bluuebunny/crossref_metadata_2025 huggingface dataset:
Current progress and limitations of spider silk for biomedical applications
Authors: Widhe Mona , Johansson Jan , Hedhammar My , Rising Anna
Published: September 2011

Spider silk is a fascinating material combining remarkable mechanical properties with low density and biodegradability. Because of these properties and historical descriptions of medical applications, spider silk has been proposed to be the ideal biomaterial. However, overcoming the obstacles to produce spider silk in sufficient quantities and in a manner that meets regulatory demands has proven to be a difficult task. Also, there are relatively few studies of spider silk in biomedical applications available, and the methods and materials used vary a lot. Herein we summarize cell culture‐ and in vivo implantation studies of natural and synthetic spider silk, and also review the current status and future challenges in the quest for a large scale production of spider silk for medical applications. © 2011 Wiley Periodicals, Inc. Biopolymers 97: 468–478, 2012.
In vivo flow cytometry: A horizon of opportunities
Authors: Tuchin Valery V. , Tárnok Attila , Zharov Vladimir P.
Published: September 2011

Flow cytometry (FCM) has been a fundamental tool of biological discovery for many years. Invasive extraction of cells from a living organism, however, may lead to changes in cell properties and prevents studying cells in their native environment. These problems can be overcome by use of in vivo FCM, which provides detection and imaging of circulating normal and abnormal cells directly in blood or lymph flow. The goal of this review is to provide a brief history, features, and challenges of this new generation of FCM methods and instruments. Spectrum of possibilities of in vivo FCM in biological science (e.g., cell metabolism, immune function, or apoptosis) and medical fields (e.g., cancer, infection, and cardiovascular disorder) including integrated photoacoustic‐photothermal theranostics of circulating abnormal cells are discussed with focus on recent advances of this new platform. © 2011 International Society for Advancement of Cytometry
Predictive Models for Freshwater Biological Assessment: Statistical Approaches, Biological Elements and the Iberian Peninsula Experience: A Review
Authors: Feio Maria Joao , Poquet José Manuel
Published: September 2011

In the last three decades, predictive models have been developed and applied worldwide for freshwater bioassessment. They consist of statistical tools that follow the concept of the Reference Condition Approach. Composed of several sequential steps, these assessment tools assess the deviation of given site assemblages from the expected biological condition in the absence of human disturbance. The most common approaches (RIVPACS/AUSRIVAS and BEAST) are based on a posteriori classifications that use the biological composition of a community to classify reference sites in groups, and afterwards to establish which environmental features best discriminate the biological groups obtained. Here, we review the predictive modeling procedures used in freshwaters bioassessment (RIVPACS/AUSRIVAS, BEAST, ANNA, Artificial Neural Networks, Bayesian Belief Networks and others) as well as the biological elements to which they have been applied.

We also review the Spanish and Portuguese experiences in the development and application of predictive models, with particular attention to regional environmental conditions, the different modeling approaches, and the available implementation tools. Moreover, and considering the natural continuity within the Iberian Peninsula (which include several transnational rivers), we discuss the possibilities of the development of common predictive models across the region, considering all factors that may influence their performance, such as the target scale used to develop the models (regional or peninsular); common reference criteria; sampling and sorting procedures; the taxonomic resolution used in the models; the temporal variability (mainly in the Iberian Mediterranean region); and the biological elements to consider. We concluded that there are good technical conditions for the implementations of a common predictive approach throughout the Iberian Peninsula, which should allow a global biological assessment of streams with different biological elements and seasons that could be used by water managers in the context of the Water Framework Directive. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Ovarian development of a river catfish Hemibagrus nemurus (Valenciennes, 1840) in captivity
Authors: Adebiyi Fatimat Adenike , Siraj Siti Shapor , Harmin Sharr Azni , Christianus Annie
Published: September 2011

Hemibagrus nemurus is a riverine catfish with high economic and nutritive values. Investigations on ovarian development of this fish were carried out to determine the mode of ovarian development and describe the oocyte developmental stages. Histological studies were done on ovaries using light microscopy and scanning electron microscopy. Fish were sampled monthly for a period of six months (August 2009 to January 2010). The mean oocyte diameter (OD) ranged from 871 ± 161.41 µm to 1,167 ± 26.77 µm and the highest OD was in November. Oocyte size–frequency distribution showed a polymodal distribution. The mean gonadosomatic index (GSI) ranged from 1.14 ± 0.87% to 7.06 ± 1.40% and highest GSI was in November. The ovaries exhibited three phases of oocyte growth, which were primary growth, secondary growth and maturation phases. Based on histological criteria, the oocyte developmental stages were divided into seven stages as chromatin nucleolar, early perinucleolar, late perinucleolar, cortical alveolar, vitellogenesis, mature oocyte and germinal vesicle migration stages. All the seven stages of oocyte development were observed in the ovaries. Oogonia were always present throughout the developmental stages. The ovaries had more than two stages of oocyte development. This is the first report on the mode of ovarian development of H. nemurus. These findings indicated that H. nemurus has asynchronous mode of ovarian development and is capable of spawning several times in a year under favourable conditions. J. Exp. Zool. 315:536–543, 2011. © 2011 Wiley Periodicals, Inc.
Resistance to empiric antimicrobial treatment predicts outcome in severe sepsis associated with gram‐negative bacteremia
Authors: Micek Scott T. , Welch Emily C. , Khan Junaid , Pervez Mubashir , Doherty Joshua A. , Reichley Richard M. , Hoppe‐Bauer Joan , Dunne W. Michael , Kollef Marin H.
Published: September 2011

BACKGROUND:

Gram‐negative bacteria are an important cause of severe sepsis. Recent studies have demonstrated reduced susceptibility of Gram‐negative bacteria to currently available antimicrobial agents.

METHODS:

We performed a retrospective cohort study of patients with severe sepsis who were bacteremic with Pseudomonas aeruginosa, Acinetobacter species, or Enterobacteriaceae from 2002 to 2007. Patients were identified by the hospital informatics database and pertinent clinical data (demographics, baseline severity of illness, source of bacteremia, and therapy) were retrieved from electronic medical records. All patients were treated with antimicrobial agents within 12 hours of having blood cultures drawn that were subsequently positive for bacterial pathogens. The primary outcome was hospital mortality.

RESULTS:

A total of 535 patients with severe sepsis and Gram‐negative bacteremia were identified. Hospital mortality was 43.6%, and 82 (15.3%) patients were treated with an antimicrobial regimen to which the causative pathogen was resistant. Patients infected with a resistant pathogen had significantly greater risk of hospital mortality (63.4% vs 40.0%; P < 0.001). In a multivariate analysis, infection with a pathogen that was resistant to the empiric antibiotic regimen, increasing APACHE II scores, infection with Pseudomonas aeruginosa, healthcare‐associated hospital‐onset infection, mechanical ventilation, and use of vasopressors were independently associated with hospital mortality.

CONCLUSIONS:

In severe sepsis attributed to Gram‐negative bacteremia, initial treatment with an antibiotic regimen to which the causative pathogen is resistant was associated with increased hospital mortality. This finding suggests that rapid determination of bacterial susceptibility could influence treatment choices in patients with severe sepsis potentially improving their clinical outcomes. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine
Provider expectations and experiences of comanagement
Authors: Hinami Keiki , Whelan Chad T. , Konetzka R. Tamara , Meltzer David O.
Published: September 2011

BACKGROUND:

Hospitalist comanagement of complex surgical and medical specialty patients is increasingly common, but it is unclear how provider expectations and experiences under the collaborative practice model differ from those of traditional consultations.

METHODS:

We analyzed survey data examining expectations and experiences on a medical hepatology comanagement service. Participating hospitalists, nonphysician providers (NPPs), hepatologists, and fellows completed a Baseline Survey that addressed preferences for decision‐making under comanagement. Repeated Surveys, administered to each unique team of comanagers, addressed their experiences with decision‐making on their rotations on the service between April and October 2008.

RESULTS:

All 43 providers completed the Baseline Survey. Among these, 32 providers who rotated on the service completed 79% (177/223) of Repeated Surveys. The majority of respondents indicated understanding their role. More providers of every professional role indicated their preference for hospitalists to participate in every management decision and for hepatologists not to participate in every management decision. Most indicated that they both preferred and experienced the direction of management issues by a single physician leader. Almost all indicated at baseline that comanagement tends to improve patient care (hospitalists 94%, hepatologists 83%, NPPs 100%, fellows 100%), although fewer NPPs (40%) and fellows (50%) felt comanagement actually improved care following their rotations.

CONCLUSIONS:

Preferences and experiences about provider roles are not uniform under comanagement, and conflicting preferences exist around decision‐making processes. Providers generally agreed that comanaging hospitalists should participate broadly in management decisions. Journal of Hospital Medicine 2011. © 2011 Society of Hospital Medicine
Posttraumatic stress hyperarousal symptoms mediate the relationship between childhood exposure to violence and subsequent alcohol misuse in Mi'kmaq youth
Authors: Zahradnik Marc , Stewart Sherry H. , Sherry Simon B. , Stevens Doreen , Wekerle Christine
Published: September 2011

This study was part of a school‐based collaborative research project with a Canadian Mi'kmaq community that examined the potential role of posttraumatic stress (PTS) symptom clusters in mediating the relationship between childhood exposure to violence (EV) and alcohol misuse in a sample of Mi'kmaq adolescents (N = 166). The study employed a cross‐sectional design and used several well‐validated self‐report questionnaires. Path analytic results showed that when each PTS symptom cluster was independently investigated for mediating effects while controlling for depressive symptoms, age, and gender, only the PTS hyperarousal symptom cluster fully mediated the EV–alcohol misuse relationship. Results are discussed within the context of previous theory and research on the topic of PTS as a mediator between EV and alcohol misuse.
Stakeholder management and program planning in German public theaters
Authors: Boerner Sabine , Jobst Johanna
Published: September 2011

Taking the example of a German public professional theater, this study is the first to analyze how stakeholder interests are managed in the process of program planning. We address the following questions: (1) What are the goals and interests of the most influential stakeholders? (2) How are these goals and interests reflected by theater management when deciding the season's program? (3) Which strategies does theater management apply to balance conflicting stakeholder goals and interests? Results of our qualitative study identify five decisions to be made with regard to program planning: selection of the season's theme, plays, stage directors, cast, and chronological order of productions. Four strategies of balancing conflicting stakeholder goals and interests are identified: setting priorities, combining stakeholder interests, focusing on neutral goals, and developing audiences.
Miscibility and morphological properties of quaternized polysulfone blends with polystyrene and poly(4‐vinylpyridine)
Authors: Albu Raluca Marinica , Avram Ecaterina , Stoica Iuliana , Ioanid Emil Ghiocel , Ioan Silvia
Published: September 2011

Quaternized polysulfones were synthesized by the quaternization reaction of chloromethylated polysulfone with different tertiary amines −N,N‐dimethylethylamine (DMEA) andN,N‐dimethyloctylamine (DMOA), respectively. New blends from these quaternized polysulfones (PSF‐DMEA or PSF‐DMOA) with polystyrene (PS) or poly(4‐vinylpyridine) (P4VP) were prepared by the solution casting method. Pure quaternized polysulfones, inN,N‐dimethylformamide (DMF)/methanol (MeOH) and DMF/water solvent/nonsolvent mixtures, and their blends with PS and P4VP, as well, were investigated by shear viscometry and viscoelasticity, atomic force microscopy, differential scanning calorimetry, and surface properties. The results obtained revealed that the blends have good miscibility. Surface morphology is characterized by roughness and nodules formations, depending on the alkyl radical lengths, composition of the polymer mixtures, including specific electron‐donor or electron‐acceptor characteristics of polymers. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers
Electron spin resonance study of single‐walled carbon nanotubes
Authors: Monge Aida Abiad , Ferrer‐Anglada Núria , Lloveras Vega , Vidal‐Gancedo José , Roth Siegmar
Published: September 2011

Studies of electron spin resonance (ESR) are reported on several types of single‐walled carbon nanotubes (SWCNTs) synthesized by different methods. We work both with the obtained samples, which contained randomly distributed semiconducting and metallic SWCNTs, and with selected 99% semiconducting or metallic SWCNTs. Our aim is to use ESR spectroscopy in order to assess the quality of carbon nanotubes. We analyze the temperature dependence of ESR spectra in the range 4–300 K and report the temperature dependence of the linewidth, the intensity and the asymmetry factor (I+/I−) of the ESR lines. The ESR response from the arc discharge SWCNTs produced using non‐magnetic Pt/Rh catalyst and from the selected semiconducting tubes exhibits an asymmetric line with an intensity that remains almost constant with decreasing temperature, showing a constant linewidth of about 2.9 mT. For selected bucky paper (BP) metallic or semiconducting carbon nanotubes, we also study the ESR signal according to the BP parallel or perpendicular orientation to the magnetic field. The g‐factor and the asymmetry factor show a clear anisotropy.
A NEW EXAMPLE OF A MINIMAL NONFINITELY BASED SEMIGROUP
Authors: ZHANG WEN TING , LUO YAN FENG
Published: September 2011

Only three of the 15 973 distinct six-element semigroups are presently known to be nonfinitely based. This paper introduces a fourth example.
A randomised crossover study investigating the effects of galacto-oligosaccharides on the faecal microbiota in men and women over 50 years of age
Authors: Walton Gemma E. , van den Heuvel Ellen G. H. M. , Kosters Marit H. W. , Rastall Robert A. , Tuohy Kieran M. , Gibson Glenn R.
Published: September 2011

Faecal microbial changes associated with ageing include reduced bifidobacteria numbers. These changes coincide with an increased risk of disease development. Prebiotics have been observed to increase bifidobacteria numbers within humans. The present study aimed to determine if prebiotic galacto-oligosaccharides (GOS) could benefit a population of men and women of 50 years and above, through modulation of faecal microbiota, fermentation characteristics and faecal water genotoxicity. A total of thirty-seven volunteers completed this randomised, double-blind, placebo-controlled crossover trial. The treatments – juice containing 4 g GOS and placebo – were consumed twice daily for 3 weeks, preceded by 3-week washout periods. To study the effect of GOS on different large bowel regions, three-stage continuous culture systems were conducted in parallel using faecal inocula from three volunteers. Faecal samples were microbially enumerated by quantitative PCR.In vivo, following GOS intervention, bifidobacteria were significantly more compared to post-placebo (P = 0·02). Accordingly, GOS supplementation had a bifidogenic effect in allin vitrosystem vessels. Furthermore, in vessel 1 (similar to the proximal colon), GOS fermentation led to more lactobacilli and increased butyrate. No changes in faecal water genotoxicity were observed. To conclude, GOS supplementation significantly increased bifidobacteria numbersin vivoandin vitro. Increased butyrate production and elevated bifidobacteria numbers may constitute beneficial modulation of the gut microbiota in a maturing population.
Review about acceleration of plasma by nonlinear forces from picoseond laser pulses and block generated fusion flame in uncompressed fuel
Authors: Hora H. , Miley G.H. , Flippo K. , Lalousis P. , Castillo R. , Yang X. , Malekynia B. , Ghoranneviss M.
Published: September 2011

In addition to the matured “laser inertial fusion energy” with spherical compression and thermal ignition of deuterium-tritium (DT), a very new alternative for the fast ignition scheme may have now been opened by using side-on block ignition aiming beyond the DT-fusion with igniting the neutron-free reaction of proton-boron-11 (p-11B). Measurements with laser pulses of terawatt power and ps duration led to the discovery of an anomaly of interaction, if the prepulses are cut off by a factor 108(contrast ratio) to avoid relativistic self focusing in agreement with preceding computations. Applying this to petawatt (PW) pulses for Bobin-Chu conditions of side-on ignition of solid fusion fuel results after several improvements in energy gains of 10,000. This is in contrast to the impossible laser-ignition of p-11B by the usual spherical compression and thermal ignition. The side-on ignition is less than ten times only more difficult than for DT ignition. This is essentially based on the instant and direct conversion the optical laser energy by the nonlinear force into extremely high plasma acceleration. Genuine two-fluid hydrodynamic computations for DT are presented showing details how ps laser pulses generate a fusion flame in solid state density with an increase of the density in the thin flame region. Densities four times higher are produced automatically confirming a Rankine-Hugoniot shock wave process with an increasing thickness of the shock up to the nanosecond range and a shock velocity of 1500 km/s which is characteristic for these reactions.
Scattering of carbon ions in the material of the protective membrane of a fast ignition, indirect compression target without cone
Authors: Shmatov Mikhail L.
Published: September 2011

It is shown that scattering of the laser-accelerated carbon ions in the material of the protective membrane of a fast ignition, indirect compression target without cone can result in a significant increase in the hot spot radius and will complicate significantly or even prevent the effective shaping of the bombarded region of the compressed fuel.
Inhibition of polyglutamine-mediated proteotoxicity by Astragalus membranaceus polysaccharide through the DAF-16/FOXO transcription factor in Caenorhabditis elegans
Authors: Zhang Hanrui , Pan Ni , Xiong Siqin , Zou Shenglong , Li Haifeng , Xiao Lingyun , Cao Zhijian , Tunnacliffe Alan , Huang Zebo
Published: September 2011

Late-onset neurodegenerative diseases are characterized by progressive accumulation of aggregation-prone proteins and global disruption of the proteostasis network, e.g. abnormal polyQ (polyglutamine) aggregation in Huntington's disease. Astragalus membranaceus polysaccharide (astragalan) has recently been shown to modulate aging and proteotoxic stress pathways. Using Caenorhabditis elegans models, we now show that astragalan not only reduces polyQ aggregation, but also alleviates the associated neurotoxicity. We also reveal that astragalan can extend the adult lifespan of wild-type and polyQ nematodes, indicating a connection of its anti-aging benefit with the toxicity-suppressing effect. Further examination demonstrates that astragalan can extend the lifespan of daf-2 and age-1, but not daf-16, mutant nematodes of the insulin-like aging and stress pathway, suggesting a lifespan-regulation signalling independent of DAF (abnormal dauer formation)-2/IGF-1R (insulin-like growth factor 1 receptor), but dependent on the DAF-16/FOXO (forkhead box O) transcription factor, a pivotal integrator of divergent signalling pathways related to both lifespan regulation and stress resistance. We also show that a subset of DAF-16 downstream genes are regulated by astragalan, including the DAF-16 transcriptional target gene scl-20, which is itself constitutively up-regulated in transgenic polyQ nematodes. These findings, together with our previous work on LEA (late embryogenesis abundant) proteins and trehalose, provide a revealing insight into the potential of stress and lifespan regulators in the prevention of proteotoxic disorders.
Resonances of surface and volume plasmons in atomic clusters
Authors: Gildenburg V. B. , Kostin V. A. , Pavlichenko I. A.
Published: September 2011

The resonance phenomena caused by the excitation of the surface and volume plasmons in the metal and ionized atomic clusters are studied in the framework of hydrodynamic and kinetic approaches with the inclusion of radiative, collisional, and kinetic (collisionless) damping mechanisms. The resonances of dipole moment at the frequencies of the volume plasmons are found to be strongly damped by the collision-induced losses, while the field amplitude at the central region of the cluster may exhibit large increase at the resonance of both kind of plasmons.
Hybrid coupled-cluster and perturbation method for extended systems of one-dimensional periodicity
Authors: Ohnishi Yu-ya , Hirata So
Published: September 2011

A hybrid of the coupled-cluster singles and doubles (CCSD) and second-order Møller–Plesset perturbation (MP2) methods [M. Nooijen, J. Chem. Phys. 111, 10815 (1999)10.1063/1.480445; A. D. Bochevarov and C. D. Sherrill, ibid. 122, 234110 (2005); A. D. Bochevarov et al., ibid. 125, 054109 (2006)] is formulated and implemented for one-dimensional periodic extended systems, in which the excitation (T) amplitudes of active bands are determined iteratively by CCSD, while the T amplitudes of mixed active/inactive bands are held fixed at the first-order Møller–Plesset perturbation values. The occupied and virtual bands near the Fermi level, which can cause instability in MP2 when they are (quasi-)degenerate, are selected as active bands to be treated by CCSD, which can, in principle, resist such instability. Two contraction schemes of the T amplitudes (Contractions A and B) are considered. Contraction A is the one proposed for molecules and used also for extended systems because it is efficient for CCSD, but not necessarily so for the hybrid CCSD/MP2. Contraction B is introduced to be more optimally efficient for the hybrid CCSD/MP2 by maximizing the number of intermediate quantities made of the inactive T amplitudes and molecular integrals, which do not vary during CCSD iterations and are computed only once, stored, and reused. In an application to trans-polyacetylene, a smooth transition of the results of the hybrid CCSD/MP2 is observed toward those of CCSD and MP2 by increasing and decreasing, respectively, the number of active bands. With the smallest active space, the hybrid CCSD/MP2 with Contractions A and B achieves a speedup by a factor of 360 and 520, respectively, relative to CCSD. When all of the occupied bands and about half of the virtual bands are active, the hybrid CCSD/MP2 can recover 98% of the CCSD correlation energy or half of the difference between CCSD and MP2 at less than a tenth of the usual CCSD cost.
Rotational analysis and deperturbation of the A 2Π → X 2Σ+ and B′ 2Σ+ → X 2Σ+ emission spectra of MgH
Authors: Shayesteh Alireza , Bernath Peter F.
Published: September 2011

Deperturbation analysis of the A 2Π → X 2Σ+ and B′ 2Σ+ → X 2Σ+ emission spectra of 24MgH is reported. Spectroscopic data for the v = 0 to 3 levels of the A 2Π state and the v = 0 to 4 levels of the B′ 2Σ+ state were fitted together using a single Hamiltonian matrix that includes 2Π and 2Σ+ matrix elements, as well as off-diagonal elements coupling several vibrational levels of the two states. A Dunham-type fit was performed and the resulting Yl,0 and Yl,1 coefficients were used to generate Rydberg–Klein–Rees (RKR) potential curves for the A 2Π and the B′ 2Σ+ states. Vibrational overlap integrals were computed from the RKR potentials, and the off-diagonal matrix elements coupling the electronic wavefunctions (a+ and b) were determined. Zero point dissociation energies (D0) of the A 2Π and B′ 2Σ+ states of 24MgH were determined to be 12 957.5 ± 0.5 and 10 133.6 ± 0.5 cm−1, respectively. Using the Y0,1 coefficients, the equilibrium internuclear distances (re) of the A 2Π and B′ 2Σ+ states were determined to be 1.67827(1) Å and 2.59404(4) Å, respectively.
Evidence of superatom electronic shells in ligand-stabilized aluminum clusters
Authors: Andre Clayborne P. , Lopez-Acevedo Olga , Whetten Robert L. , Grönbeck Henrik , Häkkinen Hannu
Published: September 2011

Ligand-stabilized aluminum clusters are investigated by density functional theory calculations. Analysis of Kohn-Sham molecular orbitals and projected density of states uncovers an electronic shell structure that adheres to the superatom complex model for ligand-stabilized aluminum clusters. In this current study, we explain how the superatom complex electron-counting rule is influenced by the electron-withdrawing ligand and a dopant atom in the metallic core. The results may guide the prediction of new stable ligand-stabilized (superatom) complexes, regardless of core and electron-withdrawing ligand composition.
Paleozoic origin of insect large dsDNA viruses
Authors: Thézé Julien , Bézier Annie , Periquet Georges , Drezen Jean-Michel , Herniou Elisabeth A.
Published: September 2011

To understand how extant viruses interact with their hosts, we need a historical framework of their evolutionary association. Akin to retrovirus or hepadnavirus viral fossils present in eukaryotic genomes, bracoviruses are integrated in braconid wasp genomes and are transmitted by Mendelian inheritance. However, unlike viral genomic fossils, they have retained functional machineries homologous to those of large dsDNA viruses pathogenic to arthropods. Using a phylogenomic approach, we resolved the relationships between bracoviruses and their closest free relatives: baculoviruses and nudiviruses. The phylogeny showed that bracoviruses are nested within the nudivirus clade. Bracoviruses establish a bridge between the virus and animal worlds. Their inclusion in a virus phylogeny allowed us to relate free viruses to fossils. The ages of the wasps were used to calibrate the virus phylogeny. Bayesian analyses revealed that insect dsDNA viruses first evolved at ∼310 Mya in the Paleozoic Era during the Carboniferous Period with the first insects. Furthermore the virus diversification time frame during the Mesozoic Era appears linked to the diversification of insect orders; baculoviruses that infect larvae evolved at the same period as holometabolous insects. These results imply ancient coevolution by resource tracking between several insect dsDNA virus families and their hosts, dating back to 310 Mya.
Experimental and theoretical study on the energy-dependent surface evolution and microstructure changes in copper nanostructured composites
Authors: Foong Y M , Koh A T T , Chua D H C
Published: September 2011

Many studies have shown that the properties of single carbon system films are governed by the energy of the impinging carbon ions but the role of metal in addition to carbon ions as in diamond-like carbon (DLC) nanocomposites is not yet available. In this study, DLC films doped with different fractions of copper (5 and 15 at%) were fabricated using the pulsed laser deposition technique at varied laser energies, and the energy dependence of surface evolution and changes in microstructures due to the presence of metal were experimentally characterized. By considering the substitution of carbon by copper atoms in the target, the interaction between laser/target and the role of copper ions as envisaged in Saha's equation, the energy of the ions was calculated and good agreement with experimental results was reported. In the presence of copper that increased the ion energy, the excess heat released upon the impingement of ions during the formation of composite films can (1) enhance surface diffusion and promote the formation of nanoislands, and (2) graphitize the diamond bonding in the carbon matrix as seen experimentally. Simulations showed that the metal ions were implanted into the subsurface of the carbon matrix, thus reducing the surface roughness with increasing laser energy as well as increasing copper content. Although the formation of nanoclusters reduced the sp3 bonding of the films, mechanical testing showed that the adhesion strength of the films were improved with the presence of nanoclusters and SiC formed during the deposition.
MYH9 and APOL1 are both associated with sickle cell disease nephropathy
Authors: Ashley‐Koch Allison E. , Okocha Emmanuel C. , Garrett Melanie E. , Soldano Karen , De Castro Laura M. , Jonassaint Jude C. , Orringer Eugene P. , Eckman James R. , Telen Marilyn J.
Published: September 2011

Renal failure occurs in 5–18% of sickle cell disease (SCD) patients and is associated with early mortality. At‐risk SCD patients cannot be identified prior to the appearance of proteinuria and the pathobiology is not well understood. The myosin, heavy chain 9, non‐muscle (MYH9) and apolipoprotein L1 (APOL1) genes have been associated with risk for focal segmental glomerulosclerosis and end‐stage renal disease in African Americans. We genotyped 26 single nucleotide polymorphisms (SNPs) in MYH9 and 2 SNPs in APOL1 (representing the G1 and G2 tags) in 521 unrelated adult (18–83 years) SCD patients screened for proteinuria. Using logistic regression, SNPs were evaluated for association with proteinuria. Seven SNPs in MYH9 and one in APOL1 remained significantly associated with proteinuria after multiple testing correction (P < 0·0025). An MYH9 risk haplotype (P = 0·001) and the APOL1 G1/G2 recessive model (P < 0·0001) were strongly associated with proteinuria, even when accounting for the other. Glomerular filtration rate was negatively correlated with proteinuria (P < 0·0001), and was significantly predicted by an interaction between MYH9 and APOL1 in age‐adjusted analyses. Our data provide insight into the pathobiology of renal dysfunction in SCD, suggesting that MYH9 and APOL1 are both associated with risk.
Mitochondrial decay in ageing: ‘Qi‐invigorating’ schisandrin B as a hormetic agent for mitigating age‐related diseases
Authors: Leong Pou K , Chen Na , Ko Kam M
Published: September 2011

1. The mitochondrial free radical theory of ageing (MFRTA) proposes a primary role for mitochondrial reactive oxygen species (ROS) in the ageing process. The reductive hot spot hypothesis of mammalian ageing serves as a supplement to the MFRTA by explaining how the relatively few cells that have lost oxidative phosphorylation capacity due to mitochondrial DNA mutations can be toxic to the rest of the body and result in the development of age‐related diseases.

2. Schisandrin B (SchB), which can induce both a glutathione anti‐oxidant and a heat shock response via redox‐sensitive signalling pathways, is a hormetic agent potentially useful for increasing the resistance of tissues to oxidative damage. The enhanced cellular/mitochondrial anti‐oxidant status and heat shock response afforded by SchB can preserve the structural and functional integrity of mitochondria, suggesting a potential role for SchB in ameliorating age‐related diseases.

3. Future studies will focus on investigating whether SchB can produce the hormetic response in humans.
Single cysteine substitution in Bacillus thuringiensis Cry7Ba1 improves the crystal solubility and produces toxicity to Plutella xylostella larvae
Authors: Peng Donghai , Wang Fenshan , Li Nisha , Zhang Zhenyu , Song Rong , Zhu Zimin , Ruan Lifang , Sun Ming
Published: September 2011

Many Bacillus thuringiensis isolates have no demonstrated toxicity against insects. In this study, a novel holotype crystal protein gene cry7Ba1 was isolated from a ‘non‐insecticidal’B. thuringiensis strain YBT‐978. The Cry7Ba1 protein showed high toxicity against Plutella xylostella larvae after the crystals were dissolved at pH 12.5, suggesting that the ‘non‐insecticidal’ properties of this protein were due to insolubility in the normal insect midgut pH environment. After the C‐terminal half of Cry7Ba1 was replaced by that of Cry1Ac or Cry1C proteins, the recombinant protein inclusions could be dissolved at pH 9.5, and exhibited high toxicity against P. xylostella larvae. This result proved the insolubility of Cry7Ba1 crystal was determined by the structure of its C‐terminal half. Further, six mutations were constructed by substituting cysteine residues with serine. Solubility studies showed that the crystals from mutants C697S, C834S and C854S could be dissolved at lower pH (10.5, 9.5 and 11.5 respectively). Bioassays showed that crystals from mutant C834S were toxic to P. xylostella larvae. Our discoveries suggest that a single cysteine residue located in the C‐terminal half of the protein determines the solubility and toxicity of some nontoxic crystal proteins. This study provides a strategy to isolate novel insecticidal crystal protein genes from ‘non‐insecticidal’B. thuringiensis strains.
Open radical prostatectomy in the elderly: a case for concern?
Authors: Trinh Quoc‐Dien , Schmitges Jan , Sun Maxine , Shariat Shahrokh F. , Sukumar Shyam , Tian Zhe , Bianchi Marco , Sammon Jesse , Perrotte Paul , Rogers Craig G. , Graefen Markus , Peabody James O. , Menon Mani , Karakiewicz Pierre I.
Published: September 2011

Study Type – Therapy (case series)

Level of Evidence 4

What's known on the subject? and What does the study add?

Adverse outcomes after radical prostatectomy are more often recorded in the elderly.

In the USA, elderly patients undergoing radical prostatectomy are treated at institutions where suboptimal outcomes are recorded.

OBJECTIVE

To assess the rate of adverse outcomes after open radical prostatectomy (ORP) in the elderly and to examine the effect of annual hospital caseload (AHC) and academic institutional status on adverse outcomes in these of patients.

PATIENTS AND METHODS

Within the Health Care Utilization Project Nationwide Inpatient Sample, we focused on ORPs performed between 1998 and 2007. Subsequently, we restricted to patients aged ≥75 years.

In both datasets, we examined transfusion rates, intra‐operative and postoperative complication rates, and in‐hospital mortality rates.

Stratification was performed according to AHC tertiles and academic status.

Multivariable logistic regression analyses were fitted.

RESULTS

Of 115 554 ORP patients, 2109 (1.8%) were aged ≥75 years.

In multivariable analyses performed in the entire cohort, elderly age increased homologous blood transfusion rates (P < 0.001), intra‐operative (P= 0.001) and postoperative (P < 0.001) complication rates, and the mortality rate (P= 0.007).

Most elderly were treated at low or intermediate AHC (68.5%) and non‐academic centres (56.2%).

Within the elderly cohort, intra‐operative (2.9%) and postoperative (22.2%) complications tended to be highest at low AHC institutions compared to institutions of intermediate (2.7% and 17.4%) and high AHC (1.7% and 14.5%). Similarly, intra‐operative (2.7% vs 2.1%) and postoperative complications (19.1% vs 13.9%) tended to be higher at non‐academic than academic centres.

In multivariable analyses performed in the elderly subgroup, low AHC predicted higher intra‐operative complications and higher homologous transfusions, whereas non‐academic status predicted higher postoperative complications.

CONCLUSIONS

Adverse outcomes are more often recorded in the elderly.

Most elderly are treated at institutions where suboptimal outcomes are recorded.
Osteoprotegerin gene polymorphism in diabetic Charcot neuroarthropathy
Authors: Korzon‐Burakowska A. , Jakóbkiewicz‐Banecka J. , Fiedosiuk A. , Petrova N. , Koblik T. , Gabig‐Cimińska M. , Edmonds M. , Małecki M. T. , Węgrzyn G.
Published: September 2011

Diabet. Med. 29, 771–775 (2012)

Aims  Recently, an association between two polymorphisms (1181G>C and 245T>G) of the osteoprotegerin (OPG) gene and diabetic Charcot neuroarthropathy was suggested on the basis of studies of a limited number of samples derived from subjects from one geographical region (Italy). The aim of this study was to assess the presence of various osteoprotegerin gene polymorphisms in patients with diabetes and Charcot neuroarthropathy compared with subjects with diabetic neuropathy but no Charcot foot and healthy controls from another geographical region (Poland).

Methods  DNA was isolated from 54 patients with Charcot neuroarthropathy, 35 subjects with diabetic neuropathy but no Charcot foot, and 95 healthy controls to evaluate OPG gene polymorphisms and their possible contribution to the development of Charcot neuroarthropathy.

Results  Statistically significant differences between the group of subjects with neuropathy but no Charcot neuroarthropathy and the control group were found for 1217C>T, 950T>C and 245T>G polymorphisms, between the group of patients with Charcot neuroarthropathy and the control group for 1181G>C and 950T>C polymorphisms, and between the group of subjects with neuropathy but no Charcot neuroarthropathy and the group of patients with Charcot neuroarthropathy for 1217C>T and 245T>G polymorphisms.

Conclusion  We suggest that genetic factors, particularly OPG gene polymorphisms, may play a role in the development of diabetic Charcot neuroarthropathy.
Equity and debt issuance by firms violating GAAP
Authors: Bardos Katsiaryna Salavei , Zaiats Nataliya
Published: September 2011

We examine security issuance in restated periods by firms that misreport financial statements and find that only a small per cent of such firms issues securities in the restated period. Investors are misled by mistakes made by firms issuing equity more so than other restating firms at the initial announcement of misreported earnings, but are not misled by mistakes made by debt‐issuing firms. Equity‐issuing firms that manage earnings to beat analyst expectations experience abnormally high returns in the restated period prior to security issuance. Firms that restated more reports and have higher pre‐mistake returns are more likely to issue equity. High leverage, firm size and number of restated periods are positively associated with the likelihood of debt issuance by restating firms.
Employment Protection Versus Flexicurity: On Technology Adoption in Unionised Firms*
Authors: Lommerud Kjell Erik , Straume Odd Rune
Published: September 2011

We analyse how different labour‐market institutions – employment protection versus ‘flexicurity’– affect technology adoption in unionised firms. We consider trade unions’ incentives to oppose or endorse labour‐saving technology and firms’ incentives to invest in such technology. Increased flexicurity – interpreted as less employment protection and a higher reservation wage for workers – unambiguously increases firms’ incentives for technology adoption. If unions have some direct influence on technology, a higher reservation wage also makes unions more willing to accept technological change. Less employment protection has the opposite effect, as this increases the downside (job losses) of labour‐saving technology.
What women want. Women’s preferences for the management of low‐grade abnormal cervical screening tests: a systematic review
Authors: Frederiksen ME , Lynge E , Rebolj M
Published: September 2011

Please cite this paper as: Frederiksen M, Lynge E, Rebolj M. What women want. Women’s preferences for the management of low‐grade abnormal cervical screening tests: a systematic review. BJOG 2012;119:7–19.

Background  If human papillomavirus (HPV) testing will replace cytology in primary cervical screening, the frequency of low‐grade abnormal screening tests will double. Several available alternatives for the follow‐up of low‐grade abnormal screening tests have similar outcomes. In this situation, women’s preferences have been proposed as a guide for management decisions.

Objectives  To determine women’s preferences for the follow‐up of low‐grade cervical screening abnormalities.

Search strategy  Using Medical Subject Headings (MeSH) terms, PubMed was searched for articles published up to December 2010. The reference lists of the retrieved studies were consulted.

Selection criteria  Studies asking women to state a preference between active follow‐up and observation for the management of low‐grade abnormalities on screening cytology or HPV tests.

Data collection and analysis  Information on study design, participants and outcomes was retrieved using a prespecified form. Studies were sorted by design.

Main results  Thirteen studies were included in the review. In all five studies that surveyed women with abnormal tests before any management had started, two‐thirds preferred active follow‐up, predominantly as immediate colposcopy, to observation, predominantly as repeated Pap smears. In all but two studies testing other situations, women more often expressed a preference for active follow‐up than for observation; however, women appeared to be somewhat more willing to accept observation if reassured of the low risk of cervical cancer.

Conclusions  Even for low‐grade abnormal cervical tests, women tend to prefer active management strategies. It may be a challenge to meet their expectations of optimal follow‐up when HPV testing is used in primary screening.
Effects of palmitoylation of Cys415 in helix 8 of the CB1 cannabinoid receptor on membrane localization and signalling
Authors: Oddi Sergio , Dainese Enrico , Sandiford Simone , Fezza Filomena , Lanuti Mirko , Chiurchiù Valerio , Totaro Antonio , Catanzaro Giuseppina , Barcaroli Daniela , De Laurenzi Vincenzo , Centonze Diego , Mukhopadhyay Somnath , Selent Jana , Howlett Allyn C , Maccarrone Mauro
Published: September 2011

BACKGROUND AND PURPOSE The CB1 cannabinoid receptor is regulated by its association with membrane microdomains such as lipid rafts. Here, we investigated the role of palmitoylation of the CB1 receptor by analysing the functional consequences of site‐specific mutation of Cys415, the likely site of palmitoylation at the end of helix 8, in terms of membrane association, raft targeting and signalling.

EXPERIMENTAL APPROACH The palmitoylation state of CB1 receptors in rat forebrain was assessed by depalmitoylation/repalmitoylation experiments. Cys415 was replaced with alanine by site‐directed mutagenesis. Green fluorescence protein chimeras of both wild‐type and mutant receptors were transiently expressed and functionally characterized in SH‐SY5Y cells and HEK‐293 cells by means of confocal microscopy, cytofluorimetry and competitive binding assays. Confocal fluorescence recovery after photobleaching was used to assess receptor membrane dynamics, whereas signalling activity was assessed by [35S]GTPγS, cAMP and co‐immunoprecipitation assays.

KEY RESULTS Endogenous CB1 receptors in rat brain were palmitoylated. Mutation of Cys415 prevented the palmitoylation of the receptor in transfected cells and reduced its recruitment to plasma membrane and lipid rafts; it also increased protein diffusional mobility. The same mutation markedly reduced the functional coupling of CB1 receptors with G‐proteins and adenylyl cyclase, whereas depalmitoylation abolished receptor association with a specific subset of G‐proteins.

CONCLUSIONS AND IMPLICATIONS CB1 receptors were post‐translationally modified by palmitoylation. Mutation of Cys415 provides a receptor that is functionally impaired in terms of membrane targeting and signalling.

LINKED ARTICLES This article is part of a themed section on Cannabinoids in Biology and Medicine. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue‐8. To view Part I of Cannabinoids in Biology and Medicine visit http://dx.doi.org/10.1111/bph.2011.163.issue‐7
Human obesity and endothelium‐dependent responsiveness
Authors: Campia Umberto , Tesauro Manfredi , Cardillo Carmine
Published: September 2011

Obesity is an ongoing worldwide epidemic. Besides being a medical condition in itself, obesity dramatically increases the risk of development of metabolic and cardiovascular disease. This risk appears to stem from multiple abnormalities in adipose tissue function leading to a chronic inflammatory state and to dysregulation of the endocrine and paracrine actions of adipocyte‐derived factors. These, in turn, disrupt vascular homeostasis by causing an imbalance between the NO pathway and the endothelin 1 system, with impaired insulin‐stimulated endothelium‐dependent vasodilation. Importantly, emerging evidence suggests that the vascular dysfunction of obesity is not just limited to the endothelium, but also involves the other layers of the vessel wall. In particular, obesity‐related changes in medial smooth muscle cells seem to disrupt the physiological facilitatory action of insulin on the responsiveness to vasodilator stimuli, whereas the adventitia and perivascular fat appear to be a source of pro‐inflammatory and vasoactive factors that may contribute to endothelial and smooth muscle cell dysfunction, and to the pathogenesis of vascular disease. While obesity‐induced vascular dysfunction appears to be reversible, at least in part, with weight control strategies, these have not proved sufficient to prevent the metabolic and cardiovascular complication of obesity on a large scale. While a number of currently available drugs have shown potentially beneficial vascular effects in patients with obesity and the metabolic syndrome, elucidation of the pathophysiological mechanisms underlying vascular damage in obese patients is necessary to identify additional pharmacologic targets to prevent the cardiovascular complications of obesity, and their human and economic costs.

LINKED ARTICLES This article is part of a themed section on Fat and Vascular Responsiveness. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2012.165.issue‐3