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Al0.1CoCrFeNi high-entropy alloys are firstly processed by cyclic dynamic torsion (DT) using Split-Hopkinson Torsional Bar. Gradient hierarchical microstructures produced by DT are investigated using electron backscattered diffraction, transmission electron microscopy, and nanoindentation tests. Based on the gradient torsional strain, significant grain refinement, remarkable work hardening, and hierarchical deformation substructures are introduced into the current DT-HEAs.

The cold drawing of magnesium wires has constantly been an obstacle in industrial manufacture due to the lack of sufficient independent slip system at ambient temperature and the frequent intermediate annealing gives rise to regrettably low production efficiency. Aiming at the technique challenge, a feasible and effective method of multi-pass cumulative cold drawing with small deformation per pass was utilized in this study and a wire of 0.625 mm in diameter was obtained out of primitive Φ2.0 mm material with the accomplishment of about 2.3 in cumulative strain (90% in area reduction), the efficiency of which was dramatically improved. The microstructure, texture and mechanical properties with the variation of cumulative area reduction were investigated. It can be apparently observed that continuous dynamic recrystallization had occurred during cold drawing. The outcomes are displayed as follows: the transition emerged from low angle grain boundary to high angle grain boundary; the increased fraction of undeformed/recrystallized structure first descended then ascended; the deformed structure initially appeared yet disappeared quickly. All of above owned an almost same critical point at around 23% cumulative area reduction. One of the most remarkable consequences of the deformation was the degeneration of the average grain size steadily from 11.8 to 3.1 µm. 〈10-10〉//DD fiber component was gradually transformed from the primitive {0002}//DD fiber texture and this deformation texture was continuously strengthened. The enhanced mechanical properties achieved uncommonly high strength of 214.5 MPa in yield strength and 256.9 MPa in ultimate tensile strength due to grain refinement arising from continuous dynamic recrystallization and intense fiber texture strengthening introduced during cold drawing.

An extracellular beta-xylosidase from the thermophilic fungus Paecilomyces thermophila J18 was purified 31.9-fold to homogeneity with a recovery yield of 2.27% from the cell-free culture supernatant. It appeared as a single protein band on SDS-PAGE with a molecular mass of approx 53.5 kDa. The molecular mass of beta-xylosidase was 51.8 kDa determined by Superdex 75 gel filtration. The enzyme was a glycoprotein with a carbohydrate content of 61.5%. It exhibited an optimal activity at 55 degrees C and pH 6.5, respectively. The enzyme was stable in the range of pH 6.0-9.0 and at 55 degrees C. The purified enzyme hydrolyzed xylobiose and higher xylooligosaccharides but was inactive against xylan substrates. It released xylose from xylooligosaccharides with a degree of polymerization ranging between 2 and 5. The rate of xylose released from xylooligosaccharides by the purified enzyme increased with increasing chain length. It had a K(m) of 4.3mM for p-nitrophenol-beta-d-xylopyranoside and was competitively inhibited by xylose with a K(i) value of 139 mM. Release of reducing sugars from xylans by a purified xylanase produced by the same organism increased markedly in the presence of beta-xylosidase. During 24-hour hydrolysis, the amounts of reducing sugar released in the presence of added beta-xylosidase were about 1.5-1.73 times that of the reaction employing the xylanase alone. This is the first report on the purification and characterization of a beta-xylosidase from Paecilomyces thermophila.

In order to investigate the antioxidative activity of Meitauza koji (Meitauza, a Chinese traditionally fermented okara), the okara was fermented with Aspergillus oryzae 3.951, Rhizopus oligosporus 3.912, Actinomucor elegans 3.118 and Bacillus subtilis B2 as kojis. All the methanol extract yields and peptide content of the kojis were higher than that of non-fermented okara. Moreover, the Meitauza kojis displayed enhanced antioxidative activities in comparison with the non-fermented okara. Among the four kinds of kojis tested, those fermented with B. subtilis B2 exhibited the highest levels of 2,2′-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals scavenging activities and reducing power. The ABTS and DPPH radicals scavenging activities of Meitauza koji fermented with B. subtilis B2 were ca. 12.53 and 7.92 folds that of the non-fermented okara. Analysis of the dose-response effect also revealed that before reaching a threshold point, there is a linear r...

The Mopan persimmon (Diospyros kaki L. cv. Mopan) is the major cultivar of astringent persimmon in northern China. This study investigates the radical scavenging activity against ABTS and DPPH radical, and the content of total and individual phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) with apple, grape, and tomato as controls. The radical scavenging activities against ABTS and DPPH radicals of the Mopan persimmon are 23.575 and 22.597 microm trolox eq/g f.w., respectively. These findings suggest that the Mopan persimmon's antioxidant activity is significantly (P < 0.05) stronger than that of reference materials. The Mopan persimmon showed the highest content of total phenolics among the 4 materials tested. Significant correlations (R(2)= 0.993, P < 0.05, ABTS radical; R(2)= 0.980, P < 0.05, DPPH radical) are found between the total phenolics and the radical scavenging activities. The total content of these 6 kinds of phenolics (catechin, epicatechin, epigallocatechin, chlorogenic acid, caffeic acid, and gallic acid) is significantly correlated (R(2)= 0.831, P < 0.05, ABTS radical; R(2)= 0.745, P < 0.05, DPPH radical) with the individual radical scavenging activity of the 4 materials, although the total content of the 6 phenolics accounts for no more than 20% of the total phenolics in the Mopan persimmon. Gallic acid exhibits the strongest antioxidant activity in all 6 kinds of phenolics and its content is the largest in the Mopan persimmon, presumably being responsible for its much higher antioxidant activity as compared to apple, grape, and tomato.

A newly isolated Bacillus subtilis WY34 produced high level of mannanase (1105 U/ml) when grown on konjac powder as the carbon source at 50 °C. The β-mannanase was purified 5.4-fold to homogeneity with a final recovery of 20.3% and a specificity of 8302.4 U/mg protein. The purified mannanase appeared as a single protein band on SDS–PAGE gel with a molecular mass of approx. 39.6 kDa. It was identified as a glycoprotein by periodic acid-Schiff staining with a carbohydrate content of 13.1%. The first 10 N-terminal amino acid sequence (HTVSPVNPNA) of the purified enzyme showed high homology (90% identity) with the N-terminal region of β-mannanase from B. subtilis NM-39. The optimal temperature and pH for mannanase activity was 65 °C and pH 6.0, respectively. The mannanase activity was stable within pH 5.5–10.1. It was stable up to 60 °C at pH 6.0. The mannanase was highly specific towards locust bean gum, but exhibited very low activity towards starch, CMC and birchwood xylan. Apparent Km values of the mannanase for locust bean gum, guar gum and konjac powder were 7.6, 10.5 and 27.4 mg ml−1, respectively. Copra mannan was degraded mainly to mannotetraose, mannobiose and mannotriose when incubated with the mannanase, suggesting that the mannanase is an endomannanase and is suitable for mannooligosaccharide production. These unique properties of the purified β-mannanase from B. subtilis WY34 make this enzyme attractive for biotechnological applications.

Thermomyces lanuginosus CAU44, a newly isolated thermophilic fungus strain, was used for the production of extracellular xylanase on various lignocellulosic materials under shake flask conditions. High-level production of xylanase by the strain was enhanced by optimizing the type of carbon sources, substrate concentration, particle size and surfactants in the culture medium. The titre of xylanase activity obtained of up to 4156 U ml−1 was the highest ever reported.

A 47 kDa xylanase (FXYN) from Streptomyces olivaceoviridis E-86 was immobilized on Eudragit S-100 and an immobilization efficiency of 90% was obtained. The optimum pH of the immobilized xylanase shifted from 5.8 to 6.3 while its optimum temperature moved from 60 to 65 °C. The immobilized enzyme also showed a higher thermal stability than the free xylanase. Only a marginal increase in the Km values of free enzyme was observed upon immobilization. However, Vmax values of the immobilized enzyme were 82–161% higher than those of the free xylanase. The immobilized xylanase was also evaluated for its application in hydrolyzing the corncob powder pre-treated with 2% NaOH solution for xylo-oligosaccharide production. The final extent of xylan hydrolysis using pre-treated corncob powder was 84% for the immobilized enzyme after 24 h of incubation at 55 °C. The immobilized xylanase retained 81% of its initial hydrolysis activity even after being recycled four times. Therefore, the immobilized xylanase is suitable to produce xylo-oligosaccahrides from corncob powder pre-treated with dilute alkaline solution.

Aims: A xylanase from the newly isolated thermophilic fungus, Thermomyces lanuginosus CAU44, was characterized and evaluated for its suitability in bread making. Methods and Results: Xylanase was purified 3·5-fold to homogeneity with a recovery yield of 32·8%. It appeared as a single protein band on SDS-PAGE gel with a molecular mass of c. 25·6 kDa. The purified xylanase had an optimum pH of 6·2, and it was stable over pH 5·6–10·3. The optimal temperature of xylanase was 75°C and it was stable up to 65°C at pH 6·2. Study was further carried out to investigate the effect of the purified xylanase on the properties of wheat bread and its staling during storage. Conclusions: The purified xylanase from T. lanuginosus CAU44 was stable up to 65°C and had a broad pH range. The presence of thermostable xylanase during bread making led to an improvement of the specific bread volume and better crumb texture. Besides, addition of xylanase provided an anti-staling effect. Significance and Impact of the Study: The xylanase from the newly isolated Thermomyces lanuginosus CAU44 shows great promise as a processing aid in the bread-making industry.

Besides affecting the xylanases production, different nitrogen sources present in the media also caused changes in the xylanosomal subunit composition of Streptomyces olivaceoviridis E-86. Four xylanosome fractions, purified from the culture supernatant of S. olivaceoviridis E-86 grown on different nitrogen sources, exhibited high specificity towards different xylans and were composed of different subunits. Thus, S. olivaceoviridis E-86 regulates the expression of xylanase activity and varies the xylanosome composition according to the nitrogen sources possibly through the action of the secreted proteases.

The recombinant xylanase B (XynB) of Thermotoga maritima MSB8 was characterized and was found to cleave p-nitrophenyl β- d -xyloside via the transglycosylation reaction in the previous study. XynB was activated in the presence of alcohols, and XynB activity was increased by iso-propanol (2 M) to 2.1-fold. This type of activation was investigated and was shown to be due to the transglycosylation activity with p-nitrophenyl β- d -xylobioside being converted to alkyl β- d -xylobiosides in the presence of XynB and alcohols. Through the transglycosylation reaction, alkyl β-xylosides and xylobiosides were simultaneously produced in the presence of xylan and alcohols. Primary alcohols were found to be the best acceptors. The highest yields of alkyl β-xylosides and xylobiosides were 33% and 50% of the total sugar, respectively. XynB showed a great ability to transfer xylose and xylobiose to secondary alcohol acceptors, and was unique for being able to synthesize the tertiary alkyl β-xylosides and xylobiosides with high yields of 18.2% and 11.6% of the total sugar, respectively. This is the first report of a xylanase with the ability to synthesize tertiary alkyl β-xylosides and xylobiosides. The specificity of the β-linkage was confirmed by the proton nuclear magnetic resonance ( 1 H NMR). Thus, XynB of T. maritima appears to be an ideal enzyme for the synthesis of useful alkyl β-xylosides and xylobiosides.

The xynB of a hyperthermophilic Eubacterium, Thermotoga maritima MSB8, coding xylanase B (XynB) was previously expressed in E. coli and the recombinant protein was characterized using the synthetic substrates [J. Biosci. Bioeng. 92 (2001) 423]. In this study, the same xylanase B was purified to homogeneity with a recovery yield of about 43% using heat treatment followed by the Ni-NTA affinity chromatography. The specificity of XynB towards different natural substrates was evaluated. XynB was highly specific towards xylans tested but exhibited low activities towards lichenan (19%), gellan gum (7.3%), laminarin (3.4%) and carboxymethylcellulose (CMC, 1.4%). The apparent Km values of birchwood xylan and soluble oat-spelt xylan was 0.11 and 0.079 mg/ml, respectively. The XynB hydrolyzed xylooligosaccharides to yield predominantly xylobiose (X2) and a small amount of xylose (X1), suggesting that XynB was possibly an endo-acting xylanase. Analysis of the products from birchwood xylan degradation confirmed that the enzyme was an endo-xylanase with xylobiose and xylose as the main degradation products. HPLC results showed that hydrolyzed products of birchwood xylan by XynB yielded up to 66% of the total reaction product as xylobiose. These results clearly indicated that xylobiose could be mass-produced efficiently by the recombinant hyperthermostable XynB of T. maritima. Additionally, conversion of xylobiose (50 mM) to xylose was observed, while xylotriose (X3) and xylotetraose (X4) were detected in small amounts, indicating that the enzyme converted xylobiose to xylose based on the transglycosylation reaction. The increased binding ability of XynB to Avicel and/or insoluble xylan was also observed indicating the possibilities of roles of surface-aromatic amino acid residues for such action. However, further investigations are required to prove this speculation.

The production of a novel, very large xylanolytic complex (xylanosome) by Streptomyces olivaceoviridis E-86 is reported. The molecular weight was approx. 1200 kDa as determined by native gradient gel electrophoresis. Corncob xylan was the best inducer of xylanosome formation. The xylanosome was produced when the organism was grown for 5 d between pH 4.5-6 and at 27.5 to 35 degrees C.

The effects of different factors on xylanase production by Streptomyces olivaceoviridis E-86 were studied under shake flask conditions. The best initial pH value of growth medium for xylanase production was pH 6.0. Corn cob xylan and beef peptone were the best C source and N source, respectively. The enzyme activity was doubled by addition of 1.5% (v/v) Tween-80 in the medium. By the combination of the above variables, the highest xylanase activity obtained was 1653 U/ml which is the highest ever reported from Streptomyces sp.

On the basis of analyzing the major advantages and disadvantages of the chaos, genetic and simulated annealing algorithms, the chaos genetic simulated annealing hybrid algorithm is presented according to the complementary advantages strategy. The basic thought is initializing the initial population of genetic algorithm with chaos variables, and then calculating by genetic simulated annealing method, at last adding a disturbance to the chromosomes whose fitness are smaller with the chaos method. The result indicates that the algorithm has strong global searching capability and quick speed on converging to the optimal solution.

Objective: To investigate the clinical and pathological characteristics of thyroid nodules, as well as to evaluate the significance of ultrasonographically detected thyroid calcification in the diagnosis of thyroid carcinomas. Methods: Retrospective data were studied from 1,051 consecutive patients who underwent a thyroidectomy in the Provincial Hospital of Fujian Medical University in South China between January 2003 and July 2006 for nodular thyroid disease. Complete sonographical information before surgery was only collected from 758 of the 1,051 patients. Results: Among the 1,051 patients, benign lesions were found in 857 (81.54%) patients, of whom 612 (71.41%) were nodular goiter; malignant lesions were found in 194 (18.46%) patients, in whom benign thyroid lesions were also found in 85 (43.81%) patients. A total of 48 patients suffered from microcarcinomas, of whom 37 patients had benign lesions; these 37 accounted for 43.53 and 77.08%, respectively, of the 85 malignant cases with benign lesions and the 48 cases with microcarcinomas. In the 758 patients who underwent thyroid ultrasonography before surgery, intrathyroidal calcifications were apparent in 243 patients (32.06%). The incidence of calcification was significantly higher in patients with thyroid carcinoma (54.17%) than in those with benign lesions (26.87%; p < 0.005). Detection of calcification in thyroid lesions by ultrasound had a sensitivity of 32.38% and a specificity of 87.35%, with an OR of 3.31 (95% CI, 2.24–4.63), positive likelihood ratio of 2.56, negative likelihood ratio of 0.77 and a κ value of 0.23. Conclusion: Thyroid carcinoma, especially microcarcinoma, often coexists with benign thyroid disease. Calcification detected by thyroid ultrasound represents a risk factor for malignancy, but is of limited use as a sole marker of malignancy.

In this study, a thermostable recombinant xylanase B (XynB) from Thermotoga maritima MSB8 was immobilized on nickel-chelated Eupergit C 250L. This immobilized XynB was then used to hydrolyze the autohydrolysis explosion liquor of corncob (AELC) in a packed-bed enzyme reactor for continuous production of xylooligosaccharides, especially xylobiose. When tested in batch hydrolysis of AELC, the immobilized XynB still retained its relative activity of 92.5% after 10 cycles of hydrolysis at 90 degrees C. The immobilized XynB retained 83.6% of its initial hydrolysis activity even after 168 h of hydrolysis reaction at 90 degrees C and demonstrated a half-life time of 577.6 h (24 days) for continuous hydrolysis. HPLC showed that xylobiose (49.8%) and xylose (22.6%) were the main hydrolysis products yielded during continuous hydrolysis. Xylobiose was adsorbed on an activated charcoal column and eluted with a linear gradient of 15% (v/v) ethanol to yield xylobiose with 84.7% of recovery. Also, the purity of xylobiose was up to 97.2% as determined by HPLC. Therefore, the immobilized XynB was suitable for the efficient production of xylobiose from AELC. This is the first report on the immobilization of xylanase for xylobiose production.

A xylanolytic complex (xylanosome) was isolated from Streptomyces olivaceoviridis E-86 grown on corncob xylan. The isolated xylanosome exhibited a high molecular mass of approximately 3.8 × 107 Da (weight average) using size exclusion chromatography/multi-angle laser light scattering (SEC/MALLS), and was composed of at least 8 subunits with a mass range from 12 to 60 kDa. When a SDS-polyacrylamide gel zymogram was examined, the subunits of 47, 35, 32, and 23 kDa were found to have xylanase activity, while the 30-kDa subunit had CMCase activity. According to N-terminal sequence analyses, the 47- and 23-kDa subunits were found to be identical to the two reported xylanases, namely FXYN and GXYN, of S. olivaceoviridis E-86. Both the 35- and 32-kDa subunits were found to be truncated forms of the intact FXYN xylanase that possibly resulted from the degradation by proteases. The 15-kDa subunit consisted solely the xylan-binding domain of the FXYN xylanase. The purified xylanosome appeared to bind partially to xylan and poorly to Avicel.

The production of extracellular xylanase by a newly isolated thermophilic fungus, Paecilomyces themophila J18, on the lignocellulosic materials was studied in solid-state fermentation (SSF). The strain grew well at 50 °C and produced a high-level of xylanase activity using the selected lignocellulosic materials, especially wheat straw. Production of xylanase by P . themophila J18 on wheat straw was enhanced by optimizing the particle size of wheat straw, nitrogen source, initial moisture level, growth temperature and initial pH of the culture medium. Under the optimized conditions, yield as high as 18 580 U g −1 of carbon source of xylanase was achieved. No CMCase activity was observed. The xylanase exhibited remarkable stability and retained more than 50% of its original activity at 70 °C for 4 h at pH 7.0–8.0. Therefore, P . themophila J18 could to be a promising microorganism for thermostable, cellulase-free xylanase production in SSF.

Dielectric ageing behaviors of lead-based relaxor ferroelectric ceramics, which may affect their application in multilayer ceramic capacitors (MLCs), have been an important research problem for many years. In this paper, the effects of annealing on ageing properties of the PMN-0.1PT system, respectively doped with Fe, Co and Ni ions and annealed in different atmospheres (air and N/sub 2/-H/sub 2/) after sintering, were studied. It is found that the annealing atmosphere has a strong influence on the ageing degree of the samples. For the air-annealed samples, the decrease in the dielectric constant was small; whilst for the N/sub 2/H/sub 2/-annealed samples, the decrease was much greater. It is assumed that the different valences of doped ions, resulting from the different annealing atmospheres, are responsible for the different ageing degrees.

The effects of different thermal shock treatments on dielectric and electrical properties of relaxor based and BaTiO/sub 3/ based "0805" Y5V multilayer ceramic chip capacitors (MLCs) were investigated. It was found that thermal shock generally resulted in larger leakage currents and lower breakdown voltages. It is also confirmed that the thermal shock resistance of relaxer MLCs is in disadvantage to that of the barium titanate MLCs. Nevertheless, no obvious failure was found when the relaxor-based MLCs were subjected to the thermal effects in the normal infrared solder reflow process. Besides the relatively lower mechanical strength, low insulation resistivity and breakdown strength were also proposed to be important contributors to the undesirable reliability of relaxor MLCs.

Bagcheea taiwanensis sp. nov. on Cyclobalanopsis stenophylloides is described and illustrated.