499 research outputs found
GAN-based Virtual Re-Staining: A Promising Solution for Whole Slide Image Analysis
Histopathological cancer diagnosis is based on visual examination of stained
tissue slides. Hematoxylin and eosin (H\&E) is a standard stain routinely
employed worldwide. It is easy to acquire and cost effective, but cells and
tissue components show low-contrast with varying tones of dark blue and pink,
which makes difficult visual assessments, digital image analysis, and
quantifications. These limitations can be overcome by IHC staining of target
proteins of the tissue slide. IHC provides a selective, high-contrast imaging
of cells and tissue components, but their use is largely limited by a
significantly more complex laboratory processing and high cost. We proposed a
conditional CycleGAN (cCGAN) network to transform the H\&E stained images into
IHC stained images, facilitating virtual IHC staining on the same slide. This
data-driven method requires only a limited amount of labelled data but will
generate pixel level segmentation results. The proposed cCGAN model improves
the original network \cite{zhu_unpaired_2017} by adding category conditions and
introducing two structural loss functions, which realize a multi-subdomain
translation and improve the translation accuracy as well. % need to give
reasons here. Experiments demonstrate that the proposed model outperforms the
original method in unpaired image translation with multi-subdomains. We also
explore the potential of unpaired images to image translation method applied on
other histology images related tasks with different staining techniques
MATLABER: Material-Aware Text-to-3D via LAtent BRDF auto-EncodeR
Based on powerful text-to-image diffusion models, text-to-3D generation has
made significant progress in generating compelling geometry and appearance.
However, existing methods still struggle to recover high-fidelity object
materials, either only considering Lambertian reflectance, or failing to
disentangle BRDF materials from the environment lights. In this work, we
propose Material-Aware Text-to-3D via LAtent BRDF auto-EncodeR
(\textbf{MATLABER}) that leverages a novel latent BRDF auto-encoder for
material generation. We train this auto-encoder with large-scale real-world
BRDF collections and ensure the smoothness of its latent space, which
implicitly acts as a natural distribution of materials. During appearance
modeling in text-to-3D generation, the latent BRDF embeddings, rather than BRDF
parameters, are predicted via a material network. Through exhaustive
experiments, our approach demonstrates the superiority over existing ones in
generating realistic and coherent object materials. Moreover, high-quality
materials naturally enable multiple downstream tasks such as relighting and
material editing. Code and model will be publicly available at
\url{https://sheldontsui.github.io/projects/Matlaber}
Ultrasensitive Analysis of Binding Affinity of HIV Receptor and Neutralizing Antibodies Using Solution-Phase Electrochemiluminescence Assay
Binding of a few ligand molecules with its receptors on cell surface can initiate cellular signaling transduction pathways, and trigger viral infection of host cells. HIV-1 infects host T-cells by binding its viral envelope protein (gp120) with its receptor (a glycoprotein, CD4) on T cells. Primary strategies to prevent and treat HIV infection is to develop therapies (e.g., neutralizing antibodies) that can block specific binding of CD4 with gp120. The infection often leads to the lower counts of CD4 cells, which makes it an effective biomarker to monitor the AIDS progression and treatment. Despite research over decades, quantitative assays for effective measurements of binding affinities of protein-protein (ligand-receptor, antigen-antibody) interactions remains highly sought. Solid-phase electrochemiluminescence (ECL) immunoassay has been commonly used to capture analytes from the solution for analysis, which involves immobilization of antibody on solid surfaces (micron-sized beads), but it cannot quantitatively measure binding affinities of molecular interactions. In this study, we have developed solution phase ECL assay with a wide dynamic range (0–2 nM) and high sensitivity and specificity for quantitative analysis of CD4 at femtomolar level and their binding affinity with gp120 and monoclonal antibodies (MABs). We found that binding affinities of CD4 with gp120 and MAB (Q4120) are 9.5×108 and 1.2×109 M−1, respectively. The results also show that MAB (Q4120) of CD4 can completely block the binding of gp120 with CD4, while MAB (17b) of gp120 can only partially block their interaction. This study demonstrates that the solution-phase ECL assay can be used for ultrasensitive and quantitative analysis of binding affinities of protein-protein interactions in solution for better understating of protein functions and identification of effective therapies to block their interactions
US-net for robust and efficient nuclei instance segmentation
We present a novel neural network architecture, US-Net, for robust nuclei
instance segmentation in histopathology images. The proposed framework
integrates the nuclei detection and segmentation networks by sharing their
outputs through the same foundation network, and thus enhancing the performance
of both. The detection network takes into account the high-level semantic cues
with contextual information, while the segmentation network focuses more on the
low-level details like the edges. Extensive experiments reveal that our
proposed framework can strengthen the performance of both branch networks in an
integrated architecture and outperforms most of the state-of-the-art nuclei
detection and segmentation networks.Comment: To appear in ISBI 201
Performance of agglomeration bonuses in conservation auctions: Lessons from a framed field experiment
The incorporation of an agglomeration bonus payment to encourage spatial coordination in auction mechanisms to allocate Payments for Ecosystem Services (PES) contracts has been explored as a promising innovation that could enhance the effectiveness of PES schemes. Empirical evidence on the performance of this particular design feature is scant, and almost exclusively derived from laboratory experiments using student subjects. This study reports results from a framed field experimental auction allocating PES contracts with and without agglomeration bonus payments using actual forest land owners in rural China as subjects. We find tentative evidence that, in a PES auction that provides agglomeration bonuses, subjects tend to bid less in anticipation of receiving bonus payments when their neighbours are also successful in the auction. In addition, we have mixed findings as to whether the agglomeration bonus is able to induce a bidding pattern in favour of contiguous conservation. The two sets of results convey some encouraging signals of the theoretically postulated cost-effectiveness and conservation efficacy of the agglomeration bonus. Further research from the actual field is warranted in light of the policy significance of this innovative incentive mechanism.British Academy
The Environment for Development Initiative
Chemical constituents and hypoglycemic mechanisms of Dendrobium nobile in treatment of type 2 diabetic rats by UPLC-ESI-Q-Orbitrap, network pharmacology and in vivo experimental verification
Abstract: This study aimed to systematically explore the chemical constituents of D. nobile and its hypoglycemic effect by UPLC-ESI-Q-Orbitrap, network pharmacology and in vivo experiment. The chemical constituents of D. nobile were qualitatively analyzed, and the hypoglycemic compounds were quickly identified. Network pharmacological analysis and molecular docking technique were applied to assist in the elucidation of the hypoglycemic mechanisms of D. nobile. A type 2 diabetic mellitus (T2DM) rat model was established using the HFD and STZ method for in vivo experimental verification, and these T2DM rats were treated with D. nobile extract and D. nobile polysaccharide for two months by gavage. The results showed that a total of 39 chemical constituents of D. nobile, including
alkaloids, bibenzyls, phenanthrenes and other types of compounds, were identified. D. nobile extract and D. nobile polysaccharide could significantly ameliorate the body weight, hyperglycemia, insulin resistance, dyslipidemia and morphological impairment of the liver and pancreas in the T2DM rats. α-Linolenic acid, dihydroconiferyl dihydro-p-coumarate, naringenin, trans-N-feruloyltyramine, gigantol, moscatilin, 4-O-methylpinosylvic acid, venlafaxine, nordendrobin and tristin were regarded as the key hypoglycemic compounds of D. nobile, along with the hypoglycemic effect on the PI3K-AKT signaling pathway, the insulin signaling pathway, the FOXO signaling pathway, the improvement of
insulin resistance and the AGE-RAGE signaling pathway. The Western blotting experiment results confirmed that D. nobile activated the PI3K/AKT pathway and insulin signaling pathway, promoted glycogen synthesis via regulating the expression of glycogen synthase kinase 3 beta (GSK-3) and glucose transporter 4 (GLUT4), and inhibited liver gluconeogenesis by regulating the expression
of phosphoenolpyruvate carboxykinase (PEPCK) and glucose 6 phosphatase (G6pase) in the liver. The results suggested that the hypoglycemic mechanism of D. nobile might be associated with liver glycogen synthesis and gluconeogenesis, contributing to improving insulin resistance and abnormal glucose metabolism in the T2DM rats
Reconfigurable Intelligent Surface Based Orbital Angular Momentum: Architecture, Opportunities, and Challenges
Orbital angular momentum (OAM) has gained a lot of attention due to its potential in enhancing the spectral efficiency for wireless communications. Using different OAM modes, multiple independent data streams are simultaneously transmitted by using spatial distribution of helical phase, which enables OAM as a new form of multiple access technique for wireless communications. Controlling the phases of incoming electromagnetic waves, the reconfigurable intelligent surface (RIS) is suitable for implementing OAM. In this article, an RIS-based OAM framework is introduced. The basic concepts and features of RIS and OAM are presented. Then classifications and comparisons of different RIS-based OAM schemes are summarized. Simulation results verify that RIS-based OAM transmission can achieve nearly 100 percent higher spectral efficiency of wireless communication systems compared to the conventional RIS scheme
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