12,237 research outputs found
Volumetric Cell-and-Portal Generation
International audienceWe present an algorithm to generate a cell-and-portal decomposition of general indoor scenes. The method is an adaptation of the 3D watershed transform, computed on a distance-to-geometry sampled field. The watershed is processed using a flooding analogy in the distance field space. Flooding originates from local minima, each minimum producing a region. Portals are built as needed to avoid the merging of regions during their growth. As a result, the cell it deals with parametric curves, implicit surfaces, volumetric data and polygon soups in a unified way
Shape Animation with Combined Captured and Simulated Dynamics
We present a novel volumetric animation generation framework to create new
types of animations from raw 3D surface or point cloud sequence of captured
real performances. The framework considers as input time incoherent 3D
observations of a moving shape, and is thus particularly suitable for the
output of performance capture platforms. In our system, a suitable virtual
representation of the actor is built from real captures that allows seamless
combination and simulation with virtual external forces and objects, in which
the original captured actor can be reshaped, disassembled or reassembled from
user-specified virtual physics. Instead of using the dominant surface-based
geometric representation of the capture, which is less suitable for volumetric
effects, our pipeline exploits Centroidal Voronoi tessellation decompositions
as unified volumetric representation of the real captured actor, which we show
can be used seamlessly as a building block for all processing stages, from
capture and tracking to virtual physic simulation. The representation makes no
human specific assumption and can be used to capture and re-simulate the actor
with props or other moving scenery elements. We demonstrate the potential of
this pipeline for virtual reanimation of a real captured event with various
unprecedented volumetric visual effects, such as volumetric distortion,
erosion, morphing, gravity pull, or collisions
Portal vein thrombosis and arterioportal shunts : effects on tumor response after chemoembolization of hepatocellular carcinoma
AIM: To evaluate the effect of portal vein thrombosis and arterioportal shunts on local tumor response in advanced cases of unresectable hepatocellular carcinoma treated by transarterial chemoembolization.
METHODS: A retrospective study included 39 patients (mean age: 66.4 years, range: 45-79 years, SD: 7) with unresectable hepatocellular carcinoma (HCC) who were treated with repetitive transarterial chemoembolization (TACE) in the period between March 2006 and October 2009. The effect of portal vein thrombosis (PVT) (in 19 out of 39 patients), the presence of arterioportal shunt (APS) (in 7 out of 39), the underlying liver pathology, Child-Pugh score, initial tumor volume, number of tumors and tumor margin definition on imaging were correlated with the local tumor response after TACE. The initial and end therapy local tumor responses were evaluated according to the response evaluation criteria in solid tumors (RECIST) and magnetic resonance imaging volumetric measurements.
RESULTS: The treatment protocols were well tolerated by all patients with no major complications. Local tumor response for all patients according to RECIST criteria were partial response in one patient (2.6%), stable disease in 34 patients (87.1%), and progressive disease in 4 patients (10.2%). The MR volumetric measurements showed that the PVT, APS, underlying liver pathology and tumor margin definition were statistically significant prognostic factors for the local tumor response (P = 0.018, P = 0.008, P = 0.034 and P = 0.001, respectively). The overall 6-, 12- and 18-mo survival rates from the initial TACE were 79.5%, 37.5% and 21%, respectively.
CONCLUSION: TACE may be exploited safely for palliative tumor control in patients with advanced unresectable HCC; however, tumor response is significantly affected by the presence or absence of PVT and APS
Tumour cell labelling by magnetic nanoparticles with determination of intracellular iron content and spatial distribution of the intracellular iron
Abstract: Magnetically labelled cells are used for in vivo cell tracking by MRI, used for the clinical translation of cell-base therapies. Studies involving magnetic labelled cells may include separation of labelled cells, targeted delivery and controlled release of drugs, contrast enhanced MRI and magnetic hyperthermia for the in situ ablation of tumours. Dextran-coated super-paramagnetic iron oxide (SPIO) ferumoxides are used clinically as an MR contrast agents primarily for hepatic imaging. The material is also widely used for in vitro cell labelling, as are other SPIO-based particles. Our results on the uptake by human cancer cell lines of ferumoxides indicate that electroporation in the presence of protamine sulphate (PS) results in rapid high uptake of SPIO nanoparticles (SPIONs) by parenchymal tumour cells without significant impairment of cell viability. Quantitative determination of cellular iron uptake performed by colorimetric assay is in agreement with data from the literature. These results on intracellular iron content together with the intracellular distribution of SPIONs by magnetic force microscopy (MFM) following in vitro uptake by parenchymal tumour cells confirm the potential of this technique for clinical tumour cell detection and destruction
VisIVOWeb: A WWW Environment for Large-Scale Astrophysical Visualization
This article presents a newly developed Web portal called VisIVOWeb that aims
to provide the astrophysical community with powerful visualization tools for
large-scale data sets in the context of Web 2.0. VisIVOWeb can effectively
handle modern numerical simulations and real-world observations. Our
open-source software is based on established visualization toolkits offering
high-quality rendering algorithms. The underlying data management is discussed
with the supported visualization interfaces and movie-making functionality. We
introduce VisIVOWeb Network, a robust network of customized Web portals for
visual discovery, and VisIVOWeb Connect, a lightweight and efficient solution
for seamlessly connecting to existing astrophysical archives. A significant
effort has been devoted for ensuring interoperability with existing tools by
adhering to IVOA standards. We conclude with a summary of our work and a
discussion on future developments
VisIVO - Integrated Tools and Services for Large-Scale Astrophysical Visualization
VisIVO is an integrated suite of tools and services specifically designed for
the Virtual Observatory. This suite constitutes a software framework for
effective visual discovery in currently available (and next-generation) very
large-scale astrophysical datasets. VisIVO consists of VisiVO Desktop - a stand
alone application for interactive visualization on standard PCs, VisIVO Server
- a grid-enabled platform for high performance visualization and VisIVO Web - a
custom designed web portal supporting services based on the VisIVO Server
functionality. The main characteristic of VisIVO is support for
high-performance, multidimensional visualization of very large-scale
astrophysical datasets. Users can obtain meaningful visualizations rapidly
while preserving full and intuitive control of the relevant visualization
parameters. This paper focuses on newly developed integrated tools in VisIVO
Server allowing intuitive visual discovery with 3D views being created from
data tables. VisIVO Server can be installed easily on any web server with a
database repository. We discuss briefly aspects of our implementation of VisiVO
Server on a computational grid and also outline the functionality of the
services offered by VisIVO Web. Finally we conclude with a summary of our work
and pointers to future developments
Безопасность и качество пищевых продуктов = Practical Food Safety and Food Quality : практикум
Даны описания практических и лабораторных работ, проводимых в рамках курсов «Международные стандарты и безопасность продуктов питания» и «Контроль качества биотехнологических продуктов». Задания сопровождаются подробными комментариями. Используются активные формы обучения, такие как работа в команде, игровые технологии и пр. Для иностранных и российских студентов, обучающихся на английском языке, изучающих пищевую биотехнологию, контроль качества и безопасность пищевых продуктов
Towards synthetic biological approaches to resource utilization on space missions.
This paper demonstrates the significant utility of deploying non-traditional biological techniques to harness available volatiles and waste resources on manned missions to explore the Moon and Mars. Compared with anticipated non-biological approaches, it is determined that for 916 day Martian missions: 205 days of high-quality methane and oxygen Mars bioproduction with Methanobacterium thermoautotrophicum can reduce the mass of a Martian fuel-manufacture plant by 56%; 496 days of biomass generation with Arthrospira platensis and Arthrospira maxima on Mars can decrease the shipped wet-food mixed-menu mass for a Mars stay and a one-way voyage by 38%; 202 days of Mars polyhydroxybutyrate synthesis with Cupriavidus necator can lower the shipped mass to three-dimensional print a 120 m(3) six-person habitat by 85% and a few days of acetaminophen production with engineered Synechocystis sp. PCC 6803 can completely replenish expired or irradiated stocks of the pharmaceutical, thereby providing independence from unmanned resupply spacecraft that take up to 210 days to arrive. Analogous outcomes are included for lunar missions. Because of the benign assumptions involved, the results provide a glimpse of the intriguing potential of 'space synthetic biology', and help focus related efforts for immediate, near-term impact
Adenosine-mono-phosphate-activated protein kinase-independent effects of metformin in T cells
The anti-diabetic drug metformin regulates T-cell responses to immune activation and is proposed to function by regulating the energy-stress-sensing adenosine-monophosphate-activated protein kinase (AMPK). However, the molecular details of how metformin controls T cell immune responses have not been studied nor is there any direct evidence that metformin acts on T cells via AMPK. Here, we report that metformin regulates cell growth and proliferation of antigen-activated T cells by modulating the metabolic reprogramming that is required for effector T cell differentiation. Metformin thus inhibits the mammalian target of rapamycin complex I signalling pathway and prevents the expression of the transcription factors c-Myc and hypoxia-inducible factor 1 alpha. However, the inhibitory effects of metformin on T cells did not depend on the expression of AMPK in T cells. Accordingly, experiments with metformin inform about the importance of metabolic reprogramming for T cell immune responses but do not inform about the importance of AMPK
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