bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydroxylation and Ring‐Opening Mechanism of an Unusual Flavoprotein Monooxygenase, 2‐Methyl‐3‐hydroxypyridine‐5‐carboxylic Acid Oxygenase: A Theoretical Study
Authors: Tian Boxue , Tu Yaoquan , Strid Åke , Eriksson Leif A.
Published: January 2010

Hybrid meta‐GGA density functional theory (the MPWB1K functional) was used to study the hydroxylation and ring‐opening mechanism of 2‐methyl‐3‐hydroxypyridine‐5‐carboxylic acid oxygenase (MHPCO). This enzyme catalyses the conversion of 2‐methyl‐3‐hydroxypyridine‐5‐carboxylic acid (MHPC) to α‐(N‐acetylaminomethylene)succinic acid (AAMS), which is the essential ring‐opening step in the bacterial degradation of vitamin B6. MHPCO belongs to the flavin‐containing aromatic hydroxylases family. However, MHPCO is capable of catalysing a subsequent aromatic ring‐cleavage reaction to give acyclic products rather than hydroxylated aromatic ones. Our calculations show that the re‐aromatisation of the hydroxylated intermediate occurs spontaneously in aqueous solution; this implies that the ring‐opening process occurs inside the enzyme’s active site, in which limited water is available. The instability of the hydroxylated intermediate of MHPCO is the main reason why acyclic products are formed. Previously proposed mechanisms for the ring‐opening step were studied, and were shown to be less likely to occur (ΔΔG≠298>35 kcal mol−1). Two new pathways with reasonable barrier heights (ΔΔG≠298<15 kcal mol−1) are reported herein, which are in accordance with all experimental information present to date.
Surfactant‐Encapsulated Polyoxometalates as Immobilized Supramolecular Catalysts for Highly Efficient and Selective Oxidation Reactions
Authors: Qi Wei , Wang Yizhan , Li Wen , Wu Lixin
Published: January 2010

A type of interesting immobilized supramolecular catalysts based on surfactant‐encapsulated polyoxometalates has been developed for oxidation reactions. Through a sol‐gel process with tetraethyl orthosilicate, hydroxyl‐terminated surfactant‐encapsulated polyoxometalate complexes have been covalently and uniformly bound to a silica matrix with unchanged complex structure. The formed hybrid catalysts possess a defined hydrophobic nano‐environment surrounding the inorganic clusters, which is conducive to compatibility between the polyoxometalate catalytic centres and organic substrates. The supramolecular synergy between substrate adsorption, reaction, and product desorption during the oxidation process has been found to have an obvious influence on the reaction kinetics, with the activity of the catalyst being greatly improved. The supramolecular catalysts performed effectively in the selective oxidation of several different kinds of organic compounds, such as alkenes, alcohols, and sulfides, and the main products were the corresponding epoxides, ketones, sulfoxides, and sulfones. More significantly, the catalyst could be easily recovered by simple filtration, and the catalytic activity was well retained for at least five cycles. Finally, the present strategy has proved to be a general route for the fabrication of supramolecular hybrid catalysts containing common polyoxometalates suitable for various purposes.
A Selective 3‐Acylation of Tetramic Acids and the First Synthesis of Ravenic Acid
Authors: Schlenk Andrea , Diestel Randi , Sasse Florenz , Schobert Rainer
Published: January 2010

3‐Acyltetramic acids, including delicate 3‐oligoenoyl derivatives, such as the Penicillium metabolite ravenic acid, were prepared in two high‐yielding steps. Reaction of tetramic acids with the ylide Ph3PCCO afforded exclusively the corresponding 3‐acylylidenetetramic acids. These were amenable to Wittig olefinations with aliphatic, aromatic, saturated and unsaturated aldehydes after deprotonation with KOtBu. Due to its simplicity, selectivity and tolerance of pH‐sensitive groups this method is superior to the established acylation protocols by Jones and Yoshii. It is also applicable to the synthesis of 3‐acyltetronic acids. The new 3‐oligoenoyl tetramic acids exhibited structure‐dependent antimicrobial and cytotoxic activity.
Self‐Association of Bis‐Dendritic Organogelators: The Effect of Dendritic Architecture on Multivalent Cooperative Interactions
Authors: Seo Myungeun , Kim Jung Hak , Kim Jisung , Park Nojin , Park Jeyoung , Kim Sang Youl
Published: January 2010

A series of bis‐dendritic gelators consisting of a benzamide dendron and an alkyl dendron were synthesized to investigate the dendritic effect on self‐assembly. The gelators with a first‐generation benzamide (benzamide‐G1) dendron or a first‐generation alkyl (alkyl‐G1) dendron formed stable gels in most aromatic solvents, and their self‐assembled fibrillar networks were imaged by electron microscopy. The unbranched molecule (G0‐G0) or the molecule possessing a second‐generation benzamide (benzamide‐G2) dendron did not form gels. Differential scanning calorimetry, powder X‐ray diffraction, and Fourier transform IR studies revealed that introduction of a dendritic branch strongly affected the molecular packing as well as the strength of intermolecular interactions. Furthermore, concentration‐dependent diffusion coefficient measurements and the evaluation of association constants by1H NMR spectroscopy indicated that bis‐dendritic gelators with a benzamide‐G1dendron possessed high association constants and formed large aggregates, whereas molecules with a single benzamide formed dimers in chloroform. The formation of self‐assembled fibrillar networks was driven by the multivalent and cooperative hydrogen bonding observed in the benzamide‐G1dendrons. π–π stacking of aromatic groups and van der Waals interactions between alkyl chains also played roles in the self‐assembly process, thus indicating that a spatial balance between two dendrons is important.
Spontaneous Hierarchical Assembly of Crown Ether‐like Macrocycles into Nanofibers and Microfibers Induced by Alkali‐Metal and Ammonium Salts
Authors: Hui Joseph K.‐H. , Frischmann Peter D. , Tso Chien‐Hsin , Michal Carl A. , MacLachlan Mark J.
Published: January 2010

Schiff base macrocycle 1, which has a crown ether like central pore, was combined with different alkali‐metal and ammonium salts in chloroform, resulting in one‐dimensional supramolecular aggregates. The ion‐induced self‐assembly was studied with solid‐state NMR spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). It was found that the lengths and widths of the superstructures depend on the cation and counteranion of the salts. Among the salts being used, Na+ and NH4+ ions with BF4− ions showed the most impressive fibrous structures that can grow up to 1 μm in diameter and hundreds of microns in length. In addition, the size of the fibers can be controlled by the evaporation rate of the solvent. A new macrocycle with bulky triptycenyl substituents that prevent supramolecular assembly was prepared and did not display any nanofibers with alkali‐metal ions in chloroform when studied with TEM.
Self‐Assembly of Discrete Homochiral, Helical, Hydrogen‐Bonded Nanocages: From Vesicles to Microspheres and Tubules Capable of Gelating Solvents
Authors: Yan Liwei , Xue Ying , Gao Ge , Lan Jingbo , Yang Fan , Su Xiaoyu , You Jingsong
Published: January 2010

The chiral tris‐monodentate imidazolinyl ligands 1 a–c exhibit a strong tendency to form the discrete, helical [2+3] nanocages 3 ([12⋅23]) with tartaric acids 2. Circular dichroism (CD) spectra and theoretical calculations reveal that supramolecular handedness of capsulelike architectures is determined only by the chirality of the imidazolinyl ligands rather than tartaric acids. The chirality of imidazolinyl ligands is transferred to the helicity of the complexes through the directed hydrogen bonds between the N3 atom of imidazoline rings and the carboxyl of tartaric acids. These hydrogen‐bonded nanocages can spontaneously self‐assemble into spherical vesicles, during which the hydrogen bonding that arises from the hydroxyl groups of tartaric acids plays a crucial issue. The vesicles formed by [{(S,S,S)‐1 a}2(2L)3] (3 a) may further evolve into microspheres that gelate organic solvents after being aged at −20 °C for 24 h, and can also be unprecedentedly transformed to tubular assemblies capable of rigidifying the solvents when subjected to ultrasound irradiation.
Synthesis, Structures, and Properties of Fused Thiophenes for Organic Field‐Effect Transistors
Authors: Liu Ying , Di Chong‐an , Du Chunyan , Liu Yunqi , Lu Kun , Qiu Wenfeng , Yu Gui
Published: January 2010

A series of fused thiophenes composed of fused α‐oligothiophene units as building blocks, end‐capped with either styrene or 1‐pentyl‐4‐vinylbenzene groups, has been synthesized through Stille coupling reactions. The compounds have been fully characterized by means of 1H NMR spectrometry, high‐resolution mass spectrometry, and elemental analysis. The molecules present a trans–trans configuration between their double bonds, which has been verified and confirmed by Fourier‐transform infrared spectroscopy and single‐crystal X‐ray diffraction analysis. The X‐ray crystal structures showed π–π overlap and sulfur–sulfur interactions between the adjacent molecules. The decomposition temperatures were all found to be above 300 °C, indicating that compounds of this series possess excellent thermal stability. The fact that no phase transition occurs at low temperature indicates that they should be well‐suited for application in devices. Moreover, they possess low HOMO energy levels, based on cyclic voltammetry measurements, and suitable energy gaps, as determined from their thin‐film UV/Vis spectra. Thin‐film X‐ray diffraction analysis and atomic force microscopy revealed high crystallinity on supporting substrates. In addition, as the substrate temperature has a significant influence on the morphology and the degree of crystallinity, the device performance could be optimized by varying the substrate temperature. These materials were found to exhibit optimal field‐effect performance, with a mobility of 0.17 cm2 V−1 s−1 and an on/off ratio of 105, at a substrate temperature of 70 °C.
Radical Arylation of Phenols, Phenyl Ethers, and Furans
Authors: Wetzel Alexander , Pratsch Gerald , Kolb Roman , Heinrich Markus R.
Published: January 2010

Radical arylations of para‐substituted phenols and phenyl ethers proceeded with good regioselectivity at the ortho position with respect to the hydroxy or alkoxy group. The reactions were conducted with arenediazonium salts as the aryl radical source, titanium(III) chloride as the reductant, and diluted hydrochloric acid as the solvent. Substituted biaryls were obtained from hydroxy‐ and alkoxy‐substituted benzylamines, phenethylamines, and aromatic amino acids. The methodology described offers a fast, efficient, and cost‐effective new access to diversely functionalized biphenyl alcohols and ethers. Free phenolic hydroxy groups, aromatic and aliphatic amines, as well as amino acid substructures, are well tolerated. Two examples for the applicability of the methodology are the partial synthesis of a β‐secretase inhibitor and the synthesis of a calcium‐channel modulator.
Bestimmung kinetischer Parameter der FADH2‐abhängigen Tryptophan‐5‐Halogenase aus Streptomyces rugosporus
Authors: Muffler K. , Kuetchou Ngnigha A. R. , Ulber R.
Published: January 2010

Biokatalysatoren zur regioselektiven Halogenierung bestimmter Substrate sind mittlerweile verfügbar. Ein Einsatz solcher Halogenasen zur Bereitstellung halogenierter (Zwischen‐) Produkte bietet im Vergleich zur klassischen Halogenierung den Vorteil, dass sie weitgehend nebenproduktfrei abläuft und keine toxischen Halogenierungsagentien zur Anwendung kommen. Beispielhaft wird hier die Untersuchung kinetischer Parameter einer Tryptophan‐5‐Halogenase beschrieben.
Charakterisierung von Cellulasepräparationen mittels Streulicht
Authors: Spiess A. C. , Wulfhorst H. , Jäger G. , Ellinidou E. , Büchs J.
Published: January 2010

Die selektive enzymatische Hydrolyse von Lignocellulose ist einer der kritischen Schritte der stofflichen und energetischen Nutzung von Biomasse und benötigt Methoden zum Screening und zur Charakterisierung der Biokatalysatoren im Hochdurchsatz. Die BioLector‐Technik detektiert den enzymatischen Abbau suspendierter α‐Cellulose anhand abnehmender Streulichtintensität. Es wurden kinetische Parameter und das pH‐Optimum eines kommerziellen Cellulasepräparates ermittelt und so die Eignung der BioLector‐Technik zur Hochdurchsatzcharakterisierung gezeigt.
Potenzial von Prozessintegration mit Adsorbern zur Herstellung seltener Monosaccharide – eine modellbasierte Untersuchung
Authors: Bechtold M. , Füreder M. , Wagner N. , Panke S.
Published: January 2010

Enzymatische Isomerisierungsreaktionen ermöglichen die Synthese seltener Monosaccharide wie D‐Psicose oder D‐Tagatose, die potenziell sehr interessant sind als Bausteine für Pharmaprodukte oder Süßstoffe. Um solche Reaktionen industriell anzuwenden, muss aber das Gleichgewichtsproblem gelöst werden: Isomerisierungen weisen typischerweise eine ungünstige Lage des thermodynamischen Gleichgewichts auf und lassen somit nur limitierte Ausbeuten zu. In situ‐Produktabtrennung stellt eine interessante Prozessoption dar, um die Umsatzlimitierung zu überwinden. In dieser Arbeit werden zwei Prozessvarianten zur Integration von enzymatischer Isomerisierung und Adsorption in einer modellbasierten Untersuchung verglichen: zum einen die direkte Integration im Satzreakor, die eine sehr einfache Betriebsweise darstellt. Allerdings kann hier nur mit hochselektiven und hoch beladbaren Adsorbermaterialien, die es zudem erst noch zu entwickeln gilt, eine hohe Ausbeute bei hoher Produktivität erreicht werden. Mit momentan zur Verfügung stehenden Adsorbern ist, wenn überhaupt, nur eine minimale Steigerung möglich. Zum anderen wurde die Integration von kontinuierlicher Simulated Moving Bed (SMB)‐Trennung, Enzymmembranreaktor und Nanofiltration theoretisch untersucht. Konkret konnte mithilfe von modellgestützten Optimierungen gezeigt werden, dass unter Verwendung von kostengünstigem Ionentauschermaterial für die SMB‐Zuckertrennung wettbewerbsfähige Produktivitäten bei praktisch vollständiger Ausbeute erreicht werden können.
Identifizierung und Expression neuer Biokatalysatoren
Authors: Leggewie C. , Puls M. , Eggert T.
Published: January 2010

Die begrenzten fossilen (Energie‐) Ressourcen der Erde werden in den nächsten Jahren dazu führen, dass in vielen Bereichen ein Umdenken stattfinden muss. Dazu gehört auch die nachhaltige Herstellung von Chemikalien bzw. daraus resultierenden Produkten des täglichen Lebens. Einen bedeutenden Beitrag hierzu kann die Biokatalyse leisten. Chemische (Produktions‐) Prozesse können durch den alternativen Einsatz von enzymatisch katalysierten Umsetzungen durch die so genannten Biokatalysatoren ökologischer und häufig auch ökonomischer durchgeführt werden. Für die meisten Stoffumsetzungen stehen allerdings keine oder nur unzureichend geeignete Biokatalysatoren zur Verfügung. Eine große Herausforderung der kommenden Jahre und Jahrzehnte ist also die Identifizierung neuer, spezifischer Enzyme, die ebenfalls in ausreichenden Mengen produziert werden müssen. Dieser Artikel gibt einen Überblick der neuen Entwicklungen und Fortschritte auf diesem Gebiet.
Early (sentinel lymph node biopsy‐guided) versus delayed lymphadenectomy in melanoma patients with lymph node metastases
Authors: Pasquali Sandro , Mocellin Simone , Campana Luca G. , Bonandini Elena , Montesco Maria C. , Tregnaghi Alberto , Del Fiore Paolo , Nitti Donato , Rossi Carlo R.
Published: January 2010

BACKGROUND:

It is debated whether patients with melanoma who undergo lymphadenectomy after a positive sentinel lymph node (SN) biopsy (SNB) have a better prognosis compared with patients who are treated for clinically evident disease.

METHODS:

The records of 190 patients with cutaneous melanoma who underwent radical lymph node dissection after a positive SNB (completion lymph node dissection [CLND]; n = 100) or who had clinically evident lymph node metastasis (therapeutic lymph node dissection [TLND]; n = 90) were analyzed. Moreover, the MEDLINE, EMBASE, and Cochrane databases were searched for studies that investigated the survival impact of SNB‐guided CLND compared with TLND for clinically evident disease. Standard meta‐analysis methods were used to calculate the overall treatment effect across eligible studies.

RESULTS:

In the authors' series, tumor characteristics did not differ significantly between patients who underwent CLND and those who underwent TLND. After a median follow‐up of 52.6 months, the 5‐year overall survival rate did not differ significantly between CLND patients and TLND patients (68.9% vs 50.4%, respectively; log‐rank test; P = .17). In contrast, a meta‐analysis of 6 studies (n = 2633) that addressed this issue (including the authors' own series) indicated that there was a significantly higher risk of death for patients who underwent TLND compared with that for patients who underwent CLND (hazard ratio, 1.60; 95% confidence interval, 1.28‐2.00; P < .0001).

CONCLUSIONS:

Although no significant survival difference was observed in either series, the pooling of summary data from all the studies that dealt with this issue suggested that SNB‐guided CLND is associated with a significantly better outcome compared with TLND for clinically evident lymph node disease. Cancer 2010. © 2010 American Cancer Society.
Kleinste Teile, größter Nutzen
Authors: Michaeli Walter , Kamps Thomas
Published: January 2010

Mikrosystemtechnik: Wie Ingenieure nach neuen Wegen zur Herstellung von Bauelementen suchen
Anxiety and its correlates among older adults accessing aging services
Authors: Richardson Thomas M. , Simning Adam , He Hua , Conwell Yeates
Published: January 2010

Objectives

To assess the characteristics of anxiety in aging services network (ASN) clients.

Methods

Interviews were conducted as part of an academic‐community partnership for studying the mental health needs of community‐dwelling older adults. Participants consisted of ASN clients in Monroe County, NY, that were aged 60 years and older and received an in‐home assessment for care management services. The Goldberg Anxiety Scale screened for anxiety symptoms, and instruments covering the domains of associated mental health, physical health and disability, social support, negative life events, and other areas relevant to delivery of aging services were administered.

Results

Of 378 subjects enrolled, 27% had clinically significant levels of anxiety. In bivariate analyses anxiety was associated with having a current major depressive episode (MDE), five or more medical conditions, pain, younger age, less income, and negative life events. After controlling for MDE in multivariate analyses, medical conditions, pain, negative life events, and younger age were significant correlates of anxiety in ASN clients.

Conclusions

Anxiety was common among ASN clients who received in‐home care management services. These anxious clients suffered from a combination of mental, medical, and social issues that suggests the need for multidisciplinary care. Because aging services providers work with their clients to ameliorate conditions that are highly correlated with anxiety, the ASN represents a promising venue for detecting, managing, and preventing anxiety among older adults. Copyright © 2010 John Wiley & Sons, Ltd.
The Brazilian national health system: an unfulfilled promise?
Authors: Ocké‐Reis Carlos Octávio , Marmor Theodore R.
Published: January 2010

In 1988, Brazil became one of the first countries in Latin America to frame access to health care as a constitutional right. However, it would be misleading to call Brazil's Unified Health System (Sistema Único de Saúde, or SUS) a public health system that provides universal access and comprehensive care. This paper reveals a strong contradiction between the re‐distribution model set out in the Brazilian Constitution and the inadequate level of public spending on health care. The law states that health care is a basic social right, allocated by need rather than means. Meanwhile, in 2003, Brazil spent US$ 597 per capita on health, or 7.6 per cent of its gross domestic product (GDP), while the average country from the Organization for Economic Cooperation and Development (OECD) spent US$ 3145, or 10.8 per cent, and Argentina spent US$ 1067, or 8.9 per cent of its GDP. Copyright © 2010 John Wiley & Sons, Ltd.
On the use of planning models in the operating theatre: results of a survey in Flanders
Authors: Cardoen Brecht , Demeulemeester Erik , Van der Hoeven Jessie
Published: January 2010

This paper presents an overview of the operating theatre planning and scheduling practice of hospitals in Flanders (Belgium). An electronic survey was sent to 95 hospitals in which surgeries are performed, which eventually resulted in a response set of 52 hospitals (55%). The questionnaire did not only focus on issues related to the elective (inpatient and outpatient) planning and scheduling process, but also questioned how hospitals currently deal with the occurrence of non‐elective surgeries (urgencies and emergencies). We indicate what goals health managers try to achieve and how this planning is established. We furthermore pay attention to some possible disruptions to the schedule and the corresponding anticipatory methods. Despite the proliferation of computerized planning and scheduling procedures proposed by the scientific community, the implementation rate of satisfying technological planning or evaluation systems still seems to be low. In order to increase the operating theatre efficiency, a closer cooperation between the academic institutions and the practitioners should be encouraged. Copyright © 2010 John Wiley & Sons, Ltd.
Hospitalization in Tajikistan: determinants of admission, length of stay, and out‐of‐pocket expenditures. Results of a national survey
Authors: Habibov Nazim
Published: January 2010

Objective

To assess factors explaining hospitalization in Tajikistan and discuss policy implications for reforms in hospital care.

Methods

This study involves a secondary analysis of micro‐data collected from a nationally‐representative household survey conducted in Tajikistan in 2003. Three empirical models are employed: binomial logit regression for the admission to the hospital; zero truncated negative binomial (ZTNB) regression for the length of hospital stay; and ordinary least square (OLS) for the amount of out‐of‐pocket expenditures for hospitalization.

Findings

Variation in hospital admission is due to the differences in ability to pay, long‐standing illness, gender, age, and educational level. Factors explaining out‐of‐pocket expenditures include ability to pay, having long‐standing illness, and having surgery and receiving intensive care. The most important out‐of‐pocket expenditures are payments for pharmaceuticals and supplies. Finally, long hospital stay that is the result of outdated treatment protocols, rigid financial and management system, lack of funding, and weakness of primary and long‐tem care. As a result, long time in inpatient care is mostly used ineffectively.

Conclusion

Strategies to address the existing deficiencies include voluntary community‐based health insurance for rural areas, targeted subsidized care for the neediest, improvements in procurement of pharmaceuticals and supplies, and rationalization of hospital primary and long‐term care. Copyright © 2010 John Wiley & Sons, Ltd.
Service utilization patterns for presumed infertile women in the Islamic republic of Iran, 2004–2005
Authors: Ardalan Ali , Vahidi Serajeldin , Mohammad Kazem , Russel Mehdi
Published: January 2010

Understanding the utilization pattern of infertility health and medical services can assist health system managers in providing better and more efficient care to affected population. This study aims to investigate the patterns in the utilization of infertility services in Iran.

We performed a survey of 10 783 women in 28 provinces from 2004 to 2005. We used a systematic sampling method to draw a total of 400 clusters, the probability for selection being proportional to the size of the urban and rural population in each province. The categorization of the woman as “presumed infertile” was based on her own report of infertility at some time during her married life. We also studied the measures taken for the latest episode of presumed infertility. For each of these measures, we recorded the reason(s), the year in which it was taken, and the time interval separating it from contraceptive discontinuation. Data analysis, using the software package STATA 8.0, included descriptive statistics and computation of 95% confidence intervals (CI) as well as χ2 and logistic regression procedures adapted to the complex sampling design.

A total of 1592 women had presumed infertility at some period after their marriage (14.8%, CI0.95 = 13.8–15.7%), and 1291 subjects had taken measures to deal with the problem (81.1%, CI0.95 = 78.7–83.5%). These rates did not show any significant differences between urban and rural women (p > 0.05). In 70% of these cases, the first measure was a visit to a specialist physician and in 70% the woman had sought care in the private sector. Visits to specialists and private health care facilities had increased over the last three decades, with fewer visits to general practitioners (GPs) and midwives and less use of self‐medication or traditional/local therapies. The most common motive for those who had not taken any treatment was their unwillingness to have their problem known and discussed by others (29.3%). The determinants of treatment‐seeking behavior were current primary infertility (OR = 4.15, CI0.95 = 2.53–6.80), higher education (OR = 1.39, CI0.95 = 1.04–1.86) and living with husband (OR = 1.83, CI0.95 = 1.01–3.32).

The current study is the first attempt to present a population‐based pattern of service utilization by infertile women in Iran. It shows that for these patients, the first contact with the health system takes the form of a visit to a specialist physician, and is more likely to involve the private sector. Copyright © 2010 John Wiley & Sons, Ltd.
So glad you came! Harm reduction therapy in community settings
Authors: Little Jeannie , Franskoviak Perri
Published: January 2010

Harm reduction therapy was originally developed as a nonabstinence‐based method of treating people with drug and alcohol problems. In this article, we describe and apply the principles and practices of harm reduction therapy in community settings, places where people congregate for nontherapeutic reasons—street corners, community drop‐in centers, needle exchanges, and primary care clinics. Low‐threshold welcome and flexible session arrangements are defining characteristics of this community‐based approach. We have been instrumental in developing several programs, three of which are described here. These programs work with more than 1,000 clients per year, with varying levels of intensity. The programs offer drop‐in or sidewalk sessions, drop‐in support groups, regular therapy appointments, and psychiatric medications. Many impressive outcomes, such as reduction of harmful drug use, stabilization of psychiatric problems, and permanent housing, are found each year. © 2010 Wiley Periodicals, Inc. J Clin Psychol: In Session 66: 1–14, 2010.
Determination of methylene blue residues in aquatic products by liquid chromatography‐tandem mass spectrometry
Authors: Xu Jin‐Zhong , Dai Lin , Wu Bin , Ding Tao , Zhu Jun‐Jie , Lin Hong , Chen Hui‐Lan , Shen Chong‐Yu , Jiang Yuan
Published: January 2010

A method for the determination and confirmation of methylene blue (MB) in aquatic products was developed. Residues of MB were extracted from homogenized tissues with acetonitrile/sodium acetate buffer solution, and simply cleaned up with dichloromethane liquid/liquid extraction. After concentration and dissolution, the sample solutions were cleaned up by the neutral alumina and weak cation‐exchange solid phase extraction (SPE) cartridge, prior to LC‐MS/MS analysis. MB was determined at 1.0–20 μg/kg in eel, toasted eel and shrimp, with a limit of quantification of 0.5 μg/kg. Recovery for MB was between 73.0% and 108.3%. This method is fast, exact and sensitive. It can be applied to determine MB in aquatic products.
Determination of amitraz and 2,4‐dimethylaniline residues in honey by using LC with UV detection and MS/MS
Authors: Xu Jin‐Zhong , Miao Jian‐Jun , Lin Hong , Ding Tao , Zhao Zhen‐Yun , Wu Bin , Shen Chong‐Yu , Jiang Yuan
Published: January 2010

A method for the determination and confirmation of amitraz and its degradation product 2,4‐dimethylaniline (2,4‐DMA) in honey is reported. Determination of the two compounds was based on HPLC with UV detection and MS/MS (LC‐MS/MS) after a liquid–liquid extraction with hexane and isopropyl alcohol. Chromatographic separation was achieved by using a C18 column with a gradient mobile phase consisting of 0.02 M ammonium acetate and ACN. Recoveries for fortified honey ranged from 83.4 to 103.4% for amitraz and from 89.2 to 104.7% for 2,4‐DMA with RSD values lower than 11.6% for HPLC and LC‐MS/MS methods. LOD was 6 μg/kg for amitraz and 8 μg/kg for 2,4‐DMA, while LOQ was 20 μg/kg for amitraz and 25 μg/kg for 2,4‐DMA in HPLC method. LOD was 1 μg/kg for amitraz and 2 μg/kg for 2,4‐DMA, while LOQ was 5 μg/kg for amitraz and 10 μg/kg for 2,4‐DMA in LC‐MS/MS method.
Optimization of dispersive liquid–liquid microextraction of Co(II) and Fe(III) as their oxinate chelates and analysis by HPLC: Application for the simultaneous determination of Co(II) and Fe(III) in water samples
Authors: Farajzadeh Mir Ali , Bahram Morteza , Vardast Mohammad Reza
Published: January 2010

In this study, dispersive liquid–liquid microextraction method was used for the preconcentration and simultaneous determination of Co(II) and Fe(III) in water samples as their oxinate chelates. In dispersive liquid–liquid microextraction process, methanol and chloroform were used as disperser and extracting solvents, respectively, and the ligand 8‐hydroxy quinoline was used as a chelating agent for the extraction of Co(II) and Fe(III). HPLC was applied for the quantitation of the analytes after preconcentration. An experimental design, central composite design, coupled with response surface methodology was used for the optimization of the involved experimental parameters. In addition, the effect of various experimental parameters in the extraction was investigated using one variable at a time method. The calibration graphs were linear in the range of 20–4000 μg/L with the LODs of 3 μg/L for both analytes. The RSDs for six replicate measurements of 500 μg/L of Co2+ and Fe3+ were 3.3 and 4.1%, respectively.
Simultaneous determination of nucleosides, myriocin, and carbohydrates in Cordyceps by HPLC coupled with diode array detection and evaporative light scattering detection
Authors: Wang Shuang , Yang Feng‐qing , Feng Kun , Li De‐qiang , Zhao Jing , Li Shao‐ping
Published: January 2010

A HPLC coupled with diode array detection (DAD) and evaporative light scattering detection (ELSD) method for qualitative and quantitative analysis of eight nucleosides and nucleobases, three carbohydrates and myriocin in Cordyceps was developed. A Prevail Carbohydrate ES column was employed for the separation within 50 min. Nucleosides and their bases were tested at UV 254 nm. ELSD was connected with DAD to determine myriocin and carbohydrates. The optimum drift tube temperature of ELSD was at 94°C with the nitrogen flow rate of 2.0 L/min. All calibration curves showed good linearity (R2>0.9933) during the test ranges. The precision, repeatability, accuracy, LOD and LOQ were also fully investigated. This developed method was successfully applied to quantify 12 components, eight nucleosides and nucleobases, three carbohydrates and myriocin, in natural and cultured Cordyceps, which provides another view for quality control of Cordyceps sinensis.
III‐V/silicon photonics for on‐chip and intra‐chip optical interconnects
Authors: Roelkens G. , Liu L. , Liang D. , Jones R. , Fang A. , Koch B. , Bowers J.
Published: January 2010

In this paper III‐V on silicon‐on‐insulator (SOI) heterogeneous integration is reviewed for the realization of near infrared light sources on a silicon waveguide platform, suitable for inter‐chip and intra‐chip optical interconnects. Two bonding technologies are used to realize the III‐V/SOI integration: one based on molecular wafer bonding and the other based on DVS‐BCB adhesive wafer bonding. The realization of micro‐disk lasers, Fabry‐Perot lasers, DFB lasers, DBR lasers and mode‐locked lasers on the III‐V/SOI material platform is discussed.
Experimental verification of diverging mechanisms in the binding of ether, thioether, and sulfone ligands to a dirhodium tetracarboxylate
Authors: Mattiza Jens T. , Meyer Vera J. , Duddeck Helmut
Published: January 2010

Complexation of the oxygen atom in 2‐butylphenylethers and sulfur in 2‐butylphenylthioethers to a rhodium atom in dirhodium tetracarboxylate Rh(II)2[(R)‐(+)‐MTPA]4 is compared. Oxygen atoms complex via electrostatic attraction exclusively leading to an increase in α effects on C‐2 complexation shifts in the sequence OCH3 > F > Br > NO2. However, that trend is opposite in thioethers. This can be rationalized by an additional highest occupied molecular orbital (HOMO)–LUMO interaction and the response of this interaction upon complex formation shifts. Thereby, an experimental evidence was found for the existence of the HOMO–LUMO binding mechanism which has been proposed previously based on theoretical considerations and indirect spectroscopic evidence. Sulfones hardly bind to Rh(II)2[(R)‐(+)‐MTPA]4. Diastereomeric dispersion effects at 13C and 1H signals can be observed for all compounds indicating that enantiodifferentiation is easy in all classes of functionalities. Copyright © 2010 John Wiley & Sons, Ltd.
Feasibility and tolerability of bevacizumab in children with primary CNS tumors
Authors: Reismüller Bettina , Azizi Amedeo A. , Peyrl Andreas , Heinrich Monika , Gruber‐Olipitz Mariella , Luckner Doris , Rothschild Klara Vergesslich , Slavc Irene
Published: January 2010

Background

Bevacizumab, an antibody to the vascular endothelial growth factor, has demonstrated anti‐cancer activity in a number of solid tumors. Fear of intratumoral hemorrhage, however, has slowed its introduction into the treatment of central nervous system (CNS) tumors. Currently, only a small number of children with gliomas received bevacizumab.

Methods

We retrospectively analyzed 30 patients who received bevacizumab between January 2007 and August 2009. The median age at start of bevacizumab treatment was 9.9 years (range: 1.5–18). Most patients had recurrent/progressive disease, 25 high‐grade and 5 low‐grade tumors. The median dose of bevacizumab was 9.5 mg/kg (range 5–15 mg/kg) every 2–3 weeks. In total, 478 courses were administered (median/patient 15.9, range: 2–52). The median duration of bevacizumab treatment was 10.0 months (range: 1.6–30.4). Twenty‐nine of 30 patients received additional therapy concomitant to bevacizumab.

Results

No bevacizumab related intratumoral hemorrhage occurred in any of our 30 patients. Grade III hypertension was seen in two patients. One patient developed nephrotic syndrome requiring cessation of treatment. Grade III and I proteinuria were observed in one and five patients, respectively. New onset lymphopenia occurred in 12/30 and new onset hypothyroidism in 7/30 patients. Impaired wound healing was manageable. No immediate bevacizumab‐related cardiotoxicity was observed as evidenced by echocardiography.

Conclusions

Bevacizumab appears to be safe for children with primary CNS tumors. Adverse effects did occur but were manageable. No treatment‐related death occurred. Long‐term monitoring is advisable to detect lymphopenia and hypothyroidism. Hypertension occurred less frequently than in adult patients. Further prospective studies including more patients are warranted. Pediatr Blood Cancer 2010;54:681–686. © 2010 Wiley‐Liss, Inc.
Mcl‐1–Bim complexes accommodate surprising point mutations via minor structural changes
Authors: Fire Emiko , Gullá Stefano V. , Grant Robert A. , Keating Amy E.
Published: January 2010

Mcl‐1 is an antiapoptotic Bcl‐2‐family protein that protects cells against death. Structures of Mcl‐1, and of other anti‐apoptotic Bcl‐2 proteins, reveal a surface groove into which the α‐helical BH3 regions of certain proapoptotic proteins can bind. Despite high overall structural conservation, differences in this groove afford binding specificity that is important for the mechanism of Bcl‐2 family function. We report the crystal structure of human Mcl‐1 bound to a BH3 peptide derived from human Bim and the structures for three complexes that accommodate large physicochemical changes at conserved Bim sites. The mutations had surprisingly modest effects on complex stability, and the structures show that Mcl‐1 can undergo small changes to accommodate the mutant ligands. For example, a shift in a leucine side chain fills a hole left by an isoleucine‐to‐alanine mutation at the first hydrophobic buried position of Bim BH3. Larger changes are also observed, with shifting of helix α3 accommodating an isoleucine‐to‐tyrosine mutation at this same position. We surveyed the variation in available Mcl‐1 and Bcl‐xL structures and observed moderate flexibility that is likely critical for facilitating interactions of diverse BH3‐only proteins with Mcl‐1. With the antiapoptotic Bcl‐2 family members attracting significant attention as therapeutic targets, these structures contribute to our growing understanding of how specificity is achieved and can help to guide the design of novel inhibitors that target Mcl‐1.
Protein structure prediction enhanced with evolutionary diversity: SPEED
Authors: DeBartolo Joe , Hocky Glen , Wilde Michael , Xu Jinbo , Freed Karl F. , Sosnick Tobin R.
Published: January 2010

For naturally occurring proteins, similar sequence implies similar structure. Consequently, multiple sequence alignments (MSAs) often are used in template‐based modeling of protein structure and have been incorporated into fragment‐based assembly methods. Our previous homology‐free structure prediction study introduced an algorithm that mimics the folding pathway by coupling the formation of secondary and tertiary structure. Moves in the Monte Carlo procedure involve only a change in a single pair of ϕ,ψ backbone dihedral angles that are obtained from a Protein Data Bank‐based distribution appropriate for each amino acid, conditional on the type and conformation of the flanking residues. We improve this method by using MSAs to enrich the sampling distribution, but in a manner that does not require structural knowledge of any protein sequence (i.e., not homologous fragment insertion). In combination with other tools, including clustering and refinement, the accuracies of the predicted secondary and tertiary structures are substantially improved and a global and position‐resolved measure of confidence is introduced for the accuracy of the predictions. Performance of the method in the Critical Assessment of Structure Prediction (CASP8) is discussed.
Reversibly bound chloride in the atrial natriuretic peptide receptor hormone‐binding domain: Possible allosteric regulation and a conserved structural motif for the chloride‐binding site
Authors: Ogawa Haruo , Qiu Yue , Philo John S. , Arakawa Tsutomu , Ogata Craig M. , Misono Kunio S.
Published: January 2010

The binding of atrial natriuretic peptide (ANP) to its receptor requires chloride, and it is chloride concentration dependent. The extracellular domain (ECD) of the ANP receptor (ANPR) contains a chloride near the ANP‐binding site, suggesting a possible regulatory role. The bound chloride, however, is completely buried in the polypeptide fold, and its functional role has remained unclear. Here, we have confirmed that chloride is necessary for ANP binding to the recombinant ECD or the full‐length ANPR expressed in CHO cells. ECD without chloride (ECD(−)) did not bind ANP. Its binding activity was fully restored by bromide or chloride addition. A new X‐ray structure of the bromide‐bound ECD is essentially identical to that of the chloride‐bound ECD. Furthermore, bromide atoms are localized at the same positions as chloride atoms both in the apo and in the ANP‐bound structures, indicating exchangeable and reversible halide binding. Far‐UV CD and thermal unfolding data show that ECD(−) largely retains the native structure. Sedimentation equilibrium in the absence of chloride shows that ECD(−) forms a strongly associated dimer, possibly preventing the structural rearrangement of the two monomers that is necessary for ANP binding. The primary and tertiary structures of the chloride‐binding site in ANPR are highly conserved among receptor‐guanylate cyclases and metabotropic glutamate receptors. The chloride‐dependent ANP binding, reversible chloride binding, and the highly conserved chloride‐binding site motif suggest a regulatory role for the receptor bound chloride. Chloride‐dependent regulation of ANPR may operate in the kidney, modulating ANP‐induced natriuresis.
Packet‐based algorithms for stepping‐stone detection with chaff perturbation
Authors: Wu Han‐Ching , Huang Shou‐Hsuan Stephen
Published: January 2010

Network intruders usually launch attacks indirectly by constructing a long connection via intermediary hosts, called stepping‐stones, to hide their identities. In order to detect this type of malicious behavior, it is necessary to identify whether a host has been used as a stepping‐stone. More sophisticated intruders even add extra superfluous packets, called chaff packets, to evade detection. In this paper, we introduce the packet‐based approach to detect stepping‐stones with chaff perturbation based on the range of a random walk model. Two algorithms, size‐fluctuation and transformation, are proposed for this approach to distinguish the stepping‐stone connections from the normal connections. The results show that both algorithms are able to identify the stepping‐stone connections effectively under a larger number of chaff perturbation and with fewer monitored packets than the existing methods. Copyright © 2010 John Wiley & Sons, Ltd.
A comprehensive investigation of secure location estimation techniques for WSN applications
Authors: Arisar S. H. , Kemp A. H.
Published: January 2010

Globally, a number of schemes have been proposed to address the challenging task of providing secure location estimation of sensor nodes (SNs) in a wireless sensor network (WSN) under adversarial conditions. The aim of this paper is to highlight this research work by analyzing the proposed solutions, highlighting their strengths and weaknesses. This work also provides an insight into the steps leading to the design of a novel optimized secure location estimation scheme. Copyright © 2010 John Wiley & Sons, Ltd.
Better security enforcement in trusted computing enabled heterogeneous wireless sensor networks
Authors: Yang Yanjiang , Zhou Jianying , Deng Robert H. , Bao Feng
Published: January 2010

A wireless sensor network (WSN) is anad hocwireless network composed of a large number of small sensor nodes. Sensor nodes are usually severely resource limited and power constrained, and as such security enforcement in WSNs is a challenging task. To facilitate security enforcement, we propose a heterogeneous architecture for WSNs, where a WSN is partitioned into clusters, each having a high‐end cluster head. The cluster heads are further equipped with trusted computing technology (TC), such that they act as online trusted parties, thereby expected to help enforce security in a more effective manner. To show this, we discuss various examples on both content security and context security. Copyright © 2010 John Wiley & Sons, Ltd.
Copper surface enrichment of AgCu alloys
Authors: Lejček Pavel , Kovač Janez , Vaníčková Jaroslava , Děd Jiří , Samardžija Zoran , Zalar Anton
Published: January 2010

We summarise the X‐ray electron spectroscopy (XPS) study of changing surface composition of polycrystalline Ag–2.2 mass% Cu and Ag–5.1 mass% Cu alloys during in situ annealing at chosen temperatures ranging from 300 to 600 °C. The results show obvious surface enrichment by copper, which is different for individual alloys. The contradiction of this result to general knowledge on preferential silver segregation can be explained on basis of attractive interaction of copper with oxygen and of accelerated diffusion of copper to the surface resulting in final copper surface enrichment. Copyright © 2010 John Wiley & Sons, Ltd.
Characterization of a very thin overoxidized polypyrrole membrane: application to H2O2 determination
Authors: Debiemme‐Chouvy Catherine , Gallois Maud
Published: January 2010

In the design of amperometric biosensor based on the electrochemical detection of enzymatically generated H2O2, an inert membrane is often present on the electrode in order to separate it from the solution to prevent interferences. The inert membrane could be an overoxidized polypyrrole film. Generally, the overoxidized polypyrrole films are obtained in two steps, the first one being the electrosynthesis of the polypyrrole film and the second one its overoxidation in an indifferent electrolyte. In this article, a new electrochemical one‐step process allowing the formation of a very thin overoxidized polypyrrole film is used. This film is characterized by SEM, XPS and cyclic voltammetry in the presence of monoelectronic reversible redox couples. Actually, the film is an electrical insulating compact layer about 10‐nm thick and pin hole free. This overoxidized polypyrrole membrane was tested on one hand for the rejection of anions and large molecules such as Fe(CN)63/4− and Ru(NH3)62/3+, respectively, and on the other hand, for the determination of hydrogen peroxide. The results show a very good efficiency of the membrane for the rejection of the redox species tested. Finally, it is shown that the membrane/Pt electrode allows quantitative electrooxidation of H2O2. Indeed, using this electrode, under potentiostatic condition, a linear response of the anodic current in function of the H2O2 electrolyte concentration was found. Copyright © 2010 John Wiley & Sons, Ltd.
Stress and quality of sleep among individuals diagnosed with diabetes
Authors: Perfect Michelle M. , Elkins Gary R. , Lyle‐Lahroud Teresa , Posey Jennie R.
Published: January 2010

Several studies have suggested that stress and sleep may be related to diabetic disease progression. Cortisol is one physiological indicator of stress that has been well validated in previous research. The primary objectives of the present study were (1) to examine the experiences of stress among patients diagnosed with diabetes and (2) to evaluate the quality of sleep among these participants. Participants (mean age = 34.99 years) were 20 adolescents and adults with Diabetes Mellitus; 13 had Type 1 and 17 were female. Primary measures included actigraphy, the Pittsburgh Sleep Quality Index (PSQI), salivary cortisol and the Perceived Stress Scale (PSS). Participants reported a moderate amount of stress (mean PSS scores = 20.2), slept an average of 6.51 h and exhibited at least one clinical indicator of sleep disturbance. Objectively measured total sleep time was associated with awakening cortisol (r = 0.62, p = 0.004) and PSQI Global scores (r = ‐0.51, p = 0.021). Awakening cortisol and PSS scores were not associated with PSQI Global scores, but were related to specific self‐reported sleep disturbances. Given the interacting physiological pathways of stress and sleep, both of which were evident in this small sample, these variables warrant further study. Copyright © 2009 John Wiley & Sons, Ltd.