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Background: Due to the strong association between the chemistry of medicinal plants and their biological properties, it is important to determine their phytochemical composition to justify experimental tests., Objective: The aim of this study was to evaluate the in vitro antioxidant and the enzyme inhibitory properties and to identify the bioactive compounds present in the extracts of Ephedra nebrodensis growing in Algeria., Methods: Total phenolic and flavonoids content in these extracts were quantified by Folin- Ciocalteu and aluminum chloride methods. The antioxidant capacity was assessed using DPPH, ABTS, β-carotene/linoleic acid, CUPRAC and FRAP assays, and in vitro cholinesterase activity against acetylcholinesterase and butyrylcholinesterase were evaluated. The chemical constituents of the extracts were analyzed by high-performance liquid chromatography coupled with mass spectrometric detection and gas chromatography. For the acute toxicity study, extracts were administered to mice at single dose of 2 g/kg and 5 g/kg by gavage., Results: Plant extracts were rich in phenolic compounds. Ethyl acetate extract presented the highest phenolic (238.44 ± 1.50 μg GAE /mg of extract) and flavonoid (21.12 ± 0.00 μg QE /mg of extract) contents. Likewise, ethyl acetate extract showed potent radical scavenging and reducing properties. Ethanol-acetone extract showed inhibitory activity against acetylcholinesterase, and was a potent inhibitor of butyrylcholinesterase. In all extracts, flavonoids were the most abundant compounds. The phytochemical investigation showed the presence of alkaloids (ephedrine and pseudo-ephedrine). In the acute toxicity, the LD 50 was superior to 5 g/kg body weight. There were no alterations in the histology of the liver and kidneys., Conclusion: This study demonstrated a good antioxidant potential and anticholinesterase activity of aerial parts of E. nebrodensis., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Objectives: Ephedra nebrodensis (Ephedraceae) presents a wide range of biological activities. It is used to treat respiratory problems and hepatic pathologies in traditional medicine. The aim of this study is to evaluate the antioxidant, in vitro and in vivo anti-inflammatory and analgesic properties of two hydro-alcoholic extracts of E. nebrodensis in mice., Materials and Methods: The antioxidant capacity of hydro-methanolic (HM) and hydro-ethanolic (HE) extracts of E. nebrodensis was evaluated via assays of their superoxide radical scavenging capacity and ferrous ion chelating activity. The in vitro anti-inflammatory activity of the extracts (5, 10, and 20 mg/kg) was also determined using the bovine serum albumin denaturation test. Croton oil-induced ear edema was then employed to evaluate the in vivo anti-inflammatory effect of the extracts (200 and 400 mg/kg). Finally, the analgesic activity of the extracts (200 and 400 mg/kg) was determined by the acetic acid-induced torsion test., Results: The hydro-alcoholic extracts of E. nebrodensis present significant antioxidant activity. The HE and HM could inhibit protein denaturation by 82.99%±20.21% and 56.25%±2.12%, respectively. The extracts (HM and HE) also show strong anti-inflammatory effects in vivo and could reduce ear edema by 70.37%±2.00% and 72.22%±1.94%, respectively. The HM extract (72.51%±2.43%) demonstrates greater pain inhibitory effects than HE (70.76%±2.58%)., Conclusion: The hydro-alcoholic extracts of E. nebrodensis produce antioxidant, anti-inflammatory, and analgesic effects. These results confirm the traditional use of the herb in the treatment of various diseases.

Ethnopharmacological Relevance: Erica arborea known as Khlenj in Algeria is a small shrub belonging to Ericaceae family. E. arborea Aqueous extract (EAAE) is used in traditional medicine for anti-inflammatory, diuretic, antimicrobial, and antiulcer purposes., Aim of the Study: To our knowledge, no data reveal the combination between in-vivo anti-inflammatory and toxicological studies of EAAE. For this purpose, the aim of this study is to evaluate the biological activity cited above and assess its safety., Material and Methods: Anti-inflammatory activity was undergone using carrageenan-induced paw edema and croton oil-induced ear edema. The acute and sub-acute toxicity were conducted following the OECD guidelines 423 and 407, respectively. Phytochemical identification was carried out using HPLC-DAD-MS. Quantitative evaluation of polyphenols; flavonoids and antioxidant activity of EAAE were also determined., Results: Oral administration of EAAE (250 and 500 mg/kg) significantly (p < 0.05) reduced the edema induced by carrageenan. Administration of EAAE dosed at 250 and 500 mg/kg exhibited efficacy in reducing edema induced by croton oil. The acute administration of EAAE at doses of 2000 and 5000 mg/kg did not cause any mortality or adverse effects indicating that the LD 50 is above 5000 mg/kg. The prolonged administration of EAAE (500 and 1000 mg/kg) showed a significant reduction in triglycerides levels in male and female rats whereas no significant changes in other biochemical and hematological parameters were observed. Histopathological damages were recorded in both liver and kidney animal's tissues of both sexes treated with medium and maximum doses of EAAE. Phytochemical characterization of EAAE revealed a high amount of phenolic compounds, HPLC-DAD-MS analysis led to the identification of chlorogenic acid and five flavonol glycosides: myricetin pentoside, quercetin-3-O-glucoside, myricetin-3-O-rhamnoside, quercetin-3-O-pentoside, and quercetin-3-O-rhamnoside., Conclusion: In the light of the results obtained in this study, EAAE corroborates the popular use to treat the anti-inflammatory impairments. EAAE can be considered as non-toxic in acute administration and exhibited a moderate toxicity in sub-acute administration. High phenolic content and in-vitro antioxidant activity observed indicate that EAAE may reduce oxidative stress markers in-vivo., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Background & Aims: Quantitative shear wave elastography was shown to be an effective tool for the non-invasive diagnosis and staging of chronic liver diseases. The liver shear modulus, estimated from the propagation velocity of shear waves, is correlated to the degree of fibrosis and can therefore be used for the non-invasive staging of fibrosis., Methods: We performed a clinical prospective study in a total of 120 patients with various chronic liver diseases to compare the accuracy of supersonic shear imaging (SSI), a technique based on acoustic radiation and ultrafast ultrasound imaging, to 1D transient elastography (FibroScan) for the staging and grading of fibrosis as assessed by liver biopsy. Since shear wave propagation spectroscopy can also provide additional mechanical information on soft tissues, such as viscosity, we also investigated those new mechanical parameters as possible predictors of fibrosis, steatosis, and disease activity., Results: SSI was successfully performed in 98.3% of patients and it was shown to be as accurate as FibroScan for the staging of fibrosis both for the whole population (N=120) and for the subgroup with viral hepatitis (n=70) (AUC=0.85 [0.77-0.96] and 0.89 [0.81-0.97] for significant fibrosis, AUC=0.90 [0.83-0.97] and 0.87 [0.75-0.98] for cirrhosis, with respect to SSI [n=68/70] and FibroScan [n=66/68]). Viscosity could also be used to stage the degree of fibrosis (AUC=0.76 [0.64-0.87] for significant fibrosis and AUC=0.87 [0.74-0.99] for cirrhosis), for the subgroup of patients with viral hepatitis (n=67/70) but was a poor predictor of disease activity and steatosis levels., Conclusions: Supersonic shear imaging is a robust technique for the staging of liver fibrosis. Liver viscosity was found to be correlated with fibrosis but not to steatosis or disease activity., (Copyright © 2014 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Understanding the extent of inflammation is crucial for early disease detection, monitoring disease progression, and evaluating treatment responses. Over the past decade, researchers have demonstrated the need to understand the extent of inflammation through qualitative or quantitative characterization of tissue viscoelasticity using different techniques. In this scientific review, an examination of research on the association between elasticity and Viscosity in diseases, particularly as tissue inflammation progresses, is conducted. A review of utilizing mechanical rheological models to characterize quantitative viscoelastic parameters of normal and inflamed tissues is also undertaken. Based on inclusion and exclusion criteria, we identified 14 full-text studies suitable for review out of 290 articles published from January 2000 to January 2024. We used PRISMA guidelines for the systematic review. In the review, three studies demonstrated the criterion used by the researchers in identifying the best rheological model. Eleven studies showed the clinical application of the rheological model in quantifying the viscoelastic properties of normal and pathological tissue. The review quantified viscoelastic parameters for normal and pathological tissue across various soft tissues. It evaluated the effectiveness of each viscoelastic property in distinguishing between normal and pathological tissue stiffness. Furthermore, the review outlined additional viscoelastic-related parameters for researchers to consider in future stiffness classification studies. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the diuretic effects of aqueous (AQ) and hydromethanolic crude extract (HM) the as well as the solvent fractions of the HM extract from Erica arborea flowers in mice. Methods: Mice were administered AQ and HM crude extracts, along with solvent fractions of HM extracts of E. arborea flowers, including HXF (n-hexane fraction), EAF (ethyl acetate fraction), and AQF (aqueous fraction), at doses ranging from 100 to 400 mg/kg orally. The effects of these extracts and solvent fractions on urine and salt excretion over 5 hours were compared to the effects of the solvent used for reconstitution and a standard drug (furosemide 10 mg/kg), as well as to each other. Results: The HM crude extract at a lower dose (100 mg/kg) significantly increased urine volume and salt excretion starting from the 3rd h compared to the AQ crude extract. Similar effects were observed for EAF. Notably, the HM extract and its EAF at 400 mg/kg showed comparable urine and salt excretion profiles to the standard drug. Conclusion: This study demonstrated that HM extract and EAF promote better diuresis, likely due to their saluretic properties. Furthermore, it confirms the diuretic activity of Erica arborea flowers. [ABSTRACT FROM AUTHOR]

Peripheral nerves are subjected to mechanical tension during limb movements and body postures. Nerve response to tensile stress can be assessed in vivo with shear-wave elastography (SWE). Greater tensile loads can lead to greater stiffness, which can be quantified using SWE. Therefore, this study aimed to conduct a systematic review and meta-analysis to perform an overview of the effect of joint movements on nerve mechanical properties in healthy nerves. The initial search (July 2023) yielded 501 records from six databases (PubMed, Embase, Scopus, Web of Science, Cochrane, and Science Direct). A total of 16 studies were included and assessed with a modified version of the Downs and Black checklist. Our results suggest an overall tendency for stiffness increase according to a pattern of neural tensioning. The main findings from the meta-analysis showed a significant increase in nerve stiffness for the median nerve with wrist extension (SMD [95%CI]: 3.16 [1.20, 5.12]), the ulnar nerve with elbow flexion (SMD [95%CI]: 2.91 [1.88, 3.95]), the sciatic nerve with ankle dorsiflexion (SMD [95%CI]: 1.13 [0.79, 1.47]), and the tibial nerve with both hip flexion (SMD [95%CI]: 2.14 [1.76, 2.51]) and ankle dorsiflexion (SMD [95%CI]: 1.52 [1.02, 2.02]). The effect of joint movement on nerve stiffness also depends on the nerve segment, the amount of movement of the joint mobilized, and the position of other joints comprised in the entirety of the nerve length. However, due to the limited number of studies, many aspects of nerve behavior together with the effect of using different ultrasound equipment or transducers for nerve stiffness evaluation still need to be fully investigated. [ABSTRACT FROM AUTHOR]

There are no ideal non-invasive tests for assessing the severity of liver fibrosis in people with metabolic dysfunction-associated steatotic liver disease (MASLD) and class 3 obesity, where body habitus often makes imaging technically challenging. This study aimed to assess the applicability and diagnostic performance of two-dimensional shear wave elastography (2D-SWE), alongside several serum-based liver fibrosis scoring methods, in individuals with class 3 obesity. A cross-sectional study was conducted in patients aged ≥18 years and with a body mass index (BMI) ≥ 40 kg/m2 who were participants in a publicly funded multidisciplinary weight management program in South Western Sydney. The 2D-SWE was performed using the ElastQ Imaging (EQI) procedure with the Phillips EPIQ Elite series ultrasound. An EQI Median value of ≥6.43 kPa was taken as a cutoff score for significant fibrosis, and the scan was considered valid when the liver EQI IQR/Med value was <30%. The Fibrosis-4 (FIB-4) index, AST-to-platelet ratio index (APRI), NAFLD fibrosis score (NFS), and circulating fibroblast activation protein index (FAP index) were calculated from fasting blood samples. The participants (n = 116; 67.2% female) were aged 47.2 ± 12.9 years, with BMI 54.5 ± 11.0 kg/m2. EQI Median values were obtained for 97.4% (113/116) of the 2D-SWE scans, and 91.4% (106/116) of the scans were considered valid. The EQI Median values exhibited a moderately positive correlation with the FIB-4 index (r = 0.438; p < 0.001) and a weakly positive correlation with the APRI (r = 0.388; p < 0.001), NFS (r = 0.210; p = 0.036) and FAP index (r = 0.226; p = 0.020). All liver fibrosis scores were positively correlated with one another. Among those referred for a liver biopsy based on the 2D-SWE and serum scores, half (11/22) underwent liver biopsy, and their 2D-SWE scores exhibited 72.7% accuracy (sensitivity: 71.4%; specificity: 75%) in detecting significant fibrosis. Our results show that 2D-SWE is a feasible, non-invasive test to assess liver fibrosis among people with class 3 obesity. Further research is needed to assess how 2D-SWE can be used alongside existing serum-based risk scores to reliably detect significant fibrosis, which would potentially reduce the need for invasive liver biopsy. [ABSTRACT FROM AUTHOR]

Purpose: This study was conducted to investigate the effectiveness of strain elastography in guiding precise and sufficient tissue sampling for perihilar cholangiocarcinoma (CCA) biopsies., Methods: Our retrospective analysis included 23 liver biopsies conducted between March 2019 and July 2022 for suspected perihilar CCA. An experienced radiologist performed the biopsies via an ultrasound machine with elastography configuration. Tissue stiffness color maps were used for guiding when the biopsies were performed. Strain index value calculations were made by radiologists on recorded images., Results: Patient demographics revealed a mean age of 65.17 ± 9.25 years, with a gender distribution of six females and 17 males. Gray-scale examinations unveiled diverse echogenic characteristics in liver lesions. Elastography-guided biopsies demonstrated no need for repeats, while gray-scale biopsies necessitated re-biopsy in four patients, resulting in cholangiocarcinoma diagnosis (P = 0.037). Strain index values showcased strong inter- and intra-observer agreements (P < 0.001). Notably, no post-biopsy complications emerged in either study group., Conclusion: The diagnostic advantage of elastography, particularly in enhancing accuracy in challenging isoechoic lesions, was demonstrated, although the substantial overlap between strain index values of benign and malignant liver masses limits clinical usefulness of this technique., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

A pre-clinical toxicological evaluation of herbal medicines is necessary to identify any underlying health-associated side effects, if any. BPGrit is an Ayurveda-based medicine prescribed for treating hypertensive conditions. High-performance liquid chromatography-based analysis revealed the presence of gallic acid, ellagic acid, coumarin, cinnamic acid, guggulsterone E, and guggulsterone Z in BPGrit. For sub-acute toxicity analysis of BPGrit, male and female Sprague-Dawley rats were given repeated oral gavage at 100, 300, and 1000 mg/kg body weight/day dosages for 28 days, followed by a 14-day recovery phase. No incidences of mortality, morbidity, or abnormal clinical signs were observed in BPGrit-treated rats throughout the study period. Also, the body weight and food consumption habits of the experimental animals did not change during the study duration. Hematological, biochemical, and histopathological analysis did not indicate any abnormal changes occurring in the BPGrit-treated rats up to the highest tested dose of 1000 mg/kg body weight/day. Finally, the study established the "no-observed-adverse-effect level" for BPGrit at >1000 mg/kg body weight/day in Sprague-Dawley rats., (© 2024 John Wiley & Sons Ltd.)

Background: Penthorum chinense Pursh (PCP) is widely utilized in China to treat a variety of liver diseases. It has been shown that flavonoids inhibit inflammation and have the potential to attenuate tissue damage and fibrosis. However, the mechanisms underlying how total flavonoids isolated from PCP (TFPCP) exert their anti-fibrotic effects remain unclear. Methods: The chemical composition of TFPCP was determined using UHPLC–QOrbitrap HRMS. Subsequently, rats were randomly assigned to a control group (Control), a carbon tetrachloride (CCl4)-induced hepatic fibrosis model group (Model), a positive control group [0.2 mg/(kg·day)] of Colchicine), and three TFPCP treatment groups [50, 100, and 150 mg/(kg·day)]. All substances were administered by gavage and treatments lasted for 9 weeks. Simultaneously, rats were intraperitoneally injected with 10%–20% CCl4 for 9 weeks to induce liver fibrosis. At the end of the experiment, the liver ultrasound, liver histomorphological, biochemical indicators, and inflammatory cytokine levels were tested respectively. The underlying mechanisms were assessed using Western blot, immunohistochemistry, immunofluorescence, RT-qPCR, and metabolomics. Results: Fourteen flavonoids were identified in TFPCP. Compared with control animals, CCl4-treated rats demonstrated obvious liver injury and fibrosis, manifested as increases in gray values, distal diameter of portal vein (DDPV) and a decrease in blood flow velocity (VPV) in the ultrasound analysis; increased biochemical index values (serum levels of ALT, AST, TBIL, and ALP); marked increases in the contents of fibrotic markers (PC III, COL4, LN, HA) and inflammatory factors (serum TNF-α, IL-6, and IL-1β); and significant pathological changes. However, compared with the Model group, the ultrasound parameters were significantly improved and the serum levels of inflammatory cytokines were reduced in the TFPCP group. In contrast, the expression of TGF-β1, TLR4, and MyD88, as well as the p-P65/P65 and p-IκBα/IκBα ratios, were considerably reduced following TFPCP treatment. In addition, we identified 32 metabolites exhibiting differential abundance in the Model group. Interestingly, TFPCP treatment resulted in the restoration of the levels of 20 of these metabolites. Conclusion: Our findings indicated that TFPCP can ameliorate hepatic fibrosis by improving liver function and morphology via the inactivation of the TLR4/MyD88- mediated NF-κB pathway and the regulation of liver metabolism. [ABSTRACT FROM AUTHOR]

Inflammation is the host response of immune cells during infection and traumatic tissue injury. An uncontrolled inflammatory response leads to inflammatory cascade, which in turn triggers a variety of diseases threatening human and animal health. The use of existing inflammatory therapeutic drugs is constrained by their high cost and susceptibility to systemic side effects, and therefore new therapeutic candidates for inflammatory diseases need to be urgently developed. Natural products are characterized by wide sources and rich pharmacological activities, which are valuable resources for the development of new drugs. This study aimed to uncover the alleviating effect and potential mechanism of natural product Limonium aureum (LAH) on LPS-induced inflammatory responses in macrophages. The experimental results showed that the optimized conditions for LAH ultrasound-assisted extraction via response surface methodology were an ethanol concentration of 72%, a material-to-solvent ratio of 1:37 g/mL, an extraction temperature of 73 °C, and an extraction power of 70 W, and the average extraction rate of LAH total flavonoids was 0.3776%. Then, data of 1666 components in LAH ethanol extracts were obtained through quasi-targeted metabolomics analysis. The ELISA showed that LAH significantly inhibited the production of pro-inflammatory cytokines while promoting the secretion of anti-inflammatory cytokines. Finally, combined with the results of network pharmacology analysis and protein expression validation of hub genes, it was speculated that LAH may alleviate LPS-induced inflammatory responses of macrophages through the AKT1/RELA/PTGS2 signaling pathway and the MAPK3/JUN signaling pathway. This study preliminarily revealed the anti-inflammatory activity of LAH and the molecular mechanism of its anti-inflammatory action, and provided a theoretical basis for the development of LAH as a new natural anti-inflammatory drug. [ABSTRACT FROM AUTHOR]

Aim: Shear wave (SW) elastography is used to evaluate metabolic dysfunction-associated steatotic liver disease (MASLD) pathophysiology. Increased elasticity due to fibrosis and increased viscosity due to necrosis and inflammation affect SW. Assessing fibrosis, the most prognostically relevant pathology, is critical. Viscosity is evaluated using the dispersion slope (DS); however, cut-off values that affect SW values are unclear. We compared the ultrasound imaging parameters (SW for viscoelasticity; DS for viscosity) with pathological findings., Methods: Patients (n = 159) who underwent liver biopsy and SW and DS assessments at our hospital were included. Fibrosis stage and inflammation grade cut-off values were calculated from SW, DS, and liver biopsy results using receiver operating characteristic curves. Cases in which liver biopsy results were inconsistent with SW results were used to determine the effect of viscosity on SW values. DS was examined in the Correct and Incorrect Diagnosis groups, which were categorized based on the concordance between SW and liver biopsy results. Dispersion slope cut-off values between the two groups were calculated., Results: Fibrosis stage cut-off values by SW (m/s) were: ≥F2, 1.62; ≥F3, 1.74; and F4, 1.97. Inflammation grade cut-off values by DS (m/s/kHz) were: ≥A1, 11.6; ≥A2, 14.5; and A3, 16.1. The Correct/Incorrect Diagnosis groups had 25/70 patients. The DS cut-off value for both groups was 13.2 m/s/kHz., Conclusions: Shear wave and DS are useful for evaluating liver fibrosis and inflammation in MASLD. For DS > 13.2 m/s/kHz, SW may be affected by the increased viscosity owing to inflammation. In such patients, caution should be used when determining/interpreting values., (© 2024 The Author(s). Hepatology Research published by John Wiley & Sons Australia, Ltd on behalf of Japan Society of Hepatology.)

The extracellular matrix (ECM) of natural cells typically exhibits dynamic mechanical properties (viscoelasticity and dynamic stiffness). The viscoelasticity and dynamic stiffness of the ECM play a crucial role in biological processes, such as tissue growth, development, physiology, and disease. Hydrogels with viscoelasticity and dynamic stiffness have recently been used to investigate the regulation of cell behavior and fate. This article first emphasizes the importance of tissue viscoelasticity and dynamic stiffness and provides an overview of characterization techniques at both macro- and microscale. Then, the viscoelastic hydrogels (crosslinked via ion bonding, hydrogen bonding, hydrophobic interactions, and supramolecular interactions) and dynamic stiffness hydrogels (softening, stiffening, and reversible stiffness) with different crosslinking strategies are summarized, along with the significant impact of viscoelasticity and dynamic stiffness on cell spreading, proliferation, migration, and differentiation in two-dimensional (2D) and three-dimensional (3D) cell cultures. Finally, the emerging trends in the development of dynamic mechanical hydrogels are discussed. [ABSTRACT FROM AUTHOR]

Introduction: The interaction between the heart and spleen plays a crucial role among cardiac and multiple organ networks, particularly in heart failure (HF). Ultrasound shear wave imaging is a non-invasive technology capable of quantifying tissue quality, but its significance in the spleen in patients with HF is poorly understood. Methods and results: This prospective observational study enrolled hospitalized 232 patients with HF undergoing abdominal ultrasonography. We used shear wave elastography (SWE) to assess spleen tissue elasticity and shear wave dispersion (SWD) to assess spleen tissue viscosity. Clinical, echocardiography, right heart catheterization, and outcome data were collected. Spleen SWE was negatively correlated with right ventricular fractional area change (R = − 0.180, P = 0.039), but not with right-sided pressure or congestion indices. When patients were divided into three groups based on tertile values of splenic parameters, Kaplan–Meier analysis demonstrated that patients with the highest spleen SWE and SWD had lower event-free survival rates from cardiac deaths and decompensated HF over a median 494-days follow-up period (P < 0.0001 and P < 0.0001, respectively). In a multivariable Cox proportional hazard model, both spleen SWE and SWD were independently associated with increased risks of adverse cardiac events (hazard ratio, 4.974 and 1.384; P = 0.003 and P < 0.0001). Mechanistically, we evaluated mRNA expressions of CD36, a monocyte/macrophage-associated molecule, in peripheral leukocytes, and found that enhanced spleen stiffness was associated with the upregulation of CD36 expressions. Conclusion: Share wave imaging of the spleen is useful for stratifying the prognosis of HF patients and may suggest a role of the cardio-splenic axis in HF pathogenies. [ABSTRACT FROM AUTHOR]

The development of new applications in ultrasound (US) imaging in recent years has strengthened the role of this imaging technique in the management of different pathologies, particularly in the setting of liver disease. Improved B-mode imaging (3D and 4D), contrast-enhanced US (CEUS) and especially US-based elastography techniques have created the concept of multiparametric ultrasound (MP-US), a term borrowed from radiological sectional imaging. Among the new elastography techniques, shear wave dispersion is a newly developed imaging technology which enables the assessment of the shear waves' dispersion slope. The analysis of the dispersion qualities of shear waves might be indirectly related to the tissue viscosity, thus providing biomechanical information concerning the pathologic state of the liver such as necroinflammation. Some of the most recent US devices have been embedded with software that evaluate the dispersion of shear waves/liver viscosity. In this review, the feasibility and the clinical applications of liver viscosity are reviewed based on the preliminary findings of both animal and human studies. [ABSTRACT FROM AUTHOR]

Background and aim: Diagnosing nonalcoholic steatohepatitis (NASH) is challenging. This study intended to explore the diagnostic value of multiple technical acoustic measurements in the diagnosis of NASH, and to establish a diagnostic model combining technical acoustic measurements with clinical parameters to improve the diagnostic efficacy of NASH. Methods: We consecutively enrolled 75 patients with clinically suspected nonalcoholic fatty liver disease (NAFLD) who underwent percutaneous liver biopsy in our hospital from June 2020 to December 2021. All cases underwent multiple advanced acoustic measurements for liver such as shear wave dispersion (SWD), shear wave speed (SWS), attenuation imaging (ATI), normalized local variance (NLV), and liver–kidney intensity ratio (Ratio) examination before liver biopsies. A nomogram prediction model combining the technical acoustic measurements and clinical parameters was established and the model is proposed to improve the diagnostic performance of NASH. Results: A total of 75 cases were included in this study. The classification of pathological grade for NASH was as follows: normal liver, (n = 15, 20%), nonalcoholic fatty liver (NAFL), (n = 44, 58.7%), and NASH, (n = 16, 21.3%). There were statistically significant differences in SWS (p = 0.002), acoustic coefficient (AC) (p = 0.018), NLV (p = 0.033), age (p = 0.013) and fasting blood glucose (Glu) (p = 0.049) between NASH and non-NASH. A nomogram model which includes SWS, AC, NLV, age and Glu was built to predict NASH, and the calibration curves showed good calibrations in both training and validation sets. The AUCs of the combined nomogram model for the training set and validation set were 0.8597 and 0.7794, respectively. Conclusion: There were statistically significant differences in SWS, AC, NLV, age and Glu between NASH and non-NASH. A nomogram model which includes SWS, AC, NLV, age and Glu was built to predict NASH. The predictive model has a higher diagnostic performance than a single factor model in the diagnosis of NASH and has good clinical application prospects. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To investigate the influencing factors of the image quality of shear wave elastography (SWE) performed using a high-frequency probe and its reproducibility for renal allografts. METHODS: A total of 211 patients with transplanted kidneys who underwent SWE examination performed using high-frequency or low-frequency probes were recruited for the study. The reproducibility of inter- and intraobserver agreements were analysed by using the intraclass correlation coefficient (ICC). According to the colour filling of the area of interest and imaging noise when conducting SWE, the image quality was classified as three grades: "good", "common", and "poor". A logistic regression was used to analyse the independent factors for SWE quality. RESULTS: In the comparative analysis, high frequency, transection measurement and middle pole were selected as the appropriate measurement methods. Regarding reproducibility, the ICCs) of the intra- and interobserver agreements were 0.85 and 0.77, respectively. Multivariate analysis indicated that only the skin allograft distance and kidney width were independent variables for SWE quality. In the subgroup analysis of the skin-allograft distance, the "good" and "common" rates of images decreased as the distance increased, but the CV (coefficients of variation) showed the opposite trend. The SWE quality of kidney width <5.4 cm was significantly better than that of kidney width ≥5.4 cm. CONCLUSIONS: High-frequency SWE can be used in the evaluation of transplanted kidneys due to its good repeatability and high successful measurement rate, but we should pay attention to the influence of the skin-allograft distance and kidney width on SWE quality. [ABSTRACT FROM AUTHOR]

The aim of the present study was to examine, for the first time, the phytochemical content of Ephedra alata pulp extract (EAP) and explore its antioxidant and anti-inflammatory capacities. High-performance liquid chromatography-electrospray ionization-quadrupole-time-of-flight mass spectrometry (HPLC–ESI–QTOF/MS) was used for phytochemical analysis and three in vitro antioxidant assays together with three in vitro anti-inflammatory tests were used for the assessment of biological activity. The HPLC–ESI–QTOF/MS analysis revealed the presence of 42 metabolites, including flavonoids, sphingolipides, fatty acids, ephedrine derivatives, and amino acid derivatives. In vitro findings revealed that EAP has interesting 2,2-diphenyl-1-picrylhydrazyl (DPPH), superoxide, and ferrous ion chelating capacities (IC50 values were 0.57 mg/mL, 0.55 mg/mL, and 0.51 mg/mL for DPPH, superoxide radical, and ferrous ion, respectively). Furthermore, EAP showed a noticeable anti-inflammatory ability by inhibiting the two cyclooxygenase isoforms, COX-1 and COX-2 (IC50 of 59.1 and 58.8 µg/mL for COX-1 and COX-2, respectively), preventing protein denaturation (IC50 = 0.51 mg/mL), and protecting membrane stabilization (IC50 = 0.53 mg/mL). The results highlighted the use of Ephedra alata pulp as a potential source of natural compounds with therapeutic effects for the management of inflammatory disorders. [ABSTRACT FROM AUTHOR]

Using liver phantoms for mimicking human tissue in clinical training, disease diagnosis, and treatment planning is a common practice. The fabrication material of the liver phantom should exhibit mechanical properties similar to those of the real liver organ in the human body. This tissue-equivalent material is essential for qualitative and quantitative investigation of the liver mechanisms in producing nutrients, excretion of waste metabolites, and tissue deformity at mechanical stimulus. This paper reviews the mechanical properties of human hepatic tissues to develop liver-mimicking phantoms. These properties include viscosity, elasticity, acoustic impedance, sound speed, and attenuation. The advantages and disadvantages of the most common fabrication materials for developing liver tissue-mimicking phantoms are also highlighted. Such phantoms will give a better insight into the real tissue damage during the disease progression and preservation for transplantation. The liver tissue-mimicking phantom will raise the quality assurance of patient diagnostic and treatment precision and offer a definitive clinical trial data collection., (© 2023. The Author(s).)

Purpose: To compare the diagnostic performance of T1 mapping and MR elastography (MRE) for staging of hepatic fibrosis and grading inflammation with histopathology as standard of reference. Methods: 68 patients with various liver diseases undergoing liver biopsy for suspected fibrosis or with an established diagnosis of cirrhosis prospectively underwent look-locker inversion recovery T1 mapping and MRE. T1 relaxation time and liver stiffness (LS) were measured by two readers. Hepatic fibrosis and inflammation were histopathologically staged according to a standardized fibrosis (F0–F4) and inflammation (A0–A2) score. For statistical analysis, independent t test, and Mann–Whitney U test and ROC analysis were performed, the latter to determine the performance of T1 mapping and MRE for fibrosis staging and inflammation grading, as compared to histopathology. Results: Histopathological analysis diagnosed 9 patients with F0 (13.2%), 21 with F1 (30.9%), 11 with F2 (16.2%), 10 with F3 (14.7%), and 17 with F4 (25.0%). Both T1 mapping and MRE showed significantly higher values for patients with significant fibrosis (F0-1 vs. F2-4; T1 mapping p < 0.0001, MRE p < 0.0001) as well as for patients with severe fibrosis or cirrhosis (F0-2 vs. F3-4; T1 mapping p < 0.0001, MRE p < 0.0001). T1 values and MRE LS were significantly higher in patients with inflammation (A0 vs. A1-2, both p = 0.01). T1 mapping showed a tendency toward lower diagnostic performance without statistical significance for significant fibrosis (F2-4) (AUC 0.79 vs. 0.91, p = 0.06) and with a significant difference compared to MRE for severe fibrosis (F3-4) (AUC 0.79 vs. 0.94, p = 0.03). For both T1 mapping and MRE, diagnostic performance for diagnosing hepatic inflammation (A1-2) was low (AUC 0.72 vs. 0.71, respectively). Conclusion: T1 mapping is able to diagnose hepatic fibrosis, however, with a tendency toward lower diagnostic performance compared to MRE and thus may be used as an alternative to MRE for diagnosing hepatic fibrosis, whenever MRE is not available or likely to fail due to intrinsic factors of the patient. Both T1 mapping and MRE are probably not sufficient as standalone methods to diagnose hepatic inflammation with relatively low diagnostic accuracy. [ABSTRACT FROM AUTHOR]

Viscosity and elasticity represent biomechanical properties of soft tissues that suffer changes during the pathophysiological alterations of the tissue in various conditions. This study aimed to determine average viscosity values for the thyroid gland and to evaluate the potential influences of age, gender and body mass index (BMI), using a recent technique Viscosity Plane-wave UltraSound (Vi PLUS). A total of 85 healthy Caucasian volunteers (56 women and 29 men, median age of 29 years, range 17–81 years) were included in this prospective monocentric study conducted between January 2022 and March 2022. Thyroid viscosity was measured using the SuperSonic MACH 30® Ultrasound system (Aixplorer, SuperSonic Imagine, Aix-en-Provence, France), equipped with a curvilinear C6-IX transducer that allows simultaneous quantification of the viscosity and stiffness. The mean thyroid viscosity measurement value was 2.63 ± 0.47 Pa.s. No statistically significant differences were detected between the left and the right lobes of the thyroid gland. A significant positive correlation was found between thyroid viscosity and elasticity (r = 0.685, p < 0.0001). There was no statistically significant correlation between body mass index (BMI) and thyroid gland viscosity and elasticity values (r = 0.215, p = 0.053; r = 0.106, p = 0.333). No correlation between viscosity and gender was established (p > 0.05). Vi PLUS represents a new and promising ultrasonographic technique that can provide helpful information for evaluating the thyroid parenchyma, similar to elastography. The effect of the potential confounding factors on thyroid viscosity was negligible, except for BMI. [ABSTRACT FROM AUTHOR]

Objective. This systematic review and meta-analysis aimed to compare the diagnostic performance of transient elastography (TE) and two-dimensional shear wave elastography (2D-SWE) for staging liver fibrosis in patients with chronic viral hepatitis (CVH). Methods. Pubmed, Embase, Web of Science, and Cochrane Library were searched (-01/08/2021) for studies comparing TE with 2D-SWE in patients with CVH. Other etiologies of chronic liver disease (CLD) and articles not published in SCI journals were excluded. The bivariate random-effects model was used to pool the performance of the TE and 2D-SWE. Results. Eight articles with a total of 1301 CVH patients were included. The prevalence of significant fibrosis (fibrosis stage ≥ 2), advanced fibrosis (fibrosis stage ≥ 3), and cirrhosis was 50.8%, 44.8%, and 34.7%, respectively. 2D-SWE expressed higher overall accuracy than TE in detecting significant fibrosis (0.93 vs. 0.85, P = 0.04). No significant difference among the overall diagnostic accuracy of TE and 2D-SWE in staging advanced fibrosis and cirrhosis was found. Conclusion. TE and 2D-SWE express good to excellent diagnostic accuracies to stage fibrosis in CVH patients. 2D-SWE compares favorably with TE especially for predicting significant fibrosis. [ABSTRACT FROM AUTHOR]

Shear-wave elastography (SWE) is widely used in thyroid evaluation, but multiple factors influence thyroid stiffness. Estimating tissue viscosity may enhance the ultrasound diagnosis of thyroid diseases, along with the ultrasound (US) and the SWE assessment. In order to be able to detect diffuse thyroid disease by viscosity measurements, it is essential to firstly define the normal values of thyroid viscosity in healthy subjects. Currently there are no published data on thyroid viscosity measurements. This first prospective study aimed to determine the normal range of thyroid viscosity values in a cohort of healthy thyroids, as well as to determine the factors that may influence them. One hundred and twenty-one consecutive subjects without thyroid pathology were evaluated in the study by means of conventional ultrasound, two-dimensional SWE (2D SWE PLUS) and viscosity plane-wave ultrasound (ViPLUS) embedded in the Supersonic MACH® 30 ultrasound system. Five valid tissue viscosity measurements were obtained for each thyroid lobe in every patient and the median values were analyzed and correlated with the biological and demographic parameters of each patient. Our results reveal that ViPLUS is a highly feasible and reproducible technique for thyroid evaluation. Thyroid stiffness, age, gender, BMI and depth of measurements did not influence the thyroid viscosity values. The mean thyroid viscosity by ViPLUS for normal thyroid tissue was of 2.42 ± 0.41 Pa·s. Viscosity assessment by Supersonic ViPLUS is an innovative, non-invasive technique that has proven to be useful for thyroid US evaluation and remains to demonstrate its effectiveness in identifying patients with thyroid disease. [ABSTRACT FROM AUTHOR]

Cutibacterium acnes (C. acnes) is the main causative agent of acne vulgaris. The study aims to evaluate the antimicrobial activity of a natural product, Arctostaphylos uva-ursi leaf extract, against C. acnes. Preliminary chemical–physical characterization of the extract was carried out by means of FT-IR, TGA and XPS analyses. Skin permeation kinetics of the extract conveyed by a toning lotion was studied in vitro by Franz diffusion cell, monitoring the permeated arbutin (as the target component of the extract) and the total phenols by HPLC and UV-visible spectrophotometry, respectively. Antimicrobial activity and time-killing assays were performed to evaluate the effects of Arctostaphylos uva-ursi leaf extract against planktonic C. acnes. The influence of different Arctostaphylos uva-ursi leaf extract concentrations on the biofilm biomass inhibition and degradation was evaluated by the crystal violet (CV) method. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) test was used to determine the viability of immortalized human keratinocytes (HaCaT) after exposure to Arctostaphylos uva-ursi leaf extract for 24 and 48 h. Levels of interleukin (IL)-1β, IL-6, IL-8 and tumour necrosis factor (TNF)-α were quantified after HaCaT cells cotreatment with Arctostaphylos uva-ursi leaf extract and heat-killed C. acnes. The minimum inhibitory concentration (MIC) which exerted a bacteriostatic action on 90% of planktonic C. acnes (MIC90) was 0.6 mg/mL. Furthermore, MIC and sub-MIC concentrations influenced the biofilm formation phases, recording a percentage of inhibition that exceeded 50 and 40% at 0.6 and 0.3 mg/mL. Arctostaphylos uva-ursi leaf extract disrupted biofilm biomass of 57 and 45% at the same concentrations mentioned above. Active Arctostaphylos uva-ursi leaf extract doses did not affect the viability of HaCaT cells. On the other hand, at 1.25 and 0.6 mg/mL, complete inhibition of the secretion of pro-inflammatory cytokines was recorded. Taken together, these results indicate that Arctostaphylos uva-ursi leaf extract could represent a natural product to counter the virulence of C. acnes, representing a new alternative therapeutic option for the treatment of acne vulgaris. [ABSTRACT FROM AUTHOR]

Elastography is a useful noninvasive tool for the assessment of renal transplant recipients. 2D-shear wave elastography (SWE) PLUS and viscosity plane-wave ultrasound (Vi PLUS) have emerged as novel techniques that promise to offer improved renal stiffness and viscosity measures due to improved processing algorithms. Methods: We performed a cross-sectional study of 50 kidney transplanted patients (16 women, 34 men; mean age of 47.5 ± 12.5; mean estimated glomerular filtration rate (eGFR) estimated by Chronic Kidney Disease Epidemiology Collaboration formula: 52.19 ± 22.6 mL/min/1.73 m2; and a mean duration after transplant of 10.09 ± 5 years). For every patient, we obtained five valid measurements of renal stiffness (obtained from five different frames in the cortex of the renal graft), and also tissue viscosity, with a C6-1X convex transducer using the Ultra-Fast™ software available on the Aixplorer Mach 30 ultrasound system (Supersonic Imagine, Aix-en-Provence, France). The median values of elastographic and viscosity measures have been correlated with the patients' demographic, biological, and clinical parameters. Results: We obtained a cut-off value of renal cortical stiffness of <27.3 kiloPascal(kPa) for detection of eGFR < 60 mL/min/1.73 m2 with 80% sensitivity and 85% specificity (AUC = 0.811, p < 0.0001), a cut-off value of <26.9 kPa for detection of eGFR < 45 mL/min/1.73 m2 with 82.6% sensitivity and 74% specificity (AUC = 0.789, p < 0.0001), and a cut-off value of <23 kPa for detection of eGFR < 30 mL/min/1.73 m2 with 88.8% sensitivity and 75.6% specificity (AUC = 0.852, p < 0.0001). We found a positive correlation coefficient between eGFR and the median measure of renal cortical stiffness (r = 0.5699, p < 0.0001), between eGFR the median measure of viscosity (r = 0.3335, p = 0.0180), between median depth of measures and renal cortical stiffness (r = −0.2795, p = 0.0493), and between median depth of measures and body mass index (BMI) (r = 0.6574, p < 0.0001). Our study showed good intra-operator agreement for both 2D SWE PLUS measures—with an intraclass correlation coefficient (ICC) of 0.9548 and a 95% CI of 0.9315 to 0.9719—and Vi PLUS, with an ICC of 0.8323 and a 95% CI of 0.7457 to 0.8959. The multivariate regression model showed that 2D SWE PLUS values were associated with eGFR, Vi PLUS, and depth of measures. Conclusions: Assessment of renal allograft stiffness and viscosity may prove to be an effective method for identifying patients with chronic allograft injury and could prove to be a low-cost approach to provide additional diagnostic information of kidney transplanted patients. [ABSTRACT FROM AUTHOR]

Objective: To observe the feasibility of shear wave elastography (SWE) in the diagnosis of peripheral neuropathy in patients undergoing hemodialysis [chronic kidney disease stage 5 dialysis (CKD5D)]. Methods: Forty patients with CKD5D were divided into a uremic peripheral neuropathy (UPN) group (n = 25) and a non-UPN group (n = 15) according to the results of a neuro-electrophysiological examination. Sixteen healthy control subjects were also enrolled in this study. Two-dimensional ultrasound examination was conducted, and SWE was then performed to measure Young's modulus of the tibial nerve. The left and right diameters (D1), anterior and posterior diameters (D2), perimeter (C), cross-sectional area (CSA), and Young's modulus (E) were measured three times at the same non-entrapment site. The average values were recorded and calculated. The following evaluation indices were also analyzed: sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and area under the receiver operating characteristic curve (AUC). Results: D1, D2, C, and CSA were not significantly different among the three groups (P > 0.05). However, the difference in the E value among the three groups was statistically significant (P < 0.05). The AUC was 0.889 based on the E value. Using a tibial nerve E value of 48.35 kPa as the cutoff value, the sensitivity, specificity, PPV, and NPV were 86.0%, 84.0%, 81.1%, and 88.1%, respectively. Conclusions: SWE is useful for the diagnosis of peripheral neuropathy in patients with CKD5D. Young's modulus of 48.35 kPa for the tibial nerve is the optimal cutoff value and has the best diagnostic efficiency for peripheral neuropathy in CKD5D patients. [ABSTRACT FROM AUTHOR]

Liver fibrosis is the most significant prognostic factor in chronic liver disease (CLD). Clinical practice guidelines recommend the use of non-invasive techniques, such as two-dimensional shear-wave elastography (2D-SWE), to assess liver stiffness as a marker of fibrosis. Several other factors influence liver stiffness in addition to liver fibrosis. It is presumed that changes due to necro-inflammation modify the propagation of shear waves (dispersion). Therefore, new imaging techniques that investigate the dispersion properties of shear waves have been developed, which can serve as an indirect method of measuring liver viscosity (Vi PLUS). Defining the reference values in healthy subjects among different age groups and genders and analyzing the factors that influence these values is essential. However, published data on liver viscosity are still limited. This is the first study that aimed to assess the normal range of liver viscosity values in subjects with healthy livers and analyze the factors that influence them. One hundred and thirty-one consecutive subjects with healthy livers were enrolled in this prospective study. The results showed that Vi PLUS is a highly feasible method. Liver stiffness, age and BMI influenced the liver viscosity values. The mean liver viscosity by Vi PLUS in subjects with healthy livers was 1.59 Pa·s. [ABSTRACT FROM AUTHOR]

Chronic liver diseases, resulting from chronic injuries of various causes, lead to cirrhosis with life-threatening complications including liver failure, portal hypertension, hepatocellular carcinoma. A key unmet medical need is robust non-invasive biomarkers to predict patient outcome, stratify patients for risk of disease progression and monitor response to emerging therapies. Quantitative imaging biomarkers have already been developed, for instance, liver elastography for staging fibrosis or proton density fat fraction on magnetic resonance imaging for liver steatosis. Yet, major improvements, in the field of image acquisition and analysis, are still required to be able to accurately characterize the liver parenchyma, monitor its changes and predict any pejorative evolution across disease progression. Artificial intelligence has the potential to augment the exploitation of massive multi-parametric data to extract valuable information and achieve precision medicine. Machine learning algorithms have been developed to assess non-invasively certain histological characteristics of chronic liver diseases, including fibrosis and steatosis. Although still at an early stage of development, artificial intelligence-based imaging biomarkers provide novel opportunities to predict the risk of progression from early-stage chronic liver diseases toward cirrhosis-related complications, with the ultimate perspective of precision medicine. This review provides an overview of emerging quantitative imaging techniques and the application of artificial intelligence for biomarker discovery in chronic liver disease. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the feasibility of multiple ultrasound markers for the non-invasive characterization of fibrosis, inflammation and steatosis in the liver in pediatric patients. Materials and methods: The quantitative ultrasound measures shear wave elastography (SWE), shear wave dispersion (SWD) and attenuation imaging (ATI) were compared and correlated with percutaneous liver biopsies and corresponding measures in a control cohort. Results: The median age of the 32 patients was 12.1 years (range 0.1–17.9), and that of the 15 controls was 11.8 years (range: 2.6–16.6). Results: There was a significant difference in SWE values between histologic grades of fibrosis (p = 0.003), with a positive correlation according to the grade (r = 0.7; p < 0.0001). Overall, a difference in SWD values between grades of inflammation was found (p = 0.009) but with a lack of correlation (r = 0.1; p = 0.67). Comparing inflammation grades 0–1 (median:13.6 m/s kHz [min; max; 8.4; 17.5]) versus grades 2–3 (16.3 m/s kHz [14.6; 24.2]) showed significant differences between the groups (p = 0.003). In the 30 individuals with a steatosis score of 0, ATI was measured in 23 cases with a median value of 0.56 dB/cm/MHz. Conclusion: Comprehensive ultrasound analysis was feasible to apply in children and has the potential to reflect the various components of liver affection non-invasively. Larger studies are necessary to conclude to what extent these image-based markers can classify the grade of fibrosis, inflammation and steatosis. [ABSTRACT FROM AUTHOR]

Hepatic steatosis is associated with various liver diseases. The main pathological feature of steatosis is the excessive lipid accumulation. Ultrasound has been extensively used for the diagnosis of hepatic steatosis. However, most ultrasound-based non-invasive methods are still not accurate enough for cases with light lipid infiltration. One important reason is that the extent to which lipid infiltration may affect mechanical properties of hepatocytes remains unknown. In this work, we used atomic force microscope and in vitro dose-dependent lipid deposition model to detect the quantitative changes of mechanical properties under different degrees of steatosis in a single-cell level. The results show that hepatic cells with lipid deposition can be treated as linear viscoelastic materials with the power law creep compliance and relaxation modulus. Further analysis showed that even slight accumulation of lipid can lead to measurable decrease of stiffness and increased fluidity in liver cells. The accurate detection of viscoelastic properties of hepatocytes and the analysis methods may provide novel insights into hepatic steatosis grading, especially in the very early stage with reversible liver lesion. The application of viscoelasticity index for grading fat deposition might be a new detection indicator in future clinical diagnosis. [ABSTRACT FROM AUTHOR]

Background: Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming one of the most common liver diseases. Ultrasound elastography has been used for the diagnosis of NAFLD. However, clinical research on steatosis by elastography technology has mainly focused on steatosis with fibrosis or non-alcoholic steatohepatitis (NASH), while steatosis without fibrosis has been poorly studied. Moreover, the relationship between liver viscoelasticity and steatosis grade is not clear. In this study, we evaluated the degree of liver steatosis in a simple steatosis rat model using shear wave elastography (SWE).Results: The viscoelasticity values of 69 rats with hepatic steatosis were measured quantitatively by SWE in vivo and validated by a dynamic mechanical analysis (DMA) test. Pathological sections were used to determine the steatosis grade for each rat. The results showed that the elasticity values µ obtained by the two methods followed the same trend, and µ is significantly correlated with liver steatosis. The Pearson's correlation coefficients indicate that [Formula: see text] obtained by SWE is positively linear correlated with DMA (r = 0.628, p = 7.85 × 10-9). However, the viscosity values [Formula: see text] obtained by SWE were relatively independent of those obtained by DMA with a correlation coefficient of - 0.01. The combined Voigt elasticity measurements have high validity in the prediction of steatosis (S0 vs. S1-S4), with an AUROC of 0.755 (95% CI 0.6175-0.8925, p < 0.01) and the optimal cutoff value was 2.08 kPa with a sensitivity of 78% and specificity of 63%.Conclusion: SWE might have the feasibility to be introduced as an auxiliary technique for NAFLD patients in clinical settings. However, the viscosity results measured by SWE and DMA are significantly different, because the two methods work in different frequency bands. [ABSTRACT FROM AUTHOR]

Elastography provides significant information on staging of fibrosis in patients with liver disease and may be of some value in assessing steatosis. However, there remain questions as to the role of steatosis and fibrosis as cofactors influencing the viscoelastic measurements of liver tissues, particularly shear wave speed (SWS) and shear wave attenuation (SWA). In this study, by employing the theory of composite elastic media as well as two independent experimental measurements on oil-in-gelatin phantoms and also finite element simulations, it is consistently shown that fat and fibrosis jointly influence the SWS and SWA measurements. At a constant level of fat, fibrosis stages can influence the SWA by factors of 2–4. Moreover, the rate of increase in SWA with increasing fat is strongly influenced by the stages of fibrosis; softer background cases (low fibrosis stages) have higher rate of SWA increase with fat than those with stiffer moduli (higher fibrosis stages). Meanwhile, SWS results are influenced by the presence of fat, however the degree of variability is more subtle. The results indicate the importance of jointly considering fat and fibrosis as contributors to SWS and SWA measurements in complex liver tissues and in the design and interpretation of clinical trials. [ABSTRACT FROM AUTHOR]

The stiffness of the cellular environment controls malignant cell phenotype and proliferation. However, the effect of viscous dissipation on these parameters has not yet been investigated, in part due to the lack of in vitro cell substrates reproducing the mechanical properties of normal tissues and tumors. In this article, we use a newly reported viscoelastic polyacrylamide gel cell substrate, and we characterize the impact of viscous dissipation on three malignant cell lines: DU145 and PC3 derived from prostate and LN229 from brain. The spreading, motility and proliferation rates of these cells were analyzed on 1 kPa and 5 kPa elastic and viscoelastic gels. Surprisingly, the effect of substrate viscous dissipation on cell behavior depended on substrate stiffness for the three cell types tested. We conclude that viscoelasticity controls the spreading, proliferation and migration of malignant cells in vitro. These results highlight the critical role of viscous dissipation in the phenotype and proliferation of malignant cells, especially in stiff tumor environments. [ABSTRACT FROM AUTHOR]

Methods of electrostatic conversion are available for harvesting energy where there are ambient vibrations. However, most of the previous work in the literature has addressed applications with high frequencies. In this study, we are not only implementing an electret-based energy harvester for low-frequency applications but also evaluating the effect of parameters, including vibration rates, accelerations, electret surface potential, e.g. on the efficiency of electrostatic energy harvesting (EH). A prototype system, with the size of 4 × 28 cm3, was built and constructed to accomplish experimental analysis, and the corona triode process was used to prepare electrets by charging Teflon FEP films. In the electret surface potential range of 300–1800 V, vibration frequency range of 2–45 Hz, and acceleration range of 0.1–1.0 g, the effect of parameters on the EH efficiency was experimentally tested. To predict and maximize the performance of the system, a mathematical response surface model (RSM), validated experimentally < 9.5% error. The maximum peak-peak voltage output of 318 V was predicted using this model for the electret surface potential of −1800 V, and vibration frequency of 16 Hz. Moreover, harvested energy was ∼ 900 μJ (∼0.8 µJ per mechanical cycle) in a minute though low frequencies (<20 Hz), which can be easily enhanced to more than 1 mJ with system optimization. We suggest our device can be used in numerous low-frequency applications, and our predictive model can also be used to optimize the efficiency of other electrostatic energy harvesters based on electrets. [ABSTRACT FROM AUTHOR]

The dielectric relaxation and alternating-current (AC) conductivity behavior of poly(ethylene-2,6-naphthalenedicarboxylate) are found to be sensitive to its degree of crystallinity. It has been shown that increasing the temperature at low frequency leads to three relaxation phenomena due to different molecular motions: the β, β*, and α relaxation. The effects of the chemical and morphological structure of the material on the dielectric properties were also considered. AC conductivity measurements were performed and studied according to the "universal" Jonscher power law. This universal law allows satisfactory determination of the parameters A and n, which seem to be correlated via a mathematical relationship, reaching an optimum due to the β relaxation of the chain branching. [ABSTRACT FROM AUTHOR]

The time-dependent properties of rubber-like synthesized and biological materials are crucial for their applications. Currently, this behavior is mainly measured using axial tensile test, compression test, or indentation. Limited studies performed on using multi-axial loading measurements of time-dependent material behavior exist in the literature. Therefore, the aim of this study is to investigate the viscoelastic response of rubber-like materials under multi-axial loading using cavity expansion and relaxation tests. The tests were performed on PVA hydrogel specimens. Three hyperelasitc models and one term Prony series were used to characterize the viscoelastic response of the hydrogels. Finite element (FE) simulations were performed to verify the validity of the calibrated material coefficients by reproducing the experimental results. The excellent agreement between the experimental, analytical and numerical data proves the capability of the cavity expansion technique to measure the time-dependent behavior of viscoelastic materials. [ABSTRACT FROM AUTHOR]