3-Methyl-4-nitrophenol Exposure Deteriorates Oocyte Maturation by Inducing Spindle Instability and Mitochondrial Dysfunction.

3-methyl-4-nitrophenol (PNMC), a well-known constituent of diesel exhaust particles and degradation products of insecticide fenitrothion, is a widely distributed environmental contaminant. PNMC is toxic to the female reproductive system; however, how it affects meiosis progression in oocytes is unknown. In this study, in vitro maturation of mouse oocytes was applied to investigate the deleterious effects of PNMC. We found that exposure to PNMC significantly compromised oocyte maturation. PNMC disturbed the spindle stability; specifically, it decreased the spindle density and increased the spindle length. The weakened spindle pole location of microtubule-severing enzyme Fignl1 may result in a defective spindle apparatus in PNMC-exposed oocytes. PNMC exposure induced significant mitochondrial dysfunction, including mitochondria distribution, ATP production, mitochondrial membrane potential, and ROS accumulation. The mRNA levels of the mitochondria-related genes were also significantly impaired. Finally, the above-mentioned alterations triggered early apoptosis in the oocytes. In conclusion, PNMC exposure affected oocyte maturation and quality through the regulation of spindle stability and mitochondrial function.

Removal of heavy metals in water-extracted solution through adsorption by palygorskite and stabilization by comilling.

Removing water-soluble chlorides (WSCs) through water extraction is a common pretreatment technology for recycling municipal solid waste incineration (MSWI) fly ash (FA). However, the extracted solution often contains heavy metals, the concentrations of which exceed standards for effluent. This study aims to investigate the adsorption of heavy metals by palygorskite in water-extracted solution and explore the feasibility of stabilizing heavy metals through comilling palygorskite-adsorbed heavy metals (PAHMs) with water-extracted fly ash (WFA). The experimental parameters include: two-stage water extraction with a liquid-to-solid ratio of 5, adding 0, 0.125, 0.25, 0.5, 1, 2 or 3 g of palygorskite to 100 mL of water-extracted solution, and comilling the mixture of PAHMs and WFA for 0, 0.5, 1, 2, 4, 8, 12, 24 or 96 hours. The experimental results revealed that 3 g of palygorskite in 100 mL of extracted solution could absorb Pb, Cd, Cr, Cu and Zn, meeting the effluent standards. The total amount of Pb, Cd, Cr, Cu and Zn removal rate reached 99.7%. Moreover, 98.44% of the WSCs were not adsorbed, the water extraction process for removing WSCs was not compromised. After the comilling of PAHMs and WFA, the distribution of the heavy metals in the milled blended powder was greater than 99.44%; moreover, toxicity characteristic leaching procedure concentrations were determined to conform to regulatory standards, and the sequential extraction procedure revealed that the heavy metals tended to be in stable fractions. This achieves the goal of preventing secondary pollution from heavy metals during the MSWI FA recycling process.

TET Family Members Are Integral to Porcine Oocyte Maturation and Parthenogenetic Pre-Implantation Embryogenesis.

The ten-eleven translocation (TET) enzyme family, which includes TET1/2/3, participates in active DNA demethylation in the eukaryotic genome; moreover, TET1/2/3 are functionally redundant in mice embryos. However, the combined effect of TET1/2/3 triple-gene knockdown or knockout on the porcine oocytes or embryos is still unclear. In this study, using Bobcat339, a specific small-molecule inhibitor of the TET family, we explored the effects of TET enzymes on oocyte maturation and early embryogenesis in pigs. Our results revealed that Bobcat339 treatment blocked porcine oocyte maturation and triggered early apoptosis. Furthermore, in the Bobcat339-treated oocytes, spindle architecture and chromosome alignment were disrupted, probably due to the huge loss of 5-hydroxymethylcytosine (5hmC)and concurrent increase in 5-methylcytosine (5mC). After Bobcat339 treatment, early parthenogenetic embryos exhibited abnormal 5mC and 5hmC levels, which resulted in compromised cleavage and blastocyst rate. The mRNA levels of EIF1A and DPPA2 (ZGA marker genes) were significantly decreased, which may explain why the embryos were arrested at the 4-cell stage after Bobcat339 treatment. In addition, the mRNA levels of pluripotency-related genes OCT4 and NANOG were declined after Bobcat339 treatment. RNA sequencing analysis revealed differentially expressed genes in Bobcat339-treated embryos at the 4-cell stage, which were significantly enriched in cell proliferation, cell component related to mitochondrion, and cell adhesion molecule binding. Our results indicated that TET proteins are essential for porcine oocyte maturation and early embryogenesis, and they act by mediating 5mC/5hmC levels and gene transcription.

Effects of Chlorella sp. on nutrient treatment in cultures with different carbon to nitrogen ratios.

Chlorella sp. is often used in the treatment of wastewater to produce lipids, a practice which could go beyond wastewater treatment and be used to generate green energy. Our objectives here are to explore how the ratio of carbon to nitrogen (C/N) affects the removal of carbon and nitrogen in a wastewater treatment system, while simultaneously generating biomass and lipids. In this study, the C/N ratio is adjusted to 0.002, 6, 8, 10, 12 and 32. The results indicate that a C/N of 10 is sufficient to ensure the consumption of carbon and nitrogen, achieving the lowest concentration in the shortest culturing time (32 h). When nitrogen is lacking in the culture, there will be a slight decrease in the rate of carbon consumption which leads to a limitation of nitrogen and an increase in the lipid/cell density even at 96 h of culture time. The highest lipid content (0.57 g/L) and lipid increase rate (0.4 g/L) occurs with a C/N of 32. The greatest amount of biomass, 1.42 g/L is achieved when the C/N is 32. The carbon concentration is the main factor affecting the nitrogen consumption and the increase in the biomass and lipid content.

Improving the mechanical characteristics and restraining heavy metal evaporation from sintered municipal solid waste incinerator fly ash by wet milling.

The milling process has a verified stabilizing effect on the leaching of heavy metals into the environment from municipal solid waste incinerator (MSWI) fly ash. The aim of this current study is to further improve and confirm the effectiveness of the process by exploring its effects on the evaporation of heavy metals and on the mechanical characteristics of the sintered MSWI fly ash. The chemical composition of the MSWI fly ash is first altered by the addition of water treatment plant sludge (WTS) and cullet, and then processed to produce sintered specimens suitable for reuse as an aggregate. In the experiments, fly ash, WTS and cullet (40%: 30%: 30%, respectively) were mixed and milled for 1h. Samples were sintered for 60 min at temperatures of 850, 900, 950 and 1000°C. Test results confirm that milling increased the compressive strength of the sintered specimens. The compressive strength of unmilled specimens sintered at 900°C was only 90 kg/cm(2), but that of milled specimens was 298 kg/cm(2) when sintered at only 850°C. There was also an improvement in the soundness ranging from 11.04% to 0.02% and a reduction in the evaporation rates of Pb, Cd, Cu, Cr and Zn from 54-64%, 43-49%, 38-43%, 30-40% and 14-35% (900-1000°C) to 19-21%, 19-21%, 14-19%, 12-19% and 14-17% (850-1000°C), respectively. The improvement in compressive strength was attained by the combination in the liquid sintering stage of powdered ash with the amorphous material. The amorphousness of the material also helped to seal the surface of the fly ash, thereby reducing the evaporation of heavy metals during the heating process.

Effect of the milling solution on lead stabilization in municipal solid waste incinerator fly ash during the milling processes.

The wet milling process had been found to effectively stabilize lead in fly ash. This study adopts this method and looks at the effect of different milling solutions to improve the efficiency of lead stabilization. Different milling solutions (water, phosphoric acid and ethanol) and different milling times (1, 24, 48 and 96 h) were selected as parameters. Since lead oxide can be identified by XRD in this experiment's samples, 5% lead oxide was added to the extracted mixed fly ash to make instrumental analysis easier. The experimental results indicate that the effect of stabilization of lead after milling could exceed 96%. During milling with water, considerable lead leached into the water in the initial stage (1 h) of the process, but a stable level was reached as the milling time increased. After milling with ethanol and 0.2 M phosphoric acids, the efficiency could exceed 93% after 1 h of milling time. The results of the sequential extraction procedure (SEP) results show that the residual fraction could be increased from 8.93% to 56.16% when a 0.2 M phosphoric acid solution was used. Clearly the choice of an appropriate milling solution can enhance lead stabilization in the fly ash.

Roentgen stereophotogrammetric analysis and clinical assessment of unipolar versus bipolar hemiarthroplasty for subcapital femur fracture: a randomized prospective study.

BACKGROUND: Hemiarthroplasty is a well-established treatment for displaced subcapital fracture, but controversy exists about the optimal implant type. Bipolar hemiarthroplasty has proposed advantages over unipolar hemiarthroplasty in terms of better clinical results and decreased wear of acetabular cartilage. METHODS: This study is a randomized prospective study of 51 patients (52 hips) receiving either bipolar or unipolar hemiarthroplasty for displaced subcapital fractures. The outcome measurements were clinical scores and Roentgen stereophotogrammetric analysis (RSA) analysis to determine the rate of acetabular wear. RESULTS: Twenty-three patients completed 2-year follow-up. The RSA data demonstrated that there was slightly less acetabular wear by bipolar prostheses than by unipolar. The combined mean three-dimensional wear of the bipolar prostheses was 0.6 mm compared with 1.5 mm for the unipolar prostheses (P= 0.04). The bipolar group generally achieved higher scores in terms of the Harris Hip Score, Western Ontario and McMaster University Index of Osteoarthritis (WOMAC) questionnaire and 6-min walk test. These results were statistically significant at 3 months but not at 12 and 24 months. CONCLUSION: This study suggests that while the bipolar prosthesis performs slightly better than the unipolar in terms of acetabular cartilage wear and clinical outcomes, it remains debatable whether the benefits are worth the increased cost of the prosthesis.

Effects of wet ball milling on lead stabilization and particle size variation in municipal solid waste incinerator fly ash.

Water-extracted municipal solid waste incinerator (MSWI) fly ash was treated by a process of wet ball milling, using desalinated water as the milling solution. We investigated the influence of the milling process on the partitioning and leaching characteristics of lead (Pb) and the particle size distribution. The results show that 93.11% of the Pb was partitioned into the milled ash, 2.60% to the milling balls, and 0.17% to the inner surface of the milling jar, while amounts lower than the detection limit remained in the milled solution. As tested by the toxicity characteristic leaching procedure (TCLP), the leaching of Pb was inhibited after short-term grinding (from 5.2 to 1.2mg/L after 1h of milling), and further reduced by about 96% after 96h of ball milling. The mobility of the heavy metal was analyzed after a sequential extraction procedure. The results also show that Pb tended to become more stable after milling. The size distribution of particles was analyzed by a laser particle diameter analyzer and their morphology during grinding was observed using scanning electron microscopy. The median size of the fly ash decreased significantly from 36 to 5 microm after 0.5h of milling, but then only slightly, from 5 to 2 microm, with further milling from 0.5 to 96 h, due to the concurrent actions of fragmentation and/or agglomeration. The reason for the stabilization of Pb by ball milling was probably that Pb was sealed in the milled fly ash during the fragmentation and agglomeration of particles.

Comparison of cementing techniques of the tibial component in total knee replacement.

A few studies have shown that cementing the stem enhances fixation of the tibial baseplate in total knee replacement (TKR). Even the horizontal technique has been shown to provide good fixation. We used radiostereometry to study migration of the tibial component in 30 knees operated with Profix TKR. The knees were randomised for either complete (both under the baseplate and around the stem) or horizontal (only under the baseplate) cementing of the tibial component. At two years the tibial baseplate rotated externally a median of 0.18 degrees in the uncemented stem group and internally a median of 0.23 degrees in the cemented stem group. The tibial baseplate subsided 0.14 mm in the cemented stem group, and no translation was seen in the uncemented stem group. The differences in migration were small and probably without clinical significance. The findings do not favour either of the cementing techniques in TKR.

Very low wear of non-remelted highly cross-linked polyethylene cups: an RSA study lasting up to 6 years.

BACKGROUND AND PURPOSE: Highly cross-linked polyethylenes (PEs) all appear to reduce wear dramatically in laboratory studies, although there is substantial variation in this respect between manufacturers. Nonremelted cross-linked PE is almost as tough as unirradiated PE, but is not completely stable and can oxidize in vivo, as has been shown in recent retrievals studies. We had reported low wear and good clinical performance after 2 years for 10 non-remelted highly crosslinked PE cups compared to 16 conventional PE cups sterilized by gamma-in-air. METHOD: Because of possible degradation by free radicals, we followed up both cohorts for 5 years (conventional PE) and 6 years (highly cross-linked PE). RESULT: Mean (CI) proximal head penetration over the observation time was linear and measured 0.08 (0.02-0.13) mm for cross-linked PE and 0.42 (0.23-0.62) mm for conventional PE, and total penetration was 0.23 (0.1-0.35) mm and 0.75 (0.05-1.4) mm respectively. After subtracting creep, the annual wear for non-remelted highly cross-linked PE was below 6 microm. The cups had equally low migration and few radiolucencies. INTERPRETATION: The theoretical possibility of oxidation in non-remelted highly cross-linked PE may not show clinically. However, it may be that cemented cups with their thicker PE are more forgiving than metal-backed cups with thin PE moving in the locking mechanism. So far, we can conclude that the Crossfire highly crosslinked polyethylene cups performed very well clinically, with extremely low wear even after almost 6 years. This is reassuring, but care should be taken in extrapolating these results to other cross-linked PEs or uncemented cups where toughness of PE is more of an issue.