Multiphotonic Ablation and Electro-Capacitive Effects Exhibited by Candida albicans Biofilms.

This work reports the modification in the homogeneity of ablation effects with the assistance of nonlinear optical phenomena exhibited by C. albicans ATCC 10231, forming a biofilm. Equivalent optical energies with different levels of intensity were irradiated in comparative samples, and significant changes were observed. Nanosecond pulses provided by an Nd:YAG laser system at a 532 nm wavelength in a single-beam experiment were employed to explore the photodamage and the nonlinear optical transmittance. A nonlinear optical absorption coefficient -2 × 10-6 cm/W was measured in the samples studied. It is reported that multiphotonic interactions can promote more symmetric optical damage derived by faster changes in the evolution of fractional photoenergy transference. The electrochemical response of the sample was studied to further investigate the electronic dynamics dependent on electrical frequency, and an electro-capacitive behavior in the sample was identified. Fractional differential calculations were proposed to describe the thermal transport induced by nanosecond pulses in the fungi media. These results highlight the nonlinear optical effects to be considered as a base for developing photothermally activated phototechnology and high-precision photodamage in biological systems.

Effects of amber LED on inflammatory and regulatory monocytes and lymphocytes.

The primary objective of the present study was to assess the impact of amber LED photobiomodulation (PBM) on human monocytes and lymphocytes that were polarized into proinflammatory and regulatory/reparative phenotypes. Human leukocytes were polarized with LPS or LPS + IL-4 for 2 h and irradiated after 2 and 6 h with amber LED (590 nm). Cell absorbance spectrum and gene and protein expression of IL-1ß, IL-6, IL-10, IL-17, TNF-α and IFNγ determined after 24 h. The results showed that irradiation did not significantly alter absorbance of non-polarized monocytes, whereas irradiated polarized monocytes presented reduction in absorbance in 625-850 nm region. Irradiated monocytes polarized with LPS + IL-4 presented reduction in absorbance in 600-725 nm region compared to non-irradiated group. Irradiated non-polarized lymphocytes presented absorbance peaks between 650 and 820 nm not seen in non-irradiated group. No difference was found in absorbance pattern of polarized lymphocytes after irradiation. Irradiation led to reduction in protein synthesis of IL-6 and TNFα in monocytes polarized to proinflammatory phenotype and increase in production of IL-17 in lymphocytes. Irradiation reduced production of IL-10 in monocytes and lymphocytes polarized to immunoregulatory phenotype. In conclusion, amber LED modulates light absorbance and expression of important cytokines in inflammatory/repair processes in monocytes and lymphocytes.

Enhancing the physicochemical stability and antioxidant activity of cape gooseberry calyx extract through nanoencapsulation in soy lecithin liposomes.

The focus of this study was on the development, physicochemical characterisation and evaluation of the antioxidant activity of cape gooseberry calyx extract loaded into nanoliposomal systems. Various nanoliposomes were prepared and optimised using the ethanol injection method and characterised based on particle size, polydispersity and zeta potential measurements. Subsequently, the encapsulation efficiency and in vitro release profile of the natural antioxidant extract (NAE) were evaluated, and its antioxidant activity was assessed using the oxygen radical absorbance capacity assay. The results revealed that NAE-loaded nanoliposomes described desired quality features (e.g., particle size of < 200 nm, polydispersity index of < 0.3, zeta potential of > -40 mV and encapsulation efficiency of ∼70%). Furthermore, it was found that NAE release is controlled by various stages, and its antioxidant activity improves by around 30% when loaded into the nanoliposomes, suggesting that it could be a promising antioxidant functional raw material.

Phenotypic Analysis of Fourier-Transform Infrared Milk Spectra in Dairy Goats.

The infrared spectrum of bovine milk is used to predict many interesting traits, whereas there have been few studies on goat milk in this regard. The objective of this study was to characterize the major sources of variation in the absorbance of the infrared spectrum in caprine milk samples. A total of 657 goats belonging to 6 breeds and reared on 20 farms under traditional and modern dairy systems were milk-sampled once. Fourier-transform infrared (FTIR) spectra were taken (2 replicates per sample, 1314 spectra), and each spectrum contained absorbance values at 1060 different wavenumbers (5000 to 930 × cm-1), which were treated as a response variable and analyzed one at a time (i.e., 1060 runs). A mixed model, including the random effects of sample/goat, breed, flock, parity, stage of lactation, and the residual, was used. The pattern and variability of the FTIR spectrum of caprine milk was similar to those of bovine milk. The major sources of variation in the entire spectrum were as follows: sample/goat (33% of the total variance); flock (21%); breed (15%); lactation stage (11%); parity (9%); and the residual unexplained variation (10%). The entire spectrum was segmented into five relatively homogeneous regions. Two of them exhibited very large variations, especially the residual variation. These regions are known to be affected by the absorbance of water, although they also exhibited wide variations in the other sources of variation. The average repeatability of these two regions were 45% and 75%, whereas for the other three regions it was about 99%. The FTIR spectrum of caprine milk could probably be used to predict several traits and to authenticate the origin of goat milk.

Estimation of Soluble Solids for Stone Fruit Varieties Based on Near-Infrared Spectra Using Machine Learning Techniques.

The quality control for fruit maturity inspection is a key issue in fruit packaging and international trade. The quantification of Soluble Solids (SS) in fruits gives a good approximation of the total sugar concentration at the ripe stage, and on the other hand, SS alone or in combination with acidity is highly related to the acceptability of the fruit by consumers. The non-destructive analysis based on Visible (VIS) and Near-Infrared (NIR) spectroscopy has become a popular technique for the assessment of fruit quality. To improve the accuracy of fruit maturity inspection, VIS−NIR spectra models based on machine learning techniques are proposed for the non-destructive evaluation of soluble solids in considering a range of variations associated with varieties of stones fruit species (peach, nectarine, and plum). In this work, we propose a novel approach based on a Convolutional Neural Network (CNN) for the classification of the fruits into species and then a Feedforward Neural Network (FNN) to extract the information of VIS−NIR spectra to estimate the SS content of the fruit associated to several varieties. A classification accuracy of 98.9% was obtained for the CNN classification model and a correlation coefficient of Rc>0.7109 for the SS estimation of the FNN models was obtained. The results reported show the potential of this method for a fast and on-line classification of fruits and estimation of SS concentration.

Estrategias para la evaluación de extractos de polifenoles en modelos in vitro de cáncer de vías digestivas / Strategies for Evaluation of Polyphenol Extracts on in vitro Models of Digestive Tract Cancer / Estratégias para a avaliação de extratos de polifenóis em modelos in vitro de câncer do sistema digestivo

Introducción: Los polifenoles son compuestos que se encuentran naturalmente en alimentos como frutas, verduras, té, vino y chocolates, a los que se les atribuyen beneficios a la salud humana por su capacidad antioxidante. El cáncer de las vías digestivas se encuentra entre la tercera y quinta causas de muerte para la población, por lo que se ha incrementado el interés por realizar los estudios dirigidos a encontrar compuestos polifenólicos que ayuden en su prevención o tratamiento. Objetivo: Identificar las estrategias disponibles para la evaluación de polifenoles en células de cáncer de vías digestivas. Metodología: Búsqueda de literatura en bases de datos como Ovid, Pubmed, Science Direct y Elsevier Journal. Se seleccionaron artículos en los cuales se reporta el efecto biológico de los polifenoles sobre líneas celulares de cáncer de vías digestivas publicados entre 2012 y 2022. Resultados: Varios estudios han reportado el uso de un buen número de líneas celulares como modelos in vitropara estudios de polifenoles en cáncer y han resaltado las líneas AGS y HT-29, además de técnicas para la caracterización de los polifenoles, como el ensayo 2,2-Difenil-I-Picril Hidrazilo (DPPH). Sin embargo, para evaluar el efecto biológico se identifican diversas pruebas que deben analizarse antes de su implementación. Conclusiones: En la literatura se identifica que existen varias alternativas y estrategias para la evaluación de extrac-tos vegetales en cultivos in vitro de cáncer de vías digestivas; no obstante, antes de pasar al diseño experimental, deben tenerse en cuenta una serie de consideraciones para garantizar la utilidad de los resultados.

Introduction: Polyphenols are compounds naturally found in foods such as fruits, vegetables, tea, wine and chocolates, and it was attributed with benefits to human health due to their antioxidant capacity. Cancer of the digestive tract is between the third and fifth cause of death for the population, increasing the interest in carrying out studies aimed at finding polyphenolic compounds that help in their prevention or treatment. Objective: Identify the available strategies for the evaluation of polyphenols in digestive tract cancer cells. Method: A literature search was performed in databases such Ovid, Pubmed, Science Direct and Elsevier Journal and selected articles reporting the biological effect of polyphenols on digestive tract cancer cell lines, published between 2012 and 2022. Results: Currently studies report the use of a good number of cell lines as in vitro models for poly-phenol studies in cancer highlighting the AGS and HT-29 lines, in addition to techniques for the characterization of polyphenols such as the α, α-diphenyl-ß-picrylhydrazyl DPPH assay, however, to evaluate the biological effect various tests are identified that should be analyzed before implemen-tation. Conclusions: The literature identifies that there are many alternatives and strategies for the evaluation of plant extracts in in vitro cultures of digestive tract cancer, however, before moving on to the experimental design, a number of considerations should be taken into account to ensure the usability of the results

Introdução: Os polifenóis são compostos encontrados naturalmente em alimentos como frutas, legumes, chá, vinho e chocolates, aos quais são atribuídos benefícios para a saúde humana devido à sua capacidade antioxidante. O câncer do sistema digestivo está entre a terceira e a quinta principais causas de morte na população, o que levou a um interesse crescente em estudos destinados a encon-trar compostos polifenólicos que ajudem a prevenir ou tratar esse tipo de câncer. Objetivo: Identificar as estratégias disponíveis para a avaliação dos polifenóis nas células cancerosas do sistema digestivo. Metodologia: Pesquisa bibliográfica em bases de dados como Ovid, Pubmed, Science Direct e Elsevier Journal. Foram selecionados artigos que relatam o efeito biológico dos polifenóis em linhas celulares de câncer do sistema digestivo, publicados entre 2012 e 2022. Resultados: Vários estudos relataram a utilização de várias linhas celulares como modelos in vitro para estudos de polifenóis no câncer destacando as linhas AGS e HT-29, bem como técnicas para a ca-racterização de polifenóis, como o ensaio 2,2-Difenil-I-Picril Hidrazil (DPPH). No entanto, para avaliar o efeito biológico, são identificados vários testes que devem ser analisados antes da sua aplicação. Conclusões: A literatura identifica que existem várias alternativas e estratégias para a avaliação de extratos de plantas em culturas in vitro de câncer do sistema digestivo; no entanto, antes de passar à concepção experimental, é necessário ter em conta uma série de considerações para garantir a uti-lidade dos resultados

Smart Spectrophotometric Methods for Concurrent Determination of Furosemide and Spironolactone Mixture in Their Pharmaceutical Dosage Forms

Abstract Simple, precise, accurate and specific spectrophotometric methods are progressed and validated for concurrent analysis of Furosemide (FUR) and Spironolactone (SPR) in their combined dosage form depend on spectral analysis procedures. Furosemide (FUR) in the binary mixture could be analyzed at its λmax 274 nm using its recovered zero order absorption spectrum using constant multiplication method (CM). Spironolactone (SPR) in the mixture could be analyzed at its λmax 238 nm by ratio subtraction method (RS). Concurrent determination for FUR and SPR in their mixture could be applied by amplitude modulation method (AM), absorbance subtraction method (AS) and ratio difference (RD). Linearity ranges of FUR and SPR were (2.0µg/mL-22.0 µg/mL) and (3.0µg/mL-30.0 µg/mL), respectively. Specificity of the proposed spectrophotometric methods was examined by analyzing the prepared mixtures in laboratory and was applied successfully for pharmaceutical dosage form analysis which have the cited drugs without additives contribution. The proposed spectrophotometric methods were also validated as per as the guidelines of ICH. Statistical comparison was performed between the obtained results with those from the official methods of the cited drugs, using one-way ANOVA, F-test and student t-test. The results are exhibiting insignificant difference concerning precision and accuracy

A two-in-one Janus NIR-II AIEgen with balanced absorption and emission for image-guided precision surgery.

Fluorescence imaging in the near-infrared II (NIR-II, 1000-1700 nm) region opens up new avenues for biological systems due to suppressed scattering and low autofluorescence at longer-wavelength photons. Nonetheless, the development of organic NIR-II fluorophores is still limited mainly due to the shortage of efficient molecular design strategy. Herein, we propose an approach of designing Janus NIR-II fluorophores by introducing electronic donors with distinct properties into one molecule. As a proof-of-concept, fluorescent dye 2 TT-m, oC6B with both twisted and planar electronic donors displayed balanced absorption and emission which were absent in its parent compound. The key design strategy for Janus molecule is that it combines the merits of intense absorption from planar architecture and high fluorescence quantum yield from twisted motif. The resulting 2 TT-m, oC6B nanoparticles exhibit a high molar absorptivity of 1.12 ⨯104 M-1 cm-1 at 808 nm and a NIR-II quantum yield of 3.7%, displaying a typical aggregation-induced emission (AIE) attribute. The highly bright and stable 2 TT-m, oC6B nanoparticles assured NIR-II image-guided cancer surgery to resect submillimeter tumor nodules. The present study may inspire further development of molecular design philosophy for highly bright NIR-II fluorophores for biomedical applications.

Effects of the phenotypic polarization state of human leukocytes on the optical absorbance spectrum.

This study evaluated the optical absorbance spectrum of human monocytes, neutrophils and lymphocytes polarized, or not, to the inflammatory or immunoregulatory phenotypes. Peripheral human blood leukocytes were isolated and polarized (10 ng/mL) with LPS or IL-4 + LPS for 2 hours. After polarization, cells were washed and incubated for an additional 24 hours (monocytes and lymphocytes) or 12 hours (neutrophils). Next, cells were collected to evaluate the optical absorbance spectrum. The three types of leukocytes exhibited absorbance in the region from 450 to 900 nm, with greater absorbance at wavelengths lower than 570 nm. Lymphocytes had a second region of greater absorbance between 770 and 900 nm. Inflammatory monocytes and lymphocytes showed increased absorbance of blue, green and yellow wavelengths (monocytes), as well as red and infrared wavelengths (monocytes and lymphocytes). Immunoregulatory polarization altered the absorbance of monocytes and lymphocytes very little. Neutrophils treated with LPS or LPS + IL-4 exhibited lower absorbance at wavelengths higher than 575 nm compared to untreated cells. The present findings showed that leukocytes exhibit greater absorbance in regions of the spectrum that have not been much used in photobiomodulation (PBM), and the polarization of these cells can affect their capacity to absorb light. Taken together, these results suggest new perspectives in the use of PBM in the clinical setting depending on the wavelengths and the stage of the inflammatory process.

Optical Investigation of Essential Oils Using Absorbance and Photoluminescence.

Essential oils are complex mixtures of organic substances with large commercial importance in the pharmaceutical, food, fragrance, and cosmetic industries due to their organoleptic and biological properties. Also, these materials are also luminescent what has taken several studies about its potential uses for the detection and quality control of essential oils, imaging, and for the investigation of the synergies of their constituents. Concerning this, the present work is dedicated to studying the optical properties of selected essential oils: citronella (Cymbopogon winterianus), Japanese mint (Mentha arvensis), clove bud (Syzygium aromaticum), and bergamot (Citrus bergamia). We carried out a comparative study of the photoluminescence and the ultraviolet-visible optical absorption (abs-UV-Vis) of these essential oils with their typical constituents. To inspect the effects of the intermolecular interactions on the optical response of these systems, mixtures between the essential oils constituents following the expected average percent mass fraction were also studied. From these experiments, the main results were bathochromic effects in the abs-UV-Vis spectra; excimer formation in citral, isopulegol, isomenthone, eugenol, and eugenyl acetate; excimer emission enhancing and specific solvent effect in the essential oils photoluminescence spectra. These results contribute to the knowledge of essential oils' applications, especially in the evaluation of components' interactions through a simple abs-UV-Vis assay.

Colostrum from primiparous Holstein cows shows higher antioxidant activity than colostrum of multiparous ones.

Antioxidant components of colostrum prevent oxidative cell damage caused by free radicals that could harm the calf's development. The relationship of antioxidant potential of colostrum with parity is not well defined and could enlighten the importance of these components for the neonate and for the protection of the intestinal epithelium. The purpose of this work was to determine the antioxidant potential of colostrum from primiparous and multiparous Holstein cows in a commercial dairy farm. Samples from the first milk secretion from primiparous (first lactation, n = 8) and multiparous (second and third lactations, n = 8) Holstein cows were collected after birth of calves for determination of immune and antioxidant factors. The cows sampled in this study were vaccinated during pregnancy in order to improve colostrum quality. Colostrum from primiparous cows showed higher values of ceruloplasmin activity, oxygen radical absorbance capacity (ORAC) and transferrin saturation index (TSI) than colostrum from multiparous cows (P < 0.05). The total iron binding capacity (TIBC) and transferrin concentration in the colostrum of primiparous cows showed a non-significant numerical decrease (P = 0.06) in relation to the value in the colostrum of multiparous cows. Concentration of proteins, immunoglobulin G, and activity of lactoperoxidase, lysozyme, glutathione peroxidase and catalase, in turn, did not differ (P > 0.05). Metabolic differences between primiparous and multiparous cows may have affected the antioxidative status of colostrum, since ORAC values were twice higher in first lactation cows. Lower values of transferrin and TIBC and higher TSI in colostrum from primiparous cows suggests a relationship between lower iron stock and higher antioxidant activity. Thus, this work indicates an important role of the antioxidant potential of colostrum for neonates from first-lactation cows. Additionally, the iron stock may be directly related to the higher antioxidant potential of the colostrum from primiparous cows, and further investigations are required.

Association between Serum Uric Acid Levels, Nutritional and Antioxidant Status in Patients on Hemodialysis.

PURPOSE: To determine the relationship between uric acid (UA) and nutritional and antioxidant status in hemodialysis (HD) patients, given that hyperuricemia could be an indicator of good nutritional status possibly because of the antioxidant properties of UA. METHODS: Cross-sectional study with 93 patients on HD. Hyperuricemia was considered as UA ≥6.0 mg/dL in females and ≥7.0 mg/dL in males. Nutritional variables were registered. Blood samples were taken before the dialysis session to determine oxidative damage as plasma malondialdehyde (MDA) content, and antioxidant capacity measuring 2,2-diphenyl-piclrylhidrazil radical (DPPH●) scavenging activity and oxygen radical absorbance capacity (ORAC) value. RESULTS: Patients with hyperuricemia had higher creatinine (11.9 vs. 10.5 mg/dL; p = 0.004), potassium (5.5 vs. 5.0 mg/dL; p = 0.014) levels; phase angle (5.8 vs. 4.9; p = 0.005), protein consumption (normalized protein nitrogen appearance, nPNA, 1.03 vs. 0.83; p = 0.013) than normouricemic patients. DPPH● scavenging activity was higher in hyperuricemic subjects (1.139 vs. 1.049 mM Trolox equivalents; p = 0.007); likewise, hyperuricemic subjects had less oxidant damage measured by MDA (10.6 vs. 12.7 nmol/mL; p = 0.020). Subjects with normouricemia were at higher risk of having a reactance to height (Xc/H) ratio less than 35 (OR 2.79; 95% CI, 1.1-7.017, p = 0.028); nPNA < 1.0 (OR 3.78; 95% CI, 1.4-10.2, p = 0.007), diagnosis of cachexia (OR 2.95; 95% CI, 1156-7.518, p = 0.021), potassium levels <5 (OR 2.97; 95% CI, 1.136-7.772, p = 0.023) and PA < 5.5° (OR 3.38; 95% CI, 1.309-8.749, p = 0.012.) Conclusions: Patients with hyperuricemia had higher antioxidant capacity and better nutritional status. Purines and protein restrictions in HD patients with hyperuricemia need to be reviewed individually for each patient. More studies are needed to stablish a cut point of UA levels in renal population.

Effects of natural light and depth on rates of photo-oxidation of dissolved organic carbon in a major black-water river, the Rio Negro, Brazil.

Systems rich in terrigenous dissolved organic carbon (DOC), like the Rio Negro, can contribute significant amounts of carbon dioxide back to the atmosphere and support important microbial communities. We investigated photo-oxidation in the Rio Negro: (1) the depth to which light causes complete photo-oxidation to CO2 and changes in DOC structure, (2) the daily rate of change of absorbance indices, (3) the relationship between sub-surface rates of photo-oxidation to CO2 and light exposure, (4) the areal rates of photo-oxidation, and (5) the stability of fluorophore signals. Experiments were run in an outdoor pool of Rio Negro water, under natural sunlight during the dry seasons of 2015 and 2018. In 2018, rates of complete photo-oxidation and changes in absorbance indices decayed exponentially, approaching their asymptotes between 9 and 15 cm depth. In 2015, direct absorbance indices ceased changing at 14 cm depth. Fluorescence of humic acid-like moieties continued to decrease, sometimes to 35-43 cm depth. This indicates that partial photo-oxidation of DOC, and thus interaction with the microbial community, occurs to greater depths than previously expected. Areal rates of CO2 production were 28.8 and 39.3 mg C m-2 d-1 (two experiments, October 2018). Sub-surface (1.1 cm) rates were strongly related to light levels, reaching a maximum of 0.68 mg C l-1 d-1 in September. Complete photo-oxidation ceased below 29.6 mW cm-2 d-1 UV radiation, providing a daily baseline for observable production of CO2. Absorbance indices changed by 9 to 14% d-1 at high light levels, except for R254/365 (4.4% d-1). Fluorophore emission ranges were stable between 2014 and 2018, indicating that emissions can be compared across time and space. This study contributes to better estimates and understanding of photo-oxidation in tropical, black-water rivers, which will be useful for carbon modelling.

Surface chemistry and spectroscopic studies of the native phenylalanine dehydrogenase Langmuir monolayer at the air/aqueous NaCl interface.

This study investigates the main aspects of the surface behavior of the native phenylalanine dehydrogenase (PheDH) enzyme at the air/aqueous interface employing a saline subphase to induce the enzyme surface activity. Surface chemistry experiments were performed in order to determine the surface packing and stability of the formed layer, while spectroscopic experiments provided information regarding its secondary structure conformation. It was found that the PheDH enzyme forms a fluid film, which is quite homogeneous throughout its entire compression, being stable for long periods of time with no significant evidence of aggregates or irreversible domains during interfacial compression/decompression processes. The main secondary structures of the interfacial PheDH film were accessed via in situ reflectance-absorbance infrared spectroscopy, indicating a majority presence of α-helices, which were maintained after the film transfer to solid muscovite supports. The immobilized films presented a homogeneous and regular deposition, with controlled roughness and a mean thickness in the range of 8-10 nm.

Microscopio como Lector de Absorbancia con Utilidad en Análisis Clínicos / Microscope as Absorbance Reader with Utility in Clinical Analysis

Resumen La descentralización de laboratorios clínicos, se encuentra en desarrollo, lo anterior ha llevado a diseñar instrumentos que ofrecen resultados rápidos, confiables y al lado del paciente, esta tendencia se le conoce como prueba en el punto de atención (point of core testing POCT) y brinda la posibilidad de dar un seguimiento inmediato al padecimiento. El objetivo de esta investigación fue la implementación de un medidor de absorbancia, empleando la estructura de un microscopio óptico, al cual se le ha adaptado un filtro de luz, y una cámara digital. Lo anterior permite obtener valores de intensidad promedio de imágenes sólidas microscópicas de reacciones enzimáticas, y a partir de ellas estimar absorbancia o concentración. Como resultados se presentan rectas de calibración de absorbancia y mediciones de concentraciones para los casos de violeta de genciana, un kit de glucosa oxidasa y muestras problemas de pacientes voluntarios. Concluimos que existe un error de medición menor de ±1mg/dL comparados con las mediciones de un lector de placas de Elisa y un analizador de química sanguínea semiautomatizado. Teniendo en cuenta lo anterior el sistema resulta ser una alternativa viable para la estimación de absorbancia y aumenta la funcionalidad de microscopios ópticos en clínicas de salud.

Abstract The decentralization of clinical laboratories is under development, which has led to the design of instruments that offer fast, reliable and patient-side results, this trend is known as point of core testing (POCT) and It offers the possibility of giving an immediate follow-up to the disease. The objective of this investigation was the implementation of an absorbance meter, using the structure of an optical microscope, to which a light filter and a digital camera have been adapted. This allows to obtain values of average intensity of solid images of enzymatic reactions, and from them to estimate absorbance or concentration. As results, we present absorbance calibration lines and concentration measurements for cases of gentian violet, a glucose oxidase kit and samples of volunteer patients. We conclude that there is a measurement error of less than ± 1mg / dl compared with the measurements of an Elisa plate reader and a semi-automated blood chemistry analyzer. Taking into account the above, the system turns out to be a viable alternative for estimating absorbance and increasing the functionality of optical microscopes in health clinics.

Induction of pigment production through media composition, abiotic and biotic factors in two filamentous fungi.

In addition to plant-derived, fungal pigments have become an alternative in respect to synthetic ones. Besides Monascus sp., several pigment-producing fungi do not have culture conditions well-established yet. In this research, media composition, light wavelength and co-culture were evaluated, results were reported in Absorbance Units per gram of biomass (AU/Bgr). For Fusarium oxysporum a C:N ratio above 7 was advantageous, using both complex and defined media; blue LED light increased the AU/Bgr value from 18013 to 344; co-culture did not enhance pigment production. In Aspergillus chevalieri a high C:N ratio with glucose as carbon source was ideal. When exposing cultures to light, UV and red light gave the highest pigmentation; moreover, differential UV-VIS spectra in all wavelengths suggested production of additional pigments. Particularly a pigment observed when cultured in green light was also found in co-culture with yeast and there was an improvement of AU/Bgr value of 52549%. This is the first report regarding light effect and co-culture for these fungi, as well as C:N ratio for A. chevalieri.

Nitrogen-improved photosynthesis quantum yield is driven by increased thylakoid density, enhancing green light absorption.

A nitrogen supply is necessary for all plants. The multifaceted reasons why this nutrient stimulates plant dry weight accumulation are assessed herein. We compared tomato plants grown in full sunlight and in low light environments under four N doses and evaluated plant growth, photosynthetic and calorimetric parameters, leaf anatomy, chloroplast transmission electron microscopy (TEM) and a high resolution profile of optical leaf properties. Increases in N supplies allow tomato plants to grow faster in low light environments (91.5% shading), displaying a robust light harvesting machinery and, consequently, improved light harvesting efficiency. Ultrastructurally, high N doses were associated to a high number of grana per chloroplast and greater thylakoid stacking, as well as high electrodensity by TEM. Robust photosynthetic machinery improves green light absorption, but not blue or red. In addition, low construction and dark respiration costs were related to improved total dry weight accumulation in shade conditions. By applying multivariate analyses, we conclude that improved green light absorbance, improved quantum yield and greater palisade parenchyma cell area are the primary components that drive increased plant growth under natural light-limited photosynthesis.

Comparative study between the hemocytometric and spectrophotometric methods for measuring the sperm concentration of young Nelore bulls / Estudo comparativo entre o método hematocitométrico e o uso do espectrofotômetro para mensurar a concentração espermática de touros jovens da raça Nelore

Determination of sperm concentration using the Neubauer chamber (hemocytometric method) is a direct method for counting cells and also the most reliable. However, the process is time-consuming rendering it the least practical method when large numbers of ejaculates need to be processed. The spectrophotometer measures sperm concentrations as optical density and its main advantages are practicality and speed. This paper aimed to compare the results between evaluators using the hemocytometric method and the spectrophotometer for measuring sperm concentrations in young Nelore bulls. In total, 73 ejaculations from 20 young Nelore bulls were collected by electroejaculation. After soundness examination, 10 μL of the semen was diluted in 2 mL saline formaldehyde for measuring the sperm concentration per mL by the hemocytometric method (measured by three different evaluators) and the spectrophotometer method at 550 nm wavelength. No differences were detected in the results of sperm concentration measurements per mL among the evaluators using the hemocytometric method and the spectrophotometer (P > 0.05). The intraclass correlation was high (0.9), showing high replicability among the evaluator measurements. These results demonstrate that measurements performed using the spectrophotometer are reliable and can substitute the hemocytometric method in future for performing sperm concentration measurements in young Nelore bulls, thus improving and standardizing the techniques used in andrology laboratories.

A determinação da concentração espermática pela câmara de Neubauer (método hematocitométrico) é um método direto para contar células, e também é o mais confiável. Entretanto, o processo é demorado, o que o torna um método menos prático quando a quantidade de ejaculados a ser processado é muito grande. O espectrofotômetro é um dispositivo que mede a concentração de espermatozoides através da densidade óptica, e as suas principais vantagens são a sua praticidade e sua velocidade. O objetivo deste trabalho foi comparar os resultados entre os avaliadores no método hematocitométrico e o espectrofotômetro para medir a concentração de espermatozoides no ejaculado de touros jovens da raça Nelore. Um total de 73 ejaculações de 20 touros jovens da raça Nelore foram coletados por meio de eletroejaculação. Após exame andrológico, 10μL do sémen foram diluídos em 2 mL de solução salina de formaldeído para medir a concentração de espermatozoides por mL, utilizando o método hematocitométrico (medido por três diferentes avaliadores) e utilizando o método do espectrofotómetro com comprimento de onda de 550 nm. Não foram detectadas diferenças nos resultados de medição de concentração de espermatozoides por mL entre os avaliadores medidos pelo método hematocitométrico e espectrofotômetro (P > 0,05). A correlação intraclasse foi alta (0,9), mostrando uma alta replicabilidade entre as medidas das avaliações. Com os resultados do presente experimento, pode-se afirmar que a mensuração realizada pelo espectrofotômetro é confiável, e pode, no futuro, substituir o método hematocitométrico para realizar as mensurações de concentração de espermatozoides no ejaculado de touros jovens da raça Nelore, melhorando e padronizando as técnicas usadas em laboratórios andrologia.

Comparative study between the hemocytometric and spectrophotometric methods for measuring the sperm concentration of young Nelore bulls / Estudo comparativo entre o método hematocitométrico e o uso do espectrofotômetro para mensurar a concentração espermática de touros jovens da raça Nelore

Determination of sperm concentration using the Neubauer chamber (hemocytometric method) is a direct method for counting cells and also the most reliable. However, the process is time-consuming rendering it the least practical method when large numbers of ejaculates need to be processed. The spectrophotometer measures sperm concentrations as optical density and its main advantages are practicality and speed. This paper aimed to compare the results between evaluators using the hemocytometric method and the spectrophotometer for measuring sperm concentrations in young Nelore bulls. In total, 73 ejaculations from 20 young Nelore bulls were collected by electroejaculation. After soundness examination, 10 μL of the semen was diluted in 2 mL saline formaldehyde for measuring the sperm concentration per mL by the hemocytometric method (measured by three different evaluators) and the spectrophotometer method at 550 nm wavelength. No differences were detected in the results of sperm concentration measurements per mL among the evaluators using the hemocytometric method and the spectrophotometer (P > 0.05). The intraclass correlation was high (0.9), showing high replicability among the evaluator measurements. These results demonstrate that measurements performed using the spectrophotometer are reliable and can substitute the hemocytometric method in future for performing sperm concentration measurements in young Nelore bulls, thus improving and standardizing the techniques used in andrology laboratories.(AU0

A determinação da concentração espermática pela câmara de Neubauer (método hematocitométrico) é um método direto para contar células, e também é o mais confiável. Entretanto, o processo é demorado, o que o torna um método menos prático quando a quantidade de ejaculados a ser processado é muito grande. O espectrofotômetro é um dispositivo que mede a concentração de espermatozoides através da densidade óptica, e as suas principais vantagens são a sua praticidade e sua velocidade. O objetivo deste trabalho foi comparar os resultados entre os avaliadores no método hematocitométrico e o espectrofotômetro para medir a concentração de espermatozoides no ejaculado de touros jovens da raça Nelore. Um total de 73 ejaculações de 20 touros jovens da raça Nelore foram coletados por meio de eletroejaculação. Após exame andrológico, 10μL do sémen foram diluídos em 2 mL de solução salina de formaldeído para medir a concentração de espermatozoides por mL, utilizando o método hematocitométrico (medido por três diferentes avaliadores) e utilizando o método do espectrofotómetro com comprimento de onda de 550 nm. Não foram detectadas diferenças nos resultados de medição de concentração de espermatozoides por mL entre os avaliadores medidos pelo método hematocitométrico e espectrofotômetro (P > 0,05). A correlação intraclasse foi alta (0,9), mostrando uma alta replicabilidade entre as medidas das avaliações. Com os resultados do presente experimento, pode-se afirmar que a mensuração realizada pelo espectrofotômetro é confiável, e pode, no futuro, substituir o método hematocitométrico para realizar as mensurações de concentração de espermatozoides no ejaculado de touros jovens da raça Nelore, melhorando e padronizando as técnicas usadas em laboratórios andrologia.(AU)

Absorbance detector for high performance liquid chromatography based on a deep-UV light-emitting diode at 235nm.

In this communication, we describe a flow-through optical absorption detector for HPLC using for the first time a deep-UV light-emitting diode with an emission band at 235nm as light source. The detector is also comprised of a UV-sensitive photodiode positioned to enable measurement of radiation through a flow-through cuvette with round aperture of 1mm diameter and optical path length of 10mm, and a second one positioned as reference photodiode; a beam splitter and a power supply. The absorbance was measured and related to the analyte concentration by emulating the Lambert-Beer law with a log-ratio amplifier circuitry. This detector showed noise levels of 0.30mAU, which is comparable with our previous LED-based detectors employing LEDs at 280 and 255nm. The detector was coupled to a HPLC system and successfully evaluated for the determination of the anti-diabetic drugs pioglitazone and glimepiride in an isocratic separation and the benzodiazepines flurazepam, oxazepam and clobazam in a gradient elution. Good linearities (r>0.99), a precision better than 0.85% and limits of detection at sub-ppm levels were achieved.