During the dismantling of nuclear facilities, a large quantity of radioactive concrete is generated and chelating agents are required for the decontamination process. However, disposing of environmentally persistent chelated wastes without eliminating the chelating agents might increase the rate of radionuclide migration. This paper reports a rapid and straightforward ion chromatography method for the quantification of citric acid (CA), a commonly used chelating agent. The findings demonstrate acceptable recovery yields, linearities, and reproducibilities of the simulated samples, confirming the validity of the proposed method. The selectivity of the proposed method was confirmed by effectively separating CA from gluconic acid, a common constituent in concretes. The limits of detection and quantification of the method were 0.679 and 2.059 mg·L−1, respectively, while the recovery yield, indicative of the consistency between theoretical and experimental concentrations, was 85%. The method was also employed for the quantification of CA in a real concrete sample. These results highlight the potential of this approach for CA detection in radioactive concrete waste, as well as in other types of nuclear wastes.

Low- and intermediate-level radioactive waste for permanent disposal often contains organic complexing agents, so-called chelating agents. Organic complexing agents, which are polycarboxylic acids, can increase the mobility of radionuclides into the environment by forming water-soluble complexes with most heavy metals. Therefore, analyzing the complexing agents in radioactive waste is crucial for comprehensive management of nuclear wastes. According to regulatory guidelines, specifically Notice No. 2021-16 issued by the Nuclear Safety and Security Commission, the determination of chelating agent content in radioactive waste materials is required to ensure proper management and safe disposal. However, only a few methods are available to analyze the chelators in various matrices such as concrete, metals, soil, and mixed solid wastes like plastics, vinyl, and rubber. Recently, we found a UV-Vis method based on an enzymatic reaction is inadequate for analyzing citric acid in radioactive waste with a complex matrix like concrete. To address this, we developed a method to determine the contents of EDTA and NTA using a UV-Vis spectrophotometer and citric acid using ion chromatography. The results showed good validity and reliability to determine the chelating agents in various radioactive wastes.

Müllerian inhibiting substance (MIS) is a protein that encoded by MIS gene. It has also been called Müllerian inhibiting factor (MIF) and anti-Müllerian hormone (AMH). Mis expression occurs in ovarian granulose cells of females postpartum, and serves as a molecular biomarker for relative size of the ovarian reserve. In humans, the number of cells in the follicular reserve can be used to evaluate the reproductive function and fertility of female. Pagrus major is typical cultured fish in Korea but there is no clear evidence for their gene identification. However, in many teleost, MIS genes were demonstrated already. Present study aimed to identify the Mis gene in Pagrus major and seasonal difference of its expression. Using conserved sequence of the other known teleost Mis genes, we make conserved primers. Pagrus major’s ovary samples were obtained from the sea rim farm (Geoje, Korea) and kept in RNAlater®Solution or fixed in 4% paraformaldehyde containing 0.16% picric acid. RNA was isolated from kept sample and cDNA was synthesized. The PCR products were performed ligation with TOPO vector and transformation in TOP10 cell and sequenced the Mis mRNA fragment. MIS was localized in the follicle cells. Its mRNA levels were higher in summer than spring or fall. Based on them, it is suggested that MIS can be used to estimate the fertility of this fish.

Dormant blastocysts during delayed implantation exhibit heightened autophagic activation. Activation of autophagy, the self-eating process within cells, was suggested as an adaptive response to unfavorable environment of prolonged survival in utero. During the course of this study, we observed by transmission electron microscopy that multivesicular bodies (MVBs) accumulate in the trophectoderm of dormant blastocysts upon activation of implantation by estrogen. MVBs are the late endosomes which are characterized by the presence of diverse internal vesicles within a large vesicle. Autophagosomes fuse with MVBs during autophagic activation, and efficient autophagic degradation requires functional MVBs. Biogenesis of MVBs depends on a dynamic network of ESCRT complexes 0, I, II, and III. Tsg101 (a component of the ESCRT-I complex) and CD63 are often used as a marker of MVBs. Lysobisphosphatidic acid (LBPA) is an abundant lipid in MVBs and required for the formation of MVBs. In this study, we performed immunofluorescence staining for detection of MVB makers in dormant and activated embryo. In dormant blastocysts, expression of Tsg101 and LBPA exhibited a uniform pattern throughout the trophectoderm. In contrast, expression of both markers prominently increased in the mural trophectoderm of activated blastocysts. To investigate the relationship with MVB formation and autophagy activation in activated blastocyst, 3-MA, a widely used inhibitor of autophagy, was daily injected intraperitoneally to ovx mice. Interestingly, 3-MA injection to block autophagy during delayed implantation led to a reduction of the signal of MVB markers, suggesting that prolonged activation of autophagy in dormant blastocysts is associated with MVB formation upon activation of implantation. Collectively, these results show that expression of MVB makers increase in the trophectoderm of blastocysts upon activation of implantation and that the formation of MVB is associated with heightened autophagy during delayed implantation.

Human serum (HS) has been reported to induce aggregation of human eyelid adipose-derived stem cells (HEACs) during high-density culture in vitro. The present study focused on the role of cell adhesion molecules and gelatinases during HS-induced aggregation of HEACs. HS-induced aggregation occurred between 9-15 days of culture. Cells aggregated by HS medium (HS-agg) showed stronger expression of α2, α2B, αX, and CEACAM1 genes compared to non-aggregated cells in HS medium (HS-ex) or in control FBS-cultured cells. HS-agg were distinctly labeled with antibodies against α2, α2B, and αX proteins. Western blot results demonstrated that the two integrin proteins were greatly expressed in HS-agg compared to HS-ex and control FBS-cultured cells. Treatment of HEACs with anti-integrin α2 antibody during culture in HS medium delayed aggregation formation. HS-agg exhibited strong expression of MMP1 and MMP9 compared to HS-ex or FBS-cultured cells. Conditioned media from HS-culture showed remarkable increase of MMP9 gelatinolytic activity in comparison to those from FBS-culture. However, there was no change of TIMP mRNA expression in relation to the HS-induced aggregation. Based on these results, it is suggested that integrin α2, α2B, and αX, and MMP9 might play an important role in the HS-induced aggregation of HEACs.

The Egr family of zinc finger transcription factors consisting of 4 members (Egr1 to -4) regulates critical genetic programs involved in cellular growth, differentiation, and function. Especially, the critical role for Egr1 in regulating luteinizing hormone responsiveness was demonstrated by using gene-targeted mouse models. Other members of Egr family were shown to be involved in other cellular and developmental processes. To understand if Egr3 is implicated in ovarian functions, we focused on identifying cell type-specific and subcellular localization of Egr3 in cycling mouse ovaries and oocytes. RT-PCR analyses show that Egr3 mRNA is expressed in the mouse ovary and oocytes. By immunofluorescence staining, we observed that Egr3 is weakly expressed in subsets of granulosa cells. Interestingly, Egr3 seems to be co-localized with meiotic spindle in some oocytes in the ovarian section. Therefore, we examined Egr3 localization in MI oocytes cultured in vitro. We confirmed co-localization of Egr3 and microtubule in the mouse oocyte during meiosis I. Egr3 localization is noted around condensing chromosomes during prometaphase I (PMI). At metaphase I (MI) and MII, Egr3 is localized on meiotic spindle and also around each cytosolic microtubule organizing centers (MTOCs) in a punctate pattern. To examine if microtubule is required for correct positioning of Egr3 on this structure, we observed the pattern of Egr3 in oocytes matured under taxol or nocodazole. In taxol-treated oocyte, Egr3 and gamma-tubulin complex are enlarged. In nocodazole-treated oocyte, Egr3 localization on spindle and MTOCs are abolished. Thus, Egr3 localization seems to require the presence of intact microtubule. Collectively, our result shows for the first time that Egr3, a transcription factor, is localized on meiotic spindle of maturing mouse oocytes. The work suggests a novel role for Egr3 as a factor involved in MTOC dynamics during meiosis.