bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attenuation map estimation with SPECT emission data only
Authors: Yan Yan , Zeng Gengsheng Lawrence 
Published: August 2009

AbstractQuantitative single‐photon emission computed tomography can be well achieved if photon attenuation is taken into account in the reconstruction process. Using a transmission scan is a common approach. A dramatic simplification could be made if the attenuation map could be obtained from the emission data. In this article, we propose a new method to estimate the attenuation map using the data consistency conditions of the attenuated Radon transform. It is based on deriving boundaries of the constant regions of the true attenuation map using an iterative algorithm. This new method is tested by Monte Carlo simulations with the attenuation and scattering effects. © 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 271–276, 2009
Contemporary technologies for 3D digitization of Maori and Pacific Island artifacts
Authors: Surendran Nanda K. , Xu Xun W. , Stead Oliver , Silyn‐Roberts Heather 
Published: August 2009

AbstractThree‐dimensional (3D) digitization is a key aspect in the preservation and exhibition of museum artifacts. The objective of this article is to investigate contemporary technologies for creating accurate 3D digital models of artifacts from the Maori and Pacific heritage and to establish a generic digitization methodology so that the 3D models can be archived and exhibited both over the internet and within museum displays. This process involves procedures for selecting artifacts that are suitable for laser scanning and then setting up the artifact for scanning. This is followed by the actual scanning and postprocessing stages. To achieve this, the Polhemus FastSCAN laser scanner has been used to collect raw point cloud surface data from artifacts of various sizes, shapes, textures, colors, and materials. The article explains the generic steps developed for postprocessing of raw scan data in the form of a cloud of geometric data points to a completely rendered 3D model with colors mapped on to the model. These generic steps involve removal of background noise, enhancement of texture, filling of holes, merging of separate scans, and color mapping. The results from the scanning and postprocessing of a wahaika, (a Maori club‐like weapon) and a Polynesian stone pounder reveal that it is important to use a scanner that is flexible enough to capture all the surface information irrespective of the artifact's geometry, and one with the capability of capturing color information with high accuracy. © 2009 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 19, 244–259, 2009
Phosphorylation of PPP(S/T)P motif of the free LRP6 intracellular domain is not required to activate the Wnt/β‐catenin pathway and attenuate GSK3β activity
Authors: Beagle Brandon , Mi Kaihong , Johnson Gail V.W. 
Published: August 2009

AbstractThe canonical Wnt/β‐catenin signaling pathway plays a critical role in numerous physiological and pathological processes. LRP6 is an essential co‐receptor for Wnt/β‐catenin signaling; as transduction of the Wnt signal is strongly dependent upon GSK3β‐mediated phosphorylation of multiple PPP(S/T)P motifs within the membrane‐anchored LRP6 intracellular domain. Previously, we showed that the free LRP6 intracellular domain (LRP6‐ICD) can activate the Wnt/β‐catenin pathway in a β‐catenin and TCF/LEF‐1 dependent manner, as well as interact with and attenuate GSK3β activity. However, it is unknown if the ability of LRP6‐ICD to attenuate GSK3β activity and modulate activation of the Wnt/β‐catenin pathway requires phosphorylation of the LRP6‐ICD PPP(S/T)P motifs, in a manner similar to the membrane‐anchored LRP6 intracellular domain. Here we provide evidence that the LRP6‐ICD does not have to be phosphorylated at its PPP(S/T)P motif by GSK3β to stabilize endogenous cytosolic β‐catenin resulting in activation of TCF/LEF‐1 and the Wnt/β‐catenin pathway. LRP6‐ICD and a mutant in which all 5 PPP(S/T)P motifs were changed to PPP(A)P motifs equivalently interacted with and attenuated GSK3β activity in vitro, and both constructs inhibited the in situ GSK3β‐mediated phosphorylation of β‐catenin and tau to the same extent. These data indicate that the LRP6‐ICD attenuates GSK3β activity similar to other GSK3β binding proteins, and is not a result of it being a GSK3β substrate. Our findings suggest the functional and regulatory mechanisms governing the free LRP6‐ICD may be distinct from membrane‐anchored LRP6, and that release of the LRP6‐ICD may provide a complimentary signaling cascade capable of modulating Wnt‐dependent gene expression. J. Cell. Biochem. 108: 886–895, 2009. © 2009 Wiley‐Liss, Inc.
PI3K/AKT regulates aggrecan gene expression by modulating Sox9 expression and activity in nucleus pulposus cells of the intervertebral disc
Authors: Cheng Chin‐Chang , Uchiyama Yoshiyasu , Hiyama Akihiko , Gajghate Sachin , Shapiro Irving M. , Risbud Makarand V. 
Published: August 2009

AbstractThe goal of the investigation was to test the hypothesis that the phosphoinositide‐3 kinase (PI3K)/AKT signaling pathway regulates the expression of the major extracellular matrix component of the intervertebral disc, aggrecan, in nucleus pulposus cells. Primary rat nucleus pulposus cells were treated with PI3K inhibitor to measure changes in gene and protein expression. In addition, cells were transfected with various luciferase reporter plasmids to investigate mechanisms of regulation of aggrecan gene expression. We found that treatment of nucleus pulposus cells with a PI3K inhibitor, LY294002 resulted in decreased expression of aggrecan and a reduction in deposition of sulfated glycosaminoglycans. Moreover, pharmacological suppression or co‐expression of dominant negative (DN)‐PI3K or DN‐AKT resulted in downregulation of aggrecan promoter activity. Expression of constitutively active (CA)‐PI3K significantly induced aggrecan promoter activity. We observed that PI3K maintained Sox9 gene expression and activity: inhibition of PI3K/AKT resulted in decreased Sox9 expression, lowered promoter activity, and mediated a reduction in Sox9 transcriptional activity. PI3K effects were independent of phosphorylation status of C‐terminus transactivation domain (TAD) of Sox9. Finally, we noted that in nucleus pulposus cells, PI3K signaling controlled transactivation of p300 (p300‐TAD activity), an important transcriptional co‐activator of Sox9. Results of these studies demonstrate for the first time that PI3K/AKT signaling controls aggrecan gene expression, in part by modulating Sox9 expression and activity in cells of the nucleus pulposus. J. Cell. Physiol. 221: 668–676, 2009. © 2009 Wiley‐Liss, Inc.
Ceramide metabolism determines glioma cell resistance to chemotherapy
Authors: Dumitru Claudia Alexandra , Weller Michael , Gulbins Erich 
Published: August 2009

AbstractTumor cell resistance to chemotherapy constitutes a major problem in the treatment of malignant tumors. We here investigated the role of ceramide metabolism for the resistance of glioma cells to treatment with the chemotherapeutic drug, gemcitabine. Gemcitabine triggers a marked release of ceramide in drug‐sensitive cells, while glioma cells that are resistant to gemcitabine, fail to accumulate ceramide. While the release of ceramide is very similar in gemcitabine‐sensitive and resistant glioma cells upon stimulation, resistant glioma cells rapidly consume ceramide upon gemcitabine treatment or exogenous sphingomyelinase stimulation. Pharmacologic or genetic inhibition of glucosyltransferases prevents ceramide consumption in resistant cells and restores sensitivity of resistant glioma cells to gemcitabine. These data suggest that glioma cell resistance to at least some chemotherapeutic drugs is mediated by rapid consumption of ceramide to prevent cell death. J. Cell. Physiol. 221: 688–695, 2009. © 2009 Wiley‐Liss, Inc.
Divergent reactivity in tandem reduction–Michael ring closures of five‐ and six‐membered cyclic enones
Authors: Bunce Richard A. , Nammalwar Baskar , Slaughter LeGrande M. 
Published: August 2009

Abstract
magnified imageIn this study, methyl (±)‐1‐(2‐nitrobenzyl)‐4‐oxo‐2‐cyclohexene‐1‐carboxylate and methyl (±)‐(2‐nitrobenzyl)‐4‐oxo‐2‐cyclopentene‐1‐carboxylate were prepared and subjected to reductive cyclization under dissolving metal conditions. The two reactants showed divergent behavior with the six‐ring substrate reacting at the ester carbonyl and the five‐ring substrate closing on the enone double bond. The difference in reactivity is attributed to the conformational flexibility, relative reactivity, and steric environment of C4‐substituted six‐ and five‐membered cyclic enones. J. Heterocyclic Chem., (2009).
Anatomy of virgin and mature externae of Loxothylacus texanus, parasitic on the dark blue crab Callinectes rathbunae (Crustacea: Cirripedia: Rhizocephala: Sacculinidae)
Authors: Alvarez Fernando , Bortolini José Luis , Høeg Jens T. 
Published: August 2009

AbstractRhizocephalan parasites are dioecious organisms, in that one or several dwarf males are implanted into the external part of the female parasite soon after it emerges from the interior of the host animal. The structure of the female externa and its resident males is crucial for understanding both the reproductive biology and the taxonomy of these specialized parasites. We use scanning electron microscopy and histological methods to study the anatomy of juvenile and the mature externae of the rhizocephalan barnacle Loxothylacus texanus parasitizing the blue crab Callinectes rathbunae. We put emphasis on the implantation of males and the histology of the female reproductive organs. In the virgin externae, male cyprids attach around a cuticular hood covering the mantle aperture, which is partially blocked by a plug of cuticle so only trichogon larvae, not cyprids, can access the mantle cavity. This resembles the situation known from Sacculina carcini. The mature externa is characterized by a visceral mass that contains the ovary, paired colleteric glands, a single male receptacle, but paired receptacle ducts. The proximal attachment of the visceral mass is located at some distance from the basal stalk, as is characteristic for the genus Loxothylacus. The internal anatomy of the mature externa of L. texanus is in most features similar to that seen in other species of the Sacculinidae, which comprises the majority of rhizocephalan species. However, the single receptacle creates a situation where the two implanted males cannot be kept separate as in most other rhizocephalans, but pass through spermatogenesis in a common chamber. This may have unknown effects on the reproductive biology such as male–male competition. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.
Fast spin‐echo triple‐echo Dixon: Initial clinical experience with a novel pulse sequence for fat‐suppressed T2‐weighted abdominal MR imaging
Authors: Low Russell N. , Ma Jingfei , Panchal Neeraj 
Published: August 2009

AbstractPurposeTo evaluate a prototype fast spin echo (FSE) triple‐echo‐Dixon (fTED) technique for breath‐hold, fat‐suppressed, T2‐weighted abdominal imaging.Materials and MethodsForty patients underwent breath‐hold T2‐weighted abdominal imaging with fTED and conventional fast recovery (FR) FSE with chemical shift‐selective saturation (CHESS). FRFSE and fTED images were compared for overall image quality, homogeneity of fat suppression, image sharpness, anatomic detail, and phase artifact. Depiction of disease was recorded separately for FRFSE and fTED images.ResultsFTED successfully reconstructed water‐only and fat‐only images from source images in all 40 cases. Water and fat separation was perfect in 36 (0.90) patients. Homogeneity of fat suppression was superior on the fTED images in 38 (0.95) of 40 cases. FTED images showed better anatomic detail in 27 (0.68), and less susceptibility artifact in 20 (0.50). FRFSE images showed less vascular pulsation artifact in 30 (0.75) cases, and less phase artifact in 21 (0.53) cases. There was no difference in depiction of disease for FRFSE and fTED images.ConclusionFTED is a robust sequence providing breath‐hold T2‐weighted images with superior fat suppression, excellent image quality, and at least equal depiction of disease compared to conventional breath‐hold T2‐weighted FRFSE imaging. J. Magn. Reson. Imaging 2009;30:569–577. © 2009 Wiley‐Liss, Inc.
Diffusion‐weighted imaging of breast cancer: Correlation of the apparent diffusion coefficient value with prognostic factors
Authors: Kim Sung Hun , Cha Eun Suk , Kim Hyeon Sook , Kang Bong Joo , Choi Jae Jeong , Jung Ji Han , Park Yong Gyu , Suh Young Jin 
Published: August 2009

AbstractPurposeTo evaluate the role of diffusion‐weighted imaging (DWI) in the detection of breast cancers, and to correlate the apparent diffusion coefficient (ADC) value with prognostic factors.Materials and MethodsSixty‐seven women with invasive cancer underwent breast MRI. Histological specimens were analyzed for tumor size and grade, and expression of estrogen receptors (ER), progesterone receptors, c‐erbB‐2, p53, Ki‐67, and epidermal growth factor receptors. The computed mean ADC values of breast cancer and normal breast parenchyma were compared. Relationships between the ADC values and prognostic factors were determined using Wilcoxon signed rank test and Kruskal‐Wallis test.ResultsDWI detected breast cancer as a hyperintense area in 62 patients (92.5 %). A statistically significant difference in the mean ADC values of breast cancer (1.09 ± 0.27 × 10−5 mm2/s) and normal parenchyma (1.59 ± 0.27 × 10−5 mm2/s) was detected (P < 0.0001). There were no correlations between the ADC value and prognostic factors. However, the median ADC value was lower in the ER‐positive group than the ER negative group, and this difference was marginally significant (1.09 × 10−5 mm2/s versus 1.15 × 10−5 mm2/s, P = 0.053).ConclusionThe ADC value was a helpful parameter in detecting malignant breast tumors, but ADC value could not predict patient prognosis. J. Magn. Reson. Imaging 2009;30:615–620. © 2009 Wiley‐Liss, Inc.
Pre‐ and postoperative MR brain imaging with automatic planning and scanning software in tumor patients: An intraindividual comparative study at 3 Tesla
Authors: Nelles Michael , Gieseke Juergen , Urbach Horst , Semrau Renate , Bystrov Daniel , Schild Hans H. , Willinek Winfried A. 
Published: August 2009

AbstractPurposeTo evaluate the feasibility of automatic planning and scanning of brain MR imaging (MRI) protocols on a clinical 3 Tesla system in tumor patients before and after neurosurgical intervention.Materials and MethodsTwenty‐nine patients with intra‐axial lesions were examined with automated planscan software pre‐ and postoperatively. MR section geometries were determined using intensity‐based three‐dimensional registration and an extraction of landmarks. The technique involved an active shape model to match the boundaries of anatomical structures and typical shape variations. Insufficient geometries were corrected manually by a trained operator.ResultsIn 29/29 of the preoperative and 47/58 MRI sessions in total, no manual interaction was necessary. Predominantly minor corrections were necessary in 11/29 postoperative sessions, with critical corrections (≥ 3‐mm offcenter change or ≥ 5° in alignment of the stacks) in 3/58 sessions. Mean offcenter correction was 1.41 mm (range, 0–7.33 mm), mean angle change toward the midline or commissural line was 1.43° (range, 0–8.05°).ConclusionAutomatic planning and scanning before and after brain surgery yields robust results in most of the patients with substantial shape deviations. The dimensions of necessary geometry corrections are predominantly small. These results are promising to minimize interscan variability in longitudinal studies. J. Magn. Reson. Imaging 2009;30:672–677. © 2009 Wiley‐Liss, Inc.
An analysis of cloud observations from Vernadsky, Antarctica
Authors: Kirchgäßner Amélie 
Published: August 2009

AbstractThis paper presents results of a combined analysis of cloud observations made at the Antarctic base Faraday/Vernadsky between 1960 and 2005 and sea ice concentration from the HadISST1 data set.The annual total cloud cover has increased significantly during this period with the strongest and most significant positive trend found in winter, and positive tendencies observable in all seasons. This trend is associated with a decrease in sea ice concentration in the area of the Western Antarctic Peninsula. Though the observed sea ice reduction is actually larger and more significant in summer and autumn, there is actually a significant relation between total cloud cover and sea ice concentration only in winter.The increase in the total cloud cover is neither reflected in the low cloud amount nor in the number of records for low, medium or high level clouds. It is therefore thought that the increase in the total cloud cover is caused by an increase in the amount of medium and/or high level clouds. Instead, records for the low cloud amount show a redistribution from cases of extreme cloud cover (0, 1, 7 and 8 okta), which account for up to 90% of annual records, to cases of moderate cloud cover. In accordance with the decrease in sea ice, this may indicate a shift from low‐level stratiform towards convective clouds. Copyright © 2009 Royal Meteorological Society
Intercomparing multiple measures of the onset of spring in eastern North America
Authors: Schwartz Mark D. , Hanes Jonathan M. 
Published: August 2009

AbstractMeasuring the onset of deciduous tree leaf flush and subsequent development during the spring season in temperate climates can be accomplished using multiple ground and satellite‐based techniques. Although all these measurements are valid (i.e. record a real characteristic related to plant development), they typically are poorly inter‐related due to incompatible levels of spatial representation and differing methodologies. Given recent and likely future impacts of climate change on spring leaf development, the need to reconstruct past patterns, and the lack of standardised vegetation change measurements around the world, more work is needed to determine the relationships among the various measures, and the degree to which they may serve as substitutes for each other. In this article, we use observations and measurements at two phenology ‘super‐sites’ in eastern North America and four other supporting sites to evaluate the relationships among multiple spring leaf development measures, and explore strategies to standardise their intercomparison. The results show infrequent significant correlations among 10 satellite‐derived ‘start of season’ (SOS) measures (which suggests they are often not detecting the same phenomena), along with more common significant correlations among six ground phenology measures. However, when ground phenology and satellite‐derived SOS are compared, there are few significant correlations, even at sites with extensive native species phenology available. Modelled phenology, based on daily temperature data (Spring Indices First Bloom date) does as well as any of the direct native species measures, and is well suited to facilitate intercomparisons. In order to effectively compare ground‐based and satellite‐derived SOS measures, approaches that use limited numbers of individual plants face considerable challenges. Given that satellite‐derived measures are areal and at a scale of 250 m and larger, we suggest collecting ground phenology data at the same areal scale in order to make effective comparisons. Copyright © 2009 Royal Meteorological Society
Effects of platelet‐rich plasma on the quality of repair of mechanically induced core lesions in equine superficial digital flexor tendons: A placebo‐controlled experimental study
Authors: Bosch Gerco , van Schie Hans T. M. , de Groot Mark W. , Cadby Jennifer A. , van de Lest Chris H. A. , Barneveld Ab , van Weeren P. René 
Published: August 2009

AbstractTendon injuries are notorious for their slow and functionally inferior healing. Intratendinous application of platelet‐rich plasma (PRP) has been reported to stimulate the repair process of tendon injuries, but there is little conclusive evidence for its effectiveness. A placebo‐controlled experimental trial was performed to test the hypothesis that a single intratendinous PRP treatment enhances the quality of tendon repair, as evidenced by improved biochemical, biomechanical, and histological tissue properties. In six horses, tendon lesions were created surgically in the Superficial Digital Flexor Tendons (SDFT) of both front limbs, one of which was treated with PRP and the other with saline. After 24 weeks, the tendons were harvested for biochemical, biomechanical, and histological evaluations. Collagen, glycosaminoglycan, and DNA content (cellularity) was higher in PRP‐treated tendons (p = 0.039, 0.038, and 0.034, respectively). The repair tissue in the PRP group showed a higher strength at failure (p = 0.021) and Elastic Modulus (p = 0.019). Histologically, PRP‐treated tendons featured better organization of the collagen network (p = 0.031) and signs of increased metabolic activity (p = 0.031). It was concluded that PRP increases metabolic activity and seems to advance maturation of repair tissue over nontreated experimentally induced tendon lesions, which suggests that PRP might be beneficial in the treatment of clinical tendon injuries. © 2009 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:211–217, 2010
Revolving hollow fiber–liquid phase microextraction coupled to GC/MS using electron ionization for quantification of five aromatic hydrocarbon isomers
Authors: Chen Yuan‐Chin , Wu Hui‐Fen 
Published: August 2009

AbstractA dynamic liquid phase microextraction method using a revolving hollow fiber was demonstrated for coupling to GC/MS [using EI (electronic ionization) and selected ion monitor (SIM)] as a concentrating probe for rapid analysis and quantitative determination of five aromatic hydrocarbon isomers (cumene; propylbenzene; 2‐ethyltoluene; 1,2,3‐trimethylbenzene; and 1,2,4‐trimethylbenzene) from biological matrices (human urine and human plasma). This technique was named as revolving hollow fiber–liquid phase microextraction (RHF–LPME). The optimized parameters of RHF–LPME coupled to GC/MS experiments were extraction solvent, toluene; extraction time, 2 min; sample agitation rate, 700 rpm; salt concentration, 0%; rotating speed for motor driving rotator, 250 rpm; and the rotator was operated in a reversed direction with the stirrer. The linear range of calibration curve of RHF–LPME was from 0.002 to 0.4 μg/mL with R2 > 0.9916 and the RSD values were from 4.5 to 5.2%. Additionally, comparing to single drop microextraction (SDME), this method offers better limits of detection (LODs) and EF (enrichment factor). This approach exhibits many advantages including simplicity, rapid detection with high reproducibility and high extraction efficiency, easy to operate and fast to reach equilibrium for analyzing biological samples. This approach has the potential to be widely used because it only requires simple devices to perform all extraction processes. We believe that this technique can be a powerful tool for GC/MS analysis of biological samples and clinical applications in the near future.