Total Content Research Articles

Effect of particle size on liver MRI relaxometry: Monte Carlo simulation and phantom studies.

To investigate the effect of particle size on liver by Monte Carlo simulation and phantom studies at both 1.5 T and 3.0 T. Two kinds of particles (i.e., iron sphere and fat droplet) with varying sizes were considered separately in simulation and phantom studies. MRI signals were synthesized and analyzed for predicting , based on simulations by incorporating virtual liver model, particle distribution, magnetic field generation, and proton movement into phase accrual. In the phantom study, iron-water and fat-water phantoms were constructed, and each phantom contained 15 separate vials with combinations of five particle concentrations and three particle sizes. measurements in the phantom were made at both 1.5 T and 3.0 T. Finally, differences in predictions or measurements were evaluated across varying particle sizes. In the simulation study, strong linear and positively correlated relationships were observed between predictions and particle concentrations across varying particle sizes and magnetic field strengths ( ). The relationships were affected by iron sphere size ( ), where smaller iron sphere size yielded higher predicted , whereas fat droplet size had no effect on predictions ( ) for constant total fat concentration. Similarly, the phantom study showed that measurements were relatively sensitive to iron sphere size ( ) unlike fat droplet size ( ). Liver is affected by iron sphere size, but is relatively unaffected by fat droplet size. These findings may lead to an improved understanding of the underlying mechanisms of relaxometry in vivo, and enable improved quantitative MRI phantom design.

Efficient Removal of Water Soluble Fraction of Diesel Oil by Biochar Sorption Supported by Microbiological Degradation

The contamination of the water bodies by diesel oil (DO) and its water-soluble fraction (WSF) represents one of the most challenging tasks in the management of polluted water streams. This paper contains data related to the synthesis and characteristics of the plum stone biochar material (PmS-B), which was made from waste plum stones (PmS), along with its possible application in the sorption of the WSF of DO from contaminated water. Techniques applied in sample characterisation and comparisons were: Elemental Organic Analysis (EOA), Scanning Electron Microscopy−Energy Dispersive X-ray Spectroscopy (SEM-EDX), Fourier Transform Infrared Spectroscopy (FTIR), pH (pHsus) and point of zero charge (pHpzc). In order to increase the overall efficiency of the removal process, sorption and bioremediation were subsequently combined. Firstly, PmS-B was used as a sorbent of WSF, and then the remaining solution was additionally treated with a specific consortium of microorganisms. After the first treatment phase, the initial concentration of diesel WSF was reduced by more than 90%, where most of the aromatic components of DO were removed by sorption. The sorption equilibrium results were best fitted by the Sips isotherm model, where the maximum sorption capacity was found to be 40.72 mg/g. The rest of the hydrocarbon components that remained in the solution were further subjected to the biodegradation process by a consortium of microorganisms. Microbial degradation lasted 19 days and reduced the total diesel WSF concentration to 0.46 mg/L. In order to confirm the non-toxicity of the water sample after this two-stage treatment, eco-toxicity tests based on a microbial biosensor (Aliivibrio fischeri) were applied, confirming the high efficiency of the proposed method.

Pomegranate (Punica granatum L.) growth and biochemical alterations in response to meloidogyne incognita infection, minerals, and nano-fertilizers

The effects of four inoculum levels (500, 1,000, 2,000, or 4,000 second-stage juveniles (J2) per plant) of the root-knot nematode, Meloidogyne incognita, on two pomegranate cultivars (‘Manfalouty’ and ‘Wonderful’) were investigated under greenhouse conditions in response to plant inorganic and organic chemical concentrations. Furthermore, the effects of six commercial chemical fertilizers (inorganic fertilizers and nano-fertilizers) on plant growth and nematode reproduction were also studied. Both cultivars recorded the highest gall formation, embedded stages, and final nematode population at the inoculum dosage of 2,000 J2/plant. The highest reproductive rate was achieved with 500 J2/plant, while the lowest rate was observed with 4,000 J2/plant on both cultivars. ‘Wonderful’, at all M. incognita inoculum levels, was more sensitive to nematode infestation than ‘Manfalouty’. ‘Wonderful’ showed a greater reduction in fresh and dry plant weights than ‘Manfalouty’ at 2,000 and 4,000 J2/plant. In both cultivars, the concentrations of N, P, and K decreased with increasing nematode inoculum levels. This decline was more pronounced in ‘Manfalouty’ than in ‘Wonderful’. The nano-fertilizers, Hyper Feed®, and Hyper Feed Solo® reduced all nematode parameters but only in ‘Wonderful’. Treatment with Hyper Feed® resulted in the highest percentage increases in all plant growth parameters in ‘Wonderful’. Total carbohydrate concentration was increased in ‘Manfalouty’ treated with the nano-fertilizers, especially with Hyper Feed®. Also, concentrations of total phenols and tannins increased in ‘Wonderful’ when treated with either nano-fertilizer. Generally, both nano-fertilizers showed an increase in plant N levels. We recommend using nano-fertilizers in integrated pest management (IPM) programs on pomegranate where they improved plant growth parameters and reduced nematode multiplication parameters more markedly than inorganic fertilizers.

Pollution characteristics and risk assessment of organophosphate esters (OPEs) in typical industrial parks in Southwest China.

As alternative substances of PBDEs, organophosphate esters (OPEs), an emerging organic pollutant, were increasingly produced and used in many kinds of industries and consumer products. However, OPEs also have various adverse toxic effects. Information on the pollution levels and exposure to OPEs in related industries is still limited. This study presented data on OPE contamination in the soil, leaf, and river water samples from seven typical industrial parks in Southwest China. Total concentration of seven OPEs (Σ7OPE) including tri-n-butyl phosphate (TnBP), tris-(2-ethylhexyl) phosphate (TEHP), tris-(2-butoxyethyl) phosphate (TBEP), tris-(2-carboxyethyl) phosphine (TCEP), triphenyl phosphate (TPhP), tris-(1,3-dichloro-2-propyl) ester (TDCPP), and tris-(chlorisopropyl) phosphate (TCPP) in the soil samples (36.2 ~ 219.7 ng/g) and the surrounding river water samples (118.9 ~ 287.7 ng/L) were mostly lower than those in other studies, while the Σ7OPE level in the leaves (2053.3 ~ 8152.7 ng/g) was relatively high. There were significant differences in the concentration and distribution of OPEs in the surrounding environment of different industrial parks. TDCPP, TnBP, and TCPP could be used as the characteristic compound in soil samples from auto industrial park, river samples from shoe making industrial park, and leaf samples from logistics park, respectively. The parameter m (the content ratio of chlorinated OPEs to alkyl OPEs) was suggested to distinguish the types of industrial park preliminary. When m ≥ 1, it mainly refers to heavy industries sources such as automobiles, electronics, and machinery, etc. When m<1, it mainly for the light industrial sources such as textile industry, transportation services, and resources processing, etc. For logistics park, furniture park and Wuhou comprehensive industrial park, the volatilization of materials was the main sources of OPEs in the surrounding environment, while more effort was required to strengthen the pollution control and management of the waste water and soil in the pharmacy industrial park, shoe making industrial park and auto industrial park. Risk assessment showed that there was a negligible non-cancer and carcinogenic risk in the soil, while high attention should be paid to the non-cancer risk for children.

Effects of Pesticides Use on Pesticides Residues and Its Environmental Risk Assessment in Xingkai Lake（China）

Xingkai Lake, located in Heilongjiang Province, is an important fishery and agricultural base and is seriously polluted by agricultural non-point sources. To clarify the residual status of many pesticides in the surface water of Xingkai Lake, 27 types of pesticides, herbicides, and their degradation products were analyzed in rice paddy, drainage, and surface water around Xingkai Lake (China) during the rice heading and maturity periods. The results showed that all 27 types of pesticides, herbicides, and their degradation products were detected during the rice heading period, and the total concentration ranged from 247.97 to 6 094.49 ng·L-1. Additionally, 25 species were detected during the rice maturity period, and the total concentration ranged from 485.36 to 796.23 ng·L-1. In comparison, more pesticides, herbicides, and derived degradation products were detected during the heading period, and their total concentration was higher as well. During the rice heading period, atrazine, simetryn, and paclobutrazol were the main detected pesticides, atrazine and isoprothiolane were the main pesticides detected during the maturity period. The distribution characteristics of pesticides and herbicides in the surface water around Xingkai Lake (China) was similar to that in drainage, so they were probably imported from the drainage and rice paddy. The average risk quotient (RQ) values of atrazine, simetryn, prometryn, butachlor, isoprothiolane, and oxadiazon were higher than 0.1 in drainage and Xingkai Lake (China), which showed a potential risk to aquatic organisms.

Variations of source-specific risks for inhalable particles-bound PAHs during long-term air pollution controls in a Chinese megacity: Impact of gas/particle partitioning

Gas/particle (G/P) partitioning is a determining factor that drives the behavior of polycyclic aromatic hydrocarbons (PAHs) in the atmosphere. To comprehend the variations and impacts of PAHs G/P partitioning on inhalation risks from different sources, atmospheric PAHs in Chengdu were studied from January 2009 to January 2021. Chengdu's air quality demonstrated improvement, with a noticeable decline in PM10 (from 238 to 103 μg m−3), PM10-bound PAHs mass concentrations (from 0.08 to 0.01 μg m−3), as well as PAHs inhalation non-cancer (from 63.5 to 7.1) and cancer risks (from 6.2 × 10−5 to 7.7 × 10−6). Decreasing trends were also observed in the concentrations of organic carbon (OC) and the values of absorptive G/P partitioning coefficient (Kp, OM) from 2009 to 2020, indicating a slight decrease in the PM absorptive capacity. A positive matrix factorization (PMF) model utilized three distinct datasets: PMFpp (particle-phase PAHs only), PMFtot (total PAHs concentrations), and PMFpp/gas (particle-phase in parallel with gas-phase PAHs). PMFpp and PMFpp/gas provide reasonable source apportionment and source-specific risk results. However, daily variations in source contributions of PMFtot were found to be unreasonable. PMFpp/gas and PMFtot could identify a source of low molecular weight PAHs (LPAHs) related to temperature, and a significantly positive correlation between LPAHs and temperature was discovered. Gas/particle partitioning of PAHs showed a notable impact on source-specific risks associated with coal and biomass combustion (CC&BC). The findings contribute to our understanding of the variation in PAHs G/P partitioning and the PM absorptive capacity resulting from effective air pollution control in China. Additionally, they offer prerequisite information for incorporating semi-volatile organic compounds in source apportionment and source-specific risk assessment.

Longitudinal in vivo cationic contrast-enhanced computed tomography classifies equine articular cartilage injury and repair.

Cationic contrast-enhanced computed tomography (CECT) capitalizes on increased contrast agent affinity to the charged proteoglycans in articular cartilage matrix to provide quantitative assessment of proteoglycan content with enhanced images. While high resolution microCT has demonstrated success, we investigate cationic CECT use in longitudinal in vivo imaging at clinical resolution. We hypothesize that repeated administration of CA4+ will have no adverse side effects or complications, and that sequential in vivo imaging assessments will distinguish articular cartilage repair tissue from early degenerative and healthy cartilage in critically sized chondral defects. In an established equine translational preclinical model, lameness and synovial effusion scores are similar to controls after repeated injections of CA4+ (eight injections over 16 weeks) compared to controls. Synovial fluid total protein, leukocyte concentration, and sGAG and PGE2 concentrations and articular cartilage and synovial membrane scores are also equivalent to controls. Longitudinal in vivo cationic CECT attenuation in repair tissue is significantly lower than peripheral to (adjacent) and distantly from defects (remote sites) by 4 weeks (p < 0.001), and this difference persists until 16 weeks. At the 6- and 8-week time points, the adjacent locations exhibit significantly lower cationic CECT attenuation compared with the remote sites, reflecting peri-defect degeneration (p < 0.01). Cationic CECT attenuation at clinical resolution significantly correlates with cationic CECT (microCT) (r = 0.69, p < 0.0001), sGAG (r = 0.48, p < 0.0001), and ICRS II histology score (r = 0.63, p < 0.0001). In vivo cationic CECT imaging at clinical resolution distinguishes fibrous repair tissue from degenerative and healthy hyaline cartilage and correlates with molecular tissue properties of articular cartilage.

Pollution Characteristics, Source, and Health Risk Assessment of Metal Elements in PM2.5 Between Winter and Spring in Zhengzhou

A total of 18 metal elements in ambient PM2.5 in Zhengzhou were continuously determined using an online heavy metal observation instrument in January and April, 2021, and the changes in element concentrations were analyzed. Metal elements were traced via enrichment factors, positive matrix factorization (PMF), and a characteristic radar chart. The US EPA health risk assessment model was used to assess the health risks of heavy metals, and the backward trajectory method and the concentration-weighted trajectory (CWT) method were used to evaluate the potential source regions of health risks. The results showed that the element concentrations were higher in spring, and the sum of Fe, Ca, Si, and Al concentrations accounted for 89.8% and 87.5% of the total element concentrations in winter and spring, respectively. Cd was enriched significantly, which was related to human activities. The concentrations of Pb, Se, Zn, Ni, Sb, and K in winter and Cr, Ni, Fe, Mn, V, Ba, Ca, K, Si, and Al in spring increased with the increasing pollution level. The results of PMF and the characteristic radar chart showed that the main sources of metal elements in winter and spring were industry, crust, motor vehicles, and mixed combustion, with industry and mixed combustion pollution occurring more often in winter and crust pollution occurring more often in spring. Significant non-carcinogenic risks existed in both winter and spring with more severe health risks in winter, and Mn caused significant non-carcinogenic risks. The health risks in winter were mainly influenced by Zhengzhou and surrounding cities and long-distance transport in the northwest, and the health risks in spring were mainly influenced by Zhengzhou and surrounding cities.

Cellular absorption and cytotoxic mitigation of heavy metals in mining vegetables in southwest China: Mechanistic insights and health implications

The existing health risk assessment models often rely on total concentrations of contaminants, neglecting cellular absorption, leading to an overestimation of risks due to a lack of toxicological verification. In this study, the content, bioaccessibility, and health risk evaluation of Cr, Ni, Cu, and As in vegetables from mining areas in Southwest China were examined. The cytotoxicity and gastric absorption of heavy metals and underlying mechanisms as well as the toxic mitigation approach after consumption of risky vegetables were explored. Our results showed that the heavy metals in cabbage, celery, and garlic seedlings were within the safety limit, even though grown in contaminated soils. The bioaccessibility of As, Cu, Ni, and Cr in vegetables in the gastric phase is from 6.92% to 81.15%, with mint having the highest bioaccessible concentrations of Cr (32.7 μg/kg), Cu (540.1 μg/kg), and As (103.9 μg/kg). The Hazard Quotient and Hazard Index values of the bioaccessible metals suggested an unacceptable cancer risk. Besides, the vegetable extracts increased cell apoptosis and tight junction disruption. Unexpectedly, the high-risk mint extract with the greatest bioaccessibility didn't cause cytotoxicity but inhibited cell apoptosis and enhanced cellular tight junction, evidenced by the upregulation of Zonula Occludens-1, Occludin, and Claudin 3, and a decrease in cellular heavy metal uptake. Furthermore, the mint extract could alleviate garlic seedling extract-induced cytotoxicity, indicating that the special substance in mint has protective effects. Taken together, special components in vegetables, cellular uptake, and toxicity of heavy metals should be considered in the accurate assessment of health risks.

Agricultural management could reduce soil N2O emissions while increasing grain yields via enhancing soil moisture harvesting and improving soil nutrient status

Intercropping can improve system productivity, but the effect of intercropping integrated with conservation tillage practices on soil N2O emissions remains unclear at the present stage. A 4-yr field experiment was performed in northwest China to examine soil moisture harvesting, soil nutrient status, and soil N2O emissions of wheat-maize intercropping with stubble residues and films management. We found that intercropping increased crop yields and reduced soil N2O emissions over monocultures. Across the intercropping treatments, NTSMFI (no-tillage with mulching stubbles and re-using residual films) and NTSSFI (no-tillage with standing stubbles and re-using residual films) boosted grain-yields by 13.8–17.1 % and 12.9–15.4 % over CTFI (conventional tillage without returning stubbles and mulching new films). NTSMFI and NTSSFI reduced soil N2O emissions by 18.4–28.7 % and 15.5–24.9 % compared to CTFI, respectively. So, NTSMFI and NTSSFI obtained a higher soil N2O emission efficiency than CTFI. The greater effect on soil N2O emissions reduction was detected in NTSMFI, and decreased by 5.1–5.4 % over NTSSFI. The main reason for NTSMFI to improve grain-yields and reduce soil N2O emissions was to enhance soil moisture harvesting and optimize the soil nutrient status. Compared to CTFI, NTSMFI increased the ratio of transpiration to evaporation by 14.4–32.0 %, improved soil organic carbon and total nitrogen concentrations, and soil C:N ratio of 0 to 60 cm soil depth by 14.1 %, 7.1 %, and 6.5 %, respectively. Adopting an environmentally clean strategy exemplified by NTSMFI was recommended as an effective technique for increasing-yields and reducing soil N2O emissions in arid irrigated regions.

Evaluating the Role of Nicotine Stereoisomer on Nicotine Pouch Abuse Liability: A Randomized Crossover Trial.

Many oral nicotine pouch (ONP) brands use synthetic nicotine, which typically contains a racemic (50:50) mixture of nicotine's two stereoisomers: S-nicotine and R-nicotine. Because tobacco-derived nicotine contains more than 99% S-nicotine, the effects of R-nicotine in humans are not well known. We compared systemic nicotine exposure and product appeal of ONPs containing more than 99% S-nicotine versus racemic nicotine. N = 18 adult smokers (Mage = 45 years, 66.7% male, 77.8% White) enrolled in a three-visit single-blind, randomized crossover study. During each visit, participants used one wintergreen-flavored, 3mg nicotine ONP for 30min following at least12h nicotine abstinence. Study ONP #1 contained more than 99% S-nicotine and the other two study ONPs contained racemic nicotine (collapsed for analyses). Plasma nicotine assessments and measures of withdrawal relief occurred at t = 0, 5, 15, 30, 60, and 90min; measures of product appeal were assessed following ONP use. Using the ONP with more than 99% S-nicotine resulted in greater plasma nicotine concentration from 15 to 90min (p < .0001) and greater maximum plasma nicotine concentration than the ONPs with racemic nicotine (M = 9.9ng/mL [SD = 2.5] vs. M = 5.7ng/mL [SD = 2.8], respectively; p < .0001). Product liking and withdrawal relief were similar across ONPs, although participants reported more "bad effects" when using the ONP with more than 99% S-nicotine. Participants reported few subjective differences in ONPs according to nicotine stereoisomer, but plasma nicotine concentration was greater for ONPs using more than 99% S-nicotine. ONPs with more than 99% S-nicotine (vs. racemic nicotine) might be better substitutes for cigarettes, but research into other ONP characteristics (eg flavors, freebasenicotine) is needed to inform regulation. Little is known about the effects of racemic (vs. S-) nicotine in humans. In a sample of adults who smoke cigarettes, we identified that oral nicotine pouches containing racemic nicotine exposed participants to less nicotine than oral nicotine pouches containing only S-nicotine, but both types of oral nicotine pouches held similar, moderate appeal. Additional research evaluating the roles that flavorings, total nicotine concentration, and freebase nicotine play in the abuse liability of oral nicotine pouches would inform comprehensive product regulations to support public health.

Correlating Gas/Particle-Phase Concentration of Indicator Polychlorinated Biphenyls with Meteorological Factors in Bayburt, an Important University City of Turkey

This study was carried out in two seasons in Bayburt University Baberti Campus (BUBC) in Bayburt city, which is an important university city in Turkey. Gas and particle phase atmospheric concentrations of Urban atmospheric Indicator Polychlorinated Biphenyls (i-PCBs: PCB#28, 52, 101, 118, 138, 153, 180) were determined at first. Then, by using different methods, the interactions between i-PCB concentrations and meteorological factors were investigated. Gas and particle phases of atmospheric i-PCB samples were collected using a high-volume air sampler (HVAS) in BUBC . Following this stage, the samples were analyzed in a gas chromatography-mass spectrophotometer (GC-MS) by passing through appropriate extraction steps. According to the data obtained, the average gas phase ∑i-PCB concentration for the summer month was determined to be 11.314 pg/m3 during the sampling period while the average particle phase ∑i-PCB concentration was found to be 2.145 pg/m3. The average gas phase ∑i-PCB concentration was found to be 4.582 pg/m3 for the winter period while it was found to be 1.756 pg/m3 for the average particle phase ∑i-PCB concentration. In addition, the average total concentrations of i-PCBs were calculated to be 19.797 pg/m3. It was determined that meteorological factors especially temperature (from the Clausius–Clapeyron equation), wind velocity and direction, and rainfall have significant impacts on i-PCB concentration and its distribution. In light of these data, i-PCB concentrations determined in the gas phase were found to be higher than those in the particle phase. In addition, concentration rates determined in summer months were calculated to be higher compared to those calculated for winter months.

The relative contributions of traffic and non-traffic sources in ultrafine particle formations in Tehran mega city

Emissions of ultrafine particles (UFPs; diameter < 100 nm) are strongly associated with traffic-related emissions and are a growing global concern in urban environments. The aim of this study was to investigate the variations of particle number concentration (PNC) with a diameter > 10 nm at nine stations and understand the major sources of UFPs (primary vs. secondary) in Tehran megacity. The study was carried out in Tehran in 2020. NOx and PNC were reported from a total of nine urban site locations in Tehran and BC concentrations were examined at two monitoring stations. Data from all stations showed diurnal changes with peak morning and evening rush hours. The hourly PNC was correlated with NOx. PNCs in Tehran were higher compared to those of many cities reported in the literature. The highest concentrations were at District 19 station (traffic) and the lowest was at Punak station (residential) such that the average PNC varied from 8.4 × 103 to 5.7 × 104 cm−3. In Ray and Sharif stations, the average contributions of primary and secondary sources of PNC were 67 and 33%, respectively. Overall, we conclude that a decrease in primary emission leads to a decrease in the total concentration of aerosols, despite an increase in the formation of new particles by photo nucleation.

A self-driven multifunctional microfluidic sweat analysis system for efficient sweat collection and real-time monitoring

Wearable sweat sensors offer the opportunity for non-invasive and real-time monitoring of metabolite information in sweat, enabling individuals to dynamically monitor their physiology states at the molecular level. However, sweat possesses characteristics such as small volume, volatility, susceptibility to epidermal contamination, and low analyte concentrations, making its reliable collection and detection challenge for wearable sweat sensors. In this work, we develop a self-driven multifunctional microfluidic sweat analysis system (SMMSAS) for efficient sweat collection and detection. The SMMSAS features with a wetting contrast for the sweat, which comprises superhydrophobic inlet, superhydrophilic microchannel enriched with nanofiber, and an absorbent test paper. Such a feature enables the spontaneous sweat transports in the form of dropwise due to the exertion of “Laplace force-capillary force-capillary force” on sweat, thereby facilitating the real-time sweat detection. SMMSAS integrated with the functions of impedance and colorimetry analysis is able to simultaneously record the multiple information in sweat, including sweat volume, sweating rate, total electrolyte concentration, glucose concentration, and pH value, all of which are important to reflect the physiological state of the human body. We also demonstrate the capability of SMMSAS in real-time monitoring the sweating conditions of the human body, which is attributed to its fast responsiveness (∼ 100 ms) for the wide range sweating rate (0.5−15 μL/min) and various total electrolyte concentration (0−80 mM), paving the way for next-generation personalized healthcare.

Phthalate alternatives and their monoesters in indoor dust from several regions, China and implications for human exposure

Household products, in response to regulations, increasingly incorporate phthalate (PAE) alternatives instead of traditional PAEs. However, limited information exists regarding the fate and exposure risk of these PAE alternatives and their monoesters in indoor environments. The contamination levels of PAE alternatives and their monoesters in indoor dust might vary across regions due to climate, population density, industrial activities, and interior decoration practices. By analyzing indoor dust samples from six geographical regions across China, this study aims to shed light on concentrations, profiles, and human exposure to 12 PAE alternatives and 9 their monoesters. Bis(2-ethylhexyl) benzene-1,4-dicarboxylate (DEHTP), tributyl 2-acetyloxypropane-1,2,3-tricarboxylate (ATBC), and tris(2-ethylhexyl) benzene-1,2,4-tricarboxylate (TOTM) were the main PAE alternatives in dust across all regions. The total concentrations of 12 PAE alternatives ranged from 0.125 to 4160 μg/g in indoor dust. High molecular weight PAE alternatives had significantly correlated concentrations (p < 0.05) based on Spearman analysis, suggesting their co-use in heat-resistant plastic products. A collective of nine monoesters were identified in most samples, with total concentrations ranging from 0.048 to 29.6 μg/g. The median concentrations of PAE alternatives were highest in North China (66.8 μg/g), while those of monoesters were highest in Southwest China (6.93 μg/g). A significant correlation (p < 0.05) between the concentrations of DEHTP and its monoester suggested that degradation could be a potential source of monoesters. Although hazard quotients (HQs) have been calculated to suggest that the current exposure is unlikely to pose a significant health risk, the lack of toxicity threshold data and the existence of additional exposure pathways necessitate a further confirmation.

Freezing-enhanced degradation of azo dyes in the chloride-peroxymonosulfate system

In this study, we investigated the freezing-induced acceleration of dye bleaching by chloride-activated peroxymonosulfate (PMS). It has been observed that the oxidation of chloride by PMS generates a free chlorine species, such as hypochlorous acid (HOCl), under mild acidic and circumneutral pH condition. This process is the major reason for the enhanced oxidation capacity for electron-rich organic compounds (e.g., phenol) in the chloride-PMS system. However, we demonstrated that the chloride-PMS system clearly reduced the total organic carbon concentration (TOC), whereas the HOCl system did not lead to decrease in TOC. Overall, the chemical reaction is negligible in an aqueous condition if the concentrations of reagents are low, and freezing the solution accelerates the degradation of dye pollutants remarkably. Most notably, the pseudo-first order kinetic rate constant for acid orange 7 (AO7) degradation is approximately 0.252 h−1 with 0.5 mM PMS, 1 mM NaCl, initial pH 3, and a freezing temperature of −20 °C. AO7 degradation is not observed when the solution is not frozen. According to a confocal Raman-microscope analysis and an experiment that used an extremely high dose of reactants, the freeze concentration effect is the main reason for the acceleration phenomenon. Because the freezing phenomenon is spontaneous at high latitudes and at mid-latitudes in winter, and the chloride is ubiquitous elsewhere, the frozen chloride-PMS system has potential as a method for energy-free and eco-friendly technology for the degradation of organic pollutants in cold environments.

285 Impact of feeding strategies on semen concentration, motility, and morphology of the mature AI boar

Abstract The objective of this experiment was to determine if varying feeding strategies of maintenance requirements of boars impacts semen concentration, motility, morphology, and cortisol of the working boar. This experiment was conducted at Purdue University over two 9-wk periods with 1-wk before each 9-wk period serving as baseline for analysis. Boars (n = 28; Acuity and Topig Norvsin) from two age groups (9 and 15 mo) and two genetics (maternal and terminal) were used. Boars were blocked by breed and age and randomly allocated to receive one of three feed intake levels of a corn-soybean meal-based diet formulated to meet NRC (2012) maintenance requirements: HIGH (150% maintenance, n = 9); MAIN (100% maintenance, n = 10); and LOW (80% maintenance, n = 9) during the first 9-wk period. During the second 9-wk period remaining HIGH and LOW boars were crossed-over to opposite treatments (HIGH-LOW, n = 9; LOW-HIGH, n = 7), and maintenance boars were unchanged (MAIN-MAIN, n = 8). Semen was collected once/wk using the gloved hand method and 3 mL of ejaculate was diluted in 27 mL of extender (Androhep Plus, Minitube). Semen concentration (Nucleocounter SP-100), motility (Computer Assisted Sperm Analysis, CASA, CEROS II), and sperm cell morphology (phase-contrast, bright-field microscopy) were analyzed. Data were analyzed using PROC MIXED in SAS 9.4 with boar as experimental unit with main effects of feed intake and age with phase (3-wk period) as repeated measure. Significance was determined at P &amp;lt; 0.05 and a trend 0.05 &amp;lt; P ≤ 0.10. Three-way interactions for the first 9-wk period of feed intake*age*phase was observed for total sperm (P &amp;lt; 0.10) and total normal sperm (P &amp;lt; 0.05) with old boars fed HIGH treatment increasing sperm production, but old boars fed MAIN and LOW decreasing sperm production while young boars had minimal changes in sperm production regardless of feeding levels in the first 9-wk period. No other interactions or main effects were observed for the first period. During the second 9-wk period two-way interactions were observed for total sperm (FI*Age; P &amp;lt; 0.05) and total normal sperm (FI*Age; P &amp;lt; 0.01) with old LOW-HIGH boars having the highest total sperm and total normal sperm concentrations and young LOW-HIGH boars having the least total sperm and total normal sperm concentrations. HIGH-LOW fed boars had the greatest decrease in semen volume compared with the other treatments (FI*Phase; P &amp;lt; 0.01). Boars fed MAIN had minimal impacts on semen parameters compared with HIGH and LOW feed intake treatments. HIGH and LOW feed intake was observed to impact semen parameters in old boars faster than young boars with neither age being able to return to their baseline semen parameters observed at the start of the trial. Future research is needed with varying ages and feed intakes to better understand how nutritional strategies impact semen quantity and quality in the boar stud.

PSVI-4 Effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet

Abstract The objective was to characterize the effects of ruminal acidosis on rumen fermentation of steers adapted to a high concentrate diet. Cattle entering the feedlot undergo a transition period where the amount of concentrates in the diet is gradually increased to mitigate the risks of ruminal acidosis. Despite a dietary adaptation, rumen acidosis still affects feedlot cattle later in the finishing phase. Ruminally cannulated steers [n = 11; body weight (BW) = 795 kg ± 54) were blocked into 2 groups based on initial BW. Before the start of the study, cattle had been consuming a finishing diet (60% dry rolled corn, 15% modified distiller’s grains, 15% corn silage, and 10% ground corn based supplement) for more than 150 d. Steers were randomly assigned to 1 of 2 treatments: control (CON) or acidosis (ACD). For the experiment, steers were fasted for 24 h and at the conclusion received the same finishing diet. Steers on ACD steers were also ruminally dosed 0.05% BW of wheat starch on h 0 and h 12 to induce acidosis. Rumen fluid was collected every 4 h for 48 h to analyze ruminal pH, ammonia, volatile fatty acids (VFA), and lactate. Fecal grab samples were collected every 8 h for 48 h to determine fecal pH. Data were analyzed with the MIXED procedure of SAS 9.4 with the effects of treatment, time, and their interaction. A treatment × hour (P &amp;lt; 0.01) effect was observed for ruminal pH with the ACD steers having a lower pH than CON from h 12 to 32. Fecal pH was not affected by treatment, time, or their interaction (P ≥ 0.12). Steers fed ACD had greater total VFA concentration than CON (P &amp;lt; 0.01). A treatment × hour interaction (P &amp;lt; 0.01) was observed for acetate molar proportion with CON having greater percentage acetate at h 24 through 32. Additionally, there was a treatment × hour interaction (P &amp;lt; 0.01) for propionate molar proportion with ACD steers having greater propionate at h 28 and 32, and then at h 40 and 44. Butyrate was not affected (P ≥ 0.58) by treatment × hour or treatment. Acetate to propionate ratio (A:P) was affected by treatment × hour (P &amp;lt; 0.01) with CON steers having greater A:P after h 28. Rumen ammonia and lactate concentrations did not differ (P ≥ 0.25) by treatment or the interaction with h. In steers adapted to a high concentrate diet, acidosis only altered ruminal fermentation in regards to ruminal pH and VFA concentrations.

Microbial production of 3-hydroxypropionic acid by acetic acid bacteria: Modeling including the buffering capacity of the biological medium enables prediction of pH and metabolite concentrations

A mathematical model of the fed-batch bioconversion of 1,3-propanediol into 3-hydroxypropionic acid using acetic acid bacteria is proposed. The model includes the microbial growth, the oxidation of 1,3-propanediol to 3-hydroxypropionaldehyde followed by a second oxidation reaction to 3-hydroxypropionic acid. The inhibitory effect of the total acid concentration upon the biological reactions was considered as well as the effect of pH on bacterial growth. A special attention was paid to make accurate pH predictions as pH is a key parameter that influences the microbial growth and bioconversion and also defines the strategy of downstream processing for acid recovery. The buffering capacity of the complex biological medium was found to change throughout the bioconversion. In addition to describing satisfactorily a set of experiments reported in the literature, the model was successfully used to predict metabolite concentrations and the resulting pH in new operating conditions with free pH dynamics. A sensitivity analysis was performed to identify the most influential parameters of the model. The proposed model represents a valuable tool for bioprocess design as it describes the detailed kinetics of 1,3-propanediol oxidation to 3-hydroxypropionic acid by acetic acid bacteria in bioreactor. Additionally, the pH prediction is a major feature of this model, which could guide the identification of optimal operating conditions for microbial activity with a simultaneous in-situ recovery process.

Optimization of foam mat drying using Central Composite Design to produce mixed juice powder: A process and characterization study

This study aimed to optimize the mixed juice powder through foam mat drying to achieve a high solubility index. The process variables were optimized using a central composite design, assessing the influence of foaming agent concentration (5, 10, and 15) (% w/w), drying temperature (50, 60, and 70) °C, and foam thickness (2, 4, and 6) mm on powder solubility. The optimized juice was evaluated for the physical, chemical, technological characteristics and bioactive compounds. The optimal conditions were determined as a drying temperature (60.27 °C), foam thickness (2.82 mm), and 8.56 (% w/w) maltodextrin. The final product characterization revealed notable properties, including a soluble solids content of 8.75 °Brix, pH of 4.48 ± 0.01, and water activity of 0.44 ± 0.04. The analysis covered aspects related to color, porosity, sedimentation index, and solubility, highlighting a browning index of 0.81 ± 0.03. The powder microstructure exhibited a variety of shapes, reflecting the stability of the foam. The results confirmed the stability of the mixed juice powder, indicating that it maintained a consistent total carotenoid concentration of 10.65 μg/g and preserved its physicochemical characteristics. The cubic response surface model was the most suitable for solubility response with maximum value desirability (1.00).