bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanistic Information on the Reversible Binding of NO to Mono‐ and Dinuclear FeIIComplexes of a Biomimetic S4N Ligand
Authors: Shaban Shaban Y. , van Eldik Rudi
Published: December 2009

Structural and mechanistic information on the binding of NO to mono‐ and dinuclear [FeII(S4NNEt2)] fragments as potential catalysts for the removal of NO from effluent gas streams have been obtained from concentration, temperature and pressure dependent kinetic measurements using stopped‐flow techniques. The results indicate that the steric and electronic structure only affect the rate but not the nature of the binding mechanism by which NO coordinates to the selected complexes. Therefore, the sterically hindered dinuclear complex [FeII(S4NNEt2)]2binds NO ca. eight times slower than the corresponding mononuclear complex [FeII(CH3OH)(S4NNEt2)]. Significantly negative ΔS#values were found for the binding of NO to both the mono‐ and dinuclear species, and are consistent with an associative mechanism. The negative volumes of activation observed for the binding of NO to both dinuclear [FeII(S4NNEt2)]2and mononuclear [FeII(CO)(S4NNEt2)] complexes further supports the operation of an associative mechanism. Structural studies on the [FeII(NO)(S4NNEt2)] complex indicate it to be six‐coordinate, low‐spin iron(II) with a neutral NO ligand.
Generation of Hollow MnSiO3 Nanostructures through the Solid‐State Reaction of Mn3O4 and Pd/PdO Nanocrystals Dimensionally Confined within Nanosized Silica Spheres
Authors: Shin Jongmin , Ha Tae‐Lin , Lee In Su
Published: December 2009

In the course of annealing Mn3O4 and Pd/PdO nanocrystals co‐encapsulated within a nanosized silica sphere under a reducing environment, we observed that the reduction of Mn3O4 into MnO was facilitated by the Pd/PdO nanocrystals. Successive annealing at high temperatures induced the MnO nanocrystals to react with the silica matrix, resulting in the formation of hollow nanostructures composed of a polycrystalline MnSiO3 shell.
The role of comprehensive chromatography in the characterization of edible oils and fats
Authors: Janssen Hans‐Gerd , Steenbergen Herrald , de Koning Sjaak
Published: December 2009

Chromatography has a very long history in the analysis of edible oils and fats. Hyphenations of two chromatographic methods, or couplings of a chromatographic separation technique with spectroscopic detection and identification devices, are used if the resolving power of the technique needs to be improved. More recently, the analytical benefits of comprehensive two‐dimensional (2D) chromatography, in its various operational modes, have been exploited by the oil and fat chromatographic community. In comprehensive 2D chromatography, the entire sample injected is subjected to two independent separation processes. In the present contribution, the principles of comprehensive 2D chromatography are briefly discussed. Next, the advantages of comprehensive separations for lipid analysis are illustrated using the concept of generic chromatographic applications. This concept distinguishes three generic reasons to apply chromatographic separations: target compound analysis, group‐type separation, and chromatographic fingerprinting. Examples of how comprehensive multi‐dimensional methods were successfully applied to solve problems in the edible oils and fats area are given. We believe that these multi‐dimensional techniques truly add new dimensions to oil and fat analysis, providing researchers in the area with novel tools for unraveling edible oil or fat samples with their complex compositions.
Effective Oxidation of Secondary Amines to Nitrones with Alkyl Hydroperoxides Catalysed by (Trialkanolaminato)titanium(IV) Complexes
Authors: Forcato Massimiliano , Mba Miriam , Nugent William A. , Licini Giulia
Published: December 2009

The effective catalytic oxidation of secondary amines to nitrones with alkyl hydroperoxides as the primary oxidants is described. The titanium alkoxide catalysts are protected from the water co‐product by the combined use of a tightly binding trialkanolamine ligand and molecular sieves. Nitrones can be obtained in high yields (up to 98 %) under homogeneous, anhydrous conditions and even in the absence of solvent. The reactions are fast (2–7 h) and good selectivity and complete conversion can be achieved with as little as 1 % catalyst.
Control of the Aggregation Properties of Tris(maltohexaose)‐Linked Porphyrins with an Alkyl Chain
Authors: Mikata Yuji , Sawaguchi Taichi , Kakuchi Toyoji , Gottschaldt Michael , Schubert Ulrich S. , Ohi Hiromi , Yano Shigenobu
Published: December 2009

A series of porphyrins with three maltohexaose units and one alkyl chain (ethyl, butyl, hexyl, decyl, and hexadecyl) has been synthesized. Aggregation properties were investigated by absorbance and circular dichroism (CD) spectra. These trismaltohexaosylated tetraphenylporphyrins exhibited high water solubility. Although these porphyrins exhibited sharp Soret bands in DMSO solution, the Soret band broadened in a concentration‐dependent manner in aqueous solution. This is the result of the aggregation of porphyrin molecules in aqueous solution. Interestingly, trismaltohexaosylated porphyrins with long alkyl chains of a certain length exhibited a broad Soret band in water without concentration dependency due to the stability of such aggregates. The CD spectra were silent in DMSO solution in all porphyrin derivatives, indicating that the maltohexaose moiety does not interact with the porphyrin chromophore in the monomeric state. However, in water, a splitting Cotton effect was observed at the Soret band. Intensity of this CD signal decreased as the length of the alkyl chain was extended. These observations show the formation of a chiral, face‐to‐face aggregate, in which the porphyrin rings are in close proximity to each other for short alkyl chain derivatives. The porphyrin derivatives with long alkyl chains exhibit edge‐to‐edge aggregation, where hydrophobic interaction of the alkyl chains separates the porphyrin chromophores.
Suzuki Coupling Reactions of (E)‐ and (Z)‐Chloroenynes with Boronic Acids: Versatile Access to Functionalized 1,3‐Enynes
Authors: Tikad Abdellatif , Hamze Abdallah , Provot Olivier , Brion Jean‐Daniel , Alami Mouâd
Published: December 2009

A stereoselective, palladium‐catalyzed, cross‐coupling reaction between chloroenynes 4 and boronic acids was successfully developed. This procedure is general and provides desired functionalized enynes 1 in high yields. The scope and limitations of this new reaction are described.
Biotechnological conversions of bio‐diesel‐derived crude glycerol by Yarrowia lipolytica strains
Authors: André Axel , Chatzifragkou Afroditi , Diamantopoulou Panagiota , Sarris Dimitris , Philippoussis Antonios , Galiotou‐Panayotou Maria , Komaitis Michael , Papanikolaou Seraphim
Published: December 2009

In the present report, crude glycerol, waste discharged from bio‐diesel production, was used as carbon substrate for three natural Yarrowia lipolytica strains (LFMB 19, LFMB 20 and ACA‐YC 5033) during growth in nitrogen‐limited submerged shake‐flask experiments. In media with initial glycerol concentration of 30 g/L, all strains presented satisfactory microbial growth and complete glycerol uptake. Although culture conditions favored the secretion of citric acid (and potentially the accumulation of storage lipid), for the strains LFMB 19 and LFMB 20, polyol mannitol was the principal metabolic product synthesized (maximum quantity 6.0 g/L, yield 0.20–0.26 g per g of glycerol consumed). The above strains produced small quantities of lipids and citric acid. In contrast, Y. lipolytica ACA‐YC 5033 produced simultaneously higher quantities of lipid and citric acid and was further grown on crude glycerol in nitrogen‐limited experiments, with constant nitrogen and increasing glycerol concentrations (70–120 g/L). Citric acid and lipid concentrations increased with increment of glycerol; maximum total citric acid 50.1 g/L was produced (yield 0.44 g per g of glycerol) while simultaneously 2.0 g/L of fat were accumulated inside the cells (0.31 g of lipid per g of dry weight). Cellular lipids were mainly composed of neutral fraction, the concentration of which substantially increased with time. Moreover, in any case, the phospholipid fraction was more unsaturated compared with total and neutral lipids, while at the early growth step, microbial lipid was more rich in saturated fatty acids (e.g. C16:0 and C18:0) compared with the stationary phase.
Light penetration into Clarens sandstone and implications for deterioration of San rock art
Authors: Hall Kevin , Meiklejohn Ian , Sumner Paul , Arocena Joselito
Published: December 2009

In respect to the weathering of cave art exposed to the sun, cognizance has yet to be taken of the modified thermal conditions and the potential for endolithic biotic activity where the art is located on a light‐transmissive lithology. Where light penetrates rock, the light‐to‐heat transfer is not solely at the surface, and this leads to a thermal gradient that is different from where the paintings are located (and all transfer is at the surface). Light values of up to 200 W/m2 were recorded at 0.5 mm depth and up to 100 W/m2 at 1mm depth in the dry sandstone; rock moisture data showed that at this site the rock remained dry irrespective of atmospheric conditions. The light penetration means that there can be rapid and large subsurface thermal fluctuations contemporaneous with those at the rock surface, and that the thermal gradient is not as steep (approximately 1°C/mm in the surficial part of the rock) as where light‐to‐heat transfer is solely at the surface. Further, the presence of subsurface photosynthetically active radiation can (potentially) facilitate colonization by endolithic organisms. Here, as part of a study of the weathering of San rock art on sandstone in southern Africa, a first attempt is made to monitor the extent of light penetration and the resulting thermal conditions in the outer few millimeters of the sandstone. © 2009 Wiley Periodicals, Inc.
Bronze Age paleohydrography of the southern Venetian Plain
Authors: Piovan Silvia , Mozzi Paolo , Stefani Cristina
Published: December 2009

The Bronze Age paleohydrography of the distal Adige and Po alluvial plain (northeastern Italy) is notable for its relations with protohistoric human activities in this area. This paper regards the stratigraphy and petrography of the Saline–Cona alluvial ridge, upon which the Saline, Sarzano, and Cantarana Bronze Age sites lie, and the petrography of Fratta alluvial ridge, upon which the Frattesina complex (Bronze–Iron Age) lies. Sand analyses indicate the Po River as the source for sediments underlying the alluvial ridge that runs through Fratta Polesine, Rovigo, Sarzano, and Cona. Radiometric ages indicate that the branch of the Saline–Cona ridge was formed by the Po River between the second half of the 3rd millennium B.C. and the end of 2nd millennium B.C. This ridge represents the maximum northward expansion of the Po alluvial system, through the same area of coastal plain crossed by the Adige and Brenta paleochannels. This paleohydrographic setting implies that fluvial connections between the Central Po Plain settlements, the Venetian Plain and Alps were relatively less complex in the Early and Middle Bronze Age than in the Late Bronze Age, when the terminal reach of the Po River was separated by the Adige River by hundreds of km2 of swampy terrain. © 2009 Wiley Periodicals, Inc.
Two New Homo‐aro‐cholestane Glycosides and a New Cholestane Glycoside from the Roots and Rhizomes of Paris polyphylla var. pseudothibetica
Authors: Xiao Cao‐Mao , Huang Jing , Zhong Xue‐Mei , Tan Xiao‐Yan , Deng Peng‐Chi
Published: December 2009

Two new homo‐aro‐cholestane glycosides and a new cholestane glycoside, along with three known saponins, were isolated from the 95% EtOH extract of the roots and rhizomes of Paris polyphylla var. pseudothibetica. The structures of the new compounds were elucidated as 3β‐O‐{α‐L‐rhamnopyranosyl‐(1→4)‐α‐L‐rhamnopyranosyl‐(1→4)‐[α‐L‐rhamnopyranosyl‐(1→2)]}‐β‐D‐glucopyranosylhomo‐aro‐cholest‐5‐ene‐26‐O‐β‐D‐glucopyranoside (parispseudoside A, 1), 3β‐O‐α‐L‐rhamnopyranosyl‐(1→2)‐β‐D‐glucopyranosylhomo‐aro‐cholest‐5‐ene‐26‐O‐β‐D‐glucopyranoside (parispseudoside B, 2), and (25R)‐3β‐O‐{α‐L‐rhamnopyranosyl‐(1→4)‐α‐L‐rhamnopyranosyl‐(1→4)‐[α‐L‐rhamnopyranosyl‐(1→2)]}‐β‐D‐glucopyranosyl‐cholesta‐5,17(20)‐diene‐16,22‐dione‐26‐O‐β‐D‐glucopyranoside (parispseudoside C, 3) by spectroscopic methods, including 1D‐ and 2D‐NMR, and MS experiments, as well as chemical evidences.
C21 Steroidal Glycosides from Cynanchum wilfordii
Authors: Xiang Wen‐Juan , Ma Lei , Hu Li‐Hong
Published: December 2009

Eight new C21 steroidal glycosides, named wilfosides A–H (1–8, resp.), along with one known compound wilfoside KIN (9), were isolated from the roots of Cynanchum wilfordii. The structures of the new glycosides were determined on the basis of spectroscopic analysis, including 1D‐ and 2D‐NMR, and ESI‐MS techniques, as well as by comparison of the spectral data with those of related compounds.
Two New Guaiane Sesquiterpenes from the Fruits of Daucus carota
Authors: Yi Tao , Zhang Lin , Fu Hong‐Wei , Yang Shi‐Lin , Tian Jing‐Kui
Published: December 2009

Two new sesquiterpenes, 11‐(acetyloxy)torilolone (1) and 1β‐hydroxytorilolone (2) were obtained from the fruits of Daucus carota. Their structures were elucidated on the basis of various spectroscopic analyses and chemical evidence.
Three New ent‐Trachylobane Diterpenoids from Co‐cultures of the Calli of Trewia nudiflora and Fusarium sp. WXE
Authors: Wu Xin , Lu Chun‐Hua , Shen Yue‐Mao
Published: December 2009

Five diterpenoids, including three new ent‐trachylobane diterpenoids, i.e., (3α)‐3‐hydroxy‐ent‐trachylobane‐17,19‐dioic acid 19‐methyl ester (1), ent‐trachylobane‐17,19‐dioic acid 19‐methyl ester (2), ent‐trachylobane‐17,19‐dioic acid (3), and two known atisane‐type ones, i.e., (16α)‐16,17‐dihydroxy‐ent‐atisan‐19‐oic acid methyl ester (4), and 17‐hydroxy‐ent‐atisan‐19‐oic acid methyl ester (5), were isolated from the co‐culture extract of the calli of Trewia nudiflora and its endophytic fungus Fusarium sp. WXE. Their structures were elucidated by spectroscopic analyses, including 1D‐ and 2D‐NMR experiments, and HR‐Q‐TOF mass spectrometry. The antitumor and antibacterial properties of the new compounds were evaluated.
Nucleotides. Part LXXV
Authors: Maier Thomas , Pfleiderer Wolfgang
Published: December 2009

The reactivity of the 2′‐deoxy‐N4‐(phenoxycarbonyl)cytidine derivatives 3 and 4 with aromatic amines was studied to form new types of urea derivatives (see 5–10). On the same basis, labeling of 3 and 4 with 5‐aminofluorescein (14) was achieved to give the conjugates 15 and 17, respectively (Scheme 1). Treatment of 17 with 2‐(4‐nitrophenyl)ethanol in a Mitsunobu reaction led to double protection of the fluorescein moiety (→18) and desilylation yielded 19. Dimethoxytritylation (→20) and subsequent phosphitylations afforded the new building blocks 21 and 22. Synthesis of the fully protected trimer 28 was achieved by condensation of 21 with 23 to 26 which after detritylation (→27) was coupled with 25 to give 28 (Scheme 2). Deprotection of all blocking groups was performed with 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in one step to give 29. The synthesis of the decamer 5′‐d(CFluCCG GCC CGC)‐3′ (33) started from 30 which was attached to the solid support and then elongated with 31, 32, and 22 at the 5′‐terminal end (CFlu=deprotected phosphate derivative of 22). Hybridization with the complementary oligomer 5′‐d(G GGC CGG GCG)‐3′ (34) showed the influence of the fluorescein label on the stability of the duplex.
A New Iridoid Alkaloid from the Flowers of Plumeria rubra L. cv. acutifolia
Authors: Ye Guan , Li Zhi‐Xiong , Xia Guang‐Xin , Peng Hua , Sun Zhao‐Lin , Huang Cheng‐Gang
Published: December 2009

A new iridoid alkaloid containing a spirolactone unit, plumericidine (1), was isolated from the flowers of Plumeria rubra L. cv. Acutifolia. Its structure was elucidated by spectroscopic evidence and confirmed by X‐ray diffraction crystallography. Its anticancer and antiviral activities were evaluated, but found to be insignificant.
Thermal [2+3]‐Cycloadditions of trans‐1‐Methyl‐2,3‐diphenylaziridine with CS and CC Dipolarophiles: An Unexpected Course with Dimethyl Dicyanofumarate
Authors: Mlostoń Grzegorz , Urbaniak Katarzyna , Domagała Małgorzata , Pfitzner Arno , Zabel Manfred , Heimgartner Heinz
Published: December 2009

The thermal reaction of trans‐1‐methyl‐2,3‐diphenylaziridine (trans‐1a) with aromatic and cycloaliphatic thioketones 2 in boiling toluene yielded the corresponding cis‐2,4‐diphenyl‐1,3‐thiazolidines cis‐4 via conrotatory ring opening of trans‐1a and a concerted [2+3]‐cycloaddition of the intermediate (E,E)‐configured azomethine ylide 3a (Scheme 1). The analogous reaction of cis‐1a with dimethyl acetylenedicarboxylate (5) gave dimethyl trans‐2,5‐dihydro‐1‐methyl‐2,5‐diphenylpyrrole‐3,4‐dicarboxylate (trans‐6) in accord with orbital‐symmetry‐controlled reactions (Scheme 2). On the other hand, the reactions of cis‐1a and trans‐1a with dimethyl dicyanofumarate (7a), as well as that of cis‐1a and dimethyl dicyanomaleate (7b), led to mixtures of the same two stereoisomeric dimethyl 3,4‐dicyano‐1‐methyl‐2,5‐diphenylpyrrolidine‐3,4‐dicarboxylates 8a and 8b (Scheme 3). This result has to be explained via a stepwise reaction mechanism, in which the intermediate zwitterions 11a and 11b equilibrate (Scheme 6). In contrast, cis‐1,2,3‐triphenylaziridine (cis‐1b) and 7a gave only one stereoisomeric pyrrolidine‐3,4‐dicarboxylate 10, with the configuration expected on the basis of orbital‐symmetry control, i.e., via concerted reaction steps (Scheme 10). The configuration of 8a and 10, as well as that of a derivative of 8b, were established by X‐ray crystallography.
NMR‐Solution Structures and Affinities for the Human Somatostatin G‐Protein‐Coupled Receptors hsst1–5 of CF3 Derivatives of Sandostatin® (Octreotide)
Authors: Seebach Dieter , Widmer Hans , Capone Stefania , Ernst Richard , Bremi Tobias , Kieltsch Iris , Togni Antonio , Monna Dominique , Langenegger Daniel , Hoyer Daniel
Published: December 2009

The previously reported (Helv. Chim. Acta 2008, 91, 2035) derivatives of octreotide (1) with a (CF3)‐Trp substitution, i.e., 3, and with open‐chain structures, i.e., 2, 4, and 5, have been tested for their affinities to hsst1–5 receptors and subjected to a detailed NMR analysis. Their affinities vary from 15 nM to 5 μM, as compared to 0.6 nM to 0.8 μM for octreotide itself (Table 1). This decreased bioactivity may have had to be expected for the open‐chain compounds 4 and 5; possible reasons for this decrease in the case of CF3 derivative of octreotide, 3, are discussed. NMR Analysis (Tables 2 and 3) provides evidence for increased dynamics of all new derivatives 2–5. The dynamics of the octreotide molecule 1 was analyzed by (natural‐abundance) longitudinal 13C‐T1‐relaxation time measurements (Table 4), from which the conclusion is drawn that the backbone of the macrocycle is rather rigid on the time scale of this method.
Synthesis and High‐Resolution NMR Structure of a β3‐Octapeptide with and without a Tether Introduced by Olefin Metathesis
Authors: Ebert Marc‐Olivier , Gardiner James , Ballet Steven , Abell Andrew D. , Seebach Dieter
Published: December 2009

Bridging between (i)‐ and (i+3)‐positions in a β3‐peptide with a tether of appropriate length is expected to prevent the corresponding 314‐helix from unfolding (Fig. 1). The β3‐peptide H‐β3hVal‐β3hLys‐β3hSer(All)‐β3hPhe‐β3hGlu‐β3hSer(All)‐β3hTyr‐β3hIle‐OH (1; with allylated βhSer residues in 3‐ and 6‐position), and three tethered β‐peptides 2–4 (related to 1 through ring‐closing metathesis) have been synthesized (solid‐phase coupling, Fmoc strategy, on chlorotrityl resin; Scheme). A comparative CD analysis of the tethered β‐peptide 4 and its non‐tethered analogue 1 suggests that helical propensity is significantly enhanced (threefold CD intensity) by a (CH2)4 linker between the β3hSer side chains (Fig. 2). This conclusion is based on the premise that the intensity of the negative Cotton effect near 215 nm in the CD spectra of β3‐peptides represents a measure of ‘helical content’. An NMR analysis in CD3OH of the two β3‐octapeptide derivatives without (i.e., 1) and with tether (i.e., 4; Tables 1–6, and Figs. 4 and 5) provided structures of a degree of precision (by including the complete set of side chain–side chain and side chain–backbone NOEs) which is unrivaled in β‐peptide NMR‐solution‐structure determination. Comparison of the two structures (Fig. 5) reveals small differences in side‐chain arrangements (separate bundles of the ten lowest‐energy structures of 1 and 4, Fig. 5, A and B) with little deviation between the two backbones (superposition of all structures of 1 and 4, Fig. 5, C). Thus, the incorporation of a CH2O(CH2)4OCH2 linker between the backbone of the β3‐amino acids in 3‐ and 6‐position (as in 4) does accurately constrain the peptide into a 314‐helix. The NMR analysis, however, does not suggest an increase in the population of a 314‐helical backbone conformation by this linkage. Possible reasons for the discrepancy between the conclusion from the CD spectra and from the NMR analysis are discussed.
Effects of storm flow samplings on the evaluation of inorganic nitrogen and sulfate budgets in a small forested watershed
Authors: Chiwa Masaaki , Ide Jun'ichiro , Maruno Ryoko , Higashi Naoko , Otsuki Kyoichi
Published: December 2009

To investigate the effects of storm flow samplings on the evaluation of DIN and SO42− budgets, we conducted storm flow samplings and discrete interval (weekly) samplings of stream water, throughfall, and stemflow. This investigation lasted for three years and took place in a small forested watershed in western Japan. Annual exports were calculated by the sum of the load (ΣLtotal)‐ sum of the discharge (ΣQtotal) relationships obtained by storm flow samplings. These were then compared to calculated ones that were based on LQ relationships obtained by discrete interval sampling. The results of discrete interval sampling showed that the relationships of DIN or SO42− concentration to the discharge amount found in stream water differed from those of storm flow sampling. This was especially notable in years with higher annual precipitation and subsequent higher annual discharges. Also, exports of DIN and SO42− during storm flow periods accounted for 83% and 78% of annual exports on 3‐year averages, respectively. These results confirmed that storm flow samplings are essential for estimating annual exports of DIN and SO42−. Annual exports that were calculated based on just discrete interval sampling (46% and 17%, respectively) overestimated DIN and SO42− from discrete interval and storm flow samplings on a 3‐year average. These overestimates were pronounced in years of higher discharge, and critically affected the rates of net‐retention or export of DIN and SO42−. The relationship of smaller input than output of DIN was reversed if storm flow sampling was included. Copyright © 2009 John Wiley & Sons, Ltd.
Effects of sample and grid size on the accuracy and stability of regression‐based snow interpolation methods
Authors: Moreno J. Ignacio López , Latron J. , Lehmann A.
Published: December 2009

This work analyses the responses of four regression‐based interpolation methods for predicting snowpack distribution to changes in the number of data points (sample size) and resolution of the employed digital elevation model (DEM). For this purpose, we used data obtained from intensive and random sampling of snow depth (991 measurements) in a small catchment (6 km2) in the Pyrenees, Spain. Linear regression, classification trees, generalized additive models (GAMs), and a recent method based on a correction made by applying tree classification to GAM residuals were used to calculate snow‐depth distribution based on terrain characteristics under different combinations of sample size and DEM spatial resolution (grid size).

The application of a tree classification to GAM residuals yielded the highest accuracy scores and the most stable models. The other tested methods yielded scores with slightly lower accuracy and varying levels of robustness under different conditions of grid and sample size. The accuracy of the model predictions declined with decreasing resolution of DEMs and sample size; however, the sensitivities of the models to the number of data points showed threshold values, which has implications (when planning fieldwork) for optimizing the relation between the effort expended in gathering data and the quality of the results. Copyright © 2009 John Wiley & Sons, Ltd.
Gastrin suppresses the interdependent expression of p16 and anion exchanger 1 favoring growth inhibition of gastric cancer cells
Authors: Tian Hua , Zhang Ning , Suo Wen‐Hao , Wang Ting , Song Ling‐Jun , Wu Jun , Liu Qiang , Shen Wei‐Wei , Fu Guo‐Hui
Published: December 2009

Our previous studies demonstrated that expression and interaction of p16 with anion exchanger 1 (AE1) in gastric cancer cells is correlated with progression and shorter survival of the cancer. In this article, the effects of gastrin on p16 and AE1 and its implication in prevention and treatment of gastric cancer were studied by molecular biology techniques, animal experiment and clinical analysis. The results showed that expression of p16 in human gastric body carcinoma was downregulated along with the progression of the cancer, suggesting the reverse correlations between gastrin and p16 in vivo. Further experiments indicated that gastrin suppressed the expression of p16 via the p16 promoter and thereafter resulted in the degradation of AE1 in gastric cancer cells. Silencing of AE1 or p16 significantly inhibited the proliferation of the cancer cells. Using a xenograft tumor model in nude mice, we showed that experimental systemic hypergastrinemia induced by the administration of omeprazole led to decreased expression of AE1 and p16 as well as to a marked growth inhibition of SGC7901 tumors. It is concluded that a moderate plasma gastrin level is beneficial to the growth inhibition of gastric cancer by suppressing the expression of AE1 and p16. This finding may have an important implication for the prevention and treatment of cancers arise in the gastric antrum.
Accurate conformation‐dependent molecular electrostatic potentials for high‐throughput in silico drug discovery
Authors: Puranen J. Santeri , Vainio Mikko J. , Johnson Mark S.
Published: December 2009

The atom‐centered partial charges‐approximation is commonly used in current molecular modeling tools as a computationally inexpensive alternative to quantum mechanics for modeling electrostatics. Even today, the use of partial charges remains useful despite significant advances in improving the efficiency of ab initio methods. Here, we report on new parameters for the EEM and SFKEEM electronegativity equalization‐based methods for rapidly determining partial charges that will accurately model the electrostatic potential of flexible molecules. The developed parameters cover most pharmaceutically relevant chemistries, and charges obtained using these parameters reproduce the B3LYP/cc‐pVTZ reference electrostatic potential of a set of FDA‐approved drug molecules at best to an average accuracy of 13 ± 4 kJ mol−1; thus, equipped with these parameters electronegativity equalization‐based methods rival the current best non‐quantum mechanical methods, such as AM1‐BCC, in accuracy, yet incur a lower computational cost. Software implementations of EEM and SFKEEM, including the developed parameters, are included in the conformer‐generation tool BALLOON, available free of charge at http://web.abo.fi/fak/mnf/bkf/research/johnson/software.php. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Describing electron correlation effects in the framework of the elongation method—Elongation‐MP2: Formalism, implementation and efficiency
Authors: Makowski Marcin , Korchowiec Jacek , Gu Feng Long , Aoki Yuriko
Published: December 2009

The extension of the elongation method into description of electron correlation effects at ab intio level is presented. The formalism and implementation of the elongation‐MP2 methodology is discussed. The results of calculations for model systems are presented to illustrate efficiency and accuracy of the method. Directions of the further development are highlighted. © 2009 Wiley Periodicals, Inc. J Comput Chem, 2010
Parents and peers as providers of support in adolescents' social network: a developmental perspective
Authors: del Valle Jorge F. , Bravo Amaia , López Mónica
Published: December 2009

The authors carried out an assessment of social support networks with a sample of 884 Spanish adolescents aged 12 to 17. The main goal was to analyze the development of the figures of parents and peers as providers of social support in the two basic dimensions of emotional and instrumental support. In peers, they distinguished between the contexts from which they came (school, associations, and friends from the community) to observe whether there were different tendencies. The results of the MANOVA indicate significant effects on both dimensions for the factors age, provider, and interaction between the two. The authors conclude that the tendencies for decline in the provision of support from parents and the corresponding increase in support from peers during adolescence are different for each dimension, and also for the different types of friends, according to context. Parents maintain a good level of instrumental support, but not of emotional support. © 2009 Wiley Periodicals, Inc.
Tobacco sales in community pharmacies: remote decisions and demographic targets
Authors: Morton Cory M. , Peterson N. Andrew , Schneider John E. , Smith Brian J. , Armstead Theresa L.
Published: December 2009

This study applied multilevel modeling procedures with data from 678 community pharmacies and 382 residential census tracts in a Midwestern U.S. state to determine if two sets of variables: retail type (e.g., remotely owned, independently owned) and population demographics of the tracts in which outlets were located were associated with retail tobacco availability in community pharmacies. Data were derived from three archival sources: listings of all retailers in Iowa who obtained tobacco licenses in year 2003; all pharmacies registered with the Iowa Board of Pharmacy in 2003; and year 2000 census data. Refuting previous research, multilevel logistic regression results of this study demonstrate that population demographics, as well as retail type, significantly predict whether a community pharmacy sold tobacco. Pharmacies selling tobacco were more likely to be remotely owned outlets and located in areas with higher percentages of African American residents and higher median income. Implications for environmentally focused prevention interventions are discussed. © 2009 Wiley Periodicals, Inc.
Toll‐like receptor 2‐mediated peptidoglycan uptake by immature intestinal epithelial cells from apical side and exosome‐associated transcellular transcytosis
Authors: Bu Heng‐Fu , Wang Xiao , Tang Yi , Koti Viola , Tan Xiao‐Di
Published: December 2009

Peptidoglycan (PGN) is a potent immune adjuvant derived from bacterial cell walls. Previous investigations suggest that intestinal epithelium may absorb PGN from the lumen. Nonetheless, how PGN is taken up and crosses intestinal epithelium remains largely unclear. Here, we first characterized PGN transport in vitro using IEC‐18 and HT29‐CL19A cells, which represent less mature epithelial cells in intestinal crypts. With fluorescent microscopy, we visualized internalization of dual‐labeled PGN by enterocytes. Engulfed PGN was found to form a complex with PGN recognition protein‐3, which may facilitate delivering PGN in vivo. Utilizing electronic microscopy, we revealed that uptake of apical PGN across intestinal epithelial monolayers was involved in phagocytosis, multivesicular body formation, and exosome secretion. We also studied transport of PGN using the transwell system. Our data indicated that apically loaded PGN was exocytosed to the basolateral compartment with exosomes by HT29‐CL19A cells. The PGN‐contained basolateral exosome extracts induced macrophage activation. Through gavaging mice with labeled PGN, we found that luminal PGN was taken up by columnar epithelial cells in crypts of the small intestine. Furthermore, we showed that pre‐confluent immature but not post‐confluent mature C2BBe1 cells engulfed PGN via a toll‐like receptor 2‐dependent manner. Together, our findings suggest that (1) crypt‐based immature intestinal epithelial cells play an important role in transport of luminal PGN over the intestinal epithelium; and (2) luminal PGN is transcytosed across intestinal epithelia via a toll‐like receptor 2‐mediated phagocytosis‐multivesicular body‐exosome pathway. The absorbed PGN and its derivatives may facilitate maintenance of intestinal immune homeostasis. J. Cell. Physiol. 222: 658–668, 2010. © 2009 Wiley‐Liss, Inc.
Are induced pluripotent stem cells the future of cell‐based regenerative therapies for spinal cord injury?
Authors: Salewski Ryan P.F. , Eftekharpour Eftekhar , Fehlings Michael G.
Published: December 2009

Despite advances in medical and surgical care, current clinical therapies for spinal cord injury (SCI) are limited. During the last two decades, the search for new therapies has been revolutionized by the discovery of stem cells, inspiring scientists and clinicians to search for stem cell‐based reparative approaches for many disorders, including neurotrauma. Cell‐based therapies using embryonic and adult stem cells in animal models of these disorders have provided positive outcome results. However, the availability of clinically suitable cell sources for human application has been hindered by both technical and ethical issues. The recent discovery of induced pluripotent stem (iPS) cells holds the potential to revolutionize the field of regenerative medicine by offering the option of autologous transplantation, thus eliminating the issue of host rejection. Herein, we will provide the rationale for the use of iPS cells in SCI therapies. In this review, we will evaluate the recent advancements in the field of iPS cells including their capacity for differentiation toward neural lineages that may allow iPS cells transplantation in cell‐based therapy for spinal cord repair. J. Cell. Physiol. 222: 515–521, 2010. © 2009 Wiley‐Liss, Inc.
Human cleft lip and palate fibroblasts and normal nicotine‐treated fibroblasts show altered in vitro expressions of genes related to molecular signaling pathways and extracellular matrix metabolism
Authors: Baroni Tiziano , Bellucci Catia , Lilli Cinzia , Pezzetti Furio , Carinci Francesco , Lumare Eleonora , Palmieri Annalisa , Stabellini Giordano , Bodo Maria
Published: December 2009

Nonsyndromic cleft lip with or without cleft palate (CLP) is a frequent craniofacial malformation caused by both genetic and environmental factors. Maternal smoking during pregnancy is a known risk factor, due to the teratogenic role of nicotine. To assess and compare the impact of CLP and nicotine, we studied the quantitative expression of genes involved in signaling pathways and extracellular matrix (ECM) metabolism in human normal nicotine‐treated (NicN) and CLP fibroblasts compared to normal control (CTRL) cells. Palatal fibroblast cultures from seven CLP children and seven age‐matched CTRL subjects were established and subconfluent cells incubated for 24 h without (CTRL and CLP fibroblasts) or with (NicN fibroblasts) 0.6 mM nicotine. Gene expressions were analyzed by real‐time quantitative PCR. For the first time, a regulated cholinergic signaling in our human fibroblasts in vitro was demonstrated. Members of TGF‐beta, retinoic acid (RA), and GABA‐ergic signaling systems were also differently regulated. Among the ECM genes, fibronectin, syndecan, integrin α2, and MMP13 genes were concordantly modulated, while integrin β5, and decorin genes were discordantly modulated. Interestingly, nicotine treatment regulated gene expressions of CD44 and CLPTM1, two candidate genes for CLP. Our findings show a positive association between nicotine treatment and CLP phenotype. Results suggest that nicotine deranges normal palate development, which might contribute to the development of a CLP malformative phenotype, through the impairment of some important signaling systems and ECM composition. J. Cell. Physiol. 222: 748–756, 2010. © 2009 Wiley‐Liss, Inc.
Methylation analysis by DNA immunoprecipitation
Authors: Thu Kelsie L. , Pikor Larissa A. , Kennett Jennifer Y. , Alvarez Carlos E. , Lam Wan L.
Published: December 2009

DNA methylation regulates gene expression primarily through modification of chromatin structure. Global methylation studies have revealed biologically relevant patterns of DNA methylation in the human genome affecting sequences such as gene promoters, gene bodies, and repetitive elements. Disruption of normal methylation patterns and subsequent gene expression changes have been observed in several diseases especially in human cancers. Immunoprecipitation (IP)‐based methods to evaluate methylation status of DNA have been instrumental in such genome‐wide methylation studies. This review describes techniques commonly used to identify and quantify methylated DNA with emphasis on IP based platforms. In an effort to consolidate the wealth of information and highlight critical aspects of methylated DNA analysis, sample considerations, experimental and bioinformatic approaches for analyzing genome‐wide methylation profiles, and the benefit of integrating DNA methylation data with complementary dimensions of genomic data are discussed. J. Cell. Physiol. 222: 522–531, 2010. © 2009 Wiley‐Liss, Inc.
Inhibition of the p53–MDM2 interaction by adenovirus delivery of ribosomal protein L23 stabilizes p53 and induces cell cycle arrest and apoptosis in gastric cancer
Authors: Zhang Yafei , Shi Yongquan , Li Xiaohua , Du Wenqi , Luo Guanhong , Gou Yawen , Wang Xin , Guo Xuegang , Liu Jie , Ding Jie , Wu Kaichun , Fan Daiming
Published: December 2009

Background

Inhibiting MDM2 activity in tumors that express wild‐type (wt) p53 but have high levels of MDM2 protein has been considered an attractive anticancer strategy for many years. Previous studies revealed that human ribosomal protein L23 (RPL23) inhibited MDM2‐mediated p53 degradation and thus induced p53 levels as well as its activity, suggesting that it might be a candidate for use as a gene therapy for cancer. In the present study, we evaluated whether targeting this pathway could be of therapeutic value against human gastric carcinoma.

Methods

Gastric cancer cell lines carrying wt or mutant p53 gene were infected with adenovirus expressing RPL23 (Ad‐RPL23). Cell growth assay, flow cytometry assay and morphology were used to observe the effects of Ad‐RPL23 infection on tumor cells, and further, the effect of Ad‐RPL23 treatment on tumor growth in vivo was investigated.

Results

In vitro, adenovirus‐mediated RPL23 gene transfer stabilized wt p53 by inhibiting its degradation, and thus resulted in G1‐S cell cycle arrest and/or apoptosis of human gastric cancer MKN45 and AGS cells carrying wt p53 gene. Adenovirus‐mediated RPL23 gene transfer also inhibited the growth of MKN45 tumors in subcutaneous mouse models.

Conclusions

The data obtained in the present study suggest that, through the inhibition of the p53–MDM2 interaction, adenovirus delivery of RPL23 can inhibit the proliferation of gastric cancer cells harboring wt p53 in vitro and in vivo. Exogenous RPL23‐induced wt p53 stabilization and activation may be a novel therapeutic approach for patients with gastric cancer. Copyright © 2009 John Wiley & Sons, Ltd.
An evaluation of the potential to develop inbound Japanese tourism to Northeast Scotland using the Thomas Blake Glover connection
Authors: Nash Robert , Martin Andrew , Dalkarl Lis B. , Leith Craig , Stansbie Paul
Published: December 2009

This research explores the strength of the potential niche market associated with the Japanese's connection to Thomas Blake Glover. The study involved research to ascertain whether there is sufficient demand in Japan to sustain a heritage attraction or trail built up around Blake Glover in Northeast Scotland, as a means to counteract the decline of primary sector industries in the area. More specifically, the research set out to identify strategies to optimise the Blake Glover connection as a resource for Northeast Scotland. The research also highlights issues of significance to the wider Scottish tourism product in terms of attempting to attract the Japanese market to Scotland. Copyright © 2009 John Wiley & Sons, Ltd.
Synthesis and kinetic study of hydrolysis of di‐2‐chloroaniline phosphate ester in acidic medium
Authors: Choure Nitin , Bhoite S. A.
Published: December 2009

The kinetics and mechanism of the acid‐catalyzed hydrolysis of di‐2‐chloroaniline phosphate ester were studied in 0.5–7.0 mol dm−3hydrochloric acid at 80°C in 20/80 (v/v) dioxane–water medium. The log rate profile shows rate maximum at 4.0 mol dm−3hydrochloric acid. The results show that di‐2‐chloroaniline phosphate is reactive mainly via conjugate acid species. Ionic strength data show a positive salt effect. The effect of different parameters such as temperature, solvent, and substrate concentration on the rate of hydrolysis was studied. Molecularity and order of the reaction have been supported by Arrhenius parameters, the Zucker–Hammett hypothesis. The rate values shown by experimental and theoretical computational hold good agreements in the entire acid range. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 126–131, 2010
Kinetic study of the interaction of adenosine 5′‐monophosphate with diaqua (2‐hydrazinopyridine) palladium(II) in aqueous medium
Authors: Khattab Mohamed M. , Soliman Ahmed A. , Linert Wolfgang
Published: December 2009

The interaction of the palladium(II) complex [Pd(hzpy)(H2O)2]2+, where hzpy is 2‐hydrazinopyridine, with purine nucleoside adenosine 5′‐monophosphate (5′‐AMP) was studied kinetically under pseudo‐first‐order conditions, using stopped‐flow techniques. The reaction was found to take place in two consecutive reaction steps, which are both dependent on the actual 5′‐AMP concentration. The activation parameters for the two reaction steps, i.e. ΔH = 32 ±2 kJ mol−1, ΔS = −168 ±7 J K−1 mol−1, and ΔH = 28 ± 1 kJ mol−1, ΔS = −126 ± 5 J K−1 mol−1, respectively, were evaluated and suggested an associative mode of activation for both substitution processes. The stability constants and the associated speciation diagram of the complexes were also determined potentiometrically. The isolated solid complex was characterized by C, H, and N elemental analyses, IR, magnetic, and molar conductance measurements. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 132–142, 2010
Rate constant of the reaction of chlorine atoms with methanol over the temperature range 291–475 K
Authors: Kaiser E. W. , Wallington T. J.
Published: December 2009

The rate constant of the reaction Cl + CH3OH (k1) has been measured in 500–950 Torr of N2 over the temperature range 291–475 K. The rate constant determination was carried out using the relative rate technique with C2H6 as the reference compound. Experiments were performed by irradiating mixtures of CH3OH, C2H6, Cl2, and N2 with UV light from a fluorescent lamp whose intensity peaked near 360 nm. The resultant temperature‐dependent rate expression is k1 = 8.6 (±1.3) × 10−11 exp[−167 (±60)/T] cm3 molecule−1 s−1. Error limits represent data scatter (2σ) in the current experiments and do not include error in the reference rate constant. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 113–116, 2010
Carbon Nanotubes Fed on “Carbs”: Coating of Single‐Walled Carbon Nanotubes by Dextran Sulfate
Authors: Kotagiri Nalinikanth , Kim Jin‐Woo
Published: December 2009

A facile and easily reproducible technique for assembling biohybrid nanoparticles is a core feature that is highly desired for biomedical applications, considering the nature and limited lifespan of the biopolymers used. Here we show a simple and effective method to enfold single‐walled carbon nanotubes (SWNTs) using an anionic polysaccharide, dextran sulfate. After their interactions, SWNTs were rendered dispersible in aqueous solution and were shortened and unbundled to their basic dimension. Atomic force microscopy analysis was extensively employed to elucidate the mechanism of their interfacing. This biohybrid nanoparticle holds promise for biological and biomedical applications due to the synergistic unique properties of SWNTs and dextran sulfate.

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Silica Reinforced Organic–Inorganic Hybrid Polyurethane Nanocomposites From Sustainable Resource
Authors: Akram Deewan , Ahmad Shahzada , Sharmin Eram , Ahmad Sharif
Published: December 2009

Polyol/nanosilica organic–inorganic hybrids (Si/Lpol) were prepared through facile sol–gel chemistry. Tetraethoxyorthosilane (TEOS) and linseed polyol (Lpol) obtained by hydroxylation of linseed oil were used as inorganic and organic precursors, respectively. Si/Lpol was further treated with toluene‐2,4‐diisocyanate (TDI) to obtain silica embedded polyurethane (Si/LPU). The structure of the organic–inorganic hybrid was confirmed by FTIR, 1H NMR, and 13C NMR spectral analysis. The polyol/nanosilica network shows strong interaction with the remnant polyol backbone through hydrogen bonding, which also has bearing on Tg of polymers. Morphological studies of Si/LPU show the formation of uniform, spherical silica nanoparticles of 2–30 nm size embedded in the polymer matrix. Si/LPU was further reinforced with 2 and 5 wt.‐% fumed silica (FS‐Si/LPUs); their morphology revealed a carpet layer formation on top of Si/LPU. Thermogravimetric analysis showed improved thermal stability of Si/LPU and FS‐Si/LPUs. The polymers exhibit mild to moderate antibacterial behavior against E. coli and S. aureus, respectively, and will pave way in plethora of biological and chemical applications as coating materials.

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Nanofibrillar Single Polymer Composites of Poly(ethylene terephthalate)
Authors: Duhovic Miro , Bhattacharyya Debes , Fakirov Stoyko
Published: December 2009

Using the experience gained from the development of polymer–polymer nanofibrillar composites (NFCs), an attempt was undertaken to manufacture PET single polymer nanofibrillar composites. For this purpose polypropylene (PP) was removed by selective extraction from a knitted textile manufactured with PP/PET (80:20 by wt) blend. The remaining PET nanofibrillar textile was then sandwiched between lower‐melting PET films and compression molded at 120 °C. The obtained PET single polymer NFCs comprised PET nanofibrils as reinforcement and showed an improvement in the tensile strength and modulus of 37–100 and 40–140%, respectively (depending on the annealing temperature after compression molding and the test direction) compared to those of the starting isotropic matrix film.

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