19 research outputs found
Effects of spironolactone on proteinuria of patients with type 2 diabetes
Background: Diabetic nephropathy is the most common cause of kidney failure. We investigated the beneficial effects of spironolactone, alone and in combination with hydrochlorothiazide, on diabetic nephropathy. Methods: This randomized clinical trial was conducted on 60 type 2 diabetic patients with nephropathy. The patients were allocated to three groups of 20 to receive spironolactone (50 mg/d) plus placebo, spironolactone (50 mg/d) plus hydrochlorothiazide (25 mg/d), or placebo plus hydrochlorothiazide (25 mg/d). The duration of the study was three months. Measurements of 24-hour urine protein and other markers were performed at start and end of the study. Findings: Of 60 patients, 43 were male. The mean age of patients was 56.8 ± 8.3 years. The three groups were homogeneous regarding general factors. At the end of the study, a significant difference in proteinuria was observed between the groups. In the groups that received spironolactone, the mean 24-hour urine protein was reduced (200 mg/24h). However, there was no significant change in the last group. The mean serum potassium in the first group showed a significant increase (0.26 meq/l). However, there were no significant increases in the second and third groups. Conclusion: This investigation showed that spironolactone plus hydrochlorothiazide had a significant effect on reducing proteinuria without causing hyperkalemia and renal failure in patients with glomerular filtration rate > 50 cc/min. Therefore, spironolactone can serve as a renoprotective drug in diabetic nephropathy
Association of serum uric acid with proteinuria in type 2 diabetic patients
Background: Various findings suggest that uric acid is an inflammatory factor and may have a role in endothelial dysfunction and act as a mediator of diabetic nephropathy. The objective of this study was to evaluate the relationships between serum uric acid level and level of proteinuria in type 2 diabetic (T2D) patients. Materials and Methods: A cross-sectional analytical study was conducted in 60 patients with T2D without a history of gout. None was treated with allopurinol. Venous blood samples were obtained in fasting state for determinations of serum creatinine, uric acid, and hemoglobin A(1c) (HbA(1c)) (reference range 3.8-5.5%); 24-h urine proteinuria was also measured. Results: Mean age of the patients was 57 +/- 8.3 years. Mean +/- standard error (SE) of serum creatinine was 0.98 +/- 0.028 mg/dL, mean +/- SE of serum uric acid was 4.5 +/- 0.15 mg/dL, and mean +/- SE of proteinuria was 388 +/- 28.7 mg/day (median = 303.5 mg/day). There was no significant difference in serum uric acid, HbA(1c), and creatinine level between males and females (P > 0.05). There was a significant positive association between body mass index (BMI) and serum uric acid levels (r = 0.428, P = 0.001). After adjustment for weight, a significant positive association of serum uric acid with level of proteinuria was seen (r = 0.47, P < 0.001). Conclusion: Serum uric acid had a significant positive association with diabetic nephropathy. It might be hypothesized that serum uric acid plays a role in diabetic nephropathy in T2D
Beamwidth Control of a Helical Antenna Using Truncated Conical Plasma Reflectors
International audienceThis paper presents an approach to simultaneous beamwidth and gain control in a circular-polarization helical antenna using a truncated conical plasma reflector. Requirements and trade-offs regarding the feasible structure of the antenna are discussed. Performance of the proposed antenna is confirmed by full-wave simulations. The results show that the proposed plasma reflector can be used to improve the radiation gain of the considered helical antenna up to around 17%. © 2020 EurAAP
Ultra-High-Resistance Pseudo-Resistors With Small Variations in a Wide Symmetrical Input Voltage Swing
This brief presents a new strategy and circuit configuration composed of serially-connected PMOS devices operating in the subthreshold region for implementing ultra-high-value resistors required in very low-frequency active-RC filters and bio-amplifiers. Depending on the application, signal bandwidth for instance in bio-amplifiers may vary from a few mHz up to a maximum of 10 kHz. Three different resistor structures are proposed to achieve ultra-high resistance. While ranging in the order of several T Ω, the proposed ultra-high-resistance pseudo-resistors occupy a small on-chip silicon area, which is one of the main issues in the design of analog front-end circuits in ultra-low power implantable biomedical microsystems. In addition, these ultra-high-value resistors lead to the use of a small capacitance to create a very small cut-off frequency. Therefore, the large area to implement capacitances is also considerably reduced. The proposed resistor structures have very small variations about 7% and 12% in a wide input voltage range (-0.5 V+0.5 V), thus significantly improving the total harmonic distortion of bio-amplifiers and the analog front-end of the system. Simulation results of different circuits designed in a 180nm CMOS technology, are shown to demonstrate the advantages of the proposed ultra-high-resistance pseudo-resistors.This work was supported in part by Grant PID2019-103876RB-I00, funded by MCIN/AEI/10.13039/501100011033, by the European Union ESF Investing in your future, and by ”Junta de Andalucia” under Grant P20-00599.Peer reviewe
Coplanar waveguides loaded with s-shaped split-ring resonators: modeling and application to compact microwave filters
This letter studies the transmission characteristics of coplanar waveguides (CPWs) loaded with single-layer S-shaped split-ring resonators (S-SRRs) for the first time. Two structures are analyzed: 1) a CPW simply loaded with an S-SRR, and 2) a CPW loaded with an S-SRR and a series gap. The former exhibits a stopband functionality related to the resonance of the S-SRR excited by the contra-directional magnetic fluxes through the two connected resonator loops; the latter is useful for the implementation of compact bandpass filters. In both cases, a lumped-element equivalent circuit model is proposed with an unequivocal physical interpretation of the circuit elements. These circuits are then validated by comparing the circuit response with extracted parameters to full-wave electromagnetic simulations. The last part of the letter illustrates application of the S-SRR/gap-loaded CPW unit cell to the design of a bandpass filter. The resulting filter is very compact and exhibits competitive performance.Ali K. Horestani, Miguel Durán-Sindreu, Jordi Naqui, Christopher Fumeaux, and Ferran Marti
Bandpass filters based on coupled split ring resonators for surface waves on planar Goubau lines
This paper demonstrates a method for enhancing the performance of recently introduced compact bandpass filters for terahertz surface waves on single wire waveguides, the socalled planar Goubau lines (PGLs). It is firstly shown numerically and validated experimentally that a gapped PGL loaded with a pair of split ring resonators (SRRs) acts as a bandpass filter. The concept and simulation result are validated through experiment. Furthermore, in order to achieve an improved frequency response, a third-order filter based on coupled SRRs is proposed. It is shown that while the size of the proposed filter is further reduced, it additionally benefits from a higher inband transmission, improved selectivity, and a controllable wide bandwidthAli K. Horestani, Withawat Withayachumnankul, Abdallah Chahadih, Abbas Ghaddar, Mokhtar Zehar, Derek Abbott, Tahsin Akalin, and Christophe Fumeau
Metamaterial-inspired bandpass filters for terahertz surface waves on Goubau lines
This paper is focused on the application of split ring resonators (SRRs) to the design of compact bandpass filters for terahertz surface waves on single-wire waveguides, the so-called planar Goubau lines (PGLs). Through equivalent circuit models, electromagnetic simulations, and experiments, it is shown that, while a pair of SRRs coupled to a PGL inhibits the propagation of surface waves along the line, introducing a capacitive gap to the PGL switches the bandstop behavior to a bandpass behavior. In order to highlight the potential application of the proposed structure to the design of practical higher order terahertz bandpass filters, two types of compact bandpass filters are designed and fabricated: 1) third-order periodic bandpass filters based on SRR/gap-loaded PGL and 2) coupled-resonator bandpass filters. It is shown that, while the frequency response of the both filter types can be controlled by altering the physical dimensions of the structure, a wider bandwidth can be achieved from the coupled-resonator filters. The design concept and simulation results are validated through experiments.Ali K. Horestani, Withawat Withayachumnankul, Abdallah Chahadih, Abbas Ghaddar, Mokhtar Zehar, Derek Abbott, Christophe Fumeaux and Tahsin Akali
Toxic and essential elements in drinking water, blood, hair and intestinal tissues of ulcerative colitis patients: probabilistic health risk assessment for drinking water consumers
Environmental exposure to heavy metals is a well-known risk factor for cancers. In this study, the content of toxic and essential elements (Pb, Ni, As, Cu, Zn, Fe, and Se) in drinking water, blood, hair, and intestinal tissues of ulcerative colitis (UC) patients was examined. The results demonstrated that the mean concentration of the elements in clinical samples was in the order of intestinal tissue > hair > blood. Health risk assessment showed that As and Pb in drinking water of UC patients may pose non-carcinogenic risk. Also, there is possible cancer risk to drinking water consumers for As. The potential high health risks and the significant correlation between the elements contents of drinking water and clinical samples imply that such environmental pollution should not be overlooked in Chaharmahal-Va-Bakhtiari province, Iran. Special attention should be paid on As pollution of drinking water due to its high canrcinogenic risk (CR), probably on UC tissues
Influence of metal ions concentration in drinking water in the development of ulcerative colitis
Ulcerative colitis (UC) imposes high economic burden to the health systems. However, the risk factors for development of the disease are still remained unknown. Exposure to heavy metals may be associated with occurrence of UC. The aim of this study was to evaluate the relationship between the concentration of metal(loid)s including Pb, As, Ni, Cu, Zn, Fe, and Se in drinking water with incidence of UC. To do this, 35 biopsy samples were each taken from patients and healthy subjects along with the same number of samples of their drinking water. The furnace atomic absorption spectrophotometry was used for sample analysis. Our results showed that exposure to Pb, As, Cu, and Fe was associated with occurrence of UC (ORs > 1; P < 0.05); meanwhile, the concentrations of Zn and Ni were higher in healthy subject biopsies than UC patients (ORs < 1; P < 0.05). Also, the mean concentration of Pb in the drinking water samples (0.12 ± 0.07 mg/L) was higher than the permissible limit of the Institute of Standards and Industrial Research of Iran (ISIRI). The results showed that by increasing Pb in drinking water, Zn concentration in the intestinal tissues of patients was decreased (P = 0.005). However, the concentration of Pb, As, Cu, and Fe in UC patients may affect the exacerbation of the disease, though Zn may potentially reduce the risk of this disease. In conclusion, our findings demonstrated that exposure to the metal ions through drinking water can affect the body’s heavy metal content, which may be act as preventing or developing factors for UC
Toxic and essential elements in drinking water, blood, hair and intestinal tissues of ulcerative colitis patients: probabilistic health risk assessment for drinking water consumers
Environmental exposure to heavy metals is a well-known risk factor for cancers. In this study, the content of toxic and essential elements (Pb, Ni, As, Cu, Zn, Fe, and Se) in drinking water, blood, hair, and intestinal tissues of ulcerative colitis (UC) patients was examined. The results demonstrated that the mean concentration of the elements in clinical samples was in the order of intestinal tissue > hair > blood. Health risk assessment showed that As and Pb in drinking water of UC patients may pose non-carcinogenic risk. Also, there is possible cancer risk to drinking water consumers for As. The potential high health risks and the significant correlation between the elements contents of drinking water and clinical samples imply that such environmental pollution should not be overlooked in Chaharmahal-Va-Bakhtiari province, Iran. Special attention should be paid on As pollution of drinking water due to its high canrcinogenic risk (CR), probably on UC tissues