bluuebunny/crossref_metadata_2025_split huggingface dataset:
Group 4 Complexes of Chelating Dianionic [OSO] Binaphtholate Ligands; Synthesis and Alkene Polymerisation Catalysis
Authors: Natrajan Louise S. , Wilson Claire , Okuda Jun , Arnold Polly L. 
Published: July 2004

AbstractMono‐ and bis(ligand)titanium and ‐zirconium complexes of a sulfur‐bridged binaphtholate [1,1′‐S(2‐HOC10H4‐tBu2‐3,6)2] (H2LSN) have been synthesised and characterised. Complexes of the general form [M(LSN)X2] (X = Cl, CH2Ph) are prepared by protonolysis or metathesis. X‐ray crystallographic structural characterisation of the dibenzyl complex [Zr(LSN)(CH2Ph)2] is reported, as well as the structure of its partially oxidised derivative [Zr(LSN)(CH2Ph)(OCH2Ph)]2. Complexes of the form [M(LSN)2] are readily formed; these can be converted by comproportionation reactions into the mono‐LSN derivatives above. The X‐ray crystal structure of a bis(sulfur‐bridged biphenolate) is presented. The representative complexes have been tested as alkene polymerisation catalysts, in conjunction with a methylalumoxane cocatalyst, and for the first time a zirconium complex of a sulfur‐bridged biphenolate‐type ligand has been found to be active in the polymerisation of ethene. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Clonal diversity and subpopulation structure in central European relict populations ofSaxifraga paniculataMill.(Saxifragaceae)
Authors: Reisch C. , Poschlod P. 
Published: July 2004

AbstractSaxifraga paniculatais a rare and endangered glacial relict in central Europe. It shows high clonal reproduction. In this study, we analysed the clonal diversity and the subpopulation structure of three populations from the species main distribution area in Germany outside of the Alps (Swabian Alb, Black Forest, Nahe Mountains). We used RAPD analysis to detect the genetic variation inS. paniculataand found high levels of clonal diversity. The percentage of distinguishable genotypes (PD) within populations ofS. paniculatawas 1.0 and even spatially well defined mats of rosettes consisted of several genotypes. In a cluster analysis, the investigated populations were clearly separated from each other. However, we detected no genetic differentiation among subpopulations. We ascribe the high level of genotypic variability to the species' mixed mating system, which creates and maintains high levels of genetic diversity within the populations ofS. paniculata. Clonal reproduction seems, meanwhile, to be of secondary importance for the propagation of the species. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Recolonisation of natural landslides in tropical mountain forests of Southern Ecuador
Authors: Ohl C. , Bussmann R. 
Published: July 2004

AbstractThe regeneration of the vegetation of natural landslides was studied at Estación Científica San Francisco (ECSF) in a tropical mountain forest area of Southern Ecuador, north of Podocarpus National Park. The study focused on the process of regeneration on natural landslides and the vegetation change along an altitudinal gradient using space‐for‐time substitution. The most important plant families present on the landslides during the first stages of succession are Gleicheniaceae (Pteridophyta), Melastomataceae, Ericaceae and Orchidaceae. Species of the genus Sticherus (Gleicheniaceae) are dominant, and species composition varies with altitude and soil conditions. Colonisation of landslides is not homogeneous. Zones with bare ground, sparsely vegetated patches and densely covered areas may be present within the same slide. This small scale spatial heterogeneity is often created by local ongoing sliding processes and different distances towards undisturbed areas. Therefore, the duration of the successional process is highly variable. The initial stage of the succession is a community of non vascular plants interspersed with scattered individuals of vascular plants. By means of runner‐shoots they form vegetation patches which start growing into each other. The second stage is dominated by Gleicheniaceae (species composition varying in altitude and soil chemistry). In the third stage, bushes and trees colonise, sheltered by the ferns, and a secondary forest develops with pioneer species that are not found in the primary forest vegetation. The common phenomenon of the natural landslides leads to an increase in structural and species diversity on a regional scale. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High sensitivity of chemiluminescent methodology for detection of clonal CDR3 sequences in patients with acute lymphoblastic leukemia
Authors: Leal E. , Jaloma‐Cruz A. R. , Barros‐Núñez P. 
Published: July 2004

AbstractDetection of minimal residual disease (MRD) in patients with B‐cell acute lymphoblastic leukemia (B‐ALL) has been achieved using several radioactive labelling methodologies; however, limited information exists about the use of chemiluminescent labelling. Although many malignant disorders are related to cytogenetic alterations, there is not a consistent chromosomal translocation that could serve as a tumour marker for the monitoring of MRD. ALL are derived from B‐lymphocytes in 80% of cases. In the early stages of their maturation, the immunoglobulin heavy chain genes (IgH) undergo rearrangements among their V, D, and J segments, giving rise to the Complementary Determining Regions (CDR). Among these, CDR3 is considered unique for each lymphocyte and used as a tumour‐specific marker in B‐ALL patients. In this study, the CDR3 was labelled with digoxigenin and used as a patient‐specific probe to test its sensitivity for further detection of MRD. Fourteen pretreatment samples of bone marrow (BM) or peripheral blood (PB) from B‐ALL patients were included. Tumour‐specific probes were designed from each clonal product by elimination of the consensus sequences. Ten digoxigenin‐labelled probes were hybridized with a mixture of their respective clonal DNA and the polyclonal product from a normal healthy donor, in serial dilutions from 1:1 up to 1:107. A sensitivity range of 1:103–1:106 was obtained, with an average of 1:105. Crossed tests performed in four patients, showed right probe specificity in all cases. We propose that the design of allele‐specific probes with chemiluminescent labelling, represents a reliable, sure and sensitive alternative methodology for MRD detection in patients with B‐cell lymphoproliferative disorders. Copyright © 2004 John Wiley & Sons, Ltd.
Bone formation and bioresorption after implantation of injectable β‐tricalcium phosphate granules–hyaluronate complex in rabbit bone defects
Authors: Chazono Masaaki , Tanaka Takaaki , Komaki Hirokazu , Fujii Katsuyuki 
Published: July 2004

AbstractThe objective of this study was to evaluate the effects of a complex of β‐tricalcium phosphate (β‐TCP) granules and 3.5% hyaluronate (β‐TCP granules–HY complex) compared with a β‐TCP block, in terms of osteoconductivity and biodegradability, to determine whether this complex would be a good candidate for bone void filler. Both materials were implanted into cavities drilled in rabbit femoral condyles. New bone formation and mineral apposition rate were evaluated to analyze osteoconductivity, whereas residual β‐TCP within the defects and tartrate‐resistant acid phosphatase (TRAP) cellular activity were studied for β‐TCP resorption. The results show that both the β‐TCP block and the β‐TCP granules–HY complex support bone ingrowth; however, bioresorption was rapid for β‐TCP granules–HY but weak for β‐TCP block. This biodegradation mechanism was considered to be a cell‐mediated disintegration by numerous TRAP‐positive giant cells. The time lag between the peak value of TRAP‐positive giant cell population and that of new bone formation rate suggests that a coupling‐like phenomenon could be occurring in the β‐TCP‐filled bone defects. In addition, β‐TCP granules–HY complex, which is an injectable, pastelike material, has similar osteoconductive properties to β‐TCP block. Thus, this complex may be useful as a bone filler in clinical application. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 542–549, 2004
Evaluation of in vivo biocompatibility and biodegradation of photocrosslinked hyaluronate hydrogels (HADgels)
Authors: Miyamoto Kenji , Sasaki Masanori , Minamisawa Yuka , Kurahashi Yasuhiro , Kano Hiroki , Ishikawa Shin‐ichi 
Published: July 2004

AbstractHADgels are newly developed photocrosslinked hyaluronate hydrogels. They are produced from an aqueous solution of a hyaluronan derivative (HAD) in which cinnamic acid is introduced into the carboxyl moiety of hyaluronan using 3‐aminopropanol as a spacer. High‐energy ultraviolet irradiation of the HAD solution induces photodimerization of cinnamic acid, resulting in the development of a macromolecular network of each hyaluronan to water‐insoluble hydrogels. The biocompatibility and biodegradation of HADgels were evaluated by guinea pig intracutaneous injection testing for up to 28 days. By macroscopic and histological observations, HADgels showed good tissue compatibility and did not induce excess inflammation at the injection sites. Biodegradation of the HADgels clearly depended on the degree of crosslinking at the fixed weight concentrations of HAD (0.5% and 1.0%). In addition, serum analyses showed that the injected guinea pigs did not produce specific antibodies against HADgels. These results indicate that HADgels have preferable biocompatibility and can be used as a new class of injectable, absorbable biomaterial, especially for preventing postsurgical adhesion formations. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 550–559, 2004
Regulation of histone deacetylase activities
Authors: Sengupta Nilanjan , Seto Edward 
Published: July 2004

AbstractHistone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from lysine residues in both histone and non‐histone proteins. They play a key role in the regulation of gene transcription and many other biological processes involving chromatin. Significantly, recent studies suggest that HDACs are critically involved in cell‐cycle regulation, cell proliferation, differentiation, and in the development of human cancer. HDAC inhibitors currently are being exploited as potential anti‐cancer agents. As expected for vital regulators of many cellular processes, the activities of HDACs are tightly controlled and precisely regulated by multiple mechanisms. The activities of most if not all HDACs are regulated by protein–protein interactions. In addition, many HDACs are regulated by post‐translational modifications as well as by subcellular localization. Less studied, but perhaps equally important, is the regulation of some HDACs by control of expression, availability of cofactors, and by proteolytic processing. A complete understanding of how HDACs are regulated will contribute not only to our overall knowledge of chromatin structure and gene control, but will offer tremendous insight into approaches for developing therapeutic HDAC inhibitors with improved specificity. © 2004 Wiley‐Liss, Inc.
Synthesis and biodistribution in mice of a new 99mTc nitrido complex for brain imaging
Authors: Zhang Junbo , Wang Xuebin , Liu Jing 
Published: July 2004

AbstractThe bis(N‐cyclopentyl dithiocarbamato) nitrido technetium‐99m complex 99mTcN(CPEDTC)2 was synthesized by the reduction of 99mTcO into [99mTc≡N]2+ with stannous chloride in the presence of succinic dihydrazide and propylenediamine tetraacetic acid, followed by the addition of sodium N‐cyclopentyl dithiocarbamate monohydrate. The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography(TLC) and high performance liquid chromatography(HPLC). In vitro studies showed that the complex possessed good stability under physiological conditions. Its partition coefficient studies indicated it was a good lipophilic complex. The electrophoresis results showed the complex was neutral. The biodistribution results in mice indicated that 99mTcN(CPEDTC)2 was significantly retained into the brain. The brain uptake(ID%/g) was 3.58, 5.26, 3.73 and 2.72 and the brain/blood ratios were 0.79, 1.69, 1.59 and 1.58 at 5, 30, 60 and 90 min post‐injection, respectively. These results suggested potential usefulness of the complex as a new brain perfusion imaging agent. Copyright © 2004 John Wiley & Sons, Ltd.
The vascular response induced by transmyocardial laser revascularization is determined by the size of the channel scar: Results of CO2, holmium and excimer lasers
Authors: Huikeshoven Menno , Beliën Jeroen A.M. , Tukkie Raymond , Beek Johan F. 
Published: July 2004

AbstractBackground and ObjectivesTo investigate the angiogenic effect of CO2, Ho:YSGG, and XeCl excimer TMLR in a rat model with morphologic characteristics of chronic myocardial ischemia.Study Design/Materials and MethodsTwo channels (200–320 μm) were created per rat heart. After 14 days, vessel numbers and densities in and around laser scars were assessed.ResultsCapillary densities in the laser scars were equal between the three lasers (∼130 vessels/mm2) but much lower than in control areas (∼2,100 vessels/mm2). Vessel densities excluding capillaries were significantly higher in Ho:YSGG and CO2 scars compared to excimer scars, while only Ho:YSGG scars contained significantly more large vessels (diameter ≥ 20 μm) than control areas. Only rarely, extension of vascular growth into adjacent myocardium was observed in any of the three groups.ConclusionsThese results indicate that the angiogenic response following TMLR is limited to the channel scar and related to the scar size rather than the specific laser type. Lasers Surg. Med. 35:35–40, 2004. © 2004 Wiley‐Liss, Inc.
Synthesis of Well‐Defined Hybrid Macromonomers of Poly(ethylene oxide) and Their Reactivity in Photoinitiated Polymerization
Authors: Du Juan , Murakami Yoshitaka , Senyo Takamichi , Adam  , Ito Koichi , Yagci Yusuf 
Published: July 2004

AbstractSummary: α,ω‐Hybrid (hetero‐telechelic) poly(ethylene oxide) (PEO) macromonomers carrying both cationic and radical or anionic polymerizable vinyl end groups were newly synthesized by the living anionic polymerization of ethylene oxide (EO) initiated with partially K‐alkoxidated vinylic alcohols such as the monovinyl ether of tetramethylene glycol or di(ethylene glycol) and p‐vinylbenzyl alcohol (VBA), followed by reaction with methacryloyl chloride (MAC). They possess a couple of α‐ and ω‐end groups that can polymerize concurrently or selectively by radical and/or cationic or anionic mechanism. The reactivity of the radical and cationic species formed upon photolysis of benzophenone and triphenylsulfonium tetrafluoroborate towards these end groups were studied by means of 1H NMR analysis following the disappearance of the respective olefinic groups. Studies with macromomonomers and model compounds revealed that photoexcited benzophenone abstracts hydrogen atoms from the PEO backbone to form radicals without added hydrogen donors. In the case of the sulfonium salt, both radical and cationic species are formed, which react with the respective functional groups. It was also shown that vinyl ether moieties react more readily than the methacrylate in both radical and cationic processes.The general synthetic strategy followed for the preparation of the hybrid PEO macromonomers studied here.magnified imageThe general synthetic strategy followed for the preparation of the hybrid PEO macromonomers studied here.
Enthalpy of Swelling of Potassium Polyacrylate and Polymethacrylate Hydrogels. Evaluation of Excluded‐Volume Interaction
Authors: Safronov Alexander P. , Smirnova Yelena A. , Pollack Gerald H. , Blyakhman Felix A. 
Published: July 2004

AbstractSummary: The enthalpy of swelling over the entire concentration range in potassium polyacrylate and polymethacrylate hydrogels with varying charge density was measured by means of isothermal Calvet microcalorimetry at 298 K. Concentration plots of the enthalpy of swelling at polymer volume fractions up to 50% were used for evaluation of Flory‐Huggins binary parameter of interaction. Apparent values of χ determined directly from experimental plots revealed extremely strong concentration dependence at high degrees of swelling. This was taken as evidence for the overlap of electrostatic and excluded‐volume interactions. The separate evaluation of these contributions to the enthalpy of swelling was performed using the recent theory developed for the enthalpy of dilution in semi‐dilute polyelectrolyte solutions. The mean value of the parameter χ over a wide range of swelling for the uncharged poly(acrylic acid) and poly(methacrylic acid) gel was found equal to 0.21 and −0.50 respectively. The ionization of the gel network due to the introduction of potassium salt residues resulted in the progressive decrease in the quality of the solvent. At 40–50% of ionization, the binary interaction parameter was about 2.8 both for potassium polyacrylate and polymethacrylate hydrogels. That value is much more than the critical value for liquid‐liquid phase separation in non‐electrolyte polymer solutions.
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Saccharide Polymers 6
Authors: Boltres Daniela , Schmalbruch Bodo , Buchholz Klaus 
Published: July 2004

AbstractSummary: The 2,4,6‐tri‐O‐acetyl‐3‐deoxy‐D‐erythro‐hex‐2‐enono‐1,5‐lactone, briefly Ac‐Gluc‐enlactone (GEL) (1), is easily synthesized in an one‐step reaction from glucono‐δ‐lactone with good yields. Free radical polymerizations of GEL with vinyl esters with side chain of different length including fatty acids esters were carried out in substance or in solution under various conditions. The structures and chemical compositions of the polymers were established by elemental analysis, FT‐IR‐, 1H‐, and 13C NMR spectroscopy. Copolymerization kinetics were investigated. Characteristic properties of polymers, e.g. molecular weight, optical rotation, and thermal properties are reported. The products are of interest as components in commodities with binding and adhesive properties.
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BASF on Campus
Authors: Schädler Volker 
Published: July 2004

AbstractMacromolecular News: This section contains news of the macromolecular community all over the world. Articles about, for example, people, projects, and market trends are welcome. Suggestions should be sent to the editorial office of the Macromolecular journals, preferably by E‐mail to macromol@wiley‐vch.de. The editorial office decides which articles will be published.
Temperature‐sensitive defects in paramyotonia congenita mutants R1448C and T1313M
Authors: Dice Margaret S. , Abbruzzese Jennifer L. , Wheeler James T. , Groome James R. , Fujimoto Esther , Ruben Peter C. 
Published: July 2004

AbstractThe biophysical origins of paramyotonia congenita and its exacerbation in cold temperatures were examined. Human skeletal muscle voltage‐gated sodium channels were expressed in Xenopus oocytes and macroscopic currents were recorded from cell‐attached patches. Wild‐type (hNaV1.4) channels were compared to two mutant channel isoforms, T1313M and R1448C. The voltage dependence and temperature sensitivity of activation, fast‐inactivation onset and recovery, and deactivation were studied. Although activation and the onset of fast‐inactivation were temperature sensitive in all three isoforms, and although these properties in mutant channels differed from those in wild‐type channels, they did not account for cold‐exacerbation. Deactivation, however, was disproportionately slower in R1448C, but not in T1313M, than in hNaV1.4. These defects may, at least in part, account for the clinical symptoms of paramyotonia congenita and its exacerbation by cold, and provide a basis for studies into the therapeutic alleviation of these symptoms. Muscle Nerve 30: 277–288, 2004
Diabetic amyotrophy progressing to severe quadriparesis
Authors: Taylor Bruce V. , Dunne John W. 
Published: July 2004

AbstractDiabetic amyotrophy is a distinctive form of diabetic neuropathy usually characterized by the abrupt onset of pain and asymmetric proximal leg weakness and wasting. Involvement of the upper limbs is unusual, and prognosis is said to be good. We describe two patients, each with type II diabetes mellitus, who presented with diabetic amyotrophy progressing to severe quadriparesis. One patient remains severely disabled. The clinical spectrum of diabetic amyotrophy includes progression to severe quadriparesis. Muscle Nerve 30: 505–509, 2004
Cytoskeletal myotoxicity from simvastatin and colchicine
Authors: Baker Steven K. , Goodwin Susan , Sur Monalisa , Tarnopolsky Mark A. 
Published: July 2004

AbstractWe report the case of a 79‐year‐old man with mild chronic renal failure who developed severe rhabdomyolysis after combined exposure to simvastatin and colchicine. Colchicine induces myopathy through disruption of microtubular function with subsequent vacuolization and pseudomyelinic body accumulation. Statin therapy is associated with myonecrosis, membranous myeloid bodies, and vacuolization, presumably as a function of impaired isoprenoid metabolism. Vesicle trafficking requires small G‐protein prenylation and statins can disrupt cytoskeletal integrity. We propose that synergistic cytoskeletal myotoxicity may account for the extreme elevation of serum creatine kinase not previously reported in pure colchicine myopathy. Muscle Nerve, 2004
A comparative study of knowledge about and attitudes toward the combined oral contraceptives among Korean and Japanese university students
Authors: Lim Hyun‐Ja , Lee Myeong Soo , Cho Yoo‐Hyang , Kazumi Uchiyama 
Published: July 2004

AbstractPurposeTo compare university students' knowledge about and attitudes toward the combined oral contraceptives (COC) in two countries with different pharmaceutical systems (Japan and Korea), and to explore the reasons limiting the use of the COC in these populations.MethodsUniversity students in Korea and Japan completed a questionnaire containing a total of 55 questions about the students' demographics (8 questions), knowledge about the COC (15 questions), attitudes toward the COC (24 questions) and the reasons for limited use of the COC among the population (8 questions).ResultsMale students' attitudes toward the COC were significantly more positive than those of female students in Korea, but not in Japan. Knowledge about and attitudes toward the COC did not differ significantly between the two countries. The age at which students desired to use the COC was significantly correlated with age in both countries. There were significant correlations between knowledge about and attitude towards the COC in both countries and between age and attitude towards the COC in Japan. In both countries, the most commonly cited reasons for limited use of the COC were concern about adverse side effects.ConclusionsThese results confirm the need to develop appropriate sex education programs in Korea and Japan. Cultural differences and differences in the pharmaceutical and medical systems between the two countries should be considered when designing sex education programs for young people in Korea and Japan. Copyright © 2004 John Wiley & Sons, Ltd.