Simultaneous determination of six aniline compounds in workplace air by high performance liquid chromatography / 中国职业医学

Objective To establish a high performance liquid chromatography (HPLC) method for simultaneous determination of six aniline compounds (ADs) in workplace air. Methods GDH-1 air sampling tube was used to collect six co-existing ADs such as aniline, o-toluidine, N-methylaniline, m-methylaniline, p-methylaniline and N,N-dimethylaniline in the vapor and aerosol of workplace air. The samples were desorbed and eluted using a methanol solution containing 1.00% ammonia water, followed by separation on a C18 chromatographic column and detection using a diode array detector. Results The quantification range of the method was 0.19 -253.50 mg/L, with the correlation coefficient of 0.999 9 for all six ADs. The minimum detection range was 0.02-0.06 mg/m3, and the minimum quantitation range was 0.04-0.19 mg/m3 [both calculated for a 15.0 L sample with a desorption (elution) solution volume of 3.00 mL]. The average desorption and elution efficiencies were 92.15%-104.41% (silica gel) and 94.29%-104.29% (filter membrane). The intra-assay relative standard deviation (RSD) ranged from 0.90%-9.72% (silica gel) and 0.57%-6.96% (filter membrane). The inter-assay RSD ranged from 2.03%-9.78% (silica gel) and 2.50%-8.62% (filter membrane). The samples were stable at room temperature for seven days. Conclusion This method can be used for the simultaneous determination of six ADs in workplace air.

Fadiga deslizante em restaurações de zircônia translúcida submetidas a diferentes acabamentos de superfície: probabilidade de sobrevivência e potencial de desgaste / Sliding contact fatigue in translucent zirconia restorations submitted to different surface finishes: survival probability and wear potential

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.

Modeling of lactose enzymatic hydrolysis using Monte Carlo method

Background: Mathematical modeling is useful in the analysis, prediction, and optimization of an enzymatic process. Unlike the conventional modeling methods, Monte Carlo method has special advantages in providing representations of the molecule's spatial distribution. However, thus far, Monte Carlo modeling of enzymatic system is namely based on unimolecular basis, not suitable for practical applications. In this research, Monte Carlo modeling is performed for enzymatic hydrolysis of lactose for the purpose of real-time applications. Results: The enzyme hydrolysis of lactose, which is conformed to Michaelis­Menten kinetics, is modeled using the Monte Carlo modeling method, and the simulation results prove that the model predicts the reaction kinetics very well. Conclusions: Monte Carlo modeling method can be used to model enzymatic reactions in a simple way for real-time applications.

The advance of materials for preventing adhesion in tympanoplasty / 中华耳鼻咽喉头颈外科杂志

For otitis media patients with severe mucosal lesions, adhesion is the most common poor prognosis of tympanoplasty. We generally consider tympanic cavity adhesion is due to eustachian tube dysfunction and poor middle ear ventilation. The mechanism of adhesion is unclear so far, which we thought is mainly associated with wounded surface and activation of the fibrinolytic system. To solve the problem of adhesion, several materials have been used in the middle ear surgery, such as plastic sheet, silicone sheet and absorbable material. And there are some benefits. The most widely used is silicone sheet, and there are some researches focused on its thickness, shape and components to achieve better anti-adhesion effect. In this article, we will do a review for the research advances of anti-adhesion materials in tympanoplasty.

Clinical effects of Dermatix Ultra silica gel and asiaticoside cream on hyperplastic scar tissue in patients after epicanthoplasty / 中华医学美学美容杂志

Objective@#To observe the clinical efficacy of Dermatix Ultra silica gel and asiaticoside cream for the treatment or repair of scar hyperplasia which was external used in internal corner incision of patients after the internal canthus correction operation.@*Methods@#A total of 90 patients were randomly chosen and divided into three groups. All patients with epicanthus were treated with the same internal canthus correction method by one doctor. There were 30 patients in each group: 30 cases in the control group were treated without any medication, and the postoperative incision healed naturally; 30 cases were treated with Dermatix Ultra silica gel; 30 cases were treated with asiaticoside cream. Patient and observer scar assessment scale (POSAS) was used as the end points to evaluate the clinical efficacy of Dermatix Ultra silica gel and asiaticoside cream 4 weeks and 12 weeks after the operation. The satisfactory degree from all the patients were collected after 6 months follow-up and we compared the scores of three groups.@*Results@#Compared with the control group, the POSAS scores in Dermatix Ultra silica gel group and asiaticoside cream group were low (P<0.05) at 4 weeks and 12 weeks after operation. At 4 weeks after operation, the POSAS score in Dermatix Ultra silica gel group was lower than that in the asiaticoside cream group (P<0.05). At 12 weeks after operation, there was no significant difference in POSAS score between Dermatix Ultra silica gel group and asiaticoside cream group (P>0.05). Follow-up for 6 months, the satisfaction degree of patients in Dermatix Ultra silica gel group and asiaticoside cream group was higher than in the control group (P<0.05); the satisfactory degree of patients in Dermatix Ultra silica gel group was higher than that in asiaticoside cream group (P<0.05).@*Conclusions@#Dermatix Ultra silica gel and asiaticoside cream have good clinical effects in repair of scar tissue after the epicanthoplasty. Dermatix Ultra silica gel is better than asiaticoside cream in scar early improvement.

Changes of macrophages phenotype markers in fibrous capsules around silicone implants / 中华医学美学美容杂志

Objective To study the temporal distribution of macrophage and its phenotype markers in fibrous capsules around silicone implants.Methods Thirty rats were randomly divided into five groups:days 1,3,7,14 and 35.Silicone prostheses (10 ml) were implanted subcutaneously into backs of rats.On each indicated day,the tissue specimens were collected,fixed in 4％ paraformaldehyde for 24 hours and embedded in paraffin.Immunofluorescence was used to detect temporal distribution of M1/M2 macrophages.Results The number of CD68+ macrophages at day 1 (65.8±12.9) was smaller than that at day 3 (102.8±14.5,P＜0.05) and day 7 (116.8±14.2,P＜0.05);and the number of CD68+ macrophages at day 7 was larger than that at day 14 (56.8±12.9,P＜0.05) and day 35 (21.40±6.35,P＜0.05);the proportion of iNOS+ CD68+ M1 cells at day 1 and day 3 was 0.48±0.13,0.60±0.13,respectively,and they were higher than that at day 7 (0.21±0.03,P＜0.05),day 14 (0.21±0.03,P＜0.05) and day 35 (0.17±0.04,P＜0.05);the proportions of CD206+ CD68+ M2 cells at day 1,day 3,day 7,day 14,day 35 were 0.70±0.06,0.60±0.07,0.70±0.08,0.67±0.02 and 0.60±0.06,respectively.Conclusions After the implantation of silicone prostheses,M1 cells increase in early stages and M2 cells maintain in high level throughout the experiment period.

Efeito de infiltrações de sílica pelo método sol-gel em uma zircônia odontológica: microestrutura, propriedades mecânicas, resistência de união e energia interfacial para fratura / Effect of silica infiltrations by the sol-gel method on a dental zirconia: microstructure, mechanical properties and interfacial fracture energy

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)

Adsorption Property of Avilamycin on Silica Gel-based Absorbent / 中国药学杂志

OBJECTIVE: To investigate the kinetic and thermodynamic characteristics of adsorption of avilamycin on silica gel. METHODS: By measuring the adsorption of avilamycin on silica gel at different temperatures, the adsorption kinetics curves and adsorption isotherm were drawn, and the kinetics and thermodynamic parameters were studied. RESULTS: The adsorption of avilamycin on silica gel could be described well by Pseudo-second-order model. The adsorption process had feature of shrinking nonreactive core model, and the internal diffusion was the main rate-limiting step. The equilibrium adsorption data of avilamycin on silica gel fit the Langmuir isotherms well. The thermodynamic parameters were as follows:change in entropy (ΔS) was 108.115 2 J·mol-1·K-1, change in enthalpy (ΔH) was 24.654 6 J·mol-1, and changes in free energy (ΔG) were -8.752 9, -8.104 3, and -7.455 6 J·mol-1 at 309, 303 and 297 K, respectively. CONCLUSION: The RESULTS: of this study provide a theoretical basis for further study on the isolation and purification of high purity avilamycin by silica gel.

Preparation of galangin molecular imprinted polymers on silica gel surface and its adsorption properties / 中草药

Objective To prepare surface molecular imprinted polymers (MIP) of galangin by using surface molecular imprinting technique. Methods Galangin MIP was prepared by surface polymerization method at the surface of silica gel, which was modified with (3-aminopropyl) trimethoxysilane, by using galangin as the template molecule, methacrylic acid (MAA) as the functional monomer, and N,N′-methylenebisacrylamide (MBA) as crosslinking agent. The polymer was characterized by infrared spectroscopy and scanning electron microscopy. And its adsorption properties were studied by static and competitive adsorption method. Results The experimental research showed that the optimal preparation condition was that the molar ration of galangin to MAA was 1∶4, with molar ration of MAA to MBA 1∶7, reaction temperature 40 ℃ and reaction time 12 h. Infrared spectrum and scanning electron microscopy showed that MIP was successfully grafted on the surface of silica gel, and recognition holes and sites selectively appeared for galangin molecules. Adsorption experiments exhibited that MIP had specific recognition and good affinity for galangin molecules. Compared to the controls of breviscapine and luteolin, the selectivity coefficients of MIP to galangin were 11.2 and 5.3, respectively. Conclusion MIP has good recognition and high selectivity for galangin, which provides a new method for the separation and extraction of flavonoids from Chinese medicine.

Fabrication and pre-clinical application of patient-specific 3D silicone rubber bolus for chest wall / 中华放射肿瘤学杂志

Objective To apply 3D printing technology to fabricate patient-specific silicone tissue compensators for the chest wall and compare the advantages and clinical characteristics between conventional bolus and 3D-printed PLA materials. Methods The chest wall data of two breast cancer patients undergoing mastectomy were obtained based upon the CT images. A patient-specific 3D printing silicone rubber bolus (3D-SRB) was designed and fabricated. The conformability of 3D-SRB,3D-PLA and conventional bolus to the chest wall were validated. Ecipse8. 6 planning system was adopted to statistically compare the dosimetric parameters of virtual plan with those after using three tissue compensators. Results The 3D-SRB was successfully designed and fabricated with a similar hardness to conventional bolus. During the process of validating conformability and radiotherapy planning,3D-SRB and 3D-PLA were superior to conventional bolus in terms of conformability to chest wall and planning dosimetric distribution.3D-SRB was advantageous in repeatability, conformability and comfortable experience compared with 3D-PLA. Regarding dosimetric parameters,3D-SRB yielded the highest repeatability with the virtual plan, followed by 3D-PLA and conventional bolus. Conclusion It is applicable to utilize 3D-SRB as the patient-specific compensators for the chest wall,which is of significance in clinical practice.

Effects of Non-ionic Polyacrylamide Alone or Combined with Nanoscale Silica Gel on the Stability of Glycyrrhetinic Acid Lipo-emulsion / 中国药房

OBJECTIVE:To investigate the effects of non-ionic polyacrylamide(model:NPAM 1400)alone or combined with nanoscale silica gel (nSiO2) on the stability of Glycyrrhetinic acid lipo-emulsion. METHODS:UV-spectrophotometer was used to determine absorbance of diluent at 500 nm before and after lipo-emulsion centrifugation. Using the preparation without stable excipient as blank,stability coefficient (KE) and it ratio (KE/KE blank) were calculated. Effects of different concentrations (200-600 mg/L) of non-ionic polyacrylamide on the stability of Glycyrrhetinic acid lipo-emulsion were evaluated. The optimal concentration of non-ionic polyacrylamide alone was determined primarily,and then the effects of it combined with different concentrations of hydrophilic nSiO2 (0.2％, 0.3％, 0.4％) or hydrophobic (0.2％, 0.3％, 0.5％) on the stability of Glycyrrhetinic acid lipo-emulsion were investigated. RESULTS:When adding non-ionic polyacrylamide alone,KE of Glycyrrhetinic acid lipo-emulsion mixed with 300 mg/L non-ionic polyacrylamide was the lowest,KE/KE blank was 0.22;when combined,KE of Glycyrrhetinic acid lipo-emulsion mixed with 300 mg/L non-ionic polyacrylamide and 0.2％ hydrophobic nSiO2 was the lowest,KE/KE blank was 0.27. CONCLUSIONS:Non-ionic polyacrylamide alone or combined with nSiO2 all can promote the stability of Glycyrrhetinic acid lipo-emulsion,among which 300 mg/L non-ionic polyacrylamide alone is the best.

Microplate silica allochroic gel assay for detecting rifampicin resistance of Mycobacterium tuberculosis / 重庆医学

Objective To discuss the clinical application value of microplate allochroic silica gel assay for rapidly detecting rifampicin(RIF)-resistance of Mycobacterium tuberculosis(MTB).Methods Fifty MTB clinical isolates preserved in the tuberculosis(TB) laboratory of Nantong Municipal Sixth People's Hospital were detected RIF-resistance by using the microplate allochroic silica gel assay and compared with the Bactec MGIT960 method.Then,the RIF susceptibility test in 40 clinical sputum smear-positive specimens were simultaneously detected by using the microplate allochroic silica gel assay and Bactec MGIT960.Finally the sensitivity,specificity and accuracy of the test results were compared.Results The optimal inoculation volume of MTB was 10-3 mg/mL,the optimal detection time was 7-10 d and the judging critical value of the RIF minimum inhibitory concentration(MIC) Was 1.00 μg/mL by microplate allochroic silica gel assay.With the Bactec MGIT960 test as the gold standard,the sensitivity,specificity and accuracies of microplate allochroic silica gel assay for RIF-resistance susceptibility test of smear-positive specimens were 94.12％,100％ and 97.37％ respectively.Conclusion Microplate Allochroic silica gel assay can be used for directly detecting the MTB sensitivity to RIF of in sputum specimens.

Tolerance of Coffea arabica L. seeds to sub zero temperatures / Tolerância de sementes de Coffea arabica L. à temperaturas sub zero

ABSTRACT Preservation of the quality of coffee seeds is hindered by their intermediate behavior in storage. However, long-term storage at sub zero temperatures may be achieved by adjusting the water content of the seeds. The aim of this study was to evaluate the tolerance of coffee seeds to freezing, in relation to physiological and enzymatic modifications. Coffee seeds were dried in two manners, rapid and slow, to water contents of interest, 0.67, 0.43, 0.25, 0.18, 0.11, and 0.05 g H2O g-¹ dw (dry basis). After drying, the seeds were stored at a temperature of -20 ºC and of 86 ºC for 24 hours and for 12 months, and then compared to seeds in cold storage at 10 ºC. The seeds were evaluated through calculation of percentage of normal seedlings, percentage of seedlings with expanded cotyledonary leaves, dry matter of roots and of hypocotyls, and viability of embryos in the tetrazolium test. Expression of the enzymes superoxide dismutase, catalase, and peroxidase were evaluated by means of electrophoretic analysis. Only seeds dried more slowly to 0.18 g H2O g-1 dw present relative tolerance to storing at -20 °C for 12 months. Coffee seeds do not tolerate storage at a temperature of -86 ºC for 12 months. Water contents below 0.11g H2O g-¹ dw and above 0.43 g H2O g-¹ dw hurt the physiological quality of coffee seeds, regardless of the type of drying, temperature, and storage period. Coffee seed embryos are more tolerant to desiccation and to freezing compared to whole seeds, especially when the seeds are dried to 0.05 g H2O g-¹ dw. The catalase enzyme can be used as a biochemical marker to study tolerance to freezing in coffee seeds.

RESUMO A preservação da qualidade de sementes de café é dificultada pelo comportamento intermediário no armazenamento. Porém, a conservação a longo prazo em temperaturas subzero pode ser conseguido com o ajuste do teor de água das sementes. Objetivou-se neste trabalho avaliar a tolerância de sementes de café ao congelamento, com relação às modificações fisiológicas e enzimáticas. As sementes foram submetidas a dois tipos de secagem, rápida e lenta, até os teores de água de interesse, de 0,67, 0,43, 0,25, 0,18, 0,11, 0,05 g H2O g-¹ dw (base seca). Após secagem, as sementes foram armazenadas em temperatura de -20 e de -86 ºC, por 24 horas e por 12 meses, sendo comparadas às sementes armazenadas em câmara fria a 10 ºC. As sementes foram avaliadas pela porcentagem de plântulas normais, plântulas com folhas cotiledonares expandidas, matéria seca de raízes e de hipocótilos e viabilidade dos embriões no teste de tetrazólio. A expressão das enzimas superóxido dismutase, catalase e peroxidase foi avaliada por meio de análise eletroforética. Apenas as sementes secadas lentamente até 0,18 g H2O g-¹ dw apresentam relativa tolerância ao armazenamento a -20 °C por 12 meses. Sementes de café não toleram o armazenamento à temperatura de -86 ºC por 12 meses. Umidades abaixo de 0,11g H2O g-¹ dw e acima de 0,43 g H2O g-¹ dw são prejudiciais à qualidade fisiológica das sementes de café, independentemente do tipo de secagem, temperatura e período de armazenamento. Embriões de sementes de café são mais tolerantes à dessecação e ao congelamento quando comparado às sementes inteiras, principalmente quando as sementes são secadas até 0,05 g H2O g-¹ dw. A enzima catalase pode ser usada como um marcador bioquímico para estudar a tolerância de sementes de café ao congelamento.

Efeito da bioinspiração e infiltração de zircônia por sílica nas propriedades mecânicas de bicamadas cerâmicas / MIcrostructural analysis and fatigue strength of monolithic zirconia simulating adjustment protocols

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)

Rapid detection on resistance of pyrazinamide for Mycobacterium tuberculosis by microplate allochroic silica gel assay / 国际检验医学杂志

Objective To establish a method of judge the pyrazinamide(PZA) susceptibility for Mycobacterium tuberculosis(MTB) with 24-hole micro-liquid culture silica gel color plate,and evaluate the clinical application value of this method.Methods According to the result of MGIT960,to detect PZA drug susceptibility for 30 MTB clinical isolates of whose PZA susceptibility were known with silica gel color plate.The effects of different pH value,different inoculation concentrations on the results were observed,and the optimum detection conditions were discussed.Finally,the 98 MTB clinical isolated of whose PZA susceptibility were unknown were simultaneously detected by gel color plate and MGIT960,the sensitivity,specificity and accuracy were judged by PZA drug sensitivity.Results The best pH was 5.8-5.9 and the best concentration was 2.5×10-1 mg/mL in gel color plate.The best results were read after 7-14 d.The sensitivity,specificity and accuracy were 95.50%,96.30%,and 98.21% respectively just at PZA critical concentration was 100 μg/mg.The sensitivity,specificity and accuracy were 90.90%,92.59%,and 91.84% respectively just at PZA critical concentration was 200 μg/mg.Conclusion The PZA susceptibility for MTB with 24-hole micro-liquid culture silica gel color plate is accurate,rapid,low-cost and simple.

Clinical study on the treatment of lacrimal duct obstruction with lomefloxacin hydrochloride eye ophthalmic gel / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To study the clinical effect of silica gel drainage tube combined with lomefloxacin hydrochloride eye ophthalmic gel in the treatment of lacrimal duct obstruction.METHODS:Totally 86 cases (138 eyes) of lacrimal duct embolism treated in our hospital from February to December 2015 were divided into 43 cases (68 eyes) as control group and 43 cases (70 eyes) of the observation group according to whether they were treated with lomefloxacin hydrochloride eye ophthalmic gel.Patients in the control group were treated with silica gel drainage, while the observation group was treated with lomefloxacin hydrochloride eye ophthalmic gel on the basis of the control group.The total effective rate, serum hypersensitivity C-reactive protein (h-CRP) level, complications and recurrence rate were observed and compared between the two groups.RESULTS:The total effective rate in the patients with obstructive nasolacrimal duct, common lacrimal duct obstruction, and lacrimal duct obstruction in observation group were 95.2%, 100.0%, 96.7%, higher than those in control group (P0.05).The serum levels of h-CRP in patients in the observation group at 3d and 7d after operation respectively were 2.40±0.84g/mL, 1.94±0.84g/mL, lower than those of control group at the same time (P<0.05).The complication rate of the observation group was 1.4%, which was lower than that of the control group (P<0.05).Follow up for 6-18mo, the recurrence rate was 11.4% in the observation group, which was significantly lower than the control group (P<0.05).CONCLUSION:The combination of silica gel drainage tube and lomefloxacin hydrochloride eye ophthalmic gel in the treatment of obstruction of lacrimal duct has good clinical efficacy, low inflammatory reaction, low complication rate and low recurrence rate.

Protopanaxadiol ginsenosides dynamics in enzymatic reaction and preparation of rare ginsenosides / 中草药

Objective: To cheaply prepare the rare ginsenosides by biotransformation, ginsenosides C-K, C-Mc, F2, and Rh2 from commercially available Protopanaxadiol (PPD) ginsenoside mixture were prepared using a crude enzyme of Aspergillus g.848 strain. Methods: The rare ginsenosides were obtained from PPD ginsenosides by enzyme reaction; The composition of PPD raw materials and ginsenoside products was measured by HPLC. The monomer ginsenosides and Rh2 group of enzyme reaction product were separated by a silica gel column; The produced monomer ginsenosides were identified by NMR; Rh2 group was identified by UPLC-MS. Results: The raw material of PPD ginsenosides was consisted of ginsenoside Rb1, Rd, Rb2, Rc, and Rg3 groups with four kinds of isomers. During the reaction of enzyme, the best reaction time for the ginsenoside F2 production was 1.5 h to 2 h; The best reaction time for the ginsenoside C-K production was 24 h to 30 h; If producing the Rh2 group, when reacted to 6 h to 12 h, the content of Rg3 group was low, and Rh2 group was high. In the production of C-K, 20 g of crude products were obtained from 30 g of PPD ginsenosides by enzyme reaction, and 8.16 g of C-K, 1.01 g of C-MC, 0.45 g of F2, and 0.19 g of Rh2 group were separated using silica gel column. The rare ginsenosides were identified by NMR, and the Rh2 group was identified using UPLC-MS method. Conclusion: The high activity of monomer ginsenoside C-K, C-Mc, F2, and Rh2 group are successfully prepared from the PPD ginsenosides by enzymatic conversion.

Separation and preparation of epimers physanicantriol and 14-epi-physanicantriol from the leaves of Artemisia argyi / 国际药学研究杂志

Objective To establish a method for the preparative separation and isolation of the epimeric labdenetriols,phy?sanicantriol(1)and 14-epi-physanicantriol(2),from the leaves of Artemisia argyi.Methods The CH2Cl2fraction of 95% EtOH ex?tract from the leaves of A.argyi was separated by Diaion HP-20,silica gel and Sephadex LH-20 column chromatography and purified by semi-preparative HPLC to obtain an epimeric mixture of 1 and 2.Then,the epimeric mixture was separated by silica gel H column chromatography with eluting by n-hexane-CH2Cl2-isopropyl alcohol(1:1:0.15,V/V/V)to obtain compounds 1 and 2.The structures of 1 and 2 were identified by comparing MS and NMR data with those reported in the literature.Results and Conclusion Two diterpe?noids were isolated for the first time from the family Compositae.This method is effective,convenient and rapid,and is suitable for the separation and preparation of the epimers 1 and 2.