New gel from a water-soluble Carboxymethyl chitosan-Cinnamaldehyde Schiff base derivative as an effective preservative against soft rot in ginger.

Ginger, valued for its culinary and medicinal properties, suffers substantial production loss-up to 90 %-due to fungal soft rot. To combat this, we have developed an environmentally sustainable antifungal polysaccharide gel derived from a water-soluble Schiff base of O-carboxymethyl chitosan (CMC) and cinnamaldehyde (CIN). Terpene incorporation was confirmed via various characterization techniques, including Fourier transform infrared (FT-IR), pH-dependent release, solubility, thermogravimetric analysis, and UV-vis spectra. Results showed successful grafting of CIN onto the polysaccharide, at a CIN:CMC ratio of 120 mg/g. In vitro evaluation demonstrated significant antifungal activity against F. oxysporum, with a MIC value of 159.25 µg/mL. Application of the CMC=CIN gel to ginger rhizomes inhibited spore germination in all evaluated wounds, enhancing gloss and appearance. These findings validate the efficacy of this novel, environmentally friendly gel in preventing ginger loss caused by fungal infections.

Molecular Docking-Based Virtual Screening of FDA-Approved Drugs Using Trypanothione Reductase Identified New Trypanocidal Agents.

American trypanosomiasis or Chagas disease, caused by Trypanosoma cruzi (T. cruzi), affects approximately 6-7 million people worldwide. However, its pharmacological treatment causes several uncomfortable side effects, causing patients' treatment abandonment. Therefore, there is a need for new and better treatments. In this work, the molecular docking of nine hundred twenty-four FDA-approved drugs on three different sites of trypanothione reductase of T. cruzi (TcTR) was carried out to find potential trypanocidal agents. Finally, biological evaluations in vitro and in vivo were conducted with the selected FDA-approved drugs. Digoxin, alendronate, flucytosine, and dihydroergotamine showed better trypanocidal activity than the reference drugs benznidazole and nifurtimox in the in vitro evaluation against the trypomastigotes form. Further, these FDA-approved drugs were able to reduce 20-50% parasitemia in a short time in an in vivo model, although with less efficiency than benznidazole. Therefore, the results suggest a combined therapy of repurposed and canonical drugs against T. cruzi infection.

Clinical characteristics and impact on patient-reported outcomes and quality of life of people with ambulatory secondary progressive multiple sclerosis: DISCOVER study.

BACKGROUND: People with secondary progressive multiple sclerosis (pwSPMS) experience increasing disability, which impacts negatively on their health-related quality of life (HRQoL). Our aims were to assess the impact of secondary progressive multiple sclerosis (SPMS) on functional status and HRQoL and describe the clinical profile in this population. METHODS: DISCOVER is an observational, cross-sectional, multicenter study with retrospective data collection in real-world clinical practice in Spain. Sociodemographic and clinical variables, functional and cognitive scales, patient-reported outcomes (PROs), and direct healthcare, and non-healthcare and indirect costs were collected. RESULTS: A total of 297 evaluable pwSPMS with a EDSS score between 3-6.5 participated: 62.3 % were female and 18.9 % had active SPMS. At the study visit, 77 % of them presented an Expanded Disability Scale Score (EDSS) of 6-6.5. Nearly 40 % did not receive any disease-modifying treatment. Regarding the working situation, 61.6 % were inactive due to disability. PROs: 99.3 % showed mobility impairment in EuroQoL-5 Dimensions-5 Levels, and about 60 % reported physical impact on the Multiple Sclerosis Impact Scale-29. Fatigue was present in 76.1 %, and almost 40 % reported anxiety or depression. The Symbol Digit Modalities Test was used to assess cognitive impairment; 80 % of the patients were below the mean score. Participants who presented relapses two years before and had high EDSS scores had a more negative impact on HRQoL. PwSPMS with a negative impact on HRQoL presented a higher cost burden, primarily due to indirect costs. CONCLUSIONS: PwSPMS experience a negative impact on their HRQoL, with a high physical impact, fatigue, cognitive impairment, and a high burden of indirect costs.

Cardiopulmonary Complications after Pulmonary Embolism in COVID-19.

Although pulmonary embolism (PE) is a frequent complication in COVID-19, its consequences remain unknown. We performed pulmonary function tests, echocardiography and computed tomography pulmonary angiography and identified blood biomarkers in a cohort of consecutive hospitalized COVID-19 patients with pneumonia to describe and compare medium-term outcomes according to the presence of PE, as well as to explore their potential predictors. A total of 141 patients (56 with PE) were followed up during a median of 6 months. Post-COVID-19 radiological lung abnormalities (PCRLA) and impaired diffusing capacity for carbon monoxide (DLCOc) were found in 55.2% and 67.6% cases, respectively. A total of 7.3% had PE, and 6.7% presented an intermediate-high probability of pulmonary hypertension. No significant difference was found between PE and non-PE patients. Univariate analysis showed that age > 65, some clinical severity factors, surfactant protein-D, baseline C-reactive protein, and both peak red cell distribution width and Interleukin (IL)-10 were associated with DLCOc < 80%. A score for PCRLA prediction including age > 65, minimum lymphocyte count, and IL-1ß concentration on admission was constructed with excellent overall performance. In conclusion, reduced DLCOc and PCRLA were common in COVID-19 patients after hospital discharge, but PE did not increase the risk. A PCRLA predictive score was developed, which needs further validation.

Chaotic Transport of Solutes in Unsaturated Porous Media.

Unsaturated porous media, characterized by the combined presence of several immiscible fluid phases in the pore space, are highly relevant systems in nature, because they control the fate of contaminants and the availability of nutrients in the subsoil. However, a full understanding of the mechanisms controlling solute mixing in such systems is still missing. In particular, the role of saturation in the development of chaotic solute mixing has remained unexplored. Using three-dimensional numerical simulations of flow and transport at the pore scale, built upon X-ray tomograms of a porous medium at different degrees of liquid (wetting)-phase saturation, we show the occurrence of chaotic dynamics in both the deformation of the solute plume, as characterized by computed chaos metrics (Lyapunov exponents), and the mixing of the injected solute. Our results show an enhancement of these chaotic dynamics at lower saturation and their occurrence even under diffusion-relevant conditions over the medium's length, also being strengthened by larger flow velocities. These findings highlight the dominant role of the pore-scale spatial heterogeneity of the system, enhanced by the presence of an immiscible phase (e.g., air), on the mixing efficiency. This represents a stepping stone for the assessment of mixing and reactions in unsaturated porous media.

Trimeric and Tetrameric Cationic Styryl Dyes as Novel Fluorescence and CD Probes for ds-DNA and ds-RNA.

The wide use of mono- or bis-styryl fluorophores in biomedical applications prompted the presented design and study of a series of trimeric and tetrameric homo-analogues, styryl moieties arranged around a central aromatic core. The interactions with the most common biorelevant targets, ds-DNA and ds-RNA, were studied by a set of spectrophotometric methods (UV-VIS, fluorescence, circular dichroism, thermal denaturation). All studied dyes showed strong light absorption in the 350-420 nm range and strongly Stokes-shifted (+100-160 nm) emission with quantum yields (Φf) up to 0.57, whereby the mentioned properties were finely tuned by the type of the terminal cationic substituent and number of styryl components (tetramers being red-shifted in respect to trimers). All studied dyes strongly interacted with ds-DNA and ds-RNA with 1-10 nM-1 affinity, with dye emission being strongly quenched. The tetrameric analogues did not show any particular selectivity between ds-DNA or ds-RNA due to large size and consequent partial, non-selective insertion into DNA/RNA grooves. However, smaller trimeric styryl series showed size-dependent selective stabilization of ds-DNA vs. ds-RNA against thermal denaturation and highly selective or even specific recognition of several particular ds-DNA or ds-RNA structures by induced circular dichroism (ICD) bands. The chiral (ICD) selectivity was controlled by the size of a terminal cationic substituent. All dyes entered efficiently live human cells with negligible cytotoxic activity. Further prospects in the transfer of ICD-based selectivity into fluorescence-chiral methods (FDCD and CPL) is proposed, along with the development of new analogues with red-shifted absorbance properties.

Oligo(styryl)benzenes liposomal AIE-dots for bioimaging and phototherapy in an in vitro model of prostate cancer.

Whilst the development of advanced organic dots with aggregation-induced emission characteristics (AIE-dots) is being intensively studied, their clinical translation in efficient biotherapeutic devices has yet to be tackled. This study explores the synergistic interplay of oligo(styryl)benzenes (OSBs), potent fluorogens with an increased emission in the aggregate state, and Indocyanine green (ICG) as dual Near Infrared (NIR)-visible fluorescent nanovesicles with efficient reactive oxygen species (ROS) generation capacity for cancer treatment using photodynamic therapy (PDT). The co-loading of OSBs and ICG in different nanovesicles has been thoroughly investigated. The nanovesicles' physicochemical properties were manipulated via molecular engineering by modifying the structural properties of the lipid bilayer and the number of oligo(ethyleneoxide) chains in the OSB structure. Diffusion Ordered Spectroscopy (DOSY) NMR and spectrofluorometric studies revealed key differences in the structure of the vesicles and the arrangement of the OSB and ICG in the bilayer. The in vitro assessment of these OSB-ICG nanovesicles revealed that the formulations can increase the temperature and generate ROS after photoirradiation, showing for the first time their potential as dual photothermal/photodynamic (PTT/PDT) agents in the treatment of prostate cancer. Our study provides an exciting opportunity to extend the range of applications of OSB derivates to potentiate the toxicity of phototherapy in prostate and other types of cancer.

Multiscale Porosity Microfluidics to Study Bacterial Transport in Heterogeneous Chemical Landscapes.

Microfluidic models are proving to be powerful systems to study fundamental processes in porous media, due to their ability to replicate topologically complex environments while allowing detailed, quantitative observations at the pore scale. Yet, while porous media such as living tissues, geological substrates, or industrial systems typically display a porosity that spans multiple scales, most microfluidic models to date are limited to a single porosity or a small range of pore sizes. Here, a novel microfluidic system with multiscale porosity is presented. By embedding polyacrylamide (PAAm) hydrogel structures through in-situ photopolymerization in a landscape of microfabricated polydimethylsiloxane (PDMS) pillars with varying spacing, micromodels with porosity spanning several orders of magnitude, from nanometers to millimeters are created. Experiments conducted at different porosity patterns demonstrate the potential of this approach to characterize fundamental and ubiquitous biological and geochemical transport processes in porous media. Accounting for multiscale porosity allows studies of the resulting heterogeneous fluid flow and concentration fields of transported chemicals, as well as the biological behaviors associated with this heterogeneity, such as bacterial chemotaxis. This approach brings laboratory studies of transport in porous media a step closer to their natural counterparts in the environment, industry, and medicine.

Pulmonary thrombosis associated with COVID-19 pneumonia: Beyond classical pulmonary thromboembolism.

BACKGROUND: Classical pulmonary thromboembolism (TE) and local pulmonary thrombosis (PT) have been suggested as mechanisms of thrombosis in COVID-19. However, robust evidence is still lacking because this was mainly based on retrospective studies, in which patients were included when TE was suspected. METHODS: All patients with COVID-19 pneumonia underwent computed tomography and pulmonary angiography in a prospective study. The main objective was to determine the number and percentage of thrombi surrounded by lung opacification (TSO) in each patient, as well as their relationship with percentage of lung involvement (TLI), to distinguish classical TE (with a random location of thrombi that should correspond to a percentage of TSO equivalent to the TLI) from PT. We determined TLI by artificial intelligence. Analyses at patient level (TLI and percentage of TSO) and at thrombi level (TLI and TSO) were performed. RESULTS: We diagnosed TE in 70 out of 184 patients. Three (2-8) thrombi/patient were detected. The percentage of TSO was 100% (75-100) per patient, and TLI was 19.9% (4.6-35.2). Sixty-five patients (92.9%) were above the random scenario with higher percentage of TSO than TLI. Most thrombi were TSO (n = 299, 75.1%). When evaluating by TLI (<10%, 10%-20%, 20%-30% and >30%), percentage of TSO was higher in most groups. Thrombi were mainly in subsegmental/segmental arteries, and percentage of TSO was higher in all locations. CONCLUSIONS: Thrombi in COVID-19 were found within lung opacities in a higher percentage than lung involvement, regardless of TLI and clot location, supporting the hypothesis of local PT rather than "classic TE".

The Molecular Role of Polyamines in Age-Related Diseases: An Update.

Polyamines (Pas) are short molecules that exhibit two or three amine groups that are positively charged at a physiological pH. These small molecules are present in high concentrations in a wide variety of organisms and tissues, suggesting that they play an important role in cellular physiology. Polyamines include spermine, spermidine, and putrescine, which play important roles in age-related diseases that have not been completely elucidated. Aging is a natural process, defined as the time-related deterioration of the physiological functions; it is considered a risk factor for degenerative diseases such as cardiovascular, neurodegenerative, and musculoskeletal diseases; arthritis; and even cancer. In this review, we provide a new perspective on the participation of Pas in the cellular and molecular processes related to age-related diseases, focusing our attention on important degenerative diseases such as Alzheimerߣs disease, Parkinsonߣs disease, osteoarthritis, sarcopenia, and osteoporosis. This new perspective leads us to propose that Pas function as novel biomarkers for age-related diseases, with the main purpose of achieving new molecular alternatives for healthier aging.

Polyamines modulate mouse sperm motility.

Polyamines are polycationic molecules which contains two or more amino groups (-NH3+) highly charged at physiological pH, and among them we found spermine, spermidine, putrescine, and cadaverine. They interact with proteins, nucleic acids, modulate Ca2+, K+, and Na+ channels, and protect sperm from oxidative stress. In this work, we evaluate the effect of spermine, spermidine, and putrescine on the total, progressive and kinematic parameters of motility, capacitation, acrosome reaction, also in presence and absence of the dbcAMP, an analogue of the cAMP, and the IBMX, a phosphodiesterase inhibitor. In addition, we evaluated the intracellular concentrations of cAMP [cAMP]i, and performed an in silico analysis between polyamines and the sAC from mouse to predict the possible interaction among them. Our results showed that all polyamines decrease drastically the total, progressive and the kinetic parameters of sperm motility, decrease the capacitation, and only spermidine and putrescine impeded the acquisition of acrosome reaction. Moreover, the effect of polyamines was attenuated but not countered by the addition of db-cAMP and IBMX, suggesting a possible inhibition of the sAC. Also, the presence of polyamines induced a decrease of the [cAMP]i, and the in silico analysis predicted a strong interaction among polyamines and the sAC. Overall, the evidence suggests that probably the polyamines interact and inhibit the activity of the sAC.

From the Mental to the Conceptual Model: The Challenge of Teaching Hydrogeology in the Field.

Field-based learning in hydrogeology enables students to develop their understanding and application of practical methodologies, and to enhance many of the generic skills (e.g., teamwork, problem-solving). However, teaching and learning hydrogeology in general, and especially in the field, presents cognitive difficulties, such as the diversity in student education and experience, the hidden nature of water movement and transport of chemicals, and the preexisting students' mental models of the subsurface, in particular. At any given experimental or teaching site there is only one reality for which lecturers can have an approximate conceptual model, including aquifer(s) geometry and functioning (e.g., flow direction). However, students' preconceptions (i.e., mental model), in some cases misconceptions, influence not only their outcome from the learning strategy designed, but also the conceptual model expression (i.e., flow chart, block diagram, or similar) for the study area or site. In practice, two general "teaching challenges" are identified to enable students' transition from the mental to the conceptual model: (1) identify and dispel any prior misconceptions and (2) show how to go from the partial information to the integration of new information for the development of the conceptual model. The inclusion of specific prior-to-field lessons in the classroom is recommended and in general, done. However, introducing a prior-to-field survey to learn about students' backgrounds, and methodologies for the development and expression of hydrogeological conceptual models and for testing multiple plausible conceptual models will help students transition from the mental to the conceptual model.

Antibacterial Cu or Zn-MOFs Based on the 1,3,5-Tris-(styryl)benzene Tricarboxylate.

Metal-organic frameworks (MOFs) are highly versatile materials. Here, two novel MOFs, branded as IEF-23 and IEF-24 and based on an antibacterial tricarboxylate linker and zinc or copper cations, and holding antibacterial properties, are presented. The materials were synthesized by the solvothermal route and fully characterized. The antibacterial activity of IEF-23 and IEF-24 was investigated against Staphylococcus epidermidis and Escherichia coli via the agar diffusion method. These bacteria are some of the most broadly propagated pathogens and are more prone to the development of antibacterial resistance. As such, they represent an archetype to evaluate the efficiency of novel antibacterial treatments. MOFs were active against both strains, exhibiting higher activity against Staphylococcus epidermidis. Thus, the potential of the developed MOFs as antibacterial agents was proved.

Quantifying the available capacity and resource needs for provision of CAR-T therapies in the National Health Service in Spain: a survey-based study.

OBJECTIVES: To estimate the readiness of Spanish National Health Service (NHS) hospitals to provide chimeric antigen receptor T cell (CAR-T), and to identify and quantify the different resources needed to provide CAR-T considering three scenarios defined by 10, 25 and 50 patients per centre per year. DESIGN: Targeted literature review and quantitative study using a questionnaire and telephone interviews. An algorithm was created to determine hospitals' readiness based on their capacity and capability. All the requirements for quantification were assessed and validated by the steering committee, formed by members of the Spanish Group of Haematopoietic Transplantation and Cell Therapy. A weighting system (from 0 to 1) was established for capability quantification. For resources quantification, a scoring system was established, with 0 points representing the minimum and 3 points the maximum of additional resources that a hospital indicated necessary. SETTING: 40 Spanish hospital centres that perform allogeneic haematopoietic stem cell transplantation were invited to complete the questionnaire for capacity quantification, 28 of which provided valid responses. Nine hospitals participated in the interviews for resource quantification, eight of which had previously been designated by the Ministry of Health (MoH) to provide CAR-T. OUTCOME MEASURE: Current capacity of NHS Spanish sites to administer CAR-T under different theoretical scenarios with varying numbers of procedures, and the potential healthcare resources that would be needed to realise the theoretical capacity requirements. RESULTS: Four hospitals were optimally ready, 17 were somewhat ready and 7 were not ready. The actual extrapolated capacity of the currently designated MoH CAR-T sites would allow treatment of approximately 250 patients per year. Regarding healthcare resource needs, the numbers of haematologists, nurses and beds were the most important limiting factors, and those requiring further growth as patient numbers increased. CONCLUSIONS: Increasing the number of CAR-T-qualified centres and/or increasing resources in the current designated sites are two potential strategies that should be considered to treat CAR-T-eligible patients in Spain.

Fluorescent and Magnetic Radical Dendrimers as Potential Bimodal Imaging Probes.

Dual or multimodal imaging probes have emerged as powerful tools that improve detection sensitivity and accuracy in disease diagnosis by imaging techniques. Two imaging techniques that are complementary and do not use ionizing radiation are magnetic resonance imaging (MRI) and optical fluorescence imaging (OFI). Herein, we prepared metal-free organic species based on dendrimers with magnetic and fluorescent properties as proof-of-concept of bimodal probes for potential MRI and OFI applications. We used oligo(styryl)benzene (OSB) dendrimers core that are fluorescent on their own, and TEMPO organic radicals anchored on their surfaces, as the magnetic component. In this way, we synthesized six radical dendrimers and characterized them by FT-IR, 1H NMR, UV-Vis, MALDI-TOF, SEC, EPR, fluorimetry, and in vitro MRI. Importantly, it was demonstrated that the new dendrimers present two properties: on one hand, they are paramagnetic and show the ability to generate contrast by MRI in vitro, and, on the other hand, they also show fluoresce emission. This is a remarkable result since it is one of the very few cases of macromolecules with bimodal magnetic and fluorescent properties using organic radicals as the magnetic probe.

Global warming accelerates soil heterotrophic respiration.

Carbon efflux from soils is the largest terrestrial carbon source to the atmosphere, yet it is still one of the most uncertain fluxes in the Earth's carbon budget. A dominant component of this flux is heterotrophic respiration, influenced by several environmental factors, most notably soil temperature and moisture. Here, we develop a mechanistic model from micro to global scale to explore how changes in soil water content and temperature affect soil heterotrophic respiration. Simulations, laboratory measurements, and field observations validate the new approach. Estimates from the model show that heterotrophic respiration has been increasing since the 1980s at a rate of about 2% per decade globally. Using future projections of surface temperature and soil moisture, the model predicts a global increase of about 40% in heterotrophic respiration by the end of the century under the worst-case emission scenario, where the Arctic region is expected to experience a more than two-fold increase, driven primarily by declining soil moisture rather than temperature increase.

Internal Biofilm Heterogeneities Enhance Solute Mixing and Chemical Reactions in Porous Media.

Bacterial biofilms can form in porous media that are of interest in industrial applications ranging from medical implants to biofilters as well as in environmental applications such as in situ groundwater remediation, where they can be critical locations for biogeochemical reactions. The presence of biofilms modifies porous media topology and hydrodynamics by clogging pores and consequently solutes transport and reactions kinetics. The interplay between highly heterogeneous flow fields found in porous media and microbial behavior, including biofilm growth, results in a spatially heterogeneous biofilm distribution in the porous media as well as internal heterogeneity across the thickness of the biofilm. Our study leverages highly resolved three-dimensional X-ray computed microtomography images of bacterial biofilms in a tubular reactor to numerically compute pore-scale fluid flow and solute transport by considering multiple equivalent stochastically generated internal permeability fields for the biofilm. We show that the internal heterogeneous permeability mainly impacts intermediate velocities when compared with homogeneous biofilm permeability. While the equivalent internal permeability fields of the biofilm do not impact fluid-fluid mixing, they significantly control a fast reaction. For biologically driven reactions such as nutrient or contaminant uptake by the biofilm, its internal permeability field controls the efficiency of the process. This study highlights the importance of considering the internal heterogeneity of biofilms to better predict reactivity in industrial and environmental bioclogged porous systems.

Remission of lupus nephritis: the trajectory of histological response in successfully treated patients.

OBJECTIVE: This study investigated changes in kidney histology over time in patients with lupus nephritis (LN) undergoing immunosuppressive treatment. METHODS: Patients with proliferative±membranous LN were studied. After a diagnostic kidney biopsy (Bx1), patients had protocol biopsy 2 (Bx2) at 9 (6-15) months and protocol biopsy 3 (Bx3) at 42 (28-67) months. Kidney histological activity and chronicity indices (AI, CI) were measured. RESULTS: AI declined in a biphasic fashion, falling rapidly between Bx1 and Bx2 and then more slowly between Bx2 and Bx3. Patients were divided into those who achieved histological remission, defined as an AI=0 at Bx3 (group 1), and those with persistent histological activity (AI >0) at Bx3 (group 2). The early decline in AI was 1.6 times greater (95% CI 1.30, 1.91) in group 1 than group 2 (p=0.01). Between Bx2 and Bx3, the AI decline was 2.19-fold greater (95% CI 2.09, 2.29) in group 1 versus group 2 (p=7.34×10-5). Individual histological components of the AI resolved at different rates. Inflammatory lesions like glomerular crescents, karyorrhexis and necrosis mostly resolved by Bx2, whereas endocapillary hypercellularity, subendothelial hyaline deposits and interstitial inflammation resolved slowly, accounting for residual histological activity at biopsy 3 in group 2. In contrast, CI increased rapidly, by 0.15 units/month between Bx1 and Bx2, then plateaued. There were no differences in the rate of accumulation of chronic damage between group 1 and group 2. The increase in CI was significantly related to the severity of glomerular crescents (p=0.044), subendothelial hyaline deposits (p=0.002) and interstitial inflammation (p=0.015) at Bx1. CONCLUSIONS: LN histological activity takes months to years to resolve, providing a rationale for the need of long-term, well-tolerated maintenance immunosuppression. Despite responding, LN kidneys accrue chronic damage early during treatment. This finding provides an explanation for the association of chronic progressive kidney disease with recurrent episodes of LN.

Morphogenesis of Biofilms in Porous Media and Control on Hydrodynamics.

The functioning of natural and engineered porous media, like soils and filters, depends in many cases on the interplay between biochemical processes and hydrodynamics. In such complex environments, microorganisms often form surface-attached communities known as biofilms. Biofilms can take the shape of clusters, which alter the distribution of fluid flow velocities within the porous medium, subsequently influencing biofilm growth. Despite numerous experimental and numerical efforts, the control of the biofilm clustering process and the resulting heterogeneity in biofilm permeability is not well understood, limiting our predictive abilities for biofilm-porous medium systems. Here, we use a quasi-2D experimental model of a porous medium to characterize biofilm growth dynamics for different pore sizes and flow rates. We present a method to obtain the time-resolved biofilm permeability field from experimental images and use the obtained permeability field to compute the flow field through a numerical model. We observe a biofilm cluster size distribution characterized by a spectrum slope evolving in time between -2 and -1, a fundamental measure that can be used to create spatio-temporal distributions of biofilm clusters for upscaled models. We find a previously undescribed biofilm permeability distribution, which can be used to stochastically generate permeability fields within biofilms. An increase in velocity variance for a decrease in physical heterogeneity shows that the bioclogged porous medium behaves differently than expected from studies on heterogeneity in abiotic porous media.

Calpain Regulates Reactive Oxygen Species Production during Capacitation through the Activation of NOX2 and NOX4.

Capacitation is a series of physiological, biochemical, and metabolic changes experienced by mammalian spermatozoa. These changes enable them to fertilize eggs. The capacitation prepares the spermatozoa to undergo the acrosomal reaction and hyperactivated motility. Several mechanisms that regulate capacitation are known, although they have not been fully disclosed; among them, reactive oxygen species (ROS) play an essential role in the normal development of capacitation. NADPH oxidases (NOXs) are a family of enzymes responsible for ROS production. Although their presence in mammalian sperm is known, little is known about their participation in sperm physiology. This work aimed to identify the NOXs related to the production of ROS in guinea pig and mouse spermatozoa and define their participation in capacitation, acrosomal reaction, and motility. Additionally, a mechanism for NOXs' activation during capacitation was established. The results show that guinea pig and mouse spermatozoa express NOX2 and NOX4, which initiate ROS production during capacitation. NOXs inhibition by VAS2870 led to an early increase in the capacitation and intracellular concentration of Ca2+ in such a way that the spermatozoa also presented an early acrosome reaction. In addition, the inhibition of NOX2 and NOX4 reduced progressive motility and hyperactive motility. NOX2 and NOX4 were found to interact with each other prior to capacitation. This interaction was interrupted during capacitation and correlated with the increase in ROS. Interestingly, the association between NOX2-NOX4 and their activation depends on calpain activation, since the inhibition of this Ca2+-dependent protease prevents NOX2-NOX4 from dissociating and ROS production. The results indicate that NOX2 and NOX4 could be the most important ROS producers during guinea pig and mouse sperm capacitation and that their activation depends on calpain.