Embedded Machine Learning System for Muscle Patterns Detection in a Patient with Shoulder Disarticulation.

The integration of artificial intelligence (AI) models in the classification of electromyographic (EMG) signals represents a significant advancement in the design of control systems for prostheses. This study explores the development of a portable system that classifies the electrical activity of three shoulder muscles in real time for actuator control, marking a milestone in the autonomy of prosthetic devices. Utilizing low-power microcontrollers, the system ensures continuous EMG signal recording, enhancing user mobility. Focusing on a case study-a 42-year-old man with left shoulder disarticulation-EMG activity was recorded over two days using a specifically designed electronic board. Data processing was performed using the Edge Impulse platform, renowned for its effectiveness in implementing AI on edge devices. The first day was dedicated to a training session with 150 repetitions spread across 30 trials and three different movements. Based on these data, the second day tested the AI model's ability to classify EMG signals in new movement executions in real time. The results demonstrate the potential of portable AI-based systems for prosthetic control, offering accurate and swift EMG signal classification that enhances prosthetic user functionality and experience. This study not only underscores the feasibility of real-time EMG signal classification but also paves the way for future research on practical applications and improvements in the quality of life for prosthetic users.

Interaction of L-phenylalanine with carbonyl groups in mixed lipid membranes.

The interaction of L-Phe with the membrane components, i.e., lipids and proteins, has been discussed in the current literature due to the interest to understand the effect of single amino acids in relation to the formation of amyloid aggregates. In the present work, it is shown that L-Phe interacts with 9:1 DMPC (1,2-dimyristoyl-sn-glycero-3 phosphocholine)/DPPC (1,2-dipalmitoyl-sn-glycero-3 phosphocholine) mixtures but not in the 1:9 one. An important observation is that the interaction disappears when DPPC is replaced by diether PC (2-di-O-hexadecyl-sn-glycero-3-phosphocholine) a lipid lacking carbonyl groups (CO). This denotes that CO groups may interact specifically with L-Phe in accordance with the appearance of a new peak observed by Infrared spectroscopy (FTIR-ATR). The interaction of L-Phe affects the compressibility pattern of the 9:1 DMPC/DPPC mixture which is congruent with the changes observed by Raman spectra. The specific interaction of L-Phe with CO, propagates to phosphate and choline groups in this particular mixture as analyzed by FTIR-ATR spectroscopy and is absent when DMPC is dopped with diether PC.

Overwhelmed by beauty and faith: review on artistic and religious travelers' syndromes.

Traveling with the intention of encountering art or seeking purification of the spirit involves retribution of intangible nature and therefore can be expected to be a positive experience; nevertheless, among susceptible travelers, there is also a possibility of experiencing pathological conditions. Although it is colloquially known that beauty lies in the eyes of the beholder, it is necessary to mention that the appreciation of beauty, immensity, or mysticism contained in masterpieces is not perceived only through the eyes but through other sense organs as well. Additionally, this is understood within a cultural framework and through previous knowledge. The reaction triggers a series of somatosensory responses of diverse nature, with a wide range of responses that together constitute a pathological phenomenon that can be defined as syndromic by eliciting signs and symptoms of a physical, physiological, and psychotic nature. Both Stendhal and Jerusalem syndromes are travelers' syndromes that may occur in response to objectively aesthetic elements saturated with meaning linked to the cultural heritage of contemporary humanity. While Stendhal syndrome evokes physical and psychoemotional symptoms from the contemplation of art, Jerusalem syndrome goes beyond perception, adding delusions of being a religious or prophetic protagonist pursuing individual or collective salvation.

Association between the Thickness of Lumbar Subcutaneous Fat Tissue and the Presence of Hernias in Adults with Persistent, Non-Traumatic Low Back Pain.

We aimed to analyze the association between the average lumbar subcutaneous fat tissue thickness (LSFTT) at each intervertebral level and the presence of hernias in patients with low back pain from an insurance network hospital in Mexico. This observational prospective study included 174 patients with non-traumatic lumbago who underwent magnetic resonance imaging with a 1.5T resonator. Two independent radiologists made the diagnosis, and a third specialist provided a quality vote when needed. The sample size was calculated with a 95% confidence interval using random order selection. Anonymized secondary information was used. Percentages and means with confidence intervals were tabulated. The area under the curve, specificity, and sensitivity of LSFTT were calculated. A regression analysis was performed to analyze the presence of hernias with LSFTT using each intervertebral level as a predictor. The odds of herniation at any intervertebral level increased directly with LSFTT. The average LSFTT predicted the overall presence of hernias; however, the LSFTT at each intervertebral level better predicted hernias for each intervertebral space. The area under the curve for LSFTT in predicting hernias was 68%. In conclusion, the average LSFTT was associated with the overall presence of hernias; patients with more hernias had higher LSFTT values.

Quantitative EEG analysis in typical absence seizures: unveiling spectral dynamics and entropy patterns.

A typical absence seizure is a generalized epileptic event characterized by a sudden, brief alteration of consciousness that serves as a hallmark for various generalized epilepsy syndromes. Distinguishing between similar interictal and ictal electroencephalographic (EEG) epileptiform patterns poses a challenge. However, quantitative EEG, particularly spectral analysis focused on EEG rhythms, shows potential for differentiation. This study was designed to investigate discernible differences in EEG spectral dynamics and entropy patterns during the pre-ictal and post-ictal periods compared to the interictal state. We analyzed 20 EEG ictal patterns from 11 patients with confirmed typical absence seizures, and assessed recordings made during the pre-ictal, post-ictal, and interictal intervals. Power spectral density (PSD) was used for the quantitative analysis that focused on the delta, theta, alpha, and beta bands. In addition, we measured EEG signal regularity using approximate (ApEn) and multi-scale sample entropy (MSE). Findings demonstrate a significant increase in delta and theta power in the pre-ictal and post-ictal intervals compared to the interictal interval, especially in the posterior brain region. We also observed a notable decrease in entropy in the pre-ictal and post-ictal intervals, with a more pronounced effect in anterior brain regions. These results provide valuable information that can potentially aid in differentiating epileptiform patterns in typical absence seizures. The implications of our findings are promising for precision medicine approaches to epilepsy diagnoses and patient management. In conclusion, our quantitative analysis of EEG data suggests that PSD and entropy measures hold promise as potential biomarkers for distinguishing ictal from interictal epileptiform patterns in patients with confirmed or suspected typical absence seizures.

Interfacial Hyperactivation of Candida rugosa Lipase onto Ca2Fe2O5 Nanoparticles: pH and Ionic Strength Fine-Tuning to Modulate Protein-Support Interactions.

The current study provides a comprehensive look of the adsorption process of Candida rugosa lipase (CRL) on Ca2Fe2O5 iron oxide nanoparticles (NPs). Protein-support interactions were identified across a broad range of pH and ionic strengths (mM) through a response surface methodology, surface charge determination, and spectroscopic and in silico analyses. The maximum quantity of immobilized protein was achieved at an ionic strength of 50 mM and pH 4. However, this condition did not allow for the greatest hydrolytic activity to be obtained. Indeed, it was recorded at acidic pH, but at 150 mM, where evaluation of the recovered activity revealed hyperactivation of the enzyme. These findings were supported by adsorption isotherms performed under different conditions. Based on zeta potential measurements, electrostatic interactions contributed differently to protein-support binding under the conditions tested, showing a strong correlation with experimentally determined immobilization parameters. Raman spectra revealed an increase in hydrophobicity around tryptophan residues, whereas the enzyme immobilization significantly reduced the phenylalanine signal in CRL. This suggests that this residue was involved in the interaction with Ca2Fe2O2 and molecular docking analysis confirmed these findings. Fluorescence spectroscopy showed distinct behaviors in the CRL emission patterns with the addition of Ca2Fe2O5 at pH 4 and 7. The calculated thermodynamic parameters indicated that the contact would be mediated by hydrophobic interactions at both pHs, as well as by ionic ones at pH 4. In this approach, this work adds to our understanding of the design of biocatalysts immobilized in iron oxide NPs.

Correction: Pérez et al. Use of Nanotechnology to Mitigate Biofouling in Stainless Steel Devices Used in Food Processing, Healthcare, and Marine Environments. Toxics 2022, 10, 35.

The authors would like to make corrections to their published paper [...].

Use of Nanotechnology to Mitigate Biofouling in Stainless Steel Devices Used in Food Processing, Healthcare, and Marine Environments.

In humid environments, the formation of biofilms and microfouling are known to be the detrimental processes that first occur on stainless steel surfaces. This is known as biofouling. Subsequently, the conditions created by metabolites and the activity of organisms trigger corrosion of the metal and accelerate corrosion locally, causing a deterioration in, and alterations to, the performance of devices made of stainless steel. The microorganisms which thus affect stainless steel are mainly algae and bacteria. Within the macroorganisms that then damage the steel, mollusks and crustaceans are the most commonly observed. The aim of this review was to identify the mechanisms involved in biofouling on stainless steel and to evaluate the research done on preventing or mitigating this problem using nanotechnology in humid environments in three areas of human activity: food manufacturing, the implantation of medical devices, and infrastructure in marine settings. Of these protective processes that modify the steel surfaces, three approaches were examined: the use of inorganic nanoparticles; the use of polymeric coatings; and, finally, the generation of nanotextures.

Type 1 diabetes affects the brain functional connectivity underlying working memory processing.

Visuospatial working memory (VSWM) deficits have been demonstrated to occur during the development of type-1-diabetes (T1D). Despite confirming the early appearance of distinct task-related brain activation patterns in T1D patients compared to healthy controls, the effect of VSWM load on functional brain connectivity during task performance is still unknown. Using electroencephalographic methods, the present study evaluated this topic in clinically well-controlled T1D young patients and healthy individuals, while they performed a VSWM task with different memory load levels during two main VSWM processing phases: encoding and maintenance. The results showed a significantly lower number of correct responses and longer reaction times in T1D while performing the task. Besides, higher and progressively increasing functional connectivity indices were found for T1D patients in response to cumulative degrees of VSWM load, from the beginning of the VSWM encoding phase, without notably affecting the VSWM maintenance phase. In contrast, healthy controls managed to solve the task, showing lower functional brain connectivity during the initial VSWM processing steps with more gradual task-related adjustments. Present results suggest that T1D patients anticipate high VSWM load demands by early recruiting supplementary processing resources as the probable expression of a more inefficient, though paradoxically better adjusted to task demands cognitive strategy.

Multilayer Network Approach in EEG Motor Imagery with an Adaptive Threshold.

The brain has been understood as an interconnected neural network generally modeled as a graph to outline the functional topology and dynamics of brain processes. Classic graph modeling is based on single-layer models that constrain the traits conveyed to trace brain topologies. Multilayer modeling, in contrast, makes it possible to build whole-brain models by integrating features of various kinds. The aim of this work was to analyze EEG dynamics studies while gathering motor imagery data through single-layer and multilayer network modeling. The motor imagery database used consists of 18 EEG recordings of four motor imagery tasks: left hand, right hand, feet, and tongue. Brain connectivity was estimated by calculating the coherence adjacency matrices from each electrophysiological band (δ, θ, α and ß) from brain areas and then embedding them by considering each band as a single-layer graph and a layer of the multilayer brain models. Constructing a reliable multilayer network topology requires a threshold that distinguishes effective connections from spurious ones. For this reason, two thresholds were implemented, the classic fixed (average) one and Otsu's version. The latter is a new proposal for an adaptive threshold that offers reliable insight into brain topology and dynamics. Findings from the brain network models suggest that frontal and parietal brain regions are involved in motor imagery tasks.

Incidence of post-anesthetic respiratory complications in pediatrics. Observational, single-center study in Medellin, Colombia / Incidencia de complicaciones respiratorias postanestésicas en pacientes pediátricos. Estudio observacional en un hospital en Medellín, Colombia

Abstract Introduction: Post-anesthetic complications, particularly respiratory complications, continue to be a source of concern due to their high frequency, particularly in pediatrics. Objective: To describe the incidence of respiratory complications in the post-anesthesia care unit of an intermediate complexity center during a six-month period, and to explore the variables associated with major respiratory complications. Materials and Methods: Retrospective cohort study based on clinical record reviews. The records of the post-anesthesia care unit of an intermediate complexity pediatric institution located in Medellin, Colombia, were reviewed. This center uses a nursing-based care model that includes patient extubation in the post-anesthesia care unit. Results: The records of 1181 patients were analyzed. The cumulative incidences of major complications were bronchospasm 1.44%, laryngospasm 0.68% and respiratory depression 0.59%. There were no cases of cardiac arrest or acute pulmonary edema. A history of respiratory infection less than 15 days before the procedure, rhinitis and female sex were associated with major respiratory complications. Conclusions: A low frequency of respiratory complications was found during care provided by nursing staff trained in anesthesia recovery and pediatric airway in the post-anesthesia care unit.

Resumen Introducción: Las complicaciones postanestésicas, especialmente las respiratorias, siguen siendo causa de preocupación por su alta frecuencia, en particular, en la población pediátrica. Objetivo: Describir la incidencia de complicaciones respiratorias en la unidad de cuidados postanestésicos de una institución de mediana complejidad, en un período de seis meses y explorar las variables relacionadas con las complicaciones respiratorias mayores. Materiales y métodos: Estudio de cohorte retrospectivo, basado en la valoración de historias clínicas. Se revisaron los registros de la unidad de cuidados postanestésicos de una institución pediátrica de mediana complejidad ubicada en Medellín. Esta institución utiliza un modelo de atención -basado en enfermería- que incluye la extubación del paciente en la unidad de cuidados postanestésicos. Resultados: Se analizaron los registros de 1181 pacientes. La incidencia acumulada de complicaciones mayores fue: broncoespasmo 1,44 %, laringoespasmo 0,68 % y depresión respiratoria 0,59 %. No se presentaron casos de paro cardiaco ni de edema agudo de pulmón. El antecedente de infección respiratoria menor a 15 días, rinitis y sexo femenino se asociaron con complicaciones respiratorias mayores. Conclusiones: Durante la atención en la unidad de cuidados postanestésicos por parte del personal de enfermería entrenado en la recuperación de la anestesia y de la vía aérea de los pacientes pediátricos, se encontró una baja frecuencia de complicaciones respiratorias.

Frequency spectra characterization of noncoding human genomic sequences.

BACKGROUND: Noncoding sequences have been demonstrated to possess regulatory functions. Its classification is challenging because they do not show well-defined nucleotide patterns that can correlate with their biological functions. Genomic signal processing techniques like Fourier transform have been employed to characterize coding and noncoding sequences. This transformation in a systematic whole-genome noncoding library, such as the ENCODE database, can provide evidence of a periodic behaviour in the noncoding sequences that correlates with their regulatory functions. OBJECTIVE: The objective of this study was to classify different noncoding regulatory regions through their frequency spectra. METHODS: We computed machine learning algorithms to classify the noncoding regulatory sequences frequency spectra. RESULTS: The sequences from different regulatory regions, cell lines, and chromosomes possessed distinct frequency spectra, and that machine learning classifiers (such as those of the support vector machine type) could successfully discriminate among regulatory regions, thus correlating the frequency spectra with their biological functions CONCLUSION: Our work supports the idea that there are patterns in the noncoding sequences of the genome.

Effects of Three Herbs on Methane Emissions from Beef Cattle.

The objectives of the present work were to evaluate the in vivo antimethanogenic effects of Cymbopogon citratus (CC), Matricaria chamomilla (MC) and Cosmos bipinnatus (CB) on beef cattle fed a high in concentrate diet (forage-to-concentrate ratio [F:C] of 19.4:80.6), and the effects of increasing levels of CC (0%, 2%, 3%, and 4% of the daily DM intake (DMI)) on enteric CH4 emissions by beef cattle fed a ration low in concentrate (F:C ratio of 49.3:50.7). Two experiments were conducted to address the objectives. For the first experiment, eight Charolais × Brown Swiss steers distributed in a replicated 4 × 4 Latin square experimental design were used. Four treatments were evaluated: (1) control diet (CO), (2) CO + 365 g dry matter (DM)/d CB, (3) CO + 365 g DM/d MC, (4) CO + 100 g DM/d CC. For Experiment 2, four Charolais x Brown Swiss steers distributed in a single 4 × 4 Latin square design were used. It was concluded that 100 g DM per day CC and 365 g DM per day CB (Experiment 1) reduced CH4 yield of beef cattle. In Experiment 2, CC supplementation levels exceeding 2% of DMI reduced daily CH4 emissions but at the expense of decreasing digestibility of DM.

Whole-Genome k-mer Topic Modeling AssociatesBacterial Families.

Alignment-free k-mer-based algorithms in whole genome sequence comparisons remainan ongoing challenge. Here, we explore the possibility to use Topic Modeling for organismwhole-genome comparisons. We analyzed 30 complete genomes from three bacterial families bytopic modeling. For this, each genome was considered as a document and 13-mer nucleotiderepresentations as words. Latent Dirichlet allocation was used as the probabilistic modeling of thecorpus. We where able to identify the topic distribution among analyzed genomes, which is highlyconsistent with traditional hierarchical classification. It is possible that topic modeling may be appliedto establish relationships between genome's composition and biological phenomena.

Construction and Operation of a Respiration Chamber of the Head-Box Type for Methane Measurement from Cattle.

This paper aims to describe the construction and operation of a respiration chamber of the head-box type for methane (CH4) measurements in bovines. The system consists of (1) a head box with a stainless steel frame and acrylic walls, floor, and ceiling; (2) a stainless steel feeder; (3) an automatic drinking water bowl; (4) a hood made from reinforced canvas; (5) an infrared (IR) CH4 gas analyzer, a mass flow generator, a data-acquisition system; and (6) a steel metabolic box. Six assays were conducted to determine the pure CH4 recovery rate of the whole system in order to validate it and comply with standards of chamber operation. The gravimetrical method was used for the recovery test and the recovery rate obtained was 1.04 ± 0.05. Once the system was calibrated, measurements of CH4 were conducted using eight animals consisting of four Holstein cows with a live weight of 593.8 ± 51 kg and an average milk yield of 23.3 ± 1.8 kg d-1 and four heifers with a live weight of 339 ± 28 kg. The CH4 production values were 687 ± 123 and 248 ± 40 L CH4 d-1 for cows and heifers, respectively. The CH4 yield was 19.7 ± 3.4 g and 17.1 ± 3.4 g CH4 kg-1 of dry matter consumed for cows and heifers, respectively. These results are consistent with those reported in the literature.

Type-1 diabetes shapes working memory processing strategies.

BACKGROUND: Type 1 diabetes (T1D) is a metabolic disorder characterized by recurrent hypo- and hyperglycemic episodes, whose clinical development has been associated with cognitive and working memory (WM) deficits. OBJECTIVE: To contrast quantitative electroencephalography (qEEG) measures between young patients with T1D and healthy controls while performing a visuospatial WM task with two memory load levels and facial emotional stimuli. METHODS: Four or five neutral or happy faces were sequentially and pseudo-randomly presented in different spatial locations, followed by subsequent sequences displaying the reversed spatial order or any other. Participants were instructed to discriminate between these two alternatives during EEG recording. RESULTS: A significant increase in the absolute power of the delta and theta bands, distributed mainly over the frontal region was found during task execution, with a slight decrease of alpha band power in both groups but mainly in control individuals. However, these changes were more pronounced in the T1D patients, and reached their maximum level during the WM encoding phase, even on trials with the lower memory load. In contrast, changes seemed to occur more gradually in controls and results differed significantly only on the trials with the higher WM load. CONCLUSIONS: These results reflect adaptive WM-processing mechanisms in which cognitive strategies have evolved in T1D patients in order to meet task demands.

A step forward in the quest for a mobile EEG-designed epoch for psychophysiological studies.

The aim of this study was to compare a reconfigurable mobile electroencephalography (EEG) system (M-EMOTIV) based on the Emotiv Epoc® (which has the ability to record up to 14 electrode sites in the 10/20 International System) and a commercial, clinical-grade EEG system (Neuronic MEDICID-05®), and then validate the rationale and accuracy of recordings obtained with the prototype proposed. In this approach, an Emotiv Epoc® was modified to enable it to record in the parieto-central area. All subjects (15 healthy individuals) performed a visual oddball task while connected to both devices to obtain electrophysiological data and behavioral responses for comparative analysis. A Pearson's correlation analysis revealed a good between-devices correlation with respect to electrophysiological measures. The present study not only corroborates previous reports on the ability of the Emotiv Epoc® to suitably record EEG data but presents an alternative device that allows the study of a wide range of psychophysiological experiments with simultaneous behavioral and mobile EEG recordings.

Effect of cholesterol on the surface polarity and hydration of lipid interphases as measured by Laurdan fluorescence: New insights.

Comparison of the behavior of Laurdan in gel and in the liquid crystalline DPPC bilayers with that observed in chloroform and OctOH allow concluding that changes in the membrane lipid order cannot be ascribed to changes in viscosity of the local environment. Cholesterol acts as a spacer below the transition temperature of DPPC, promoting a disorder state in the acyl chain region. No evidence of water entrance has been detected with Laurdan up to 30% Cholesterol in DPPC in this condition. In contrast, Chol displaces to longer values the wavelength of Laurdan in membranes in the liquid crystalline state. This decrease in polarity occurs above 5% Chol and is directly related to the water extrusion produced by Chol. This effect is similar to that occurring in liquid crystalline membranes subjected to hypertonic stress. The behavior is comparable to that of Laurdan in OctOH at different water ratios below 5% Chol/DPPC. At higher ratios, other changes are evident.

Evaluación de dos fórmulas de yogur enriquecido con harina de Acheta domesticus y harina de Brosimum alicastrum Swartz como alimentos complementarios / Evaluation of two formulas of yogurt enriched with Acheta domesticus flour and Brosimum alicastrum flour, as complementary foods

La prevalencia de desnutrición en niños en Guatemala es constante y se ha mantenido alta por años. Tomando en cuenta esta problemática se planteó un modelo de alimentación complementaria a base de yogur enriquecido con harinas de alto valor proteico en niños de edad preescolar en el suroccidente de Guatemala. Los tratamientos evaluados fueron yogur con harina de Acheta domesticus (grillo), yogur con harina de Brosimum alicastrum Swartz (ramón) y un grupo control. Se evaluó el peso, talla y velocidad de crecimiento durante cuatro meses brindando 125 mL de yogur cinco días por semana. La ganancia media (desviación estándar) de peso en kg fue de 3.21 (1.84), 2.22 (1.14) y 1.67 (0.64) para A. domesticus, B. alicastrum y grupo control, respectivamente. Mostrando la mezcla de yogur con harina de A. domesticus diferencia significativa frente al control (p < .05), por el contrario, no se encontró diferencia significativa (p > .05) cuando se comparó con yogur con harina de B. alicastrum. Para el incremento en talla en cm los resultados fueron 4.61 (1.13), 4.25 (1.54) y 3.07 (1.84) para A. domesticus, B. alicastrum y grupo control, respectivamente, mostrando ambas diferencias significativas frente al control (p < .05). Se determinaron los costos por dosis los cuales fueron US$0.56 (A. domesticus) y US$0.36 (B. alicastrum). Se concluye que el yogur con harina de A. domesticus fue el que presentó mejor respuesta en las variables de estudio.

The prevalence data on malnutrition of children in Guatemala are constant. Taking into account this problem, a yogurt-based supplementary feeding model was proposed, enriched with high-protein flours in pre-school children in southwestern Guatemala. The treatments evaluated were yogurt with Acheta domesticus flour (cricket), yogurt with Brosimum alicastrum Swartz flour (ramon) and control group. The weight, height and growth rate were evaluated during four months providing 125 mL of yogurt five days per week. The weight gain in kg was 3.21 (1.84), 2.22 (1.14) and 1.67 (0.64) for A. domesticus, B. alicastrum and control group respectively, showing significant difference (p < .05). The costs per dose were determined, which were US $ 0.56 (A. domesticus) and US $ 0.36 (B. alicastrum). The study concludes that yogurt with A. domesticus flour was the one that presented the best response in the study variables.

Effects of Lysozyme on the Activity of Ionic of Fluoroquinolone Species.

Fluoroquinolones (FQs) constitute an important class of biologically active broad-spectrum antibacterial drugs that are which are in contact with many biological fluids under different acidity conditions. We studied the reactivity of ciprofloxacin (Cpx) and levofloxacin (Lev) and their interaction with lysozyme (Lyz) at different pH values, using UV-visible absorption, fluorescence, infrared spectroscopies supported by DFT calculation and docking. In addition, by antimicrobial assays, the biological consequences of the interaction were evaluated. DFT calculation predicted that the FQ cationic species present at acid pH have lower stabilization energies, with an electric charge rearrangement because of their interactions with solvent molecules. NBO and frontier orbital calculations evidenced the role of two charged centers, NH2⁺ and COO-, for interactions by electronic delocalization effects. Both FQs bind to Lyz via a static quenching with a higher interaction in neutral medium. The interaction induces a structural rearrangement in ß-sheet content while in basic pH a protective effect against the denaturation of Lyz was inferred. The analysis of thermodynamic parameters and docking showed that hydrophobic, electrostatic forces and hydrogen bond are the responsible of Cpx-Lyz and Lev-Lyz associations. Antimicrobial assays evidenced an antagonist effect of Lyz in acid medium while in neutral medium the FQs' activities were not modified by Lyz.