200 research outputs found

    Diagnostic algorithm for papillary urothelial tumors in the urinary bladder

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    Papillary urothelial neoplasms with deceptively bland cytology cannot be easily classified. We aimed to design a new algorithm that could differentiate between these neoplasms based on a scoring system. We proposed a new scoring system that enables to reproducibly diagnose non-invasive papillary urothelial tumors. In this system, each lesion was given individual scores from 0 to 3 for mitosis and cellular thickness, from 0 to 2 for cellular atypia, and an additional score for papillary fusion. These scores were combined to form a summed score allowing the tumors to be ranked as follows: 0–1 = UP, 2–4 = low malignant potential (LMP), 5–7 = low-grade transitional cell carcinoma (TCC), and 8–9 = high-grade TCC. In addition to the scoring system, ancillary studies of MIB and p53 indexes with CK20 expression pattern analyses were compared together with clinical parameters. The MIB index was strongly correlated with disease progression. Four of the 22 LMP patients (18.2%) had late recurrences, two of these four (9.1%) had progression to low-grade carcinoma. The MIB index for LMP patients was strongly associated with recurrence (recurrence vs. non-recurrence, 16.5 vs. 8.1, p < 0.001). The proposed scoring system could enhance the reproducibility to distinguish papillary urothelial neoplasms

    Mislocalization of Visual Stimuli: Independent Effects of Static and Dynamic Attention

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    Shifts of visual attention cause systematic distortions of the perceived locations of visual objects around the focus of attention. In the attention repulsion effect, the perceived location of a visual target is shifted away from an attention-attracting cue when the cue is presented before the target. Recently it has been found that, if the visual cue is presented after the target, the perceived location of the target shifts toward the location of the following cue. One unanswered question is whether a single mechanism underlies both attentional repulsion and attraction effects. We presented participants with two disks at diagonal locations as visual cues and two vertical lines as targets. Participants were asked to perform a forced-choice task to judge targets' positions. The present study examined whether the magnitude of the repulsion effect and the attraction effect would differ (Experiment 1), whether the two effects would interact (Experiment 2), and whether the location or the dynamic shift of attentional focus would determine the distortions effects (Experiment 3). The results showed that the effect size of the attraction effect was slightly larger than the repulsion effect and the preceding and following cues have independent influences on the perceived positions. The repulsion effect was caused by the location of attnetion and the attraction effect was due to the dynamic shift of attentional focus, suggesting that the underlying mechanisms for the retrospective attraction effect might be different from those for the repulsion effect

    Visual Learning in Multiple-Object Tracking

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    Tracking moving objects in space is important for the maintenance of spatiotemporal continuity in everyday visual tasks. In the laboratory, this ability is tested using the Multiple Object Tracking (MOT) task, where participants track a subset of moving objects with attention over an extended period of time. The ability to track multiple objects with attention is severely limited. Recent research has shown that this ability may improve with extensive practice (e.g., from action videogame playing). However, whether tracking also improves in a short training session with repeated trajectories has rarely been investigated. In this study we examine the role of visual learning in multiple-object tracking and characterize how varieties of attention interact with visual learning.Participants first conducted attentive tracking on trials with repeated motion trajectories for a short session. In a transfer phase we used the same motion trajectories but changed the role of tracking targets and nontargets. We found that compared with novel trials, tracking was enhanced only when the target subset was the same as that used during training. Learning did not transfer when the previously trained targets and nontargets switched roles or mixed up. However, learning was not specific to the trained temporal order as it transferred to trials where the motion was played backwards.These findings suggest that a demanding task of tracking multiple objects can benefit from learning of repeated motion trajectories. Such learning potentially facilitates tracking in natural vision, although learning is largely confined to the trajectories of attended objects. Furthermore, we showed that learning in attentive tracking relies on relational coding of all target trajectories. Surprisingly, learning was not specific to the trained temporal context, probably because observers have learned motion paths of each trajectory independently of the exact temporal order

    Expression of RECK and matrix metalloproteinase-2 in ameloblastoma

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    <p>Abstract</p> <p>Background</p> <p>Ameloblastoma is a frequent odontogenic benign tumor characterized by local invasiveness, high risk of recurrence and occasional metastasis and malignant transformation. Matrix metalloproteinase-2 (MMP-2) promotes tumor invasion and progression by destroying the extracellular matrix (ECM) and basement membrane. For this proteolytic activity, the endogenous inhibitor is reversion-inducing cysteine rich protein with Kazal motifs (RECK). The aim of this study was to characterize the relationship between RECK and MMP-2 expression and the clinical manifestation of ameloblastoma.</p> <p>Methods</p> <p>Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were employed to detect the protein and mRNA expression of RECK and MMP-2 in keratocystic odontogenic tumor (KCOT), ameloblastoma and ameloblastic carcinoma.</p> <p>Results</p> <p>RECK protein expression was significantly reduced in KCOT (87.5%), ameloblastoma (56.5%) and ameloblastic carcinoma (0%) (P < 0.01), and was significantly lower in recurrent ameloblastoma compared with primary ameloblastoma (P < 0.01), but did not differ by histological type of ameloblastoma. MMP-2 protein expression was significantly higher in ameloblastoma and ameloblastic carcinoma compared with KCOT (P < 0.01). RECK mRNA expression was significantly lower in ameloblastoma than in KCOT (P < 0.01), lower in recurrent ameloblastoma than in primary ameloblastoma, and was negative in ameloblastic carcinoma. MMP-2 mRNA expression was significantly higher in ameloblastoma compared with KCOT (P < 0.01), but was no different in recurrent ameloblastoma versus primary ameloblastoma. RECK protein expression was negatively associated with MMP-2 protein expression in ameloblastoma (r = -0.431, P < 0.01).</p> <p>Conclusion</p> <p>Low or no RECK expression and increased MMP-2 expression may be associated with negative clinical findings in ameloblastoma. RECK may participate in the invasion, recurrence and malignant transformation of ameloblastoma by regulating MMP-2 at the post-transcriptional level.</p

    Experimental and numerical investigations on the seismic behavior of bridge piers with vertical unbonded prestressing strands

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    In the performance-based seismic bridge design, piers are expected to undergo large inelastic deformations during severe earthquakes, which in turn can result in large residual drift and concrete crack in the bridge piers. In this paper, longitudinal unbonded prestressing strands are used to minimize residual drift and residual concrete crack width in reinforced concrete (RC) bridge piers. Seven pier specimens were designed and tested quasi-statically and the numerical simulations were carried out. The effectiveness of using vertical unbonded prestressing strands to mitigate the residual drift and concrete crack width of RC bridge piers are examined and discussed in detail. It is found that the residual drift and residual concrete crack width of the piers can be reduced significantly by using the prestressing strands. Moreover, the strands can increase the lateral strength of the piers while have little influence on the ductility capacity of the piers. The hysteretic curves, residual drifts and strand stress of the piers predicted by the numerical model agree well with the testing data and can be used to assess the cyclic behavior of the piers

    Bottom-up assembly of metallic germanium

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    Extending chip performance beyond current limits of miniaturisation requires new materials and functionalities that integrate well with the silicon platform. Germanium fits these requirements and has been proposed as a high-mobility channel material, a light emitting medium in silicon-integrated lasers, and a plasmonic conductor for bio-sensing. Common to these diverse applications is the need for homogeneous, high electron densities in three-dimensions (3D). Here we use a bottom-up approach to demonstrate the 3D assembly of atomically sharp doping profiles in germanium by a repeated stacking of two-dimensional (2D) high-density phosphorus layers. This produces high-density (1019 to 1020 cm-3) low-resistivity (10-4Ω ∙ cm) metallic germanium of precisely defined thickness, beyond the capabilities of diffusion-based doping technologies. We demonstrate that free electrons from distinct 2D dopant layers coalesce into a homogeneous 3D conductor using anisotropic quantum interference measurements, atom probe tomography, and density functional theory

    Solitary osteochondroma of the twelfth rib with intraspinal extension and cord compression in a middle-aged patient

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    <p>Abstract</p> <p>Background</p> <p>Osteochondroma is a disease of growing bone and thus typically presents in younger patients. It has rarely been described in middle-aged and elderly patients. Data on the occurrence of osteochondroma show that the reported incidence of costal osteochondroma is very low. Moreover, costal osteochondroma arising at the costovertebral junction with neural foraminal extension and spinal cord compression is extremely rare.</p> <p>Case presentation</p> <p>This study reports the case of a 58-year-old patient with a solitary osteochondroma of the 12th rib with intraspinal extension and spinal cord compression. The clinical history, plain radiographs, computed tomography (CT), magnetic resonance imaging, and pathologic findings of the reported patient have been reviewed. The relevant medical literature has also been reviewed. The patient was treated with surgery for complete tumour excision to avoid tumour recurrence. After surgery, the patient's symptoms improved. An additional CT scan obtained at 1 year after surgery did not show any evidence of recurrence.</p> <p>Conclusions</p> <p>This patient is the oldest patient reported to have this rare form of costal osteochondroma. The age of the patient and the erosion of the adjacent bones raised clinical suspicion of malignancy; therefore, surgical management involved complete tumour excision with thoracolumbar fixation and fusion.</p

    Pine cone scale-inspired motile origami

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    Stimuli-sensitive hydrogels have received attention because of their potential applications in various fields. Stimuli-directed motion offers many practical applications, such as in drug delivery systems and actuators. Directed motion of asymmetric hydrogels has long been designed; however, few studies have investigated the motion control of symmetric hydrogels. We designed a pine cone scale-inspired movable temperature-sensitive symmetric hydrogel that contains Fe3O4. Alignment of Fe3O4 along the magnetic force is key in motion control in which Fe3O4 acts like fibers in a pine cone scale. Although a homogeneous temperature-sensitive hydrogel cannot respond to a temperature gradient, the Fe3O4-containing hydrogel demonstrates considerable bending motion. Varying degrees and directions of motion are easily facilitated by controlling the amount and alignment angle of the Fe3O4. The shape of the hydrogel layer also influences the morphological structure. This study introduced facile and low-cost methods to control various bending motions. These results can be applied to many fields of engineering, including industrial engineering.111Ysciescopu

    EEG Correlates of Attentional Load during Multiple Object Tracking

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    While human subjects tracked a subset of ten identical, randomly-moving objects, event-related potentials (ERPs) were evoked at parieto-occipital sites by task-irrelevant flashes that were superimposed on either tracked (Target) or non-tracked (Distractor) objects. With ERPs as markers of attention, we investigated how allocation of attention varied with tracking load, that is, with the number of objects that were tracked. Flashes on Target discs elicited stronger ERPs than did flashes on Distractor discs; ERP amplitude (0–250 ms) decreased monotonically as load increased from two to three to four (of ten) discs. Amplitude decreased more rapidly for Target discs than Distractor discs. As a result, with increasing tracking loads, the difference between ERPs to Targets and Distractors diminished. This change in ERP amplitudes with load accords well with behavioral performance, suggesting that successful tracking depends upon the relationship between the neural signals associated with attended and non-attended objects
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