Effects Of Changes In Concentration Research Articles

Clustering-Triggered Emission Mechanism of Sulfur Ester-Polyacrylamide Aqueous Solution.

Most nonconventional luminogens enjoy good water solubility and biocompatibility, showing unique application prospects in fields like biological imaging. Although clustering-triggered emission (CTE) mechanisms have been proposed to explain such emissions, it has not been thoroughly elucidated, which limits their development and application. Herein, the photoluminescence properties of polyacrylamide prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization aqueous solution are utilized to further investigate the effects of changes in concentration, in order to elucidate the emission mechanism through transmission electron microscopy (TEM), small angle X-ray scattering (SAXS) and theoretical calculation. The results showed that the size distribution, morphology, and distance between the polymer clusters formed in the water solution are successfully correlated with the cluster emission centers. The emission mechanism of nonconventional luminogens solutions is more clearly and intuitively elucidated, which has a promoting effect on the emission and application of this field. It provides a strategy a strategy to clarify the CTE mechanism of nonconventional luminogens solution more clearly.

Clustering-triggered emission mechanism of carboxymethyl β-cyclodextrin aqueous solution and efficient recognition of Fe3+ in mixed ions.

Most nonconventional luminogens enjoy good water solubility and biocompatibility, showing unique application prospects in fields like biological imaging. Although clustering-triggered emission (CTE) mechanisms have been proposed to explain such emissions, the have not been thoroughly elucidated, which limits their development and application. Here, the photoluminescence properties of carboxymethyl β-cyclodextrin (CM-β-CD) aqueous solution are utilized to further investigate the effects of changes in concentration, in order to elucidate the emission mechanism through cryo-transmission electron microscopy (cryo-TEM), small-angle X-ray scattering (SAXS), molecular interaction analysis, and theoretical calculation. The results showed that the size distribution, morphology, and distance between water aggregates were successfully correlated with the cluster emission centers. The emission mechanism of nonconventional luminogen solutions was more clearly and intuitively elucidated, which has a promoting effect on the emission and application of this field. It is interesting that temperature-dependent emission spectra show the blue-shift phenomenon of PL with increasing excitation wavelengths. Moreover, due to its strong static quenching effect for Fe3+, CM-β-CD can efficiently detect Fe3+ in mixed-ion aqueous solutions. It provides a strategy to clarify the CTE mechanism of nonconventional luminogen solutions more clearly and its application of mixed-ion detection.

가상현실을 이용한 호흡근 훈련의 집중력 변화가 흡연자의 폐 기능에 미치는 효과

Purpose: This study aimed to investigate the effect of changes in concentration through respiratory muscle training using virtual reality on training concentration and pulmonary function in male smokers who have decreased concentration because of academics, employment, and smoking. Methods: The study included 15 male university students who had smoked for >2 years. They were randomly allocated to the control group (n=8) that performed respiratory muscle training using breathing exercise equipment and experimental group (n=7) that performed respiratory muscle training using virtual reality. The training was performed three times a day, three times a week, for a total of 4 weeks. During training, concentration was measured considering changes in the RAHB and heart rate variability (low frequency to high frequency [LF/HF] ratio) using QEEG-32FX, and pulmonary functions were measured based on changes in forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1), and FEV1/FVC using Spiropalm. Results: After the intervention, the experimental group showed significant improvement in the LF/HF ratio (p <.01), FVC (p<.05), and FEV1(p<.05), whereas the control group showed significant improvement in the LF/HF ratio (p<.05) and FVC(p<.05). Conclusion: The result of this study revealed that respiratory muscle training using virtual reality is more effective in improving pulmonary function by further enhancing training concentration.

フルムキン効果を表現する数式に関する一考察

Formula to express the Frumkin effect is reconsidered from the viewpoint of easiness of understanding its physical meaning. Although it is usually expressed based on the potential difference, here it is expressed based on the concentration changes. There are two aims of this formula transformation: One is to treat the Red / Ox species equally in the expression. The other is to extend the applicability of the formula to the effects of concentration changes caused by other than pure electrostatic effects.

Kinetic-model-based pathway optimization with application to reverse glycolysis in mammalian cells.

Over the last two decades, model-based metabolic pathway optimization tools have been developed for the design of microorganisms to produce desired metabolites. However, few have considered more complex cellular systems such as mammalian cells, which requires the use of nonlinear kinetic models to capture the effects of concentration changes and cross-regulatory interactions. In this study, we develop a new two-stage pathway optimization framework based on kinetic models that incorporate detailed kinetics and regulation information. In Stage 1, a set of optimization problems are solved to identify and rank the enzymes that contribute the most to achieving the metabolic objective. Stage 2 then determines the optimal enzyme interventions for specified desired numbers of enzyme adjustments. It also incorporates multi-scenario optimization, which allows the simultaneous consideration of multiple physiological conditions. We apply the proposed framework to find enzyme adjustments that enable a reverse glucose flow in cultured mammalian cells, thereby eliminating the need for glucose feed in the late culture stage and enhancing process robustness. The computational results demonstrate the efficacy of the proposed approach; it not only captures the important regulations and key enzymes for reverse glycolysis but also identifies differences and commonalities in the metabolic requirements for different carbon sources.

Screening of Low-Dosage Methanol as a Hydrate Promoter

We report a quantitative study of the effect of low-concentration methanol (MeOH) on the formation and dissociation of hydrates based on CH4 and CO2/N2 guest molecules. The kinetic promotion and dissociation ability of MeOH is also compared with the anionic surfactant sodium dodecyl sulfate (SDS, 100 ppm, 50 ppm). The effects of concentration changes (1 wt% and 5 wt%), pressure (p = 80–120 bar), guest molecules (CH4 and CO2), and temperature (1 °C and below 0 °C) are investigated using slow constant ramp (SCR) and isothermal (IT) temperature schemes. The results show that the kinetics are affected by the guest molecule and MeOH concentration. For CH4 gas, 5 wt% MeOH shows better promotion, while for CO2/N2 gas mixtures, 1 wt% MeOH gives better promotion. This conclusion agrees well with our previous results demonstrating optimal CH4 recovery and CO2 storage in the presence of 5 wt% MeOH. The promoting and inhibiting properties of MeOH could be beneficial in CH4 production from gas hydrate using CO2-rich gas injection, as delayed hydrate film formation in the presence of MeOH could improve both CH4 recovery and CO2 storage.

Polyvinyl alcohol and aminated cellulose nanocrystal membranes with improved interfacial compatibility for environmental applications

Biogas up-gradation is a useful method to control CO2 emission and enhance the green process. The demand for renewable sources is increasing due to the depletion of fossil fuels. Thin-film nanocomposites functionalized with tunable molecular-sieving nanomaterials have been employed to tailor membranes with enhanced permeability and selectivity. In this work, the cellulose nanocrystals as a filler in the polyvinyl alcohol matrix are prepared to achieve high-performance facilitated transport membranes for CO2 capture. Considering the mechanical stability, interfacial compatibility and high moisture uptake of the filler, the main objective of this work was to develop a novel aminated CNC (Am-CNC)/polyvinyl alcohol nanocomposite membrane for biogas upgrading. The hydroxyl groups (O–H) on the reducing end of the cellulose nanocrystals were replaced by amino groups (N–H2). It was discovered through Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) that adding Am-CNCs in PVA membranes shows an increment in the CO2 removal and effectively upgrades the biogas. The effect of change in concentration of Am-CNC and feed pressure was investigated. The results showed that with increasing Am-CNC concentration up to 1.5 wt%, the thickness of the selective membrane layer increased from 0.95 to 1.9 μm with a decrease in the moisture uptake from 85.04 to 58.84%. However, the best CO2 permeance and selectivity were achieved at 0.306 m3/m2.bar.h (STP) and 33.55, respectively. Furthermore, there was a more than two-fold decrease in CO2 permeance and a 27% decrease in the CO2/CH4 selectivity when the feed pressure increased from 5 to 15 bar. It was revealed that PVA/Am-CNC membrane is high performing for the biogas upgradation.

Plasmonic Au nanoparticles embedded in glass: Study of TOF-SIMS, XPS and its enhanced antimicrobial activities

The Au nanoparticles (NPs) were formed near the surfaces of pre-synthesized sodium zinc –borate glass by an ion exchange process obtained by thermal heat treatment in an open air environment at various temperatures. The pre-heated Au doped glass samples were extensively tested by the different techniques such as optical absorption spectroscopy, Scanning Electron Microscope (SEM), X-ray photoelectron spectroscopy (XPS), Time of Flight Secondary Ion Mass Spectroscopy (TOF-SIMS), and these Au NPs were used for the antimicrobial applications. SEM confirmed the spherical shaped Au NPs with increasing thermal treatment up to 550 °C. The optical absorption findings showed that the as –synthesized Au NPs showed Localized Surface Plasmon Resonance behaviour, giving clear evidence of an Au NPs band formed in the glass matrix. The formation mechanism of the Au doped glass samples was studied theoretically from a thermodynamic point of view during heat treatment. XPS and TOF-SIMS were used to study the chemical state and the thermal stability of the pre-heated Au NPs doped glasses in an ultra-high vacuum. The effect of concentration changes in the line-shape and in binding energy as a function of thermal heat treatment suggests that the Au NPs formed near the glass surfaces and changes in the chemical composition as well as chemical structures of the Au doped glass samples occurred. Antimicrobial activity such as antibacterial as well as antifungal activity of pre-heated Au doped glass samples was tested against different strains by the disk diffusion method. The Au doped glass samples exhibited enhanced antibacterial as well as antifungal activities by the influence of thermal treatment at different temperatures. Thus, the Au doped glass sample could be efficiently explored as a medical tool in pharmaceutical industries, biotechnology industries and chemical laboratories based upon its antibacterial findings. • Au NPs were embedded in the glass matrix by ion-exchange technique. • Au NPs were uniformly distributed in the glass matrix as confirmed by TEM analysis. • The antimicrobial properties were enhanced by increasing the annealing temperatures. • Thermodynamic approach was performed for the growth of the Au NPs. • The Au NPs exhibited invitro antifungal activities.

Synthesis of novel naphthalimide tethered 1,2,3-triazoles: In vitro biological evaluation and docking study of anti-inflammatory inhibitors

In this research work, a novel heterocyclic naphthalimide tethered 1,2,3-triazoles was synthesized by the approach of click chemistry. An entire compound's chemical structure was confirmed by spectral data of 1HNMR, 13CNMR and HR-MS. The structure of compound 10a was established by single crystal X-ray diffraction technique. The in vitro anti-inflammatory studies of compounds 6b, 10a and 10d at 200 µM exhibited potent selective inhibitions. The compound 10a shows 92.3 and 95.29% inhibition against the protein denaturation assays of bovin serum albumin and egg albumin, respectively. The compound 10a shows higher inhibitory activity compared to 6b and 10d. The molecular docking studies against COX1 and COX2 show that 10a shows a strong inhibitory effect owing to the significant free energy of binding -13.58 and -10.42 kcal/mol, respectively. The structure of compound 10a was optimized through DFT analysis. Statistical analysis using one way ANOVA was performed to study the effect of change in concentration of compounds on the percentage of inhibition.

Micellar enhanced flocculation for the effective removal of reactive yellow 160 from synthetic textile effluent

This work provides insight into the surfactant-based removal of reactive yellow 160 (RY-160) present in the aqueous medium. Micellar enhanced flocculation technique was applied and optimized for the said purpose. The mixture of anionic surfactants, obtained from a bio-degradable source (base soap), has been found to have great potential to solubilize dye molecules. The polyvalent salts are able to flocculate the micelles and help in their subsequent removal. The removal of dye was analyzed by the use of a UV/Visible spectrophotometer. Different factors such as the effect of change in concentration, pH, temperature, contact time, and electrolyte were studied to evaluate the adsorption characteristics and removal efficiency of the process. The data obtained was further used to study the mechanism of adsorption with the help of various models e.g., Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich (D–R). The kinetic parameters were also calculated by employing pseudo-1st and pseudo-2nd order kinetic models. Furthermore, thermodynamic calculations were performed to determine the change in Gibb’s free energy (ΔGo), enthalpy (ΔHo), and entropy (ΔSo). The results make it evident that the micellar flocculation-based adsorptive removal is an excellent and sustainable approach for the treatment of wastewater.

Sulphate radical enhanced photoelectrochemical degradation of sulfamethoxazole on a fluorine doped tin oxide - copper(I) oxide photoanode

• Visible light active FTO-Cu 2 O photoanode was successfully synthesised. • Sulphate radical was produced from persulphate salt at the surface of the Cu 2 O. • Degradation of sulfamethoxazole was markedly enhanced by sulphate radicals. • Mechanism of radicals generation and sulfamethoxazole degradation were proposed. • Application in real wastewater matrix was carried out with TOC removal of 43%. We report a sulphate radical enhanced photoelectrochemical degradation of sulfamethoxazole on a solar light driven fluorine doped tin oxide - copper(I) oxide photoanode. Copper(I) oxide was prepared by a template-free method and dispersed onto the surface of a fluorine doped tin oxide glass to form the photoanode. UV–Vis diffuse reflectance spectroscopy showed that the photoanode absorbed in the visible light region. With sodium persulphate as the source of sulphate radical, photoelectrochemical degradation studies showed that sodium persulphate markedly enhanced the degradation of sulfamethoxazole. Studies on the effects of change in concentration of the persulphate and the absence of the persulphate on the photoelectrocatalytic degradation process were conducted. Overall, the extent of degradation and mineralisation of sulfamethoxazole in water was found to be 86% and 67% respectively with bias potential of 1.5 V for the sulphate radical enhanced process. Scavenger studies showed that the photogenerated holes and sulphate radicals were the primary active species in the abatement of sulfamethoxazole. The effectiveness of sulfamethoxazole removal in real matrices by the use of FTO-Cu 2 O photoanode and sulphate radical was also confirmed.

Sulphate Radical Enhanced Photoelectrochemical Degradation of Sulfamethoxazole on a Fluorine Doped Tin Oxide - Copper(I) Oxide Photoanode

We report a sulphate radical enhanced photoelectrochemical degradation of sulfamethoxazole on a solar light driven fluorine doped tin oxide - copper(I) oxide photoanode. Copper(I) oxide was prepared by a template-free method and dispersed onto the surface of a fluorine doped tin oxide glass to form the photoanode. UV-Vis diffuse reflectance spectroscopy showed that the photoanode absorbed in the visible light region. With sodium persulphate as the source of sulphate radical, photoelectrochemical degradation studies showed that sodium persulphate markedly enhanced the degradation of sulfamethoxazole. Studies on the effects of change in concentration of the persulphate and the absence of the persulphate on the photoelectrocatalytic degradation process were conducted. Overall, the extent of degradation and mineralisation of sulfamethoxazole in water was found to be 86% and 67% respectively with bias potential of 1.5 V for the sulphate radical enhanced process. Scavenger studies showed that the photogenerated holes and sulphate radicals were the primary active species in the abatement of sulfamethoxazole.

Two-dimensional mid and near infrared correlation spectroscopy for bacterial identification

In recent years, near infrared (NIR) spectroscopy has gained interest as a tool for bacteria strain identification. Although some promising results suggest good applicability of the technique, a better interpretation of the NIR bacterial spectra is still needed. In order to analyze the NIR spectrum of biological samples, a correlation analysis between the NIR and the mid-infrared (mid-IR) spectra was performed. In total, 28 spectra of 8 bacterial strains were acquired and correlated in the NIR and the mid-IR spectral ranges. Some molecular bands (Amide I, P = O stretching, C-H stretching/deformation of polysaccharides) were well correlated, and the effect of concentration changes in these molecules were investigated. Moreover, a model for the NIR spectra classification was created with an overall 85% correct classification rate. Subsequently, only NIR wavelengths with high correlation to important mid-IR peaks were selected. This led to an increase in the correct classification rate to 94%. By correlation between well-established mid-IR peaks and NIR spectra, some relationships in the NIR spectra of biological samples were revealed, which was a step towards better understanding and interpretation of the NIR spectra of biological samples.

An electrodiffusive, ion conserving Pinsky-Rinzel model with homeostatic mechanisms.

In most neuronal models, ion concentrations are assumed to be constant, and effects of concentration variations on ionic reversal potentials, or of ionic diffusion on electrical potentials are not accounted for. Here, we present the electrodiffusive Pinsky-Rinzel (edPR) model, which we believe is the first multicompartmental neuron model that accounts for electrodiffusive ion concentration dynamics in a way that ensures a biophysically consistent relationship between ion concentrations, electrical charge, and electrical potentials in both the intra- and extracellular space. The edPR model is an expanded version of the two-compartment Pinsky-Rinzel (PR) model of a hippocampal CA3 neuron. Unlike the PR model, the edPR model includes homeostatic mechanisms and ion-specific leakage currents, and keeps track of all ion concentrations (Na+, K+, Ca2+, and Cl-), electrical potentials, and electrical conductivities in the intra- and extracellular space. The edPR model reproduces the membrane potential dynamics of the PR model for moderate firing activity. For higher activity levels, or when homeostatic mechanisms are impaired, the homeostatic mechanisms fail in maintaining ion concentrations close to baseline, and the edPR model diverges from the PR model as it accounts for effects of concentration changes on neuronal firing. We envision that the edPR model will be useful for the field in three main ways. Firstly, as it relaxes commonly made modeling assumptions, the edPR model can be used to test the validity of these assumptions under various firing conditions, as we show here for a few selected cases. Secondly, the edPR model should supplement the PR model when simulating scenarios where ion concentrations are expected to vary over time. Thirdly, being applicable to conditions with failed homeostasis, the edPR model opens up for simulating a range of pathological conditions, such as spreading depression or epilepsy.

Electrorheological Effects of Synthesized Octa-cyanopropylsilsesquioxane Cage Structure.

This article introduces a new electrorheological (ER) fluid. A molecular cage structure for electrorheological applications has been synthesized, and the ER behavior of the octa-functionalized polyhedral oligomeric silsesquioxane (POSS) variant in silicone oil (PDMS) has been shown. The hydrolyzation route has been used in the synthesis, the microstructure has been displayed using scanning electron microscopy, the yield has been ascertained, and the compound has been characterized. The rheological properties are demonstrated on the ER fluid through steady flow and oscillatory tests to investigate the effects of change in concentration on the functional group attached to the inorganic silicon–oxygen core structure of the POSS compound. The electrorheological efficiency was analyzed, and dielectric characterization was done. The flow curve was described by the Herschel–Bulkley model, and yield stress values were derived from the model. The octa-cyanoPOSS/PDMS electrorheological fluid has been shown to have ER activity.

PREPARATION AND EVALUATION OF FAST DISSOLVING TABLETS OF PITAVASTATIN BY 32 FULL FACTORIAL DESIGN

Objective: The objective of the present work was to prepare an optimized, fast dissolving tablet (FDT) of Pitavastatin to increase its dissolution by applying 32full factorial design.
 Methods: Nine formulations (PF1 to PF9) with all possible combinations according to 32full factorial design by selecting two factors i.e. concentration of super disintegrant, Indion414 (5-15%) (A) and sublimating agent, camphor (40-60%) (B) as independent variables at three levels of-1, 0 and 1. The effect of these two variables on three dependent parameters, water absorption ratio (Y1), disintegration time (Y2) and in vitro drug release (Y3) was studied. All the powder blends were evaluated for precompression parameters, and the tablets were prepared by direct compression method which were further evaluated for post-compression parameters. The effect of change in concentration of two selected factors on dependent parameters was studied through 3D surface response plots and polynomial equations using Design expert software version11. Optimized formula was obtained by desirability and overlay plots for which compatibility stability was assessed.
 Results: Precompression and post-compression parameters were satisfactorily within acceptable limits. Optimized formulation was prepared to prove the validity of the evolved mathematical model, which contained 6.75 mg of indion414(0.9) and 54 mg of camphor(0.9) with a disintegration time of 21 sec., water absorption ratio of 113 and 93% of drug release within 12 min. The compatibility between drugs and excipients was proved. The dissolution profiles of optimized formulation and commercially available conventional film-coated tablets of Pitavastatin were compared.
 Conclusion: The optimized formulation showed significantly (P>0.05) increased drug release compared to commercially available film-coated tablets. No changes in disintegration time, drug content and in in vitro drug release from optimized formulation on storage for 3months at 40 °C±2 °C/75% RH±5% RH were observed during stability studies which confirmed the stability of the optimized formulation.

Kinetics and mechanistic study of oxidation of paracetamol: an accelerated catalytic approach

In the present paper, a simple, and novel method for the abatement of paracetamol (PA) in aqueous system into environmental friendly compound benzoquinone at 308 K has been described, and was accelerated by simple, and inexpensive catalyst Cu(II)/Ni(II). A comparative assessment between Cu(II) and Ni(II)catalyzed, abatement of PA by CAT was performed. It has been determined that there are very little change in rate of reaction for both Cu(II)/Ni(II) catalyzed degradation of PA. All the kinetics parameters, i.e. the effect of change in concentrations of chloramine-T (CAT), sodium hydroxide, paracetamol, catalyst, added p-toluenesulfonamide, electrolyte etc. have been studied, and measured carefully. Reaction had been studied in the range of temperature 303–323 K. On the basis of kinetic data obtained a satisfactory mechanism has been proposed. And it was deduced that, presently used process was a tenable technique for the degradation of PA. Main abatement product was confirmed by GC–MS analysis technique.

Design and synthesis of porous M-ZnO/CeO2 microspheres as efficient plasmonic photocatalysts for nonpolar gaseous molecules oxidation: Insight into the role of oxygen vacancy defects and M=Ag, Au nanoparticles

In this paper, porous microsphere M-ZnO/CeO2 (M = Ag, Au) plasmonic photocatalyst was prepared through a simple hydrothermal method and in situ photo-deposition. This photocatalyst shows excellent stability and high efficiency in the complete mineralization of nonpolar gaseous molecules (CH4 and C2H4) under the simulated sunlight. The appreciable performance improvements are caused by the formation of heterojunctions and oxygen vacancy defects, the surface plasmon resonance (SPR) of noble metal nanoparticles as well as the 3D porous microsphere structures. Especially in this work, we systematically studied the effect of concentration changes of oxygen vacancy defects on photocatalytic performance by XPS, EPR and Raman characterization. Furthermore, a possible mechanism of photo-oxidation reaction in plasmonic photocatalyst system is discussed below. This study provides new inspiration for designing other plasmonic photocatalysts to remove nonpolar gaseous molecules.

In vitro model of the glial scar.

The trauma of central nervous system (CNS) can lead to glial scar, and it can limit the regeneration of neurons at the injured area, which is considered to be a major factor affecting the functional recovery of patients with CNS injury. At present, the study of the glial scar model in vitro is still limited to two-dimensional culture, and the state of the scar in vivo cannot be well mimicked. Therefore, we use a collagen gel and astrocytes to construct a three-dimensional (3D) model in vitro to mimic natural glial scar tissue. The effects of concentration changes of astrocytes on cell morphology, proliferation, and tissue performance were investigated. After 8 days of culture in vitro, the results showed that the tissue model contracted, with a measured shrinkage rate of 4.5%, and the compressive elastic modulus increased to nearly 4 times. Moreover, the astrocytes of the 3D tissue model have the ability of proliferation, hyperplasia, and formation of scar clusters. It indicates that the model we constructed has the characteristics of glial scar tissue to some extent and can provide an in vitro model for the research of glial scar and brain diseases.

Saccharomyces cerevisiae Exponential Growth Kinetics in Batch Culture to Analyze Respiratory and Fermentative Metabolism.

Saccharomyces cerevisiae cells in the exponential phase sustain their growth by producing ATP through fermentation and/or mitochondrial respiration. The fermentable carbon concentration mainly governs how the yeast cells generate ATP; thus, the variation in fermentable carbohydrate levels drives the energetic metabolism of S. cerevisiae. This paper describes a high-throughput method based on exponential yeast growth to estimate the effects of concentration changes and nature of the carbon source on respiratory and fermentative metabolism. The growth of S. cerevisiae is measured in a microplate or shaken conical flask by determining the optical density (OD) at 600 nm. Then, a growth curve is built by plotting OD versus time, which allows identification and selection of the exponential phase, and is fitted with the exponential growth equation to obtain kinetic parameters. Low specific growth rates with higher doubling times generally represent a respiratory growth. Conversely, higher specific growth rates with lower doubling times indicate fermentative growth. Threshold values of doubling time and specific growth rate are estimated using well-known respiratory or fermentative conditions, such as non-fermentable carbon sources or higher concentrations of fermentable sugars. This is obtained for each specific strain. Finally, the calculated kinetic parameters are compared with the threshold values to establish whether the yeast shows fermentative and/or respiratory growth. The advantage of this method is its relative simplicity for understanding the effects of a substance/compound on fermentative or respiratory metabolism. It is important to highlight that growth is an intricate and complex biological process; therefore, preliminary data from this method must be corroborated by the quantification of oxygen consumption and accumulation of fermentation byproducts. Thereby, this technique can be used as a preliminary screening of compounds/substances that may disturb or enhance fermentative or respiratory metabolism.