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881.
Observation of Electrochemically Driven Elemental Segregation in a Si Alloy Thin‐Film Anode and its Effects on Cyclic Stability for Li‐Ion Batteries
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Minsub Oh Sekwon Na Chang‐Su Woo Jun‐Ho Jeong Sung‐Soo Kim Alicja Bachmatiuk Mark Hermann Rümmeli Seungmin Hyun Hoo‐Jeong Lee 《Liver Transplantation》2015,5(22)
The results of employing (Ti, Fe)‐alloyed Si thin‐film anode for Li‐ion batteries are reported. The material demonstrates an impressive cyclic stability with stable operation for more than 500 cycles at a capacity higher than 1400 mAh g?1. Materials characterization using scanning electron microscopy and transmission electron microscopy illuminates an intriguing materials process behind the performance: ripple‐like pattern formation via electrochemically driven segregation of the inactive elements (Ti and Fe). The ripple structure plays a buffer role by suppressing loss of the active material upon further cycling, allowing the anode to gradually transform into an array of microbumps. The morphological evolution helps the anode endure long cycles (even up to 1000 cycles) without catastrophic failure as the bumps shrank slowly and steadily, consistent with the electrochemical data. 相似文献
882.
Symplasmic short- and long-distance communication may be regulated at different levels of plant body organization. It depends on cell-to-cell transport modulated by plasmodesmata conductivity and frequency but above all on morphogenetic fields that integrate a plant at the supracellular level. Their control of physiological and developmental processes is especially important in trees, where the continuum consists of 3-dimensional systems of: 1) stem cells in cambium, and 2) living parenchyma cells in the secondary conductive tissues. We found that long-distance symplasmic transport in trees is spatially regulated. Uneven distribution of fluorescent tracer in cambial cells along the branches examined illustrates an unknown intrinsic phenomenon that can possibly be important for plant organism integration. Here we illustrate the spatial dynamics of symplasmic transport in cambium, test and exclude the role of callose in its regulation, and discuss the mechanism that could possibly be responsible for the maintenance of this spatial pattern. 相似文献
883.
The effect of exogenously applied natural [indole-3-acetic acid (IAA), phenylacetic acid (PAA), indole-3-butyric acid (IBA)] and synthetic [1-naphthaleneacetic acid (NAA)] auxins on the growth and metabolism of green microalga Chlorella vulgaris was examined. Exogenous auxins acted in a concentration-dependent manner on algal growth. Phytohormones at concentration of 100 μM inhibited algal growth expressed as the number of cells. IAA and IBA displayed the highest biological activity at 0.1 μM, whereas PAA and NAA were characterized by the greatest stimulatory effect on the number of cells at 1 μM. Treatment with IAA and IBA at 0.1 μM or NAA and PAA at 1 μM increased the concentration of photosynthetic pigments, monosaccharides and soluble proteins in C. vulgaris. Moreover, all auxins stimulated enzymatic (ascorbate peroxidase, catalase, superoxide dismutase) and non-enzymatic antioxidant (ascorbate, glutathione) systems in C. vulgaris, and therefore, suppressed lipid peroxidation and hydrogen peroxide accumulation. The data supports the hypothesis that auxins play a central role in the regulation of C. vulgaris growth and metabolism and the components of cellular redox systems that are thought to have a prominent role in the regulation of auxin-dependent processes. 相似文献
884.
Alicja Puchta Avee Naidoo Chris P. Verschoor Dessi Loukov Netusha Thevaranjan Talveer S. Mandur Phuong-son Nguyen Manel Jordana Mark Loeb Zhou Xing Lester Kobzik Maggie J. Larché Dawn M. E. Bowdish 《PLoS pathogens》2016,12(1)
Monocyte phenotype and output changes with age, but why this occurs and how it impacts anti-bacterial immunity are not clear. We found that, in both humans and mice, circulating monocyte phenotype and function was altered with age due to increasing levels of TNF in the circulation that occur as part of the aging process. Ly6C+ monocytes from old (18–22 mo) mice and CD14+CD16+ intermediate/inflammatory monocytes from older adults also contributed to this “age-associated inflammation” as they produced more of the inflammatory cytokines IL6 and TNF in the steady state and when stimulated with bacterial products. Using an aged mouse model of pneumococcal colonization we found that chronic exposure to TNF with age altered the maturity of circulating monocytes, as measured by F4/80 expression, and this decrease in monocyte maturation was directly linked to susceptibility to infection. Ly6C+ monocytes from old mice had higher levels of CCR2 expression, which promoted premature egress from the bone marrow when challenged with Streptococcus pneumoniae. Although Ly6C+ monocyte recruitment and TNF levels in the blood and nasopharnyx were higher in old mice during S. pneumoniae colonization, bacterial clearance was impaired. Counterintuitively, elevated TNF and excessive monocyte recruitment in old mice contributed to impaired anti-pneumococcal immunity since bacterial clearance was improved upon pharmacological reduction of TNF or Ly6C+ monocytes, which were the major producers of TNF. Thus, with age TNF impairs inflammatory monocyte development, function and promotes premature egress, which contribute to systemic inflammation and is ultimately detrimental to anti-pneumococcal immunity. 相似文献
885.
L. I. Mukhametova D. A. Gulin P. V. Binevski R. B. Aisina O. A. Kost I. I. Nikolskaya 《Russian Journal of Bioorganic Chemistry》2008,34(4):421-427
The effects of hypotensive agents (captopril, enalaprilat, and lisinopril) on the activities of components of the fibrinolytic system (FS) and the effects of antifibrinolytic agents (6-aminohexanoic acid (6-AHA) and tranexamic acid (t-AMCHA)) on the activities of angiotensin converting enzyme (ACE) were studied in vitro. Enalaprilat did not affect the FS activity. Captopril considerably inhibited the amidase activities of urokinase (u-PA), tissue plasminogen activator (t-PA), and plasmin ([I]50 (2.0?2.6) ± 0.1 mM), and the activation of Glu-plasminogen by t-PA and u-PA ([I]50 (1.50?1.80) ± 0.06 mM), which may be due to the presence of a mercapto group in the inhibitor molecule. Lisinopril did not affect the amidase activities of FS enzymes, but stimulated Glu-plasminogen activation by u-PA and inhibited activation fibrin-bound Glu-plasminogen by t-PA ([I]50 (12.0 ± 0.5) mM). Presumably, these effects can be explained by the presence in lisinopril of a Lys side residue, whose binding to lysine-binding Glu-plasminogen centers resulted, on the one hand, in the transformation from its closed conformation to a semi-open one and, on the other hand, in its desorption from fibrin. Unspecific inhibition of the activity of ACE, a key enzyme of the renin-angiotensin system, in the presence of 6-AHA and t-AMCHA ([I]50 10.0 ± 0.5 and 7.5 ± 0.4 mM, respectively) was found. A decrease in the ACE activity along with the growth of the fibrin monomer concentration was revealed. The data demonstrate that, along with endogenous mediated interaction between FS and RAS, relations based on the direct interactions of exogenous inhibitors of one system affecting the activities of components of another system can take place. 相似文献
886.
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888.
Tomasz Gortat Alicja Gryczyńska-Siemiątkowska Robert Rutkowski Anna Kozakiewicz Antoni Mikoszewski Michał Kozakiewicz 《Acta theriologica》2010,55(2):109-121
Reduced connectivity among local populations inhabiting a spatially heterogeneous landscape may restrict gene flow and thus
contribute to diminished genetic variation within a population. The aim of this study was to determine the role of geographic
distance and habitat barriers in developing genetic structure of a yellow-necked mouse Apodemus flavicollis (Melchior, 1834) population, taking into consideration the spatial organization of the landscape. A field study was carried
out in two plots located in NE Poland that differed considerably in terms of the scale of habitat fragmentation: (1) a continuous
forest complex, and (2) a mosaic of smaller forest habitats. The plots were separated by a water barrier comprised of a chain
of lakes. DNA samples from a total of 654 individuals were examined by microsatellite analysis (5 loci). The results showed
that the yellow-necked mouse population was characterized by a poorly pronounced genetic structure throughout the study area,
although the statistical significance of F
ST for most location pairs indicated that gene flow in the area was not free. The division of the mouse population into three
genetically distinct groups clearly demonstrated the significant role of water bodies as a natural barrier effectively hindering
free movement of animals and thus gene flow. Analysis of the genetic structure of the mouse population throughout the study
area and also within the distinguished groups indicated that the entire study population may be considered as a single metapopulation.
Our results suggest that geographic distance alone is not the predominant factor affecting the genetic structure of population,
but in the mosaic landscape the relative isolation of individual forest fragments, and barriers hindering movements of individuals
and limiting gene flow among local populations played a much more important role. 相似文献
889.
The present study was aimed to determine the effect of GnRH analog (buserelin acetate) on the quality of bovine spermatozoa stored at 16°?C for 24?h. Semen collected in the summer season from June to September from healthy Polish Holstein–Friesian bulls. Ejaculates were centrifuged, divided and diluted to the final concentration of 240?×?106 spermatozoa/mL using animal protein–free commercial BIOXcell® extender (IMV Technologies, L’aigle, France) (Control) or with BIOXcell® extender supplemented with buserelin acetate and stored 0, 8 and 24?h. Sperm motility parameters analysis was performed using a computer-assisted sperm analysis (CASA) system. The viability of spermatozoa was performed using flow cytometer. The addition of buserelin acetate to BIOXcell® extender did positively affect the total motility (was higher in the observed samples with the addition of 2?µg/mL and 4?µg/mL than in the control group), progressive motile (forward progressing sperm was significantly increased (p?<?0.05) over the control group at the 0?h and 8?h of incubation following the supplementation of 2, 4 and 8?μg/mL buserelin acetate) and viability of spermatozoa (the number of live spermatozoa was significantly higher (p?<?0.05) in 2?µg/mL and 4?µg/mL samples with buserelin acetate at 8th hour of incubation and in sample with 4?µg/mL at 24th hour of incubation compared to the control group). We recommend adding 4?µg/mL to the extender to improve the quality of bovine semen. 相似文献
890.