bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spontaneous segregation on a hybrid chiral surface
Authors: Szabelski Paweł 
Published: February 2008

AbstractSegregation of enantiomers in two‐dimensional adsorbed layers is a process that is usually controlled by anisotropic directional interactions between adsorbed molecules. In this contribution, we propose a simple theoretical model in which the chiral segregation occurs even though the lateral interactions are neglected. In particular, we consider a solid surface composed of two domains with different patterns of active sites being mirror images of each other. The domains of opposite handedness represent crystal facets of a composite chiral material which are adjoined to form a heterochiral adsorbing surface. To explore equilibrium properties of the system, we use Canonical Ensemble Monte Carlo method for a square lattice. The influence of factors such as energetic properties of the surface and density of the adsorbed layer on the extent of separation is examined. The obtained results indicate that effective two‐dimensional separation on the hybrid chiral surface assumed in our model can be achieved only at sufficiently low adsorbate densities. The results also suggest that the segregation on the hybrid surface would be a promising method of enantiodiscrimination for those chiral molecules which do not exhibit strong lateral interactions. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Analysis of similarity/dissimilarity of DNA sequences based on a class of 2D graphical representation
Authors: Yao Yu‐hua , Dai Qi , Nan Xu‐Ying , He Ping‐An , Nie Zuo‐Ming , Zhou Song‐Ping , Zhang Yao‐Zhou 
Published: February 2008

AbstractOn the basis of a class of 2D graphical representations of DNA sequences, sensitivity analysis has been performed, showing the high‐capability of the proposed representations to take into account small modifications of the DNA sequences. And sensitivity analysis also indicates that the absolute differences of the leading eigenvalues of the L/L matrices associated with DNA increase with the increase of the number of the base mutations. Besides, we conclude that the similarity analysis method based on the correlation angles can better eliminate the effects of the lengths of DNA sequences if compared with the method using the Euclidean distances. As application, the examination of similarities/dissimilarities among the coding sequences of the first exon of β‐globin gene of different species has been performed by our method, and the reasonable results verify the validity of our method. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Theoretical study on the structure and formation mechanism of [C6H5Mm]− (MAg, Au; m = 1–3)
Authors: Liu Xiao‐Jing , Yang Chuan‐Lu , Zhang Xiang , Han Ke‐Li , Tang Zi‐Chao 
Published: February 2008

AbstractThe structures and formation mechanisms of the important intermediate phenyl‐coinage metal complexes [C6H5Mm]− (MAg, Au, m = 1–3) are investigated at B3LYP//6‐311G(d, p)/Lanl2dz level using Gaussian 03 program. The adiabatic electron affinity and vertical dissociation energy of [Mm]− and [C6H5Mm]− are calculated, which are excellently coincident with the experimental determination. The C6H5 group bonds on metal clusters through MC σ bond in the complex [C6H5Mm]−. The complexes [C6H5Mm]− (MAg, Au; m = 2–3) are generated through a stepwise reaction. The first step is a direct insertion reaction between [Mm]− (MAg, Au, m = 1–3) and C6H6, which leads to the generation of intermediate [C6H5MmH]− (m = 1–3) with the activation and cleavage of CH bond. The second step is the neutral metal atom abstracting the H atom to yield the product [C6H5Mm]−. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
High‐energy femtosecond fiber lasers based on pulse propagation at normal dispersion
Authors: Wise F.W. , Chong A. , Renninger W.H. 
Published: February 2008

AbstractThe generation and stable propagation of ultrashort optical pulses tend to be limited by accumulation of excessive nonlinear phase shifts. The limitations are particularly challenging in fiber‐based devices, and as a result, short‐pulse fiber lasers have lagged behind bulk solid‐state lasers in performance. This article will review several new modes of pulse formation and propagation in fiber lasers. These modes exist with large normal cavity dispersion, and so are qualitatively distinct from the soliton‐like processes that have been exploited effectively in modern femtosecond lasers but which are also quite limiting. Self‐similar evolution can stabilize high‐energy pulses in fiber lasers, and this leads to order‐of‐magnitude increases in performance: fiber lasers that generate 10 nJ pulses of 100 fs duration are now possible. Pulse‐shaping based on spectral filtering of a phase‐modulated pulse yields similar performance, from lasers that have no intracavity dispersion control. These new modes feature highly‐chirped pulses in the laser cavity, and a theoretical framework offers the possibility of unifying our view of normal‐dispersion femtosecond lasers. Instruments based on these new pulse‐shaping mechanisms offer performance that is comparable to that of solid‐state lasers but with the major practical advantages of fiber.
Behaviour of cellular materials under impact loading
Authors: Vesenjak M. , Ren Z. , Öchsner A. 
Published: February 2008

AbstractThe paper describes experimental and computational testing of regular open‐cell cellular structures behaviour under impact loading. Open‐cell cellular specimens made of aluminium alloy and polymer were experimentally tested under quasi‐static and dynamic compressive loading in order to evaluate the failure conditions and the strain rate sensitivity. Additionally, specimens with viscous fillers have been tested to determine the increase of the energy absorption due to filler effects. The tests have shown that brittle behaviour of the cellular structure due to sudden rupture of intercellular walls observed in quasi‐static and dynamic tests is reduced by introduction of viscous filler, while at the same time the energy absorption is increased.The influence of fluid filler on open‐cell cellular material behaviour under impact loading was further investigated with parametric computational simulations, where fully coupled interaction between the base material and the pore filler was considered. The explicit nonlinear finite element code LS‐DYNA was used for this purpose. Different failure criteria were evaluated to simulate the collapsing of intercellular walls and the failure mechanism of cellular structures in general.The new computational models and presented procedures enable determination of the optimal geometric and material parameters of cellular materials with viscous fillers for individual application demands. For example, the cellular structure stiffness and impact energy absorption through controlled deformation can be easily adapted to improve the efficiency of crash absorbers.
Contact stress analysis on the X‐shape ring
Authors: Lee H.‐S. , Lee Y.‐S. , Chun B.‐S. , Kim S.‐Y. , Baek J.‐H. 
Published: February 2008

AbstractA X‐ring is a loop of elastomer with X‐shaped cross‐section used as a mechanical seal or gasket. Such a X‐ring is designed to be seated in a groove and is compressed during assembly between two or more parts, creating a seal at the interface. The seal is designed to have line contact between the X‐ring and sealing faces. This allows a high local stress, able to contain high pressure, without exceeding the yield stress of the X‐ring shell body. This study aims to detect the contact stress and the deformed shape of a X–shaped ring shell under various compression conditions. For this analysis, four experiments were conducted to obtain material properties of the elastomer. The contact stress analysis is performed by applying material properties that we obtained through experiments. A contact stress analysis is carried out by finite element analysis.
Computational modelling of irregular open‐cell foam behaviour under impact loading
Authors: Borovinšek M. , Ren Z. 
Published: February 2008

AbstractCellular structures represent an important class of engineering materials. Typical representative of such structures are metallic foams, which are being increasingly used in many advanced engineering applications due to their low specific weight, appropriate mechanical properties and excellent energy absorption capacity. For optimal design of cellular structures it is necessary to develop proper computational models for use in computational simulations of their behaviour under impact loading.The paper studies the effects of open‐cell metallic foam irregularity on deformation behaviour and impact energy absorption during impact loading by means of parametric computational simulations, using the lattice‐type modelling of open‐cell material structure. The 3D Voronoi technique is used for the reproduction of real, irregular open‐cell structure of metallic foams. The method uses as a reference a regular mesh structure and utilises an irregularity parameter to reproduce the irregularity of real open‐cell structure. A smoothing technique is introduced to assure proper stability and accuracy of explicit dynamic simulations using the produced lattice models. The effects of the smoothing technique were determined by comparative simulations of smoothed and unsmoothed lattices subjected to dynamic loading.
Lipid hydroperoxides from processed dietary oils enhance growth of hepatocarcinoma cells
Authors: Rohr‐Udilova Nataliya V. , Stolze Klaus , Sagmeister Sandra , Nohl Hans , Schulte‐Hermann Rolf , Grasl‐Kraupp Bettina 
Published: February 2008

AbstractLinoleic acid, one of the major fatty acid in dietary oils, is an important source for hydroperoxides that may be formed in the presence of oxygen during food processing. Oxidized oils are absorbed in the intestine, transported as chylomicrones to the liver, and may affect unaltered hepatic cells as well as the process of hepatocarcinogenesis. We have studied the effects of linoleic acid hydroperoxides (LOOH) on growth and gene expression of cultured human hepatocellular carcinoma cells (HCC‐1.2). The addition of LOOH to the medium of HCC‐1.2 carcinoma cells caused dose‐dependent cell loss and enhanced lactate dehydrogenase (LDH)‐release. Under subtoxic conditions, LOOH induced intracellular hydrogen peroxide production, a decrease of glutathione content, elevated expression of the AP‐1 components c‐fos and c‐jun as well as of the anti‐apoptotic enzyme heme oxygenase 1 (HO‐1). Furthermore, the cells were pushed by LOOH into the cell cycle as indicated by increased proportion of cells in the S‐ or G2/M‐phase. The unoxidized linoleic acid was not active. Application of SnPPIX, a HO‐1 inhibitor, decreased the viability of HCC‐1.2 cells, indicating the protective role of HO‐1 induction. This is the first evidence that lipid hydroperoxides of dietary origin may be an important driving force for carcinogenesis in the liver.
Radical scavenging activity, anti‐bacterial and mutagenic effects of Cocoa bean Maillard Reaction products with degree of roasting
Authors: Summa Carmelina , McCourt Josephine , Cämmerer Bettina , Fiala Annette , Probst Martina , Kun Szillard , Anklam Elke , Wagner Karl‐Heinz 
Published: February 2008

AbstractRaw, pre‐roasted and roasted Cocoa samples were separated into four different molecular weight fractions (> 30, 30–10, 10–5 and < 5 kDa) with ultrafiltration and tested for their antibacterial, mutagenic, as well as their radical‐scavenging effects. Radical‐scavenging effects were tested with electro paramagnetic resonance spectroscopy, anti‐mutagenicity in the Salmonella microsome assay (with and without metabolic activation), and antibacterial effects by incubating the fractions with several strains of Bifidobacteria, Enterobacter and Escherichia, and observing their growth. The radical‐scavenging activity and reducing substance concentrations increased, particularly in the 5–10‐kDa roasted fraction. Chromaticity testing elucidated that the 10–5‐kDa fraction was one of the darkest fractions. The Salmonella microsome assay showed neither mutagenic nor anti‐mutagenic effects in any of the samples at any of the different concentrations applied when using TA98, TA100 and TA102. All fractions reduced the growth of pathogenic bacteria, in particular at the highest concentration of 100 μg/mL; however, the same trends were also observed for Bifidobacteria.
Consumption of Brussels sprouts protects peripheral human lymphocytes against 2‐amino‐1‐methyl‐6‐phenylimidazo[4,5‐b]pyridine (PhIP) and oxidative DNA‐damage: results of a controlled human intervention trial
Authors: Hoelzl Christine , Glatt Hansruedi , Meinl Walter , Sontag Gerhard , Haidinger Gerald , Kundi Michael , Simic Tatjana , Chakraborty Asima , Bichler Julia , Ferk Franziska , Angelis Karel , Nersesyan Armen , Knasmüller Siegfried 
Published: February 2008

AbstractTo find out if the cancer protective effects of Brussels sprouts seen in epidemiological studies are due to protection against DNA‐damage, an intervention trial was conducted in which the impact of vegetable consumption on DNA‐stability was monitored in lymphocytes with the comet assay. After consumption of the sprouts (300 g/p/d, n = 8), a reduction of DNA‐migration (97%) induced by the heterocyclic aromatic amine 2‐amino‐1‐methyl‐6‐phenyl‐imidazo‐[4,5‐b]pyridine (PhIP) was observed whereas no effect was seen with 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]‐indole (Trp‐P‐2). This effect protection may be due to inhibition of sulfotransferase 1A1, which plays a key role in the activation of PhIP. In addition, a decrease of the endogenous formation of oxidized bases was observed and DNA‐damage caused by hydrogen peroxide was significantly (39%) lower after the intervention. These effects could not be explained by induction of antioxidant enzymes glutathione peroxidase and superoxide dismutase, but in vitro experiments indicate that sprouts contain compounds, which act as direct scavengers of reactive oxygen species. Serum vitamin C levels were increased by 37% after sprout consumption but no correlations were seen between prevention of DNA‐damage and individual alterations of the vitamin levels. Our study shows for the first time that sprout consumption leads to inhibition of sulfotransferases in humans and to protection against PhIP and oxidative DNA‐damage.
Pathophysiologie und Diagnose der Obstipation. Therapie mit Bisacodyl, Picosulfat und Prokinetika
Authors: Müller‐Lissner Stefan 
Published: February 2008

AbstractDie Obstipation verlangt wenig Diagnostik, die Rom‐Kriterien erlauben eine sichere Diagnosestellung aufgrund der Anamnese. Eine organische Colonerkrankung manifestiert sich nicht als chronische Obstipation. Eine Koloskopie ist daher entbehrlich, wenn Alarmsymptome fehlen, wiederholte Koloskopien sind unsinnig. Die häufig empfohlenen “allgemeinen Maßnahmen” sind von zweifelhafter Wirksamkeit. Ballaststoffe lohnen immer einen Versuch, sind aber kein Wundermittel und werden von einigen Patienten schlecht vertragen. Die verfügbaren Laxanzien sind wirksam und sicher. Die Auswahl richtet sich nach der Obstipationsform und der individuellen Verträglichkeit und Präferenz. Das günstigste Verhältnis von Wirkung zu Nebenwirkung haben die stimulierenden Laxanzien und das Macrogol.
Phytopharmaka als Laxanzien. Abführmittel auf pflanzlicher Basis
Authors: Melzig Matthias F. 
Published: February 2008

AbstractQuellstoff‐ und Anthranoiddrogen sowie Rizinusöl bzw. daraus hergestellte Zubereitungen sind effizient wirksame Phytotherapeutika, die bei akuter und chronischer Obstipation im Sinne der “evidence‐based medicine” eingesetzt werden können. Nahezu problemlos ist die Verwendung von Quellstoff‐Laxanzien bei habitueller bzw. chronischer Obstipation auch über längere Anwendungszeiten sowie bei Kindern und Schwangeren möglich. Für die Beratungspraxis ist hier unbedingt auf die Aufnahme mit ausreichend Flüssigkeit hinzuweisen. Anthranoid‐haltige Phytotherapeutika und das Rizinusöl eignen sich vorrangig für die Therapie der akuten Obstipation, bei bestimmungsgemäßem Gebrauch und in Abstimmung mit dem behandelnden Arzt ist eine längerfristige Therapie aber möglich. Derzeit gibt es keine Hinweise auf unvertretbare Risiken durch Anwendung dieser Phytotherapeutika. Für Kinder und Schwangere bzw. Stillende sind diese Drogen bzw. Zubereitungen daraus nicht primär zu empfehlen.
Obstipation als Arzneimittel‐Nebenwirkung. Obstipation muss richtig erkannt und behandelt werden
Authors: Kopf Andreas 
Published: February 2008

AbstractEin Fünftel bis ein Viertel der Allgemeinbevölkerung und mehr als drei Viertel der Tumorkranken mit Opioid‐Dauermedikation leiden unter Obstipation. Somatische und funktionale Ursachen sind für die Entstehung von Obstipation verantwortlich. Wenn möglich sollte die Therapie von Obstipation kausal sein, häufig ist aber eine symptomatische Therapie notwendig. Neben Allgemeinmaßnahmen sind Laxanzien die wichtigste Therapieoption. Die Laxanzien werden nach ihren Wirkmechanismen klassifiziert und wurden aufgrund von Expertenmeinungen in ein Stufenschema eingruppiert, das sich in der klinischen Praxis bewährt hat. Während Lactulose das prophylaktisch wirksame Laxans der Wahl bei Nichttumorpatienten ist, ist Macrogol das Prophylaktikum der Wahl beim Tumorkranken mit Opioid‐Dauermedikation. Beim Tumorkranken mit Opioid‐Dauermedikation ist eine Laxanzientherapie zur Obstipationsprophylaxe obligat. Anwendungshinweise für ausgesuchte Laxanzien sind in Tabelle 8 zusammengefasst.
Inside out – das Kennzeichen gestresster Zellen
Authors: Grode Thomas , Kec Martina , Madry Milena , Zündorf Ilse , Dingermann Theo 
Published: February 2008

AbstractDer von Peregrine Pharmaceuticals, Inc. entwickelte Antikörper Bavituximab wird derzeit in verschiedenen klinischen Studien getestet. Falls er dabei die Erwartungen erfüllt, könnte er sich zu einem Blockbuster entwickeln, zum einen in der Therapie verschiedener Tumorerkrankungen, zum anderen bei der Behandlung von Hepatitis‐C‐Patienten, die gleichzeitig mit HIV infiziert sind. Was ist das Besondere an Bavituximab?
Das Ende des therapeutischen Klonens, bevor es begann?
Authors: Winckler Thomas 
Published: February 2008

AbstractSeit Jahren führen wir eine kontroverse Debatte um eine neue Technologie der biomedizinischen Forschung – das Klonen patientenspezifischer Zellen zu therapeutischen Zwecken. In letzter Zeit gibt es in diesem Forschungsfeld aufregende Neuigkeiten.
Resolution of chronic hypoxemia in pediatric sickle cell patients after treatment with hydroxyurea
Authors: Singh Sharon A. , Koumbourlis Anastassios C. , Aygun Banu 
Published: February 2008

AbstractChronic hypoxemia is a common manifestation among patients with sickle cell anemia (SCA) who develop chronic lung disease. We report the beneficial effect of hydroxyurea on chronic hypoxemia in three pediatric patients with SCA and recurrent episodes of acute chest syndrome (ACS). All three patients improved rapidly after they were treated with hydroxyurea despite having additional risk factors for hypoxemia. A prospective trial is warranted to assess whether there is a therapeutic effect from the use of hydroxyurea in pediatric SCA patients with chronic hypoxemia. Pediatr Blood Cancer 2008;50:1258–1260. © 2008 Wiley‐Liss, Inc.
Treatment of high‐risk relapsed Wilms tumor with dose‐intensive chemotherapy, marrow‐ablative chemotherapy, and autologous hematopoietic stem cell support: Experience by the Italian association of pediatric hematology and oncology
Authors: Spreafico Filippo , Bisogno Gianni , Collini Paola , Jenkner Alessandro , Gandola Lorenza , D'Angelo Paolo , Casazza Gabriella , Piva Luigi , Luksch Roberto , Perotti Daniela , Pession Andrea , Fagioli Franca , Dallorso Sandro 
Published: February 2008

AbstractBackgroundWe evaluated an intensified chemotherapy strategy in children with Wilms tumor who relapsed with high‐risk features.ProceduresFrom January 2001 to June 2006, we treated 20 consecutive children with reinduction chemotherapy (using ifosfamide/carboplatin/etoposide in 15/20 cases), with (n = 15) or without (n = 5) subsequent high‐dose chemotherapy and hematopoietic stem cell support, surgery where feasible, and radiation therapy. The median time to relapse was 10 months after nephrectomy. All but two children initially received doxorubicin as first‐line therapy.ResultsAll patients were assessed for outcome: 13 are currently alive, 12 of them in remission a median 25 months since their relapse, one with progressing tumor. The treatment was unsuccessful in eight children: the disease progressed during reinduction in three, and relapsed in five. There was one toxic death. All transplanted patients engrafted to a neutrophil count >0.5 × 103/µl after a median 11 days, and to an unsustained platelet count >25,000/µl after a median of 13 days. Three‐year disease‐free and overall survival rates were 56 ± 12% and 55 ± 13%, respectively. Neither recurrence within 12 months of nephrectomy nor extra‐lung recurrence negatively affected outcome. A survival advantage was demonstrated in patients without disease evidence prior to transplant.ConclusionA disease‐free survival rate nearing 50% is a realistic target in children with high‐risk recurrent Wilms tumor. The benefit of autologous hematopoietic stem cell transplantation for consolidation deserves to be investigated in a randomized, controlled study. Pediatr Blood Cancer 2008;51:23–28. © 2008 Wiley‐Liss, Inc.
Outcome of children less than three years old at diagnosis with non‐metastatic medulloblastoma treated with chemotherapy on the “Head Start” I and II protocols
Authors: Dhall Girish , Grodman Howard , Ji Lingyun , Sands Stephen , Gardner Sharon , Dunkel Ira J. , McCowage Geoffrey B. , Diez Blanca , Allen Jeffrey C. , Gopalan Anjali , Cornelius Albert S. , Termuhlen Amanda , Abromowitch Minnie , Sposto Richard , Finlay Jonathan L. 
Published: February 2008

AbstractPurposeTo determine the survival of infants and young children with non‐metastatic medulloblastoma using intensive myeloablative chemotherapy and autologous hematopoietic progenitor cell rescue (AuHCR).MethodsTwenty‐one children less than 3 years old at diagnosis with non‐metastatic medulloblastoma were enrolled on two identical serial studies, “Head Start” I and “Head Start” II. After surgery, patients received five cycles of induction chemotherapy consisting of vincristine, cisplatin, cyclophosphamide and etoposide. Following induction, all patients underwent myeloablative chemotherapy using carboplatin, thiotepa and etoposide with AuHCR. Irradiation was used only at relapse.ResultsThe 5‐year event‐free (EFS) and overall survival (OS) rates (±SE) for all patients, patients with gross total resection, and patients with residual tumor were 52 ± 11% and 70 ± 10%, 64 ± 13% and 79 ± 11%, and 29 ± 17% and 57 ± 19%, respectively. The 5‐year EFS and OS ( ± SE) for patients with desmoplastic and classical medulloblastoma were 67 ± 16% and 78 ± 14%, and 42 ± 14 and 67 ± 14%, respectively. There were four treatment related deaths. The majority of survivors (71%) avoided irradiation completely. Mean intellectual functioning and quality of life (QoL) for children surviving without irradiation was within average range for a majority of survivors tested.ConclusionThis strategy of brief intensive chemotherapy for young children with non‐metastatic medulloblastoma eliminated the need for craniospinal irradiation 52% of the patients, and may preserve QoL and intellectual functioning. The excellent survival rates are somewhat dampened by high toxic mortality. Pediatr Blood Cancer 2008;50:1169–1175. © 2008 Wiley‐Liss, Inc.