• Title/Summary/Keyword: leading compound

Search Result 118, Processing Time 0.027 seconds

Mechanistic investigations on emission characteristics from g-C3N4, gC3N4@Pt and g-C3N4@Ag nanostructures using X-ray absorption spectroscopy

  • Sharma, Aditya;Varshney, Mayora;Chae, Keun Hwa;Won, Sung Ok
    • Current Applied Physics
    • /
    • v.18 no.11
    • /
    • pp.1458-1464
    • /
    • 2018
  • An improved method for the preparation of g-$C_3N_4$ is described. Currently, heating (> $400^{\circ}C$) of urea is the common method used for preparing the g-$C_3N_4$. We have found that sonication of melamine in $HNO_3$ solution, followed by washing with anhydrous ethanol, not only reduce the crystallite size of g-$C_3N_4$ but also facilitate intriguing electronic structure and photoluminescence (PL) properties. Moreover, loading of metal (Pt and Ag) nanoparticles, by applying the borohydride reduction method, has resulted in multicolor-emission from g-$C_3N_4$. With the help of PL spectra and local electronic structure study, at C K-edge, N K-edge, Pt L-edge and Ag K-edge by X-ray absorption spectroscopy (XAS), a precise mechanism of tunable luminescence is established. The PL mechanism ascribes the amendments in the transitions, via defect and/or metal states assimilation, between the ${\pi}^*$ states of tris-triazine ring of g-$C_3N_4$ and lone pair states of nitride. It is evidenced that interaction between the C/N 2p and metal 4d/5d orbitals of Ag/Pt has manifested a net detraction in the ${\delta}^*{\rightarrow}LP$ transitions and enhancement in the ${\pi}^*{\rightarrow}LP$ and ${\pi}^*{\rightarrow}{\pi}$ transitions, leading to broad PL spectra from g-$C_3N_4$ organic semiconductor compound.

Effect of Feeding Alfalfa and Concentrate on Meat Quality and Bioactive Compounds in Korean Native Black Goat Loin during Storage at 4℃

  • Kim, Hye-Jin;Kim, Hee-Jin;Kim, Kwan-Woo;Lee, Jinwook;Lee, Sang-Hoon;Lee, Sung-Soo;Choi, Bong-Hwan;Shin, Dong-Jin;Jeon, Ki-Hong;Choi, Jin-Young;Jang, Aera
    • Food Science of Animal Resources
    • /
    • v.42 no.3
    • /
    • pp.517-535
    • /
    • 2022
  • The primary aim of this study was to evaluate the effect of feeding alfalfa: Concentrate at different ratios (8:2 or 2:8) to Korean native black goats (KNBG) for 90 days on meat quality and bioactive compound content. Feeding KNBG alfalfa and concentrate at different ratios did not impact meat pH, color, microorganism composition, volatile basic nitrogen levels, or lipid oxidation. The low alfalfa (KLA) group exhibited increased oleic acid and monosaturated fatty acid levels, both of which impact the palatability traits of meat. The abundance of bioactive compounds increased in the loin meat of the KLA group, leading to an increase in antioxidant activities. Our results suggest that feeding alfalfa and concentrate at a 2:8 ratio to KNBG can increase taste-related fatty acids and bioactive compounds in loin meat, relative to that achieved by feeding at an 8:2 ratio. Further investigation is required to evaluate the quality and the metabolites of bioactive compounds in KNBG meat and the effect of the different dietary ratios of forage and concentrate.

Prevention of Citrobacter freundii (MW279218) infection in Nile tilapia, Oreochromis niloticus using zinc oxide nanoparticles

  • Korni, Fatma M. M.;Moawad, Usama K.;Mohammed, Asmaa N.;Edrees, Asmaa
    • Journal of fish pathology
    • /
    • v.35 no.1
    • /
    • pp.77-92
    • /
    • 2022
  • Aquaculture development is based on the ideas of increasing production while reducing economic losses. Bacterial diseases are the leading source of fish cases. Citrobacter freundii has been linked to septicemia and mortality all over the world. In the current study, the cause of mortality in O. niloticus was C. freundii MW279218. External hemorrhages were seen on the affected fish, as well as paleness in the liver and kidney congestion. C. freundii MW279218 had a median lethal dosage of 1.5×105 CFU/mL. Zinc oxide and zinc oxide nanoparticles (ZnO-NPs) were tested for their biocidal effectiveness against C. freundii MW279218. The lethal effect of ZnO-NPs for C. freundii MW279218 was 100% when compared to zinc oxide compound, and the inhibition zone width was 2.31.1mm at the highest tested concentrations (70 mg/L) compared to the lowest (35 and 45 mg/L, respectively). Fish were fed three different diets for 28 days: diet 1 (no additives), diet 2 (100 mg of ZnO-NPs/kg of feed), and diet 3 (200 mg of ZnO-NPs/kg of feed). Organs were also collected for histopathology 96 hours after injection (P<0.05). In the groups given 200 mg of ZnO-NPs, there was 10% mortality and 80% RPS. The group fed 100 mg of ZnO-NPs/kg, on the other hand, had 20% mortality and 60% RPS, compared to 50% mortality in the control positive group. Histopathological examinations demonstrated significant alterations in the control positive group and mild lesions in the hepatopancreas of the groups administered 100 mg ZnO-NPs/kg of feed. The groups fed 200 mg of ZnO-NPs/kg diet, on the other hand, showed no histological alterations. ZnO-NPs were found to be effective in the up regulation of both IL-10 and complement 5 immune-related genes.

Identifying the Anti-Cancer Effect of Indigo Naturalis in Small Cell Lung Cancer Based on Network Pharmacological Analysis (네트워크 약리학적 분석에 의한 소세포폐암에 대한 청대의 항암기전 연구)

  • Young Hoon, Kim;Woo Jin, Jeong;Gwang Hee, Jeong;Youn Sook, Kim;Won Gun, An
    • Journal of Physiology & Pathology in Korean Medicine
    • /
    • v.36 no.6
    • /
    • pp.229-234
    • /
    • 2022
  • Lung cancer is the leading cause of cancer-related deaths worldwide. Indigo Naturalis (IN) is a dark blue powder obtained by processing leaves or stems of indigo plants, its anticancer effects have been reported in several studies. However, the pharmacological mechanism of IN in small cell lung cancer (SCLC) is not elucidated. In this study, to investigate the anticancer efficacy of IN for SCLC, we presented potential active ingredients, SCLC-related targets, and pharmacological mechanisms of IN that are expected to have anticancer activity for SCLC using a network pharmacological analysis. The phytochemical compounds of IN have been collected through TCMSP, SymMap, or HPLC documents. The active ingredients of IN such as indirubin, indican, isatin, and tryptanthrin were selected through ADME parameters or literature investigations for each compound. Using the Compounds, Disease-Target associations Databases, 124 common targets of IN and SCLC were obtained. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) Pathway enrichment analysis was carried out. GO biological processes are associated with response to xenobiotic stimulus, positive regulation of protein phosphorylation, regulation of mitotic cell cycle, and regulation of apoptotic signaling pathway. KEGG disease pathways included Gastric cancer, Bladder cancer, SCLC, and Melanoma. The main anticancer targets of the IN for SCLC were analyzed in 14 targets, including BCL2, MYC, and TP53. In conclusion, the results of this study based on the network pharmacology of IN can provide important data for the effective prevention and treatment of SCLC.

Twin models for high-resolution visual inspections

  • Seyedomid Sajedi;Kareem A. Eltouny;Xiao Liang
    • Smart Structures and Systems
    • /
    • v.31 no.4
    • /
    • pp.351-363
    • /
    • 2023
  • Visual structural inspections are an inseparable part of post-earthquake damage assessments. With unmanned aerial vehicles (UAVs) establishing a new frontier in visual inspections, there are major computational challenges in processing the collected massive amounts of high-resolution visual data. We propose twin deep learning models that can provide accurate high-resolution structural components and damage segmentation masks efficiently. The traditional approach to cope with high memory computational demands is to either uniformly downsample the raw images at the price of losing fine local details or cropping smaller parts of the images leading to a loss of global contextual information. Therefore, our twin models comprising Trainable Resizing for high-resolution Segmentation Network (TRS-Net) and DmgFormer approaches the global and local semantics from different perspectives. TRS-Net is a compound, high-resolution segmentation architecture equipped with learnable downsampler and upsampler modules to minimize information loss for optimal performance and efficiency. DmgFormer utilizes a transformer backbone and a convolutional decoder head with skip connections on a grid of crops aiming for high precision learning without downsizing. An augmented inference technique is used to boost performance further and reduce the possible loss of context due to grid cropping. Comprehensive experiments have been performed on the 3D physics-based graphics models (PBGMs) synthetic environments in the QuakeCity dataset. The proposed framework is evaluated using several metrics on three segmentation tasks: component type, component damage state, and global damage (crack, rebar, spalling). The models were developed as part of the 2nd International Competition for Structural Health Monitoring.

Anti-Inflammatory Activities of (+)-Afzelechin against Lipopolysaccharide-Induced Inflammation

  • In-Chul Lee;Jong-Sup Bae
    • Biomolecules & Therapeutics
    • /
    • v.32 no.4
    • /
    • pp.467-473
    • /
    • 2024
  • In this study, we investigated the potential protective effects of (+)-afzelechin (AZC), a natural compound that is derived from Bergenia ligulata, on lipopolysaccharide (LPS)-induced inflammatory responses. AZC is known to have antioxidant, anticancer, antimicrobial, and cardiovascular protective properties. However, knowledge regarding the therapeutic potential of AZC against LPS-induced inflammatory responses is limited. Thus, we investigated the protective attributes of AZC against inflammatory damage caused by LPS exposure. We examined the effects of AZC on heme oxygenase (HO)-1, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) in LPS-activated human umbilical vein endothelial cells (HUVECs). In addition, the effects of AZC on the expression of iNOS, tumor necrosis factor (TNF)-α, and interleukin (IL)-1β were analyzed in the lung tissues of LPS-injected mice. Data revealed that AZC promoted the production of HO-1, inhibited the interaction between luciferase and nuclear factor (NF)-κB, and reduced the levels of COX-2/PGE2 and iNOS/NO, thereby leading to a decrease in the signal transducer and activator of transcription (STAT)-1 phosphorylation. Moreover, AZC facilitated the nuclear translocation of Nrf2, increased the binding activity between Nrf2 and the antioxidant response elements (AREs), and lowered the expression of IL-1β in the LPS-treated HUVECs. In the animal model, AZC significantly reduced the expression of iNOS in the lung tissue structure and the TNF-α level in the bronchoalveolar lavage fluid. These findings demonstrate that AZC possesses anti-inflammatory properties that regulate iNOS through the inhibition of both NF-κB expression and p-STAT-1. Consequently, AZC has potential as a future candidate for the development of new clinical substances for the treatment of pathological inflammation.

Column cleaning, regeneration and storage of silica-based columns (실리카 기반 컬럼의 세척, 재생 및 보관 가이드)

  • Matt James;Mark Fever
    • FOCUS: LIFE SCIENCE
    • /
    • no.1
    • /
    • pp.1.1-1.4
    • /
    • 2024
  • This article provides comprehensive guidance on the maintenance, cleaning, regeneration, and storage of silica-based HPLC (High-Performance Liquid Chromatography) columns. The general considerations emphasize the importance of using in-line filters and guard cartridges to protect columns from blockage and irreversible sample adsorption. While these measures help, contamination by strongly adsorbed sample components can still occur over time, leading to an increase in back pressure, loss of efficiency, and other issues. To maximize column lifetime, especially with UHPLC (Ultra-High Performance Liquid Chromatography) columns, it is advisable to use ultra-pure solvents, freshly prepared aqueous mobile phases, and to filter all samples, standards, and mobile phases. Additionally, an in-line filter system and sample clean-up on dirty samples are recommended. However, in cases of irreversible compound adsorption or column voiding, regeneration may not be possible. The document also provides specific recommendations for column cleaning procedures, including the flushing procedures for various types of columns such as reversed phase, unbonded silica, bonded normal phase, anion exchange, cation exchange, and size exclusion columns for proteins. The flushing procedures involve using specific solvents in a series to clean and regenerate the columns. It is emphasized that the flow rate during flushing should not exceed the specified limit for the particular column, and the last solvent used should be compatible with the mobile phase. Furthermore, the article outlines the storage conditions for silica based HPLC columns, highlighting the impact of storage conditions on the column's lifetime. It is recommended to flush all buffers, salts, and ion-pairing reagents from the column before storage. The storage solvent should ideally match the one used in the initial column test chromatogram provided by the manufacturer, and column end plugs should be fitted to prevent solvent evaporation and drying out of the packing bed.

  • PDF

Performance Relationship of Iron-Based Anolyte According to Organic Compound Additives and Polyoxometalate-Based Catholyte in an Aqueous Redox Flow Battery (유기화합물 첨가제에 따른 철 기반 양극과 polyoxometalate 음극 기반 수계 레독스 흐름 전지의 성능 관계)

  • Seo Jin Lee;Byeong Wan Kwon
    • Applied Chemistry for Engineering
    • /
    • v.35 no.3
    • /
    • pp.255-259
    • /
    • 2024
  • In this study, an aqueous-based redox flow battery (RFB) was constructed using tungstosilic acid (TSA), which is a kind of polyoxometalate, as the negative electrode active material and iron chloride (FeCl3) as the positive electrode active material in a sulfuric acid (H2SO4) supporting electrolyte. As a result of the cell's performance, it exhibited capacity fading and low energy efficiency. To address these issues, malic acid (MA), an organic additive, was introduced to the positive electrode active material and then tested for electrochemical properties and single cell performance. The malic acid in the iron chloride aqueous solution is working as a chelate agent, and two carboxyl groups are effectively coordinated with iron ions. It was found that MA reduced the electrolyte resistance of the positive electrode active material, leading to chemical stabilization and an increase in capacity and energy efficiency.

Enhancement of radiation effect using beta-lapachone and underlying mechanism

  • Ahn, Ki Jung;Lee, Hyung Sik;Bai, Se Kyung;Song, Chang Won
    • Radiation Oncology Journal
    • /
    • v.31 no.2
    • /
    • pp.57-65
    • /
    • 2013
  • Beta-lapachone (${\beta}$-Lap; 3,4-dihydro-2, 2-dimethyl-2H-naphthol[1, 2-b]pyran-5,6-dione) is a novel anti-cancer drug under phase I/II clinical trials. ${\beta}$-Lap has been demonstrated to cause apoptotic and necrotic death in a variety of human cancer cells in vitro and in vivo. The mechanisms underlying the ${\beta}$-Lap toxicity against cancer cells has been controversial. The most recent view is that ${\beta}$-Lap, which is a quinone compound, undergoes two-electron reduction to hydroquinone form utilizing NAD(P)H or NADH as electron source. This two-electron reduction of ${\beta}$-Lap is mediated by NAD(P)H:quinone oxidoreductase (NQO1), which is known to mediate the reduction of many quinone compounds. The hydroquinone forms of ${\beta}$-Lap then spontaneously oxidizes back to the original oxidized ${\beta}$-Lap, creating futile cycling between the oxidized and reduced forms of ${\beta}$-Lap. It is proposed that the futile recycling between oxidized and reduced forms of ${\beta}$-Lap leads to two distinct cell death pathways. First one is that the two-electron reduced ${\beta}$-Lap is converted first to one-electron reduced ${\beta}$-Lap, i.e., semiquinone ${\beta}$-Lap $(SQ)^{{\cdot}-}$ causing production of reactive oxygen species (ROS), which then causes apoptotic cell death. The second mechanism is that severe depletion of NAD(P)H and NADH as a result of futile cycling between the quinone and hydroquinone forms of ${\beta}$-Lap causes severe disturbance in cellular metabolism leading to apoptosis and necrosis. The relative importance of the aforementioned two mechanisms, i.e., generation of ROS or depletion of NAD(P)H/NADH, may vary depending on cell type and environment. Importantly, the NQO1 level in cancer cells has been found to be higher than that in normal cells indicating that ${\beta}$-Lap may be preferentially toxic to cancer cells relative to non-cancer cells. The cellular level of NQO1 has been found to be significantly increased by divergent physical and chemical stresses including ionizing radiation. Recent reports clearly demonstrated that ${\beta}$-Lap and ionizing radiation kill cancer cells in a synergistic manner. Indications are that irradiation of cancer cells causes long-lasting elevation of NQO1, thereby sensitizing the cells to ${\beta}$-Lap. In addition, ${\beta}$-Lap has been shown to inhibit the repair of sublethal radiation damage. Treating experimental tumors growing in the legs of mice with irradiation and intraperitoneal injection of ${\beta}$-Lap suppressed the growth of the tumors in a manner more than additive. Collectively, ${\beta}$-Lap is a potentially useful anti-cancer drug, particularly in combination with radiotherapy.

Synthesis of Piperlongumine Derivatives Isolated from Piper longum L. and their Inhibitory Activity on Aflatoxin $B_1$ Production (Piperlongumine 유도체 합성과 $Aflatoxin\;B_1$ 생성 억제 효과)

  • Lee, Sung-Eun;Choi, Won-Sik;Lee, Hyun-Sang;Lee, Young-Haeng;Park, Byeoung-Soo
    • Applied Biological Chemistry
    • /
    • v.46 no.4
    • /
    • pp.361-366
    • /
    • 2003
  • Anti-aflatoxigenic studies on synthetic pyridione alkaloids were conducted. Seven derivatives using piperlongumine as a leading compound were prepared from 3,4,5-trimethoxycinnamic acid (TMCA). These derivatives were analyzed for their structural confrmation and purity by HPLC, GC, GC/MS and $1^H-NMR$. 1-piperidin-1-yl-3-(3,4,5-trimethoxyphenyl)propenone (1) reaction with piperidine; 1-morpholin-4-yl-3-(3,4,5-trimethoypenyl)propenone (2) with morpholine; 1-(3,5-dimethylpiperidin-1-yl)-3-(3,4,5-trimethoxyphenyl)propenone (3) with 3,5-dimethylpiperdine; 1-(2-methylpiperidine-1-yl)-3-(3,4,5-trimethoxyphenyl)propenone (4) with 2-methylpiperidine; 1-(3-hydroxypiperidin-1-yl)-3- (3,4,5-trimethoxyphenyl)propenone (5) with 3-hydroxypiperidine hydrochloride; 1-[3- (3,4,5-trimethoxyphenyl)acryloyl]piperidin-2-one (6) with ${\delta}-valerolactam;\; and\;ethyl\;1-[3-(3,4,5-trimethoxyphenyl)acyloyl]piperidine-4-carboxylate$ (7) with ethyl isonipectotate were synthesized respectively. All derivatives showed an inhibitory activity on aflatoxin $B_1$ production. In conclusion, we believe that they might be an agent for the control of mycotoxin in agricultural commodities.