bluuebunny/crossref_metadata_2025_split huggingface dataset:
Invasiveness risk of biofuel crops using Jatropha curcas L. as a model species
Authors: Negussie Aklilu , Achten Wouter M. J. , Norgrove Lindsey , Hermy Martin , Muys Bart 
Published: May 2013

AbstractBiofuel crops are promoted as a climate friendly alternative to fossil energy. Yet environmental risks such as potential biodiversity loss are not always adequately considered. This might occur directly as a consequence of land‐use change from natural systems to biofuel plantations, but also through invasive behavior of the biofuel species, as it might disperse and establish into adjacent natural systems. Therefore, there is a need to perform ex‐ante invasiveness risk assessments including field trials on new biofuel species before they get promoted and expanded on a large scale. This perspective uses Jatropha curcas L. as a model biofuel crop and reviews the biological traits and the circumstantial factors which may contribute to its invasive behavior. J. curcas has recently received much attention as a biodiesel ‘wonder crop’ and is being planted at large scale without scientific study on its invasiveness risk. We applied two risk assessment frameworks to provide an ex‐ante invasiveness risk assessment and obtained that J. curcas is a species with a high invasiveness risk, which is in contradiction with recent experimental evidence. We discuss the limitations of the available risk assessment frameworks, which may have led to unreliable prediction. We interpret the outcome of this theoretical exercise with some recommendations for the selection, introduction, cultivation, and processing stages of J. curcas and other biofuel crops to minimize invasiveness risk. Finally we point to the responsibilities of investors and governments and the need for integrated research of the whole biofuel production supply chain to avoid bio‐invasions. © 2013 Society of Chemical Industry and John Wiley & Sons, Ltd
Theoretical Spectroscopy of the NiII Intermediate States in the Catalytic Cycle and the Activation of [NiFe] Hydrogenases
Authors: Krämer Tobias , Kampa Mario , Lubitz Wolfgang , van Gastel Maurice , Neese Frank 
Published: May 2013

Abstract[NiFe] hydrogenases catalyze the reversible oxidation of dihydrogen. The corresponding catalytic cycle involves a formidable number of redox states of the Ni‐Fe active site; these can be distinguished experimentally by the IR stretching frequencies of their CN and CO ligands coordinated to iron. These spectroscopic fingerprints serve as sensitive probes for the intrinsic electronic structure of the metal core and, indirectly, for the structural composition of the active site. In this study, density functional theory (DFT) was used to calculate vibrational frequencies, by focusing on the EPR‐silent intermediate states that contain divalent metal centers. By using the well‐characterized Ni‐C and Ni‐B states as references, we identified candidates for the Ni‐SIr, Ni‐SIa, and Ni‐R states by matching the predicted relative frequency shifts with experimental results. The Ni‐SIr and Ni‐SIa states feature a water molecule loosely bound to nickel and a formally vacant bridge. Both states are connected to each other through protonation equilibria; that is, in the Ni‐SIa state one of the terminal thiolates is protonated, whereas in Ni‐SIr this thiolate is unprotonated. For the reduced Ni‐R state two feasible models emerged: in one, H2 coordinates side‐on to nickel, and the second features a hydride bridge and a protonated thiolate. The Ni‐SU state remains elusive as no unequivocal correspondence between the experimental data and calculated frequencies of the models was found, thus indicating that a larger structural rearrangement might occur upon reduction from Ni‐A to Ni‐SU and that the bridging ligand might dissociate.
Three‐dimensional multidetector computed tomography versus conventional 2‐dimensional transesophageal echocardiography for annular sizing in transcatheter aortic valve replacement: Influence on postprocedural paravalvular aortic regurgitation
Authors: Hansson Nicolaj C. , Thuesen Leif , Hjortdal Vibeke E. , Leipsic Jonathon , Andersen Henning R. , Poulsen Steen H. , Webb John G. , Christiansen Evald H. , Rasmussen Lars E. , Krusell Lars R. , Terp Kim , Klaaborg Kaj E. , Tang Mariann , Lassen Jens F. , Bøtker Hans E. , Nørgaard Bjarne L. 
Published: May 2013

ObjectivesIn transcatheter aortic valve replacement (TAVR), the influence of aortic annular assessment with either multidetector computed tomography (MDCT) or conventional transesophageal echocardiography (TEE) on the incidence of postprocedural paravalvular aortic regurgitation (PAR) was evaluated.BackgroundPAR remains a major limitation in TAVR. Appropriate selection of transcatheter heart valve (THV) size is crucial to prevent PAR.MethodsOutcomes following TAVR with a balloon‐expandable THV were compared in two retrospective cohorts identified according to whether THV size selection was based on TEE (study group 1, n = 80) or MDCT (study group 2, n = 58).ResultsThe two study groups were comparable with regard to baseline clinical, risk score, and echocardiographic characteristics. The incidence of moderate/severe PAR was lower in study group 2 than in group 1, 8.6% versus 28.8% (P < 0.01). The difference between the THV nominal diameter and MDCT annular diameter was predictive of moderate/severe PAR (AUC 0.84; 95% CI: 0.72–0.92). Neither age, gender, body mass index, annular eccentricity index, aortic valve calcification nor the difference between the THV diameter and the TEE annular diameter predicted postprocedural PAR. Increased THV oversizing relative to the MDCT mean annular diameter was associated with reduced severity of PAR. No difference in perprocedural complications between two study groups was observed.ConclusionMDCT‐based annular sizing in TAVR significantly reduces postprocedural PAR, and THV oversizing appears pivotal in this aspect. Further delineation of the optimal degree of THV oversizing is needed. © 2013 Wiley Periodicals, Inc.
Catheterization‐based intervention in low birth weight infants less than 2.5 kg with acute and long‐term outcome
Authors: Kobayashi Daisuke , Sallaam Salaam , Aggarwal Sanjeev , Singh Harinder R. , Turner Daniel R. , Forbes Thomas J. , Gowda Srinath T. 
Published: May 2013

BackgroundThe number of low birth weight infants with congenital heart disease is increasing and catheterizations may have an increased risk for mortality and morbidity.ObjectivesWe investigate the outcome and complications of cardiac catheterizations in infants weighing < 2.5 kg.MethodsRetrospective review of catheterization records from 1995 to 2010 in infants weighing < 2.5 kg. The demographics, procedure, outcome, and follow‐up data were collected.ResultsOf 101 catheterizations performed in 88 patients, 45 (45%) catheterizations were interventional. Balloon atrial septostomy (n = 23), pulmonary valvuloplasty (14), aortic valvuloplasty (4), stent placement (3), balloon angioplasty (2), and temporary pacemaker insertion (1) were successfully performed. Balloon atrial septostomy was performed with pulmonary or aortic valvuloplasty in two catheterizations. Infants < 2.5 kg had higher significant adverse event rate that those 2.5−3.5 kg (13% versus 6.6%, P < 0.05). No procedural death was noted. Significant adverse events (n = 13) included cardiopulmonary resuscitation three, vascular six, arrhythmia three, and apnea requiring intubation one. On median follow‐up of 3 years (0.03 to 14), n = 69, mortality rate was 36%. In six patients with valvar pulmonary stenosis with median follow‐up of 6 years (0.75–13), four (67%) did not require re‐intervention. Of two patients with aortic stenosis, one did not require repeat intervention for 6 years (last follow‐up).ConclusionInterventional catheterization is feasible with low procedural morbidity and mortality in high risk infants < 2.5 kg. Catheterization primarily serves as a palliative procedure to stabilize infants for definitive treatment. Balloon valvuloplasty may be effective for isolated valvar pulmonary stenosis in infants < 2.5 kg. © 2013 Wiley Periodicals, Inc.
A pathologic study of explanted parachute devices from seven heart failure patients following percutaneous ventricular restoration
Authors: Ladich Elena , Otsuka Fumiyuki , Virmani Renu 
Published: May 2013

ObjectivesWe sought to evaluate the pathologic findings of the percutaneous Parachute device implanted in patients with severe heart failure (HF).BackgroundCurrently, most treatments of HF rest on optimal medical therapy with adjunctive interventional or surgical palliative treatments. One such treatment is the Parachute device, which partitions the left ventricle excluding the scarred myocardium from functioning myocardium, and has shown promise in clinical studies.MethodsWe have examined histopathologically seven cases [six males (age range 43–74 years; mean 56 years) and one female (55 years)] of Parachute device that were either retrieved at autopsy (n = 4) or during transplantation (n = 3); implant duration, 15–1,533 days.ResultsThree patients died of cardiac causes and none died from complications. Histologic early changes (<30 days, n = 1) included adherent thrombus, with focal neutrophil infiltration and degenerating inflammatory cells. Over time (31–300 days, n = 4), there was organized thrombus and development of neoendocardial thickening especially at the free‐edge of the device and its contact with the adjacent endocardium while the base of the device showed varying degrees of fibrin thrombus. The greatest organization of thrombus was observed in devices removed at >300 days (680 and 1533 days); both had fractures of the foot along with strut fracture and one had tearing of the expanded polytetrafluoroethylene.ConclusionsThe percutaneous Parachute device appears as a promising adjunctive treatment for patients suffering from severe HF. The pathologic changes are those of organizing thrombus with and without inflammation with minor complications of foot and strut fracture. © 2013 Wiley Periodicals, Inc.
Estimation of oxygen consumption in elderly patients with aortic stenosis
Authors: Gertz Zachary M. , McCauley Brian D. , Raina Amresh , O'Donnell William , Shellenberger Charlene , Willhide Judi , Forfia Paul R. , Herrmann Howard C. 
Published: May 2013

BackgroundInvasive evaluation of aortic stenosis requires measuring cardiac output. With the Fick equation, a measure of oxygen consumption (VO2) is required. Standard equations for estimating VO2 were derived in younger and healthier populations than the ones referred for possible transcatheter aortic valve replacement. The goal of this study was to determine the best method of estimating VO2 in elderly patients with aortic stenosis.MethodsWe directly measured VO2 in elderly patients undergoing invasive assessment of aortic stenosis. We compared standard equations estimating VO2 and two prespecified hypothesized equations for VO2 to determine which was most accurate. We also examined the subgroup of patients with low flow.ResultsAmong 51 patients, aged 80–97 years, the mean VO2 was 198 mL/min. Using 125*body surface area (BSA) to estimate VO2 the average error was 35 mL/min, and 67% of values were within 25% of the true value. Using 3*Weight to estimate VO2, those numbers were 29 mL/min and 65%. The hypothesized equations did better: 100*BSA had error of −12 mL/min and 90% within 25% of measured VO2; for 2.5*Weight it was −9 mL/min and 84%. Among the 20 patients with low flow, hypothesized equations performed best. Using 2.5*Weight and 100*BSA there were 90% and 85% within 25% of measured VO2, respectively, compared to 55% and 75% when 3*Weight and 125*BSA were used. Weight and BSA were the only independent predictors of VO2.ConclusionsWhen estimating VO2 in an elderly population with aortic stenosis, the best equations are 2.5*Weight and 100*BSA. © 2013 Wiley Periodicals, Inc.
Transcatheter trans‐septal antegrade closure of muscular ventricular septal defects in young children
Authors: Koneti Nageswara Rao , Verma Sudeep , Bakhru Shweta , Vadlamudi Karunakar , Kathare Pallavi , Penumatsa Raghava Raju , Qureshi Shakeel 
Published: May 2013

BackgroundSurgical or transcatheter closure of muscular ventricular septal defects (mVSDs) in young children may be technically challenging and associated with significant complications.ObjectiveTo assess the feasibility of trans‐septal antegrade closure of mVSD in a selected subset of young children.MethodsThis is a prospective study from a single centre from July 2011 to March 2013. Nine infants and children with single or multiple mVSDs were included in the study. The median age and weight were 6 months (range 4–18 months) and 4.5 kg (range 3.8–6.2 kg), respectively. Trans‐femoral trans‐septal antegrade technique was used in eight children. One child was excluded from the study because of abnormally tortuous anatomy of both the femoral veins and subsequently underwent VSD device closure by the trans‐jugular approach. The follow‐up evaluation included chest X‐ray, ECG, and echocardiogram at 1 month, 3 months, 6 months, and 1 year.ResultsThe defects were closed successfully in all eight patients using Amplatzer mVSD device in 5 and Amplatzer Duct Occluder II in 3. Moderate mitral regurgitation due to entrapment of the anterior mitral leaflet occurred in one patient with a posteriorly located mVSD, necessitating removal of the device, and surgical closure of the mVSD. The small additional residual mVSD in one other patient closed spontaneously during the follow‐up.ConclusionsTranscatheter trans‐septal antegrade closure of mVSD in young children is technically feasible and merits further consideration. Symptomatic relief in multiple mVSD can be achieved after closing larger defects. © 2013 Wiley Periodicals, Inc.
Age, glomerular filtration rate, ejection fraction, and the AGEF score predict contrast‐induced nephropathy in patients with acute myocardial infarction undergoing primary percutaneous coronary intervention
Authors: Andò Giuseppe , Morabito Gaetano , de Gregorio Cesare , Trio Olimpia , Saporito Francesco , Oreto Giuseppe 
Published: May 2013

BackgroundIn patients undergoing primary percutaneous coronary interventions (PCI) for ST‐segment elevation myocardial infarction (STEMI), the occurrence of Contrast‐Induced Nephropathy (CIN) has a pronounced impact both on morbidity and mortality. We investigated the variables associated with CIN development in 481 consecutive patients with STEMI undergoing primary PCI and evaluated the predictive value of a 3‐variable clinical risk score (the AGEF score) based on age, left ventricular ejection fraction (EF), and estimated glomerular filtration rate (eGFR).MethodsCIN was defined as an absolute increase in serum creatinine ≥0.5 mg/dL or an increase ≥25% from baseline within 72 hr. AGEF score was calculated by adding 1 point to the Age/EF(%) ratio if the eGFR was <60 mL/min per 1.73 m2.ResultsOverall, the incidence of CIN was 5.2%. In‐hospital mortality was higher in patients with CIN than in those without (16% Vs 1.3%, P = 0.001). At multivariate analysis age (OR 1.06, P = 0.042), eGFR (OR 0.95, P = 0.001), EF (OR 0.94, P = 0.007) and post‐procedural TIMI flow grade (OR 0.43, P = 0.045) were independent predictors of CIN. AGEF score was an accurate (OR 5.19, P < 0.001, AUC 0.88) and calibrated (Hosmer‐Lemeshow χ2 = 10.25, P = 0.25) predictor of CIN.ConclusionsAdvanced age, depressed EF, and reduced eGFR are independent predictors of CIN development after primary PCI for STEMI. The preprocedural individual patient risk can be clinically assessed with the calculation of the AGEF score, which is based on such readily available parameters. © 2013 Wiley Periodicals, Inc.
Reversal of ischemia of donor artery myocardium after recanalization of a chronic total occlusion
Authors: Sachdeva Rajesh , Agrawal Mayank , Flynn Shawn E. , Werner Gerald S. , Uretsky Barry F. 
Published: May 2013

BackgroundCase reports have shown that an intermediate stenosis in the donor artery collateralizing the myocardium of a chronic total occlusion (CTO) can produce an ischemic fractional flow reserve (FFR) value which may revert to non‐ischemic with CTO revascularization.MethodsA consecutive series of patients with severe angina in which a donor artery with intermediate stenosis (30–70%) had FFR measured before and after successful CTO recanalization were studied.ResultsFourteen of 50 consecutive CTO patients with successful PCI fulfilled the study criteria. Eight had CTO of the right coronary artery (RCA), three circumflex (LCx), and three RCA and LCx. Left anterior descending artery was the donor artery in 13 and LCx in 1 patient. Of nine donor ischemic FFR patient's pre‐PCI, six reverted to non‐ischemic (FFR pre‐PCI 0.76 ± 0.04 and 0.86 ± 0.03 post‐PCI). Five patients had normal FFR in the donor artery pre‐ and post‐CTO PCI.ConclusionsIn patients with a CTO and an intermediate donor artery stenosis, the frequency of ischemia in the donor artery territory is relatively high and often normalized by successful CTO recanalization. These data recommend recanalizing the CTO first whenever possible as a preferred therapeutic strategy to avoid the need for PCI to the donor artery or multivessel bypass surgery. © 2013 Wiley Periodicals, Inc.
Bisguanidines with Biphenyl, Binaphthyl, and Bipyridyl Cores: Proton‐Sponge Properties and Coordination Chemistry
Authors: Maronna Astrid , Hübner Olaf , Enders Markus , Kaifer Elisabeth , Himmel Hans‐Jörg 
Published: May 2013

AbstractHerein, we report on the synthesis, protonation, and coordination chemistry of chelating guanidine ligands with biphenyl, binaphthyl, and bipyridyl backbones. The ligands are shown to be proton sponges, and this protonation was studied experimentally and by using quantum‐chemical calculations. Group 10 metal (Ni, Pd, and Pt) complexes with different metal/ligand ratios were synthesized. In the case of the bipyridyl systems, coordination occurs exclusively at the pyridine N atoms, as opposed to protonation. The spin‐density distribution and the magnetism were evaluated for a series of paramagnetic NiII complexes with the aid of paramagnetic NMR spectroscopic studies in alliance with quantum‐chemical calculations and magnetic (SQUID) measurements. Through direct delocalization from the singly occupied molecular orbitals (SOMOs), a significant amount of spin density is placed on the guanidinyl groups, and spin polarization also transports spin density onto the aromatic backbone.
X‐Ray Photoelectron Spectroscopy for Characterization of Bionanocomposite Functional Materials for Energy‐Harvesting Technologies
Authors: Artyushkova Kateryna , Atanassov Plamen 
Published: May 2013

AbstractThe analysis of hybrid multicomponent bioorganic and bioinorganic composite materials related to energy technologies by using X‐ray photoelectron spectroscopy is discussed. The approaches and considerations of overcoming the difficulties of analyzing hybrid multicomponent materials are demonstrated for different types of materials used in bioenzyme fuel cells, that is, enzyme immobilization in a hybrid inorganic–organic matrix, analysis of peptide binding and structure in the mediation of silica nanoparticle formation, analysis of enzyme–polymeric multilayered architectures obtained through layer‐by‐layer assembly, and study of the mechanism of electropolymerization. Thorough optimization of experimental design through analysis of an adequate set of reference materials, relevant timescales of sample preparation and X‐ray exposure, careful peak decomposition and cross‐correlation between elemental speciation, results in a detailed understanding of the chemistry of nanocomposite constituents and interactions between them. The methodology presented and examples discussed are of significant importance to the scientific and engineering communities focused on the immobilization of enzymes, proteins, peptides, and other large biological molecules on solid substrates.
Manta Matcher: automated photographic identification of manta rays using keypoint features
Authors: Town Christopher , Marshall Andrea , Sethasathien Nutthaporn 
Published: May 2013

AbstractFor species which bear unique markings, such as natural spot patterning, field work has become increasingly more reliant on visual identification to recognize and catalog particular specimens or to monitor individuals within populations. While many species of interest exhibit characteristic markings that in principle allow individuals to be identified from photographs, scientists are often faced with the task of matching observations against databases of hundreds or thousands of images. We present a novel technique for automated identification of manta rays (Manta alfredi and Manta birostris) by means of a pattern‐matching algorithm applied to images of their ventral surface area. Automated visual identification has recently been developed for several species. However, such methods are typically limited to animals that can be photographed above water, or whose markings exhibit high contrast and appear in regular constellations. While manta rays bear natural patterning across their ventral surface, these patterns vary greatly in their size, shape, contrast, and spatial distribution. Our method is the first to have proven successful at achieving high matching accuracies on a large corpus of manta ray images taken under challenging underwater conditions. Our method is based on automated extraction and matching of keypoint features using the Scale‐Invariant Feature Transform (SIFT) algorithm. In order to cope with the considerable variation in quality of underwater photographs, we also incorporate preprocessing and image enhancement steps. Furthermore, we use a novel pattern‐matching approach that results in better accuracy than the standard SIFT approach and other alternative methods. We present quantitative evaluation results on a data set of 720 images of manta rays taken under widely different conditions. We describe a novel automated pattern representation and matching method that can be used to identify individual manta rays from photographs. The method has been incorporated into a website (mantamatcher.org) which will serve as a global resource for ecological and conservation research. It will allow researchers to manage and track sightings data to establish important life‐history parameters as well as determine other ecological data such as abundance, range, movement patterns, and structure of manta ray populations across the world.
Activation of E–H and E–E (E = S, O) Bonds by Heterobimetallic Zr/Co Complexes: Evidence for Both One‐ and Two‐Electron Processes
Authors: Napoline J. Wesley , Krogman Jeremy P. , Shi Rena , Kuppuswamy Subramaniam , Bezpalko Mark W. , Foxman Bruce M. , Thomas Christine M. 
Published: May 2013

AbstractThe reactivity of the reduced ZrIIICo0 heterobimetallic complex [(thf)Zr(MesNPiPr2)3CoN2] (1a) towards O–H, S–H, S–S, and O–O bonds has been investigated. Complex 1a reacts readily with PhOH, EtOH, and H2O to generate the one‐electron‐oxidized complexes [(RO)Zr(MesNPiPr2)3CoN2] [R = Et (2), Ph (3), H (4)]. In contrast, PhSH and PhS–SPh react by means of overall two‐electron processes to form [(η2‐MesNPiPr2)Zr(μ‐SPh)(MesNPiPr2)2Co(SPh)] (5a). Addition of stoichiometric diethyl peroxide to 1a generates 2, but further equivalents lead to the two‐electron oxidized product [(EtO)Zr(MesNPiPr2)3Co(OEt)] (6). More sterically hindered peroxides such as dicumyl peroxide or di‐tert‐butyl peroxide do not react with 1a under ambient conditions, but upon photolysis, di‐tert‐butyl peroxide reacts with 1a to form [(tBuO)Zr(MesNPiPr2)3CoN2] (7). These results imply that an inner‐sphere electron‐transfer process is occurring at the Zr site of 1a upon treatment with these chalcogen‐based substrates, and a dissociative electron‐transfer mechanism is proposed.