Experimental investigation of flame spreading over pure methane hydrate in a laminar boundary layer

Flame spreading over pure methane hydrate in a laminar boundary layer is investigated experimentally. The free stream velocity (U_∞) was set constant at 0.4 m/s and the surface temperature of the hydrate at the ignition (T_s) was varied between ?10 and ?80 °C. Hydrate particle sizes were smaller than 0.5 mm. Two types of flame spreading were observed; “low speed flame spreading” and “high speed flame spreading”. The low speed flame spreading was observed at low temperature conditions (T_s = ?80 to ?60 °C) and temperatures in which anomalous self-preservation took place (T_s = ?30 to ?10 °C). In this case, the heat transfer from the leading flame edge to the hydrate surface plays a key role for flame spreading. The high speed flame spreading was observed when T_s = ?50 and ?40 °C. At these temperatures, the dissociation of hydrate took place and the methane gas was released from the hydrate to form a thin mixed layer of methane and air with a high concentration gradient over the hydrate. The leading flame edge spread in this premixed gas at a spread speed much higher than laminar burning velocity, mainly due to the effect of burnt gas expansion.     

Interaction of dioxouranium(VI) ion with EDTA at different ionic strengths

The formation of complex species of dioxouranium(VI) ion with EDTA was studied in the pH range of 1–3.5 and at 25 °C using a combination of potentiometric and spectrophotometric techniques. Results showed evidence for formation of the following species: [UO₂H₄EDTA]²⁺, [UO₂H₃EDTA]⁺, and [UO₂H₂EDTA]. Investigations were performed in sodium perchlorate as background electrolyte at 0.1, 0.3, 0.5, 0.7, and 1.0 mol dm^? 3. The parameters based on the formation constants were calculated, and the dependences of protonation and the stability constants on ionic strength are described. The dependence on ionic strength of the formation constants was analyzed using the specific ion interaction theory (SIT) model. The stability constant values at infinite dilution, obtained using SIT model, are log β°₁₄₁ = 6.77, log β°₁₃₁ = 5.99 and log β°₁₂₁ = 9.29, where indexes for the overall stability constant, β_pqr, refer to the equilibrium pUO₂²⁺ + qH⁺ + rL^4? ? M_pH_qL_r^{(2p + q ? 4r)}. The specific interaction coefficients are also reported.     

Transverse relaxation of cerebrospinal fluid depends on glucose concentration

PurposeTo evaluate the biophysical processes that generate specific T₂ values and their relationship to specific cerebrospinal fluid (CSF) content.Materials and methodsCSF T_2s were measured ex vivo (14.1 T) from isolated CSF collected from human, rat and non-human primate. CSF T_2s were also measured in vivo at different field strength in human (3 and 7 T) and rodent (1, 4.7, 9,4 and 11.7 T) using different pulse sequences. Then, relaxivities of CSF constituents were measured, in vitro, to determine the major molecule responsible for shortening CSF T₂ (2 s) compared to saline T₂ (3 s). The impact of this major molecule on CSF T₂ was then validated in rodent, in vivo, by the simultaneous measurement of the major molecule concentration and CSF T₂.ResultsEx vivo CSF T₂ was about 2.0 s at 14.1 T for all species. In vivo human CSF T₂ approached ex vivo values at 3 T (2.0 s) but was significantly shorter at 7 T (0.9 s). In vivo rodent CSF T₂ decreased with increasing magnetic field and T₂ values similar to the in vitro ones were reached at 1 T (1.6 s). Glucose had the largest contribution of shortening CSF T₂ in vitro. This result was validated in rodent in vivo, showing that an acute change in CSF glucose by infusion of glucose into the blood, can be monitored via changes in CSF T₂ values.ConclusionThis study opens the possibility of monitoring glucose regulation of CSF at the resolution of MRI by quantitating T₂.     

Recovery of accurate T2 from historical 1.5 tesla proton density and T2-weighted images: Application to 7-year T2 changes in multiple sclerosis brain

ObjectiveTo determine accurate quantitative transverse relaxation times (T₂) using retrospective clinical images and apply it to examine 7-year changes in multiple sclerosis (MS) brain.MethodsA method for T₂ mapping from retrospective proton density (PD) and T₂-weighted fast spin echo images was recently introduced, but requires measurement of flip angles. We examined whether 1.5 T flip angle variation in brain can be predicted, thus enabling T₂ analysis of historical PD and T₂-weighted images without a concurrent flip angle map. After method validation in healthy volunteers, retrospective longitudinal T₂ analysis was performed in 14 MS subjects over seven years. Changes in patient T₂ values were compared with brain atrophy, T₂ lesion load and disability score in MS.ResultsSimilar flip angle maps across volunteers enabled retrospective T₂ from PD and T₂-weighted images even when different refocusing angles were used. Over seven years, significant T₂ changes of 2–4% were observed when using T₂ modelling and the 7-year effect size for globus pallidus T₂ was 0.56, which was more significant than brain atrophy. No significant T₂ results were found when using exponential fit, which cannot account for refocusing angle variation. Moreover, change is T₂ in globus pallidus and internal capsule correlated with MS disability score over time when using T₂ modelling.ConclusionsAccurate quantitative T₂ can be extracted from standard clinical 1.5 T MRI exams that include PD and T₂-weighted imaging even when no flip angle map is available. This method was applied retrospectively to examine seven year changes in MS.     

Formation of nickel and nickel,zinc-bearing ferrite in aqueous suspension by air oxidation

Stoichiometric Ni-bearing ferrite was formed by air oxidation of an iron(II) hydroxide suspension at an initial Ni : Fe_tot mol ratio (r_Ni) of 0.20 : 2.80 at pH 10.0 and 65°C. Most of products formed at r_Ni=0.40 : 2.60 and 0.60 : 2.40 were Ni-bearing ferrites, of which vacancies of Fe³⁺ ion on the lattice points may be considered. Only Ni, Zn-bearing ferrites were formed in the suspensions at initial (Ni + Zn)  : Fe_tot mol ratios (r_{Ni + Zn}) of 0.20 : 2.80–0.60 : 2.40 at pH 10.0 and 65°C. At higher r_Ni or r_{Ni + Zn} by-products containing Ni, Fe and O₄²⁻ were formed. The formation of the by-products was depressed in the suspensions containing chloride ions in the place of sulfate ions.     

Clinical feasibility of 3D-QALAS – Single breath-hold 3D myocardial T1- and T2-mapping

PurposeTo investigate the in-vivo precision and clinical feasibility of 3D-QALAS - a novel method for simultaneous three-dimensional myocardial T1- and T2-mapping.MethodsTen healthy subjects and 23 patients with different cardiac pathologies underwent cardiovascular 3 T MRI examinations including 3D-QALAS, MOLLI and T2-GraSE acquisitions. Precision was investigated in the healthy subjects between independent scans, between dependent scans and as standard deviation of consecutive scans. Clinical feasibility of 3D-QALAS was investigated for native and contrast enhanced myocardium in patients. Data were analyzed using mean value and 95% confidence interval, Pearson correlation, Paired t-tests, intraclass correlation and Bland-Altman analysis.ResultsAverage myocardial relaxation time values and SD from eight repeated acquisitions within the group of healthy subjects were 1178 ± 18.5 ms (1.6%) for T1 with 3D-QALAS, 52.7 ± 1.2 ms (2.3%) for T2 with 3D-QALAS, 1145 ± 10.0 ms (0.9%) for T1 with MOLLI and 49.2 ± 0.8 ms (1.6%) for T2 with GraSE.Myocardial T1 and T2 relaxation times obtained with 3D-QALAS correlated very well with reference methods; MOLLI for T1 (r = 0.994) and T2-GraSE for T2 (r = 0.818) in the 23 patients. Average native/post-contrast myocardial T1 values from the patients were 1166.2 ms/411.8 ms for 3D-QALAS and 1174.4 ms/438.9 ms for MOLLI. Average native myocardial T2 values from the patients were 53.2 ms for 3D-QALAS and 54.4 ms for T2-GraSE.ConclusionsRepeated independent and dependent scans together with the intra-scan repeatability, demonstrated all a very good precision for the 3D-QALAS method in healthy volunteers. This study shows that 3D T1 and T2 mapping in the left ventricle is feasible in one breath hold for patients with different cardiac pathologies using 3D-QALAS.     

Studies on the optical and mechanical properties of non-linear optical 3-aminophenol orthophosphoric acid (3-amphph) single crystal

Single crystals of semiorganic material 3-aminophenol orthophosphoric acid (denoted as 3-amphph) of size 29 × 17 × 4 mm³ have been grown by the slow evaporation of an aqueous solution of deionized water at 50 °C. The crystal belongs to orthorhombic system with the non centrosymmetric space group P2₁2₁2₁. The lattice parameter values of 3-amphph crystal are a = 4.481(2) Å, b = 9.782(4) Å and c = 18.326(4) Å. The grown crystals are subjected to single crystal XRD studies to identify its morphology and structure. Optical transmittance and second harmonic generation of the grown crystals have been studied by UV–Vis–NIR spectrum and Kurtz powder technique respectively. The transmittance of 3-amphph crystal has been used to calculate the refractive index n, the extinction coefficient k, reflectance R and both the real (?_r) and imaginary (?_i) components of the dielectric constant as a function of wavelength. The optical band gap of 3-amphph is 4.05 eV with direct transition. The anisotropic mechanical behavior of 3-amphph has been analyzed using Vickers microhardness test. The mechanism of growth is revealed by carrying out chemical etching using water as etchant.     

The improvement in dielectric and ferroelectric performance of PZT–PZN ceramics by thermal treatment

Pyrochlore-free lead zirconate titanate – lead zinc niobate ceramics have been systematically investigated in the as-sintered condition as well as after annealing. The ceramics were characterized by dielectric spectroscopy and Sawyer–Tower polarization (P–E) measurements. The powders of Pb[(Zr_1/2Ti_1/2)_(1−x)–(Zn_1/3Nb_2/3)_x]O₃, where x = 0.1, 0.3 and 0.5 were prepared using the columbite–(wolframite) precursor method. The general trend seems to indicate that the annealed samples become more normal-ferroelectric-like behavior as opposed to the relaxor-ferroelectric-like behavior observed in the as-sintered state. The as-sintered 0.9PZT–0.1PZN ceramic exhibited weak relaxor-ferroelectric behavior, with a relatively low dielectric constant maximum of 14,000 measured at 1 kHz. Annealing resulted in a transition to normal-ferroelectric-like behavior, a shift in the dielectric maximum temperature from 360 °C to 350 °C, and a dramatic increase in the dielectric constant at 1 kHz to a maximum value of 35,000 for the longer anneal. After thermal annealing at 900 °C for one week a strong enhancement of remanent polarization (P_r) was observed.     

Flow versus permeability weighting in estimating the forward volumetric transfer constant (Ktrans) obtained by DCE-MRI with contrast agents of differing molecular sizes

PurposeTo quantify the differential plasma flow- (F_p-) and permeability surface area product per unit mass of tissue- (PS-) weighting in forward volumetric transfer constant (K^trans) estimates by using a low molecular (Gd-DTPA) versus high molecular (Gadomer) weight contrast agent in dynamic contrast enhanced (DCE) MRI.Materials and methodsDCE MRI was performed using a 7T animal scanner in 14 C57BL/6J mice syngeneic for TRAMP tumors, by administering Gd-DTPA (0.9 kD) in eight mice and Gadomer (35 kD) in the remainder. The acquisition time was 10 min with a sampling rate of one image every 2 s. Pharmacokinetic modeling was performed to obtain K^trans by using Extended Tofts model (ETM). In addition, the adiabatic approximation to the tissue homogeneity (AATH) model was employed to obtain the relative contributions of F_p and PS.ResultsThe K^trans values derived from DCE-MRI with Gd-DTPA showed significant correlations with both PS (r² = 0.64, p = 0.009) and F_p (r² = 0.57, p = 0.016), whereas those with Gadomer were found only significantly correlated with PS (r² = 0.96, p = 0.0003) but not with F_p (r² = 0.34, p = 0.111). A voxel-based analysis showed that K^trans approximated PS (< 30% difference) in 78.3% of perfused tumor volume for Gadomer, but only 37.3% for Gd-DTPA.ConclusionsThe differential contributions of F_p and PS in estimating K^trans values vary with the molecular weight of the contrast agent used. The macromolecular contrast agent resulted in K^trans values that were much less dependent on flow. These findings support the use of macromolecular contrast agents for estimating tumor vessel permeability with DCE-MRI.     

Effects of ultrasound and temperature on copper electro reduction in Deep Eutectic Solvents (DES)

This paper concerns a preliminary study for a new copper recovery process from ionic solvent. The aim of this work is to study the reduction of copper in Deep Eutectic Solvent (choline chloride–ethylene glycol) and to compare the influence of temperature and the ultrasound effects on kinetic parameters. Solutions were prepared by dissolution of chloride copper salt CuCl₂ (to obtain Copper in oxidation degree II) or CuCl (to obtain Copper in oxidation degree I) and by leaching metallic copper directly in DES. The spectrophotometry UV–visible analysis of the leached solution showed that the copper soluble form obtained is at oxidation degree I (Copper I). Both cyclic voltammetry and linear voltammetry were performed in the three solutions at three temperatures (25, 50 and 80 °C) and under ultrasonic conditions (F = 20 kHz, PT = 5.8 W) to calculate the mass transfer diffusion coefficient kD and the standard rate coefficient k°. These parameters are used to determine that copper reduction is carried out via a mixed kinetic-diffusion control process. Temperature and ultrasound have the same effect on mass transfer for reduction of Cu^II/Cu^I. On the other hand, temperature is more beneficial than ultrasound for mass transfer of Cu^I/Cu. Standard rate constant improvement due to temperature increase is of the same order as that obtained with ultrasound. But, by combining higher temperature and ultrasound (F = 20 kHz, PT = 5.6 W at 50 °C), reduction limiting current is increased by a factor of 10 compared to initial conditions (T = 25 °C, silent), because ultrasonic stirring is more efficient in lower viscosity fluid. These values can be considered as key-parameters in the design of copper recovery in global processes using ultrasound.     

The prognostic value of proton magnetic resonance spectroscopy in term newborns treated with therapeutic hypothermia following asphyxia

ObjectiveThe purpose of this study was to correlate brain metabolism assessed shortly after therapeutic hyperthermia by ¹H magnetic resonance spectroscopy (MRS), with neurodevelopmental outcome.MethodsAt the age of 6.0 ± 1.8 days, brain metabolites of 35 term asphyxiated newborns, treated with therapeutic hypothermia, were quantified by multivoxel proton MRS of a volume cranial to the corpus callosum, containing both gray and white matter. At the age of 30 months the Bayley Scale of Infant Development-III was performed.ResultsInfants that died had lower gray matter NAA levels than infants that survived (P = 0.005). In surviving infants (28 of 35) there was a trend of negative correlation between gray matter choline levels and gross motor outcome (r = − 0.45). In the white matter, choline correlated negatively with fine motor skills (r = − 0.40), and creatine positively with gross motor skills (r = 0.58, P = 0.02). There was no relationship between lactate levels and outcome.ConclusionMRS of asphyxiated neonates treated by therapeutic hypothermia can serve as predictor of outcome. Unlike previously reported associations in untreated asphyxiates, lactate levels had no relationship with outcome, which indicates that one of the working mechanisms of therapeutic hypothermia is reduction of the metabolic rate.     

Synthesis,crystal growth and characterization of a semiorganic material: Calcium dibromide bis(glycine) tetrahydrate

Single crystals of semiorganic material calcium dibromide bis(glycine) tetrahydrate were grown from aqueous solution. The crystal belongs to monoclinic system, with a = 13.261(5) Å, b = 6.792(2) Å, c = 15.671(9) Å and β = 91.68(4)°. The presence of the elements in the title compound was confirmed by energy dispersive X-ray analysis. The solubility and metastable zone width were found. The grown crystals were tested by powder XRD, FTIR, Thermo Gravimetric and Differential Thermal Analysis, UV–vis–NIR analysis, dielectrical and mechanical studies. The transmittance of calcium dibromide bis(glycine) tetrahydrate crystal has been used to calculate the refractive index n, the extinction coefficient K and both the real ɛ_r and imaginary ɛ_i components of the dielectric constant as functions of wavelength. The optical band gap of calcium dibromide bis(glycine) tetrahydrate is 3.23 eV.     

Dependence of the AES backscattering correction factor on the experimental configuration

We present an analysis of the dependence of the backscattering correction factor (BCF) in Auger-electron spectroscopy (AES) on the analyzer acceptance angle. Illustrative BCF calculations are presented for Pd M₅N₄₅N₄₅ Auger electrons as a function of primary-electron energy for primary-electron angles of incidence, θ₀, of 0° and 80° and for various values of the analyzer acceptance angle. It was necessary to generalize the BCF definition for the case of an analyzer with an arbitrarily large acceptance angle; this was done with a new function, the integral emission depth distribution function. BCFs calculated from an advanced model of electron transport in the surface region of the Pd sample varied weakly with analyzer half-cone angle for θ₀ = 0° but more strongly for θ₀ = 80° where there were BCF differences varying between 19% at a primary energy of 1 keV and 6% at a primary energy of 5 keV. These BCF differences are due in part to variations of the BCF with emission angle and in part to variations of the density of inner-shell ionizations within the information depth for the detected Auger electrons. The latter variations are responsible for differences larger than 10% between BCFs from the widely used simplified BCF model and those from the more accurate advanced model for primary energies less than about 5 keV for θ₀ = 80°. For normal incidence of the primary beam, differences greater than 10% between BCFs from the simplified and advanced models were found for primary energies between 1 keV and 4 keV. These BCF differences indicate that the simplified model can provide only approximate BCF values. In addition, the simplified model does not provide any BCF dependence on Auger-electron emission angle or analyzer acceptance angle.     

Phase errors in FSE signals due to low frequency electromagnetic interference

ObjectiveTo quantitatively evaluate induced phase errors in fast spin echo (FSE) signals due to low frequency electromagnetic inference (EMI).MethodsSpecific form of Bloch equation is numerically solved in time domain for two different FSE pulse sequences (ETL = 8) with two different bandwidths. A single spin is modeled at x = 10 cm, EMI frequencies are simulated from 1 to 1000 Hz and phase errors at different echo times are calculated.ResultsPhase errors in the received echo signals induced by EMI are significantly higher at low frequencies (< 200 Hz) than at high frequencies and the phase errors at low frequencies can be effectively reduced by using high receiving bandwidth.ConclusionPulse sequence bandwidth can be used to control the phase errors in the FSE signals due to low frequency EMI.     

Combined effect of ultrasound,heat, and pressure on Escherichia coli O157:H7, polyphenol oxidase activity,and anthocyanins in blueberry (Vaccinium corymbosum) juice

The objective of this study was to evaluate the effect of different treatments—heat treatment (HT), sonication (SC), thermosonication (TS), manosonication (MS), manothermal (MT), and manothermosonication (MTS) on Escherichia coli O157:H7, polyphenol oxidase (PPO), and anthocyanin content in blueberry juice. First, samples were treated at different temperatures (30, 40, 50, 60, 70, and 80 °C) and power intensities (280, 420, 560, and 700 W) for 10 min. Subsequently, samples were treated using combinations of power intensity and mild temperature for 10 min. For further study, samples were treated using HT (80 °C), TS (40 °C, 560 W), MT (350 MPa, 40 °C), MS (560 W, 5 min/350 MPa), or MTS (560 W, 5 min, 40 °C/350 MPa, 40 °C) for 5, 10, 15, 20 min for each treatment, and the results compared between treatments. HT significantly reduced PPO activation (2.05% residual activity after only 5 min), and resulted in a 2.00-log reduction in E. coli O157:H7 and an 85.25% retention of anthocyanin. Escherichia coli O157:H7 was slightly inactivated by TS after 5 min (0.17-log reduction), while residual PPO activity was 23.36% and anthocyanin retention was 98.48%. However, Escherichia coli O157:H7 was rapidly inactivated by MTS (5.85-log reduction) after 5 min, while anthocyanin retention was 97.49% and residual PPO activity dropped to 10.91%. The destruction of E. coli cells as a result of these treatments were confirmed using SEM and TEM. Therefore, a combination of sonication, high pressure, and mild heat allows the safety of blueberry juice to be maintained without compromising the retention of desirable antioxidant compounds.     

Assessment of MRI issues for a new cerebral spinal fluid shunt,gravitational valve (GV)

PurposeA gravitational valve (GV) may be used to treat hydrocephalus, offering possible advantages that include avoidance of over drainage and long-term complications. Because a GV is made from metal, there are potential safety and other problems related to the use of MRI. The objective of this investigation was to evaluate MRI-related issues (i.e., magnetic field interactions, heating, and artifacts) for a newly developed, metallic GV.MethodsTests were performed on the GV (GAV 2.0) using well-accepted techniques to assess magnetic field interactions (translational attraction and torque, 3-Tesla), MRI-related heating (1.5-T/64-MH and 3-T/128-MHz, whole body averaged SAR, 2.7-W/kg and 2.9-W/kg, respectively), artifacts (3-Tesla; gradient echo and T1-weighted, spin echo sequences), and possible functional changes related to exposures to different MRI conditions (exposing six samples each to eight different pulse sequences at 1.5-T/64-MHz and 3-T/128-MHz).ResultsMagnetic field interactions were not substantial (deflection angle 2°, no torque) and heating was minor (highest temperature rise, ≥ 1.9 °C, highest background temperature rise, ≥ 1.7 °C). Artifacts on the gradient echo pulse sequence extended approximately 10 mm from the size and shape of the GV. The different exposures to 1.5-T/64-MHz and 3-T/128-MHz conditions did not alter or damage the operational aspects of the GV samples.ConclusionsThe findings demonstrated that MRI can be safely used in patients with this GV and, thus, this metallic implant is deemed acceptable or “MR Conditional” (i.e., using current labeling terminology), according to the conditions used in this study.     

Phase formation and electrical properties of BNLT–BZT lead-free piezoelectric ceramic system

Phase formation study in lead-free piezoelectric ceramics based on lanthanum doped bismuth sodium titanate (Bi_0.4871Na_0.4871La_0.0172TiO₃:BNLT) and zirconium doped barium titanate (BaZr_0.05Ti_0.95O₃:BZT), has been carried out in the system of (1−x)BNLT–xBZT where x = 0.0–1.0, by two-step mixed oxide method. It was observed that the addition of BZT in the BNLT ceramics developed the dielectric and piezoelectric properties of the ceramics with the optimum piezoelectric constant (d₃₃) and dielectric constant (ε_r) at room temperature of about 138 pC/N and 1651, respectively, from the 0.2 BNLT to 0.8 BZT ceramic sample. The Curie temperature (T_C) of this ceramic was found at 295 °C which is 195 °C higher than that of pure BZT ceramics, promising the use of this ceramic in a higher range of temperature.     

Dielectric and ferroelectric properties of 0.8PZT–0.2PCN ceramics under sintering conditions variation

The influences of sintering conditions on electrical properties of the 0.8Pb(Zr_1/2Ti_1/2)O₃–0.2Pb(Co_1/3Nb_2/3)O₃ ceramics have been investigated with sintering temperatures of 1175, 1200, 1225, and 1250 °C and dwell times for 2, 6, and 10 h. The crystal structure of dense specimens showed coexistence between tetragonal, rhombohedral and pseudo cubic phases in all sintering temperatures, while tetragonal-rich phase appeared with increasing dwell times. A maximum dielectric constant was observed at sintering condition of 1200 °C for 2 h, while the transition temperature slightly increased with increasing dwell time. All ceramics also showed diffused phase transition behaviors with a minimum diffusivity at sintering condition of 1200 °C for 2 h. In addition, the polarization–electric field (P–E) hysteresis loops of the ceramic systems also changed significantly with sintering conditions. Interestingly, the ferroelectric parameters; remnant polarization (P_r) and loop squareness (R_sq) tended to increase with increasing sintering temperatures and dwell times.     

Mapping of left ventricle wall thickness in mice using 11.7-T magnetic resonance imaging

BackgroundThe left ventricle (LV) wall thickness is an important and routinely measured cardiologic parameter. Here we introduce three-dimensional (3D) mapping of LV wall thickness and function using a self-gated magnetic resonance (MR) sequence for ultra-high-field 11.7-T MR cine imaging of mouse hearts.Methods and resultsSix male C57BL/6-j mice were subjected to 11.7-T MR imaging (MRI). Three standard views—short axis, long axis four-chamber, and long axis two-chamber—and eight consecutive short axis scans from the apex to base were performed for each mouse. The resulting 11 self-gated cine images were used for fast low-angle shot analysis with a navigator echo over an observation period of approximately 35 min. The right ventricle (RV) and LV were identified in the short axis and four-chamber views. On 3D color-coded maps, the interventricular septum wall (diastole: 0.94 ± 0.05 mm, systole: 1.20 ± 0.09 mm) and LV free wall (diastole: 1.07 ± 0.15 mm, systole: 1.79 ± 0.11 mm) thicknesses were measured.ConclusionThis 3D wall thickness mapping technique can be used to observe regional wall thickness at the end-diastole and end-systole. Self-gated cine imaging based on ultra-high-field MRI can be used to accurately and easily measure cardiac function and wall thickness in normal mouse hearts. As in the preclinical study, this versatile and simple method will be clinically useful for the high-field-MRI evaluation of cardiac function and wall thickness.     

High yield synthesis of Ni-BTC metal–organic framework with ultrasonic irradiation: Role of polar aprotic DMF solvent

Nickel based porous solid was synthesized with 20 kHz ultrasonic irradiation. The reaction of Ni(II) nitrate hexahydrate with 1,3,5-benzene tricarboxylic acid in N,N-Dimethylformamide (DMF) as the sole solvent under ultrasonic radiation produced porous Ni-BTC MOF. Choice of correct solvent for the ultrasonic treatment was proven important. The effect of varying ultrasonic powers (40%, 60% and 80% of 750 W) along with different temperature conditions (50 °C, 60 °C, 70 °C and 80 °C) influenced the respective yield. A very high yield of 88% Ni-BTC MOF was obtained from 80% ultrasonic power at 60 °C. BET surface areas of the MOF crystals measured by N₂ gas adsorption isotherms were in the range of 960–1000 m²/g.