bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, in vitro‐Antimycobacterial Activity and Cytotoxicity of Some Alkyl α‐(5‐aryl‐1, 3, 4‐thiadiazole‐2‐ylthio)acetates
Authors: Foroumadi Alireza , Soltani Fatemeh , Moallemzadeh‐Haghighi Hamideh , Shafiee Abbas 
Published: March 2005

AbstractA new series of alkyl α‐[5‐(5‐nitro‐2‐furyl)‐1, 3, 4‐ thiadiazole‐2‐ylthio] and α‐[5‐(1‐methyl‐5‐nitro‐2‐imidazolyl)‐1, 3, 4‐thiadiazole‐2‐ylthio]acetates (6a–e, 6f–j) were synthesized and evaluated against Mycobacterium tuberculosis as part of the TAACF (Tuberculosis Antimicrobial Acquisition and Coordinating Facility) TB screening program. Primary screening was conducted at the single concentration of 6.25 μg/mL against M. tuberculosis H37Rv in BACTEC 12B medium using a broth microdilution assay, the Microplate Alamar Blue Assay (MABA). The minimum inhibitory concentration (MIC) was determined for compounds demonstrating >90 % growth inhibition in the primary screening. Seven compounds were efficient antimycobacterial agents showing MIC values ranging from 0.78 to 6.25 μg/mL. Among nitrofuran derivatives, methyl (6a), ethyl (6b), and benzyl (6e) esters displayed a good antituberculosis activity (MIC=0.78–3.13 μg/mL) and the others were inactive. In the nitro imidazole series, methyl (6f), ethyl (6g), propyl (6h) and butyl (6i) esters showed significant activity against M. tuberculosis while benzyl (6j) ester was inactive. Also, active compounds were screened by serial dilution to assess toxicity to a VERO cell line. A varying degree of toxicity was observed in nitrofuran and nitroimidazole derivatives (IC50 = 2.3 – >10 μg/mL).
Transition Metal Catalyzed Decarboxylative Additions of Enolates
Authors: Tunge Jon A. , Burger Erin C. 
Published: March 2005

AbstractTransition metal catalyzed decarboxylation of β‐keto acids and esters provides a convenient route for the regiospecific generation of enolates under neutral conditions. Enolates generated by decarboxylation have been utilized in aldol and Michael additions as well as allylic alkylations. The scope and mechanisms of these transformations are discussed. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)
Bystander signaling between glioma cells and fibroblasts targeted with counted particles
Authors: Shao Chunlin , Folkard Melvyn , Michael Barry D. , Prise Kevin M. 
Published: March 2005

AbstractRadiation‐induced bystander effects may play an important role in cancer risks associated with environmental, occupational and medical exposures and they may also present a therapeutic opportunity to modulate the efficacy of radiotherapy. However, the mechanisms underpinning these responses between tumor and normal cells are poorly understood. Using a microbeam, we investigated interactions between T98G malignant glioma cells and AG01522 normal fibroblasts by targeting cells through their nuclei in one population, then detecting cellular responses in the other co‐cultured non‐irradiated population. It was found that when a fraction of cells was individually irradiated with exactly 1 or 5 helium particles (3He2+), the yield of micronuclei (MN) in the non‐irradiated population was significantly increased. This increase was not related to the fraction of cells targeted or the number of particles delivered to those cells. Even when one cell was targeted with a single 3He2+, the induction of MN in the bystander non‐irradiated population could be increased by 79% for AG01522 and 28% for T98G. Furthermore, studies showed that nitric oxide (NO) and reactive oxygen species (ROS) were involved in these bystander responses. Following nuclear irradiation in only 1% of cells, the NO level in the T98G population was increased by 31% and the ROS level in the AG0 population was increased by 18%. Treatment of cultures with 2‐(4‐carboxyphenyl)‐4,4,5,5‐tetramethyl‐imidazoline‐1‐oxyl‐3‐oxide (c‐PTIO), an NO scavenger, abolished the bystander MN induction in non‐irradiated AG01522 cells but only partially in non‐irradiated T98G cells, and this could be eliminated by treatment with either DMSO or antioxidants. Our findings indicate that differential mechanisms involving NO and ROS signaling factors play a role in bystander responses generated from targeted T98G glioma and AG0 fibroblasts, respectively. These bystander interactions suggest that a mechanistic control of the bystander effect could be of benefit to radiotherapy. © 2005 Wiley‐Liss, Inc.
Biostability of polyether–urethane scaffolds: A comparison of two novel processing methods and the effect of higher gamma‐irradiation dose
Authors: Haugen H. , Gerhardt L. C. , Will J. , Wintermantel E. 
Published: March 2005

AbstractThis article deals with enzyme‐induced biodegradation behavior of thermoplastic polyether–urethane (TPU). Porous scaffolds were processed by a new foaming method applied in hot pressing and injection molding. The scaffolds were subsequently γ sterilized. The samples were incubated with cholesterol esterase (CE) for 28 days to simulate an enzymatic degradation order to assess polymer biostability. The main focus of degradation products was the most toxic one: methylene dianiline (MDA). LC/MS was used to separate the breakdown products and to identify possible MDA amounts. The results showed that (a) the hot‐pressed sample released an MDA amount almost twice as large (0.26 ng ± 0.008) as that of the injection‐molded samples (0.15 ng ± 0.003) after incubation with enzyme activity in the physiological range, and (b) a tenfold increase in CE activity revealed considerably higher MDA amounts (7540.0 ng ± 0.004). This enzyme concentration is physiologically unlikely, however, but may occur for extreme high inflammation behavior. Even for extremely high levels of CE enzyme, the scaffold will not discharge MDA above toxic levels. The injection‐molded samples sterilized at 25 kGy seem to represent the most promising processing method. Therefore, the new injection‐molding foaming process of polyether–urethane can be considered appropriate for use as a biomaterial. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater
Doppler sonography of the normal lacrimal gland
Authors: Bilgili Yasemin , Taner Pelin , Unal Birsen , Simsir Ilknur , Kara Simay Altan , Bayram Merih , Alicioglu Banu 
Published: March 2005

AbstractPurposeWe used Doppler sonography to determine the resistance index (RI) and pulsatility index (PI) of the normal lacrimal artery (LA) in both females and males. We also compared the values obtained at various periods of reproductive life.MethodsThe study was performed in 25 prepubertal girls, 28 females of reproductive age, and 27 postmenopausal women, 23 pregnant women, and 104 healthy males. Doppler sonography was used to determine the RI and PI of the LA.ResultsThe mean PI for the entire patient population was 1.48 ± 0.60 and the RI was 0.72 ± 0.09. The RI and PI values of the LA did not differ between males and females. Similarly, the mean RI and PI values of the LA did not change significantly between the various reproductive phases.ConclusionThe PI and RI of the lacrimal gland are similar in both sexes. Moreover, they are not altered by changes in levels of sex steroids. © 2005 Wiley Periodicals, Inc. J Clin Ultrasound 33:123–126, 2005
Sonographic features of Ebstein anomaly associated with hydrops fetalis: A report of two cases
Authors: Tongsong Theera , Chanprapaph Pharuhas , Khunamornpong Surapan , Sirichotiyakul Supatra 
Published: March 2005

AbstractEbstein anomaly, an abnormally low insertion of the tricuspid valve, occurs in 0.5% of patients with congenital heart disease. In rare cases, this disorder may be complicated by congestive heart failure in utero and hydrops fetalis. This article reports the prenatal sonographic features of 2 cases of Ebstein anomaly associated with hydrops fetalis. In both cases, fetal echocardiography was performed at 34 weeks of gestation. The 4‐chamber view showed fetal cardiomegaly and pericardial effusion. In both cases, the annular attachment of the tricuspid valve leaflets was difficult to demonstrate and so distal that it could easily be confused with papillary muscle in the right ventricular wall. Poor fetal cardiac hemodynamics with severe tricuspid regurgitation was demonstrated by pulsed Doppler imaging. Pulmonary regurgitation was also clearly demonstrated in both cases. Preterm delivery with stillbirth occurred in both cases. Autopsies confirmed the very distal displacement of the tricuspid valve insertion, close to the apex, and enlargement of the right atrium. © 2005 Wiley Periodicals, Inc. J Clin Ultrasound 33:149–153, 2005
Transcriptional regulation of connexin 43 expression by retinoids and carotenoids: Similarities and differences
Authors: Vine Alex L. , Leung Yee M. , Bertram John S. 
Published: March 2005

AbstractGap junctions, connexons, are formed by assembly of trans‐membrane connexin proteins and have multiple functions including the coordination of cell responses. Most human tumors are deficient in gap junctional communication (GJC) and restoration of GJC by forced expression of connexins reduces indices of neoplasia. Expression of connexin 43 (Cx43), the most widely‐expressed connexin family member, is upregulated by cancer‐preventive retinoids and carotenoids in normal and preneoplastic cells; an action considered of mechanistic significance. However, the molecular mechanism for upregulated expression is poorly understood. The retinoic acid receptor antagonist Ro 41‐5253 was capable of suppressing retinoid‐induction Cx43 luciferase reporter construct in F9 cells, but did not suppress reporter activity induced by the non‐pro‐vitamin A carotenoids astaxanthin or lycopene, indicating that retinoids have separate mechanisms of gene activation than non‐pro‐vitamin A carotenoids. Neither class of compound required protein synthesis for induction ofCx43mRNA, nor was the 5.0 h half‐life ofCx43mRNA altered, indicating direct transcriptional activation. The responsive region was found within −158 bp and +209 bp of the transcription start site; this contains a Sp1/Sp3 GC‐box to which Sp1 and Sp3 were bound, as revealed by electrophoretic mobility shift assays (EMSA), but no retinoic acid response element (RARE). Site directed mutagenesis of this GC‐box resulted in increased basal levels of transcription and loss of responsiveness to a synthetic retinoid. In this construct astaxanthin and lycopene produced marginally, but not significantly higher, reporter activity than the control. © 2005 Wiley‐Liss, Inc.
Characterization of the nuclear import of human MutLα
Authors: Brieger A. , Plotz G. , Raedle J. , Weber N. , Baum W. , Caspary W.F. , Zeuzem S. , Trojan J. 
Published: March 2005

AbstractDNA mismatch repair (MMR) is essential for the maintenance of replication fidelity. Its major task is to recognize mismatches as well as insertion/deletion loops of newly synthesized DNA strands. Although different players of human MMR have been identified, the regulation of essential steps of MMR is poorly understood. Because MMR is initiated in the nucleus, nuclear import might be a mechanism to regulate MMR. Nuclear targeting is accomplished by conserved signal sequences called nuclear localization signals (NLS), which represent clusters of positively charged amino acids (aa). hMLH1 contains two clusters of positively charged amino acids, which are candidate NLS sequences (aa 469–472 and 496–499), while hPMS2 contains one (aa 574–580). To study the effect of these clusters on nuclear import, NLS mutants of hMLH1 and hPMS2 were generated and expressed in 293T cells. The subcellular localization of the mutant constructs was monitored by confocal laser microscopy. We demonstrated that missense mutations of two signal sequences, one in hMLH1 and one in hPMS2, lead to impaired nuclear import, which was especially prominent for mutants of the hMLH1 residues K471 and R472; and hPMS2 residues K577 and R578. © 2005 Wiley‐Liss, Inc.
The strongly connected reliability of complete digraphs
Authors: Brown J.I. , Li Xiaohu 
Published: March 2005

AbstractGiven a digraph D, consider the model where each vertex is always operational, but the edges are independently operational with probability p. The strongly connected reliability of D, scRel(D,p), is the probability that the spanning subgraph of D consisting of the operational edges is strongly connected. One can view strongly connected reliability as the probability that any vertex can send information to any other vertex, given that edges fail independently. There are very few classes for which there is an efficient algorithm for calculating the strongly connected reliability. This article presents the fist polynomial time algorithm for computing the strongly connected reliability of complete digraphs, that is, digraphs in which every vertex is joined to every other vertex by exactly one edge (one in each direction). © 2005 Wiley Periodicals, Inc. NETWORKS, Vol. 45(3), 165–168 2005
Synthesis and characterization of reactive copolymeric microgels
Authors: Pérez Leyre , Sáez Virginia , Hernáez Estíbaliz , Herrero M Teresa , Rodríguez Elena , Katime Issa 
Published: March 2005

AbstractHydrogels whose diameters range in the nanosize scale were synthesized by precipitation copolymerization of 4‐nitrophenol acrylate (NPA) with methacrylamide (MeAM) and N‐isopropylacrylamide (NIPAM). The polymerization reaction process was followed by attenuated total reflectance Fourier‐transform infrared spectrometry (ATR‐FTIR) and the conversion was studied by UV‐vis spectrometry. Poly(NPA‐co‐MeAM) and poly(NPA‐co‐NIPAM) microgels were characterized by proton nuclear magnetic resonance (1H‐NMR) spectrometry. The thermal properties were studied by both thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. Transmission electron microscopy (TEM) of these microgels showed that the copolymer is located in spherical particles with a moderate polydispersity. The average particle diameter and the particle size distribution were measured in acetone by quasi‐elastic light scattering (QELS), which indicated a mean diameter close to 50 nm. Copyright © 2005 Society of Chemical Industry
Collagen‐based scaffolds reinforced by chitosan fibres for bone tissue engineering
Authors: Li Xiaoming , Feng Qingling , Jiao Yunfeng , Cui Fuzhai 
Published: March 2005

AbstractIn this paper, porous bone scaffolds reinforced with chitosan fibres were prepared. The porosity and pore size of the reinforced scaffolds were both satisfactory. The reinforced scaffolds resembled natural bone in both components and crystal size. Only if the length of the fibres was no shorter than the critical length, could the fibres reinforce the material. We have proposed an empirical formula to calculate the critical length of the fibres for the porous materials and determined the modifying factor (Fl) for the porous bone scaffold investigated in this work. Along with the increase of the fibres' volume content, the compressive strength of the scaffold also increased. We have proposed a further empirical formula for calculating the compressive strength of the porous reinforced materials and determined the modifying factor (Fσ) for the porous reinforced bone scaffold examined in these studies. Along with the degradation in vitro, the decrease in strength of the reinforced scaffold was less than that of the unreinforced scaffold. The growth rate of osteoblast cells on the reinforced scaffold was higher than that on the unreinforced scaffold. These results suggest that the reinforced scaffold may be a promising candidate matrix for repairing large bone defects. Copyright © 2005 Society of Chemical Industry
Phase separation in binary mixtures containing polymers: A quantitative comparison of single‐chain‐in‐mean‐field simulations and computer simulations of the corresponding multichain systems
Authors: Müller Marcus , Smith Grant D. 
Published: March 2005

AbstractWe discuss a phenomenological, coarse‐grained simulation scheme, single‐chain‐in‐mean‐field (SCMF) simulation, for investigating the kinetics of phase separation in dense polymer blends and mixtures of polymers and solvents. In the spirit of self‐consistent‐field calculations, we approximate the interacting multichain problem by that of a single chain in an external field, which, in turn, depends on the local densities of the components. To study the time evolution of the mixture, we perform an explicit Monte Carlo (MC) simulation of an ensemble of independent chains in the external field and periodically calculate the average densities and update the external field. Unlike dynamic self‐consistent‐field theory, these SCMF simulations do not assume that the chain conformations relax much more quickly than the density and incorporate the single‐chain dynamics explicitly rather than via an Onsager coefficient. This allows us to study systems with large spatial inhomogeneities and dynamic asymmetries. To assess the accuracy and limitations of the simulation scheme, we compare the results of SCMF simulations using a discretized Edwards Hamiltonian with computer simulations of the corresponding multichain system for (1) the early stages of spinodal decomposition of a symmetric binary polymer blend in response to a quench from χN = 0.314 to χN = 5 (where χ is the Flory–Huggins parameter and N is the number of segments), for which the growth rate of composition fluctuations is compared with MC simulations of the bond fluctuation model and alternative dynamic self‐consistent‐field calculations, and (2) the evaporation of a solvent from a low‐molecular‐weight thin polymer film, for which a comparison is made with molecular dynamics (MD) simulations of a bead‐necklace model with a monomeric solvent. In the latter case, the polymer conformations are extracted from MD simulations and modeled in the SCMF simulations by a discretized Edwards Hamiltonian augmented by a chain‐bending potential. From the MD simulations of thin polymer films in equilibrium with its vapor, phase coexistence has been determined, and the second‐ and third‐order virial coefficients in the SCMF simulations have been adjusted accordingly. Finally, MD simulations of bulk solutions of a polymer and a solvent over a range of compositions, as well as the pure solvent at various densities, have been performed to determine self‐diffusion coefficients that enter the SCMF simulations in the form of density‐dependent segmental mobilities. A comparison of the polymer and solvent profiles in a thin film as a function of time and the fraction of the solvent evaporating from a solvent‐swollen film, as obtained from MD simulations and parameterized SCMF simulations, shows satisfactory agreement for this simple mapping procedure. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 934–958, 2005
Simulation of plastic deformation in glassy polymers: Atomistic and mesoscale approaches
Authors: Shenogin Sergei , Ozisik Rahmi 
Published: March 2005

AbstractThe mechanism of deformation in glasses is very different from that of crystals, even though their general behavior is very similar. In this study, we investigated the deformation of polycarbonate on the atomistic scale with molecular dynamics and on the continuum scale with a new simulation approach. The results indicated that high atomic/segmental mobility and low local density enabled the formation (nucleation) of highly deformed regions that grew to form plastic defects called plastic shear transformations. A continuum‐scale simulation was performed with the concept of plastic shear transformations as the basic region of deformation. The continuum simulations were able to predict the primary and secondary creep behavior. The slope of the secondary creep depended on the interactions between the plastic shear transformations. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 994‐1004, 2005
Biogeochemical and hydrological controls on carbon export from a forested catchment in central Japan
Authors: Kawasaki Masatoshi , Ohte Nobuhito , Katsuyama Masanori 
Published: March 2005

AbstractHere we review research on the links between hydrological processes and the biogeochemical environment controlling the dynamics of dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in temperate forested catchments. In addition, we present the results of original experiments. The spatial and temporal changes in DIC and DOC concentrations were investigated in tandem with observations of elementary belowground hydrological processes for a forested headwater catchment in central Japan. The soil CO2 gas concentration, which is the source of DIC, increased with depth. The hydrological characteristics of groundwater also affected the spatial variation of partial pressure of dissolved CO2 (pCO2) in groundwater. The temporal variations in the soil CO2 gas concentration and the pCO2 values of groundwater suggested that the dynamics of DIC were strongly affected by biological activity. However, the geographical differences in DIC leaching were affected not only by the link between climatological conditions and biological activity, but also by other factors such as geomorphologic conditions. The DOC concentrations decreased with selective removal of hydrophobic acid during vertical infiltration. The major DOC‐removal mechanisms were retention of metal‐organic complexes to soil solids in the upper mineral soil layer and decomposition of DOC in the lower mineral soil layer. The responses of the DIC and DOC concentrations to changes in discharge during storm events were explained by the spatial variation in the DIC and DOC concentrations. Seasonal variation, which represents a long‐term change, in stream water DOC concentrations was affected not only by the temporal variation in DOC concentrations in the topsoil, which may be affected by biological activity, but also by water movement, which transports DOC from the topsoil to stream water. These results indicate that both a biogeochemical approach and a method for evaluating the hydrological effects on carbon dynamics are critical for clarifying the carbon accumulation‐and‐release processes in forested ecosystems.
Ælfric and late Old English verse
Authors: Bredehoft Thomas A. 
Published: March 2005

In his discussion of the formal structures characteristic of Ælfric's ‘rhythmical prose’ style, John C. Pope prints the following passage from Ælfric's homily on Cuthbert, calling attention especially to the pointing, given as it appears in Cambridge, University Library, Gg. 3. 28 (?Cerne, s. x/xi):Ac an ðære fugela. eft fleogende com.ymbe ðry dagas. þearle dreorig.fleah to his foton. friðes biddende.þæt he on ðam lande. lybban moste.symle unscæððig. and his gefera samod.