Bioreactor design for enzymatic hydrolysis of biomass under the biorefinery concept

The dependence on non-renewable resources, particularly fossil fuels, has awaken a growing interest in research of sustainable alternative energy sources, such as bioethanol. The production of bioethanol from lignocellulosic materials comprises three main stages, starting with a pretreatment, followed by an enzymatic hydrolysis step where fermentable sugars are obtained for the final fermentation process. Enzymatic hydrolysis represents an essential step in the bioethanol production, however there are some limitations in it that hinders the process to be economically feasible. Different strategies have been studied to overcome these limitations, including the enzyme recycling and the utilization of high solids concentrations. Several investigations have been carried out in different bioreactor configurations with the aim to obtain higher yields of glucose in the enzymatic hydrolysis stage; however, the commonest are Stirred Tank Bioreactors (STBR) and Membrane Bioreactors (MBR). In general, the key criteria for a bioreactor design include adequate mass transfer, low shear stress, and efficient mixing that allows the appropriated interaction between the substrate and the enzyme. Therefore, this review will address the main aspects to be considered for a bioreactor design, as well as, the operational conditions, some characteristics and mode of operating strategies of the two main bioreactors used in the enzymatic hydrolysis stage. Moreover, two types of pneumatically agitated bioreactors, namely bubble column and gas-lift bioreactors, are discussed as promising alternatives to develop enzymatic saccharification due to their low energy consumption compared with STBR.This work was financial supported by the Secretary of Public Education of Mexico – Mexican Science and Technology Council (SEPCONACYT) with the Basic Science Project-2015-01 (Ref. 254808), and the Energy Sustainability Fund 2014-05 (CONACYT-SENER), Mexican Centre for Innovation in Bioenergy (Cemie-Bio), and Cluster of Bioalcohols (Ref. 249564). The author Marcela Pino also thanks the National Council for Science and Technology (CONACYT, Mexico) for her Master Fellowship support (grant number: 611312/452636).info:eu-repo/semantics/publishedVersio

Biotechnological Approach for the Production of Prebiotics and Search for New Probiotics and their Application in the Food Industry

Background and objective: Prebiotics and probiotics intake have been widely recognized in past recent years due to possessing multiple health benefits. Prebiotics are non-digestible carbohydrates that promote the growth and/or activity of beneficial bacteria in the colon which improves the health. Moreover, the incorporation of probiotics in food has also been a growing practice due to its immunomodulatory effect, the production of organic acids and other compounds that promotes the absorption of nutrients and the general health of the digestive system.Results and conclusion: Biotechnological strategies have been proposed for prebiotic production and purification in order to meet the demand to be included as ingredients in functional food formulation. Different aspects related to the substrates and different fermentation systems for their production as well as the purification and characterization processes are addressed. Also, we will present the benefits promoted by probiotics, the methods of isolation and characterization, as well as the evaluation of these attributes, so that they can be used in the food industry. With the technological developments in prebiotics and probiotics, it will be possible to deliver foods that respond to consumer demand with low cost and with pleasant sensory characteristics as well as providing beneficial health effects.Conflict of interest: The authors declare no conflict of interest

Marcos da liderança em empresas: o caso da cidade de bucaramanga (colômbia) e sua área metropolitana /

Universidad Autónoma del Carib

Exploring long COVID condition in Latin America: Its impact on patients’ activities and associated healthcare use

"Background: Studies exploring long COVID condition (LCC) in low- and middle-income countries are scarce. Further characterization of LCC patients experiencing activity limitations and their associated healthcare use is needed. This study aimed to describe LCC patients’ characteristics, its impact on activities, and associated healthcare use in Latin America (LATAM). Participants: Individuals who (cared for someone or) had COVID-19 and could read, write, and comprehend Spanish and lived in a LATAM country were invited to complete a virtual survey. Sociodemographic characteristics, COVID-19 and LCC symptoms, activity limitations, and healthcare use. Results: Data from 2,466 people from 16 countries in LATAM were analyzed (females = 65.9%; mean age of 39.5 ± 53.3 years). 1,178 (48%) of the respondents had LCC symptoms (≥3 months). These were more likely to have COVID-19 earlier in the pandemic, were older, had no COVID vaccines, had more comorbidities, needed supplementary oxygen, and reported significantly more COVID-19 symptoms during the infectious period. 33% of the respondents visited a primary care provider, 13% went to the emergency department, 5% were hospitalized, 21% visited a specialist, and 32% consulted ≥1 therapist for LCC symptoms mainly extreme fatigue, sleep difficulties, headaches, muscle or joint pain, and shortness of breath with activity. The most consulted therapists were respiratory therapists (15%) and psychologists (14%), followed by physical therapists (13%), occupational therapists (3%), and speech pathologists (1%). One-third of LCC respondents decreased their regular activities (e.g., work, school) and 8% needed help with activities of daily living (ADLs). LCC respondents who reduced their activities reported more difficulty sleeping, chest pain with activity, depression, and problems with concentration, thinking, and memory, while those who needed help with ADLs were more likely to have difficulty walking, and shortness of breath at rest. Approximately 60% of respondents who experienced activity limitations sought a specialist and 50% consulted therapists. Conclusions and relevance: Results supported previous findings in terms of the LCC demographics, and provided insight into LCC impact on patients’ activities and healthcare services used in LATAM. This information is valuable to inform service planning and resource allocation in alignment with the needs of this population.

Electrochemical Impedance Spectroscopy (EIS): A Review Study of Basic Aspects of the Corrosion Mechanism Applied to Steels

AC impedance measurements have been applied for over twenty years in electrochemistry and physics to investigate the electrical properties of conductive materials and their interfaces using an external electrical impulse (VOLTAGE, V or CURRENT, I) as driving force. Furthermore, its application has recently appeared to be destined in the Biotechnology field as an effective tool for rapid microbiologic diagnosis of living organism in situ. However, there is no doubt that the electrochemical impedance spectroscopy (EIS) is still one of the most useful techniques around the world for metal corrosion control and its monitoring. Corrosion has long been recognized as one of the most expensive stumbling blocks that concern many industries and government agencies, because it is a steel destructive phenomenon that occurs due to the chemical interaction with aqueous environments and takes place at the interface between metal and electrolyte producing an electrical charge transfer or ion diffusion process. Consequently, it is experimentally possible to determine through the EIS technique the mechanism and control that kinectics of corrosion reactions encounter. First, EIS data is collected through a potentiostat/ galvanostat apparatus. After, it is fitted to a mathematical model (i.e. an equivalent electrical circuit, EEC) for its interpretation and analysis, fundamentally seeking a meaningful physical interpretation. Finally, this review reports some basic aspects of the corrosion mechanism applied to steels through the experimental EIS response using Nyquist or Bode plots. Examples are given for different applied electrochemical impedance cases in which steel is under study intentionally exposed to a corrosive aqueous solution by applying a sinusoidal potential at various test conditions

Diversity of HLA Class I and Class II blocks and conserved extended haplotypes in Lacandon Mayans.

Here we studied HLA blocks and haplotypes in a group of 218 Lacandon Maya Native American using a high-resolution next generation sequencing (NGS) method. We assessed the genetic diversity of HLA class I and class II in this population, and determined the most probable ancestry of Lacandon Maya HLA class I and class II haplotypes. Importantly, this Native American group showed a high degree of both HLA homozygosity and linkage disequilibrium across the HLA region and also lower class II HLA allelic diversity than most previously reported populations (including other Native American groups). Distinctive alleles present in the Lacandon population include HLA-A*24:14 and HLA-B*40:08. Furthermore, in Lacandons we observed a high frequency of haplotypes containing the allele HLA-DRB1*04:11, a relatively frequent allele in comparison with other neighboring indigenous groups. The specific demographic history of the Lacandon population including inbreeding, as well as pathogen selection, may have elevated the frequencies of a small number of HLA class II alleles and DNA blocks. To assess the possible role of different selective pressures in determining Native American HLA diversity, we evaluated the relationship between genetic diversity at HLA-A, HLA-B and HLA-DRB1 and pathogen richness for a global dataset and for Native American populations alone. In keeping with previous studies of such relationships we included distance from Africa as a covariate. After correction for multiple comparisons we did not find any significant relationship between pathogen diversity and HLA genetic diversity (as measured by polymorphism information content) in either our global dataset or the Native American subset of the dataset. We found the expected negative relationship between genetic diversity and distance from Africa in the global dataset, but no relationship between HLA genetic diversity and distance from Africa when Native American populations were considered alone

Exploring long COVID condition in Latin America: Its impact on patients’ activities and associated healthcare use

BackgroundStudies exploring long COVID condition (LCC) in low- and middle-income countries are scarce. Further characterization of LCC patients experiencing activity limitations and their associated healthcare use is needed. This study aimed to describe LCC patients’ characteristics, its impact on activities, and associated healthcare use in Latin America (LATAM).ParticipantsIndividuals who (cared for someone or) had COVID-19 and could read, write, and comprehend Spanish and lived in a LATAM country were invited to complete a virtual survey. Sociodemographic characteristics, COVID-19 and LCC symptoms, activity limitations, and healthcare use.ResultsData from 2,466 people from 16 countries in LATAM were analyzed (females = 65.9%; mean age of 39.5 ± 53.3 years). 1,178 (48%) of the respondents had LCC symptoms (≥3 months). These were more likely to have COVID-19 earlier in the pandemic, were older, had no COVID vaccines, had more comorbidities, needed supplementary oxygen, and reported significantly more COVID-19 symptoms during the infectious period. 33% of the respondents visited a primary care provider, 13% went to the emergency department, 5% were hospitalized, 21% visited a specialist, and 32% consulted ≥1 therapist for LCC symptoms mainly extreme fatigue, sleep difficulties, headaches, muscle or joint pain, and shortness of breath with activity. The most consulted therapists were respiratory therapists (15%) and psychologists (14%), followed by physical therapists (13%), occupational therapists (3%), and speech pathologists (1%). One-third of LCC respondents decreased their regular activities (e.g., work, school) and 8% needed help with activities of daily living (ADLs). LCC respondents who reduced their activities reported more difficulty sleeping, chest pain with activity, depression, and problems with concentration, thinking, and memory, while those who needed help with ADLs were more likely to have difficulty walking, and shortness of breath at rest. Approximately 60% of respondents who experienced activity limitations sought a specialist and 50% consulted therapists.Conclusions and relevanceResults supported previous findings in terms of the LCC demographics, and provided insight into LCC impact on patients’ activities and healthcare services used in LATAM. This information is valuable to inform service planning and resource allocation in alignment with the needs of this population

Continuing education on Paleontology: the experience with the project “Workshop on Paleontology: fossils inside the classroom”

The Natural Sciences are essential in the education of citizens aware of the reality in which they live. In this context, Paleontology has an important in basic education, given its multidisciplinary nature, what enables the integrated understanding of the events and phenomena that changed natural environments during the geological history of our planet. In addition, its teaching promotes the awareness of the importance of the fossils as public patrimony, essential for their preservation. Even though current technology allows quick and easy access to information, the selection of subjects and practical activities is often inadequate, as most teachers do not have expertise in paleontology. With this scenario in mind, we created the “Workshop on Paleontology: fossils inside the classroom”, culminating in a continuing education workshop, aiming to promote better education of Palentology in schools (basic education). The project already held two workshops, in which several theoretical-practical activities were carried out with teachers and future educators of the public-school network of Ribeirão Preto and Jaboticabal cities, possible multipliers of scientific and patrimonial knowledge within the classroom. After the second workshop, a questionnaire was conducted with students and aimed to assess the course and improve upcoming workshops.O ensino das Ciências Naturais é essencial na formação de cidadãos como seres cientes da realidade em que vivem. No contexto da formação básica, a Paleontologia tem papel importante, dada sua natureza multidisciplinar, e seu estudo auxilia na compreensão integrada dos eventos e fenômenos que transformaram ambientes durante a história geológica do nosso planeta. Ademais, seu ensino promove a conscientização da importância dos fósseis como patrimônio público, essencial para sua preservação. Mesmo com a atual facilidade de acesso à informação, a seleção de conteúdos e práticas adequadas nem sempre é apropriada, uma vez que poucos professores têm experiência com a Paleontologia. Tendo tais desafios em mente, formulamos o projeto "Oficina de Paleontologia: os fósseis dentro da sala de aula", no formato de um curso de extensão de educação continuada, com o objetivo de fomentar o ensino elementar de qualidade em Paleontologia nas escolas. Em duas edições, diversas atividades teórico-práticas foram realizadas com professores e futuros educadores da rede escolar pública de Ribeirão Preto e Jaboticabal, possíveis multiplicadores do conhecimento científico e patrimonial dentro da sala de aula. Após o término da segunda oficina, um questionário realizado com os participantes visou avaliar o curso, criando um espaço para críticas e sugestões