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1.
J Surg Case Rep ; 2024(8): rjae563, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39220165

RESUMO

Isolated cuboid dislocation without fracture is a rare injury, and there is a lack of literature describing its treatment. Studies report the use of closed or open reduction, with Kirschner wire fixation in the treatment of these injuries. This case report presents the clinical condition of a 24-year-old male patient who arrived at the emergency department with an isolated dislocation of the right foot cuboid bone without the presence of a fracture, after suffering trauma during a football game. Open reduction was performed in the surgical center with stabilization and fixation using a Kirschner wires. The patient showed an excellent response to the treatment, with no loss of the foot's range of motion.

2.
Healthcare (Basel) ; 12(13)2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38998860

RESUMO

One expanding area of bioinformatics is medical diagnosis through the categorization of biomedical characteristics. Automatic medical strategies to boost the diagnostic through machine learning (ML) methods are challenging. They require a formal examination of their performance to identify the best conditions that enhance the ML method. This work proposes variants of the Voting and Stacking (VC and SC) ensemble strategies based on diverse auto-tuning supervised machine learning techniques to increase the efficacy of traditional baseline classifiers for the automatic diagnosis of vertebral column orthopedic illnesses. The ensemble strategies are created by first combining a complete set of auto-tuned baseline classifiers based on different processes, such as geometric, probabilistic, logic, and optimization. Next, the three most promising classifiers are selected among k-Nearest Neighbors (kNN), Naïve Bayes (NB), Logistic Regression (LR), Linear Discriminant Analysis (LDA), Quadratic Discriminant Analysis (QDA), Support Vector Machine (SVM), Artificial Neural Networks (ANN), and Decision Tree (DT). The grid-search K-Fold cross-validation strategy is applied to auto-tune the baseline classifier hyperparameters. The performances of the proposed ensemble strategies are independently compared with the auto-tuned baseline classifiers. A concise analysis evaluates accuracy, precision, recall, F1-score, and ROC-ACU metrics. The analysis also examines the misclassified disease elements to find the most and least reliable classifiers for this specific medical problem. The results show that the VC ensemble strategy provides an improvement comparable to that of the best baseline classifier (the kNN). Meanwhile, when all baseline classifiers are included in the SC ensemble, this strategy surpasses 95% in all the evaluated metrics, standing out as the most suitable option for classifying vertebral column diseases.

3.
Environ Sci Pollut Res Int ; 31(35): 48674-48686, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39037629

RESUMO

Contamination with traces of pharmaceutical compounds, such as ciprofloxacin, has prompted interest in their removal via low-cost, efficient biomass-based adsorption. In this study, classical models, a mechanistic model, and a neural network model were evaluated for predicting ciprofloxacin breakthrough curves in both laboratory- and pilot scales. For the laboratory-scale (d = 2.2 cm, Co = 5 mg/L, Q = 7 mL/min, T = 18 °C) and pilot-scale (D = 4.4 cm, Co = 5 mg/L, Q = 28 mL/min, T = 18 °C) setups, the experimental adsorption capacities were 2.19 and 2.53 mg/g, respectively. The mechanistic model reproduced the breakthrough data with high accuracy on both scales (R2 > 0.4 and X2 < 0.15), and its fit was higher than conventional analytical models, namely the Clark, Modified Dose-Response, and Bohart-Adams models. The neural network model showed the highest level of agreement between predicted and experimental data with values of R2 = 0.993, X2 = 0.0032 (pilot-scale) and R2 = 0.986, X2 = 0.0022 (laboratory-scale). This study demonstrates that machine learning algorithms exhibit great potential for predicting the liquid adsorption of emerging pollutants in fixed bed.


Assuntos
Celulose , Ciprofloxacina , Aprendizado de Máquina , Redes Neurais de Computação , Ciprofloxacina/química , Adsorção , Celulose/química , Saccharum/química , Poluentes Químicos da Água
4.
Environ Technol ; : 1-17, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38820593

RESUMO

This paper aimed to apply filamentous fungi (Penicillium oxalicum and Cunninghamella echinulata), the microalga Tetradesmus obliquus and their co-culture in advanced treatment (tertiary treatment) of cheese whey. The bioremediation process was carried out in agitated flasks and bubble column bioreactors with different concentrations of chemical oxygen demand (COD) (223-1663 mg L-1), total nitrogen (TN) (13-61 mg L-1), and total phosphorus (TP) (3-26 mg L-1). The results obtained in shaken flasks showed a superiority of the consortium compared to the systems with separated species. In this sense, the treatment was carried out in a bubble column reactor, and the consortium formed by the microalga and the fungus C. echinulata showed a greater efficiency (at a light intensity of 100 µmol m-2 s-1), promoting by the symbiosis to reach removal efficiencies of up to 93.7, 78.8 and 93.4% for COD, TN and TP, respectively; meeting Brazilian and European standards for discharge into water bodies. In addition, no pH adjustment was required during the co-culture treatment, demonstrating the buffering effect of using these two types of microorganisms. Therefore, the use of the consortium formed by T. obliquus and C. echinulata as a remediator was highly promising to promote the advanced treatment of cheese whey.


Dairy wastewater needs a polishing treatment stage after secondary treatmentThe microalga-fungus consortium met legislation requirementsCOD, nitrogen and phosphorus were efficiently removed by the consortiumNo pH control was applied during the biological treatment by the consortium.

5.
J Forensic Sci ; 69(3): 1025-1034, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38520078

RESUMO

The area of forensic chemistry has been growing and developing as a line of research due to the high demands of public safety that require increasingly reliable results due to their importance in criminalistics. In this way, the development of new technologies that help this area, whether in the identification and quantification of drugs or the fight against fraud, becomes promising. In this context, the present work explored the production of reference standards from the purification of cocaine/crack samples seized by the Civil Police of the State of Espírito Santo. Cocaine was purified using chromatographic techniques, and benzoylecgonine was synthesized from purified cocaine. All substances were characterized by ultra-high-resolution mass spectrometry and nuclear magnetic resonance. Homogeneity and stability studies were also performed with benzoylecgonine, and the results were evaluated using analysis of variance (ANOVA). Cocaine and benzoylecgonine showed purities of 98.37% and 96.34%, respectively. The homogeneity of the batch, short-term stability, and other parameters were also evaluated, which together indicate this proposal as promising in the development of reference standards for drugs of abuse from samples seized by the Brazilian forensic police.


Assuntos
Cocaína/análogos & derivados , Drogas Ilícitas , Espectrometria de Massas , Padrões de Referência , Humanos , Drogas Ilícitas/química , Espectroscopia de Ressonância Magnética , Toxicologia Forense , Brasil , Cromatografia Gasosa-Espectrometria de Massas
6.
Appl Microbiol Biotechnol ; 108(1): 160, 2024 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-38252281

RESUMO

Virus-like particles (VLPs) are nanometric structures composed of structural components of virions, keeping most of the cellular recognition and internalization properties, but are non-infective as they are deprived of their genetic material. VLPs have been a versatile platform for developing vaccines by carrying their own or heterologous antigenic epitopes. Moreover, VLPs can also be used as nanovessels for encapsulating molecules with therapeutic applications, like enzymes, nucleic acids, and drugs. Parvovirus B19 (B19V) VLPs can be self-assembled in vitro from the denatured major viral particle protein VP2 by equilibrium dialysis. Despite its fair productivity, this process is currently a time-consuming task. Affinity chromatography is used as an efficient step for concentration and purification, but it is only sometimes seen as a method that facilitates the oligomerization of proteins. In this research, we report a novel approach for the in vitro assembly of B19V VLPs through the immobilization of the denatured VP2 into an immobilized metal affinity chromatography (IMAC) column, followed by the on-column folding and the final VLP assembly upon protein elution. This method is suitable for the fast production of B19V VLPs. KEY POINTS: • Biotechnological applications for inclusion bodies • Efficient single-step purification and immobilization strategies • Rapid VLP assembly strategy.


Assuntos
Proteínas de Bactérias , Parvovirus B19 Humano , Parvovirus B19 Humano/genética , Bactérias , Biotecnologia , Cromatografia de Afinidade
7.
Mar Pollut Bull ; 199: 116005, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38219292

RESUMO

This study examines the mercury content in the marine matrices water column, surface sediment and benthic invertebrates of Coronel and Coliumo bays, central Chile, under winter and summer conditions. Coronel Bay has been subject to intense industrialization in the last three decades, while Coliumo Bay remains as a fisherman's cove and a popular summer tourism destination. Our results reveal significantly higher mercury concentrations in the three environmental matrices analyzed for Coronel Bay, while Coliumo Bay exhibits levels within the range considered natural. Moreover, the mercury levels in Coronel Bay exceed the optimal criteria for aquatic life, indicating a deterioration in environmental quality of this locality. Industrial development is identified as main factor explaining the differences observed between these two coastal water bodies. This study presents the most updated record of mercury levels in the Southeast Pacific and represents the first comprehensive evaluation of marine environmental matrices in two bays with divergent activities.


Assuntos
Mercúrio , Poluentes Químicos da Água , Mercúrio/análise , Chile , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Água do Mar , Água , Biota , Baías , Sedimentos Geológicos
8.
Bioprocess Biosyst Eng ; 47(2): 263-273, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38156992

RESUMO

The objective of this study was to develop a bioprocess for lactose hydrolysis in diverse dairy matrices, specifically skim milk and cheese whey, utilizing column reactors employing a core-shell enzymatic system featuring ß-galactosidase fused to a Cellulose Binding Domain (CBD) tag (ß-galactosidase-CBD). The effectiveness of reactor configurations, including ball columns and toothed columns operating in packed and fluidized-bed modes, was evaluated for catalyzing lactose hydrolysis in both skim milk and cheese whey. In a closed system, these reactors achieved lactose hydrolysis rates of approximately 50% within 5 h under all evaluated conditions. Considering the scale of the bioprocess, the developed enzymatic system was capable of continuously hydrolyzing 9.6 L of skim milk while maintaining relative hydrolysis levels of approximately 50%. The biocatalyst, created by immobilizing ß-galactosidase-CBD on magnetic core-shell capsules, exhibited exceptional operational stability, and the proposed bioprocess employing these column reactors showcases the potential for scalability.


Assuntos
Lactose , Leite , Animais , Lactose/química , Hidrólise , Leite/química , Leite/metabolismo , beta-Galactosidase/química , Fenômenos Magnéticos , Enzimas Imobilizadas/metabolismo
9.
J Exp Zool B Mol Dev Evol ; 342(4): 350-367, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38155515

RESUMO

In anurans, the vertebral column diverges widely from that of other tetrapods; yet the molecular mechanisms underlying its morphogenesis remain largely unexplored. In this study, we investigate the role of the homeologous uncx.L and uncx.S genes in the vertebral column morphogenesis of the allotetraploid frog Xenopus laevis. We initiated our study by cloning the uncx orthologous genes in the anuran Xenopus and determining their spatial expression patterns using in situ hybridization. Additionally, we employed gain-of-function and loss-of-function approaches through dexamethasone-inducible uncx constructs and antisense morpholino oligonucleotides, respectively. Comparative analysis of the messenger RNA sequences of homeologous uncx genes revealed that the uncx.L variant lacks the eh1-like repressor domain. Our spatial expression analysis indicated that in the presomitic mesoderm and somites, the transcripts of uncx.L and uncx.S are located in overlapping domains. Alterations in the function of uncx genes significantly impact the development and differentiation of the sclerotome and myotome, resulting in axial skeleton malformations. Our findings suggest a scenario where the homeologous genes uncx.L and uncx.S exhibit antagonistic functions during somitogenesis. Specifically, uncx.S appears to be crucial for sclerotome development and differentiation, while uncx.L primarily influences myotome development. Postallotetraploidization, the uncx.L gene in X. laevis evolved to lose its eh1-like repressor domain, transforming into a "native dominant negative" variant that potentially competes with uncx.S for the same target genes. Finally, the histological analysis revealed that uncx.S expression is necessary for the correct formation of pedicles and neural arch of the vertebrae, and uncx.L is required for trunk muscle development.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio , Proteínas de Xenopus , Xenopus laevis , Animais , Evolução Biológica , Somitos/metabolismo , Coluna Vertebral/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo
10.
Braz. J. Anesth. (Impr.) ; 73(6): 758-763, Nov.Dec. 2023. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1520378

RESUMO

Abstract Background: Reduced lumbar lordosis may make the process of identifying the intervertebral distance easier. The primary aim of this study was to measure the L3-L4 intervertebral space in the same patients undergoing spinal anesthesia in three different sitting positions, including the classic sitting position (CSP), hamstring stretch position (HSP) and rider sitting position (RSP). The secondary aim was to compare ultrasonographic measurements of the depth of the ligamentum flavum and intrathecal space in these three defined positions. Methods: This study is a single-blinded, prospective, randomized study. Ninety patients were included in final analysis. the patients were positioned on the operating table in three different positions to perform ultrasonographic measurements of the spinal canal. The intervertebral distance (IVD), the distance between the skin and the ligamentum flavum (DBSLF) and the intrathecal space (IS) were measured in the L3 -L4 intervertebral space in three different positions. Results: The RSP produced the largest mean distance between the spinous processes. The RSP yielded a significantly larger IVD than did the CSP (p < 0.001) and HSP (p < 0.001). The DBSP was larger in the CSP than in the HSP (p = 0.001). The DBSLF was significantly larger in the RSP than in the HSP (p = 0.009). Conclusions: Positioning the patient in the RSP significantly increased the intervertebral distance between L3 -L4 vertebrae compared to the CSP and HSP, suggesting easier performance of lumbar neuraxial block.


Assuntos
Humanos , Postura Sentada , Raquianestesia , Estudos Prospectivos , Vértebras Lombares/diagnóstico por imagem , Região Lombossacral/diagnóstico por imagem
11.
Injury ; 54 Suppl 6: 110723, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38143141

RESUMO

A proper evaluation of the narrowings and length of the anterior acetabular column would offer better predictability and precision for implant insertion in the case of an acetabular fracture. OBJECTIVE: To determine the diameter and length of the safety corridor of the anterior column of the acetabulum in patients with available pelvic computed tomography (CT), analyze the obtained measurements against those of a standard 6.5-mm implant, and verify possible sex differences regarding these measurements. A secondary aim was to develop a method for measurement of the anterior column of the acetabulum based on CT images. MATERIALS AND METHODS: In 200 CT scans of hemipelvises we measured the diameter of two areas of narrowing and the length of the safety corridor of the anterior column. The images were submitted to multiplanar reformatting adjusted to a plane orthogonal to the bone corridor, drawn at the level of the superior pubic ramus. RESULTS: Measurement #1 had a mean value of 8.12 (2.27) mm in the overall sample and median values of 9.03 (7.76-10.48) mm in men and 6.77 (5.44-7.19) mm in women. Measurement #2 had a mean value of 7.29 (2.19) mm and median values of 8.23 (7.18-9.82) mm in men and 5.9 (4.65-7.19) mm in women. Measurement #3 had a mean value of 109.53 (13.66) mm in the overall sample and median values of 117.17 (112.9-122.9) mm in men and 100.91 (90.95-111.17) mm in women (p<0.001 all three measurements). Measurement #1 was smaller than 6.5 mm in 22.5% of the patients (of whom 90% were women). Measurement #2 was smaller than 6.5 mm in 35% of the patients (of whom 80% were women). CONCLUSIONS: This study proposed an anatomic evaluation of the anterior column of the acetabulum using conventional CT images The areas of narrowing in the anterior column had an average of 8.12 mm at the level of the pubic tubercle and 7.29 mm at the level of the acetabular fossa. The mean length of the safety corridor was 109.53 mm. In 35% of the cases, a 6.5 mm percutaneous screw would have violated the cortical bone of the safety corridor.


Assuntos
Fraturas Ósseas , Fraturas do Quadril , Fraturas da Coluna Vertebral , Humanos , Masculino , Feminino , Fixação Interna de Fraturas/métodos , Projetos Piloto , Fraturas do Quadril/cirurgia , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Acetábulo/lesões , Parafusos Ósseos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia
12.
Injury ; 54 Suppl 6: 110579, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38143145

RESUMO

Antegrade fixation of posterior column fractures of the acetabulum is challenging due to the narrow corridor and risk of screw misplacement. Although both antegrade and retrograde lag screws have been previously described for posterior column fracture fixation, the literature lacks a standardized technique for correct and safe screw placement, especially in an antegrade fashion. This technical note aims to optimize intraoperative images during posterior screw insertion using the antegrade technique, according to predetermined landmarks to save surgical time, decrease radiation exposition, and prevent surgical complications.


Assuntos
Fraturas Ósseas , Fraturas do Quadril , Fraturas da Coluna Vertebral , Humanos , Fixação Interna de Fraturas/métodos , Fraturas Ósseas/diagnóstico por imagem , Fraturas Ósseas/cirurgia , Parafusos Ósseos , Acetábulo/diagnóstico por imagem , Acetábulo/cirurgia , Acetábulo/lesões
13.
Anal Chim Acta ; 1284: 341952, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37996153

RESUMO

BACKGROUND: One of the primary objectives in green analytical practices is the seamless integration of extraction and separation steps, resulting in the augmentation of both analytical throughput and method performance. Consequently, the exploration of prospective sorbent materials has drawn significant attention in the scientific community, particularly concerning the potential for online procedures. Employing the optimal sorbent material within an automated analytical approach holds the promise of elevating the precision of the analytical evaluation. Molecularly imprinted polymers (MIPs) excel in specific analyte interaction within complex matrices. However, MIPs' full potential was not widely exploring especially for online analytical methodologies. RESULTS: Here is presented a comprehensive overview of the current applications of MIPs as sorbent materials within integrated and automated separation methodologies applied to diverse matrices including biological, food, and environmental samples. Notably, their primary advantage, as evidenced in the literature, lies in their exceptional selectivity for the target analyte discussed according to the adopted synthesis protocol. Furthermore, the literature discussed here illustrates the versatility of MIPs in terms of modification with one or more phases which are so-called hybrid materials, such as molecularly imprinted monoliths (MIM), the molecularly imprinted ionic liquid polymer (IL-MIP), and restricted access to molecularly imprinted polymer (RAMIP). The reported advantages enhance their applicability in integrated and automated separation procedures, especially to the column switching methods, across a broader spectrum of applications. SIGNIFICANCE: This revision aims to demonstrate the MIP's potential as a sorbent phase in integrated and automated methods, this comprehensive overview of MIP polymers in integrated and automated separation methodologies can be used as a valuable guide, inspiring new research on developing novel horizons for MIP applications to have their potential emphasized in analytical science and enhanced to the great analytical methods achievement.

14.
Acta méd. colomb ; 48(3): e02, sept. 2023. tab
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1573690

RESUMO

Abstract Objetive: to describe the clinical and paraclinical characteristics of patients with osteoporotic vertebral fractures at a tertiary care university hospital in Manizales, from January 2018 to January 2022. Design: an observational, cross-sectional descriptive study was performed. Patients: patients with vertebral fractures seen on diagnostic imaging. Measurements: the clinical and sociodemographic characteristics and admission clinical and paraclinical test results were evaluated. Results: a total of 174 patients were found, 68.2% of whom were females; 89.4% had high co morbidity (a Charlson index score higher than 3), 54.6% had malnutrition, 60.1% had polypharmacy and 85.4% had insufficient milk product consumption. In half of the cases, the vertebral fracture was severe (>40% reduction in the vertebral body height, according to Genant), 19.8% had a prior fracture and 15.1% were receiving pharmacological treatment for osteoporosis. The bone profile findings showed decreased levels of albumin and vitamin D with elevated PTH. Conclusions: two-thirds of the patients with osteoporotic vertebral fractures are females, with high comorbidity and malnutrition. Most were not receiving pharmacological treatment for osteo porosis. (Acta Med Colomb 2022; 48. DOI:https://doi.org/10.36104/amc.2023.2759).


Resumen Objetivo: describir las características clínicas y paraclínicas de los pacientes con fractura ver tebral osteoporótica en un hospital universitario de tercer nivel de Manizales, entre enero de 2018 y enero de 2022. Diseño: se realizó un estudio observacional, transversal, de tipo descriptivo. Pacientes: pacientes con fracturas vertebrales evidenciadas en imágenes diagnósticas. Mediciones: se evaluaron las características clínicas, sociodemográficas, resultados clínicos y estudios paraclínicos al ingreso. Resultados: se identificaron 174 pacientes, 68.2% de sexo femenino, 89.4% con comorbilidad alta (puntuación mayor a tres según el índice de Charlson), 54.6% con malnutrición, 60.1% con polifarmacia y 85.4% con consumo inadecuado de lácteos. En la mitad de los casos la fractura ver tebral fue severa (disminución de la altura del cuerpo vertebral ≥40% según Genant), 19.8% tenían fractura previa y 15.1% recibía terapia farmacológica para osteoporosis. En cuanto al perfil óseo con hallazgos de valores disminuidos de albúmina y vitamina D con PTH elevada. Conclusiones: dos terceras partes de los pacientes con fracturas vertebrales osteoporóticas son de sexo femenino, con alta comorbilidad y malnutrición. La mayoría no recibían tratamiento farma cológico para osteoporosis. (Acta Med Colomb 2022; 48. DOI:https://doi.org/10.36104/amc.2023.2759).

15.
Environ Sci Pollut Res Int ; 30(43): 98362-98376, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37606782

RESUMO

Bacteria and archaea play a fundamental role in the biogeochemical cycles of organic matter, pollutants, and nutrients to maintain the trophic state of aquatic ecosystems. However, very little is known about the composition patterns of microbial communities in vertical distribution (water column) in freshwater lakes and their relationship with the physicochemical properties of water. "La Encantada" lake in the Lagunas de Montebello National Park (LMNP) is a site of interest due to the anthropogenic impact received and the little information about it. In this study, 3 sites were evaluated; samples were collected using 0-15 m deep water columns and analyzed using Illumina MiSeq sequencing technology based on the 16S rRNA gene. The physical parameters of pH, temperature, dissolved oxygen, electrolytic conductivity, and PO-4 were determined. The results revealed clear differences in the microbial composition of the water throughout the column; the most abundant phyla in bacterial communities were Proteobacteria (23.2%), Cyanobacteria (17.3%), and Bacteroidetes (17.2%), and for archaea were Crenarchaeota (35.9%) and Euryarchaeota (33.2%). PICRUSt metabolic inference analysis revealed that the main functional genes were related to cellular processes and biodegradation of xenobiotics, indicating an increasing trend of contaminants and residual discharges that may act as a precursor to alter microbial communities and stability of the lakes. At depths of 10 and 15 m, the microbial diversity was greater; likewise, the correlation between the physicochemical parameters and the microbial communities at the genus level showed that Chlorobaculum, Desulfomonile, and Candidatus Xiphinematobacter were favored by an increase in dissolved phosphates and by the decrease in pH and temperature. These results highlight that the microbial communities exhibit variation in their composition due to the effect of depth and physicochemical parameters, which could play a role as biological factors in the trophic states of a lake.


Assuntos
Archaea , Chlorobi , Archaea/genética , Lagos , Ecossistema , México , RNA Ribossômico 16S , Bactérias/genética , Água
16.
Molecules ; 28(13)2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37446660

RESUMO

Graphene oxide sheets fixed over silica particles (SiGO) and their modification functionalized with C18 and endcapped (SiGO-C18ec) have been reported as sorbents for extraction and analytical columns in LC. In this study, a SiGO column was selected as the extraction column and a SiGO-C18ec as the analytical column to study the applicability and limitations of a column-switching system composed exclusively of columns packed with graphene-based sorbents. Pyriproxyfen and abamectin B1a were selected as the analytes, and orange-flavored carbonated soft drinks as the matrix. The proposed system could be successfully applied to the pyriproxyfen analysis in a concentration range between 0.5 to 25 µg/mL presenting a linearity of R2 = 0.9931 and an intra-day and inter-day accuracy of 82.2-111.4% (RSD < 13.3%) and 95.5-99.8% (RSD < 12.7%), respectively. Furthermore, the matrix composition affected the area observed for the pyriproxyfen: the higher the concentration of orange juice in the soft drink, the higher the pyriproxyfen the signal observed. Additionally, the SiGO extraction column presented a life use of 120 injections for this matrix. In contrast, the proposed system could not apply to the analysis of abamectin B1a, and the SiGO-C18ec analytical column presented significant tailing compared to a similar approach with a C18 analytical column.


Assuntos
Grafite , Dióxido de Silício , Ivermectina
17.
Molecules ; 28(13)2023 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-37446765

RESUMO

This work presents a study on the application of wall open tubular column (WCOT) in liquid chromatography coupled with tandem mass spectrometry. Each process step reports the column preparation method in detail, subdivided into column pretreatment, silanization, stationary phase coating, and immobilization. Then, an evaluation of the parameters that can affect the efficiency of these columns was made. Atrazine, clomazone, and metolachlor were used as probes during this step. Factors such as stationary phase composition, length, internal diameter, stationary phase mass employed, and injection volume were investigated. In addition, with the help of Knox and Poppe graphs, the columns' performance was evaluated to determine the optimal flow rate and the speed-efficiency relationship, respectively. Based on the results, the best configurations for the WCOT column application to the LC system were defined: length-8 m; inner diameter-25 µm; mass of OV-210-2.5% m/v; and, injection volume-100 nL. Finally, the optimized WCOT column developed in this work was coupled with a commercially-packed trapping column in the nano liquid chromatography system (nanoLC). In this configuration, more significant results were obtained regarding separation resolution, with Rs = 5.9 achieved for the most retained pair of analytes (clomazone and metolachlor).


Assuntos
Espectrometria de Massas em Tandem , Cromatografia Líquida
18.
Reprod Domest Anim ; 58(9): 1244-1250, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37402154

RESUMO

Glass wool column filtration (GWCF) selects human, bull, boar, dog and buffalo spermatozoa, but reports in the horse are scarce. Single-layer colloid centrifugation with Androcoll-E™ is currently the standard procedure to select good-quality equine sperm. This study was designed to assess GWCF (50 and 75 mg columns; GWCF-50 and GWCF-75, respectively) efficacy to select good-quality sperm from fresh and frozen-thawed equine semen, and to compare its performance with Androcoll-E™ colloid centrifugation. Percentage total motile (TM), progressively motile (PM), morphologically normal (MN), osmotically competent (HOS+) and acrosome-intact/osmotically competent (AI/HOS+) sperm were determined. In studies done with fresh semen samples (n = 17), suspensions subjected to GWCF-50 showed an improvement (p < .05) in PM and HOS+ sperm after selection. With GWCF-75, an increase (p < .05) in PM, MN and HOS+ sperm was observed. Results with GWCF were comparable or better than with Androcoll-E™ selection. Sperm recovery was similar between procedures for all semen parameters. Total sperm count recovery was lower after GWCF-75 (GWCF-50 = 60.0; GWCF-75 = 51.0; Androcoll-E™ = 76.0 million sperm; median; p = .013), but results on total progressive sperm count were similar (GWCF-50 = 23.0; GWCF-75 = 27.0; Androcoll-E™ = 24.0 million sperm; median; p = .3850). Using frozen-thawed semen samples (n = 16), an improvement (p < .05) in TM, PM, NM, HOS+ and AI/HOS+ sperm was observed in GWCF-75 filtrates. Results were comparable to Androcoll-E™ centrifugation, except HOS+ that increased (p < .05) only after GWCF-75. Recovery was comparable for all parameters in frozen samples. GWCF is a simple and low-cost procedure that selects equine sperm with a quality comparable to colloid centrifugation with Androcoll-E™.


Assuntos
Bison , Preservação do Sêmen , Masculino , Animais , Cavalos , Suínos , Humanos , Cães , Sêmen , Criopreservação/veterinária , Criopreservação/métodos , Espermatozoides , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Coloides , Centrifugação/veterinária , Centrifugação/métodos , Búfalos , Motilidade dos Espermatozoides
20.
Molecules ; 28(4)2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36838639

RESUMO

Coffee is one of the world's most popular beverages, with the global coffee capsule market worth over USD 4 billion and growing. The incidence of coffee fraud is estimated to be up to one in five coffees being contaminated with cheaper blends of coffee. Given the worsening extent of climate change, coffee crop yields are harder to maintain, while demand is increasing. The 2021 Brazil frost delaying or destroying many coffee crops is an example. Hence, the incidence of coffee fraud is expected to increase, and as the market becomes more complex, there needs to be faster, easier, and more robust means of real-time coffee authentication. In this study, we propose the use of novel approaches to postcolumn derivatization (termed herein as in-column derivatization) to visualize the antioxidant profiles of coffee samples, to be later used as indicators for authentication purposes. We propose three simple mathematical similarity metrics for the real-time identification of unknown coffee samples from a sample library. Using the CUPRAC assay, and these metrics, we demonstrate the capabilities of the technique to identify unknown coffee samples from within our library of thirty.


Assuntos
Antioxidantes , Café , Cromatografia Líquida de Alta Pressão/métodos , Antioxidantes/análise , Bebidas , Brasil
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