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Cerebral palsy (CP) describes some upper motoneuron disorders due to non‐progressive disturbances occurring in the developing brain that cause progressive changes to muscle. While longer sarcomeres increase muscle stiffness in patients with CP compared to typically developing (TD) patients, changes in extracellular matrix (ECM) architecture can increase stiffness. Our goal was to investigate how changes in muscle and ECM architecture impact muscle stiffness, gait and joint function in CP. Gracilis and adductor longus biopsies were collected from children with CP undergoing tendon lengthening surgery for hamstring and hip adduction contractures, respectively. Gracilis biopsies were collected from TD patients undergoing anterior cruciate ligament reconstruction surgery with hamstring autograft. Muscle mechanical testing, two‐photon imaging and hydroxyproline assay were performed on biopsies. Corresponding data were compared to radiographic hip displacement in CP adductors (CPA), gait kinematics in CP hamstrings (CPH), and joint range of motion in CPA and CPH. We found at matched sarcomere lengths muscle stiffness and collagen architecture were similar between TD and CP hamstrings. However, CPH stiffness (R2 = 0.1973), collagen content (R2 = 0.5099) and cross‐linking (R2 = 0.3233) were correlated to decreased knee range of motion. Additionally, we observed collagen fibres within the muscle ECM increase alignment during muscular stretching. These data demonstrate that while ECM architecture is similar between TD and CP hamstrings, collagen fibres biomechanics are sensitive to muscle strain and may be altered at longer in vivo sarcomere lengths in CP muscle. Future studies could evaluate the impact of ECM architecture on TD and CP muscle stiffness across in vivo operating ranges. Key points: At matched sarcomere lengths, gracilis muscle mechanics and collagen architecture are similar in TD patients and patients with CP.In both TD and CP muscles, collagen fibres dynamically increase their alignment during muscle stretching.Aspects of muscle mechanics and collagen architecture are predictive of in vivo knee joint motion and radiographic hip displacement in patients with CP.Longer sarcomere lengths in CP muscle in vivo may alter collagen architecture and biomechanics to drive deficits in joint mobility and gait function. [ABSTRACT FROM AUTHOR]

Tall fescue (Festuca arundinacea Schreb.) is a perennial C3 grass species usually associated with the endophyte fungus Epichloë coenophiala that enhances tolerance to biotic and abiotic stresses. Given that the proportion of infected tall fescue plants in the grasslands of the Flooding Pampa (Argentina) has been progressively increasing, it is proposed that endophytes confer tolerance to the stresses characteristic of that environment, especially flooding. Plants from a naturalized population and a commercial cultivar were grown, both with and without endophyte (wild type and AR584 respectively). The plants were subjected to two submergence treatments (i.e., control and partial submergence) in two development stages (5‐leaf stage and beginning of the elongation of internodes). Plant performance (aerial and root biomass, root aerenchyma formation, total root length and root diameter, proportion of reproductive tillers, number of panicles and seeds produced) and endophyte transmission to progeny were evaluated. Endophytes did not alter the ecological fitness of plants under partial submergence. Independently of the water condition, the symbiosis was linked to low biomass in plants from the naturalized population, while the opposite occurred in plants from the cultivar. Partial submergence did not affect the germination of the seeds produced, nor the transmission of the endophyte to the seedlings that originated from them. Our work suggests that the invasion ability of tall fescue in the Flooding Pampa grasslands is not related to an endophyte‐mediated improvement of plants to tolerate water excess. [ABSTRACT FROM AUTHOR]

The reduction in friction is a desired property in many industries. Some of the applications include the movement of liquid or slurry through a pipeline in oil or mining, the grinding of one metal on another during fabrication, metal on paper in the making of nearly any paper product, to even something closer to home with the movement of a brush or comb through one's hair. Friction yields higher degrees of strain or stress on one or both of the substrates. This can be costly due to energy requirements, wear of equipment, or even breakage of the substrate. Even though the need exists in so many industries, the mechanisms of lubricity vary enough in each that there really is not a universal lubricity aid that can successfully be applied across the different industries. A family of novel lubricity aids based on alkyl polyglucosides have been synthesized and evaluated in the lab on both metal/metal friction reduction as well as comb/hair friction reduction. One of the modified alkyl polyglucosides has yielded excellent reduction in friction in both applications. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study is to investigate the neurovascular bundle (NVB) as a potential orthodontic relapse factor. The mechanical properties and the forces generated in the NVB after orthodontic extrusion are explored. Materials and Methods: Six NVBs branching from the inferior alveolar nerve to the apices of the mandibular canines and premolars of mature pigs were harvested. Stress relaxation tests were conducted. A standard linear solid model (SLS) was utilized to simulate the orthodontic extrusion of a single rooted tooth with NVB length and cross‐sectional diameter of 3.6 and 0.5 mm, respectively, so the NVB was stretched 10% and 20% of its original length. The maximum force within the NVB was then calculated. Results: Based on our data, the average Young's modulus before relaxation (E0), after relaxation (EP) and the difference between Young's moduli before and after relaxation (ES) were 324 ± 123, 173 ± 73 and 151 ± 52 kPa, respectively. The theoretical force within the NVB stretched to 10% and 20% strain was 3 and 5 mN, respectively. Conclusion: The data from our study indicate that the NVB exhibits stress relaxation, a characteristic trait of viscoelastic materials. SLS model simulation predicted residual forces around 5 mN for elongation up to 20%. We observed strain hardening with additional elongation, which has the potential to cause forces to increase exponentially. Therefore, tensile forces in the NVB should not be ruled out as a contributor to orthodontic relapse, especially in adult patients who may have decreased adaptability of their NVB. Further preclinical and clinical models should be developed to further clarify what is the contribution of the NVB to orthodontic relapse. [ABSTRACT FROM AUTHOR]

Introduction: Zika virus (ZIKV) is a human teratogen that causes congenital Zika syndrome (CZS). AXL, TLR3, and STAT2 are proteins involved in the ZIKV's entry into cells (AXL) and host's immune response (TLR3 and STAT2). In this study, we evaluated the role of genetic polymorphisms in these three genes as risk factors to CZS, and highlighted which proteins that interact with them could be important for ZIKV infection and teratogenesis. Materials and methods: We evaluate eighty-eight children exposed to ZIKV during the pregnancy, 40 with CZS and 48 without congenital anomalies. The evaluated polymorphisms in AXL (rs1051008), TLR3 (rs3775291), and STAT2 (rs2066811) were genotyped using TaqMan® Genotyping Assays. A protein-protein interaction network was created in STRING database and analyzed in Cytoscape software. Results: We did not find any statistical significant association among the polymorphisms and the occurrence of CZS. Through the analyses of the network composed by AXL, TLR3, STAT2 and their interactions targets, we found that EGFR and SRC could be important proteins for the ZIKV infection and its teratogenesis. Conclusion: In summary, our results demonstrated that the evaluated polymorphisms do not seem to represent risk factors for CZS; however, EGFR and SRC appear to be important proteins that should be investigated in future studies. [ABSTRACT FROM AUTHOR]

Summary: Software defined network (SDN) is a paradigm that emphasizes the separation of the control plane from the data plane, offering advantages such as flexibility and programmability. However, from a security perspective, SDN also introduces new vulnerabilities due to the communication required between these planes. SYN Flood attacks are typical distributed denial‐of‐service (DDoS) attacks that especially challenge network administrators since they produce a large volume of semi‐open TCP connections to a target, compromising its availability. Most of the current solutions to detect and mitigate these attacks are designed to operate at the control plane, imposing an additional overhead on controller functions. Moreover, traffic‐blocking mechanisms, a widely used alternative to protect network resources, have the drawback of restricting legitimate traffic. This work proposes DataPlane‐ML, an integrated solution to detect and mitigate DDoS attacks on SDN, acting directly in the data plane. DataPlane‐ML uses machine learning techniques for attack detection and a mitigation solution based on the node's reputation to avoid blocking legitimate traffic during an attack. Experimental results show that DataPlane‐ML is ≈26%$$ \approx 26\% $$ faster than statistical‐based solutions for attack detection while presenting better accuracy. Moreover, the DataPlane‐ML mitigation solution can preserve more than 95%$$ 95\% $$ of legitimate traffic during an attack. [ABSTRACT FROM AUTHOR]

Observations from a granitic watershed within a Mediterranean climate reveal the hydrologic and critical zone functioning of a perennial stream headwater and its upslope contributing area within a meadow system in the Sierra Nevada, California. Chemical analysis (diagnostic tools of mixing models, end member mixing analysis, tritium, etc.) and physical data (stream stage, piezometers, soil water, snowpack, etc.) indicate there are two primary pathways of water input into a headwater stream sourced from a mountain meadow. One input is a shallower and younger subsurface pathway with water that resembles snowpack chemistry, and the other a deeper and older subsurface pathway with water that reflects the chemistry of the groundwater derived from the contributing hillslopes. Multi‐year observations reveal that regardless of snowpack amount, during the period of peak hillslope infiltration, shallow and deep pathways in the hillslope behave similarly to initiate headwater streams. However, during summer dry periods, similarities in active pathways within the meadow center are not maintained between high and low snowpack years. With less snow, perennial groundwater discharge within the meadow center is eliminated, becoming only a seasonal source at the meadow's outlet. At the meadow's edge, geophysically observed downslope thinning in saprolite thickness creates reduced lateral transmissivity and initiation points for headwater streams via enhanced groundwater discharge of upslope water. Combined, these findings suggest how loss of snowpack and critical zone structure can together mediate hydrologic function in a wet meadow system in a Mediterranean climate. Creating new understanding about the stability of hydraulic functioning in headwater wet‐meadow systems under a changing climate. Plain Language Summary: A new combination of data sets collected over several years in the Sierra Nevada Mountains of California reveal how smaller wet meadows sustain headwater streamflow, or not, during years of higher or lower snowpack or drought. The location of streamflow generation at these sites may be strongly tied to the shape and characteristics of the weathered bedrock in the shallow subsurface. Findings from this study show how underground flow pathways of water can function to promote year‐round headwater stream sources in mountain environments with wet‐winter, dry‐summer climates, when large snowpacks are present. However, long‐term the prevalence of seasonal surface flooding in these headwater wet meadows may decrease as climate warms and snowpacks continue to decline and become more variable from year to year. Key Points: During low snow years, perennial surface saturation is lost within the meadow, but streamflow is sustained year‐round at the meadow's baseExistence of these groundwater‐fed meadows is related to regular surface saturation caused by downslope thinning of saproliteTogether, this suggests that under continued snowpack decline, regular surface saturation may be lost in mountain meadow systems [ABSTRACT FROM AUTHOR]

The influence of genetic drift on population dynamics during Pleistocene glacial cycles is well understood, but the role of selection in shaping patterns of genomic variation during these events is less explored. We resequenced whole genomes to investigate how demography and natural selection interact to generate the genomic landscapes of Downy and Hairy Woodpecker, species codistributed in previously glaciated North America. First, we explored the spatial and temporal patterns of genomic diversity produced by neutral evolution. Next, we tested (i) whether levels of nucleotide diversity along the genome are correlated with intrinsic genomic properties, such as recombination rate and gene density, and (ii) whether different demographic trajectories impacted the efficacy of selection. Our results revealed cycles of bottleneck and expansion, and genetic structure associated with glacial refugia. Nucleotide diversity varied widely along the genome, but this variation was highly correlated between the species, suggesting the presence of conserved genomic features. In both taxa, nucleotide diversity was positively correlated with recombination rate and negatively correlated with gene density, suggesting that linked selection played a role in reducing diversity. Despite strong fluctuations in effective population size, the maintenance of relatively large populations during glaciations may have facilitated selection. Under these conditions, we found evidence that the individual demographic trajectory of populations modulated linked selection, with purifying selection being more efficient in removing deleterious alleles in large populations. These results highlight that while genome‐wide variation reflects the expected signature of demographic change during climatic perturbations, the interaction of multiple processes produces a predictable and highly heterogeneous genomic landscape. [ABSTRACT FROM AUTHOR]

In the last decades, there is an increasing trend for replacing petro‐based adhesives with sustainable and eco‐friendly alternatives, especially in the wood industry. In this work it was developed and characterized novolac‐type phenolic resins from the full use of the cashew nut shell liquid (CNSL), an agro‐industrial residue and a rich source of phenolic compounds, sustainable alternative to petroleum‐derived chemicals, to develop bio‐based polymers. CNSL and paraformaldehyde were reacted, using oxalic acid as a catalyst, under a solvent‐free methodology. A dark and viscous resin of high molar mass and thermally stable was obtained. The development of highly bio‐based adhesives was proposed by combining CNSL‐based novolac resin (CNSL‐nov) with commercial epoxy resin (DGEBA), as an alternative to conventional hardeners. The use of the epoxy‐novolac system proved to be efficient and promising in obtaining new highly cross‐linked polymers with excellent thermal performance and with potential for wood industry, improving the bio‐based content of high‐performance adhesive. [ABSTRACT FROM AUTHOR]

Blends of poly(lactic acid) (PLA) and amine‐terminated butadiene‐acrylonitrile (ATBN) elastomer were prepared by solution with ATBN contents of 8–20 wt%. Films were molded by liquid deposition modeling 3D printing. Fourier transform infrared (FTIR) spectroscopy showed that the terminal carboxylic groups of the PLA chains reacted with the terminal amino groups of ATBN. Water was the byproduct of this reaction, causing PLA hydrolysis and accelerating the reaction. Thermogravimetric analysis (TGA) showed that components interaction caused a loss of PLA thermal stability. Scanning electron microscopy (SEM) of the blends revealed a porous morphology and no phase separation. There was change in the elongation when compared with neat PLA. Although the addition of a telechelic elastomer could improve PLA toughness, any benefits arising from such addition seem to be neutralized by PLA chain scission due to hydrolysis and porosity, resulting from the condensation reaction. [ABSTRACT FROM AUTHOR]

Postmenopausal hot flushes are caused by lack of estradiol (E2) but their neuroendocrine basis is still poorly understood. Here, we investigated the interrelationship between norepinephrine and hypothalamic neurons, with emphasis on kisspeptin neurons in the arcuate nucleus (ARC), as a regulatory pathway in the vasomotor effects of E2. Ovariectomized (OVX) rats displayed increased tail skin temperature (TST), and this increase was prevented in OVX rats treated with E2 (OVX + E2). Expression of Fos in the hypothalamus and the number of ARC kisspeptin neurons coexpressing Fos were increased in OVX rats. Likewise, brainstem norepinephrine neurons of OVX rats displayed higher Fos immunoreactivity associated with the increase in TST. In the ARC, the density of dopamine‐ß‐hydroxylase (DBH)‐immunoreactive (ir) fibers was not altered by E2 but, importantly, DBH‐ir terminals were found in close apposition to kisspeptin cells, revealing norepinephrine inputs to ARC kisspeptin neurons. Intracerebroventricular injection of the α2‐adrenergic agonist clonidine (CLO) was used to reduce central norepinephrine release, confirmed by the decreased 3‐methoxy‐4‐hydroxyphenylglycol/norepinephrine ratio in the preoptic area and ARC. Accordingly, CLO treatment in OVX rats reduced ARC Kiss1 mRNA levels and TST to the values of OVX + E2 rats. Conversely, CLO stimulated Kiss1 expression in the anteroventral periventricular nucleus (AVPV) and increased luteinizing hormone secretion. These findings provide evidence that augmented heat dissipation in OVX rats involves the increase in central norepinephrine that modulates hypothalamic areas related to thermoregulation, including ARC kisspeptin neurons. This neuronal network is suppressed by E2 and its imbalance may be implicated in the vasomotor symptoms of postmenopausal hot flushes. [ABSTRACT FROM AUTHOR]

The COVID‐19 pandemic caused by SARS‐CoV‐2 infection has led to socio‐economic shutdowns and the loss of over 5 million lives worldwide. There is a need for the identification of therapeutic targets to treat COVID‐19. SARS‐CoV‐2 spike is a target of interest for the development of therapeutic targets. We developed a robust SARS‐CoV‐2 S spike expression and purification protocol from insect cells and studied four recombinant SARS‐CoV‐2 spike protein constructs based on the original SARS‐CoV‐2 sequence using a baculovirus expression system: a spike protein receptor‐binding domain that includes the SD1 domain (RBD) coupled to a fluorescent tag (S‐RBD‐eGFP), spike ectodomain coupled to a fluorescent tag (S‐Ecto‐eGFP), spike ectodomain with six proline mutations and a foldon domain (S‐Ecto‐HexaPro(+F)), and spike ectodomain with six proline mutations without the foldon domain (S‐Ecto‐HexaPro(‐F)). We tested the yield of purified protein expressed from the insect cell lines Spodoptera frugiperda (Sf9) and Trichoplusia ni (Tni) and compared it to previous research using mammalian cell lines to determine changes in protein yield. We demonstrated quick and inexpensive production of functional glycosylated spike protein of high purity capable of recognizing and binding to the angiotensin converting enzyme 2 (ACE2) receptor. To further confirm functionality, we demonstrate binding of eGFP fused construct of the spike ectodomain (S‐Ecto‐eGFP) to surface ACE2 receptors on lung epithelial cells by flow cytometry analysis and show that it can be decreased by means of receptor manipulation (blockade or downregulation). [ABSTRACT FROM AUTHOR]

This work reports on the first identification of sapphirine‐bearing ultrahigh‐temperature (UHT) metamorphic rocks within the Borborema Province, in NE Brazil. The investigated UHT diatexites outcrop in the Arapiraca Complex, a high‐grade Palaeoproterozoic block embedded within the Neoproterozoic metavolcano‐sedimentary sequence of the Sergipano fold‐and‐thrust belt. A sapphirine‐bearing diatexite sample preserves two distinct residual mineral associations as inclusions in cordierite poikiloblasts: a volumetrically dominant silica‐saturated, garnet–sillimanite–orthopyroxene–quartz domain, and a restricted silica‐undersaturated, sapphirine–magnetite–spinel–corundum domain. Phase equilibrium modelling for the whole‐rock bulk composition constrains the reactions preserved in the silica‐saturated domain, which, coupled with reintegrated ternary feldspar thermometry and Al‐in‐orthopyroxene thermobarometry, indicates peak UHT metamorphism occurring at ~970°C/8.5 kbar followed by a clockwise near isobaric cooling stage crossing the H2O‐undersaturated solidus at ~910°C/7.7 kbar. The T–MSiO2 and P–T phase equilibrium models reveal that the stabilization of magnetite‐spinel in the silica‐undersaturated domain can be a product of domanial SiO2‐depletion ascribed to inherited compositional banding and progressive melt‐loss episodes. The appearance of sapphirine as thin coronae around previously formed magnetite‐spinel cores requires an increase in the bulk silica content during retrograde metamorphism. This was driven by variable degrees of chemical interaction between the silica‐undersaturated domain and trapped silica‐rich leucosomes. U–Pb dating of zircon coupled with trace element behaviour records the timing of melt crystallization between ca. 2.03 and 1.96 Ga, after peak UHT metamorphism and supporting a protracted, ca. 70 My period of melt presence in the crust. The UHT metamorphism in the Arapiraca Complex is related to a contemporaneous UHT event recorded within the São Francisco Craton and more broadly coincides with high geothermal gradients at ca. 2.0 Ga linked to the formation of the Columbia supercontinent. The integration of new petrological and geochronological data indicates that the Arapiraca Complex is a continental ribbon pulled away from the São Francisco–Congo palaeocontinent possibly during the early Neoproterozoic intermittent rifting events and opening of the Sergipano oceanic basin between ca. 0.98–0.74 Ga. During the late Neoproterozoic at ca. 0.63–0.57 Ga, the Arapiraca Complex continental ribbon was thrusted back onto the northern margin of the São Francisco Craton as an inlier of the Sergipano fold‐and‐thrust belt. [ABSTRACT FROM AUTHOR]

Controlled release systems were developed using biodegradable polymers/copolymers via polycondensation of glycerol with acids (citric, adipic, and succinic) with potassium chloride (KCl) 0, 10, 20, and 40 wt% followed by crosslinking at 120°C. Polymers were characterized by thermogravimetry, X‐ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy and UV‐Vis spectroscopy. All are thermally stable up to 200°C, therefore suitable for release in countries where temperatures reach 50°C. Fractographic analysis showed rubbery (rough and ductile) and hard (smooth and brittle) polymers depending on the acid used. The release profiles showed that hydrophilic (polar) polymers are easily hydrolyzed, generating faster release reaching 52% in 120 h. Less polar polymers delay KCl release below 20% at the same time. Therefore, it was possible to adjust the release by controlling the fertilizer content and the type of polymer, designing a fast or slow release to meet the needs of a given crop. [ABSTRACT FROM AUTHOR]

Environmental pollution at the current state of fossil fuel consumption has led clean energy devices like proton exchange membrane fuel cells (PEMFCs) to emerge as alternative energy generation solutions. However, the performance, durability, and efficiency limitations of PEMFCs have hindered their widespread adoption. Improving their performance and durability can be achieved by fundamentally understanding and tuning their catalyst layer structures and compositions. Transmission electron microscopy and scanning transmission electron microscopy have proven to be among the best characterization tools available to analyze the microstructural features of the catalyst layers of PEMFC devices. The ability to directly observe changes in catalyst materials during operation with high spatial and temporal resolutions by the means of In‐situ techniques can accelerate material development in the PEMFC field. In this article, structure, properties, and performance of PEMFC materials are reviewed, and their known degradation mechanisms are introduced. Available In‐situ TEM techniques are presented to guide the selection of suitable methods and approaches for studying the PEMFC systems. Finally, the current literature is presented on PEMFC research that has used In‐situ electrochemical liquid cell TEM to study materials evolution and degradation, highlighting the specific challenges and opportunities for applying the technique in the PEMFCs' field. [ABSTRACT FROM AUTHOR]

The 2019-2020 Australian Black Summer wildfires demonstrated that single events can have widespread and catastrophic impacts on biodiversity, causing a sudden and marked reduction in population size for many species. In such circumstances, there is a need for conservation managers to respond rapidly to implement priority remedial management actions for the most-affected species to help prevent extinctions. To date, priority responses have been biased towards high-profile taxa with substantial information bases. Here, we demonstrate that sufficient data are available to model the extinction risk for many less well-known species, which could inform much broader and more effective ecological disaster responses. Using publicly available collection and GIS datasets, combined with life-history data, we modelled the extinction risk from the 2019-2020 catastrophic Australian wildfires for 553 Australian native bee species (33% of all described Australian bee taxa). We suggest that two species are now eligible for listing as Endangered and nine are eligible for listing as Vulnerable under IUCN criteria, on the basis of fire overlap, intensity, frequency, and life-history traits: this tally far exceeds the three Australian bee species listed as threatened prior to the wildfire. We demonstrate how to undertake a wide-scale assessment of wildfire impact on a poorly understood group to help to focus surveys and recovery efforts. We also provide the methods and the script required to make similar assessments for other taxa or in other regions. [ABSTRACT FROM AUTHOR]

Discuss the impact of new diagnostic and planning technologies on the resolution of a clinical case of an upper central incisor with lateral perforation, root canal calcification and apical periodontitis. A 44‐year‐old woman sought treatment because of a colour change in an anterior tooth. The tooth had already been endodontically accessed, and she reported that two different clinicians had failed to locate the root canal. A Cone Beam Computed Tomography scan showed excessive wear and root perforation in the middle third, as well as pulp canal obliteration in the apical third. The perforation was treated using a biomaterial, and the root canal was located using guided endodontics. This treatment protocol was used to access, prepare, medicate with calcium hydroxide for 21 days and fill the root canal. Treatment results were satisfactory at 6‐month follow‐up. [ABSTRACT FROM AUTHOR]

Summary: Design flaws and vulnerabilities inherent to network protocols, devices, and services make Distributed Denial of Service (DDoS) a persisting threat in the cyberspace, despite decades of research efforts in the area. The historical vertical integration of traditional IP networks limited the solution space, forcing researchers to tweak network protocols while maintaining global compatibility and proper service to legitimate flows. The advent of Software‐Defined Networking (SDN) and advances in Programmable Data Planes (PDP) changed the state of affairs and brought novel possibilities to deal with such attacks. In summary, the ability of bringing together network intelligence to a control plane, and offloading flow processing tasks to the forwarding plane, opened up interesting opportunities for network security researchers unlike ever. In this article, we dive into recent research that relies on SDN and PDP to detect, mitigate, and prevent DDoS attacks. Our literature review takes into account the SDN layered view as defined in RFC7426 and focuses on the data, control, and application planes. We follow a systematic methodology to capture related articles and organize them into a taxonomy of DDoS defense mechanisms focusing on three facets: activity level, deployment location, and cooperation degree. From the analysis of existing work, we also highlight key research gaps that may foster future research in the field. [ABSTRACT FROM AUTHOR]

Background: Preeclampsia (PE) is a complex pregnancy syndrome characterised by maternal hypertension and organ damage after 20 weeks of gestation and is associated with an increased risk of cardiovascular disease later in life. Extracellular haemoglobin (Hb) and its metabolites heme and iron are highly toxic molecules and several defence mechanisms have evolved to protect the tissue. Objectives: We will discuss the roles of free iron, heme, Hb, and the scavenger proteins haemopexin and alpha‐1‐microglobulin in pregnancies complicated by PE and fetal growth restriction (FGR). Conclusion: In PE, oxidative stress causes syncytiotrophoblast (STB) stress and increased shedding of placental STB‐derived extracellular vesicles (STBEV). The level in maternal circulation correlates with the severity of hypertension and supports the involvement of STBEVs in causing maternal symptoms in PE. In PE and FGR, iron homeostasis is changed, and iron levels significantly correlate with the severity of the disease. The normal increase in plasma volume taking place during pregnancy is less for PE and FGR and therefore have a different impact on, for example, iron concentration, compared to normal pregnancy. Excess iron promotes ferroptosis is suggested to play a role in trophoblast stress and lipotoxicity. Non‐erythroid α‐globin regulates vasodilation through the endothelial nitric oxide synthase pathway, and hypoxia‐induced α‐globin expression in STBs in PE placentas is suggested to contribute to hypertension in PE. Underlying placental pathology in PE with and without FGR might be amplified by iron and heme overload causing oxidative stress and ferroptosis. As the placenta becomes stressed, the release of STBEVs increases and affects the maternal vasculature. [ABSTRACT FROM AUTHOR]

Aim: Our goal was to use eDNA metabarcoding to characterize fish community diversity, detect aquatic invasive species (AIS) and assess how measures of community (or AIS) diversity are influenced by lake physical and environmental covariates, measures of hydrological connectivity and human accessibility. Location: Michigan, USA. Methods: eDNA samples collected from 22 lakes were sequenced using two mitochondrial gene regions (12S and 16S rRNA). Metabarcoding data were compared to traditional fisheries survey data for a subset of lakes, and data from all 22 lakes were combined with environmental information to identify significant associations with community diversity and AIS relative abundance. Results: Occupancy modelling indicated that detection probabilities were generally higher with eDNA than traditional fisheries gear. Measures of connectivity with upstream aquatic habitats were positively associated with both AIS relative abundance and fish species diversity. We also demonstrate the use of spatial interpolation methods to map distributions of species diversity and AIS relative abundance within lakes. Main conclusions: eDNA metabarcoding methods provided information on the composition and diversity of fish assemblages and the presence of AIS in freshwater lakes that varied greatly in drainage connectivity and anthropogenic development. Our case study identified associations between environmental covariates and fish diversity or AIS relative abundance across lakes. This information is of particular importance given increasing anthropogenic disturbance, invasive species spread and associated declines in aquatic biodiversity. Incorporating eDNA metabarcoding as a supplement to traditional fisheries surveys will permit managers to identify greater numbers of taxa, including early detection of AIS, with less field effort and fish mortality. Further, eDNA methods may more accurately identify physical and biological features that correlate with diversity and abundance and allow agencies to more effectively direct AIS management activities. [ABSTRACT FROM AUTHOR]

In this study, the authors report morphological deformities in driftwood catfish Trachelyopterus galeatus (Auchenipteridae), an invasive catfish occurring in the Upper Paraná River basin, Brazil. The frequency of anomalous individuals reached 18.3% of all catches. X‐ray images showed anomalies, or total absence of structures, in the pelvic girdle. The authors also observed the absence of the adipose fin and mental barbels. These findings are of extreme importance for evidencing the anthropogenic impact on aquatic communities as the region suffers within fragmentation by dams and pollution from several human activities. This sort of information can be used in management systems and environmental monitoring, especially to protect other species and the native fish assemblage. [ABSTRACT FROM AUTHOR]

The COVID‐19 pandemic caused by SARS‐CoV‐2 has applied significant pressure on overtaxed healthcare around the world, underscoring the urgent need for rapid diagnosis and treatment. We have developed a bacterial strategy for the expression and purification of a SARS‐CoV‐2 spike protein receptor binding domain (RBD) that includes the SD1 domain. Bacterial cytoplasm is a reductive environment, which is problematic when the recombinant protein of interest requires complicated folding and/or processing. The use of the CyDisCo system (cytoplasmic disulfide bond formation in E. coli) bypasses this issue by pre‐expressing a sulfhydryl oxidase and a disulfide isomerase, allowing the recombinant protein to be correctly folded with disulfide bonds for protein integrity and functionality. We show that it is possible to quickly and inexpensively produce an active RBD in bacteria that is capable of recognizing and binding to the ACE2 (angiotensin‐converting enzyme) receptor as well as antibodies in COVID‐19 patient sera. [ABSTRACT FROM AUTHOR]

BACKGROUND The objective of this work was the development of silver nanoparticles (AgNPs) coated with humic acid (HA) and their incorporation into an enamel for antifungal activity. AgNPs were synthesized by chemical reduction using sodium borohydride as a reducing agent and coated with HA. Uncoated AgNPs were synthesized as control. AgNPs and HA‐AgNPs were characterized by ultraviolet–visible spectrophotometry, differential scanning calorimetry, dynamic light scattering, Fourier‐transform infrared spectroscopy (FTIR), atomic force microscopy and X‐ray diffraction (XRD). Size of AgNPs and HA‐AgNPs was recorded within the nano range, showing HA‐AgNPs' higher stability than non‐coated particles by presenting a single plasmatic band around 400 nm. RESULTS: Thermal analysis showed conjugated endothermic peaks, which confirms the compatibility of HA‐AgNPs. FTIR depicted absorptions between 1300 and 1000 cm−1 (CC, ArH, respectively), demonstrating that HA is adsorbed onto AgNPs. Thermogravimetric analysis showed that HA does not alter the reduction in mass loss of AgNPs, while it was found by XRD that adding HA promoted the formation of more amorphous AgNPs. The effectiveness of HA‐AgNPs was evaluated against three different fungal species. Minimum inhibitory concentration assays showed that ~0.5 mmol L−1 AgNPs was able to inhibit dermatophyte species growth. HA‐AgNPs were incorporated into a commercial enamel at a concentration of 8% and their organoleptic characteristics, drying time, centrifugation test and thermal stress were evaluated. Enamels with AgNPs kept their physicochemical properties over 21 days of storage. CONCLUSION: HA‐AgNP nail polish is thus proposed as an innovative material for onychomycosis infections. © 2021 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Non‐iridescent, structural coloration in birds originates from the feather's internal nanostructure (the spongy matrix) but melanin pigments and the barb's cortex can affect the resulting color. Here, we explore how this nanostructure is combined with other elements in differently colored plumage patches within a bird. We investigated the association between light reflectance and the morphology of feathers from the back and belly plumage patches of male swallow tanagers (Tersina viridis), which look greenish‐blue and white, respectively. Both plumage patches have a reflectance peak around 550 nm but the reflectance spectrum is much less saturated in the belly. The barbs of both types of feathers have similar spongy matrices at their tips, rendering their reflectance spectra alike. However, the color of the belly feather barbs changes from light green at their tips to white closer to the rachis. These barbs lack pigments and their morphology changes considerably throughout. Toward the rachis, the barb is almost hollow, with a reduced area occupied by spongy matrix, and has a flattened shape. By contrast, the blue back feathers' barbs have melanin underneath the spongy matrix resulting in a much more saturated coloration. The color of these barbs is also even along the barbs' length. Our results suggest that the color differences between the white and greenish‐blue plumage are mostly due to the differential deposition of melanin and a reduction of the spongy matrix near the rachis of the belly feather barbs and not a result of changes in the characteristics of the spongy matrix. Research Highlights: How does a bird produce feathers of strikingly different colors?Greenish‐blue photonic structures are present in both white and blue feathers of male swallow tanagers.Color differences result mainly from the differential deposition of melanin. [ABSTRACT FROM AUTHOR]

Three [1,3‐diethyl‐4‐(p‐methoxyphenyl)‐5‐(3,4,5‐trimethoxyphenyl)imidazol‐2‐ylidene](L)gold(I) complexes, 4 a (L=Cl), 5 a (L=PPh3), and 6 a (L=same N‐heterocyclic carbene (NHC)), and their fluorescent [4‐(anthracen‐9‐yl)‐1,3‐diethyl‐5‐phenylimidazol‐2‐ylidene](L)gold(I) analogues, 4 b, 5 b, and 6 b, respectively, were studied for their localisation and effects in cancer cells. Despite their identical NHC ligands, the last three accumulated in different compartments of melanoma cells, namely, the nucleus (4 b), mitochondria (5 b), or lysosomes (6 b). Ligand L was also more decisive for the site of accumulation than the NHC ligand because the couples 4 a/4 b, 5 a/5 b, and 6 a/6 b, carrying different NHC ligands, afforded similar results in cytotoxicity tests, and tests on targets typically found at their sites of accumulation, such as DNA in nuclei, reactive oxygen species and thioredoxin reductase in mitochondria, and lysosomal membranes. Regardless of the site of accumulation, cancer cell apoptosis was eventually induced. The concept of guiding a bioactive complex fragment to a particular subcellular target by secondary ligand L could reduce unwanted side effects. [ABSTRACT FROM AUTHOR]

Ourdockingstudiesbetweenhomotrimeric (RBD containing chain A) S protein and stem bromelain revealed that bromelain cleaves the S-protein equally likelyatthe131-166(50.4%)and617-649(49.6%)disulfide bonds (Fig. Theseresultsdemonstrate that bromelain's cysteine protease activity is responsible for the cleavage of host cells' ACE-2 and SARS-CoV-2 S-protein. 10 Since bromelain inhibits SARS-CoV-2 infection, and its profound fibrinolytic activity 6 suggests that bromelain or bromelain-rich pineapple could be used as an antiviral against SARS-CoV-2 and future outbreaks of other coronaviruses. [Extracted from the article]

Key points: The amount of fibrotic material in dystrophic mouse muscles relates to contractile function, but not passive function.Collagen fibres in skeletal muscle are associated with increased passive muscle stiffness in fibrotic muscles.The alignment of collagen is independently associated with passive stiffness in dystrophic skeletal muscles.These outcomes demonstrate that collagen architecture rather than collagen content should be a target of anti‐fibrotic therapies to treat muscle stiffness. Fibrosis is prominent in many skeletal muscle pathologies including dystrophies, neurological disorders, cachexia, chronic kidney disease, sarcopenia and metabolic disorders. Fibrosis in muscle is associated with decreased contractile forces and increased passive stiffness that limits joint mobility leading to contractures. However, the assumption that more fibrotic material is directly related to decreased function has not held true. Here we utilize novel measurement of extracellular matrix (ECM) and collagen architecture to relate ECM form to muscle function. We used mdx mice, a model for Duchenne muscular dystrophy that becomes fibrotic, and wildtype mice. In this model, extensor digitorum longus (EDL) muscle was significantly stiffer, but with similar total collagen, while the soleus muscle did not change stiffness, but increased collagen. The stiffness of the EDL was associated with increased collagen crosslinking as determined by collagen solubility. Measurement of ECM alignment using polarized light microscopy showed a robust relationship between stiffness and alignment for wildtype muscle that broke down in mdx muscles. Direct visualization of large collagen fibres with second harmonic generation imaging revealed their relative abundance in stiff muscles. Collagen fibre alignment was linked to stiffness across all muscles investigated and the most significant factor in a multiple linear regression‐based model of muscle stiffness from ECM parameters. This work establishes novel characteristics of skeletal muscle ECM architecture and provides evidence for a mechanical function of collagen fibres in muscle. This finding suggests that anti‐fibrotic strategies to enhance muscle function and excessive stiffness should target large collagen fibres and their alignment rather than total collagen. Key points: The amount of fibrotic material in dystrophic mouse muscles relates to contractile function, but not passive function.Collagen fibres in skeletal muscle are associated with increased passive muscle stiffness in fibrotic muscles.The alignment of collagen is independently associated with passive stiffness in dystrophic skeletal muscles.These outcomes demonstrate that collagen architecture rather than collagen content should be a target of anti‐fibrotic therapies to treat muscle stiffness. [ABSTRACT FROM AUTHOR]

The article offers information on peripheral blood morphologic findings in patients with COVID-19. Topics include findings of left-shifted myeloid lineage cells and enlarged platelets both point to early release of immature forms from the bone marrow, reflecting a stress response that may be seen in several infectious and inflammatory conditions, and the morphologic features that differed most significantly between the groups of patients were circulating plasma cells and smudged neutrophils.

The rapid spread of Internet of Things (IoT) devices in recent years has driven the creation of a number of IoT middleware for enabling communication between devices using different standards and technologies. Such middleware facilitates the development of IoT solutions, allowing the developer to handle data and devices through middleware without the need to understand and communicate with each device individually. Although some studies present the performance of middleware solutions, they do not consider the effect of the underlying programming language in the overall performance of the solution. This paper replicates a common middleware use case in three different programming languages, evaluates their comparative performance, and discusses the results found. In the studied use case, Javascript presents better performance for small to medium applications, while, globally, Java demonstrates to be the most robust choice for IoT middleware. [ABSTRACT FROM AUTHOR]

We examined the relationships between the Dark Triad personality traits (Machiavellianism, narcissism, and psychopathy), attitudes towards doping, and cheating behaviour among athletes. One-hundred and sixty-four athletes completed a completed a matrix solving task within a specific time limit. Participants were told they would receive a financial reward for the total number matrices they could solve, but only 13 of the 20 matrices were solvable. This provided the incentive and opportunity for the athletes to cheat. Following this, athletes completed two questionnaires, which assessed the Dark Triad and their attitudes towards doping. All three Dark Triad personality traits correlated positively with attitudes towards doping and cheating behaviour. Regression analyses revealed that psychopathy and narcissism positively predicted attitudes towards doping, and narcissism emerged as a positive predictor of cheating behaviour. Attitudes towards doping correlated positively with cheating behaviour. The Dark Triad appears to be important in relation to both attitudes towards doping and cheating behaviour among athletes. In addition, our findings illustrate that favourable attitudes towards doping are linked with actual cheating among athletes. National Anti-Doping Organizations, sports federations, and coaches could assess athletes' Dark Triad scores and attitudes towards doping in order to identify who may be more likely to cheat. [ABSTRACT FROM AUTHOR]

Spatial patterns of intraspecific variation are shaped by geographical distance among populations, historical changes in gene flow and interactions with local environments. Although these factors are not mutually exclusive and operate on both genomic and phenotypic variation, it is unclear how they affect these two axes of variation. We address this question by exploring the predictors of genomic and phenotypic divergence in Icterus gularis, a broadly distributed Middle American bird that exhibits marked geographical variation in body size across its range. We combined a comprehensive single nucleotide polymorphism and phenotypic data set to test whether genome‐wide genetic and phenotypic differentiation are best explained by (i) isolation by distance, (ii) isolation by history or (iii) isolation by environment. We find that the pronounced genetic and phenotypic variation in I. gularis are only partially correlated and differ regarding spatial predictors. Whereas genomic variation is largely explained by historical barriers to gene flow, phenotypic diversity can be best predicted by contemporary environmental heterogeneity. Our genomic analyses reveal strong phylogeographical structure coinciding with the Chivela Pass at the Isthmus of Tehuantepec that was formed during the Pleistocene, when populations were isolated in north–south refugia. In contrast, we found a strong association between body size and environmental variables, such as temperature and precipitation. The relationship between body size and local climate is consistent with a pattern produced by either natural selection or environmental plasticity. Overall, these results provide empirical evidence for why phenotypic and genomic data are often in conflict in taxonomic and phylogeographical studies. [ABSTRACT FROM AUTHOR]

Climate change presents risks both in terms of warming and increased variability that are heightened when compounded. It is thus notable that the simulations in the Coupled Model Intercomparison Project Phase 5 (CMIP5) showing greater Northern midlatitude continental warming also show a greater increase in monthly average temperature variance, particularly in Europe. European variability increases with warming at a rate of 0.40°C2/°C (95% C.I. [0.28, 0.50]), with local warming rates explaining 71% of the intermodel difference in variability changes. Coupling between warming and variance increases the probability of high temperatures compared to a scenario where variance is stable. If warming were to reach 6°C, the risk of monthly average temperature exceeding a 30°C threshold is 4 times greater in the increased‐variance scenario. Despite the simple scaling across models suggesting some common origin, changes in model temperature and variance potentially involve a range of mechanisms whose contributions remain unclear. Plain Language Summary: Extreme and persistent summertime temperatures present risks to human health, property, and natural systems. The frequency of hot extremes increases in response to both growing mean temperature and increasing variability. Here we show that models that predict higher summertime warming also predict greater increases in temperature variability in midlatitude continents, especially in Europe. The combination of warming and increased variability makes the chances of hot extremes much greater than if temperature variance stayed constant. The reasons for increased variability may involve changes in soil moisture, variability in local radiation, and changes in atmospheric circulation, but exactly why a simple scaling between warming and increased variance emerges in Europe and elsewhere is unclear. Key Points: Summertime temperature variability and warming in NH midlatitudes covary across CMIP5 models, especially in EuropeSuch covariance between warming and increased variability accentuates risks of future high‐temperature eventsAlbeit a weaker relationship than with warming, increases in variability also scale with biases in simulated historical variability [ABSTRACT FROM AUTHOR]

Biolubricants are becoming interesting alternatives to mineral lubricants. Despite their advantages, development of lubricants from vegetable oils may compete with food production, turning their use impractical due to socio‐economic aspects. Here, cardanol is used as raw material in the synthesis of novel biolubricants under environmentally friendly conditions. These compounds are characterized by NMR and Fourier transform infrared spectroscopy. Thermal‐oxidative studies show the elevated stability and higher onset oxidative temperatures. Tribological analyses performed under high‐frequency linear‐oscillation motion indicate lower coefficients of friction and wear rates compared to a synthetic oil. Therefore, cardanol, under simple, fast, and sustainable processes can be transformed into valuable alternatives for petroleum‐based lubricants. Practical Applications: The novel cardanol‐based biolubricants presented in this work show interesting chemical and lubricity properties superior to standard synthetic oils, which make them potential substitutes for the current oil‐based products used as lubricants. Additionally, the ecofriendly methodologies employed reduce significantly the reaction time as well as eliminating the need for catalysts or solvents, making these processes viable alternatives for the traditional methods reported in literature for the synthesis of this class of compounds. [ABSTRACT FROM AUTHOR]

Oral lichen planus (OLP) is a common chronic inflammatory disease of unknown etiology that mainly affects middle-aged women, with no racial predilection.[1] Based on the modified World Health Organization (WHO) diagnostic criteria for OLP proposed by van der Meij and van der Waal,[2] definitive diagnosis depends on the clinicopathological correlation, and requires the presence of bilateral, more or less symmetrical reticular lesions, a well-defined band-like zone of lymphocytes, and signs of liquefaction degeneration of the basal cell epithelial layer. Histopathological examination of all OLP patients (29/29; 100%) and nine OLL patients (32.1%) showed liquefactive degeneration of basal cell layer and a band-like lymphocytic infiltrate in the subepithelial connective tissue (Figure). Hyperparakeratinization was observed in 21 OLP patients (72.4%) and 17 OLL patients (60.7%), and apoptotic bodies were found in five OLP (17.2%) and five OLL patients (17.8%), particularly in the basal epithelial cell layer. [Extracted from the article]

Background: M2 macrophages are often detected in oral squamous cell carcinoma (OSCC), which, influenced by hypoxic conditions, appear to have high angiogenesis‐inducing capacity. However, the effects of immunosenescence on tumor‐associated macrophages (TAMs) and angiogenesis in OSCC are unknown. Methods: Fifty‐seven OSCCs were divided into 3 groups (I: <40 years [n = 17]; II: 40‐65 years [n = 20]; III: >65 years [n = 20]). Immunohistochemistry for CD68 and CD163 (TAMs), and CD34 and D2‐40 for microvessel density (MVD), microvessel area (MVA), and total vascular area (TVA) were performed. Results: All groups showed similar clinicopathological and immunohistochemical findings. Similar CD68 and CD163 expression, confirmed a M2 phenotype. MVD, MVA, and TVA were similar, however, with significant predominance of blood vessels. No significant correlation between macrophage and angiogenic markers was observed. Conclusions: A similar TAM and angiogenesis profile suggests the participation of other mechanisms, instead immunosenescence, in young and elderly OSCC patients. [ABSTRACT FROM AUTHOR]

Introduction: Dysferlin loss-of-function mutations cause muscular dystrophy, accompanied by impaired membrane repair and muscle weakness. Growth promoting strategies including insulin-like growth factor 1 (IGF-1) could provide benefit but may cause strength loss or be ineffective. The objective of this study was to determine whether locally increased IGF-1 promotes functional muscle hypertrophy in dysferlin-null (Dysf-/- ) mice.Methods: Muscle-specific transgenic expression and postnatal viral delivery of Igf1 were used in Dysf-/- and control mice. Increased IGF-1 levels were confirmed by enzyme-linked immunosorbent assay. Testing for skeletal muscle mass and function was performed in male and female mice.Results: Muscle hypertrophy occurred in response to increased IGF-1 in mice with and without dysferlin. Male mice showed a more robust response compared with females. Increased IGF-1 did not cause loss of force per cross-sectional area in Dysf-/- muscles.Discussion: We conclude that increased local IGF-1 promotes functional hypertrophy when dysferlin is absent and reestablishes IGF-1 as a potential therapeutic for dysferlinopathies. [ABSTRACT FROM AUTHOR]

The capability to perform high‐pressure low‐temperature nuclear inelastic scattering on 125Te and 121Sb with a sapphire backscattering monochromator is presented. This technique was applied to measure nuclear inelastic scattering in TeO2 at pressures up to 10 GPa and temperatures down to 25 K. The evaluated partial Te densities of phonon states were compared with theoretical calculations and with Raman scattering measured under the same conditions. The high‐pressure cell developed in this work can also be used for other techniques at pressures up to at least 100 GPa. [ABSTRACT FROM AUTHOR]

A new mutillid wasp, Ephutomorpha tyla Hearn, Williams & Parslow sp. nov., is described from adult female and male specimens from the Dandenong Ranges in Victoria, Australia. Adult mutillids were repeatedly found in nests of the hylaeine bee Amphylaeus morosus (Smith, 1879) (Hylaeinae) and reared from host nest cells. This represents the first recorded host–parasite association between Mutillidae and hylaeine bee species. [ABSTRACT FROM AUTHOR]

Background: The ABILOCO is a self-reported questionnaire, specific for individuals with stroke, for the assessment of ability of locomotion. The ABILOCO has been investigated using the Rasch model and has shown satisfactory measurement properties. However, its test-retest reliability has not been investigated.Objective: To investigate the test-retest reliability, that is, agreement, systematic and random variability of the ABILOCO Questionnaire in individuals with chronic stroke.Design: A test-retest reliability study.Setting: Research laboratory.Participants: Thirty-one individuals (21 men and 10 women; mean age, 60 years), who had poststroke hemiparesis.Intervention: Not applicable.Main Outcome Measurement: The ABILOCO was applied twice, on two occasions, 5 to 7 days apart. Test-retest reliability was investigated, as follows: agreement by the calculation of intraclass correlation coefficients (ICCs); systematic variability by the change in the mean; random variability by the standard error of measurement (SEM) and smallest real difference (SRD).Results: Two outliers were identified in the sample. The ICC values for the whole sample were 0.76 (CI 95% 0.56 to 0.88), whereas the SEM (SEM%) and SRD (SRD%) were 0.55 (21%) and 1.52 (58%), respectively.Conclusion: The ABILOCO showed to be reliable to be applied within clinical and research contexts for the assessment of changes in locomotion ability of a group of individuals with chronic stroke. However, it appears to be less suitable to detect changes at individual levels.Level Of Evidence: III. [ABSTRACT FROM AUTHOR]

The Andes harbours a rich diversity of Muscidae. A new muscid genus, Polletella de Carvalho & Haseyama, gen. nov., is described from the Ecuadorian and Peruvian highlands, and it comprises three new species: Polletella polleti de Carvalho, Haseyama & Gomes, sp. nov. (type species) and Polletella norrbomi de Carvalho, Haseyama & Gomes, sp. nov., both from Loja, Cajanuma, Ecuador, and Polletellainca de Carvalho, Haseyama & Gomes, sp. nov. from Cuzco, Peru. Collected data indicate that species of Polletella are probably confined to high‐altitude cloud Andean forests and may be abundant at 3000 m. A key to the species of Polletella is provided. The morphological features and a morphology‐based phylogenetic analysis indicate that Polletella is monophyletic and that it does not concur with the current concepts of any of the Neotropical Phaoniinae genera. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the use of an affine‐variance noise model, with correlated quantum noise and spatially dependent quantum gain, for the simulation of noise in virtual clinical trials (VCT) of digital breast tomosynthesis (DBT). Methods: Two distinct technologies were considered: an amorphous‐selenium (a‐Se) detector with direct conversion and a thallium‐doped cesium iodide (CsI(Tl)) detector with indirect conversion. A VCT framework was used to generate noise‐free projections of a uniform three‐dimensional simulated phantom, whose geometry and absorption match those of a polymethyl methacrylate (PMMA) uniform physical phantom. The noise model was then used to generate noisy observations from the simulated noise‐free data, while two clinically available DBT units were used to acquire projections of the PMMA physical phantom. Real and simulated projections were then compared using the signal‐to‐noise ratio (SNR) and normalized noise power spectrum (NNPS). Results: Simulated images reported errors smaller than 4.4% and 7.0% in terms of SNR and NNPS, respectively. These errors are within the expected variation between two clinical units of the same model. The errors increase to 65.8% if uncorrelated models are adopted for the simulation of systems featuring indirect detection. The assumption of spatially independent quantum gain generates errors of 11.2%. Conclusions: The investigated noise model can be used to accurately reproduce the noise found in clinical DBT. The assumption of uncorrelated noise may be adopted if the system features a direct detector with minimal pixel crosstalk. [ABSTRACT FROM AUTHOR]