Effect of different hydrogen evolution rates at cathode on bioelectrochemical reduction of CO2 to acetate.

Microbial electrosynthesis (MES) offers a promising approach for converting CO2 into valuable chemicals such as acetate. However, the relative low conversion rate severely limits its practical application. This study investigated the impact of different hydrogen evolution rates on the conversion rate of CO2 to acetate in the MES system. Three potentials (-0.8 V, -0.9 V and -1.0 V) corresponding to various hydrogen evolution rates were set and analyzed, revealing an optimal hydrogen evolution rate, yielding a maximum acetate formation rate of 1410.9 mg/L and 73.5 % coulomb efficiency. The electrochemical findings revealed that an optimal hydrogen evolution rate facilitated the formation of an electroactive biofilm. The microbial community of the cathode biofilm highlighted key genera, including Clostridium and Acetobacterium, which played essential roles in electrosynthesis within the MES system. Notably, a low hydrogen evolution rate failed to provide sufficient energy for the electrochemical reduction of CO2 to acetate, while a high rate led to cathode alkalinization, impeding the reaction and causing significant energy wastage. Therefore, maintaining an appropriate hydrogen evolution rate is crucial for the development of mature electroactive biofilms and achieving optimal performance in the MES system.

Riboflavin-loaded carbon cloth aids the anaerobic digestion of cow dung by promoting direct interspecies electron transfer.

Cow dung generates globally due to increased beef and milk consumption, but its treatment efficiency remains low. Previous studies have shown that riboflavin-loaded conductive materials can improve anaerobic digestion through enhance direct interspecies electron transfer (DIET). However, its effect on the practical anaerobic digestion of cow dung remained unclear. In this study, carbon cloth loaded with riboflavin (carbon cloth-riboflavin) was added into an anaerobic digester treating cow dung. The carbon cloth-riboflavin reactor showed a better performance than other two reactors. The metagenomic analysis revealed that Methanothrix on the surface of the carbon cloth predominantly utilized the CO2 reduction for methane production, further enhanced after riboflavin addition, while Methanothrix in bulk sludge were using the acetate decarboxylation pathway. Furthermore, the carbon cloth-riboflavin enriched various major methanogenic pathways and activated a large number of enzymes associated with DIET. Riboflavin's presence altered the microbial communities and the abundance of functional genes relate to DIET, ultimately leading to a better performance of anaerobic digestion for cow dung.

Granular activated carbon enhances volatile fatty acid production in the anaerobic fermentation of garden wastes.

Garden waste, one type of lignocellulosic biomass, holds significant potential for the production of volatile fatty acids (VFAs) through anaerobic fermentation. However, the hydrolysis efficiency of garden waste is limited by the inherent recalcitrance, which further influences VFA production. Granular activated carbon (GAC) could promote hydrolysis and acidogenesis efficiency during anaerobic fermentation. This study developed a strategy to use GAC to enhance the anaerobic fermentation of garden waste without any complex pretreatments and extra enzymes. The results showed that GAC addition could improve VFA production, especially acetate, and reach the maximum total VFA yield of 191.55 mg/g VSadded, which increased by 27.35% compared to the control group. The highest VFA/sCOD value of 70.01% was attained in the GAC-amended group, whereas the control group only reached 49.35%, indicating a better hydrolysis and acidogenesis capacity attributed to the addition of GAC. Microbial community results revealed that GAC addition promoted the enrichment of Caproiciproducens and Clostridium, which are crucial for anaerobic VFA production. In addition, only the GAC-amended group showed the presence of Sphaerochaeta and Oscillibacter genera, which are associated with electron transfer processes. Metagenomics analysis indicated that GAC addition improved the abundance of glycoside hydrolases (GHs) and key functional enzymes related to hydrolysis and acidogenesis. Furthermore, the assessment of major genera influencing functional genes in both groups indicated that Sphaerochaeta, Clostridium, and Caproicibacter were the primary contributors to upregulated genes. These findings underscored the significance of employing GAC to enhance the anaerobic fermentation of garden waste, offering a promising approach for sustainable biomass conversion and VFA production.

Recent progress of self-immobilizing and self-precipitating molecular fluorescent probes for higher-spatial-resolution imaging.

Flourished in the past two decades, fluorescent probe technology provides researchers with accurate and efficient tools for in situ imaging of biomarkers in living cells and tissues and may play a significant role in clinical diagnosis and treatment such as biomarker detection, fluorescence imaging-guided surgery, and photothermal/photodynamic therapy. In situ imaging of biomarkers depends on the spatial resolution of molecular probes. Nevertheless, the majority of currently available molecular fluorescent probes suffer from the drawback of diffusing from the target region. This leads to a rapid attenuation of the fluorescent signal over time and a reduction in spatial resolution. Consequently, the diffused fluorescent signal cannot accurately reflect the in situ information of the target. Self-immobilizing and self-precipitating molecular fluorescent probes can be used to overcome this problem. These probes ensure that the fluorescent signal remains at the location where the signal is generated for a long time. In this review, we introduce the development history of the two types of probes and classify them in detail according to different design strategies. In addition, we compare their advantages and disadvantages, summarize some representative studies conducted in recent years, and propose prospects for this field.

The importance of and difficulties involved in creating molecular probes for a carbon monoxide gasotransmitter.

As one of the triumvirate of recognized gasotransmitter molecules, namely NO, H2S, and CO, the physiological effects of CO and its potential as a biomarker have been widely investigated, garnering particular attention due to its reported hypotensive, anti-inflammatory, and cytoprotective properties, making it a promising therapeutic agent. However, the development of CO molecular probes has remained relatively stagnant in comparison with the fluorescent probes for NO and H2S, owing to its inert molecular state under physiological conditions. In this review, starting from elucidating the definition and significance of CO as a gasotransmitter, the imperative for the advancement of CO probes, especially fluorescent probes, is expounded. Subsequently, the current state of development of CO probe methodologies is comprehensively reviewed, with an overview of the challenges and prospects in this burgeoning field of research.

Recent research progress in galactose-based fluorescent probes for detection of biomarkers of liver diseases.

The liver is the largest detoxification organ in the human body, with an array of functions that help support metabolism, immunity, digestion, and vitamin storage, among other functions, and maintains the health and stability of the internal environment. Liver injury causes the concentration fluctuation of related biomarkers, small molecules, and enzymes, and in turn, the structure and function of the liver are changed by those alterations. With the principles of early detection, early diagnosis, and early treatment, it is crucial to design and synthesise a tool for detecting related biomarkers during liver damage and lesion, among which fluorescent probes have attracted attention in recent years. In the course of liver diseases, the asialoglycoprotein receptors (ASGPR) are overexpressed on the hepatoma cells, which can specifically recognize the galactose variant. Several galactose-based fluorescent probes have been developed to target hepatocytes via specific receptor-mediated endocytosis and release fluorophores after reacting with specific small molecules and enzyme biomarkers. The change in fluorescence intensity reflects the level of substances, such as reactive oxygen species, reactive nitrogen species, reactive sulfur species, enzymes or metal ions, etc. The application of fluorescent probes in vivo can aid in monitoring the dynamic changes of endogenous and exogenous biomarkers. This Highlight provides an update on the progress, limitations, and prospects of galactose-based fluorescent probes applications in the early diagnosis of liver diseases.

Paper-Based SERS Sensing Platform Based on 3D Silver Dendrites and Molecularly Imprinted Identifier Sandwich Hybrid for Neonicotinoid Quantification.

Real-time monitoring of neonicotinoid pesticide residues is of great significance for food security and sustainable development of the ecological environment. Herein, a paper-based surface-enhanced Raman scattering (SERS) amplified approach was proposed by virtue of multilayered plasmonic coupling amplification. The unique plasmonic SERS multilayer was constructed using three-dimensional (3D) silver dendrite (SD)/electropolymerized molecular identifier (EMI)/silver nanoparticle (AgNP) sandwich hybrids with multiple hotspots and a strong electromagnetic field in nanogaps. Dendritelike 3D silver materials with remarkably high accessible surface areas and the lightning rod effect constituted the first-order enhancement of paper-based sensors. Molecular identifiers coated upon an SD layer as the interlayer were used for target capture and enrichment. Subsequently, AgNPs featuring rough surface and local plasma resonance decorated as the top layer formed the secondary enhancement of the amplification strategy. As the most brilliant part, dendritelike 3D silver coupled with AgNPs has established double Ag layers to accomplish a multistage enhancement of SERS signals based on the superposition of their electromagnetic fields. Owning to the distinctive design of the multiple coupling amplification strategy, the fabricated SERS paper chips demonstrated impressive specificity and ultrahigh sensitivity in the detection of imidacloprid (IMI), with a detection limit as low as 0.02811 ng mL-1. More importantly, the multiple SERS enhancement paper chip holds great potential for automated screening of a variety of contaminants.

Phenylboronic Acid-Dopamine Dynamic Covalent Bond Involved Dual-Responsive Polymeric Complex: Construction and Anticancer Investigation.

In cancer treatment, prolonging the retention time of therapeutic agents in tumor tissues is a key point in enhancing the therapeutic efficacy. However, drug delivery by intravenous injection is always subjected to a "CAPIR" cascade, including circulation, accumulation, penetration, internalization, and release. Intratumoral administration has gradually emerged as an ideal alternative approach for nanomedicine because of its independence of blood constituents and minimal systemic toxicities. In this contribution, based on the dynamically reversible interaction between boronic acid (BA) and dopamine (DA), a thermo- and pH-responsive polymeric complex is rationally obtained by facile mixing of phenylboronic acid (PBA)- and tetraphenylethene (TPE)-modified poly(N-isopropylacrylamide)-b-poly(phenyl isocyanide)s block copolymers, PNIPAM-b-P(PBAPI-co-TPEPI), and tetra(ethylene glycol) methyl ether acrylate (OEGA)- and DA-containing hydrophilic P(DA-co-OEGA) copolymers. The resultant complex exhibited temperature- and pH-dependent size change as well as sustained nile red (NR) release profiles in a mimic tumor environment. Moreover, thanks to the opposite optical behavior of TPE and NR molecules, the complex could be served as a fluorescence ratiometric cell imaging agent, avoiding the interference of background fluorescence and improving correlated resolution. After encapsulation of camptothecin (anticancer drug), the efficient killing on HeLa cells was achieved in vitro, and the structural integrity of the complex endowed its extended retention time in tumor tissues. Considering these advantages, the reversible covalent interaction between PBA and diols can be used as an efficient driving force to form dynamic drug-delivery vectors, which are promising to be an effective nanoplatform for injectable medical treatments.

Positively charged helical chain-modified stimuli-responsive nanoassembly capable of targeted drug delivery and photoacoustic imaging-guided chemo-photothermal synergistic therapy.

In cancer treatment, surface modification by penetrating peptides and size control have been exploited as the two main strategies to tackle the problems of deep tumor penetration and cell internalization for nanocarriers. Polymeric nanocarriers with small size are beneficial for deep tumor penetration; however, they always undergo rapid clearance during body circulation and have low tumor accumulation efficiency. To solve this dilemma, a tumor-targeted size-switchable CPT/IR780@H30-PCL-PPI(L-)/PEI(-COOH/FA) nanoassembly with a "pomegranate" construction was designed in this study. Initially, it possessed a large size and negative charge to meet the long blood circulation time but rapidly disassembled into small-sized guanidinium and helical chain-modified unimolecular micelle-based nanocarriers, CPT/IR780@H30-PCL-PPI(L-/ + ), at tumor sites due to the tumor microenvironment-induced charge reversal. The CPT/IR780@H30-PCL-PPI(L-/+) assembly could efficiently expand the penetration depth and accelerate cell internalization due to the guanidinium group-modified helical chains, which exhibited a similar structure to that of the cell penetrating peptides. In addition, the nanoassembly exhibited strong photothermal conversion and acoustic generation efficiency. Moreover, the generated heat significantly improved the drug release, thus realizing functional cooperativity and adaptability. This proof of concept can be supposed to be a significant progress in the design and preparation of tumor microenvironment-responsive drug delivery systems and their use for photoacoustic imaging-assisted chemo-photothermal synergistic therapy.

Apoptosis of CD19+ chimeric antigen receptor T cells after treatment with chemotherapeutic agents.

The use of chemotherapeutic agents prior to treatment with infusion of cluster of differentiation (CD)19-chimeric antigen receptor (CAR)­T cells is important for the efficacy of clinical therapies against hematological malignancies. However, the effect of chemotherapeutic agents on CD19­CAR­T cells and the associated underlying mechanisms remain unknown. The first aim of the present study was to determine the effect of chemotherapeutic agents on CAR­T cells using the in vitro Cell Counting kit 8 assay. The second aim was to evaluate the abilities of fludarabine (FDR) and mafosfamide (MFA; a metabolite of cyclophosphamide) to induce apoptosis of CD19­CAR­T cells via the use of Annexin V/propidium iodide double staining. In addition, a JC­1 fluorescent probe was used to detect alterations in cell membrane potential, and flow cytometry analysis was used to measure concentrations of caspase­3/7 to identify apoptotic pathways of CD19­CAR­T cells. The data of the present study suggested that FDR and MFA inhibit the activities of CD19­CAR­T cells. Alterations to the mitochondrial membrane potential and an increase in the concentration of caspase­3/7 indicated early apoptosis of FDR­ and MFA­treated CD19­CAR­T cells. The present study laid a theoretical foundation for the development of programs for clinical treatment.

Oncogenic role of long noncoding RNA AF118081 in anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide-transformed 16HBE cells.

Lung cancer is the leading cause of cancer deaths and remains an important public health problem worldwide. Long noncoding RNAs (lncRNAs) are newly identified regulators of tumorigenesis and tumor progression. However, the role of lncRNAs in lung cancer induced by environmental carcinogens remains largely unknown. In this study, an lncRNA microarray was used to compare the expression profiles of malignantly transformed 16HBE cells (16HBE-T) induced with anti-benzo[a]pyrene-trans-7,8-diol-9,10-epoxide (anti-BPDE) and normal 16HBE cells (16HBE-N). Using quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), lncRNA AF118081 was identified as the most significantly overexpressed lncRNA in 16HBE-T cells, lung cancer cells, and patient samples. Cell proliferation, colony formation, apoptosis, migration, and invasion were assayed in 16HBE-T cells following the knockdown of lncRNA AF118081 with small interfering RNA. AF118081 knockdown inhibited cell growth and tumor invasion. An in vivo (nude mouse) model was then used to assay tumor growth, and the downregulation of AF118081 clearly suppressed tumor growth, consistent with the results of the in vitro assays. Together, these findings identify a new oncogenic lncRNA, lncRNA AF118081, in malignantly transformed 16HBE cells. This enhances our understanding of lncRNAs as important regulatory elements in chemical carcinogenesis and potential targets of lung cancer therapies.

Stimulation of bioluminescence in Noctiluca sp. using controlled temperature changes.

Bioluminescence induced by multifarious stimuli has long been observed and is remains under investigation because of its great complexity. In particular, the exact mechanism underlying bioluminescence is not yet fully understood. This work presents a new experimental method for studying Noctiluca sp. bioluminescence under temperature change stimulation. It is a study of Noctiluca sp. bioluminescence using controlled temperature changes in a tank. A characteristic of this experiment is the large volume of water used (1 m(3) in a tank of 2 × 1 × 1 m). Temperature changes were controlled by two methods. In the first, a flask filled with hot water was introduced into the tank and in the second, a water heater was used in the tank. Temperature changes were recorded using sensors. Noctiluca sp. bioluminescence was recorded using a Canon 5D Mark II and this allowed the characteristics of Noctiluca sp. bioluminescence under temperature change stimulation to be monitored.

Remarkable dependence of electrochemical performance of SrCo0.8Fe0.2O(3-δ) on A-site nonstoichiometry.

SrCo(0.8)Fe(0.2)O(3-δ) is a controversial material whether it is used as an oxygen permeable membrane or as a cathode of solid oxide fuel cells. In this paper, carefully synthesized powders of perovskite-type Sr(x)Co(0.8)Fe(0.2)O(3-δ) (x = 0.80-1.20) oxides are utilized to investigate the effect of A-site nonstoichiometry on their electrochemical performance. The electrical conductivity, sintering property and stability in ambient air of Sr(x)Co(0.8)Fe(0.2)O(3-δ) are critically dependent on the A-site nonstoichiometry. Sr(1.00)Co(0.8)Fe(0.2)O(3-δ) has a single-phase cubic perovskite structure, but a cobalt-iron oxide impurity appears in A-site cation deficient samples and Sr(3)(Co, Fe)(2)O(7-δ) appears when there is an A-site cation excess. It was found that the presence of the cobalt-iron oxide improves the electrochemical performance. However, Sr(3)(Co, Fe)(2)O(7-δ) has a significant negative influence on the electrochemical activity for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The peak power densities with a single-layer Sr(1.00)Co(0.8)Fe(0.2)O(3-δ) cathode are 275, 475, 749 and 962 mW cm(-2) at 550, 600, 650 and 700 °C, respectively, values which are slightly lower than those for Sr(0.95)Co(0.8)Fe(0.2)O(3-δ) (e.g. 1025 mW cm(-2) at 700 °C) but much higher than those for Sr(1.05)Co(0.8)Fe(0.2)O(3-δ) (e.g. only 371 mW cm(-2) at 700 °C). This remarkable dependence of electrochemical performance of the Sr(x)Co(0.8)Fe(0.2)O(3-δ) cathode on the A-site nonstoichiometry reveals that lower values of electrochemical activity reported in the literature may be induced by an A-site cation excess. Therefore, to obtain a high performance of Sr(x)Co(0.8)Fe(0.2)O(3-δ) cathode for IT-SOFCs, an A-site cation excess must be avoided.

Novel dual-phase membranes for CO2 capture via an oxyfuel route.

Ceria-based dual-phase membranes showing high oxygen permeation fluxes and stability under a CO(2) environment are promising materials for CO(2) capture via an oxyfuel route. The high oxygen permeation fluxes compared with other dual-phase membranes are derived from the mixed conducting properties of the perovskite oxides used in the dual-phase membranes.

The role of miR-506 in transformed 16HBE cells induced by anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide.

Growing evidence indicates that the alteration of microRNA (miRNA) expression in tumors that is induced by chemical carcinogens plays an important role in tumor development and progression. However, the mechanism underlying miRNA involvement in lung carcinogenesis induced by anti-benzo[a]pyrene-trans-7,8-dihydrodiol-9,10-epoxide (anti-BPDE) remains unclear. In our study, we used the malignant transformation of human bronchial epithelial cells (16HBE-T) induced by anti-BPDE to explore the mechanisms of human lung carcinogenesis. We found that expression of miR-506 was reduced in 16HBE-T transformed malignant human bronchial epithelial cells compared with 16HBE normal human bronchial epithelial cells. Restoration of miR-506 in 16HBE-T cells led to a decrease in cell proliferation, G0/G1 phase cell cycle arrest, as well as significantly suppressed anchorage-dependent growth in vitro and tumor growth inhibition in a nude mouse xenograft model. In addition, we provided novel evidence regarding the role miR-506 potentially plays in negatively regulating the protein and mRNA expression level of N-Ras in cancer cells. Together, these findings revealed that miR-506 acts as an anti-oncogenic miRNA (anti-oncomir) in malignantly transformed cells. The identification of tumor suppressive miRNAs could provide new insight into the molecular mechanisms of chemical carcinogenesis.

[Effect of miR-542-3p on carcinogenesis induced by anti-benzo(a) pyrene-7,8-diol-9,10-epoxide].

OBJECTIVE: To explore the effect of miR-542-3p in malignant transformation of human bronchial epithelial cells (16HBE) induced by anti-benzo(a)pyrene-7,8-diol-9,10-epoxide (anti-BPDE). METHODS: The relative expression level of mature miR-542-3p in transformed cells (16HBE-T) and untransformed control cells (16HBE-N) was measured by real-time quantitative polymerase chain reaction (qRT-PCR). miRNA mimic was transiently transfected into 16HBE-T to change the expression level of miR-542-3p, and then the influenced changes of cell proliferation, cell cycle, apoptosis, and soft agar colony formation rate and the migration of transfected cells were analyzed. RESULTS: Before transfection, the expression level of mature miR-542-3p in 16HBE-T was lower (39.08 ± 6.95)% than it in 16HBE-N (t = 15.18, P < 0.05). In comparison with the 16HBE-T group, the expression level of miR-542-3p in miR-542-3p mimic-transfected group was (5.23 ± 0.55) fold (t = 17.37, P < 0.05) after transfection. Cell proliferation of mimic-transfected group was decreased to (62.06 ± 5.61)% (t = -17.28, P < 0.05), percentage of cells in G(0)/G(1) phase up to (74.76 ± 4.86)% (t = 4.53, P < 0.05), rate of colony formation degrade to (5.87 ± 0.67)% (t = -6.66, P < 0.05), coverage areas ratio decreased to (0.31 ± 0.08) (t = -6.78, P < 0.05). There was no change with apoptosis. CONCLUSION: Our studies showed that miR-542-3p played the role as a tumor suppressor, which led to a significant decrease in the proliferation capacity and degree of malignancy. These findings suggest aberrantly down-regulated miR-542-3p may be one critical factor that contributes to malignant transformation of 16HBE induced by anti-BPDE.

Novel Mn1.5Co1.5O4 spinel cathodes for intermediate temperature solid oxide fuel cells.

Mn(1.5)Co(1.5)O(4) spinel oxide as a cathode or one component of a composite cathode presents no visible reaction with an Y(2)O(3)-stabilized ZrO(2) electrolyte. The low electrode polarization resistances and good performance compared with traditional Sr-doped LaMnO(3)-YSZ composite cathodes imply promising application for the next generation of intermediate-temperature solid oxide fuel cells.