59 research outputs found
Is devaluation expansionary or contractionary: Evidence based on vector autoregression with sign restrictions
The purpose of the paper is to examine the impact of real exchange rate changes - real devaluation or real depreciation - on outputs in 16 countries that fall within one of the three groups: Latin American countries, Asian countries, and non-G3 developed countries. For the first time in the contractionary devaluation literature, the analysis is based on a Vector Autoregression (VAR) model with sign restrictions method by Uhlig (2005) and Fry and Pagan (2011). The exchange rate shock is identified by imposing restrictions on the signs of impulse responses for a small subset of variables. The findings are as follows: (1) whether output increases after a real devaluation or not has little to do with whether the current account improves or not; (2) Latin American countries are quite homogenous in that the current account generally improves while output decreases after real devaluation; and (3) contractionary devaluation could happen in developed countries as well as in developing countries. © 2014 Elsevier Inc
Are the macroeconomic effects of oil price shock symmetric?: A Factor-Augmented Vector Autoregressive approach
This paper aims to examine the asymmetric effect of oil price shocks on real economic activity in the U.S. within the context of a nonlinear Factor-Augmented Vector Autoregressive (FAVAR) model. By employing simulation methods, we trace the effects of positive and negative oil price shocks on the macroeconomic variables through the Impulse Response Function (IRF). It is found that the negative impacts of higher oil prices are larger than the positive effects of lower oil prices. And the asymmetric effects are more evident when the oil price shocks are larger. The results are robust to different lag specification and choice of factors
EXCHANGE RATE and US MACROECONOMY: EVIDENCE from the FACTOR-AUGMENTED VECTOR AUTOREGRESSIVE MODEL
This paper aims to examine the macroeffects of exchange rate movements on a wide array of real economic variables in the US in a unifying model. By employing the non-linear factor-augmented vector autoregressive (FAVAR) model with simulation methods, we could trace the effects of exchange rate appreciation and depreciation on a wide array of macroeconomic variables through the impulse response function (IRF). The main findings are: (1) In response to dollar depreciation, import price index (IMP), producer price index (PPI) and CPI increase significantly. The pass-through ratio declines along the distribution chain. (2) Merchandise trade balance, current account balance and output improve facing dollar depreciation. (3) Savings decreases in response to dollar depreciation. (4) Employment and average hourly earnings increase in times of exchange rate depreciation and vice versa. The effects on macroeconomy from appreciation and depreciation seem symmetric. Many other interesting findings are also documented
A Computer Simulation Research of Two Types of Cardiac Physiological Pacing
This manuscript adopted the cardiac modeling and simulation method to study the problems of physiological pacing in clinical application. A multiscale rabbit ventricular electrophysiological model was constructed. We simulated His-bundle pacing (HBP) treatment for left bundle branch block (LBBB) and atrioventricular block (AVB), and left bundle branch pacing (LBBP) treatment for LBBB by setting various moments of the stimulus. The synthetic ECGs and detailed electrical activities were analyzed. Our electrophysiological model accurately simulated the normal state, HBP, and LBBP. The synthetic ECG showed that QRS duration was narrowed by 30% after HBP correction for LBBB. For LBBB correction with LBBP, the synthetic ECGs of LBBP starting before 30 ms (if the end of atrial excitation is set as 0 ms) presented right bundle branch block (RBBB), and those of LBBP starting at 30–38 ms were synchronous, while those of LBBP starting after 42 ms possessed LBBB morphologies. The best pacing results were obtained when LBBP started at 34 ms. This manuscript verified the feasibility of the constructed ventricular model, and studied the physiological pacing mechanism. The results showed that HBP realized correction for AVB and high LBBB. The performance of LBBP can be improved by applying the stimulus within a specific period of time (0–8 ms) after atrial excitation
Effects of Increased Extracellular Potassium Concentration Induced by Ischemia on the Vulnerability of Ventricular Arrhythmias and the Regularity of Related Ventricular Tachycardia
Myocardial ischemia could induce arrhythmias such as ventricular tachycardia and ventricular fibrillation, leading to sudden death and other serious consequences. This manuscript adopted the cardiac modeling and simulation method to study the activity pattern of myocardial ischemia-related ventricular tachycardia and the effect of increased extracellular potassium concentration on arrhythmia vulnerability. A whole ventricular electrophysiological model of endocardial ischemia caused by distal occlusion of left anterior descending coronary artery was established. The simulation results suggested that the relationship between the vulnerability of ventricular arrhythmias and extracellular potassium concentration was bell shaped with a peak in susceptibility at 12 mM. This result was caused by the effect of extracellular potassium concentration on the dispersion of repolarization and the effective refractory period of cardiomyocytes. The extension of the effective refractory period was due to the electrical remodeling of the ventricle. Specifically, it was because of the delayed recovery of the INa current. In addition, the regularity of endocardial/epicardial reentrant pattern during non-transmural ischemia was also analyzed. The endocardium formed micro-reentrant, while the epicardium established macro-reentrant rotating around the ischemic regions provided a new idea for the determination of clinical ablation targets
Effects of Acetic Acid on Growth and Lipid Production by Cryptococcus albidus
The cell growth and lipid accumulation process of Cryptococcus albidus were investigated using acetic acid as the sole carbon source at different concentrations. C. albidus showed high tolerance to acetic acid at a high concentration of 30 g L-1. The highest lipid content (32.69 +/- A 0.50 %) and lipid yield (0.96 +/- A 0.05 g L-1) were both obtained in the medium with an initial acetic acid concentration of 30 g L-1 on day five. Interestingly, the maximum lipid content and lipid yield was obtained on a different day in a medium with different acetic acid concentration. The fatty acid composition of the lipids accumulated by C. albidus was 16-23 % palmitic acid (C16:0), 3-5 % linolenic acid (C18:3), 42-51 % linoleic acid (C18:2) and 23-27 % oleic acid (C18:1), which was similar to that of soybean oil; thus, this microbial oil has great potential value as a renewable biodiesel feedstock. This work also provides valuable information for further research to use cheap substrates containing a high concentration of acetic acid (such as lignocellulosic hydrolysates), which is an economical and environmentally friendly form of microbial oil production
Circ_0001602 aggravates the progression of acute myeloid leukemia by regulating the miR-192-5p/ZBTB20 axis
ABSTRACTBackground Acute myeloid leukemia (AML) is a malignant blood cancer with a poor prognosis and complex pathogenesis. Recently, the critical role of circular RNAs (circRNAs) has been demonstrated in the malignant progression of AML. This study aimed to investigate the functional role and underlying mechanism of circ_0001602 in AML development.Methods Quantitative real-time polymerase chain reaction (qRT-PCR) assay was conducted for detecting the expression of circ_0001602, CCND3, microRNA-192-5p (miR-192-5p), and Zinc Finger and BTB Domain-Containing Protein 20 (ZBTB20) mRNA. RNase R assay and Actinomycin D assay were implemented to determine the characteristics of circ_0001602. Cell counting Kit-8 (CCK-8) assay was performed to evaluate cell proliferation. Flow cytometry was employed for assessing cell cycle distribution and apoptosis. Dual-luciferase reporter assay and RIP assay were utilized for confirming the interactions between miR-192-5p and circ_0001602 or ZBTB20.Results Circ_0001602 and ZBTB20 were upregulated and miR-192-5p level was reduced in AML tissues and cells. Depletion of circ_0001602 repressed cell proliferation and induced cell cycle arrest and apoptosis in AML cells. Functionally, circ_0001602 was identified to be the sponge of miR-192-5p, and miR-192-5p silence restored the suppressive effects of circ_0001602 knockdown on AML cell progression. Furthermore, ZBTB20 was a target of miR-192-5p, and ZBTB20 overexpression neutralized the miR-192-5p-mediated inhibiting actions on the malignant phenotypes of AML cells. Besides, circ_0001602 could sponge miR-192-5p to positively regulate ZBTB20 expression.Conclusion Circ_0001602 contributed to AML cell development at least partially through modulating the miR-192-5p/ZBTB20 axis, which provided new insights for AML treatment
A novel electrochemiluminescence glucose biosensor based on platinum nanoflowers/graphene oxide/glucose oxidase modified glassy carbon electrode
A novel electrochemiluminescence (ECL) biosensor based on platinum nanoflowers (PtNFs)/graphene oxide (GO)/glucose oxidase (GODx) was discovered for glucose detection. PtNFs/GO was synthesized using a nontoxic, rapid, one-pot and template-free method and characterized by transmission electron microscopy (TEM) and high-resolution TEM techniques. The as-prepared PtNFs/GO with clean surface and multiporous structure was used to assemble GODx to form a glucose biosensor. Based on ECL results, the PtNFs/GO/GODx film-modified electrode displayed a high electrocatalytic activity towards the oxidation of glucose, which generated hydrogen peroxide (H2O2) to react with the luminol radicals thus enhanced the luminol ECL. Under the optimized conditions, two linear regions of ECL intensity to glucose concentration were valid in the range from 5 to 80 μmol/L (r=0.9957) and 80 to 1,000 μmol/L (r=0.9909) with a detection limit (S/N=3) of 2.8 μmol/L. In order to verify the reliability, the thus-fabricated biosensor was applied to determine the glucose concentration in glucose injection, glucose functional drink, and blood serum. The results indicated that the proposed biosensor presented good characteristics in terms of high sensitivity and good reproducibility for glucose determination, promising the applicability of this sensor in practical analysis. ? 2014 Springer-Verlag Berlin Heidelberg
A novel electrochemiluminescence tetracyclines sensor based on a Ru(bpy)32+-doped silica nanoparticles/Nafion film modified electrode
A novel method for the determination of tetracyclines (TCs) using electrochemiluminescence (ECL) based on a Ru(bpy)32+-doped silica nanoparticles (RuSiNPs)/Nafion film modified electrode is presented in this paper. The RuSiNPs were prepared by a water-in-oil microemulsion method. The characterization results indicated that the thus-prepared RuSiNPs presented a uniform size of 45 nm and retained the original electrochemical properties of Ru(bpy)32+. Importantly, the ECL response on RuSiNPs/Nafion film modified electrode was greatly enhanced by TCs. Under the optimum conditions, the ECL intensity versus the concentration of TCs was found to be linear over the range of 1-100 μmol L-1 for tetracycline (TC), 0.1-100 μmol L-1 for oxytetracycline (OTC) and 1-100 μmol L-1 for chlortetracycline (CTC). The detection limits (S/N=3) were 0.23 μmol L-1 for TC, 0.10 μmol L-1 for OTC and 0.16 μmol L-1 for CTC. Moreover, due to the electrostatic interaction between Ru(bpy)32+ and silica matrix, the leaching of Ru(bpy)32+ was greatly reduced, therefore, the ECL sensor exhibited excellent repeatability and stability in the detection of TCs. Based on these investigations, the proposed ECL approach was successfully used to analyze the TCs content in drugs. ? 2014 Elsevier B.V
- …