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111.
Merabet LB Swisher JD McMains SA Halko MA Amedi A Pascual-Leone A Somers DC 《Journal of neurophysiology》2007,97(2):1633-1641
The involvement of occipital cortex in sensory processing is not restricted solely to the visual modality. Tactile processing has been shown to modulate higher-order visual and multisensory integration areas in sighted as well as visually deprived subjects; however, the extent of involvement of early visual cortical areas remains unclear. To investigate this issue, we employed functional magnetic resonance imaging in normally sighted, briefly blindfolded subjects with well-defined visuotopic borders as they tactually explored and rated raised-dot patterns. Tactile task performance resulted in significant activation in primary visual cortex (V1) and deactivation of extrastriate cortical regions V2, V3, V3A, and hV4 with greater deactivation in dorsal subregions and higher visual areas. These results suggest that tactile processing affects occipital cortex via two distinct pathways: a suppressive top-down pathway descending through the visual cortical hierarchy and an excitatory pathway arising from outside the visual cortical hierarchy that drives area V1 directly. 相似文献
112.
Cappelletti M Barth H Fregni F Spelke ES Pascual-Leone A 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2007,179(4):631-642
It has been widely argued that the intraparietal sulcus (IPS) is involved in tasks that evoke representations of numerical
magnitude, among other cognitive functions. However, the causal role of this parietal region in processing symbolic and non-symbolic
numerosity has not been established. The current study used repetitive Transcranial Magnetic Stimulation (rTMS) to the left
and right IPS to investigate the effects of temporary deactivations of these regions on the capacity to represent symbolic
(Arabic numbers) and non-symbolic (arrays of dots) numerosities. We found that comparisons of both symbolic and non-symbolic
numerosities were impaired after rTMS to the left IPS but enhanced by rTMS to the right IPS. A signature effect of numerical
distance was also found: greater impairment (or lesser facilitation) when comparing numerosities of similar magnitude. The
reverse pattern of impairment and enhancement was found in a control task that required judging an analogue stimulus property
(ellipse orientation) but no numerosity judgements. No rTMS effects for the numerosity tasks were found when stimulating an
area adjacent but distinct from the IPS, the left and right angular gyrus. These data suggest that left IPS is critical for
processing symbolic and non-symbolic numerosity; this processing may thus depend on common neural mechanisms, which are distinct
from mechanisms supporting the processing of analogue stimulus properties.
H. Barth and F. Fregni contributed equally to this study. 相似文献
113.
Derek K. Ng Anthony A. Portale Susan L. Furth Bradley A. Warady Alvaro Muñoz 《Annals of epidemiology》2018,28(8):549-556
Purpose
Coefficients of determination (R2) for continuous longitudinal data are typically reported as time constant, if they are reported at all. The widely used mixed model with random intercepts and slopes yields the total outcome variance as a time-varying function. We propose a generalized and intuitive approach based on this variance function to estimate the time-varying predictive power (R2) of a variable on outcome levels and changes.Methods
Using longitudinal estimated glomerular filtration rate (eGFR) from the Chronic Kidney Disease in Children Study, linear mixed models characterized the R2 for two chronic kidney disease (CKD) risk factors measured at baseline: a traditional marker (proteinuria) and a novel marker (fibroblast growth factor 23 [FGF23]).Results
Time-varying R2 divulged different disease processes by risk factor and diagnoses. Among children with glomerular CKD, time-varying R2 for proteinuria had significant upward trends, suggesting increasing power to predict eGFR change, but crossed with FGF23, which was higher up to 2.5 years from baseline. In contrast, among those with nonglomerular CKD, proteinuria explained more than FGF23 at all times, and time-varying R2 for each risk factor was not substantially different from time-constant estimates.Conclusions
Proteinuria and FGF23 explained substantial eGFR variability over time. Time-varying R2 can characterize predictive roles of risk factors on disease progression, overcome limitations of time-constant estimates, and are easily derived from mixed effects models. 相似文献114.
115.
First characterization of fluoroquinolone resistance in Streptococcus suis 总被引:5,自引:0,他引:5
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Escudero JA San Millan A Catalan A de la Campa AG Rivero E Lopez G Dominguez L Moreno MA Gonzalez-Zorn B 《Antimicrobial agents and chemotherapy》2007,51(2):777-782
We have identified and sequenced the genes encoding the quinolone-resistance determining region (QRDR) of ParC and GyrA in fluoroquinolone-susceptible and -resistant Streptococcus suis clinical isolates. Resistance is the consequence of single point mutations in the QRDRs of ParC and GyrA and is not due to clonal spread of resistant strains or horizontal gene transfer with other bacteria. 相似文献
116.
117.
In Vitro Activities of Ketolide HMR 3647, Macrolides, and Clindamycin against Coryneform Bacteria 总被引:3,自引:2,他引:3
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Luis Martínez-Martínez Alvaro Pascual Ana Isabel Surez Evelio J. Perea 《Antimicrobial agents and chemotherapy》1998,42(12):3290-3292
The in vitro activity of ketolide HMR 3647 against coryneform bacteria isolated from clinical samples was evaluated. Except against Corynebacterium jeikeium and C. urealyticum, HMR 3647 showed high activity against Corynebacterium spp., being more active than 14- and 16-membered macrolides, azithromycin, or clindamycin. HMR 3647 also had high in vitro activity against Brevibacterium spp. and Listeria monocytogenes. 相似文献
118.
A Cantafora A Di Biase D Alvaro M Angelico M Marin A F Attili 《Clinica chimica acta; international journal of clinical chemistry》1983,134(3):281-295
In this paper we propose a novel, rapid and simple high-performance liquid chromatographic (HPLC) method for the identification and quantitation of individual phosphatidylcholine (PC) molecular species from natural mixtures. To overcome difficulties deriving from the lack of adequate standards and from the variability of the responses to UV spectrophotometric detectors currently used in HPLC analysis, we first fractionated and quantitated the major molecular species of a commercial egg PC by means of a preparative column. The identification of PC molecular species was confirmed by gas-liquid chromatographic analysis of fatty acids. We employed the fractions recovered from preparative HPLC to determine the detector calibration factors of the individual molecular species separated using an analytical, high-speed, reversed-phase HPLC column. The proposed method seems to be adequate for the analysis of PC from many biological sources. Its application to the analysis of human hepatic and gallbladder biliary PC is shown. 相似文献
119.
Ohad Ronen K. Thomas Robbins Kerry D. Olsen Ashok R. Shaha Gregory W. Randolph Iain J. Nixon Mark E. Zafereo Dana M. Hartl Luiz P. Kowalski Juan P. Rodrigo Andrs Coca‐Pelaz Antti A. Mkitie Vincent Vander Poorten Alvaro Sanabria Peter Angelos Alessandra Rinaldo Alfio Ferlito 《Head & neck》2020,42(10):3061-3071
Recent modifications in the management of well‐differentiated thyroid cancer have resulted in significant alterations in clinical approach. Utilizing a series of preoperative and postoperative risk factors involving both the patient and the disease pathology, we offer the term “staged thyroidectomy” to help organize these risk factors for patients and the endocrine team to optimize management. This approach is intended to incorporate our latest nuanced understanding of certain endocrine pathology and may serve to optimize patient outcomes. 相似文献
120.