• Title/Summary/Keyword: induced current

Search Result 2,712, Processing Time 0.03 seconds

Essential Guidelines for Manufacturing and Application of Organoids

  • Sun-Ju Ahn;Sungin Lee;Dayeon Kwon;Sejeong Oh;Chihye Park;Sooyeon Jeon;Jin Hee Lee;Tae Sung Kim;Il Ung Oh
    • International Journal of Stem Cells
    • /
    • v.17 no.2
    • /
    • pp.102-112
    • /
    • 2024
  • An organoid is a self-organized three-dimensional structure derived from stem cells that mimics the structure, cell composition, and functional characteristics of specific organs and tissues and is used for evaluating the safety and effectiveness of drugs and the toxicity of industrial chemicals. Organoid technology is a new methodology that could replace testing on animals testing and accelerate development of precision and regenerative medicine. However, large variations in production can occur between laboratories with low reproducibility of the production process and no internationally agreed standards for quality evaluation factors at endpoints. To overcome these barriers that hinder the regulatory acceptance and commercialization of organoids, Korea established the Organoid Standards Initiative in September 2023 with various stakeholders, including industry, academia, regulatory agencies, and standard development experts, through public and private partnerships. This developed general guidelines for organoid manufacturing and quality evaluation and for quality evaluation guidelines for organoid-specific manufacturing for the liver, intestines, and heart through extensive evidence analysis and consensus among experts. This report is based on the common standard guideline v1.0, which is a general organoid manufacturing and quality evaluation to promote the practical use of organoids. This guideline does not focus on specific organoids or specific contexts of use but provides guidance to organoid makers and users on materials, procedures, and essential quality assessment methods at end points that are essential for organoid production applicable at the current technology level.

Improvement of transmission-line-based fault locating for typical traveling-wave accelerator with constant-gradient structures

  • T.N. Hu;Y.F. Zeng;K. Peng;H. Hu;H.M. Wang;K.F. Liu
    • Nuclear Engineering and Technology
    • /
    • v.56 no.6
    • /
    • pp.2011-2018
    • /
    • 2024
  • Since RF breakdown is one of the primary limitations to improving the performances of RF accelerators, extensive efforts have been dedicated to locating the breakdowns. However, most existing methods rely on specialized techniques, resulting in high financial burdens. Although the method based on transient response of transmission line (TL) is suitable for facilities with sporadic recoverable breakdowns, practical operations are susceptible to notable errors. This study revisits the fundamental theories of lossless TL and investigates the wave process to understand the characteristics of the reversed pulse induced by the breakdowns. By utilizing steadystate response of the TL and employing phasor method, we derive analytical formulas to determine the exact location of breakdowns within the faulty cell for constant-gradient TW accelerator. Furthermore, the derived formulas demonstrate their independence from RF phase, thereby distinguishing them from traditional phasebased methods. Additionally, experimental validations are conducted at the HUST injector, and the results confirm the consistency of the analysis. Thus, the proposed method represents a promising improvement over the TL-based approaches and serves as a valuable complement to current techniques. Importantly, this method demonstrates particular advantages for constructed TW accelerators seeking to achieve a balance among high performance, low costs, and compact layouts.

Cancer cell-specific anticancer effects of Coptis chinensis on gefitinib-resistant lung cancer cells are mediated through the suppression of Mcl-1 and Bcl-2

  • JAE HWAN KIM;EUN SUN KO;DASOM KIM;SEONG-HEE PARK;EUN-JUNG KIM;JINKYUNG RHO;HYEMIN SEO;MIN JUNG KIM;WOONG MO YANG;IN JIN HA;MYUNG-JIN PARK;JI-YUN LEE
    • International Journal of Oncology
    • /
    • v.56 no.6
    • /
    • pp.1540-1550
    • /
    • 2020
  • The epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), gefitinib, is an effective therapeutic drug used in the treatment of non-small cell lung cancers (NSCLCs) harboring EGFR mutations. However, acquired resistance significantly limits the efficacy of EGFR-TKIs and consequently, the current chemotherapeutic strategies for NSCLCs. It is, therefore, necessary to overcome this resistance. In the present study, the anticancer potential of natural extracts of Coptis chinensis (ECC) against gefitinib-resistant (GR) NSCLC cells were investigated in vitro and in vivo. ECC inhibited the viability, migration and invasion, and effectively induced the apoptosis of GR cells. These effects were associated with the suppression of EGFR/AKT signaling and the expression of anti-apoptotic proteins, Mcl-1 and Bcl-2, which were overexpressed in GR NSCLC cells. Combination treatment with ECC and gefitinib enhanced the sensitivity of GR cells to gefitinib in vitro, but not in vivo. However, ECC increased the survival of individual zebrafish without affecting the anticancer effect to cancer cells in vivo, which indicated a specific cytotoxic effect of ECC on cancer cells, but not on normal cells; this is an important property for the development of novel anticancer drugs. On the whole, the findings of the present study indicate the potential of ECC for use in the treatment of NSCLC, particularly in combination with EGFR-TKI therapy, in EGFR-TKI-resistant cancers.

Influence of a peptidoglycan-enriched diet on growth performance, feed utilization and immune response in striped catfish (Pangasianodon hypophthalmus)

  • Thi Mai Nguyen;Thanh Huong Vu Thi;Sang Vu Van;Tran Vi Hich;Hoang Vu Le
    • Fisheries and Aquatic Sciences
    • /
    • v.27 no.9
    • /
    • pp.572-579
    • /
    • 2024
  • Peptidoglycan is considered a type of prebiotic or immunostimulant. However, the utilization of these substances in aquaculture remains limited, with no reported results in striped catfish. The current study aimed to investigate the effects of dietary supplementation of peptidoglycan on the growth performance and immune status of striped catfish. Fish were fed on diets supplemented with various concentrations of peptidoglycan at 0, 2.5, 5, and 10 g/kg of feed, named to PL0, PL2.5, PL5, and PL10 treatments at 4% of fish weight during 4 weeks. Blood samples were collected after 2 and 4 weeks of experiment (T2 and T4) for hematological indices and immune analyses, including lysozyme and peroxidase activities. Results demonstrated that no significant differences were found in fish growth, survival rate, and intestinal indices. The improvements in feed conversion and protein efficiency ratios were observed in PL2.5-fed fish compared to the control. Peroxidase activity in PL10 group was higher than PL0 at T4 while the highest value of lysozyme activity was recorded in fish fed PL10 at T2. In conclusion, dietary supplementation of peptidoglycan at 2.5 g per kg of diet induced a beneficial effect on feed utilization, while positive influences on immune parameters were recorded in fish fed on a diet added peptidoglycan at 10 g/kg feed.

On the Use of the Primary Breakup Model with Integration of Internal-nozzle Turbulence Impact (노즐내 난류유동 효과를 고려한 액주 분열 모델의 타당성 연구)

  • Sayop Kim;Taehoon Han;Daesik Kim
    • Journal of ILASS-Korea
    • /
    • v.29 no.3
    • /
    • pp.105-111
    • /
    • 2024
  • Although the classic Kelvin-Helmholtz model of aerodynamically driven jet breakup(primary breakup) has been widely employed in engine CFD codes for the last three decades, the model is not generally predictive. This lack of predictive capability points to the likelihood of an incorrect physical basis for the model formulation. As such, there have been more recent spray-model development efforts that incorporate additional sources of jet instability and breakup, including nozzle-generated turbulence and cavitation but predictive capabilities have remained elusive. Meanwhile, it should be noted that modern combustors increasingly operate under low-temperature combustion(LTC) conditions, where ambient densities and aerodynamic forces are much lower than under classical operating conditions. Therefore, further consideration of physical model formulation is needed. The previous literature introduced a new primary atomization modeling approach premised on experimental measurements by the Faeth group, which demonstrate that breakup is governed by nozzle-generated turbulence under low ambient density conditions. In this new modeling approach, termed the KH-Faeth model, two different primary breakup models are combined to allow the hybrid breakup modeling approach, i.e. Kelvin- Helmholtz instability breakup mechanism and turbulence-induced breakup are competed via dominant breakup rate evaluation. In the current work, we implement this hybrid KH-Faeth model within the open-source CFD framework OpenFOAM and validate the model against detailed drop sizing measurements stemming from collaborative experiments between Georgia Tech and Argonne National Laboratory.

Anticancer effect of XAV939 is observed by inhibiting lactose dehydrogenase A in a 3-dimensional culture of colorectal cancer cells

  • Dahee Kim;Byumseok Koh;Kwang Rok Kim;Ki Young Kim;Won Hoon Jung;Hi Youn Kim;Sungsub Kim;Sang Dal Rhee
    • Oncology Letters
    • /
    • v.18 no.5
    • /
    • pp.4858-4864
    • /
    • 2019
  • XAV939, a tankyrase inhibitor, exerts an anticancer effect in 3-dimensional (3D) cultured SW480 cells, however this is not exhibited in 2-dimensional (2D) cultured SW480 cells. In the current study, XAV939 induced a 3.7-fold increase in cellular apoptosis in 3D culture but not in the 2D culture. However, no significant changes were indicated in cell cycle distribution in the 2D or 3D culture. Based on the observation that protein expression, which was associated with the glycolytic pathway, was increased in the 3D culture, the effect of XAV939 on the patterns of glycolytic protein expression was assessed. XAV939 was revealed to decrease lactose dehydrogenase A (LDHA) expression in 3D cultured SW480 cells, but only exerted a small effect in the 2D culture. The coadministration of XAV939 with the LDHA inhibitor FX11 decreased proliferation in 3D cultured SW480 cells compared with the single administration of FX11, while there was no additive effect in the 2D culture. The lactate assay also indicated that XAV939 decreased lactate secretion in the 3D cell culture but not in the 2D culture. These results suggest that XAV939 exerts an anticancer effect through inhibition of LDHA in the 3D culture.

Cell Death Inhibition Effect of Antioxidant Activity by 630 and 850 nm LEDs in RAW264.7 Cells

  • Hee Eun Kim;Eun Young Kim;Jin Chul Ahn;Sang Joon Mo
    • Current Optics and Photonics
    • /
    • v.8 no.5
    • /
    • pp.441-455
    • /
    • 2024
  • This study objective was to evaluate the effects and mechanisms of low-level laser therapy in H2O2-induced cell death in mouse macrophage RAW264.7 cell. After irradiation with 630 and 850 nm wavelength diode lasers with an intensity of 10 mW/cm2 in RAW264.7 cells treated with 0.7 Mm H2O2, the effects and mechanisms of the two wavelengths on cell death inhibition were evaluated using MTT assay, ROS staining, TUNEL assay, flow cytometry analysis, and Western blot analysis. As a result, 630 or 850 nm light-emitting diodes (LED) were irradiated for 10 or 40 minutes to increase cell viability with H2O2 by about 1.7- or 1.6-fold, respectively. In addition, irradiation with two LEDs showed significant ROS scavenging effects, and TUNEL-positive cells were significantly reduced by 45.7% (630 nm) and 37.8% (850 nm) compared to cells treated with H2O2 alone. The Bax/Bcl-2 ratio of cells irradiated with both LEDs was significantly lower than that of cells treated with H2O2 only, and the expression of procaspase-3 and cleaved PARP was also significantly expressed in the direction of suppressing cell death. In conclusion, ROS scavenging activity by both LEDs irradiation leads to the expression of cell death pathway proteins in the direction of inhibiting cell death.

Feedback Processes Modulating the Sensitivity of Atlantic Thermohaline Circulation to Freshwater Forcing Timescales

  • Hyo-Jeong Kim;Soon-Il An;Soong-Ki Kim;Jae-Heung Park
    • Journal of Climate Change Research
    • /
    • v.34 no.12
    • /
    • pp.5081-5092
    • /
    • 2021
  • Paleoproxy records indicate that abrupt changes in thermohaline circulation (THC) were induced by rapid meltwater discharge from retreating ice sheets. Such abrupt changes in the THC have been understood as a hysteresis behavior of a nonlinear system. Previous studies, however, primarily focused on a near-static hysteresis under fixed or slowly varying freshwater forcing (FWF), reflecting the equilibrated response of the THC. This study aims to improve the current understanding of transient THC responses under rapidly varying forcing and their dependency on forcing time scales. The results simulated by an Earth system model suggest that the bifurcation is delayed as the forcing time scale is shorter, causing the Atlantic meridional overturning circulation collapse and recovery to occur at higher and lower FWF values, respectively. The delayed shutdown/recovery occurs because bifurcation is determined not by the FWF value at the time but by the total amount of freshwater remaining over the THC convection region. The remaining freshwater amount is primarily determined by the forcing accumulation (i.e., time-integrated FWF), which is modulated by the freshwater/salt advection by ocean circulations and freshwater flux by the atmospheric hydrological cycle. In general, the latter is overwhelmed by the former. When the forced freshwater amount is the same, the modulation effect is stronger under slowly varying forcing because more time is provided for the feedback processes.

Comparative Study of the Protective Effects of Citral, Thymoquinone, and Silymarin on Methotrexate-induced Cardiotoxicity in Rats

  • Barzan Behdokht;Noorbakhsh Mohammad Foad;Nazifi Saeed;Nasrollah Ahmadi;Amani Sakineh
    • Journal of Pharmacopuncture
    • /
    • v.27 no.3
    • /
    • pp.245-252
    • /
    • 2024
  • Objectives: Methotrexate (MTX), an immunosuppressant and anti-cancer medication, can harm the heart. The goal of the current investigation was to assess the cardiotoxicity caused by MTX and the potential cardioprotective properties of silymarin, citral, and thymoquinone as antioxidants. Methods: Forty-eight rats were divided into six groups, which included control, MTX, cosolvent, citral, thymoquinone, and silymarin groups. At the end of the study, the rats were anesthetized (ketamine and xylazine) and killed using CO2. Their blood samples were collected to measure the enzymatic activities of creatine kinase-myoglobin binding (CK-MB), creatine phosphokinase (CPK), and lactate dehydrogenase (LDH). Also, the heart tissue was sampled to determine the antioxidant capacity and examine the histopathology. Results: The findings revealed that the activity of CPK, CK-MB, and LDH enzymes significantly reduced in the thymoquinone treatment group compared to the MTX group (p < 0.05). On the other hand, total antioxidant capacity was significantly increased in the thymoquinone group compared to the MTX group (p < 0.05). The pathological modifications (i.e. severe congestion, edema fluid, the presence of inflammatory cells around the blood vessels, mild to moderate hemorrhaging between cardiac muscle fibers) were seen in the MTX group. The treatment groups, particularly thymoquinone, did not experience any appreciable pathological changes. Conclusion: The thymoquinone was found to have the strongest protective effect against the heart damage caused by MTX.

Immuno-protective effect of commercial IBD vaccines against emerging novel variant infectious bursal disease virus in specific-pathogen-free chickens

  • Hayatuddeen Bako Aliyu;Tasiu Mallam Hamisu;Mohd Hair-Bejo;Abdul Rahman Omar;Aini Ideris
    • Journal of Veterinary Science
    • /
    • v.25 no.5
    • /
    • pp.70.1-70.12
    • /
    • 2024
  • Importance: Infectious bursal disease (IBD) is an important viral poultry disease that vaccination can control. Objective: This study examined the immune protection of immune-complex (Vaccine A) and attenuated live (Vaccine B) IBD vaccines in specific-pathogen-free (SPF) chickens against a novel Malaysian variant IBD virus (vaIBDV) challenge. Methods: One-day-old (n =75) SPF chickens were divided randomly into the following three groups of 25 chicks each: Control, Vaccine A, and Vaccine B groups. The vaIBDV strain, UPM1432/2019, was used for the challenge at 21 and 28days post-vaccination (dpv). Five birds from unchallenged and challenged groups were sacrificed seven days post-challenge, and blood, bursa, spleen, and cloacal swabs were collected. The IBD antibodies (Abs), lymphoid lesions, and viral load were determined. Results: The UPM1432/2019 virus induced bursal damage in vaccinated SPF chickens despite Ab titers. The mean Ab titers of the Vaccine A challenged group were significantly lower (p < 0.002) than in the unchallenged group at 28 dpv. The bursal indices of the vaccinated unchallenged groups did not differ significantly from those of the vaccinated challenged groups (p = 0.94). Microscopically, the bursae of the challenged groups showed significant atrophy. The bursal lesion score was higher (p < 0.05) in the control and Vaccine B challenged groups than the Vaccine A challenged group. The challenged group had a higher viral load than the vaccinated groups (p < 0.001). Conclusions and Relevance: Neither vaccine fully protected against a vaIBDV challenge, highlighting the limitations of current vaccines and the need for further research.