Hypoplastic left heart syndrome is a severe congenital defect involving underdeveloped left-sided cardiac structures,leading to significant mortality and morbidity.Prenatal diagnosis using fetal ultrasound and echocar...Hypoplastic left heart syndrome is a severe congenital defect involving underdeveloped left-sided cardiac structures,leading to significant mortality and morbidity.Prenatal diagnosis using fetal ultrasound and echocardiography enables early detection,family counseling,and improved clinical decision-making.Advanced prenatal interventions,such as fetal aortic valvuloplasty and atrial septostomy,show promise but require careful patient selection.A multidisciplinary approach involving obstetricians,neonatologists,and pediatric cardiologists is vital for effective management.Future directions include refining imaging techniques,such as three-dimensional ultrasound,cardiovascular magnetic resonance imaging,and exploring bioengineering solutions,stem cell therapies,and genetic research.These advancements aim to improve therapeutic options and address current limitations,including transplant scarcity and postoperative complications.Although surgical innovations have improved survival rates,challenges remain,including neurological risks and long-term hemodynamic issues.Ongoing research and technological advancements are essential to enhance outcomes and quality of life for hypoplastic left heart syndrome patients.展开更多
The artificial ground-freezing method is the main technical means for the excavation of mines and tunnels through the water-rich sand layer,and the comprehensive understanding of the mechanical properties of frozen sa...The artificial ground-freezing method is the main technical means for the excavation of mines and tunnels through the water-rich sand layer,and the comprehensive understanding of the mechanical properties of frozen saturated sand and the stress-strain relationship under complex stress can provide important guidance.In this study,a series of true triaxial tests of frozen saturated sand samples were conducted.Combined with the test data,the effects of temperature and medium principal stress ratio(b)on the strength and deformation characteristics of frozen saturated sand are discussed.In addition,a cohesion tensor is introduced to the Wu-Lin hypoplastic model.A scalar value is used to characterize the effect of temperature on the strength of frozen soil.The defect that the original model cannot describe the tensile capacity of frozen soil under low stress conditions is clearly solved.In addition,the cumulative deformation state variable is introduced to improve the response performance of the model in triaxial compression tests.The hypoplastic model of frozen soil has shown good performance in simulating triaxial compression tests at different temperatures and medium principal stress ratios.展开更多
An incrementally nonlinear hypoplastic constitutive model was introduced, which was developed without recourse to the concepts in elastoplasticity theory such as yield surface, plastic potential and the decomposition ...An incrementally nonlinear hypoplastic constitutive model was introduced, which was developed without recourse to the concepts in elastoplasticity theory such as yield surface, plastic potential and the decomposition of the deformation into elastic and plastic parts. Triaxial drained tests on rockfill were conducted on a large scale triaxial apparatus under two types of stress paths, which were the stress paths of constant stress ratio and the complex stress paths with transitional features. Motivated by the effect of stress path, the Gudehus-Bauer hypoplastic model was improved by considering the parameter variations with different ratios of stress increment. Fitting parameter a presents a piecewise linear relationship with cosine of the slope angle θ determined by instantaneous stress path. The improved hypoplastic model can present peak stress increasing and volumetric strain changing from dilatancy to contractancy with the increase of transitional confining pressure σ3t and the decrease of slope angle θ of stress path. Compared with the test data, it is shown that the model is capable of fully considering the effect of stress path on rockfill.展开更多
Objective:This study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty(FPV)in fetuses with pulmonary atresia with intact ventricular septum(PA/IVS).Methods:From August...Objective:This study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty(FPV)in fetuses with pulmonary atresia with intact ventricular septum(PA/IVS).Methods:From August 31,2018,to May 31,2019,seven fetuses with PA/IVS and hypoplastic right heart were included in this study.All underwent echocardiography by the same specialist and were operated on by the same team.Intervention and echocardiography data were collected,and changes in the associated indices noted during follow-up were analyzed.Results:All seven fetuses successfully underwent FPV.The median gestational age at FPV was 27.54 weeks.The average FPV procedural time was 6 min.Persistent bradycardia requiring treatment occurred in 4/7 procedures.Finally,five pregnancies were successfully delivered,and the other two were aborted.Compared to data before fetal cardiac interventions(FCI),tricuspid valve annulus diameter/mitral valve annulus diameter(TV/MV)and right ventricle diameter/left ventricle diameter(RV/LV)of all fetuses had progressively improved.The maximum tricuspid regurgitation velocity decreased from 4.60 m/s to 3.64 m/s.The average follow-up time was 30.40±2.05 months.During the follow-up period,the diameter of the tricuspid valve ring in five children continued to improve,and the development rate of the tricuspid valve was relatively obvious from 6 months to 1 year after birth.However,the development of the right ventricle after birth was relatively slow.It was discovered that there were individual variations in the development of the right ventricle during follow-up.Conclusion:The findings support the potential for the development of the right ventricle and tricuspid valve in fetuses with PA/IVS who underwent FCI.Development of the right ventricle and tricuspid valve does not occur synchronously during pregnancy.The right ventricle develops rapidly in utero,but the development of tricuspid valve is more apparent after birth than in utero.展开更多
Background:Thromboembolic events are a cause of significant morbidity and mortality in the Fontan population.We previously reported on coagulation profile changes in a cohort of patients with hypoplastic left heart sy...Background:Thromboembolic events are a cause of significant morbidity and mortality in the Fontan population.We previously reported on coagulation profile changes in a cohort of patients with hypoplastic left heart syndrome(HLHS)from Stage I through Fontan completion.In this report,we examine their clinical status,anticoagulation and incidence of thromboembolic events up to 20 years post Fontan.Methods:A retrospective chart review was conducted for twenty(20)surviving patients,from 1998 through December 2020.Patients who underwent orthotopic heart transplantation(OTx)were followed until their transplant.Patients who were found in the original study to have a factor VIII activity level>160%,were examined separately.Results:Most patients had follow-up within the last two years(2018–2020).Two patients underwent OTx and two patients died.Anticoagulation strategy was variable.Most patients were on aspirin monotherapy.There was a total of twelve thrombotic events(63.2%).These included six cerebrovascular accidents(two of which were fatal).Three out of the seven patients with elevated factor VIII activity from the original study had thromboembolic events(42.9%).Fontan complications were variable.Some degree of Fontan Associated Liver Disease was universal.Conclusions:This retrospective review of a group of single-ventricle patients post Fontan,illustrates the variability in anticoagulation therapy that exists in this population.A large proportion of patients suffered a significant thromboembolic event,including the patients with elevated factor VIII.Further investigation into the patients with elevated factor VIII may help determine whether a different antithrombotic strategy post Fontan would be beneficial.展开更多
Background:Hypoplastic left heart syndrome(HLHS)is one of the most challenging congenital heart diseases in clinical treatment.In cardiac tissues,resident macrophages fulfill critical functions in maintaining a stable...Background:Hypoplastic left heart syndrome(HLHS)is one of the most challenging congenital heart diseases in clinical treatment.In cardiac tissues,resident macrophages fulfill critical functions in maintaining a stable cardiac state and have strong regenerative capacity and organ specificity.However,the molecular mechanisms of macro-phages in HLHS remained unclear.Methods:Single-nucleus RNA sequencing(snRNA-seq)data of HLHS and healthy control(donors)samples obtained from the Gene Expression Omnibus(GEO)database were normalized and clustered using the Seurat package.The“FindMarkers”function was used to screen differentially expressed genes(DEGs)between the HLHS and donor groups and to analyze the functional enrichment of the set of genes of interest.Finally,cell-cell communication,pseudotime,and single-cell regulatory network inference and cluster-ing(SCENIC)analyses were used to study the mechanisms of macrophages in HLHS.Results:Based on the snRNA-seq data of HLHS and donors,we identified a total of 9 cell clusters,among which the proportion of macrophages was significantly less in the HLHS group than in the control group.Subdivision of macrophage subpopulations(Macrophages 1,2,and 3)showed that Macrophages 1 was mainly involved in nervous system development,angiogenesis,and apoptotic processes.In addition,analysis of communication between Macro-phages 1 and cardiomyocytes revealed that ligand-acceptor pairs such as GAS6/AXL,IL6,IGF1,THY1,and L1CAM were present only in the donor group.Finally,pesudotime and SCENIC analyses demonstrated that FOXO3 and ELF2 played a critical role for Macrophages 1 to maintain cardiac function in patients with HLHS.Conclusion:Our study improved the current understanding of the molecular mechanisms of macrophage devel-opment in HLHS,showing that manipulating the regulatory role of macrophages in the heart can be a novel treat-ment for HLHS.展开更多
The diminutive aorta presents technical challenges in the palliation of hypoplastic left heart syndrome. Furthermore, aortic arch caliber changes and variable great vessel relationships can add complexity to an alread...The diminutive aorta presents technical challenges in the palliation of hypoplastic left heart syndrome. Furthermore, aortic arch caliber changes and variable great vessel relationships can add complexity to an already difficult arch repair. We describe a technical approach that simplifies the aortic reconstruction and makes the procedure more generalizable and reproducible.展开更多
Background:Fetal balloon atrial septoplasty(BAS)is performed through the restrictive foramen ovale in fetal cases with established hypoplastic left heart syndrome(HLHS)and an intact or highly restrictive atrial septum...Background:Fetal balloon atrial septoplasty(BAS)is performed through the restrictive foramen ovale in fetal cases with established hypoplastic left heart syndrome(HLHS)and an intact or highly restrictive atrial septum(RAS).Methods:In the current report,we present a case of high position BAS in a fetus with HLHS/RAS.Results:Echocardiography confirmed an adequate atrial opening above the foramen ovale and fetal pleural effusion resolved spontaneously 1 day after the procedure.Conclusion:To the best of our knowledge,the creation of a high position hole in the thinner part of the atrial septum,instead of the restrictive tiny hole,has not been reported in fetal cases with HLHS/RAS.展开更多
BACKGROUND Unilateral small-sized kidney is a radiological term referring to both the congenital and acquired causes of reduced kidney volume.However,the hypoplastic kidney may have peculiar clinical and radiological ...BACKGROUND Unilateral small-sized kidney is a radiological term referring to both the congenital and acquired causes of reduced kidney volume.However,the hypoplastic kidney may have peculiar clinical and radiological characterizations.AIM To evaluate the clinical presentations,complications,and management approaches of the radiologically diagnosed unilateral hypoplastic kidney.METHODS A retrospective review of the records of patients with a radiological diagnosis of unilateral hypoplastic kidney between July 2015 and June 2020 was done at Assiut Urology and Nephrology Hospital,Assiut University,Egypt.RESULTS A total of 33 cases were diagnosed to have unilateral hypoplastic kidney with a mean(range)age of 39.5±11.2(19-73)years.The main clinical presentation was loin pain(51.5%),stone passer(9.1%),anuria(12.1%),accidental discovery(15.2%),or manifestations of urinary tract infections(12.1%).Computed tomography was the most useful tool for radiological diagnosis.However,radioisotope scanning could be requested for verification of surgical interventions and nephrectomy decisions.Urolithiasis occurred in 23(69.7%)cases and pyuria was detected in 22(66.7%)cases where the infection was documented by culture and sensitivity test in 19 cases.While the non-complicated cases were managed by assurance only(12.1%),nephrectomy(15.2%)was performed for persistent complications.However,symptomatic(27.3%)and endoscopic(45.6%)approaches were used for the management of correctable complications.CONCLUSION Unilateral hypoplastic kidney in adults has various complications that range from urinary tract infections to death from septicemia.Diagnosis is mainly radiological and management is usually conservative or minimally invasive.展开更多
Hypoplastic left heart syndrome(HLHS)is a rare,complex,and incredibly foetal congenital heart disease.To decrease neonatal mortality,evolving HLHS(eHLHS)in pregnant women should be critically diagnosed as soon as poss...Hypoplastic left heart syndrome(HLHS)is a rare,complex,and incredibly foetal congenital heart disease.To decrease neonatal mortality,evolving HLHS(eHLHS)in pregnant women should be critically diagnosed as soon as possible.However,diagnosis is currently heavily dependent on skilled medical professionals using foetal cardiac ultrasound images,making it difficult to rapidly and easily examine for this disease.Herein,the authors propose a cost-effective deep learning framework for rapid diagnosis of eHLHS(RDeH),which we have named RDeH-Net.Briefly,the framework implements a coarseto-fine two-stage detection approach,with a structure classification network for 4D human foetal cardiac ultrasound images from various spatial and temporal domains,and a fine detection module with weakly-supervised localisation for high-precision nidus localisation and physician assistance.The experiments extensively compare the authors’network with other state-of-the-art methods on a 4D human foetal cardiac ultrasound image dataset and show two main benefits:(1)it achieved superior average accuracy of 99.37%on three categories of foetal ultrasound images from different cases;(2)it demonstrates visually fine detection performance with weakly supervised localisation.This framework could be used to accelerate the diagnosis of eHLHS,and hence significantly lessen reliance on experienced medical physicians.展开更多
Objective To discuss the operative techniques and results of coarctation resection plus aortoplasty with pulmonary autograft patch for coarctation of the aorta combined with hypoplastic aortic arch in infant. Methods ...Objective To discuss the operative techniques and results of coarctation resection plus aortoplasty with pulmonary autograft patch for coarctation of the aorta combined with hypoplastic aortic arch in infant. Methods Between May 2007 and Dec 2009,14 cases including 9 males and 5 females with coarctation of the aorta and hypoplastic aortic arch underwent coarctation resection plus aortoplasty with pulmonary autograft patch in展开更多
To the Editor:Bilateral medial medullary infarction(MMI)is a rare stroke subtype.[1]usually leads to quadriplegia,sensory disturbance,hypoglossal palsy,bulbar paralysis,etc.[2]We encountered a patient with rapidly pro...To the Editor:Bilateral medial medullary infarction(MMI)is a rare stroke subtype.[1]usually leads to quadriplegia,sensory disturbance,hypoglossal palsy,bulbar paralysis,etc.[2]We encountered a patient with rapidly progressive tetraparesis and diffusion-weighted imaging(DWI)exhibited a“heart appearance”sign in the bilateral ventral medulla.Computed tomography angiography(CTA)demonstrated that the left vertebral artery(VA)was hypoplastic and there was an atherosclerotic stenosis in the V4 segment.展开更多
Discrete element simulations of one-dimensional compression of breakable granular assemblies were performed to investigate the capability of the exponential compression equation suggested by Bauer.The relationship bet...Discrete element simulations of one-dimensional compression of breakable granular assemblies were performed to investigate the capability of the exponential compression equation suggested by Bauer.The relationship between the so-called solid hardness and the particle strength was studied so as to provide a physical background for the introduction of a time-dependent solid hardness.A hyperbolic flow rule,describing the relationship between the inclination of the strain path and the stress ratio during wetting,was proposed based on typical triaxial wetting experiments on two different rockfill materials.The flow rule was then extended and incorporated into the transformed stress based hypoplastic model to capture the direction of creep strains.Meanwhile,a new density factor was introduced to the extended model to take into account the dependence of the magnitude of creep strains on the packing density.The stiffness tensor given by the extended model was discussed and the flowchart for the integration of the constitutive equation was designed.The extended model was then embedded into a finite element program and used to simulate the triaxial compression and wetting experiments performed on the aforementioned rockfill materials.Good agreement between the model predictions and the measured results lends sufficient credibility to the extended model in reproducing the stress-stain behaviour under loading and the creep behaviour during wetting.The extended model and the finite element program were also used to investigate the deformation behaviour of an earth-rock dam at the end of construction and during first impounding.The familiar phenomena such as the wetting induced settlement of the upstream shell and the movement of the dam crest towards the upstream were successfully captured by the numerical model,which confirms the feasibility of applying the extended model to dam engineering in the future.展开更多
The wetting deformation of weathered rockfill materials has been attracting growing attention from both engineers and scientists.The importance of realistic predictions of wetting deformations for high earth and rockf...The wetting deformation of weathered rockfill materials has been attracting growing attention from both engineers and scientists.The importance of realistic predictions of wetting deformations for high earth and rockfill dams is a strong motivation to establish a suitable constitutive model.Recently,the hypoplastic constitutive model by Gudehus and Bauer was extended by introducing solid hardness depending on the state of weathering.The extended model takes into account the influence of the current density,the effective stress state,the rate of deformation,and the time dependent process of degradation of the solid hardness.In the present paper,the performance of this model is evaluated by comparing numerical simulations with experiments obtained from a water sensitive rockfill material.In particular,triaxial compression paths and creep deformation under deviatoric stress states are considered.Finally,the constitutive model proposed is used to study the influence of a degradation of the solid hardness on the long term behavior of a hypothetical fill dam.展开更多
This study presents numerical and experimental models for the analysis of the excavation of soft soils by means of a cutting tool.The computational model is constructed using an Updated Lagrangean(UL)velocity-based Fi...This study presents numerical and experimental models for the analysis of the excavation of soft soils by means of a cutting tool.The computational model is constructed using an Updated Lagrangean(UL)velocity-based Finite Element approach.A hypoplastic formu-lation is employed to describe the constitutive behavior of soft soils.Large displacements and deformations of the ground resulting from the cutting tool-soil interaction are handled by means of the Particle Finite Element method,characterized by a global re-meshing strat-egy and a boundary identification procedure called a-shape technique.The capabilities and performance of the proposed model are demonstrated through comparative analyses between experiments and simulations of cutting tool-soft soil interactions.The experiments are performed using an excavation device at Ruhr-Universita¨t Bochum(RUB),Germany.The main details concerning the setup and calibration and evolution of the measured draft forces are discussed.Selected computational results characterizing the cutting tool-soft soil interaction including the topology of the free surface,void ratio distribution ahead of the tool,spatio-temporal evolution of the reaction forces and abrasive wear behavior are evaluated.展开更多
The strength-dilatancy characteristics of frictional materials embraced in the hypoplastic model proposed by Gudehus and Bauer are investigated and compared with the revised model suggested by Huang.In the latter the ...The strength-dilatancy characteristics of frictional materials embraced in the hypoplastic model proposed by Gudehus and Bauer are investigated and compared with the revised model suggested by Huang.In the latter the deviatoric stress in the model by Gudehus and Bauer is replaced by a transformed stress according to the stress transformation technique proposed by Matsuoka.The flow rule,the failure state surface equation and the strengthdilatancy relationship embraced in both models are derived analytically.The performance of the two hypoplastic models in reproducing the relationship between the peak strength and the corresponding dilation rate under triaxial compression,plane compression and plane shearing are then extensively investigated and compared with experimental results and with the predictions made by particular classical stress-dilatancy theories.Numerical investigations show that the performance in reproducing the strength-dilatancy relationship is quite satisfactory under triaxial compression stress state in both models and the predictions made by the transformed stress based model are closer to the results obtained from classical stress-dilatancy theories for plane compression and plane shearing problems.展开更多
Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after birth.We present a clinical case of a successful surgical correction of a crit...Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after birth.We present a clinical case of a successful surgical correction of a critical aortic stenosis using a hybrid method applied in a newborn during the first day of life.The infant was diagnosed with a hypoplastic left heart complex with an intact atrial septum(aortic and mitral valves stenosis variant),that led to the cardiogenic shock and acute pulmonary edema.The procedure included bilateral banding of the pulmonary artery branches and atrioseptostomy with stenting of the interatrial septum.The surgery was performed through a median sternotomy.展开更多
In this paper, two different concepts for the constitutive modeling of the mechanical behavior of creep-sensitive rockfill materials are presented. Specifically, the performance of an extended generalized plasticity m...In this paper, two different concepts for the constitutive modeling of the mechanical behavior of creep-sensitive rockfill materials are presented. Specifically, the performance of an extended generalized plasticity model proposed by Wang is compared with a simplified version of the hypoplastic constitutive model for weathered rockfill materials proposed by Bauer. Both models can reflect the influence of the mean stress on the incremental stiffness, the peak friction angle, and the dilatancy angle. The so-called solid hardness defined for a continuum description and originally introduced by Bauer is embedded in both models. Hydrochemical, thermal, and mechanical weathering are usually caused by environmental changes and are taken into account in a phenomenological description with an irreversible and time-dependent degradation of the solid hardness. A degradation of the solid hardness is usually accompanied by creep deformation of the stressed rockfill material. It is shown that appropriate modeling of creep deformation requires at least a unified description of the interaction between the time-dependent process of degradation of the solid hardness and the stress state. In this context, the solid hardness can be understood as a key parameter for describing the evolution of the state of weathering of the rockfill material. Particular attention is also paid to the necessary procedure for determining the constitutive constants of the two different constitutive models. Finally, the performance of the two different constitutive models is demonstrated by comparing the results obtained from numerical simulations with experimental data from the creep-sensitive rockfill material.展开更多
Background:Patients with single ventricle anatomy are at increased risk of growth failure and malnutrition.Amongst cardiac centers,there is little standardization of feeding practices in this complex population.We hyp...Background:Patients with single ventricle anatomy are at increased risk of growth failure and malnutrition.Amongst cardiac centers,there is little standardization of feeding practices in this complex population.We hypothesized that initiation of our center’s preoperative feeding protocol would result in decreased gastrostomy tube(G-tube)use,decreased length of stay and would not result in increased Necrotizing Enterocolitis(NEC)rates.Methods:A single institution review of 52 patients who had undergone stage I single ventricle palliative repair was performed.Patient diagnoses were hypoplastic left heart syndrome(39%),atrioventricular canal(15%),and other(46%).Postoperative parameters such as time to goal feed and need for gastrostomy tube(G-tube)were compared among preoperatively fed and non-preoperatively fed groups.Time to goal feed was calculated as time from first postoperative enteral feed to goal volume of 100 mL/kg.Results:Of the 26 patients who met inclusion criteria for preoperative feeding,22 patients(85%)were fed prior to surgery.Cox proportional hazard ratio revealed that age at surgery(p=0.047)and being preoperatively fed(p=0.001)were associated with reaching goal feed sooner.Multivariable analysis revealed that being preoperatively fed made a patient twice as likely to reach goal feed sooner(p=0.047).Univariable logistic regression revealed that days on total parenteral nutrition(p=0.018),length of hospitalization(p=0.008),and time to 1st postoperative feed(p=0.020)were significantly associated with higher odds of needing a G-tube postoperatively.Multivariable logistic regression did not show any predictors of postoperative G-tube usage.However,there was a trend towards lower G-tube usage in the preoperatively fed group.Conclusions:Implementing a standardized preoperative feeding protocol in single ventricle neonates can result in significantly shorter time to goal feed in preoperatively fed patients.It is beneficial for institutions to begin implementing standard feeding protocols to improve nutrition and growth outcomes.展开更多
This paper aims at analyzing material-induced lateral pressure of RC cylinder silo in both static and dynamic condition using the finite element method( FEM). In the finite element software ABAQUS,concrete material is...This paper aims at analyzing material-induced lateral pressure of RC cylinder silo in both static and dynamic condition using the finite element method( FEM). In the finite element software ABAQUS,concrete material is modeled by concrete damaged plasticity model,and stored materials in silo is modeled by the hypoplastic theory.In terms of numerical model,shell elements( S4R) and solid elements( C3D8) are applied for model silo wall and stored materials respectively. The interaction between silo wall and stored materials is simulated by Coulomb friction model and penalty contact constrain provided by ABAQUS.The numerical results are verified with the existing experimental data that are designed to ensure the validation of such numerical model using FEM and it obtains good agreements between numerical results and experimental data. Then the material parameters are analyzed in both static and dynamic condition.According to the analysis,it is clear that critical friction angle,initial void ratio and minimum void ratio have an obvious effect on static lateral pressure while all the material parameters affect dynamic lateral pressure at different levels. In addition,differences of silo wall between elastic and plastic state are analyzed in dynamic condition. The numerical results show that it contributes to increasing dynamic pressure when silo wall enters into the plastic state. Finally,this paper discusses the time-history lateral pressure at different heights along silo wall,and analytical results indicate that larger acceleration values play main roles in producing the maximum lateral pressure at higher part of the silo wall.展开更多
文摘Hypoplastic left heart syndrome is a severe congenital defect involving underdeveloped left-sided cardiac structures,leading to significant mortality and morbidity.Prenatal diagnosis using fetal ultrasound and echocardiography enables early detection,family counseling,and improved clinical decision-making.Advanced prenatal interventions,such as fetal aortic valvuloplasty and atrial septostomy,show promise but require careful patient selection.A multidisciplinary approach involving obstetricians,neonatologists,and pediatric cardiologists is vital for effective management.Future directions include refining imaging techniques,such as three-dimensional ultrasound,cardiovascular magnetic resonance imaging,and exploring bioengineering solutions,stem cell therapies,and genetic research.These advancements aim to improve therapeutic options and address current limitations,including transplant scarcity and postoperative complications.Although surgical innovations have improved survival rates,challenges remain,including neurological risks and long-term hemodynamic issues.Ongoing research and technological advancements are essential to enhance outcomes and quality of life for hypoplastic left heart syndrome patients.
基金support provided by the Open Project Foundation for Key Laboratories of Universities in Fujian Province(KF-T18014)the Scientific Research Project of Shaanxi Coalfield Geology Group Co.,Ltd.(SMDZ-2019CX-7).
文摘The artificial ground-freezing method is the main technical means for the excavation of mines and tunnels through the water-rich sand layer,and the comprehensive understanding of the mechanical properties of frozen saturated sand and the stress-strain relationship under complex stress can provide important guidance.In this study,a series of true triaxial tests of frozen saturated sand samples were conducted.Combined with the test data,the effects of temperature and medium principal stress ratio(b)on the strength and deformation characteristics of frozen saturated sand are discussed.In addition,a cohesion tensor is introduced to the Wu-Lin hypoplastic model.A scalar value is used to characterize the effect of temperature on the strength of frozen soil.The defect that the original model cannot describe the tensile capacity of frozen soil under low stress conditions is clearly solved.In addition,the cumulative deformation state variable is introduced to improve the response performance of the model in triaxial compression tests.The hypoplastic model of frozen soil has shown good performance in simulating triaxial compression tests at different temperatures and medium principal stress ratios.
基金Projects(50479057, 50639060) supported by the National Natural Science Foundation of China
文摘An incrementally nonlinear hypoplastic constitutive model was introduced, which was developed without recourse to the concepts in elastoplasticity theory such as yield surface, plastic potential and the decomposition of the deformation into elastic and plastic parts. Triaxial drained tests on rockfill were conducted on a large scale triaxial apparatus under two types of stress paths, which were the stress paths of constant stress ratio and the complex stress paths with transitional features. Motivated by the effect of stress path, the Gudehus-Bauer hypoplastic model was improved by considering the parameter variations with different ratios of stress increment. Fitting parameter a presents a piecewise linear relationship with cosine of the slope angle θ determined by instantaneous stress path. The improved hypoplastic model can present peak stress increasing and volumetric strain changing from dilatancy to contractancy with the increase of transitional confining pressure σ3t and the decrease of slope angle θ of stress path. Compared with the test data, it is shown that the model is capable of fully considering the effect of stress path on rockfill.
文摘Objective:This study aimed to analyze and evaluate the results of mid-term follow-up after fetal pulmonary valvuloplasty(FPV)in fetuses with pulmonary atresia with intact ventricular septum(PA/IVS).Methods:From August 31,2018,to May 31,2019,seven fetuses with PA/IVS and hypoplastic right heart were included in this study.All underwent echocardiography by the same specialist and were operated on by the same team.Intervention and echocardiography data were collected,and changes in the associated indices noted during follow-up were analyzed.Results:All seven fetuses successfully underwent FPV.The median gestational age at FPV was 27.54 weeks.The average FPV procedural time was 6 min.Persistent bradycardia requiring treatment occurred in 4/7 procedures.Finally,five pregnancies were successfully delivered,and the other two were aborted.Compared to data before fetal cardiac interventions(FCI),tricuspid valve annulus diameter/mitral valve annulus diameter(TV/MV)and right ventricle diameter/left ventricle diameter(RV/LV)of all fetuses had progressively improved.The maximum tricuspid regurgitation velocity decreased from 4.60 m/s to 3.64 m/s.The average follow-up time was 30.40±2.05 months.During the follow-up period,the diameter of the tricuspid valve ring in five children continued to improve,and the development rate of the tricuspid valve was relatively obvious from 6 months to 1 year after birth.However,the development of the right ventricle after birth was relatively slow.It was discovered that there were individual variations in the development of the right ventricle during follow-up.Conclusion:The findings support the potential for the development of the right ventricle and tricuspid valve in fetuses with PA/IVS who underwent FCI.Development of the right ventricle and tricuspid valve does not occur synchronously during pregnancy.The right ventricle develops rapidly in utero,but the development of tricuspid valve is more apparent after birth than in utero.
文摘Background:Thromboembolic events are a cause of significant morbidity and mortality in the Fontan population.We previously reported on coagulation profile changes in a cohort of patients with hypoplastic left heart syndrome(HLHS)from Stage I through Fontan completion.In this report,we examine their clinical status,anticoagulation and incidence of thromboembolic events up to 20 years post Fontan.Methods:A retrospective chart review was conducted for twenty(20)surviving patients,from 1998 through December 2020.Patients who underwent orthotopic heart transplantation(OTx)were followed until their transplant.Patients who were found in the original study to have a factor VIII activity level>160%,were examined separately.Results:Most patients had follow-up within the last two years(2018–2020).Two patients underwent OTx and two patients died.Anticoagulation strategy was variable.Most patients were on aspirin monotherapy.There was a total of twelve thrombotic events(63.2%).These included six cerebrovascular accidents(two of which were fatal).Three out of the seven patients with elevated factor VIII activity from the original study had thromboembolic events(42.9%).Fontan complications were variable.Some degree of Fontan Associated Liver Disease was universal.Conclusions:This retrospective review of a group of single-ventricle patients post Fontan,illustrates the variability in anticoagulation therapy that exists in this population.A large proportion of patients suffered a significant thromboembolic event,including the patients with elevated factor VIII.Further investigation into the patients with elevated factor VIII may help determine whether a different antithrombotic strategy post Fontan would be beneficial.
基金supported by Jiangsu Province Postgraduate Practice Innovation Program(SJCX22_0766)Natural Science Foundation of Jiangsu Province(BK20231378)Leader of Geriatric Clinical Technology Application Research Project of Jiangsu Provincial Health Commission(LR2022002)。
文摘Background:Hypoplastic left heart syndrome(HLHS)is one of the most challenging congenital heart diseases in clinical treatment.In cardiac tissues,resident macrophages fulfill critical functions in maintaining a stable cardiac state and have strong regenerative capacity and organ specificity.However,the molecular mechanisms of macro-phages in HLHS remained unclear.Methods:Single-nucleus RNA sequencing(snRNA-seq)data of HLHS and healthy control(donors)samples obtained from the Gene Expression Omnibus(GEO)database were normalized and clustered using the Seurat package.The“FindMarkers”function was used to screen differentially expressed genes(DEGs)between the HLHS and donor groups and to analyze the functional enrichment of the set of genes of interest.Finally,cell-cell communication,pseudotime,and single-cell regulatory network inference and cluster-ing(SCENIC)analyses were used to study the mechanisms of macrophages in HLHS.Results:Based on the snRNA-seq data of HLHS and donors,we identified a total of 9 cell clusters,among which the proportion of macrophages was significantly less in the HLHS group than in the control group.Subdivision of macrophage subpopulations(Macrophages 1,2,and 3)showed that Macrophages 1 was mainly involved in nervous system development,angiogenesis,and apoptotic processes.In addition,analysis of communication between Macro-phages 1 and cardiomyocytes revealed that ligand-acceptor pairs such as GAS6/AXL,IL6,IGF1,THY1,and L1CAM were present only in the donor group.Finally,pesudotime and SCENIC analyses demonstrated that FOXO3 and ELF2 played a critical role for Macrophages 1 to maintain cardiac function in patients with HLHS.Conclusion:Our study improved the current understanding of the molecular mechanisms of macrophage devel-opment in HLHS,showing that manipulating the regulatory role of macrophages in the heart can be a novel treat-ment for HLHS.
文摘The diminutive aorta presents technical challenges in the palliation of hypoplastic left heart syndrome. Furthermore, aortic arch caliber changes and variable great vessel relationships can add complexity to an already difficult arch repair. We describe a technical approach that simplifies the aortic reconstruction and makes the procedure more generalizable and reproducible.
基金supported by grants from National Natural Science Foundation of China(NO 81770316)Mount Tai Scholarship ProjectQingdao Outstanding Health Professional Development Fund(2017)
文摘Background:Fetal balloon atrial septoplasty(BAS)is performed through the restrictive foramen ovale in fetal cases with established hypoplastic left heart syndrome(HLHS)and an intact or highly restrictive atrial septum(RAS).Methods:In the current report,we present a case of high position BAS in a fetus with HLHS/RAS.Results:Echocardiography confirmed an adequate atrial opening above the foramen ovale and fetal pleural effusion resolved spontaneously 1 day after the procedure.Conclusion:To the best of our knowledge,the creation of a high position hole in the thinner part of the atrial septum,instead of the restrictive tiny hole,has not been reported in fetal cases with HLHS/RAS.
文摘BACKGROUND Unilateral small-sized kidney is a radiological term referring to both the congenital and acquired causes of reduced kidney volume.However,the hypoplastic kidney may have peculiar clinical and radiological characterizations.AIM To evaluate the clinical presentations,complications,and management approaches of the radiologically diagnosed unilateral hypoplastic kidney.METHODS A retrospective review of the records of patients with a radiological diagnosis of unilateral hypoplastic kidney between July 2015 and June 2020 was done at Assiut Urology and Nephrology Hospital,Assiut University,Egypt.RESULTS A total of 33 cases were diagnosed to have unilateral hypoplastic kidney with a mean(range)age of 39.5±11.2(19-73)years.The main clinical presentation was loin pain(51.5%),stone passer(9.1%),anuria(12.1%),accidental discovery(15.2%),or manifestations of urinary tract infections(12.1%).Computed tomography was the most useful tool for radiological diagnosis.However,radioisotope scanning could be requested for verification of surgical interventions and nephrectomy decisions.Urolithiasis occurred in 23(69.7%)cases and pyuria was detected in 22(66.7%)cases where the infection was documented by culture and sensitivity test in 19 cases.While the non-complicated cases were managed by assurance only(12.1%),nephrectomy(15.2%)was performed for persistent complications.However,symptomatic(27.3%)and endoscopic(45.6%)approaches were used for the management of correctable complications.CONCLUSION Unilateral hypoplastic kidney in adults has various complications that range from urinary tract infections to death from septicemia.Diagnosis is mainly radiological and management is usually conservative or minimally invasive.
基金Natural Science Foundation of Chongqing Municipality,Grant/Award Numbers:2023NSCQLZX0045,CSTB2022NSCQ-MSX0436 and cstc202China Postdoctoral Science Foundation,Grant/Award Number:2023M740741+3 种基金National Natural Science Foundation of China,Grant/Award Numbers:62331008,62176027,62027827,62221005 and 622760Natural Science Foundation of Ningbo Municipality,Grant/Award Number:2023J280Zhejiang Province Postdoctoral Research Funding Project,Grant/Award Number:ZJ2023008Ningbo Key R&D Program,Grant/Award Number:2023Z231。
文摘Hypoplastic left heart syndrome(HLHS)is a rare,complex,and incredibly foetal congenital heart disease.To decrease neonatal mortality,evolving HLHS(eHLHS)in pregnant women should be critically diagnosed as soon as possible.However,diagnosis is currently heavily dependent on skilled medical professionals using foetal cardiac ultrasound images,making it difficult to rapidly and easily examine for this disease.Herein,the authors propose a cost-effective deep learning framework for rapid diagnosis of eHLHS(RDeH),which we have named RDeH-Net.Briefly,the framework implements a coarseto-fine two-stage detection approach,with a structure classification network for 4D human foetal cardiac ultrasound images from various spatial and temporal domains,and a fine detection module with weakly-supervised localisation for high-precision nidus localisation and physician assistance.The experiments extensively compare the authors’network with other state-of-the-art methods on a 4D human foetal cardiac ultrasound image dataset and show two main benefits:(1)it achieved superior average accuracy of 99.37%on three categories of foetal ultrasound images from different cases;(2)it demonstrates visually fine detection performance with weakly supervised localisation.This framework could be used to accelerate the diagnosis of eHLHS,and hence significantly lessen reliance on experienced medical physicians.
文摘Objective To discuss the operative techniques and results of coarctation resection plus aortoplasty with pulmonary autograft patch for coarctation of the aorta combined with hypoplastic aortic arch in infant. Methods Between May 2007 and Dec 2009,14 cases including 9 males and 5 females with coarctation of the aorta and hypoplastic aortic arch underwent coarctation resection plus aortoplasty with pulmonary autograft patch in
文摘To the Editor:Bilateral medial medullary infarction(MMI)is a rare stroke subtype.[1]usually leads to quadriplegia,sensory disturbance,hypoglossal palsy,bulbar paralysis,etc.[2]We encountered a patient with rapidly progressive tetraparesis and diffusion-weighted imaging(DWI)exhibited a“heart appearance”sign in the bilateral ventral medulla.Computed tomography angiography(CTA)demonstrated that the left vertebral artery(VA)was hypoplastic and there was an atherosclerotic stenosis in the V4 segment.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51179059,90815024)the Fund for Young Scientists in Nanjing Hydraulic Research Institute (Grant No. Y312004)
文摘Discrete element simulations of one-dimensional compression of breakable granular assemblies were performed to investigate the capability of the exponential compression equation suggested by Bauer.The relationship between the so-called solid hardness and the particle strength was studied so as to provide a physical background for the introduction of a time-dependent solid hardness.A hyperbolic flow rule,describing the relationship between the inclination of the strain path and the stress ratio during wetting,was proposed based on typical triaxial wetting experiments on two different rockfill materials.The flow rule was then extended and incorporated into the transformed stress based hypoplastic model to capture the direction of creep strains.Meanwhile,a new density factor was introduced to the extended model to take into account the dependence of the magnitude of creep strains on the packing density.The stiffness tensor given by the extended model was discussed and the flowchart for the integration of the constitutive equation was designed.The extended model was then embedded into a finite element program and used to simulate the triaxial compression and wetting experiments performed on the aforementioned rockfill materials.Good agreement between the model predictions and the measured results lends sufficient credibility to the extended model in reproducing the stress-stain behaviour under loading and the creep behaviour during wetting.The extended model and the finite element program were also used to investigate the deformation behaviour of an earth-rock dam at the end of construction and during first impounding.The familiar phenomena such as the wetting induced settlement of the upstream shell and the movement of the dam crest towards the upstream were successfully captured by the numerical model,which confirms the feasibility of applying the extended model to dam engineering in the future.
基金Support from the Ministry for Science and Technology in China and the Federal Ministry of Education,Science and Culture in Austria for the bilateral scientific-technological cooperation(Grant No.CN 01/2007)between Hohai University,Tsinghua University,Vienna University of Technology,University Innsbruck and Graz University of Technology is greatly acknowledgedChina Scholarship Council(CSC)
文摘The wetting deformation of weathered rockfill materials has been attracting growing attention from both engineers and scientists.The importance of realistic predictions of wetting deformations for high earth and rockfill dams is a strong motivation to establish a suitable constitutive model.Recently,the hypoplastic constitutive model by Gudehus and Bauer was extended by introducing solid hardness depending on the state of weathering.The extended model takes into account the influence of the current density,the effective stress state,the rate of deformation,and the time dependent process of degradation of the solid hardness.In the present paper,the performance of this model is evaluated by comparing numerical simulations with experiments obtained from a water sensitive rockfill material.In particular,triaxial compression paths and creep deformation under deviatoric stress states are considered.Finally,the constitutive model proposed is used to study the influence of a degradation of the solid hardness on the long term behavior of a hypothetical fill dam.
文摘This study presents numerical and experimental models for the analysis of the excavation of soft soils by means of a cutting tool.The computational model is constructed using an Updated Lagrangean(UL)velocity-based Finite Element approach.A hypoplastic formu-lation is employed to describe the constitutive behavior of soft soils.Large displacements and deformations of the ground resulting from the cutting tool-soil interaction are handled by means of the Particle Finite Element method,characterized by a global re-meshing strat-egy and a boundary identification procedure called a-shape technique.The capabilities and performance of the proposed model are demonstrated through comparative analyses between experiments and simulations of cutting tool-soft soil interactions.The experiments are performed using an excavation device at Ruhr-Universita¨t Bochum(RUB),Germany.The main details concerning the setup and calibration and evolution of the measured draft forces are discussed.Selected computational results characterizing the cutting tool-soft soil interaction including the topology of the free surface,void ratio distribution ahead of the tool,spatio-temporal evolution of the reaction forces and abrasive wear behavior are evaluated.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51209141 and 51179059)the Fund for Young Scientists in the Nanjing Hydraulic Research Institute(No.Y312004).
文摘The strength-dilatancy characteristics of frictional materials embraced in the hypoplastic model proposed by Gudehus and Bauer are investigated and compared with the revised model suggested by Huang.In the latter the deviatoric stress in the model by Gudehus and Bauer is replaced by a transformed stress according to the stress transformation technique proposed by Matsuoka.The flow rule,the failure state surface equation and the strengthdilatancy relationship embraced in both models are derived analytically.The performance of the two hypoplastic models in reproducing the relationship between the peak strength and the corresponding dilation rate under triaxial compression,plane compression and plane shearing are then extensively investigated and compared with experimental results and with the predictions made by particular classical stress-dilatancy theories.Numerical investigations show that the performance in reproducing the strength-dilatancy relationship is quite satisfactory under triaxial compression stress state in both models and the predictions made by the transformed stress based model are closer to the results obtained from classical stress-dilatancy theories for plane compression and plane shearing problems.
文摘Critical aortic valve stenosis in newborns is the cause of a severe clinical condition with the onset of symptoms during first hours after birth.We present a clinical case of a successful surgical correction of a critical aortic stenosis using a hybrid method applied in a newborn during the first day of life.The infant was diagnosed with a hypoplastic left heart complex with an intact atrial septum(aortic and mitral valves stenosis variant),that led to the cardiogenic shock and acute pulmonary edema.The procedure included bilateral banding of the pulmonary artery branches and atrioseptostomy with stenting of the interatrial septum.The surgery was performed through a median sternotomy.
基金supported by the CRSRI Open Research Program(Grant No.CKWV2016375/KY)the National Natural Science Foundation of China(Grants No.51609182,51379130,and 51209141)the Chinese Scholarship Council
文摘In this paper, two different concepts for the constitutive modeling of the mechanical behavior of creep-sensitive rockfill materials are presented. Specifically, the performance of an extended generalized plasticity model proposed by Wang is compared with a simplified version of the hypoplastic constitutive model for weathered rockfill materials proposed by Bauer. Both models can reflect the influence of the mean stress on the incremental stiffness, the peak friction angle, and the dilatancy angle. The so-called solid hardness defined for a continuum description and originally introduced by Bauer is embedded in both models. Hydrochemical, thermal, and mechanical weathering are usually caused by environmental changes and are taken into account in a phenomenological description with an irreversible and time-dependent degradation of the solid hardness. A degradation of the solid hardness is usually accompanied by creep deformation of the stressed rockfill material. It is shown that appropriate modeling of creep deformation requires at least a unified description of the interaction between the time-dependent process of degradation of the solid hardness and the stress state. In this context, the solid hardness can be understood as a key parameter for describing the evolution of the state of weathering of the rockfill material. Particular attention is also paid to the necessary procedure for determining the constitutive constants of the two different constitutive models. Finally, the performance of the two different constitutive models is demonstrated by comparing the results obtained from numerical simulations with experimental data from the creep-sensitive rockfill material.
文摘Background:Patients with single ventricle anatomy are at increased risk of growth failure and malnutrition.Amongst cardiac centers,there is little standardization of feeding practices in this complex population.We hypothesized that initiation of our center’s preoperative feeding protocol would result in decreased gastrostomy tube(G-tube)use,decreased length of stay and would not result in increased Necrotizing Enterocolitis(NEC)rates.Methods:A single institution review of 52 patients who had undergone stage I single ventricle palliative repair was performed.Patient diagnoses were hypoplastic left heart syndrome(39%),atrioventricular canal(15%),and other(46%).Postoperative parameters such as time to goal feed and need for gastrostomy tube(G-tube)were compared among preoperatively fed and non-preoperatively fed groups.Time to goal feed was calculated as time from first postoperative enteral feed to goal volume of 100 mL/kg.Results:Of the 26 patients who met inclusion criteria for preoperative feeding,22 patients(85%)were fed prior to surgery.Cox proportional hazard ratio revealed that age at surgery(p=0.047)and being preoperatively fed(p=0.001)were associated with reaching goal feed sooner.Multivariable analysis revealed that being preoperatively fed made a patient twice as likely to reach goal feed sooner(p=0.047).Univariable logistic regression revealed that days on total parenteral nutrition(p=0.018),length of hospitalization(p=0.008),and time to 1st postoperative feed(p=0.020)were significantly associated with higher odds of needing a G-tube postoperatively.Multivariable logistic regression did not show any predictors of postoperative G-tube usage.However,there was a trend towards lower G-tube usage in the preoperatively fed group.Conclusions:Implementing a standardized preoperative feeding protocol in single ventricle neonates can result in significantly shorter time to goal feed in preoperatively fed patients.It is beneficial for institutions to begin implementing standard feeding protocols to improve nutrition and growth outcomes.
基金Sponsored by the National Natural Science Foundation of China(Grant No.51478033,51179029)
文摘This paper aims at analyzing material-induced lateral pressure of RC cylinder silo in both static and dynamic condition using the finite element method( FEM). In the finite element software ABAQUS,concrete material is modeled by concrete damaged plasticity model,and stored materials in silo is modeled by the hypoplastic theory.In terms of numerical model,shell elements( S4R) and solid elements( C3D8) are applied for model silo wall and stored materials respectively. The interaction between silo wall and stored materials is simulated by Coulomb friction model and penalty contact constrain provided by ABAQUS.The numerical results are verified with the existing experimental data that are designed to ensure the validation of such numerical model using FEM and it obtains good agreements between numerical results and experimental data. Then the material parameters are analyzed in both static and dynamic condition.According to the analysis,it is clear that critical friction angle,initial void ratio and minimum void ratio have an obvious effect on static lateral pressure while all the material parameters affect dynamic lateral pressure at different levels. In addition,differences of silo wall between elastic and plastic state are analyzed in dynamic condition. The numerical results show that it contributes to increasing dynamic pressure when silo wall enters into the plastic state. Finally,this paper discusses the time-history lateral pressure at different heights along silo wall,and analytical results indicate that larger acceleration values play main roles in producing the maximum lateral pressure at higher part of the silo wall.
