bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limestones in Germany used as building stones: an overview
Authors: Siegesmund Siegfried , Grimm Wolf-Dieter , Dürrast Helmut , Ruedrich Joerg 
Published: March 2010

Abstract
Germany has an enormous number of different carbonate rock units, which vary widely in their geological age and sedimentary depositional environment. Limestones quarried from these exposures have a wide range of usages and applications, such as dimension and ornamental stones, floor tiles and panelling, and for use as paving stones and massive stones. Since antiquity, limestones were used as building materials in areas where they were naturally available and abundant. Limestones exhibit a relatively good weathering resistance, which is mainly controlled by the mineralogical composition and the rock structure. The susceptibility of limestones to weathering and alteration is only secondarily related to the stone's contact with rainwater and its exposure to frost. In this situation the pore space is the main controlling factor. Industrialization and the subsequent increase in air pollutants, which started at the end of the nineteenth century, led to the formation of dark and unsightly crust deposits on the limestones surfaces. These crusts, being the result of man-made activities, are the main weathering problem for carbonate dimension stones.
Mechanisms of damage by salt
Authors: Espinosa-Marzal R. M. , Scherer G. W. 
Published: March 2010

Abstract
Limestone is very susceptible to the aggressive action of salts. This paper describes the current understanding of the mechanisms by which salt crystallization causes damage to limestone. Crystallization pressure increases with the supersaturation of the solution, which may result from rapid drying and/or decrease in temperature. Salts with a tendency to achieve higher supersaturation owing to a high nucleation barrier are potentially able to induce more severe damage. In the presence of small pores (<100 nm), equilibrium thermodynamics indicates that crystallization pressure can result from the curvature dependence of the solubility of a salt crystal. Under non-equilibrium conditions, high transient stresses can occur even in larger pores. In the field, the complexity of salt weathering results from heat, moisture and ion transport coupled with in-pore crystallization during changing climatic conditions. This paper describes how progress in the modelling and numerical simulation of these coupled processes can contribute to a better understanding of the influencing factors and assessment of critical conditions.
Classically, tests such as the bursting test and the capillary rise experiment with simultaneous evaporation have been applied to evaluate qualitatively stone deterioration induced by salt crystallization. More recently our group has introduced other experimental methods to the field of salt weathering that provide quantitative information about nucleation and crystallization kinetics in porous materials (by differential scanning calorimetry), induced deformation and stress (by dynamic mechanical analysis and a novel warping test), and pore clogging caused by in-pore crystallization.
The final part of this paper is dedicated to a discussion of methods to prevent damage that may alter one of the crystallization steps, such as nucleation, crystal growth, disjoining pressure between mineral and crystal surfaces, or solution properties. Indeed, efficient treatments have been found for particular scenarios in the laboratory; however, the consequences of these treatments in the field, such as the behaviour at other temperatures and concentrations as well as the durability of the treatments, are not known yet.
Indeed, a lack of knowledge still exists in understanding the pore-level crystallization, such as the processes in the thin film between mineral surfaces and salt crystals that determine the disjoining pressure, or the dynamics of crystallization within the pore network that influence the salt distribution and stress in the stone. Atomic force microscopy, surface force measurements, nuclear magnetic resonance and simulations using molecular dynamics are promising methods to elucidate these points. By understanding these remaining questions a more reliable protection of stone against salt weathering will be achieved.
Acquired von Willebrand syndrome in patients with ventricular assist device or total artificial heart
Authors: Beyersdorf Friedhelm , Nakamura Lea , Benk Christoph , Berchtold-Herz Michael , Trummer Georg , Schlensak Christian , Heilmann Claudia , Geisen Ulrich , Zieger Barbara 
Published: March 2010

SummaryUnexplained bleeding episodes are associated with ventricular assist devices (VAD) and can occur in part due to acquired von Willebrand syndrome (AVWS). AVWS is characterised by loss of high molecular weight (HMW) multimers of von Willebrand factor (VWF) and decreased ratios of collagen binding capacity and ristocetin cofactor activity to VWF antigen. Loss of multimers can occur as VWF is subjected to increased shear stress, which occurs in presence of VADs. We studied 12 patients who required mechanical support of their native heart for terminal cardiac insufficiency. Nine patients underwent placement of a VAD, while three underwent placement of a total artificial heart (TAH), which is connected directly to heart and large cardiac vessels without cannulas. Within one day of VAD implantation, four of five patients evaluated demonstrated loss of HMW multimers and impaired VWF function. AVWS was present within two weeks of implantation in eight of nine patients, and in all seven tested patients after ≥3 months. Patients with different VAD types developed varying severities of AVWS. After VAD ex-plantation, HMW multimers were detectable and VWF function normalised in all patients. AVWS was not observed in the TAH patients studied. Our findings demonstrate that patients with an implanted VAD experience a rapid onset of AVWS that is quickly and completely reversed after device explantation. In addition, TAH patients do not develop AVWS. These results suggest that shear stress associated with exposure of blood to VAD cannulas and tubes may contribute to the development of AVWS.
The use of amlodipine, but not of P-glycoprotein inhibiting calcium channel blockers is associated with clopidogrel poor-response
Authors: Harmsze Ankie , Robijns Karen , van Werkum Jochem , Breet Nicoline , Hackeng Christian , ten Berg Jurrien , Ruven Hendrik , Klungel Olaf , Boer Anthonius de , Deneer Vera 
Published: March 2010

SummaryClopidogrel is a prodrug that has to be converted in vivo to its active metabolite by cytochrome (CYP)P450 iso-enzymes. As calcium channel blockers (CCBs) are inhibitors of CYP3A4, concomitant use of these drugs might play a role in the wide inter-individual variability in the response to clopidogrel. However, some CCBs also have strong inhibitory effects on the drug transporter P-glycoprotein (Pgp), which mediates clopidogrel‘s intestinal absorption. It was the aim of this study to evaluate the effect of co-administration of Pgp-inhibiting and non-Pgp-inhibiting CCBs on on-clopidogrel platelet reactivity in patients on dual antiplatelet therapy undergoing elective percutaneous coronary intervention (PCI). In a total of 623 consecutive patients undergoing elective PCI treated with clopidogrel and aspirin, platelet reactivity to 5 and 20 μM adenosine diphospate (ADP) and clopidogrel poor-response (defined as > 70% platelet aggregation to 20 μM ADP) were evaluated by light transmittance aggregometry. A total of 222 patients (35.6%) were on CCB treatment, of which 98 used Pgp-inhibiting CCBs (verapamil, nifedipine, diltiazem, barnidipine) and 124 patients used the non-Pgp-inhibiting CCB amlodipine. Adjusted mean ADP-induced on-clopidogrel platelet reactivity was significantly higher in both users of Pgp-inhibiting CCBs and amlodipine as compared to CCB non-users (all p<0.05). However, only the use of amlodipine was significantly associated with a 2.3-fold increased risk of clopidogrel poor-response. This study demonstrates that concomitant use of Pgp-inhibiting CCBs and amlodipine increases on-clopidogrel platelet reactivity. Only amlodi-pine was associated with clopidogrel poor-response. The drug-drug interaction between clopidogrel and amlodipine might be more clinically relevant as compared to P-glycoprotein-inhibiting CCBs.
A comparison of platelet function tests and thromboxane metabolites to evaluate aspirin response in healthy individuals and patients with coronary artery disease
Authors: Hvas Anne-Mette , Johnsen Helle Ladefoged , Hedegaard Sofie Sommer , Pedersen Susanne Bendesgaard , Mortensen Jette , Kristensen Steen Dalby , Grove Erik Lerkevang 
Published: March 2010

SummaryIndividualised antiplatelet therapy and platelet function testing have attracted considerable clinical interest, but several aspects of test performance have not been thoroughly evaluated. We investigated repeatability and concordance of light transmission aggregometry (LTA) induced with arachidonic acid (AA) 1.0 mM, PFA-100® induced with collagen/epinephrine, multiple electrode aggregometry (MEA) induced with AA 0.5 or 0.75 mM and VerifyNow® Aspirin. Patients with stable coronary artery disease (n=43) and healthy individuals (n=21) were included. All tests were performed in duplicate at baseline in healthy individuals and in duplicate for four days in all study participants during aspirin treatment. Serum and urinary thromboxane metabolites were measured several times to evaluate cyclooxygenase-1 inhibition by aspirin. MEA was most sensitive for aspirin as treatment induced a 12-fold difference in AA-induced platelet aggregation. Coefficients of variation for duplicate measurements at baseline (0.4–12%), during aspirin treatment (3–46%) and for day-to-day variability (3–37%) differed markedly between tests and were lowest for VerifyNow®. The prevalence of aspirin low-responsiveness also differed between tests (0–9%) and the agreement was low: kappa≤0.21 for all tests compared with AA-induced LTA (reference test), which correlated best with VerifyNow® (r=0.43, p<0.001). Urinary thromboxane metabolites did not correlate with any platelet function test, whereas serum thromboxane correlated with VerifyNow® Aspirin (r=0.41, p=0.001). Overall, repeatability was moderate and the correlation between tests was low. VerifyNow® Aspirin proved most reproducible, and this was the only assay showing a significant positive correlation with serum thromboxane. This study demonstrated that conclusions based on platelet function testing strongly depend on the assay used.
4G/5G polymorphism and haplotypes of SERPINE1 in atherosclerotic diseases of coronary arteries
Authors: Schrempf Matthias , Erl Anna , Mueller Jakob , Hoppmann Petra , Schömig Albert , Kastrati Adnan , Koch Werner 
Published: March 2010

SummaryWe assessed the association between common variation at the SERPINE1 (PAI1) locus and myocardial infarction (MI). Haplotype-tagging polymorphisms, including the 4G/5G deletion/insertion polymorphism and seven single nucleotide polymorphisms, were analysed in a German sample containing 3,657 cases with MI and 1,211 controls. The association between the 4G/5G polymorphism and MI was examined in a meta-analysis of data extracted from 32 studies (13,267 cases/14,716 controls). In addition, the relation between the 4G/5G polymorphism and coronary diseases, comprising MI, coronary artery disease, coronary heart disease, or the acute coronary syndrome, was assessed in a combined analysis enclosing 43 studies (17,278 cases/18,039 controls). None of the tagging polymorphisms was associated with MI in the present sample (p ≤ 0.34). The adjusted odds ratio (OR) for 4G allele carriers was 1.02 (95% confidence interval [CI] 0.87–1.19) compared to the 5G5G genotype. None of 13 common (frequency >1.0%) 8-marker haplotypes was related to the risk of MI. In a meta-analysis specifically addressing the association with MI, no elevated risk was found in the carriers of the 4G allele (OR 1.07, 95% CI 0.99–1.16; p = 0.11). A more general combined analysis of coronary diseases showed a marginally increased risk in 4G allele carriers (OR 1.08, 95% CI 1.00–1.16; p = 0.044). In essence, tagging polymorphisms, including the 4G/5G polymorphism, and common haplotypes of the SERPINE1 gene region were not associated with MI in a German sample, and no compelling evidence was obtained for a relationship of the 4G/5G polymorphism to MI and coronary atherosclerosis in a meta-analysis.
Effects of oversulfated and fucosylated chondroitin sulfates on coagulation
Authors: Fonseca Roberto , Oliveira Stephan-Nicollas , Pomin Vitor , Mecawi André , Araujo Iracema , Mourão Paulo 
Published: March 2010

SummaryWe report the effects of a chemically oversulfated chondroitin sulfate and a naturally fucosylated chondroitin sulfate on the coagulation system. The former has been recently identified as a contaminant of heparin preparations and the latter has been proposed as an alternative anticoagulant. The mechanism of action of these polymers on coagulation is complex and target different components of the coagulation system. They have serpin-independent anticoagulant activity, which preponderates in plasma. They also have serpin-dependent anticoagulant activity but differ significantly in the target coagulation protease and preferential serpin. Their anticoagulant effects differ even more markedly when tested as inhibitors of coagulation proteases using plasma as a source of serpins. It is possible that the difference is due to the high availability of fucosylated chondroitin sulfate whereas over-sulfated chondroitin sulfate has strong unspecific binding to plasma protein and low availability for the binding to serpins. When tested using a venous thrombosis experimental model, oversulfated chondroitin sulfate is less potent as an antithrombotic agent than fucosylated chondroitin sulfate. These highly sulfated chondroitin sulfates activate factor XII in in vitro assays, based on kallikrein release. However, only fucosylated chondroitin sulfate induces hypotension when intravenously injected into rats. In conclusion, the complexity of the regulatory mechanisms involved in the action of highly sulfated polysaccharides in coagulation requires their analysis by a combination of in vitro and in vivo assays. Our results are relevant due to the urgent need for new anticoagulant drugs or alternative sources of heparin.
Blocking endothelial protein C receptor (EPCR) accelerates thrombus development in vivo
Authors: Centelles Miguel , Puy Cristina , Lopez-Sagaseta Jacinto , Fukudome Kenji , Montes Ramón , Hermida José 
Published: March 2010

SummaryThe endothelial protein C receptor (EPCR) plays an anticoagulant role by improving protein C activation. Although low levels of activated protein C (APC) constitute a thrombosis risk factor, the relationship between modulating EPCR function and thrombosis has not been addressed so far. Monoclonal antibodies (mAb) against murine EPCR were raised, and their ability to block protein C/APC binding was tested. The ferric chloride carotid artery injury model in mice was chosen to test the effect of anti-EPCR mAb on thrombus formation. The time to total occlusion of the vessel was analysed in three groups, given an isotype control mAb (IC), a blocking (RCR-16) or a non-blocking (RCR-20) anti-EPCR mAb. RCR-16 prevented the interaction between protein C/APC and EPCR as demonstrated by surface plasmon resonance and flow cytometry, and inhibited the activation of protein C on the endothelium. IC and RCR-20 were unable to induce such effects. In vivo, RCR-16 shortened the time to total vessel occlusion with respect to IC [13.4 ± 1.0 (mean ± SD) and 17.8 ± 3.2 minutes, respectively, p<0.001]. Occlusive thrombi lasting for more than one hour were observed in all RCR-16-treated animals, but only in 43% of IC-treated ones. Results with RCR-20 were indistinguishable from those observed with IC. For the first time, a direct relationship between blocking EPCR and thrombosis is demonstrated. Blocking anti-EPCR autoantibodies can predispose to thrombosis episodes and may constitute a new therapeutic target.
Rare thromboses of cerebral, splanchnic and upper-extremity veins
Authors: Stefano Valerio De , Martinelli Ida 
Published: March 2010

SummaryVenous thrombosis typically involves the lower extremity circulation. Rarely, it can occur in the cerebral or splanchnic veins and these are the most frightening manifestations because of their high mortality rate. A third site of rare venous thrombosis is the deep system of the upper extremities that, as for the lower extremity, can be complicated by pulmonary embolism and post-thrombotic syndrome. The authors conducted a narrative review focused on clinical manifestations, risk factors, and treatment of rare venous thromboses. Local risk factors such as infections or cancer are frequent in thrombosis of cerebral or portal veins. Upper extremity deep-vein thrombosis is mostly due to local risk factors (catheter- or effort-related). Common systemic risk factors for rare venous thromboses are inherited thrombophilia and oral contraceptive use; chronic myeloproliferative neoplasms are closely associated with splanchnic vein thrombosis. In the acute phase rare venous thromboses should be treated conventionally with low-molecular-weight heparin. Use of local or systemic fibrinolysis should be considered in the case of clinical deterioration in spite of adequate anticoagulation. Anticoagulation with vitamin K-antagonists is recommended for 3–6 months after a first episode of rare venous thrombosis. Indefinite anticoagulation is recommended for Budd-Chiari syndrome, recurrent thrombosis or unprovoked thrombosis and permanent risk factors. In conclusion, the progresses made in the last couple of decades in diagnostic imaging and the broadened knowledge of thrombophilic abnormalities improved the recognition of rare venous thromboses and the understanding of pathogenic mechanisms. However, the recommendations for treatment mainly derive from observational studies.
Modality-dependent “What” and “Where” Preparatory Processes in Auditory and Visual Systems
Authors: Diaconescu Andreea Oliviana , Alain Claude , McIntosh Anthony Randal 
Published: March 2010

Abstract
The present study examined the modality specificity and spatio-temporal dynamics of “what” and “where” preparatory processes in anticipation of auditory and visual targets using ERPs and a cue–target paradigm. Participants were presented with an auditory (Experiment 1) or a visual (Experiment 2) cue that signaled them to attend to the identity or location of an upcoming auditory or visual target. In both experiments, participants responded faster to the location compared to the identity conditions. Multivariate spatio-temporal partial least square (ST-PLS) analysis of the scalp-recorded data revealed supramodal “where” preparatory processes between 300–600 msec and 600–1200 msec at central and posterior parietal electrode sites in anticipation of both auditory and visual targets. Furthermore, preparation for pitch processing was captured at modality-specific temporal regions between 300 and 700 msec, and preparation for shape processing was detected at occipital electrode sites between 700 and 1150 msec. The spatio-temporal patterns noted above were replicated when a visual cue signaled the upcoming response (Experiment 2). Pitch or shape preparation exhibited modality-dependent spatio-temporal patterns, whereas preparation for target localization was associated with larger amplitude deflections at multimodal, centro-parietal sites preceding both auditory and visual targets. Using a novel paradigm, the study supports the notion of a division of labor in the auditory and visual pathways following both auditory and visual cues that signal identity or location response preparation to upcoming auditory or visual targets.
Beyond the Memory Mechanism: Person-selective and Nonselective Processes in Recognition of Personally Familiar Faces
Authors: Sugiura Motoaki , Mano Yoko , Sasaki Akihiro , Sadato Norihiro 
Published: March 2010

Abstract
Special processes recruited during the recognition of personally familiar people have been assumed to reflect the rich episodic and semantic information that selectively represents each person. However, the processes may also include person nonselective ones, which may require interpretation in terms beyond the memory mechanism. To examine this possibility, we assessed decrease in differential activation during the second presentation of an identical face (repetition suppression) as an index of person selectivity. During fMRI, pictures of personally familiar, famous, and unfamiliar faces were presented to healthy subjects who performed a familiarity judgment. Each face was presented once in the first half of the experiment and again in the second half. The right inferior temporal and left inferior frontal gyri were activated during the recognition of both types of familiar faces initially, and this activation was suppressed with repetition. Among preferentially activated regions for personally familiar over famous faces, robust suppression in differential activation was exhibited in the bilateral medial and anterior temporal structures, left amygdala, and right posterior STS, all of which are known to process episodic and semantic information. On the other hand, suppression was minimal in the posterior cingulate, medial prefrontal, right inferior frontal, and intraparietal regions, some of which were implicated in social cognition and cognitive control. Thus, the recognition of personally familiar people is characterized not only by person-selective representation but also by nonselective processes requiring a research framework beyond the memory mechanism, such as a social adaptive response.
Perceptual Fusion Tendency of Speech Sounds
Authors: Huang Ying , Li Jingyu , Zou Xuefei , Qu Tianshu , Wu Xihong , Mao Lihua , Wu Yanhong , Li Liang 
Published: March 2010

Abstract
To discriminate and to recognize sound sources in a noisy, reverberant environment, listeners need to perceptually integrate the direct wave with the reflections of each sound source. It has been confirmed that perceptual fusion between direct and reflected waves of a speech sound helps listeners recognize this speech sound in a simulated reverberant environment with disrupting sound sources. When the delay between a direct sound wave and its reflected wave is sufficiently short, the two waves are perceptually fused into a single sound image as coming from the source location. Interestingly, compared with nonspeech sounds such as clicks and noise bursts, speech sounds have a much larger perceptual fusion tendency. This study investigated why the fusion tendency for speech sounds is so large. Here we show that when the temporal amplitude fluctuation of speech was artificially time reversed, a large perceptual fusion tendency of speech sounds disappeared, regardless of whether the speech acoustic carrier was in normal or reversed temporal order. Moreover, perceptual fusion of normal-order speech, but not that of time-reversed speech, was accompanied by increased coactivation of the attention-control-related, spatial-processing-related, and speech-processing-related cortical areas. Thus, speech-like acoustic carriers modulated by speech amplitude fluctuation selectively activate a cortical network for top–down modulations of speech processing, leading to an enhancement of perceptual fusion of speech sounds. This mechanism represents a perceptual-grouping strategy for unmasking speech under adverse conditions.