Poly(lactic acid) (PLA) was synthesized using condensation polymerization of L-lactic acid using a controlled ultrasonic cavitation technique. Polystyrene (PS) was used to prepare the PS:PLA and PS:PLA:organically modified montmorillonite (OMMT) composites. PS was dissolved in benzene (10:90) and kept overnight for dissolution. Meanwhile, surface modification of montmorillonite was done using a column chromatography technique and referred to as OMMT. The d-spacing was found to be 22 Å after modification due to sufficient column length and diameter with good retention time during ion exchange. PLA and OMMT were kept in hot air oven at 100 o C for 30 min to remove the moisture. The mixtures of 10%, 15%, 20%, 25%, and 30% of PS:PLA:OMMT were subjected to ultrasonic irradiation (50 Hz) for homogenization and to form a biodegradable polymer nanocomposite sheet (5 × 5 cm 2 ). The amount of OMMT loading was from 0.5-5 mass%. These composites were subjected to degradation in minimal medium using Pseudomonas aeruginosa bacteria at controlled conditions, and the polymer is a major source of carbon. The degradation was confirmed using scanning electron microscopy, extracellular protein content change, biomass production, and % degradation with respect to time (up to 28 days) after incubation.

Circulatory levels of LH and FSH were measured in serum of male rats (28, 35, 42, 63, 70, 77, and 207 days of age) 7 days following sham operation, castration (C), prostatectomy (P), and castration + prostatectomy (C + P). In C + P rats that were 49, 63, 70, 77, and 207 days of age, the plasma FSH was significantly elevated as compared to the C group. Administration of aqueous prostatic extract restored the circulatory FSH level in C + P animals to that observed in C animals, whereas in C animals FSH levels were suppressed, indicating inhibinlike activity. In rats 49 and 77 days of age, circulatory LH levels were significantly suppressed in C + P animals as compared to the C group. Both castration and prostatectomy alone suppressed circulatory prolactin levels. Administration of prostatic extract to castrated animals restored the prolactin levels to that of the sham-operated control animals. Results of the present study suggest a role of the prostate in feedback regulation of FSH and prolactin.

Insect-growth regulators (IGRs) have been receiving foremost attention as potential means of selective insect control. Benzoyl phenyl urea (BPU) is a well-known IGR having chitin synthesis inhibitor activity. Mimics of BPU have been synthesized by suitable derivatization of a naturally occurring monoterpenoid, thymol (2-isopropyl-5-methyl phenol) to form a = series of substituted benzoyl thymyl thioureas (BTTUs) [IVa-f] and benzoyl thymyl ureas (BTUs) [Va-f]. The synthesized compounds have been characterized by (1)H and (13)C NMR, LC-MS and elemental analysis. These derivatives have been screened for their effect on total haemocyte count of Dysdercus koenigii. It has been observed that the introduction of substituted benzoyl thiourea and urea linkage into a thymol ring via an amino group results in higher activity than the parent compound thymol and a comparable pattern of results with the standard insect-growth regulators, Penfluron. Urea [Va-f] compounds exhibited greater effect on Total Haemocyte Count (THC) than thiourea [IVa-f]. Fluoro substitution enhanced the effect on THC more than chloro substituted compounds, while ortho-substitution resulted in a better effect than para-substitution. The results described in this paper are promising and provide new array of synthetic chemicals that may be utilized as insect growth regulators.

The half-life and metabolic clearance rate of human seminal plasma inhibin after injection into male rats was studied. Labeled inhibin was injected i.v. into 27-day-old rats (10 ng, 3.5 X i0 cpm)and 75-day-old rats (15 ng, 5.5 X i0 cpm). In both age groups, rats were killed at intervals between

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