Esters in the Food and Cosmetic Industries: An Overview of the Reactors Used in Their Biocatalytic Synthesis.

Esters are versatile compounds with a wide range of applications in various industries due to their unique properties and pleasant aromas. Conventionally, the manufacture of these compounds has relied on the chemical route. Nevertheless, this technique employs high temperatures and inorganic catalysts, resulting in undesired additional steps to purify the final product by removing solvent residues, which decreases environmental sustainability and energy efficiency. In accordance with the principles of "Green Chemistry" and the search for more environmentally friendly methods, a new alternative, the enzymatic route, has been introduced. This technique uses low temperatures and does not require the use of solvents, resulting in more environmentally friendly final products. Despite the large number of studies published on the biocatalytic synthesis of esters, little attention has been paid to the reactors used for it. Therefore, it is convenient to gather the scattered information regarding the type of reactor employed in these synthesis reactions, considering the industrial field in which the process is carried out. A comparison between the performance of the different reactor configurations will allow us to draw the appropriate conclusions regarding their suitability for each specific industrial application. This review addresses, for the first time, the above aspects, which will undoubtedly help with the correct industrial implementation of these processes.

Ultrafiltration Membranes Modified with Reduced Graphene Oxide: Effect on Methyl Green Removal from Aqueous Solution.

In this work, three types of ultrafiltration membranes with different characteristics (GR60PP, RC70PP and GR80PP) have been tested for the removal of the dye methyl green. The tests were first carried out with the three membranes without any modification and then with the membranes' surfaces modified with reduced graphene oxide (rGO). The modification was achieved through physical treatment. The CR70PP membrane did not support the modification treatment and was discarded. The other membranes were initially characterized with distilled water tests to study the permeability to the solvent, and later, the permeate fluxes and the values of rejection coefficients were obtained at different working pressures with a fixed dye initial concentration. In addition, SEM images and SEM-EDX spectra of the native and modified membranes were obtained before and after the dye tests. The GR60PP membrane has shown the best results in relation to the modification because it has increased its rejection levels. On the opposite, the GR80PP membrane performs better without surface modification, achieving the highest rejection values and the highest permeate fluxes in its native form.

Feasibility of Adsorption Kinetic Models to Study Carrier-Mediated Transport of Heavy Metal Ions in Emulsion Liquid Membranes.

Emulsion liquid membranes have been successfully used for the removal of different types of organic and inorganic pollutants by means of carrier-mediated transport mechanisms. However, the models that describe the kinetics and transport of such mechanisms are very complex due to the high number of model parameters. Starting from an analysis of the similarity between the elemental mechanisms of carrier-mediated transport in liquid membranes and of transport in adsorption processes, this paper presents an experimental analysis of the possibility of applying kinetic and mechanistic models developed for adsorption to carrier-mediated transport in emulsion liquid membranes. We study the removal of a target species, in this case, Cu(II), by emulsion liquid membranes containing membrane phase solutions of benzoylacetone (carrier agent), Span 80 (emulsifying agent) and kerosene (diluent), and hydrochloric acid as a stripping agent in the product phase. The experimental results fit the pseudo-second-order adsorption kinetic model, showing good relationships between the experimental and model parameters. Although both Cu(II) diffusion through the feed/membrane interface boundary layer and complex Cu-benzoylacetone diffusion through the membrane phase controls Cu(II) transport, it is the former step that mainly controls the transport process.

Thiel embalming in neonates: methodology and benefits in medical training.

Current teaching and training methods for surgical techniques in the pediatric population involve artificial models (manikins), animals or adult human cadavers embalmed using various techniques. We found no references in the literature concerning the use of the Thiel method in the pediatric population. The aim of this study, therefore, was to assess the viability of using pediatric human cadavers embalmed through Thiel's technique and to compare them with standard pediatric manikins. After donation of a 24-week stillborn, the Thiel technique was carried out for fixation following the usual protocol. A video recording with eye-tracking glasses was used to perform an examination, and techniques. The same procedures were conducted on a pediatric manikin. Medical students, medical residents and physicians were asked to respond to questions in an online survey after being shown the video. A total of 92 responses were obtained. The Thiel-embalmed stillborn was assessed as superior to the manikin in all items. Our study confirmed that this technique is feasible even with extremely small donors. The value of this form of preservation for medical training is not widely known though it is receiving increasing interest. Our results show that Thiel fixation in pediatrics is clearly more highly valued than a manikin and offers great potential. This innovative application of the Thiel method in the pediatric population is technically possible. It poses no additional difficulties and is very positively assessed for undergraduate and postgraduate teaching.

Membranes for Water and Wastewater Treatment.

Water is a vital element for life and the environment [...].

Using Pressure-Driven Membrane Processes to Remove Emerging Pollutants from Aqueous Solutions.

Currently, there is great concern about global water pollution. Wastewater generally contains substances called emerging pollutants, and if the removal of these pollutants is not given sufficient attention, the pollutants can enter into the water cycle and reach the water supply for domestic use, causing adverse effects on the well-being of people. In order to avoid this menace, a multitude of techniques to reduce the high concentration levels of these substances dissolved in water are being researched and developed. One of the most-used techniques for this goal is the physical-chemical separation of contaminants in water through membrane technology. In this study, different membranes were tested with the objective of investigating the removal of three emerging pollutants: caffeine, metformin, and methyl-paraben. Initially, a nanofiltration (NF) membrane was selected, and the influence of pressure was evaluated in the rejection coefficients and permeate fluxes. Next, a screening of three new membranes to remove methyl paraben was completed. The influence of the operating variables, working pressure, and methyl paraben-feed concentration was checked. Finally, the solution-diffusion model was applied to predict the behavior of the different membranes in the removal of methyl paraben. A good correlation between experimental and calculated values of permeate flux and methyl paraben concentration was obtained.

The Application of a System of Eye Tracking in Laparoscopic Surgery: A New Didactic Tool to Visual Instructions.

Introduction: Laparoscopic surgery is an increasingly used technique, but it requires a high degree of learning, and communication between the operating room crew is considerably difficult. The use of eye tracking has been proposed as a didactic and evaluation tool in several settings, including in laparoscopy in simulators. Objectives: This study aimed to evaluate the usefulness of the use of eye tracking systems (Tobii glasses 2) in laparoscopic surgery as a didactic and assessment tool to improve communication in the operating room and improve patients' security. Methodology: An anonymous survey was sent to the students and medical teachers of a faculty of medicine and practicing doctors and residents. The message contained an explanation about the use of the Tobii glasses, a link to watch the video showing its use in a laparoscopic surgery, and the survey to complete after watching the video. Results: The survey was answered by 113 participants (51.3% medical students, 27.4% medical teachers, 18.6% practicing doctors, and 2.7% medicine residents). Eighty-three percent agreed with the usefulness of the "Tobii glasses" in the operating room for improving communication between the main surgeon and the assistant, for learning complex surgery techniques, for obtaining didactic videos, and for indicating anatomical structures. The item scored worst was the price of the glasses. Conclusions: It is possible to record and project expert gaze patterns in the operating room in real time using the Tobii glasses. This device allows improving communication among the surgical crew and the learning of residents and also improving the security of surgical patients.

The influence of feedstocks and additives in 23 added-value composts as a growing media component on Pythium irregulare suppressivity.

Alternative materials with added-value functions, such as phytopathogen suppression and biostimulant and/or biofertilising activity, have been proposed as peat substitutes in growing media. The aim of this work was to evaluate the effect of 23 agro-industrial composts as components of growing media for baby-leaf lettuce transplant production and their activity against the plant pathogen Pythium irregulare. The composts were produced by mixing different starting feedstocks-tomato waste, leek waste, olive mill cake and vineyard pruning waste-with different additives (coffee, thyme, lavender and rockrose waste), which were incorporated at the beginning of the maturation phase. The results obtained indicated that the composts were mature enough to be used as growing media. The fresh weight of the lettuce plants grown with the different composts was significantly higher than in plants obtained with peat. Composts with the coffee additive produced higher lettuce fresh weight, while those with thyme yielded a lower fresh weight. Moreover, composts as components of growing media showed significantly higher P. irregulare suppressiveness than peat. The composts with additives produced lower lettuce fresh weight than composts without additives, but showed higher suppressiveness. Composts with additives showed opposite results depending on whether they were exposed to pathogens or not. Composts with additives showed opposite results according to pathogen pressure or not. Out of all the composts studied, the compost with tomato waste and leek waste as the initial feedstock, and lavender as an additive, showed the highest suppressive capacity. After lettuce harvesting, the growing media with composts showed significantly lower concentrations of P. irregulare than peat. Principal Component Analysis (PCA) revealed that the growing media with compost can be grouped together according to the additive type.

Removal of Different Dye Solutions: A Comparison Study Using a Polyamide NF Membrane.

The removal of organic dyes in aquatic media is, nowadays, a very pressing environmental problem. These dyes usually come from industries, such as textiles, food, and pharmaceuticals, among others, and their harm is produced by preventing the penetration of solar radiation in the aquatic medium, which leads to a great reduction in the process of photosynthesis, therefore damaging the aquatic ecosystems. The feasibility of implementing a process of nanofiltration in the purification treatment of an aqueous stream with small size dyes has been studied. Six dyes were chosen: Acid Brown-83, Allura Red, Basic Fuchsin, Crystal Violet, Methyl Orange and Sunset Yellow, with similar molecular volume (from 250 to 380 Å). The nanofiltration membrane NF99 was selected. Five of these molecules with different sizes, shapes and charges were employed in order to study the behavior of the membrane for two system characteristic parameters: permeate flux and rejection coefficient. Furthermore, a microscopy study and a behavior analysis of the membrane were carried out after using the largest molecule. Finally, the Spiegler-Kedem-Katchalsky model was applied to simulate the behavior of the membrane on the elimination of this group of dyes.

Biocatalytic solutions to cyclomethicones problem in cosmetics.

Silicones are polymers that have properties of great interest for cosmetic and personal care industry, especially D4 (octamethylcyclotetrasiloxane) and D5 (decamethylcyclopentasiloxane), generically named cyclomethicones. However, different studies show the hypothesis that the use of these products is harmful and, therefore, several countries have adopted legislative actions to limit their use in personal care and cosmetic products. Faced with this new situation, different cosmetic companies began to look for different alternatives to cyclomethicones, mainly: organomodified silicones or esters. The former are based on the addition of functional groups to the main chain of silicon and oxygen. The latter represent a totally different line, since their functional group is the ester, but they have properties similar to silicones. Esters, especially branched-chain ones are currently the more promising alternative to replace cyclomethicones in cosmetic formulations. Nowadays, most of them are obtained by chemical reactions that require high temperatures and non-selective /contaminant catalysts that lead to low-quality final products. As an alternative, biocatalytic synthesis occurs always at mild operation conditions supplying ultra-pure, odor, and colorless products with less wastes and side reactions. Therefore, biocatalysis is a valid and environmentally sustainable option for the synthesis of silicone-substitute esters used in cosmetic formulations.

[Current situation of the organisation, resources and activity in paediatric cardiology in Spain]. / Situación actual de la organización, recursos y actividad en cardiología pediátrica en España.

INTRODUCTION: The results are presented on the «current situation of the organisation, resources and activity in paediatric cardiology in Spain¼. It was promoted by the Spanish Society of Paediatric Cardiology and Congenital Heart disease. MATERIAL AND METHODS: An analysis was carried out on the results obtained from a specifically designed questionnaire, prepared by the Spanish Society of Paediatric Cardiology and Congenital Heart disease, that was sent to all hospitals around the country that offer the speciality of paediatric cardiology. RESULTS: A total of 86 questionnaires were obtained, including 14 hospitals that perform cardiac surgery on children. A total of 190 paediatric cardiology consultants, 40 cardiac surgeons, and 27 middle grade doctors performing their paediatric residency (MIR program) were identified. All hospitals had adequate equipment to perform an optimal initial evaluation of any child with a possible cardiac abnormality, but only tertiary centres could perform complex diagnostic procedures, interventional cardiology, and cardiac surgery. In almost all units around the country, paediatric cardiology consultants were responsible for outpatient clinics and hospital admissions, whereas foetal cardiology units were still mainly managed by obstetricians. The number of diagnostic and therapeutic procedures was similar to those reported in the first survey, except for a slight decrease in the total number of closed cardiac surgery procedures, and a proportional increase in the number of therapeutic catheterisations. CONCLUSIONS: Paediatric Cardiology in Spain is performed by paediatric cardiology consultants that were trained initially as general paediatricians, and then completed a paediatric cardiology training period. Almost all units have adequate means for diagnosis and treatment. Efforts should be directed to create a national registry that would not only allow a prospective quantification of diagnostic and therapeutic procedures, but also focus on their clinical outcomes.

Use of Eye Tracking as an Innovative Instructional Method in Surgical Human Anatomy.

OBJECTIVE: Tobii glasses can record corneal infrared light reflection to track pupil position and to map gaze focusing in the video recording. Eye tracking has been proposed for use in training and coaching as a visually guided control interface. The aim of our study was to test the potential use of these glasses in various situations: explanations of anatomical structures on tablet-type electronic devices, explanations of anatomical models and dissected cadavers, and during the prosection thereof. An additional aim of the study was to test the use of the glasses during laparoscopies performed on Thiel-embalmed cadavers (that allows pneumoinsufflation and exact reproduction of the laparoscopic surgical technique). The device was also tried out in actual surgery (both laparoscopy and open surgery). DESIGN: We performed a pilot study using the Tobii glasses. SETTING: Dissection room at our School of Medicine and in the operating room at our Hospital. PARTICIPANTS: To evaluate usefulness, a survey was designed for use among students, instructors, and practicing physicians. RESULTS: The results were satisfactory, with the usefulness of this tool supported by more than 80% positive responses to most questions. There was no inconvenience for surgeons and that patient safety was ensured in the real laparoscopy. CONCLUSION: To our knowledge, this is the first publication to demonstrate the usefulness of eye tracking in practical instruction of human anatomy, as well as in teaching clinical anatomy and surgical techniques in the dissection and operating rooms.

Basic Study and Clinical Implications of Left Ventricular False Tendon. Is it Associated With Innocent Murmur in Children or Heart Disease?

INTRODUCTION AND OBJECTIVES: Left ventricular false tendon is a structure of unknown function in cardiac physiology that was first described anatomically by Turner. This condition may be related to various electrical or functional abnormalities, but no consensus has ever been reached. The purpose of this study was to determine the time of appearance, prevalence and histologic composition of false tendon, as well as its association with innocent murmur in children and with heart disease. METHODS: The basic research was performed by anatomic dissection of hearts from adult human cadavers to describe false tendon and its histology. The clinical research consisted of echocardiographic study in a pediatric population to identify any relationship with heart disease, innocent murmur in children, or other abnormalities. Fetal echocardiography was performed prenatally at different gestational ages. RESULTS: False tendon was a normal finding in cardiac dissection and was composed of muscle and connective tissue fibers. In the pediatric population, false tendon was present in 83% on echocardiography and showed a statistically significant association only with innocent murmur in children and slower aortic acceleration. The presence of false tendon was first observed on fetal echocardiography from week 20 of pregnancy. CONCLUSIONS: Left ventricular false tendon is a normal finding visualized by fetal echocardiography from week 20 and is present until adulthood with no pathologic effects except for innocent murmur during childhood. It remains to be determined if false tendon is the cause of the murmurs or if its absence or structural anomalies are related to disease.