B-Z-空间的drop性质与弱drop性质

引入了B-Z-空间的drop性质与弱drop性质的概念,讨论了在B-Z-空间中drop性与弱drop性的相关性质;并且证明了B-Z-空间具有drop性质等价于它的次范数·具有drop性质;同时得出B-Z-空间具有drop性质当且仅当它具有(H)性质且是自反的.

Construction of Fusion Expression Vector of α-galactosidase-EGFP in Cucumber

[Objective] The research aimed to construct the fusion protein expression vector of α-galactosidase-EGFP （enhanced green fluorescent protein） in cucumber controlled by CaMV35S promoter.[Method] CaMV35S promoter sequence and the coding region of EGFP were amplified by polymerase chain reactions （PCR） with vector pCambia 1303 as the template.Using reverse transcript PCR technology,with total RNAs of cucumber as template,the coding region of acid α-galactosidase Ⅰ in cucumber was amplified.The above three fragments were inserted into the multiple cloning sites of expression vector pCambia 1381c.The fusion expression vector of α-galactosidase-EGFP located at the C-terminal of the target genes was constructed.[Result] After enzyme digestion and sequencing,the fusion expression of α-galactosidase-EGFP in cucumber was constructed successfully.[Conclusion] The research laid the experimental basis for further study on the subcellular localization of α-galactosidase in cucumber.

Physicochemical Characters of rPoIFN-α and Its Antiviral Activity in vitro

[Objective]The research aimed to test and identify the physicochemical characters and antiviral activity in vitro of semi-finished product of the recombinant porcine rPoIFN-α. [Method]HEp-2/VSV system was used to test the antiviral activity of three batches of rPoIFN-α. Using recombinant human IFN-α as reference,the titer of interferon was measured. The semi-finished product of rPoIFN-α with the known titer were treated with 0.25% trypsin,HCl and mouse anti-porcine IFN-α monoclonal antibody. And the anti-viral activity of each batch of rPoIFN-α was detected. The physicochemical characters of rPoIFN-α were evaluated. The inhibition of induced cytopathic effect of rPoIFN-α on PPV （Porcine parvovirus） and PRV （Porcine pseudorabies） on swine kidney cell （PK-15） was determined. And the antiviral activity of rPoIFN-α in vitro was observed. [Result]The titers of semi-finished products of rPoIFN-α titrated by HEp-2/VSV system could reach 1.5×105 IU/ml,with the specific activity of 1.1×106 IU/mg. The residual rate of the tier of rPoIFN-α treated by 0.25% trypsin at 37 ℃ for 1 h was less than 1%. And that treated with HCl （pH of 2.0） for 72 h was up to 95%. And that treated at 56 ℃ for 30 min and that treated by mouse anti-porcine IFN-α monoclonal antibody at 37 ℃ for 1 h were higher than 47% and about 1% respectively. The antiviral test in vitro showed that 50 and 500 IU/ml rPoIFN-α could inhibit the induced cytopathic effect of PRV and PPV on PK-15 cell lines. [Conclusion]rPoIFN-α had the basic physicochemical characters of IFN-α. And it could inhibit the induced cytopathic effect of PRV and PPV on PK-15 cell lines,but there was dosage difference.

Effect of Al-deposition on erosion resistance of plasma sprayed thermal barrier coating

A columnar Al film was firstly deposited on the top of 7%Y2O3？stabilized zirconia （7YSZ） ceramic coating in thermal barrier coating （TBC） system by magnetron sputtering. A vacuum treatment was then carried out at 700 °C for 1 h and 900 °C for 5 h to improve the erosion resistance of Al-deposited TBC. Aα-Al2O3 layer was in situ synthesized on the top of 7YSZ coating via vacuum heat treatment. The microstructure evolution of Al-deposited TBC illustrated that a loose surface-layer and a dense sub-layer formed on the top of 7YSZ coating after vacuum treatment. The phase structures of the as-sprayed TBC and the Al-deposited TBC after vacuum heat treatment were characterized by X-ray diffraction （XRD） and transmission electron microscope （TEM） assisted with focused ion beam （FIB）. Particulate erosion resistances of the as-sprayed TBC and treated TBC were compared at room temperature. In addition, erosion mechanism and schematic diagram were proposed. The results show that the Al-deposited TBC after vacuum heat treatment has better particulate erosion resistance than the as-sprayed one.

Polymerization Mechanism of α-Linear Olefin

The density functional theory on the level of B3LYP/6-31G was empolyed to study the chain growth mechanism in polymerization process of α-linear olefin in TiCl3/AlEt2Cl catalytic system to synthesize drag reduction agent. Full parameter optimization without symmetry restrictions for reactants, products, the possible transition states, and intermediates was calculated. Vibration frequency was analyzed for all of stagnation points on the potential energy surface at the same theoretical level. The internal reaction coordinate was calculated from the transition states to reactants and products respectively. The results showed as flloes： （i） Coordination compounds were formed on the optimum configuration of TiCl3/AlEt2Cl.（ii） The transition states were formed. The energy di？erence between transition states and the coordination compounds was 40.687 kJ/mol. （iii） Double bond opened and Ti-C（4） bond fractured, and the polymerization was completed. The calculation results also showed that the chain growth mechanism did not essentially change with the increase of carbon atom number of α-linear olefin. From the relationship between polymerization activation energy and carbon atom number of the α-linear olefin, it can be seen that the α-linear olefin monomers with 6-10 carbon atoms had low activation energy and wide range. It was optimum to synthesize drag reduction agent by polymerization.

Studies on the Isolation and Screening of α-amylase Producing Strain and Their Enzymatic Properties

[Objective] The aim was to obtain α-amylase producing strains with some excellent properties like high temperature resistance,strong acid resistance,strong alkali resistance,etc..[Method] α-amylase producing strains were isolated and screened; furthermore their enzymatic properties were studied.[Result] 10 strains with an obvious starch hydrolysis cycle were screened out from starch screening plate coated by diluted sample,from which 3 strains with higher α-amylase activity were screened out,that was X6,X8 and X10.As for X6,X8 and X10,their optimum pH values all belonged to neutral,and their optimum temperatures were all 60 ℃.Meanwhile,Ca^2＋ could increase their enzyme thermal stability.When the concentration of Ca^2＋ was 0.02-0.04 mol/L,the enzyme thermal stability of X6 and X8 reached the highest; When the concentration of Ca^2＋ was 0.03-0.04 mol/L,that of X10 reached the highest; When the concentration of Ca^2＋ was increased continuously,those of the 3 strains all decreased.[Conclusion] The research provides theoretical basis for satisfying the demands of different industries for α-amylase with different characteristics.

Influence of nano-CeO_2 on coating structure and properties of electrodeposited Al/α-PbO_2/β-PbO_2

Al/α-PbO2/β-PbO2 composite electrodes doped with rare earth oxide （CeO2） were prepared by anodic oxidation method investigate the influence of nano-CeO2 dopants on the properties of Al/α-PbO2/β-PbO2-CeO2 electrodes and the impact of α-PbO2 as the intermediate layer. The results show that using α-PbO2 as the intermediate layer will benefit the crystallization of β-PbO2 and β-PbO2 is more suitable as the surface layer than α-PbO2. CeO2 dopants change the crystallite size and crystal structure, enhance the catalytic activity, and even change the deposition mechanism of PbO2. The doping of CeO2 in the PbO2 electrodes can enhance the electro-catalytic activity, which is helpful for oxygen evolution, and therefore reduce the cell voltage.

Ionic Conduction and Fuel Cell Performance of Ba0.98Ce0.8Tm0.2O3-α Ceramic

The perovskite-type oxide solid solution Ba0.98Ce0.8Tm0.2O3-α was prepared by high temperature solid-state reaction and its single phase character was confirmed by X-ray diffraction. The conduction property of the sample was investigated by alternating current impedance spectroscopy and gas concentration cell methods under different gases atmospheres in the temperature range of 500-900 ℃. The performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured. In wet hydrogen, the sample is a pure protonic conductor with the protonic transport number of 1 in the range of 500-600 ℃, a mixed conductor of proton and electron with the protonic transport number of 0.945-0.933 above 600 ℃. In wet air, the sample is a mixed conductor of proton, oxide ion, and electronic hole. The protonic transport numbers are 0.010-0.021, and the oxide ionic transport numbers are 0.471-0.382. In hydrogen-air fuel cell, the sample is a mixed conductor of proton, oxide ion and electron, the ionic transport numbers are 0.942 0.885. The fuel cell using Ba0.98Ce0.8Tm0.2O3-α as solid electrolyte can work stably. At 900 ℃, the maximum power output density is 110,2 mW/cm2, which is higher than that of our previous cell using Ba0.98Ce0.8Tm0.2O3-α （x〈≤1, RE=Y, Eu, Ho） as solid electrolyte.

Response of soil fungal community to long-term chromium contamination

To further study the fungal community in heavy metal contaminated ecosystems,soil samples were collected from an abandoned chromium(Cr)factory,and fungal community was analyzed by Illumina sequencing of Internal Transcribed Spacer(ITS)amplicons.The results showed that Cr contamination changed the composition and structure of soil fungal community,but didn’t change the diversity.Fungus showed various responses to Cr contamination.LEfSe analysis revealed that the biomarker changed a lot in the Cr-contaminated samples in comparison with that in the control samples.The changes in fungal community may be caused by the direct toxic effects on fungi by high concentration of Cr and the significant change in soil properties resulting from Cr contamination.Among all the Cr fractions,organic matter-bound Cr and exchangeable Cr showed significant effects on the fungal community and organic matter also showed a significant effect on soil fungal community.

Microstructure and mechanical properties of TC21 titanium alloy by near-isothermal forging

Microstructure and tensile properties of TC21 titanium alloy after near-isothermal forging with different parameters plus solution treatment and aging were investigated. It is found that the residual β matrix, which was strengthened by fine secondary α platelets forming during aging, exists in all the samples; while primary equiaxed α phase, bent lamellar α phase and α plates are simultaneously or individually present in one sample. The strength of alloy increases proportionally with increasing the content of residual β matrix, which is the result of increasing α/β interphase boundary. The plasticity of alloy has a downward trend as the content of residual β matrix increases. This attributes to the increase of fine secondary α platelets, which are cut by dislocations during the deformation. Additionally, coarse α plates with long axis parallel to the maximum resolved shear stress（MRSS） also reduce the plasticity of TC21 alloy.

Interferon-伪 plus lamivudine vslamivudine reduces breakthroughs, but does not affect sustained response in HBeAg negative chronic hepatitis B

AIM： To investigate the efficacy of combination treatment of IFN-α and lamivudine compared to lamivudine monotherapy, after 24 mo of administration in HBeAgnegative hepatitis B patients. METHODS： Fifty consecutive patients were randomly assigned to receive IFN-α-2b （5 MU thrice per week, n = 24） plus lamivudine （100 mg daily） or lamivudine only （n = 26） for 24 mo. Patients were followed up for further 6 mo. The primary outcome was the proportion with sustained virological response （undetectable serum HBV DNA concentrations） and or sustained biochemical response （transaminase levels within normal range） at 30 mo （6 mo after the end of therapy）. Secondary end-points were timed from initial virological （biochemical） response to VBR （BBR, respectively） and the emergence of YMDD mutants across the two arms. RESULTS： Five of twenty-four （21%） patients in the combination arm vs 3/26 （12%） in the lamivudine arm had sustained response （i.e., normal serum transaminase levels and undetectable HBV DNA by PCR assay） 6 mo after treatment discontinuation. A reduction in the emergence of YMDD mutants and in the development of virological breakthroughs was observed in patients receMng combination treatment （10% vs46% , P= 0.01 and 14% vs46% , P= 0.03, respectively）. Time from initial virologic response to virologic breakthrough （VBR） was greater among initial responders receiving combination treatment compared to those receiving lamivudine （22.9 mo vs 15.9 mo, respectively; P = 0.005）.CONCLUSION： Our results demonstrate that IFN-α plus lamivudine combination therapy does not increase the sustained response, compared to lamivudine. However, combination therapy reduces the likelihood of VBR due to YMDD mutants and prolongs the time period until the breakthrough development.

Psychiatric side effects of pegylated interferon alfa-2b as compared to conventional interferon alfa-2b in patients with chronic hepatitis C

AIM: To assess systematically the spectrum and extent of depressive symptoms comparing patient groups receiving peginterferon or conventional interferon.METHODS: Ninety-eight patients with chronic hepatitis C and interferon-based therapy (+ribavirin) were consecutively enrolled in a longitudinal study. Patients were treated with conventional interferon alfa-2b (48/98patients; 5 MIU interferon alfa-2b thrice weekly) or peginterferon alfa-2b (50/98 patients; 80-150 μgpeginterferon alfa-2b) in combination with weight-adapted ribavirin (800-1 200 mg/d). Repeated psychometric testing was performed before, three times during and once after antiviral therapy: Depression was evaluated by the Hospital Anxiety and Depression Scale (HADS), anger/hostility by the Symptom Checklist-90 Items Revised (SCL-90-R).RESULTS: Therapy with pegylated interferon alfa-2bproduces comparable scores for depression (ANOVA:P = 0.875) as compared to conventional interferon.Maximums of depression scores were even higher and cases of clinically relevant depression were frequent during therapy with peginterferon. Scores for anger/hostility were comparable for both therapy subgroups.CONCLUSION: Our findings suggest that the extent and frequency of depressive symptoms in total are not reduced by peginterferon. Monitoring and management of neuropsychiatric toxicity especially depression have to be considered as much as in antiviral therapy with unmodified interferon.

Changes in tree species diversity and dominance across a disturbance gradient in Nepalese Sal (Shorea robusta Gaertn. f.) forests

Disturbance is often touted as a management tool, as moderate disturbance is believed to enhance diversity; thus an understanding of frequent and fluctuating disturbance regimes in forests and their effects on stand structure, dominance and diversity is very crucial. Here, the effects of different disturbance regimes, along a gradient, on diversity and dominance of five Shorea robusta Gaertn. f.-dominated forests were investigated in 25 one-ha plots in Nepal. A total of 67 tree species were recorded; of which 41 species were encountered in least disturbed and 10 species in beavily disturbed forest. Significant variations among forests were observed for all measures of alpha diversity. Alpha diversity measures declined linearly along a disturbance gradient while dominance increased linearly. Relative basal area of S. robusta increased as the level of disturbance increased, which in turn produced more than two-fold higher important value index in heavily disturbed forest than the least disturbed forest. All alpha diversity measures declined in an order of three with increasing relative basal area of S. robusta. The similarity in species composition between each pair of disturbed forests was generally low （Jaccard＇s similarity index 〈 57%）, suggesting a higher Beta diversity, It can be concluded that diversity of Sal forests declines with increasing magnitude of disturbance, which in turn favors a higher domi- nance of S. robusta. Controlling the population of the dominant species, mainly S. robusta, is recommended to enhance diversity and to achieve multiple-use forest management objectives.

TUMOR NECROSIS FACTOR-ALPHA POLYMORPHISM AND SECRETION IN MYASTHENIA GRAVIS

Objective To analyze the relationship between tumor necrosis factor-alpha (TNFα) gene promoter -308 polymorphism and myasthenia gravis (MG) in Chinese and analyze secretion of TNFα in peripheral blood mononuclear cells (PBMC) in MG patients. Methods A biallelic polymorphism at position -308 in the promoter of TNFα gene was screened by PCR amplification and NcoI recognition site. One hundred and twenty-three MG cases and 115 healthy controls were included in this study. MG patients were classified to different groups according to clinical type, age at onset, and sex respectively. PBMC were isolated from 20 patients and 20 healthy controls, and then cultured in the presence or absence of phytohemag- glutinin (PHA) and acetycholine receptors (AchR). The supernatants were harvested after incubation and stored until TNFα was assayed by enzyme-linked immunosorbent assay. Results The frequency of TNFα-308 allele 2 (A) was found significantly increase in MG patients and showed a trend especially in late onset (≥ 40 years) and male patients (P < 0.05). The allele A had no relationship with thymic pathogenesis in MG patients. But frequency of allele A was significantly higher in general type than in ocular type (P < 0.05). MG patients had a higher inducible level of TNFα by PHA and AchR, and could be down regulated after treatment. Conclusion Polymorphism in TNFα gene promoter -308 is associated with onset of MG. The microsatellite allele TNFα2 confer risk for the development of MG in Chinese patients. MG patients have a higher inducible level of TNFα.

Kinetics of phytohemaglutinin-induced IFN-γ and TNF-a expression in peripheral blood mononuclear cells from patients with chronic hepatitis B after liver transplantation

AIM： To study the association between host immunity and hepatitis B virus （HBV） recurrence after liver transplantation. METHODS： Peripheral blood mononuclear cells （PBMC） were isolated from 40 patients with hepatitis B and underwent orthotopic liver transplantation （OLT） before and 2, 4, 8 wk after surgery. After being cultured in vitro for 72 h, the levels of INF-γ and TNF-α in culture supematants were detected with ELISA. At the same time, the quantities of HBV DNA in serum and PBMCs were measured by real time PCR. RESULTS： The levels of INF-γ and TNF-α in PBMC culture supernatants decreased before and 2, 4 wk after surgery in turns （INF-γ 155.52±72.32 ng/L vs 14.76±9.88 ng/L vs 13.22±10.35 ng/L, F= 6.946, P= 0.027〈0.05; TNF-α 80.839±46.75 ng/L vs18.59±17.29 ng/L vs9.758±7.96 ng/L, F= 22.61, P = 0.0001〈0.05）. The levels of INF-γ and TNF-α were higher in groups with phytohemagglutinin （PHA） than in those without PHA before surgery. However, the difference disappeared following OLT. Furthermore, INF-γ and TNF-α could not be detected in most patients at wk 4 and none at wk 8 after OLT. The HBV detection rate and virus load in PBMC before and 2, 4 wk after surgery were fluctuated （HBV detected rate： 51.4%, 13.3%, 50% respectively; HBV DNA： 3.55±0.674 log（10） copies/mL vs 3.00±0.329 log（10） copies/mL vs 4.608±1.344 log（10） copies/mL, F= 7.582, P= 0.002〈0.05）. HBV DNA in serum was 4.48±1.463 log（10） copies/mL before surgery and 〈 10^3 copies/mL after OLT except for one with 5.72×10^6 copies/mL 4 wk after OLT who was diagnosed as HBV recurrence. The levels of INF-γ and TNF-α were lower in patients with a high HBV load than in those with a low HBV load （HBV DNA detected/undetected in PBMCs： IFN-γ 138.08±72.44 ng/L vs 164.24±72.07 ng/L, t = 1.065, P= 0.297〉0.05, TNF-α 80.75±47.30 ng/L vs 74.10±49.70 ng/L, t= 0.407, P= 0.686〉 0.05; HBV DNA positive/negative： IFN-γ 136.77±70.04 ng/L vs 175.27±71.50 ng/L, t= 1.702, P= 0.097〉0.05; TNF-α 75.37±43.02 ng/L vs 81.53±52.46 ng/L, t = 0.402, P = 0.690〉0.05）. CONCLUSION： The yielding of INF-γ and TNF-α from PBMCs is inhibited significantly by immunosuppressive agents following OLT with HBV load increased, indicating that the impaired immunity of host is associated with HBV recurrence after OLT.

Screening, Identification and Fermentation Property of a Yeast Strain R6 Accumulating Alpha-ketoglutaric Acid

A yeast strain R6 was obtained by the method of thiamine（VB1） auxotrophic negative selection from the edible oil-polluted soil in Zibo, China. Physiological and biochemical experiments revealed that strain R6 shared common feature with Rhodotorula mucilaginosa according to the API 20 C AUX yeast identification system which has been tested previously. Furthermore, the 18 S r DNA gene of strain R6 was amplified and sequenced. Phylogenetic analysis based on the 18 S r DNA sequence and the relatives indicated that R6 shared 99% homologies with the members of R. mucilaginosa, suggesting that strain R6 belonged to R. mucilaginosa.Investigation showed that strain R6 possessed the capacity of accumulating exocellular alpha-ketoglutaric acid（alpha-KG）. Finally, the fermentation conditions of R6 to accumulate alpha-KG was optimized by controlling each single fermenting variable and detected through high performance liquid chromatography（HPLC）. Results showed that both VB1 and Ca CO3 in fermentation medium were the key factors influencing the cumulant of alpha-KG. The discovery of natural auxotrophic strain R6 not only broadened the microbial resource which can achieve lots of alpha-KG production through fermentation, but also laid a foundation for further fermentation regulation to achieve excessive alpha-KG accumulation.

Moxibustion inhibits interleukin-12 and tumor necrosis factor alpha and modulates intestinal flora in rat with ulcerative colitis

AIM: To investigate the effect of moxibustion on intestinal flora and release of interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) from the colon in rat with ulcerative colitis (UC). METHODS: A rat model of UC was established by local stimulation of the intestine with supernatant from colonic contents harvested from human UC patients. A total of 40 male Sprague-Dawley rats were randomly divided into the following groups: normal (sham), model (UC), herb-partition moxibustion (HPM-treated), and positive control sulfasalazine (SA-treated). Rats treated with HPM received HPM at acupuncture points ST25 and RN6, once a day for 15 min, for a total of 8 d. Rats in the SA group were perfused with SA twice a day for 8 d. The colonic histopathology was observed by hematoxylin-eosin. The levels of intestinal flora, including Bifidobacterium, Lactobacillus, Escherichia coli (E. coli), and Bacteroides fragilis (B. fragilis), were tested by real-time quantitative polymerase chain reaction to detect bacterial 16S rRNA/DNA in order to determine DNA copy numbers of each specific species. Immunohistochemical assays were used to observe the expression of TNF-α and IL-12 in the rat colons. RESULTS: HPM treatment inhibited immunopathology in colonic tissues of UC rats; the general morphological score and the immunopathological score were significantly decreased in the HPM and SA groups compared with the model group [3.5 (2.0-4.0), 3.0 (1.5-3.5) vs 6.0 (5.5-7.0), P < 0.05 for the general morphological score, and 3.00 (2.00-3.50), 3.00 (2.50-3.50) vs 5.00 (4.50-5.50), P < 0.01 for the immunopathological score]. As measured by DNA copy number, we found that Bifidobacterium and Lactobacillus, which are associated with a healthy colon, were significantly higher in the HPM and SA groups than in the model group (1.395 ± 1.339, 1.461 ± 1.152 vs 0.045 ± 0.036, P < 0.01 for Bifidobacterium, and 0.395 ± 0.325, 0.851 ± 0.651 vs 0.0015 ± 0.0014, P < 0.01 for Lactobacillus). On the other hand, E. coli and B. fragilis, which are associated with an inflamed colon, were significantly lower in the HPM and SA groups than in the model group (0.244 ± 0.107, 0.628 ± 0.257 vs 1.691 ± 0.683, P < 0.01 for E. coli, and 0.351 ± 0.181, 0.416 ± 0.329 vs 1.285 ± 1.039, P < 0.01 for B. fragilis). The expression of TNF-α and IL-12 was decreased after HPM and SA treatment as compared to UC model alone (4970.81 ± 959.78, 6635.45 ± 1135.16 vs 12333.81 ± 680.79, P < 0.01 for TNF-α, and 5528.75 ± 1245.72, 7477.38 ± 1259.16 vs 12550.29 ± 1973.30, P < 0.01 for IL-12). CONCLUSION: HPM treatment can regulate intestinal flora and inhibit the expression of TNF-α and IL-12 in the colon tissues of UC rats, indicating that HPM can improve colonic immune response.

Ionic Conduction and Fuel Cell Performance of Ba0.97Ce0.8Ho0.2O3-α Ceramic

The perovskite-type-oxide solid solution Ba0.97Ce0.8Ho0.2O3-α was prepared by high temperature solidstate reaction and its single-phase character was confirmed by X-ray diffraction. The ionic conduction of the sample was investigated using electrical methods at elevated temperatures, and the performance of the hydrogen-air fuel cell using the sample as solid electrolyte was measured, which were compared with those of BaCe0.8Ho0.2O3-α. In wet hydrogen, BaCe0.8Ho0.2O3-α almost exhibits pure protonic conduction at 600-1000℃, and its protonic transport number is 1 at 600-900 ℃ and 0.99 at 1000 ℃. Similarly, Ba0.97Ce9.8Ho0.2O3-α exhibits pure protonic conduction with the protonic transport number of 1 at 600- 700℃, but its protonic conduction is slightly lower than that of BaCe0.8Ho0.2O3-α, and the protonic transport number are 0.99-0.96 at 800-1000 ℃. In wet air, the two samples both show low protonic and oxide ionic conduction. For Ba0.97Ce0.8Ho0.2O3-α, the protonic and oxide ionic transport numbers are 0.01-0.11 and 0.30-0.31 respectively, and for BaCe0.8Ho0.2O3-α, 0.01-0.09 and 0.27-0.33 respectively. Ionic conductivities of Ba0.97Ce0.8Ho0.2O3-α are higher than those of BaCe0.8Ho0.2O3-α under wet hydrogen and wet air. The performance of the fuel cell using Ba0.97Ce0.8Ho0.2O3-α as solid electrolyte is better than that of BaCe0.8Ho0.2O3-α. At 1000 ℃, its maximum short-circuit current density and power output density are 465 mA/cm^2 and 112 mW/cm^2, respectively.

THE ASSOCIATION BETWEEN TUMOR NECROSIS FACTORαGENE POLYMORPHISM AND ASTHMA

Objective.In this study,we investigated the hypothesis that tumor necrosis factor(TNF)α-308gene polymorphism might be of the genetic predisposition to asthma and asthma phenotypes.Methods.TNFα-308gene polymorphism was genotyped in221random unrelated Northern Chinese population(comprising125asthmatics and96healthy controls)and52individuals from12asthmatic families with Han ethnic by using polymerase chain reaction(PCR)-restriction fragment length polymor-phism(RFLP).Methacholine(Mch)broncho-challenge test,bronchial reversibility test and lung function were underwent in all asthmatics.Results.TNFα-3082homozygosity was present at a significantly higher frequency in asthmatics than that in controls(20.8%vs11.4%,P<0.05,OR2.259),the TNF allele2was also higher in asthmatics compared with controls(0.42vs0.33,P<0.01).TNFα-3082homozygosity was an weak independent risk factor for asthma etiology(OR0.226,P<0.05).Moreover,patients carrying TNFα-3082homozy-gosity had less responsive to inhaledβ 2 -agonist in20minutes than patients carrying other two genotypes(24.1%vs29.5%vs38.8%,P<0.05).Linkage analysis didn’t support that TNFαgene was linked to asthma (Likelihood of odds,LOD<1)based on familial data.Conclusion These results suggest that TNFα-3082homozygosity may be of a component contribut-ing to the genetic predisposition to asthma ,and airway responsiveness toβ2 -agonist.

Photoluminescence behavior and visible light photocatalytic activity of ZnO,ZnO/ZnS and ZnO/ZnS/α-Fe_2O_3 nanocomposites

In order to achieve effective, economic, and easily achievable photocatalyst for the degradation of dye methyl orange（MeO）, ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanocomposites were prepared by simple chemical synthetic route in the aqueous medium. Phase, crystallinity, surface structure and surface behavior of the synthesized materials were determined by X-ray diffraction（XRD） and Brunauer-Emmett-Teller analysis（BET） techniques. XRD study established formation of good crystalline ZnO, ZnO/ZnS and ZnO/ZnS/α-Fe2O3 nanomaterials. By using intensity of constituent peaks in the XRD pattern, the compositions of nanocomposites were determined. From the BET analysis, the prepared materials show mesoporous behavior, type Ⅳ curves along with H4 hysteresis. The ZnO/ZnS/α-Fe2O3 composite shows the largest surface area among three materials. From the UV-visible spectra, the band gap energy of the materials was determined. Photoluminescence spectra（PL） were used to determine the emission behavior and surface defects in the materials. In PL spectra, the intensity of UV peak of ZnO/ZnS is lowered than that of ZnO while in case of ZnO/ZnS/α-Fe2O3, the intensity further decreased. The visible emission spectra of ZnO/ZnS increased compared with ZnO while in ZnO/ZnS/α-Fe2O3 it is further increased compared with ZnO/ZnS. The as-synthesized materials were used as photocatalysts for the degradation of dye MeO. The photo-degradation data revealed that the ZnO/ZnS/α-Fe2O3 is the best photocatalyst among three specimens for the degradation of dye MeO. The decrease of intensity of UV emission peak and the increase of intensity of visible emission cause the decrease of recombination of electrons and holes which are ultimately responsible for the highest photocatalytic activity of ZnO/ZnS/α-Fe2O3.