• Nuclear Engineering and Technology
• /
• 제54권6호
• /
• pp.2204-2212
• /
• 2022

Recently, the demand for alpha imaging detectors for quantifying the distributions of alpha particles has increased in various fields. This study aims to reconstruct a high-resolution image from an alpha imaging detector by applying a super-spatial resolution method combined with the maximum-likelihood expectation maximization (MLEM) algorithm. To perform the super-spatial resolution method, several images are acquired while slightly moving the detector to predefined positions. Then, a forward model for imaging is established by the system matrix containing the mechanical shifts, subsampling, and measured point-spread function of the imaging system. Using the measured images and system matrix, the MLEM algorithm is implemented, which converges towards a high-resolution image. We evaluated the performance of the proposed method through the Monte Carlo simulations and phantom experiments. The results showed that the super-spatial resolution method was successfully applied to the alpha imaging detector. The spatial resolution of the resultant image was improved by approximately 12% using four images. Overall, the study's outcomes demonstrate the feasibility of the super-spatial resolution method for the alpha imaging detector. Possible applications of the proposed method include high-resolution imaging for alpha particles of in vitro sliced tissue and pre-clinical biologic assessments for targeted alpha therapy.

• Journal of Veterinary Science
• /
• 제21권6호
• /
• pp.83.1-83.14
• /
• 2020

Background: Bovine and porcine teeth are often used in in vitro experiments as substitutes of human teeth. Objectives: The aim of the present study was to perform a comparative analysis of enamel morphology of permanent human, bovine and porcine teeth under the scanning electron microscope. Methods: As many as 10 human, 10 bovine, and 10 porcine teeth were studied. All the teeth were sectioned and the halves were randomly divided into 2 groups according to the examined tissue (vestibular enamel at the mid-height of the dental crown and in the cervical area). Human and bovine enamel was etched for 15 sec and porcine enamel for 30 sec. The scanning electron microscope analysis was performed. The length and width of enamel prisms were determined with the "Met-Ilo" 1.1 computer program. Results: All enamel samples revealed the same etching pattern-Silverstone's type 2. Bovine enamel showed a similar porosity and the amount of interprismatic enamel compared to human enamel while the amount and width of interprismatic enamel bands in porcine enamel were evidently greater. The shape of the porcine prisms was visually similar to human prisms, although dimensions were significantly different. However, bovine prisms differed in form and appeared to be distinctly elongated. Conclusions: Reported findings indicate that the results of experimental studies carried out on bovine and porcine enamel should not be compared with the results obtained on human enamel.

• Nuclear Engineering and Technology
• /
• 제55권8호
• /
• pp.2734-2741
• /
• 2023

Brachytherapy is a special case of radiotherapy. It should be arranged according to some principles in medical radiation applications and radiation physics. The primary principle is to use as low as reasonably achievable dose in all ionizing radiation applications for diagnostic and therapeutic treatments. Dosimetric distributions are dependent on radioactive source properties and radiation-matter interactions in an absorber medium such as phantom or tissue. In this consideration, the geometrical structure and material of the seed capsule, which surrounds a radioactive material, are directly responsible for isodose profiles and dosimetric functions. In this study, the radiometric properties of capsule material were investigated on dose distribution in a water phantom by changing its nuclear properties using the EGSnrc Monte Carlo (MC) simulation code. Effective atomic numbers of hypothetic mixtures were calculated by using different elements with several fractions for capsule material. Model 6711 brachytherapy seed was modeled by EGSnrc/Dosrcnrc Code and dosimetric functions were calculated. As a result, dosimetric parameters of hypothetic sources have been acquired in large-scale atomic number. Dosimetric deviations between the data of hypothetic seeds and the original one were analyzed. Unit dose (Gy/Particle) distributions belonging to different types of material in seed capsule have remarkably differed from the original capsule's data. Capsule type is major variable to manage the expected dose profile and isodose distribution around a seed. This study shows us systematically varied scale of material type (cross section or effective atomic number dependent) offers selective material usage in production of seed capsules for the expected isodose profile of a specific source.

• 한국식물학회:학술대회논문집
• /
• 한국식물학회 1995년도 식물학심포지움 식물로부터 유용 2차대사산물의 생산 PRODUCTION OF USEFUL SECONDARY METABOLITES FROM PLANTS
• /
• pp.67-78
• /
• 1995

Monoclonal antibodies (MoAbs) are a highly diversified class of proteins with major research and commercial applications such as diagnostics and therapeutics. Currently, the dominant method for producing MoAbs is through the hybridoma technique. However, this technique is slow, tedious, labor intensive, and expensive. The production of MoAbs in cultured transgenic plant cells can offer some advantages over that in the over that in the mammalian systems. The media to cultivate plant cells are well defined and inexpensive. Contamination by bacteria or fungi is easily monitored in plant tissue cultures. Furthermore, these contaminants are usually not potent pathogens to human beings. In our interdisciplinary research efforts, heavy chain monoclonal antibody (HC MAb) was inserted into Ti plasmid vector and transferred into A. tumefaciens for the transformation in tobacco cells. It was found that 76% of the transformants produced HC MAb. The presence of HC MAb in the cell membrane fraction indicated that the signal peptide was functional and efficient. The change of the HC MAb concentration during a batch culture followed a similar trend as dry cell concentration, indicating that the production of HC MAb was growth related. The long-term repeated subcultures of 11 cell lines showed that there was no obvious trend of neither the decrease nor the increase of the productivity with the repeated subcultures.

• 한국해양생명과학회지
• /
• 제3권1호
• /
• pp.1-8
• /
• 2018

Myosin is considered as the vital motor protein in vertebrates and invertebrates. Our present study was conducted to decipher the occurrence of myosin in dog fish (Squalus mitsukurii). We isolated one clone containing 979 bp cDNA sequence, which consisted of a complete coding sequence of 453 bp and a deduced amino acid sequence of 150 amino acids from the open reading frame with molecular weight, isoelectric point and aliphatic index are 16.72 Kda, 4.49 and 78.00, respectively. It contained 428 bp long 3' UTR with single potential polyadenylation signals (AATAAA). The predicted EF CA²⁺ binding domains were identified in residue 6-41, 83-118 and 133-150. A BLAST search indicates this protein exhibits a strong similarity to whale shark (Rhincodon typus) MLC3 (91% identical) and also house mouse (Mus musculus) MLC isoform 3f (81% identical). Phylogenetic analysis revealed that this protein is a MLC 3 isoform like protein. This protein also demonstrates highly conserved region with other myosin proteins. Homology modeling of S. mitsukuri was performed using crystal structure of Gallus gallus skeletal muscle myosin II based on high similarity. Reverse transcription-polymerase chain reaction (PCR), quantitative PCR results exhibits dogfish myosin protein is highly expressed in muscle tissue.

• 한국해양생명과학회지
• /
• 제8권2호
• /
• pp.186-189
• /
• 2023

Uncoupling protein 1 (UCP1) is a unique mitochondrial membranous protein expressed in brown adipose tissue (BAT) in mammals. While its expression in response to cold temperatures and adipogenic inducers is well-characterized in mammals and human infants, the molecular characterization and expression of UCP1 in fish remain unexplored. To address this gap, we analyzed UCP1 expression in response to adipogenic inducers in a fish cell line, rainbow trout gonadal cells (RTG-2), and compared it with UCP1 expression in three mammalian preadipocytes, 3T3-L1, T37i, and WT1 exposed to the Peroxisome proliferator-activated receptor gamma (PPARγ) agonists, rosiglitazone (Rosi). In mammalian preadipocytes, UCP1 protein was highly expressed by Rosi, with an induction of adipogenesis observed in a time-dependent manner. This suggests that UCP1 plays a significant role in adipogenesis in mammals. However, RTG-2 cells showed no response to adipogenic inducers and exhibited only marginal expressions of UCP1. These results imply that RTG-2 cells may lack crucial responsive mechanisms to adipogenic signals or that the adipogenic response is regulated by other mechanisms. Further studies are needed to confirm these phenomena in fish preadipocytes when an appropriate cell line is established in future research.

• 대한소아치과학회지
• /
• 제51권2호
• /
• pp.165-175
• /
• 2024

This study aimed to investigate the effects of blood contamination on the Vickers hardness and the surface morphology of premixed MTA and compare them with the effects on conventional MTA. The Vickers microhardness of Endocem MTA Premixed Regular (EP) and ProRoot MTA (PM) was assessed after immersion in fetal bovine serum (FBS) and saline. Stem cells from human exfoliated deciduous teeth (SHED) were seeded on MTA after immersion in FBS, saline, and deionized water (DW). Cell adhesion patterns and surface morphology were visualized via scanning electron microscopy (SEM). The surface microhardness of EP and PM in FBS was lower than in saline. However, short-term exposure of PM to FBS did not reduce the microhardness compared to saline. Angular crystals formed in water, while rounded crystals with more air voids appeared in FBS. Favorable SHED attachment occurred in all groups. Overall, the surface hardness of EP and PM decreased after FBS exposure, although PM was less influenced. We suggest minimizing the amount of bleeding when using MTA clinically; nevertheless, PM remains an option with more expected blood contamination than EP. In summary, exposure to FBS decreased mechanical performance but allowed cell adhesion for both MTAs, with PM being more resistant to these changes.

• IMMUNE NETWORK
• /
• 제24권1호
• /
• pp.11.1-11.18
• /
• 2024

IL-15 belongs to the common gamma chain cytokine family and has pleiotropic immunological functions. IL-15 is a homeostatic cytokine essential for the development and maintenance of NK cells and memory CD8⁺ T cells. In addition, IL-15 plays a critical role in the activation, effector functions, tissue residency, and senescence of CD8⁺ T cells. IL-15 also activates virtual memory T cells, mucosal-associated invariant T cells and γδ T cells. Recently, IL-15 has been highlighted as a major trigger of TCR-independent activation of T cells. This mechanism is involved in T cell-mediated immunopathogenesis in diverse diseases, including viral infections and chronic inflammatory diseases. Deeper understanding of IL-15-mediated T-cell responses and their underlying mechanisms could optimize therapeutic strategies to ameliorate host injury by T cell-mediated immunopathogenesis. This review highlights recent advancements in comprehending the role of IL-15 in relation to T cell responses and immunopathogenesis under various host conditions.

• Journal of Forest and Environmental Science
• /
• 제40권1호
• /
• pp.43-52
• /
• 2024

Cadmium (Cd) is non-essential heavy metal that negatively affects plant metabolism. Nitric oxide (NO) is an increasingly important molecule for plant metabolism that makes signaling. In this study, it was aimed to investigate the alleviating effect of sodium nitroprusside (SNP) application as NO donor in white poplar (Populus alba) under Cd stress conditions. SNP and without SNP treatments increased the Cd accumulation in root tissue. While photosynthetic pigments (Chl a, Chl b, Chl a+b, and carotenoid) content decreased by only Cd application, SNP+Cd application decreased the rate of photosynthetic pigments reduction. When the results of Cd and Cd+SNP applications were evaluated for mineral (Fe, Zn, Mn and Cu) uptake, it was found that the positive effect of SNP was heterogeneously affected. Depending on SNP application, it was found that malondialdehyde (MDA) amount decreased in leaf in 100 µM Cd applications while hydrogen peroxide (H₂O₂) amount decreased in 100 and 500 µM Cd applications. When antioxidant enzyme activities were examined, it was found that catalase (CAT) and ascorbate peroxidase (APX) enzyme activities increased with 100 µM SNP applications under all Cd applications. As a result, it was found that SNP application under Cd stress generally supports physiological processes positively in white poplar, suggesting that NO molecule plays important alleviating roles in plant metabolism.

• Biomolecules & Therapeutics
• /
• 제32권3호
• /
• pp.281-290
• /
• 2024

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis owing to its desmoplastic stroma. Therefore, therapeutic strategies targeting this tumor stroma should be developed. In this study, we describe the heterogeneity of cancer-associated fibroblasts (CAFs) and their diverse roles in the progression, immune evasion, and resistance to treatment of PDAC. We subclassified the spatial distribution and functional activity of CAFs to highlight their effects on prognosis and drug delivery. Extracellular matrix components such as collagen and hyaluronan are described for their roles in tumor behavior and treatment outcomes, implying their potential as therapeutic targets. We also discussed the roles of extracellular matrix (ECM) including matrix metalloproteinases and tissue inhibitors in PDAC progression. Finally, we explored the role of the adaptive and innate immune systems in shaping the PDAC microenvironment and potential therapeutic strategies, with a focus on immune cell subsets, cytokines, and immunosuppressive mechanisms. These insights provide a comprehensive understanding of PDAC and pave the way for the development of prognostic markers and therapeutic interventions.