Ecological risks of high-ammonia environment with inhibited growth of Daphnia magna: Disturbed energy metabolism and oxidative stress.

High ammonia pollution is a common problem in water bodies. However, research on the mechanisms underlying the toxic effects on organisms at different nutritional levels is still insufficient. Herein, based on the environmental concentration, the toxic effects of high ammonia pollution on Daphnia magna were investigated. Overall, the feeding and filtration rates of D. magna were significantly decreased by ammonia. Growth inhibition of D. magna by ammonia was confirmed by the decreased body length. After ammonia exposure, the metabolic status of D. magna changed, the correlation network weakened, and the correlations between metabolites were disrupted. Changes occurred in metabolites primarily involved in oxidative stress, fatty acid oxidation, tricarboxylic acid cycle, and protein digestion, absorption, and synthesis, which were validated through alterations in multiple biomarkers. In addition, mitochondrial function was evaluated and was found to inhibit mitochondrial activity, which was accompanied by a decreased marker of mitochondrial activity contents and ATPase activity. Thus, the results suggested that energy metabolism and oxidative stress were involved in ammonia-induced growth toxicity. This study provides new insights into the impact of ammonia on aquatic ecological health.

Conductivity-mediated in situ electrochemical reconstruction of CuOx for nitrate reduction to ammonia.

The electrocatalytic nitrate reduction reaction (NO3RR) is an ideal NH3 synthesis route with ease of operation, high energy efficiency, and low environmental detriment. Electrocatalytic cathodes play a dominant role in the NO3RR. Herein, we constructed a carbon fiber paper-supported CuOx nanoarray catalyst (CP/CuOx) by an in situ electrochemical reconstruction method for NO3--to-NH3 conversion. A series of characterization techniques, such as X-ray diffraction (XRD) and in situ Raman spectroscopy, unveil that CP/CuOx is a polycrystalline-faceted composite copper nanocatalyst with a valence composition containing Cu0, Cu+ and Cu2+. CP/CuOx shows more efficient NO3--to-NH3 conversion than CP/Cu and CP/Cu2O, which indicates that the coexistence of various Cu valence states could play a dominant role. CP/CuOx with a suitable Cu2+ content obtained by adjusting the conductivity during the in situ electrochemical reconstruction process exhibited more than 90% faradaic efficiencies for the NO3RR in a broad range of -0.3 to -1.0 V vs. RHE, 28.65 mg cm-2 h-1 peak ammonia yield, and stable NO3RR efficiencies for ten cycles. These findings suggest that CP/CuOx with suitable copper valence states obtained by fine-tuning the conductivity of the electrochemical reconstruction may provide a competitive cathode catalyst for achieving excellent activity and selectivity of NO3--to-NH3 conversion.

Evaluation of Physicochemical Properties and Prebiotics Function of a Bioactive Pleurotus eryngii Aqueous Extract Powder Obtained by Spray Drying.

A bioactive Pleurotus eryngii aqueous extract powder (SPAE) was obtained by spray drying and its performance in terms of physicochemical properties, in vitro digestion, inflammatory factors, and modulation of the intestinal microbiota was explored. The results indicated that the SPAE exhibited a more uniform particle size distribution than P. eryngii polysaccharide (PEP). Meanwhile, a typical absorption peak observed at 843 cm-1 in the SPAE FTIR spectra indicated the existence of α-glycosidic bonds. SPAE exhibited higher antioxidant abilities and superior resistance to digestion in vitro. In addition, SPAE supplementation to mice significantly reduced the release of factors that promote inflammation, enhanced the secretion of anti-inflammatory factors, and sustained maximum production of short-chain fatty acids (SCFAs). Additionally, it significantly enhanced the relative abundance of SCFAs-producing Akkermansia and reduced the abundance of Ruminococcus and Clostridiides in intestines of mice. These results show the potential of SPAE as a novel material with prebiotic effects for the food and pharmaceutical industries.

Migration and transformation behaviors of antibiotics in water-sediment system under simulated light and wind waves.

Antibiotics can generally be detected in the water-sediment systems of lakes. However, research on the migration and transformation of antibiotics in water-sediment systems based on the influences of light and wind waves is minimal. To address this research gap, we investigated the specific impacts of light and wind waves on the migration and transformation of three antibiotics, norfloxacin (NOR), trimethoprim (TMP), and sulfamethoxazole (SMX), under simulated light and wind waves disturbance conditions in a water-sediment system from Taihu Lake, China. In the overlying water, NOR was removed the fastest, followed by TMP and SMX. Compared to the no wind waves groups, the disturbance of big wind waves reduced the proportion of antibiotics in the overlying water. The contributions of light and wind waves to TMP and SMX degradation were greater than those of microbial degradation. However, the non-biological and biological contributions of NOR to degradation were almost equal. Wind waves had a significant impact on the microbial community changes in the sediment, especially in Methylophylaceae. These results verified the influence of light and wind waves on the migration and transformation of antibiotics, and provide assistance for the risk of antibiotic occurrence in water and sediments.

Supramolecular Interaction Modulation in Thermosensitive Composites: Enantiomeric Recognition and Chiral Site Regeneration.

Herein, a novel strategy was implemented to modulate the supramolecular interaction between enantiomers and chiral recognition sites (CRSs), effectively resolving the issue of CRS saturation. Randomly methylated-ß-cyclodextrin (Rm-ß-CD) was used as the CRS (host molecule), and polymerized ionic liquids [poly([vbim]TFSI)] were used as the supramolecular modulator (guest molecule), which self-assembled to generate thermosensitive supramolecular host/guest complexes. The enantiomeric binding capacity and enantioselectivity of chiral separation systems centered on supramolecular host-guest complexes are characterized by a high degree of temperature dependence. Poly([vbim]TFSI) bonded to Rm-ß-CD at temperatures between 17 °C ± 3 and 50 °C ± 3 °C, and the binding free energy difference (|ΔΔG|) between the (S)- and (R)-enantiomer was 0.55. Conversely, poly([vbim]TFSI detached from Rm-ß-CD at temperatures >50 °C ± 3 °C or <17 °C ± 3 °C, and |ΔΔG| between (S)- and (R)-enantiomer was 0.03. The |ΔΔG| value of the (R)-enantiomer can reach 0.86 in two temperature intervals. Therefore, the binding of poly([vbim]TFSI) to Rm-ß-CD afforded the favorable separation of four racemic sample mixtures: mandelic acid (e.e.% = 61.3%), ibuprofen (e.e.% = 21.6%), warfarin (e.e.% = 14.9%), and naproxen (e.e% = 18.2%). The detachment of poly([vbim]TFSI) from Rm-ß-CD released the enantiomer bound to CRSs. The decomplexation of mandelic acid reached 75.1%.

2,2-Dichloroacetamide exposure induces behavior and memory disorders in mice: Detrimental effects of long-term dietary restriction on neurotoxicity.

2, 2-dichloroacetamide (DCAcAm), a nitrogen-containing disinfection byproduct (DBPs), is commonly found in potable water. This study aimed to compare the neurotoxicity of DCAcAm in C57/BL6 mice at both environmentally relevant and higher doses through oral exposure over a 28-day period. Furthermore, the potential effects of dietary restriction (DR) on the cerebral toxicity induced by 20 ppb DCAcAm were examined. The findings indicated that DCAcAm exposure and DR treatment resulted in reduced memory retention and cognitive adaptability in mice. Additionally, higher doses of DCAcAm exposure induced severe brain inflammation and oxidative stress. Metabolic profiling revealed disruptions in fatty acid, energy, and amino acid metabolism in the brain. Remarkably, the negative impacts of 20 ppb DCAcAm on the mice brain were worsened by DR treatment. Analysis of 16S rRNA sequencing revealed notable changes in the composition and structure of intestinal microorganisms after exposure to DCAcAm. This study discovered that DCAcAm has both direct effects on the brain and indirect effects through the microbial-brain-intestinal axis, which collectively result in neurotoxicity and dietary restriction exacerbates these effects. This study provides emerging views on the assessment of the toxicity of nitrogen containing DBPs.

Enhancing oral delivery and anticancer efficacy of 7-ethyl-10-hydroxycamptothecin through self-assembled micelles of deoxycholic acid grafted N'-nonyl-trimethyl chitosan.

Irinotecan (CPT-11) is used as a first or second-line chemotherapy drug for the treatment and management of colorectal cancers. In vitro studies have shown that 7-ethyl-10-hydroxycamptothecin (SN38), the active metabolite of CPT-11, displays promising anticancer efficacy. However, its poor aqueous solubility and hydrolytic degradation result in its lower oral bioavailability and impracticable clinical application. To overcome these limitations, a novel amphiphilic chitosan derivative, deoxycholic acid decorated N'-nonyl-trimethyl chitosan, was synthesized. Nano-micelles loaded with SN38 were subsequently prepared to enhance the bioavailability and anti-tumor efficacy of the drug through oral administration. The nano-micelles demonstrated improved dilution stability, enhanced greater mucosal adherence, significant P-gp efflux inhibition, and increased drug transport in the intestine by paracellular and transcellular pathways. Consequently, both the in vivo pharmacokinetic profile and therapeutic efficacy of SN38 against cancer were substantially improved via the micellar system. Thus, the developed polymeric micelles can potentially enhance the SN38 oral absorption for cancer therapy, offering prospective avenues for further exploration.

Influence by varying organic matter content and forms in suspended particulate matter: impacts on the adsorption of tetracycline and norfloxacin.

Antibiotics are commonly detected in natural waters. The organic matter (OM) in suspended particulate matter (SPM) has a critical impact on the adsorption of antibiotics in water. We investigated the contribution of OM content and form to the adsorption of tetracycline (TC) and norfloxacin (NOR) in the SPM of Taihu Lake. To change the content and form of OM in SPM, the samples were subjected to pyrolysis at 505 ˚C and oxidization with H2O2, respectively. Combustion almost completely removed OM, while oxidation removed most of the OM and transformed the remaining OM. Regardless of whether the OM changed or not, the adsorption of NOR and TC by SPM was more in line with the pseudo-second-order kinetic model instead of pseudo-first-order. The fitting of the intraparticle diffusion model showed that the removal of OM had a certain degree of change in the adsorption process. The isothermal adsorption of TC in all samples was more in line with the Temkin model. The isothermal adsorption of NOR in the oxidized sample conformed to the Temkin model, while it conformed to the Langmuir model in the original sample and the sample removed OM via combustion. The adsorption capacity of SPM with almost complete removal of OM significantly decreased, while conversely, the adsorption capacity of SPM after oxidation increased. This indicates that both the content and form of OM affect the adsorption of antibiotics by SPM, and the form of OM has a greater impact. The contribution of OM to NOR adsorption was greater than that of TC. In conclusion, the results verify the importance of OM in adsorbing antibiotics onto SPM, which may provide basic data for antibiotic migration in surface water.

Spatiotemporal distribution and ecological risk assessment of pharmaceuticals and personal care products (PPCPs) from Luoma Lake, an important node of the South-to-North Water Diversion Project.

PPCPs (pharmaceuticals and personal care products) are widely found in the environment and can be a risk to human and ecosystem health. In this study, spatiotemporal distribution, critical risk source identification and potential risks of 14 PPCPs found in water collected from sampling points in Luoma Lake and its inflowing rivers in two seasons in 2019 and 2020 were investigated. The PPCPs concentrations ranged from 27.64 ng·L-1 to 613.08 ng·L-1 in December 2019, and from 16.67 ng·L-1 to 3287.41 ng·L-1 in April 2020. Ketoprofen (KPF) dominated the PPCPs with mean concentrations of 125.85 ng·L-1 and 640.26 ng·L-1, respectively. Analysis of sources showed that the pollution in Luoma Lake mostly originated from sewage treatment plant effluents, inflowing rivers and domestic wastewater. Among them, the inflowing rivers contributed the most (82.95%) to the concentration of total PPCPs. The results of ecological risk assessment showed that there was a moderate risk (0.1 < RQs < 1) from carbamazepine (CBZ) in December 2019 and a high risk (RQs > 1) from naproxen (NPX) in April 2020. The results of human risk assessment found that NPX posed a high risk to infant health, and we found that NPX was associated with 83 diseases according to Comparative Toxicogenomics Database. NPX was identified as a substance requiring major attention. The results provide an understanding of the concentrations and ecological risks of PPCPs in Luoma Lake. We believe the data will support environmental departments to develop management strategies and prevent PPCPs pollution.

Carbon quantum dot-induced developmental toxicity in Daphnia magna involves disturbance of symbiotic microorganisms.

With the increasing synthesis and application of carbon quantum dots (CQDs), their prevalence as pollution in water environments has increased. However, the toxic effects of CQDs on aquatic organisms are unclear, and their environmental safety must be evaluated. Herein, Daphnia magna was used as a model organism to explore the developmental toxicity of CQDs under a full life-cycle exposure. It was found that the feeding rate and offing number of D. magna decreased with increasing CQD concentration, and the body length of D. magna showed a trend of first increasing and then decreasing. These results indicated that long-term exposure to CQDs has evident toxic effects on D. magna development. Symbiosis analysis showed that the composition of the symbiotic microbial community of D. magna was disturbed by CQDs. The abundance of microorganisms involved in the immune response of D. magna such as Rhodobacter, decreased; those involved in the inflammation such as Gemmobacter, increased; and those involved in the nitrogen cycle, such as Hydrogenophaga and Paracoccus, decreased. When D. magna was subjected to environmental pressure, host-microflora interactive immune regulation was induced. The abundance of probiotics in D. magna, such as Rhodococcus, increased in response to environmental pressure. The results of KEGG function prediction showed that the abundance of symbiotic microorganisms involved in energy absorption and metabolism was affected by CQDs. In addition, the correlation analysis showed that there was a correlation between the changes in the symbiotic microbial community and the damage to D. magna after exposure to CQDs. Thus, it is appealed that as a potential environmental pollutant, CQDs have aquatic environmental risks, and their safe application deserves attention.

Developmental toxicity in Daphnia magna induced by environmentally relevant concentrations of carbon black: From the perspective of metabolomics and symbiotic bacteria composition.

The level of carbon black (CB) pollution in the environment is rapidly increasing, owing to the increase in natural and industrial emissions. The water environment has become an important sink for CB. However, studies on CB mainly focused on its impact on air pollution and phytoremediation applications, and the toxicity mechanism of CB in aquatic organisms is relatively limited. Thus, Daphnia magna was used as a model organism to explore the developmental toxicity of environmentally relevant concentrations of CB under a full life-cycle exposure. The toxicity mechanism of CB in aquatic organisms was investigated based on metabolomic and symbiotic microbial analyses. It was found that compared with the control group, the body length of exposed D. magna decreased, while the mortality and intestinal inflammation increased with increasing concentration of CB. The normal reproductive regularity of D. magna was disturbed, and the deformity and body length of the offspring increased and decreased, respectively, after CB exposure. Metabolomic analysis showed that the urea cycle metabolic pathway of exposed D. magna was increased significantly, suggesting a perturbation of N metabolism. In addition, two eicosanoids were increased, suggesting possible inflammation in D. magna. The levels of seven phospholipid metabolites decreased that might be responsible for offspring malformations. Microbiological analysis showed that the composition of the symbiotic microbial community of D. magna was disturbed, including microorganisms involved in carbon cycling, nitrogen cycling, and biodegradation of pollutants, as well as pathogenic microorganisms. Overall, this study found that the inflammatory related metabolites and symbiotic bacterial, as well as reproductive related metabolites, were disrupted after D. magna exposed to different concentrations of CB, which revealed a possible developmental toxicity mechanism of CB in D. magna. These findings provide a scientific basis for analyzing the risks of CB in aquatic environments.

Peroxymonosulfate activation by nitrogen-doped herb residue biochar for the degradation of tetracycline.

Biochar is an environmentally friendly material with potential applications in water purification. In this study, herb residue nitrogen-doped biochar (N-BC) was fabricated and used to activate peroxymonosulfate (PMS). Characterization and density-functional theory (DFT) studies were conducted to explore the influence of nitrogen doping. Radical scavenging activity and electron paramagnetic resonance (EPR) spectroscopy revealed that non-radical singlet oxygen (1O2) is the main reactive oxidative species. Additionally, pyridinic-N was shown to play a pivotal role in the 1O2-dominated pathway. Three possible degradation pathways were proposed based on the identified degradation intermediates. Batch experiments confirmed that N-BC showed excellent catalytic performance and reusability. The best condition for tetracycline (TC) degradation efficiency (>99%) in 60 min was obtained when the dosage of N-BC was 1 g/L and the concentration of PMS was 5 mM. Furthermore, N-BC showed approximately 65.5% degradation efficiency within 4 cycles. Furthermore, the toxicity of degradation intermediates was examined using ECOSAR and T.E.S.T procedures. This study brings forth a feasible strategy to synthesize biochar. Furthermore, the proposed approach will facilitate the use of biochar in water purification.

Analysis of findings of ear, nose, and throat exam of some freshmen in military college entrance examination in Shandong Province / 中国学校卫生

Objective@#To analyze the ear, nose, and throat exam of some freshmen in the military college entrance examination in Shandong Province in 2020 and to facilitate adolescent targeted health promotion.@*Methods@#The 1 411 freshmen participating in the military college entrance examination in Jinan, Zibo and Weifang of Shandong Province were included. The ear, nose, and throat exam were performed by professionals using electric otoscope, 5 meter whispering test, and front rhinoscope.@*Results@#Nasal septal deviation and hypertrophy of inferior turbinate accounted for the highest proportion. Among 489 cases of nasal septum deviation, the detection rate of Jinan (15.97%) was significantly lower than that of Weifang (43.60%) and Zibo (46.53%) ( χ 2=63.32， P <0.05). For deviation of nasal septum, the detection rate in students with urban residence (31.53%) was significantly lower than that of rural students (39.03%) ( χ 2=4.11， P <0.05). Seventy two cases of inferior turbinate hyperplasia were detected, and the detection rate in Jinan (2.99%) was significantly lower than that in Weifang (6.51%) and Zibo (6.04%) ( χ 2=6.63， P <0.05). The detection rate of tonsil hypertrophy was significantly lower in boys (4.63%), students from urban area (3.94%), compared with that of girls(9.56%) and rural students (6.70%) ( χ 2=5.35，4.86， P <0.05). In pharyngeal examination, tonsil hyperplasia was the most common condition of enlarged tonsils ( n =214), which was significantly higher in Jinan(22.36%) than that of Weifang (11.71 %) and Zibo (10.74%) ( χ 2=22.39， P <0.05), and was significantly lower in boys (14.38%) and rural students (12.40%) than that in girls (22.79%) and urban students (17.24%) ( χ 2=4.70，4.65， P <0.05).@*Conclusion@#Nasal septum deviation and tonsil hypertrophy are the most prevalent upper airway diseases among freshmen participating in the military college entrance examination. Prevention and treatment of nasopharynx diseases should be emphasized.

A fungal cellulose nanocrystals-based approach to improve the stability of triterpenes loaded Pickering emulsion.

Depolysaccharide residues of edible fungus Pleurotus eryngii (dePSR-Pe), a mushroom industry waste, have abundant cellulose. In this study, the cellulose nanocrystals of P. eryngii (PeCNs) were extracted by hydrochloric acid. Results showed that the length of PeCNs is 469 ± 76.41 nm with a high aspect ratio of 40-100 and needle morphology. The structural characterization revealed that PeCNs had good thermal stability (approach 300 °C) and high crystallinity (84.2 %). An O/W Pickering emulsion stabilized with PeCNs was prepared to inhibit lipid oxidation and improve the loading capacity of triterpenes of P. coco. Unimodal size distribution of emulsion droplets was obtained under an optimized aqueous-phase condition to form a metastable emulsion, regardless of varying oil-water volume ratio <50/50. In vitro digestion study suggested that triterpenes-loaded Pickering emulsion had 1-3 times higher drug stability than bulk oil. These metastable Pickering emulsions call for fewer nanoparticles and provide a new strategy for the industry application of cellulose nanocrystals at less cost.

Trophic transfer and environmental safety of carbon dots from microalgae to Daphnia.

The application of carbon dots (CDs), a novel carbon nanomaterial, is extensive, leading to inevitable CD pollution. However, studies on their environmental fate and related risks to aquatic ecosystems are limited. Here, the trophic transfer of CDs from Chlorella pyrenoidosa to Daphnia magna and their toxic effects on the two organisms were analyzed. 14C-labelling was used to quantify and evaluate the fate of CDs. The results showed that the radioactivity of CDs in water was >80 % of the initial radioactivity, and that water extractable residues were dominant in organisms, with only 3 % or less recovered from the mineralization product 14CO2. The distribution of radioactivity illustrated how the exposure routes changed the fate of CDs in aquatic environments. CD aggregates were found in algal cells and Daphnia intestinal tract, indicating the cellular uptake of CDs in these aquatic organisms. Wall-membrane detachment, cell collapse, and rupture were observed in the ultrastructural investigations of microalgae, whereas pneumatosis cystoides intestinalis was observed in the ultrastructural investigations of D. magna. CD exposure affected the growth and chlorophyll content of C. pyrenoidosa as well as the feeding behavior, oxidative stress system, digestive system, and symbiotic bacteria of D. magna. The toxicity of CDs is also affected by the route of exposure. These findings suggest that dietary exposure to CDs was more likely to cause environmental risk and adverse effects than aqueous exposure, and the environmental risks associated with CDs should not be underestimated.

Combined toxicity and toxicity persistence of antidepressants citalopram and mirtazapine to zooplankton Daphnia magna.

Citalopram (CTP) and mirtazapine (MTP) are two typical psychoactive drugs used for the depression treatment. As emerging pollutants, CTP and MTP have raised concern because of their harmful effect on aquatic organisms. Therefore, the ecotoxicological risk of these two pollutants to aquatic organisms should be given more attention. In this study, the effects of CTP and MTP on the feeding rate, heartbeat, nutritional enzymes, and their related gene expression of D. magna were investigated under single and binary mixture pollutant exposure. Subsequently, the recovery of exposed D. magna was studied to assess the toxic persistence of those pollutants. After 24-h exposure, the ingestion rate decreased by 34.2% and 21.5%, in the group of 1.45 mg/L CTP (C-H) and binary mixture with high concentration (Mix-H), respectively. After 24-h recovery, the feeding rate of D. magna was stimulated by a compensatory response. Over the exposure period, the heartbeat rate of D. magna increased significantly in the groups of CTP, MTP, and their binary mixture with low concentration (Mix-L), and then, their heartbeat rate was recovered during the recovery period. The activity of α-amylase (AMS) and trypsin were significantly changed in most of the exposed daphnia, both during the exposure and recovery period. CTP/MTP exposure stimulated the expression of the AMS gene. MTP and Mix-H exposure inhibited the expression of the trypsin gene and the other groups stimulated its expression. After 24-h recovery, the stimulating or inhibitory effects were alleviated. There were different responses between gene expression and enzyme activity. In conclusion, our results highlighted the toxic effects at high concentrations of single and mixed pollution of CTP and MTP on the feeding rate, heartbeat, AMS and trypsin enzyme activity, and expression of related genes of D. magna to assess the environment risk of them.

Physicochemical properties and in vitro digestion behavior of a new bioactive Tremella fuciformis gum.

A new easy-dissolved Tremella fuciformis gum (TFG) from fruiting body was investigated in detail from three aspects: physicochemical characteristics, rheological behavior and in vitro digestion behavior. The results showed that TFG consisted of 73.9% polysaccharides, exhibiting easy solubility in water and good colloidal characteristics and stability. The physical and chemical treatments could decrease the apparent viscosity of TFG solution. The antioxidation activity of TFG remained constant at each static in vitro digestion phase, revealing that this gum could be used as a potential food thickener and antioxidant. The digestion behavior of TFG was also determined using a dynamic in vitro digestive system, DIVRS-II. The results demonstrated that the digestion behavior of TFG should be attributed to the morphology of digestive tracts, continuous secreting and continuous emptying. The antitussive effect of TFG was related to the increase in serum IL-10 content.

Synthesis of typical sulfonamide antibiotics with [14C]- and [13C]-labeling on the phenyl ring for use in environmental studies.

Background: Due to their widespread use, sulfonamide antibiotics (SAs) have become ubiquitous environmental contaminants and thus a cause of public concern. However, a complete understanding of the behavior of these pollutants in complex environmental systems has been hampered by the unavailability and high cost of isotopically labeled SAs. Results: Using commercially available uniformly [14C]- and [13C]-labeled aniline as starting materials, we synthesized [phenyl-ring-14C]- and [phenyl-ring-13C]-labeled sulfamethoxazole (SMX), sulfamonomethoxine (SMM), and sulfadiazine (SDZ) in four-step (via the condensation of labeled N-acetylsulfanilyl chloride and aminoheterocycles) or five-step (via the condensation of labeled N-acetylsulfonamide and chloroheterocycles) reactions, with good yields (5.0-22.5% and 28.1-54.1% for [14C]- and [13C]-labeled SAs, respectively) and high purities (> 98.0%). Conclusion: The synthesis of [14C]-labeled SAs in milligram amounts enables the preparation of labeled SAs with high specific radioactivity. The efficient and feasible methods described herein can be applied to the production of a variety of [14C]- or [13C]-labeled SAs for studies on their environmental behavior, including the fate, transformation, and bioaccumulation of these antibiotics in soils and aqueous systems. Supplementary Information: The online version contains supplementary material available at 10.1186/s12302-022-00598-z.

[Application of nasal nitric oxide in primary diffuse chronic rhinosinusitis].

Objective:This study aimed to investigate whether nasal nitric oxide（nNO） could be used to identify the main clinical phenotypes of primary diffuse chronic sinusitis（CRS） and reflect the severity of sinus mucosal lesions. Methods:A total of 57 patients with primary diffuse CRS were included as the case group in this study. And the patients were divided into eosinophilic CRS（EosCRS） group and non-EosCRS group according to the percentage of eosinophils in peripheral blood. At the same time, 32 healthy volunteers were selected as the control group. According to whether there is nasal polyps under nasal endoscopy, the EosCRS group was classified into EosCRS with nasal polyps（EosCRSwNP） and EosCRS without nasal polyps（EosCRSsNP）. In the same way, the non-EosCRS group was assigned to non-EosCRS with nasal polyps（non-EosCRSwNP） and non-EosCRS without nasal polyps（non-EosCRSsNP）. The levels of nNO were detected by single nostril air extraction with 10 mL/s flow rate and soft palate closure. The severity of sinus lesions were evaluated by Lund-Mackay score. The difference of nNO levels were compared by the Rank sum test. The correlation between nNO levels and Lund-Mackay score was analyzed by Pearson correlation analysis. Results:①The levels of nNO in EosCRS group [315.00（88.00, 446.50） ×10⁻9] and non-EosCRS group [419.00（181.00, 469.00） ×10⁻9] were significantly lower than those in the control group [457.00（431.00, 493.75） ×10⁻9]（P<0.01）. ②The levels of nNO in EosCRSwNP group [260.00（71.75, 391.50） ×10⁻9] were significantly lower than that in EosCRSsNP group [557.00（442.50, 619.75） ×10⁻9], and that in non-EosCRSwNP group [210.00（159.75, 434.25） ×10⁻9] were significantly lower than non-EosCRSsNP group [455.00（425.00, 481.00） ×10⁻9]（P<0.05）. ③There was a medially negative correlation between the levels of nNO and the total score of Lund-Mackay score in the EosCRS group（r=-0.567, P<0.01）. Conclusion:The levels of nNO can be used to determine whether primary diffuse CRS is accompanied by nasal polyps and reflect the severity of nasal sinus mucosal lesions, instead of identifying the main clinical phenotypes of primary diffuse CRS.

Psychoactive drugs citalopram and mirtazapine caused oxidative stress and damage of feeding behavior in Daphnia magna.

As the emerging contaminants, the environmental risks of drug-derived pollutants have attracted extensive attention. Citalopram (CTP) and mirtazapine (MTP) are commonly used as modern antidepressant drugs. Previous studies had proved that CTP and MTP entered the aquatic environment, but less reported the negative effects of the drugs on aquatic organisms. Herein, the effects on the feeding rate of Daphnia magna (D. magna) induced by psychotropic drugs CTP and MTP were investigated, which the possible mechanisms were analyzed with the oxidative stress and damage. Generally, the feeding rates of exposed D. magna under all concentrations of CTP and 1.03 mg/L of MTP were significantly decreased after exposure (p < 0.05 or p < 0.01). The inhibitory effect of CTP on the feeding rate of D. magna was time- and dose-dependent. The levels of reactive oxygen species (ROS) were particularly increased in D. magna after CTP and MTP exposure (p < 0.05 or p < 0.01). The level of antioxidant molecules glutathione S-transferase (GST) and the activity of scavenging enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) of D. magna were increased (p < 0.05 or p < 0.01). In consequence, the levels of malondialdehyde (MDA), protein carbonyl, and 8-hydroxydeoxyguanosine (8-OHdG) were increased (p < 0.05 or p < 0.01), which indicated oxidative damage caused by MTP and CTP, due to the imbalance of antioxidative stress system. These findings indicated that psychoactive drugs posed a high toxic threat to the aquatic organisms, and the aquatic environmental risks caused by using psychoactive drugs deserve more attention.