Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.T...Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.展开更多
BACKGROUND The Food and Drug Administration has approved percutaneous atrial septal defect(ASD)and patent foramen ovale(PFO)closure devices for hemodynamically significant interatrial shunts,paradoxical emboli includi...BACKGROUND The Food and Drug Administration has approved percutaneous atrial septal defect(ASD)and patent foramen ovale(PFO)closure devices for hemodynamically significant interatrial shunts,paradoxical emboli including stroke,and decompression sickness.We aimed to study the trends in utilization and reimbursements of transcatheter ASD/PFO closure devices.AIM To analyze trends in utilization and Medicare reimbursements for transcatheter ASD/PFO closure procedures from 2013 to 2022.METHODS A query of administrative data on United States Medicare beneficiaries undergoing transcatheter ASD/PFO was conducted from 2013 to 2022 using the Centers for Medicare and Medicaid Services Part B National Summary Data File.Inflation adjustments were made using the 2023 Consumer Price Index.Trend analysis was quantified using growth rate and simple linear regression calculations.All analyses were performed using Microsoft Excel 16.77.1(2023).RESULTS The annual number of transcatheter ASD/PFO closure procedures increased by 81%since 2013,with an average yearly growth rate of 44%cases per year(P<0.001).Annual Medicare reimbursements for transcatheter ASD/PFO therapies mirrored the annual procedure trends.The per-case reimbursements decreased by 18%,i.e.,$1128.80 in 2013 and$770.21 in 2022(P<0.001).There was a significant drop in the number of procedures in the year 2020,which correlates to the onset of the coronavirus disease 2019 pandemic,followed by a sharp uptick in the number of cases in 2021 and 2022.CONCLUSION Medicare utilization of transcatheter ASD/PFO closure therapies has grown significantly in procedural volume from 2013 to 2022.However,this has been accompanied by a decrease in per-case reimbursements.展开更多
Patent foramen ovale(PFO)is a common congenital heart disorder associated with stroke,decompression sickness and migraine.Combining synchronized contrast transcranial Doppler with contrast transthoracic echocardiograp...Patent foramen ovale(PFO)is a common congenital heart disorder associated with stroke,decompression sickness and migraine.Combining synchronized contrast transcranial Doppler with contrast transthoracic echocardiography has important clinical significance and can improve the accuracy of detecting right-left shunts(RLSs)in patients with PFO.In this letter,regarding an original study presented by Yao et al,we present our insights and discuss how to better help clinicians evaluate changes in PFO-related RLS.展开更多
Compared with traditional nickel-titanium alloy patent foramen ovale occluders,which are widely used in clinical practice,biodegradable patent foramen ovale occluders have obvious differences in material characteristi...Compared with traditional nickel-titanium alloy patent foramen ovale occluders,which are widely used in clinical practice,biodegradable patent foramen ovale occluders have obvious differences in material characteristics,interventional operation mode and postoperative management strategy.This article gives expert consensus on the selection of clinical indications and standardized operating procedures,so as to standardize the clinical application of biodegradable patent foramen ovale occluders.展开更多
This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwent...This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.展开更多
The collapse pressure is a key parameter when RTPs are applied in harsh deep-water environments.To investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are conducted.For the numerical ...The collapse pressure is a key parameter when RTPs are applied in harsh deep-water environments.To investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are conducted.For the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary effects.As for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with water.It has been observed that the cross-section of the middle part collapses when it reaches the maximum pressure.The collapse pressure obtained from the numerical simulations agrees well with that in the experiment.Meanwhile,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also discussed.It has a relatively greater difference because of the ignorance of the progressive failure of composites.For the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.展开更多
BACKGROUND Patent foramen ovale(PFO)-related right-to-left shunts(RLSs)have been impli-cated in cryptogenic stroke and migraine,with larger shunts posing a higher risk.When used individually to detect RLS,contrast tra...BACKGROUND Patent foramen ovale(PFO)-related right-to-left shunts(RLSs)have been impli-cated in cryptogenic stroke and migraine,with larger shunts posing a higher risk.When used individually to detect RLS,contrast transcranial Doppler(cTCD)and contrast transthoracic echocardiography(cTTE)may yield false-negative results.Further,the literature exposes gaps regarding the understanding of the limitations of cTCD and cTTE,presents conflicting recommendations on their exclusive use,and highlights inefficiencies associated with nonsynchronous testing.AIM To investigate the accuracy of multimodal ultrasound to improve diagnostic efficiency in detecting PFO-related RLSs.METHODS We prospectively enrolled four patients with cryptogenic stroke(n=1),migraine(n=2),and unexplained dizziness(n=1)who underwent synchronized cTCD combined with cTTE.The participants were monitored and followed-up for 24 months.RESULTS cTTE identified moderate and large RLSs in patients with recurrent cryptogenic stroke and migraines,whereas cTCD revealed only small RLSs.Moderate and large RLS were confirmed on combined cTTE and cTCD.After excluding other causes,both patients underwent PFO occlusion.At 21-and 24-month follow-up examinations,neither stroke nor migraine had recurred.cTTE revealed a small RLS in a third patient with unexplained dizziness and a fourth patient with migraines;however,simultaneous cTCD detected a large RLS.These patients did not undergo interventional occlusion,and dizziness and headache recurred at the 17-and 24-month follow-up examin-ations.CONCLUSION Using cTTE or cTCD may underestimate RLS,impairing risk assessments.Combining synchronized cTCD with cTTE could enhance testing accuracy and support better diagnostic and therapeutic decisions.展开更多
Background:White matter lesion(WML)is common in aging brain and is associated with cognitive impairment and dementia.However,recent studies reported an association between patent foramen ovale(PFO)and WML in migraineu...Background:White matter lesion(WML)is common in aging brain and is associated with cognitive impairment and dementia.However,recent studies reported an association between patent foramen ovale(PFO)and WML in migraineurs,especially in young,middle-aged migraineurs.Our retrospective,case-control study aims to describe the clinical characteristics of WML in this population and to explore potential risk factors.Methods:226 patients with migraine and PFO were consecutively initially screened.Relevant factors were selected by the least absolute shrinkage and selection operator(LASSO)regression and multivariable logistic regression model.A Nomogram was employed to visualize the prediction model conveniently.The discrimination and calibration abilities were evaluated using the Receiver Operating Characteristic(ROC)curve,the Hosmer-Lemeshow test,and calibration curves.Results:One hundred and nineteen participants were ultimately enrolled in our study,with a median age of 36.9±12.7 years and 80.7%of females.Brain magnetic resonance imaging MRI showed 67(56.3%)patients had WML,whereas 52(43.7%)patients were categorized into the non-WML group.LASSO regression screened out potential variables and subsequent multivariate analysisfinally identified age,mean platelet volume,andfibri-nogen(FIB)as independent predictive factors of WML.The area under the ROC curve(AUC)was 0.807.Hos-mer-Lemeshow test and calibration curve verified a consistency between the predicted and actual probability.Conclusion:The predictive nomogram established and validated in our study may assist clinicians in screening WML among young middle-aged migraineurs with PFO and developing individualized preventive and treatment strategies.展开更多
BACKGROUND To date,this is the first case of a paradoxical embolism(PDE)that concurrently manifested in the coronary and lower limb arteries and was secondary to a central venous catheter(CVC)thrombus via a patent for...BACKGROUND To date,this is the first case of a paradoxical embolism(PDE)that concurrently manifested in the coronary and lower limb arteries and was secondary to a central venous catheter(CVC)thrombus via a patent foramen ovale(PFO).CASE SUMMARY Here,we report a case of simultaneous coronary and lower limb artery embolism in a PFO patient carrier of a CVC.The patient presented to the hospital with acute chest pain and lower limb fatigue.Doppler ultrasound showed a large thrombus in the right internal jugular vein,precisely at the tip of the CVC.Transthoracic and transesophageal echocardiography confirmed the existence of a PFO,with inducible right-to-left shunting by the Valsalva maneuver.The patient was administered an extended course of anticoagulation therapy,and then the CVC was successfully removed.Percutaneous PFO closure was not undertaken.There was no recurrence during follow-up.CONCLUSION Thus,CVC-associated thrombosis is a potential source for multiple PDE in PFO patients.展开更多
Background The incidence of cryptogenic stroke(CS)accounts for about 25%of ischemic stroke.Current studies have shown that cryptogenic stroke is closely related to patent foramen ovale(PFO).Evaluating the correlation ...Background The incidence of cryptogenic stroke(CS)accounts for about 25%of ischemic stroke.Current studies have shown that cryptogenic stroke is closely related to patent foramen ovale(PFO).Evaluating the correlation between PFO and CS needs to be combined with multidisciplinary evaluation.Many clinical studies have shown that drug therapy can reduce the risk of ischemic stroke in elderly PFO patients(>60 years old).However,whether elderly PFO patients(>60 years old)can benefit from PFO closure is still controversial.This article reviewed the research progress of drug therapy and PFO closure therapy for cryptogenic stroke associated with PFO in the elderly.[S Chin J Cardiol 2024;25(1):50-56].展开更多
Atrial septal aneurysm(ASA)is defined as excursion of the atrial septum exceeding 10 mm beyond the atrial septum into the right or left atrium,or a combined total excursion of 15 mm on the right and left sides during ...Atrial septal aneurysm(ASA)is defined as excursion of the atrial septum exceeding 10 mm beyond the atrial septum into the right or left atrium,or a combined total excursion of 15 mm on the right and left sides during the cardiac cycle.According to previous studies,20–40%of patent foramen ovale(PFO)cases are accompanied by ASAs.ASA is associated with the presence of PFO,left atrial dysfunction,cryptogenic stroke,migraine,and arterial embolism,thus making closure of PFO in patients with concomitant ASA necessary but challenging.The anatomy of ASAs associated with PFO has crucial effects on complications after the closure procedure;therefore,several factors must be considered.Herein,we review the clinical implications of concomitant PFO and ASA;discuss the complications occurring after the closure procedure;and provide practical guidance for the closure of concomitant PFO and ASA.展开更多
A patent foramen ovale(PFO)is a clinical condition linked to ischemic stroke,aura migraine,and other pathologies.Current medical consensus posits that PFO closure may mitigate the risk of recurrent strokes.This case r...A patent foramen ovale(PFO)is a clinical condition linked to ischemic stroke,aura migraine,and other pathologies.Current medical consensus posits that PFO closure may mitigate the risk of recurrent strokes.This case report details the management of a 61-year-old female diagnosed with colon cancer for one month.Preoperative transthoracic echocardiography indicated a potential left-to-right shunt through the foramen ovale and mild regurgitation of both the mitral and aortic valves.The patient’s history revealed previous left-sided migraines,and a review of her medical records disclosed multifocal cerebral infarctions identified by a head CT.A pulmonary artery computed tomography angiography suggested embolization in the anterior branch of the right upper pulmonary artery and several branches of the right lower lung’s posterior and lateral basilar artery,along with thickening of the trunk canals of the pulmonary arteries.After a thorough assessment and extensive consultation with the surgical team,the procedure was transitioned from a laparoscopic radical resection to an open total colectomy.Anesthesia induction required careful avoidance of hypoxia,breath-holding,and coughing.Vigilant management of respiratory and circulatory functions was crucial during periods prone to intraoperative embolism formation.Postoperatively,attention was given to the stabilization of respiratory and circulatory functions during extubation,ensuring adequate sputum suction to prevent choking and close monitoring of breathing to avert airway obstruction post-extubation.Additionally,the patient was closely monitored for postoperative nausea and vomiting,a high-risk condition for this patient cohort.Strategies were implemented to minimize the risk of right-to-left shunting,ensuring the patient’s vital signs remained stable throughout the perioperative period.The patient was discharged safely after a 10-day recovery.For patients with cancer and PFO,comprehensive risk assessment and meticulous safety management are paramount.This case confirms the patient’s history of patent foramen ovale through the association between some atypical symptoms such as migraine,pulmonary embolism and cerebral infarction,which provides guidance for the management of anesthesia in the perioperative period,offering significant clinical implications.展开更多
Myxomas are primary cardiac tumors of the most common pathology, with 75% of myxomas originating in the left atrium either at the mitral annulus or the fossa ovalis border of the interatrial septum;the remaining 20% c...Myxomas are primary cardiac tumors of the most common pathology, with 75% of myxomas originating in the left atrium either at the mitral annulus or the fossa ovalis border of the interatrial septum;the remaining 20% come from the right atrium, and about 5% arise from both atria and the ventricle. Atrial myxomas are usually asymptomatic and are often detected when associated with complications due to tumor obstruction or emboli causing stroke. Due to the absence of symptoms, a diagnosis of a myxoma is often delayed until a significant embolic phenomenon, such as a stroke, occurs. We encountered such a scenario when a 62-year-old female presented to our hospital with right arm and leg weakness with her workup of stroke with a brain MRI showing numerous subacute infarcts consistent with embolic etiology. A routine transthoracic echo revealed a 2 × 5 cm atrial myxoma, which then led to the diagnosis of atrial myxoma along with a discovery of a patent foramen ovale (PFO), which subsequent surgical removal and PFO closure for definitive prevention of future embolic events. In this article, we aim to review the clinical presentation of cardiac myxoma along with appropriate investigations and treatment along with validation of the importance of timely echocardiograms with bubble studies in patients presenting with embolic stroke that can detect the atrial myxomas as a rare but potential cause of ischemic stroke.展开更多
The paper deduced a calculation formula by the classic control theory on the Reproducibility Error of parts processing in the technology system,the flexible clamp system, with the clamping device on the gas power,and ...The paper deduced a calculation formula by the classic control theory on the Reproducibility Error of parts processing in the technology system,the flexible clamp system, with the clamping device on the gas power,and analyzed its influencing factor with examples,the Reproducibility Error law:\ The larger the diameter of the cylinder,the smaller the error; the slower the tool speed,(k values smaller),the smaller the error.展开更多
The large design freedom of variable-stiffness (VS) composite material presupposes its potential for wide engineering application. Previous research indicates that the design of VS cylindrical structures helps to incr...The large design freedom of variable-stiffness (VS) composite material presupposes its potential for wide engineering application. Previous research indicates that the design of VS cylindrical structures helps to increase the buckling load as compared to quasi-isotropic (QI) cylindrical structures. This paper focuses on the anti-buckling performance of VS cylindrical structures under combined loads and the efficient optimization design method. Two kinds of conditions, bending moment and internal pressure, and bending moment and torque are considered. Influences of the geometrical defects, ovality, on the cylinder's performances are also investigated. To increase the computational efficiency, an adaptive Kriging meta-model is proposed to approximate the structural response of the cylinders. In this improved Kriging model, a mixed updating rule is used in constructing the meta-model. A genetic algorithm (GA) is implemented in the optimization design. The optimal results show that the buckling load of VS cylinders in all cases is greatly increased as compared with a QI cylinder.展开更多
In order to solve the problems of excess ovality and cross-section distortion of longitudinally submerged arc welding pipes after forming,a new three-roller continuous setting round process was proposed.This process c...In order to solve the problems of excess ovality and cross-section distortion of longitudinally submerged arc welding pipes after forming,a new three-roller continuous setting round process was proposed.This process can be divided into three stages:loading stage,roll bending stage and unloading stage.Based on the discretization idea,the mechanical model of the primary statically indeterminate problem of the longitudinally submerged arc welding pipes at the roll bending stage was established,and the deformation response was obtained.The simulation and theoretical results show that there are three positive bending regions and three reverse bending regions along the circumference of the pipe.The loading force of each roller shows growth,stability and downward trend with time.The error between the theoretical fitting curve and the simulated data point is very small,and the simulation results verify the reliability of the theoretical calculation.The experimental results show that the residual ovality decreases with the increase of the reduction,and the reduction of the turning point is the optimum reduction.In addition,the residual ovality of the pipe is less than 0.7%without cross-section distortion,which verifies the feasibility of this process.展开更多
网络安全漏洞扫描应充分考虑执行的效率和信息的共享。本文通过对OVAL和Nessus的介绍,分析O- VAL Definition与Nessus plugin之间的异同,提出并实现了一种将OVAL公布的漏洞信息转换成Nessus扫描插件的方法,共享了漏洞信息,并提升了漏洞...网络安全漏洞扫描应充分考虑执行的效率和信息的共享。本文通过对OVAL和Nessus的介绍,分析O- VAL Definition与Nessus plugin之间的异同,提出并实现了一种将OVAL公布的漏洞信息转换成Nessus扫描插件的方法,共享了漏洞信息,并提升了漏洞检测的品质。最后经过实验说明该方法的可行性。展开更多
To study the collapse of imperfect subsea pipelinos, a 2D high-order nonlinear model is developed. In this model, the large deformation of the pipes is considered by raiaining the high-order nonlinear terms of strain....To study the collapse of imperfect subsea pipelinos, a 2D high-order nonlinear model is developed. In this model, the large deformation of the pipes is considered by raiaining the high-order nonlinear terms of strain. In addi-tion, the J2 plastic flow theory is adopted to describe the elasioplastic constitutive relations of material. The quasi-static process of collapse is analyzed by the increment method. For each load step, the equations based on the principle of virtual work are presented and solved by the discrete Newton＇s method. Furthermore, finite element simulations and full-scale experiments were preformed to validate the results of the model. Research on the major influencing factors of collapse pressure, including D/t, material type and initial ovality, is also presented.展开更多
基金supported by the National Key R&D Program of China(2022YFF0504400)the National Natural Science Foundation of China(42188101,42274195,42174193)+2 种基金the International Partnership Program Of Chinese Academy of Sciences(Grant No.183311KYSB20200003)the USTC Research Funds of the Double First-Class Initiative(YD2080002013)the Joint Open Fund of Mengcheng National Geophysical Observatory(MENGO-202408).
文摘Statistical characteristics and the classification of the topside ionospheric mid-latitude trough are systemically analyzed,using observations from the Defense Meteorological Satellite Program F18(DMSP-F18)satellite.The data was obtained at an altitude of around 860 km in near polar orbit,throughout 2013.Our study identified the auroral boundary based on the in-situ electron density and electron spectrum,allowing us to precisely determine the location of the mid-latitude trough.This differs from most previous works,which only use Total Electron Content(TEC)or in-situ electron density.In our study,the troughs exhibited a higher occurrence rate in local winter than in summer,and extended to lower latitudes with increasing geomagnetic activity.It was found that the ionospheric mid-latitude trough,which is associated with temperature changes or enhanced ion drift,exhibited distinct characteristics.Specifically,the ionospheric mid-latitude troughs related to electron temperature(Te)peak were located more equatorward of auroral oval boundary in winter than in summer.The ionospheric mid-latitude troughs related to Te-maximum were less frequently observed at 60−70°S magnetic latitude and 90−240°E longitude.Furthermore,the troughs related to ion temperature(Ti)maximums were observed at relatively higher latitudes,occurring more frequently in winter.In addition,the troughs related to ion velocity(Vi)maximums could be observed in all seasons.The troughs with the maximum-Ti and maximum-Vi were located closer to the equatorward boundary of the auroral oval at the nightside,and in both hemispheres.This implies that enhanced ion drift velocity contributes to increased collisional frictional heating and enhanced ion temperatures,resulting in a density depletion within the trough region.
文摘BACKGROUND The Food and Drug Administration has approved percutaneous atrial septal defect(ASD)and patent foramen ovale(PFO)closure devices for hemodynamically significant interatrial shunts,paradoxical emboli including stroke,and decompression sickness.We aimed to study the trends in utilization and reimbursements of transcatheter ASD/PFO closure devices.AIM To analyze trends in utilization and Medicare reimbursements for transcatheter ASD/PFO closure procedures from 2013 to 2022.METHODS A query of administrative data on United States Medicare beneficiaries undergoing transcatheter ASD/PFO was conducted from 2013 to 2022 using the Centers for Medicare and Medicaid Services Part B National Summary Data File.Inflation adjustments were made using the 2023 Consumer Price Index.Trend analysis was quantified using growth rate and simple linear regression calculations.All analyses were performed using Microsoft Excel 16.77.1(2023).RESULTS The annual number of transcatheter ASD/PFO closure procedures increased by 81%since 2013,with an average yearly growth rate of 44%cases per year(P<0.001).Annual Medicare reimbursements for transcatheter ASD/PFO therapies mirrored the annual procedure trends.The per-case reimbursements decreased by 18%,i.e.,$1128.80 in 2013 and$770.21 in 2022(P<0.001).There was a significant drop in the number of procedures in the year 2020,which correlates to the onset of the coronavirus disease 2019 pandemic,followed by a sharp uptick in the number of cases in 2021 and 2022.CONCLUSION Medicare utilization of transcatheter ASD/PFO closure therapies has grown significantly in procedural volume from 2013 to 2022.However,this has been accompanied by a decrease in per-case reimbursements.
文摘( )1.Can you look___this report today?A.out B.towards C.over D.together( )2.The egg isn't round.It's an___.A.fact B.oval C.part D.reason( )3.Only a___apple remained in the basket.A.single B.surprised C.scared D.strong( )4.Carrots are my favorite___.
文摘Patent foramen ovale(PFO)is a common congenital heart disorder associated with stroke,decompression sickness and migraine.Combining synchronized contrast transcranial Doppler with contrast transthoracic echocardiography has important clinical significance and can improve the accuracy of detecting right-left shunts(RLSs)in patients with PFO.In this letter,regarding an original study presented by Yao et al,we present our insights and discuss how to better help clinicians evaluate changes in PFO-related RLS.
基金Chinese Academy of Medical Sciences Fuwai Hospital High Level Hospital clinical research fund(2022-GSPGG-18).
文摘Compared with traditional nickel-titanium alloy patent foramen ovale occluders,which are widely used in clinical practice,biodegradable patent foramen ovale occluders have obvious differences in material characteristics,interventional operation mode and postoperative management strategy.This article gives expert consensus on the selection of clinical indications and standardized operating procedures,so as to standardize the clinical application of biodegradable patent foramen ovale occluders.
基金supported by grants from National High-Level Hospital Clinical Research Funding(2023-GSP-RC-04).
文摘This study aimed to evaluate the feasibility,safety,and efficacy of a noveltranscatheter suture closure system(HaloStitch^(®))for patent foramen ovale(PFO)closure in a swine model.Methods:Thirteen swine underwentexperimental PF0 model creation.All animals received implantationof the transcatheter suture closure system to evaluate procedural success.Comprehensive follow-up over sixmonths included serial ultrasound imaging,histopathological analysis,and gross anatomical exaninationof cardiac specimens.Results:Successful HaloStitch^(®)device implantation was adhieved in 11 of 13 swine.Gross anatomical examination confirrned secure positioning of all sutures in the atrial septum,with noredundancy or thrombus formation.Postoperative ultrasound demonstrated stable suture and staplepositions throughout follow-up,with no evidence of suture breakage,displacement,or thrombus.Stapleswere clearly visualized under ultrasound imaging,Both the atrial septal defect orifice diameter and residualseptal shunt flow velocity decreased significantly during the observation period.Histopathological analysisrevealed partially organized thrombi at the implant head and fibrous connective tissue encapsulation withlocalized inflammatory cell infiltration surrounding the polymer material.Conclsions:The transcathetersuture closure system(HaloStitch^(®))demonstrated feasibility,safety,and biocompatib ility for PFO closure ina swine model,supporting its potential for clinical translation.
基金financially supported by National Natural Science Foundation of China(Grant Nos.52088102,51879249)Fundamental Research Funds for the Central Universities(Grant No.202261055)。
文摘The collapse pressure is a key parameter when RTPs are applied in harsh deep-water environments.To investigate the collapse of RTPs,numerical simulations and hydrostatic pressure tests are conducted.For the numerical simulations,the eigenvalue analysis and Riks analysis are combined,in which the Hashin failure criterion and fracture energy stiffness degradation model are used to simulate the progressive failure of composites,and the“infinite”boundary conditions are applied to eliminate the boundary effects.As for the hydrostatic pressure tests,RTP specimens were placed in a hydrostatic chamber after filled with water.It has been observed that the cross-section of the middle part collapses when it reaches the maximum pressure.The collapse pressure obtained from the numerical simulations agrees well with that in the experiment.Meanwhile,the applicability of NASA SP-8007 formula on the collapse pressure prediction was also discussed.It has a relatively greater difference because of the ignorance of the progressive failure of composites.For the parametric study,it is found that RTPs have much higher first-ply-failure pressure when the winding angles are between 50°and 70°.Besides,the effect of debonding and initial ovality,and the contribution of the liner and coating are also discussed.
基金Supported by The Shenzhen Second People’s Hospital Clinical Research Fund of the Shenzhen High-level Hospital Construction Project,No.20223357021 and No.20243357001Research Project of Teaching Reform in Shenzhen Second People’s Hospital,No.202209Guangdong Province Basic and Applied Basic Research Fund Project,No.2020B1515120061.
文摘BACKGROUND Patent foramen ovale(PFO)-related right-to-left shunts(RLSs)have been impli-cated in cryptogenic stroke and migraine,with larger shunts posing a higher risk.When used individually to detect RLS,contrast transcranial Doppler(cTCD)and contrast transthoracic echocardiography(cTTE)may yield false-negative results.Further,the literature exposes gaps regarding the understanding of the limitations of cTCD and cTTE,presents conflicting recommendations on their exclusive use,and highlights inefficiencies associated with nonsynchronous testing.AIM To investigate the accuracy of multimodal ultrasound to improve diagnostic efficiency in detecting PFO-related RLSs.METHODS We prospectively enrolled four patients with cryptogenic stroke(n=1),migraine(n=2),and unexplained dizziness(n=1)who underwent synchronized cTCD combined with cTTE.The participants were monitored and followed-up for 24 months.RESULTS cTTE identified moderate and large RLSs in patients with recurrent cryptogenic stroke and migraines,whereas cTCD revealed only small RLSs.Moderate and large RLS were confirmed on combined cTTE and cTCD.After excluding other causes,both patients underwent PFO occlusion.At 21-and 24-month follow-up examinations,neither stroke nor migraine had recurred.cTTE revealed a small RLS in a third patient with unexplained dizziness and a fourth patient with migraines;however,simultaneous cTCD detected a large RLS.These patients did not undergo interventional occlusion,and dizziness and headache recurred at the 17-and 24-month follow-up examin-ations.CONCLUSION Using cTTE or cTCD may underestimate RLS,impairing risk assessments.Combining synchronized cTCD with cTTE could enhance testing accuracy and support better diagnostic and therapeutic decisions.
文摘Background:White matter lesion(WML)is common in aging brain and is associated with cognitive impairment and dementia.However,recent studies reported an association between patent foramen ovale(PFO)and WML in migraineurs,especially in young,middle-aged migraineurs.Our retrospective,case-control study aims to describe the clinical characteristics of WML in this population and to explore potential risk factors.Methods:226 patients with migraine and PFO were consecutively initially screened.Relevant factors were selected by the least absolute shrinkage and selection operator(LASSO)regression and multivariable logistic regression model.A Nomogram was employed to visualize the prediction model conveniently.The discrimination and calibration abilities were evaluated using the Receiver Operating Characteristic(ROC)curve,the Hosmer-Lemeshow test,and calibration curves.Results:One hundred and nineteen participants were ultimately enrolled in our study,with a median age of 36.9±12.7 years and 80.7%of females.Brain magnetic resonance imaging MRI showed 67(56.3%)patients had WML,whereas 52(43.7%)patients were categorized into the non-WML group.LASSO regression screened out potential variables and subsequent multivariate analysisfinally identified age,mean platelet volume,andfibri-nogen(FIB)as independent predictive factors of WML.The area under the ROC curve(AUC)was 0.807.Hos-mer-Lemeshow test and calibration curve verified a consistency between the predicted and actual probability.Conclusion:The predictive nomogram established and validated in our study may assist clinicians in screening WML among young middle-aged migraineurs with PFO and developing individualized preventive and treatment strategies.
基金Supported by Natural Science Foundation of Guangdong Province,No.2021A1515011267and Guangzhou Municipal Science and Technology Bureau,No.2023A03J0984.
文摘BACKGROUND To date,this is the first case of a paradoxical embolism(PDE)that concurrently manifested in the coronary and lower limb arteries and was secondary to a central venous catheter(CVC)thrombus via a patent foramen ovale(PFO).CASE SUMMARY Here,we report a case of simultaneous coronary and lower limb artery embolism in a PFO patient carrier of a CVC.The patient presented to the hospital with acute chest pain and lower limb fatigue.Doppler ultrasound showed a large thrombus in the right internal jugular vein,precisely at the tip of the CVC.Transthoracic and transesophageal echocardiography confirmed the existence of a PFO,with inducible right-to-left shunting by the Valsalva maneuver.The patient was administered an extended course of anticoagulation therapy,and then the CVC was successfully removed.Percutaneous PFO closure was not undertaken.There was no recurrence during follow-up.CONCLUSION Thus,CVC-associated thrombosis is a potential source for multiple PDE in PFO patients.
基金supported by the National Natural Science Foundation of China(No.81370242)the Guangdong Provincial College Students Innovation and Entrepreneurship Training Program in 2023(No.S202310571076)+3 种基金the Zhanjiang Science and Technology Program(No.2022A01166/No.2022A01183)the Non-funded Science and Technology Research Program of Zhanjiang(No.2021B01145)the Guangdong Medical University Youth Scientific Research Training Fund(No.GDMUQ2021011)the Universty-level Innovation and Entrepreneurship Training Program of Guangdong Medical University(No.GDMU2021163/No.GDMU2021207)。
文摘Background The incidence of cryptogenic stroke(CS)accounts for about 25%of ischemic stroke.Current studies have shown that cryptogenic stroke is closely related to patent foramen ovale(PFO).Evaluating the correlation between PFO and CS needs to be combined with multidisciplinary evaluation.Many clinical studies have shown that drug therapy can reduce the risk of ischemic stroke in elderly PFO patients(>60 years old).However,whether elderly PFO patients(>60 years old)can benefit from PFO closure is still controversial.This article reviewed the research progress of drug therapy and PFO closure therapy for cryptogenic stroke associated with PFO in the elderly.[S Chin J Cardiol 2024;25(1):50-56].
文摘Atrial septal aneurysm(ASA)is defined as excursion of the atrial septum exceeding 10 mm beyond the atrial septum into the right or left atrium,or a combined total excursion of 15 mm on the right and left sides during the cardiac cycle.According to previous studies,20–40%of patent foramen ovale(PFO)cases are accompanied by ASAs.ASA is associated with the presence of PFO,left atrial dysfunction,cryptogenic stroke,migraine,and arterial embolism,thus making closure of PFO in patients with concomitant ASA necessary but challenging.The anatomy of ASAs associated with PFO has crucial effects on complications after the closure procedure;therefore,several factors must be considered.Herein,we review the clinical implications of concomitant PFO and ASA;discuss the complications occurring after the closure procedure;and provide practical guidance for the closure of concomitant PFO and ASA.
基金supported by grants from the Anhui Provincial Natural Science Foundation(Grant No.2208085Y32 to Chaoliang Tang)the Chen Xiao-Ping Foundation for the Development of Science and Technology of Hubei Province(Grant No.CXPJJH12000005-07-115 to Chaoliang Tang).
文摘A patent foramen ovale(PFO)is a clinical condition linked to ischemic stroke,aura migraine,and other pathologies.Current medical consensus posits that PFO closure may mitigate the risk of recurrent strokes.This case report details the management of a 61-year-old female diagnosed with colon cancer for one month.Preoperative transthoracic echocardiography indicated a potential left-to-right shunt through the foramen ovale and mild regurgitation of both the mitral and aortic valves.The patient’s history revealed previous left-sided migraines,and a review of her medical records disclosed multifocal cerebral infarctions identified by a head CT.A pulmonary artery computed tomography angiography suggested embolization in the anterior branch of the right upper pulmonary artery and several branches of the right lower lung’s posterior and lateral basilar artery,along with thickening of the trunk canals of the pulmonary arteries.After a thorough assessment and extensive consultation with the surgical team,the procedure was transitioned from a laparoscopic radical resection to an open total colectomy.Anesthesia induction required careful avoidance of hypoxia,breath-holding,and coughing.Vigilant management of respiratory and circulatory functions was crucial during periods prone to intraoperative embolism formation.Postoperatively,attention was given to the stabilization of respiratory and circulatory functions during extubation,ensuring adequate sputum suction to prevent choking and close monitoring of breathing to avert airway obstruction post-extubation.Additionally,the patient was closely monitored for postoperative nausea and vomiting,a high-risk condition for this patient cohort.Strategies were implemented to minimize the risk of right-to-left shunting,ensuring the patient’s vital signs remained stable throughout the perioperative period.The patient was discharged safely after a 10-day recovery.For patients with cancer and PFO,comprehensive risk assessment and meticulous safety management are paramount.This case confirms the patient’s history of patent foramen ovale through the association between some atypical symptoms such as migraine,pulmonary embolism and cerebral infarction,which provides guidance for the management of anesthesia in the perioperative period,offering significant clinical implications.
文摘Myxomas are primary cardiac tumors of the most common pathology, with 75% of myxomas originating in the left atrium either at the mitral annulus or the fossa ovalis border of the interatrial septum;the remaining 20% come from the right atrium, and about 5% arise from both atria and the ventricle. Atrial myxomas are usually asymptomatic and are often detected when associated with complications due to tumor obstruction or emboli causing stroke. Due to the absence of symptoms, a diagnosis of a myxoma is often delayed until a significant embolic phenomenon, such as a stroke, occurs. We encountered such a scenario when a 62-year-old female presented to our hospital with right arm and leg weakness with her workup of stroke with a brain MRI showing numerous subacute infarcts consistent with embolic etiology. A routine transthoracic echo revealed a 2 × 5 cm atrial myxoma, which then led to the diagnosis of atrial myxoma along with a discovery of a patent foramen ovale (PFO), which subsequent surgical removal and PFO closure for definitive prevention of future embolic events. In this article, we aim to review the clinical presentation of cardiac myxoma along with appropriate investigations and treatment along with validation of the importance of timely echocardiograms with bubble studies in patients presenting with embolic stroke that can detect the atrial myxomas as a rare but potential cause of ischemic stroke.
基金Tianjin Nature Science Date(08JCYBJC 11700) "CAD System of Fixture on New Fixture Design Theory of Accuracy Design"
文摘The paper deduced a calculation formula by the classic control theory on the Reproducibility Error of parts processing in the technology system,the flexible clamp system, with the clamping device on the gas power,and analyzed its influencing factor with examples,the Reproducibility Error law:\ The larger the diameter of the cylinder,the smaller the error; the slower the tool speed,(k values smaller),the smaller the error.
基金the National NaturalScience Foundation of China (Grant 11572134)the China PostdoctoralScience Foundation (Grant 2017M612443).
文摘The large design freedom of variable-stiffness (VS) composite material presupposes its potential for wide engineering application. Previous research indicates that the design of VS cylindrical structures helps to increase the buckling load as compared to quasi-isotropic (QI) cylindrical structures. This paper focuses on the anti-buckling performance of VS cylindrical structures under combined loads and the efficient optimization design method. Two kinds of conditions, bending moment and internal pressure, and bending moment and torque are considered. Influences of the geometrical defects, ovality, on the cylinder's performances are also investigated. To increase the computational efficiency, an adaptive Kriging meta-model is proposed to approximate the structural response of the cylinders. In this improved Kriging model, a mixed updating rule is used in constructing the meta-model. A genetic algorithm (GA) is implemented in the optimization design. The optimal results show that the buckling load of VS cylinders in all cases is greatly increased as compared with a QI cylinder.
基金supported by the National Natural Science Foundation of China (Nos. 52005431, 51705449 and 51975509)the Natural Science Foundation of Hebei Province of China (No. E2020203086)the National Major Science and Technology Projects of China (No. 2018ZX04007002)
文摘In order to solve the problems of excess ovality and cross-section distortion of longitudinally submerged arc welding pipes after forming,a new three-roller continuous setting round process was proposed.This process can be divided into three stages:loading stage,roll bending stage and unloading stage.Based on the discretization idea,the mechanical model of the primary statically indeterminate problem of the longitudinally submerged arc welding pipes at the roll bending stage was established,and the deformation response was obtained.The simulation and theoretical results show that there are three positive bending regions and three reverse bending regions along the circumference of the pipe.The loading force of each roller shows growth,stability and downward trend with time.The error between the theoretical fitting curve and the simulated data point is very small,and the simulation results verify the reliability of the theoretical calculation.The experimental results show that the residual ovality decreases with the increase of the reduction,and the reduction of the turning point is the optimum reduction.In addition,the residual ovality of the pipe is less than 0.7%without cross-section distortion,which verifies the feasibility of this process.
文摘网络安全漏洞扫描应充分考虑执行的效率和信息的共享。本文通过对OVAL和Nessus的介绍,分析O- VAL Definition与Nessus plugin之间的异同,提出并实现了一种将OVAL公布的漏洞信息转换成Nessus扫描插件的方法,共享了漏洞信息,并提升了漏洞检测的品质。最后经过实验说明该方法的可行性。
基金Supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2011ZX05026-005)the National Natural Science Foundation of China(No.51239008)the National Basic Research Program of China("973"Program,No.2014CB046800)
文摘To study the collapse of imperfect subsea pipelinos, a 2D high-order nonlinear model is developed. In this model, the large deformation of the pipes is considered by raiaining the high-order nonlinear terms of strain. In addi-tion, the J2 plastic flow theory is adopted to describe the elasioplastic constitutive relations of material. The quasi-static process of collapse is analyzed by the increment method. For each load step, the equations based on the principle of virtual work are presented and solved by the discrete Newton＇s method. Furthermore, finite element simulations and full-scale experiments were preformed to validate the results of the model. Research on the major influencing factors of collapse pressure, including D/t, material type and initial ovality, is also presented.
