Strategies for advancing inclusive biodiversity research through equitable practices and collective responsibility.

Biodiversity research is essential for addressing the global biodiversity crisis, necessitating diverse participation and perspectives of researchers from a wide range of backgrounds. However, conservation faces a significant inclusivity problem because local expertise from biodiversity-rich but economically disadvantaged regions is often underrepresented. This underrepresentation is driven by linguistic bias, undervalued contributions, parachute science practices, and capacity constraints. Although fragmented solutions exist, a unified multistakeholder approach is needed to address the interconnected and systemic conservation issues. We devised a holistic framework of collective responsibility across all research participants and tailored strategies that embrace diversity and dismantle systemic barriers to equitable collaboration. This framework delineates the diverse actors and practices required for promoting inclusivity in biodiversity research, assigning clear responsibilities to researchers, publishers, institutions, and funding bodies. Strategies for researchers include cultivating self-awareness, expanding literature searches, fostering partnerships with local experts, and promoting knowledge exchange. For institutions, we recommend establishing specialized liaison roles, implementing equitable policies, allocating resources for diversity initiatives, and enhancing support for international researchers. Publishers can facilitate multilingual dissemination, remove financial barriers, establish inclusivity standards, and ensure equitable representation in peer review. Funders must remove systemic barriers, strengthen research networks, and prioritize equitable resource allocation. Implementing these stakeholder-specific strategies can help dismantle deep-rooted biases and structural inequities in biodiversity research, catalyzing a shift toward a more inclusive and representative model that amplifies diverse perspectives and maximizes collective knowledge for effective global conservation.

Estrategias para las prácticas equitativas y la responsabilidad colectiva en la investigación de la biodiversidad Resumen La investigación sobre biodiversidad es esencial para hacer frente a la crisis mundial de la biodiversidad, por lo que requiere la participación y la variedad de perspectivas de investigadores de diferente procedencia. Sin embargo, la conservación se enfrenta a un importante problema de inclusión, ya que los expertos locales de regiones ricas en biodiversidad, pero con economías desfavorecidas suelen estar infrarrepresentados. Esta infrarrepresentación se debe a prejuicios lingüísticos, contribuciones infravaloradas, prácticas científicas paracaidistas y limitaciones de capacidad. Aunque existen soluciones fragmentadas, se necesita un enfoque unificado de los múltiples actores para abordar los problemas de conservación interconectados y sistémicos. Ideamos un marco holístico de responsabilidad colectiva de todos los participantes en la investigación y estrategias a medida que abarcan la diversidad y desmantelan las barreras sistémicas a la colaboración equitativa. Se necesitan diversos actores y estrategias para promover la inclusión en la investigación sobre biodiversidad, y deben asignarse claramente las responsabilidades de investigadores, editores, instituciones y organismos de financiación. Las estrategias para los investigadores incluyen fomentar la autoconciencia, ampliar las búsquedas bibliográficas, fomentar las asociaciones con expertos locales y promover el intercambio de conocimientos. Para las instituciones, recomendamos establecer funciones de enlace especializadas, aplicar políticas equitativas, asignar recursos a iniciativas de diversidad y mejorar el apoyo a los investigadores internacionales. Las editoriales pueden facilitar la difusión multilingüe, eliminar barreras financieras, establecer normas de inclusión y garantizar una representación equitativa en la revisión por pares. Los financiadores deben eliminar las barreras sistémicas, reforzar las redes de investigación y dar prioridad a la asignación equitativa de recursos. La aplicación de estas estrategias específicas puede ayudar a desmantelar prejuicios profundamente arraigados y desigualdades estructurales en la investigación de la biodiversidad, catalizando un cambio hacia un modelo más inclusivo y representativo que amplifique las diversas perspectivas y maximice el conocimiento colectivo para una conservación global eficaz.

Using citizen science data for predicting the timing of ecological phenomena across regions.

The scarcity of long-term observational data has limited the use of statistical or machine-learning techniques for predicting intraannual ecological variation. However, time-stamped citizen-science observation records, supported by media data such as photographs, are increasingly available. In the present article, we present a novel framework based on the concept of relative phenological niche, using machine-learning algorithms to model observation records as a temporal sample of environmental conditions in which the represented ecological phenomenon occurs. Our approach accurately predicts the temporal dynamics of ecological events across large geographical scales and is robust to temporal bias in recording effort. These results highlight the vast potential of citizen-science observation data to predict ecological phenomena across space, including in near real time. The framework is also easily applicable for ecologists and practitioners already using machine-learning and statistics-based predictive approaches.

Overcoming the Tropical Andes publication divide: Insights from local researchers on challenges and solutions.

The Tropical Andes, one of the world's most biodiverse regions, is vital for ecological research and conservation. However, while researchers in Bolivia, Ecuador, and Peru contribute significantly to scientific knowledge, their publication rates in academic journals have historically lagged behind neighboring nations. A multifaceted strategy was employed to understand and address the publication divide in the Tropical Andes region. This approach focused on regional researchers and consisted of a three-day workshop to improve scientific writing skills, offer publication insights, and equip researchers with tools to overcome obstacles. A series of surveys were also conducted to explore the challenges faced by local researchers and their proposed solutions, covering topics such as participant demographics, factors contributing to lower publication rates, personal barriers, proposed strategies for improving publications, specific topics of interest, participant satisfaction, most valuable workshop topics, and future recommendations. The workshop had an overwhelming response, with over 500 interested participants registering in just a few days, mostly experienced professionals, highlighting the need for such initiatives in the region. About two-thirds had ready-to-publish materials, highlighting the potential impact of targeted interventions on unlocking untapped knowledge. The surveys revealed the challenges contributing to the publication divide, including insufficient training, cultural emphasis on economic development, language barriers, limited resource access, lack of institutional support, high publishing costs, and time and financial constraints. The most common personal barriers were insufficient knowledge and experience in the publication process, lack of self-confidence, and fears of rejection. Proposed solutions include conducting training workshops, fostering collaborative networks, improving resource accessibility, and an institutional and cultural shift that encourages publishing. Addressing challenges faced by experienced professionals in the Tropical Andes by understanding individual needs, fostering support, and demystifying the publication process offers a promising path to closing the publication divide and unlocking the region's valuable scientific contributions.

Using the reactive/transport dispersive models to simulate a monolithic anion exchanger: Experimental parameter determination, simultaneous model evaluation, and validation.

Selecting an adequate model to represent the mass transfer mechanisms occurring in a chromatographic process is generally complicated, which is one of the reasons why monolithic chromatography is scarcely simulated. In this study, the chromatographic separation of model proteins bovine serum albumin (BSA), ß-lactoglobulin-A, and ß-lactoglobulin-B on an anion exchange monolith was simulated based on experimental parameter determination, simultaneous model testing, and validation under three statistical criteria: retention time, dispersion accuracies, and Pearson correlation coefficient. Experimental characterization of morphologic, physicochemical, and kinetic parameters was performed through volume balances, pressure drop analysis, breakthrough curve analysis, and batch adsorptions. Free Gibbs energy indicated a spontaneous adsorption process for proteins and counterions. Dimensionless numbers were estimated based on height equivalent to a theoretical plate analysis, finding that pore diffusion controlled ß-lactoglobulin separation, whereas adsorption/desorption kinetics was the dominant mechanism for BSA. The elution profiles were modeled using the transport dispersive model and the reactive dispersive model coupled with steric mass action (SMA) isotherms because these models allowed to consider most of the mass transport mechanisms that have been described. RDM-SMA presented the most accurate simulations at pH 6.0 and at low (250 mM) and high (400 mM) NaCl concentrations. This simulation will be used as reference to forecast the purification of these proteins from bovine whey waste and to extrapolate this methodology to other monolith-based separations using these three statistical criteria that have not been used previously for this purpose.

Threat of mining to African great apes.

The rapid growth of clean energy technologies is driving a rising demand for critical minerals. In 2022 at the 15th Conference of the Parties to the Convention on Biological Diversity (COP15), seven major economies formed an alliance to enhance the sustainability of mining these essential decarbonization minerals. However, there is a scarcity of studies assessing the threat of mining to global biodiversity. By integrating a global mining dataset with great ape density distribution, we estimated the number of African great apes that spatially coincided with industrial mining projects. We show that up to one-third of Africa's great ape population faces mining-related risks. In West Africa in particular, numerous mining areas overlap with fragmented ape habitats, often in high-density ape regions. For 97% of mining areas, no ape survey data are available, underscoring the importance of increased accessibility to environmental data within the mining sector to facilitate research into the complex interactions between mining, climate, biodiversity, and sustainability.

Saccharomyces cerevisiae biofactory to produce naringenin using a systems biology approach and a bicistronic vector expression strategy in flavonoid production.

IMPORTANCE: Flavonoids are a group of compounds generally produced by plants with proven biological activity, which have recently beeen recommended for the treatment and prevention of diseases and ailments with diverse causes. In this study, naringenin was produced in adequate amounts in yeast after in silico design. The four genes of the involved enzymes from several organisms (bacteria and plants) were multi-expressed in two vectors carrying each two genes linked by a short viral peptide sequence. The batch kinetic behavior of the product, substrate, and biomass was described at lab scale. The engineered strain might be used in a more affordable and viable bioprocess for industrial naringenin procurement.

pH-Responsive Chitosan-Doped ZnO Hybrid Hydrogels for the Encapsulation of Bioactive Compounds in Aquaculture.

In this study, we synthesized and characterized pH-responsive Chitosan-AgCl-doped ZnO hybrid hydrogels and evaluated their potential for loading aquaculture bioactive compounds, and assessed their antimicrobial properties against a threatening pathogen associated with disease across a broad spectrum of warm water fish and invertebrates. Hydrogel characterization consisted of assessing morphology via SEM, composition via EDS, hydrogels' network components interactions via FT-IR and pH response through swelling behavior determinations. The swelling characterization of the synthesized hydrogels demonstrated a pH-responsive behavior, showing that low pH values caused the hydrogel polymeric network to expand and capture more of the aqueous solution. These characteristics make the synthesized hydrogels suitable for the encapsulation and controlled release of drugs and bioactive compounds in aquaculture. Chitosan_ZnO hybrid hydrogels showed great antimicrobial activity against Vibrio harveyi, even better than that of loaded PB hydrogels. Here, we provide evidence for the potential capacity of Chitosan_ZnO hybrid hydrogels for the preventive and curative treatment of diseases that impact aquaculture animal health and prevent drug resistance by bacteria.

A monolithic stationary phase with dendritic nanostructures for the separation of PEGylated proteins.

Separation of PEGylated protein mixtures into individual species is a challenging procedure, and many efforts have been focused on creating novel chromatographic supports for this purpose. In this study, a new monolithic stationary phase with hyperbranched nanostructures was chemically synthesized. For this, monoliths with a support matrix of poly (glycidyl methacrylate-co-ethylene dimethacrylate) and ethylenediamine chemistry were modified with third-generation dendrons with butyl-end groups. The new monolith was analyzed by infrared spectroscopy, confirming the dendron with butyl ligands and exhibited low mass transfer resistance as observed by breakthrough frontal analysis. This support was able to separate mono-PEG ribonuclease A from the PEGylation mixture, indicated by a single band (∼30 kDa) in the electrophoretic analysis. Moreover, the separation of mono-PEGylated positional isomers was probably observed, as the protein with ∼30 kDa was found in two separate peaks. Interestingly, the dendronized monolith allowed the separation of the reaction mixture into individual PEGylated species when using high ammonium sulfate concentrations (2 M). A correlation between the PEGylation degree and the strength of the hydrophobic interactions on the monolith was observed. This chromatographic approach combines the natural branched architecture of dendrons and the higher capabilities of the monoliths enhancing the hydrophobic surface area, and therefore the interaction between the PEGylated proteins and ligands. Thus, the novel support represents a novel platform for the purification of PEGylated from non-PEGylated proteins with biotechnological applications.

iCLOTS: open-source, artificial intelligence-enabled software for analyses of blood cells in microfluidic and microscopy-based assays.

While microscopy-based cellular assays, including microfluidics, have significantly advanced over the last several decades, there has not been concurrent development of widely-accessible techniques to analyze time-dependent microscopy data incorporating phenomena such as fluid flow and dynamic cell adhesion. As such, experimentalists typically rely on error-prone and time-consuming manual analysis, resulting in lost resolution and missed opportunities for innovative metrics. We present a user-adaptable toolkit packaged into the open-source, standalone Interactive Cellular assay Labeled Observation and Tracking Software (iCLOTS). We benchmark cell adhesion, single-cell tracking, velocity profile, and multiscale microfluidic-centric applications with blood samples, the prototypical biofluid specimen. Moreover, machine learning algorithms characterize previously imperceptible data groupings from numerical outputs. Free to download/use, iCLOTS addresses a need for a field stymied by a lack of analytical tools for innovative, physiologically-relevant assays of any design, democratizing use of well-validated algorithms for all end-user biomedical researchers who would benefit from advanced computational methods.

Novel Technologies for Exosome and Exosome-like Nanovesicle Procurement and Enhancement.

Exosomes are extracellular nanovesicles commonly produced by mammalian cells that in recent years have risen as a novel strategy for drug delivery systems and cancer therapy because of their innate specificity and high bioavailability. However, there are limitations that undermine their potential. Among them is the lack of mass production capacity with the current available sources and the failure to reach the intended therapeutic effect because of their insufficient uptake or their rapid clearance once administered. This review aims to show the current advances in overcoming these limitations by presenting, firstly, reported strategies to improve exosome and exosome-like nanovesicle extraction from possible novel eukaryotic sources, including animals, plants, and protozoa; and secondly, alternative modification methods that functionalize exosomes by conferring them higher targeting capacity and protection from organism defenses, which results in an increase in the attachment of ligands and cellular uptake of inorganic materials. However, even when these strategies might address some of the obstacles in their procurement and therapeutic use, there are still several aspects that need to be addressed, so several perspectives of the matter are also presented and analyzed throughout this work.

Design and Assembly of a Biofactory for (2S)-Naringenin Production in Escherichia coli: Effects of Oxygen Transfer on Yield and Gene Expression.

The molecule (2S)-naringenin is a scaffold molecule with several nutraceutical properties. Currently, (2S)-naringenin is obtained through chemical synthesis and plant isolation. However, these methods have several drawbacks. Thus, heterologous biosynthesis has emerged as a viable alternative to its production. Recently, (2S)-naringenin production studies in Escherichia coli have used different tools to increase its yield up to 588 mg/L. In this study, we designed and assembled a bio-factory for (2S)-naringenin production. Firstly, we used several parametrized algorithms to identify the shortest pathway for producing (2S)-naringenin in E. coli, selecting the genes phenylalanine ammonia lipase (pal), 4-coumarate: CoA ligase (4cl), chalcone synthase (chs), and chalcone isomerase (chi) for the biosynthetic pathway. Then, we evaluated the effect of oxygen transfer on the production of (2S)-naringenin at flask (50 mL) and bench (4 L culture) scales. At the flask scale, the agitation rate varied between 50 rpm and 250 rpm. At the bench scale, the dissolved oxygen was kept constant at 5% DO (dissolved oxygen) and 40% DO, obtaining the highest (2S)-naringenin titer (3.11 ± 0.14 g/L). Using genome-scale modeling, gene expression analysis (RT-qPCR) of oxygen-sensitive genes was obtained.

Production and purification of bacterial membrane vesicles for biotechnology applications: Challenges and opportunities.

Bacterial membrane vesicles (BMVs) are bi-layered nanostructures derived from Gram-negative and Gram-positive bacteria. Among other pathophysiological roles, BMVs are critical messengers in intercellular communication. As a result, BMVs are emerging as a promising technology for the development of numerous therapeutic applications. Despite the remarkable progress in unveiling BMV biology and functions in recent years, their successful isolation and purification have been limited. Several challenges related to vesicle purity, yield, and scalability severely hamper the further development of BMVs for biotechnology and clinical applications. This review focuses on the current technologies and methodologies used in BMV production and purification, such as ultracentrifugation, density-gradient centrifugation, size-exclusion chromatography, ultrafiltration, and precipitation. We also discuss the current challenges related to BMV isolation, large-scale production, storage, and stability that limit their application. More importantly, the present work explains the most recent strategies proposed for overcoming those challenges. Finally, we summarize the ongoing applications of BMVs in the biotechnological field.

HIV Stigma Mechanisms Scale: Factor Structure, Reliability, and Validity in Mexican Adults.

We aimed to validate the HIV Stigma Mechanisms Scale (HIV-SMS) in a sample of Mexican adults living with HIV, which differentiates between sources and mechanisms of stigma. Adults (n = 362) with a median age of 32 years old completed a web-based version in Spanish of the HIV-SMS as well as sociodemographic and HIV-related characteristics questionnaire. Exploratory factor analyses with weighted least squares and oblique rotation were performed to assess the construct validity of the scale. The Spanish translation for the Mexican population of the HIV-SMS has adequate internal consistency (Ω = 0.86) and demonstrated a structure similar to the original scale. After excluding the items related to community and social workers, a five-factor solution with internalized, promulgated, and anticipated stigma from family and healthcare workers showed adequate construct validity. The HIV-SMS is a valid and sensitive scale that can be used in a Mexican adult population living with HIV.

RESUMEN: El objetivo de este estudio fue validar la Escala de Mecanismos de Estigma de VIH (EME-VIH) en una muestra de adultos mexicanos que viven con VIH. Esta escala distingue entre fuentes y mecanismos de estigma. 362 adultos con una edad media de 32 años completaron vía web una versión en español de la EME-VIH así como preguntas acerca de sus características sociodemográficas y cuestiones relacionadas con el VIH. Se realizaron análisis factoriales exploratorios de mínimos cuadrados ponderados con rotación oblicua para evaluar la validez de constructo de la escala. La traducción al español de la EME-VIH para población mexicana tiene consistencia interna adecuada (Ω = 0.86) y muestra una estructura similar a la escala original. Después de excluir los ítems relacionados con trabajadores comunitarios y sociales, se encontró una solución con validez de constructo adecuada de cinco factores: estigma internalizado, promulgado y anticipado ejercido por la familia y personal de salud. La EME-VIH es una escala válida y sensible que puede usarse en población adulta mexicana que vive con VIH.

Development of an Adaptive Acquisition and Transmission System for Digital Processing of ECG Signals under Variable n-QAM Schemes / Desarrollo de un Sistema Adaptativo de Adquisición y Transmisión para el Procesamiento Digital de Señales de ECG Bajo Esquemas Variables n-QAM

Abstract In the post-pandemic era, it is critical to monitor and transmit biomedical signals, specifically ECG. This study aims to develop a platform that enables signal acquisition, adaptation, and transmission using different n-QAM modulation schemes. The system comprises an acquisition stage implemented in the 2.5 GHz band employing the Olimex module and electrodes equipped with an Ag/AgCl type sensor. To effectively manage appropriate bandwidths during implementation of the various n-QAM modulation schemes, an adaptive algorithm was developed and applied to the system. The power amplifier was operated in the linear region to enhance the crest factor and achieve an ACPR close to 30 dBc, demonstrating an appropriate demodulation of the electrocardiogram (ECG) signal, it is feasible to shift to modulation schemes above 64-QAM in order to detect high frequencies and perform a subsequent Fourier analysis. As a telemedicine proposal, the developed system offers flexibility in signal acquisition, data storage, and digitalization, in addition to a multivariable n-QAM scheme; the hardware implementation ensures n-QAM scheme compatibility. For the purpose of contributing to telemedicine via RF transmission, the system was executed on an AD9361 transceiver, which removes the requirement for a traditional signal vector generator and enables optimal control of the tones to be transmitted.

Resumen El monitoreo y transmisión de señales biomédicas, particularmente ECG, es fundamental en la era pospandemia, este trabajo de investigación se centra en el desarrollo de una plataforma para la adquisición, adaptación y transmisión de señales bajo diversos esquemas de modulación n-QAM. El sistema incluye una etapa de adquisición mediante el módulo Olimex y electrodos con un sensor tipo Ag/AgCl. Se desarrolló un algoritmo adaptativo a los diversos esquemas de modulación n-QAM para la gestión de anchos de banda apropiados durante una implementación en la banda de 2,5 GHz, al amplificador de potencia se operó en la región lineal para mejorar el factor de cresta y obtener un ACPR cercano a 30 dBc, se realizó una demodulación adecuada de la señal ECG y es posible migrar a esquemas de modulación superiores a 64-QAM si se requiere detectar altas frecuencias y un posterior análisis de Fourier. El sistema desarrollado como propuesta de Telemedicina brinda versatilidad para la adquisición de señales, digitalización, almacenamiento de datos y un esquema multivariable n-QAM, la implementación en hardware proporcionó una adecuada adaptabilidad para esquemas n-QAM. El sistema se implementó sobre un transceptor AD9361 que elimina el tradicional generador vectorial de señal y permite un control óptimo de los tonos a enviar, para aporte en el área de Telemedicina a través de transmisión RF.

A Comparison of Surrogate Behavioral Models for Power Amplifier Linearization under High Sparse Data.

A good approximation to power amplifier (PA) behavioral modeling requires precise baseband models to mitigate nonlinearities. Since digital predistortion (DPD) is used to provide the PA linearization, a framework is necessary to validate the modeling figures of merit support under signal conditioning and transmission restrictions. A field-programmable gate array (FPGA)-based testbed is developed to measure the wide-band PA behavior using a single-carrier 64-quadrature amplitude modulation (QAM) multiplexed by orthogonal frequency-division multiplexing (OFDM) based on long-term evolution (LTE) as a stimulus, with different bandwidths signals. In the search to provide a heuristic target approach modeling, this paper introduces a feature extraction concept to find an appropriate complexity solution considering the high sparse data issue in amplitude to amplitude (AM-AM) and amplitude to phase AM-PM models extraction, whose penalties are associated with overfitting and hardware complexity in resulting functions. Thus, experimental results highlight the model performance for a high sparse data regime and are compared with a regression tree (RT), random forest (RF), and cubic-spline (CS) model accuracy capabilities for the signal conditioning to show a reliable validation, low-complexity, according to the peak-to-average power ratio (PAPR), complementary cumulative distribution function (CCDF), coefficients extraction, normalized mean square error (NMSE), and execution time figures of merit. The presented models provide a comparison with original data that aid to compare the dimension and robustness for each surrogate model where (i) machine learning (ML)-based and (ii) CS interpolate-based where high sparse data are present, NMSE between the CS interpolated based are also compared to demonstrate the efficacy in the prediction methods with lower convergence times and complexities.

Characterization and optimization of polymer-polymer aqueous two-phase systems for the isolation and purification of CaCo2 cell-derived exosomes.

Exosomes are cell-derived vesicles that present attractive characteristics such as nano size and unique structure for their use as drug delivery systems for drug therapy, biomarkers for prognostic, diagnostic and personalized treatments. So far, one of the major challenges for therapeutic applications of exosomes is the development of optimized isolation methods. In this context, aqueous two-phase systems (ATPS) have been used as an alternative method to isolate biological molecules and particles with promising expectations for exosomes. In this work, fractionation of exosomes obtained from CaCo2 cell line and culture media contaminants were individually performed in 20 polymer-polymer ATPS. The effect of design parameters such as polymer composition, molecular weight, and tie-line length (TLL) on polyethylene glycol (PEG)-Dextran, Dextran-Ficoll and PEG-Ficoll systems was studied. After partition analysis, 4 of the 20 systems presented the best exosome fractionation from contaminants under initial conditions, which were optimized via salt addition (NaCl) to a final concentration of 25 mM, to improve collection efficiency. The PEG 10,000 gmol-1 -Dextran 10,000 gmol-1 system at TLL 25% w/w with NaCl, showed the best potential isolation efficiency. Following this proposed strategy, an exosome purification factor of 2 in the top PEG-rich phase can be expected furtherly demonstrating that ATPS have the potential for the selective recovery of these promising nanovesicles.

State-of-the-Art and Opportunities for Bioactive Pentacyclic Triterpenes from Native Mexican Plants.

Native Mexican plants are a wide source of bioactive compounds such as pentacyclic triterpenes. Pentacyclic triterpenes biosynthesized through the mevalonate (MVA) and the 2-C-methyl-D-erythritol-phosphate (MEP) metabolic pathways are highlighted by their diverse biological activity. Compounds belonging to the oleanane, ursane, and lupane groups have been identified in about 33 Mexican plants, located geographically in the southwest of Mexico. The works addressing these findings have reported 45 compounds that mainly show antimicrobial activity, followed by anti-inflammatory, cytotoxic, anxiolytic, hypoglycemic, and growth-stimulating or allelopathic activities. Extraction by maceration and Soxhlet with organic solvents and consecutive chromatography of silica gel have been used for their whole or partial purification. Nanoparticles and nanoemulsions are the vehicles used in Mexican formulations for drug delivery of the pentacyclic triterpenes until now. Sustainable extraction, formulation, regulation, isolation, characterization, and bioassay facilities are areas of opportunity in pentacyclic triterpenes research in Mexico while the presence of plant and human resources and traditional knowledge are strengths. The present review discusses the generalities of the pentacyclic triterpene (definition, biogenic classification, and biosynthesis), a summary of the last two decades of research on the compounds identified and their evaluated bioactivity, the generalities about the extraction and purification methods used, drug delivery aspects, and a critical analysis of the advantages and limitations of research carried out in this way.

Substance use stigma mechanisms scale: Factor structure, reliability, and validity in Mexican adults that use drugs.

BACKGROUND: Studies among the Mexican population have suggested that stigma towards persons who use drugs (PWUD) may act as a barrier to treatment seeking and contribute to negative health consequences. However, there has not been a validated scale to measure this construct. This paper aims to validate the Substance Use Stigma Mechanisms Scale (SU-SMS) in a sample of Mexican adults who use drugs. This 18-item scale was developed to differentiate substance use stigma mechanisms and learn their impact on the health and wellbeing of persons who use drugs (PWUD) in the United States. METHODS: A sample of 407 adults with a median age of 27 years old completed a web-based version in Spanish of the SU-SMS, the WHO-ASSIST screening instrument, as well as sociodemographic and substance-use-related characteristics. We performed exploratory factor analysis with weighted least squares and oblique rotation, and correlations within and between mechanisms of stigma, and substance use. RESULTS: The Spanish translation of the SU-SMS has adequate internal consistency (Ω=0.92) and the same factor structure as the original scale. A five-factor solution with internalized, enacted, and anticipated stigma from family and healthcare workers showed adequate concurrent validity. Mechanisms of stigma were correlated between them, within sources, and negatively correlated with current substance use treatment. CONCLUSIONS: The Spanish translation of the scale seems to be a valid and sensitive scale that can be used among Mexican PWUD.

Mono-PEGylated lysozyme purification with increased productivity and isomer differentiation through heparin monolith chromatography.

PEGylated protein purification with the required quality attributes has represented a bioengineering challenge and Affinity Monolith Chromatography (AMC) has never been exploited for this goal. This work reports the generation of a heparin-modified affinity monolith disk by reductive alkylation with raised ligand density for its use as chromatographic support in the separation of lysozyme PEGylation reactions (LPRs) with three different PEG sizes (1, 20 and 40 kDa). For immobilized heparin determination a modified toluidine colorimetric assay adapted to microplate format was proposed. The heparin modified-disk was able to differentiate positional isomers of 20 kDa mono-PEGylated lysozyme at neutral pH using a salt linear gradient. Identity of PEG-conjugates was verified by SDS-PAGE and positional isomers were partially characterized by peptide mapping mass spectrometry. 20 kDa mono-PEGylated lysozyme conjugate purity (99.69 ± 0.05%) was comparable with traditional chromatographic methods while productivity (0.0964 ± 0.0001 mg/mL*min) was increased up to 6.1 times compared to that obtained in heparin packed-bed affinity chromatography procedures. The proposed AMC method represents a reliable, efficient, easy-handling, fast and single-step operation for the analysis or preparative isolation of PEGylated proteins containing a heparin binding domain.

Applying the Global Monitoring Plan and analysis of POPs results in atmospheric air in Mexico (2017-2018).

Air is one of the target matrices of the Global Monitoring Plan (GMP) of the Stockholm Convention to determine concentrations and transport of Persistent Organic Pollutants (POPs). Mexico participates in the GMP for POPs in ambient air through the AIR-Global Environment Facility (GEF) program. The objective of this study was to analyze the results of POPs monitoring of air samples collected in Los Mochis, Sinaloa, Mexico, between 2017 and 2018. Passive samplers were used for the determination of chlorinated basic POPs, indicator polychlorinated biphenyls (Ind. PCBs), polybrominated biphenyl ethers (PBDEs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs). A principal component analysis was applied to determine relationships between pollutants and groups present in the ambient air of the rural study area. Of the total POPs analyzed, 85.56% were detected in ambient air samples from Mexico. Organochlorine compounds, as DDT derivatives, were identified mainly, as well as PBDEs, PCDDs, and PCDFs. The prevalence of compounds differed according to the seasonality of sampling, with no change in average concentration between monitoring years.