A viologen-derived luminescent material exhibiting photochromism, photocontrolled luminescence and selective detection of Cr2O72- in aqueous solution

Stable viologen-derived multifunctional smart materials exhibit widespread practical applications in many areas. In this study, a viologen-derived material with 4-fold interpenetrating diamondoid network, {[Cd(1,4-ndc)(cpbpy)]·2H2O}n, was successfully constructed based on asymmetrical N-(3-carboxyphenyl)-4,4'-bipyridinium (cpbpy) and 1,4-naphthalenedicarboxylic acid (1,4-H2ndc). The compound shows reversible photochromic behavior under a xenon lamp, which are proved by UV-vis spectra and EPR characterizations. Moreover, the compound with good photoluminescence properties displays photocontrolled luminescence quenching behaviors. Owing to its good water stability, the compound is then applied in luminescence sensing for the detection of Cr2O72- in aqueous solution. The corresponding luminescence quenching constant for Cr2O72- is KSV = 4.33 × 104 M-1, and the detection limit is 3.66 μM. Systematic investigations on the luminescence quenching mechanism suggest that the inner filter effect resulted in the selective detection of Cr2O72-. This study provides inspiration for the design and synthesis of target luminescent crystalline materials with rigid and asymmetric viologen-derived ligands.

[Associations of all-cause mortality with admission blood pressure variability during multiple hospitalizations in acute decompensated heart failure]

Objective: To investigate whether admission blood pressure (BP) variability during multiple hospitalizations is associated with all-cause mortality independent of baseline BP in acute decompensated heart failure (ADHF). Methods: Patients with ADHF admitted to the Department of Cardiology, The First Affiliated Hospital of Sun Yat-Sen University from September 2013 to December 2017 were retrospectively enrolled. The risk of all-cause mortality associated with indices of BP variability, including mean admission BPs, standard deviation of BP and coefficient of variation of BP during multiple hospitalizations was assessed, using Cox regression model. Results: A total of 1 006 ADHF patients (mean aged (69.3±13.5) years; 411 (40.8%) female; 670 (66.6%) with preserved ejection fraction) were enrolled. During a median follow-up of 1.54 years, 47.0% of patients died. In all ADHF patients, after adjusting for confounding factors, for every 1-standard deviation (SD) increase in SD and coefficient of variation (CV) of systolic BP, the risk of all-cause mortality increased by 10% and 11%, respectively (SD: HR, 1.10, 95%CI, 1.01-1.21, P=0.029, CV: HR, 1.11, 95%CI, 1.02-1.21, P=0.017); for every 1-SD increase in the mean of diastolic BP, the risk of all cause mortality decreased by 25% (HR, 0.75; 95%CI, 0.65-0.87; P<0.001). In ADHF patients with preserved ejection fraction, after accounted for potential confounders, higher SD and CV of admitted systolic and diastolic BP were significantly associated with higher risk of all-cause mortality, regardless of whether confounding factors were adjusted (P≤0.049); After adjusting for confounding factors, the risk of all-cause mortality increased by 18% and 19% for every 1-SD increase in SD and CV of systolic BP, while the risk of all-cause mortality increased by 11% and 15% for every 1-SD increase in SD and CV of diastolic BP. In ADHF patients with reduced ejection fraction, after adjusting for confounding factors, the higher the mean admission systolic BP during multiple hospitalizations, the lower the risk of total mortality (HR, 0.68; 95%CI, 0.47-1.00; P=0.049). Conclusions: In patients with ADHF, independent of baseline BP, BP variability during multiple hospitalizations was strong predictor of all-cause mortality.

Clinical value of contrast-enhanced ultrasound in transthoracic biopsy of malignant anterior mediastinal masses

Background

Given low incidence and high heterogeneity, the treatment strategies of anterior mediastinal masses (AMMs) are diverse based on pathology. The purpose of the study is to evaluate the usefulness of contrast-enhanced ultrasound (CEUS) in transthoracic biopsy of malignant AMMs when compared with that of ultrasound (US) alone and to screen lesions that are more suitable for CEUS evaluation and guidance.

Methods

We reviewed all the US- and CEUS-guided transthoracic core needle biopsy (CNB) of AMMs performed in National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College between July 2013 and April 2019. A total of 68 patients (mean age 36 years; male-female ration 1.6:1) who were suspected with malignant AMMs were enrolled in the study. Among them, 20 patients received pre-biopsy CEUS examination (CEUS group); 48 patients underwent conventional US examination and guidance (US group). Demographic, radiologic, pathologic, medical records, and biopsy procedure details were retrospectively reviewed and compared between the two groups.

Results

The display of internal necrosis areas was significantly improved when compared with that of the conventional US (70%, 30%; P=0.008). Specifically, CEUS improved the diagnostic accuracy of US-guided transthoracic biopsy (95.0%, 79.2%; P=0.210) and especially for AMMs exceeding 10 cm (100%, 68.2%; P=0.040) and carcinoma (100%, 0%; P=0.048). The number of punctures in US group and CEUS group was 2.6 and 4.4 times, respectively (P<0.001). In case of similar number of punctures (1 to 3 times), CEUS improved diagnostic accuracy when compared to that of the conventional US (100%, 75%; P=0.486). The technical success rate was 100% (68/68). In both groups, patients did not exhibit symptomatic complications such as bleeding, pneumothorax, or hemoptysis after the biopsy.

Conclusions

The application of CEUS in transthoracic biopsy of malignant AMMs improved diagnostic accuracy when compared with conventional US and especially played more important role in lesions exceeding 10 cm and presumptive clinical carcinoma.

The structure of a complex of the lactonohydrolase zearalenone hydrolase with the hydrolysis product of zearalenone at 1.60 Å resolution

Zearalenone hydrolase (ZHD) is an α/β-hydrolase that detoxifies and degrades the lactone zearalenone (ZEN), a naturally occurring oestrogenic mycotoxin that contaminates crops. Several apoenzyme and enzyme-substrate complex structures have been reported in the resolution range 2.4-2.6 Å. However, the properties and mechanism of this enzyme are not yet fully understood. Here, a 1.60 Å resolution structure of a ZHD-product complex is reported which was determined from a C-terminally His6-tagged ZHD crystal soaked with 2 mM ZEN for 30 min. It shows that after the lactone-bond cleavage, the phenol-ring region moves closer to residues Leu132, Tyr187 and Pro188, while the lactone-ring region barely moves. Comparisons of the ZHD-substrate and ZHD-product structures show that the hydrophilic interactions change, especially Trp183 Nℇ1, which shifts from contacting O2 to O12', suggesting that Trp183 is responsible for the unidirectional translational movement of the phenol ring. This structure provides information on the final stage of the catalytic mechanism of zearalenone hydrolysis.

[Human soluble dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin inhibits phagocytosis of Staphylococcus aureus by immature dendritic cells]

OBJECTIVE

To study the effect and mechanism of soluble dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (sDC-SIGN) on the phagocytosis of Staphylococcus aureus (S. aureus) by immature dendritic cells (imDCs).

METHODS

Flow cytometry was employed to examine the effect of sDC-SIGN on the phagocytosis of S. aureus by imDCs. Enzyme-linked immunosorbent assay (ELISA) was used to analyze the binging of sDC-SIGN to S. aureus, lipoteichoic acid (LTA) and lipopolysaccharides (LPS) and investigate the effect of the ligands mannan and LTA and anti-DC-SIGN antibodies 1C6 and 4H3 on the binging of sDC-SIGN to S. aureus.

RESULTS

sDC-SIGN inhibited the phagocytosis of S. aureus by imDCs. sDC-SIGN bound to S. aureus in a Ca(2+)-dependent manner. sDC-SIGN concentration-dependently bound to LTA, but not to LTA, and the binging of sDC-SIGN to S. aureus was blocked by mannan, LTA, 1C6 and 4H3.

CONCLUSION

sDC-SIGN preferentially binds to the carbohydrate constituents on S. aureus to affect the binding between membrane-bound DC-SIGN and S. aureus, thus suppressing the phagocytosis of S. aureus by imDCs.

Psychiatry teaching in China

A brief introduction of Psychiatry in China is presented, including the history, present status, content of textbooks and the arrangement of lecture hours and clinical practice.