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81.
82.
The lactose-protease plasmid pUCL22 of Lactococcus lactis subsp. lactis strain CNRZ270 contained two inverted copies of IS 1076 flanking a region of 3.7 kb. This internal region was sequenced and found to contain two large open reading frames, ORF1 and ORFP in opposite orientations. ORF1 consists of 2289 bp; the deduced 763-amino-acid sequence is similar to the ATPases of the ClpA family. It contains two well-conserved consensus ATP-binding sites. It was named ClpL. ORFP consists of 930 bp encoding a protein of 310 amino acids. No similarity with any known protein was found in GenBank data for ORFP. Increased ATP-dependent proteolytic activity was detected in extracts from Escherichia coli cells expressing the clpL and ORFP genes.  相似文献   
83.
Summary Leaf and bark structure of a birch clone (Betula pendula Roth) continuously exposed to charcoal-filtered air or charcoal-filtered air plus ozone (0.05, 0.075, 0.1 l 1-1) was investigated throughout one growing season. Increasing ozone dose influenced leaf differentiation by reducing leaf area and increasing inner leaf air space, density of cells developing into stomata, scales and hairs. When approximately the same ozone dose had been reached, macroscopical and microscopical symptoms appeared irrespective of the ozone concentration used during treatment. Structural decline began in mesophyll cells around stomatal cavities (droplet-like exudates on the cell walls), continued with disintegration of the cytoplasma and ended in cell collapse. Epidermal cells showed shrinkage of the mucilaginous layer (related to water loss). Their collapse marked the final stage of leaf decline. When subsidiary cells collapsed, guard cells passively opened for a transitory period before collapsing and closing. With increasing ozone dose starch remained accumulated along the small leaf veins and in guard cells. IIK-positive grains were formed in the epidermal cells. This contrasted with the senescent leaves, where starch was entirely retranslocated. Injury symptoms in stem and petiole proceeded from the epidermis to the cambium. Reduced tissue area indicated reduced cambial activity. In plants grown in filtered air and transferred into ozone on 20 August, injury symptoms developed faster than in leaves formed in the presence of ozone. Results are discussed with regard to O3-caused acclimation and injury mechanisms.  相似文献   
84.
pUCL22 is the lactose protease plasmid of Lactococcus lactis ssp. lactis CNRZ270. The nucleotide sequence of its replication region Rep22 contains a non-transcribed region, the replication origin, followed by a gene encoding a putative 388-amino-acid protein named Rep22A. The promoter regions of the rep22A and pC194 cat genes share strong similarities and the pUCL22 replicon exerted trans or cis negative control on the pC194 cat gene expression in L. lactis. We suggest that Rep22A binds to its own promoter as well as to the pC194 cat promoter and thus is autoregulated. We show that pUCL22 replicates mainly by a bidirectional theta mechanism in L. lactis, and is representative of a widely distributed replicon family, members of which could be co-resident. We propose that compatibility between these closely related replicons results from minor replication protein modifications coupled with base changes in their respective binding sites, supporting the co-existence of numerous related replicons in lactococcal strains.  相似文献   
85.
The garnet-type phase Li7La3Zr2O12 (LLZO) attracts significant attention as an oxide solid electrolyte to enable safe and robust solid-state batteries (SSBs) with potentially high energy density. However, while significant progress has been made in demonstrating compatibility with Li metal, integrating LLZO into composite cathodes remains a challenge. The current perspective focuses on the critical issues that need to be addressed to achieve the ultimate goal of an all-solid-state LLZO-based battery that delivers safety, durability, and pack-level performance characteristics that are unobtainable with state-of-the-art Li-ion batteries. This perspective complements existing reviews of solid/solid interfaces with more emphasis on understanding numerous homo- and heteroionic interfaces in a pure oxide-based SSB and the various phenomena that accompany the evolution of the chemical, electrochemical, structural, morphological, and mechanical properties of those interfaces during processing and operation. Finally, the insights gained from a comprehensive literature survey of LLZO–cathode interfaces are used to guide efforts for the development of LLZO-based SSBs.  相似文献   
86.
We tested the hypothesis that IL-6 release from muscle during exercise may be related to muscle activity of 5'-AMP-activated protein kinase (AMPK). Eight healthy, well-trained young men completed two 60-min trials on a bicycle ergometer at 70% of their peak oxygen uptake in either a glycogen-depleted or a glycogen-loaded state. IL-6 was released from the leg already after 10 min of exercise in the glycogen-depleted state, whereas no significant release was observed at any time in the loaded state. Nevertheless, plasma IL-6 increased similarly in the two trials from approximately 0.8 pg/ml at rest to approximately 4.5 pg/ml after 60 min of exercise. Activity of alpha1-AMPK (160%) and alpha2-AMPK (145%) was increased at rest in the glycogen-depleted compared with the loaded situation. During exercise, alpha1-AMPK activity did not change from resting levels in both trials, whereas alpha2-AMPK activity increased only in the glycogen-depleted state. After 60 min of exercise in the glycogen-depleted state, individual values of alpha2-AMPK activity correlated significantly (r = 0.87, P < 0.006) with individual values of IL-6 release as well as with average IL-6 release over the entire 60 min (r = 0.86, P < 0.006). The present data are compatible with a role for AMPK in IL-6 release during exercise or a role for IL-6 in activating AMPK. Alternatively, both AMPK and IL-6 are independent sensors of a low muscle glycogen concentration during exercise. In addition, leg release of IL-6 cannot alone explain the increase in plasma IL-6 during exercise.  相似文献   
87.
 CD44 isoforms have been implicated in tumor progression and metastasis formation. This study presents a thorough immunohistochemical analysis of CD44 standard and isoform expression in normal human skin appendages and epidermis applying monoclonal antibodies against CD44s, CD44v3, -v4, -v5, -v6, and -v9. An improved immunohistochemical protocol with microwave-based antigen retrieval in paraffin sections and heavy metal amplification of the diaminobenzidine reaction product provided enhanced resolution and sensitivity as compared to studies on frozen sections. The hair follicle, the seborrheic and eccrine sweat glands were strongly positive for all CD44 isoforms studied. In the latter, the clear cells but not the dark (intercalated) cells were positive. The sudoriferous ducts adjacent to the glands were weakly positive for all CD44 isoforms and strongly positive near the skin surface. In the apocrine glands, the basal cells showed only a moderate positivity. The myoepithelial cells expressed only CD44s. In the epidermis, all CD44 isoforms were detectable, with strongest CD44 immunostaining in the lower third of the stratum spinosum and weaker staining in the stratum basale and the upper two-thirds of the stratum granulosum. The stratum granulosum and corneum were unreactive. Thus, a regional and cell type-specific CD44 expression was revealed. Accepted: 10 May 1996  相似文献   
88.
TheAnticarsia gemmatalisnuclear polyhedrosis virus (AgNPV) was released in two soybean plots in September, 1991; the soil in the plots was then sampled periodically through July, 1992, to determine the effects of normal agricultural soil manipulations and precipitation on vertical distribution of the polyhedral occlusion bodies (POBs). The amount of AgNPV increased at all depths down to 37.5–50 cm as long as there was virus-contaminated plant matter, even dead soybean refuse, above the soil surface. Agricultural operations (disking, harrowing, mowing, planting, cultivating) had no effect on the amount or vertical distribution of AgNPV in soil. After the crop refuse was disked into the soil in November, the amount of POBs began decreasing at all depths; these decreases continued over winter and at times appeared to be associated with precipitation. The POBs were no longer detected below 37.5 cm by April, 1992, or below 25 cm by July, 1992. However, in July there were still 274 POBs/g in the top 2.5 cm of soil. Thus, agricultural operations should not hinder contamination of soybean leaves by AgNPV from its soil reservoir.  相似文献   
89.
The importance of the acarine predator, Zetzellia mali, in the control of phytophagous mites in apple orchards is not well understood. Zetzellia mali tends to prefer the eriophyid, Aculus schlechtendali, over the economically more significant tetranychid, Panonychus ulmi, but quite a wide range of preference values have been reported in the literature. In sets of laboratory choice trials, we determined that prey preference of this predator varies with the relative but not absolute density of its prey. We attempt to explain these results in terms of behavioural mechanisms and discuss the potential implications of our results for the effectiveness of Z. mali in the biological control of phytophagous mites in apple orchards.  相似文献   
90.
Abstract: The weaver mutant mouse (wv/wv) has an ~70% loss of nigrostriatal dopamine (DA) neurons, but the fractional DA release evoked by amphetamine (but not a high potassium level) has been shown to be greater from striatal slices of the weaver compared with +/+ mice. In the present work we tested the hypothesis that fractional DA release from weaver striatum would be greater when release was mediated by the DA transporter. Serotonin (5-HT)-stimulated fractional DA release was greater from weaver than from +/+ striatum. The release evoked by 5-HT in the presence of 10 µM nomifensine (an antagonist of the DA transporter) was less than in its absence, but the difference between weaver and +/+ striatum remained. In the presence of nomifensine, 1-(m-chlorophenyl)biguanide, classified as a 5-HT3 agonist, also induced a greater fractional release from weaver compared with +/+ striatum. When veratridine was used at a low concentration (1 µM), the fractional evoked release of DA was higher from the weaver in the presence and absence of nomifensine. These findings suggest that the reason for the difference in the responsiveness of the two genotypes to these release-inducing agents is not related to DA transporter function.  相似文献   
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