68 research outputs found
Therapeutic Effects of Transplantation of As-MiR-937-Expressing Mesenchymal Stem Cells in Murine Model of Alzheimer's Disease
The Strain Seismograms of P- and S-Waves of a Local Event Recorded by Four-Gauge Borehole Strainmeter
At a sampling rate of 100 samples per second, the YRY-4 four-gauge borehole strainmeters (FGBS) are capable of recording transient strains caused by seismic waves such as P and S waves or strain seismograms. At such a high sampling rate, data from the YRY-4 strainmeters demonstrate fairly satisfactory self-consistency. The strain tensor seismograms demonstrate the senses of motion of P waves, that is, the type of seismic wave travels in the direction of the maximum normal strain change. The observed strain patterns of S waves significantly differ from those of P waves and should contain information about the source mechanism. Spectrum analysis shows that the strain seismograms are consistent with conventional broadband seismograms from the same site
Relationship between Carotid Artery Sclerosis and Blood Pressure Variability in Essential Hypertension Patients
Objectives:
This study aimed to investigate the relationship between the presence of carotid arteriosclerosis (CAS) and blood pressure variability (BPV) in patients with essential hypertension.
Methods:
One hundred and forty four essential hypertension patients underwent ambulatory BP monitoring for 24 hours after hospitalization. Common BPV metrics were calculated. General clinical parameters, including age, gender, height, weight, history of coronary heart disease, stroke, diabetes, hypertension, smoking and drink, were recorded. Biochemical indices were obtained from a blood test. Carotid intima-media thickness (IMT) and carotid plaques were assessed to separate patients into a non-CAS group (IMTβ€0.9 mm; n=82) and a CAS group (IMT>0.9 mm; n=62). BPV metrics and clinical parameters were analyzed and compared between the two groups. Multivariate logistic regression analysis was performed to determine the associated risk factors of CAS.
Results:
Multivariate logistic regression analysis revealed that two BPV metrics, the standard deviation of daytime systolic blood pressure (SSD) (OR: 1.587, 95%CI: 1.242β2.028), the difference between average daytime SBP and nighttime SBP (OR: 0.914, 95%CI: 0.855-0.977), as well as three clinical parameters (age, OR: 1.098, 95%CI: 1.034-1.167; smoking, OR: 4.072, 95%CI: 1.466β11.310, and fasting blood glucose, OR: 2.029, 95%CI: 1.407β2.928), were significant factors of CAS in essential hypertension patients.
Conclusion:
SSD, in combination with the ageing, smoking and FBG, has been identified as risk factors for CAS in patients with essential hypertension
The Bantam microRNA Is Associated with Drosophila Fragile X Mental Retardation Protein and Regulates the Fate of Germline Stem Cells
Fragile X syndrome, a common form of inherited mental retardation, is caused by the loss of fragile X mental retardation protein (FMRP). We have previously demonstrated that dFmr1, the Drosophila ortholog of the fragile X mental retardation 1 gene, plays a role in the proper maintenance of germline stem cells in Drosophila ovary; however, the molecular mechanism behind this remains elusive. In this study, we used an immunoprecipitation assay to reveal that specific microRNAs (miRNAs), particularly the bantam miRNA (bantam), are physically associated with dFmrp in ovary. We show that, like dFmr1, bantam is not only required for repressing primordial germ cell differentiation, it also functions as an extrinsic factor for germline stem cell maintenance. Furthermore, we find that bantam genetically interacts with dFmr1 to regulate the fate of germline stem cells. Collectively, our results support the notion that the FMRP-mediated translation pathway functions through specific miRNAs to control stem cell regulation
Circadian Rhythm-Dependent Alterations of Gene Expression in Drosophila Brain Lacking Fragile X Mental Retardation Protein
Fragile X syndrome is caused by the loss of the FMR1 gene product, fragile X mental retardation protein (FMRP). The loss of FMRP leads to altered circadian rhythm behaviors in both mouse and Drosophila; however, the molecular mechanism behind this phenomenon remains elusive. Here we performed a series of gene expression analyses, including of both mRNAs and microRNAs (miRNAs), and identified a number of mRNAs and miRNAs (miRNA-1 and miRNA-281) with circadian rhythm-dependent altered expression in dfmr1 mutant flies. Identification of these RNAs lays the foundation for future investigations of the molecular pathway(s) underlying the altered circadian rhythms associated with loss of dFmr1
Therapeutic Effects of Transplantation of As-MiR-937-Expressing Mesenchymal Stem Cells in Murine Model of Alzheimer's Disease
Background/Aims: Alzheimer's disease (AD) is one of the most common dementias among aged people, and is clinically characterized by progressive memory loss, behavioral and learning dysfunction and cognitive deficits. So far, this is no cure for AD. A therapeutic effect of transplantation of mesenchymal stem cells (MSCs) into murine model of AD has been reported, but remains to be further improved. Brn-4 is a transcription factor that plays a critical role in neuronal development, whereas the effects of Brn-4 overexpression in transplanted MSCs on AD are unknown. Methods: MSCs were isolated from mouse bone marrow and induced to overexpress antisense of miRNA-937 (as-miR-937) through adeno-associated virus (AAV)-mediated transduction, and purified by flow cytometry based on expression of a GFP co-transgene in the cells. The Brn-4 levels in mouse MSCs were examined in miR-937-modified MSCs by RT-qPCR and by Western blot. These miR-937-modified MSCs were then transplanted into an APP/PS1 transgenic AD model in mice. The effects of saline control, MSCs and asmiR-937 MSCs on AD mice were examined by deposition of amyloid-beta peptide aggregates (AΞ²), social recognition test (SR), Plus-Maze Discriminative Avoidance Task (PM-DAT) and the levels of Brain-derived neurotrophic factor (BDNF) in the mouse brain. Results: MSCs expressed high levels of Brn-4 transcripts but low levels of Brn-4 protein. Poor protein vs mRNA levels of Brn-4 in MSCs appeared to result from the presence of high levels of miR-937 in MSCs. miR-937 inhibited translation of Brn-4 mRNA through binding to the 3'-UTR of the Brn-4 mRNA in MSCs. Expression of as-miR-937 significantly increased Brn-4 protein levels in MSCs. Transplantation of as-miR-937-expressing MSCs significantly reduced the deposition of AΞ², increased the levels of BDNF, and significantly improved the appearance in SR and PM-DAT in AD mice. Conclusion: Overexpression of as-miR-937 in MSCs may substantially improve the therapeutic effects of MSCs on AD, possibly through augmenting Brn-4 levels in MSCs
Simultaneous Extraction of Gold and Vanadium From Vanadium and Carbon-Rich Refractory Gold Minerals by Chlorination Roasting
To realize the efficient comprehensive utilization of refractory gold ore resources and environmental and economic gold extraction methods, this study investigated the optimal chlorine source for the sustained recovery of gold and vanadium from carbonaceous refractory gold ore by chlorination heat treatment. During the chlorination roasting process, the results indicated that CaCl2 has a greater chlorine supply capacity, and the reaction of refractory carbonaceous gold ore with CaCl2 was more intense than other chlorine sources. In addition, the effect of significant parameters (such as heat treatment temperature, heat treatment time, and CaCl2 additions) on gold and vanadium recovery ratios was carefully investigated. Under ideal conditions (i.e., CaCl2 concentration of 10 pct, heat treatment temperature of 1100 degrees C, heat treatment time of 4 hours, and air velocity of 1 L/min), 89.91 and 83.26 pct of gold and vanadium were recovered, respectively. In comparison, the main chemical mechanisms and phase transitions during the roasting process were studied by some analytical methods (such as scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, and thermodynamic data). All alkaline chlorine sources were shown to destroy the structure of the minerals. CaCl2 was the compound with the more potent effect. Pyrite could enhance the chlorination of gold below 700 degrees C. In contrast, vanadium oxide could promote chlorination of gold above 700 degrees C. In addition, the leaching residue is primarily made of CaVO3, which can be used as a raw material for vanadium smelting. However, silicon dioxide and iron oxide will react at temperatures above 1100 degrees C, forming the "silicon oxygen" inclusion that hampered vanadium extraction
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