155 research outputs found

    Multi-Scale Modeling and Rheological Approaches for Understanding the Structure-Property Relationships of Surfactant Solutions.

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    In this work, we applied multi-scale modeling and rheological measurements to understand the structure-property relationships of surfactant solutions. We used molecular dynamics (MD) and dissipative particle dynamics (DPD) simulations to address behavior extending from the molecular level to the micellar mesoscale, the Cates model to bridge the micellar mesoscale to macroscale rheological behavior, and rheometry to measure rheological behavior and compare it to predictions of the Cates model. Starting with a simple surfactant, sodium dodecyl sulfate, we compared force field effects on micellar properties at various aggregation numbers by MD simulations. We found the parameters that control the shape of large micelles were the Lennard-Jones parameters of Na+ and ionic oxygen atoms, as well as the water model, which controls hydration of Na+ in the presence of surfactants. These parameters control the degree of binding of Na+ to ionic oxygens and head group packing, and resulted in different micellar shapes. We also studied structure-property relationships of a commercial surfactant mixture, polyoxyethylene (PEO) sorbitan oleates, which contains multiple species and were represented as five “typical” structures varying the lengths of EO head groups and the number of tails using MD simulations. We found structures with more than one tail, and with shorter EO head group that attaches the tail to the sorbitan ring, pack more efficiently within micelles and at interfaces. This efficient packing leads to lower interfacial tensions at air–water and oil–water interfaces at the same surfactant interfacial density. Finally to assess the behavior of complex body washes containing cylindrical micelles, we studied the effects of salts (NaCl) and perfume raw materials (PRMs) by combining results from rheology, the micellar Cates model, and DPD modeling. We determined the relationship between viscosity and average micelle length, and elasticity and micellar characteristic time. Salts modify viscoelasticities of body washes by condensing Na+ near micellar surface, changing surfactant head groups packing, and maintaining the cross-section radius constant. PRMs modify viscoelasticities of body washes by partitioning into the micelles according to their octanol/water partition coefficients and chemical structures, adjusting surfactant packing at head and/or tail regions, and possibly changing the cross-section radius.PHDChemical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/111497/1/xuemtang_1.pd

    Curriculum Knowledge Switching for Pancreas Segmentation

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    Pancreas segmentation is challenging due to the small proportion and highly changeable anatomical structure. It motivates us to propose a novel segmentation framework, namely Curriculum Knowledge Switching (CKS) framework, which decomposes detecting pancreas into three phases with different difficulty extent: straightforward, difficult, and challenging. The framework switches from straightforward to challenging phases and thereby gradually learns to detect pancreas. In addition, we adopt the momentum update parameter updating mechanism during switching, ensuring the loss converges gradually when the input dataset changes. Experimental results show that different neural network backbones with the CKS framework achieved state-of-the-art performance on the NIH dataset as measured by the DSC metric.Comment: ICIP 202

    A Perfectly Binding Commitment Scheme Against Quantum Attacks

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    It\u27s known that perfectly binding quantum computationally hiding commitment schemes can be constructed from any quantum one-way permutation. Since no quantum one-way permutations are known, it has been unknown by far whether we can get such a concrete commitment scheme. In this paper, we give a positive answer. Specifically, we present such a lattice-based commitment scheme, which is built from the results gained by Gentry et al

    Inhibition of miR-665 alleviates lipopolysaccharide-induced inflammation via up-regulation of SOCS7 in chondrogenic ATDC5 cells

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    Purpose: To examine the effect and mechanism of action of miR-665 in osteoarthritis.Methods: An in vitro inflammatory injury model of osteoarthritis was established using chondrogenic ATDC5 cells with lipopolysaccharide (LPS) treatment. The expression levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assays (ELISAs) and by quantitative real-time polymerase chain reaction (qRT-PCR). A binding target for miR-665 was predicted using TargetScan and then evaluated using a dual-luciferase reporter assay.Results: Treatment with LPS significantly up-regulated the inflammatory cytokine expressions of interleukin-1β (IL-1β), IL-6, and tumor necrosis factor-alpha (TNF-α), in ATDC5 cells (p < 0.01), and the expression of miRNA-665 was significantly increased in LPS-treated ATDC5 cells (p < 0.01).Knockdown of miR-665 down-regulated the expression levels of these inflammatory cytokines. Suppressor of cytokine signaling 7 (SOCS7) was identified as a target of miR-665. Data from qRT-PCR and western-blot analyses indicated that SOCS7 expression was promoted by miR-665  inhibition and inhibited by miR-665 over-expression. LPS treatment significantly decreased the expression of SOCS7 protein in ATDC5 cells (p < 0.01), and over-expression of SOCS7 attenuated the LPS-stimulated inflammatory injury. In addition, over-expression of miR-655 enhanced the inflammatory injury and reversed the protective effect of SOCS7 against LPS-stimulated inflammation.Conclusion: Inhibition of miR-665 alleviated LPS-stimulated inflammatory injury in ATDC5 cells via the up-regulation of SOCS7, suggesting a potential therapeutic target for osteoarthritis. Keywords: MiR-665, Lipopolysaccharide, Inflammation, SOCS7, Chondrogenic, ATDC

    Knockdown of Brm and Baf170, Components of Chromatin Remodeling Complex, Facilitates Reprogramming of Somatic Cells

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    © Copyright 2015, Mary Ann Liebert, Inc. 2015. The SWI/SNF (SWItch/Sucrose NonFermentable or BAF, Brg/Brahma-associated factors) complexes are epigenetic modifiers of chromatin structure and undergo progressive changes in subunit composition during cellular differentiation. For example, in embryonic stem cells, esBAF contains Brg1 and Baf155, while their homologs, Brm and Baf170, are present in BAF of somatic cells. In this study, we sought to determine whether Brm and Baf170 play any roles in induced pluripotent stem cell (iPSC) reprogramming by using shRNA-mediated knockdown studies in the mouse model. We found that knocking down Brm during early, mid, and late stages (days 3, 6, and 9 after initial iPSC induction) and knocking down Baf170 during late-stage (day 9) reprogramming improve the numbers of iPSC colonies formed. We further showed that inhibition of these somatic BAF components also promotes complete reprogramming of partially reprogrammed somatic cells (pre-iPSCs). Finally, we found that the expression of Brm and Baf170 during reprogramming was regulated by Jak/Stat3 activity. Taken together, these data suggest that inhibiting somatic BAF improves complete reprogramming by facilitating the activation of the pluripotency circuitry

    Practical Frameworks For hh-Out-Of-nn Oblivious Transfer With Security Against Covert and Malicious Adversaries

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    We present two practical frameworks for hh-out-of-nn oblivious transfer (OThnOT^{n}_{h}). The first one is secure against covert adversaries who are not always willing to cheat at any price. The security is proven under the ideal/real simulation paradigm (call such security fully simulatable security). The second one is secure against malicious adversaries who are always willing to cheat. It provides fully simulatable security and privacy respectively for the sender and the receiver (call such security one-sided simulatable security). The two frameworks can be implemented from the decisional Diffie-Hellman (DDH) assumption, the decisional NN-th residuosity assumption, the decisional quadratic residuosity assumption and so on. The DDH-based instantiation of our first framework costs the minimum communication rounds and the minimum computational overhead, compared with existing practical protocols for oblivious transfer with fully simulatable security against covert adversaries or malicious adversaries. Though our second framework is not efficient, compared with existing practical protocols with one-sided simulatable security against malicious adversaries. However, it first provides a way to deal with general OThnOT^{n}_{h} on this security level. What is more, its DDH-based instantiation is more efficient than the existing practical protocols for oblivious transfer with fully simulatable security against malicious adversaries

    Learning a Condensed Frame for Memory-Efficient Video Class-Incremental Learning

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    Recent incremental learning for action recognition usually stores representative videos to mitigate catastrophic forgetting. However, only a few bulky videos can be stored due to the limited memory. To address this problem, we propose FrameMaker, a memory-efficient video class-incremental learning approach that learns to produce a condensed frame for each selected video. Specifically, FrameMaker is mainly composed of two crucial components: Frame Condensing and Instance-Specific Prompt. The former is to reduce the memory cost by preserving only one condensed frame instead of the whole video, while the latter aims to compensate the lost spatio-temporal details in the Frame Condensing stage. By this means, FrameMaker enables a remarkable reduction in memory but keep enough information that can be applied to following incremental tasks. Experimental results on multiple challenging benchmarks, i.e., HMDB51, UCF101 and Something-Something V2, demonstrate that FrameMaker can achieve better performance to recent advanced methods while consuming only 20% memory. Additionally, under the same memory consumption conditions, FrameMaker significantly outperforms existing state-of-the-arts by a convincing margin.Comment: NeurIPS 202

    Effect of Miao medicine, Jinwujiangu decoction, on IL- 17/IL-23 inflammatory axis of fibroblast-like synoviocytes in rheumatoid arthritis

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    Purpose: To explore the influence of the Miao medicine, Jinwujiangu decoction, on the interleukin (IL)- 17/IL-23 inflammatory axis of fibroblast-like synoviocytes (FLS) in rheumatoid arthritis (RA).Methods: Synovial tissue samples were randomly divided into a blank control group, high-dose (0.06mg/mL), medium-dose (0.6mg/mL), and low-dose (6.0mg/mL) groups of Jinwujiangu decoction, a leflunomide group, and a tripterygium glycosides group. Proliferation of RA synovial cells was detected by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Enzyme-linked immunosorbent assay (ELISA) was used to determine the secretion of IL-6, transforming growth factor beta (TGF-β), and IL-17. Real-time polymerase chain reaction was used to evaluate the expression of IL-23R, IL-17R, RAR-related orphan receptor alpha (RORα), RORγt, and signal transducer and activator of transcription (STAT3) mRNA. The protein activities of IL-17R, STAT3 and pSTAT3 were assessed by Western blot assay.Results: Jinwujiangu decoction inhibited the proliferation of RA synovial cells. Treatment with different drug concentrations resulted in downregulation of IL-6, TGF-β, and IL-17 secretion. The expression levels of IL-23R, IL-17R, RORα, RORγt, and STAT3 mRNA in RA-FLS were significantly reduced after intervention with different drugs. Protein expression levels of STAT3, pSTAT3, and IL-17 in the different drug treatment groups were significantly decreased.Conclusion: Jinwujiangu decoction inhibits the secretion of IL-6 and TGF-β in RA-FLS, and intervenes to regulate gene expression of IL-23/IL-17 inflammation axis and suppress immune inflammation. The results of this study provide new evidence for the study of anti-inflammatory mechanism of TCM compound prescription.Keywords: Jinwujiangu decoction, IL-17/IL-23, Fibroblast-like synoviocytes, Rheumatoid arthritis, Ethnomedicin

    Screening of specific diagnostic peptides of swine hepatitis E virus

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    © 2009 Zhao et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
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