251 research outputs found
Airborne in situ vertical profiling of HDO/H₂¹⁶O in the subtropical troposphere during the MUSICA remote sensing validation campaign
Vertical profiles of water vapor (H2O) and its isotope ratio D/H expressed as δD(H2O) were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of δ(δD) ≈10‰. Vertical profiles between 150 and ∼7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote sensing measurements of δD(H2O) as a means to validate the remote sensing humidity and δD(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and δD(H2O) correlations we were able to identify different layers of air masses with specific isotopic signatures. The results are discussed. © Author(s) 2015
PVA-Based Nanofibers Containing Chitosan Modified with Graphene Oxide and Carbon Quantum Dot-Doped TiO2 Enhance Wound Healing in a Rat Model
Electrospun nanofibrous constructs based on nanoparticles and biopolymers have recently been used in tissue engineering because of their similarity to the extracellular matrix in nature. In this study, electrospun chitosan-carbon quantum dot-titanium dioxide-graphene oxide (CS-CQD-TiO2-GO) nanofibrous mats were synthesized for use as wound dressings by the electrospinning method. To increase the biodegradation rate and water resistance, the fabricated nanofibrous mats were cross-linked. SEM images showed a uniform and coherent structure of CS-CQD-TiO2-GO nanocomposites and CS-CQD-TiO2-GO electrospun nanofibers mats. FTIR analysis, XRD pattern, SEM mapping, and EDS spectrum demonstrate the accuracy of the synthesis as well as the elemental and chemical structure of the nanofibrous mat. The water contact angle indicated that the nanofibrous mat had a hydrophilic property, which is essential for controlling wound exudates. The tensile strength and elongation tests showed that the nanofibrous mat has suitable mechanical properties for wound dressing, including significant flexibility and strength. Interestingly, antimicrobial testing illustrated that the fabricated nanofibrous mat had antibacterial activity against Gram-negative and Gram-positive bacteria. Appropriate cell viability and cytocompatibility of treated mouse fibroblast NIH3T3 cells with the nanofibrous mat were determined using an MTT assay. The animal study results confirmed the proper potential of the nanofibrous mat in wound dressing applications
Airborne in situ vertical profiling of HDO/H₂¹6O in the subtropical troposphere during the MUSICA remote sensing validation campaign
Vertical profiles of water vapor (H2O) and its isotope ratio D / H expressed as delta D(H2O were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of Delta(delta D) ~10‰. Vertical profiles between 150 and ~7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote-sensing measurements of delta D(H2O) as a means to validate the remote sensing humidity and delta D(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and delta D(H2O) correlations we were able to identify different layers of airmasses with specific isotopic signatures. The results are discussed
Airborne in situ vertical profiling of HDO / H216O in the subtropical troposphere during the MUSICA remote sensing validation campaign
Vertical profiles of water vapor (H2O) and its isotope ratio D / H expressed as δD(H2O) were measured in situ by the ISOWAT II diode-laser spectrometer during the MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water (MUSICA) airborne campaign. We present recent modifications of the instrument design. The instrument calibration on the ground as well as in flight is described. Based on the calibration measurements, the humidity-dependent uncertainty of our airborne data is determined. For the majority of the airborne data we achieved an accuracy (uncertainty of the mean) of Δ(δD) ≈10‰. Vertical profiles between 150 and ~7000 m were obtained during 7 days in July and August 2013 over the subtropical North Atlantic Ocean near Tenerife. The flights were coordinated with ground-based (Network for the Detection of Atmospheric Composition Change, NDACC) and space-based (Infrared Atmospheric Sounding Interferometer, IASI) FTIR remote sensing measurements of δD(H2O) as a means to validate the remote sensing humidity and δD(H2O) data products. The results of the validation are presented in detail in a separate paper (Schneider et al., 2014). The profiles were obtained with a high vertical resolution of around 3 m. By analyzing humidity and δD(H2O) correlations we were able to identify different layers of air masses with specific isotopic signatures. The results are discussed.The MUSICA airborne mission was funded in part by the European Research Council under the European Community’s Seventh Framework Programme (FP7/2007-2013)/ERC grant agreement no. 256961
Excitable media in open and closed chaotic flows
We investigate the response of an excitable medium to a localized
perturbation in the presence of a two-dimensional smooth chaotic flow. Two
distinct types of flows are numerically considered: open and closed. For both
of them three distinct regimes are found, depending on the relative strengths
of the stirring and the rate of the excitable reaction. In order to clarify and
understand the role of the many competing mechanisms present, simplified models
of the process are introduced. They are one-dimensional baker-map models for
the flow and a one-dimensional approximation for the transverse profile of the
filaments.Comment: 14 pages, 16 figure
The predictors of no-reflow phenomenon after primary angioplasty for acute myocardial infarction
Background: No-reflow phenomenon is a serious complication of primary Percutaneous Coronary Intervention (PCI), which may increase the risk of progressive myocardial damage, profound left ventricular dysfunction, and death. Objectives: This study aimed to investigate the incidence of no-reflow phenomenon and its clinical, para-clinical, and angiographic determinants in patients who underwent primary PCI for ST Elevation Myocardial Infarction (STEMI). Patients and Methods: This non-randomized prospective cohort study was conducted on 397 patients in a cardiovascular tertiary care center in Tehran, Iran from April 2012 to April 2014. The inclusion criteria of the study were presenting with acute STEMI of � 12 h duration or having admitted between 12 and 24 hours after onset with symptoms and signs of ongoing ischemia. The participants underwent standard coronary angiography. No-reflow phenomenon was defined as a Thrombolysis In Myocardial Infarction (TIMI) flow � 2 and no presence of spasm, distal embolization, or dissection after completion of the procedure. The association between no-reflow and its determinants was assessed by chi-square, student�s t-test, or Mann�Whitney U test. Logistic regression models were also used for multivariate analysis. P values < 0.05 were considered to be statistically significant. Results: The participants� mean (SD) age was of 59 (12.2) years and female/male ratio was 83/314. The incidence of no-reflow phenomenon was 63 (15.9). Besides, the results of multivariate analysis showed that only thrombus burden, lesion length, time to reperfusion, and type of occlusion had an adjusted association with this phenomenon. Conclusions: The study results suggested that no-reflow phenomenon after primary PCI would be predictable. Thus, preventive measures, such as using distal protective devices or administration of platelet glycoprotein IIb/IIIa antagonists, are advised to be used in high-risk patients. © 2016, Iranian Cardiovascular Research Journal. All rights reserved
Lattice instabilities of cubic NiTi from first principles
The phonon dispersion relation of NiTi in the simple cubic B2 structure is
computed using first-principles density-functional perturbation theory with
pseudopotentials and a plane-wave basis set. Lattice instabilities are observed
to occur across nearly the entire Brillouin zone, excluding three
interpenetrating tubes of stability along the (001) directions and small
spheres of stability centered at R. The strongest instability is that of the
doubly degenerate M5' mode. The atomic displacements of one of the eigenvectors
of this mode generate a good approximation to the observed B19' ground-state
structure.Comment: 11 pages, 3 figure
Comparing the cardiac MRI and thallium-201 SPECT findings in assessing myocardial viability in patients with ST elevation myocardial infarction
Background and purpose: Viable tissue detection after STEMI can lead to successful revascularization for reversing myocardial dysfunction. The purpose of this study was to compare the Thallium-201 SPECT and MRI findings in viability assessment. Materials and methods: A cross-sectional study was performed on 17 patients with STEMI. In addition to Thallium SPECT, contrast enhanced MRI imaging was done. Viability was determined as more than 50 percent thallium uptake after 4 hours in SPECT and lower than 50 percent gadolinium enhancement after 10 minutes in each segments in CMRI. Results: Two hundred eighty nine segments were studied using both methods. TL SPECT showed 15.6 of the segments as non-viable tissue while MRI showed 35 non-viable tissue. There was a substantial agreement between these methods in apical septal and apical segments (k: 0.653, k: 0.757, respectively). Conclusion: The percentage of non-viable myocardium in MRI was found to be higher than that of Thallium SPECT and also considerable agreement was seen between MRI and Thallium SPECT in determination of myocard viability in apical septal and apex segments. © 2016, Mazandaran University of Medical Sciences. All rights reserved
Correction to: Clopidogrel Pharmacogenetics in Iranian Patients Undergoing Percutaneous Coronary Intervention (Cardiovascular Toxicology, (2018), 10.1007/s12012-018-9459-x)
The original version of this article unfortunately contained a typo in the co-author name. © 2018, Springer Science+Business Media, LLC, part of Springer Nature
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