Magnetoelectric and converse magnetoelectric res ponses in TbxDy1-xFe2-y alloy ＆ Pb（Mg1/3Nb2/3）（1-x）TixO3 crystal laminated composites

Measured results of magnetoelectric （ME） and converse magnetoelectric （CME） effects of TbxDy1-xFe2-y/ Pb（Mg1/3Nb2/3）（1-x）TixO3/TbxDy1-xFe2-y （TD/PMNT/TD） and PMNT/TD/PMNT laminated composites are presented. ME effect was determined by measuring laminate voltage output under a Helmholtz-generated AC field biased by a DC field （0-1 kOe） （1Oe = 79.58 A/m）. The CME effect was measured by recording the voltage induced in a solenoid encompassing the ME sample while exposed to a DC bias field and PMNT layer driven by a 10 V AC source. The ME and CME responses in the two laminated structure are linear. The highest values of ME coefficients in TD/PMNT/TD and PMNT/TD/PMNT composites are 384 mV/Oe and 158 mV/Oe, respectively, while the highest values of CME coefficients in the two composites are 118 mG/V and 162 mG/V （1 G=10^-4 T）, respectively.     

Ubi1 intron-mediated enhancement of the expression of Bt cry1Ah gene in transgenic maize （Zea mays L.）

The cry1Ah gene was one of novel insecticidal genes cloned from Bacillus thuringiensis isolate BT8. Two plant expression vectors containing cry1Ah gene were constructed. The first intron of maize ubiqutinl gene was inserted between the maize Ubiquitin promoter and cry1Ah gene in one of the plant expressing vectors （pUUOAH）. The two vectors were introduced into maize immature embryonic calli by microprojectile bombardment, and the reproductively plants were acquired. PCR and Southern blot analysis showed that foreign genes had been integrated into maize genome and inherited to the next generation stably. The ELISA assay to T1 and T2 generation plants showed that the expression of CrylAh protein in the construct containing the ubil intron （pUUOAH） was 20% higher than that of the intronless construct （pUOAH）. Bioassay results showed that the transgenic maize harboring cry1Ah gene had high resistance to the Asian corn borers and the insecticidal activity of the transgenic maize containing the ubil intron was higher than that of the intronless construct. These results indicated that the maize ubil intron can enhance the expression of the Bt cry1Ah gene in transgenic maize efficiently     

C-H···Pd(II) interaction-driven homochiral M helix formation of neutral (R,R)-bis(pyrrol-2-ylmethyl- eneamino) cyclohexane palladium(II) complex

A chiral complex of (R,R)-Pd was prepared by reaction of optically pure (R,R)-bis(pyrrol-2-ylmethyl-eneamino) cyclohexane ligand with Pd(OAc)2·2H2O under the base condition at room temperature. The weak intermolecular C-H···Pd interaction was found to be responsible for the homochiral M helix for-mation of the neutral,chiral,mononuclear (R,R)-Pd in the crystal packing.     

Theoretic study of the reaction mechanism between （Me）3CO· radical and trans-3-hexene

The reaction mechanism between （Me）3CO· radical and trans-3-hexene in benzene was studied for the first time at the B3LYP/6-311＋＋G（d,p）//B3LYP/6-31G（d）＋ZPVE level. Two distinct elementary channels were identified as： （1） abstraction-addition; （2） addition-addition-elimination. Analysis of the potential energy surface demonstrates that for the title reaction, channels （1） and （2） have the major and minor contribution, respectively. Our calculated results can well explain the recently observed product distribution by Coseri et al. （J. Org. Chem. 2005, 70, 4629）. However, we found that the addition-abstraction channel proposed by Coseri et al. is kinetically infeasible.     

Microcalorimetric investigation of effect of berberine alkaloids from Coptis chinensis Franch on intestinal diagnostic flora growth

The inhibitory effect of three berberine alkaloids (BAs) from Coptis chinensis Franch, a traditional Chinese medicinal (TCM) herb, on Bifidobacterium adolescentis growth was investigated by microcalorimetry. The power-time curves of B. adolescentis with and without BAs were acquired, meanwhile the extent and duration of inhibitory effect on the metabolism were evaluated by the growth rate constant (k), half inhibitory ratio (IC₅₀), maximum heat-output power (P _max), peak time of maximum heat-output power (t _p) and total heat production (Q _t). k, P _max and Q _t decreased, and t _p was prolonged with the increase of BAs concentration. The IC₅₀ of BAs is 806 μg/mL for berberine, 341 μg/mL for coptisine and 236 μg/mL for palmatine. The sequence of antimicrobial activity of BAs is berberine < coptisine < palmatine. Combined with previous studies, it could be shown that the sequences of antimicrobial activity of BAs on both Bacillus shigae and Escherichia coli are berberine > coptisine > palmatine. The structure-function relationship of BAs indicates that the functional group methylenedioxy or methoxyl at C2 and C3 might be the major group inducing the activities of BAs on E. coli and B. adolescentis. Meanwhile, the substituent groups at C2, C3, C9 and C10 almost have equal effect on B. shigae. Supported by the National Natural Science Foundation of China (Grant Nos. 30625042 and 30873385) and Key Projects of National Science & Technology Pillar Program of China in the 11th Five-Year Period (Grant No. 2007BAI40B05)     

Diversity and high nitrogenase activity of endophytic diazotrophs isolated from Oryza rufipogon Griff.

Diversity and nitrogenase activity of endophytic diazotrophs colonized in the wild rice Oryza rufipogon Griff grown in Boluo, Huilai County in Guangdong Province and Lingshui County in Hainan Province were studied. Thirty-seven isolates obtained from Oryza rufipogon were identified as putative endophytic nitrogen-fixing bacteria by ARA （acetylene reduction assay） test and further confirmed by PCR amplification of nifH gene fragments. All obtained strains have ARA activity and the same sized nifH gene fragments. Above the similarity level of 80%, the obtained isolates were assigned as Group Ⅰ to Ⅷ by the clustering of IS-PCR fingerprints. The SDS-PAGE whole-cell protein patterns were similar to those of IS-PCR fingerprints. Components and contents of fatty acid methyl esters （FAMEs） were used to differentiate the representative strains （Ls13, Ls8, BL1, BL12, HL6, Ls4） from Group Ⅰ to Group Ⅵ. The six representative strains showed significant difference in contents and components of cellular fatty acid methyl ester. 16S rDNA sequencing analysis showed that strains of Group Ⅰ to Ⅶ were located in Enterobacteraceae （y-proteobacteria）. Strains of Group Ⅰ and Group Ⅱ were closely related to Klebsiella sp.; Strain Ls8 of Group Ⅱ was a little far away from the genus of Pantoea （homology level 96% with Pantoea agglomerans）, which may represent a new species or genus in Enterobacteraceae; Strains of Groups Ⅳ and Ⅴ belonged to different Enterobacter sp.; Strain Ls4 and Ls 9 representing Group Ⅵ were close to Citrobacter amalonaticus with 98% sequence similarity; Strain Ls15 of Group Ⅶ showed 98% sequence identity with Pantoea sp.; Strains of Group Ⅷ were assigned to the genus Ideonella （β-proteobacteria）. Based on the above results, endophytic diazotrophs isolated from O. rufipogon showed great diversity and some diazotrophs showed high nitrogenase activity with 42.52 μmol/mL. h C2H4. Inoculation to rice tests indicated that the isolated endophytic diazotrophs significantly promoted the rice growth.     

Decay dynamics of excited CS<Subscript>2</Subscript> and NH<Subscript>3</Subscript> investigated by femtosecond laser

By using the home-made femtosecond laser system and the time-of-flightmass spectrometer, the decay dynamics of excited carbon disulfide (CS2) and ammonia (NH3) are investigated in real time by pump-probe multiphoton ionization detection. The estimated lifetime constant of the NH3 state (514 fs) agreed quite well with the literature report. For the first time, the decay lifetime constants of the NH3 ′1A′1 state (93793 fs), the CS2 state (153 ± 10 fs), and the CS2 Rydberg state[2-3]6sσg(3Ⅱg)(948 ± 23 fs) are obtained.     

Inhibition of bromophenols against PTP1B and anti-hyperglycemic effect of <Emphasis Type="Italic">Rhodomela confervoides</Emphasis> extract in diabetic rats

Protein tyrosine phosphatase 1B （PTPIB） plays an important role as a negative regulator In insulin signaling pathways. PTPIB is an effective target for the treatment of type 2 diabetes mellitus. Four bromophenol derivatives from red algae Rhodomela confervoides, 2,2＇,3,3＇-tetrabromo-4,4＇,5,5＇-tetrahydroxydiphenyl methane （1）, 3-bormo-4,5-bis（2,3-dibromo-4,5-dihydroxybenzyl） pyrocatechol （2）, bis（2,3-dibromo-4,5-dihydroxybenzyl） ether （3） and 2,2＇,3-tribromo-3＇,4,4＇,5-tetrahydroxy-6＇-ethyloxymethyldiphenylmethane （4） showed significant inhibitory activity against PTPIB （IC50 were 2.4, 1.7, 1.5 and 0.84 μmol/L, respectively） as potential therapeutical agents for the treatment of type 2 diabetes mellitus. The anti-hyperglycemic effects of the ethanol extracts from If. confervoides on streptozotocin-induced diabetes （STZ-diabetes） in male Wistsr rats fed with high fat diet were investigated. The STZ-diabetic rats treated with medium-dose and high-dose alga extracts showed remarkable reductions in fasting blood glucose （FBG） as compared with the STZ-diabetic control. The results indicate that the in vivo anti-hyperglycemic activity of the R. confervoides extracts can be partially attributed to the inhibitory actions against PTPIB of the bromophenol derivatives and that may be of clinical Importance in improving the management of type 2 diabetes mellitus.     

Relaxor behavior of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 ceramics

n the present work, the phase transitions and relaxor behavior of (1−x)Pb(Mg_1/3Nb_2/3)O₃-xPbTiO₃ (PMN-PT, x = 0.2―0.4) ferroelectric ceramics have been investigated by means of X-ray diffraction, di-electric spectroscopy, the P-E hysteresis loop measurements and Raman scattering techniques. Structural analysis revealed that with the increase of PbTiO₃ content, PMN-PT ceramics experienced a gradual phase transition process from rhombohedral to tetragonal. It is usually believed that such kinds of phase transitions resulted in the linear decrease of relaxation degree. Surprisingly, our analy-sis of the dielectric spectra revealed that the indicator of the degree of diffuseness γ reached the maximum value near morphotropic phase boundary (MPB) (x = 0.32), then decreased with the further increase of PbTiO₃ content. The large dielectric relaxor feature near MPB may be attributed to the for-mation of ordered nanodomains, resulting from complex coexisting nanostructures. Further, the P-E hysteresis loop measurements and Raman analysis of the B-site cation order correlated well with the dielectric measurement results. It was found that the hysteresis loop squareness R_sq received the minimum value while the inverse of the value of full wide of half maximum (FWHM) of A_1g mode reached the maximum value at MPB composition, which showed similar trends to γ.     

High molecular weight (C35 +) n-alkanes of Neogene heavily biodegraded oil in the Qianmiqiao region, North China

With wax content of 1.62%, heavy oil has been produced from the sandstone reservoirs of Neogene Guantao Formation (Ng1^Ⅲ). In the GC and GC-MS RIC profiles of its aliphatic fraction, n-alkanes are totally lost, which shows the result of heavy biodegradedation. However, the remaining trace C₁₃－C₃₆ n-alkanes can be still seen from its m/z 85 mass chromatogram. In addition, a complete series of C₃₅－C₇₃ high molecular weight (HMW) n-alkanes was detected by high-temperature gas chromatography (HTGC). The HMW n-alkane series shows a normal distribution pattern, a major peak at nC₄₃, obvious odd-carbon-number predominance, CP_I37—55 and OEP_45—49 values up to 1.17 and 1.16—1.20 respectively. The present study not only has conformed the strong resistibility of HMW n-alkanes to biodegradation in crude oils as concluded by previous researchers, but also has provided some significant information on source input and maturity for the heavily biodegraded oil in the Qianmiqiao region.     

Research of Inclusion Complexation of 4,4＇-Thiodiphenol Effected by β-Cyclodextrin in Aqueous Solutions and the Effect on Photodegradation

The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.     

An <Emphasis Type="Italic">Arabidopsis ctpA</Emphasis> homologue is involved in the repair of photosystem II under high light

A T-DNA insertion mutant AtctpA1 was identified to study the physiological roles of a carboxyl-terminal processing protease （CtpA） homologue in Arabidopsis. Under normal growth conditions, disruption of AtctpA1 did not result in any apparent alterations in growth rate and thylakoid membrane protein components. However the mutant plants exhibited increased sensitivity to high irradiance. Degradation of PSII reaction center protein D1 was accelerated in the mutant during photoinhibition. These results demostrated that AtctpA1 was required for efficient repair of PSII in Arabidopsis under high irradiance.     

Rate constants for the reaction of ozone with <Emphasis Type="Italic">n</Emphasis>-butyl, <Emphasis Type="Italic">s</Emphasis>-butyl and <Emphasis Type="Italic">t</Emphasis>-butyl methyl sulfides

The rate constants for the ozone reactions with n-butyl methyl sulfide （n-BMS, CHaCH2CH2CH2SCH3）, sec-butyl methyl sulfide （s-BMS, CH3CH2（CH3）CHSCHa） and tert-butyl methyl sulfide （t-BMS, （CH3）3CSCH3） were measured using our smog chamber under supposedly pseudo-first-order conditions at 30002 K and 760 Torr. The experimental determined rate constants for n-butyl, s-butyl and t-butyl methyl sulfide are （1.23 ± 0.06）×10-19, （5.08 ± 0.19）×10-20 and （2.26 ± 0.14）×10-20 cm3 molecule-1· s-1, respectively. The reactivity-structure relationship of the reactions was discussed and used to illustrate the mechanism of the ozone reaction with thioethers. The results enrich the kinetics data of atmospheric chemistry.     

Effects of dietary nickel on detoxification enzyme activities in the midgut of <Emphasis Type="Italic">Spodoptera litura</Emphasis> Fabricius larvae

Nickel accumulated in midugt of Spodoptera litura Fabricius could induce the expression of metallothionein, one of the most important detoxification proteins in organisms. In the present study, the effects of dietary nickel on the activities of detoxification enzymes, such as carboxylesterase （CarE） and giutathione S-transferase （GST） in the midgut of S. litura larvae have been studied to get an understanding of the detoxification mechanisms of S. litura larvae to excessive nickel. Results showed that CarE activities in the midgut of the 5th instar larvae decreased at lower levels of nickel （≤5 mg/kg）, while increased with increasing nickel doses at higher levels of nickel （≥10 mg/kg） exposure in successive 3 generations. CarE activities of the 6th instar larvae were also characterized as inhibited at low levels of nickel exposure, and improved at higher levels in the 1st generation. CarE activities of 6th instar larvae in the 2nd and 3rd generations were all lower than that in control. However, GST activities in the midgut of the 5th and 6th instar larvae all increased with increasing nickel doses （1 --20 mg/kg） in diets.     

Studies of new EST-SSRs derived from Gossypium barbadense

Existing cotton EST-SSR markers are mostly derived from Gossypium arboreum and Gossypium hir-sutum, but EST-SSR markers from Gossypium barbadense are scarce. One hundred and nineteen EST-SSRs were developed based on 98 unique ESTs from a cDNA library constructed in our laboratory using developing fibers from G. barbadense cv. Pima3-79. Among the SSRs, trinucleotide AAG appeared at a high frequency of 11.76%. 36 accessions (consisting of 13 diploids of the A genome, 11 diploids of the D genome and 12 allotetraploids of the AD genome) were employed to test new EST-SSRs. 76 EST-SSRs were successfully amplified, and 313 polymorphic fragments were yielded, with an average of 4.11 fragments per primer pair. The PIC ranged from 0.17 to 0.95 with an average of 0.53. Based on Jaccard’s genetic similarity coefficient, these 36 accessions were clustered into three groups. 21 EST-SSRs exhibited polymorphisms in BC1 population ((Emian22 × Pima3-79) × Emian22), 24 polymor- phic loci were generated, while 22 of the 24 polymorphic loci were integrated with our interspecific BC1 backbone genetic linkage map, and anchored in 12 chromosomes. This study effectively proved that EST-SSRs from G. barbadense are valuable for genetic diversity analysis and genetic mapping.     

Development of Triticum aestivum-Leymus racemosus ditelosomic substitution line 7Lr#1S（7A） with resistance to wheat scab and its meiotic behavior analysis

Leymus racemosus is highly resistant to wheat scab （Fusarum head bright）. The transfer of scab resistant gene from L. racemosus to Triticum aestivum is of great significance for broadening the base of wheat resistance. In the present study, the pollen of T. aestivum-L, racemosus monosomic addition line with scab resistance was treated by irradiation with 1200 R ^60Co-γ-rays prior to pollinating to emasculated wheat cv. Mianyang 85-45. Nine plants with a telocentric chromosome 7Lr#1S were observed in M1, and one ditelosomic substitution line 7Lr#1S was selected from selfcrossing progenies and confirmed by chromosome C-banding and GISH. Furthermore, a co-dominant EST-SSR marker CINAU 31 was employed to identify this substitution line. A pair of chromosome 7A of common wheat were found to be replaced by a pair of telocentric chromosome 7Lr#1S, and further investigation showed that chromosome configuration of the substitution line at MI of PMCs after GISH was 17.50Ⅱ^w ＋ 2.19Ⅱ^w ＋ 0.42Ⅱ^7Lr#1S ＋ 1.08 Ⅰ^7Lr#1S ＋ 0.69 Ⅰ^w. Two telocentric chromosomes paired as a bivalent in 59.7% of PMCs. Abnormal chromosome behaviors of telocentric chromosomes were observed in part of PMCs at anaphase I and telophase I, including the moving of two telocentric chromosomes to the same pole, lagging and earlier separation of their sister chromatid. All these abnormal behaviors can be grouped into three distinct types of tetrads according to different numbers of 7Lr#1S in their daughter cells and various micronucleus in some tetrads. However, due to the high transmission frequency of the female and male gametes with a 7Lr#1S, 84% of the selfcrossing progeny plants had ditelosomic substitution. The substitution line showed high resistance to wheat scab in a successive two-year test both in the greenhouse and field; hence, the line will be particularly valuable for alien gene mapping, small fragment translocation induction and telosomic cytological behavior analysis.     

Photodegradation of <Emphasis Type="Italic">N</Emphasis>-nitrosodiethylamine in water with UV irradiation

The direct photolysis of N-nitrosodiethylamine （NDEA） in water with ultraviolet （UV） irradiation was investigated. Results showed that NDEA could be completely degraded under the direct UV irradiation. The effects of the experimental conditions, including the initial concentration of NDEA, humic acid and solution pH, were studied. The degradation products of NDEA were identified and quantified with gas chromatography-mass spectrometry （GC-MS） and high performance liquid chromatography （HPLC）. It was confirmed that methylamine （MA）, dimethylamine （DMA）, ethylamine （EA）, diethylamine （DEA）, NO2^- and NO3^- were the main degradation products. The photolysis degradation mechanism of NDEA was also discussed. As a result of N-N bond fission, NDEA was degraded by direct UV irradiation.     

Fine mapping of the red plant gene R1 in upland cotton(Gossypium hirsutum)

Sub 16 is a substitution line with G. hirsutum cv. TM-1 genetic background except that the 16th chromosome (Chr. 16) is replaced by the corresponding homozygous chromosome of G. barbadense cv. 3-79, and T586 is a G. hirsutum multiple gene marker line with 8 dominant mutation genes. The R ₁ gene for anthocyanin pigmentation was tagged in Chr. 16 in T586. The objective of this research was to screen SSR markers tightly linked with R ₁ by using the F₂ segregating population containing 1259 plants derived from the cross of Sub 16 and T586 and the backbone genetic linkage map from G. hirsutum×G. barbadense BC₁ newly updated by our laboratory. Genetic analysis suggested that the segregation ratio of red plants in the F₂ population fit Mendelian 1:2:1 inheritance, confirming that the red plant trait was controlled by an incomplete dominance gene. Preliminary mapping of R ₁ was conducted using 237 randomLy selected F₂ individuals and JoinMap v3.0 software. Then, a fine map of R1 was constructed using the F₂ segregating population containing 1259 plants, and R ₁ was located between NAU4956 and NAU6752, with only 0.49 cM to the nearest maker loci (NAU6752). These results provided a foundation for map-based cloning of R ₁ and further development of cotton cultivars with red fibers by transgenic technology. Supported by National Natural Science Foundation of China (Grant No. 30730067) and Programme of Introducing Talents of Discipline to Universities (Grant No. B08025)     

Reporter-based screen for <Emphasis Type="Italic">Arabidopsis</Emphasis> mutants compromised in nonhost resistance

Plants are exposed to many potentially pathogenic microbes in the environment, but each species is only susceptible to a limited number of pathogens. The broad resistance is referred to as nonhost resistance. To date, little is known about the underlying mechanism of nonhost resistance and the signaling transduction process. Here we describe a simple method for isolating Arabidopsis nonhost resistance mutants against a nonadapted bacterial pathogen. A RAP2.6 promoter-driven LUC reporter system was developed to replace the tedious bacterial growth assay during the primary screening. The RAP2.6-LUC reporter gene is normally induced by the virulent bacterium Pseudomonas syringae pv tomato but not the nonadapted bacterium P. syringae pv phaseolicola. By using this method we iso- lated 4 mutants displaying strong reporter activity in response to P. syringae pv phaseolicola, which were characterized in some details, ebsl, ebs2, ebs3, and ebs4 （enhanced bacterial susceptibility） were compromised in resistance against P. syringae pv phaseolicola and/or P. syringae pv tomato. In addition, ebs4 showed enhanced hypersensitive response to the incompatible bacterium P. syringae pv tomato （avrB）. These results demonstrated that the method is suited for large scale screening for nonhost resistance mutants.     

Evolution of the serum resistance-associated SRA gene in African trypanosomes

Serum resistance-associated (SRA) protein, a protein unique for Trypanosoma brucei rhodesiense, is responsible for resistance of this parasite to the lysis by normal human serum (NHS) and is a vital molecular marker to distinguish this species from other African trypanosomes. We cloned and sequenced the SRA basic copy (SRAbc) gene from T. b. rhodesiense and related species and found that this gene is confined to the subgenus Trypanozoon. The average 82% identity among the sequenced SRAbc genes indicates that they may have a common origin and are highly conserved. Since SRAbc coexists in the T. b. rhodesiense genome with SRA, we propose that SRAbc might be the ‘donor VSG’, which after duplication became inserted into the expression site by recombination. Under natural selection, SRAbc could reform into SRA following mosaic formation. Supported by National Natural Science Foundation of China (Grant Nos. 30570245, 30670275), Changjiang Scholars and Innovative Research Team in University (Grant No. DPCKSCU/IRT0447), International Foundation for Science of Sweden (Grant No. B/4318-1), Grant Agency of the Czech Republic (Grant No. Z60220518) and Education Foundation of the Czech Republic (Grant No. 2B06129)