bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional Characterization of the Recombinant N‐Methyltransferase Domain from the Multienzyme Enniatin Synthetase
Authors: Hornbogen Till , Riechers Sean‐Patrick , Prinz Bianka , Schultchen Jeffrey , Lang Christine , Schmidt Sebastian , Mügge Clemens , Turkanovic Suada , Süssmuth Roderich D. , Tauberger Eva , Zocher Rainer 
Published: April 2007

AbstractA 51 kDa fusion protein incorporating the N‐methyltransferase domain of the multienzyme enniatin synthetase from Fusarium scirpi was expressed in Saccharomyces cerevisiae. The protein was purified and found to bind S‐adenosyl methionine (AdoMet) as demonstrated by cross‐linking experiments with 14C‐methyl‐AdoMet under UV irradiation. Cofactor binding at equilibrium conditions was followed by saturation transfer difference (STD) NMR spectroscopy, and the native conformation of the methyltransferase was assigned. STD NMR spectroscopy yielded significant signals for H2 and H8 of the adenine moiety, H1’ of D‐ribose, and SCH3 group of AdoMet. Methyl group transfer catalyzed by the enzyme was demonstrated by using aminoacyl‐N‐acetylcysteamine thioesters (aminoacyl‐SNACs) of L‐Val, L‐Ile, and L‐Leu, which mimic the natural substrate amino acids of enniatin synthetase presented by the enzyme bound 4′‐phosphopantetheine arm. In these experiments the enzyme was incubated in the presence of the corresponding aminoacyl‐SNAC and 14C‐methyl‐AdoMet for various lengths of time, for up to 30 min. N‐[14C‐Methyl]‐aminoacyl‐SNAC products were extracted with EtOAc and separated by TLC. Acid hydrolysis of the isolated labeled compounds yielded the corresponding N‐[14C‐methyl] amino acids. Further proof for the formation of N‐14C‐methyl‐aminoacyl‐SNACs came from MALDI‐TOF mass spectrometry which yielded 23 212 Da for N‐methyl‐valyl‐SNAC, accompanied by the expected postsource decay (PSD) pattern. Interestingly, L‐Phe, which is not a substrate amino acid of enniatin synthetase, also proved to be a methyl group acceptor. D‐Val was not accepted as a substrate; this indicates selectivity for the L isomer.
Effect of mammographic service screening on stage at presentation of breast cancers in Sweden
Authors:   Swedish Organised Service Screening Evaluation Group
Published: April 2007

AbstractBACKGROUNDPrevious results have shown a reduction in mortality with service screening in Sweden on the order of 40%. If the rate of tumors at a later stage were similarly reduced, this would give further support to the mortality findings.METHODSThe rates of lymph node‐positive cancers, of tumors >2 cm in pathological size, and of tumors of TNM stage II or worse before and after the introduction of screening were compared in 13 areas in Sweden, adjusted for changes in overall incidence during the period of study and stratified by age (40–49 and 50–69 years).RESULTSData were obtained on a total of 23,092 cancers and 10,177,113 person‐years of observation. In women exposed to screening in the screening epoch, there was a significant 45% reduction in tumors of size >2 cm compared with the prescreening (relative risk [RR] = 0.55, 95% confidence interval [CI]: 0.46–0.66) in the 40–49 age group, and a 33% reduction in the 50–69 group (RR = 0.67, 95% CI: 0.62–0.72). For lymph node‐positive and stage II+ disease, there were smaller but still significant reductions. No reduction in incidence in later‐stage disease was observed in the unexposed women in the screening epoch.CONCLUSIONSScreening has significantly and substantially reduced the rates of larger tumors and lymph node‐positive breast cancer in Sweden, and the magnitude of the reduction is consistent with the reduction in breast cancer mortality. Cancer 2007. © 2007 American Cancer Society.
Almost global existence for Hamiltonian semilinear Klein‐Gordon equations with small Cauchy data on Zoll manifolds
Authors: Bambusi D. , Delort J.‐M. , Grébert B. , Szeftel J. 
Published: April 2007

AbstractThis paper is devoted to the proof of almost global existence results for Klein‐Gordon equations on Zoll manifolds (e.g., spheres of arbitrary dimension) with Hamiltonian nonlinearities, when the Cauchy data are smooth and small. The proof relies on Birkhoff normal form methods and on the specific distribution of eigenvalues of the Laplacian perturbed by a potential on Zoll manifolds. © 2007 Wiley Periodicals, Inc.
Wave Propagation through sparse potential barriers
Authors: Denisov Sergey A. 
Published: April 2007

AbstractWe prove that the three‐dimensional Schrödinger operator with slowly decaying sparse potential has an a.c. spectrum that fills ℝ+. A new kind of WKB asymptotics for Green's function is obtained. The absence of positive eigenvalues is established as well. © 2007 Wiley Periodicals, Inc.
Fine structure of the zeros of orthogonal polynomials IV: A priori bounds and clock behavior
Authors: Last Yoram , Simon Barry 
Published: April 2007

AbstractWe prove locally uniform spacing for the zeros of orthogonal polynomials on the real line under weak conditions (Jacobi parameters approach the free ones and are of bounded variation). We prove that for ergodic discrete Schrödinger operators, Poisson behavior implies a positive Lyapunov exponent. Both results depend on a priori bounds on eigenvalue spacings for which we provide several proofs. © 2007 Wiley Periodicals, Inc.
Compactness along the branch of semistable and unstable solutions for an elliptic problem with a singular nonlinearity
Authors: Esposito Pierpaolo , Ghoussoub Nassif , Guo Yujin 
Published: April 2007

AbstractWe study the branch of semistable and unstable solutions (i.e., those whose Morse index is at most 1) of the Dirichlet boundary value problem − Δu = λf(x)/(1 − u)2 on a bounded domain Ω ⊂ ℝN, which models—among other things—a simple electrostatic microelectromechanical system (MEMS) device. We extend the results of 11 relating to the minimal branch, by obtaining compactness along unstable branches for 1 ≤ N ≤ 7 on any domain Ω and for a large class of “permittivity profiles” f. We also show the remarkable fact that powerlike profiles f(x) ≅ |x|α can push back the critical dimension N = 7 of this problem by establishing compactness for the semistable branch on the unit ball, also for N ≥ 8 and as long as

As a byproduct, we are able to follow the second branch of the bifurcation diagram and prove the existence of a second solution for λ in a natural range. In all these results, the conditions on the space dimension and on the power of the profile are essentially sharp. © 2007 Wiley Periodicals, Inc.
Initial stage of genetic mapping in Ciona intestinalis
Authors: Kano Shungo 
Published: April 2007

AbstractThe use of classic genetics is emerging in the ascidian Ciona intestinalis; recent advances in genomics and high‐quality developmental and evolutionary studies have made this animal an attractive model for research purposes. Genetic mapping in Ciona will likely make a major contribution to ascidian genomics and developmental biology by providing support for genome assembly and annotation and for the isolation of genes with particular mutations, while construction of genetic maps advances classic genetics in this species. Two major issues must be overcome before fine genetic maps can be constructed: the choice of proper genetic backgrounds and the establishment of laboratory strains. A high degree of polymorphism is useful for genetic mapping if we consider particular combinations of genetic backgrounds and techniques, although it is necessary to pay attention to the confused classification of C. intestinalis. Thus, it is preferred to establish laboratory strains instead of using samples with various genetic backgrounds. As these issues are unresolved, only amplified fragment length polymorphism–based maps have been created, while bulk segregant analysis is expected to isolate markers flanking mutant loci. However, rich genomic resources should facilitate the next stage of genetic map construction based on type I markers using coding sequences. The meiotic events that occur in crossing experiments for mapping purposes should shed light on population genetics and speciation issues. The results of such investigations may provide feedback for comparative genomics and developmental genetics in the near future. Developmental Dynamics 236:1768–1781, 2007. © 2007 Wiley‐Liss, Inc.
The DVE changes distal epiblast fate from definitive endoderm to neurectoderm by antagonizing nodal signaling
Authors: Miura Shigeto , Mishina Yuji 
Published: April 2007

AbstractTo assess the function of the distal visceral endoderm (DVE) of embryonic day 5.5 (E5.5) embryos, we established a system to directly ablate the DVE and observe the consequences after culture. When the DVE was successfully ablated, such embryos (DVE‐ablated embryos) showed deregulated expression of Nodal and Wnt3 and ectopically formed the primitive streak at the proximal portion of the embryo. The DVE and anterior visceral endoderm (AVE) are implicated in the development of neurectoderm. We found that the distal epiblast of E5.5 embryo rotates anteriorly by the beginning of gastrulation. These cells remained to be anteriorly located during gastrulation and contributed to the ectoderm in the anterior side of the embryo. This indicates that the distal epiblast of E5.5 embryo becomes neurectoderm in normal development. In DVE‐ablated embryos, the distal epiblast did not show any movement during culture and was abnormally fated to early definitive endoderm lineage. The data suggest that down‐regulation of Nodal signaling in the distal epiblast of E5.5 embryo may be an initial step of neural development. Developmental Dynamics 236:1602–1610, 2007. Published 2007 Wiley‐Liss, Inc.
Development of a new method for analysis of Sudan dyes by pressurized CEC with amperometric detection
Authors: Liu Shaofeng , Zhang Xue , Lin Xucong , Wu Xiaoping , Fu Fengfu , Xie Zenghong 
Published: April 2007

AbstractA new analytical method, pressurized CEC (pCEC) with amperometric detection (AD) using 1.5 μm RP nonporous silica packed columns has been developed for the rapid separation and determination of four Sudan dyes in hot chilli. The influence of several experimental parameters on the retention behavior has been investigated. The electrochemical oxidation of Sudans I–IV separated by pCEC can be reliably monitored with a carbon electrode at +0.95 V (vs. Ag/AgCl). Fast and efficient separation of the analytes was achieved within 7 min by pCEC under the optimum conditions with an ACN/water (95:5%) mobile phase containing formic acid (pH 4.3), 5% acetone and 0.002% triethylamine using a separation voltage of 12 kV. The detection limits for four Sudan dyes ranged from 8.0 × 10−7 to 1.2 × 10−6 mol/L. To evaluate the feasibility and reliability of this method, the proposed pCEC‐AD method was further demonstrated with hot chilli samples spiked with Sudan dyes.
Simultaneous determination of cefepime and vancomycin in plasma and cerebrospinal fluid by MEKC with direct sample injection and application for bacterial meningitis
Authors: Yang Yuan‐Han , Wu Wen‐Yi , Yeh Hsin‐Hua , Chen Su‐Hwei 
Published: April 2007

AbstractA simple MEKC with UV detection at 214 nm for simultaneous analysis of cefepime and vancomycin in plasma and in cerebrospinal fluid (CSF) by direct injection without any sample pretreatment is described. The separation of cefepime and vancomycin from biological matrices was performed at 25°C using a BGE consisting of a Tris buffer with SDS and methanol as the electrolyte solution. Under optimal MEKC conditions for biological samples, good separations with high efficiency and short analysis time are achieved. Several parameters affecting the separation of the drugs from biological matrices were studied, including methanol, pH, and concentrations of the Tris buffer and SDS. The linear ranges of the method for the determination of cefepime and vancomycin in plasma and in CSF using imidazole or cefazolin as an internal standard, respectively, were all over the range of 1–30 μg/mL; the detection limits of cefepime and vancomycin in biological matrices (injection 10 kV, 15 s) were 0.3 and 0.5 μg/mL, respectively. The applicability of the proposed method for the determination of cefepime and vancomycin in plasma and CSF collected after intravenous administration of the drugs in patients with meningitis was demonstrated.
Impact of phase and timing jitter on IFDMA systems
Authors: Simon E. , Legouable R. , Hélard M. , Liénard M. 
Published: April 2007

AbstractIn this paper, we investigate the sensitivity of Interleaved Frequency Division Multiple Access (IFDMA) systems to phase and timing jitter. With this aim, the theoretical expressions of the Signal to Interference plus Noise Ratio (SINR) degradation are derived at the decision device input in the presence of phase and timing jitter. The obtained degradation expressions can be evaluated by means of numerical integration. They are shown as a function of the load for various parameters of jitter model. Moreover, it is demonstrated that when assuming a full load, performance degradations do not depend on data block length, compression factor and jitter spectral content as long as the transmitted data block length is large enough. Furthermore, we investigate how the Nyquist filter rolloff impacts the performance degradation. Copyright © 2007 John Wiley & Sons, Ltd.
Constellation inference for polar LEO satellite networks by delay probing
Authors: Wang Junfeng , She Chundong , Liu Jin 
Published: April 2007

AbstractAs a key part of Next Generation Network (NGN) infrastructure, next generation satellite networks are expected to support a variety of applications with diverse performance requirements. This paper argues the necessities of developingbuilt‐inLow Earth Orbit (LEO) satellite constellation inference algorithms. Combined with thorough understanding of the characteristics of underlying satellite network and traffic dynamics, constellation inference is the preliminary step to provide Internet Service Providers (ISPs) an efficient way for network monitoring, system design, traffic engineering and performance promotion.To infer the constellation, adivide‐and‐conquermechanism is developed for each parameter estimation by delay probing carried out between two terminals located at the same geographic positions. Performance evaluation on several popular polar LEO constellations proves the accuracy and efficiency of the developed constellation measurement algorithms. The geographic position limitation of the delay probing terminals for a valid constellation inference is also analysed in the paper. Copyright © 2007 John Wiley & Sons, Ltd.
Intermediate frequency zero‐crossing detection of filtered MSK based on irregular sampling
Authors: Scholand Tobias , Jung Peter 
Published: April 2007

AbstractShort range communication systems such as Bluetooth and DECT (Digital Enhanced Cordless Telecommunications) deploy Gaussian frequency shift keying (GFSK), which is a continuous phase modulation (CPM) scheme derived from minimum shift keying (MSK). Since these short range communication systems require low‐cost transceiver structures, the development of appropriate receiver techniques has been a major research topic. Particularly, analogue limiter‐‐discriminator‐‐integrator (LDI) dump filtering techniques have received considerable attention. With the availability of digital signal processing (DSP), the digital implementation of LDI techniques has become increasingly attractive. In order to make LDI receivers more accessible, zero‐crossing detection was proposed. First, the authors shall focus on the establishment of an appropriate mathematical discrete‐time system model, taking bandlimiting receiver filters into account explicitly. This system model serves as the basis for the development of a multitude of digital zero‐crossing detection techniques. Starting from this mathematical discrete‐time system model, the authors shall focus on a novel, yet promising, approach to digital zero‐crossing detection in the intermediate frequency domain, using irregular sampling instead of the commonly employed regular sampling. The novel detectors shall be termed zero‐crossing decorrelation detectors (ZXDDs), because a decorrelating approach will be used. The authors shall present three different variants of the ZXDD. The performance of these ZXDD schemes has been analysed in simulations by the authors and obtained results shall be presented and compared to the performance of known LDI and zero‐crossing detection based techniques. Copyright © 2007 John Wiley & Sons, Ltd.
HPV related VIN: Highly proliferative and diminished responsiveness to extracellular signals
Authors: Santegoets Lindy A.M. , Seters Manon van , Helmerhorst Theo J.M. , Heijmans‐Antonissen Claudia , Hanifi‐Moghaddam Payman , Ewing Patricia C. , van IJcken Wilfred F.J. , van der Spek Peter J. , van der Meijden Willem I. , Blok Leen J. 
Published: April 2007

AbstractVulvar intraepithelial neoplasia (VIN) is a premalignant disorder caused by human papillomaviruses. Basic knowledge about the molecular pathogenesis of VIN is sparse. Therefore, we have analyzed the gene expression profile of 9 VIN samples in comparison to 10 control samples by using genome wide Affymetrix Human U133A plus2 GeneChips. Results were validated by quantitative real‐time RT‐PCR analysis and immunostaining of a few representative genes (TACSTD1, CCNE2, AR and ESR1). Significance analysis of microarrays (SAM) showed that 1,497 genes were differentially expressed in VIN compared to controls. By analyzing the biological processes affected by the observed differences, we found that VIN appears to be a highly proliferative disease; many cyclins (CCNA, CCNB and CCNE) and almost all prereplication complex proteins are upregulated. Thereby, VIN does not seem to depend for its proliferation on paracrine or endocrine signals. Many receptors (for example ESR1 and AR) and ligands are downregulated. Furthermore, although VIN is not an invasive disease, the inhibition of expression of a marked number of cell–cell adhesion molecules seems to indicate development towards invasion. Upon reviewing apoptosis and angiogenesis, it was observed that these processes have not become significantly disregulated in VIN. In conclusion: although VIN is still a premalignant disease, it already displays several hallmarks of cancer. © 2007 Wiley‐Liss, Inc.
Birth weight and the risk of testicular cancer: A meta‐analysis
Authors: Michos Athanasios , Xue Fei , Michels Karin B. 
Published: April 2007

AbstractThe high incidence of testicular cancer in young males indicates a potential role of events during early life. Birth weight has been identified as a factor possibly associated with the risk of cancers later in life. To investigate the association between birth weight and testicular cancer, we conducted a Systematic Review and Meta‐Analysis of published studies investigating the association between birth weight and testicular cancer. Data were combined using a fixed‐effects model. Thirteen epidemiologic studies, published between 1983 and 2004, were included in the analysis, encompassing 5,663 patients with testicular cancer. Men weighing less than 2,500 grams at birth had a higher risk for developing testicular cancer later in life than those with normal birth weight (2,500–4,000 g) (OR = 1.18; 95% confidence interval (CI) 1.01–1.38). A similar trend was found for men with a birth weight above 4,000 g, (OR = 1.12; 95% CI 1.02–1.22). When seminoma and nonseminoma testicular cancer cases were considered separately, low birth weight was a risk factor specifically for seminomas (OR = 1.44; 95% CI 1.11–1.88). A U‐shaped association was observed between birth weight and the risk for testicular cancer. The underlying biological mechanisms for this phenomenon remain to be elucidated. © 2007 Wiley‐Liss, Inc.
Surveillance for familial breast cancer: Differences in outcome according to BRCA mutation status
Authors: Moller Pal , Evans D. Gareth , Reis Marta M. , Gregory Helen , Anderson Elaine , Maehle Lovise , Lalloo Fiona , Howell Anthony , Apold Jaran , Clark Neal , Lucassen Anneke , Steel C. Michael 
Published: April 2007

AbstractWomen with a family history of breast cancer are commonly offered regular clinical or mammographic surveillance from age 30. Data on the efficacy of such programmes are limited. Clinical, pathological and outcome data were recorded on all breast and ovarian cancers diagnosed within familial breast cancer surveillance programmes at collaborating centers in Norway and the UK up to the end of 2005. These have been analyzed according to the mutation status of the affected women (BRCA1+ve, BRCA2+ve or mutation‐negative). Breast cancer was diagnosed in 442 patients subsequently followed for a total of 2095 years. Eighty‐nine (20%) had BRCA1 mutations, 35 (8%) BRCA2 mutations and in 318 (72%) no mutation could be detected (“mut neg”). Five‐year survival in BRCA1 was 73% compared to 96% in BRCA2 and 92% in mut neg (p = 0.000). Among BRCA1 mutation‐carriers, 5‐year survival was 67% for cases diagnosed as carcinoma in situ, 84% for node‐negative invasive cancers and 58% for those with nodal involvement (p > 0.05). For BRCA2 mutation‐carriers the corresponding figures were 100, 100 and 90% (p > 0.05), while for mut neg women they were 100, 97 and 71% (p = 0.03). Regular surveillance in women at increased familial risk of breast cancer is associated with a good outcome if they carry BRCA2 mutations or no detectable mutation. Carriers of BRCA1 mutations fare significantly worse, even when their tumors are diagnosed at an apparently early stage. The differences in outcome associated with different genetic causes of disease were associated with demonstrated differences in tumor biology. The findings demonstrate the outcome for genetically different breast cancers detected within a programme for early diagnosis and treatment, which is relevant to genetic counseling when women at risk have to chose between the options for preventing death from inherited breast cancer. © 2007 Wiley‐Liss, Inc.
Contribution of the alcohol dehydrogenase‐1B genotype and oral microorganisms to high salivary acetaldehyde concentrations in Japanese alcoholic men
Authors: Yokoyama Akira , Tsutsumi Eri , Imazeki Hiromi , Suwa Yoshihide , Nakamura Chizu , Yokoyama Tetsuji 
Published: April 2007

AbstractThe less‐active homozygous alcohol dehydrogenase‐1B (ADH1B*1/*1) and inactive heterozygous aldehyde dehydrogenase‐2 (ALDH2*1/*2) increase the risk of upper aerodigestive tract cancer (UADTC) in Japanese alcoholics. We evaluated associations between ADH1B/ALDH2 genotypes and the blood and salivary ethanol/acetaldehyde levels of 80 Japanese alcoholic men in the morning when they first visited our hospital after drinking the day before. Higher levels of ethanol persisted in the blood for longer periods in ADH1B*1/*1 carriers (n = 25) than in ADH1B*2 allele carriers after adjustment for the amount and time of the preceding alcohol consumption and body weight [median (25th–75th %): 20.5 mM (15.5–52.4) vs. below detection level (<DL) (<DL‐6.4), p = 0.0003]. The ethanol levels in blood and saliva were similar, but the acetaldehyde levels in saliva were strikingly higher than in the blood, and were higher in ADH1B*1/*1 carriers than in ADH1B*2 allele carriers [47.4 μM (22.2–87.6) vs. 1.60 (<DL‐26.3) in the saliva, p = 0.009]. The salivary acetaldehyde levels were correlated with salivary acetaldehyde production (r = 0.34, p = 0.002). The oral bacteria and yeast counts were correlated with salivary acetaldehyde production. Both the microorganisms counts and acetaldehyde production decreased after 3 weeks of abstinence, and the decreases were correlated (r = 0.35, p = 0.042). No effect of inactive ALDH2 (n = 12) on ethanol lingering the next morning was observed. In conclusion, the high salivary acetaldehyde levels in the alcoholics were partly attributable to prolonged ethanol exposure because of the less‐active ADH1B and increased salivary acetaldehyde production as a result of oral microorganism overgrowth, and may explain their high risk for UADTC. © 2007 Wiley‐Liss, Inc.