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PURPOSE: To explore if mean concentric velocity (MCV) of the last repetition before set failure differs between free-weight back squat protocols with greater emphasis on metabolic accumulation vs. mechanical loading. The between-set and between-day reliability of terminal MCV obtained with these different loading schemes was also determined. METHODS: Fifteen healthy male participants (18-30 years) were included. They all were required to exhibit a relative strength ≥ 1.5 times their body mass. MCVs were obtained at one-repetition maximum (1RM) and with two submaximal protocols (metabolic emphasis: three sets of 40%1RM with blood-flow restriction vs. mechanical emphasis: three sets 80%1RM without blood-flow restriction). Participants were instructed to reach maximal intended concentric velocity in each repetition up to failure. RESULTS: Set failure was achieved at a faster MCV with the metabolic protocol (p < 0.05). The reliability of MCV at failure reached higher values for the metabolic loading scheme. However, while the MCV achieved at failure during the metabolic protocol was systematically higher than the MCV at 1RM (p < 0.05), this was not entirely the case for the mechanical protocol (similar to 1RM MCV during the last sets in both testing days). Finally, the absolute error derived from estimating the MCV at 1RM based on the MCV obtained at set failure with the mechanical protocol was considerably high (≥ 0.05 m/s). CONCLUSION: This study indicates that MCV obtained at set failure is dependent on the specificity of the physiological demands of exercise. Thus, MCVs obtained at failure with submaximal loads should not be used to estimate 1RM MCV.
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This study aimed to evaluate the effect of the biofloc technology (BFT) system and the replacement of fish meal with Spirulina biomass on productive performance, intestinal histomorphometry, plasma biochemistry, and oxidative stress of Nile tilapia juveniles (Oreochromis niloticus) fed suboptimal levels of protein. Two factors were evaluated: production systems (clear water × BFT) and replacement of fish meal with Spirulina (0, 33, 66 e 100%). The design was in a 2 × 4 randomized factorial scheme with four replications, and the fish were evaluated for 48 days. Four isoproteic (28% crude protein) diets were formulated with gross energy values close to 4300 kcal kg-1. Nile tilapia juveniles (0.23 ± 0.01 g) were distributed in 16 circular tanks (70 L) at seven fish/tank. The diets were formulated with protein levels approximately 20% below that required for the species and life stage. No interaction was observed between the factors evaluated (production systems × Spirulina inclusion). Rearing the fish in the BFT system avoided the adverse effects of diets with suboptimal protein levels on performance, intestinal histomorphometry, and protein metabolism. Lower values lower lipid peroxidation and higher antioxidant capacity were observed in fish reared in the BFT system, showing evidence of improvements in antioxidant responses and lower levels of physiological oxidative stress. Spirulina completely replaced fish meal in the diets of Nile tilapia juveniles without adverse effects on intestinal morphometry, protein metabolism, and antioxidant response. Replacing 66% of fish meal with Spirulina improved the productive performance, regardless of the rearing system.
Subject(s)
Animal Feed , Cichlids , Diet , Intestines , Spirulina , Animals , Cichlids/metabolism , Cichlids/growth & development , Animal Feed/analysis , Intestines/drug effects , Diet/veterinary , Dietary Proteins/administration & dosage , Oxidative Stress/drug effects , Animal Nutritional Physiological Phenomena , Aquaculture/methodsABSTRACT
Introduction: Rare disorders that are genetically and clinically heterogeneous, such as mitochondrial diseases (MDs), have a challenging diagnosis. Nuclear genes codify most proteins involved in mitochondrial biogenesis, despite all mitochondria having their own DNA. The development of next-generation sequencing (NGS) technologies has revolutionized the understanding of many genes involved in the pathogenesis of MDs. In this new genetic era, using the NGS approach, we aimed to identify the genetic etiology for a suspected MD in a cohort of 450 Portuguese patients. Methods: We examined 450 patients using a combined NGS strategy, starting with the analysis of a targeted mitochondrial panel of 213 nuclear genes, and then proceeding to analyze the whole mitochondrial DNA. Results and Discussion: In this study, we identified disease-related variants in 134 (30%) analyzed patients, 88 with nuclear DNA (nDNA) and 46 with mitochondrial DNA (mtDNA) variants, most of them being pediatric patients (66%), of which 77% were identified in nDNA and 23% in mtDNA. The molecular analysis of this cohort revealed 72 already described pathogenic and 20 novel, probably pathogenic, variants, as well as 62 variants of unknown significance. For this cohort of patients with suspected MDs, the use of a customized gene panel provided a molecular diagnosis in a timely and cost-effective manner. Patients who cannot be diagnosed after this initial approach will be further selected for whole-exome sequencing. Conclusion: As a national laboratory for the study and research of MDs, we demonstrated the power of NGS to achieve a molecular etiology, expanding the mutational spectrum and proposing accurate genetic counseling in this group of heterogeneous diseases without therapeutic options.
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Multi-signal calibrations have been recently exploited in molecular spectrochemical analysis alternatively to traditional calibration methods, improving analytical frequency and accuracy. The application of these strategies is simple and minimizes efficiently matrix effects by analyzing two calibration solutions comprising sample plus standard (S1), and sample plus blank (S2). The plot of the signals obtained with S1 and S2 at multiple settings (e.g. different wavelengths) yield a slope that can be related to the analyte concentration in the sample. Similarly, transient signals could also be related to the analyte concentration exploiting a similar strategy. Thus, in this work, two multi-signal approaches developed in flow-based systems are proposed, based on the responses at multiple wavelengths (online multi-energy calibration, OMEC), and on the dispersion profile of the samples, herein denominated multi-dispersion calibration (MDC). The calibrations were carried out with sample solutions after 2-fold dilution with a standard solution and with water. The feasibility of OMEC and MDC were demonstrated using KMnO4 solutions (without chemical reactions) under continuous and pulsed flow regimes. The applicability of this strategy was also demonstrated by the spectrophotometric determination of urea in milk and pet potty spray in a multi-pumping flow system, based on the color change of bromothymol blue after catalyzed hydrolysis by urease from jack beans (Canavalia ensiformis). MDC and OMEC were compared with external calibrations (EC) and classical standard addition. The limits of detection for urea were estimated at 13 mg L-1, 16 mg L-1, and 10 mg L-1 using MDC, MEC and EC, respectively. Recoveries from 93 to 101%, and the agreement of sample analyzes with the reference procedure demonstrated the good accuracy achieved by the proposed methods. Therefore, it was demonstrated the feasibility of MDC and OMEC for analytical purposes in a simple and efficient way with the advantages of flow-based manifolds.
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The description of neuronal activity has been of great importance in neuroscience. In this field, mathematical models are useful to describe the electrophysical behavior of neurons. One successful model used for this purpose is the Adaptive Exponential Integrate-and-Fire (Adex), which is composed of two ordinary differential equations. Usually, this model is considered in the standard formulation, i.e., with integer order derivatives. In this work, we propose and study the fractal extension of Adex model, which in simple terms corresponds to replacing the integer derivative by non-integer. As non-integer operators, we choose the fractal derivatives. We explore the effects of equal and different orders of fractal derivatives in the firing patterns and mean frequency of the neuron described by the Adex model. Previous results suggest that fractal derivatives can provide a more realistic representation due to the fact that the standard operators are generalized. Our findings show that the fractal order influences the inter-spike intervals and changes the mean firing frequency. In addition, the firing patterns depend not only on the neuronal parameters but also on the order of respective fractal operators. As our main conclusion, the fractal order below the unit value increases the influence of the adaptation mechanism in the spike firing patterns.
Subject(s)
Fractals , Models, Neurological , Action Potentials/physiology , Neurons/physiologyABSTRACT
Hypoxia plays a significant role in the development of various cerebral diseases, many of which are associated with the potential risk of recurrence due to mitochondrial damage. Conventional drug treatments are not always effective for hypoxia-related brain diseases, necessitating the exploration of alternative compounds. In this study, we investigated the potential of diphenyl diselenide [(PhSe)2] to ameliorate locomotor impairments and mitigate brain mitochondrial dysfunction in zebrafish subjected to hypoxia. Additionally, we explored whether these improvements could confer resistance to recurrent hypoxia. Through a screening process, an appropriate dose of (PhSe)2 was determined, and animals exposed to hypoxia received a single intraperitoneal injection of 100 mg/kg of the compound or vehicle. After 1 h from the injection, evaluations were conducted on locomotor deficits, (PhSe)2 content, mitochondrial electron transport system, and mitochondrial viability in the brain. The animals were subsequently exposed to recurrent hypoxia to assess the latency time to hypoxia symptoms. The findings revealed that (PhSe)2 effectively crossed the blood-brain barrier, attenuated locomotor deficits induced by hypoxia, and improved brain mitochondrial respiration by modulating complex III. Furthermore, it enhanced mitochondrial viability in the telencephalon, contributing to greater resistance to recurrent hypoxia. These results demonstrate the beneficial effects of (PhSe)2 on both hypoxia and recurrent hypoxia, with cerebral mitochondria being a critical target of its action. Considering the involvement of brain hypoxia in numerous pathologies, (PhSe)2 should be further tested to determine its effectiveness as a potential treatment for hypoxia-related brain diseases.
Subject(s)
Brain Diseases , Organoselenium Compounds , Animals , Zebrafish , Mitochondria , Benzene Derivatives/pharmacology , Benzene Derivatives/therapeutic use , Organoselenium Compounds/pharmacology , Organoselenium Compounds/therapeutic use , Hypoxia/drug therapyABSTRACT
Value-based payment (VBP) models are designed and implemented to improve outcomes at the same or lower costs. Their adoption requires significant changes in the way healthcare organisations and insurance companies operate. Usually, before VBP models are widely implemented, pilot projects are conducted. Payers need to have a comprehensive set of requirements to enter into agreements with healthcare organisations on these pilots. In this short communication, we outline key elements reported in the literature, inside and outside healthcare organisations, as well as within the contract, that need to be considered in a pilot VBP model. Discussions regarding the introduction of VBP models may be strongly affected by external contextual factors, including regulations, which are outside the control of healthcare organisations. It requires collaboration between organisations, including primary care organisations and hospitals, while within organisations, it frequently requires creating multidisciplinary teams. The focus is on ensuring transparency, collaboration, and shared decision-making, realised by standardising communication processes and regular meetings. Additionally, effective leadership is needed, in which leaders set goals and priorities, as well as manage change. In the contractual agreements between payers and healthcare organisations, outcome measures need to be adequately defined and measured, including individual patient outcomes and composite scores, as well as absolute and relative performance measures. These measures should be tested periodically and catered to the organisations adopting the model. Also, incentives should have adequate size and frequency and be intrinsic and extrinsic. The consideration of these sets of key elements by the payers is essential when implementing VBP model pilot projects.
Subject(s)
Health Facilities , Hospitals , Humans , LeadershipABSTRACT
BACKGROUND: HIV treatment has been available in Mozambique since 2004, but coverage of, and retention in, antiretroviral therapy (ART) remain suboptimal. Therefore, to increase health system efficiency and reduce HIV-associated mortality, in November, 2018, the Ministry of Health launched national guidelines on implementing eight differentiated service delivery models (DSDMs) for HIV treatment. We assessed the effect of this implementation on retention in ART 12 months after initiation, and explored the associated effects of COVID-19. METHODS: In this uncontrolled interrupted time-series analysis, data were extracted from the Mozambique ART database, which contains data on individuals in ART care from 1455 health facilities providing ART in Mozambique. We included individual-level data from facilities that were providing ART at the beginning of the study period (Jan 1, 2016) and at the start of DSDM implementation (Dec 1, 2018). We compared the proportion of individuals retained in ART 12 months after initiation between the periods before (Jan 1, 2017, to Nov 30, 2018) and after (Dec 1, 2019, to June 30, 2021) implementation of the DSDMs, overall and stratified by sex and age. We applied a generalised estimating equation model with a working independence correlation and cluster-robust standard errors to account for clustering at the facility level. In a secondary analysis, we assessed the effect of COVID-19 response measures during the post-intervention period on ART retention. FINDINGS: The study included 613 facilities and 1â131â118 individuals who started ART during the inclusion period up to June 30, 2020, of whom 79â178 (7·0%) were children (age ≤14 years), 226â224 (20·0%) were adolescents and young adults (age 15-24 years), and 825â716 (73·0%) were adults (age ≥25 years). 731â623 (64·7%) were female and 399â495 (35·3%) were male. Introduction of the DSDMs was associated with an estimated increase of 24·5 percentage points (95% CI 21·1 to 28·0) in 12-month ART retention by the end of the study period, compared with the counterfactual scenario without DSDM implementation. By age, the smallest effect was estimated in children (6·1 percentage points, 1·3 to 10·9) and the largest effect in adolescents and young adults (28·8 percentage points, 24·2 to 33·4); by sex, a larger effect was estimated in males (29·7 percentage points, 25·6 to 33·7). Our analysis showed that COVID-19 had an overall negative effect on 12-month retention in ART compared with a counterfactual scenario based on the post-intervention period without COVID-19 (-10·0 percentage points, -18·2 to -1·8). INTERPRETATION: The implementation of eight DSDMs for HIV treatment had a positive impact on 12-month retention in ART. COVID-19 negatively influenced this outcome. FUNDING: None. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.
Subject(s)
Anti-HIV Agents , COVID-19 , HIV Infections , Adolescent , Young Adult , Child , Humans , Male , Female , Adult , Mozambique/epidemiology , HIV Infections/drug therapy , HIV Infections/epidemiology , Interrupted Time Series Analysis , Cluster Analysis , COVID-19/epidemiology , Anti-HIV Agents/therapeutic useABSTRACT
Healthy brains display a wide range of firing patterns, from synchronized oscillations during slow-wave sleep to desynchronized firing during movement. These physiological activities coexist with periods of pathological hyperactivity in the epileptic brain, where neurons can fire in synchronized bursts. Most cortical neurons are pyramidal regular spiking (RS) cells with frequency adaptation and do not exhibit bursts in current-clamp experiments (in vitro). In this work, we investigate the transition mechanism of spike-to-burst patterns due to slow potassium and calcium currents, considering a conductance-based model of a cortical RS cell. The joint influence of potassium and calcium ion channels on high synchronous patterns is investigated for different synaptic couplings (gsyn) and external current inputs (I). Our results suggest that slow potassium currents play an important role in the emergence of high-synchronous activities, as well as in the spike-to-burst firing pattern transitions. This transition is related to the bistable dynamics of the neuronal network, where physiological asynchronous states coexist with pathological burst synchronization. The hysteresis curve of the coefficient of variation of the inter-spike interval demonstrates that a burst can be initiated by firing states with neuronal synchronization. Furthermore, we notice that high-threshold (IL) and low-threshold (IT) ion channels play a role in increasing and decreasing the parameter conditions (gsyn and I) in which bistable dynamics occur, respectively. For high values of IL conductance, a synchronous burst appears when neurons are weakly coupled and receive more external input. On the other hand, when the conductance IT increases, higher coupling and lower I are necessary to produce burst synchronization. In light of our results, we suggest that channel subtype-specific pharmacological interactions can be useful to induce transitions from pathological high bursting states to healthy states.
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This work studies the SIS model extended by fractional and fractal derivatives. We obtain explicit solutions for the standard and fractal formulations; for the fractional case, we study numerical solutions. As a real data example, we consider the Brazilian syphilis data from 2011 to 2021. We fit the data by considering the three variations of the model. Our fit suggests a recovery period of 11.6 days and a reproduction ratio (R0) equal to 6.5. By calculating the correlation coefficient (r) between the real data and the theoretical points, our results suggest that the fractal model presents a higher r compared to the standard or fractional case. The fractal formulation is improved when two different fractal orders with distinguishing weights are considered. This modification in the model provides a better description of the data and improves the correlation coefficient.
Subject(s)
Epidemiological Models , Syphilis , Humans , Fractals , BrazilABSTRACT
Value-based healthcare aims to improve efficiency and value for patients. Value-based payment models are a form of provider reimbursement to achieve this. Studies on these models have found positive results, but may be biased by unintended consequences, such as risk selection. Risk selection is a multi-dimensional phenomenon that occurs at the patient, hospital, and system level, and is a source of inefficiency and inequality in healthcare. Risk selection may occur because of selection bias in the outcomes that are evaluated and rewarded, or due to the selection of lower cost patients. Risk selection may also stem from professional reputation. The motivation to engage in risk selection may also arise from differences in the meaning of value. To mitigate these unintended consequences, several strategies can be adopted. These include making value-based payment models attractive, but not mandatory, as well as incentivising transparent reporting of best practices, using adequate risk adjustment, expanding performance metrics, and including patient-reported experience measures. Other mitigation strategies could include adopting a mixture of performance measures, using mixed methods of paying physicians, and implementing monitoring and evaluation mechanisms. However, such approaches are not flawless, and the problem may never be fully solved. This perspective serves as a warning for the constant presence of risk selection, as well as informing policy makers, politicians, and organisations implementing VBP models on ways to minimise the possibility of risk selection.
Subject(s)
Health Facilities , Value-Based Health Care , Humans , Hospitals , Administrative Personnel , BenchmarkingABSTRACT
Evolutionary models are used to study the self-organisation of collective action, often incorporating population structure due to its ubiquitous presence and long-known impact on emerging phenomena. We investigate the evolution of multiplayer cooperation in mobile structured populations, where individuals move strategically on networks and interact with those they meet in groups of variable size. We find that the evolution of multiplayer cooperation primarily depends on the network topology and movement cost while using different stochastic update rules seldom influences evolutionary outcomes. Cooperation robustly co-evolves with movement on complete networks and structure has a partially detrimental effect on it. These findings contrast an established principle from evolutionary graph theory that cooperation can only emerge under some update rules and if the average degree is lower than the reward-to-cost ratio and the network far from complete. We find that group-dependent movement erases the locality of interactions, suppresses the impact of evolutionary structural viscosity on the fitness of individuals, and leads to assortative behaviour that is much more powerful than viscosity in promoting cooperation. We analyse the differences remaining between update rules through a comparison of evolutionary outcomes and fixation probabilities.
Subject(s)
Biological Evolution , Game Theory , Humans , Cooperative Behavior , Reward , ProbabilityABSTRACT
Healthy brains display a wide range of firing patterns, from synchronized oscillations during slowwave sleep to desynchronized firing during movement. These physiological activities coexist with periods of pathological hyperactivity in the epileptic brain, where neurons can fire in synchronized bursts. Most cortical neurons are pyramidal regular spiking cells (RS) with frequency adaptation and do not exhibit bursts in current-clamp experiments ( in vitro ). In this work, we investigate the transition mechanism of spike-to-burst patterns due to slow potassium and calcium currents, considering a conductance-based model of a cortical RS cell. The joint influence of potassium and calcium ion channels on high synchronous patterns is investigated for different synaptic couplings ( g syn ) and external current inputs ( I ). Our results suggest that slow potassium currents play an important role in the emergence of high-synchronous activities, as well as in the spike-to-burst firing pattern transitions. This transition is related to bistable dynamics of the neuronal network, where physiological asynchronous states coexist with pathological burst synchronization. The hysteresis curve of the coefficient of variation of the inter-spike interval demonstrates that a burst can be initiated by firing states with neuronal synchronization. Furthermore, we notice that high-threshold ( I L ) and low-threshold ( I T ) ion channels play a role in increasing and decreasing the parameter conditions ( g syn and I ) in which bistable dynamics occur, respectively. For high values of I L conductance, a synchronous burst appears when neurons are weakly coupled and receive more external input. On the other hand, when the conductance I T increases, higher coupling and lower I are necessary to produce burst synchronization. In light of our results, we suggest that channel subtype-specific pharmacological interactions can be useful to induce transitions from pathological high bursting states to healthy states.
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A strategy for determining the bioaccessibility of bromine and iodine from edible seaweeds was proposed for the first time using microwave-induced combustion (MIC) and ion chromatography coupled to mass spectrometry (IC-MS) after in vitro digestion. The concentrations of bromine and iodine in edible seaweeds using the proposed methods (MIC and IC-MS) were not statistically different from those using MIC and inductively coupled plasma mass spectrometry (p > 0.05). Trueness was assessed by recovery experiments (101-110%, relative standard deviation <10%). Following an in vitro digestion protocol, MIC was proposed as sample preparation for bioaccessible and residual fractions. Using this strategy, the mass balance totaled from 97 to 111%. No statistical difference (p > 0.05) was observed between the total concentration of bromine or iodine and their concentration in bioaccessible and residual fractions for three edible seaweed species, indicating full analyte quantification in the fractions.
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Evidence on the potential for value-based payment models to improve quality of care and ensure more efficient outcomes is limited and mixed. We aim to identify the factors that enhance or inhibit the design, implementation, and application of these models through a systematic literature review. We used the PRISMA guidelines. The facilitating and inhibiting factors were divided into subcategories according to a theoretical framework. We included 143 publications, each reporting multiple factors. Facilitators on objectives and strategies, such as realistic/achievable targets, are reported in 56 studies. Barriers regarding dedicated time and resources (e.g., an excessive amount of time for improvements to manifest) are reported in 25 studies. Consensus within the network regarding objectives and strategies, trust, and good coordination is essential. Health care staff needs to be kept motivated, well-informed, and actively involved. In addition, stakeholders should manage expectations regarding when results are expected to be achieved.
Subject(s)
Delivery of Health Care , HumansABSTRACT
INTRODUCTION: Value-based healthcare has potential for cost control and quality improvement. To assess this, we review the evidence on the impact of value-based payment (VBP) models in the context of networks of care (NOC) and transmural care. METHODS: We used the PRISMA guidelines for this systematic literature review. We searched eight databases in July 2021. Subsequently, we conducted title and abstract and full-text screenings, and extracted information in an extraction matrix. Based on this, we assessed the evidence on the effects of VBP models on clinical outcomes, patient-reported outcomes/experiences, organization-related outcomes/experiences, and costs. Additionally, we reviewed the facilitating and inhibiting factors per VBP model. FINDINGS: Among articles studying shared savings and pay-for-performance models, most outline positive effects on both clinical and cost outcomes, such as preventable hospitalizations and total expenditures, respectively. Most studies show no change in patient satisfaction and access to care when adopting VBP models. Providers' opinions towards the models are frequently negative. Transparency and communication among involved stakeholders are found to be key facilitating factors, transversal to all models. Additionally, a lack of trust is an inhibitor found in all VBP models, together with inadequate targets and insufficient incentives. In bundled payment and pay-for-performance models, complexity in the structure of the program and lack of experience in implementing required mechanisms are key inhibitors. CONCLUSIONS: The overall positive effect on clinical and cost outcomes validates the success of VBP models. The mostly negative effects on organization-reported outcomes/experiences are corroborated by findings regarding providers' lack of awareness, trust, and engagement with the model. This may be justified by their exclusion from the design of the models, decreasing their sense of ownership and, therefore, motivation. Incentives, targets, benchmarks, and quality measures, if adequately designed, seem to be important facilitators, and if lacking or inadequate, they are key inhibitors. These are prominent facilitators and inhibitors for P4P and shared savings models but not as prominent for bundled payments. The complexity of the scheme and lack of experience are prominent inhibitors in all VBP models, since all require changes in several areas, such as behavioral, process, and infrastructure.
Subject(s)
Delivery of Health Care , Reimbursement, Incentive , Humans , Quality Improvement , Hospitalization , Cost ControlABSTRACT
The APOBEC3 (A3) proteins are cytidine deaminases that exhibit the ability to insert mutations in DNA and/or RNA sequences. APOBEC3B (A3B) has been evidenced as a DNA mutagen with consistent high expression in several cancer types. Data concerning the A3B influence on HPV infection and cervical cancer are limited and controversial. We investigated the role of A3B expression levels in cervical cancer in affected women positive for infection by different HPV types. Tumor biopsies from cancerous uterine cervix were collected from 216 women registered at Hospital do Câncer II of Instituto Nacional de Câncer, and infecting HPV was typed. A3B expression levels were quantified from RNA samples extracted from cervical biopsies using real-time quantitative PCR. Median A3B expression levels were higher among HPV18+ samples when compared to HPV16+ counterparts and were also increased compared to samples positive for other HPV types. In squamous cell carcinoma, HPV18+ samples also showed increased median A3B expression when compared to HPV Alpha-9 species or only to HPV16+ samples. Our findings suggest that A3B expression is differentially upregulated in cervical cancer samples infected with HPV18. A3B could be potentially used as a biomarker for HPV infection and as a prognostic tool for clinical outcomes in the context of cervical cancer.
Subject(s)
Cytidine Deaminase , Papillomavirus Infections , Uterine Cervical Neoplasms , Female , Humans , Cytidine Deaminase/genetics , DNA , Human papillomavirus 18 , Minor Histocompatibility Antigens/genetics , Papillomavirus Infections/complications , Papillomavirus Infections/genetics , RNA, Messenger/genetics , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/virologyABSTRACT
The increased demands and dependence on depleted oil reserves, accompanied by global warming and climate change have driven the world to explore and develop new strategies for global sustainable development. Among sustainable biomass sources, microalgae represent a promising alternative to fossil fuel and can contribute to the achievement of important Sustainable Development Goals (SDGs). This article has reviewed the various applications of microalgal biomass that includes (i) the use in aquaculture and its sustainability; (ii) commercial value and emerging extraction strategies of carotenoids; (iii) biofuels from microalgae and their application in internal combustion engines; (iv) the use and reuse of water in microalgae cultivation; and (v) microalgae biotechnology as a key factor to assist SDGs. The future prospects and challenges on the microalgae circular bio economy, issues with regard to the scale-up and water demand in microalgae cultivation are also highlighted.
Subject(s)
Microalgae , Biofuels , Biomass , Sustainable Development , WaterABSTRACT
Peridinin is a light-harvesting carotenoid present in phototrophic dinoflagellates and has great potential for new drug applications and cosmetics development. Herein, the effects of irradiance mediated by light-emitting diodes on growth performance, carotenoid and fatty acid profiles, and antioxidant activity of the endosymbiotic dinoflagellate Durusdinium glynnii were investigated. The results demonstrate that D. glynnii is particularly well adapted to low-light conditions; however, it can be high-light-tolerant. In contrast to other light-harvesting carotenoids, the peridinin accumulation in D. glynnii occurred during high-light exposure. The peridinin to chlorophyll-a ratio varied as a function of irradiance, while the peridinin to total carotenoids ratio remained stable. Under optimal irradiance for growth, there was a peak in docosahexaenoic acid (DHA) bioaccumulation. This study contributes to the understanding of the photoprotective role of peridinin in endosymbiont dinoflagellates and highlights the antioxidant activity of peridinin-rich extracts. KEY POINTS: ⢠Peridinin has a protective role against chlorophyll photo-oxidation ⢠High light conditions induce cellular peridinin accumulation ⢠D. glynnii accumulates high amounts of DHA under optimal light supply.
Subject(s)
Dinoflagellida , Antioxidants , Carotenoids , Chlorophyll , Docosahexaenoic AcidsABSTRACT
A new family of hypervalent iodine reagents containing transferable primary amine groups is described. Benziodoxolone-based reagents were synthesized on the gram-scale through operationally simple reactions in up to quantitative yields. These bench-stable solids were characterized by X-ray analysis and successfully employed in the α-amination of indanone-based ß-ketoesters in up to 83% yield. Mechanistic studies indicate a substitution mechanism involving an electrophilic amine.