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1.
Nat Commun ; 12(1): 3426, 2021 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-34103516

RESUMO

Adaptive plasticity in stress responses is a key element of plant survival strategies. For instance, moderate heat stress (HS) primes a plant to acquire thermotolerance, which allows subsequent survival of more severe HS conditions. Acquired thermotolerance is actively maintained over several days (HS memory) and involves the sustained induction of memory-related genes. Here we show that FORGETTER3/ HEAT SHOCK TRANSCRIPTION FACTOR A3 (FGT3/HSFA3) is specifically required for physiological HS memory and maintaining high memory-gene expression during the days following a HS exposure. HSFA3 mediates HS memory by direct transcriptional activation of memory-related genes after return to normal growth temperatures. HSFA3 binds HSFA2, and in vivo both proteins form heteromeric complexes with additional HSFs. Our results indicate that only complexes containing both HSFA2 and HSFA3 efficiently promote transcriptional memory by positively influencing histone H3 lysine 4 (H3K4) hyper-methylation. In summary, our work defines the major HSF complex controlling transcriptional memory and elucidates the in vivo dynamics of HSF complexes during somatic stress memory.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas , Fatores de Transcrição de Choque Térmico/metabolismo , Resposta ao Choque Térmico/genética , Complexos Multiproteicos/metabolismo , Transcrição Genética , Proteínas de Arabidopsis/genética , Epistasia Genética , Genes de Plantas , Loci Gênicos , Fatores de Transcrição de Choque Térmico/genética , Histonas/metabolismo , Cinética , Lisina/metabolismo , Metilação , Plantas Geneticamente Modificadas , Regiões Promotoras Genéticas/genética , Ligação Proteica/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
2.
J Chromatogr A ; 1650: 462248, 2021 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-34087519

RESUMO

The biopharmaceutical industries are continuously faced with the pressure to reduce the development costs and accelerate development time scales. The traditional approach of heuristic-based or platform process-based optimization is soon getting obsolete, and more generalized tools for process development and optimization are required to keep pace with the emerging trends. Thus, advanced model-based methods that can reduce the can ensure accelerated development of robust processes with minimal experiments are necessary. Though mechanistic models for chromatography are quite popular, their success is limited by the need to have accurate knowledge of adsorption isotherms and mass transfer kinetics. As an alternative, in this work, a hybrid modeling approach is proposed. Thereby, the chromatographic unit behavior is learned by a combination of neural network and mechanistic model while fitting suitable experimental breakthrough curves. Since this approach does not require identifying suitable mechanistic assumptions for all the phenomena, it can be developed with lower effort. Thus, allowing the scientists to concentrate their focus on process development. The performance of the hybrid model is compared with the mechanistic Lumped kinetic Model for in-silico data and experiments conducted on a system of industrial relevance. The flexibility of the hybrid modeling approach results in about three times higher accuracies compared to Lumped Kinetic Model. This is validated for five different isotherm models used to simulate data, with the hybrid model showing about two to three times lower prediction errors in all the cases. Not only in prediction, but we could also show that the hybrid model is more robust in extrapolating across process conditions with about three times lower error than the LKM. Additionally, it could be demonstrated that an appropriately tailored formulation of the hybrid model can be used to generate representations for the underlying principles such as adsorption equilibria and mass transfer kinetics.


Assuntos
Técnicas de Química Analítica , Cromatografia , Simulação por Computador , Redes Neurais de Computação , Proteínas , Adsorção , Técnicas de Química Analítica/métodos , Cinética , Proteínas/isolamento & purificação
3.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072418

RESUMO

Staphylococcus aureus is one of the most prevalent pathogens associated with several types of biofilm-based infections, including infections of chronic wounds. Mature staphylococcal biofilm is extremely hard to eradicate from a wound and displays a high tendency to induce recurring infections. Therefore, in the present study, we aimed to investigate in vitro the interaction between S. aureus biofilm and fibroblast cells searching for metabolites that could be considered as potential biomarkers of critical colonization and infection. Utilizing advanced microscopy and microbiological methods to examine biofilm formation and the staphylococcal infection process, we were able to distinguish 4 phases of biofilm development. The analysis of staphylococcal biofilm influence on the viability of fibroblasts allowed us to pinpoint the moment of critical colonization-12 h post contamination. Based on the obtained model we performed a metabolomics analysis by 1H NMR spectroscopy to provide new insights into the pathophysiology of infection. We identified a set of metabolites related to the switch to anaerobic metabolism that was characteristic for staphylococcal biofilm co-cultured with fibroblast cells. The data presented in this study may be thus considered a noteworthy but preliminary step in the direction of developing a new, NMR-based tool for rapid diagnosing of infection in a chronic wound.


Assuntos
Biofilmes/crescimento & desenvolvimento , Técnicas de Cocultura , Fibroblastos/metabolismo , Fibroblastos/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo , Sobrevivência Celular , Fibroblastos/ultraestrutura , Imunofluorescência , Interações Hospedeiro-Patógeno , Cinética , Espectroscopia de Ressonância Magnética , Metaboloma , Metabolômica/métodos , Staphylococcus aureus/ultraestrutura
4.
Viruses ; 13(6)2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-34073577

RESUMO

Increasing evidence suggests that some newly emerged SARS-CoV-2 variants of concern (VoCs) resist neutralization by antibodies elicited by the early-pandemic wild-type virus. We applied neutralization tests to paired recoveree sera (n = 38) using clinical isolates representing the first wave (D614G), VoC1, and VoC2 lineages (B.1.1.7 and B 1.351). Neutralizing antibodies inhibited contemporary and VoC1 lineages, whereas inhibition of VoC2 was reduced 8-fold, with 50% of sera failing to show neutralization. These results provide evidence for the increased potential of VoC2 to reinfect previously SARS-CoV-infected individuals. The kinetics of NAbs in different patients showed similar decline against all variants, with generally low initial anti-B.1.351 responses becoming undetectable, but with anti-B.1.1.7 NAbs remaining detectable (>20) for months after acute infection.


Assuntos
Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , SARS-CoV-2/imunologia , Animais , Anticorpos Antivirais/imunologia , COVID-19/diagnóstico , COVID-19/virologia , Chlorocebus aethiops , Proteínas do Nucleocapsídeo de Coronavírus/imunologia , Humanos , Imunoglobulina G/imunologia , Cinética , Testes de Neutralização , Fosfoproteínas/imunologia , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Índice de Gravidade de Doença , Glicoproteína da Espícula de Coronavírus/imunologia , Células Vero
5.
Nat Commun ; 12(1): 3268, 2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-34075034

RESUMO

Halocyclization of alkenes is a powerful bond-forming tool in synthetic organic chemistry and a key step in natural product biosynthesis, but catalyzing halocyclization with high enantioselectivity remains a challenging task. Identifying suitable enzymes that catalyze enantioselective halocyclization of simple olefins would therefore have significant synthetic value. Flavin-dependent halogenases (FDHs) catalyze halogenation of arene and enol(ate) substrates. Herein, we reveal that FDHs engineered to catalyze site-selective aromatic halogenation also catalyze non-native bromolactonization of olefins with high enantioselectivity and near-native catalytic proficiency. Highly selective halocyclization is achieved by characterizing and mitigating the release of HOBr from the FDH active site using a combination of reaction optimization and protein engineering. The structural origins of improvements imparted by mutations responsible for the emergence of halocyclase activity are discussed. This expansion of FDH catalytic activity presages the development of a wide range of biocatalytic halogenation reactions.


Assuntos
Alcenos/metabolismo , Biocatálise , Flavinas/metabolismo , Oxirredutases/metabolismo , Alcenos/química , Domínio Catalítico/genética , Ciclização , Ensaios Enzimáticos , Flavinas/química , Halogenação , Cinética , Simulação de Acoplamento Molecular , Mutagênese , Mutação , Oxirredutases/química , Oxirredutases/genética , Engenharia de Proteínas , Estereoisomerismo
6.
Sensors (Basel) ; 21(10)2021 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-34069145

RESUMO

Exoskeletons are the mechanical systems whose operation is carried out in close cooperation with the human body. In this paper, the authors describe a mathematical model of the hydraulic exoskeleton of a lower limb. The coordinates of characteristic points of the exoskeleton in the sagittal plane as a function of user height are presented. The mathematical models, kinematics, and kinetics equations were determined. The masses of the actuators and their dimensions were selected based on catalog data. The force distribution in the wearable system during the squat is shown. The proposed models allowed us to determine the trajectory of individual points of the exoskeleton and to determine the forces in hydraulic cylinders that are necessary to perform a specific displacement. The simulation results show that the joint moments depend linearly on actuator forces. The dynamics equations of the wearable system are non-linear. The inertia of the system depends on the junction variables and it proves that there are dynamic couplings between the individual axes of the exoskeleton.


Assuntos
Exoesqueleto Energizado , Fenômenos Biomecânicos , Humanos , Cinética , Extremidade Inferior , Modelos Teóricos
7.
Sensors (Basel) ; 21(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34070081

RESUMO

Cell migration plays an important role in the identification of various diseases and physiological phenomena in living organisms, such as cancer metastasis, nerve development, immune function, wound healing, and embryo formulation and development. The study of cell migration with a real-time microscope generally takes several hours and involves analysis of the movement characteristics by tracking the positions of cells at each time interval in the images of the observed cells. Morphological analysis considers the shapes of the cells, and a phase contrast microscope is used to observe the shape clearly. Therefore, we developed a segmentation and tracking method to perform a kinetic analysis by considering the morphological transformation of cells. The main features of the algorithm are noise reduction using a block-matching 3D filtering method, k-means clustering to mitigate the halo signal that interferes with cell segmentation, and the detection of cell boundaries via active contours, which is an excellent way to detect boundaries. The reliability of the algorithm developed in this study was verified using a comparison with the manual tracking results. In addition, the segmentation results were compared to our method with unsupervised state-of-the-art methods to verify the proposed segmentation process. As a result of the study, the proposed method had a lower error of less than 40% compared to the conventional active contour method.


Assuntos
Processamento de Imagem Assistida por Computador , Microscopia , Algoritmos , Cinética , Reprodutibilidade dos Testes
8.
Med Probl Perform Art ; 36(2): 108-128, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34079984

RESUMO

AIMS: Understanding the biomechanics of jumping in ballet dancers provides an opportunity to optimize performance and mitigate injury risk. This systematic review aimed to summarize research investigating kinetics and kinematics of jumping in ballet dancers. METHODS: PubMed (MEDLINE), SPORTDiscus, and Web of Science were systematically searched for studies published before December 2020. Studies were required to investigate dancers specializing in ballet, assess kinetics or kinematics during take-off or landing, and be published in English. RESULTS: A total of 3,781 articles were identified, of which 29 met the inclusion criteria. Seven studies investigated take-off (kinetics: n = 6; kinematics: n = 4) and 23 studies investigated landing (kinetics: n = 19; kinematics: n = 12). Included articles were categorized into six themes: Activity Type (n = 10), Environment and Equipment (n = 10), Demographics (n = 8), Physical Characteristics (n = 3), Injury Status (n = 2), and Skill Acquisition and Motor Control (n = 1). Peak landing vertical ground reaction force (1.4-9.6 times body weight) was most commonly reported. Limited evidence suggests greater ankle involvement during the take-off of ballet jumps compared to countermovement jumps. There is also limited evidence indicating greater sagittal plane joint excursions upon landing in ballet dancers compared to non-dancers, primarily through a more extended lower extremity at initial contact. Only 4 articles investigated male ballet dancers, which is a notable gap in the literature. CONCLUSIONS: The findings of this review can be used by dance science and medicine practitioners to improve their understanding of jumping in ballet dancers.


Assuntos
Dança , Articulação do Tornozelo , Fenômenos Biomecânicos , Humanos , Cinética , Extremidade Inferior , Masculino
9.
Chemosphere ; 278: 130409, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126677

RESUMO

Testing and assessing the persistency, bioaccumulative and toxic properties of UVCBs (substances of Unknown or Variable composition, Complex reaction products or Biological materials) pose major technical and analytical challenges. The main aim of this study was to combine whole substance biodegradation testing with constituent specific analytics for determining primary biodegradation kinetics of the main UVCB constituents. An additional aim was to link the primary biodegradation kinetics of the main constituents to the bioaccumulation potential and baseline toxicity potential of the UVCB. Two closed biodegradation experiments were conducted using similar test systems but different analyses. The model substance, cedarwood Virginia oil, was tested at a low concentration and wastewater treatment plant effluent served as inoculum. We used microvolume solvent spiking for a quantitative mass transfer of the UVCB, while avoiding that co-solvent degradation would lead to anaerobic conditions. The biodegradation of UVCB constituents was determined with automated solid-phase microextraction coupled to GC-MS/MS using targeted analysis for main constituents and non-targeted analysis for minor constituents and non-polar degradation products. Primary biodegradation kinetics of main constituents, accounting for 73% w/w of the mixture, were successfully determined with degradation rate constants ranging from 0.09 to 0.25 d-1. Minor constituents were also degraded and non-polar degradation products were not observed. Finally, the bioaccumulation potential and baseline toxicity potential of the mixture at test start were calculated and both parameters decreased then substantially. The strength of the new approach is the possibility of biodegradation testing of a whole UVCB at low concentration while generating constituent specific biodegradation kinetics.


Assuntos
Óleos Voláteis , Espectrometria de Massas em Tandem , Biodegradação Ambiental , Cinética , Virginia
10.
Chemosphere ; 278: 130499, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126696

RESUMO

Quantitative insight into the HCO3--dependent degradation kinetics is critical to improve understanding of the UV processes for the most-cost effective application. In this study, we developed a kinetic model to precisely predict the kinetics in UV/H2O2 and UV/chlorine processes. The second-order rate constants of HO, Cl, ClO, Cl2-, and CO3- with carbamazepine (CBZ) were fitted as 1.3 × 109, 1.9 × 109, 1.8 × 106, 1.1 × 105, and 4.5 × 106 M-1 s-1, respectively. Based on the model, we investigated the significant impact of bicarbonate (HCO3-) and subsequently generated carbonate radical (CO3-) on CBZ degradation, radical chemistry, and energy requirement of UV/H2O2 and UV/chlorine processes. The presence of HCO3- inhibited CBZ degradation in UV/H2O2 and UV/chlorine processes to different degree. Contributions of HO, Cl, ClO, Cl2-, and CO3- to CBZ degradation in UV/H2O2 and UV/chlorine processes in the absence/presence of HCO3- were investigated. HO and CO3- make comparable contributions to CBZ degradation in UV/H2O2 process in the presence of HCO3- (2 mM), while ClO is always the main contributor at various HCO3- concentration of 0-2 mM. Furthermore, the presence of HCO3- in both processes increased the corresponding EE/O, when CBZ was degraded by an order of magnitude. Overall, HCO3- and CO3- influence the reactions and mechanism of UV/H2O2 and UV/chlorine processes, and have higher impact on UV/H2O2 process.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Carbonatos , Cloro , Peróxido de Hidrogênio , Cinética , Oxirredução , Raios Ultravioleta , Poluentes Químicos da Água/análise
11.
Chemosphere ; 278: 130507, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126699

RESUMO

A novel Lanthanum phosphate polyaniline (LaPO4-PANI) nanocomposite was synthesized by the simple sol-gel technique. The nanocomposite prepared at 1:1 ratio provided the highest ion exchange capacity and selective adsorption of Cr(VI). The phase composition and particle morphology of the as-prepared material was evaluated by XRD, FESEM and TEM analyses. The FTIR, Raman, and TGA data inferred the definite chemical interaction between the organic and inorganic counterparts in the formation of LaPO4-PANI. The selective adsorption of Cr(VI) was estimated by evaluating the distribution coefficient, electrical double layer theory as well as valency and Pauling's ionic radii of interfering ions (phosphate, iodide, sulfate, chloride, sulfide). The high tolerance capability of LaPO4-PANI against the interfering ions made it appropriate for selective and efficient removal of Cr(VI) ions from solutions. The nanocomposite showed the highest removal percentage of 98.6% towards Cr(VI) in a wide pH range of 2-6 at room temperature, as compared to sole lanthanum phosphate (56%) and polyaniline (75%). The XPS analysis revealed the adsorption mechanism due to the combined effect of both adsorption and reduction. Cr(VI) is adsorbed through electrostatic interactions while the = N-/-NH- group facilitated the in situ chemical reduction. The procured results make the LaPO4-PANI nanocomposite a promising adsorbent for the removal of Cr(VI).


Assuntos
Nanocompostos , Poluentes Químicos da Água , Adsorção , Compostos de Anilina , Cromo/análise , Cinética , Lantânio , Fosfatos , Poluentes Químicos da Água/análise
12.
BMJ Open ; 11(6): e047548, 2021 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-34108168

RESUMO

INTRODUCTION: Intra-articular (IA) and peri-articular glucocorticoid (GC) injections are common in sports medicine. However, from 1 January 2022, all injectable GC routes (including IA administration) will be prohibited in-competition by World Anti-Doping Agency (WADA). Owing to these rules, an IA GC treatment out-of-competition could result in an adverse analytical finding in-competition if the washout period is not clearly defined. The aim of this study is to determine the urinary excretion profile of triamcinolone acetonide following IA injection to strengthen the definition of the washout periods. METHODS AND ANALYSIS: This is a prospective multicentre trial to include 20 subjects who practice sports for at least 4 hours/week and present a knee disorder requiring IA injection of triamcinolone acetonide for therapeutic purposes. To determine the excretion profile of triamcinolone acetonide in both urine and blood following IA injection of the drug, We will perform 20 urinary tests and 20 dried blood spot tests, two prior to GC injection (baseline) and the last one at 35 days. Analyses will be performed by the French antidoping agency laboratory in accordance with WADA standards and regulations. ETHICS AND DISSEMINATION: The study protocol was approved by the French ethics committee (CPP Sud Est III-Lyon-2020-070B on 06 October 2020). All subjects will provide written informed consent. The results of this study will be accessible in peer-reviewed publication and be presented at academic conference. TRIAL REGISTRATION NUMBER: NCT04574232.


Assuntos
Osteoartrite do Joelho , Triancinolona Acetonida , Humanos , Injeções Intra-Articulares , Cinética , Estudos Multicêntricos como Assunto , Osteoartrite do Joelho/tratamento farmacológico , Estudos Prospectivos
13.
Water Sci Technol ; 83(11): 2629-2639, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115618

RESUMO

Organic esters of phosphoric acid and other organophosphorous compounds are enzymatically hydrolyzed during wastewater treatment by microbial phosphoesterases, especially by phosphomonoesterase (phosphatase). For physiological reasons, the enzyme is inhibited by its main inorganic reaction product, ortho-phosphate. It is known that oxyanions of transition metals, resembling the molecular topology of ortho-phosphate, e.g. vanadate and tungstate, are more potent inhibitors for microbial alkaline phosphatase than phosphate. To proof this effect for activated sludge, a multitude of samples from a communal wastewater treatment plant was exposed at pH values from 7.00 to 8.50 to tungstate, vanadate, and molybdate. Inhibition effects were determined by a sensitive fluorimetric microplate assay and characteristic parameters (IC50 and IC20 concentrations) were deduced from modelled dose-response functions. Mean inhibitor concentrations (in brackets: ranges) causing 50% inactivation (IC50) at pH 7.50 were 2.5 (1.3-4.1) µM tungstate, 2.9 (1.6-5.5) µM vanadate, and 41.4 (33.6-56.7) µM molybdate. Vanadate and tungstate concentrations between 0.6 and 0.7 µM provoked a 20% (IC20) inhibition. The inhibition efficiency of tungstate and molybdate decreased with increasing pH, whereas vanadate reacted pH independently. These results underline the necessity to consider enzyme inhibition assessing the limitations and potentials of biological wastewater treatment processes.


Assuntos
Monoéster Fosfórico Hidrolases , Esgotos , Cinética , Molibdênio , Fosfatos , Vanadatos
14.
Water Sci Technol ; 83(11): 2714-2723, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115625

RESUMO

The textile industry is one of the main generators of industrial effluent due to the large volumes of water containing a wide variety of pollutants, including dyes. Thus, the present study aimed to remove the Disperse Blue 56 dye present in synthetic textile effluent using ionic flocculation through surfactant flocs produced from animal/vegetable fat, assessing the system at different surfactant concentrations and temperatures. The process kinetics, adsorption mechanism and equilibrium were evaluated. The results show that the kinetics was better described by the Elovich model when compared to pseudo-first order and pseudo-second order models, indicating that chemical adsorption occurs during the process. The study of the adsorption mechanism obtained lower outer layer diffusivities than their intra-particle counterparts, demonstrating that the dye transport to the surfactant floc is controlled through the outer layer. The Langmuir isotherm was suitable for equilibrium data and the separation factor calculated showed that the isotherm is classified as favorable. Dye removal efficiency reached 87% after 360 minutes of contact between the effluent and the surfactant flocs, indicating that ionic flocculation is an efficient alternative in the treatment of textile effluent containing disperse dye.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Adsorção , Antraquinonas , Corantes , Floculação , Concentração de Íons de Hidrogênio , Cinética , Indústria Têxtil , Têxteis , Poluentes Químicos da Água/análise
15.
Water Sci Technol ; 83(11): 2793-2808, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34115632

RESUMO

In this work, mixed oxides of LaxCa1-xMnO3 perovskite type (x = 0, 0.5 and 1.0) were synthesized through modified proteic method using collagen and calcination process at 700 °C/2 h in order to remove the commercial textile dye Bezaktiv Blue S-MAX from water. Oxides were characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), N2 physisorption, scanning electron microscopy (SEM) and point of zero charge (PZC) techniques while the dye only by the first two techniques. The XRD showed that perovskite monophase was obtained for x = 0.5 and 1.0. However, for x = 0, the low crystalline perovskite phase was obtained in the midst of precursor oxides. FTIR showed the adsorption process did not damage the adsorbents structure. The successful obtained materials have meso and macroporous with slit or cavity shape, rough surface and particles with varying sizes. The pseudo-second-order model was the one that best fit the kinetic data. The process must occur through electrostatic surface interactions between the adsorbent surface and the dye molecule. For the equilibrium study, Langmuir isotherm is the most suitable when using LaMnO3 adsorbent, while Freundlich isotherm was better suited when used the other two materials. The adsorbents were termally regenerated and reused five times. The best performance was exhibited by LaMnO3.


Assuntos
Poluentes Químicos da Água , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia de Infravermelho com Transformada de Fourier , Água , Poluentes Químicos da Água/análise
16.
Sci Rep ; 11(1): 11606, 2021 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078929

RESUMO

The devastating trail of Covid-19 is characterized by one of the highest mortality-to-infected ratio for a pandemic. Restricted therapeutic and early-stage vaccination still renders social exclusion through lockdown as the key containment mode.To understand the dynamics, we propose PHIRVD, a mechanistic infection propagation model that Machine Learns (Bayesian Markov Chain Monte Carlo) the evolution of six infection stages, namely healthy susceptible (H), predisposed comorbid susceptible (P), infected (I), recovered (R), herd immunized (V) and mortality (D), providing a highly reliable mortality prediction profile for 18 countries at varying stages of lockdown. Training data between 10 February to 29 June 2020, PHIRVD can accurately predict mortality profile up to November 2020, including the second wave kinetics. The model also suggests mortality-to-infection ratio as a more dynamic pandemic descriptor, substituting reproduction number. PHIRVD establishes the importance of early and prolonged but strategic lockdown to contain future relapse, complementing futuristic vaccine impact.


Assuntos
COVID-19/epidemiologia , COVID-19/prevenção & controle , Número Básico de Reprodução , Teorema de Bayes , COVID-19/etiologia , Controle de Doenças Transmissíveis/métodos , Comorbidade , Suscetibilidade a Doenças , Humanos , Imunidade Coletiva , Índia/epidemiologia , Cinética , Aprendizado de Máquina , Cadeias de Markov , Modelos Teóricos , Método de Monte Carlo , Mortalidade , Reino Unido/epidemiologia
17.
Anal Chim Acta ; 1170: 338625, 2021 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-34090589

RESUMO

The tris-nitrilotriacetic acid (tris-NTA) chip has been used for surface plasmon resonance (SPR) kinetic studies involving histidine (His)-tagged proteins. However, its full potential, especially for analyte quantification in complex biological media, has not been realized due to a lack of systematic studies on the factors governing ligand immobilization, surface regeneration, and data analysis. We demonstrate that the tris-NTA chip not only retains His-tagged proteins more strongly than its mono-NTA counterpart, but also orients them more uniformly than protein molecules coupled to carboxymethylated dextran films. We accurately and rapidly quantified immunoglobulin (IgG) molecules in sera by using the initial association phase of their conjugation with His-tagged protein G densely immobilized onto the tris-NTA chip, and established criteria for selecting the optimal time for constructing the calibration curve. The method is highly reproducible (less than 2% RSD) and three orders of magnitude more sensitive than immunoturbidimetry. In addition, we found that the amount of His-protein immobilized is highly dependent on the protein isoelectric point (pI). Reliable kinetic data in a multi-channel SPR instrument can also be rapidly obtained by using a low density of immobilized His-tagged protein. The experimental parameters and procedures outlined in this study help expand the range of SPR applications involving His-tagged proteins.


Assuntos
Ácido Nitrilotriacético , Ressonância de Plasmônio de Superfície , Biomarcadores , Histidina , Cinética
18.
Chemosphere ; 276: 130156, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088081

RESUMO

This study investigates the potential role of Bacillus sp. FA4 for the bioremediation of fipronil in a contaminated environment and resource recovery from natural sites. The degradation parameters for fipronil were optimized using response surface methodology (RSM): pH - 7.0, temperature - 32 °C, inocula - 6.0 × 108 CFU mL-1, and fipronil concentration - 50 mg L-1. Degradation of fipronil was confirmed in the mineral salt medium (MSM), soil, immobilized agar discs, and sodium alginate beads. The significant reduction of the half-life of fipronil suggested that the strain FA4 could be used for the treatment of large-scale fipronil degradation from contaminated environments. The kinetic parameters, such as qmax, Ks, and Ki for fipronil degradation with strain FA4, were 0.698 day-1, 12.08 mg L-1, and 479.35 mg L-1, respectively. Immobilized FA4 cells with sodium alginate and agar disc beads showed enhanced degradation with reductions in half-life at 7.83 and 7.34 days, respectively. The biodegradation in soil further confirmed the degradation potential of strain FA4 with a half-life of 7.40 days as compared to the sterilized soil control's 169.02 days. The application of the strain FA4 on fipronil degradation, under different in vitro conditions, showed that the strain could be used for bioremediation and resource recovery of contaminated wastewater and soil in natural contaminated sites.


Assuntos
Bacillus , Poluentes do Solo , Índia , Cinética , Pirazóis , Microbiologia do Solo , Poluentes do Solo/análise
19.
Chemosphere ; 276: 130191, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088088

RESUMO

In this study, Levenberg Marquardt back propagation algorithm was used to train the Artificial Neural Network (ANN) and to predict the adsorptive removal of cationic dye Basic Violet 03 (BV03) by biochar derived from biowaste of groundnut hull. The experimental conditions such as solution pH, biochar dose, initial dye concentration, contact time and temperature were used as input variables and BV03 percentage removal as target. The hidden and the output layer of the network was trained by tangent sigmoid and liner transfer functions. The feasibility of the adsorption process is evaluated by the kinetic studies and it exhibited that pseudo-second order kinetic models fit well with experimental data. The adsorbent stability and adsorption mechanism has been discoursed by the thermodynamic characteristics and sorption free energy. The predicted target values were compared with the experiment resulted in a better correlation coefficient of 0.9920. Thus, the results attained from this ANN model was found to be effective in predicting the percentage removal of BV03 dye at any given operating condition.


Assuntos
Redes Neurais de Computação , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Termodinâmica
20.
Chemosphere ; 276: 130193, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34088089

RESUMO

The gas-phase reaction of trans-2-pentenal (T2P) with Cl atoms was studied at atmospheric pressure and room temperature. A rate coefficient of (2.56 ± 0.83) × 10-10 cm3 molecule-1 s-1 was obtained using the relative rate method and isoprene, cyclohexane and ethanol as reference compounds. The kinetic study was carried out using a 300-L Teflon bag simulation chamber (IMT Lille Douai-France) and a 16-L Pyrex cell (UCLM-Ciudad Real-Spain), both coupled to the Fourier transform infrared (FTIR) technique. Gas-phase products and secondary organic aerosol (SOA) formation were studied at UCLM using a 16-L Pyrex cell and a 264-L quartz simulation chamber coupled to the FTIR and gas-chromatography-mass spectrometry (GC-MS) techniques. HCl, CO, and propanal were identified as products formed from the studied reaction and quantified by FTIR, the molar yield of the latter being (5.2 ± 0.2)%. Formic acid was identified as a secondary product and was quantified by FTIR with a yield of (6.2 ± 0.4)%. In addition, 2-chlorobutanal and 2-pentenoic acid were identified, but not quantified, by GC-MS as products. The SOA formation was investigated using a fast mobility particle sizer spectrometer. The observed SOA yields reached maximum values of around 7% at high particle mass concentrations. This work provides the first study of the formation of gaseous and particulate products for the reaction of Cl with T2P. A reaction mechanism is suggested to explain the formation of the observed gaseous products. The results are discussed in terms of structure-reactivity relationship, and the atmospheric implications derived from this study are commented as well.


Assuntos
Cinética , Aerossóis , Aldeídos , França , Espanha
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