Ported wall extensions are important hydraulic structures used to reduce crosscurrents in upper approaches to locks.The effect of such extensions located upstream of a solid guard wall on flow characteristics depends ...Ported wall extensions are important hydraulic structures used to reduce crosscurrents in upper approaches to locks.The effect of such extensions located upstream of a solid guard wall on flow characteristics depends on many factors,including geometric and hydraulic parameters.In this study,the hydraulic performance of ported wall extensions was experimentally investigated in terms of the permeability coefficient,expanding angle,extension length,and flow depth.The results demonstrate that the dimensionless maximum transverse velocity is closely related to the permeability coefficient,expanding angle,and flow depth.By contrast,the dimensionless eddy length mainly depends on the permeability coefficient,expanding angle,and extension length.Furthermore,the optimum permeability coefficient increases with the expanding angle or flow depth,and it is approximately constant for different extension lengths.These results have the potential to provide direct guidance for the design of effective ported wall extensions in upper approaches to locks.展开更多
A series of polymer- supported Pd -Fe2O3 composite catalysts were prepared and their hydrogenation property mas investigated. It was found that the above catalysts have good catalytic hydrogenation activity for carbon...A series of polymer- supported Pd -Fe2O3 composite catalysts were prepared and their hydrogenation property mas investigated. It was found that the above catalysts have good catalytic hydrogenation activity for carbon - carbon double bonds systems and reusability. Furthermore, XPS and IR spectra shouted that active component in the composite catalysts is atomic Pd(0). An addition of a small amount of Fe2O3 has a promotive action upon hydrogenation activity of the catalysts, which indicated that there are some strong interactions (electron transfer) between Pd(0) and Fe(Ⅲ) species. Based on these results, a possible catalytic hydrogenation mechanism was also suggested.展开更多
In this issue of the Journal of Geriatric Cardiology,Yang et al.1 studied the effects of arotinolol, a beta-blocker (BB), on the right ventricular (RV) function.……
Purpose: To report a novel technique of laparoscopic 10 mm Single Port Access IntraPeritoneal Onlay Mesh (SPA-IPOM) using bioresorbable composite mesh fixed with Endoclose suture (percutaneous subcutaneous suture) in ...Purpose: To report a novel technique of laparoscopic 10 mm Single Port Access IntraPeritoneal Onlay Mesh (SPA-IPOM) using bioresorbable composite mesh fixed with Endoclose suture (percutaneous subcutaneous suture) in 3 cases of bilateral inguinal hernia. Methods: Laparoscopic SPA-IPOM is done through a 10 mm trocar with one 10 mm instrument that has 5 mm optical lens and 5 mm channel for grasper. After inserting 10 mm trocar at umbilicus using semi-open technique, intraperitoneal anatomical landmark of inguinal her-nia is identified. A 10 × 15 cm pre-tied bioresorbable composite mesh is then placed to cover hernia defect and all three potential area of indirect, direct and femoral hernia. Using Endoclose? needle, each pair of pre-tied sutures is retrieved percutaneously through a needle wound and extracorporeal tied with knot in subcutaneous space. After the upper half of mesh is sutured to the posterior surface of abdominal wall, the lower half of mesh is fixed by hernia tacker to Symphysis Pubis, Cooper Ligament and Iliopubic tract. Re-sults: Three men, average 48 year olds were operated by laparoscopic 10 mm SPA-IPOM for bilateral in-guinal hernia repair using bioresorbable composite mesh. Average operative time was 36 minutes. No imme-diate complication. All patients were discharge on the 2nd post-operative day and average 6 months follow up has no recurrence. Conclusions: Laparoscopic SPA-IPOM is an optional operation and is much easier to be performed. Benefits include operative time saving, cosmesis, early discharge and early return to work. Bio-resorbable composite mesh prevents bowel adhesion, however, is much more expensive. Long term follow up study for complications and recurrence is needed.展开更多
Extending the operational range of centrifugal compressors is strategically vital for turbocharging internal combustion engines,particularly in enhancing efficiency and expanding operational capabilities.This extensio...Extending the operational range of centrifugal compressors is strategically vital for turbocharging internal combustion engines,particularly in enhancing efficiency and expanding operational capabilities.This extension is crucial for reducing environmental impact by enabling engines to perform more efficiently under a wider range of conditions.In the transition from conventional thermal reciprocating engines,fuel cells,especially proton exchange membrane fuel cells(PEMFCs),are emerging as strong alternatives.In automotive applications,PEMFCs often require turbocharging to supply compressed air to the cathode system of the fuel cell stack.This integration is essential for utilizing the heat from the fuel cell's waste products,thereby improving overall system efficiency.Ongoing research and development in radial turbomachinery are critical for optimizing the performance of these propulsion systems.Specifically,adapting turbocharger designs to meet the unique requirements of fuel cell systems and extending their operational range are essential tasks.Using a simplified CFD model,the impact of a ported shroud on compressor performance and range extension has been investigated.Flow structure analysis identified that the primary role of the ported shroud is to modify the relative flow angle on the rotor at the highest span channel.Additionally,a simplified analytical model was developed to quantify the effectiveness of different ported shroud geometries on the compressor by examining changes in tangential velocity after mixing with the flow from the cavity.展开更多
Ⅰ. INTRODUCTION The classical Kirchhoff’s theory of thin plates without taking the effect of transverse shear deformation into account can give exact enough results when the thickness h of a plate is small in compar...Ⅰ. INTRODUCTION The classical Kirchhoff’s theory of thin plates without taking the effect of transverse shear deformation into account can give exact enough results when the thickness h of a plate is small in comparison with the other characteristic sizes. How-展开更多
Port Reporter是微软出的一个小工具软件，别看它个头小，功能却非常强大。它可以扫描计算机目前正在打开的端口，并且可以跟踪记录这些端口的变化过程，即使使用不同的账号登录计算机，Port Reporter也能记录所有使用者的账号和登录后...Port Reporter是微软出的一个小工具软件，别看它个头小，功能却非常强大。它可以扫描计算机目前正在打开的端口，并且可以跟踪记录这些端口的变化过程，即使使用不同的账号登录计算机，Port Reporter也能记录所有使用者的账号和登录后所进行的网络操作。其日志是以文本的格式保存，用记事本就可以找开查看。展开更多
The Ministry of Environmental Protection’s environmentcomplaint office said on December 21 st,2009that more than half of the complaints it received viapublic hotline in November 2009 were related tochemical,non-metal...The Ministry of Environmental Protection’s environmentcomplaint office said on December 21 st,2009that more than half of the complaints it received viapublic hotline in November 2009 were related tochemical,non-metal mining process,metal refining andpaper making industries.And chemical sector is stillthe key reported target,occupying 28% of the total.InNovember,the reports on paper making and its related,and power and heat producers rose.The local environ-展开更多
Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition wi...Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition with Random Forest algorithm to investigate ozone dynamics and formation regimes in a coastal area of China.During the period of 2017–2022,significant inter-annual fluctuations emerged,with peaks in mid-2017 attributed to volatile organic compounds(VOCs),and in late-2019 influenced by air temperature.Multifaceted periodicities(daily,weekly,holiday,and yearly)in ozone were revealed,elucidating substantial influences of daily and yearly components on ozone periodicity.A VOC-sensitive ozone formation regime was identified,characterized by lower VOCs/NO_(x) ratios(average=0.88)and significant positive correlations between ozone and VOCs.This interplay manifested in elevated ozone duringweekends,holidays,and pandemic lockdowns.Key variables influencing ozone across diverse timescaleswere uncovered,with solar radiation and temperature driving daily and yearly ozone variations,respectively.Precursor substances,particularly VOCs,significantly shaped weekly/holiday patterns and long-term trends of ozone.Specifically,acetone,ethane,hexanal,and toluene had a notable impact on the multi-year ozone trend,emphasizing the urgency of VOC regulation.Furthermore,our observations indicated that NO_(x) primarily drived the stochastic variations in ozone,a distinguishing characteristic of regions with heavy traffic.This research provides novel insights into ozone dynamics in coastal urban areas and highlights the importance of integrating statistical and machinelearning methods in atmospheric pollution studies,with implications for targeted mitigation strategies beyond this specific region and pollutant.展开更多
Ports,the core hub of global supply chains,serve as vital links in the economic and trade exchanges among countries.Efficient,safe,green and smart ports are essential for the smooth operation of global trade.Recently,...Ports,the core hub of global supply chains,serve as vital links in the economic and trade exchanges among countries.Efficient,safe,green and smart ports are essential for the smooth operation of global trade.Recently,ISO established ISO/TC 8/SC 27,Ports and terminals,the secretariat of which is held by China.This is a big breakthrough of China’s participation in the international standardization activities in the area of transportation.展开更多
With the commissioning of Phase$,the port of Kribi is emerging as an important maritime transport hub in Central Africa With a 715-metre quay and a draught of 16 metres,the Autonomous Port of Kribi(APK)stands as one o...With the commissioning of Phase$,the port of Kribi is emerging as an important maritime transport hub in Central Africa With a 715-metre quay and a draught of 16 metres,the Autonomous Port of Kribi(APK)stands as one of Africa’s most strategically significant deep-water ports.Situated on Cameroon’s Atlantic coast,it o!ers direct access to international shipping lanes and is designed to handle large-capacity vessels that many regional ports cannot accommodate.展开更多
Ghana’s Tema Port marked a historic milestone on 16 January 2024 with the arrival of Maersk Edirne,a 13,676-TEU container vessel-one of the largest of its kind globally-as part of Maersk’s newly launched Far East-We...Ghana’s Tema Port marked a historic milestone on 16 January 2024 with the arrival of Maersk Edirne,a 13,676-TEU container vessel-one of the largest of its kind globally-as part of Maersk’s newly launched Far East-West Africa express service.展开更多
The efficient transportation of goods is vital for the economic growth of communities,making developing and maintaining seaport infrastructure an essential component of the marine transportation system.Given their geo...The efficient transportation of goods is vital for the economic growth of communities,making developing and maintaining seaport infrastructure an essential component of the marine transportation system.Given their geographic locations,ports are consistently at risk from natural hazards,making the resilience of port infrastructure an essential goal.Despite considerable progress in resilience research,there remains a gap in methods tailored explicitly to assessing port resilience,particularly under extreme wind events.Current approaches often do not capture the full complexity of port systems,as they tend to focus on isolated aspects,such as structural resilience.This paper introduces the PORT Resilience Framework,addressing these gaps by evaluating resilience through a comprehensive list of indicators gathered from various legitimate sources.The indicators are then organized under four comprehensive resilience dimensions:Physical Infrastructure,ICT(i.e.,Information and Communication Technology)and Equipment;Organization and Business Management;Resources and Economic Development;and Territory,Environment,and Stakeholders.This classification is summarized under the acronym"PORT."This paper also introduces a method for aggregating resilience indicators by considering their performance before and after a specific hazard,transforming the data into a quantifiable Loss of Resilience index.The approach is applied to a case study,assessing the resilience of a real Terminal against wind action using real data sourced from the port management.The case study analysis revealed that human resources and quay operations were the most critical factors affecting recovery,with insufficient staffing leading to prolonged recovery periods.The study further demonstrated that post-disruption activity surges,captured by different serviceability function methodologies,often created operational bottlenecks,challenging the port's overall recovery.展开更多
BACKGROUND Arm-implanted totally implantable venous access devices(peripherally inserted central catheter port)have become an important vascular access for colorectal cancer chemotherapy,but traditional anatomical lan...BACKGROUND Arm-implanted totally implantable venous access devices(peripherally inserted central catheter port)have become an important vascular access for colorectal cancer chemotherapy,but traditional anatomical landmark positioning techniques have issues with inaccurate positioning and high complication rates.AIM To evaluate the clinical value of image pre-measurement combined with intracavitary electrocardiogram(IC-ECG)positioning technology in arm port implantation for colorectal cancer patients.METHODS A retrospective analysis was conducted on 216 colorectal cancer patients who received arm port implantation in our hospital from January 2024 to December 2024.Patients were divided into an experimental group(image pre-measurement combined with IC-ECG positioning technology,n=103)and a control group(traditional anatomical landmark positioning technique,n=113).Technical success rate,operation time,catheter tip position accuracy,number of intraoperative catheter adjustments,X-ray exposure time,and postoperative complication rates were compared between the two groups.RESULTS The experimental group demonstrated superior outcomes compared to the control group across all key measures.Technical success rate was higher(98.4%vs 92.7%,P<0.05)with significantly reduced operation time(23.6±5.2 minutes vs 31.5±7.8 minutes,P<0.01).Catheter tip positioning accuracy improved substantially(97.6%vs 85.4%,P=0.002)while X-ray exposure time decreased by 71.8%(5.3±2.1 seconds vs 18.7±4.5 seconds,P<0.001).Threemonth complication rates were markedly lower in the experimental group(4.1%vs 14.6%,P=0.008),including significant reductions in catheter-related thrombosis(0.8%vs 4.9%),displacement(1.6%vs 5.7%),and occlusion(1.6%vs 4.1%).Multivariate analysis identified traditional technique as the strongest risk factor(odds ratio=4.27,P<0.001),while the combined IC-ECG approach was protective(odds ratio=0.34 for displacement,P=0.018).Long-term outcomes favored the experimental group with higher chemotherapy completion rates(97.1%vs 88.5%,P=0.014)and longer catheter dwelling time(189.5±45.3 days vs 162.7±53.8 days,P<0.001).CONCLUSION Image pre-measurement combined with intracavitary electrocardiogram positioning technology in arm port implantation for colorectal cancer patients can significantly improve catheter tip positioning accuracy,reduce operation time and X-ray exposure.展开更多
Pre-Authentication and Post-Connection(PAPC)plays a crucial role in realizing the Zero Trust security model by ensuring that access to network resources is granted only after successful authentication.While earlier ap...Pre-Authentication and Post-Connection(PAPC)plays a crucial role in realizing the Zero Trust security model by ensuring that access to network resources is granted only after successful authentication.While earlier approaches such as Port Knocking(PK)and Single Packet Authorization(SPA)introduced pre-authentication concepts,they suffer from limitations including plaintext communication,protocol dependency,reliance on dedicated clients,and inefficiency under modern network conditions.These constraints hinder their applicability in emerging distributed and resource-constrained environments such as AIoT and browser-based systems.To address these challenges,this study proposes a novel port-sequence-based PAPC scheme structured as a modular model comprising a client,server,and ephemeral Key Management System(KMS).The system employs the Advanced Encryption Standard(AES-128)to protect message confidentiality and uses a Hash-Based Message Authentication Code(HMAC-SHA256)to ensure integrity.Authentication messages are securely fragmented and mapped to destination port numbers using a signature-based avoidance algorithm,which prevents collisions with unsafe or reserved port ranges.The server observes incoming port sequences,retrieves the necessary keys from the KMS,reconstructs and verifies the encrypted data,and conditionally updates firewall policies.Unlike SPA,which requires decrypting all incoming payloads and imposes server-side overhead,the proposed system verifies only port-derived fragments,significantly reducing computational burden.Furthermore,it eliminates the need for raw socket access or custom clients,supporting browser-based operation and enabling protocol-independent deployment.Through a functional web-based prototype and emulated testing,the system achieved an F1-score exceeding 95%in detecting unauthorized access while maintaining low resource overhead.Although port sequence generation introduces some client-side cost,it remains lightweight and scalable.By tightly integrating lightweight cryptographic algorithms with a transport-layer communication model,this work presents a conceptually validated architecture that contributes a novel direction for interoperable and scalable Zero Trust enforcement in future network ecosystems.展开更多
基金This work was supported by the National Key Research and Development Program of China(Grant No.2018YFB1600403)the Natural Science Foundation of Chongqing,China(Grant No.cstc2020jcyj-bshX0043).
文摘Ported wall extensions are important hydraulic structures used to reduce crosscurrents in upper approaches to locks.The effect of such extensions located upstream of a solid guard wall on flow characteristics depends on many factors,including geometric and hydraulic parameters.In this study,the hydraulic performance of ported wall extensions was experimentally investigated in terms of the permeability coefficient,expanding angle,extension length,and flow depth.The results demonstrate that the dimensionless maximum transverse velocity is closely related to the permeability coefficient,expanding angle,and flow depth.By contrast,the dimensionless eddy length mainly depends on the permeability coefficient,expanding angle,and extension length.Furthermore,the optimum permeability coefficient increases with the expanding angle or flow depth,and it is approximately constant for different extension lengths.These results have the potential to provide direct guidance for the design of effective ported wall extensions in upper approaches to locks.
文摘A series of polymer- supported Pd -Fe2O3 composite catalysts were prepared and their hydrogenation property mas investigated. It was found that the above catalysts have good catalytic hydrogenation activity for carbon - carbon double bonds systems and reusability. Furthermore, XPS and IR spectra shouted that active component in the composite catalysts is atomic Pd(0). An addition of a small amount of Fe2O3 has a promotive action upon hydrogenation activity of the catalysts, which indicated that there are some strong interactions (electron transfer) between Pd(0) and Fe(Ⅲ) species. Based on these results, a possible catalytic hydrogenation mechanism was also suggested.
文摘 In this issue of the Journal of Geriatric Cardiology,Yang et al.1 studied the effects of arotinolol, a beta-blocker (BB), on the right ventricular (RV) function.……
文摘Purpose: To report a novel technique of laparoscopic 10 mm Single Port Access IntraPeritoneal Onlay Mesh (SPA-IPOM) using bioresorbable composite mesh fixed with Endoclose suture (percutaneous subcutaneous suture) in 3 cases of bilateral inguinal hernia. Methods: Laparoscopic SPA-IPOM is done through a 10 mm trocar with one 10 mm instrument that has 5 mm optical lens and 5 mm channel for grasper. After inserting 10 mm trocar at umbilicus using semi-open technique, intraperitoneal anatomical landmark of inguinal her-nia is identified. A 10 × 15 cm pre-tied bioresorbable composite mesh is then placed to cover hernia defect and all three potential area of indirect, direct and femoral hernia. Using Endoclose? needle, each pair of pre-tied sutures is retrieved percutaneously through a needle wound and extracorporeal tied with knot in subcutaneous space. After the upper half of mesh is sutured to the posterior surface of abdominal wall, the lower half of mesh is fixed by hernia tacker to Symphysis Pubis, Cooper Ligament and Iliopubic tract. Re-sults: Three men, average 48 year olds were operated by laparoscopic 10 mm SPA-IPOM for bilateral in-guinal hernia repair using bioresorbable composite mesh. Average operative time was 36 minutes. No imme-diate complication. All patients were discharge on the 2nd post-operative day and average 6 months follow up has no recurrence. Conclusions: Laparoscopic SPA-IPOM is an optional operation and is much easier to be performed. Benefits include operative time saving, cosmesis, early discharge and early return to work. Bio-resorbable composite mesh prevents bowel adhesion, however, is much more expensive. Long term follow up study for complications and recurrence is needed.
文摘Extending the operational range of centrifugal compressors is strategically vital for turbocharging internal combustion engines,particularly in enhancing efficiency and expanding operational capabilities.This extension is crucial for reducing environmental impact by enabling engines to perform more efficiently under a wider range of conditions.In the transition from conventional thermal reciprocating engines,fuel cells,especially proton exchange membrane fuel cells(PEMFCs),are emerging as strong alternatives.In automotive applications,PEMFCs often require turbocharging to supply compressed air to the cathode system of the fuel cell stack.This integration is essential for utilizing the heat from the fuel cell's waste products,thereby improving overall system efficiency.Ongoing research and development in radial turbomachinery are critical for optimizing the performance of these propulsion systems.Specifically,adapting turbocharger designs to meet the unique requirements of fuel cell systems and extending their operational range are essential tasks.Using a simplified CFD model,the impact of a ported shroud on compressor performance and range extension has been investigated.Flow structure analysis identified that the primary role of the ported shroud is to modify the relative flow angle on the rotor at the highest span channel.Additionally,a simplified analytical model was developed to quantify the effectiveness of different ported shroud geometries on the compressor by examining changes in tangential velocity after mixing with the flow from the cavity.
文摘Ⅰ. INTRODUCTION The classical Kirchhoff’s theory of thin plates without taking the effect of transverse shear deformation into account can give exact enough results when the thickness h of a plate is small in comparison with the other characteristic sizes. How-
文摘The Ministry of Environmental Protection’s environmentcomplaint office said on December 21 st,2009that more than half of the complaints it received viapublic hotline in November 2009 were related tochemical,non-metal mining process,metal refining andpaper making industries.And chemical sector is stillthe key reported target,occupying 28% of the total.InNovember,the reports on paper making and its related,and power and heat producers rose.The local environ-
基金supported by Ningbo Natural Science Foundation(No.2023J059)Ningbo Commonweal Programme Key Project(No.2023S038)Guangxi Key Research and Development Programme(No.GuikeAB21220063).
文摘Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition with Random Forest algorithm to investigate ozone dynamics and formation regimes in a coastal area of China.During the period of 2017–2022,significant inter-annual fluctuations emerged,with peaks in mid-2017 attributed to volatile organic compounds(VOCs),and in late-2019 influenced by air temperature.Multifaceted periodicities(daily,weekly,holiday,and yearly)in ozone were revealed,elucidating substantial influences of daily and yearly components on ozone periodicity.A VOC-sensitive ozone formation regime was identified,characterized by lower VOCs/NO_(x) ratios(average=0.88)and significant positive correlations between ozone and VOCs.This interplay manifested in elevated ozone duringweekends,holidays,and pandemic lockdowns.Key variables influencing ozone across diverse timescaleswere uncovered,with solar radiation and temperature driving daily and yearly ozone variations,respectively.Precursor substances,particularly VOCs,significantly shaped weekly/holiday patterns and long-term trends of ozone.Specifically,acetone,ethane,hexanal,and toluene had a notable impact on the multi-year ozone trend,emphasizing the urgency of VOC regulation.Furthermore,our observations indicated that NO_(x) primarily drived the stochastic variations in ozone,a distinguishing characteristic of regions with heavy traffic.This research provides novel insights into ozone dynamics in coastal urban areas and highlights the importance of integrating statistical and machinelearning methods in atmospheric pollution studies,with implications for targeted mitigation strategies beyond this specific region and pollutant.
文摘Ports,the core hub of global supply chains,serve as vital links in the economic and trade exchanges among countries.Efficient,safe,green and smart ports are essential for the smooth operation of global trade.Recently,ISO established ISO/TC 8/SC 27,Ports and terminals,the secretariat of which is held by China.This is a big breakthrough of China’s participation in the international standardization activities in the area of transportation.
文摘With the commissioning of Phase$,the port of Kribi is emerging as an important maritime transport hub in Central Africa With a 715-metre quay and a draught of 16 metres,the Autonomous Port of Kribi(APK)stands as one of Africa’s most strategically significant deep-water ports.Situated on Cameroon’s Atlantic coast,it o!ers direct access to international shipping lanes and is designed to handle large-capacity vessels that many regional ports cannot accommodate.
文摘Ghana’s Tema Port marked a historic milestone on 16 January 2024 with the arrival of Maersk Edirne,a 13,676-TEU container vessel-one of the largest of its kind globally-as part of Maersk’s newly launched Far East-West Africa express service.
文摘The efficient transportation of goods is vital for the economic growth of communities,making developing and maintaining seaport infrastructure an essential component of the marine transportation system.Given their geographic locations,ports are consistently at risk from natural hazards,making the resilience of port infrastructure an essential goal.Despite considerable progress in resilience research,there remains a gap in methods tailored explicitly to assessing port resilience,particularly under extreme wind events.Current approaches often do not capture the full complexity of port systems,as they tend to focus on isolated aspects,such as structural resilience.This paper introduces the PORT Resilience Framework,addressing these gaps by evaluating resilience through a comprehensive list of indicators gathered from various legitimate sources.The indicators are then organized under four comprehensive resilience dimensions:Physical Infrastructure,ICT(i.e.,Information and Communication Technology)and Equipment;Organization and Business Management;Resources and Economic Development;and Territory,Environment,and Stakeholders.This classification is summarized under the acronym"PORT."This paper also introduces a method for aggregating resilience indicators by considering their performance before and after a specific hazard,transforming the data into a quantifiable Loss of Resilience index.The approach is applied to a case study,assessing the resilience of a real Terminal against wind action using real data sourced from the port management.The case study analysis revealed that human resources and quay operations were the most critical factors affecting recovery,with insufficient staffing leading to prolonged recovery periods.The study further demonstrated that post-disruption activity surges,captured by different serviceability function methodologies,often created operational bottlenecks,challenging the port's overall recovery.
基金Supported by the Affiliated Hospital of Xuzhou Medical University,No.2024ZH04Xuzhou Municipal Science and Technology Bureau,No.KC23282.
文摘BACKGROUND Arm-implanted totally implantable venous access devices(peripherally inserted central catheter port)have become an important vascular access for colorectal cancer chemotherapy,but traditional anatomical landmark positioning techniques have issues with inaccurate positioning and high complication rates.AIM To evaluate the clinical value of image pre-measurement combined with intracavitary electrocardiogram(IC-ECG)positioning technology in arm port implantation for colorectal cancer patients.METHODS A retrospective analysis was conducted on 216 colorectal cancer patients who received arm port implantation in our hospital from January 2024 to December 2024.Patients were divided into an experimental group(image pre-measurement combined with IC-ECG positioning technology,n=103)and a control group(traditional anatomical landmark positioning technique,n=113).Technical success rate,operation time,catheter tip position accuracy,number of intraoperative catheter adjustments,X-ray exposure time,and postoperative complication rates were compared between the two groups.RESULTS The experimental group demonstrated superior outcomes compared to the control group across all key measures.Technical success rate was higher(98.4%vs 92.7%,P<0.05)with significantly reduced operation time(23.6±5.2 minutes vs 31.5±7.8 minutes,P<0.01).Catheter tip positioning accuracy improved substantially(97.6%vs 85.4%,P=0.002)while X-ray exposure time decreased by 71.8%(5.3±2.1 seconds vs 18.7±4.5 seconds,P<0.001).Threemonth complication rates were markedly lower in the experimental group(4.1%vs 14.6%,P=0.008),including significant reductions in catheter-related thrombosis(0.8%vs 4.9%),displacement(1.6%vs 5.7%),and occlusion(1.6%vs 4.1%).Multivariate analysis identified traditional technique as the strongest risk factor(odds ratio=4.27,P<0.001),while the combined IC-ECG approach was protective(odds ratio=0.34 for displacement,P=0.018).Long-term outcomes favored the experimental group with higher chemotherapy completion rates(97.1%vs 88.5%,P=0.014)and longer catheter dwelling time(189.5±45.3 days vs 162.7±53.8 days,P<0.001).CONCLUSION Image pre-measurement combined with intracavitary electrocardiogram positioning technology in arm port implantation for colorectal cancer patients can significantly improve catheter tip positioning accuracy,reduce operation time and X-ray exposure.
基金supported by Institute for Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea government(MSIT)(No.RS-2022-II221200)Convergence Security Core Talent Training Business(Chungnam National University).
文摘Pre-Authentication and Post-Connection(PAPC)plays a crucial role in realizing the Zero Trust security model by ensuring that access to network resources is granted only after successful authentication.While earlier approaches such as Port Knocking(PK)and Single Packet Authorization(SPA)introduced pre-authentication concepts,they suffer from limitations including plaintext communication,protocol dependency,reliance on dedicated clients,and inefficiency under modern network conditions.These constraints hinder their applicability in emerging distributed and resource-constrained environments such as AIoT and browser-based systems.To address these challenges,this study proposes a novel port-sequence-based PAPC scheme structured as a modular model comprising a client,server,and ephemeral Key Management System(KMS).The system employs the Advanced Encryption Standard(AES-128)to protect message confidentiality and uses a Hash-Based Message Authentication Code(HMAC-SHA256)to ensure integrity.Authentication messages are securely fragmented and mapped to destination port numbers using a signature-based avoidance algorithm,which prevents collisions with unsafe or reserved port ranges.The server observes incoming port sequences,retrieves the necessary keys from the KMS,reconstructs and verifies the encrypted data,and conditionally updates firewall policies.Unlike SPA,which requires decrypting all incoming payloads and imposes server-side overhead,the proposed system verifies only port-derived fragments,significantly reducing computational burden.Furthermore,it eliminates the need for raw socket access or custom clients,supporting browser-based operation and enabling protocol-independent deployment.Through a functional web-based prototype and emulated testing,the system achieved an F1-score exceeding 95%in detecting unauthorized access while maintaining low resource overhead.Although port sequence generation introduces some client-side cost,it remains lightweight and scalable.By tightly integrating lightweight cryptographic algorithms with a transport-layer communication model,this work presents a conceptually validated architecture that contributes a novel direction for interoperable and scalable Zero Trust enforcement in future network ecosystems.
