A Chalcone-based Fluorescence Probe for H2S Detecting Utilizing ESIPT Coupled ICT Mechanism.

The accurate and effective identification of hydrogen sulfide holds great significance for environmental monitoring. Azide-binding fluorescent probes are powerful tools for hydrogen sulfide detection. We combined the 2'-Hydroxychalcone scaffold with azide moiety to construct probe Chal-N3, the electron-withdrawing azide moiety was utilized to block the ESIPT process of 2'-Hydroxychalcone and quenches the fluorescence. The fluorescent probe was triggered with the addition of hydrogen sulfide, accompanied by great fluorescence intensity enhancement with a large Stokes shift. With excellent fluorescence properties including high sensitivity, specificity selectivity, and wider pH range tolerance, the probe was successfully applied to natural water samples.

Advance of CE and CEC in phytochemical analysis (2012­2013).

This article presents an overview of the advance of CE and CEC in phytochemical analysis, based on the literature not mentioned in our previous review papers [Chen, X. J., Zhao, J., Wang, Y. T., Huang, L. Q., Li, S. P., Electrophoresis 2012, 33, 168­179], mainly covering the years 2012­2013. In this article, attention is paid to online preconcentration, rapid separation, and sensitive detection. Selected examples illustrate the applicability of CE and CEC in biomedical, pharmaceutical, environmental, and food analysis. Finally, some general conclusions and future perspectives are given.

Lignin-derived polyphenols with enhanced antioxidant activities by chemical demethylation and their structure-activity relationship.

Lignin valorization to biobased polyphenols antioxidants is increasingly attractive in the modern industry due to their inherent phenolic structures. Herein, lignin-derived polyphenols with enhanced antioxidant activities were prepared from the most available technical lignin including organosolv lignin (OL), alkali lignin (AL), and enzyme lignin (EL) by iodocyclohexane (ICH) chemical demethylation. The structural evolution of lignin indicated that the CAr-OCH3 group and the CAr-O-Calkyl side-chain could be effectively transformed into the CAr-OH group, resulting in a significant increase of the phenolic-OH content and a slight decrease of the molecular weight. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH·) scavenging activity was in the order of ICHOL-24 > ICHAL-24 > ICHEL-24 ≈ FA > BHT, and the IC50 value of ICHOL-24 was 0.56 times lower than that of BHT. The structure-activity relationship demonstrated the activities were quasi-linearly related to phenolic-OH contents and could be affected by molecular weights. The H/G/S proportions of lignin could be an indicator for accurate screening of efficient lignin-derived polyphenols antioxidants (LPA). It was preliminarily estimated to have economic feasibility for producing LPA from technical lignin by demethylation compared with synthetic or natural antioxidants. This work will help to develop efficient biobased antioxidants for lignin valorization.

[Treadmill exercise test in patients with coronary artery myocardial bridging].

OBJECTIVE: To observe treadmill exercise test (TET) characteristics in patients with myocardial bridging (MB). METHODS: TET results from January 2003 to December 2010 were retrospectively analyzed in 156 patients with confirmed MB diagnosis. MB patients were divided into smoking group (68 cases) and non-smoking group (88 cases). Coronary angiography results were used to analyze the relations between MB length, myocardial ischemia and exercising duration. RESULTS: (1) MB was documented on two coronary arteries in 2 patients (1%), MB was detected in single artery in 154 patients (99%), of whom 146 cases were located at left anterior descending artery, 8 cases were located at right coronary artery. The degree of narrowing of MB was graded 1 (less than 50%) in 16 patients (10%), grade 2 (50% to 75%) in 108 patients (69%) and grade 3 (greater than 75%) in 32 patients (21%). The length of MB ranged between 4 to 40 mm, MB length was less than 10 mm in 40 patients (26%), between 11 to 20 mm in 48 patients (31%), between 21 to 30 mm in 44 patients (28%), greater than 31 mm in 24 patients (15%). (2) TET positive rate was 41% (64/156) and the TET positive rate was significantly higher in smoking group than in non-smoking group [57% (39/68) vs. 28% (25/88, P < 0.01)]. (3) The length of MB was positively related to the ST-segment depression (r = 0.723, P < 0.01) and negatively related to exercising duration (r = -0.828, P < 0.01). Heart rate was positively related to the ST-segment depression (r = 0.368, P < 0.01). CONCLUSIONS: TET may serve as a good test to assess myocardial ischemia in patients with MB. The length of MB is positively related with myocardial ischemia and negatively related with exercising duration. Smoking might increase myocardial ischemic incidence in MB patients, MB patients should be advised to stop smoking.