A methodology for numerically analysing the hepatic artery haemodynamics during B-TACE: a proof of concept

Balloon-occluded transarterial chemoembolisation (B-TACE) is an intraarterial transcatheter treatment for liver cancer. In B-TACE, an artery-occluding microballoon catheter occludes an artery and promotes collateral circulation for drug delivery to tumours. This paper presents a methodology for analysing the haemodynamics during B-TACE, by combining zero-dimensional and three-dimensional modelling tools. As a proof of concept, we apply the methodology to a patient-specific hepatic artery geometry and analyse two catheter locations. Results show that the blood flow redistribution can be predicted in this proof-of-concept study, suggesting that this approach could potentially be used to optimise catheter location.     

Structural and functional responses of invertebrate communities to climate change and flow regulation in alpine catchments

Understanding and predicting how biological communities respond to climate change is critical for assessing biodiversity vulnerability and guiding conservation efforts. Glacier‐ and snow‐fed rivers are one of the most sensitive ecosystems to climate change, and can provide early warning of wider‐scale changes. These rivers are frequently used for hydropower production but there is minimal understanding of how biological communities are influenced by climate change in a context of flow regulation. This study sheds light on this issue by disentangling structural (water temperature preference, taxonomic composition, alpha, beta and gamma diversities) and functional (functional traits, diversity, richness, evenness, dispersion and redundancy) effects of climate change in interaction with flow regulation in the Alps. For this, we compared environmental and aquatic invertebrate data collected in the 1970s and 2010s in regulated and unregulated alpine catchments. We hypothesized a replacement of cold‐adapted species by warming‐tolerant ones, high temporal and spatial turnover in taxa and trait composition, along with reduced taxonomic and functional diversities in consequence of climate change. We expected communities in regulated rivers to respond more drastically due to additive or synergistic effects between flow regulation and climate change. We found divergent structural but convergent functional responses between free‐flowing and regulated catchments. Although cold‐adapted taxa decreased in both of them, greater colonization and spread of thermophilic species was found in the free‐flowing one, resulting in higher spatial and temporal turnover. Since the 1970s, taxonomic diversity increased in the free flowing but decreased in the regulated catchment due to biotic homogenization. Colonization by taxa with new functional strategies (i.e. multivoltine taxa with small body size, resistance forms, aerial dispersion and reproduction by clutches) increased functional diversity but decreased functional redundancy through time. These functional changes could jeopardize the ability of aquatic communities facing intensification of ongoing climate change or new anthropogenic disturbances.     

Rewiring and indirect effects underpin modularity reshuffling in a marine food web under environmental shifts

Species are characterized by physiological and behavioral plasticity, which is part of their response to environmental shifts. Nonetheless, the collective response of ecological communities to environmental shifts cannot be predicted from the simple sum of individual species responses, since co‐existing species are deeply entangled in interaction networks, such as food webs. For these reasons, the relation between environmental forcing and the structure of food webs is an open problem in ecology. To this respect, one of the main problems in community ecology is defining the role each species plays in shaping community structure, such as by promoting the subdivision of food webs in modules—that is, aggregates composed of species that more frequently interact—which are reported as community stabilizers. In this study, we investigated the relationship between species roles and network modularity under environmental shifts in a highly resolved food web, that is, a “weighted” ecological network reproducing carbon flows among marine planktonic species. Measuring network properties and estimating weighted modularity, we show that species have distinct roles, which differentially affect modularity and mediate structural modifications, such as modules reconfiguration, induced by environmental shifts. Specifically, short‐term environmental changes impact the abundance of planktonic primary producers; this affects their consumers’ behavior and cascades into the overall rearrangement of trophic links. Food web re‐adjustments are both direct, through the rewiring of trophic‐interaction networks, and indirect, with the reconfiguration of trophic cascades. Through such “systemic behavior,” that is, the way the food web acts as a whole, defined by the interactions among its parts, the planktonic food web undergoes a substantial rewiring while keeping almost the same global flow to upper trophic levels, and energetic hierarchy is maintained despite environmental shifts. This behavior suggests the potentially high resilience of plankton networks, such as food webs, to dramatic environmental changes, such as those provoked by global change.     

Augmented Reticular Thalamic Bursting and Seizures in Scn1a-Dravet Syndrome

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Parasitism and alternative reproductive tactics in Northern chamois

Alternative reproductive tactics (ARTs), discrete phenotypic variations evolved to maximize fitness, may entail different cost‐benefit trade‐offs. In large mammals, differences in costs associated with ARTs—including energy expenditure and parasite infection—are typically greatest during the breeding season. Nonetheless, physiological and behavioral differences between ARTs can manifest throughout the year, possibly involving costs that may contribute to maintain ARTs within populations. Using the number of nematode larvae per gram of feces (LPG) as a proxy, we explored the temporal changes in lung parasite infection in territorial and nonterritorial male chamois Rupicapra in the Gran Paradiso National Park (Italy), between 2011 and 2012. We aimed to identify which tactic‐specific physiological and behavioral features (including age, hormonal levels, inter‐ and intrasexual interactions, and space use) or climatic factors (temperature and precipitation) best explained yearly variation in parasite infection within and between ARTs. Generalized additive mixed models showed that the fecal larval counts of lung nematodes underwent strong temporal changes in both male types. Differences between ARTs (with higher LPG values in territorial than nonterritorial males) were greatest during the rut and—to a lesser extent—in spring, respectively, at the peak and at the onset of territoriality. The difference in LPG between tactics was largely explained by the greater levels of hormone metabolites in territorial males during the rut. The other variables did not contribute significantly to explain the different shedding of larvae within and between ARTs. Our analysis suggests that different values of LPG between territorial and nonterritorial males are largely a result of tactic‐specific differences in the secretion of hormone metabolites, but only during the rut. To clarify whether rut‐related parasitism contributes to the maintenance of ARTs, tactic‐specific life history trade‐offs, for example, between reproduction and parasite‐related mortality, must be investigated.     

Multilocus phylogeography of the endemic and endangered angular angelshark (Squatina guggenheim) in the Southwest Atlantic Ocean

Hydrobiologia - The angular angelshark (Squatina guggenheim) is a coastal endangered angel shark from the Southwest Atlantic Ocean and one of the major bycatch victims. Despite major concerns about...     

Resiniferatoxin Hampers the Nocifensive Response of Caenorhabditis elegans to Noxious Heat,and Pathway Analysis Revealed that the Wnt Signaling Pathway is Involved

Resiniferatoxin (RTX) is a metabolite extracted from Euphorbia resinifera. RTX is a potent capsaicin analog with specific biological activities resulting from its agonist activity with the transient receptor potential channel vanilloid subfamily member 1 (TRPV1). RTX has been examined as a pain reliever, and more recently, investigated for its ability to desensitize cardiac sensory fibers expressing TRPV1 to improve chronic heart failure (CHF) outcomes using validated animal models. Caenorhabditis elegans (C. elegans) expresses orthologs of vanilloid receptors activated by capsaicin, producing antinociceptive effects. Thus, we used C. elegans to characterize the antinociceptive properties and performed proteomic profiling to uncover specific signaling networks. After exposure to RTX, wild-type (N2) and mutant C. elegans were placed on petri dishes divided into quadrants for heat stimulation. The thermal avoidance index was used to phenotype each tested C. elegans experimental group. The data revealed for the first time that RTX can hamper the nocifensive response of C. elegans to noxious heat (32 – 35 °C). The effect was reversed 6 h after RTX exposure. Additionally, we identified the RTX target, the C. elegans transient receptor potential channel OCR-3. The proteomics and pathway enrichment analysis results suggest that Wnt signaling is triggered by the agonistic effects of RTX on C. elegans vanilloid receptors.

     

Simultaneous monitoring of SARS-CoV-2 and bacterial profiles from the air of hospital environments with COVID-19-affected patients

Aerobiologia - The SARS-CoV-2 presence and the bacterial community profile in air samples collected at the Intensive Care Unit (ICU) of the Operational Unit of Infectious Diseases of Santa Caterina...     

The long periodicity phase (LPP) controversy part I: The influence of a natural-like ratio of the CER[EOS] analogue [EOS]-br in a CER[NP]/[AP] based stratum corneum modelling system: A neutron diffraction study

This study used neutron diffraction to investigate a ceramide-[NP] C24/[AP] C24 /[EOS]-br C30/cholesterol/lignoceric acid (0.6: 0.3: 0.1: 0.7: 1) based stratum corneum modelling system. By adding specifically deuterated ceramides-[NP]-D₃, [AP]-D₃, and [EOS]-br-D₃, detailed information on the lamellar and the nanostructure of the system was obtained. For the short periodicity phase a natural-like lamellar repeat distance of 5.47?±?0.02?nm was observed, similar to the [NP]/[AP] base system without the [EOS]-br. Unlike in this system the ceramides here were slightly tilted, hinting towards a slightly less natural arrangement. Due to the deuteration it was possible to observe that the long ceramide chains were overlapping in the lamellar mid-plane. This is considered to be an important feature for the natural stratum corneum. Despite the presence of a ceramide [EOS] analogue – able to form a long phase arrangement – no distinct long periodicity phase was formed, despite a slightly higher than natural ω-acyl ceramide ratio of 10?mol%. The deuterated variant of this ceramide determined that the very long ceramide was integrated into the short periodicity phase, spanning multiple layers instead. The – compared to the base system – unchanged repeat distance highlights the stability of this structure. Furthermore, the localisation of the very long ceramide in the short periodicity phase indicates the possibility of a crosslinking effect and thus a multilayer stabilizing role for the ceramide [EOS]. It can be concluded, that additionally to the mere presence of ceramide-[EOS] more complex conditions have to be met in order to form this long phase. This has to be further investigated in the future.     

Constitutively solvent-tolerant Pseudomonas taiwanensis VLB120∆ C∆ ttgV supports particularly high-styrene epoxidation activities when grown under glucose excess conditions

Solvent-tolerant bacteria represent an interesting option to deal with the substrate and product toxicity in bioprocesses. Recently, constitutive solvent tolerance was achieved for Pseudomonas taiwanensis VLB120 via knockout of the regulator TtgV, making tedious adaptation unnecessary. Remarkably, ttgV knockout increased styrene epoxidation activities of P. taiwanensis VLB120Δ C. With the aim to characterize and exploit the biocatalytic potential of P. taiwanensis VLB120Δ C and VLB120Δ CΔ ttgV, we investigated and correlated growth physiology, native styrene monooxygenase (StyAB) gene expression, whole-cell bioconversion kinetics, and epoxidation performance. Substrate inhibition kinetics was identified but was attenuated in two-liquid phase bioreactor setups. StyA fusion to the enhanced green fluorescent protein enabled precise enzyme level monitoring without affecting epoxidation activity. Glucose limitation compromised styAB expression and specific activities (30–40 U/g _CDW for both strains), whereas unlimited batch cultivation enabled specific activities up to 180 U/g _CDW for VLB120Δ CΔ ttgV strains, which is unrivaled for bioreactor-based whole-cell oxygenase biocatalysis. These extraordinarily high specific activities of constitutively solvent-tolerant P. taiwanensis VLB120∆ C∆ ttgV could be attributed to its high metabolic capacity, which also enabled high expression levels. This, together with the high product yields on glucose and biomass obtained qualifies the VLB120∆ ttgV strain as a highly attractive tool for the development of ecoefficient oxyfunctionalization processes and redox biocatalysis in general.