bluuebunny/crossref_metadata_2025 huggingface dataset:
Major and minor depression in female adolescents: onset, course, symptom presentation, and demographic associations
Authors: Rohde Paul , Beevers Christopher G. , Stice Eric , O'Neil Kelly
Published: October 2009

We examined the epidemiology and phenomenology of major depressive disorder (MDD) and minor depression among a community sample of 496 female adolescents. Diagnostic interviews were conducted annually for 7 years, allowing us to examine onset, course, and symptom presentation among participants 12 through 20 years old. Approximately 1 of 6 girls experienced MDD. MDD episodes had a mean duration of 5.3 months (SD=4.2). One‐year prevalence for MDD peaked at age 16 (5.3%). White racial status and younger age were associated with greater worthlessness and suicidality during an MDD episode. One of 5 girls met criteria for minor depression. Adolescents from racial/ethnic minority groups were at especially high risk for minor depression. Adolescence is a high‐risk period for depression in young women, although its prevalence and phenomenology vary as a function of age and race/ethnicity. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65: 1–11, 2009.
Gender differences in the longitudinal structure of cognitive diatheses for depression in children and adolescents
Authors: Cole David A. , Jacquez Farrah M. , Truss Alanna E. , Pineda Ashley Q. , Weitlauf Amy S. , Tilghman‐Osborne Carlos E. , Felton Julia W. , Maxwell Melissa A.
Published: October 2009

In a school‐based, four‐wave, longitudinal study, children (grades 4–7) and young adolescents (grades 6–9) completed questionnaires measuring depressive symptoms and depressive cognitions, including positive and negative cognitions on the Cognitive Triad Inventory for Children (CTI‐C; Kaslow, Stark, Printz, Livingston, & Tsai, 1992) and self‐perceived competence on the Self‐Perception Profile for Children (SPPC; Harter, 1985). Application of the Trait‐State‐Occasion model (Cole, Martin, & Steiger, 2005) revealed the existence of a time‐invariant trait factor and a set of time‐varying occasion factors. Gender differences emerged, indicating that some cognitive diatheses were more trait‐like for girls than for boys (i.e., positive and negative cognitions on the CTI‐C; self‐perceived physical appearance and global self‐worth on the SPPC). Implications focus on the emergent gender difference in depression, the design of longitudinal studies, and clinical decisions about the implementation of prevention versus intervention programs. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65:1–15, 2009.
Problem solving moderates the effects of life event stress and chronic stress on suicidal behaviors in adolescence
Authors: Grover Kelly E. , Green Kelly L. , Pettit Jeremy W. , Monteith Lindsey L. , Garza Monica J. , Venta Amanda
Published: October 2009

The present study examined the unique and interactive effects of stress and problem‐solving skills on suicidal behaviors among 102 inpatient adolescents. As expected, life event stress and chronic stress each significantly predicted suicidal ideation and suicide attempt. Problem solving significantly predicted suicidal ideation, but not suicide attempt. Problem solving moderated the associations between life event stress and suicidal behaviors, as well as between chronic stress and suicidal ideation, but not chronic stress and suicide attempt. At high levels of stress, adolescents with poor problem‐solving skills experienced elevated suicidal ideation and were at greater risk of making a nonfatal suicide attempt. The interactive effects decreased to non‐significance after controlling for depressive symptoms and hopelessness. Clinical implications are discussed.© 2009 Wiley Periodicals, Inc. J Clin Psychol 65:1–10, 2009.
Postpartum depression: what we know
Authors: O'Hara Michael W.
Published: October 2009

Postpartum depression (PPD) is a serious mental health problem. It is prevalent, and offspring are at risk for disturbances in development. Major risk factors include past depression, stressful life events, poor marital relationship, and social support. Public health efforts to detect PPD have been increasing. Standard treatments (e.g., Interpersonal Psychotherapy) and more tailored treatments have been found effective for PPD. Prevention efforts have been less consistently successful. Future research should include studies of epidemiological risk factors and prevalence, interventions aimed at the parenting of PPD mothers, specific diathesis for a subset of PPD, effectiveness trials of psychological interventions, and prevention interventions aimed at addressing mental health issues in pregnant women. © 2009 Wiley Periodicals, Inc. J Clin Psychol 65:1–12, 2009.
Gas‐phase fragmentation of γ‐lactone derivatives by electrospray ionization tandem mass spectrometry
Authors: Crotti Antonio E. M. , Bronze‐Uhle Erika S. , Nascimento Paulo G. B. D. , Donate Paulo M. , Galembeck Sérgio E. , Vessecchi Ricardo , Lopes Norberto P.
Published: October 2009

Fragmentation reactions of β‐hydroxymethyl‐, β‐acetoxymethyl‐ and β‐benzyloxymethyl‐butenolides and the corresponding γ‐butyrolactones were investigated by electrospray ionization tandem mass spectrometry (ESI‐MS/MS) using collision‐induced dissociation (CID). This study revealed that loss of H2O [M + H −18]+ is the main fragmentation process for β‐hydroxymethylbutenolide (1) and β‐hydroxymethyl‐γ‐butyrolactone (2). Loss of ketene ([M + H −42]+) is the major fragmentation process for protonated β‐acetoxymethyl‐γ‐butyrolactone (4), but not for β‐acetoxymethylbutenolide (3). The benzyl cation (m/z 91) is the major ion in the ESI‐MS/MS spectra of β‐benzyloxymethylbutenolide (5) and β‐benzyloxymethyl‐γ‐butyrolactone (6). The different side chain at the β‐position and the double bond presence afforded some product ions that can be important for the structural identification of each compound. The energetic aspects involved in the protonation and gas‐phase fragmentation processes were interpreted on the basis of thermochemical data obtained by computational quantum chemistry. Copyright © 2009 John Wiley & Sons, Ltd.
Quantitative mineral analysis using Raman spectroscopy and chemometric techniques
Authors: Dörfer Thomas , Schumacher Wilm , Tarcea Nicolae , Schmitt Michael , Popp Jürgen
Published: October 2009

This paper presents four different ways to generate quantitative and qualitative mineral information out of a Raman mapping experiment. The results of the four methods are compared against each other, and the advantages and disadvantages are pointed out. The combination of the point‐counting method with chemometric approaches is presented for the first time. The method with its different possible techniques is explained in detail. It will be shown that this technique works best for minerals. Copyright © 2009 John Wiley & Sons, Ltd.
Detailed analysis of the charge transfer complex N,N‐dimethylaniline–SO2 by Raman spectroscopy and density functional theory calculations
Authors: Ando Rômulo A. , Matazo Deborah R. C. , Santos Paulo S.
Published: October 2009

Although the amine sulfur dioxide chemistry was well characterized in the past both experimentally and theoretically, no systematic Raman spectroscopic study describes the interaction between N,N‐dimethylaniline (DMA) and sulfur dioxide (SO2). The formation of a deep red oil by the reaction of SO2 with DMA is an evidence of the charge transfer (CT) nature of the DMA–SO2 interaction. The DMA–SO2 normal Raman spectrum shows the appearance of two intense bands at 1110 and 1151 cm−1, which are enhanced when resonance is approached. These bands are assigned to νs(SO2) and ν(ϕN) vibrational modes, respectively, confirming the interaction between SO2 and the amine via the nitrogen atom. The dimethyl group steric effect favors the interaction of SO2 with the ring π electrons, which gives rise to a π–π* low‐energy CT electronic transition, as confirmed by time‐dependent density functional theory (TDDFT) calculations. In addition, the calculated Raman DMA–SO2 spectrum at the B3LYP/6‐311 + + g(3df,3pd) level shows good agreement with the experimental results (vibrational wavenumbers and relative intensities), allowing a complete assignment of the vibrational modes. A better understanding of the intermolecular interactions in this model system can be extremely useful in designing new materials to absorb, detect, or even quantify SO2. Copyright © 2009 John Wiley & Sons, Ltd.
Geršgorin‐type localizations of generalized eigenvalues
Authors: Kostić V. , Cvetković L. J. , Varga R. S.
Published: October 2009

We introduce several localization techniques for the generalized eigenvalues of a matrix pair, obtained via the famous Geršgorin theorem and its generalizations. Specifically, we address the techniques of computing and graphing of the obtained localization sets of a matrix pair. The work that follows involves much about nonnegative matrices, strictly diagonally dominant (SDD) matrices, H‐ and M‐matrices. We show the utility of our results theoretically, as well as with numerical examples and graphs. Copyright © 2009 John Wiley & Sons, Ltd.
Adjoint‐weighted variational formulation for the direct solution of inverse problems of general linear elasticity with full interior data
Authors: Barbone Paul E. , Rivas Carlos E. , Harari Isaac , Albocher Uri , Oberai Assad A. , Zhang Yixiao
Published: October 2009

We describe a novel variational formulation of inverse elasticity problems given interior data. The class of problems considered is rather general and includes, as special cases, plane deformations, compressibility and incompressiblity in isotropic materials, 3D deformations, and anisotropy. The strong form of this problem is governed by equations of pure advective transport. The variational formulation is based on a generalization of the adjoint‐weighted variational equation (AWE) formulation, originally developed for flow of a passive scalar. We describe how to apply AWE to various cases, and prove several properties. We prove that the Galerkin discretization of the AWE formulation leads to a stable, convergent numerical method, and prove optimal rates of convergence. The numerical examples demonstrate optimal convergence of the method with mesh refinement for multiple unknown material parameters, graceful performance in the presence of noise, and robust behavior of the method when the target solution is C∞, C0, or discontinuous. Copyright © 2009 John Wiley & Sons, Ltd.
Self‐medication with antibiotics: questionnaire survey among primary care center attendants
Authors: Ilhan Mustafa N. , Durukan Elif , Ilhan Sevil Özger , Aksakal F. Nur , Özkan Seçil , Bumin Mehmet Ali
Published: October 2009

Purpose

The aim of this study was to determine the frequency and reasons for self‐medication with antibiotics within the last 12 months among primary healthcare center attendants aged 18 or over, in Ankara.

Methods

A questionnaire was applied by face to face interview technique to 2696 subjects attending at five primary healthcare centers. Information on demographic characteristics, intention to self‐medication with antibiotics and self‐medication within last 12 months were collected.

Results

It was found that 28% of the subjects were storing antibiotics at home. The percentage of self‐administering antibiotics was 19.1% in the last 12 months. The most common reasons for self‐administration of antibiotics were sore throat (59.6%), fever (46.2%), and cough (40.0%). Other reasons were dental infection, rheumatism, and fatigue. According to age groups, the most common self‐medicating group was those aged 40–49 with 23% while the least self‐usage was in the 60–69 age groups with 11.8%. Male sex, being single, educational level of secondary school or higher, being employed and not having social security increased self‐administration of antibiotics (p < 0.05).

Conclusions

The study indicated the need for legal regulations regarding the sale of antibiotics without prescription and, health education is required for the community to decrease the inappropriate use of antibiotics and self‐medication. Copyright © 2009 John Wiley & Sons, Ltd.
Tramadol dependence: a survey of spontaneously reported cases in Sweden
Authors: Tjäderborn Micaela , Jönsson Anna K , Ahlner Johan , Hägg Staffan
Published: October 2009

Background

Tramadol is a weak opioid analgesic, which is generally considered to be safe. However, conflicting data exist on the dependence potential of tramadol.

Objective

The aim of this study was to investigate occurrence of tramadol dependence and associated risk factors using spontaneously reported adverse drug reactions.

Methods

The Swedish database for spontaneously reported adverse drug reactions, Swedish Drug Information System (SweDIS), was searched for reports on tramadol dependence from 1 January 1995 until 31 December 2006. Selection was conducted based on the DSM‐IV definition of dependence. Available information was scrutinised and registered and then presented descriptively.

Results

A total of 104 reports of tramadol dependence were identified, of which 60 (58%) concerned women. The median age (range) was 45 (15–84) years. Information on a history of substance abuse was present in 31 patients (30%) and 41 patients (39%) had a documented past or current use of a drug of abuse. Prescribed doses of tramadol ranged between 50–800 mg/day, and ingested doses between 50–4000 mg/day. Time of onset ranged from some weeks up to 4 years. In 72 (69%) cases the reaction was classified as serious, mainly due to hospitalisations for detoxification or discontinuation of tramadol.

Conclusions

There is an occurrence of tramadol dependence in association with analgesic treatment within the recommended dose range. In susceptible patients a severe and serious dependence syndrome may develop. A history of abuse or use of a drug of abuse seems to be an important risk factor. Copyright © 2009 John Wiley & Sons, Ltd.
Steps to evaluating a statewide internship program: Model, trainee, and student outcomes
Authors: Morrison Julie Q. , Graden Janet L. , Barnett David W.
Published: October 2009

Internships play a pivotal role in the future of school psychology, and internship training is influenced by disciplinary trends including (a) an increased focus on accountability and demonstrating the positive impact of trainees' practices on student outcomes and (b) growing emphasis on scientifically based and empirically based practice. These influences also include greater sophistication in decision making as well as different ways of outcome‐focused decision making. System‐wide approaches such as Positive Behavior Support (PBS) and response to intervention (RTI) require high training demands to develop intervention‐related decision and accountability skills. Programmatically, accountability systems to meet the training needs of intervention services require scaling up. This article describes a multiyear developmental project bringing diverse universities together to institutionalize a statewide system of accountability. We share data from 3 years (N of interns = 278) and suggest recommendations for outcome‐oriented evaluation for other universities, agencies, school psychological services delivery units, or states. © 2009 Wiley Periodicals, Inc.
Early predictors of school engagement: Exploring the role of peer relationships
Authors: Perdue Neil H. , Manzeske David P. , Estell David B.
Published: October 2009

School engagement is an important theoretical and practical cornerstone to the promotion of school completion. The current study explores the influences of childhood peer relationships in the third grade predicting school engagement at Grade 5. Participants are among the National Institute of Child Health and Human Development Study of Early Child Care and Youth Development (Research Triangle Institute, 2002). Given the importance of evaluating school engagement as a complex developmental process, longitudinal and multi‐informant data were used to account for various child characteristics as well as relationships with parents that may affect school engagement. Results indicate that peer friendship quality, support from friends, and aggressive behavior toward peers all uniquely relate to school engagement. Implications for intervention are discussed. © 2009 Wiley Periodicals, Inc.
Microarray analysis reveals potential target genes of NF‐κB2/p52 in LNCaP prostate cancer cells
Authors: Nadiminty Nagalakshmi , Dutt Smitha , Tepper Clifford , Gao Allen C.
Published: October 2009

PURPOSE

Our previous studies showed that NF‐κB2/p52 is involved in the castration‐resistant growth of the androgen‐sensitive LNCaP prostate cancer cells. The role of NF‐κB2/p52 in lymphomagenesis has been studied extensively, but its target genes in other cancers remain unknown. In order to identify genes potentially regulated by p52 in prostate cancer cells, we performed a genome‐wide microarray analysis of genes differentially up‐ or down‐regulated by the overexpression of p52 by adenoviral‐mediated gene delivery in LNCaP cells.

EXPERIMENTAL DESIGN

Total RNAs from vector control‐infected and Adeno‐p52‐infected LNCaP cells were used to prepare cDNAs, which were hybridized to the Whole Genome Human 44k Microarray chips (Agilent Technologies). Data analysis was performed using GeneSpring and Ingenuity Pathway Analysis software. Validation of microarray results was performed by real‐time quantitative RT‐PCR and Western blot analyses.

RESULTS

Expression of ∼130 genes was differentially upregulated by >5‐fold, whereas ∼60 genes were differentially downregulated by >2‐fold in p52‐expressing LNCaP cells. Pathway analysis revealed that the upregulated genes belong to functional categories like cell growth and proliferation, cellular movement, cell‐to‐cell signaling and interaction, cancer, cell cycle, etc., whereas the downregulated genes were represented by functional categories like cell movement, antigen presentation, and cell death. Six of the top upregulated genes including annexin A2, PLAU, RND3, Twist2, VEGFC, and CXCL1 were validated by real‐time PCR and Western blot analysis.

CONCLUSIONS

This study provides a comprehensive analysis of genes potentially regulated by NF‐κB2/p52 in the LNCaP prostate cancer cell line and provides a rationale for the induction of castration‐resistant growth by p52 in LNCaP cells. Prostate 70: 276–287, 2010. © 2009 Wiley‐Liss, Inc.
Low‐density Taqman miRNA array reveals miRNAs differentially expressed in prostatic stem cells and luminal cells
Authors: Zhang Li , Zhao Wenping , Valdez Joseph M. , Creighton Chad J. , Xin Li
Published: October 2009

BACKGROUND

miRNAs are a class of naturally occurring small RNAs that generally repress gene expression. They have been shown to actively control diverse biological processes including stem cell differentiation and lineage commitment.

METHODS

Fluorescence‐activated cell sorting was utilized to isolate murine prostate stem cells and differentiated luminal cells. The expression levels of Drosha and Dicer1, the two key RNAseIII enzymes for miRNA maturation, were evaluated by quantitative RT‐PCR. Low‐density Taqman miRNA array analyses were also performed to identify miRNAs that are differentially expressed in individual lineages.

RESULTS

Drosha and Dicer1 are expressed at comparable transcriptional levels in murine prostate stem cells and differentiated luminal cells. Twenty‐nine miRNAs were discovered to be differentially expressed in prostate stem cells and luminal cells. Many of these miRNAs are coded in clusters, suggesting a cell‐specific transcriptional regulation. Some of these differentially expressed miRNAs have been reported to regulate genes relevant to the molecular and phenotypic features of each lineage.

CONCLUSIONS

miRNAs may play a potentially critical role in fine regulation of prostatic lineage identity. Prostate 70: 297–304, 2010. © 2009 Wiley‐Liss, Inc.
Microwave‐assisted solid‐phase peptide synthesis at 60 °C: alternative conditions with low enantiomerization
Authors: Loffredo Carina , Assunção Nilson A. , Gerhardt Juergen , Miranda M. Terêsa Machini
Published: October 2009

Several conditions have been used in the coupling reaction of stepwise SPPS at elevated temperature (SPPS‐ET), but we have elected the following as our first choice: 2.5‐fold molar excess of 0.04–0.08 M Boc or Fmoc‐amino acid derivative, equimolar amount of DIC/HOBt (1:1) or TBTU/DIPEA (1:3), 25% DMSO/toluene, 60 °C, conventional heating. In this study, aimed to further examine enantiomerization under such condition and study the applicability of our protocols to microwave‐SPPS, peptides containing L‐Ser, L‐His, L‐Cys and/or L‐Met were manually synthesized traditionally, at 60 °C using conventional heating and at 60 °C using microwave heating. Detailed assessment of all crude peptides (in their intact and/or fully hydrolyzed forms) revealed that, except for the microwave‐assisted coupling of L‐Cys, all other reactions occurred with low levels of amino acid enantiomerization (<2%). Therefore, herein we (i) provide new evidences that our protocols for SPPS at 60 °C using conventional heating are suitable for routine use, (ii) demonstrate their appropriateness for microwave‐assisted SPPS by Boc and Fmoc chemistries, (iii) disclose advantages and limitations of the three synthetic approaches employed. Thus, this study complements our past research on SPPS‐ET and suggests alternative conditions for microwave‐assisted SPPS. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Evaluation of an extract of Brazilian arnica (Solidago chilensis Meyen, asteraceae) in treating lumbago
Authors: da Silva Ary G. , de Sousa Carlos P. G. , Koehler Jaeder , Fontana Joelder , Christo Alexandre G. , Guedes‐Bruni Rejan R.
Published: October 2009

One of the Brazilian arnicas, Solidago chilensis Meyen, is a species of the family Asteraceae. This plant is known by this common name because it shares very similar organoleptic properties with the genus Arnica L., also within the family Asteraceae, that comprises approximately 30 European species of perennial, herbaceous plants. The effectiveness of a fluid extract of S. chilensis used externally for treating lumbago was examined in placebo‐controlled double‐blind clinical pharmacological studies. Two daily skin applications of a gel containing a 5% extract in glycol were administered for 15 days to ten volunteers in a placebo group and to an equal number in a test group. Statistical analyses of the results demonstrated a significant reduction in the perception of pain and a significant increase in the flexibility of patients in the test group as compared with those receiving only the placebo. Copyright © 2009 John Wiley & Sons, Ltd.
Antibiofilm phenylethanoid glycosides from Penstemon centranthifolius
Authors: Ye Miao , Zhao Yun , Norman Vanessa L. , Starks Courtney M. , Rice Stephanie M. , Goering Matt G. , O'Neil‐Johnson Mark , Eldridge Gary R. , Hu Jin‐Feng
Published: October 2009

Bioassay‐guided fractionation of the antibacterial ethyl acetate‐ethanol (50 : 50) extract obtained from the aerial parts of Penstemon centranthifolius led to the isolation of six phenylethanoid glycosides (1–6) and eleven iridoid glycosides (7–17). Their structures were determined on the basis of spectroscopic analysis and comparison with the literature. Among them, two phenylethanoid glycosides, 4″′‐O–acetylverbascoside (1) and verbascoside (2), were found to show significant inhibition of the formation of bacterial biofilms by Escherichia coli UTI89. Compound 1 showed 77% biofilm inhibition at 2.5 µg/mL, and compound 2 showed 60% inhibition at 5 µg/mL. Copyright © 2009 John Wiley & Sons, Ltd.
Absence of mutagenic effects of a particular Symphytum officinale L. liquid extract in the bacterial reverse mutation assay
Authors: Benedek Birgit , Ziegler Andreas , Ottersbach Peter
Published: October 2009

Comfrey (Symphytum officinale L.) root is traditionally used for the topical treatment of contusions, strains and sprains. Besides allantoin and rosmarinic acid, which are discussed as pharmacologically active principles, the drug contains pyrrolizidine alkaloids (PAs) known for their hepatotoxic, carcinogenic and mutagenic properties. The topical herbal medicinal products Kytta‐Salbe® f and Kytta‐Plasma® f contain a PA‐free liquid extract from comfrey root as active substance. The aim of this study was to demonstrate the absence of genotoxic effects of this special extract in the bacterial reverse mutation assay (Ames test).

Briefly, comfrey root liquid extract was investigated for its ability to induce gene mutations in Salmonella typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 with and without metabolic activation using the mammalian microsomal fraction S9 mix. Reference mutagens were used to check the validity of the experiments.

Comfrey root fluid extract showed no biologically relevant increases in revertant colony numbers of any of the five tester strains, neither in the presence nor in the absence of metabolic activation. In conclusion, the comfrey root fluid extract contained in Kytta‐Salbe® f and Kytta‐Plasma® f was not mutagenic in the bacterial reverse mutation assay. Copyright © 2009 John Wiley & Sons, Ltd.
Inhibition of quorum‐sensing signals by essential oils
Authors: Szabó Mira Ágnes , Varga Gábor Zoltán , Hohmann Judit , Schelz Zsuzsanna , Szegedi Ernő , Amaral Leonard , Molnár József
Published: October 2009

The role of quorum sensing (QS) is well known in microbial pathogenicity and antibiotic resistance. QS is responsible for motility, swarming, and biofilm production based on the signal molecules, e.g., acylated homoserine lactones (AHLs) produced by micro‐organisms above certain population density. The inhibition of QS may reduce pathogenicity, antibiotic resistance and biofilm formation in systemic and local infections. The homoserine lactones and other transmitters contribute to antibiotic resistance and pathogenicity of several bacteria; consequently the inhibition of QS signals reduces the problem of resistance and virulence. Due to the increasing number of persistent non‐treatable infections, there is an urgent need to develop new strategies to combat infections that destabilize bacterial communities in the host.

The effect of essential oils on bacterial growth and QS were evaluated using the sensor strain Chromobacterium violaceum CV026 and N‐acyl homoserine lactone (AHL) producing Escherichia coli ATTC 31298 and the grapevine colonizing Ezf 10‐17 strains. Of the tested oils, rose, geranium, lavender and rosemary oils were the most potent QS inhibitors. Eucalyptus and citrus oils moderately reduced pigment production by CV026, whereas the chamomile, orange and juniper oils were ineffective. Copyright © 2009 John Wiley & Sons, Ltd.
Copper‐catalyzed phosphinidene transfer to ethylene, acetylene, and carbon monoxide: A computational study
Authors: Amme Matthew J. , Kazi Abul B. , Cundari Thomas R.
Published: October 2009

A DFT study of phosphinidene transfer by copper model catalysts is reported. PR‐transfer pathways are highly exergonic with respect to catalyst and phosphinidene transfer reagent. Calculated free energy barriers by which (dhpe)Cu(PMe) active species yields functionalized products are reasonable for modeled substrates—ethylene, acetylene, and carbon monoxide. Calculations suggest a (dhpe)CuI(‐PMe·−) formulation as more appropriate than (dhpe)CuII(=PMe2−). The preferred pathway for production of phosphirane (phosphirene) is via direct [1 + 2] addition of ethylene (acetylene) to the PMe group of (dhpe)Cu(PMe), which contrasts the [2 + 2] mechanism for the reaction of ethylene with Ni0‐phosphinidenes. In light of simulations for neutral and cationic models, it is concluded that the extra electron in copper destabilizes [2 + 2] pathways. Calculated energetics for (dhpe)Cu(PMe) versus (en)Cu(PMe), dhpe = 1,2‐bis(dihydrophosphino)ethane, en = ethylenediamine, indicate that the former is a more potent for PR‐transfer. Thus, it is inferred that modifications that result in a more electron deficient metal center will yield better group transfer catalysts. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
The self‐assembled of cyclic D,L‐α‐peptide systems: Insights into the structure and energetics
Authors: Qu Wenwen , Tan Hongwei , Chen Guangju , Liu Ruozhuang
Published: October 2009

Cyclic D,L‐α‐peptides are able to self‐assemble to nanotubes, although the inherent reason of the stability of this kind of nanotube as well as the intrinsic driving force of self‐assembly of the cyclic D,L‐α‐peptides still remain elusive. In this work, using several computational approaches, we investigated the structural and energy characteristics of a series of cyclo[(‐L‐Phe‐D‐Ala‐)4] and cyclo[(‐L‐Ala‐D‐Ala‐)4] oligomers. The results reveal that the thermodynamic stability, cooperativity, and self‐assembly patterns of cyclic D,L‐α‐peptide nanotubes are mainly determined by the interactions between cross‐strand side chains instead of those between backbones. For cyclo[(‐L‐Phe‐D‐Ala‐)4] oligomers, the steric interaction between cross‐strand side chains, especially the electrostatic repulsion between the phenyls in Phe residues, brings anticooperative effect into parallel stacking mode, which is responsible for the preference of self‐assembling nanotube in antiparallel vs. parallel stacking orientation. Based on our results, a novel self‐assembling mechanism is put forward—it is the L‐L antiparallel dimer of cyclo[(‐L‐Phe‐D‐Ala‐)4], instead of the commonly presumed monomer, that acts as the basic building block in self assembly. It explains why these cyclic peptides uniquely self‐assemble to form antiparallel nanotubes. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Theoretical study of electron transfer in uranyl(VI)–uranyl(V) complexes in solution
Authors: Lu Shen‐Zhuang
Published: October 2009

The rates of the electron self‐exchange between uranyl(VI) and uranyl(V) complexes in solution have been investigated in detail with quantum chemical methods. The calculations have shown that the bond length of UOyl is elongated by 0.1 Å when the extra electron is localized on the sites. The diabatic potential surfaces are obtained. The inner reorganization energies are 212.6 and 226.8 kJ mol−1 for hydroxide and fluoride bridge systems, respectively. The solvent reorganization energies are 28.12 and 31.60 kJ mol−1 for hydroxide and fluoride bridge systems, respectively. The nuclear frequency factors are 3.17 × 1013 and 3.12 × 1013 s−1 for hydroxide and fluoride bridge systems, respectively. The electronic coupling matrix elements are 1.89 and 4.06 kJ mol−1 for hydroxide and fluoride bridge systems, respectively. The electron‐transfer rates of our calculations are 12.95 and 0.819 M−1 s−1 for hydroxide and fluoride bridge systems, respectively. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Effect of the interelectronic repulsion on the information content of position and momentum atomic densities
Authors: Angulo J. C. , López‐Rosa S. , Antolín J.
Published: October 2009

The interelectronic repulsion is strongly responsible of the main structural characteristics of the atomic densities and, in particular, of their level of information content. In this work, the effect of such a repulsion on some information‐theoretic descriptors is quantified and analyzed by considering different complexities and distances between the Bare Coulomb Field (BCF) and the Hartree–Fock (HF) position and momentum densities of neutral atoms throughout the Periodic Table. In doing so, the Quantum Similarity Index (QSI), the Quadratic Distance (QD), the Jensen‐Shannon (JSD) and Fisher (FD) Divergences as well as complexity measures are employed. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Effect of solvents having different dielectric constants on reactivity: A conceptual DFT approach
Authors: Kar Rahul , Pal Sourav
Published: October 2009

Conceptual density functional theory is exploited to understand the reactivity in a medium of solvents with increasing dielectric constants. Aprotic as well as protic solvents are used for this study. It is found that the global parameters, such as chemical potential and hardness, decrease from gas phase to solvent phase with increasing dielectric constant. However, it is observed that the Fukui functions of the reactive atoms increase significantly with the dielectric constants of the aprotic solvents while for the protic solvents the variation of the reactivity indices is insignificant. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Theoretical prediction on HBeN− and HNBe− anions using multiconfiguration second‐order perturbation theory
Authors: Li Wen‐Zuo , Cheng Jian‐Bo , Zhong Li Qing‐ , Gong Bao‐An , Sun Jia‐Zhong
Published: October 2009

The HBeN− and HNBe− anions have been investigated for the first time using the CASSCF, CASPT2, and DFT/B3LYP methods with the contracted atomic natural orbital (ANO) and cc‐pVTZ basis sets. The geometries of all stationary points along the potential energy surfaces were optimized at the CASSCF/ANO and B3LYP/cc‐pVTZ levels. The ground and the first excited states of HBeN− are predicted to be X2Π and A2Σ+ states, respectively. It was predicted that the ground state of HNBe− is X2Σ+ state. The A2Π state of HNBe− has unique imaginary frequency. A bend local minimum M1 was found along the 12A″ potential energy surface and the A2Π state of HNBe− should be the transition state of the isomerization reactions for M1 ↔ M1. The CASPT2/ANO potential energy curves of isomerization reactions were calculated as a function of HBeN bond angle. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Recombinant immobilized rhizopuspepsin as a new tool for protein digestion in hydrogen/deuterium exchange mass spectrometry
Authors: Rey Martial , Man Petr , Brandolin Gérard , Forest Eric , Pelosi Ludovic
Published: October 2009

Hydrogen/deuterium (H/D) exchange coupled to mass spectrometry is nowadays routinely used to probe protein interactions or conformational changes. The method has many advantages, e.g. very low sample consumption, but offers limited spatial resolution. One way to higher resolution leads through the use of different proteases or their combinations. In the present work we describe recombinant production, purification and use of aspartic protease zymogen from Rhizopus chimensis, protease type XVIII (EC 3.4.23.6), commonly referred to as rhizopuspepsinogen (Rpg). The enzyme was expressed in Escherichia coli, refolded and purified to homogeneity. A typical yield was approximately 100 mg of pure enzyme per 1 L of original bacterial culture. The kinetics of protease activation, i.e. removal of the propeptide achieved by autolysis in an acidic environment, was followed by mass spectrometry. The digestion efficiency was tested for the protease in solution as well as for the immobilized enzyme. Apomyoglobin was successfully digested under all conditions tested and the protease displayed very low or no autodigestion. The results outperformed those obtained with commercial protease where the digestion of apomyoglobin was incomplete and accompanied by many contaminating peptides. Taken together, the recombinant protease type XVIII can be considered as a new and highly efficient tool for H/D exchange followed by mass spectrometry. Copyright © 2009 John Wiley & Sons, Ltd.
Optimizing mass spectrometric detection for ion chromatographic analysis. I. Common anions and selected organic acids
Authors: Wang Jinyuan , Schnute William C.
Published: October 2009

We describe a systematic method of optimizing mass spectrometric (MS) detection for ion chromatographic (IC) analysis of common anions and three selected organic acids using response surface methodology (RSM). RSM was utilized in this study because it minimized the number of experiments required to achieve the optimum MS response and included the interactions between individual parameters for multivariable optimization. Five MS parameters, including probe temperature, nebulizer gas, assistant makeup flow, needle voltage and cone voltage, were screened and systematically optimized by two steps. Central composite design (CCD) was used to design the experiment points and a quadratic model was applied to fit the experimental data. Analysis of variance (ANOVA) was carried out to evaluate the validity of the statistical model and to determine the most significant parameters for MS response. The optimum MS conditions for each analyte were summarized and the method optimum condition was achieved by applying desirability function. Our observation showed good agreements between statistically predicted optimum response and the responses collected at the predicted optimum condition. Operable range of each parameter (with normalized MS response greater than 0.8 for each analyte) was provided for general anionic IC/MS applications. Copyright © 2009 John Wiley & Sons, Ltd.
HIV fusion inhibitors
Authors: Qadir M. I. , Malik S. A.
Published: October 2009

Drugs based on amino acid sequence of Heptad Repeats of gp41 of HIV have been explored in search of anti‐HIV drugs acting by inhibition of the gp41 6‐helix formation and subsequent cellular infection. These are classified under a distinct discipline called HIV fusion inhibitors. Resistance to HIV fusion inhibitors and their solutions have also been discussed in this review. Copyright © 2009 John Wiley & Sons, Ltd.
Improved nonlinear trajectory tracking using RBFNN for a robotic helicopter
Authors: Lee Chi‐Tai , Tsai Ching‐Chih
Published: October 2009

This paper presents a backstepping control method using radial‐basis‐function neural network (RBFNN) for improving trajectory tracking performance of a robotic helicopter. Many well‐known nonlinear controllers for robotic helicopters have been constructed based on the approximate dynamic model in which the coupling effect is neglected; their qualitative behavior must be further analyzed to ensure that the unmodeled dynamics do not destroy the stability of the closed‐loop system. In order to improve the controller design process, the proposed controller is developed based on the complete dynamic model of robotic helicopters by using an RBFNN function approximation to the neglected dynamic uncertainties, and then proving that all the trajectory tracking error variables are globally ultimately bounded and converge to a neighborhood of the origin. The merits of the proposal controller are exemplified by four numerical simulations, showing that the proposed controller outperforms a well‐known controller in (J. Robust Nonlinear Control2004;14(12):1035–1059). Copyright © 2009 John Wiley & Sons, Ltd.
Decentralized control of discrete‐time linear time invariant systems with input saturation
Authors: Deliu Ciprian , Malek Babak , Roy Sandip , Saberi Ali , Stoorvogel Anton A.
Published: October 2009

We study decentralized stabilization of discrete‐time linear time invariant (LTI) systems subject to actuator saturation using LTI controllers. The requirement of stabilization under both saturation constraints and decentralization imposes obvious necessary conditions on the open‐loop plant, namely that its eigenvalues are in the closed unit disc and further that the eigenvalues on the unit circle are not decentralized fixed modes. The key contribution of this work is to provide a broad sufficient condition for decentralized stabilization under saturation. Specifically, we show through an iterative argument that the stabilization is possible: whenever (1) the open‐loop eigenvalues are in the closed unit disc; (2) the eigenvalues on the unit circle are not decentralized fixed modes; and (3) these eigenvalues on the unit circle have algebraic multiplicity of 1. Copyright © 2009 John Wiley & Sons, Ltd.
Observer‐based H∞ control for systems with repeated scalar nonlinearities and multiple packet losses
Authors: Dong Hongli , Wang Zidong , Gao Huijun
Published: October 2009

This paper is concerned with the H∞ control problem for a class of systems with repeated scalar nonlinearities and multiple missing measurements. The nonlinear system is described by a discrete‐time state equation involving a repeated scalar nonlinearity, which typically appears in recurrent neural networks. The measurement missing phenomenon is assumed to occur, simultaneously, in the communication channels from the sensor to the controller and from the controller to the actuator, where the missing probability for each sensor/actuator is governed by an individual random variable satisfying a certain probabilistic distribution in the interval [0 1]. Attention is focused on the analysis and design of an observer‐based feedback controller such that the closed‐loop control system is stochastically stable and preserves a guaranteed H∞ performance. Sufficient conditions are obtained for the existence of admissible controllers. It is shown that the controller design problem under consideration is solvable if certain linear matrix inequalities (LMIs) are feasible. Three examples are provided to illustrate the effectiveness of the developed theoretical results. Copyright © 2009 John Wiley & Sons, Ltd.
Direct sequence spectrum spreading techniques for next generation mobile broadband satellite services
Authors: Kim Pansoo , Vanelli‐Coralli Alessandro , Villanti Marco , Pedone Raffaella , Cioni Stefano , Neri Massimo , Palestini Claudio , Papaleo Marco , Lee Ho‐Jin , Corazza Giovanni E.
Published: October 2009

The recently approved mobile version of the Digital Video Broadcasting Return Channel via Satellite (DVB‐RCS+M) foresees the use of direct sequence spectrum spreading (DS‐SS) in the forward link. The addition of a spreading mode, on top of the conventional time division signaling structure of the fixed DVB‐S2, allows in fact for the efficient extension of DVB‐S2 to mobile terminals with small aperture antennas operating in Ku (11–14 GHz) and Ka (20–30 GHz) bands. Spectrum spreading has been introduced to augment the received energy without increasing the transmitted power density, which is limited by regulatory constraints, and to enhance the waveform resilience to co‐channel interference. In this paper, we report on the design and assessment of the DS‐SS technique that we carried out for its inclusion in the DVB‐RCS+M standard. In particular, by comparing the physical layer performance of the spread and nonspread modes in the specific DVB‐RCS+M mobile scenarios, we show that the proposed DS‐SS technique has no impact on the DVB‐RCS+M data detection performance, while satisfying the requirements on interference resilience and received energy augmentation. In order to deal with the acquisition issues raised by the introduction of the DS‐SS technique, we then propose and evaluate several synchronization sub‐systems able to deal with the specific impairments of the mobile satellite scenarios, that is, large frequency offsets, phase noise, link obstructions, etc. Finally, a possible implementation of the DS‐SS technique that fully accommodates the reuse of the specific hardware compatible with conventional DVB‐S2 is also reported. Copyright © 2009 John Wiley & Sons, Ltd.
Fabrication of nanodot plasmonic waveguide structures using FIB milling and electron beam‐induced deposition
Authors: Dhawan Anuj , Gerhold Michael , Madison Andrew , Fowlkes Jason , Russell Phillip E. , Vo‐Dinh Tuan , Leonard Donovan N.
Published: October 2009

Fabrication of metallic Au nanopillars and linear arrays of Au‐containing nanodots for plasmonic waveguides is reported in this article by two different processes—focused ion beam (FIB) milling of deposited thin films and electron beam‐induced deposition (EBID) of metallic nanostructures from an organometallic precursor gas. Finite difference time domain (FDTD) modeling of electromagnetic fields around metallic nanostructures was used to predict the optimal size and spacing between nanostructures useful for plasmonic waveguides. Subsequently, a multi‐step FIB fabrication method was developed for production of metallic nanorods and nanopillars of the size and geometry suggested by the results of the FDTD simulations. Nanostructure fabrication was carried out on planar substrates including Au‐coated glass, quartz, and mica slides as well as cleaved 4‐mode optical fibers. In the second fabrication process, EBID was utilized for the development of similar nanostructures on planar Indium Tin Oxide and Titanium‐coated glass substrates. Each method allows formation of nanostructures such that the plasmon resonances associated with the nanostructures could be engineered and precisely controlled by controlling the nanostructure size and shape. Linear arrays of low aspect ratio nanodot structures ranging in diameter between 50–70 nm were fabricated using EBID. Preliminary dark field optical microscopy demonstrates differences in the plasmonic response of the fabricated structures. SCANNING 31: 139–146, 2009. © 2009 Wiley Periodicals, Inc.
DISA: Detection and isolation of sneaky attackers in locally monitored multi‐hop wireless networks
Authors: Khalil Issa , Bagchi Saurabh , AbuAli Najah , Hayajneh M.
Published: October 2009

Local monitoring has been demonstrated as a powerful technique for mitigating security attacks in multi‐hopad hocnetworks. In local monitoring, nodes overhear partial neighborhood communication to detect misbehavior such as packet drop or delay. However, local monitoring as presented in the literature is vulnerable to a class of attacks that we introduce here calledstealthy packet dropping. Stealthy packet dropping disrupts the packet from reaching the destination by malicious behavior at an intermediate node. However, the malicious node gives the impression to its neighbors that it performed the legitimate forwarding action. Moreover, a legitimate node comes under suspicion. We introduce four ways of achieving stealthy packet dropping, none of which is currently detectable. We provide a protocol called DISA, based on local monitoring, to remedy each attack. DISA incorporates two techniques—having the neighbors maintain additional information about the routing path, and adding some checking responsibility to each neighbor. We show through analysis and simulation that basic local monitoring (BLM) fails to efficiently mitigate any of the presented attacks while DISA successfully mitigates them. Copyright © 2009 John Wiley & Sons, Ltd.
Hierarchical testing of multiple endpoints in group‐sequential trials
Authors: Glimm Ekkehard , Maurer Willi , Bretz Frank
Published: October 2009

We consider the situation of testing hierarchically a (key) secondary endpoint in a group‐sequential clinical trial that is mainly driven by a primary endpoint. By ‘mainly driven’, we mean that the interim analyses are planned at points in time where a certain number of patients or events have accrued on the primary endpoint, and the trial will run either until statistical significance of the primary endpoint is achieved at one of the interim analyses or to the final analysis. We consider both the situation where the trial is stopped as soon as the primary endpoint is significant as well as the situation where it is continued after primary endpoint significance to further investigate the secondary endpoint. In addition, we investigate how to achieve strong control of the familywise error rate (FWER) at a pre‐specified significance level α for both the primary and the secondary hypotheses. We systematically explore various multiplicity adjustment methods. Starting point is a naive strategy of testing the secondary endpoint at level α whenever the primary endpoint is significant. Hung et al. (J. Biopharm. Stat. 2007; 17:1201–1210) have already shown that this naive strategy does not maintain the FWER at level α. We derive a sharp upper bound for the rejection probability of the secondary endpoint in the naive strategy. This suggests a number of multiple test strategies and also provides a benchmark for deciding whether a method is conservative or might be improved while maintaining the FWER at α. We use a numerical example based on a real case study to illustrate the results of different hierarchical test strategies. Copyright © 2009 John Wiley & Sons, Ltd.