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A metal-free catalytic method for the synthesis of 2-deoxy glycosides and disaccharides has been developed using stable 2-deoxy glucosyl and galactosyl acetate donors. They could react with a variety of acceptors in the presence o...
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A metal-free catalytic method for the synthesis of 2-deoxy glycosides and disaccharides has been developed using stable 2-deoxy glucosyl and galactosyl acetate donors. They could react with a variety of acceptors in the presence of catalytic amount of TMSOTf at 0癈 to form glycosides, glycoconjugates, and disaccharides with excellent ?selectivity (> 19:1) and yields (up to 99%) in a short time (0.5 h). With this expedient method, several new compounds against human K562 and SMMC7721 cell lines were obtained and tested with in vitro antitumor bioactivities.
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Icing is one of the most fascinating phenomena occurring ubiquitously in nature and multiple industrial applications. In spite of a century of research work on this topic, an in-depth physical description of icing process is still...
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Icing is one of the most fascinating phenomena occurring ubiquitously in nature and multiple industrial applications. In spite of a century of research work on this topic, an in-depth physical description of icing process is still missing due to the unorthodox behaviors of water during solidification. In recent years, many important features pertaining to some ultrafast and microscale phenomena in icing have been revealed using latest experimental techniques and newly developed numerical simulation methods. This work aims to present a comprehensive up-to-date review on the subject of icing. Fundamentals of icing nudeation dynamics are introduced, followed by discussion on propagations of freezing phase fronts. Different forms of icing, including freezing of droplets, desublimation/sublimation, and condensation frosting, are presented sequentially. Emphasis is placed on a few recently revealed phenomena, such as dendritic ice growth through desublimation, kinetic behaviors of droplets upon freezing, frost spreading by building icing bridges, etc. A summary of recent progress in the application of anti-/de- icing methods is also presented. The results of these studies not only improve our understanding of physical mechanisms on icing, but also benefit the understanding of solidification processes in other disciplines with different applications.
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Abstract The colonization and maturation of gut microbiota (GM) is a delicate and precise process, which continues to influence not only infancy and childhood but also adulthood health by affecting immunity. However, many perinata...
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Abstract The colonization and maturation of gut microbiota (GM) is a delicate and precise process, which continues to influence not only infancy and childhood but also adulthood health by affecting immunity. However, many perinatal factors, including gestational age, delivery mode, antibiotic administration, feeding mode, and environmental and maternal factors, can disturb this well-designed process, increasing the morbidity of various gut dysbiosis-related diseases, such as type-1-diabetes, allergies, necrotizing enterocolitis, and obesity. In this review, we discussed the early-life colonization and maturation of the GM, factors influencing this process, and diseases related to the disruption of this process. Moreover, we focused on discussing dietary interventions, including probiotics, oligosaccharides, nutritional supplementation, and exclusive enteral nutrition, in ameliorating early-life dysbiosis and diseases related to it. Furthermore, possible mechanisms, and shortcomings, as well as potential solutions to the drawbacks of dietary interventions, were also discussed.
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The whole-brain functional connectivity (FC) pattern obtained from resting-state functional magnetic resonance imaging data are commonly applied to study neuropsychiatric conditions such as autism spectrum disorder (ASD) by using ...
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The whole-brain functional connectivity (FC) pattern obtained from resting-state functional magnetic resonance imaging data are commonly applied to study neuropsychiatric conditions such as autism spectrum disorder (ASD) by using different machine learning models. Recent studies indicate that both hyper- and hypo- aberrant ASD-associated FCs were widely distributed throughout the entire brain rather than only in some specific brain regions. Deep neural networks (DNN) with multiple hidden layers have shown the ability to systematically extract lower-to-higher level information from high dimensional data across a series of neural hidden layers, significantly improving classification accuracy for such data. In this study, a DNN with a novel feature selection method (DNN-FS) is developed for the high dimensional whole-brain resting-state FC pattern classification of ASD patients vs. typical development (TD) controls. The feature selection method is able to help the DNN generate low dimensional high-quality representations of the whole-brain FC patterns by selecting features with high discriminating power from multiple trained sparse auto-encoders. For the comparison, a DNN without the feature selection method (DNN-woFS) is developed, and both of them are tested with different architectures (i.e., with different numbers of hidden layers/nodes). Results show that the best classification accuracy of 86.36% is generated by the DNN-FS approach with 3 hidden layers and 150 hidden nodes (3/150). Remarkably, DNN-FS outperforms DNN-woFS for all architectures studied. The most significant accuracy improvement was 9.09% with the 3/150 architecture. The method also outperforms other feature selection methods, e.g., two sample t-test and elastic net. In addition to improving the classification accuracy, a Fisher's score-based biomarker identification method based on the DNN is also developed, and used to identify 32 FCs related to ASD. These FCs come from or cross different pre-defined brain networks including the default-mode, cingulo-opercular, frontal-parietal, and cerebellum. Thirteen of them are statically significant between ASD and TD groups (two sample t-test p < 0.05) while 19 of them are not. The relationship between the statically significant FCs and the corresponding ASD behavior symptoms is discussed based on the literature and clinician's expert knowledge. Meanwhile, the potential reason of obtaining 19 FCs which are not statistically significant is also provided.
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The developing CNS is exposed to physiological hypoxia, under which hypoxia-inducible factor α (HIFα) is stabilized and plays a crucial role in regulating neural development. The cellular and molecular mechanisms of HIFα in dev...
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The developing CNS is exposed to physiological hypoxia, under which hypoxia-inducible factor α (HIFα) is stabilized and plays a crucial role in regulating neural development. The cellular and molecular mechanisms of HIFα in developmental myelination remain incompletely understood. A previous concept proposes that HIFα regulates CNS developmental myelination by activating the autocrine Wnt/β-catenin signaling in oligodendrocyte progenitor cells (OPCs). Here, by analyzing a battery of genetic mice of both sexes, we presented in vivo evidence supporting an alternative understanding of oligodendroglial HIFα-regulated developmental myelination. At the cellular level, we found that HIFα was required for developmental myelination by transiently controlling upstream OPC differentiation but not downstream oligodendrocyte maturation and that HIFα dysregulation in OPCs but not oligodendrocytes disturbed normal developmental myelination. We demonstrated that HIFα played a minor, if any, role in regulating canonical Wnt signaling in the oligodendroglial lineage or in the CNS. At the molecular level, blocking autocrine Wnt signaling did not affect HIFα-regulated OPC differentiation and myelination. We further identified HIFα-Sox9 regulatory axis as an underlying molecular mechanism in HIFα-regulated OPC differentiation. Our findings support a concept shift in our mechanistic understanding of HIFα-regulated CNS myelination from the previous Wnt-dependent view to a Wnt-independent one and unveil a previously unappreciated HIFα-Sox9 pathway in regulating OPC differentiation.
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Reactive oxygen and nitrogen species (ROS and RNS) generated by cold atmospheric-pressure plasma could damage genomic DNA, although the precise types of these DNA damage induced by plasma are poorly characterized. Understanding pl...
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Reactive oxygen and nitrogen species (ROS and RNS) generated by cold atmospheric-pressure plasma could damage genomic DNA, although the precise types of these DNA damage induced by plasma are poorly characterized. Understanding plasma-induced DNA damage will help to elucidate the biological effect of plasma and guide the application of plasma in ROS-based therapy. In this study, it was shown that ROS and RNS generated by physical plasma could efficiently induce DNA-protein crosslinks (DPCs) in bacteria, yeast, and human cells. An in vitro assay showed that plasma treatment resulted in the formation of covalent DPCs by activating proteins to crosslink with DNA. Mass spectrometry and hydroperoxide analysis detected oxidation products induced by plasma. DPC formation were alleviated by singlet oxygen scavenger, demonstrating the importance of singlet oxygen in this process. These results suggested the roles of DPC formation in DNA damage induced by plasma, which could improve the understanding of the biological effect of plasma and help to develop a new strategy in plasma-based therapy including infection and cancer therapy. ?2018, ?2018 Informa UK Limited, trading as Taylor & Francis Group.
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Purpose: T helper cells play essential roles in anti-tumor immune response. However, the postoperative changes of peripheral T cell subsets and their clinical significance in breast cancer patients remain largely unknown. Methods:...
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Purpose: T helper cells play essential roles in anti-tumor immune response. However, the postoperative changes of peripheral T cell subsets and their clinical significance in breast cancer patients remain largely unknown. Methods: We evaluated the perioperative changes of T lymphocyte subsets in invasive breast cancer (IBC) patients and breast fibroadenoma (BF) patients preoperatively (preop) and 6, 24, 72 hours postoperatively (POH6, POH24, and POH72). Proportions of CD3, CD4, CD8, T helper (Th) 1, Th2, Th17 cells, regulatory T cells (Treg), and CD4+/CD8+, Th1/Th2 ratio were detected by flow cytometry. Changes in T helper cell quantity were correlated to clinicopathological parameters. Furthermore, we explored the association between the perioperative variations of T cell subsets and disease-free survival (DFS) of IBC patients. Results: In IBC patients, Th1 cells diminished while Tregs elevated in postoperative 72 hours in the peripheral blood. In contrast, no significant perioperative changes of T cell subsets were observed in BF patients. Postoperative lower Th1 cells at POH 72 of IBC patients were correlated with greater tumor burden, HER2 positive and Ki67 positive. The increased Tregs at POH 72 of IBC patients were correlated with larger tumor size and HER2 positive. Th1 cell decline and Treg increment were both associated with shorter DFS in IBC patients. Conclusions: The variations of peripheral T helper cell subsets showed postoperative immunosuppression and were associated with poor prognosis in IBC patients. ?2017 Taylor & Francis.
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Let $u$ be a holomorphic function and $\varphi$ a holomorphic self-map of the open unit disk $\mathbb{D}$ in the complex plane. We provide new characterizations for the boundedness of the weighted composition operators $uC_{\varph...
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Let $u$ be a holomorphic function and $\varphi$ a holomorphic self-map of the open unit disk $\mathbb{D}$ in the complex plane. We provide new characterizations for the boundedness of the weighted composition operators $uC_{\varphi}$ from Zygmund type spaces to Bloch type spaces in $\mathbb{D}$ in terms of $u$, $ \varphi$, their derivatives, and $\varphi^n$, the $n$-th power of $\varphi$. Moreover, we obtain some similar estimates for the essential norms of the operators $uC_{\varphi}$, from which sufficient and necessary conditions of compactness of $uC_{\varphi}$ follows immediately.
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In this paper, we study multicast scheduling in the OpCut switch, a recently proposed hybrid optical/electronic switching architecture for transmitting high-volume traffic in core networks and parallel computers. First, we present...
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In this paper, we study multicast scheduling in the OpCut switch, a recently proposed hybrid optical/electronic switching architecture for transmitting high-volume traffic in core networks and parallel computers. First, we present a multicast scheduling algorithm called Guaranteed Latency Multicast Scheduling (GLMS) that considers the schedule of each packet for multiple time slots. We show that GLMS has several desirable features, such as guaranteed latency for all transmitted packets and adaptivity to transmission requirements. To relax the time constraint on computing a schedule, we further propose a parallel and pipeline processing architecture for GLMS that distributes the scheduling task to multiple pipelined processing stages, with $(N)$ processors in each stage, where $(N)$ is the switch size. Finally, by implementing it with simple combination logic circuits, we show that each processor can finish the scheduling for one time slot in $(O(1))$ time complexity. We evaluate the performance of GLMS extensively against statistical traffic models and real Internet traffic, and the results show that the proposed GLMS algorithm can achieve very low average packet latency with minimum packet drop ratio.
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Autophagy modulation is a potential therapeutic strategy for breast cancer, and a previous study indicated that metformin exhibits significant anti-carcinogenic activity. However, the ability of metformin to induce autophagy and i...
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Autophagy modulation is a potential therapeutic strategy for breast cancer, and a previous study indicated that metformin exhibits significant anti-carcinogenic activity. However, the ability of metformin to induce autophagy and its role in breast cancer cell death remains unclear. In this study, we exposed MCF-7 cells to different concentrations of metformin (2.5, 5, and 10 mM) for 48 h, and metformin-induced significant apoptosis in the MCF-7 cells. The expression levels of CL-PARP (poly(ADP-ribose) polymerase 1) and the ratio of BAX to BCL-2 were significantly increased. In addition to apoptosis, we showed that metformin increased autophagic flux in MCF-7 cells, as evidenced by the upregulation of LC3-II and downregulation of P62/SQSTM1. Moreover, pharmacological or genetic blocking of autophagy increased metformin-induced apoptosis, indicating a cytoprotective role of autophagy in metformin-treated MCF-7 cells. Mechanistically, metformin-induced TFE3(Ser321) dephosphorylation activated TFE3 nuclear translocation and increased of TFE3 reporter activity, which contributed to lysosomal biogenesis and the expression of autophagy-related genes and, subsequently, initiated autophagy in MCF-7 cells. Importantly, we found that metformin triggered the generation of reactive oxygen species (ROS) in MCF-7 cells. Furthermore, N-acetyl-l-cysteine (NAC), a ROS scavenger, abrogated the effects of metformin on TFE3-dependent autophagy. Notably, TFE3 expression positively correlated with breast cancer development and poor prognosis in patients. Taken together, these data demonstrate that blocking ROS-TFE3-dependent autophagy to enhance the activity of metformin warrants further attention as a treatment strategy for breast cancer. ?2018, ?2018 Informa UK Limited, trading as Taylor & Francis Group.
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