bluuebunny/crossref_metadata_2025_split huggingface dataset:
Efficient blue‐green‐emitting poly[(5‐diphenylamino‐1,3‐phenylenevinylene)‐alt‐(2,5‐dihexyloxy‐1,4‐phenylenevinylene)] derivatives: Synthesis and optical properties
Authors: Liao Liang , Cirpan Ali , Ding Liming , Karasz Frank E. , Pang Yi 
Published: February 2006

AbstractNew poly(phenylene vinylene) derivatives with a 5‐diphenylamino‐1,3‐phenylene linkage (including polymers 2, 3, and 5) have been synthesized to improve the charge‐injection properties. These polymers are highly photoluminescent with fluorescent quantum yields as high as 76% in tetrahydrofuran solutions. With effective π‐conjugation interruption at adjacent m‐phenylene units, chromophores of different conjugation lengths can be incorporated into the polymer chain in a controllable manner. In polymer 2, the structural regularity leads to an isolated, well‐defined emitting chromophore. Isomeric polymer 3 of a random chain sequence, however, allows the effective emitting chromophores to be joined in sequence by sharing a common m‐phenylene linkage (as shown in a molecular fragment). Double‐layer light‐emitting‐diode devices using 2, 3, and 5 as emitting layers have turn‐on voltages of about 3.5 V and produce blue‐green emissions with peaks at 493, 492, and 482 nm and external quantum efficiencies up to 1.42, 0.98, and 1.53%, respectively. In comparison with a light‐emitting diode using 2, a device using 3 shows improved charge injection and displays increased brightness by a factor of ∼3 to 1400 cd/m2 at an 8‐V bias. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2307–2315, 2006
Initiator‐fragment incorporation radical copolymerization of vinyl acetate and 1,2‐polybutadiene as a multivinyl monomer
Authors: Sato Tsuneyuki , Ono Atsushi , Hirano Tomohiro , Seno Makiko 
Published: February 2006

AbstractThe copolymerization of vinyl acetate (VAc) with 1,2‐polybutadiene (1,2‐PB; 85.5% 1,2‐units and 14.5% 1,4‐units) as a multivinyl monomer was carried out at 80 °C in dioxane with dimethyl 2,2′‐azobisisobutyrate (MAIB) at high concentrations (0.10–0.50 mol/L) as an initiator. The copolymerization of 1,2‐PB [0.80 mol/L (monomer unit)] and VAc (1.20 mol/L) with MAIB (0.30 mol/L) for 4 h proceeded homogeneously without gelation to yield a soluble copolymer. The resulting copolymer was divided into methanol‐ and n‐hexane‐insoluble parts, of which the yields based on the total weight of the comonomers and initiator were 46 and 20%, respectively. The methanol‐insoluble part consisted of the fractions of the 1,2‐PB units with (9 mol %) and without (39 mol %) an intact double bond, the 1,4‐PB unit (8 mol %), the VAc unit (32 mol %), and the methoxycarbonylpropyl group (12 mol %) as the MAIB fragment, whereas the hexane‐insoluble one was composed of the fraction of the 1,2‐PB units with (4 mol %) and without (17 mol %) a double bond, the 1,4‐PB unit (4 mol %), the VAc unit (60 mol %), and the methoxycarbonylpropyl group (15 mol %). The use of higher concentrations of 1,2‐PB and VAc and lower concentrations of MAIB resulted in gelation. The cast film from a chloroform solution of the methanol‐insoluble part contained spherical pores organized in a hexagonal way with a monodisperse pore size of 3 μm. The copolymer molecules seemed to be arranged in an ordered way on the surface layer of the pores, as shown by an optical microscopy image under crossed polarizers. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2328–2337, 2006
Induction of apoptosis and inhibition of NF‐κB activation in human prostate cancer cells by the cis‐9, trans‐11 but not the trans‐10, cis‐12 isomer of conjugated linoleic acid
Authors: Song Hyun‐Ju , Sneddon Alan A. , Heys Steven D. , Wahle Klaus W.J. 
Published: February 2006

AbstractBACKGROUNDConjugated linoleic acids (CLAs) have anti‐tumorigenic properties in animal models and anti‐proliferative effects on cancer cells in vitro. Previous studies have shown that the NF‐κB pathway is involved regulating anti‐apoptotic gene expression. The present study investigated the effects of CLAs (cis‐9, trans‐11, and trans‐10, cis‐12 isomers and a 50:50 mixture) on apoptosis and NF‐κB activation in LNCaP cells.METHODSApoptosis was assessed by annexin V staining using flow cytometry. TNF‐α‐induced NF‐κB activity was determined by gel shift and reporter gene assays in addition to monitoring IκBα phosphorylation.RESULTSOnly the CLA cis‐9, trans‐11 isomer significantly increased TNF‐α‐induced apoptosis (by 59%), which correlated with a reduction in NF‐κB transcriptional activity (by 35%, P < 0.05), NF‐κB binding activity (by 15%, P < 0.05), and phosphorylation of IκBα (by 36%, P < 0.01).CONCLUSIONSOur results may offer a mechanistic explanation for the reported inhibition of prostate tumor growth by CLAs in animal models of disease. Prostate © 2006 Wiley‐Liss, Inc.
The prostate‐specific G‐protein coupled receptors PSGR and PSGR2 are prostate cancer biomarkers that are complementary to α‐methylacyl‐CoA racemase
Authors: Wang Jianghua , Weng Jinsheng , Cai Yi , Penland Rebecca , Liu Mingyao , Ittmann Michael 
Published: February 2006

AbstractBackgroundImmunohistochemistry (IHC) to detect α‐methylacyl‐CoA racemase (AMACR) expression can be useful in the diagnosis of small foci of prostate cancer on needle biopsy specimens, although it still has limitations in terms of both sensitivity and specificity. We have previously described the increased expression of two prostate‐specific G‐protein coupled receptors (PSGR and PSGR2) in human prostate cancer. To examine their potential usefulness as cancer biomarkers, we have evaluated their expression relative to AMACR in prostate cancer tissues.MethodsExpression of PSGR, PSGR2, and AMACR were examined by quantitative reverse‐transcriptase PCR in mRNAs from benign prostate and prostate cancer tissues. Expression of PSGR2 and AMACR was also examined by in situ hybridization using a prostate cancer tissue microarray.ResultsBy in situ hybridization, 24 of 40 prostate cancer cases showed concordant expression of PSGR2 and AMACR. However, in 16 cases there was significant discordance between expression levels of these two markers. By quantitative RT‐PCR all three markers were substantially increased in cancer, with AMACR the most overexpressed (30‐fold), followed by PSGR2 (13‐fold) and PSGR (10‐fold). AMACR was the best single marker of prostate cancer but in 7 of the 59 total cases the expression of AMACR was not significantly elevated while PSGR and/or PSGR2 were substantially elevated.ConclusionAll three biomarkers are increased in prostate cancer but their expression is not completely concordant. There is a subset of cases in which analysis of expression of PSGR and/or PSGR2, in addition to AMACR, would be diagnostically useful. Prostate © 2006 Wiley‐Liss, Inc.
Multiscale modeling of macromolecular conformational changes combining concepts from rigidity and elastic network theory
Authors: Ahmed Aqeel , Gohlke Holger 
Published: February 2006

AbstractThe development of a two‐step approach for multiscale modeling of macromolecular conformational changes is based on recent developments in rigidity and elastic network theory. In the first step, static properties of the macromolecule are determined by decomposing the molecule into rigid clusters by using the graph‐theoretical approach FIRST and an all‐atom representation of the protein. In this way, rigid clusters are not limited to consist of residues adjacent in sequence or secondary structure elements as in previous studies. Furthermore, flexible links between rigid clusters are identified and can be modeled as such subsequently. In the second step, dynamical properties of the molecule are revealed by the rotations‐translations of blocks approach (RTB) using an elastic network model representation of the coarse‐grained protein. In this step, only rigid body motions are allowed for rigid clusters, whereas links between them are treated as fully flexible. The approach was tested on a data set of 10 proteins that showed conformational changes on ligand binding. For efficiency, coarse‐graining the protein results in a remarkable reduction of memory requirements and computational times by factors of 9 and 27 on average and up to 25 and 125, respectively. For accuracy, directions and magnitudes of motions predicted by our approach agree well with experimentally determined ones, despite embracing in extreme cases >50% of the protein into one rigid cluster. In fact, the results of our method are in general comparable with when no or a uniform coarse‐graining is applied; and the results are superior if the movement is dominated by loop or fragment motions. This finding indicates that explicitly distinguishing between flexible and rigid regions is advantageous when using a simplified protein representation in the second step. Finally, motions of atoms in rigid clusters are also well predicted by our approach, which points to the need to consider mobile protein regions in addition to flexible ones when modeling correlated motions. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Discrimination of outer membrane proteins using machine learning algorithms
Authors: Gromiha M. Michael , Suwa Makiko 
Published: February 2006

AbstractDiscriminating outer membrane proteins (OMPs) from other folding types of globular and membrane proteins is an important task both for identifying OMPs from genomic sequences and for the successful prediction of their secondary and tertiary structures. In this work, we have analyzed the performance of different methods, based on Bayes rules, logistic functions, neural networks, support vector machines, decision trees, etc. for discriminating OMPs. We found that most of the machine learning techniques discriminate OMPs with similar accuracy. The neural network‐based method could discriminate the OMPs from other proteins [globular/transmembrane helical (TMH)] at the fivefold cross‐validation accuracy of 91.0% in a dataset of 1,088 proteins. The accuracy of discriminating globular proteins is 88.8% and that of TMH proteins is 93.7%. Further, the neural network method is tested with globular proteins belonging to 30 different folding types and it could successfully exclude 95% of the considered proteins. The proteins with SAM domain such as knottins, rubredoxin, and thioredoxin folds are eliminated with 100% accuracy. These accuracy levels are comparable to or better than other methods in the literature. We suggest that this method could be effectively used to discriminate OMPs and for detecting OMPs in genomic sequences. Proteins 2006. © 2006 Wiley‐Liss, Inc.
Fetal gender assignment by first‐trimester ultrasound
Authors: Efrat Z. , Perri T. , Ramati E. , Tugendreich D. , Meizner I. 
Published: February 2006

AbstractObjectiveUltrasound determination of fetal sex can benefit decision‐making regarding invasive prenatal testing in pregnancies at risk of sex‐linked genetic abnormalities. The aim of this study was to assess the accuracy of fetal sex determination by ultrasound at 12–14 weeks of gestation in a large cohort.MethodsFetal gender assessment by transabdominal ultrasound was performed in 656 singleton pregnancies at 12–14 weeks of gestation. The genital region was examined in the mid‐sagittal plane. The angle of the genital tubercle to a horizontal line through the lumbosacral skin surface was measured. The fetus was assigned male gender if the angle was > 30°, and female gender if the genital tubercle was parallel or convergent (<10°) to the horizontal line. At an intermediate angle of 10–30 degrees the gender was not determined. Crown–rump length (CRL) was measured in all cases.ResultsGender assignment was possible in 613 of the 656 (93%) fetuses. Gender identification according to CRL was feasible in 85%, 96% and 97% of the fetuses at gestational ages of 12 to 12 + 3, 12 + 4 to 12 + 6 and 13 to 13 + 6 weeks, respectively. Phenotypic sex was confirmed in 555 newborns. The accuracy of male gender assignment in this group was 99–100% at all ages, and that of female gender assignment was 91.5% at 12 to 12 + 3 weeks, 99% at 12 + 4 to 12 + 6 weeks and 100% at 13 to 13 + 6 weeks.ConclusionPrenatal gender assignment by ultrasound has a high accuracy rate at 12–14 weeks. These results indicate that invasive testing can probably be carried out in fetuses identified as males at this gestational age. However, in fetuses identified as female at a CRL of <62.6 mm, despite the relatively high 91.5% accuracy rate, the decision regarding invasive testing should be postponed until a higher CRL is achieved. Copyright © 2006 ISUOG. Published by John Wiley & Sons, Ltd.
The carboxyl‐terminal extension on fungal mitochondrial DNA polymerases: identification of a critical region of the enzyme from Saccharomyces cerevisiae
Authors: Young Matthew J. , Theriault Steven S. , Li Mingyi , Court Deborah A. 
Published: February 2006

AbstractFungal mitochondrial DNA (mtDNA) polymerases, in comparison to their metazoan counterparts, harbour unique carboxyl‐terminal extensions (CTEs) of varying lengths and unknown function. To determine the essential regions of the 279 residue CTE of the yeast enzyme (Mip1p), several CTE‐truncation variants were expressed in Saccharomyces cerevisiae. The respiratory competence of mip1Δ175 cells, in which Mip1p lacks the C‐terminal 175 residues, is indistinguishable from that of wild‐type. In contrast, strains harbouring Mip1pΔ351 and Mip1pΔ279 rapidly lose mtDNA. Approximately one in six mip1Δ216 transformants grew on glycerol, albeit poorly. Fluorescence microscopy and Southern blot analysis revealed lower levels of mtDNA in these cells, and the rapid loss of mtDNA during fermentative, but not respiratory, growth. Therefore, only the polymerase‐proximal segment of the Mip1p CTE is necessary for mitochondrial function. Comparison of this essential segment with the sequences of other fungal mtDNA polymerases revealed novel features shared among the mtDNA polymerases of the Saccharomycetales. Copyright © 2006 John Wiley & Sons, Ltd.
An XYZ Micromanipulator with three translational degrees of freedom
Authors: Jensen Kimberly A. , Lusk Craig P. , Howell Larry L. 
Published: February 2006

This paper introduces a three degree of freedom XYZ Micromanipulator (XYZM) that is fabricated in the $x$-$y$ plane and positions components in the $x$, $y$, and $z$ directions using three independent linear inputs. The mechanism positions components on a platform using three legs, each composed of a slider mechanism and a parallelogram mechanism.Three versions of the XYZM were fabricated and tested using surface micromachining processes: the rigid-body, offset, and compliant XYZM. Slider displacements of 45 micrometers result in a predicted out-of-plane displacement of 188 micrometers for the rigid-body XYZM, 205 micrometers for the offset XYZM, and 262 micrometers for the compliant XYZM.
Aminoguanidine prevents arterial stiffening and cardiac hypertrophy in streptozotocin‐induced diabetes in rats
Authors: Chang Kuo‐Chu , Hsu Kwan‐Lih , Tseng Chuen‐Den , Lin Yue‐Der , Cho Yi‐Li , Tseng Yung‐Zu 
Published: February 2006

The formation of advanced glycation endproducts (AGEs) on collagen within the arterial wall may be responsible for the development of diabetic vascular injury. This study was to examine the role of aminoguanidine (AG), an inhibitor of AGEs formation, in the prevention of arterial stiffening and cardiac hypertrophy in streptozotocin (STZ) induced diabetes in rats.
Diabetes was induced in animals by a single tail vein injection with 65 mg kg−1 STZ. After confirmation of the development of hyperglycemia (2 days later), rats were treated for 8 weeks with AG (daily peritoneal injections of 50 mg kg−1) and compared with the age‐matched untreated diabetic controls.
After exposure to AG, the STZ‐diabetic rats showed no alterations in cardiac output, aortic pressure profiles, total peripheral resistance, and aortic characteristic impedance.
By contrast, treatment of this experimental diabetes with AG resulted in a significant increase in wave transit time (τ), from 20.4±0.6 to 24.7±0.5 ms (P<0.05) and a decrease in wave reflection factor (Rf), from 0.78±0.04 to 0.53±0.02 (P<0.05). The decreased Rf associated with the increased τ suggest that AG may retard the diabetes‐induced augmentation in systolic load of the left ventricle coupled to its arterial system.
Meanwhile, the diminished ratio of left ventricular weight to body weight suggests that prevention of the diabetes‐related cardiac hypertrophy by AG may correspond to the drug‐induced decline in aortic stiffening.
Glycation‐derived modification on aortic collagen was also found to be enhanced in rats with diabetes (+65.3%, P<0.05) and the advanced glycation process was retarded by AG treatment.
We conclude that long‐term administration of AG to the STZ‐treated rats imparts significant protection against the diabetes‐derived deterioration in vascular dynamics, at least partly through inhibition of the AGEs accumulation on collagen in the arterial wall.

British Journal of Pharmacology (2006) 147, 944–950. doi:10.1038/sj.bjp.0706684
Co‐administration of glutathione and nitric oxide enhances insulin sensitivity in Wistar rats
Authors: Guarino Maria P , Macedo M Paula 
Published: February 2006

The liver modulates insulin sensitivity through a prandial‐dependent mechanism that requires activation of the hepatic parasympathetic nerves, hepatic nitric oxide (NO) and hepatic glutathione (GSH). We tested the hypothesis that co‐administration of GSH and NO to the liver enhances insulin sensitivity in a GSH and NO dose‐dependent manner.
24 h fasted Wistar rats were used. Hepatic GSH was supplemented by administration of glutathione monoethylester (GSH‐E; 0.1/0.25/0.5/1/2 mmol kg−1) and 3‐morpholinosidnonimine (SIN‐1; 5/10 mg kg−1) was used as a NO donor. The drugs were administered either systemically (i.v.) or intraportally (i.p.v.). Insulin sensitivity was assessed using a transient euglycemic clamp.
Neither GSH‐E nor SIN‐1 increased insulin sensitivity when administered alone, both i.v. and i.p.v. Moreover, changes in insulin sensitivity were not observed when GSH‐E was administered i.v. followed by either i.v. or i.p.v. SIN‐1 at any of the doses tested. However, i.p.v. administration of GSH‐E followed by i.p.v. SIN‐1 10 mg kg−1 significantly increased insulin sensitivity in a GSH‐E dose‐dependent manner: 26.1±9.4% after 0.1 mmol kg−1 GSH‐E; 44.6±7.9% after 0.25 mmol kg−1 GSH‐E; 59.4±15.1% after 0.5 mmol kg−1 GSH‐E; 138.9±12.7% after 1 mmol kg−1 GSH‐E and 117.3±29.2% after a dose of 2 mmol kg−1 (n=23, P<0.005).
Our results confirm that insulin sensitivity is enhanced in a dose‐dependent manner by co‐administration of NO and GSH donors to the liver.

British Journal of Pharmacology (2006) 147, 959–965. doi:10.1038/sj.bjp.0706691
Artifacts in 3D rotational angiography. an experimental study
Authors: Hagen G. , Lindgren P. G. , Jangland L. , Magnusson P. , Magnusson A. 
Published: February 2006

Purpose: To investigate artifacts in three‐dimensional rotational angiography (3D‐RA) in an experimental model and to evaluate which parameters influence their distribution. Material and Methods: 3D‐RA was carried out in a circular vessel phantom filled with contrast medium. Two different rotational angulations were used: 160° causing 64 images and 180° causing 90 or 120 images. The images were transferred to one workstation for reconstruction of axial slices and then to another workstation for 3D reconstructions. The 3D reconstructions were compared with standardized threshold settings. Results: The artifacts occurred where the vessel had a longer path parallel to the rotation plane and became increasingly pronounced when the threshold level was raised. The artifacts decreased in size when rotation angle and number of projections were increased. Conclusion: The quality of the 3D reconstructions from RA was degraded by beam‐hardening and sampling artifacts. The sampling artifacts were diminished by increasing both the rotation angle and the number of projections. The distortions in the 3D reconstructions caused by beam‐hardening remain to be resolved. The threshold values also had a considerable influence on the 3D reconstructions.
Magnetic resonance imaging of hyaline cartilage defects at 1.5T and 3.0T: comparison of medium T2‐weighted fast spin echo, T1‐weighted two‐dimensional and three‐dimensional gradient echo pulse sequences
Authors: Fischbach F. , Bruhn H. , Unterhauser F. , Ricke J. , Wieners G. , Felix R. , Weiler A. , Schröder R. J. 
Published: February 2006

Purpose: To evaluate and compare the diagnostic accuracy of appropriate magnetic resonance (MR) sequences in the detection of cartilage lesions at 1.5T and 3.0T. Material and Methods: Twelve chondral defects of varying depths, widths, and locations were created in the retropatellar hyaline cartilage in six sheep cadaver limbs. Axial images employing three fat‐suppressed imaging sequences – (1) a T2‐weighted fast spin‐echo (FSE) sequence, (2) a two‐dimensional (2D) and (3) three‐dimensional (3D) gradient‐echo (GE) sequence at 1.5T and 3.0T using an extremity quadrature coil – were evaluated by three experienced radiologists. Statistical analysis of the results consisted of receiver operating characteristics (ROC) and significant testing using the bivariate chi‐square test. In addition, signal‐to‐noise ratios (SNR) and contrast‐to‐noise ratios (CNR) were evaluated with significance testing using the Wilcoxon test. Results: The 3D GE sequence compared favorably with other sequences at 3.0T and 1.5T (Az = 0.88 at 3.0T and Az = 0.85 at 1.5T) missing only one small grade 2 lesion. 2D GE imaging was inferior to 3D imaging at both field strengths ( P<0.05) in general. However, compared to 1.5T, lesion detectability was improved at the higher magnetic field of 3.0T (Az = 0.81 and 0.73 at 3.0T and 1.5T, respectively). FSE images showed significantly inferior sensitivity and less anatomical detail compared to the GE sequences at both field strengths (Az = 0.64 and 0.72 at 3.0T and 1.5T, respectively; P<0.05). However, compared to 1.5T, lesion detectability SNR and CNR values were superior in all sequences tested at 3.0T. Conclusion: MRI at 3.0T improves SNR and CNR significantly in the most common sequences for cartilage MRI, resulting in an improvement in chondral lesion detection. GE imaging therefore allows resolution to be increased in an acceptable time manner for patient comfort, and the 3D GE fat‐suppressed sequence at 3.0T appears to be best suited for cartilage imaging in a clinical setting.
Diffusion tensor imaging of cerebral white matter in patients with myotonic dystrophy
Authors: Fukuda H. , Horiguchi J. , Ono C. , Ohshita T. , Takaba J. , Ito K. 
Published: February 2006

Purpose: To determine whether myotonic dystrophy (MyD) patients have diffusion tensor abnormalities suggestive of microstructural changes in normal‐appearing white matter (NAWM). Material and Methods: Conventional and diffusion tensor magnetic resonance images of the brain were obtained in 19 MyD patients and 19 age‐matched normal control subjects. Fractional anisotropy (FA) and mean diffusivity (MD) values were calculated in white matter lesions (WMLs) and NAWM in MyD patients and in the white matter of normal control subjects. Differences between WML and NAWM values and between MyD patient and control subject values were analyzed statistically. Results: Significantly lower FA and higher MD values were found in all regions of interest in the NAWM of MyD patients than in the white matter of control subjects ( P<0.01), as well as significantly lower FA and higher MD values in WMLs than in NAWM of MyD patients ( P<0.05). There was no significant correlation of mean FA or MD values in NAWM with patient age, age at onset, or duration of illness ( P>0.1). Conclusion: Diffusion tensor imaging analysis suggests the presence of diffuse microstructural changes in NAWM of MyD patients that may play an important role in the development of disability.