229 research outputs found
Fast catheter segmentation from echocardiographic sequences based on segmentation from corresponding X-ray fluoroscopy for cardiac catheterization interventions
© 2014 IEEE. Echocardiography is a potential alternative to X-ray fluoroscopy in cardiac catheterization given its richness in soft tissue information and its lack of ionizing radiation. However, its small field of view and acoustic artifacts make direct automatic segmentation of the catheters very challenging. In this study, a fast catheter segmentation framework for echocardiographic imaging guided by the segmentation of corresponding X-ray fluoroscopic imaging is proposed. The complete framework consists of: 1) catheter initialization in the first X-ray frame; 2) catheter tracking in the rest of the X-ray sequence; 3) fast registration of corresponding X-ray and ultrasound frames; and 4) catheter segmentation in ultrasound images guided by the results of both X-ray tracking and fast registration. The main contributions include: 1) a Kalman filter-based growing strategy with more clinical data evalution; 2) a SURF detector applied in a constrained search space for catheter segmentation in ultrasound images; 3) a two layer hierarchical graph model to integrate and smooth catheter fragments into a complete catheter; and 4) the integration of these components into a system for clinical applications. This framework is evaluated on five sequences of porcine data and four sequences of patient data comprising more than 3000 X-ray frames and more than 1000 ultrasound frames. The results show that our algorithm is able to track the catheter in ultrasound images at 1.3 s per frame, with an error of less than 2 mm. However, although this may satisfy the accuracy for visualization purposes and is also fast, the algorithm still needs to be further accelerated for real-time clinical applications
Comparative venom gland transcriptome analysis of the scorpion Lychas mucronatus reveals intraspecific toxic gene diversity and new venomous components
<p>Abstract</p> <p>Background</p> <p><it>Lychas mucronatus </it>is one scorpion species widely distributed in Southeast Asia and southern China. Anything is hardly known about its venom components, despite the fact that it can often cause human accidents. In this work, we performed a venomous gland transcriptome analysis by constructing and screening the venom gland cDNA library of the scorpion <it>Lychas mucronatus </it>from Yunnan province and compared it with the previous results of Hainan-sourced <it>Lychas mucronatus</it>.</p> <p>Results</p> <p>A total of sixteen known types of venom peptides and proteins are obtained from the venom gland cDNA library of Yunnan-sourced <it>Lychas mucronatus</it>, which greatly increase the number of currently reported scorpion venom peptides. Interestingly, we also identified nineteen atypical types of venom molecules seldom reported in scorpion species. Surprisingly, the comparative transcriptome analysis of Yunnan-sourced <it>Lychas mucronatus </it>and Hainan-sourced <it>Lychas mucronatus </it>indicated that enormous diversity and vastly abundant difference could be found in venom peptides and proteins between populations of the scorpion <it>Lychas mucronatus </it>from different geographical regions.</p> <p>Conclusions</p> <p>This work characterizes a large number of venom molecules never identified in scorpion species. This result provides a comparative analysis of venom transcriptomes of the scorpion <it>Lychas mucronatus </it>from different geographical regions, which thoroughly reveals the fact that the venom peptides and proteins of the same scorpion species from different geographical regions are highly diversified and scorpion evolves to adapt a new environment by altering the primary structure and abundance of venom peptides and proteins.</p
A Scorpion Defensin BmKDfsin4 Inhibits Hepatitis B Virus Replication in Vitro
Hepatitis B virus (HBV) infection is a major worldwide health problem which can cause
acute and chronic hepatitis and can significantly increase the risk of liver cirrhosis and primary
hepatocellular carcinoma (HCC). Nowadays, clinical therapies of HBV infection still mainly rely on
nucleotide analogs and interferons, the usage of which is limited by drug-resistant mutation or side
effects. Defensins had been reported to effectively inhibit the proliferation of bacteria, fungi, parasites
and viruses. Here, we screened the anti-HBV activity of 25 scorpion-derived peptides most recently
characterized by our group. Through evaluating anti-HBV activity and cytotoxicity, we found that
BmKDfsin4, a scorpion defensin with antibacterial and Kv1.3-blocking activities, has a comparable
high inhibitory rate of both HBeAg and HBsAg in HepG2.2.15 culture medium and low cytotoxicity
to HepG2.2.15. Then, our experimental results further showed that BmKDfsin4 can dose-dependently
decrease the production of HBV DNA and HBV viral proteins in both culture medium and cell lysate.
Interestingly, BmKDfsin4 exerted high serum stability. Together, this study indicates that the scorpion
defensin BmKDfsin4 also has inhibitory activity against HBV replication along with its antibacterial
and potassium ion channel Kv1.3-blocking activities, which shows that BmKDfsin4 is a uniquely
multifunctional defensin molecule. Our work also provides a good molecule material which will be
used to investigate the link or relationship of its antiviral, antibacterial and ion channel–modulating
activities in the future
Directive Emission Obtained by Coordinate Transformation
We use coordinate transformation theory to realize substrates that can modify
the emission of an embedded source. Simulation results show that with proper
transformation functions the energy radiated by a source embedded in these
space variant media will be concentrated in a narrow beam. The thickness of the
slab achieved with our transformations will no longer be restricted by the
evanescent modes and the source can be placed at any position along the
boundary of the substrate without affecting the radiation pattern. We also
discuss the case where reduced parameters are used, which still performs well
and is physically realizable.Comment: 15 pages, 5 figure
Architecture engineering of carbonaceous anodes for high‐rate potassium‐ion batteries
The limited lithium resource in earth's crust has stimulated the pursuit of alternative energy storage technologies to lithium‐ion battery. Potassium‐ion batteries (KIBs) are regarded as a kind of promising candidate for large‐scale energy storage owing to the high abundance and low cost of potassium resources. Nevertheless, further development and wide application of KIBs are still challenged by several obstacles, one of which is their fast capacity deterioration at high rates. A considerable amount of effort has recently been devoted to address this problem by developing advanced carbonaceous anode materials with diverse structures and morphologies. This review presents and highlights how the architecture engineering of carbonaceous anode materials gives rise to high‐rate performances for KIBs, and also the beneficial conceptions are consciously extracted from the recent progress. Particularly, basic insights into the recent engineering strategies, structural innovation, and the related advances of carbonaceous anodes for high‐rate KIBs are under specific concerns. Based on the achievements attained so far, a perspective on the foregoing, and proposed possible directions, and avenues for designing high‐rate anodes, are presented finally
Human Performance Modeling and Rendering via Neural Animated Mesh
We have recently seen tremendous progress in the neural advances for
photo-real human modeling and rendering. However, it's still challenging to
integrate them into an existing mesh-based pipeline for downstream
applications. In this paper, we present a comprehensive neural approach for
high-quality reconstruction, compression, and rendering of human performances
from dense multi-view videos. Our core intuition is to bridge the traditional
animated mesh workflow with a new class of highly efficient neural techniques.
We first introduce a neural surface reconstructor for high-quality surface
generation in minutes. It marries the implicit volumetric rendering of the
truncated signed distance field (TSDF) with multi-resolution hash encoding. We
further propose a hybrid neural tracker to generate animated meshes, which
combines explicit non-rigid tracking with implicit dynamic deformation in a
self-supervised framework. The former provides the coarse warping back into the
canonical space, while the latter implicit one further predicts the
displacements using the 4D hash encoding as in our reconstructor. Then, we
discuss the rendering schemes using the obtained animated meshes, ranging from
dynamic texturing to lumigraph rendering under various bandwidth settings. To
strike an intricate balance between quality and bandwidth, we propose a
hierarchical solution by first rendering 6 virtual views covering the performer
and then conducting occlusion-aware neural texture blending. We demonstrate the
efficacy of our approach in a variety of mesh-based applications and
photo-realistic free-view experiences on various platforms, i.e., inserting
virtual human performances into real environments through mobile AR or
immersively watching talent shows with VR headsets.Comment: 18 pages, 17 figure
SdPI, The First Functionally Characterized Kunitz-Type Trypsin Inhibitor from Scorpion Venom
Background: Kunitz-type venom peptides have been isolated from a wide variety of venomous animals. They usually have protease inhibitory activity or potassium channel blocking activity, which by virtue of the effects on predator animals are essential for the survival of venomous animals. However, no Kunitz-type peptides from scorpion venom have been functionally characterized. Principal Findings: A new Kunitz-type venom peptide gene precursor, SdPI, was cloned and characterized from a venom gland cDNA library of the scorpion Lychas mucronatus. It codes for a signal peptide of 21 residues and a mature peptide of 59 residues. The mature SdPI peptide possesses a unique cysteine framework reticulated by three disulfide bridges, different from all reported Kunitz-type proteins. The recombinant SdPI peptide was functionally expressed. It showed trypsin inhibitory activity with high potency (Ki = 1.6610 27 M) and thermostability. Conclusions: The results illustrated that SdPI is a potent and stable serine protease inhibitor. Further mutagenesis and molecular dynamics simulation revealed that SdPI possesses a serine protease inhibitory active site similar to other Kunitztype venom peptides. To our knowledge, SdPI is the first functionally characterized Kunitz-type trypsin inhibitor derive
Test of Perfomance ERK Hybrid Dryer with Biomass Furnace as Additional Heating System for Nutmeg Seed (Myristica SP.) Drying
Conventional drying depend on the weather. It was caused agricultural product damaged, and moldy attack. So we need hybrid dryer with a source of radiation and solar biomass to continuous drying and can be controlled.The aims of this research is test performance of ERK hybrid dryer to drying the nutmeg seed during the drying process. Experiments were conducted to determine the distribution of temperature in the dryer in condition with no material and material conditions. Input of energy derived from biomass combustion in the furnace (evening) and combination of biomass and radiation (during the day). Measurements of temperature and RH using a thermocouple CC and alcohol thermometer. Temperature and RH to be measured include temperature and RH in dryer with several measurement points representing the up, middle , bottom and inlet temperature, outlet temperature and ambient temperature measurements at intervals of 30 minutes. The results showed average temperature ranges between 42 ° C - 51 ° C and RH ranged between 50.96 % -55.65 % . Time of drying is used to dry nutmeg from the initial moisture content from 80.72 % wb to 9.67 % wb is 52 hours with an average drying rate is 7.8 % db / hour . The total energy used to heat and vaporize materials,water that is 290 499.9 kJ. Efficiency of drying system 8.63% and energy of drying required to water evaporated is 28520.62 kJ / kg. The result quality of product obtained color of nutmeg generally more uniform
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