Peak Enhancement Research Articles

Application of dynamic contrast enhanced ultrasound analysis in predicting early response to systemic therapy of intrahepatic cholangiocarcinoma

ObjectiveTo evaluate the value of dynamic contrast-enhanced ultrasound (DCE-US) analysis in early prediction of tumor response to systemic treatment in patients with intrahepatic cholangiocarcinoma (ICC). Patients & MethodsIn this retrospective study, patients diagnosed with ICC by core needle biopsy and histopathological results were included. All patients were diagnosed as advanced stages (stage III/IV) by the 8th edition of the American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) TNM staging system. Liver contrast-enhanced ultrasound (CEUS) examination, DCE-US analysis, CT/MRI, and blood tests were performed in all patients before and 2 months after systemic treatment. CEUS procedure was performed using an ultrasound system (ACUSON Sequoia; Siemens Medical Solutions, Germany) equipped with a 5C1 MHz convex array transducer. Time-intensity curves (TIC) and quantitative parameters were created with VueBox software. According to one-year results of the modified Response Evaluation Criteria in Solid Tumors (m-RECIST) based on CT/MRI, patients were divided into the responder group (RG) and the non-responder group (NRG). Before and 2 months after systemic therapy, the DCE-US perfusion parameters was compared using the paired-sample t test and the Wilcoxon test. ResultsFrom September 2020 to December 2021, a total of 24 patients diagnosed with advanced ICC were included (11 males, 13 females, mean age 59.4 ± 1.8 years). According to the one year of m-RECIST results, 17 cases (70.8 %) were classified as non-responders by the final m-RECIST criteria, while 7 cases (19.2 %) were responders. Comparing before and 2 months after therapy, the RG took longer time to reach peak intensity, and the peak intensity of TIC was lower. While the TICs of NRG revealed faster enhancement after therapy. Among all DCE-US quantitative parameters, PE (peak enhancement), WiR (wash-in rate), WiPI (wash-in perfusion index) and WoR (wash-out rate) reduced significantly following 2 months of systemic therapy in RG (P < 0.05). Comparing to RG, PE and WiPI decreased slightly 2 months after therapy in NRG (P < 0.05). ConclusionsThe DCE-US analysis with quantitative parameters has the potential value to make early and quantitative evaluation of treatment response to systemic therapy in ICC patients.

Application of Dynamic Contrast-Enhanced Ultrasound in Evaluation the Activity of Crohn's Disease.

The dynamic assessment of disease activity during the follow-up of patients with Crohn's disease (CD) remains a significant challenge. In this study, we aimed to identify the role of dynamic contrast-enhanced ultrasound (DCE-US) in the evaluation of activity of CD. In the retrospective study, patients diagnosed with CD in our hospital were included. All the diagnoses were confirmed by clinical symptoms and ileocolonoscopical results. All patients underwent intestinal ultrasound and contrast-enhanced ultrasound (CEUS) examinations within 1 week of the ileocolonoscopy examinations. Acuson Sequoia (Siemens Healthineers, Mountain View, CA, USA) and Resona R9 Elite (Mindray Medical Systems, China) with curved array and Line array transducers were used. The CEUS examination was performed with SonoVue (Bracco SpA, Milan, Italy). DCE-US analysis was performed by UltraOffice (version: 0.3-2010, Mindray Medical Systems, China) software. Two regions of interest (ROIs) were set in the anterior section of the infected bowel wall and its surrounding normal bowel wall 2 cm distant from the inflamed area. Time-intensity curves (TICs) were generated and quantitative perfusion parameters were obtained after curve fittings. The Simple Endoscopic Score for Crohn's disease (SES-CD) was regarded as the reference standard to evaluate the activity of CD. The receiver operating characteristic curve (ROC) analyses were used to determine the diagnostic efficiency of DCE-US quantitative parameters. From March 2023 to November 2023, 52 CD patients were included. According to SES-CD score, all patients were divided into active group with the SES-CD score > 5 (n = 39) and inactive group SES-CD score < 5 (n = 13). Most of the active CD patients showed bowel wall thickness (BWT) > 4.2 mm (97.4%, 38/39) or mesenteric fat hypertrophy (MFH) on intestinal ultrasound (US) scan (69.2%, 27/39). Color Doppler signal of the bowel wall mostly showed spotty or short striped blood flow signal in active CD patients (56.4%, 22/39). According to CEUS enhancement patterns, most active CD patients showed a complete hyperenhancement of the entire intestinal wall (61.5%, 24/39). The TICs of active CD showed an earlier enhancement, higher peak intensity, and faster decline. Among all CEUS quantitative parameters, amplitude-derived parameters peak enhancement (PE), wash-in area under the curve (WiAUC), wash-in rate (WiR), wash-in perfusion index (WiPI), and wash-out rate (WoR) were significantly higher in active CD than in inactive CD (p < 0.05). The combined AUROC of intestinal ultrasound features and DCE-US quantitative perfusion parameters in the diagnosis of active CD was 0.987, with 97.4% sensitivity, 100% specificity, and 98.1% accuracy. DCE-US with quantitative perfusion parameters is a potential useful noninvasive imaging method to evaluate the activity of Crohn's disease.

Evaluation of utero-placental vascularization using contrast-enhanced ultrasound: Early first trimester maternal perfusion of the intervillous space is confirmed

IntroductionThe objective was to confirm and semiquantify the maternal perfusion of the intervillous space between 8 and 13 + 6 gestational weeks (GW). MethodsWe conducted a prospective, multicenter, and nonrandomized open study. Women undergoing voluntary termination of pregnancy at three different gestational ages (Group 8 GW: 8 to 8 + 6 GW, Group 11GW: 11 to 11 + 6 GW and Group 13GW: 13 to 13 + 6 GW) were included, with 14 subjects per group. Women presenting with a personal risk of preeclampsia and/or intrauterine growth restriction were excluded. Contrast-enhanced ultrasound (CEUS) was performed with an intravenous bolus administration of 2.4 mL of microbubbles. The region of interest (ROI) was the entire placenta. The perfusion curves and kinetic parameters, including wash-in perfusion index, peak enhancement and mean transit time, were calculated. ResultsOf the 42 women initially included, interpretable perfusion curves could be obtained for 33. Regardless of the gestational age, contrast was observed in the entire placenta. No significant difference in perfusion parameters was observed between groups. There was an association between signal intensity and both maternal heart frequency and placental location. Signal intensity was decreased when the heart frequency increased (p < 0.05) and when the placenta was in a nonanterior position (p > 0.005). DiscussionWe confirmed the presence of maternal perfusion of the intervillous space as early as 8 GW. No significant increase in perfusion parameters was observed between 8 and 13 + 6 GW. Our observations, in accordance with the previous experiment published by Roberts et al.1, strongly challenge the classic trophoblastic plug theory.

Automated Quantitative Analysis of CT Perfusion to Classify Vascular Phenotypes of Pancreatic Ductal Adenocarcinoma

CT perfusion (CTP) analysis is difficult to implement in clinical practice. Therefore, we investigated a novel semi-automated CTP AI biomarker and applied it to identify vascular phenotypes of pancreatic ductal adenocarcinoma (PDAC) and evaluate their association with overall survival (OS). Methods: From January 2018 to November 2022, 107 PDAC patients were prospectively included, who needed to undergo CTP and a diagnostic contrast-enhanced CT (CECT). We developed a semi-automated CTP AI biomarker, through a process that involved deformable image registration, a deep learning segmentation model of tumor and pancreas parenchyma volume, and a trilinear non-parametric CTP curve model to extract the enhancement slope and peak enhancement in segmented tumors and pancreas. The biomarker was validated in terms of its use to predict vascular phenotypes and their association with OS. A receiver operating characteristic (ROC) analysis with five-fold cross-validation was performed. OS was assessed with Kaplan–Meier curves. Differences between phenotypes were tested using the Mann–Whitney U test. Results: The final analysis included 92 patients, in whom 20 tumors (21%) were visually isovascular. The AI biomarker effectively discriminated tumor types, and isovascular tumors showed higher enhancement slopes (2.9 Hounsfield unit HU/s vs. 2.0 HU/s, p &lt; 0.001) and peak enhancement (70 HU vs. 47 HU, p &lt; 0.001); the AUC was 0.86. The AI biomarker’s vascular phenotype significantly differed in OS (p &lt; 0.01). Conclusions: The AI biomarker offers a promising tool for robust CTP analysis. In PDAC, it can distinguish vascular phenotypes with significant OS prognostication.

Proposal for composite quantum electromagnetically induced transparency heat engine coupled by a nanomechanical mirror

Abstract This paper introduces a quantum heat engine model that utilizes an ultracold atomic gas coupled with a nanomechanical mirror. The mirror’s vibration induces an opto-mechanical sideband in the control field, affecting the behavior of the cold gas and subsequently influencing the output radiation of the engine. The model incorporates mirror vibration while omitting cavity confinement, establishing a bridge between a multi-level atom–laser interacting system that plays with coherences and the mechanical vibration of the nanomechanical mirror, which jointly function as heat engines. Three distinct heat engine configurations are proposed: the first involves a vibration-free three-level Λ-type system, the second introduces nanomechanical vibration to the three-level Λ-type system, and the third constitutes a composite engine that combines the previous setups along with nanomechanical vibration. The spectral brightness of a three-level heat engine is diminished with mirror vibration, whereas for a composite heat engine, there is a slight enhancement in the brightness peak. However, the maximum brightness is attained when there is no vibration. Comparisons between the proposed model and an ideal system are made regarding entropy balance, adhering to the constraints of the second law of thermodynamics. The model observed that when subjected to mirror vibration, the proposed heat engines diverged from the characteristics expected in an ideal heat engine.

P482 Diagnostic accuracy of contrast-enhanced ultrasound for fibrotic strictures of Crohn’s disease: a systematic review and meta-analysis of individual participant data

Abstract Background Crohn's disease (CD) often leads to the development of intestinal strictures, requiring effective differentiation between inflammatory and fibrotic for the optimal treatment strategies. Despite recent advances in drug development targeting fibrosis, current evaluation methods remain insufficient. Contrast-enhanced ultrasound (CEUS) is a promising modality for assessing vascularity and inflammation, yet its accuracy in fibrosis detection needs more validation. Methods A systematic review and meta-analysis were conducted using IPD to determine the diagnostic accuracy of CEUS in identifying intestinal fibrosis in CD. Our search included databases such as MEDLINE, EMBASE, and Web of Science up until March 23, 2023. Inclusion criteria required a confirmed diagnosis of CD and studies that evaluated the accuracy of CEUS parameters, including total area under the curve (AUC), wash-in AUC, wash-out AUC, peak enhancement, wash-in perfusion index, wash-in rate, wash-out rate, rise time, fall time, and mean transit time related to fibrosis in CD (Figure 1 (A)). The quality of included studies was assessed using the QUADAS-2 tool, with each study mandatorily using surgical specimen pathology as a reference standard in at least one instance. Results Our qualitative synthesis included eight studies encompassing 306 patients. These studies were generally assessed to have a high risk of bias. It is important to note that while peak enhancement and AUC were frequently examined across studies, neither parameter had established absolute cutoff values for the diagnosis of fibrosis. From the three studies where IPD was available, detailed data from 80 patients were included in the meta-analysis (colon n=11 and small bowel n= 69). Among them, 54 underwent surgical intervention with fibrosis being confirmed in 31. The highest diagnostic accuracy was observed for total AUC and wash-in AUC, with pooled sensitivity and specificity for predicting fibrosis at 0.86 (95% CI, 0.59–0.97) and 0.25 (95% CI, 0.03–0.76), respectively (Figure 1 (B)). Conclusion This meta-analysis with IPD pioneers the exclusive evaluation of CEUS for fibrotic strictures in CD. It reveals a significant risk of bias in the primary research and a notable absence of consensus on the CEUS parameters' threshold values for distinguishing fibrosis from inflammation. The observed low specificity highlights the need for innovative strategies in future research, such as integrating CEUS with techniques like elastography, to enhance the precision of fibrosis detection in CD. PROSPERO 2020 CRD42020214472. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020214472

Radiomics-Based Machine Learning Classification Strategy for Characterization of Hepatocellular Carcinoma on Contrast-Enhanced Ultrasound in High-Risk Patients with LI-RADS Category M Nodules.

Objective Accurate differentiation within the LI-RADS category M (LR-M) between hepatocellular carcinoma (HCC) and non-HCC malignancies (mainly intrahepatic cholangiocarcinoma [CCA] and combined hepatocellular and cholangiocarcinoma [cHCC-CCA]) is an area of active investigation. We aimed to use radiomics-based machine learning classification strategy for differentiating HCC from CCA and cHCC-CCA on contrast-enhanced ultrasound (CEUS) images in high-risk patients with LR-M nodules. Methods A total of 159 high-risk patients with LR-M nodules (69 HCC and 90 CCA/cHCC-CCA) who underwent CEUS within 1 month before pathologic confirmation from January 2006 to December 2019 were retrospectively included (111 patients for training set and 48 for test set). The training set was used to build models, while the test set was used to compare models. For each observation, six CEUS images captured at predetermined time points (T1, peak enhancement after contrast injection; T2, 30 seconds; T3, 45 seconds; T4, 60 seconds; T5, 1-2 minutes; and T6, 2-3 minutes) were collected for tumor segmentation and selection of radiomics features, which included seven types of features: first-order statistics, shape (2D), gray-level co-occurrence matrix, gray-level size zone matrix, gray-level run length matrix, neighboring gray tone difference matrix, and gray-level dependence matrix. Clinical data and key radiomics features were employed to develop the clinical model, radiomics signature (RS), and combined RS-clinical (RS-C) model. The RS and RS-C model were built using the machine learning framework. The diagnostic performance of these three models was calculated and compared. Results Alpha-fetoprotein (AFP), CA19-9, enhancement pattern, and time of washout were included as independent factors for clinical model (all p < 0.05). Both the RS and RS-C model performed better than the clinical model in the test set (area under the curve [AUC] of 0.698 [0.571-0.812] for clinical model, 0.903 [0.830-0.970] for RS, and 0.912 [0.838-0.977] for the RS-C model; both p < 0.05). Conclusions Radiomics-based machine learning classifiers may be competent for differentiating HCC from CCA and cHCC-CCA in high-risk patients with LR-M nodules.

Exploring Epitaxial Structures for Electrically Pumped Perovskite Lasers: A Study of CsPb(Br,I)3 Based on the Ab Initio Bethe-Salpeter Equation.

Halide perovskites are widely used as components of electronic and optoelectronic devices such as solar cells, light-emitting diodes (LEDs), optically pumped lasers, field-effect transistors, photodetectors, and γ-detectors. Despite this wide range of applications, the construction of an electrically pumped perovskite laser remains challenging. In this paper, we numerically justify that mixing two perovskite compounds with different halide elements can lead to optical properties suitable for electrical pumping. As a reference, the chosen model material was CsPbBr3, whose performance as a part of lasers has been widely recognised, with some Br atoms substituted by I at specific sites. In particular, a strong enhancement of the low-energy absorption peaks has been obtained using the ab initio Bethe-Salpeter equation. Based on these results, we propose specific architectures of ordered doping that could be realised by epitaxial growth. Efficient light emission from the bottom of the conduction band is expected.

Pulsating nanofluid-jet impingement cooling and its hydrodynamic effects on heat transfer

Unlocking optimum heat transfer is essential for enhancing solar thermal collector efficiency and advancing sustainable energy solutions. This experimental study investigates a simulated solar thermal collector's heat transfer behavior using jet impingement cooling, emphasizing hydrodynamic effects in pulsating nanofluid-jet impingement. Al2O3-MWCNT/water hybrid nanofluid is utilized, varying pulsating frequency (0.2 Hz ≤ F ≤ 20 Hz), amplitude (4 Vp ≤ A ≤ 20 Vp), waveform (sine, squared, triangular), wave offset (0 ≤ Ⴋ ≤ 4), and nanofluid volume fraction (0.05 vol% ≤ φ ≤ 0.3 vol%) to optimize heat transfer. Results show a significant influence on heat transfer performance for all parameters except waveform. A peak heat transfer enhancement of 24 % is observed for 0.3 vol% Al2O3-MWCNT/water compared to de-ionized water under continuous jet impingement. Additionally, a 20 % enhancement is achieved with a sine waveform at φ = 0.3 vol%, F = 0.2, A = 8, and Ⴋ = 2. Pulsating jet impingement generally yields higher cooling rates, as the cooling curves indicate. These findings provide crucial insights for optimizing heat transfer in solar thermal collectors through pulsating hybrid nanofluid jet impingement cooling.

Sb3+-Doped Indium-Based Metal Halide (Gua)3InCl6 with Efficient Yellow Emission.

In recent years, low-dimensional organic-inorganic hybrid metal halides (OIHMHs) have shown excellent photophysical properties due to their quantum structure, adjustable energy levels, and energy transfer between inorganic and organic components, which have attracted extensive attention from researchers. Herein, we synthesize a zero-dimensional (0D) OIHMH, Sb3+:(Gua)3InCl6, by introducing Sb3+ into (Gua)3InCl6, which undergoes a significant enhancement of the emission peak at 580 nm with the photoluminescence quantum yield (PLQY) boosted from 17.86 to 95.72% when excited at 340 nm. This boost in photoluminescence of the doped sample was studied by combining ultrafast femtosecond transient absorption, temperature-dependent photoluminescence (PL) spectra, and density functional theory (DFT) calculation, revealing the process of self-trapped exciton (STE) recombination to emit light at both Sb and In sites in this 0D structure simultaneously. This material with the lowest dark STE level at the In site for emission in the undoped sample can amazingly yield very strong emission in the doped sample, which has never been observed before. Finally, we tested its application in a photoelectric device. This work not only helps to gain a deeper understanding of the formation of STEs in In-based halides but also plays a certain guiding role in the design of new luminescent materials.

Energy spectra of the first TGE observed on Zugspitze by the SEVAN light detector compared with the energetic TGE observed on Aragats

The energy spectra of Thunderstorm ground enhancement (TGE) electrons and gamma rays are the key evidence for proving the origin of enhanced particle fluxes from thunderclouds. Till now, the electron energy spectrum was measured only by the Aragats large scintillation spectrometer ASNT. We changed the electronics board of the SEVAN detector installed at the Umwelt-Forschungs-Station (UFS, Schneefernerhaus, 2650 m asl) to allow these vital measurements near the top of the Zugspitze. The new electronics of the SEVAN detector, supplied with logarithmic ADC, for the energy release measurements up to 50 MeV (the thickness of the spectrometric scintillator is 25 cm). Thus, by measuring energy releases well above 3 MeV, we unambiguously separate Radon progeny gamma radiation from the electrons and gamma-ray relativistic runaway avalanches. Using the different energy release histograms allows for separating charged and neutral particles, enabling the disentangling of electron and gamma-ray energy spectra. On May 23, 2023, the first TGE was registered on Zugspitze by the SEVAN detector. The gamma-ray flux enhancement was 44%, corresponding to the observed count rate peak enhancement of 44σ. The gamma-ray energy spectrum was recovered, maximum energy is 60 MeV. On the same day, a large TGE was observed on Aragats. The TGE maximum flux overpasses the fair-weather flux by 207%, equivalent to a 1-minute peak significance of 400σ. Maximum energy of electrons is 50 MeV, gamma rays – 45 MeV. In this context, we will explore and explain the new capabilities of the SEVAN detector installed on Zugspitze and the rearranged similar detector on Aragats. We also present and compare electron and gamma-ray energy spectra from Aragats TGE and gamma-ray energy spectrum from Zugspitze.

Glucagon-Like-Peptide-2 Stimulates Lacteal Contractility and Enhances Chylomicron Transport in the Presence of an Intact Enteric Nervous System

Secretion and transport of intestinal chylomicrons (CMs) via lymphatics to the blood circulation is stimulated primarily by fat ingestion, whereas several other factors have also been shown to play important roles in regulating CM secretion rate. Among these factors, active regulation of lymphatic pumping has not been appreciated to date. The gut peptide and intestinal growth factor glucagon-like peptide-2 (GLP-2) has emerged as a robust enhancer of intestinal lipid mobilization and secretion. The present study aims to elucidate GLP-2's impact on lacteal contractility and assess enteric nervous system (ENS) involvement in GLP-2-induced effects on lipid mobilization. Using intravital imaging of a prospero-related homeobox 1-enhanced green fluorescent protein rat model, we assessed GLP-2's effect on lacteal contractility, in the presence and absence of the ENS inhibitor mecamylamine (MEC). Concurrently, to explore the physiological relevance, we examined GLP-2's impact on lymph flow and triglyceride (TG) output invivo in a rat lymph fistula model. GLP-2 significantly increased lacteal contractility, and this effect was inhibited by MEC. In the rat lymph fistula model, GLP-2 increased lymph flow, lymph volume, cumulative lymph volume, and TG output while reducing lymph TG concentration. MEC administration blocked these effects of GLP-2. Peak enhancement of lacteal contractility and enhancement of lymph flow invivo occurred simultaneously with maximal effect at 15-20 minutes post GLP-2 administration, suggesting that GLP-2 enhances lipid transport by stimulating lymphatic contractility. For the first time, through imaging and concurrent rat lymphatic fistula studies, we demonstrated active regulation of lymphatic contractility as a key determinant of CM secretion and that intact ENS was required to observe this effect.

Synergetic effect of magnetic field location, strength and orientation on heat transfer characteristics of brine-based hybrid nanofluid in rectangular confinement

The hybrid nanofluid emergence is presently receiving untold research attention as an improved cooling medium. This paper presents an investigation into the free convection thermal transport performance of brine (ethylene glycol-deionized water (60:40 vol%)-based hybrid ferrofluid (Fe2O3-Al2O3) (BBHF) in a rectangular cavity under steady-state conditions with and without magnetic inducement. The synergetic effect of different magnetic field orientations and intensities imposed on the various walls of the confinement and their influence on the heat transfer characteristics of BBHF was examined. At volume concentrations of 0.05–0.40 %, the BBHF was formulated and characterised for its viscosity, stability, morphology, and thermal conductivity. Without a magnetic stimulus, the average Nusselt number, heat transfer rate, and coefficient of heat transfer of 0.05–0.2 vol% BBHF samples were improved relative to the brine. At a cavity temperature gradient of 35 °C using 0.05 vol% BBHF, a peak thermal transport enhancement of 10.09 % was observed when compared with the brine. With 0.05 vol% BBHF, the vertical positioning of the magnetic stimulus on the cavity side wall was noticed to yield maximum improvement of heat transfer (4.3 %). An increment in the strength of the magnetic stimulus from 4.89 mT to 13.00 mT enhanced thermal transport by >15 %, which subsequently deteriorated when increased to 21.95 mT for all the studied magnetic stimulus arrangements. In addition, correlations were proposed to predict the Nusselt number, thermal conductivity, and viscosity of the BBHFs. The employment of hybrid nanoparticles, magnetic stimulus, and different arrangements of the magnetic stimulus was observed to amplify the heat transfer of BBHFs in the cavity which is of practical and engineering benefit.

Evaluation of renal ischemia–reperfusion injury using CEUS in mice

BackgroundRenal ischemia–reperfusion injury (IRI) frequently occurs clinically. We investigated the value of contrast-enhanced ultrasonography (CEUS) in the evaluation of renal IRI levels in mice.MethodsThirty-six healthy adult male C57BL/6 mice (20–22 g) were randomly divided into the sham, 10 min, 20 min, 30 min, 40 min, and 50 min groups based on the time of renal warm ischemia by blocking the left renal pedicle, approved by the Institutional Animal Ethics Committee. Time-intensity curve (TIC)-derived parameters such as peak enhancement (PE) and wash-in perfusion index (WiPI) were produced using CEUS at 1 h and 24 h after IRI. The severity of kidney injury was detected by the renal tubular necrosis rate which was analyzed by hematoxylin and eosin staining at 24 h after IRI. The Spearman correlation coefficient was used to describe the correlations between PE and WiPI values and the renal tubular necrosis rate.ResultsThe PE and WiPI values decreased after IRI in the groups with a warm ischemia time ≥ 20 min. The renal tubular necrosis rate was significantly correlated with the PE value at 1 h (ρ = -0.802) and 24 h (ρ = -0.861) after IRI and the WiPI value at 1 h (ρ = -0.814) and 24 h (ρ = -0.853) after IRI (all p < 0.001).ConclusionTIC-derived parameters, including PE and WiPI values, can be used to evaluate the severity of renal IRI in mice. CEUS is a safe and effective technology for the detection of renal IRI.Relevance statementCEUS can evaluate the severity of renal ischemia–reperfusion injury by peak enhancement and wash-in perfusion index values selected from various time-intensity curve-derived parameters.Key points• Contrast-enhanced ultrasonography can evaluate the level of renal ischemia–reperfusion injury.• Peak enhancement and wash-in perfusion index are correlated with the renal tubular necrosis rate.• CEUS can detect changes in unilateral renal function without radiation.Graphical

MAGNETIC RESONANCE IMAGE DENOIZING USING A DUAL-CHANNEL DISCRIMINATIVE DENOIZING NETWORK

Magnetic Resonance Imaging (MRI) provides detailed information about soft tissues, which is essential for disease analysis. However, the presence of Rician noise in MR images introduces uncertainties that challenge medical practitioners during analysis. The objective of our research paper is to introduce an innovative dual-channel deep learning (DL) model designed to effectively denoize MR images. The methodology of this model integrates two distinct pathways, each equipped with unique normalization and activation techniques, facilitating the creation of a wide range of image features. Specifically, we employ Group Normalization in combination with Parametric Rectified Linear Units (PRELU) and Local Response Normalizations (LRN) alongside Scaled Exponential Linear Units (SELU) within both channels of our denoizing network. The outcomes of our proposed network exhibit clinical relevance, empowering medical professionals to conduct more efficient disease analysis. When evaluated by experienced radiologists, our results were deemed satisfactory. The network achieved a noteworthy improvement in performance metrics without requiring retraining. Specifically, there was a (6.65 ± 0.03)% enhancement in Peak Signal-to-Noise Ratio (PSNR) values and a (3.9 ± 0.02)% improvement in Structural Similarity Index (SSIM) values. Furthermore, when evaluated on the dataset on which the network was initially trained, the increase in PSNR and SSIM values was even more pronounced, with a (7.5 ± 0.02)% improvement in PSNR and a (4.3 ± 0.01)% enhancement in SSIM. Evaluation metrics, such as SSIM and PSNR, demonstrated a notable enhancement in the results obtained using our network. The statistical significance of our findings is evident, with p-values consistently less than 0.05 (p &lt; 0.05). Importantly, our network demonstrates exceptional generalizability, as it performs remarkably well on different datasets without the need for retraining.

Renal elasticity and perfusion changes on ultrasonography in an early-stage diabetic rat model.

Renal hemodynamic changes in early diabetes occur before the onset of significant structural abnormalities or clinical manifestations, and timely detection of these changes has clinical significance. This study aimed to evaluate renal elasticity and perfusion changes in an early-stage diabetic rat model by shear wave elastography (SWE) and contrast-enhanced ultrasound (CEUS), and to explore the potential correlations between renal elasticity and perfusion parameters. A total of 18 male Sprague-Dawley rats were randomly divided into three groups: a control group (group 1, n=6), a diabetic group (group 2, n=6), and a diabetic group receiving drug therapy (group 3, n=6). An intraperitoneal injection of streptozotocin (STZ) for 2 days combined with a high-fat diet (HFD) was used as the early-stage diabetic rat model. The diabetic rats in group 3 were treated with canagliflozin and losartan for 6 weeks, whereas the rats in groups 1 and 2 were given equal amounts of purified water. Renal stiffness on SWE and perfusion parameters on CEUS were measured and compared among the three groups, then the rats were sacrificed, and serum, urine, and renal histopathology were evaluated to confirm the development of early diabetes. The early-stage diabetic rats without significant pathological changes exhibited bigger kidneys and higher blood glucose (all P<0.05). Among the CEUS parameters, peak enhancement (PE), wash-in area under the curve (WiAUC), wash-in perfusion index (WiPI), wash-out AUC (WoAUC), wash-in and wash-out AUC (WiWoAUC), rise time (RT), and time to peak (TTP) of diabetic rats in group 2 were significantly increased (all P<0.05), and the hyperperfusion ameliorated significantly after drug treatment. The renal elasticity measured by SWE varied in accordance with certain perfusion parameters, and was strongly positively correlated with WiAUC (r=0.701, P<0.001), WoAUC (r=0.647, P<0.001), and WiWoAUC (r=0.655, P<0.001), and moderately positively correlated with PE (r=0.539, P=0.001), WiPI (r=0.555, P<0.001), RT (r=0.425, P=0.010), and TTP (r=0.439, P=0.007). Renal elasticity and perfusion changes in the early stage of diabetes, and renal elasticity was positively associated with delayed and increased perfusion.

Thrombomodulin Protects Against Cell-Free Hemoglobin Mediated Acute Kidney Injury in Sickle Cell Anemia

Thrombomodulin (TM) is a transmembrane protein that plays a pivotal role in maintaining microvascular health. Functions of TM include 1) binding thrombin and inhibiting its interaction with fibrinogen, 2) augmenting protein C function, and 3) down-regulating complement activation. Reduced TM function has been implicated in several thrombotic microangiopathies, including atypical hemolytic uremic syndrome and disseminated intravascular coagulation (DIC) (PMID 29866818). Previous in vitro studies have demonstrated that cell-free hemoglobin (Hb) mediates loss of TM from the endothelial surface which, in turn, is associated with a higher risk of kidney injury in patients with sickle cell disease (PMID 34929051). Infusion of intact, soluble TM may restore TM's function in the microvasculature, as observed in critically ill patients with DIC (PMID 17059423). In transgenic sickle mice (Townes model, Jackson Laboratory; Bar Harbor, Maine), we investigated whether 1) cell-free Hb reduces TM function leading to glomerular endothelial and kidney injury and 2) if infusion of intact, soluble TM (Asahi Kasei Pharma ©; Tokyo, Japan) can restore TM function and reduce the toxic effects of cell-free Hb in the kidney. Sickle mice (4 male, 4 females per condition) were challenged with cell-free Hb (0.24g/kg intravenous [iv]) or normal saline followed 2 hours later by either infusion of TM (5mg/kg subcutaneous, 1mg/kg iv) or normal saline. Blood and urine samples were collected 24 hours after the challenge and the mice were sacrificed for histopathologic evaluation. In a separate set of similar experiments, sickle mice (3 males, 3 females per condition) received iv microbubbles (Vevo MicroMarker TM Contrast) 24 hours after the challenge to assess renal cortical blood flow by contrast-enhanced ultrasound (Vevo2100 system). Mean ± standard error of mean values are provided. Comparisons between Hb-only and Hb+TM conditions were made using the Mann-Whitney test. Vasculopathy: Infusion of cell-free Hb resulted in decreased TM antithrombotic function within the glomerulus; infusion of TM 2 hours after the challenge restored these functions (fibrinogen relative fluorescent intensity [RFI]: control, 24.2 ± 0.9; Hb-only, 40.6 ± 1.7; Hb+TM: 26.8 ± 1.6) and anti-complement function (C3 RFI: control, 12.9 ± 0.4; Hb-only, 19.3 ± 1.4; Hb+TM, 14.1 ± 0.5) (P≤0.007). Circulating vascular injury biomarkers rose in the cell-free Hb challenged sickle mice and this was abated with TM rescue for p-selectin (control, 271 ± 25 ng/mL; Hb-only, 533 ± 47 ng/mL; Hb+TM, 356 ± 34 ng/mL), VEGF (control, 59 ± 4 pg/mL; Hb-only, 93 ± 7 pg/mL; Hb+TM 69 ± 3 pg/mL), and vWF (control: 91 ± 9 ng/mL, Hb-only: 299 ± 31 ng/mL, Hb+TM: 183 ± 22 ng/mL) (P≤0.01). Kidney Damage: Urine biomarkers of tubular injury increased after the cell-free Hb challenge and improved with TM (KIM-1: control, 317 ± 66 pg/day; Hb-only, 1201 ± 142 pg/day; Hb+TM, 638 ± 78 pg/day; P=0.003) (NGAL: control, 234 ± 34 ng/day; Hb-only, 1624 ± 145 ng/day; Hb+TM, 767 ± 118 ng/day; P=0.003). An elevation in serum creatinine concentration is used to define acute kidney injury. The cell-free Hb challenge led to an acute rise in serum creatinine while the TM rescued mice had serum creatinine concentrations that were significantly lower than the Hb-only challenged mice (P=0.03) and similar to the control conditions (Figure 1A). Preliminary testing of TM administered 24 hours after the cell-free Hb challenge has also led to kidney protective effects as assessed by serum creatinine, p-selectin, and vWF (P &amp;lt; 0.05). Cortical Blood Flow: Peak enhancement, a measure of relative blood volume, was reduced in the cell-free Hb challenged mice compared to control conditions by contrast-enhanced ultrasound. The TM-rescued mice had improved peak enhancement compared to the Hb-only treated mice (P=0.03) and similar to control conditions (Figure 1B). In conclusion, cell-free Hb reduces TM function resulting in increased vascular and kidney injury and decreased cortical blood flow. Infusion of soluble TM 2 hours after the cell-free Hb challenge restores TM function, protects against vascular and kidney injury, and preserves cortical blood flow. Our data highlights TM as a potential candidate therapy to preserve vascular function and abate kidney injury in patients with sickle cell disease during severe vaso-occlusive or hyperhemolytic episodes, when concentrations of cell-free Hb increase several fold.

Nonlinear compression of naturally down-chirped superradiance pulses from a free-electron laser oscillator by thick germanium plates.

Naturally down-chirped superradiance pulses, with mirco-pulse energy, peak wavelength, and micropulse duration of 40 µJ, 8.7 μm, and 5.1 optical cycles, respectively, emitted from a free-electron laser (FEL) oscillator were nonlinearly compressed down to 3.7 optical cycles using a 30-mm-thick Ge plate. The peak power enhancement owing to nonlinear compression was found to be 40%. The achieved peak power and pulse duration were comparable to those of recently developed high-intensity and few-cycle long-wavelength infrared sources based on solid-state lasers. FEL oscillators operating in the superradiance regime can serve as unique tools for studying strong-field physics in long-wavelength infrared regions.

Experimental study and ANFIS modelling of the thermophysical properties and efficacy of GNP-Al2O3 hybrid nanofluids of different concentrations and temperatures

This study delves into an extensive investigation of the thermophysical properties and heat transfer efficacy of a hybrid nanofluid incorporating graphene nanoplatelets and γ-Al2O3 nanoparticles dispersed in deionised water. The nanofluids were characterised for their viscosity (µ), thermal conductivity (λ), and electrical conductivity (σ) over a 15–40 °C temperature range for varying nanoparticle loading (0.1–0.4 vol%). The experimental results revealed notable enhancements in µ, λ, and σ with increasing nanoparticle concentration, while µ decreased at elevated temperatures as λ and σ increased. At the highest concentration (0.4 vol%), µ increased by 21.74%, while λ and σ exhibited peak enhancements of 17.82% and 393.36% at 40 °C. An Adaptive Neuro-fuzzy Inference System (ANFIS) model was devised to enhance predictive precision by meticulously optimising the number of membership functions (MFs) and input MF type. The ANFIS architecture that exhibited the most remarkable agreement with the experimental data for µ, λ, and σ was found to utilise the Product of Sigmas, Difference of Sigmas, and Generalized Bell MFs, respectively, with corresponding input MF numbers being 2–3, 3–2, and 3–2. The optimal ANFIS model for µ, λ, and σ exhibits a higher prediction accuracy with an R2 value of 0.99965, 0.99424 and 0.99995, respectively. The Figure of Merit analysis using Mouromtseff Number identified an optimal nanoparticle concentration range of 0.1–0.2 vol% for enhanced heat transfer performance with a reasonable µ increase. This range guides practitioners in utilising hybrid nanofluids effectively while managing potential drawbacks.

Collision Enhanced Raman Scattering (CERS): An Ultra-High Efficient Raman Enhancement Technique for Hollow Core Photonic Crystal Fiber Based Raman Spectroscopy Gas Analyzer.

Raman enhancement techniques are essential for gas analysis to increase the detection sensitivity of a Raman spectroscopy system. We have developed an efficient Raman enhancement technique called the collision-enhanced Raman scattering (CERS), where the active Raman gas as the analyte is mixed with a buffer gas inside the hollow-core photonic-crystal fiber (HCPCF) of a fiber-enhanced Raman spectroscopy (FERS) system. This results in an enhanced Raman signal from the analyte gas. In this study, we first showed that the intensity of the 587 cm-1 stimulated Raman scattering (SRS) peak of H2 confined in an HCPCF is enhanced by as much as five orders of magnitude by mixing with a buffer gas such as helium or N2. Secondly, we showed that the magnitudes of Raman enhancement depend on the type of buffer gas, with helium being more efficient compared to N2. This makes helium a favorable buffer gas for CERS. Thirdly, we applied CERS for Raman measurements of propene, a metabolically interesting volatile organic compound (VOC) with an association to lung cancer. CERS resulted in a substantial enhancement of propene Raman peaks. In conclusion, the CERS we developed is a simple and efficient Raman-enhancing mechanism for improving gas analysis. It has great potential for application in breath analysis for lung cancer detection.