Construction of an Artificial Sequential Light-Harvesting System and White-Light Material Utilizing Supramolecular Gels.

The molecular (pyren-1-yloxy)-acetic acid (Py) with excellent fluorescence properties was synthesized from 1-hydroxypyrene (Hp) and formed a supramolecular gel with an acid-base stimulus response in dimethylformamide and water. On the basis of gel, the fluorescent dye perylene 3, 9-dicarbxylic acid, and rhodamine 6g were added successively to construct a step-by-step artificial light-harvesting system, so that the fluorescence color changed from blue-purple to green to red, and white light emission was realized by adjusting the ratio of donors and acceptors.

An anti-freeze fluorescent organogel with rapid shape-forming properties for constructing artificial light harvesting systems used in extremely cold environments.

Using polyvinyl alcohol (PVA) and perylene-3,9-dicarboxylic acid (PDA) as raw materials, a new anti-freeze (-50 °C) fluorescent organogel with rapid shape-forming (2 h) properties was synthesised based on a certain proportion of the binary solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO). Then, an artificial light-harvesting system (ALHS) used in extremely cold environments was successfully constructed by mixing fluorescent dyes sulphorhodamine101 (SR101) and rhodamine 6G (R6G) into them as acceptors.

Monomer-Promoting Asymmetric Kinetic Resolution-Alternating Copolymerization To Afford AAB-Type Copolyesters.

Living copolymerization of mixed monomers can enrich the diversity of copolymer materials with well-defined performance via controlling both monomers and stereosequences. However, periodic sequence-controlled living copolymerization of same-type monomers with more than two components in synthetic polymer science remains a challenge. In this work, a new method of monomer-promoting asymmetric kinetic resolution-alternating copolymerization can let a tricomponent mixture of l-lactide (S,S-LA or l-LA) and two enantiomeric isomers of racemic tropic acid cyclic esters (tropicolactone) be polymerized into sequence-controlled -(ASASBS)n- type biodegradable copolyesters (the subscript S presents the configuration and A and B present lactic acid units and tropic acid units, respectively), and diblock copolymers of -(ASASBS)n-b-(ARARBR)n- can further be obtained upon addition of R,R-LA (d-LA). Compared to previous asymmetric kinetic resolutions of racemic chemicals via polymerization or organic reactions, no enantiopure catalyst/initiator is required in this system. After the resolution and alternating copolymerization of S,S-LA and rac-tropicolactone, the ee value of unreacted tropicolactone can reach 99.4%. The alternating probability between tropicolactone and lactide monomers is more than 96% in periodic sequence polymers of -(ASASBS)n-. The tetracomponent mixture of rac-lactide and rac-tropicolactone can be copolymerized into an alternating copolymer with a -((ASASBS)x-ran-(ARARBR)y)n- structure, in which the stereoselective linkage probability of 95% after S,S-lactide (R,R-lactide) followed by S-tropicolactone (R-tropicolactone) keeps very high too.

Shape-controlled hollow Cu2O@CuS nanocubes with enhanced photocatalytic activities towards degradation of tetracycline.

In view of recent advances in photodegradation of antibiotics, low cost and stable photocatalyst remain rare. In this article, shape-controlled Cu2O@CuS nanocubes with the larger specific surface area were successfully prepared via a simple template-engaged strategy. Cu2O nanocubes were synthesized through a reduction method as original templates, the core-shelled Cu2O@CuS nanocubes were formed by sulphuration with Na2S as sulphur source, and the Cu2O core can be incompletely removed by Na2S2O3 to generate the Cu2O@CuS nanoboxes. Herein, hierarchical nanoboxes with two-layered Cu2O@CuS were used as photocatalyst materials for photocatalytic degradation of tetracycline (TC). The obtained nanocubes manifested high specific surface area (39.65 m2 g-1) and large pore volume (12.3 cm3 g-1). The degradation performance for TC was investigated in detail, including the effect of parameters such as photocatalyst, pH and catalyst dosage. The results indicated that degradation efficiencies were higher than 90% under visible light. Moreover, the degradation efficiency was 71% after six times.

[Distribution Characteristics of Antibiotics and Antibiotic Resistance Genes in Manure and Surrounding Soil of Poultry Farm in Ningxia].

Antibiotics and antibiotic resistance genes (ARGs) in livestock and poultry manure pose potential ecological risks. In order to understand the distribution characteristic of antibiotics and ARGs in manure and surrounding soils of poultry farms in Ningxia, the poultry manure and relative soil samples were collected from 12 layers of different poultry breeding farms. The compositions of antibiotics and ARGs in the samples were analyzed using UPLC-MS/MS and HT-qPCR. The results showed that:① tetracycline, aminoglycoside, and sulfonamide were the dominant antibiotics in poultry manure. The types and contents of antibiotics in poultry manure were different in different breeding periods. There were more types of antibiotics in the brooding period, the average content was high, and the initial stage showed the opposite trend. ② A small amount of antibiotics was detected in the surrounding soil only 20 m away from the poultry farm, and the poultry farm had little effect on the distribution of antibiotics in the surrounding soil. The content of quinolone in the soils with poultry manure application was significantly higher than that in the control and surrounding soil. ③ We detected 132-168 ARGs in poultry manure, and the number of aminoglycosides and tetracycline was higher. The relative abundance of ARGs in the rearing period was highest, and the initial stage showed the opposite trend. The total relative abundance of ARGs in the brooding period was highest, but the terminal period showed the opposite. There were 110 ARGs in poultry manure during all breeding periods. ④ There were 23-105 ARGs in the soils, and the number of aminoglycoside was highest, followed by multidrug ARGs. The poultry farm had a great effect on the number and relative abundance of ARGs in the surrounding soil. For example, the number and relative abundance of ARGs in the surrounding soil of poultry farms gradually decreased with the increase in the distance from the poultry farms. The number and relative abundance of ARGs in the soil with applied poultry manure were significantly increased; however, these values were lower than those in the soil 20 m away from the poultry farm. ⑤ ß-lactamases, aminoglycosides, and macrolide lincosamide-streptogramin B (MLSB) ARGs were all at risk of horizontal movement in manure, and chloramphenicol ARGs were at risk of horizontal movement in soil. Correlation analysis showed that the relative abundance of aminoglycoside, tetracycline, sulfonamide, ß-lactamase, and MLSB were not significantly correlated with their contents. ⑥ Different types of ARGs had related co-occurrence phenomena, such as the positive correlation between the relative abundance of ARGs in poultry manure, and aminoglycoside and ß-lactamases, MGEs, multidrugs and vancomycins. The relative abundances of ARGs in soil, aminoglycoside and tetracyclines, vancomycins, sulfonamides, and MLSBs; tetracyclines and MLSBs; etc., all showed a significant positive correlation. In short, the co-occurrence among the relative abundance of ARGs in soil was significantly stronger than that in poultry manure. These results could provide the theoretical basis for the site selection of poultry farms, the selection of antibiotic types and dosages for large-scale breeding of laying hens, and the application of poultry manure.

Synthesis of Linear to Cyclic Polylactide via a One-Pot Step-Wise Ring-Opening Polymerization and Back-Biting Reaction of Ring Closure Using Magnesium Complexes.

The controllable synthesis of cyclic polylactide remains a challenging topic so far. In this work, a new strategy of one-pot step-wise ring-opening polymerization (ROP) followed by a back-biting reaction of ring closure was reported, in which one magnesium atrane-like complex {N,N-bis[3,5-di-cumyl-2-benzyloxy]-[2-(2-aminoethoxy)ethoxy]magnesium} was utilized to initiate the ROP of lactide using 4-dimethylaminopyridine as a co-catalyst; then, macrocyclic polylactides were liberated out via increasing temperature after complete depletion of the monomer in which a back-biting reaction was utilized as a ring-closure method. The living feature at the first ROP stage can be proved well by the controllable molecular weights ranging from 3.10 to 34.70 kDa and narrow molecular weight distributions of linear polylactides obtained after quenching the reaction. The final cyclic polylactides with molecular weights (vs polystyrene) ranging from 2.50 to 16.10 kDa can be achieved too after the back-biting reaction of ring closure. Although a shoulder peak at the gel permeation chromatography profile appears when the ratio of monomer:initiator is high up to 100:1 or 200:1, this system is suitable for the controllable syntheses of cyclic polylactides with desirable modest molecular weights.

Study of serum miR-518 and its correlation with inflammatory factors in patients with gestational diabetes mellitus complicated with hypertensive disorder complicating pregnancy.

OBJECTIVE: Gestational diabetes mellitus (GDM) and hypertensive disorder complicating pregnancy (HDCP) are common complications during pregnancy. This study estimated the correlation of serum miR-518 and inflammatory factors in GDM complicated with HDCP patients (GDM&HDCP). METHODS: Total 240 pregnant women were enrolled, including 118 cases with GDM alone, 57 cases with GDM&HDCP, and 65 healthy pregnant women. The expressions of serum miR-518 and PPARα were detected by RT-qPCR. The clinical diagnostic efficacy of miR-518 for GDM and GDM&HDCP was analyzed via ROC curve. Pearson coefficient was used to analyze the correlation between miR-518 and serum inflammatory factors (hs-CRP, IL-6, and TNF-α), and the relevance between peroxisome proliferator-activated receptor α (PPARα) and serum inflammatory factors. The targeted binding of miR-518 and PPARα was verified using dual-luciferase assay. RESULTS: Serum miR-518 was highly-expressed in GDM and GDM&HDCP patients, but far higher in GDM&HDCP patients. Serum miR-518 level > 1.815 could assist the diagnosis of GDM (81.53% sensitivity and 100% specificity). Serum miR-518 expression was positively-correlated with serum inflammatory factors. miR-518 targeted PPARα and PPARα was lowly-expressed in the serum of GDM and GDM&HDCP patients. PPARα was negatively-linked with serum inflammatory factors. CONCLUSION: High expression of miR-518 assists the diagnosis of GDM and GDM&HDCP, and miR-518 regulates the serum inflammatory factors by inhibiting PPARα.

Evaluation of cesarean delivery rates in different levels of hospitals in Jiangsu Province, China, using the 10-Group classification system.

OBJECTIVE: To compare cesarean delivery (CD) rates in referral and non-referral hospitals in Maternal Safety Collaboration in Jiangsu province, China. METHODS: Sixteen participants (4 referral hospitals, 12 non-referral hospitals) from Drum Tower Hospital Collaboration for Maternal Safety reported CD rates in 2019 using ten-group classification system and maternal/neonatal morbidity and mortality. RESULTS: A total of 22,676 CDs were performed among 52,499 deliveries and the average CD rate was 43.2% (range 34.8-69.6%). CD rate in non-referral hospitals (44.7%) was significantly higher than it was in referral hospitals (40.4%, p < .001). Term singleton cephalic nulliparous women with spontaneous labor (Group 1) or induced labor (Group 2a) had higher CD rates if they were cared in non-referral hospitals compared with those in referral hospitals (Group 1: 11.8% vs. 4.4%, p < .001; Group 2a: 29.1% vs. 21.3%, p < .001). In non-referral hospitals, CD rate in Group 5 and the proportion of Group 5 to the overall population were also significantly higher than those in referral hospitals (98.5% vs. 92.5%, p < .001; and 21.0% vs. 14.5%, p < .001). CONCLUSION: To decrease the CD rate, we need to take efforts in decreasing unnecessary operations for term singleton cephalic nulliparous women and increasing the rate of trial of labor after CD.

Efficient artificial light-harvesting systems based on aggregation-induced emission in supramolecular gels.

Based on a new designed acyl hydrazone gelator (G2), we developed a supramolecular organogel in glycol with two different hydrophobic fluorescent dyes, namely rhodamine B (RhB) and acridine red, as acceptors. Both the G2@gel-RhB and G2@gel-acridine red systems showed high levels of energy-transfer efficiency and high fluorescence quantum yields.

A new strategy for constructing artificial light-harvesting systems: supramolecular self-assembly gels with AIE properties.

An artificial light-harvesting system (ALHS) has been designed and constructed based on supramolecular organogels made of a simple hydrazide-functionalized benzimidazole derivative (HB), as well as the fluorescent dye rhodamine B (RhB). RhB acted as a good acceptor to realize the energy-transfer process with good efficiency based on a HB/RhB assembly, which showed considerable fluorescence resonance energy transfer (FRET) efficiency of 53% for the energy transfer process. Remarkably, the obtained system showed superior color conversion abilities, converting blue light into orange light. By properly tuning the donor to acceptor ratio, bright orange light emission was achieved with a high fluorescence quantum yield of 35.5%. This system exhibited promise for applications relating to visible-light photo-transformation.

Intelligent writable material based on a supramolecular self-assembly gel.

A simple dual acylhydrazone-functionalized gelator (G1) has been designed and synthesized, and it was found to form a supramolecular organogel (G1-gel) in a mixed solvent of DMF-H2O. The gelator solution shows brilliant blue light upon mixing with Mg2+; this blue light can be erased by saliva or CO32-. Owing to this characteristic, a smart erasable writable material was prepared.