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In this study, a fiber-packed needle trap device (NTD) was developed by packing heat-resistant fibers with a polyethylene glycol sol-gel coating into a 21-gauge, stainless steel needle. The polyethylene glycol sol-gel coating has numerous advantages, including uniform roughness and a large specific surface area. The prepared NTD was used for headspace extraction of five polychlorinated biphenyls (PCBs) in water samples, determined by gas chromatography with a flame ionization detector (GC-FID). The main experimental parameters, including the extraction and desorption conditions, ionic strength, and fiber bundles, were investigated to improve the extraction efficiency. After optimization, satisfactory linearity (r > 0.99) in the concentration range of 0.02–500 μg/L was obtained, and the enrichment factor of NTD for the five PCBs was between 1150 and 9537 times. The limit of detection (S/N = 3) of five PCBs were measured in ranges of 0.0021–0.01 μg/L. Furthermore, the fiber-packed NTD has excellent durability, and can be reused for 60 cycles. After being stored at room temperature for three days, the storage ability of the NTD had a loss of PCBs less than 10%, and the relative standard deviation (RSD) was less than 10%. When analyzing the PCBs in real water samples, good accuracies (spiked recoveries were in the range of 92.19–98.56%) and precision (the RSD was lower than 12.8%) was obtained.

A method based on gas chromatography–mass spectrometry (GC–MS), coupled with magnetic solid-phase extraction (SPE) with multi-walled carbon-nanotube (MWCNT)-coated iron oxide (Fe3O4) as the adsorbent, was developed for analyzing four organophosphate esters in ambient water samples. The magnetic, MWCNT composites were prepared by hydrothermal synthesis and characterized with scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, and superconducting quantum interference device magnetometry (SQUID). The extraction and desorption conditions, such as adsorbent dosage, adsorption time, eluent type, and eluent volume, were studied. The adsorbent was used to extract analytes within 50 min. The limit of detection (LOD) was between 0.038–1 μg/L, and the limit of quantitation (LOQ) was between 0.10–3.59 μg/L. The method was applied to analyze organophosphate esters in environmental water samples. A 72.5–89.1% recovery was obtained by analyzing spiked samples with low-, medium-, and high-concentration analytes. The relative standard deviations (RSDs) were less than 10%. This method displayed better sensitivity and accuracy; therefore, it could be successfully used to detect organophosphate esters in environmental water samples.

An inorganic-biopolymers hybrid flocculant (PSAC-SA) was prepared by modifying sodium alginate onto polysilicate aluminum calcium (PSAC) through coordination between SA and Ca2+. The preparation conditions of PSAC-SA and the flocculation parameters that influence of the turbidity and color removal efficiency were investigated and optimized. The flocculation experiments results showed that the maximum turbidity and color removal could get 97.2% and 98.4% for kaolin-humic acid suspensions, respectively. The application of PSAC-SA for Songhua River treatment indicated that it had an excellent flocculation capacity in real water samples, and its flocculation efficiency was much better than that of individual flocculants (PSAC and SA). Moreover, the flocculation mechanisms were discussed in detailed, which indicated that the bridging effect and physical entrapment of solid particles played an important role in the flocculation process.

Objectives: To investigate the causal association between hypertension and primary open-angle glaucoma (POAG). Methods: The hypertension-associated genome-wide association study (GWAS) was from UK biobank (UKB), involving 463010 participants. The GWAS of POAG is obtained from FinnGene project involving 4433 cases and 210201 controls. All participants were of European ancestry. The inverse-variance weighted (IVW) method was used as the primary analysis method to estimate the causality of hypertension on POAG. Meanwhile, MR Egger, weighted median, Weighted Median estimation, calculation of Cochran Q statistics, MR-Egger intercept test, MR-PRESSO global test and leave-one-out analysis were performed to verify the efficiency and consistency of the results. Results: A total of 57 hypertension related single-nucleotide polymorphisms (SNPs) were strongly associated with POAG after excluding potential confounders (old age, diabetes, myopia) and harmonizing the variants. IVW results showed that the incidence of POAG in patients with hypertension was 5.372 times higher than that in the control group (OR: 6.372, 95% CI: 1.824-22.262, P = 0.004). The results of Weighted median (OR: 9.707, P = 0.017), Maximum likelihood (OR: 6.642, P = 0.003), Penalised weighted median (OR: 9.696, P = 0.013) verified the casual association between hypertension and POAG. And the results of heterogeneity analysis, egger intercept and MR-PRESSO global test further confirmed the reliability of the findings. Conclusions: A causal association was suggested between genetically increased hypertension and higher risk of POAG. Long-term cohort studies are expected to verify the impact of hypertension on POAG.

Retinal pigment epithelium (RPE) degeneration is a leading cause of blindness in retinal degenerative diseases, but the mechanism of RPE regional degeneration remains largely unknown. This study aims to investigate the sensitivity of RPE to sodium iodate (SI) injury in the dorsal and ventral visual fields in mice and analyze whether overlaying cone photoreceptors regulate the sensitivity of RPE to SI-induced damage.SI was used to induce RPE degeneration in mice. Hematoxylin-eosin staining, immunostaining, and TUNEL assay were used to evaluate retinal degeneration along the dorsal-ventral axis. Flat-mounted and sectional retinal immunostaining were used to analyze the distribution of cones along the dorsoventral axis in C57BL/6, albino, and 129 mice. Electroretinography was used to examine the retinal function.Dorsal-central RPE was more sensitive to SI-mediated injury along the dorsal-ventral axis in C57BL/6 mice. Compared with the ventral RPE, the dorsal-central RPE was dominantly covered by M cone photoreceptors in these mice. Interestingly, M cone photoreceptor degeneration was followed by dorsal RPE degeneration under a low dose of SI. Furthermore, the sensitivity of dorsal RPE to a low dose of SI was reduced in both albino and 129 mouse strains with dominant mixed cones instead of M cones in the dorsal visual field.These findings suggest that dorsal-central RPE is more sensitive to SI injury and that SI-induced RPE degeneration could be controlled by modifying the dominant overlying cone population in the mouse dorsal retina, thereby highlighting a potential role of M cones in RPE regional degeneration.

Background Oxidative stress is a common cause of neurodegeneration and plays a central role in retinal degenerative diseases. Heme oxygenase-1 (HMOX1) is a redox-regulated enzyme that is induced in neurodegenerative diseases and acts against oxidative stress but can also promote cell death, a phenomenon that is still unexplained in molecular terms. Here, we test whether HMOX1 has opposing effects during retinal degeneration and investigate the molecular mechanisms behind its pro-apoptotic role. Methods Basal and induced levels of HMOX1 in retinas are examined during light-induced retinal degeneration in mice. Light damage-independent HMOX1 induction at two different expression levels is achieved by intraocular injection of different doses of an adeno-associated virus vector expressing HMOX1. Activation of Müller glial cells, retinal morphology and photoreceptor cell death are examined using hematoxylin-eosin staining, TUNEL assays, immunostaining and retinal function are evaluated with electroretinograms. Downstream gene expression of HMOX1 is analyzed by RNA-seq, qPCR examination and western blotting. The role of one of these genes, the pro-apoptotic DNA damage inducible transcript 3 (Ddit3), is analyzed in a line of knockout mice. Results Light-induced retinal degeneration leads to photoreceptor degeneration and concomitant HMOX1 induction. HMOX1 expression at low levels before light exposure prevents photoreceptor degeneration but expression at high levels directly induces photoreceptor degeneration even without light stress. Photoreceptor degeneration following high level expression of HMOX1 is associated with a mislocalization of rhodopsin in photoreceptors and an increase in the expression of DDIT3. Genetic deletion of Ddit3 in knockout mice prevents photoreceptor cell degeneration normally resulting from high level HMOX1 expression. Conclusion The results reveal that the expression levels determine whether HMOX1 is protective or deleterious in the retina. Furthermore, in contrast to the protective low dose of HMOX1, the deleterious high dose is associated with induction of DDIT3 and endoplasmic reticulum stress as manifested, for instance, in rhodopsin mislocalization. Hence, future applications of HMOX1 or its regulated targets in gene therapy approaches should carefully consider expression levels in order to avoid potentially devastating effects.

Diagnosis of diabetic cataract (DC) in the early stage is of great significance for drug intervention and surgery circumvention for DC patients. However, the lack of reliable imaging tools greatly limits the diagnosis of early DC. In this context, a fluorescent probe BBPy for hypochlorous acid (HOCl) is presented based on the oxidation of phenothiazine. The probe displays apparent emission enhancement at 562 nm toward HOCl with high selectivity, superb sensitivity (detection limit: 12.6 nM), and rapid response (within seconds). Using the probe, the HOCl generation in diabetic human lens epithelial cells was monitored, as well as the HOCl down-regulation during antioxidant treatment. Therefore, it is proposed that HOCl can be a promising biomarker for DC and fluorescence imaging technique can be regarded as a candidate tool for DC diagnosis.

In this study, velvet-like carbon nitride (V-g-C

High-pressure technology can help us to obtain excellent materials. We have explored alkaline-earth-metal strontium nitrides under different pressures, theoretically. A variety of stable Sr–N structures were predicted by the structure searching method using CALYPSO code. Six new stoichiometries, SrN, Sr2N3, SrN2, SrN3, SrN4, and SrN5, were predicted. And our calculation proved that all these compounds were stable existing under ambient pressure up to 100 GPa. A rich variety of poly-nitrogen forms appeared in the newly predicted SrNx compounds, including four nitrogen polymerization forms: ranging from N2, N3, N4, and N5 molecules, to zig-zag nitrogen chains and extended chains connected by puckered “N6” rings. Significantly, the 1D extended polymeric chain of puckered “N6” rings was firstly identified in the P-SrN3 structure at 60 GPa. Another N-rich C2/c-SrN4 was stable only under the relatively high-pressure of 20 GPa, but this phase can be quenched under atmospheric pressure. The N-rich phase SrN5 maintained structural stability when the pressure reached 50–70 GPa. The delocalization of π electrons from N atoms was the principal cause for its metallicity in SrN5. In this paper, our calculated results indicated that the energetic poly-nitrides in alkaline-earth-metal nitrides can be obtained by the high-pressure method.

Glucose-derived carbon-decorated magnetic microspheres were synthesized by an easy hydrothermal carbonization method and used as a high-efficiency adsorbent to extract bisphenols in water and tea drinks. The as-prepared carbon-decorated magnetic microspheres had a well-defined core-shell structure with a shell thickness of about 5 nm. The microspheres possessed high saturation magnetization at 60.8 emu/g and excellent chemical stability in aqueous solution. The experimental parameters affecting the extraction efficiency, including extraction time, pH, adsorbent dosage, desorption solvents, desorption time, and solution volume were evaluated. Electrostatic and π-π interactions were the major driving forces during extraction. Overall, a new magnetic solid-phase extraction method of determining bisphenols was developed on the basis of as-prepared magnetic microspheres. The method had a wide linear range, low limits of detection (0.03-0.10 µg/L), and high recoveries (85.4-104.6%).

Retinopathy, owing to damage to the retina, often causes vision impairment, and the underlying molecular mechanisms are largely unknown. Using a gene targeting strategy, we generated mice with the essential gene Tubgcp4 knocked out. Homozygous mutation of Tubgcp4 resulted in early embryonic lethality due to abnormal spindle assembly caused by GCP4 (gamma-tubulin complex protein 4, encoded by Tubgcp4) depletion. Heterozygotes were viable through dosage compensation of one wild-type allele. However, haploinsufficiency of GCP4 affected the assembly of γ-TuRCs (γ-tubulin ring complexes) and disrupted autophagy homeostasis in retina, thus leading to photoreceptor degeneration and retinopathy. Notably, GCP4 exerted autophagy inhibition by competing with ATG3 for interaction with ATG7, thus interfering with lipidation of LC3B. Our findings justify dosage effects of essential genes that compensate for null alleles in viability of mutant mice and uncover dosage-dependent roles of GCP4 in embryo development and retinal homeostasis. These data have also clinical implications in genetic counseling on embryonic lethality and in development of potential therapeutic targets associated with retinopathy.

A fiber-packed in-tube extraction device was developed with heat-resistant fibers coated with molecularly imprinted polymer as adsorbent for concentration detection of volatile organic compounds (VOCs). The coated fibers were longitudinally packed into a filling chamber. The inner diameter of the filling chamber was 3 mm and its length was 2.5 cm. The filling chamber was connected to gas chromatography port by a stainless needle. The device was heated by an external heater consisting of the heating wire surrounded outside of the filling chamber to gasify the analytes in the adsorbent. The prepared fiber-packed in-tube extraction device was used to analyze benzene, toluene, ethylbenzene and o-xylene (BTEX) in gas sample coupled with gas chromatography. The result showed that the device had better permeability. The extraction time for 150 mL of gas sample was 1.2 min. The linear detection range, recovery, limit of detection (LOD) and limit of quantification (LOQ) were also evaluated for the promising method. The linear detection ranges for BTEX were all 1–300 μg L−1, with the correlation coefficients of greater than 0.9936. The LODs and LOQs of the analytes were in the range of 0.02–0.03 μg L−1 and 0.03–0.05 μg L−1, respectively. The recoveries of BTEX were 90.3%, 94.3%, 98.7% and 103.3%, respectively.

A novel needle extraction device packed with heat-resistant fibers coated with perhydroxy cucurbit[6]uril by sol–gel technology was first developed for the analysis of polycyclic aromatic hydrocarbons in actual water samples. Its performance was tested via purge and trap microextraction coupled with gas chromatography. The strong adsorption affinity between polycyclic aromatic hydrocarbons and (OH)12Q[6] was attributed to C–H···π interactions and π–π interactions. The parameters of the extraction device, such as extraction volume, extraction temperature, desorption time, ionic strength, and fiber number, were optimized. Under optimized conditions, the as-prepared extraction device showed good linearity within 0.5–1,500 µg L−1 with low detection limits (0.03–0.2 µg L−1). Moreover, the durability of the needle extraction device was excellent and can be used for 60 cycles. Furthermore, the loss rates of the coating fiber were less than 10% after storage for 3 days at room temperature, and the RSD was less than 6.4%.

The conversion of metal–organic frameworks (MOFs) to porous carbon has attracted extensive attention for developing multifunctional adsorbent materials. Herein, we demonstrated a facile method to prepare magnetic porous carbon via calcinating MIL-101(Fe) precursor loaded with glucose at 700°C in an N2 atmosphere. The obtained magnetic porous carbon (MPCG) contained plenty of oxygen-containing functional groups and exhibited an enlarged specific surface area (177.7 m2/g) compared with its precursor (41.2 m2/g). In addition, MPCG can be easily separated from the matrix by a magnet. Benefitting from these advantages, the magnetic porous carbon exhibited high affinity toward four synthetic organic dyes (amaranth, ponceau 4R, sunset yellow, and lemon yellow) in an aqueous solution. Moreover, the adsorbent can be applied to quantitatively detect synthetic organic dyes in drinks coupled with chromatography. A new magnetic solid-phase extraction method for dye analysis yielded reasonable linearity (r๥0.99), low limits of detection (0.047–0.076 μg/L), and good precision within the analyte concentration range of 0.25–50 μg/L.

A pseudotargeted metabolomics method based on gas chromatography-mass spectrometry (GC-MS) was developed for the analysis of fatty acids in rice. A total of 16 fatty acids were detected in rice. The method was used to identify the difference between fatty acid profiles in rice. The total intensity of the saturated and unsaturated fatty acids was used as the evaluation index. The effects of six extraction methods and four extraction solvents on the extraction efficiencies of the fatty acids were compared. The developed method was used to investigate the fatty acid profiles in five types of rice (Daohuaxiang, Jixing, Jinlangzi, Nongda, and Zhuangyuan). The fatty acid profile in Daohuaxiang rice was different from that in the other four species. The fatty acids in Jinlangzi and Nongda rice were markedly different, while those in Jixing and Jinlangzi rice were similar. The method is simple, stable and accurate, and it can provide basic data for the improvement of rice quality and nutritional value.

A composite flocculant (PSAS-CS) consisted of cationic starch (CS) and polyaluminum silicate (PSAS) was prepared and used for the flocculation of simulated water samples. The morphology and structure of PSAS-CS were characterized by X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. The effect of flocculation conditions such as the flocculant dosage and the simulated water pH were investigated. The turbidity and color removal rates could reach 97.79% and 98.07% at PSAS-CS dosage of 1.5 mL/L and the simulated water pH of 5–9. Furthermore, the flocculation efficiency of PSAS-CS was compared with PSAS, CS and the starch modified polyaluminum silicate at different dosage. The results indicated that PSAS-CS showed the highest flocculation efficiency due to its plentiful of positive charges and extended molecular chain. Moreover, the removal rate of PSAS-CS could remain 85% at a low dosage of 0.2 mL/L.

3D magnetic porous carbon (MPCK) was prepared using the metal-organic framework (MOF) MIL-100(Fe) as the carbon precursor by carbonisation and KOH activation strategies. Carbonisation and activation ensured that MPCK possessed excellent structural and thermal stability, strong magnetic responsiveness and high surface area. MPCK was used as an adsorbent for the magnetic solid-phase extraction of clenbuterol and ractopamine from mutton samples. The concentration levels of analytes were determined by ultra-high performance liquid chromatography-mass spectrometry. Under optimised extraction conditions, the peak area responded linearly to analytes over the concentration range from 0.05 μg L-1 to 40 μg L-1 (r ≥ 0.9972). The detection limits of clenbuterol and ractopamine were found to be 0.130 μg kg-1 and 0.150 μg kg-1, respectively. The satisfactory recoveries in mutton samples ranging from 95.64% to 114.65% indicated that 3D porous carbon is a promising adsorption material for the extraction of clenbuterol and ractopamine from complex biological matrixes.

Covalent organic frameworks (COFs) have arisen as one kind of devisable porous organic polymer that has attracted immense attention in catalytic applications. In this work, we prepared cost-effective imine-based COFs (COF-300, COF-LZU1 and CIN-1) via a reaction kettle operated in place of a traditional sealed Pyrex tube. Then, phosphomolybdic acid (PMA) and iron ions were immobilized on the COF supports by impregnation; the resulting frameworks were denoted as Fe/PMA@COFs (Fe/PMA@COF-LZU1, Fe/PMA@CIN-1 and Fe/PMA@COF-300). A series of characterization results demonstrated that the PMA and iron ions were uniformly dispersed on the surface/cavities of the COFs. The catalytic properties of the obtained Fe/PMA@COFs were investigated in the epoxidation of cyclooctene with H2O2 as the oxidant. The experimental results show that the Fe/PMA@CIN-1 composite can act as an efficient heterogeneous catalyst for the epoxidation of cyclooctene. The intramolecular charge transfer between the COFs and the dual sites (PMA and Fe ions), the spatial structure and the nitrogen content of the COFs played critical roles in dispersing and stabilizing the active species, which are closely connected with the activity and stability of the catalysts. A novel efficient heterogeneous catalyst for the epoxidation of olefins via a simple and cost-effective process is provided, and this experiment demonstrates the notable application prospects of the covalent organic skeleton as a catalyst support.

Photoreceptor cell degeneration is a major cause of blindness and a considerable health burden during aging but effective therapeutic or preventive strategies have not so far become commercially available. Here we show in mouse models that signaling through the tyrosine kinase receptor KIT protects photoreceptor cells against both light-induced and inherited retinal degeneration. Upon light damage, photoreceptor cells upregulate Kit ligand (KITL) and activate KIT signaling, which in turn induces nuclear accumulation of the transcription factor NRF2 and stimulates the expression of the antioxidant geneHmox1. Conversely, a viableKitmutation promotes light-induced photoreceptor damage, which is reversed by experimental expression ofHmox1. Furthermore, overexpression of KITL from a viral AAV8 vector prevents photoreceptor cell death and partially restores retinal function after light damage or in genetic models of human retinitis pigmentosa. Hence, application of KITL may provide a novel therapeutic avenue for prevention or treatment of retinal degenerative diseases.

This paper describes a novel method for label-free mercury(II) ion detection based on exonuclease III-induced target signal recycling amplification using double-stranded DNA templated copper nanoclusters. The synthesized DNA-Cu nanoclusters were used with exonuclease III loop amplification technology for ultra-high sensitivity detection of mercury(II) ions, which were detected by significantly decreased fluorescence intensity. Under the optimal experimental conditions, there was a clear linear relationship between Hg2+ concentration in the range of 0.04 to 8 nM and fluorescence intensity. The detection limit for Hg2+ was 4 pM. In addition, the interference of other metal ions on the mercury(II) ion detection was also studied. To confirm the application of the fluorescent sensor, it was applied to determine the concentrations of mercury(II) ions in tap water, and the results showed that the method can be used to detect mercury(II) ions in water samples successfully.

Layered double hydroxides (LDHs) and layered double oxides (LDOs) are desirable adsorption materials for printing and wastewater treatment owing to their outstanding anion exchange abilities, abundant active sites, and eco-friendly nature. In this study, a versatile LDO hybrid coated with carbon dots (CDs@MgAl-LDO) was constructed by modifying sodium dodecylbenzene sulfonate on the surface of MgAl-LDH as a carbon precursor, followed by ligand carbonization and hydrotalcite dehydration at 450 °C under N2 flow. CDs@MgAl-LDO displayed a hexagonal lamellar architecture with a plate lateral size of approximately 500 nm. It had a higher BET specific surface area (28.61 m2/g) than MgAl-LDO (11.48 m2/g). X-ray diffraction analysis revealed that CDs@MgAl-LDO maintained the “memory effect” of LDOs and could retrieve the original structure when dispersed in water. Moreover, the modified carbon dots change the intrinsically hydrophilic nature of LDOs and help to improve the affinity for organic contaminants, including both cationic and anionic dyes. The adsorption of dyes on CDs@MgAl-LDO followed a pseudo-second-order kinetic model with correlation coefficients (R2) ranging from 0.9901 to 0.9911 and exhibited Freundlich-type heterogeneous adsorption. It showed superior adsorption performance for three dyes, with the maximum adsorption capacity of 3628.9–5174.1 mg/g, thereby outperforming previously reported LDH-based adsorbents. This work developed a facile approach for preparing new carbon dots-LDH hybrids for the highly efficient removal of multiple dyes.

Alkaline-earth metal polynitrides can be used as a type of starting materials in the synthesis of polymeric nitrogen, which is used as a potential high-energy-density material. The structural evolutionary behaviors of nitrogen in CaN3 were studied at the pressure up to 100 GPa using a particle-swarm optimization structure search combining with density functional theory. Two new stable phases with P and C2/m space groups at the pressures of 26 and 60 GPa were identified for the first time. Throughout the stable pressure range, these two structures are semiconductors and consist of the N atoms in sp2-hybrid states. To the best of our knowledge, this is the first time an N6 chain is reported in case of alkaline-earth metal polynitrides. The stable polynitrogen compounds and polymeric nitrogen as high-energy-density materials have potential applications. The present results open a new possible avenue to synthesize high-energy-density polynitrogen.

A novel magnetic solid–phase extraction approach was proposed for extraction of potential residues of tetracyclines (TCs) in tap and river water samples, based on Fe3O4@SiO2@FeO magnetic nanocomposite. Characterized results showed that the received Fe3O4@SiO2@FeO had distinguished magnetism and core–shell structure. Modified FeO nanoparticles with an ∼5 nm size distribution were homogeneously dispersed on the surface of the silica shell. Owing to the strong surface affinity of Fe (II) toward TCs, the magnetic nanocomposite could be applied to efficiently extract three TCs antibiotics, namely, oxytetracycline, tetracycline and chlortetracycline from water samples. Several factors, such as sorbent amount, pH condition, adsorption and desorption time, desorption solvent, selectivity and sample volume, influencing the extraction performance of TCs were investigated and optimized. The developed method showed excellent linearity (R > 0.9992) in the range of 0.133–333 μg L−1, under optimized conditions. The limits of detection were between 0.027 and 0.107 μg L−1 for oxytetracycline, tetracycline and chlortetracycline, respectively. The feasibility of this method was evaluated by analysis of tap and river water samples. The recoveries at the spiked concentration levels ranged from 91.0% to 104.6% with favorable reproducibility (RSD

Multifunctional magnetic microspheres (Mag@ZnO–Co3O4) with bimetal oxide shell were synthesized via a facile method. The Mag@ZnO–Co3O4 composite was characterized through a vibrating sample magnetometer, N2 adsorption analysis, Fourier transform infrared spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy analyses. The structural analysis showed that the as-prepared microsphere possessed a mean diameter of 150 nm, a bimetal oxide shell thickness of ∼10.0 nm, and a magnetic core, which endowed it with good dispersibility, strong magnetism, and excellent adsorption property for oxytetracycline (OTC). Several experimental conditions, such as solution pH, adsorption time, OTC concentration, and ionic strength were systematically investigated. The Mag@ZnO–Co3O4 composite exhibited a fast adsorption rate, that is, the equilibrium was reached within 90 min, when the concentration of OTC was between 10 and 30 mg/L. The compos...

The structural phase transition, electronic properties, and bonding properties of antimony nitrides have been studied by using the first principles projector augmented wave method. The relationship between the formation enthalpy and the composition of the Sb–N system has been explored. The novel Sb2N3 with the Cmcm space group is stable in a narrow pressure range from 100 GPa to 120 GPa. Apart from the Sb2N3, two nitrogen-rich phases SbN2 and SbN4 were predicted. The SbN2 with the C2/m space group is stable at 12 GPa and then transforms to the high-pressure phase at 23 GPa. The nitrogen-rich SbN4 appears at 14 GPa then undergoes C2/m → P → P phase transitions, and the calculated pressures of the phase transitions are 31 and 60 GPa, respectively. The nitrogen-rich SbN2 and SbN4 have similar structural features. Both SbN2 and SbN4 can be seen as a sandwich structure composed of the Sb–N layers and N2 dimers. The pressure-induced phase transitions of SbN2 and SbN4 are accompanied by the electron transfer between the Sb–N layers and N2 dimers. Moreover, the nitrogen-rich SbN4 has a higher energy density of 2.42 kJ g−1 and is a potentially high energy density material.