540 research outputs found
Predict the distribution of nanoparticles in molten metal
In the present study the results of mathematical modeling of the process of introducing particles into an aluminum melt using the mixing device. A pattern of the distribution of these particles in the melt is obtained
MACC1 driven alterations in cellular biomechanics facilitate cell motility in glioblastoma
BACKGROUND: Metastasis-associated in colon cancer 1 (MACC1) is an established marker for metastasis and tumor cell migration in a multitude of tumor entities, including glioblastoma (GBM). Nevertheless, the mechanism underlying the increased migratory capacity in GBM is not comprehensively explored. METHODS: We performed live cell and atomic force microscopy measurements to assess cell migration and mechanical properties of MACC1 overexpressing GBM cells. We quantified MACC1 dependent dynamics of 3D aggregate formation. For mechanistic studies we measured the expression of key adhesion molecules using qRT-PCR, and MACC1 dependent changes in short term adhesion to fibronectin and laminin. We then determined changes in sub-cellular distribution of integrins and actin in dependence of MACC1, but also in microtubule and intermediate filament organization. RESULTS: MACC1 increased the migratory speed and elastic modulus of GBM cells, but decreased cell-cell adhesion and inhibited the formation of 3D aggregates. These effects were not associated with altered mRNA expression of several key adhesion molecules or altered short-term affinity to laminin and fibronectin. MACC1 did neither change the organization of the microtubule nor intermediate filament cytoskeleton, but resulted in increased amounts of protrusive actin on laminin. CONCLUSION: MACC1 overexpression increases elastic modulus and migration and reduces adhesion of GBM cells thereby impeding 3D aggregate formation. The underlying molecular mechanism is independent on the organization of microtubules, intermediate filaments and several key adhesion molecules, but depends on adhesion to laminin. Thus, targeting re-organization of the cytoskeleton and cell motility via MACC1 may offer a treatment option to impede GBM spreading
Conceptual Design for Electromagnetic Guided Rotary Table in Machine Tools
Difficult-to-machine materials are still challenging the production industry. Examples are highly complex components of aircraft engines. Alongside innovative processes, also improved machine tool components are helping to comply with the demands of this task. This paper presents a design approach of a rotary table with an active magnetic bearing. Opportunities in machining through employing magnetic guides are presented and discussed in the beginning. In the following, a workflow for the magnetic bearing design in swivel rotary tables is proposed. The mentioned steps are executed based on a presently under design rotary table
The poverty of journal publishing
The article opens with a critical analysis of the dominant business model of for-profit, academic publishing, arguing that the extraordinarily high profits of the big publishers are dependent upon a double appropriation that exploits both academic labour and universities’ financial resources. Against this model, we outline four possible responses: the further development of open access repositories, a fair trade model of publishing regulation, a renaissance of the university presses, and, finally, a move away from private, for-profit publishing companies toward autonomous journal publishing by editorial boards and academic associations. </jats:p
MACC1-induced collective migration is promoted by proliferation rather than single cell biomechanics
Metastasis-associated in colon cancer 1 (MACC1) is a marker for metastasis, tumor cell migration, and increased proliferation in colorectal cancer (CRC). Tumors with high MACC1 expression show a worse prognosis and higher invasion into neighboring structures. Yet, many facets of the pro-migratory effects are not fully understood. Atomic force microscopy and single cell live imaging were used to quantify biomechanical and migratory properties in low- and high-MACC1-expressing CRC cells. Furthermore, collective migration and expansion of small, cohesive cell colonies were analyzed using live cell imaging and particle image velocimetry. Lastly, the impact of proliferation on collective migration was determined by inhibition of proliferation using mitomycin. MACC1 did not affect elasticity, cortex tension, and single cell migration of CRC cells but promoted collective migration and colony expansion in vitro. Measurements of the local velocities in the dense cell layers revealed proliferation events as regions of high local speeds. Inhibition of proliferation via mitomycin abrogated the MACC1-associated effects on the collective migration speeds. A simple simulation revealed that the expansion of cell clusters without proliferation appeared to be determined mostly by single cell properties. MACC1 overexpression does not influence single cell biomechanics and migration but only collective migration in a proliferation-dependent manner. Thus, targeting proliferation in high-MACC1-expressing tumors may offer additional effects on cell migration
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Can children measure their own vision? A comparison of three new contrast sensitivity tests
Purpose
To investigate the feasibility of children measuring their own contrast sensitivity using a range of tablet- and paper-based tests.
Methods
Forty children aged 5–15 years with amblyopia (N = 10), bilateral vision impairment (N = 10) or good vision (N = 20) measured their own vision on a screen-based optotype test (Manifold), a gamified vision test (PopCSF) and a paper-based test (Spotchecks) in a laboratory with minimal supervision. Completion rate, test–retest repeatability, test duration and participants' preferences were recorded for each test.
Results
Most participants (36/40) were able to perform all three tests. All tests were correlated with clinically measured visual acuity and contrast sensitivity (p < 0.001). The 95% coefficient of repeatability was 0.30 dB for Manifold, 0.29 dB for PopCSF and 0.13 dB for Spotchecks. All tests differentiated between children with reduced contrast sensitivity and control participants. PopCSF and Spotchecks were also able to differentiate between children with amblyopia and those with good vision. Median test time was 152, 130 and 202 s for Manifold, PopCSF and Spotchecks, respectively. Twenty-two participants preferred the PopCSF test, 10 preferred Spotchecks and 6 preferred Manifold. Thirty-nine out of the 40 children (98%) said they would measure their own vision at home using at least one of these tests every month.
Conclusions
Children and young people can test their own contrast sensitivity with repeatable results. Of these three tests, the most repeatable was Spotchecks, the quickest was PopCSF and participants' favourite was PopCSF. Nearly all of the participants said they would be willing to use at least one of the three tests at home
МОДЕЛИРОВАНИЕ ПРОЦЕССОВ ДОСТАВКИ ВСПОМОГАТЕЛЬНыХ ГРУЗОПОТОКОВ ВНУТРИШАХТНОГО ТРАНСПОРТА С УЧЕТОМ ХАРАКТЕРИСТИКИ ТРАССы
Розглянуто специфічні задачі внутрішахтного транспорту. Запропоновано використовувати метод
Флойду-Уоршелла для моделювання допоміжних вантажопотоків з урахуванням характеристики мар-
шруту. Наведені результати застосування цього методу для своєчасної доставки матеріальних потоків
вугільних шахт у підготовчі вибої.
Рассмотрены специфические задачи внутришахтного транспорта. Предложено использовать метод
Флойда – Уоршелла для моделирования вспомогательных грузопотоков с учетом характеристики трас-
сы. Приведены результаты применения используемого метода для оперативной доставки материаль-
ных потоков угольных шахт в подготовительные забои
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