Applying qualitative and quantitative methods, this article explains the driving forces behind U.S. President Donald Trump's decision to withdraw from the Paris Agreement, assesses the impacts ...of this withdrawal on the compliance prospects of the agreement, and proposes how China should respond. The withdrawal undercuts the foundation of global climate governance and upsets the process of climate cooperation, and the impacts are manifold. The withdrawal undermines the universality of the Paris Agreement and impairs states' confidence in climate cooperation; it aggravates the leadership deficit in addressing global climate issues and sets a bad precedent for international climate cooperation. The withdrawal reduces other countries' emission space and raises their emission costs, and refusal to contribute to climate aid makes it more difficult for developing countries to mitigate and adapt to climate change. Cutting climate research funding will compromise the quality of future IPCC reports and ultimately undermine the scientific authority of future climate negotiations. China faces mounting pressure from the international community to assume global climate leadership after the U.S. withdraws, and this article proposes that China should reach the high ends of its domestic climate targets under the current Nationally Determined Contributions; internationally, China should facilitate the rebuilding of shared climate leadership, replacing the G2 with C5. Meanwhile, China needs to keep the U.S. engaged in climate cooperation.
The deceptive jamming technique can threaten a synthetic aperture radar (SAR) imaging system by repeatedly transmitting copied radar signals back to the radar. A conventional phased array can ...generate only an angle-dependent beam and cannot distinguish the jammer from other targets. Instead, a frequency diverse array (FDA) can offer a range-angle-dependent beampattern by introducing small frequency offsets to array elements, which can be adopted to distinguish signals from different range cells. Thus, considering that the position of the jammer is unknown, it is necessary to suppress the range peak sidelobe as much as possible. To lower this value, this paper proposes a weighted FDA to achieve the optimal solution at the expense of raising other range sidelobes.
We develop a general framework to analyze the controllability of multiplex networks using multiple-relation networks and multiple-layer networks with interlayer couplings as two classes of ...prototypical systems. In the former, networks associated with different physical variables share the same set of nodes and in the latter, diffusion processes take place. We find that, for a multiple-relation network, a layer exists that dominantly determines the controllability of the whole network and, for a multiple-layer network, a small fraction of the interconnections can enhance the controllability remarkably. Our theory is generally applicable to other types of multiplex networks as well, leading to significant insights into the control of complex network systems with diverse structures and interacting patterns.
The Jiulong River estuary, located in the southeastern China, suffered from metal pollution due to industrial effluent releases. Mixing of effluent and estuarine water may have significantly affected ...the size distribution of trace metals and their environmental fate. In the present study, colloidal size distribution of organic matter and selected metals were quantified using asymmetric flow field-flow fractionation (AF4) and ICP-MS. We demonstrated a dominance of dissolved metals in the 1–10kDa fraction, and metals such as Cu, Zn, Ni, Co, Pb, Cd and Mn were mostly regulated by terrestrial fulvic acid. The larger inorganic colloids played a limited role, although Fe reduction was likely to affect the size partitioning of colloidal Mn. The holding pond represented a source of trace metals and chromophoric and humic-like dissolved organic matter to the estuary. Scavenging or removal behavior became evident following the intermittent mixing, and the small sized colloidal organic complexes were responsible for binding and stabilizing trace metals. Variations in particle size distributions indicated different sources, fates and geochemical controls of the metals. Our results highlighted the impacts of both natural and anthropogenic processes on the transformation of trace metals among phases in this dynamic estuary system.
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•Colloidal size distribution of metals was quantified using asymmetric flow field-flow fractionation and ICP-MS.•Dominance of dissolved metals in the 1–10kDa fraction of estuarine waters mixed with industrial effluents•Small sized colloidal organic complexes were responsible for binding and stabilizing trace metals.•Both natural and anthropogenic processes affected the transformation of metals among phases in the estuary system.
Passive mixers in microfluidic systems: A review Lee, Chia-Yen; Wang, Wen-Teng; Liu, Chan-Chiung ...
Chemical engineering journal (Lausanne, Switzerland : 1996),
03/2016, Letnik:
288
Journal Article
Recenzirano
•The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices.•Passive micromixers utilize no energy input other than the pressure head used to ...drive the fluid flow at a constant rate.•Many passive mixers have been proposed to facilitate this task over the past five years.
The aim of microfluidic mixing is to achieve a thorough and rapid mixing of multiple samples in microscale devices. In such devices, sample mixing is essentially achieved by enhancing the diffusion effect between the different species flows. Passive micromixers utilize no energy input other than the pressure head used to drive the fluid flow at a constant rate. Under such conditions, the flow has a laminar characteristic, and hence mixing relies mainly on the induction of a chaotic advection effect to increase the contact surface and contact time between the species flows. Many passive mixers have been proposed to facilitate this task over the past five years. The details of these mixers are briefly described in the following review.
Polyolefin thermoplastic elastomers (TPE‐Os) are high‐performance polyolefins consisting of both plastic and rubber phases. Compared with other thermoplastic elastomers, the TPE‐Os possess better ...chemical stability, transparency, re‐processability, and electrical insulation, which renders their broad applications possible. By manipulating chain structures and topologies of the TPE‐Os, differently structured polyolefins with improved thermal and mechanical properties have been developed, including ethylene and α‐olefin random copolymers (POEs), olefin block copolymers (OBCs), comb‐shaped polyolefin elastomers (CPOEs), and dynamically cross‐linked polyolefin elastomers. Herein, we review the synthesis of the POE, OBC, CPOE, and dynamical cross‐linked polyolefin elastomer, including the catalyst systems, polymerization techniques, processes, and kinetic modelling. The characterization of the TPE‐Os and the relationships between the TPE‐O chain structure, aggregated state, and product performance are discussed. The future development of higher‐performance TPE‐Os is envisaged.
Development of high‐performance polyolefin thermoplastic elastomers from structure customization
Directed energy deposition (DED) is an important additive manufacturing method for producing or repairing high-end and high-value equipment. Meanwhile, the lack of reliable and uniform qualities is a ...key problem in DED applications. With the development of sensing devices and control systems, in situ monitoring (IM) and adaptive control (IMAC) technology is an effective method to enhance the reliability and repeatability of DED. In this paper, we review current IM technologies in IMAC for metal DED. First, this paper describes the important sensing signals and equipment to exhibit the research status in detail. Meanwhile, common problems that arise when gathering these signals and resolvent methods are presented. Second, process signatures obtained from sensing signals and transfer approaches from sensing signals for processing signatures are shown. Third, this work reviews the developments of the IM of product qualities and illustrates ways to realize quality monitoring. Lastly, this paper specifies the main existing problems and future research of IM in metal DED.
Abstract
Background
Blueberries (
Vaccinium sp.
) are native to North America and breeding efforts to improve blueberry fruit quality are focused on improving traits such as increased firmness, ...enhanced flavor and greater shelf-life. Such efforts require additional genomic resources, especially in southern highbush and rabbiteye blueberries.
Results
We generated the first full-length fruit transcriptome for the southern highbush and rabbiteye blueberry using the cultivars, Suziblue and Powderblue, respectively. The transcriptome was generated using the Pacific Biosciences single-molecule long-read isoform sequencing platform with cDNA pooled from seven stages during fruit development and postharvest storage. Raw reads were processed through the Isoseq pipeline and full-length transcripts were mapped to the ‘Draper’ genome with unmapped reads collapsed using Cogent. Finally, we identified 16,299 and 15,882 non-redundant transcripts in ‘Suziblue’ and ‘Powderblue’ respectively by combining the reads mapped to Northern Highbush blueberry ‘Draper’ genome and Cogent analysis. In both cultivars, > 80% of sequences were longer than 1,000 nt, with the median transcript length around 1,700 nt. Functionally annotated transcripts using Blast2GO were > 92% in both ‘Suziblue’ and ‘Powderblue’ with overall equal distribution of gene ontology (GO) terms in the two cultivars. Analyses of alternative splicing events indicated that around 40% non-redundant sequences exhibited more than one isoform. Additionally, long non-coding RNAs were predicted to represent 5.6% and 7% of the transcriptomes in ‘Suziblue’ and ‘Powderblue’, respectively. Fruit ripening is regulated by several hormone-related genes and transcription factors. Among transcripts associated with phytohormone metabolism/signaling, the highest number of transcripts were related to abscisic acid (ABA) and auxin metabolism followed by those for brassinosteroid, jasmonic acid and ethylene metabolism. Among transcription factor-associated transcripts, those belonging to ripening-related APETALA2/ethylene-responsive element-binding factor (AP2/ERF), NAC (NAM, ATAF1/2 and CUC2), leucine zipper (HB-zip), basic helix-loop-helix (bHLH), MYB (v-MYB, discovered in avian myeloblastosis virus genome) and MADS-Box gene families, were abundant.
Further we measured three fruit ripening quality traits and indicators ABA, and anthocyanin concentration, and texture during fruit development and ripening. ABA concentration increased during the initial stages of fruit ripening and then declined at the Ripe stage, whereas anthocyanin content increased during the final stages of fruit ripening in both cultivars. Fruit firmness declined during ripening in ‘Powderblue’. Genes associated with the above parameters were identified using the full-length transcriptome. Transcript abundance patterns of these genes were consistent with changes in the fruit ripening and quality-related characteristics.
Conclusions
A full-length, well-annotated fruit transcriptome was generated for two blueberry species commonly cultivated in the southeastern United States. The robustness of the transcriptome was verified by the identification and expression analyses of multiple fruit ripening and quality–regulating genes. The full-length transcriptome is a valuable addition to the blueberry genomic resources and will aid in further improving the annotation. It will also provide a useful resource for the investigation of molecular aspects of ripening and postharvest processes.
Nearly half of all Asian non-small cell lung cancer (NSCLC) patients harbour epidermal growth factor receptor (EGFR) mutations, and first-generation EGFR tyrosine kinase inhibitors (TKIs) are one of ...the first-line treatments that have improved the outcomes of these patients. Unfortunately, 20% of these patients can not benefit from the treatment. The basis of this primary resistance is poorly understood. Therefore, overcoming EGFR-TKI primary resistance and maintaining the efficacy of TKIs has become a key issue. β-Elemene, a sesquiterpene compound extracted from Curcuma aromatica Salisb. (wenyujing), has shown potent antitumor effects. In this research, we found that β-elemene combined with erlotinib enhanced the cytotoxicity of erlotinib to primary EGFR-TKI-resistant NSCLC cells with EGFR mutations and that ferroptosis was involved in the antitumor effect of the combination treatment. We found that lncRNA H19 was significantly downregulated in primary EGFR-TKI-resistant NSCLC cell lines and was upregulated by the combination treatment. Overexpression or knockdown of H19 conferred sensitivity or resistance to erlotinib, respectively, in both in vitro and in vivo studies. The high level of H19 enhanced the cytotoxicity of erlotinib by inducing ferroptosis. In conclusion, our data showed that β-elemene combined with erlotinib could enhance sensitivity to EGFR-TKIs through induction of ferroptosis via H19 in primary EGFR-TKI-resistant lung cancer, providing a promising strategy to overcome EGFR-TKI resistance in NSCLC patients.
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Carbohydrate‐based drug discovery has gained more and more attention during the last few decades. Resin glycoside is a kind of novel and complex glycolipids mainly distributed in plants of the family ...Convolvulaceae. Over the last decade, a number of natural resin glycosides and derivatives have been isolated and identified, and exhibited a broad spectrum of biological activities, such as cytotoxic, multidrug‐resistant reversal on both microbial pathogens and mammalian cancer cells, antivirus, anticonvulsant, antidepressant, sedative, vasorelaxant, laxative, and α‐glucosidase inhibitory effects, indicating their potential as lead compounds for drug discovery. A systematic review of the literature studies was carried out to summarize the chemistry and biological activity of resin glycosides from Convolvulaceae species, based on various data sources such as PubMed, Web of Science, Scopus, and Google scholar. The keyword “Convolvulaceae” was paired with “resin glycoside,” “glycosidic acid,” “glycolipid,” or “oligosaccharide,” and the references published between 2009 and June 2021 were covered. In this article, we comprehensively reviewed the structures of 288 natural resin glycoside and derivatives newly reported in the last decade. Moreover, we summarized the biological activities and mechanisms of action of the resin glycosides with pharmaceutical potential. Taken together, great progress has been made on the chemistry and biological activity of resin glycosides from Convolvulaceae species, however, more exploratory research is still needed, especially on the mechanism of action of the biological activities.
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