142,994 research outputs found
Data for: Protective effect of umbilical cord mesenchymal stem cells combined with resveratrol against renal podocyte damage in NOD mice
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Building On and Honoring Forty Years of PBL Scholarship from Howard Barrows: A Scientometric, Large-Scale Data, and Visualization-based Analysis
Get PDFOver the past forty years, Howard Barrows’ contributions to PBL research have influenced and guided educational research and practice in a diversity of domains. It is necessary to make visible to all PBL scholars what has been accomplished, what is perceived as significant, and what is the scope of applicability for Barrows’ groundbreaking findings. As more disciplines recognize Barrows’ efforts and adopt PBL in education, it becomes crucial but challenging to sustain community memory so that PBL scholars are kept well informed of research innovations in various domains. In this paper, we review Barrows’ scholarly efforts in PBL and reveal the impacts on subsequent studies in various domains. A bibliometrics analysis is conducted on Barrows’ PBL publications and the corresponding citations to quantitatively measure Barrows’ impact. Our findings demonstrate Barrows’ exceptional contributions to PBL and the disciplinary differences in conducting PBL studies based on Barrows’ work. It is also revealed that PBL scholars who share similar interests have rarely collaborated with each other. The PBL research community has a real opportunity to connect isolated research groups and reduce the fragmentation so that research innovations in one domain can be disseminated to inform other scholars
Effect of background ionization on plasma ignition dynamics
No full textThe influence of background ionization on the ignition dynamics of the pulsed plasma plume is studied. The ignition delay time of each pulse is investigated by recording the voltage signal and the light emission signal. By changing the frequency, the relationship between the pulse-off time and the ignition delay time is revealed. This indicates that residual active species produced in the previous discharge play a role in the next one. With the decrease in the frequency, both time delay and ignition delay time increase. This is due to the decay of the reactive species densities in the pulse-off time. Lower concentrations of these species lead to a longer ignition delay time. The functions for calculating the ignition delay time are utilized to explain the effect of residual species. The independent data of each discharge also evidence the impact of the previous pulse. The exotic relationship between the ignition delay times of the first two pulses may be due to the electrode configuration used in this work. For a pin-to-plane electrode structure, the active species produced during the breakdown are accumulated around the anode (pin-point) where the discharge initiated for the asymmetrical electric field distribution
Density alteration in non-physiological cells
Get PDFIn the present study an important phenomenon of cells was discovered: the change of intracellular density in cell's response to drug and environmental factors. For convenience, this phenomenon is named as "density alteration in non-physiological cells" ( DANCE). DANCE was determined by discontinuous sucrose gradient centrifugation (DSGC), in which cells were separated into several bands. The number and position of the bands in DSGC varied with the change of cell culture conditions, drugs, and physical process, indicating that cell's response to these factors was associated with alteration of intracellular density. Our results showed that the bands of cells were molecularly different from each other, such as the expression of some mRNAs. For most cells tested, intracellular density usually decreased when the cells were in bad conditions, in presence of drugs, or undergoing pathological changes. However, unlike other tissue cells, brain cells showed increased intracellular density in 24 hrs after the animal death. In addition, DANCE was found to be related to drug resistance, with higher drug-resistance in cells of lower intracellular density. Further study found that DANCE also occurred in microorganisms including bacteria and fungus, suggesting that DANCE might be a sensitive and general response of cells to drugs and environmental change. The mechanisms for DANCE are not clear. Based on our study the following causes were hypothesized: change of metabolism mode, change of cell membrane function, and pathological change. DANCE could be important in medical and biological sciences. Study of DANCE might be helpful to the understanding of drug resistance, development of new drugs, separation of new subtypes from a cell population, forensic analysis, and importantly, discovery of new physiological or pathological properties of cells
Role of FGFs/FGFRs in skeletal development and bone regeneration
No full textAbstract not availableXiaolan Du, Yangli Xie, Cory J. Xian, Lin Che
Spatially-localized time dependent solutions including turbulence and their interactions in 2D Kolmogorov flow
No full textIn 2D Kolmogorov flow in small aspect ratio domains, spatially-localized solutions such as kink, traveling or time-dependent kink-antikink pars coexist. However, the conservation of the flow rate in the y direction strongly restrict combination of localized solutions and their positioning. We find that by adding a homogeneous flow U y their positioning is controlled and each of localized solutions including a spatially-localized chaos is isolated. Numerical results suggest that these isolated solutions can be elements constructing a whole flow
Quadrupolar transitions and medium-range-order effects in metal K-edge x-ray absorption spectra of 3d transition-metal compounds
No full textWe have investigated the pre-edge features in x-ray absorption spectra of transition metal (TM) monoxides at the metal K edge. By comparing the calculated dipolar and quadrupolar spectra with experiments we assign the first peak at the lowest energy to a direct quadrupolar transition (due to the more effective attraction of the core hole). The following peaks in this region are mainly dipolar in character and reflect the density of states due to the medium range order as long as the radius of the cluster equals the cation-cation shortest distance plus the nearest neighbor cation-anion bond, representing a band-like effect arising from the hybridization of the 4p orbitals of central TM atoms with the 3d-based octahedral molecular orbitals of the higher-neighboring cations
Characteristics of overlap region in high-Reynolds number turbulent channel flow
No full textDirect numerical simulation of the fully developed turbulent channel flows have been carried out at the Reynolds number based on the friction velocity and the channel half width, 2000, 4000 and 8000. A hybrid 10th order accurate finite difference scheme in the stream and spanwise directions, and a second-order scheme in the wall-normal direction is adapted as the spatial discretization method. We observed the plateau profiles in the indicator function corresponded to the von Karman constant. Furthermore, second peak of streamwise pre-multiplied spectra were appeared in the same wall normal height, 300 < y+ < 600, in case of Re = 4000. Nevertheless, the effects of the lager than the channel half height scale on the streamwise turbulent intensity are fixed contributions without dependence on Reynolds number. These results suggested that the new streamwise vortexes are formed between buffer layer and outer layer with increasing of Reynolds number
Surface deformation analysis of Xian (China) in 2009 carried out with refined SBAS-DInSAR
No full textInternational Symposium on Lidar and Radar Mapping 2011: Technologies and Applications, Nanjing, 26-29 May 2011Taking the land subsidence and ground fissure in Xian as the research object and nine Envisat ASAR images spanning the whole year of 2009 as the data source, time series surface deformation of Xian city from January to December in 2009 are obtained by SBAS-DInSAR approach, where the baselines and topographic phase were refined using ground control points (GCP). The results show that Xian is the state of continuous subsidence in 2009 and subsidence funnels are shaped nearly in oval whose long axis direction was approximately parallel to ground fissure direction. Meanwhile, the regional and seasonal characteristics were displayed for these subsidences regional. In addition, spatial distribution of strong activities and active regulation within the year between ground fissures and land subsidence are uniform based on this investigation.Department of Land Surveying and Geo-Informatic
The Impact of the New Rural Cooperative Medical Scheme on Activities and Financing of Township Hospitals in Weifang, China
Get PDFSince 2003, the New Rural Cooperative Medical Scheme, a community-based health insurance, is gradually implemented in China, in order to increase the access of the poor to healthcare services, reduce out-of-pocket expenditures and avoid catastrophic health expenditures. The paper estimates the impact of the New Rural Cooperative Medical Scheme on a sample of 24 randomly selected township hospitals of Weifang prefecture (Shandong province, China), using a generalized form of differences-in-differences model on longitudinal data over the period 2000-2008. Estimations highlight three main results. First, the New Rural Cooperative Medical Scheme has a positive impact on the utilization of township hospitals, mainly on inpatient services, but none effect on their financial structure. In addition, the positive impact on the volume of discharged patients is higher in poor areas rather than the non-poor, reflecting a decrease of the burden of hospitalization costs. Lastly, the marginal impact of the reform is decreasing over time.China, New Rural Cooperative Medical Scheme, Impact analysis, Township Hospitals.
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