bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Role of the Interaction Frame in the Theoretical Description of Solid Effect Dynamic Nuclear Polarization
Authors: Kwiatkowski Grzegorz , Karabanov Alexander , Köckenberger Walter 
Published: February 2014

AbstractThe enhancement of the nuclear spin polarization generated by dynamic nuclear polarization depends on two competing processes: the perturbation of the thermal equilibrium by the applied microwave field and the tendency of relaxation processes to re‐establish the thermal state. Hence, it is important to correctly incorporate relaxation processes in the theoretical description of dynamic nuclear polarization to obtain meaningful simulations. A difficulty arises in the choice of the correct interaction frame when building an appropriate relaxation superoperator. In the Zeeman frame, the rate constants introduced to define longitudinal and transverse relaxation can become mixed if the non‐secular part of the hyperfine interaction between an electron in a paramagnetic centre and the nuclear spins is strong. Deriving the relaxation superoperator in the interaction frame that is defined by the eigenbasis of the stationary Hamiltonian eliminates this issue. However, when using this strategy, not all the non‐secular terms arising in a relaxation model based on local magnetic field fluctuations are taken properly into account if dipolar interactions between nuclear spins dominate over hyperfine interactions. An analytical treatment of this problem is presented that is corroborated by a set of numerical simulations focussing on the case of solid effect dynamic nuclear polarization. The advantage and possible errors arising when using either of the two strategies are briefly summarised and discussed.
Growth evaluation method by live imaging of Daphnia magna and its application to the estimation of an insect growth regulator
Authors: Suzuki Akiko , Kato Yasuhiko , Matsuura Tomoaki , Watanabe Hajime 
Published: February 2014

ABSTRACTThe zooplankton Daphnia magna has been widely used as a test organism to assess the toxicity of chemical substances because of its important position in aquatic ecology and its ease of handling. Among the various endpoints for toxicity evaluation, growth rate is one of the most critical and many studies have been conducted. However, measurement of growth rate was time‐consuming and not an ideal endpoint in terms of screening. In this study, we demonstrated a live imaging method to monitor the growth of daphnids by area measurement. In this method, daphnid images were directly obtained from a swimming chamber and these images were processed for the evaluation of growth. The reliability of this method was confirmed by comparison with the conventional dry weight method of the same animals. The body area of daphnids using this method showed a strong correlation with the dry weight method, with R2 = 0.930. In addition, we quantified the effect of a toxicant, fenoxycarb, on the growth of the animal. Fenoxycarb concentrations of 0, 0.027, 0.27 and 2.7 µg l–1 were tested and their effects on growth were estimated by the live imaging method. In the toxicity test, the area of daphnids decreased significantly with increasing fenoxycarb concentration. These results indicate that the present live imaging method is a reliable approach for daphnid toxicity testing. This method is promising for high‐throughput Daphnia toxicity tests and real‐time individual observations. Copyright © 2014 John Wiley & Sons, Ltd.
Predictors of Excess Mortality After Fracture: A Population-Based Cohort Study
Authors: Melton L Joseph , Atkinson Elizabeth J , Sauver Jennifer L St. , Achenbach Sara J , Therneau Terry M , Rocca Walter A , Amin Shreyasee 
Published: February 2014

ABSTRACT

To determine the extent to which excess mortality after fractures attributable to particular causes at specific skeletal sites can be predicted using data about all medical diagnoses, we conducted a historical cohort study among 1991 Olmsted County, Minnesota, residents aged ≥50 years who experienced any fracture in 1989 to 1991 and who were followed passively for up to 22 years for death from any cause. We used a machine learning approach, gradient boosting machine (GBM) modeling, to determine whether the comorbid conditions present at the time of fracture and those that arose subsequently could, in aggregate, identify patients at the greatest increased risk of death. During 21,867 person-years of follow-up, 1245 deaths were observed when 1061 were expected (standardized mortality ratio, 1.2; 95% confidence interval [CI] 1.1–1.2). Patients presented with a median history of 26 comorbid conditions each as assessed by the Clinical Classification Software system and 57 each over the total duration of follow-up. Using all available information, the excess deaths could be predicted with good accuracy (c-index ≥0.80) in 89% of the GBM models built for patients with different types of fracture; in one-third of the models, the c-index was ≥0.90. The conditions most prominent in the GBM prediction models were also reflected in the specific causes of death that were elevated, suggesting the influence of confounding on the relationship. However, the predominant comorbid conditions were mainly those responsible for mortality in the general population, rather than the specific diseases most closely associated with secondary osteoporosis. To reduce long-term deaths in the fracture population as a whole, a more general approach to the fracture patient is indicated. © 2014 American Society for Bone and Mineral Research.
Effects of Odanacatib on the Radius and Tibia of Postmenopausal Women: Improvements in Bone Geometry, Microarchitecture, and Estimated Bone Strength
Authors: Cheung Angela M , Majumdar Sharmila , Brixen Kim , Chapurlat Roland , Fuerst Thomas , Engelke Klaus , Dardzinski Bernard , Cabal Antonio , Verbruggen Nadia , Ather Shabana , Rosenberg Elizabeth , de Papp Anne E 
Published: February 2014

ABSTRACT

The cathepsin K inhibitor odanacatib (ODN), currently in phase 3 development for postmenopausal osteoporosis, has a novel mechanism of action that reduces bone resorption while maintaining bone formation. In phase 2 studies, odanacatib increased areal bone mineral density (aBMD) at the lumbar spine and total hip progressively over 5 years. To determine the effects of ODN on cortical and trabecular bone and estimate changes in bone strength, we conducted a randomized, double-blind, placebo-controlled trial, using both quantitative computed tomography (QCT) and high-resolution peripheral (HR-p)QCT. In previously published results, odanacatib was superior to placebo with respect to increases in trabecular volumetric BMD (vBMD) and estimated compressive strength at the spine, and integral and trabecular vBMD and estimated strength at the hip. Here, we report the results of HR-pQCT assessment. A total of 214 postmenopausal women (mean age 64.0 ± 6.8 years and baseline lumbar spine T-score –1.81 ± 0.83) were randomized to oral ODN 50 mg or placebo, weekly for 2 years. With ODN, significant increases from baseline in total vBMD occurred at the distal radius and tibia. Treatment differences from placebo were also significant (3.84% and 2.63% for radius and tibia, respectively). At both sites, significant differences from placebo were also found in trabecular vBMD, cortical vBMD, cortical thickness, cortical area, and strength (failure load) estimated using finite element analysis of HR-pQCT scans (treatment differences at radius and tibia = 2.64% and 2.66%). At the distal radius, odanacatib significantly improved trabecular thickness and bone volume/total volume (BV/TV) versus placebo. At a more proximal radial site, odanacatib attenuated the increase in cortical porosity found with placebo (treatment difference = –7.7%, p = 0.066). At the distal tibia, odanacatib significantly improved trabecular number, separation, and BV/TV versus placebo. Safety and tolerability were similar between treatment groups. In conclusion, odanacatib increased cortical and trabecular density, cortical thickness, aspects of trabecular microarchitecture, and estimated strength at the distal radius and distal tibia compared with placebo. © 2014 American Society for Bone and Mineral Research
High-Resolution Genome Screen for Bone Mineral Density in Heterogeneous Stock Rat
Authors: Alam Imranul , Koller Daniel L , Cañete Toni , Blázquez Gloria , López-Aumatell Regina , Martínez-Membrives Esther , Díaz-Morán Sira , Tobeña Adolf , Fernández-Teruel Alberto , Stridh Pernilla , Diez Margarita , Olsson Tomas , Johannesson Martina , Baud Amelie , Econs Michael J , Foroud Tatiana 
Published: February 2014

ABSTRACT

We previously demonstrated that skeletal mass, structure, and biomechanical properties vary considerably in heterogeneous stock (HS) rat strains. In addition, we observed strong heritability for several of these skeletal phenotypes in the HS rat model, suggesting that it represents a unique genetic resource for dissecting the complex genetics underlying bone fragility. The purpose of this study was to identify and localize genes associated with bone mineral density in HS rats. We measured bone phenotypes from 1524 adult male and female HS rats between 17 and 20 weeks of age. Phenotypes included dual-energy X-ray absorptiometry (DXA) measurements for bone mineral content and areal bone mineral density (aBMD) for femur and lumbar spine (L3–L5), and volumetric BMD measurements by CT for the midshaft and distal femur, femur neck, and fifth lumbar vertebra (L5). A total of 70,000 polymorphic single-nucleotide polymorphisms (SNPs) distributed throughout the genome were selected from genotypes obtained from the Affymetrix rat custom SNPs array for the HS rat population. These SNPs spanned the HS rat genome with a mean linkage disequilibrium coefficient between neighboring SNPs of 0.95. Haplotypes were estimated across the entire genome for each rat using a multipoint haplotype reconstruction method, which calculates the probability of descent for each genotyped locus from each of the eight founder HS strains. The haplotypes were tested for association with each bone density phenotype via a mixed model with covariate adjustment. We identified quantitative trait loci (QTLs) for BMD phenotypes on chromosomes 2, 9, 10, and 13 meeting a conservative genomewide empiric significance threshold (false discovery rate [FDR] = 5%; p &lt; 3 × 10−6). Importantly, most QTLs were localized to very small genomic regions (1–3 megabases [Mb]), allowing us to identify a narrow set of potential candidate genes including both novel genes and genes previously shown to have roles in skeletal development and homeostasis. © 2014 American Society for Bone and Mineral Research.
Cortical Bone Assessed With Clinical Computed Tomography at the Proximal Femur
Authors: Johannesdottir Fjola , Turmezei Tom , Poole Kenneth ES 
Published: February 2014

ABSTRACT

Hip fractures are the most serious of all fragility fractures in older people of both sexes. Trips, stumbles, and falls result in fractures of the femoral neck or trochanter, and the incidence of these two common fractures is increasing worldwide as populations age. Although clinical risk factors and chance are important in causation, the ability of a femur to resist fracture also depends on the size and spatial distribution of the bone, its intrinsic material properties, and the loads applied. Over the past two decades, clinical quantitative computed tomography (QCT) studies of living volunteers have provided insight into how the femur changes with advancing age to leave older men and women at increased risk of hip fractures. In this review, we focus on patterns of cortical bone loss associated with hip fracture, age-related changes in cortical bone, and the effects of drugs used to treat osteoporosis. There are several methodologies available to measure cortical bone in vivo using QCT. Most techniques quantify bone density (g/cm3), mass (g), and thickness (mm) in selected, predefined or “traditional” regions of interest such as the “femoral neck” or “total hip” region. A recent alternative approach termed “computational anatomy,” uses parametric methods to identify systematic differences, before displaying statistically significant regions as color-scaled maps of density, mass, or thickness on or within a representative femur model. This review will highlight discoveries made using both traditional and computational anatomy methods, focusing on cortical bone of the proximal femur. © 2014 American Society for Bone and Mineral Research.
Endotracheal tube biofilm and ventilator‐associated pneumonia with mechanical ventilation
Authors: De Souza Paula Regina , De Andrade Denise , Cabral Danielle Bezerra , Watanabe Evandro 
Published: February 2014

ABSTRACTObjective: To analyze biofilm on internal and external surfaces of endotracheal tubes after their use in critical care patients, and to produce evidence of association between use of the tube, presence of biofilm, and the occurrence of pneumonia. Methods: This was a clinical study performed at the Intensive Care Unit of an emergency hospital in the interior of São Paulo state, Brazil. Data collection involved 30 endotracheal tubes used on adult patients for a period of ≥48 h of mechanical ventilation for scanning electron microscopy. Results: Analysis of the biofilm on the 30 tubes by scanning electron microscopy showed various abiotic and biotic structures, predominately on the internal surface, such as: fibrin network, erythrocytes, leukocytes, cocci, bacilli, and molds, among others. The intubation period of the endotracheal tube for ≥8 days represented one of the risk factors for ventilator‐associated pneumonia (RR 7.41, P < 0.001). Conclusions: The presence of the endotracheal tube permits microbial colonization, overall contributing to the development of biofilm and the occurrence of pneumonia. Microsc. Res. Tech. 77:305–312, 2014. © 2014 Wiley Periodicals, Inc.
A first Glimpse at the genome of the Baikalian amphipod Eulimnogammarus verrucosus
Authors: Rivarola‐Duarte Lorena , Otto Christian , Jühling Frank , Schreiber Stephan , Bedulina Daria , Jakob Lena , Gurkov Anton , Axenov‐Gribanov Denis , Sahyoun Abdullah H. , Lucassen Magnus , Hackermüller Jörg , Hoffmann Steve , Sartoris Franz , Pörtner Hans‐Otto , Timofeyev Maxim , Luckenbach Till , Stadler Peter F. 
Published: February 2014

ABSTRACTEulimnogammarus verrucosus is an amphipod endemic to the unique ecosystem of Lake Baikal and serves as an emerging model in ecotoxicological studies. We report here on a survey sequencing of its genome as a first step to establish sequence resources for this species. From a single lane of paired‐end sequencing data, we estimated the genome size as nearly 10 Gb and we obtained an overview of the repeat content. At least two‐thirds of the genome are non‐unique DNA, and a third of the genomic DNA is composed of just five families of repetitive elements, including low‐complexity sequences. Attempts to use off‐the‐shelf assembly tools failed on the available low‐coverage data both before and after removal of highly repetitive components. Using a seed‐based approach we nevertheless assembled short contigs covering 33 pre‐microRNAs and the homeodomain‐containing exon of nine Hox genes. The absence of clear evidence for paralogs implies that a genome duplication did not contribute to the large genome size. We furthermore report the assembly of the mitochondrial genome using a new, guided “crystallization” procedure. The initial results presented here set the stage for a more complete sequencing and analysis of this large genome. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 177–189, 2014. © 2014 Wiley Periodicals, Inc.
New frontiers in the evolution of fin development
Authors: Freitas Renata , Gómez‐Skarmeta José Luis , Rodrigues Pedro Nuno 
Published: February 2014

ABSTRACTThe locomotory appendages of vertebrates have undergone significant changes during evolution, which likely promoted a wide range of adaptive strategies. These appendages first evolved as unpaired finfolds in the dorsal midline of early chordates, more than 500 million years ago. Later on, during vertebrates' radiation, two sets of locomotory appendages emerged, developing from both sides of the latero‐ventral body wall. The morphology of these paired fins in fishes at different phylogenetic positions suggests an evolutionary tendency for increasing elaboration of the endoskeleton and concomitant reduction of the distal dermoskeleton. This evolutionary process culminated with the origin of limbs in the lineages leading to tetrapods. The developmental programs responsible for the evolution of vertebrate appendages have been a major topic for evolutionary developmental biology recently. Gene expression comparisons performed in chordates explored how these mechanisms were transferred from a midline to latero‐ventral position. On another front, gene function assays have begun to test classical hypotheses concerning the transition from fish fins to tetrapod limbs. In this review, we highlight these recent findings on the evolution of vertebrate fin development. First, we discuss new perspectives on the transition from midline to paired appendages focus on (i) origin and molecular regionalization of the lateral plate mesoderm and (ii) novel ectodermic competency zones for fin induction. Next, we review recent work exploring how tetrapod limbs evolved from fish fins, considering (i) molecular and structural changes in the distal ectoderm of fins and (ii) modulation of 5′HoxD transcription during fin endoskeleton development. J. Exp. Zool. (Mol. Dev. Evol.) 322B: 540–552, 2014. © 2014 Wiley Periodicals, Inc.
Volume analyzer SYNAPSE VINCENT for liver analysis
Authors: Ohshima Shunsuke 
Published: February 2014

Abstract In recent years, there has been an active movement to ensure the greater safety of actual surgeries, by simulating it preoperatively with the use of three‐dimensional image visualization technologies. Along with this movement, the Ministry of Health, Labour and Welfare has named “Image‐supported navigation in hepatectomy” as part of advanced medical techniques. This method aims to improve the safety during a surgery by calculating the volume of the liver dominated by each blood vessel or simulating, prior to surgery, the volume of resection zone or the remaining liver volume. These calculations and simulations are carried out using the three‐dimensional images produced by extractions of the liver, vascular and tumor regions from the computed tomography images, which were collected using the tomography apparatus prior to hepatectomy. In order to facilitate the achievement of such preoperative simulations, the volume analyzer SYNAPSE VINCENT (VINCENT, hereafter) by Fujifilm, in its Liver Analysis Application, comes equipped with unique features. This paper will introduce the technologies behind those unique features and provide a direction for future research and developments.
Usefulness of multi‐3‐dimensional computed tomograms fused with multiplanar reconstruction images and peroral cholangioscopy findings in hilar cholangiocarcinoma
Authors: Nagakawa Yuichi , Kasuya Kazuhiko , Bunso Kyo , Hosokawa Yuichi , Kuwabara Hiroshi , Nakagima Tetsushi , Osakabe Hiroaki , Tsuchiya Takayoshi , Itoi Takao , Tsuchida Akihiko 
Published: February 2014

Abstract Multiplanar reconstruction (MPR) images are used for assessing horizontal and vertical extent of hilar cholangiocarcinoma, while peroral cholangioscopy (POCS) is used for diagnosing ductal spread and mapping biopsy. We fused conventional 3‐dimensional computed tomography (3DCT) with MPR images and POCS findings for preoperative assessment of cholangiocarcinoma. The extent of cancer was assessed using MPR images, which were plotted and fused onto 3DCT cholangiography. In addition, the results of mapping biopsy performed under POCS were marked on virtual endoscopic imaging and transferred onto a 3DCT image. Once an angiographic CT image was fused, a multi‐3DCT image was created. The incision line was determined based on these images. Multi‐3DCT images were created for 13 patients with hilar cholangiocarcinoma. Of 10 patients who underwent POCS, superficial spread was observed in two. Resection was performed in 12 patients. In two cases, the cut end of the intrahepatic bile duct was positive, resulting in 83.3% diagnostic accuracy for horizontal spread. In all patients, the estimated number of bile ducts was the same as the number of the actual resections. R0 resection was achieved in 10 patients (83.3%). Multi‐3DCT imaging proved useful in diagnosing longitudinal ductal spread of hilar cholangiocarcinoma.
Model order reduction applied to the numerical study of electrical motor based on POD method taking into account rotation movement
Authors: Henneron T. , Clénet S. 
Published: February 2014

SUMMARYIn order to reduce the computation time and the memory resources required to solve an electromagnetic field problem, model order reduction approaches can be applied to reduce the size of the linear equation system obtained after discretisation. In the literature, the POD is widely used in engineering. In this paper, we propose to apply the POD in the case of a finite element problem accounting for the movement. The efficiency of this method is evaluated by considering an electrical motor and by comparing with the full model in terms of computational time and accuracy. Copyright © 2014 John Wiley & Sons, Ltd.
The use of synoptic climatology with general circulation model output over New Zealand
Authors: Parsons Simon , McDonald Adrian J. , Renwick James A. 
Published: February 2014

ABSTRACTA cluster analysis‐based synoptic classification scheme, known as the Kidson types, was applied to reanalyses and Coupled Model Inter‐comparison Project phase 3 (CMIP3) general circulation model (GCM) output over New Zealand to identify the potential for future changes in regional circulation. Results indicate that a number of GCM 20th century control runs reproduce the type frequencies observed in reanalysis data. Application to future scenario runs for the periods 2046–2065 and 2081–2100 displays little variation in the annual frequency of the synoptic types relative to the 20th century, especially when uncertainty associated with the model ensemble is considered. This is surprising in the context of previous work on possible future movements in jet position and subsequent impacts on weather patterns. A sensitivity analysis that mimics the movement of the jet position was performed, revealing that the annual type frequencies are relatively insensitive to change. To determine whether this is a problem with the synoptic typing scheme, a correlation‐based classification technique was also used, but showed similar results. This work highlights issues with applying synoptic classification schemes to GCM output and indicates that if such schemes are to be used they should be designed and tested with this application in mind.