bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seilnetze – Eigenschaften, Besonderheiten bei der Montage, Lastabtragung
Authors: Ströbel Dieter , Singer Peter , Oswald Rudi 
Published: April 2007

AbstractSeilnetze besitzen eine große Flexibilität im Bauen von dreidimensionalen Flächen. Die Vorteile von Seilnetzen aus Stahl sind, dass die Stahlseile einen großen Widerstand gegen Beschädigung und mutwillige Zerstörung besitzen, aufgrund des hohen Anprallwiderstandes als Absturzsicherung oder Absperrung dienen und eine sehr große Transparenz aufweisen. Mit Seilnetzen werden heute weltweit Geländerausfachungen, Absturzsicherungen an Bauten, Fassaden, Tiergehege und Gartenmöbel gebaut. Die Seilnetze finden für die Innenraumgestaltungen bei Messen und Ausstellungen zunehmend Interesse. Dargestellt werden die Eigenschaften der Seilnetze, die Besonderheiten bei der Montage und ihre Lastabtragung. Die Kinematik der Vierecksmaschen ist die Ursache für die freie Formbarkeit der Netze. Für die ingenieurtechnische Erfassung der Netze ist es erforderlich, dass Methoden zur Verfügung gestellt werden, die eine Berechnung der Gleichgewichtsflächen ermöglichen, das Verhalten der Seilnetze unter äußeren Einwirkungen und unter Berücksichtigung der Vorspannung beschreiben und den Prozess des Montageprozesses erfassen.
Ein orthotropes Werkstoffgesetz für Folien
Authors: Karwath Michael , Wagner Rosemarie , Kröplin Bernd 
Published: April 2007

AbstractFolien besitzen, bedingt durch den Herstellungsprozess, ein orthotropes Tragverhalten, das im Allgemeinen bisher nicht berücksichtigt wurde. In diesem Beitrag wird eine Theorie vorgestellt, um die Werkstoffkenngrößen für einen beliebigen ebenen Spannungszustand zu ermitteln und ein experimenteller Weg angegeben, um diese zu verifizieren. Damit wird die Voraussetzung geschaffen, die Lastabtragung in Membranbauten wesentlich genauer vorherzusagen, als dies bisher möglich ist.
Zuschriften zu: Peil, U., Steiln, O.: Regen‐Wind‐induzierte Schwingungen – ein State‐of‐the‐Art‐Report
Authors: Peil Udo , Steiln Oliver 
Published: April 2007

Abstract[Stahlbau 76 (2007), H. 1, S. 34–46, 10.1002/stab.200710005]
The Location of Phenolic Antioxidants and Radicals at Interfaces Determines Their Activity
Authors: Heins Anja , McPhail Donald B. , Sokolowski Tobias , Stöckmann Heiko , Schwarz Karin 
Published: April 2007

AbstractTo characterize parameters influencing the antioxidant activity at interfaces a novel ESR approach was developed, which facilitates the investigation of the reaction stoichiometry of antioxidants towards stable radicals. To relate the activity of antioxidants towards the location of radicals at interfaces NMR experiments were conducted. Micellar solutions of SDS, Brij and CTAB were used to model interfaces of different chemical nature. The hydrophilic Fremy's radical was found to be solubilized exclusively in the aqueous phase of SDS micellar solution but partitioned partly into the hydrophilic headgroup area of Brij micelles. In contrast the hydrophobic galvinoxyl was exclusively located in the micellar phase with the increasing depth of intercalation in the order SDS < Brij < CTAB. Gallates revealed a higher stoichiometric factor towards galvinoxyl in CTAB systems, which is accounted to a concentration effect of antioxidant and radical being both solubilized in the palisade layer. In contrast, in SDS solutions hardly any reaction between galvinoxyl and gallates was found. SDS acted as a physical barrier between radical (palisade layer) and antioxidant (stern layer). The influence of the hydrophobic properties of the antioxidant was clearly seen in Brij micelles. Elongation of the alkyl chain in gallate molecule resulted in increasing stoichiometric factors in the presence of galvinoxyl being located in the deeper region of the bulky headgroup area. The reverse trend was found in the presence of Fremy's radical being located in the hydrated area of the micelles.
Impact of heart rate on mechanical dyssynchrony and left ventricular contractility in patients with heart failure and normal QRS duration
Authors: Kurita Tairo , Onishi Katsuya , Dohi Kaoru , Tanabe Masaki , Fujimoto Naoki , Tanigawa Takashi , Setsuda Morimichi , Isaka Naoki , Nobori Tsutomu , Ito Masaaki 
Published: April 2007

AbstractAims:The quantification of mechanical dyssynchrony has important diagnostic value and may help to determine optimal therapy in heart failure (HF). We hypothesized that mechanical dyssynchrony may be augmented at increased heart rates in patients with HF and normal QRS duration.Methods and results:From online segmental conductance catheter signals, we derived indices to quantify temporal and spatial aspects of mechanical dyssynchrony during systole in 20 control subjects, 20 HF patients with normal QRS duration, and 12 HF patients with complete left bundle branch block (CLBBB). Data were collected at baseline, and then following a 40 bpm increase in heart rate induced by right atrial pacing. Mechanical dyssynchrony in HF patients with normal QRS duration or CLBBB was higher than that found in control subjects. In HF patients with normal QRS duration, mechanical dyssynchrony increased from 37.4±4.8% at baseline to 43.2±4.4% with increased heart rate (p<0.01), the resultant degree of mechanical dyssynchrony was similar to that at baseline in the HF patients with CLBBB. Increased heart rate did not affect dyssynchrony in the control patients.Conclusion:Mechanical dyssynchrony was augmented as heart rate increased by right atrial pacing in patients with HF and normal QRS duration.
Internet-based cognitive behavioural therapy for subthreshold depression in people over 50 years old: a randomized controlled clinical trial
Authors: SPEK VIOLA , NYKLÍČEK IVAN , SMITS NIELS , CUIJPERS PIM , RIPER HELEEN , KEYZER JULES , POP VICTOR 
Published: April 2007

ABSTRACTBackgroundSubthreshold depression is a highly prevalent condition and a risk factor for developing a major depressive episode. Internet-based cognitive behaviour therapy may be a promising approach for the treatment of subthreshold depression. The current study had two aims: (1) to determine whether an internet-based cognitive behaviour therapy intervention and a group cognitive behaviour therapy intervention are more effective than a waiting-list control group; and (2) to determine whether the effect of the internet-based cognitive behaviour therapy differs from the group cognitive behaviour therapy intervention.MethodA total of 191 women and 110 men with subthreshold depression were randomized into internet-based treatment, group cognitive behaviour therapy (Lewinsohn's Coping With Depression course), or a waiting-list control condition. The main outcome measure was treatment response after 10 weeks, defined as the difference in pre- and post-treatment scores on the Beck Depression Inventory (BDI). Missing data, a major limitation of this study, were imputed using the Multiple Imputation (MI) procedure Data Augmentation.ResultsIn the waiting-list control group, we found a pre- to post-improvement effect size of 0·45, which was 0·65 in the group cognitive behaviour therapy condition and 1·00 within the internet-based treatment condition. Helmert contrasts showed a significant difference between the waiting-list condition and the two treatment conditions (p=0·04) and no significant difference between both treatment conditions (p=0·62).ConclusionsAn internet-based intervention may be at least as effective as a commonly used group cognitive behaviour therapy intervention for subthreshold depression in people over 50 years of age.
Exploring the inter-relationship of smoking age-at-onset, cigarette consumption and smoking persistence: genes or environment?
Authors: MORLEY KATHERINE I. , LYNSKEY MICHAEL T. , MADDEN PAMELA A. F. , TRELOAR SUSAN A. , HEATH ANDREW C. , MARTIN NICHOLAS G. 
Published: April 2007

ABSTRACTBackgroundWe investigated the genetic and environmental contributions to covariation between smoking age-at-onset, cigarette consumption and smoking persistence.MethodMultivariate biometrical modelling methods were applied to questionnaire data from Australian twins and their siblings (14 472 individuals from 6247 families). The contributions of genetic and environmental factors to covariation between the three traits were estimated, allowing for sex differences in both trait prevalence and the magnitude of genetic and environmental effects.ResultsAll traits were moderately heritable in males and females (estimates between 0·40 and 0·62), but there were sex differences in the extent to which additive genetic influences were shared across traits. Twin-specific environmental factors accounted for a substantial proportion of the variance in smoking age-at-onset in females (0·19) and males (0·12), but had little influence (<0·08) on other traits. Unique environmental factors were estimated to have a moderate influence on smoking age-at-onset (0·17 for females, 0·19 for males), but a stronger influence on other traits (between 0·39 and 0·49).ConclusionsThese results provide some insight into observed sex differences in smoking behaviour, and suggest that searching for pleiotropic genes may prove fruitful. However, further work on phenotypic definitions of smoking behaviour, particularly persistence, is warranted.
The rationale for and the current role of chemoradiotherapy
Authors: Prestwich R. J. , Shakespeare D. , Waters S. 
Published: April 2007

AbstractCombined-modality treatment using chemotherapy and radiotherapy, particularly concurrently, has now become the standard of care for many solid tumour sites on the basis of improvements in locoregional disease control and in some cases survival. The rationale for combined-modality treatment, potential mechanisms of interaction, the therapeutic ratio and the current place of sequential and concurrent chemoradiotherapy are discussed.
Research or reality: Within the context of UK radiotherapy and cancer services, where should research and investment be focused to best improve UK treatment outcomes?
Authors: O'Connell O.F.D. 
Published: April 2007

AbstractPurpose: It is now six years since the publication of the NHS Cancer Plan. During this time, there has been considerable investment and research within UK cancer services. Some progress has been made towards improving treatment outcomes, but obstacles persist. This article explores some recent advances in cancer treatment and considers whether UK cancer treatment outcomes will best improve through the clinical advances being made in cancer research or whether improvement now needs to be more explicitly driven via a strategic approach.Methodology: The article explores this question from two differing perspectives. First, from a research perspective, it reviews briefly the evidence for a selection of clinical advancements in cancer therapy that have all been cited as providing breakthroughs in treatment outcomes. Second, it considers the investment in cancer research within a more strategic context, focusing on the reality of managing an improvement programme in UK cancer services. Here, some of the practical obstacles to improving treatment outcomes are highlighted.Findings: Significant progress has been made over the past six years towards improving UK treatment outcomes. Much of this is a direct result of international advances in clinical research. Further progress, however, is required. This article argues that progress will best be achieved by focusing resources and research investment on tackling some of the endemic strategic obstacles, highlighted in this article, that are the present reality within UK cancer services.
Population pharmacokinetic modelling of non‐linear brain distribution of morphine: influence of active saturable influx and P‐glycoprotein mediated efflux
Authors: Groenendaal D , Freijer J , de Mik D , Bouw M R , Danhof M , de Lange E C M 
Published: April 2007

Background and purpose:Biophase equilibration must be considered to gain insight into the mechanisms underlying the pharmacokinetic‐pharmacodynamic (PK‐PD) correlations of opioids. The objective was to characterise in a quantitative manner the non‐linear distribution kinetics of morphine in brain.Experimental approach:Male rats received a 10‐min infusion of 4 mg kg−1of morphine, combined with a continuous infusion of the P‐glycoprotein (Pgp) inhibitor GF120918 or vehicle, or 40 mg kg−1morphine alone. Unbound extracellular fluid (ECF) concentrations obtained by intracerebral microdialysis and total blood concentrations were analysed using a population modelling approach.Key results:Blood pharmacokinetics of morphine was best described with a three‐compartment model and was not influenced by GF120918. Non‐linear distribution kinetics in brain ECF was observed with increasing dose. A one compartment distribution model was developed, with separate expressions for passive diffusion, active saturable influx and active efflux by Pgp. The passive diffusion rate constant was 0.0014 min−1. The active efflux rate constant decreased from 0.0195 min−1to 0.0113 min−1in the presence of GF120918. The active influx was insensitive to GF120918 and had a maximum transport (Nmax/Vecf) of 0.66 ng min−1ml−1and was saturated at low concentrations of morphine (C50=9.9 ng ml−1).Conclusions and implications:Brain distribution of morphine is determined by three factors: limited passive diffusion; active efflux, reduced by 42% by Pgp inhibition; low capacity active uptake. This implies blood concentration‐dependency and sensitivity to drug‐drug interactions. These factors should be taken into account in further investigations on PK‐PD correlations of morphine.British Journal of Pharmacology(2007)151, 701–712; doi:10.1038/sj.bjp.0707257
Influence of biophase distribution and P‐glycoprotein interaction on pharmacokinetic‐pharmacodynamic modelling of the effects of morphine on the EEG
Authors: Groenendaal D , Freijer J , de Mik D , Bouw M R , Danhof M , de Lange E C M 
Published: April 2007

Background and purpose:The aim was to investigate the influence of biophase distribution including P‐glycoprotein (Pgp) function on the pharmacokinetic‐pharmacodynamic correlations of morphine's actions in rat brain.Experimental approach:Male rats received a 10‐min infusion of morphine as 4 mg kg−1, combined with a continuous infusion of the Pgp inhibitor GF120918 or vehicle, 10 or 40 mg kg−1. EEG signals were recorded continuously and blood samples were collected.Key results:Profound hysteresis was observed between morphine blood concentrations and effects on the EEG. Only the termination of the EEG effect was influenced by GF120918. Biophase distribution was best described with an extended catenary biophase distribution model, with a sequential transfer and effect compartment. The rate constant for transport through the transfer compartment (k1e) was 0.038 min−1, being unaffected by GF120918. In contrast, the rate constant for the loss from the effect compartment (keo) decreased 60% after GF120918. The EEG effect was directly related to concentrations in the effect compartment using the sigmoidal Emaxmodel. The values of the pharmacodynamic parameters E0, Emax, EC50and Hill factor were 45.0 μV, 44.5 μV, 451 ng ml−1and 2.3, respectively.Conclusions and implications:The effects of GF120918 on the distribution kinetics of morphine in the effect compartment were consistent with the distribution in brain extracellular fluid (ECF) as estimated by intracerebral microdialysis. However, the time‐course of morphine concentrations at the site of action in the brain, as deduced from the biophase model, is distinctly different from the brain ECF concentrations.British Journal of Pharmacology(2007)151, 713–720; doi:10.1038/sj.bjp.0707258
The plasma membrane Na+/Ca2+exchange inhibitor KB‐R7943 is also a potent inhibitor of the mitochondrial Ca2+uniporter
Authors: Santo‐Domingo J , Vay L , Hernández‐SanMiguel E , Lobatón C D , Moreno A , Montero M , Alvarez J 
Published: April 2007

Background and purpose:The thiourea derivative KB‐R7943, originally developed as inhibitor of the plasma membrane Na+/Ca2+exchanger, has been shown to protect against myocardial ischemia‐reperfusion injury. We have studied here its effects on mitochondrial Ca2+fluxes.Experimental approach.[Ca2+] in cytosol, mitochondria and endoplasmic reticulum (ER), and mitochondrial membrane potential were monitored using both luminescent (targeted aequorins) and fluorescent (fura‐2, tetramethylrhodamine ethyl ester) probes in HeLa cells.Key results:KB‐R7943 was also a potent inhibitor of the mitochondrial Ca2+uniporter (MCU). In permeabilized HeLa cells, KB‐R7943 inhibited mitochondrial Ca2+uptake with a Ki of 5.5±1.3 μM (mean±S.D.). In intact cells, 10μM KB‐R7943 reduced by 80% the mitochondrial [Ca2+] peak induced by histamine. KB‐R7943 did not modify the mitochondrial membrane potential and had no effect on the mitochondrial Na+/Ca2+exchanger. KB‐R7943 inhibited histamine‐induced ER‐Ca2+release in intact cells, but not in cells loaded with a Ca2+‐chelator to damp cytosolic [Ca2+] changes. Therefore, inhibition of ER‐Ca2+‐release by KB‐R7943 was probably due to the increased feedback Ca2+‐inhibition of inositol 1,4,5‐trisphosphate receptors after MCU block. This mechanism also explains why KB‐R7943 reversibly blocked histamine‐induced cytosolic [Ca2+] oscillations in the same range of concentrations required to inhibit MCU.Conclusions and Implications:Inhibition of MCU by KB‐R7943 may contribute to its cardioprotective activity by preventing mitochondrial Ca2+‐overload during ischemia‐reperfusion. In addition, the effects of KB‐R7943 on Ca2+homeostasis provide new evidence for the role of mitochondria modulating Ca2+‐release and regenerative Ca2+‐oscillations. Search for permeable and selective MCU inhibitors may yield useful pharmacological tools in the future.British Journal of Pharmacology(2007)151, 647–654; doi:10.1038/sj.bjp.0707260
Endothelium‐independent constriction of isolated, pressurized arterioles by Nω‐nitro‐L‐arginine methyl ester (L‐NAME)
Authors: Murphy T V , Kotecha N , Hill M A 
Published: April 2007

Background and purpose:Nitric oxide synthase (NOS) inhibitors cause vasoconstriction in pressurized arterioles with myogenic tone. This suggests either tonic production of NO modulates myogenic tone or a direct, NOS‐independent effect of the NOS inhibitors. The nature of the contractile effect of the nitric oxide synthase inhibitor Nω‐nitro‐L‐arginine methyl ester (L‐NAME, 100 μM) on pressurised arterioles was investigated.Experimental approach:Segments of rat cremaster muscle first‐order arteriole were cannulated on glass micropipettes and maintained at an intraluminal pressure of 50, 70 or 120 mmHg.Key results:L‐NAME and the related compound L‐NA (100 μM) constricted pressurized vessels with myogenic tone. Removal of the endothelium did not cause constriction or alter myogenic tone, however the constrictor effect of L‐NAME persisted. The constrictor effect of L‐NAME was abolished by L‐arginine (1 mM). Other NO and cGMP pathway inhibitors, including the nNOS inhibitor 7‐nitroindazole (100 μM), the NO scavenger carboxy‐PTIO (100 μM), the guanylate cyclase inhibitor ODQ (10 μM) and the cGMP inhibitor Rp‐8CPT‐cGMPS (10 μM) did not cause constriction of the arterioles. L‐NAME caused a small (3‐4 mV) but not statistically significant depolarization of the arteriolar smooth muscle at both pressures. The constrictor effect was not prevented by the K+‐channel antagonist tetraethyl ammonium (TEA, 1 mM) or the KATP channel antagonist glibenclamide (1 μM).Conclusions and implications:These observations demonstrate that L‐NAME causes an endothelium‐ and NOS‐independent contraction of vascular smooth muscle in isolated skeletal muscle arterioles. It is suggested that the underlying mechanism relates to an arginine binding interaction.British Journal of Pharmacology (2007) 151, 602–609; doi:10.1038/sj.bjp.0707262
Cryptotanshinone inhibits chemotactic migration in macrophages through negative regulation of the PI3K signaling pathway
Authors: Don M‐J , Liao J‐F , Lin L‐Y , Chiou W‐F 
Published: April 2007

Background and purpose:Cryptotanshinone, the major tanshinone isolated fromSalvia miltiorrhizaBunge, exhibits anti‐inflammatory activity. However, there is no report on the effect of cryptotanshinone on recruitment of leukocytes to inflammatory sites. We therefore assessed the effects of cryptotanshinone on macrophage chemotaxis.Experimental approach:Macrophage migration induced by complement 5a (C5a) or macrophage inflammatory protein‐1α (MIP‐1α) was measuredin vitro. Intracellular kinase translocation and phosphorylation was assessed by Western blotting.Key results:RAW264.7 cell migration towards C5a (1μg ml−1) was significantly inhibited by cryptotanshinone (1, 3, 10 and 30 μM) in a concentration‐dependent manner. Primary human macrophages stimulated by C5a were similarly inhibited. C5a‐evoked migration in RAW264.7 cells was significantly suppressed by wortmannin (phosphatidylinositol 3‐kinase (PI3K) inhibitor), PD98059 (MEK1/2 inhibitor) and SB203580 (p38 mitogen‐activated protein kinase (MAPK) inhibitor), but not by SP600125 (c‐Jun N‐terminal kinase (JNK) inhibitor), suggesting that activation of PI3K, ERK1/2 and p38 MAPK signal pathways was involved in responses to C5a. Western blotting revealed that cryptotanshinone significantly inhibited PI3K‐p110γ membrane translocation and phosphorylation of Akt (PI3K downstream effector protein) and ERK1/2 induced by C5a. However, neither p38 MAPK nor JNK phosphorylation was affected by cryptotanshinone. Wortmannin significantly attenuated C5a‐induced PI3K‐p110γ translocation, Akt and ERK1/2 phosphorylation. PD98059 suppressed ERK1/2 phosphorylation but failed to modify PI3K‐p110γ translocation by C5a stimulation. Furthermore, MIP‐1α‐induced cell migration and PI3K‐p110γ translocation were also inhibited by cryptotanshinone in a concentration‐dependent manner.Conclusions and implications:Inhibition of macrophage migration by cryptotanshinone involved inhibition of PI3K activation with consequent reduction of phosphorylation of Akt and ERK1/2.British Journal of Pharmacology(2007)151, 638–646; doi:10.1038/sj.bjp.0707271
Grassland ecosystems in China: review of current knowledge and research advancement
Authors: Kang Le , Han Xingguo , Zhang Zhibin , Sun Osbert Jianxin 
Published: April 2007

Grasslands are the dominant landscape in China, accounting for 40% of the national land area. Research concerning China's grassland ecosystems can be chronologically summarized into four periods: (i) pre-1950s, preliminary research and survey of grassland vegetation and plant species by Russians, Japanese and Western Europeans, (ii) 1950–1975, exploration and survey of vegetation, soils and topography as part of natural resource inventory programmes by regional and national institutions mainly led by the Chinese Academy of Sciences, (iii) 1976–1995, establishment of field stations for long-term ecological monitoring and studies of ecosystem processes, (iv) 1996–present, comprehensive studies of community dynamics and ecosystem function integrating multi-scale and multidisciplinary approaches and experimental manipulations.
Major findings of scientific significance in China's grassland ecosystem research include: (i) improved knowledge on succession and biogeochemistry of the semi-arid and temperate grassland ecosystems, (ii) elucidation of life-history strategies and diapause characteristics of the native grasshopper species as one of the key grassland pests, and (iii) development of effective management strategies for controlling rodent pests in grassland ecosystems. Opportunities exist for using the natural grasslands in northern China as a model system to test ecosystem theories that so far have proven a challenge to ecologists worldwide.