Needle fenestration of popliteal artery covered stent graft to salvage inadvertent stent misdeployment

Endovascular methods have transformed treatment of lower extremity peripheral arterial disease but can still present technical challenges. We report the case of a 69-year-old man with rest pain who underwent superficial femoral artery recanalization with covered stents. During completion angiography, the distal stent was discovered to have been misdeployed into an anterior geniculate branch overlying the behind-the-knee popliteal artery. Subsequently, an endovascular reentry device was used to fenestrate the stent posteriorly to enter the lumen of the popliteal artery. Cutting balloons were used to enlarge the fenestration in the stent fabric, with placement of an additional 6 × 50-mm covered stent bridging from the popliteal artery into the fenestrated misdeployed covered stent. Completion angiography demonstrated no evidence of distal embolization and patent two-vessel runoff. The patient had an uncomplicated recovery and at 2 years of follow-up remained asymptomatic with documented popliteal stent patency

Automatic detection of visual faults on photovoltaic modules using deep ensemble learning network

The present study proposes an ensemble-based deep neural network (DNN) model for autonomous detection of visual faults such as glass breakage, burn marks, snail trail, and discoloration, delamination on various photovoltaic modules (PVM). The proposed technique utilizes an image dataset captured by RGB (Red, Green, Blue) camera mounted on an unmanned aerial vehicle (UAV). In the first step, the images are preprocessed by deriving spatial and frequency domain features, such as discrete wavelet transform (DWT), texture, grey level co-occurrence matrix (GLCM), fast Fourier transform (FFT), and grey level difference method (GLDM). The processed images are inserted as input in the proposed ensemble-based deep neural network (DNN) model in order to detect any visual faults on the photovoltaic modules (PVM). The performance of the proposed model is evaluated through classification accuracy, receiver operating characteristic (ROC) curve, and confusion matrix. The results demonstrate that the proposed ensemble-based deep neural network (DNN) model, along with the random forest classifier, achieved a classification accuracy of 99.68% for detecting visual faults on the PV modules. To verify the performance and robustness of the proposed model, we compare our model’s results to those of various classification approaches described in the literature. The suggested approach is compatible with the commercial unmanned aerial vehicle (UAV) embedded flight management system for fault detection

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Wearable electronic devices with shape memory and stretchability for comfort fitting

Programmability will significantly increase the scope of wearable electronics in terms of their usage in various industries. It also provides comfort fitting to the customers as the shape of the device can be easily fixed depending on the needs of the customer. Comfort fitting also requires the device to be functional at normal body temperature of a human being (37°C). Significant research has been taking place in improving the stretchability of wearable electric devices. However, these devices immediately return to their original shape once the force (used to stretch the devices) is released. This leads to the development of discomfort in the users in whichever part of the body it is applied to. Hence, this report aims to address this critical issue by developing a new material that has the ability to hold its shape (programmable) when stretched and provide the necessary comfort to its users. This material has the ability to be programmed at body temperature which adds to the comfortability factor. This report studies the elastic and shape memory properties of this material and its potential usage in developing new wearable electric devices that are not only stretchable but also programmable for comfort fitting. A cost effective and easy fabrication process is also discussed to embed seemingly non-stretchable electronic substrates into these shape memory materials to fabricate stretchable electronic samples and their stretchability are also studied. Finally, this report discusses the future prospects for the advancement of wearable technology using such programmable materials.Doctor of Philosoph

Rebound control in multipass roll forming of cap-shaped parts based on segmental boundary optimization function

Bending angle is an important parameter in multi-pass roll forming. However, in actual manufacturing, there is still a lack of theoretical guidance; hence, rebound defects are commonly observed. In this paper, a bending angle distribution function with an optimized segmented boundary combination is proposed to improve the forming quality and reduce the rebound defects in multi-pass roll forming. For cap-shaped sheets, COPRA, a roll-bending simulation software, is used to investigate the bending angle distribution to optimize the process of cap-shaped roll-bending. Furthermore, the stress and strain distributions in the sheets after each forming pass is analyzed using finite element simulation. The influence law of different bending angle parameters on the quality of sheets is obtained. The finite element simulation is verified by comparing the experimental results of the change law of rebound defects of cap-shaped parts under different bending angle distribution conditions. Based on the segmented boundary combination of bending angle optimization functions, the stress and strain distributions in the sheets during roll-bending forming of the cap-shaped parts are improved, the rebound defects in the bending area are smaller, and the forming quality is better than the other bending angle distribution methods.Published versionThe authors would like to acknowledge the financial support provided by the National Science Foundation of China (Grant No. 51705295), Shandong Provincial Natural Science Foundation, China (ZR2018MEE022), and Support Program for Youth Innovation Technology in Colleges and Universities of Shandong Province (2019KJB015)

Experimental investigation on the factors affecting the quality of titanium alloy overhang via selective laser melting forming

Selective laser melting (SLM) technology has attracted wide attention because it can produce parts with complex shape or internal characteristics that are difficult to process in traditional ways. SLM process is very easy to produce dross formation and balling defects on the overhanging surface of titanium alloy when forming the overhanging characteristic structural parts, which makes the surface of the formed parts rough. Therefore, how to improve the forming quality of titanium alloy overhanging parts by adding material becomes an urgent problem to be solved. In this paper, the influence factors and mechanism of quality of titanium alloy suspension parts formed by SLM process are experimentally studied. Through analysis and comparison of forming parts under different geometric dimensions and process parameters, appropriate geometric dimensions and process parameters are obtained to improve the quality of forming parts. In terms of scanning strategy, a compound scanning path of “vertical island zoning + contour remelting” is put forward to solve the problems of stress concentration and dross formation on the overhanging surface. This strategy is based on vertical island zoning and improves the heat dissipation at the edge of the part by remelting the contour of the formed layer. The result shows that this method can effectively reduce the residual stress of the overhanging part and improve the dross formation phenomenon.The authors would like to acknowledge the financial support provided by the National Science Foundation of China (Grant No. 51705295), Shandong Provincial Natural Science Foundation, China (ZR2022ME032), and Support Program for Youth Innovation Technology in Colleges and Universities of Shandong Province (2019KJB015)

Needle fenestration of popliteal artery covered stent graft to salvage inadvertent stent misdeployment

Endovascular methods have transformed treatment of lower extremity peripheral arterial disease but can still present technical challenges. We report the case of a 69-year-old man with rest pain who underwent superficial femoral artery recanalization with covered stents. During completion angiography, the distal stent was discovered to have been misdeployed into an anterior geniculate branch overlying the behind-the-knee popliteal artery. Subsequently, an endovascular reentry device was used to fenestrate the stent posteriorly to enter the lumen of the popliteal artery. Cutting balloons were used to enlarge the fenestration in the stent fabric, with placement of an additional 6 × 50-mm covered stent bridging from the popliteal artery into the fenestrated misdeployed covered stent. Completion angiography demonstrated no evidence of distal embolization and patent two-vessel runoff. The patient had an uncomplicated recovery and at 2 years of follow-up remained asymptomatic with documented popliteal stent patency

Evolution of shore hardness under uniaxial tension/compression in body-temperature programmable elastic shape memory hybrids

Body-temperature programmable elastic shape memory hybrids (SMHs) have great potential for the comfortable fitting of wearable devices. Traditionally, shore hardness is commonly used in the characterization of elastic materials. In this paper, the evolution of shore hardness in body-temperature programmable elastic SMHs upon cyclic loading, and during the shape memory cycle, is systematically investigated. Upon cyclic loading, similar to the Mullins effect, significant softening appears, when the applied strain is over a certain value. On the other hand, after programming, in general, the measured hardness increases with increase in programming strain. However, for certain surfaces, the hardness decreases slightly and then increases rapidly. The underlying mechanism for this phenomenon is explained by the formation of micro-gaps between the inclusion and the matrix after programming. After heating, to melt the inclusions, all samples (both cyclically loaded and programmed) largely recover their original hardness.Published versio