bluuebunny/crossref_metadata_2025 huggingface dataset:
Theoretical insights into the built-in electric field and band offsets of BN/C heterostructured zigzag nanotubes
Authors: Fan Yingcai , Hou Keyu , Wang Zhenhai , He Tao , Zhang Xuejuan , Zhang Hongyu , Dong Jianmin , Liu Xiangdong , Zhao Mingwen
Published: February 2011

We perform first-principles calculations to investigate the band offsets of (9,0) and (10,0) BN/C heterostructured nanotubes with different interfaces. We show that the built-in electric field induced by charge redistribution modulates the band offsets of these nanotubes in different ways. Remarkably enhanced field-emission properties of the heterostructures are also predicted.
Tailoring the magnetism of GaMnAs films by ion irradiation
Authors: Lin Li  , S D Yao  , Shengqiang Zhou  , D Bürger  , O Roshchupkina  , S Akhmadaliev  , A W Rushforth  , R P Campion  , J Fassbender  , M Helm  , B L Gallagher  , C Timm  , H Schmidt
Published: February 2011

In this paper the affiliation of S D Yao is incorrect. The correct affiliation should be:

1State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871, People's Republic of China

Also, the address for the second affiliation has changed to:

2Institut für Ionenstrahlphysik und Materialforschung, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Bautzner Landstraße 128, 01328 Dresden, Germany
On certain homotopy properties of some spaces of linear and piecewise linear homeomorphisms. II
Authors: Ho Chung Wu
Published: February 2011

In his study of the smoothings of p. l. manifolds, R. Thom considered the homotopy groups of a certain space

L
n

{L_n}

of p.l. homeomorphisms on an

n
n

-simplex. N. H. Kuiper showed in 1965 that the higher homotopy groups of

L
n

{L_n}

were in general nontrivial. The main result in this paper is that

π
0

(

L
2

)
=

π
1

(

L
2

)
=
0

{\pi _0}({L_2}) = {\pi _1}({L_2}) = 0

. The proof of this result is based on a theorem of S. S. Cairns in 1944 on the deformation of rectilinear complexes in

R
2

{R^2}

and a theorem established in Part I of this paper.
Traveling wave solutions of a gradient system: solutions with a prescribed winding number. I
Authors: Terman David
Published: February 2011

Consideration is given to a system of equations of the form

u
t

=

u

x
x

+
∇
F
(
u
)

{u_t} = {u_{xx}} + \nabla F(u)

,

u
∈

R

2

u \in {{\mathbf {R}}^2}

. In a previous paper [6], conditions of

F
F

were given which guarantee that the system possesses infinitely many traveling wave solutions. The solutions are now characterized by how many times they wind around in phase space. A winding number for solutions is defined. It is demonstrated that for each positive integer

K
K

, there exists at least two traveling wave solutions, each with winding number

K
K

or

K
+
1

K + 1

.
Flower: extracting information from pyrosequencing data
Authors: Malde Ketil
Published: February 2011

Summary: The SFF file format produced by Roche's 454 sequencing technology is a compact, binary format that contains the flow values that are used for base and quality calling of the reads. Applications, e.g. in metagenomics, often depend on accurate sequence information, and access to flow values is important to estimate the probability of errors. Unfortunately, the programs supplied by Roche for accessing this information are not publicly available. Flower is a program that can extract the information contained in SFF files, and convert it to various textual output formats.

Availability: Flower is freely available under the General Public License.

Contact:  ketil.malde@imr.no
Condensing biomedical journal texts through paragraph ranking
Authors: Chiang Jung-Hsien , Liu Heng-Hui , Huang Yi-Ting
Published: February 2011

Motivation: The growing availability of full-text scientific articles raises the important issue of how to most efficiently digest full-text content. Although article titles and abstracts provide accurate and concise information on an article's contents, their brevity inevitably entails the loss of detail. Full-text articles provide those details, but require more time to read. The primary goal of this study is to combine the advantages of concise abstracts and detail-rich full-texts to ease the burden of reading.

Results: We retrieved abstract-related paragraphs from full-text articles through shared keywords between the abstract and paragraphs from the main text. Significant paragraphs were then recommended by applying a proposed paragraph ranking approach. Finally, the user was provided with a condensed text consisting of these significant paragraphs, allowing the user to save time from perusing the whole article. We compared the performance of the proposed approach with a keyword counting approach and a PageRank-like approach. Evaluation was conducted in two aspects: the importance of each retrieved paragraph and the information coverage of a set of retrieved paragraphs. In both evaluations, the proposed approach outperformed the other approaches.

Contact:  jchiang@mail.ncku.edu.tw
Distribution of Epidural Saline Upon Injection and the Epidural Volume Effect in Pregnant Women
Authors: Higuchi Hideyuki , Takagi Shunichi , Onuki Eriko , Fujita Nobuko , Ozaki Makoto
Published: February 2011

Background

How injected epidural solution is distributed and affects the epidural volume in pregnant women are unclear.

Methods

Lumbar epidural catheters were placed using the loss-of-resistance technique with saline in eight full-term (39 weeks' gestation) parturients for labor and eight volunteer nonpregnant women. Lumbosacral cerebrospinal fluid volume was measured on thoracic and lumbosacral axial magnetic resonance images. Another image series was obtained after injecting 10 ml saline into the epidural space through the catheter to compare the saline distribution (dural sac coating and exit from foramina) and cerebrospinal fluid volume before and after epidural injection. Dural sac coating was based on observation of epidural saline in the anterior epidural space after injection in axial magnetic resonance images at the pedicle levels from T12 to L5. Saline leakage from the foramina was determined by the same method at six disc levels from T11-T12 to L4-L5.

Results

Significantly fewer images of pregnant women than nonpregnant women showed saline surrounding the dural sac (0 [0-0] vs. 3 [1-4], median [interquartile range]; P < 0.01) and saline leakage from the foramina (0 [0-1] vs. 6 [4-6]; P < 0.01). The mean reduction in cerebrospinal fluid volume was significantly greater in pregnant (8.4 ± 1.4 ml; mean ± SD) than in nonpregnant women (4.6 ± 1.1 ml; P < 0.001).

Conclusion

Limited dural sac coating and decreased leakage from the foramina of saline injected into the epidural space may account for the facilitation of longitudinal spread of epidural analgesia in pregnant women. The epidural volume effect is greater in pregnant than in nonpregnant women.
Prognostic Value of Troponin and Creatine Kinase Muscle and Brain Isoenzyme Measurement after Noncardiac Surgery
Authors: Levy Michael , Heels-Ansdell Diane , Hiralal Rajesh , Bhandari Mohit , Guyatt Gordon , Yusuf Salim , Cook Deborah , Villar Juan Carlos , McQueen Matthew , McFalls Edward , Filipovic Miodrag , Schünemann Holger , Sear John , Foex Pierre , Lim Wendy , Landesberg Giora , Godet Gilles , Poldermans Don , Bursi Francesca , Kertai Miklos D. , Bhatnagar Neera , Devereaux P. J.
Published: February 2011

Background

There is uncertainty regarding the prognostic value of troponin and creatine kinase muscle and brain isoenzyme measurements after noncardiac surgery.

Methods

The current study undertook a systematic review and meta-analysis. The study used six search strategies and included noncardiac surgery studies that provided data from a multivariable analysis assessing whether a postoperative troponin or creatine kinase muscle and brain isoenzyme measurement was an independent predictor of mortality or a major cardiovascular event. Independent investigators determined study eligibility and abstracted data in duplicate.

Results

Fourteen studies, enrolling 3,318 patients and 459 deaths, demonstrated that an increased troponin measurement after surgery was an independent predictor of mortality (odds ratio [OR] 3.4, 95% confidence interval [CI] 2.2-5.2), but there was substantial heterogeneity (I(2) = 56%). The independent prognostic capabilities of an increased troponin value after surgery in the 10 studies that assessed intermediate-term (≤ 12 months) mortality was an OR = 6.7 (95% CI 4.1-10.9, I(2) = 0%) and in the 4 studies that assessed long-term (more than 12 months) mortality was an OR = 1.8 (95% CI 1.4-2.3, I(2) = 0%; P < 0.001 for test of interaction). Four studies, including 1,165 patients and 202 deaths, demonstrated an independent association between an increased creatine kinase muscle and brain isoenzyme measurement after surgery and mortality (OR 2.5, 95% CI 1.5-4.0, I(2) = 4%).

Conclusions

An increased troponin measurement after surgery is an independent predictor of mortality, particularly within the first year; limited data suggest an increased creatine kinase muscle and brain isoenzyme measurement also predicts subsequent mortality. Monitoring troponin measurements after noncardiac surgery may allow physicians to better risk stratify and manage their patients.
Impact of Metabolic Control on Bone Quality in Phenylketonuria and Mild Hyperphenylalaninemia
Authors: Porta Francesco , Mussa Alessandro , Zanin Anna , Greggio Nella Augusta , Burlina Alberto , Spada Marco
Published: February 2011

Objectives:

A reduction of bone mineral density of unknown etiology has been reported in phenylketonuria (PKU) by radiological techniques, whereas no data on bone density in mild hyperphenylalaninemia (HPA) are available. We aimed to assess bone condition in PKU and HPA by quantitative ultrasound (QUS), taking into account patients’ clinical and biochemical features.

Patients and Methods:

Phalangeal QUS has been used for bone assessment in 78 patients affected by PKU (n = 42) or mild HPA (n = 36). For each patient, blood phenylalanine concentrations in the 2 years before the study have been recorded and related to bone assessment.

Results:

Overall normal bone quality has been observed in the whole study group (AD‐SoS standard deviation score [SDS] 0.25 ± 1.29; BTT SDS −0.13 ± 1.08). PKU adolescents (age older than 15 years, AD‐SoS SDS −0.54 ± 1.33; BTT SDS −0.85 ± 1.21) and patients with poor compliance with treatment (blood phenylalanine >10 mg/dL, AD‐SoS SDS −0.47 ± 1.39; BTT SDS −0.97 ± 1.14) showed lower BTT SDS with respect to normal population (P = 0.003 and P< 0.001, respectively). Patients with PKU with good compliance with treatment (blood phenylalanine < 10 mg/dL, AD‐SoS SDS 0.65 ± 1.33; BTT SDS 0.15 ± 0.94) and patients with mild HPA (AD‐SoS SDS 0.44 ± 1.06 and BTT SDS 0.19 ± 0.85) showed normal bone mineral density and cortical thickness.

Conclusions:

Good compliance with treatment in PKU during adolescence and adulthood is desirable because diet discontinuation is associated with bone loss. Mild HPA seems not to be complicated by bone damage.
Rga is a regulator of adherence and pilus formation in Streptococcus agalactiae
Authors: Samen Ulrike , Heinz Beate , Boisvert Heike , Eikmanns Bernhard J. , Reinscheid Dieter J. , Borges Frédéric
Published: February 2011

Streptococcus agalactiae is the leading cause of bacterial sepsis and meningitis in neonates and is also the causative agent of several serious infections in immunocompromised adults. S. agalactiae encounters multiple niches during an infection, suggesting that regulatory mechanisms control the expression of specific virulence factors in this bacterium. The present study describes the functional characterization of a gene from S. agalactiae, designated rga, which encodes a protein with significant similarity to members of the RofA-like protein (RALP) family of transcriptional regulators. After deletion of the rga gene in the genome of S. agalactiae, the mutant strain exhibited significantly reduced expression of the genes srr-1 and pilA, which encode a serine-rich repeat surface glycoprotein and a pilus protein, respectively, and moderately increased expression of the fbsA gene, which encodes a fibrinogen-binding protein. Electrophoretic mobility shift assays demonstrated specific DNA binding of purified Rga to the promoter regions of pilA and fbsA, suggesting that Rga directly controls pilA and fbsA. Adherence assays revealed significantly reduced binding of the Δrga mutant to epithelial HEp-2 cells and to immobilized human keratin 4, respectively. In contrast, the adherence of the Δrga mutant to A549 cells and its binding to human fibrinogen was significantly increased. Immunoblot and immunoelectron microscopy revealed that the quantity of pilus structures was significantly reduced in the Δrga mutant compared with the parental strain. The wild-type phenotype could be restored by plasmid-mediated expression of rga, demonstrating that the mutant phenotypes resulted from a loss of Rga function.
The dlt operon confers resistance to cationic antimicrobial peptides in Clostridium difficile
Authors: McBride Shonna M. , Sonenshein Abraham L.
Published: February 2011

Thedltoperon in Gram-positive bacteria encodes proteins that are necessary for the addition ofd-alanine to teichoic acids of the cell wall. The addition ofd-alanine to the cell wall results in a net positive charge on the bacterial cell surface and, as a consequence, can decrease the effectiveness of antimicrobials, such as cationic antimicrobial peptides (CAMPs). Although the roles of thedltgenes have been studied for some Gram-positive organisms, the arrangement of these genes inClostridium difficileand the life cycle of the bacterium in the host are markedly different from those of other pathogens. In the current work, we determined the contribution of the putativeC. difficile dltoperon to CAMP resistance. Our data indicate that thedltoperon is necessary for full resistance ofC. difficileto nisin, gallidermin, polymyxin B and vancomycin. We propose that thed-alanylation of teichoic acids provides protection against antimicrobial peptides that may be essential for growth ofC. difficilein the host.
The pleitropic regulator AdpAch is required for natamycin biosynthesis and morphological differentiation in Streptomyces chattanoogensis
Authors: Du Yi-Ling , Li Shan-Zhen , Zhou Zhan , Chen Shi-Fei , Fan Wei-Ming , Li Yong-Quan
Published: February 2011

The complete natamycin (NTM) biosynthetic gene cluster of Streptomyces chattanoogensis was cloned and confirmed by the disruption of pathway-specific activator genes. Comparative cluster analysis with its counterpart in Streptomyces natalensis revealed different cluster architecture between these two clusters. Compared with the highly conserved coding sequences, sequence variations appear to occur frequently in the intergenic regions. The evolutionary change of nucleotide sequence in the intergenic regions has given rise to different transcriptional organizations in the two clusters and resulted in altered gene regulation. These results provide insight into the evolution of antibiotic biosynthetic gene clusters. In addition, we cloned a pleitropic regulator gene, adpAch
, in S. chattanoogensis. Using the genetic system that we developed for this strain, adpAch
was deleted from the genome of S. chattanoogensis. The ΔadpAch
mutant showed a conditionally sparse aerial mycelium formation phenotype and defects in sporulation; it also lost the ability to produce NTM and a diffusible yellow pigment normally produced by S. chattanoogensis. RT-PCR analysis revealed that transcription of adpAch
was constitutive in YEME liquid medium. By using rapid amplification of 5′ complementary DNA ends, two transcription start sites were identified upstream of the adpAch
coding region. Quantitative transcriptional analysis showed that the expression level of the NTM regulatory gene scnRI decreased 20-fold in the ΔadpAch
mutant strain, while the transcription of the other activator gene scnRII was not significantly affected. Electrophoretic mobility shift assay (EMSA) showed that AdpAch binds to its own promoter but fails to bind to the promoter region of scnRI, indicating that the control of scnRI by AdpAch is exerted in an indirect way. This work not only provides a platform and a new potential target for increasing the titre of NTM by genetic manipulation, but also advances the understanding of the regulation of NTM biosynthesis.
Effect of diet and gut dynamics on the establishment and persistence of Escherichia coli
Authors: O’Brien Claire L. , Gordon David M.
Published: February 2011

Escherichia coli population dynamics and diversity in rats fed diets differing in their crude fibre content were assessed. Female Wistar rats (n = 40) were fed diets containing 1, 4, 18 or 26 % crude fibre. Animals were housed in pairs, and one animal was inoculated with a phylogroup B1 strain of E. coli, the other with a phylogroup B2 strain. Natural strain transmission was allowed to occur between the animals in each cage. As expected, the diets had a significant effect on gut dynamics. Mean gut retention times were shorter in animals fed the 18 and 26 % crude fibre diets compared with animals on the low-fibre diets. The effect of diet on gastrointestinal dynamics in turn affected E. coli population dynamics and clonal composition. Animals fed the low-fibre diets had higher cell densities than animals fed the high-fibre diets. E. coli populations dominated by phylogroup B2 strains exhibited lower cell densities in animals fed the high-fibre diets compared with cell densities in animals fed the low-fibre diets. Overall, E. coli cell densities declined as gut transit times decreased. Results from this experiment support the results garnered from prospective studies examining the distribution of E. coli from hosts with differing diets, gut morphology and dynamics.
The actinobacteria-specific gene wblA controls major developmental transitions in Streptomyces coelicolor A3(2)
Authors: Fowler-Goldsworthy Kay , Gust Bertolt , Mouz Sébastien , Chandra Govind , Findlay Kim C. , Chater Keith F.
Published: February 2011

The Streptomyces coelicolor A3(2) sporulation gene whiB is the paradigm of a family of genes (wbl,
whiB-
like) that are confined to actinobacteria. The chromosome of S. coelicolor contains 11 wbl genes, among which five are conserved in many actinobacteria: whiB itself; whiD, a sporulation gene; wblC, which is required for multi-drug resistance; and wblA and wblE, whose roles had previously been little studied. We succeeded in disrupting wblA and the six non-conserved genes, but could not disrupt wblE. Although mutations in the six non-conserved wbl genes (including some multiple wbl mutants) produced no readily detectable phenotype, mutations in wblA had novel and complex effects. The aerial mycelium of wblA mutants was coloured red, because of the ectopic presence of pigmented antibiotics (actinorhodin and undecylprodigiosin) normally confined to lower parts of wild-type colonies, and consisted almost entirely of non-sporulating, thin, straight filaments, often bundled together in a fibrillar matrix. Rare spore chains were also formed, which exhibited wild-type properties but were genetically still wblA mutants. A wblA mutant achieved higher biomass than the wild-type. Microarray analysis indicated major transcriptional changes in a wblA mutant: using a relatively stringent cut-off, 183 genes were overexpressed, including genes for assimilative primary metabolism and actinorhodin biosynthesis, and 103 were underexpressed, including genes associated with stages of aerial hyphal growth. We suggest that WblA is important in both the slow-down of biomass accumulation and the change from aerial hyphal initial cells to the subapical stem and apical compartments that precede sporulation; and that the mutant aerial mycelium consists of recapitulated defective aerial hyphal initial cells.
Major players on the microbial stage: why archaea are important
Authors: Jarrell Ken F. , Walters Alison D. , Bochiwal Chitvan , Borgia Juliet M. , Dickinson Thomas , Chong James P. J.
Published: February 2011

As microbiology undergoes a renaissance, fuelled in part by developments in new sequencing technologies, the massive diversity and abundance of microbes becomes yet more obvious. The Archaea have traditionally been perceived as a minor group of organisms forced to evolve into environmental niches not occupied by their more ‘successful’ and ‘vigorous’ counterparts, the bacteria. Here we outline some of the evidence gathered by an increasingly large and productive group of scientists that demonstrates not only that the Archaea contribute significantly to global nutrient cycling, but also that they compete successfully in ‘mainstream’ environments. Recent data suggest that the Archaea provide the major routes for ammonia oxidation in the environment. Archaea also have huge economic potential that to date has only been fully realized in the production of thermostable polymerases. Archaea have furnished us with key paradigms for understanding fundamentally conserved processes across all domains of life. In addition, they have provided numerous exemplars of novel biological mechanisms that provide us with a much broader view of the forms that life can take and the way in which micro-organisms can interact with other species. That this information has been garnered in a relatively short period of time, and appears to represent only a small proportion of what the Archaea have to offer, should provide further incentives to microbiologists to investigate the underlying biology of this fascinating domain.
LmrR-mediated gene regulation of multidrug resistance in Lactococcus lactis
Authors: Agustiandari Herfita , Peeters Eveline , de Wit Janny G. , Charlier Daniel , Driessen Arnold J. M.
Published: February 2011

Multidrug resistance (MDR) in Lactococcus lactis is due to the expression of the membrane ATP-binding cassette (ABC) transporter LmrCD. In the absence of drugs, the transcriptional regulator LmrR prevents expression of the lmrCD operon by binding to its operator site. Through an autoregulatory mechanism LmrR also suppresses its own expression. Although the lmrR and lmrCD genes have their own promoters, primer extension analysis showed the presence of a long transcript spanning the entire lmrR–lmrCD cluster, in addition to various shorter transcripts harbouring the lmrCD genes only. ‘In-gel’ Cu-phenanthroline footprinting analysis indicated an extensive interaction between LmrR and the lmrR promoter/operator region. Atomic force microscopy imaging of the binding of LmrR to the control region of lmrR DNA showed severe deformations indicative of DNA wrapping and looping, while LmrR binding to a fragment containing the lmrCD control region induced DNA bending. The results further suggest a drug-dependent regulation mechanism in which the lmrCD genes are co-transcribed with lmrR as a polycistronic messenger. This leads to an LmrR-mediated regulation of lmrCD expression that is exerted from two different locations and by distinct regulatory mechanisms.
Conceptual similarity promotes generalization of higher order fear learning
Authors: Dunsmoor Joseph E. , White Allison J. , LaBar Kevin S.
Published: February 2011

We tested the hypothesis that conceptual similarity promotes generalization of conditioned fear. Using a sensory preconditioning procedure, three groups of subjects learned an association between two cues that were conceptually similar, unrelated, or mismatched. Next, one of the cues was paired with a shock. The other cue was then reintroduced to test for fear generalization, as measured by the skin conductance response. Results showed enhanced fear generalization that correlated with trait anxiety levels in the group that learned an association between conceptually similar stimuli. These findings suggest that conceptual representations of conditional stimuli influence human fear learning processes.
High-pressure experimental study on Rb2S: antifluorite to Ni2In-type phase transitions
Authors: Santamaria-Perez David , Vegas Angel , Muehle Claus , Jansen Martin
Published: February 2011

The high-pressure behaviour of dirubidium sulfide, Rb2S, with antifluorite-type structure under room conditions (space group Fm\bar 3 m) has been studied up to 8 GPa at room temperature using angle-dispersive X-ray powder diffraction in a diamond–anvil cell (DAC). X-ray measurements have allowed us to completely characterize two phase transitions upon compression: (i) to an anticotunnite-type structure (Pnma) at some pressure between 1 bar and 0.7 GPa, and (ii) to a Ni2In-type structure (P63/mmc) at 2.6 GPa. A gradual transition from the Pnma to the P63/mmc structures seems to occur between 2.6 and 4.5 GPa. These results are in excellent agreement with previous theoretical predictions. Strong luminescence is observed above 2.6 GPa (band maximum at 703 nm) when the transition to the Ni2In-type phase starts to occur, the band maximum showing a non-linear blue shift with pressure. The observed sequence of phase transitions in Rb2S is discussed in relation to the high-pressure structural behaviour of isomorphic sulfides and the structures are compared with the cationic arrays of their corresponding oxides (e.g. rubidium sulfate, in which the sulfide has been oxidized).
Structural phase transitions in tetra(isopropylammonium) decachlorotricadmate(II), [(CH3)2CHNH3]4Cd3Cl10, crystal with a two-dimensional cadmium(II) halide network
Authors: Gagor Anna , Waśkowska Alicja , Czapla Zbigniew , Dacko Slawomir
Published: February 2011

Single crystals of tetra(isopropylammonium) decachlorotricadmate(II) as a rare example of a two-dimensional cadmium(II) halide network of [Cd3Cl10]_n^{4 - } have been synthesized and characterized by means of calorimetry and X-ray diffraction. The crystals exhibit polymorphism in a relatively narrow temperature range (three phase transitions at 353, 294 and 259 K). Our main focus was to establish the mechanism of these successive transformations. The crystal structure was solved and refined in the space group Cmce at 375 K (Phase I), Pbca at 320 K (Phase II) and P212121 (Phase III) at 275 K in the same unit-cell metric. The structure is composed of face-sharing polyanionic [Cd3Cl10]4− units which are interconnected at the bridging Cl atom into four-membered rings forming a unique two-dimensional network of [Cd3Cl10]_n^{4 - }. The interstitial voids within the network are large enough to accommodate isopropylammonium cations and permit thermally activated rotations. While in Phase I isopropylammonium tetrahedra rotate almost freely about the C—N bond, the low-temperature phases are the playground of competition between the thermally activated disorder of isopropylammonium cations and stabilizing N—H...Cl hydrogen-bond interactions. The transition from Phase I to II is dominated by a displacive mechanism that leads to significant rearrangement of the polyanionic units. Cation order–disorder phenomena become prominent at lower temperatures.
Predicted and experimental crystal structures of ethyl-tert-butyl ether
Authors: Hammer Sonja M. , Alig Edith , Fink Lothar , Schmidt Martin U.
Published: February 2011

Possible crystal structures of ethyl-tert-butyl ether (ETBE) were predicted by global lattice-energy minimizations using the force-field approach. 33 structures were found within an energy range of 2 kJ mol−1 above the global minimum. Low-temperature crystallization experiments were carried out at 80–160 K. The crystal structure was determined from X-ray powder data. ETBE crystallizes in C2/m, Z = 4, with molecules on mirror planes. The ETBE molecule adopts a trans conformation with a (CH3)3C—O—C—C torsion angle of 180°. The experimental structure corresponds with high accuracy to the predicted structure with energy rank 2, which has an energy of 0.54 kJ mol−1 above the global minimum and is the most dense low-energy structure. In some crystallization experiments a second polymorph was observed, but the quality of the powder data did not allow the determination of the crystal structure. Possibilities and limitations are discussed for solving crystal structures from powder diffraction data by real-space methods and lattice-energy minimizations.
Pseudomonas syringae pv. phaseolicola: from ‘has bean’ to supermodel
Authors: ARNOLD DAWN L. , LOVELL HELEN C. , JACKSON ROBERT W. , MANSFIELD JOHN W.
Published: February 2011

Pseudomonas syringae pv. phaseolicola causes halo blight of the common bean, Phaseolus vulgaris, worldwide and remains difficult to control. Races of the pathogen cause either disease symptoms or a resistant hypersensitive response on a series of differentially reacting bean cultivars. The molecular genetics of the interaction between P. syringae pv. phaseolicola and bean, and the evolution of bacterial virulence, have been investigated in depth and this research has led to important discoveries in the field of plant–microbe interactions. In this review, we discuss several of the areas of study that chart the rise of P. syringae pv. phaseolicola from a common pathogen of bean plants to a molecular plant‐pathogen supermodel bacterium.

Taxonomy: Bacteria; Proteobacteria, gamma subdivision; order Pseudomonadales; family Pseudomonadaceae; genus Pseudomonas; species Pseudomonas syringae; Genomospecies 2; pathogenic variety phaseolicola.

Microbiological properties: Gram‐negative, aerobic, motile, rod‐shaped, 1.5 µm long, 0.7–1.2 µm in diameter, at least one polar flagellum, optimal temperatures for growth of 25–30 °C, oxidase negative, arginine dihydrolase negative, levan positive and elicits the hypersensitive response on tobacco.

Host range: Major bacterial disease of common bean (Phaseolus vulgaris) in temperate regions and above medium altitudes in the tropics. Natural infections have been recorded on several other legume species, including all members of the tribe Phaseoleae with the exception of Desmodium spp. and Pisum sativum.

Disease symptoms: Water‐soaked lesions on leaves, pods, stems or petioles, that quickly develop greenish‐yellow haloes on leaves at temperatures of less than 23 °C. Infected seeds may be symptomless, or have wrinkled or buttery‐yellow patches on the seed coat. Seedling infection is recognized by general chlorosis, stunting and distortion of growth.

Epidemiology: Seed borne and disseminated from exudation by water‐splash and wind occurring during rainfall. Bacteria invade through wounds and natural openings (notably stomata). Weedy and cultivated alternative hosts may also harbour the bacterium.

Disease control: Some measure of control is achieved with copper formulations and streptomycin. Pathogen‐free seed and resistant cultivars are recommended.

Useful websites: Pseudomonas–plant interaction http://www.pseudomonas‐syringae.org/; PseudoDB http://xbase.bham.ac.uk/pseudodb/; Plant Associated and Environmental Microbes Database (PAMDB) http://genome.ppws.vt.edu/cgi‐bin/MLST/home.pl; PseudoMLSA Database http://www.uib.es/microbiologiaBD/Welcome.html
Invertases involved in the development of the parasitic plant Phelipanche ramosa: characterization of the dominant soluble acid isoform, PrSAI1
Authors: DRAIE RIDA , PÉRON THOMAS , POUVREAU JEAN‐BERNARD , VÉRONÉSI CHRISTOPHE , JÉGOU SANDRINE , DELAVAULT PHILIPPE , THOIRON SÉVERINE , SIMIER PHILIPPE
Published: February 2011

Phelipanche ramosa L. parasitizes major crops, acting as a competitive sink for host photoassimilates, especially sucrose. An understanding of the mechanisms of sucrose utilization in parasites is an important step in the development of new control methods. Therefore, in this study, we characterized the invertase gene family in P. ramosa and analysed its involvement in plant development. Invertase‐encoded cDNAs were isolated using degenerate primers corresponding to highly conserved regions of invertases. In addition to enzyme assays, gene expression was analysed using real‐time quantitative reverse transcriptase‐polymerase chain reaction during overall plant development. The dominant isoform was purified and sequenced using electrospray ionization‐liquid chromatography‐tandem mass spectrometry (ESI‐LC‐MS/MS). Five invertase‐encoded cDNAs were thus characterized, including PrSai1 which encodes a soluble acid invertase (SAI). Of the five invertases, PrSai1 transcripts and SAI activity were dominant in growing organs. The most active invertase corresponded to the PrSai1 gene product. The purified PrSAI1 displayed low pI and optimal pH values, specificity for β‐fructofuranosides and inhibition by metallic ions and competitive inhibition by fructose. PrSAI1 is a typical vacuolar SAI that is actively involved in growth following both germination and attachment to host roots. In addition, germinated seeds displayed enhanced cell wall invertase activity (PrCWI) in comparison with preconditioned seeds, suggesting the contribution of this activity in the sink strength of infected roots during the subsequent step of root penetration. Our results show that PrSAI1 and, possibly, PrCWI constitute good targets for the development of new transgenic resistance in host plants using proteinaceous inhibitors or silencing strategies.
Physical association of pattern‐triggered immunity (PTI) and effector‐triggered immunity (ETI) immune receptors in Arabidopsis
Authors: QI YIPING , TSUDA KENICHI , GLAZEBROOK JANE , KATAGIRI FUMIAKI
Published: February 2011

Plants possess two distinct types of immune receptor. The first type, pattern recognition receptors (PRRs), recognizes microbe‐associated molecular patterns (MAMPs) and initiates pattern‐triggered immunity (PTI) on recognition. FLS2 is a PRR, which recognizes a part of bacterial flagellin. The second type, resistance (R) proteins, recognizes pathogen effectors and initiates effector‐triggered immunity (ETI) on recognition. RPM1, RPS2 and RPS5 are R proteins. Here, we provide evidence that FLS2 is physically associated with all three R proteins. Our findings suggest that signalling interactions occur between PTI and ETI at very early stages and/or that FLS2 forms a PTI signalling complex, some components of which are guarded by R proteins.
Influence of attitudes on pharmacists' intention to report serious adverse drug events to the Food and Drug Administration
Authors: Gavaza Paul , Brown Carolyn M. , Lawson Kenneth A. , Rascati Karen L. , Wilson James P. , Steinhardt Mary
Published: February 2011

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Attitude is an important factor impacting pharmacists' reporting of adverse drug events (ADE) to pharmacovigilance centres.

• However, little is known about United States (US) pharmacists' attitudes with respect to ADE reporting. No known study has assessed US pharmacists' attitude to report serious ADEs to the FDA.

WHAT THIS STUDY ADDS

• This study results suggest that pharmacists hold favourable attitudes toward reporting serious ADEs to the FDA and there is an association between pharmacists' attitude and intention to report serious ADEs.

• Pharmacists' beliefs that reporting serious ADEs was time consuming and disrupted the normal workflow impact on reporting intentions.

• Pharmacists' attitudes towards reporting need to be improved in order to enhance patient and drug safety.

AIM To investigate the influence of pharmacists' attitudes on intention to report serious adverse drug events (ADEs) to the Food and Drug Administration (FDA).

METHODS This cross‐sectional study used a mail survey to collect data from hospital and community pharmacists practicing in Texas, United States. Three and 16 items were used to measure intention and attitudes, respectively, using a seven‐point bipolar scale. Pharmacists' demographic and practice characteristics, and past reporting were also measured.

RESULTS The response rate was 26.4% (n= 377/1500 pharmacists). Most pharmacists intended (n= 297, 78.8%) to report serious ADEs that they will encounter to the FDA through MedWatch. Overall, pharmacists held favourable attitudes towards reporting serious ADEs (mean = 24.5, SD = 6.7, possible range 1–49, neutral = 16). Pharmacists intending to report serious ADEs had more favourable attitudes than those who did not (P < 0.001). About 90% of the pharmacists believed that reporting serious ADEs would improve patient safety. However, 72.6% indicated that reporting serious ADEs was time consuming and over half (55.5%) of the respondents believed that reporting serious ADEs disrupted the normal workflow. Non‐intenders held stronger beliefs that ADE reporting would disrupt the normal workflow and was time consuming compared with intenders. Years of experience, number of hours worked and practice setting were associated with pharmacists' attitudes towards reporting (P < 0.05).

CONCLUSIONS Most pharmacists held moderately favourable attitudes and high intentions toward reporting serious ADEs to the FDA. This study's findings contribute to an increased understanding of individual factors that influence pharmacists' attitude and intention towards reporting serious ADEs to the FDA.
Pharmacokinetics of combined treatment with praziquantel and albendazole in neurocysticercosis
Authors: Garcia Hector H. , Lescano Andres G. , Lanchote Vera L. , Pretell E. Javier , Gonzales Isidro , Bustos Javier A. , Takayanagui Osvaldo M. , Bonato Pierina S. , Horton John , Saavedra Herbert , Gonzalez Armando E. , Gilman Robert H. ,   for the Cysticercosis Working Group in Peru
Published: February 2011

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• The antiparasitic drugs albendazole and prazoquantel have been used together before for geohelminths, echinococcosis and cysticercosis, but there is only scarce and discrepant data on the pharmacokinetics of these drugs when given together.

WHAT THIS STUDY ADDS

• This is a randomized, double‐blinded, placebo‐controlled phase II evaluation of the pharmacokinetics of albendazole and praziquantel in 32 patients with neurocysticercosis which demonstrates that combined albendazole + praziquantel is associated with increased albendazole sulfoxide concentrations. These increased concentrations could independently contribute to increased cysticidal efficacy by themselves or in addition to a possible synergistic effect.

AIMS Neurocysticercosis is the most common cause of acquired epilepsy in the world. Antiparasitic treatment of viable brain cysts is of clinical benefit, but current antiparasitic regimes provide incomplete parasiticidal efficacy. Combined use of two antiparasitic drugs may improve clearance of brain parasites. Albendazole (ABZ) has been used together with praziquantel (PZQ) before for geohelminths, echinococcosis and cysticercosis, but their combined use is not yet formally recommended and only scarce, discrepant data exist on their pharmacokinetics when given together. We assessed the pharmacokinetics of their combined use for the treatment of neurocysticercosis.

METHODS A randomized, double‐blind, placebo‐controlled phase II evaluation of the pharmacokinetics of ABZ and PZQ in 32 patients with neurocysticercosis was carried out. Patients received their usual concomitant medications including an antiepileptic drug, dexamethasone, and ranitidine. Randomization was stratified by antiepileptic drug (phenytoin or carbamazepine). Subjects had sequential blood samples taken after the first dose of antiparasitic drugs and again after 9 days of treatment, and were followed for 3 months after dosing.

RESULTS Twenty‐one men and 11 women, aged 16 to 55 (mean age 28) years were included. Albendazole sulfoxide concentrations were increased in the combination group compared with the ABZ alone group, both in patients taking phenytoin and patients taking carbamazepine. PZQ concentrations were also increased by the end of therapy. There were no significant side effects in this study group.

CONCLUSIONS Combined ABZ + PZQ is associated with increased albendazole sulfoxide plasma concentrations. These increased concentrations could independently contribute to increased cysticidal efficacy by themselves or in addition to a possible synergistic effect.
The effect of molasses‐based pre‐fermented juice on the fermentation quality of first‐cut lucerne silage
Authors: Denek N. , Can A. , Avci M. , Aksu T. , Durmaz H.
Published: February 2011

The aim of this study was to evaluate the possible effect of pre‐fermented juice (PFJ) on the fermentation quality and nutritive value of first‐cut lucerne (Medicago sativa L.) silage. The PFJs were prepared using barley (B), wheat (W) and grass herbages (G). Both fresh (PFJ‐B, PFJ‐W and PFJ‐G) and frozen (PFJ‐BF, PFJ‐WF and PFJ‐GF) PFJs were examined. Frozen PFJs were prepared by freezing fresh PFJs at −22°C with 20% glycerol (v/v). Treatments of lucerne silage included (1) control; (2) silage treated with PFJ‐B; (3) silage treated with PFJ‐W; (4) silage treated with PFJ‐G; (5) silage treated with PFJ‐BF; (6) silage treated with PFJ‐WF; and (7) silage treated with PFJ‐GF. All the treatments consisted of five replicate silos, and they were prepared in 1·0‐L glass jar silos. Results showed that silages treated with fresh and frozen PFJs, regardless of plant material, had better fermentation quality than the control silage in terms of lower pH, butyric acid (BA) and ammonia nitrogen (NH3‐N) concentrations, as well as higher lactic acid (LA) concentration (P < 0·05) and in vitro organic matter digestibility (IVOMD), metabolizable energy (ME) content, and gas production values (P < 0·05). Results indicated that PFJ treatments enhanced the nutritive value, fermentation quality and IVOMD, ME content and gas production values of first‐cut lucerne silages.
Influence of post system and remaining coronal tooth tissue on biomechanical behaviour of root filled molar teeth
Authors: Santana F. R. , Castro C. G. , Simamoto‐Júnior P. C. , Soares P. V. , Quagliatto P. S. , Estrela C. , Soares C. J.
Published: February 2011

Santana FR, Castro CG, Simamoto‐Júnior PC, Soares PV, Quagliatto PS, Estrela C, Soares CJ. Influence of post system and remaining coronal tooth tissue on biomechanical behaviour of root filled molar teeth. International Endodontic Journal, 44, 386–394, 2011.

Aim  To investigate ex vivo the influence of post system and amount of remaining coronal tooth tissue on the fracture resistance, fracture mode and strain of root filled molar teeth.

Methodology  Seventy mandibular human molar teeth were divided into seven groups (n = 10), one control (sound teeth) and six experimental groups resulting from the interaction between the two study factors: post system (Pa, post absence; Gfp, glass fibre post; Cmp, cast Ni–Cr alloy post and core) and amount of remaining coronal tooth tissue (Fe, 2 mm of ferrule; NFe, no ferrule). Teeth in the experimental groups were restored with metal crowns. For the strain gauge test, two strain gauges per sample were attached on the buccal and proximal root surfaces, and the samples of each group (n = 5) were submitted to a load of 0–100 N. Fracture resistance (N) was assessed in a mechanical testing device (n = 10). Strain gauge and fracture resistance data were analysed by two‐way anova (3 × 2) followed by the Tukey’s HSD and Duncan’s test (α = 0.05). The failure mode was evaluated using an optical stereomicroscope and classified according to the location of the failure.

Results  The absence of ferrule was associated with lower fracture resistance regardless of the post system. Groups restored with glass fibre post and cast Ni–Cr alloy post and core had similar fracture resistance and higher values than groups without posts, regardless of the remaining coronal tooth tissue. Teeth with no ferrule and cast Ni–Cr alloy post and core resulted in catastrophic fractures and those with no ferrule and glass fibre post or no ferrule and post absence resulted in restorable failures. Buccal strain was higher in sound teeth and lower in teeth without posts. Glass fibre post insertion decreased the buccal strain compared to the teeth with ferrule and absence of post.

Conclusions  Two millimetre of ferrule had a significant influence on cusp strain, fracture resistance and failure mode. The glass fibre post was as effective as the cast Ni–Cr alloy post and core in the restoration of root filled molars regardless of the remaining tooth tissue. Absence of a post decreased the fracture resistance and increased the cusp strain.
Children’s experiences of procedural pain management in conjunction with trauma wound dressings
Authors: Nilsson Stefan , Hallqvist Carina , Sidenvall Birgitta , Enskär Karin
Published: February 2011

nilsson s., hallqvist c., sidenvall b. & enskär k. (2011) Children’s experiences of procedural pain management in conjunction with trauma wound dressings. Journal of Advanced Nursing67(7), 1449–1457.

Aim.  This paper is a report of the experiences of children (5–10 years) of procedural pain when they underwent a trauma wound care session.

Background.  Procedural pain in conjunction with trauma wound care often induces anxiety and distress in children. Children need to alleviate pain and avoid the development of fear in conjunction with examinations and treatments. The nurse could help children to reach this goal by using the comfort theory, which describes holistic nursing in four contexts: physical, psychospiritual, environmental and sociocultural. Few studies have focused on children’s experiences of comforting activities in conjunction with trauma wound dressings.

Methods.  This study was conducted between May 2008 and January 2010. Thirty‐nine participants aged 5–10 were consecutively included in this study. The wound care session was standardized for all the participants, and semi‐structured qualitative interviews with open‐ended questions were conducted with all the children in conjunction with the procedure. All the interviews were transcribed verbatim and analysed with qualitative content analysis.

Findings.  Four themes were identified: clinical competence, distraction, participation and security. The children were helped to reach comforting activities to enhance pain management.

Conclusion.  Children require more than just analgesics in wound care. They also need to experience security and participation in this context. When children feel clinical competence in wound care, they trust the nurse to carry out the wound dressing and instead can focus on the distraction that increases their positive outcomes.
A randomized trial of peer review: the UK National Chronic Obstructive Pulmonary Disease Resources and Outcomes Project: three‐year evaluation
Authors: Roberts Christopher M. , Stone Robert A. , Buckingham Rhona J. , Pursey Nancy A. , Lowe Derek , Potter Jonathan M.
Published: February 2011

Rationale  Peer review has been widely used within the National Health Service to facilitate health quality improvement but evaluation has been limited particularly over the longer‐term. Change within the National Health Service (NHS) can take a prolonged period – 1–2 years – to occur. We report here a 3‐year evaluation of the largest randomized trial of peer review ever conducted in the UK.

Aim  To evaluate whether targeted mutual peer review of respiratory units brings about improvements in services for chronic obstructive pulmonary disease (COPD) over 3 years.

Methods  The peer review intervention was a reciprocal supportive exercise that included clinicians, hospital management, commissioners and patients, which focused on the quality of the provision of four specific evidence‐based aspects of COPD care.

Results  Follow‐up at 36 months demonstrated limited significant quantitative differences in the quality of services offered in the two groups but a strong trend in favour of intervention sites. Qualitative data suggested many benefits of peer review in most but not all intervention units and some control teams. The data identify factors that promote and obstruct change.

Conclusion  The findings demonstrate significant change in service provision over 3 years in both control and intervention sites with great variability in both groups. The combined quantitative and qualitative findings indicate that targeted mutual peer review is associated with improved quality of care, improvements in service delivery and with changes within departments that promote and are precursors to quality improvement. The generic findings of this study have potential implications for the application of peer review throughout the NHS.