Applications of optical property measurement for quality evaluation of agri-food products: a review.

Spectroscopic techniques coupled with chemometric approaches have been widely used for quality evaluation of agricultural and food (agri-food) products due to the nondestructive, simple, fast, and easy characters. However, these techniques face the issues or challenges of relatively weak robustness, generalizability, and applicability in modeling and prediction because they measure the aggregate amount of light interaction with tissues, resulting in the combined effect of absorption and scattering of photons. Optical property measurement could separate absorption from scattering, providing new insights into more reliable prediction performance in quality evaluation, which is attracting increasing attention. In this review, a brief overview of the currently popular measurement techniques, in terms of light transfer principles and data analysis algorithms, is first presented. Then, the emphases are put on the recent advances of these techniques for measuring optical properties of agri-food products since 2000. Corresponding applications on qualitative and quantitative analyses of quality evaluation, as well as light transfer simulations within tissues, were reviewed. Furthermore, the leading groups working on optical property measurement worldwide are highlighted, which is the first summary to the best of our knowledge. Finally, challenges for optical property measurement are discussed, and some viewpoints on future research directions are also given.

HighlightsEmerging techniques for measuring optical properties are briefly introducedQualitative analyses of maturity evaluation and defect detection are reviewedQuantitative analyses of attribute prediction and microstructure estimation are presentedLight transfer simulations based on optical properties are comprehensively discussedLeading groups are summarized for the first time, to the best of our knowledgeChallenges and prospects for optical property measurement are given.

Biochar amendment reassembles microbial community in a long-term phosphorus fertilization paddy soil.

This study investigates the effect of biochar amendment on microbial community structure and soil nutrient status in paddy soil that has been fertilized for an extended period of time, shedding light on sustainable agricultural practices. A 90-day incubation period revealed that biochar amendment, as opposed to long-term fertilization, significantly influenced the physicochemical properties and microbial composition of the soil. The microcosm experiment conducted using six treatments analyzed soil samples from a long-term rice ecosystem. We employed microbial biomarkers (phospholipid fatty acids, PLFAs; isoprenoid and branched glycerol dialkyl glycerol tetraethers, iGDGTs and brGDGTs; DNA) to assess microbial biomass and community structure. Biochar addition led to a decrease in PLFA biomass (15-32%) and archaeal iGDGT abundance (14-43%), while enhancing bacterial brGDGT abundance by 15-77%. Intact biochar increased archaeal and bacterial diversity, though fungal diversity remained unchanged. However, acid-washed biochar did not result in a uniform microbial diversity response. The abundance of various microbial taxa was changed by biochar amendment, including Crenarchaeota, Proteobacteria, Nitrospira, Basidiomycota, Halobacterota, Chloroflexi, Planctomycetota, and Ascomycota. Soil NH4+-N was found as the primary environmental factor impacting the composition of archaea, bacteria, and fungus in this study. These findings imply that the addition of biochar has a quick influence on the structure and activity of microbial communities, with fungi possibly having a critical role in acid paddy soil. This study contributes valuable knowledge for developing sustainable agricultural practices that promote healthy soil ecosystems. KEY POINTS: • Biochar type and phosphorus fertilization demonstrated an interactive effect on the diversity of archaea, but no such effect was observed for bacteria and fungi. • Soil fungi contribute to approximately 20% of the total phospholipid fatty acid (PLFA) content. • Biochar, especially acid-washed rice straw biochar, increases glucose metabolism in bacteria and archaea and decreases saprophytic fungi.

Substituent-Controllable Cascade Regioselective Annulation of ß-Enaminones with N-Sulfonyl Triazoles for Modular Access to Imidazoles and Pyrroles.

A controllable synthesis of trisubstituted imidazoles and pyrroles has been developed through rhodium(II)-catalyzed regioselective annulation of N-sulfonyl-1,2,3-trizaoles with ß-enaminones. The imidazole ring was formed through a 1,1-insertion of the N-H bond to α-imino rhodium carbene, followed by a subsequent intramolecular 1,4-conjugate addition. This occurred when the α-carbon atom of the amino group was bearing a methyl group. Additionally, the pyrrole ring was constructed by utilizing a phenyl substituent and undergoing intramolecular nucleophilic addition. The mild conditions, good tolerance towards functional groups, gram-scale synthesis capability, and ability to undergo valuable transformations of the products qualify this unique protocol as an efficient tool for the synthesis of N-heterocycles.

Construction of isoxazolone-fused phenanthridines via Rh-catalyzed cascade C-H activation/cyclization of 3-arylisoxazolones with cyclic 2-diazo-1,3-diketones.

A Rh(iii)-catalyzed cascade C-H activation/intramolecular cyclization of 3-aryl-5-isoxazolones with cyclic 2-diazo-1,3-diketones was described, leading to the formation of isoxazolo[2,3-f]phenanthridine skeletons. The protocol features the simultaneous one-pot formation of two new C-C/C-N bonds and one heterocycle in moderate-to-good yields with good functional group compatibility. It is amenable to large-scale synthesis and further transformation.

A Biocompatible Multilayer Film from an Asymmetric Picolinium-Containing Polycation with Fast Visible-Light/NIR-Degradability.

Finely tuning the photodegradation behavior of the layer-by-layer (LbL) film from the view of controlling the chemical structure of the film-building polymer is still a challenge in related fields. To meet this requirement, a photodegradable polymer (P1) is rationally designed for assembling a visible-light-degradable multilayer film with polystyrene sulfonate (PSS). Compared with similar photopolymers (P2 and P3), this asymmetric picolinium-containing polymer can significantly enhance the degradation rate of as-prepared LbL films; under the same degradation condition, the degradation rate of (P1/PSS)10 is 3 and 6.6 times that of (P2/PSS)10 and (P3/PSS)10, respectively. Moreover, near-infrared light (NIR) is available for triggering the degradation of this film with the assistance of upconversion nanoparticles of YbTm@Lu. The cell cytotoxicity and cell proliferation experiments reveal that P1 is nontoxic and favorable for cell proliferation at concentrations of up to 500 µg mL-1 . As for (PSS/P1)10 films, the ratio of cell number of these two samples ((PSS/P1)10 modified: photodegraded) increases dramatically and reaches about 1.67:1 after 72 h incubation. On the basis of these results, it is anticipated that P1 and this LbL film is an exceptional candidate for visible-light/NIR degradable materials in materials and biological science, medicine, and optics.

Effects of 1-Alkyl-3-Methylimidazolium Nitrate on Soil Physical and Chemical Properties and Microbial Biomass.

Ionic liquids (ILs), also called room temperature ILs, are widely applied in many fields on the basis of their unique physical and chemical properties. However, numerous ILs may be released into and gradually accumulate in the environment due to their extensive use and absolute solubility. The effects of 1-alkyl-3-methylimidazolium nitrate ([Cnmim]NO3, n = 4, 6, 8) on soil pH, conductivity, cation exchange capacity, microbial biomass carbon, and microbial biomass nitrogen were examined at the doses of 1, 10, and 100 mg/kg on days 10, 20, 30, and 40. The results demonstrated that the soil pH decreased and the conductivity increased with increasing IL doses. No significant differences were observed in the soil cation-exchange capacity. All three of the tested ILs decreased the soil microbial biomass carbon and nitrogen. Additionally, there were few differences among the ILs with different alkyl chain lengths on the tested indicators except for the microbial biomass nitrogen. The present study addressed a gap in the literature regarding the effects of the aforementioned ILs with different alkyl side chains on the physicochemical properties of soil, and the results could provide the basic data for future studies on their toxicity to soil organisms, such as earthworms and soil microbes.

Effects of 1-octyl-3-methylimidazolium nitrate on the microbes in brown soil.

The toxicity of ionic liquids (ILs) on soil organisms has aroused wide attention due to their high-solubility. The present investigation focused on the toxicity of 1-octyl-3-methylimidazolium nitrate ([C8mim]NO3) on the microbial populations (bacteria, fungi, and actinomycetes), soil enzyme (urease, dehydrogenase, acid phosphatase, and ß-glucosidase) activities, microbial community diversity using terminal restriction fragment length polymorphism (T-RFLP), and abundance of the ammonia monooxygenase (amoA) genes of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) using quantitative real-time polymerase chain reaction (q-PCR) in brown soil at each trial with doses of 0, 1.0, 5.0, and 10.0mg/kg on days 10, 20, 30, and 40. The contents of [C8mim]NO3 in soil were measured using high performance liquid chromatography with recoveries of 84.3% to 85.2%, and changed less than 10% during the experimental period. A significant decrease was observed from the bacteria, fungi and actinomycetes populations at 10.0mg/kg, at which the urease activity was inhibited and the ß-glucosidase activity was stimulated on days 20, 30, and 40. In addition, [C8mim]NO3 inhibited the dehydrogenase activity at 10mg/kg on days 30 and 40 and the acid phosphatase activity on day 20. The diversity of the soil microbial community and the gene abundance of AOA- and AOB- amoA were also inhibited. Furthermore, the present investigation provided more scientific information for the toxicity evaluation of ILs in soil.

Determination of Residual Concentration of Ionic Liquids with Different Anions and Alkyl-Chain Lengths in Water and Soil Samples.

Considering the wide synthesis and application of ionic liquids (ILs), the toxicity of ILs has recently gained growing attention. However, few studies focused on IL determination methods in environmental samples. In the present study, we implemented the determination methods for the 12 ILs with different chemical structures using high-performance liquid chromatography (HPLC) and ultraviolet (UV) spectrophotometry. The optimum conditions for extraction of ILs from soil samples were also obtained by single-factor experiments and response surface methodology (RSM). The instrument detection limits (IDLs) reached 10-10 g. Compared to the use of UV, HPLC had the standard curve with stronger correlation (R2 ≥ 0.999) and lower detection limit. We therefore used HPLC to detect the contents of ILs in water and soil samples. A standard adding method was used for the reliability test of the above methods. The average recovery in water samples was 90.46%-108.83%, and the coefficient of variation (CV) was 0.51%-9.07%. The method detection limits (MDLs) were below 0.1 mg/L. The optimized IL extraction conditions in soil samples were as follows: The ratio of methanol and saturated ammonium chloride was 90:10, the ultrasonic time was 50 min, and the power was 350 W. The average recovery in soil samples was 70.39%-85.30%, and the CV was 0.50%-9.99%. The MDLs were below 1 mg/kg. These results using the aforementioned methods met the standards of residue analysis. The present study can provide scientific analysis methods and a basis for evaluation of the study of IL residues in environmental samples.

The acute toxic effects of imidazolium-based ionic liquids with different alkyl-chain lengths and anions on zebrafish (Danio rerio).

With the increasing applications of ionic liquids (ILs), the toxicity of ILs has drawn increasing attention in recent years, especially the influences of different anions and alkyl-chain lengths on the acute toxicity to aquatic organisms. We performed a study on the acute toxicity of 1-alkyl-3-methylimidazolium nitrate ([Cnmim]NO3 (n=2, 4, 6, 8, 10, 12)), 1-hexyl-3-methylimidazolium ILs ([C6mim]R (R=Cl-, Br-, BF4-, PF6-)) to zebrafish (Danio rerio). We also evaluated the sensibility of the investigated animals and the stability of ILs in water via high performance liquid chromatography (HPLC, Agilent 1260, Agilent Technologies Inc., USA) to prove the reliability of the present study. The results illustrated that the test zebrafish (Danio rerio) were sensitive to the reference toxicant and that the investigated ILs in water were stable. The 50% lethal concentration (LC50) was used to represent the acute toxicity to zebrafish (Danio rerio). The present study showed that the highest toxic IL is [C12mim]NO3 and the lowest toxic IL is [C2mim]NO3 on Danio rerio. The LC50s for ILs with different anions had similar values. Accordingly, we believe that ILs with different alkyl-chain lengths cause greater effects than other anions on acute toxicity to aquatic organisms. Furthermore, the present study can also provide scientific methods for future studies to select and assess ILs.

The water-retaining functional slow-release fertilizer modified by carboxymethyl chitosan.

To solve the problem of shortage of agricultural water resources and low utilization rate of fertilizer, a slow-release fertilizer based on chitosan modified water retention function was developed. Solution polymerization and semi-interpenetrating network technology were used to load urea aldehyde into carboxymethyl chitosan superabsorbent resin network. This technology realizes the simultaneous slow release of nutrients and water by using modified chitosan, which has important implications for the application of chitosan in agriculture to regulate the soil water and fertilizer conditions. The optimal preparation conditions were: MBA 0.07 %, KPS 0.8 %, AM to AA mass ratio of 0.3:1, CMC content of 10 %, AA neutralization degree 85 %, UF 20 %, AA+AM mass sum of 10 g, reaction temperature 70 °C and reaction time 2 h. The maximum water absorption rate of the optimized NC reached 172.3 g/g. The cumulative release of nitrogen in 30 days was 83.67 %. The application of NC in sandy soil promoted seed germination and growth. The comprehensive results indicate that NC has broad application prospects in arid areas based on its excellent water retention and nutrient release performance.

Interaction of reed litter and biochar presences on performances of constructed wetlands.

Constructed wetlands (CWs) are frequently used for effective biological treatment of nitrogen-rich wastewater with external carbon source addition; however, these approaches often neglect the interaction between plant litter and biochar in biochar-amended CW environments. To address this, we conducted a comprehensive study to assess the impacts of single or combined addition of common reed litter and reed biochar (pyrolyzed at 300 and 500 °C) on nitrogen removal, greenhouse gas emission, dissolved organic matter (DOM) dynamics, and microbial activity. The results showed that combined addition of reed litter and biochar to CWs significantly improved nitrate and total nitrogen removal compared with biochar addition alone. Compared to those without reed litter addition, CWs with reed litter addition had more low-molecular-weight and less aromatic DOM and more protein-like fluorescent DOM, which favored the enrichment of bacteria associated with denitrification. The improved nitrogen removal could be attributed to increases in denitrifying microbes and the relative abundance of functional denitrification genes with litter addition. Moreover, the combined addition of reed litter and 300 °C-heated biochar significantly decreased nitrous oxide (30.7 %) and methane (43.9 %) compared to reed litter addition alone, while the combined addition of reed litter and 500 °C-heated biochar did not. This study demonstrated that the presences of reed litter and biochar in CWs could achieve both high microbial nitrogen removal and relatively low greenhouse gas emissions.

Network interpenetrating slow-release nitrogen fertilizer based on carrageenan and urea: A new low-cost water and fertilizer regulation carrier.

Modern agriculture presents new requirements of low cost, high water retention and degradability for superabsorbent and slow-release fertilizers. In this study, carrageenan (CG), acrylic acid (AA), N, N '-methylene diacrylamide (MBA), urea and ammonium persulfate (APS) were used as raw materials. A kind of high water absorption, water retention, nitrogen slow release and biodegradable carrageenan superabsorbent (CG-SA) was prepared by grafting copolymerization. The optimal CG-SA was obtained with a water absorption rate of 680.45 g/g by orthogonal L18(3)7 experiments and single-factor experiments. The water absorption behavior of CG-SA in deionized water and salt solution were studied. The CG-SA was characterized before and after degradation by FTIR, SEM. The nitrogen release behavior and kinetic characteristics of CG-SA were investigated. In addition, CG-SA degraded 58.33 % and 64.35 % in soil at 25 °C and 35 °C after 28 days. All the results indicated that the low-cost and degradable CG-SA can achieve simultaneous slow release of water and nutrients, which is expected to be widely used as a new water-fertilizer integration technology in arid and poor areas.

Effects of the fungicide trifloxystrobin on the structure and function of soil bacterial community.

Trifloxystrobin has been widely applied to prevent fungal diseases because of its high efficiency and desirable safety characteristics. In the present study, the effects of trifloxystrobin on soil microorganisms were integrally investigated. The results showed that trifloxystrobin inhibited urease activity, promoted dehydrogenase activity. Downregulated expressions of the nitrifying gene (amoA), denitrifying genes (nirK and nirS), and carbon fixation gene (cbbL) were also observed. Soil bacterial community structure analysis showed that trifloxystrobin changed the abundance of bacteria genera related to nitrogen and carbon cycle in soil. Through the comprehensive analysis of soil enzymes, functional gene abundance, and soil bacterial community structure, we concluded that trifloxystrobin inhibited both nitrification and denitrification of soil microorganisms, and also diminished the carbon-sequestration ability. Integrated biomarker response analysis showed that dehydrogenase and nifH were the most sensitive indicators of trifloxystrobin exposure. It provides new insights about trifloxystrobin environmental pollution and its influence on soil ecosystem.

MANF inhibits Sjögren's syndrome salivary gland epithelial cell apoptosis and antigen expression of Ro52/SSA through endoplasmic reticulum stress/autophagy pathway.

BACKGROUND: Sjögren's syndrome (SS) is a typical autoimmune disease characterized by lymphocyte infiltration accompanied by the production of Ro52/SSA and La/SSB autoantibodies against whole body ribonucleoprotein particles. The release of type I IFN can induce endoplasmic reticulum stress (ERS) in submandibular gland cells. ERS not only produces a large number of Ro52/SSA antigens and changes their location, but also down-regulates autophagy and increases apoptosis. METHOD: We collected human submandibular gland tissue samples, established an Experimental Sjögren's syndrome (ESS) mouse model, and used submandibular gland cells to test whether Mesencephalic astrocyte-derived neurotrophic factor (MANF) could reverse ERS-induced autophagy downregulation and reduce apoptosis and Ro52/SSA antigen expression. RESULT: It was found that MANF could reduce lymphocyte infiltration and the proportion of CD4+ T cell subsets in the salivary glands, reduce the phosphorylation of AKT and mTOR proteins and the expression of ERS-related proteins, and increase the expression of autophagy proteins. We also found that MANF can reduce the expression of Ro52/SSA antigen on the cell membrane and reduce apoptosis. CONCLUSION: In short, we found that MANF can activate autophagy, inhibit apoptosis and reduce the expression of Ro52/SSA by regulating the AKT/mTOR/LC3B signaling pathway. The above results suggest that MANF may be a protective factor against SS.

Analysis of Light Penetration Depth in Apple Tissues by Depth-Resolved Spatial-Frequency Domain Imaging.

Spatial-frequency domain imaging (SFDI) has been developed as an emerging modality for detecting early-stage bruises of fruits, such as apples, due to its unique advantage of a depth-resolved imaging feature. This paper presents theoretical and experimental analyses to determine the light penetration depth in apple tissues under spatially modulated illumination. Simulation and practical experiments were then carried out to explore the maximum light penetration depths in 'Golden Delicious' apples. Then, apple experiments for early-stage bruise detection using the estimated reduced scattering coefficient mapping were conducted to validate the results of light penetration depths. The results showed that the simulations produced comparable or a little larger light penetration depth in apple tissues (~2.2 mm) than the practical experiment (~1.8 mm or ~2.3 mm). Apple peel further decreased the light penetration depth due to the high absorption properties of pigment contents. Apple bruises located beneath the surface peel with the depth of about 0-1.2 mm could be effectively detected by the SFDI technique. This study, to our knowledge, made the first effort to investigate the light penetration depth in apple tissues by SFDI, which would provide useful information for enhanced detection of early-stage apple bruising by selecting the appropriate spatial frequency.

Characterization of the responses of soil micro-organisms to azoxystrobin and the residue dynamics of azoxystrobin in wheat-corn rotation fields over two years.

Azoxystrobin, a high-efficiency and broad-spectrum strobilurin fungicide, has been widely used in global agricultural production. However, the effects of azoxystrobin on soil micro-organisms have scarcely been studied, and relevant experiments are usually conducted under laboratory conditions using active ingredient. Therefore, the effects of azoxystrobin on soil micro-organisms when applied to actual farmland are unknown. We sought to address this knowledge gap in this study, where we studied the effects of azoxystrobin on soil micro-organisms in a wheat-corn rotation field over two years. The results indicate that after two years of azoxystrobin application the activities of soil enzymes were inhibited, and the abundance of functional genes related to the nitrogen and carbon cycle were inhibited, which change the abundance of soil microbial bacteria of genera. As a consequence, the soil nitrogen and carbon cycles were disturbed. In addition, azoxystrobin inhibited the abundance of functional bacteria related to organic pollutant degradation and soil metabolism, where the rate of azoxystrobin degradation diminished over time. Moreover, azoxystrobin significantly inhibited the soil-culturable microbial population. The integrated biomarker response (IBR) indicated that the soil-culturable microbial population can be used as a sensitive indicator of the effect of azoxystrobin on soil micro-organisms. The final levels of azoxystrobin residues measured in grains were less than 0.004 mg/kg, lower than the maximum residue limits in European Union and China. The results of this study provide a basis for suggestions regarding the appropriate use of azoxystrobin in addition to support for elucidating the interaction between biological macromolecules and pollutants.

Effects of applying different carbon substrates on nutrient removal and greenhouse gas emissions by constructed wetlands treating carbon-depleted hydroponic wastewater.

The addition of external carbon sources is crucial for effective biological treatment of nutrient-rich but carbon-depleted hydroponic wastewater using constructed wetlands. In this study, we examined the effects of applying three types of carbon substrates, namely sucrose, hydroponic kale residues, and common reed litter, on the nutrient removal efficiency and greenhouse gas emission rate of vertical flow constructed wetlands. The addition of sucrose and common reed litter was shown to perform equally well in enhancing the removal of total nitrogen (84.9-93.5%), nitrate (98.3-99.8%) and phosphate (53.8-55.2%) as compared to the control. Moreover, the application of common reed litter led to significantly lower mean CH4 and N2O emissions than that of kale residues. These findings suggested that Phragmites reed litter, which is easily found in wetlands worldwide, could be an effective, low-cost and climate-friendly carbon substrate to be applied in constructed wetlands for hydroponic wastewater treatment.

Effects of particle size distribution of potato starch granules on rheological properties of model dough underwent multiple freezing-thawing cycles.

In order to elucidate the mechanism underlying the effect of different-sizes potato starch on dough during freeze-thaw treatment, the rheological properties, moisture distribution, secondary structure, and relative crystallinity of dough were investigated. The results showed that the storage modulus (G'), loss modulus (G″), and complex modulus (|G*|) of dough increased as a result of the freeze-thaw treatment, and the effect was more obvious as the starch granular sizes increased. The higher ß -sheet and T22 contents reflected the higher viscoelasticity and freeze-thaw sensitivity, which may be related to the higher degree expansion of amylose. In contrast, dough with small-sized starch had higher intermolecular interactions, and denser structure, lower water migration, showing that this has better resistance and higher stability. The presented mechanisms may contribute to the better understanding of the effects of freeze-thaw process on model dough properties.

Numerical Simulation of Failure Behavior of Brittle Heterogeneous Rock under Uniaxial Compression Test.

Rocks have formed heterogeneous characteristics after experiencing complex natural geological processes. Studying the heterogeneity of rocks is significant for rock mechanics. In this study, a linear parallel bond model with Weibull distribution in two-dimensional particle flow code (PFC2D) is adopted to study the mechanical characteristics and brittle failure mode of granite rock specimens with different heterogeneity. Firstly, we selected several combinations of key micro-parameters of the parallel bond model. Then, we subjected them to a Weibull distribution to satisfy heterogeneity, respectively. Finally, we chose one optimal combination plan after comparing the stress-strain curves of heterogeneous rock specimens. We analyzed the simulated results of heterogeneous rock specimens. The crack distribution of rock specimens under peak stress shows different characteristics: a diagonal shape in rock specimens with low heterogeneity indexes, or a rotated "y" shape in rock specimens with high heterogeneity indexes. As for failure mode, the numerical simulation results show high consistency with the laboratory experiment results. The rock specimen breaks down almost diagonally, and the whole specimen tends to form an x-shaped conjugate shear failure or the well-known "hour-glass" failure mode. With the increase of the homogeneity index of the rock specimen, the shear rupture angle becomes larger and larger. Generally, the crack number increases with time, and when the rock specimen reaches the peak failure point, the number of cracks increases sharply. The development of cracks in numerical rock specimens under compression test is a result of the coalescence of many microscopic cracks. Furthermore, tensile cracks formed initially, followed by shear behavior along the macroscopic crack plane. We also preliminarily study the mechanical characteristics of heterogeneous rock specimens with discontinuous structural planes. The discontinuous structural planes are simulated by the smooth-joint model. We can conclude that the discontinuous structural planes and the microscopic structural planes which contribute to the heterogeneity have a mutual influence on each other.

Polyhalogenated carbazoles (PHCZs) induce cardiotoxicity and behavioral changes in zebrafish at early developmental stages.

Polyhalogenated carbazoles (PHCZs) are widely present in the environment, and their health risks are of increasing concern. Available studies primarily confirm their dioxin-like toxicity mechanism based on biomarkers, such as aryl hydrocarbon receptor (AHR) and CYP1A1, while few studies have investigated their actual toxic effects at the level of individual organisms. In the present study, the developmental toxicity of two typical PHCZs with a high detection rate and high concentration in the environment (3,6-dichlorocarbazol (3,6-DCCZ) and 3,6-dibromocarbazole (3,6-DBCZ)) was investigated based on a fish embryo acute toxicity test (FET, zebrafish) and transcriptomics analysis. The 96 h LC50 values of 3,6-DCCZ and 3,6-DBCZ were 0.636 mg/L and 1.167 mg/L, respectively. Both tested PHCZs reduced the zebrafish heart rate and blocked heart looping at concentrations of 0.5 mg/L or higher. The swimming/escaping behavior of zebrafish larvae was more vulnerable to 3,6-DBCZ than 3,6-DCCZ. Transcriptomics assays showed that multiple pathways linked to organ development, immunization, metabolism and protein synthesis were disturbed in PHCZ-exposed fish, which might be the internal mechanism of the adverse effects. The present study provides evidence that PHCZs cause cardiac developmental toxicity and behavioral changes and improves our understanding of their health risks.