Computer aided design algorithm for singly fed circularly polarized rectangular microstrip patch antennas

Based on a resonant cavity model, this work presents an effective computer aided design (CAD) algorithm to design singly fed circularly polarized (CP) rectangular microstrip patch antennas. The CAD algorithm allows precise prediction of the antenna performance. The analysis of radiation pattern, input impedance, and axial ratio parameters confirm the success of the design. The experimental results from a manufactured prototype operating at 2.25 GHz are in good agreement with the CAD predictions. ©1999 John Wiley & Sons, Inc. Int J RF and Microwave CAE 9: 32–41, 1999.     

Ultrastructural Study of Platelet Behavior and Interrelationship in Sprouting and Intussusceptive Angiogenesis during Arterial Intimal Thickening Formation

Platelets in atherosclerosis, bypass stenosis, and restenosis have been extensively assessed. However, a sequential ultrastructural study of platelets in angiogenesis during the early phases of these lesions has received less attention. Our objective was the study of platelets in angiogenesis and vessel regression during intimal thickening (IT) formation, a precursor process of these occlusive vascular diseases. For this purpose, we used an experimental model of rat occluded arteries and procedures for ultrastructural observation. The results show (a) the absence of platelet adhesion in the de-endothelialized occluded arterial segment isolated from the circulation, (b) that intraarterial myriad platelets contributed from neovessels originated by sprouting angiogenesis from the periarterial microvasculature, (c) the association of platelets with blood components (fibrin, neutrophils, macrophages, and eosinophils) and non-polarized endothelial cells (ECs) forming aggregates (spheroids) in the arterial lumen, (d) the establishment of peg-and-socket junctions between platelets and polarized Ecs during intussusceptive angiogenesis originated from the EC aggregates, with the initial formation of IT, and (e) the aggregation of platelets in regressing neovessels (‘transitory paracrine organoid’) and IT increases. In conclusion, in sprouting and intussusceptive angiogenesis and vessel regression during IT formation, we contribute sequential ultrastructural findings on platelet behavior and relationships, which can be the basis for further studies using other procedures.     

Volume-Independent Sodium Toxicity in Peritoneal Dialysis: New Insights from Bench to Bed

Sodium overload is common in end-stage kidney disease (ESKD) and is associated with increased cardiovascular mortality that is traditionally considered a result of extracellular volume expansion. Recently, sodium storage was detected by Na23 magnetic resonance imaging in the interstitial tissue of the skin and other tissues. This amount of sodium is osmotically active, regulated by immune cells and the lymphatic system, escapes renal control, and, more importantly, is associated with salt-sensitive hypertension. In chronic kidney disease, the interstitial sodium storage increases as the glomerular filtration rate declines and is related to cardiovascular damage, regardless of the fluid overload. This sodium accumulation in the interstitial tissues becomes more significant in ESKD, especially in older and African American patients. The possible negative effects of interstitial sodium are still under study, though a higher sodium intake might induce abnormal structural and functional changes in the peritoneal wall. Interestingly, sodium stored in the interstial tissue is not unmodifiable, since it is removable by dialysis. Nevertheless, the sodium removal by peritoneal dialysis (PD) remains challenging, and new PD solutions are desirable. In this narrative review, we carried out an update on the pathophysiological mechanisms of volume-independent sodium toxicity and possible future strategies to improve sodium removal by PD.     

Ncx3-Induced Mitochondrial Dysfunction in Midbrain Leads to Neuroinflammation in Striatum of A53t-α-Synuclein Transgenic Old Mice

The exact mechanism underlying selective dopaminergic neurodegeneration is not completely understood. The complex interplay among toxic alpha-synuclein aggregates, oxidative stress, altered intracellular Ca²⁺-homeostasis, mitochondrial dysfunction and disruption of mitochondrial integrity is considered among the pathogenic mechanisms leading to dopaminergic neuronal loss. We herein investigated the molecular mechanisms leading to mitochondrial dysfunction and its relationship with activation of the neuroinflammatory process occurring in Parkinson’s disease. To address these issues, experiments were performed in vitro and in vivo in mice carrying the human mutation of α-synuclein A53T under the prion murine promoter. In these models, the expression and activity of NCX isoforms, a family of important transporters regulating ionic homeostasis in mammalian cells working in a bidirectional way, were evaluated in neurons and glial cells. Mitochondrial function was monitored with confocal microscopy and fluorescent dyes to measure mitochondrial calcium content and mitochondrial membrane potential. Parallel experiments were performed in 4 and 16-month-old A53T-α-synuclein Tg mice to correlate the functional data obtained in vitro with mitochondrial dysfunction and neuroinflammation through biochemical analysis. The results obtained demonstrated: 1. in A53T mice mitochondrial dysfunction occurs early in midbrain and later in striatum; 2. mitochondrial dysfunction occurring in the midbrain is mediated by the impairment of NCX3 protein expression in neurons and astrocytes; 3. mitochondrial dysfunction occurring early in midbrain triggers neuroinflammation later into the striatum, thus contributing to PD progression during mice aging.     

Liquid limit of low- to medium-plasticity soils: comparison between Casagrande cup and cone penetrometer test

For liquid limit determination, the European Standards require the cone penetrometer technique or, alternatively, the Casagrande cup method; but the latter is widely used in practice. As most European soil classification systems are not adapted to the new European Standards, a systematic study was carried out to verify the differences between the two techniques for liquid limit determination, examining clayey soils from various geologic units. Comparison of 100 liquid limit values ranging between 20 and 50% indicates that the liquid limit obtained by the fall cone method is generally 2.2% points higher than that obtained by the hard base Casagrande apparatus. Comparison of data from different sources consistently indicates that the equation proposed in this study may be useful in revising existing soil classification systems, avoiding problems of soil classification due to the technique used for liquid limit determination.     

Effect of nucleation mechanism on complex poly(L‐lactide) nonisothermal crystallization process,part 2: Crystallization kinetics analysis

In the first part of this article, we reported the crystalline memory effect on the nonisothermal crystallization of poly(L ‐lactide). The experiments were carried out by using polymer single crystals growth from dilute solution as standard starting material. In this article (Part II), we have analyzed in detail the effect of the melting condition on the overall crystallization kinetics by applying the Nakamura‐Avrami model to DSC results. The absence or the low concentration of foreign infusible heterogeneous nuclei in our system allowed us to exalt the self‐nuclei role in polymer crystallization, to follow their concentration decrease during the melting process and to find the limiting melting temperature for their disappearance. Below such a temperature, a stable equilibrium number of self‐nuclei was observed, probably deriving from ordered structures, persisting in the melt, and originated from the single crystals thickening process during the polymer dynamic melting in the DSC. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Cow colostrum and early milk enriched with eicosapentaenoic and docosahexaenoic fatty acid

The objective of the study was to explore whether it is possible to alter cow colostrum and early milk fatty acid composition with a low level of fat supplement, high in docosahexaenoic (DHA) and eicosapentaenoic (EPA) fatty acid. Diets included a control diet and a diet supplemented with DHA- and EPA-enriched fat supplement. Addition of fat supplement significantly decreased saturated fatty acids, C14:0 and C16:0 and increased the values of monounsaturated fatty acids, polyunsaturated fatty acids (PUFA), n3 fatty acids, EPA, DHA, C18:1n9cis and C18:1n11trans. The percentage of short-chain fatty acids significantly increased with the progress of lactation, while the percentage of PUFA, n3 and n6 significantly decreased. These results showed that fat supplement, high in DHA and EPA, modified the fatty acid profile of colostrum and milk fat and increased the proportion of beneficial fatty acids for human health.