• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.2089-2092
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• 2007

Tantalum-containing metal oxides, well known for their efficiency in water splitting and H2 production, have never been used in visible light driven photodecomposition of H2S and H2 production. The present work is an attempt in this direction and investigates their efficiency. A mixed metal oxide, ZnFe2Ta2O9, with the inclusion of Fe2O3 to impart color, was prepared by the conventional ceramic route in single- and double-calcinations (represented as ZnFe2Ta2O9-SC and ZnFe2Ta2O9-DC respectively). The XRD characterization shows that both have identical patterns and reveals tetragonal structure to a major extent and a minor contribution of orthorhombic crystalline system. The UV-visible diffuse reflection spectra demonstrate the intense, coherent and wide absorption of visible light by both the catalysts, with absorption edge at 650 nm, giving rise to a band gap of 1.9 eV. Between the two catalysts, however, ZnFe2Ta2O9-DC has greater absorption in almost the entire wavelength region, which accounts for its strong brown coloration than ZnFe2Ta2O9-SC when viewed by the naked eye. In photocatalysis, both catalysts decompose H2S under visible light irradiation (λ ≥ 420 nm) and produce solar H2 at a much higher rate than previously reported catalysts. Nevertheless, ZnFe2Ta2O9-DC distinguishes itself from ZnFe2Ta2O9-SC by exhibiting a higher efficiency because of its greater light absorption. Altogether, the tantalum-containing mixed metal oxide proves its efficient catalytic role in H2S decomposition and H2 production process also.

• Conservation Science in Museum
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• v.14
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• pp.37-60
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• 2013

Conservation and analysis of wall painting Goguryeo was performed to classify the unknown fragments. The conservation naked eye observation, optical microscopy, and infrared examination were carried out in order to figure out the structure, quality of constituting materials, and damages such as cracks, and discolored fragments of colored areas. Based on such investigation, conservation was proceeded. and it was completed with strengthening the weakened pigment layer of wall blocks. In addition tombs where the wall painting fragments were excavated were investigated by making comparison with gelatin dry plates and copies possessed by National Museum of Korea. According to the result, they were Kaemachong, Gosan-ri Tomb No.1 Gamsinchong, and Wonbong-ri Tomb. The components of colors with which Goguryeo wall painting fragments were painted and the mineral pigments of the wall layer were analyzed. Portable µ-XRF spectrometer and X-ray diffractometer were employed. It showed that lime (CaCO₃) used for the wall layer, and the brown color is hematite(Fe₂O₃) and cerusite (PbCO₃) and lead oxide(PbO) were identified. In the red color, cinnabar (HgS) were detected.

• Korean Journal of Heritage: History & Science
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• v.45 no.1
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• pp.86-101
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• 2012

The constituting rocks of Multi-storied Round shape stone Pagoda of Unjusa Temple are lithic tuff and rhyolite tuff breaccia which show green or grey and also rock fragment with poor roundness are present in the structure. lithic tuff is composed of feldspar and quartz which are glassy texture and cryptocrystalline and also micro crystalline are scattered. phenocryst quartz and feldspar in the substrate composed of feldspar and opaque minerals are found in rhyolite tuff breaccia. dust, exfoliation, cavity, fracture and crack are observed in all the stone of the pagoda and the result of Infrared Thermography shows partial inter cavities have developed severely which may cause further exfoliation. In addition, a great deal of various grey, green, and yellow brown lichen as well as bryophyte are present at the upper part of eastern and western roof stone located above the third floor. Discolors remarkably shown at stereobate and roof stone are identified as inorganic pollutants such as manganese oxide, iron oxide and iron hydroxide. The stone of the pagoda of the Chemical Index of Alteration (CIA) and the Weathering Potential Index (WPI) are 55.69 and 1.12 respectively and this corresponds to a highly weathered stage. The measured values, average ultrasonic velocity 2,892m/s, coefficient of weathering 0.4k and compressive strength $1,096kg/cm^3$, suggest that the rock strength and durability are weakened.

• Journal of Animal Science and Technology
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• v.64 no.4
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• pp.717-726
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• 2022

The study evaluated different molt-inducing methods to achieve the main goal of molting in commercial layers during molting and post-molting periods. A total of 400 60-week-old Lohmann Brown layers were randomly divided into five groups (eight replicates of 10 birds for each group). Laying hens in the fasting control group received no diet from day 1 to day 10. The second group received a molt-inducing diet recommended by the breeding company. The third group received a wheat bran-based diet. The fourth group received a commercial layer diet with 8,000 ppm zinc (as zinc oxide, ZnO). The fifth group received an induced molting diet given to the second group with 8,000 ppm zinc, respectively. Egg production in the fasting control group and groups fed a diet with ZnO were significantly lower (p < 0.001) than those in groups fed the molt-inducing and wheat bran-based diets without ZnO during molting. Egg laying in the fasting control group was rapidly reduced and stopped on the 5.9th day of molting. In both groups having molt treatment with ZnO, egg production was similarly reduced and ceased on the 6.9th day and 7.0th day of molting, respectively, none of them differed significantly from the control. Layers fed molt-inducing diet or wheat bran-based diet did not reach the cessation of laying even on the 28th d of molting period. Relative weights of the ovary and growing oocytes of layers subjected to fasting or fed diets with ZnO were significantly lower than those of other groups. During the first two weeks of post molting, layers fed molt-inducing diet with ZnO showed higher egg production than the other two groups (p < 0.01). The eggshell strength in the group fed the commercial diet with ZnO was significantly higher than those fed the molt-inducing diet or wheat bran-based diets at 6 weeks of post molting (p < 0.05). These results suggest that the non-feed withdrawal molting using ZnO is more effective in inducing molting and increasing post-molt egg production and egg quality than other methods using a molt-inducing diet alone or wheat bran-based diet without ZnO.

• Journal of Life Science
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• v.33 no.6
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• pp.463-470
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• 2023

Desmarestia tabacoides Okamura is a brown macroalgae that is found worldwide. Although several genera of Desmarestia have been reported as having anti-tumorigenic, anti-melanogenic, and photoprotective properties, the anti-inflammatory activity of D. tabacoides Okamura has not yet been evaluated. In this study, we analyzed the anti-inflammatory mechanisms of D. tabacoides Okamura ethanol extract (DTEE) via the inhibition of nitric oxide (NO) and prostaglandin (PG) E₂ production and the expression of their corresponding enzymes, inducible NO synthase (iNOS), and cyclooxygenase (COX)-2. In addition, their upstream signaling molecules were evaluated by Western blot analysis, such as nuclear factor (NF)-κB, mitogen-activated protein kinase (MAPK), and phosphoinositide-3-kinase (PI3K)/Akt, in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. The DTEE treatment significantly inhibited LPS-induced NO and PGE₂ production as well as the expression of their corresponding enzymes, iNOS, and COX-2 without cytotoxicity. The stimulated transcription factor NF-κB and upstream signaling molecules extracellular signal-regulated kinase (ERK), c-Jun NH₂-terminal kinase (JNK), and p38 were attenuated by the DTEE treatment, which was statistically significant, while Akt did not provide any inhibitory effect. Moreover, the DTEE treatment significantly mitigated the LPS-activated adaptor molecules, toll-like receptor 4 (TLR4), and myeloid differentiation primary response 88 (MyD88) in the RAW 264.7 cells. These results suggest that DTEE attenuates TLR4-mediated inflammatory responses by inhibiting NF-κB activation and suppressing MAPK phosphorylation in LPS-stimulated RAW 264.7 cells.

• Korean Journal of Mineralogy and Petrology
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• v.37 no.2
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• pp.35-46
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• 2024

This study investigated the origin and mineralogical-geochemical characteristics of a small ferromanganese (Fe-Mn) nodule sample obtained from the abyssal seafloor of the Magellan Seamount cluster. To this end, X-ray diffraction and X-ray fluorescence analyses were conducted. The dark brown Fe-Mn oxides constituting the nodule had a homogeneous texture without distinguishable layers, forming around three distinct nuclei. The oxides had a low average Mn/Fe ratio of 0.73 (0.24-1.10) and were characterized by high Co content (0.41-0.85 wt.%, average = 0.58 wt.%) as well as low Ni (0.06-1.24 wt.%, average = 0.55 wt.%) and Cu (0.27-1.02 wt.%, average = 0.59 wt.%) concentrations. The maximum age of the nodule was estimated at 0.52 Ma, suggesting that it began forming during the transition from the glacial to the interglacial periods in the middle Pleistocene. The Fe-Mn oxide layer comprised vernadite, smectite, quartz, and feldspar, while the nuclei were composed of soft sediments. The presence of vernadite, a typical hydrogenetic Fe-Mn oxide mineral, along with the low Mn/Fe ratio, high Co content, and low Ni and Cu concentrations, indicates that Fe-Mn nodules on the abyssal seafloor of the Magellan Seamount cluster in the western Pacific Ocean formed through hydrogenetic processes.

• Journal of Marine Bioscience and Biotechnology
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• v.12 no.1
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• pp.29-39
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• 2020

In this study, we investigated the inhibitory potential of an ethanol extract of Carpomitra costata (EECC) (Stackhouse) Batters, a brown alga, against neuroinflammatory responses in lipopolysaccharide (LPS)-stimulated BV2 microglia. Our results showed that EECC significantly suppressed the LPS-induced secretion of pro-inflammatory mediators, including nitric oxide (NO) and prostaglandin E₂, with no significant cytotoxic effects. EECC also inhibited the LPS-induced expression of their regulatory enzymes, such as inducible NO synthase and cyclooxygenase-2. In addition, EECC downregulated the LPS-induced expression and production of the proinflammatory cytokines, tumor necrosis factor-α and interleukin-1β. In the mechanistic assessment of the antineuroinflammatory effects, EECC was found to inhibit the nuclear translocation and DNA binding of nuclear factor-kappa B (NF-κB) by disrupting the degradation of the κB-α inhibitor in the cytoplasm. Moreover, EECC effectively suppressed the enhanced expression of Toll-like receptor 4 (TLR4) and myeloid differentiation factor 88, as well as the binding of LPS to TLR4 in LPS-treated BV2 cells. Furthermore, EECC markedly reduced the LPS-induced generation of reactive oxygen species (ROS), demonstrating a strong antioxidative effect. Collectively, these results suggest that EECC repressed LPS-mediated inflammatory action in the BV2 microglia through the inactivation of NF-κB signaling by antagonizing TLR4 and/or preventing ROS accumulation. While further studies are needed to fully understand the anti-inflammatory effects associated with the antioxidant activity of EECC, the current findings suggest that EECC has a potential advantage in inhibiting the onset and treatment of neuroinflammatory diseases.

• Journal of the Korean Ceramic Society
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• v.35 no.3
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• pp.280-286
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• 1998

LaAlO3 Single crystals used as a substrate for thin film depositions of a high temperature oxide su-perconductor YB2Cu3O7 and applied to microwave frequencies were grown by the Traveling Solvent Flati-ing Zone (TSFZ) method and characterized. For the growth of LaAlO3 single crystals polycrystalline fe-edrods were prepared from powder mixture of La2O3 and Al2O3 with a mole ratio of 1:1 calcined at 110$0^{\circ}C$ for 3h and sintered at 140$0^{\circ}C$ for 4h The growth LaAlO3 crystals was 4-5mm in diameter 30mm in length and dark brown. The growth rate was 2-3mm/h and the rotation speeds were 10rpm for an upper ro-tation and 40 rpm for a lower rotation The growing crystals and the feedrods were counter-rotated. The orientation of the grown single crystals of LaAlO3 was identified to be [111] direction. Dielectric constants were measured to be 30-33 between 100 kHz and 1 MHz in the 30$0^{\circ}C$ to 45$0^{\circ}C$ temperature range and 102 in a range of 100 kHz at the phase transformation temperature of 522$^{\circ}C$ Dielectric losses were calculated to be 1.8$\times$10-4 at the room temperature and 5.7$\times$10-3 at the phase transformation temperature. Lattice con-stants of the grown crystlals were determined to be aR=5.3806 $\AA$ and $\alpha$=60.043$^{\circ}$ by the least square method.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.8
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• pp.1043-1048
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• 2010

This study investigated the effects of Fe-soy proteinate (Fe-SP) and magnesium oxide (MgO) dietary supplements on eggshell quality in laying hens. A total of 800 26-wk-old Hy-Line Brown hens were assigned to four dietary treatments: control (C), Fe-SP 100 (100 ppm Fe-soy proteinate), MgO (3 g MgO/kg diet), and Fe-SP 100+MgO. Each treatment had five replicates of 40 hens. The FT-IR (Fourier transform infrared) and XRD (X-ray diffraction) spectra of Fe-soy proteinate were different from those of $FeSO_4$ and soy digest. There were no significant differences among treatments in hen-day egg production, hen-house egg production, broken and soft egg rate, feed intake, or feed conversion. The MgO and Fe-SP 100+MgO treatments showed significantly (p<0.05) higher egg weights than the control group. Eggshell strength and thickness were significantly (p<0.05) higher in the MgO supplemented groups. The lightness and yellowness of the eggshells decreased, and the redness increased significantly in the Fe-SP treated groups. There were no significant differences among treatments in leukocyte level, but hemoglobin (Hb) concentrations were higher with Fe-SP treatments. In conclusion, supplementation with Fe-SP significantly affects eggshell color and hemoglobin concentration, whereas MgO supplementation increases eggshell strength and thickness. Egg weight and egg shell quality can be improved by supplementation of 100 ppm Fe in the form of Fe-SP and 3 g MgO/kg diet.

• Plant Resources
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• v.4 no.3
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• pp.161-170
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• 2001

A major portion of drugs used in Ayurvedic system of medicine which has been practiced since the early human civilization in Indian subcontinent were of plant origin. It should be noted that 70% of the population in this region depends on Ayurveda for their medical treatment and 60% of the drug resources are obtained from the Himalayan region. Therefore, Nepal becomes a potential source of plant drug resource since it occupies a major portion of the Himalaya. In the present paper, in general a current status of medicinal plant resources of Himalayan region especially Nepal will be discussed. In addition to this, a typical example of antidiabetic activity of Shilajit will be taken for the discussion. Shilajit is one of the crucial elements in several formulations including those of Rasayana, a therapy in Ayurveda, which has been practiced in the prevention of ageing and mental disorder. Although, Shilajit is widely used for the treatment of diabetes, no satisfactory scientific reports are available up to now. The crude Shilajit in the market is a dark brown or black rock-like substance collected from the Himalayan region with a strong smell of cow's stale urine. In our studies, Shilajit (collected in the central Himalayan region) prevented the diabetes in nonobese diabetic (NOD) mice model. Shilajit also prevented the diabetes in the rats against the action of multiple low-dose (10 mg/kg, i.v., 5 times) of streptozotocin. On the other hand, Shilajit did not show antioxidative activity. The preventive action of Shilajit on diabetes is mainly focused on the Thl and Th2 cell activities, since Th2 cells activity was found to be significantly upregulated. Shilajit, however, showed a mild action in controlling the blood sugar level in young, old, and mild diabetic rats, but not in the severe diabetic rats. It also stimulated the nitric oxide production in macrophages. Based on these evidences, the antidiabetic activities of Shilajit appear to be immunomodulative probably by protecting or strengthening insulin-producing b-cells in the pancreas. Further systematic research on constituents of Shilajit and its quality evaluation is necessary to enable the use of natural medicines in the treatment of diabetes.