Heavy Metal Removal from Wastewater Using Poly(Gamma-Glutamic Acid)-Based Hydrogel.

The removal of toxic heavy metal ions from wastewater is of great significance in the protection of the environment and human health. Poly(gamma-glutamic acid) (PGA) is a non-toxic, biodegradable, and highly water-soluble polymer possessing carboxyl and imino functional groups. Herein, water-insoluble PGA-based hydrogels were prepared, characterized, and investigated as heavy metal adsorbents. The prepared hydrogels were recyclable and exhibited good adsorption effects on heavy metal ions including Cu2+, Cr6+, and Zn2+. The effects of adsorption parameters including temperature, solution pH, initial concentration of metal ions, and contact time on the adsorption capacity of the hydrogel for Cu2+ were investigated. The adsorption was a spontaneous and exothermic process. The process followed the pseudo-first-order kinetic model and Langmuir isotherm model, implying a physical and monolayer adsorption. The adsorption mechanisms investigation exhibited that Cu2+ adsorbed on the hydrogel via electrostatic interactions with anionic carboxylate groups of PGA in addition to the coordination interactions with the -NH groups. Importantly, the PGA hydrogel exhibited good reusability and the adsorption capability for Cu2+ remained high after five consecutive cycles. The properties of PGA hydrogel make it a potential candidate material for heavy metal ion removal in wastewater treatment.

Time-course transcriptome analysis discloses PFDMO2OA (C8 HFPO-TA)-induced developmental malformations and cardiovascular toxicities in zebrafish.

PFDMO2OA (C8 HFPO-TA), a novel substitute for perfluorooctanoic acid (PFOA), has been frequently detected in surface waters. However, information on its toxicity remains scarce. In the present study, zebrafish embryos were exposed to varying concentrations of PFDMO2OA, ranging from 80 to 800 mg/L, until 120 h post-fertilization (hpf) to explore its potential developmental toxicities. The LC50 value for mortality was 505.9 mg/L, comparable to that of PFOA (over 500 mg/L), suggesting a lack of safety of PFDMO2OA compared to PFOA. At 120 hpf, PFDMO2OA exposure led to various malformations in embryos, including uninflated swim bladder, yolk sac oedema, spinal deformation, and pigmentation changes, with pericardial oedema being prominent. Analysis using O-dianisidine stain indicated a decline in erythrocytes over time. Transcriptome analysis further revealed the cardiovascular toxicity caused by PFDMO2OA at the molecular level. Time-course differential analysis pointed to the apoptosis dependent on disrupted mitochondrial function as a significant contributor to erythrocyte disappearance, as confirmed by the TUNEL stain. Therefore, the present findings suggest that PFDMO2OA induces developmental malformations and cardiovascular toxicities in zebrafish embryos, demonstrating a toxic potency comparable to that of PFOA. The results further highlight the significance of evaluating the health risks associated with PFDMO2OA.

Comprehensive Characterization of Organic Light-Emitting Materials in Breast Milk by Target and Suspect Screening.

Organic light-emitting materials (OLEMs) are emerging contaminants in the environment and have been detected in various environment samples. However, limited information is available regarding their contamination within the human body. Here, we developed a novel QuEChERS (quick, easy, cheap, effective, rugged, and safe) method coupled with triple quadrupole/high-resolution mass spectrometry to determine OLEMs in breast milk samples, employing both target and suspect screening strategies. Our analysis uncovered the presence of seven out of the 39 targeted OLEMs in breast milk samples, comprising five liquid crystal monomers and two OLEMs commonly used in organic light-emitting diode displays. The cumulative concentrations of the seven OLEMs in each breast milk sample ranged from ND to 1.67 × 103 ng/g lipid weight, with a mean and median concentration of 78.76 and 0.71 ng/g lipid weight, respectively, which were higher compared to that of typical organic pollutants such as polychlorinated biphenyls and polybrominated diphenyl ethers. We calculated the estimated daily intake (EDI) rates of OLEMs for infants aged 0-12 months, and the mean EDI rates during lactation were estimated to range from 30.37 to 54.89 ng/kg bw/day. Employing a suspect screening approach, we additionally identified 66 potential OLEMs, and two of them, cholesteryl hydrogen phthalate and cholesteryl benzoate, were further confirmed using pure reference standards. These two substances belong to cholesteric liquid crystal materials and raise concerns about potential endocrine-disrupting effects, as indicated by in silico predictive models. Overall, our present study established a robust method for the identification of OLEMs in breast milk samples, shedding light on their presence in the human body. These findings indicate human exposure to OLEMs that should be further investigated, including their health risks.

An Injectable Magnesium-Based Cement Stimulated with NIR for Drug-Controlled Release and Osteogenic Potential.

Magnesium phosphate bone cement (MPC) has gained widespread usage in orthopedic implantation due to its fast-setting and high initial strength benefits. However, the simultaneous attainment of drug-controlled release and osteogenic potential in MPC remains a significant challenge. Herein, a strategy to create a smart injectable cement system using nanocontainers and chondroitin sulfate is proposed. It employs nanocontainers containing alendronate-loaded mesoporous silica nanoparticles, which are surface-modified with polypyrrole to control drug release in response to near-infrared (NIR) stimulation. The alendronate-incorporated cement (ACMPC) exhibits improved compressive strength (70.6 ± 5.9 MPa), prolonged setting time (913 s), and exceptional injectability (96.5% of injection rate and 242 s of injection time). It also shows the capability to prevent degradation, thus preserving mechanical properties. Under NIR irradiation, the cement shows good antibacterial properties due to the combined impact of hyperthermia, reactive oxygen species, and alendronate. Furthermore, the ACMPC (NIR) group displays good biocompatibility and osteogenesis capabilities, which also lead to an increase in alkaline phosphatase activity, extracellular matrix mineralization, and the upregulation of osteogenic genes. This research has significant implications for developing multifunctional biomaterials and clinical applications.

Transgenerational effects of extracts containing Microcystin-LR exposure on reproductive toxicity and offspring growth inhibition in a model organism zebrafish.

Cyanobacteria cell lysates release numerous toxic substances (e.g., cyanotoxins) into the water, posing a serious threat to human health and aquatic ecosystems. Microcystins (MCs) are among the most abundant cyanotoxins in the cell lysates, with microcystin-LR (MC-LR) being one of the most common and highly toxic congeners. In this study, zebrafish (Danio rerio) were exposed to different levels MC-LR that from extracts of Microcystis aeruginosa. Changes in the MC-LR accumulations, organ coefficients, and antioxidant enzyme activities in the zebrafish were analyzed. Transgenerational reproductive toxicity of MC-LR in the maternal and paternal generations was further investigated, as well as the influences of extracts containing MC-LR exposures of the F1 on the growth of zebrafish. The study found that high levels of MC-LR could be detected in the major organs of adult zebrafish, particularly in spleen. Notably, concentration of MC-LR in the spermary was significantly higher than that in the ovarium. MC-LR could induce oxidative damage by affecting the activities of catalase and superoxide dismutase. Inherited from F0, MC-LR led to impaired development in the F1 generation. Difference in offspring survival rates could be observed in the groups with different MC-LR levels of maternal and paternal exposures. This study reveals transgenerational effects of MC-LR on the reproductive toxicity and offspring growth inhibition to the aquatic organisms, which should be emphasized in the future ecological risk assessment.

Obesogenic potentials of environmental artificial sweeteners with disturbances on both lipid metabolism and neural responses.

Artificial sweeteners (ASs) entered the environments after application and emissions. Recent studies showed that some ASs had obesogenic risks. However, it remained unclear whether such risks are common and how they provoke such effects. Presently, the effects of 8 widely used ASs on lipid accumulation were measured in Caenorhabditis elegans. Potential mechanisms were explored with feeding and locomotion behavior, lipid metabolism and neural regulation. Results showed that acesulfame (ACE), aspartame (ASP), saccharin sodium (SOD), sucralose (SUC) and cyclamate (CYC) stimulated lipid accumulation at µg/L levels, showing obesogenic potentials. Behavior investigation showed that ACE, ASP, SOD, SUC and CYC biased more feeding in the energy intake aspect against the locomotion in the energy consumption one. Neotame (NEO), saccharin (SAC) and alitame (ALT) reduced the lipid accumulation without significant obesogenic potentials in the present study. However, all 8 ASs commonly disturbed enzymes (e.g., acetyl-CoA carboxylase) in lipogenesis and those (e.g., carnitine palmitoyl transferase) in lipolysis. In addition, ASs disturbed PPARγ (via expressions of nhr-49), TGF-ß/DAF-7 (daf-7) and SREBP (sbp-1) pathways. Moreover, they also interfered neurotransmitters including serotonin (5-HT), dopamine (DA) and acetylcholine (ACh), with influences in Gsα (e.g., via expressions of gsα-1, ser-7), glutamate (e.g., mgl-1), and cGMP-dependent signaling pathways (e.g., egl-4). In summary, environmental ASs commonly disturbed neural regulation connecting behavior and lipid metabolism, and 5 out of 8 showed clear obesogenic potentials. ENVIRONMENTAL IMPLICATION: Artificial sweeteners (ASs) are become emerging pollutants after wide application and continuous emission. Recent studies showed that some environmental ASs had obesogenic risks. The present study employed Caenorhabditis elegans to explore the influences of 8 commonly used ASs on lipid metabolisms and also the underlying mechanisms. Five out of 8 ASs stimulated lipid accumulation at µg/L levels, and they biased energy intake against energy consumption. The other three ASs reduced the lipid accumulation. ASs commonly disturbed lipogenesis and lipolysis via PPARγ, TGF-ß and SREBP pathways, and also influenced neurotransmitters with Gsα, glutamate and cGMP-dependent signaling pathways.

Bringing the emerging organophosphate flame retardants (eOPFRs) into view: A hidden ecological and human health threat.

The production and usage of organophosphate flame retardants (OPFRs) in textiles, plastics, and electronics have surged, with phosphorus-based flame retardants constituting over 30 % of the global consumption of flame retardants. Meanwhile, concerns regarding the potential hazards of OPFRs to ecosystems and human health including disruptions in the endocrine system, inhibition of reproduction, and manifestation of developmental defects have intensified. However, our comprehensive data analysis has unveiled a pronounced and critical knowledge gap, as at present, a majority of studies emphasize the attributes of traditional OPFRs, such as triphenyl phosphate (TPHP), while emerging OPFRs (eOPFRs) remain undeservedly overlooked. We elaborated on the current advancements and challenges regarding eOPFRs research and demonstrated that eOPFRs exhibit considerable diversity in terms of their chemical structures, substantial residue levels, broad sources of occurrence, and limited understanding of their potent (eco)toxicological implications. In light of these attributes, it becomes evident that the environmental and health risks of eOPFRs can be comparable to, if not surpass, those attributed to traditional OPFRs. This compelling observation underscores an imperative need for heightened research focus and extensive research efforts dedicated to the study of eOPFRs, rather than still focusing on the realm of their traditional counterparts. Despite the challenges ahead, the emphasized environmental surveillance and toxicological assessment are imperative to prevent the potential evolution of these compounds into a significant ecological and human health threat.

Effects of chitosan and rice husk powder on thermal hydrolysis-anaerobic digested sludge conditioning: Dewaterability and biogas slurry fertility.

To enhance the dewaterability of anaerobic digested sludge and to make full use of the biogas slurry. This study set up five sludge conditioning methods: polymeric ferric sulfate, polymeric aluminum chloride, cationic polyacrylamide, chitosan, and chitosan combined with rice husk powder. Their effects on the dewaterability of thermal hydrolysis-anaerobic digested sludge, bacterial community, and biogas slurry fertility were studied to find a non-toxic and non-risk dewatering technology for the environment and biogas slurry. Compared with that of the control group, moisture content, normalization capillary suction time, and specific resistance to filtration were reduced by 12.8%, 97.7%, and 82.9%, respectively. Chitosan enlarges the sludge flocs and forms complexes with proteins, disrupting the structure of the extracellular polymeric substances, thereby exposing more hydrophobic groups and reducing the hydrophilicity of the sludge. The subsequent addition of rice husk powder enhances the adsorption of hydrophilic substances and provides a stronger drainage channel for the sludge. In addition, the biogas slurry obtained by this conditioning method used as a fertilizer increased the dry weight and fresh weight of corn seedlings by 59.3% and 91.0%, respectively. And the total chlorophyll content increased by 84.6%. Pearson's correlation analysis showed that chitosan and rice husk meal had no toxic effect on the biogas slurry compared to the other three flocculants. The results showed that the combined treatment of chitosan and rice husk powder resulted in the best dewaterability. Overall, chitosan combined with rice husk powder is a green dewatering technology with great potential for anaerobic digested sludge dewatering and biogas slurry recycling.

Classification and prognostic factors of patients with cervical spondylotic myelopathy after surgical treatment: a cluster analysis.

Identifying potential prognostic factors of CSM patients could improve doctors' clinical decision-making ability. The study retrospectively collected the baseline data of population characteristics, clinical symptoms, physical examination, neurological function and quality of life scores of patients with CSM based on the clinical big data research platform. The modified Japanese Orthopedic Association (mJOA) score and SF-36 score from the short-term follow-up data were entered into the cluster analysis to characterize postoperative residual symptoms and quality of life. Four clusters were yielded representing different patterns of residual symptoms and quality of patients' life. Patients in cluster 2 (mJOA RR 55.8%) and cluster 4 (mJOA RR 55.8%) were substantially improved and had better quality of life. The influencing factors for the better prognosis of patients in cluster 2 were young age (50.1 ± 11.8), low incidence of disabling claudication (5.0%) and pathological signs (63.0%), and good preoperative SF36-physiological function score (73.1 ± 24.0) and mJOA socre (13.7 ± 2.8); and in cluster 4 the main influencing factor was low incidence of neck and shoulder pain (11.7%). We preliminarily verified the reliability of the clustering results with the long-term follow-up data and identified the preoperative features that were helpful to predict the prognosis of the patients. This study provided reference and research basis for further study with a larger sample data, extracting more patient features, selecting more follow-up nodes, and improving clustering algorithm.

NIR-responsive injectable magnesium phosphate bone cement loaded with icariin promotes osteogenesis.

There were defects like limited osteogenesis and fast drug release in traditional magnesium phosphate bone cement (MPC). In this study, we loaded icariin in a mesoporous nano silica container modified by polydopamine and then added it and citric acid into MPC (IHP-CA MPCs). The results indicate that IHP-CA MPCs have a long curing time, almost neutral pH value, excellent injectability, and compressive strength. In vitro experiments have shown that IHP-CA MPCs have good biocompatibility and bone promoting ability. These improvements provide feasible solutions and references for the clinical application of MPCs as implants.

Incorporating pH/NIR responsive nanocontainers into a smart self-healing coating for a magnesium alloy with controlled drug release, bacteria killing and osteogenesis properties.

Magnesium (Mg)-based orthopedic implant materials can potentially be protected from deterioration using a protective polymer coating. However, this coating is susceptible to excessive corrosion and accidental scratches. Moreover, the inadequate bone integration and infections associated with bone implants present additional challenges that hinder their effective use. In this work, a spin-spray layer-by-layer (SSLbL) assembly technique was employed to develop a smart self-healing coating for Mg alloy WE43. This coating was based on paeonol-encapsulated nanocontainers (PMP) that were modified with a stimuli-responsive polydopamine (PDA). The leached paeonol could form a compact chelating layer when complexed with Mg2+ ions. Dynamic reversible hydrogen bonds were formed between assembly units, which ensured that the hybrid coating possessed rapid and cyclic self-healing properties. Under 808 nm near-infrared (NIR) laser irradiation, the self-healing coating exhibited antibacterial properties due to the synergistic effects of hyperthermia, reactive oxygen species (ROS), and paeonol. In addition, the incorporation of nanoparticles into the hybrid coating led to improvements in the cytocompatibility and osteogenic properties of the implant material. The smart coating enhanced alkaline phosphatase activity, extracellular matrix (ECM) mineralization, and the expression of osteogenic genes. This study presents a promising opportunity to explore the application of a smart self-healing coating for a Mg alloy. STATEMENT OF SIGNIFICANCE: Herein, we report a self-healing coating comprised of polyethyleneimine and nanocontainer-crosslinked hyaluronic acid to achieve drug-controlled release, antimicrobial activity, and osteogenesis performance. The formation of hydrogen bonds between HA and PEI facilitated the self-assembly process, thereby improving the coating's corrosion resistance and adhesion strength. The hybrid coating exhibited a rapid and cyclic self-healing activity due to paeonol and dynamic reversible bonds. The release of paeonol was controlled by pH and NIR stimuli owing to polydopamine modification. In vitro testing revealed that the hybrid coating achieved effective bacteria eradication through synergistic effects of hyperthermia, reactive oxygen species, and paeonol. Moreover, the smart coating was found to enhance alkaline phosphatase activity, extracellular matrix mineralization, and the expression of osteogenic genes.

Organophosphate ester cresyl diphenyl phosphate disrupts lipid homeostasis in zebrafish embryos.

As a new class of organophosphate ester, cresyl diphenyl phosphate (CDP) has been widely monitored in environmental matrices and human samples, nonetheless, its toxicity is not fully understood. Here we described an in-depth analysis of the disruptions in lipid homeostasis of zebrafish following exposure to CDP concentrations ranging from 2.0 to 313.0 µg/L. Nile red staining revealed significant alterations in lipid contents in 72 hpf zebrafish embryos at CDP concentrations of 5.3 µg/L and above. Lipidomic analysis unveiled substantial disruptions in lipid homeostasis. Notably, disruptive effects were detected in various lipid classes, including phospholipids (i.e. cardiolipin, lysophosphatidylcholine, and phosphatidylethanolamine), glycerolipids (triglycerides), and fatty acids (fatty acids (FA) and wax esters (WE)). These alterations were further supported by transcriptional changes, with remarkable shifts observed in genes associated with lipid synthesis, transport, and metabolism, encompassing phospholipids, glycerolipids, fatty acids, and sphingolipids. Furthermore, CDP exposure elicited a significant elevation in ATP content and swimming activity in embryos, signifying perturbed energy homeostasis. Taken together, the present findings underscore the disruptive effects of CDP on lipid homeostasis, thereby providing novel insights essential for advancing the health risk assessment of organophosphate flame retardants.

Self-Assembled Multilayered Coatings with Multiple Cyclic Self-Healing Capability, Bacteria Killing, Osteogenesis, and Angiogenesis Properties on Magnesium Alloys.

Self-healing coatings improve the durability of magnesium (Mg) implants, but rapid corrosion still poses a challenge in the healing stage. Moreover, Mg-based materials with acceptable bacteria killing, osteogenic and angiogenic properties are challenging in biomedical applications. Herein, the self-healing polymeric coatings are fabricated on Mg alloys using the spin-assisted layer-by-layer (SLbL) assembly of hyaluronic acid (HA) and branched polyethyleneimine (bPEI) followed by chemical crosslinking treatment. The self-healing coatings show excellent adhesion strength and structure stability. The corrosion resistance is improved due to the physical barrier of polymer coatings, which also promotes the formation of hydroxyapatite (HAp) during degradation for further protection of Mg substrate. Owing to the dynamic reversible hydrogen bonds existing between HA and bPEI, the crosslinked multilayered coatings possess fast, substantial, and cyclic self-healing capabilities leading to restoration of the original structure and functions. In vitro investigations reveal that the self-healing coatings have multiple functionalities pertaining to bacteria killing, cytocompatibility, osteogenesis, as well as angiogenesis. In addition, the self-healing coatings stimulate alkaline phosphatase activity (ALP), extracellular matrix (ECM) mineralization, and the expression of osteogenesis-related genes of mBMSCs and HUVECs. This study reveals a feasible strategy to design and prepare versatile self-healing coatings on Mg implants for biomedical applications.

Prednisolone Accelerates Embryonic Development of Zebrafish via Glucocorticoid Receptor Signaling at Low Concentrations.

Synthetic glucocorticoids have been widely detected in aquatic ecosystems and may pose a toxicological risk to fish. In the present study, we described multiple end point responses of zebrafish to a commonly prescribed glucocorticoid, prednisolone (PREL), at concentrations between 0.001 and 9.26 µg/L. Of 23 end points monitored, 7 were affected significantly. Significant increases in the frequency of yolk extension formation, spontaneous contraction, heart rate, and ocular melanin density and significant decreases of ear-eye distance at PREL concentrations of 0.001 µg/L and above clearly pointed to the acceleration of embryonic development of zebrafish by PREL. Further confirmation came from the alterations in somite numbers, head-trunk angle, and yolk sac size, as well as outcomes obtained via RNA sequencing, in which signaling pathways involved in tissue/organ growth and development were highly enriched in embryos upon PREL exposure. In addition, the crucial role of glucocorticoid receptor (GR) for PREL-induced effects was confirmed by both, the coexposure to antagonist mifepristone (RU486) and GR-/- mutant zebrafish experiments. We further demonstrated similar accelerations of embryonic development of zebrafish upon exposure to 11 additional glucocorticoids, indicating generic adverse effect characteristics. Overall, our results revealed developmental alterations of PREL in fish embryos at low concentrations and thus provided novel insights into the understanding of the potential environmental risks of glucocorticoids.

Predictive Value of Preoperative Short Form-36 Survey Scale for Postoperative Axial Neck Pain in Patients With Degenerative Cervical Myelopathy.

STUDY DESIGN: Prospective observational study. OBJECTIVE: To evaluate the predictive value of the preoperative Short Form-36 survey (SF-36) scale for postoperative axial neck pain (ANP) in patients with degenerative cervical myelopathy (DCM) who underwent anterior cervical decompression and fusion (ACDF) surgery. METHODS: This study enrolled patients with DCM who underwent ACDF surgery at author's Hospital between May 2010 and June 2016. RESULTS: Out of 126 eligible patients, 122 completed the 3-month follow-up and 117 completed the 1-year follow-up. The results showed that the preoperative social functioning (SF) subscale score of the SF-36 scale was significantly lower in patients with moderate-to-severe postoperative ANP than in those with no or mild postoperative ANP at both follow-up timepoints (P < .05). ACDF at C4-5 level resulted in a higher ANP rate than ACDF at C5-6 or C6-7 level, both at 3-month (P = .019) and 1-year (P = .004) follow-up. Multivariate logistic regression analysis confirmed that the preoperative social functioning subscale score was an independent risk factor for moderate-to-severe postoperative ANP at 3 months and 1 year after surgery, and preoperative NRS was an independent risk factor at 1-year follow-up. No other demographic, clinical, or radiographic factors were found to be associated with postoperative ANP severity (P < .05). CONCLUSIONS: Preoperative social functioning subscale score of SF-36 scale might be a favorable predictive tool for postoperative ANP in DCM patients who underwent ACDF surgery.

Systematic analysis of circadian disrupting substances with a high-throughput zebrafish circadian behavior screening approach.

Circadian rhythm aligns numerous biological functions in majority of animals. Aside from well-known external factors such as the light-dark cycle and temperature, circadian rhythm can also be regulated by rarely explored factors such as synthetic substances. Here, we established a circadian behavior screening approach utilizing zebrafish larvae model, which integrated high-throughput capabilities with automated batch processing. With this approach, we systematically analyzed the circadian disruptive effects of >60 synthetic substances commonly detected in aquatic environment by assessing both the circadian period length and amplitude of circadian behavior, with an exposure concentration set at 100 µg/L. Among tested substances, a series of circadian disrupting compounds (circadian disruptors) were identified. Several categories of the hit compounds can be recognized, such as phthalate (diisopentyl phthalate (DIPP), with 10.1 % and 49.6 % increases for circadian period length and amplitude, respectively), neuroactive substance (mirtazapine, with 10.6 % and 63.1 % increases, respectively), and biocides (thiamethoxam, with 100.3 % increase for amplitude). Among these compounds, DIPP increased circadian period length and amplitude with a high degree. Aside from DIPP, we further examined eleven other phthalates and demonstrated that benzyl butyl phthalate, diisobutyl phthalate and diisohexyl phthalate could also significantly increase the zebrafish circadian period length by 7.9 %, 3.7 % and 8.5 %, respectively. Collectively, the present findings substantiated the feasibility of this high throughput screening strategy for circadian disruptor's discovery and provided novel insights into understanding of the potential risks of synthetic substances.

Vanadium-catalyzed Hydration of 2-Cyanopyrazine to Pyrazinamide with Unique Substrate Specificity.

Pyrazinamide is an important medicine used for the treatment of tuberculosis(TB). The preparation of pyrazinamide via catalytic hydration of 2-cyanopyrazine is of great economic interest with high atomic economy. Heterogeneous non-precious transition metal-catalyzed hydration of nitriles under neutral reaction conditions would be rather attractive. Herein vanadium-nitrogen-carbon materials were fabricated and employed for selective hydration of nitriles using water as both the solvent and reactant. 2-Cyanopyrazine could be smoothly converted into to pyrazinamide with unique substrate specificity. Additives with different N and O atoms could significantly affect hydration of 2-cyanopyrazine due to competitive adsorption/coordination in the reaction system. This work provides a new approach for non-precious metal catalyzed hydration of nitriles.

Comparative developmental toxicities of zebrafish towards structurally diverse per- and polyfluoroalkyl substances.

Structurally diverse per- and polyfluoroalkyl substances (PFASs) are increasingly detected in ecosystems and humans. Therefore, the clarification of their ecological and health risks is urgently required. In the present study, the toxicity of a series of PFASs, including PFOS, PFBS, Nafion BP1, Nafion BP2, F53B, OBS, PFOA, PFUnDA, PFO5DoDA, HFPO-TA was investigated. Similarities and differences in the developmental toxicity potentials were revealed. Our results demonstrated that PFUnDA exhibited the highest toxicity with the lowest EC50 value of 4.36 mg/L (for morphological abnormality); this was followed by F53B (5.58 mg/L), PFOS (6.15 mg/L), and OBS (10.65 mg/L). Positive correlations with volatility/solubility and chemotypes related to specific biological activity, including the bioconcentration factor (LogBCF), and negative correlations with lipid solubility and carbon chain component-related chemotypes, including the number of carbon and fluorine atoms, provided a reasonable explanation in the view of molecular structures. Furthermore, comparative transcriptome analysis provided molecular evidence for the relationship between PFASs exposure and malformations. Common differentially expressed genes (DEGs) involved in spine curve development, pericardial edema, and cell/organism growth-related pathways presented common targets, leading to toxic effects. Therefore, the present results provide novel insights into the potential environmental risks of structurally diverse PFASs and contribute to the selection of safer PFAS replacements.

Environmentally relevant concentrations of antidepressant mirtazapine impair the neurodevelopment of zebrafish (Danio rerio).

Mirtazapine is a commonly prescribed antidepressant and has been found widespread in aquatic environments. However, its toxicities to aquatic organisms has rarely been explored. Herein, we conducted a comprehensive study on the developmental effects of mirtazapine on early life stages of zebrafish at environmentally relevant concentrations (3.9 ng/L and 43.5 ng/L). Out of the endpoints measured, spontaneous contraction of embryos at 24 h post fertilization (hpf) and hatching rate and heart rate of embryos at 50 hpf and 56 hpf, respectively, were significantly affected. In light-dark transition behavior test, mirtazapine significantly reduced the swimming frequency and swimming speed of embryos at both concentrations of 3.9 ng/L and 43.5 ng/L. Furthermore, the total swimming distances in dark conditions were also significantly reduced. Transcriptomic analysis was further conducted. It demonstrated that the decreased neural activities in embryos may be associated with altered epinephrine and neuregulin signaling. The present results fill a data gap regarding the exposure of fish to mirtazapine at environmentally relevant concentrations and provide new insights into the neurotoxic mechanisms of mirtazapine exposure.

Prioritization of risks posed by synthetic chemicals manufactured in China toward humans and the environment via persistence, bioaccumulation, mobility and toxicity properties.

Over a third of the global chemical production and sales occurred in China, which make effective assessment and management for chemicals produced by China's chemical industry essential not just for China but for the world. Here, we systematical assessed the persistence (P), bioaccumulation (B), mobility (M) and toxicity (T) potency properties for the chemicals listed in Inventory of Existing Chemical Substances of China (IECSC) via experimental data retrieved from large scale databases and in silico data generated with well-established models. Potential PBT, PMT and PB&MT substances were identified. High risk potentials were highlighted for groups of synthetic intermediates, raw materials, as well as a series of biocides. The potential PBT and PMT synthetic intermediates and/or raw materials unique to the IECSC were dominated with organofluorines, for example, the intermediates used as electronic light-emitting materials. Meanwhile, the biocides unique to the IECSC were mainly organochlorines. Some conventional classes of insecticides, such as organochlorines and pyrethroids, were classified as being of high concern. We further identified a group of PB&MT substances that were considered to be both "bioaccumulative" and "mobile". Their properties and common substructures for several major clusters were characterized. The present results prioritized groups of substances with high potentials to cause adverse effects to the environment and humans, many of which have not yet been fully recognized.