bluuebunny/crossref_metadata_2025 huggingface dataset:
Time correlations and the second entropy
Authors: Gray-Weale Angus , Attard Phil
Published: July 2007

The authors study the transport of mass and heat in simulations of a Lennard-Jones fluid and demonstrate the calculation of transport coefficients, and of both the first and second entropies. These entropies are calculated from time correlation functions, as are the transport coefficients. They discuss the role of the second entropy in providing a physical explanation for the link between dynamic fluctuations and response. They illustrate the physical significance of the various contributions to the second entropy and how they simplify in the case of relaxation by steady-state flow. Certain approximations proposed for the calculation of the first entropy, common in the literature, are shown to break down under certain circumstances, and they give an improved method of calculation. They pay particular attention to the coupling between variables of opposite time parity in the transport matrix, and show that in general this cannot be neglected.
Eulerian-Lagrangian aspects of a steady multiscale laminar flow
Authors: Rossi Lionel , Vassilicos John-Christos , Hardalupas Yannis
Published: July 2007

One key feature for the understanding and control of turbulent flows is the relation between Eulerian and Lagrangian statistics. This Brief Communication investigates such a relation for a laminar quasi-two-dimensional multiscale flow generated by a multiscale (fractal) forcing, which reproduces some aspects of turbulent flows in the laboratory, e.g., broadband power-law energy spectrum and Richardson’s diffusion. We show that these multiscale flows abide with Corrsin’s estimation of the Lagrangian integral time scale, TL, as proportional to the Eulerian (integral) time scale, LE∕urms, even though Corrsin’s approach was originally constructed for high Reynolds number turbulence. We check and explain why this relation is verified in our flows. The Lagrangian energy spectrum, Φ(w), presents a plateau at low frequencies followed by a power-law energy spectrum Φ(w)∼w−α at higher ones, similarly to turbulent flows. Furthermore, Φ(ω) scales with LE and urms with α>1. These are the key elements to obtain such a relation [Φ(w)∼ϵw−2 is not necessary] as in our flows the dissipation rate varies as ϵ∼urms3∕LEReλ−1. To complete our analysis, we investigate a recently proposed relation [M. A. I. Khan and J. C. Vassilicos, Phys. Fluids 16, 216 (2004)] between Eulerian and Lagrangian structure functions, which uses pair-diffusion statistics and the implications of this relation on Φ(ω). Our results support this relation, ⟨[uL(t)−uL(t+τ)]2⟩=⟨[uE(x)−uE(x+Δ2¯(τ)e)]2⟩, which leads to α=γ∕2(p−1)+1. This Eulerian-Lagrangian relation is striking as in the present flows it is imposed by the multiscale distribution of stagnation points, which are an Eulerian property.
Cooperative molecular field effect and induced orientational ordering effect in polar liquid crystalline films on metals
Authors: Taguchi Dai , Kajimoto Norifumi , Manaka Takaaki , Iwamoto Mitsumasa
Published: July 2007

Using the in situ measurements of the surface potential built across the evaporated liquid crystalline 4-n-pentyl-4′-cyanobiphenyl (5CB) films on metal electrodes with different work functions, we studied the cooperative molecular field effect (CMFE) that assists carrier injection from electrodes and the induced orientational reordering in evaporated liquid crystalline molecules on metals. The surface potential increased, and then became constant after the 5CB monomolecular layer was formed. It was shown that the CMFE accompanying orientational reordering accounts for the metal work function dependence of the surface potential. Finally, the orientational reordering is discussed in terms of the anchoring energy.
Space charge limited two-dimensional electron flow in a rectangular geometry
Authors: Rokhlenko A. , Lebowitz J. L.
Published: July 2007

We study the spatial structure of the space charge limited current and electric field in a rectangle of arbitrary aspect ratio. The cathode and anode form two horizontal sides of the rectangle and a strong magnetic field forces the current to flow perpendicular to the electrodes. Using conformal mapping techniques we calculate the electric field outside this rectangle for any given potential distribution on its vertical boundaries. Inside the current rectangle we have a nonlinear Poisson equation with extra boundary conditions for two unknown functions: The potential and the current density. Both exhibit singular behavior at the edges of the rectangle. A semianalytic approximate method is developed for this unusual boundary value problem: We first match the boundary fields inside and outside the current region and then, using trial functions consistent with these matching conditions, we apply the least square technique and iterations to construct the solution in the current region. The analysis of the flow shows that the current wings are similar for all currents wider than one of the square cross section. There is also evidence that the total current does not vanish when the width goes to zero. The method of calculation appears generalizable to various geometries of vacuum and solid state devices.
On the two-fluid modification of the resistive tearing instability
Authors: Bian N. , Vekstein G.
Published: July 2007

We consider the two-fluid resistive tearing mode for an inviscid highly conducting (a large Lundquist number S) plasma in a sheared force-free magnetic field. It is shown that under the “constant-ψ” approximation there are four possible instability regimes, each of which corresponds to the specific domain in the parameter space (β,di). Here, β is a standard plasma thermal pressure parameter, while di≡c∕(ωpil) is the normalized ion inertial skin depth, with l being the shear length of the magnetic field. A qualitative analysis emphasizing when and why the transitions from one regime to another occur is also provided.
Energy gaps in zero-dimensional graphene nanoribbons
Authors: Shemella Philip , Zhang Yiming , Mailman Mitch , Ajayan Pulickel M. , Nayak Saroj K.
Published: July 2007

The finite size effects on the electronic structure of graphene ribbons are studied using first principles density functional techniques. The energy gap [difference between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO)] dependence for finite width and length is computed for both armchair and zigzag ribbons and compared to their one-dimensional (infinite length) cases. The results suggest, in addition to quantum confinement along the width of the ribbon, an additional finite size effect emerges along the length of ribbons only for metallic armchair ribbons. The origin of additional quantum confinement in these structures is analyzed based on the energy states near the Fermi energy: both HOMO and LUMO energy levels for metallic armchair ribbons are delocalized entirely on the ribbons while for nonmetallic ribbons, these states are localized at the edges only. The results are discussed in light of effect of passivation on the electronic properties of graphenes and their impact on nanoelectronic devices based on graphenes.
Acquisition of a nuclear magnetic resonance signal using an electric field detection technique
Authors: Prance R. J. , Aydin A.
Published: July 2007

The authors describe an alternative approach to signal acquisition in nuclear magnetic resonance and demonstrate this by measuring the free induction decay signal from a sample of glycerine. Traditionally, these systems have operated using pulse radio frequency excitation and magnetic (inductive) readout. This approach identifies the previously unmeasured electric field signal associated with the precessing nuclear spins and provides an alternative capacitive (noninductive) readout. The possible advantages which may accrue from this technique include a reduction in the dead time and the cross coupling between the transmitter and the receiver, a simpler receiver implementation, and an inherently high spatial resolution.
Effect of interfacial oxynitride layer on the band alignment and thermal stability of LaAlO3 films on SiGe
Authors: Mi Y. Y. , Wang S. J. , Chai J. W. , Seng H. L. , Pan J. S. , Foo Y. L. , Huan C. H. A. , Ong C. K.
Published: July 2007

The effect of interfacial oxynitride layer on the band alignment and thermal stability of amorphous LaAlO3∕Si0.75Ge0.25 heterojunction has been investigated. The presence of interfacial oxynitride layer shifts the band alignment due to the modification of interfacial dipole. During the thermal annealing, it was found that the interfacial electronic structures were altered, and the valence-band maximum of LaAlO3 films shifted to the lower energy due to the diffusion of nitrogen species from the interfaces into LaAlO3 films at high annealing temperature.
Detection of field-induced single-acceptor ionization in Si by single-hole-tunneling transistor
Authors: Burhanudin Zainal A. , Nuryadi Ratno , Tabe Michiharu
Published: July 2007

The authors have detected the ionization of single-acceptors in the underlying p on p+ substrate of a silicon-on-insulator (SOI) wafer using a single-hole-tunneling (SHT) transistor fabricated in the top Si layer of the SOI at low temperatures. It was found that freeze-out boron atoms in the substrate are sequentially ionized from near the buried SiO2∕p-Si substrate interface to deeper positions by application of a vertical electric field, creating steplike features in the time-dependent SHT current.
Mobility enhancement in strained p-InGaSb quantum wells
Authors: Bennett Brian R. , Ancona Mario G. , Boos J. Brad , Shanabrook Benjamin V.
Published: July 2007

Quantum wells of InGaSb clad by AlGaSb were grown by molecular beam epitaxy. The InGaSb is in compressive strain, resulting in a splitting of the heavy- and light-hole valence bands and an enhancement of the mobility. The mobility was found to increase with increasing InSb mole fraction for values of strain up to 2%. Room-temperature mobilities as high as 1500cm2∕Vs were reached for 7.5nm channels of In0.40Ga0.60Sb. These results are an important step toward the goal of high-performance p-channel field-effect transistors for complementary circuits operating at extremely low power.
Wave interference effect on polymer microstadium laser
Authors: Fang W. , Cao H.
Published: July 2007

The authors investigate the lasing modes in fully chaotic polymer microstadiums under optical pumping. The lasing modes are regularly spaced in frequency, and their amplitudes oscillate with frequency. The numerical simulations reveal that the lasing modes are multiorbit scar modes. The interference of partial waves propagating along the constituent orbits results in local maxima of quality factor at certain frequencies. The observed modulation of lasing mode amplitude with frequency results from the variation of quality factor, which provides the direct evidence of wave interference effect in open chaotic microcavities.
Annealing effects on the optical properties of a GaInNAs double barrier quantum well infrared photodetector
Authors: Ma B. S. , Fan W. J. , Dang Y. X. , Cheah W. K. , Yoon S. F.
Published: July 2007

Annealing effects in a GaInNAs∕AlAs∕AlGaAs double barrier quantum well infrared photo detector were studied by x-ray diffraction, photoluminescence (PL), and photoluminescence excitation (PLE) spectroscopy. After annealing at 650°C, the GaInNAs PL peak shows stronger PL intensity and blueshift of 40meV mainly due to the group-III interdiffusion. As the annealing temperature increases to 825°C, the blueshift decreases from 40to15meV due to the nitrogen substitutional-interstitional kickout effect, Al∕Ga interdiffusion at the AlAs∕AlGaAs interface, and strain reduction. After annealing, the difference between the PLE peak energy and the detection energy decreases with increasing detection energy because of the redistribution of elemental concentrations.
High permittivity and low dielectric loss in ceramics with the nominal compositions of CaCu3−xLa2x∕3Ti4O12
Authors: Shao S. F. , Zhang J. L. , Zheng P. , Wang C. L. , Li J. C. , Zhao M. L.
Published: July 2007

Ceramics with the nominal compositions of CaCu3−xLa2x∕3Ti4O12 were prepared by the conventional solid-state reaction technique. It was found that these ceramics have the properties of rather high dielectric permittivity and sufficiently low dielectric loss. In particular, CaCu2.9La0.2∕3Ti4O12 ceramics sintered at 1050°C for 20h showed the high dielectric permittivity of 7500 with weak frequency dependence below 1MHz, the low dielectric loss less than 0.05 in the wide frequency range of 120Hz–200kHz (with the minimum 0.012 at 20kHz), and the small temperature coefficient about ±15ppm∕°C between −80 and 125°C. From the analysis, it was suggested that CaTiO3 secondary phase due to Cu deficiency and La doping plays the important roles in the observed excellent dielectric properties in CaCu3−xLa2x∕3Ti4O12 ceramics. The results indicated that they are a very promising class of high-permittivity materials for practical applications.
Self-organized metal nanostructures through laser-interference driven thermocapillary convection
Authors: Favazza C. , Trice J. , Kalyanaraman R. , Sureshkumar R.
Published: July 2007

Here the authors investigate self-organization and the ensuing length scales when Co films (1–8nm thick) on SiO2 surfaces are repeatedly and rapidly melted by nonuniform (interference) laser irradiation. Pattern evolution produces periodic nanowires, which eventually breakup into nanoparticles exhibiting spatial order in the nearest-neighbor (NN) spacing λNN2. For films of thickness h0>2nm, λNN2∝h01∕2 while the particle radius varies as rp2∝h01∕2. This scaling behavior is consistent with pattern formation by a thermocapillary flow and a Rayleigh-like instability. For h0⩽2nm, a hydrodynamic instability of a spinodally unstable film leads to the formation of nanoparticles.
Stabilizing excited-state silicon nanoparticle by surface oxidation
Authors: Li Q. S. , Zhang R. Q. , Lee S. T. , Niehaus T. A. , Frauenheim Th.
Published: July 2007

Si–Si and Si–H bonds in small hydrogenated Si particles are known to readily dissociate upon photoexcitation, which hinders various optical applications of Si particles. The authors show that the Si core could be stabilized in the presence of double-bonded oxygen (SiO) on the surface, based on excited-state calculations of a series of oxidized Si particles from Si5H10O to Si199H138O using the density-functional tight-binding method. The authors revealed that the stabilization effect is due to localization of excited-state relaxation mainly in the SiO region, which becomes significant when the particle size decreases. The possibility of fabricating stable Si nanoparticles by introducing a small amount of oxygen on the surface and the stabilization effect have important implications in device fabrications.
Fully epitaxial (Zn,Co)O∕ZnO∕(Zn,Co)O junction and its tunnel magnetoresistance
Authors: Song C. , Liu X. J. , Zeng F. , Pan F.
Published: July 2007

The authors report tunnel magnetoresistance (TMR) and its bias dependence in fully epitaxial (Zn,Co)O∕ZnO∕(Zn,Co)O magnetic tunnel junctions. A positive TMR of 20.8% is obtained at 4K, which can resist up to room temperature with the TMR ratio of 0.35% at 2T, due to improved crystallinity of barriers and electrode/barrier interfaces. The decay of TMR with bias up to 2V is significantly small leading to V1∕2, for which half of the TMR remains, well over 2V, shedding promising light on solving readout problems in gigabit-scale magnetoresistive random access memory.
Gate insulation and drain current saturation mechanism in InAlN∕GaN metal-oxide-semiconductor high-electron-mobility transistors
Authors: Pozzovivo G. , Kuzmik J. , Golka S. , Schrenk W. , Strasser G. , Pogany D. , Čičo K. , Ťapajna M. , Fröhlich K. , Carlin J.-F. , Gonschorek M. , Feltin E. , Grandjean N.
Published: July 2007

The authors investigate 2μm gate-length InAlN∕GaN metal-oxide-semiconductor high-electron-mobility transistors (MOS HEMTs) with 12nm thick Al2O3 gate insulation. Compared to the Schottky barrier (SB) HEMT with similar design, the MOS HEMT exhibits a gate leakage reduction by six to ten orders of magnitude. A maximal drain current density (IDS=0.9A∕mm) and an extrinsic transconductance (gme=115mS∕mm) of the MOS HEMT also show improvements despite the threshold voltage shift. An analytical modeling shows that a higher mobility of electrons in the channel of the MOS HEMT and consequently a higher number of electrons attaining the velocity saturation may explain the observed increase in gme after the gate insulation.
Semiconducting polymer coated single wall nanotube field-effect transistors discriminate holes from electrons
Authors: Chawla Jasmeet S. , Gupta Dhritiman , Narayan K. S. , Zhang R.
Published: July 2007

Single wall carbon nanotube (SWNT) based field effect transistors (FET) coated with semiconducting polymers respond to photoexcitation revealing characteristic features which depend on the electronic structure of the polymer. The authors observe a decrease in the drain source current of the SWNTFET in the accumulation mode in an environment of acceptor type polymer network, and a significant increase in the current in the depletion mode for a donor type polymer network around the nanotube.
Innate immunity and transcription of MGAT-III and Toll-like receptors in Alzheimer's disease patients are improved by bisdemethoxycurcumin
Authors: Fiala Milan , Liu Philip T. , Espinosa-Jeffrey Araceli , Rosenthal Mark J. , Bernard George , Ringman John M. , Sayre James , Zhang Laura , Zaghi Justin , Dejbakhsh Sheila , Chiang Ben , Hui James , Mahanian Michelle , Baghaee Anita , Hong Pamela , Cashman John
Published: July 2007

We have tested a hypothesis that the natural product curcuminoids, which has epidemiologic and experimental rationale for use in AD, may improve the innate immune system and increase amyloid-β (Aβ) clearance from the brain of patients with sporadic Alzheimer's disease (AD). Macrophages of a majority of AD patients do not transport Aβ into endosomes and lysosomes, and AD monocytes do not efficiently clear Aβ from the sections of AD brain, although they phagocytize bacteria. In contrast, macrophages of normal subjects transport Aβ to endosomes and lysosomes, and monocytes of these subjects clear Aβ in AD brain sections. Upon Aβ stimulation, mononuclear cells of normal subjects up-regulate the transcription of β-1,4-mannosyl-glycoprotein 4-β-
N
-acetylglucosaminyltransferase (
MGAT3
) (
P
< 0.001) and other genes, including Toll like receptors (
TLRs
), whereas mononuclear cells of AD patients generally down-regulate these genes. Defective phagocytosis of Aβ may be related to down-regulation of
MGAT3
, as suggested by inhibition of phagocytosis by using
MGAT3
siRNA and correlation analysis. Transcription of
TLR3
, bditTLR4,
TLR5
, bditTLR7,
TLR8
,
TLR9
, and
TLR10
upon Aβ stimulation is severely depressed in mononuclear cells of AD patients in comparison to those of control subjects. In mononuclear cells of some AD patients, the curcuminoid compound bisdemethoxycurcumin may enhance defective phagocytosis of Aβ, the transcription of
MGAT3
and TLRs, and the translation of TLR2–4. Thus, bisdemethoxycurcumin may correct immune defects of AD patients and provide a previously uncharacterized approach to AD immunotherapy.
15
N photochemically induced dynamic nuclear polarization magic-angle spinning NMR analysis of the electron donor of photosystem II
Authors: Diller Anna , Roy Esha , Gast Peter , van Gorkom Hans J. , de Groot Huub J. M. , Glaubitz Clemens , Jeschke Gunnar , Matysik Jörg , Alia A.
Published: July 2007

In natural photosynthesis, the two photosystems that operate in series to drive electron transport from water to carbon dioxide are quite similar in structure and function, but operate at widely different potentials. In both systems photochemistry begins by photo-oxidation of a chlorophyll
a
, but that in photosystem II (PS2) has a 0.7 eV higher midpoint potential than that in photosystem I (PS1), so their electronic structures must be very different. Using reaction centers from
15
N-labeled spinach, these electronic structures are compared by their photochemically induced dynamic nuclear polarization (photo-CIDNP) in magic-angle spinning (MAS) NMR measurements. The results show that the electron spin distribution in PS1, apart from its known delocalization over 2 chlorophyll molecules, reveals no marked disturbance, whereas the pattern of electron spin density distribution in PS2 is inverted in the oxidized radical state. A model for the donor of PS2 is presented explaining the inversion of electron spin density based on a tilt of the axial histidine toward pyrrole ring IV causing π-π overlap of both aromatic systems.
Transcriptional network governing the angiogenic switch in human pancreatic cancer
Authors: Abdollahi Amir , Schwager Christian , Kleeff Jörg , Esposito Irene , Domhan Sophie , Peschke Peter , Hauser Kai , Hahnfeldt Philip , Hlatky Lynn , Debus Jürgen , Peters Jeffrey M. , Friess Helmut , Folkman Judah , Huber Peter E.
Published: July 2007

A shift of the angiogenic balance to the proangiogenic state, termed the “angiogenic switch,” is a hallmark of cancer progression. Here we devise a strategy for identifying genetic participants of the angiogenic switch based on inverse regulation of genes in human endothelial cells in response to key endogenous pro- and antiangiogenic proteins. This approach reveals a global network pattern for vascular homeostasis connecting known angiogenesis-related genes with previously unknown signaling components. We also demonstrate that the angiogenic switch is governed by simultaneous regulations of multiple genes organized as transcriptional circuitries. In pancreatic cancer patients, we validate the transcriptome-derived switch of the identified “angiogenic network:” The angiogenic state in chronic pancreatitis specimens is intermediate between the normal (angiogenesis off) and neoplastic (angiogenesis on) condition, suggesting that aberrant proangiogenic environment contributes to the increased cancer risk in patients with chronic pancreatitis. In knockout experiments in mice, we show that the targeted removal of a hub node (peroxisome proliferative-activated receptor δ) of the angiogenic network markedly impairs angiogenesis and tumor growth. Further, in tumor patients, we show that peroxisome proliferative-activated receptor δ expression levels are correlated with advanced pathological tumor stage, increased risk for tumor recurrence, and distant metastasis. Our results therefore also may contribute to the rational design of antiangiogenic cancer agents; whereas “narrow” targeted cancer drugs may fail to shift the robust angiogenic regulatory network toward antiangiogenesis, the network may be more vulnerable to multiple or broad-spectrum inhibitors or to the targeted removal of the identified angiogenic “hub” nodes.
An unusual cytokine:Ig-domain interaction revealed in the crystal structure of leukemia inhibitory factor (LIF) in complex with the LIF receptor
Authors: Huyton Trevor , Zhang Jian-Guo , Luo Cindy S. , Lou Mei-Zhen , Hilton Douglas J. , Nicola Nicos A. , Garrett Thomas P. J.
Published: July 2007

Leukemia inhibitory factor (LIF) receptor is a cell surface receptor that mediates the actions of LIF and other IL-6 type cytokines through the formation of high-affinity signaling complexes with gp130. Here we present the crystal structure of a complex of mouse LIF receptor with human LIF at 4.0 Å resolution. The structure is, to date, the largest cytokine receptor fragment determined by x-ray crystallography. The binding of LIF to its receptor via the central Ig-like domain is unlike other cytokine receptor complexes that bind ligand predominantly through their cytokine-binding modules. This structure, in combination with previous crystallographic studies, also provides a structural template to understand the formation and orientation of the high-affinity signaling complex between LIF, LIF receptor, and gp130.
Identification of a chloride ion binding site in Na+/Cl−-dependent transporters
Authors: Forrest Lucy R. , Tavoulari Sotiria , Zhang Yuan-Wei , Rudnick Gary , Honig Barry
Published: July 2007

The recent determination of the crystal structure of the leucine transporter fromAquifex aeolicus(aaLeuT) has provided significant insights into the function of neurotransmitter:sodium symporters. Transport by aaLeuT is Cl−independent, whereas many neurotransmitter:sodium symporters from higher organisms depend on Cl−ions. However, the only Cl−ion identified in the aaLeuT structure interacts with nonconserved residues in extracellular loops, and thus the relevance of this binding site is unclear. Here, we use calculations of pKAs and homology modeling to predict the location of a functionally important Cl−binding site in serotonin transporter and other Cl−-dependent transporters. We validate our model through the site-directed mutagenesis of residues predicted to coordinate the Cl−ion and through the observation of sequence conservation patterns in other Cl−-dependent transporters. The proposed site is located midway across the membrane and is formed by residues from transmembrane helices 2, 6, and 7. It is close to the Na1 sodium binding site, thus providing an explanation for the coupling of Cl−and Na+ions during transport. Other implications of the model are also discussed.
Total or subtotal hysterectomy for benign uterine diseases? A meta‐analysis
Authors: GIMBEL HELGA
Published: July 2007

Background. Total and subtotal abdominal hysterectomy for benign indications have been compared in randomized clinical trials and observational studies. A meta‐analysis is performed to summarize the evidence. Methods. Thirty‐four randomized clinical trials and observational studies comparing total and subtotal abdominal hysterectomy for benign indications were included. Endpoints were self‐reported urinary incontinence, postoperative complications, operation time, quality of life, constipation, prolapse, sexual functioning, pelvic pain, and cervical stump problems after subtotal hysterectomy. Odds ratios and tests for heterogeneity and overall effect were calculated. Results. Urinary incontinence and prolapse showed a significant difference favoring the total hysterectomy. Some of the women having a subtotal hysterectomy had cervical stump problems (bleeding and abnormal smear). Operation time and peroperative bleeding are postoperative complications were significantly in favor of the subtotal hysterectomy. Lower urinary tract symptoms other than incontinence, quality of life, constipation, pelvic pain, and sexual life were not in favor of either of the hysterectomy methods. Conclusion. Less women suffered from urinary incontinence and prolapse and cervical stump problems after total than after subtotal hysterectomy. However, subtotal hysterectomy is faster to perform, has less peroperative bleeding, and seems to have less intra‐ and postoperative complications.
Effect of passive uterine straightening during embryo transfer: a systematic review and meta‐analysis
Authors: ABOU‐SETTA AHMED M.
Published: July 2007

Background. Part of the success of ultrasound‐guided embryo transfer has been associated with the beneficial effect of uterine straightening by passive bladder distention. Even so, this has not been properly analysed in the literature. Methods. This is a systematic review and meta‐analysis of prospective, randomised, controlled trials, comparing embryo transfer with a full versus empty bladder. Electronic (e.g. PubMed, EMBASE, Cochrane Library) and hand searches were performed to locate trials. Primary outcomes were live‐birth, ongoing and clinical pregnancy rates. Secondary outcomes were rates of implantation, miscarriage, multiple and ectopic pregnancies, and retained embryos. Also, the ease of transfer, need for instrumental assistance, and presence of blood on the catheter tip were evaluated. Four studies were identified, of which 1 study was excluded. Meta‐analysis was conducted with the Mantel–Haenszel method, utilising the fixed‐effect model. Results. For the primary outcome measures, no data was available for the LBR rate. There was a significantly higher chance of an ongoing pregnancy [OR = 1.44 (95% CI = 1.04–2.04)] and clinical pregnancy [OR = 1.55 (95% CI = 1.16–2.08)] with a full bladder. For the secondary outcomes, there was a significantly greater incidence of difficulty, or need for instrumental assistance, with an empty bladder. Other outcome measures were not significantly different. Conclusion. There is evidence in the literature advising to fill the bladder prior to embryo transfer.
Cystatin C, β‐2‐microglobulin and β‐trace protein in pre‐eclampsia
Authors: KRISTENSEN K. , WIDE‐SWENSSON D. , SCHMIDT C. , BLIRUP‐JENSEN S. , LINDSTRÖM V. , STREVENS H. , GRUBB A.
Published: July 2007

Background. An altered renal function is an essential component of the patho‐physiology of pre‐eclampsia. The plasma levels of low molecular mass proteins, e.g. β‐trace protein, β‐2‐microglobulin and cystatin C, are increased in the third trimester of normal pregnancy. The plasma levels of cystatin C and β‐2‐microglobulin are further increased in pre‐eclampsia, and the cystatin C level has been reported to be a reliable marker for the disease. The aim of this investigation was to study the plasma levels of β‐trace protein, β‐2‐microglobulin and cystatin C in pre‐eclampsia, and to determine the diagnostic performance of these proteins compared to that of urate and creatinine. Methods. A case‐control study of 57 women diagnosed with pre‐eclampsia, and 218 healthy women with uncomplicated singleton pregnancies in the third trimester. Women in the catchment area of Lund, Sweden, were included during an 18‐month period from October 2003 to April 2005. Venous blood samples were drawn upon inclusion when diagnosis was made. The maternal plasma concentrations of the 3proteins were analysed by automated particle‐enhanced immunoturbidimetric assays. Results. The plasma levels of the 3 proteins were significantly higher in the third trimester of pre‐eclamptic patients compared to healthy pregnant women in the third trimester. The upper reference limits (parametric 97.5 percentile) were 2.57mg/l for β‐2‐microglobulin, 0.72mg/l for β‐trace protein and 1.37mg/l for cystatin C. ROC analysis showed similar diagnostic performance for the 3 proteins, with β‐trace protein displaying the best diagnostic performance of all the analytes. Conclusions. In this study, the maternal plasma levels of β2‐microglobulin, β‐trace protein and cystatin C were all significantly elevated in pre‐eclampsia compared to those of healthy pregnant women, and displayed similar diagnostic performance for diagnosing pre‐eclampsia. The results indicate that low molecular mass proteins are useful as markers of renal impairment in pre‐eclampsia.
The use of atosiban and ritodrine in external cephalic version
Authors: STERGIOTOU IOSIFINA , TALBOT FLEUR , YOONG WAI
Published: July 2007

Objective. To compare the efficacy of atosiban and ritodrine as tocolytic agents for successful external cephalic version (ECV). Factors affecting the success of ECV, as well as maternal and perinatal outcomes are reviewed. Method. A retrospective review of women who underwent ECV with either atosiban (2004) or ritodrine (2002). Results. Atosiban and ritodrine were similarly effective (28 versus 41%, p>0.05). Side effects were more common with ritodrine. No significant adverse maternal and perinatal outcomes were recorded following procedures with either tocolytic. Conclusion. Atosiban is a safe choice for ECV with less maternal side effects. However, it is no more effective than ritodrine and the benefit of safety has to be balanced against that of cost.
Pregnancy and oral health: utilisation of dental services during pregnancy in northern Greece
Authors: DINAS KONSTANTINOS , ACHYROPOULOS VASSILIOS , HATZIPANTELIS EMMANOUEL , MAVROMATIDIS GEORGIOS , ZEPIRIDIS LEONIDAS , THEODORIDIS THEODOROS , DOVAS DIMITRIOS , TANTANASIS THEOHARIS , GOUTZIOULIS FOTIOS , BONTIS JOHN
Published: July 2007

Background. Recent studies have shown that gingivitis and periodontal infection during pregnancy represent an independent risk factor for pre‐term birth. However, little is known about the prevalence and correlates of dental attendance during pregnancy. Methods. During the first 3 days postpartum, an anonymous questionnaire was administered to 425 women in order to explore their dental condition and utilisation of dental health services during pregnancy, as well as their perceptions on the potential associations between dental care during pregnancy and pregnancy outcomes. Results. Almost half of the respondents (46.8%) reported symptoms of gingivitis during their pregnancy. Pregnancy gingivitis was independently associated with non‐Greek ethnicity (p = 0.008), multiparity versus primiparity (p<0.005), lower economic class versus middle and upper classes (p = 0.001), and the lack of routine primary dental care (p = 0.005). Some 27.3% reported a visit to the dentist during their pregnancy. The majority (72.2%) believed that dental treatment during pregnancy might have a negative affect on pregnancy outcome. The presence of pregnancy gingivitis and the belief that dental treatment during pregnancy is safe were both independently associated with visiting a dentist during pregnancy (p<0.0005 for both). Conclusions. Despite the increased prevalence of dental problems among pregnant women, few women seek dental services in this population, which can be primarily attributed to women's erroneous beliefs regarding the safety of dental examination. Therefore, there is an imperative need to offer oral health education and develop preventive programs for women of reproductive age.
Human papillomavirus‐type predict the clinical outcome of imiquimod therapy for women with vulvar condylomata acuminata*
Authors: DEDE MURAT , KUBAR AYHAN , YENEN MUFIT CEMAL , ALANBAY IBRAHIM , GUVEN SULEYMAN , MESTEN ZEKI , BASER ISKENDER
Published: July 2007

Objective. To investigate the effect of determination of human papillomavirus (HPV) subtype on the success of imiquimod therapy in women with vulvar condylomata acuminata. Methods. A total of 132 women with biopsy‐proven vulvar condylomata acuminata were enrolled in this prospective study. HPV DNA detection and determination of genotype were made through polymerase chain reaction (PCR) technique. The women were treated with imiquimod cream 5% in the area of the visible lesions, three times a week at night for 16 weeks. Results. Twelve of the 132 women (9.1%) failed to detect any improvement with this therapy during the 16‐week period. However, 80 women (60.6%) experienced total clearance of the lesions, and 20 women (15.2%) observed a partial response. The complete response rates were 76.2% for HPV‐6, 66.7% for HPV‐11, 35% for HPV‐6 plus 11, and 6.3% for unclassified HPV subtypes (other HPV subtypes than HPV 6 and ‐11). Conclusions. Topical imiquimod 5% cream is an appropriate treatment modality for HPV‐6 or ‐11 positive vulvar warts.
The genetic predisposition to produce high levels of TGF‐β1 impacts on the severity of eclampsia/pre‐eclampsia
Authors: STANCZUK GRAZYNA A. , MCCOY MELANIE J. , HUTCHINSON IAN V. , SIBANDA ELOPY N.
Published: July 2007

Objectives. To investigate the hypothesis that women who are genetically programmed to produce higher levels of transforming growth factor‐beta 1 are more likely to develop severe eclampsia/pre‐eclampsia. Design. Case–control study. Methods. Blood samples from women whose pregnancy was complicated by eclampsia (n = 37) or pre‐eclampsia (n = 49) and healthy controls (n = 86) were analyzed for the presence of polymorphisms at codons 10 and 25 of the transforming growth factor‐beta 1 gene. The polymorphisms are thought to determine whether an individual produces low, medium, or high levels of the cytokine. The analysis was carried out using the ARMS‐PCR technique. Results. Women who developed eclampsia/pre‐eclampsia with severe renal and neurological complications or had neonatal deaths/still births were more likely to have the high‐producer allele T in codon 10 of the transforming growth factor‐beta 1 gene than healthy controls. By contrast, the transforming growth factor‐beta 1 producer genotype and allele frequency as determined by gene polymorphisms at codon 25 were comparable in cases and controls. The cytokine producer status per se appears to had no bearing on whether a patient developed eclampsia/pre‐eclampsia. Conclusions. Our findings suggest that women who experience eclampsia/pre‐eclampsia with severe maternal and/or fetal complications are more likely to have a genetic predisposition to produce high levels of transforming growth factor‐beta 1 as defined by polymorphisms at codon 10. While it is recognized that eclampsia/pre‐eclampsia has heterogenous pathomechanisms, we have demonstrated a strong relationship between poor maternal and pregnancy outcomes and codon 10 polymorphisms. The characterization of the immunogenetic make‐up of the women may be an additional tool in the differentiation of component pathologies and/or prediction of severity of the syndrome.
Differential expression of nestin in normal and pre‐eclamptic human placentas
Authors: HWANG HAN‐SUNG , CHO NAM‐HOON , MAENG YONG‐SUN , KANG MYUNG‐HWA , PARK YONG‐WON , KIM YOUNG‐HAN
Published: July 2007

Background. Nestin is a type VI intermediate filament protein originally described in neural stem cells. Recent reports have documented nestin expression in endothelium of newly formed blood vessels and suggested its role as a marker of capacity for neovascularization and angiogenesis in endothelial cells. The aim of this study was to investigate the differential expression of nestin in normal and pre‐eclamptic human placentas. Methods. Placental tissues from 12 women with severe pre‐eclampsia and 15 gestational age‐matched normotensive women were collected at the time of their cesarean section. Western blot analysis for each placental tissue was performed for nestin quantification. Immunohistochemical staining was employed to localize nestin‐positive cells and to investigate differential staining intensity in each placental cell. Results. Nestin expression was detected in all of the normal and pre‐eclamptic placental tissues by Western blotting. Compared with the normal placentas, tissues from severe pre‐eclamptic placentas showed higher expression of nestin (p<0.001). Nestin immunoreactivity was localized only to endothelial cells of chorionic villi. However, mesenchymal connective tissue cells, cytotrophoblasts, syncytiotrophoblasts, and decidual cells did not reveal any specific signal for nestin. Conclusions. We suggest that the capacity for neovascularization and angiogenesis in endothelial cell is increased in pre‐eclamptic placenta compared to that from normal pregnancy. Such changes may be a compensatory mechanism for the reduced maternofetal exchanges and long‐lasting fetal hypoxia in pre‐eclamptic pregnancy. Furthermore, these changes in endothelial cells of chorionic villi in pre‐eclamptic pregnancy may give an explanation for fetal response to pre‐eclamptic conditions.
Prevalence and genotyping of human papillomavirus infection in women with vulvodynia
Authors: ORLANDI AUGUSTO , FRANCESCONI ARIANNA , ANGELONI CATERINA , PALMIERI GIAMPIERO , FULVIA GLORIA , CIOTTI MARCO , CRISCUOLO ANNA , SESTI FRANCESCO , SPAGNOLI LUIGI GIUSTO
Published: July 2007

Background. Evidence of vulvar human papillomavirus infection varies and the frequency of the different genotypes has not been adequately assessed. Methods. Fifty consecutive sexually active healthy patients with vulvodynia and suspected of human papillomavirus infection underwent a vulvoscopy and biopsy. Ten normal vulvar samples were also enrolled as control. Histological and vulvoscopic findings were compared in relation to human papillomavirus‐DNA presence and genotyping by a broad‐spectrum polymerase chain reaction and reverse hybridization line probe assay. Results. Although the clinical and histological diagnoses did not always coincide, a good association was found (p<0.0001). Human papillomavirus‐DNA was detected in 42% of all biopsies and in none of the controls, and less frequently in acetowhite‐positive patients (33.3%, p<0.03). Squamous papillomatosis (74%) was the most frequent histological diagnosis, followed by condyloma (20%). Condyloma (90%) but not squamous papillomatosis (29.7%) was significantly associated with human papillomavirus‐DNA presence. Out of the vulvoscopically normal patients, one (33%) was human papillomavirus‐DNA positive. Out of the recorded microscopic features, only koilocytosis was associated with human papillomavirus‐DNA presence. Eight different human papillomavirus genotypes were detected: high‐risk 16 (43%), 31 (19%), 52 (14.3%), 68, and 59 (4.8% each), and low‐risk types 6 (71.4%), 11, and 40 (4.8% each); 33.3% of infections were multiple, ranging from 2 to 4 genotypes. Out of the human papillomavirus‐DNA positive squamous papillomatosis, 72.7% showed a high‐risk type but the infection remained episomal. Conclusions. Our data confirm human papillomavirus as a frequent cause of vulvodynia and its frequent association with squamous papillomatosis or condyloma. The high‐risk human papillomavirus in squamous papillomatosis suggests screening for possible undiagnosed cervical infection.
Level of S100B protein expression in the amnion at various gestational ages in the third trimester of normal pregnancies
Authors: TSKITISHVILI EKATERINE , KOMOTO YOSHIKO , KINUGASA YUKIKO , KANAGAWA TAKESHI , SONG MIHYON , MIMURA KAZUYA , TOMIMATSU TAKUJI , KIMURA TADASHI , SHIMOYA KOICHIRO
Published: July 2007

Background. S100B protein is a unique calcium‐binding protein. Its biological role within the cell populations is not completely defined. Some pathological conditions that develop during pregnancy could affect S100B concentrations in the amniotic fluid, cord blood, and maternal serum. The aim of our study was to assess the correlation between S100B protein expression in the amnion, amniotic fluid and gestational age in the third trimester of uncomplicated pregnancies.Methods. Amnion, amniotic fluid, maternal peripheral and umbilical cord blood samples were collected from healthy women who delivered at 31–36 weeks (n= 17), 37–40 weeks (n= 22), and 41–42 weeks (n= 21). The expression of S100B in the amnion was assessed by immunohistochemistry and real‐time (RT)‐PCR, and its concentrations in amniotic fluid, maternal and cord blood sera were determined by ELISA.Results. The S100B protein expression in the amnion and its concentrations in amniotic fluid, maternal and cord blood sera of patients in the third trimester were not significantly different at various gestational ages.Conclusions. The S100B protein expression in the amnion and the S100B protein concentrations in amniotic fluid, maternal and cord blood do not vary significantly in the third trimester of uncomplicated pregnancies.
Serum resistin level is a predictor of ovarian response in in vitro fertilisation cycle
Authors: CHEN YU‐CHIEH , TSAI EING‐MEI , CHEN HUNG‐SHENG , LIU YUNG‐HSIEN , LEE CHIEN‐HUNG , CHOU FAN‐HAO , CHEN I‐JU , CHEN SU‐YIN , JONG SHIANG‐BIN , CHAN TE‐FU
Published: July 2007

Objectives. To measure serum resistin levels in infertile women undergoing in vitro fertilisation‐embryo transfer (IVF‐ET), and to find any correlations between serum resistin levels and body weight, body mass index, the number of oocytes retrieved, and the outcome of IVF‐ET. In addition, to assess whether there is any difference in serum resistin levels between infertility caused by polycystic ovary syndrome (PCOS) and infertility caused by other female factors. Methods. We designed a case‐control study, and a total of 44 infertile women were enrolled. The blood samples for resistin measurement were collected on day 3 of the menstrual cycle prior to the administration of gonadotropin during in vitro fertilisation. These cases were then divided into 2 subgroups (PCOS group versus non‐PCOS group) and a number of variables were measured and compared, including serum resistin levels. Results. Serum resistin levels were inversely correlated with the number of oocytes retrieved (r = −0.371, p = 0.013). No significant correlation was found between serum resistin levels and body mass index or body weight, either in the whole group or in the 2 subgroups. Serum resistin levels in the non‐PCOS group were significantly higher than in the PCOS group (p = 0.049). Serum resistin levels in the non‐PCOS group were inversely correlated to the number of oocytes retrieved (r = −0.386, p = 0.039), but no similar correlation was found in the PCOS group. There was no correlation between serum resistin levels and fertility rate or clinical pregnancy rate in either subgroup. Conclusions. We observed a negative correlation between serum resistin levels and the number of oocytes retrieved during IVF. However, this phenomenon was only present in the non‐PCOS group. This result suggests that serum resistin levels might be a good predictor of ovarian response in infertile women without PCOS during IVF. The role of serum resistin in response to inflammation caused by endometriosis or chronic pelvic infection, both of which are major causes of female infertility, should be examined in a further study.
Outcome of site‐specific fascia repair for rectocele
Authors: SARDELI CHRYSANTHI , AXELSEN SUSANNE M. , KJÆR DANIEL , BEK KARL M.
Published: July 2007

Background. This article presents the anatomic and functional outcome of site‐specific fascia repair for rectocele performed under local anesthesia. Methods. In this case series, 51 consecutive patients underwent site‐specific rectocele repair under local anesthesia. Patients were subsequently reviewed in the outpatient clinic. Results. The mean follow‐up period was 26.7 months. Pelvic examination revealed recurrence of posterior vaginal wall prolapse in 31% (16/51). Improvement in emptying the rectum was achieved in 23% (7/30), and 23% (7/30) were relieved from constipation. One patient developed de novo dyspareunia. Some 92% of the patients (47/51) would recommend local anesthesia. Conclusions. Anatomic correction of posterior vaginal wall prolapse does not guarantee alleviation of all symptoms, especially those regarding defecation; however, postoperative dyspareunia levels are low. The use of local anesthesia is associated with high patient satisfaction. Patients should be informed that total recovery from accompanying subjective symptoms cannot be guaranteed.
A randomised, double‐blind, placebo‐controlled trial on the effect of Pycnogenol® on the climacteric syndrome in peri‐menopausal women
Authors: YANG HAN‐MING , LIAO MEI‐FEN , ZHU SHU‐YUAN , LIAO MEI‐NAN , ROHDEWALD PETER
Published: July 2007

Background. French maritime pine bark extract (Pycnogenol®) was found to alleviate menstrual pain and reduce hyperactivity in clinical studies. These results suggest the possibility to observe positive effects in treating climacteric syndrome. Objective. Clinical investigation of the effect of Pycnogenol®, French maritime pine bark extract, on the climacteric syndrome. Methods. Some 200 peri‐menopausal women were enrolled in a double‐blind, placebo‐controlled study, and treated with Pycnogenol® (200mg) daily. Climacteric symptoms were evaluated by the Women's Health Questionnaire (WHQ), patients were checked for antioxidative status and routine chemistry. A total of 155women completed the study. Results. All climacteric symptoms improved, antioxidative status increased and LDL/HDL ratio was favourably altered by Pycnogenol®. No side effects were reported. Conclusion. Pycnogenol® may offer an alternative method to reducing climacteric symptoms without unwanted effects.