Reproducible Values Research Articles

Clinical application of fly-thru in diagnosis of biliary obstructive diseases: feasibility, reproducibility, and diagnostic value.

To evaluate the feasibility, reproducibility, and diagnostic value in biliary obstructive diseases using Fly-Thru (FT) technique. In this single-center prospective study, patients with biliary obstruction who underwent both abdominal ultrasound and FT examinations were recruited between January 2013 and January 2023. 3D FT images (3D-FT) were reconstructed with FT volumetric data. Image quality was subjectively assessed by two radiologists independently. 3D-FT was used to determine the degree of biliary obstruction and compared with ultrasound-guided percutaneous transhepatic cholangiography (PTC). Diagnostic confidence level, diagnostic accuracy and diagnostic duration of the two radiologists using 2D-ultrasound (2D-US) alone and 2D-US combined with 3D-FT were recorded respectively and compared. 100 consecutive patients were enrolled (mean age: 59.6 ± 13.2 years; 52 men). All 3D-FT images were successfully reconstructed and most (75% and 66%) 3D-FT images were considered clear and highly useful for diagnosis with a good agreement (Kappa = 0.653). Benign lesions and malignancies presented differently in both 2D-US and 3D-FT imaging. 3D-FT was not inferior to PTC in determining the degree of biliary obstruction (p = 0.101), with the sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, positive predictive value, and positive predictive value as 90.5%, 26.7%, 1.23, 0.36, 77.6%, 50.0% respectively. Combined with 2D-US, 3D-FT significantly increased the diagnostic confidence level and diagnostic accuracy of biliary obstructive diseases (all p < 0.01), especially for radiologists with less experience. Application of 3D-FT in diagnosis of biliary obstructive diseases was considered feasible and reproducible, with satisfactory diagnostic value and clinical importance.

Accuracy and Reproducibility of Lipari-Szabo Order Parameters From Molecular Dynamics.

The Lipari-Szabo generalized order parameter probes the picosecond to nanosecond time scale motions of a protein and is useful for rationalizing a multitude of biological processes such as protein recognition and ligand binding. Although these fast motions are an important and intrinsic property of proteins, it remains unclear what simulation conditions are most suitable to reproduce methyl symmetry axis side chain order parameter data (Saxis2) from molecular dynamics simulations. In this study, we show that, while Saxis2 tends to converge within tens of nanoseconds, it is essential to run 10 to 20 replicas starting from configurations close to the experimental structure to obtain the best agreement with experimental Saxis2 values. Additionally, in a comparison of force fields, AMBER ff14SB outperforms CHARMM36m in accurately capturing these fast time scale motions, and we suggest that the origin of this performance gap is likely attributed to differences in side chain torsional parametrization and not due to differences in the global protein conformations sampled by the force fields. This study provides insight into obtaining accurate and reproducible Saxis2 values from molecular simulations and underscores the necessity of using replica simulations to compute equilibrium properties.

Quantitative brain [18F]FDG PET beyond normal blood glucose levels

Introduction SUV measurements from static brain [18F]FDG PET acquisitions are a commonly used tool in preclinical research, providing a simple alternative for kinetic modelling, which requires complex and time-consuming dynamic acquisitions. However, SUV can be severely affected by the animal handling and preconditioning protocols, primarily by those that may induce changes in blood glucose levels (BGL). Here, we aimed at developing and investigating the feasibility of SUV-based approaches for a wide range of BGL far beyond normal values, and consequently, to develop and validate a new model to generate standardized and reproducible SUV measurements for any BGL.Material and methods We performed dynamic and static brain [18F]FDG PET acquisitions in 52 male Sprague-Dawley rats sorted into control (n = 10), non-fasting (n = 14), insulin-induced hypoglycemia (n = 12) and glucagon-induced hyperglycemia (n = 16) groups. Brain [18F]FDG PET images were cropped, aligned and co-registered to a standard template to calculate whole-brain and regional SUV. Cerebral Metabolic Rate of Glucose (CMRglc) was also estimated from 2-Tissue Compartment Model (2TCM) and Patlak plot for validation purposes.Results Our results showed that BGL=100±6 mg/dL can be considered a reproducible reference value for normoglycemia. Furthermore, we successfully established a 2nd-degree polynomial model (C1=0.66E-4, C2=-0.0408 and C3=7.298) relying exclusively on BGL measures at pre-[18F]FDG injection time, that characterizes more precisely the relationship between SUV and BGL for a wide range of BGL values (from 10 to 338 mg/dL). We confirmed the ability of this model to generate corrected SUV estimations that are highly correlated to CMRglc estimations (R2= 0.54 2TCM CMRgluc and R2= 0.49 Patlak CMRgluc). Besides, slight regional differences in SUV were found in animals from extreme BGL groups, showing that [18F]FDG uptake is mostly directed toward central regions of the brain when BGLs are significantly decreased.Conclusion Our study successfully established a non-linear model that relies exclusively on pre-scan BGL measurements to characterize the relationship between [18F]FDG SUV and BGL. The extensive validation confirmed its ability to generate SUV-based surrogates of CMRglu along a wide range of BGL and it holds the potential to be adopted as a standard protocol by the preclinical neuroimaging community using brain [18F]FDG PET imaging.

Implementation of a New Classification and Stratification System for Solitary Bone Tumor: Osseous Tumor Radiological and Interpretation and Management System (OT-RIMS)

Abstract Objectives To propose a histological-grades-based Osseous Tumor Radiological Interpretation and Management System (OT-RIMS) that would simplify the radiological evaluation of bone tumors, categorize key radiological features into severity levels, and inform corresponding patient management actions. Methods This retrospective study between January 2015 and August 2022 evaluated patients with solitary bone tumors confirmed by pathology and imaging follow-up received two or three imaging modalities of radiographs, CT, or MRI. Three radiologists independently assessed radiological features, categorized bone lesions based on OT-RIMS criteria, and reached a consensus. Kappa statistics and observed agreement were calculated. Results A total of 341 patients (mean age, 26.0 years; 159 women) were included, with 102 malignant, 177 benign, and 62 intermediate or low-grade malignant bone lesions. Sensitivity and specificity of readers 1, 2, and 3, respectively, in the identification of malignant tumors into OT-RIMS 4 were 93.1% (95 of 102) and 93.3% (223 of 239), 96.1% (98 of 102) and 91.6% (219 of 239), 92.2% (94 of 102) and 89.5% (214 of 239). Inter-reader agreement of OT-RIMS category for three readers was considered excellent (Kendall’s W = 0.924, p &amp;lt; 0.001) with a kappa value of reproducibility in categories 1&amp;2, 3, and 4 of 0.764, 0.528, and 0.930, respectively. Conclusion The OT-RIMS category demonstrated excellent reproducibility despite the reader’s expertise level in categorizing the risk stratification of bone tumors and informing patient management, with histological grades used as the reference standard. Advances in knowledge The OT-RIMS category reliably stratifies bone tumors into four categories corresponding to histological grades and standardized patient management.

Global correlation of the Guadalupian–Lopingian transition and associated events using a quantitative conodont-based biostratigraphic scheme

The Guadalupian–Lopingian boundary (GLB) interval contains global-scale changes in biota and environment. The establishment of a uniform time scale and a robust system of global correlation are critical in order to unravel the tempo of these events. Conodonts are key biostratigraphic tools; however, major discrepancies exist in conodont taxonomy and correlation in this interval. In this paper, we compile conodont data from 17 well-studied sections in South China, Japan, Oman and North America, comprising 206 occurrences and 100 species, based on previous publications and our own revisions, to test the reproducibility and correlation value of formerly established interval zones. The Unitary Association method (UAM), a quantitative stratigraphic method for the construction of biozones, is applied to construct a robust conodont biozonation for the GLB. Eleven unitary associations (UAs) and eight unitary association zones (UAZs) are recognized to establish biozones and the GLB was constrained within the UAZ5. According to the reproducibility of these UAZs, the correlation of the Lopingian is generally better than the Guadalupian. Apparent contradictions revealed by the UAZs suggest that biostratigraphic and/or taxonomic issues are present within the Clarkina liangshanensis, C. leveni, C. transcaucasica interval zones. The interval between UAZ4 and UAZ5 records the conodont turnover event from Jinogondolella to Clarkina in the paleoequatorial region. Our results suggest that the UAZs are more reliable for correlation. By contrast, some taxonomic and phylogenetic issues are present in the interval zones based on the conodont succession around the GLB. Although at a coarser stratigraphic resolution, removing all the contradictions enables UAZs to better correlate global sections compared with interval zones. The newly established UAZs indicate that the previously reported isotope excursions around the GLB in different regions may be temporally inconsistent.

Three-dimensional anatomical analysis of the optic nerve canal with virtual model based on CBCT

The optic nerve canal (ONC) is a fine skeletal structure that contains the optic nerve. However, it has not been thoroughly examined. This necessitates establishing a baseline knowledge of the geometrical and volumetric parameters of the ONC. The data of twenty patients who received a cone beam computed tomography examination were prepared using a voxel-based segmentation. The measurement was performed separately by two examiners on virtual skull models in stereolithography format in Geomagic Wrap®. The results showed that the volume of the ONC varied between 92.48 mm3 and 162.7 mm3 (M = 123.46 mm3, SD = 26.61 mm3). Sex-specific statistically significant differences in volume were detected only for the right side. The angle of the ONC to the skull base was independent of the diameter of the canal. Both the intrarater and interrater comparisons of the measurements showed high values of reproducibility of the results. This study showed that a virtual anatomical model provides a feasible and reliable method to investigate the ONC. The examination technique could have a wider range of application in anthropology and application in clinical medicine. Advances in the automation of radiological diagnostics and the digital analysis of X-ray images could help to reduce examination times.

Hybrid organic monolithic column containing MIL-68(Al) for the separation of small molecules by capillary HPLC

A hybrid organic monolithic column made of poly(lauryl methacrylate-co-1,6-hexanediol dimethacrylate) and the metal-organic framework MIL-68(Al) was prepared for the first time. The column was used in capillary liquid chromatography, both in isocratic and gradient elution modes. Separation performance towards small molecules of different chemical nature (polycyclic aromatic hydrocarbons, alkylbenzenes, phenols, etc.) was studied. Monte Carlo simulations were made to both select the proper precursors to obtain empty metal-organic framework micropores in the monolithic polymer and also, to analyze the potential free access of the studied analytes into the micropores (necessary to improve mass transfer and column efficiency). The hereby synthesized metal-organic framework microcrystals allowed obtaining homogeneous hybrid monolithic columns. Adding of MIL-68(Al) (1030 m2 g-1 BET specific surface area) increased the surface area from 3.9 m2 g-1 for the parent monolith to 18.2 m2 g-1 for the hybrid column containing 8 mg mL-1 of the microcrystals. Chromatographic performance of this new column was evaluated by studying retention factors, resolution, and plate counts at room temperature. Different compounds, not completely resolved in the parent monolith, were partially or completely separated after metal-organic framework addition. Using the monolithic column with only 2 mg mL-1 of MIL-68(Al), five alkylbenzenes were completely separated with very symmetrical peak shapes, resolution factors up to 3.60 and plate counts of 4300 plates m-1 for n-hexylbenzene. This value is higher than those obtained by other authors who used organic monolithic columns with embedded metal-organic frameworks to perform separations at room temperature. Additionally, nine polycyclic aromatic hydrocarbons were partially or completely resolved in gradient elution mode. The hybrid monolithic columns exhibited very good intra-day (%RSD=1.9), inter-day (%RSD=2.6), and column-to-column (%RSD=4.3) reproducibility values. Easy and fast column preparation, and versatility to efficiently separate several compounds of different chemical nature in isocratic and gradient mode, makes this new hybrid column a very good option for the analysis of small molecules in capillary (or nano) HPLC.

Comparison of a semi-automatic strain analysis of left heart with manual myocardial tracing in speckle-tracking echocardiography

Purpose. To compare a semi-automatic strain analysis of the left ventricle and left atrium with a manual method in speckle-tracking echocardiography.Materials and methods. A strain of left ventricle and left atrium was assessed in 110 patients by two methods: manual (Q-Analysis) and semi-automatic (AutoStrain). The following parameters were evaluated: LV global longitudinal strain (LV GLS), LA longitudinal strain during the reservoir phase (LASr), LA longitudinal strain during the conduit phase (LAScd), and LA longitudinal strain during the contraction phase (LASct).Results. The ROI correction was carried out significantly more often with the semi-automatic method of measuring LV GLS than with manual (40.1% vs. 16.4%, p &lt; 0.05). There were significant differences in LV GLS average values, LASr values, and LAScd values obtained by the semi-automatic and manual methods. LV GLS average values obtained by the semi-automatic method were lower (18.8 ± 2.8% vs. 20.0 ± 3.1%, p &lt; 0.001), and the values of LASr and LAScd obtained by the semi-automatic method were higher (LASr 31.6 ± 9.8% vs. 30.3 ± 10.8%, p = 0.038; LAScd 17.1 ± 7.1% vs. 15.4 ± 6.8%, p &lt; 0.001) than in manual. Semi-automatic method takes more time for LV strain analysis and less time for LA strain analysis than manual method.Conclusion. The semi-automatic method of LV and LA strain evaluation showed higher reproducibility compared with the manual method. With the semi-automatic method, the values of the LV GLS were lower, and the correction of ROI was required more often and took more time than with manual. The semi-automatic method of LA strain evaluation was characterized by higher values in the reservoir and conduit phases and required less time compared to the manual method. The LA longitudinal strain in the reservoir phase showed the highest values of reproducibility compared to other LA strain paremeters.

Radiological Landmarks for Joint Line Level in Challenging Total Ankle Arthroplasty.

Background: Although Total Ankle Arthroplasty (TAA) is primarily performed for post-traumatic ankle arthritis with joint disruption, anatomical landmarks for Joint Line (JL) level are typically preserved. However, severe Post-Traumatic Bone Loss (PTBL) or TAA revision may render some landmarks unidentifiable, challenging JL restoration. Methods: Patients undergoing customized TAA for severe PTBL or revision were enrolled. Custom-made implants, based on 3D CT scans, were designed to address bone defects and provide adequate bone support. Evaluated parameters, measured on bilateral ankle weight-bearing radiographs taken preoperatively and 6-8 months postoperatively, included JL Height Ratio (JLHR) and the distances from JL to the Lateral Malleolus apex (LM-JL), the posterior colliculus of the Medial Malleolus (MM-JL), and the Gissane Calcaneal Sulcus (CS-JL). Reproducibility and variability were assessed, and comparisons were made between radiological parameters measured at TAA and those at the contralateral ankle. Results: Thirteen patients were included. Intra- and interobserver reliability demonstrated excellent values. The least variability was observed in the LM-JL distance. Statistically significant correlations were found between CS-JL and MM-JL distances in the operated limb and between the CS-JL of the operated limb and the contralateral ankle. While TAA parameters did not show statistically significant differences compared with the contralateral ankle, a trend toward proximalization of the JL was noted. Conclusions: This study demonstrated good reproducibility of the analyzed parameters for evaluating JL in TAA among patients with severe PTBL or undergoing revision surgery. However, these parameters cannot be deemed fully reliable. Given their potential weaknesses, it is crucial to identify more reproducible values, preferably ratios.

Measurement of inward leakage of full-face masks in EN and ISO standards: comparison of gas and aerosol test agents.

In Europe, respiratory protective devices must be certified before they can be marketed. Among the parameters of interest, inward leakage (IL) characterizes the tightness between the face seal and the face, to verify that the device is well-designed. European standard EN 13274-1 (2001) and International Organization for Standardization (ISO) standard ISO 16900-1 (2019) specify that IL should be measured using sodium chloride (NaCl) aerosol or sulfur hexafluoride (SF6) gas. For reusable masks made of nonporous materials, both test agents are considered equally acceptable. However, the few studies that have compared IL values measured with various aerosols and gases have come to divergent conclusions. This work then aimed to measure IL with the test agents recommended by the standards to determine whether they are really equivalent. Since krypton (Kr) is an interesting candidate for replacing SF6 in standard tests, IL was assessed with SF6 and Kr simultaneously, and with NaCl aerosol using various calculation methods. Tests were carried out on 5 models of full-face masks donned on a headform connected to a breathing machine simulating 3 sinusoidal breathing rates of various intensities. The respirator fit on the headform was evaluated using a controlled negative pressure method to determine a manikin fit factor. Four scenarios were then tested to represent very poor, bad, good, and excellent fit. Gas concentration was measured using a mass spectrometer, and IL was calculated for SF6 and Kr. A combination of 3 devices allowed the determination of the number-based concentration of particles with diameters between 20 nm and 2 µm, and IL was calculated for each of the 33 channels, as well as using a cumulative number concentration. In addition, to comply with standards, a conversion was carried out to calculate IL using a cumulative mass concentration. The results of this work evidenced that the IL values measured with NaCl were systematically lower than those determined with gases. IL was also shown to vary with particle size, with a maximum value exceeding that calculated with cumulative concentrations (in number or mass). As part of the revision of the standards, protocols for measuring inward leakage should be redefined. On the one hand, acceptability thresholds should be re-evaluated according to the nature of the test agent (gas or aerosol), as it is clear that the 2 options do not give the same results for a given configuration. On the other hand, the aerosol leakage measurement protocol needs to be reworked to enable the measurement of a well-defined, robust, and reproducible inward leakage value.

On-Chip Capture, Raman-Silent Polymer Labeling, and Digital Mapping Analysis of Escherichia coli O157:H7 in Beverages All-in-One.

Escherichia coli O157:H7 is one of the most susceptible foodborne pathogens, easily causing food poisoning and other health risks. It is of great significance to establish a quantitative method with higher sensitivity and less time consumption for foodborne pathogens analysis. The Raman-silent signal has a good performance for avoiding interference from the food matrix so as to achieve accurate signal differentiation. In this work, we presented a preparation-mapping all-in-one method for digital mapping analysis. We prepared a functionalized Raman-silent polymer label of Escherichia coli O157:H7, which was captured on a porous 4-mercaptophenylboric acid@Ag foam chip. To improve accuracy and widen the detection range, a digital mapping quantitative strategy was employed in data extraction and processing. By transfer mapping information into digitized statistical results, the limitation of obtaining reproducible intensity values just by randomly selected spots on the substrate can be addressed. With a wide linear range of 1.0 × 101-1.0 × 105 CFU mL-1 and a limit of detection of 4.4 CFU mL-1, this all-in-one method had good sensitivity performance. Also, this method achieved good precision and selectivity in a series of experiments and was successfully applied to the analysis of beverage samples.

Quick and high-throughput quantification of β-agonist residues in bovine liver, meat, milk, kidney, poultry, and egg using dispersive solid phase extraction

A reliable liquid chromatography coupled to quadrupole-Orbitrap high-resolution mass spectrometry (LC-Q-Orbitrap HRMS) method was developed for the simultaneous identification and quantification of 13 β-agonist residues in bovine liver, meat, milk, kidney, poultry, and egg. Dispersive-solid phase extraction (d-SPE) using acetonitrile (ACN) was used to prepare the samples. The analyte in the extracts was separated on a reversed-phase Accucore aQ (50 mm × 2.1 mm, 2.6 μm) using a mobile phase of an aqueous solution containing 2 mM ammonium acetate and acetonitrile (ACN) 0.1 % formic acid. The method was validated in accordance with Commission Implementing Regulation (CIR) EU 2021/808 at six different concentrations ranging from 0.1 to 5 μg/kg. The mean recoveries ranged from 65 to 94 %, while repeatability and reproducibility values were all below 13 %. The linearity, as correlation coefficients (R2) ranged from 0.9955 to 0.9999. The decision limit (CCα) and detection capability (CCβ) ranges were 0.11–0.13 µg/kg and 0.12–0.15 µg/kg, respectively. The limits of detection (LOD) and limits of quantification (LOQ) were in the range of 0.004–0.048 μg/kg and 0.010–0.075 μg/kg, respectively. Of the 180 samples that were collected from local markets in Egypt, 21.11 % had β-agonist residues. The mean concentration (µg/kg) and detection frequency (%) of the most frequently found β-agonist in the samples were as follows: terbutaline (2.63 µg/kg and 90 %), ractopamine (5.14 µg/kg and 23.3 %). The method's applicability was verified by successfully completing two rounds of proficiency testing (PT).

Hybrid Paper/Polyester‐Based Laser‐Induced Graphene Electrodes for Electrochemical Detection of Tadalafil

Here, we describe for the first time the fabrication of laser‐induced graphene (LIG) electrodes on a hybrid substrate composed of sandpaper and polyester. As a proof of concept, the proposed device was used as a voltammetric sensor for tadalafil (TAD) quantification in authentic tablet samples. . The electrochemical TAD sensing based on differential pulse voltammetry (DPV) revealed a linear behavior in the concentration range from 25 to 250 μmol L‐1 (R2 = 0.99), a limit of detection of ~ 9.6 μmol L‐1, sensitivity of ~ 0.0048 µA(µmol L‐1)‐1 and acceptable reproducibility values (RSD ≤ 5.8%). The DPV responses involving the standard addition method in pharmaceutical samples presented recovery results of TAD ranging from 93 to 108%. Also, the proposed analytical method offered a suitable green analytical chemistry profile. We successfully demonstrated the fabrication of graphene‐like sites and nanoparticles composed of alumina upon a hybrid substrate.

Cardiac MRI T2 mapping with heart phase acquisition and improved motion-sensitized driven equilibrium blood suppression

Abstract Background Cardiovascular magnetic resonance (CMR) imaging relies on T2 mapping to assess myocardial tissue properties. However, T2 maps are subject to motion artifacts and signal interference, prompting exploration of techniques such as gradient-spin-echo (GraSE) sequences, heart phase acquisition, and dark blood (DB) imaging to improve image quality and reliability. Purpose This prospective study evaluates the T2 relaxation time (T2) variability and the image quality of T2 maps obtained in end-systole and end-diastole with and without fat saturation (FS), using GraSE sequence in CMR imaging. Furthermore, improved motion-sensitized driven-equilibrium (iMSDE) was compared with double inversion recovery (DIR) as an alternative DB technique. Materials and Methods Five variants of the DB GraSE sequence were developed and performed on a 1.5 Tesla MRI scanner. Forty-four healthy volunteers prospectively underwent the following sequences: GraSE in end-diastole (GraSE-ED), GraSE-ED with FS (GraSE-ED-FS), GraSE in end-systole (GraSE-ES), GraSE-ES with FS (GraSE-ES-FS), and commercial GraSE-ED (GraSE-CO). Four GraSE variants utilized iMSDE technique, while GraSE-CO used DIR for blood suppression. T2, image quality, and visual artifacts were measured. Results Ten volunteers were excluded due to image artifacts or missing datasets. Among the remaining 34 participants, the mean global T2 was measured. No significant differences were seen among all variants (P &amp;gt; .05 for all comparisons). Intra- and inter-reader agreement of global T2 values for all GraSE sequence were very good (r &amp;gt; 0.8 for both). Image quality was rated moderate or good for all variants of GraSE sequences. A lower incidence of artifacts was observed in end-systolic compared to end-diastolic imaging. Conclusion All variants of GraSE sequence are highly reproducible and myocardial T2 values did not significantly differ with heart phase. iMSDE is feasible as an alternative DB technique for T2 mapping enabling acquisition in systole, which shows a lower incidence of artifacts compared to diastole.

Cylindrical hot cathode ionisation gauge – Construction and testing

Hot cathode ionisation gauges are indispensable in measuring high and ultra-high vacuum. In the present work the construction details and the metrological evaluation of a novel gauge design — the cylindrical ionisation gauge is presented. With the aim of enhancing accuracy and stability both in the short and long term, details of the mechanical assembling of electrodes and precautions to minimize leakage currents influencing ion current measurement are described. Performance evaluations demonstrate high short-term stability, with linearity error, reproducibility, and repeatability values consistently below 1 %, placing the gauge at the same level as the most stable ionisation gauges. Operating across a pressure range of at least 6 orders of magnitude, the gauge exhibits low linearity error from high to ultra-high vacuum ranges. Its capability to measure pressures below 10−9 mbar remains open and requires further investigation.

Reliable Lift‐Off Patterning of Graphene Dispersions for Humidity Sensors

AbstractDispersion‐based graphene materials are promising candidates for various sensing applications. They offer the advantage of relatively simple and fast deposition via spin‐coating, Langmuir–Blodgett deposition, or inkjet printing. Film uniformity and reproducibility remain challenging in all of these deposition methods. Here, a scalable structuring method is demonstrated, characterized, and successfully applied for graphene dispersions. The method is based on a standard lift‐off process, is simple to implement, and increases the film uniformity of graphene devices. It is also compatible with standard semiconductor manufacturing methods. Two different graphene dispersions are investigated via Raman spectroscopy and Atomic Force Microscopy and observe no degradation of the material properties by the structuring process. Furthermore, high uniformity of the structured patterns and homogeneous graphene flake distribution is achieved. Electrical characterizations show reproducible sheet resistance values correlating with material quantity and uniformity. Finally, repeatable humidity sensing is demonstrated with van der Pauw devices, with sensing limits of less than 1% relative humidity.

Assessing the reproducibility and predictive value of objective cough measurement for successful withdrawal of invasive ventilatory support in adult patients

BackgroundUtilizing clinical tests, such as objective cough measurement, can assist in predicting the success of the weaning process in critically ill patients.MethodsA multicenter observational analytical study was conducted within a prospective cohort of patients recruited to participate in COBRE-US. We assessed the capability of objective cough measurement to predict the success of the spontaneous breathing trial (SBT) and extubation. Intra- and inter-observer reproducibility of the cough test and was evaluated using the intraclass correlation coefficient (ICC) and Cohen’s weighted kappa. We used receiver operating characteristic curves (ROC-curve) to evaluate the predictive ability of objective cough measurement.ResultsWe recruited 367 subjects who were receiving invasive mechanical ventilation. A total of 451 objective cough measurements and 456 SBTs were conducted. A significant association was found between objective cough measurement and successful SBT (OR: 1.68; 95% CI 1.48–1.90; p = 0.001). The predictive capability of the objective cough test for SBT success had a ROC-curve of 0.58 (95% CI: 0.56–0.61). Objective cough measurement to predict successful extubation had a ROC-curve of 0.61 (95% CI: 0.56–0.66). The intraobserver reproducibility exhibited an ICC of 0.94 (95% CI: 0.89–0.96; p < 0.001), while the interobserver reproducibility demonstrated an ICC of 0.72 (95% CI: 0.51–0.85; p < 0.001). The intraobserver agreement, assessed using Cohen’s weighted kappa was 0.94 (95% CI: 0.93–0.99; p < 0.001), whereas the interobserver agreement was 0.84 (95% CI: 0.67 − 0.10; p < 0.001).ConclusionsThe objective measurement of cough using the method employed in our study demonstrates nearly perfect intra-observer reproducibility and agreement. However, its ability to predict success or failure in the weaning process is limited.

Investigating the reversible nature of the magnetocaloric effect under cyclic conditions of the Ni50Mn34In15Ga1 magnetic shape memory alloy

This study explores the reversibility of the martensitic transformation (MT) and magnetocaloric (MC) response of the Ga-doped Ni50Mn35In15 magnetic shape memory alloys (MSMAs) with a Heusler structure. The direct and reverse MT occurs between temperatures TM ≈ 257 K and TA ≈ 266 K, respectively. The large MC effects resulting from the magnetic-field-induced first-order MT render these materials promising for room-temperature magnetic refrigeration. On account of both a low thermal hysteresis of MT (ΔThyst = 4 K) at a magnetic field of 2 T and a highly reproducible peak value of the adiabatic temperature change at MT (|∆Tad| ≈ 1.3 K for µ0H = 1.9 T), Ni50Mn34In15Ga1 MSMA emerges as a benchmark material for studying a cyclic stability of MC effects. During the first magnetic switching cycle, a reduction of ∆Tad at MT by approximately 1.3 is observed, significantly lower than the reported one for other MC materials undergoing similar first-order phase transitions. Subsequent cycles revealed a consistent stability of the magnetic-field-induced ∆Tad even after more than 200 magnetic field switching cycles. These findings suggest a notable degree of reversibility of the MT in the studied MSMA, which was also confirmed in the present work by a Temperature-First Order Reverse Curve distribution analysis.

Effect of anti-VEGF on retinal blood flow in diabetic mice using laser speckle flowgraphy.

To assess intra- (repeatability) and inter-observer (reproducibility) variability of laser speckle flowgraphy (LSFG) for retinal blood flow (RBF) measurement in 20 eyes of wild type (C57BL/6J) mice and effect of intravitreal Aflibercept on RBF in optic nerve head (ONH) region of 10 eyes of Ins2 (Akita) diabetic mice. 'Mean blur rate (MBR)' was measured for all quadrants of tissue area (MT), vessel (MV) and total area (MA) of ONH region. Changes in MT were analysed at each timepoint. Repeatability was evaluated by measuring MBR variability without changing mouse head position, and reproducibility after resetting mouse head position by another operator. Coefficient of repeatability (CR) through Bland-Altman plot method coefficient of variation (COV) and Intraclass correlation coefficient (ICC) was calculated. Intravitreal Aflibercept (1 μg) was administered to Akita eyes and intraocular pressure (IOP) was measured using a tonometer at baseline, day 7, 14, 21 and 28 post-injection. Hurvich and Tsai's criterion was used. Coefficient of repeatability values of repeatability and reproducibility for all quadrants were within limits of agreement. Reliability was excellent (ICC 0.98-0.99) and reproducibility was moderate to excellent (ICC 0.64-0.96). There was a non-significant IOP increase in all Akita eyes at Day 28 (p > 0.05), and significant increase in MT in all quadrants at Day 21 and superior, inferior and temporal quadrants at Day 28 (p < 0.05). Laser speckle flowgraphy demonstrates excellent repeatability and moderate to excellent reproducibility in measuring RBF. Intravitreal Aflibercept injection results in a significant increase in MT up to 28 days post-injection without significant increase in IOP.

Modeling of gas sensor based on zinc oxide thin films by feedback loop using operational amplifier

Nanostructured Zincoxide thin-film is widely used as a sensing material because of its tunable surface microstructure and wide optical bandgap but synthesizing a film with desired value of resistance and reproducibility of film is challenging, particularly by chemical method. In this work, we showed how a ZnO film of arbitrary resistance can be used as a sensor without application of heat using operational amplifier. Zinc oxide thin film was synthesized by using the Sol-gel method (Spin coating) and was characterized by XRD and SEM which revealed wurtzite polycrystalline nature of Zinc oxide film with average grain size 17–25 nm. In this report, we designed a noble electronic circuit capable of detecting analyte gas molecule even if very small change in film resistance occurs due to the influence of gas molecule. In recently available sensors, the quality of the film degrades over time due to repeated heating and cooling, resulting in a reduced lifetime for the sensor. To address this issue and achieve higher sensitivity, as well as to fabricate an affordable, portable, precise, energy-efficient and durable device, this electronic model offers advantages over classical temperature-dependent sensors.