The formation of complexes between soluble potato starch and three commercial alkyl polyglycosides has been studied by means of surface tension measurements at 37
°C. All surfactants assayed form ...complexes with starch, the quantity of bound surfactant being proportional to the amount of starch present in the solution. For all alkyl polyglycoside–starch systems tested, there is a direct proportional relationship between the bound and total surfactant concentrations, so that the formation of the surfactant–starch complex continues until the minimum surface tension is reached without detectable starch saturation prior to the occurrence of surfactant micelles. Binding isotherms and Scatchard plots support the idea that alkyl polyglycosides are bound to amylose by positive cooperative binding and to amylopectin by non-cooperative Langmuir-type binding.
In this paper, the estimation of the parameters of the Two-Wave with Diffuse Power (TWDP) fading distribution from the observation of the received signal envelope is addressed. Specifically, a ...moment-based approach for the estimation of the parameters and Δ for this fading model is introduced. We first set the boundaries of the estimation problem by calculating the Cramer-Rao lower Bound (CRB). Then, closed-from expressions that relate the moments of the received signal envelope to the parameters and Δ are used for the estimation. Monte-Carlo simulations show that the estimation error is close to the CRB for a wide range of values of the parameters and Δ.
Abstract only Renin is a key enzyme/hormone that controls blood pressure and fluid-electrolyte homeostasis. Renin transcription is subject to complex developmental, physiological, and pathological ...regulation. We have identified the cAMP pathway and associated epigenetic marks as crucial regulators of renin expression. However, those studies involved the use of cAMP activators or analogues or histone deacetylase inhibitors that alter the transcriptome and epigenome of the whole cell without exclusively targeting the renin locus. The CRISPR/Cas9 Type II bacterial immune system has been modified for genome editing in eukaryotes. This system consists of a CRISPR-associated endonuclease (Cas9) and single guide RNA (sgRNA) to target specific genomic areas. Modifications to the Cas9 enzyme have allowed the use of CRISPR to regulate gene expression by targeted modification of epigenetic marks. In this study we tested whether renin expression can be induced by a nuclease-null dCas9 protein fused to the catalytic core of the acetyltransferase p300 (dCas9p300) and sgRNAs directed to the renin promoter and enhancer. We used cultured arteriolar smooth muscle cells of the renin lineage that constitutively express CFP (a renin lineage marker) and YFP only when the renin gene is turned on. Cells were transfected with a dCas9p300 and sgRNA expression vectors and analyzed for YFP expression 48h after transfection. We tested four sgRNAs targeting the renin enhancer and five sgRNAs targeting the renin promoter either individually or in combination. We found few YFP+ cells when all 4 enhancer sgRNAs or 5 promoter sgRNAs were simultaneously used. The highest YFP expression (32±9 cells/well) was observed when two enhancer sgRNAs (at positions -2,757 and -2,631) and three promoter sgRNAs (at positions -719, -50 and -25) were simultaneously added to the cells. We did not find any YFP+ cells when the dCas9p300 plasmid was transfected without sgRNAs or when cells were transfected with a control plasmid. Our data support targeted acetylation as a causal mechanism of renin transactivation. CRISPR/Cas9 provides a tool to study the regulation of renin expression by targeting epigenetic marks in the promoter and enhancer of renin.
The physical layer security of uplink non-orthogonal multiple access (NOMA) is analyzed. A stochastic geometry approach is applied to analyze the coverage probability and the effective secrecy ...throughput (EST) of the kth NOMA user, where a fixed or an adaptive transmission rate can be used. A protected zone around the legitimate terminals to establish an eavesdropper-exclusion area. We assume that the channel state information associated with eavesdroppers is not available at the base station. We consider that the base station is equipped with multiple antennas. The impact of imperfect successive interference cancellation is also taken into account in this work. Our analysis allows an easy selection of the wiretap code rates that maximizes the EST. Additionally, our framework also allows an optimum selection of other system parameters like the transmit power or the eavesdropper-exclusion radius.
We present a general and tractable fading model for line-of-sight (LOS) scenarios, which is based on the product of two independent and non-identically distributed \(\kappa\)-\(\mu\) shadowed random ...variables. Simple closed-form expressions for the probability density function, cumulative distribution function and moment-generating function are derived, which are as tractable as the corresponding expressions derived from a product of Nakagami-\(m\) random variables. This model simplifies the challenging characterization of LOS product channels, as well as combinations of LOS channels with non-LOS ones. We leverage these results to analyze performance measures of interest in the contexts of wireless powered and backscatter communications, where both forward and reverse links are inherently of LOS nature, as well as in device-to-device communications subject to composite fading. In these contexts, the model shows a higher flexibility when fitting field measurements with respect to conventional approaches based on product distributions with deterministic LOS, together with a more complete physical interpretation of the underlying propagation characteristics.
A 33-year-old woman sought medical attention for a painful swelling of the left ankle. Plain radiographs revealed an osteolytic lesion involving the left distal tibia. An excisional biopsy provided ...the diagnosis of leiomyosarcoma in the tibia. A staging work-up was performed and an abdominal CT showed 4 liver hypodense lesions in both lobes with peripheral contrast enhancement. A liver biopsy confirmed the diagnosis of epithelioid hemangioendothelioma of the liver. No association between these two entities has been described before. This case introduces the importance of the pathological confirmation of apparent metastatic lesions in low grade sarcomas and provides a review of the literature of both tumours.
Resumen Introducción Las alteraciones en el habla aparecen en la mayoría de los pacientes con la enfermedad de Parkinson (EP) en el curso del trastorno. Su origen y gravedad son de interés clínico y ...diagnóstico. Objetivo Evaluar los patrones de deterioro en el habla en pacientes con la EP, e identificar diferencias en la velocidad de elocución y articulación en comparación con sujetos de control, empleando un método de análisis automático en una tarea de lectura. Pacientes Participaron 39 pacientes con la EP y 45 controles asintomáticos igualados en sexo y edad. Los pacientes con la EP, en estado on , no presentaban fluctuaciones motoras ni discinesias durante la evaluación del habla. Resultados El grupo de pacientes con la EP muestran una significativa reducción de la velocidad de elocución y articulación. No se encontraron correlaciones significativas entre los parámetros del habla estudiados y las características de los pacientes, tales como la dosis de L-dopa, duración del trastorno, edad, ni en las puntuaciones en las escalas UPDRS III o Hoehn y Yahr. Conclusiones Los pacientes con la EP muestran un patrón característico de deterioro del ritmo del habla. Estos resultados indican que las disfluencias en la EP son el resultado de la alteración del movimiento que afecta a la fisiología de los sistemas de producción del habla.
PDF
