In this study, laser-induced graphene oxide (LIGO) was synthesized through a facile liquid-based process involving the introduction of deionized (DI) water onto polyimide (PI) film and subsequent direct laser irradiation using a CO2 laser (λ = 10.6 μm). The synthesized LIGO was then evaluated as a sensing material for monitoring changes in humidity levels. The synthesis conditions were optimized by precisely controlling the laser scribing speed, leading to the synthesis of LIGO with different structural characteristics and varying oxygen contents. The increased number of oxygen-containing functional groups contributed to the hydrophilic properties of LIGO, resulting in a superior humidity sensing capabilities compared with laser-induced graphene (LIG). The LIGO-based sensors outperformed LIG-based sensors, demonstrating approximately tenfold higher sensing responsivity when detecting changes at each humidity level, along with 1.25 to 1.75 times faster response/recovery times, making LIGO-based sensors more promising for humidity-monitoring applications. This study demonstrated laser ablation in a renewable and natural precursor as an eco-friendly and energy-efficient approach to directly synthesize LIGO with controllable oxidation levels.
In order to predict the process window of laser powder bed fusion (LPBF) for printing metallic components, the calculation of volumetric energy density (VED) has been widely calculated for controlling process parameters. However, because it is assumed that the process parameters contribute equally to heat input, the VED still has limitation for predicting the process window of LPBF-processed materials. In this study, an explainable machine learning (xML) approach was adopted to predict and understand the contribution of each process parameter to defect evolution in Ti alloys in the LPBF process. Various ML models were trained, and the Shapley additive explanation method was adopted to quantify the importance of each process parameter. This study can offer effective guidelines for fine-tuning process parameters to fabricate high-quality products using LPBF.
Haemaphysalis longicornis는 사람과 동물에게 여러 심각한 병원체를 전달하는 주요 매개체로, 한반도에 널리 분포하고 있다. H. longicornis는 Rickettsia spp., Borrelia spp., Francisella spp., Coxiella spp., 그리고 중증열성혈소판 감소증후군 바이러스 (SFTS virus) 등을 매개하는 것으로 알려져 있다. 국내에 서식하는 H. longicornis의 미생물 군집과 관련된 연구는 많이 진행되지 않은 것으로 확인되었다. 이 연구는 한반도 내 다양한 지역에서 채집된 H. longicornis의 미생물군집 다양성을 지역별, 성장 단계 및 성별에 따라 분석하였다. 2019년 6월부터 7월까지 질병관리청 권역별기후변화매개체감시거점센터 16개 지역에서 채집한 H. longicornis의 16S rRNA 유전자 V3-V4 영역을 PCR로 증폭 후 Illumina MiSeq 플랫폼으로 시퀀싱하였다. Qiime2를 활용한 미생물 다양성 분석을 통해 총 46개의 샘플에서 1,754,418개의 non-chimeric reads를 얻었으며, 평균 126개 의 operating taxonmic unit (OTU) 을 식별하여 총 1,398개의 OTU를 확인하였다. 대부분의 지역에서 Coxiella spp.가 우점종으로 나타났으며, 특히 Coxiella endosymbiont는 가장 높은 우점도를 보이며, Coxiella burnetii와 계통 발생 학적으로 유사한 것으로 확인되었다. 이 연구를 통해 분석된 결과는 각 지역의 H. longicornis 미생물군집 데이터 베이스 구축에 활용되었으며, 이를 통해 지역별 미생물군집의 특이성을 식별할 수 있게 하였다. 이는 한반도의 H. longicornis에 의한 질병 전파 연구와 이를 통한 공중보건 개선에 기여할 것으로 기대된다.
Recently, it is demonstrate that the invertebrates have a immune memory, called Immune priming (IP). It was partially studied that the IP is mainly regulated by epigenetic modification. Here, to understand the IP on antimicrobial peptides (AMPs) production, we investigated larval mortality and time-dependent expression patterns of AMP genes in T. molitor larvae challenged with E. coli (two-times injection with a one-month interval). Interestingly, the results indicate that the higher and faster expression levels of most AMP genes were detected compared to the non-primed T. molitor larvae. Our results may used to improve the understanding of mechanisms of invertebrate immune memory.
Pellino, a highly conserved E3 ubiquitin ligase, is known to mediate ubiquitination of phosphorylated Interleukin-1 receptor-related kinase (IRAK) homologs in Toll signaling pathway. To understand the immunological function of TmPellino, we screened the knockdown efficiency of TmPellino by injecting TmPellino-specific dsRNA into T. molitor larvae. Subsequently, we investigated the larval mortality and the tissue-specific expression patterns of antimicrobial peptide (AMP) genes against microbial challenges. Interestingly, the results indicate that the expression of many AMP genes was upregulated in the Malpighian tubules of TmPellino-silenced T. molitor larvae. This study may provide basic information to understand how Tmpellino regulates AMPs production in T. molitor.
Tumor necrosis factor receptor-associated factor (TRAF) is known to regulate antimicrobial peptides (AMPs) production in mammals. Here, to understand the immunological function of TmTRAF against microbial challenge, the induction patterns of TmTRAF against microbial infection was investigated by qRT-PCR in the whole-body and tissue of young larvae. In addition, the effects of TmTRAF RNAi on larval mortality and expression of 15 AMP genes in response to microbial infection were investigated. Our studies may help to understand the basic role of AMP production.
Tube, an intracellular protein of the Toll-pathway, forms a complex with Pelle and MyD88, and regulates a signal transduction to activate NF-κB in Drosophila. To understand the antimicrobial function of TmTube, the induction patterns of TmTube were investigated at 3, 6, 9, 12, and 24 h-post injection of pathogens into 10th to 12th instar larvae. In addition, we investigated the effects of TmTube RNAi on larval mortality and tissue specific AMP expression in response to microbial challenge. Our results will provide a basic information to elucidate the immunological function of TmTube
In insects, the glutathione S-transferase is initiated in both the detoxification process and the protection of cellular membranes against oxidative damage. In this study, we identified the open reading frame (ORF) sequence of GST-iso1 and 2 from Tenebrio molitor (TmGST-iso1 and 2). To investigate the expression patterrns of TmGST-iso1 and 2 in response to herbicide, 0.06, 0.6, and 6 ㎍/㎕ of butachlor (FarmHannong, Seoul, South Korea) was challenged into T. molitor larvae, resulting that the TmGST-iso1 were highly induced at 3 and 24 h-post injection. Whereas, the highest expression of TmGST-iso2 was detected at 24 h after treatment. This study may contribute to basic information about the detoxifying activities of T. molitor.
Pelle, a serine/threonine kinase, is an intracellular component of the Toll pathway and is involved in antimicrobial peptides (AMPs) production due to pathogenic infection. It is known that the Pelle phosphorylates Cactus and activates the NF-κB signaling pathway in Drosophila, but it is not studied in Tenebrio molitor. In this study we investigated the tissue-specific expression patterns of the Pelle following pathogenic infection at 3, 6, 9, 12, and 24 hours. Additionally, larval mortality and AMP expression against microbial injection were investigated in dsPelle-treated T. molitor larvae. Our results may help to understand the antimicrobial function of TmPelle.
It is well known that the JNK pathway regulates AMP production against pathogenic infection in both vertebrates and invertebrates. Tenebrio molitor hep (Tmhep) is an homolog of MAP kinase kinase in mammals. Here, we investigate the immunological function of Tmhep in responses in microbial infection using RNA interference technology. The results showed that silencing of Tmhep increased the larval mortality against microbial challenge, as well as reduced AMP production compared to the control group (dsEGFP-treated group). Conclusively, Tmhep plays an critical role in antimicrobial defense in T. molitor larvae.
Tropilaelaps mercedesae Anderson and Morgan, 2007 (Acari: Laelapidae) is a serious ectoparasite of the brood of several honey bee species. Among the four recognized species of Tropilaelaps, Korean population was renamed as T. mercedesae from T. clareae on the basis of morphological evidences and genetic data. In this study, we report the complete mitochondrial genome (mitogenome) sequence of T. mercedesae. The 15,119-bp long mitogenome has an identical gene arrangement to that of Chinese sample reported previously. Comparison of two geographic samples showed COII, ND5, ND4, ND6, CytB, and ND1 to have higher number of variable sites than COI, which is often used for population-level study, suggesting these genes to have potential usefulness for population genetic study. The mitogenome sequence of T. mercedesae from Korea could be useful for species identification for geographic samples, trace of the origin of local populations, and illustration of evolutionary distinction among Tropilaelaps species either using part of or whole genome.
Yellow flower thrips (WFT), Frankliniella occidentalis is mainly controlled using chemical control methods. But the continuous use of chemical pesticides in greenhouse may contribute to development of insecticide resistance. Therefore, in this study, we evaluated the insecticidal activity of eleven insecticides against the WFT occurring in greenhouse pepper cultivation in the Gyeonggi province. The results showed no resistance in treatments with emamectin benzoate, fluxametamide, and flometoquin while high levels of resistance were recorded in treatments with acrinathrin, acetamiprid, and dinotefuran. The Anseong and Yeoju population was more resistant against spinetoram and chlorfluazuron, respectively, than populations from other regions.
Bangladeshi medicinal plants (BMP) have a history of traditional use in treating chronic inflammatory diseases, but a BMP bark’s antioxidant and anti-inflammatory effects remain largely unexplored. This study assessed methanolic extracts’ antioxidant and anti-inflammatory properties from the bark of 15 medicinal plant species native to Bangladesh. The methanol extracts of BMP bark were evaluated for their total antioxidant activity and ability to counteract inflammation induced by lipopolysaccharide (LPS) in RAW 264.7 macrophages. Among the 15 bark extracts from BMP, Albizia odoratissima (A. odoratissima), Engelhardia spicata (E. spicata), and Shorea robusta (S. robusta) showed the highest total phenolic contents and total antioxidant capacity by effectively scavenging free radicals. In particular, these three bark extracts significantly reduced the mRNA expression of LPS-induced inflammatory cytokines and enzymes inducible by inflammation in macrophages. Also, the mRNA expression of NADPH oxidase 2 was significantly suppressed by the three bark extracts in LPS-induced RAW 264.7 macrophages. These results suggest that out of the 15 bark extracts obtained from medicinal plants in Bangladesh, the extracts from A. odoratissima, E. spicata, and S. robusta exhibit substantial total antioxidant capacity by efficiently scavenging free radicals and also inhibit LPS-induced inflammation in macrophages.
When the parent radionuclide decays, the progeny radionuclide is produced. Accordingly, the dose contribution of the progeny radionuclide should be considered when assessing dose. For this purpose, European Commission (EC) and International Atomic Energy Agency (IAEA) provide weighting factors for dose coefficient. However, these weighting factors have a limitation that does not reflect the latest nuclide data. Therefore, in this study, we analyzed the EC and IAEA methodology for derivation of weighting factor and used the latest nuclide data from ICRP 107 to derive weighting factors for dose coefficient. Weighting factor calculation is carried out through 1) selection of nuclide, 2) setting of evaluation period, and 3) derivation based on ICRP 107 radionuclide data. Firstly, in order to derive the weighting factor, we need to select the radionuclides whose dose contribution should be considered. If the half-life of progeny radionuclides sufficiently short compared to the parent radionuclide to achieve radioactive equilibrium, or if the dose coefficient is greater of similar to that of the parent radionuclide and cannot be ignored, the dose contribution of the progeny radionuclide should be considered. In order not to underestimate the dose contribution of progeny radionuclides, the weighting factors for the progeny nuclides are taken as the maximum activity ratio that the respective progeny radionuclides will reach during a time span of 100 years. Finally, the weighting factor can be derived by considering the radioactivity ratio and branch fraction. In order to calculate the weighting factor, decay data such as the half-life of the radionuclide, decay chain, and branch fraction are required. In this study, radionuclide data from ICRP 107 was used. As a result of the evaluation, for most radionuclides, the weighting factors were derived similarly to the existing EC and IAEA weighting factors. However, for some nuclides, the weighting factors were significantly different from EC and IAEA. This is judged to be a difference in the half-life and branch fraction of the radionuclide. For example, in the case of 95Zr, the weighting factor for 95mNb showed a 35.8% difference between this study and previous study. For ICRP 38, when 95Zr decays, the branch fraction for 95mNb is 6.98×10-3. In contrast, for ICRP 107, the branch fraction is 1.08×10-2, a difference of 54.7%. Therefore, the weighting factor for the dose coefficient based on ICRP 107 data may differ from existing studies depending on the half-life and decay information of the nuclide. This suggests the need for a weighting factor based on the latest nuclide data. The results of this study can be used as a basis for the consideration of dose contributions for progeny radionuclides in various dose assessments.
The demand for transportation is increasing due to the continuous generation of radioactive wastes. Especially, considering the geographical characteristics of Korea and the location characteristics of nuclear facilities, the demand for maritime transportation is expected to increase. If a sinking accident happens during maritime transportation, radioactive materials can be released into the ocean from radioactive waste transportation containers. Radioactive materials can spread through the ocean currents and have radiological effects on humans. The effect on humans is proportional to the concentration of radioactive materials in the ocean compartment. In order to calculate the concentration of radioactive materials that constantly flow along the ocean current, it is necessary to divide the wide ocean into appropriate compartments and express the transfer processes of radioactive materials between the compartments. Accordingly, this study analyzed various ocean transfer evaluation methodologies of overseas maritime transportation risk codes. MARINRAD, POSEIDON, and LAMER codes were selected to analyze the maritime transfer evaluation methodology. MARINRAD divided the ocean into two types of compartments that water and sediment compartments. And it was assumed that radionuclides are transfered from water to water or from water to sediment. Advection, diffusion, and sedimentation were established as transfer process for radionuclides between compartments. MARINRAD use transfer parameters to evaluate transer processes by advection, diffusion, and sedimentation. Transfer parameters were affected by flow rate, sedimentation rate, sediment porosity, and etc. POSEIDON also divided the ocean into two types that water and sediment compartment, each compartments was detaily divided into three vertical sub-compartment. Advection, diffusion, resuspension, sedimentation, and bioturbation were established as transport processes for radionuclides between compartments. POSEIDON also used transfer parameters for evaluating advection, diffusion, resuspension, sedimentation, and bioturbation. Transfer parameters were affected by suspended sediment rates, sedimentation rates, vertical diffusion coefficients, bioturbation factors, porosity, and etc. LAMER only considered the water compartment. It divided the water compartment into vertical detailed compartments. Diffusion, advection and sedimentation were established as the nuclide transfer processes between the compartments. To evaluated the transfer processes of nuclides for diffusion and advection, LAMER calculated the probability with generating random position vectors for radionuclides’ locations rather than deterministic methods such as MARINRAD’s transfer parameters or POSEIDON’s transfer rates to evaluate transfer processes. The results of this study can be used as a basis for developing radioactive materials’ ocean transfer evaluation model.
As the demand for nuclear power increases as a means to achieve carbon neutrality, concerns about nuclear proliferation have also grown. Consequently, significant researches have conducted to enhance nuclear non-proliferation resistance. Among these research, nuclear material attractiveness is a methodology used to evaluate how appealing a particular material is for potential use in nuclear weapons, based on the characteristics of that material. Existing nuclear material attractiveness assessments focused on materials like U, Pu, and TRU, which could be directly used in the production of nuclear weapons. However, these assessments did not consider how the properties of nuclear materials change throughout the nuclear fuel cycle, with each facility process. This study assumed a scenario of the nuclear fuel cycle of graphite reduction reactors and analyzed including enrichment facilities and PUREX. This study used the FOM (Figure-Of-Merit) method developed by LANL (Los Alamos National Laboratory) for evaluating the nuclear material attractiveness. The FOM formula consists of three parameters such as critical mass, heat content, and dose The critical mass of targe materials and the dose evaluation were conducted using the Monte Carlo N-Particle code. The heat content was calculated using the ORIGEN code embedded in the Scale code. In particular, if U-238 is dominant in the facility’s materials, such as mining and refining facilities, and critical mass evaluation is unpractical. Therefore, 1SQ (Significant Quantity) of that uranium was assumed as the critical mass value for the FOM evaluation, even though 1SQ is not identical to the critical mass As a result of this study, the attractiveness of Pu produced by PUREX among all nuclear fuel cycle facilities was 2.7616, which was the most attractive to be diverted to nuclear weapons. Through this study, it was shown that the proliferation risk of the nuclear facilities in the nuclear fuel cycle and risk of diversion among those facilities.
Bombyx mandarina (Lepidoptera: Bombycidae), the presumed ancestor of B. mori, has long been a subject of study to illustrate the geographic relationships in connection with origin of B. mori. We report 97 mitochondrial genome (mitogenome) sequences of B. mandarina collected from Korea and Japan. Phylogenetic and population genetic analyses showed that all individuals of B. mandarina collected in Korean localities formed a strong group together with all individuals originated from northern China (mainly north of the Qinling-Huaihe line) and some of southern China. This group was placed as the sister group to B. mori strians suggesting that this group had been served as an immediate progenitor for B. mori.