Photo/Mechanical/Acidic Multi-Stimuli Responses and Information Encryption Design of Acylhydrazone Derivative.

Stimuli-responsive crystalline materials have received much attention for being potential candidates of smart materials. However, the occurrence of polymorphism-driven stimuli responses in crystalline materials remains interesting but rare. Herein, three polymorphs of an acylhydrazone derivative, N'-[(E)-(1-benzofuran-2-yl) methylidene] pyridine -4-carbohydrazide (BFMP) were prepared. Form-1 undergoes a photomechanical response via E→Z photoisomerization under UV irradiation, accompanied by a decrease in fluorescence intensity and a change from colorless to yellow. Two types of Z→E thermal isomerization mechanisms with significant differences in conversion rate were observed at different temperatures in form-1. The solid-melt-solid transition has a faster conversion rate compared to the solid-solid transition due to freedom from lattice confinement. The transition from form-2 to form-3 can be achieved under grinding, coupled with a significant decrease in fluorescence intensity. The similar molecular stacking pattern of form-2 and form-3 provides a structural basis for the grinding-induced crystalline transition behavior. In addition, the presence of the pyridine moiety imparts an acidochromic property. The combination of photochromism and acidochromism explores the possible applications of acylhydrazone derivatives in information encryption.

Appendicitis combined with Meckel's diverticulum obstruction, perforation, and inflammation in children: Three case reports.

BACKGROUND: Meckel's diverticulum is a common congenital malformation of the small intestine, with the three most common complications being obstruction, perforation, and inflammation. To date, only a few cases have been reported worldwide. In children, the clinical symptoms are similar to appendicitis. As most of the imaging features are nonspecific, the preoperative diagnosis is not precise. In addition, the clinical characteristics are highly similar to pediatric acute appendicitis, thus special attention is necessary to distinguish Meckel's diverticulum from pediatric appendicitis. Patients with poor disease control should undergo laparoscopic exploration to avoid serious complications, including intestinal necrosis, intestinal perforation and gastrointestinal bleeding. CASE SUMMARY: This report presents three cases of appendicitis in children combined with intestinal obstruction, which was caused by fibrous bands (ligaments) arising from the top part of Meckel's diverticulum, diverticular perforation, and diverticular inflammation. All three patients, aged 11-12 years, had acute appendicitis as their initial clinical presentation. All were treated by laparoscopic surgery with a favorable outcome. A complete dataset including clinical presentation, diagnostic imaging, surgical information, and histopathologic findings was also provided. CONCLUSION: Preoperative diagnosis of Meckel's diverticulum and its complications is challenging because its clinical signs and complications are similar to those of appendicitis in children. Laparoscopy combined with laparotomy is useful for diagnosis and treatment.