bluuebunny/crossref_metadata_2025 huggingface dataset:
In situ transmission electron microscopy study on Nb‐doped Pb(Zr0.95Ti0.05)O3 ceramics
Authors: Qu Weiguo , Tan Xiaoli , Yang Pin
Published: January 2009

The ferroelectric‐to‐ferroelectric phase transition between the high temperature (FERH) and the low temperature (FERL) rhombohedral phases in a Nb‐doped Pb(Zr0.95Ti0.05)O3 ceramic was investigated with transmission electron microscopy (TEM). Both bright field images and electron diffraction patterns were monitored as a function of temperature as well as dc electric field. A special TEM specimen holder that permits the application of electric voltage up to 600 V was employed for the study of electric field‐induced phase transition. It was found that both [1/2](011)c‐ and [1/2](111)c‐type superlattice diffraction spots were present at room temperature when the specimen was under no electric field. The [1/2](111)c‐type superlattice spots were observed to disappear during heating above the phase transition temperature. When dc electric fields were applied at room temperature, the [1/2](111)c‐type superlattice spots vanished as the electric field‐induced FERL → FERH phase transition occurred. Microsc. Res. Tech. 2009. © 2009 Wiley‐Liss, Inc.
Influence of darkness on embryonic diapause termination in dormant Artemia cysts with no experience of desiccation
Authors: Nambu Ziro , Tanaka Shin , Nambu Fumiko , Nakano Masahiro
Published: January 2009

One of the environmental cues for Artemia embryonic diapause termination (EDT), the nature of which is barely understood, is the absence of light, although light–dark cycles (photoperiod) have been examined in inducing embryonic diapause. The influence of constant darkness (DD) on EDT was investigated in laboratory‐produced cysts of Artemia franciscana. In a previous report (Nambu et al., 2008. J Exp Zool 309A:17–24 ), we described a facilitated effect of pretreatment of DD (5–14 days) on EDT in Artemia cysts exposed to a standard rearing condition. In this article, the influence of pretreatment of DD (1–150 days) was investigated in detail by bioassay of hatching. It was found that all the DD conditions significantly promoted EDT. Either the plateau value of the percent hatch increased in response to each DD condition, or the rearing period to attain the half value of the plateau value became shorter. It was also found that DD (1–100 days) led to cyclic changes of EDT: the logistic functions of hatching were cyclically regulated and 30 days‐DD cycles of relative values of their parameters were observed synchronously. The effect of DD‐duration was not cumulative, and a couple of optimum conditions for higher EDT levels were obtained. The probability of Artemia's encountering DD and the possible meaning of cyclic regulation of EDT by DD in Artemia are discussed. J. Exp. Zool. 311A:182–188, 2009. © 2009 Wiley‐Liss, Inc.
Heterochrony in limb evolution: developmental mechanisms and natural selection
Authors: Richardson Michael K. , Gobes Sharon M.H. , van Leeuwen Anne C. , Polman Japke A.E. , Pieau Claude , Sánchez‐Villagra Marcelo R.
Published: January 2009

The tetrapod limb provides several examples of heterochrony—changes in the timing of developmental events. These include species differences in the sequence of skeletal chondrogenesis, in gene transcription in the developing limbs, and in the relative time at which forelimb and hind limb buds develop. Here, we examine (i) phylogenetic trends in limb heterochrony; (ii) changes in developmental mechanisms that may lead to heterochrony; and (iii) the possible role that heterochrony plays in generating adaptive traits. We analyze the published literature and present preliminary data on turtle (Emys orbicularis) and bat (Rousettus amplexicaudatus) limb development. Teleosts, marsupials, and some urodeles show extreme timing differences between forelimb (or pectoral fin) and hind limb (or pelvic fin) development; this heterochrony may, in some cases, be adaptive. Published data on limb chondrogenesis reveal sequence elements that are strongly conserved (possibly owing to constraints); and others that vary between higher taxa (for unknown reasons). We find little evidence that chondrogenic sequences are modified by selection for limb functional traits. There are a few examples of developmental mechanisms that may be modified under heterochrony to produce adaptive changes in the limb (e.g. some cases of hyperphalangy or limb reduction). In conclusion, numerous examples of limb heterochrony have been recorded. However, few cases are obviously adaptive. Indeed, current data and methodologies make it difficult to identify the developmental changes, or selective pressures, that may underlie limb heterochrony. More integrative studies, including studies of heterochrony within populations, are needed to assess the role of timing shifts in limb evolution. J. Exp. Zool. (Mol. Dev. Evol.) 312B:639–664, 2009. © 2009 Wiley‐Liss, Inc.
Forelimb indicators of prey‐size preference in the Felidae
Authors: Meachen‐Samuels Julie , Van Valkenburgh Blaire
Published: January 2009

The forelimbs, along with the crania, are an essential part of the prey‐killing apparatus in cats. Linear morphometrics of the forelimbs were used to determine the morphological differences between felids that specialize on large prey, small prey, or mixed prey. We also compared the scaling of felid forelimbs to those of canids to test whether prey capture strategies affect forelimb scaling. Results suggest that large prey specialists have relatively robust forelimbs when compared with smaller prey specialists. This includes relatively more robust humeri and radii, relatively larger distal ends of the humerus, and relatively larger articular areas of the humerus and radius. Large prey specialists also had relatively longer olecranon processes of the ulna and wider proximal paws. These characters are all important for subduing large prey while the cat positions itself for the killing bite. Small prey specialists have relatively longer distal limb elements for swift prey capture, and mixed prey specialists had intermediate values with relatively more robust metacarpals. Arboreal felids also had more robust limbs. They had relatively longer proximal phalanges for better grip while climbing, and a relatively short brachial index (radius to humerus ratio). Additionally, we found that felids and canids differ in forelimb scaling, which emphasizes the dual use of forelimbs for locomotion and prey capture in felids. This morphometric technique worked well to separate prey‐size preference in felids, but did not work as well to separate locomotor groups, as scansorial and terrestrial felids were not clearly distinguished. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.
Ultrastructural and biochemical seasonal changes in epididymal corpus and cauda of viscacha (Lagostomus maximus maximus)
Authors: Aguilera‐Merlo Claudia , Fogal Teresa , Sator Tirso , Dominguez Susana , Sosa Miguel , Scardapane Luis , Piezzi Ramón
Published: January 2009

The reproductive and adaptative behavior of wild rodents is synchronized primarily by the photoperiod. The viscacha, a South American rodent of nocturnal habits and seasonal reproduction is photoperiod‐dependent and its reproductive behavior is regulated by the retinohypothalamic‐pituitary pineal axis. Adult males exhibit an annual reproductive cycle with periods of maximum gonadal activity (summer‐early autumn) and gonadal regression (winter). The corpus and the cauda, the most sensitive segments of the epididymis to changes induced by the photoperiod, were analyzed using electron microscopy and enzymatic biochemistry. During gonadal regression, principal and clear cells showed signs of involution with respect to the activity period. These were characterized by more irregular nuclei, smaller cytoplasms, large vacuoles, altered mitochondria, and glycogen deposits. All cellular populations of the epididymal epithelium in regression presented abundant lysosome‐like dense bodies during the active period. In addition, we measured the activity of four acid glycosidases in the cauda epididymis along the reproductive cycle. N‐acetyl‐β‐D‐glucosaminidase (NAG), an enzyme that degrades endocytosed substances from the epididymal lumen, increased significantly during gonadal regression relative to the active period. These results demonstrate that the viscacha epididymis exhibits significant ultrastructural and biochemical changes during the reproductive cycle. We demonstrate that during regression, melatonin secretion in viscacha increases. This study shows that the epididymal epithelium is reduced. Thus, we postulate that the changes observed in the epididymis are modulated by pineal melatonin. Despite these changes, the epididymis might maintain a microenvironment suitable for the survival of stored spermatozoa. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.
A novel membrane specialization in the sperm tail of bug insects (heteroptera)
Authors: Mercati David , Giusti Fabiola , Dallai Romano
Published: January 2009

The sperm tail of bug insects has 9 + 9 + 2 flagellar axonemes and two mitochondrial derivatives showing two to three crystalline inclusions in their matrix. During spermiogenesis, the axoneme is surrounded by a membrane cistern which, at sperm maturity, reduces to two short cisterns on the opposite sides of the axoneme adhering to the mitochondrial derivatives. Filamentous bridges connect the intertubular material of the axoneme to these cisterns. Such bridges, which represent a peculiar feature of bug insects, are resistant to detergent treatment, whereas part of the intertubular material and the inner content of microtubular doublets are affected by the treatment. After freeze‐fracture replicas, at the insertion of the bridges to the cisternal membrane, the P‐face of this membrane shows a characteristic ribbon consisting of four rows of 11 ± 1 nm staggered intramembrane particles, 13 ± 2 nm apart along each row. The bridges could be able to maintain the axoneme in the proper position during flagellar beating avoiding distortion affecting sperm motility. J. Morphol. 2009. © 2009 Wiley‐Liss, Inc.
Spurious correlations between recent warming and indices of local economic activity
Authors: Schmidt Gavin A.
Published: January 2009

A series of climate model simulations of the 20th Century are analysed to investigate a number of published correlations between indices of local economic activity and recent global warming. These correlations have been used to support a hypothesis that the observed surface warming record has been contaminated in some way and thus overestimates true global warming. However, the basis of the results are correlations over a very restricted set of locations (predominantly western Europe, Japan and the USA) which project strongly onto naturally occurring patterns of climate variability, or are with fields with significant amounts of spatial auto‐correlation. Across model simulations, the correlations vary widely due to the chaotic weather component in any short‐term record. The reported correlations do not fall outside the simulated distribution, and are probably spurious (i.e. are likely to have arisen from chance alone). Thus, though this study cannot prove that the global temperature record is unbiased, there is no compelling evidence from these correlations of any large‐scale contamination. Copyright © 2009 Royal Meteorological Society
Comparative evaluation of Ca chloride and Ca phosphate for extractable sulfur in soils with a wide range in pH
Authors: Sahrawat Kanwar L. , Murthy K. V. S. , Wani S. P.
Published: January 2009

Deficiency of sulfur (S) is becoming widespread in the rainfed systems of India, and there is increasing need for diagnosing the deficiency. Calcium chloride and Ca phosphate are commonly used for extracting available S in soils. Because of cost and the ease of availability locally, we prefer using Ca chloride as an extractant over Ca phosphate, for extracting available S. However, there is paucity of data on the comparative evaluation of the two extractants to extract available S, especially in soils having a wide range in natural pH (from acidic to alkaline range). It is recognized that soil pH plays a dominant role in the adsorption–desorption and extractability of sulfate‐S in soils. We compared the extraction of S by Ca chloride and Ca phosphate in 86 Indian soils having a wide range in pH (4.5 to 10.6). Sulfur in the extracts was determined by ICP‐AES. Considering all the 86 soil samples tested, there was an excellent agreement between the values of extractable S determined by using the two extractants (r = 0.96, p < 0.001). However, the correlation coefficient (r) between the values of extractable S by the two reagents, although highly significant, varied among the groups of soil samples according to the range in soil pH. The highest correlation coefficient (r = 0.99, p < 0.0001, n = 17) was found for soils with pH in the alkaline range (8.5–10.6), and the lowest correlation coefficient (r = 0.71, p < 0.0001, n = 58) was obtained with a set of soil samples with pH in the acidic range (4.5–6.5). For soil samples having pH in the near‐neutral range (6.7–7.3), an excellent agreement was observed (r = 0.93, p < 0.0001, n =11) between the extractable‐S values obtained by the two extractants. While Ca phosphate extracted higher amount of S compared to Ca chloride in soil samples with pH in the acidic range, the two extractants were equally effective for soil samples with pH in the neutral or alkaline range. Our results suggest that for most of the soils in the semiarid tropical regions, which have pH in the neutral to alkaline range, Ca chloride can replace Ca phosphate as an extractant for removing available S in such soils.
Future Market: Photovoltaic Industry
Authors: Grohe Andreas , Wirth Harry
Published: January 2009

There are numerous possibilities for laser source manufacturers as well as laser equipment manufacturers in the photovoltaic market. On one side there are structuring steps unavoidable in thin film photovoltaic production, incorporating numerous small lasers per module production line. On the other there is a huge variety of possible laser processes in crystalline silicon photovoltaic, where it is only a matter of time until the first laser processes make their way into process sequences for higher efficient solar cells.
To Know How is Still Fundamental
Authors: Brak Philippe
Published: January 2009

The GSI Group Inc. was founded in 1968 as General Scanning, Inc. Since then they changed towards a supplier of lasers, laser systems and precision motion devices. In particular, the acquisition of Excel Technology Inc. in summer 2008 was a major step in this direction. Andreas Thoss spoke for LTJ with Philippe Brak, Vice President and General Manager of Laser Business at GSI, about the acquisition and GSI's future plans.
Macromol. Mater. Eng. 1/2009
Authors: Lewis François , Mantovani Diego
Published: January 2009

Cover: The small punch test was proposed as a new polymer‐metal adhesion test that allows fundamental studies of the adhesion properties of soft nanocoatings for stent applications. The cover picture illustrates the effect of a 25% plastic deformation on thin fluorocarbon films. Further details can be found in the article by F. Lewis and D. Mantovani* on page 11.
Click Polyester: Synthesis of Polyesters Containing Triazole Units in the Main Chain by Click Chemistry and Improved Thermal Property
Authors: Nagao Yu , Takasu Akinori
Published: January 2009

A “click” polymerization of dialkynes that contain an ester linkages and diazides to has been performed to synthesize various polyesters, termed “click polyesters” with a high $\overline M _{\rm n}$ of 1.0 × 104 to 7.0 × 104 in an excellent yield. This polymerization accompanied a formation of 1,4‐disubstituted triazoles in the polyester main chain by a CuI catalyst. The triazole ring formation in the polyester main chain leads to improved thermal properties and enhancement of the even–odd effect of methylene chain length of the produced click polyesters. This report is the first report of the application of click chemistry to synthesize a series of polyesters under mild conditions.

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Mitochondria as targets for cancer therapy
Authors: Ralph Stephen J. , Neuzil Jiri
Published: January 2009

Mitochondria have recently emerged as intriguing targets for anticancer drugs. A variety of compounds have been now identified that act via mitochondria. These compounds, termed mitocans (an acronym for mitochondria and cancer), destabilise mitochondria and cause apoptosis, which is, at least in some cases, selective for cancer cells. Mitochondria are the powerhouse of the cell, providing it with energy, as well as the source of important mediators of apoptosis. Recent findings show that individual types of cancers are complex and can differ considerably in their array of DNA mutations, harbouring different sets of genetic causes. This indicates that it will be very unlikely to cure cancer by drugs targeting only a few gene products or single pathways that are essential for tumour survival. What is needed then is an invariant target, common to all cells, but which is predominantly only affected by drugs when delivered inside the cancer cells. Such targets appear to be mitochondria, with very rare mutations, and mitocans can be expected to be very efficient drugs of choice for a number of different types of the neoplastic disease.
Experience with a Punjabi, Urdu and Hindi rheumatology telephone helpline
Authors: Kumar Kanta , Deeming Alison , Gordon Caroline , Nightingale Peter , Raza Karim
Published: January 2009

Objectives: To investigate what proportion of patients attending a rheumatology unit in Birmingham, UK, require interpretation services and to assess the use of an Asian language telephone helpline we have established for those who find it easier to communicate in Punjabi, Urdu or Hindi than in English.

Methods: Our patients' requirement for interpretation services and their ability to read the script of the language they preferred to communicate in was assessed. A second survey assessed the use of an Asian language helpline we had established. All calls were recorded over 18 months. The reasons for the calls were categorized and compared with those made to our English helpline.

Results: 171 of 512 patients (33%) stated that they required interpretation services. 128 (25%) were not able to read the script of their preferred language. In the second survey, 101 calls to the Asian language helpline were assessed and were compared with calls to the English helpline. The reasons for the calls differed between the helplines.

Conclusions: A large proportion of patients attending our rheumatology unit required interpretation services to communicate effectively with their healthcare professional. Most of these patients were unable to read the script of the language they could speak, casting some doubt over the utility of translated written information. Patients of South Asian origin who preferred to communicate in Punjabi, Urdu or Hindi made use of a helpline operating in these languages, suggesting that this may be an effective strategy to facilitate communication with this group of patients. Copyright © 2009 John Wiley & Sons, Ltd.
Correlation between urodynamic function and 3D cat scan anatomy in neobladders: Does it exist?
Authors: Crivellaro S. , Mami E. , Wald C. , Smith J.J. , Kocjancic E. , Stoffel J. , Bresette J. , Libertino J.A.
Published: January 2009

Introduction

We compared the functional and anatomical differences among three different orthotopic neobladders, utilizing video urodynamics and 3D CT to determine what parameters, if any, correlate to function.

Materials and Methods

Thirty‐four patients were able to participate in the evaluation of their neobladder by 3D CT and video urodynamics. Three different orthotopic neobladders were identified (12 ileal, 7 ileocecal, 15 sigmoid). Multiple measurements, observations and functional data have been obtained. Statistical analysis for this study employed a linear regression test and an odds ratio calculation (using StatSoft V. 5.1).

Results

In comparing three different neobladders, no significant differences were noted. Looking at the entire population, the following association was statistically significant in linear correlation: the maximal capacity and the neobladder volume; the pressure at the maximal capacity and the distance from the symphysis, the pressure at maximal flow and both the distance from the symphysis and the thickness of the neobladder. The distance from the left femoral head was directly correlated with the post void residual and inversely correlated with the maximal flow. The Odds ratio calculation revealed (with significant P < 0.05) that the further the center of the neobladder is from the right femoral head, the higher risk of incontinence.

Conclusions

The study seems to show no significant anatomical or functional difference among the three different types of neobladders. A possible correlation between the position of the neobladder and urinary incontinence is suggested, recognizing further study in a larger population is required. Neurourol. Urodynam. 28:236–240, 2009. © 2009 Wiley‐Liss, Inc.
Assessment of metabolic changes in the striatum of a rat model of parkinsonism: an in vivo1H MRS study
Authors: Kickler N. , Lacombe E. , Chassain C. , Durif F. , Krainik A. , Farion R. , Provent P. , Segebarth C. , Rémy C. , Savasta M.
Published: January 2009

Degeneration of the dopaminergic neurons of the substantia nigra pars compacta in Parkinson's disease induces an abnormal activation of the glutamatergic neurotransmission system within the basal ganglia network and related structures. The aim of this study was to use proton MRS to show metabolic changes in the striatum of 6‐hydroxydopamine‐lesioned rats, a rodent animal model of Parkinson's disease. Animals were examined before and after extensive lesioning of the nigral dopaminergic neurons and after acute administration of L‐3,4‐dihydroxyphenylalanine. No significant alterations in glutamate concentrations, assessed by the MR signal dominated by glutamate with minor contributions from glutamine and γ‐aminobutyric acid, could be measured. The total choline/total creatine ratio was found to be reduced in the striatum of the ipsilateral hemisphere. Copyright © 2008 John Wiley & Sons, Ltd.
Schlagkräftige Physik. Kampfsport
Authors: Mathelitsch Leopold , Thaller Sigrid
Published: January 2009

In vielen Kampfsportarten verhilft ein geschicktes Umsetzen physikalischer Kräfte zum Sieg. Judoka versuchen den Partner zu Fall zu bringen, indem sie mit seiner Bewegung arbeiten. Liegt er auf dem Boden, dann klemmen sie gerne seinen Arm so ein, dass er durch den für ihn ungünstigen Hebel nicht mehr freikommt. Boxen hat das Ziel, den Gegner k.o. zu schlagen. Manche Kopftreffer beschleunigen das Gehirn so erheblich, dass sie Schäden verursachen. Karatekas können tatsächlich ohne Tricks verblüffend dicke Holzbretter und Betonstücke mit der bloßen Hand durchschlagen.
Vom Dunkel zum Licht. Sternentstehung
Authors: Launhardt Ralf , Henning Thomas
Published: January 2009

Sterne entstehen durch den Gravitationskollaps dichter Bereiche innerhalb von Wolken aus molekularem Wasserstoff. Dies geschieht in den Spiralarmen von Galaxien. Dabei spielen die abschirmende Wirkung des interstellaren Staubes sowie Energieabstrahlung durch Moleküllinien eine wichtige Rolle. Beim Akkretionsprozess bilden sich zirkumstellare Scheiben und polare Jets heraus, die Drehimpuls abtransportieren. Die Scheiben sind gleichzeitig die Geburtsstätten von Planetensystemen. In den kommenden Jahren erwarten wir von neuen Beobachtungsinstrumenten wichtige Antworten auf bisher ungelöste Fragen des Sternentstehungsprozesses.
Vermessung einzelner Nanoinseln. Bestimmung von Halbleiterstrukturen mit Röntgenbeugung
Authors: Stangl Julian
Published: January 2009

Röntgenbeugung ist eine gängige Methode in der Materialphysik, um Verzerrungen atomarer Gitter zu bestimmen. Bei inhomogenen Materialien, zum Beispiel Halbleiterbauelementen mit Kontakten, Kanälen etc., ist jedoch eine Analyse oft unmöglich. Der zu wenig fokussierte Strahl erfasst alle unterschiedlichen Strukturen der Probe zugleich. Der Detektor kann also ihre verschiedenen Streusignale nicht mehr trennen. Die hier vorgestellte Methode löst das Problem mit einem “scharfen” Röntgenstrahl, der auf wenige Mikrometer fokussiert ist. Am Beispiel von einzelnen, 3 μm großen Halbleiterinseln wird die Analysemethode erläutert. Sie ermöglicht zudem eine Kombination der Röntgenbeugung mit anderen mikroskopischen Verfahren an derselben Nanostruktur. Damit lassen sich Halbleiter‐Nanostrukturen in Zukunft detailliert analysieren.
Extrasolare Planeten werden sichtbar
Authors: Bührke Thomas
Published: January 2009

Mehr als 300 extrasolare Planeten haben Astronomen in den vergangenen 13 Jahren entdeckt. Bislang ließen sich diese lichtschwachen Sternbegleiter jedoch nur indirekt nachweisen. Kürzlich ist es gleich drei Gruppen gelungen, massearme Begleiter zu fotografieren, bei denen es sich vermutlich um Planeten handelt.
Monolayer and multilayer compact film formations on different substrates by physical deposition
Authors: Wang Xiao‐Lin , He Yan‐Dong , You Li‐Yan , Lu Zhong‐Yuan , Li Ze‐Sheng
Published: January 2009

Dissipative particle dynamics simulations are applied to investigate the monolayer and multilayer film formations on different solid substrates by physical deposition. The influences of the polymer concentration, the polymer chain length, the solvent quality, and the interactions between the polymer solution and the solid substrate surface on the film formation dynamics and the mechanism are studied in detail. The results are analyzed in terms of the thickness and the shape of the deposited film, the kinetics of phase separation in the polymer solution, and the contact angle formed between the polymer aggregations and the substrate surface. Moreover, we suggest two strategies, designing a deposition process analogous to “chemical titration” and physically blocking interlayer diffusion by a simple crosslinked network barrier, to deposit the compact monolayer and multilayer films with better quality, respectively. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 353–365, 2009
Conductivity of crosslinked low surface energy epoxy coatings
Authors: Yuan Ming , Brokken‐Zijp José C. M. , De With Gijsbertus
Published: January 2009

A new and straightforward method has been studied to prepare crosslinked low surface energy semiconductive epoxy coatings. The low surface energy is obtained by adding a small amount of partially fluorinated bifunctional primary amine Jeffamine D230 crosslinker and the conductivity is achieved by adding a small amount of semiconductive nanosized Cobalt(III) phthalocyanine particles. The use of partially fluorinated crosslinker strongly influences the conductivity, the conductive particle network structure, and the network distribution in the coatings. Compared to coatings that are free of fluorine, variations in fractal dimension, percolation threshold, particle‐containing layer thickness, and conductivity level are observed as the amount of fluorinated species is varied. These differences can be explained by (local) differences in effective Hamaker constant, viscosity, curing rate, evaporation of the solvent, and presence or absence of polymer matrix between the particles in the network. Our results suggest that other crosslinked semiconductive low surface energy epoxy coatings can be realized in a similar manner, but careful optimization of processing conditions is required to obtain the desired conductivity levels at low filler concentration. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Chem 47: 366–380, 2009
Molecular orientation and mechanical anisotropy of polypropylene sheet containing N,N′‐dicyclohexyl‐2,6‐naphthalenedicarboxamide
Authors: Uchiyama Yohei , Iwasaki Shohei , Ueoka Chiaki , Fukui Takashi , Okamoto Kenzo , Yamaguchi Masayuki
Published: January 2009

Effect of mixing and processing conditions at T‐die extrusion on the structure and mechanical properties is studied for isotactic polypropylene (PP) containing a small amount of β‐form nucleating agent, N,N′‐dicyclohexyl‐2,6‐naphthalenedicarboxamide. It is found that trigonal β crystals are predominantly formed in the extruded samples containing the nucleating agent irrespective of the mixing and processing conditions, leading to the marked mechanical toughness. On the contrary, the molecular orientation is significantly affected by the mixing and processing conditions. In particular, it should be noted that PP molecules in the extruded sheet which was mixed at high temperature (260 °C) and extruded at low temperature (200 °C) orient perpendicular to the applied flow direction. As a result, the sheet shows anomalous mechanical anisotropy. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 424–433, 2009
Poly(L‐lactide) Substrates with Tailored Surface Chemistry by Plasma Copolymerisation of Acrylic Monomers
Authors: García Cristina González , Ferrus Llorenç Latorre , Moratal David , Pradas Manuel Monleón , Sánchez Manuel Salmerón
Published: January 2009

The wettability of PLLA substrates was modified by plasma copolymerising on its surface thin films based on EA and HEA. The composition of the reactive gas inside the plasma chamber was that of the corresponding liquid mixture of the comonomers. The surface of the substrates was investigated by AFM, which showed that the plasma film was ≈100 nm thick. The WCA decreases monotonically with decreasing HEA content in the mixture. The fraction of hydroxyl groups has been calculated from XPS. The local mechanical properties of the plasma‐polymerised surfaces were estimated by nanoindentation experiments performed using the AFM tip, which turns out to be a method sensitive to the composition of the copolymerised plasma film on the PLLA surface.

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How to make single small holes with large aspect ratios
Authors: Föll Helmut , Gerngroß Mark‐Daniel , Cojocaru Ala , Leisner Malte , Bahr Jörg , Carstensen Jürgen
Published: January 2009

In many areas of research a need for single small holes with diameters from a few nm to several μm and large aspect ratios exists that is hard to meet with existing technologies. In a proof of principle it is shown that suitable single holes or specific arrays of some single holes can be made by first etching a very large number of small and deep holes or pores into semiconductors like Si or InP by established electrochemical means, followed by masking the desired holes and filling all others with, e.g., a metal in a galvanic process. The potential and limitations of this technique is briefly discussed. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Analysis of three graph parameters for random trees
Authors: Banderier Cyril , Kuba Markus , Panholzer Alois
Published: January 2009

We consider three basic graph parameters, the node‐independence number, the path node‐covering number, and the size of the kernel, and study their distributional behavior for an important class of random tree models, namely the class of simply generated trees, which contains, e.g., binary trees, rooted labeled trees, and planted plane trees, as special instances. We can show for simply generated tree families that the mean and the variance of each of the three parameters under consideration behave for a randomly chosen tree of size n asymptotically ∼μn and ∼νn, where the constants μ and ν depend on the tree family and the parameter studied. Furthermore we show for all parameters, suitably normalized, convergence in distribution to a Gaussian distributed random variable. © 2009 Wiley Periodicals, Inc. Random Struct. Alg., 2009
Temperature driven morphological changes of hydrothermally prepared copper oxide nanoparticles
Authors: Neupane Madhav Prasad , Kim Yu Kyoung , Park Il Song , Kim Kyoung A , Lee Min Ho , Bae Tae Sung
Published: January 2009

The size and shape of nanocrystals have a strong effect on the optical, electrical and catalytic properties. Therefore, controlling the size, shape and structure of nanocrystals is technically important. The controlled synthesis of CuO nanostructures was achieved using a hydrothermal process by simply controlling the precipitation reaction temperature between copper nitrate trihydrate and sodium hydroxide. The Scanning Electron Microscopy (SEM), EDS, XRD, and FTIR analysis revealed that the synthesized product at 200 °C is of pure copper oxide particles. From Scherrer formula, the prepared CuO particles varied approximately 3–7 nm in size simply by varying the reaction temperature. The synthesized particles exhibited a regular flake like morphology and had a uniform size distribution. The morphology and size depend on the reaction conditions. Copyright © 2008 John Wiley & Sons, Ltd.
Characterization of bidentate phosphoryl compounds on soil particulates using SIMS
Authors: Groenewold Gary S. , Gresham Gary L. , Avci Recep , Deliorman Muhammedin
Published: January 2009

The presence of organic compounds as surface contaminants on particles can provide valuable data about the particles environment, but identification can be analytically challenging. This is true particularly for compounds that have the potential for strong surface binding, such as compounds capable of multidentate attachment. Direct analysis using time‐of‐flight secondary ion mass spectrometry was evaluated for characterization of soil particles contaminated with low concentrations of two bidentate organophosphoryl compounds, diphenyl‐N,N‐di‐n‐butylcarbamoylmethylphosphine oxide and tetraphenylmethylene diphosphine dioxide. Molecular ions were formed by cationization with H+ and alkali elements Na+ and K+ that are indigenous to the particle surface chemistry. Spectra generated from a contaminated calcareous soil were dominated by K+‐containing ions, whereas spectra from a sandy loam had more abundant Na+‐species. Cation‐bound dimers were also formed which favored incorporation of K+, and a unique aluminosilicate‐phosphoryl conjugate cation was also formed when the diphosphoryl ligand was present on the surface. The phosphoryl ligands also underwent fragmentation reactions, the course of which varied depending on the cation that was bound. Minimum detectable surface concentrations were evaluated and were in the 0.04–0.2 monolayer range, depending on the compound and soil particle matrix they was bound to. The ion signature was detected on soil particle surfaces for time periods exceeding six months, suggesting that the characterization approach could be used for environmental exposure history at times well beyond initial exposure. Copyright © 2009 John Wiley & Sons, Ltd.
Creating and sustaining successful knowledge management in purposeful communities‐summary of key experiences from pioneers
Authors: Albinsson Lars , Curtin Gregory , Forsgren Olov , Wall Maria
Published: January 2009

Based on research organized as a number of workshops, case studies and interviews with experienced practitioners as well as academics, we present in this report the most important findings on how to create and sustain successful knowledge management in a community environment. The cases, workshops and interviews deal specifically with the Microsoft Solutions Sharing Network (SSN) program, but the findings, conclusions and preliminary recommendations can be applied more generally to the development of any knowledge management community. A key conclusion is that the bulk of efforts toward creating successful knowledge management communities focus on less technical, or softer aspects like leadership, culture, social settings and value of participation. However, these are essential, but not sufficient, ingredients for success. Technical issues, issues regarding development and customization of the tools used to facilitate knowledge management (for example, the SSN web portal), and emerging legal issues surrounding the sharing of intellectual property (IP) may be perceived as somewhat less important to the participants, but are nevertheless key factors in the long term success of these communities. It is also concluded that the foundation for successful collaboration is primarily laid in the initial phases of community development. A community must make a positive impression on its participants from the very beginning because most people will not give it a second chance. In this report we have highlighted three important areas to consider when establishing portals for knowledge management: Leadership, Purpose and Process/Infrastructure. A leadership with high credibility in the subject is needed to lead the participants in the right direction, manage the cultural processes and to make sure that relevant content can be found. Initially it is the content that brings people to a specific community. Thus, there has to be some common purpose that not only needs to be in congruence with the professional role of the participants but also be inspiring for them as well. Additionally, the community should have some sort of process that the participants can understand and suits the way they would like to interact. Face‐to‐face meetings and networking activities create trust which is important to get the process started. Language, IT platform, support and rules governing the contribution, creation and sharing of ‘knowledge’ for the community are other concerns that need to be considered within the process. Copyright © 2009 John Wiley & Sons, Ltd.
Geometrische Ersatzimperfektionen für Tragfähigkeitsnachweise zum Biegeknicken von Druckstäben
Authors: Kindmann Rolf , Wolf Christian
Published: January 2009

Im Mittelpunkt des Aufsatzes stehen Untersuchungen zum Biegeknicken von Druckstäben aus gewalzten I‐Profilen. Nach der Klärung des generellen Tragverhaltens werden erforderliche geometrische Ersatzimperfektionen für Stäbe mit Drucknormalkraft und planmäßiger Biegung ermittelt und mit den Werten der aktuellen Regelwerke verglichen. Für Druckstäbe ohne planmäßige Biegung werden für Biegeknicken um die starke Achse geometrische Ersatzimperfektionen angegeben, mit denen sich bis zu 12% höhere Tragfähigkeiten ergeben als bisher (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Untersuchungen über das Trag‐ und Dehnungsverhalten des Betongurtes bei Verbundanschlüssen
Authors: Odenbreit Christoph , Hahn Christoph , Jaspart Jean‐Pierre
Published: January 2009

Aufgrund des steigenden Kostendrucks im Bauwesen ist es besonders wichtig, bereits bei der Planung effiziente Berechnungsmethoden heranzuziehen, die zu einer wirtschaftlichen Bauweise führen. In der Stahl‐ und Verbundbauweise kann dabei die Anwendung der Fließgelenktheorie zu guten Ergebnissen führen, da sowohl Querschnitts‐ als auch Systemreserven nahezu vollständig ausgenutzt werden. Beim gewöhnlichen Verbunddurchlaufträger führt dies zu einer Umlagerung des Stützmomentes hin zum Feld. Diese Umlagerung bedingt eine Zunahme der Rotation im Anschluss. Die hier vorgestellten Versuche zeigen, wie die Art und Menge der Bewehrung Einfluss auf die Rotationskapazität des Verbundanschlusses ausübt. Den erhöhten Rotationsanforderungen von Verbundanschlüssen im Bereiche von Fließgelenken sollte bereits bei der konstruktiven Ausbildung der Anschlüsse Rechnung getragen werden (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Tragverhalten von Schrauben in Scher‐Lochleibungs‐Verbindungen mit ungenau hergestellten Schraubenlöchern
Authors: Hölbling Wolfram , Misiek Thomas , Saal Helmut
Published: January 2009

Unplanmäßige Lagen und Ausführungen der Löcher für Scher‐Lochleibungs‐Verbindungen können sich sowohl auf die Montage des Stahltragwerks als auch auf das Tragverhalten und die Tragfähigkeit desselben nachteilig auswirken. Die Effekte dieser Abweichungen können nur durch die Duktilität der Verbindung, also durch große Formänderungen infolge Lochleibung und/oder Schraubenbiegung ausgeglichen werden. Hierzu stellt sich die Frage, inwieweit die zum Ausgleich der Effekte dieser Abweichungen erforderliche plastische Biegung bei hochfesten Schrauben der Festigkeitsklasse 10.9 oder 8.8 mit großen Durchmessern gegeben ist (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
The external rotation method for reduction of acute anterior shoulder dislocations
Authors: Marinelli Mario , de Palma Luigi
Published: January 2009

Background

Shoulder dislocations account for almost 50% of all joint dislocations, and are most commonly anterior (90–98%) and occur due to trauma. This prospective study was conducted to report our experiences of using the external rotation method (ERM) in the reduction of acute anterior shoulder dislocation.

Materials and methods

Between August 2006 and April 2007, ERM was applied to 31 patients who presented with traumatic anterior shoulder dislocation to the Emergency Department of our Hospital which is a level 2 trauma centre. We evaluated the type of dislocation, the effectiveness of the procedure in achieving reduction, the need for premedication, the ease of performing the reduction, and complications, if any.

Results

Of the 31 patients, 29 had a successful reduction. No premedication was required in 25 patients who had a successful reduction, and the average time required for reduction in 25 was less than 2 min. Only five patients reported severe pain during the process of reduction. The method was not successful in two patients in whom the reduction was achieved under narcosis. We experienced a success rate of 89% at the first attempt. None of the patients encountered any complication.

Conclusions

ERM for the reduction of acute anterior dislocation of the shoulder is a safe and reliable method, mainly without requirement for any sedatives or opiate analgesics, that can be performed relatively painlessly for anterior shoulder dislocations. As no single method has a 100% success rate, ERM is a useful one to know.
Sepiapterin reductase deficiency in a 2‐year‐old girl with incomplete response to treatment during short‐term follow‐up
Authors: Kusmierska K. , Jansen E. E. W. , Jakobs C. , Szymanska K. , Malunowicz E. , Meilei D. , Thony B. , Blau N. , Tryfon J. , Rokicki D. , Pronicka E. , Sykut‐Cegielska J.
Published: January 2009

Sepiapterin reductase (SR) catalyses the last step in the tetrahydrobiopterin biosynthesis pathway; it converts 6‐pyruvoyl‐tetrahydropterin (6‐PTP) to BH4 in an NADPH‐dependent reaction. SR deficiency is a very rare autosomal recessive disorder with normal phenylalanine (Phe) concentration in blood and diagnostic abnormalities are detected in CSF. We present a 16‐month‐old girl with SR deficiency. From the newborn period she presented with an adaptation regulatory disorder. At the age of 3 months, abnormal eye movements with dystonic signs and at 4.5 months psychomotor retardation were noticed. Since that time axial hypotonia with limb spasticity (or rather delayed reflex development), gastro‐oesophageal reflux and fatigue at the end of the day has been observed. Brain MRI was normal; EEG was without epileptiform discharges. Analysis of biogenic amine metabolites in CSF at the age of 16 months showed very low HVA and 5‐HIAA concentrations. Analysis of CSF pterins revealed strongly elevated dihydrobiopterin (BH2), slightly elevated neopterin and elevated sepiapterin levels. Plasma and CSF amino acids concentrations were normal. A phenylalanine loading test showed increased Phe after 1 h, 2 h and 4 h and very high Phe/Tyr ratios. SR deficiency was confirmed in fibroblasts and a novel homozygous g.1330C>G (p.N127K) SPR mutation was identified. On l‐dopa and then additionally 5‐hydroxytryptophan, the girl showed slow but remarkable progress in motor and intellectual ability. Now, at the age of 3 years, she is able to sit; expressive speech is delayed (to 1 1/2 years), passive speech is well developed. Her visual‐motor skills, eye–hand coordination and social development correspond to the age of 2 1/2 years.
Poésie, sciences et politique une génération d'intellectuels italiens (1290-1330)
Authors: Coccia Emanuele , Piron Sylvain
Published: January 2009

Rien n'est plus faux que l'image de Dante comme génie isolé, tranchant sur son époque. Il appartient au contraire à une génération d'intellectuels italiens très caractéristique: laïcs, souvent actifs dans plus d'un domaine, pratiquant abondamment l'expression poétique, engagés dans l'action politique, ces savants-citoyens partagent également une forte conscience historique. Leur inventivité se manifeste, en philosophie, en médecine et en droit, autant que dans l'expression littéraire. Outre des facteurs endogènes, une clé de ce phénomène tient à la réception active du savoir naturaliste élaboré à Paris, qui est lu en Italie hors du contrôle des théologiens. Les parcours parallèles d'une douzaine de personnalité hors du commun montrent la nécessité d'élargir les cadres habituels de l'histoire intellectuelle médiévale.
Communautés de savoirs
Authors: Mews Constant J.
Published: January 2009

L'histoire sociale et institutionnelle de l'université de Paris reste encore souvent détachée de l'étude des dynamiques intellectuelles qui se produisirent en son sein. Le concept des « communautés de savoir » permet de combler ce hiatus, en associant étroitement l'histoire des savoirs à leurs conditions concrètes de production et d'enseignement. Ce modèle permet de rendre attentif au maintien, au sein de l'université parisienne, de diverses «écoles», dotées d'orientations et de programmes de recherche spécifiques. L'apparition des collèges peut être également située dans cette perspective, qui permet de mieux saisir l'interaction entre les enjeux politiques et intellectuels qui scandent l'histoire de l'Université au XIIIesiècle. Au final, il en ressort l'image d'une institution plus fragmentée qu'unifiée.
Assessment of the reproducibility of facial expressions with 3‐D stereophotogrammetry
Authors: Sawyer Adam R. , See Marlene , Nduka Charles
Published: January 2009

OBJECTIVE

There is little research into analyzing whether facial expression changes are secondary to actual treatment or normal day‐to‐day variation. This study aims to ascertain whether nine‐facial expressions were reproducible.

SUBJECTS AND METHODS

Thirty‐nine white subjects performed nine‐facial expressions, captured by three‐dimensional stereophotogrammetry in three sessions. After initial capture (session 1), each expression was repeated after 15 minutes (session 2) and then 4 weeks (session 3) after the initial session. Statistical analysis was performed on the mean variability of facial landmarks between session 1 and 2 and session 1 and 3.

RESULTS

Repose was the most reproducible expression. The least reproducible was “blow‐out‐the‐cheeks.” Analysis between session 1 and 2 showed no significant differences in expression reproducibility. Analysis between session 1 and 3 showed significant differences for the “smile‐with‐lips‐open” and “blow‐out‐the‐cheeks” expressions.

CONCLUSION

Facial expressions are reproducible in a 15‐minute period. There are significant differences in the ability to reproduce facial expressions 4 weeks apart for “smile‐with‐lips‐open” and “blow‐out‐the‐cheeks.”