Advantage analysis of flow-through cell method in quality evaluation of Chinese patent medicine: a case study of Danshen Tablets / 中国中药杂志

To explore the quality consistency evaluation method for multi-component traditional Chinese medicine and establish a dissolution evaluation method suitable for the characteristics of multi-component Chinese patent medicine, this study discussed the characteristics and advantages of the flow-through cell method in the dissolution evaluation of Chinese patent medicine by comparing the impact of the small cup method and the flow-through cell method on the dissolution behavior of water-soluble and lipid-soluble major active components of Danshen Tablets. Dissolution tests were performed using the small cup method as described in the 2020 edition of the Chinese Pharmacopoeia and the newly introduced flow-through cell method(closed-loop method) with water solution containing 0.5% SDS as dissolution medium. Cumulative dissolution curves of the water-soluble component salvianolic acid B and the lipid-soluble component tanshinone Ⅱ_A in Danshen Tablets were plotted, and fitting and similarity analysis of the dissolution models was conducted to identify the characteristics and advantages of the flow-through cell method. For the small cup method, 150 mL of water containing 0.5% SDS was used as the dissolution medium, with a rotation speed of 75 r·min~(-1) and a temperature of(37±0.5) ℃, and 3 mL of samples were taken at 15, 30 min, 1, 2, and 4 h, with fresh dissolution medium added at the same temperature and volume. For the flow-through cell method, a closed-loop system was used. Danshen Tablets were placed in the flow-through cell with approximately 6.7 g of glass beads, and 150 mL of water containing 0.5% SDS was used as the dissolution medium. The flow rate was set at 20 mL·min~(-1), and the temperature and sampling were the same as the small cup method. The results showed that compared with the small cup method, the flow-through cell method had stronger discriminative power and higher sensitivity in distinguishing the dissolution behavior of the two components, and could better reflect the differences in formulation quality, especially for water-insoluble lipid-soluble components. Given that there were no essential differences in the in vitro release kinetics between the two methods, the flow-through cell method could not only replace the traditional small cup method but also better guide the formulation development and identify quality issues of formulations.

Multilevel Survival Analysis of Factors Associated with Under-Five Mortality in Manipur

Background: Child mortality is a major public health issue. The studies on under‑five mortality that ignore the hierarchical facts mislead the interpretation of the results due to observations in the same cluster sharing common cluster‑level random effects. Objectives: The present study uses a multilevel model to analyze under‑five mortality and identify the significant factors for under‑five mortality in Manipur. Methods: National Family Health Survey‑5 (2019–21) data are used in the present study. Amultilevel mixed‑effect Weibull parameter survival model was fitted to determine the factors affecting under‑five mortality. We construct three‑level data, individual levels are nested within primary sampling units (PSUs), and PSUs are nested within districts. Results: Out of the 3225 under‑five children, 85 (2.64%) died. The three‑level mixed‑effects Weibull parametric survival model with PSUs nested within the districts, the likelihood‑ratio test with Chi‑square value = 10.98 and P = 0.004 < 0.05 indicated that the model with random‑intercept effects model with PSUs nested within the districts fits the data better than the fixed effect model. The four covariates, namely the number of birth in the last 5 years, age of mother at first birth, use of contraceptive, and size of child at birth, were found as the risk factor for under‑five mortality at a 5% level of significance. Conclusions: In the random‑intercept effect model, the two estimated variances of the random‑intercept effects for district and PSU levels are 0.27 and 0.31, respectively. The values indicate variations (unobserved heterogeneities) in the risk of death of the under‑five children between districts and PSUs levels.

Prediction of sulfamerazine and sulfamethazine solubility in some cosolvent mixtures using non-ideal solution models / Predicción de la solubilidad de sulfamerazina y sulfametazina en algunas mezclas cosolventes utilizando modelos de solución no ideales / Predição da solubilidade de sulfamerazina e sulfametazina em algumas misturas de cosolventes usando modelos de solução não ideais

SUMMARY Introduction: Experimental Solubilities of sulfamerazine (SMR) and sulfamethazine (SMT) in some (methanol + water), (ethanol + water) and (1-propanol + water) cosolvent mixtures were collected from the literature at five temperatures from 293.15 to 313.15 K. Methodology: The results were analyzed with the van't Hoff, Apelblat modified, Buchowski-Ksiazaczak λh, van't Hoff-Yaws model, two-parameter Weibull function model. It was determined that the models that best describe the solubility of these sulfonamides in (alcohol + water) mixtures were the van't Hoff and Apelblat models, obtaining correlation indices greater than 0.99 in all cases. Results: The results obtained with the Modified Apelblat equation presents a high correlation index for the solubility of SMR and SMT in cosolvent mixtures, followed by the van't Hoff-Yaws model that presents a high fit of the estimated data with respect to the theoretical ones. According to the two-parameter Weibull function model, the solubility ofSMR and SMT in the co-solvent mixtures shows important deviations from ideality, which is consistent with the literature. The results are discussed in terms of the solute-solvent interactions that occur in this system.

RESUMEN Introducción: Las solubilidades experimentales de la sulfamerazina (SMR) y la sulfametazina (SMT) en algunas mezclas cosolvents (metanol + agua), (etanol + agua) y (1-propanol + agua), se revisaron en la literatura a cinco temperaturas de 293,15 a 313,15 K. Metodología: Los resultados se analizaron con el modelo van't Hoff, Apelblat modificado, Buchowski-Ksiazaczak λh, van't Hoff-Yaws, y el modelo de la función Weibull de dos parámetros. Se determinó que los modelos que mejor describen la solubilidad de estas sulfonamidas en mezclas (alcohol + agua) son los modelos de van't Hoffy Apelblat, obteniendo índices de correlación superiores a 0,99 en todos los casos. Resultados: Los resultados obtenidos con la ecuación de Apelblat modiicada presentan un alto índice de correlación para la solubilidad de SMR y SMT en mezclas de cosolventes, seguido del modelo van't Hoff-Yaws que presenta un alto ajuste de los datos calculados con respecto a los teóricos. Según el modelo de la función de Weibull de dos parámetros, la solubilidad de la SMR y la SMT en las mezclas de cosolventes muestra importantes desviaciones de las ideales, lo que es coherente con la literatura. Los resultados se discuten en términos de las interacciones soluto-solvente que se producen en este sistema.

RESUMO Introdução: As solubilidades experimentais de sulfamerazina (SMR e sulfametazina (SMT) em algumas misturas de cossolventes (metanol + água), (etanol + água) e (1-propanol + água), foram revisadas na literatura em cinco temperaturas de 293,15 a 313,15 K. Metodologia: Os resultados foram analisados com o modelo van't Hoff, Apelblat modificado, Buchowski-Ksiazaczak λh, van't Hoff-Yaws e o modelo de função Weibull de dois parâmetros. Determinou-se que os modelos que melhor descrevem a solubilidade dessas sulfonamidas em misturas (álcool + água) são os modelos van't Hoff e Apelblat, obtendo índices de correlação superiores a 0,99 em todos os casos. Resultados: Os resultados obtidos com a equação de Apelblat modi-icada apresentam um alto índice de correlação para a solubilidade de SMR e SMT em misturas de cosolventes, seguido pelo modelo de van't Hoff-Yaws que apresenta um alto ajuste dos dados calculados em relação a teóricos. De acordo com o modelo de função Weibull de dois parâmetros, a solubilidade de SMR e SMT em misturas de cosolventes apresenta desvios signiicativos dos ideais, o que é consistente com a literatura. Os resultados são discutidos em termos das interações soluto-solvente que ocorrem neste sistema.

Research on Mathematical Distribution of Failure Time and Engineering Evaluation for Medical Electrical Equipment Based on Operation and Maintenance Data / 中国医疗器械杂志

This study mainly discusses the contents, methods and characteristics of the collection of operation and maintenance data, as well as the establishment and evaluation methods of the distribution model of the failure time of medical electrical equipment. The distribution models of failure time at three levels of medical electrical equipment are established by linear regression method and goodness of fit test:The first is the device level MTBF distribution model, the second is the failure rate distribution model of the failure mode of key components, the third is the calculation model of the influence coefficient of influence factor on the failure mode of key components. This study presents a method of establishing MTBF segment model and implements a calculation model of influence coefficient varying with time.

Estudio climatológico de los vientos para la ciudad de Bogotá en el periodo 2010 - 2016 / Climatological study of the winds for the city of Bogotá in the period 2010-2016 / Estudo climatológico dos ventos para a cidade de Bogotá no período de 2010 a 2016

Resumen En Colombia, hay una carencia en los estudios climatológicos del viento, ya que, los que existen actualmente no aplican técnicas estadísticas ni periodos representativos adecuados. Por consiguiente, el presente estudio analiza el comportamiento climatológico del viento en la ciudad de Bogotá, para el periodo 2010 a 2016, buscando describir estadística, espacial y vectorialmente esta variable climatológica. Para empezar se realizó un análisis estadístico del conjunto de datos, de la velocidad del viento, mediante el software Windographer©, utilizando las técnicas exploratorias para la distribución Weibull, describiendo así los parámetros estadísticos de las estaciones en las principales zonas de la ciudad. Del mismo modo, se elaboraron las rosas de los vientos por estación, con el software WRPLOT™; y para finalizar se realizó un mapa vectorial mediante el método de interpolación Co-Kriging utilizando el sistema de información geográfica ArcGis®. Observando que el régimen de circulación atmosférico en Bogotá está estrechamente relacionado con la presencia de los cerros orientales y con la predominancia de los vientos alisios; así mismo, se encontró que la mayor velocidad del viento se presenta al suroeste, y las magnitudes más débiles, al norte y en cercanía a los cerros orientales.

Abstract In Colombia, there is a lack in wind weather studies, since those that currently exist do not apply statistical techniques or adequate representative periods. Therefore, the present study analyzes the wind weather behavior in the city of Bogotá, for the period 2010 to 2016, seeking to describe this weather variable statistically spatially and vectorially. To begin with, a statistical analysis of the data set, of the wind speed, was performed using the Windographer© software, using the exploratory techniques for the Weibull distribution, thus describing the statistical parameters of the stations in the main areas of the city. Similarly wind roses were made per season, using the WRPLOT ™ software; and, finally, a vector map was made using the Co-Kriging interpolation method, using the ArcGis® geographic information system. Noting that the atmospheric circulation regime in Bogotá is closely related to the presence of the eastern hills and the predominance of trade winds; Likewise, it was found that the highest wind speed is presented to the southwest, and the weakest magnitudes, to the north and in proximity to the eastern hills.

Resumo Na Colômbia, há falta de estudos sobre o clima do vento, uma vez que os existentes atualmente não aplicam técnicas estatísticas ou períodos representativos adequados. Portanto, o presente estudo analisa o comportamento do clima eólico na cidade de Bogotá, no período de 2010 a 2016, buscando descrever esta variável climática de forma estatística, espacial e vetorial. Para começar foi realizada uma análise estatística do conjunto de dados, da velocidade do vento, utilizando o software Windographer©, utilizando as técnicas exploratórias para a distribuição de Weibull, descrevendo assim os parâmetros estatísticos das estacoes nas principais áreas da cidade. Da mesma forma, foram feitas rosas de vento por temporada, usando o software WRPLOT ™; e, finalmente, foi feito um mapa vetorial usando o método de interpolação Co-Kriging, usando o sistema de informação geográfica ArcGis®. Observando que o regime de circulação atmosférica em Bogotá está intimamente relacionado com a presença dos montes orientais e predominância de ventos alísios; da mesma forma, verificou-se que a maior velocidade do vento é apresentada na região sudeste, e as magnitudes mais fracas, ao norte e nas proximidades das colinas orientais.

Failure probability, stress distribution and fracture analysis of experimental screw for micro conical abutment

Abstract The aim of this study was to evaluate the failure probability of two types of abutment screws after compressive load and to analyze the stress distribution with finite element method. Sixty (60) single-tooth implant restorations were assembled on titanium implants (e-fix, A.S. Technology - Titanium Fix). The groups were divided into Conventional screw (Screw neck 1.5 ø mm) and Experimental screw (Screw neck constricted with 1.2 ø mm). Specimens were subjected to single load to failure with compressive test according ISO 14801. The fractured specimens were subjected to stereomicroscopy for measurement of remaining screws inside the implant and characterization of fracture origin. Representative specimens were analyzed by scanning electronic microscopy. For finite element method (FEM), an identical 3D model of the two in vitro test groups were used with similar conditions (30º, 100 N load). The stress in the abutment screw was analyzed by von-Mises criteria. The results of strength means were 4132.5 ± 76 MPa and 4528.2 ± 127.2 for conventional and experimental groups, respectively. During microscopy, the mean (mm) of the remaining screw piece inside the implants were 0.97 ± 0.23 and 1.32 ± 0.12 for conventional and experimental groups, respectively. In FEM, the conventional group showed stress concentered in an unfavorable region (peak of 39.23 MPa), while the experimental group showed more stress areas but less concentration than the conventional group (36.6 MPa). In using the tested experimental geometry, the abutment screw can have its strength improved, and the origin of failure can be more favorable to clinical resolution.

Resumo O objetivo deste estudo foi avaliar a probabilidade de falha de dois tipos de parafusos para pilar protético após a compressão e analisar a distribuição da tensão com o método dos elementos finitos. Sessenta (60) restaurações unitárias foram montadas em implantes de titânio (e-fix, A.S. Technology - Titanium Fix). Os grupos foram divididos em parafusos convencionais (parafuso de pescoço 1,5 ø mm) e parafuso experimental (parafuso de pescoço estreitado com 1,2 ø mm). As amostras foram sujeitas ao teste de compressão de acordo com ISO 14801. Os espécimes fraturados foram submetidos a estereomicroscopia para a mensuração dos parafusos restantes dentro do implante e caracterização da origem da fratura. Os espécimes representativos foram analisados ​​por microscopia eletrônica de varredura. Para o método de elementos finitos (FEM), utilizou-se um modelo 3D idêntico dos dois grupos de teste in vitro com condições semelhantes (30º, 100 N). A tensão no parafuso do pilar foi analisada pelo critério de von-Mises. Os resultados de resistência a compressão foram 4132,5 ± 76 MPa e 4528,2 ± 127,2 para grupos convencionais e experimentais, respectivamente. Durante a microscopia, a média do remanescente do parafuso restante dentro dos implantes foi de 0,97 ± 0,23 e 1,32 ± 0,12 mm para os grupos convencionais e experimentais, respectivamente. Em FEM, o grupo convencional mostrou tensão concentrada em uma região desfavorável (pico de 39,23 MPa), enquanto o grupo experimental apresentou mais áreas de tensão, porém menor concentração do que o grupo convencional (36,6 MPa). Ao usar a geometria experimental testada, o parafuso do pilar pode ter sua resistência melhorada e a origem da falha pode ser mais favorável à resolução clínica.

Determination of Dissolution of Inhaled Drugs by Paddle Apparatus Method / 中国药学杂志

OBJECTIVE: To develop a method for determination of the dissolution of inhaled drugs by using indacaterol maleate, ipratropium bromide and budesonide as model drugs, and explore the law of dissolution of inhaled drugs. METHODS: Samples were prepared and the improved paddle apparatus method (USP dissolution assay-fifth method) was used for dissolution experiment. Samples were taken at a certain time, and the drug concentration was determined by HPLC. The sample dispersion method, dissolution medium and membrane were optimized, meanwhile inhaled drugs with different properties were measured and dissolution curve was modeled. RESULTS: An improved paddle apparatus method for simulating drug dissolution in respiratory tract was developed, samples were collected using the new generation impactor and the dissolution parameters were determined to be as follows: 150 mL of dissolution medium (250 mL dissolution cup), 2% Tween 80-PBS dissolution medium, 4.5 cm watch glass (4.7 cm drug-loaded membranes and 4.7 cm mesh screen), glass microfiber filters, double-layer membranes, drug-loaded membrane fixation method (level the mesh screen) and sampling time of 3 h; Weibull model was suitable for fitting the three drugs with different solubility (r2>0.999 1). CONCLUSION: The method is simple and reproducible, and can be used to determine the dissolution of inhalation drugs; the dissolution process of inhaled drugs is consistent with Weibull model.

Evaluation of Dosage form Characteristics of Fuzi Lizhongwan Based on Dissolution Behavior / 中国实验方剂学杂志

Objective:Based on the previous studies, to investigate the dissolution behavior of Fuzi Lizhongwan by simultaneously determining the dissolution of benzoylmesaconine, benzoylaconine and benzoylhypaconine in Aconiti Lateralis Radix Praeparata. Method:The simultaneous determination of benzoylmesaconine, benzoylaconine and benzoylhypaconine in Fuzi Lizhongwan was established by HPLC-QQQ-MS. The dissolution amounts of three compositions in 15 batches of Fuzi Lizhongwan from 5 manufacturers at different time points, the cumulative dissolution was calculated and the dissolution curve was drawn. The f2 similarity factor method was adopted to evaluate similarity of dissolution curves of index components in different batches of samples from the same manufacturer, and to evaluate similarity of dissolution curves of samples from different manufacturers based on the same index component. The dissolution model of Fuzi Lizhongwan was concluded by fitting with the dissolution data. Result:When hydrochloric acid solution with pH of 1.2 was used as the dissolution medium, the three alkaloids had the best dissolution effect. The dissolution behavior of three monoester alkaloids in Fuzi Lizhongwan was basically synchronous and the dissolution lasted for 24 h. Three batches of samples from the same manufacturer (manufacturer 1, 3, 4 and 5) appeared to be similar on dissolution behavior, indicating that the dissolution behavior of the majority of samples from different manufacturers was similar. The dissolution behavior of batch 1 sample was different from batch 2 and 3 samples in manufacturer 2, suggesting that the quality of different batches of samples in manufacturer 2 might be different. The fitting results of dissolution data of index components in samples from different manufacturers were consistent, and the Weibull model was the best. Conclusion:Index components in fifteen batches of samples from 5 manufacturers are continuously dissolved within 24 h, indicating that the samples have the characteristics of slow dissolution. The dissolution curves of samples from the same manufacturer are similar to each other, indicating that the quality of different batches of products from most manufacturers is stable. The dissolution behavior of benzoylmesaconine, benzoylaconine and benzoylhypaconine in samples form different manufacturers has some differences, which may be caused by the source of medicinal materials and preparation technology parameters.

Simulation of Drying Process of Single Liuwei Dihuangwan and Analysis of Its Dynamics Based on Weibull Function / 中国实验方剂学杂志

Objective: Taking single Liuwei Dihuangwan(LDW) as the research object,the moisture content change and volumetric shrinkage characteristics in its drying process were investigated,which provided the theoretical basis for improving the drying efficiency of the pills and reducing the quality problems of the pattern pills,crusts and crack pills. Method: The drying characteristics of LDW at drying temperature of 50,75,100,125℃ were studied by constant temperature hot air drying and vacuum drying.Based on sphere model of Fick's second law and Arrhenius equation,the effective diffusion coefficient and activation energy of the drying process were obtained.The volumetric shrinkage characteristics of the pills during the drying process were studied by the projected area method.The Weibull function was used to fit the drying dynamics curve of single LDW. Result: Hot air drying and vacuum drying of LDW both belonged to the decreasing drying processes,and the time required to achieve the same moisture content in vacuum drying was shorter than that in hot air drying.The moisture ratio in the drying process of single LDW obeyed the Weibull function distribution(R2=0.994 5-0.999 7),the scale parameter(α) decreased with the increase of temperature,and drying temperature had significant influence on the shape parameter (β).The effective diffusion coefficients of hot air drying and vacuum drying were 2.626×10-3-7.823×10-2,3.782×10-3-9.042×10-2 m2·s-1, their activation energy were 47.18,42.69 kJ·mol-1,respectively.The volume ratio of hot air drying and vacuum drying of LDW ranged from 0.638 to 0.741 and 0.607 to 0.689,respectively. Conclusion: Weibull function can be adopted to predict the drying and dehydration law of LDW.Under the condition of low temperature drying,slow-down of shrinkage rate of the pills is helpful to prevent the formation of splitting pills,this study provides theoretical and technical basis for dying of LDW.

Far infrared drying characteristics and kinetics of Angelicae Sinensis Radix slices / 中草药

Objective: Taking Angelicae Sinensis Radix (ASR) slices as the research object, the far infrared drying characteristics and kinetic model of ASR slice were explored, which provided a theoretical basis for improving the quality of dry products and establishing a suitable processing method. Methods: The far-infrared drying technique was applied to the drying of ASR. The far-infrared drying characteristics and dry product quality of ASR were studied under different drying temperature, slice thickness and irradiation height, and the Weibull function was used to fit the drying curve. The quantitative relationship between test factors and model parameters were established. Results: With the increase of drying temperature and the decrease of the slice thickness and the irradiation height, the water ratio was decreased significantly, and the drying rate was increased significantly. The far-infrared drying process of the ASR slice obeyed the Weibull distribution function (R2 = 0.983 34-0.999 34, χ2 = 0.001 3-0.006 5), both the size parameter and the shape parameter were related to the drying temperature, slice thickness and irradiation height; The interval for estimating the water diffusion coefficient (Dcal) was 4.698 × 10-11-2.084 × 10-10 m2/s. The effective moisture diffusion coefficient (Deff) was in the range of 3.891 × 10-9-2.179 2 × 10-8 m2/s, both of which tended to increase with the increase of drying temperature, slice thickness and irradiation height. Compared with dry products from hot-hair drying, the color difference and water activity of far infrared drying were smaller, and it was easier to retain ferulic acid and volatile oil in ASR. Scanning electron microscopy analysis of the microstructure of dry products under different drying conditions showed that far infrared increased the interior of ASR slices. The number of micropores was increased, the cells were arranged more neatly, so as to increase the rate of thermal mass migration during the drying process and reduce the drying time. Conclusion: The Weibull distribution function can predict the water migration law of the drying process of ASR. It is of great significance for the prediction of the drying process of ASR and the process optimization.

Preparation, characterization and pharmacokinetics of dihydromyricetin phospholipids complex loaded by nanostructured lipid carriers / 中草药

Objective: To prepare dihydromyricetin (DMY) phospholipids complex (DMY-PC) and its nanostructured lipid carriers (DMY-PC-NLC), and carry out in vitro and in vivo evaluation. Methods: DMY-PC was prepared by solvent evaporation method. High pressure homogenization method was used to prepare DMY-PC-NLC. Orthogonal test was employed to optimize the ratio of solid/liquid lipid, dose of lipids materials, dose of DMY-PC and the concentration of emulsifier of poloxamer. The lyophilized powder of DMY-PC-NLC was prepared with 5% of mannitol as protective agent. The comparation of in vitro release and pharmacokinetics between DMY-PC and DMY-PC-NLC was also studied. Results: DMY was in an amorphous state in DMY-PC. The results of 1HNMR showed that the structure of DMY was not changed. The optimized prescription of DMY-PC-NLC determined by orthogonal test was as follow: The ratio of solid/liquid lipid was 5:1, dose of lipids materials was 325 mg, dose of DMY-PC was 45 mg and the concentration of emulsifier of poloxamer was 0.9%. The average size, Zeta potential, entrapment efficiency and drug loading of DMY- PC-NLC was (197.25 ± 4.42) nm, (-18.2 ± 2.1) mV, (71.68 ± 1.36)% and (3.94 ± 0.24)%, respectively. The in vitro release model was accord with Weibull model and the equation was lnln(1-Mt/M∞)=0.700 1 lnt-1.954 1 (r = 0.971 4). The relative bioavailability of DMY-PC and DMY-PC-NLC were enhanced to 1.63 and 3.22 times compared to DMY, respectively. Conclusion: Compared with DMY-PC, the absorption was promoted by DMY-PC-NLC in further, and the bioavailability of DMY was enhanced effectively.

Dissolution kinetics of Compound Danshen Tablets based on cell bioelectrical sensing effect / 中草药

Objective: Establishing the model of cell bioelectrical sensing effect of Compound Danshen Tablets to study its dissolution kinetics. Methods: By means of real-time cell-based assay, the in vitro dissolution of Compound Danshen Tablets can be investigated, and then the dissolution kinetics model can also be established. In addition, the result was compared and verified by UV-Vis. Results: The cell line with specific dependence on Compound Danshen Tablets was screened by CCK-8 experiment and RTCA experiment. The dissolution kinetics model of Compound Danshen Tablets based on RTCA technology was established, and the best fitting model was obtained: Weibull model ln{ln[1/(1-Q)] =1.071 4 lnt-3.736 7; Establish a dissolution kinetic model of Compound Danshen Tablets based on UV spectrophotometry to obtain the best fitting model, Weibull model ln{ln[1/(1-Q)]}=1.080 4 lnt-3.723 4; Comparing the two Weibull models, the RTCA fitted model worked better. Conclusion: The application of RTCA in the dissolution kinetics of traditional Chinese medicine compound solid preparations is feasible, Which provides new ideas for traditional Chinese medicines and the quality evaluation of traditional Chinese medicine compunds.

Study on Weibull function simulation and drying characteristics of Angelicae Sinensis Radix drying based on low temperature and resurgence conditions / 中草药

Objective: To clarify the effects of low temperature and dry in shade on the drying process of Angelicae Sinensis Radix (ASR), the drying and regain characteristics of ASR under low temperature drying and low temperature resurgence drying conditions were studied. Methods: Weibull distribution function and 1stOpt software were used to simulate the functional model of ASR under low temperature dry and low temperature (40, 55 ℃) resurgence conditions, analyze model parameters, drying curve, relative dry moisture regain, moisture effective diffusion coefficient (Deff), dry activation energy and other indicators, and compare the drying characteristics of ASR under low temperature dry and low temperature resurgence drying conditions. Results: Both low temperature drying and low temperature resurgence drying methods can make ASR dry, while low temperature resurgence drying method can greatly shorten the drying cycle of ASR, the Weibull function model and the linear regression fitting equation result meet the requirements. The Deff of ASR under low temperature drying conditions was 0.209 59 mm2/h, and the Deff under low temperature resurgence and drying conditions was between 4.489 40-4.566 90 mm2/h, the dry activation energy under low temperature drying condition was 80.75 kJ/mol. Conclusion: The low temperature resurgence drying method has obvious advantages over the traditional low temperature drying, this research can provide theoretical and technical basis for improving the traditional low temperature drying technology of ASR and establishing a new drying method suitable for the processing of ASR origin.

Study on low temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix based on Weibull distribution function / 中国中药杂志

The drying process of different grades of Angelicae Sinensis Radix under low temperature and resurgence conditions was simulated based on the Weibull distribution function,in order to clarify the low-temperature moisture regain drying characteristics of different grades of Angelicae Sinensis Radix,and explore the effect of grade and drying conditions on the drying process of Angelicae Sinensis Radix. Research results indicated that the Weibull function can be used to simulate different grades of Angelicae Sinensis Radix low-temperature moisture regain drying process,and the lower the drying temperature,the smaller the grade,and the better the simulation effect. The grade and drying temperature showed a significant effect on the low-temperature moisture regain drying process of Angelicae Sinensis Radix,and the effect of temperature on the relative moisture regain rate of Angelicae Sinensis Radix was greater than the grade. The relative moisture regain rate of different grades of Angelicae Sinensis Radix at 40 ℃ was higher than 55 ℃,and the relative moisture regain rate at 40 ℃ was first class > second class > third class. After drying,the moisture ratio at 40 ℃ was lower than that at 55 ℃; the effect of the grade on the effective diffusion coefficient of dry water was greater than the temperature. Under different conditions of 40 ℃ and 55 ℃ moisture regain,the effective diffusion coefficient of water was between 2. 941 6×10-6-7. 991 5×10-6 and3. 093 8×10-6-8. 483 8×10-6 for different grades. Under the same temperature conditions,the effective diffusion coefficient of water was first class > second class > third class. Therefore,Weibull function can be used to study and simulate the drying characteristics of different grades of Angelicae Sinensis Radix under low-temperature moisture regain conditions,providing experimental basis for the improvement of traditional drying technology of Angelicae Sinensis Radix and the optimization of drying process of different specifications or grades of Angelicae Sinensis Radix.

Inactivation of Alicyclobacillus acidoterrestris ATCC 49025 spores in apple juice by pulsed light: Influence of initial contamination and required reduction levels / Inactivación de esporas de Alicyclobacillus acidoterrestris ATCC 49025 por luz pulsada en jugo de manzana: Influencia de la contaminación inicial y de las reducciones requeridas

The purpose of this study was to analyze the response of different initial contamination levels of Alicydobadllus acidoterrestris ATCC 49025 spores in apple juice as affected by pulsed light treatment (PL, batch mode, xenon lamp, 3pulses/s, 0-71.6 J/cm²). Biphasic and Weibull frequency distribution models were used to characterize the relationship between inoculum size and treatment time with the reductions achieved after PL exposure. Additionally, a second order polynomial model was computed to relate required PL processing time to inoculum size and requested log reductions. PL treatment caused up to 3.0-3.5 log reductions, depending on the initial inoculum size. Inactivation curves corresponding to PL-treated samples were adequately characterized by both Weibull and biphasic models (R²d j 94-96%), and revealed that lower initial inoculum sizes were associated with higher inactivation rates. According to the polynomial model, the predicted time for PL treatment increased exponentially with inoculum size.

El objetivo del presente trabajo fue evaluar la influencia de la concentración de esporas de Alicyclobacillus acidoterrestris ATCC 49025 en la respuesta de inactivación por acción de la luz pulsada (modo estanco, lámpara de xenón, 3 pulsos/s, 0-71,6 J/cm²) en jugo de manzana comercial. Para caracterizar la relación existente entre la concentración de esporas y el tiempo de tratamiento con las reducciones logarítmicas alcanzadas luego de la exposición a la luz pulsada (LP), se aplicaron 2 modelos: el de Weibull y el bifásico. Adicionalmente, se estimó la relación entre el tiempo de tratamiento con LP y la concentración inicial de inoculo en el jugo con las reducciones logarítmicas logradas mediante regresión múltiple y la metodología de superficie de respuesta (MSR). La inactivación por LP provocó entre 3 y 3,5 reducciones logarítmicas, según la concentración inicial de esporas. Las curvas de inactivación fueron adecuadamente caracterizadas por los modelos matemáticos propuestos (Restado = 94-96%). El análisis por MSR permitió predecir un aumento exponencial del tiempo de tratamiento requerido conforme se incrementa el nivel de contaminación inicial.

Feldspar ceramic strength and the reinforcing effect by adhesive cementation under accelerated aging

Abstract This study evaluated the effect of the accelerated artificial aging (AAA) on feldspar ceramic strength and the reinforcing effect promoted by adhesive cementation with resin luting agent. One hundred twenty feldspar ceramic disks were obtained. Sixty disks were acid-etched, silanized, and coated with an experimental resin luting agent simulating the adhesive luting procedures. Four groups were created (n=30): uncoated ceramic (control group), uncoated ceramic submitted to AAA, ceramic coated with resin luting agent, and coated ceramic submitted to AAA. Biaxial flexural testing with ball-on-ring setup was carried out. Biaxial flexural strength (s bf , MPa), characteristic strength (s 0 , MPa), and Weibull modulus (m) were calculated for axial positions z=0 (ceramic surface) and z=−t2 (luting agent surface). Data of s bf at positions z=0 and z=-t2 were separately submitted to statistical analyses (a=0.05). The uncoated ceramic submitted to AAA had no significant difference in s bf and s 0 compared with the control group. Resin coating of the ceramic increased s bf and s 0 at z=0. The AAA increased the s bf and s 0 for the resin-coated ceramic specimens at z=0 and also the s 0 at axial position z=-t2. The structural reliability at z=0 and z=-t2 was not influenced by the variables tested. In conclusion, resin coating improved the mechanical strength of the feldspar ceramic. The AAA procedure was not effective in aging the uncoated or resin-coated feldspar ceramic specimens.

Resumo Este estudo avaliou o efeito do envelhecimento artificial acelerado (EAA) na resistência da cerâmica feldspática e o reforço promovido pela cimentação adesiva com cimento resinoso. Cento e vinte discos de cerâmica feldspática foram obtidos. Sessenta discos foram condicionados com ácido, silanizados, e recobertos com um cimento resinoso experimental simulando os procedimentos de cimentação adesiva. Quatro grupos foram criados (n=30): cerâmica sem recobrimento (grupo controle), cerâmica sem recobrimento submetida ao EAA, cerâmica recoberta com cimento resinoso, cerâmica recoberta com cimento resinoso submetida ao EAA. O teste de resistência à flexão biaxial foi realizado utilizando o dispositivo pistão-anel. Resistência à flexão biaxial (s fb , MPa), resistência característica (s 0 , MPa), e módulo de Weibull (m) foram calculados para as posições axiais z=0 (superfície da cerâmica) e z=−t2 (superfície do cimento). Os dados de s fb em z=0 e z=−t2 foram submetidos a análises estatísticas separadamente (a=0,05). A cerâmica não recoberta submetida ao EAA não teve diferença significante na s fb e s 0 comparada com o grupo controle. O recobrimento com cimento resinoso da cerâmica aumentou a s fb e s 0 em z=0. O EAA aumentou a s fb e s 0 para os espécimes de cerâmica recobertos com cimento resinoso em z=0 e também a s 0 em z=−t2. A confiabilidade em z=0 e z=−t2 não foi influenciada pelas variáveis testadas. Concluindo, o recobrimento com cimento resinoso melhorou a resistência mecânica da cerâmica feldspática. O procedimento de EAA não foi efetivo em envelhecer os espécimes de cerâmica feldspática recobertos ou não com cimento resinoso.

Effect of Surface Roughness on the Mechanical Properties of Ceramic-Polymer Blocks for CAD/CAM Dental Restoration / 대한치과재료학회지

The effect of surface roughness of ceramic-polymer CAD/CAM blocks on the mechanical properties was investigated in this study. Commercially available Polyglass (Vericom, Korea) and Enamic (Vita, Germany) were selected for this purpose. They were cut into either (4.0×2.1×17.0) mm and (3.0×4.0×17.0) mm, followed by grinding, and polished sequentially with 6 µm and 1 µm diamond paste. Flexural strength, fracture toughness, and Weibull analysis were determined according to ISO 6872 Dentistry-Ceramic materials. The elastic moduli were calculated from a stress-strain curves under flexural loading. The statistical significances of the mechanical properties between the products and surface roughness were analyzed with ANOVA and pared t-test at a significance level of 0.05. After grinding with 6 µm diamond paste after cutting by observing with an atomic force microscope, the arithmetic average roughness decreased to 47~49% and the maximum roughness decreased to 68~69%. When polishing with 1 µm diamond paste, The average roughness decreased to 13~22% and the maximum roughness decreased to 16~19%. When the flexural load was applied, stress increased linearly and fractured without plastic deformation both Polyglass and Enamic. As the surface roughness decreased, the mechanical properties were increased both Polyglass and Enamic. However, the mechanical properties of Polyglass increased up to P3, while Enamic showed almost maximal values at E2, after that there was no significant differences between E2 and E3. It could be due to the different microstructure between two blocks used in this experiment.

Analysis of Time-to-Onset and Onset-Pattern of Drug-Induced Blood Disorders with Monoclonal Antibody Agents / 医薬品情報学

Objectives: The aim of this study was to investigate both the time‐to‐onset and the onset‐pattern of drug‐induced blood disorders (DIBD) following the administration of monoclonal antibody agents through the use of the spontaneous adverse reaction reporting system of the Japanese Adverse Drug Event Report （JADER) database.Methods: Data in the JADER database from April 2004 to October 2017 were downloaded from the Pharmaceuticals and Medical Devices Agency website.　The DIBD dataset for monoclonal antibody agents was constructed based on the data for the drug information and adverse drug reactions.　The information for the adverse drug reactions was categorized in accordance with the preferred terms of the Medical Dictionary for Regulatory Activities and included thrombocytopenia, platelet count decreased, neutropenia, neutrophil count decreased, leukopenia, white blood cell count decreased, pancytopenia, anaemia, agranulocytosis, granulocyte count decreased, granulocytopenia, and bone marrow failure.　This dataset was then used to calculate the median onset times for the DIBD and the Weibull distribution parameters.Results: The median onset times of the DIBD for gemtuzumab ozogamicin, cetuximab, ramucirumab, trastuzumab, panitumumab, bevacizumab, infliximab, rituximab, trastuzumab, and ibritumomab tiuxetan (90Y) were 4, 10, 13, 14, 14, 14, 16, 16, 27, and 28 days, respectively.　The Weibull distributions for cetuximab, trastuzumab, bevacizumab, infliximab, and tocilizumab were estimated to fit the early failure type profile, while those for gemtuzumab ozogamicin, ramucirumab, rituximab, and ibritumomab tiuxetan (90Y) were estimated to fit the wear out failure type profile.　The Weibull distributions for panitumumab were estimated to fit the random failure type profile.Conclusions: The results of the present study clarified both the most likely time period and the onset‐pattern of DIBD that can occur in patients after the administration of monoclonal antibody agents.

Vacuum pulsed drying characteristics of Lycii Fructus based on Weibull distribution model / 中草药

Objective To mitigate Lycii Fructus surface crust and save drying time during drying process, vacuum pulsed drying technology was applied to dry Lycii Fructus so as to investigate moisture diffusion regulation and build the drying model. Methods The effect of different drying temperature (50, 55, 60, and 65 ℃), vacuum pressure holding time (5, 10, 20, and 30 min), and atmosphere pressure holding time (2, 4, and 8 min) on drying characteristics, moisture diffusion coefficients and drying activation energy was explored in vacuum pulsed drying process. Weibull model distribution was used to simulate and analyze Lycii Fructus drying curves. Results All the drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time had significant influence on drying time. When drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time was 60 ℃, 4 min, and 10 min, respectively, the minimum drying time was achieved to be 284 min. Weibull distribution model can be well described the vacuum pulsed drying process of Lycii Fructus. The scale parameter was related to drying time and decreased as drying temperature increased. The drying temperature, atmosphere pressure holding time, and vacuum pressure time holding time had little influence on the shape parameter. The shape parameter was associated with drying method. The moisture diffusion coefficient and activation energy were calculated to be 2.02 × 10-8-3.56 × 10-8 m2/s and 36.27 kJ/mol, respectively. Conclusion Weibull distribution model can well describe the moisture diffusion regulation of vacuum pulsed drying process of Lycii Fructus. The drying result had a great significance for predicting, controlling and optimizing drying process. On the other hand, the research could provide technical basis for industrial drying of Lycii Fructus by vacuum pulsed drying technology.

Preparation and performance evaluation of matrine-loaded thermosensitive in situ gel for rectum / 中草药

Objective: Optimize to obtain the in situ gel of matrine with thermosensitivity and rectal retention of bioadhesion rectum. Methods: Thermosensitive gel was prepared by cold method, and then using gelation temperature as an indicator, central combination design-response surface method (CCD-RSM) was used to optimize the dosage of P407, P188, and CMC-Na. Texture Analyzer was used to measure the gel strength and adhesion of prescription, the rectal retention was investigated by rectal administration, and the release rate was explored by modified paddle method. Results: The optimal prescription was matrine 2%, CMC-Na 1.0%, P188 1.3%, P407 16.5%, and benzalkonium bromide 0.02%. The prescription gel did not leak after rectal administration in rats, which can remain in the body for more than 6 h, in vitro release in line with Weibull model. Conclusion: The optimized matrine-loaded thermosensitive in situ gel could meet the requirement of rectal administration.