Prevalence of Microalbuminuria in Non-diabetic Hypertensive Patients and its Correlation with Changes in Left Ventricular and Left Atrial Characteristics.

BACKGROUND: Microalbuminuria is urinary albumin excretion in the range of 30-300 mg per 24 hours and is considered as an abnormal albumin excretion rate. Microalbuminuria is associated with epithelial dysfunction and have a high risk for target organ damage resulting in stroke, retinopathy and adverse cardiovascular events. The objective of the study was to determine the prevalence of microalbuminuria in non-diabetic hypertensive patients and its correlation with cardiovascular changes. METHODS: A quantitative cross-sectional study was done in 107 participants diagnosed as non-diabetic hypertensive patients visiting to Manmohan Memorial medical college and Teaching hospital and Manmohan Cardio-thoracic Vascular and transplant Centre. The assessed parameters were basic metabolic profile, urine evaluation and Echocardiography. RESULTS: The results showed microalbuminuria in 28 study participants and not seen in 79 participants. Similarly, microalbuminuria was observed more comparable in those with presence of left ventricular hypertrophy as compared to the absence of left ventricular hypertrophy (29.3% versus 22.8%) (p value 0.469); those with presence of left ventricular diastolic dysfunction as compared to the absence of left ventricular diastolic dysfunction (31.1% versus 19%) (p value 0.170) and those with dilated left atrium as compared to normal left atrium (26.7% versus 23.9%) (p value 0.820). In case of left ventricular ejection fraction, those with normal left ventricular ejection fraction (26.3%) had slightly higher proportion of micro-albuminuria than those with mild to moderate left ventricular systolic dysfunction (20%) (p value= 0.755) Conclusions: There was no significant difference in the level of micro-albuminuria between non-diabetics, hypertensive patients with cardio vascular changes compared to patients with no cardiovascular changes.

Design, development and characterization of resistive arm based planar and conformal metasurfaces for RCS reduction.

This paper reports the design, development and characterization of a broadband, polarization insensitive metasurface absorber in planar, cylindrically bent and 90° dihedral surface geometry. Four metallic patches loaded with eight lumped resistors are used, which has been optimized numerically using CST MICROWAVE STUDIO, as a unit cell of developed metasurface absorber, to achieve 20 dB reflection reduction for 51.21% fractional bandwidth (13.42-22.66 GHz) under normal incidence with 0.12 [Formula: see text] thickness (where [Formula: see text] corresponds to lower operating frequency). The numerical findings are also verified analytically using equivalent circuit analysis, which exhibits very good agreement. Polarization-insensitive characteristics are achieved using fourfold rotation symmetry of the designed structure. The fabricated prototype of the designed absorber is experimentally characterized, using free space measurement method and ABmm vector network analyzer (VNA) system, and fairly good agreement with numerical-analytical findings are reported. The major novelty of this study is the design and development of a broadband (13.42-22.66 GHz), polarization insensitive metasurface absorber that provides 20 dB reflection reduction numerically as well as experimentally in the whole band, which to the author's knowledge has not been observed till now. Also, keeping in mind the radar stealth applications, first time we have demonstrated both numerically and experimentally, different geometrical shapes of conformal metasurfaces that can be practically used in actual scenario.

Slowing and stopping of wave in dispersive metamaterial loaded helical guide.

We propose a dispersive metamaterial loaded helical waveguide (DMLHG) structure that supports slowing and stopping of Electromagnetic (EM) wave. Analytical and computational characterizations have been done to visualize various modal characteristics in detail using the Drude model as a dispersive parameter. It is observed that metamaterial insertion enhances helical guide slow wave behaviour and it supports both forward wave (FW) and backward wave (BW) as well as mode degeneracy. Obtained mode degeneracy mechanism leads to trapping of EM wave. The proposed guide structure provides a dynamic control of wave velocity by varying its physical parameters. Two possible structures are designed and simulated using CST Microwave Studio Software. The simulation results verify the presence of similar characteristics as observed in analytical study such as FW, BW, mode-degeneracy, but in slightly shifted frequency spectrum.

Propagation characteristics of an extremely anisotropic metamaterial loaded helical guide.

In this study, we report slow wave propagation characteristics of an extremely anisotropic metamaterial loaded helical guide (EAMLHG). An analytical expression has been theoretically derived and numerically computed to get exact solutions of all possible guided modes of propagation. Anisotropy is defined in terms of positive longitudinal permittivity (ϵz > 0) and negatives transverse permittivity value (ϵt < 0). The waveguide supports hybrid (HE) mode propagation and possesses characteristics of backward wave (BW) mode, forward wave (FW) mode, zero-group velocity and mode-degeneracy. The large value of effective index of BW mode and mode-degeneracy mechanism leads to slowing and trapping of electromagnetic (EM) wave. Closed-form guided mode energy propagation expressions has been also derived and computed which exhibits zero power flow at mode degeneracy point. A comparative study is also carried out between extremely anisotropic metamaterial helical waveguide (EAMLHG) and conventional extremely anisotropic metamaterial cylindrical guide (EAMCG), which reveals enhanced slow wave behaviour. Engineering feasible design and analysis is also presented by combining alternate disks of silver and glass as an extremely anisotropic medium which exhibits lossy and dispersive properties. This type of waveguide can find applications as a filter, phase shifter, and delay lines in microwave to THz applications and, as an optical buffer in optoelectronics applications.

Hyper-competition, collusion, free riding or coopetition: basins of attraction when firms simultaneously compete and cooperate.

Using a dyad in a homogeneous market, facing investment decisions, we investigate simultaneous competition and cooperation behavior of firms under the effects of (a) government policies that send signals regarding incentives for different levels of competition and cooperation and (b) two different 'states of nature' for the market, i.e., one that rewards firms for building on their existing strategic path and another that rewards firms for exploring new strategies. We conceptualize the dyad and the external environment as a complex adaptive system and formulate simultaneous competition and cooperation as a dynamic duopoly game with variable demand and supply curves. Employing a simulation-based methodology, we investigate the attractors of this two-firm system. We find that in markets that reward firms for building on their existing strategic path, coopetition (sustained simultaneous competition and cooperation) is a common attractor and the system is not affected by imbalances in governmental policies. On the other hand, in markets that reward firms for exploring new strategy, competition is rare; rather, the system frequently exhibits hyper-coopetition, collusion or freeridership. Additionally, we find that the market share of firms as well as a firm's initial disposition toward competition and cooperation are important factors that affect the outcome.