Male oxidative stress infertility (MOSI): proposed terminology and clinical practice guidelines for management of idiopathic male infertility

Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause

Male Oxidative Stress Infertility (MOSI):proposed terminology and clinical practice guidelines for management of idiopathic male infertility

Despite advances in the field of male reproductive health, idiopathic male infertility, in which a man has altered semen characteristics without an identifiable cause and there is no female factor infertility, remains a challenging condition to diagnose and manage. Increasing evidence suggests that oxidative stress (OS) plays an independent role in the etiology of male infertility, with 30% to 80% of infertile men having elevated seminal reactive oxygen species levels. OS can negatively affect fertility via a number of pathways, including interference with capacitation and possible damage to sperm membrane and DNA, which may impair the sperm's potential to fertilize an egg and develop into a healthy embryo. Adequate evaluation of male reproductive potential should therefore include an assessment of sperm OS. We propose the term Male Oxidative Stress Infertility, or MOSI, as a novel descriptor for infertile men with abnormal semen characteristics and OS, including many patients who were previously classified as having idiopathic male infertility. Oxidation-reduction potential (ORP) can be a useful clinical biomarker for the classification of MOSI, as it takes into account the levels of both oxidants and reductants (antioxidants). Current treatment protocols for OS, including the use of antioxidants, are not evidence-based and have the potential for complications and increased healthcare-related expenditures. Utilizing an easy, reproducible, and cost-effective test to measure ORP may provide a more targeted, reliable approach for administering antioxidant therapy while minimizing the risk of antioxidant overdose. With the increasing awareness and understanding of MOSI as a distinct male infertility diagnosis, future research endeavors can facilitate the development of evidence-based treatments that target its underlying cause

Heterogeneous photocatalytic degradation of methanol over uranyl-anchored nanoporous MCM-41 and MCM-48

The vapor-phase photoclegraclation of methanol to carbon dioxide was carried out over uranylanchored nanoporous MCM-41 and MCM-48 hosts (designated as UO22 divided by/MCM-41 UO22 divided by/MCM-48 48, respectively) under simulated light and ambient conditions. Preliminary results indicate that the photoactivity of the latter is considerably decreased as compared to the former due to the presence of a smaller fraction of photoactive uranyl (UO22+) ions in UO22 divided by/MCM-48

Sunlight-assisted photocatalytic oxidation of methane over uranyl-anchored MCM-41

Uranyl ions anchored within the mesopores of MCM-41 silicate host matrix served as highly efficient heterogeneous catalysts for sunlight-assisted room-temperature photooxidation of methane in the presence of air to selectively form carbon dioxide. The extent of conversion depended upon the methane content; lower the concentration, faster was the completion of reaction. It was also confirmed that no thermocatalytic reaction occurred below 200 degreesC in the absence of radiation, other test conditions remaining the same. These results are of relevance from the point of view of abatement of VOCs in the environment

Uranyl-anchored MCM-41 as a highly efficient photocatalyst for the complete oxidation of methanol under sunlight

A photocatalyst that may exhibit high activity for oxidation of volatile organic compounds (VOCs) under solar radiation would offer a practical and economic means for the cleaning of air under environmental conditions. We report here for the first time that the uranyl ions anchored within the mesopores of MCM-41 may serve as an efficient heterogeneous photocatalyst for the complete destruction of methanol in vapor phase, and in the presence of sunlight and air. The uranyl-anchored MCM-41 was found to be more efficient than a TiO(2) photocatalyst in terms of CH(3)OH-->CO(2) conversion rates. The reversible and active participation of uranyl groups in the studied photocatalytic reaction was ascertained with the help of in situ fluorescence and electron paramagnetic resonance techniques, whereas the radiation-induced transient species over catalyst surface were monitored using in situ FTIR spectroscopy. The detailed reaction mechanism and the role played by uranyl ions in the photooxidation of methanol over UO(2)(2+)/MCM are elucidated on the basis of these results. (C) 200

An in situ FT-IR study of photo-oxidation of alcohols over uranyl-anchored MCM-41: Possible reaction pathways

Photosensitive uranyl ions anchored onto MCM-41 mesoporous molecular sieves serve as remarkable photocatalysts in the degradation of alcohols, under ambient conditions of light, temperature, and air. The rates of conversion of alcohols to carbon dioxide was found to decrease in the order methanol > ethanol > 2-propanol > 1-propanol, with the difference in reactivity attributed to the stability of the carbon-centered radicals formed during photo-oxidation. Kinetics revealed that the photo-oxidation of alcohols followed a first-order reaction. A detailed in situ FT-IR analysis was used to identify the transient species formed during the photo-oxidation of ethanol and 2-propanof over uranyl-anchored photocatalyst. Acetic acid, ethyl acetate, and acetaldehyde were the intermediates obtained over UO22+/MCM-41 during photo-oxidation of ethanol, whereas acetate species, methyl acetate, and acetone were detected during photo-oxidation of 2-propanol. Based on the intenriediate species formed, their growth with respect to irradiation time, and their intensities, appropriate reaction mechanisms were proposed to corroborate our observations. (c) 2007 All fiahts reserved

Vapor-phase photocatalytic oxidation of volatile organic compounds over novel uranyl-anchored MCM-41 heterogeneous catalyst

In the present investigation, we exploited the visible region absorbance (lambda > 380 nm) of uranyl ions anchored onto mesoporous MCM-41 matrix for the vapor-phase photooxidation of volatile organic compounds (VOCs) such as benzene, toluene, cyclohexane, cyclohexene, and oxylene. In all cases, the only complete oxidation products, viz., carbon dioxide and water, were obtained. Further, the extent of conversion to carbon dioxide depended upon the nature of the organic compound. Under sunlight, the uranyl-anchored catalyst was found to be highly active for the degradation of a stable molecule like benzene, though longer irradiation times were needed for its complete conversion. This study signifies the potential applicability of the uranyl-anchored photocatalyst for applications related to air cleaning under ambient conditions of solar radiation and air

Uranyl-anchored MCM-41 as a highly efficient photocatalyst in the oxidative destruction of short chain linear alkanes: An in situ FTIR study

Uranyl ions anchored in the mesopores of MCM-41 molecular sieve were found to be a highly efficient heterogeneous photocatalyst in the complete degradation of short chain linear alkanes such as methane, ethane, propane, and butane, carried out under ambient conditions of light irradiation. In addition to the formation of carbon dioxide and water, a negligible amount of methane was detected during the photooxidation of ethane, propane, and butane. Further, small amounts of ethane were also obtained during photooxidation of butane, suggesting quenching of *UO22+ by a C-C bond cleavage, in addition to a hydrogen atom abstraction. An C, in situ Fourier transform IR spectroscopy analysis was employed in order to monitor the photooxidation of methane and ethane over *UO22+/MCM-41, where formic acid, formaldehyde, and formate species were the transient species identified from methane, and acetic acid, acetaldehyde, and acetate species were the intermediates obtained from ethane. Appropriate reaction pathways were proposed based on the formation of these species (C-H cleavage) and also from the negligible quantitites of methane and ethane obtained during photooxidation of higher alkanes (C-C cleavage)

X-ray photoelectron spectroscopic study of the oxide film on an aluminum-tin alloy in 3.5% sodium chloride solution

Oxide films on Al and an Al-Sn alloy were analyzed by x-ray photoelectron spectroscopy (XPS) after immersion in 3.5% sodium chloride (NaCl) solution. Results showed Sn exhibited both Sn2+ and Sn4+ oxidation states in the oxide film It was proposed that incorporation of these cations in the film would result in generation of more anionic and cationic vacancies in aluminum oxide (Al2O3), leading to active dissolution of Al