bluuebunny/crossref_metadata_2025 huggingface dataset:
High quantum efficiency of violet-blue to green light emission in InGaN quantum well structures grown by graded-indium-content profiling method
Authors: Cho Yong-Hoon , Sun Y. P. , Kim H. M. , Kang T. W. , Suh E.-K. , Lee H. J. , Choi R. J. , Hahn Y. B.
Published: January 2007

Optical characteristics of high-efficiency violet-blue, blue, and green light emissions in InxGa1−xN quantum well (QW) structures with graded In content are investigated. Appearance of additional higher energy peaks at 410, 429, and 459nm above the main peaks at 430, 463, and 509nm with an effective carrier transfer from the higher to main peak sides is characteristic of these structures with various In contents of x<0.2, 0.2<x<0.3, and x>0.3, respectively. Robust carrier localization by uniform, small-size, and high-density phase segregation plays an important role in maintaining high efficiencies over a wide range of In contents in graded-In-content InGaN QW structures.
Ultrathin Si capping layer suppresses charge trapping in HfOxNy∕Ge metal-insulator-semiconductor capacitors
Authors: Cheng Chao-Ching , Chien Chao-Hsin , Luo Guang-Li , Yang Chun-Hui , Kuo Mei-Ling , Lin Je-Hung , Chang Chun-Yen
Published: January 2007

In this study the authors investigated the Ge outdiffusion characteristics of HfOxNy∕Ge metal-insulator-semiconductor capacitors to determine their charge trapping behavior. Capping the Ge substrate with an ultrathin Si layer inhibits the incorporation of Ge into the high-k bulk dielectric in the form of GeOx, thereby diminishing the resultant oxide charge trapping. The thermal stability of the entire capacitor structure was also improved after performing an additional Si passivation process.
Improved ferroelectric properties of bismuth titanate films by Nd and Mn cosubstitution
Authors: Zhong X. L. , Wang J. B. , Sun L. Z. , Tan C. B. , Zheng X. J. , Zhou Y. C.
Published: January 2007

Thin films of Nd and Mn cosubstituted bismuth titanate, i.e., Bi3.15Nd0.85(Ti3−xMnx)O12 (BNTM) (x=0, 0.005, 0.01, 0.03, 0.05, and 0.1), were fabricated on Pt∕Ti∕SiO2∕Si(100) substrates at 700°C by a chemical solution deposition technique. The structures of the films were analyzed using x-ray diffraction and Raman spectroscopy. These films possessed preferred (117) and (00l)-oriented polycrystalline structures. The ferroelectric properties of BNTM films were systematically investigated as a function of the Mn content. It is found that a low concentration substitution with manganese ions in Bi3.15Nd0.85Ti3O12 greatly enhances the remnant polarization (2Pr) and reduces the coercive field (2Ec) of the film. The 2Pr and 2Ec are 78μC∕cm2 and 205kV∕cm, respectively. No fatigue phenomenon is also observed for the BNTM film with x=0.01 up to 1.5×1010 switching cycles.
Electric-field-induced structural modulation of epitaxial BiFeO3 multiferroic thin films as studied using x-ray microdiffraction
Authors: Bark Chung W. , Ryu Sangwoo , Koo Yang M. , Jang Hyun M. , Youn Hwa S.
Published: January 2007

An in situ method, called synchrotron x-ray microdiffraction, was introduced to examine the electric-field-induced structural modulation of the epitaxially grown pseudotetragonal BiFeO3 thin film. To evaluate the d spacing (d001) from the measured intensity contour in the 2θ-χ space, the peak position in each diffraction profile was determined by applying two-dimensional Lorentzian fitting. By tracing the change of d spacing as a function of the applied electric field and by examining the Landau free energy function for P4mm symmetry, the authors were able to estimate the two important parameters that characterize the field-induced structural modulation. The estimated linear piezoelectric coefficient (d33) at zero-field limit is 15pm∕V, and the effective nonlinear electrostrictive coefficient (Qeff) is as low as ∼8.0×10−3m4∕C2.
Impurity mediated absorption continuum in single-walled carbon nanotubes
Authors: Zhang C. , Cao J. C. , Guo X. G. , Liu Feng
Published: January 2007

The authors demonstrate that in single-walled carbon nanotubes, a weak impurity potential can lead to a strong above-gap absorption continuum. The total absorption is enhanced due to the intraband and indirect transitions, as well as plasmon excitations, which are forbidden in perfect nanotubes. Such impurity induced absorption is strongly dependent on the size and chirality of the tube.
Change in electrical resistance and thermal stability of nitrogen incorporated Ge2Sb2Te5 films
Authors: Kim YoungKuk , Hwang Uk , Cho Yong Jai , Park H. M. , Cho M.-H. , Cho Pyeong-Seok , Lee Jong-Heun
Published: January 2007

Changes in the electrical resistance of nitrogen incorporated Ge2Sb2Te5 (NGST) films were investigated as a function of nitrogen content by four-point probe and ac two-point probe methods. Some nitrogen is initially located inside the cubic structure, resulting in a significant increase in crystalline temperature and electrical resistance. As the amount of incorporated nitrogen increases, excess nitrogen accumulates in the grain boundaries, which does not contribute substantially to the increase in electrical resistance and the crystallization temperature. The supersaturated nitrogen distorts the Ge2Sb2Te5 structure, resulting in a NGST film with a structure that is different from the metastable fcc structure. X-ray absorption spectroscopy revealed that Ge–N and N2 molecular states were present in the film and gradually increased in proportion to the amount of incorporated nitrogen. Moreover, the nitrogen states were very stably maintained even during the phase transition process.
Electronic structure and field emission properties of in situ potassium-doped single-walled carbon nanotubes
Authors: Ha Byeongchul , Lee Cheol Jin
Published: January 2007

In situ potassium (K)-doped single-walled carbon nanotube (SWCNT) was synthesized using a hydrogen arc-discharge method. X-ray photoelectron spectroscopy analysis showed that the K-doped SWCNTs consisted of 0.12% K mass composition. The K-doped SWCNTs showed the lower turn-on electric field of 2.0V∕μm at a current density of 10−9A∕cm2 and the higher emission current density of 3.0mA∕cm2 at an applied field of 4.6V∕μm compared with the undoped SWCNTs. The improved field emission performance of K-doped SWCNTs was mainly attributed to the decreased work function and the increased density of state near the Fermi energy.
Effect of interface layer, curing temperature, and polarization on the hole transport in poly(3-hexylthiophene) thin films
Authors: Kumar Pankaj , Chand Suresh , Dwivedi S. , Kamalasanan M. N.
Published: January 2007

The effect of interface barrier, curing temperature, and polarization on the charge transport in regioregular poly(3-hexyl-thiophene) (RR-P3HT) has been investigated in the hole only ITO/poly(ethylene-dioxy-thiophene):polystyrenesulphonate(PEDOT:PSS)/RR-P3HT/Au diode structure. Incorporation of PEDOT:PSS interface layer enhances hole injection into RR-P3HT and switches the conduction from ohmic to space charge limited. Curing temperature ∼120°C was found optimum for RR-P3HT where the intrinsic defects are minimum. The polarization effect in RR-P3HT results in making traps shallower, i.e., the characteristic trap depth reduces from 39to23meV. Hole transport through RR-P3HT has been explained by trap model with traps distributed exponentially in energy space.
Ga
∕
Au
alloy catalyst for single crystal silicon-nanowire epitaxy
Authors: Lugstein A. , Steinmair M. , Hyun Y. J. , Bertagnolli E. , Pongratz P.
Published: January 2007

Epitaxial growth of single crystalline silicon nanowires along the ⟨111⟩ directions was obtained on Si (100) and Si (111) substrates by gold-gallium-nanoparticle-catalyzed chemical vapor deposition with a SiH4 precursor. In comparison to the pure gold catalyst, the proportion of the nanowires growing perpendicular to the substrate is much higher and the wires show almost no kinks. The average diameter is smaller, and the diameter and length distributions are narrowly dispersed. By making a particular choice of growth conditions, it is possible to realize either rodlike or tapered silicon nanowires, which may be desirable for applications as field emitters.
Enhanced magnetoelectric effects in composite of piezoelectric ceramics, rare-earth iron alloys, and ultrasonic horn
Authors: Li Ping , Wen Yumei , Bian Leixiang
Published: January 2007

A magnetoelectric (ME) composite consisting of a copper ultrasonic horn, a magnetostrictive Terfenol-D (TbxDy1−xFe2) plate, and multiple piezoelectric PZT [Pb(Zr1−xTix)O3] plates has been developed. The ultrasonic horn converges and amplifies the vibrating magnitude and drives PZT plates at wide bandwidth. The composite with multiple PZT plates electrically connected in series/parallel exhibits a 25 times higher ME voltage coefficient than the previous laminate composite of PZT and Terfenol-D plates. 100 times higher ME voltage coefficients can be obtained by using a silicon horn composite with a higher Q value of 104 and more PZT plates of ten electrically connected in series/parallel.
Strain relaxation in nanopatterned strained silicon round pillars
Authors: Himcinschi C. , Singh R. , Radu I. , Milenin A. P. , Erfurth W. , Reiche M. , Gösele U. , Christiansen S. H. , Muster F. , Petzold M.
Published: January 2007

Periodic arrays of strained Si (sSi) round nanopillars were fabricated on sSi layers deposited on SiGe virtual substrates by electron-beam lithography and subsequent reactive-ion etching. The strain in the patterned sSi nanopillars was determined using high-resolution UV micro-Raman spectroscopy. The strain relaxes significantly upon nanostructuring: from 0.9% in the unpatterned sSi layer to values between 0.22% and 0.57% in the round sSi pillars with diameters from 100 up to 500nm. The strain distribution in the sSi nanopillars was analyzed by finite element (FE) modeling. The FE calculations confirm the strain relaxation after patterning, in agreement with the results obtained from Raman spectroscopy.
Lamb waves in plates covered by a two-dimensional phononic film
Authors: Bonello Bernard , Charles Christine , Ganot François
Published: January 2007

The propagation of Lamb waves in silicon plates coated by a very thin two-dimensional phononic film is studied experimentally. The dispersion curves are measured using a laser ultrasonics technique. The data are then compared to the calculated dispersion curves of the uncoated silicon plate. The overall shapes of the lower-order symmetric and antisymmetric Lamb modes are not altered by the thin phononic film, except by the appearing of frequency band gaps at the edges of both the first and the second Brillouin zone. The influence of the filling fraction on the magnitude of the gaps is investigated experimentally.
High thermally stable Ni∕Ag(Al) alloy contacts on p-GaN
Authors: Chou C. H. , Lin C. L. , Chuang Y. C. , Bor H. Y. , Liu C. Y.
Published: January 2007

Ag agglomeration was found to occur at Ni∕Ag to p-GaN contacts after annealing at 500°C. This Ag agglomeration led to the poor thermal stability showed by the Ni∕Ag contacts in relation to the reflectivity and electrical properties. However, after alloying with 10at.% Al by e-gun deposition, the Ni∕Ag(Al) p-GaN contacts were found to effectively retard Ag agglomeration thereby greatly enhancing the thermal stability. Based on the x-ray photoelectron spectroscopy analysis, the authors believe that the key for the retardation of Ag agglomeration was the formation of ternary Al–Ni–O layer at p-GaN interface.
Noise can play an organizing role for the recurrent dynamics in excitable media
Authors: Muratov Cyrill B. , Vanden-Eijnden Eric , E Weinan
Published: January 2007

We analyze patterns of recurrent activity in a prototypical model of an excitable medium in the presence of noise. Without noise, this model robustly predicts the existence of spiral waves as the only recurrent patterns in two dimensions. With small noise, however, we found that this model is also capable of generating coherent target patterns, another type of recurrent activity that is widely observed experimentally. These patterns remain essentially deterministic despite the presence of the noise, yet their existence is impossible without it. Their degree of coherence can also be made arbitrarily high for wide ranges of the parameters, which does not require fine-tuning. Our findings demonstrate the need to reexamine current modeling approaches to active biological media.
Baf60c is a nuclear Notch signaling component required for the establishment of left–right asymmetry
Authors: Takeuchi Jun K. , Lickert Heiko , Bisgrove Brent W. , Sun Xin , Yamamoto Masamichi , Chawengsaksophak Kallayanee , Hamada Hiroshi , Yost H. Joseph , Rossant Janet , Bruneau Benoit G.
Published: January 2007

Notch-mediated induction of Nodal at the vertebrate node is a critical step in initiating left–right (LR) asymmetry. In mice and zebrafish we show that Baf60c, a subunit of the Swi/Snf-like BAF chromatin remodeling complex, is essential for establishment of LR asymmetry. Baf60c knockdown mouse embryos fail to activate
Nodal
at the node and also have abnormal node morphology with mixing of crown and pit cells. In cell culture, Baf60c is required for Notch-dependent transcriptional activation and functions to stabilize interactions between activated Notch and its DNA-binding partner, RBP-J. Brg1 is also required for these processes, suggesting that BAF complexes are key components of nuclear Notch signaling. We propose a critical role for Baf60c in Notch-dependent transcription and LR asymmetry.
Bovine viral diarrhoea virus infection in livestock in southern Africa.
Authors: Vuuren M. van
Published: January 2007

Bovine viral diarrhoea virus (BVDV) is viewed as an economically important pathogen of cattle in southern Africa. During the last decade, a high priority was given to the diagnosis and control of BVDV-associated diseases, which was evident from the attention it received at conferences and meetings of both practitioners and producers. The presence of BVDV in southern Africa has been known since the early 1970s through serological surveys but only a few documented reports confirming its presence through virus isolation and correlation with clinical disease are available. Of the clinical signs in cattle from which virus was isolated, respiratory signs were the most frequent, followed by diarrhoea. Bovine viral diarrhoea viruses obtained by isolation in tissue culture or detected by means of antigen capture ELISA from clinically sick cattle were characterized on the basis of analysis of the 5′-non-translated (5′-NTR) region of the genome. All the BVDV strains analysed belong to subgroups of BVDV genotype 1. No association could be demonstrated between the geographic origins of the isolates. The findings suggest that an extensive genetic diversity can be found within BVDV type 1 isolates from southern Africa. Isolates that group with the classical BVDV type 1 strains, particularly of American origin, coexist with variants that appear to represent a local genetic pool and/or variants evolving from the classical strains.
Agrobiotechnology and biosafety in Colombia.
Authors: Jaramillo E. H. de , Carrizosa M. S.
Published: January 2007

This paper provides a general overview of agrobiotechnology and biosafety development in Colombia. It outlines agrobiotechnology policies, priorities and development strategies in Colombia, as well as research capacities. A description of the evolution of biosafety regulations and legislation in force in the country is also included. As an important implementation part of the Cartagena PROTOCOL in Colombia, the GEF-WB Colombian Biosafety project 'Capacity Building for Implementation of the Cartagena PROTOCOL in Colombia' is briefly described.
Novel cell death program leads to neutrophil extracellular traps
Authors: Fuchs Tobias A. , Abed Ulrike , Goosmann Christian , Hurwitz Robert , Schulze Ilka , Wahn Volker , Weinrauch Yvette , Brinkmann Volker , Zychlinsky Arturo
Published: January 2007

Neutrophil extracellular traps (NETs) are extracellular structures composed of chromatin and granule proteins that bind and kill microorganisms. We show that upon stimulation, the nuclei of neutrophils lose their shape, and the eu- and heterochromatin homogenize. Later, the nuclear envelope and the granule membranes disintegrate, allowing the mixing of NET components. Finally, the NETs are released as the cell membrane breaks. This cell death process is distinct from apoptosis and necrosis and depends on the generation of reactive oxygen species (ROS) by NADPH oxidase. Patients with chronic granulomatous disease carry mutations in NADPH oxidase and cannot activate this cell-death pathway or make NETs. This novel ROS-dependent death allows neutrophils to fulfill their antimicrobial function, even beyond their lifespan.
Puf3p, a Pumilio family RNA binding protein, localizes to mitochondria and regulates mitochondrial biogenesis and motility in budding yeast
Authors: García-Rodríguez Luis J. , Gay Anna Card , Pon Liza A.
Published: January 2007

Puf3p binds preferentially to messenger RNAs (mRNAs) for nuclear-encoded mitochondrial proteins. We find that Puf3p localizes to the cytosolic face of the mitochondrial outer membrane. Overexpression of PUF3 results in reduced mitochondrial respiratory activity and reduced levels of Pet123p, a protein encoded by a Puf3p-binding mRNA. Puf3p levels are reduced during the diauxic shift and growth on a nonfermentable carbon source, conditions that stimulate mitochondrial biogenesis. These findings support a role for Puf3p in mitochondrial biogenesis through effects on mRNA interactions. In addition, Puf3p links the mitochore, a complex required for mitochondrial–cytoskeletal interactions, to the Arp2/3 complex, the force generator for actin-dependent, bud-directed mitochondrial movement. Puf3p, the mitochore, and the Arp2/3 complex coimmunoprecipitate and have two-hybrid interactions. Moreover, deletion of PUF3 results in reduced interaction between the mitochore and the Arp2/3 complex and defects in mitochondrial morphology and motility similar to those observed in Arp2/3 complex mutants. Thus, Puf3p is a mitochondrial protein that contributes to the biogenesis and motility of the organelle.
The AAA+ protein ATAD3 has displacement loop binding properties and is involved in mitochondrial nucleoid organization
Authors: He Jiuya , Mao Chih-Chieh , Reyes Aurelio , Sembongi Hiroshi , Di Re Miriam , Granycome Caroline , Clippingdale Andrew B. , Fearnley Ian M. , Harbour Michael , Robinson Alan J. , Reichelt Stefanie , Spelbrink Johannes N. , Walker John E. , Holt Ian J.
Published: January 2007

Many copies of mammalian mitochondrial DNA contain a short triple-stranded region, or displacement loop (D-loop), in the major noncoding region. In the 35 years since their discovery, no function has been assigned to mitochondrial D-loops. We purified mitochondrial nucleoprotein complexes from rat liver and identified a previously uncharacterized protein, ATAD3p. Localization studies suggested that human ATAD3 is a component of many, but not all, mitochondrial nucleoids. Gene silencing of ATAD3 by RNA interference altered the structure of mitochondrial nucleoids and led to the dissociation of mitochondrial DNA fragments held together by protein, specifically, ones containing the D-loop region. In vitro, a recombinant fragment of ATAD3p bound to supercoiled DNA molecules that contained a synthetic D-loop, with a marked preference over partially relaxed molecules with a D-loop or supercoiled DNA circles. These results suggest that mitochondrial D-loops serve to recruit ATAD3p for the purpose of forming or segregating mitochondrial nucleoids.
The Golgi-resident protease Kex2 acts in conjunction with Prm1 to facilitate cell fusion during yeast mating
Authors: Heiman Maxwell G. , Engel Alex , Walter Peter
Published: January 2007

The molecular machines that mediate cell fusion are unknown. Previously, we identified a multispanning transmembrane protein, Prm1 (pheromone-regulated membrane protein 1), that acts during yeast mating (Heiman, M.G., and P. Walter. 2000. J. Cell Biol. 151:719–730). Without Prm1, a substantial fraction of mating pairs arrest with their plasma membranes tightly apposed yet unfused. In this study, we show that lack of the Golgi-resident protease Kex2 strongly enhances the cell fusion defect of Prm1-deficient mating pairs and causes a mild fusion defect in otherwise wild-type mating pairs. Lack of the Kex1 protease but not the Ste13 protease results in similar defects. Δkex2 and Δkex1 fusion defects were suppressed by osmotic support, a trait shared with mutants defective in cell wall remodeling. In contrast, other cell wall mutants do not enhance the Δprm1 fusion defect. Electron microscopy of Δkex2-derived mating pairs revealed novel extracellular blebs at presumptive sites of fusion. Kex2 and Kex1 may promote cell fusion by proteolytically processing substrates that act in parallel to Prm1 as an alternative fusion machine, as cell wall components, or both.
Dendritic cell–expanded, islet-specific CD4+ CD25+ CD62L+ regulatory T cells restore normoglycemia in diabetic NOD mice
Authors: Tarbell Kristin V. , Petit Lucine , Zuo Xiaopan , Toy Priscilla , Luo Xunrong , Mqadmi Amina , Yang Hua , Suthanthiran Manikkam , Mojsov Svetlana , Steinman Ralph M.
Published: January 2007

Most treatments that prevent autoimmune diabetes in nonobese diabetic (NOD) mice require intervention at early pathogenic stages, when insulitis is first developing. We tested whether dendritic cell (DC)–expanded, islet antigen–specific CD4+ CD25+ suppressor T cells could treat diabetes at later stages of disease, when most of the insulin-producing islet β cells had been destroyed by infiltrating lymphocytes. CD4+ CD25+ CD62L+ regulatory T cells (T reg cells) from BDC2.5 T cell receptor transgenic mice were expanded with antigen-pulsed DCs and IL-2, and were then injected into NOD mice. A single dose of as few as 5 × 104 of these islet-specific T reg cells blocked diabetes development in prediabetic 13-wk-old NOD mice. The T reg cells also induced long-lasting reversal of hyperglycemia in 50% of mice in which overt diabetes had developed. Successfully treated diabetic mice had similar responses to glucose challenge compared with nondiabetic NOD mice. The successfully treated mice retained diabetogenic T cells, but also had substantially increased Foxp3+ cells in draining pancreatic lymph nodes. However, these Foxp3+ cells were derived from the recipient mice and not the injected T reg cells, suggesting a role for endogenous T reg cells in maintaining tolerance after treatment. Therefore, inoculation of DC-expanded, antigen-specific suppressor T cells has considerable efficacy in ameliorating ongoing diabetes in NOD mice.
Nuclear magnetic ordering in metals
Authors: Frank Pobell
Published: January 2007

Spontaneous nuclear magnetic ordering is discussed for the following two groups of metals:

1. Metals where the nuclear-electron interaction is so weak that the nuclear spin temperature can be reduced substantially below the electronic and lattice temperatures and where this temperature difference can be kept for a time sufficiently long to perform investigations of the "isolated" nuclear spin system. By this method, nuclear magnetic ordering in Ag and Cu has been observed at nanokelvin nuclear spin temperatures. Here I will also consider the interesting phenomena occurring at negative nuclear spin temperatures.

2. Metals where the nuclear-electron coupling is so strong that nuclei and electrons cannot be decoupled for an experimentally relevant time. For these groups of metals the complex NMR spectra of Tl as well as the recent observation of a spontaneous nuclear magnetic ordering transition of In nuclear spins in the cubic intermetallic compound AuIn2 at microkelvin temperatures will be reviewed.
Spurious counts and spurious results on haematology analysers: a review. Part I: platelets
Authors: ZANDECKI M. , GENEVIEVE F. , GERARD J. , GODON A.
Published: January 2007

The widespread use of haematology analysers (HA) has led to a major improvement of cellular haematology, because of quick and accurate results found in most instances. However, in several situations, spurious results are observed. Inadequate blood samples, situations induced by the anticoagulant(s) used, peculiar changes related to the pathology in the patient, and technical considerations about performances of the various HA must be considered. Spurious thrombocytopenia occurs in several circumstances related to the presence of ethylenediamine tetra‐acetic acid (EDTA) used as the anticoagulant. Mechanism of EDTA‐dependent platelet (PLT) agglutination is related to circulating (auto)antibodies directed against normally hidden epitope(s) in the glycoprotein alpha IIb/beta IIIa complex from PLT membrane exposed only in the presence of EDTA. Other spuriously low PLT counts may be related to EDTA, including PLT rosetting around white blood cells (WBC; satellitism) and PLT‐WBC aggregates, but mechanisms responsible for those latter phenomena are less well known. Spurious increase of PLT count may be related to several situations, including fragmented red blood cells, cytoplasmic fragments of nucleated cells, cryoglobulins, bacteria or fungi, and lipids. Flags generated in several of these situations alert the operator on possible abnormal findings and may identify the problem. Analysing only PLT parameters is not sufficient: in many situations the WBC differential scattergram is of crucial help for flagging. Flags generated depend on the software version on the HA used, the performance in detecting the same anomalies may differ according to which analyser is used, even those from the same manufacturer. Operators must be aware of the characteristics of their analyser and be able to recognize and circumvent anomalous results.
Characterization of polVR391: a Y‐family polymerase encoded by rumA′B from the IncJ conjugative transposon, R391
Authors: Mead Samantha , Vaisman Alexandra , Valjavec‐Gratian Majda , Karata Kiyonobu , Vandewiele Dominique , Woodgate Roger
Published: January 2007

Although best characterized for their ability to traverse a variety of DNA lesions, Y‐family DNA polymerases can also give rise to elevated spontaneous mutation rates if they are allowed to replicate undamaged DNA. One such enzyme that promotes high levels of spontaneous mutagenesis in Escherichia coli is polVR391, a polV‐like Y‐family polymerase encoded by rumA′B from the IncJ conjugative transposon R391. When expressed in a ΔumuDC lexA(Def) recA730 strain, polVR391 promotes higher levels of spontaneous mutagenesis than the related MucA′B (polR1) or UmuD′C (polV) polymerases respectively. Analysis of the spectrum of polVR391‐dependent mutations in rpoB revealed a unique genetic fingerprint that is typified by an increase in C:G→A:T and A:T→T:A transversions at certain mutagenic hot spots. Biochemical characterization of polVR391 highlights the exceptional ability of the enzyme to misincorporate T opposite C and T in sequence contexts corresponding to mutagenic hot spots. Purified polVR391 can also bypass a T‐T pyrimidine dimer efficiently and displays greater accuracy opposite the 3′T of the dimer than opposite an undamaged T. Our study therefore provides evidence for the molecular basis for the enhanced spontaneous mutator activity of RumA′B, as well as explains its ability to promote efficient and accurate bypass of T‐T pyrimidine dimers in vivo.
Detection of bacteria in platelet concentrates prepared from spiked single donations using cultural and molecular genetic methods
Authors: Störmer M. , Cassens U. , Kleesiek K. , Dreier J.
Published: January 2007

summary Bacteria show differences in their growth kinetics depending on the type of blood component. On to storage at 22 °C, platelet concentrates (PCs) seem to be more prone to bacterial multiplication than red cell concentrates. Knowledge of the potential for bacterial proliferation in blood components, which are stored at a range of temperatures, is essential before considering implementation of a detection strategy.

The efficacy of bacterial detection was determined, using real‐time reverse transcriptase–polymerase chain reaction (RT‐PCR), following bacterial growth in blood components obtained from a deliberately contaminated whole‐blood (WB) unit. Cultivation was used as the reference method. WB was spiked with 2 colony‐forming units mL−1Staphylococcus epidermidis or Klebsiella pneumoniae, kept for 15 h at room temperature and component preparation was processed. Samples were drawn, at intervals throughout the whole separation process, from each blood component. Nucleic acids were extracted using an automated high‐volume extraction method.

The 15‐h storage revealed an insignificant increase in bacterial titre. No bacterial growth was detected in red blood cell or plasma units. K. pneumoniae showed rapid growth in the pooled PC and could be detected immediately after preparation using RT‐PCR. S. epidermidis grew slowly and was detected 24 h after separation.

These experiments show that sampling is indicative at 24 h after preparation of PCs at the earliest to minimize the sampling error.
Blood bank protocols for large‐scale civilian casualty events: experience from terrorist bombing in Israel
Authors: Dann E. J. , Bonstein L. , Arbov L. , Kornberg A. , Rahimi‐Levene N.
Published: January 2007

summary Terrorist attacks in crowded places cause multiple casualties that are evacuated by quick succession to nearby hospitals. The study goals were to analyse the issues of patient misidentification and excessive blood request and to develop recommendations for the management of such episodes. A retrospective analysis of nine explosion attacks was performed. In nine consecutive events, 450 casualties were reported by the National Ambulance Service, 82 of whom (18%) died on the explosion site and 368 were admitted to nearby trauma centres. Red blood cell units were typed and cross‐matched for 70 patients. Seventy‐three per cent of the blood supplied over the first 24 h was administered during the first 2 h. The cross‐matched/transfused ratio was 2·52 ± 1·42, reflecting the overestimation of blood requirement in mass casualty episodes. In the mass casualty setup, blood bank personnel should be alert to a potential mistransfusion or a blood collection error. Unidentified patients are subjected to errors due to only one‐digit difference in their temporary identification number. Application of the system using an additional sequential four‐digit number printed in bold and large size font for patients at admission reduced the possibility of misidentification. Modern technologies, including error‐reduction design wristbands, barcode‐based system or radiofrequency identification tags may also increase reliability of patient identification in the mass casualty setup.
Positron emission tomography of stage IV mucosa‐associated lymphoid tissue lymphoma confined to the four major salivary glands
Authors: Mac Manus MP , Ryan G , Lau E , Wirth A , Hicks RJ
Published: January 2007

In a patient with stage IVA marginal zone lymphoma, 18F‐fluorodeoxyglucose‐positron emission tomography indicated that the disease was confined to the four major salivary glands. The positron emission tomography findings encouraged the use of radiotherapy with curative intent in this case. After 30 Gy of external beam radiotherapy to the parotid and submandibular glands, the patient entered a complete remission and remains free from progression more than 4 years later.
Radiology teaching: Essentials of a quality teaching programme
Authors: Subramaniam RM , Gibson RN
Published: January 2007

Medical student teaching is an important component of radiology education. Despite the practice of radiology undergoing significant changes during the last two or three decades, the importance of radiology has not translated fully into medical school curricula in Australia and New Zealand. This article reviews the essential components of a quality medical student teaching programme.
Epithelioid sarcoma of the median nerve mimicking a peripheral nerve sheath tumour
Authors: Harish S , Saifuddin A , Fajinmi M
Published: January 2007

We describe a case of epithelioid sarcoma of the median nerve in a 57‐year‐old woman presenting with symptoms and signs of carpal tunnel syndrome for 2 years. The clinical examination was suggestive of a wrist ganglion compressing the median nerve. Magnetic resonance imaging (MRI) showed a 5 cm × 3 cm mass involving the median nerve in the carpal tunnel and appearances mimicked a benign peripheral nerve sheath tumour. This report illustrates a rare tumour presenting in a rare location and emphasizes the atypical clinical and MRI features that should alert the radiologist to the possibility of a rare sarcoma mimicking a benign peripheral nerve sheath tumour.
Hyaline‐vascular type Castleman’s disease of the pararenal retroperitoneum: Multidetector CT findings
Authors: Demir MK , Aker FV
Published: January 2007

We describe the case of a 40‐year‐old woman who presented with a pararenal hyaline‐vascular type Castleman’s disease that had an arterial supply from the renal artery and a draining vein as showed by multidetector CT. Identification of the renal artery relationship to the feeding vessel of the mass is critical to prevent potential surgical complications.
Robinow syndrome: Report of two cases and review of the literature
Authors: Al Kaissi A , Bieganski T , Baranska D , Chehida FB , Gharbi H , Ghachem MB , Hendaoui L , Safi H , Kozlowski K
Published: January 2007

We report two patients with Robinow syndrome, review the published literature and stress the importance and limitations of radiographic examination in the diagnosis of this disorder, which shows extreme clinical and radiographic variability. The radiographic differential diagnosis of Robinow syndrome is discussed.
Stage I seminoma in a 15‐year‐old boy
Authors: Geake J , Potter AE , Borg MF , Lipsett J , Koukourou A
Published: January 2007

Seminomas are very rare tumours in children and adolescents. We describe a case of seminoma in a 15‐year‐old boy who was managed with orchidectomy but no adjuvant therapy. He remains relapse‐free 8 years after surgery as determined by clinical, radiological and serological surveillance. This study emphasizes the uncertainty over the need for adjuvant treatment in the management of seminoma in the adolescent patient, in particular in prepubescent children.
Twelve weeks’ treatment with diazoxide without insulin supplementation in Type 2 diabetes is feasible but does not improve insulin secretion
Authors: Radtke M. , Kollind M. , Qvigstad E. , Grill V.
Published: January 2007

Aims  Treatment with K‐ATP channel openers, such as diazoxide, can have beneficial effects on insulin secretion in both Type 1 and Type 2 diabetes. However, the precise conditions for obtaining beneficial effects without untoward events have not been determined. We tested the hypothesis that intermittent administration of diazoxide at bedtime for 12 weeks could produce beneficial effects in the absence of side‐effects in Type 2 diabetic patients who were not taking insulin.

Methods  After an 8‐week run‐in period, during which treatment with repaglinide and metformin was optimized, we randomized 26 patients to either diazoxide, 100 mg at bedtime, or placebo.

Results  Side‐effects were absent or minimal. HbA1c did not change. However day‐time glucose concentrations by home glucose monitoring were ∼1.5 mmol/l higher with diazoxide vs. placebo. Stimulation tests (C‐peptide‐glucagon and breakfast) did not indicate improved pancreatic B‐cell function, except by posthoc analysis, in a subgroup of younger age.

Conclusion  Compared with previous results with diazoxide together with bedtime insulin, the present results are less favourable and indicate that concomitant insulin treatment is needed during intervention with K‐ATP channel openers.
S‐nitrosoglutathione‐containing hydrogel accelerates rat cutaneous wound repair
Authors: Amadeu TP , Seabra AB , De Oliveira MG , Costa AMA
Published: January 2007

Background  Nitric oxide (NO) plays a key role in wound repair and S‐nitrosothiols like S‐nitrosoglutathione (GSNO) are well known NO donors.

Methods  Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 µm)‐containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re‐epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin‐fixed, paraffin embedded for histological analysis.

Results  Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P < 0.05 for both). The re‐epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P < 0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty‐one days after wounding, thin red‐yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO‐treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups.

Conclusion  Topical application of GSNO‐containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re‐epithelialization and affects granulation tissue organization.
Effects of polyphenols on skin damage due to ultraviolet A rays: an experimental study on rats
Authors: Sevın A , Öztaş P , Senen D , Han Ü , Karaman Ç , Tarimci N , Kartal M , Erdoǧan B
Published: January 2007

Background  Ultraviolet (UV) radiation causes many acute and chronic conditions such as oedema of the skin, sunburn, immunosuppression, photo‐ageing and skin cancer. The use of antioxidants has become of paramount importance in prevention of the damage caused by ultraviolet radiation. Epigallocatechin‐3‐gallate (EGCG), one of the main components of green tea, has been reported to have anti‐inflammatory, antioxidant and anticarcinogenic properties.

Aim  The aim of this experimental study was to investigate to what extent EGCG prevented acute skin damage caused by UVA.

Material and method  The sample contained 2% EGCG, which was prepared in hydrophilic ointment (USP XXIV) as the vehicle. Twenty‐four 12‐week‐old Wistar albino rats are included in the study and divided into four groups, each containing six rats. Group I was formed to be the control group, which was not applied any topical medication or exposed to UV radiation. Group II was formed to observe acute effects of UVA on the skin, Group III was formed to observe effectiveness of topical EGCG on the skin applied 30 min after exposure to UVA, and Group IV was formed to observe topical EGCG applied 30 min before exposure to UVA. All groups were examined for sunburn cells, leucocyte infiltration, dermo‐epidermal activity, collagen changes and elastic fibre pathologies on 24 and 72 h. Statistical analysis was performed using spss 11.5, and chi‐squared test was used for the evaluation of parameters.

Results  Group IV showed a statistically significant decrease in sunburn cells and dermo‐epidermal activation compared with Group II. Group II showed significant increase in all parameters compared with Group I, showing the effects of UV exposure alone, and no difference was detected in Group II and III.

Conclusion  These results show a protective effect of EGCG when applied topically before UVA exposure. No benefit was detected when EGCG was applied after UV exposure.
Increasing rates of quinolone‐resistant Neisseria gonorrhoeae in Paris, France
Authors: Farhi D , Gerhardt P , Falissard B , Poupet H , Poyart C , Dupin N
Published: January 2007

Background  Quinolone‐resistant Neisseria gonorrhoeae (QRNG) rates are increasing worldwide.

Objectives  (i) To assess the rate of QRNG among patients referred to a venereology clinic in Paris between 2000 and 2004; and (ii) to assess associated epidemiological factors.

Methods  Retrospective study of consecutive cases over 2000–2004. Indications and techniques of swabbing and culture were constant over 2000–2004. Susceptibility of N. gonorrhoeae was tested to six antibiotics: ciprofloxacin, amoxicillin, cefotaxime, tetracycline, erythromycin, and spectinomycin. Epidemiological data and anatomical site of N. gonorrhoeae infection were collected.

Results  Annual numbers of cases decreased (P < 10−4) from 2000 (n = 41) to 2002 (n = 12), then increased (P < 10−4) in 2004 (n = 60). Anorectal gonorrhoea was more frequent in 2003–2004 (22.0%, n = 18/82) than in 2000–2002 (3.9%, n = 3/76). QRNG rates increased from the period 2000–2002 (1.3%) to 2003 (22.7%, P < 0.01), and 2004 (30.2%, P < 0.005). All QRNG strains had a minimal inhibitory concentration of ciprofloxacin > 1.0 mg/L, thus fitting the international definition of quinolone resistance. There were no significant changes in rates of N. gonorrhoeae resistance to the five other antibiotics. QRNG tended to be more frequent among men who have sex with men (MSM; 16.7% vs. 7.1%), HIV‐infected patient (20.5% vs. 11.9%), and patients having more than five partners during the last year (24.4% vs. 17.1%), but statistical significance was not reached in multivariate analyses.

Conclusion  We recommend (i) avoiding fluoroquinolones as first‐line treatment for N. gonorrhoeae infections in Paris; (ii) that first‐line treatment relies on third‐generation cephalosporins or spectinomycin; and (iii) reinforcing targeted screening and prevention of gonorrhoea, especially among HIV‐positive patients and MSM.
Female sexual dysfunction in Lower Egypt
Authors: Elnashar AM , EL‐Dien Ibrahim M , EL‐Desoky MM , Ali OM , El‐Sayd Mohamed Hassan M
Published: January 2007

Objective  The aim of this study was to assess the prevalence and associated factors of female sexual dysfunction (FSD) in Lower Egypt.

Design  A cross‐sectional clinic‐/hospital‐based survey.

Setting  Five district medical centres in Dakahlia Governorate: Shirbin, Bilquas, Samblawen, Dekrinis and Mansoura City.

Population  One thousand married women aged between 16 and 49 years.

Methods  Data were collected by personal interview in a questionnaire format in addition to physical examination (when allowed).

Main outcome measures  FSD and associated risk factors.

Results  The response rate was 93.6%. 68.9% of women had one or more sexual problems; however, 23% of the women with sexual problems were not distressed by these issues. 31.5% of women suffered from dyspareunia. 49.6% of the women had decreased sexual desire, 36% had difficult arousal and 16.9% had anorgasmia (primary and secondary). Marital disharmony, ‘hate’ and unfavourable socio‐economic circumstances were the most common aggravating factors (28.1%) for sexual dysfunction among the participants, followed by pregnancy‐related events (15.7%). Most women (84.5%) received no help for their sexual problems. 90.3% of the women were circumcised. Only 7.1% (46 of 645) of women with sexual problems had received treatment, with no real improvement reported in 58.7% (27 of the 46 women).

Conclusions  FSD is a highly prevalent problem within the scope of this study. Low reporting rates and very low treatment rates were identified in the sample from Lower Egypt.
Psychological and biological markers of stress and bacterial vaginosis in pregnant women
Authors: Harville EW , Savitz DA , Dole N , Thorp JM , Herring AH
Published: January 2007

Objectives  To determine whether stress is associated with risk of bacterial vaginosis (BV) in pregnant women.

Design  Prospective cohort study.

Setting  The prenatal care clinics at the University of North Carolina. The residents’ clinic sees mostly government‐insured and uninsured women, and the physicians’ clinic sees mostly those with private health insurance.

Population  A total of 897 women gave samples for BV analysis. Study participants were 22% African‐American, 68% white; 24% unmarried and 44% nulliparous. More than half had completed college.

Methods  Women completed two questionnaires and two interviews reporting stress and psychological aspects of their lives. Measurement scales included the Sarason life events questionnaire, the Cohen perceived stress scale, Spielberger state–trait anxiety, the John Henryism coping style and the Medical Outcomes Study social support inventory. Two stress hormones, corticotrophin‐releasing hormone and cortisol, were also measured.

Main outcome measures  BV at 15–19 and 24–29 weeks of gestation was diagnosed by Gram’s stain.

Results  Women in the highest quartile of stress measures, particularly state anxiety (OR = 2.0, 95% CI 1.2–3.3), perceived stress (OR = 2.4, 95% CI 1.5–3.9) and total life events (OR = 2.0, 95% CI 1.3–3.2), had the highest risk of BV. Adjustment for confounders, especially age, race, and income, reduced these associations (state anxiety: OR = 1.3, 95% CI 0.7–2.4; perceived stress: OR = 1.4, 95% CI 0.8–2.5; total life events: OR = 1.3, 95% CI 0.7–2.4). No clear pattern of association was seen between stress hormones and BV.

Conclusions  Few associations between stress and BV were seen after adjustment for confounders.
Nonviolent Action from a Social‐psychological Perspective*
Authors: Hare A. Paul
Published: January 2007

A social‐psychological perspective, used in the analysis of three cases of nonviolent direct action, combines the “exchange theory” of Homans and the two and three dimensional approaches for the analysis of interpersonal behavior suggested by Leary and Bales. The three dimensions are: dominance‐submission, positive‐negative, and goal, oriented‐deviant. Once the behavior of a nonviolent actor has been identified in this three dimensional space, the expected behavior of his opponent can be predicted.
Searching Data for Predictive Variables: A Set‐Theoretical Approach*
Authors: Muir Donal E.
Published: January 2007

A common task of the scientific investigator is to search out factors which will predict the presence or absence of some variable attribute in which he is interested. Procedures for such searches are spelled out in Mill's famous canons of discovery. A set‐theoretical analysis of these, however, discloses unnecessary inconsistency and difficulty, and leads to a single canon which extracts maximal information concerning causal factors from arbitrary sequences of cases, while reminding the researcher of the limitations of finite samples of both subjects and measures.
The Sociological Profession and Revolution*
Authors: Fasola‐Bologna Alfredo
Published: January 2007

Is present Western sociology helping prepare revolution? Conservative and liberal sociologies clearly help keep the social system as it is without questioning it at its roots. But also the current radical research is not as radical as it may seem, since it implicitly accepts the socio‐political ignorance of the masses and does not question the neo‐capitalistic principle of separation between theory and praxis. The final objective of a revolutionary sociology should be to make all people become their own revolutionary sociologists.
Sociology as a Skin Trade
Authors: O'Neill John
Published: January 2007

The purpose of the essay is to connect the practice of sociology with the sensitizing concept of a skin trade in order to relate it to the commonsense needs of the body‐politic. The critical observations on professional sociology are not the focus of the essay any more than the concerns of modern youth which are adopted as a context for its argument. The essay intentionally avoids documentation in the conventional sense for the sake of the improvisation contained in the image of the skin trade. It is the first step in a series of studies in the skin trade in which I hope to treat race, for example, as a skin disease and to develop the social and political aspects of various other body events.
Book Review
Authors: Rein Martin
Published: January 2007

Book reviewed in this article:

Daniel P. Moynihan, Maximum Feasible Misunderstanding: Community Action in the War on Poverty. N.Y.: Free Press, 1969. xxi, 218 pp. $5.95.