This work intends to investigate the impact of silicon layer thickness and substrate biasing on the UV photodetection efficiency of PIN diodes fabricated with ultra‐thin body and buried oxide (UTBB ...silicon‐on‐insulator SOI) technology, aiming to verify their behaviour on an ultimate commercial technology. UV photodetectors are applied in different fields, such as environmental and biomedical ones, and their implementation in UTBB SOI could enable the design of mixed circuits where data acquisition and processing could be made in the same chip, enhancing systems’ performance. It is shown that a 20‐nm‐thick silicon layer can be applied for UV photodetection and enhanced generated current is obtained when substrate bias is set to guarantee a depletion regime in the entire active layer.
PIN diode devices implemented in the ultra‐thin body and buried oxide (UTBB silicon‐on‐insulator SOI) technology for photodetection applications.
Very thin silicon layers can be applied for UV photodetection (wavelengths of around 350 nm) with the aid of active substrate biasing (Vsub).
Maximum photogenerated current is reached for different Vsub ranges when P‐ and N‐type ground planes are implemented in a device with a silicon thickness of 20 nm.
A complex brain is central to the success of backboned animals. However, direct evidence bearing on vertebrate brain evolution comes almost exclusively from extant species, leaving substantial ...knowledge gaps. Although rare, soft-tissue preservation in fossils can yield unique insights on patterns of neuroanatomical evolution. Paleontological evidence from an exceptionally preserved Pennsylvanian (∼318 Ma) actinopterygian, Coccocephalus, calls into question prior interpretations of ancestral actinopterygian brain conditions. However, the ordering and timing of major evolutionary innovations, such as an everted telencephalon, modified meningeal tissues, and hypothalamic inferior lobes, remain unclear. Here, we report two distinct actinopterygian morphotypes from the latest Carboniferous-earliest Permian (∼299 Ma) of Brazil that show extensive soft-tissue preservation of brains, cranial nerves, eyes, and potential cardiovascular tissues. These fossils corroborate inferences drawn from ✝Coccocephalus, while adding new information about neuroanatomical evolution. Skeletal features indicate that one of these Brazilian morphotypes is more closely related to living actinopterygians than the other, which is also reflected in soft-tissue features. Significantly, the more crownward morphotype shows a key neuroanatomical feature of extant actinopterygians—an everted telencephalon—that is absent in the other morphotype and ✝Coccocephalus. All preserved Paleozoic actinopterygian brains show broad similarities, including an invaginated cerebellum, hypothalamus inferior lobes, and a small forebrain. In each case, preserved brains are substantially smaller than the enclosing cranial chamber. The neuroanatomical similarities shared by this grade of Permo-Carboniferous actinopterygians reflect probable primitive conditions for actinopterygians, providing a revised model for interpreting brain evolution in a major branch of the vertebrate tree of life.
•Soft-tissue preservation is found in late Paleozoic ray-finned fishes from Brazil•Brain anatomy differs among fossil taxa•One of these fossils represents the oldest evidence of an everted telencephalon•The fossil taxa bear a mosaic of “primitive” and “derived” characters
Figueroa et al. show that soft-tissue preservation in fossil ray-finned fishes is informative for interpreting evolution of neuroanatomy. Using X-ray micro-tomography, they find key differences in brain morphology among extinct taxa. These fossils indicate a more complex evolutionary history for ray-finned fish brains than previously anticipated.
The origin of the air sac system present in birds has been an enigma for decades. Skeletal pneumaticity related to an air sac system is present in both derived non-avian dinosaurs and pterosaurs. But ...the question remained open whether this was a shared trait present in the common avemetatarsalian ancestor. We analyzed three taxa from the Late Triassic of South Brazil, which are some of the oldest representatives of this clade (233.23 ± 0.73 Ma), including two sauropodomorphs and one herrerasaurid. All three taxa present shallow lateral fossae in the centra of their presacral vertebrae. Foramina are present in many of the fossae but at diminutive sizes consistent with neurovascular rather than pneumatic origin. Micro-tomography reveals a chaotic architecture of dense apneumatic bone tissue in all three taxa. The early sauropodomorphs showed more complex vascularity, which possibly served as the framework for the future camerate and camellate pneumatic structures of more derived saurischians. Finally, the evidence of the absence of postcranial skeletal pneumaticity in the oldest dinosaurs contradicts the homology hypothesis for an invasive diverticula system and suggests that this trait evolved independently at least 3 times in pterosaurs, theropods, and sauropodomorphs.
Telomere length measurement is an essential test for the diagnosis of telomeropathies, which are caused by excessive telomere erosion. Commonly used methods are terminal restriction fragment (TRF) ...analysis by Southern blot, fluorescence in situ hybridization coupled with flow cytometry (flow-FISH), and quantitative PCR (qPCR). Although these methods have been used in the clinic, they have not been comprehensively compared. Here, we directly compared the performance of flow-FISH and qPCR to measure leukocytes' telomere length of healthy individuals and patients evaluated for telomeropathies, using TRF as standard. TRF and flow-FISH showed good agreement and correlation in the analysis of healthy subjects (R(2) = 0.60; p<0.0001) and patients (R(2) = 0.51; p<0.0001). In contrast, the comparison between TRF and qPCR yielded modest correlation for the analysis of samples of healthy individuals (R(2) = 0.35; p<0.0001) and low correlation for patients (R(2) = 0.20; p = 0.001); Bland-Altman analysis showed poor agreement between the two methods for both patients and controls. Quantitative PCR and flow-FISH modestly correlated in the analysis of healthy individuals (R(2) = 0.33; p<0.0001) and did not correlate in the comparison of patients' samples (R(2) = 0.1, p = 0.08). Intra-assay coefficient of variation (CV) was similar for flow-FISH (10.8 ± 7.1%) and qPCR (9.5 ± 7.4%; p = 0.35), but the inter-assay CV was lower for flow-FISH (9.6 ± 7.6% vs. 16 ± 19.5%; p = 0.02). Bland-Altman analysis indicated that flow-FISH was more precise and reproducible than qPCR. Flow-FISH and qPCR were sensitive (both 100%) and specific (93% and 89%, respectively) to distinguish very short telomeres. However, qPCR sensitivity (40%) and specificity (63%) to detect telomeres below the tenth percentile were lower compared to flow-FISH (80% sensitivity and 85% specificity). In the clinical setting, flow-FISH was more accurate, reproducible, sensitive, and specific in the measurement of human leukocyte's telomere length in comparison to qPCR. In conclusion, flow-FISH appears to be a more appropriate method for diagnostic purposes.
COVID‐19 is a complex disease manifesting in a broad severity spectrum and involving distinct organs and systems. Hyperinflammation, including complement over‐activation, has a pivotal role in severe ...COVID‐19 pathobiology, stimulating the inflammatory response, causing microangiopathy, platelet–neutrophil activation, and hypercoagulability. SARS‐CoV‐2 can directly activate the complement system by the classic, alternative, and lectin pathways, and infected cells can produce intracellular complement (the complesome). COVID‐19 severity appears to be associated with the degree of complement activation, and it has been hypothesized that patients with COVID‐19 may benefit from therapeutic complement inhibition. Different complement cascade molecules may be targeted with potential advantages and disadvantages. Which target(s) is the most effective and when is the best timing for intervention remain open questions. Early phase I and phase II clinical trials have shown promising but conflicting results, warranting phase III controlled randomized trials. Upstream complement inhibition appears to better and more effectively block hyperinflammation with potential clinical significance. Understanding how SARS‐CoV‐2 exploits the complement system can add precious information about the pathogenesis of other infections, inflammatory, and autoimmune diseases beyond COVID‐19.
. To implement a hybrid method, which combines analytical tracking and interaction simulation using Monte Carlo (MC) techniques, in order to model photon transport inside antiscatter grids (ASG) for ...x-ray imaging.
. A new tally was developed for PENELOPE (v.2018) and penEasy (v. 2020) MC code to simulate photon transmission through ASGs. Two established analytical algorithms from the literature were implemented in this tally. In addition, a new hybrid method was introduced by extending one of the analytical algorithms to include photon-interactions inside the grid, while preserving the imaged grid structure. Calculations of primary(TP),scatter(TS),and total(TT)grid transmissions in addition to the
factor (
=TP2/TT) were performed. The new tally was validated for a quadric geometry ASG, and experimental measurements with a PMMA phantom of several thicknesses. In addition, the contribution of the scatter inside the grid was studied for three interspace materials, and a high resolution image of the grid was simulated.
. An excellent agreement was found between the two analytical models compared with the quadric grid without scatter, and the hybrid method with the geometrical grid with scatter. Average deviations of 0.2% and 1.4% were found betweenTPandTSfor the hybrid method and quadric grid, while for the hybrid method and experimental measurements these values were 1% and 20%. Antiscatter grids with aluminium as interspace material had the highest amount of scatter from inside the grid to the final image, followed up by paper fibre and air. The high resolution image of the grid was equivalent using the quadric geometry or the hybrid mode.
. The hybrid method provides a means of studying scattered radiation from the antiscatter grid with the advantage of higher performance, with results that are consistent with a full quadric geometry simulation of the ASG.
Agudotherium gassenae is a poorly known non‐mammaliaform probainognathian cynodont from the Late Triassic of southern Brazil. It is known only by mandibular remains, and its affinities within ...Probainognathia are unclear. Furthermore, its phylogenetic affinities were never investigated through computational analyses. In this study, we described new lower jaw remains excavated from the type locality and performed the first phylogenetic investigation of this taxon. The new specimen provides further anatomical information. The rostral region of the lower jaw was poorly preserved in the type series, leading to the interpretation that A. gassenae had three lower incisors. The new specimen demonstrates the presence of four incisors. The phylogenetic analysis positioned A. gassenae as the sister group of Prozostrodontia. This hypothesis differs from that previously presented in the former description of the taxon, in which it was considered a non‐mammaliaform prozostrodont by means of character‐state comparisons.
This work proposes to study the impact of different voxelized heterogeneous breast models (gaussian centered - Gauss
; gaussian lower - Gauss
; and fitted equation patient-based on 3D realistic ...distribution (Fedon
2021) - Fit
) for dosimetry in mammography compared to a well-established homogeneous approximation. Influence of breast outer shape also was investigated by comparing semicylindric and anthropomorphic breasts.
By using the PENELOPE (v. 2018) + penEasy (v. 2020) MC code, simulations were performed to evaluate the normalized glandular dose (
) and the glandular depth dose (
(
)) for different breast characteristics and x-ray beam spectra.
The average
overestimation caused by homogeneous tissue approximation was 33.0%, with the highest values attributed to Gauss
and Fit
models, where fibroglandular tissue is concentrated deeper in the breast. The observed variation between anthropomorphic and semicylindrical breast shapes was, on average, 5.6%, legitimizing the latter approximation for breast dosimetry. Thicker breasts and lower energy beams resulted in larger overestimation caused by the homogeneous approach, while variations in
values among different heterogeneous models were higher for thinner breast and lower energy beams. Moreover, the depth where differences between
(
) for different breast models became maximum depends on the axial variation of fibroglandular tissue concentration between each model. The
(
) dependence results in a significant variation of the contribution of each breast depth to mean glandular dose (
) among the breast models studied.
Intercomparison between different breast models for dosimetry can be useful for estimating more accurate
values for population-based dosimetry, for exploring the use of 1D gaussian distribution for breast dosimetry, and for understanding the dose distributions inside the fibroglandular tissues, which could be a novel source of information for risk estimations.
Selenium (Se) at low concentrations can control root growth through interaction with hormone biosynthesis. Auxin and ethylene have been shown to control the root architecture, with most of the ...information obtained from the eudicots such Arabidopsis and Nicotiana tabacum. Here, we presented the effects of Se on auxin and ethylene pathways and examined their impact on primary metabolism and root system architecture in rice (Oryza Sativa L.) seedlings. Se treatment increased elongation of primary root, but decreased the number and length of lateral roots. Se led to decreased expression of genes associated with the biosynthesis of auxin and ethylene, concomitantly with reduced production of these hormones by the roots. Moreover, Se decreased the abundance of transcripts encoding auxin transport proteins. Indole-3-acetic acid (IAA) treatment overrode the repressive effect of Se on lateral root growth. The ethylene synthesis inhibitor l-a-(2-aminoethoxyvinyl)-glycine (AVG) increased elongation of primary root, whereas the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC) resulted in the opposite effect. Soluble sugars accumulate in roots of rice seedlings under Se treatment. Thus, Se modulates the formation of primary and lateral roots through alterations in auxin and ethylene, leading to new patterns of root architecture in rice seedlings.
Background
X‐ray breast imaging modalities are commonly employed for breast cancer detection, from screening programs to diagnosis. Thus, dosimetry studies are important for quality control and risk ...estimation since ionizing radiation is used.
Purpose
To perform multiscale dosimetry assessments for different breast imaging modalities and for a variety of breast sizes and compositions. The first part of our study is focused on macroscopic scales (down to millimeters).
Methods
Nine anthropomorphic breast phantoms with a voxel resolution of 0.5 mm were computationally generated using the BreastPhantom software, representing three breast sizes with three distinct values of volume glandular fraction (VGF) for each size. Four breast imaging modalities were studied: digital mammography (DM), contrast‐enhanced digital mammography (CEDM), digital breast tomosynthesis (DBT) and dedicated breast computed tomography (BCT). Additionally, the impact of tissue elemental compositions from two databases were compared. Monte Carlo (MC) simulations were performed with the MC‐GPU code to obtain the 3D glandular dose distribution (GDD) for each case considered with the mean glandular dose (MGD) fixed at 4 mGy (to facilitate comparisons).
Results
The GDD within the breast is more uniform for CEDM and BCT compared to DM and DBT. For large breasts and high VGF, the ratio between the minimum/maximum glandular dose to MGD is 0.12/4.02 for DM and 0.46/1.77 for BCT; the corresponding results for a small breast and low VGF are 0.35/1.98 (DM) and 0.63/1.42 (BCT). The elemental compositions of skin, adipose and glandular tissue have a considerable impact on the MGD, with variations up to 30% compared to the baseline. The inclusion of tissues other than glandular and adipose within the breast has a minor impact on MGD, with differences below 2%. Variations in the final compressed breast thickness alter the shape of the GDD, with a higher compression resulting in a more uniform GDD.
Conclusions
For a constant MGD, the GDD varies with imaging modality and breast compression. Elemental tissue compositions are an important factor for obtaining MGD values, being a source of systematic uncertainties in MC simulations and, consequently, in breast dosimetry.
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