bluuebunny/crossref_metadata_2025_split huggingface dataset:
Left Atrial Diameter, Aortic Mean Gradient, and Hemoglobin for Risk Stratification in Patients Undergoing Transcatheter Aortic Valve Implantation
Authors: Gotzmann Michael , Thiessen Anja , Lindstaedt Michael , Mügge Andreas , Ewers Aydan 
Published: March 2013

AbstractBackgroundTranscatheter aortic valve implantation (TAVI) is an alternative treatment of severe symptomatic aortic stenosis (AS) in patients with high operative risk. In spite of favorable entire results, long‐term mortality of patients is high.HypothesisThe present study aims to identify independent preprocedural risk factors to improve risk stratification in these highly selected patients.MethodsThis prospective study included 202 consecutive patients with severe symptomatic AS and high operative risk (mean logistic European System for Cardiac Operative Risk Evaluation, 22 ± 17%; mean age, 79 ± 6 years; 107 female). Preprocedural comprehensive examinations were performed (laboratory, electrocardiography, echocardiography, cardiac catheterization). All patients received transfemoral or transaxillary TAVI with a CoreValve prosthesis (Medtronic, Minneapolis, MN).ResultsDuring a follow‐up of 535 ± 333 days, 56 patients (28%) reached the primary study end point (all‐cause mortality). Independent predictors of long‐term mortality were as follows: hemoglobin <12.5 g/dL (hazard risk [HR], 3.62; 95% confidence interval [CI], 2.025–6.468; P < 0.001), aortic mean gradient ≤41 mm Hg (HR, 2.16; 95% CI, 1.272–3.655; P = 0.004), and left atrial diameter > 42 mm (HR, 3.09; 95% CI, 1.588–6.019; P = 0.001). Our risk‐stratification model based on these independent predictors separated patients into 4 groups with high (74%), intermediate (37%), low (18%), and very low (3%) all‐cause mortality.ConclusionsIn patients undergoing TAVI, preprocedural assessment of hemoglobin, aortic mean gradient, and left atrial diameter provides independent prognostic information and therefore contributes to improved risk stratification in TAVI.
Automatic cell cloning assay for determining the clonogenic capacity of cancer and cancer stem‐like cells
Authors: Fedr Radek , Pernicová Zuzana , Slabáková Eva , Straková Nicol , Bouchal Jan , Grepl Michal , Kozubík Alois , Souček Karel 
Published: March 2013

AbstractThe clonogenic assay is a well‐established in vitro method for testing the survival and proliferative capability of cells. It can be used to determine the cytotoxic effects of various treatments including chemotherapeutics and ionizing radiation. However, this approach can also characterize cells with different phenotypes and biological properties, such as stem cells or cancer stem cells. In this study, we implemented a faster and more precise method for assessing the cloning efficiency of cancer stem‐like cells that were characterized and separated using a high‐speed cell sorter. Cell plating onto a microplate using an automatic cell deposition unit was performed in a single‐cell or dilution rank mode by the fluorescence‐activated cell sorting method. We tested the new automatic cell‐cloning assay (ACCA) on selected cancer cell lines and compared it with the manual approach. The obtained results were also compared with the results of the limiting dilution assay for different cell lines. We applied the ACCA to analyze the cloning capacity of different subpopulations of prostate and colon cancer cells based on the expression of the characteristic markers of stem (CD44 and CD133) and cancer stem cells (TROP‐2, CD49f, and CD44). Our results revealed that the novel ACCA is a straightforward approach for determining the clonogenic capacity of cancer stem‐like cells identified in both cell lines and patient samples. © 2013 International Society for Advancement of Cytometry
Blast cell deficiency of CD11a as a marker of acute megakaryoblastic leukemia and transient myeloproliferative disease in children with and without Down syndrome
Authors: Boztug Heidrun , Schumich Angela , Pötschger Ulrike , Mühlegger Nora , Kolenova Alexandra , Reinhardt Katarina , Dworzak Michael 
Published: March 2013

BackgroundThe classification of acute myeloid leukemia (AML) FAB subtype M7 relies on immunophenotypic assessment. CD41 is expressed throughout all stages of maturation of megakaryocytes and has therefore been described as a specific blast cell marker in AML M7 as well as in transient myeloproliferative disease (TMD) of patients with Down syndrome (DS). However, technical difficulties underlie the need for new markers for these entities.MethodsWe evaluated the expression of human lymphocyte function‐associated antigen 1 (CD11a) in a large cohort of pediatric AML and TMD patients (n = 91) of the Austrian AML‐BFM 98 and 2004 studies.ResultsWe found a consistent deficiency of CD11a as assessed by mean fluorescence intensity in all patients with non‐DS AML M7 (n = 8) and M6 (n = 1), all cases of classical DS‐AML (n = 12) as well as TMD (n = 15) that was statistically significant in comparison to non‐DS AML M0‐M5 patients (n = 55; P < 0.001, sensitivity 100%). Only three of 55 Non‐DS M0‐5 patients were CD11a deficient (specificity 95%). Monocytic leukemias (M4/5) and normal monocytes typically showed a high CD11a expression, FAB types M1/2 and normal neutrophils an intermediate expression level, while all M3 leukemias were rather low in CD11a expression.ConclusionsWe conclude, that deficiency of CD11a expression should be added to the diagnostic criteria of AML‐M7, classical DS‐AML and TMD. © 2013 International Clinical Cytometry Society
Effects of pulse period of near‐field ground motions on the seismic demands of soil–MDOF structure systems using mathematical pulse models
Authors: Khoshnoudian Faramarz , Ahmadi Ehsan 
Published: March 2013

SUMMARYIn this paper, the effects of pulse period associated with near‐field ground motions on the seismic demands of soil–MDOF structure systems are investigated by using mathematical pulse models. Three non‐dimensional parameters are employed as the crucial parameters, which govern the responses of soil–structure systems: (1) non‐dimensional frequency as the structure‐to‐soil stiffness ratio; (2) aspect ratio of the superstructure; and (3) structural target ductility ratio. The soil beneath the superstructure is simulated on the basis of the Cone model concept. The superstructure is modeled as a nonlinear shear building. Interstory drift ratio is selected as the main engineering demand parameter for soil–structure systems. It is demonstrated that the contribution of higher modes to the response of soil–structure system depends on the pulse‐to‐interacting system period ratio instead of pulse‐to‐fixed‐base structure period ratio. Furthermore, results of the MDOF superstructures demonstrate that increasing structural target ductility ratio results in the first‐mode domination for both fixed‐base structure and soil–structure system. Additionally, increasing non‐dimensional frequency and aspect ratio of the superstructure respectively decrease and increase the structural responses. Moreover, comparison of the equivalent soil–SDOF structure system and the soil–MDOF structure system elucidates that higher‐mode effects are more significant, when soil–structure interaction is taken into account. In general, the effects of fling step and forward directivity pulses on activating higher modes of the superstructure are more sever in soil–structure systems, and in addition, the influences of forward directivity pulses are more considerable than fling step ones. Copyright © 2013 John Wiley & Sons, Ltd.
Probing deep weathering in the Shale Hills Critical Zone Observatory, Pennsylvania (USA): the hypothesis of nested chemical reaction fronts in the subsurface
Authors: Brantley Susan L. , Holleran Molly E. , Jin Lixin , Bazilevskaya Ekaterina 
Published: March 2013

ABSTRACTWeathering is both an acid‐base and a redox reaction in which rocks are titrated by meteoric carbon dioxide (CO2) and oxygen (O2). In general, the depths of these weathering reactions are unknown. To determine such depths, cuttings of Rose Hill shale were investigated from one borehole from the ridge and four boreholes from the valley at the Susquehanna Shale Hills Observatory (SSHO). Pyrite concentrations are insignificant to depths of 23 m under the ridge and 8–9 m under the valley. Likewise, carbonate concentrations are insignificant to 22 and 2 m, respectively. In addition, a 5–6 m‐thick fractured layer directly beneath the land surface shows evidence for loss of illite, chlorite, and feldspar. Under the valley, secondary carbonates may have precipited.The limited number of boreholes and the tight folding make it impossible to prove that depth variations result from weathering instead of chemical heterogeneity within the parent shale. However, carbonate depletion coincides with the winter water table observed at ~20 m (ridge) and ~2 m depth (valley). It would be fortuitous if carbonate‐containing strata are found under ridge and valley only beneath the water table. Furthermore, pyrite and carbonate react quickly and many deep reaction fronts for these minerals are described in the literature. We propose that deep transport of O2 initiates weathering at SSHO and many other localities because pyrite commonly oxidizes autocatalytically to acidify porewaters and open porosity. According to this hypothesis, the mineral distributions at SSHO are nested reaction fronts that overprint protolith stratigraphy. The fronts are hypothesized to lie subparallel to the land surface because O2 diffuses to the water table and causes oxidative dissolution of pyrite. Pyrite‐derived sulfuric acid (H2SO4) plus CO2 also dissolve carbonates above the water table. To understand how reaction fronts record long‐term coupling between erosion and weathering will require intensive mapping of the subsurface. Copyright © 2013 John Wiley & Sons, Ltd.
Reproductive impacts of tributyltin (TBT) and triphenyltin (TPT) in the hermaphroditic freshwater gastropod Lymnaea stagnalis
Authors: Giusti Arnaud , Barsi Alpar , Dugué Maël , Collinet Marc , Thomé Jean-Pierre , Joaquim-Justo Célia , Roig Benoit , Lagadic Laurent , Ducrot Virginie 
Published: March 2013

Abstract

Tributyltin (TBT) and triphenyltin (TPT) are emblematic endocrine disruptors, which have been mostly studied in gonochoric prosobranchs. Although both compounds can simultaneously occur in the environment, they have mainly been tested separately for their effects on snail reproduction. Because large discrepancies in experimental conditions occurred in these tests, the present study aimed to compare the relative toxicity of TBT and TPT under similar laboratory conditions in the range of 0 ng Sn/L to 600 ng Sn/L. Tests were performed on the simultaneous hermaphrodite Lymnaea stagnalis, a freshwater snail in which effects of TPT were unknown. Survival, shell length, and reproduction were monitored in a 21-d semistatic test. Frequency of abnormal eggs was assessed as an additional endpoint. Triphenyltin hampered survival while TBT did not. Major effects on shell solidity and reproduction were observed for both compounds, reproductive outputs being more severely hampered by TBT than by TPT. Considering the frequency of abnormal eggs allowed increasing test sensitivity, because snail responses to TBT could be detected at concentrations as low as 19 ng Sn/L. However, the putative mode of action of the 2 compounds could not be deduced from the structure of the molecules or from the response of apical endpoints. Sensitivity of L. stagnalis to TBT and TPT was compared with the sensitivity of prosobranch mollusks with different habitats and different reproductive strategies. Environ Toxicol Chem 2013;32:1552–1560. © 2013 SETAC
Evaluation of PCB bioaccumulation by Lumbriculus variegatus in field-collected sediments
Authors: Burkhard Lawrence P. , Mount David R. , Highland Terry L. , Hockett J. Russell , Norberg-King Teresa , Billa Nanditha , Hawthorne Steven B. , Miller David J. , Grabanski Carol B. 
Published: March 2013

Abstract

Review of data from several contaminated sediment sites suggested that biota-sediment accumulation factors (BSAFs) declined with increasing contaminant concentrations in the sediment. To evaluate the consistency and possible causes of this behavior, polychlorinated biphenyl (PCB)–contaminated sediment samples from the Hudson, Grasse, and Fox River Superfund sites were used in sediment bioaccumulation tests with the freshwater oligochaete, Lumbriculus variegatus, with PCB concentrations in interstitial water (IW) quantified using polyoxymethylene passive samplers. Measured BSAFs tended to decrease with increasing PCB concentration in sediment, especially for the more highly chlorinated congeners. Measures of partitioning between sediment, IW, and oligochaetes showed that measured sediment–IW partition coefficients (KTOC) tended to increase slightly with increasing sediment contamination, whereas the ratio of tissue PCB to IW PCB tended to decrease with increasing concentration in IW. Variation in accumulation among sediments was clearly influenced by bioavailability, as reflected by IW measurements, although the specific cause of varying KTOC was not clear. Calculated partitioning between IW and organism lipid (Klipid) indicated that accumulation was generally 5 to 10-fold higher than would be predicted if Klipid was approximately equal to the n-octanol–water partition coefficient (KOW). While affirming previous observations of decreasing BSAFs with increasing PCB contamination, the relatively shallow slope of the observed relationship in the current data may suggest that this concentration dependence is not a major uncertainty in sediment risk assessment, particularly if measurements of PCBs in IW are incorporated. Environ Toxicol Chem 2013;32:1495–1503. © 2013 SETAC
Complexes of the antimicrobial ciprofloxacin with soil, peat, and aquatic humic substances
Authors: Aristilde Ludmilla , Sposito Garrison 
Published: March 2013

Abstract

Natural organic matter (NOM) is implicated in the binding of antibiotics by particles in soils and waters. The authors' previous computational study revealed structural rearrangement of both hydrophilic and hydrophobic moieties of NOM to favor H-bonding and other intermolecular interactions, as well as both competition with ion-exchange reactions and bridging interactions by NOM-bound divalent cations. The importance of these interactions was investigated using fluorescence-quenching spectroscopy to study the adsorption of ciprofloxacin (Cipro), a fluoroquinolone antibiotic, on 4 reference humic substances (HSs): Elliott soil humic acid (HA), Pahokee peat HA, and Suwannee river HA and fulvic acid. A simple affinity spectrum HS model was developed to characterize the cation-exchange capacity and the amount of H-bond donor moieties as a function of pH. The adsorption results stress the influence of both pH conditions and the type of HS: both soil HA and peat HA exhibited up to 3 times higher sorption capacity than the aquatic HS at pH ≥ 6, normalizing to the aromatic C content accounted for the differences among the terrestrial HS, and increasing the concentration of divalent cations led to a decrease in adsorption on aquatic HA but not on soil HA. In addition, the pH-dependent speciation models of the Cipro–HS complexes illustrate an increase in complexation due to an increase in deprotonation of HS ligands with increasing pH and, at circumneutral and alkaline pH, enhanced complexation of zwitterionic Cipro only in the presence of soil HA and peat HA. The findings of the present study imply that, in addition to electrostatic interactions, van der Waals interactions as facilitated by aromatic structures and H-bond donating moieties in terrestrial HS may facilitate a favorable binding environment. Environ Toxicol Chem 2013;32:1467–1478. © 2013 SETAC
European studies on the prevalence of dementia in the elderly: time for a step towards a methodological consensus
Authors: Misiak Blazej , Cialkowska‐Kuzminska Magdalena , Frydecka Dorota , Chladzinska‐Kiejna Sylwia , Kiejna Andrzej 
Published: March 2013

ObjectiveThe aim of this study was to discuss methodological limitations in studies on the prevalence of dementia across European countries with particular attention to post‐EURODEM studies.MethodsTwo people independently focused on an iterative literature search for studies published in the years 2000–2012 using the following keywords: ‘dementia’, ‘Alzheimer’, ‘incidence’, ‘prevalence’ that were cross‐linked with names of European countries. After that, the results obtained were compared and publications in English were included in a subsequent analysis.ResultsWe included 26 studies published in the years 2000–2012. The majority of epidemiological studies come from Spain and Italy. The past decade has not provided prevalence rates from a considerable number of countries. There is also a lack of nationwide surveys on the prevalence of dementia. Predominantly, epidemiological studies on the prevalence of dementia follow a two‐stage approach that consists of a screening phase and a subsequent confirmation of dementia. However, several differences, particularly with regard to the neuropsychological instruments used, still exist and contribute to inconsistent prevalence rates.ConclusionsAlthough the EURODEM study was a milestone in the epidemiology of dementia in Europe and provided several future directions for research, methodological limitations are apparent in a number of European studies on the prevalence of dementia and require particular attention. In particular, a variety of diagnostic instruments requires unification for future studies. On the other hand, given the lack of epidemiological studies from a number of countries and the increasing prevalence of dementia, the need for population‐based surveys should be emphasized. Copyright © 2013 John Wiley & Sons, Ltd.
Assessing crop yield and crop water productivity and optimizing irrigation scheduling of winter wheat and summer maize in the Haihe plain using SWAT model
Authors: Sun Chen , Ren Li 
Published: March 2013

AbstractHaihe plain is an important food production area in China, facing an increasing water shortage. The water used for agriculture accounts for about 70% of total water resources. Thus, it is critical to optimize the irrigation scheduling for saving water and increasing crop water productivity (CWP). This study first simulated crop yield and CWP for winter wheat and summer maize in historical scenario during 1961–2005 for Haihe plain using previously well‐established Soil and Water Assessment Tool model. Then, scenarios under historical irrigation (scenario 1) and sufficient irrigation (scenario 2) were, respectively, simulated both with sufficient fertilizer. The crop yield in scenario 2 was considered as the potential crop yield. The optimal irrigation scheduling with sufficient fertilizer (scenario 3) was explored by iteratively adjusting irrigation scheduling based on the scenario 1 and previous studies related to water stress on crop growth. Results showed that net irrigation amount was, respectively, reduced 23.1% and 18.8% in scenario 3 for winter wheat and summer maize when compared with scenario 1. The CWP was 12.1% and 8.2% higher with very slight change of crop yield. Using optimal irrigation scheduling could save 8.8 × 108 m3 irrigation water and reduce about 16.3% groundwater over‐exploitation in winter wheat growth period. The corresponding yield was 18.5% and 12.9% less than potential yield for winter wheat and summer maize but using less irrigation water. Therefore, it could be considered that the optimal irrigation was reasonable, which provided beneficial suggestions for increasing efficiency of agricultural water use with sustainable crop yield in Haihe plain. Copyright © 2013 John Wiley & Sons, Ltd.
Assessment of a seasonal calibration technique using multiple objectives in rainfall–runoff analysis
Authors: Kim H.S. , Lee S. 
Published: March 2013

AbstractThe hydrological response characteristics for the catchments in the Republic of Korea are related to a strong seasonality in the rainfall and streamflow distributions with distinct wet and dry seasons. This study aims to improve a model's ability to predict streamflows by minimizing information loss from the available data during the calibration processes. This study assesses calibration techniques incorporating a multi‐objective approach and seasonal calibration. The lumped conceptual rainfall–runoff model IHACRES was applied to selected catchments in Korea. The model was calibrated based on three different methods: the classical approach using a single performance statistic (the single‐objective method), the multi‐objective approach (the multi‐objective method (I)) and the combined approach incorporating multi‐objective and seasonal calibrations (the multi‐objective method (II)). In the multi‐objective approach, the ‘best fit’ models in the calibration period were selected by considering the trade‐offs among multiple statistics. During seasonal calibration, the calibration period was divided into four seasons to investigate whether these calibrated models can improve the model performance with regards to seasonal climate, rainfall and streamflow distributions. The adequacy of the three different calibration methods was assessed through comparison of the variability of model performance in high and low flows and water balance for the entire period and for each seasonal period. The multi‐objective methods yielded more accurate and consistent predictions for high and low flows and water balance simultaneously, compared to the single‐objective method. In particular, the multi‐objective method (II) produces the best modelling capacity to capture the non‐stationary nature of the hydrological response under different climate conditions. The pattern of improvement with the multi‐objective method (II) was generally consistent through the seasons, with the exception of the winter period in the regions partially affected by snow. This exception is due to a potential limitation of the IHACRES model in reflecting the impact of snow on the catchment hydrology. Copyright © 2013 John Wiley & Sons, Ltd.
Modelling incoming radiation on a linear disturbance and its impact on the ground thermal regime in discontinuous permafrost
Authors: Williams T. J. , Quinton W. L. 
Published: March 2013

AbstractHuman‐induced disturbances and climate‐driven warming have resulted in unprecedented permafrost thaw in the zone of discontinuous permafrost. In a peatland environment south of Fort Simpson, NWT, we study the contribution of increases in incoming radiation to the ground surface, caused by removal of the tree canopy along linear disturbances, to changes in the ground thermal regime. A physically based understanding of thaw processes along linear disturbances is required in order to better understand the slow recovery of lines in this environment and to be able to efficiently reduce this impact during future resource exploration. The impact of increases in incoming radiation are examined through the development of a model (seismic incoming radiation model) to quantify these inputs, which are then used to drive the one‐dimensional coupled atmospheric‐surface‐subsurface model COUP. Results of this study show that incoming radiation (shortwave + longwave) is increased by up to 11% in a typical cutline compared to an undisturbed canopy. Relative to potential changes in near‐surface soil moisture, these increases in radiation do not appear to be an important control of permafrost thaw along linear disturbances. Field observations confirm that increased permafrost thaw on disturbances often occur irrespective of variations in incoming radiation. Copyright © 2013 John Wiley & Sons, Ltd.