Herein, we report an interesting finding about the new application of oxytetracycline (OTC), as a fluorescent probe for the detection of calcium ion (Ca2+), which proved that it can offer an expeditious, highly sensitive, and selective detection method for Ca2+. Upon the addition of Ca2+, the fluorescence of OTC could be significantly enhanced with rapid response and high sensitivity, and achieved a good limit of detection as low as 125 nM in aqueous solution. The complex formed via Ca2+ coordinating to the hydroxyl group of OTC contributes to the fluorescence enhancement, which has been proved by several characterization methods including UV-vis analysis, binding constant determination, and fluorescence titration. The method avoided complexity for EDTA measurement of Ca2+ in running water as proposed previously. Taking advantage of good availability, stability and operability, the OTC was further successfully applied to the detection of Ca2+ in a real environment. Graphical Abstract.BACKGROUND Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a dynamic but reversible disease. AIM We aimed to clarify whether the change in Chinese Group on the Study of Severe Hepatitis B-ACLF (COSSH-ACLF) grade in HBV-ACLF patients can be used to predict prognosis, and to explore the appropriate conditions for performing urgent liver transplantation. METHODS We assessed the COSSH-ACLF grades of HBV-ACLF patients at different time points from June 2013 to May 2019 at Huashan Hospital in Shanghai, China, and analyzed the relationship between the change in grade and patient prognosis. RESULTS A total of 207 HBV-ACLF patients were enrolled, of which 79 underwent urgent liver transplantation. Their COSSH-ACLF grades were calculated at diagnosis, 3-7 days after diagnosis, and on the final day. Most of the final ACLF grades were consistent with their corresponding grades at days 3-7 after diagnosis (62.5%), while only 44.5% were in accordance with the initial grades at diagnosis. In patients who had a poor prognosis (initial ACLF-3 and ACLF-2 or -3 at days 3-7), the 28-day survival rate was 93.3% in those who underwent transplantation and 6.8% in those who did not (P  less then  0.0001). However, in patients who had a good prognosis (ACLF-0 or ACLF-1 at days 3-7), the 28-day survival rate was 100% in transplanted patients and 91.5% in non-transplanted patients (P = 0.236). CONCLUSIONS Reevaluation of the COSSH-ACLF grade 3-7 days after diagnosis could potentially show an indication for urgent liver transplantation.BACKGROUND Most gut microbiome studies have been performed using stool samples. However, the small intestine is of central importance to digestion, nutrient absorption, and immune function, and characterizing its microbial populations is essential for elucidating their roles in human health and disease. AIMS To characterize the microbial populations of different small intestinal segments and contrast these to the stool microbiome. METHODS Male and female subjects undergoing esophagogastroduodenoscopy without colon preparation were prospectively recruited. Luminal aspirates were obtained from the duodenum, jejunum, and farthest distance reached. A subset also provided stool samples. 16S rRNA sequencing was performed and analyses were carried out using CLC Genomics Workbench. RESULTS 16S rRNA sequencing identified differences in more than 2000 operational taxonomic units between the small intestinal and stool microbiomes. Firmicutes and Proteobacteria were the most abundant phyla in the small intestine, and Bacteroidetes were less abundant. In the small intestine, phylum Firmicutes was primarily represented by lactic acid bacteria, including families Streptococcaceae, Lactobacillaceae, and Carnobacteriaceae, and Proteobacteria was represented by families Neisseriaceae, Pasteurellaceae, and Enterobacteriaceae. The duodenal and FD microbial signatures were markedly different from each other, but there were overlaps between duodenal and jejunal and between jejunal and FD microbial signatures. In stool, Firmicutes were represented by families Ruminococcaceae, Lachnospiraceae, Christensenellaceae, and Proteobacteria by class Deltaproteobacteria. CONCLUSIONS The small bowel microbiome is markedly different from that in stool and also varies between segments. These findings may be important in determining how compositional changes in small intestinal microbiota contribute to human disease states.BACKGROUND/AIMS We examined the effects of proton pump inhibitors (PPIs) on gastric antral ulcers induced by non-steroidal anti-inflammatory drugs in re-fed mice and the role of capsaicin-sensitive afferent nerves (CSANs) in the protective effects of PPIs on the antral mucosa. METHODS Male mice were administered indomethacin after 2 h of re-feeding of diet after a 24-h fast, and gastric lesions were examined 24 h after indomethacin dosing. The effects of PPIs (lansoprazole and omeprazole), histamine H2-receptor antagonists (H2-RAs, famotidine, ranitidine), capsaicin and misoprostol on the formation of antral ulcers induced by indomethacin were examined. Functional ablation of CSANs was caused by pretreatment of mice with a high dose of capsaicin. RESULTS Indomethacin produced lesions selectively in the gastric antrum in re-fed conditions.  https://www.selleckchem.com/products/alpha-conotoxin-gi.html  Formation of antral ulcers was not affected by H2-RAs, but inhibited by PPIs, capsaicin and misoprostol. The anti-ulcer effect of lansoprazole was 30 times stronger than that of omeprazole. Antral ulcers induced by indomethacin were markedly aggravated in mice with ablated CSANs. The effects of PPIs and capsaicin on ulcer formation were inhibited by ablation of CSANs, pretreatment with a capsaicin receptor antagonist (capsazepine/ruthenium red) and an inhibitor of nitric oxide synthesis (L-NAME). However, the inhibitory effect of misoprostol was not prevented by the ablation of CSANs or drugs. CONCLUSIONS The results suggested that CSANs play an important role in protection of the antral mucosa and that both lansoprazole and omeprazole are capable of preventing NSAID-induced antral ulcers by activating CSANs.