Preparation of nanosize polyaniline and its utilization for microwave absorber.

Polyaniline powder in nanosize has been synthesized by chemical oxidative route. XRD, FTIR, and TEM were used to characterize the polyaniline powder. Crytallite size was estimated from XRD profile and also ascertained by TEM in the range of 15 to 20 nm. The composite absorbers have been prepared by mixing different ratios of polyaniline into procured polyurethane (PU) binder. The complex permittivity (epsilon' - jepsilon") and complex permeability (mu' - jmu") were measured in X-band (8.2-12.4 GHz) using Agilent network analyzer (model PNA E8364B) and its software module 85071 (version 'E'). Measured values of these parameters were used to determine the reflection loss at different frequencies and sample thicknesses, based on a model of a single layered plane wave absorber backed by a perfect conductor. An optimized polyaniline/PU ratio of 3:1 has given a minimum reflection loss of -30 dB (99.9% power absorption) at the central frequency 10 GHz and the bandwidth (full width at half minimum) of 4.2 GHz over whole X-band (8.2 to 12.4 GHz) in a sample thickness of 3.0 mm. The prepared composites can be fruitfully utilized for suppression of electromagnetic interference (EMI) and reduction of radar signatures (stealth technology).

Routine radio-imaging in filarial chyluria--is it necessary in developing countries?

Chyluria is a common presentation of filariasis in developing countries and mostly affects economically poor classes. The judicious use of investigations is mandatory to keep the cost of treatment acceptable. A modified plan is suggested for managing such patients without using retrograde pyelography or lymphangiography. A total of 54 patients were studied at 2 separate institutions, with retrograde pyelography being carried out at one institution but not at the other. All patients were treated primarily by the instillation of 1% silver nitrate, with an initial success rate of 70%. Eight patients who failed to respond underwent pyelolymphatic disconnection, the success rate being 88%. The omission of retrograde pyelography and lymphangiography had no effect on either treatment or outcome. The value of these radio-imaging techniques is discussed.

Effects of scrotal hydrocele over testicular histology.

Forty four biopsies were performed on testes during hydrocele operations. They show alteration in 52.2 percent of the biopsies. There is variable effect of size and duration of hydrocele on the morphogenesis of testes. However, size and duration are not the only influencing factors and there is need to analyse the histological changes in hydrocele of different etiology.

Repair of prostatomembranous urethral strictures by a bulboprostatic intussusception technique.

The repair of post-traumatic strictures of the prostatomembranous urethra in 22 patients by a bulboprostatic intussusception technique is described. Minor wound infection occurred in 12 patients. No other complications were encountered in up to 5 years of follow-up. This operation is a useful and relatively easy technique for dealing with all but the very long strictures of this region.

Alterations in testicular functions in patients of scrotal hydrocele.

Forty three randomly selected patients of scrotal hydrocele were investigated for alterations in functions of the testes. FSH and LH levels were raised in 50 and 75 per cent of patients respectively whereas testosterone level was found subnormal in 14 of the 28 patients in whom hormone profile was studied. LH and FSH levels also showed some relation with duration and size of the hydrocele. Similarly, sperm concentration and their motility was found affected by the duration of the disease.