Mapping and candidate-gene screening of the novel Turnip mosaic virus resistance gene retr02 in Chinese cabbage (Brassica rapa L.)

The extreme resistance to Turnip mosaic virus observed in the Chinese cabbage (Brassica rapa) line, BP8407, is monogenic and recessive. Bulked segregant analysis was carried out to identify simple sequence repeat and Indel markers linked to this recessive resistance gene, termed recessive Turnip mosaic virus resistance 02 (retr02). Mapping of PCR-specific Indel markers on 239 individuals of a BP8407 × Ji Zao Chun F 2 population, located this resistance gene to a 0.9-cM interval between two Indel markers (BrID10694 and BrID101309) and in scaffold000060 or scaffold000104 on chromosome A04 of the B. rapa genome. Eleven eukaryotic initiation factor 4E (eIF4E) and 14 eukaryotic initiation factor 4G (eIF4G) genes are predicted in the B. rapa genome. A candidate gene, Bra035393 on scaffold000104, was predicted within the mapped resistance locus. The gene encodes the eIF(iso)4E protein. Bra035393 was sequenced in BP8407 and Ji Zao Chun. A polymorphism (A/G) was found in exon 3 between BP8407 and Ji Zao Chun. This gene was analysed in four resistant and three susceptible lines. A correlation was observed between the amino acid substitution (Gly/Asp) in the eIF(iso)4E protein and resistance/susceptibility. eIF(iso)4E has been shown previously to interact with the TuMV genome-linked protein, VPg

Quasi-Solid-State Ion-Conducting Arrays Composite Electrolytes with Fast Ion Transport Vertical-Aligned Interfaces for All-Weather Practical Lithium-Metal Batteries

The rapid improvement in the gel polymer electrolytes (GPEs) with high ionic conductivity brought it closer to practical applications in solid-state Li-metal batteries. The combination of solvent and polymer enables quasi-liquid fast ion transport in the GPEs. However, different ion transport capacity between solvent and polymer will cause local nonuniform Li$^+$ distribution, leading to severe dendrite growth. In addition, the poor thermal stability of the solvent also limits the operating-temperature window of the electrolytes. Optimizing the ion transport environment and enhancing the thermal stability are two major challenges that hinder the application of GPEs. Here, a strategy by introducing ion-conducting arrays (ICA) is created by vertical-aligned montmorillonite into GPE. Rapid ion transport on the ICA was demonstrated by $^6$Li solid-state nuclear magnetic resonance and synchrotron X-ray diffraction, combined with computer simulations to visualize the transport process. Compared with conventional randomly dispersed fillers, ICA provides continuous interfaces to regulate the ion transport environment and enhances the tolerance of GPEs to extreme temperatures. Therefore, GPE/ICA exhibits high room-temperature ionic conductivity (1.08 mS cm$^{−1}$) and long-term stable Li deposition/stripping cycles (> 1000 h). As a final proof, Li||GPE/ICA||LiFePO$_4$ cells exhibit excellent cycle performance at wide temperature range (from 0 to 60 °C), which shows a promising path toward all-weather practical solid-state batteries

Dynamic covalent crosslinked hyaluronic acid hydrogels and nanomaterials for biomedical applications

Hyaluronic acid (HA), one of the main components of the extracellular matrix (ECM), is extensively used in the design of hydrogels and nanoparticles for different biomedical applications due to its critical role in vivo, degradability by endogenous enzymes, and absence of immunogenicity. HA-based hydrogels and nanoparticles have been developed by utilizing different crosslinking chemistries. The development of such crosslinking chemistries indicates that even subtle differences in the structure of reactive groups or the procedure of crosslinking may have a profound impact on the intended mechanical, physical and biological outcomes. There are widespread examples of modified HA polymers that can form either covalently or physically crosslinked biomaterials. More recently, studies have been focused on dynamic covalent crosslinked HA-based biomaterials since these types of crosslinking allow the preparation of dynamic structures with the ability to form in situ, be injectable, and have self-healing properties. In this review, HA-based hydrogels and nanomaterials that are crosslinked by dynamic-covalent coupling (DCC) chemistry have been critically assessed.publishedVersionPeer reviewe

Advanced fuel cell based on Perovskite La-SrTiO3 semiconductor as the electrolyte with superoxide-ion conduction

A solid oxide fuel cell’s (SOFC) performance is largely determined by the ionic-conducting electrolyte. A novel approach is presented for using the semiconductor perovskite LaR0.25RSrR0.75RTiOR3R (LST) as the electrolyte by creating surface superionic conduction, and the authors show that the LST electrolyte can deliver superior power density, 908.2 mW·cmP-2P at just 550 °C. The prepared LST materials formed a heterostructure including an insulating core and a super ionic conducting surface layer. The rapid ion transport along the surfaces or grain boundaries was identified as the primary means of oxygen ion conduction. The fuel cell-induced phase transition was observed from the insulating LST to a super OP2-P conductivity of 0.221 S·cmP-1P at 550 °C, leading to excellent current and power outputs

Conversion mechanism of NiCo2Se4 nanotube sphere anodes for potassium-ion batteries

Given the abundance of potassium resources, potassium-ion batteries are considered a low-cost alternative to lithium-ion types. However, their electrochemical performance remains rather unsatisfactory because potassium ions have sluggish kinetics and large ionic radius. In this study, NiCo2Se4 nanotube spheres are synthesized as efficient potassium storage hosts via a facile two-step hydrothermal process. The rationally designed electrode has various ameliorating morphological and functional features, including the following: (i) A hollow structure allows for relief of the volume expansion while offering an excellent electrochemical reactivity to accelerate the conversion kinetics; (ii) a high electrical conductivity for enhanced electron transfer; and (iii) myriad vacancies to supply active sites for electrochemical reactions. As such, the electrode delivers an initial reversible capacity of 458.1 mAh g−1 and retains 346.6 mAh g−1 after 300 cycles at 0.03 A g−1. The electrode sustains a high capacity of 101.4 mAh g−1 even at a high current density of 5 A g−1 and outperforms the majority of state-of-the-art anodes in terms of both cyclic capacity and rate capability, especially at above 1.0 A g−1. This study not only proves bimetallic selenides are promising candidates for potassium storage devices but also offers new insight into the rational design of electrode materials for high-rate potassium-ion batteries

Changes in Environmental Awareness and its Connection to Local Environmental Management in Water Conservation Zones: The Case of Beijing, China

This paper aims at investigating the change over time in the environmental awareness in rural Chinese communities and its correlation with environmental management measures implemented at the local level. We identify three main components of awareness, namely: perception, behavior, and attitude toward environmental management measures. Data were collected from two surveys in three villages in northern China in 2006 and 2015 that interviewed 125 and 129 respondents, respectively, and were analyzed employing an Analytic Hierarchy Process (AHP) approach. The results discussed in the paper show that environmental awareness increased between 2006–2015, and was mainly manifested in better environmental behavior and understanding of environmental status due an improvement in rural infrastructure and a greater amount of information provided to rural residents about the environment. Place of residence had a considerable influence on respondents’ environmental awareness: residents in eco-villages had a higher environmental awareness than those living in common agricultural villages. This appears to indicate a positive nexus between the comprehensiveness of environmental management measures implemented locally, and environmental awareness. Also, the universality of environment issues reduced the importance of socioeconomic and demographic factors in determining the degree of environmental awareness. However, more attention should be paid to villagers’ external behavior and inner feelings, such as their attitude to governmental management policies. These findings yield important policy implications that are relevant to the promotion of environmental awareness in China’s rural communities, and the adoption of more effective environmental management measures

The Qur'an and Identity in Contemporary Chinese Fiction

How is it possible to comprehend and assess the impact of the Qur’an on the literary expressions of Chinese Muslims (Hui) when the first full ‘translations’ of the Qur’an in Chinese made by non-Muslims from Japanese and English appeared only in 1927 and 1931, and by a Muslim from Arabic in 1932? But perhaps the fact that such a translation appeared so late in the history of the Muslim community in China, who have had a continuous presence since the ninth-century, is the best starting point. For it would be possible to address the relationship between the sacred text (as well as language) and identity among minority groups in a different way. This paper looks at the ways in which the Qur’an is imagined then embodied in literary texts authored by two prize-winning Chinese Muslim authors: Huo Da (b. 1945) and Zhang Chengzhi (b. 1948). While Huo Da, who does not have access to the Arabic language, alludes to the Chinese Qur’an in her novel, The Muslim’s Funeral (1982), transforming the its teachings into ritual performances of alterity through injecting Arabic and Persian words for religious rituals into her narrative of a Muslim family’s fortunes at the turn of the twentieth century, Zhang Chengzhi, who learned Arabic as an adult and travelled widely in the Muslim world, involves himself in reconstructing the history of the spread and persecution of the Jahriyya Sufi sect (an off-shoot of the Naqshabandiyya) in China between the seventeenth and nineteenth centuries in his only historical novel, A History of the Soul (1991), and in education reform in Muslim communities, inventing an identity for Chinese Muslims based on direct knowledge of the sacred text and tradition and informed by the history of Islam not in China alone but in the global Islamic world, especially Arabic Islamic history

Insights into dynamic covalent chemistry for bioconjugation applications

Dynamic covalent chemistry (DCC) is currently exploited in several areas of biomedical applications such as in drug discovery, sensing, molecular separation, catalysis etc. Hydrazone and oxime chemistry have several advantages, such as mild reaction conditions, selectivity, efficiency, and biocompatibility and therefore, have the potential to be for bioconjugation applications. However, these reactions suffer from major drawbacks of slow reaction rate and poor bond stability under physiological conditions. In this regard, the work presented in this thesis focuses on designing novel bioconjugation reactions amenable under physiological conditions with tunable reaction kinetics and conjugation stability. The first part of the thesis presents different strategies of dynamic covalent reactions utilized for biomedical applications. In the next part, a detailed study related to the mechanism and catalysis of oxime chemistry was investigated in the presence of various catalysts. Aniline, carboxylate and saline were selective as target catalysts and their reaction kinetics were compared under physiological conditions (Paper I and II). Then we attempted to explore the potential of those chemistries in fabricating 3D hydrogel scaffolds for regenerative medicine application. A novel mild and regioselective method was devised to introduce an aldehyde moiety onto glycosaminoglycans structure. This involved the introduction of amino glycerol to glycosaminoglycans, followed by regioselective oxidation of tailed flexible diol without affecting the C2-C3 diol groups on the disaccharide repeating unit. The oxidation rate of the tailed flexible diol was 4-times faster than that of C2-C3 diol groups of native glycosaminoglycan. This strategy preserves the structural integrity of the glycosaminoglycans and provides a functional aldehyde moiety (Paper III). Further, different types of hydrazones were designed and their hydrolytic stability under acidic condition was carefully evaluated. The hydrazone linkage with the highest hydrolytic stability was utilized in the preparation of extracellular matrix hydrogel for delivery of bone morphogenetic proteins 2 in bone regeneration (Paper IV) and studied for controlled release of the growth factor (Paper III). In summary, this thesis presents a selection of strategies for designing bioconjugation chemistries that possess tunable stability and reaction kinetics under physiological conditions. These chemistries are powerful tools for conjugation of biomolecules for the biomedical applications