bluuebunny/crossref_metadata_2025 huggingface dataset:
New insights into cortical interneurons development and classification: Contribution of developmental studies
Authors: Vitalis Tania , Rossier Jean
Published: November 2010

The concerted development of GABAergic interneurons and glutamatergic neurons is a key feature in the construction of the cerebral cortex. In contrast with glutamatergic neurons, GABAergic interneurons are heterogeneous differing by their axonal and dendritic morphologies, biochemical markers, connectivity, and physiology. Furthermore, interneurons have recently been shown to be generated in a variety of telencephalic structures (the ganglionic eminences, the entopeduncular and preoptic areas and the cortex). This review describes the origin, specification and differentiation of interneurons. These recent developmental studies may help to clarify the classification of mature interneurons. In particular recent studies, including our own, provide compelling evidences that most interneurons are specify after their last division in their region of origin before migration. The roles of target tissues in determining the final physiological properties of interneurons are also discussed. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 34–44, 2011
The promise of an interneuron‐based cell therapy for epilepsy
Authors: Sebe Joy Y. , Baraban Scott C.
Published: November 2010

Of the nearly 3 million Americans diagnosed with epilepsy, approximately 30% are unresponsive to current medications. Recent data has shown that early postnatal transplantation of interneuronal precursor cells increases GABAergic inhibition in the host brain and dramatically suppresses seizure activity in epileptic mice. In this review, we will highlight findings from seizure‐prone mice and humans that demonstrate the link between dysfunctional GABAergic inhibition and hyperexcitability. In particular, we will focus on rodent models of temporal lobe epilepsy, the most common and difficult to treat form of the disease, and interneuronopathies, an emerging classification. A wealth of literature showing a causal link between reduced GABA‐mediated inhibition and seizures has directed our efforts to recover the loss of inhibition via transplantation of interneuronal precursors. Numerous related studies have explored the anticonvulsant potential of cell grafts derived from a variety of brain regions, yet the mechanism underlying the effect of such heterogeneous cell transplants is unknown. In discussing our recent findings and placing them in context with what is known about epilepsy, and how related transplant approaches have progressed, we hope to initiate a frank discussion of the best path toward the translation of this approach to patients with intractable forms of epilepsy. © 2010 Wiley Periodicals, Inc. Develop Neurobiol 71: 107–117, 2011
Human CD4+FOXP3+ regulatory T cells produce CXCL8 and recruit neutrophils
Authors: Himmel Megan E. , Crome Sarah Q. , Ivison Sabine , Piccirillo Ciriaco , Steiner Theodore S. , Levings Megan K.
Published: December 2010

One of the defining features of the majority of FOXP3+ Tregs is their inability to produce typical T‐cell‐derived cytokines. Little is known, however, about their capacity to produce chemokines. As Tregs are constitutively present in, and rapidly traffic to, non‐lympoid tissues, we hypothesized that they may produce chemokines to direct the composition of cells that infiltrate inflamed tissues. Surprisingly, we found that Tregs produce high amounts of CXCL8 (IL‐8), a potent neutrophil chemoattractant. Tregs also produced other CC and CXC family chemokines, including CCL2‐5, CCL7, and CXCL10. Whereas ectopic expression of FOXP3 suppressed cytokine production, it significantly induced CXCL8. Moreover, supernatants from Tregs attracted neutrophils via a CXCL8‐dependent mechanism. These data provide the first evidence that although classical Tregs are defined by their lack of proinflammatory cytokine production, they secrete significant quantities of chemokines and thus may have an unappreciated role in directing the recruitment of immune cells.
Synthesis and Redox Behavior of Bis(3‐methylthio‐1‐azulenyl)methyl Cations and Dications Connected by 2‐Thienyl and 2,5‐Thiophenediyl Spacers
Authors: Shoji Taku , Higashi Junya , Ito Shunji , Okujima Tetsuo , Morita Noboru
Published: November 2010

Novel bis(3‐methylthio‐1‐azulenyl)methyl cations 3a+ and 3b+ and dications 4a2+ and 4b2+ were synthesized by thehydride abstraction reaction of the corresponding hydride derivatives 7a, 7b, 8a, and 8b, which were readily prepared by the acid‐catalyzed condensation reaction of 6a and 6b with the corresponding aldehyde and dialdehyde with DDQ. The pKR+ values of novel cations 3a+ and 3b+ and dications 4a2+ and 4b2+ were determined spectrophotometrically to examine the thermodynamic stability of these carbocations. The redox behavior of the mono‐ and dications was also examined by cyclic voltammetry (CV) and differential pulse voltammetry (DPV), which revealed their reversible electrochemical reduction properties, except for the case of dication 4b2+. Moreover, a significant color change was observed by visible spectroscopy under electrochemical reduction conditions. Dications 4a2+ and 4b2+ were also chemically reduced by Zn powder to afford thienoquinoid compounds 9a and 9b, respectively.
Capillary electrophoresis–mass spectrometry for the analysis of intact proteins 2007–2010
Authors: Haselberg Rob , de Jong Gerhardus J. , Somsen Govert W.
Published: November 2010

CE coupled to MS has proven to be a powerful analytical tool for the characterization of intact proteins, as it combines the high separation efficiency of CE with the selectivity of MS. This review provides an overview of the development and application of CE‐MS methods within the field of intact protein analysis as published between January 2007 and June 2010. Ongoing technological developments with respect to CE‐MS interfacing, capillary coatings for CE‐MS, coupling of CIEF with MS and chip‐based CE‐MS are treated. Furthermore, CE‐MS of intact proteins involving ESI, MALDI and ICP ionization is outlined and overviews of the use of the various CE‐MS methods are provided by tables. Representative examples illustrate the applicability of CE‐MS for the characterization of proteins, including glycoproteins, biopharmaceuticals, protein–ligand complexes, biomarkers and dietary proteins. It is concluded that CE‐MS is a valuable technique with high potential for intact protein analysis, providing useful information on protein identity and purity, including modifications and degradation products.
Combined effects of heat and chemical reactions on the peristaltic flow of carreau fluid model in a diverging tube
Authors: Akbar Noreen Sher , Nadeem S.
Published: November 2010

The study of peristaltic flow of a Carreau fluid in a non‐uniform tube under the consideration of long wavelength in the presence of heat and mass transfer is presented. The flow is investigated in a wave frame of reference moving with velocity of the wave c. Two types of analytical solutions have been evaluated (i) perturbation method (ii) homotopy analysis method for velocity, temperature and concentration field. Numerical integration have been used to obtain the graphical results for pressure rise and frictional forces. The effects of various emerging parameters are investigated for five different peristaltic waves. Copyright © 2010 John Wiley & Sons, Ltd.
A family of residual‐based stabilized finite element methods for Stokes flows
Authors: Oñate Eugenio , Nadukandi Prashanth , Idelsohn Sergio R. , García Julio , Felippa Carlos
Published: November 2010

We present a collection of stabilized finite element (FE) methods derived via first‐ and second‐order finite calculus (FIC) procedures. It is shown that several well known existing stabilized FE methods such as the penalty technique, the Galerkin Least Square (GLS) method, the Pressure Gradient Projection (PGP) method and the orthogonal sub‐scales (OSS) method are recovered from the general residual‐based FIC stabilized form. A new family of stabilized Pressure Laplacian Stabilization (PLS) FE methods with consistent nonlinear forms of the stabilization parameters are derived. The distinct feature of the family of PLS methods is that they are residual‐based, i.e. the stabilization terms depend on the discrete residuals of the momentum and/or the incompressibility equations. The advantages and disadvantages of the different stabilization techniques are discussed and several examples of application are presented. Copyright © 2010 John Wiley & Sons, Ltd.
Numerical simulation of the flow in straight blade agitator with the MPS method
Authors: Sun Zhongguo , Liang Yangyang , Xi Guang
Published: November 2010

The three‐dimensional flow in a straight blade agitator with free surface on top is simulated using a grid‐free method named moving particle semi‐implicit method. The agitator has six rotor blades matched with six stationary guide blades. The mechanism and phenomena of the flow are investigated in the area between two adjacent stationary guide blades. Eddies near each tip of the rotational blades are predicted, and they move with the motion of the rotor blades but in opposite rotation direction of the rotor. The rotation axis of the eddies is traced and annular vortices, which are made by the eddies, are studied. The pressure pulsation in the rotation process is also predicted with this particle method. Copyright © 2010 John Wiley & Sons, Ltd.
A multi‐moment transport model on cubed‐sphere grid
Authors: Chen C. G. , Xiao F. , Li X. L. , Yang Y.
Published: November 2010

A conservative, single‐cell‐based semi‐Lagrangian transport model is proposed in this paper. Using multi‐moment concept, an additional moment, i.e. volume‐integrated average (VIA), is treated as the model variable besides the point value (PV) updated in the traditional semi‐Lagrangian schemes. A quadratic interpolation function is constructed based on local degrees of freedom defined within each single cell. The PV moment is advanced by the semi‐Lagrangian formulation, whereas the VIA moment is updated by a finite volume formulation to rigorously ensure the numerical conservation. The numerical fluxes are computed from the PV moments defined along the boundary edges of the control volume. The scheme is extended to the spherical geometry through the application of the cubed‐sphere grid that eliminates the polar singularity in the conventional longitude/latitude coordinates by using the quasi‐uniform grid spacing covering the whole sphere. The single‐cell‐based scheme is well suited for the treatment of the connections between different patches. A simple quasi‐monotone limiter to the PV moment is applied to suppress non‐physical oscillations. The proposed scheme has been validated via representative benchmark tests and the performance is competitive to other existing transport schemes. Copyright © 2010 John Wiley & Sons, Ltd.
The laminar free‐convection boundary‐layer flow about a heated and rotating down‐pointing vertical cone in the presence of a transverse magnetic field
Authors: Dinarvand Saeed
Published: November 2010

This paper deals with the study of the laminar free‐convection boundary‐layer flow about a heated and rotating down‐pointing vertical cone in the presence of a transverse magnetic field. Two cases of heat transfer analysis are discussed. These are: (i) the rotating cone with prescribed surface temperature and (ii) the rotating cone with prescribed surface heat flux. By means of similarity transformation, the governing partial differential equations are reduced into highly non‐linear ordinary differential equations. The resulting non‐linear system has been solved analytically using a very efficient technique, namely homotopy analysis method. Expressions for velocity and temperature fields are developed in a series form. The influence of various pertinent parameters is also seen on the velocity and temperature fields. Copyright © 2010 John Wiley & Sons, Ltd.
Über das Vorkommen von Bufotalinin. Über Krötengifte, 13. Mitteilung
Authors: Schröter H. , Tamm Ch. , Reichstein T. , Deulofeu V.
Published: December 2010

Die papierchromatographische Untersuchung der Sekrete und eines Hautpulvers von 7 Krötenarten wird beschrieben. Ein sehr starker Fleck mit Laufstrecke und Färbung wie Bufotalinin fand sich im Sekret vonBufo regularis Reuss. In dieser und in drei andern Arten konnte auch ein schwacher Fleck festgestellt werden, dessen Laufstrecke und Färbung dem Hellebrigenol entspricht. Falls sich die Anwesenheit dieses Stoffes bestätigen lässt, ist es ein weiteres Beispiel eines Genins, das sowohl in Pflanzen wie in Tieren vorkommt.
Sur la séparation des terres rares à l'aide de l'acide éthylènediamine‐tétraacétique. V. Les diagrammes de solubilité NH4[La‐édta]  NH4[Sm‐édta]  H2O et K[La‐édta]  K[Sm‐édta]  H2O à 0°
Authors: Brunisholz G. , Cahen R.
Published: December 2010

In the system NH4[La‐EDTA]  NH4[Sm‐EDTA]  H2O (EDTA = ethylenediamine tetraacetate), two solid phases appear at 0°: the samarium‐rich mixed crystals NH4[(Sm, La)‐EDTA], 8H2O (= phase α) and the lanthanum‐rich phase β (= NH4[(La, Sm)‐EDTA], n H2O; n=probably3). The solubility diagram shows two saturation curves; an important miscibility gap exists between the two phases. The system belongs to the type IV of theRoozeboomclassification.
Heilmittelchemische Studien in der heterocyclischen Reihe. 20. Mitteilung. Über die Herstellung von 2‐Phenyl‐3‐amino‐pyrazol als Aminokomponente eines langwirkenden Sulfonamids
Authors: Schmidt P. , Druey J.
Published: December 2010

Convenient methods to obtain 2‐phenyl‐3‐amino‐pyrazole, a compound not reported in the literature, are described. The substance is the aminocomponent of a sulfonamide with an outstanding chemotherapeutic effect.
Carotinoidsynthesen XXII. Umsetzungsprodukte des β‐Carotins mit Bromsuccinimid. (Einführung von Äther‐ und Hydroxyl‐Gruppen in den Kohlenwasserstoff)
Authors: Entschel R. , Karrer P.
Published: December 2010

Bei kurzer Einwirkung von Bromsuccinimid auf β‐Carotin in Gegenwart von Alkohol (C2H5OH, CH3OH) und nachfolgender Behandlung des Reaktions‐produktes mit starken Bason (N‐Äthylmorpholin, N‐Äthylpiperidin usw.) bilden sich 4‐Äthoxy‐ und 4,4′‐Diäthoxy‐β‐carotin bzw. 4‐Methoxy‐ und 4,4′‐Dimethoxy‐β‐carotin; ferner 4‐Keto‐4′‐methoxy‐β‐carotin bzw. 4‐Keto‐4′‐äthoxy‐β‐carotin, sowie 4,4′‐Diketo‐β‐carotin und Retro‐dehydro‐carotin.
Beitrag zur Konstitutionsermittlung des Bufotalinins. Krötengift 14. Mitteilung
Authors: Schröter H. , Tamm Ch. , Reichstein T.
Published: December 2010

Tetrahydro‐hellebrigenin (= Tetrahydro‐bufotalidin) gab nach Erhitzen mit Hydrazin und Na‐Äthylat in ca. 50% Ausbeute Tetrahydro‐telocinobufagin.Gleiche Behandlung von 3‐O‐Acetyl‐tetrahydro‐marinobufagin lieferte ein amorphes Gemisch von Neutralstoffen, das im Papierchromatogramm 5 Flecke gab, sowie eine krist. Säure, die als krist. Methylester charakterisiert wurde. Dieselben Produkte wurden in ganz ähnlicher Ausbeute auch beim Erhitzen von 3‐O‐Acetyl‐tetrahydro‐bufotalinin mit Hydrazin und Na‐äthylat erhalten. Dieses Resultat ist eine sehr starke Stütze für die Hypothese, dass Bufotalinin ein 19‐Oxo‐Derivat des Marinobufagins darstellt. Aus dem Verlauf der Rotationsdispersion folgt, dass die Aldehydgruppe sich vermutlich an C–10 befindet, falls Bufotalinin das normale Bufadienolid‐Gerüst enthält, was allerdings noch nicht bewiesen ist.
Cyclic nucleotide phosphodiesterase 7B mRNA: An unfavorable characteristic in chronic lymphocytic leukemia
Authors: Zhang Lingzhi , Murray Fiona , Rassenti Laura Z. , Pu Minya , Kelly Colleen , Kanter Joan R. , Greaves Andrew , Messer Karen , Kipps Thomas J. , Insel Paul A.
Published: November 2010

A cost‐ and time‐efficient means to define the prognosis of patients with chronic lymphocytic leukemia (CLL) is desirable but does not yet exist. On the basis of the evidence that CLL cells have enhanced expression of the cyclic nucleotide phosphodiesterase isoform 7B (PDE7B), we hypothesized that PDE7B expression might provide such information. We assessed PDE7B mRNA expression using quantitative real‐time PCR in peripheral blood mononuclear cells isolated from 85 patients and 30 normal subjects. We compared PDE7B mRNA expression with that of other disease features to determine if its expression correlates with the prognosis of patients with CLL. We found that CLL patients with PDE7B mRNA levels in the top quartile (greater than ninefold elevation relative to normal controls) have a several‐year shorter median time‐to‐treatment (TTT, 36 months) compared to that of patients whose CLL cells express lower levels of PDE7B mRNA (TTT, 77 months, p = 0.001). High PDE7B mRNA expression correlates with expression of zeta‐chain‐associated protein kinase 70 (ZAP‐70), unmutated immunoglobulin heavy chain variable (IGHV) region genes and β2 microglobulin (β2M), but use of a multivariate Cox model revealed that high PDE7B mRNA expression independently predicts a short TTT, even after adjusting for several other disease characteristics (ZAP‐70 or CD38 expression, IGHV mutation status and Rai status). High expression of PDE7B is an unfavorable characteristic in CLL. Assessment of PDE7B mRNA expression thus appears to be a clinically useful biomarker to define the prognosis of patients with CLL.
Nutrient Requirement and Growth of a Synechococcus Species Isolated from Lake Balaton
Authors: Mastala Zoltan , Herodek Sándor , V.‐Balogh Katalin , Borbély György , Shafik Hesham Mohamed , Vörös Lajos
Published: November 2010

A pico sized Synechococcus species isolated from Lake Balaton was studied in batch and continuous cultures. This picocyanobacterium had a pH optimum at 8.5 and a temperature optimum at 28‐30°C. The Ik value for growth was 52 μEinstein m−2 S−1, the maximum growth rate 2.27 d−1, the half saturation Constant of growth 1.2 μg PO4‐P I−1 and the minimal cell quota 1.74 nig P g dry weight−1. The dry weight of cells showed a minimum, the chlorophyll‐a/biomass ratio a maximum as a function of growth rate. Above the quota of 3.4 fg P Cell−1 significant amounts of non‐reactive dissolved Phosphorous were released.
Breakdown of Introduced and Native Leaves in Two Indian Streams
Authors: Raviraja N. S. , Sridhar K. R. , Bärlocher Felix
Published: November 2010

The decomposition of leaves of Ficus benghalensis. Anacardium occidentale. Acacia auriculiformis and Eucalyptus globulus was followed during 16 weeks in two streams in the Western Ghat forest region of Karnataka, India. The concentration of nitrogen increased during decay; the levels of phosphorus, soluble phenolics and calcium decreased. Fungal colonization of the leaves was followed by counting the numbers of conidia released during aeration. Highest conidium production was found on leaves of Ficus: benghalensis. Daily exponential decay coefficients κ where not significantly different between leaf species or streams and varied between −0.0063 and −0,0090. Correlation analyses between κ and initial leaf parameters (N, P, Ca, and phenolics) did not yield any significant values, but there was a significant linear correlation between κ values and log (maximum sporulation rate).
Contribution to the Knowledge of the Monogonont Rotifera of Zanzibar, with a Note on Filinia novaezealandiae Shiel and Sanoamuang, 1993
Authors: Segers Hendrik H. , Koste Walter , Yussuf Sadiq M.
Published: November 2010

No Rotifera have previously been recorded from the Tanzanian island Zanzibar. In the present contribution, 34 monogonont rotifers are recorded from the island. Filinia novaezealandiae is reported for the first time since its description. The morphology of this species is re‐examined using scanning electron microscopy. It is suggested that this may be the true identity of many of the tropical‐latitude records of the cold‐stenothermic Filinia terminalis.
The Influence of Bauxite Tailings on the Cladoceran Populations of Lake Batata, Amazonia, Brazil
Authors: Bozelli Reinaldo Luiz
Published: November 2010

Lake Batata receive tailings from bauxite mining for ten years (1979‐1989). This material, with 7‐9% of solid particles, changed some ecological conditions of part of the lake. In order to study the influence of this material on the cladoceran populations, seasonal and intensive studies were made of abundance and brood size of the animals and of some environmental parameters such as transparency, suspended material, POC (<30pm), total bacteria and chlorophyll a.

Reduced transparency and high suspended matter attested to the greater quantity of tailings in the water column, in the area impacted by tailings. Greater oscillations of density and brood size at stations in the impacted area appear to indicate less stable conditions in this part of the lake.
Distribution of Macrophage Centres in Bream (Abramis brama L.) Liver from the Oder River (Germany/Poland) within the Nature Reserve “Unteres Odertal” Near the Town of Schwedt
Authors: Krüger R. , Pietrock M. , Meinelti Th. , Yoshida T. , Steffens W. , Steinberg Ch.
Published: November 2010

The livers of bream (Abramis brama) from the Oder River near the town of Schwedt (Germany), were investigated for their content of macrophage centres (MCs). The investigations were carried out for a period of 18 months.

The mean MC‐number was 20 ± 14 MCs per mm2 in females and 13 ± 11 MCs per mm2 in males. These values are regarded as normal for adult bream of the Oder River. The diameter of the MCs ranged between 8 and 160 μm for both sexes.

The study showed positive correlations between the MC‐response and water pH as well as water temperature. Different correlations existed between males and females and the water temperature. The use of histological analyses of liver MC‐size and ‐number as a biomarker is discussed. Currently the MC‐response is only regarded as an unspecific biomarker on environmental stress.
Acetyl cedrene and its follower. An Isotopic, NMR and MS Structure elucidation and deuteriation study
Authors: Kamounah Fadhil S. , Christensen Peter , Hansen Poul Erik
Published: November 2010

Acetylation of cedarwood oil (Virginia) leads besides acetyl cedrene also to a minor product, 1,7,7‐trimethyl‐2,3‐(3′,4′‐dimethylbenzo)bicyclo[3.2.1]octane (follower). This product is identified by 2D NMR. Acetylation of cedarwood oil with 13C‐1 labeled acetic acid anhydride leads to a product labeled at the aromatic carbon C‐3′. From the 13C‐labeled compound 13C‐13C coupling constants could be measured.

Acetyl cedrene is conveniently deuteriated by an acid‐catalysed exchange reaction using trifluoroacetic anhydride and D2O. The product is found to be deuteriated both at the acetyl group and at the methyl group at the double bond (carbon 6).

The reaction condition during deuteriation of cedrol leads to the elimination of the hydroxyl group at C‐6 with the formation of α‐cedrene deuteriated at H‐5 and the methyl group at C‐6.

Deuteriation of the follower leads to deuterium exchange at the aromatic carbons C‐5′ and C‐6′. Copyright © 2010 John Wiley & Sons, Ltd.
Nitroaldol reaction of nitro[11C]methane to form 2‐(hydroxymethyl)‐2‐nitro[2‐11C]propane‐1,3‐diol and [11C]Tris
Authors: Kato Koichi , Zhang Ming‐Rong , Minegishi Katsuyuki , Nengaki Nobuki , Takei Makoto , Suzuki Kazutoshi
Published: November 2010

The nitroaldol reaction of nitro[11C]methane and formaldehyde, which yields 2‐(hydroxymethyl)‐2‐nitro[2‐11C]propane‐1,3‐diol, is explored. The fluoride‐ion‐assisted nitroaldol reaction using (C4H9)4NF was rapid and provided the desired nitrotriol in more than 97% radiochemical conversion (decay‐corrected) in 3 min at room temperature. Neither 2‐nitro[2‐11C]ethanol nor 2‐nitro[2‐11C]propane‐1,3‐diol was observed under the reaction conditions. The preparation of 2‐amino‐2‐(hydroxymethyl)‐[2‐11C]propane‐1,3‐diol ([11C]Tris) was described, which was followed by the nitro‐group reduction using NiCl2 and NaBH4 in aqueous MeOH. The decay‐corrected radiochemical conversion to [11C]Tris was 68.0±6.5% in two steps. Copyright © 2010 John Wiley & Sons, Ltd.
An efficient synthesis of carbon‐14‐labeled 6‐[2‐(dimethylamino)ethyl]‐14‐(1‐ethylpropyl)‐5,6,7,8‐tetrahydroindolo [2,1‐α] [2,5]benzodiazocine‐11‐carboxylic acid using Curtius rearrangement reaction as a key step
Authors: Zhang Andy Shiqiang , Ho Jonathan Z. , Braun Matthew P.
Published: November 2010

Here we report an efficient synthesis of 14C‐labeled 6‐[2‐(dimethylamino)ethyl]‐14‐(1‐ethylpropyl)‐5,6,7,8‐tetrahydroindolo‐[2,1‐α][2,5]benzodiazocine‐11‐carboxylic acid (1) using the Curtius rearrangement as a key step. The synthesis was initiated by converting the unlabeled aryl carboxylic acid to an aryl amine via Curtius rearrangement reaction. The resulting aryl amine was then converted to an aryl iodide which was coupled with zinc [14C]cyanide to form an aryl [14C]nitrile. Subsequent hydrolysis yielded the 14C‐labeled carboxylic acid [14C]‐1. This overall process represents a mild and potentially general approach for conversion of unlabeled carboxylic acids to isotopically labeled carboxylic acids. Copyright © 2010 John Wiley & Sons, Ltd.
The periesophageal celom of the articulate brachiopod Hemithyris psittacea (Rhynchonelliformea, Brachiopoda)
Authors: Kuzmina Tatyana V. , Malakhov Vladimir V.
Published: December 2010

The celomic system of the articulate brachiopod Hemithyris psittacea is composed of the perivisceral cavity, the canal system of the lophophore, and the periesophageal celom. We study the microscopic anatomy and ultrastructure of the periesophageal celom using scanning and transmission electron microscopy. The periesophageal celom surrounds the esophagus, is isolated from the perivisceral cavity, and is divided by septa. The lining of the periesophageal celom includes two types of cells, epithelial cells and myoepithelial cells, both are monociliary. Some epithelial cells have long processes extending along the basal lamina, suggesting that these cells might function as podocytes. The myoepithelial cells have basal myofilaments and may be overlapped by the apical processes of the adjacent epithelial cells. The periesophageal celom forms protrusions that penetrate the extracellular matrix (ECM) of the body wall above the mouth and the ECM that surrounds the esophagus. The canals of the esophageal ECM form a complicated system. The celomic lining of the external circumferential canals consists of the epithelial cells and the podocyte‐like cells. The deepest canals lack a lumen; they are filled with the muscle cells surrounded by basal lamina. These branched canals might perform dual functions. First, they increase the surface area and might therefore facilitate ultrafiltration through the podocyte‐like cells. Second, the deepest canals form the thickened muscle wall of the esophagus and could be necessary for antiperistalsis of the gut. J. Morphol., 2011. © 2010 Wiley‐Liss, Inc.
Revealing, identifying and assessing “non‐predictable flaws”, crack type IV, by quantitative acoustic emission non‐destructive inspection technology, photo‐elastic and metallurgical methods
Authors: Muravin G. , Mizrahi I. , Frage N.
Published: November 2010

QAE NDI technology has been adapted to revealing, identifying and assessing one type of previously non‐predictable failure of high energy equipment and piping, known as crack type IV. The research established the following: Cracks of type IV correspond to transverse shear crack mode II, according to the classification used in fracture mechanics and the physics of solids. The length of crack mode II jumps, the velocity of it propagation are significantly higher than in case crack mode I under the same loads. The earliest quantitative statistical Acoustic Emission (AE) indications and peculiarities necessary and sufficient to reveal cracks in specimens loaded by tension or shear loads, especially the differences in the AE power, median Energy, Average Frequency and Hit Rate of the AE signals flow. etc. Based on the findings described above have been formulated requirements and technological solutions for revealing, typifying and assessing crack IV.
Glass sealing materials and laser joining process development for fuel cell stack manufacturing
Authors: Faidel D. , Behr W. , Groß S. , Reisgen U.
Published: November 2010

The fuel cell is increasingly a key position in energy supply of the future. In the Central Technology Division of the Forschungszentrum Jülich technology and manufacturing process concepts are developed for the production of stationary and mobile fuel cell stacks based on the material development of the participating research institutes. Of crucial importance is the use of self developed glass solders as joining and insulation medium. The use of soldering materials has been limited to the furnace technology with small heating and cooling rates. The potential of the laser as a flexible tool for the manufacture and repair of fuel cell stacks invention are to be evaluated as part of a research study. The high power density of laser radiation‐induced heating rates influence the properties of the glass solders and their interaction significantly with metallic materials. First results on applications of different laser sources as joining tool in production of fuel cell invention are shown and explained their application‐related properties.

Die Brennstoffzelle nimmt zunehmend eine Schlüsselposition in der Energieversorgung der Zukunft ein. In der Zentralabteilung Technologie des Forschungszentrums Jülich werden Verfahren und Fertigungskonzepte zur Herstellung stationärer und mobiler Brennstoffzellen‐Stacks auf Basis der Werkstoffentwicklungen der beteiligten Forschungsinstitute entwickelt. Von entscheidender Bedeutung ist hierbei der Einsatz selbstentwickelter Glaslote als Füge‐ und Isolationsmedium. Die Verwendung von Glasloten ist bisher auf die Ofentechnik mit kleinen Aufheiz‐ und Abkühlraten beschränkt. Die Potenziale des Lasers als flexibles Werkzeug für die Fertigung und Reparatur von Brennstoffzellen‐ Stacks sollen im Rahmen einer Forschungsstudie evaluiert werden. Die hohe Leistungsdichte der Laserstrahlung induziert Aufheizraten, die die Eigenschaften der Glaslote und ihre Wechselwirkung mit metallischen Werkstoffen signifikant beeinflussen. Erste Untersuchungsergebnisse zu Einsatzmöglichkeiten unterschiedlicher Laserstrahlquellen als Fügewerkzeug in der Brennstoffzellenfertigung werden dargestellt und ihre anwendungsbezogenen Eigenschaften erläutert.
Characterization and modelling techniques for gas metal arc welding of DP 600 sheet steels
Authors: Mukherjee K. , Prahl U. , Bleck W. , Reisgen U. , Schleser M. , Abdurakhmanov A.
Published: November 2010

The objectives of the present work are to characterize the Gas Metal Arc Welding process of DP 600 sheet steel and to summarize the modelling techniques. The time‐temperature evolution during the welding cycle was measured experimentally and modelled with the softwaretool SimWeld. To model the phase transformations during the welding cycle dilatometer tests were done to quantify the parameters for phase field modelling by MICRESS®. The important input parameters are interface mobility, nucleation density, etc. A contribution was made to include austenite to bainite transformation in MICRESS®. This is useful to predict the microstructure in the fast cooling segments. The phase transformation model is capable to predict the microstructure along the heating and cooling cycles of welding. Tensile tests have shown the evidence of failure at the heat affected zone, which has the ferrite‐tempered martensite microstructure.

Die Ziele der gegenwärtigen Arbeit sind, das Verfahren des Metallschutzgasschweißens von DP 600 Blech‐Stahl zu charakterisieren und die entsprechenden Modellierungstechniken zusammenzufassen. Der Zeit‐Temperaturverlauf während des Schweißzyklus wurde experimentell gemessen und anhand der Simulationssoftware SimWeld modelliert. Um die Phasenumwandlungen während des Schweißzyklus zu modellieren wurden Dilatometrie‐Versuche, für die Quantifizierung der Parameter für die Phasenfeldmodellierung durch MICRESS®, durchgeführt. Die wichtigsten Eingangsparameter sind Grenzschichtmobilität, Keimbildungsdichte etc. Es wurde eine Methode entwickelt, mit der die Transformation von Austenit zu Bainit in MICRESS® überführt werden kann. Dies ist nützlich, um die Mikrostruktur in den schnell abkühlenden Bereichen vorauszusagen. Das Phasenumwandlungsmodell ist in der Lage, die Mikrostruktur entlang der Aufheiz‐ und Abkühlungszyklen des Schweißens abzuschätzen. Zugversuche haben gezeigt, dass das Versagen in der Wärmeeinflusszone, die aus einer ferritisch‐gehärteten martensitischen Mikrostruktur besteht, stattfindet.
Mapping proteoglycan‐bound water in cartilage: Improved specificity of matrix assessment using multiexponential transverse relaxation analysis
Authors: Reiter David A. , Roque Remigio A. , Lin Ping‐Chang , Irrechukwu Onyi , Doty Stephen , Longo Dan L. , Pleshko Nancy , Spencer Richard G.
Published: November 2010

Association of MR parameters with cartilage matrix components remains an area of ongoing investigation. Multiexponential analysis of nonlocalized transverse relaxation data has previously been used to quantify water compartments associated with matrix macromolecules in cartilage. We extend this to mapping the proteoglycan (PG)‐bound water fraction in cartilage, using mature and young bovine nasal cartilage model systems, toward the goal of matrix component‐specific imaging. PG‐bound water fraction from mature and young bovine nasal cartilage was 0.31 ± 0.04 and 0.22 ± 0.06, respectively, in agreement with biochemically derived PG content and PG‐to‐water weight ratios. Fourier transform infrared imaging spectroscopic‐derived PG maps normalized by water content (IR‐PGww) showed spatial correspondence with PG‐bound water fraction maps. Extensive simulation analysis demonstrated that the accuracy and precision of our determination of PG‐bound water fraction was within 2%, which is well‐within the observed tissue differences. Our results demonstrate the feasibility of performing imaging‐based multiexponential analysis of transverse relaxation data to map PG in cartilage. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Statistical noise analysis in GRAPPA using a parametrized noncentral Chi approximation model
Authors: Aja‐Fernández Santiago , Tristán‐Vega Antonio , Hoge W. Scott
Published: November 2010

The characterization of the distribution of noise in the magnitude MR image is a very important problem within image processing algorithms. The Rician noise assumed in single‐coil acquisitions has been the keystone for signal‐to‐noise ratio estimation, image filtering, or diffusion tensor estimation for years. With the advent of parallel protocols such as sensitivity encoding or Generalized Autocalibrated Partially Parallel Acquisitions that allow accelerated acquisitions, this noise model no longer holds. Since Generalized Autocalibrated Partially Parallel Acquisitions reconstructions yield the combination of the squared signals recovered at each receiving coil, noncentral Chi statistics have been previously proposed to model the distribution of noise. However, we prove in this article that this is a weak model due to several artifacts in the acquisition scheme, mainly the correlation existing between the signals obtained at each coil. Alternatively, we propose to model such correlations with a reduction in the number of degrees of freedom of the signal, which translates in an equivalent nonaccelerated system with a minor number of independent receiving coils and, consequently, a lower signal‐to‐noise ratio. With this model, a noncentral Chi distribution can be assumed for all pixels in the image, whose effective number of coils and effective variance of noise can be explicitly computed in a closed form from the Generalized Autocalibrated Partially Parallel Acquisitions interpolation coefficients. Extensive experiments over both synthetic and in vivo data sets have been performed to show the goodness of fit of out model. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Contrast‐enhanced whole‐heart coronary MRI with bolus infusion of gadobenate dimeglumine at 1.5 T
Authors: Hu Peng , Chan Jonathan , Ngo Long H. , Smink Jouke , Goddu Beth , Kissinger Kraig V. , Goepfert Lois , Hauser Thomas H. , Rofsky Neil M. , Manning Warren J. , Nezafat Reza
Published: November 2010

We sought to investigate the T1 kinetics of blood and myocardium after three infusion schemes of gadobenate dimeglumine (Gd‐BOPTA) and subsequently compared contrast‐enhanced whole‐heart coronary MRI after a bolus Gd‐BOPTA infusion with nonenhanced coronary MRI at 1.5 T. Blood and myocardium T1 was measured in seven healthy adults, after each underwent three Gd‐BOPTA infusion schemes (bolus: 0.2 mmol/kg at 2 mL/sec, hybrid: 0.1 mmol/kg at 2 mL/sec followed by 0.1 mmol/kg at 0.1 mL/sec, and slow: 0.2 mmol/kg at 0.3 mL/sec). Fourteen additional subjects underwent contrast‐enhanced coronary MRI with an inversion‐recovery steady‐state free precession sequence after bolus Gd‐BOPTA infusion. Images were compared with nonenhanced T2‐prepared steady‐state free precision whole‐heart coronary MRI in signal‐to‐noise ratio, contrast‐to‐noise ratio, depicted vessel length, vessel sharpness, and subjective image quality. Bolus and slow infusion schemes resulted in similar T1 during coronary MRI, whereas the hybrid infusion method yielded higher T1 values. A bolus infusion of Gd‐BOPTA significantly improved signal‐to‐noise ratio, contrast‐to‐noise ratio, depicted coronary artery length, and subjective image quality, when all segments were collectively compared but not when compared segment by segment. In conclusion, whole‐heart steady‐state free precision coronary MRI at 1.5 T can benefit from a bolus infusion of 0.2 mmol/kg Gd‐BOPTA. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Simple analytical dual‐band spectral‐spatial RF pulses for B1+ and susceptibility artifact reduction in gradient echo MRI
Authors: Yang Cungeng , Deng Weiran , Stenger V. Andrew
Published: November 2010

Susceptibility artifacts and transmission radio frequency (RF) field (B1+) inhomogeneity are major limitations in high‐field gradient echo MRI. Previously proposed numerical 2D spectral‐spatial RF pulses have been shown to be promising for reducing the through‐plane signal loss susceptibility artifact by incorporating a frequency‐dependent through‐plane phase correction. This method has recently been extended to 4D spectral‐spatial RF pulse designs for reducing B1+ inhomogeneity as well as the signal loss. In this manuscript, we present simple analytical pulse designs for constructing 2D and 4D spectral‐spatial RF pulses as an alternative to the numerical approaches. The 2D pulse capable of exciting slices with reduced signal loss and is lipid suppressing. The 4D pulse simultaneously corrects signal loss as well as the B1+ inhomogeneity from a body coil transmitter. The pulses are demonstrated with simulations and with gradient echo phantom and brain images at 3T using a standard RF body coil. The pulses were observed to work well for multiple slices and several volunteers. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Chemie im Schloss
Authors: Bartoll Jens
Published: November 2010

Beim Untersuchen von Farbpigmenten auf Gemälden machen Chemiker manchmal überraschende Entdeckungen.
Wenig Gift — viel Kontakt
Authors: Sisnaiske Julia , Frimat Jean‐Philippe , Hengstler Jan G. , West Jonathan , van Thriel Christoph
Published: November 2010

Nervenzellen vernetzen sich miteinander — es sei denn, Neurotoxine stören sie dabei. Eine neue In‐vitro‐Methode ermittelt, wie schnell Zellfortsätze auf einer Analysenplattform wachsen, und misst so die Neurotoxizität von Chemikalien.
Vater der nuklearen und röntgenspektroskopischen Analytik
Authors: Niese Siegfried
Published: November 2010

Seit dem Jahr 2007 erinnern die GDCh und die ungarische chemische Gesellschaft mit der Hevesy‐Vorlesung an den Naturforscher Georg von Hevesy. Der vor 125 Jahren in Budapest geborene Hevesy hatte ein bewegtes Leben: Politische Gründe zwangen ihn, Ungarn, Deutschland, Dänemark und die von ihm dort eingerichteten Laboratorien zu verlassen.
Daten sammeln und deuten
Authors: Kirsten Guido
Published: November 2010

Verfahren wie das Hochdurchsatzscreening bringen dem Chemiker immer größere Datenmengen. Methoden wie Data Mining mit der Open‐Source‐Software Knime verwandeln die Datenflut in nützliche Informationen und geben Einblicke in Zusammenhänge, die beim sequenziellen Experimentieren kaum zugänglich sind.
Transaktionen im Aufwind
Authors: Schneider Bernd , Kuschel Matthias
Published: November 2010

Im ersten Halbjahr gab es in der chemischen Industrie mehr Zusammenschlüsse und Übernahmen als im gleichen Zeitraum des Jahres zuvor. Deutsche, schweizerische und österreichische Unternehmen litten gleichermaßen unter der Krise.
Fehler beim Zement führten zur Katastrophe
Authors: Fischer Axel
Published: November 2010

Zeit‐ und Kostendruck verursachten die Ölkatastrophe im Golf von Mexiko: Eine falsche Zementmischung und ein schlampiger Einbau der Rohre im Bohrloch waren fatale Fehler, zu denen die BP‐Verantwortlichen auf der Bohrinsel Deepwater Horizon im Golf von Mexiko drängten.
Was riecht, wenn's gebrannt hat?
Authors: Heitmann Katharina , Wichmann Hubertus , Bahadir Müfit
Published: November 2010

”Hier hat es gebrannt!“ Wer kennt nicht diesen typischen Geruch, der nach einem Feuer oder einem Schwelbrand noch lange in den betroffenen Zimmern und Fluren schwebt. Welche chemischen Verbindungen erzeugen diesen charakteristischen Geruch? GC/MS‐Analysen liefern die Antwort.
Ökonomie trifft Ökologie
Authors: Junk Christiane
Published: November 2010

Nach drei Jahren ist es wieder so weit: Die K 2010 findet vom 27. Oktober bis 3. November in Düsseldorf statt. Die Messe der Kunststoff‐ und Kautschukbranche zieht etwa 3000 internationale Aussteller an.
Aufbauen auf diesem Erfolg
Authors: Karger Gerhard
Published: November 2010

2465 Chemiker und Chemikerinnen aus über 60 Ländern trafen sich vom 29. August bis 2. September in Nürnberg, um ihre Wissenschaft als kreative Kraft zu feiern. Der 3rd Euchems Chemistry Congress schreibt die Erfolgsgeschichte fort, die mit den Kongressen in Budapest und Turin begann.
Elegant und nützlich: Biomimetische Synthesestrategien
Authors: Kirsch Stefan , Harschneck Tobias
Published: November 2010

Eleganz und Schönheit, mit der die Natur ihre Naturstoffe aufbaut, dienen Chemikern seit langem als Inspiration. Um komplexe Strukturelemente einfach und schnell zugänglich zu machen, sind biomimetische Schlüsselschritte aus modernen Totalsynthesen nicht mehr wegzudenken.
3. Chinesisch‐Deutsches Symposium ”Frontiers of Chemistry“
Authors: Hecht Stefan
Published: November 2010

Die Gesellschaft Deutscher Chemiker und die Chinese Chemical Society organisierten das dritte gemeinsame Symposium ”Frontiers of Chemistry“ vom 11. bis 15. August in Seeon.
Kuppler unter sich
Authors: Osterath Brigitte , Remenyi Christian
Published: November 2010

Die Entwickler der palladiumkatalysierten C‐C‐Kupplungsmethoden galten stets als heiße Kandidaten für den Chemie‐Nobelpreis. Nun ist es endlich soweit: Richard F. Heck, Ei‐ichi Negishi und Akira Suzuki erhalten die Auszeichnung. Warum die Entscheidung des Nobelpreiskomitees längst überfällig war, und ob es die richtigen Kandidaten getroffen hat, fragten die Nachrichten aus der Chemie Matthias Beller vom Leibniz‐Institut für Katalyse in Rostock.
Increased blood oxygen level‐dependent (BOLD) sensitivity in the mouse somatosensory cortex during electrical forepaw stimulation using a cryogenic radiofrequency probe
Authors: Baltes Christof , Bosshard Simone , Mueggler Thomas , Ratering David , Rudin Markus
Published: November 2010

Functional MRI (fMRI) based on the blood oxygen level‐dependent (BOLD) contrast is widely used in preclinical neuroscience. The small dimensions of rodent brain place high demands on spatial resolution, and hence on the sensitivity of the fMRI experiment. This work investigates the performance of a 400‐MHz cryogenic quadrature transceive radiofrequency probe (CryoProbe) with respect to the enhancement of the BOLD sensitivity. For this purpose, BOLD fMRI experiments were performed in mice during electrical forepaw stimulation using the CryoProbe and a conventional room temperature surface coil of comparable dimensions. Image signal‐to‐noise ratio (SNR) and temporal SNR were evaluated as quality measures for individual images and for fMRI time series of images, resulting in gains (mean ± standard deviation) with factors of 3.1 ± 0.7 and 1.8 ± 1.0 when comparing the CryoProbe and room temperature coil. The CryoProbe thermal shield temperature did not affect the noise characteristics, with temporal noise levels being 63 ± 16% of the corresponding room temperature value. However, a significant effect on BOLD amplitudes was found, which was attributed to temperature‐dependent baseline cerebral blood volumes. Defined local thermal conditions were found to be a critical parameter for achieving an optimal and reproducible fMRI signal. In summary, the CryoProbe represents an attractive alternative for the enhancement of image SNR, temporal SNR and BOLD sensitivity in mouse fMRI experiments. Copyright © 2010 John Wiley & Sons, Ltd.
Changes in the metabolic profile of rat liver after α‐tocopherol deficiency as revealed by metabolomics analysis
Authors: Moazzami Ali A. , Andersson Roger , Kamal‐Eldin Afaf
Published: November 2010

Metabolomics is an approach in which the profiles of metabolites in different tissues and/or biofluids are investigated to understand the changes induced following a modulation. We used this approach to investigate the biochemical effects of α‐tocopherol in the liver using a rat model. Rats (21‐day‐old) were fed either an α‐tocopherol‐sufficient control (n = 10) or an α‐tocopherol‐deficient (n = 10) diet for 2 months before sacrifice. Livers were homogenized in methanol–chloroform–water (3 : 1 : 1, v/v/v), and the polar phase extracts of the liver samples were analyzed using 1H NMR. Multivariate statistical analysis of the data was performed using principal component analysis and orthogonal partial least squares‐discriminant analysis. Identification of 1H NMR signals was performed primarily using the Human Metabolome Database, Biological Magnetic Resonance Data Bank and previous literature, and confirmed by spiking with metabolites and applying two‐dimensional NMR. The statistical analysis revealed that α‐tocopherol deficiency caused an increase in carnitine, choline, L‐valine, L‐lysine, tyrosine and inosine content and a reduction in glucose and uridine 5′‐monophosphate content. Changes in carnitine and glucose suggest a possible shift in energy metabolism. Copyright © 2010 John Wiley & Sons, Ltd.