118 research outputs found
The Research on Operation of Obstructed Total Anomalous Pulmonary Venous Connection in Neonates
Objectives. Total anomalous pulmonary venous connection (TAPVC) is a rare congenital heart disease. This study aimed to evaluate the outcomes of TAPVC repair in neonates, controlling for anatomic subtypes and surgical techniques. Methods. Between 1997 and 2013, 88 patients (median age: 16 days) underwent repair for supracardiac (31), cardiac (18), infracardiac (36), or mixed (3) TAPVC. All the patients underwent emergency operation due to obstructed drainage. Supracardiac and infracardiac TAPVC repair included a side-to-side anastomosis between the pulmonary venous confluence and left atrium. Coronary sinus unroofing was preferred for cardiac TAPVC repair. Results. The early mortality rate was 2.3% (2/88 patients). The echocardiogram showed no obstruction in the pulmonary vein anastomosis, and flow rate was 1.1–1.42 m/s in the 3-year follow-up period. Conclusions. The accurate preoperative diagnosis, improved protection of heart function, use of pulmonary vein tissue to anastomose and avoid damage of the pulmonary vein, and delayed sternum closure can reduce the risk of mortality. The preoperative severity of pulmonary vein obstruction, the timing of the emergency operation, and infracardiac or mixed-type TAPVC can affect prognosis. Using our surgical technique, the TAPVC mortality among our patients was gradually reduced with remarkable results. However, careful monitoring of the patient with pulmonary vein restenosis and the timing and method of reoperation should also be given importance
Data Driven Prediction Architecture for Autonomous Driving and its Application on Apollo Platform
Autonomous Driving vehicles (ADV) are on road with large scales. For safe and
efficient operations, ADVs must be able to predict the future states and
iterative with road entities in complex, real-world driving scenarios. How to
migrate a well-trained prediction model from one geo-fenced area to another is
essential in scaling the ADV operation and is difficult most of the time since
the terrains, traffic rules, entities distributions, driving/walking patterns
would be largely different in different geo-fenced operation areas. In this
paper, we introduce a highly automated learning-based prediction model
pipeline, which has been deployed on Baidu Apollo self-driving platform, to
support different prediction learning sub-modules' data annotation, feature
extraction, model training/tuning and deployment. This pipeline is completely
automatic without any human intervention and shows an up to 400\% efficiency
increase in parameter tuning, when deployed at scale in different scenarios
across nations.Comment: Accepted by the 31st IEEE Intelligent Vehicles Symposium (2020
FPM-WSI: Fourier ptychographic whole slide imaging via feature-domain backdiffraction
Fourier ptychographic microscopy (FPM), characterized by high-throughput
computational imaging, theoretically provides a cunning solution to the
trade-off between spatial resolution and field of view (FOV), which has a
promising prospect in the application of digital pathology. However, block
reconstruction and then stitching has currently become an unavoidable procedure
due to vignetting effects. The stitched image tends to present color
inconsistency in different image segments, or even stitching artifacts. In
response, we reported a computational framework based on feature-domain
backdiffraction to realize full-FOV, stitching-free FPM reconstruction.
Different from conventional algorithms that establish the loss function in the
image domain, our method formulates it in the feature domain, where effective
information of images is extracted by a feature extractor to bypass the
vignetting effect. The feature-domain error between predicted images based on
estimation of model parameters and practically captured images is then
digitally diffracted back through the optical system for complex amplitude
reconstruction and aberration compensation. Through massive simulations and
experiments, the method presents effective elimination of vignetting artifacts,
and reduces the requirement of precise knowledge of illumination positions. We
also found its great potential to recover the data with a lower overlapping
rate of spectrum and to realize automatic blind-digital refocusing without a
prior defocus distance
Domain size and charge defects on the polarization switching of antiferroelectric domains
The switching behavior of antiferroelectric domain structures under the
applied electric field is not fully understood. In this work, by using the
phase field simulation, we have studied the polarization switching property of
antiferroelectric domains. Our results indicate that the ferroelectric domains
nucleate preferably at the boundaries of the antiferroelectric domains, and
antiferroelectrics with larger initial domain sizes possess a higher coercive
electric field as demonstrated by hysteresis loops. Moreover, we introduced
charge defects into the sample and numerically investigated their influence. It
is also shown that charge defects can induce local ferroelectric domains, which
could suppress the saturation polarization and narrow the enclosed area of the
hysteresis loop. Our results give insights into understanding antiferroelectric
phase transformation and optimizing the energy storage property in experiments
On the strengthening and embrittlement mechanisms of an additively manufactured Nickel-base superalloy
The γ′ phase strengthened Nickel-base superalloy is one of the most significant dual-phase alloy systems for high-temperature engineering applications. The tensile properties of laser powder-bed-fused IN738LC superalloy in the as-built state have been shown to have both good strength and ductility compared with its post-thermal treated state. A microstructural hierarchy composed of weak texture, sub-micron cellular structures and dislocation cellular walls was promoted in the as-built sample. After post-thermal treatment, the secondary phase γ′ precipitated with various size and fraction depending on heat treatment process. For room-temperature tensile tests, the dominated deformation mechanism is planar slip of dislocations in the as-built sample while dislocations bypassing the precipitates via Orowan looping in the γ′ strengthened samples. The extraordinary strengthening effect due to the dislocation substructure in the as-built sample provides an addition of 372 MPa in yield strength. The results of our calculation are in agreement with experimental yield strength for all the three different conditions investigated. Strikingly, the γ′ strengthened samples have higher work hardening rate than as-built sample but encounter premature failure. Experimental evidence shows that the embrittlement mechanism in the γ′ strengthened samples is caused by the high dislocation hardening of the grain interior region, which reduces the ability to accommodate further plastic strain and leads to premature intergranular cracking. On the basis of these results, the strengthening micromechanism and double-edge effect of strength and ductility of Nickel-base superalloy is discussed in detail
Cyclic Deformation Behavior of Additive-Manufactured IN738LC Superalloys from Virgin and Reused Powders
In laser powder bed fusion (L-PBF), most powders are not melted in the chamber and collected after the printing process. Powder reuse is appreciable without sacrificing the mechanical properties of target components. To understand the influences of powder reuse on mechanical performance, a nickel-based superalloy, IN738LC, was investigated. Powder morphology, microstructure and chemical compositions of virgin and reused powders were characterized. An increase in oxygen content, generally metallic oxides, was located on the surface of powders. Monotonic tensile and cyclic fatigue were tested. Negligible deterioration in strength and tensile ductility were found, while scattered fatigue performance with regard to fatigue life was shown. Deformation and fatigue crack propagation mechanisms were discussed for describing the powder degradation effects
Using polysaccharides for the enhancement of functionality of foods: A review
peer-reviewedBackground:
Flavor, taste and functional ingredients are important ingredients of food, but they are easily lost or react during heating and are not stable. Carbohydrate-carbohydrate interactions (CCIs) and carbohydrate-protein interactions (CPIs) are involved in a variety of regulatory biological processes in nature, including cell differentiation, proliferation, adhesion, inflammation and immune responses. Polysaccharides have high molecular weights and many intramolecular hydrogen bonds, can be easily modified chemically and biochemically to enhance bioadhesive and biostability of tissues. Therefore, polysaccharides are the foundation for building complex and stable biosystems that are non-toxic with highydrophilicity and easily biodegradable.
Scope and approach:
In this review, we summarize the principles and applications of polysaccharide delivery systems in a variety of foods.
Key findings and conclusions:
This review focuses on the self-assembly of carbohydrates with complex structures and discusses the latest advances in self-assembly systems. The host-guest complexes formed by polyvalent sugar conjugates have the potential to provide, control or target delivery or release systems. They can also extend the shelf life of food and prevent oxidation and isomerization during food storage. Moreover, very few studies have outlined a comprehensive overview of the use of various types of food polysaccharide matrixes for the assembly and protection of food ingredients, which is a very important area for further study
- …