The Effect of Atrial Septal Defect Closure on Cardiac Volumetric Changes in Adults, Transcatheter Versus Surgical Closure, a Pilot Cardiac Magnetic Resonance Study

Background:Closure of an atrial septal defect(ASD)reduces right-side heart volumes by abolishing shunting with simultaneous improvement of the left ventricle(LV)filling and functions due to ventricular interdependence,thereby improving symptoms.Furthermore,studies conducted on atrial volume changes after ASD closure are limited.Cardiac magnetic resonance(CMR)is considered as the gold standard method for measuring cardiac volume and mass.Objective:We aimed to study the effect of transcatheter and surgical closure of secundum ASD on cardiac volumes and systolic functions as well as the fate of tricuspid regurgitation(TR),using CMR analysis.Methods:We prospectively enrolled 30 adult patients with isolated secundum ASD who were referred to ASD closure.CMR evaluation of cardiac chambers indexed volumes,systolic function,myocardial mass index,and tricuspid regurgitant fraction were done at before and 6 months after closure.Results:RV volumes decreased in both groups when compared to baseline(p-value 0.001),the device group had more reduction in volumes and more improvement in RV function after closure(p-value 0.001)when compared to the surgical arm.The changes in the RV mass index were insignificant between both groups(p-value 0.31).Functional TR improved to the same extent in both groups.Left ventricular end diastolic volume index(LVEDVI)and LV mass index increased sig-nificantly in both groups when compared to baseline in both groups but with no difference between groups p-value 0.01),left ventricular end systolic volume index(LVESVI)changes were insignificant.LV systolic function improved in patients who underwent device closure only(63.53±3.85 vs.67.13±4.34,p-value 0.01).There was a significant reduction in right atrial(RA)volumes and an insignificant decrease in left atrial(LA)volumes,with no difference between groups.Conclusion:Transcatheter and surgical secundum ASD closure resulted in volumetric changes in some cardiac chambers with better improvement in bi-ventricular systolic function in the transcatheter arm and no difference in the TR reduction between the two groups at 6 months follow-up by CMR.

FORSAT:a 3D forest monitoring system for cover mapping and volumetric 3D change detection

A 3D forest monitoring system,called FORSAT(a satellite very high resolution image processing platform for forest assessment),was developed for the extraction of 3D geometric forest information from very high resolution(VHR)satellite imagery and the automatic 3D change detection.FORSAT is composed of two complementary tasks:(1)the geometric and radiometric processing of satellite optical imagery and digital surface model(DSM)reconstruction by using a precise and robust image matching approach specially designed for VHR satellite imagery,(2)3D surface comparison for change detection.It allows the users to import DSMs,align them using an advanced 3D surface matching approach and calculate the 3D differences and volume changes(together with precision values)between epochs.FORSAT is a single source and flexible forest information solution,allowing expert and non-expert remote sensing users to monitor forests in three and four(time)dimensions.The geometric resolution and thematic content of VHR optical imagery are sufficient for many forest information needs such as deforestation,clear-cut and fire severity mapping.The capacity and benefits of FORSAT,as a forest information system contributing to the sustainable forest management,have been tested and validated in case studies located in Austria,Switzerland and Spain.

Stress relaxation of warm frozen soil under drained or undrained conditions

To investigate the influence of drainage conditions on stress relaxation characteristics of warm frozen soil, a series of laboratory tests were carried out under drained and undrained conditions. The results indicate that confining pressure obviously influences the relaxation process of warm frozen soil. Under undrained condition, with increase in confining pressure, the critical relaxation du- ration tends to grow as well as instantaneous relaxation. But the relaxation rate is sensitive to confining pressure in the initial stage, and with further development, the effect tends to diminish. Under drained condition, the relaxation rate is greater than that under tmdrained condition in the initial stage but with the development of relaxation, the difference decreases. The volumetric defor- mation of warm frozen clay under drained condition is much larger than that under undrained condition.

The Use of Airborne LiDAR in Assessing Coastal Erosion in the Southeastern USA

Changes in sea level along the coastal southeastern United States(U.S.)influence the dynamic coastal response.In particular,the Southeast Coastal Network(SECN)of the National Park Service(NPS)has exhibited evidence of fluctuations in sea level which caused coastal erosion.Airborne LiDAR acquired from NOAA for Fort Matanzas National Monument,Fort Pulaski National Monument,Charles Pinckney National Historic Site,and Cape Lookout National Seashore were analyzed to identify changes in both elevation and the spatial volume of unconsolidated sedimentary material in the coastal southeast over time.Areas that exhibited an increase(deposited material)or decrease(eroded material)in elevation were mapped across the study area from 2006 to 2018.Results indicate a quasi-cyclic process where unconsolidated sediment distribution and the morphodynamic equilibrium changes with time.The coastal zones are steadily oscillating between the process of erosion and deposition affecting the coastal geomorphological dynamic.The use of LiDAR for evaluating coastal sustainability and resiliency due to this environmental phenomenon is clear.

Simultaneously realizing good volumetric entropy change and mechanical strength of La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)H_(y) plates

It is hard to get a high-strength La(Fe,Si)_(13)-based hydrides owing to the brittle feature of hydrides.In this work,we fabricated the La_(0.8)Ce_(0.2)Fe_(11.51)Mn_(0.19)Si_(1.3)plates through hot pressing at 1323 K for various time.Subsequently,the saturated hydrogenization is achieved at 593 K in H_2 atmosphere of 0.13 MPa for 210 min.The microstructure and magnetocaloric properties were investigated by an X-ray diffractometer,a scanning electron microscope and the Versa-Lab.Under magnetic fields of 0-2 T,the maximal volumetric entropy change is 91.4 mJ/(cm^(3)·K)at 297 K for the hydride plates.The hydride plate simultaneously has excellent mechanical properties with the maximum bending strength of 213 MPa,which suggest that the hot pressing followed by hydrogenation could be an effective route of fabricating La(Fe,Si)_(13)-based hydrides for the potential application in the magnetic refrigerator.