168 research outputs found
Over-expression of HO-1 on mesenchymal stem cells promotes angiogenesis and improves myocardial function in infarcted myocardium
Heme oxygenase-1 (HO-1) is a stress-inducible enzyme with diverse cytoprotective effects, and reported to have an important role in angiogenesis recently. Here we investigated whether HO-1 transduced by mesenchymal stem cells (MSCs) can induce angiogenic effects in infarcted myocardium. HO-1 was transfected into cultured MSCs using an adenoviral vector. 1 × 106 Ad-HO-1-transfected MSCs (HO-1-MSCs) or Ad-Null-transfected MSCs (Null-MSCs) or PBS was respectively injected into rat hearts intramyocardially at 1 h post-myocardial infarction. The results showed that HO-1-MSCs were able to induce stable expression of HO-1 in vitro and in vivo. The capillary density and expression of angiogenic growth factors, VEGF and FGF2 were significantly enhanced in HO-1-MSCs-treated hearts compared with Null-MSCs-treated and PBS-treated hearts. However, the angiogenic effects of HO-1 were abolished by treating the animals with HO inhibitor, zinc protoporphyrin. The myocardial apoptosis was marked reduced with significantly reduced fibrotic area in HO-1-MSCs-treated hearts; Furthermore, the cardiac function and remodeling were also significantly improved in HO-1-MSCs-treated hearts. Our current findings support the premise that HO-1 transduced by MSCs can induce angiogenic effects and improve heart function after acute myocardial infarction
Relationship between suicide rate and economic growth and stock market in the People’s Republic of China: 2004–2013
Barrier Inhomogeneity of Schottky Diode on Nonpolar AlN Grown by Physical Vapor Transport
An aluminum nitride (AlN) Schottky barrier diode (SBD) was fabricated on a
nonpolar AlN crystal grown on tungsten substrate by physical vapor transport.
The Ni/Au-AlN SBD features a low ideality factor n of 3.3 and an effective
Schottky barrier height (SBH) of 1.05 eV at room temperature. The ideality
factor n decreases and the effective SBH increases at high temperatures. The
temperature dependences of n and SBH were explained using an inhomogeneous
model. A mean SBH of 2.105 eV was obtained for the Ni-AlN Schottky junction
from the inhomogeneity analysis of the current-voltage characteristics. An
equation in which the parameters have explicit physical meanings in thermionic
emission theory is proposed to describe the current-voltage characteristics of
inhomogeneous SBDs.Comment: 6 pages, 6 figure
Research and Design on Navigation Electronic Map System
This paper puts forward the new definition on the basis of the original concept of the navigation electronic map, designs the structure of the navigation electronic map system which contains three parts: hardware equipment, data system and software system, and analyzes each part of them in detail, finally this paper discusses the functional framework of the navigation electronic map
Generate, Filter, and Fuse: Query Expansion via Multi-Step Keyword Generation for Zero-Shot Neural Rankers
Query expansion has been proved to be effective in improving recall and
precision of first-stage retrievers, and yet its influence on a complicated,
state-of-the-art cross-encoder ranker remains under-explored. We first show
that directly applying the expansion techniques in the current literature to
state-of-the-art neural rankers can result in deteriorated zero-shot
performance. To this end, we propose GFF, a pipeline that includes a large
language model and a neural ranker, to Generate, Filter, and Fuse query
expansions more effectively in order to improve the zero-shot ranking metrics
such as nDCG@10. Specifically, GFF first calls an instruction-following
language model to generate query-related keywords through a reasoning chain.
Leveraging self-consistency and reciprocal rank weighting, GFF further filters
and combines the ranking results of each expanded query dynamically. By
utilizing this pipeline, we show that GFF can improve the zero-shot nDCG@10 on
BEIR and TREC DL 2019/2020. We also analyze different modelling choices in the
GFF pipeline and shed light on the future directions in query expansion for
zero-shot neural rankers
Dynamic aperture factor analysis/target transformation (DAFA/TT) for Mg-serpentine and Mg-carbonate mapping on Mars with CRISM near-infrared data
© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Lin, H., Tarnas, J. D., Mustard, J. F., Zhang, X., Wei, Y., Wan, W., Klein, F., & Kellner, J. R. Dynamic aperture factor analysis/target transformation (DAFA/TT) for Mg-serpentine and Mg-carbonate mapping on Mars with CRISM near-infrared data. Icarus, 355, (2021): 114168, https://doi.org/10.1016/j.icarus.2020.114168.Serpentine and carbonate are products of serpentinization and carbonation processes on Earth, Mars, and other celestial bodies. Their presence implies that localized habitable environments may have existed on ancient Mars. Factor Analysis and Target Transformation (FATT) techniques have been applied to hyperspectral data from the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) to identify possible serpentine and Mg-carbonate-bearing outcrops. FATT techniques are capable of suggesting the presence of individual spectral signals in complex spectral mixtures. Applications of FATT techniques to CRISM data thus far only evaluate whether an entire analyzed image (≈ 3 × 105 pixels) may contain spectral information consistent with a specific mineral of interest. The spatial distribution of spectral signal from the possible mineral is not determined, making it difficult to validate a reported detection and also to understand the geologic context of any purported detections. We developed a method called Dynamic Aperture Factor Analysis/Target Transformation (DAFA/TT) to highlight the locations in a CRISM observation (or any similar laboratory or remotely acquired data set) most likely to contain spectra of specific minerals of interest. DAFA/TT determines the locations of possible target mineral spectral signals within hyperspectral images by performing FATT in small moving windows with different geometries, and only accepting pixels with positive detections in all cluster geometries as possible detections. DAFA/TT was applied to a hyperspectral image of a serpentinite from Oman for validation testing in a simplified laboratory setting. The mineral distribution determined by DAFA/TT application to the laboratory hyperspectral image was consistent with Raman analysis of the serpentinite sample. DAFA/TT also successfully mapped the spatial distribution of Mg-serpentine and Mg-carbonate previously detected in CRISM data using band parameter mapping and extraction of ratioed spectra. We applied DAFA/TT to CRISM images in some olivine-rich regions of Mars to characterize the spatial distribution of Mg-serpentine and Mg-carbonate-bearing outcrops.This work was supported by the National Natural Science Foundation of China (grant no. 41671360, 41525016, 41902318). JFM and JDT acknowledge NASA support through a subcontract from the Applied Physics Lab for CRISM investigations. H. Lin also acknowledges the support from the key research Program of the Institute of Geology and Geophysics, CAS (IGGCAS-201905). The Headwall imaging spectrometer was acquired using funds to JRK from The Institute at Brown for Environment and Society and Brown University. The DAFA/TT codes are available on GitHub (https://github.com/linhoml?tab=repositories)
Trends of hypercholesterolemia change in Shenzhen, China during 1997-2018
To demonstrate the trends of hypercholesterolemia change in Shenzhen, China from 1997 to 2018. Participants were residents aged 18 to 69 years in Shenzhen, China, and were recruited using multi-stage cluster sampling. All participants were surveyed about their socio-demographics, lifestyle, occupation, mental health, and social support. Physical measurements and blood samples for subsequent measurements were collected according to a standardized protocol. A total of 26,621 individuals participated in the three surveys with 8,266 in 1997, 8,599 in 2009, and 9,756 in 2018. In both women and men, there was a significant downward linear trend in age-adjusted mean high-density lipoprotein-cholesterol (HDL-C) from 1997 to 2018 (women: 0.17 ± 0.06, p = 0.008 vs. men: 0.21 ± 0.04, p < 0.001). In contrast, the age-adjusted total triglycerides and total cholesterol in both sexes have demonstrated an increasing trend in the past two decades. However, no significant changes in age-adjusted low-density lipoprotein-cholesterol (LDL-C) in both men and women between 2009 and 2018 were found (women: 0.00 ± 0.02, p = 0.85 vs. men 0.02 ± 0.03, p = 0.34). The age-adjusted prevalence of hypercholesterolemia observed a rapid rise from 1997 to 2009 and appeared to be stabilized in 2018, which was similar to the trend of the prevalence of high total triglycerides in women. Changes in trends were varied by different types of lipids traits. Over the observed decades, there was a clear increasing trend of prevalence of low HDL-C (<1.04 mmol/L) in both sexes (women: 8.8% in 1997 and doubled to reach 17.5% in 2018 vs. men was 22.1% in 1997 and increased to 39.1% in 2018), particularly among younger age groups. Hence, a bespoke public health strategy aligned with the characteristics of lipids epidemic considered by sex and age groups needs to be developed and implemented
- …