Stress analysis on the irregular surface of visco-porous piezoelectric half-space subjected to a moving load

Response of moving load over a surface is an intriguing problem of mechanics to determine the stability and strength of a structure. Owing to this the present theoretical framework is devoted to find the stresses and electrical displacements of an irregular visco-porous piezoelectric half-space originated due to a uniformly moving line load. Expressions for normal stress, shear stress and electrical displacements have been derived in closed form. Effect of irregularity depth, irregularity factors and frictional coefficient on the stresses and electrical displacements are delineated graphically. Numerical demonstration of procured results is interpreted by means of graphs for two different materials, namely PZT-5A and PZT-7. A comparative study emphasising various irregularity (parabolic, rectangular and no irregularity) is among the salient features of the study.

Clinical and radiological risk factors for rupture of vertebral artery dissecting aneurysm: significance of the stagnation sign

OBJECTIVE The aim of this study was to investigate the clinical and radiological factors associated with the rupture of a vertebral artery dissecting aneurysm (VADA) and to evaluate whether the stagnation sign is a significant risk factor for rupture of VADA. METHODS Clinical and radiological variables of 117 VADAs treated in a tertiary hospital from September 2008 to December 2020 were retrospectively reviewed. The stagnation sign is defined as the finding of contrast agent remaining in the lesion until the venous phase of angiography. Univariate and multivariate analyses were executed to reveal the associations between rupture status and VADA characteristics. RESULTS The rate of ruptured VADAs was 29.1% (34 of 117) and the stagnation sign was observed in 39.3% (46 of 117). Fusiform shape (OR 5.105, 95% CI 1.591–16.383, p = 0.006), irregular surface (OR 4.200, 95% CI 1.412–12.495, p = 0.010), posterior inferior cerebellar artery (PICA) involvement (OR 3.788, 95% CI 1.288–11.136, p = 0.016), and the stagnation sign (OR = 3.317, 95% CI 1.131–9.732, p = 0.029) were significantly related to rupture of VADA in multivariate logistic regression analysis. CONCLUSIONS This study showed that fusiform shape, irregular surface, PICA involvement, and the stagnation sign may be independent risk factors for the rupture of VADA. Therefore, when the potential risk factors are observed in unruptured VADA, more aggressive treatment rather than follow-up or medical therapy may be considered.

When the Frequencies of Sensitization and Elicitation of Allergic Reaction Do Not Correlate—The Case of Apple Gibberellin-Regulated Protein Tested in an Italian Population

Background: The literature reports describing allergic symptoms against apples in the patients sensitized to the gibberellin-regulated proteins (GRPs) suggested the presence of an allergenic GRP in this fruit.Objective: This study aimed to assess the presence of a GRP protein in apples and investigate its allergenicity.Methods: The protein was isolated and identified by the classical biochemical methods. The bioinformatics tools were used for similar searches and molecular modeling. The immunological features were investigated using the multiplex FABER test. Clinical data were collected by the allergy specialists.Results: A GRP was detected in the apple peel and pulp and it was named applemaclein. This protein displays 94% of sequence identity with peamaclein, Pru p 7, representing the prototype of this allergen family. The applemaclein molecular model shows a very irregular surface with grooves/clefts that may potentially accommodate small molecular ligands. In a population of 4,721 patients in Italy, 187 (4.0%) were sensitized to any allergenic GPR. Of those, 115 (61.5%), 61 (32.6%), 30 (16.0%), and 99 (52.9%) had immunoglobulin E (IgE) to apple, peach, pomegranate, and cypress GRP, respectively. However, in a cohort of the patients in Italy, most individuals IgE positive to the apple GRP did not report allergic reactions against this fruit.Conclusion: Compared with the peach Pru p 7, applemaclein shows some different structural features and higher sensitization frequency, which is often not associated with allergic reactions against apple. Further studies are needed to understand a possible correlation between the applemaclein structural properties, the interaction with still unknown molecules, and immunological behavior.

Surfaces with canonical map of maximum degree

We use the Borisov-Keum equations of a fake projective plane and the Borisov-Yeung equations of the Cartwright-Steger surface to show the existence of a regular surface with canonical map of degree 36 and of an irregular surface with canonical map of degree 27. As a by-product, we get equations (over a finite field) for the Z / 3 \mathbb {Z}/3 -invariant fibres of the Albanese fibration of the Cartwright-Steger surface and show that they are smooth.

A myricaceous male inflorescence with pollen in situ from the middle Eocene of Europe

The late middle Eocene lacustrine filling of a maar lake at Eckfeld (Eifel Hills, Rhineland-Palatinate, western Germany) has provided four specimens of male inflorescences (catkins) in different stages of anthesis, each with pollen preserved in situ. The appearance of the successive stages together with triporate pollen showing an irregular surface and a myricoid micro-ornamentation clearly suggests an assignment of the fossil catkins to the Myricaceae. The material is described as a new genus and new species and represents the oldest record of male catkins for the family. The in situ preserved pollen grains are comparable to dispersed grains of Triatriopollenites excelsus.