Phys Rev E Stat Nonlin Soft Matter Phys
March 2011
The curved channel appears to be indispensable for the lab-on-chips systems because it provides a convenient scheme for increasing the channel length per unit chip area in the direction of net flow. A secondary Dean flow in curved rectangular microchannels is examined by applying the finite-volume scheme with a semi-implicit method for pressure-linked equations (SIMPLE) algorithm for the pressure-driven electrokinetic transport. This framework is based on the theoretical model coupled with the full Poisson-Boltzmann, Navier-Stokes, and the Nernst-Planck principles of net charge conservation [Yun et al.
View Article and Find Full Text PDFAim: The QuantiGene2.0 assay has low interlaboratory variability and can directly measure RNA levels without a reverse transcription step or a polymerase chain reaction process. To evaluate the utility of the QuantiGene2.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
April 2011
Remembering an event from the past is often complicated by the fact that our memories are cluttered with similar events. Though competition is a fundamental part of remembering, there is little evidence of how mnemonic competition is neurally represented. Here, we assessed whether competition between visual memories is captured in the relative degree to which target vs.
View Article and Find Full Text PDFBackground And Purpose: Since the introduction of CT-based simulation for use in whole brain radiotherapy (WBRT), we have observed that a large volume of the parotid glands is included in the radiation fields. The purpose of this study is to analyze the dose-volume statistics of the parotid glands in patients undergoing WBRT.
Materials And Methods: Thirty-two patients received WBRT using CT-based simulation with bilateral two-field arrangement.
Visual working memory and visual attention are intimately related, such that working memory encoding and maintenance reflects actively sustained attention to a limited number of visual objects and events important for ongoing cognition and action. Although attention is typically considered to operate over perceptual input, a recent taxonomy proposes to additionally consider how attention can be directed to internal perceptual representations in the absence of sensory input, as well as other internal memories, choices, and thoughts (Chun, Golomb, & Turk-Browne, 2011). Such internal attention enables prolonged binding of features into integrated objects, along with enhancement of relevant sensory mechanisms.
View Article and Find Full Text PDFTo explore visual scenes in the everyday world, we constantly move our eyes, yet most neural studies of scene processing are conducted with the eyes held fixated. Such prior work in humans suggests that the parahippocampal place area (PPA) represents scenes in a highly specific manner that can differentiate between different but overlapping views of a panoramic scene. Using functional magnetic resonance imaging (fMRI) adaptation to measure sensitivity to change, we asked how this specificity is affected when active eye movements across a stable scene generate retinotopically different views.
View Article and Find Full Text PDFOffering reward for performance can motivate people to perform a task better, but better preparation for one task usually means decreased flexibility to perform different tasks. In six experiments in which reward varied between low and high levels, we found that reward can encourage people to prepare more flexibly for different tasks, but only as it increased from the level on the previous trial. When the same high rewards were offered continuously trial after trial, people were more inclined to simply stick with doing what had worked previously.
View Article and Find Full Text PDFThe gas discharge and photo-luminance properties of a planar lighting source featuring highly uniform light emission and mercury-free design were studied. The current density-voltage characteristics and the associated gas discharge of the devices operating with the values of the ratio of electric field to gas pressure (E/p) between 4.3 kV/Torr-cm and 35.
View Article and Find Full Text PDFDuring natural vision, eye movements can drastically alter the retinotopic (eye-centered) coordinates of locations and objects, yet the spatiotopic (world-centered) percept remains stable. Maintaining visuospatial attention in spatiotopic coordinates requires updating of attentional representations following each eye movement. However, this updating is not instantaneous; attentional facilitation temporarily lingers at the previous retinotopic location after a saccade, a phenomenon known as the retinotopic attentional trace.
View Article and Find Full Text PDFThe need for physicians formally trained to deliver care to diverse patient populations has been widely advocated. Utilizing a validated tool, Weissman and Betancourt's Cross-Cultural Care Survey, the aim of this current study was to compare surgery and family medicine residents' perceptions of their preparedness and skillfulness to provide high quality cross-cultural care. Past research has documented differences between the two groups' reported impressions of importance and level of instruction received in cross-cultural care.
View Article and Find Full Text PDFExcessive calcium is thought to be a critical step in various neurodegenerative processes including ischemia. Calbindin D28k (CB), calretinin (CR), and parvalbumin (PV), members of the EF-hand calcium-binding protein family, are thought to play a neuroprotective role in various pathologic conditions by serving as a buffer against excessive calcium. The expression of CB, PV and CR in the ischemic rat retina induced by increasing intraocular pressure was investigated at the transcript and protein levels, by means of the quantitative real-time reverse transcription-polymerase chain reaction, western blot and immunohistochemistry.
View Article and Find Full Text PDFα-Gustducin (Gα-gust) is the α subunit of the heterotrimeric G-protein complex specific for taste receptor cells of the tongue. However, it has been shown to be present in ectopic regions, such as airways and digestive tract. Recently, Gα-gust was found within neurons in various regions of the mouse brain.
View Article and Find Full Text PDFAim: The aim of this study was to assess various treatment options in stage IB2 cervical cancer patients.
Methods: Between January 1995 and May 2007, 63 patients with stage IB2 were treated by radical hysterectomy (n = 28), primary concurrent chemoradiation (CCRT, n = 16) or radiation therapy (RT, n = 19). Disease-free survival (DFS) and overall survival (OS) were compared between these treatment modalities.
Purpose: To determine the prevalence and factors predictive of spasticity in stroke patients transferred to a Department of Rehabilitation Medicine and to assess spasticity effects on motor recovery and functional outcomes.
Methods: A total of 245 patients consecutively admitted to the Department of Rehabilitation Medicine were evaluated. We examined spasticity prevalence and factors predictive of the condition.
Vascular endothelial growth factor receptor (VEGFR)-3, a receptor for VEGF-C and VEGF-D, has recently been suggested to play an important role during neuronal development. To characterize its potential role in CNS ontogenesis, we investigated the spatiotemporal and cellular expression of VEGFR-3 in developing and mature rat cerebellum using in situ hybridization. VEGFR-3 expression appeared as early as E15, and was restricted to the ventricular zone of the cerebellar primordium, the germinative neuroepithelium, but was absent by E20.
View Article and Find Full Text PDFVisual objects are high-level primitives that are fundamental to numerous perceptual functions, such as guidance of attention. We report that objects warp visual perception of space in such a way that spatial distances within objects appear to be larger than spatial distances in ground regions. When two dots were placed inside a rectangular object, they appeared farther apart from one another than two dots with identical spacing outside of the object.
View Article and Find Full Text PDFWe used the RIP1-Tag2 (RT2) mouse model of islet cell carcinogenesis to profile the transcriptome of pancreatic neuroendocrine tumors (PNET) that were either non-invasive or highly invasive, seeking to identify pro- and anti-invasive molecules. Expression of multiple components of desmosomes, structures that help maintain cellular adhesion, was significantly reduced in invasive carcinomas. Genetic deletion of one of these desmosomal components, desmoplakin, resulted in increased local tumor invasion without affecting tumor growth parameters in RT2 PNETs.
View Article and Find Full Text PDFCancer is a disease subject to both genetic and environmental influences. In this study, we used the RIP1-Tag2 (RT2) mouse model of islet cell carcinogenesis to identify a genetic locus that influences tumor progression to an invasive growth state. RT2 mice inbred into the C57BL/6 (B6) background develop both noninvasive pancreatic neuroendocrine tumors (PNET) and invasive carcinomas with varying degrees of aggressiveness.
View Article and Find Full Text PDFPurpose: The purpose of this present study was to develop and evaluate the psychometric properties of a needs scale for patients with cancer undergoing follow-up care (NS-C).
Methods: A preliminary NS-C of 48 was derived from literature reviews and in-depth interviews with patients with cancer. Content validation of the items was established by oncology physicians and nurses.
We administered both the rapid antigen test and real-time reverse transcriptase polymerase chain reaction (RT-PCR) test to 2154 patients in order to assess the diagnostic value of the rapid antigen test during Korean pandemics of H1N1 2009. The overall sensitivity was 70.0%, specificity was 97.
View Article and Find Full Text PDFOur environments are highly regular in terms of when and where objects appear relative to each other. Statistical learning allows us to extract and represent these regularities, but how this knowledge is used by the brain during ongoing perception is unclear. We used rapid event-related fMRI to measure hemodynamic responses to individual visual images in a continuous stream that contained sequential contingencies.
View Article and Find Full Text PDFTo identify whether vascular endothelial growth factor receptor (VEGFR)-3, a receptor for VEGF-C and VEGF-D, is involved in pathophysiology of stroke, we investigated the spatiotemporal regulation of VEGFR-3 mRNA after transient focal cerebral ischemia. Most of the increase in VEGFR-3 expression in the ischemic core could be attributed to brain macrophages, whereas VEGFR-3 in the peri-infarct penumbra region was predominantly expressed in reactive astrocytes. A subpopulation of VEGFR-3-expressing brain macrophages was positive for NG2 proteoglycan and showed proliferative activity.
View Article and Find Full Text PDFWith each eye movement, the image of the world received by the visual system changes dramatically. To maintain stable spatiotopic (world-centered) visual representations, the retinotopic (eye-centered) coordinates of visual stimuli are continually remapped, even before the eye movement is completed. Recent psychophysical work has suggested that updating of attended locations occurs as well, although on a slower timescale, such that sustained attention lingers in retinotopic coordinates for several hundred milliseconds after each saccade.
View Article and Find Full Text PDFOBJECTIVES In an effort to provide preventive advice, this paper aims to acknowledge what has not worked with regard to cultural competency initiatives. A successful cultural competency training initiative should have lasting impact on its participants in terms of long-term, ideally permanent changes to attitudes, knowledge and skills resulting in the provision of optimum care, regardless of a patient's cultural background. Legal mandates mean there is an assumed need for cultural competency curricula and training programmes for medical students and postgraduate medical trainees.
View Article and Find Full Text PDFThe heterodimeric sweet taste receptors, T1R2 and T1R3, have recently been proposed to be associated with the brain glucose sensor. To identify whether sweet taste signaling is regulated in response to an ischemic injury inducing acute impairment of glucose metabolism, we investigated the spatiotemporal expression of the sweet taste receptors and their associated taste-specific G-protein α-gustducin in the rat hippocampus after ischemia. The expression profiles of both receptor subunits and α-gustducin shared overlapping expression patterns in sham-operated and ischemic hippocampi.
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