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421.
Ryutaro Kakinuma Noriyuki Moriyama Yukio Muramatsu Shiho Gomi Masahiro Suzuki Hirobumi Nagasawa Masahiko Kusumoto Tomohiko Aso Yoshihisa Muramatsu Takaaki Tsuchida Koji Tsuta Akiko Miyagi Maeshima Naobumi Tochigi Shun-ichi Watanabe Naoki Sugihara Shinsuke Tsukagoshi Yasuo Saito Masahiro Kazama Kazuto Ashizawa Kazuo Awai Osamu Honda Hiroyuki Ishikawa Naoya Koizumi Daisuke Komoto Hiroshi Moriya Seitaro Oda Yasuji Oshiro Masahiro Yanagawa Noriyuki Tomiyama Hisao Asamura 《PloS one》2015,10(9)
PurposeThe image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners.ResultsThe image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU]) was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001). The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001) for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.ConclusionDespite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners. 相似文献
422.
Construction of Nest Defensive Structure According to Offspring Value and Its Effect on Predator's Attack Decision in Paper Wasps 下载免费PDF全文
Various organisms are known to build nests with defensive structures to protect their offspring from predation, but our understanding of plasticity in the nest structure remains poor. In this study, we investigated whether a paper wasp, Polistes chinensis antennalis, adjusted the construction of nest defensive structure according to the value of their offspring, and we also analysed the effect of adjusting the construction of the structure on predator's decision to attack. P. chinensis antennalis foundresses start a colony and maintain her nest alone until the emergence of workers. During this stage, foundresses often construct a defensive structure on cocoon caps of pupae using nest materials (pulp), which prevents predation of pupae by conspecifics from other nests. The value of pupae to the foundress varies among those in a nest, where the value is higher in pupae that spun the cocoon (and initiated pupation) earlier than other pupae in the nest. From field observations, we found that foundresses constructed a larger pulp structure on the cocoons of pupae that cocooned earlier in the order of cocoon spinning, even after considering confounding factors. We also found that the probability of a pupa being attacked by conspecific intruders decreased with the size of pulp structure on the cocoon. This indicates that intruders avoid attacking cocoons with larger pulp structures. Our study indicates that foundresses adjust the construction of nest defensive structures according to their offspring value, and this allows them to protect the high‐value offspring efficiently and effectively. 相似文献
423.
Withdrawal of Survival Factors Results in Activation of the JNK Pathway in Neuronal Cells Leading to Fas Ligand Induction and Cell Death 总被引:31,自引:3,他引:28 下载免费PDF全文
Helen Le-Niculescu Emanuela Bonfoco Yoshitoshi Kasuya Francois-Xavier Claret Douglas R. Green Michael Karin 《Molecular and cellular biology》1999,19(1):751-763
The JNK pathway modulates AP-1 activity. While in some cells it may have proliferative and protective roles, in neuronal cells it is involved in apoptosis in response to stress or withdrawal of survival signals. To understand how JNK activation leads to apoptosis, we used PC12 cells and primary neuronal cultures. In PC12 cells, deliberate JNK activation is followed by induction of Fas ligand (FasL) expression and apoptosis. JNK activation detected by c-Jun phosphorylation and FasL induction are also observed after removal of either nerve growth factor from differentiated PC12 cells or KCl from primary cerebellar granule neurons (CGCs). Sequestation of FasL by incubation with a Fas-Fc decoy inhibits apoptosis in all three cases. CGCs derived from gld mice (defective in FasL) are less sensitive to apoptosis caused by KCl removal than wild-type neurons. In PC12 cells, protection is also conferred by a c-Jun mutant lacking JNK phosphoacceptor sites and a small molecule inhibitor of p38 mitogen-activated protein kinase and JNK, which inhibits FasL induction. Hence, the JNK-to-c-Jun-to-FasL pathway is an important mediator of stress-induced neuronal apoptosis. 相似文献
424.
An aldose reductase inhibitor prevents the glucose-induced increase in PDGF-beta receptor in cultured rat aortic smooth muscle cells. 总被引:1,自引:0,他引:1
Y Kasuya J Nakamura Y Hamada M Nakayama H Sasaki T Komori S Chaya G Watanabe K Naruse E Nakashima K Kato N Hotta 《Biochemical and biophysical research communications》1999,261(3):853-858
To examine the role of platelet-derived growth factor (PDGF) and the polyol pathway in the growth activity of smooth muscle cells (SMCs), [(3)H]-thymidine incorporation, [(125)I]-PDGF-BB binding and expression of PDGF-beta receptor protein were measured in rat aortic SMCs cultured with 5.5 or 20 mM glucose with or without anti-PDGF antibody or an aldose reductase inhibitor, epalrestat. SMCs cultured with 20 mM glucose demonstrated an accelerated thymidine incorporation compared with SMCs cultured with 5.5 mM glucose, which was prevented by anti-PDGF antibody. This acceleration of growth activity by 20 mM glucose was accompanied by an increase in PDGF-BB binding, which was due to the increased number of PDGF-beta receptors and the overexpression of PDGF-beta receptor protein. Epalrestat prevented all these abnormalities. These observations suggest that polyol pathway hyperactivity plays an important role in the proliferation of SMCs which may be mediated through the accelerated expression of PDGF-beta receptor protein. 相似文献
425.
Ken-ichi Kasuya Takeshi Ohura Kozue Masuda Yoshiharu Doi 《International journal of biological macromolecules》1999,24(4):1531-336
The substrate specificities of three extracellular polyhydroxybutyrate (PHB) depolymerases from Alcaligenes faecalis (PhaZAfa), Pseudomonas stutzeri (PhaZPst), and Comamonas acidovorans (PhaZCac), which are grouped into types A and B based on the position of a lipase box sequence in the catalytic domain, were examined for films of 12 different aliphatic polyesters. Each of these PHB depolymerases used was capable of hydrolyzing poly(3-hydroxybutyrate) (P(3HB)), poly(3-hydroxypropionate) (P(3HP)), poly(4-hydroxybutyrate) (P(4HB)), poly(ethylene succinate) (PESU), and poly(ethylene adipate) (PEA) but could not hydrolyze another seven polyesters. In addition, the binding characteristics of substrate binding domains from PhaZAfa, PhaZCac, and PHB depolymerase from Comamonas testosteroni (PhaZCte) were studied by using fusions with glutathione S-transferase (GST). All of fusion proteins adsorbed strongly on the surfaces of polyester granules of P(3HB), P(3HP), and poly(2-hydroxypropionate) (P(2HP)) which was not hydrolyzed by the PHB depolymerases used in this study, while they did not bind on Avicel and chitin granules. The adsorption kinetics of the fusion proteins to the surface of P(3HB) and P(2HP) granules were found to obey the Langmuir isotherm. The cross-area per molecule of fusion protein bound to P(3HB) granules was estimated to be 12±4 nm2/molecule. It has been suggested that the active sites in catalytic domains of PHB depolymerases have a similar conformational structure, and that several amino acids in substrate-binding domains of PHB depolymerases interact specifically with the surface of polyesters. 相似文献
426.
Hisako Urabe Yoko Sugawara Motowo Tsukakoshi Akira Ikegami Hitoshi Iwasaki Takahiro Kasuya 《Biopolymers》1987,26(6):963-971
Low-frequency Raman spectra of the self-associates of guanosine monophosphates (GMPs) Na2 · 5′GMP, K2 · 5′GMP, Na2 · 3′GMP, and K2 · 3′GMP, and polyribonucleic acid K · poly(rG), were obtained. In acidic gels and dried fibers, GMP molecules are known to form helical stacks of hydrogen-bonded tetramers. Some low-frequency collective modes specific to the helically stacked structures were observed. We examined the dependence of these modes on counterions and water content. The lowest frequency mode at ca. 20 cm?1 is sensitive to the water content of the sample and is clearly visible in solid-state samples, so it works as a marker band of the environmental condition of the helices. The intensity and the peak frequency of this mode in solid-state samples depend on the helical structure and counterions. The broad peaks in the vicinity of 100 cm?1 are influenced by cations and are independent of water content. 相似文献
427.
Hybridization and Polyploidization of Saccharomyces cerevisiae Strains by Transformation-Associated Cell Fusion 下载免费PDF全文
Hybrid or polyploid clones of Saccharomyces cerevisiae produced by protoplast fusion were easily isolated by selecting transformants with the plasmid phenotype because the transformation was directly associated with cell fusion. When haploid cells were used as the original strain, the transformants were mostly diploids with a significant fraction of polyploids (triploids or tetraploids). Repeated transformation after curing the plasmid gave rise to clones with higher ploidy, but the frequency of cell fusion was severely reduced as ploidy increased. 相似文献
428.
Hirotaka Shiba Toshiyuki Kawasumi Yasuo Igarashi Tohru Kodama Yasuji Minoda 《Archives of microbiology》1985,141(3):198-203
The incorporation of 14CO2 by the cell suspensions of an extremely thermophilic, aerobic hydrogen-oxidizing bacterium, Hydrogenobacter thermophilus was studied. After short time incubation of the cell suspensions with 14CO2, the radiactivity was initially present in aspartate, glutamate, succinate, phosphorylated compounds, citrate, malate and fumarate. All of these compounds except phosphorylated compounds were related to the members of the tricarboxylic acid cycle. The proportion of labelled aspartate onglutamate in total radioactivity on each chromatogram decreased with incubation time, while the percentage of the radioactivity incorporated in phosphorylated compounds increased with time up to 10 s. These indicated that aspartate and glutamate is derived from primary products of CO2 fixation.In cell-free extracts of Hydrogenobacter thermophilus, the two key enzymes in the Calvin cycle, ribulose-1,5-bisphosphate carboxylase and phosphoribulokinase could not be detected. The key enzymes of the reductive tricarboxylic acid cycle, fumarate reductase and ATP citrate lyase were present. Activities of phosphoenolpyruvate synthetase and pyruvate carboxylase were also detected. The referse reactions (dehydrogenase reactions) of -ketoglutarate synthase and pyruvate synthase could be detected by using methyl viologen as an electron acceptor.These findings strongly suggested that a new type of the reductive tricarboxylic acid cycle operated as the CO2 fixation pathway in Hydrogenobacter thermophilus. 相似文献
429.
Eiiti Kasuya 《Journal of Ethology》1983,1(1-2):34-45
Behavioral catalogues, transition matrices between 2 consecutive behavioral acts, and the frequency distribution of time spent
in each behavioral act were described for queens and workers of a Japanese paper wasp,Polistes chinensis antennalis in the ergonomic stage (the period from the emergence of the first worker to the emergenece of the first reproductive). The
results were; (1) The whole behavior repertoire of queens was completely included in that of workers. Workers oviposited frequently
in queen-right colonies. (2) The proportion of off-nest activities to the number of total acts for workers was higher than
that for queens. The proportion of time spent off the nest in workers was 5 times as high as that in queens. (3) There was
no significant difference in the proportion of number of oviposition to the total number of acts between queens and workers.
The oviposition rate was 0.06 eggs/h for workers and 0.37 eggs/h for queens. Queens made more dominance behavior and workers
more subordinated behavior. Queens made abdomen wagging more frequently than workers. (4) For behavioral acts common in both
queens and workers, the mean duration of a specific act was approximately equal for both. The mean duration of unsuccessful
flesh collection for workers was 3.4 times as longs as that for queens. Workers did not search for flesh in 10.1% of duration
of flesh collections in the field. (5) The pattern of transitions between 2 consecutive behavioral acts in workers was similar
to that in queens. (6) Alien workers approaching a nest with a load were more often accepted by the nest occupants than alien
workers with no load. Alien workers with no load were not accepted as often as a legitimate nestmates with no load. The reproductive
division of labor between queens and workers inP. chinesis antennalis was incomplete. This suggests worker-queen conflict in different reproductive strategies among colony members. Several behaviors
were consistent with the view that they are the behavioral expression of this conflict. 相似文献
430.