We present a Raman study of Ar+-bombarded graphene samples with increasing ion doses. This allows us to have a controlled, increasing, amount of defects. We find that the ratio between the D and G ...peak intensities, for a given defect density, strongly depends on the laser excitation energy. We quantify this effect and present a simple equation for the determination of the point defect density in graphene via Raman spectroscopy for any visible excitation energy. We note that, for all excitations, the D to G intensity ratio reaches a maximum for an interdefect distance ∼3 nm. Thus, a given ratio could correspond to two different defect densities, above or below the maximum. The analysis of the G peak width and its dispersion with excitation energy solves this ambiguity.
Beaches combined with sloping structures are frequently the first element of defense to protect urban areas from the impact of extreme coastal flooding events. However, these structures are rarely ...designed for null wave overtopping discharges, accepting that waves can pass above the crest and threat exposed elements in hinterland areas, such as pedestrians, urban elements and buildings, and vehicles. To reduce risks, Early Warning Systems (EWSs) can be used to anticipate and minimize the impacts of flooding episodes on those elements. A key aspect of these systems is the definition of non-admissible discharge levels that trigger significant impacts. However, large discrepancies in defining these discharge levels and the associated impacts are found among the existing methods to assess floodings. Due to the lack of standardization, a new conceptual and quantitative four-level (from no-impact to high-impact) categorization of flood warnings (EW-Coast) is proposed. EW-Coast integrates and unifies previous methods and builds on them by incorporating field-based information. Thus, the new categorization successfully predicted the impact level on 70%, 82%, and 85% of the overtopping episodes affecting pedestrians, urban elements and buildings, and vehicles, respectively. This demonstrates its suitability to support EWSs in areas vulnerable to wave-induced flooding.
We present a detailed analysis of the kinetic and mass terms associated with the Landau gauge gluon propagator in the presence of dynamical quarks, and a comprehensive dynamical study of certain ...special kinematic limits of the three-gluon vertex. Our approach capitalizes on results from recent lattice simulations with (
2
+
1
) domain wall fermions, a novel nonlinear treatment of the gluon mass equation, and the nonperturbative reconstruction of the longitudinal three-gluon vertex from its fundamental Slavnov–Taylor identities. Particular emphasis is placed on the persistence of the suppression displayed by certain combinations of the vertex form factors at intermediate and low momenta, already known from numerous pure Yang–Mills studies. One of our central findings is that the inclusion of dynamical quarks moderates the intensity of this phenomenon only mildly, leaving the asymptotic low-momentum behavior unaltered, but displaces the characteristic “zero crossing” deeper into the infrared region. In addition, the effect of the three-gluon vertex is explored at the level of the effective gauge coupling, whose size is considerably reduced with respect to its counterpart obtained from the ghost-gluon vertex. The main upshot of the above considerations is the further confirmation of the tightly interwoven dynamics between the two- and three-point sectors of QCD.
Recent advances have improved our understanding of the renin‐angiotensin system (RAS). These have included the recognition that angiotensin (Ang)‐(1‐7) is a biologically active product of the RAS ...cascade. The identification of the ACE homologue ACE2, which forms Ang‐(1‐7) from Ang II, and the GPCR Mas as an Ang‐(1‐7) receptor have provided the necessary biochemical and molecular background and tools to study the biological significance of Ang‐(1‐7). Most available evidence supports a counter‐regulatory role for Ang‐(1‐7) by opposing many actions of Ang II on AT1 receptors, especially vasoconstriction and proliferation. Many studies have now shown that Ang‐(1‐7) by acting via Mas receptor exerts inhibitory effects on inflammation and on vascular and cellular growth mechanisms. Ang‐(1‐7) has also been shown to reduce key signalling pathways and molecules thought to be relevant for fibrogenesis. Here, we review recent findings related to the function of the ACE2/Ang‐(1‐7)/Mas axis and focus on the role of this axis in modifying processes associated with acute and chronic inflammation, including leukocyte influx, fibrogenesis and proliferation of certain cell types. More attention will be given to the involvement of the ACE2/Ang‐(1‐7)/Mas axis in the context of renal disease because of the known relevance of the RAS for the function of this organ and for the regulation of kidney inflammation and fibrosis. Taken together, this knowledge may help in paving the way for the development of novel treatments for chronic inflammatory and renal diseases.
Guillain-Barré syndrome (GBS) is a rare, but potentially fatal, immune-mediated disease of the peripheral nerves and nerve roots that is usually triggered by infections. The incidence of GBS can ...therefore increase during outbreaks of infectious diseases, as was seen during the Zika virus epidemics in 2013 in French Polynesia and 2015 in Latin America. Diagnosis and management of GBS can be complicated as its clinical presentation and disease course are heterogeneous, and no international clinical guidelines are currently available. To support clinicians, especially in the context of an outbreak, we have developed a globally applicable guideline for the diagnosis and management of GBS. The guideline is based on current literature and expert consensus, and has a ten-step structure to facilitate its use in clinical practice. We first provide an introduction to the diagnostic criteria, clinical variants and differential diagnoses of GBS. The ten steps then cover early recognition and diagnosis of GBS, admission to the intensive care unit, treatment indication and selection, monitoring and treatment of disease progression, prediction of clinical course and outcome, and management of complications and sequelae.
Much recent attention has been devoted towards unraveling the microscopic optoelectronic properties of hybrid organic-inorganic perovskites. Here we investigate by coherent inelastic neutron ...scattering spectroscopy and Brillouin light scattering, low frequency acoustic phonons in four different hybrid perovskite single crystals: MAPbBr_{3}, FAPbBr_{3}, MAPbI_{3}, and α-FAPbI_{3} (MA: methylammonium, FA: formamidinium). We report a complete set of elastic constants characterized by a very soft shear modulus C_{44}. Further, a tendency towards an incipient ferroelastic transition is observed in FAPbBr_{3}. We observe a systematic lower sound group velocity in the technologically important iodide-based compounds compared to the bromide-based ones. The findings suggest that low thermal conductivity and hot phonon bottleneck phenomena are expected to be enhanced by low elastic stiffness, particularly in the case of the ultrasoft α-FAPbI_{3}.
Background
Varicella‐zoster virus (VZV) is a human neurotropic virus that remains in a latent state within ganglionic neurons throughout the entire neuroaxis after the primary infection. When herpes ...zoster (HZ) leads to trigeminal involvement, the ophthalmic division is the most implicated. COVID‐19 has emerged as a viral cause of severe acute respiratory syndrome that has spread all over the world in the last months. Co‐infection with COVID‐19 and other viruses has been reported, but sparsely, and involving the respiratory viruses.
Methods
The case of a co‐infection of COVID‐19 with VZV is reported, and the literature reviewed.
Results
A 39‐year‐old immunocompetent man presented with oligosymptomatic infection with COVID‐19, which evolved to left facial HZ, affecting the three divisions of the trigeminal nerve. The co‐infection was remotely registered, being the respiratory viruses, especially influenza, the most commonly cited association. However, the present case illustrates the emergence of a latent virus infection, which might be favored by the inflammatory response to the former agent (COVID‐19). This reaction ascended from the nasal cavity, where trigeminal branches are also placed.
Conclusions
The emergence of latent VZV infection in this rare presentation might illustrate an effect, at least locally, of COVID‐19. This virus possibly induced a retrograde reactivation of VZV in a young immunocompetent patient.
Prostaglandins (PGs) are immuno-active lipids that mediate the immune response in invertebrates and vertebrates. In insects, PGs play a role on different physiological processes such as reproduction, ...ion transport and regulation of cellular immunity. However, it is unclear whether PGs play a role in invertebrate's humoral immunity, and, if so, which immune signaling pathways would be modulated by PGs. Here, we show that Aedes aegypti gut microbiota and Gram-negative bacteria challenge induces prostaglandin production sensitive to an irreversible inhibitor of the vertebrate cyclooxygenase, acetylsalicylic acid (ASA). ASA treatment reduced PG synthesis and is associated with decreased expression of components of the Toll and IMD immune pathways, thereby rendering mosquitoes more susceptible to both bacterial and viral infections. We also shown that a cytosolic phospholipase (PLAc), one of the upstream regulators of PG synthesis, is induced by the microbiota in the midgut after blood feeding. The knockdown of the PLAc decreased prostaglandin production and enhanced the replication of Dengue in the midgut. We conclude that in Ae. aegypti, PGs control the amplitude of the immune response to guarantee an efficient pathogen clearance.
The diagnosis of periodontal disease is commonly based on objective evaluations of the patient's medical/dental history as well as clinical and radiographic examinations. However, periodontal disease ...should also be evaluated subjectively through measures that quantify its impact on oral health‐related quality of life. The aim of this study was to evaluate the impact of periodontal disease on quality of life among adolescents, adults and older adults. A systematic search of the literature was performed for scientific articles published up to July 2015 using electronic databases and a manual search. Two independent reviewers performed the selection of the studies, extracted the data and assessed the methodological quality. Thirty‐four cross‐sectional studies involving any age group, except children, and the use of questionnaires for the assessment of the impact of periodontal disease on quality of life were included. Twenty‐five studies demonstrated that periodontal disease was associated with a negative impact on quality of life, with severe periodontitis exerting the most significant impact by compromising aspects related to function and esthetics. Unlike periodontitis, gingivitis was associated with pain as well as difficulties performing oral hygiene and wearing dentures. Gingivitis was also negatively correlated with comfort. The results indicate that periodontal disease may exert an impact on quality of life of individuals, with greater severity of the disease related to greater impact. Longitudinal studies with representative samples are needed to ensure validity of the findings.
Raman scattering is used to study disorder in graphene subjected to low energy (90eV) Ar+ ion bombardment. The evolution of the intensity ratio between the G band (1585cm−1) and the disorder-induced ...D band (1345cm−1) with ion dose is determined, providing a spectroscopy-based method to quantify the density of defects in graphene. This evolution can be fitted by a phenomenological model, which is in conceptual agreement with a well-established amorphization trajectory for graphitic materials. Our results show that the broadly used Tuinstra-Koenig relation should be limited to the measure of crystallite sizes, and allows extraction of the Raman relaxation length for the disorder-induced Raman scattering process.
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