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Development of A Material Flow Model for Predicting Nano-TiO2 Particles Removal Efficiency in a WWTP (하수처리장 내 나노 TiO2 입자 제거효율 예측을 위한 물질흐름모델 개발)

  • Ban, Min Jeong;Lee, Dong Hoon;Shin, Sangwook;Lee, Byung-Tae;Hwang, Yu Sik;Kim, Keugtae;Kang, Joo-Hyon
    • Journal of Wetlands Research
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    • v.24 no.4
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    • pp.345-353
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    • 2022
  • A wastewater treatment plant (WWTP) is a major gateway for the engineered nano-particles (ENPs) entering the water bodies. However existing studies have reported that many WWTPs exceed the No Observed Effective Concentration (NOEC) for ENPs in the effluent and thus they need to be designed or operated to more effectively control ENPs. Understanding and predicting ENPs behaviors in the unit and \the whole process of a WWTP should be the key first step to develop strategies for controlling ENPs using a WWTP. This study aims to provide a modeling tool for predicting behaviors and removal efficiencies of ENPs in a WWTP associated with process characteristics and major operating conditions. In the developed model, four unit processes for water treatment (primary clarifier, bioreactor, secondary clarifier, and tertiary treatment unit) were considered. Additionally the model simulates the sludge treatment system as a single process that integrates multiple unit processes including thickeners, digesters, and dewatering units. The simulated ENP was nano-sized TiO2, (nano-TiO2) assuming that its behavior in a WWTP is dominated by the attachment with suspendid solids (SS), while dissolution and transformation are insignificant. The attachment mechanism of nano-TiO2 to SS was incorporated into the model equations using the apparent solid-liquid partition coefficient (Kd) under the equilibrium assumption between solid and liquid phase, and a steady state condition of nano-TiO2 was assumed. Furthermore, an MS Excel-based user interface was developed to provide user-friendly environment for the nano-TiO2 removal efficiency calculations. Using the developed model, a preliminary simulation was conducted to examine how the solid retention time (SRT), a major operating variable affects the removal efficiency of nano-TiO2 particles in a WWTP.

Associations of Communication Skills, Self-Efficacy on Clinical Performance and Empathy in Trainee Doctors (전공의 의료커뮤니케이션 능력과 진료수행 자기효능감, 공감능력과의 상관관계)

  • Kim, Doehyung;Kim, Min-Jeong;Lee, Haeyoung;Kim, Hyunseuk;Kim, Youngmi;Lee, Sang-Shin
    • Korean Journal of Psychosomatic Medicine
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    • v.29 no.1
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    • pp.49-57
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    • 2021
  • Objectives : This study evaluated the medical communication skills of trainee doctors and analyzed the relationship between medical communication skills, self-efficacy on clinical performance (SECP) and empathy. Methods : A total of 106 trainee doctors from a university hospital participated. The questionnaire comprised self-evaluated medical communication skills, modified SECP and the Korean version of the Jefferson Scale of Empathy-Health Professionals version. The mean difference in medical communication skills scores according to gender, age, division (intern, internal medicine group or surgery group) and position (intern, first-/second- and third-/fourth-year residents) were analyzed. Pearson correlation coefficients were determined between medical communication skills, modified SECP and empathy. The effects of each variable on medical communication skills were verified using the structural equation model. Results : There were no statistically significant mean differences in self-evaluated medical communication skills according to gender, age, division or position. Medical communication skills had a significant positive correlation with modified SECP (r=0.782, p<0.001) and empathy (r=0.210, p=0.038). Empathy had a direct effect on modified SECP (β=0.30, p<0.01) and modified SECP had a direct effect on medical communication skills (β=0.80, p<0.001). Empathy indirectly influenced medical communication skills, mediating modified SECP (β=0.26, p<0.05). Conclusions : Medical communication skills are an important core curriculum of residency programs, as they have a direct correlation with SECP, which is needed for successful treatment. Moreover, the medical communication needs a new understanding that is out of empathy.

Automated Analyses of Ground-Penetrating Radar Images to Determine Spatial Distribution of Buried Cultural Heritage (매장 문화재 공간 분포 결정을 위한 지하투과레이더 영상 분석 자동화 기법 탐색)

  • Kwon, Moonhee;Kim, Seung-Sep
    • Economic and Environmental Geology
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    • v.55 no.5
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    • pp.551-561
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    • 2022
  • Geophysical exploration methods are very useful for generating high-resolution images of underground structures, and such methods can be applied to investigation of buried cultural properties and for determining their exact locations. In this study, image feature extraction and image segmentation methods were applied to automatically distinguish the structures of buried relics from the high-resolution ground-penetrating radar (GPR) images obtained at the center of Silla Kingdom, Gyeongju, South Korea. The major purpose for image feature extraction analyses is identifying the circular features from building remains and the linear features from ancient roads and fences. Feature extraction is implemented by applying the Canny edge detection and Hough transform algorithms. We applied the Hough transforms to the edge image resulted from the Canny algorithm in order to determine the locations the target features. However, the Hough transform requires different parameter settings for each survey sector. As for image segmentation, we applied the connected element labeling algorithm and object-based image analysis using Orfeo Toolbox (OTB) in QGIS. The connected components labeled image shows the signals associated with the target buried relics are effectively connected and labeled. However, we often find multiple labels are assigned to a single structure on the given GPR data. Object-based image analysis was conducted by using a Large-Scale Mean-Shift (LSMS) image segmentation. In this analysis, a vector layer containing pixel values for each segmented polygon was estimated first and then used to build a train-validation dataset by assigning the polygons to one class associated with the buried relics and another class for the background field. With the Random Forest Classifier, we find that the polygons on the LSMS image segmentation layer can be successfully classified into the polygons of the buried relics and those of the background. Thus, we propose that these automatic classification methods applied to the GPR images of buried cultural heritage in this study can be useful to obtain consistent analyses results for planning excavation processes.

The effects of Allomyrina dichotoma larval extract on palmitate-induced insulin resistance in skeletal muscle cells (장수풍뎅이 유충 추출물이 고지방산 처리 골격근세포의 인슐린 저항성에 미치는 영향)

  • Kim, Kyong;Sim, Mi-Seong;Kwak, Min-Kyu;Jang, Se-Eun;Oh, Yoon Sin
    • Journal of Nutrition and Health
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    • v.55 no.4
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    • pp.462-475
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    • 2022
  • Purpose: Allomyrina dichotoma larvae are one of the approved edible insects with nutritional value and various functional and medicinal properties. Previously we have demonstrated that the Allomyrina dichotoma larval extract (ADLE) ameliorates hepatic insulin resistance in high-fat diet (HFD)-induced diabetic mice through the activation of adenosine monophosphate-activated protein kinase (AMPK). This study investigated the effects of ADLE on insulin resistance in the skeletal muscle and explored mechanisms for enhancing the glucose uptake in palmitate (PAL)-treated C2C12 myotubes. Methods: To induce insulin resistance, the differentiated C2C12 myotubes were treated with PAL (0.5 mM) for 24 hours, and then treated with a 0.5 mg/ml concentration of ADLE, and the resultant effects were measured. The expression levels of glucose transporter-4 (GLUT4), AMPK, and the mitochondrial metabolism-related proteins were analyzed by western blotting. The mRNA expression levels of lipogenesis- related genes were determined by quantitative reverse-transcriptase PCR. Results: The exposure of C2C12 myotubes to 0.5 mg/ml of ADLE increased cell viability significantly compared to PAL-treated cells. ADLE upregulated the protein expression of GLUT4 and enhanced glucose uptake in the PAL-treated cells. ADLE increased the phosphorylated AMPK in both the PAL-treated C2C12 myotubes and HFD-treated skeletal muscle. The reduced expression levels of peroxisome-proliferator-activated receptor gamma co-activator-1 alpha (PGC1α) and uncoupling protein 3 (UCP3) due to the PAL and HFD treatment were reversed by the ADLE treatment. The citrate synthase activity was also significantly increased with the PAL and ADLE co-treatment. Moreover, the mRNA and protein expressions of fatty acid synthesis-related factors were reduced in the PAL and HFD-treated muscle cells, and this effect was significantly attenuated by the ADLE treatment. Conclusion: ADLE activates AMPK, which in turn induces mitochondrial metabolism and reduces fatty acid synthesis in C2C12 myotubes. Therefore, ADLE could be useful for preventing or treating insulin resistance of skeletal muscles in diabetes.

The Effects of 8-week Ketone Body Supplementation on Endurance Exercise Performance and Autophagy in the Skeletal Muscle of Mice (8주 케톤체 투여가 마우스 지구성 운동수행능력과 골격근의 자가포식에 미치는 영향)

  • Jeong-sun Ju;Min-joo Park;Dal-woo Lee;Dong-won Lee
    • Journal of Life Science
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    • v.33 no.3
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    • pp.242-251
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    • 2023
  • The purpose of this study was to investigate the effects of 8-week β-hydroxybutyrate (β-HB) administration with and without endurance exercise training on endurance exercise performance and skeletal muscle protein synthesis and degradation using a mouse model. Forty-eight male wild-type ICR mice (8 weeks old) were randomly divided into four groups: sedentary control (Sed+Con), (Sed+Con), sedentary β-HB (Sed+β-HB), exercise control (Exe+Con), and exercise β-HB (Exe+β-HB). β-HB was dissolved in PBS (150 mg/ml) and injected subcutaneously daily (250 mg/kg) for 8 weeks. Mice performed 5 days/week of a 20 min treadmill running exercise for 8 weeks. The running exercise was carried out at a speed of 10 m/min at a 10° incline for 5 min, and then the speed was increased by 1 m/min for every 1 min of the remaining 15 min. Following 8 weeks of treatments, visceral fat mass and skeletal muscle mass, blood parameters, and the markers for autophagy and protein synthesis were analyzed. The data were analyzed with one-way ANOVA (p<0.05) using the SPSS 21 program. Eight weeks of Exe+β-HB treatment significantly lowered blood lactate levels compared with the other three groups (Sed+Con, Sed+β-HB, and Exe+β-HB) Exe+β-HB) (p<0.05). Eight weeks of Exe+β-HB significantly increased maximal running time (time to exhaustion) compared with the Sed+Con and Exe+Con groups (p<0.05). Eight weeks of β-HB administration significantly decreased autophagy flux and autophagy-related proteins in the skeletal muscle of mice (p<0.05). Conversely, the combined treatment of β-HB and endurance exercise training increased protein synthesis (mTOR signaling and translation) (p<0.05). The 8-week β-HB treatment and endurance exercise training had synergistic effects on the increase in endurance performance, increase in protein synthesis, and decrease in protein degradation in the skeletal muscle of mice.

The 50th Anniversary of the UNESCO World Heritage Convention: present status and challenges (유네스코 세계유산 협약 50주년, 현재 및 과제)

  • LEE Hyunkyung ;YOO Heejun ;NAM Sumi
    • Korean Journal of Heritage: History & Science
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    • v.56 no.2
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    • pp.264-279
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    • 2023
  • The 50th anniversary of the UNESCO World Heritage Convention was in 2022. In order to reflect on the present and future of the meaning of World Heritage, this paper examines the development and changes of the UNESCO World Heritage system. After promulgating the convention in 1972, the UNESCO World Heritage system prioritized the protection of heritage sites in the world that were at risk due to armed conflicts and natural disasters to bequeath heritage to the next generation. In addition, the UNESCO World Heritage's emphasis on Outstanding Universal Value represents the particular culture of human beings formed during a certain period of time, and acts as a significant source of soft power in public diplomacy. The UNESCO World Heritage might be perceived as a shared heritage that has not only become a channel to understand various national values, but also an effective medium to convey one of UNESCO's main principles, that is, peacebuilding. However, the UNESCO World Heritage is now at the center of conflicts of heritage interpretation between many stakeholders related to invisible wars, such as cultural wars, memory wars, and history wars as the social, political, and cultural contexts concerning World Heritage have dramatically shifted with the passing of time. Paying attention to such changing contexts, this paper seeks to understand the main developments in UNESCO World Heritage's discourse concerning changes to the World Heritage Operation Guidelines and heritage experts' meetings by dividing its 50-year history into five phases. Next, this paper analyzes the main shifts in keywords related to UNESCO World Heritage through UNESDOC, which is a platform on which all UNESCO publications are available. Finally, this paper discusses three main changes of UNESCO World Heritage: 1) changes in focus in World Heritage inscriptions, 2) changes in perception of World Heritage protection, and 3) changes of view on the role of the stakeholders in World Heritage. It suggests new emerging issues regarding heritage interpretation and ethics, climate change, and human rights.

The roles of Subcontractors' Entrepreneurship on the Relationship Commitment towards the Parent Companies (수급사업자의 기업가정신이 관계몰입을 유도하는 경로)

  • Nak Hwan Choi;Cheol Seob Byeon;Yong Gyun Lee
    • Asia Marketing Journal
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    • v.13 no.1
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    • pp.51-84
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    • 2011
  • It seems essential to examine the factors that may affect relationship commitment of subcontractors to parent companies in the industrial market in Korea in an effort to construct a win-win-type cooperative network among them. Lots of studies have been focusing on the consumer goods market. Relatively few studies have been focused on industrial market. In the industrial goods market subcontractors used to sell their parts or services only to a small number of parent companies in a large quantity, resulting in decisive control of subcontractors over the quality of parent companies' finished goods. This is why relationship between subcontractors and parent companies is extremely important. From this viewpoint, this study aims to survey and analyze empirically the paths leading to relationship commitment of subcontractors toward the parent companies which are required to incite them to build up a collaborative network by means of subcontractors' entrepreneurship. For this aim, market orientation effects of entrepreneurship as well as factors of performance and trust are particularly set forth as the bases of developing hypotheses in this study in order to explore the paths from entrepreneurship to relationship commitment as follows. First, the path of entrepreneurship-market orientation-communication-trust- relationship commitment; second, the path of entrepreneurship-market orientation-performance-relationship commitment; third, the path of entrepreneurship-market orientation-transaction specific asset investment -trust-relationship commitment; and fourth, the path in which the entrepreneurship is expected to promote direct transaction specific asset investment by parent companies to induce their trust and, eventually, relationship commitment of subcontractors. The outcomes of the empirical analysis in this study may be summed up as follows: First, the conclusions of preceding studies are also supported here by the fact that the entrepreneurship of subcontractors promotes their market orientation (hypothesis 9), indicating that the entrepreneurship can facilitate collection, proliferation of and response to market informations. On the contrary, however, the assumption that the entrepreneurship of subcontractors might directly accelerate transaction specific asset investment by parent companies (hypothesis 8) is rejected. Second, although the influence of subcontractors' entrepreneurship on parent companies' investment of assets peculiar to their transactions is not affirmed, the assumption is found to be supported that subcontractors' market orientation would expedite the parent companies' investment of assets peculiar to their transactions. Moreover, it is also confirmed that parent companies' investment of assets peculiar to transactions would promote subcontractors' trust toward the parent companies (hypothesis 6), signifying that parent companies may level up their trust in subcontractors when they make great amount of efforts to invest in the assets peculiar to transactions, not behaving opportunistically, Third, the hypotheses 4 and 5 also turn out to be supported by the analysis as the former assumes that market orientation could promote communication and the latter relates that the communication between subcontractors and parent companies would prompt trust, both results in affirming that market orientation could introduce open communication to speed up sharing of information and that sharing of information by way of communication might give an impetus to trust. Fourth, the assumption that subcontractors' market orientation would expedite performance (hypothesis 3) is also proved favorably to the significant level equivalent to that of preceding studies. Fifth, same as preceding studies, it is also verified in this study that the benefit (outcomes) awarded by parent companies to subcontractors will be a direct cause exercising a positive impact upon relationship commitment(hypothesis 2) and that the trust of subcontractors toward parent companies may have affirmative influence on the relationship commitment(hypothesis 1). Overall, the first, second and third paths are identified as being supported by the hypotheses among constituent factors, while the fourth path is deemed meaningless since it is shown that the entrepreneurship exercises no effects on parent companies' investment in the assets peculiar to transactions.

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Consumer's Responses to the Persuasion Attempt of the Sports Sponsorship: The Case of Guangzhou Asian Games (스폰서십의 설득의도성에 대한 소비자 반응: 광저우 아시안 게임을 바탕으로)

  • Lim, Myung Suh;Kim, Hae Ryong;Lee, Moonkyu
    • Asia Marketing Journal
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    • v.13 no.2
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    • pp.71-97
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    • 2011
  • Over the last twenty years, sponsorship has been used very widely as an important marketing tool that enhances corporate image. Since it has proven to be effective in creating positive perceptions of the company, many marketers have sponsored a variety of consumer-related activities. However, sponsorship has also been criticized as it can be related to ambush marketing and excessive commercialism which trigger negative consumer responses. Unlike the existing study on the sponsorship marketing, this study intends to investigate its negative effects. The study was conducted based on the persuasion knowledge model which was proposed by Fristed and Wright (1994) and investigated consumer responses to ulterior motive of sponsorship marketing. According to the persuasion knowledge model, consumers activate their persuasion knowledge to see the agent's commercial motive; there are several antecedents to the persuasion knowledge activation such as the source familiarity, the marketer's effort and the appropriateness of persuasion. Also, existing studies have pointed out the sponsor-event fit and the sponsor's integrity as crucial factors which influence consumer attitude. By taking a survey of people who watched the 2010 Guangzhou Asian Games, we tried to examine how the sponsor familiarity and the sponsor-event fit as pre-existing variables which have been formed based on the prior consumer knowledges/memories as well as the sponsor effort and the sponsor integrity as situational variables activated based on the specific persuasion episode influenced persuasion knowledge. We also tried to test the potential moderating role of sponsorship type (i.e., official sponsorship versus marketing focused) on the causal path from the persuasion knowledge and the consumer attitude from the perspective of the appropriateness of persuasion. The results show that the sponsor familiarity, the sponsor-event fit, and the marketer's effort have significant effects on the persuasion knowledge activation, and the sponsorship type has moderating role in the sponsorship effectiveness. The theoretical and practical implications of the results are discussed.

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A Study on Consumers' Intention to Continue Use of Unmanned Stores in the Non-face-to-face Era : Focusing on the Moderating Effect of COVID-19 Social Risk (비대면시대 소비자의 무인점포 지속적이용의도에 관한 연구: COVID-19 사회적 위험의 조절효과를 중심으로)

  • Oh, Jong-chul
    • Journal of Venture Innovation
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    • v.3 no.2
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    • pp.1-21
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    • 2020
  • Recently, the emergence of new technologies caused by the Fourth Industrial Revolution caused a great change not only in the overall society but also in the retail industry. In the retail industry, unmanned stores based on new technologies have emerged, changing the consumption behavior of consumers. In particular, the global pandemic caused by COVID-19, which appeared in December 2019, raised social risks, and as a result of this, the beginning of the non-face-to-face era, interest in unmanned stores is increasing. In this study, the effects of benefits factors (perceived usefulness, perceived economics, perceived enjoyment, relative advantages) and sacrifice factors (perceived risk, technicality) perceived by unmanned store users on continuous use intention through perceived value. In addition, it is a study to test through empirical analysis what role the social risk from COVID-19 plays in the process of consumption through unmanned stores. The purpose of this study is to provide strategic implications for the activation of unmanned stores in the non-face-to-face era. In this study, a total of 293 copies of data were collected for users of unmanned stores for hypothesis testing. In addition, the collected data was analyzed using SPSS 21.0 and AMOS 21.0 statistical programs. The results of the study are summarized as follows. First, it was found that the perceived benefits (perceived usefulness, perceived economics, perceived playfulness, and relative advantages) of unmanned stores all had a significant positive effect on perceived value. Second, it was found that all perceived sacrifices (perceived risk, technicality) of unmanned stores had a significant negative effect on perceived value. Third, it was found that the perceived value of unmanned stores had a significant positive effect on the intention to continue use. Finally, the social risk from COVID-19 has been shown to play a moderating role when the perceived sacrifice of unmanned stores affects the perceived value.

L-AHG-mediated Suppression of M1 Polarization and Pro-inflammatory Signaling Pathways in LPS-stimulated RAW264.7 Macrophages (LPS에 의해 자극된 RAW264.7 대식세포에서 L-AHG에 의한 M1 분극화 및 친염증 신호 경로의 억제)

  • Won Young Jang;Shin Young Park;Ki Youn Kim;Do Youn Jun;Young-Seuk Bae;Young Ho Kim
    • Journal of Life Science
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    • v.34 no.7
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    • pp.443-452
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    • 2024
  • This study aimed to examine the influence of 3,6-anhydroxygalactose (L-AHG) on the pro-inflammatory M1 polarization and pro-inflammatory responses observed in the RAW264.7 mouse macrophage cell line following stimulation with lipopolysaccharides (LPS). L-AHG exhibited a significant and dose-dependent inhibition of inducible nitric oxide synthase (iNOS) expression, a hallmark of M1 polarization, and subsequent NO production in LPS-stimulated RAW264.7 cells. Furthermore, the LPS-induced upregulation of cyclooxygenase-2 (COX-2), which drives the production of prostaglandin E2, an inflammatory mediator, was also inhibited by L-AHG. L-AHG did not affect the LPS-triggered Toll-like receptor 4 (TLR4)-mediated pro-inflammatory signaling pathway, which culminated in the activation of transforming growth factor-β-activated kinase 1 (TAK1). However, it was observed to inhibit the generation of reactive oxugen species (ROS) in a dose-dependent manner, as well as the TAK1-driven activation of JNK and p38 MAPK. Given that the active p38 MAPK is known to contribute to the assembly of active nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which catalyzes the intracellular generation of pro-inflammatory ROS in LPS-stimulated macrophages, the dose-dependent reduction in the LPS-induced ROS generation by L-AHG may be mainly due to the prevention of TAK1-driven activation of p38 MAPK. Together, these results demonstrate that the L-AHG-mediated inhibition of the TAK1-JNK/p38 MAPK activation phase of the pro-inflammatory signaling pathway in LPS-stimulated RAW264.7 cells by L-AHG represents a promising mechanism for suppressing M1 polarization and pro-inflammatory responses in macrophages.