A retrospective study to assess the risk of bladder cancer in type-2 diabetic patients treated with pioglitazone.

INTRODUCTION: Pioglitazone has been a cornerstone of oral hypoglycemic therapy. Concerns have been raised about its association with urinary bladder cancer. Considering the wide usage of this drug, concrete and multiple population-based studies are needed to establish the safety of this drug. The present retrospective study is aimed to assess the association of pioglitazone with urinary bladder cancer. MATERIALS AND METHODS: Clinical records of 4170 patients (2085 pioglitazone users and similar number of nonpioglitazone users) attending the diabetes clinic at a tertiary level teaching hospital were accessed, and the patients were subjected to symptom-directed questionnaire, urine examination, and cystoscopy and bladder biopsy (whenever clinically indicated). The risk of bladder cancer was also assessed with respect to cumulative dose and duration of pioglitazone. RESULTS: We did not observe any increased risk of bladder malignancy with pioglitazone exposure; furthermore, there was no association with cumulative dose and duration of pioglitazone therapy. Pioglitazone was found to be effective and safe in managing glycemic control in diabetic patients.

Granuloma annulare: A rare dermatological manifestation of diabetes mellitus.

Granuloma annulare (GA) is usually a self-limited, benign granulomatous disease of the dermis and subcutaneous tissue. It's generalized or disseminated form is associated with underlying diabetes mellitus and at times it precedes the sign and symptoms of diabetes mellitus. We are reporting a case of a 56-year-old female, who is a known case of type 2 diabetes mellitus she presented to us with symmetric lesions on her trunk, arms, and legs. On further evaluation by the dermatologists, it was established to be lesions of GA. This case has been reported to highlight the incidence and the importance of recognition of this common but rarely diagnosed condition.

In-parallel resonators to increase the absorption of subwavelength acoustic absorbers in the mid-frequency range.

The acoustic effects of in-parallel resonators is compared to the behavior of a classical single degree of freedom resonator for which the resistance and the mass are in series. In-parallel resonators serve to enhance the acoustic absorption for mid-frequencies thereby extending the active frequency range of perfect acoustic absorbers. Two implementations of these in-parallel absorbers are presented and investigated experimentally as well as numerically. In the first demonstration, the resistance is a perforated plate with a wiremesh and the oscillating mass is the air that fills a tube passing through the plate. The second implementation consists of a thin flexible beam that oscillates and where the resistance is due to the micro-slit resulting from the cutting of the beam.

Using liner surface modes in acoustic ducts to make obstacles reflectionless.

Acoustic cloaking for the suppression of backscattering inside ducts is proposed in the audible range where plane waves are curved around the object using the surface modes of the liner. It is numerically shown that a slowly varying resonant liner (e.g. based on an array of tubes) creates a zone of silence in which an object of arbitrary shape can be acoustically hidden for a wide range of frequencies. And then, a resonant liner has deflecting properties without reflection of the wavefront, which are close to an ideal invisibility cloak. This kind of cloaking is effective in a wide frequency band and the cloaking band is a function of the impedance and height of the obstacle relative to the conduit. For smooth shaped obstacles, there is an ability of the object to help hide itself, which increases the cloaking frequency band (self-cloaking). Dispersion effects lead to slow sounds and distortion of the wave phase.

Explicit approximation of the wavenumber for lined ducts.

For acoustic waves in lined ducts, at given frequencies, the dispersion relation leads to a transcendental equation for the wavenumber that has to be solved by numerical methods. Based on an Eckart explicit expression initially derived for water waves, accurate explicit approximations are proposed for the wavenumber of the fundamental mode in lined ducts. While the Eckart expression is 5% accurate, some improved approximations can reach maximum relative errors of less than 10-8. The cases with small dissipation parts in the admittance of the liner and/or axisymmetric ducts are also considered.

Linezolid-induced dental hyperpigmentation in an adult male being treated for an ulcer caused by atypical mycobacteria.

Mycobacteria are intrinsically resistant to most antibiotics as a result of multiple mechanisms. Linezolid, a member of the oxazolidinones, is a newer class of synthetic antimicrobials which is frequently used to treat mycobacteria. Here, we report a case of a patient with an ulcer on the right arm, caused by atypical mycobacteria, who presented with discoloration of both the upper and lower teeth after being treated with linezolid for a period of 2 months. On detailed evaluation, the patient was found to have linezolid-induced dental hyperpigmentation. This is the first case reported ever in an adult having linezolid-induced dental hyperpigmentation.

Validation of low frequency noise attenuation using locally resonant patches.

Since conventional silencers in acoustic ducts have problems of size limitations at low frequencies and being prone to high backpressure, locally resonant aluminum patches are introduced in acoustic duct walls aiming at creating frequency stop bands in the low frequency region (below 1 KHz). With these flush mounted patches, promising noise reductions, with no such drawbacks, can be obtained, building on local resonance phenomenon implemented in acoustic metamaterials techniques. The objective of the current paper is to experimentally validate the performance of an array of flexible side-wall-mounted patches inside ducts. The experimental results are compared with Analytical Green's function method as well as Numerical Finite Element Method and a close agreement was found. The results show that the presence of the patches singly or periodically can play a prominent role in designing any acoustic bandgap materials. The effect of the arrays of patches on the effective dynamic density and bulk modulus has also been investigated.

Sound attenuation in ducts using locally resonant periodic aluminum patches.

In recent years, the control of low frequency noise has received a lot of attention for several applications. Traditional passive noise control techniques using Helmholtz resonators have size limitations in the low frequency range because of the long wavelength. Promising noise reductions, with flush mounted aluminum patches with no size problems can be obtained using local resonance phenomenon implemented in acoustic metamaterial techniques. The objective of this work is to introduce locally resonant thin aluminum patches flush mounted to a duct walls aiming at creating frequency stop bands in a specific frequency range. Green's function is used within the framework of interface response theory to predict the amount of attenuation of the local resonant patches. The two-port theory and finite elements are also used to predict the acoustic performance of these patches. No flow measurements were conducted and show good agreement with the models. The effect of varying the damping and the masses of the patches are used to expand the stop bandwidth and the effect of both Bragg scattering and the locally resonant mechanisms was demonstrated using mathematical models. The effect of the arrays of patches on the effective dynamic density and bulk modulus has also been investigated.

Low frequency sound attenuation in a flow duct using a thin slow sound material.

A thin subwavelength material that can be flush mounted in a duct and that gives an attenuation band at low frequencies in air flow channels is presented. To decrease the material thickness, the sound is slowed in the material using folded side branch tubes. The impedance of the material is compared to the optimal value given by the Cremer condition, which can differ greatly from the air characteristic impedance. Grazing flow on this material increases the losses at the interface between the flow and the material.