Peak Fractions Research Articles

Effects of the inflow total temperature on the non-premixed rotating detonation engine performances

As a promising propulsion system, air-breathing rotating detonation engines (RDEs) are investigated with significant interest recently. However, simulations of air-breathing RDE with real flight condition are limited, and performance of RDEs with high inflow total temperature, as well as the influence of inflow total temperature on RDEs, needs further exploration. In this paper, simulations with four inflow total temperatures (300 K, 500 K, 700 K and 900 K) were conducted to analyze the propagation features of rotating detonation waves (RDWs) and operation modes in the RDE at low and high inflow total temperatures. Additionally, injection and mixing, as well as combustion characteristics and propulsion performance of the RDE were researched. It is found that with low inflow total temperature, single wave propagates in the combustor, which degenerates into shock wave at the outer wall due to insufficient mixing. When inflow total temperature is high, the RDE is in multi-wave operation mode and detonative combustion only occurs around the outer wall. With increase of inflow total temperature, mixability of reactants initially improves but then deteriorates slightly. Moreover, RDW propagation velocity and specific impulse of the RDE decrease. Though fuel utilization rate improves, detonation fraction drops dramatically and parasitic combustion fraction rises significantly, resulting from intensification of pre-combustion. Particularly, the detonation fraction is only 16.7 % and parasitic combustion fraction reaches up to 56.35 % at inflow total temperature of 900 K. Furthermore, regardless of the variation of inflow total temperature, detonative combustion is prominent in the premixed combustion mode, and the peak fraction of detonation appears at the off-stoichiometric ratio.

Numerical Study on Combustion Characteristics of a 600 MW Boiler Under Low-Load Conditions

Under the background of achieving carbon dioxide peaking and carbon neutrality, the rapid development of renewable energy power generation poses new challenges to the flexible adjustment capabilities of traditional power plants. To explore the furnace combustion stability and optimal operation modes during deep peak shaving, a simulation of the combustion process under low-load conditions for a 600 MW wall-fired boiler is performed utilizing computational fluid dynamics (CFD) analysis. The impact of burner combination modes on the combustion process within the furnace is explored at 25% and 35% boiler maximum continuous ratings (BMCRs). This study investigates two configurations of burner combinations. One mode operates burners in layers A, B, and C, which include the lower layers of burners on the front and rear walls of the boiler, as well as the middle-layer burners on the rear wall, referred to as OM1. The other mode operates burners in layers A and C, which include the lower layers of burners on the front and rear walls of the boiler, referred to as OM2. The results indicate that OM2 exhibits superior capabilities in orchestrating the distribution of the airflow velocity field and temperature field under the premise of ensuring no more than a 1% decrease in the pulverized coal burnout rate. When OM1 is employed, the airflow ejected from the middle-level burners hinders the upward movement of pulverized coal sprayed from the lower-level burners, causing a larger proportion of pulverized coal to enter the ash hopper for combustion. Consequently, the ash hopper attains a peak mole fraction of CO2 at 0.163. OM2 delays the blending of pulverized coal with air by enhancing the injection quantity of pulverized coal per burner. As a result, the generation of CO in the ash hopper reaches a notable mole fraction of up to 0.108. The decreased furnace temperature promotes the formation of fuel-based NOx during low-load operation. Taking the 25% BMCR as an example, the NOx emissions measured at the furnace outlet are 743 and 1083 ppm for OM1 and OM2, respectively. This study focuses on the impact of combustion combinations on the combustion stability when the boiler is operating at low loads. The findings could enrich previous research on combustion stability and contribute to the optimization of combustion schemes for power plant boilers operating at low loads.

Magnetic resonance spectroscopy as a diagnostic model for assessment of liver steatosis in metabolic dysfunction-associated steatotic liver disease in non-diabetic patients

BackgroundMetabolic dysfunction-associated steatotic liver (MASLD) disease is the commonest hepatic cause of liver fibrosis and cirrhosis after the introduction of the direct acting antivirals and eradication of hepatitis C. MASLD is usually associated with metabolic syndrome and elevated inflammatory markers. Magnetic resonance spectroscopy (MRS) offers a non-invasive diagnostic, alternative to liver biopsy. This is a case–control diagnostic-accuracy study conducted on 40 patients in the Hepato-gastroenterology Unit in the Internal Medicine Department, Ain Shams University Hospitals, to study the role of MRI spectroscopy as a new diagnostic model for assessment of liver steatosis in non-diabetic MASLD patients compared to the standard ultrasound and clinical criteria. MASLD was diagnosed by a combination of a validated ultrasound hepatic steatosis score grading system and hepatic steatosis index using clinical and laboratory parameters. MRS was performed in all patients and fat peak, water peak, and fat fraction % were measured, and diagnostic accuracy of different MRS is compared to the US scoring and different laboratory and clinical parameters. To our knowledge this is the first study conducted on MRS in our region and Egypt.ResultsThis study revealed no statistically significant difference between the two groups regarding HbA1C, creatinine, while there was highly statistically significant difference regarding fasting blood sugar, 2 h post-prandial glucose level, urine albumin, and low-density lipoprotein levels. Hepatic steatosis score grading by abdominal ultrasound on the 20 controls showed no fatty changes with grade 0 (50%), and on the 20 MASLD patients showed that 2 cases were grade 1 steatosis (5%), 9 cases were grade 2 steatosis (22.5%), and 9 cases were grade 3 steatosis (22.5%). The diagnostic accuracy of predicting hepatic steatosis using different MRS parameters: fat peak, water peak, and fat fraction had area under the curve of 99.9%, 88.6%, and 100%, respectively. The sensitivity and specificity of fat fraction in detecting hepatic steatosis were 100%. The sensitivity and specificity of the fat peak in detecting hepatic steatosis were 100% and 95%, respectively. Moreover, the sensitivity and specificity of the water peak in detecting the hepatic steatosis were 88.6% and 85%, respectively. There is a statistically significant correlation between the three MRS parameters and the abdominal ultrasound hepatic steatosis score grades.ConclusionMRS parameters: fat fraction, fat peak, and water peak, have high diagnostic accuracy for predicting the liver steatosis. Moreover, MRS has the added advantage of being a non-invasive and a tool with low radiation risk. MRS also shows the metabolic changes in the liver and could be an eligible outcome in therapeutic clinical trials.

Benchmark DEBORA: Assessment of MCFD compared to high-pressure boiling pipe flow measurements

A benchmark activity on two-fluid simulations of high-pressure boiling upward flows in a pipe is performed by 12 participants using different MCFD (Multiphase Computational Fluid Dynamics) codes and closure relationships. More than 30 conditions from DEBORA experiment conducted by CEA are considered. Each case is characterised by the flow rate, inlet temperature, wall heat flux and outlet pressure. High-pressure Freon (R12) at 14bar and 26bar is boiled in a 19.2mm pipe heated over 3.5m. Flow rates range from 2000kgm−2s−1 to 5000kgm−2s−1 and exit quality x ranges from single-phase conditions to x=0.1 which leads to a peak void fraction of α=70%. In these high pressure conditions, bubbles remain small and there is no departure from the bubbly flow regime (François et al., 2011; Hösler, 1968). However, different kind of bubbly flows are observed: wall-peak, intermediate peak or core-peak, depending on the case considered. Measurements along the pipe radius near the end of the heated section are compared to code predictions. They include void fraction, bubble mean diameter, vapour velocity and liquid temperature. The benchmark covered two phases. In the first phase of the benchmark activities, experimental data were given to the participants, allowing to compare the simulation results and to develop, to select or to adjust the models in the CMFD codes. The second phase included blind cases where the participants could not compare to the measurements. In between the two phases, possible additional model adjustments or calibrations were performed.Overall, the benchmark involved very different closures and a wide range of models’ complexity was covered. Yet, it is extremely difficult to have a robust closure for all conditions considered, even knowing experimental measurements. The wall-to-core peak transition is not captured consistently by the models. The degree of subcooling and the void fraction level are also difficult to assess. We were not capable of showing superiority of some physical closures, even for part of the model. The interaction between mechanisms and their hierarchy are extremely difficult to understand.Although departure from nucleate boiling (DNB) was not considered in this benchmarking exercise, it is expected that DNB predictions at high-pressure conditions depend strongly on the near-wall flow, temperature, and void fraction distributions. Therefore, the suitability of the closures also limits the accuracy of DNB predictions. The benchmark also demonstrated that in order to progress further in models development and validation, it is compulsory to have new measurements that include simultaneously as many variables as possible (including liquid temperature, velocity, cross-correlations and wall temperature); also, a better knowledge of the local bubble sizes distributions is the key to discriminate performances of interfacial area modelling (IATE, MUSIG or iMUSIG models, considering for instance the possibility of two classes of bubbles having totally different behaviour regarding the lift force).Following this benchmark impulse, we hope that future activities will be engaged on high-pressure boiling water experiments with a continuation of models’ comparisons and development.

Plateletcrit and absolute immature platelet count are not impacted by platelet transfusions: a single-centre prospective study

BACKGROUND This is the first study in which the impact of platelet transfusions on seven platelet indices was evaluated in platelet transfusion-dependent patients admitted in the ICU. STUDY DESIGN AND METHODS Among a cohort of 21 ICU patients prospectively studied over eleven months, a total of 19 ICU patients were enrolled. Seven platelet indices were measured before and then, within 18–24 h, after platelet transfusions using the Sysmex XN-10 analyser and statistically investigated as follows: i) apheresis vs. pooled platelet transfusions; ii) pre– vs. post–platelet transfusions; and iii) platelet count (PC) increment vs. PC decrement group. RESULTS A 79.2% of platelet transfusion episodes in ICU patients showed an increase in PC increment within 18–24 h, of which 73.7% had a peak percentage immature platelet fraction (%-IPF) above 10.0% during their stay. No difference was observed in the measurements of platelet indices between the apheresis and pooled platelet transfusion doses (all p > 0.05). Of the seven platelet indices investigated, plateletcrit (PCT) and absolute immature platelet count (A-IPF) were not influenced by platelet transfusions and thus proven to be stable (0.06 vs. 0.07%, p = 0.0901 and 4.6 vs. 4.9 × 109/L, p = 0.4559, respectively), despite their close proximity to platelet transfusion. But the overall effectiveness of these indices in detecting changes over time was not hindered. CONCLUSION A-IPF and PCT are stable after platelet transfusions, regardless of whether patient’s respond to or do not respond to platelet transfusion doses. PCT and A-IPF may thus prove useful in monitoring patient transfusion support and guiding management in thrombocytopenic patients.

Crystal structure, Raman spectroscopy and microwave dielectric properties of novel (1-x)MgGa2O4-xBaCu(B2O5) based LTCC materials

A novel series of (1-x)MgGa2O4-xBaCu(B2O5) (x = 0.1–0.5) microwave dielectric ceramics were prepared by solid phase method. By adding BaCu(B2O5) additives, the sintering temperature of MgGa2O4 ceramics was reduced from 1410 °C to 925 °C. Through an analysis of the trend in packing fraction and FWHM value of T2g Raman peak, the underlying influence mechanism of various intrinsic factors on the dielectric loss of ceramic were revealed. And the density, as the external factors, exhibits a positive correlation with the dielectric constant and Q × f value. In addition, the high bond strength of Ga-site reduces lattice distortion and consequently enhances the frequency temperature coefficient. The microwave dielectric properties of (1-x)MgGa2O4-xBaCu(B2O5) (x = 0.3) are found to be superior at a sintering temperature of 925 °C (εr = 9.42, Q × f = 35,480 GHz, τf = −22.7 ppm/°C, at 14 GHz). Moreover, the chemical compatibility of ceramics cofiring with Ag electrode makes them a highly promising substrate for microwave communications.

Optimization of single and double pass solar air heater-phase change material (SAH-PCM) system based on thickness to length ratio

This paper presents a two-dimensional transient model for a solar air heater with phase change material (SAH-PCM), focusing on the thickness-to-length ratio (t/L) of the PCM container. Verified through experiments, the model considers single (SP) and double pass (DP) flow configurations, assessing liquid fraction, dead length, outlet temperature, energy, exergy, and system efficiency during PCM charging and discharging. Increasing the t/L ratio improves peak liquid fraction, reduces dead length, and delays PCM discharge in both configurations, enhancing system energy and exergy efficiencies. In a SP flow system, optimizing t/L at 0.042 yields a peak liquid fraction of 0.928, a 92.28% dead length reduction, and a 2 h and 22 min delay for PCM discharge (base-case t/L ratio: 0.0182), achieving a highest discharging efficiency of 39.1%. For a DP flow system, the optimized t/L ratio of 0.058 results in a peak liquid fraction of 0.976 and a 1 hour and 34 min delay for PCM discharge, attaining the highest discharging efficiency of 63.34%. Moreover, an improvement in the energy payback time (EPBT) is observed for both SP and DP flow as the t/L is increased. For the DP flow, a minimum EPBT of 0.68 years (energy basis) and 6.55 years (exergy basis) is observed at a t/L ratio of 0.058. In terms of energy cost, SP flow reaches a minimum of Rs. 20.824 Rs/kWh at a t/L ratio of 0.042. For DP flow, the minimum energy cost is 13.033 Rs/kWh at a t/L ratio of 0.058, representing a noTable 37.42% improvement compared to SP flow. These findings underscore the critical role of optimizing system parameters, specifically the t/L ratio, for enhanced energy and exergy performance, and economic viability of SAH-PCM.

A generalized model for monitor units determination in ocular proton therapy using machine learning: A proof-of-concept study

Objective. Determining and verifying the number of monitor units is crucial to achieving the desired dose distribution in radiotherapy and maintaining treatment efficacy. However, current commercial treatment planning system(s) dedicated to ocular passive eyelines in proton therapy do not provide the number of monitor units for patient-specific plan delivery. Performing specific pre-treatment field measurements, which is time and resource consuming, is usually gold-standard practice. This proof-of-concept study reports on the development of a multi-institutional-based generalized model for monitor units determination in proton therapy for eye melanoma treatments. Approach. To cope with the small number of patients being treated in proton centers, three European institutes participated in this study. Measurements data were collected to address output factor differences across the institutes, especially as function of field size, spread-out Bragg peak modulation width, residual range, and air gap. A generic model for monitor units prediction using a large number of 3748 patients and broad diversity in tumor patterns, was evaluated using six popular machine learning algorithms: (i) decision tree; (ii) random forest, (iii) extra trees, (iv) K-nearest neighbors, (v) gradient boosting, and (vi) the support vector regression. Features used as inputs into each machine learning pipeline were: Spread-out Bragg peak width, range, air gap, fraction and calibration doses. Performance measure was scored using the mean absolute error, which was the difference between predicted and real monitor units, as collected from institutional gold-standard methods. Main results. Predictions across algorithms were accurate within 3% uncertainty for up to 85.2% of the plans and within 10% uncertainty for up to 98.6% of the plans with the extra trees algorithm. Significance. A proof-of-concept of using machine learning-based generic monitor units determination in ocular proton therapy has been demonstrated. This could trigger the development of an independent monitor units calculation tool for clinical use.

Quantification of asciminib by LC-MS/MS method in human plasma: Validation and stability studies

An accurate, sensitive, and linear liquid chromatographic tandem mass spectrometric method was developed for the quantification of asciminib in human plasma. Voriconazole, internal standard (IS), and asciminib were isolated from the plasma samples by C18-cartridges. Chromatographic isolation was processed with Atlantis/dC18 (2.1 × 100 mm, 3 μm) stationary phase and a mobile solvent system of formic acid (0.1%) and methyl alcohol (20:80, v:v), conveyed at a 0.7 ml/minute flowing rate. Analytes were quantified by ionization in a positive approach with electrospray ionization at the mass transitions of (m/z): asciminib, 450.11/239.09, and voriconazole (IS), 350.3/281.1. No interference by constituents of plasma blank or other components was detected. The association between asciminib concentration levels and their respective peak response fractions to voriconazole was rectilinear between 39.0 and 1,586.0 ng/ml. Intraday and interday precisions were ≤4.79% for asciminib. The interday bias was between −4.28% and 5.76%, and the intraday bias was −3.75% and 4.53%. The mean measured extraction recovery of asciminib was 99.06%. The recovery of IS was 98.34%. Asciminib was subjected to long-term, bench-top, freeze-thaw, short-term stability, dry extract, auto-sampling, and stock solution stability at Low quality control and High quality control levels, and it was stable at all these conditions. The established technique can be utilized for the regular quantification of asciminib in plasma samples in industries, forensic laboratories, and clinical research organizations.

Crystal structure and microwave dielectric properties of BaZnP2O7-based ceramics with Sr2+ substitution

In this study, Ba1-xSrxZnP2O7 (0 ≤ x ≤ 0.1) ceramics were synthesized at 875–950 °C. The X-ray diffraction and SEM test revealed that Ba1-xSrxZnP2O7 (0 ≤ x ≤ 0.1) ceramics formed a single phase with a P-1 triclinic structure. Moreover, a moderate substitution of Sr2+ is conducive to grain growth and pore reduction. The εr value was primarily affected by the average bond ionicity (Afi) and porosity, while the unit molecule polarizability contribution was insignificant. The Q × f value was closely related to the packing fraction, Utotal, and FWHM value of the strongest peak with a wavelength of approximately 1050 cm−1 in Raman spectra. Additionally, the P–O bond significantly influenced the bond ionicity and lattice energy. The Ba0.92Sr0.08ZnP2O7 ceramic sintered at 925 °C for 4 h exhibits satisfactory microwave performance: εr = 8.26 ± 0.06, Q × f = 61,677 ± 1781 GHz, τf = −18.34 ± 0.21 ppm/°C.

Simulation of High-contrast Polarimetric Observations of Debris Disks with the Roman Coronagraph Instrument

The Nancy Grace Roman Space Telescope Coronagraph Instrument will enable the polarimetric imaging of debris disks and inner dust belts in the optical and near-infrared wavelengths, in addition to the high-contrast polarimetric imaging and spectroscopy of exoplanets. The Coronagraph uses two Wollaston prisms to produce four orthogonally polarized images and is expected to measure the polarization fraction with measurement errors <3% per spatial resolution element. To simulate the polarization observations through the Hybrid Lyot Coronagraph (HLC) and Shaped Pupil Coronagraph (SPC), we model disk scattering, the coronagraphic point-response function, detector noise, speckles, jitter, and instrumental polarization and calculate the Stokes parameters. To illustrate the potential for discovery and a better understanding of known systems with both the HLC and SPC modes, we model the debris disks around Epsilon Eridani and HR 4796A, respectively. For Epsilon Eridani, using astrosilicates with 0.37 ± 0.01 as the peak input polarization fraction in one resolution element, we recover the peak disk polarization fraction of 0.33 ± 0.01. Similarly, for HR 4796A, for a peak input polarization fraction of 0.92 ± 0.01, we obtain the peak output polarization fraction as 0.80 ± 0.03. The Coronagraph design meets the required precision, and forward modeling is needed to accurately estimate the polarization fraction.

The effect of probiotic strains on the proteolytic activity and peptide profiles of lupin oat-based yoghurt

Plant-based yoghurt is on the rise, addressing both sustainability and innovation in food production. The macro-molecular changes driven by bacterial strains during fermentation of plant-based yoghurt leading to diverse nutritional functionality, however, is overlooked. Here, the lupin-oat milk yoghurt was developed using three distinctive commercial starter cultures composed of Lactobacillus delbrueckii sub bulgaricus, Streptococcus thermophilus and Lactobacillus rhamnosus for yoghurt 1 (Y1), Lactobacillus delbrueckii sub bulgaricus, Streptococcus thermophilus and Lactobacillus paracasei for yoghurt 2 (Y2), Lactobacillus plantarum and Bifidobacterium sps for yoghurt 3 (Y3). The post-acidification, proteolytic activity, amino acid composition, cell viability, peptide profile and angiotensin-converting enzyme (ACE) inhibitory activity were investigated during seven days of refrigeration at 4 °C. Gel electrophoresis and size exclusion chromatography (SEC) of yoghurts, showed substantial degradation of proteins into low molecular weight protein fractions (45, 55 and 75 kDa) which are complemented by an increase in small polypeptides with a molecular weight of <20 kDa. The bacteria did not fully utilize the released peptides, leading to significant accumulations in the medium. This observation indicates the potential presence of bioactive compounds with beneficial effects. The SEC peak fraction containing a smaller peptide size ranging from 0.059 to 0.87 kDa showed better ACE inhibitory activity. A comprehensive analysis of peptide profiling of the yoghurts was done using Nano UPLC-MS/MS which showed co-cultures promoted the formation of peptides. After undergoing bacterial fermentation, the number and types of peptides followed the Y3>Y1>Y2 sequence. This study emphasizes the potential of lupin-oat yoghurts peptides as a functional component.

Dynamic recrystallization behavior of selective laser melted 316L stainless steel

The present work deals with the hot deformation behavior of selective laser melted 316L stainless steel with an emphasize on the involved recrystallization mechanisms. Toward this end, a series of hot compression test have been conducted in the temperature range of 700–1000 °C under the various strain rates of 0.001, 0.01 and 0.1s−1. The flow pattern analysis through Jonas-Poliak method verifies the occurrence of dynamic recrystallization in whole investigated temperature range. The intensified substructure development and continuous recrystallization is identified as the main softening mechanism in the course of thermomechanical processing. This causes appearance of a broad peak and low softening fraction in corresponding flow curves. The cellular substructure in the as-printed state facilitates low-angle into high-angle boundaries conversion, which provide a proper condition for the occurrence of continuous mechanisms and increases the rate of recrystallization. However, detailed investigation of the sub-boundary maps indicates the contribution of discontinuous and geometric dynamic recrystallization mechanisms. Dynamic recrystallization causes substantial refinement; and the percentage of the grain holding size lower than 10 μm increases from 2 % in printed microstructure to 16.8 % and 24 % in the microstructure deformed at 700 and 1000 °C.

Ion exchange chromatography as a simple and scalable method to isolate biologically active small extracellular vesicles from conditioned media.

In the last few years, extracellular vesicles (EVs) have become of great interest due to their potential as biomarkers, drug delivery systems, and, in particular, therapeutic agents. However, there is no consensus on which is the best way to isolate these EVs. The choice of the isolation method depends on the starting material (i.e., conditioned culture media, urine, serum, etc.) and their downstream applications. Even though there are numerous methods to isolate EVs, few are compatible with clinical applications as they are not scalable. In the present work, we set up a protocol to isolate EVs from conditioned media by ion exchange chromatography, a simple, fast, and scalable method, suitable for clinical production. We performed the isolation using an anion exchange resin (Q sepharose) and eluted the EVs using 500 mM NaCl. We characterized the elution profile by measuring protein and lipid concentration, and CD63 by ELISA. Moreover, we immunophenotyped all the eluted fractions, assessed the presence of TSG101, calnexin, and cytochrome C by western blot, analyzed nanoparticle size and distribution by tRPS, and morphology by TEM. Finally, we evaluated the immunomodulatory activity in vitro. We found that most EVs are eluted and concentrated in a single peak fraction, with a mean particle size of <150nm and expression of CD9, CD63, CD81, and TSG101 markers. Moreover, sEVs in fraction 4 exerted an anti-inflammatory activity on LPS-stimulated macrophages. In summary, we set up a chromatographic, scalable, and clinically compatible method to isolate and concentrate small EVs from conditioned media, which preserves the EVs biological activity.

Small conformational changes in IgG1 detected as acidic charge variants by cation exchange chromatography

Fully characterizing the post-translational modifications present in charge variants of therapeutic monoclonal antibodies (mAbs), particularly acidic variants, is challenging and remains an open area of investigation. In this study, to test the possibility that chromatographically separated acidic fractions of therapeutic mAbs contain conformational variants, we undertook a mAb refolding approach using as a case study an IgG1 that contains many unidentified acidic peaks with few post-translational modifications, and examined whether different acidic peak fractions could be generated corresponding to these variants. The IgG1 drug substance was denatured by guanidine hydrochloride, without a reducing agent present, and gradually refolded by stepwise dialysis against arginine hydrochloride used as an aggregation suppressor. Each acidic chromatographic peak originally contained in the IgG1 drug substance was markedly increased by this stepwise refolding process, indicating that these acidic variants are conformational variants. However, no conformational changes were detected by small-angle X-ray scattering experiments for the whole IgG1, indicating that the conformational changes are minor. Chromatographic, thermal and fluorescence analyses suggested that the conformational changes are a localized denaturation effect centred around the aromatic amino acid regions. This study provides new insights into the characterization of acidic variants that are currently not fully understood.

MRI Spectroscopy as a Diagnostic Model for Assessment of Liver Steatosis in NAFLD Non-Diabetic Patients

Abstract Background Non-alcoholic fatty liver disease, the hepatic pandemic of the XXI century, being the number one cause of chronic hepatic disease in the occidental world. Aim of the Work To evaluate the diagnostic performance of MRI spectroscopy for assessing hepatic steatosis in nonalcoholic fatty liver disease (NAFLD) in non diabetic patients. Patients and Methods A case control study was conducted on 40 patients inhepatology and gastroenterology department &amp; Radiology department ain shams university hospital from Jan 2020 to November 2020 to study role of MRI spectroscopy as adiagnostic model for assessment of liver steatosis in NAFLD non diabetic patients. Results There was statically significant Positive correlation Between hepatic steatosis score, fat peak and fat fraction %, and there was statically significant Negative correlation Between Hepatic steatosis score and water peak. Conclusion MRI Spectroscopy can be reliably used as an accurate and specific noninvasive method for the diagnosis of Nonalcoholic fatty Liver Disease.

Structural and optical characterization of RF sputtered CdMgZnO thin film with different Cd concentrations

CdMgZnO (CMZO) thin films oriented along the c-axis with various Cd concentrations were deposited on Si substrate using radio frequency (RF) magnetron sputtering. The thin-film crystal structure, narrowing of the optical band gap, and photoluminescence depended on the Cd concentration. Cd concentration from 0% -to-2.5% increased the grain size of the thin films from 24.03 nm to 45.34 nm and decreased the texture fraction of (002) peak (TF(002)) by 9.6%. With the grain size increase in the thin films, the optical band gap narrowed to lower energies and decreased from 3.55 to 3.45 eV due to conduction band adjustment and the valence band repulsion effect from increasing Cd. The photoluminescence properties of all CMZO thin films were strong in the UV region. The thin film grown at 1.5% of Cd showed a broad yellow emission at 581 nm that is optically active due to a defect of oxygen interstitial (Oi). Defect emissions of blue, orange, and red intensities were found to decrease rapidly with the increasing Cd concentration depleting the recombination of photo-generated holes or charge carriers significantly.

Dielectric relaxation and ionic conduction in solid polymer electrolyte based on a random copolymer of ethylene carbonate and ethylene oxide

Broadband dielectric spectroscopy (BDS) is a powerful technique for studying the dielectric and ion-conductive behavior of solid polymer electrolytes (SPE). In this study a random copolymer of ethylene carbonate (EC) and ethylene oxide (EO), P(EC/EO), was used as a polymer host for SPE, and the correlation between dielectric relaxation and ionic conduction in P(EC/EO)-LiFSI electrolytes was studied. BDS measurements revealed that the DC conductivity for P(EC/EO) electrolytes is higher than for the PEC system at all salt concentrations. This is due to the much higher a-relaxation frequency, indicating that the randomly introduced EO units can provide fast segmental motion with no formation of any stable coordination structures with Li ions. FT-IR analysis indicated that the peak fraction of C = O interacting with Li ions was small, less than 10% in the 10 mol% electrolyte, but in concentrations above 40 mol% the proportion was nearly saturated at around 60–70%. A small CO-C peak interacting with Li ions appears at 1080 cm−1, but no change in peak intensity is observed, implying no formation of stable coordination structures that reduce the glass transition temperature.

Spontaneous coronary artery dissection: the role of Coronary CT angiography in the follow-up management

Abstract Funding Acknowledgements Type of funding sources: None. Background Spontaneous coronary artery dissection (SCAD) is one of the causes of acute coronary syndrome (ACS), myocardial infarction (MI) and sudden death (SD). Diagnosis is done with coronary angiography (CA); nevertheless, coronary computed tomography angiography (CCTA) is a new useful tool in the acute diagnosis and at follow-up. Treatment could involve a conservative approach or an invasive approach with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG). Purpose 1) analyze the clinical and CCTA features at baseline of patients with a SCAD diagnosis; 2) evaluate the clinical and anatomic outcome at follow-up of patients with a SCAD diagnosis treated with a conservative or invasive approach; 3) evaluate in the conservative approach treated patients the clinical and anatomic outcome of those dismissed with single or double antiplatelet therapy. Methods A retrospective analysis of 57 patients affected by SCAD followed up with Coronary CT angiography (CCTA) between 2010 and 2022. Clinical and anatomic data were collected at baseline and at the follow-up (FU). The clinical endpoints evaluated were: all cause mortality, hospitalization for cardiovascular cause, SCAD or PCI ex-novo and MI; the anatomic endpoints were: patency of coronary artery and/or stents and length dissection changing from baseline. Results 57 patients were divided in 2 groups: 46 (80,7%) patients underwent a conservative treatment and 11 (19,3%) patients a PCI treatment. Patients treated with PCI has a significative incidence of smokers (45,5% vs 15,2%; p = 0,042), peripherical arteriopathy (18,2% vs 0%; p = 0,034), higher troponin peak (40425,8 vs 13436; p = 0,011) and lower ejection fraction (51,4±11,0 vs 57,1±7,6; p = 0,050). Moreover the PCI population has a significant involvement of more than one coronary artery (72,7% vs 6,5%; p&amp;lt;0,001), of the proximal tracts of the coronary arteries (22,8% vs 13 %; p = 0,001) and of the truncus communis (45,4% vs 0%; p&amp;lt;0,001). At the follow up, there were no statistical differences for the clinical and anatomic endpoints between the conservative and invasive treated patients (p&amp;gt;0,05). Among patients treated with conservative therapy, there were a significant recurrence of SCAD in those treated with DAPT than in those treated with SAPT (33,3% vs 5,9%; p = 0,033). Conclusions patients with SCAD managed with PCI have more cardiovascular risk factors, a major myocardial infarction extension and a more complex coronary arteries involvement; conservative management is comparable to the PCI treatment for the clinical and anatomic endpoints evaluated; DAPT at discharge was associated with a higher rate of SCAD recurrence at follow-up.

Fiber reinforced hydrated networks recapitulate the poroelastic mechanics of articular cartilage

The role of poroelasticity on the functional performance of articular cartilage has been established in the scientific literature since the 1960s. Despite the extensive knowledge on this topic there remain few attempts to design for poroelasticity and to our knowledge no demonstration of an engineered poroelastic material that approaches the physiological performance. In this paper, we report on the development of an engineered material that begins to approach physiological poroelasticity. We quantify poroelasticity using the fluid load fraction, apply mixture theory to model the material system, and determine cytocompatibility using primary human mesenchymal stem cells. The design approach is based on a fiber reinforced hydrated network and uses routine fabrication methods (electrohydrodynamic deposition) and materials (poly[ɛ-caprolactone] and gelatin) to develop the engineered poroelastic material. This composite material achieved a mean peak fluid load fraction of 68%, displayed consistency with mixture theory, and demonstrated cytocompatibility. This work creates a foundation for designing poroelastic cartilage implants and developing scaffold systems to study chondrocyte mechanobiology and tissue engineering. Statement of significancePoroelasticity drives the functional mechanics of articular cartilage (load bearing and lubrication). In this work we develop the design rationale and approach to produce a poroelastic material, known as a fiber reinforced hydrated network (FiHy™), that begins to approach the native performance of articular cartilage. This is the first engineered material system capable of exceeding isotropic linear poroelastic theory. The framework developed here enables fundamental studies of poroelasticity and the development of translational materials for cartilage repair.