Background
Although the benefits of breast screening and early diagnosis are known for reducing breast cancer mortality rates, the effects and risks of low radiation doses to the cells in the breast ...are still ongoing topics of study.
Purpose
To study specific energy distributions (f(z,Dg)$f(z,D_{g})$) in cytoplasm and nuclei of cells corresponding to glandular tissue for different x‐ray breast imaging modalities.
Methods
A cubic lattice (500 μm length side) containing 4064 spherical cells was irradiated with photons loaded from phase space files with varying glandular voxel doses (Dg$D_{g}$). Specific energy distributions were scored for nucleus and cytoplasm compartments using the PENELOPE (v. 2018) + penEasy (v. 2020) Monte Carlo (MC) code. The phase space files, generated in part I of this work, were obtained from MC simulations in a voxelized anthropomorphic phantom corresponding to glandular voxels for different breast imaging modalities, including digital mammography (DM), digital breast tomosynthesis (DBT), contrast enhanced digital mammography (CEDM) and breast CT (BCT).
Results
In general, the average specific energy in nuclei is higher than the respective glandular dose scored in the same region, by up to 10%. The specific energy distributions for nucleus and cytoplasm are directly related to the magnitude of the glandular dose in the voxel (Dg$D_{g}$), with little dependence on the spatial location. For similar Dg$D_{g}$ values, f(z,Dg)$f(z,D_{g})$ for nuclei is different between DM/DBT and CEDM/BCT, indicating that distinct x‐ray spectra play significant roles in f(z,Dg)$f(z,D_{g})$. In addition, this behavior is also present when the specific energy distribution (Fg(z)$F_{g}(z)$) is considered taking into account the GDD in the breast.
Conclusions
Microdosimetry studies are complementary to the traditional macroscopic breast dosimetry based on the mean glandular dose (MGD). For the same MGD, the specific energy distribution in glandular tissue varies between breast imaging modalities, indicating that this effect could be considered for studying the risks of exposing the breast to ionizing radiation.
Acquired and congenital aplastic anemias recently have been linked molecularly and pathophysiologically by abnormal telomere maintenance. Telomeres are repeated nucleotide sequences that cap the ends ...of chromosomes and protect them from damage. Telomeres are eroded with cell division, but in hematopoietic stem cells, maintenance of their length is mediated by telomerase. Accelerated telomere shortening is virtually universal in dyskeratosis congenita, caused by mutations in genes encoding components of telomerase or telomere-binding protein (TERT, TERC, DKC1, NOP10, or TINF2). About one-third of patients with acquired aplastic anemia also have short telomeres, which in some cases associate with TERT or TERC mutations. These mutations cause low telomerase activity, accelerated telomere shortening, and diminished proliferative capacity of hematopoietic progenitors. As in other genetic diseases, additional environmental, genetic, and epigenetic modifiers must contribute to telomere erosion and ultimately to disease phenotype. Short telomeres also may cause genomic instability and malignant progression in these marrow failure syndromes. Identification of short telomeres has potential clinical implications: it may be useful in dyskeratosis congenita diagnosis, in suggesting mutations in patients with acquired aplastic anemia, and for selection of suitable hematopoietic stem cell family donors for transplantation in telomerase-deficient patients.
We present a Galerkin multisymplectic Lie group variational integrator. It is suitable for dynamical systems defined on a two dimensional space–time and the integrator allows arbitrary convergence ...orders independently for both dimensions. As an example we use geometrically exact beam dynamics where a slender structure is modelled as a centre line with a cross section at every point. The Lie group in question is the special Euclidean group in three-dimensional space, SE(3), which we parametrize using unit dual quaternions. This allows a very simple and efficient interpolation method to be used, which additionally prevents shear locking present in more naive discretizations of geometrically exact beams.
•Multisymplectic Lie-group variational integrators of arbitrary order.•No shear locking.•Efficient unit dual-quaternion based interpolation of rotations and positions.•Convergence rates which are higher than the known theoretical lower bounds.
Aspergillus fumigatus (A. fumigatus) is an environmental fungus and a human pathogen. Neutrophils are critical effector cells during the fungal infections, and neutropenia is a risk factor for the ...development of pulmonary aspergillosis. Neutrophil extracellular traps (NETs) are released by neutrophils in response to A. fumigatus and inhibit the conidial germination. In this work, we observed that the receptors TLR2, TLR4, and Dectin‐1 were dispensable for the A. fumigatus induced NET release. In contrast CD11b/CD18 was critical for the NET release in response to A. fumigatus conidia, and this required the CD11b I‐domain‐mediated recognition, whereas the blockade of the CD11b lectin domain did not affect the A. fumigatus induced NET release. A. fumigatus induced NET release relied on the activity of spleen tyrosine kinase (Syk), Src family kinase(s), and class IA PI3 kinase δ. Although A. fumigatus promoted histone citrullination, this process was dispensable for the NET release in response to A. fumigatus conidia. The A. fumigatus induced NET release required the reactive oxygen species generation by the NOX2 complex, in a downstream pathway requiring CD11b/CD18, Src kinase family activity, Syk and PI3K class IA δ. Our findings thus reveal the signaling pathways involved in the formation of NETs in response to A. fumigatus.
Mac‐1 (CD11b/CD18) mediates NET release in response to A. fumigatus by a Syk/PI3K Iδ dependent pathway independently of histone citrullination.
The intent of the present work was to evaluate the potential of four macroalgae prevalent in Europe, namely
,
sp.,
and
, for application in functional foods, either in the direct form or as extracts. ...Accordingly, nutritional composition, the content of phytochemical antioxidants, and the inhibitory ability of key enzymes with impacts on obesity and diabetes (α-glucosidase and pancreatic lipase) or on arterial pressure (angiotensin-I converting enzyme), were evaluated. Overall, protein, lipid, ash and fiber contents of the macroalgae ranged from 9⁻24% dw, 0.5⁻3.0% dw, 20⁻32% dw, and 37⁻45% dw, respectively, making them good candidates for nutritional supplementation of several foods, particularly due to their mineral and fiber contents. In addition, brown macroalgae, in particular
stood out for its superior phenolic content, which was reflected by its high antioxidant ability and inhibition towards α-glucosidase activity (0.032 mg/mL of hydroacetonic extract inhibited 50% of the enzyme activity).
To investigate the longitudinal alterations of subbasal corneal nerves in patients with infectious keratitis (IK) during the acute phase, cessation of treatment, and the recovery phase by in vivo ...confocal microscopy (IVCM).
Prospective, longitudinal, case-control, single-center study.
Fifty-six eyes of 56 patients with the diagnosis of bacterial (n=28), fungal (n=15), or Acanthamoeba (n=13) keratitis were included in the study. Thirty eyes of 30 normal volunteers constituted the control group.
Corneal sensation and serial IVCM of the central cornea were performed prospectively using the Heidelberg Retina Tomograph 3/Rostock Cornea Module (Heidelberg Engineering, Heidelberg, Germany). The IVCM images were assessed at 3 time points: at the acute phase (first visit to the cornea service), at cessation of antimicrobial treatment, and up to 6 months after the resolution of infection.
Total nerve number and length, main nerve trunks, branching, and corneal sensation were assessed during the follow-up period.
Corneal nerves were reduced significantly during the acute phase in eyes with IK compared with controls across all subgroups, with total nerve length of 5.47±0.69 mm/mm2 versus 20.59±1.06 mm/mm2 (P<0.0001). At the cessation of treatment, corneal nerves in patients with IK had regenerated, including total nerve length (8.49±0.94 mm/mm2; P=0.02) and nerve branch length (4.80±0.37 mm/mm2; P=0.005). During the recovery phase, after resolution of infection, corneal nerves regenerated further, including total nerve length (12.13±1.97 mm/mm2; P=0.005), main nerve trunk length (5.80±1.00 mm/mm2; P=0.01), and nerve branch length (6.33±0.76 mm/mm2; P=0.003) as compared with the acute phase, but were still significantly lower when compared with controls (P<0.05 for all parameters). Corneal degeneration and regeneration correlated with corneal sensation (r=0.47; P=0.0009).
Patients with IK who sustain profound loss of corneal nerves during the acute phase of infection demonstrate increased corneal nerve density during the first 6 months after the resolution of infection. However, despite significant nerve regeneration, corneal nerve density does not recover fully and remains low compared to controls. By providing an objective methodology to monitor corneal re-innervation, IVCM adds potentially important findings that may have implications for clinical management and surgical planning.
In summary, our study emphasizes that CCP should not be transfused late in the course of disease, when the clinical course is driven by inflammation. Google Scholar Casadevall A, Scharff MD. Serum ...therapy revisited: animal models of infection and development of passive antibody therapy. Development and validation of a treatment benefit index to identify hospitalized patients with COVID-19 who may benefit from convalescent plasma.
Several new early sauropodomorphs have been described from Carnian South American strata that include the oldest unambiguous dinosaurs worldwide. Hence, these findings suggest a high diversity in the ...origin of the group. Here we offer three hypotheses based in novel data that can explain this diversity at the first branches of the long evolutionary tree of the sauropodomorphs. The first hypothesis explains that the Triassic specimens excavated from Brazilian strata are not coeval owing to the lack of stratigraphic control. Fortunately, new studies are constraining the age of Triassic outcrops from Brazil. The second hypothesis suggests an overstated diversity in response to the unknown ontogenetic pathways adopted by early dinosaurs. This hypothesis still demands new findings in order to clarify these ontogenetic pathways. The third hypothesis supports a high diversity in the same time span in response to distinct ecological roles adopted by the early sauropodomorphs. Indeed, there are specimens with different tooth morphologies, indicating diverse feeding strategies. This hypothesis is supported in an ecomorphological analysis derived from discrete anatomical traits. Therefore, although facing many conflicting questions regarding alpha taxonomy of Carnian sauropodomorphs, new discoveries and alternative approaches are leading towards a better understanding of the early evolution of Sauropodomorpha.
Over the last decades, most information on the mechanisms underlying tolerance to drought has been gained by considering this stress as a single event that happens just once in the life of a plant, ...in contrast to what occurs under natural conditions where recurrent drought episodes are the rule. Here we explored mechanisms of drought tolerance in coffee (Coffea canephora) plants from a broader perspective, integrating key aspects of plant physiology and biochemistry. We show that plants exposed to multiple drought events displayed higher photosynthetic rates, which were largely accounted for by biochemical rather than diffusive or hydraulic factors, than those submitted to drought for the first time. Indeed, these plants displayed higher activities of RuBisCO and other enzymes associated with carbon and antioxidant metabolism. Acclimation to multiple drought events involved the expression of trainable genes related to drought tolerance and was also associated with a deep metabolite reprogramming with concordant alterations in central metabolic processes such as respiration and photorespiration. Our results demonstrate that plants exposed to multiple drought cycles can develop a differential acclimation that potentiates their defence mechanisms, allowing them to be kept in an ‘alert state’ to successfully cope with further drought events.
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