Measurement of Free Hemoglobin Percentage in Stored Packed Red Blood Cells Units by Colorimetric Method

Aims:To measure free hemoglobin percentage in stored packed red blood cells units by colorimetric method.Study Design:This is a descriptive, hospital based case study.Place and Duration of Study:Khartoum central blood bank during the period from June to September 2021.Methodology:A total of thirty-six packed red blood cells blood bags with Citrate-Phosphate-Dextrose-Adenine-one (CPDA-1) stored at 2-6°C for 35 days were withdrawn aseptically on days one; 14, and day 35. Free hemoglobin concentration was measured with Drabkin's method through digital photoelectric colorimeter in which the percentage of hemolysis was calculated, and PH values were measured by a PH meter (ADWA). Mean and standard deviation ofeach day were calculated by statistical package for social science (SPSS)computer program version 22.0.Results:The results showed statistically significant elevation in percentages of free plasma hemoglobin with prolongation of storage duration periods; day one compared with day 14 (P= 0.001), day one compared with day 35(P= 0.001) and day 14 compared with day 35 (P= 0.001). No significant correlation was observed between the degree of hemolysis in day 35 with PH values (P= 0.9).Conclusion:This study concluded that prolonged storage is associated with elevation of free plasma hemoglobin level indicative of progressive hemolysis.

Reversible regulation of enzyme-like activity of molybdenum disulfide quantum dots for colorimetric pharmaceutical analysis / 药物分析学报

Regulating the catalytic activity of nanozymes is significant for their applications in various fields.Here,we demonstrate a new strategy to achieve reversible regulation of the nanozyme's activity for sensing purpose.This strategy involves the use of zero-dimensional M0S2 quantum dots(MQDs)as the building blocks of nanozymes which display very weak peroxidase(POD)-like activity.Interestingly,such POD-like activity of the MQDs largely enhances in the presence of Fe3+while diminishes with the addition of captopril thereafter.Further investigations identify the mechanism of Fe3+-mediated aggregation-induced enhancement of the POD-like activity and the inhibitory effect of captopril on the enhance-ment,which is highly dependent on their concentrations.Based on this finding,a colorimetric method for the detection of captopril is developed.This sensing approach exhibits the merits of simplicity,rapidness,reliability,and low cost,which has been successfully applied in quality control of captopril in pharmaceutical products.Moreover,the present sensing platform allows smartphone read-out,which has promising applications in point-of-care testing devices for clinical diagnosis and drug analysis.

Potential effect of methanol leaf extracts from three Podocarpus species on experimental cryptosporidiosis

@#Cryptosporidiosis causes diarrhea in both immunocompetent and immunocompromised individuals, with acute manifestations occurring particularly in children and the elderly. Up till now, there is no curative therapy for cryptosporidiosis, so discovery of new classes of drugs are of great importance. This study aimed to examine the effect of methanol leaves extracts of the three Podocarpus species; P. macrophyllus (Thunb.), P. gracilior (Pilg.) and P. elongatus (Aiton) L’ Hér. ex Pers and their combination on Cryptosporidium parvum (C. parvum) in experimentally infected mice in comparison with the commercially used drug, Nitazoxanide. As well as spectrophotometric estimation of the total phenolic and flavonoid content of these extracts was done. Results revealed that treatment with these three Podocarpus extracts and their combination showed a significant reduction of the number of C. parvum oocyst shed in the stool of infected mice compared to infected control group and Nitazoxanideinfected treated group at P < 0.001. The combination of the three Podocarpus extracts was the most effective treatment showing the lowest number of oocysts shedding in comparison with other used extracts and Nitazoxanide. Histopathological inspection of sections from ilium and colon displayed signs of improvement after treatment with P. macrophyllus and P. gracilior extracts and more remarkable improvement when the three extracts were combined. It was concluded that the three Podocarpus species extracts used in this study had a promising anti-Cryptosporidium activity especially when they were combined.

Determinación de una nueva constante para la estimación del filtrado glomerular en pediatría / Determination of a new constant to estimate glomerular filtration rate in pediatrics

Introducción. En pediatría, el filtrado glomerular (FG) se puede calcular con el clearance (depuración) de creatinina medida corregida en ml/min/1,73 m2, o se puede estimar según la fórmula de Schwartz (FGe = talla/creatinina plasmática x k). La constante k depende del método de determinación de creatinina plasmática: k = 0,55 para el método colorimétrico de Jaffe, y k =0,413 para el método enzimático. Nuestro laboratorio utiliza el método colorimétrico cinético compensado (MCCC), se observan discordancias entre el FG estimado y el medido.Hipótesis: Los valores de k propuestos no se ajustan al MCCC de creatinina plasmática. Objetivo. Calcular el valor de k que permita estimar el FG mediante la cuantificación de la creatinina con el MCCC. Métodos. Diseño descriptivo correlacional. Se incluyeron pacientes de entre 3 y 18 años con FG normal o alterado atendidos en el Servicio de Nefrología Infantil entre julio de 2017 y enero de 2018 con control de esfínteres y firma del consentimiento. Se excluyeron pacientes desnutridos y con mielomeningocele. Las variables estudiadas fueron: creatinina plasmática y urinaria, talla y diuresis de 24 horas. Resultados. Se analizaron 184 pacientes, con una edad media de 10 años. La mediana del clearance de creatinina medido corregido fue de 123 ml/min/1,73 m2. La correlación lineal entre la talla y la creatinina plasmática y el clearance de creatinina medido corregido arrojó un valor de k de 0,499 (r = 0,974 y r2 = 0,949). La correlación lineal entre el FG estimado (k = 0,499) y el clearance de creatinina medido corregido mostró un coeficiente b = 0,999 (r = 0,951 y r2= 0,903). Conclusión. Según este estudio, la constante que permite estimar el filtrado glomerular al cuantificar la creatinina plasmática con el método colorimétrico cinético compensado es de 0,499.

Introduction. In pediatrics, glomerular filtration rate (GFR) may be estimated by measured corrected creatinine clearance (mcCrCl) (mL/min/1.73 m2) or the Schwartz formula (eGFR = height/plasma creatinine x k). The constant k depends on the plasma creatinine determination method: k = 0.55 for the Jaffe colorimetric method and k = 0.413 for the enzymatic method. Our laboratory uses the compensated kinetic colorimetric assay (CKC), and differences are observed between the estimated and measured GFR.Hypothesis: The proposed values of k do not adjust to the CKC method for plasma creatinine. Objective. To calculate a k value that allows to estimate GFR through creatinine measurement with CKC. Methods. Correlational, descriptive design. Patients aged 3-18 years seen at the Division of Pediatric Nephrology between July 2017 and January 2018 with normal or altered GFR, bladder and bowel control, and signed consent were included. Malnourished and myelomeningocele patients were excluded. Studied variables were plasma and urine creatinine, height, and 24-hour urine output. Results. A total of 184 patients were analyzed, their mean age was 10 years. Median mcCrCl was 123 mL/min/1.73 m2. The linear correlation between height and plasma creatinine and mcCrCl resulted in a k value of 0.499 (r = 0.974 and r2 = 0.949). The linear correlation between the estimated GFR (k = 0.499) and mcCrCl resulted in a 0.999 ß coefficient (r = 0.951 and r2 = 0.903). Conclusion. According to this study, the constant that allows to estimate GFR when measuring plasma creatinine with the CKC method is 0.499.

Preliminary Study on Commodity Grade Classification of Phyllanthi Fructus Based on Color Component Correlation / 中国实验方剂学杂志

Objective:To provide a scientific basis for the classification of Phyllanthi Fructus product grades. Method:A total of 30 batches of Phyllanthi Fructus currently available in the market were collected for quantification based on such appearance indexes as diameter， thickness， grain weight， and crust colour （<italic>L</italic>^*， <italic>a</italic>^*， and <italic>b</italic>^* values）. The contents of gallic acid， corilagin， chebulagic acid， and ellagic acid were measured by high performance liquid chromatography （HPLC）， followed by descriptive statistical analysis （DSA）， analysis of variance （ANOVA）， and principal component analysis （PCA） to determine the importance of each main index and explore the correlations between the appearance indexes and internal components. The classification standard of Phyllanthi Fructus product grades was formulated， and its scientificity was verified in hepatocelular carcinoma HepG2 cells. Result:The correlation analysis revealed that the crust colour <italic>L</italic>^*， <italic>a</italic>^*， and <italic>b</italic>^* values were significantly negatively correlated with corilagin， chebulagic acid， and ellagic acid （<italic>|r|</italic>>0.5， <italic>P</italic><0.01）， but irrelevant to gallic acid （<italic>|r|</italic><0.1）. Considering the variable coefficient of each index， PCA results， and the requirement of gallic acid as quality indicator for Phyllanthi Fructus in <italic>Chinese Pharmacopoeia</italic>， the crust colour <italic>L</italic>^*， <italic>a</italic>^*， and <italic>b</italic>^* values and gallic acid content were determined to be the classification indexes. The K-means cluster analysis confirmed that products with crust colour <italic>L</italic>^*<44， <italic>a</italic>^*<7， and <italic>b</italic>^*<10 and gallic acid content >1.6% could be classified into the first class， and those failing to meet the above requirements into the second class. The cell experiment demonstrated that the half-maximal inhibitory concentration （IC₅₀） of the first-class product against hepatocelular carcinoma HepG2 cells was lower than that of the second-class product. A colourimetric card was developed based on crust colour <italic>L</italic>^*， <italic>a</italic>^*， and <italic>b</italic>^* values to provide a visual tool for on-site evaluation of Phyllanthi Fructus products. Conclusion:This study has initially established the classification standard of Phyllanthi Fructus product grades， which contributes to guiding price negotiation of Phyllanthi Fructus products based on quality grade and thus ensuring high quality and high price.

Partial purification and characterization of antimicrobial peptide(s) from Mimosa pudica (Mimosaceae)

@#Plants have been a major source of natural products for sustaining human health. The use of the different parts of the plant as infusions, decoctions, extracts, and powders are being employed in the treatment of different diseases in humans, plants, and animals. One property of great significance in terms of therapeutic treatments, especially with the emergence of multi-drug resistant microbes, is the antimicrobial activity. A new promising source of antimicrobials that demonstrate novel mechanisms of therapeutic strategies is low molecular weight peptides. In this study, the antimicrobial activities of Mimosa pudica crude and partially purified peptide extracts against Gram-negative Enterobacter cloacae ATCC 23355 and Enterobacter aerogenes ATCC 13048, and Gram-positive Staphylococcus epidermidis ATCC 12228 using resazurin colorimetric assay and tricine SDS-PAGE bioautography were reported. M. pudica crude and partially purified extracts exhibited antimicrobial activity against all the bacteria tested. Specifically, the peptide that was partially purified from M. pudica with a molecular weight of 5.14 kDa inhibited the growth of Enterobacter cloacae.

Synthesis of Gold Nanoparticles using Bioreductants from the Aqueous Leaves Extract of Dillenia philippinensis Rolfe. (Katmon)

Background and Objectives@#Endemic plants are integral part of the ecosystem that provide innumerable benefits. Thus, emerging studies and applications using these endemic plants continue to increase globally. In this study, the preparation of gold nanoparticles (AuNPs) has been carried out by using the aqueous leaves extract of Dillenia philippinensis Rolfe. (Katmon) as the bioreductants. @*Methodology@#After the synthesis of AuNPs, the process was further subjected to optimization to assure the production of AuNPs with the best parameters. Synthesized and optimized AuNPs were characterized using FTIR, XRD, DLS, Zeta Potential, and TEM. @*Results@#Optimization results that provide the desired properties for AuNPs were a volume ratio of 1:2 (HAuCl₄: leaves extract), no significant difference (p>0.05) with the sequence of addition and reaction time, and acidic pH. The synthesized AuNPs' particles were found to contain hydroxyl and amine groups, had broad, amorphous, and spherical particles that have a mean diameter of 60.6nm, a PDI of 0.563, and a repulsion force of -13.720mV. The optimized and characterized AuNPs were then further used as a colorimetric sensing material, showing the potential applicability of AuNPs in the heavy metal analysis.@*Conclusion@#Gold nanoparticles were able to be synthesized with the use of bioreductants that are present in the aqueous leaves extract of Katmon. This concludes that endemic plants in the Philippines can be used for the synthesis of AuNPs and can be applied in the field of phytonanotechnology and other applied sciences.

A Schiff base of 2-((E)-(2-amino-5-methylphenylimino)methyl)- 5-(difluoromethoxy)phenol and its applications on fluorescent chemosensor for selection of Mg2+ ion, molecular docking, and anticancer activity

A novel Schiff base of 2-((E)-(2-amino-5-methylphenylimino)methyl)-5-(difluoromethoxy)phenol (R) wassynthesized and characterized by FTIR, 1H&13C-NMR, and mass spectrometry. The receptor turned yellow and thengreen in the presence of Mg2+ molecules, with the intervention of different metal ions. The selectivity and sensitivityof Mg2+ ion caused the maximum fluorescence emission intensity at 524 nm, with an excitation wavelength at 378nm. Further experiments confirmed that receptor R binds with Mg2+. Job’s plot conforms to a 1:1 stoichiometrycomplex formation. The strong fluorescence is owing to the photoinduced electron/energy transfer effect. The receptorwas recovered by an ethylenediaminetetraacetic acid titration and the emission intensity also returned to a valueequivalent to the unbound ligand. protein data bank: 4J96 was used for the molecular docking of receptor R. Thecytotoxicity effect treatment was carried out by increasing the concentration of HeLa cells to predict IC50 value. Thehighest occupied molecular orbital/lowest unoccupied molecular orbita energy gap calculated and compared betweenR results as 3.48 eV and R-Mg2+ alpha and the beta value calculated a low energy value at 2.27 eV.

Análise da presença de formol e avaliação do ph de alisantes capilares / Analysis of presence of formol and ph assessment in hair straighteners

O processo de alisamento capilar é uma prática comum realizada nos salões de beleza. O procedimento exige a utilização de substâncias com capacidade de rompimento das cadeias dissulfídricas da fibra capilar com posterior modelamento para o efeito desejado, sendo o formol um dos compostos mais utilizados para esta finalidade, porém indevidamente. De acordo com a legislação vigente, o formol só pode ser utilizado em produtos cosméticos com a função de conservante em uma concentração máxima de 0,2%. Devido a seu uso incorreto em produtos capilares o presente trabalho teve como objetivo realizar uma análise semi-quantitativa da presença de formol em amostras de alisantes capilares, bem como verificar o pH destes produtos. Foram obtidas 22 amostras de alisantes capilares doadas por salões de beleza da região de Umuarama - PR. A determinação da presença de formol foi realizada através da reação de Shiff e comparação com escala colorimétrica de concentrações padronizadas de formaldeído variando de 0,005% a 10%. A verificação do pH foi realizada através da preparação de soluções aquosas de 10% do alisante e posterior aferição em pHmetro digital. Das amostras analisadas, verificou-se 22,72% encontraram-se em conformidade, apresentando quantidade de formaldeído adequada com a legislação (até 0,2%) ou ausência do composto, enquanto que 77,28% apresentaram valores acima do permitido. Já o pH adequado foi constatado em apenas 13,64% amostras. O uso incorreto ou exagerado do formol pode acarretar danos à saúde, como cefaléia, dispnéia, queimadura, edema pulmonar e até câncer. Uma maior fiscalização deve ser realizada nos estabelecimentos que realizam procedimentos de alisamento capilar, bem como nas indústrias produtoras e ainda em importadoras, para uma melhor garantia do cumprimento da legislação tanto para a preservação da saúde dos profissionais quando dos usuários.

The hair-straightening process is a common practice in most beauty salons. The procedure requires the use of substances capable of disrupting the disulfide chains of the hair fiber with subsequent modeling for the desired effect, with formaldehyde being one of the most commonly but improperly used compounds for this purpose. According to the current legislation, formaldehyde can only be used in cosmetic products as a preservative function in a maximum concentration of 0.2%. Due to its incorrect use in capillary products, this work has the purpose of developing a semi-quantitative analysis of the presence of formaldehyde in samples of hair straighteners, as well as verifying the pH of those products. Twenty-two samples of hair straighteners were donated by beauty salons from the region of Umuarama-PR. The determination of the presence of formaldehyde was performed using the Shiff reaction and compared using the colorimetric scale for standard formaldehyde concentrations varying from 0.005% to 10%. The pH verification was carried out by the preparation of 10% aqueous solutions of the straightener and subsequent measurement in a digital pH meter. From the analyzed samples, 22.72% were found to be in compliance, presenting the amount of formaldehyde within the legislation (up to 0.2%) or absence of the compound, while 77.28% presenting values above the legal limitations. Additionally, adequate pH was verified in only 13.64% of the samples. Incorrect or exaggerated use of formaldehyde can lead to health issues, such as headache, dyspnea, burns, pulmonary edema and even cancer. Greater surveillance should be carried out in establishments that perform hair straightening procedures as well as in the producing and importing industries in order to guarantee better compliance with the legislation both for the preservation of the health of professionals and users alike.

Comparación y evaluación de métodos cuantitativos para determinar la susceptibilidad antimicrobiana de cepas del complejo Mycobacterium abscessus / Comparison and Evaluation of Quantitative Methods for Determining Antimicrobial Susceptibility of Complex Mycobacterium Abscessus Strains / Comparação e avaliação de métodos quantitativos para determinar a susceptibilidade antimicrobiana de cepas do complexo Mycobacterium abscessos

Resumen Introducción: el complejo Mycobacterium abscessus incluye especies patógenas emergentes multirresistentes, lo cual limita las opciones terapéuticas para tratar las infecciones causadas por dichos microorganismos. En este estudio se compararon las concentraciones inhibitorias mínimas (CIM) obtenidas mediante dos métodos cuantitativos, se establecieron los puntos de corte empleados en el micrométodo colorimétrico (MMC) y se evaluó la susceptibilidad antimicrobiana. Materiales y métodos: la CIM de nueve antibióticos fue determinada mediante el MMC y la microdilución en caldo (MDC) para 19 cepas del complejo M. abscessus. El test F de Snedecor se utilizó para establecer la diferencia significativa de las CIM entre los dos métodos y se determinaron los puntos de corte mediante la técnica de distribución de la probabilidad para el MMC. Resultados: se encontró una correlación de los resultados de la CIM del 50% entre MMC y MDC para los antibióticos ensayados. Probablemente esta discrepancia en los resultados se deba a diferencias en algunos parámetros técnicos de cada procedimiento. Todas las cepas fueron sensibles a la amikacina y resistentes a meropenem y ampicilina-sulbactam. Independientemente de la especie del complejo M. abscessus, las fluoroquinolonas mostraron una baja actividad inhibitoria (0-25%) sobre los aislados clínicos, resultados que son similares a los reportados por otros autores. Conclusión: Los patrones de multirresistencia observados en las cepas analizadas sugieren la necesidad de utilizar las pruebas de susceptibilidad como herramientas que permitan orientar y optimizar las conductas terapéuticas en infecciones producidas por M. abscessus.

Abstract Introduction: The Mycobacterium abscessus complex includes multidrug resistant emerging pathogens, which limit therapeutic options for treating infections caused by these microorganisms. In this study, the minimum inhibitory concentrations (MICS) obtained by 2 quantitative methods were compared, the cut-off points used in the colorimetric micromethod (CMM) were established and the antimicrobial susceptibility was evaluated. Materials and Methods: The MIC for nine antibiotics was determined by CMM and broth microdilution (BMD) for 19 strains of M. abscessus complex. The Snedecor F test was used to establish the significant difference in the CIM between the methods, cutoff points were determined by the probability distribution method for the CMM. Discussion: A correlation of 50% between CMM and BMD for antibiotics tested was found. Probably, this discrepancy in the results is due to differences in some technical parameters of each procedure. All strains were susceptible to amikacin and were resistant to meropenem and ampicillin-sulbactam. Independently of the species of M. abscessus complex, fluoroquinolones showed a low inhibitory activity (0-25%) on clinical isolates, results that are similar to those reported by other authors. Conclussion: The Multidrug resistance patterns observed in the strains tested suggest the need for susceptibility testing as tools to guide and optimize the therapeutic behavior in infections caused by M. abscessus.

Resumo Introdução: o complexo Mycobacterium abscessus inclui espécies patógenas emergentes multirresistentes, o qual limita as opções terapêuticas para tratar as infeções causadas por estes microrganismos. Neste estudo compararam-se as concentrações inibitórias mínimas (CIMS) obtidas mediante 2 métodos quantitativos, se estabeleceram os pontos de corte empregados no micrométodo colorimétrico (MMC) e se avaliou a susceptibilidade antimicrobiana. Materiais e métodos: a CIM de 9 antibióticos foi determinada mediante o MMC e microdiluição em caldo (MDC) para 19 cepas do complexo M. abscessus. O teste F de Snedecor utilizou-se para estabelecer a diferença significativa das CIMS entre os dois métodos e determinaram-se os pontos de corte mediante a técnica de distribuição da probabilidade para o MMC. Resultados: se encontrou uma correlação dos resultados da CIM do 50% entre MMC e MDC para os antibióticos testados. Provavelmente, esta discrepância nos resultados se deve a diferenças em alguns parâmetros técnicos de cada procedimento. Todas as cepas foram sensíveis à amikacina e resistentes a meropenem e ampicilina-sulbactam. Independentemente da espécie do complexo M. abscessos, as fluoroquinolonas mostraram uma baixa atividade inibitória (0-25%) sobre os isolados clínicos, resultados que são similares aos reportados por outros autores. Conclussão: Os patrões de multirresistência observados nas cepas analisadas, sugerem a necessidade de utilizar as provas de susceptibilidade como ferramentas que permitam orientar e otimizar as condutas terapêuticas em infeções produzidas por M. abscessus.

Quantitative determination method and application of pharmaceutical adjuvant tween 80 / 中国中药杂志

Based on the fact that chromogenic reaction of blue complex, a reaction product which can be dissolved in organic solvents, can be realized by polyethoxy and ammonium thiocyanate in tween 80, a rapid and accurate way for the determination for tween 80 in pharmaceutical adjuvant was established in this study, providing reliable technical means for quality control of traditional Chinese medicine injections. Based on the study of reaction kinetics, chromogenic reaction temperature and time, as well as extraction of organic solvents and other key conditions were optimized, and Kumu injection was used as the test material for method validation and applicability investigation. It was finally determined that 3 mL ammonium thiocyanate solution was added in the sample solution, and the reaction was carried out in a boiling water bath for 2 h. After cooling to room temperature, 5 mL of dichloromethane was added to extract the chromogenic product. The absorbance value was measured at the wavelength of 623 nm to calculate the tween 80 content in the sample. Under optimized conditions, tween 80 solution showed a good linear relationship with the absorbance in the range from 0.8 mg to 3.0 mg. The linear regression equation was ＝0.258-0.047. The correlation coefficient was 0.999 6. Under the experimental conditions, the average recovery was 99.66%, and the precision RSD was less than 2.0%. The results showed that this method can quickly and accurately determine the content of tween 80 in Kumu injection, and it could be applicable to the quality control of traditional Chinese medicine injections.

Correlation of Caries Experience and Activity between Mothers and Their Children Using a Colorimetric Test / 대한소아치과학회지

The purpose of this study was to compare the validity of Cariview®, a new colorimetric caries activity test, with CRT® bacteria, a conventional bacterial culture method. In addition, this study assesses the correlation between the dental caries experience and activity between mothers and their children.34 pairs of mothers and their children under the age of 6 years participated in this study with informed consent. After filling out a questionnaire and oral examination, the two caries activity tests above were performed on each subject.In the results, Cariview® scores were statistically significant with children's caries experience (r = 0.598, p <0.01) and showed higher correlation than CRT® bacteria scores. Cariview® scores showed statistically significant correlation with the number of decayed teeth in both mothers and children (p <0.05). In both Cariview® and CRT® bacteria tests, there was no statistically significant correlation between caries experience and caries activity (p > 0.05).Cariview® colorimetric test will be clinically useful for predicting future caries risk and establishing a preventative strategy in pediatric dentistry.

The feasibility study of gold nanoparticle composites (ssDNA-AuNPs) for the colorimetric detection of gamma radiation dose / 中华放射医学与防护杂志

Objective To establish a simple and convenient method and study the feasibility of using gold nanoparticle composites (ssDNA-AuNPs) for colorimetric detection of gamma radiation.Methods The composites ssDNA-AuNPs were prepared by applying the ssDNA to the surface of AuNPs,and then were irradiated with gamma ray with absorbed doses of 0,5,10,20,and 30 Gy,respectively.Subsequently the color change in the solutions were observed simultaneously with absorption spectra being measured.The linear relationship between the ratio of A625/A521 in the absorption spectrum and the absorbed dose was established.Results With the increase of radiation dose,the color of the solutions changed from wine-red to blue-violet gradually,the ratio of A625/A521 in absorption spectra had excellent liner response for absorbed dose ranging from 0 to 30 Gy,and the linear equation was A625/A521 =0.020 6 + 0.303 6 E(R2 =0.991 5).Conclusions The ssDNA-AuNPs synthesized in this experiment can be successfully used for colorimetric detection of gamma absorbed dose,and a simple and convenient method for detection of gamma radiation has been newly established.

Synthesis and Application of Gold Nanoclusters for Detection of Heavy Metal Mercury Ions / 分析化学

A colorimetric method was developed for detection of mercury based on the inhibition of oxidation of peroxidase substrates. The as-prepared gold nanoclusters ( Au NCs), which has been stabilized and reduced by Glutathione (GSH), can effectively catalyze the H2 O2-TMB to generate a blue color signal. It is interestingly that Hg2+ can inhibit the oxidation of peroxidase substrates, thus causing a color diminished. Taking advantage of the inhibitive effect of Hg2+, a novel Hg2+ sensor has been developed. In this system, sensing conditions, including pH of the buffer solution, substrate concentration and time, were optimized. Under the optimal conditions, the probe showed a linear range of 10 - 300 nmol/ L ( R2 = 0. 997) with a detection limit of 6. 26 nmol/ L. In addition, this sensor exhibited good selectivity and sensitivity for Hg2+against other common environmental mental ions, providing a new method for water analysis.

Pb2+-Induced Allosteric PS2.M as A Label-Free Colorimetric Sensor for Detection of Cumulative Radon Radiation / 分析化学

A new sensitive method for detection of cumulative radon radiation based on the lead was established. PS2.M which stabilized by K+with hemin as a co-factor exhibits superior peroxidase-like activity, and can effectively catalyze the H2O2-mediated oxidation of TMB. In the presence of Pb2+, K+-stabilized PS2.M DNAzymes are induced to undergo a conformational change,because Pb2+has a higher efficiency with regard to stabilizing G-quadruplexes than K+, accompanied by a decrease of catalytic activity and a sharp decrease of readout signal. In the work, a novel"turn-off"model of colorimetry-Pb2+biosensor based on superior peroxidase-like activity of G-quadruplex for Pb2+analysis was developed. The fading degree of reaction system (△A value) was linearly related to Pb2+concentration in the range of 5. 0×10-9-1. 8× 10-7mol/L. The linear regression equation was △A=0.36+0.13C (10-8mol/L), with R=0.9987. The detection limits of lead and radon were 3.76 nmol/L(S/N=3) and 1.96×103Bq·h/m3(S/N=3), respectively. The method exhibited good selectivity, high sensitivity and convenient operation, and could avoid the radioactive hazard in determination of the radon in environment.

Comparação entre três métodos analíticos para determinação de soro em leite cru refrigerado / Comparison of three analytical methods to determine serum in refrigerated raw milk

O objetivo deste experimento foi comparar três métodos analíticos para determinação de soro em leite cru refrigerado: cromatografia líquida de alta eficiência, ninidrina ácida e colorimétrico adaptado. Foram coletadas 100 amostras de leite cru refrigerado de tanques de expansão. Estas, quando submetidas à análise pelo método da ninidrina ácida, apresentaram 10 (14,7%) amostras negativas e 58 (85,3%) positivas. O teor médio de ácido siálico encontrado na técnica da ninidrina foi de 5,58(g/mL, com valor mais frequente de 2,70(g/mL. Das 68 amostras negativas pela cromatografia líquida de alta eficiência, duas foram positivas (2,94%) e 66 (97,06%) negativas, quando analisadas pelo método colorimétrico. A frequência relativa de amostras positivas foi de 32%, com a CLAE apresentando a maior média de soro (14,37%), seguida do método colorimétrico (5,28%) e o da ninidrina ácida (3,12%). A técnica de cromatografia líquida de alta eficiência diferiu dos métodos de ninidrina ácida e colorimétrico, enquanto os métodos da ninidrina e colorimétrico não diferiram entre si, podendo ambos serem utilizados como metodologias de triagem. Entre as três técnicas, a cromatografia líquida de alta eficiência foi a metodologia mais sensível na detecção e quantificação do soro em leite cru refrigerado.(AU)

The objective of this study was to compare three analytical methods to determine serum in refrigerated raw milk. High-performance liquid chromatography (HPLC), acidic and colorimetric ninhydrin methods were applied. A collection of 100 samples of raw milk from cooled expansion tanks took place. The results showed that 10 samples (14.7%) were negative and 58 (85.3%) were positive for the acidic ninhydrin method. The mean sialic acid content found in the ninhydrin technique was 5.58µg/mL, with a more frequent value of 2.70µg/mL. From all 68 HPLC negative samples, two were positive (2.94%) and 66 (97.06%) negative to the colorimetric method. The relative frequency of positive samples was 32%, HPLC had the highest mean serum levels (14.37%), followed by the colorimetric method (5.28%) and acid ninhydrin (3.12%). The high-performance liquid chromatography method was different from the acid and colorimetric ninhydrin methods. The ninhydrin and colorimetric methods were not different from each other, both of which could be used as screening methodologies. Among the three techniques, HPLC was the most sensitive methodology for the detection and quantification of serum in refrigerated raw milk.(AU)

Effect of seasonality on the quality of bovine oocytes selected by the brilliant cresyl blue method / Efecto de la estacionalidad en la calidad de los ovocitos seleccionados por el método de azul cresil brillante / Efeito da sazonalidade na qualidade dos ovócitos bovinos selecionados pelo método azul cresil brilhante

Abstract Background: The brilliant cresyl blue (BCB) staining is a non-invasive test to select the best-suited oocytes for embryonic development. This makes it a useful tool to select best-quality oocytes at the times of the year when there is forage restriction. Objective: To evaluate the effect of seasonality on the nuclear maturation and quality of oocytes selected by the BCB test. Methods: The cumulus-oophorus complexes (COCs) were obtained in summer and winter of 2010 and 2011. Selected COCs were maintained for 90 min at 38.5 °C in a CO2 incubator, in TCM 199 medium containing 10% fetal bovine serum and antibiotics, and supplemented with 26 µM brilliant cresyl blue. Afterwards, they were divided according to the ooplasm staining (BCB+ -blue; BCB− -unstained). Subsequently, COCs were matured for 22 h. Nuclear maturation was evaluated at 22 h of culture. Results: The proportion of BCB− oocytes was higher in the winter of 2010, but there was no increase in this group in the winter of 2011. The percentage of oocytes that reached metaphase II was higher in control and BCB+ groups in relation to oocytes from BCB− group. Conclusion: The season of the year influences the percentage of oocytes best suited for embryonic production in situations in which oocyte donors receive pasture-based feeding, since the method was effective in determining the effect of seasonality on the competence of bovine oocytes to reach nuclear maturation.

Resumen Antecedentes: La tinción con azul cresil brillante (BCB) es un método no invasivo para seleccionar ovocitos aptos para el desarrollo embrionario. Por tanto, es una herramienta útil para selecionar los ovocitos de mejor calidad en temporadas de restricción de forraje. Objetivo: Evaluar el efecto de la estacionalidad sobre la maduración nuclear y calidad de los ovocitos seleccionados por el test BCB. Métodos: Los complejos cumulus-oophorus (CCOs) fueron obtenidos durante el verano y el invierno de 2010 y 2011. Los CCOs seleccionados se mantuvieron durante 90 min a 38,5 oC en una incubadora de CO2 en un medio TCM 199 con 10% de suero fetal bovino y antibióticos, suplementado con 26 µM de azul cresil brillante. Luego se separaron según el color del citoplasma (BCB+ -azul y BCB− -incoloro). Posteriormente, los CCOs se maduraron durante 22 h. La evaluación de la maduración nuclear se realizó a las 22 h de cultivo. Resultados: La proporción de ovocitos BCB− fue mayor en el invierno de 2010, pero no hubo un aumento de ese grupo en el invierno de 2011. El porcentaje de ovocitos que alcanzaron la etapa de metafase II fue mayor en el grupo control y BCB+ con respecto al grupo BCB−. Conclusión: La estación del año influye en el porcentaje de ovocitos más aptos para la producción de embriones en situaciones donde las donadoras de ovocitos reciben alimentación a base de pastos, ya que este método fue eficaz para determinar el efecto de la estacionalidad en la competencia de ovocitos bovinos en alcanzar la maduración nuclear.

Resumo Antecedentes: O método do azul cresil brilhante (BCB) não é invasivo e seleciona ovócitos mais aptos ao desenvolvimento embrionário. Portanto é ferramenta útil para selecionar ovócitos de melhor qualidade em épocas do ano que ocorre restrição de pastagem. Objetivo: Avaliar o efeito da sazonalidade sobre a maturação nuclear e a qualidade dos ovócitos selecionados pelo teste BCB. Métodos: Os complexos cumulus oophorus (CCOs) foram obtidos no verão e inverno de 2010 e 2011. Os CCOs selecionados foram mantidos por 90 min, a 38,5 °C, em incubadora de CO2, em meio TCM 199 contendo 10% de soro fetal bovino e antibióticos, e suplementado com 26 µM de azul cresil brilhante. Em seguida, estes foram divididos de acordo com a coloração do citoplasma (BCB+ -azuis e BCB− -incolores). Então os CCOs foram maturados durante 22 h. A avaliação da maturação nuclear foi realizada às 22 h de cultivo. Resultados: A proporção dos ovócitos BCB− foi maior no inverno de 2010, mas não houve aumento desse grupo no inverno de 2011. O percentual de ovócitos que atingiu o estágio de metáfase II foi maior no controle e no grupo BCB+ em relação ao grupo BCB−. Conclusão: A estação do ano influencia o percentual de ovócitos mais aptos a produção de embriões, em situações onde as doadoras de ovócitos recebem alimentação baseada em pastagens, já que o método se mostrou efetivo para determinação do efeito da sazonalidade sobre a competência de ovócitos bovinos em atingirem a maturação nuclear.

Progress on Optical Probes for Hydrogen Sulfate Anion Sensing / 分析化学

The hydrogen sulfate plays an important role in biological and environmental areas and can contaminate the environment, which will cause harm to human body.Thus it is of primary importance to detect hydrogen sulfate with high selectivity and sensitivity.Among these methods for detection of hydrogen sulfate, the optical chemosensor based on molecular recognition is desirable with unique advantage.Anions optical sensing systems are predominantly attractive due to their simplicity, high degree of specificity, low detection limits, easy on-line analysis and especial colorimetric recognition and in situ detection.Herein, the progress during the last decades of optical chemosensors and probes for hydrogen sulfate based on the recognizing mechanism is summarized.The further research orientations are also prospected.

Colorimetric Detection of Copper Ions Based on Surface Modification of Silver/Platinum Cluster Nanoenzyme / 分析化学

A sensitive colorimetric method for the detection of copper ions (Cu2+) was developed based on the surface modification of silver/platinum nanoclusters (Ag/Pt NCs) and regulation of peroxidase-like activity. It was found that 3-mercaptopropionic acid (MPA) could inhibit the catalytic ability of Ag/Pt NCs; however, it lost the inhibition toward catalytic ability of Ag/Pt NCs after oxidized by oxygen through the catalysis of Cu2+. On the basis of this, a colorimetric method was developed for the detection of Cu2+ through measuring the colorimetric signal variation of the TMB-H2O2 reaction. This method exhibited high sensitivity and selectivity toward Cu2+ over a panel of other metal ions. The linear range was 10-100 nmol/L and the detection limit was 5.0 nmol/L (3σ). The above method was also applied to detect real water samples and spiked samples, and the results demonstrated that this method was simple with low cost.

Study on Determination Method of Total Flavonoids in Gansu Astragali Radix and ;Hedysarum Polybotrys / 中国中医药信息杂志

Objective To study the determination method of total flavonoids in Gansu Astragali Radix and Hedysarum Polybotrys. Methods Calycosin glycosides etc. was selected as reference substances, comparison on the difference of absorption curves was done by ultraviolet spectroscopy and colorimetric method (NaNO2-Al(NO3)3-NaOH, AlCl3, Mg(Ac)2, NaOH, phosphomolybdic acid, HCl-Mg power). Results With colorimetric method, the maximum absorption wavelength of referrence and the test was inconsistent. The absorption peak shape was also different. With UV method, Calycosin glycosides in band Ⅱ (260 nm) showed a shoulder absorption. Astragali Radix and Hedysarum Polybotrys also showed characteristic shoulder absorptions in band Ⅱ with absorption wavelength at 263 nm and 265 nm. So the sample absorption wavelength is basically the same as that of the control sample. Conclusion Colorimetries usually used for determination of total flavonoids are not suitable for the comparison determination of Gansu Astragali Radix and Hedysarum Polybotrys. It is suitable for determining the contents of total flavonoids in samples by UV spectrophotometry at the band Ⅱ, which is the characteristic absorption band of isoflavone compound.