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1.
China Journal of Chinese Materia Medica ; (24): 2767-2780, 2023.
Article in Chinese | WPRIM | ID: wpr-981380

ABSTRACT

The chemical compositions of Rodgersia aesculifolia were isolated and purified using a combination of silica gel, reverse phase silica gel, Sephadex LH-20 column chromatography, and semi-preparative HPLC. The structures were determined according to the physicochemical properties and spectroscopic data. The MTT method and the ABTS kit were used to measure the cytotoxicity and antioxidant capacity of all isolates, respectively. Thirty-four compounds were isolated from R. aesculifolia and elucidated as stigmastane-6β-methoxy-3β,5α-diol(1), stigmastane-3β,5α,6β triol(2), β-sitosterol(3), β-daucosterol(4), stigmast-4-en-3-one(5), bergenin(6), 11-β-D-glucopyranosyl-bergenin(7), 11-O-galloybergenin(8), 1,4,6-tri-O-galloyl-β-D-glucose(9), gallic acid(10), 3,4-dihydroxybenzoic acid methyl ester(11), ethyl gallate(12), ethyl 3,4-dihydroxybenzoate(13), caffeic acid ethyl ester(14), p-hydroxybenzeneacetic acid(15), 4-hydroxybenzoic acid(16), 2,3-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)-propan-1-one(17), 3,7-dimethyl-2-octene-1,7-diol(18), crocusatin-B(19), neroplomacrol(20), geniposide(21), 3-hydroxyurs-12-en-27-oic acid(22), 3β-trans-p-coumaroyloxy-olean-12-en-27-oic acid(23), aceriphyllic acid G(24), isolariciresinol(25), trans-rodgersinine B(26), cis-rodgersinine A(27), neo-olivil(28),(7S,8R)-dihydro-3'-hydroxy-8-hydroxy-methyl-7-(4-hydroxy-3-methoxy phenyl)-1'-benzofuranpropanol(29), 5,3',4'-trihydroxy-7-methoxyflavanone(30), quercetin 3-rutinoside(31), catechin-[8,7-e]-4β-(3,4-dihydroxy-phenyl)-dihydro-2(3H)-pyranone(32), ethyl α-L-arabino-furanoside(33), and l-linoleoylglycerol(34). One new compound was discovered(compound 1), 25 compounds were first isolated from R. aesculifolia, and 22 compounds were first isolated from the Rodgersia plant. The results indicated that compounds 22-24 possessed cytotoxicity for HepG2, MCF-7, HCT-116, BGC-823, and RAFLS cell lines(IC_(50) ranged from 5.89 μmol·L~(-1) to 20.5 μmol·L~(-1)). Compounds 8-14 and 30-32 showed good antioxidant capacity, and compound 9 showed the strongest antioxidant activity with IC_(50) of(2.00±0.12) μmol·L~(-1).


Subject(s)
Antioxidants/analysis , Silica Gel/analysis , Plant Roots/chemistry
2.
Chinese Journal of Schistosomiasis Control ; (6): 269-276, 2022.
Article in Chinese | WPRIM | ID: wpr-940947

ABSTRACT

OBJECTIVE@#To evaluate the storage stability of metabolites from actinomycetes Streptomyces nigrogriseolus XD 2-7 and the mollcuscicidal activity against Oncomelania hupensis in the laboratory, and to preliminarily explore the mechanisms of the molluscicidal activity.@*METHODS@#The fermentation supernatant of S. nigrogriseolus XD 2-7 was prepared and stored at -20, 4 °C and 28 °C without light for 10 d; then, the molluscicidal effect was tested against O. hupensis following immersion for 72 h. The fermentation supernatant was boiled in a 100 °C water bath for 30 min and recovered to room temperature, and then the molluscicidal effect was tested against O. hupensis following immersion for 72 h. The pH values of the fermentation supernatant were adjusted to 4.0, 6.0 and 9.0 with concentrated hydrochloric acid and sodium hydroxide, and the fermentation supernatant was stilled at room temperature for 12 h, with its pH adjusted to 7.0; then, the molluscicidal effect was tested against O. hupensis following immersion for 72 h. The fermentation product of S. nigrogriseolus XD 2-7was isolated and purified four times with macroporous resin, silica gel and octadecylsilane bonded silica gel. The final products were prepared into solutions at concentrations of 10.00, 5.00, 2.50, 1.25 mg/L and 0.63 mg/L, and the molluscicidal effect of the final productswas tested against O. hupensis following immersion for 72 h, while dechlorination water served as blank controls, and 0.10 mg/L niclosamide served as positive control. The adenosine triphosphate (ATP) and adenosine diphosphate (ADP) levels were measured in in O. hupensis soft tissues using high performance liquid chromatography (HPLC) following exposure to the final purified fermentation products of S. nigrogriseolus XD 2-7.@*RESULTS@#After the fermentation supernatant of S. nigrogriseolus XD 2-7 was placed at -20, 4 °C and 28 °C without light for 10 d, immersion in the stock solution and solutions at 10- and 50-fold dilutions for 72 h resulted in a 100% (30/30) O. hupensis mortality. Following boiling at 100 °C for 30 min, immersion in the stock solution and solutions at 10- and 50-fold dilutions for 72 h resulted in a 100.00% (30/30) O. hupensis mortality. Following storage at pH values of 4.0 and 6.0 for 12 h, immersion in the fermentation supernatant of S. nigrogriseolus XD 2-7 for 72 h resulted in a 100.00% (30/30) O. hupensis mortality, and following storage at a pH value of 9.0 for 12 h, immersion in the fermentation supernatant of S. nigrogriseolus XD 2-7 for 72 h resulted in a 33.33% (10/30) O. hupensis mortality (χ2 = 30.000, P < 0.05). The minimum concentration of the final purified fermentation products of S. nigrogriseolus XD 2-7 was 1.25 mg/L for achieving a 100% (30/30) O. hupensis mortality. The ATP level was significantly lower in O. hupensis soft tissues exposed to 0.10 mg/L and 1.00 mg/L of the final purified fermentation products of S. nigrogriseolus XD 2-7 than in controls (F = 7.274, P < 0.05), while no significant difference was detected in the ADP level between the treatment group and controls (F = 2.485, P > 0.05).@*CONCLUSIONS@#The active mollcuscicidal ingredients of the S. nigrogriseolus XD 2-7 metabolites are maintained stably at -20, 4 °C and 28 °C for 10 d, and are heat and acid resistant but not alkali resistant. The metabolites from S. nigrogriseolus XD 2-7 may cause energy metabolism disorders in O. hupensis, leading to O. hupensis death.


Subject(s)
Animals , Adenosine Diphosphate/pharmacology , Adenosine Triphosphate , Molluscacides/pharmacology , Silica Gel/pharmacology , Snails , Streptomyces , Water
3.
Chinese Acupuncture & Moxibustion ; (12): 457-458, 2022.
Article in Chinese | WPRIM | ID: wpr-927407

ABSTRACT

In order to comprehensively stretch human fascia, adjust the biomechanical balance of fascia system and promote the recovery of physiological function of fascia, a new type of fascia stretching cup is designed. This design is composed of two or more silica gel cups and elastic stretching belts between cups. The bottom surface of the silica gel cup has an annular exhaust groove, which can increase the adsorption capacity of the cup to the skin. In the meanwhile, a removable magnet is placed in the groove at the top of each silica gel cup to assist analgesia. This design is suitable for the prevention and treatment of acute and chronic tendon and bone diseases with imbalance of meridians and tendons.


Subject(s)
Humans , Fascia , Silica Gel , Skin
4.
São José dos Campos; s.n; 20210000. 71 p. ilus., tab, graf.
Thesis in Portuguese | LILACS | ID: biblio-1358876

ABSTRACT

Este estudo avaliou influência de diferentes métodos de acabamento de superfície na probabilidade de sobrevivência de restaurações de zircônia translúcida e o potencial de desgaste ao antagonista. Foram utilizados 220 preparos confeccionados em resina epóxi (Nema G10) que receberam restaurações do tipo "table top" de zircônia e dissilicato de lítio (1.0 mm de espessura), 100 em YZ HT, 100 em KATANA UTML e 20 em IPS e.max CAD. Cada grupo de zircônia foi dividido em cinco subgrupos de acordo com o acabamento de superfície: Polimento - borrachas diamantadas com 2 granulações; Glaze - camada de glaze; Polimento e Glaze - polimento e glaze associados; Infiltração com sílica; Infiltração com vidro. As restaurações de dissilicato de lítio receberam uma camada de glaze. Os espécimes foram submetidos à fadiga deslizante em uma máquina de ensaio com carga de 200 N, a uma frequência de 4 Hz, totalizando 1.250.000 ciclos. A cada 416.666 ciclos a máquina foi interrompida e as restaurações foram avaliadas quanto à presença de falhas em estereomicroscópio. O antagonista foi analisado quanto aos parâmetros de desgaste. Foram realizadas análises de rugosidade, microestruturais e fractográfica. Kaplan ­ Meier, Mantel ­ Cox (log-rank) e ANOVA compararam os dados. Não foram observadas diferenças para profundidade de desgaste entre os grupos de zircônia, porém os acabamentos glaze e infiltração de vidro promoveram maior volume de desgaste do que a infiltração de sílica e polimento e glaze. Ambas zircônias promoveram maior profundidade e volume de desgaste ao antagonista do que o dissilicato de lítio. Foi observada diferença na rugosidade entre o tipo de zircônia e os acabamentos de superfície, enquanto que o dissilicato de lítio apresentou rugosidade semelhante as zircônias com glaze. Micrografias (MEV) demonstraram a remoção dos acabamentos de superfície após a fadiga deslizante para todos os grupos. A análise fractográfica demonstrou que as fraturas tiveram início na área de contato oclusal e a análise de cross-section demonstrou que Katana e e.max CAD apresentaram mais defeitos na superfície após a fadiga do que a Vita. A zircônia Vita apresentou maior probabilidade de sobrevivência comparado a Katana e ao dissilicato de lítio. Restaurações de zircônia com os acabamentos polimento+glaze e infiltração de sílica promoveram menor volume de desgaste ao antagonista comparadas as restaurações de zircônia com glaze ou infiltradas com vidro, enquanto o polimento apresentou o mesmo potencial abrasivo de todos os acabamentos. Além disso, a vitrocerâmica apresentou menor potencial de desgaste do antagonista do que ambas as zircônias.


This study evaluated the surface finishes influence on the survival probability of translucent zirconia restorations and also the wear potential against steatite antagonist. 220 epoxy resin (Nema G10) preparations received zirconia and lithium disilicate table top restorations (1.0 mm thickness), 100 milled in YZ HT, 100 in KATANA UTML and 20 in IPS e.max CAD. Each zirconia group was divided into five subgroups according to the surface finish: Polishing (P) 2 granulations diamond rubbers; Glaze (G) glaze layer; Polishing and Glaze (PG) polishing and glaze associated; Silica infiltration (IS); Glass infiltration (IV). The lithium disilicate restorations received a glaze layer (EG). The specimens were submitted to sliding fatigue test in a mechanical machine against steatite sphere. The parameters were: 200 N loads, 4 Hz of frequency, totaling 1,250,000 cycles. Every 416,666 cycles the restorations were evaluated in stereomicroscope for failures presence (cracks, fractures or detachment of the restorations). Roughness, microstructural, fractographic and wear analysis were performed. Kaplan­Meier, Mantel­Cox (log-rank) and ANOVA compared the data. The failure survival was different among the groups. No difference was observed for wear depth among zirconia groups, whereas glaze and glass infiltration promoted greater volume loss than silica infiltration and polishing plus glaze. Both zirconia promoted greater volume loss and wear depth to the antagonist than lithium disilicate. Difference was observed for roughness among the zirconia and surface finishes, while lithium disilicate presented similar roughness compared to both glazed zirconia. Micrographs (SEM) showed the surface finishes removal after sliding fatigue for all groups. Fractographic analysis showed occlusal contact area as fractures origin and the cross-section analysis showed that Katana and e.max CAD presented more surface defects after fatigue than Vita. The Vita restorations presented higher survival probability compared to Katana and lithium disilicate restorations. Zirconia polished+glaze and silica infiltration promoted less antagonist volume loss compared to glazed or glass infiltrated, while polishing had the same wear potential as all finishes. In addition, the glass-ceramic presented less potential to wear the antagonist than both zirconia.


Subject(s)
Ceramics , Dental Prosthesis , Dental Restoration Failure , Dental Restoration Wear , Silica Gel
5.
Chinese Journal of Biotechnology ; (12): 4075-4082, 2021.
Article in Chinese | WPRIM | ID: wpr-921488

ABSTRACT

The rapid screening of tumor markers is a challenging task for early diagnosis of cancer. This study aims to use highly sensitive chemiluminescent protein microarray technology to efficiently screen a variety of low abundance tumor related markers. A new material, termed integrated polydimethylsiloxane modified silica gel (iPDMS), was obtained by adding a surface polymerization initiator with olefin end to the conventional polydimethylsiloxane, and fixing into the three-dimensional structure of polydimethylsiloxane by thermal crosslinking through silicon hydrogen bonding. In order to make the iPDMS material resistant to non-specific protein adsorption, a poly(OEGMA) polymer brush was synthesized by surface-initiated atom transfer radical polymerization at the active initiation site. Finally, 20 tumor-related antigens were printed into the specific areas of the microarray by high-throughput spray printing technology, and assembled into 48-well detection microtiterplates of the iPDMS microarray. It was found the VEGFR and VEGF121 autoantibodies that obtained from 8 common tumors (breast cancer, lung cancer, colon cancer, gastric cancer, liver cancer, leukemia, lymphoma and ovarian cancer) can be used as potential tumor markers. The chemiluminescence labeled iPDMS protein microarray can be used for the screening of tumor autoantibodies at early stage.


Subject(s)
Adsorption , Autoantibodies , Dimethylpolysiloxanes , Protein Array Analysis , Silica Gel , Surface Properties
6.
Mycobiology ; : 256-260, 2019.
Article in English | WPRIM | ID: wpr-760533

ABSTRACT

Neuraminidase (NA) cleaves the glycosidic bond linkages of sialic acids to release the mature virions from infected cells and has been an attractive therapeutic target for anti-influenza agents. In our ongoing investigation of NA inhibitors in mushroom extracts, we found that the extract the fruiting body of Glaziella splendens potently inhibited neuraminidase. The fruiting bodies of G. splendens were extracted and partitioned successively with hexane, ethyl acetate, and butanol. The ethyl acetate soluble-layer was subjected to silica gel and Sephadex LH-20 column chromatographies, and MPLC to obtain five compounds (1–5). Their structures were determined by spectroscopic methods. NA inhibitory activity of these compounds was evaluated using NAs from recombinant rvH1N1, H3N2, and H5N1 influenza A viruses. One compound (1) was elucidated as a new azaphilone derivative, and four compounds (2–5) were identified as entonaemin A, comazaphilone D, rubiginosin A, and entonaemin B, respectively. Compounds 3 and 4 showed considerable inhibitory activity against three types of neuraminidases with the IC₅₀ values of 30.9, 41.8, and 35.7 µM for 3 and 46.5, 50.4, and 29.9 µM for 4, respectively. This study reveals that the fruiting bodies of G. splendens possess azaphilone derivatives with the NA inhibitory activity. This is the first report on the isolation of neuraminidase inhibitors from the fruiting bodies of G. splendens.


Subject(s)
Agaricales , Chromatography , Fruit , Influenza A virus , N-Acetylneuraminic Acid , Neuraminidase , Sialic Acids , Silica Gel , Virion
7.
Natural Product Sciences ; : 47-53, 2018.
Article in English | WPRIM | ID: wpr-741597

ABSTRACT

Callophylum symingtonianum (Guttiferae), an evergreen broad-leaved tree that usually grows in hill forests, can be found distributed in the Malay Peninsula. The barks, leaves, flowers and seeds is often used medicinally to treat diarrhea and rheumatism. In the present study, we isolated two inophyllum type coumarins, 12-O-ethylinophyllum D (1) and iso-soulattrolide (2) from the stembarks of C. symingtonianum together with their antibacterial activity. The compounds were isolated by chromatographic methods on a silica gel. The structures were established by spectroscopic methods including UV, IR, (1D and 2D) NMR and mass spectrometry as well as by comparison with several literature sources. The antibacterial activity of those compounds was tested using a disc-diffusion assay against Staphylococcus aureus, Bacillus cereus, Escherichia coli and Pseudomonas aeruginosa. Both compound exhibited mild inhibition against P. aeruginosa with both 111 µg/ml MIC value. Compound 2 also inhibits S. aureus with 25 µg/ml MIC value.


Subject(s)
Bacillus cereus , Calophyllum , Coumarins , Diarrhea , Escherichia coli , Flowers , Forests , Malaysia , Mass Spectrometry , Pseudomonas aeruginosa , Rheumatic Diseases , Silica Gel , Staphylococcus aureus , Trees
8.
Safety and Health at Work ; : 479-485, 2018.
Article in English | WPRIM | ID: wpr-718511

ABSTRACT

The aim of this study is to validate an integrated air monitoring approach for assessing airborne formaldehyde (FA) in the workplace. An active sampling by silica gel impregnated with 2,4-dinitrophenylhydrazine, a passive solid phase microextraction technique using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine as on-fiber derivatization reagent, an electrochemical direct-reading monitor, and an enzyme-based badge were evaluated and tested over a range of 0.020–5.12 ppm, using dynamically generated FA air concentrations. Simple linear regression analysis showed the four methods were suitable for evaluating airborne FA. Personal and area samplings in 12 anatomy pathology departments showed that the international occupational exposure limits in the GESTIS database were frequently exceeded. This monitoring approach would allow a fast, easy-to-use, and economical evaluation of both current work practices and eventual changes made to reduce FA vapor concentrations.


Subject(s)
Humans , Chromatography , Formaldehyde , Linear Models , Occupational Exposure , Pathology , Silica Gel , Solid Phase Microextraction
9.
São José dos Campos; s.n; 2018. 75 p. il., tab., graf..
Thesis in Portuguese | LILACS, BBO | ID: biblio-915209

ABSTRACT

O objetivo do estudo foi avaliar os efeitos de diferentes infiltrações de sílica pelo método sol-gel realizado com a presença de catalisadores nas propriedades mecânicas, microestrutura, características de superfície de uma zircônia Y-TZP, e na resistência de união entre a zircônia e um cimento resinoso, bem como avaliar a energia interfacial (tenacidade à fratura) na união de zircônia infiltrada por sílica ou vidro ao cimento resinoso. O estudo foi segmentado em duas partes, na parte A foram confeccionados 210 discos de Zircônia Y-TZP e divididos em 6 grupos, infiltrados por ácido silícico obtido por TEOS, infiltrados por ácido silícico obtido por metassilicato de sódio (Na2SiO3): sem catalisador, com catalisador, com duas e três imersões, e o grupo não infiltrado (controle). Os discos foram caracterizados com DRX, FT-IR e MEV, e depois foram submetidos ao ensaio de resistência à flexão biaxial. Os dados foram analisados com a estatística descritiva, ANOVA 1-fator e Teste de Tukey (95%), e também com a Análise de Weibull para determinar a homogeneidade estrutural. Adicionalmente foram produzidos espécimes retangulares de zircônia, que foram divididos da mesma forma que os grupos citados acima, para a realização do teste de resistência de união. Os espécimes infiltrados foram tratados com ácido fluorídrico 2% por 10 segundos e depois silanizados. Uma matriz de silicone foi adaptada com cera sobre as superfícies tratadas da zircônia e o cimento resinoso foi inserido dentro da matriz e fotopolimerizado. Metade das amostras foram ensaiadas após 24 horas da cimentação e a outra metade foi termociclada por 6x103 ciclos térmicos (5°C-55°C) e ensaiadas ao final. Foi realizado o teste de cisalhamento com fio numa máquina de ensaios universal. Os dados foram analisados com ANOVA 1-fator e Teste de Tukey (95%). Na parte B deste trabalho, foram confeccionados espécimes Brazil nut para realizar o teste de tenacidade à fratura interfacial. As amostras foram usinadas e divididas em 3 grupos: não infiltradas (controle), infiltradas com ácido silícico obtido pelo metasilicato de sódio com catalisador com duas imersões e infiltradas com vidro pelo método proposto por Zhang e Kim (2009). As amostras do grupo controle foram jateadas com óxido de alumínio, as amostras infiltradas com ácido silícico e por vidro foram condicionadas com ácido fluorídrico. Todas as amostras foram silanizadas e cimentadas. Os espécimes foram armazenados por sete dias em uma estufa. Metade das amostras foram ensaiadas e a outra metade foi envelhecida por 4x104 ciclos térmicos (5°C-55°C) e ensaiadas ao final. Foi realizado um teste de compressão com os espécimes colocados em 5 diferentes angulações (0°, 5°, 10°, 15°, 25°), dessa forma foram obtidas fraturas em tração pura, cisalhamento puro ou em ambos os modos. Foi calculada a energia interfacial para fratura da interface adesiva. Todas as superfícies dos espécimes foram observadas em estereomicroscópio e MEV para determinar as características de fratura (caminho percorrido pela trinca). Nas imagens de MEV das superfícies dos discos foi possível observar a presença da camada de sílica entremeada aos grãos de zircônia. No grupo infiltrado por TEOS a infiltração ocorreu de forma menos homogênea. Os espectros de DRX mostraram a formação de uma fase cristalina intermediária de silicato de zircônia em todos os espécimes infiltrados. Em relação as propriedades mecânicas, os resultados mostraram que as infiltrações foram efetivas e houve a formação de multicamadas de sílica sobre a zircônia. O grupo infiltrado por três vezes consecutivas e controle mostraram a maior resistência à flexão, já o grupo infiltrado por duas vezes consecutivas mostrou a maior homogeneidade estrutural. Os resultados da parte B do estudo mostraram que a zircônia infiltrada por vidro aderida com cimento resinoso à base de monômeros fosfatados tem o maior valor de tenacidade interfacial, mesmo após o envelhecimento. Os grupos controle e sol-gel foram estatisticamente semelhantes. O envelhecimento não afetou os grupos sol-gel e infiltrado por vidro, mas causou uma diminuição nos valores de Gc do grupo controle. As análises de fratura mostraram que as falhas coesivas de cimento foram predominantes no grupo infiltrado por vidro, já as falhas adesivas foram observadas em todos os grupos. A duas infiltrações, sol-gel e por vidro, preveniram a transformação de fase da zircônia, enquanto o grupo controle mostrou um aumento de 6% de fase monoclínica após o envelhecimento. Assim, pode-se concluir que as infiltrações de sílica são efetivas e geram um material mais homogêneo e mais susceptível à adesão ao cimento resinoso, e que o melhor padrão foi encontrado ao infiltrar sílica obtida através do metassilicato de sódio com duas imersões. O método de infiltração por vidro aumenta a tenacidade à fratura interfacial da zircônia cimentada com cimento resinoso à base de monômeros fosfatados, e o envelhecimento não afeta a tenacidade à fratura interfacial de ambas as infiltrações (sílica e vidro).(AU)


The objective of this study was to evaluate the effects of different silica infiltrations by the sol-gel method performed with catalyst on the mechanical properties, microstructure, surface characteristics of a Y-TZP zirconia, and the bond strength between zirconia and a resin cement. Also evaluate the fracture toughness at the junction of zirconia infiltrated by silica or glass to the resin cement. 210 Zirconia Y-TZP discs were prepared and divided into 6 groups, infiltrated by silicic acid obtained by TEOS, infiltrated by silicic acid obtained by sodium metasilicate (Na2SiO3): without catalyst, with catalyst, with two and three immersions, and non-infiltrated group (control). The disks were characterized with XRD and SEM, and were then subjected to the biaxial flexural strength test. The data were analyzed with descriptive statistics, 1-way ANOVA and Tukey Test (95%), and also with Weibull Analysis to determine the structural homogeneity. Additionally, rectangular zirconia specimens were produced which were divided as the groups cited above for the bond strength test. The infiltrated specimens were treated with hydrofluoric acid, then all specimens were silanized. A silicon matrix was waxed onto the zirconia treated surfaces and the resin cement was inserted into the matrix and photopolymerized. Half of the samples were tested after 24 hours of cementation and the other half was thermocycled by 6x103 thermal cycles (5°C-55°C) and tested at the end. The wire shear test was performed on a universal testing machine. The data were analyzed with 1-way ANOVA and Tukey Test (95%). In the second part of this work, Brazil nut specimens were made to perform the interfacial fracture toughness test. The samples were machined and divided into 3 groups: non-infiltrated (control), infiltrated with silicic acid obtained by sodium metasilicate with catalyst and two immersions, and infiltrated with glass by the method proposed by Zhang and Kim (2009). The samples from the control group were sandblasted with aluminum oxide, the samples infiltrated with silicic acid and glass were conditioned with hydrofluoric acid. All samples were silanized and cemented. The specimens were stored for seven days, half of the samples were tested and the other half was aged for 4x104 thermal cycles (5°C-55°C) and tested at the end. A compression test was performed with the specimens placed at 5 different angles (0°, 5°, 10°, 15°, 25°), thus obtaining fractures in pure traction, pure shear or in mixity modes. The interfacial energy was calculated for fracture of the adhesive interface. All surfaces of the specimens were observed in stereomicroscope and SEM to determine the fracture characteristics. In the SEM images of the disc surfaces it was possible to observe the presence of the silica layer dispersed with the zirconia grains. In the group infiltrated by TEOS, the infiltration was less homogeneously. XRD spectra showed the formation of an intermediate crystalline phase of zirconia silicate in all infiltrated specimens. In relation to the mechanical properties, the results showed that the infiltrations were effective and formed silica multilayers on zirconia The group infiltrated for three consecutive times showed the greatest flexural strength and was similar to the control group, but the infiltrated group by two consecutive times showed the greatest structural homogeneity. The part B results showed that glass-infiltrated zirconia had the highest interfacial toughness value even after aging. The control and sol-gel groups were statistically similar. Aging did not affect the sol-gel and glassinfiltrated groups, but caused a decrease in interfacial toughness values of the control group. The fracture analysis showed that the cohesive defects of cement were predominant in the glass-infiltrated group, and adhesive failures were observed in all groups. Both infiltrations, sol-gel and glass, prevented the phase transformation of zirconia, while the control group showed a 6% increase in monoclinic phase content after aging. Thus, it can be concluded that silica infiltrations are effective and generate a more homogeneous material and more susceptible to adhesion to the resin cement, and that the best standard to infiltrate was found using silica obtained through sodium metasilicate with two immersions. The glass infiltration method increases the interfacial fracture toughness of the zirconia, and aging does not affect the interfacial fracture toughness of both infiltrations (silica and glass)(AU)


Subject(s)
Humans , Silicates , Metal Ceramic Alloys/classification , Silica Gel
10.
Mycobiology ; : 44-47, 2017.
Article in English | WPRIM | ID: wpr-729889

ABSTRACT

Ginseng damping-off, caused by the fungal pathogens Rhizoctonia solani and Pythium sp., is a critical disease in ginseng seedling. In a continuing effort to find microorganisms with the potential of acting as a biocontrol agent against Rhizoctonia damping-off, we found that a Streptomyces sp. A501 showed significant antifungal activity against Rhizoctonia solani. In field experiment to test the efficacy of Streptomyces sp. A501 in controlling ginseng damping-off, the incidence of damping-off disease was meaningfully reduced when ginseng seeds were soaked in the culture broth of Streptomyces sp. A501 before sowing. To perform characterization of the antifungal compound, we isolated it from the culture broth of strain A501 through Diaion HP-20 and silica gel column chromatographies and preparative high-performance liquid chromatography. The structure of the antifungal compound was assigned as fungichromin by spectroscopic methods, mainly nuclear magnetic resonance and electrospray ionization-mass analysis.


Subject(s)
Chromatography , Chromatography, Liquid , Incidence , Magnetic Resonance Spectroscopy , Panax , Pythium , Rhizoctonia , Seedlings , Silica Gel , Streptomyces
11.
Sâo Jose dos Campos; s.n; 2017. 78 p. ^cgraf.; tab.78 il..
Thesis in Portuguese | LILACS | ID: biblio-847794

ABSTRACT

Neste trabalho avaliou-se o comportamento mecânico e a homogeneidade estrutural de bilaminados cerâmicos com configuração convencional (compressão da zircônia) e bioinspirada (tração da zircônia) com e sem infiltração de sílica. Além disso, determinou-se a distribuição de tensões utilizando a análise de elementos finitos, e avaliou-se o modo de falha e o mecanismo de adesão da interface porcelana/zircônia. Amostras bilaminadas foram confeccionadas com Y-TZP e cerâmica injetável e divididos em 4 grupos (n=30): zircônia sob compressão (T), zircônia infiltrada sob compressão (I), zircônia sob tração (B) e zircônia infiltrada sob tração (BI); para teste da resistência à flexão biaxial. A infiltração por sílica ocorreu pelo método sol-gel. Os dados (MPa) do ensaio mecânico foram avaliados com análise de Weibull (IC 95 %). Análise de elementos finitos utilizou o critério de tensão máxima principal para avaliar a distribuição de tensões nos modelos e seus resultados foram apresentados em forma de figuras e gráficos da tensão máxima principal (TMP). A camada de infiltração foi caracterizada usando DRX e microscopia (MEV, MEV-FEG e EDS). O comportamento da interface foi analisado usando resistência ao risco e dureza. O grupo mais homogêneo estruturalmente foi o BI (m= 9,59). A concentração de tensão na cerâmica feldspática foi menor nos grupos bioinspirados. Houve formação de silicato de zircônia na superfície dos discos de zircônia infiltrados e preenchimento de defeitos superficiais e internos. A zircônia tradicional teve desempenho melhor do que a zircônia infiltrada no teste de resistência ao risco. A endentação interfacial mostrou que o elo mais fraco do conjunto é a cerâmica feldspática. Conclui-se que para melhorar o desempenho de bilaminados é preciso melhorar o material de recobrimento e não a adesão entre os materiais(AU)


This study analyzed the mechanical behavior of bilayers using conventional arrangement (leucite ceramic under traction) and a bioinspired arrangement (zirconia under traction) with or without sol-gel silica infiltration, analyze stress distribution using FEA, characterize infiltration layer and observe interfacial behavior. 120 bilayered specimens were produced for biaxial flexural strength testing using Y-TZP and pressed ceramic and divided into 4 groups (n=30): zirconia under compression (T), infiltrated zirconia under compression (I), zirconia under traction (B) and infiltrated zirconia under traction (BI). The zirconia was infiltrated using sol-gel method. The results for the biaxial flexural strength (MPa) were analyzed using Weibull analysis (CI 95 %). Stress distribution within the models were examined using maximum principal stress and the results were presented as graphs and figures. The infiltration layer was characterized using XRD and microscopy (SEM, FEG-SEM and EDS). The interfacial behavior was analyzed using scratch test and micro-hardness indentation. The BI group was the most reliable (m=9.59). The stress distribution in the feldspar ceramic was better for the bioinspired groups. The infiltrated zirconia discs presented zirconia silicate formation on the surface and plugged internal flaws. The traditional zirconia had a better scratch performance compared to the infiltrated zirconia. The interfacial indentation showed that the weakest link of the set is the feldspar ceramic. To improve the performance of bilayers, a better coverage material is needed rather than an improvement in adhesion(AU)


Subject(s)
Humans , Ceramics , Dental Leakage , Silica Gel , X-Rays
12.
Pakistan Journal of Pharmaceutical Sciences. 2016; 29 (2): 477-484
in English | IMEMR | ID: emr-176379

ABSTRACT

Two simple, preciseand stability-indicating densitometric HPTLC method were developed and validated for qualitative and quantitative analysis of Coenzyme Q10in pharmaceutical formulations using normal-phase [Method I] and reversed phase [Method II] silica gel TLC plates. Both methods were developed and validated with 10x20cm glassbacked plates coated with 0.2mm layers of either silica gel 60 F[254] [E-Merck, Germany] using hexane-ethyl acetate [8.5:1.5v/v] as developing system [Method I] or RP-18 silica gel 60 F[254] [E-Merck, Germany] using methanol-acetone [4:6v/v] as mobile phase [Method II]. Both analyses were scanned with a densitometer at 282 nm. Linearity was found in the ranges 50-800ng/spot [r[2]=0.9989] and 50-800ng/spot [r[2]=0.9987] for Method I and Method II respectively. Stability of Coenzyme Q10 was explored by the two methods using acid, base, hydrogen peroxide, temperature and different solvents. Due to the efficiency of the method in separating Coenzyme Q10 from other ingredients including its degradation products, it can be applied for quality control, standardization of different pharmaceutical formulations and stability study


Subject(s)
Densitometry , Chromatography, High Pressure Liquid , Chemistry, Pharmaceutical , Silica Gel
13.
Natural Product Sciences ; : 220-224, 2016.
Article in English | WPRIM | ID: wpr-192314

ABSTRACT

Anti-Helicobacter pylori activity guided fractionation led to the isolation of five anthraquinones, two stilbenes and one naphthoquinone from the EtOAc fraction of Polygonum cuspidatum, using silica gel column chromatography, Sephadex-LH20, MPLC and recrystallization. The chemical structures were identified to be physcion (1), emodin (2), anthraglycoside B (3), trans-resveratrol (4), anthraglycoside A (5), polydatin (6), 2-methoxy-6-acetyl-7-methyljuglone (7) and citreorosein (8) by UV, ¹H-NMR, ¹³C-NMR and mass spectrometry. Anti-Helicobacter pylori activity including MIC values of each compound was evaluated. All of the isolates exhibited anti-H. pylori activity of which MIC values were lower than that of a positive control, quercetin. Compounds 2 and 7 showed potent growth inhibitory activity. Especially, a naphthoquinone, compound 7 displayed most potent antibacterial activity with MIC₅₀ value of 0.30 µM and MIC₉₀ value of 0.39 µM. Although anti-H. pylori activity of this plant was previously reported, this is the first report on that of compounds isolated from this species. From these findings, P. cuspidatum roots or its isolates may be useful for H. pylori infection and further study is needed to elucidate mechanism of action.


Subject(s)
Anthraquinones , Chromatography , Emodin , Fallopia japonica , Mass Spectrometry , Plants , Polygonum , Quercetin , Silica Gel , Stilbenes
14.
Korean Journal of Legal Medicine ; : 133-137, 2016.
Article in Korean | WPRIM | ID: wpr-227318

ABSTRACT

Dehumidifying agents are commonly used to remove moisture and odors and are not meant for oral ingestion. The hazards of accidental oral ingestion of dehumidifying agents are not well known. A 31-year-old man with autism drank the liquid desiccant contained in the barrel of a dehumidifier while sleepwalking. The desiccant mainly consisted of calcium chloride. He was taken to the emergency center with persistent vomiting and underwent gastric lavage. The patient was treated for hypercalcemia due to calcium chloride poisoning. He eventually died of multiple organ failure. Autopsy findings were as follows: acute suppurative pneumonia, intra-abdominal inflammation, liver necrosis, acute pancreatitis, and gastrointestinal hemorrhage. Calcium chloride has relatively low toxicity; however, when ingested orally, it can cause severe internal damage, and even death. We suggest active preventive measures to ensure the safe use of dehumidifying agents.


Subject(s)
Adult , Humans , Autistic Disorder , Autopsy , Calcium Chloride , Eating , Emergencies , Gastric Lavage , Gastrointestinal Hemorrhage , Hypercalcemia , Inflammation , Liver , Multiple Organ Failure , Necrosis , Odorants , Pancreatitis , Pneumonia , Poisoning , Silica Gel , Somnambulism , Vomiting
15.
Natural Product Sciences ; : 64-69, 2016.
Article in English | WPRIM | ID: wpr-77739

ABSTRACT

A method for simultaneously identifying antioxidative compounds was developed using time-based LC-MS coupled with DPPH assay regardless of the time consuming process. The methanolic extract of Polygonum aviculare (Polygonaceae) showed significant DPPH radical scavenging activity. Time-based DPPH assay for simultaneous identification of active compounds from the extracts of P. aviculare was used. Major peaks of ethyl acetate fraction of P. aviculare showed high DPPH radical scavenging activity. A simple phenolic compound (1) and six flavonoids (2-7) were isolated from the ethyl acetate fraction of P. aviculare by silica gel and sephadex LH-20 column chromatography. The structures of seven compounds were determined to be protocatechuic acid (1), catechin (2), myricitrin (3), epicatechin-3-O-gallate (4), avicularin (5), quercitrin (6), and juglanin (7) based on the analysis of the 1H-NMR, 13C-NMR and ESI-MS data. All compounds exhibited significant antioxidant activity on DPPH assay and active compounds were well correlated with predicted one.


Subject(s)
Catechin , Chromatography , Flavonoids , Methanol , Phenol , Polygonum , Silica Gel
16.
Natural Product Sciences ; : 231-236, 2015.
Article in English | WPRIM | ID: wpr-184526

ABSTRACT

Two new azaphilone derivatives containing 1,3-dioxolane moiety, penidioxolanes A (1) and B (2), were isolated from marine-derived fungus Penicillium sp. KCB12C078, together with four known compounds (3-6) by chemical investigation. Compounds 1 - 6 were isolated by combination of silica gel, ODS column chromatography and preparative HPLC. Their structures were determined by analysis of spectroscopic data including 1D-, 2D-NMR, and MS techniques. The isolates were evaluated against cancer cell growth inhibition effects and antimicrobial activity.


Subject(s)
Chromatography , Chromatography, High Pressure Liquid , Fungi , Penicillium , Silica Gel
17.
International Journal of Oral Biology ; : 79-83, 2015.
Article in Korean | WPRIM | ID: wpr-104525

ABSTRACT

The purpose of the study was to investigate the antimicrobial activity of the methanol extract of Coptidis rhizome against the type strains of cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus, and the periodontopathogens, Porphyromonas gingivalis, Prevotella intermedia, Treponema denticola and Aggregatibacter actinomycetemcomitans. The antimicrobial activities of the crude extract and the methanol extract fractions of Coptidis rhizome separated by silica gel chromatography were evaluated by determining the minimal bactericidal concentration (MBC) values, using the microdilution method. The cell viability test of the extracts of Coptidis rhizome on the KB cells was also studied by methyl thiazolyl tetrazolium (MTT) assay. Our results showed that the 11th fraction (F11) of the methanol extract had the greatest antimicrobial activity against the tested bacteria, with no associated cytotoxicity on the KB cells, upto a concentration of 50 microg/ml. These results suggest that the silica gel chromatography fraction F11 of the methanol extract of Coptidis rhizome, could be useful in the development of oral hygiene products as an antimicrobial agent for the prevention of dental caries and periodontal diseases.


Subject(s)
Humans , Aggregatibacter actinomycetemcomitans , Bacteria , Cell Survival , Chromatography , Dental Caries , KB Cells , Methanol , Oral Hygiene , Periodontal Diseases , Porphyromonas gingivalis , Prevotella intermedia , Rhizome , Silica Gel , Streptococcus mutans , Streptococcus sobrinus , Treponema denticola
18.
Natural Product Sciences ; : 255-260, 2015.
Article in English | WPRIM | ID: wpr-7750

ABSTRACT

Two new thiodiketopiperazines (TDKPs), designated graphiumins I (1) and J (2), were isolated from the culture broth of the marine-derived fungus Graphium sp. OPMF00224 by solvent extraction, silica gel column chromatography, and HPLC. Their absolute structures were elucidated by spectroscopic analyses (1D and 2D NMR data, ROESY correlations, and CD data) and chemical methods. They were found to be structurally rare TDKPs with a phenylalanine-derived indolin substructure. Compounds 1 and 2 inhibited yellow pigment production by methicillin-resistant Staphylococcus aureus (MRSA) with IC50 values of 63.5 and 76.5 microg/ml, respectively, without inhibiting its growth, even at 250 microg/ml.


Subject(s)
Chromatography , Chromatography, High Pressure Liquid , Fungi , Inhibitory Concentration 50 , Methicillin-Resistant Staphylococcus aureus , Silica Gel
19.
Korean Journal of Anesthesiology ; : 274-280, 2015.
Article in English | WPRIM | ID: wpr-67425

ABSTRACT

BACKGROUND: During general anesthesia, a heated breathing circuit (HBC) is used to replace the heat and moisture exchange function of the upper airway. One HBC uses an air dryer filter that employs silica gel (SG) as a desiccant. SG is capable of adsorbing many organic compounds. Therefore, we undertook an in vitro study of the adsorption of desflurane by SG filters. METHODS: An HBC was connected to an anesthesia machine, and a test lung was connected to the circuit. The test lung was mechanically ventilated with 2 or 4 L/min of fresh gas flow, with and without the air dryer filter. Desflurane was administered at a 6 vol% on the vaporizer dial setting. The experiment was repeated 15 times in each group. The end-tidal concentrations were measured during the experiments. The air dryer filter weights were measured before and after the experiments, and the times required to achieve the specific end-tidal desflurane concentrations were determined. RESULTS: Significant differences in the end-tidal concentrations of desflurane were observed between the control and filter groups (P < 0.001). The filter weights increased significantly after the experiments (P < 0.001). The times required to achieve the same end-tidal desflurane concentrations were different with the application of the air dryer filter (P < 0.001). CONCLUSIONS: The adsorption of desflurane with the use of an air dryer filter was verified in this in vitro study. Careful attention is needed when using air dryer gel filters during general anesthesia.


Subject(s)
Adsorption , Air Filters , Anesthesia , Anesthesia, General , Desiccation , Hot Temperature , Lung , Nebulizers and Vaporizers , Respiration , Silica Gel , Weights and Measures
20.
Mycobiology ; : 59-65, 2014.
Article in English | WPRIM | ID: wpr-730020

ABSTRACT

Entomopathogenic fungi are promising pest-control agents but their industrial applicability is limited by their thermosusceptibility. With an aim to increase the thermotolerance of Isaria fumosorosea SFP-198, moisture absorbents were added to dried conidial powder, and the relationship between its water potential and thermotolerance was investigated. Mycotized rice grains were dried at 10degrees C, 20degrees C, 30degrees C, and 40degrees C and the drying effect of each temperature for 24, 48, 96, and 140 hr was determined. Drying for 48 hr at 10degrees C and 20degrees C reduced the moisture content to < 5% without any significant loss of conidial thermotolerance, but drying at 30degrees C and 40degrees C reduced both moisture content and conidial thermotolerance. To maintain thermotolerance during storage, moisture absorbents, such as calcium chloride, silica gel, magnesium sulfate, white carbon, and sodium sulfate were individually added to previously dried-conidial powder at 10% (w/w). These mixtures was then stored at room temperature for 30 days and subjected to 50degrees C for 2 hr. The white carbon mixture had the highest conidial thermotolerance, followed by silica gel, magnesium sulfate, and then the other absorbents. A significant correlation between the water potential and conidial thermotolerance was observed in all conidia-absorbent mixtures tested in this study (r = -0.945). Conidial thermotolerance in wet conditions was evaluated by adding moisturized white carbon (0~20% H2O) to conidia to mimic wet conditions. Notably, the conidia still maintained their thermotolerance under these conditions. Thus, it is evident that conidial thermotolerance can be maintained by drying mycotized rice grains at low temperatures and adding a moisture absorbent, such as white carbon.


Subject(s)
Calcium Chloride , Carbon , Edible Grain , Fungi , Magnesium Sulfate , Silica Gel , Sodium , Spores, Fungal , Water
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