Shear Wave Research Articles

Ambient seismic noise imaging of a tailings dam internal structure

Several tailings dam failures have been reported over the past few decades, raising questions about the stability of these structures. Over the past 30 years, there have been more severe failures of tailings dams, which have resulted in damage to the environment, fatalities and severe socio-economic issues. It is often impossible to predict when tailings dams could fail, so there is an urgent need to develop cost-effective methods for monitoring their stability and preventing such catastrophic events. Recent advancements in techniques related to ambient seismic noise have the potential to introduce new approaches to subsurface imaging and monitoring. In this study, we investigated the potential of using ambient seismic noise to monitor the interior wall of a tailings dam. We used 20 3C short-period geophones to record ambient noise over 3 days continuously. We set up the geophones at the Harmony Gold Mine tailings dam in Welkom, South Africa, along a survey profile approximately 100 m long. Seismic interferometry was used from the recorded data to retrieve empirical Green’s functions. We computed the dispersion curves’ inversion to determine the dam wall’s shear wave velocity at different depths. The calculated shear wave velocity cross-sections revealed a region of reduced velocity within the dam wall, situated between 2 m and 10 m beneath the surface. This zone of low velocity can be a sign of water-saturated material or other subsurface anomalies, which might jeopardise the dam’s structure.

Diagnostic value of mammography combined with ultrasound shear wave elastography and magnetic resonance imaging in breast cancer

Diagnostic value of mammography combined with ultrasound shear wave elastography and magnetic resonance imaging in breast cancer

Effect of soil profile-related parameters on seismic performance of ductile reinforced concrete building frames in California

Strong ground motions with specific site characteristics can lead to structural damage. Comprehending the effects of site characteristics on the dynamic response of structures is crucial for evaluating seismic performance and thereby implementing design that can mitigate potential damage. This study explores how the site characteristics, including the average shear wave velocity, soil depth to rock, and site period, influence the seismic response of reinforced concrete buildings. Soil column models were created using 319 soil profiles located in California and were employed to perform the nonlinear site response analysis of 80 rock motions to generate surface motions. Subsequently, low-to high-rise reinforced concrete moment-resisting frames with four, eight, twelve, and twenty stories that are representative of California were modeled to conduct nonlinear structural analyses. In this process, the influence of the three site characteristics on the response of the surface motions and structures was investigated. This investigation revealed that structural responses tend to increase when the average shear wave velocity ranges from 180 to 360 m/s or when the depth exceeds 135 m. Additionally, structures with a natural period exceeding 1 s were found to be more vulnerable as the number of stories increased. The outcomes will promote the development of seismic design methods based on different site characteristics.

Research on thermal resistance Performance: Broadband solar absorber based on laminated circular ring − disk microstructure

This paper presents a laminated circular-ring-disk (CRDS) solar microstructure absorber constructed based on heat-resistant metals. This absorber achieves an ultra-broadband absorption with a bandwidth of 2171.68 nm in the near-ultraviolet to mid-infrared band, and has three absorption peaks with absorption rates exceeding 96 %, with peak wavelengths of 342.09 nm, 1215.40 nm, and 2032.86 nm respectively. With the finite-difference time-domain method (FDTD), we detected that the average absorption efficiency of this absorber under Atmospheric mass of 1.5(AM 1.5) conditions is as high as 96.05 %, and the average energy loss is only 3.95 %. Meanwhile, the research results of the electric field distribution of the CRDS microstructure show that CRDS effectively promotes the surface plasmon resonance effect between the laminated metal materials. Combined with the research on the top micro-absorption structure materials, we finally determined the structural parameters of the CRDS structure absorber and selected heat-resistant metals nickel (Ni), chromium (Cr), and titanium (Ti). On this basis,we focused on the thermal radiation performance of the absorber and found that it has good adaptability to high-temperature environments. Finally, by comparing the Transverse Electric Wave(TE) and Transverse Magnetic Wave(TM) polarization conditions with the sweep parameter diagrams of 0°-60°, we found that the absorber has excellent angle insensitivity. In view of the above discussions, the CRDS microstructure absorber has good thermal stability, angle insensitivity, and can achieve ultra-broadband perfect absorption from the near-ultraviolet to the mid-infrared band, and has broad application prospects.

VSP Modeling With The Reflectivity Method And Semblance Processing

The present work deals with a specific detail of the VSP technique for estimating local compressional, 𝑣𝑃, and shear, 𝑣𝑆 , wave velocities focused on reservoir characterization and seismic interpretation in sedimentary basins. This investigation was based on the presence of fluids (water, oil, gas) in porous rocks and its relationship with the 𝛾 = 𝑣𝑆 𝑣𝑃 ratio, which mainly affects the shear wave velocity. The forward modeling was based on the reflectivity method to simulate seismic sections along depth in the borehole, considering the presence of a reservoir formation with an anomalous 𝛾 ratio value. The seismic processing of the vertical, transversal, and radial components produced by VSP modeling was based on band-pass filtering for upward and downward field separation, semblance picking, and NMO correction for estimating 𝑣𝑃 and 𝑣𝑆 wave velocities. Additionally, we compare different semblance measures to validate the NMO correction. The results show an accurate estimate of the 𝛾 ratio in the target layer, even considering receivers at different depths and high noise levels in the VSP sections. Besides that, the 2D numerical experiment reveals information about the sensitivity of the 𝛾 parameter in a layered medium with velocity variation, principally around regions with the potential presence of oil and gas.

Novel method to estimate horizontal variability of shear wave velocity through multichannel analysis of surface waves

Scale of fluctuations (SOFs) of spatially variable soil properties have been regarded as one of the important parameters for performing reliability-based design in geotechnical engineering. However, the information required to estimate the SOFs in practice is limited, especially in the horizontal direction. In this study, the potential use of Multichannel Analysis of Surface Waves (MASW) to estimate the SOFs of shear wave velocity (VS) in horizontal direction is investigated through a series of numerical investigations. 2D random field models with a vertically increasing trend of VS were first simulated with different levels of variability controlled by the coefficient of variation (COV) and SOF. Afterwards, a large number of numerical MASW tests were performed using a 2D finite difference method, where the survey lines were progressively shifted. Results show that the COV of VS can be determined from the scatter of the dispersion curves, whereas the horizontal SOF of VS can be appropriately estimated from the phase velocity profile presented in the wavelength form. Additionally, in-situ MASW tests were conducted to estimate the horizontal SOF, and the obtained results align with those estimated by different methods. It is highlighted that the accuracy of the estimation depends on survey length. The interpretation using a long array reflects an averaged site condition of the survey area, thus losing the variability information. Favorable predictions are produced when survey length is shorter than 1.0 SOF. However, it should be noted that use of short survey length may limit the depth of investigation.

Clinical predictors and noninvasive imaging in Fontan-associated liver disease: A systematic review and meta-analysis

Background: Despite the development of several imaging modalities for diagnosing Fontan-associated liver disease (FALD), there is no optimal protocol for the follow-up of FALD. We conducted a systematic review and meta-analysis to identify factors related to liver fibrosis using biopsy reports and to identify alternative noninvasive modalities that could better reflect liver histological changes in FALD. Methods: A systematic review and meta-analysis were conducted following the PRISMA guidelines Table S2. We searched Embase, PubMed, and Cochrane databases for studies on FALD, focusing on those assessing clinical factors associated with liver fibrosis severity through liver biopsy and noninvasive imaging techniques. Results: A total of 42 studies were identified, of which 12 conducted meta-analyses and subgroup analyses of the severity of liver fibrosis using liver biopsies. Liver biopsy results showed a weak positive correlation between Fontan duration and fibrosis severity (R = 0.36). Subgroup analyses revealed significant differences in hemodynamic parameters, such as Fontan pressure, between patients with mild and severe fibrosis. Platelet count, aspartate aminotransferase to platelet ratio index, and fibrosis-4 index were significantly associated with fibrosis severity, with severe fibrosis showing lower platelet counts and higher aspartate aminotransferase to platelet ratio index and fibrosis-4 index levels. Noninvasive imaging modalities, particularly magnetic resonance elastography and shear wave elastography, demonstrated strong correlations with biopsy-confirmed fibrosis severity. Conclusions: This study identifies key clinical factors, and noninvasive modalities accurately reflect liver fibrosis severity in patients with FALD. Clinical factors such as platelet count, aspartate aminotransferase to platelet ratio index, and fibrosis-4 index may aid in identifying patients at risk for severe fibrosis. In addition, magnetic resonance elastography and shear wave elastography are promising tools for noninvasive assessment in our study. Further research is needed to refine these diagnostic approaches and improve patient management.

Shear Wave Elastography in the Assessment of Liver Iron Overload in Children With Beta Thalassemia Major

Abstract Shear wave elastography (SWE) is an ultrasound method that effectively demonstrates liver fibrosis. This prospective study aimed to compare magnetic resonance imaging T2* and SWE results of the liver in children with thalassemia major (TM). Patients with TM who had regular follow-ups were included. SWE was performed first, followed by MRI T2*. In addition, a healthy control group of the same age group, known to have no liver disease, was recruited. For these participants, only SWE was performed, and their results were compared with the SWE parameters of the TM patients. The study included 38 patients and 25 individuals who made up the control group. The groups with mild, moderate, and severe iron overload according to MRI T2* were compared in terms of SWE with parameters, and no statistically significant difference was found. However, when comparing the SWE parameters between the control group and patients, the median, average, and standard values were found to be statistically significantly higher in the patient group (P < 0.001, P < 0.001, P = 0.026). When comparing MRI T2* results, the median, average, and standard values were found to be statistically significantly higher in the patients with normal and mild iron overload (P < 0.001, P < 0.001, P = 0.033). SWE is an effective, more accessible, and easy-to-apply method for demonstrating early changes in the liver in pediatric patients with TM. This study serves as a guide for more comprehensive studies that may investigate the effect of SWE in this patient group.

Lasting liver injury following COVID-19 infection characterized by ultrasound shear wave elastography

ObjectiveTo assess for lasting hepatic injury using ultrasound shear wave elastography (SWE) in patients following COVID-19 infection. MethodsIn this retrospective cohort study, patients with SWE exams between January 2019 and 2022 were categorized into three groups: 1) post-COVID-19 subjects with positive COVID-19 PCR assay, 2) random sample of contemporaneous unexposed patients with only negative prior COVID-19 PCR tests, and 3) random sample of pre-pandemic patients to address possible undiagnosed COVID-19 infection in the contemporaneous group. The average difference in median Young’s modulus between post-COVID-19 patients and controls was calculated using a linear regression model after controlling for confounders. Results130 patients (mean age ± SD, 56 years ± 13; 66 women) were evaluated, including 30 patients after COVID-19 infection (mean age ± SD, 53 years ± 11; 15 women), 50 contemporaneous unexposed patients (mean age ± SD, 55 years ± 13; 27 men), and 50 pre-pandemic patients (mean age ± SD, 58 years ± 13; 28 women). SWE scans were performed on General Electric LOGIQ E9 or E10 an average of 44 (range, 12-81) weeks after COVID-19 infection. COVID-19 infection was associated with an average increase in median Young’s modulus of 1.5 kPa (95% CI [0.44, 2.355], p=0.006) after controlling for age, sex, obesity, history of chronic liver disease, and time period. Post-COVID-19 patients had higher liver stiffness compared to contemporaneous controls (median = 7.58 vs 5.99 kPa, p=0.001) but not pre-pandemic controls (median = 7.00 kPa, p=0.51). ConclusionsCOVID-19 infection is associated with increased liver stiffness, which may reflect lasting hepatic injury such as ongoing inflammation or the development of fibrosis. US SWE may serve as a noninvasive tool for long-term liver health monitoring after COVID-19 infection.

Assessment of the ulnar nerve stiffness during valgus stress of the elbow using shear wave elastography: an observational cross-sectional study.

Identification of the relationship between valgus stress in the medial elbow and ulnar nerve strain during maximum external rotation of the shoulder is pivotal for the prevention and management of ulnar neuropathies. In this observational cross-sectional study, we aimed to determine the changes in ulnar nerve stiffness under valgus stress at different nerve entrapment sites. Twenty healthy baseball players participated in the study. The stiffness of the ulnar nerve on the throwing side was assessed at two sites, the arcade of Struthers and the Osborne's ligament, at 0°, 60°, and 90° flexion by shear wave elastography using a 10-MHz linear transducer. The arcade of Struthers was defined as the proximal site and the Osborne's ligament as the distal site. Valgus stress was applied to the medial elbow at 0, 30, 50, and 70 N using a Telos stress device, and the stiffness caused by valgus stress was measured. At all elbow flexion angles, the stiffness of the ulnar nerve under 70 N valgus stress was higher than that under 30 N stress. The stiffness of the ulnar nerve at the proximal site was significantly higher than that at the distal site. Valgus stress increases ulnar nerve stiffness. In addition, the stiffness of the proximal site increases.

Comparison of Vs30 Value from Microtremor Data Based on SPT Drill Test of Young Merapi Deposits in Opak River, Yogyakarta

The 2006 Yogyakarta earthquake was caused by the tectonic movement of the Opak Fault, which is located near the Opak River. This research conducts microtremor data processing and analysis using the Horizontal Vertical Spectral Ratio (HVSR) method and the Inversion method to determine dominant frequency (fo), amplification (Ao), and shear wave velocity to a depth of 30 meters (Vs30) in Opak River area as an effort in earthquake disaster mitigation. The purpose of this research is to compare the Vs30 value of the inversion method using layer parameters according to Standard Penetration Test (SPT) data from previous research and layer parameters according to the number of lithologies. The result presents that the Vs30 values around Opak River are in the range of 183 - 301 m/s and belong to the stiff soil site classification. The comparison shows that the Vs30 values in the two different layer parameters are both still in the stiff soil site classification and have a slight difference in Vs30 values. Thus, the use of microseismic data to determine the Vs30 value is a fast and efficient way to determine the subsurface geology of the study area.

Effects of flywheel resistance training on countermovement jump performance and vastus lateralis muscle stiffness: A controlled study

ABSTRACT This study aimed to investigate the effects of an 8-week resistance training using flywheel (FW) device on countermovement jump (CMJ) performance and resting stiffness of the vastus lateralis (VL) muscle. Physically active adults were randomly assigned to a training intervention group (T; n = 18) and a control group (C; n = 13), which received no intervention. Jump performance variables and ultrasound-assessed resting VL shear modulus were measured before and after the intervention. Analysis of covariance revealed statistically significant group differences in jump height (T = +9%; C = -3%), rate of force development (T = +32%; C = +4%), peak power (T = +9%; C = -1%), and peak force (T = +7%; C = -1%). Jump performance improved only in the training group (all CMJ variables p < 0.05). Conversely, no significant changes within groups were observed in the resting shear wave modulus results (p > 0.05). VL stiffness decreased in the training group (−4%) and increased in the control group (+6%). Our results suggest that resistance training using FW device with individually allocated high-load FW inertia induces significant improvements in jump performance, which are not underpinned by changes in VL muscle stiffness.

Internally displaced persons (IDPs) in Azerbaijan: from protracted displacement to ‘Great Return’

ABSTRACT This article examines the host community’s response to the influx of internally displaced persons (IDPs) in Azerbaijan, focusing on social protection measures from the initial wave of forced displacement in the early 1990s to the end of the second Karabakh war in 2020. It evaluates ongoing government initiatives aimed at facilitating the return of IDPs to their places of origin. While IDPs have been integrated into state social protection programmes and benefited from state-provided social allowances and other benefits critical to their economic survival, the article highlights the importance of acknowledging their varied social needs and vulnerabilities to develop more targeted assistance policies. Based on the case study of Azerbaijan, this research contributes to the broader literature on social policy responses to protracted displacement and the challenges of IDP repatriation in the Global South.

Geotechnical and geophysical investigations for infrastructure safety zones: a case study of the supporting ring road, Cairo, Egypt

This study aims to evaluate the suitability of subsurface layers for infrastructure development using geophysical and geotechnical studies. Six seismic refraction and six 2D geoelectic profiles were conducted in the study area to analyze the geotechnical characteristics of the subsoil in order to assess its suitability for construction projects. According to the geophysical investigation, there are two main geoelectric strata, each with a different lithology and thickness. The first layer has high resistivity values of more than 200 (Ωm) and its thickness is between 3.5 and 6.3 m. The second layer's resistivity ranges from 0.3 to 200 (Ωm). The findings indicate that the near-surface area of the study site is composed of two layers in addition to the surface layer, which consists of semi-consolidated wadi fill deposits of gravel, sand, and silt with rock fragments. The first layer comprises fractured limestone with clay intercalation, followed by a second layer of marly limestone, which transitions into marl and clay. Both compressional (P) and shear (S) waves were detected and analyzed. The shallow seismic refraction technique indicates that the velocity waves (Vp) in the first and second layers range from 133 to 770 and 790 to 3100 m/s respectively. Various engineering parameters for the second layer were determined, including elastic moduli (bulk modulus, Poisson’s ratio, rigidity modulus, and Young’s modulus), competence scales (stress ratio, concentration index, material index and density gradient), and bearing capacity (ultimate and allowable). The average Poisson ratio for the first and second layers is 0.235. The ultimate bearing capacity (Qu) of the first layer ranges from 379.1 to 1031.2 gm/cm2 and between 1040.8 and 1548.5 gm/cm2 of the second layer. Allowable bearing capacity (Qall) for the first layer is between 126.4 and 343.7 gm/cm2, and for the second layer, it is between 346.9 and 516.2 gm/cm2. According to the geotechnical investigation's findings, the range of liquid limit (LL) values is between 41.20 and 86.30%, the range of plastic limit (PL) values is between 18 and 35.25%, the range of plasticity index (PI) values is between 14.17 and 51.45%, and the range of free swelling values is between 60 and 170%. However, the study identified high-risk areas in the study area. These zones are located in the first and second layers represented by strongly swelling clay layers and strongly fractured limestone, which will have a major impact on the road and buildings. Therefore, this study recommends addressing these problems before any development to protect these areas from subsidence and collapse.

Therapeutic efficacy of CRISPR RNA nanoparticles on cervical cancer disease using ultrasound elastography imaging

This work aimed to evaluate the therapeutic efficacy of clustered regularly interspaced short palindromic repeats (CRISPR) ribonucleic acid (RNA) nanoparticles (NPs) in the therapy of cervical cancer (CC) using ultrasound elastography imaging. Using poly(β-amino esters) (PBAE), CRISPR RNA NPs encapsulating Human Papillomavirus 16 (HPV16) E7, namely Poly(β-amino ester) (PBAE)/CRISPR16E7-GFP and PBAE/shRNA-16E7, were prepared. The characterization of these NPs was conducted using transmission electron microscopy (TEM) and laser diffraction particle size analysis. The cytotoxicity of PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 NPs on CC cell lines SiHa, HeLa, and CaSki was assessed using the cell counting kit-8 (CCK-8) assay. Sixty female Sprague Dawley (SD) rats were rolled into six groups randomlyas follows: the blank Ctrl group (Group A, no treatment), the model group (Group B, CC model), the pSpCas9-GFP plasmid group (Group C, CC model + pSpCas9-GFP), the PBAE/CRISPR-16E7 group (Group D, CC model + PBAE/CRISPR-16E7), the pSIREN-U6-shRNA-CMV-iRFP plasmid group (Group E, CC model + pSIREN-U6-shRNA-CMV-iRFP), and the PBAE/shRNA-16E7 group (Group F, CC model + PBAE/shRNA-16E7), each consisting of 10 rats. The impact of NPs on the expression levels (ELs) of HPV16E7 and RB1 proteins in tumor tissues was assessed using Western Blot (WB) analysis. Additionally, ultrasound elastography imaging was employed to analyze the strain ratio (SR) and shear wave velocity (SWV) in lesions of various rat groups. The results indicated that the PBAE/CRISPR16E7-GFP NPs exhibited a particle size of 125.64 ± 7.8 nm, a zeta potential of 19.17 ± 3.61 mV, and a polydispersity index (PDI) of 0.281 ± 0.03. These NPs demonstrated a regular spherical structure with a compact morphology. The PBAE/shRNA-16E7 NPs displayed a particle size of 112.93 ± 9.1 nm, a zeta potential of 13.54 ± 1.39 mV, and a PDI of 0.185 ± 0.03. They exhibited a uniform distribution of spherical shape with regularity in size. The plasmids within PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 NPs exhibited distinct trends of burst and sustained release. The viability of SiHa, HeLa, and CaSki cells remained unaffected by PBAE/CRISPR16E7-GFP NPs. At various mass ratios, neglectable differences (P > 0.05) were observed in cell viability of SiHa, HeLa, and CaSki cells treated with PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 NPs relative to Ctrl group. Relative to Group B, both Groups C and E exhibited a drastic decrease in tumor volume, tumor mass, and HPV16E7 protein ELs (P < 0.05), whereas Groups D and F showed a notably greater reduction in tumor volume, tumor mass, and HPV16E7 protein ELs (P < 0.01). The HPV16E7 protein ELs, SR, and SWV values greatly increased (P < 0.001) in tumors of Group B rats while the EL of RB1 protein notably decreased (P < 0.001) versus Group A. Groups C and E demonstrated elevated HPV16E7 ELs, SR, and SWV values (P < 0.05), with a marked decrease in RB1 protein EL (P < 0.001). Group F exhibited a notable reduction in HPV16E7 protein levels, SR, and SWV values (P < 0.001).The CRISPRRNA NPs composed of PBAE encapsulating HPV16 E7, namely PBAE/CRISPR16E7-GFP and PBAE/shRNA-16E7 plasmids, demonstrated a significant role in CC therapy. These NPs hold potential application value in the treatment of HPV-related CC, indicating their importance in addressing this particular disease.

Estimation of shear wave velocity using rock mass property of Gemlik, Turkey

ABSTRACT It is often required to evaluate the shear wave velocity (V s ) of the sub-soil stratification for the seismic site characterisation and various engineering applications where the dynamic forces are acting on the foundation. Different correlations are available based on the Standard Penetration Test (SPT) for this purpose when the sub-soil stratification consists of soil. However, limited studies were performed to develop such correlations in case of weathered and fractured rock formations. In this paper, a correlation is developed between the depth of measurement, shear wave velocity, and Rock Mass Rating (RMR) based on Multichannel Analysis of Surface Waves (MASW) test, and the borehole data conducted in the Gemlik region of Turkey. The accuracy of the proposed correlation is checked using different statistical plots and found to be acceptable for the evaluation of V s . This correlation can be used by the practicing engineers for the preliminary estimate of V s in a fractured rock mass based on the borehole information and laboratory testing in absence of dynamic field testing for this region. Based on the findings from this study, V s is observed to be increasing with an increase in depth of investigation and RMR in a fractured rock mass of Gemlik, Turkey.

Interferometric image reorganization and screening method based on phase-shift convergence criterion

To address the challenge of obtaining high-quality interferometric images in the presence of environmental disturbances, this paper proposes a method for interferometric image reorganization and screening based on the phase-shift convergence criterion. The method begins with the acquisition of multiple sets of interferometric images, which are subsequently classified and reorganized according to the amount of phase shift. A mean absolute deviation metric is then employed to systematically screen the classified images, allowing for the selection of a subset that exhibits accurate phase shifts. Finally, the screened and combined interferometric images are evaluated for phase shift centralization through the calculation of the coefficient of variation, ensuring that the screened images conform to the expected criteria. The experimental results indicate that the average coefficient of variation of the screened interferometric images obtained using the proposed method is significantly reduced by 0.1236, 0.0968, and 0.1042 when compared to the nine sets of directly acquired interferometric images subjected to high-frequency vibration, high-amplitude vibration, and transverse distortion vibration, respectively. These data demonstrate that the proposed method can effectively adapt to various vibration environments while screening interferometric images of higher quality. Consequently, this method offers a novel approach to enhancing the vibration resistance of interferometers.

Assessing the diagnostic and therapeutic value of submandibular gland elastography in patients with immunoglobulin G4-related sialadenitis.

: To investigate the utility of shear wave elastography values (SWE) in differentiating IgG4-related submandibular sialadenitis (IgG4-RSS) from healthy individuals and in monitoring the response to glucocorticoid treatment. : Patients with IgG4-RSS who underwent ultrasound between 2017 and 2023 were included. Gland size, border, internal echo pattern, vascularity, and SWE were measured. These parameters were compared with those of the healthy controls, and before and after treatment. Thirty-one glands from 16 patients were analysed. All glands had a nodular shape; the nodular hypoechoic was the most prevalent pattern, followed by the diffuse hypoechoic; the reticular was the least common. Most glands had rich vascularity, whereas two glands had minimal vascularity. The depth (mean 18 mm) and SWE (mean 3.57 m/s) were significantly higher in IgG-RSS (P=0.003 and <0.001, respectively) than in the healthy controlsNine glands from five patients were enrolled to evaluate the treatment response. After treatment, the margins became smoother and all glands showed a reduction in size, hypoechoic area, and vascularity. The mean SWE decreased from 3.56 m/s to 2.50 m/s with a significant difference between pre- and post-treatment (P= <0.001). The SWE is useful for diagnosing IgG4-RSS and assessing the effectiveness of treatment.

Geophysical downhole logging analysis within the shallow-depth ICDP STAR drilling project (central Italy)

Abstract. The International Continental Scientific Drilling Program (ICDP) STAR (A Strainmeter Array Along the Alto Tiberina Fault System) drilling project aims to study the seismic and aseismic fault slip behavior of the active low-angle Alto Tiberina normal fault (ATF) in the northern Apennines, central Italy, by drilling and instrumenting six shallow boreholes (maximum depth 160 m) with seismometers and strainmeters. During the STAR fieldwork, a geophysical downhole logging campaign was carried out to define the optimal target depth for instrument deployment and formation rock characterization. In particular, the main objectives of this study were to define in situ physical properties of the rocks and the tectonic discontinuity geometry along the boreholes. The downhole logging data provide new findings and knowledge, especially with regards to physical properties such as resistivity and gamma-ray and wave velocity. The collected parameters were compared to the results of literature data collected in similar lithologies, as well as with the results of logging performed in deeper wells drilled for commercial purposes. The physical properties of the Mesozoic–early Tertiary calcareous formations show low gamma-ray values and high compressional (Vp) and shear wave (Vs) velocities (up to 5.3 and 2.9 km s−1, respectively), whereas the overlying clay-rich Late Tertiary formations exhibit high gamma-ray and low resistivity values as well as relatively low Vp and Vs values (up to 3.5 and 2.0 km s−1, respectively). The results obtained from the analysis of the orientations of the tectonic structures, measured along the six boreholes, show good agreement with the orientations of the present-day extensional stress field, which is NE–SW-oriented. Our study allowed us to bridge the gap between the physical properties obtained from literature data and those obtained from the deep well measurements, representing a possible case history for future projects. These new outcomes represent an almost unexplored window of data and will contribute to the advancement of knowledge of the physical properties of the rocks at shallow depths, which are typically overlooked.

Does shear wave elastography technology provide better value for the assessment of perianal fistulizing Crohn’s disease?

Magnetic resonance imaging is the gold standard compared other clinical findings. But shear wave elastography technique combined with endoscopic ultrasound can evaluate the degree of fibrosis of fistula tissue in Crohn’s disease patients. This topic is highly relevant to the current discourse, especially for It shows a certain degree of innovation and practicality and is worthy of study and popularization.