Volatile Semiochemicals Emitted by Beauveria bassiana Modulate Larval Feeding Behavior and Food Choice Preference in Spodoptera frugiperda (Lepidoptera: Noctuidae).

Beauveria bassiana is an entomopathogenic fungus that parasitizes and kills insects. The role of volatile organic compounds (VOCs) emitted by B. bassiana acting as semiochemicals during its interaction with lepidopterans is poorly explored. Here, we studied the effect of VOCs from B. bassiana and 3-methylbutanol (as a single compound) on the feeding behavior of L2 larvae of Spodoptera frugiperda in sorghum plants. Additionally, we assessed whether fungal VOCs induce chemical modifications in the plants that affect larval food preferences. Metabolomic profiling of plant tissues was performed by mass spectrometry and bioassays in a dual-choice olfactometer. The results showed that the larval feeding behavior was affected by the B. bassiana strain AI2, showing that the insect response is strain-specific. Furthermore, 80 µg of 3-methylbutanol affected the number of bites. The larval feeding choice was dependent on the background context. Fragment spectra and a matching precursor ion mass of 165.882 m/z enabled the putative identification of 4-coumaric acid in sorghum leaves exposed to fungal VOCs, which may be associated with larval deterrent responses. These results provide valuable insights into the bipartite interaction of B. bassiana with lepidopterans through VOC emission, with the plant as a mediator of the interaction.

Effect of pH on metabolic pathway shift in fermentation and electro-fermentation of xylose by Clostridium autoethanogenum.

Clostridium autoethanogenum can to convert waste gases (CO2, CO, H2) and xylose from hydrolyzed biomass into acetate, lactate, formate, ethanol and 2,3-butanediol, being a candidate for the transformation of waste streams of lignocellulosic biorefineries. Electro-fermentation (EF) modify the pattern of traditional fermentations resulting in improved product yields as has been shown when using Clostridium strains. The aim of this work was to evaluate the influence of pH on microbial growth and product distribution during fermentation and EF of xylose by C. autoethanogenum DSM10061. Fermentation and EF were carried out in a H-type reactor at three controlled pH: 5.0, 5.5 and 5.8, and at a fixed potential of -600 mV (versus Ag/AgCl) in the EF. The experiments showed that maximum biomass concentration increased as the pH increased in fermentation and EF. In accordance with maximum biomass reached, the highest substrate conversion was observed at pH 5.8 for both systems, with 76.80 % in fermentation and 96.18 % in EF. Moreover, the highest concentrations of acetic acid (1.41 ± 0.07 g L-1) and ethanol (1.45 ± 0.15 g L-1) were obtained at the end of cultures in the EF at pH 5.8. The production of lactic and formic acid decreased by the application of the external potential regardless of the pH value, reaching the lowest productivity at pH 5.8. In contrast, the specific productivity of acetic acid and ethanol was lower in both fermentation and EF at the lowest pH. Furthermore, the presence of 0.06 g L-1 of 2,3-butanediol was only detected in EF at pH 5.8. The results revealed that EF modulated microbial metabolism, which can be explained by a possible increased generation of NADP+/NADPH cofactors, which would redirect the metabolic pathway to more reduced products.

A Community Survey on Association of Sociodemographic Characteristics with Risk Perception and Awareness about Oral Cancer in Lagos, Nigeria

ABSTRACT Objective: To assess the level of oral cancer awareness and risk factors perception and the relationship between this awareness and the sociodemographic and behavioral characteristics. Material and Methods: This descriptive study was conducted among rural and urban residents in Lagos State, Nigeria. A multi-stage random sampling method was utilized. The sociodemographic and behavioral characteristics of respondents, as well as their knowledge about oral cancer risk factors, were assessed with a validated questionnaire. The bivariate association was done using an independent t-test and one-way ANOVA. Multivariate regression was used to determine the association between predictor variables and oral cancer knowledge scores. The statistical significance level is set at p<0.05. Results: 590 participants between 18 and 82 years (mean age 34.5 ±13.7) completed the survey. The prevalence of cigarette smoking was 25.7%, of which 16 (1.5%) were heavy smokers (20+ cigarettes per day). The prevalence of alcohol consumption was 66.1%, with 57 (9.7%) being heavy drinkers, consuming drinks for 5-7 days of the week. A high proportion of the respondents (>60%) exhibited gaps in their knowledge of oral cancer. Uneducated participants had lower oral cancer knowledge than those with >12 years of formal education (aOR = 5.347; 95% CI: 4.987-6.240). Participants who were smokers had lower oral cancer knowledge compared with non-smokers (aOR = 3.341; 95% CI: 2.147-4.783); Participants who consumed alcohol had more deficient oral cancer knowledge compared with non-drinkers (aOR = 1.699; 95% CI: 1.087-2.655); While heavy smokers aOR = 4.023; 95% CI: 3.615-4.825) and heavy drinkers aOR = 4.331; 95% CI: 3.158-5.939) had lower oral cancer knowledge compared with those who did not abuse both substances. Conclusion: A high proportion of the respondents exhibited gaps in their knowledge of oral cancer in their responses. Delayed diagnosis of oral cancer can be reduced by increasing the awareness and knowledge of the populace about risk factors and also in the recognition of its signs and symptoms.

Antimicrobial Effect of Low-Fluoride Toothpastes Containing Polyphosphate and Polyols: An In Vitro Assessment of Inhibition Zones.

This study evaluated the antimicrobial effect of toothpastes containing 200 ppm fluoride (200F), xylitol (X, 16%), erythritol (E, 4%), and sodium trimetaphosphate (TMP, 0.25%), alone or in different associations, against Streptococcus mutans (SM), Lactobacillus casei (LC), Actinomyces israelii (AI), and Candida albicans (CA). Suspensions of the micro-organisms were added to a BHI Agar medium. Five wells were made on each plate to receive toothpaste suspensions at different dilutions. Toothpastes containing no actives (placebo) or 1100 ppm F (1100F) were used as negative and positive controls. Two-way ANOVA and Tukey's HDS test were used (p < 0.05). For SM, the largest halo was for 200F+TMP at all dilutions, followed by the 200F+X+E toothpaste (p < 0.001). For LC, the overall trend showed that the polyols effectively inhibited microbial growth, and the association with the other compounds enhanced such effects (p < 0.001). For AI, a less-defined trend was observed. For CA, the experimental toothpaste (200F+X+E+TMP) was consistently more effective than the other treatments, followed by 200F+X+E (p < 0.001). The association of polyols and TMP in a low-fluoride toothpaste effectively reduced the growth of cariogenic micro-organisms (SM, CA, and LC), suggesting that this formulation could be an interesting alternative for children due to its low fluoride content.

Evaluation of Solutions Containing Fluoride, Sodium Trimetaphosphate, Xylitol, and Erythritol, Alone or in Different Associations, on Dual-Species Biofilms.

Although the association of polyols/polyphosphates/fluoride has been demonstrated to promote remarkable effects on dental enamel, little is known on their combined effects on biofilms. This study assessed the effects of solutions containing fluoride/sodium trimetaphosphate (TMP)/xylitol/erythritol on dual-species biofilms of Streptococcus mutans and Candida albicans. Biofilms were grown in the continuous presence of these actives alone or in different associations. Quantification of viable plate counts, metabolic activity, biofilm biomass, and extracellular matrix components were evaluated. Overall, fluoride and TMP were the main actives that significantly influenced most of the variables analyzed, with a synergistic effect between them for S. mutans CFUs, biofilm biomass, and protein content of the extracellular matrix (p < 0.05). A similar trend was observed for biofilm metabolic activity and carbohydrate concentrations of the extracellular matrix, although without statistical significance. Regarding the polyols, despite their modest effects on most of the parameters analyzed when administered alone, their co-administration with fluoride and TMP led to a greater reduction in S. mutans CFUs and biofilm biomass compared with fluoride alone at the same concentration. It can be concluded that fluoride and TMP act synergistically on important biofilm parameters, and their co-administration with xylitol/erythritol significantly impacts S. mutans CFUs and biomass reduction.

The use of contraceptives and their nutritional impact on medical students

SUMMARY OBJECTIVE: This study aimed to analyze the impact of contraceptives on medical students at the Federal University of Paraná and verify adherence, consequences, and lifestyle effects of the contraceptive method used. METHODS: This is an observational, cross-sectional study in which 214 participants answered an online questionnaire composed of 30 questions. For statistical analysis, the Stata® 16.0 software was used, and the mean and standard deviation were estimated to characterize continuous variables with a normal distribution and percentages for categorical variables. For group-to-group comparisons, a one-way ANOVA was used for normal continuous variables and Fisher's exact test for categorical variables. RESULTS: Almost 10% (9.3%) of women used condoms only, and double protection (condom+oral contraceptives) corresponds to 23.4%. Of the 214 participants, 38 reported making exclusive use of long-acting reversible contraception, and 13.6% of the interviewees used oral contraceptives exclusively. More than 88% of the interviewees believe that the medical course provided adequate education on contraception. Regarding lifestyle habits, 71.5% of the students reported alcohol intake, tobacco use, and/or other drug use. CONCLUSION: There was a great diversity of combinations between contraceptive methods used by the medical student at Federal University of Paraná, the most prevalent being the oral contraceptive associated with male condoms. There was a greater association in the use of long-acting reversible contraception in married students. Although 88.3% of the participants believed that they had a good education about contraception at university, only half of them use condoms in sexual relationships. The rate of adherence to alcohol and tobacco among students is considerable, and such practices can negatively affect a nutritional profile, a healthy lifestyle, and safe sexual practices. Brazilian medical schools are fundamental for the advancement of medical education in contraception and for the creation of public policies on family planning.

Biocatalytic asymmetric synthesis of secondary allylic alcohols using Burkholderia cepacia lipase immobilized on multiwalled carbon nanotubes.

The lipase from Burkholderia cepacia (BCL) was immobilized through physical adsorption on pristine and functionalized multiwalled carbon nanotubes (MWCNTs) with carboxyl or amine groups and used in the stereoselective acylation of (R,S)-1-octen-3-ol (1) and (R,S)-(E)-4-phenyl-3-buten-2-ol (4) with vinyl acetate. All immobilized preparations produced better results than free BCL. For (R,S)-4, 50% conversion and E > 200 were obtained in n-hexane or in solvent-free medium. For (R,S)-1, in solvent-free medium, the conversion was 38% with a slight increase in the E-value (E = 10).

Structural Determinants of Sugar Alcohol Biosynthesis in Plants: The Crystal Structures of Mannose-6-Phosphate and Aldose-6-Phosphate Reductases.

Sugar alcohols are major photosynthetic products in plant species from the Apiaceae and Plantaginaceae families. Mannose-6-phosphate reductase (Man6PRase) and aldose-6-phosphate reductase (Ald6PRase) are key enzymes for synthesizing mannitol and glucitol in celery (Apium graveolens) and peach (Prunus persica), respectively. In this work, we report the first crystal structures of dimeric plant aldo/keto reductases (AKRs), celery Man6PRase (solved in the presence of mannonic acid and NADP+) and peach Ald6PRase (obtained in the apo form). Both structures displayed the typical TIM barrel folding commonly observed in proteins from the AKR superfamily. Analysis of the Man6PRase holo form showed that residues putatively involved in the catalytic mechanism are located close to the nicotinamide ring of NADP+, where the hydride transfer to the sugar phosphate should take place. Additionally, we found that Lys48 is important for the binding of the sugar phosphate. Interestingly, the Man6PRase K48A mutant had a lower catalytic efficiency with mannose-6-phosphate but a higher catalytic efficiency with mannose than the wild type. Overall, our work sheds light on the structure-function relationships of important enzymes to synthesize sugar alcohols in plants.

Valorization of the baru (Dipteryx alata Vog.) processing chain: Technological properties of defatted nut flour and oil solubility in ethanol and isopropanol.

Baru, a Brazilian Cerrado native fruit, stands out for its high nutritional value. Considering that reports about its technological potential are scant, this study aimed to add value to the processing chain. For that, ethanol and isopropanol were evaluated in terms of their suitability to solubilize baru nut oil (BNO), extract baru nut cake oil (BNCO), and obtain a protein-rich defatted flour. The BNO solubility in alcohols was adequately described by nonrandom two-liquid (NRTL) parameters, and the highest solubilization capacity was achieved with absolute isopropanol. Alcoholic extraction did not affect the BNCO tocopherol content (80-112 mg/kg oil) or its fatty acid composition. Both protein solubility and thermal stability were negatively affected by solvent hydration, temperature, and contact stages. However, the materials exhibited adequate water and oil absorption capacities (3.5 and 1 g/g sample), as well as improved foaming capacity and stability, confirming their potential for use in several food formulations.

Escherichia coli coculture for de novo production of esters derived of methyl-branched alcohols and multi-methyl branched fatty acids.

BACKGROUND: A broad diversity of natural and non-natural esters have now been made in bacteria, and in other microorganisms, as a result of original metabolic engineering approaches. However, the fact that the properties of these molecules, and therefore their applications, are largely defined by the structural features of the fatty acid and alcohol moieties, has driven a persistent interest in generating novel structures of these chemicals. RESULTS: In this research, we engineered Escherichia coli to synthesize de novo esters composed of multi-methyl-branched-chain fatty acids and short branched-chain alcohols (BCA), from glucose and propionate. A coculture engineering strategy was developed to avoid metabolic burden generated by the reconstitution of long heterologous biosynthetic pathways. The cocultures were composed of two independently optimized E. coli strains, one dedicated to efficiently achieve the biosynthesis and release of the BCA, and the other to synthesize the multi methyl-branched fatty acid and the corresponding multi-methyl-branched esters (MBE) as the final products. Response surface methodology, a cost-efficient multivariate statistical technique, was used to empirical model the BCA-derived MBE production landscape of the coculture and to optimize its productivity. Compared with the monoculture strategy, the utilization of the designed coculture improved the BCA-derived MBE production in 45%. Finally, the coculture was scaled up in a high-cell density fed-batch fermentation in a 2 L bioreactor by fine-tuning the inoculation ratio between the two engineered E. coli strains. CONCLUSION: Previous work revealed that esters containing multiple methyl branches in their molecule present favorable physicochemical properties which are superior to those of linear esters. Here, we have successfully engineered an E. coli strain to broaden the diversity of these molecules by incorporating methyl branches also in the alcohol moiety. The limited production of these esters by a monoculture was considerable improved by a design of a coculture system and its optimization using response surface methodology. The possibility to scale-up this process was confirmed in high-cell density fed-batch fermentations.

A green chemistry approach for oxidation of alcohols using novel bioactive cobalt composite immobilized on polysulfone fibrous network nanoparticles as a catalyst.

In this study, cobalt composite immobilized on polysulfone fibrous network nanoparticles (CCPSF NPs) were synthesized in a controllable and one-step way under microwave-assisted conditions. The structure of CCPSF NPs was characterized by SEM images (for morphology and size distribution), TGA (for thermal stability), BET technique (for the specific surface area), FT-IR spectroscopy (for relation group characterization), and XRD patterns (for crystal size). The oxidation of the primary and secondary alcohols to aldehyde and ketone was investigated using synthesized CCPSF NPs under solvent-free microwave-assisted conditions, and high oxidizing activity was observed. In addition to oxidation properties, the anticancer activity of the synthesized CCPSF NPs in breast cancer was evaluated by the MTT method , and significant results were obtained.

Effect of Age of Agave tequilana Weber Blue Variety on Quality and Authenticity Parameters for the Tequila 100% Agave Silver Class: Evaluation at the Industrial Scale Level.

Due to the oversupply and scarcity cycles of the Agave tequilana Weber blue variety, the effect of agave age (harvested in 4, 5, and 6 years) as raw material for the tequila 100% agave silver class was studied for each stage in a full-scale (industrial) process. Harvested plants showed differences in their morphological characteristics that affected the amount of juice; this had an impact in the fermentation stage since must composition was modified in the nitrogen content and juice/exudate ratio. This was noticed due to an increase in the production of higher alcohols attributed to the odd-chain fatty of the exudate, which affects n-propanol production. The characterization of the final product showed the feasibility to use agaves (less than 7 years) to produce the Tequila 100% agave silver class and to comply with the quality criteria. Furthermore, the final product was analyzed with the gas chromatography-isotope ratio mass-spectrometry technique to determine its authenticity. The δ13CVPDB isotopic parameter (-13.40‱ in average) values show the type of plant used as a raw material for ethanol production, while the δ18OVSMOW (20.52‱ in average) isotopic parameter can be helpful in corroborating and ensuring the traceability of the product and the geographical location of the beverage production.

Antimicrobial potential of essential oils mouthrinses with and without alcohol: a randomized clinical trial

Aim: This study aimed to compare the microbiological potential and gustatory perception of essential oils (EO) mouthrinses containing and not containing alcohol. Methods: Twenty healthy adult volunteers rinsed with 10mL of the following test solutions: EO with alcohol, EO without alcohol, or a control solution (saline solution with mint essence). A washout period of at least seven days was adopted after a single-use protocol of the respective solution. All participants used all three tested substances. Antimicrobial potential was assessed by counting salivary total viable bacteria both before and after each rinse. Gustatory perception was evaluated using the Visual Analogue Scale (VAS). Multiple comparisons were performed with the Wilcoxon test, using Bonferroni correction. Results: Both EO solutions presented a higher antimicrobial potential in comparison to the control solution (p<0.017). However, no significant difference in antimicrobial potential was observed between EO containing or not containing alcohol (p=0.218). VAS of EO with alcohol (median: 2.7) was similar to control solution (median: 1.6) (p=0.287). A better gustatory perception was observed of the EO without alcohol (median 7.6) when compared to the control solution (p<0.0001). When EO groups were compared, EO without alcohol also demonstrated a significantly better gustatory perception (p=0.001). Conclusion: Mouthrinse containing EO without alcohol presented a better taste perception when compared to the EO with alcohol, but no difference was observed in the antimicrobial potential of both EO solutions after a single rinse protocol

Synthesis and interaction of terminal unsaturated chemical probes with Mycobacterium tuberculosis CYP124A1.

A series of C15-C20 isoprenyl derivatives bearing terminal alkenyl and alkynyl groups were synthesized as possible substrates of the methyl-branched lipid ω-hydroxylase CYP124A1 from Mycobacterium tuberculosis. The interactions of each compound with the enzyme active site were characterized using UV-vis spectroscopy. We found that C10 and C15 analogs bind with similar affinity to the corresponding parent C10 and C15 substrates geraniol and farnesol, respectively. Three analogs (C10-ω-ene, C10-ω-yne, C15-ω-yne) interact with the proximal side of the heme iron by coordinating to the oxygen atom of the ferric heme, as judged by the appearance of typical Type-IA binding spectra. On the other hand, the C15-ω-ene analog interacts with the ferric heme by displacing the bound water that generates a typical Type I binding spectrum. We were unable to detect P450-mediated oxidation of these probes following extended incubations with CYP124A1 in our reconstituted assay system, whereas a control reaction containing farnesol was converted to ω-hydroxy farnesol under the same conditions. To understand the lack of detectable oxidation, we explored the possibility that the analogs were acting as mechanism-based inhibitors, but we were unable to detect time-dependent loss of enzymatic activity. In order to gain insight into the lack of detectable turnover or time-dependent inhibition, we examined the interaction of each compound with the CYP124A1 active site using molecular docking simulations. The docking studies revealed a binding mode where the terminal unsaturated functional groups were sequestered within the methyl-binding pocket, rather than positioned close to the heme iron for oxidation. These results aid in the design of specific inhibitors of Mtb-CYP124A1, an interesting enzyme that is implicated in the oxidation of methyl-branched lipids, including cholesterol, within a deadly human pathogen.

Effect of the acyl-group length on the chemoselectivity of the lipase-catalyzed acylation of propranolol-a computational study.

The selective N-acylation of 1,2-amino alcohols has been proposed to occur through the proton shuttle mechanism. However, the O-acetylation of propranolol catalyzed by Candida antarctica lipase B is an exception. We investigated the relation between the chemoselectivity of this reaction and the acyl group length. For this purpose, we compared the acyl groups: ethanoyl, butanoyl, octanoyl, and hexadecanoyl. We studied the Michaelis complexes between serine-acylated Candida antarctica lipase B and propranolol, employing a computational approach that involved sampling Michaelis complex conformations through ensemble docking plus consensus scoring and molecular dynamics simulations. The conformations were then classified as near attack conformations for acylation of the amino or hydroxy group. The relative populations of these two classes of conformations were found to be consistent with the experimentally observed chemoselective O-acetylation. We predict that increasing the length of the hydrocarbon chain of the acyl group will cause O-acylation to be unfavorable with respect to N-acylation. The nucleophilic attack of propranolol to the acylated lipase was found to be more favorable through the classical mechanism when compared with the proton shuttle mechanism.

In situ evaluation of 200 ppm fluoride toothpaste content trimetaphosphate, xylitol and erythritol on enamel demineralization and dental biofilm.

OBJECTIVE: To evaluate the effect of low-fluoride (F-) toothpaste and sodium trimetaphosphate (TMP) associated with xylitol and erythritol (XE) on enamel demineralization and biofilm composition. METHODS: This crossover double-blind in situ study consisted of five phases (seven days each), in which 14 volunteers wore oral appliances containing four enamel bovine blocks. The cariogenic challenge was performed by exposure to a 30% sucrose solution (6x/day). The toothpaste treatments (3x/day) were as follows: placebo (no F-/TMP/XE); 200 ppm F- (NaF) (200F); 1,100 ppm F- (1100F); 16% Xylitol and 4% Erythritol (XE); and 200 ppm F-, 0.2% TMP, 16% xylitol, and 4% erythritol (200F-TMP-XE). Percentage of surface hardness loss (%SH) and integrated loss of subsurface hardness (ΔKHN), and calcium (Ca2+), phosphate (PO43-), and F- on enamel and biofilm were determined; as well as insoluble extracellular polysaccharide (EPS). RESULTS: XE and 1100F groups showed no significant difference for %SH and ΔKHN values (p = 0.220 and p = 0.886), and the 200F-TMP-XE group had the lowest mineral loss (p < 0.001). Ca2+ and PO43- in the enamel showed the highest values (p < 0.001) for the 200F-TMP-XE group. Higher values of F- in the enamel and biofilm were observed for the 1100F group (p < 0.001). There was no difference for Ca2+ (p = 1.00) and EPS (p =0.918) values between XE and 200-TMP-XE groups in the biofilm, but their values were higher and lower than the 1100F (p = 0.002 and p = 0.029), respectively. CONCLUSIONS: 200F-TMP-XE promoted a greater protective effect against enamel demineralization and significantly affected the composition of biofilm formed in situ compared to 1100F toothpaste. CLINICAL SIGNIFICANCE: Low-F- toothpaste containing TMP and polyols can be considered an effective and safe measure to improve the oral health of individuals, especially patients with high caries activity.

Room Temperature Ionic Liquids in Asymmetric Hetero-Ene Type Reactions: Improving Organocatalyst Performance at Lower Temperatures.

Room temperature ionic liquids (RTILs) have been widely used as (co)solvents in several catalytic processes modifying, in most of the cases, the catalyst activity and/or the selectivity for the studied reactions. However, there are just a few examples of their use in hydrogen bonding organocatalysis. In this paper, we show the positive effect of a set of imidazole-based ionic liquids ([bmim]BF4 and [hmim]PF6) in the enantioselective addition of formaldehyde tert-butylhydrazone to prochiral α-keto esters catalyzed by a sugar-based chiral thiourea. Reactions performed in the presence of low percentages of RTILs led to an increase of the catalyst activity, thereby making possible to work at lower temperatures. Thus, the chiral tert-butyl azomethyl tertiary alcohols could be obtained with moderate to good conversions and higher enantioselectivities for most of the studied substrates when using up to 30 vol% of [hmim]PF6 as a cosolvent in processes performed in toluene.

Ultrasonic investigation of lacosamide in various alcohols at 298.15 K / Investigación ultrasónica de lacosamida en varios alcoholes a 298,15 K

SUMMARY Ultrasonic velocity, density and viscosity of Lacosamide were measured in various alcohols at 298.15 K. From these measured experimental data, various acoustical parameters such as Specific acoustical impedance (Z), Adiabatic compressibility (k s), Intermolecular free path length (L f ), Rao's molar sound function (R m), Molar compressibility (W), van der Waals constant (b), Solvation number (S n ), Thermal conductivity (K bm), Relaxation strength (r) have been calculated for understanding the molecular interactions occurring in the solution.

RESUMEN Se midieron la velocidad ultrasónica, la densidad y la viscosidad de soluciones de lacosamida en varios alcoholes a 298,15 K. A partir de estos datos experimentales, se calcularon varios parámetros acústicos para comprender las interacciones moleculares que ocurren en la solución, tales como la impedancia acústica específica (Z), la compresibilidad adiabática (k s), la longitud del camino libre intermolecular (L f), la función molar de sonido de Rao (R m), la compresibilidad molar ( W), la constante de van der Waals (b), el número de solvatación (Sn), la conductividad térmica (K bm), y la fuerza de relajación (r).

The cut-off effect of n-alcohols in lipid rafts: A lipid-dependent phenomenon☆.

n-Aliphatic alcohols act as anesthetics only up to a certain chain length, beyond which its biological activity disappears. This is known as the 'cut-off' phenomenon. Although the most accepted explanation is based on action sites in membrane proteins, it is not well understood why alcohols alter their functions. The structural dependence of these protein receptors to lipid domains known as 'lipid rafts', suggests a new approach to tackle the puzzling phenomenon. In this work, by performing molecular dynamic simulations (MDS) to explore the lipid role, we provide relevant molecular details about the membrane-alcohol interaction at the cut-off point regime. Since the high variability of the cut-off points found on protein receptors in neurons may be a consequence of differences in the lipid composition surrounding such proteins, our results could have a clear-cut importance.

Effect of rootstocks on volatile composition of Merlot wines.

BACKGROUND: Scion physiology and grape quality are impacted by rootstock choice. There is little available information about the effects of rootstock on wine volatile composition, particularly when comparing grafted with own-rooted grapevines. This field trial was aimed at studying the influence of rootstock choice on volatile composition of Merlot wines. RESULTS: Wines made from grapes harvested from own-rooted grapevines had the lowest content of (E)-3-hexenol, diethyl succinate and total ethyl esters and the highest content of 1-pentanol, 1-hexanol, (Z)-3-hexenol, diethyl malate and acetovanillone. Rootstocks such as 99R and 140Ru led to a higher content of total ethyl esters in wines followed by 110R, 1103P and Gravesac. According to odor activity values, Merlot wines were characterized by roses, sweat, cheese and banana aromas. CONCLUSIONS: This work provides valuable information about the potential impact of rootstocks on wine volatile composition for Merlot wines. © 2020 Society of Chemical Industry.