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In this paper, computational fluid dynamic (CFD) analysis and experiments have been carried out to study the effect of nozzle pressure ratio, i.e. the ratio of inlet pressure to atmospheric pressure, and the pitch circle diameter of the control jets to regulate the base pressure. The variables considered for the analysis as well as the experiments are the nozzle pressure ratio (NPR), the Mach number (M) and the pitch circle diameter (PCD) of the control jets. The area ratio considered for the study is kept constant at 4.84 while the length to diameter (L/D) ratio of an enlarged duct is set constant at 5. The inertia parameter considered for the study is Mach number. The Mach numbers considered for study are 1.5, 2.0, and 2.5. The nozzle pressure ratio considered for study are 2, 5 and 8. Three different pitch circle diameters of control jets considered for study are 13.1 mm, 16.2 mm and 19.3 mm. From the numerical simulations and the results of the experimental tests, it is found that the control jets are very beneficial to increase the base pressure at higher NPR when the jets issuing from the nozzles are under-expanded. The control jets were able to increase the base pressure value from 160% to 400% at nozzle pressure ratio 8. It is concluded that the parameter D3 is the most effective pitch circle diameter of the control jets to increase the base pressure. [ABSTRACT FROM AUTHOR]

Since its Fast-Track approval by the Federal Drug Administration, the human papillomavirus (HPV) vaccine has been marked by controversies. Unconfirmed reports of adverse events in both Japan and Denmark led to suspensions of national vaccination programs, which setback the fight against cervical cancer and associated mortality and morbidity. Despite follow-up studies of vaccine adverse reports, additional randomized control trials, and review reports from both the World Health Organization and the European Commission, there is still a great deal of hesitancy around the vaccine. While all three version of the HPV vaccine have been shown to be efficacious and safe, additional ethical dilemmas deserve to be considered as well., (© 2024 by The Korean Society of Infectious Diseases, Korean Society for Antimicrobial Therapy, The Korean Society for AIDS, and Korean Society of Pediatric Infectious Diseases.)

The present work was designed to study the effect of Azadirachta indica (Neem) powder on rat testis using the electron microscope. Male albino rats received 100 mg each A. indica leaf powder orally (by gavage). On alternate days, a second group of rats received 0.125 mg testosterone dipropionate intramuscularly. A third group received both A. indica leaf powder by gavage and testosterone dipropionate intramuscularly. Suitable controls were maintained. After autopsy, ultrastructural analysis of the testis revealed that animals treated with testosterone dipropionate showed well-developed Sertoli cells and germ cells with well-developed cytoplasmic organelles. By contrast, in A. indica-treated rats, intracellular spaces and vacuolization were observed in Sertoli cells; whereas in Leydig cells, cytoplasmic inclusions appeared diminished, and the configuration of granular endoplasmic reticulum appeared as a single unbranched tubule. In late spermatids, defects were observed in the mitochondrial sheath. The ultrastructural changes seen in the A. indica-treated group provide a clue that A. indica leaves might affect spermatogenesis through antispermatogenic and antiandrogenic properties.

Oral administration of 20, 40, 60, mg of dry Azadirachta indica leaf powder for 24 days resulted in decrease in the weights of seminal vesicles and ventral prostate, reduction in epithelial height, nuclear diameter and the secretory material in the lumen. Biochemically, there was a decrease in total protein, acid phosphatase activities. Seminal vesicles and ventral prostate being androgen dependent, the regressive changes histologically as well as biochemically, suggests the antiandrogenic property of the neem leaves.

Histological and biochemical changes in the testis of rats treated with the leaf powder of A. indica are reported. The pattern of recovery is also studied at 8, 16 and 24 day after withdrawal of the treatment. In the treated rats, a general reduction in the diameters of seminiferous tubule, nuclei of the germinal elements and a mass atrophy of the spermatogenic elements has been observed. The Leydig cells are found to be atrophic. Biochemically, a decrease in the protein content and the activity of acid phosphatase and an increase in the total free sugar, glycogen, cholesterol contents and the activities of alkaline phosphatase and lactate dehydrogenase have been observed. A gradual recovery is observed in both the histological and biochemical parameters after 8.16 and 24 day of cessation of the treatment. The result suggest a possible reversible antiandrogenic property of the leaves of A. indica in male albino rats.

The histological and biochemical changes in the caput and cauda epididymis of albino rat treated with 20, 40 and 60 mg dry powder of the leaves of A. indica per day for 24 days are reported. In the treated rats, the height of the epithelium and the diameter of the nucleus in both the regions were reduced. The lumen of the caput was packed with lymphocytes. Biochemically, a decrease in the protein content and acid phosphatase activity and an increase in the alkaline phosphatase and lactate dehydrogenase activities were observed in both the regions. The effect was dose dependent. Further, serum testosterone concentration in the higher dose treated animals decreased significantly. The results suggest a possible antiandrogenic property of the leaves of A. indica.