20 research outputs found
In situ characterization of the decomposition behavior of Mg(BH4)(2) by X-ray Raman scattering spectroscopy
We present an in situ study of the thermal decomposition of Mg(BH4)(2) in a hydrogen atmosphere of up to 4 bar and up to 500 degrees C using X-ray Raman scattering spectroscopy at the boron K-edge and the magnesium L2,3-edges. The combination of the fingerprinting analysis of both edges yields detailed quantitative information on the reaction products during decomposition, an issue of crucial importance in determining whether Mg(BH4)(2) can be used as a next-generation hydrogen storage material. This work reveals the formation of reaction intermediate(s) at 300 degrees C, accompanied by a significant hydrogen release without the occurrence of stable boron compounds such as amorphous boron or MgB12H12. At temperatures between 300 degrees C and 400 degrees C, further hydrogen release proceeds via the formation of higher boranes and crystalline MgH2. Above 400 degrees C, decomposition into the constituting elements takes place. Therefore, at moderate temperatures, Mg(BH4)(2) is shown to be a promising high-density hydrogen storage material with great potential for reversible energy storage applications.Peer reviewe
Cross-species comparison of aCGH data from mouse and human BRCA1- and BRCA2-mutated breast cancers
Background: Genomic gains and losses are a result of genomic instability in many types of cancers. BRCA1- and BRCA2-mutated breast cancers are associated with increased amounts of chromosomal aberrations, presumably due their functions in genome repair. Some of these genomic aberrations may harbor genes whose absence or overexpression may give rise to cellular growth advantage. So far, it has not been easy to identify the driver genes underlying gains and losses. A powerful approach to identify these driver genes could be a cross-species comparison of array comparative genomic hybridization (aCGH) data from cognate mouse and human tumors. Orthologous regions of mouse and human tumors that are commonly gained or lost might represent essential genomic regions selected for gain or loss during tumor development. Methods: To identify genomic regions that are associated with BRCA1- and BRCA2-mutated breast cancers we compared aCGH data from 130 mouse Brca1?/?;p53?/?, Brca2?/?;p53?/? and p53?/? mammary tumor groups with 103 human BRCA1-mutated, BRCA2-mutated and non-hereditary breast cancers. Results: Our genome-wide cross-species analysis yielded a complete collection of loci and genes that are commonly gained or lost in mouse and human breast cancer. Principal common CNAs were the well known MYCassociated gain and RB1/INTS6-associated loss that occurred in all mouse and human tumor groups, and the AURKA-associated gain occurred in BRCA2-related tumors from both species. However, there were also important differences between tumor profiles of both species, such as the prominent gain on chromosome 10 in mouse Brca2?/?;p53?/? tumors and the PIK3CA associated 3q gain in human BRCA1-mutated tumors, which occurred in tumors from one species but not in tumors from the other species. This disparity in recurrent aberrations in mouse and human tumors might be due to differences in tumor cell type or genomic organization between both species. Conclusions: The selection of the oncogenome during mouse and human breast tumor development is markedly different, apart from the MYC gain and RB1-associated loss. These differences should be kept in mind when using mouse models for preclinical studies.MediamaticsElectrical Engineering, Mathematics and Computer Scienc
adku1173/acoupipe: v23.11.
<h2>What's Changed</h2>
<p>The new AcouPipe 23.11. Release includes several fundamental changes and new features.</p>
<h4>New datasets submodule</h4>
<p>A new submodule named <a href="https://adku1173.github.io/acoupipe/autoapi/acoupipe/datasets/index.html">acoupipe.datasets</a> is now included, which contains two default dataset classes that can be instantiated to generate microphone array data for machine learning. They can be used to generate training data on the fly without writing data to file. <a href="https://adku1173.github.io/acoupipe/contents/jupyter/generate.html">See the docs for an example</a></p>
<h4>Improved parallel computation speed</h4>
<p>The <code>acoupipe.DistributedPipeline</code> now makes use of the <code>Actor</code> principle available in <a href="https://docs.ray.io/en/latest/ray-core/actors.html">Ray</a>. In each parallel task, random sampling and feature extraction is now performed by a dedicated <code>acoupipe.pipeline.SamplerActor</code>. This architectural change drastically improves performance.</p>
<h4>Multiple Docker images</h4>
<p>Different Docker images are now available on <a href="https://hub.docker.com/repository/docker/adku1173/acoupipe/general">DockerHub</a>.</p>
<h4>Minor changes</h4>
<ul>
<li>improvement of code documentation</li>
<li>update package structure</li>
<li>extended tests</li>
</ul>
<h4>Important Pull Requests</h4>
<ul>
<li>Docker CI by @adku1173 in https://github.com/adku1173/acoupipe/pull/24</li>
<li>Dev by @adku1173 in https://github.com/adku1173/acoupipe/pull/31</li>
<li>Pre release work by @adku1173 in https://github.com/adku1173/acoupipe/pull/32</li>
</ul>
<p><strong>Full Changelog</strong>: https://github.com/adku1173/acoupipe/compare/v21.08...v23.11</p>
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Prototype Small-Animal PET-CT Imaging System for Image-Guided Radiation Therapy
Molecular imaging is becoming essential for precision targeted radiation therapy, yet progress is hindered from a lack of integrated imaging and treatment systems. We report the development of a prototype positron emission tomography (PET) scanner integrated into a commercial cone beam computed tomography (CBCT) based small animal irradiation system for molecular-image-guided, targeted external beam radiation therapy. The PET component consists of two rotating Hamamatsu time-of-flight PET modules positioned with a bore diameter of 101.6 mm and a radial field-of-view of 53.1 mm. The measured energy resolution after linearity correction at 511 KeV was 12.9% and the timing resolution was 283.6 ps. The measured spatial resolutions at the field-of-view center and 5 mm off the radial center were 2.6 mm × 2.6 mm × 1.6 mm and 2.6 mm × 2.6 mm × 2.7 mm respectively. 18F-Fluorodeoxyglucose-based PET imaging of a NEMA NU 4-2008 phantom resolved cylindrical volumes with diameters as small as 3 mm. To validate the system in-vivo, we performed 64Cu-DOTA-M5A PET and computed tomography (CT) imaging of carcinoembryonic antigen (CEA)-positive colorectal cancer in athymic nude mice and compared the results with a commercially available Siemens Inveon PET/CT system. The prototype PET system performed comparably to the Siemens system for identifying the location, size, and shape of tumors. Regions of heterogeneous 64Cu-DOTA-M5A uptake were observed. Using 64Cu-DOTA-M5A PET and CT images, a Monte Carlo-based radiation treatment plan was created to escalate the dose to the 64Cu-DOTA-M5A-based, highly active, biological target volume while largely sparing the normal tissue. Results demonstrate the feasibility of molecular-image-guided treatment plans using the prototype theranostic system