The development of a sensitive and practical electrochemiluminescence (ECL) bioassay relies on the use of ECL signal tags whose signal intensity is high and stable. In this work, strong ECL emission ...was achieved from metal organic framework (MOF) accelerator enriched quantum dots (CdTe), which were applied as an efficient ECL signal tag for trace biomarker detection. It is particularly noteworthy that a novel mechanism to drastically enhance the ECL intensity of CdTe is established because isoreticular metal organic framework-3 (IRMOF-3) with 2-amino terephthalic acid (2-NH2-BDC) as the organic ligand not only allows for loading a large amount of CdTe via the encapsulating effect and internal/external decoration but also functions as a novel coreactant accelerator for promoting the conversion of coreactant S2O8 2– into the sulfate radical anion (SO4 •–), further boosting the ECL emission of CdTe. On the basis of the simple sandwich immunoreaction approach, cardiac troponin-I antigen (cTnI), a kind of biomarker related with myocardial infarction, was chosen as a detection model using an IRMOF-3-enriched CdTe labeled antibody as the signal probe. This immunosensor demonstrated desirable assay performance for cTnI with a wide response range from 1.1 fg mL–1 to 11 ng mL–1 and a very low detection limit (0.46 fg mL–1). This suggested that the IRMOF-3-enriched CdTe nanocomposite strategy can integrate the coreactant accelerator and luminophore to significantly enhance the ECL intensity and stability, providing a direction for promising ECL tag preparation with broad applications.
Single-molecule white-light emission (SMWLE) has many advantages in practical applications; however, the fabrication of SMWLE from nonconjugated luminescent polymers, namely, clusteroluminogens ...(CLgens), is still a big challenge. Herein, the first example of linear nonconjugated polyesters with SMWLE is reported. Twenty-four kinds of nonconjugated aliphatic polyesters with tunable clusteroluminescence (CL) colors and efficiency were synthesized by the copolymerization of six epoxides and four anhydrides. Experimental and calculation results prove that, at the primary structure level, the balance of structural flexibility and rigidity via adjusting the side-chain length significantly enhances the efficiency of CL without wavelength change. However, altering the chemical structures of the monomer from succinic anhydride to trans-maleic anhydride (MA), cis-MA, and citraconic anhydride (CA), secondary structures of these polyesters change from helix to straight and folding sheet accompanied by gradually red-shifted CL from 460 to 570 nm due to the increase in through-space n–π* interactions, as demonstrated by the computational and experimental results. Then, pure SMWLE with CIE coordination (0.30, 0.32) based on overlapped short-wavelength and long-wavelength CL is achieved in CA-based polyesters. This work not only provides further insights into the emission mechanism of CL but also provides a new strategy to manipulate the properties of CL by regulating the hierarchical structures of CLgens.
The 3
-Gen OLED materials employing thermally-activated delayed fluorescence (TADF) combine advantages of first two for high-efficiency and low-cost devices. Though urgently needed, blue TADF ...emitters have not met stability requirement for applications. It is essential to elucidate the degradation mechanism and identify the tailored descriptor for material stability and device lifetime. Here, via in-material chemistry, we demonstrate chemical degradation of TADF materials involves critical role of bond cleavage at triplet state rather than singlet, and disclose the difference between bond dissociation energy of fragile bonds and first triplet state energy (BDE-E
) is linearly correlated with logarithm of reported device lifetime for various blue TADF emitters. This significant quantitative correlation strongly reveals the degradation mechanism of TADF materials have general characteristic in essence and BDE-E
could be the shared "longevity gene". Our findings provide a critical molecular descriptor for high-throughput-virtual-screening and rational design to unlock the full potential of TADF materials and devices.
Shewanella oneidensis MR‐1, a model strain of exoelectrogenic bacteria (EEB), plays a key role in environmental bioremediation and bioelectrochemical systems because of its unique respiration ...capacity. However, only a narrow range of substrates can be utilized by S. oneidensis MR‐1 as carbon sources, resulting in its limited applications. In this study, a rapid, highly efficient, and easily manipulated base‐editing system pCBEso was developed by fusing a Cas9 nickase (Cas9n (D10A)) with the cytidine deaminase rAPOBEC1 in S. oneidensis MR‐1. The C‐to‐T conversion of suitable C within the base‐editing window could be readily and efficiently achieved by the pCBEso system without requiring double‐strand break or repair templates. Moreover, double‐locus simultaneous editing was successfully accomplished with an efficiency of 87.5%. With this tool, the key genes involving in N‐acetylglucosamine (GlcNAc) or glucose metabolism in S. oneidensis MR‐1 were identified. Furthermore, an engineered strain with expanded carbon source utilization spectra was constructed and exhibited a higher degradation rate for multiple organic pollutants (i.e., azo dyes and organoarsenic compounds) than the wild‐type when glucose or GlcNAc was used as the sole carbon source. Such a base‐editing system could be readily applied to other EEB. This study not only enhances the substrate utilization and pollutant degradation capacities of S. oneidensis MR‐1 but also accelerates the robust construction of engineered strains for environmental bioremediation.
Cheng and coworkers have successfully developed a rapid and highly efficient base editing system‐pCBEso in Shewanella oneidensis MR‐1. With this tool, the authors identified the key genes involving in the N‐acetyl‐glucosamine metabolism and rapidly constructed an engineered strain with enhanced substrate utilization and pollutant degradation capacities. Such a base editing tool could be readily applied to other exoelectrogenic bacteria (EEB) and promote the application of EEB in bioremediation.
In view of the increasing concerns for environmental problems caused by the widespread use of antibiotics, there is an urgent demand to develop effective technologies for antibiotics removal from ...pharmaceutical wastewater. For this purpose, photocatalysis has been developed as an important advanced oxidation technology possessing remarkable prospective, and thus, the semiconductor photocatalysts are currently attracting unprecedented research attention. Herein, we report the fabrication of composite materials based on nitrogen-doped carbons and cadmium sulfide semiconductors (CdS/NC–T ) derived solely from cadmium metal–organic frameworks (Cd–MOF) through a facile in situ carbonization method, as well as their application as viable photocatalysts toward tetracycline degradation under visible irradiation. It was revealed that cadmium and sulfur species in Cd–MOF precursors assembled to form CdS nanoparticles (NPs), which were deposited simultaneously on nitrogen-doped carbon scaffolds to afford CdS/NC–T composites during carbonization processes. PXRD and TEM studies on as-prepared CdS/NC–T materials indicated the formation of crystalline hexagonal (Wurtzite) CdS NPs on carbonaceous supports. These CdS/NC–T composites were further studied for photocatalytic tetracycline degradation in aqueous solutions under visible irradiation, among which CdS/NC–500 exhibited the highest TC degradation efficiency of ca. 83% within 1 h. It was found that the photocatalytic performance of CdS/NC–T depended largely on carbonization temperature, which suggested great potentials of the proposed synthetic pathway in engineering of new visible-light-driven photocatalysts.
Double hydrosilylation of alkynes represents a straightforward method to synthesize bis(silane)s, yet it is challenging if α‐substituted vinylsilanes act as the intermediates. Here, a ...cobalt‐catalyzed regiodivergent double hydrosilylation of arylacetylenes is reported for the first time involving this challenge, accessing both vicinal and geminal bis(silane)s with exclusive regioselectivity. Various novel bis(silane)s containing Si−H bonds can be easily obtained. The gram‐scale reactions could be performed smoothly. Preliminarily mechanistic studies demonstrated that the reactions were initiated by cobalt‐catalyzed α‐hydrosilylation of alkynes, followed by cobalt‐catalyzed β‐hydrosilylation of the α‐vinylsilanes to deliver vicinal bis(silane)s, or hydride‐catalyzed α‐hydrosilylation to give geminal ones. Notably, these bis(silane)s can be used for the synthesis of high‐refractive‐index polymers (nd up to 1.83), demonstrating great potential utility in optical materials.
A cobalt‐catalyzed regiodivergent double hydrosilylation of arylacetylenes involving unique hydrosilylation of α‐substituted vinylsilane intermediates has been developed, to regioselectively access vicinal and geminal bis(silane)s bearing silicon‐hydrogen bonds. These valuable bis(silyl) compounds can be used as polymerizable monomers for the synthesis of polymers possessing high refractive indices up to 1.83.
The relationship between exposure to famine in early life and the risk of ascending aorta dilatation (AAD) in adulthood is still unclear; therefore, we aimed to examine the association in the Chinese ...population. We investigated the data of 2598 adults who were born between 1952 and 1964 in Guangdong, China. All enrolled subjects were categorised into five groups: not exposed to famine, exposed during fetal period, and exposed during early, mid or late childhood. AAD was assessed by cardiac ultrasound. Multivariate logistic regression and interaction tests were performed to estimate the OR and CI on the association between famine exposure and AAD. There were 2598 (943 male, mean age 58·3 ± 3·68 years) participants were enrolled, and 270 (10·4 %) subjects with AAD. We found that famine exposure (OR = 2·266, 95 % CI 1·477, 3·477, P = 0·013) was associated with elevated AAD after adjusting for multiple confounders. In addition, compared with the non-exposed group, the adjusted OR for famine exposure during fetal period, early, mid or late childhood were 1·374 (95 % CI 0·794, 2·364, P = 0·251), 1·976 (95 % CI 1·243, 3·181, P = 0·004), 1·929 (95 % CI 1·237, 3·058, P = 0·004) and 2·227 (95 % CI 1·433, 3·524, P < 0·001), respectively. Subgroup analysis showed that the effect of famine exposure on the association with AAD was more pronounced in female, current smokers, people with BMI ≥ 24 kg/m2 and hypertensive patients. We observed that exposure to famine during early life was linked to AAD in adulthood.
The link between total cholesterol (TC) and all-cause and specific mortality has not been elucidated. Herein, we aimed to evaluate the effect of TC levels on all-cause, cardiovascular disease (CVD), ...and cancer mortality.
All data analyzed were obtained from the National Health and Nutrition Examination Survey 1999-2014. The relationship between levels of TC and mortality was determined through Cox proportional hazard regression analysis coupled with multivariable adjustments. Two-piecewise linear regression models and Cox models with penalized splines were applied to explore nonlinear and irregular shape relationships. Kaplan-Meier survival curve and subgroup analyses were conducted.
The sample studied comprised 14,662 men and 16,025 women, categorized as 25,429 adults aged 18-65 and 5,258 adults over 65 years old. A total of 2,570 deaths were recorded. All-cause, cardiovascular, and cancer mortality showed U-curve associations after adjusting for confounding variables in the restricted cubic spline analysis. Hazard ratios (HRs) of all-cause and cancer mortality were particularly negatively related to TC levels in the lower range < 200 mg/dL, especially in the range < 120 mg/dL (HR 1.97; 95% CI 1.38, 2.83, HR 2.39; 95% CI 1.21, 4.71, respectively). However, the HRs of cardiovascular disease mortality in the range < 120 mg/dL were the lowest (HR 0.60; 95% CI 0.15, 2.42). In the upper range, a TC range of ≥ 280 mg/dL was correlated with mortality as a result of CVD and cancer (HR 1.31; 95% CI 0.87, 1.97 and HR 1.22; 95% CI 0.82, 1.79). The lowest cumulative survival rate of all-cause mortality was recorded in the lowest TC-level group, while the lowest cumulative survival rate of CVD mortality was recorded in the highest TC-level group.
A nonlinear association of TC level with all-cause, cancer, and CVD mortality in the American population was observed, suggesting that too low or too high serum total cholesterol levels might correlate with adverse outcomes.
The association between heart failure (HF) and intestinal inflammation caused by a disturbed intestinal microbiota in infants with congenital heart disease (CHD) was investigated.
Twenty infants with ...HF and CHD who were admitted to our hospital between October 2021 and March 2022 were included in this study. Twenty age- and sex-matched infants without HF at our hospital were selected as the control group. Faecal samples were obtained from each participant and analysed by enzyme-linked immunoassay and 16 S rDNA sequencing to assess intestinal inflammatory factors and the microbiota.
The levels of intestinal inflammatory factors, including IL-1β, IL-4, IL-6, IL-17 A and TNF-α, were greatly increased, while the levels of IL-10 were significantly decreased in the HF group compared to the control group (p < 0.05). The intestinal microbial diversity of patients in the HF group was markedly lower than that in the control group (p < 0.05). The abundance of Enterococcus was significantly increased in the HF group compared to the control group (p < 0.05), but the abundance of Bifidobacterium was significantly decreased in the HF group compared to the control group (p < 0.05). The diversity of the intestinal microbiota was negatively correlated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the intestinal tract but was positively correlated with that of IL-10. The abundance of Enterococcus was positively associated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the intestinal tract but was negatively correlated with that of IL-10. NT-proBNP was positively associated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the HF group but was negatively correlated with that of IL-10. The heart function score was positively associated with the levels of IL-1β, IL-4, IL-6 and TNF-α in the HF group but was negatively correlated with that of IL-10.
Infants with CHD-related HF had a disordered intestinal microbiota, decreased diversity of intestinal microbes, increased levels of pathogenic bacteria and decreased levels of beneficial bacteria. The increased abundance of Enterococcus and the significant decrease in the diversity of the intestinal microbiota may exacerbate the intestinal inflammatory response, which may be associated with the progression of HF.
Chromium is a common heavy metal widely present in aquatic environments. Cost-effective remediation of chromium-contaminated environment can be realized by microbial reduction of Cr(VI) to Cr(III). ...The genus Aeromonas species is one of such Cr(VI) reducers, whose reduction mechanism remains unrevealed and the main factors governing the Cr(VI) reduction pathways are unknown yet. In this work, the performances and mechanisms of Cr(VI) anaerobic reduction by Aeromonas hydrophila ATCC 7966 were investigated. This strain exhibited excellent Cr(VI) resistance and could utilize a suite of electron donors to support Cr(VI) bioreduction. The Cr(VI) bioreduction processes involved both extracellular (the metal-reducing and respiratory pathway) and intracellular reaction pathways. Adding anthraquinone-2,6-disulfonate or humic acid as a mediator substantially enhanced the Cr(VI) bioreduction. The forms and distribution of the Cr(VI) bioreduction products were affected by the medium composition. Soluble organo-Cr(III) complexes were identified as the main Cr(VI) reduction products when basal salts medium was adopted. Given the environmental ubiquity of the genus Aeromonas, the findings in this work may facilitate a better understanding about the transformation behaviors and fates of Cr(VI) in environments and provide useful clues to tune the bioremediation of chromium-contaminated environments.
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•A. hydrophila ATCC 7966 had an excellent Cr(VI) resistance and reduction ability.•Extracellular and intracellular pathways were involved in the Cr(VI) bioreduction.•Medium composition affected the formation of Cr(VI) reduction products.•Organo-Cr(III) complexes were the main Cr(VI) reduction products by Aeromonas.
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