The Far-Infrared Spectrum of Methoxymethanol (CH-O-CHOH): A Theoretical Study.

Methoxymethanol (CHOCHOH), an oxygenated volatile organic compound of low stability detected in the interstellar medium, represents an example of nonrigid organic molecules showing various interacting and inseparable large-amplitude motions. The species discloses a relevant coupling among torsional modes, strong enough to prevent complete assignments using effective Hamiltonians of reduced dimensionality. Theoretical models for rotational spectroscopy can improve if they treat three vibrational coordinates together.

Theoretical structural and spectroscopic characterization of peroxyacetic acid (CH-CO-OOH): study of the far infrared region.

Peroxyacetic acid, a non-rigid oxygenated organic molecule which acts in the atmosphere as a reservoir of HO and RO radicals, is studied using highly correlated methods with the aim of its spectroscopic characterization in the gas phase. The study focuses on the far infrared region providing reliable rovibrational parameters such as energy levels and splittings. The molecule presents three conformers that inter-convert by internal rotation, drawing a potential energy surface of 12 minima.

Relationship between sperm aneuploidy, sperm DNA integrity, chromatin packaging, traditional semen parameters, and recurrent pregnancy loss.

Objective: To study the possible relationship between sperm aneuploidy, sperm DNA integrity, chromatin packaging, traditional semen parameters, and recurrent pregnancy loss (RPL).

Design: Descriptive study.

Setting: University-affiliated tertiary teaching.

Meiotic segregation and sperm DNA fragmentation in Tunisian men with dysplasia of the fibrous sheath (DFS) associated with head abnormalities.

Purpose: Dysplasia of the Fibrous Sheath (DFS) is a primitive flagellar pathology for which a broad spectrum of ultrastructural flagellar abnormalities has been described responsible for a severe to total asthenozoospermia. To this phenotype other morphological abnormalities including cephalic and abnormalities in nuclear structure can be associated that could compromise embryonic development in case of use of Assisted Reproductive Technology (ART). The aim of this study was to evaluate the level of DNA fragmentation and aneuploidy rate in ejaculated spermatozoa of Tunisian men presented with DFS sperm defect associated to high percentage of head abnormalities and to compare the results with those from fertile men.

DNA fragmentation status in patients with necrozoospermia.

The aim of this study was to determine if a relationship exists between the levels of sperm DNA fragmentation and necrospermia in infertile men. Semen samples obtained from 70 men consulting for infertility evaluation were analyzed according to World Health Organization (WHO) guidelines. Patients were subdivided into three groups according to the percentage of necrotic spermatozoa: normozoospermia (<30%; n = 20), moderate necrozoospermia (50-80%; n = 30), and severe necrozoospermia (>80%; n = 20).