Transforming patterned defects into dynamic poly-regional topographies in liquid crystal oligomers

We create high-aspect-ratio dynamic poly-regional surface topographies in a coating of a main-chain liquid crystal oligomer network (LCON). The topographies form at the topological defects in the director pattern organized in an array which are controlled by photopatterning of the alignment layer. The defect regions are activated by heat and/or light irradiation to form reversible topographic structures. Intrinsically, the LCON is rubbery and sensitive to temperature changes, resulting in shape transformations. We further advanced such system to make it light-responsive by incorporating azobenzene moieties. Actuation reduces the molecular order of the LCON coating that remains firmly adhered to the substrate which gives directional shear stresses around the topological defects. The stresses relax by deforming the surfaces by forming elevations or indents, depending on the type of defects. The formed topographies exhibit various features, including two types of protrusions, ridges and valleys. These poly-regional structures exhibit a large modulation amplitude of close to 60%, which is 6 times larger than the ones formed in liquid crystal networks (LCNs). After cooling or by blue light irradiation, the topographies are erased to the initial flat surface. A finite element method (FEM) model is adopted to simulate structures of surface topographies. These dynamic surface topographies with multilevel textures and large amplitude expand the application range, from haptics, controlled cell growth, to intelligent surfaces with adjustable adhesion and tribology.</p

Clinical and Pathological Characteristics of Autoimmune Hepatitis with Acute Presentation

Aim. To study the differences between acute presentation-autoimmune hepatitis (A-AIH) and chronic autoimmune hepatitis (C-AIH). Methods. Through long-term follow-up, 80 patients were included in our study by using the revised international autoimmune hepatitis group (IAIHG) score and were divided into acute and chronic groups for comparison. Results. No significant difference was found in the gender, age, IAIHG score (pretreatment/posttreatment), definite diagnosis rate, extrahepatic autoimmune disease, onset time, or treatment before biopsy between the acute and chronic groups. In terms of clinical symptoms, A-AIH patients were more prone to jaundice, anorexia, yellow urine, and detesting oil than C-AIH patients, but melena only occurred in chronic group (P<0.05). The acute group exhibited more severe injury upon histological evaluation, with lobular inflammation and bile duct injury, especially central necrosis of the lobule, more pronounced in this group (P<0.05). Conclusion. A-AIH had manifestations of acute hepatitis and presented cholestasis. Serum indicators could preliminarily distinguish A-AIH and C-AIH. Histologically, the primary manifestation of A-AIH was lobular inflammation, which was usually accompanied by lobular central necrosis. For the diagnosis of A-AIH, more attention should be paid to long-term follow-up. This study was registered at ClinicalTrials.gov (identifier: NCT02994537)