Chan‐Lam reactions hold promise as one of the most efficient synthetic methods to construct various carbon‐heteroatom or carbon‐carbon bonds. Recently, a series of Chan‐Lam reactions were developed ...to boost organic synthesis. Herein, we summarized the latest research and progress of Chan‐Lam coupling to illustrate its synthetic value.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Since the outbreak of severe acute respiratory syndrome (SARS) 18 years ago, a large number of SARS-related coronaviruses (SARSr-CoVs) have been discovered in their natural reservoir host, bats
. ...Previous studies have shown that some bat SARSr-CoVs have the potential to infect humans
. Here we report the identification and characterization of a new coronavirus (2019-nCoV), which caused an epidemic of acute respiratory syndrome in humans in Wuhan, China. The epidemic, which started on 12 December 2019, had caused 2,794 laboratory-confirmed infections including 80 deaths by 26 January 2020. Full-length genome sequences were obtained from five patients at an early stage of the outbreak. The sequences are almost identical and share 79.6% sequence identity to SARS-CoV. Furthermore, we show that 2019-nCoV is 96% identical at the whole-genome level to a bat coronavirus. Pairwise protein sequence analysis of seven conserved non-structural proteins domains show that this virus belongs to the species of SARSr-CoV. In addition, 2019-nCoV virus isolated from the bronchoalveolar lavage fluid of a critically ill patient could be neutralized by sera from several patients. Notably, we confirmed that 2019-nCoV uses the same cell entry receptor-angiotensin converting enzyme II (ACE2)-as SARS-CoV.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Large-scale blackouts typically result from cascading failure in power systems operation. Their mitigation in power system planning calls for the development of methods and algorithms that assess the ...risk of cascading failure due to relay overtripping, short-circuits induced by overgrown vegetation, voltage sags, line and transformer overloading, transient instabilities, voltage collapse, to cite a few. This paper describes such a method based on composite power system reliability evaluation via sequential Monte Carlo simulation. One of the impediments of the study of these phenomena is the prohibitively large computational burden involved by the simulations. To overcome this difficulty, importance sampling technique utilizing the Weibull distribution is applied to power generator outages. Another method combing importance sampling and antithetic variates together is implemented as well. It is shown that both methods noticeably reduce the number of samples that need to be investigated while maintaining the accuracy at a given level. It is found that the combined method outperforms importance sampling to certain extent. To illustrate the developed techniques, two case studies are conducted and analyzed on the IEEE one-area and three-area reliability test system.
Battery-Free Wireless Sensor Networks (BF-WSNs) have been attracting increasing interests in the recent years. To reduce the latency in BF-WSNs, the Minimum Latency Aggregation Scheduling (MLAS) ...problem with coverage requirement <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula> is proposed recently, which tries to choose <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula> percent of nodes for communication and aggregation. In the existing method, the authors try to select nodes adaptively according to their energy status and schedule these nodes to achieve the minimum latency. Unfortunately, it cannot guarantee the distribution of the aggregated nodes and may result in these nodes being squeezed in a small area and a poor aggregation quality. Thus, we re-investigate the <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>-coverage MLAS problem in this article, which can guarantee that the aggregated nodes are distributed evenly. Firstly, the 1-coverage MLAS problem, in which each node can be covered by at least one aggregated node, is studied. To reduce the latency, we intertwine the selection of aggregated nodes and the computation of a collision-free communication schedule simultaneously. Two algorithms are proposed by scheduling the communication tasks in the bottom-up and top-down manner respectively. Secondly, to satisfy the arbitrary coverage requirement <inline-formula> <tex-math notation="LaTeX">q </tex-math></inline-formula>, three algorithms are proposed to guarantee the aggregated nodes are evenly distributed in the network with a low latency. Additionally, the method to extend the proposed algorithms for the BF-WSNs with multiple channels is also studied. The theoretical analysis and simulation results verify that the proposed algorithms have high performance in terms of latency.
The efficient and selective elimination of damaged or excessive mitochondria in response to bioenergetic and environmental cues is critical for maintaining a healthy and appropriate population of ...mitochondria. Mitophagy is considered to be the central mechanism of mitochondrial quality and quantity control. Atg32, a mitophagy receptor in yeast, recruits mitochondria targeted for degradation into the isolation membrane via both direct and indirect interactions with Atg8. In mammals, different mitophagy effectors, including the mitophagy receptors NIX, BNIP3 and FUDNC1 and the PINK1/Parkin pathway, have been identified to participate in the selective clearance of mitochondria. One common feature of mitophagy receptors is that they harbor an LC3-interacting region (LIR) that interacts with LC3, thus promoting the sequestration of mitochondria into the isolation membrane. Additionally, both receptor- and Parkin/PINK1-mediated mitophagy have been found to be regulated by reversible phosphorylation. Here, we review the recent progress in the understanding of the molecular mechanisms involved in selective mitophagy at multiple levels. We also discuss different mitophagy receptors from an evolutionary perspective and highlight the specific functions of and possible cooperation between distinct mechanisms of mitophagy. This article is part of a Special Issue entitled: Mitophagy.
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•FUNDC1 is a new mammalian mitophagy receptor that mediates mitophagy via its direct interaction with LC3.•Atg32 functions as a mitophagy receptor in yeast and shares common features with FUNDC1.•Different mitophagy pathways may cooperate to promote mitophagy under mitochondrial stress conditions.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Liquid-liquid phase separation (LLPS) explains many intracellular activities, but its role in extracellular functions has not been studied to the same extent. Here we report how LLPS mediates the ...extracellular function of galectin-3, the only monomeric member of the galectin family. The mechanism through which galectin-3 agglutinates (acting as a "bridge" to aggregate glycosylated molecules) is largely unknown. Our data show that its N-terminal domain (NTD) undergoes LLPS driven by interactions between its aromatic residues (two tryptophans and 10 tyrosines). Our lipopolysaccharide (LPS) micelle model shows that the NTDs form multiple weak interactions to other galectin-3 and then aggregate LPS micelles. Aggregation is reversed when interactions between the LPS and the carbohydrate recognition domains are blocked by lactose. The proposed mechanism explains many of galectin-3's functions and suggests that the aromatic residues in the NTD are interesting drug design targets.
Mitophagy plays pivotal roles in the selective disposal of unwanted mitochondria, and accumulation of damaged mitochondria has been linked to aging-related diseases. However, definitive proof that ...mitophagy regulates mitochondrial quality in vivo is lacking. It is also largely unclear whether damaged mitochondria are the cause or just the consequence of these diseases. We previously showed that FUNDC1 is a mitophagy receptor that interacts with LC3 to mediate mitophagy in response to hypoxia in cultured cells. We established Fundc1 knockout mouse models and used genetic and biochemical approaches, including a synthetic peptide that blocks the FUNDC1-LC3 interaction, to demonstrate that mitophagy regulates both mitochondrial quantity and quality in vivo in response to hypoxia or hypoxic conditions caused by ischemia-reperfusion (I/R) heart injury. We found that hypoxic mitophagy regulates platelet activities. Furthermore, we found that hypoxic preconditioning induces FUNDC1-dependent mitophagy in platelets and reduces I/R-induced heart injury, suggesting a new strategy to protect cardiac function and fight cardiovascular diseases.
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Dynamics of associative polymers Zhang, Zhijie; Chen, Quan; Colby, Ralph H
Soft matter,
2018, Volume:
14, Issue:
16
Journal Article
Peer reviewed
Current progress in understanding the dynamics of associating polymers is reviewed, with examples including both ionic and hydrogen bonding associations. A particular emphasis is placed on ...quantification of the strength of the interaction that sets the association lifetime. Knowledge of the interaction energy and the number density of associating groups allows a rational understanding of the linear viscoelastic response of many associating polymers.
Current progress in understanding the dynamics of associating polymers is reviewed, with examples including both ionic and hydrogen bonding associations.
The enantioselective N‐heterocyclic carbene catalyzed 3+3 annulation of α‐bromoenals by dynamic kinetic resolution (DKR) of enamines and normal resolution of α,α‐disubstituted imines were developed. ...The corresponding substituted dihydropyridones were isolated in good yields with excellent diastereo‐ and enantioselectivities, and a high selective factor (up to 83) was realized for the resolution of α,α‐disubstituted imines.
The S factor: The enantioselective N‐heterocyclic carbene (NHC) catalyzed 3+3 annulation of α‐bromoenals by dynamic kinetic resolution (DKR) of enamines, and normal resolution of α,α‐disubstituted imines were developed. The corresponding substituted dihydropyridones were isolated in good yields with excellent diastereo‐ and enantioselectivities, and a high selectivity factor was realized for the resolution of α,α‐disubstituted imines.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
This technical note firstly presents a sufficient and necessary condition for the robust asymptotical stability of fractional-order interval systems with the fractional order α satisfying 0 < α < 1. ...And then a sufficient condition for the robust asymptotical stabilization of such fractional-order interval systems is derived. All the results are obtained in terms of linear matrix inequalities. Finally, two illustrative examples are given to show that our results are effective for checking the robust stability and designing the robust stabilizing controller for fractional-order interval systems.
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