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Aim: The aim of this study was to verify the color variation between different composite resins and the Vita Classical Shade Guide. Methods: Two-millimeter thickness samples were made (n = 6) from eight commercial brands of composite resin (shade A2): Charisma (Kulzer), Forma (Ultradent), Harmonize (Kerr), Luna (SDI), Opallis (FGM), Oppus Bulk Fill (FGM), Vittra (FGM) and Filtek Z250 XT (3M ESPE). Specimens were stored in distilled water for 7 days and then polished. Color measurements of samples and A2 shade of the Vita Classical Shade Guide were performed using the Vita Easy Shade Advance 4.0 spectrophotometer on a black background. Color variations were calculated using the CIEDE2000 formula, considering values ≥0.81 being noticeable by the human eye and ≥1.77 being clinically unacceptable. Results were statistically analyzed with a 5% significance level. Results: Color variation (ΔE) of composite (E1 ) compared to the Vita Classical Shade Guide (E0 ) was greater than clinically acceptable for all the materials evaluated in this study. Forma (ΔE=2.08 ± sd=0.47) and Filtek Z250 XT (2.50 ± 0.20) had the smallest amount of color variation values found in the results. Harmonize (3.32 ± 0.63) presented values similar to Filtek Z250 XT, but it was worse than Forma. Vittra (3.51 ± 0.28), Charisma (3.80 ± 0.20), Opallis (4.24 ± 0.30) and Luna (5.67 ± 0.20) did not differ among each other and presented higher color variation than Forma, Filtek Z350XT and Harmonize. Oppus Bulk Fill (13.94 ± 1.12) was the composite with the greatest color variation. Conclusions: The findings in this study show that attention should be taken when using the Vita Color Shade Guide for composite shade selection
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Spectrophotometry , Distilled Water , Color , Composite ResinsABSTRACT
ABSTRACT Purpose: To determine the absorbance coefficient of the thin porcine cornea to ultraviolet-A radiation (365 nm) submitted for crosslinking. Methods: This in vitro, benchtop experiment using cadaver tissue study analyzed 12 porcine corneal lamellas, which were obtained using a microkeratome after mechanical de-epithelization and separated into three thickness groups: 180, 300, and 360 μm. The corneal thickness values were measured by anterior-segment optical coherence tomography. All lamellas had ultraviolet-A (365 nm) absorbance measured with a 96-well plate spectrophotometer using an ultraviolet transparent microplate before riboflavin instillation and preand post-crosslinking according to the Dresden protocol. Results: The ultraviolet absorbance profiles of the 180, 300, and 360 μm groups were obtained as α-coefficients of 12.85, 76.55, and 120.27, respectively. A theoretical formula was calculated though a statistical analysis that demonstrated the correlation between stromal lamellar thickness and ultraviolet absorbance. Conclusions: Corneal thickness and ultraviolet-A spectral absorbance of corneal lamellas showed linear correlation. These findings can potentially contribute to the optimization of ultraviolet-A application during crosslinking, making the treatment of corneas with thickness <400 μm safe and personalized energy delivery for each corneal thickness.
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Background-Oxidative stress in biological systems is a complex process that is characterized by an inequity between the production of free radicals (FR) and the ability of the body to eliminate these reactive species through the use of endogenous and exogenous antioxidants. The pathogenesis of oral cancer has been linked to alterations in the antioxidant defense mechanism. Materials & Methods- Saliva from twenty patients with OSCC, forty patients with OPMDs and twenty healthy subjects in the age group of thirty five to seventy five years was analyzed for levels of nitric oxide, vitamin C, total sialic acid and GSH using spectrophotometry. Results - The levels of salivary vitamin C and glutathione were significantly reduced and those of nitric oxide and sialic acid were raised in patients having OPMD's and oral squamous cell carcinoma. The co- relation between the AOI and calculated ratios indicated that antioxidant potential of the saliva was decreased and was statistically related to (p <0.001) development of OPMD, which further may progress to oral cancer, notably OSCC. Conclusion- The current study demonstrated that the estimation of vitamin C, nitric oxide, sialic acid and GSH in saliva could be used as an early potential diagnostic biomarker in the screening of oral cancer. The antioxidant-oxidant indices (AOI's) can be used as a reliable tool for predicting the oral microenvironment and its predicted change towards development of oral cancer. This optimized developed protocol was also found to be simple and cost effective.
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Medicinal plants have been used in all cultures as a source of medicine since ages. When parts of plants such as rhizomes, leaves or barks and other natural materials are used as drugs to treat illnesses, they are called crude drugs and the study of crude drugs is called pharmacognosy. Proximate analysis in plants gives valuable information and help to assess the quality of a crude drug. Beneficial effects of crude drugs are believed to be attributed to plant phytochemicals. Hedychium coronarium J. Koenig, a medicinal and aromatic plant of high value is an endangered and red-listed plant. The rhizome of this plant is used for the treatment of various diseases. Crude extracts prepared from the rhizomes show antibacterial and antifungal properties. Essential oils obtained from Hedychium coronarium are found to be rich in terpenes and used for bactericidal, fungicidal, medicinal and cosmetic applications. The present study assesses the quality of crude drugs prepared from this highly medicinal plant. Proximate analysis and phytochemical screening of rhizomes of Hedychium coronarium, which is frequently consumed as food and as medicine were carried out. Ash content was found to be low) when compared to the moisture content. The water extractive value was more than alcohol extractive. Preliminary tests carried out on phytochemicals revealed the presence of terpenoids and oils. High Resolution Liquid Chromatography Mass Spectrophotometry was carried to ascertain the different components of essential oils and revealed the presence of eucalyptol (1,8-cineole), caryophyllene oxide, camphor, linoleic acid, ricinin, phloroglucinol, 6-gingerol, carvone and arjungenin.
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Objective:To investigate the effects of different light sources on the stability of cinepazide maleate in sodium chloride solution, providing a theoretical basis for standardizing operation for avoiding light in clinical medication.Methods:First, a standard curve was created and methodological studies were conducted. Then, intravenous drip solutions were prepared using clinically prescribed methods. Then, the absorbance of the solution of cinepazide maleate injection under outdoor light, light emitting diode (LED) light, indoor light, artificial sunlight with a color temperature of 6 500 K (D65), and under a shading condition for 1, 2, 3, and 7 hours were brought into the standard curve to obtain the concentrations, and the change of the concentrations was studied.Results:There was no light decomposition phenomenon of cinepazide maleate injection in the shading group (control group) within 7 hours. In the other four experimental groups, there was no obvious light decomposition phenomenon of cinepazide maleate injection in the LED light group. Compared with the shading group, cinepazide maleate injection in the indoor, outdoor, and D65 groups began to exhibit a light decomposition phenomenon at 1 hour ( F = 44 840.44, P < 0.001). At 2 hours, cinepazide maleate content in the outdoor and D65 groups began to decrease significantly compared with the shading group ( F = 15 459.12, P < 0.001). At 7 hours, cinepazide maleate exhibited significantly greater light decomposition in the outdoor group [(29.84 ± 0.43) L·mol -1·cm -1] and D65 group [(21.01 ± 0.51) L·mol -1·cm -1] than the shading group [(101.65 ± 1.5) L·mol -1·cm -1] ( F = 63 106.32, P < 0.001). There was no significant difference in cinepazide maleate content between LED and shading groups ( P > 0.05). Conclusion:Cinepazide maleate injection is stable under the common LED light source and therefore it is not necessary to take lightproof operation. Cinepazide maleate injection is unstable under indoor, outdoor, and D65 light sources, and it is necessary to take lightproof operation.
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Objective:To investigate the compatibility stability of cinepazide maleate injection and dopamine hydrochloride injection and explore the basis for the combined application of cinnamazide maleate injection and dopamine hydrochloride injection.Methods:A method for determining cinnamazide maleate injection and dopamine hydrochloride injection was established using an ultraviolet-visible spectrophotometer and verified from March 1, 2021 to May 20, 2021. The color and pH value of the solution prepared using the two drugs were determined within 5 hours at room temperature. The content change of the prepared solution was determined using an ultraviolet-visible spectrophotometer.Results:The linear range of the mass concentration of cinnamazide maleate was 4.03 - 32.24 mg/L and the linear range of dopamine hydrochloride was 20 -120 mg/L. At 25 ℃, the color of the prepared solution did not change within 5 hours and the pH value was in the range of 4.43 ± 0.06, indicating that the pH of the prepared solution did not change markedly. The concentrations of cinnamazide maleate and dopamine hydrochloride were (98.23 ± 1.09)% and (99.96 ± 0.41)% respectively, indicating good stability.Conclusion:The prepared solution using cinepazide maleate injection and dopamine hydrochloride injection can be used within 5 hours at 25 ℃.
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Objective:To establish a method for automatic determination of iodine level in salt by arsenic-cerium catalytic spectrophotometry using an iodine element detector (hereinafter referred to as this method), and to provide reference for in-depth study of salt iodine detection technology.Methods:This method was used to determine the iodine level in salt, and the linear range, detection limit, precision, and accuracy (determination of salt iodine standard substance GBW10006y and GBW10007y, and addition recovery experiment) of this method were determined. The iodine level of 35 salt samples was determined by this method and redox titration method recommended by the national standard, and the results were compared.Results:This method had a good linear relationship within the range of 50 - 600 μg/L standard curve, the absolute value of the correlation coefficients was > 0.999 0, and the detection limit was 5.0 mg/kg. The relative standard deviation of iodine concentration in salt samples with low, medium and high iodine concentrations were all < 6.0%. The determination results of salt iodine standard substance GBW10006y and GBW10007y were within the given value ranges; three iodine concentrations (6.0, 10.0 and 30.0 mg/kg) were added to the salt samples, with an average recovery rate of 96.7% to 105.0%, and a total average recovery rate of 100.9%. The method comparison experiment showed that there was no statistically significant difference between the salt iodine determination results of this method and the redox titration method ( t = - 1.54, P = 0.132). Conclusion:This method has the advantages of high accuracy, good precision and wide linear range in determining salt iodine, and is suitable for the detection of large quantities of samples in salt iodine monitoring.
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Objective To establish an infrared spectrophotometric method for determination of mineral oil mist in workplace air. Methods The mineral oil mist in workplace air was sampled with glass fiber filter membrane and eluted with carbon tetrachloride. Petroleum-like standard solution of carbon tetrachloride was used as the calibration standard, and quantitative analysis was performed using infrared spectrophotometric oil analyzer. Results The sampling efficiency of the glass fiber filter membrane ranged from 94.8% to 99.2%, and the extraction efficiency ranged from 95.6% to 104.2%. The linear range of mineral oil mist was 1.00-120.00 mg/L, with a correlation coefficient of 0.999 4. The detection limit was 0.52 mg/L, and the quantification limit was 1.74 mg/L. The average recovery rate ranged from 98.8% to 104.1%. The within- and between- run relative standard deviations were 2.2%-6.4% and 2.3%-5.2%, respectively. The samples were stable at room temperature for seven days. This method could be used for air sampling of mineral oil mist in workplaces where mineral oil is used. Conclusion The method is sensitive, accurate, and efficient, which is suitable for determining the concentration of mineral oil mist in workplace air.
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@#Objective To develop and verify a sulfosalicylic acid spectrophotometric method for the determination of trace iron ions in diphtheria toxin medium,and apply it preliminarily.Methods The maximum absorbance of the complex of iron and sulfosalicylic acid was scanned by full spectrum;A method for the determination of iron ion in culture medium was developed by linear regression between the absorbance of the complex and the content of iron ion,and the stability,accuracy and precision of the method were verified.The effects of Ca~(2+),Mg~(2+),K~+,Na~+ and reactants on the method were investigated.Spectrophotometric method with sulfosalicylic acid was used to determine trace iron in the self-made and commercial medium for diphtheria toxin production.Sulfosalicylic acid spectrophotometry,ferrizine colorimetry and o-phenanthroline spectrophotometry were used to detect iron content in two kinds of culture media(beef trypsin digestion liquid and 5% polypeptone),and the detection results of the three methods were compared.Results The complex of iron and sulfosalicylic acid showed the maximum absorbance at the wavelength of 425 nm;There was a good linear relationship between the absorbance and concentration of iron ion in the range of 1～0.05 μg/mL,the detection limit was 0.05 μg/mL,and the standard equation was:Y=0.027 9 X+0.046 1,R~2> 0.99;The coefficients of variation(CVs) of A_(425) value of each concentration of standards measured every 5 min were less than 5%;Low(0.05 μg/mL),medium(0.5 μg/mL)and high concentration(1 μg/mL) of Fe~(3+) standard solutions were continuously determined for 3 times.The CVs of 9groups of each concentration measured in parallel were all less than 5% and the recovery rates were higher than 95%;Ca~(2+),Mg~(2+),K~+,Na~+,15 μL of sulfo salicylic acid(20%) and 50 μL of ammonia hydroxide(1:1) showed no interference in the method;The results of toxin-producing medium were consistent with those of diphtheria bacteria;The results of the three detection methods were consistent.Conclusion The developed spectrophotometric method with sulfo salicylic acid can determine the content of trace iron ions in diphtheria toxin medium accurately and effectively.
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ABSTRACT The aim of this study was to evaluate tooth color in dental students at the University of Buenos Aires, Argentina. The participants were 184 students (157 women and 27 men) aged 21 to 33 years, mean age 24.45 (SD 2.79) years, who were in the fourth year of their dental degree. They agreed to participate through an informed consent. Exclusion criteria were: having undergone a bleaching treatment within the previous six months, presence of total or partial peripheral restoration, pigmentations, fracture, carious and non-carious lesions or absence of the right upper central incisor (1.1). A dental prophylaxis procedure was performed on the buccal surface of each 1.1 tooth with a prophylaxis brush (TDV) mounted on a low-speed rotary instrument Kavo 2068 CHC (Germany) micromotor and a Kavo LUX K201(Germany) contra-angle. Shade was measured in the middle third of each 1.1 tooth, by the same observer, using a VITA Easyshade V spectrophotometer (Zahnfabrikn Bad Säckingen, Germany), which was calibrated before each determination according to manufacturer's instructions, in the same dental unit (Sino S2316), with natural illumination, in the same time slot, without using the dental unit lamp. The results were recorded in an ad-hoc form and rates and confidence interval were obtained. Shade prevalence percentages (95% CI) were: A1: 46.2 (38.83 - 53.68); followed by A2 and B2, both with 17.39 (12.21 - 23.66); A3: 6.52 (3.41-11.11); B1: 4.35 (1.9-8.39); D2: 2.72 (0.89 - 6.23); B3: 2.17 (0.60-5.47) and C2: 1.09 (0.13-3.87); D3, C3, A3.5 and A4: 0.54 (0.01-2.99). Shades D1 and C1 were not determined in any subject. Within the conditions of this study, A1 was the most prevalent shade in central incisors, followed by A2 and B2.
RESUMEN El objetivo de este estudio fue evaluar la prevalencia de color dental en estudiantes de odontología de la Universidad de Buenos Aires (UBA). Los participantes fueron 184 estudiantes de cuarto año de la carrera de Odontología (157 mujeres y 27 hombres) de entre veintiuno y treinta tres años, con un promedio de edad de 24,45 (DE 2,79) años que aceptaron participar mediante consentimiento informado. Criterios de exclusión: quienes hayan recibido blanqueamiento en los últimos seis meses, tenían una restauración periférica total o parcial, pigmentaciones, fractura, lesiones cariosas y/o no cariosas en el incisivo central superior derecho (1.1) o éste estaba ausente. Se realizó profilaxis dental en la superficie bucal de cada 1.1 con un cepillo ad-hoc (TDV) montado en un micromotor de baja velocidad Kavo 2068 CHC (Alemania) y un contra-ángulo Kavo LUX K201 (Alemania). La medición del color se llevó a cabo en el tercio medio de cada 1.1, por el mismo observador, en la misma clínica dental, con iluminación natural en la misma franja horaria y sin utilizar la lámpara del equipo dental. Se utilizó un espectrofotómetro VITA Easyshade V (Zahnfabrikn Bad Säckingen, Alemania) que se calibró antes de cada determinación de acuerdo con las instrucciones del fabricante. Los resultados se registraron en una planilla ad-hoc y se obtuvieron tasas e intervalos de confianza. Prevalencia de colores % (IC 95%): A1: 46,2 (38,83 - 53,68), seguido de A2 y B2 ambos con 17,39 (12,21 - 23,66), A3: 6,52 (3,41-11,11), B1: 4,35 ( 1,9- 8,39), D2: 2,72 (0,89 - 6,23), B3: 2,17 (0,60-5,47) y C2: 1,09 (0,13- 3,87); D3, C3, A3.5 y A4: 0.54 (0.01-2.99) D1 y C1 no se determinaron en ningún sujeto. Dentro de las condiciones de este estudio A1 fue el color más prevalente en los incisivos centrales de estudiantes de odontología, seguido de A2 y B2.
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En el presente trabajo se realiza la estandarización del procedimiento espectrofotométrico de determinación de polisacárido capsular e intermedios de Neisseria meningitidis serogrupo X, mediante la determinación de los grupos fosfodiéster presentes en su estructura, por el método de Chen. Se realizó un análisis de los siguientes criterios para la estandarización: linealidad, precisión (repetibilidad y precisión intermedia) y exactitud. Se demostró mediante el diseño experimental y los procedimientos estadísticos empleados que el método es lineal (r > 0,99), el coeficiente de variación del factor respuesta < 5 por ciento, la desviación estándar relativa de la pendiente < 2 por ciento, no existiendo diferencia estadísticamente significativa entre el intercepto de la ecuación con respecto a cero; exacto, porque no existe diferencia estadísticamente significativa entre la concentración determinada en un material de trabajo y su concentración nominal; también demostró ser repetible, pues el coeficiente de variación de las concentraciones de la muestra evaluada (2,44; 2,43; 0,88 por ciento para las concentraciones bajas, medias y altas, respectivamente) es inferior al 3 por ciento y no existen diferencias estadísticamente significativas entre las medias de los resultados obtenidos por dos analistas, evaluados durante cuatro días a tres niveles de concentración. La precisión intermedia es satisfactoria(AU)
The present work comprises the standardization a spectrophotometric procedure for assessing Neisseria meningitidis, serogroup X capsular polysaccharide and their intermediates of modification, the phosphodiesters groups present in its structure, based on Chen method. An analysis of the following standardization criteria was performed: linearity, precision (repeatability and intermediate precision) and accuracy. It was demonstrated through the experimental design and the statistical procedures used that the method is linear (r > 0.99), the coefficient of variation of the response factor < 5 percent, the relative standard deviation of the slope < 2 percent, with no statistically significant difference between the intercept of the equation with respect to zero; exact, because there is no statistically significant difference between the concentration determined in a work material and its nominal concentration; it also proved to be repeatable, because the coefficient of variation of the concentrations of the sample (2.44; 2.43; 0.88 percent for low, medium and high concentrations respectively) is less than 3 percent and there is no statistically significant difference between the means of the results obtained by two analysts, evaluated for four days at three concentration levels. Its intermediate precision was satisfactory(AU)
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Humans , Male , Female , Reference Standards , Spectrophotometry/methods , Virulence Factors , Meningococcal Infections/diagnosis , Meningococcal Infections/epidemiology , Phosphodiesterase InhibitorsABSTRACT
Solvatochromic dyes are probes to detect variations on the dipole moment of solvents after the insertion of homeopathic potencies. Recent studies have shown they can be useful tools in laboratory and field studies to detect the activity of homeopathic remedies.Objective: Determine whether solvatochromic dyes can be a diagnostic tool for cells infected by different agents and/or markers to identify the activity of homeopathic medicines. Methods: Ethilicum1cH, Siliceaterra6, 30, 200cH; Zincummetallicum6, 30, 200cH and Phosphorus6, 30 and 200cH were analyzed by pouring the samples (in a 1:60 rate) into a series of seven dyes (rhodamine, ET 33, ET 30, coumarin 7, NN DMIA, Nile red, methylene violet) diluted in absolute ethanol using pre-established working concentrations. Oscillations of dye absorbance were observed at visible light spectrophotometry according to the remedy and potency. Water and succussed water were used as controls. In a second moment, the absorbance profile of the remedies will be compared with those of biological samples (supernatants) and checked with the biological effect previously obtained from each treatment.Supernatants of RAW 264.7 macrophages stimulated by Calmette-Guérin bacilli (BCG) or infected with Encephalitozoon cuniculiwill be analyzed. Results: Preliminary results have shown that Siliceaterra6cH, Phosphorus30 and 200cH and Zincummetallicum6, 30 and 200cH reduced the absorbance of methylene violet (p=0.01). Repetitions and analysis of supernatants are expected to be performed in the next steps of the study. Future perspectives: Establish a pattern of reactivity of the studied medicines with different dyes and the putative relation with the corresponding supernatants, as an attempt to obtain a "physicochemical signature" for each kind of infection and/or treatment.
Subject(s)
Biomarkers , Homeopathic Remedy , Coloring AgentsABSTRACT
O objetivo deste trabalho foi analisar e correlacionar os resultados de qualidade do leite cru refrigerado de dez propriedades rurais de Viçosa (MG) obtidos por métodos de referências do Ministério da Agricultura, Pecuária e Abastecimento e por espectrofotômetros de luz infravermelha em três laboratórios (A, B e C) credenciados pelo mesmo órgão de fiscalização. As amostras de leite foram analisadas quanto à contagem bacteriana, contagem de células somáticas (CCS) e teores de gordura, proteína e extrato seco desengordurado (ESD). Não houve discordância de amostras de leite quanto aos teores de proteína e gordura. Porcentagens diferentes de discordância foram observadas entre os resultados dos laboratórios e método de referência quanto à CCS, contagem bacteriana e teores de ESD. Os teores médios de proteína dos laboratórios A e B e os teores médios de ESD de todos laboratórios não foram estatisticamente iguais (p<0,05) aos teores obtidos pelo método de referência. Os teores de gordura obtidos no laboratório B não tiveram correlação estatística (p>0,05) com os teores obtidos pelo método de referência. Observou-se que as CCS e contagens bacterianas médias de todos os laboratórios foram estatisticamente iguais (p>0,05) e correlacionadas (p<0,05) às contagens médias obtidas pelos métodos de referência. Conclui-se que os teores de proteína em dois laboratórios e ESD em todos os laboratórios não são equivalentes com os métodos de referência do MAPA. É importante que os laboratórios revejam a calibração dos seus equipamentos quanto à quantificação dos teores de sólidos do leite.
The objective of this study was to analyze and to correlate the results of refrigerated raw milk quality in ten farms of Viçosa (MG). The milk was analyzed by the Ministério da Agricultura, Pecuária e Abastecimento standard methods and by infrared spectrophotometers in three laboratories (A, B and C) accredited by the same institution. The milk samples were analyzed for bacterial counts, somatic cell count (SCC) and fat, protein and solids not fat (SNF) tenors. There were no disagreement milk samples as the protein and fat tenors. Different percentages of disagreement were observed between the results of laboratory and standard method as the SCC, bacterial count and SNF tenor. The protein mean tenor of A and B laboratories and the SNF mean tenor of all laboratories were not statistically equal (p<0.05) the tenors obtained by standard method. The fat tenors obtained in B laboratory were not statistically correlated (p>0.05) with tenors obtained by the standard method. It was observed that the means of SCC and bacterial counts of all laboratories were statistically the same (p>0.05) and correlated (p<0.05) to the means counts obtained by standard methods. It is concluded that the protein tenors in two laboratories and SNF in all laboratories are not equivalent with the reference methods of MAPA. It is important that laboratories review the calibration of the equipment on the quantification of milk solids tenors.
Subject(s)
Quality Control , Spectrophotometers , Food Quality Standards , Milk/standards , Bacterial Load/standards , Raw Foods/analysisABSTRACT
Objective:To compare the detection success rates (DSRs) of different kinds of near-infrared spectrum non-invasive hemoglobin monitors in high-altitude environments.Methods:One hundred and forty-four healthy volunteers of either sex, aged 18-50 yr, were assigned to one of 3 groups using a random number table method: simulated high-altitude 3 500 meter group ( n=35), 4 000 meter group ( n=55) and 4 500 meter group ( n=54). Hemoglobin was detected by Radical-7, NW-9002SHM, A5 and TensorTip MTX type hemoglobin monitors in plain environment and simulated environment at different altitudes, and the DSRs were compared.Logistic regression analysis was conducted to identify the risk factors affecting the success rate of instrument detection, and the cut-off value was determined by ROC curve and the Youden index. Results:In the simulated high-altitude environment of 3500, 4000 and 4500 m, the DSR of TensorTip MTX was significantly higher than that of Radical-7, NW-9002SHM and A5 ( P<0.001), and there was no significant difference in the DSR among Radical-7, NW-9002SHM and A5 ( P>0.05). Low SpO 2 was the main factor affecting the DSRs of the Radical-7, NW-9002SHM and A5 type hemoglobin monitor in high-altitude environment ( P<0.001), and the cut-off value of SpO 2 in determining the success of detection was 88.5%, 87.5% and 89.5%, respectively.The DSR of TensorTip MTX was not affected by low SpO 2. Conclusions:The DSR of TensorTip MTX hemoglobin monitor is minimally affected by the high-altitude environment and can be preferred in the absence of oxygen supply; when Radical-7, NW-9002SHM or A5 hemoglobin monitor applied in high-altitude environments, oxygen saturation needs to be increased to ensure a high DSR.
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Objective:To establish a method for determination of iodine in salt by arsenic-cerium catalytic spectrophotometry.Methods:The content of iodine in salt was detected by arsenic-cerium catalytic spectrophotometry with an automatic iodine analyzer. The standard curve linearity, detection limit, precision and accuracy of the method were evaluated. The iodine content of 20 edible salt samples was detected by the newly established method and direct titration, and the results were compared.Results:In the range of 0 - 150 μg/L standard curve, the correlation coefficient ( r) = - 0.999 9, and the detection limit was 1.4 mg/kg. The average iodine contents of iodine composition analysis standard materials GBW10006z and GBW10007z were 12.2 and 22.8 mg/kg ( n = 6), respectively, which were all within the given standard value ranges, and the relative standard deviations ( RSD) were 2.04% and 2.33%, respectively. Iodine composition analysis standard materials GBW10006b, GBW10007b, GBW10006v, GBW10007v, GBW10006z and GBW10007z measurement results (12.0, 24.6, 12.6, 22.8, 12.3, 23.2 mg/kg, n = 2) were all within the given standard value ranges, with good quality control. The iodine content of 20 edible salt samples was detected by arsenic-cerium catalytic spectrophotometry and direct titration, respectively, and the difference was not statistically significant ( t = 1.99, P = 0.060). Conclusion:Arsenic-cerium catalytic spectrophotometry has the characteristics of good linear relationship, low detection limit, good precision and high accuracy in determination of salt iodine content, which is suitable for popularization and application.
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Objective To establish a method for the determination of total polyphenols and catechins in betel nut polyphenols extract, and provide reference for the quality control of betel nut polyphenols extract. Methods The content of total phenol in betel nut extract was determined by ultraviolet spectrophotometry. The content of catechins was determined by HPLC. Results The linear range of total polyphenols in betel nuts extract was 9.8~58.8 μg/ml. The three components of catechin, epicatechin and protocatechuic acid were completely separated by HPLC, and the linear relationship was good in their respective ranges, with the recoveries between 99.17% and 101.67%, the RSD between 1.2% and 2.5%. Conclusion The established method is simple, stable and reliable, which could be used for the quantitative analysis of betel polyphenol extract, and provide experimental basis for the quality control of betel polyphenol extract.
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ABSTRACT Objective: This study aimed to assess the effects of three methods of adhesive remnant removal (carbide bur and low speed handpiece, carbide bur and high speed handpiece, and zircon-rich glass fiber reinforced composite bur), after orthodontic bracket debonding, on tooth color and enamel surface roughness. Methods: Ninety sound premolar teeth were selected. The baseline tooth color was assessed using Vita spectrophotometer. The teeth were subjected to bracket bonding processes and then randomly divided into three equal groups. In each group, composite remnant was removed by one of the three methods of adhesive removal, and the teeth were then subjected to color assessment again. To measure the surface roughness, a scanning electron microscope (SEM) with x400 magnification was used. Results: ANOVA showed that the effect of the three methods of adhesive remnant removal on ∆L, ∆b and ∆E was statistically significant (p=0.01), but without significant effect on ∆a. Comparison of the means showed that composite bur and high speed carbide bur yielded the highest ∆E (p=0.05), and had a significant difference when compared to carbide bur and low speed handpiece. The highest ∆L and ∆b values belonged to samples approached with composite bur and carbide bur with high speed handpiece, respectively. SEM analysis showed that the composite bur created a very smooth surface, compared to the other two methods. Conclusion: Zircon-rich glass fiber reinforced composite created the smoothest enamel surface and highest color change, when compared to the other two methods.
RESUMO Objetivo: O presente estudo teve como objetivo avaliar os efeitos de três métodos de remoção de adesivo remanescente (broca carbide e peça de mão em baixa rotação, broca carbide e peça de mão em alta rotação, e broca de compósito reforçado com fibra de vidro rica em zircônia), após a descolagem de braquetes ortodônticos, sobre a cor dos dentes e rugosidade superficial do esmalte. Métodos: Noventa pré-molares hígidos foram selecionados. A cor inicial dos dentes foi avaliada usando um espectrofotômetro Vita. Os dentes foram submetidos à etapa de colagem dos braquetes e, então, divididos aleatoriamente em três grupos. Em cada grupo, o adesivo remanescente foi removido usando um dos três métodos de remoção, e os dentes foram novamente submetidos à avaliação de cor. Para medir a rugosidade superficial dos dentes, foi usado um microscópio eletrônico de varredura (MEV) com aumento de 400x. Resultados: A ANOVA mostrou que os três métodos de remoção do adesivo remanescente tiveram efeito estatisticamente significativo (p=0,01) em ∆L, ∆b e ∆E, mas sem efeito significativo em ∆a. A comparação das médias mostrou que a broca de compósito e a broca carbide em alta rotação produziram o maior ∆E (p=0,05) e tiveram uma diferença significativa quando comparadas com a broca carbide e a peça de mão em baixa rotação. Os maiores valores de ∆L e ∆b foram encontrados, respectivamente, nos grupos com broca de compósito e broca carbide usando peça de mão em alta rotação. A análise MEV mostrou que o uso da broca de compósito resultou em uma superfície muito lisa, em comparação com os outros dois métodos. Conclusão: Em comparação aos outros métodos, a broca de compósito reforçado com fibra de vidro rica em zircônia criou a superfície de esmalte mais lisa e resultou em uma maior mudança de cor.
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ABSTRACT Objective To assess the effects of coloring beverages on the color stability of two types of hybrid ceramics with different surface treatments. Material and Methods 180 specimens of two hybrid ceramics (Vita Enamic and Mazic Duro) and a feldspathic ceramic (Vita Mark II) were prepared (n=60 in each group). Half of the discs in each group were glazed while the other was polished. The specimens were then divided into three subgroups and immersed in distilled water, carrot juice, and coffee. The overall color difference (∆E) was calculated based on CIE L*a*b* color space. Data were analyzed using three-way and one-way ANOVA; Tukey's honest significant difference was also done for pairwise comparisons (α=0.05). Results Vita Mark II specimens revealed less overall color changes compared to other groups. The ∆E of the glazed Vita Enamic specimens was greater than polished specimens following immersion in distilled water (p=0.03) and coffee (p=0.001), but it was not significant for carrot juice. The same results were obtained for polished Mazic Duro specimens. Relatively similar amounts of ∆E were recorded in polished and glazed subgroups of Vita Mark II. Conclusion The ∆E of hybrid ceramics was higher than Vita Mark II. Polishing could be recommended for surface treatment of hybrid ceramics instead of glazing, saving time and facilitating the process.
Subject(s)
Spectrophotometry/instrumentation , Surface Properties , Beverages , Color , Dental Cements , Distilled Water , Ceramics , Analysis of Variance , Dental Prosthesis , Computer-Aided Design/instrumentation , Coffee , Dental Porcelain , Coloring Agents , Fruit and Vegetable Juices , Iran/epidemiologyABSTRACT
Abstract Perindopril erbumine (Perindopril tert-butylamine salt) is a potent angiotensin-converting enzyme (ACE) inhibitor. It is used to treat the patients with hypertension and heart failure problems. A sensitive, inexpensive and precise analytical technique has been developed for the estimation of perindopril in bulk and formulations. The procedure involves the development of colour by forming an oxidative coupling reaction between drug (PPE) and reagent such as 2, 6-dichloroquinone-4-chlorimide (DCQC). The formed colored species were measured at (max=520 nm. The developed method showed linearity within the concentration limits of 25-75 µg mL-1. The linear correlation coefficient (r) and molar absorptivity were found to be 0.9999 and 3.285 x 103 mol-1cm-1. % Recovery ± SD values were in the range of 99.69 - 100.51 (+ 0.42 - ( 0.41) (n=3) which indicates the accuracy of the developed method. The interference of other excipients that are commonly present in formulations is found to be negligible. Precision and accuracy of the proposed method were confirmed by student t-test and F-tests at 95% confidence limits with (n-1) degrees of freedom. The validity parameters of proposed method were calculated by ICH guidelines
Subject(s)
Perindopril , Oxidative Coupling , Spectrophotometry/methods , Angiotensins/administration & dosage , Pharmaceutical Preparations , Chemistry, Pharmaceutical/classification , Heart FailureABSTRACT
【Objective】 To construct an in-vitro model of erythrocyte antibody-mediated complement activation, and establish quantitative detection methods based on flow cytometry and spectrophotometry, so as to explore the correlation of anti-body titers and complement activation speed, and provide a methodological basis for studying the adverse transfusion reactions of anti-body mediated complement hemolysis. 【Methods】 Mouse monoclonal antibody that recognized human C3b and fluorescent secondary antibody were used to label C3b fragments on erythrocytes, and the deposition of C3b fragments after complement activation was detected by flow cytometry. The absorbance at 540 nm of the supernatant in the complement activation reaction system was measured by spectrophotometry as the amount of hemoglobin released was related to the absorbance. 【Results】 The complement activation system was constructed according to the ratio of 3% red blood cell suspension (mixed for 6 people) 1∶anti-Tja 1∶complement 2. The repeatability was good (P value>0.05) as different red blood cell mixtures had been used to repeat the detection reaction system. When using 32×, 64× and 128× dilutions of anti-Tja mediated complement activation, the deposition of C3b fragments has been detected by flow cytometry at 30 s, 1 min and 2 min, respectively, and MFI peaked at 5 min, 10 min and 30 min, respectively. No obvious hemolysis has been observed within 1.5 h. 【Conclusion】 In vitro model of anti-Tja-mediated complement activation demonstrates the speed of complement activation is related to the concentration of antibody. At a certain antibody concentration, the speed of complement activation has been slowed down, and no obvious hemolysis observed.