[en] Under investigation in this paper is the AB system, which is used to describe the propagation of the wave packets in a marginally stable or unstable baroclinic shear flow. Introducing an auxiliary function $\mathrm{\alpha <!--\; ??\; -->}(\mathrm{\tau <!--\; ??\; -->})$, we predict irregular solitons and construct the high-order irregular dark solitons for the AB system, which are different from those in the existing literature. Affected by $\mathrm{\alpha <!--\; ??\; -->}(\mathrm{\tau <!--\; ??\; -->})$, the dark solitons are classified into three types, i.e., Type-I, Type-II and Type-III solitons. Type-I solitons propagate with unchanged shapes and velocities, Type-II solitons are shape-changing in the evolution, and Type-III solitons propagate with not only the shape variations but the appearances, splits, combinations and disappearances of some pits. We reveal that two Type-I solitons interact with each other elastically when they possess different velocities, and degenerate into the first-order solitons when they possess the same velocity. For the interactions between Type-II–Type-II, Type-II–Type-III, Type-III–Type-III solitons, it is found that $\mathrm{\alpha <!--\; ??\; -->}(\mathrm{\tau <!--\; ??\; -->})$ changes the interaction behaviors of the two solitons during the propagation. (paper)

[en] The association between intracranial internal carotid artery (IICA) calcification and lacunes, white matter hyperintensity (WMH), and cerebral microbleeds (CMBs) has been well researched. However, enlarged cerebral perivascular space (PVS) has not yet been reported to correlate with intracranial internal carotid artery calcification. Therefore, the primary aim of this study was to investigate the relationship between IICA calcification and enlarged PVS. A total of 189 patients with ischemic stroke in the middle cerebral artery territory who presented within 7 days of ictus from 2012 to 2015 were enrolled respectively. All patients were required to have undergone head computed tomography, magnetic resonance imaging, susceptibility-weighted magnetic resonance imaging, magnetic resonance angiography, or computed tomography angiography. Clinical characteristics were recorded. IICA calcification and enlarged PVS were semi-quantitatively evaluated, and the presence of lacunes, WMH, and CMBs was recorded. Of the 189 patients, 63.5% were male. Mean age of the patients was 68.6 ± 12.2 years. There were 104 patients with IICA calcification. Age, diabetes mellitus, lacunes, and white matter hyperintensity were significantly associated with IICA calcification (P < 0.05). Multivariate logistic regression analysis showed that age, diabetes mellitus, and lacunes were independent predictors of IICA calcification (P < 0.05). A lower risk of IICA calcification was found in patients with a higher enlarged PVS score (P = 0.004). Higher enlarged PVS scores were associated with a lesser degree of IICA calcification. There appears to be a relationship between reduced risk of IICA calcification and enlarged PVS. (orig.)