bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and properties of homogeneously dispersed polyamide 6/MWNTs nanocomposites via simultaneous in situ anionic ring‐opening polymerization and compatibilization
Authors: Yan Dongguang , Yang Guisheng
Published: March 2009

Toluene 2, 4‐diisocyanate (TDI) functionalized multiwalled carbon nanotubes (MWNTs‐NCO) were used to prepare monomer casting polyamide 6 (MCPA6)/MWNTs nanocomposites via in situ anionic ring‐opening polymerization (AROP). Isocyanate groups of MWNTs‐NCO could serve as AROP activators of ϵ‐caprolactam (CL) in the in situ polymerization. Fourier transform infrared (FTIR) showed that a graft copolymer of PA6 and MWNTs was formed in the in situ polymerization. MWNTs‐PA6 covalent bonds of the graft copolymer constituted a strong type of interfacial interaction in the nanocomposites and increased the compatibility of MWNTs and MCPA6 matrix. The nanocomposites were characterized for the morphology, mechanical, crystallization, and thermal properties through field emission transmission electron microscopy (FETEM), tensile testing, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA). FETEM analysis showed that MWNTs were homogeneously dispersed in MCPA6 matrix. The initial tensile strengths and tensile modulus of the nanocomposite with 1.5 wt % loading of MWNTs were enhanced by about 16 and 13%, respectively, compared with the corresponding values for neat MCPA6. DSC analysis indicated that the crystallization temperature of the nanocomposites was increased by 8°C by adding 1.5 wt % MWNTs compared with pure MCPA6. Besides, it was found that the thermal stability of MCPA6 was improved by the addition of the MWNTs. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Relationship of polymorphic crystalline phase texture to strain recovery and stiffness of a propylene‐based elastomer
Authors: Dias P. , Kazmierczak T. , Chang A. , Ansems P. , Van Dun J. , Hiltner A. , Baer E.
Published: March 2009

A stretching process to enhance the stiffness of an elastomeric propylene‐ethylene copolymer through orientation was examined. The tensile extension was performed at various temperatures within the unusually broad melting range of the copolymer. Stretching transformed the unmelted lamellar crystals into shish‐kebab fibers that acted as a scaffold for an elastomeric matrix of entangled, amorphous chains. Density measurements indicated that the process did not significantly affect the amount of crystallinity, which was about 23%. If the specimen was recrystallized by cooling after it recovered from the stretched state, the amount of orientation decreased with increasing stretching temperature. However, if recrystallization occurred in the stretched state, it led to the formation of a second crystalline network that prevented contraction of the oriented crystalline structure during strain recovery. It was suggested that the second network was anchored by α′‐PP daughter lamellae that crystallized epitaxially on the α‐PP mother crystals of the extended fibrils. Although the manner in which the films were stretched and recrystallized strongly affected the modulus, good elasticity of the stretched films revealed the persistence of an elastomeric network. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A strategy‐based process for implementing knowledge management: An integrative view and empirical study
Authors: Wu Ing‐Long , Lin Han‐Chang
Published: March 2009

Knowledge resource is unique and valuable for a link to competitive advantage based on the knowledge‐based perspective. Effective knowledge management is the major concern of contemporary business managers. The key determinant of effective knowledge management is the firm's competitive strategy. The link between business strategy and knowledge management, while often discussed, has been widely ignored in practice. Moreover, while knowledge management is complex in nature, it is difficult to directly translate a firm's competitive strategy into the specific knowledge management activities. This requires first defining knowledge strategy to guide further information technology (IT)‐supported implementation approaches. Finally, the ultimate goal of knowledge management lies in the realization of firm performance. Previous studies have just discussed partial relationship among these relevant knowledge concepts rather than in an integrative manner. Thus, this research proposes a complete process‐based model with four components: competitive strategy, knowledge strategy, implementation approach, and firm performance. Empirical results have shown positive relationships between any two consecutive components and useful insight for knowledge implementation practice.
Commonality of Web site visiting among countries
Authors: Huang Chun‐Yao , Chang Shin‐Shin
Published: March 2009

Although the role the Internet plays in globalization has been widely discussed, relatively little is known about the extent to which users in different countries visit the same Web sites. Surprisingly, no prior research in the literature has empirically addressed this topic in a systematic way. Based on the theory of life in the round and related concepts of information behavior, this article reports an attempt to fill the gap by looking at how cultural, geodemographical, and economic factors underpin the extent which people from different countries visit the same Web sites. A commonality index to measure the commonality of Web site visiting for the macrolevel, cross‐country study is proposed for a large‐scale empirical study using online panel data that cover 101 countries. Results from the analyses indicate that as cyberspace is obviously fractured, Internet users in countries that share a common language, religion, and social norms, that have a similar level of economic development, and that are physically nearer to one another are more likely to visit the same Web sites. The relationship between individual‐level information behavior and macrolevel Internet traffic metrics is established; the former helps explain the latter whereas the latter enriches the former.
Are you an invited speaker? A bibliometric analysis of elite groups for scholarly events in bioinformatics
Authors: Jeong Senator , Lee Sungin , Kim Hong‐Gee
Published: March 2009

Participating in scholarly events (e.g., conferences, workshops, etc.) as an elite‐group member such as an organizing committee chair or member, program committee chair or member, session chair, invited speaker, or award winner is beneficial to a researcher's career development. The objective of this study is to investigate whether elite‐group membership for scholarly events is representative of scholars' prominence, and which elite group is the most prestigious. We collected data about 15 global (excluding regional) bioinformatics scholarly events held in 2007. We sampled (via stratified random sampling) participants from elite groups in each event. Then, bibliometric indicators (total citations and h index) of seven elite groups and a non‐elite group, consisting of authors who submitted at least one paper to an event but were not included in any elite group, were observed using the Scopus Citation Tracker. The Kruskal–Wallis test was performed to examine the differences among the eight groups. Multiple comparison tests (Dwass, Steel, Critchlow–Fligner) were conducted as follow‐up procedures. The experimental results reveal that scholars in an elite group have better performance in bibliometric indicators than do others. Among the elite groups, the invited speaker group has statistically significantly the best performance while the other elite‐group types are not significantly distinguishable. From this analysis, we confirm that elite‐group membership in scholarly events, at least in the field of bioinformatics, can be utilized as an alternative marker for a scholar's prominence, with invited speaker being the most important prominence indicator among the elite groups.
Language and reading abilities of children with autism spectrum disorders and specific language impairment and their first‐degree relatives
Authors: Lindgren Kristen A. , Folstein Susan E. , Tomblin J. Bruce , Tager‐Flusberg Helen
Published: March 2009

Autism spectrum disorder (ASD) and specific language impairment (SLI) are developmental disorders exhibiting language deficits, but it is unclear whether they arise from similar etiologies. Language impairments have been described in family members of children with ASD and SLI, but few studies have quantified them. In this study, we examined IQ, language, and reading abilities of ASD and SLI children and their first‐degree relatives to address whether the language difficulties observed in some children with ASD are familial and to better understand the degree of overlap between these disorders and their broader phenotypes. Participants were 52 autistic children, 36 children with SLI, their siblings, and their parents. The ASD group was divided into those with (ALI, n=32) and without (ALN, n=20) language impairment. Relationships between ASD severity and language performance were also examined in the ASD probands. ALI and SLI probands performed similarly on most measures while ALN probands scored higher. ALN and ALI probands' language scores were not related to Autism Diagnostic Interview—Revised and Autism Diagnostic Observation Schedule algorithm scores. SLI relatives scored lowest on all measures, and while scores were not in the impaired range, relatives of ALI children scored lower than relatives of ALN children on some measures, though not those showing highest heritability in SLI. Given that ALI relatives performed better than SLI relatives across the language measures, the hypothesis that ALI and SLI families share similar genetic loading for language is not strongly supported.
Melatonin: Signaling mechanisms of a pleiotropic agent
Authors: Hardeland Rüdiger
Published: March 2009

Melatonin acts both as a hormone of the pineal gland and as a local regulator molecule in various tissues. Quantities of total tissue melatonin exceed those released from the pineal. With regard to this dual role, to the orchestrating, systemic action on various target tissues, melatonin is highly pleiotropic. Numerous secondary effects result from the control of the circadian pacemaker and, in seasonal breeders, of the hypothalamic/pituitary hormonal axes. In mammals, various binding sites for melatonin have been identified, the membrane receptors MT1 and MT2, which are of utmost chronobiological importance, ROR and RZR isoforms as nuclear receptors from the retinoic acid receptor superfamily, quinone reductase 2, calmodulin, calreticulin, and mitochondrial binding sites. The G protein‐coupled receptors (GPCRs) MT1 and MT2 are capable of parallel or alternate signaling via different Gα subforms, in particular, Gαi2/3 and Gαq, and via Gβγ, as well. Multiple signaling can lead to the activation of different cascades and/or ion channels. Melatonin frequently decreases cAMP, but also activates phospholipase C and protein kinase C, acts via the MAP kinase and PI3 kinase/Akt pathways, modulates large conductance Ca2+‐activated K+ and voltage‐gated Ca2+ channels. MT1 and MT2 can form homo and heterodimers, and MT1 interacts with other proteins in the plasma membrane, such as an orphan GPCR, GPR50, and the PDZ domain scaffolding protein MUPP1, effects which negatively or positively influence signaling capacity. Cross‐talks between different signaling pathways, including influences of the membrane receptors on nuclear binding sites, are discussed. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
IL‐25: A key requirement for the regulation of type‐2 immunity
Authors: Barlow Jillian L. , McKenzie Andrew N. J.
Published: March 2009

It has been well‐established that type‐2 immunity, characterized by eosinophilia, goblet cell hyperplasia, mucus production, and B cell class switching to IgE, is highly dependent on the production of the type‐2 cytokines, interleukin (IL)‐4, IL‐5, IL‐9, and IL‐13, by T helper 2 (Th2) cells. However, it is less clear how the type‐2 cytokine effector response is induced and in addition what innate cell type produces the initiating factor. Recent reports highlight IL‐25 as a type‐2 inducing factor, with IL‐25 administration resulting in severe gut and lung type‐2 pathologies. The expression of IL‐25 is also necessary for initiation of a robust type‐2 response both at the genesis of the response, as with helminth infection, and during the response, as has been shown in experimental allergic asthma. It is also apparent that, as well as directly controlling type‐2 immunity via IL‐4, IL‐5, and IL‐13, IL‐25 may also interact with other cytokines and their receptors, such as IL‐17A and the IL‐17RA receptor. Here, we review the role of IL‐25 as an important factor in controlling the initiation and severity of the type‐2 response, and as an alternative therapeutic target to the type‐2 cytokine family, for the treatment of allergic asthma. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
Influence of alternating L‐/D‐amino acid chiralities and disulfide bond geometry on the capacity of cysteine‐containing reversible cyclic peptides to disperse carbon nanotubes
Authors: Becraft Eric J. , Klimenko Anton S. , Dieckmann Gregg R.
Published: March 2009

Although single‐walled carbon nanotubes (SWNTs) have exciting properties and potential applications, their hydrophobic nature makes them difficult to purify and manipulate. To fully realize the potential of SWNTs, strategies for the effective dispersion, separation, and organization of these materials must be devised. In this article, work involving the recent design and characterization of reversible cyclic peptides (RCPs) and RCP/SWNT composites will be described. The peptides in this work contain alternating L‐ and D‐amino acid sequences, as well as N‐ and C‐terminal cysteine residues (RCP‐Cys) that allow for their covalent closure around the circumference of individual SWNTs. When RCPs are oxidized in the presence of SWNTs, dispersions are produced that are stable against dilution by dialysis without the formation of aggregates. The reported studies using Raman spectroscopy and UV/Vis/NIR were focused on answering the questions (1) does the chirality of the disulfide bond impact the capacity of the RCP‐Cys to disperse SWNTs, and (2) is the alternating chirality of the amino acids in the RCP‐Cys peptides important for SWNT dispersion. It was found that though Cys‐containing RCPs are indeed able to disperse SWNTs, the chirality of the Cys residues on the N‐ and C‐ termini does not have a significant influence on the dispersed SWNT population. However, there is a large decrease in the dispersability by RCP‐Cys when the alternating L/D‐chiral pattern of amino acids is replaced with all L‐amino acids. © 2009 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 92: 212–221, 2009.

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Prognostic value of subclassification of T2 tumours in patients with gastric cancer
Authors: Nitti D , Marchet A , Mocellin S , Rossi G M , Ambrosi A , Mencarelli R
Published: March 2009

Background

This study was designed to evaluate the prognostic value of tumour stage T2 subcategorization (T2a and T2b) in patients with gastric carcinoma.

Methods

Clinicopathological details of a prospective series of patients who had radical resection of gastric adenocarcinoma in a single institution were analysed. Univariable and multivariable survival analyses were performed with the log rank test and Cox's model respectively.

Results

Of 373 evaluable patients, 49 (13·1 per cent) had a T2a and 143 (38·3 per cent) a T2b tumour. At a median follow-up of 35·5 months, the 5-year overall survival rate was 73 and 31·1 per cent for patients with T2a and T2b lesions respectively (P < 0·001). On multivariable analysis, T stage remained an independent prognostic factor. Compared with T1a, the mortality risk for patients with T1b (hazard ratio (HR) 1·00; P = 0·992) and T2a (HR 0·97; P = 0·916) tumours was similar; by contrast, the risk of death associated with T2b (HR 1·81; P = 0·031) and T3 (HR 1·89; P = 0·038) lesions was significantly greater than for T1a tumours.

Conclusion

Subclassification of T2 tumours should be undertaken routinely in order to stratify patients with gastric cancer more accurately in terms of their mortality risk.
Validation of a nomogram for predicting survival after resection for adenocarcinoma of the pancreas
Authors: de Castro S M M , Biere S S A Y , Lagarde S M , Busch O R C , van Gulik T M , Gouma D J
Published: March 2009

Background

Nomograms are statistical tools providing the overall probability of a specific outcome; they have shown better individual discrimination than the tumour node metastasis staging system in several cancers. The pancreatic nomogram, originally developed in the Memorial Sloan–Kettering Cancer Center (MSKCC) in the USA, combines clinicopathological and operative data to predict disease-specific survival at 1, 2 and 3 years from initial resection.

Methods

An external patient cohort from a retrospective pancreatic adenocarcinoma database at the Academic Medical Centre in Amsterdam was used to test the validity of the pancreatic adenocarcinoma nomogram. The cohort included 263 consecutive patients who had surgery between January 1985 and December 2004.

Results

Data for all the necessary variables were available for 256 patients (97·3 per cent). At the last follow-up, 35 patients were alive, with a median follow-up of 27 (range 3–114) months. The 1-, 2- and 3-year disease-specific survival rates were 60·8, 30·4 and 16·0 per cent respectively. The nomogram concordance index was 0·61. The calibration analysis of the model showed that the predicted survival did not significantly deviate from the actual survival.

Conclusion

The MSKCC pancreatic cancer nomogram provided an accurate survival prediction. It may aid in counselling patients and in stratification of patients for clinical trials.
Prognosis of synchronous bilateral breast cancer
Authors: Irvine T , Allen D S , Gillett C , Hamed H , Fentiman I S
Published: March 2009

Background

The prognosis of patients with synchronous bilateral breast cancer (SBBC) is usually based on the tumour with the worst pathological features. There is little evidence in the literature for this assumption, potentially impairing reasoned decisions on optimal adjuvant therapy.

Methods

This was a case–control study in which 68 women with SBBC were matched with 128 women with unilateral breast cancer. Both the GuysRisk prognostic model and the Nottingham Prognostic Index were used to determine the bilateral tumour with the poorer prognosis. Controls were matched for age, menopausal status, date of diagnosis, histological type and grade, and oestrogen receptor and axillary node status.

Results

Both prognostic models indicated the same side tumour with the worst prognosis. Kaplan–Meier survival curves for both disease-free and overall survival showed no significant difference in outcome between the two groups.

Conclusion

Prognosis was determined by the tumour with the worst prognosis, with no additional worsening of outcome incurred from the second tumour.
Hidradenitis suppurativa
Authors: Buimer M G , Wobbes T , Klinkenbijl J H G
Published: March 2009

Background

Hidradenitis suppurativa is a chronic, recurrent, suppurative cutaneous disease. Despite its incidence, optimal medical or surgical treatment remains unclear. This review describes the disease, ranging from pathogenesis to treatment and prognosis.

Methods

Articles were sourced from PubMed and Medline, using the MeSH terms ‘hidradenitis suppurativa’ and ‘acne inversa’. Selection of articles was based on peer review, journal, relevance and English language.

Results and conclusion

On the basis of histological findings, the disease is now considered inflammatory and originating from the hair follicle; therefore, the term ‘acne inversa’ is favoured by some experts. The exact aetiology remains obscure but smoking seems to be a major triggering factor. Treatment should be individualized according to the site and extent of the disease. Absolute cessation of smoking is essential in the treatment of hidradenitis. Management with antibiotics or other medications may relieve early symptoms, but radical surgery may be necessary for control and to prevent recurrence.
Surgical training and working time restriction
Authors: Glomsaker T B , Søreide K
Published: March 2009

Team–patient, not doctor–patient, relationship
Mechanistic Study of Carbon Oxidation with NO2 and O2 in the Presence of a Ru/Na‐Y Catalyst
Authors: Jeguirim M. , Tschamber V. , Villani K. , Brilhac J. F. , Martens J. A.
Published: March 2009

The oxidation of model soot by NO2 and O2 in the presence of a Ru/Na‐Y catalyst under conditions close to automotive exhaust gas after‐treatment systems is investigated. Isothermal oxidation experiments of a physical mixture of carbon black and catalyst were performed in a temperature range of 300–400 °C. A remarkable increase of the oxidation rate by NO2 and O2 in the presence of the Ru/Na‐Y catalyst was observed. An overall mechanism involving oxygen transfer from the Ru catalyst to the carbon surface leading to an increase of C(O) complexes is proposed. These C(O) complexes are destabilized in the presence of NO2 increasing the carbon oxidation rate.
Density Functional Studies on Isomerization of Prostaglandin H2to Prostacyclin Catalyzed by Cytochrome P450
Authors: Yanai Tetsuya K. , Mori Seiji
Published: March 2009

At the double: DFT studies on the biosynthesis of prostacyclin (PGI2, see scheme) from prostaglandin H2(PGH2) show two reaction mechanisms through two different oxidation states, an FeIV–porphyrin intermediate and an FeIII–porphyrin π‐cation radical, followed by a proton‐coupled electron‐transfer process.

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Reaction mechanisms for the isomerization of prostaglandin H2to prostacyclin catalyzed by cytochrome P450 are investigated by the unrestricted Becke's three‐parameter plus Lee–Yang–Parr density functional level of theory. The results show that the homolytic OO bond cleavage of endoperoxide in prostaglandin H2is the rate‐limiting step and that the isomerization proceeds through proton‐coupled electron transfer. We located two reaction pathways through an FeIV–porphyrin intermediate and an FeIII–porphyrin π‐cation radical intermediate.
An All‐Photonic Molecular Keypad Lock
Authors: Andréasson Joakim , Straight Stephen D. , Moore Thomas A. , Moore Ana L. , Gust Devens
Published: March 2009

Off and on: A molecular triad, consisting of a porphyrin linked to two different, independently addressable photochromic moieties, functions as a molecular keypad lock with all‐photonic inputs and output. The porphyrin correlates the responses of the two inputs to light of different wavelengths and provides an appropriate output as fluorescence, which results only when one of eight possible input combinations has been applied (see figure).

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Untersuchungen zur Fluoreszenz von Lactat bei Raumtemperatur und tiefen Temperaturen
Authors: Wimmer C. , Arnold T. , Großmann K.
Published: March 2009

Die Fluoreszenzeigenschaften einer 0,1 M Lactatlösung wurden bei Raumtemperatur und im gefrorenen Zustand bei 200, 100, und 10 K bei einer Anregungswellenlänge von 266 nm durch Kopplung der zeitaufgelösten Laser‐induzierten Fluoreszenzspektroskopie (TRLFS) mit einem Kryostatensystem untersucht. Bei Raumtemperatur konnte keine Fluoreszenz nachgewiesen werde. Allerdings war es mit abnehmender Temperatur möglich, eine stark zunehmende Fluoreszenzintensität und ‐lebensdauer zu detektiert. Es ließ sich ein Intensitätsmaximum bei 472 ± 2 nm und bei 10 K eine Lebensdauer von 6737,5 ± 1,6 ns ermitteln.
Lösungsmitteleinfluss Ionischer Flüssigkeiten bei der radikalischen Polymerisation
Authors: Schmidt‐Naake G. , Schmalfuß A. , Woecht I. , Glück T.
Published: March 2009

Bei der radikalischen Polymerisation von polaren, in ionischen Flüssigkeiten (ILs) löslichen Monomeren wird ein außerordentlich großer Lösungsmitteleffekt beobachtet. Der Lösungsmitteleinfluss der ILs verursacht eine erhebliche Erhöhung der Polymerisationsgeschwindigkeit und auffallend hohe, meist breit verteilte Molmassen. Sowohl die experimentell ermittelten sehr großen Wachstumskonstanten kp als auch die Reduzierung ihrer Aktivierungsenergie sind durch Wasserstoffbrückenbindungen der Monomere und wachsende Radikalketten mit den Kationen sowie den Anionen der IL erklärbar. Die hohe Viskosität der IL sowie die zunehmende Viskosität im Reaktionsverlauf sind für die hohen Molmassen und meist beträchtlichen Polydispersitäten verantwortlich. In dieser Arbeit wird die gezielte Veränderung der Polymerisationskonstanten kp und kt durch den Einsatz von Mikrowellenreaktoren, IL‐Lösungsmittelgemischen und erhöhten Reaktionstemperaturen untersucht.
Numerical framework for patient‐specific computational modelling of vascular tissue
Authors: Alastrué V. , Garía A. , Peña E. , Rodríguez J. F. , Martínez M. A. , Doblaré M.
Published: March 2009

Accurate determination of the biomechanical implications of vascular surgeries or pathologies on patients requires developing patient‐specific models of the organ or vessel under consideration. In this regard, combining the development of advanced constitutive laws that mimic the behaviour of the vascular tissue with advanced computer analysis and medical imaging techniques provides a powerful tool for modelling vascular tissues on a patient‐specific basis. A framework for developing patient‐specific models of blood vessel geometries obtained from medical imaging techniques is presented. The multiplicative decomposition of the deformation gradient tensor is intensively combined with the finite element method in order to account for the residual stress present on those geometries. In addition, an algorithm to compensate the mismatching effect of the load on the medical images is also discussed. Hence, a residually stressed and geometrically consistent model of the patient is obtained. The general framework is demonstrated in a realistic geometry of a carotid bifurcation. The example presented in this work shows that the incorporation of the residual stress dramatically affects the circumferential stress field, homogenizing the distribution and reducing the stress gradient. It also demonstrates that not accounting for the residual stress on a patient‐specific geometry can lead to a completely different deformed configurations. Copyright © 2009 John Wiley & Sons, Ltd.
Infrared Absorption Spectra of t‐HNOH Radicals Generated on VUV Irradiation of NO in Solid Hydrogen
Authors: Wu Yu‐Jong , Lin Meng‐Yeh , Hsu Sheng‐Chuan , Cheng Bing‐Ming
Published: March 2009

Photoproduct signature: Irradiation of solid hydrogen near 3 K containing NO with vacuum‐UV light from synchrotron radiation yields new infrared absorption lines at 1241.7, 1063.6 and 726.2 cm−1 (see figure). These new lines are assigned to vibrational modes of t‐HNOH. This photoproduct is formed from electronically excited NO reacting with neighboring hydrogen in the solid sample.

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Irradiation of solid H2 near 3 K containing NO with vacuum‐ultraviolet light from a synchrotron yields new infrared absorption lines at 1241.7, 1063.6 and 726.2 cm−1. The structures of four possible structural isomers: H2NO, t‐HNOH, c‐HNOH and NOH2, their vibrational wavenumbers, IR intensities and D‐isotopic shifts are calculated with density‐functional theory according to B3LYP and PW91PW91/aug‐cc‐pVTZ methods. Based on the results of those calculations and of experiments with deuterium labeling, we assign the new lines to ν4 (cis bending), ν5 (NO stretching) and ν6 (out‐of‐plane deformation) modes, respectively, of t‐HNOH. This photoproduct is formed through reaction of electronically excited NO with neighboring H2 in the solid sample.
Optical Second Harmonic Generation Chiral Spectroscopy
Authors: Foerier Stijn , Kolmychek Irina A. , Aktsipetrov Oleg A. , Verbiest Thierry , Valev Ventsislav K.
Published: March 2009

Chiral spectroscopic study: The intensities of second harmonic generation chiral spectroscopy are obtained from the dispersion of the nonlinear optical susceptibility components, as a function of wavelength for helicenbisquinone thin films (see figure). A single formalism fits all the data simultaneously, and the findings constitute an important milestone towards the development of a new experimental technique.

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Properties of Amorphous Hydrogenated Silicon Carbide (a‐SiC:H) Films Formed by Remote Hydrogen Microwave Plasma CVD From a Triethylsilane Precursor: Part 2
Authors: Walkiewicz‐Pietrzykowska Agnieszka , Wrobel Aleksander M. , Glebocki Bartosz
Published: March 2009

The surface morphology and physical (density), optical (refractive index), and mechanical (hardness, elasticity) properties of amorphous hydrogenated silicon carbide (a‐SiC:H) films produced by remote microwave hydrogen plasma (RHP)CVD from a triethylsilane precursor are investigated. The effect of substrate temperature (varied in the range Ts = 30–400 °C) on the properties of a‐SiC:H films is reported. In view of the atomic force microscopy (AFM) examination the films were found to be morphologically homogeneous materials exhibiting small surface roughness which varies with Ts in a narrow range of values (1.0–1.5 nm). The relationships between the film compositional parameter, expressed by the atomic concentration ratio Si/C, and structural parameter described by the relative integrated intensities of the absorption IR band from the SiC bonds (controlled by substrate temperature) are examined. On the basis of the results of these examinations, reasonable compositional and structural dependencies of film properties are determined. The properties of investigated a‐SiC:H films are compared with those reported in the literature for films produced from various organosilicon precursors by different CVD techniques. Due to their good mechanical properties a‐SiC:H films produced in a high substrate temperature regime (Ts = 300–400 °C) seem to be useful as protective coatings improving the surface mechanics of various engineering materials.
Parathyroid fine‐needle aspiration cytology in the evaluation of parathyroid adenoma: Cytologic findings from 53 patients
Authors: Agarwal Archana M. , Bentz Joel S. , Hungerford Ryan , Abraham Dev
Published: March 2009

This study was designed to assess the utility of fine‐needle aspiration cytology (FNAC) in the preoperative localization of parathyroid adenoma (PA). Fifty‐seven samples from fifty‐three cases of PA (four patients had bilateral disease) were obtained by ultrasound (US)‐guided fine‐needle aspiration. Parathyroid hormone (PTH) estimation was performed on the supernatant of the aspirated fluid on all cases. Subsequently, all of them underwent cytologic evaluation. The cytology slides were evaluated using the following criteria: Cellularity, architectural patterns, bare nuclei in the background, nuclear morphology, and background features (colloid‐like material or macrophages). Parathyroid cells were seen in 23 samples (40.4%). The cellularity of the smears was insufficient for interpretation in 16 samples (28.1%); and thyroid follicles and colloid were seen in 18 samples (31.5%). Majority of the samples with parathyroid cells showed moderate cellularity with monomorphous round to slightly oval cells predominantly arranged in loose two‐dimensional clusters with occasional papillary fragments. Majority of them exhibited a stippled nuclear chromatin. No significant pleomorphism, mitotic activity, or prominent nucleoli were observed. Most samples showed bare nuclei in the background. In conclusion, US‐guided FNAC has its limitations because of low sensitivity in primary localization of the parathyroid adenoma in cases of primary hyperparathyroidism and is not a useful mode of investigation in cases of PA. Diagn. Cytopathol. 2009. © 2009 Wiley‐Liss, Inc.
T‐cell tolerance induced by repeated antigen stimulation: Selective loss of Foxp3− conventional CD4 T cells and induction of CD4 T‐cell anergy
Authors: Eroukhmanoff Lena , Oderup Cecilia , Ivars Fredrik
Published: March 2009

Repeated immunization of mice with bacterial superantigens induces extensive deletion and anergy of reactive CD4 T cells. Here we report that the in vitro proliferation anergy of CD4 T cells from TCR transgenic mice immunized three times with staphylococcal enterotoxin B (SEB) (3× SEB) is partially due to an increased frequency of Foxp3+ CD4 T cells. Importantly, reduced number of conventional CD25− Foxp3− cells, rather than conversion of such cells to Foxp3+ cells, was the cause of that increase and was also seen in mice repeatedly immunized with OVA (3× OVA) and OVA—peptide (OVAp) (3× OVAp). Cell‐transfer experiments revealed profound but transient anergy of CD4 T cells isolated from 3× OVAp and 3× SEB mice. However, the in vivo anergy was CD4 T‐cell autonomous and independent of Foxp3+ Treg. Finally, proliferation of transferred CD4 T cells was inhibited in repeatedly immunized mice but inhibition was lost when transfer was delayed, despite the maintenance of elevated frequency of Foxp3+ cells. These data provide important implications for Foxp3+ cell‐mediated tolerance in situations of repeated antigen exposure such as human persistent infections.
BM stromal cells ameliorate experimental autoimmune myasthenia gravis by altering the balance of Th cells through the secretion of IDO
Authors: Kong Qing‐fei , Sun Bo , Wang Guang‐you , Zhai Dong‐xu , Mu Li‐li , Wang Dan‐dan , Wang Jing‐hua , Li Rui , Li Hu‐lun
Published: March 2009

In addition to their capacity to differentiate, BM stromal cells (BMSC) have immunosuppressive qualities that make them strong candidates for use in cell therapy against human autoimmune diseases. We studied the immunoregulatory activities of BMSC on experimental autoimmune myasthenia gravis (EAMG) in vitro and in vivo. Intravenous administration of syngenic BMSC to EAMG‐model rats on the day of their second immunization was effective in ameliorating the pathological features of the disease. In vitro, the proliferative ability of T cells or B cells from EAMG rats was inhibited when they were cocultured with BMSC at proper ratios. This inhibitory effect was at least partially dependent on the secretion of IDO. We also determined that the development of EAMG is accompanied by an imbalance among the Th1, Th2, Th17, and Treg cell subsets, and that this can be corrected by the administration of BMSC, which leads to an increase of Th2 (IL‐4) and Treg (Foxp3) cells, and a reduction of Th1 (IFN‐γ) and Th17 (IL‐17) cells, through an IDO‐dependent mechanism. These results provide further insights into the pathogenesis of MG, EAMG, and other immune‐mediated diseases, and support a potential role for BMSC in their treatment.
Human Th17 cells: Are they different from murine Th17 cells?
Authors: Annunziato Francesco , Cosmi Lorenzo , Liotta Francesco , Maggi Enrico , Romagnani Sergio
Published: March 2009

Type 17 Th (Th17) cells have been identified as a distinct population of CD4+ effector T cells different from Th1 and Th2 cells. While the pre‐eminent cytokine of Th1 cells is IFN‐γ and that of Th2 cells is IL‐4, the distinctive cytokine of Th17 cells is IL‐17A. However, although murine and human Th1 and Th2 cells exhibit strong similarities, human and murine Th17 cells seem to differ in several aspects.
Cytokine mediators of Th17 function
Authors: Spolski Rosanne , Leonard Warren J.
Published: March 2009

Th17 cells were identified as an independent lineage of CD4+ T cells that secrete a distinctive set of immunoregulatory cytokines, including IL‐17A, IL‐17F, IL‐22, and IL‐21. These cytokines collectively play roles in inflammation and autoimmunity and in response to extracellular pathogens. The expression of the lineage‐specific transcription factor RORγt leads to Th17 lineage commitment; however, it has become increasingly clear that the population of cells designated as Th17 cells is not homogeneous. Although these cells collectively produce characteristic Th17 cytokines, not all are produced by each individual cell in the population. The cytokines produced by individual cells are presumably affected in part by the specific local cytokine milieu. In this review, we discuss the current understanding of the specific functional characteristics and regulation of Th17 cytokines and clarify how they mediate the actions of Th17 cells.
IL‐17‐producing γδ T cells
Authors: O'Brien Rebecca L. , Roark Christina L. , Born Willi K.
Published: March 2009

IL‐17 is produced not only by CD4+ αβ T cells, but also CD8+ αβ T cells, NKT cells, and γδ T cells, plus some non‐T cells, including macrophages and neutrophils. The ability of IL‐17 to deploy neutrophils to sites of inflammation imparts this cytokine with a key role in diseases of several types. Surprisingly, γδ T cells are responsible for much of the IL‐17 produced in several disease models, particularly early on.
p21waf1/CIP1, a CDK inhibitor and a negative feedback system that controls macrophage activation
Authors: Lloberas Jorge , Celada Antonio
Published: March 2009

p21WAF1/CIP1 (p21) is a crucial CDK inhibitor that controls the cell cycle. This molecule is also involved in the regulation of apoptosis and gene expression. However, like many other cell regulators, the functional activity of p21 depends on its cellular context and is controlled through phosphorylation and protein–protein interactions. p21 is also important in cells of the immune system regulating the cell cycle and preventing apoptosis of macrophages. In this issue of the European Journal of Immunology, two reports investigate the role of p21 further determining its critical role as a negative regulator of macrophage activation, in particular inhibiting the LPS‐dependent induction of TNF‐α and IL‐1β. The inhibition mediated by p21 is shown to be related to NF‐κB activity. Furthermore, the observation that p21−/− mice are more susceptible to septic shock supports the notion that p21 is a negative regulator of macrophage activation and therefore a potential new target to control inflammatory diseases.
Cover Picture: Eur. J. Immunol. 3/09
Authors: Ouyang Wenjun , Filvaroff Ellen , Hu Yan , Grogan Jane
Published: March 2009

The cover picture features the hallmark set of scales representing the balancing of opinions in our Viewpoint series, with the schematic cell indicating the focus of this issue's series, i.e. Th17 cells/IL‐17. The schematic is taken from the article by Ouyang et al. (pp. 670–675) in which the therapeutic potential of drugs targeting the Th17 pathway for the treatment of autoimmune disease is considered.
The Day of Immunology 2009
Authors: Kaufmann Stefan H. E. , Hahner Astrid
Published: March 2009

The year 2009 sees the bicentennial of Darwin's birth and the sesquicentennial of his major publication On the Origin of Species. Thus, 2009 will witness numerous attempts to interpret scientific results from an evolutionary standpoint. For immunology, this makes a lot of sense. The immune response has evolved as a countermeasure to nature's most evolution‐prone organisms – the microbes. The generation times of many microbes are in the range of minutes to hours, hence a million times faster than humans. Owing to their rapid generation times, microbes are best equipped to follow Darwinian evolution relying on random mutation followed by selection of the fittest.
An Efficient Route to Group 6 and 8 Metallaborane Compounds: Synthesis of arachno‐[Cp*Fe(CO)B3H8] and closo‐[(Cp*M)2B5H9] (M = Mo, W)
Authors: Geetharani K. , Kumar Bose Shubhankar , Pramanik Goutam , Kumar Saha Tanmoy , Ramkumar V. , Ghosh Sundargopal
Published: March 2009

Reaction of [Cp*Fe(CO)2I] (Cp* = η5‐C5Me5) with an excess amount of BH3·thf in toluene at 75 °C or with LiBH4 at –78 °C leads to the isolation of hydrogen‐rich ferraborane arachno‐[Cp*Fe(CO)B3H8] in good yield. In a similar fashion, reaction of [Cp*M(CO)3Cl] (M = Mo and W) with an excess amount of BH3·thf at 80 °C or at –78 °C with LiBH4 yielded metallaboranes [(Cp*M)2B5H9] (M = Mo, W). Isolated yields of closo‐[(Cp*M)2B5H9], (M = Mo and W), both from LiBH4 and BH3·thf, are good. All compounds were characterized in solution by IR, 1H, 11B, and 13C NMR spectroscopy and mass spectrometry and the structural types were unequivocallyestablished by crystallographic analysis of arachno‐[Cp*Fe(CO)B3H8].(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Palladium Complexes Containing Potentially Chelating Pyridylidene‐Type Carbene Ligands
Authors: Poulain Aurélie , Neels Antonia , Albrecht Martin
Published: March 2009

Oxidative addition of 2‐bromopyridine derivatives containing a potentially chelating donor group E (E = NMe2, SMe, SPh) to palladium(0) gives C,E‐bound pyridylpalladium(II) complexes. Mono‐, di‐, and polymeric palladium complexes are obtained depending on the type of functionalization at the pyridyl nitrogen. With a lone pair at nitrogen, dimetallic products are isolated, while protonation gives monometallic pyridylidene‐type complexes. Remarkably, N‐methylation inhibits chelating ligand coordination and a one‐dimensional polymer is formed instead. Heck‐type arylation of styrene is used as a probe for the catalytic activity of the palladium pyridylidene complexes and reveals moderate activities. Mechanistic studies support a heterogeneous mode of action, including loss of the pyridylidene‐type ligand from the metal coordination sphere.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Systematic Electronic Control in Ambipolar Compounds Optimizes Their Photoluminescence Properties: Synthesis, Characterization, and Device Fabrication of Four‐Coordinate Boron Compounds Containing an N,O‐Chelating Oxazolylphenolate Ligand
Authors: Son Ho‐Jin , Han Won‐Sik , Wee Kyung‐Ryang , Chun Ji‐Yun , Choi Kyu‐Bum , Han Su Jung , Kwon Soon‐Nam , Ko Jaejung , Lee Chongmok , Kang Sang Ook
Published: March 2009

A series of four‐coordinate boron compounds of the type N,O‐(OPhOxZArX)BPh2 or N,O‐(OPhOxZNPh2)BPh2 (5a–g) has been prepared by treating triphenylboron (TPB) with2‐(4,4‐dimethyl‐4,5‐dihydrooxazol‐2‐yl)‐4‐X‐arylphenols(HOPhOxZArX; 4a–f) or 2‐(4,4‐dimethyl‐4,5‐dihydrooxazol‐2‐yl)‐4‐(4‐diphenylamino)phenol (HOPhOxZNPh2; 4g). A systematic change in the electronic structures is achieved in these compounds by incorporating electron‐withdrawing (EW) and ‐donating (ED) groups [ArX (X = 4‐cyano‐, 2,4‐difluoro‐, 4‐chloro‐, phenyl, 4‐methoxy‐, and 4‐dimethylaminophenyl) or NPh2] at the 4‐position of the phenoxide. The absorption and emission maxima of the ED groups show a significant red‐shift compared to those observed in the EW groups. This red‐shift suggests that π‐conjugation is effectively extended over the arylphenoxides and oxazoline moiety once the boron center has been plugged into the corresponding ligands. The gradual decrease observed in the bandgaps on going from EW to ED groups is found to be in agreement with the increase in oxidation potentials determined by the cyclic voltammetry (CV) experiments. In particular, a Hammet plot between the EW and ED substituents and oxidation potentials confirms the ground state electronic perturbation. Such alterations are attributed mainly to an elevation of the energy levels of the HOMOs), as further confirmed by a series of theoretical calculations on the frontier orbitals of each system. The ED group (‐NPh2) substituted compound 5g shows a bipolar character due to intramolecular charge transfer in the complex, with the highest photoluminescence quantum yield being obtained in toluene. This new boron complex was found to function as an emitter in electroluminescence (EL) devices, with a maximum brightness of 2905 cd/m2 at 13 V and a current efficiency of 1.63 cd/A at 6 mA/cm2, with a turn‐on voltage of 4.3 V.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Reactions of 3‐(Diethylboryl)stannoles with Isocyanates
Authors: Wrackmeyer Bernd , Thoma Peter , Kempe Rhett
Published: March 2009

Diethynyl(diphenyl)stannane was prepared, fully characterised in solution and in the solid state, and its reaction with triethylborane, BEt3, afforded 3‐(diethylboryl)‐4‐ethyl‐1,1‐diphenyl‐stannole in essentially quantitative yield. Treatment with isocyanates converted this stannole and the known analogous 1,1‐dimethyl derivative into novel bicyclic compounds containing an aminoborane unit. These reactions were found to proceed diastereoselectively, again in essentially quantitative yield. The bicyclic compounds react with methanol through rearrangement and elimination of ethyl(dimethoxy)borane to give novel 1‐stannacyclopent‐3‐ene derivatives, one of which could be structurally characterised by X‐ray analysis. All final products and intermediates were studied in solution by multinuclear NMR spectroscopy (1H, 11B, 13C, 119Sn NMR).(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Synthesis of Hafnacyclopentanes from Hafnocene Alkyne Complexes: Influence of Styrene Substituents on the C–C Coupling Regioselectivity
Authors: Beweries Torsten , Burlakov Vladimir V. , Arndt Perdita , Baumann Wolfgang , Spannenberg Anke , Rosenthal Uwe
Published: March 2009

The alkyne complexrac‐(ebthi)Hf(η2‐Me3SiC2SiMe3) (1)[ebthi = 1,2‐ethylene‐1,1′‐bis(η5‐tetrahydroindenyl)] reacts with styrene andp‐(trifluoromethyl)styrene to give hafnacyclopentanes2and3, respectively. C–C coupling proceeds in different ways: whereas for complex2a hafnacyclopentane with substituents in the α,β‐position is formed, in the latter case only α,α coupling was observed. Complexes2and3can be activated with B(C6F5)3to form active catalysts for the polymerization of ethylene.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
New Mixed Li/Mg and Li/Mg/Zn Amides for the Chemoselective Metallation of Arenes and Heteroarenes
Authors: Rohbogner Christoph J. , Wunderlich Stefan H. , Clososki Giuliano C. , Knochel Paul
Published: March 2009

New mixed Li/Mg and Li/Mg/Zn amides have been synthesized starting from readily prepared secondary amines. They allow a highly chemoselective directed magnesiation or zincation of various polyfunctional aromatics and heteroaromatics. The kinetic basicity, solubility and stability of these new bases have been compared with those of the corresponding 2,2,6,6‐tetramethylpiperamide‐derived bases.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Total Synthesis of Graphislactones A, C, D, and H, of Ulocladol, and of the Originally Proposed and Revised Structures of Graphislactones E and F
Authors: Altemöller Martina , Gehring Timo , Cudaj Judith , Podlech Joachim , Goesmann Helmut , Feldmann Claus , Rothenberger Alexander
Published: March 2009

Graphislactones A–H and the structurally related ulocladol are highly oxygenated resorcylic lactones produced by lichens and fungi. We present total syntheses of graphislactones A, C–F, H and of ulocladol. Graphislactones E, F, and H were synthesized for the first time. The spectra of graphislactones E and F synthesized as the originally proposed structures were not in agreement with published data. Consequently, revised structures for these compounds are proposed, whose correctness is unambiguously proven by total synthesis and comparison of the spectroscopic data. Key steps in all syntheses are Suzuki couplings for the construction of the central biaryl bond and Dakin reactions to supply further hydroxy groups required in these highly oxygenated substrates. Graphislactones A, C, and H, acylated graphislactone D and ulocladol were prepared in 8–11 steps with 7–20 % yield starting with purchasable compounds, where the longest linear sequence consists of 5–9 steps. The syntheses are thus significantly shorter than the previously published syntheses of graphislactones A–D and of ulocladol. Graphislactones E and F were synthesized in 8 steps, where the longest linear sequences consist of 6 and 5 steps, respectively. They were isolated as the respective acetylated compounds with 25 and 10 % yield.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)