bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactions between Endostatin and Vascular Endothelial Growth Factor (VEGF) and Inhibition of Choroidal Neovascularization
Authors: Wang Xun , Xu Xun , Tang Luosheng , Song Shiping , Fan Chunhai
Published: October 2008

This study was designed to evaluate the inhibitory effect of endostatin onchoroidal neovascularization (CNV) in laser-induced rat model. Choroidalneovascularization was induced in Brown Norway (BN) rats by diode-laserphotocoagulation. Rats were randomly divided into five groups (10 animals in each group):endostatin 20mg/kg group, endostatin 10mg/kg group, laser injury group, normal salinegroup and blank control group. The animals were treated with endostatin, normal saline,laser injury or without treatment on day 0 to day 13 after laser photocoagulation. On day 7and 14 after laser photocoagulation, the CNV formation was assessed by fluoresceinangiography and histopathological analysis. VEGF expression in retina was determined byimmunohistochemical assay. In two endostatin groups, the incidence of CNV formation andthe intensity of fluorescein leakage were reduced compared with the two control groups. Nosignificant difference was found between laser injury group and normal saline group. Theexpression of VEGF reached peak at day 7 and then decreased from day 14 afterphotocoagulation. The expression of VEGF was significantly reduced in the two endostaingroups than laser injury group in a dose-dependent way. Endostatin can inhibit the formationof experimental CNV in the rat. Down-regulation of VEGF expression could be one of themechanisms underlying the inhibition of CNV by endostatin.
Interactions between Cytochrome c and DNA Strands Self-Assembled at Gold Electrode
Authors: Lao Ruojun , Wang Lihua , Wan Ying , Zhang Jiong , Song Shiping , Zhang Zhizhou , Fan Chunhai , He Lin
Published: October 2008

In this work, we reported the investigation on the interaction between DNAstrands self-assembled at gold electrodes and an electron transfer protein, cytochrome c. Weobserved that cytochrome c exhibited well-defined electrochemistry in both double-strandedand single-stranded DNA films. This suggested that the electron transfer reaction ofcytochrome c arose possibly due to the electron hopping along DNA strands rather thanwiring along the double helix. We also compared the heterogeneous electron transfer rate ofcytochrome c with that of a ruthenium complex, which further confirmed this mechanism.
Rheological Behaviors of Polyacrylonitrile/1-Butyl-3- Methylimidazolium Chloride Concentrated Solutions
Authors: Liu Weiwei , Cheng Lingyan , Zhang Hongyan , Zhang Yumei , Wang Huaping , Yu Mingfang
Published: October 2008

One of the room temperature ionic liquids (RTILs), 1-butyl-3-methylimidazoliumchloride ([BMIM]Cl) was chosen to prepare the concentrated solutions of Polyacrylonitrile(PAN). The rheological behaviors of the solutions were measured with rotational rheometryunder different conditions, including temperatures, concentration, and molecular weight ofPAN. The solutions exhibited shear-thinning behaviors, similar to that of PAN/DMFsolutions. The viscosities decreased with the increasing of shear rates. However, theviscosity decreased sharply at high shear rates when the concentration was up to 16wt%. Thedependence of the viscosity on temperature was analyzed through the determination of theapparent activation energy. Unusually, the viscosity of solutions of higher concentration islower than that of lower concentration. Similarly, the viscosity of low molecular weightPAN was higher than high molecular weight PAN at high shear rates. The dynamicrheological measurement indicates the loss modulus is much higher than storage modulus.The trend of complex viscosity is similar with the result of static rheological measurement.The interaction between PAN and ionic liquid [BMIM]Cl was discussed.
Expression of VDAC Regulated by Extracts of Limonium sinense Ktze root Against CCl4-induced Liver Damage
Authors: Tang Xinhui , Ga Jing , Chen Jin , Xu Lizhi , Tang Yahong , Dou Huan , Yu Wen , Zhao Xiaoning
Published: October 2008

The expression of mitochondrial voltage-dependent anion channels (VDAC) mayunderlie the protective effects of Limonium sinense (Girard) Ktze root extracts (LSE) againstcarbon tetrachloride-induced liver damage. Pretreatment of mice with 100 mg/kg, 200mg/kg or 400 mg/kg LSE significantly blocked the carbon tetrachloride-induced increase inboth serum aspartate aminotransferase (sAST) and serum alanine aminotransferase (sALT)levels. Ultrastructural observations by electron microscope confirmed hepatoprotection,showing decreased nuclear condensation, ameliorated mitochondrial fragmentation of thecristae and less lipid deposition. Pretreatment with LSE prevented the decrease of thedisruption of mitochondrial membrane potential (15.3%) observed in the liver of the carbontetrachloride-insulted mice, further demonstrating the mitochondrial protection. In addition,LSE treatment (100-400 mg/kg) significantly increased both transcription and translation ofVDAC. The above data suggests that LSE mitigates the damage to liver mitochondriainduced by carbon tetrachloride, possibly through regulation of mitochondrial VDAC, one ofthe most important proteins in the mitochondrial outer membrane.
The SPASIBA Force Field for Studying Iron-Tannins Interactions : Application to Fe3+ /Fe2+ Catechol Complexe
Authors: Yapo-Kicho D. , Lagant P. , Vergoten G.
Published: October 2008

The SPASIBA force field parameters have been obtained for Fe3+ /Fe2+ -Oxygeninteractions occuring between non-heminic iron and hydroxyl groups of polyphenols foundin tannins. These parameters were derived from normal modes analyses based on quantumchemical calculations using the Density Functional Theory (DFT). Four models involvingcomplexation of iron with water ([Fe(H2O)6]3+ , [Fe(H2O)6]2+ ) and with cathechol molecules([Fe(cat)2(H2O)2]-1, [Fe(cat)2(H2O)2]-2) were studied using the Density Functional Theoryand the B3LYP hybrid functional under high spin states of iron.
Biochemical Analyses of Csx/Nkx2.5 Mutants and Their Structure–Function Relationship
Authors: Chen Yun-Zi , Ying Hua , Zhang Jing , Cheng Wei , Kang Yuan-Xi , Hua Zi-Chun
Published: October 2008

A homeodomain-containing transcription factor Csx/Nkx2.5 is an importantregulator of cardiogensis in mammals. There has been considerable interest in understandingdeterminants of the diverse cardiac phenotypes associated with Csx/Nkx2.5 mutationssituated within or around the homeodomain in patients. To make clear of the functionalproperties of the regions out of homeodomain, we found that mutants locate outside of thehomeodomain retained intact nuclear localization and have nearly normal or increasedtranscriptional activity but impaired DNA binding capability, the C-terminus region exhibitsan inhibitory function on transcriptional activity of wild type Csx/Nkx2.5, and the NK2-Specific Domain is likely to facilitate both DNA binding and protein-protein interaction. Inthe current study, deletion mutant in homeodomain displayed extremely different biologicalappearance from the mutants with deletion outside of the homeodomain, these may explainthe clinical observation that patients with missense situated outside the homeodomain werenot associated with atrioventricular conduction disturbance.
Radical-scavenging Activity of Estrogen and Estrogen-like Compounds Using the Induction Period Method
Authors: Kadoma Yoshinori , Fujisawa Seiichiro
Published: October 2008

The radical-scavenging activity of estrogens (estrone, 2-hydroxyestradiol),estrogen-like compounds (diethylstilbestrol, DES; bisphenol A, BPA) and the mono-phenolic compound 2,6-di-t-butyl-4-methoxyphenol (BMP) was investigated using themethod of measuring the induction period for polymerization of methyl methacrylate(MMA) initiated by thermal decomposition of 2,2'-azobisisobutyronitrile (AIBN) andbenzoyl peroxide (BPO) at 70°C using differential scanning calorimetry (DSC). Thestoichiometric factor (n, number of free radicals trapped by one mole of antioxidantmoiety) for the AIBN system declined in the order BMP (2.0), 2-hydroxyestradiol (2.0)>DES (1.3) > BPA (1.2) > estrone (0.9), whereas that for the BPO system declined in theorder BMP (2.0) >DES (1.9), BPA (1.9) > estrone (1.3) > 2-hydroxyestradiol (0.7). Theinhibition rate constant (kinh x 10-3 M-1s-1) for the AIBN system declined in the orderestrone (2.2) > BPA (2.0) > DES (1.9) > 2-hydroxyestradiol (1.2) > BMP (1.1), whereasthat for the BPO system declined in the order 2-hydroxyestradiol (3.2) > estrone (1.4) >DES (1.2) > BPA (1.0) > BMP (0.9). The radical-scavenging activity for bioactivecompounds such as estrogens should be evaluated using these two methods (the n and kinh)to elucidate the mechanism of a particular reaction. The great difference of the n and kinhfor estrogens between the AIBN and BPO system suggested that their oxidation process iscomplex.
Introducing Spectral Structure Activity Relationship (S-SAR) Analysis. Application to Ecotoxicology
Authors: Putz Mihai V. , Lacrămă Ana-Maria
Published: October 2008

A novel quantitative structure-activity (property) relationship model, namelySpectral-SAR, is presented in an exclusive algebraic way replacing the old-fashionedmulti-regression one. The actual S-SAR method interprets structural descriptors as vectorsin a generic data space that is further mapped into a full orthogonal space by means of theGram-Schmidt algorithm. Then, by coordinated transformation between the data andorthogonal spaces, the S-SAR equation is given under simple determinant form for anychemical-biological interactions under study. While proving to give the same analyticalequation and correlation results with standard multivariate statistics, the actual S-SARframe allows the introduction of the spectral norm as a valid substitute for the correlationfactor, while also having the advantage to design the various related SAR models throughthe introduced “minimal spectral path” rule. An application is given performing a completeS-SAR analysis upon the Tetrahymena pyriformis ciliate species employing its reportedeco-toxicity activities among relevant classes of xenobiotics. By representing the spectralnorm of the endpoint models against the concerned structural coordinates, the obtainedS-SAR endpoints hierarchy scheme opens the perspective to further design the eco-toxicological test batteries with organisms from different species.
Prediction of Standard Enthalpy of Formation by a QSPR Model
Authors: Vatani Ali , Mehrpooya Mehdi , Gharagheizi Farhad
Published: October 2008

The standard enthalpy of formation of 1115 compounds from all chemicalgroups, were predicted using genetic algorithm-based multivariate linear regression (GA-MLR). The obtained multivariate linear five descriptors model by GA-MLR has correlationcoefficient ( R 2 = 0.9830 ). All molecular descriptors which have entered in this model arecalculated from chemical structure of any molecule. As a result, application of this modelfor any compound is easy and accurate.
Hydrolysis and Partial Recycling of a Chloroaluminate Ionic Liquid
Authors: Fang Ming-Hong , Wang Li-Sheng
Published: October 2008

Hydrolysis of the ionic liquid Et3NHCl-2AlCl3 and a process for recycling thetriethylamine were studied. When the hydrolysis was carried out at a relatively hightemperature, the released HCl could be absorbed more easily. With addition of sodiumhydroxide to the aqueous hydrolysis solution, a feasible process for recycling triethylaminewas developed, involving first distillation of triethylamine, followed by filtration of thealuminium hydroxide. The yield of recovered triethylamine was about 95%. Thetriethylhydrogenammonium chloride prepared from the recycled triethylamine was of goodpurity and could be reused to synthesize new chloroaluminate ionic liquids.
Branched-chain Amino Acid Biosensing Using Fluorescent Modified Engineered Leucine/Isoleucine/Valine Binding Protein
Authors: Chino Sakura , Sakaguchi Akane , Yamoto Rie , Ferri Stefano , Sode Koji
Published: October 2008

A novel fluorescence sensing system for branched-chain amino acids (BCAAs)was developed based on engineered leucine/isoleucine/valine-binding proteins (LIVBPs)conjugated with environmentally sensitive fluorescence probes. LIVBP was cloned fromEscherichia coli and Gln149Cys, Gly227Cys, and Gln254Cys mutants were generated bygenetic engineering. The mutant LIVBPs were then modified with environmentallysensitive fluorophores. Based on the fluorescence intensity change observed upon thebinding of the ligands, the MIANS-conjugated Gln149Cys mutant (Gln149Cys-M) showedthe highest and most sensitive response. The BCAAs Leu, Ile, and Val can each bemonitored at the sub-micromolar level using Gln149Cys-M. Measurements were alsocarried out on a mixture of BCAFAs and revealed that Gln149Cys-M-based measurementis not significantly affected by the change in the molar ratio of Leu, Ile and Val in thesample. Its high sensitivity and group-specific molecular recognition ability make the newsensing system ideally suited for the measurement of BCAAs and the determination of theFischer ratio, an indicator of hepatic disease involving metabolic dysfunction.
Near Infrared Spectroscopy for On-line Monitoring of Alkali- Free Cloth /Phenolic Resin Prepreg During Manufacture
Authors: Jiang Bo , Huang Yu Dong
Published: October 2008

A NIR method was developed for the on-line monitoring of alkali-freecloth/phenolic resin prepreg during its manufacturing process. First, the sizing content ofthe alkali-free cloth was analyzed, and then the resin, soluble resin and volatiles content ofthe prepreg was analyzed simultaneously using the FT-NIR spectrometer. Partial leastsquare (PLS) regression was used to develop the calibration models, which for the sizingcontent was preprocessed by 1stDER MSC, for the volatile content by 1stDER VN, forthe soluble resin content by 1stDER MSC and for the resin content by the VN spectraldata preprocessing method. RMSEP of the prediction model for the sizing content was0.732 %, for the resin content it was 0.605, for the soluble resin content it was 0.101 andfor volatiles content it was 0.127. The results of the paired t-test revealed that there was nosignificant difference between the NIR method and the standard method. The NIRspectroscopy method could be used to predict the resin, soluble resin and the volatilescontent of the prepreg simultaneously, as well as sizing content of alkali-free cloth. Theprocessing parameters of the prepreg during manufacture could be adjusted quickly withthe help of the NIR analysis results. The results indicated that the NIR spectroscopymethod was sufficiently accurate and effective for the on-line monitoring of alkali-freecloth/phenolic resin prepreg.
Asymmetric Glyoxylate-Ene Reactions Catalyzed by Chiral Pd(II) Complexes in the Ionic Liquid [bmim][PF6]
Authors: He Xi Jun , Shen Zhen Lu , Mo Wei Min , Hu Bao Xiang , Sun Nan
Published: October 2008

The room temperature ionic liquid [bmim][PF6] was employed as the reactionmedium in the asymmetric glyoxylate-ene reaction of α-methyl styrene (4a) with ethylglyoxylate using chiral palladium(II) complexes as the catalysts. [Pd(S-BINAP)(3,5-CF3-PhCN)2](SbF6)2 (1b) showed the highest catalytic activity. Under the reaction conditionsof 40 oC, 0.5 h, and 1b/4a molar ratio of 0.05, ethyl α-hydroxy-4-phenyl-4-pentenoate wasobtained in excellent chemical yield (94 %) with high enantioselectivity (70 %). Otherα-hydroxy esters can also be obtained in high chemical yields and enantioselectitiesthrough the glyoxylate-ene reactions of alkenes with glyoxylates catalyzed by 1b in[bmim][PF6]. Moreover, the ionic liquid [bmim][PF6] which contained the palladium(II)complex could be recycled and reused several times without significant loss of the catalyticactivity.
Electronegativity Equalization Method: Parameterization and Validation for Large Sets of Organic, Organohalogene and Organometal Molecule
Authors: Varekova Radka Svobodova , Jirouskova Zuzanna , Vanek Jakub , Suchomel Simon , Koca Jaroslav
Published: October 2008

The Electronegativity Equalization Method (EEM) is a fast approach for chargecalculation. A challenging part of the EEM is the parameterization, which is performedusing ab initio charges obtained for a set of molecules. The goal of our work was to performthe EEM parameterization for selected sets of organic, organohalogen and organometalmolecules. We have performed the most robust parameterization published so far. The EEMparameterization was based on 12 training sets selected from a database of predicted 3Dstructures (NCI DIS) and from a database of crystallographic structures (CSD). Each setcontained from 2000 to 6000 molecules. We have shown that the number of molecules inthe training set is very important for quality of the parameters. We have improved EEMparameters (STO-3G MPA charges) for elements that were already parameterized,specifically: C, O, N, H, S, F and Cl. The new parameters provide more accurate chargesthan those published previously. We have also developed new parameters for elements thatwere not parameterized yet, specifically for Br, I, Fe and Zn. We have also performedcrossover validation of all obtained parameters using all training sets that included relevantelements and confirmed that calculated parameters provide accurate charges.
On the Extraction of Aromatic Compounds from Hydrocarbons by Imidazolium Ionic Liquids
Authors: Cassol Cláudia C. , Umpierre Alexandre P. , Ebeling Günter , Ferrera Bauer , Chiaro Sandra S. X. , Dupont Jairton
Published: October 2008

The liquid-liquid equilibrium for the ternary system formed by n-octane andaromatic (alkylbenzenes) and heteroaromatic compounds (nitrogen and sulfur containingheterocyles) and 1-alkyl-3-methylimidazolium ionic liquids (ILs) associated with variousanions has been investigated. The selectivity on the extraction of a specific aromaticcompound is influenced by anion volume, hydrogen bond strength between the anion andthe imidazolium cation and the length of the 1-methyl-3-alkylimidazolium alkyl side chain.The interaction of alkylbenzenes and sulfur heterocyles with the IL is preferentially throughCH-π hydrogen bonds and the quantity of these aromatics in the IL phase decreases withthe increase of the steric hindrance imposed by the substituents on the aromatic nucleus. Inthe case of nitrogen heterocycles the interaction occurs preferentially throughN(heteroaromatic)-H(imidazolium) hydrogen bonds and the extraction process is largelycontrolled by the nitrogen heterocycle pKa. Competitive extraction experiments suggestthat benzene, pyridine and dibenzothiophene do not compete for the same hydrogen bondsites of the IL.
Dinuclear Zinc (II) Complexes of Macrocyclic Polyamine Ligands Containing an Imidazolium Bridge: Synthesis, Characterization, and Their Interaction with Plasmid DNA
Authors: Huang Jun , Huang Qing-Dong , Zhang Ji , Zhou Li-Hong , Li Qiang-Lin , Li Kun , Jiang Ning , Lin Hong-Hui , Wu Jiang , Yu Xiao-Qi
Published: October 2008

Two novel macrocyclic polyamine ligands and their dinuclear zinc (II)complexes were synthesized and characterized. Their interaction with plasmid DNA wasstudied by gel electrophoresis and fluorescence quenching experiment. The result showedthat these complexes could bind DNA efficiently under physiological conditions.
Irradiation Effects on Phenolic Content, Lipid and Protein Oxidation and Scavenger Ability of Soybean Seeds
Authors: Štajner Dubravka , Milošević Mirjana , Popović Boris M.
Published: October 2008

The effect of medium doses of γ-irradiation (1-10 kGy) on total phenolic andtannin contents, lipid peroxidation, protein oxidation intensity and soluble protein contentof soybean seeds, (genotype Ana), was investigated. Screening for antioxidant ability wasperformed using FRAP and DPPH methods. Total phenolic and tannin contents and DPPHscavenger activity were increased, while protein oxidation intensity was decreased byapplied doses of γ-irradiation. Gamma irradiation provoked insignificant changes in lipidperoxidation and soluble protein content, while protein oxidation intensity wassignificantly decreased when dose of 10 kGy was applied. Presented results implicated thatincreased antioxidant capacity and protein stability of soybean seeds were increased afterapplication of γ-irradiation.
UVB-Protective Effects of Isoflavone Extracts from Soybean Cake in Human Keratinocytes
Authors: Chiang Han-Sun , Wu Wen-Bin , Fang Jia-You , Chen Bing-Huei , Kao Tsai-Hua , Chen Ying-Ting , Huang Chieh-Chen , Hung Chi-Feng
Published: October 2008

It has been shown by chromatography that aglycone, glucoside, acetylglucosideand malonylglucoside isoflavone extracts prepared from soybean cake showed betterantioxidant activities than isoflavone standards. Consequently, the aim of this study was toevaluate the protective effects of these isoflavone extracts against ultraviolet B (UVB)-induced keratinocyte damage. Our results demonstrated that these soybean cake isoflavoneextracts could inhibit UVB-induced keratinocyte death. Moreover, they could inhibit UVB-induced intracellular release of hydrogen peroxide (H2O2) Furthermore, these isoflavoneextracts differentially inhibited UVB-induced MAPK phosphorylation. The ERK1/2 andp38 phosphorylation was not inhibited by all tested isoflavone extracts, whereas JNKphosphorylation was inhibited by group I to group III isoflavone extracts. Since theseisoflavone extracts are relative stable and easily obtained than the isoflavone standards, wesuggest that soybean cake may be a useful potential source for developing effective skincare agents in against photoaging.
The Preparation and Characterization of Poly(m-phenylene- isophthalamide) Fibers Using Ionic Liquids
Authors: Zhao Tingting , Wang Huaping , Zhang Yumei , Wang Biao , Jiang Jianming
Published: October 2008

A process to produce fibers from Poly(m-phenyleneisophthalamide)(PMIA)solution in an ionic liquid via wet-spinning technology are described. The spinning processwas investigated on a small laboratory scale. Ionic liquid spinning solutions were firstprepared for PMIA fibers, followed by wet spinning. In the course of this research, thephysical properties of the PMIA fibers were estimated. We studied the dependence of themechanical properties of the obtained PMIA fibers on the composition of the coagulationbath, and on the choice of solvent in spinning solution. The morphology of the fibers fromionic liquid and traditional DMAc solvents via wet-spinning process were observed byscanning electrical microscopy(SEM). The differences of morphologies and properties ofthe PMIA fibers obtained from two different solvents are discussed.
Non-Open Access and Its Adverse Impact on International Journal of Molecular Sciences
Authors: Lin Shu-Kun
Published: October 2008

In 2005 and 2006 papers were published in MDPI journals in both non-Open Access (non-OA) and Open Access (OA) form [1,2].[...]
Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone
Authors: Romero Jorge Marcelo , Bustillo Soledad , Maisuls Hugo Enrique Ramirez , Jorge Nelly Lidia , Vara Manuel Eduardo Gómez , Castro Eduardo Alberto , Jubert Alicia H.
Published: October 2008

A thermochemical rather simple experimental technique is applied to determinethe enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented withsuitable theoretical calculations at the semiempirical and ab initio levels. A particularsatisfactory agreement between both ways is found for the ab initio calculation at the 6-311G basis This set level. Some possible extensions of the present procedure are pointedout.
Hydroformylation of Cyclohexene with Carbon Dioxide and Hydrogen Using Ruthenium Carbonyl Catalyst: Influence of Pressures of Gaseous Components
Authors: Fujita Shin-ichiro , Okamura Shuhei , Akiyama Yoshinari , Arai Masahiko
Published: October 2008

Hydroformylation of cyclohexene was studied with a catalyst system ofRu3(CO)12 and LiCl using H2 and CO2 instead of CO in NMP. The influence of H2 andCO2 pressures on the total conversion and the product distribution was examined. It wasshown that increasing total pressure of H2 and CO2 promoted the reverse water gas shiftreaction and increased the yield of cyclohexanecarboxaldehyde. Its hydrogenation tocyclohexanemethanol was promoted with increasing H2 pressure but suppressed withincreasing CO2 pressure. Cyclohexane was also formed along with those products and thisdirect hydrogenation was suppressed with increasing CO2 pressure. The roles of CO2 as apromoter as well as a reactant were further examined by phase behavior observations andhigh pressure FTIR measurements.
A Spectral-SAR Model for the Anionic-Cationic Interaction in Ionic Liquids: Application to Vibrio fischeri Ecotoxicity
Authors: Lacrămă Ana-Maria , Putz Mihai V. , Ostafe Vasile
Published: October 2008

Within the recently launched the spectral-structure activity relationship (S-SAR)analysis, the vectorial anionic-cationic model of a generic ionic liquid is proposed, alongwith the associated algebraic correlation factor in terms of the measured and predictedactivity norms. The reliability of the present scheme is tested by assessing the Hanschfactors, i.e. lipophylicity, polarizability and total energy, to predict the ecotoxicityendpoints of wide types of ionic liquids with ammonium, pyridinium, phosphonium,choline and imidazolium cations on the aquatic bacteria Vibrio fischeri. The results, whileconfirming the cationic dominant influence when only lipophylicity is considered,demonstrate that the anionic effect dominates all other more specific interactions. It wasalso proved that the S-SAR vectorial model predicts considerably higher activity for theionic liquids than for its anionic and cationic subsystems separately, in all consideredcases. Moreover, through applying the least norm-correlation path principle, the completetoxicological hierarchies are presented, unfolding the ecological rules of combined cationicand anionic influences in ionic liquid toxicity.
Developments in Molecular Recognition and Sensing at Interfaces
Authors: Ariga Katsuhiko , Hill Jonathan P. , Endo Hiroshi
Published: October 2008

In biological systems, molecular recognition events occur mostly withininterfacial environments such as at membrane surfaces, enzyme reaction sites, or at theinterior of the DNA double helix. Investigation of molecular recognition at model interfacesprovides great insights into biological phenomena. Molecular recognition at interfaces notonly has relevance to biological systems but is also important for modern applications suchas high sensitivity sensors. Selective binding of guest molecules in solution to hostmolecules located at solid surfaces is crucial for electronic or photonic detection of analytesubstances. In response to these demands, molecular recognition at interfaces has beeninvestigated extensively during the past two decades using Langmuir monolayers, self-assembled monolayers, and lipid assemblies as recognition media. In this review, advancesof molecular recognition at interfaces are briefly summarized.
A Possible Industrial Solution to Ferment Lignocellulosic Hydrolyzate to Ethanol: Continuous Cultivation with Flocculating Yeast
Authors: Purwadi Ronny , Brandberg Tomas , Taherzadeh Mohammad J.
Published: October 2008

The cultivation of toxic lignocellulosic hydrolyzates has become a challengingresearch topic in recent decades. Although several cultivation methods have been proposed,numerous questions have arisen regarding their industrial applications. The current workdeals with a solution to this problem which has a good potential application on anindustrial scale. A toxic dilute-acid hydrolyzate was continuously cultivated using a high-cell-density flocculating yeast in a single and serial bioreactor which was equipped with asettler to recycle the cells back to the bioreactors. No prior detoxification was necessary tocultivate the hydrolyzates, as the flocks were able to detoxify it in situ. The experimentswere successfully carried out at dilution rates up to 0.52 h-1. The cell concentration insidethe bioreactors was between 23 and 35 g-DW/L, while the concentration in the effluent ofthe settlers was 0.32 ± 0.05 g-DW/L. An ethanol yield of 0.42-0.46 g/g-consumed sugarwas achieved, and the residual sugar concentration was less than 6% of the initialfermentable sugar (glucose, galactose and mannose) of 35.2 g/L.
Relationships between Xanthohumol and Polyphenol Content in Hop Leaves and Hop Cones with Regard to Water Supply and Cultivar
Authors: Ceh Barbara , Kac Milica , Košir Iztok J. , Abram Veronika
Published: October 2008

The effect of water supply – especially of drought stress – on the content ofsome secondary metabolites in hops (Humulus lupulus L.) was studied. The experimenttook place in 2006. Some relevant data from 2005 were included for comparison. Leavesand cones of nine hop cultivars grown under field conditions as well as in a pot experimentunder three water regimes were analyzed. The cultivars ranged from those most grown inSlovenia to promising crossbreed being tested. Leaves were sampled from July 18, 2006 toAugust 18, 2006, while cones were picked in the time of technological maturity. Standardanalytical methods were applied to determine the contents of xanthohumol, polyphenolsand α-acids in hop leaves and hop cones. The contents of the secondary metabolites inquestion depended more on the cultivar under investigation than on the water supply, atleast as far the growing conditions for a relatively normal development of the plant weremet.
Application of Osthol Induces a Resistance Response Against Powdery Mildew in Pumpkin Leave
Authors: Shi Zhiqi , Wang Fei , Zhou Wei , Zhang Peng , Fan Yong Jian
Published: October 2008

Plants can defend themselves against fungal infection by natural means inducedby biotic and abiotic elicitors. Osthol is a natural compound extracted from dried fruits ofCnidii Monnieri Fructus. In this study, it has been shown to not only be a fungicide withacceptable curative properties (control efficacy of 68.72), but it also showed a significantprophylactic effect (with control efficacy of 77.36) against pumpkin powdery mildew at aconcentration of 100 μg·mL-1. In pumpkin leaves with/or without inoculation ofSphaerotheca fuliginea, osthol treatment induced the accumulation of chitinase andperoxidase and enhanced the transcription of chitinase gene in non-inoculated leaves. Thepotentiation of phenylalanine amonia-lyase activity in leaves by osthol application andfollowing inoculation was absent in that with inoculation or osthol treatment, indicatingthat induced PAL in osthol-pretreated plants was inoculation-mediated. In conclusion, thisnatural compound could induce resistance response in the plant against powdery mildew.
Crystallization and Characterization of Galdieria sulphuraria RUBISCO in Two Crystal Forms: Structural Phase Transition Observed in P21 Crystal Form
Authors: Baranowski Michael , Stec Boguslaw
Published: October 2008

We have isolated ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCO)from the red algae Galdieria Sulphuraria. The protein crystallized in two different crystalforms, the I422 crystal form being obtained from high salt and the P21 crystal form beingobtained from lower concentration of salt and PEG. We report here the crystallization,preliminary stages of structure determination and the detection of the structural phasetransition in the P21 crystal form of G. sulphuraria RUBISCO. This red algae enzymebelongs to the hexadecameric class (L8S8) with an approximate molecular weight 0.6MDa.The phase transition in G. sulphuraria RUBISCO leads from two hexadecamers to a singlehexadecamer per asymmetric unit. The preservation of diffraction power in a phasetransition for such a large macromolecule is rare.
Threading Cyclodextrins in Chloroform: A [2]Pseudorotaxane
Authors: Gattuso Giuseppe , Gargiulli Claudia , Parisi Melchiorre F.
Published: October 2008

The unusual self-assembly in chloroform of a novel cyclodextrin-based [2]pseudorotaxane, composed of heptakis-2,6-di-O-methyl-3-O-acetyl-β-cyclodextrin and a viologen-containing linear component, is reported.
The Molecular Structure and Vibrational Spectrum of 6-bromo-8-thia-1,4-epoxybicyclo[4.3.0]non-2-ene
Authors: Arslan Hakan , Demircan Aydın
Published: October 2008

Geometric parameters and FT-IR spectrum of 6-bromo-8-thia-1,4-epoxybicyclo[4.3.0]non-2-ene were computed by the HF, B3LYP, B3PW91 andmPW1PW91 methods in conjunction with the 6-31G(d,p) basis set. The calculated IRspectra are in a good agreement with the observed FT-IR spectrum. A general betterperformance of B3LYP, B3PW91 and mPW1PW91 versus HF was quantitativelycharacterized by using PAVF 1.0 program. Optimal uniform scaling factors calculated forthe title compound are 0.8952, 0.9552, 0.9520 and 0.9456 for HF, B3LYP, B3PW91 andMPW1PW91 methods, respectively.
Antiproliferation of Hepatoma Cell and Progression of Cell Cycle as Affected by Isoflavone Extracts from Soybean Cake
Authors: Kao Tsai-Hua , Huang Rwei-Fen S. , Chen Bing-Huei
Published: October 2008

The objectives of this study were to isolate various isoflavone fractions andextracts from soybean cake by preparative column chromatography and compare themwith isoflavone standards with regards to inhibition of HepG2 cancer cell proliferation.Four fractions, including malonylglucoside, glucoside, acetylglucoside and aglycone, andtwo isoflavone extracts, ISO-1 and ISO-2, were collected for evaluation. MTT test resultsshowed that most treatments were slightly protective against HepG2 cell growth at a lowdose of isoflavone (5 and 10 μg/mL). However, at elevated concentration of isoflavone(20-50 μg/mL), both aglycone and acetylglucoside fractions as well as a mixture ofisoflavone standards were the most effective in inhibition, demonstrating a possiblesynergistic phenomenon. Genistein showed a better retardation effect than daidzein. Forcell cycle analysis, both aglycone and acetylglucoside fractions and a mixture ofisoflavone standards exhibited a high G2/M ratio, correlating well with the result of MTTtest. The presence of some other functional components in soybean cake like saponinsand phenolic compounds may also play a vital role in inhibiting HepG2 cell growth.
The Signaling Cascades of Ginkgolide B-Induced Apoptosis in MCF-7 Breast Cancer Cells
Authors: Chan Wen-Hsiung
Published: October 2008

Ginkgolide B, the major active component of Ginkgo biloba extracts, can bothstimulate and inhibit apoptotic signaling. Here, we demonstrate that ginkgolide B caninduce the production of reactive oxygen species in MCF-7 breast cancer cells, leading toan increase in the intracellular concentrations of cytoplasmic free Ca2+ and nitric oxide(NO), loss of mitochondrial membrane potential (MMP), activation of caspase-9 and -3,and increase the mRNA expression levels of p53 and p21, which are known to be involvedin apoptotic signaling. In addition, prevention of ROS generation by pretreatment withN-acetyl cysteine (NAC) could effectively block intracellular Ca2+ concentrationsincreases and apoptosis in ginkgolide B-treated MCF-7 cells. Moreover, pretreatment withnitric oxide (NO) scavengers could inhibit ginkgolide B-induced MMP change andsequent apoptotic processes. Overall, our results signify that both ROS and NO playedimportant roles in ginkgolide B-induced apoptosis of MCF-7 cells. Based on these studyresults, we propose a model for ginkgolide B-induced cell apoptosis signaling cascades inMCF-7 cells.
Polyphenolic Profile and Antioxidant Activities of Oolong Tea Infusion under Various Steeping Conditions
Authors: Su Xinguo , Duan Jun , Jiang Yueming , Duan Xuewu , Chen Feng
Published: October 2008

The phenolic profile and antioxidant activities of oolong tea extract wereinvestigated after tea was steeped in 90 or 100 oC water for 3 or 10 min. The extractionyield increased with increasing temperature and extended steeping time. However, highertemperature and longer time (100 oC water for 10 min) led to loss of phenolics. Theaqueous extract of oolong tea (AEOT) at 100 oC for 3 min exhibited the strongestantioxidant activity. The major polyphenolic components of the AEOT were identified as(-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCG) and (-)-epicatechin-3-gallate (ECG). The two major catechins (EGC and EGCG) in the tea infusion contributedsignificantly to the investigated antioxidant activities [i.e., the 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging and superoxide radical scavengingactivities] with high correlation values in r = 0.9486 and 0.9327 for the EGC and r =0.9592 and 0.8718 for the EGCG, respectively.
Structural Characteristics and Reactivity Relationships of Nitroaromatic and Nitramine Explosives – A Review of Our Computational Chemistry and Spectroscopic Research
Authors: Qasim Mohammad M. , Moore Brett , Taylor Lyssa , Gorb Leonid , Leszczynski Jerzy , Honea Patricia
Published: October 2008

Although much has been discovered, discussed and written as to problems ofcontamination by various military unique compounds, particularly by the nitrogen basedenergetics (NOCs), remaining problems dictate further evaluation of actual and potentialrisk to the environment by these energetics and their derivatives and metabolites throughdetermination of their environmental impact—transport, fate and toxicity. This workcomprises an effort to understand structural relationships and degradation mechanisms ofcurrent and emerging explosives, including nitroaromatic; cyclic and cage cyclic nitramine;and a nitrocubane. This review of our computational chemistry and spectroscopic researchdescribes and compares competitive degradation mechanisms by free radical oxidative,reductive and alkali hydrolysis, relating them, when possible, to environmental risk.
Elevation of Inducible Nitric Oxide Synthase and Cyclooxygenase-2 Expression in the Mouse Brain after Chronic Nonylphenol Exposure
Authors: Zhang Yan-Qiu , Mao Zhen , Zheng Yuan-Lin , Han Bao-Ping , Chen Ling-Tong , Li Jing , Li Fei
Published: October 2008

The present study was performed to investigate the effects of chronic administration of nonylphenol (NP) on the expression of inflammation-related genes in the brains of mice. NP was given orally by gavages at 0, 50, 100, and 200 mg/kg/d. The expression of inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), was evaluated by immunohistochemistry and immunoblotting assays. The nitric oxide (NO) level and nitric oxide synthase (NOS) activity were also measured by biochemical analyses. The results showed that NP at a high dose (200 mg/kg/d) significantly increased the expression of iNOS and COX-2 in both the hippocampus and cortex. In parallel with the increase in iNOS expression, the NO level was significantly greater at the dose of 200 mg/kg/d, compared to the control. The activity of NOS was also increased in the brain of mice at the dose of 100 and 200 mg/kg/d. These findings demonstrate that NP may have the potential to induce the chronic inflammation or cause neurotoxicity in the mouse brain.
Schultz Index of Armchair Polyhex Nanotubes
Authors: Eliasi Mehdi , Salehi Nafiseh
Published: October 2008

The study of topological indices – graph invariants that can be used for describing and predicting physicochemical or pharmacological properties of organic compounds – is currently one of the most active research fields in chemical graph theory. In this paper we study the Schultz index and find a relation with the Wiener index of the armchair polyhex nanotubes TUV C6[2p; q]. An exact expression for Schultz index of this molecule is also found.
Aspergillus parasiticus crzA, Which Encodes Calcineurin Response Zinc-Finger Protein, Is Required for Aflatoxin Production under Calcium Stress
Authors: Chang Perng-Kuang
Published: October 2008

Two morphologically different Aspergillus parasiticus strains, one producing aflatoxins, abundant conidia but few sclerotia (BN9) and the other producing O-methylsterimatocystin (OMST), copious sclerotia but a low number of conidia (RH), were used to assess the role of crzA which encodes a putative calcium-signaling pathway regulatory protein. Under standard culture conditions, BN9ΔcrzA mutants conidiated normally but decreased slightly in radial growth, regardless of illumination conditions. RHΔcrzA mutants produced only conidia under light and showed decreased conidiation and delayed sclerotial formation in the dark. Regulation of conidiation of both A. parasiticus strains by light was independent of crzA. Increased concentrations of lithium, sodium, and potassium impaired conidiation and sclerotial formation of the RHΔcrzA mutants but they did not affect conidiation of the BN9ΔcrzA mutants. Vegetative growth and asexual development of both ΔcrzA mutants were hypersensitive to increased calcium concentrations. Calcium supplementation (10 mM) resulted in 3-fold and 2-fold decreases in the relative expression of the endoplasmic reticulum calcium ATPase 2 gene in the BN9 and RH parental strains, respectively, but changes in both ΔcrzA mutants were less significant. Compared to the parental strains, the ΔcrzA mutants barely produced aflatoxins or OMST after the calcium supplementation. The relative expression levels of aflatoxin biosynthesis genes, nor1, ver1, and omtA, in both ΔcrzA mutants were decreased significantly, but the decreases in the parental strains were at much lower extents. CrzA is required for growth and development and for aflatoxin biosynthesis under calcium stress conditions.
Detection of Diarrheic Shellfish Poisoning and Azaspiracids Toxins in Moroccan Mussels: Comparison of LC-MS Method with the Commercial Immunoassay Kit
Authors: Elgarch Adra , Vale Paulo , Rifai Saida , Fassouane Aziz
Published: October 2008

Diarrheic shellfish poisoning (DSP) is one of recurrent gastrointestinal illnesses in Morocco, resulting from consumption of contaminated shellfish. In order to develop a rapid and reliable technique for toxins detection, we have compared the results obtained by a commercial immunoassay-“DSP-Check” kit” with those obtained by LC-MS. Both techniques are capable of detecting the toxins in the whole flesh extract which was subjected to prior alkaline hydrolysis in order to detect simultaneously the esterified and non esterified toxin forms. The LC-MS method was found to be able to detect a high level of okadaic acid (OA), low level of dinophysistoxin-2 (DTX2), and surprisingly traces of azaspiracids 2 (AZA2) in mussels. This is the first report of a survey carried out for azaspiracids (AZP) contamination of shellfish harvested in the coastal areas of Morocco. The “DSP-Check” kit was found to detect quantitatively DSP toxins in all contaminated samples containing only OA provided that the parent toxins were within the range of detection and was not in an ester form. A good correlation was observed between the two methods when appropriate dilutions were performed. The immunoassay kit appeared to be more sensitive, specific and faster than LC-MS for determination of DSP in total shellfish extract.
Overexpression of the Pdx-1 Homeodomain Transcription Factor Impairs Glucose Metabolism in Cultured Rat Hepatocytes
Authors: Pillich Rudolf  Tito , Scarsella Gianfranco , Risuleo Gianfranco
Published: October 2008

The Pdx-1 transcription factor plays crucial functions both during pancreas development and in the adult β cells. Previous studies have indicated that ectopic Pdx-1 expression in liver or intestinal primary and immortalized cells is sufficient to promote activation of insulin gene expression. This work is focused on the molecular and physiological consequences of Pdx-1 overexpression in liver cells. We present evidence that Pdx-1 affects the level of expression of one of the four mammalian hexokinase isozymes. These are glucose phosphorylating enzymes involved in essential cellular functions such as glucose sensing, metabolic energy production and apoptosis. Specifically, our data show that over-expression of Pdx-1 in cultured hepatocytes is able to repress the expression of hexokinase 2 (Hxk 2) and the phenomenon is mediated via binding of Pdx-1 to a specific sequence on the Hxk 2 gene promoter. As a consequence, liver cells over-expressing Pdx-1 present interesting alterations concerning glucose metabolism.
Biosynthesis and Genetic Regulation of Proanthocyanidins in Plants
Authors: He Fei , Pan Qiu-Hong , Shi Ying , Duan Chang-Qing
Published: October 2008

Proanthocyanidins (PAs), also known as condensed tannins, are a group of polyphenolic secondary metabolites synthesized in plants as oligomers or polymers of flavan-3-ol units via the flavonoid pathway. Due to their structural complexity and varied composition, only in the recent years has the study on the biosynthesis and regulation of PAs in plants taken off, although some details of the synthetic mechanism remain unclear. This paper aims to summarize the status of research on the structures of PAs in plants, the genes encoding key enzymes of biosynthetic pathway, the transport factors, the transcriptional regulation of PA biosynthesis and the genetic manipulation of PAs. The problems of this field were also discussed, including the nature of the final “enzyme” which catalyzes the polymerization reaction of PAs and the possible mechanism of how the elementary units of flavanols are assembled in vivo.
Surface-Modified Gold Nanoparticles with Folic Acid as Optical Probes for Cellular Imaging
Authors: Tsai Shiao-Wen , Liaw Jiunn-Woei , Hsu Fu-Yin , Chen Yi-Yun , Lyu Mei-Jhih , Yeh Ming-His
Published: October 2008

In this study, we demonstrate that the uptake rate of the surface-modified gold nanoparticles (GNPs) with folic acid by specific cells can be increased significantly, if the membranes of these cells have sufficient folic-acid receptors. Two human breast cancer cell lines were studied; one is MDA-MB-435S cell, and the other T-47D cell. The expression of the folic acid receptors of the former is much higher than that of the latter. These cells were incubated with media containing bare GNPs or GNPs conjugated with folic acid individually. Due to the unique optical behavior (i.e. surface plasmon resonance) of GNPs, the uptake amount of GNPs by cells can be identified by using the laser scanning confocal microscopy. Our experiments show that the uptake amount of GNPs in MDAMB-435S cells is higher than that in T-47D cells for the same culture time, if the culture medium contains bare GNPs. Moreover, if the GNPs conjugated with folic acid are used for the culture, the uptake rate of GNPs by MDA-MB-435S cells is improved more. In contrast, the uptake rates of both GNPs are almost the same by T-47D cells. The phenomenon indicates that the uptake rate of GNPs can be improved via the ligand-receptor endocytosis, compared with the nonspecific endocytosis. Therefore, the uptake rate of GNPs conjugated with folic acid by MDA-MB-435S cells is higher than that of bare GNPs.
Modeling of an Optical Sensor Based on Whispering Gallery Modes (WGMs) on the Surface Guiding Layer of Glass Filaments
Authors: Tan Wei , Shi Lei , Chen Xianfeng
Published: October 2008

A ring-resonator-based refractive index sensor is proposed in this paper. Glass filaments with surface guiding layers created by ion exchange are crossed with a fiber taper to act as a ring resonator sensor. Theoretical simulation of the sensor response is proposed, and optimization of structural parameters including thickness and refractive index of the surface guiding layer and the diameter of the ring resonator for higher sensitivity is investigated. Results show that a detection limit of a variation of ~10-5RIU can be reached. Due to its simple fabrication and easy manipulation as well as good sensing performance, we believe such a micro-cavity sensor will find potential applications in high sensitivity optical sensing.