bluuebunny/crossref_metadata_2025 huggingface dataset:
Molecular Packing Prediction and Periodic Calculations on Three Polynitroadamantanes as Potential High Energy Density Compounds
Authors: XU Xiao‐Juan , ZHU Wei‐Hua , XIAO He‐Ming
Published: April 2008

The DREIDING force field was chosen to predict the molecular packings for the three polynitroadamantanes (PNAs) with 8–10 ‐NO2 among the 7 most possible space groups (P21/c, P‐1, P212121, P21, Pbca, C2/c and Pna21) using molecular mechanics (MM) method, respectively. Then, ab inito periodic calculations were performed on the three predicted crystals using the DFT‐GGA‐RPBE method. Density of states (DOS) calculations showed that C–N bond was the trigger bond of PNA during thermolysis; band gaps (ΔE) were used to predict their relative sensitivity. All of these are consistent well with those drawn from bond dissociation energy calculation on gas molecules. Besides, our calculations present that variations of PNAs molecular structures from gas to crystal become smaller with the number of ‐NO2 groups increasing.
Ionic Liquid Catalyst Used in Deep Desulfuration of the Coking Benzene for Producing Sulfurless Benzene
Authors: ZHOU Xia‐Ping , WANG Yan‐Liang , MENG Fan‐Wei , FAN Xing‐Ming , QIN Song‐Bo
Published: April 2008

For the widening need of benzene used in organic synthesis, ionic liquid catalyst was prepared to study the process of deep desulfuration in the coking benzene. The result shows that the effect of de‐thiophene by the ionic liquid catalyst (N‐methyl imidazolium hydrogen sulfate [Hmim][HSO4]) is related to its acid function value. Hammett indicator was used to determine the acid function value H0 of the ionic liquid. It can be concluded that while the acid function value is in the range from −4 to −12, the ionic liquid catalyst can make the concentration of thiophene in the coking benzene be under 0.5 mg·L−1. Similarly to the catalytic mechanism of solid acid, with a certain acid quantity and strength, the ionic liquid catalyst helps to form alkyl thiophene through Friedel‐Crafts reaction, which differs from the character of benzene and it is absolutely necessary for the separation and refinement of benzene. But overabundant quantity and higher acid value of [Hmim][HSO4] are more suitable for the side copolymerization of benzene, thiophene and alkene, thereby affecting repeated use of the ionic liquid catalyst([Hmim][HSO4]). In our research, thiophene derivant produced by desulfurization in the coking benzene was used as the polymer to provide the passing channel of the charges. The ionic liquid composition in poor performance after repeated use was made to prepare conductive material (resisting to static electricity) as an "electron‐receiving" and "electron‐giving" doping agent. The result shows that thiophene derivant after desulfuration in the coking benzene can be used to prepare doping conductive materials.
A Novel One‐dimensional Reduced Molybdenum(V) Decorated with Nickel Coordination Cations:Ni[Mo6O12(OH)3(PO4)(HPO4)3]2[Ni(H2O)2][Ni(H2O)(bipy)2]4·5H2O
Authors: GUO Hong‐Xu , WANG Qing‐Hua , CHEN Chen , LIANG Min , CHEN Ling
Published: April 2008

A novel molybdenum(V) phosphate decorated with nickel complex cations, Ni[Mo6O12(OH)3(PO4)(HPO4)3]2‐[Ni(H2O)2][Ni(H2O)(bipy)2]4·5H2O (bipy2,2′‐bipyridyl), has been hydrothermally synthesized and characterized by IR, TGA and single‐crystal X‐ray diffraction. Two {Mo6P4} clusters are linked via one Ni cation to form a Ni[Mo6P4]2 dimer unit, which is further connected together by additional nickel coordination complex ions to give 1‐D molybdenum(V) phosphate chain‐like structure. A probe reaction of the oxidation of benzaldehyde with H2O2 using the title compound as catalyst was carried out in a liquid‐solid system, showing that the compound had high oxidative catalytic activity to the reaction.
Synthesis, Crystal Structure and Characterization of [Ca(L)(H2O)2]n Constructed by Flexible Ligand 2‐Nitro‐benzene‐1,4‐di(oxyacetate)
Authors: YANG Li , YU Wei , ZHANG Tong‐Lai , ZHANG Jian‐Guo , HU Xiao‐Chun , LIU Zhen‐Hua , WANG Shao‐Zong
Published: April 2008

A new microporous coordination polymer [Ca(nbdo)(H2O)2]n, constructed by 2‐nitro‐benzene‐1,4‐di(oxyace‐tate), was obtained by a slow evaporation method and characterized by elemental analysis, FT‐IR, single‐crystal X‐ray diffraction, DSC, TG‐DTG and fluorescent spectral analysis. The crystal structure reveals that there is 1‐D microporous channel, which is bridged by four kinds of hydrogen bonds to generate a 3‐D supramolecular network. The thermal analysis of the complex shows that it began to lose water molecules at 375 K, and when the temperature was up to 550 K the framework of the coordination polymer began to collapse. The luminescence property was investigated and the complex shows photoluminescence in the solid state at room temperature, excited at 320 nm.
1D Ladder‐like Chain and 1D Channeled 3D Supramolecular Architectures Based on Benzophenone‐2,4′‐dicarboxylic Acid
Authors: YANG Xiao‐Gang , LI Dong‐Sheng , FU Feng , WU Ya‐Pan , WANG Ji‐Jiang , WANG Yao‐Yu
Published: April 2008

The hydrothermal reactions of AgNO3, 2,2′‐bipyridyl, and benzophenone‐2,4′‐dicarboxylic acid gave rise to two 3D supramolecular architectures, namely H2L·H2O (1), [Ag(bpy)2]·HL·H2O (2) (bpy2,2′‐bipyridyl, H2Lbenzophenone‐2,4′‐dicarboxylic acid). The two compounds are extended by hydrogen bonds in two different approaches. In the case of 1, one‐dimensional ladder‐like structure is firstly formed through O–H···O hydrogen bonding between H2L ligands and water molecules, then extended to a 3D supramolecular architecture. Compound 2 possesses 3D supramolecular architecture containing 1D open channels, which are driven due to the strong H‐bonding interactions occurring between the HL anions and water molecules; interestingly, [Ag(bpy)2]+ cations are linked together through π‐π interactions between bpy ligands and weak Ag···Ag interactions, and then reside in these channels by C–H···O hydrogen‐bond. The photoluminescence properties of these compounds were also investigated, the emission maxima for 2 exhibits red‐shift compared with that of free ligand and 1 due to chelating effect of the 2,2′‐bipyridine ligand to the silver ion and the presence of aromatic π‐packing.
Synthesis of Four Triazole Compounds and Their Corrosion Inhibitive Effect on Carbon Steel in Hydrochloric Acid Medium
Authors: ZHANG Xiao‐Ru , XU Min‐Hua , ZHANG Shu‐Sheng
Published: April 2008

Four new 1,2,3‐triazoles (3a, 3b, 4a and 4b) have been synthesized selectively via click chemistry approach and characterized by elemental analysis, IR, 1H NMR, 13C NMR and single crystal X‐ray crystallographic analysis. The inhibiting action of these compounds against the corrosion of carbon steel in 1.0 mol/L HCl solution was investigated by electrochemical techniques including polarization and electrochemical impedance spectroscopy (EIS), both results of which indicate that these compounds act as good anodic inhibitors. The electrochemical study also shows that 4b is the best inhibitor among the four compounds in this work and its efficiency increases with concentration. The obtained highest IE (inhibition efficiency) of 4b is around 97%.
Thermodynamic Equilibrium Morphology Prediction of Polyurethane/Polyacrylate Composite Latex Particles
Authors: CHAI Shu‐Ling , JIN Ming‐Martin
Published: April 2008

Composite particles were prepared by seeded surfactant‐free batch emulsion polymerization at 80 °C using K2S2O8 as an initiator, and polyurethane aqueous dispersion as seed particles. The acrylate monomers were continuously added into the reactor under a starving condition in the second stage polymerization. The synthesized hybrid emulsions were found to form an inverted core‐shell structure with polyacrylate as the core and with polyurethane as the shell from the observation with a transmission electron microscope. The interfacial tensions between polymer and polymer as well as polymer and water were calculated with a simple method according to harmonic mean equation and used in a mathematical model based on the minimum interfacial energy change principle to predict the equilibrium morphology. The observed particle morphologies were in good agreement with the predicted ones. The surface properties of the dried films formed from polyurethane (PU)/polyacrylate (PA) composite emulsions were also studied by contact angle measurements, showing that the shell part of the composite emulsions is preferentially oriented toward the surface layers of the dried films.
A One‐pot, Stereoselective Synthesis of (Z)‐2‐Sulfonyl‐Substituted 1,3‐Enynes by Hydrostannylation‐Stille Tandem Reaction of Acetylenic Sulfones
Authors: ZHAO Hong , ZHANG Hai‐Yun , CAI Ming‐Zhong
Published: April 2008

(Z)‐2‐Sulfonyl‐substituted 1,3‐enynes can be stereoselectively synthesized in one pot by the palladium‐catalyzed hydrostannylation of acetylenic sulfones, followed by Stille coupling with alkynyl bromides. The present method has the advantages of readily available starting materials, straightforward and simple procedures, mild reaction conditions and good yields.
Synthesis of Somatostatin Mimetics Based on 1‐Deoxynojirimycin
Authors: Chagnault Vincent , Lalot Jérôme , Murphy Paul V.
Published: April 2008

The synthesis of novel somatostatin mimetics from 1‐deoxynojirimycin (DNJ) is described. The dipeptide mimetic, which respectively displayed the side chains of tryptophan and lysine at the nitrogen and O6 atoms of the iminosugar scaffold is a ligand (Ki=3.2 μM) for the human somatostatin receptor subtype 4 (hSSTR4) but has lower affinity (Ki>100 μM) for hSSTR5. A benzylated analogue of the Trp‐Lys mimetic displays higher affinity for hSSTR5 (Ki=5 μM).
Ion transport peptide splice forms in central and peripheral neurons throughout postembryogenesis of Drosophila melanogaster
Authors: Dircksen Heinrich , Tesfai Lily Kahsai , Albus Christina , Nässel Dick R.
Published: April 2008

Ion transport peptides (ITPs) belong to a large arthropod neuropeptide family including crustacean hyperglycaemic hormones and are antidiuretic hormones in locusts. Because long and short ITP isoforms are generated by alternative splicing from a single gene in locusts and moths, we investigated whether similarly spliced gene products occur in the nervous system of Drosophila melanogaster throughout postembryogenesis. The itp gene CG13586 was reanalyzed, and we found three instead of the two previously annotated alternatively spliced mRNAs. These give rise to three different neuropeptides, two long C‐terminally carboxylated isoforms (DrmITPL1 and DrmITPL2, both 87 amino acids) and one short amidated DrmITP (73 amino acids), which were partially identified biochemically. Immunocytochemistry and in situ hybridization reveal nine larval and 14 adult identified neurons: four pars lateralis neurosecretory neurons, three hindgut‐innervating neurons in abdominal ganglia, and a stage‐specific number of interneurons and peripheral bipolar neurons. The neurosecretory neurons persist throughout postembryogenesis, form release sites in corpora cardiaca, and invade corpora allata. One type of ITP‐expressing interneuron exists only in the larval and prepupal subesophageal ganglia, whereas three types of interneurons in the adult brain arise in late pupae and invade circumscribed neuropils in superior median and lateral brain areas. One peripheral bipolar and putative sensory neuron type occurs in the larval, pupal, and adult preterminal abdominal segments. Although the neurosecretory neurons may release DrmITP and DrmITPL2 into the haemolymph, possible physiological roles of the hindgut‐innervating and peripheral neurons as well as the interneurons are yet to be identified. J. Comp. Neurol. 509:23–41, 2008. © 2008 Wiley‐Liss, Inc.
The Electrochemical Grafting of a Mixture of Substituted Phenyl Groups at a Glassy Carbon Electrode Surface
Authors: Louault Cyril , D'Amours Mathieu , Bélanger Daniel
Published: April 2008

Two‐component substituted aryl groups are simultaneously grafted onto the surface of a glassy carbon electrode by electrochemical reduction of a binary mixture of two aryl diazonium salts in acetonitrile. The electrochemical deposition is achieved potentiostatically and two different mixtures with four different ratios of diazonium salts are used. The binary mixtures comprise: 1) 4‐nitrophenyl diazonium and 4‐bromophenyl diazonium cations and 2) 4‐bromophenyl diazonium and N,N‐diethylaniline diazonium cations. The chemical composition of the two component films is determined by cyclic voltammetry in an electrolyte inert for electroactive groups such as nitrophenyl and bromophenyl. X‐ray photoelectron spectroscopy is also used to evaluate the surface concentration of each grafted substituted phenyl group. The surface concentration of the substituted phenyl group for which the corresponding diazonium cation is the most easily reduced is higher than its concentration in the mixture of the deposition solution. The usefulness of binary films is also discussed.
Cytopathologist‐performed ultrasound‐guided fine‐needle aspiration and core‐needle biopsy: A prospective study of 500 consecutive cases
Authors: Lieu David
Published: April 2008

In experienced hands, palpation‐guided fine‐needle aspiration is an excellent diagnostic tool. However, there is a movement toward using imaging guidance to target all masses. This study examines the feasibility of cytopathologist‐performed ultrasound‐guided FNA (UG‐FNA) and ultrasound‐guided core‐needle biopsy (UG‐CNB) of masses in the breast, thyroid, head and neck, and other superficial sites. Between January 8, 2007 and June 28, 2007, 415 consecutive patients with 500 masses that were (1) nonpalpable (2) palpable but sonographically heterogeneous requiring ultrasound guidance to target the abnormal areas, or (3) palpable but located near a structure to be avoided underwent cytopathologist‐performed UG‐FNA and/or UG‐CNB. There were 395 (79%) nonpalpable masses and 105 (21%) palpable masses. The nondiagnostic rate was 1.4%. All cases undergoing both FNA and CNB were diagnostic. With continuing medical education in radiology and ultrasound‐guided procedures, training on phantoms, and practice on palpable masses before transition to nonpalpable masses, the author was able to successfully perform UG‐FNA/CNB of nonpalpable masses and targeted UG‐FNA/CNB of palpable masses. In the hands of the cytopathologist, ultrasound guidance offers a new tool to revitalize and redefine the role of the interventional cytopathologist. A new era in cytopathology and fine‐needle aspiration may be on the horizon. Diagn. Cytopathol. 2008;36:317–324. © 2008 Wiley‐Liss, Inc.
Fine‐needle aspiration cytology of Sister Mary Joseph's (paraumbilical) nodules
Authors: Handa Uma , Garg Sukant , Mohan Harsh
Published: April 2008

During a period of 5 years (2001–2005), six cases of Sister Mary Joseph's nodule (umbilical metastasis) were diagnosed by fine needle aspiration cytology (FNAC). In all the cases, FNAC of umbilical nodules was the first investigation and subsequently the patients were investigated for the primary tumor. The primary carcinoma was found in the stomach in three cases, ovary in two cases and one case was of non‐Hodgkin's lymphoma. Based on our findings, we suggest FNAC as an initial diagnostic procedure in cases suspected of umbilical metastasis. It is not only simple, fast, accurate and inexpensive but can also save the patient from other invasive diagnostic procedures. Diagn. Cytopathol. 2008;36:348–350. © 2008 Wiley‐Liss, Inc.
Pericardial effusion as primary manifestation of metastatic cutaneous adenoid cystic carcinoma: Diagnostic cytopathology from an exfoliative sample
Authors: Benchetritt Maxime , Butori Catherine , Long Elodie , Ilie Marius , Ferrari Emile , Hofman Paul
Published: April 2008

Adenoid cystic carcinoma (ACC) occurs not only as a tumor of salivary glands, but also in very unusual locations, such as in the skin. Only very few cases of primary cutaneous of ACC have metastasized to the lymph nodes and lungs. We present a 53‐year‐old man with metastasis of the pericardium from a primary cutaneous ACC (PCACC) of the scalp, which had been surgically treated 14 years ago. Exfoliative cytologic findings from pericardial effusion included small clusters of basaloid cells with occasional cystlike spaces containing mucoid material. To our knowledge, this is the first case of pericardial metastasis from a PCACC. Diagn. Cytopathol. 2008;36:351–354. © 2008 Wiley‐Liss, Inc.
Laminin terminates the Netrin/DCC mediated attraction of vagal sensory axons
Authors: Ratcliffe Elyanne M. , D'Autréaux Fabien , Gershon Michael D.
Published: April 2008

Vagal sensory axons navigate to specific sites in the bowel during fetal life. Netrin/deleted in colorectal cancer (DCC) were found to mediate the attraction of vagal sensory axons to the fetal mouse gut. We tested the hypothesis that laminin‐111 can reverse the chemoattractive effects of netrin and act as a stop signal for vagal sensory axons. Laminin‐111‐expressing cells were located in the E12 and E16 mouse bowel by in situ hybridization. At E12, these cells extended centrifugally from the endoderm; by E16, laminin‐111 expressing cells were found in the mucosa and outer gut mesenchyme. A similar pattern was seen in preparations of E13 and E15 mouse gut labeled with antibodies to laminin. Application of DiI to nodose ganglia identified vagal sensory axons growing into the fetal bowel. These terminals were found to avoid concentrations of laminin or to terminate at laminin‐delimited boundaries. Soluble laminin inhibited the preferential growth of nodose neurites toward netrin‐secreting cells (p < 0.01). This effect was mimicked by a peptide, YIGSR, a sequence within the β1 chain of laminin‐111 (p < 0.004) and antagonized by a peptide, IKVAV, a sequence within the α1 chain of laminin‐111. Antibodies to β1‐integrins were also able to reverse the inhibitive effects of laminin and restore the attraction of nodose neurites towards netrin‐1‐secreting cells. Soluble laminin inhibited the preferential growth of nodose neurites toward a cocultured explant of foregut. These findings suggest that laminin terminates the attraction of vagal sensory axons towards sources of netrin in the developing bowel. © 2008 Wiley Periodicals, Inc. Develop Neurobiol, 2008
An Iron(II) Spin‐Transition Compound with Thiol Anchoring Groups
Authors: Chandrasekar Rajadurai , Schramm Frank , Fuhr Olaf , Ruben Mario
Published: April 2008

The synthesis and characterisation of the complex [FeII(L)2](ClO4)2 [L = S‐(4‐{[2,6‐(Dipyrazol‐1‐yl)pyrid‐4‐yl]ethynyl}phenyl) ethanethioate] carrying both a spin‐transition core and acetyl‐protected terminal thiol groups is described. The compound exhibits a reversible, thermally driven solid‐state spin transition at 277 K with a hysteresis loop of ca. 8 K. The unique combination of the bistable spin‐transition property with thiol anchoring groups sets the basis for the investigation of the spin‐transition switching phenomenon at a single‐molecule level. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Protective effect of the cruciferous vegetable mustard leaf (Brassica campestris) against in vivo chromosomal damage and oxidative stress induced by γ‐radiation and genotoxic chemicals
Authors: Tiku Ashu B. , Abraham Suresh K. , Kale Raosaheb K.
Published: April 2008

We evaluated the possible protective effect of the popular Indian cruciferous vegetable mustard leaf (Brassica campestris) against chromosomal damage and oxidative stress induced by γ‐radiation, cyclophosphamide (CPH) and urethane (URE), in mice. In vivo bone marrow micronucleus test was performed to assess chromosomal damage, and oxidative stress was monitored by estimating the changes in lipid peroxidation and the status of glutathione (GSH) as well as redox cycle antioxidants. Pretreatment with 50–250 mg/kg body wt of mustard leaf extract (MLE) for seven days significantly reduced the frequencies of micronuclei induced by γ‐radiation, CPH and URE. The protective effect against chromosomal damage was associated with modulation of lipid peroxidation as well as an increase in GSH and the GSH‐dependent enzyme glutathione S‐transferase (GST). Mass spectral analysis showed the presence of glucosinolates in MLE used for the pretreatment of mice. These findings indicate that intake of the green leafy cruciferous vegetable mustard leaf can lead to protection against in vivo genotoxicity and oxidative stress. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Effects of model organophosphorous pesticides on DNA damage and proliferation of HepG2 cells
Authors: Hreljac Irena , Zajc Irena , Lah Tamara , Filipič Metka
Published: April 2008

Organophosphorous compounds (OPs) are commonly used pesticides. The primary mechanism of OP toxicity is the inhibition of acetylcholine esterase in the nervous system leading to a variety of acute and chronic effects. Recent studies have revealed several other targets of OPs that disturb noncholinergic biological systems. We investigated whether low concentrations of model OPs—methyl parathion (PT), methyl paraoxon (PO), and dimefox (DF)—induce DNA damage and/or affect cell proliferation in human hepatoma HepG2 cells. Genotoxicity of OPs was evaluated using the comet assay. The effect on cell proliferation was tested using the MTT assay and proliferation marker Ki‐67 immunocytochemistry. The effects of OPs on mRNA expression of the DNA damage responsivegenes p53, p21, GADD45α, and MDM2 were determined using qRT‐PCR. PT induced DNA damage at lower concentrations (1 μg/mL) than PO (100 μg/mL), whereas DF did not induce DNA damage. PT and PO caused a reduction of cell proliferation at their highest concentrations (100 μg/mL), while DF increased cell proliferation at all concentrations used (0.01–100 μg/mL). PT and PO upregulated expression of DNA damage responsive genes, while DF upregulated expression of p53, downregulated expression of p21, and had no effect on the expression of MDM2 and GADD45α. We conclude that PT and PO are genotoxic, while DF shows mitogenic activity. An important finding of this study is that PT had higher genotoxic potential than PO, which warrants for further investigations to correctly evaluate the hazards of exposure to these chemicals. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Assessment of DNA strand breaks induced by bleomycin in barley by the comet assay
Authors: Georgieva Mariyana , Stoilov Lubomir
Published: April 2008

Comet assay was applied to study induction and repair of DNA damage produced by bleomycin in barley genome. Experimental conditions were adapted to achieve efficient detection of both DNA single‐ and double‐strand breaks. Substantial increase of the parameter “% of DNA in tail” was observed coupled with almost linear dependence from bleomycin concentration, more pronounced for the induction of DNA double‐strand breaks. Data obtained at different recovery periods displayed rapid restoration of breakage, revealing that efficient mechanisms for repair of strand discontinuities induced by bleomycin are functional in barley DNA loop domains. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
The development of the Carboniferous Ben‐Zireg–Zousfana Trough in the northern part of the Béchar Basin, Western Algeria: implications for its structural evolution, sequence stratigraphy and palaeogeography
Authors: Malti Fatima Zohra , Benhamou Miloud , Mekahli Larbi , Benyoucef Madani
Published: April 2008

The sequence stratigraphical study of the Viséan Formations shows the importance of the Ben‐Zireg Trough for the structural development of the Béchar Basin. The sequence stratigraphical approach has allowed to decipher the systems tracts, which have filled the accommodation space of the Ben‐Zireg Trough under tectono‐eustatic control. A deep sea fan recorded by the first flysch‐type deposits transported by submarine canyons was followed by a prograding lowstand wedge recorded in the flysch with olistostromes, a transgressive system tract (TST) identified by flysch‐type deposits without olistostrome, and a highstand system tract (HST) represented by the patch reef and flyschoid deposits. The biostromal barrier and platform limestones indicate also a TST and sometimes a shelf margin wedge (SMW). Thus, these stratal patterns have been identified as Types 1 and 2 genetic sequences of third‐order eustatic cycles and are based on correlations of cross‐sections located around the Ben‐Zireg Anticline.

During the Tournaisian, the Ben‐Zireg Anticline, the Djebel Ioucha, the ‘Grand Erg Occidental’ and the Erfoud areas were uplifted to form palaeohighs, whereas the Zousfana and Saoura Valley areas were situated in a trough position. There were also created sub‐basins north of Ben‐Zireg; from Grouz (Teniet El Haïdoura) to Soltane El Betoum, and southeast of the Meharez High.

During the Early Viséan, an inversion of the Ben‐Zireg High occurred, resulting in a widening and deepening of the Ben‐Zireg–Zousfana Trough. In the Upper Viséan formations, peri‐reefal limestone beds appear in the current position of the Djebel Béchar. Further west in the Chebket–Mennouna–Djihani area occur small patch reefs. On the eastern edge, the bioherm formations were described previously as ‘Waulsortian‐like reefs’ of the ‘Grand Erg Occidental’. These facies recorded the TST. Thus, a carbonate platform became established at the expense of the Ben‐Zireg–Zousfana Trough. Copyright © 2008 John Wiley & Sons, Ltd.
Can the afterbirth play a role after birth?
Authors: Dötsch Jörg , Schild Ralf L. , Struwe Ellen
Published: April 2008

Before the introduction of modern medicine, the afterbirth (placenta) has been believed to host many secrets and even parts of the newborn baby's soul. Placenta and fetus are closely linked in the so‐called feto‐placental unit. Therefore, the placenta contains information on intrauterine fetal life. This information can not be obtained from the baby since tissue can not be examined biologically without injury. We are currently conducting a multicenter study to predict the probability of later disease inflicted by an adverse intrauterine environment. An early prediction of risk of future diseases would help to initiate early preventive measures.
Lack of cross‐tolerance following heat and cadmium exposure in functional MDCK monolayers
Authors: Dokladny Karol , Wharton Walker , Ma Thomas Y. , Moseley Pope L.
Published: April 2008

Exposure of monolayers of Madin–Darby canine kidney epithelial (MDCK) cells to a mild heat stimulus induces a state of physiological thermotolerance in which epithelial barrier function is maintained following a second more severe heat stress. We have previously shown that expression of exogenous HSP70 fully mimics the effects of the conditioning heat stress. Exposure of MDCK cells to elevated temperatures or medium containing CdCl2 caused a robust increase in cellular levels of HSP70. Pretreatment of MDCK monolayers with cadmium but not heat caused a small protection of epithelial barrier function against a second challenge with cadmium. In addition, a prior exposure of monolayers to cadmium at levels sufficient to induce HSP70 expression and increased cellular chaperone activity did not afford protection against a subsequent thermal challenge. Therefore multiple stress‐specific cellular pathways impinge on the ability of heat shock proteins to induce physiological thermotolerance. Occludin, a component of tight junctions, is induced in MDCK cells engineered to express high levels of exogenous HSP70, potentially accounting for an elevation in baseline resistance. However neither basal levels of occludin, nor alterations in occludin expression, were correlated with epithelial barrier function in MDCK cells either exposed to elevated temperatures or challenged with cadmium. Copyright © 2008 John Wiley & Sons, Ltd.
Aluminum‐mediated metabolic changes in rat serum and urine: A proton nuclear magnetic resonance study
Authors: Tripathi Sandeep , Somashekar B. S , Mahdi Abbas Ali , Gupta Ashish , Mahdi Farzana , Hasan Mahdi , Roy Raja , Khetrapal C. L.
Published: April 2008

The toxic effects of Al3+ have been studied in 90‐days AlCl3 orally treated male albino rats (n = 7) using 1H NMR spectroscopy‐based metabolic profile of rat serum and urine, serum enzyme tests, behavioral impairment, and histopathology of kidney and liver. Metabolic profile of 90‐days Al3+‐treated rat sera showed significantly elevated levels of alanine, glutamine, β‐hydroxy‐butyrate, and acetoacetate and significantly decreased level of acetone when compared with that of control rats. However, metabolic profile of 90‐days Al3+‐treated rat urine showed significantly decreased levels of citrate, creatinine, allantoin, trans‐aconitate, and succinate and significantly increased level of acetate when compared to control rats. The overall perturbations observed in the metabolic profile of serum and urine demonstrate the impairment in the tricarboxylic acid cycle, liver and kidney metabolism, which was further reinstated by clinical chemistry and histopathological observations. Moreover, “in vivo” behavioral impairment has also been observed as the indication of aluminum neurotoxicity. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:119–127, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20219
Sphingosine can pre‐ and post‐condition heart and utilizes a different mechanism from sphingosine 1‐phosphate
Authors: Vessey Donald A. , Li Luyi , Kelley Michael , Zhang Jianqing , Karliner Joel S
Published: April 2008

Consistent with previous reports, sphingosine at a high concentration (5 μM) was cardiotoxic as evidenced by increased infarct size in response to ischemia/reperfusion in an ex vivo rat heart. Sphingosine 1‐phosphate (S1P) at 5 μM was cardioprotective. However, at a physiologic concentration (0.4 μM) sphingosine as well as S1P was effective in protecting the heart from ischemia/reperfusion injury both when perfused prior to 40 min of ischemia (preconditioning) or when added to reperfusion media following ischemia (postconditioning). Protection by sphingosine and S1P was evidenced with both pre‐ and post‐conditioning by a >75% recovery of left ventricular developed pressure during reperfusion and a decrease in infarct size from 45% of the risk area to less than 8%. When VPC23019, an S1P1and3G‐protein coupled receptor antagonist, was added to the preconditioning or postconditioning medium along with S1P, it completely blocked S1P‐induced protection. However, VPC 23019 did not affect the ability of 0.4 μM sphingosine to either precondition or postcondition hearts. Studies of preconditioning revealed that inhibition of protein kinase C with GF109203X blocked preconditioning by S1P. However, GF109203X did not affect preconditioning by 0.4 μM sphingosine. Likewise, cotreatment with the PI3 kinase inhibitor wortmanin blocked preconditioning by S1P but not by sphingosine. By contrast, inhibition of protein kinase G with KT5823 had no effect on S1P preconditioning but completely eliminated preconditioning by sphingosine. Also, the protein kinase A inhibitory peptide 14–22 amide blocked preconditioning by sphingosine but not S1P. These data reveal for the first time that sphingosine is not toxic at physiologic concentrations but rather is a potent cardioprotectant that utilizes a completely different mechanism than S1P; one that is independent of G‐protein coupled receptors and utilizes cyclic nucleotide‐dependent pathways. © 2008 Wiley Periodicals, Inc. J Biochem Mol Toxicol 22:113–118, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20227
AKT as locus of fragility in robust cancer system
Authors: Radisavljevic Ziv
Published: April 2008

Metastatic cancer is a complex positive feedback loop system. Such as system has a tendency to acquire extreme robustness. Signaling pathways controlling that robustness can fail completely if an essential element from the signaling is removed. That element is a locus of fragility. Targeting that locus represents the best way to target the cancer robustness. This prospect presents another locus of fragility in signaling complex system network, controlling the cell cycle progression through the PI3K/AKT/mTOR/RAN pathway and cell migration and angiogenesis through the VEGF/PI3K/AKT/NO/ICAM‐1 pathway. The locus of fragility of these pathways is AKT, which is regulated by a balance of catalase/H2O2 or by AKT inhibitor. Tiny and trivial perturbations such as change in redox state in the cells by antioxidant enzyme catalase, scavenging H2O2 signaling molecule, regulates robust signaling molecule AKT, abolishing its phosporilation and inducing cascading failure of robust signaling pathways for cell growth, proliferation, migration, and angiogenesis. An anticancer effect of the antioxidant is achieved through the AKT locus, by abolishing signals from growth factors VEGF, HGF, HIF‐1α and H2O2. Previously reported locus of fragility nitric oxide (NO) and locus AKT are close in the complex signaling interactome network, but they regulate distinct signaling modules. Simultaneously targeted loci represents new principles in cancer robustness chemotherapy by blocking cell proliferation, migration, angiogenesis and inducing rather slow then fast apoptosis leading to slow eradication of cancer. J. Cell. Biochem. 104: 2071–2077, 2008. © 2008 Wiley‐Liss, Inc.
Quantitative binomial distribution analyses of nanoscale like‐solute atom clustering and segregation in atom probe tomography data
Authors: Moody Michael P. , Stephenson Leigh T. , Ceguerra Anna V. , Ringer Simon P.
Published: April 2008

The applicability of the binomial frequency distribution is outlined for the analysis of the evolution nanoscale atomic clustering of dilute solute in an alloy subject to thermal ageing in 3D atom probe data. The conventional χ2 statistics and significance testing are demonstrated to be inappropriate for comparison of quantity of solute segregation present in two or more different sized system. Pearson coefficient, μ, is shown to normalize χ2 with respect to sample size over an order of magnitude. A simple computer simulation is implemented to investigate the binomial analysis and infer meaning in the measured value of μ over a series of systems at different solute concentrations and degree of clustering. The simulations replicate the form of experimental data and demonstrate the effect of detector efficiency to significantly underestimate the measured segregation. The binomial analysis is applied to experimental atom probe data sets and complementary simulations are used to interpret the results. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
Adaptations in trabecular bone microarchitecture in Olympic athletes determined by 7T MRI
Authors: Chang Gregory , Pakin S. Kubilay , Schweitzer Mark E. , Saha Punam K. , Regatte Ravinder R.
Published: April 2008

Purpose

To produce in vivo high‐resolution images of the knee and to determine the feasibility of using 7T MR to detect changes in trabecular bone microarchitecture in elite athletes (Olympic fencers) who undergo high impact activity.

Materials and Methods

The dominant knees of four males from the U.S. Olympic Fencing Team and three matched healthy male controls were scanned in a 7T whole‐body scanner using a quadrature knee coil with three‐dimensional (3D) fast low angle shot (FLASH): 50 axial images at the distal femur (0.156 mm × 0.156 mm) and 80 axial images at the knee joint (0.195 mm × 0.195 mm). Bone volume fraction (BVF) and marrow volume fraction (MVF) images were computed and fuzzy distance transform (FDT) and digital topological analysis (DTA) were applied to determine: trabecular number (Tb.N), trabecular thickness (Tb.Th), and trabecular separation (Tb.Sp); BVF (BV/TV); trabecular and marrow space surface‐to‐curve ratio (SC, marker of plate to rod ratio); and trabecular and marrow space erosion index (EI, inverse marker for network connectivity). Quadriceps muscle volume (MV) was calculated as well. We calculated group means and performed two‐tailed t‐tests to determine statistical significance.

Results

Compared to controls, fencers had: decreased Tb.Sp (P = 0.0082 at femur, P = 0.051 at joint); increased Tb.N (P < 0.05 at both femur and joint) and BV/TV (P < 0.001 at both femur and joint); increased trabecular SC and decreased marrow space SC (P < 0.01 at both femur and joint); decreased trabecular EI and increased marrow space EI (P < 0.01 at both femur and joint); and increased MV (P = 0.038). There was no difference in Tb.Th at the distal femur (P = 0.92) or joint (P = 0.71) between groups.

Conclusion

To our knowledge, this is the first study to perform 7T MRI of the knee in vivo. Elite athletes who undergo high impact activity have increased MV and improved trabecular bone structure compared to controls. J. Magn. Reson. Imaging 2008;27:1089–1095. © 2008 Wiley‐Liss, Inc.
Magnetization transfer based contrast for imaging denatured collagen
Authors: Harel Amir , Eliav Uzi , Akselrod Solange , Navon Gil
Published: April 2008

Purpose

To study of the sensitivity of various NMR and MRI methods and parameters to the degree of thermal denaturation of collagen.

Materials and Methods

Collagen type I powder was washed with methanol:chloroform to remove traces of lipids and then suspended in saline. Denaturation was carried out by heating the suspension for 5–120 minutes at a temperature range of 50–100°C. The NMR methods tested were two T2 filter methods: Goldman‐Shen (GS) and Edzes‐Samulski (ES); magnetization transfer contrast (MTC); double quantum filtering (DQF) and high resolution spectroscopy. MRI contrasts based on these methods were compared.

Results

The following parameters were found to be sensitive to denaturation of collagen: 1) the amount of spins that experience high dipolar interactions as assessed by DQF; 2) MTR; 3) kwT1w (where kw is the magnetization transfer rate from water to collagen, and T1w is the water protons longitudinal relaxation time); and 4) aliphatic residues content. The contrast between native and denatured collagen was improved by all the tested methods, with ES and DQF producing the highest contrast.

Conclusion

Methods depending on T2 filtering and DQF were found to be sensitive to the degree of thermal denaturation of collagen and improve the contrast between native and denatured collagen. J. Magn. Reson. Imaging 2008;27:1155–1163. © 2008 Wiley‐Liss, Inc.
Correction for heart rate variability during 3D whole heart MR coronary angiography
Authors: Roes Stijntje D. , Korosoglou Grigorios , Schär Michael , Westenberg Jos J. , van Osch Matthias J.P. , de Roos Albert , Stuber Matthias
Published: April 2008

Purpose

To evaluate the effect of a real‐time adaptive trigger delay on image quality to correct for heart rate variability in 3D whole‐heart coronary MR angiography (MRA).

Materials and Methods

Twelve healthy adults underwent 3D whole‐heart coronary MRA with and without the use of an adaptive trigger delay. The moment of minimal coronary artery motion was visually determined on a high temporal resolution MRI. Throughout the scan performed without adaptive trigger delay, trigger delay was kept constant, whereas during the scan performed with adaptive trigger delay, trigger delay was continuously updated after each RR‐interval using physiological modeling. Signal‐to‐noise, contrast‐to‐noise, vessel length, vessel sharpness, and subjective image quality were compared in a blinded manner.

Results

Vessel sharpness improved significantly for the middle segment of the right coronary artery (RCA) with the use of the adaptive trigger delay (52.3 ± 7.1% versus 48.9 ± 7.9%, P = 0.026). Subjective image quality was significantly better in the middle segments of the RCA and left anterior descending artery (LAD) when the scan was performed with adaptive trigger delay compared to constant trigger delay.

Conclusion

Our results demonstrate that the use of an adaptive trigger delay to correct for heart rate variability improves image quality mainly in the middle segments of the RCA and LAD. J. Magn. Reson. Imaging 2008;27:1046–1053. © 2008 Wiley‐Liss, Inc.
Vibrational transitions in Rydberg matter clusters from stimulated Raman and Rabi‐flopping phase delay in the infrared
Authors: Holmlid Leif
Published: April 2008

Recently, rotational spectra of giant Rydberg matter (RM) clusters were studied in the radio frequency range (Mol. Phys. 105 (2007) 933–939), giving high‐precision bond distances in the nanometer range. However, the theoretical and experimental problem of vibrational motion or, rather, coupled electronic‐vibrational motion in the RM clusters is still unsolved; but it is expected that broad phonon bands will exist. Spectroscopic signatures from space make it likely that RM is a common form of matter in the Universe, and phonon bands in this spectroscopic range have not been taken into account so far. Spectroscopic results are now reported on transitions in the range 0.01–20 cm−1, using primarily infrared (IR) lasers to probe the RM in a tunable open cavity with a Fabry–Perot interferometer to aid in the identification of the shifts. Stimulated Raman scattering from electronic transitions and Rabi‐flopping from electronic states in the clusters are observed. The broad stimulated Raman peaks are assigned to one and two consecutive vibrational (electronic‐vibrational) transitions. Theoretical values predicted for vibrations (phonon maxima) and electronic processes are in reasonable agreement with the experimental results. Improved calculations are needed to verify the assignments of the vibrational phonon distributions. Copyright © 2008 John Wiley & Sons, Ltd.
Bridging boundaries: Meeting the challenge of workplace diversity
Authors: Ernst Christopher , Yip Jeffrey
Published: April 2008

In today's globally diverse and increasingly interconnected world, social identity boundaries rub together, pull apart, and collide in the workplace. When identity divides open up, people look to leaders to bridge the gaps. By employing four tactics—suspending, reframing, nesting, and weaving—leaders can facilitate positive cross‐boundary interactions.
Novel Types of Carborane‐Carrier Hyaluronan Derivatives via “Click Chemistry”
Authors: Di Meo Chiara , Panza Luigi , Campo Federica , Capitani Donatella , Mannina Luisa , Banzato Alessandra , Rondina Maria , Rosato Antonio , Crescenzi Vittorio
Published: April 2008

Two new HA derivatives bearing carborane rings were synthesized by click chemistry. The optimal conditions were assessed for the preparation of biocompatible boron carriers, potentially suitable for application in BNCT and capable of targeting the CD44 antigen. The new polymeric samples were characterized by means of NMR‐spectroscopy techniques that gave degrees of 17 and 8% for HAAACB and HapACB, respectively. Both HAAACB and HApACB turned out to be nontoxic for colorectal, ovarian and bladder tumor cell lines, to disclose a specific interaction with the CD44 antigen as the native hyaluronan moiety, and to deliver boron‐atom concentrations largely sufficient for BNCT therapy when accumulated in cancer cells.

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Poly(esterimide) Wire Enamels: Coatings with the Right Combination of Thermal and Mechanical Properties for Many Applications
Authors: Biondi Giovanna
Published: April 2008

Electrical insulating enamels are usually made of thermosetting resins diluted in suitable solvents, which can be enameled on magnetic wires. PEI‐based enamel is one of the most important insulating enamels in electrical engineering. The characteristics of various PEI based wires are quite different depending on the final use. Using special additives, it is possible to produce optimized PEI versions with improved characteristics. Special applications are possible by introducing pigments or conductive materials in the formulation. Thermoplastic PEI are also obtainable. This review gives an overview of the fascinating world of PEI, from discovery up to the latest developments.

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Synthesis and Performance of PP Microfiltration Membranes Grafted with Polymer Layers of Different Structure
Authors: Yang Hu , Ulbricht Mathias
Published: April 2008

Reproducible and controllable hydrophilic layers were grafted on macroporous PP membranes by surface initiated grafting. Two methods were adopted, i.e., through adsorption of or entrapping the photo‐initiator on the membrane surface. The latter method yielded longer grafted chains under otherwise identical conditions. Depending on monomer solution composition, brush layers or network‐like structures were grafted onto the entire membrane surface without significant loss of water flux. The influence of the structure of grafted layers on water permeation, protein adsorption, and protein microfiltration fluxes was investigated. It was found that membranes grafted with network‐like structures have the best performance.

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Melt Elongation of Polymer Nanocomposites: A Method for the Controlled Production of Dichroic Films
Authors: Schmid Daniel , Handge Ulrich A. , Gann John P. , Yan Mingdi , Caseri Walter
Published: April 2008

A processing method based on stretching of molten polymer nanocomposites was applied to prepare dichroic films. First, dodecanethiol‐capped gold particles were embedded in low density polyethylene. The resulting isotropic films were stretched in the melt under uniaxial loading using an elongational rheometer. The melt elongation technique resulted in reproducible characteristics of the optical properties and can be directly transferred to an industrial scale. The organic coating of the metal particles plays an important role in the generation of the dichroism. A reactive surface (adsorbed perfluorophenyl azide) led to strongly agglomerated particles which obviously did not lead to dichroic films.

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UV‐Cured Interpenetrating Acrylic‐Epoxy Polymer Networks: Preparation and Characterization
Authors: Sangermano Marco , Carbonaro William , Malucelli Giulio , Priola Aldo
Published: April 2008

Acrylic‐epoxy interpenetrating polymer networks were prepared by means of UV curing. The photopolymerization process was investigated via real‐time FTIR spectroscopy. The hybrid, cured films showed a broad tan δ peak in DMTA demonstrating the high damping properties of the hybrid, cured formulations. A decrease on shrinkage was achieved by increasing the epoxy‐resin content in the photocurable formulation, with a consequent increase in adhesion properties.

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The Silane‐ene and Silane‐Acrylate Polymerization Process: A New Promising Chemistry?
Authors: El‐Roz Mohamad , Lalevée Jacques , Allonas Xavier , Fouassier Jean‐Pierre
Published: April 2008

The combination of silanes and enes yields highly reactive photopolymerizable mixtures that exhibit very low oxygen sensitivity. Diphenylsilane (SiH) has been used in combination with different multifunctional acrylates (AC) and conversions of 100% and about 25% for AC and SiH, respectively, have been reached. Final tack free polymers are obtained as a consequence of the fact that the polymerization rates are not affected by oxygen. When using vinylacetate (VA), divinylether (DVE), and allylether (AE) units, the final silane conversion still remains low (50, 20, and 20%, respectively) but are promising. The reactivity of the silyl radicals is investigated by laser flash photolysis. The role of the bond dissociation energy of the silane is outlined.

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