bluuebunny/crossref_metadata_2025 huggingface dataset:
c[D‐pro‐Pro‐D‐pro‐N‐methyl‐Ala] adopts a rigid conformation that serves as a scaffold to mimic reverse‐turns
Authors: Arbor Sage , Kao Jeff , Wu Yun , Marshall Garland R.
Published: October 2007

Naturally occurring cyclic tetrapeptides (CTPs) such as tentoxin (Halloin et al., Plant Physiol 1970, 45, 310–314; Saad, Phytopathology 1970, 60, 415–418), ampicidin (Darkin‐Rattray, Proc Natl Acad Sci USA 1996, 93, 13143–13147), HC‐toxin (Walton, Proc Natl Acad Sci USA 1987, 84, 8444–8447), and trapoxin (Yoshida and Sugita, Jpn J Cancer Res 1992, 83, 324–328; Itazaki et al., J Antibiot (Tokyo) 1990, 43, 1524–1532) have a wide range of biological activity and potential use ranging from herbicides (Walton, Proc Natl Acad Sci USA 1987, 84, 8444–8447; Judson, J Agric Food Chem 1987, 35, 451–456) to therapeutics (Loiseau, Biopolymers 2003, 69, 363–385) for malaria (Darkin‐Rattray, Proc Natl Acad Sci USA 1996, 93, 13143–13147) and cancer (Yoshida and Sugita, Jpn J Cancer Res 1992, 83, 324–328). To elucidate scaffolds that have few low‐energy conformations and could serve as semirigid reverse‐turn mimetics, the flexibility of CTPs was determined computationally. Four analogs of cyclic tetraproline c[Pro‐pro‐Pro‐pro] with alternating L‐ and D‐prolines, namely c[pro‐Pro‐pro‐NMe‐Ala], c[pip‐Pro‐pip‐Pro], c[pro‐Pip‐pro‐Pro], and c[Ala‐Pro‐pip‐Pro] were synthesized and characterized by NOESY NMR. Both molecular mechanics and Density Functional Theory quantum calculations found these head‐to‐tail CTPs to be constrained to one or two relatively stable conformations. NMR structures, while not always yielding the same lowest energy conformation as expected by in silico predictions, confirmed only one or two highly populated solution conformations for all four peptides examined. c[pro‐Pro‐pro‐NMe‐Ala] was shown to have a single all trans‐amide bond conformation from both in silico predictions and NMR characterization, and to be a reverse‐turn mimetic by overlapping four Cα‐Cβ bonds with those for ∼6.5% (Tran, J Comput Aided Mol Des 2005, 19, 551–566) of reverse‐turns in the Protein Data Bank PDB with a RMSD of 0.57 Å. © 2007 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 90: 384–393, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Collagen scaffolds for tissue engineering
Authors: Glowacki Julie , Mizuno Shuichi
Published: October 2007

There are two major approaches to tissue engineering for regeneration of tissues and organs. One involves cell‐free materials and/or factors and one involves delivering cells to contribute to the regeneraion process. Of the many scaffold materials being investigated, collagen type I, with selective removal of its telopeptides, has been shown to have many advantageous features for both of these approaches. Highly porous collagen lattice sponges have been used to support in vitro growth of many types of tissues. Use of bioreactors to control in vitro perfusion of medium and to apply hydrostatic fluid pressure has been shown to enhance histogenesis in collagen scaffolds. Collagen sponges have also been developed to contain differentiating‐inducing materials like demineralized bone to stimulate differentiation of cartilage tissue both in vitro and in vivo. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 338–344, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Kinetics of thermal aggregation of glycogen phosphorylase b from rabbit skeletal muscle: Mechanism of protective action of α‐crystallin
Authors: Meremyanin Alexey V. , Eronina Tatyana B. , Chebotareva Natalia A. , Kurganov Boris I.
Published: October 2007

The kinetics of thermal aggregation of glycogen phosphorylase b (Phb) from rabbit skeletal muscle have been studied by dynamic light scattering (0.08M Hepes, pH 6.8, containing 0.1M NaCl; 48°C). The hydrodynamic radius of the start aggregates determined from the initial linear parts of the dependences of the hydrodynamic radius (Rh) on time was found to be 16.7 ± 1.0 nm. At rather high values of time, the Rh value for the protein aggregates becomes proportional to t1/1.8 = t0.56 suggesting that the aggregation process proceeds in the regime of diffusion‐limited cluster–cluster aggregation. In the presence of α‐crystallin, a protein possessing the chaperone‐like activity, the process of protein aggregation switches to the regime of reaction‐limited cluster–cluster aggregation as indicated by the exponential dependence of the Rh value on time. It was shown that the addition of α‐crystallin raises the rate of thermal inactivation of Phb. These data in combination with the results of the study of interaction of Phb with α‐crystallin by analytical ultracentrifugation suggest that α‐crystallin interacts with the intermediates of unfolding of the Phb molecule. © 2007 Wiley Periodicals, Inc. Biopolymers 89: 124–134, 2008.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Technique of semiautomatic surface reconstruction of the visible Korean human data using commercial software
Authors: Park Jin Seo , Shin Dong Sun , Chung Min Suk , Hwang Sung Bae , Chung Jinoh
Published: October 2007

This article describes the technique of semiautomatic surface reconstruction of anatomic structures using widely available commercial software. This technique would enable researchers to promptly and objectively perform surface reconstruction, creating three‐dimensional anatomic images without any assistance from computer engineers. To develop the technique, we used data from the Visible Korean Human project, which produced digitalized photographic serial images of an entire cadaver. We selected 114 anatomic structures (skin [1], bones [32], knee joint structures [7], muscles [60], arteries [7], and nerves [7]) from the 976 anatomic images which were generated from the left lower limb of the cadaver. Using Adobe Photoshop, the selected anatomic structures in each serial image were outlined, creating a segmented image. The Photoshop files were then converted into Adobe Illustrator files to prepare isolated segmented images, so that the contours of the structure could be viewed independent of the surrounding anatomy. Using Alias Maya, these isolated segmented images were then stacked to construct a contour image. Gaps between the contour lines were filled with surfaces, and three‐dimensional surface reconstruction could be visualized with Rhinoceros. Surface imperfections were then corrected to complete the three‐dimensional images in Alias Maya. We believe that the three‐dimensional anatomic images created by these methods will have widespread application in both medical education and research. Clin. Anat. 20:871–879, 2007. © 2007 Wiley‐Liss, Inc.
Jacobus Sylvius (1478–1555): Physician, teacher, and anatomist
Authors: Tubbs R. Shane , Linganna Sanjay , Loukas Marios
Published: October 2007

Jacques Dubois (1478–1555), better known by his Latin cognomen Jacobus Sylvius was one of the great anatomists and teachers of the Renaissance period. His legacy today, however, is marred by his feud with pupil Andreas Vesalius. The story of Sylvius's life provides the modern clinical anatomist with valuable lessons regarding the nature of orthodoxy, conflict, and the evolving nature of “truth.” Clin. Anat. 20:868–870, 2007. © 2007 Wiley‐Liss, Inc.
3D morphometry of the transverse and alar ligaments in the occipito–atlanto–axial complex: An in vitro analysis
Authors: Cattrysse E. , Barbero M. , Kool P. , Gagey O. , Clarys J.P. , Van Roy P.
Published: October 2007

This study verifies the three‐dimensional anatomical features of the transverse and alar ligaments with reference to the axis using a direct in vitro approach. In 20 fresh spine specimens, metal markers were inserted on the cranium, atlas, and axis. After registration of the intact specimen, the bony segments were separated, and markers and anatomical landmarks were digitized. The length and the orientation of the ligaments with reference to the axis were derived from the relative position data. The transverse ligaments of the atlas have a mean estimated length of 21 mm and an absolute angle (i.e., independent of any reference frame) of 119° ± 17°. The alar ligaments have a mean length of 9 ± 2.5 mm, and the mean absolute angle between the ligaments is 117° ± 31°. The plane of the alar ligaments shows a mean backward inclination of −10° ± 52°. This plane has a mean inclination of 6° ± 4° with reference to the sagittal plane indicating left–right symmetries. The transverse ligament arches around the dens and demonstrating its function as a stabilizer for the dens as well as guidance for axial rotation movements. A posterior inclination of the alar ligaments may induce a coupled extension in combination with a lateral bending during axial rotation. These detailed aspects of motion steering may be important to consider when attempting to reduce or restore movement. Clin. Anat. 20:892–898, 2007. © 2007 Wiley‐Liss, Inc.
Synthesis and Study of Calix[6]cryptamides: A New Class of Heteroditopic Receptors that Display Versatile Host–Guest Properties Toward Neutral Species and Organic Associated Ion‐Pair Salts
Authors: Le Gac Stéphane , Jabin Ivan
Published: October 2007

The synthesis of a new family of molecular receptors, namely the calix[6]cryptamides, was achieved through an original [1+1] macrocyclization step that consists of a peptide‐coupling reaction between tripodal triscarboxylic acids and a calix[6]trisamine subunit. SeveralC3‐ orC3v‐symmetrical calix[6]arene‐based compounds capped by a trisamido cryptand unit on the narrow rim have been obtained, with the more flexible partners leading to the best yields. These calix[6]cryptamides exhibit two favorably positioned binding sites for the complexation of organic‐associated ion pairs in close proximity: a well‐defined calix[6]arene cavity suitable for the inclusion of ammonium ions and a cryptamide unit for the coordination of anions. We demonstrate one example, chiral calix[6]cryptamide12, that constitutes a heteroditopic receptor capable of cooperatively binding both a primary ammonium ion and its chloride counterion, thanks to a combination of polarization and induced‐fit effects. In addition, the hydrophobic calixarene cavity of12can strongly bind neutral guests through hydrogen bonding and is capable of discriminating between different enantiomers. All these versatile host–guest properties differ greatly from those observed in the parent calix[6]azacryptands.
Processing Energy and Signals by Molecular and Supramolecular Systems
Authors: Balzani Vincenzo , Credi Alberto , Venturi Margherita
Published: October 2007

Any kind of device or machine requires a substrate, energy, and information signals. If we wish to operate at the nanometer scale, we must use molecules as substrates. Energy‐ and signal‐processing at a molecular level relies on cause/effect relationships between the input supplied and the kind of process obtained. We have classified energy‐ and signal‐processing at the molecular level according to the nature of the input (electronic, photonic, or chemical) and the nature of the obtained effect (electronic, photonic, or chemical process that follows). By coupling the three kinds of inputs with the three types of resulting processes, nine types of molecular‐based processes (electronic, photonic, chemionic, electrophotonic, electrochemionic, photoelectronic, photochemionic, chemiophotonic, and chemioelectronic) can be identified. In this concept article, looking at molecular transformations in an unconventional way, we have tried to give a flavor of some of the new features that project the old science of chemistry towards novel achievements.
The First Homochiral Diamond‐Like Coordination Polymer Containing Cubane Cluster (Cu4I4) as Connecting Node and Cinchonine as Donor‐Acceptor (or Push‐Pull Electronic Effect) Building Block
Authors: WANG Guo‐Xi , XIONG Ren‐Gen
Published: October 2007

The reaction of CuI with cinchonine (an organic donor‐acceptor chromophore) afforded a homochiral 3D diamondoid network [Cu4I4(cinchonine)2]n (1) containing a cubane cluster (Cu4I4) as a connecting node. This is the first homochiral coordination polymer with diamondoid nets containing a cluster as a connecting note. Its thermal stability and solid state optical properties such as fluorescence, circular dichroism and second‐harmonic generation response were also reported.
A Facile Synthesis of Indole‐based Conjugated Derivatives
Authors: LI Qian‐Qian , ZHU Zhi‐Chao , LI Zhen , QIN Jin‐Gui
Published: October 2007

A novel synthetic method was developed for the preparation of indole‐based conjugated derivatives with satisfied yields. By applying this strategy, a series of new compounds were prepared conveniently. All the obtained new indole derivatives were characterized by spectroscopic analyses, giving satisfactory data corresponding to their expected molecular structures.
Hydrogen Bonded Semi‐Rigidified Bispyridyl‐Incorporating Aryl Amide Oligomers: Efficient "C"‐Styled Receptors for Aliphatic Ammoniums, a Remarkable Protonation Effect and Chiral Induction
Authors: LI Chang‐Zhi , LI Zhan‐Ting , GAO Xiang , WANG Quan‐Rui
Published: October 2007

The complexing behaviour of two linear compounds 1 and 2 toward the trifluoroacetic acid (TFA) salts of n‐dodecylamine, di‐n‐octylamine, n‐dodecyl D‐ and L‐phenylalaninates (3, 4, and D‐ and L‐5) in chloroform has been described. Compounds 1 and 2 consist of two folded amide moieties with two pyridyls at the terminals which are connected directly or with an acetylene linker. The rigidified folded moieties are stabilized by intramolecular hydrogen bonding, while the whole molecules can adopt an "S"‐ or a "C"‐styled conformation depending on the relative orientation of the two rigidified moieties. 1H NMR, UV‐Vis, fluorescent and circular dichroism investigations revealed that 1 and 2 could bind primary and secondary ammonium cations with their "C"‐styled conformation. In the presence of 1 equiv. of TFA, the binding stability was increased significantly as a result of promoted formation of the "C"‐styled conformation due to the monoprotonation of the peripheral pyridyl units in 1 and 2. In contrast, the addition of 2 equiv. of TFA substantially weakened the binding stability because the "S"‐styled conformation was favored as a result of protonation of both of their pyridyl units. Moreover, remarkable induced circular dichroisms were also displayed for the complexes of 1 and 2 with chiral D‐ and L‐5.
Molecular Modeling of Interactions of the Benzolactam‐V8 Modulators with the Cys2 Domain of Protein Kinase Cδ
Authors: HUANG Li‐Li , MA Da‐Wei , XIA Zong‐Xiang
Published: October 2007

Molecular modeling of interactions of four 7‐ or 8‐substituted benzolactam‐V8 (BLV) molecules with the cys2 activator‐binding domain of protein kinase C (PKCδ) was carried out using molecular docking program Autodock. The docked models reveal that the hydroxymethyl group at the C(5) atom of the eight‐membered ring of each BLV is bound at the bottom of the binding groove of the cys2 domain of PKCδ. The BLV molecules make hydrogen bonds and hydrophobic interactions with PKCδ, which are similar to those in the crystal structure of the cys2 domain of PKCδ in complex with phorbol 13‐acetate. BLV‐1 does not contain a long side chain that is hydrophobic and necessary for membrane insertion, so that it would not be a potent modulator of PKCδ. The other three BLV molecules have long side chains substituted at C(7) or C(8) atoms, and it was predicted, based on the docking results, that they had the PKCδ‐binding affinity in the order of BLV‐2>BLV‐4>BLV‐3, and BLV‐2 would be a potent activator of PKCδ.
Is There a Minimum Electrophilicity Principle in Chemical Reactions?
Authors: NOORIZADEH Siamak
Published: October 2007

For 25 simple reactions, the changes of the hardness (Δη), polarizability (Δα) and electrophilicity index (Δω) and their cube‐roots (Δη1/3, Δα1/3, Δω1/3) were calculated. It is shown that although the Maximum Hardness and Minimum Polarizability Principles are not valid for all reactions, but in most cases Δω1/3<0, whereas we always find Δω<0. Our observation implies to this fact that for those chemical reactions in which the number of moles decreases or at least remains constant, the most stable species (reactants or products) have the lowest sum of electrophilicities. In other words "the natural direction of a chemical reaction is toward a state of minimum electrophilicity". This fact may be called Minimum Electrophilicity Principle (MEP).
Nitrogen‐rich 6‐(3,5‐Dimethylpyrazol‐1‐yl)‐3‐(2,4,6‐trinitro‐anilino)‐1,2,4,5‐tetrazin: Synthesis, Crystal Structure and Thermal Property
Authors: PAN Wan‐Long , HUANG Kun‐Lin , TANG Wang , XU Yan‐Qing , HU Chang‐Wen
Published: October 2007

6‐(3,5‐Dimethylpyrazol‐1‐yl)‐3‐(2,4,6‐trinitroanilino)‐1,2,4,5‐tetrazin (1) has been synthesized and characterized by 1H NMR, MS, elemental analysis, infrared spectra and thermal analyses. The crystal structure was determined by X‐ray diffraction method. 1 is crystallized in P21/c space group of monoclinic crystal system, and exhibits good physical properties, such as high densities (>1.55 g·cm−3) and good thermal stabilities (Td>220 °C). The intrermolecular hydrogen bonds construct the P‐ and M‐helices from organic molecules and may contribute to the high melting points.
Sorption Removal of Pb(II) from Solution by Uncalcined and Calcined MgAl‐Layered Double Hydroxides
Authors: ZHANG Shu‐Qin , HOU Wan‐Guo
Published: October 2007

Layered double hydroxide (LDH) with a Mg/Al molar ratio of 1:1 was synthesized by using a co‐precipitation method and its calcined product (CLDH) was obtained by calcination of the MgAl‐LDH at 500 °C. The sorption removal of Pb2+ from solution was investigated, finding that both LDH and CLDH show good sorption ability and they could be used as a new type of environmental sorbent for the removal of Pb2+ from water. The sorption kinetics and the sorption isotherms of Pb2+ on both LDH and CLDH can be described by the pseudo‐second order kinetics and Freundlich isotherm, respectively, under the studied conditions. The sorption amounts of Pb2+ on LDH and CLDH are independent of pH in a pH range of about 3–10. The presence of NaNO3 may inhibit the sorption ofPb2+ on LDH while hardly affect that on CLDH. The sorption mechanism of Pb2+ on LDH and CLDH may be attributed to the surface precipitation and the surface complex adsorption. The surface complex adsorption may be further distinguished to the chemical binding adsorption forming the inner‐sphere surface complexes and the electrostatic binding adsorption forming the outer‐sphere surface complexes. The sorption mechanism of Pb2+ on LDH may be attributed to the surface precipitation and the electrostatic binding adsorption, while that on CLDH may be attributed to the surface precipitation and the chemical binding adsorption.
Theoretical Study of the Low‐Lying Excited States of Butoxy Radicals and Non‐Radiative Decay Routes
Authors: LIN Ling , ZU Li‐Li , FANG Wei‐Hai , YU Jian‐Guo , LIU Ruo‐Zhuang
Published: October 2007

The potential energy surfaces for the butoxy radical dissociation into R·+O on the six low‐lying electronic states have been determined with the combined CASSCF and MR‐CI methods. The isomerization reactions between the different conformers of 1‐ and 2‐butoxy radicals at the X̃ and B̃ states have been also investigated with the MP2, B3LYP, and CASSCF methods. The non‐radiative decay mechanisms of butoxy radicals at the B̃ state have been characterized with the computed potential energy surfaces and intersections. Supported by recent LIF experimental results, it was predicted that the t‐butoxy radical would predissociate via the B̃/ C̃ intersection. As to 1‐ and 2‐butoxy radicals, the relative energies of the transition states for the isomerization reactions between conformers at the B̃ state are much lower than those of the B̃/C̃ intersections, resulting in the predominance of the isomerization in the decay of the B̃ state for 1‐ and 2‐butoxy radicals.
Molecular Dynamics Simulation of the Self‐assembled Monolayers of 1‐Adamantanethiolate and Its Derivatives on Au(111) Surfaces
Authors: ZHOU Jun‐Hong , ZHU Rui‐Xin , SHI Liang‐Wei , ZHANG Tao , CHEN Min‐Bo
Published: October 2007

The self‐assembled monolayers (SAMs) of 1‐adamantanethiolate and its derivatives on Au(111) surface were investigated. Density functional theory (DFT) calculation indicates that the most stable configuration for absorption is at the face centered cubic (fcc)‐bridge site. Canonical ensemble molecular dynamics (MD) simulations were carried out to study the structures and energies of the SAMs. The ordered structures of the SAMs were analyzed by means of radial distribution function and the relative stability of the SAMs was compared. It was concluded by the comparison of various contributions to the SAM formation energy that the formation of the SAMs was determined by the intermolecular nonbonding interaction and the chemical bonding interaction of sulfur and gold.
Theoretical Studies on Reaction Mechanism of CH3SO with NO
Authors: LI Xiao‐Yan , MENG Ling‐Peng , ZHENG Shi‐Jun
Published: October 2007

The potential energy surface (PES) of CH3SO radical with NO reaction has been studied at MP2/6‐311G(2df,p) and QCISD/6‐311G(2df,p) levels. Geometries of the reactants, transition states (TS) and products were optimized at B3LYP/6‐311G (d,p) level. The geometries of the transition states were found for the first time. The calculated results show that the reaction can proceed via singlet‐state or triplet‐state PES. Because of the high energy barrier of triplet surface, the singlet surface reactions are dominant. The topological analysis of electron density shows that there are two kinds of structural transition states (the bifurcation‐type ring structure transition state and the T‐shaped conflict structure transition state) in the titled reaction. The total electronic density of the reactants, TS and products and the spin electronic density on the triplet surface were also discussed in this paper.
Aggregate Formed by a Cationic Fluorescence Probe
Authors: TIAN Juan , SANG Da‐Yong , JI Guo‐Zhen
Published: October 2007

The aggregation behavior of a cationic fluorescence probe 10‐(4,7,10,13,16‐pentaoxa‐1‐azacyclooctadecyl‐ methyl)anthracen‐9‐ylmethyl dodecanoate (1) was observed and studied by a fluorescence methodology in acidic and neutral conditions. By using the Py scale, differences between simple aggregates and micelles have been discussed. The stability of simple aggregates was discussed in terms of hydrophobic interaction and electrostatic repulsion. The absence of excimer emission of the anthrancene moiety of probe 1 in neutral condition was attributed to the photoinduced electron transfer mechanism instead of photodimerization.
Electronic Properties of Two Series of Blue‐Emitting Conjugated Oligomers and Polymers Based on Cyanostilbene: A Quantum Chemistry Study
Authors: YANG Li , FENG Ji‐Kang , REN Ai‐Min
Published: October 2007

One of the drawbacks of the electroluminescence (EL) polymers is that they are usually much better at accepting and transporting holes than electrons due to their inherent richness of π‐electrons. One approach improving electron injection and transport in conjugated polymers is to incorporate moieties with high electron affinities. In this theoretical work, to gain an insight into the chemical structure‐property relationships was aimed by controllable modification of the main chain structures. Two cyanovinylene derivatives with 2,7‐fluorenylene and p‐phenylene moieties in the main chains, namely, poly{(2,5‐dimethoxy‐p‐phenylene‐1,4‐ylene)‐alt‐[1,2‐bis(p‐phenylene)‐1‐ cyanovinylene]} (PPhCN) and poly{[9,9‐dimethyl‐2,7‐fluorenylene]‐alt‐[1,2‐bis(p‐phenylene)‐1‐cyanovinylene]} (PFCN), were studied employing density functional theory (DFT) and time dependent density functional theory (TD‐DFT) with B3LYP functional. The electronic properties of the neutral molecules, extrapolated ionization potentials (IP) and electron affinities (EA), and energy gaps were investigated in comparison with pristine poly(2,7‐ fluorenylene). From comparison with poly(2,7‐fluorenylene) (PF), the 1,2‐bis(p‐phenylene)‐1‐cyanovi‐ nylene unit was found to be a good electron‐withdrawing moiety for electronic materials and the incorporation of 1,2‐bis(p‐ phenylene)‐1‐cyanovinylene resulted in a narrow band gap and a red shift of both the absorption and photoluminescence emission peaks. Most importantly, the LUMO energies of PFCN are around 1 eV lower than those of PF, which results in the decrement of EA about 0.9 eV, indicating that the 1,2‐bis(p‐phenylene)‐1‐cyanovinylene unit has significantly improved the electron‐accepting properties of the copolymer PFCN. Substitution of 2,5‐dimeth‐ oxy‐p‐phenylene for 9,9‐dimethyl‐2,7‐fluorenylene induced larger band gaps and thus a blue‐shift in absorption and emission peaks, which can be attributed to the better conjugated backbone in PFCN.
Preparation and Characterization of Mesoporous Ce0.5Zr0.5O2 Mixed Oxide
Authors: FENG Sheng‐Sheng , GU Ying‐Ying , LI Jin‐Lin , SONG Feng‐Xuan
Published: October 2007

Mesoporous (MSU) Ce0.5Zr0.5O2 mixed oxide with a high specific surface area has been synthesized under weak acidic condition in the presence of an anionic surfactant, sodium dodecylbenzenesulfonate. The effect of the pH value on the formation of mesostructure and the thermal stability of the material has been evaluated. The products were characterized by transmission electron microscopy, powder X‐ray diffraction and nitrogen adsorption‐desorption measurements. The results showed that the as‐prepared Ce0.5Zr0.5O2 mixed oxide possessed a specific surface area of 163.3 m2·g−1, which had a cubic fluorite‐type structure and possessed specific surface areas of 148.4 and 62.4 m2·g−1 after calcination at 500 and 800 °C for 2 h, respectively. The material showed excellent thermal stability.
A New 4.0‐Generation Dendrimer Phosphorescence Labeling Reagent and Its Application to Determination of Trace Alkaline Phosphatase by Affinity Adsorption Solid Substrate‐room Temperature Phosphorimetry
Authors: LI Zhi‐Ming , LIU Jia‐Ming , CHEN Xiao‐Hua , YANG Min‐Lan , CHEN Xin‐Hua , SHI Xiu‐Mei
Published: October 2007

A Triton X‐100‐4.0G‐D (4.0G‐D refers to a 4.0‐generation dendrimer) was brought forward as a new phosphorescence labeling reagent. Two types of specific affinity adsorption (AA) reactions (direct method and sandwich method) were carried out between the labeling product of Triton X‐100‐4.0G‐D‐Wheat germ agglutinin (WGA) and alkaline phosphatase (ALP), the product of AA reaction preserved the good characteristics of room temperature phosphorescence (RTP) of 4.0G‐D and ΔIP of the product was proportional to the content of ALP. According to the fact stated above, a new method for the determination of trace ALP by affinity adsorption solid substrate‐room temperature phosphorimetry (AA‐SS‐RTP) was established on the basis of WGA labeled with the Triton X‐100‐4.0G‐D. The detection limits were 0.20 ag·spot−1 (corresponding concentration: 5.0×10−16 g·mL−1, namely 5.0×10−18 mol·L−1) for a direct method and 0.14 ag·spot−1 (corresponding concentration: 3.5×10−16 g·mL−1, namely 3.5×10−18 mol·L−1) for a sandwich method, respectively. For their high sensitivity, good repeatability and high accuracy, the direct method and sandwich method have been successfully applied to determine the content of ALP in human serum, and the results were coincided with the clinical detection results of the enzyme‐linked immunosorbent assay method by the Zhangzhou Hospital of Traditional Chinese Medicine. Meanwhile, the mechanism for the determination of trace ALP by AA‐SS‐RTP was discussed.
Selective Pre‐concentration and Solid Phase Extraction of Mercury(II) from Natural Water by Silica Gel‐loaded (E)‐N‐(1‐Thien‐2′‐ylethylidene)‐1,2‐phenylenediamine Phase
Authors: MOGHIMI Ali
Published: October 2007

Silica gel‐loaded (E)‐N‐(1‐thien‐2′‐ylethylidene)‐1,2‐phenylenediamine (TEPDA) phase was synthesized based on physical adsorption approaches. The stability of a chemically modified TEPDA especially in concentrated hydrochloric acid that was then used as a recycling and preconcentration reagent allowed the further uses of silica gel‐loaded immobilized TEPDA phase. The application of this silica gel‐loaded phase to sorption of a series of metal ions was performed by using different controlling factors such as the pH of the metal ion solution and the equilibration shaking time by the static technique. This difference was interpreted on the basis of selectivity incorporated in these sulfur containing silica gel‐loaded TEPDA phases. Hg(II) was found to exhibit the highest affinity towards extraction by these silica gel‐loaded TEPDA phases. The pronounced selectivity was also confirmed by the determined distribution coefficients (Kd) of all the metal ions, showing the highest value reported for mercury(II) extraction by the silica gel immobilized TEPDA phase. The potential applications of the silica gel immobilized TEPDA phase to selective extraction of mercury(II) from aqueous solution were successfully accomplished and preconcentration of low concentration of Hg(II) (30 pg·mL−1) from natural tap water with a preconcentration factor of 200 for Hg(II) off‐line analysis was conducted by cold vapor atomic absorption analysis.
Synthesis of Diphenyl α‐(Dipropoxyphosphoramido)alkylphosphonates
Authors: CUI Zhan‐Wei , ZHANG Jian‐Feng , MIAO Zhi‐Wei , CHEN Ru‐Yu
Published: October 2007

A convenient method has been developed for the synthesis of diphenyl α‐(dipropoxyphosphoramido)alkyl‐ phosphonates under mild conditions, namely the reaction of dipropyl phosphoramidate (1) with a para‐ (un)substituted benzaldehyde or cyclicketone (2) and triphenyl phosphite (3) by a one‐pot procedure with the aid of acetyl chloride.
ZrOCl2 Catalysed Chemoselective Conversion of Aldehydes to geminal‐Diacetates and Their Cleavage: A Mild and Efficient Method
Authors: NAGARAJ Adki , SANJEEVA REDDY Cherkupally
Published: October 2007

ZrOCl2 was found to be an effective Lewis acid catalyst for the solventless chemoselective conversion of aldehydes into geminal‐diacetates in high yields at room temperature. Regeneration of the aldehydes from the acetals was also achieved using the same catalyst in water. The beneficial effect of microwave irradiation on the reaction was also described. Other advantages are the very low loading of catalyst, high yields achieved even on a gram scale, and considerably shortened reaction time compared to the conventional method.
Solvent‐free Knoevenagel Condensations over TiO2
Authors: HOSSEINI‐SARVARI Mona , SHARGHI Hashem , ETEMAD Samane
Published: October 2007

A study involving the scope of substrates in the Knoevenagel reaction under SFC has been conducted. Reactivity trends favored formation of the condensation product using both electron deficient and rich aryl aldehydes. A recycling study confirmed that the reaction medium could be used multiple times affording, with each run, the desired condensation product in excess of 95% conversion.
A Simple One‐pot Synthesis of 3,5‐Dicyano‐1,2‐dihydropyrid‐2‐ones in Aqueous Media
Authors: ZHUANG Qi‐Ya , XU Jia‐Ning , TU Shu‐Jiang , JIA Run‐Hong , ZHANG Jun‐Yong , LI Chun‐Mei , ZHOU Dian‐Xiang
Published: October 2007

A simple and clean synthesis of 3,5‐dicyano‐1,2‐dihydropyrid‐2‐ones by a one‐pot three‐component reaction of malononitrile, aromatic aldehydes and 2‐cyanoacetamide or 2‐cyanothioacetamide has been achieved in an aqueous solution with potassium carbonate as a base under microwave irradiation without a phase transfer reagent. This protocol has the advantages of short reaction time (5–8 min) and convenient work‐up.
Synthesis and Characterization of Poly(butylene adipate‐co‐ terephthalate) Catalyzed by Rare Earth Stearates
Authors: ZHU Kui , ZHU Wei‐Pu , GU Yan‐Bo , SHEN Zhi‐Quan , CHEN Wei , ZHU Gui‐Xiang
Published: October 2007

Rare earth (Nd, Y, La, Dy) stearates have been synthesized and used as single component catalysts for the polycondensation of dimethyl terephthalate, adipic acid and 1,4‐butanediol for the first time preparing biodegradable poly(butylene adipate‐co‐terephthalate) (PBAT) with high molecular weight. The microstructures of PBAT were characterized by 1H NMR spectra. The PBAT exhibits good mechanical properties such as high tensile strength (ca. 20 MPa) and long break elongation (>700%).
Molten‐salt Synthesis and Properties of ZnS with Hexagonal Prism Morphology
Authors: LIU Jin‐Song , JI Guang‐Bin , LI Zi‐Quan , CAO Jie‐Ming , ZHENG Ming‐Bo , KE Xing‐Fei
Published: October 2007

ZnS with hexagonal prism morphology has been synthesized successfully by molten‐salt method with ZnS nanoparticles as precursors, and the ZnS nanoparticles were prepared by one‐step solid‐state reaction of Zn(CH3COO)2·2H2O with Na2S·9H2O at ambient temperature. Crystal structure and morphology of the product were characterized by X‐ray diffraction, scanning electron microscopy, transmission electron microscopy and HRTEM. Ultraviolet‐visible optical absorption spectrum of the ZnS hexagonal prism shows a distinct red shift from that of bulk ZnS crystals and photoluminescence spectrum exhibits strong emissions at 380 and 500 nm, respectively. Further experiments were designed and the formation mechanism of the ZnS hexagonal prism has been also discussed in brief.
Alkoxymethylenephosphonate Analogues of (Lyso)phosphatidic Acid Stimulate Signaling Networks Coupled to the LPA2Receptor
Authors: Gajewiak Joanna , Tsukahara Ryoko , Tsukahara Tamotsu , Yu Shuanxing , Lu Yiling , Murph Mandi , Mills Gordon B. , Tigyi Gabor , Prestwich Glenn D.
Published: October 2007

An efficient stereocontrolled synthesis afforded alkoxymethylenephosphonate (MP) analogues of lysophosphatidic acid (LPA) and phosphatidic acid (PA). The pharmacological properties of MP‐LPA and MP‐PA analogues were characterized for LPA receptor subtype‐specific agonist and antagonist activity using Ca2+‐mobilization assays in RH7777 cells expressing the individual LPA1–LPA3receptors and CHO cells expressing LPA4. In addition, activation of a PPARγ reporter gene construct expressed in CV‐1 cells was assessed. These metabolically stabilized LPA analogues exhibited an unexpected pattern of partial agonist/antagonist activity for the LPA G‐protein‐coupled receptor family and the intracellular LPA receptor PPARγ. Analogues were compared with 18:1 LPA for activation of downstream signaling in HT‐29 colon cancer cells, which exclusively express LPA2, and both SKOV3 and OVCAR3 ovarian cancer cells, which express LPA1, LPA2, and LPA3. Unexpectedly, reverse phase protein arrays showed that four MP‐LPA and MP‐PA analogues selectively activated downstream signaling in HT‐29 cells with greater potency than LPA. In particular, the oleoyl MP‐LPA analogue strongly promoted phosphorylation and activation of AKT, MEK, and pS6 in HT‐29 cells in a concentration‐dependent manner. In contrast, the four MP‐LPA and MP‐PA analogues were equipotent with LPA for pathway activation in the SKOV3 and OVCAR3 cells. Taken together, these results suggest that the MP analogues may selectively activate signaling via the LPA2receptor subtype, while simultaneously suppressing signaling through the LPA1and LPA3subtypes.
Interferon‐α and 5‐fluorouracil combination therapy after palliative hepatic resection in patients with advanced hepatocellular carcinoma, portal venous tumor thrombus in the major trunk, and multiple nodules
Authors: Nagano Hiroaki , Miyamoto Atsushi , Wada Hiroshi , Ota Hideo , Marubashi Shigeru , Takeda Yutaka , Dono Keizo , Umeshita Koji , Sakon Masato , Monden Morito
Published: October 2007

BACKGROUND.

The authors reported previously the beneficial effects of interferon (IFN)‐α/5‐fluorouracil (5‐FU) combination therapy for patients with advanced hepatocellular carcinoma (HCC) who have tumor thrombi in the major portal branches. In this report, the authors describe the results from IFN/5‐FU chemotherapy for patients who underwent palliative hepatic resection for advanced HCC with tumor thrombus in the main trunk of the portal vein and multiple nodules in the whole liver. In addition, they evaluated the correlation between the response to such therapy and expression of IFN‐α type 2 receptor (IFNAR2).

METHODS.

From October 1999 to December 2004, 30 patients with advanced HCC, tumor thrombi in the main trunk of the portal vein, and multiple nodules in the whole liver (Vp4 and grade 3 intrahepatic metastases) were recruited for this study. They underwent palliative hepatic resection followed by at least 2 courses of IFN/5‐FU. IFNAR2 expression levels were determined by immunohistochemistry.

RESULTS.

No major treatment‐related complications were noted. An objective response was noted in 10 patients (33.3%) and included a complete response in 6 patients (20%), a partial response in 4 patients (13.3%), no response in 1 patient (3.3%), and progressive disease in 19 patients (63.4%). IFNAR2 expression was detected in 20 of 30 patients (66.7%). There was a significant difference in overall survival between patients with positive and negative IFNAR2 expression cases (P < .0025), and a significant correlation was observed between IFNAR2 expression and response to IFN/5‐FU combination therapy (P = .0199).

CONCLUSIONS.

Adjunct IFN/5‐FU therapy is a promising modality for patients with advanced HCC, tumor thrombi in the major trunk, and multiple nodules after palliative hepatic resection. The results from this study indicated that the response to such therapy seemed to be correlated with IFNAR2 expression. Cancer 2007. © 2007 American Cancer Society.
Cytoreductive nephron‐sparing surgery does not appear to undermine disease‐specific survival in patients with metastatic renal cell carcinoma
Authors: Hutterer Georg C. , Patard Jean‐Jacques , Colombel Marc , Belldegrun Arie S. , Pfister Christian , Guille Francois , Artibani Walter , Montorsi Francesco , Pantuck Allan J. , Karakiewicz Pierre I.
Published: October 2007

BACKGROUND.

The role of nephron‐sparing surgery (NSS) showed promise in patients with metastatic renal cell carcinoma (MRCC). The disease‐specific survival of patients with MRCC was compared according to the type of surgery, NSS (N = 45) versus radical nephrectomy (RN) (N = 732), in unmatched and matched analyses.

METHODS.

Kaplan‐Meier, life tables, log‐rank test, and univariate as well as multivariate Cox regression analyses addressed disease‐specific survival of NSS versus RN patients. Subsequently, up to 4 RN cases were matched with each NSS case for TNM stage, Fuhrman grade, and histology. Then, disease‐specific survival differences were tested with the log‐rank statistic. Finally, the sample size necessary to achieve 80% power in survival analyses between the 2 groups (NSS vs RN) was calculated.

RESULTS.

Of 45 NSS cases, 38 were matched with 99 of 732 RN cases. First, in multivariate unmatched analyses RN predisposes to 1.7‐fold higher RCC‐specific mortality rate; second, in matched analyses RN predisposes to 1.5‐fold higher RCC‐specific mortality rate; and third, both analyses failed to demonstrate statistically significant differences. Based on these findings it could be postulated that until further data become available, NSS does not appear to undermine RCC‐specific survival in carefully selected patients with MRCC. The power analyses demonstrated that at least 146, 48, and 76 observations per arm are necessary at 1, 2, and 3 years, respectively, to confirm survival equivalence.

CONCLUSIONS.

Although the data were limited in size and completeness, they may indicate that RCC‐specific survival may not be undermined if NSS is performed in properly selected cases. Cancer 2007. © 2007 American Cancer Society.
Computed tomography screening for lung cancer: Review of screening principles and update on current status
Authors: Black William C.
Published: October 2007

Screening for lung cancer with low‐dose computed tomography (CT) is controversial. In favor of screening, lung cancer is the leading cause of cancer death in the United States, and those at greatest risk are identified readily on the basis of age and smoking history. In addition, it is well established that CT is far more sensitive than chest radiography in detecting lung cancer when it is small and asymptomatic. Furthermore, very high rates of survival were reported recently for screen‐detected lung cancers in a large, multinational, single‐arm observational study. However, a reduction in lung cancer mortality has not been demonstrated to date, and a recent longitudinal study with a simulated control group suggested little or no mortality reduction. In addition, there are important harms from CT screening, including false‐positive test results and overdiagnosis. Furthermore, healthcare resources are finite. Therefore, even if the benefits do outweigh the harms, the cost‐effectiveness of CT screening for lung cancer still will need to be considered in the context of competing healthcare alternatives. The objectives of this article were 3‐fold: 1) to review the basic principles of screening and study designs related to cancer screening, 2) to summarize the results of the observational and analytical studies of CT screening that have been reported to date, and 3) to describe the design of the 2 ongoing, randomized controlled trials of CT screening and what may be learned from these studies in the near future. Cancer 2007. © 2007 American Cancer Society.
Placement of radiopaque clips for tumor localization in patients undergoing neoadjuvant chemotherapy and breast conservation therapy
Authors: Oh Julia L. , Nguyen Giang , Whitman Gary J. , Hunt Kelly K. , Yu Tse‐Kuan , Woodward Wendy A. , Tereffe Welela , Strom Eric A. , Perkins George H. , Buchholz Thomas A.
Published: October 2007

BACKGROUND.

The objective of this study was to determine whether patients with breast cancer who received breast‐conservation therapy after neoadjuvant chemotherapy had improved outcomes if radiopaque clips were placed to mark the primary tumor.

METHODS.

The authors retrospectively reviewed the records of 410 patients with nonmetastatic breast cancer who received doxorubicin‐based neoadjuvant chemotherapy and breast‐conservation therapy from January 1990 to September 2005. Thirty‐seven of those patients were omitted because of the inability to verify radiopaque clip placement in the primary tumor.

RESULTS.

Of the 373 patients who were analyzed, 145 patients had radiopaque clips placed to mark the primary tumor before or during neoadjuvant chemotherapy, and 228 patients did not. The distribution of clinical T classification, nuclear grade, estrogen receptor status, final margin status, and extent of residual primary disease was similar between the 2 groups. After a median follow‐up of 49 months (range, 20‐177 months), 21 patients developed a local recurrence in the treated breast. The 5‐year rate of local control was 98.6% in patients who had radiopaque clips placed versus 91.7% in patients who did not have tumor marker clips placed (P = .02; log‐rank test). On multivariate analysis, the omission of tumor bed clips was associated with a hazard ratio of 3.69 for increased local recurrence compared with patients who did have radiopaque clip placement (P = .083; 95% confidence interval, 0.84‐16.16).

CONCLUSIONS.

The placement of radiopaque clips in patients who were receiving neoadjuvant chemotherapy and breast‐conservation therapy was associated with better local control independent of stage and other clinicopathologic findings. The authors concluded that the placement of tumor‐marker clips should be an integral part of the multidisciplinary approach in appropriate patients. Cancer 2007. © 2007 American Cancer Society.
Is resection of periampullary or pancreatic adenocarcinoma with synchronous hepatic metastasis justified?
Authors: Gleisner Ana Luiza , Assumpcao Lia , Cameron John L. , Wolfgang Christopher L. , Choti Michael A. , Herman Joseph M. , Schulick Richard D. , Pawlik Timothy M.
Published: October 2007

BACKGROUND.

To date, no consensus has been reached regarding which primary tumor subtypes are managed appropriately with hepatic metastectomy. Specifically, the role of hepatic resection for metastatic periampullary or pancreatic adenocarcinoma remains controversial.

METHODS.

Between 1995 and 2005, 1563 patients underwent surgical resection for periampullary carcinoma (n = 608 patients) or pancreatic adenocarcinoma (head, n = 905 patients; tail, n = 50 patients). Data on demographics, operative details, primary tumor status, and—when indicated—extent of hepatic metastasis were collected.

RESULTS.

Of the 1563 patients who underwent resection of periampullary or pancreatic adenocarcinoma, 22 patients (1.4%) underwent simultaneous hepatic resection for synchronous liver metastasis. The primary tumor site was ampullary (n = 1 patient ), duodenal (n = 2 patients), distal bile duct (n = 2 patients), or pancreas (head, n = 10 patients; tail, n = 7 patients). The majority of patients (86.4%) had a solitary hepatic metastasis, and the median size of the largest lesion was 0.6 cm. Hepatic metastectomy included wedge resection (n = 20 patients), segmentectomy (n = 1 patient), and hemihepatectomy (n = 1 patient). After matching patients on primary tumor histology and location, the median survival of patients who underwent hepatic resection of synchronous metastasis was 5.9 months compared with 5.6 months for patients who underwent palliative bypass alone (P = .46) and 14.2 months for patients with no metastatic disease who underwent primary tumor resection only (P < .001). Pancreatic (median, 5.9 months) versus nonpancreatic (median, 9.9 months) primary tumor histology was not associated with a difference in survival in patients who underwent resection of synchronous liver metastasis (P = .43).

CONCLUSIONS.

Even in well selected patients with low‐volume metastatic liver disease, simultaneous resection of periampullary or pancreatic carcinoma with synchronous liver metastases did not result in long‐term survival in the overwhelming majority of patients. Cancer 2007. © 2007 American Cancer Society.