The electrocatalytic oxidation of dopamine (DA) was studied by electrochemical approaches at a carbon ionic liquid electrode (CILE) modified with the composite film of nafion and L-aspartic acid (NL-CILE). The CILE was fabricated by replacing non-conductive organic binders with a room-temperature hydrophobic ionic liquid, 1-butyl-3-methyl-imidazolium hexafluorophosphate. The composite film of NL was used as matrix to adsorb DA and catalyze the oxidation of DA in phosphate buffer solution (PBS). The electrochemical response of DA was investigated at the NL-CILE, the traditional carbon paste electrode (TCPE), CILE and the nafion modified CILE (N-CILE) in 0.1M PBS (pH 7.4), respectively. The results showed the superiority of NL-CILE to N-CILE, CILE and TCPE in terms of provision of higher sensitivity, faster electron transfer and better reversibility. Under optimum condition, the oxidation peak current was rectilinear with DA concentration range from 0.1μM to 0.1mM, with a detection limit of 0.03μM (S/N=3) by differential pulse voltammetry. The proposed method was applied to determine DA in samples successfully.

OBJECTIVES: With the increase in aging population in China, elderly Crohn's disease (CD) patients need to receive more attention. This study aims to explore the clinical characteristics and disease process of elderly onset CD (EOCD) patients in a single center. METHODS: From January 2002 to January 2022, a total of 221 patients with CD from the Seventh Medical Center of Chinese PLA General Hospital were enrolled. According to the Montreal CD classification standard, the patients were further divided into 4 groups: an EOCD group (≥60 years old, n=25), a middle age onset CD (MOCD) group (40-59 years old, n=46), a young onset CD (YOCD) group (17-40 years old, n=131), and a childhood onset CD (COCD) group (6-16 years old, n=19). We compared the clinical characteristics and long-term prognosis among them. RESULTS: Females were predominant in the EOCD group (15/25, 60%). The number of people without smoking in the EOCD group (80%) was lower than that in COCD group (100%), higher than that in the YOCD group (70.2%) and the MOCD group (69.6%) (all P<0.05). Patients with perianal diseases at diagnosis were rare in the EOCD group (0%), lower than that in the COCD group (21.1%) and the YOVD group (19.8%) (all P<0.05). Stenosis was the most common disease behavior in the EOCD group (63.0%), significantly higher than that in the COCD group (15.8%), the YOCD group (36.6%) and the MOCD group (43.5%) (all P<0.05). The EOCD group was easier to be misdiagnosed as tumor (24%), higher than that in the COCD group (0%), the YOCD group (6.9%) and the MOCD group (19.6%) (all P<0.05). The EOCD group was prone to comorbidities (52%), and 20% of them were complicated with multiple comorbidities (P<0.05). During the follow-up, the all-cause mortality of EOCD was 12%, and the CD-related mortality was 8%, which was significantly higher than the other groups (all P<0.05). The use of immunosuppressants in the EOCD group (4.8%) was lower than that in the COCD group (12.8%), the YOCD group (16.8%) and the MOCD group (16.1%), but there was no statistical significance among the 4 groups (P=0.467). In addition, there was no significant difference in the rate of intestinal resection among the 4 groups (P=0.062). CONCLUSIONS In EOCD patients, females were predominant, smoking was less common, and they were prone to comorbidity. At the initial stage of diagnosis, it is easy to be misdiagnosed as tumor, and the disease behavior mainly showed stricture type, less complicated with perianal diseases. During the follow-up, all-cause mortality and CD-related mortality of EOCD patients were significantly higher than those of the non-elderly onset CD patients.
Female ; Middle Aged ; Humans ; Aged ; Child ; Adult ; Adolescent ; Young Adult ; Crohn Disease/epidemiology* ; Prognosis ; Constriction, Pathologic ; Aging ; Hospitals, General