459 research outputs found
Macroporous Materials from Sintering Capillary Aggregate Networks
Capillary aggregate is one of the morphologies that appear in ternary mixtures of particles
and two immiscible fluids. Capillary aggregates appear when two conditions are satisfied: the
particles are fully-wetted by one of the two liquid phases, and furthermore, the wetting fluid
has a volume fraction that is roughly equal to the particle volume fraction. Under these
conditions, the wetting fluid creates highly compact particle aggregates called capillary
aggregates. Recent research suggests that capillary aggregates can stick to one another to
create a network in which capillary aggregates act as building blocks.
The aim of this study is to develop a macro-porous material from sintering capillary
aggregate networks. In this study, morphologies of ternary mixtures in which the continuous
phase is ethylene glycol, the wetting phase is light mineral oil and the solid phase is
hydrophobic particles of low melting temperature polymer were studied. Capillary aggregate
networks were prepared by suitable mixing methods, and then the mixtures were sintered to
obtain macro-porous materials. Such macro-porous materials may be used as scaffolds for
cells growth.iv
This thesis reported the implementation of capillary aggregate networks and the procedures
of sintering and washing process. The effects of composition of ternary mixtures on porosity,
pore sizes and number of aggregates were studied.
This study demonstrates that by sintering capillary aggregate networks, we can obtain high
porosity materials with low particle loading, and obtain large pore sizes without using
different size particles. Moreover, result shows that cells can grow well in the macro-porous
materials
Enhanced cancer therapy with cold-controlled drug release and photothermal warming enabled by one nanoplatform
Stimuli-responsive nanoparticles hold great promise for drug delivery to improve the safety and efficacy of cancer therapy. One of the most investigated stimuli-responsive strategies is to induce drug release by heating with laser, ultrasound, or electromagnetic field. More recently, cryosurgery (also called cryotherapy and cryoablation), destruction of diseased tissues by first cooling/freezing and then warming back, has been used to treat various diseases including cancer in the clinic. Here we developed a cold-responsive nanoparticle for controlled drug release as a result of the irreversible disassembly of the nanoparticle when cooled to below ∼10 °C. Furthermore, this nanoparticle can be used to generate localized heating under near infrared (NIR) laser irradiation, which can facilitate the warming process after cooling/freezing during cryosurgery. Indeed, the combination of this cold-responsive nanoparticle with ice cooling and NIR laser irradiation can greatly augment cancer destruction both in vitro and in vivo with no evident systemic toxicity
MeshNet: Mesh Neural Network for 3D Shape Representation
Mesh is an important and powerful type of data for 3D shapes and widely
studied in the field of computer vision and computer graphics. Regarding the
task of 3D shape representation, there have been extensive research efforts
concentrating on how to represent 3D shapes well using volumetric grid,
multi-view and point cloud. However, there is little effort on using mesh data
in recent years, due to the complexity and irregularity of mesh data. In this
paper, we propose a mesh neural network, named MeshNet, to learn 3D shape
representation from mesh data. In this method, face-unit and feature splitting
are introduced, and a general architecture with available and effective blocks
are proposed. In this way, MeshNet is able to solve the complexity and
irregularity problem of mesh and conduct 3D shape representation well. We have
applied the proposed MeshNet method in the applications of 3D shape
classification and retrieval. Experimental results and comparisons with the
state-of-the-art methods demonstrate that the proposed MeshNet can achieve
satisfying 3D shape classification and retrieval performance, which indicates
the effectiveness of the proposed method on 3D shape representation
Rosavin exerts an antitumor role and inactivates the MAPK/ERK pathway in small-cell lung carcinoma in vitro
This study attempts to explore the function and mechanism of action of rosavin in small-cell lung cancer (SCLC) in vitro. The viability and clone formation of SCLC cells were assessed using cell counting kit-8 and colony formation assays, respectively. Apoptosis and cell cycle were detected using flow cytometry and cell cycle analysis, respectively. Wound healing and transwell assays were performed to evaluate the migration and invasion of SCLC cells. Besides, protein levels of p-ERK, ERK, p-MEK and MEK were determined using western blot analysis. Rosavin repressed the viability and clone formation of SCLC cells, and promoted apoptosis and G0/G1 arrest of SCLC cells. At the same time, rosavin suppressed migration and invasion of SCLC cells. Moreover, protein levels of p-ERK/ERK and p-MEK/MEK were decreased after rosavin addition in SCLC cells. Rosavin impaired malignant behaviors of SCLC cells, which may be associated with inhibition of the MAPK/ERK pathway in vitro
A local resampling trick for focused molecular dynamics
We describe a method that focuses sampling effort on a user-defined selection
of a large system, which can lead to substantial decreases in computational
effort by speeding up the calculation of nonbonded interactions. A naive
approach can lead to incorrect sampling if the selection depends on the
configuration in a way that is not accounted for. We avoid this pitfall by
introducing appropriate auxiliary variables. This results in an implementation
that is closely related to configurational freezing and elastic barrier
dynamical freezing. We implement the method and validate that it can be used to
supplement conventional molecular dynamics in free energy calculations
(absolute hydration and relative binding)
More than Classification: A Unified Framework for Event Temporal Relation Extraction
Event temporal relation extraction~(ETRE) is usually formulated as a
multi-label classification task, where each type of relation is simply treated
as a one-hot label. This formulation ignores the meaning of relations and wipes
out their intrinsic dependency. After examining the relation definitions in
various ETRE tasks, we observe that all relations can be interpreted using the
start and end time points of events. For example, relation \textit{Includes}
could be interpreted as event 1 starting no later than event 2 and ending no
earlier than event 2. In this paper, we propose a unified event temporal
relation extraction framework, which transforms temporal relations into logical
expressions of time points and completes the ETRE by predicting the relations
between certain time point pairs. Experiments on TB-Dense and MATRES show
significant improvements over a strong baseline and outperform the
state-of-the-art model by 0.3\% on both datasets. By representing all relations
in a unified framework, we can leverage the relations with sufficient data to
assist the learning of other relations, thus achieving stable improvement in
low-data scenarios. When the relation definitions are changed, our method can
quickly adapt to the new ones by simply modifying the logic expressions that
map time points to new event relations. The code is released at
\url{https://github.com/AndrewZhe/A-Unified-Framework-for-ETRE}
UKnow: A Unified Knowledge Protocol for Common-Sense Reasoning and Vision-Language Pre-training
This work presents a unified knowledge protocol, called UKnow, which
facilitates knowledge-based studies from the perspective of data. Particularly
focusing on visual and linguistic modalities, we categorize data knowledge into
five unit types, namely, in-image, in-text, cross-image, cross-text, and
image-text. Following this protocol, we collect, from public international
news, a large-scale multimodal knowledge graph dataset that consists of
1,388,568 nodes (with 571,791 vision-related ones) and 3,673,817 triplets. The
dataset is also annotated with rich event tags, including 96 coarse labels and
9,185 fine labels, expanding its potential usage. To further verify that UKnow
can serve as a standard protocol, we set up an efficient pipeline to help
reorganize existing datasets under UKnow format. Finally, we benchmark the
performance of some widely-used baselines on the tasks of common-sense
reasoning and vision-language pre-training. Results on both our new dataset and
the reformatted public datasets demonstrate the effectiveness of UKnow in
knowledge organization and method evaluation. Code, dataset, conversion tool,
and baseline models will be made public
Fiber absorption measurement errors resulting from re-emission of radiation
We show that errors in the absorption measured in rare-earth-doped fibers can exceed 50% and severely distort the spectral shape. This is a result of re-emission in fibers with overlapping absorption and emission spectra
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