蓝藻Anabaena sp.PCC7120羧体碳酸酐酶的鉴定

在丝状蓝藻AnabaenaspPCC7120细胞租提液的碳酸酥酶（CA）分析中，发现了两种形式的CA活性．高CO2下生长的细胞，在35pmol／LEZ（Ethoxyzoamide，碳酸醉酶的抑制剂）存在的情况下，CA总活性的85％左右被抑制，其半抑制浓度I50为7.4μmol／L；随着EZ浓度的继续增加，CA活性在EZ浓度达到约150μmol／L处出现了第二个抑制峰，在250μmol／L处抑制程度达到最大，使CA总活性的15％被抑制，其半抑制浓度I50为190μmol／L．在空气条件下生长的细胞中也出现了CA的两个抑制峰：低I50为6μmol／L，高I50为120μmol／L．对核体的分离及体外测试表明，在波体制备物中的CA活性只有一个EZ的抑制峰，而且在EZ浓度达到35μmol／L，正如所期望的那样，该CA活性全部被抑制．其半抑制浓度150为5．2μmol／L左右．这个值跟空气或高CO2条件下生长的细胞粗提物中的低I50（6μmol／L或7．4μmol／L）十分相似．说明低浓度的EZ可以特异性地抑制定位于校体的CA活性．另外一种形式的CA，具有高I50（120－190μmol／L），约占CA总活性的15－20％，则有可能定位于细胞质膜．

蓝藻浓缩二氧化碳的机制

综述了蓝藻的CO2 浓缩机制研究进展 ,并简要介绍了一些重要的研究手段。

Transition metal coordination polymers with flexible dicarboxylate ligand:Synthesis,characterization,and photoluminescence property

Under solvothermal conditions,six new coordination polymers(CPs)[Mn(L)(phen)(H_(2)O)]_(n)(1),[Co(L)(phen)(H_(2)O)]_(n)(2),[Cu(L)(phen)(H_(2)O)]_(n)(3),[Zn_(2)(L)_(2)(phen)2(H_(2)O)]_(n)(4),[Zn(L)(phen)]_(n)(5),and[Cd(L)(phen)2]_(n)(6)were synthesized by reactions of dicarboxylate ligand 2,2'-(1,2-phenylenebis(methylene))bis(sulfanediyl)dinobutyric acid(H_(2)L)and 1,10-phenanthroline(phen)with the corresponding metal salts.Complexes 1-6 have been structurally characterized by single-crystal X-ray diffraction analyses,elemental analysis,IR,thermogravimetric analysis,and powder X-ray diffraction.The structures of 1-6 are 1D chains,which are further connected by hydrogen bonding interac-tions to form 3D supramolecular structures.Among them,1 and 2 are isomorphic with L2-of syn-conformation,while L2-shows anti-conformation in 3-6.In addition,the solid-state photoluminescence property of 4-6 was investigated.

Syntheses,structures,and properties of three coordination polymers based on 5⁃ethylpyridine⁃2,3⁃dicarboxylic acid and N⁃containing ligands

Three coordination polymers[Mn(epda)(2,2'⁃bipy)(H_(2)O)](1),[Mn(epda)(phen)](2),and[Co_(2)(epda)2(bpe)2(H_(2)O)_(4)]·5H_(2)O(3)(H2epda=5⁃ethyl⁃pyridine⁃2,3⁃dicarboxylic acid,2,2'⁃bipy=2,2'⁃bipyridine,phen=phenanthroline,bpe=1,2⁃bis(4⁃pyridyl)ethylene)were synthesized by solvothermal reactions and characterized by single⁃crystal X⁃ray diffraction,thermogravimetric analyses,IR spectroscopy and elemental analysis.1 displays a 1D chain struc⁃ture,and these chains are joined by O-H…O hydrogen bonding andπ⁃πstacking interactions to generate a 2D layer structure.2 displays a 2D layer structure,and adjacent layers are generated 3D architecture throughπ⁃πstacking interactions.3 displays a 1D chain structure,and adjacent chains are generated double layer structure through O-H…O hydrogen bonding.The fluorescent properties of 1 and 3 indicate that they can potentially be used as a luminescent sensor.1 was highly selective and sensitive towards o⁃nitrophenol through different detection mechanisms,however,3 was highly selective and sensitive towards 2,4,6⁃trinitrophenol.In addition,the magnetic behavior of 2 has also been investigated.CCDC:2172533,1,2355773,2,2355774,3.

Selection and Ultrastructural Observation of a High-CO_2-requiring Mutant of Cyanobacterium Synechococcus sp. PCC7942

A high_CO 2_requiring mutant of Synechococcus sp. PCC7942 has been isolated after chemical mutagenesis of ethyl methane sulphonate (EMS). It was able to grow at 4% CO 2, but not under ambient CO 2. The initial screening of the mutant showed that the genetic reversion rate was about 10 -7 and death occurred 2-3 days after being transferred from 4% CO 2 to the ambient air. Its photosynthetic dependence on external dissolved inorganic carbon was higher than that of the wild type cells, but its carbonic anhydrase activity was comparatively low. In the ultrastructural level, various types of aberrant carboxysomes appeared in the mutant cells: rod_shaped carboxysomes, irregular carboxysomes and the “empty_inclusion carboxysomes" with increasing number of glycogen granules surrounding the thylakoids. All these alterations indicated that the mutant was defective in utilizing the external CO 2. The induction of carboxysomes by lower levels of CO 2 and the biogenesis of carboxysomes are herein discussed.

旋覆代赭汤对胃动力低下大鼠胃窦组织中5-羟色胺胺前体和脱羧细胞的影响

[目的]观察旋覆代赭汤对胃动力低下大鼠胃窦组织中5-羟色胺胺前体和脱羧(5-HT APUD)细胞的数目、面积及平均灰度值的影响。[方法]将70只大鼠随机分为正常组和模型组,正常组10只,模型组60只。模型组每只大鼠按10g/kg的甘草煎剂灌胃造模,3d后随机分为模型3d组,模型7d组,旋覆代赭汤低、中、高剂量组及多潘立酮组,每组10只。多潘立酮予0.27mg/ml的多潘立酮混悬液灌胃,中药低、中、高剂量组分别予浓度为0.369、0.738、1.476g/ml的旋覆代赭汤灌胃,正常组和模型7d组给予等体积的0.85%氯化钠灌胃,共给药5d。用免疫组化法观测各组大鼠胃窦组织中5-HT APUD细胞的数目、面积及平均灰度值。[结果]一定剂量的甘草煎剂能明显减少大鼠胃窦组织中的5-HT APUD细胞数目及面积,增加平均灰度值;旋覆代赭汤中、高剂量组可以使胃动力低下大鼠胃窦组织中5-HT APUD细胞数目及面积明显增加,同时能使胃动力低下大鼠胃窦组织中5-HTAPUD细胞的平均灰度值降低(P<0.05或<0.01)。[结论]旋覆代赭汤促胃动力的作用机制之一可能是通过增加胃动力低下大鼠胃窦组织中5-HT APUD细胞数目而实现的。

Microwave-Assisted Decarboxylation of Sodium Oleate and Renewable Hydrocarbon Fuel Production

The carboxyl terminal of sodium oleate has a stronger polarity than that of oleic acid;this terminal is more likely to be dipole polarized and ionically conductive in a microwave field.Sodium oleate was used as the model compound to study the decarboxylation of oleic acid leading to hydrocarbon formation via microwave-assisted pyrolysis technology.The pyrolysis gas,liquid,and solid products were precisely analyzed to deduce the mechanism for decarboxylation of sodium oleate.Microwave energy was able to selectively heat the carboxyl terminal of sodium oleate.During decarboxylation,the double bond in the long hydrocarbon chain formed a p-πconjugated system with the carbanion intermediate.The resulting p-πconjugated system was more stable and beneficial to the pyrolysis reaction(decarboxylation,terminal allylation,isomerization,and aromatization).The physical properties of pyrolysis liquid were generally similar to those of diesel fuel,thereby demonstrating the possible use of microwaves for controlling the decarboxylation of sodium oleate in order to manufacture renewable hydrocarbon fuels.

Synthesis and Structural Characterization of Mononuclear Mn^(II) Picolilato Complex Mn(2-C_5H_4NCOO)_2(H_2O)_2.1/2CH_3CN

A Mn(II) picolilato complex Mn(2-C5H4NCOO)2(H2O)2?/2CH3CN 1 has been synthesized. Crystal of 1 is of monoclinic, space group C2/c with a = 25.6613(3), b = 8.6357(2), c = 16.8286(2) ? b = 122.835(1), V = 3133.47(9) ?, Mr=355.7, Dc = 1.508 g/cm3, F(000) = 1456, m = 0.874 cm1 and Z = 8. The final refinement gave R = 0.0362 and wR = 0.1096 for 2264 reflections (I > 2s(I)). The Mn(II) atom possesses distorted octahedral coordination geometry and the structural parameters around the Mn ion are close to those of other Mn analogues. Extensive hydrogen bonding interactions between carboxylate and H2O were observed making one-dimensional chains of the Mn monomers.

Water blocking effect caused by the use of hydraulic methods for permeability enhancement in coal seams and methods for its removal

To research techniques for removing the water blocking effect caused by hydraulic applications in coal seams,the use of surfactants is proposed,based on the mechanics of the water blocking effect.Centrifugal experiments were used to validate the effects of using surfactants;the results show that after dealing with vacuum saturation with water,the volume of micropores decreases,which results in a larger average pore size,and the volume of transitional pores,mesopores,macropores and total pores increases.Based on the distribution of pore size,the operation mode of ‘‘water infusion after gas extraction,then continuing gas extraction" is recommended to improve the volume of coal mine gas drainage.When the reflectance of vitrinite in coal samples is less than 1,using the surfactants Fast T,1631,APG,BS can mitigate the damage caused by the water blocking effect.But when the reflectance of vitrinite is larger than 1.4,the damage caused by the water blocking effect can be increased.When the surfactant CMC is used in hydraulic applications,the capillary forces of coal samples are almost negative,which means the capillary force is in the same direction as the gas extraction.The direction of capillary forces benefits the gas flow.So,using CMC can play an active role in removing the water blocking effect.Centrifugal experiments confirm that using CMC can effectively remove the water blocking effect,which has a beneficial effect on improving the gas drainage volume.

Enzymatic saccharification of cellulose using an ionic liquid [Amim] [COOH] pretreatment

In this study we used l-allyl-3-methyl imidazole formate （[Amim][COOH]） as ionic liquid to pre-treat the cellulose and determined the rate of polymerization and enzymatic hydrolysis. The results showed that pretreatment with （[Amim][COOH]） significantly decreased the cellulose polymerization. As the pretreatment temperature went up, the enzymatic hydrolysis rate was first increased and then decreased The maximal enzymatic hydrolysis rate was achieved when the pretreatment temperature was 90 ℃. Under the ultrasonic condition, the initial rate of enzmatic hydrolysis for the ionic liquid-treated cellulose was up to 11.10 gL-1h-1, which was 33% increase compared to the untreated cellulose. Scanning Electronic Microscopy （SEM） and Fourier Transform Infrared-Raman Spectroscop （FT-IR） analysis showed that ionic liquidtreated cellulose started to depolymerize. In addition, the cr3＇stallinity of the cellulose was significantly decreased after pretreatment with ionic liquid.

An Experimental Study on Alkaline/Surfactant/Polymer Flooding Systems Using Natural Mixed Carboxylate

Orthogonal-test-design method has been used to determine the optimal formula by phase behavior and interfacial tension studies, respectively. The effect of each component of two alkaline/surfactant/polymer flooding systems on interfacial tension is discussed, in which a low-price natural mixed carboxylate (SDC) is used as the major surfactant. The results indicate that the optimal composition is SDC (0.5%), alkaline NaHCO3/Na2CO3 with mass ratio of 1 (1.0%), and hydrolyzed polyacrylamide(0.1%). In the coreflood experiment, their oil recovery is increased by about 25.2% and 26.8% original oil in place, respectively.

Boosting chiral carboxylic acid hydrogenation by tuning metal-MO_(x)-support interaction in Pt-ReO_(x)/TiO_(2) catalysts

Engineering the surface microenvironment by tuning the binary interactions between a supported metal with a secondary metal oxide(MO_(x))or support has been a common method for improving the catalytic performance of supported metal catalysts.However,few studies have investigated the ternary interactions among the metal,MO_(x),and support.Here,we report for the first time the formation of metal-MO_(x)-support interaction(MMSI)in reducible TiO_(2)-supported PtReO_(x) catalysts,affording 87% yield and 100% ee in the tandem hydrogenation of an aqueous chiral cyclohexane-1,2-dicarboxylic acid into the corresponding diol;the catalytic activity is eight times higher than that obtained with non-reducible support counterparts in the same reaction via traditional batch synthesis with multiple steps and unfriendly reagents.Detailed experimental and computational studies suggest that the TiO_(2) crystalline phase-dependent density of the oxygen vacancies induces different Pt-ReO_(x)-TiO_(2) interactions,which dominate the electron transfer therein and tune the adsorption strength of the carbonyl moiety of the substrate/intermediate,thus promoting the hydrogenation activity and selectivity.In addition,the strong MMSI endows the optimal rutile TiO_(2) supported PtReO_(x) catalyst with an outstanding lifetime of 400 h in a fixed-bed reactor under acidic aqueous conditions and ensures efficient applications in the selective hydrogenation of aliphatic dicarboxylic acids and functional carboxylic acids.This work provides a promising strategy for the development of efficient and stable supported catalysts for the selective hydrogenation of diverse C-O and C=O bonds.

Solvent Extraction of Yttrium by Task-specific Ionic Liquids Bearing Carboxylic Group

A new kind of hydrophobic ionic liquids [1-alkyl-3-（1-carboxylpropyl）im][PF6] has been synthesized, and their extraction.properties for Y（III） in the nitric acid medium was also investigated. The effects of extractant concentration, equilibrium pH of aqueous phase, salt concentration, temperature etc. were discussed. The results show that this kind of Task-Specific Ionic Liquid （TSIL） needs to be saponified before being used for the Y（III） extraction, and the extraction is-acid dependent,-and the extraction efficiency increases with the aqueous phase acldity decreasing. Furthermore, the loaded organic phase is easy to be stripped; more than 95% Y（III） could be stripped from the loaded organic phase when the stripping acidity is higher than 0.07 mol-L-1. The slope analysis technique is used to investigate the extraction mechanism, and a possible cation-exchange extraction mechanism is proposed in the oresent extraction system.

Binary and Ternary Complexes of Cd（ll） Involving Pyrazine 2,3-Dicarboxylic Acid and Various Biologically Relevant Ligands

Binary and ternary complexes of Cd（II） involving pyrazine 2,3-dicarboxylic acid （pzdca） and various biologically relevant ligands containing different functional groups are investigated at 25 ℃, I = 0.10 M （NaNO3） and in 20% （v/v） ethanol-water media. The ligands （L） used are amino acids, dicarboxylic acids and peptides. The results showed the formation of Cd （pzdca） （L） complexes with amino acids and dicarboxylic acids. Peptides form both Cd （pzdca） （L） complexes and the corresponding deprotonated amide species Cd （pzdca） （LH-1）. The relative stabilities of ternary complexes are compared with those of the corresponding binary complexes in terms of AlogK values. The concentration distribution of the complexes in solution was evaluated.

Isolation and structural identification of two bioactive phenazines from Streptomyces griseoluteus P510

Phenazine antibiotics phenazine-l-carboxylic acid （PCA） and l-hydroxyphenazine （1-OH-PHZ） were purified from culture broth and mycelia ofStreptomyces griseoluteus P510, Both PCA and 1 -OH-PHZ exhibit strong antifun- gal activity against six plant pathogens, especially Fusarium oxysporium, with minimal inhibition concentrations less than I and 2/ag, ml- 1 for PCA and 1-OH-PHZ, respectively, The presence of PCA and 1 -OH-PHZ indicates that S. griseoluteus PSlO can be used as a potential source of pesticides,

Chaotic Characteristics of Bubbles Rising with Coalescences in Pseudoplastic Fluid

The chaotic characteristics of bubbles rising with accompanying coalescences in pseudoplastic aqueous carboxymethylcellulose sodium(CMC)solution were studied by means of smoothed pseudo Wigner-Ville distribution and Wigner-Hough distribution.The temporal signal of bubble passage was measured utilizing a photoconductive data acquisition system.As bubble coalescence occurred,the smoothed pseudo Wigner-Ville distribution of the signal revealed that the signal could be divided into low-frequency and high-frequency ranges and the transition range according to the distribution feature of frequency domain,which reflected eddy motion of fluid,high frequency fluctuations of fluid velocity and other random components measured in the signal,and bubbles rising accompanied with coalescences,respectively.However,bubble coalescence occurred in the lower position and the frequency range of bubbles motion became wide under higher gas flowrate,while the frequency range of bubbles motion became narrow when the CMC concentration increased.The typical dynamics of bubbles motion,such as periodicity,bifurcation and chaos,could be easily found in terms of the Wigner-Hough distribution.

Crystal Structure of Carboxypeptidase a Complexed with an Inactivator in a New Crystalline Form

A new crystalline form of carboxypeptidase A (CPA) complexes withan inactivator was obtained by the method of hanging drop vapor diffusion. The inacti-’vator, 2-benzyl-3-iodo-propanoic acid (BIPA ), binds covalently to an active siteresidue Glu-27O of CPA. The complex was crystallized in space group P212121 with a= 48. 8 A, b=66. 9 A, c= 96. 0 A. The complex structure was determined by molecu-lar replacement using the native CPA crystal structure as the search model. The finalcrystallographic residual is 0. 152. Except for the modification of Glu-270, the inactiva-tor exhibits normal binding mode compared with other ligand complexes of CPA. Inthe final different electron density maps (2Fo-Fc, Fo-Fc), the density of the iodo ioncould not be found while the conserved molecule remains coordinated to Zn2+ as in thenative CPA. Comparisons of complex of CPA-BIPA with the native CPA and theCPA/D-Phe complex are presented. The mechanism of inactivation of CPA was dis-cussed.

Construction and functional activity of a recombinant vector expressing rat glutamic acid decarboxylase 65

Objective Glutamic acid decarboxylase 2（GAD65） is a gamma-aminobutyric acid（GABA） synthetase.This study aimed to construct a recombinant lentivirus-rGAD65（rLV-rGAD65） vector containing the cDNA of rat GAD65（rGAD65） and assess its functional activity in vitro and in vivo.Methods cDNA of rGAD65 was amplified by RT-PCR and subcloned into the LV vector,forming the rLV-GFP-rGAD65 plasmid.The recombinant lentivirus particles（rLVrGAD65） were packaged by the LV Helper-Free System and the titer was measured.Primary rat lung fibroblasts were transfected with rLV-rGAD65.The expression of rGAD65 in fibroblasts was detected by immunocytochemistry and western blot and the level of GABA in the medium was assessed by high-performance liquid chromatograph（HPLC）.In vivo,rLV-rGAD65 was injected into the subthalamic nucleus（STN） of Sprague-Dawley rats using stereotaxic methods,and rGAD65 protein levels in the STN were assessed by immunohistochemistry and Western blot,while the GABA concentration in the substantia nigra pars reticulata（SNr） was assayed by HPLC.Results The sequence of rGAD65 cDNA was in accord with that in GenBank.The amino-acid sequence of rGAD65 had no mutations and the titer of rLVrGAD65 reached 6.8 × 108/mL.The efficiency of infection of fibroblasts was 80%,and the concentration of GABA in the medium was（48.14 ± 9.35） nmol/L.In vivo,rGAD65 expression was detected in the STN,and the concentration of GABA in the SNr increased from（5.95 ± 1.09） to（12.44 ± 3.79） nmol/g tissue.Conclusion The recombinant LVGFP-rGAD65 vector was successfully constructed.rLV-rGAD65-infected primary fibroblasts in vitro and the expressed rGAD65 catalyzed the formation of GABA from glutamic acid.In vivo,the concentration of GABA in the SNr was increased after rLV-rGAD65 injection into the STN.

An efficient and surface-benign purification scheme for colloidal nanocrystals based on quantitative assessment

General application of ＂greener methods＂ to the synthesis of monodisperse colloidal nanocrystals introduces impurities, including metal carboxylate precursors, non-volatile solvents, free ligands, and non-nanocrystalline side products. These impurities seriously diminish the solution processability and potential applications of colloidal nanocrystals. A protocol was established for evaluating purification schemes. The results revealed that commonly applied purification schemes and their variants do not exhibit a high level of performance and may degrade the ligand surface coverage. A new scheme involving chloroformacetonitrile precipitation quantitatively removed all impurities from colloidal solutions of CdSe and CdS nanocrystals coated with a variety of carboxylate ligands. The new scheme was benign to the surface structure of nanocrystaMigands complexes and resulted in each nanocrystal bearing a close-packed monolayer of carboxylate ligands.