黄瓜种质资源遗传亲缘关系的RAPD分析

利用ＲＡＰＤ技术对多个生态型的黄瓜材料的遗传亲缘关系进行了研究。从２００个１０碱基随机引物中筛选出２０个用于ＰＣＲ反应，３９．２％的扩增条带表现多态性；每个生态型品种都具有其特有的扩增（缺失）带以区别其他生态型品种；聚类分析将供试材料分为３大类群：华北类群、华南类群和欧洲温室类群。从分子水平验证了传统的黄瓜地域分类标准及黄瓜是遗传基础狭窄的蔬菜作物。对利用ＲＡＰＤ技术进行亲缘控制研究的可能性进行了探讨。

Assay and Evaluation of Flavonoid Content in Chinese Celery

Flavonoids were the most important secondary metabolites in celery （Apium graveolens L.）.In this study,the flavonoid （apigenin and luteolin） contents of leaves and petioles in 44 Chinese celery varieties,an American celery variety ‘Ventura＇ and an European celery variety ‘Princer＇ were assayed by reversed-phase high-perfor mance liquid chromatography （RP-HPLC）.The results showed that significant differences in the apigenin and luteolin contents of the leaves and petioles were found among 46 celery varieties,and the variation coefficients of leaf apigenin content,leaf luteolin content,leaf flavonoid content,petiole apigenin content,petiole luteolin content and petiole flavonoid content were 30％,10％,30％,20％,30％ and 20％,respectively.There was no correlation between the leaf flavonoid content and petiole flavonoid content.The apigenin content was about 18 to 50 times of luteolin in celery leaf and about 19 to 40 times of luteolin in celery petiole.The flavonoids in most of the Chinese celery varieties were higher than in ‘Ventura＇ and ‘Princer＇.The flavonoid contents of Chinese celery varieties from the Yangtze Valley and southern China were higher than those from northern China.Our results suggested that Chinese celery varieties with high petiole apigenin contents could be used for vegetable breeding because the petiole was the main edible part,and Chinese celery varieties with high leaf apigenin contents could be used for apigenin production.

Analysis of the Antimicrobial Activity of Antimicrobial Peptides Extracted from Immunized Tenebrio molitor Induced by Different Microbial Treatments Against 26 Pathogens

[Objective] The study was to explore whether antimicrobial activity of the antimicrobial peptides extracted from immunized Tenebrio molitor varied with different pathogens as inducers.[Method]By inducing T.molitor hungry larvaes to generate immune response via feeding with bacteria and with fungi or actinomycete post to pricking,the antimicrobial peptides extracts were obtained by grinding and centrifuging the cultures.Its antimicrobial activity against 26 pathogens was measured by bacteriostatic ring,and evaluated by trisection to four types and inhibitory spectrum.[Result]Both the antimicrobial activity and antimicrobial spectrum of the antimicrobial peptides extracts varied remarkably among different pathogens as inducers.[Conclusion]Bio-control used strains have obvious advantage in inducing the insect to express body fluid immunity material-antimicrobial peptides.

Stability of Baicalin Aqueous Solution by Validated RP-HPLC

Aim In the present study a RP-HPLC method was developed and validated toinvestigate the stability of baicalin aqueous solution. Methods The influences of temperature and pHon the stability of baicalin aqueous solution were investigated by classic homoiothermicacceleration test, and the pH for the most stable solution was determined. Results The time whenbaicalin suffered 10% loss was found to be 18.1 h, and the degradation activation energy of baicalinwas 79.1 kJ·moL^(-1) . The pH at which baicalin is most stable is 4.28. Conclusion The temperatureshould be kept at a lower level and the pH should be adjusted to near that for the most stablesolution in the production of baicalin preparations.

Simulation of the Photosynthetic Reaction Center with an Artificial Solar Cell Reaction to Generate Triplet Molecule via Charge Recombination

The formation of triplet chlorophyll and carotenoid by radical pair recombination have been observed in the reaction centers of photosystems of bacteria and higher plants. This is an important process for the photoprotection of the reaction centers, for the dissipation of excessive energy by non_radiative decay of carotenoid triplet. Triplet generation by the same mechanism in an artificial system has rarely been observed, only a few cases were reported in donor_acceptor triad supermolecules. This is probably the first time report of the simulation of the generation of triplet by back electron transfer using dye_sensitized TiO 2 solar cell reaction. Triplet states have been observed in all_ trans _retinoic acid sensitized TiO 2 colloid during the recombination of the trapped electron with the retinoic acid radical cation after photoexcitation. The intermediates were characterized by ns time_resolved spectroscopy.

Effect of rhubarb on contractile response of gallbladder smooth muscle strips isolated from guinea pigs

AIM: To investigate the effect of rhubarb on contractile response of isolated gallbladder muscle strips from guinea pigs and its mechanism.METHODS: Guinea pigs were killed to remove the whole gallbladder. Two or three smooth muscle strips (8 mm×3mm) were cut along the longitudinal direction. The mucosa on each strip was carefully removed. Each longitudinal muscle strip was suspended in a tissue chamber containing 5 mL Krebs solution (37 ℃), bubbled continuously with 950 mL/L O2 and 50 mL/L CO2. The resting tension (g), mean contractile amplitude (mm),and contractile frequency (waves/min) were simultaneously recorded on recorders. After 2-h equilibration, rhubarb (10, 20, 70, 200, 700, 1 000 g/L) was added cumulatively to the tissue chamber in turns every 2 min to observe their effects on gallbladder.Antagonists were given 3 min before administration of rhubarb to investigate the possible mechanism.RESULTS: Rhubarb increased the resting tension (from 0 to 0.40±0.02, P＜0.001), and decreased the mean contractile amplitude (from 5.22±0.71 to 2.73±0.41,P＜0.001). It also increased the contractile frequency of the gallbladder muscle strips in guinea pigs (from 4.09±0.46to 6.08±0.35, P＜0.001). The stimulation of rhubarb on the resting tension decreased from 3.98±0.22 to 1.58±0.12by atropine (P＜0.001), from3.98±0.22 to 2.09±0.19 by verapamil (P＜0.001) and from 3.98±0.22 to 2.67±0.43by phentolamine (P＜0.005). But the effect was not inhibited by hexamethonium (P＞0.05). In addition, the action of mean amplitude and frequency was not inhibited by the above antagonists.CONCLUSION: Rhubarb can stimulate the motility of isolated gallbladder muscle strips from guinea pigs. The stimulation of rhubarb might be relevant with M receptor,Ca2+ channel and α receptor partly.

Evidences for involvement of endogenous cAMP in Arabidopsis defense responses to Verticillium toxins

Although there were reports suggesting the involvement of endogenous cAMP in plant defense signaling cascades, there is no direct evidence supporting this notion yet and the detailed mechanism is unclear. In the present study, we have used pathogenic fungi Verticillium dahliae and Arabidopsis plants as a model system of plant-microb interaction to demonstrate the function of endogenous cAMP in Arabidopsis defense responses. Both V. dahliae inoculation and Verticillium toxins injection induced typical “wilt” symptoms in Arabidopsis seedlings. When either 8-Br-AMP (a membrane permeable cAMP analogue) or salicylic acid (SA) was applied to Arabidopsis, the plants became resistant to V. dahliae toxins. However, addition of 8-Br-AMP did not increase the resistance of Arabidopsis transgenic plants deficient in SA to the toxins, suggesting that cAMP might act upstream of SA in plant defense signaling pathway. Indeed, 8-Br-cAMP and forskolin, an activator of adenylyl cyclase, significantly stimulated the endogenous SA level in plants, whereas DDA, an inhibitor of adenylyl cyclase dramatically reduced toxin-induced SA increase. Both the endog- enous cAMP and SA increased significantly in Arabidopsis seedlings treated with toxins. Furthermore, transcription level of pathogenesis-related protein 1 gene (PR1) was strongly induced by both 8-Br-cAMP and the toxin treatment. Taken together, our data demonstrate that endogenous cAMP is involved in plant defense responses against Verticillium- secreted toxins by regulating the production of the known signal SA in plant defense pathway.

Differentiation of xanthomonads causing the bacterial leaf spot of poinsettia in China from the pathotype strain of Xanthomonas axonopodis pv. poinsettiicola

In October 2003, a new bacterial disease with symptoms similar to those caused by Xanthomonas axonopodis pv. poinsettiicola was observed on poinsettia leaves at a flower nursery in Zhejiang Province of China. Three Xanthomonas strains were isolated from infected plants and classified as X. axonopodis. They were differentiated from the pathotype strain LMG849 of X. axonopodis pv. poinsettiicola causing bacterial leaf spot of poinsettia by comparison of pathogenicity, substrate utilization and BOX-PCR genomic fingerprints.

Interfacial reactions of chalcopyrite in ammonia–ammonium chloride solution

The interfacial reactions of chalcopyrite in ammonia–ammonium chloride solution were investigated.The chalcopyrite surface was examined by scanning electron microscopy and X-ray photoelectron spectroscopy(XPS)techniques.It was found that interfacial passivation layers of chalcopyrite were formed from an iron oxide layer on top of a copper sulfide layer overlaying the bulk chalcopyrite,whereas CuFe1-xS2 or copper sulfides were formed via the preferential dissolution of Fe.The copper sulfide layer formed a new passivation layer,whereas the iron oxide layer peeled off spontaneously and partially from the chalcopyrite surface.The state of the copper sulfide layer was discussed after being deduced from the appearance of S2-,S22-,Sn2-,S0 and SO42-.A mechanism for the oxidation and passivation of chalcopyrite under different pH values and redox potentials was proposed.Accordingly,a model of the interfacial reaction on the chalcopyrite surface was constructed using a three-step reaction pathway,which demonstrated the formation and transformation of passivation layers under the present experimental conditions.

Simultaneous separation and determination of four main isoflavonoids in Astragali Radix by an isocratic LC/ESI-MS method

A simple, reliable and rapid isocratic liquid chromatography(LC)-mass spectrometric detection(MS) coupled with electrospray ionization(ESI) method for simultaneous separation and determination of calycosin-7-O-β-D-glucoside, ononin, calycosin and formonometin in Astragali Radix was developed. After the samples were extracted with ethanol, the optimum separation conditions for these analytes were achieved using water and acetonitrile(70:30, v/v) containing 0.2%(v/v) acetic acid as a mobile phase and a 2.0 mm×150 mm Hypersil-Keystone C18 column. Selective ion monitoring(SIM) mode and [M+H]+ ions at m/z 447, 431, 285 and 269 were used for quantitative analysis of four main active components above mentioned. The calibration curves were linear in the range of 0.4-175.0 μg/mL for calycosin-7-O-β-D-glucoside, 0.2-146.0 μg/m L for ononin, 0.4-210.0 μg/mL for calycosin and 0.5-217.0 μg/mL for formonetion, respectively. The limits of quantification(LOQ) and detection(LOD) were 0.4 μg/mL and 0.08 μg/m L for calycosin-7-O-β-D-glucoside, 0.2 μg/mL and 0.06 μg/m L for ononin, 0.4 μg/mL and 0.1 μg/mL for calycosin, 0.5 μg/m L and 0.1 μg/m L formonetion, respectively. The standard recoveries were in the range of 96.5%-104.7%. The developed method has successfully been used for the determination of four main flavonoids in Astragali Radix from various sources and can be used for identification, differentiation and quality evaluation of Astragali Radix.

Determination of Formation Constants of Co￣(2+), Ni￣(2+),Cu￣(2+) and Zn￣(2+) Complexes with Humic and Fulvic Acidsby Potentiometric Titration Method

The formation constants of Co￣(2+), Ni￣(2+), Cu￣(2+) and Zn￣(2+) complexes with humic acid (HA) and fulvicacid (FA) in red soil were determined by the potentiometric titration method. The constants as a functionof composition of the complexation solutions were obtained by two graphical approaches respectively Theformation constants decreased with increasing concentration of metal in the solution. The results provideunambiguous evidence for the heterogeneity of the function groups of humic substances. The formationconstants of FA were much smaller than those of HA, and the formation constants of Cu￣(2+) were muchgreater than those of Co￣(2+) , Ni￣(2+) and Zn￣(2+) . The potentiometric titration method for determining formationconstants are also discussed in the article.

Remote Sensing Retrieval of Surface Suspended Sediment Concentration in the Yellow River Estuary

Accurate assessment of surface suspended sediment concentration （SSSC） in estuary is essential to address several important issues： erosion, water pollution, human health risks, etc. In this study, an empirical cubic retrieval model was developed for the retrieval of SSSC from Yellow River Estuary. Based on sediments and seawater collected from the Yellow River and southeastern Laizhou Bay, SSSC conditions were reproduced in the laboratory at increasing concentrations within a range common to field observations. Continu- ous spectrum measurements of the various SSSCs ranging from 1 to 5700 mg/1 were carried out using an AvaField-3 spectrometer. The results indicated the good correlation between water SSSC and spectral reflectance （Rrs） was obtained in the spectral range of 726-900 nm. At SSSC greater than 2700 mg/L, the 740-900 nm spectral range was less susceptible to the effects of spectral reflectance saturation and more suitable for retrieval of high sediment concentrations. The best correlations were obtained for the reflectance ratio of 820 nm to 490 nm. Informed by the correlation between Rrs and SSSC, a retrieval model was developed （R2 = 0.992）. The novel cubic model, which used the ratio of a near-infrared （NIR） band （740-900 nm） to a visible band （400-600 nm） as factors, provided robust quantifica- tion of high SSSC water samples. Two high SSSC centers, with an order of 103 mg/1, were found in the inversion results around the abandoned Diaokou River mouth, the present Yellow River mouth to the abandoned Qingshuigou River mouth. There was little sedi- ment exchange between the two high SSSC centers due to the directions of the residual currents and vertical mixing.

Parameter optimization of gravity density inversion based on correlation searching and the golden section algorithm

For density inversion of gravity anomaly data, once the inversion method is determined, the main factors affecting the inversion result are the inversion parameters and subdivision scheme. A set of reasonable inversion parameters and subdivision scheme can, not only improve the inversion process efficiency, but also ensure inversion result accuracy. The gravity inversion method based on correlation searching and the golden section algorithm is an effective potential field inversion method. It can be used to invert 2D and 3D physical properties with potential data observed on flat or rough surfaces. In this paper, we introduce in detail the density inversion principles based on correlation searching and the golden section algorithm. Considering that the gold section algorithm is not globally optimized. we present a heuristic method to ensure the inversion result is globally optimized. With a series of model tests, we systematically compare and analyze the inversion result efficiency and accuracy with different parameters. Based on the model test results, we conclude the selection principles for each inversion parameter with which the inversion accuracy can be obviously improved.

Interfacial interaction of bio-leaching of pyrite mineral

Electrokinetic and contact angle measurements were used to discuss the interfacial interaction on bio-leaching of pyrite mineral. Surface energy parameters of pyrite mineral and thiobacillus ferrooxidans were obtained by calculating according to formula of Young＇s equation and contact angle measurements. The results show that surface energy of thiobacillus ferrooxidans is much higher than that of pyrite mineral, and the reaction of pyrite mineral with thiobacillus ferrooxidans causes the reduction of the pyrite surface energy. The interfacial interaction energies between pyrite mineral and thiobaciUus ferrooxidans were also obtained based on polar interfacial interaction theory and electrokinetic and contact angle measurements. The thermodynamics approach only considering Lifshitz-van der Waals and Lewis acid-base interaction fails to explain the adhesion behavior of the bacteria, but the extended Derjaguin-Landan-Verwey-Overbeek theory concerning Lifshitz-van der Waals and Lewis acid-base and the electrostatic can exactly predict interfacial interaction.

Isolation and Characterization of a Phytotoxin from Xanthomonas campestris pv. retroflexus

A phytotoxin from Xanthomonas campestris pv. retroflexus was isolated using a chromatographer and HPLC, and the components were identified to be a mixture of minor molecular compounds including organic acids and cyclo-（proline-phenylalanine）. The greenhouse cultivation test was used to determine the influence of the isolated fractions on the growth of target weed redroot pigweed （Amaranthus retroflexus L）. The experimental results demonstrated that the cyclo-（Pro-Phe） had the weed inhibit activity obviously on dicotyledonous weed and the mixture with six organic acids showed stronger bioactivity. Further, greenhouse and field test were processed, and the test showed that the use of the toxin appeared to have the potential to be developed further as a bioherbicide system to control weedy grasses.

High performance ORR electrocatalysts prepared via one-step pyrolysis of riboflavin

Efficient,cost‐effective electrocatalysts for an oxygen reduction reaction(ORR)are currently required for fuel cells.In the present work,riboflavin was used as a cheap,nontoxic carbon and nitrogen precursor to prepare Fe-N-C catalysts via one‐step pyrolysis in the presence of anhydrous iron chloride.Raman spectroscopy indicated that the catalyst containing nitrogen created a great quantity of defects in the carbon structures,while nitrogen adsorption‐desorption isotherms showed that the catalyst was mesoporous.Transmission electron microscopy demonstrated that the Fe-N-C catalyst was composed of very thin,curved and porous graphene layers together with some Fe2O3nanoparticles,and X‐ray diffraction patterns confirmed that the carbon in the catalyst was highly graphitized.X‐ray photoelectron spectroscopy indicated that the active sites for the ORR were primarily composed of graphitic nitrogen,although Fe sites also played an important role.The ORR activity of the Fe-N-C catalyst reached a maximum of4.16mA cm-2,and its chronoamperometric response was found to decrease by only3%after operating for3h at0.66V(vs RHE)in an O2‐saturated0.1mol L-1KOH solution.In contrast,a commercial40wt%Pt/C catalyst with a loading of0.2mgPt cm-2exhibited an activity of4.46mA cm-2and a40%loss of response.The electrochemical performance of this new Fe-N-C catalyst was therefore comparable to that of the Pt/C catalyst while showing significantly better stability.

Gene cloning and induced expression pattern of IRF4 and IRF10 in the Asian swamp eel(Monopterus albus)

The Asian swamp eel （Monopterus albus） is one of the most economically important freshwater fish in East Asia, but data on the immune genes of M. albus are scarce compared to other commercially important fish. A better understanding of the eel＇s immune responses may help in developing strategies for disease management, potentially improving yields and mitigating losses. In mammals, interferon regulatory factors （IRFs） play a vital role in both the innate and adaptive immune system; though among teleosts IRF4 and IRFIO have seldom been studied. In this study, we characterized IRF4 and IRFIO from M. albus （malRF4 and malRFlO） and found that malRF4 cDNA consists of 1 716 nucleotides encoding a 451 amino acid （aa） protein, while malRFlO consists of 1 744 nucleotides including an open reading frame （ORF） of 1 236 nt encoding 411 aa. The malRFlO gene was constitutively expressed at high levels in a variety of tissues, while malRF4 showed a very limited expression pattern. Expression of malRF4 and malRFlO in head kidney, and spleen tissues was significantly up-regulated from 12 h to 48 h post-stimulation with polyinosinic： polycytidylic acid （poly I：C）, lipopolysaccharide （LPS） and a common pathogenic bacteria Aeromonas hydrophila. These results suggest that IRF4 and IRF10 play roles in immune responses to both viral and bacterial infections in M. albus.

Gene expression alteration during redox-dependent enhancement of arsenic cytotoxicity by emodin in HeLa cells

Emodin (1,3,8-trihydroxy-6-methylanthraquinone) could enhance the sensitivity of tumor cells to arsenic trioxide(As2O3)–induced apoptosis via generation of ROS, but the molecular mechanism has not been elucidated. Here, wecarried out cDNA microarray-based global transcription profiling of HeLa cells in response to As2O3/emodin cotreatment,comparing with As2O3–only treatment. The results showed that the expression of a number of genes was substantiallyaltered at two time points. These genes are involved in different aspects of cell function. In addition to redox regulationand apoptosis, ROS affect genes encoding proteins associated with cell signaling, organelle functions, cell cycle,cytoskeleton, etc. These data suggest that based on the cytotoxicity of As2O3, emodin mobilize every genomic resourcethrough which the As2O3–induced apoptosis is facilitated.

Effects of Water Regime and Reaction of Soil on Properties of Newly-Formed Humic Substances

The effects of soil water regime and soil reaction on nitrogen distribution and fractional composition of newly-formed humus (decayed products) and the structural characteristics of the newly-formed humic acids (HAs) were studied in an incubation experiment, with the following results obtained:1. The humus newly formed under submerged conditions was higher in the relative content of α-amino acid-N and the humic acid/ fulvic acid (HA/ FA) ratio than that under upland conditions. The HAs extracted from the former were also higher in C / O ratio, aromaticity and the contents of methoxyl groups and lignin-like components, but lower in the content of carboxyl groups than the HAs from the latter.2. Under upland conditions, the C / organic N ratio and the relative content of mobile HA of newly-formed humus were lower, but the HA / FA ratio was higher in the CaCO3-amended treatment than in non-amended treatment. The presence of CaCO3 also resulted in a decrease of C / N ratio of HA and a slight increase of its carboxyl group content. On the other hand, there was no significant change in the composition and properties of the newly-formed humus with the addition of CaCO3 under submerged conditions.3. Compared with soil HAs, the newly-formed HAs contained more carbohydrates, polypeptides and lignin-like components, and were in lower degrees of oxidation and humification.

Adjusting CA19-9 values to predict malignancy in obstructive jaundice:Influence of bilirubin and C-reactive protein

AIM:To find a possible relationship between inflammation and CA19-9 tumor marker by analyzing data from patients with benign jaundice(BJ) and malignant jaundice(MJ).METHODS:All patients admitted for obstructive jaundice,in the period 2005-2009,were prospectively enrolled in the study,obtaining a total of 102 patients.On admission,all patients underwent complete standard blood test examinations including C-reactive protein(CRP),bilirubin,CA19-9.Patients were considered eligible for the study when they presented obstructive jaundice confirmed by instrumental examinations and increased serum bilirubin levels(total bilirubin > 2.0 mg/dL).The standard cut-off level for CA19-9 was 32 U/mL,whereas for CRP this was 1.5 mg/L.The CA19-9 level was adjusted by dividing it by the value of serum bilirubin or by the CRP value.The patients were divided into 2 groups,MJ and BJ,and after the adjustment a comparison between the 2 groups of patients was performed.Sensitivity,specificity and positive predictive values were calculated before and after the adjustment.RESULTS:Of the 102 patients,51 were affected by BJ and 51 by MJ.Pathologic CA19-9 levels were found in 71.7% of the patients.In the group of 51 BJ patients there were 29(56.9%) males and 22(43.1%) females with a median age of 66 years(range 24-96 years),whereas in the MJ group there were 24(47%) males and 27(53%) females,with a mean age of 70 years(range 30-92 years).Pathologic CA19-9 serum level was found in 82.3% of MJ.CRP levels were pathologic in 66.6% of the patients with BJ and in 49% with MJ.Bilirubin and CA19-9 average levels were significantly higher in MJ compared with BJ(P = 0.000 and P = 0.02),while the CRP level was significantly higher in BJ(P = 0.000).Considering a CA19-9 cut-off level of 32 U/mL,82.3% in the MJ group and 54.9% in the BJ group were positive for CA19-9(P = 0.002).A CA19-9 cut-off of 100 U/mL increases the difference between the two groups:35.3% in BJ and 68.6% in MJ(P = 0.0007).Adjusting the CA19-9 value by dividing it by serum bilirubin level meant that 21.5% in the BJ and 49% in the MJ group remained with a positive CA19-9 value(P = 0.003),while adjusting the CA19-9 value by dividing it by serum CRP value meant that 31.4% in the BJ group and 76.5% in the MJ group still had a positive CA19-9 value(P = 0.000004).Sensitivity,specificity,positive predictive values of CA19-9 > 32 U/mL were 82.3%,45% and 59.1%;when the cutoff was CA19-9 > 100 U/mL they were,respectively,68.6%,64.7% and 66%.When the CA19-9 value was adjusted by dividing it by the bilirubin or CRP values,these became 49%,78.4%,69.4% and 76.5%,68.6%,70.9%,respectively.CONCLUSION:The present study proposes CRP as a new and useful correction factor to improve the diag-nostic value of the CA19-9 tumor marker in patients with cholestatic jaundice.