Explore the vast range of titles available.

According to the World Health Organization (WHO), oxidative stress (OS) is a significant contributor to male infertility. Seminal OS can be measured by a number of assays, all of which are either costly or time sensitive and/or require large semen volume and complex instrumentation. One less expensive alternative is to quantify the oxidation-reduction potential (ORP) with the MiOXSYS. In this international multi-center study, we assessed whether ORP levels measured by the MiOXSYS could distinguish semen samples that fall within the 2010 WHO normal reference values from those that do not. Semen samples were collected from 2092 patients in 9 countries; ORP was normalized to sperm concentration (mV/10 sperm/ml). Only those samples with a concentration >1 × 10 sperm ml were included. The results showed that 199 samples fell within the WHO normal reference range while the remaining 1893 samples did not meet one or more of the criteria. ORP was negatively correlated with all semen parameters (P < 0.01) except volume. The area under the curve for ORP was 0.765. The ORP cut-off value (1.34 mV/10 sperm/ml) was able to differentiate specimens with abnormal semen parameters with 98.1% sensitivity, 40.6% specificity, 94.7% positive predictive value (PPV) and 66.6% negative predictive value (NPV). When used as an adjunct to traditional semen analysis, ORP levels may help identify altered functional status of spermatozoa caused by OS in cases of idiopathic male infertility and in male partners of couples suffering recurrent pregnancy loss, and thereby directing these men to relevant medical therapies and lifestyle modifications.

The powerful eruption of Hunga volcano (15‐January‐2022) excavated ∼6.3 km3 of pre‐existing material, leaving behind an 855 m deep crater. The scientific and humanitarian response to this event was challenging due to the remote location, safety concerns, and COVID‐19 pandemic restrictions. To investigate the status of ongoing eruptive/hydrothermal activity, this study used, for the first time, an un‐crewed surface vessel operated remotely from >16,000 km away to make direct water column measurements within the crater and map its structure in detail. Intense turbidity and oxidation‐reduction potential (ORP) anomalies located ongoing activity at sites on the steep inside crater slopes near both remaining islands. Mid‐water acoustic reflectors indicated ongoing degassing, and positive ORP anomalies suggested gas composition was dominated by CO2. At least 75% of the crater rim is shallower than 100 m, so any exchange with the surrounding ocean is limited by the depths of breaches in the rim (185 m between the islands and 290 m on the ENE side). This post‐eruption bathymetry results in accumulation of emission products within the deep crater. There were no indications of the ongoing activity visible at the ocean surface, which highlights the limitations and inherent biases associated with relying on discolored surface water and/or atmospheric disturbances to determine eruption start/end dates at submarine volcanoes. This study demonstrates the value and need to add repeat hydrothermal plume and bathymetric surveys to our toolbox for monitoring submarine volcanoes, and the potential for un‐crewed, remotely operated vessels to contribute significantly to these efforts. Plain Language Summary The powerful eruption of Hunga volcano on 15‐January‐2022 sent a plume to space and generated unusual tsunamis. How the eruption impacted the submarine environment was more difficult to determine. We used a highly innovative, un‐crewed vessel equipped with instruments to directly measure characteristics of the water within the 850 m deep crater excavated during the eruption and map the crater's shape in detail. These measurements showed there was ongoing hydrothermal/volcanic activity and CO2 degassing within the crater 7 months after the eruption. The deepest parts of the crater are isolated from the surrounding ocean, so products of this activity become trapped within the crater. While the most powerful eruptions are rare, they can be quite hazardous. The results from this study emphasize the importance of monitoring submarine volcanoes long after signs of eruptions are no longer visible at the ocean surface or atmosphere. Operation of the un‐crewed vessel >16,000 km from the study site was a major technological achievement and the first time that scientists could monitor operations in real time from anywhere around the globe. The success of this mission demonstrated the potential of this innovative technology to contribute to broader applications in ocean exploration, monitoring, and event response. Key Points Hydrothermal/volcanic activity and CO2 degassing continued at Hunga volcano 7 months after the explosive 15 January 2022 eruption Turbidity and CO2 are accumulating within the deep crater, which is isolated from the surrounding ocean deeper than ∼200 m First use of a novel un‐crewed vessel to conduct over‐the‐horizon bathymetric and water column surveys operated >16,000 km from the study site

Inadequate monitoring of the generator internal cooling water (GICW) system is one of the root causes for the system failure in nuclear, thermal and hydraulic power plants. The feasibility of using the oxidation-reduction potential (ORP) of GICW to better monitor the system statuses, GICW slight-alkalization and typical system abnormalities were evaluated on our dynamic simulation test device. During the process of GICW slight-alkalization, the ORP decreases linearly as the pH value increases with high correlation R2 of 0.9996, which is far more sensitive than the open-circuit potential (OCP) proposed in previous studies. This indication of sensitivity is attributed to the chemical inertness of the electrode in the GICW, thus ensuring its stable surface characteristic. Meanwhile, the two most common system abnormalities, CO2 leakage and DO decrease, were simulated. The results demonstrate that the ORP can keenly diagnose these two abnormalities, from their occurrences to their handling. Further, a more comprehensive specification of GICW oxidation property characterized as the ORP was obtained for guiding the field operation. In conclusion, it is feasible to use the ORP to better monitor GICW system statuses. This study proposes a promising parameter that can be used to improve current inadequate GICW system monitoring.

Aims: We tested two mechanisms of adaptation to extreme hydrological stresses (flooding and drought) of species making up a tropical wetland plant community by measuring leaf gas exchange and water potential. We hypothesized that anoxic conditions that occur during flooding will decrease leaf gas exchange when compared to the dry season, and that 'super-dominant' species will have a distinctive physiological advantage when compared to other plants within the community. Location: Northern Pantanal wetland, Private Natural Heritage Reserve of the Brazilian Social Service of Commerce (RPPN-SESC Pantanal), Mato Grosso, Brazil. Methods: Two periods representing typical extreme hydrological conditions in the Pantanal wetland were selected based on historical soil and meteorological measurements: (1) a drought period when plants experience stress due to soil moisture deficits during a dry season that persists for several months (May to Sept), and (2) a flooding period when oxidation-reduction potential is negative for 30 d or more (Mar or Apr), indicating anoxic stress. Measurements of gas exchange and leaf water potential were made on seven species in drought and flood stress conditions. The seven species represent the majority of the plant community. Results: As a whole, the plant community showed significantly lower potential net photosynthesis (PN) during flooding when soil oxidation-reduction potential reached close to — 900 mV when compared to the dry season, but the magnitude of the decline in PN was species specific. Not all super-dominant species showed higher PN compared to non-dominant species, but they did demonstrate higher stomatal conductance and transpiration leading to lower water use efficiency. The combination of higher PN despite low soil water content suggests that the plant community had access to deep water resources. This access was also confirmed by the midday leaf water potential, which was similar for the flood and dry seasons. Conclusions: Results suggest that the plant community may have high physiological performance under a wide range of soil oxidation-reduction potentials. Higher PN rates of super-dominant species indicate a physiological advantage of these species in the different hydrological conditions.

Oxidative stress (OS) is detrimental to sperm functions, and the oxidation reduction potential (ORP) is a good measure of OS as it considers the balance between oxidants and reductants. Total motile sperm count (TMSC) is viewed as the single most important semen analysis parameter that can predict male infertility severity, and its correlation with ORP has never been undertaken. The objectives of this study were to assess the correlation between ORP and TMSC, to identify the ORP cutoff value based on the TMSC result, and to compare this cutoff value with previously reported ORP cutoff values in literature. One thousand one hundred and sixty-eight infertile patients and 100 fertile controls were enrolled. Demographic and semen data of the participants were retrieved and analyzed. Wilcoxon's rank-sum test compared variables between infertile men and fertile controls; Spearman's correlation assessed the static ORP (sORP)-TMSC relationship for the whole sample and among each group individually. Using a 20×106TMSC threshold, receiver operator characteristic (ROC) analysis determined the sORP cutoff associated with the highest predictive values. TMSC was significantly negatively correlated with sORP across all participants (r = 0.86, P < 0.001), among infertile patients (r = 0.729, P < 0.001), and among fertile controls (r = 0.53, P < 0.001). A 20-million TMSC threshold determined an sORP cutoff value of 2.34 mV/106sperm/ml to be associated with 82.9% sensitivity, 82.8% specificity, 91.5% positive predictive value (PPV), 68.5% negative predictive value (NPV), and 82.9% overall accuracy. Compared with previously reported cutoff values in searched literature, the 2.34 mV/106sperm/ml cutoff value identified in our study yielded the highest overall diagnostic accuracy in the evaluation of infertile men.

Oxidation-reduction (redox) reactions can affect drinking water treatment and distribution in significant ways. Measurements of oxidation-reduction potential (ORP) in water reflect the tendency of major constituents in the water to accept or lose electrons. Although ORP measurements are valuable and can provide useful information toward protecting public health, they are not widely undertaken by the drinking water community for a variety of reasons. The objective of this research was to determine the effect of five oxidants commonly used in drinking water treatment as well as the effect of pH on measured ORP. Results showed that the ORP of each oxidant system increased with increasing oxidant concentration to a maximum. The ORP also decreased with increasing pH. Water treated with chlorine and chlorine dioxide had the greatest ORP followed by water containing monochloramine and permanganate and water containing only oxygen. Duplicate ORP measurements revealed some inconsistencies with redox electrode measurements.

The aim of the present study was to examine the changes occuring in the redox status in male basketball players at the beginning and end of a highly competitive season. For this purpose, the redox status of 14 professional athletes of a European basketball club was examined at 2 different time points, at the beginning (phase 1) and at the end of the season (phase 2). The redox status was assessed in blood using conventional oxidative stress markers, such as thiobarbituric acid reactive substances (TBARS), protein carbonyls (CARB) and the total antioxidant capacity (TAC) in plasma, as well as glutathione (GSH) levels and catalase (CAT) activity in erythrocytes. Moreover, a new static oxidation-reduction potential marker (sORP) was assessed in plasma. Our results revealed that sORP was significantly increased by 9.6% and GSH levels were significantly decreased by 35.0% at phase 2 compared to phase 1, indicating the induction of oxidative stress due to excessive exercise. Moreover, TAC was significantly increased by 12.9% at phase 2 compared to phase 1, indicating the activation of adaptive responses for counteracting oxidative stress. The CARB and TBARS levels were not significantly altered between the 2 phases, although there was a significant correlation (r=0.798) between the sORP and CARB levels. Furthermore, the variations in these markers between athletes were examined. We found that 3 markers exhibited a similar response between athletes, that is, sORP was increased in all 14 athletes, TAC was increased in 13 and the GSH levels were decreased in 14. However, the other 3 markers (i.e., TBARS, CARB and CAT) exhibited marked variations between the athletes, suggesting that the optimal approach with which to counteract (e.g., antioxidant supplementation) the observed increase in oxidative stress is the individualized examination of the redox status of athletes using a series of markers. This would allow the identification of athletes affected by severe oxidative stress and inflammation, and would thus indicate when necessary intervention measures are required to improve their health and performance.

Cold plasma and ozone sanitation of irrigation solutions can oxidize both microbes and non-target micronutrients because their high oxidation-reduction potential (ORP) is a non-selective mode of action. The objective of this study was to evaluate the effects of cold plasma and ozone treatment on oxidation of iron and manganese in nutrient solutions containing one of four iron chelates (iron-ethylenediaminetetraacetic acid (Fe-EDTA), iron-diethylenetriaminepentaacetic acid (Fe-DTPA), iron-ethylenediamine-N,N′-bis(2-hydroxyphenylacetic acid) (Fe-EDDHA), and hydroxybenzyl ethylenediamine (Fe-HBED)). Nutrient solutions were recirculated through the cold plasma or ozone system until the ORP reached 700 mV. The concentrations of total dissolved iron, manganese, and chelated iron were measured before and after passing through the treatment systems. Both cold plasma and ozone oxidized chelates and decreased the solubility of iron and manganese. Cold plasma and ozone had similar effects on micronutrients, pH, electrical conductivity, and dissolved oxygen at a standardized target ORP of 700 mV. Fe-EDTA was the most resistant chelate to oxidation. With Fe-EDTA, ORP increased more quickly, and the concentration of chelated Fe decreased less with the increasing ORP over time compared with Fe-DTPA, Fe-EDDHA, and Fe-HBED. The concentration of chelated Fe decreased by up to 80% for EDDHA at 700 mV compared with a 20% decrease for EDTA. The concentration of Mn decreased by up to 85% at 700 mV. The design of water treatment with cold plasma or ozone therefore requires consideration of secondary effects on micronutrients. The treatment dosage, flow rate, and nutrient solution at a particular grower operation are likely to affect the quantity of micronutrient fertilizer that needs to be supplemented following treatment. Use of Fe-EDTA is one strategy to reduce the loss of iron and increase residual ORP that is available for sanitation.

Results from the Mars Phoenix mission Wet Chemistry Laboratory (WCL) are used to determine the oxidation‐reduction potential (Eh) of the Phoenix WCL Rosy Red sample soil solution. The measured Eh of the Rosy Red sample in the WCL aqueous test solution was 253 ± 6 mV at a pH of 7.7 ± 0.1. Measured solution Eh changes correspond to changes in solution H+ activity, which is controlled mainly by changes in headspace PCO2 and solution CO32−, HCO3−, and CO2 concentrations. If measured at a PCO2 of 8 mbar in water, rather than in WCL test solution, the Eh of the Rosy Red soil solution would be ∼300 mV. The results of laboratory experiments using analog salt mixtures are compatible with the possible presence of low levels (ppm) of metal peroxides or other oxidants and indicate that levels of readily soluble ferrous iron in the soil are below 1 ppm. Key Points The measured Eh of an aqueous Mars soil solution was 253 mV The results are compatible the presence of low levels (ppm) of oxidants The results indicate that soluble ferrous iron in the soil is below 1 ppm

Treated water from the water treatment plant (WTP) gets to the final consumers through complex water distribution systems (WDSs). The study assessed the levels of physico-chemical and microbial qualities of treated water moving through WDSs of different pipe materials and properties of residue deposits on the shallow inner walls of investigated pipes as means of evaluating water and residue qualities. The investigated WDSs include galvanized iron pipes (GIPs), asbestos cement pipes (ACPs) and polyvinylchloride pipes (PVCPs). Assessment of water and residues samples was carried out according to APHA and ASTM standard procedures. Pearson correlation and analysis of variance (ANOVA) were used to evaluate the relationship between two continuous parameters and spatial variability among the investigated pipes, respectively. Results showed that the physico-chemical and microbial instability of water samples were more pronounced in GIPs, followed by ACPs and least in PVCPs. However, changing water quality indicators were found to be significant in water from GIP and ACP of smaller diameters. Most of the drinking water quality parameters in treated water at WTP lie within the standard permissible limits for drinking purpose. However, the water quality deteriorated bacteriologically, from the WTP to the WDSs. The mean pH ranged from 6.9 to 7.5; temperature fluctuated from 30 to 31 °C; EC varied from 147.3 to 248.8 μS/cm while total suspended solids (TSS) varied from 40.6 to 503.8 mg/L. Chloride ions ranged from 102.4 to 355.2 mg/L with its mean values in GIPs and 75 mm diameter ACP above the safe limit for potable water. The redox potential values of < 400 mV in all analyzed water samples indicate enhancing environment for biofilm growth. The results of residue properties further corroborate the level of quality indicators in collected water through the investigated pipes. The overall results indicate that pipe material, pipe diameter, and anthropogenic sources contribute to alteration in water quality of conveyed treated water. The Pearson correlation result shows that most of the analyzed water parameters except resistivity and dissolved oxygen (DO) positively correlate pair-wise either at 1% or 5% levels. The ANOVA indicates that pH and HCO 3 - concentrations in water from GIPs were significantly higher at 5% level than those found in water from PVCPs, ACPs and WTP. The oxidation-reduction potential (ORP) of treated water was significantly lower than that of water samples from all the investigated pipes at α  = 0.05. However, the ORP values in residues did not vary significantly among the investigated pipes at 5% level. The study recommends reservoir cleaning program, suitable modification of treatment procedures, and constant check for leakages in the main distribution systems and service pipes among others as means of maintaining the stability of water quality status of treated water through the WDSs.