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The goal of preparative chromatography is to isolate suitable amounts of compound(s) at the required purity in the most cost-effective way. This study analyses the power of High-performance thin-layer chromatography (HPTLC) guided preparative flash chromatography to separate and isolate bioactive compounds from an olive flower extract for their further characterisation via spectroscopy. The structure and purity of isolated bioactive compounds were assessed using Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy. Flash chromatography of the olive flower extract successfully isolated pure oleanolic and maslinic acids. Moreover, the flash chromatography of the extract allowed isolation and phytochemical analysis of the most lipophilic fraction of the extract, which was found to contain n-eicosane and n-(Z)-eicos-5-ene, that has not been isolated previously with preparative TLC.
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Flores , Espectroscopia de Ressonância Magnética , Olea , Extratos Vegetais , Flores/química , Cromatografia em Camada Fina/métodos , Olea/química , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Espectroscopia de Infravermelho com Transformada de Fourier , Triterpenos/análise , Triterpenos/isolamento & purificação , Triterpenos/química , Ácido Oleanólico/isolamento & purificação , Ácido Oleanólico/análise , Ácido Oleanólico/química , Ácido Oleanólico/análogos & derivados , Cromatografia Líquida de Alta Pressão/métodosRESUMO
This section aims to provide a concise and contemporary technical perspective and reference resource covering dry powder inhaler (DPI) formulations. While DPI products are currently the leading inhaled products in terms of sales value, a number of confounding perspectives are presented to illustrate why they are considered surprisingly, and often frustratingly, poorly understood on a fundamental scientific level, and most challenging to design from first principles. At the core of this issue is the immense complexity of fine cohesive powder systems. This review emphasizes that the difficulty of successful DPI product development should not be underestimated and is best achieved with a well-coordinated team who respect the challenges and who work in parallel on device and formulation and with an appreciation of the handling environment faced by the patient. The general different DPI formulation types, which have evolved to address the challenges of aerosolizing fine cohesive drug-containing particles to create consistent and effective DPI products, are described. This section reviews the range of particle engineering processes that may produce micron-sized drug-containing particles and their subsequent assembly as either carrier-based or carrier-free compositions. The creation of such formulations is then discussed in the context of the material, bulk, interfacial and ultimately drug-delivery properties that are considered to affect formulation performance. A brief conclusion then considers the future DPI product choices, notably the issue of technology versus affordability in the evolving inhaler market.
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Sistemas de Liberação de Medicamentos , Inaladores de Pó Seco , Humanos , Administração por Inalação , Preparações Farmacêuticas , Tamanho da Partícula , Pós , AerossóisRESUMO
BACKGROUND: Community health workers (CHWs) cover extensive areas observing the environmental conditions in which community members live. However, current CHW training modules do not have modules focusing specifically on environmental health. CHWs appear to lack knowledge of environmental health hazards, and little is known of their attitudes and practices regarding environmental health hazards. The purpose of this study was to determine the knowledge, attitudes, and practices of CHWs in relation to environmental health hazards in the Nelson Mandela Bay (NMB). METHODS: This study used a quantitative, cross-sectional research design. A sample of 110 respondents completed the questionnaire. The questionnaire was based on the literature, consisting of 36 items in four sections. Data analysis consisted of descriptive and inferential statistics. Reliability and validity were enhanced by utilizing a pre-test study. RESULTS: There were significant differences in attitudes (t = -2.308, df = 91.107, p = 0.023) and practices (t = -2.936, df = 62.491, p = 0.005). Those trained in environmental health had a significantly lower mean attitudes score (m = 3.2365, sd = 1.113) compared to those not trained in environmental health (m = 3.694, sd = 0.894). In addition, those trained in environmental health had a significantly lower mean practice score (practiced more frequently) (m = 1.231, sd = 0.327) compared to those not trained in environmental health (m = 1.4605, sd = 0.4162). Regarding training, 62% (n = 67) of CHWs felt they needed additional training in environmental health. CONCLUSION: Most of the CHWs had a moderate knowledge of environmental health hazards. Furthermore, most of the CHWs had a very positive or positive attitude towards environmental health hazards. However, there is a need for CHWs to receive very specific training in environmental health. In addition, the scope of work of CHWs, as well as their role in relation to environmental health, needs to be further explored.
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Agentes Comunitários de Saúde , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Agentes Comunitários de Saúde/psicologia , Estudos Transversais , Baías , Reprodutibilidade dos TestesRESUMO
BACKGROUND AND OBJECTIVE: The movement of the respiratory walls has a significant impact on airflow through the respiratory tract. The majority of computational fluid dynamics (CFD) studies assume a static geometry which may not provide a realistic flow field. Furthermore, many studies use Reynolds Averaged Navier-Stokes (RANS) turbulence models that do not resolve turbulence structure. Combining the application of advanced scale-resolving turbulence models with moving respiratory walls using CFD will provide detailed insights into respiratory flow structures. METHODS: This study simulated a complete breathing cycle involving inhalation and exhalation in a nasal cavity to trachea geometry that incorporated moving glottis walls. A second breathing cycle was simulated with static glottis walls for comparison. A recently developed hybrid RANS-LES turbulence model, the Stress-Blended Eddy Simulation (SBES), was incorporated to resolve turbulent flow structures in fine detail for both transient simulations. Transient results were compared with steady-state RANS simulations for the same respiratory geometry. RESULTS: Glottis motion caused substantial effects on flow structure through the complete breathing cycle. Significant flow structure and velocity variations were observed due to glottal motion, primarily in the larynx and trachea. Resolved turbulence structures using SBES showed an intense mixing section in the glottis region during inhalation and in the nasopharynx during expiration, which was not present in the RANS simulations. CONCLUSION: Transient simulations of a realistic breathing cycle uncovered flow structures absent in simulations with a constant flow rate. Furthermore, the incorporation of glottis motion impacted airflow characteristics that suggest rigid respiratory walls do not accurately describe respiratory flow. Future research in respiratory airflow should be conducted using transient scale-resolving models in conjunction with moving respiratory walls to capture flow structures in detail.
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Iron-based materials (IBMs) have shown promise as adsorbents due to their unique physicochemical properties. This review provides an overview of the different types of IBMs, their synthesis methods, and their properties. Results found in the adsorption of emerging contaminants to a wide range of IBMs are discussed. The IBMs used were evaluated in terms of their maximum uptake capacity, with special consideration given to environmental conditions such as contact time, solution pH, initial pollutant concentration, etc. The adsorption mechanisms of pollutants are discussed taking into account the results of kinetic, isotherm, thermodynamic studies, surface complexation modelling (SCM), and available spectroscopic data. A current overview of molecular modeling and simulation studies related to density functional theory (DFT), surface response methodology (RSM), and artificial neural network (ANN) is presented. In addition, the reusability and suitability of IBMs in real wastewater treatment is shown. The review concludes with the strengths and weaknesses of current research and suggests ideas for future research that will improve our ability to remove contaminants from real wastewater streams.
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Poluentes Ambientais , Poluentes Químicos da Água , Ferro , Adsorção , Termodinâmica , CinéticaRESUMO
Olive trees are one of the most widely cultivated fruit trees in the world. The chemical compositions and biological activities of olive tree fruit and leaves have been extensively researched for their nutritional and health-promoting properties. In contrast, limited data have been reported on olive flowers. The present study aimed to analyse bioactive compounds in olive flower extracts and the effect of fermentation-assisted extraction on phenolic content and antioxidant activity. High-performance thin-layer chromatography (HPTLC) hyphenated with the bioassay-guided detection and spectroscopic identification of bioactive compounds was used for the analysis. Enzymatic and bacterial in situ bioassays were used to detect COX-1 enzyme inhibition and antibacterial activity. Multiple zones of antibacterial activity and one zone of COX-1 inhibition were detected in both, non-fermented and fermented, extracts. A newly developed HPTLC-based experimental protocol was used to measure the high-maximal inhibitory concentrations (IC50) for the assessment of the relative potency of the extracts in inhibiting COX-1 enzyme and antibacterial activity. Strong antibacterial activities detected in zones 4 and 7 were significantly higher in comparison to ampicillin, as confirmed by low IC50 values (IC50 = 57-58 µg in zone 4 and IC50 = 157-167 µg in zone 7) compared to the ampicillin IC50 value (IC50 = 495 µg). The COX-1 inhibition by the extract (IC50 = 76-98 µg) was also strong compared to that of salicylic acid (IC50 = 557 µg). By comparing the locations of the bands to coeluted standards, compounds from detected bioactive bands were tentatively identified. The eluates from bioactive HPTLC zones were further analysed by FTIR NMR, and LC-MS spectroscopy. Multiple zones of antibacterial activity were associated with the presence of triterpenoid acids, while COX-1 inhibition was related to the presence of long-chain fatty acids.
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Olea , Olea/química , Cromatografia em Camada Fina/métodos , Árvores , Extratos Vegetais/química , Flores/química , Antibacterianos/farmacologia , Antibacterianos/análise , Antioxidantes/farmacologia , Espectroscopia de Ressonância Magnética , Ampicilina/análise , Bioensaio/métodosRESUMO
Natural products and their analogues have contributed significantly to treatment options, especially for anti-inflammatory and infectious diseases. Thus, the primary objective of this work was to compare the bioactivity profiles of selected medicinal plants that are historically used in folk medicine to treat inflammation and infections in the body. Chemical HPTLC fingerprinting was used to assess antioxidant, phenolic and flavonoid content, while bioassay-guided HPTLC was used to detect compounds with the highest antibacterial and anti-inflammatory activities. The results of this study showed that green tea leaf, walnut leaf, St. John's wort herb, wild thyme herb, European goldenrod herb, chamomile flower, and immortelle flower extracts were strong radical scavengers. Green tea and nettle extracts were the most active extracts against E. coli, while calendula flower extract showed significant potency against S. aureus. Furthermore, green tea, greater celandine, and fumitory extracts exhibited pronounced potential in suppressing COX-1 activity. The bioactive compounds from the green tea extract, as the most bioactive, were isolated by preparative thin-layer chromatography and characterized with their FTIR spectra. Although earlier studies have related green tea's anti-inflammatory properties to the presence of catechins, particularly epigallocatechin-3-gallate, the FTIR spectrum of the compound from the most intense bioactive zone showed the strongest anti-inflammatory activity can be attributed to amino acids and heterocyclic compounds. As expected, antibacterial activity in extracts was related to fatty acids and monoglycerides.
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Produtos Biológicos , Plantas Medicinais , Antioxidantes/farmacologia , Antioxidantes/química , Plantas Medicinais/química , Cromatografia em Camada Fina/métodos , Staphylococcus aureus , Escherichia coli , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Antibacterianos/farmacologia , Antibacterianos/química , Anti-Inflamatórios/farmacologia , Bioensaio , CháRESUMO
Solid-phase microextraction (SPME) is a sample preparation technique which utilizes small amounts of an extraction phase for the extraction of target analytes from investigated sample matrices. Its simplicity of use, relatively short sample processing time, and fiber reusability have made SPME an attractive choice for many analytical applications. SPME has been widely applied to the sampling and analysis of environmental, food, aromatic, metallic, forensic, and pharmaceutical samples. Solid phase microextraction is used in horticultural crops, for example, to determine water and soil contaminants (pesticides, alcohols, phenols, amines, herbicides, etc.). SPME is also used in the food industry to separate biologically active substances in food products for various purposes, for example, disease prevention, determining the smell of food products, and analyzing tastes. SPME has been applied to forensic analysis to determine the alcohol concentration in blood and that of sugar in urine. This method has also been widely used in pharmaceutical analysis. It is a solvent-free sample preparation technique that integrates sampling, isolation, and concentration. This review focuses on recent work on the use of SPME techniques in the analysis of food and horticultural crops.
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Produtos Agrícolas , Microextração em Fase Sólida , Microextração em Fase Sólida/métodos , Solventes , Etanol , Preparações FarmacêuticasRESUMO
This study compares different solvent systems with the use of spontaneous fermentation on the phytochemical composition of leaf extracts from a locally grown white variety of common fig (Ficus carica Linn.). The aim was to detect and identify bioactive compounds that are responsible for acetylcholinesterase (AChE), α-amylase and cyclooxygenase-1 (COX-1) enzyme inhibition, and compounds that exhibit antimicrobial activity. Bioactive zones in chromatograms were detected by combining High-performance thin-layer chromatography (HPTLC) with enzymatic and biological assays. A new experimental protocol for measuring the relative half-maximum inhibitory concentration (IC50) was designed to evaluate the potency of the extracts compared to the potency of known inhibitors. Although the IC50 of the fig leaf extract for α-amylase and AChE inhibition were significantly higher when compared to IC50 for acarbose and donepezil, the COX-1 inhibition by the extract (IC50 = 627 µg) was comparable to that of salicylic acid (IC50 = 557 µg), and antimicrobial activity of the extract (IC50 = 375-511 µg) was similar to ampicillin (IC50 = 495 µg). Four chromatographic zones exhibited bioactivity. Compounds from detected bioactive bands were provisionally identified by comparing the band positions to coeluted standards, and by Fourier transform infrared (FTIR) spectra from eluted zones. Flash chromatography was used to separate selected extract into fractions and isolate fractions that are rich in bioactive compounds for further characterisation with nuclear magnetic resonance (NMR) spectroscopy and liquid chromatography-mass spectrometry (LC-MS) analysis. The main constituents identified were umbelliferon (zone 1), furocoumarins psoralen and bergapten (zone 2), different fatty acids (zone 3 and 4), and pentacyclic triterpenoids (calotropenyl acetate or lupeol) and stigmasterol (zone 4).
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Anti-Infecciosos , Ficus , Cromatografia em Camada Fina , Ficus/química , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Acetilcolinesterase , alfa-Amilases , Triterpenos Pentacíclicos , Anti-Infecciosos/farmacologiaRESUMO
BACKGROUND: There have been 26 epidemic thunderstorm asthma (ETSA) events worldwide, with Melbourne at the epicentre of ETSA with 7 recorded events, and in 2016 experienced the deadliest ETSA event ever recorded. Health services and emergency departments were overwhelmed with thousands requiring medical care for acute asthma and 10 people died. OBJECTIVES: This multidisciplinary study was conducted across various health and science departments with the aim of improving our collective understanding of the mechanism behind ETSA. DESIGN: This study involved time-resolved analysis of atmospheric sampling of the air for pollen and fungal spores, and intact and ruptured pollen compared with different weather parameters, pollution levels and clinical asthma presentations. METHODS: Time-resolved pollen and fungal spore data collected by Deakin AirWATCH Burwood, underwent 3-h analysis, to better reflect the 'before', 'during' and 'after' ETSA time points, on the days leading up to and following the Melbourne 2016 event. Linear correlations were conducted with atmospheric pollution data provided by the Environment Protection Authority (EPA) of Victoria, weather data sourced from Bureau of Meteorology (BOM) and clinical asthma presentation data from the Victorian Agency for Health Information (VAHI) of Department of Health. RESULTS: Counts of ruptured grass pollen grains increased 250% when the thunderstorm outflow reached Burwood. Increased PM10, high relative humidity, decreased temperature and low ozone concentrations observed in the storm outflow were correlated with increased levels of ruptured grass pollen. In particular, high ozone levels observed 6 h prior to this ETSA event may be a critical early indicator of impending ETSA event, since high ozone levels have been linked to increasing pollen allergen content and reducing pollen integrity, which may in turn contribute to enhanced pollen rupture. CONCLUSION: The findings presented in this article highlight the importance of including ruptured pollen and time-resolved analysis to forecast ETSA events and thus save lives.
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Asma , Ozônio , Humanos , Alérgenos , Pólen , Asma/epidemiologia , Asma/etiologia , Tempo (Meteorologia) , Ozônio/efeitos adversosRESUMO
PURPOSE: Up to date, there has been a lack of software infrastructure to connect 3D Slicer to any augmented reality (AR) device. This work describes a novel connection approach using Microsoft HoloLens 2 and OpenIGTLink, with a demonstration in pedicle screw placement planning. METHODS: We developed an AR application in Unity that is wirelessly rendered onto Microsoft HoloLens 2 using Holographic Remoting. Simultaneously, Unity connects to 3D Slicer using the OpenIGTLink communication protocol. Geometrical transform and image messages are transferred between both platforms in real time. Through the AR glasses, a user visualizes a patient's computed tomography overlaid onto virtual 3D models showing anatomical structures. We technically evaluated the system by measuring message transference latency between the platforms. Its functionality was assessed in pedicle screw placement planning. Six volunteers planned pedicle screws' position and orientation with the AR system and on a 2D desktop planner. We compared the placement accuracy of each screw with both methods. Finally, we administered a questionnaire to all participants to assess their experience with the AR system. RESULTS: The latency in message exchange is sufficiently low to enable real-time communication between the platforms. The AR method was non-inferior to the 2D desktop planner, with a mean error of 2.1 ± 1.4 mm. Moreover, 98% of the screw placements performed with the AR system were successful, according to the Gertzbein-Robbins scale. The average questionnaire outcomes were 4.5/5. CONCLUSIONS: Real-time communication between Microsoft HoloLens 2 and 3D Slicer is feasible and supports accurate planning for pedicle screw placement.
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Particulate amorphous solid dispersions (ASDs) have been recognised for their potential to enhance the performance of various solid dose forms, especially oral bioavailability and macromolecule stability. However, the inherent nature of spray-dried ASDs leads to their surface cohesion/adhesion, including hygroscopicity, which hinders their bulk flow and affects their utility and viability in terms of powder production, processing, and function. This study explores the effectiveness of L-leucine (L-leu) coprocessing in modifying the particle surface of ASD-forming materials. Various contrasting prototype coprocessed ASD excipients from both the food and pharmaceutical industries were examined for their effective coformulation with L-leu. The model/prototype materials included maltodextrin, polyvinylpyrrolidone (PVP K10 and K90), trehalose, gum arabic, and hydroxypropyl methylcellulose (HPMC E5LV and K100M). The spray-drying conditions were set such that the particle size difference was minimised, so that it did not play a substantial role in influencing powder cohesion. Scanning electron microscopy was used to evaluate the morphology of each formulation. A combination of previously reported morphological progression typical of L-leu surface modification and previously unreported physical characteristics was observed. The bulk characteristics of these powders were assessed using a powder rheometer to evaluate their flowability under confined and unconfined stresses, flow rate sensitivities, and compactability. The data showed a general improvement in maltodextrin, PVP K10, trehalose and gum arabic flowability measures as L-leu concentrations increased. In contrast, PVP K90 and HPMC formulations experienced unique challenges that provided insight into the mechanistic behaviour of L-leu. Therefore, this study recommends further investigations into the interplay between L-leu and the physico-chemical properties of coformulated excipients in future amorphous powder design. This also revealed the need to enhance bulk characterisation tools to unpack the multifactorial impact of L-leu surface modification.
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OBJECTIVE: This article examines the ethical principles underlying the Declaration of Helsinki as an internationally agreed justificatory framework for human medical research. The aim of the analysis is to consider the potential usefulness of these principles for defining an internationally agreed ethical 'best practice' in clinical veterinary research (CVR). It is suggested that the specific ethical responsibilities of the clinician to protect the interests of their patient when conducting medical research may be translated into the veterinary setting. Through exploring risk and harm, unproven interventions, vulnerability and informed consent, the article identifies the ethical risks of CVR. It is shown that veterinary regulators in the UK and the European Union have addressed these concerns to varying degrees; however, disagreements over the appropriateness of specific CVR practices are identified. A commitment to collaborative exploration of the benefits and challenges of implementing a Declaration of Helsinki for Animals is proposed.
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Declaração de Helsinki , Consentimento Livre e Esclarecido , Animais , HumanosRESUMO
BACKGROUND: The utilisation of massed therapy for treating posttraumatic stress disorder (PTSD) is gaining strength, especially prolonged exposure. However, it is unknown whether massed prolonged exposure (MPE) is non-inferior to standard prolonged exposure (SPE) protocols in the long term. The current study aimed to assess whether MPE was non-inferior to SPE at 12 months post-treatment, and to ascertain changes in secondary measure outcomes. METHODS: A multi-site non-inferiority randomised controlled trial (RCT) compared SPE with MPE in 12 clinics. The primary outcome was PTSD symptom severity (CAPS-5) at 12 months post-treatment commencement. Secondary outcome measures included symptoms of depression, anxiety, anger, disability, and quality of life at 12 weeks and 12 months post-treatment commencement. Outcome assessors were blinded to treatment allocation. The intention-to-treat sample included 138 Australian military members and veterans and data were analysed for 134 participants (SPE = 71, MPE = 63). RESULTS: Reductions in PTSD severity were maintained at 12 months and MPE remained non-inferior to SPE. Both treatment groups experienced a reduction in depression, anxiety, anger, and improvements in quality of life at 12 weeks and 12 months post-treatment commencement. Treatment effects for self-reported disability in the SPE group at 12 weeks were not maintained, with neither group registering significant effects at 12 months. CONCLUSIONS: The emergence of massed protocols for PTSD is an important advancement. The current study provides RCT evidence for the longevity of MPE treatment gains at 12 months post-treatment commencement and demonstrated non-inferiority to SPE. Promisingly, both treatments also significantly reduced the severity of comorbid symptoms commonly occurring alongside PTSD.
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Terapia Implosiva , Militares , Transtornos de Estresse Pós-Traumáticos , Veteranos , Humanos , Austrália , Seguimentos , Terapia Implosiva/métodos , Transtornos de Estresse Pós-Traumáticos/terapia , Resultado do TratamentoRESUMO
This paper presents and illustrates, with a working example, a hypothesis for the assessment of ongoing severity before and during an experiment that will enable humane endpoints and intervention points to be applied accurately and reproducibly, as well as helping to implement any national legal severity limits in subacute and chronic animal experiments, e.g., as specified by the competent authority. The underlying assumption of the model framework is that the degree of deviation from normality of specified measurable biological criteria will reflect the level of pain, suffering, distress and lasting harm incurred by or during an experiment. The choice of criteria will normally reflect the impact on an animal and have to be chosen by scientists and those caring for the animals. They will usually include measurements of good health such as temperature, body weight, body condition and behaviour, which vary according to the species, husbandry and experimental protocols and, in some species, unusual parameters such as time of the year (e.g., migrating birds). In animal research legislation, endpoints or severity limits may be specified so that individual animals do not suffer unnecessarily or endure severe pain and distress that is long-lasting (Directive 2010/63/EU, Art.15.2). In addition, the overall severity is estimated and classified as part of the harm: benefit licence assessment. I present a mathematical model to analyse the measurement data to determine the degree of harm (or severity) incurred. The results can be used to initiate alleviative treatment if required or if permitted during the course of an experiment. In addition, any animal determined to have breached the severity classification of a procedure can be humanely killed, treated or withdrawn from the experiment. The system incorporates the flexibility to be used in most animal research work by being tailored to the research, the procedures carried out and the species under investigation. The criteria used to score severity can also be used as additional scientific outcome criteria and for an analysis of the scientific integrity of the project.
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Extracts of two Salvia species, Salvia apiana (white sage) and Salvia officinalis (common sage) were screened for phytoconstituents with the ability to act as antidiabetic, cognitive enhancing, or antimicrobial agents, by hyphenation of high-performance thin-layer chromatography with enzymatic and microbial effect directed assays. Two bioactive zones with α-amylase inhibition (zone 1 and zone 2), 3 zones for acetylcholinesterase inhibition (zones 3, 4 and 5), and two zones for antimicrobial activity (zones 4 and 5) were detected. The compounds from the five bioactive zones were initially identified by coelution with standards and comparing the RF values of standards to the bioautograms. Identity was confirmed with ATR-FTIR spectra of the isolated compounds from the bioactive zones. A significantly higher α-amylase and acetylcholinesterase inhibition of S. apiana leaf extract was associated with a higher flavonoid and diterpenoid content. Fermented S. officinalis extract exhibited a significantly higher ability to inhibit α-amylase compared to other non-fermented extracts from this species, due to increased extraction of flavonoids. The ATR-FTIR spectra of 2 zones with α-amylase inhibition, indicated that flavonoids and phenolic acids were responsible for α-amylase inhibition. Multiple zones of acetylcholinesterase inhibition were related to the presence of phenolic abietane diterpenoids and triterpenoid acids. The presence of abietane diterpenoids and triterpenoid acids was also found responsible for the mild antimicrobial activity. Flash chromatography was used to isolate sufficient amounts of bioactive compounds for further characterisation via NMR and MS spectroscopy. Five compounds were assigned to the zones where bioactivity was observed: cirsimaritin (zone 1), a caffeic acid polymer (zone 2), 16-hydroxyrosmanol (zone 3), 16-hydroxycarnosic acid (zone 4), oleanolic and ursolic acids (zone 5).
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Anti-Infecciosos , Salvia , Triterpenos , Salvia/química , Acetilcolinesterase , Cromatografia em Camada Fina/métodos , Abietanos , Anti-Infecciosos/farmacologia , Flavonoides , alfa-Amilases , Extratos Vegetais/química , Antioxidantes/farmacologiaRESUMO
In response to COVID-19, schools across the United States closed in early 2020; many did not fully reopen until late 2021. Although regular testing of asymptomatic students, teachers, and staff can reduce transmission risks, few school systems consistently used proactive testing to safeguard return to classrooms. Socioeconomically diverse public school districts might vary testing levels across campuses to ensure fair, effective use of limited resources. We describe a test allocation approach to reduce overall infections and disparities across school districts. Using a model of SARS-CoV-2 transmission in schools fit to data from a large metropolitan school district in Texas, we reduced incidence between the highest and lowest risk schools from a 5.6-fold difference under proportional test allocation to 1.8-fold difference under our optimized test allocation. This approach provides a roadmap to help school districts deploy proactive testing and mitigate risks of future SARS-CoV-2 variants and other pathogen threats.