Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT...Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.展开更多
Background: Cervical cancer remains a significant public health concern in Macao SAR despite the implementation of a cervical cancer screening program and HPV vaccination. To improve early detection, Macao SAR introdu...Background: Cervical cancer remains a significant public health concern in Macao SAR despite the implementation of a cervical cancer screening program and HPV vaccination. To improve early detection, Macao SAR introduced HPV DNA testing alongside cytology (co-testing) as the primary screening method in 2019. This study evaluates the effectiveness of co-testing in identifying cervical precancerous lesions (CIN2+) compared to cytology alone. Methods: We conducted a retrospective analysis of women aged 30 - 65 years who participated in the routine cervical cancer screening program in Macao SAR Primary Healthcare Centers from 2019 to 2022. Data from over 70,000 women were analyzed, comparing the detection rates of CIN2+ through co-testing and cytology alone. Women with abnormal cytology or positive HPV results were referred for colposcopy. Results: The introduction of co-testing led to a significant increase in the detection of CIN2+, particularly in women with atypical squamous cells of undetermined significance (ASCUS) or negative for intraepithelial lesion or malignancy (NILM) cytology results. Between 2019 and 2022, the percentage of women with ASCUS/NILM and any high-risk HPV (hrHPV) positive who were diagnosed with CIN2+ after colposcopy were 24%, 13%, 10% and 7.5% respectively. This highlights the ability of co-testing to identify high-risk individuals who would have been missed by cytology alone. Discussion: Our findings demonstrate the effectiveness of co-testing in improving the sensitivity of cervical cancer screening in Macao SAR. The inclusion of HPV DNA testing allows for better risk stratification of women with ASCUS/NILM cytology, leading to more targeted referrals for colposcopy and timely detection of precancerous lesions. The initial high positive rate in 2019 (24%) might be attributed to the small sample size and potentially reflects a backlog of undiagnosed cases prior to co-testing implementation. Conclusion: The implementation of co-testing in Macao SAR’s cervical cancer screening program significantly improves the early detection of precancerous lesions, particularly in women with ambiguous cytology results. This proactive approach contributes to reducing cervical cancer morbidity and mortality and improving women’s health outcomes in Macao SAR.展开更多
Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe seve...Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe severely affects its pressure-holding capacity,hence the early detection of internal cracks is crucial for effective pipeline maintenance strategies.This study extends the scope of guided wave-based ultrasonic testing to detect the growth of internal cracks in a natural gas distribution PE pipe.Laboratory experiments and a finite element model were planned to study the wave-crack interaction at different stages of axially oriented internal crack growth with a piezoceramic transducer-based setup arranged in a pitch-catch configuration.Mode dispersion analysis supplemented with preliminary experiments was performed to isolate the optimal inspection frequency,leading to the selection of the T(0,1)mode at 50-kHz for the investigation.A transmission index based on the energy of the T(0,1)mode was developed to trace the extent of simulated crack growth.The findings revealed an inverse linear correlation between the transmission index and the crack depth for crack growth beyond 20%crack depth.展开更多
BACKGROUND Colorectal cancer(CRC)is one of the most common malignant tumors,and early screening is crucial to improving the survival rate of patients.The combination of colonoscopy and immune fecal occult blood detect...BACKGROUND Colorectal cancer(CRC)is one of the most common malignant tumors,and early screening is crucial to improving the survival rate of patients.The combination of colonoscopy and immune fecal occult blood detection has garnered significant attention as a novel method for CRC screening.Colonoscopy and fecal occult blood tests,when combined,can improve screening accuracy and early detection rates,thereby facilitating early intervention and treatment.However,certain risks and costs accompany it,making the establishment of a risk classification model crucial for accurate classification and management of screened subjects.AIM To evaluate the feasibility and effectiveness of colonoscopy,immune fecal occult blood test(FIT),and risk-graded screening strategies in CRC screening.METHODS Based on the randomized controlled trial of CRC screening in the population conducted by our hospital May 2020 to May 2023,participants who met the requirements were randomly assigned to a colonoscopy group,an FIT group,or a graded screening group at a ratio of 1:2:2(after risk assessment,the high-risk group received colonoscopy,the low-risk group received an FIT test,and the FITpositive group received colonoscopy).The three groups received CRC screening with different protocols,among which the colonoscopy group only received baseline screening,and the FIT group and the graded screening group received annual follow-up screening based on baseline screening.The primary outcome was the detection rate of advanced tumors,including CRC and advanced adenoma.The population participation rate,advanced tumor detection rate,and colonoscopy load of the three screening programs were compared.RESULTS A total of 19373 subjects who met the inclusion and exclusion criteria were enrolled,including 8082 males(41.7%)and 11291 females(58.3%).The mean age was 60.05±6.5 years.Among them,3883 patients were enrolled in the colonoscopy group,7793 in the FIT group,and 7697 in the graded screening group.Two rounds of follow-up screening were completed in the FIT group and the graded screening group.The graded screening group(89.2%)and the colonoscopy group(42.3%)had the lowest overall screening participation rates,while the FIT group had the highest(99.3%).The results of the intentional analysis showed that the detection rate of advanced tumors in the colonoscopy group was greater than that of the FIT group[2.76%vs 2.17%,odds ratio(OR)=1.30,95%confidence interval(CI):1.01-1.65,P=0.037].There was no significant difference in the detection rate of advanced tumors between the colonoscopy group and the graded screening group(2.76%vs 2.35%,OR=1.9,95%CI:0.93-1.51,P=0.156),as well as between the graded screening group and the FIT group(2.35%vs 2.17%,OR=1.09%,95%CI:0.88-1.34,P=0.440).The number of colonoscopy examinations required for each patient with advanced tumors was used as an index to evaluate the colonoscopy load during population screening.The graded screening group had the highest colonoscopy load(15.4 times),followed by the colonoscopy group(10.2 times),and the FIT group had the lowest(7.8 times).CONCLUSION A hierarchical screening strategy based on CRC risk assessment is feasible for screening for CRC in the population.It can be used as an effective supplement to traditional colonoscopy and FIT screening programs.展开更多
Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infectio...Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.展开更多
Gravity-1 was the world's first carrier rocket to adopt the sea-based “three vertical” testing launch mode. This article introduces the overall layout of the launch site and the workflow of rocket testing and la...Gravity-1 was the world's first carrier rocket to adopt the sea-based “three vertical” testing launch mode. This article introduces the overall layout of the launch site and the workflow of rocket testing and launch for its maiden flight mission. The process of vertical assembly, vertical testing, vertical transportation, and sea-based hot launches are explained. Additionally, it provides an outlook on the improved “three vertical” testing and launch mode for future missions, such as land-based launches, rapid launches, and remote sea launches.展开更多
As science and technology continue to develop,power equipment has become an indispensable part of industrial production and daily life.Whether it is the precise automation machinery utilized on production lines or the...As science and technology continue to develop,power equipment has become an indispensable part of industrial production and daily life.Whether it is the precise automation machinery utilized on production lines or the convenient electrical appliances found in households,their functionality relies heavily on electrical technology.Nonetheless,without stringent safety and performance assurances,these devices could potentially endanger lives and property.Thus,this paper explores the development strategy for establishing a standardized system within the electrical testing service industry,aiming to ensure safety and reliability.展开更多
This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview ...This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.展开更多
The proliferation of maliciously coded documents as file transfers increase has led to a rise in sophisticated attacks.Portable Document Format(PDF)files have emerged as a major attack vector for malware due to their ...The proliferation of maliciously coded documents as file transfers increase has led to a rise in sophisticated attacks.Portable Document Format(PDF)files have emerged as a major attack vector for malware due to their adaptability and wide usage.Detecting malware in PDF files is challenging due to its ability to include various harmful elements such as embedded scripts,exploits,and malicious URLs.This paper presents a comparative analysis of machine learning(ML)techniques,including Naive Bayes(NB),K-Nearest Neighbor(KNN),Average One Dependency Estimator(A1DE),RandomForest(RF),and SupportVectorMachine(SVM)forPDFmalware detection.The study utilizes a dataset obtained from the Canadian Institute for Cyber-security and employs different testing criteria,namely percentage splitting and 10-fold cross-validation.The performance of the techniques is evaluated using F1-score,precision,recall,and accuracy measures.The results indicate that KNNoutperforms other models,achieving an accuracy of 99.8599%using 10-fold cross-validation.The findings highlight the effectiveness of ML models in accurately detecting PDF malware and provide insights for developing robust systems to protect against malicious activities.展开更多
In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at b...In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at beamforming mode,which requires a realistic non-stationary channel environment.For the dynamic propagation emulation,an efficient closed-form probe weighting strategy minimizing the power angular spectrum(PAS)emulation errors is derived,substantially reducing the associated computational complexity.On the other hand,a novel probe selection algorithm is proposed to reproduce a more accurate fading environment.Various standard channel models and setup configurations are comprehensively simulated to validate the capacity of the proposed methods.The simulation results show that more competent active probes are selected with the proposed method compared to the conventional algorithms.Furthermore,the derived closedform probe weighting strategy offers identical accuracy to that obtained with complicated numerical optimization.Moreover,a realistic dynamic channel measured in an indoor environment is reconstructed with the developed methodologies,and 95.6%PAS similarity can be achieved with 6 active probes.The satisfactory results demonstrate that the proposed algorithms are suitable for arbitrary channel emulation.展开更多
The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an ...The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear models.The atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N.展开更多
The tensile strength at the rock-concrete interface is one of the crucial factors controlling the failure mechanisms of structures,such as concrete gravity dams.Despite the critical importance of the failure mechanism...The tensile strength at the rock-concrete interface is one of the crucial factors controlling the failure mechanisms of structures,such as concrete gravity dams.Despite the critical importance of the failure mechanism and tensile strength of rock-concrete interfaces,understanding of these factors remains very limited.This study investigated the tensile strength and fracturing processes at rock-mortar interfaces subjected to direct and indirect tensile loadings.Digital image correlation(DIC)and acoustic emission(AE)techniques were used to monitor the failure mechanisms of specimens subjected to direct tension and indirect loading(Brazilian tests).The results indicated that the direct tensile strength of the rock-mortar specimens was lower than their indirect tensile strength,with a direct/indirect tensile strength ratio of 65%.DIC strain field data and moment tensor inversions(MTI)of AE events indicated that a significant number of shear microcracks occurred in the specimens subjected to the Brazilian test.The presence of these shear microcracks,which require more energy to break,resulted in a higher tensile strength during the Brazilian tests.In contrast,microcracks were predominantly tensile in specimens subjected to direct tension,leading to a lower tensile strength.Spatiotemporal monitoring of the cracking processes in the rock-mortar interfaces revealed that they show AE precursors before failure under the Brazilian test,whereas they show a minimal number of AE events before failure under direct tension.Due to different microcracking mechanisms,specimens tested under Brazilian tests showed lower roughness with flatter fracture surfaces than those tested under direct tension with jagged and rough fracture surfaces.The results of this study shed light on better understanding the micromechanics of damage in the rock-concrete interfaces for a safer design of engineering structures.展开更多
Colorectal cancer(CRC)screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers.Over the years,screening,particularly in those settings where it is well orga...Colorectal cancer(CRC)screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers.Over the years,screening,particularly in those settings where it is well organized,has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them.Despite considerable advancements in screening technologies and strategies,the effectiveness of CRC screening programs remains less than optimal.This paper examined the multifaceted reasons behind the persistent lack of effect-iveness in CRC screening initiatives.Through a critical analysis of current methodologies,technological limitations,patient-related factors,and systemic challenges,we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates.While acknowledging the ad-vancements that have improved aspects of screening,we emphasized the necessity of addressing the identified barriers comprehensively.This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease.Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage.Spending more sooner can mean saving money later.展开更多
BACKGROUND Several genetic testing techniques have been recommended as a first-tier diagnostic tool in clinical practice for diagnosing autism spectrum disorder(ASD).However,the actual usage rate varies dramatically.T...BACKGROUND Several genetic testing techniques have been recommended as a first-tier diagnostic tool in clinical practice for diagnosing autism spectrum disorder(ASD).However,the actual usage rate varies dramatically.This is due to various reasons,including knowledge and attitudes of caregivers,patients,and health providers toward genetic testing.Several studies have therefore been conducted worldwide to investigate the knowledge,experiences,and attitudes toward genetic testing among caregivers of children with ASD,adolescent and adult ASD patients,and health providers who provide medical services for them.However,no systematic review has been done.AIM To systematically review research on knowledge,experiences,and attitudes towards genetic testing among caregivers of children with ASD,adolescent and adult ASD patients,and health providers.METHODS We followed the Preferred Reporting Items for Systematic Reviews and Metaanalyses guidelines and searched the literature in three English language databases(PubMed,Web of Science,and PsychInfo)and two Chinese databases(CNKI and Wanfang).Searched literature was screened independently by two reviewers and discussed when inconsistency existed.Information on characteristics of the study,characteristics of participants,and main findings regarding knowledge,experience,and attitudes of caregivers of children with ASD,adolescent and adult ASD patients,and health providers concerning ASD genetic testing were extracted from included papers into a charting form for analysis.RESULTS We included 30 studies published between 2012 and 2022 and conducted in 9 countries.Most of the studies(n=29)investigated caregivers of children with ASD,one study also included adolescent and adult patients,and two covered health providers.Most(51.0%-100%)of the caregivers/patients knew there was a genetic cause for ASD and 17.0%to 78.1%were aware of ASD genetic testing.However,they lacked full understanding of genetic testing.They acquired relevant and necessary information from physicians,the internet,ASD organizations,and other caregivers.Between 9.1%to 72.7%of caregivers in different studies were referred for genetic testing,and between 17.4%to 61.7%actually obtained genetic testing.Most caregivers agreed there are potential benefits following genetic testing,including benefits for children,families,and others.However,two studies compared perceived pre-test and post-test benefits with conflicting findings.Caregivers concerns included high costs,unhelpful results,negative influences(e.g.,causing family conflicts,causing stress/risk/pain to children etc.)prevented some caregivers from using genetic testing.Nevertheless,46.7%to 95.0%caregivers without previous genetic testing experience intended to obtain it in the future,and 50.5%to 59.6%of parents previously obtaining genetic testing would recommend it to other parents.In a single study of child and adolescent psychiatrists,54.9%of respondents had ordered ASD genetic testing for their patients in the prior 12 mo,which was associated with greater knowledge of genetic testing.CONCLUSION Most caregivers are willing to learn about and use genetic testing.However,the review showed their current knowledge is limited and usage rates varied widely in different studies.展开更多
In this study,an X-band standing-wave biperiodic linear accelerator was developed for medical radiotherapy that can accel-erate electrons to 9 MeV using a 2.4-MW klystron.The structure works atπ/2 mode and adopts mag...In this study,an X-band standing-wave biperiodic linear accelerator was developed for medical radiotherapy that can accel-erate electrons to 9 MeV using a 2.4-MW klystron.The structure works atπ/2 mode and adopts magnetic coupling between cavities,generating the appropriate adjacent mode separation of 10 MHz.The accelerator is less than 600-mm long and constitutes four bunching cells and 29 normal cells.Geometry optimizations,full-scale radiofrequency(RF)simulations,and beam dynamics calculations were performed.The accelerator was fabricated and examined using a low-power RF test.The cold test results showed a good agreement with the simulation and actual measurement results.In the high-power RF test,the output beam current,energy spectrum,capture ratio,and spot size at the accelerator exit were measured.With the input power of 2.4 MW,the pulse current was 100 mA,and the output spot root-mean-square radius was approximately 0.5 mm.The output kinetic energy was 9.04 MeV with the spectral FWHM of 3.5%,demonstrating the good performance of this accelerator.展开更多
Intimate Partner Violence (IPV) is a form of Gender Base Violence (GBV) where an intimate partner perpetrates violence. In the HIV care continua which has the aim of achieving epidemic control based on the goals defin...Intimate Partner Violence (IPV) is a form of Gender Base Violence (GBV) where an intimate partner perpetrates violence. In the HIV care continua which has the aim of achieving epidemic control based on the goals defined by UNAIDS, 95% of people living with HIV (PLHIV) have to know their HIV status, 95% initiated ARV treatment and 95% are virally suppressed in order to achieve epidemic control. One of the evidence-based strategies used for achieving an optimal number of PLHIV who know their HIV status is the Index Case Testing Strategy (ICT). While the ICT strategy helps the achievement of epidemic control, its implementation increases the incidence of IPV among either serodiscordant or concordant couples. Tackling information about IPV is very sensitive. A review of the literature on the management of HIV patient information has shown that shifting from paper-based management of HIV patient information to computerized Electronic Medical Records (EMR) systems, using software such as OPEN MRS has significantly improved the management of HIV patient information with high-level confidentiality of patient information. The reviews showed that the EMR systems put in place to manage HIV patient information need to integrate the stages used for the management of IPV among PLHIV.展开更多
基金supported by the National Research Foundation of Korea(No.2021R1A2B5B03001691).
文摘Point-of-care testing(POCT)is the practice of diagnosing and monitoring diseases where the patient is located,as opposed to traditional treatment conducted solely in a medical laboratory or other clinical setting.POCT has been less common in the recent past due to a lack of portable medical devices capable of facilitating effective medical testing.However,recent growth has occurred in this field due to advances in diagnostic technologies,device miniaturization,and progress in wearable electronics.Among these developments,electrochemical sensors have attracted interest in the POCT field due to their high sensitivity,compact size,and affordability.They are used in various applications,from disease diagnosis to health status monitoring.In this paper we explore recent advancements in electrochemical sensors,the methods of fabricating them,and the various types of sensing mechanisms that can be used.Furthermore,we delve into methods for immobilizing specific biorecognition elements,including enzymes,antibodies,and aptamers,onto electrode surfaces and how these sensors are used in real-world POCT settings.
文摘Background: Cervical cancer remains a significant public health concern in Macao SAR despite the implementation of a cervical cancer screening program and HPV vaccination. To improve early detection, Macao SAR introduced HPV DNA testing alongside cytology (co-testing) as the primary screening method in 2019. This study evaluates the effectiveness of co-testing in identifying cervical precancerous lesions (CIN2+) compared to cytology alone. Methods: We conducted a retrospective analysis of women aged 30 - 65 years who participated in the routine cervical cancer screening program in Macao SAR Primary Healthcare Centers from 2019 to 2022. Data from over 70,000 women were analyzed, comparing the detection rates of CIN2+ through co-testing and cytology alone. Women with abnormal cytology or positive HPV results were referred for colposcopy. Results: The introduction of co-testing led to a significant increase in the detection of CIN2+, particularly in women with atypical squamous cells of undetermined significance (ASCUS) or negative for intraepithelial lesion or malignancy (NILM) cytology results. Between 2019 and 2022, the percentage of women with ASCUS/NILM and any high-risk HPV (hrHPV) positive who were diagnosed with CIN2+ after colposcopy were 24%, 13%, 10% and 7.5% respectively. This highlights the ability of co-testing to identify high-risk individuals who would have been missed by cytology alone. Discussion: Our findings demonstrate the effectiveness of co-testing in improving the sensitivity of cervical cancer screening in Macao SAR. The inclusion of HPV DNA testing allows for better risk stratification of women with ASCUS/NILM cytology, leading to more targeted referrals for colposcopy and timely detection of precancerous lesions. The initial high positive rate in 2019 (24%) might be attributed to the small sample size and potentially reflects a backlog of undiagnosed cases prior to co-testing implementation. Conclusion: The implementation of co-testing in Macao SAR’s cervical cancer screening program significantly improves the early detection of precancerous lesions, particularly in women with ambiguous cytology results. This proactive approach contributes to reducing cervical cancer morbidity and mortality and improving women’s health outcomes in Macao SAR.
基金the financial support provided by USDOT Pipeline and Hazardous Materials Safety Administration (PHMSA)through the Competitive Academic Agreement Program (CAAP)。
文摘Despite the success of guided wave ultrasonic inspection for internal defect detection in steel pipes,its application on polyethylene(PE)pipe remains relatively unexplored.The growth of internal cracks in PE pipe severely affects its pressure-holding capacity,hence the early detection of internal cracks is crucial for effective pipeline maintenance strategies.This study extends the scope of guided wave-based ultrasonic testing to detect the growth of internal cracks in a natural gas distribution PE pipe.Laboratory experiments and a finite element model were planned to study the wave-crack interaction at different stages of axially oriented internal crack growth with a piezoceramic transducer-based setup arranged in a pitch-catch configuration.Mode dispersion analysis supplemented with preliminary experiments was performed to isolate the optimal inspection frequency,leading to the selection of the T(0,1)mode at 50-kHz for the investigation.A transmission index based on the energy of the T(0,1)mode was developed to trace the extent of simulated crack growth.The findings revealed an inverse linear correlation between the transmission index and the crack depth for crack growth beyond 20%crack depth.
文摘BACKGROUND Colorectal cancer(CRC)is one of the most common malignant tumors,and early screening is crucial to improving the survival rate of patients.The combination of colonoscopy and immune fecal occult blood detection has garnered significant attention as a novel method for CRC screening.Colonoscopy and fecal occult blood tests,when combined,can improve screening accuracy and early detection rates,thereby facilitating early intervention and treatment.However,certain risks and costs accompany it,making the establishment of a risk classification model crucial for accurate classification and management of screened subjects.AIM To evaluate the feasibility and effectiveness of colonoscopy,immune fecal occult blood test(FIT),and risk-graded screening strategies in CRC screening.METHODS Based on the randomized controlled trial of CRC screening in the population conducted by our hospital May 2020 to May 2023,participants who met the requirements were randomly assigned to a colonoscopy group,an FIT group,or a graded screening group at a ratio of 1:2:2(after risk assessment,the high-risk group received colonoscopy,the low-risk group received an FIT test,and the FITpositive group received colonoscopy).The three groups received CRC screening with different protocols,among which the colonoscopy group only received baseline screening,and the FIT group and the graded screening group received annual follow-up screening based on baseline screening.The primary outcome was the detection rate of advanced tumors,including CRC and advanced adenoma.The population participation rate,advanced tumor detection rate,and colonoscopy load of the three screening programs were compared.RESULTS A total of 19373 subjects who met the inclusion and exclusion criteria were enrolled,including 8082 males(41.7%)and 11291 females(58.3%).The mean age was 60.05±6.5 years.Among them,3883 patients were enrolled in the colonoscopy group,7793 in the FIT group,and 7697 in the graded screening group.Two rounds of follow-up screening were completed in the FIT group and the graded screening group.The graded screening group(89.2%)and the colonoscopy group(42.3%)had the lowest overall screening participation rates,while the FIT group had the highest(99.3%).The results of the intentional analysis showed that the detection rate of advanced tumors in the colonoscopy group was greater than that of the FIT group[2.76%vs 2.17%,odds ratio(OR)=1.30,95%confidence interval(CI):1.01-1.65,P=0.037].There was no significant difference in the detection rate of advanced tumors between the colonoscopy group and the graded screening group(2.76%vs 2.35%,OR=1.9,95%CI:0.93-1.51,P=0.156),as well as between the graded screening group and the FIT group(2.35%vs 2.17%,OR=1.09%,95%CI:0.88-1.34,P=0.440).The number of colonoscopy examinations required for each patient with advanced tumors was used as an index to evaluate the colonoscopy load during population screening.The graded screening group had the highest colonoscopy load(15.4 times),followed by the colonoscopy group(10.2 times),and the FIT group had the lowest(7.8 times).CONCLUSION A hierarchical screening strategy based on CRC risk assessment is feasible for screening for CRC in the population.It can be used as an effective supplement to traditional colonoscopy and FIT screening programs.
文摘Hepatitis D virus(HDV)can infect HBsAg-positive individuals,causing rapid fibrosis progression,early decompensation,increased hepatocellular carcinoma risk,and higher mortality than hepatitis B virus(HBV)mono-infection.Most countries lack high-quality HDV prevalence data,and the collection techniques employed often bias published data.In recent meta-analyses,HDV prevalence in HBsAg-positive patients reaches 5%-15%and is even significantly higher in endemic areas.Since HBV vaccination programs were implemented,HDV prevalence has decreased among younger populations.However,owing to immigrant influx,it has increased in some Western countries.The current practice of HDV screening in HBsAg-positive individuals is stepwise,based on physician’s discretion,and limited to at-risk populations and may require numerous visits.Double reflex testing,which includes anti-HDV testing in all HBsAg-positive individuals and then HDV RNA testing for anti-HDV-positive ones,is uncommon.Reflex testing can identify more HDV infection cases and link identified patients to further care and follow-up.Moreover,laboratory-based double reflex screening is less biased than physician-led testing.Therefore,health-care providers should learn about reflex testing,and federal and provincial hepatitis control programs should implement laboratory-based double reflex testing to obtain reliable HDV prevalence estimates.The test’s cost-effectiveness depends on the number of HBV-positive patients screened to identify one HDV-positive patient.Such testing may be viable in areas with low HBsAg but high HDV prevalence.However,its economic impact on areas with low HDV prevalence needs further study.
文摘Gravity-1 was the world's first carrier rocket to adopt the sea-based “three vertical” testing launch mode. This article introduces the overall layout of the launch site and the workflow of rocket testing and launch for its maiden flight mission. The process of vertical assembly, vertical testing, vertical transportation, and sea-based hot launches are explained. Additionally, it provides an outlook on the improved “three vertical” testing and launch mode for future missions, such as land-based launches, rapid launches, and remote sea launches.
基金Tianshui City Science and Technology Support Plan Project:2023-FZJHK-2813。
文摘As science and technology continue to develop,power equipment has become an indispensable part of industrial production and daily life.Whether it is the precise automation machinery utilized on production lines or the convenient electrical appliances found in households,their functionality relies heavily on electrical technology.Nonetheless,without stringent safety and performance assurances,these devices could potentially endanger lives and property.Thus,this paper explores the development strategy for establishing a standardized system within the electrical testing service industry,aiming to ensure safety and reliability.
文摘This article takes the actual construction project of a certain concrete bridge project as an example to analyze the application of acoustic non-destructive testing technology in its detection.It includes an overview of a certain bridge construction project studied and acoustic non-destructive testing technology and the application of acoustic non-destructive testing technology in actual testing.This analysis hopes to provide some guidelines for acoustic non-destructive testing of modern concrete bridge projects.
文摘The proliferation of maliciously coded documents as file transfers increase has led to a rise in sophisticated attacks.Portable Document Format(PDF)files have emerged as a major attack vector for malware due to their adaptability and wide usage.Detecting malware in PDF files is challenging due to its ability to include various harmful elements such as embedded scripts,exploits,and malicious URLs.This paper presents a comparative analysis of machine learning(ML)techniques,including Naive Bayes(NB),K-Nearest Neighbor(KNN),Average One Dependency Estimator(A1DE),RandomForest(RF),and SupportVectorMachine(SVM)forPDFmalware detection.The study utilizes a dataset obtained from the Canadian Institute for Cyber-security and employs different testing criteria,namely percentage splitting and 10-fold cross-validation.The performance of the techniques is evaluated using F1-score,precision,recall,and accuracy measures.The results indicate that KNNoutperforms other models,achieving an accuracy of 99.8599%using 10-fold cross-validation.The findings highlight the effectiveness of ML models in accurately detecting PDF malware and provide insights for developing robust systems to protect against malicious activities.
基金supported by National Natural Science Foundation of China(No.62090015,No.61821001)BUPT Excellent Ph.D.Students Foundation under Grant(CX2021216)。
文摘In this article,novel emulation strategies for the sectored multiple probe anechoic chamber(SMPAC)are proposed to enable the reliable evaluation of the massive multiple-input multiple-output(MIMO)device operating at beamforming mode,which requires a realistic non-stationary channel environment.For the dynamic propagation emulation,an efficient closed-form probe weighting strategy minimizing the power angular spectrum(PAS)emulation errors is derived,substantially reducing the associated computational complexity.On the other hand,a novel probe selection algorithm is proposed to reproduce a more accurate fading environment.Various standard channel models and setup configurations are comprehensively simulated to validate the capacity of the proposed methods.The simulation results show that more competent active probes are selected with the proposed method compared to the conventional algorithms.Furthermore,the derived closedform probe weighting strategy offers identical accuracy to that obtained with complicated numerical optimization.Moreover,a realistic dynamic channel measured in an indoor environment is reconstructed with the developed methodologies,and 95.6%PAS similarity can be achieved with 6 active probes.The satisfactory results demonstrate that the proposed algorithms are suitable for arbitrary channel emulation.
基金This work was supported by the National Natural Science Foundation of China(Nos.12335007,11835001,11921006,12035001 and 12205340)the State Key Laboratory of Nuclear Physics and Technology,Peking University(No.NPT2020KFY13)Gansu Natural Science Foundation(No.22JR5RA123).
文摘The beyond-dripline oxygen isotopes^(27,28)O were recently observed at RIKEN,and were found to be unbound decaying into^(24)O by emitting neutrons.The unbound feature of the heaviest oxygen isotope,^(28)O,provides an excellent test for stateof-the-art nuclear models.The atomic nucleus is a self-organized quantum manybody system comprising specific numbers of protons Z and neutrons N.
文摘The tensile strength at the rock-concrete interface is one of the crucial factors controlling the failure mechanisms of structures,such as concrete gravity dams.Despite the critical importance of the failure mechanism and tensile strength of rock-concrete interfaces,understanding of these factors remains very limited.This study investigated the tensile strength and fracturing processes at rock-mortar interfaces subjected to direct and indirect tensile loadings.Digital image correlation(DIC)and acoustic emission(AE)techniques were used to monitor the failure mechanisms of specimens subjected to direct tension and indirect loading(Brazilian tests).The results indicated that the direct tensile strength of the rock-mortar specimens was lower than their indirect tensile strength,with a direct/indirect tensile strength ratio of 65%.DIC strain field data and moment tensor inversions(MTI)of AE events indicated that a significant number of shear microcracks occurred in the specimens subjected to the Brazilian test.The presence of these shear microcracks,which require more energy to break,resulted in a higher tensile strength during the Brazilian tests.In contrast,microcracks were predominantly tensile in specimens subjected to direct tension,leading to a lower tensile strength.Spatiotemporal monitoring of the cracking processes in the rock-mortar interfaces revealed that they show AE precursors before failure under the Brazilian test,whereas they show a minimal number of AE events before failure under direct tension.Due to different microcracking mechanisms,specimens tested under Brazilian tests showed lower roughness with flatter fracture surfaces than those tested under direct tension with jagged and rough fracture surfaces.The results of this study shed light on better understanding the micromechanics of damage in the rock-concrete interfaces for a safer design of engineering structures.
文摘Colorectal cancer(CRC)screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers.Over the years,screening,particularly in those settings where it is well organized,has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them.Despite considerable advancements in screening technologies and strategies,the effectiveness of CRC screening programs remains less than optimal.This paper examined the multifaceted reasons behind the persistent lack of effect-iveness in CRC screening initiatives.Through a critical analysis of current methodologies,technological limitations,patient-related factors,and systemic challenges,we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates.While acknowledging the ad-vancements that have improved aspects of screening,we emphasized the necessity of addressing the identified barriers comprehensively.This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease.Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage.Spending more sooner can mean saving money later.
基金the National Natural Science Foundation of China,No.81920108018(Li T and Sham P),No.82001409(Zhang YM)the Key R&D Program of Zhejiang,No.2022C03096(Li T)Project for Hangzhou Medical Disciplines of Excellence。
文摘BACKGROUND Several genetic testing techniques have been recommended as a first-tier diagnostic tool in clinical practice for diagnosing autism spectrum disorder(ASD).However,the actual usage rate varies dramatically.This is due to various reasons,including knowledge and attitudes of caregivers,patients,and health providers toward genetic testing.Several studies have therefore been conducted worldwide to investigate the knowledge,experiences,and attitudes toward genetic testing among caregivers of children with ASD,adolescent and adult ASD patients,and health providers who provide medical services for them.However,no systematic review has been done.AIM To systematically review research on knowledge,experiences,and attitudes towards genetic testing among caregivers of children with ASD,adolescent and adult ASD patients,and health providers.METHODS We followed the Preferred Reporting Items for Systematic Reviews and Metaanalyses guidelines and searched the literature in three English language databases(PubMed,Web of Science,and PsychInfo)and two Chinese databases(CNKI and Wanfang).Searched literature was screened independently by two reviewers and discussed when inconsistency existed.Information on characteristics of the study,characteristics of participants,and main findings regarding knowledge,experience,and attitudes of caregivers of children with ASD,adolescent and adult ASD patients,and health providers concerning ASD genetic testing were extracted from included papers into a charting form for analysis.RESULTS We included 30 studies published between 2012 and 2022 and conducted in 9 countries.Most of the studies(n=29)investigated caregivers of children with ASD,one study also included adolescent and adult patients,and two covered health providers.Most(51.0%-100%)of the caregivers/patients knew there was a genetic cause for ASD and 17.0%to 78.1%were aware of ASD genetic testing.However,they lacked full understanding of genetic testing.They acquired relevant and necessary information from physicians,the internet,ASD organizations,and other caregivers.Between 9.1%to 72.7%of caregivers in different studies were referred for genetic testing,and between 17.4%to 61.7%actually obtained genetic testing.Most caregivers agreed there are potential benefits following genetic testing,including benefits for children,families,and others.However,two studies compared perceived pre-test and post-test benefits with conflicting findings.Caregivers concerns included high costs,unhelpful results,negative influences(e.g.,causing family conflicts,causing stress/risk/pain to children etc.)prevented some caregivers from using genetic testing.Nevertheless,46.7%to 95.0%caregivers without previous genetic testing experience intended to obtain it in the future,and 50.5%to 59.6%of parents previously obtaining genetic testing would recommend it to other parents.In a single study of child and adolescent psychiatrists,54.9%of respondents had ordered ASD genetic testing for their patients in the prior 12 mo,which was associated with greater knowledge of genetic testing.CONCLUSION Most caregivers are willing to learn about and use genetic testing.However,the review showed their current knowledge is limited and usage rates varied widely in different studies.
基金the Key R&D Project of the Ministry of Science and Technology of China(No.2022YFC2402300).
文摘In this study,an X-band standing-wave biperiodic linear accelerator was developed for medical radiotherapy that can accel-erate electrons to 9 MeV using a 2.4-MW klystron.The structure works atπ/2 mode and adopts magnetic coupling between cavities,generating the appropriate adjacent mode separation of 10 MHz.The accelerator is less than 600-mm long and constitutes four bunching cells and 29 normal cells.Geometry optimizations,full-scale radiofrequency(RF)simulations,and beam dynamics calculations were performed.The accelerator was fabricated and examined using a low-power RF test.The cold test results showed a good agreement with the simulation and actual measurement results.In the high-power RF test,the output beam current,energy spectrum,capture ratio,and spot size at the accelerator exit were measured.With the input power of 2.4 MW,the pulse current was 100 mA,and the output spot root-mean-square radius was approximately 0.5 mm.The output kinetic energy was 9.04 MeV with the spectral FWHM of 3.5%,demonstrating the good performance of this accelerator.
文摘Intimate Partner Violence (IPV) is a form of Gender Base Violence (GBV) where an intimate partner perpetrates violence. In the HIV care continua which has the aim of achieving epidemic control based on the goals defined by UNAIDS, 95% of people living with HIV (PLHIV) have to know their HIV status, 95% initiated ARV treatment and 95% are virally suppressed in order to achieve epidemic control. One of the evidence-based strategies used for achieving an optimal number of PLHIV who know their HIV status is the Index Case Testing Strategy (ICT). While the ICT strategy helps the achievement of epidemic control, its implementation increases the incidence of IPV among either serodiscordant or concordant couples. Tackling information about IPV is very sensitive. A review of the literature on the management of HIV patient information has shown that shifting from paper-based management of HIV patient information to computerized Electronic Medical Records (EMR) systems, using software such as OPEN MRS has significantly improved the management of HIV patient information with high-level confidentiality of patient information. The reviews showed that the EMR systems put in place to manage HIV patient information need to integrate the stages used for the management of IPV among PLHIV.