bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral imaging for precise surgical intervention in Hirschsprung's Disease
Authors: Frykman Philip K. , Lindsley Erik H. , Gaon Mark , Farkas Daniel L.
Published: February 2008

We used advanced spectral imaging for intrasurgical decision making in a preclinical study, on a mouse model of Hirschsprung's Disease. Our imaging device sampled areas from normal and abnormal (aganglionic) colon in these animals. Spectral segmentation and classification of the resulting images showed a clear distinction between the normal and aganglionic regions, as confirmed by pathological analysis and use of mutant mice. We developed a simple algorithm that could distinguish normal from aganglionic colon with high spatial resolution and reproducibility, and the following statistics: sensitivity = 97%, specificity = 94%, positive predictive value = 92%, negative predictive value = 98%. These studies showed translational proof of concept that spectral imaging could be used during operations, in real time, to help surgeons precisely distinguish normal from abnormal tissue without requiring traditional biopsy. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Refractory thyrotoxicosis induced by iodinated contrast agents treated with therapeutic plasma exchange. A case report
Authors: Pasimeni G. , Caroli F. , Spriano G. , Antonini M. , Baldelli R. , Appetecchia M.
Published: February 2008

Excess free iodide in the blood (ingested or injected) may cause thyrotoxicosis in patients at risk. Iodinated contrast solutions contain small amounts of free iodide and may be of significance for patients affected by Graves' disease, multinodular goiter or living in areas of iodine deficiency. Herein, we report a 57 elderly woman with a clinical history of multinodular goiter presented with a thyrotoxicosis induced by an iodinate contrast agent used during computed tomography scan. Because of the patient's resistance to conventional antithyroid drugs, she was treated with therapeutic plasma exchange (TPE). TPE is used in the treatment of several immunologic and nonimmunologic disorders. Temporary improvement after TPE in cases with thyrotoxicosis has been reported. In our patient's case, we observed an improvement in the thyroid hormone laboratory values as well as clinical findings. TPE can be an addition treatment when standard therapies for thyrotoxicosis fail providing the clinician with an adjuvant tool for rapid preparation of such a patient for thyroidectomy surgery. J. Clin. Apheresis, 2008. © 2008 Wiley‐Liss, Inc.
Advancing beyond charge analysis using the electronic localization function: Chemically intuitive distribution of electrostatic moments
Authors: Pilmé Julien , Piquemal Jean‐Philip
Published: February 2008

We propose here an evaluation of chemically intuitive distributed electrostatic moments using the topological analysis of the electron localization function (ELF). As this partition of the total charge density provides an accurate representation of the molecular dipole, the distributed electrostatic moments based on the ELF partition (DEMEP) allows computing of local moments located at non atomic centers such as lone pairs, σ bonds and π systems. As the local dipole contribution can be decomposed in polarization and charge transfer components, our results indicate that local dipolar polarization of the lone pairs and chemical reactivity are closely related whereas the charge transfer contribution is the key factor driving the local bond dipole. Results on relevant molecules show that local dipole contributions can be used to rationalize inductive polarization effects in alcohols derivatives and typical hydrogen bond interactions. Moreover, bond quadrupole polarization moments being related to a π character enable to discuss bond multiplicities, and to sort families of molecules according to their bond order. That way, the nature of the CO bond has been revisited for several typical systems by means of the DEMEP analysis which appears also helpful to discuss aromaticity. Special attention has been given to the carbon monoxide molecule, to the CuCO complex and to a weak intramolecular N|‐‐‐CO interaction involved in several biological systems. In this latter case, it is confirmed that the bond formation is mainly linked to the CO bond polarization. Transferability tests show that the approach is suitable for the design of advanced force fields. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
The minimized dead‐end elimination criterion and its application to protein redesign in a hybrid scoring and search algorithm for computing partition functions over molecular ensembles
Authors: Georgiev Ivelin , Lilien Ryan H. , Donald Bruce R.
Published: February 2008

One of the main challenges for protein redesign is the efficient evaluation of a combinatorial number of candidate structures. The modeling of protein flexibility, typically by using a rotamer library of commonly‐observed low‐energy side‐chain conformations, further increases the complexity of the redesign problem. A dominant algorithm for protein redesign is dead‐end elimination (DEE), which prunes the majority of candidate conformations by eliminating rigid rotamers that provably are not part of the global minimum energy conformation (GMEC). The identified GMEC consists of rigid rotamers (i.e., rotamers that have not been energy‐minimized) and is thus referred to as the rigid‐GMEC. As a postprocessing step, the conformations that survive DEE may be energy‐minimized. When energy minimization is performed after pruning with DEE, the combined protein design process becomes heuristic, and is no longer provably accurate: a conformation that is pruned using rigid‐rotamer energies may subsequently minimize to a lower energy than the rigid‐GMEC. That is, the rigid‐GMEC and the conformation with the lowest energy among all energy‐minimized conformations (the minimized‐GMEC) are likely to be different. While the traditional DEE algorithm succeeds in not pruning rotamers that are part of the rigid‐GMEC, it makes no guarantees regarding the identification of the minimized‐GMEC. In this paper we derive a novel, provable, and efficient DEE‐like algorithm, called minimized‐DEE (MinDEE), that guarantees that rotamers belonging to the minimized‐GMEC will not be pruned, while still pruning a combinatorial number of conformations. We show that MinDEE is useful not only in identifying the minimized‐GMEC, but also as a filter in an ensemble‐based scoring and search algorithm for protein redesign that exploits energy‐minimized conformations. We compare our results both to our previous computational predictions of protein designs and to biological activity assays of predicted protein mutants. Our provable and efficient minimized‐DEE algorithm is applicable in protein redesign, protein‐ligand binding prediction, and computer‐aided drug design. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008
Prediction of protein structural class using novel evolutionary collocation‐based sequence representation
Authors: Chen Ke , Kurgan Lukasz A. , Ruan Jishou
Published: February 2008

Knowledge of structural classes is useful in understanding of folding patterns in proteins. Although existing structural class prediction methods applied virtually all state‐of‐the‐art classifiers, many of them use a relatively simple protein sequence representation that often includes amino acid (AA) composition. To this end, we propose a novel sequence representation that incorporates evolutionary information encoded using PSI‐BLAST profile‐based collocation of AA pairs. We used six benchmark datasets and five representative classifiers to quantify and compare the quality of the structural class prediction with the proposed representation. The best, classifier support vector machine achieved 61–96% accuracy on the six datasets. These predictions were comprehensively compared with a wide range of recently proposed methods for prediction of structural classes. Our comprehensive comparison shows superiority of the proposed representation, which results in error rate reductions that range between 14% and 26% when compared with predictions of the best‐performing, previously published classifiers on the considered datasets. The study also shows that, for the benchmark dataset that includes sequences characterized by low identity (i.e., 25%, 30%, and 40%), the prediction accuracies are 20–35% lower than for the other three datasets that include sequences with a higher degree of similarity. In conclusion, the proposed representation is shown to substantially improve the accuracy of the structural class prediction. A web server that implements the presented prediction method is freely available at http://biomine.ece.ualberta.ca/Structural_Class/SCEC.html. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
A novel strategy to determine protein structures using exclusively residual dipolar coupling
Authors: Rathinavelan Thenmalarchelvi , Im Wonpil
Published: February 2008

Recent advances in NMR techniques to measure anisotropic spin interactions such as residual dipolar coupling (RDC) have provided better insights into protein structure as well as dynamics. Exploitation of RDC, however, still remains challenging because its successful application requires a reasonable starting model. Using the singular value decomposition method, we have recently developed an RDC restraint potential to optimally extract orientational information from RDC without the prerequisite of any structural information. In the present study, its efficacy is further illustrated by folding a β‐hairpin and α‐helix of protein G from extended conformations with RDC restraints alone by employing the replica exchange torsion angle molecular dynamics (REX‐TAMD) technique. Subsequently, the entire structure of protein G has been determined accurately using the developed fragment superposition method (FRAGSUM). In FRAGSUM, each overlapping fragments (10 amino acids long) is first folded individually by REX‐TAMD, and then the common amino acids are superimposed to determine the entire structure. Because FRAGSUM does not require any additional information besides RDC, it offers a new strategy for de novo structure determination using exclusively RDC. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Synthesis of the tritiated isotopomers of enzastaurin and its N‐des‐pyridylmethyl metabolite for use in ADME studies
Authors: Wheeler William J. , Clodfelter Dean K.
Published: February 2008

Enzastaurin (3‐(1‐methyl‐1H‐indol‐3‐yl)‐4‐[1‐[1‐(2‐pyridinylmethyl)‐4‐piperidinyl]‐1H‐indol‐3‐yl]‐1H‐pyrrole‐2,5‐dione, 1), an agent with potential utility in the treatment of solid tumors, is currently in phase II clinical trials. Enzastaurin undergoes metabolism in vitro and in vivo to several products of oxidative metabolism, the major one of which is 3‐(1‐methyl‐1H‐indol‐3‐yl)‐4‐(1‐piperidin‐4‐yl‐1H‐indol‐3‐yl)‐1H‐pyrrole‐2,5‐dione (2). In a model study, the attempted synthesis 1‐[2H] by reaction of 1 with deuterium gas in the presence of Ir[(COD)(Cy3P)pyr]PF6 (Crabtree's catalyst) was unsuccessful. Alternatively, it was decided to prepare tritiated 2 as both a final product and the starting material for the tritiation of 1. We have reported herein a route that was developed for use in the preparation of tritium‐labeled 2‐[3H] and its successful conversion to 1‐[3H]. Copyright © 2008 John Wiley & Sons, Ltd.
Investigating attraction compatibility in an East Texas city
Authors: Hunt Michael A. , Crompton John L.
Published: February 2008

The study was undertaken in Tyler, Texas, a city of 83 000 population in which the primary tourism attraction is the Caldwell Zoo. The focus was on the compatibility of ancillary attractions to the zoo and their role in adding to the city's cumulative attraction. A sample of 1559 zoo visitors were surveyed. The results revealed that (i) there was a high degree of compatibility between the zoo and other attractions within the city; (ii) tourism spending by those travelling more than 60 miles was significantly higher than those travelling fewer than 60 miles; (iii) expenditures increased as the number of additional attractions visited increased, but started to decrease when the number of attractions totalled to five or more; and (iv) the number of additional attractions visited decreased as the distance travelled increased. Copyright © 2008 John Wiley & Sons, Ltd.
Inside out: Transforming your leadership culture
Authors: McGuire John B. , Rhodes Gary , Palus Charles J.
Published: February 2008

Any organizational culture holds tremendous power. Culture is a system of closely held beliefs that require certain behaviors and exclude other behaviors. It sets norms on everything in the organization. To change the organizational culture, senior leaders must begin by acknowledging their place in the culture, engaging fully in the work of advancing the leadership culture, and standing up first so that others can follow.
Change factor: Making the case for executive adaptability
Authors: Kantor Stu , Kram Kathy E. , Sala Fabio
Published: February 2008

If the ability to lead and manage change is the great differentiator in today's increasingly fast‐paced business environment, then executives who can adapt to change, rather than simply cope with it, will be the ones who consistently deliver outstanding results. A model to frame adaptability focuses on two dimensions: courage and curiosity. With motivation and opportunities, both can be developed.
All about people: Why leaders need to know the human side of innovation
Authors: Rosenfeld Robert B.
Published: February 2008

Innovation involves more than turning out high‐tech gadgets, and innovators are complex human beings of different backgrounds and all types. Unfortunately, innovation has hit a wall in the workplace because the human component has frequently been neglected. Organizations focus too much on the mechanics of innovation and not enough on the underlying people‐based principles. To promote innovation, leaders must first understand what drives it: people.
Experimental Analysis of the folding force in thin wall extruded cells under quasi‐static in‐plane loading
Authors: Zamani J. , Fakhri A. , Ghamsari A. K.
Published: February 2008

In most of the engineering structures, specially moving ones and generally in structures under dynamic and static loadings, energy absorber systems are implemented for preventing or reducing damages. These systems are employed in all on‐road vehicles, train wagons, airplanes and ships. Energy absorbers are subjected to two forms of in‐plane and out‐of‐plane loadings. In this paper, the effects of geometrical parameters such as thickness and height of structure and mechanical parameters such as yield stress in the cell structure are investigated. The effect of changing boundary conditions on the folding force is also investigated. According to the results, the energy absorbed by the cell, directly relates to the increase in the number of rows; the main reason of this increase is the increase in shared walls. Moreover, doubling the wall thickness has resulted in a 4.7 times higher energy absorption. In addition, the accuracy of different analytical models is compared, and the model with most precise predictions is introduced.
Theoretical and experimental analysis of plastic response of isotropic circular plates subjected to underwater explosion loading
Authors: Ashani J. Z. , Ghamsari A. K.
Published: February 2008

Dynamic response analysis of structures subjected to underwater explosion (UndEx) loading has been always an interesting field of study for ship designers and metal forming specialists. Understanding the deformation and rupture mechanism of simple structures plays an important role in successful designing of a reliable structure under this kind of loading. In this paper, first the major parameters of the UndEx phenomenon (peak overpressure, impulse per unit area, dimensionless damage parameter Φ, etc.) are discussed and determined by means of available experimental relations mostly offered by R. Cole. After that, the maximum deflection of a fully clamped circular plate has been calculated using a theoretical procedure assuming two different conditions: (1) neglecting the effect of strain rate, (2) considering the strain rate sensitivity of the material.

Some experiments have been conducted on 5010 aluminum circular plates, using C4 as explosive. In order to simulate reality, a fixture was designed so that the plates are loaded in air‐backed condition. Plates were fixed on top of the fixture, so the fully clamped condition which was assumed as the boundary condition was achieved. The test specimens were measured, not only their maximum deflection but also their thickness at different radii were determined. The results are compared to experimental‐based predictions offered by Nurick and Rajendran who has conducted similar experiments. The results show reasonable agreement with theoretical predictions, especially when strain rate effects are considered. In addition, two new material constants (D, q) for this special aluminum alloy are introduced.
Investigation on the stiffness and linear error of an air slide table of ultra precision machine in nano‐machining
Authors: Vahdati M. , Shokuhfar A.
Published: February 2008

Ultra precision machines are new generation of machine tools. They produce more accurate pieces in size and tolerance. Various rotational or linear movement mechanisms of these machines have been consisted of two main components; stationery or rail, and moving or slider. They are separated by a pressurized air film to reduce the friction resistance between mating parts. Thus, the relative movement happens through an air film. Two main problems for such systems are stiffness and linear motion errors. These issues will affect product quality. Due to such reason, most steel and iron manufacturers are very much interested to search about their product behavior under conditions of loading them as a thrust or journal bearing.

In order to study stiffness and error characteristics of the movement mechanisms in this research, there have been experimental investigations about their variation behavior, and their relationship with input parameters such as inlet air pressure, applied load. Consequently, the best performance condition was identified. Additionally, the general behavior of errors in linear motion was recognized. Also, optimum conditions were identified in order to have the least errors.
Experimental testing of reinforced concrete slab behaviour under long‐term load
Authors: Radnić J. , Matešan D.
Published: February 2008

The paper presents the results of experimental testing of reinforced concrete rectangular slab under long‐term load and unload. The slab is freely supported at corners. Reinforcement is placed in the bottom and upper zone, different in each direction. The slab was subjected to high long‐term load for a year. Afterwards, it was unloaded. Slab displacements at different points have been monitored throughout the year and a half, as well as concrete and reinforcement strains at several measuring points.
Tensile and high cycle fatigue test of copper thin film
Authors: Park J.‐H. , An J.‐H. , Kim Y.‐J. , Huh Y.‐H. , Lee H.‐J.
Published: February 2008

This paper presents the results of tensile and high cycle fatigue tests for copper thin film. Copper films coated by Sn are often used in various electro devices. Especially, when the film is used in tape carrier package (TCP), the film is repeatedly exposed to mechanical or(and) thermal stresses which results often in the failure of the component. Therefore, to guarantee the reliability of the electrical devices using a film, tensile and fatigue characteristics of the film are important. In this study, to obtain the tensile and fatigue characteristics of the film, the specimen was fabricated by an etching process to make a smooth specimen of 2000 μm width, 8000 μm length and 15.26 μm thickness. The tensile and high cycle fatigue tests were performed with the specimen using the test machine developed by the authors. These specimens had measured values of Young's modulus (72 GPa) and a 0.2 % offset yield and an ultimate strength of 358 MPa and 462 MPa, respectively. A closed‐loop feedback control of the magnetic‐electric actuator allowed load‐controlled fatigue tests with 20 Hz frequency, in ambient environment and at two levels of mean stresses. The fatigue strength coefficient and exponent at 0.5 times of the ultimate tensile strength were 431 MPa and ‐0.0843, respectively. The fatigue strength coefficient and exponent at 0.6 times of the ultimate tensile strength were 371 MPa and ‐0.0923, respectively. The Goodman method is recommended when the fatigue life of thin film with mean stress will be estimated. The fatigue strength coefficient and exponent of copper thin film modified using Goodman method were 910 MPa and ‐0.0896, respectively.
Comparison between RVE and full mesh approaches for the simulation of compression tests on cellular metals
Authors: Oliveira B. F. , Cunda L. A. B. , Öchsner A. , Creus G. J.
Published: February 2008

Metal foams are materials of recent development and application that show interesting combinations of physical and mechanical properties. Many applications are envisaged for such materials, particularly in equipments of passive safety, because of their high capacity of energy absorption under impact conditions. The damage analysis in metallic foams is a complex problem and must be performed in a finite strain context. Considering that compression is the dominant loading in impact situations, a finite deformation simulation including damage effects of a compression test on a cellular metal sample is shown in this work. The main objective of the paper is to compare simulations considering periodic boundary conditions, by means of a representative volume element (RVE) approach, with results obtained using full meshes. It is shown that, when the imposed deformation is high, the use of RVE does not describe in a proper manner the deformation that occurs at the walls of cells. This characteristic of RVE approach results in a too stiff behavior when considering load‐displacement relations. A comparison with experimental results is also presented.
On the vibration analysis of adhesively bonded hollow sphere structures
Authors: Winkler R. , Merkel M. , Öchsner A. , Günter W.
Published: February 2008

Metal hollow sphere structures represent a new material group. Within the design progress classical materials are replaced by these new class when a series of physical / mechanical requirements are touched. Typical requirements are related to strength, stiffness, electrical or thermal conductivity. In this study the vibration behaviour is looked at in detail. The overall objective is a description of the dynamic response by numerical simulation. An extraordinary detailed FEM model would exceed available resources. Therefore a proper model with special descriptions for the hollow spheres, the matrix material and the interconnections has to be defined. This paper provides a proper FEM model. Results are compared with vibrations measured by a laser scanning vibrometer.
Experimental analysis of the flexural properties of sandwich panels with cellular core materials
Authors: Fiedler T. , Öchsner A.
Published: February 2008

This paper addresses the flexural properties of sandwich structures with cellular core materials. Experimental three point bending tests are conducted in order to determine the flexural stiffness and the load‐carrying capacity of these advanced composites. In addition, the significant failure modes after exceeding the load‐carrying capacity are identified. The results of these analyses are compared for sandwich structures containing various core materials. These core materials comprise two aluminium foams, namely M‐Pore® and Alporas®, honeycomb structures and novel metallic hollow sphere structures (MHSS).
Functional analyses of neutrophil‐like differentiated cell lines under a hyperglycemic condition
Authors: Oya‐Ito Tomoko , Naitou Hirotaka , Masuda Shuichi , Kinae Naohide , Ohashi Norio
Published: February 2008

Diabetic patients are prone to severe bacterial infections. The functional alterations of neutrophils by hyperglycemia are thought to be partially responsible for such infections. In this study, we investigated the functional changes of neutrophil‐like differentiated cell lines (dHL‐60, dTHP‐1, and dNB‐4) by treatment with 5.5 mM, 11 mM, or 35 mM of glucose. In dHL‐60 cells, the incubation with high glucose (35 mM) resulted in the enhancement of cell aggregation, the suppression of cellular fragility, the induction of reactive‐oxygen species (ROS) production by phorbol myristate acetate (PMA) stimulation, and the impairment of phagocytosis. In dTHP‐1 cells, the treatment with higher glucose generated the suppression of cellular fragility and extremely impaired phagocytosis (by 35 mM), and induced ROS production due to PMA stimulation (by 11 mM). Furthermore, the higher glucose exposure to dNB‐4 cells enlarged intracellular vacuoles (by 35 mM) and induced ROS production due to PMA stimulation (by 11 mM). Since the ROS generation of those cells was enhanced only after PMA stimulation under the higher glucose conditions, glucose may have a priming effect rather than a triggering effect. These extraordinary sensitivities caused by the higher glucose treatments may reflect the dysfunction or overactivation of neutrophils.
On some versions of the element agglomeration AMGe method
Authors: Lashuk Ilya , Vassilevski Panayot S.
Published: February 2008

The present paper deals with element‐based algebraic multigrid (AMGe) methods that target linear systems of equations coming from finite element discretizations of elliptic partial differential equations. The individual element information (element matrices and element topology) is the main input to construct the AMG hierarchy. We study a number of variants of the spectral agglomerate AMGe method. The core of the algorithms relies on element agglomeration utilizing the element topology (built recursively from fine to coarse levels). The actual selection of the coarse degrees of freedom is based on solving a large number of local eigenvalue problems. Additionally, we investigate strategies for adaptive AMG as well as multigrid cycles that are more expensive than the V‐cycle utilizing simple interpolation matrices and nested conjugate gradient (CG)‐based recursive calls between the levels. The presented algorithms are illustrated with an extensive set of experiments based on a matlab implementation of the methods. Copyright © 2008 John Wiley & Sons, Ltd.
The application of an occupational therapy nutrition education programme for children who are obese
Authors: Munguba Marilene Calderaro , Valdés Maria Teresa Moreno , da Silva Carlos Antonio Bruno
Published: February 2008

The aim of this study was to evaluate an occupational therapy nutrition education programme for children who are obese with the use of two interactive games. A quasi‐experimental study was carried out at a municipal school in Fortaleza, Brazil. A convenient sample of 200 children ages 8–10 years old participated in the study. Data collection comprised a semi‐structured interview, direct and structured observation, and focus group, comparing two interactive games based on the food pyramid (video game and board game) used individually and then combined. Both play activities were efficient in the mediation of nutritional concepts, with a preference for the board game. In the learning strategies, intrinsic motivation and metacognition were analysed. The attention strategy was most applied at the video game. We concluded that both games promoted the learning of nutritional concepts. We confirmed the effectiveness of the simultaneous application of interactive games in an interdisciplinary health environment. It is recommended that a larger sample should be used in evaluating the effectiveness of play and video games in teaching healthy nutrition to children in a school setting. Copyright © 2008 John Wiley & Sons, Ltd.
Vom antiken Purgans zum modernen Laxans. “Qui bene purgat, bene curat!”
Authors: Anagnostou Sabine
Published: February 2008

Die Abführmittel haben in der Menschheitsgeschichte eine uralte Tradition. Schon in Altertum und Antike kannten die Heilkundigen eine Fülle mehr oder minder stark abführend wirkender Drogen wie das Rizinusöl, Tamarinden sowie Euphorbiaceen‐ und Convolvulaceenharze. Die Anthranoiddrogen Aloe, Rhabarber und Senna sind seit Hunderten von Jahren in der Pharmazie als Purganzien bzw. Laxanzien im Gebrauch und bis heute nicht aus unserem Arzneischatz wegzudenken. Nach der Entdeckung Amerikas bereicherten amerikanische Laxanzien wie die Faulbaumrinde, die Jalapenwurzel und Podophyllinum wenigstens zeitweilig die europäische Materia medica. Mit dem Aufkommen der Chemiatrie entdeckten die Heilkundigen zudem zahlreiche Salze wie das noch heute offizinelle Glaubersalz als wirksame Abführmittel. Im Kontext der Entwicklung der Phytochemie mit der Isolation und Identifizierung der wirksamen Inhaltsstoffe wie die verschiedenen Anthranoide verabreichte man bevorzugt Präparate aus den besser dosierbaren Reinsubstanzen. Zugleich entwickelte die Forschung anhand der nun bekannten Strukturen neue, synthetische Arzneistoffe, die industriell produziert werden konnten und bald den Arzneimittelmarkt eroberten. Vertreter dieser Phase sind Substanzen wie Phenolphthalein, Bisadocyl und Natriumpicosulfat. Von jeher zählen die Abführmittel zu den am meisten verwendeten Arzneien. Wenn der Apotheker heute auch kaum noch Laxanzien in seiner Offizin selbst bereitet und erst recht nicht die einst so beliebten Klistiere verabfolgt, ist er bei der fachkundigen, persönlichen Beratung und Abgabe auch dieser Arzneimittelgruppe eine unersetzliche Instanz geblieben.
Laxanzien in der Pädiatrie. Therapie der Obstipation bei Kindern
Authors: Bruhn Claudia
Published: February 2008

Bei körperlich und seelisch gesunden Kindern ist eine Obstipation meist eine vorübergehende Reaktion auf äußere Einflüsse wie Nahrungsumstellung (Übergang vom Stillen zur Breinahrung) oder Ortswechsel (Urlaubsreise), die relativ leicht behandelbar ist. Bei Säuglingen und Kleinkindern sind beispielsweise Suppositorien (CO2‐freisetzend, mit Glycerol oder Sorbitol) eine recht effektive Darreichungsform. Von einer chronischen Obstipation spricht man bei einer Beschwerdedauer von mehr als zwei Monaten. Sie erfordert eine ärztliche Diagnostik, da auch schwerwiegendere Ursachen (Allgemeinerkrankungen wie Hypothyreose, kolorektale Fehlbildungen, psychische Störungen) vorliegen können. Die Therapie umfasst nicht nur Medikamente (1. Wahl Macrogol), sondern auch allgemeine Maßnahmen wie Aufklärung und Beratung der Eltern, Toilettentraining und gegebenenfalls eine Ernährungsumstellung.
Laxanzien: Was ist wichtig bei der Beratung in der Apotheke? Wem empfehle ich welches Laxans?
Authors: Martin Eric
Published: February 2008

Bei der Behandlung einer Obstipation ist die öffentliche Apotheke der wichtigste und in der Mehrzahl der Fälle auch der einzige Ansprechpartner. Daraus erwächst eine große Verantwortung beim Ausschluss von Gegenanzeigen. Die zur Verfügung stehenden Präparate sind bei Beachtung der Anwendungshinweise wirksam und sicher, bedürfen aber stets einer individuellen und ursachenorientierten Auswahl.
Die Ursachen von Krebs
Authors: Zündorf Ilse , Dingermann Theo
Published: February 2008

Inzwischen weiß man sehr viel darüber, was Zellen entarten lässt und zur Krebsentstehung führt. Ein jüngst erschienener, lesenswerter Review‐Artikel fasst dieses Wissen sehr komprimiert zusammen.
All‐trans‐retinoic acid and arsenic trioxide as initial therapy for acute promyelocytic leukemia
Authors: Quezada Gerardo , Kopp Lisa , Estey Elihu , Wells Robert J.
Published: February 2008

Acute promyelocytic leukemia (APL) is a rare subtype of acute myeloid leukemia (AML). Treatment of pediatric APL is based on the combination of all‐trans‐retinoic acid (ATRA), an anthracycline and cytosine arabinoside. Arsenic trioxide (ATO) has been studied in adults with newly diagnosed or relapsed APL with excellent response rates both when used as a single agent or in combination with ATRA or ATRA plus chemotherapy. There is little data on combination therapy with ATRA and ATO in pediatric APL. We present a case of an adolescent male with APL who was treated using ATRA and ATO without conventional chemotherapy agents. Pediatr Blood Cancer 2008;51:133–135. © 2008 Wiley‐Liss, Inc.
Solid‐state blending of poly(ethylene terephthalate) with polystyrene: Extent of compatibilization and its dependence on blend composition
Authors: Schexnaydre Ryan J. , Mitchell Brian S.
Published: February 2008

Polystyrene (PS) and poly(ethylene terephthalate) (PET) were blended together in the solid state via cryogenic mechanical attrition (CMA) and in the melt through conventional twin‐screw extrusion. Consecutive modulated differential scanning calorimetry (MDSC) and thermogravitometric analysis (TGA) investigations allowed for the quantitative estimation of the extent of blend compatibility through the accurate determination of sample composition. The extent of blend compatibility, i.e., the amount of PET calculated to have been removed from the bulk and into interphase entanglements with PS, was found to be higher for milled blends than for extruded blends. This compatibility enhancement was the most pronounced for PET‐rich blends. The other benefits of CMA are more precise compositional homogeneity through intimate mixing and the ability for more amorphous PET chains to be entangled with the amorphous PS phase at the interphase. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Compression hysteresis of fibrous systems
Authors: Stankovic Snezana B.
Published: February 2008

This investigation deals with the compression of fibrous systems with oriented distribution of fibers into yarns, which are incorporated in a particular way into fabrics (by weft knitting technology). The compression phenomenon was investigated from both experimental and theoretical aspects. The knitted fabrics were subjected to successive compression–release cycles. According to the compression–release curves obtained, the viscoelastic response of the fibrous materials was determined. In such a way, the mechanical model based on van Wyk's compression theory was applied successfully to determine the compression hysteresis, although it is considered that the theory does not explain mechanical hysteresis of fiber assembly. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Foam formation from fluorinated polyphosphazenes by liquid CO2 processing
Authors: Steely Lee B. , Li Qixiu , Badding John V. , Allcock Harry R.
Published: February 2008

Three dimensional foams of fluorinated polyphosphazenes were prepared using liquid CO2 to solvate polymer films, which were then expanded by volatilization of liquid CO2 within the polymer matrix. The polymers dissolved in CO2 at 1.5 × 107 Pa (2200 psi) and room temperature. Materials were examined using Raman spectroscopy before and during high pressure CO2 exposure. The solubility in liquid CO2 is attributed to interactions between the solvent and the fluorine atoms in the polymer side groups. Fluoroalkoxy polyphosphazenes are known for their hydrophobicity and fire retardant properties, and these characteristics are retained in the foams. Scanning electron microscopy, water swelling, and preliminary fire retardance tests were conducted to determine the morphology and properties of the foams. These materials are possible candidates for a number of different engineering applications. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Effects of welding procedures on mechanical and morphological properties of hot gas butt welded PE, PP, and PVC sheets
Authors: Balkan Onur , Demirer Halil , Ezdeşir Ayhan , Yıldırım Hüseyin
Published: February 2008

Mechanical and morphological properties of hot gas butt welds on polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) sheets for four different procedures, which are single and double V‐welds with and without a welding shoe, were investigated. Besides, weldabilities of base materials were evaluated by rheological measurements. These revealed that weldabilities of PE and PP sheets were better than that of PVC. Welding energy (Ew), which is transferred onto weld surfaces, was calculated to evaluate weld quality. The results of tensile, impact, and bending tests indicated that the weld strengths of PVC sheets were lower than those of PE and PP sheets. When the welding shoe was used, weld strength increased significantly for each material because of the presence of sufficient welding pressure and the effective heating on surfaces. The best results were attained for the double V‐welds with the welding shoe. Morphology of welded regions was evaluated by polarized light, stereo, and scanning electron microscopy. Polarized light microscopy studies indicated that the heat‐affected zone (HAZ) consisted of welding rod core, molten zone, and deformed spherulitic zone, and the welding interface was indistinguishable from the base material when the welding pressure was enough. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers
Electrical performance evaluation of low‐concentrating non‐imaging photovoltaic concentrator
Authors: Mallick Tapas K , Eames Philip C
Published: February 2008

Second generation prototype photovoltaic facades of reduced costs incorporating devices with optically concentrating elements (PRIDE) incorporate 6 mm wide ‘Saturn’ solar cells at the absorber of the dielectric concentrator. The concentrators were made using injection moulding technique with potential to manufacture in large‐scale applications. Four different concentrator panels have been experimentally verified at outdoors to identify the non‐identical current–voltage (I–V) curves. The I–V curve, fill factor and solar to electrical conversion efficiency of four PRIDE concentrator modules have been evaluated from the 24 manufactured in the ‘IDEOCONTE’ project. The maximum solar to electrical conversion efficiency and the fill factor of the PRIDE concentrator were 9·1 and 70%, respectively. The mismatch loss of the ‘unit concentrators’ has been identified that occurred due to the lack of bonding between the concentrator unit and the solar cell and the rear glass. The average power concentration ratio of PRIDE concentrators manufactured by the improved method was 2·10 compared to a similar non‐concentrating panel and the optical efficiency of the PRIDE system was 83%. Copyright © 2008 John Wiley & Sons, Ltd.
A decremental PEEP trial for determining open‐lung PEEP in a rabbit model of acute lung injury
Authors: Hua Yi‐Ming , Lien Shao‐Hung , Liu Tao‐Yuan , Lee Chuen‐Ming , Yuh Yeong‐Seng
Published: February 2008

A positive end‐expiratory pressure (PEEP) above the lower inflection point (LIP) of the pressure–volume curve has been thought necessary to maintain recruited lung volume in acute lung injury (ALI). We used a strategy to identify the level of open‐lung PEEP (OLP) by detecting the maximum tidal compliance during a decremental PEEP trial (DPT). We performed a randomized controlled study to compare the effect of the OLP to PEEP above LIP and zero PEEP on pulmonary mechanics, gas exchange, hemodynamic change, and lung injury in 26 rabbits with ALI. After recruitment maneuver, the lavage‐injured rabbits received DPTs to identify the OLP. Animals were randomized to receive volume controlled ventilation with either: (a) PEEP = 0 cm H2O (ZEEP); (b) PEEP = 2 cm H2O above OLP (OLP + 2); or (c) PEEP = 2 cm H2O above LIP (LIP + 2). Peak inspiratory pressure and mean airway pressure were recorded and arterial blood gases were analyzed every 30 min. Mean blood pressure and heart rate were monitored continuously. Lung injury severity was assessed by lung wet/dry weight ratio. Animals in OLP + 2 group had less lung injury as well as relatively better compliance, more stable pH, and less hypercapnia compared to the LIP + 2 and ZEEP groups. We concluded that setting PEEP according to the OLP identified by DPTs is an effective method to attenuate lung injury. This strategy could be used as an indicator for optimal PEEP. The approach is simple and noninvasive and may be of clinical interest. Pediatr Pulmonol. 2008; 43:371–380. © 2008 Wiley‐Liss, Inc.
Glyphosate applied at low doses can stimulate plant growth
Authors: Velini Edivaldo D , Alves Elza , Godoy Maria C , Meschede Dana K , Souza Reginaldo T , Duke Stephen O
Published: February 2008

BACKGROUND:Glyphosate blocks the shikimic acid pathway, inhibiting the production of aromatic amino acids and several secondary compounds derived from these amino acids. Non‐target plants can be exposed to low doses of glyphosate by herbicide drift of spray droplets and contact with treated weeds. Previous studies have reported that low doses of glyphosate stimulate growth, although these data are very limited. The objective of this study was to determine the effects of low glyphosate doses on growth of a range of plant species.

RESULTS:Growth of maize, conventional soybean, Eucalyptus grandis Hill ex Maiden, Pinus caribea L. and Commelia benghalensis L. was enhanced by 1.8–36 g glyphosate ha−1. Growth of glyphosate‐resistant soybean was unaffected by any glyphosate dose from 1.8 to 720 g AE ha−1. The optimum doses for growth stimulation were distinct for plant species and tissue evaluated. The greatest stimulation of growth was observed for C. benghalensis and P. caribea. Shikimic acid levels in tissues of glyphosate‐treated soybean and maize were measured and found to be elevated at growth‐stimulating doses.

CONCLUSION:Subtoxic doses of glyphosate stimulate the growth of a range of plant species, as measured in several plant organs. This hormesis effect is likely to be related to the molecular target of glyphosate, since the effect was not seen in glyphosate‐resistant plants, and shikimate levels were enhanced in plants with stimulated growth. Copyright © 2008 Society of Chemical Industry
Pentacene devices: Molecular structure, charge transport and photo response
Authors: Nickel Bert , Fiebig Matthias , Schiefer Stefan , Göllner Martin , Huth Martin , Erlen Christoph , Lugli Paolo
Published: February 2008

In this feature article, we will discuss to which extend the peculiar growth properties of pentacene on metallic contacts and on gate dielectrics contribute to the device performance of organic thin film transistors. The early growth state of pentacene monolayers is reviewed, as well as the molecular structure of the so called thin film phase. Then, the relation of structural defect densities to trap densities is discussed. The spatially resolved photo response of a pentacene transistor will be presented in the context of injection barriers and contact homogeneity. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characteristics and mechanisms of hysteresis in polymer field‐effect transistors
Authors: Paasch G. , Scheinert S. , Herasimovich A. , Hörselmann I. , Lindner Th.
Published: February 2008

Hysteresis effects do occur usually in polymer field‐effect devices. It has been suggested that trap recharging or mobile ions, or formation/dissociation of bipolarons (BP) in the accumulation layer can cause this effect. Here, at first a literature survey on the hysteresis in field‐effect transistors is given. Then examples of measured hysteresis in field‐effect transistors and in metal‐insulator‐semiconductor (MIS) capacitors are presented. The typical peculiarity is the dependency of the flat band voltage on the sweep direction of the gate voltage. Our recent numerical simulations on the trap recharging mechanism in MIS capacitors are continued and extended to transistors. Energetically distributed traps can lead to hysteresis. But the form of the hysteresis deviates from the observed one and extreme parameter values are needed. Thus it is more likely that trap recharging can modify a hysteresis caused by another mechanism. For discussing the bipolaron mechanism the equilibrium between polarons and doubly charged states of the polymer chains was analyzed anew. With a rate constant for the bipolaron formation determined recently by Salleo and Street relaxation times for formation/dissociation are determined. They indicate that these processes can cause the hysteresis. A further possible mechanism influencing the hysteresis is connected with complexes between polarons, bipolarons and mobile counter ions. The estimated rate constants indicate processes on the time scale of the measurements. Numerical simulations of these processes as well as of the role of mobile ions and their reactions are required for a full description of the hysteresis. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel organic semiconductors and processing techniques for organic field‐effect transistors
Authors: Tsao H. N. , Räder H. J. , Pisula W. , Rouhanipour A. , Müllen K.
Published: February 2008

The performance of organic field‐effect transistors (FETs) is dictated by the active material employed in such devices. The tendency of the molecules to self‐assemble into highly ordered structures greatly influences charge carrier transport. Also, with the ultimate goal to realize easily produced, cheap and large area electronics, solution processing is crucial. In this aspect, we synthesized dodecyl substituted hexa‐peri ‐hexabenzocoronene HBC‐C12 which is a soluble disk‐shaped molecule with the tendency to pack into columnar stacks. We devised a zone‐casting technique that uniaxially aligned these molecules, enabling the solution processing of macroscopically ordered semiconducting layers, resulting in an improvement of the charge carrier mobility of up to two orders of magnitude compared to non‐oriented films. Furthermore, a donor‐acceptor copolymer was deposited from solution, giving a charge carrier mobility of µsat = 0.17 cm2/Vs even though no macroscopic order could be observed. This is surprising since any disorder acts as trapping sites and inhibits charge carrier transport. We explain this phenomenon by a close π‐stacking distance of the backbones. Finally, giant graphene molecules were successfully deposited via a novel soft‐landing technique, allowing the processing of insoluble molecules into highly oriented and pure thin films. This is a promising way for achieving high performance FETs. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Molecular beam deposition and characterization of thin organic films on metals for applications in organic electronics
Authors: Witte G. , Wöll Ch.
Published: February 2008

The deposition of organic thin films on metal substrates using molecular beam deposition will be reviewed with a special emphasis on molecules which exhibit high charge carrier mobilities and are thus suited to be used as organic semiconductors (OSCs), namely pentacene, rubrene and perylene. Special emphasis will be on aspects of organic molecular beam deposition (OMBD) relevant for the device performance in organic field effect transistors (OFETs), in particular with regard to avoiding or minimizing structural defects at support/OSC interfaces. In addition, another aspect governing – and often limiting – charge injection at electrodes into an OSC, electronic level alignment at molecule/metal interfaces, will be discussed in the context of recent accurate ab‐initio electronic structure calculations. Finally, we will present a novel experimental approach to determine charge transport properties of defect‐free, nm‐sized OSCs where extrinsic contributions to e.g. charge carrier mobilities can be strictly excluded, thus opening the way towards the determination of true intrinsic OSC properties. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)