bluuebunny/crossref_metadata_2025 huggingface dataset:
Poly(acrylamide‐co‐maleic acid) hydrogels for removal of Cr(VI) from aqueous solutions, Part 1: Synthesis and swelling characterization
Authors: Bajpai S. K. , Johnson Susamma
Published: February 2006

The swelling behavior of poly (acrylamide‐co‐maleic acid) hydrogels has been investigated in distilled water at 30°C. The gels were characterized with respect to structural parameters, Fourier transform infrared, and thermogravimetric analysis. The gels showed fair pH‐dependent swelling and exhibited double “s”‐shaped curve between equilibrium water uptake and pH of the swelling media. The two pKa values, as determined from the curve, were found to be 2.46 and 6.58. The activation energy of the water uptake process for plain and acid containing gels was found to be 7.93 and 3.26 kJ mol−1 respectively. Similarly, the enthalpy of mixing between dry polymer and solvent showed positive values, thus indicting endothermic nature of the process, and the values increased from 10.06 to 16.29 kJ mol−1 with increase in acid content from 2.1 × 10−1 to 4.7 × 10−1 mM respectively. There was an optimum initiator concentration 24.0 × 10−2 mM and reaction temperature 60°C at which gels synthesized showed maximum absorbency. The dilution of the reaction mixture resulted in the formation of hydrogels with enhanced absorbency. Finally, the gels with varying content of monomer acid in the feed mixture showed different swelling behavior when studied in the medium of pH 1.0 and 7.0. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2759–2769, 2006
Physicomechanical, optical, barrier, and wide angle X‐ray scattering studies of filled low density polyethylene films
Authors: Siddaramaiah  , Guruprasad K. H. , Nagaralli R. T. , Somashekarappa H. , Guru Row T. N. , Somashekar R.
Published: February 2006

Series of low density polyethylene (LDPE) films filled with different fillers such as silica, mica, soya protein isolate, potassium permanganate, and alumina were processed using a single screw extruder. The filled LDPE films were characterized for physicomechanical properties like tensile strength, percentage elongation at break, and tear strength, optical properties like percent transmission and haze. The barrier properties such as water vapor transmission rate and oxygen transmission rate of the filled LDPE films have also been reported. Microcrystalline parameters such as crystal size (〈N〉) and lattice distortion (g) of the filled LDPE films obtained using wide angle X‐Ray scattering method have been reported. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2781–2789, 2006
Synthesis and elastomer behavior of a novel polymer electrolyte of acrylic ester–salt copolymer
Authors: Tang Jianguo , Wang Dongqing , Wang Yao , Liu Haiyan , Wang Xiaomei
Published: February 2006

This paper studied the synthesis of a novel elastomeric copolymer electrolyte in an aqueous phase. The monomer, sodium allyl sulfonate (SAS), was dissolved in continuous aqueous phase and the second monomer, methyl acrylate (MA), was supplied from MA micelles as dispersed phase. The copolymerization of the two monomers took place in continuous aqueous phase. Confirmed by FTIR and 1H‐NMR, a binary copolymer electrolyte of MA and SAS, poly(MA‐co‐SAS), was obtained. The glass transition temperature of the copolymer was indicated as 20.4°C by DSC thermogram, thus, it behaves an elastomer in normal ambient temperature. The mechanical properties of the composite films consisting of both poly(MA‐co‐SAS) and Cu2+ ions or reduced copper were affected by the content of ions and reduced copper. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2796–2802, 2006
The effect of the architecture and concentration of styrene–butadiene compatibilizers on the morphology of polystyrene/low‐density polyethylene blends
Authors: Fortelný Ivan , Šlouf Miroslav , Sikora Antonín , Hlavatá Drahomíra , Hašová Věra , Mikešová Jana , Jacob Ceni
Published: February 2006

The effect of styrene–butadiene block copolymers (SB) with varying number of blocks and length of styrene blocks on the morphology, rheology, and impact strength of 4/1 polystyrene/low‐density polyethylene (PS/LDPE) blends was studied. The scanning and transmission electron microscopy and X‐ray scattering were used for determination of the size of LDPE particles and the localization and structure of SB copolymers in blends. It is shown that the dependence of the LDPE particle size on the amount of added SB and localization of SB copolymers in blends is predominantly controlled by the length of their styrene blocks. It follows from thermodynamic considerations that the reason is the difference in composition asymmetry between SB with short and long styrene blocks. Coalescence of particles of SB having short styrene blocks at the surface of LDPE droplets and movement of SB with long styrene blocks to the PS–LDPE interface were observed during annealing of PS/LDPE/SB blends. Pronounced migration of SB copolymer during annealing shows that their localizations in blends in steady state on long steady mixing and at thermodynamic equilibrium are different. The values of tensile impact strength of PS/LDPE/SB blends correlate well with the size of LDPE particles and the amount of SB at the interface. Viscosity of PS/LDPE/SB depends on molecular structure of SB copolymers by a manner different from that of tensile impact strength. The results of this study and literature data lead to the conclusion that the compatibilization efficiency of SB copolymers for a certain polystyrene‐polyolefin pair is a function of not only molecular parameters of SB but also of the polystyrene/polyolefin ratio, the amount of SB in a blend, and mixing and processing conditions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2803–2816, 2006
Influence of feedback in the structure of carbon plastics on their properties
Authors: Kozlov G. V. , Burya A. I. , Zaikov G. E.
Published: February 2006

The results in the present article allow to find a structural sense of feedback effect in carbon plastics based on phenylone and demonstrated its influence on the strength of these materials. The decrease of feedback parameter can be a result of a substantial increase of carbon plastics macroscopic strength. The control of the value of this parameter is possible by the change of fibers orientation factor, which is the controlling parameter for interfacial regions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2817–2820, 2006
Anisotropy of a fiber structure and the frictional wear of composites on the basis of polyarylate
Authors: Kozlov G. V. , Burya A. I. , Zaikov G. E.
Published: February 2006

An influence of the anisotropy of surface structure of short fibers on an interfacial layer structure in polymer composites is studied. In its turn, mentioned changes of structure cause an essential variation of frictional wear for these materials. In this aspect, the existence of a hydrogen bonds polymer‐filler plays an important role. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2821–2823, 2006
Kinetic and molecular weight control for methyl methacrylate semi‐batch polymerization. I. Modelling
Authors: Wu Jian‐Yi , Shan Guo‐Rong
Published: February 2006

There are gel, glass, and cage effects in the methyl methacrylate (MMA) bulk polymerization. These effects will cause the propagation and termination rate constants and initiator efficiency change during the polymerization process, and make the kinetics and molecular weight more complex. A violent increase of conversion will bring a large amount of reaction heat evolved in a short time, and will promote temperature increase if the heat cannot be removed in time. Molecular weight of polymer will raise ten times at the same time. So, the temperature of polymerization system, kinetics of polymerization, and molecular weight and its distribution of polymer cannot be controlled. To control and unify them, the semibatch polymerization method is preferably selected. Furthermore, the kinetic and molecular weight models for MMA semibatch polymerization with the participation of chain transfer agent and new materials addition flow rate are presented. Using the presented models, the effects of temperature, initiator concentration and type, monomer or solvent concentration, and chain transfer agent concentration and type on the kinetics, and molecular weight and its distribution are simulated in this article. Experimental data of kinetics and molecular weight obtained from the published literature are compared with the simulation results to examine the presented models. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2838–2846, 2006
Fine structural dependence of ultraviolet reflections in the King Penguin beak horn
Authors: Dresp Birgitta , Langley Keith
Published: February 2006

The visual perception of many birds extends into the near‐ultraviolet (UV) spectrum and ultraviolet is used by some to communicate. The beak horn of the King Penguin (Aptenodytes patagonicus) intensely reflects in the ultraviolet and this appears to be implicated in partner choice. In a preliminary study, we recently demonstrated that this ultraviolet reflectance has a structural basis, resulting from crystal‐like photonic structures, capable of reflecting in the near‐UV. The present study attempted to define the origin of the photonic elements that produce the UV reflectance and to better understand how the UV signal is optimized by their fine structure. Using light and electron microscopic analysis combined with new spectrophotometric data, we describe here in detail the fine structure of the entire King Penguin beak horn in addition to that of its photonic crystals. The data obtained reveal a one‐dimensional structural periodicity within this tissue and demonstrate a direct relationship between its fine structure and its function. In addition, they suggest how the photonic structures are produced and how they are stabilized. The measured lattice dimensions of the photonic crystals, together with morphological data on its composition, permit predictions of the wavelength of reflected light. These correlate well with experimentally observed values. The way the UV signal is optimized by the fine structure of the beak tissue is discussed with regard to its putative biological role. © 2006 Wiley‐Liss, Inc.
Alterations in the expression of antioxidant genes and the levels of transcription factor NF‐Kappa B in relation to diabetic embryopathy in the cohen diabetic rat model
Authors: Zangen Sarah W. , Ryu Seonghun , Ornoy Asher
Published: February 2006

BACKGROUND

We have previously shown that oxidative stress is important in the pathogenesis of diabetes‐induced anomalies in Cohen Diabetic sensitive (CDs) rat embryos and seems to interplay with genetic factors. We investigated the role of genetic factors related to the antioxidant defense mechanism in CDs rat embryos.

METHODS

We studied 11.5‐ and 12.5‐day embryos of Cohen Diabetic resistant (CDr) and CDs rats that were fed a regular diet (RD), and hence not diabetic, compared to rats fed a high‐sucrose low‐copper diet (HSD) where only the CDs animals became diabetic. Embryos were monitored for growth and congenital anomalies. mRNA of catalase (CAT), glutathione peroxidase (GSHpx), CuZn‐SOD (SOD‐superoxide dismutase), and Mn‐SOD and the extent of nuclear factor kappa B (NF‐κB) activation were assessed.

RESULTS

Embryos of CDs dams fed RD were significantly smaller and had an increased rate of NTDs compared to embryos of CDr dams fed RD. When CDs dams were fed HSD, >50% of the CDs embryos were dead and 44% of the live embryos had NTDs. Live 11.5‐day old embryos of CDs dams fed RD had a statistically significant increase in CAT, CuZn‐SOD, and GSHpx mRNA levels compared with the levels in the CDr embryos from dams fed RD. CDs embryos from dams fed HSD showed significant overactivation of NF‐κB compared with CDr embryos from dams fed HSD (in which activation was decreased), without any increase in the expression of SOD, CAT, and GSHpx.

CONCLUSIONS

This study demonstrates that one of the genetic differences between the CDr and CDs strains fed RD is an increased expression of genes encoding for antioxidant enzymes in the CDs but inability for upregulation in diabetes. In addition, while activation of NF‐κB is decreased in CDr on HSD, it is increased in the CDs. These differences may play a role in the increased sensitivity of the CDs embryos to diabetic‐induced teratogenicity. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Mouse embryonic stem cells are not susceptible to cytomegalovirus but acquire susceptibility during differentiation
Authors: Matsukage Shoichi , Kosugi Isao , Kawasaski Hideya , Miura Katsutoshi , Kitani Hiroshi , Tsutsui Yoshihiro
Published: February 2006

BACKGROUND

Cytomegalovirus (CMV) is the most significant infectious cause of congenital anomalies of the central nervous system caused by intrauterine infection in humans. The timing of infection and the susceptibility of cells in early gestational stages are not well understood. In this study we investigated the susceptibility of embryonic stem (ES) cells to CMV infection during differentiation.

METHODS

ES cell lines were established from transgenic mice integrated with the murine CMV (MCMV) immediate‐early (IE) promoter connected with a reporter lacZ gene. The susceptibility of the ES cells was analyzed in terms of viral gene expression and viral replication after induction of differentiation.

RESULTS

ES cells were nonpermissive to MCMV infection in the undifferentiated state. Upon differentiation, permissive cells appeared ∼2 weeks after the leukemia inhibitory factor was removed. Upon neural differentiation by retinoic acid (RA), glial cells showed specific susceptibility in terms of expression of the viral antigen. The MCMV IE promoter was not activated in ES cells from the transgenic mice. Activation of the IE promoter was detected ∼2 weeks after induction of differentiation and observed predominantly in glial cells. Upon MCMV infection of the ES cells, viral infection was correlated with the activation of the IE promoter.

CONCLUSIONS

ES cells are nonpermissive to MCMV infection and acquire permissiveness about 2 weeks after induction of differentiation, especially in glial cells. Acquisition of permissiveness in differentiated ES cells may be associated with activation of the IE promoter. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Efficacy and safety of radiofrequency ablation for perivascular hepatocellular carcinoma without hepatic inflow occlusion
Authors: Ng K K , Poon R T , Lam C M , Yuen J , Tso W K , Fan S T
Published: February 2006

Background

The role of radiofrequency ablation (RFA) for perivascular (up to 5 mm from the major intrahepatic portal vein or hepatic vein branches) hepatocellular carcinoma (HCC) is unclear because of possible incomplete tumour ablation and potential vascular damage. This study aimed to evaluate the safety and efficacy of RFA for perivascular HCC without hepatic inflow occlusion.

Methods

Between May 2001 and November 2003, RFA using an internally cooled electrode was performed on 52 patients with perivascular HCC (group 1) through open (n = 39), percutaneous (n = 9), laparoscopic (n = 2) and thoracoscopic (n = 2) approaches. Hepatic inflow occlusion was not applied during the ablation procedure. The perioperative and postoperative outcomes were compared with those of 90 patients with non-perivascular HCC (group 2) treated by RFA during the same period.

Results

The morbidity rate was similar between groups 1 and 2 (25 versus 28 per cent; P = 0·844). One patient in group 1 (2 per cent) and two in group 2 (2 per cent) had developed thrombosis of major intrahepatic blood vessels on follow-up computed tomography scan. There were no significant differences between groups 1 and 2 in mortality rate (2 versus 0 per cent; P = 0·366), complete ablation rate for small HCC (92 versus 98 per cent; P = 0·197), local recurrence rate (11 versus 9 per cent; P = 0·762) and overall survival (1-year: 86 versus 87 per cent; 2-year: 75 versus 75 per cent; P = 0·741).

Conclusion

RFA without hepatic inflow occlusion is a safe and effective treatment for perivascular HCC.
Routine surgical pathology in general surgery
Authors: Matthyssens L E , Ziol M , Barrat C , Champault G G
Published: February 2006

Background

Although pathological analysis provides the definitive diagnosis for most resection specimens, recent evidence suggests that such analysis may be omitted for certain routine samples. This was a retrospective analysis of the value of routine histopathological examination performed in daily general surgical practice.

Methods

All specimens from routine appendicectomies, cholecystectomies, haemorrhoidectomies and inguinal hernia repairs performed between 1993 and 2002 were included. The analysis included a comparison of histological and macroscopic diagnoses, review of preoperative and peroperative findings, and an evaluation of the consequences of routine histopathological assessment on patient management and costs.

Results

With the exception of hernia specimens, the rate of submission for routine pathological evaluation was 100 per cent. No hernia sac specimen from more than 2000 interventions revealed aberrant histological findings. Of 311 haemorrhoidectomy specimens three showed malignancy, all of which had a suspicious macroscopic appearance. Of 1465 appendices, only one (0·1 per cent) had a potentially relevant histological diagnosis that was not suspected macroscopically. Among 1523 cholecystectomy specimens, all adenomas (0·6 per cent) and carcinomas (0·4 per cent) were suspected macroscopically or developed in association with a known disease.

Conclusion

The rarity of incidental histological findings relevant to patient management, especially in the absence of macroscopic abnormalities, suggests that routine histological examination of certain specimens may be omitted. A more elementary role for macroscopic examination of the specimen by the surgeon and the pathologist is proposed.
The effect of temperature on the analysis of metanephrine for catechol‐O‐methyltransferase activity assay by HPLC with electrochemical detection
Authors: Passarinha L. A. , Bonifácio M. J. , Queiroz J. A.
Published: February 2006

The enzyme catechol‐O‐methyltransferase (COMT) plays an important role in the metabolism of catechol estrogens and degradation of the catecholamine neurotransmitters, such as epinephrine. Several analytical methods, mainly high‐performance liquid chromatography with electrochemical amperometric detection, have been reported for the analysis of catecholamines and their metabolites in biological fluids. In this paper we report the relevance of controlling temperature in calibration procedures of metanephrine, an O‐methylated product of catechol‐O‐methyltransferase, using epinephrine as substrate. The results at higher temperatures show shorter retention times of metanephrine, no undue band‐broadening and increased electro signals. This study also showed that, despite different temperatures leading to similarly specific activities of recombinant human COMT as expected, there are additional advantages in flow analytical methods where good sensitivity, efficiency and selectivity is required, mainly in tissues with low levels of COMT activity. Copyright © 2006 John Wiley & Sons, Ltd.
Implementation of 3D mesh streaming and compression techniques in NVEs
Authors: Bouras Christos J. , Panagopoulos Alexandros , Tsiatsos Thrasyvoulos
Published: February 2006

In this paper, we present a framework that integrates three‐dimensional (3D) mesh streaming and compression techniques and algorithms into our EVE‐II networked virtual environments (NVEs) platform, in order to offer support for large‐scale environments as well as highly complex world geometry. This framework allows the partial and progressive transmission of 3D worlds as well as of separate meshes, achieving reduced waiting times for the end‐user and improved network utilization. We also present a 3D mesh compression method focused on network communication, which is designed to support progressive mesh transmission, offering a fast and effective means of reducing the storage and transmission needs for geometrical data. This method is integrated in the above framework and utilizes prediction to achieve efficient lossy compression of 3D geometry. Copyright © 2006 John Wiley & Sons, Ltd.
Hydraulic erosion
Authors: Beneš Bedřich , Těšínský Václav , Hornyš Jan , Bhatia Sanjiv K.
Published: February 2006

This paper presents a generalized solution to modelling hydraulic erosion using ideas from fluid mechanics. The model is based on the Navier–Stokes equations, which provide the dynamics of velocity and pressure. These equations form the basis for the model to balance erosion and deposition that determine changes in the layers between water and erosion material. The eroded material is captured and relocated by water according to a material transport equation. The resulting model is fully 3D and is able to simulate a variety of phenomena including river meanders, low hill sediment wash, natural water springs and receding waterfalls. The simulations show the terrain morphogenesis and can be used for animations as well as for static scene generation. Copyright © 2006 John Wiley & Sons, Ltd.
Chloroplastic Glycolipids Fuel Aldehyde Biosynthesis in the Marine Diatom Thalassiosira rotula
Authors: Cutignano Adele , d'Ippolito Giuliana , Romano Giovanna , Lamari Nadia , Cimino Guido , Febbraio Ferdinando , Nucci Roberto , Fontana Angelo
Published: February 2006

Enzymatic preparations and specialized analytical tools have shown that chloroplast‐derived glycolipids are the main substrates for the biosynthetic pathway that produces antiproliferative polyunsaturated aldehydes in broken cells of the marine diatom Thalassiosira rotula. This process, which is associated with the formation of free fatty acids and lyso compounds from polar lipids but not triglycerides, is largely dependent on glycolipid hydrolytic activity, rather than phospholipase A2 as previously suggested. Preliminary characterization of lipolytic enzymes has revealed protein bands of 40–45 kDa. Under native conditions these proteins seem to be associated with soluble aggregates that have an apparent molecular weight of approximately 200 kDa. The biochemical process, which is similar to that described in the algal‐bloom forming diatom Skeletonema costatum, suggests a mechanism based on decompartmentalization and mixing of preexisting enzymes and substrates.
Aminopeptidase P Mediated Detoxification of Organophosphonate Analogues of Sarin: Mechanistic and Stereochemical Study at the Phosphorus Atom of the Substrate
Authors: Huang Li‐Fang , Su Benson , Jao Shu‐Chuan , Liu Kwang‐Ting , Li Wen‐Shan
Published: February 2006

The activity of the aminopeptidase P from Escherichia coli in hydrolyzing a series of organophosphonate sarin analogues (1–6) was evaluated. The enzymatic rates of hydrolysis for methylphosphonate 1 with a methoxy group attached to the phosphorus center were 7‐ to 15‐fold higher than those for the corresponding analogues 2–6. Double mutant R153W/R370L was able to hydrolyze the Sp enantiomer of racemic 1 at a considerable rate. This mutant allowed the preparation of the Rp isomer of the sarin analogue 1. All the mutants, R370L, R153A, W88L, R153L/R370L, and R153W/R370L, preferred the formation of (Sp)‐8 to that of the corresponding (Rp)‐8 enantiomer and displayed a better enantiomeric excess of products, by 1.4‐ to 2‐fold as compared to the wild‐type enzyme. Enzymatic hydrolysis of O,O‐diisopropyl‐p‐nitrophenyl phosphate (9) in H218O led to the formation of the 18O‐labeled O,O‐diisopropyl phosphate product and confirmed that the catalytic reaction starts with cleavage of the PO bond. From chemical and kinetic studies, the utilization of an optically pure Sp enantiomer of O‐methyl‐p‐nitrophenyl methylphosphonothioate ((Sp)‐MNMPT, 7) has demonstrated that the enzymatic reaction proceeds through a displacement mechanism and generates a chiral product in situ with an inversion of stereochemical configuration at the phosphorus atom. The results also lead to the conclusion that alteration of the active site through site‐directed mutagenesis can result in a preference for (Sp)‐MNMPT (7) rather than the Rp isomer.
The Structural Basis for Docking in Modular Polyketide Biosynthesis
Authors: Weissman Kira J.
Published: February 2006

Polyketide natural products such as erythromycin and rapamycin are assembled on polyketide synthases (PKSs), which consist of modular sets of catalytic activities distributed across multiple protein subunits. Correct protein–protein interactions among the PKS subunits which are critical to the fidelity of biosynthesis are mediated in part by “docking domains” at the termini of the proteins. The NMR solution structure of a representative docking domain complex from the erythromycin PKS (DEBS) was recently solved, and on this basis it has been proposed that PKS docking is mediated by the formation of an intermolecular four‐α‐helix bundle. Herein, we report the genetic engineering of such a docking domain complex by replacement of specific helical segments and analysis of triketide synthesis by mutant PKSs in vivo. The results of these helix swaps are fully consistent with the model and highlight residues in the docking domains that may be targeted to alter the efficiency or specificity of subunit–subunit docking in hybrid PKSs.
Frontal Polymerization Synthesis of Starch‐Grafted Hydrogels: Effect of Temperature and Tube Size on Propagating Front and Properties of Hydrogels
Authors: Yan Qing‐Zhi , Zhang Wen‐Feng , Lu Guo‐Dong , Su Xin‐Tai , Ge Chang‐Chun
Published: February 2006

The frontal polymerization process was used to produce superabsorbent hydrogels based on acrylic acid monomers grafted onto starch. Using a simple test tube which was nonadiabatic and permitted contact with air, the effects of initial temperature and tube size on the propagating front of grafting copolymerization and the properties of hydrogels were explored. The unrestricted access of the reaction mixture to oxygen delayed the formation of self‐propagating polymerization front. The ignition time was markedly lengthened with the increasing of tube size attributed to the formation of large amounts of peroxy radicals. The front velocity dependence on initial temperature could be fit to an Arrhenius function with the average apparent activation energy of 24 kJ mol−1, and on tube size to a function of higher order. The increase of the initial temperature increased the front temperature, which lead to more soluble oligomers and higher degree of crosslinking. The interplay of two opposite effects of oligomer and crosslinking determined the sol and gel content. An increase in tube size had two effects on the propagating front. One was to reduce heat loss. The other effect was to increase the number of escaping gas bubbles. The combined action of the two effects resulted in a maximum value of front temperature, an increase in sol content and a reduction in gel content with tube size. The highest swelling capacity of hydrogels was obtained when the initial temperature or tube size favored a formation of porous microstructure of hydrogels.
Helical Stacking Tuned by Alkoxy Side Chains in π‐Conjugated Triphenylbenzene Discotic Derivatives
Authors: Bao Chunyan , Lu Ran , Jin Ming , Xue Pengchong , Tan Changhui , Xu Tinghua , Liu Guofa , Zhao Yingying
Published: February 2006

We report on the synthesis and self‐assembly of a new series of discotic molecules containing triphenylbenzene as the core and alkoxy side chain with varying length. It was found that compounds 3 a–c, 4 b and 5 b could form stable gels in several apolar solvents. Transmission electron microscopy (TEM) images revealed that their morphologies were very different for the different alkoxy‐substituted organogels. In toluene or hexane, 3 b and 3 c resulted in both left‐ and right‐handed helical fibers, whereas 3 a resulted in straight rigid fibers; 4 b and 5 b resulted in most straight fibers with a few twisted fibers. The results from FT‐IR and UV/Vis absorption spectroscopy indicated that the hydrogen bonding and π–π interactions were the main driving forces for the formation of the self‐assembled gels. Further detailed analysis of their aggregation modes were conducted by UV‐visible absorption spectra and X‐ray diffraction (XRD) measurements. Based on these findings, the influence of these peripheral alkoxy substituents on the gel formation and the aggregation mode were discussed. The special enhanced fluorescent emissions, which resulted from aggregation, were also found in the gel phase.
Wire‐Type Ruthenium(II) Complexes with Terpyridine‐Containing [2]Rotaxanes as Ligands: Synthesis, Characterization, and Photophysical Properties
Authors: Davidson Gregory J. E. , Loeb Stephen J. , Passaniti Paolo , Silvi Serena , Credi Alberto
Published: February 2006

[2]Rotaxanes based on the 1,2‐bis(pyridinium)ethane⊂[24]crown‐8 ether motif were prepared that contain a terminal terpyridine group for coordination to a transition‐metal ion. These rotaxane ligands were utilized in the preparation of a series of heteroleptic [Ru(terpy)(terpy–rotaxane)]2+ complexes. The compounds were characterized by 1D and 2D 1H NMR spectroscopy, X‐ray crystallography, and high‐resolution electrospray ionization mass spectrometry. The effect of using a rotaxane as a ligand was probed by UV/Vis/NIR absorption and emission spectroscopy of the RuII complexes. In contrast with the parent [Ru(terpy)2]2+ complex, at room temperature the examined complexes exhibit a luminescence band in the near infrared region and a relatively long lived triplet metal‐to‐ligand charge‐transfer (3MLCT) excited state, owing to the presence of strong‐electron‐acceptor pyridinium substituents on one of the two terpy ligands. Visible‐light excitation of the Ru‐based chromophore in acetonitrile at room temperature causes an electron transfer to the covalently linked 4,4′‐bipyridinium unit and the quenching of the MLCT luminescence. The 3MLCT excited state, however, is not quenched at all in rigid matrix at 77 K. The rotaxane structure was found to affect the absorption and luminescence properties of the complexes. In particular, when a crown ether surrounds the cationic axle, the photoinduced electron‐transfer process is slowed down by a factor from 2 to 3. Such features, together with the synthetic and structural advantages offered by [Ru(terpy)2]2+‐type complexes compared to, for example, [Ru(bpy)3]2+‐type compounds, render these rotaxane–metal complexes promising candidates for the construction of photochemical molecular devices with a wire‐type structure.
Metal Nuclearity Modulated Four‐, Six‐, and Eight‐Connected Entangled Frameworks Based on Mono‐, Bi‐, and Trimetallic Cores as Nodes
Authors: Wang Xin‐Long , Qin Chao , Wang En‐Bo , Su Zhong‐Min
Published: February 2006

To investigate the relationship between network connectivity and metal nuclearity, we designed and synthesized a series of three‐dimensional (3D) entangled coordination frameworks based on different metal cores, namely [Zn2(bdc)2(L)2]⋅2H2O (1), [Zn(bdc)(L)0.5] (2), [Zn(oba)(L)0.5] (3) and [Cd3(bdc)3(L)2(H2O)2] (4) by self‐assembly of d10 metal salts with the flexible long‐chain ligand 1,4‐bis(1,2,4‐triazol‐1‐yl)butane (L), and with the rigid and nonrigid aromatic dicarboxylate ligands 1,4‐benzenedicarboxylate (bdc) and 4,4′‐oxybis(benzoate) (oba). Compound 1 exhibits a threefold interpenetrated diamondoid array typically based on a tetrahedral second building unit (SBU) at a single Zn center. Compound 2 adopts a threefold interpenetrated α‐polonium‐type network that is built from bimetallic cores as six‐connected vertices. The structure of 3 also consists of dinuclear units; it comprises a novel (3,4)‐connected threefold interpenetrated net with complex (4⋅6⋅10)(4⋅62⋅103) topology when single zinc centers act as four‐connected nodes (or the α‐Po topology if dinuclear units are considered as six‐connected nodes). Compound 4, derived from a crosslinked fivefold interpenetrated diamond‐like substructure, is an unusual example of a self‐penetrating coordination framework displaying an unprecedented eight‐connected 42068 topology with trinuclear cadmium clusters as eight‐connected nodes which, to our knowledge, not only defines a new topology for eight‐connected coordination networks, but also represents the highest connected topology presently known for self‐penetrating systems. Detailed structural comparison of these complexes indicates that the increase in metal nuclearity induces the progressive increase in the connectivities of the ultimate nets: that is, the metal nuclearity plays a significant role in tuning the connectivity of a specific network. The thermal and luminescent properties of these compounds are discussed.
Synthesis of 7‐Deoxypancratistatin from Carbohydrates by the Use of Olefin Metathesis
Authors: Håkansson Anders E. , Palmelund Anders , Holm Henriette , Madsen Robert
Published: February 2006

The stereocontrolled synthesis of (+)‐7‐deoxypancratistatin is described. The convergent synthesis has been achieved by two different strategies, both of which commence from a pentose and piperonal. The latter is converted into allylic bromide 7, which is then coupled with a protected methyl 5‐deoxy‐5‐iodo‐D‐ribofuranoside in the presence of zinc metal. The first strategy involves a total of only 13 steps from D‐ribose and piperonal, but suffers from a low yield in the zinc‐mediated reaction between ribofuranoside 9, benzylamine, and bromide 7. The second strategy involves a total of 18 steps from D‐xylose and piperonal. The former is converted into ribofuranoside 28, which is coupled with bromide 7 in the presence of zinc, and this is followed by ring‐closing olefin metathesis. Subsequent Overman rearrangement, dihydroxylation, and deprotection then affords the natural product.
K5[FeO4] and K17[Fe5O16]: Two New Potassium Oxoferrates(III).
Authors: Frisch Gero , Roehr Caroline
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Electrochemical Lithium Insertion in Zn3P2 Zinc Phosphide.
Authors: Bichat Marie‐Pierre , Pascal Jean‐Louis , Gillot Frederic , Favier Frederic
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Methoxide of an Anderson‐Type Polyoxometalate and Its Conversion to a New Type of Species, [IMo9O32(OH)(OH2)3] 4‐.
Authors: Honda Daisuke , Ozeki Tomoji , Yagasaki Atsushi
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Metal—Metal Bond or Isolated Metal Centers? Interaction of Hg(CN)2 with Square Planar Transition Metal Cyanides.
Authors: Joszai Robert , Beszeda Imre , Benyei Attila C. , Fischer Andreas , Kovacs Margit , Maliarik Mikhail , Nagy Peter , Shchukarev Andrey , Toth Imre
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Copper‐Catalyzed Addition Reaction of γ,γ‐Dialkoxyallylic Zirconium Species with Imines.
Authors: Sato Azusa , Ito Hisanaka , Okada Midori , Nakamura Yuko , Taguchi Takeo
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cyclic and Acyclic Sulfonimides in Reactions with Rh(II)‐Ketocarbenoids: A New Access to Chemoselective O‐Functionalization of the Imidic Carbonyl Groups.
Authors: Nikolaev Vsevolod , Hennig Lothar , Sieler Jochim , Rodina Ludmila , Schulze Barbel , Nikolaev Valerij
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Application of O‐Xylylenebis(triphenylphosphonium Peroxymonosulfate) for Selective Oxidation of Benzylic Alcohols and Hydroquinones.
Authors: Tajbakhsh Mahmoud , Lakouraj Moslem‐Mansor , Yadoolahzadeh Khadijeh
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New Alternative to Stryker′s Reagent in Hydrosilylation: Synthesis, Structure, and Reactivity of a Well‐Defined Carbene—Copper(II) Acetate Complex.
Authors: Yun Jaesook , Kim Daesung , Yun Hoseop
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rhodium Nanoparticles Entrapped in Boehmite Nanofibers: Recyclable Catalyst for Arene Hydrogenation under Mild Conditions.
Authors: Park In Soo , Kwon Min Serk , Kim Namdu , Lee Jae Sung , Kang Kyung Yeon , Park Jaiwook
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Indium(III) Triflate Catalyzed Tandem Azidation/1,3‐Dipolar Cycloaddition Reaction of ω,ω‐Dialkoxyalkyne Derivatives with Trimethylsilyl Azide.
Authors: Yanai Hikaru , Taguchi Takeo
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mizoroki—Heck Type Arylation of Alkenes Using Aroyl Chlorides under Base‐Free Conditions.
Authors: Sugihara Toru , Satoh Tetsuya , Miura Masahiro
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Highly Efficient Synthetic Protocol for Tetrahydropyranylation/Depyranylation of Alcohols and Phenols.
Authors: Khan Abu T. , Ghosh Subrata , Choudhury Lokman H.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Preparation and Synthetic Application of a Novel Ketene Silyl Acetal of Methyl Trifluoropyruvate.
Authors: Takikawa Go , Katagiri Toshimasa , Uneyama Kenji
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Diels—Alder Reaction Promoted by Achiral Functionalization of a SiO2‐Supported Cu‐BOX [Bis(oxazoline)] Catalyst.
Authors: Tada Mizuki , Tanaka Satoka , Iwasawa Yasuhiro
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Oxidative Nucleophilic Substitution of Hydrogen in Nitroarenes with Phenylacetic Acid Derivatives.
Authors: Makosza Mieczyslaw , Kamienska‐Trela Krystyna , Paszewski Maciej , Bechcicka Malgorzata
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Efficient One‐Step Method for the Conversion of β‐(Dimethylamino)styrenes into Arylacetonitriles.
Authors: Starosotnikov Alexey M. , Lobach Alexander V. , Shevelev Svyatoslav A.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Microwave‐Assisted Cross‐Coupling Reaction of Alkynylstibane with Aryl Iodides in the Presence of Ammonium Salt.
Authors: Kakusawa Naoki , Kurita Jyoji
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Functionalized 2‐Alkylidene‐tetrahydrofurans Based on a [3 + 2] Cyclization/Bromination/Palladium(0) Cross‐Coupling Strategy.
Authors: Bellur Esen , Langer Peter
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Substituted Benzo[e,f]‐s‐indaceno[2,3‐d]pyrazoles.
Authors: Goel Sharda
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Expedient Synthesis of Substituted Imidazoles from Nitriles.
Authors: Frutos Rogelio P. , Gallou Isabelle , Reeves Diana , Xu Yibo , Krishnamurthy Dhileepkumar , Senanayake Chris H.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A New Route to 3,4‐Disubstituted Piperidines: Formal Synthesis of (‐)‐Paroxetine and (+)‐Femoxetine.
Authors: Yamada Shinji , Jahan Ishrat
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis, Characterization and Antimicrobial Activities of Fused 1,6‐Naphthyridines.
Authors: Suresh T. , Dhanabal T. , Kumar R. Nandha , Mohan P. S.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Three‐Component Reaction of 2‐Aminobenzothiazole with Methylene‐Active Carbonyl Compounds and Aldehydes.
Authors: Pavlenko A. A. , Shikhaliev Kh. S. , Potapov A. Yu. , Krylsky D. V.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Novel One‐Pot Three‐Component Reaction: Synthesis of Triheterocyclic 4H‐Pyrimido[2,1‐b]benzazoles Ring Systems.
Authors: Shaabani Ahmad , Rahmati Abbas , Naderi Soheila
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of Some Benzotriazole‐Substituted Perimidines.
Authors: Mobinikhaledi A. , Foroughifar N. , Goli R.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Use of Tetramethylthiuram Disulfide (II) in Synthesis of Nitrogen‐Containing Heterocyclic Compounds
Authors: Demchenko A. M. , Yanchenko V. A. , Kisly V. V. , Lozinskii M. S.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Radical Opening Reaction of Glucosyl 1,2‐Cyclopropane Derivatives: Synthesis of α and β C‐Glycosides and Oxepane Derivatives.
Authors: Kar Paramita , Nagaiah K. , Gurjar M. K.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis and Antiviral Activity of 1‐{[2‐(Phenoxy)ethoxy]methyl}uracil Derivatives.
Authors: Novikov M. S. , Ozerov A. A. , Orlova Yu. A. , Buckheit R. W.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of the Thiopeptide Antibiotic Amythiamicin D (I).
Authors: Hughes Rachael A. , Thompson Stewart P. , Alcaraz Lilian , Moody Christopher J.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Total Synthesis of Piericidin A1 and B1.
Authors: Schnermann Martin J. , Boger Dale L.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Enantioselective Synthesis and Absolute Configurations of Aculeatins A and B.
Authors: Falomir Eva , Alvarez‐Bercedo Paula , Carda Miguel , Marco J. Alberto
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Hydrothermal Synthesis of Delafossite‐Type Oxides
Authors: Sheets William C. , Mugnier Emmanuelle , Barnabe Antoine , Marks Tobin J. , Poeppelmeier Kenneth R.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rare Earth Doped Confined Structures for Lasers and Amplifiers
Authors: Jacquier B. , Bigot L. , Guy S. , Jurdyc A. M.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Variable‐Valent Rhenium Chemistry of Conjugated Nitrogenous Ligands: Structure and Reactivity
Authors: Chakravorty Animesh
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Taking Advantage of Luminescent Lanthanoid Ions
Authors: Buenzli Jean‐Claude G. , Piguet Claude
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Playing with Podands Based on Cone‐Shaped Cavities. How Can a Cavity Influence the Properties of an Appended Metal Center?
Authors: Jeunesse Catherine , Armspach Dominique , Matt Dominique
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Engineering Crystal by the Strategy of Molecular Tectonics
Authors: Wuest James D.
Published: February 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.