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311.
Thermoalkaliphilic Bacillus sp. strain TAR-1 isolated from soil produced an extracellular xylanase. The enzyme (xylanase R) was purified to homogeneity by ammonium sulfate fractionation and anion-exchange chromatography. The molecular mass of xylanase R was 40 kDa and the isoelectric point was 4.1. The enzyme was most active over the range of pH 5.0 to 10.0 at 50°C. The optimum temperatures for activity were 75°C at pH 7.0 and 70°C at pH 9.0. Xylanase R was stable up to 65°C at pH 9.0 for 30 min in the presence of xylan. Mercury(ll) ion at 1 mM concentration abolished all the xylanase activity. The predominant products of xylan-hydrolysate were xylobiose, xylotriose, and higher oligosaccharides, indicating that xylanase R was an endo-acting enzyme. Xylanase R had a Km of 0.82 mg/ml and a Vmax of 280 μmol min−1 mg−1 for xylan at 50°C and pH 9.0.  相似文献   
312.
The embryonic development of Zorotypus caudelli Karny (Zoraptera) is described with the main focus on its external features. A small heart‐shaped embryo is formed on the dorsal side of the egg by the fusion of paired blastoderm regions with higher cellular density. The orientation of its anteroposterior axis is opposed to that of the egg. This unusual condition shows the potential autapomorphy of Zoraptera. The embryo extends along the egg surface and after reaching its full length, it migrates into the yolk. After developing there for a period of time, it reappears on the surface, accompanied by a reversion of its anteroposterior axis, finally taking its position on the ventral side of the egg. The definitive dorsal closure completes, and the prelarva hatches after perforating the chorion with very long egg tooth formed on the embryonic cuticle. Embryological data suggest the placement of Zoraptera among the “lower neopteran” or polyneopteran lineage: features supporting this are embryo formation by the fusion of paired regions with higher cellular density and blastokinesis accompanied by full elongation of the embryo on the egg surface. The extraordinarily long egg tooth has potential synapomorphy with Embioptera or Eukinolabia (= Embioptera + Phasmatodea). Together with the results from our previous studies on the egg structure, male reproductive system and spermatozoa, the close affinity of Zoraptera with Eukinolabia appears likely, that is, a clade Zoraptera + (Embioptera + Phasmatodea). J. Morphol. 275:295–312, 2014. © 2013 Wiley Periodicals, Inc.  相似文献   
313.
Mechanisms of antifungal actions of cinnamaldehyde, citral, perillaldehyde and citronellal were investigated. The growth inhibitions by the aldehydes were reduced or abolished in the presence of cysteine or glutathione in some cases, indicating that the inhibitions were mainly due to reactions of the aldehydes with SH groups involved in the fungal growth. In other cases, the SH compounds were ineffective on the inhibitory actions of the aldehydes. By calculating energies of molecular orbitals of the aldehydes, it was found that the antifungal activity was related to the energy of the lowest empty molecular orbital, i.e., the lower the energy, the higher is the antifungal activity. The energy values of the molecular orbitals indicate that the aldehydes except citronellal are good electron acceptors. It was further demonstrated, by studies of difference spectra, that cinnamaldehyde, citral and perillaldehyde are capable of forming charge transfer complexes with tryptophan, a good electron donor. These results strongly suggest that the antifungal actions of the aldehydes are possibly due to their abilities to form charge transfer complexes with electron donors in addition to their reactivity with SH groups.  相似文献   
314.
In the machilid Pedetonutus unimaculatus, a germ disc is formed by the aggregation and proliferation of cells within a broadly defined embryonic area. Cells adjacent to the embryonic area form the serosal fold that grows beneath the embryo. Then the embryonic margin is extended to form a cell layer or amnion that lies between the embryo and serosal fold. Thus, an amnioserosal fold is formed by the addition of the amnion to the serosal fold. Serosal cells cover the entire surface of the egg and begin to secrete a serosal cuticle. Soon the amnioserosal fold is withdrawn, and the embryo is exposed to the egg surface. The spreading amnion replaces the serosal cells that finally degenerate through the formation of a secondary dorsal organ. In the areas of amnion anterior and lateral to the embryo, yolk folds form and encompass the embryo. The amnion is a provisional dorsal closure and never participates in the formation of the definitive one. The amnioserosal fold of the Microcoryphia appears to have the functional role of secreting a serosal cuticle beneath the embryo. This fold of the Microcoryphia may be regarded as an ancestral form of the amnioserosal folds of the Thysanura-Pterygota. the yolk folds may appear to be passive transformation of the yolk mass linked to positioning of the growing embryo within the egg. There is no evidence that the yolk folds and the cavity appearing between them in the Microcoryphia are homologous to the amnioserosal fold and amniotic cavity in the Thysanura-Pterygota. The yolk folds appear to be one of the embryological autapomorphies in the Microcoryphia. © 1994 Wiley-Liss, Inc.  相似文献   
315.
The transesterification of 0.5 M divinyladipate with 0.25 M arabinose in dimethylformamide for 7 days was catalyzed by Streptomyces sp. alkaline protease to give 5-O-vinyladipoyl-d-arabinofuranose at ca. 50% yield. Only enzymatic transesterification of primary hydroxyl group of arabinofuranose proceeded without esterification of arabinopyranose.  相似文献   
316.
Ordus chiayiensis isolated from discolored red pine needles is redescribed and illustrated.  相似文献   
317.
Many studies have highlighted the difficulty inherent to the clinical application of fundamental neuroscience knowledge based on machine learning techniques. It is difficult to generalize machine learning brain markers to the data acquired from independent imaging sites, mainly due to large site differences in functional magnetic resonance imaging. We address the difficulty of finding a generalizable marker of major depressive disorder (MDD) that would distinguish patients from healthy controls based on resting-state functional connectivity patterns. For the discovery dataset with 713 participants from 4 imaging sites, we removed site differences using our recently developed harmonization method and developed a machine learning MDD classifier. The classifier achieved an approximately 70% generalization accuracy for an independent validation dataset with 521 participants from 5 different imaging sites. The successful generalization to a perfectly independent dataset acquired from multiple imaging sites is novel and ensures scientific reproducibility and clinical applicability.

Biomarkers for psychiatric disorders based on neuroimaging data have yet to be put to practical use. This study overcomes the problems of inter-site differences in fMRI data by using a novel harmonization method, thereby successfully constructing a generalizable brain network marker of major depressive disorder across multiple imaging sites.  相似文献   
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