bluuebunny/crossref_metadata_2025 huggingface dataset:
Interaction of p53 with Mdm2 and azurin as studied by atomic force spectroscopy
Authors: Funari Gloria , Domenici Fabio , Nardinocchi Lavinia , Puca Rosa , D'Orazi Gabriella , Bizzarri Anna Rita , Cannistraro Salvatore
Published: November 2009

Azurin, a bacterial protein, can be internalized in cancer cells and induce apoptosis. Such anticancer effect is coupled to the formation of a complex with the tumour‐suppressor p53. The mechanism by which azurin stabilizes p53 and the binding sites of their complex are still under investigation. It is also known that the predominant mechanism for p53 down‐regulation implies its association to Mdm2, the main ubiquitin ligase affecting its stability. However, the p53/Mdm2 interaction, occurring at the level of both their N‐terminal domains, has been characterized so far by experiments involving only partial domains of these proteins. The relevance of the p53/Mdm2 complex as a possible target of the anticancer therapies requires a deeper study of this complex as made up of the two entire proteins. Moreover, the apparent antagonist action of azurin against Mdm2, with respect of p53 regulation, might suggest the possibility that azurin binds p53 at the same site of Mdm2, preventing in such a way p53 and Mdm2 from association and thus p53 from degradation. By following the interaction of the two entire proteins by atomic force spectroscopy, we have assessed the formation of a specific complex between p53 and Mdm2. We found for it a binding strength and a dissociation rate constant typical of dynamical protein–protein interactions and we observed that azurin, even if capable to bind p53, does not compete with Mdm2 for the same binding site on p53. The formation of the p53/Mdm2/azurin ternary complex might suggest an alternative anti‐cancer mechanism adopted by azurin. Copyright © 2009 John Wiley & Sons, Ltd.
Element uptake in thalli of the lichen Physcia caesia from sandstone and calcareous substratum
Authors: Hauck Markus , Paul Alexander , Leuschner Christoph
Published: November 2009

Physcia caesia is a foliose, saxicolous lichen commonly found on weakly acidic to alkaline rock and artificial calcareous substrata. Uptake of iron and phosphate, which are known to be significant for governing the calcifuge‐calcicole behavior of lichens (as well as vascular plants), was studied in individuals of P. caesia deriving either from variegated sandstone or concrete. Samples from either substratum originated from walls erected at the same location, i.e., lichens were exposed to the same atmospheric element load and microclimate prior to the experiments. Element uptake was investigated after short‐term incubation in the laboratory involving solutions of FeCl2, FeCl3, and KH2PO4 at pH 3 and 8. Uptake of Fe2+ was significantly higher at either pH in the thalli from concrete than in those from sandstone, whereas Fe3+ uptake was not significantly different between the two groups of lichen thalli, though there was an insignificant trend for higher Fe3+ uptake at pH 8 in the samples from concrete. Phosphate uptake also was more efficient in thalli deriving from concrete than in those from sandstone, even though the initial P content was higher in the samples from sandstone. The results suggest that the ability of P. caesia to adapt Fe and P uptake to the pH‐dependent availabilities of these nutrients is responsible for the potential of the species to grow both on weakly acidic and alkaline substrata.
Growth and photosynthesis of salt‐stressed sunflower (Helianthus annuus) plants as affected by foliar‐applied different potassium salts
Authors: Saeed Akram Muhammad , Ashraf Muhammad , Shahbaz Muhammad , Aisha Akram Nudrat
Published: November 2009

In order to assess the effectiveness of foliar‐applied potassium (K+, 1.25%) using different salts (KCl, KOH, K2CO3, KNO3, KH2PO4, and K2SO4) in ameliorating the inhibitory effect of salt stress on sunflower plants, a greenhouse experiment was conducted. Sodium chloride (150 mM) was applied through the rooting medium to 18 d–old plants and after 1 week of salt treatment; different K+‐containing salts were applied twice in 1‐week interval as a foliar spray. Salt stress adversely affected the growth, yield components, gas exchange, and water relations, and also caused nutrient imbalance in sunflower plants. However, foliar‐applied different sources of potassium improved shoot and root fresh and shoot dry weights, achene yield, 100‐achene weight, photosynthetic rate, transpiration rate, stomatal conductance, water‐use efficiency, relative water content, and leaf and root K+ concentrations of sunflower plants grown under saline conditions. Under nonsaline conditions, improvement in shoot fresh weight, achene yield, 100‐achene weight, photosynthetic and transpiration rates, and root Na+ concentration was observed due to foliar‐applied different K sources. Of the different salts, K2SO4, KH2PO4, KNO3, and K2CO3 were more effective than KCl and KOH in improving growth and some key physiological processes of sunflower plants.
Supercritical biharmonic elliptic problems in domains with small holes
Authors: Guo Yuxia , Wei Juncheng
Published: November 2009

Let D be a bounded and smooth domain in RN, N ≥ 5, P ∈ D. We consider the following biharmonic elliptic problemin Ω = D \Bδ (P),
equation image
with p supercritical, namely . We find a sequence of resonant exponents
equation image
such that if is given, with p ≠ pj for all j, then for all δ > 0 sufficiently small, this problem is solvable (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Price adjustment in German manufacturing: evidence from two merged surveys
Authors: Stahl Harald
Published: November 2009

This paper presents new evidence on the formation of producer prices. The database combines a one‐time survey that was conducted in June 2004 on a sample of 1200 firms in manufacturing and time series information on price adjustment of the same firms. Twenty percent of firms set prices as time‐dependent but neither Taylor nor Calvo‐type price setting describes them aptly. Few firms are forward‐looking. According to the one‐time survey, fixed contracts and coordination failure are the main reason for postponing price adjustment. However, the hazard rates for price changes from the time series information do not support this. Copyright © 2009 John Wiley & Sons, Ltd.
Psychosocial dysfunction in the first year after Guillain–Barré syndrome
Authors: Bernsen Robert A.J.A.M. , de Jager Aeiko E.J. , Kuijer Wietske , van der MechÉ Frans G.A. , Suurmeijer Theo P.B.M.
Published: November 2009

In this investigation we study the impact of Guillain–Barré syndrome (GBS) on psychological distress, depressive symptoms, and health status of patients during the first year after GBS. At 3, 6, and 12 months, patients were given the General Health Questionnaire, the Sickness Impact Profile, and the Center for Epidemiologic Studies Depression Scale. Eighty‐five patients participated. Psychological distress and depressive symptoms were present but improved between 3 and 6 months. At 12 months the psychosocial health status was still impaired. Patients who perceived their physical residua to be moderately to seriously disruptive and patients with muscle ache and cramps had worse scores on all scales. It can be concluded that most of the improvement occurred in the first 6 months. Psychosocial health status, however, was still impaired at 1 year, but depressive symptoms played no role. Treatment of muscle ache and cramps, and the disruptive effect of physical residua should be seriously considered. Muscle Nerve, 2010
Limited diagnostic value of enzyme analysis in patients with mitochondrial tRNA mutations
Authors: Wibrand Flemming , Jeppesen Tina D. , Frederiksen Anja L. , Olsen David B. , Duno Morten , Schwartz Marianne , Vissing John
Published: November 2009

We evaluated the diagnostic value of respiratory chain (RC) enzyme analysis of muscle in adult patients with mitochondrial myopathy (MM). RC enzyme activity was measured in muscle biopsies from 39 patients who carry either the 3243A>G mutation, other tRNA point mutations, or single, large‐scale deletions of mtDNA. Findings were compared with those obtained from asymptomatic relatives with the 3243A>G mutation, myotonic dystrophy patients, and healthy subjects. Plasma lactate concentration, maximal oxygen uptake, and ragged‐red fibers/cytochrome c–negative fibers in muscle were also determined. Only 10% of patients with the 3243A>G point mutation had decreased enzyme activity of one or more RC complexes, whereas this was the case for 83% of patients with other point mutations and 62% of patients with deletions. Abnormal muscle histochemistry was found in 65%, 100%, and 85% of patients, respectively, in these three groups. The results indicate that RC enzyme analysis in muscle is not a sensitive test for MM in adults. In these patients, abnormal muscle histochemistry appears to be a better predictor ofMM. Muscle Nerve, 2010
The 6‐minute walk test as a new outcome measure in Duchenne muscular dystrophy
Authors: McDonald Craig M. , Henricson Erik K. , Han Jay J. , Abresch R. Ted , Nicorici Alina , Elfring Gary L. , Atkinson Leone , Reha Allen , Hirawat Samit , Miller Langdon L.
Published: November 2009

Walking abnormalities are prominent in Duchenne muscular dystrophy (DMD). We modified the 6‐minute walk test (6MWT) for use as an outcome measure in patients with DMD and evaluated its performance in 21 ambulatory boys with DMD and 34 healthy boys, ages 4 to 12 years. Boys with DMD were tested twice, ∼1 week apart; controls were tested once. The groups had similar age, height, and weight. All tests were completed. Boys who fell recovered rapidly from falls without injury. Mean ± SD [range] 6‐minute walk distance (6MWD) was lower in boys with DMD than in controls (366 ± 83 [125–481] m vs. 621 ± 68 [479–754] m; P < 0.0001; unpaired t‐test). Test‐retest correlation for boys with DMD was high (r = 0.91). Stride length (R2 = 0.89; P < 0.0001) was the major determinant of 6MWD for both boys with DMD and controls. A modified 6MWT is feasible and safe, documents disease‐related limitations on ambulation, is reproducible, and offers a new outcome measure for DMD natural history and therapeutic trials. Muscle Nerve, 2010
Ultrasonography in patients with ulnar neuropathy at the elbow: Comparison of cross‐sectional area and swelling ratio with electrophysiological severity
Authors: Bayrak Ayse Oytun , Bayrak Ilkay Koray , Turker Hande , Elmali Muzaffer , Nural Mehmet Selim
Published: November 2009

The aim of this study was to determine the diagnostic value of ultrasonographic measurements in ulnar neuropathy at the elbow (UNE) and to assess the relationship between the measurements and the electrophysiological severity. The largest anteroposterior diameter (LAPD) and cross‐sectional area (CSA) measurements of the ulnar nerve were noted at multiple levels along the arm, and the distal‐to‐proximal ratios were calculated. Almost all of the measurements and swelling ratios between patients and controls showed statistically significant differences. The largest CSA, distal/largest CSA ratio, CSA at the epicondyle, and proximal LAPD had larger areas under the curve than other measurements. The sensitivity and specificity in diagnosing UNE were 95% and 71% for the largest CSA, 83% and 85% for the distal/largest CSA ratio, 83% and 81% for the CSA at the epicondyle, and 93% and 43% for the proximal LAPD, respectively. There was a statistically significant correlation between the electrophysiological severity scale score (ESSS) and the largest CSA, the CSA at the epicondyle and 2 cm proximal to the epicondyle, and the LAPD at the level of the epicondyle (P < 0.05). None of the swelling ratios showed a significant correlation with the ESSS. The largest CSA measurement is the most valuable ultrasonographic measurement both for diagnosis and determining the severity of UNE. Muscle Nerve, 2010
An international urogynecological association (IUGA)/international continence society (ICS) joint report on the terminology for female pelvic floor dysfunction
Authors: Haylen Bernard T. , de Ridder Dirk , Freeman Robert M. , Swift Steven E. , Berghmans Bary , Lee Joseph , Monga Ash , Petri Eckhard , Rizk Diaa E. , Sand Peter K. , Schaer Gabriel N.
Published: November 2009

Introduction

Next to existing terminology of the lower urinary tract, due to its increasing complexity, the terminology for pelvic floor dysfunction in women may be better updated by a female‐specific approach and clinically based consensus report.

Methods

This report combines the input of members of the Standardization and Terminology Committees of two international organizations, the International Urogynecological Association (IUGA), and the International Continence Society (ICS), assisted at intervals by many external referees. Appropriate core clinical categories and a subclassification were developed to give an alphanumeric coding to each definition. An extensive process of 15 rounds of internal and external review was developed to exhaustively examine each definition, with decision‐making by collective opinion (consensus).

Results

A terminology report for female pelvic floor dysfunction, encompassing over 250 separate definitions, has been developed. It is clinically based with the six most common diagnoses defined. Clarity and user‐friendliness have been key aims to make it interpretable by practitioners and trainees in all the different specialty groups involved in female pelvic floor dysfunction. Female‐specific imaging (ultrasound, radiology, and MRI) has been a major addition while appropriate figures have been included to supplement and help clarify the text. Ongoing review is not only anticipated but will be required to keep the document updated and as widely acceptable as possible.

Conclusion

A consensus‐based terminology report for female pelvic floor dysfunction has been produced aimed at being a significant aid to clinical practice and a stimulus for research. Neurourol. Urodynam. 29: 4–20, 2010. © 2009 Wiley‐Liss, Inc.
Governmental financial information reforms and changes in the political system: The Argentina, Chile and Paraguay experience
Authors: Caba‐Perez Carmen , López‐Hernández Antonio M. , Ortiz‐Rodríguez David
Published: November 2009

This article analyzes the effects of changes in the political system‐from dictatorship to democracy‐on financial information systems and on their reform. We chose to study Argentina, Chile and Paraguay as these three countires share a similar geographic and social‐political context. They all had dictatorial governments during the second half of the 20th century and peformed a transition to democratic systems in the 1990s. We provide a brief overview of the political context and of government accounting regulations, both before and after the transition. We propose an adaptation of Lüder's contingency model to be applied to the situation in these three countries. This model enables us to identify the principal agents and motives favouring or prejudicing the implementation of reforms to financial information systems. Ours is the first academic study of reforms to government financial information systems in three Latin American countries that have made the transition from dictatorship to democracy, identifying the contingent factors that have affected the adoption of reforms. Copyright © 2009 John Wiley & Sons, Ltd.
Motivational dilemmas in collaborative learning activities: The case of the Swedish International Development Cooperation Agency (SIDA)
Authors: Andersson Krister
Published: November 2009

Complex social and environmental problems—such as climate change, rural poverty, and over‐fishing—defy simple policy solutions. An increasing number of scholars, practitioners, and policy makers now agree that coming to grips with such problems requires more collaborative and adaptive forms of learning and decision‐making. Such approaches seek to involve a variety of stakeholders to learn about system‐level effects of past human decisions and adapt future management decisions to the lessons learned. While there are plenty of success stories at the local level, the collaborative learning approach has turned out to be difficult to implement at broader scales—in large public organizations and in society at large. This article provides an explanation for such shortcomings, arguing that the creation of collaborative learning systems is plagued by several motivational dilemmas. By systematically mapping out the institutional incentives of the potential participants in collaborative learning activities, it is argued that one can gain a better understanding of the likelihood that adaptive systems will actually work. These ideas are tested on the case of the Swedish International Development Cooperation Agency (Sida). It is found that most Sida staff face conflicting incentives to engage in collaborative learning, but there are opportunities for management to strengthen such incentives. Copyright © 2009 John Wiley & Sons, Ltd.
Policy adoption in dynamic international environments: Evidence from national AIDS programs
Authors: Clark Benjamin Y.
Published: November 2009

The policy adoption is often seen as a function of internal determinants, external determinants, or a combination of the two. In the years since the start of the HIV/AIDS epidemic nearly every country in the world has adopted of some nature a program to combat the epidemic. This article demonstrates the mixed mechanisms influencing the adoption of AIDS programs, in a quantitative study of 90 countries. Prior studies have claimed that multilateral organizations were vital to global action against the HIV/AIDS epidemic. This study provides empirical evidence showing the actions taken by the multilateral organizations have both helped and hindered efforts to combat the HIV/AIDS epidemic. Copyright © 2009 John Wiley & Sons, Ltd.
Two‐dimensional proteome reference map for the radiation‐resistant bacterium Deinococcus geothermalis
Authors: Liedert Christina , Bernhardt Jörg , Albrecht Dirk , Voigt Birgit , Hecker Michael , Salkinoja‐Salonen Mirja , Neubauer Peter
Published: November 2009

2‐DE reference maps for Deinococcus geothermalis cytosolic and cell envelope proteomes were constructed. In total, 403 spots were identified as 299 different proteins. Unique in the proteomes were four subunits of V‐type ATPase and Deinococcus specific proteins constituting one‐fourth of cell envelope proteome. The cytoplasmic proteome included enzymes of the central carbon metabolism, chaperones, enzymes of protein and DNA repair, and oxidative stress. A total of 34 abundant proteins with unknown function may relate to the extreme stress tolerance of D. geothermalis.
Can telephone counseling post‐treatment improve psychosocial outcomes among early stage breast cancer survivors?
Authors: Marcus Alfred C. , Garrett Kathleen M. , Cella David , Wenzel Lari , Brady Marianne J. , Fairclough Diane , Pate‐Willig Meredith , Barnes Denise , Powell Emsbo Susan , Kluhsman Brenda C. , Crane Lori , Sedlacek Scot , Flynn Patrick J.
Published: November 2009

Objective: To determine whether a telephone counseling program can improve psychosocial outcomes among breast cancer patients post‐treatment.

Methods: A randomized trial was conducted involving 21 hospitals and medical centers, with assessments (self‐administered questionnaires) at baseline, 12 and 18 months post‐enrollment. Eligibility criteria included early stage diagnosis, enrollment during last treatment visit, and the ability to receive the intervention in English. Endpoints included distress (Impact of Event Scale), depression (Center for Epidemiologic Studies Depression Scale), and two study‐specific measures: sexual dysfunction and personal growth. The control group (n=152) received a resource directory for breast cancer; the intervention group (n=152) also received a one‐year, 16 session telephone counseling program augmented with additional print materials.

Results: Significant intervention effects were found for sexual dysfunction at 12 (p=0.03) and 18 months (p=0.04) and personal growth (12 months: p=0.005; 18 months: p=0.03). No differences by group were found in mean scores for distress and depression, with both groups showing significant improvement at 12 and 18 months (all p values for within‐group change from baseline were ⩽0.003). However, when dichotomized at cutpoints suggestive of the need for a clinical referral, the control group showed virtually no change at 18 months, whereas the intervention group showed about a 50% reduction in both distress (p=0.07) and depression (p=0.06).

Conclusions: Telephone counseling may provide a viable method for extending psychosocial services to cancer survivors nationwide. Copyright © 2010 John Wiley & Sons, Ltd.
Multifunctional Stretchable Plasma Polymer Modified PDMS Interface for Mechanically Responsive Materials
Authors: Geissler Alexandre , Vallat Marie‐France , Fioux Philippe , Thomann Jean‐Sébastien , Frisch Benoît , Voegel Jean‐Claude , Hemmerlé Joseph , Schaaf Pierre , Roucoules Vincent
Published: November 2009

New stretchable reactive surfaces are developed as platforms for the design of mechanically responsive materials. These surfaces are based on elastic PDMS elastomer substrates. Plasma polymerization leads to the attachment of reactive functionalities on the surface. We show that such functionalised PDMS surfaces exhibit pH‐dependent acid‐base properties due to the dicarboxylic acid groups. Both contact angle and force measurements highlight the dilution effect of the surface concentration of reactive groups induced by substrate elongation. We show, in particular, that the surfaces can be rendered antifouling by tailoring them with poly(ethylene glycol) ($\overline M _{\rm w}$ = 2000) and that the antifouling strength depends upon the elongation of the substrate.

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Synthesis and Energetic Properties of Bis‐(Triaminoguanidinium) 3,3′‐Dinitro‐5,5′‐Azo‐1,2,4‐Triazolate (TAGDNAT): A New High‐Nitrogen Material
Authors: Chavez David E. , Tappan Bryce C. , Mason Benjamin Aaron , Parrish Damon
Published: November 2009

This paper describes the synthesis and characterization of bis‐(triaminoguanidinium)‐3,3′‐dinitro‐5,5′‐azo‐1,2,4‐triazolate (TAGDNAT), a novel high‐nitrogen molecule that derives its energy release from both a high heat of formation and intramolecular oxidation reactions. TAGDNAT shows promise as a propellant or explosive ingredient not only due to its high nitrogen content (66.35 wt.‐%) but also due to its high hydrogen content (4.34 wt.‐%). This new molecule has been characterized with respect to its morphology, sensitivity properties, explosive, and combustion performance. The heat of formation of TAGDNAT was also experimentally determined. The results of these studies show that TAGDNAT has one of the fastest low‐pressure burning rates (at 6.9 MPa) measured till date, 6.79 cm s−1 at 6.9 MPa (39% faster than triaminoguanidinium azotetrazolate (TAGzT), a comparable high‐nitrogen/high‐hydrogen material). Furthermore, its pressure sensitivity is 0.507, a 33% reduction compared to TAGzT.
Differential effect of hot water treatment on whole tubers versus cut setts of yam (Dioscorea spp.)
Authors: Coyne Daniel L , Claudius‐Cole Abiodun O , Kenyon Lawrence , Baimey Hugues
Published: November 2009

BACKGROUND: The use of thermotherapy or hot water treatment (HWT) is recommended for the management of plant‐parasitic nematodes and other pathogens for a range of planting material, especially vegetatively propagated crops including yams, Dioscorea spp. The sprouting (germination) and consequent viability of yam following HWT, however, appear to be influenced by the post‐treatment method of planting (whole or cut setts) and cultivar. The present study was established to evaluate the sensitivity of the most popular yam cultivars in Benin and Nigeria, West Africa, to HWT at 50–53 °C for 20 min.

RESULTS: Sprouting of both setts and whole tubers of most cultivars was affected by HWT. Across experiments, 47% of HWT material, compared with 61% of non‐HWT material, sprouted over 8 weeks. When cut into setts, 41% of HWT or untreated tubers sprouted, compared with 72% of whole tubers. Whole, untreated tubers had highest sprouting rates (84%), and setts following HWT had the lowest (38%). Yam planting material was also not completely free of parasitic nematodes following HWT. The reaction to HWT or cutting was highly cultivar specific.

CONCLUSION: Yam cultivars vary in their sensitivity to hot water therapy. Care is therefore advised in selecting yam cultivars for HWT, especially when using cut setts. Copyright © 2009 Society of Chemical Industry
Evidence of effectiveness of herbal medicinal products in the treatment of arthritis
Authors: Cameron Melainie , Gagnier Joel J. , Little Christine V. , Parsons Tessa J. , Blümle Anette , Chrubasik Sigrun
Published: November 2009

Herbal medicinal products (HMPs) that interact with the mediators of inflammation are used in the treatment of rheumatoid arthritis (RA). The aim of this study was to update a previous systematic review published in 2000. We searched electronic databases (MEDLINE, EMBASE, CISCOM, AMED, CINAHL, Cochrane registers) to June 2007, unrestricted by date or language, and included randomized controlled trials that compared HMPs with inert (placebo) or active controls in patients with rheumatoid arthritis. Five reviewers contributed to data extraction. Disagreements were discussed and resolved by consensus with reference to Cochrane guidelines and advice from the Cochrane Collaboration.

Twenty studies (10 identified for this review update, and 10 of the 11 studies of the original review) investigating 14 HMPs were included. Meta‐analysis was restricted to data from previous seven studies with oils from borage, blackcurrant and evening primrose containing gamma linolenic acid (GLA). GLA doses equal or higher than 1400 mg/day showed benefit in the alleviation of rheumatic complaints whereas lower doses (∼500 mg) were ineffective. Three studies compared products fromTripterygium wilfordii(thunder god vine) to placebos and returned favorable results but data could not be pooled because the interventions and measures differed. Serious adverse effects occurred in one study. In a follow‐up study all side effects were mild to moderate and resolved after the intervention ceased, but time to resolution was variable. Two studies comparing Phytodolor NRto placebo were of limited use because some measures were poorly defined. The remaining studies, each considering differing HMPs, were assessed individually.

For most HMPs used in the treatment of RA, the evidence of effectiveness was insufficient to either recommend or discourage their use. Interventions with HMPs containing GLA orTripterygium wilfordiiextract appear to produce therapeutic effects but further investigations are warranted to prove their effectiveness and safety. Copyright © 2009 John Wiley & Sons, Ltd.
Structure‐Based Design of Benzoxazoles as new Inhibitors for D‐Alanyl – D‐Alanine Ligase
Authors: Tytgat Isabelle , Vandevuer Stéphane , Ortmans Isabelle , Sirockin Finton , Colacino Evelina , Van Bambeke Françoise , Duez Colette , Poupaert Jacques H. , Tulkens Paul M. , Dejaegere Annick , Prévost Martine
Published: November 2009

D‐Alanyl – D‐alanine ligase is an enzyme which catalyzes the dimerization of D‐alanine, and, as such, has an essential role in bacterial cell wall biosynthesis. It has been shown that inhibition of D‐alanyl – D‐alanine ligase prevents bacterial growth. D‐Alanyl – D‐alanine ligase represents therefore a viable antimicrobial target. The 3D structure of this enzyme complexed with a phosphinophosphate inhibitor has been reported, which allows for structure‐based design studies. Four softwares (LUDI, MCSS, Autodock, and Glide) developed either for fragment or full‐molecule docking were compared and scored for their ability to position in the active site four prototypic ligands: two inhibitors, i.e. a phosphinophosphate derivative and D‐cycloserine, D‐alanine and D‐alanyl – D‐alanine. Best performances were obtained with Glide and MCSS. A short series of novel derivatives based on a 2‐phenylbenzoxazole scaffold was designed de novo on the basis of computational data. The best compound was found to fully inhibit the D‐alanyl – D‐alanine ligase of E. faecalis with an IC50 of 400 μM.
D∞h B2(BS)2−/2− and Td B(BS)4−: Boron sulfide clusters containing BB multiple bonds and B− tetrahedral centers
Authors: Yao Wen‐Zhi , Guo Jin‐Chang , Lu Hai‐Gang , Li Si‐Dian
Published: November 2009

A density functional theory investigation on the geometrical and electronic properties of B4S (B2(BS)) and B5S (B(BS)) clusters has been performed in this work. Both the doublet B2(BS) ([SBBBBS]−) (D∞h, 2Πu) and the singlet B2(BS) ([SBBBBS]2−) (D∞h, 1Σ) proved to have perfect linear ground‐state structures containing a multiply bonded BB core (BB or BB) terminated with two BS groups, while Td B(BS) turned out to possess a perfect B− tetrahedral center directly corrected to four BS groups, similar to the corresponding boron hydride molecules of D∞h B2H, D∞h B2H, and Td BH, respectively. B4S2 and B5S4 neutrals, however, appeared to be much different: they favor a planar fan‐shaped C2v B4S2 (a di‐S‐bridged B4 rhombus) and a planar kite‐like C2v B5S4 (a di‐S‐bridged B3 triangle bonded to two BS groups), respectively. One‐electron detachment energies and symmetrical stretching vibrational frequencies are calculated for D∞h B2(BS) and Td B(BS) monoanions to facilitate their future characterizations. Neutral salts of B2(BS)2Li2 with an elusive BB triple bond and B(BS)4Li containing a tetrahedral B− center are predicted possible to be targeted in experiments. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
High‐lying core‐excited quartet states in Li‐like N4+ and F6+ ions
Authors: Zhuo Lin , Chen Feng , Gou Bing Cong
Published: November 2009

The variational method with mutilconfiguration interaction wave function is used to obtain the energies, fine structures, and hyperfine structures of high‐lying core‐excited quartet states 1s2lnl' 4Po(m) (m = 1–5) and 1s2pnp 4P(m) (m = 1–5) in Li‐like N4+ and F6+ ions, including the mass polarization and relativistic corrections. Restricted variational method is carried out to extrapolate a better energy. The oscillator strengths, lifetime, wavelengths, fine structure, and hyperfine structure for this system are also investigated to compare with other theoretical and experimental data in the literature. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
A correlated random‐effects model for normal longitudinal data with nonignorable missingness
Authors: Lin Huazhen , Liu Danping , Zhou Xiao‐Hua
Published: November 2009

The missing data problem is common in longitudinal or hierarchical structure studies. In this paper, we propose a correlated random‐effects model to fit normal longitudinal or cluster data when the missingness mechanism is nonignorable. Computational challenges arise in the model fitting due to intractable numerical integrations. We obtain the estimates of the parameters based on an accurate approximation of the log likelihood, which has higher‐order accuracy but with less computational burden than the existing approximation. We apply the proposed method it to a real data set arising from an autism study. Copyright © 2009 John Wiley & Sons, Ltd.
Adherence to antiretroviral therapy, virological response, and time to resistance in the Dakar cohort
Authors: Tournoud M. , Etard J. F. , Ecochard R. , DeGruttola V.
Published: November 2009

In 1998, with the launch of the Senegalese Initiative for Antiretroviral Access (ISAARV), Senegal became one of the first African countries to propose an antiretroviral access program. Our objective in this paper is to study the time to any first drug resistance, as well as predictors of the time to resistance. We propose a joint model to study the effect of adherence to the HAART therapy, and virological response on the time to resistance mutations. A logistic mixed model is used to model the time‐dependent adherence process; and a Markov model is used to study the virological response. Given the presence of missing data in the adherence process and in the virological response, the latent adherence and virological states are then included in the linear predictor of the time to resistance model. The proposed time to resistance model takes into account interval‐censored data as well as null hazard periods, during which the viral replication is very low. A Bayesian approach is used for accommodating with missing data and for prediction. We also propose model checking tools to study model adequacy. Copyright © 2009 John Wiley & Sons, Ltd.
A conditional maximized sequential probability ratio test for Pharmacovigilance
Authors: Li Lingling , Kulldorff Martin
Published: November 2009

The importance of post‐marketing surveillance for drug and vaccine safety is well recognized as rare but serious adverse events may not be detected in pre‐approval clinical trials. In such surveillance, a sequential test is preferable, in order to detect potential problems as soon as possible. Various sequential probability ratio tests (SPRT) have been applied in near real‐time vaccine and drug safety surveillance, including Wald's classical SPRT with a single alternative and the Poisson‐based maximized SPRT (MaxSPRT) with a composite alternative. These methods require that the expected number of events under the null hypothesis is known as a function of timet. In practice, the expected counts are usually estimated from historical data. When a large sample size from the historical data is lacking, the SPRTs are biased due to the variance in the estimate of the expected number of events. We present a conditional maximized sequential probability ratio test (CMaxSPRT), which adjusts for the uncertainty in the expected counts. Our test incorporates the randomness and variability from both the historical data and the surveillance population. Evaluations of the statistical power for CMaxSPRT are presented under different scenarios. Copyright © 2009 John Wiley & Sons, Ltd.
Logistic quantile regression for bounded outcomes
Authors: Bottai Matteo , Cai Bo , McKeown Robert E.
Published: November 2009

When research interest lies in continuous outcome variables that take on values within a known range (e.g. a visual analog scale for pain within 0 and 100 mm), the traditional statistical methods, such as least‐squares regression, mixed‐effects models, and even classic nonparametric methods such as the Wilcoxon's test, may prove inadequate. Frequency distributions of bounded outcomes are often unimodal, U‐shaped, and J‐shaped. To the best of our knowledge, in the biomedical and epidemiological literature bounded outcomes have seldom been analyzed by appropriate methods that, for one, correctly constrain inference to lie within the feasible range of values. In many respects, continuous bounded outcomes can be likened to probabilities or propensities. Yet, what has long been heeded when modeling the probability of binary outcomes with the widespread use of logistic and probit regression, so far appears to have been overlooked with continuous bounded outcomes with consequences at times disastrous. Logistic quantile regression constitutes an effective method to fill this gap. Copyright © 2009 John Wiley & Sons, Ltd.
Estimation of intervention effects using first or multiple episodes in clinical trials: The Andersen‐Gill model re‐examined
Authors: Cheung Yin Bun , Xu Ying , Tan Sze Huey , Cutts Felicity , Milligan Paul
Published: November 2009

Randomized trials of interventions against infectious diseases are often analyzed using data on first or only episodes of disease, even when subsequent episodes have been recorded. It is often said that the Andersen‐Gill (AG) model gives a biased estimate of intervention effect if there is event dependency over time. We demonstrate that, in the presence of event dependency, an effective intervention may have an indirect effect on disease risk at time tj via its direct effect on disease risk at time ti, i<j, and that the AG model estimates the total effect instead of the direct effect alone. From a clinical and public health perspective, estimation of the total effect is important. Previous simulation studies showed contradictory results about the performance of the AG model in the presence of unobserved heterogeneity across individuals. We show that some of the previous studies unintentionally created informative censoring in their data generating process by including only a certain maximum number of events per individual. We re‐ran some previous simulations with and without altering this maximum. With reference to the situations often seen in pneumococcal vaccine trials, we evaluated the performance of the Cox model for time to first episode and the AG model for multiple episodes. We applied these models to re‐analyze data from a pneumococcal conjugate vaccine trial. We maintain that a careful clarification of research purpose is needed before one can choose a statistical model, and that the AG model is useful in the estimation of the total effect of an intervention. Copyright © 2009 John Wiley & Sons, Ltd.
False discovery rate and permutation test: An evaluation in ERP data analysis
Authors: Lage‐Castellanos, Agustín , Martínez‐Montes Eduardo , Hernández‐Cabrera Juan A. , Galán Lídice
Published: November 2009

Current analysis of event‐related potentials (ERP) data is usually based on thea prioriselection of channels and time windows of interest for studying the differences between experimental conditions in the spatio‐temporal domain. In this work we put forward a new strategy designed for situations when there is nota prioriinformation about ‘when’ and ‘where’ these differences appear in the spatio‐temporal domain, simultaneously testing numerous hypotheses, which increase the risk of false positives. This issue is known as the problem of multiple comparisons and has been managed with methods that control the false discovery rate (FDR), such as permutation test and FDR methods. Although the former has been previously applied, to our knowledge, the FDR methods have not been introduced in the ERP data analysis. Here we compare the performance (on simulated and real data) of permutation test and two FDR methods (Benjamini and Hochberg (BH) and local‐fdr, by Efron). All these methods have been shown to be valid for dealing with the problem of multiple comparisons in the ERP analysis, avoiding thead hocselection of channels and/or time windows. FDR methods are a good alternative to the common and computationally more expensive permutation test. The BH method for independent tests gave the best overall performance regarding the balance between type I and type II errors. The local‐fdr method is preferable for high dimensional (multichannel) problems where most of the tests conform to the empirical null hypothesis. Differences among the methods according to assumptions, null distributions and dimensionality of the problem are also discussed. Copyright © 2009 John Wiley & Sons, Ltd.
Optimal group‐sequential designs for simultaneous testing of superiority and non‐inferiority
Authors: Öhrn Fredrik , Jennison Christopher
Published: November 2009

Confirmatory clinical trials comparing the efficacy of a new treatment with an active control typically aim at demonstrating either superiority or non‐inferiority. In the latter case, the objective is to show that the experimental treatment is not worse than the active control by more than a pre‐specified non‐inferiority margin. We consider two classes of group‐sequential designs that combine the superiority and non‐inferiority objectives: non‐adaptive designs with fixed group sizes and adaptive designs where future group sizes may be based on the observed treatment effect. For both classes, we derive group‐sequential designs meeting error probability constraints that have the lowest possible expected sample size averaged over a set of values of the treatment effect. These optimized designs provide an efficient means of reducing expected sample size under a range of treatment effects, even when the separate objectives of proving superiority and non‐inferiority would require quite different fixed sample sizes. We also present error spending versions of group‐sequential designs that are easily implementable and can handle unpredictable group sizes or information levels. We find the adaptive choice of group sizes to yield some modest efficiency gains; alternatively, expected sample size may be reduced by adding another interim analysis to a non‐adaptive group‐sequential design. Copyright © 2010 John Wiley & Sons, Ltd.
High Carbonyl Content Oxidized Starch Prepared by Hydrogen Peroxide and Its Thermoplastic Application
Authors: Zhang Shui‐Dong , Zhang Yu‐Rong , Wang Xiu‐Li , Wang Yu‐Zhong
Published: November 2009

Hydrogen peroxide was used to oxidize gelatinized starch to oxidized starch (OS) with degree of oxidation (DO) ranging from 0.096 to 0.554 depending on the H2O2/starch molar ratios used. Then glycerol was added to OS to produce thermoplastic oxidized starches (TPOS). Titrimetric determination of carboxyl and carbonyl groups, FT‐IR, 1H‐NMR and 13C‐NMR confirmed that at H2O2/starch molar ratios < 0.7, oxidized starch contained much more aldehyde than carboxyl groups, while at molar ratios up to 2.0, peroxide oxidation produced mainly carboxyl groups. Scanning electron microscopy (SEM) revealed that the oxidized starch particles (at DO 0.385) obtained a porous structure. The effect of DO on the structure and properties of OS, as well as mechanical properties and moisture resistance of TPOS was studied, respectively. With an increase in DO, the crystallinity, intrinsic viscosity and thermal stability of OS decreased markedly, the ability of OS to take up water decreased at low DO and increased at higher DO. These observations show that hydrogen peroxide can be used to oxidize starch in a controlled way. TPOS with DO 0.385 showed the best mechanical properties, its tensile strength was 6.1 MPa after placing in 100% relative humidity for 15 days.
The effect of axial beam force on moment–rotation curve of top and seat angels connections
Authors: Pirmoz Akbar , Danesh Fakhrodin , Farajkhah Vahid
Published: November 2009

Bolted top and seat angle connections are mainly designed to sustain gravitational loads of simply supported steel beams. However, the inherent flexural resistance of such connections may not be ignored when an accurate analysis of semirigid steel frames is desired. Current research aims at studying moment–rotation behaviour of this type under combined moment and axial tension force. Several refined three‐dimensional finite element models are created based on the previous experimental studies, and their accuracy is examined trough a comparison to test results from previous experimental studies. This study showed that the axial tension force reduces the connection initial stiffness and moment capacity. Based on the results obtained from analysing a series of finite element models under combined axial tension and moment loading, an equation is presented to estimate the affected moment–rotation response of such connections in terms of the connection geometrical properties, its moment–rotation response in the case of zero axial force and an expected axial tension force. Copyright © 2009 John Wiley & Sons, Ltd.
Seismic performance evaluation of tall and nonseismic‐designed wall‐type structures by shaking table tests
Authors: Park Tae‐Won , Chung Lan , Kim Jinkoo
Published: November 2009

Two 1/5‐scaled models of a nonseismic‐designed wall‐type structures were constructed and tested on a shaking table to evaluate their seismic performances. The prototype structure had shear walls only along the short side of the structure, which was a typical structural plan of apartment buildings constructed by tunnel forms before the seismic design code was enforced in Korea in 1989. Of the two models, one model was reinforced by steel angle sections placed on the walls and under the slabs for seismic retrofit. They were tested on a shaking table to investigate performance for earthquake ground excitations with various intensities. The experimental results showed that the nonseismic‐designed wall‐type structure without seismic retrofit failed to satisfy the life‐safety and collapse‐prevention performance objectives, whereas the retrofitted structure satisfied all the performance objectives. Copyright © 2009 John Wiley & Sons, Ltd.
Mean interference effects between two buildings: effects of close proximity
Authors: Amin J. A. , Ahuja A. K.
Published: November 2009

This paper presents the mean interference effects between a pair of buildings located in close proximity in a geometrical configuration of L‐ and T‐plan shapes. Experiments are carried out in a closed‐circuit wind tunnel on models of a 1:300 scale to measure the mean pressure distributions on two building models located in close proximity and on models in isolated position over an extended range of wind directions. The mean responses of buildings, namely block 1 and block 2 of L‐ and T‐shaped arrangements subjected to interference effects, are evaluated using the experimentally obtained wind loads and compared it with the responses of a similar building in isolation. Significant changes are observed in the responses of block 1 and block 2 of L‐ and T‐shaped arrangements as compared to a similar building in an isolated position. The interference levels are found to be dependent strongly on the angle of attack and the arrangement of the buildings with respect to each other. At wind incidence angle 0°, the presence of block 1 reduces the mean along the wind displacement of block 2 of the L‐ and T‐shaped arrangements up to 21% and 37%, respectively, as compared to a similar block in an isolated position. Copyright © 2009 John Wiley & Sons, Ltd.
A call for a new geoscience education research agenda
Authors: Lewis Elizabeth B. , Baker Dale R.
Published: November 2009

A lack of qualified teachers and low enrollment in the geosciences exist at both secondary and tertiary levels in the United States. Consequently, it is unlikely that students will be able to achieve scientific literacy without an increase in both of these populations. To address these problems, we pose research questions, highlight sociocultural theories, and provide examples of other science education research as possible avenues by which to explore these related problems. We argue that such research studies are necessary to inform science education policy and advance national scientific literacy. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:121–129, 2010
Major hepatectomy for perihilar cholangiocarcinoma
Authors: Unno Michiaki , Katayose Yu , Rikiyama Toshiki , Yoshida Hiroshi , Yamamoto Kuniharu , Morikawa Takanori , Hayashi Hiroki , Motoi Fuyuhiko , Egawa Shinichi
Published: November 2009

Background/purpose

Hilar cholangiocarcinoma and intrahepatic cholangiocarcinoma involving the hepatic hilus are defined as “perihilar cholangiocarcinoma”. The principle of surgical treatment is hemi‐hepatectomy or trisectionectomy of the liver, caudate lobectomy, and resection of the extrahepatic bile duct for complete resection of the tumor. The aim of this study was to review the outcomes of major hepatectomy for perihilar cholangiocarcinoma.

Methods

Using the Kaplan–Meier method and the Cox proportional hazards model, we analyzed the results in 125 patients with perihilar cholangiocarcinoma who had undergone major hepatectomy.

Results

Right hepatectomy, right trisectionectomy, left hepatectomy, and left trisectionectomy were performed in 66, 8, 49, and 2 patients, respectively. Curative resection was achieved in 79 patients (63.2%). Mortality and morbidity rates were 8.0 and 48.7%, respectively. The overall 1‐, 3‐, and 5‐year survival rates of all patients were 73.2, 36.7, and 34.7%, respectively. The median survival was 26.8 months. Multivariate analysis showed that the independent prognostic factors for overall survival were gender, histopathological grading, curative resection, and American Joint Committee on Cancer (AJCC)/International Union Against Cancer (UICC) pT.

Conclusions

Major hepatectomy for perihilar cholangiocarcinoma was acceptable and showed satisfactory outcomes. For long‐term survival in these patients, the surgeon should aim for complete resection of the tumor with negative margins.