A Comparative Analysis of Friction and Energy Losses in Hydrogen and CNG Fueled Engines: Implications on the Top Compression Ring Design Using Steel, Cast Iron, and Silicon Nitride Materials.

Optimizing the design of the top compression ring holds immense importance in reducing friction across both traditional Internal Combustion (IC) engines and hybrid power systems. This study investigates the impact of alternative fuels, specifically hydrogen and CNG, on the behavior of top piston rings within internal combustion (IC) engines. The goal of this approach is to understand the complex interplay between blow-by, fuel type, material behavior, and their effects on ring friction, energy losses, and resulting ring strength.

Risk of chemotherapy-induced amenorrhea in patients with breast cancer: a systematic review and meta-analysis.

Background: The aim of the study was to calculate the rate of chemotherapy-induced amenorrhea (CIA) after treatment with different adjuvant therapies in patients with breast cancer and to evaluate the risk factors for CIA based on the quality of evidence.

Patient And Methods: A search of PubMed and ISI Web of Science was performed. All published trials with female breast cancer patients who received adjuvant chemotherapy and presented data on the rate of CIA were considered eligible.

Double versus single homologous intrauterine insemination for male factor infertility: a systematic review and meta-analysis.

Male factor infertility affects 30%-50% of infertile couples worldwide, and there is an increasing interest in the optimal management of these patients. In studies comparing double and single intrauterine insemination (IUI), a trend towards higher pregnancy rates in couples with male factor infertility was observed. Therefore, we set out to perform a meta-analysis to examine the superiority of double versus single IUI with the male partner's sperm in couples with male factor infertility.

The progesterone positive feedback effect in women after ovariectomy.

Various ovarian substances regulate the secretion of gonadotrophins during the menstrual cycle, but there are still several unclarified issues. The aim of this study was to investigate the positive feedback effect of progesterone during the immediate period following ovariectomy. Experiments were performed in 12 normally cycling women (aged 39-49 years).

Misoprostol prior to hysteroscopy in premenopausal and post-menopausal women. A systematic review and meta-analysis.

Background: Although several randomized controlled trials (RCTs) have examined the effect of misoprostol prior to hysteroscopy for cervical dilatation, no solid conclusion has been reached. We therefore set out to perform a meta-analysis of RCTs.

Methods: We searched MEDLINE, the ISI Web of Science and the Cochrane Library to identify RCTs comparing misoprostol versus placebo or control prior to hysteroscopy.