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1.
The Na‐ion battery is recognized as a possible alternative to the Li‐ion battery for applications where power and cost override energy density performance. However, the increasing instability of their electrolyte with temperature is still problematic. Thus, a central question remains how to design Na‐based electrolytes. Here, the discovery of a Na‐based electrolyte formulation is reported which enlists four additives (vinylene carbonate, succinonitrile, 1,3‐propane sultone, and sodium difluoro(oxalate)borate) in proper quantities that synergistically combine their positive attributes to enable a stable solid electrolyte interphase at both negative and positive electrodes surface at 55 °C. Moreover, the role of each additive that consists in producing specific NaF coatings, thin elastomers, sulfate‐based deposits, and so on via combined impedance and X‐ray photoelectron spectroscopy is rationalized. It is demonstrated that empirical electrolyte design rules previously established for Li‐ion technology together with theoretical guidance is vital in the quest for better Na‐based electrolytes that can be extended to other chemistries. Overall, this finding, which is implemented to 18 650 cells, widens the route to the rapid development of the Na‐ion technology based on Na3V2(PO4)2F3/C chemistry.  相似文献   
2.
Chickens of Regional Poultry Research Laboratory (RPRL) inbred line 63 regress sarcomas induced by Bryan high-titer Rous sarcoma virus to a greater extent than chickens of line RPRL 100, although these lines are identical for the major histocompatibility B complex. They differ, however, at three independent autosomal loci: Ly-4 and Th-1 determine the surface alloantigens of partly overlapping subsets of T lymphocytes, and Bu-1 determines a surface alloantigen of B lymphocytes. The association of genotypes at these loci with quantitative variation in their ability to regress Rous sarcomas was tested in segregating F4 generation progeny derived from crosses of lines 100 and 63. The Ly-4 and Bu-1 genotypes showed association with Rous sarcoma regression, but the Th-1 genotype did not. Chickens of the Ly-4 a/Ly-4 a, Bu-1 b/Bu-1 b and Ly-4 b/Ly-4 b, Bu-1 a/Bu-1 a genotypes had a significantly higher regressor ability than the other two double homozygous genotypes. These results indicate that higher regression is associated with (1) interaction between the Ly-4 and Bu-1 loci, and (2) complementation between either the line 6 Ly-4 a allele and the line 100 Bu-1 b allele, or the line 100 Ly-4 b allele and the line 6 Bu-1 a allele.  相似文献   
3.
4.
Summary Resistance to watermelon mosaic virus-2 in Phaseolus vulgaris L. is conferred by two distinct dominant alleles at independent loci. Based on segregation data one locus is designated Wmv, the other, Hsw. The dominant allele Wmv from cv. Great Northern 1140 prevents systemic spread of the virus but viral replication occurs in inoculated tissue. In contrast, Hsw confers both local and systemic resistance to WMV-2 below 30C. At higher temperatures, plants that carry this allele in the absence of modifying or epistatic factors develop systemic veinal necrosis upon inoculation with the virus that results in rapid death. Patho-type specificity has not been demonstrated for either allele; both factors confer resistance to every isolate tested. A temperature-sensitive shift in epistasis is apparent between dominant alleles at these loci. Because Hsw is very tightly linked if not identical to the following genes for hypersensitivity to potyviruses I, (bean common mosaic virus), Bcm, (blackeye cowpea mosaic virus), Cam, (cowpea aphid-borne mosaic virus) and Hss (soybean mosaic virus), parental, reciprocal dihybrid F1 populations, and selected F3 families were inoculated with each of these viruses and held at 35 C. F1 populations developed vascular necrosis completely or primarily limited to inoculated tissue, while F3 families from WMV-2-susceptible segregates were uniformly susceptible to these viruses. The relationship between Hsw, Wmv and other genes for potyvirus resistance suggest patterns in the evolution of resistance and viral pathogenicity. Characterization of the resistance spectrum associated with each factor provides an additional criterion to distinguish genes for plant virus resistance.  相似文献   
5.
The human alpha satellite repetitive DNA family is organized as distinct chromosome-specific subsets localized to the centromeric region of each chromosome. Here, we report he isolation and characterization of cloned repeat units which define a hierarchical subset of alpha satellite on human chromosome 1. This subset is characterized by a 1.9-kb higher-order repeat unit which consists of 11 tandem approximately 171-bp alpha satellite monomer repeat units. The higher-order repeat unit is itself tandemly repeated, present in at least 100 copies at the centromeric region of chromosome 1. Using pulsed-field gel electrophoresis we estimate the total array length of these tandem sequences at the centromere of chromosome 1 to be several hundred kilobase pairs. Under conditions of high stringency, the higher-order repeat probe hybridizes specifically to chromosome 1 and can be used to detect several associated restriction fragment length DNA polymorphisms. As such, this probe may be useful for molecular and genetic analyses of the centromeric region of human chromosome 1.  相似文献   
6.
Organization and evolution of alpha satellite DNA from human chromosome 11   总被引:9,自引:0,他引:9  
The human alpha satellite repetitive DNA family is organized as distinct chromosomal subsets located at the centromeric regions of each human chromosome. Here, we describe a subset of the alpha satellite which is localized to human chromosome 11. The principal unit of repetition of this alpha satellite subset is an 850 bp XbaI fragment composed of five tandem diverged alphoid monomers, each 171 bp in length. The pentamer repeat units are themselves tandemly reiterated, present in 500 copies per chromosome 11. In filter hybridization experiments, the Alpha 11 probes are specific for the centromeric alpha satellite sequences of human chromosome 11. The complete nucleotide sequences of two independent copies of the XbaI pentamer reveal a pentameric configuration shared with the alphoid repeats of chromosomes 17 and X, consistent with the existence of an ancestral pentameric repeat common to the centromeric arrays of at least these three human chromosomes.  相似文献   
7.
Previous genetic analyses of chromosome 17 markers and NF1 (Fain et al. 1987) were extended in an attempt to order marker loci that map physically to 17cen----17q12. Three additional markers (HHH202, CRI-L581, and CRI-L946) were included in the analyses. Recombinants within the cluster of seven unordered marker loci were identified by pairwise analyses for each family and by examining the within-sibship segregation patterns for different markers. Changes in the segregation pattern for different loci define genetic breakpoints. Given that interference is complete in the region, markers with the same segregation pattern lie on one side of the breakpoint, while markers with different segregation patterns lie on opposite sides of the breakpoint. If the order of boundary markers is known, markers on each side of a breakpoint can be oriented in relation to the centromere. The order cen-(HHH202/NF1)-(EW207)-(EW203/CRI-L581)- (CRI-L946)-(HOX-2/NGFR)-qter was inferred by combining information from physical breakpoints in a panel of mouse/human hybrids and information from genetic breakpoints found in 16 NF1 families.  相似文献   
8.
A cDNA for rat liver beta-glucuronidase was isolated, its sequence determined and its expression after transfection into COS cells studied. The deduced amino acid sequence of the rat liver clone showed 77% homology with that from the cDNA for human placental beta-glucuronidase and 47% homology with that deduced from the cDNA for Escherichia coli beta-glucuronidase. Several differences were found between the cDNA from rat liver and that previously reported from rat preputial gland. Only one change leads to an amino acid difference in the mature enzyme. A chimeric clone was constructed by using a fragment encoding the first 18 amino acid residues of the signal sequence from the human placental cDNA clone and a fragment from the rat clone encoding four amino acid residues of the signal sequence, all 626 amino acid residues of the mature rat enzyme, and all of the 3' untranslated region. After transfection into COS cells the chimeric clone expressed beta-glucuronidase activity that was specifically immunoprecipitated by antibody to rat beta-glucuronidase. The Mr value of 76,000 of the expressed gene product was characteristic of the glycosylated rat enzyme. It was proteolytically processed in COS cells to Mr 75,000 6 h after metabolic labelling. At least 50% of the expressed enzyme was secreted at 60 h post-transfection, but the secreted enzyme did not undergo proteolytic processing. These results provide evidence that the partial cDNA isolated from a rat liver library contains the complete coding sequence for the mature rat liver enzyme and that the chimeric signal sequence allows normal biosynthesis and processing of the transfected rat liver enzyme in COS cells.  相似文献   
9.
T Haaf  H F Willard 《Genomics》1992,13(1):122-128
The general usefulness of alpha-satellite DNA probes for the molecular, genetic, and cytogenetic analysis of the human genome is enhanced by their being chromosome specific. Here, we describe the isolation and characterization of an alpha-satellite subset specific for human chromosome 2. Three clones, p2-7, p2-8, and p2-11, obtained from an EcoRI-digested lambda phage library from flow-sorted chromosome 2, are specific for the centromere of chromosome 2 by somatic cell hybrid mapping and chromosomal in situ hybridization. Nucleotide sequence analysis identifies the chromosome 2-specific alpha-satellite subset D2Z1 as a member of the suprachromosomal subfamily II, which is based on a characteristic two-monomer repeat. The D2Z1 subset is further organized as a series of diverged 680-bp tetramers, revealed after digestion of genomic DNA with HaeIII, HindIII, HinfI, StuI, and XbaI. Using pulsed-field gel electrophoresis (PFGE), probes p2-7, p2-8, and p2-11 detect polymorphic restriction patterns within the alpha-satellite array. Among 15 different chromosomes 2 (in two two-generation families and one three-generation family), the length of the D2Z1 alpha-satellite array varied between 1050 and 2900 kb (mean = 1850 kb, SD = 550 kb). The inheritance of the chromosome 2 alpha-satellite arrays and their associated polymorphisms was strictly Mendelian.  相似文献   
10.
The centromeric regions of human chromosomes contain long tracts of tandemly repeated DNA, of which the most extensively characterized is alpha satellite. In a screen for additional centromeric DNA sequences, four phage clones were obtained which contain alpha satellite as well as other sequences not usually found associated with tandemly repeated alpha satellite DNA, including L1 repetitive elements, an Alu element, and a novel AT-rich repeated sequence. The alpha satellite DNA contained within these clones does not demonstrate the higher-order repeat structure typical of tandemly repeated alpha satellite. Two of the clones contain inversions; instead of the usual head-to-tail arrangement of alpha satellite monomers, the direction of the monomers changes partway through each clone. The presence of both inversions was confirmed in human genomic DNA by polymerase chain reaction amplification of the inverted regions. One phage clone contains a junction between alpha satellite DNA and a novel low-copy repeated sequence. The junction between the two types of DNA is abrupt and the junction sequence is characterized by the presence of runs of A's and T's, yielding an overall base composition of 65% AT with local areas > 80% AT. The AT-rich sequence is found in multiple copies on chromosome 7 and homologous sequences are found in (peri)centromeric locations on other human chromosomes, including chromosomes 1, 2, and 16. As such, the AT-rich sequence adjacent to alpha satellite DNA provides a tool for the further study of the DNA from this region of the chromosome. The phage clones examined are located within the same 3.3-Mb SstII restriction fragment on chromosome 7 as the two previously described alpha satellite arrays, D7Z1 and D7Z2. These new clones demonstrate that centromeric repetitive DNA, at least on chromosome 7, may be more heterogeneous in composition and organization than had previously been thought.  相似文献   
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