Microbiological and Physicochemical Evaluation of Hydroxypropyl Methylcellulose (HPMC) and Propolis Film Coatings for Cheese Preservation.

Dairy products are highly susceptible to contamination from microorganisms. This study aimed to evaluate the efficacy of hydroxypropyl methylcellulose (HPMC) and propolis film as protective coatings for cheese. For this, microbiological analyses were carried out over the cheese' ripening period, focusing on total mesophilic bacteria, yeasts and moulds, lactic acid bacteria, total coliforms, Escherichia coli, and Enterobacteriaceae. Physicochemical parameters (pH, water activity, colour, phenolic compounds content) were also evaluated. The statistical analysis (conducted using ANOVA and PERMANOVA) showed a significant interaction term between the HPMC film and propolis (factor 1) and storage days (factor 2) with regard to the dependent variables: microbiological and physicochemical parameters. A high level of microbial contamination was identified at the baseline. However, the propolis films were able to reduce the microbial count. Physicochemical parameters also varied with storage time, with no significant differences found for propolis-containing films. Overall, the addition of propolis to the film influenced the cheeses' colour and the quantification of phenolic compounds. Regarding phenolic compounds, their loss was verified during storage, and was more pronounced in films with a higher percentage of propolis. The study also showed that, of the three groups of phenolic compounds (hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids), hydroxycinnamic acids showed the most significant losses. Overall, this study reveals the potential of using HPMC/propolis films as a coating for cheese in terms of microbiological control and the preservation of physicochemical properties.

Broken silence: 22,841 predicted deleterious synonymous variants identified in the human exome through computational analysis.

Synonymous single nucleotide variants (sSNVs) do not alter the primary structure of a protein, thus it was previously accepted that they were neutral. Recently, several studies demonstrated their significance to a range of diseases. Still, variant prioritization strategies lack focus on sSNVs. Here, we identified 22,841 deleterious synonymous variants in 125,748 human exomes using two in silico predictors (SilVA and CADD). While 98.2% of synonymous variants are classified as neutral, 1.8% are predicted to be deleterious, yielding an average of 9.82 neutral and 0.18 deleterious sSNVs per exome. Further investigation of prediction features via Heterogeneous Ensemble Feature Selection revealed that impact on amino acid sequence and conservation carry the most weight for a deleterious prediction. Thirty nine detrimental sSNVs are not rare and are located on disease associated genes. Ten distinct putatively non-deleterious sSNVs are likely to be under positive selection in the North-Western European and East Asian populations. Taken together our analysis gives voice to the so-called silent mutations as we propose a robust framework for evaluating the deleteriousness of sSNVs in variant prioritization studies.

AN ANATOMICAL STUDY OF THE THORACIC LIMB OF THE GIANT ANTEATER (MYRMECOPHAGA TRIDACTYLA) COMPARED WITH THE DOMESTIC DOG TO GUIDE SURGICAL APPROACHES TO THE HUMERUS AND RADIUS.

The giant anteater (Myrmecophaga tridactyla) is a neotropical mammal considered to be vulnerable to extinction. Recent increased interest in veterinary care in the giant anteater has prompted renewed interest in anatomical descriptions in this species. The terrestrial habits and slow movements of the giant anteater contribute to its susceptibility to vehicular trauma on highways, which is a significant cause of mortality in the species. This study describes the muscular anatomy of the thoracic limb and variations of the long bones with emphasis on the structures surrounding the humerus and radius. It also describes the possible surgical approaches for the management of fractures of humerus and radius, comparing these with the surgical approaches described in dogs (Canis lupus familiaris). Three giant anteater and three domestic dog cadavers, from deaths not related to this project, were used. The medial approach to the humeral diaphysis of the giant anteater resulted in the least tissue trauma, and provided access to the flattest surface for implant attachment. The lateral approach to the radius proved challenging, requiring total detachment of the extensor carpi radialis muscle and incision of the very robust abductor digitorum longus muscle to access the distal diaphysis. Although the giant anteater shares many similarities of the thoracic limb anatomy with the domestic dog, important differences exist. This comparative knowledge will allow veterinary practitioners to directly apply the principles of fracture repair in these species. Safe access to these bones for possible osteosynthesis is essential to allow implant placement and minimize postoperative complications in this species.

Shedding light on the physical nature of ion pair interactions involving carba-closo-dodecaborate anions. Insights from computation.

closo-Carboranes are structures that have been studied for many decades due to their vast applicability in medicine, catalysis, and energy storage. In order to go deeper into the physics behind the interactions of oppositely charged ions, which have potential applications in electrical energy storage and conversion devices, the present work aims to shed light on the physical nature of the interactions involving (R-CB11H11-, R = H, F, CH3, CF3) and Mq+ = Li+, Na+, Mg2+, Zn2+ ions. The bonding situations are evaluated in light of both canonical Kohn-Sham energy decomposition, EDA-NOCV, and local energy decomposition, LED, analyses. Electron and hole transports are also evaluated through charge transfer integrals. The findings reveal that such complexes present not only more significant electrostatic, but also non-negligible orbital contributions. Both energy decomposition analyses EDA-NOCV and DLPNO-LED confirm that the strength of ionic pair interactions (R-CB11H11- ↔ Mq+) is much more dependent on the nature of the cation employed than on the substituent R used. The results also reveal that charge transfers are not significant in such interacting systems.

Development and application of a composite circularity index.

Resource depletion and environmental pollution are increasingly a matter of concern for their adverse effects on ecosystems, human health, and the economy. Circular Economy (CE) practices can help us address these challenges. This paper proposes a composite circularity index (CI) to assess the level of implementation of CE practices. The main advantage of the proposed index is its ability to combine multiple indicators of circularity for different units operating in a given sector (given as inputs), using a 'Benefit of the Doubt' model. This new model is innovative in the manner it deals with ordinal scales and also by considering both relative and absolute performance indices. These indices are computed using mathematical programming tools, building on ideas from Data Envelopment Analysis models. Although the model can be applied to any sector, this work addresses the hotel industry in particular. The selection of indicators for this CI was based on seven blocks of the Circular Economy Action Plan and a literature review of circular practices. An application of the proposed index is performed by using data from Portuguese and Spanish hotels. The proposed CI allows the identification of the organizations with the best and worst performance in implementing the CE practices and clarifying the benchmarks they could follow to improve their level of circularity. Moreover, the index analysis also provides specific targets for improvement, indicating which circular practices should be improved for the lower performers to reach the implementation levels of the best performers.

Comparative Methods to Evaluate the Antioxidant Capacity of Propolis: An Attempt to Explain the Differences.

Propolis is a natural product produced by bees that contains a complex mixture of compounds, including phenolic compounds and flavonoids. These compounds contribute to its biological activities, such as antioxidant capacity. This study analysed the pollen profile, total phenolic content (TPC), antioxidant properties, and phenolic compound profile of four propolis samples from Portugal. The total phenolic compounds in the samples were determined by six different techniques: four different Folin-Ciocalteu (F-C) methods, spectrophotometry (SPECT), and voltammetry (SWV). Of the six methods, SPECT allowed the highest quantification, while SWV achieved the lowest. The mean TPC values for these methods were 422 ± 98 and 47 ± 11 mg GAE/g sample, respectively. Antioxidant capacity was determined by four different methods: DPPH, FRAP, original ferrocyanide (OFec), and modified ferrocyanide (MFec). The MFec method gave the highest antioxidant capacity for all samples, followed by the DPPH method. The study also investigated the correlation between TPC and antioxidant capacity with the presence of hydroxybenzoic acid (HBA), hydroxycinnamic acid (HCA), and flavonoids (FLAV) in propolis samples. The results showed that the concentrations of specific compounds in propolis samples can significantly impact their antioxidant capacity and TPC quantification. Analysis of the profile of phenolic compounds by the UHPLC-DAD-ESI-MS technique identified chrysin, caffeic acid isoprenyl ester, pinocembrin, galangin, pinobanksin-3-O-acetate, and caffeic acid phenyl ester as the major compounds in the four propolis samples. In conclusion, this study shows the importance of the choice of method for determining TPC and antioxidant activity in samples and the contribution of HBA and HCA content to their quantification.

Screening of the Role of the Chemical Structure in the Electrochemical Stability Window of Ionic Liquids: DFT Calculations Combined with Data Mining.

Ionic liquids have attracted the attention of researchers as possible electrolytes for electrochemical energy storage devices. However, their properties, such as the electrochemical stability window (ESW), ionic conductivity, and diffusivity, are influenced both by the chemical structures of cations and anions and by their combinations. Most studies in the literature focus on the understanding of common ionic liquids, and little effort has been made to find ways to improve our atomistic understanding of those systems. The goal of this paper is to explore the structural characteristics of cations and anions that form ionic liquids that can expand the HOMO/LUMO gap, a property directly linked to the ESW of the electrolyte. For that, we design a framework for randomly generating new ions by combining their fragments. Within this framework, we generate about 104 cations and 104 anions and fully optimize their structures using density functional theory. Our calculations show that aromatic cations are less stable ionic liquids than aliphatic ones, an expected result if chemical rationale is used. More importantly, we can improve the gap by adding electron-donating and electron-withdrawing functional groups to the cations and anions, respectively. The increase can be about 2 V, depending on the case. This improvement is reflected in a wider ESW.

Semi-Quantitative Discrimination of Honey Adulterated with Cane Sugar Solution by an ETongue.

This study successfully applied a potentiometric E-tongue with 20 cross-selectivity lipidic polymeric membranes in the discrimination of three semi-quantitative groups, that represented the following intervals of honey adulteration percentage with cane sugar: 0 %; [0, 10]%; [10, 20]% of adulteration. We analysed five different types of Portuguese honey; five brands of cane sugar were added to the adulterated samples; a comparative analysis was then performed. Linear discriminant analysis coupled with a tabu search algorithm for feature selection was applied to the ETongue's analytical data to select the best model. A discriminant model with 12 sensors was obtained. This model classified correctly all samples in both in internal (train data, 15 samples) and external validation (test data,10 samples). Also, multiple linear regression with tabu search was applied to verify if ETongue's data would allow quantifying the honey's adulteration level. The results showed that it was possible to obtain a quantitative model but with unsatisfactory predictive performance in the test data group (external validation), giving, in general, values below the expected concentrations. E-tongue is a real-time green, flexible and low-cost analytical tool that requires minimum sample preparation and no special technical skills, being a promising tool for everyday application.

Efficiency benchmarking of wastewater service providers: An analysis based on the Portuguese case.

Sustainability is increasingly important in the wastewater treatment sector, and benchmarking studies are needed to identify the best practices in using resources efficiently. This work addresses this need by characterizing and benchmarking this sector in Portugal. Data from around 120 service providers, from 2015 to 2019, regarding inputs consumption, desirable and undesirable outputs, are used in a data envelopment analysis to benchmark these operators and to determine improvement potentials. A productivity change analysis revealed an increase from 2015 to 2019, essentially due to an increased technical efficiency. On the other hand, no real technological change seems to have occurred. A positive effect of the service providers dimension and certifications (quality, environmental and energy) on efficiency was found. Service providers with concessionary governance models and urban typology presented the highest efficiencies, whereas treatment plants underuse contributed negatively to efficiency. These results can inform the definition of strategic policies for the water sector, namely concerning the aggregation of small providers. The proposed methodology, based on the use of a comprehensive new set of studied variables and explanatory factors, allowed to determine the best characteristics regarding the techno-economic efficiency of Portuguese service providers, and can potentially be applied to identify role models in other countries.

USE OF ACRYLIC RESIN PROSTHESES IN THE TREATMENT OF RHINOTHECAL FRACTURES.

This report describes the use of synthetic acrylic resin prostheses in five birds with rhinothecal fracture. Satisfactory biomechanical and clinical results were obtained in all cases, enabling early return to function of the beak. The patients, a roadside hawk (Rupornis magnirostris; case 1), a cockatiel (Nymphicus hollandicus; case 2), two turquoise-fronted parrots (Amazona aestiva; cases 3 and 4), and a maritaca (Pionus maximiliani; case 5), all suffered rhinothecal fractures with extensive bone loss, resulting in malnutrition, dehydration, and difficulty in handling food. An acrylic prosthesis was chosen in all cases, with the resin mold formed with two 1.0-mm pins in four cases, and cerclage wires in case 2. All birds made an excellent recovery and showed early use of the beak, with no complications for up to 15 mon. After 21 d of observation, the patients were moved to zoo enclosures for rehabilitation. The treatment of rhinothecal fractures is very challenging and requires a combination of orthopedic and dental techniques to provide full recovery of the species' natural functions.

May Measurement Month 2019: an analysis of blood pressure screening results from Cape Verde.

The Cabo Verdean population is aging and, consequently, non-communicable diseases, namely cardiovascular diseases, are increasing, with hypertension being an important risk factor. Following Cabo Verde's engagement with the May Measurement Month (MMM) campaign, in 2019, it was possible to improve the screening capacity, at the same time that a major social mobilization campaign was carried out to improve the population's knowledge about raised blood pressure (BP) and its consequences. With activities on nine islands, telemedicine was used to train researchers and volunteers. The MMM app was used to collect participant data. Individuals aged ≥18 years were recruited through opportunistic sampling. Each participant completed a questionnaire on demographic, lifestyle and environmental factors and had three BP measurements and weight and height measurements. Hypertension was defined as a systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg (mean of the second and third readings), or when using antihypertensive medication. When respondents did not provide three BP readings, multiple imputation using chained equations was used to calculate the mean of the second and third readings. A total of 17 627 individuals [mean age of 42.7 (SD 16.2); 63.8% women] were screened. After multiple imputation, 5990 (34.0%) had hypertension, of which 68.4% knew the diagnosis previously and 51.3% used antihypertensive drugs. The reported use of antihypertensive medication and a previous diagnosis of hypertension were strong predictors of higher levels of systolic and diastolic BP. Corrective actions were taken with an updated national protocol for hypertension treatment in primary health care. The II Non-Communicable Diseases Survey corroborated MMM national data that we see as an ideal initiative to reach the public, raising awareness about this important cardiovascular risk factor and providing political decision instruments.

DOUBLE PLATING FOR FRACTURES IN GIANT ANTEATERS (MYRMECOPHAGA TRIDACTYLA).

The fixation of fractures in wild animals has been a great challenge for veterinarians, because they will inevitably face a unique anatomical characteristic with scarce studies or reports published. Fracture fixation should promote adequate stability and early return to limb function, taking into account biomechanical characteristics of the bones, body weight, and natural habits of wildlife. Three bone fractures from two giant anteaters (Myrmecophaga tridactyla) referred at the veterinary teaching hospital on different occasions were treated by a double plating technique. The two free-ranging anteaters incurred their injuries when struck by an automobile. The first anteater (Ant 1) had a complete oblique fracture of the proximal third of the right femur and a complete comminuted fracture of the distal third of the right tibia. Surgical stabilization was performed by double plating to stabilize the femur and tibia. The second anteater (Ant 2) had a complete transverse fracture of the mid-diaphysis of the right radius and ulna, and it was fixed with a medial plate on the radius and a caudal plate on the ulna. The patients were able to walk 24 hr after the surgical procedures. Bone consolidation was observed at 60 days postoperatively, with no complications. The biggest challenges were related to anatomical characteristics for surgical approaches and the ability to promote a fixation strong enough to support the weight and strength of the animal, allowing early return to limb function.

Molecular Dynamics Simulations of Polymer-Ionic Liquid (1-Ethyl-3-methylimidazolium Tetracyanoborate) Ternary Electrolyte for Sodium and Potassium Ion Batteries.

We have performed molecular dynamics (MD) simulations of 1-ethyl-3-methylimidazolium tetracyanoborate ([EMIM]+[B(CN)4]-) ionic liquid to investigate the impact of addition of Na+/K+[B(CN)4]- salts and poly(ethylene oxide) (PEO6) on transport properties. These ternary mixtures are promising electrolyte materials for Na+-ion and K+-ion batteries as alternatives to the traditional Li+-ion ones. In addition, local structure was assessed through radial distribution functions. Our main findings are the following: (1) when compared to systems with larger amounts of Na+ and K+, it was observed that lower concentrations enhance the overall ionic conductivity and decrease viscosity; (2) Na+ and K+ cations prefer to be coordinated to the polymer chains rather than the [B(CN)4]- anions; (3) transport properties are improved when PEO6 oligomers are included in the electrolyte medium but these improvements continue only up to an optimum amount of PEO6. Beyond this amount, further addition of PEO6 did not have any additional impact on transport properties.

May Measurement Month 2018: an analyses of blood pressure screening results from Cabo Verde.

Raised blood pressure (BP) is the biggest contributor to mortality and disease burden in Cabo Verde. May Measurement Month (MMM) is a global campaign set up in 2017 to raise awareness of high BP. In 2018, we aimed to expand the campaign by including a greater number of centres to increase awareness. Nine islands participated in MMM 2018. Volunteers (≥18 years) were recruited through opportunistic sampling at a variety of screening sites. Each participant had three BP measurements and completed a questionnaire on demographic, lifestyle, and environmental factors. Hypertension was defined as a systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg, or taking antihypertensive medication. In total, 98.0% of screenees provided three BP readings and multiple imputation using chained equations was used to impute missing readings. A total of 8008 individuals (mean age 40.4 years; 68.5% female) were screened. After multiple imputation, 2666 (33.3%) individuals had hypertension, of whom 74.8% were aware of their previous diagnosis and 55.8% were taking antihypertensive medication. Of those on medication, 39.1% were controlled and of all hypertensives, 21.8% were controlled. We detected 44.2% of individuals with untreated hypertension and 60.9% of treated individuals were inadequately treated. The Cape Verdean population is ageing and consequently cardiovascular disease is increasing, with hypertension being an important risk factor. Corrective actions need to be taken by the government. MMM is an ideal initiative to reach the public by raising awareness of this major cardiovascular risk factor.

Response to the letter to the editor: "Score risk scale as a prognostic factor after sudden sensorineural hearing loss".

We appreciate the opportunity to comment the observations on our paper entitled "Score risk scale as a prognostic factor after sudden sensorineural hearing loss", by Capuano et al. This letter highlights several important points, including the role of hyperbaric oxygen therapy and the possible association between patent foramen ovale and sudden sensorineural hearing loss (SSHL). Further research is needed to strengthen the association between cardiovascular risk and SSHL. We thank the authors for their insights into our paper and for adding their experience and observations on the potential role of cardiovascular risk in the etiology of SSHL.

Analysis of Phenolic Content in Grape Seeds and Skins by Means of a Bio-Electronic Tongue.

A bio-electronic tongue has been developed to evaluate the phenolic content of grape residues (seeds and skins) in a fast and easy way with industrial use in mind. A voltammetric electronic tongue has been designed based on carbon resin electrodes modified with tyrosinase combined with electron mediators. The presence of the phenoloxydase promotes the selectivity and specificity towards phenols. The results of multivariate analysis allowed discriminating seeds and skins according to their polyphenolic content. Partial least squares (PLS) has been used to establish regression models with parameters related to phenolic content measured by spectroscopic methods i.e., total poliphenol content (TPC) and Folin-Ciocalteu (FC) indexes. It has been shown that electronic tongue can be successfully used to predict parameters of interest with high correlation coefficients (higher than 0.99 in both calibration and prediction) and low residual errors. These values can even be improved using genetic algorithms for multivalent analysis. In this way, a fast and simple tool is available for the evaluation of these values. This advantage may be due to the fact that the electrochemical signals are directly related to the phenolic content.

May Measurement Month 2017: Results from Cabo Verde-Sub-Saharan Africa.

Elevated blood pressure (BP) is a growing burden worldwide, leading to over 10 million deaths each year. May Measurement Month (MMM) is a global initiative aimed at raising awareness of high BP and to act as a temporary solution to the lack of screening programmes worldwide. Cabo Verde is in an epidemiological transition, with replacement of infectious diseases by chronic diseases, and the major cause of morbidity/mortality is cardiovascular disease which caused 28.9% of the total deaths in 2016. The only data we have are from 2007-the Ministry of Health and Social Security used a study STEP approach in which the prevalence of hypertension was 35%. An opportunistic cross-sectional survey of volunteers aged ≥18 was carried out in May 2017 (MMM17). Blood pressure measurement, the definition of hypertension and statistical analysis followed the standard MMM protocol. A total of five islands and eight centres, including hospitals and local health centres participated in this study, with about 20 volunteers/investigators. A total of 2630 individuals were screened during MMM17. After multiple imputation, 760 (29.0%) had hypertension defined as being on BP lowering treatment or having a BP ≥140/90 mmHg. Of individuals not receiving anti-hypertensive medication, 232 (11.1%) were hypertensive. Of 522 individuals receiving anti-hypertensive medication with an available BP, 225 (43.1%) had uncontrolled BP. MMM17 was the largest BP screening campaign undertaken in Cabo Verde. The proportion of hypertensives in the population in study was 29.0%, with most of these on treatment, and 43.1% of those on treatment with uncontrolled hypertension. These results suggest that opportunistic screening can identify significant numbers with raised BP.

In vitro enantioselective study of the toxicokinetic effects of chiral fungicide tebuconazole in human liver microsomes.

Tebuconazole (TEB) is a chiral triazole fungicide that is globally marketed and used as a racemic mixture to control plant pathogens. Due to its use as a racemic mixture, TEB may exhibit enantioselective toxicokinetics toward nontarget organisms, including humans. Therefore, the in vitro enantioselective metabolism of TEB by cytochrome P450 enzymes (CYP450) was studied using human liver microsomes, and the in vivo toxicokinetic parameters were predicted. A new enantioselective, reversed-phase LC-MS/MS method was developed and validated to analyze the enantiomers of TEB and its main metabolite, 1-hydroxytebuconazole (TEBOH). In vitro metabolic parameters were obtained, and in vitro-in vivo extrapolations were performed. Michaelis-Menten and atypical biphasic kinetic profiles were observed with a total intrinsic clearance ranging from 53 to 19 mL min-1 mg-1. The in vitro-in vivo extrapolation results showed that TEB first passage effect by the liver seems to be negligible, with hepatic clearance and extraction ratios ranging from 0.53 to 5.0 mL min-1 kg-1 and 2.7-25%, respectively. Preferential metabolism of (+)-TEB to rac-TEB and (-)-TEB was observed, with preferential production of (+)-TEBOH. Furthermore, reaction phenotyping studies revealed that, despite the low hepatic clearance in the first pass metabolism of TEB, multiple human CYP450 isoforms were involved in TEB metabolism when TEBOH enantiomers were generated, mainly CYP3A4 and CYP2C9, which makes TEB accumulation in the human body more difficult due to multiple metabolic pathways.

SCORE risk scale as a prognostic factor after sudden sensorineural hearing loss.

INTRODUCTION: Sudden sensorineural hearing loss (SSHL) is an otologic urgency whose treatment is still controversial. Its etiology remains largely unknown in most cases and predicting its prognosis is still a challenge. Cardiovascular risk factors (CVRF) have been implicated in the etiopathogenesis of this entity. OBJECTIVES: Application of the SCORE (Systematic Coronary Risk Evaluation) risk scale in patients with SSHL and evaluation of its potential prognostic value in recovery in patients with CVRF. MATERIALS AND METHODS: Prospective analysis of patients with SSHL admitted for protocol treatment including intravenous corticosteroid therapy associated to weekly intratympanic injection in the event of therapeutic failure or severe hearing loss at admission. Demographic, audiometric, clinical and imaging data were assessed. The SCORE risk scale was applied and the audiometric recovery was compared among different risk groups. RESULTS: Our overall complete and partial recovery rates were 35.9% and 26%, respectively. More than a half of our patients had at least one CVRF. Of these, overweight/obesity, hyperlipidemia and hypertension were the most common. In our sample, patients with CVRF and higher SCORE risk presented higher PTA at admission and also worse hearing outcome, although these results were not statically significant. CONCLUSION: This preliminary study could not confirm the validity for SCORE scale for cardiovascular risk assessment in predicting audiometric recovery in patients with SSHL with multiple comorbidities. Further research with larger samples are needed to elucidate the etiology of SSHL and the exact role of cardiovascular risk factors in the pathophysiology of SSHL. LEVEL OF EVIDENCE: 4.

An Explanation about the Use of (S)-Citronellal as a Chiral Derivatizing Agent (CDA) in 1H and 13C NMR for Sec-Butylamine, Methylbenzylamine, and Amphetamine: A Theoretical-Experimental Study.

A chiral derivatizing agent (CDA) with the aldehyde function has been widely used in discriminating chiral amines because of the easy formation of imines under mild conditions. There is a preference for the use of cyclic aldehydes as a CDA since their lower conformational flexibility favors the differentiation of the diastereoisomeric derivatives. In this study, the imines obtained from the reaction between (S)-citronellal and the chiral amines (sec-butylamine, methylbenzylamine, and amphetamine) were analyzed by the nuclear Overhauser effect (NOE). Through NOE, it was possible to observe that the ends of the molecules were close, suggesting a quasi-folded conformation. This conformation was confirmed by theoretical calculations that indicated the London forces and the molecular orbitals as main justifications for this conformation. This conformational locking explains the good separation of 13C NMR signals between the diastereomeric imines obtained and, consequently, a good determination of the enantiomeric excess using the open chain (S)-citronellal as a CDA.