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151.
Hanyu Huo Yue Chen Jing Luo Xiaofei Yang Xiangxin Guo Xueliang Sun 《Liver Transplantation》2019,9(17)
Solid polymer electrolytes as one of the promising solid‐state electrolytes have received extensive attention due to their excellent flexibility. However, the issues of lithium (Li) dendrite growth still hinder their practical applications in solid‐state batteries (SSBs). Herein, composite electrolytes from “ceramic‐in‐polymer” (CIP) to “polymer‐in‐ceramic” (PIC) with different sizes of garnet particles are investigated for their effectiveness in dendrite suppression. While the CIP electrolyte with 20 vol% 200 nm Li6.4La3Zr1.4Ta0.6O12 (LLZTO) particles (CIP‐200 nm) exhibits the highest ionic conductivity of 1.6 × 10?4 S cm?1 at 30 °C and excellent flexibility, the PIC electrolyte with 80 vol% 5 µm LLZTO (PIC‐5 µm) shows the highest tensile strength of 12.7 MPa. A sandwich‐type composite electrolyte (SCE) with hierarchical garnet particles (a PIC‐5 µm interlayer sandwiched between two CIP‐200 nm thin layers) is constructed to simultaneously achieve dendrite suppression and excellent interfacial contact with Li metal. The SCE enables highly stable Li plating/stripping cycling for over 400 h at 0.2 mA cm?2 at 30 °C. The LiFePO4/SCE/Li cells also demonstrate excellent cycle performance at room temperature. Fabricating sandwich‐type composite electrolytes with hierarchical filler designs can be an effective strategy to achieve dendrite‐free SSBs with high performance and high safety at room temperature. 相似文献
152.
Direct ethanol fuel cells (DEFCs) have great activity as a green energy conversion device. However, the weak activity of most anode electrocatalysts for the C? C bond cleavage is an obstacle to the DEFCs development. Herein, a simple galvanic replacement reaction strategy to synthesize hollow and porous PtRhCu trimetallic nanoboxes (CNBs) with a tunable Pt/Rh atomic ratio is developed. For the ethanol oxidation reaction (EOR), PtRhCu CNBs show morphology and composition‐dependent electrocatalytic activity. The composition optimized Pt54Rh4Cu42 CNBs exhibit excellent specific and mass activity and stability for the EOR, which is attributed to its unique geometric structure and synergistic effects. The hollow porous structure can effectively enhance the atomic utilization and mass transfer. The introduction of Cu improves the antipoisoning capability for CO. The introduction of Rh elevates the self‐stability of PtRhCu CNBs. More importantly, further electrochemical results confirm that the introduction of Rh significantly promotes the cleavage of C? C bonds, leading to the transformation of the main catalytic pathway for EOR from C2 to C1 pathway. The real concentration detection for C2 products (CH3COOH and CH3CHO) shows Pt54Rh4Cu42 CNBs have a nearly 11.5‐fold C1 pathway enhancement compared to Pt nanoparticles, showing an obvious selectivity enhancement for the C1 pathway. 相似文献
153.
Lysosomal degradation of membrane lipids 总被引:1,自引:0,他引:1
Thomas Kolter 《FEBS letters》2010,584(9):1700-6422
The constitutive degradation of membrane components takes place in the acidic compartments of a cell, the endosomes and lysosomes. Sites of lipid degradation are intralysosomal membranes that are formed in endosomes, where the lipid composition is adjusted for degradation. Cholesterol is sorted out of the inner membranes, their content in bis(monoacylglycero)phosphate increases, and, most likely, sphingomyelin is degraded to ceramide. Together with endosomal and lysosomal lipid-binding proteins, the Niemann-Pick disease, type C2-protein, the GM2-activator, and the saposins sap-A, -B, -C, and -D, a suitable membrane lipid composition is required for degradation of complex lipids by hydrolytic enzymes. 相似文献
154.
Lectins, the divalent or polyvalent (glyco) proteins of non-immune origin of the cells agglutinate cells or other materials,
that display more than one saccharide of sufficient complementarity. Lectins considered ‘identical’ in terms of mono-and disaccharide
specificity can be differentiated by their ability to recognise the fine differences in more complex structures. The present
review discusses the interaction of lectins with various oligosaccharides and their resultant separations due to structural
variations. 相似文献
155.
Ontogenetic plasticity of anatomical and ecophysiological traits and their correlations in Iris pumila plants grown in contrasting light conditions 下载免费PDF全文
Stevan Avramov Danijela Miljković Nataša Barišić Klisarić Uroš Živković Aleksej Tarasjev 《Plant Species Biology》2017,32(4):392-402
To better understand what directs and limits the evolution of phenotype, constraints in the realization of the optimal phenotype need to be addressed. That includes estimations of variability of adaptively important traits as well as their correlation structures, but also evaluation of how they are affected by relevant environmental conditions and development phases. The aims of this study were to analyze phenotypic plasticity, genetic variability and correlation structures of important Iris pumila leaf traits in different light environments and ontogenetic phases, and estimate its evolutionary potential. Stomatal density, specific leaf area, total chlorophyll concentration and chlorophyll a/b ratio were analyzed on I. pumila full‐sib families in the seedling phase and on the same plants after 3 years of growth in contrasting light conditions typical for ontogenetic stage in question. There was a significant phenotypic plasticity in both ontogenetic stages, but significant genetic variability was detected only for chlorophyll concentrations. Correlations of the same trait between different stages were weak due to changes in environmental conditions and difference in ontogenetic reaction norms of different genotypes. Ontogenetic variability of correlation structures was detected, where correlations and integration were higher in seedlings compared with adult plants 3 years later. Correlations were affected by environmental conditions, with integration being higher in the lower light conditions, but correlations between phases being stronger in the higher light treatment. These findings demonstrated that the analyzed traits can be selected and can mostly evolve independently in different environments and ontogenetic stages, with low genetic variability as a potentially main constraint. 相似文献
156.
Structural differences between the repertoires of mouse and human germline genes and their evolutionary implications 总被引:1,自引:0,他引:1
J. C. Almagro Ismael Hernández Maria Carmen Ramírez Enrique Vargas-Madrazo 《Immunogenetics》1998,47(5):355-363
Although human and mouse antibodies are similar when one considers their diversification strategies, they differ in the extent
to which kappa and lambda light chains are present in their respective variable light chain repertoires. While the Igk-V germline genes are preponderant in mice (95% or more), they comprise only 60% in humans. This may account for differences
in the structural repertoire encoded in the Igk-V germline genes of these species. However, this subject has not been properly investigated, partially because a systematic
structural characterization of the mouse Igk-V germline genes has not been undertaken. In the present study we compiled all available information on mouse Igk-V germline genes to characterize their structural repertoire. As expected, comparison with the structural repertoire of human
Igk-V germline genes indicates differences. The most interesting is that the mouse Igk-V germline gene repertoire is more diverse in structural terms than its human counterpart: the mouse encodes seven canonical
structure classes (combination of canonical structures in L1 and L3). In contrast, the human encodes only four. Analysis of
the evolutionary relationships of human and mouse Igk-V germline genes led us to propose that the difference reflects a strategy of mice to compensate for the small lambda chain
contribution to the repertoire of their variable light chains.
Received: 1 June 1997 / Revised: 6 October 1997 相似文献
157.
Harry Adams Neil A. Bailey Philippe Bertrand Simon R. Collinson David E. Fenton Simon J. Kitchen 《Inorganica chimica acta》1996,250(1-2):139-148
The cyclocondensation of 2,5-diformylthiophene and the amines N,N-bis-(2-aminoethyl)-2-phenylethylamine, N,N-bis-(2aminoethyl)-t-butyl-amine and N,N-bis-(2-aminoethyl)-t-butyl-amine in the presence of silver(I) salts yields homodinuclear bibracchial tetraimine Schiff base macrocyclic complexes. The structures of two such complexes are also reported. The complex Ag2L4(NO3)(PF6) (2) crystallises in the triclinic space group
, No. 2) and has unit-cell dimensions a = 12.834(6), B = 13.183(6), C = 14.588(7) Å, = 64.86(4), β = 79.77(4), γ = 69.44(3)° with Z = 2; there is a monodentate and singly bridging nitrate anion present and the Ag---Ag separation is 4.161 Å. The complex Ag2L4(CH3CN)2(BF4)2·CH3CN (9) crystallises in the triclinic space group
, No. 2) and has unit-cell dimensions a = 9.297(4), B = 12.985(3), C = 21.770(5) Å, = 91.570(10), β = 92.33(3), γ = 97.92(3) ° with Z = 2; there is a strongly bonded acetonitrile molecule coordinated to each silver atom and the Ag---Ag separation is 4.920 Å. 相似文献
158.
Complete sequence determination of the brachiopod Lingula anatina mtDNA (28,818 bp) revealed an organization that is remarkably atypical for an animal mt-genome. In addition to the usual set of 37 animal mitochondrial genes, which make up only 57% (16,555 bp) of the entire sequence, the genome contains lengthy unassigned sequences. All the genes are encoded in the same DNA strand, generally in a compact way, whereas the overall gene order is highly divergent in comparison with known animal mtDNA. Individual genes are generally longer and deviate considerably in sequence from their homologues in other animals. The genome contains two major repeat regions, in which 11 units of unassigned sequences and six genes (atp8, trnM, trnQ, trnV, and part of cox2 and nad2) are found in repetition, in the form of nested direct repeats of unparalleled complexity. One of the repeat regions contains unassigned repeat units dispersed among several unique sequences, novel repetitive structure for animal mtDNAs. Each of those unique sequences contains an open reading frame for a polypeptide between 80 and 357 amino acids long, potentially encoding a functional molecule, but none of them has been identified with known proteins. In both repeat regions, tRNA genes or tRNA gene-like sequences flank major repeated units, supporting the view that those structures play a role in the mitochondrial gene rearrangements. Although the intricate repeated organization of this genome can be explained by recurrent tandem duplications and subsequent deletions mediated by replication errors, other mechanisms, such as nonhomologous recombinations, appear to explain certain structures more easily. 相似文献
159.
Chihiro Kachi-TerajimaHitoshi Miyasaka Tomohiko IshiiKen-ichi Sugiura Masahiro Yamashita 《Inorganica chimica acta》2002,332(1):210-215
The ligand substitution reaction of Ru2(O2CCH3)4Cl with 2-amino-4,6-dimethylpyrimidine (Hadmpym) under gentle refluxing conditions in methanol led to the formation of a bridging-ligand mono-substituted compound, [Ru2(O2CCH3)3(admpym)(Cl)(MeOH)] (1). Compound 1 crystallized in monoclinic space group P21/n (no. 14) with a=8.3074(8) Å, b=12.3722(8) Å, c=18.913(1) Å, β=95.559(3)°, V=1934.8(3) Å3, and Z=4. Temperature dependence of the magnetic susceptibility of 1 revealed it to be in a spin ground state S=3/2 arising from the electronic configuration of σ2π4δ2(δ*π*)3. Compound 1 undergoes three metal-centered redox reactions in electrochemistry: E1/2 (ox)=+0.72 V (Ia/Ic<1, ΔEp=0.17 V); E1/2 (1,red)=−0.65 V (Ia/Ic≈1, ΔEp=0.10 V); and E1/2 (2,red)=−1.80 V (Ia/Ic?1, ΔEp=0.16 V). Then, the redox species produced by electrolysis were characterized by spectroscopic studies. 相似文献
160.
M. Michael Gromiha Motohisa Oobatake Hidetoshi Kono Hatsuho Uedaira Akinori Sarai 《Journal of Protein Chemistry》1999,18(5):565-578
In order to understand the mechanism of protein stability and to develop a simple method for predicting mutation-induced stability changes, we analyzed the relationship between stability changes caused by buried mutations and changes in 48 amino acid properties. As expected from the importance of hydrophobicity, properties reflecting hydrophobicity are strongly correlated with the stability of proteins. We found that subgroup classification based on secondary structure increased correlations significantly, and mutations within -strand segments correlated better than did those in -helical segments, which may result from stronger hydrophobicity of the -strands. Multiple regression analyses incorporating combinations of three properties from among all possible combinations of the 48 properties increased the correlation coefficient to 0.88 and by an average of 13% for all data sets. Analyzing the stability of tryptophan synthase mutants with Glu49 replaced by all other residues except Arg revealed that combining buriedness, solvent-accessible surface area for denatured protein, and unfolding Gibbs free energy change increased the correlation to 0.95. Consideration of sequence and structural information (neighboring residues in sequence and in space) did not significantly strengthen the correlations in buried mutations, suggesting that nonspecific interactions dominate in the interior of proteins. 相似文献