Ultrasonic baths and sonochemical reactors are widely used in industrial applications dealing with surface cleaningand chemical synthesis. The processes of erosion, cleaning and structuring of the surface can be typic...Ultrasonic baths and sonochemical reactors are widely used in industrial applications dealing with surface cleaningand chemical synthesis. The processes of erosion, cleaning and structuring of the surface can be typically controlledby changing relevant influential parameters. In particular, in this work, we experimentally investigate theeffect of NaCl concentration (0–5.5 mol/L) on the erosion of an aluminum foil under ultrasonic exposure at afrequency of 28 kHz. Special attention is paid to the determination of cavitation zones and their visualizationusing heat maps. It is found that at low NaCl concentration (0.3 mol/L), the foil destruction rate is higher thanin distilled water. At higher concentrations of salt, cavitation takes place mainly in the upper part of the container.展开更多
The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis,extraction and separation.One of the most important mechanisms at play in such processes is ...The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis,extraction and separation.One of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the chamber.Cavitation has a strong impact on the surface degradation mechanisms.In this work,a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL Multiphysics.The numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions for various thicknesses of the piezoelectric transducer.In particular,the amplitude of the acoustic pressure is minimal in the case of absorbing boundaries,and the attenuation becomes more significant as the thickness of the piezoelectric transducer increases.In addition,reflective boundaries play a significant role in the formation and distribution of zones of maximum cavitation activity.展开更多
Liver disease accounts for approximately 2 million deaths per year worldwide.All chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the struct...Liver disease accounts for approximately 2 million deaths per year worldwide.All chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the structure of the tissue.These changes may include the accumulation of extracellular matrix material,fats,triglycerides,or tissue scarring.Noninvasive methods for diagnosing CLD,such as conventional B-mode ultrasound(US),play a significant role in diagnosis.Doppler US,when coupled with B-mode US,can be helpful in evaluating the hemodynamics of hepatic vessels and detecting US findings associated with hepatic decompensation.US elastography can assess liver stiffness,serving as a surrogate marker for liver fibrosis.It is important to note that interpreting these values should not rely solely on a histological classification.Contrast-enhanced US(CEUS)provides valuable information on tissue perfusion and enables excellent differentiation between benign and malignant focal liver lesions.Clinical evaluation,the etiology of liver disease,and the patient current comorbidities all influence the interpretation of liver stiffness measurements.These measurements are most clinically relevant when interpreted as a probability of compensated advanced CLD.B-mode US offers a subjective estimation of fatty infiltration and has limited sensitivity for mild steatosis.The controlled attenuation parameter requires a dedicated device,and cutoff values are not clearly defined.Quan-titative US parameters for liver fat estimation include the attenuation coefficient,backscatter coefficient,and speed of sound.These parameters offer the advantage of providing fat quantification alongside B-mode evaluation and other US parameters.Multiparametric US(MPUS)of the liver introduces a new concept for complete noninvasive diagnosis.It encourages examiners to utilize the latest features of an US machine,including conventional B-mode,liver stiffness evaluation,fat quantification,dispersion imaging,Doppler US,and CEUS for focal liver lesion characterization.This comprehensive approach allows for diagnosis in a single examination,providing clinicians worldwide with a broader perspective and becoming a cornerstone in their diagnostic arsenal.MPUS,in the hands of skilled clinicians,becomes an invaluable predictive tool for diagnosing,staging,and monitoring CLD.展开更多
Endoscopic ultrasound(EUS) has become a well accepted test for the diagnosis of chronic pancreatitis.Advantages include its ability to detect subtle and severe changes of the pancreatic duct and parenchyma,and its rel...Endoscopic ultrasound(EUS) has become a well accepted test for the diagnosis of chronic pancreatitis.Advantages include its ability to detect subtle and severe changes of the pancreatic duct and parenchyma,and its relative safety compared with endoscopic retrograde cholangiopancreatography.Limitations include inter-and intraobserver variability,operator dependence,and an incomplete understanding of its true accuracy.The Rosemont classif ication has recently been proposed as a weighted,standardized method that may improve EUS chronic pancreatitis scoring.This paper reviews the published evidence regarding the accuracy of EUS in chronic pancreatitis diagnosis,and enumerates the emerging technologies that have been recently studied which may ultimately improve endosonographic imaging of the pancreas.展开更多
BACKGROUND Carcinoembryonic antigen(CEA)and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms.Genetic testing and microforceps biopsy are promising tools for pre-operativ...BACKGROUND Carcinoembryonic antigen(CEA)and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms.Genetic testing and microforceps biopsy are promising tools for pre-operative diagnostic improvement but comparative performance of both methods is unknown.AIM To compare the accuracy of genetic testing and microforceps biopsy in pancreatic cysts referred for surgery.METHODS We performed a literature search in Medline,Scopus,and Web of Science for studies evaluating genetic testing of cystic fluid and microforceps biopsy of pancreatic cysts,with endoscopic ultrasound with fine-needle aspiration(EUSFNA)prior to surgery and surgical pathology as reference standard for diagnosis.We evaluated the diagnostic accuracy for:1-benign cysts;2-mucinous low-risk cysts;3-high-risk cysts,and the diagnostic yield and rate of correctly identified cysts with microforceps biopsy and molecular analysis.We also assessed publication bias,heterogeneity,and study quality.RESULTS Eight studies,including 1206 patients,of which 203(17%)referred for surgery who met the inclusion criteria were analyzed in the systematic review,and seven studies were included in the meta-analysis.Genetic testing and microforceps biopsies were identical for diagnosis of benign cysts.Molecular analysis was superior for diagnosis of both low and high-risk mucinous cysts,with sensitivities of 0.89(95%CI:0.79-0.95)and 0.57(95%CI:0.42-0.71),specificities of 0.88(95%CI:0.75-0.95)and 0.88(95%CI:0.80-0.93)and AUC of 0.9555 and 0.92,respectively.The diagnostic yield was higher in microforceps biopsies than in genetic analysis(0.73 vs 0.54,respectively)but the rates of correctly identified cysts were identical(0.73 with 95%CI:0.62-0.82 vs 0.71 with 95%CI:0.49-0.86,respectively).CONCLUSION Genetic testing and microforceps biopsies are useful second tests,with identical results in benign pancreatic cysts.Genetic analysis performs better for low-and high-risk cysts but has lower diagnostic yield.展开更多
The role of endoscopic ultrasound(EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within...The role of endoscopic ultrasound(EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration(FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA(EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition(needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy.展开更多
This paper proposes a new search strategy using mutative scale chaos optimization algorithm (MSCO) for model selection of support vector machine (SVM). It searches the parameter space of SVM with a very high effic...This paper proposes a new search strategy using mutative scale chaos optimization algorithm (MSCO) for model selection of support vector machine (SVM). It searches the parameter space of SVM with a very high efficiency and finds the optimum parameter setting for a practical classification problem with very low time cost. To demonstrate the performance of the proposed method it is applied to model selection of SVM in ultrasonic flaw classification and compared with grid search for model selection. Experimental results show that MSCO is a very powerful tool for model selection of SVM, and outperforms grid search in search speed and precision in ultrasonic flaw classification.展开更多
Background and Aim: Visceral leishmaniasis (VL), also known as kala azar, is a parasitic disease that caused by infection with Leishmania parasites, which are spread by the bite of phlebotomine sand flies. An ultrasou...Background and Aim: Visceral leishmaniasis (VL), also known as kala azar, is a parasitic disease that caused by infection with Leishmania parasites, which are spread by the bite of phlebotomine sand flies. An ultrasound examination is strongly advocated for the promote diagnosis and treatment of VL for long term follow up and evaluation of unresponsive cases. The aim of this study was to assess the consequences of VL in the liver, spleen and pancreas of affected participants by using ultrasound. Materials and Methods: A prospective cohort study was conducted in the period of January 2012 to March 2014 in the ultrasound department of Tropical Disease Hospital (TDH) in Khartoum-Sudan, among a group of 100 participants (84% males, 16% females and their ages ranges from 15 to 45 years) positive to VL and had been diagnosed by laboratory tests;either serological or Napier’s Aldehyde test. The Aloka portable ultrasound machine equipped with 3.5 MHz convex probe was used for abdominal ultrasound scanning. Standard Statistical Package for the Social Sciences (SPSS) was used to analyze the results. Results: The commonest ultrasound findings in VL participants were hepatomegaly (100%), splenomegaly (100%) and ascites (50%). Other complications such as lymphadenopathy (35%), focal splenic lesions (34%), dilated portal vein (7%) and shrinkage liver (4%) were detected. Conclusion: Ultrasound scanning presents an effective role in VL, because of its ability to detect the consequences of this disease in various abdominal organs such as liver, spleen and pancreas earlier, which in turn allowing the possibility to treat these complications and prevents the deterioration of a patient’s health status.展开更多
BACKGROUND Genetic tests are increasingly performed for the management of unresectable pancreatic cancer.For genotyping aimed samples current guidelines recommend using core specimens,although based on moderate qualit...BACKGROUND Genetic tests are increasingly performed for the management of unresectable pancreatic cancer.For genotyping aimed samples current guidelines recommend using core specimens,although based on moderate quality evidence.However,in clinical practice among the endoscopic ultrasound(EUS) guided tissue acquisition methods,fine needle aspiration(FNA) is the most widely performed.AIM To assess the adequacy for next generation sequencing(NGS) of the DNA yielded from EUS-FNA pancreatic adenocarcinoma(PDAC) samples.METHODS Between November 2018 and December 2021,105 patients with PDAC confirmed by EUS-FNA were included in the study at our tertiary gastroenterology center.Either 22 gauge(G) or 19G FNA needles were used.One pass was dedicated to DNA extraction.DNA concentration and purity(A260/280,A260/230) were assessed by spectrophotometry.We assessed the differences in DNA parameters according to needle size and tumor characteristics(size,location) and the adequacy of the extracted DNA for NGS(defined as A260/280 ≥ 1.7,and DNA yield:≥ 10 ng for amplicon based NGS,≥ 50 ng for whole exome sequencing [WES],≥ 100 ng for whole genome sequencing [WGS]) by analysis of variance and ttest respectively.Moreover,we compared DNA purity parameters across the different DNA yield categories.RESULTS Our cohort included 49% male patients,aged 67.02 ± 8.38 years.The 22G needle was used in 71%of the cases.The DNA parameters across our samples varied as follows:DNA yield:1289 ng(inter quartile range:534.75-3101),A260/280 = 1.85(1.79-1.86),A260/230 = 2.2(1.72-2.36).DNA yield was > 10 ng in all samples and > 100 ng in 93% of them(one sample < 50 ng).There were no significant differences in the concentration and A260/280 between samples by needle size.Needle size was the only independent predictor of A260/230 which was higher in the 22G samples(P =0.038).NGS adequacy rate was 90% for 19G samples regardless of NGS type,and for 22G samples it reached 89% for WGS adequacy and 91% for WES and amplicon based NGS.Samples with DNA yield > 100 ng had significantly higher A260/280(1.89 ± 0.32 vs 1.34 ± 0.42,P = 0.013).Tumor characteristics were not corelated with the DNA parameters.CONCLUSION EUS-FNA PDAC samples yield DNA adequate for subsequent NGS.DNA amount was similar between 22G and 19G FNA needles.DNA purity parameters may vary indirectly with needle size.展开更多
There are several thousand piping components in a nuclear power plant. These components are affected by degradation mechanisms such as FAC (Flow-Accelerated Corrosion), cavitation, flashing, and LDI (Liquid Droplet Im...There are several thousand piping components in a nuclear power plant. These components are affected by degradation mechanisms such as FAC (Flow-Accelerated Corrosion), cavitation, flashing, and LDI (Liquid Droplet Impingement). Therefore, nuclear power plants implement inspection programs to detect and control damages caused by such mechanisms. UT (Ultrasonic Test), one of the non-destructive tests, is the most commonly used method for inspecting the integrity of piping components. According to the management plan, several hundred components, being composed of as many as 100 to 300 inspection data points, are inspected during every RFO (Re-Fueling Outage). To acquire UT data of components, a large amount of expense is incurred. It is, however, difficult to find a proper method capable of verifying the reliability of UT data prior to the wear rate evaluation. This study describes the review of UT evaluation process and the influence of UT measurement error. It is explored that SAM (Square Average Method), which was suggested as a method for reliability analysis in the previous study, is found to be suitable for the determination whether the measured thickness is acceptable or not. And, safety factors are proposed herein through the statistical analysis taking into account the components’ type.展开更多
A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures.In this algorithm,...A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures.In this algorithm,a hybrid regularizations-based iterative Newton method is implemented to provide stable inverse solutions.Furthermore,a dual mesh scheme and an adjoint method are adopted to reduce the computation cost and improve the efficiency of reconstruction.Simultaneous reconstruction of both acoustic velocity and attenuation coefficient for a reinforced concrete model is achieved with multiple frequency data.The algorithm is evaluated with numerical simulation under various practical scenarios including varied transmission/receiving modes,different noise levels,different source/detector numbers,and different contrast levels between the heterogeneity and background region.Results obtained suggest that the algorithm is insensitive to noise,and the reconstructions are quantitatively accurate in terms of the location,size and acoustic properties of the target over a range of contrast levels.展开更多
Objective: High frequency ultrasound combined with policy thermal perception testing (QTT) was used to analyze the characteristics of nerve damage in diabetic peripheral neuropathy (DPN), and then provided the basis f...Objective: High frequency ultrasound combined with policy thermal perception testing (QTT) was used to analyze the characteristics of nerve damage in diabetic peripheral neuropathy (DPN), and then provided the basis for the clinical prevention, diagnosis and treatment of DPN. Methods: A total of 110 DPN patients admitted to the hospital from December 2015 to May 2018 were selected, and the characteristics of nerve damage in diabetic peripheral neuropathy were analyzed by ultrasound and QTT. Results: In the results of QTT, the abnormal proportion of the CDT, WDT, CPT and HPT of the lower limbs in DPN's were all higher than the upper limbs;The difference of WDT and HPT in the age and course groups of patients in the upper limbs was statistically significant, the abnormal proportion of WDT and HPT in patients aged 60 years or above or with a course of 10 years or more were all above 45%, higher than those in other groups. The patients with larger mean amplitude of glycemic excursions (MAGE) were significantly higher than those with smaller MAGE, regardless of the abnormal proportion of WDT and HPT observed in upper limbs, lower limbs or upper and lower limbs;The results of ultrasonic measurement of nerve cross sectional area showed: the proportion of patients with ulnar nerve and median nerve abnormally thickened in the high age group (≥45 years) and the long course group (>10 years) was significantly higher than that in the low age group (<45 years) and the short course group (<10 years), the proportion of patients with larger MAGE with abnormal enlargement of median nerve was significantly higher than those with smaller MAGE. The thickening of ulnar nerve, median nerve and peroneal nerve was obvious in the patients of MAGE > 4 mmol/L. Conclusion: (1) The main nerve damage in DPN patients was thermal sensation damage, and the lower limb nerve was more vulnerable than the upper limb nerve. (2) The incidence of ulnar and median nerve damage was higher in patients aged 45 years and older or over 10 years of course. (3) Patients with large MAGE (> 4 mmo/L) had higher incidence of median nerve damage. The above characteristics of nerve damage can provide basis for clinical prevention, diagnosis and treatment of DPN.展开更多
It is crucial to maintain wind turbine blades regularly, due to the high stress leading to defects or damage. Conventional methods require shipping the blades to a workshop for off-site inspection, which is extremely ...It is crucial to maintain wind turbine blades regularly, due to the high stress leading to defects or damage. Conventional methods require shipping the blades to a workshop for off-site inspection, which is extremely time-consuming and very costly. This work investigates the use of pulse-echo ultrasound to detect internal damages in wind turbine blades without the necessity to ship the blades off-site. A prototype 2D ultrasonic NDT (non-destructive testing) system has been developed and optimised for in-situ wind turbine blade inspection. The system is designed to be light weight so it can be easily carried by an inspector onto the wind turbine blade for in-situ inspection. It can be operated in 1D A-scan, 2D C-scan or 3D volume scan. A software system has been developed to control the automated scanning and show the damage areas in a 2D/3D map with different colours so that the inspector can easily identify the defective areas. Experiments on GFRP (glass fibre reinforced plastics) and wind turbine blades (made of GFRP) samples showed that internal defects can be detected. The main advantages of this system are fully automated 2D spatial scanning and the ability to alert the user to the damage of the inspected sample. It is intended to be used for in-situ inspection to save maintenance time and hence considered to be economically beneficial for the wind energy industry.展开更多
文摘Ultrasonic baths and sonochemical reactors are widely used in industrial applications dealing with surface cleaningand chemical synthesis. The processes of erosion, cleaning and structuring of the surface can be typically controlledby changing relevant influential parameters. In particular, in this work, we experimentally investigate theeffect of NaCl concentration (0–5.5 mol/L) on the erosion of an aluminum foil under ultrasonic exposure at afrequency of 28 kHz. Special attention is paid to the determination of cavitation zones and their visualizationusing heat maps. It is found that at low NaCl concentration (0.3 mol/L), the foil destruction rate is higher thanin distilled water. At higher concentrations of salt, cavitation takes place mainly in the upper part of the container.
文摘The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis,extraction and separation.One of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the chamber.Cavitation has a strong impact on the surface degradation mechanisms.In this work,a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL Multiphysics.The numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions for various thicknesses of the piezoelectric transducer.In particular,the amplitude of the acoustic pressure is minimal in the case of absorbing boundaries,and the attenuation becomes more significant as the thickness of the piezoelectric transducer increases.In addition,reflective boundaries play a significant role in the formation and distribution of zones of maximum cavitation activity.
文摘Liver disease accounts for approximately 2 million deaths per year worldwide.All chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the structure of the tissue.These changes may include the accumulation of extracellular matrix material,fats,triglycerides,or tissue scarring.Noninvasive methods for diagnosing CLD,such as conventional B-mode ultrasound(US),play a significant role in diagnosis.Doppler US,when coupled with B-mode US,can be helpful in evaluating the hemodynamics of hepatic vessels and detecting US findings associated with hepatic decompensation.US elastography can assess liver stiffness,serving as a surrogate marker for liver fibrosis.It is important to note that interpreting these values should not rely solely on a histological classification.Contrast-enhanced US(CEUS)provides valuable information on tissue perfusion and enables excellent differentiation between benign and malignant focal liver lesions.Clinical evaluation,the etiology of liver disease,and the patient current comorbidities all influence the interpretation of liver stiffness measurements.These measurements are most clinically relevant when interpreted as a probability of compensated advanced CLD.B-mode US offers a subjective estimation of fatty infiltration and has limited sensitivity for mild steatosis.The controlled attenuation parameter requires a dedicated device,and cutoff values are not clearly defined.Quan-titative US parameters for liver fat estimation include the attenuation coefficient,backscatter coefficient,and speed of sound.These parameters offer the advantage of providing fat quantification alongside B-mode evaluation and other US parameters.Multiparametric US(MPUS)of the liver introduces a new concept for complete noninvasive diagnosis.It encourages examiners to utilize the latest features of an US machine,including conventional B-mode,liver stiffness evaluation,fat quantification,dispersion imaging,Doppler US,and CEUS for focal liver lesion characterization.This comprehensive approach allows for diagnosis in a single examination,providing clinicians worldwide with a broader perspective and becoming a cornerstone in their diagnostic arsenal.MPUS,in the hands of skilled clinicians,becomes an invaluable predictive tool for diagnosing,staging,and monitoring CLD.
文摘Endoscopic ultrasound(EUS) has become a well accepted test for the diagnosis of chronic pancreatitis.Advantages include its ability to detect subtle and severe changes of the pancreatic duct and parenchyma,and its relative safety compared with endoscopic retrograde cholangiopancreatography.Limitations include inter-and intraobserver variability,operator dependence,and an incomplete understanding of its true accuracy.The Rosemont classif ication has recently been proposed as a weighted,standardized method that may improve EUS chronic pancreatitis scoring.This paper reviews the published evidence regarding the accuracy of EUS in chronic pancreatitis diagnosis,and enumerates the emerging technologies that have been recently studied which may ultimately improve endosonographic imaging of the pancreas.
文摘BACKGROUND Carcinoembryonic antigen(CEA)and cytology in pancreatic cystic fluid are suboptimal for evaluation of pancreatic cystic neoplasms.Genetic testing and microforceps biopsy are promising tools for pre-operative diagnostic improvement but comparative performance of both methods is unknown.AIM To compare the accuracy of genetic testing and microforceps biopsy in pancreatic cysts referred for surgery.METHODS We performed a literature search in Medline,Scopus,and Web of Science for studies evaluating genetic testing of cystic fluid and microforceps biopsy of pancreatic cysts,with endoscopic ultrasound with fine-needle aspiration(EUSFNA)prior to surgery and surgical pathology as reference standard for diagnosis.We evaluated the diagnostic accuracy for:1-benign cysts;2-mucinous low-risk cysts;3-high-risk cysts,and the diagnostic yield and rate of correctly identified cysts with microforceps biopsy and molecular analysis.We also assessed publication bias,heterogeneity,and study quality.RESULTS Eight studies,including 1206 patients,of which 203(17%)referred for surgery who met the inclusion criteria were analyzed in the systematic review,and seven studies were included in the meta-analysis.Genetic testing and microforceps biopsies were identical for diagnosis of benign cysts.Molecular analysis was superior for diagnosis of both low and high-risk mucinous cysts,with sensitivities of 0.89(95%CI:0.79-0.95)and 0.57(95%CI:0.42-0.71),specificities of 0.88(95%CI:0.75-0.95)and 0.88(95%CI:0.80-0.93)and AUC of 0.9555 and 0.92,respectively.The diagnostic yield was higher in microforceps biopsies than in genetic analysis(0.73 vs 0.54,respectively)but the rates of correctly identified cysts were identical(0.73 with 95%CI:0.62-0.82 vs 0.71 with 95%CI:0.49-0.86,respectively).CONCLUSION Genetic testing and microforceps biopsies are useful second tests,with identical results in benign pancreatic cysts.Genetic analysis performs better for low-and high-risk cysts but has lower diagnostic yield.
文摘The role of endoscopic ultrasound(EUS) in evaluating pancreatic pathology has been well documented from the beginning of its clinical use. High spatial resolution and the close proximity to the evaluated organs within the mediastinum and abdominal cavity allow detection of small focal lesions and precise tissue acquisition from suspected lesions within the reach of this method. Fine needle aspiration(FNA) is considered of additional value to EUS and is performed to obtain tissue diagnosis. Tissue acquisition from suspected lesions for cytological or histological analysis allows, not only the differentiation between malignant and non-malignant lesions, but, in most cases, also the accurate distinction between the various types of malignant lesions. It is well documented that the best results are achieved only if an adequate sample is obtained for further analysis, if the material is processed in an appropriate way, and if adequate ancillary methods are performed. This is a multi-step process and could be quite a challenge in some cases. In this article, we discuss the technical aspects of tissue acquisition by EUS-guided-FNA(EUS-FNA), as well as the role of an on-site cytopathologist, various means of specimen processing, and the selection of the appropriate ancillary method for providing an accurate tissue diagnosis and maximizing the yield of this method. The main goal of this review is to alert endosonographers, not only to the different possibilities of tissue acquisition, namely EUS-FNA, but also to bring to their attention the importance of proper sample processing in the evaluation of various lesions in the gastrointestinal tract and other accessible organs. All aspects of tissue acquisition(needles, suction, use of stylet, complications, etc.) have been well discussed lately. Adequate tissue samples enable comprehensive diagnoses, which answer the main clinical questions, thus enabling targeted therapy.
基金Project supported by National High-Technology Research and De-velopment Program of China (Grant No .863-2001AA602021)
文摘This paper proposes a new search strategy using mutative scale chaos optimization algorithm (MSCO) for model selection of support vector machine (SVM). It searches the parameter space of SVM with a very high efficiency and finds the optimum parameter setting for a practical classification problem with very low time cost. To demonstrate the performance of the proposed method it is applied to model selection of SVM in ultrasonic flaw classification and compared with grid search for model selection. Experimental results show that MSCO is a very powerful tool for model selection of SVM, and outperforms grid search in search speed and precision in ultrasonic flaw classification.
文摘Background and Aim: Visceral leishmaniasis (VL), also known as kala azar, is a parasitic disease that caused by infection with Leishmania parasites, which are spread by the bite of phlebotomine sand flies. An ultrasound examination is strongly advocated for the promote diagnosis and treatment of VL for long term follow up and evaluation of unresponsive cases. The aim of this study was to assess the consequences of VL in the liver, spleen and pancreas of affected participants by using ultrasound. Materials and Methods: A prospective cohort study was conducted in the period of January 2012 to March 2014 in the ultrasound department of Tropical Disease Hospital (TDH) in Khartoum-Sudan, among a group of 100 participants (84% males, 16% females and their ages ranges from 15 to 45 years) positive to VL and had been diagnosed by laboratory tests;either serological or Napier’s Aldehyde test. The Aloka portable ultrasound machine equipped with 3.5 MHz convex probe was used for abdominal ultrasound scanning. Standard Statistical Package for the Social Sciences (SPSS) was used to analyze the results. Results: The commonest ultrasound findings in VL participants were hepatomegaly (100%), splenomegaly (100%) and ascites (50%). Other complications such as lymphadenopathy (35%), focal splenic lesions (34%), dilated portal vein (7%) and shrinkage liver (4%) were detected. Conclusion: Ultrasound scanning presents an effective role in VL, because of its ability to detect the consequences of this disease in various abdominal organs such as liver, spleen and pancreas earlier, which in turn allowing the possibility to treat these complications and prevents the deterioration of a patient’s health status.
基金The Executive Agency for Higher Education,Research,Development and Innovation Funding-research,No.PN-Ⅲ-P1-1.2-PCCDI-2017-0797 (PANCNGS)
文摘BACKGROUND Genetic tests are increasingly performed for the management of unresectable pancreatic cancer.For genotyping aimed samples current guidelines recommend using core specimens,although based on moderate quality evidence.However,in clinical practice among the endoscopic ultrasound(EUS) guided tissue acquisition methods,fine needle aspiration(FNA) is the most widely performed.AIM To assess the adequacy for next generation sequencing(NGS) of the DNA yielded from EUS-FNA pancreatic adenocarcinoma(PDAC) samples.METHODS Between November 2018 and December 2021,105 patients with PDAC confirmed by EUS-FNA were included in the study at our tertiary gastroenterology center.Either 22 gauge(G) or 19G FNA needles were used.One pass was dedicated to DNA extraction.DNA concentration and purity(A260/280,A260/230) were assessed by spectrophotometry.We assessed the differences in DNA parameters according to needle size and tumor characteristics(size,location) and the adequacy of the extracted DNA for NGS(defined as A260/280 ≥ 1.7,and DNA yield:≥ 10 ng for amplicon based NGS,≥ 50 ng for whole exome sequencing [WES],≥ 100 ng for whole genome sequencing [WGS]) by analysis of variance and ttest respectively.Moreover,we compared DNA purity parameters across the different DNA yield categories.RESULTS Our cohort included 49% male patients,aged 67.02 ± 8.38 years.The 22G needle was used in 71%of the cases.The DNA parameters across our samples varied as follows:DNA yield:1289 ng(inter quartile range:534.75-3101),A260/280 = 1.85(1.79-1.86),A260/230 = 2.2(1.72-2.36).DNA yield was > 10 ng in all samples and > 100 ng in 93% of them(one sample < 50 ng).There were no significant differences in the concentration and A260/280 between samples by needle size.Needle size was the only independent predictor of A260/230 which was higher in the 22G samples(P =0.038).NGS adequacy rate was 90% for 19G samples regardless of NGS type,and for 22G samples it reached 89% for WGS adequacy and 91% for WES and amplicon based NGS.Samples with DNA yield > 100 ng had significantly higher A260/280(1.89 ± 0.32 vs 1.34 ± 0.42,P = 0.013).Tumor characteristics were not corelated with the DNA parameters.CONCLUSION EUS-FNA PDAC samples yield DNA adequate for subsequent NGS.DNA amount was similar between 22G and 19G FNA needles.DNA purity parameters may vary indirectly with needle size.
文摘There are several thousand piping components in a nuclear power plant. These components are affected by degradation mechanisms such as FAC (Flow-Accelerated Corrosion), cavitation, flashing, and LDI (Liquid Droplet Impingement). Therefore, nuclear power plants implement inspection programs to detect and control damages caused by such mechanisms. UT (Ultrasonic Test), one of the non-destructive tests, is the most commonly used method for inspecting the integrity of piping components. According to the management plan, several hundred components, being composed of as many as 100 to 300 inspection data points, are inspected during every RFO (Re-Fueling Outage). To acquire UT data of components, a large amount of expense is incurred. It is, however, difficult to find a proper method capable of verifying the reliability of UT data prior to the wear rate evaluation. This study describes the review of UT evaluation process and the influence of UT measurement error. It is explored that SAM (Square Average Method), which was suggested as a method for reliability analysis in the previous study, is found to be suitable for the determination whether the measured thickness is acceptable or not. And, safety factors are proposed herein through the statistical analysis taking into account the components’ type.
基金Project(31200748)supported by the National Natural Science Foundation of China
文摘A finite element reconstruction algorithm for ultrasound tomography based on the Helmholtz equation in frequency domain is presented to monitor the grouting defects in reinforced concrete structures.In this algorithm,a hybrid regularizations-based iterative Newton method is implemented to provide stable inverse solutions.Furthermore,a dual mesh scheme and an adjoint method are adopted to reduce the computation cost and improve the efficiency of reconstruction.Simultaneous reconstruction of both acoustic velocity and attenuation coefficient for a reinforced concrete model is achieved with multiple frequency data.The algorithm is evaluated with numerical simulation under various practical scenarios including varied transmission/receiving modes,different noise levels,different source/detector numbers,and different contrast levels between the heterogeneity and background region.Results obtained suggest that the algorithm is insensitive to noise,and the reconstructions are quantitatively accurate in terms of the location,size and acoustic properties of the target over a range of contrast levels.
基金National Natural Science Foundation(81701891)Shiyan Municipal Leading Scientific Research Project in 2018(18Y63).
文摘Objective: High frequency ultrasound combined with policy thermal perception testing (QTT) was used to analyze the characteristics of nerve damage in diabetic peripheral neuropathy (DPN), and then provided the basis for the clinical prevention, diagnosis and treatment of DPN. Methods: A total of 110 DPN patients admitted to the hospital from December 2015 to May 2018 were selected, and the characteristics of nerve damage in diabetic peripheral neuropathy were analyzed by ultrasound and QTT. Results: In the results of QTT, the abnormal proportion of the CDT, WDT, CPT and HPT of the lower limbs in DPN's were all higher than the upper limbs;The difference of WDT and HPT in the age and course groups of patients in the upper limbs was statistically significant, the abnormal proportion of WDT and HPT in patients aged 60 years or above or with a course of 10 years or more were all above 45%, higher than those in other groups. The patients with larger mean amplitude of glycemic excursions (MAGE) were significantly higher than those with smaller MAGE, regardless of the abnormal proportion of WDT and HPT observed in upper limbs, lower limbs or upper and lower limbs;The results of ultrasonic measurement of nerve cross sectional area showed: the proportion of patients with ulnar nerve and median nerve abnormally thickened in the high age group (≥45 years) and the long course group (>10 years) was significantly higher than that in the low age group (<45 years) and the short course group (<10 years), the proportion of patients with larger MAGE with abnormal enlargement of median nerve was significantly higher than those with smaller MAGE. The thickening of ulnar nerve, median nerve and peroneal nerve was obvious in the patients of MAGE > 4 mmol/L. Conclusion: (1) The main nerve damage in DPN patients was thermal sensation damage, and the lower limb nerve was more vulnerable than the upper limb nerve. (2) The incidence of ulnar and median nerve damage was higher in patients aged 45 years and older or over 10 years of course. (3) Patients with large MAGE (> 4 mmo/L) had higher incidence of median nerve damage. The above characteristics of nerve damage can provide basis for clinical prevention, diagnosis and treatment of DPN.
文摘It is crucial to maintain wind turbine blades regularly, due to the high stress leading to defects or damage. Conventional methods require shipping the blades to a workshop for off-site inspection, which is extremely time-consuming and very costly. This work investigates the use of pulse-echo ultrasound to detect internal damages in wind turbine blades without the necessity to ship the blades off-site. A prototype 2D ultrasonic NDT (non-destructive testing) system has been developed and optimised for in-situ wind turbine blade inspection. The system is designed to be light weight so it can be easily carried by an inspector onto the wind turbine blade for in-situ inspection. It can be operated in 1D A-scan, 2D C-scan or 3D volume scan. A software system has been developed to control the automated scanning and show the damage areas in a 2D/3D map with different colours so that the inspector can easily identify the defective areas. Experiments on GFRP (glass fibre reinforced plastics) and wind turbine blades (made of GFRP) samples showed that internal defects can be detected. The main advantages of this system are fully automated 2D spatial scanning and the ability to alert the user to the damage of the inspected sample. It is intended to be used for in-situ inspection to save maintenance time and hence considered to be economically beneficial for the wind energy industry.