Phthalates contamination in sediments: A review of sources, influencing factors, benthic toxicity, and removal strategies.

Sediments provide habitat and food for benthos, and phthalates (PAEs) have been detected in numerous river and marine sediments as a widely used plastic additive. PAEs in sediments is not only toxic to benthos, but also poses a threat to pelagic fish and human health through the food chain, so it is essential to comprehensively assess the contamination of sediments with PAEs. This paper presents a critical evaluation of PAEs in sediments, which is embodied in the analysis of the sources of PAEs in sediments from multiple perspectives. Biological production is indispensable, while artificial synthesis is the most dominant, thus the focus was on analyzing the industrial and commercial sources of synthetic PAEs. In addition, since the content of PAEs in sediments varies, some factors affecting the content of PAEs in sediments are summarized, such as the properties of PAEs, the properties of plastics, and environmental factors (sediments properties and hydrodynamic conditions). As endocrine disruptors, PAEs can produce toxicity to its direct contacts. Therefore, the effects of PAEs on benthos immunity, endocrinology, reproduction, development, and metabolism were comprehensively analyzed. In addition, we found that reciprocal inhibition and activation of the systems lead to genotoxicity and apoptosis. Finally, the paper discusses the feasible measures to control PAEs in wastewater and leachate from the perspective of source control, and summarizes the in-situ treatment measures for PAEs contamination in sediments. This paper provides a comprehensive review of PAEs contamination in sediments, toxic effects and removal strategies, and provides an important reference for reducing the contamination and toxicity of PAEs to benthos.

Tissue-specific toxic effects of nano-copper on zebrafish.

Understanding the behavior and potential toxicity of copper nanoparticles (nano-Cu) in the aquatic environment is a primary way to assess their environmental risks. In this study, RNA-seq was performed on three different tissues (gills, intestines, and muscles) of zebrafish exposed to nano-Cu, to explore the potential toxic mechanism of nano-Cu on zebrafish. The results indicated that the toxic mechanism of nano-Cu on zebrafish was tissue-specific. Nano-Cu enables the CB1 receptor of the presynaptic membrane of gill cells to affect short-term synaptic plasticity or long-term synaptic changes (ECB-LTD) through DSI and DSE, causing dysfunction of intercellular signal transmission. Imbalance of de novo synthesis of UMP in intestinal cells and its transformation to UDP, UTP, uridine, and uracil, resulted in many functions involved in the pyrimidine metabolic pathway being blocked. Meanwhile, the toxicity of nano-Cu caused abnormal expression of RAD51 gene in muscle cells, which affects the repair of damaged DNA through Fanconi anemia and homologous recombination pathway, thus causing cell cycle disorder. These results provide insights for us to better understand the differences in toxicity of nano-Cu on zebrafish tissues and are helpful for a comprehensive assessment of nano-Cu's effects on aquatic organisms.

Doping Engineering of Conductive Polymers and Their Application in Physical Sensors for Healthcare Monitoring.

Physical sensors have emerged as a promising technology for real-time healthcare monitoring, which tracks various physical signals from the human body. Accurate acquisition of these physical signals from biological tissue requires excellent electrical conductivity and long-term durability of the sensors under complex mechanical deformation. Conductive polymers, combining the advantages of conventional polymers and organic conductors, are considered ideal conductive materials for healthcare physical sensors due to their intrinsic conductive network, tunable mechanical properties, and easy processing. Doping engineering has been proposed as an effective approach to enhance the sensitivity, lower the detection limit, and widen the operational range of sensors based on conductive polymers. This approach enables the introduction of dopants into conductive polymers to adjust and control the microstructure and energy levels of conductive polymers, thereby optimizing their mechanical and conductivity properties. This review article provides a comprehensive overview of doping engineering methods to improve the physical properties of conductive polymers and highlights their applications in the field of healthcare physical sensors, including temperature sensors, strain sensors, stress sensors, and electrophysiological sensing. Additionally, the challenges and opportunities associated with conductive polymer-based physical sensors in healthcare monitoring are discussed.

A critical review on BDE-209: Source, distribution, influencing factors, toxicity, and degradation.

As the most widely used polybrominated diphenyl ether, BDE-209 is commonly used in polymer-based commercial and household products. Due to its unique physicochemical properties, BDE-209 is ubiquitous in a variety of environmental compartments and can be exposed to organisms in various ways and cause toxic effects. The present review outlines the current state of knowledge on the occurrence of BDE-209 in the environment, influencing factors, toxicity, and degradation. BDE-209 has been detected in various environmental matrices including air, soil, water, and sediment. Additionally, environmental factors such as organic matter, total suspended particulate, hydrodynamic, wind, and temperature affecting BDE-209 are specifically discussed. Toxicity studies suggest BDE-209 may cause systemic toxic effects on living organisms, reproductive toxicity, embryo-fetal toxicity, genetic toxicity, endocrine toxicity, neurotoxicity, immunotoxicity, and developmental toxicity, or even be carcinogenic. BDE-209 has toxic effects on organisms mainly through epigenetic regulation and induction of oxidative stress. Evidence regarding the degradation of BDE-209, including biodegradation, photodegradation, Fenton degradation, zero-valent iron degradation, chemical oxidative degradation, and microwave radiation degradation is summarized. This review may contribute to assessing the environmental risks of BDE-209 to help develop rational management plans.

Hydrogel-Based Bioelectronics and Their Applications in Health Monitoring.

Flexible bioelectronics exhibit promising potential for health monitoring, owing to their soft and stretchable nature. However, the simultaneous improvement of mechanical properties, biocompatibility, and signal-to-noise ratio of these devices for health monitoring poses a significant challenge. Hydrogels, with their loose three-dimensional network structure that encapsulates massive amounts of water, are a potential solution. Through the incorporation of polymers or conductive fillers into the hydrogel and special preparation methods, hydrogels can achieve a unification of excellent properties such as mechanical properties, self-healing, adhesion, and biocompatibility, making them a hot material for health monitoring bioelectronics. Currently, hydrogel-based bioelectronics can be used to fabricate flexible bioelectronics for motion, bioelectric, and biomolecular acquisition for human health monitoring and further clinical applications. This review focuses on materials, devices, and applications for hydrogel-based bioelectronics. The main material properties and research advances of hydrogels for health monitoring bioelectronics are summarized firstly. Then, we provide a focused discussion on hydrogel-based bioelectronics for health monitoring, which are classified as skin-attachable, implantable, or semi-implantable depending on the depth of penetration and the location of the device. Finally, future challenges and opportunities of hydrogel-based bioelectronics for health monitoring are envisioned.

Recent progress on performances and mechanisms of carbon dots for gas sensing.

Carbon dots (CDs), as an attractive zero-dimensional carbon nanomaterial with unique photoluminescent merits, have recently exhibited significant application potential in gas sensing as a result of their excellent optical/electronic characteristics, high chemical/thermal stability, and tunable surface states. CDs exhibit strong light absorption in the ultraviolet range and tunable photoluminescence characteristics in the visible range, which makes CDs an effective tool for optical sensing applications. Optical gas sensor based on CDs have been investigated, which generally responds to the target gas by corresponding changes in optical absorption or fluorescence. Moreover, electrical gas sensor and quartz crystal microbalance sensor whose sensing layer involves CDs have also been designed. Electrical gas sensor exhibits an increase or a decrease in electrical current, capacitance, or conductance once exposed to the target gas. Quartz crystal microbalance sensor responds to the target gas with a frequency shift. CDs greatly promote the absorption of the target gas and improve the sensitivity of both sensors. In this review, we aim to summarize different types of gas sensors involving CDs, and sensing performances of these sensors for monitoring diverse gases or vapors, as well as the mechanisms of CDs in different types of sensors. Moreover, this review provides the prospect of the potential development of CDs based gas sensors.

Impacts of the COVID-19 pandemic on fish trade and the coping strategies: An initial assessment from China's perspective.

The outbreak of the COVID-19 pandemic in 2020 has posed unprecedented challenges for fish trade worldwide. This study examines these challenges through an observation of China's fish import and export activities and a qualitative study on evolving policies in the first nine months of 2020. The results indicate that control measures responding to uncertainty regarding the source of the disease and transmission path, the pressing need for restriction of the movement of people and goods, and fear of a second wave of outbreaks have substantially disrupted fish trade. To meet these challenges, certain coping measures are adopted to offset negative effects in the short term. These measures indicate the government's pivotal role in stabilizing the supply chain and striking a balance between control requirements and efficiency required in trading activities, as well as the importance to find alternative markets to mitigate risks brought by the delayed supply and the plummeting consumption market. It concludes with some suggestions on improving international cooperation and domestic regulation for building resilience in long run.

Ultralong lifetime and efficient room temperature phosphorescent carbon dots through multi-confinement structure design.

Room temperature phosphorescence materials have inspired extensive attention owing to their great potential in optical applications. However, it is hard to achieve a room temperature phosphorescence material with simultaneous long lifetime and high phosphorescence quantum efficiency. Herein, multi-confined carbon dots were designed and fabricated, enabling room temperature phosphorescence material with simultaneous ultralong lifetime, high phosphorescence quantum efficiency, and excellent stability. The multi-confinement by a highly rigid network, stable covalent bonding, and 3D spatial restriction efficiently rigidified the triplet excited states of carbon dots from non-radiative deactivation. The as-designed multi-confined carbon dots exhibit ultralong lifetime of 5.72 s, phosphorescence quantum efficiency of 26.36%, and exceptional stability against strong oxidants, acids and bases, as well as polar solvents. This work provides design principles and a universal strategy to construct metal-free room temperature phosphorescence materials with ultralong lifetime, high phosphorescence quantum efficiency, and high stability for promising applications, especially under harsh conditions.

Enhancement of Fluorescence Emission for Tricolor Quantum Dots Assembled in Polysiloxane toward Solar Spectrum-Simulated White Light-Emitting Devices.

Commercial white light-emitting diodes (LEDs) have the undesirable characteristics of blue-rich emission and low color rendering index (CRI), while the constituent quantum dots (QDs) suffer from aggregation-induced fluorescence quenching and poor stability. Herein, a strategy is developed to assemble tricolor QDs into a polysiloxane matrix using a polymer-mediated hybrid approach whereby the hybrid composite exhibits a significant enhancement of aggregation-dispersed emission, outstanding photostability, high thermal stability, and outstanding fluorescence recovery. Using the as-prepared hybrid fluorescent materials, the fabricated LEDs exhibit solar spectrum-simulated emission with adjustable Commission Internationale de L'Eclairage coordinates, correlated color temperature, and a recorded CRI of 97. Furthermore, they present no ultraviolet emission and weak blue emission, thus indicating an ideal healthy and high-CRI white LED lighting source.

Synthesis of dual-emissive carbon dots with a unique solvatochromism phenomenon.

Carbon dots as an emerging photoluminescent material has attracted growing attention. Hence, there is a highly urgent to develop kinds of multicolor emission carbon dots materials. Here, we report a new kind of dual-emissive carbon dots which display two emission band located at 457 and 643 nm (blue and red) in alcohols solvent, respectively. In particular, the red emission band of carbon dots independent of the excitation wavelength can be manipulated by changing the polarity of the solvent, which is called solvatochromic phenomenon. It is incredibly rare for bare carbon dots to have both dual-emission and solvatochromic phenomenon at the same time. The temperature-dependent emission spectra of synthesized carbon dots have been measured to go insight into the hydrogen bond interaction, and the aggregation in microscale is observed by transmission electron microscopy. Results indicates that the special dual-emission and solvatochromic phenomenon stem from partially nanoparticle agglomerates which caused by intermolecular hydrogen bond (between solvents and carbon dots). Benefiting from the special optical characteristics, the applications of ratiometric detecting water in ethanol was carried out.

Synthesis of Silicon Quantum Dots with Highly Efficient Full-Band UV Absorption and Their Applications in Antiyellowing and Resistance of Photodegradation.

UV absorbers are very effective in the fields of antiyellowing, resistance of photocatalytic degradation, and sunscreen cosmetics. However, commercialized UV absorbers have the drawbacks of toxicity, low absorption efficiency, transparency, etc. Here, we report for the first time silicon quantum dots as full-band UV absorbers. The NH-refunctionalized silicon quantum dots with high-performance UV absorption were successfully synthesized under the synergistic effect of sodium citrate and ethanediamine, and the (NH, OH)-functionalized silicon quantum dots (SiQDs) with full-band UV absorption can be achieved by reregulating -NH2 and -OH groups on the surface. The as-prepared (NH, OH)-functionalized SiQDs exhibited good stability and underwent treatment of varying pH and temperature. Furthermore, experimental results demonstrated that compared to commercial water-soluble organic UV absorbers, the (NH, OH)-functionalized SiQDs showed better antiyellowing performance for polyurethane and resistance of photocatalytic degradation for rhodamine B, and presented huge application potential in sunscreen cosmetics. Finally, the UV absorption mechanism of SiQDs was explained to be mainly related to Γ â†’ Γ direct band gap transition, which absorb UV light and release it as thermal radiation.

Assembly of shell/core CDs@CaF2 nanocomposites to endow polymers with multifunctional properties.

The shell/core structure of CDs@CaF2 nanocomposites (CCNCs) were prepared by assembling fluorescent carbon dots (CDs) inside the inorganic CaF2 substrates using co-precipitation interaction. CDs endow CaF2 with properties of good UV-absorbing behavior and efficient blue light emission instead of rare-earth such as Eu that is expensive and susceptible to polluting the environment during the mining process. Due to the nanometer size and surface effect of nano CaF2, and the approximate refractive index between CaF2 and polyethylene (PE), CCNC/PE film exhibits better elongation at the break than pure PE film while maintaining high transparency and visible light transmittance. Simultaneously, the CCNC/PE film was experimentally demonstrated to have outstanding performance of anti-UV and blue light conversion, which shows that CCNCs can be a novel and promising multifunctional additive applied in polymers especially for greenhouse film.

Integration of cell-free protein synthesis and purification in one microfluidic chip for on-demand production of recombinant protein.

Recombinant proteins have shown several benefits compared with their non-recombinant counterparts in protein therapeutics. However, there are still some problems with the storage and distribution of recombinant proteins, owing to their temperature sensitivity. Microfluidic chips can integrate different functional modules into a single device because of the advantages of integration and miniaturization, which have the special potential to synthesize drugs when and where they are needed most. Here, we integrated cell-free protein synthesis and purification into a microfluidic chip for the production of recombinant protein. The chip consisted of a main channel and a branch channel. The main channel included two pinches, which were filled with template DNA-modified agarose microbeads and nickel ion-modified agarose beads as the cell-free protein synthesis unit and protein purification unit, respectively. The reaction mixture for protein synthesis was introduced into the main channel and first passed through the protein synthesis unit where the target protein was synthesized; next, the reaction mixture passed through the protein purification unit where the target protein was captured; and, finally, pure protein was collected at the outlet when washing buffer and eluting buffer were sequentially introduced into the branch channel. Enhanced green fluorescent protein (EGFP) was used as the model to investigate the performance of our chip. One chip could produce 70 µl of EGFP solution (144.3 µg/ml, 10.1 µg) per batch, and another round of protein synthesis and purification could be performed after replacing or regenerating nickel ion-modified agarose beads. It should be possible to produce other recombinant proteins on demand with this chip by simply replacing the template DNA.

A light-up fluorescence assay for tumor cell detection based on bifunctional split aptamers.

Light-up aptamers have attracted growing attention due to their advantages of being label-free and having low fluorescence background. In this work, we developed a light-up fluorescence assay for label-free detection of tumor cells based on a bifunctional split aptamer (BFSA) that contained two DNA strands (BFSA-a and BFSA-b). BFSA-a and BFSA-b were constructed by combining aptamers ZY11 and ThT.2-2, which could specifically bind to the tumor cell SMMC-7721 and activate the fluorescence of thioflavin T (ThT). A Helper strand was introduced to hybridize with BFSA-b, and then BFSA-a and BFSA-b were separated if the target cell was absent. Only when the target cell is present can BFSA-a approach and hybridize with BFSA-b due to the 'induced-fit effect', which made the Helper strand dissociate. Then ThT bound to BFSA and the fluorescence of ThT was activated. The results indicated that this fluorescence assay had a good linear response to the target cells in the range of 250-20 000 cells in 100 µL binding buffer; the lowest cell number actually detected was 125 cells in 100 µL buffer. This assay also displayed excellent selectivity and was successfully applied to detect target cells in 20% human serum samples. The design of bifunctional split aptamers realized no-washing, label-free, low-cost, one-step detection of tumor cells, which could generate detectable fluorescence signals just by mixing nucleic acid aptamers and fluorescent reporter molecules with target cells. Such a design of aptamer probes also has the potential to construct stimuli-responsive controlled drug delivery systems.

Enhanced Imaging of Specific Cell-Surface Glycosylation Based on Multi-FRET.

Cell-surface glycosylation contains abundant biological information that reflects cell physiological state, and it is of great value to image cell-surface glycosylation to elucidate its functions. Here we present a hybridization chain reaction (HCR)-based multifluorescence resonance energy transfer (multi-FRET) method for specific imaging of cell-surface glycosylation. By installing donors through metabolic glycan labeling and acceptors through aptamer-tethered nanoassemblies on the same glycoconjugate, intramolecular multi-FRET occurs due to near donor-acceptor distance. Benefiting from amplified effect and spatial flexibility of the HCR nanoassemblies, enhanced multi-FRET imaging of specific cell-surface glycosylation can be obtained. With this HCR-based multi-FRET method, we achieved obvious contrast in imaging of protein-specific GalNAcylation on 7211 cell surfaces. In addition, we demonstrated the general applicability of this method by visualizing the protein-specific sialylation on CEM cell surfaces. Furthermore, the expression changes of CEM cell-surface protein-specific sialylation under drug treatment was accurately monitored. This developed imaging method may provide a powerful tool in researching glycosylation functions, discovering biomarkers, and screening drugs.

High Signal-to-Background Ratio Detection of Cancer Cells with Activatable Strategy Based on Target-Induced Self-Assembly of Split Aptamers.

Highly sensitive detection of cancer cells with high signal-to-background ratio (SBR) is still urgently needed. Here, a self-assembling activatable probe (SAAP) based on split aptamers was developed to meet this purpose. The SAAP is formed with quenched fluorescence; only when target cells are present would the split aptamers self-assemble together and thus activate fluorescence by intramolecular and intermolecular fluorescence quenching strategies. As proof of concept, a split aptamer pair stemming from an intact aptamer, ZY11, developed by our lab was selected to construct SAAP. Owing to the design of self-assembly and activation strategy, the SBR of our approach could be raised to ∼40 and achieved a very low detection limit of seven target 7721 cells in 100 µL of binding buffer. Meanwhile, one-step detection of target cells was achieved within 15 min without any washing steps and pretreatment, which shows potential for point-of-care detection. Moreover, we succeeded in the specific recognition of target cells in 50% human serum and mixed cell samples, which indicated this strategy had great advantages in detection in complex biological samples. In addition, dual-signal detection was also successfully implemented, which may be helpful for accurate detection of target cells. Therefore, this rapid, facile, specific, and highly sensitive detection method for cancer cells may provide convenience in cancer research and medical diagnosis.