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"Yuan, Ping"
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Diplomacy of quasi-alliances in the Middle East
Quasi-alliance refers to the ideation, mechanism and behavior of policy-makers to carry out security cooperation through informal political and security arrangements. As a \"gray zone\" between alliance and neutrality, quasi-alliance is a hidden national security statecraft. Based on declassified archives and secondary sources, this book probes the theory and practice of quasi-alliances in the Middle East. Four cases are chosen to test the hypotheses of quasi-alliance, one of which is the Anglo-French-Israeli quasi-alliance during the Suez Canal War of 1956.
Book
Metabolomics and transcriptomics unravel the mechanism of browning resistance in Agaricus bisporus
Agaricus bisporus is widely consumed on the world market. The easy browning of mushroom surface is one of the most intuitive factors affecting consumer purchase. A certain cognition on browning mechanism has been made after years of research. At present, people slow down the browning of mushrooms mainly by improving preservation methods. In addition, breeding is also a reliable way. In the production practice, we have identified some browning-resistant varieties, and we selected a browning-resistant variety to compare with an ordinary variety to reveal the resistance mechanism. Using transcriptomics and metabolomics, the differences in gene expression and metabolite levels were revealed, respectively. The results showed that differentially expressed genes (DEGs) like AbPPO4 , AbPPO3 and AbPPO2 were differently expressed and these DEGs were involved in many pathways related to browning. The expression of AbPPO expression play an important role in the browning of A . bisporus and multiple PPO family members are involved in the regulation of browning. However, the resistance to browning cannot be judged only by the expression level of AbPPOs . For metabolomics, most of the different metabolites were organic acids. These organic acids had a higher level in anti-browning (BT) than easy-browning varieties (BS), although the profile was very heterogeneous. On the contrary, the content of trehalose in BS was significantly higher than that in BT. Higher organic acids decreased pH and further inhibited PPO activity. In addition, the BS had a higher content of trehalose, which might play roles in maintaining PPO activity. The difference of browning resistance between BS and BT is mainly due to the differential regulation mechanism of PPO.
Journal Article
Ruthenium atomically dispersed in carbon outperforms platinum toward hydrogen evolution in alkaline media
Hydrogen evolution reaction is an important process in electrochemical energy technologies. Herein, ruthenium and nitrogen codoped carbon nanowires are prepared as effective hydrogen evolution catalysts. The catalytic performance is markedly better than that of commercial platinum catalyst, with an overpotential of only −12 mV to reach the current density of 10 mV cm
-2
in 1 M KOH and −47 mV in 0.1 M KOH. Comparisons with control experiments suggest that the remarkable activity is mainly ascribed to individual ruthenium atoms embedded within the carbon matrix, with minimal contributions from ruthenium nanoparticles. Consistent results are obtained in first-principles calculations, where RuC
x
N
y
moieties are found to show a much lower hydrogen binding energy than ruthenium nanoparticles, and a lower kinetic barrier for water dissociation than platinum. Among these, RuC
2
N
2
stands out as the most active catalytic center, where both ruthenium and adjacent carbon atoms are the possible active sites.
Electrochemical water splitting is promising for sustainable energy, but relies on development of electrocatalysts for hydrogen evolution. Here the authors report nitrogen- and ruthenium-codoped carbon nanowires in which ruthenium atoms in a carbon matrix drive electrocatalysis of hydrogen evolution
Journal Article
Mammalian WTAP is a regulatory subunit of the RNA N6-methyladenosine methyltransferase
The methyltransferase like 3 （METTL3）-containing methyltransferase complex catalyzes the N6-methyladenosine （m6A） formation, a novel epitranscriptomic marker; however, the nature of this complex remains largely unknown. Here we report two new components of the human m6A methyltransferase complex, Wilms＇ tumor 1-associating protein （WTAP） and methyltransferase like 14 （METTL14）. WTAP interacts with METTL3 and METTL14, and is required for their localization into nuclear speckles enriched with pre-mRNA processing factors and for catalytic ac- tivity of the m6A methyltransferase in vivo. The majority of RNAs bound by WTAP and METTL3 in vivo represent mRNAs containing the consensus m6A motif. In the absence of WTAP, the RNA-binding capability of METTL3 is strongly reduced, suggesting that WTAP may function to regulate recruitment of the m6A methyltransferase complex to mRNA targets. Furthermore, transcriptomic analyses in combination with photoactivatable-ribonucleoside-en- hanced crosslinking and immunoprecipitation （PAR-CLIP） illustrate that WTAP and METTL3 regulate expression and alternative splicing of genes involved in transcription and RNA processing. Morpholino-mediated knockdown targeting WTAP and/or METTL3 in zebrafish embryos caused tissue differentiation defects and increased apoptosis. These findings provide strong evidence that WTAP may function as a regulatory subunit in the m6A methyltransferase complex and play a critical role in epitranscriptomic regulation of RNA metabolism.
Journal Article
Near-infrared optogenetic engineering of photothermal nanoCRISPR for programmable genome editing
We herein report an optogenetically activatable CRISPR-Cas9 nanosystem for programmable genome editing in the second near-infrared (NIR-II) optical window. The nanosystem, termed nanoCRISPR, is composed of a cationic polymer-coated Au nanorod (APC) and Cas9 plasmid driven by a heat-inducible promoter. The APC not only serves as a carrier for intracellular plasmid delivery but also can harvest external NIR-II photonic energy and convert it into local heat to induce the gene expression of the Cas9 endonuclease. Due to high transfection activity, the APC shows strong ability to induce a significant level of disruption in different genomic loci upon optogenetic activation. Moreover, the precise control of genome-editing activity can be simply programmed by finely tuning exposure time and irradiation time in vitro and in vivo and also enables editing at multiple time points, thus proving the sensitivity and inducibility of such an editing modality. The NIR-II optical feature of nanoCRISPR enables therapeutic genome editing at deep tissue, by which treatment of deep tumor and rescue of fulminant hepatic failure are demonstrated as proof-of-concept therapeutic examples. Importantly, this modality of optogenetic genome editing can significantly minimize the off-target effect of CRISPR-Cas9 in most potential off-target sites. The optogenetically activatable CRISPR-Cas9 nanosystem we have developed offers a useful tool to expand the current applications of CRISPR-Cas9, and also defines a programmable genome-editing strategy toward high precision and spatial specificity.
Journal Article
Constraining tectonic uplift and advection from the main drainage divide of a mountain belt
One of the most conspicuous features of a mountain belt is the main drainage divide. Divide location is influenced by a number of parameters, including tectonic uplift and horizontal advection. Thus, the topography of mountain belts can be used as an archive to extract tectonic information. Here we combine numerical landscape evolution modelling and analytical solutions to demonstrate that mountain asymmetry, determined by the location of the main drainage divide, increases with increasing uplift gradient and advection velocity. Then, we provide a conceptual framework to constrain the present or previous tectonic uplift and advection of a mountain belt from the location and migration direction of its main drainage divide. Furthermore, we apply our model to Wula Shan horst, Northeastern Sicily, and Southern Taiwan.
One of the most conspicuous features of a mountain belt is the main drainage divide. Here, the authors constrain the tectonic uplift and advection of a mountain belt from the location and migration direction of its main drainage divide.
Journal Article
Quantifying the nonclassicality of pure dephasing
One of the central problems in quantum theory is to characterize, detect, and quantify quantumness in terms of classical strategies. Dephasing processes, caused by non-dissipative information exchange between quantum systems and environments, provides a natural platform for this purpose, as they control the quantum-to-classical transition. Recently, it has been shown that dephasing dynamics itself can exhibit (non)classical traits, depending on the nature of the system-environment correlations and the related (im)possibility to simulate these dynamics with Hamiltonian ensembles–the classical strategy. Here we establish the framework of detecting and quantifying the nonclassicality for pure dephasing dynamics. The uniqueness of the canonical representation of Hamiltonian ensembles is shown, and a constructive method to determine the latter is presented. We illustrate our method for qubit, qutrit, and qubit-pair pure dephasing and describe how to implement our approach with quantum process tomography experiments. Our work is readily applicable to present-day quantum experiments.
The presence of processes that cannot be simulated classically in open quantum system dynamics is acknowledged, but an exact quantifier for this non-classical character is still missing. Here, the authors provide a quantitative measure of non-classicality for purely dephasing evolutions.
Journal Article
Protective effect of L-pipecolic acid on constipation in C57BL/6 mice based on gut microbiome and serum metabolomic
Background
Functional constipation (FC) in children affects their growth, development and quality of life. L-pipecolic acid (L-PA) was decreased in FC children based on gut microbiome and serum metabolomic. In this study, loperamide-induced constipation in mice was used to evaluate the effects of L-PA on constipated mice.
Method
26 FC and 28 healthy children were recruited. Stool samples and serum samples were subjected to 16S rDNA sequencing and ultra-performance liquid chromatography/quadrupole time of flight (UPLC-Q/TOF-MS) approach, respectively. A loperamide-induced mouse constipation model was developed, and all mice were randomly divided into control (Con), loperamide (Lop) and L-PA (Lop + L-PA) treatment groups (6 mice per group). The mice in the Lop + L-PA group were given L-PA (250 mg/kg, once a day) and loperamide; the Lop group was given loperamide for 1 week, and the Con group was given saline. The fecal parameters and intestinal motility of mice in each group were detected. serum 5-HT levels and colon 5-HT expression were detected by ELISA and immunohistochemistry, respectively; qRT-PCR was used to detect the expression of AQP3 and 5-HT4R mRNA in each group.
Results
45 differential metabolites and 18 significantly different microbiota were found in FC children. The α and β diversity of gut microbiota in FC children was significantly reduced. Importantly, serum L-PA was significantly reduced in FC children. The KEGG pathway enrichment were mainly enriched in fatty acid biosynthesis, lysine degradation, and choline metabolism. L-PA was negatively associated with
Ochrobactrum
, and N6, N6, N6-trimethyl-l-lysine was positively associated with
Phascolarcrobacterium
. In addition, L-PA improved the fecal water content, intestinal transit rate, and increased the serum 5-HT levels in constipated mice. Moreover, L-PA increased the expression of 5-HT4R, reduced AQP3, and regulated constipation-associated genes.
Conclusions
Gut microbiota and serum metabolites were significantly altered in children with FC. The abundance of
Phascolarctobacterium
and
Ochrobactrum
and serum L-PA content were decreased in FC children. L-PA was found to alleviate the fecal water content, increase intestinal transit rate and the first black stool defecation time. L-PA improved constipation by increasing 5-HT and 5-HT4R expression while down-regulating AQP3 expression.
Journal Article
Identification of superior parental lines for biparental crossing via genomic prediction
A parental selection approach based on genomic prediction has been developed to help plant breeders identify a set of superior parental lines from a candidate population before conducting field trials. A classical parental selection approach based on genomic prediction usually involves truncation selection, i.e., selecting the top fraction of accessions on the basis of their genomic estimated breeding values (GEBVs). However, truncation selection inevitably results in the loss of genomic diversity during the breeding process. To preserve genomic diversity, the selection of closely related accessions should be avoided during parental selection. We thus propose a new index to quantify the genomic diversity for a set of candidate accessions, and analyze two real rice ( Oryza sativa L.) genome datasets to compare several selection strategies. Our results showed that the pure truncation selection strategy produced the best starting breeding value but the least genomic diversity in the base population, leading to less genetic gain. On the other hand, strategies that considered only genomic diversity resulted in greater genomic diversity but less favorable starting breeding values, leading to more genetic gain but unsatisfactorily performing recombination inbred lines (RILs) in progeny populations. Among all strategies investigated in this study, compromised strategies, which considered both GEBVs and genomic diversity, produced the best or second-best performing RILs mainly because these strategies balance the starting breeding value with the maintenance of genomic diversity.
Journal Article
Carbon doping switching on the hydrogen adsorption activity of NiO for hydrogen evolution reaction
Hydrogen evolution reaction (HER) is more sluggish in alkaline than in acidic media because of the additional energy required for water dissociation. Numerous catalysts, including NiO, that offer active sites for water dissociation have been extensively investigated. Yet, the overall HER performance of NiO is still limited by lacking favorable H adsorption sites. Here we show a strategy to activate NiO through carbon doping, which creates under-coordinated Ni sites favorable for H adsorption. DFT calculations reveal that carbon dopant decreases the energy barrier of Heyrovsky step from 1.17 eV to 0.81 eV, suggesting the carbon also serves as a hot-spot for the dissociation of water molecules in water-alkali HER. As a result, the carbon doped NiO catalyst achieves an ultralow overpotential of 27 mV at 10 mA cm
−2
, and a low Tafel slope of 36 mV dec
−1
, representing the best performance among the state-of-the-art NiO catalysts.
While H
2
evolution from water may serve as a renewable source of fuel, there are a limited number of catalysts that are stable and active in alkaline media. Here, authors find carbon doping of NiO to increase the number of favorable sites for H
2
evolution and boost electrocatalytic performances.
Journal Article