Abstract In this article, a novel Compact Circularly Polarized Antenna with a notched circular Electromagnetic Band Gap (NCEBG) structure is put forward. This proposed structure comprises of a truncated rectangular patch antenna having its ground plane defected by slots etched on it to achieve compactness and wide impedance bandwidth. Electromagnetic Band Gap structures have the attractive feature of in-phase reflection and stopband creation for surface waves, enabling the surface waves to be suppressed; this, in turn, leads to enhanced performance of the antenna when loaded with such structures. For enhancing the functioning of the antenna with regard to its impedance bandwidth, axial ratio bandwidth and gain, seven NCEBG's are etched on the substrate which surrounds the truncated patch. Additionally, the antenna proposed in this research exhibits compactness with a low profile of 0.473 λo x 0.473 λo x 0.039 λo (λo at center frequency of 7.46GHz represents free space wavelength). The measured outcomes of the prototype-fabricated antenna match well with the results of the simulation, showing 3-dB axial ratio bandwidth of 13.66% and an impedance bandwidth of 73.29% having a peak gain of 7.32dBi in the operating band. The improved functioning of the proposed antenna marks it as a favorable applicant for wireless communication techniques and thus finding its application in various ways.

Abstract The presented model for wideband circularly polarized microstrip antenna is an improved version of the previous models which is widely applicable to satellite, microwave relay and radar. The designed circularly polarized antenna having overall volume of 20× 20 × 1.6 mm3 actively works at the impedance bandwidth of 9000 MHz (4.0–12.9 GHz) having 105%(with 8900 MHz taken as center frequency). The 3-dB axial ratio bandwidth is obtained as 5500 MHz (5.4–10.9 GHz) depicting 67.5% (with 8150 MHz taken as the center frequency). Measured results of impedance bandwidth, axial ratio, gain and VSWR agrees to the simulation results.

SUMMARY: Herbal extracts used for treatment of diabetes has focused mostly on the hypoglycaemic and anti-oxidant property.There are no studies which focused on its effect on dendritic architecture of pyramidal neurons of hippocampus caused by diabetes. This study was taken up to explore the effect of administration of Trigonella foenum-graecum (fenugreek) seed extract on diabetes induced dendritic atrophy in hippocampus. Experimental diabetes was induced in rats by administering single dose of Streptozotocin (60 mg/kg)intraperitoneally.Treatment groups of rats were orally administeredfenugreek seed extract of 1 g/kg body weight for 6 weeks. Followingly they were sacrificed and the brains were removed, processed for the Golgi-Cox stain method.The number of dendritic branching points and intersections were counted in successive radial segments of 20 µm up to a radial distance of 100 micron from soma and analysed by the Sholl’s method. The rats with diabetes showed a significant decrease in the dendritic length and branching points in most of the apical and basal dendrites of CA1 and CA3 pyramidal neurons.Treatment with fenugreek seed extract were able to significantly alleviate the dendritic atrophy in most of the segments except in the apical branching points of the CA1 neuron. The present study demonstrates that fenugreek seed extract having a proven hypoglycaemic and anti-diabetic property also possess protection to the hippocampal pyramidal neurons form diabetes associated neuronal atrophy.

RESUMEN: Los extractos de hierbas para el tratamiento de la diabetes se han basado principalmente en las propiedades hipoglucémicas y antioxidantes. En la literatura no hay estudios basados en su efecto sobre la arquitectura dendrítica de las neuronas piramidales del hipocampo, causadas por la diabetes. El objetivo de este estudio fue investigar el efecto de la administración de extracto de semilla de Trigonella foenum graecum (fenogreco) sobre la atrofia dendrítica inducida por la diabetes en el hipocampo. Se indujo diabetes experimental en ratas mediante la administración de una dosis única de estreptozotocina (60 mg / kg) por vía intraperitoneal. Se administró a grupos de ratas extracto de semilla de fenogreco a razón de 1 g / kg de peso corporal durante 6 semanas. Las ratas fueron sacrificadas posteriormente y se procesaron los cerebros mediante método de tinción de Golgi-Cox. El número de puntos de ramificación dendrítica e intersecciones se contaron en segmentos radiales sucesivos de 20 µm hasta una distancia radial de 100 micras del soma y se analizaron mediante el método de Sholl. Las ratas con diabetes mostraron una disminución significativa en la longitud dendrítica y los puntos de ramificación en la mayoría de las dendritas apicales y basales de las neuronas piramidales CA1 y CA3. El tratamiento con extracto de semilla de fenogreco alivió significativamente la atrofia dendrítica en la mayoría de los casos, excepto en los puntos de ramificación apical de la neurona CA1. El estudio demuestra que el extracto de semilla de fenogreco además de tener propiedades hipoglucémicas y antidiabéticas, también protege las neuronas piramidales del hipocampo contra la atrofia neuronal asociada a la diabetes.

Abstract Wideband, dual sense circularly polarized (CP), asymmetric circular slot fed by coplanar waveguide is proposed and designed. Dual polarizations are obtained by using a horizontal stub to the feed line and embedding the L-shaped strip onto the slotted ground plane. The simulated result of impedance bandwidth shows wideband performance is produced by four resonant modes. Some key parameters are studied to analyze the characteristics of the proposed antenna. The overall volume of the proposed antenna is 18 mm × 18 mm × 1.6 mm. The measured value of 10 dB impedance bandwidth is 112%at frequencies from 4.2 GHz to 14.9 GHz with voltage standing wave ratio (VSWR) ≤ 2. The 3-dB axial ratio bandwidths are 39.3% for the lower band which senses right-hand circular polarization (RHCP) and 2.8% for the upper band which senses left-hand circular polarization (LHCP) relative to the center frequency of 6.1GHz and 14.1 GHz, respectively. The proposed structure gives a good radiation pattern with moderate gain.