm defines the cooperation model for all participating healthcare institutions. Our approach is validated by an ICT platform called TeleDICOM II which implements the proposed architecture. All of its main elements are described in detail and cross-checked against the listed requirements. A case study presents the role and usage of the platform in a specific scenario. Finally, our platform is compared with similar systems described into-date studies and available on the market.
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