bluuebunny/crossref_metadata_2025 huggingface dataset:
Spinal Cord Herniation
Authors: Marshman Laurence
Published: May 2009

Anterior spinal cord herniation is a well-documented condition in which the thoracic cord becomes tethered within a defect in the anterior dura mater. Typical procedures have involved a posterior approach with direct manipulation of the thoracic cord to expose and blindly release its point of tethering. The authors report three cases in which a novel approach for the treatment of anterior thoracic cord herniation was performed, cord manipulation and traction are minimized, and direct dural repair of the defect is performed.
Mechanical-Thermal Noise in Drive-Mode of a Silicon Micro-Gyroscope
Authors: Yang Bo , Wang Shourong , Li Hongsheng , Zhou Bailing
Published: May 2009

A new closed-loop drive scheme which decouples the phase and the gain of the closed-loop driving system was designed in a Silicon Micro-Gyroscope (SMG). We deduce the system model of closed-loop driving and use stochastic averaging to obtain an approximate “slow” system that clarifies the effect of thermal noise. The effects of mechanical-thermal noise on the driving performance of the SMG, including the noise spectral density of the driving amplitude and frequency, are derived. By calculating and comparing the noise amplitude due to thermal noise both in the opened-loop driving and in the closed-loop driving, we find that the closed-loop driving does not reduce the RMS noise amplitude. We observe that the RMS noise frequency can be reduced by increasing the quality factor and the drive amplitude in the closed-loop driving system. The experiment and simulation validate the feasibility of closed-loop driving and confirm the validity of the averaged equation and its stablility criterion. The experiment and simulation results indicate the electrical noise of closed-loop driving circuitry is bigger than the mechanical-thermal noise and as the driving mass decreases, the mechanical-thermal noise may get bigger than the electrical noise of the closed-loop driving circuitry.
Concomitant Renal Cell Carcinoma and Chronic Myelogenous Leukemia: Use of a Targeted Approach
Authors: Pal S. K. , Gupta R. K. , Dosik G. , Figlin R. A.
Published: May 2009

Numerous therapeutic options have been introduced for metastatic renal cell carcinoma (mRCC) in recent years, including monoclonal antibodies such as bevacizumab and small-molecule tyrosine kinase inhibitors such as sunitinib and sorafenib. Similarly, several other small-molecule inhibitors—including imatinib, dasatinib, and nilotinib—have been approved for the treatment of chronic myelogenous leukemia (CML). The combination of these targeted agents is an area of intense clinical investigation. Here, we describe a patient diagnosed with mRCC while on imatinib therapy for CML. Treatment of this patient with the combination of bevacizumab and imatinib led to a 6-month period of stable disease, with no treatment-related adverse events. More extensive clinical exploration of this combination of agents may therefore be warranted.
First-Line Therapy with Sunitinib in Advanced Renal Cell Carcinoma: Interpretation of the Overall Survival Data from asco 2008
Authors: Wood L.
Published: May 2009

Sunitinib is now a standard first-line therapy for metastatic clear-cell kidney cancer. This paper focuses on interpretation of the overall survival data presented at the 2008 annual meeting of the American Society of Clinical Oncology from the pivotal phase III trial comparing sunitinib with interferon in the first-line setting. The previously published progression-free survival and response rate data from that study are also summarized.
Employee perceptions of the management of cultural diversity and workplace transformation
Authors: Zulu Pascal S. , Parumasur Sanjana B.
Published: May 2009

This study assesses managerial perceptions of the management of cultural diversity and workplace transformation in three production companies in Gauteng. A sample comprising 668 employees was drawn from a population of 1 259 (53% response rate) using simple random sampling and data were collected through self-developed questionnaires and personal interviews. Data were analysed using descriptive and inferential statistics. The results indicate that whilst the South African Transformation (SAT) Agenda has propelled change in the political and economic spheres, similar developments have not been realised in the South African labour market. Hence, based on the findings, recommendations are made to enhance the management of cultural diversity and workplace transformation, and the need for urgent government intervention, through legislative amendments, is emphasised.
Prediction of type A behaviour: A structural equation model
Authors: Van Wyk René , Boshoff André B. , Nieman Gideon , Van Vuuren Jurie , Pretorius Marius
Published: May 2009

The predictability of Type A behaviour was measured in a sample of 375 professionals with a shortened version of the Jenkins Activity Survey (JAS). Two structural equation models were constructed with the Type A behaviour achievement sub-scale and global (total) Type A as the predictor variables. The indices showed a reasonable-to-promising fit with the data. Type A achievement was reasonably predicted by service-career orientation, internal locus of control, power self-concept and economic innovation. Type A global was also predicted by internal locus of control, power self-concept and the entrepreneurial attitude of achievement and personal control.
Microstructured Arrays of TiO2 Nanotubes for Improved Photo‐Electrocatalysis and Mechanical Stability
Authors: Wang Daoai , Hu Tianchang , Hu Litian , Yu Bo , Xia Yanqiu , Zhou Feng , Liu Weimin
Published: May 2009

The preparation of micropatterned TiO2 nanotubes (NTs) with tunable morphologies by combining laser micromachining technology and an anodization method is reported. The micropatterned structure can be easily designed and fabricated by laser micromachining a titanium substrate, further anodization of which gives nanotube arrays perpendicularly oriented to the titanium surface. The patterned TiO2 NTs show dramatically improved photocurrent and photocatalytic performances because of their enhanced surface area and light‐harvesting capability. The photocurrent density and incident‐photon‐to‐current efficiency at the peak absorption increases by 48 and 39%, respectively, compared to a TiO2 NT array without a patterned structure. It was also found that micropatterning dramatically improves the mechanical stability of the TiO2 NTs on the substrate, which otherwise were liable to peel off from the substrate surface. The strategy will reasonably expand the application of TiO2 NTs in a variety of fields that require enhanced photo‐electrocatalysis and mechanical stability.
The Role of OTS Density on Pentacene and C60 Nucleation, Thin Film Growth, and Transistor Performance
Authors: Virkar Ajay , Mannsfeld Stefan , Oh Joon Hak , Toney Michael F. , Tan Yih Horng , Liu Gang‐yu , Scott J. Campbell , Miller Robert , Bao Zhenan
Published: May 2009

In organic thin film transistors (OTFTs), charge transport occurs in the first few monolayers of the semiconductor near the semiconductor/dielectric interface. Previous work has investigated the roles of dielectric surface energy, roughness, and chemical functionality on performance. However, large discrepancies in performance, even with apparently identical surface treatments, indicate that additional surface parameters must be identified and controlled in order to optimize OTFTs. Here, a crystalline, dense octadecylsilane (OTS) surface modification layer is found that promotes two‐dimensional semiconductor growth. Higher mobility is consistently achieved for films deposited on crystalline OTS compared to on disordered OTS, with mobilities as high as 5.3 and 2.3 cm2 V−1 s−1 for C60 and pentacene, respectively. This is a significant step toward morphological control of organic semiconductors which is directly linked to their thin film charge carrier transport.
Block‐Copolymer‐Templated Synthesis of Electroactive RuO2‐Based Mesoporous Thin Films
Authors: Sassoye Capucine , Laberty Christel , Le Khanh Hung , Cassaignon Sophie , Boissière Cédric , Antonietti Markus , Sanchez Clément
Published: May 2009

RuO2‐based mesoporous thin films of optical quality are synthesized from ruthenium‐peroxo‐based sols using micelle templates made of amphiphilic polystyrene‐polyethylene oxide block copolymers. The mesoporous structure and physical properties of the RuO2 films (mesoporous volume: 30%; pore diameter: ∼30 nm) can be controlled by the careful tuning of both the precursor solution and thermal treatment (150–350 °C). The optimal temperature that allows control of both mesoporosity and nanocristallinity is strongly dependent on the substrate (silicon or fluorine‐doped tin oxide). The structure of the resulting mesoporous films are investigated using X‐ray diffraction, X‐ray photoelectron spectroscopy, and atomic force microscopy. Mesoporous layers are additionally characterized by transmission and scanning electron microscopy and ellipsometry while their electrochemical properties are analyzed via cyclic voltammetry. Thick mesoporous films of ruthenium oxide hydrates, RuO2 · xH2O, obtained using a thermal treatment at 280 °C, exhibit capacitances as high as 1000 ± 100 F g−1 at a scan rate of 10 mV s−1, indicating their potential application as electrode materials.
Charge Transport in Disordered Organic Materials and Its Relevance to Thin‐Film Devices: A Tutorial Review
Authors: Tessler Nir , Preezant Yevgeni , Rappaport Noam , Roichman Yohai
Published: May 2009

Semiconducting polymers and small molecules form an extremely flexible class of amorphous materials that can be used in a wide range of applications, some of which are display, radio‐frequency tags, and solar cells. The rapid progress towards functional devices is occurring despite the lack of sufficient understanding of the physical processes and very little experience in device engineering. This tutorial review aims to provide sufficient intuitive background to draw more researchers to look into the fundamental aspects of device physics and engineering.
First partial face and upper dentition of the Middle Miocene hominoid Dryopithecus fontani from Abocador de Can Mata (Vallès‐Penedès Basin, Catalonia, NE Spain): Taxonomic and phylogenetic implications
Authors: Moyà‐Solà Salvador , Köhler Meike , Alba David M. , Casanovas‐Vilar Isaac , Galindo Jordi , Robles Josep M. , Cabrera Lluís , Garcés Miguel , Almécija Sergi , Beamud Elisabet
Published: May 2009

A well‐preserved 11.8‐million‐years‐old lower face attributed to the seminal taxon Dryopithecus fontani (Primates, Hominidae) from the Catalan site ACM/C3‐Ae of the Hostalets de Pierola area (Vallès‐Penedès Basin, Catalonia, NE Spain) is described. The new data indicate that D. fontani is distinct at the genus level from Late Miocene European taxa previously attributed to Dryopithecus, which are here reassigned to Hispanopithecus. The new facial specimen also suggests that D. fontani and the Middle Miocene Pierolapithecus catalaunicus are not synonymous. Anatomical and morphometric analyses further indicate that the new specimen shows a combination of lower facial features—hitherto unknown in Miocene hominoids—that resembles the facial pattern of Gorilla, thus providing the first nondental evidence of gorilla‐like lower facial morphology in the fossil record. Considering the current evidence, the gorilla‐like facial pattern of D. fontani is inferred to be derived relative to previously known stem hominids, and might indicate that this taxon is either an early member of the Homininae or, alternatively, a stem hominid convergent with the lower facial pattern of Gorilla. The biogeographic implications of both alternatives are discussed. This new finding in the Hostalets de Pierola section reinforces the importance of this area for understanding the elusive question of the Middle Miocene origin and early radiation of great apes. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
The effects of socioeconomic status on endochondral and appositional bone growth, and acquisition of cortical bone in children from 19th century Birmingham, England
Authors: Mays Simon , Ives Rachel , Brickley Megan
Published: May 2009

Endochondral growth, appositional growth, and acquisition of cortical bone thickness in the femur are investigated in subadult skeletons (N = 43, dental age range birth to 12 years) from the 19th‐century AD burial site of St. Martin's churchyard, Birmingham, England. Endochondral growth is monitored using diaphyseal femoral length. Appositional growth is monitored using radiographic midshaft mediolateral width and acquisition of cortical bone using combined mediolateral cortical thickness measured at the midshaft from radiographs. The methodology involves plotting these variables against dental age. Growth is compared in children of differing socioeconomic status. Higher and lower status individuals are identified in the assemblage by their burial in brick vaults in the case of the former and in earth‐cut graves in the case of the latter. The relationships between bone dimensions and dental age are described using a polynomial regression procedure, and analysis of regression residuals is used to evaluate differences in bone dimension‐for‐dental age between the two status groups. Results show that lower socioeconomic status individuals had lower cortical thickness‐for‐dental age than those of higher status. This was interpreted as likely reflecting poorer nutrition in the children of lower socioeconomic backgrounds. There was no patterning with respect to socioeconomic status in femur diaphyseal length or midshaft width. The results support the idea that, for skeletal populations, growth in cortical thickness may be a more sensitive indicator of adverse conditions in childhood than growth in bone length or width. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Near Eastern Neolithic genetic input in a small oasis of the Egyptian Western Desert
Authors: Kujanová Martina , Pereira Luísa , Fernandes Verónica , Pereira Joana B. , Černý Viktor
Published: May 2009

The Egyptian Western Desert lies on an important geographic intersection between Africa and Asia. Genetic diversity of this region has been shaped, in part, by climatic changes in the Late Pleistocene and Holocene epochs marked by oscillating humid and arid periods. We present here a whole genome analysis of mitochondrial DNA (mtDNA) and high‐resolution molecular analysis of nonrecombining Y‐chromosomal (NRY) gene pools of a demographically small but autochthonous population from the Egyptian Western Desert oasis el‐Hayez. Notwithstanding signs of expected genetic drift, we still found clear genetic evidence of a strong Near Eastern input that can be dated into the Neolithic. This is revealed by high frequencies and high internal variability of several mtDNA lineages from haplogroup T. The whole genome sequencing strategy and molecular dating allowed us to detect the accumulation of local mtDNA diversity to 5,138 ± 3,633 YBP. Similarly, theY‐chromosome gene pool reveals high frequencies of the Near Eastern J1 and the North African E1b1b1b lineages, both generally known to have expanded within North Africa during the Neolithic. These results provide another piece of evidence of the relatively young population history of North Africa. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Modern human cranial diversity in the Late Pleistocene of Africa and Eurasia: Evidence from Nazlet Khater, Peştera cu Oase, and Hofmeyr
Authors: Crevecoeur Isabelle , Rougier Hélène , Grine Frederick , Froment Alain
Published: May 2009

The origin and evolutionary history of modern humans is of considerable interest to paleoanthropologists and geneticists alike. Paleontological evidence suggests that recent humans originated and expanded from an African lineage that may have undergone demographic crises in the Late Pleistocene according to archaeological and genetic data. This would suggest that extant human populations derive from, and perhaps sample a restricted part of the genetic and morphological variation that was present in the Late Pleistocene. Crania that date to Marine Isotope Stage 3 should yield information pertaining to the level of Late Pleistocene human phenotypic diversity and its evolution in modern humans. The Nazlet Khater (NK) and Hofmeyr (HOF) crania from Egypt and South Africa, together with penecontemporaneous specimens from the Peştera cu Oase in Romania, permit preliminary assessment of variation among modern humans from geographically disparate regions at this time. Morphometric and morphological comparisons with other Late Pleistocene modern human specimens, and with 23 recent human population samples, reveal that elevated levels of variation are present throughout the Late Pleistocene. Comparison of Holocene and Late Pleistocene craniometric variation through resampling analyses supports hypotheses derived from genetic data suggesting that present phenotypic variation may represent only a restricted part of Late Pleistocene human diversity. The Nazlet Khater, Hofmeyr, and Oase specimens provide a unique glimpse of that diversity. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Brief communication: Paleohistopathological analysis of pathology museum specimens: Can periosteal reaction microstructure explain lesion etiology?
Authors: Weston Darlene A.
Published: May 2009

The assertion that the microstructure of periosteal new bone formation can be used to differentiate between disease etiologies (Schultz: Yrbk Phys Anthropol 44 2001 106–147; Schultz: Identification of pathological conditions in human skeletal remains, 2nd ed. London: Academic Press 2003 73–109) was tested in a pilot‐study, using diagnosed bone specimens from St George's Hospital Pathology Museum, London, UK. Embedded bone specimens exhibiting pathological periosteal new bone formation were examined using scanning electron microscopy in back‐scattered electron imaging mode (SEM‐BSE). The results suggest that several histological features (i.e. Grenzstreifen, Polsters, and sinuous lacunae) deemed to be diagnostic of specific pathological conditions are of no specific diagnostic value, as they are encountered in pathological conditions of differing disease etiology. These results tie in with a previous investigation demonstrating a lack of diagnostic qualitative or quantitative characteristics seen in the macroscopic and radiographic appearance of periosteal reactions (Weston: Am J Phys Anthropol 137 2008 48–59). Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
X‐chromosome lineages and the settlement of the Americas
Authors: Bourgeois Stephane , Yotova Vania , Wang Sijia , Bourtoumieu Sylvie , Moreau Claudia , Michalski Roman , Moisan Jean‐Paul , Hill Kim , Hurtado Ana M. , Ruiz‐Linares Andres , Labuda Damian
Published: May 2009

Most genetic studies on the origins of Native Americans have examined data from mtDNA and Y‐chromosome DNA. To complement these studies and to broaden our understanding of the origin of Native American populations, we present an analysis of 1,873 X‐chromosomes representing Native American (n = 438) and other continental populations (n = 1,435). We genotyped 36 polymorphic sites, forming an informative haplotype within an 8‐kb DNA segment spanning exon 44 of the dystrophin gene. The data reveal continuity from a common Eurasian ancestry between Europeans, Siberians, and Native Americans. However, the loss of two haplotypes frequent in Eurasia (18.8 and 7%) and the rise in frequency of a third haplotype rare elsewhere, indicate a major population bottleneck in the peopling of the Americas. Although genetic drift appears to have played a greater role in the genetic differentiation of Native Americans than in the latitudinally distributed Eurasians, we also observe a signal of a differentiated ancestry of southern and northern populations that cannot be simply explained by the serial southward dilution of genetic diversity. It is possible that the distribution of X‐chromosome lineages reflects the genetic structure of the population of Beringia, itself issued from founder effects and a source of subsequent southern colonization(s). Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Use and misuse of the reduced major axis for line‐fitting
Authors: Smith Richard J.
Published: May 2009

Many investigators use the reduced major axis (RMA) instead of ordinary least squares (OLS) to define a line of best fit for a bivariate relationship when the variable represented on theX‐axis is measured with error. OLS frequently is described as requiring the assumption thatXis measured without error while RMA incorporates an assumption that there is error inX. Although an RMA fit actually involves a very specific pattern of error variance, investigators have prioritized the presence versus the absence of error rather than the pattern of error in selecting between the two methods. Another difference between RMA and OLS is that RMA is symmetric, meaning that a single line defines the bivariate relationship, regardless of which variable isXand which isY, while OLS is asymmetric, so that the slope and resulting interpretation of the data are changed when the variables assigned toXandYare reversed. The concept of error is reviewed and expanded from previous discussions, and it is argued that the symmetry‐asymmetry issue should be the criterion by which investigators choose between RMA and OLS. This is a biological question about the relationship between variables. It is determined by the investigator, not dictated by the pattern of error in the data. IfXis measured with error but OLS should be used because the biological question is asymmetric, there are several methods available for adjusting the OLS slope to reflect the bias due to error. RMA is being used in many analyses for which OLS would be more appropriate. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
Even adult sex ratios in lemurs: Potential costs and benefits of subordinate males in Verreaux's sifaka (Propithecus verreauxi) in the Kirindy Forest CFPF, Madagascar
Authors: Kappeler Peter M. , Mass Vanessa , Port Markus
Published: May 2009

Optimal group size and composition are determined by both the costs and benefits of group living for the group's members. Verreaux's sifakas (Propithecus verreauxi), a diurnal lemur, form multimale multifemale groups with the tendency toward even adult sex ratios despite a small average number of females per group. The unexpected presence of multiple adult males may be explained by tolerance of other group members if subordinate males provide benefits to the group that outweigh the costs associated with their presence. Results based on both demographic data collected over a 13‐year period and behavioral observations suggest that subordinate males provide no benefits in terms of infant survival and defense against group takeover by outside males. Although groups with more males are more likely to win intergroup encounters, subordinate males do not participate in these encounters more often than expected. Subordinate males are not costly to other group members in terms of direct intragroup feeding competition, but aggression rates between dominant and immigrated subordinate males increase in the mating season. Even though subordinate males provide very few benefits to the group, they are not very costly either and thus may be tolerated by resident females and dominant males. This tolerance may help to partially explain the tendency towards their unusual adult sex ratio. Am J Phys Anthropol, 2009. © 2009 Wiley‐Liss, Inc.
A Supramolecular Approach for Preparation of Size‐Controlled Nanoparticles
Authors: Wang Hao , Wang Shutao , Su Helen , Chen Kuan‐Ju , Armijo Amanda Lee , Lin Wei‐Yu , Wang Yanju , Sun Jing , Kamei Ken‐ichiro , Czernin Johannes , Radu Caius G. , Tseng Hsian‐Rong
Published: May 2009

Aus drei Bausteinen entstehen auf der Grundlage eines Cyclodextrin‐Adamantan‐Erkennungssystems supramolekulare Nanopartikel (SNPs) variabler Größe (30–450 nm). Die Bioverteilung und Lymphknotendrainage der SNPs in Mäusen wurde mit Positronenemissionstomographie untersucht. Die Größen der SNPs beeinflussen ihr In‐vivo‐Verhalten (siehe Bild).

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Bioinspired Colorimetric Detection of Calcium(II) Ions in Serum Using Calsequestrin‐Functionalized Gold Nanoparticles
Authors: Kim Sunghyun , Park Jeong Won , Kim Dongkyu , Kim Daejin , Lee In‐Hyun , Jon Sangyong
Published: May 2009

Zuviel Calcium im Blut? Mit Calsequestrin (CSQ) funktionalisierte Goldnanopartikel durchlaufen eine Calcium‐abhängige CSQ‐Polymerisation, die mit einem Farbwechsel (siehe Bild) und einer Niederschlagsbildung einhergeht. Dieses Sensorsystem ist spezifisch für Ca2+‐Ionen. Die Unterschiede zwischen normalen und krankheitsbedingten (hypercalcämischen) Ca2+‐Ionenkonzentrationen im Serum lassen sich mit bloßem Auge wahrnehmen.

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Disterolphospholipids: Nonexchangeable Lipids and Their Application to Liposomal Drug Delivery
Authors: Huang Zhaohua , Jaafari Mahmoud Reza , Szoka Francis C.
Published: May 2009

Cholesterin an der Kette: Der Cholesterinaustausch ist einer der Hauptgründe für die Unbeständigkeit von Liposomen im Blut. Durch Bildung eines kovalent verbundenen Cholesterin‐Glycerophosphocholin‐Hybrids bleibt der stabilisierende Effekt des freien Cholesterins erhalten, sein Austritt aus der Doppelschicht wird aber verhindert. Disterophospholipide wie1sind somit wertvolle Komponenten für Liposomenformulierungen.

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Nuclear Spin‐Noise Spectra of Hyperpolarized Systems
Authors: Desvaux Hervé , Marion Denis J. Y. , Huber Gaspard , Berthault Patrick
Published: May 2009

Das NMR‐Spinrauschen eignet sich besonders, um verdünnte hyperpolarisierte Spezies zu charakterisieren. Durch kontinuierliche Aufzeichnung der Rauschabsorption an der Larmor‐Frequenz lassen sich T1 und T2* unabhängig vom statischen magnetischen Feld bestimmen. Induktiv gekoppelte Mikrospiralen im Inneren der NMR‐Röhrchen (siehe Bild) ermöglichen die Aufnahme von 129Xe‐Spinrauschenspektren ohne Radiofrequenzanregung.

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Anellierung und Arylierung stabilisieren Porphyrinoide
Authors: Jux Norbert
Published: May 2009

Mehr π, bitte: Ein nichtmetalliertes, benzanelliertes Triphyrin mit [2.1.1]‐Brückenmuster (1) und ein von Azulen abgeleitetes, tetrakationisches All‐Kohlenstoff‐Porphyrinoid (2) wurden hergestellt. 1 kann Ausgangspunkt für eine eigenständige Metallkomplexchemie der Triphyrine sein, und 2 könnte sich für die molekulare Elektronik und als Rezeptor für schwach bindende Anionen eignen.

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Symmetry‐Based Design for the Chemoenzymatic Synthesis of Oseltamivir (Tamiflu) from Ethyl Benzoate
Authors: Sullivan Bradford , Carrera Ignacio , Drouin Melissa , Hudlicky Tomas
Published: May 2009

Ausgehend von Ethylbenzoat gelang eine kurze chemoenzymatische Formalsynthese von Oseltamivir. Die Schlüsselschritte sind eine durch Toluoldioxygenase vermittelte Dihydroxylierung, eine Hetero‐Diels‐Alder‐Reaktion und die Bildung einer Acetamidofunktion an C4. Die Synthese benötigt insgesamt zehn Stufen und umfasst eine Verschiebung der Doppelbindung unter Eliminierung einer Hydroxygruppe an C2 (siehe Schema).

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A Supramolecular Approach for Preparation of Size‐Controlled Nanoparticles
Authors: Wang Hao , Wang Shutao , Su Helen , Chen Kuan‐Ju , Armijo Amanda Lee , Lin Wei‐Yu , Wang Yanju , Sun Jing , Kamei Ken‐ichiro , Czernin Johannes , Radu Caius G. , Tseng Hsian‐Rong
Published: May 2009

A supramolecular approach has been developed for the preparation of supramolecular nanoparticles (SNPs) with variable sizes (30–450 nm) from three different molecular building blocks using a cyclodextrin/adamantane recognition system. Positron emission tomography (PET) was employed to study the biodistribution and lymph node drainage of the SNPs in mice. The sizes of the SNPs affect their in vivo characteristics (see picture).

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Structural Characterization and Remarkable Axial Ligand Effect on the Nucleophilic Reactivity of a Nonheme Manganese(III)–Peroxo Complex
Authors: Annaraj Jamespandi , Cho Jaeheung , Lee Yong‐Min , Kim Sung Yeon , Latifi Reza , de Visser Sam P. , Nam Wonwoo
Published: May 2009

The dark side of the Mn: A manganese(III) complex bearing a 13‐membered macrocyclic ligand (1, see picture) binds a peroxo ligand in a side‐on η2 fashion. The reactivity of 1 is influenced by the introduction of anionic ligands trans to the peroxo group. Electronic and structural changes upon trans‐ligand binding explain the increased nucleophilicity of the resulting complexes 1‐X.

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Asymmetric Syntheses of l,l‐ and l,d‐Di‐myo‐inositol‐1,1′‐phosphate and their Behavior as Stabilizers of Enzyme Activity at Extreme Temperatures
Authors: Longo Christina M. , Wei Yang , Roberts Mary F. , Miller Scott J.
Published: May 2009

The big “DIP”per: The preparation of both l,l‐DIP and l,d‐DIP (see structures) involves a complex case of double asymmetric induction in the key step of the synthesis. The differential ability of each isomer to contribute to thermoprotection in the context of a key enzyme has been assessed and both isomers of DIP are shown to possess biological activity.

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Efficient and Economical Access to Substituted Benzothiazoles: Copper‐Catalyzed Coupling of 2‐Haloanilides with Metal Sulfides and Subsequent Condensation
Authors: Ma Dawei , Xie Siwei , Xue Peng , Zhang Xiaojing , Dong Jinhua , Jiang Yongwen
Published: May 2009

Don′t tell azole: The first metal‐catalyzed direct coupling of metal sulfides with aryl halides and subsequent intramolecular condensation provided substituted benzothiazoles (see scheme). A wide range of functional groups are tolerated under the reaction conditions.

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End‐On Nitrogen Insertion of a Diazo Compound into a Germanium(II) Hydrogen Bond and a Comparable Reaction with Diethyl Azodicarboxylate
Authors: Jana Anukul , Sen Sakya S. , Roesky Herbert W. , Schulzke Carola , Dutta Sudipta , Pati Swapan K.
Published: May 2009

A happy ending: The germanium(II) hydride [LGeH], where L=[HC{(CMe)(2,6‐iPr2C6H3N)}2], reacts with a diazoalkane to form the hydrazone derivative (see picture). The reaction proceeds through the unprecedented end‐on nitrogen insertion of the diazo compound.

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Nuclear Spin‐Noise Spectra of Hyperpolarized Systems
Authors: Desvaux Hervé , Marion Denis J. Y. , Huber Gaspard , Berthault Patrick
Published: May 2009

Spin‐noise appeal: Detection of NMR spin‐noise is very appealing when dilute hyperpolarized species are considered. Continuous monitoring of the noise absorption at the Larmor frequency enables determination of T1 and T2*, independently of the static magnetic field. An inductively coupled microcoil located inside the NMR tube (see picture) allows acquisition of 129Xe spin‐noise spectra without radio‐frequency excitation.

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Annulation and Arylation Stabilize New Porphyrinoids
Authors: Jux Norbert
Published: May 2009

More π, please! A free‐base, benzannelated triphyrin with a [2.1.1] bridging pattern (1) and an azulene‐derived tetracationic all‐carbon porphyrinoid (2) are discussed. Compound 1 can be used to form metal triphyrin complexes, and 2 shows potential in molecular electronics and as a receptor for weakly binding anions.

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Reactive extrusion process for the grafting of maleic anhydride onto linear low‐density polyethylene with ultraviolet radiation
Authors: Saade‐Caballero H. , Martínez‐Colunga J. G.
Published: May 2009

In this work, we chemically modified linear low‐density polyethylene with maleic anhydride in the molten state using, in a first step, different doses of ultraviolet irradiation to generate hydroperoxide groups, which were highly reactive at the processing temperature. Then, in a second reactive extrusion step, maleic anhydride was grafted to the linear low‐density polyethylene under different processing conditions. Characterization of the modified and unmodified linear low‐density polyethylene material was performed with Fourier transform infrared spectroscopy, differential scanning calorimetry, and nuclear magnetic resonance. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Studies on the influence of molecular weight and isotacticity of polypropylene on the formation of mesomorphic phase
Authors: Singh Gurmeet , Kaur Sukhdeep , Kothari Ajay V. , Naik Dhananjay G. , Vyas Priyanshu B. , Gupta Virendra K.
Published: May 2009

Polypropylene (PP) blends with various molecular weight and isotacticity were prepared through solution blending and subjected to rapid melt quenching. Structural changes in the PP matrix during mesomorphic phase formation were measured by FTIR spectroscopy and wide‐angle X‐ray diffraction measurements. The blends with different molecular weight and isotacticity provided the pathway to understand their influence on mesomorphic phase formation. It is observed that low molecular weight PP with low isotacticity forms mesomorphic phase, whereas high molecular weight and low isotactic PP does not lead to the formation of mesomorphic phase. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Study of the behavior of blends of a poly(hydroxybutyrate‐valerate) copolymer, polypropylene, and SEBS
Authors: Marcilla A. , Garcia‐Quesada J. C. , Lopez M. , Gil E.
Published: May 2009

Polyhydroxyalkanoates are a type of polymers with a clear renewable origin, as different types of microorganisms can produce them. Unfortunately, their mechanical properties are not usually as good as those of conventional polymers and for a moment their price is relatively higher; these are two of the reasons why it is suggested in the bibliography that they can be employed forming part of blends with conventional polymers. In the present work, blends of a poly(hydroxybutyrate‐valerate) (PHBV) copolymer and a polypropylene resin have been successfully processed using PHBV concentrations up to 20 phr with internal mixer and a hot plate press. Processability and applicability of such blends logically depend on their properties, and for this reason morphology, rheological, thermal properties, and tensile strength for all samples have been evaluated. Ternary blends, incorporating a poly(styrene‐ethylene‐butylene) copolymer have also been obtained and the influence of the blends properties has been analyzed. Results have shown that the rheological behavior and crystallization process of the system is markedly dependent on the blend composition. Although tensile strength significantly decreases with PHBV concentration, the use of low concentrations of the styrene‐ethylene‐butylene‐styrene copolymer could improve the elongation at break to a certain extent. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Preparation and characterization of epoxidate poly(1,2‐butadiene)–toughened diglycidyl ether bisphenol‐A epoxy composites
Authors: He Jie , Wang Jinwei
Published: May 2009

By the oxidation of liquid poly(1,2‐butadiene) (LPB) with H2O2/HCOOH, epoxidate poly(1,2‐butadiene) (ELPB) was obtained as a toughening agent to prepare diglycidyl ether bisphenol‐A (DGEBA) epoxy composites by using V115 polyamide(PA) as a cross‐linking agent. DGEBA, ELPB, and the composites were effectively cured by PA at 100°C for 2 h followed by postcuring at 170°C for 1 h. Thermal gravimetric analysis results in air and nitrogen atmosphere showed that the thermal stability of composites could be improved by the addition of ELPB. Compared with DGEBA/PA, the composites exhibited a decrease in strength at yield but an increase in strain at break with the increase in ELPB amount. The composite with 10% ELPB exhibited both thermal stability and tenacity superior to those of DGEBA/PA and composites with 5 and 20% ELPB, respectively. The improvements in thermal and mechanical properties of composites depended on the formation of Inter Penetrating Networks (IPN) among DGEBA/PA/ELPB and their distributions in the matrix. At an appropriate ELPB amount, the IPN, mostly made of DGEBA/PA/ELPB, may be distributed more evenly in the matrix; less ELPB resulted in the formation of IPN mainly made of DGEBA/PA; excessive addition of ELPB resulted in the local aggregation of ELPB/PA and phase separations. The toughening mechanism was changed from chemically forming IPN made of DGEBA/PA/ELPB to physically reinforcing DGEBA/PA by ELPB/PA with the increase in ELPB addition. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Modification of Fe2O3 and its effect on the heat‐resistance of silicone rubber
Authors: Shentu Baoqing , Gan Tengfei , Weng Zhixue
Published: May 2009

By means of the wet chemical surface modification, the surface of Fe2O3 was modified by vinyltrimethoxysilane (VTMS). Infrared spectroscopy (IR) was used to investigate the structure of the modified Fe2O3, and the result showed that VTMS has been attached onto the surface of Fe2O3. Effect of VTMS concentration on the active index of the modified Fe2O3 was also studied, and the result indicated that the active index of the modified Fe2O3 increases with the increase of VTMS concentration and the optimal concentration of VTMS is 12 wt %. The effect of the modified Fe2O3 on the tear strength of silicone rubber before and after aging was studied and it was found that in comparison with the unmodified Fe2O3 the addition of the modified Fe2O3 results in the significant increase of the tear strength before ageing because of the increase of the crosslinking density of silicone rubber. The tear strength of silicone rubber filled with the modified Fe2O3 after ageing is higher than that with the unmodified Fe2O3, indicating that the modification of Fe2O3 can improve the heat‐resistance of silicone rubber owing to the fine dispersion of the modified Fe2O3 in silicone rubber. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Comparing elastomeric behavior of block and random ethylene–octene copolymers
Authors: Wang H. P. , Chum S. P. , Hiltner A. , Baer E.
Published: May 2009

This work compared the elastomeric properties of two low‐crystallinity ethylene–octene copolymers. One was a block copolymer with lamellar crystals and the other was a random copolymer with fringed micellar crystals. The comparison of the stress–strain behavior at 23°C revealed that the initial elastic modulus and the yield stress depended only on the crystallinity of the copolymer. When the temperature was raised above 23°C, melting of the fringed micellar crystals of the random copolymer caused a rapid decrease in the modulus. Some decrease in the modulus of the block copolymer over the same temperature range was attributed to the crystalline α‐relaxation. Both polymers exhibited strain‐hardening, ultimate fracture at high strains, and high recovery after fracture. However, in the block copolymer, the onset of strain‐hardening and the ultimate fracture occurred at higher strains. The block copolymer also showed higher recovery from high strains. The initial stretching resulted in a permanent change in the stress–strain curve. It was suggested that following the onset of crystal slippage at the yield, the crystals underwent permanent structural changes through the course of the strain‐hardening region. The transformation of the fringed micellar crystals occurred at lower strains than the transformation of the lamellar crystals. The extent of the structural transformation was described by the crosslink density and the strain‐hardening coefficient extracted from elasticity theory. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Monomers for adhesive polymers, 8a crosslinking polymerization of selected N‐substituted bis(acrylamide)s for dental filling materials
Authors: Pavlinec Juraj , Moszner Norbert
Published: May 2009

The free‐radical polymerization of bis‐(N‐ethylacrylamido)‐ethylenglycol (I), N,N′‐dimethyl‐1,6‐bis (acrylamido)‐hexan (II), and N,N′‐diethyl‐1,3‐bis(acrylamido)‐propan (III) were investigated. The cross‐linking polymerization was followed in bulk by using the ampoules technique and gravimetry. Polymerizations exhibited an abnormal kinetic behavior. For the monomer II, for example, the reaction order to 2,2′‐ azobisisobutyronitril (AIBN) initiator of 1.28, and the polymerization overall activation energy of 151 kJ/mol between 50 and 75°C were determined. The increasing temperature and decreasing initiator concentration resulted in an increase of double bonds consumption in the formed polymer network. At 75°C the residual unsaturation was under 2%, compared with 9.9% at 50°C. The monomer conversion‐time dependences were complemented also with differential scanning calorimetry (DSC) recording the heat released during polymerization. The extension of peak time with decreasing the instant heat flow rate at this point sort the studied bis(acrylamide)s according the reactivity in the following sequence: monomer III > I >II. The polymer samples sol–gel analyses in ethanol allowed the determination of the molecular weight Mc between the network crosslinks. The presence of microgel particles at the very beginning of polymerization and the changes in chain conformation with temperature we consider as the way in which was affected the polymerization kinetics of these monomers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyurethane–solid wood composites. II. Flammability parameters
Authors: Gao Zhenhua , Su Wenqiang , Wu Di
Published: May 2009

Polyurethane (PU)–solid wood composites with good mechanical properties and dimensional stability have been prepared in the presence of four amine catalysts. Cone calorimetry and scanning electron microscopy (SEM) have been employed to characterize and evaluate the effects of the catalyst species on the flammability of the PU–wood composites. The results indicated that the PU–wood composites prepared in the presence of various catalysts had somewhat better flame resistance than the untreated wood control, as manifested in various flammability parameters (longer time to sustained ignition and time to peak heart rate release, larger mass and fire performance index (FPI), and lower mean HRR, mass loss rate, and peak HRR). The variations in the flame resistances of the PU–wood composites can be attributed to the various morphologies of the PU resin and the wood that resulted from the use of the various catalysts, as indicated by SEM micrographs. The PU–wood composite prepared in the presence of N‐methylmorpholine (NMM) as catalyst showed the best flame resistance, since the PU resin formed abundant PU foam that extended throughout the wood. This foam was effective in retarding the transfers of heat and combustible substances as well as the pyrogenation. In terms of FPI values, the flame resistances of these PU–wood composites decreased according to the catalyst used in the order NMM, triethanolamine, diethylenetriamine, and triethylenediamine. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Abrasion studies of nylon 6/montmorillonite nanocomposites using scanning electron microscopy, fourier transform infrared spectroscopy, and X‐ray photoelectron spectroscopy
Authors: Zhou Qi , Wang Kean , Loo Leslie S.
Published: May 2009

In this article, abrasion performance of commercial nylon 6 and nylon 6/montmorillonite (MMT) nanocomposites was studied. The polymer nanocomposites showed poor abrasion resistance compared to the neat polymer. The wear loss increased linearly with clay concentration. Changes in surface morphology, composition, and structure were investigated by scanning electron microscopy (SEM), Fourier transform infrared (FTIR)‐attenuated total reflection spectroscopy, and X‐ray photoelectron spectroscopy (XPS). SEM images showed that all the abraded surfaces contained fractured particles. However, the abraded nanocomposite surfaces had much deeper grooves compared to the homopolymer. FTIR results showed an increase in the amount of α crystals and a decrease in the amount of γ crystals on all the surfaces after abrasion. This was attributed to the strain‐induced γ to α crystal transformation. The largest amount of α crystals was formed in the abraded surface of pure nylon 6, and the amount of α crystals formed decreased with increasing MMT content. XPS results showed an increase in the [Si]/[N] elemental ratio for all nanocomposites after abrasion, indicating an increase in the clay content of the surface. Abrasive wear mechanism is as follows: (1) tensile tearing is the dominant wear mechanism for all the samples; (2) the cutting mechanism becomes more important when MMT content increases; (3) the polymer matrix is easier to be removed than clay during the abrasion process; (4) in nylon 6/MMT systems, the poor abrasion resistance is attributed to defects at the clay‐polymer interface, resulting in greater wear of the polymer matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effect of coprecipitated barium ferrite on the cure characteristics and dynamic properties of natural rubber–ferrite composites around percolation
Authors: Makled Mahmoud Hosseny Moussa , Washiya Hirohiko , Tsuda Hiroshi , Matsui Toshiyuki
Published: May 2009

The influence of coprecipitated hexagonal barium ferrite BaFe12O19 phase on the cure characteristics and dynamic properties of natural rubber–ferrite composites has been studied as a function of ferrite loading up to 220 phr (part per hundred part of rubber). Unusual characteristics of coprecipitated ferrite particles were discovered by scanning electron microscope. The results show that scorch time t10 and cure time t90 decrease dramatically with increasing ferrite content up to critical ferrite loading. After 160 phr, t90 increases sharply with increasing ferrite content, in contrast to saturation of t10. Minimum torque recorded normal behavior at low ferrite loading, whereas it decreases with increasing ferrite content at high ferrite loading because of dilution effects. The storage modulus E′ and loss modulus E″ decrease with increasing temperature. The loss tangents (tanδ) of the composites are greater than those of the pure rubber. Linear viscoelastic behavior was observed as a result of the homogeneity and compatibility of the composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Study of PET/PP/TiO2 microfibrillar‐structured composites, Part 2: Morphology and mechanical properties
Authors: Li Wenjing , Schlarb Alois K. , Evstatiev Michael
Published: May 2009

Uncompatibilized and compatibilized (polypropylene grafted maleic anhydride as compatibilizer) polyethylene terephthalate (PET)/polypropylene (PP)/TiO2 microfibrillar composites (MFC) were prepared by injection molding of the pelletized PET/PP/TiO2 drawn strands. The morphology of PET fibrils and the distribution of TiO2 particles in the composites were examined. After injection molding the preferential location of TiO2 particles is still preserved. Because of the reinforcement effect of PET fibrils, the tensile properties and impact strength of the PET/PP MFC are improved compared with the pure PP. Incorporation of TiO2 particles results in decrease of both tensile strength and impact strength of the composites. However, the compatibilized PET/PP/TiO2 MFC demonstrate better mechanical properties compared with the uncompatibilized ones. DMA analysis shows that the glass transition temperature (Tg) of PET in the uncompatibilized PET/PP/TiO2 MFC and the Tg of PP in the compatibilized PET/PP/TiO2 MFC are elevated by about 2°C. The elevation of Tg is attributed to the preferential location of TiO2 particles in the composites. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009