Search

Immunoglobulin A nephropathy (IgAN) has been well studied among young people, but few data on clinicopathological characteristics, treatment response and outcomes for elderly IgAN patients are available. A cohort study of elderly IgAN patients was performed. The combined endpoints of renal outcome were a 50% decline in eGFR compared with the time of renal biopsy, end-stage kidney disease and/or death. Risk factors associated with poor renal outcomes were then determined. The benefits of immunosuppressant therapies were also evaluated by Kaplan-Meier survival curve analysis. This study ultimately included 126 elderly patients with IgAN. Comparison between the endpoint and non-endpoint groups indicated that patients with poor outcomes had more severe clinical features, such as worse kidney function, severe hematuria and lower albumin levels. Cox regression analysis indicated that age (HR 1.15, 95% CI 1.02–1.29, p = 0.021), male gender (HR 9.71, 95% CI 1.00–97.56, p = 0.050), and urine red blood cells (HR 1.003, 95% CI 1.000–1.006, p = 0.029) were independent risk factors for poor renal outcome in elderly IgAN patients. To explore possible reasons accounting for the predictive value of age and sex, patients were divided into two groups based on these two variables. Patients in the geriatric group had lower serum albumin, estimated glomerular filtration rate, hemoglobin and aspartate aminotransferase levels than those in the quinquagenarian group. Male patients tended to have higher hemoglobin, higher alanine aminotransferase, and lower triglycerides and cholesterol levels than female patients. To investigate different treatment responses, patients were classified into two groups depending on treatment strategies (renin-angiotensin system inhibitors and immunosuppressive therapy), and the survival analysis indicated no significant difference in kidney outcome between the two groups (p > 0.05). This result still holds after adjusting for age, sex, eGFR, hematuria, and proteinuria. Advanced age, male, and hematuria might be independently associated with poor kidney outcomes in elderly patients with IgAN. Immunosuppressive therapy might confer no overall benefit to older IgAN patients. [ABSTRACT FROM AUTHOR]

This article is concerned with the problem of scattering of time-harmonic acoustic waves from an impenetrable periodic structure in a periodic layered medium. Having established the well-posedness of the direct problem by the integral equation method, we show that the measurements, corresponding to a countably infinite number of incident quasi-periodic waves above the structure, uniquely determine both the penetrable periodic interface and the impenetrable periodic structure together with its physical property. To this end, an important role is played by a priori estimates of the solution and a mixed reciprocity relation for the direct problem. [ABSTRACT FROM AUTHOR]

This article is concerned with uniqueness for reconstructing a periodic inhomogeneous medium sitting on a perfectly conducting plate. We deal with the problem in the framework of time-harmonic Maxwell systems without TE or TM polarization. An orthogonal relation is obtained for two refractive indices and then used to prove that the refractive index can be uniquely identified from a knowledge of the incident fields and the total tangential electric field on a plane above the inhomogeneous medium, utilizing the eigenvalues and eigenfunctions of a quasi-periodic Sturm-Liouville eigenvalue problem. [ABSTRACT FROM AUTHOR]

A new topology of the power dividers is proposed, which has both good isolation performance and tunable wideband filtering. Based on the Wilkinson structure, on the one hand, to achieve good performance wideband port-to-port isolation, the two output ports are first connected in parallel through a resistor, and then through a quarter-wavelength parallel coupled line and transmission line. On the other hand, in order to realize the tunable wideband filtering response, a reconfigurable wideband filtering branch is formed, including stepped impedance open-circuit stubs, parallel coupled lines, and t-type tunable reflectors. The power divider prototype is theoretically calculated and verified by the odd-even mode method. The measurement results show that the tunable wideband filtering power divider centered at 3 GHz with a 66.7% fractional bandwidth, output port isolation maximum 15.8 dB, a return loss greater than 15 dB, while achieving wideband tunable in the range of about 0.6 GHz. [ABSTRACT FROM AUTHOR]