bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Li2CO3 addition on the dielectric and piezoelectric responses in the low-temperature sintered 0.5PZN–0.5PZT systems
Authors: Hou Yu-Dong , Chang Li-Min , Zhu Man-Kang , Song Xue-Mei , Yan Hui
Published: October 2007

Low-temperature sintering of 0.5Pb(Zn1∕3Nb2∕3)O3–0.5Pb(Zr0.47Ti0.53)O3 ceramics (0.5PZN–0.5PZT) was investigated using Li2CO3 as sintering aids. The addition of Li2CO3 significantly improved the sinterability of 0.5PZN–0.5PZT ceramics, resulting in a reduction of sintering temperature from 1100to950°C. Moreover, the effect of Li2CO3 addition on the dielectric and piezoelectric responses in 0.5PZN–0.5PZT systems was systematically studied in this work. The analysis of x-ray diffraction patterns and scanning electron microscopy indicated that the solubility limit of Li ions in perovskite structures was near 0.5wt% in Li2CO3 form. Below the solubility limit, Li+ ions entered the six-fold coordinated B sites of oxygenic octahedral center and enhanced the compositional fluctuation in nanoscale, resulting in the increase of the degree of diffuseness γ. While at high doping level above the solubility limit, γ decreased subsequently, which was attributed to the formation of pyrochlore phase. Raman analysis on the B-site cation order correlates well with the dielectric measurement results. The large improvements in the piezoelectric properties such as the coupling factor and piezoelectric constant were also observed for doped specimens. Optimized parameters, such as d33=278pC∕N, kp=0.50, and εmax=8800, were achieved by doping 0.5wt% Li2CO3 in low-temperature sintered 0.5PZN–0.5PZT systems, which shows great promise as practical materials for multilayered piezoelectric device applications. The observed improvement in the electric properties can be attributed to the grain size effect. After doping, the clamping effect caused by oxygen vacancies and grain boundary phases on domain wall motion was largely reduced due to the increase of grain size; therefore, a significant reduced coercive field and an increased remanent polarization were observed in doped 0.5PZN–0.5PZT systems.
A modified sol-gel process for multiferroic nanocomposite films
Authors: Liu Ming , Li Xin , Lou Jing , Zheng Shijian , Du Kui , Sun Nian X.
Published: October 2007

Multiferroic CoFe2O4–Pb(Zr,Ti)O3 (CFO-PZT) composite films with nanoscale mixture of the two phases were prepared by a modified sol-gel process, in which a mixed precursor solution of both CFO and PZT was used. X-ray diffraction and transmission electron microscopy examinations revealed the coexistence of perovskite PZT and spinel CFO that were mixed in nanoscale with mean grain sizes of 5–10nm. Magnetic properties of the CFO-PZT nanocomposite were examined, which were consistent with their microstructures. The magnetoelectric coupling between CFO and PZT was demonstrated by an external magnetic field induced electric polarization change. This modified sol-gel processing provides an alternative for multiferroic composite films, which is simpler and easier to control compared to the conventional layer-layer sol-gel process for multiferroic composite films.
Anomalous voltage dependence of tunnel magnetoresistance in (Zn, Co)O-based junction with double barrier
Authors: Song C. , Yang Y. C. , Li X. W. , Liu X. J. , Zeng F. , Pan F.
Published: October 2007

Voltage dependent tunnel magnetoresistance (TMR) has been studied in fully epitaxial (Zn,Co)O∕ZnO∕(Zn,Co)O∕ZnO∕(Zn,Co)O magnetic tunnel junctions (MTJs) with double barrier. The MTJs show extremely small voltage dependence with “half voltage” over 4V above 6K. At 5K, the TMR as a function of voltage is found to be constant up to 2V, and then decreases. “TMR transition” occurs when temperature decreases to 3–4K, and subsequently, the TMR abnormally increases with voltage at 2K. The anomalous voltage dependent TMR is discussed in terms of the large energy separation between the Fermi level and the mobility edge.
SiGe growth on patterned Si(001) substrates: Surface evolution and evidence of modified island coarsening
Authors: Zhang J. J. , Stoffel M. , Rastelli A. , Schmidt O. G. , Jovanović V. , Nanver L. K. , Bauer G.
Published: October 2007

The morphological evolution of both pits and SiGe islands on patterned Si(001) substrates is investigated. With increasing Si buffer layer thickness the patterned holes transform into multifaceted pits before evolving into inverted truncated pyramids. SiGe island formation and evolution are studied by systematically varying the Ge coverage and pit spacing and quantitative data on the influence of the pattern periodicity on the SiGe island volume are presented. The presence of pits allows the fabrication of uniform island arrays with any of their equilibrium shapes.
Astrometric Observations of Wide Southern Double Stars – II
Authors: Bauer Christina , White Graeme L. , Blank David L. , Hons Alex , Jones Paul A.
Published: October 2007

Astrometric CCD observations have been made of wide (∼3 to 60 arcsec) southern double stars selected from the Washington Double Star catalogue (WDS). Southern double stars have not been well studied in the past; typically they had not been measured since about 1930, and ∼50% of them have been observed only once before our observations. Of the pairs measured ∼80% show no evidence of motion since the last observation. This is Paper II in which we present the observations of 290 WDS stars in the approximate RA range 17h 13m to 07h 30m and in the declination range −70° to −60°. We suggest 412 companions for these 290 stars and list 29 (10%) pairs that have shown significant motion.
Digital holographic microscopy reveals prey-induced changes in swimming behavior of predatory dinoflagellates
Authors: Sheng Jian , Malkiel Edwin , Katz Joseph , Adolf Jason , Belas Robert , Place Allen R.
Published: October 2007

The shallow depth of field of conventional microscopy hampers analyses of 3D swimming behavior of fast dinoflagellates, whose motility influences macroassemblages of these cells into often-observed dense “blooms.” The present analysis of cinematic digital holographic microscopy data enables simultaneous tracking and characterization of swimming of thousands of cells within dense suspensions. We focus on
Karlodinium veneficum
and
Pfiesteria piscicida
, mixotrophic and heterotrophic dinoflagellates, respectively, and their preys. Nearest-neighbor distance analysis shows that predator and prey cells are randomly distributed relative to themselves, but, in mixed culture, each predator clusters around its respective prey. Both dinoflagellate species exhibit complex highly variable swimming behavior as characterized by radius and pitch of helical swimming trajectories and by translational and angular velocity.
K. veneficum
moves in both left- and right-hand helices, whereas
P. piscicida
swims only in right-hand helices. When presented with its prey (
Storeatula major
), the slower
K. veneficum
reduces its velocity, radius, and pitch but increases its angular velocity, changes that reduce its hydrodynamic signature while still scanning its environment as “a spinning antenna.” Conversely, the faster
P. piscicida
increases its speed, radius, and angular velocity but slightly reduces its pitch when exposed to prey (
Rhodomonas
sp.), suggesting the preferred predation tactics of an “active hunter.”
Probing polyproline structure and dynamics by photoinduced electron transfer provides evidence for deviations from a regular polyproline type II helix
Authors: Doose Sören , Neuweiler Hannes , Barsch Hannes , Sauer Markus
Published: October 2007

Polyprolines are well known for adopting a regular polyproline type II helix in aqueous solution, rendering them a popular standard as molecular ruler in structural molecular biology. However, single-molecule spectroscopy studies based on Förster resonance energy transfer (FRET) have revealed deviations of experimentally observed end-to-end distances of polyprolines from theoretical predictions, and it was proposed that the discrepancy resulted from dynamic flexibility of the polyproline helix. Here, we probe end-to-end distances and conformational dynamics of poly-
l
-prolines with 1–10 residues using fluorescence quenching by photoinduced-electron transfer (PET). A single fluorophore and a tryptophan residue, introduced at the termini of polyproline peptides, serve as sensitive probes for distance changes on the subnanometer length scale. Using a combination of ensemble fluorescence and fluorescence correlation spectroscopy, we demonstrate that polyproline samples exhibit static structural heterogeneity with subpopulations of distinct end-to-end distances that do not interconvert on time scales from nano- to milliseconds. By observing prolyl isomerization through changes in PET quenching interactions, we provide experimental evidence that the observed heterogeneity can be explained by interspersed cis isomers. Computer simulations elucidate the influence of trans/cis isomerization on polyproline structures in terms of end-to-end distance and provide a structural justification for the experimentally observed effects. Our results demonstrate that structural heterogeneity inherent in polyprolines, which to date are commonly applied as a molecular ruler, disqualifies them as appropriate tool for an accurate determination of absolute distances at a molecular scale.
Leptin activates hypothalamic acetyl-CoA carboxylase to inhibit food intake
Authors: Gao Su , Kinzig Kimberly P. , Aja Susan , Scott Karen A. , Keung Wendy , Kelly Sandra , Strynadka Ken , Chohnan Shigeru , Smith Wanli W. , Tamashiro Kellie L. K. , Ladenheim Ellen E. , Ronnett Gabriele V. , Tu Yajun , Birnbaum Morris J. , Lopaschuk Gary D. , Moran Timothy H.
Published: October 2007

Hypothalamic fatty acid metabolism has recently been implicated in the controls of food intake and energy homeostasis. We report that intracerebroventricular (ICV) injection of leptin, concomitant with inhibiting AMP-activated kinase (AMPK), activates acetyl-CoA carboxylase (ACC), the key regulatory enzyme in fatty acid biosynthesis, in the arcuate nucleus (Arc) and paraventricular nucleus (PVN) in the hypothalamus. Arc overexpression of constitutively active AMPK prevents the Arc ACC activation in response to ICV leptin, supporting the hypothesis that AMPK lies upstream of ACC in leptin's Arc intracellular signaling pathway. Inhibiting hypothalamic ACC with 5-tetradecyloxy-2-furoic acid, a specific ACC inhibitor, blocks leptin-mediated decreases in food intake, body weight, and mRNA level of the orexigenic neuropeptide NPY. These results show that hypothalamic ACC activation makes an important contribution to leptin's anorectic effects. Furthermore, we find that ICV leptin up-regulates the level of malonyl-CoA (the intermediate of fatty acid biosynthesis) specifically in the Arc and increases the level of palmitoyl-CoA (a major product of fatty acid biosynthesis) specifically in the PVN. The rises of both levels are blocked by 5-tetradecyloxy-2-furoic acid along with the blockade of leptin-mediated hypophagia. These data suggest malonyl-CoA as a downstream mediator of ACC in leptin's signaling pathway in the Arc and imply that palmitoyl-CoA, instead of malonyl-CoA, could be an effector in relaying ACC signaling in the PVN. Together, these findings highlight site-specific impacts of hypothalamic ACC activation in leptin's anorectic signaling cascade.
On boundedness of solutions of reaction-diffusion equations with nonlinear boundary conditions
Authors: Arrieta José
Published: October 2007

We give conditions on the nonlinearities of a reaction-diffusion equation with nonlinear boundary conditions that guarantee that any solution starting at bounded initial data is bounded locally around a certain point

x
0

x_0

of the boundary, uniformly for all positive time. The conditions imposed are of a local nature and need only to hold in a small neighborhood of the point

x
0

x_0

.
Bounds of divided universal Bernoulli numbers and universal Kummer congruences
Authors: Adelberg Arnold , Hong Shaofang , Ren Wenli
Published: October 2007

Let

p
p

be a prime. We obtain good bounds for the

p
p

-adic sizes of the coefficients of the divided universal Bernoulli number

B
^

n

n

\tfrac {\hat {B}_n}{n}

when

n
n

is divisible by

p
−
1

p-1

. As an application, we give a simple proof of Clarke’s 1989 universal von Staudt theorem. We also establish the universal Kummer congruences modulo

p
p

for the divided universal Bernoulli numbers for the case

(
p
−
1
)

|

n

(p-1)|n

, which is a new result.
Billingsley’s packing dimension
Authors: Das Manav
Published: October 2007

For a stochastic process on a finite state space, we define the notion of a packing measure based on the naturally defined cylinder sets. For any two measures

ν
\nu

,

γ
\gamma

, corresponding to the same stochastic process, if
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper F subset-of-or-equal-to StartSet omega element-of normal upper Omega colon limit Underscript n Endscripts StartFraction log gamma left-parenthesis c Subscript n Baseline left-parenthesis omega right-parenthesis right-parenthesis Over log nu left-parenthesis c Subscript n Baseline left-parenthesis omega right-parenthesis right-parenthesis EndFraction equals theta EndSet comma">

F
⊆

{
ω
∈
Ω
:

lim

n

log
⁡
γ
(

c

n

(
ω
)
)

log
⁡
ν
(

c

n

(
ω
)
)

=
θ
}

,

F \subseteq \left \{ \omega \in \Omega : \lim _{n} \frac {\log \gamma (c_{n}(\omega ))}{\log \nu (c_{n}(\omega ))} = \theta \right \},

\]
then we prove that
\[

D
i
m

ν

(
F
)
=
θ
 

D
i
m

γ

(
F
)
.

{\rm {Dim}}_{\nu }(F) = \theta ~{\rm {Dim}}_{\gamma }(F).

\]
Convolution and restriction estimates for measures on curves in ℝ²
Authors: Oberlin Daniel
Published: October 2007

We study convolution and Fourier restriction estimates for some degenerate curves in

R

2

\mathbb R ^2

.
Complex Monge-Ampère of a maximum
Authors: Bedford Eric , Ma‘u Sione
Published: October 2007

We derive a formula for

(
d

d

c

u

)

n

(dd^{c}u)^{n}

where

u
=

max

j

u

j

u=\max _{j}u_{j}

is a finite maximum. As an application, we compute the complex equilibrium measures of some generalized polyhedra.
On diophantine approximation along algebraic curves
Authors: Burger Edward , Pillai Ashok
Published: October 2007

LetF(x,y)∈Z[x,y]F(x,y)\in \mathbb {Z}[x,y]be a quadratic form such that the associated algebraic curveC:F(x,y)=1\mathcal {C} : F(x,y)=1contains a rational point. Here we show that there exists a domainD⊆R\mathcal {D} \subseteq \mathbb {R}such that for almost allξ∈D\xi \in \mathcal {D}, there exists an infinite sequence of nonzero integer triples(xn,yn,zn)(x_{n},y_{n},z_{n})satisfying the following two properties: (i) For eachnn,xn/ynx_{n}/y_{n}is an excellent rational approximation toξ\xi, in the sense thatlimn→∞|ξyn−xn|=0 ;\begin{equation*} \lim _{n\rightarrow \infty }| \xi y_{n}-x_{n}|=0\ ; \end{equation*}and (ii)(xn/zn,yn/zn)(x_{n}/z_{n},y_{n}/z_{n})is a rational point on the curveC\mathcal {C}. In addition, we give explicit values ofξ\xifor which both (i) and (ii) hold, and produce a similar result for a certain class of cubic curves.
Expansion of the Nucleoplasmic Reticulum Requires the Coordinated Activity of Lamins and CTP:Phosphocholine Cytidylyltransferase α
Authors: Gehrig Karsten , Cornell Rosemary B. , Ridgway Neale D.
Published: October 2007

The nucleoplasmic reticulum (NR), a nuclear membrane network implicated in signaling and transport, is formed by the biosynthetic and membrane curvature-inducing properties of the rate-limiting enzyme in phosphatidylcholine synthesis, CTP:phosphocholine cytidylyltransferase (CCT) α. The NR is formed by invagination of the nuclear envelope and has an underlying lamina that may contribute to membrane tubule formation or stability. In this study we investigated the role of lamins A and B in NR formation in response to expression and activation of endogenous and fluorescent protein-tagged CCTα. Similarly to endogenous CCTα, CCT-green fluorescent protein (GFP) reversibly translocated to nuclear tubules projecting from the NE in response to oleate, a lipid promoter of CCT membrane binding. Coexpression and RNA interference experiments revealed that both CCTα and lamin A and B were necessary for NR proliferation. Expression of CCT-GFP mutants with compromised membrane-binding affinity produced fewer nuclear tubules, indicating that the membrane-binding function of CCTα promotes the expansion of the NR. Proliferation of atypical bundles of nuclear membrane tubules by a CCTα mutant that constitutively associated with membranes revealed that expansion of the double-bilayer NR requires the coordinated assembly of an underlying lamin scaffold and induction of membrane curvature by CCTα.
Quaternary Structure of the Mitochondrial TIM23 Complex Reveals Dynamic Association between Tim23p and Other Subunits
Authors: Alder Nathan N. , Sutherland Jennifer , Buhring Ashley I. , Jensen Robert E. , Johnson Arthur E.
Published: October 2007

Tim23p is an essential channel-forming component of the multisubunit TIM23 complex of the mitochondrial inner membrane that mediates protein import. Radiolabeled Tim23p monocysteine mutants were imported in vitro, incorporated into functional TIM23 complexes, and subjected to chemical cross-linking. Three regions of proximity between Tim23p and other subunits of the TIM23 complex were identified: Tim17p and the first transmembrane segment of Tim23p; Tim50p and the C-terminal end of the Tim23p hydrophilic region; and the entire hydrophilic domains of Tim23p molecules. These regions of proximity reversibly change in response to changes in membrane potential across the inner membrane and also when a translocating substrate is trapped in the TIM23 complex. These structural changes reveal that the macromolecular arrangement within the TIM23 complex is dynamic and varies with the physiological state of the mitochondrion.
Distinct Pathways for the Early Recruitment of Myosin II and Actin to the Cytokinetic Furrow
Authors: Zhou Mian , Wang Yu-Li
Published: October 2007

Equatorial organization of myosin II and actin has been recognized as a universal event in cytokinesis of animal cells. Current models for the formation of equatorial cortex favor either directional cortical transport toward the equator or localized de novo assembly. However, this process has never been analyzed directly in dividing mammalian cells at a high resolution. Here we applied total internal reflection fluorescence microscope (TIRF-M), coupled with spatial temporal image correlation spectroscopy (STICS) and a new analytical approach termed temporal differential microscopy (TDM), to image the dynamics of myosin II and actin during the assembly of equatorial cortex. Our results indicated distinct and at least partially independent mechanisms for the early equatorial recruitment of myosin and actin filaments. Cortical myosin showed no detectable directional flow during early cytokinesis. In addition to equatorial assembly, we showed that localized inhibition of disassembly contributed to the formation of the equatorial myosin band. In contrast to myosin, actin filaments underwent a striking flux toward the equator. Myosin motor activity was required for the actin flux, but not for actin concentration in the furrow, suggesting that there was a flux-independent, de novo mechanism for actin recruitment along the equator. Our results indicate that cytokinesis involves signals that regulate both assembly and disassembly activities and argue against mechanisms that are coupled to global cortical movements.
Boosting multiclass learning with repeating codes and weak detectors for protein subcellular localization
Authors: Lin Chung-Chih , Tsai Yuh-Show , Lin Yu-Shi , Chiu Tai-Yu , Hsiung Chia-Cheng , Lee May-I. , Simpson Jeremy C. , Hsu Chun-Nan
Published: October 2007

Motivation: Determining locations of protein expression is essential to understand protein function. Advances in green fluorescence protein (GFP) fusion proteins and automated fluorescence microscopy allow for rapid acquisition of large collections of protein localization images. Recognition of these cell images requires an automated image analysis system. Approaches taken by previous work concentrated on designing a set of optimal features and then applying standard machine-learning algorithms. In fact, trends of recent advances in machine learning and computer vision can be applied to improve the performance. One trend is the advances in multiclass learning with error-correcting output codes (ECOC). Another trend is the use of a large number of weak detectors with boosting for detecting objects in images of real-world scenes.

Results: We take advantage of these advances to propose a new learning algorithm, AdaBoost.ERC, coupled with weak and strong detectors, to improve the performance of automatic recognition of protein subcellular locations in cell images. We prepared two image data sets of CHO and Vero cells and downloaded a HeLa cell image data set in the public domain to evaluate our new method. We show that AdaBoost.ERC outperforms other AdaBoost extensions. We demonstrate the benefit of weak detectors by showing significant performance improvements over classifiers using only strong detectors. We also empirically test our method's capability of generalizing to heterogeneous image collections. Compared with previous work, our method performs reasonably well for the HeLa cell images.

Availability: CHO and Vero cell images, their corresponding feature sets (SSLF and WSLF), our new learning algorithm, AdaBoost.ERC, and Supplementary Material are available at http://aiia.iis.sinica.edu.tw/

Contact:  chunnan@iis.sinica.edu.tw

Supplementary information: Supplementary data are available at Bioinformatics online.
Telling time from fossils: a phylogeny‐based approach to chronological ordering of paleobiotas
Authors: Makovicky Peter J.
Published: October 2007

The potential for using fossils for temporal ordering of sedimentary rocks is as old as historical geology itself. In spite of this, however, most current biostratigraphic and biochronologic techniques do not make use of phylogenetic information, but rely instead on some measure of species' presence or absence or their turnover in the fossil record. A common phylogenetic approach to biochronology has been to use “stage of evolution” arguments, whereas more rigorous, cladogram‐based methods have been proposed but have seen little use. Cladistic biochronologic analysis (CBA) is developed here as a new method for determining biochronologic order between paleobiotas based on the phylogenetic relationships of their constituent taxa. CBA is adapted from Brooks' parsimony analysis, and analyzes syntaxon information from clades that transcend a number of paleobiotas to determine relative temporal order among these paleobiotas. Because CBA is based on phylogenetic information, it is suited to problems where a good fossil record is available, but where stratigraphic or chronologic relationships are poorly constrained, such as the terrestrial vertebrate record. A practical example, based on the Cenozoic fossil record of North America, pits CBA against a test case in which the correct temporal order of biotas is known beforehand. The method successfully recovers correct temporal order between paleobiotas with reasonable levels of support, and is also shown to outperform a previously proposed cladistic biochronologic method. In a second example, CBA is used to achieve the first empirical temporal ordination for several Late Cretaceous localities in the Gobi Desert that produce fossils crucial to the understanding of modern amniote clades, but which have poorly resolved temporal relationships. CBA is sensitive to large amounts of extinction and poor sampling of the fossil record, but problems such as gaps in the fossil record (Lazarus taxa) can be dealt with efficiently through a number of a priori and a posteriori scoring techniques. CBA offers a novel approach for biochronologic analysis that is independent of, but complementary to and readily combinable with other chronologic/stratigraphic methods.

© The Willi Hennig Society 2007.
Assessment of endothelial function: comparison of the pulse wave response to β2‐adrenoceptor stimulation with flow mediated dilatation
Authors: Rambaran Curtis , Jiang Benyu , Ritter James M. , Shah Ajay , Kalra Lalit , Chowienczyk Philip J.
Published: October 2007

Aims

To assess the reproducibility of the digital pulse wave response to β2‐adrenoreceptor stimulation and to determine if an attenuated response to β2‐adrenoceptor stimulation is associated with impaired flow mediated dilatation (FMD).

Methods

Subjects (n = 20) with endothelial dysfunction (ED), were compared with healthy control subjects (n = 20). Change in reflection index (ΔRI) of the digital volume pulse in response to salbutamol (SALB, 5 µg min−1 i.v) and to nitroglycerin (NTG, 5 µg min−1 i.v) was used to assess endothelium‐dependent (ΔRISALB) and endothelium‐independent (ΔRINTG) pressure wave reflection. ΔRISALB was assessed on two occasions to examine reproducibility. High resolution ultrasound of the brachial artery was used to measure FMD and also dilation to NTG (NTGD).

Results

The mean difference in ΔRISALB between two visits was −0.2%, with SD of the difference 4.9%. Both ΔRISALB and FMD were impaired in subjects with ED compared with values in control subjects (5.0 ± 0.7 vs. 11.3 ± 1.2%, mean values ± SEM, P < 0.01 and 4.2 ± 0.6 vs. 7.5 ± 0.8%, P < 0.02 for ΔRISALB and FMD, respectively), whereas ΔRINTG and NTGD were similar in the two groups. ΔRISALB was correlated with FMD (r = 0.44, P < 0.01) and had 88% sensitivity and 79% specificity to detect abnormal (FMD < 4%).

Conclusions

The pulse wave response to a β2‐adrenoceptor agonist correlates with FMD and has high sensitivity and specificity in detecting abnormal endothelial function as defined by FMD. However, FMD is the preferred test to detect effects of interventions on endothelial function.
Effect of food or antacid on pharmacokinetics and pharmacodynamics of febuxostat in healthy subjects
Authors: Khosravan Reza , Grabowski Brian , Wu Jing‐Tao , Joseph‐Ridge Nancy , Vernillet Laurent
Published: October 2007

What is already known about this subject

• Febuxostat is a novel nonpurine selective inhibitor of xanthine oxidase.

What this study adds

• This is the first manuscript to address the effect of food and antacid on the pharmacokinetics and/or pharmacodynamics of febuxostat.

• The study will determine whether the drug can be administered regardless of food or antacid.

• It will therefore influence how the drug should be administered.

Aims

To evaluate the effects of food or antacid on the pharmacokinetics and/or pharmacodynamics of febuxostat.

Methods

Four Phase I, two‐period, crossover studies were performed in healthy male and female subjects. Subjects either received single 40‐mg (n = 24), multiple 80‐mg (n = 24) and single 120‐mg (n = 20) doses of febuxostat in fasting and nonfasting conditions, or received single 80‐mg (n = 24) doses alone or with antacid.

Results

Food caused a decrease in Cmax (38–49%) and AUC (16–19%) of febuxostat at different dose levels following single or multiple oral dosing with febuxostat. However, a slightly greater percent decrease in serum uric acid concentrations (58% vs. 51%) after multiple dosing with 80 mg of febuxostat under nonfasting conditions was observed, which was statistically (P < 0.05) but not clinically significant. Antacid caused a decrease in Cmax (32%), but had no effect on AUC of febuxostat. Febuxostat was safe and well tolerated in all studies.

Conclusions

Even though food caused a decrease in the rate and extent of absorption of febuxostat, this decrease was not associated with a clinically significant change in febuxostat pharmacodynamic effect. Despite a decrease in the absorption rate of febuxostat, antacid had no effect on the extent of febuxostat absorption. Therefore, febuxostat can be administered regardless of food or antacid intake.
Urothelial carcinomas arising in arsenic‐contaminated areas are associated with hypermethylation of the gene promoter of the death‐associated protein kinase
Authors: Chen W‐T , Hung W‐C , Kang W‐Y , Huang Y‐C , Chai C‐Y
Published: October 2007

Aims:  The mechanisms of urothelial carcinogenesis in areas highly contaminated with arsenic remain unclear. The aim was to determine whether hypermethylation of death‐associated protein kinase (DAPK) gene is associated with chronic arsenic exposure.

Methods and results:  The frequency of aberrant promoter methylation of DAPK in 17 urothelial carcinomas from an arsenic‐contaminated area and 21 urothelial carcinomas from a non‐arsenic‐contaminated area was determined by methylation‐specific polymerase chain reaction. DAPK hypermethylation status was significantly higher in urothelial cancers arising in arsenic‐contaminated areas when compared with tumours from patients from non‐contaminated areas (P = 0.018). In the subset of patients from living environments which were contaminated with arsenic, there was a statistically significant association between DAPK hypermethylation and patient’s age, tumour invasiveness, histological grade and recurrence. This was not seen for urothelial carcinoma from patients from non‐contaminated areas. A close correlation was also found between DAPK promoter methylation and low‐intensity DAPK expression, as detected by immunohistochemistry (P = 0.037).

Conclusion:  Exposure to arsenic may induce DAPK promoter hypermethylation and inactivate the function of DAPK in urothelial carcinoma. This could prove to be a key molecular event contributing to the malignant phenotype of tumour arising in patients from arsenic‐contaminated environments.
Partial susceptibility of the SSN‐1 fish cell line to a crustacean virus: a defective replication study
Authors: Hernandez‐Herrera R I , Chappe‐Bonnichon V , Roch P , Sri Widada J , Bonami J‐R
Published: October 2007

This study evaluated the possible use of the fish SSN‐1 cell line to investigate the development of Macrobrachium rosenbergii nodavirus (MrNV). Cells were incubated with viral particles and cytopathic effects were observed. De novo synthesis of viral capsid proteins was shown by immuno‐fluorescence labelling and a sandwich ELISA test. Viral genomic replication was demonstrated by RT‐PCR using primers specific to RNA‐1 as well as by quantitative RT‐PCR (RT‐qPCR). Using electron microscopy, only a few empty particles were observed and attempts to isolate complete infectious particles or to re‐infect healthy cells (second passage) were unsuccessful. As complete viral particles were rarely observed, it appeared that defaults in MrNV virogenesis might arise resulting in the formation of scarce and non‐infectious particles. SSN‐1 cells were found to be partially permissive to MrNV infection that induced cell lysis, but key elements for viral infection were lacking such as regulatory factors for gene replication or post‐translational modifications.
Expression and serological application of a capsid protein of an iridovirus isolated from rock bream, Oplegnathus fasciatus (Temminck & Schlegel)
Authors: Kim T J , Jung T S , Lee J I
Published: October 2007

Iridoviruses infect a wide variety of wild and cultured fish. Those iridoviruses belonging to the genus Ranavirus, in the Iridoviridae family, cause systemic disease in infected animals with a high morbidity and mortality. This paper reports the cloning, sequencing, and expression of the rock bream iridovirus (RBIV) major capsid protein (MCP) in an Escherichia coli expression system for subsequent immunological studies. The completeness of the expressed protein was confirmed by peptide mass fingerprinting (PMF) analysis using MALDI‐TOF MS. The recombinant MCP (rMCP)‐specific mouse polyclonal antibody reacted with the viral 52 kDa protein, indicating that this rMCP induces an immunological response. Fish antibodies induced against iridovirus infection were also detected using ELISA when rMCP was used as an antigen. As a result, it was found that many cultured rock bream (92.5%) were naturally infected with iridovirus and that the rMCP might be useful for serological tests.
Deficiencies in the standardization and sensitivity of diagnostic tests for hepatitis B virus
Authors: Gerlich W. H. , Glebe D. , Schüttler C. G.
Published: October 2007

Summary.  The patterns of hepatitis B virus (HBV) markers described in textbooks apply to acute and chronic infection with wild‐type HBV. Deviations from these patterns occur in the very early phase, in low‐level (or occult) infection and under immunosuppression. Variability may originate from the virus, the host or the test kits. In order to obtain a reliable diagnosis under these conditions, tests for all three markers of HBV infection have to be applied: HBsAg, HBV DNA and anti‐HBc. All tests should be as sensitive as feasible, but even then occult infection may be missed. Reliable detection of occult or mutated HBV is particularly important in blood and organ donors and in patients before or with immunosuppression.
Vaccines and immunotherapies against hepatitis B and hepatitis C viruses
Authors: Inchauspé G. , Michel M. L.
Published: October 2007

Summary.  Both hepatitis B and hepatitis C viruses (HBV and HCV) cause chronic infections worldwide that are associated with development of liver diseases ranging from mild liver inflammation to hepatocellular carcinomas. While efficient preventive vaccines are available for HBV, efforts are ongoing to develop one in case of HCV. Yet, both infections share the fact that therapeutic agents available to treat already established infections are yet poorly efficient, toxic or associated with development of resistance. Thus, novel immune‐based therapies are actively being developed to complement or replace standard antiviral treatments. Among those, development of therapeutic vaccines represents a major effort. Peptide‐, recombinant protein‐ or viral vector‐based vaccines have been engineered and tested at preclinical and clinical levels. Means to adjuvant these vaccines are being pursued, including approaches based on combining vaccines of different nature. This review will outline major advances in the field of both HBV and HCV therapeutic vaccine development with a particular focus on candidates presented at the 12th International Symposium on Viral Hepatitis and Liver Disease (July 2006, Paris, France).
Transcription factor AtTCP14 regulates embryonic growth potential during seed germination in Arabidopsis thaliana
Authors: Tatematsu Kiyoshi , Nakabayashi Kazumi , Kamiya Yuji , Nambara Eiji
Published: October 2007

To understand the molecular mechanisms underlying regulation of seed germination, we searched enriched cis elements in the upstream regions of Arabidopsis genes whose transcript levels increased during seed germination. Using available published microarray data, we found that two cis elements, Up1 or Up2, which regulate outgrowth of Arabidopsis axillary shoots, were significantly over‐represented. Classification of Up1‐ and Up2‐containing genes by gene ontology revealed that protein synthesis‐related genes, especially ribosomal protein genes, were highly over‐represented. Expression analysis using a reporter gene driven by a synthetic promoter regulated by these elements showed that the Up1 is necessary and sufficient for germination‐associated gene induction, whereas Up2 acts as an enhancer of Up1. Up1‐mediated gene expression was suppressed by treatments that blocked germination. Up1 is almost identical to the site II motif, which is the predicted target of TCP transcription factors. Of 24 AtTCP genes, AtTCP14, which showed the highest transcript level just prior to germination, was functionally characterized to test its involvement in the regulation of seed germination. Transposon‐tagged lines for AtTCP14 showed delayed germination. In addition, germination of attcp14 mutants exhibited hypersensitivity to exogenously applied abscisic acid and paclobutrazol, an inhibitor of gibberellin biosynthesis. AtTCP14 was predominantly expressed in the vascular tissues of the embryo, and affected gene expression in radicles in a non‐cell‐autonomous manner. Taken together, these results indicate that AtTCP14 regulates the activation of embryonic growth potential in Arabidopsis seeds.
Improving the precision of cotton performance trials conducted on highly variable soils of the southeastern USA coastal plain
Authors: Campbell B. T. , Bauer P. J.
Published: October 2007

Reliable agronomic and fibre quality data generated in Upland cotton (Gossypium hirsutumL.) cultivar performance trials are highly valuable. The most common strategy used to generate reliable performance trial data uses experimental design to minimize experimental error resulting from spatial variability. However, an alternative strategy usesa posterioristatistical procedures to account for spatial variability. In this study, the efficiency of the randomized complete block (RCB) design and nearest neighbour adjustment (NNA) were compared in a series of cotton performance trials conducted in the southeastern USA to identify the efficiency of each in minimizing experimental error for yield, yield components and fibre quality. In comparison to the RCB, relative efficiency of the NNA procedure varied amongst traits and trials. Results show that experimental analyses, depending on the trait and selection intensity employed, can affect cultivar or experimental line selections. Based on this study, we recommend researchers conducting cotton performance trials on variable soils consider using NNA or other spatial methods to improve trial precision.
Imaging of painful solitary lesions of the sacrum
Authors: Peh WCG , Koh WL , Kwek JW , Htoo MM , Tan PH
Published: October 2007

In patients with sacral pain, the painful symptoms may be caused by a variety of bony and soft tissue lesions. Benign lesions include giant cell tumour, neurogenic tumour, insufficiency fracture, infection and giant bone island. Malignant lesions include primary bone tumours, Ewing sarcoma, plasmacytoma, lymphoma and chordoma. Soft tissue tumours adjacent to or involving the sacrum may cause painful symptoms. A multimodality approach to imaging is required for full assessment of these lesions. This pictorial essay describes a range of common solitary sacral lesions that may cause pain, with emphasis on imaging features.
Do kidney sizes in ultrasonography correlate to glomerular filtration rate in healthy children?
Authors: Adibi A , Adibi I , Khosravi P
Published: October 2007

The objective of this study was to determine the correlation between ultrasonographic kidney sizes and glomerular filtration rate (GFR) in healthy children. This was a cross‐section study on 116 healthy children. Renal diseases were ruled out by a paediatric nephrologist. Ultra sonography of both kidneys was carried out by an experienced radiologist. The volume was calculated by ellipsoid formula. We defined net volume as kidney volume − sinus fat volume’. The sum of right and left kidney sizes was defined as total sizes. We calculated GFR by means of the Schwartz formula. Correlations between kidney sizes and GFR were studied with Pearson correlation coefficient. The mean age of the children was 8.4 ± 3.4. The GFR mean was 108 ± 30 (mL/min per 1.73 m2). GFR correlated to total renal volume (r = 0.52, P < 0.001), total net volume (r = 0.53, P < 0.001) and total kidney length (r = 0.59, P < 0.001). Ultrasonographic kidney sizes, especially the kidney length, correlate to GFR in healthy children. Kidney sizes assessment by ultrasonography may play a role in renal function evaluation in children.
Isolated limb infusion for local control of lower limb melanoma: Radiologic aspects
Authors: Cassumbhoy R , Pitman AG
Published: October 2007

To describe the technical radiological aspects of isolated limb infusion (ILI) to assist those procedural radiologists who carry out ILI on an occasional only basis and to inform the Australian radiologist community about this deserving but relatively little known radiological procedure. Retrospective audit of radiological catheter placement for 23 lower limb ILI procedures carried out for 16 patients with locally recurrent melanoma over 2 years (January 2002 to December 2003). Arterial and venous catheter placement, although sometimes difficult, was successful in all but four occasions. Unfavourable vascular anatomy was the main reason for failure. If approached systematically and with the knowledge of the patient’s vascular anatomy, the outcome will be satisfactory in the hands of the generalist. Knowing the common technical pitfalls will certainly assist. Isolated limb infusion deserves to be more widely known in the radiological and surgical communities.
Mediastinal thymolipoma: An analysis of 10 cases
Authors: DAMADOGLU Ebru , SALTURK Cuneyt , TAKIR Huriye Berk , ERTUGRUL Muyesser , YILMAZ Aynur , ATASALIHI Ali , YILMAZ Adnan
Published: October 2007

Abstract:  Thymolipoma is a benign tumour composed of thymic elements and adipose tissue. It may be associated with myasthenia gravis or immune disorders. We aimed to evaluate the clinical and radiological features of thymolipoma. The clinical data from 10 cases of thymolipoma, diagnosed at our centre between 2002 and 2004, were analysed retrospectively. There were six female and four male patients, whose ages ranged from 16 to 67 years, with a mean age of 34.1 years. All but two patients had pulmonary or extrapulmonary symptoms. Five patients also had myasthenia gravis. All thymolipomas were localized in the anterior superior mediastinum. The surgical approach was sternotomy in nine cases and thoracotomy in one case. Thymectomy was performed on all patients. Thymolipomas are unusual tumours and may be associated with myasthenia gravis. Surgical resection is the most appropriate treatment modality.
Middle mediastinal thymoma
Authors: HUANG Tsai‐Wang , CHENG Yeung‐Leung , TZAO Ching , CHANG Hung , TSAI Wen‐Chiuan , LEE Shih‐Chun
Published: October 2007

Abstract:  Thymoma is a common primary neoplasm of the anterior mediastinum. However, it can also arise in other locations, including the neck, the posterior mediastinum, the lung, base of the skull and the pleural cavity. There are only three previous case reports of thymoma located in the middle mediastinum. This report describes a patient together with a review of the literature on middle mediastinal thymoma.
Pollen proteolytic enzymes degrade tight junctions
Authors: RUNSWICK Sarah , MITCHELL Thomas , DAVIES Paul , ROBINSON Clive , GARROD David R.
Published: October 2007

Background and objective:  Asthma and allergic rhinitis are significant, increasing causes of morbidity worldwide. Pollen, a major cause of seasonal rhinitis/conjunctivitis, carries proteolytic enzymes on its surface. We showed previously that peptidase allergens from house dust mites compromise epithelial barrier function by degrading the extracellular domains of the tight junction proteins, occludin and claudin, thus facilitating allergen delivery across epithelial layers. In this study, we aimed to determine whether peptidases from allergenic pollens should similarly be considered to have a role in disrupting tight junctions.

Methods:  Diffusates from stored pollen of Giant Ragweed, White Birch and Kentucky Blue Grass, and fresh pollen from Easter Lily were applied to confluent monolayers of Madin‐Darby canine kidney (MDCK) and Calu‐3 cells in serum‐free medium. Immunofluorescence was performed for the tight junction proteins, occludin, claudin‐1 and ZO‐1. The effect of pollen diffusate on occludin was studied by Western blotting, and enzymatic activity in the diffusates was demonstrated by zymography. The ability of protease inhibitors to block the action of the diffusate on tight junctions was investigated.

Results:  Diffusates from all four allergenic pollens caused loss of immunofluorescence labelling for tight junction proteins on MDCK and Calu‐3 cells. The effect was blocked by inhibitors of serine and cysteine proteases. Degradation of occludin was demonstrated by Western blotting and zymography indicated that diffusates contain proteolytic activity.

Conclusions:  Pollen peptidases directly or indirectly disrupt epithelial tight junctions, and this activity should be considered as a possible mechanism for facilitating allergen delivery across epithelia.
Nurses' experiences of delivering voluntary counseling and testing services for people with HIV/AIDS in the Vhembe District, Limpopo Province, South Africa
Authors: Mavhandu‐Mudzusi Azwihangwisi H. , Netshandama Vhonani O. , Davhana‐Maselesele Mashudu
Published: October 2007

Abstract  Voluntary counseling services are seen as a cost‐effective strategy for HIV prevention and management because they help people to cope with their illness and reduce infection rates in others. This study explored and described the experiences of 20 nurses who rendered voluntary counseling in the Vhembe district, Limpopo Province, South Africa. A qualitative and contextual research design was used, with data gathered from in‐depth individual interviews and analyzed using an open‐coding method. The main experiences of the nurses rendering voluntary counseling and testing arose in the following themes: challenges related to inadequate resources; the emotional drain associated with stress and burnout; and frustration related to certain behaviors and practices of clients and community members. The main conclusions drawn from the findings were that nurses are continuously exposed to emotionally draining activities with very little support from their supervisors, which makes them prone to experiencing burnout.
Tackling heart disease and poverty
Authors: Lee Geraldine , Carrington Melinda
Published: October 2007

Abstract  Cardiovascular disease is the leading cause of death worldwide, with a projected increase in incidence in developed and developing countries. This paper will review the literature on the role of poverty and socioeconomic deprivation in cardiovascular disease and outline ways to tackle poverty. The literature acknowledges the individual risk factors for cardiovascular disease, but highlights the negative effects of neighborhood deprivation on the incidence of cardiovascular disease and its mortality rates. The studies show that equitable access to health care is not evident and those in less affluent neighborhoods have greater disease incidence and increased mortality and morbidity rates, particularly for angina, myocardial infarction, and heart failure. The approach to reducing disease rates needs to be conducted from an individual level to the societal level and needs to prevent and treat heart disease (particularly in deprived neighborhoods). Nurses and health professionals must drive health policy so that progress can be achieved in reducing the disease rates.
Competing Processes of Sibling Influence: Observational Learning and Sibling Deidentification
Authors: Whiteman Shawn D. , McHale Susan M. , Crouter Ann C.
Published: October 2007

Although commonly cited as explanations for patterns of sibling similarity and difference, observational learning and sibling deidentification processes have rarely been examined directly. Using a person‐oriented approach, we identified patterns in adolescents' perceptions of sibling influences and connected these patterns to sibling similarities and differences and sibling relationship qualities. Participants included two adolescent‐age siblings (firstborn age M = 16.39, second‐born age M = 13.78) from 171 maritally intact families. Two‐stage cluster analyses revealed three sibling influence profiles: modeling, deidentification, and non‐reference. Analyses revealed differences in the correlations between firstborn and second‐born siblings' personal qualities across the three groups and differences in the sibling relationship qualities of younger siblings who reported modeling vs. those who reported deidentifying from their older siblings. Discussion focuses on refining the study of sibling influence processes.