bluuebunny/crossref_metadata_2025_split huggingface dataset:
Improving the efficiency of imprinting in poly(HEMA) for polyaromatic hydrocarbon using silver ions
Authors: Sreenivasan K. 
Published: May 2008

AbstractMolecularly imprinted polymer for a typical polyaromatic hydrocarbon, naphthalene, was synthesized. Silver ions are incorporated during the synthesis and the equilibrium uptake of the template molecule (naphthalene) by the imprinted polymer was found to be many folds higher than the uptake of the molecule by the imprinted polymer prepared in the absence of the metal ions. The enhanced adsorption was attributed due to the improved interaction between the template molecules and the monomers which is reasoned to be induced by the silver ions. It appears that the adsorption capacity of molecules without having any functional groups could be increased by the methodology reported here. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Mechanism of Fibroblast‐Like Synoviocyte Apoptosis Induced by Recombinant Human Endostatin in Rats with Adjuvant Arthritis
Authors: Huang Xue‐Ying , Chen Fei‐Hu , Li Jun , Xia Li‐Juan , Liu Yong‐Jing , Zhang Xiao‐Ming , Yuan Feng‐Lai 
Published: May 2008

AbstractRheumatoid arthritis (RA) is a chronic inflammatory disease characterized by pronounced synovial hyperplasia, in which there may be an imbalance between the growth and death of fibroblast‐like synoviocytes (FLS). The present study was undertaken to examine the effect of recombinant human endostatin (rhEndostatin) on FLS apoptosis in experimental RA. Adjuvant arthritis (AA) was induced in male Sprague Dawley (SD) rats. Using cultured AA FLS obtained from these rats, the apoptosis process was measured by terminal deoxyribonucleotidyl transferase‐mediated dUTP nick‐end labeling (TUNEL) as well as Annexin V‐fluorescein isothiocyanate (FITC) and propidium iodide (PI) labeling methods. In addition, the expression levels of the Fas, c‐jun, NFκB, and caspase‐3 gene products in synovial tissues were quantified by quantitative real‐time polymerase chain reaction (qPCR) and/or Western blotting assays. Our data revealed that rhEndostatin induced apoptosis in AA FLS. The number and signal density of TUNEL‐positive cells were significantly increased in rats treated with rhEndostatin (2.5 mg/kg). The percentage of Annexin V‐FITC‐positive cells was 6.67% after treatment with rhEndostatin at 25 μg/mL for 48 hr, compared with only 3.32% among untreated control cells. There were significant increases in Fas mRNA, c‐jun mRNA, c‐Jun protein, and caspase‐3 (p20) protein in AA synovial tissues treated with rhEndostatin (2.5 mg/kg), whereas no significant difference in NFκB expression was detected between treated and untreated tissues. These findings indicate that rhEndostatin has a therapeutic effect on RA by inducing FLS apoptosis, which is strongly associated with increased expression of Fas, c‐jun, and caspase‐3, but not NFκB. Anat Rec, 291:1029–1037, 2008. © 2008 Wiley‐Liss, Inc.
Annual Morphological Cycles of Testis and Thumb Pad of the Male Frog (Rana ridibunda)
Authors: Kaptan Engin , Murathanoğlu Osman 
Published: May 2008

AbstractIn this study, Rana ridibunda was used as samples because of their wide use in Turkey. Male frogs were collected in the East Marmara region each month throughout 1 year. Frogs from every monthly collection were used to analyze structural components of the thumb pads and testes. Spermatogenetic activity of Rana ridibunda living in the East Marmara region was determined to be “potentially continuous” type. Generally, the increase in the number and the size of nuclei of Leydig cells was inversely proportional to the fluctuation of spermatogenetic activity. The lumen of the seminiferous tubules in testes contained, in addition to the spermatogenic cells, a Periodic‐acid Schiff‐positive granular material. The amount of this material varied throughout the year, and that finding suggested a function related to spermiation. The components of thumb pads exhibited structural changes with respect to the activities of Leydig cells. During the periods where the Leydig cells were active, mucus glands (also called breeding glands) of thumb pads were also developed. On the other hand, we observed mixed glands with unknown function, which as first reported by us, and were poison glands in the thumb pads. The results suggest structural changes in the thumb pads are linked to changes in the testes. Anat Rec, 291:1106‐1114, 2008. © 2008 Wiley‐Liss, Inc.
Polymorphs and Polymorphic Cocrystals of Temozolomide
Authors: Babu N. Jagadeesh , Reddy L. Sreenivas , Aitipamula Srinivasulu , Nangia Ashwini 
Published: June 2008

AbstractCrystal polymorphism in the antitumor drug temozolomide (TMZ), cocrystals of TMZ with 4,4′‐bipyridine‐N,N′‐dioxide (BPNO), and solid‐state stability were studied. Apart from a known X‐ray crystal structure of TMZ (form 1), two new crystalline modifications, forms 2 and 3, were obtained during attempted cocrystallization with carbamazepine and 3‐hydroxypyridine‐N‐oxide. Conformers A and B of the drug molecule are stabilized by intramolecular amide NH⋅⋅⋅Nimidazole and NH⋅⋅⋅Ntetrazine interactions. The stable conformer A is present in forms 1 and 2, whereas both conformers crystallized in form 3. Preparation of polymorphic cocrystals I and II (TMZ⋅BPNO 1:0.5 and 2:1) were optimized by using solution crystallization and grinding methods. The metastable nature of polymorph 2 and cocrystal II is ascribed to unused hydrogen‐bond donors/acceptors in the crystal structure. The intramolecularly bonded amide N–H donor in the less stable structure makes additional intermolecular bonds with the tetrazine CO group and the imidazole N atom in stable polymorph 1 and cocrystal I, respectively. All available hydrogen‐bond donors and acceptors are used to make intermolecular hydrogen bonds in the stable crystalline form. Synthon polymorphism and crystal stability are discussed in terms of hydrogen‐bond reorganization.
Family‐based association testing of OCD‐associated SNPs of SLC1A1 in an autism sample
Authors: Brune Camille W. , Kim Soo‐Jeong , Hanna Gregory L. , Courchesne Eric , Lord Catherine , Leventhal Bennett L. , Cook Edwin H. 
Published: May 2008

AbstractReports identified the neuronal glutamate transporter gene, SLC1A1 (OMIM 133550, chromosome 9p24), as a positional and functional candidate gene for obsessive–compulsive disorder (OCD). The presence of obsessions and compulsions similar to OCD in autism, the identification of this region in a genome‐wide linkage analysis of individuals with autism spectrum disorders (ASDs), and the hypothesized role of glutamate in ASDs make SLC1A1 a candidate gene for ASD as well. To test for association between SLC1A1 and autism, we typed three single nucleotide polymorphisms (SNPs, rs301430, rs301979, rs301434) previously associated with OCD in 86 strictly defined trios with autism. Family‐Based Association Tests (FBAT) with additive and recessive models were used to check for association. Additionally, an rs301430–rs301979 haplotype identified for OCD was investigated. FBAT revealed nominally significant association between autism and one SNP under a recessive model. The G allele of rs301979 was undertransmitted (equivalent to overtransmission of the C allele under a dominant model) to individuals with autism (Z=−2.47, P=0.01). The G allele was also undertransmitted in the T–G haplotype under the recessive model (Z=−2.41, P=0.02). Both findings were also observed in the male‐only sample. However, they did not withstand correction for multiple comparisons.
Music and Physics: A Cultural, Interdisciplinary History
Authors: Jackson Myles W. 
Published: June 2008

AbstractMusik und Physik: Eine kulturelle, interdisziplinäre Geschichte. Dieser Aufsatz untersucht den Austausch zwischen Physikern, Musikern, und Instrumentenmachern in Deutschland im 19. Jahrhundert. Er repräsentiert eine materielle Kulturgeschichte, die gleichzeitig eine interdisziplinäre Analyse darstellt. Vier konkrete Beispiele solchen Austausches werden diskutiert: das Verhältnis zwischen musikalischen Automaten und Virtuosi, die Zungenpfeife als ein musikalisches und wissenschaftliches Instrument, die Geschichte der Standardisierung des Kammertons, und die Versuche, musikalische Virtuosität zu bemessen. Dieser Aufsatz zeigt, wie Kulturgeschichten erstens den naturwissenschaftlichen Inhalt ernst nehmen können und sollen, und zweitens, wie solche Geschichten disziplinäre Geschichten verbessern können.
Colour change of chemiluminescence for base‐induced decomposition of dioxetane bearing a 4‐(4‐cyanophenyl)iminomethyl‐3‐hydroxyphenyl group
Authors: Watanabe Nobuko , Suga Naoki , Matsumoto Masakatsu 
Published: May 2008

AbstractA bicyclic dioxetane 1 bearing a 4‐(4‐cyanophenyl)iminomethyl‐3‐hydroxyphenyl group was found to undergo base‐induced decomposition with the accompanying emission of light, the colour of which changed depending on the base used and its concentration. When 1 was triggered with tetrabutylammonium fluoride (TBAF), 1 displayed an emission of glowing orange light. On the other hand, on treatment with a high concentration of potassium t‐butoxide complexed with 18‐crown‐6 ether, 1 afforded a flash of blue light. The mechanistic study of this unprecedented phenomenon revealed that the emission of glowing orange light was due to the normal oxido anion of keto ester 11, whereas the emission of a flash of blue light was attributed to another species that was produced by addition of a nucleophile to an iminomethyl of unstable oxido anion of dioxetane 10. Copyright © 2008 John Wiley & Sons, Ltd.
Structural implications of mitochondrial dynamics
Authors: Bereiter‐Hahn Jürgen , Vöth Monika , Mai Sören , Jendrach Marina 
Published: June 2008

AbstractMitochondrial components are continuously distributed throughout the whole chondriome of a cell by fusion and fission. Thus, a single mitochondrion represents a transient fraction of the chondriome. Mitochondrial dynamics are responsible for intracellular distribution and reaction of mitochondria to functional requirements. Dynamics occur on different levels: overall morphology, inner membrane–matrix compartment, turnover and rearrangements of mitochondrial proteins and DNA. Electron micrographs of serial sections of human umbilical vein endothelial cells reveal perinuclear mitochondria of extreme length and with branches in those cells that also have short peripheral mitochondria. Interactions of mitochondria with cytoskeletal elements are revealed in cells treated with cytochalasin D to destroy actin fibrillar structures or after disassembling microtubule by nocodazole. In the latter case mitochondria not only become immobilized, they also acquire a multiple ring structure. In F‐actin‐disturbed cells, motility (shape changes in particular) is increased and the mitochondria become elongated. Mechanisms of how F‐actin might render mitochondria immobile may involve dynamin‐related protein 1 (DRP1) or interaction with anion channels. This may be responsible for the lack of mitochondrial motility in senescent cells. Fusion between mitochondria revealed local fluctuations of mitochondrial red fluorescent protein (mtRFP), indicating novel fast inner membrane reorganizations. Mitochondrial dynamics result from a complex interplay between the molecular organization of the inner membrane–matrix complex and cytoskeletal elements outside.
Solvent interactions with the Trp‐cage peptide in 35% ethanol–water
Authors: Neuman Robert C. , Gerig John T. 
Published: May 2008

AbstractIntermolecular NOE experiments have been used to explore interactions of water and ethanol molecules in 35% ethanol/65% water (v/v) with the peptide Trp‐cage at temperatures from 5 to 25°C. Magnetic dipole–dipole cross‐relaxation terms σ and σ for interaction of solvent components with spins of the peptide suggest that ethanol molecules associate with backbone atoms for times of the order of nanoseconds at 5°C. Formation of peptide–ethanol complexes can also account for the larger‐than‐expected values of cross‐relaxation terms at higher temperatures. Hydrocarbon side chains of the peptide do not appear to experience such interactions with ethanol. Cross relaxation resulting from water–peptide interactions are consistent with long‐lived water interactions with the backbone atoms. Water cross relaxation with nonpolar side chains of the peptide (Leu2, Ile4, Leu7, and proline residues) are only those expected for bulk solvent. However, long‐lived association of both water and ethanol with the polar side chains of Tyr3 and Trp6 is indicated by the data. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 862–872, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Self‐assembling peptides: Sequence, secondary structure in solution and film formation
Authors: Gambaretto Roberta , Tonin Lorenzo , Di Bello Carlo , Dettin Monica 
Published: June 2008

AbstractPeptides of alternating charge and hydrophobic amino acids have a tendency to adopt unusually stable β‐sheet structures that can form insoluble macroscopic aggregates under physiological conditions. In this study, analogues of a well‐known self‐assembling peptide, characterized by the same polar/nonpolar periodicity but with different residues, were designed to study the relationship between sequence, conformation in solution and film‐forming capacity in saline solution. Peptide conformation, evaluated by circular dichroism, correlated with film forming capacity observed by inverted optical microscopy after addition of saline solution and subsequent drying. We found that polar/nonpolar periodicity of several analogues is not criterion enough to induce β‐sheet and thus film formation and that conformations different from β‐sheet also allow self‐assemblage. Furthermore, addition of the short adhesive sequence RGD to a known self‐assembling sequence was shown to not prevent the self‐assembling process. This finding might prove useful for the design of biomimetic scaffolds. © 2008 Wiley Periodicals, Inc. Biopolymers 89: 906–915, 2008.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Application of high‐speed counter‐current chromatography for the isolation of antiviral eremophilenolides from Ligularia atroviolacea
Authors: Shi Shu‐Yun , Zhou Hong‐Hao , Huang Ke‐Long , Li Hai‐Bo , Liu Su‐Qin , Zhao Yu 
Published: June 2008

AbstractLigularia is mainly distributed in the western regions of China. Most of the species have been traditionally used in folk medicine for the treatment of hepatitis B, asthma, hemoptysis and pulmonary tuberculosis. In our continuation of research on antiviral components from traditional Chinese medicine, Ligularia atroviolacea was tested for inhibitory effects on hepatitis B virus (HBV). A bioassay‐guided phytochemical examination of L. atroviolacea disclosed that its ethyl acetate extract, which was made up of two eremophilenolides, showed suppressive activity on the expression of HBV surface antigen (HBsAg) in the HepG2.2.15 cell line. Then a simple and effective preparative high‐speed counter‐current chromatography method was successfully developed for the isolation and purification of two main active metabolites, 8β‐hydroxyeremophil‐3,7(11)‐dien‐12,8α;15,6α‐diolide and 8β‐methoxyeremophil‐3,7(11)‐dien‐12,8α;15,6α‐diolide from the ethyl acetate extract of L. atroviolacea by a one‐step separation using a two‐phase solvent system composed of light petroleum (60–90°C)–ethyl acetate–methanol–water (9:1:8:2, v/v/v). The chemical structures of the two eremophilenolides were identified by ESI‐MS, 1H‐NMR and 13C‐NMR analysis. The anti‐HBV activity of the two purified compounds was measured; both of them showed suppressive activity on the expression of HBsAg in the HepG2.2.15 cell line. The results support the continued and expanded exploitation and utilization of L. atroviolacea. Copyright © 2008 John Wiley & Sons, Ltd.
A sensitive method for determination of salvianolic acid A in rat plasma using liquid chromatography/tandem mass spectrometry
Authors: Pei Lixia , Bao Yuanwu , Wang Haidi , Yang Fan , Xu Bei , Wang Shoubao , Yang Xiuying , Du Guanhua 
Published: May 2008

AbstractSalvianolic acid A (SAA), a major effective constituent of Salvia miltiorrhizas, is widely used in traditional Chinese medicine. A sensitive rapid analytical method was established and validated for SAA in rat plasma, which was further applied to assess the pharmacokinetics of SAA in rats receiving a single oral dose of SAA. The method used liquid chromatography tandem mass spectrometry in multiple reaction monitoring mode with chloramphenicol as the internal standard. A simple liquid–liquid extraction based on ethyl acetate was employed. The combination of a simple sample cleanup and short chromatographic run time (3 min) increased the throughput of the method substantially. The method was validated over the range 1.4–1000 ng/mL with a correlation coefficient >0.99. The lower limit of quantification was 1.4 ng/mL for SAA in plasma. Intra‐ and inter‐day accuracies for SAA were 95–113 and 98–107%, and the inter‐day precision was less than 12%. This method is more sensitive and faster than previous methods. After a single oral dose of 100 mg/kg of SAA, the mean peak plasma concentration (Cmax) of SAA was 318 ng/mL at 0.5 h, the area under the plasma concentration–time curve (AUC0–12 h) was 698 ± 129 ng·h/mL, and the elimination half‐life (T1/2) was 3.29 h. Copyright © 2008 John Wiley & Sons, Ltd.
N‐Tosyloxycarbamates as Reagents in Rhodium‐Catalyzed CH Amination Reactions
Authors: Huard Kim , Lebel Hélène 
Published: June 2008

AbstractMetal nitrenes for use in CH insertion reactions were obtained from N‐tosyloxycarbamates in the presence of an inorganic base and a rhodium(II) dimer complex catalyst. The CH amination reaction proceeds smoothly, and the potassium tosylate that forms as a byproduct is easily removed by filtration or an aqueous workup. This new methodology allows the amination of ethereal, benzylic, tertiary, secondary, and even primary CH bonds. The intramolecular reaction provides an interesting route to various substituted oxazolidinones, whereas the intermolecular reaction gives trichloroethoxycarbonyl‐protected amines that can be isolated with moderate to excellent yields and that cleave easily to produce the corresponding free amine. The development, scope, and limitations of the reactions are discussed herein. Isotopic effects and the electronic nature of the transition state are used to discuss the mechanism of the reaction.
Azacalix[6]arene Hexamethyl Ether: Synthesis, Structure, and Selective Uptake of Carbon Dioxide in the Solid State
Authors: Tsue Hirohito , Ishibashi Koichi , Tokita Satoshi , Takahashi Hiroki , Matsui Kazuhiro , Tamura Rui 
Published: May 2008

AbstractTo investigate dynamic solid‐state complexation hitherto unexplored in nitrogen‐bridged calixarene analogues, azacalix[6]arene hexamethyl ether has been prepared in three steps by applying a 5+1 fragment‐coupling approach by using a Buchwald– Hartwig aryl amination reaction with the aid of our previously devised temporal N‐silylation protocol. X‐ray crystallographic analysis and NMR spectroscopic measurements have revealed that the azacalix[6]arene is well endowed with hydrogen‐bonding ability, by which both the molecular and crystal structures are controlled. The azacalix[6]arene is conformationally flexible in solution on the NMR time scale, whereas it adopts a definite 1,2,3‐alternate conformation with S2 symmetry in the solid state as a result of intramolecular bifurcated hydrogen‐bonding interactions. In the crystal, molecules of the azacalix[6]arene are mutually interacted by intermolecular hydrogen bonds to establish one‐dimensional hexane‐filled nanochannel crystal architecture. Although the single crystal was broken after desolvation, the resultant polycrystalline powder material was capable of selectively adsorbing CO2 among the four main gaseous components of the atmosphere. In contrast, carbocyclic p‐tert‐butylcalix[6]arene hexamethyl ether, the crystal structure of which was also elucidated for the first time in the present study, gave rise to almost no uptake of CO2. Additional solid–gas adsorption experiments for another three gases, such as N2, O2, and Ar, suggested that quadrupole/induced‐dipole interactions and/or hydrogen‐bonding interactions played an important role in permitting the observed selective uptake of CO2 by this new azacalix[6]arene in the solid state.
Classical Reagents: New Surprises in Palladium‐Catalyzed CC Coupling Reactions
Authors: Lindhardt Anders T. , Skrydstrup Troels 
Published: May 2008

AbstractFrom investigations on a relatively simple concept to identify conditions for promoting Mizoroki–Heck reactions with vinyl tosylates and phosphates, two serendipitous discoveries were made concerning new properties of palladium as a catalyst. In the first case, β‐hydride eliminations well known for alkyl metal complexes were found to be equally feasible with alkenyl metal compounds. And secondly, conditions were found for promoting intermolecular ene–yne couplings via a PdII–H intermediate. This coupling reactions represents an atom economical Mizoroki–Heck type reaction.
A General Organocatalytic Enantioselective Malonate Addition to α,β‐Unsaturated Enones
Authors: Wascholowski Veit , Knudsen Kristian Rahbek , Mitchell Claire E. T. , Ley Steven V. 
Published: June 2008

AbstractA general enantioselective organocatalytic conjugate addition procedure of a variety of malonates to α,β‐unsaturated enone systems is presented. The reaction is efficiently catalysed by the pyrrolidinyl tetrazole catalyst 1. Cyclic, acyclic and aromatic enones can be used and the reaction with ethyl malonates 3 b provides the Michael addition products in high yields with good to excellent enantioselectivities. Since only 1.5 equivalents of malonate are used as a reagent, the reaction is readily scaled and practical to operate. Furthermore, the malonate addition products can be easily mono decarboxylated without loss in enantiomeric excess by enzymatic or sodium hydroxide mediated methods.
ChemInform Abstract: Structure and Properties of a New Family of Nearly Equiatomic Rare‐Earth Metal‐Tin‐Germanides RESn1+xGe1‐x (RE: Y, Gd—Tm): An Unusual Example of Site Preferences Between Elements for the Same Group.
Authors: Tobash Paul H. , Meyers John J. , DiFilippo Gary , Bobev Svilen , Ronning Filip , Thompson Joe D. , Sarrao John L. 
Published: June 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: A Rapid Co‐Precipitation and Non‐Isothermal Decomposition Kinetics of New Binary Mn0.5Co0.5 (H2PO4)2×2H2O.
Authors: Boonchom Banjong , Youngme Sujittra , Danvirutai Chanaiporn 
Published: June 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Ruthenium‐Catalyzed Cross‐Coupling of 7‐Azabenzonorbornadienes with Alkynes. An Entry to 3a,9b‐Dihydrobenzo[g]indoles.
Authors: Tenaglia Alphonse , Marc Sylvain 
Published: June 2008

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.