Leveraging microalgae as a sustainable ingredient for meat analogues.

As the world's population and income levels continue to rise, there is a substantial increase in the demand for meat, which poses significant environmental challenges due to large-scale livestock production. This review explores the potential of microalgae as a sustainable protein source for meat analogues. The nutritional composition, functional properties, and environmental advantages of microalgae are analyzed. Additionally, current obstacles to large-scale microalgal food production are addressed, such as strain development, contamination risks, water usage, and downstream processing. The challenges associated with creating meat-like textures and flavors using techniques like extrusion and emulsion formation with microalgae are also examined. Lastly, considerations related to consumer acceptance, marketing, and regulation are summarized. By focusing on improvements in cultivation, structure, sensory attributes, and affordability, microalgae demonstrate promise as a transformative and eco-friendly protein source to enhance the next generation of meat alternatives.

Resveratrol, a novel inhibitor of fatty acid binding protein 5, inhibits cervical cancer metastasis by suppressing fatty acid transport into nucleus and downstream pathways.

BACKGROUND AND PURPOSE: Because of cervical cancer (CC) metastasis, the prognosis of diagnosed patients is poor. However, the molecular mechanisms and therapeutic approach for metastatic CC remain elusive. EXPERIMENTAL APPROACH: In this study, we first evaluated the effect of resveratrol (RSV) on CC cell migration and metastasis. Via an activity-based protein profiling (ABPP) approach, a photoaffinity probe of RSV (RSV-P) was synthesized, and the protein targets of RSV in HeLa cells were identified. Based on target information and subsequent in vivo and in vitro validation experiments, we finally elucidated the mechanism of RSV corresponding to its antimetastatic activity. KEY RESULTS: The results showed that RSV concentration-dependently suppressed CC cell migration and metastasis. A list of proteins was identified as the targets of RSV, through the ABPP approach with RSV-P, among which fatty acid binding protein 5 (FABP5) attracted our attention based on The Cancer Genome Atlas (TCGA) database analysis. Subsequent knockout and overexpression experiments confirmed that RSV directly interacted with FABP5 to inhibit fatty acid transport into the nucleus, thereby suppressing downstream matrix metalloproteinase-2 (MMP2) and matrix metalloproteinase-9 (MMP9) expression, thus inhibiting CC metastasis. CONCLUSIONS AND IMPLICATIONS: Our study confirmed the key role of FABP5 in CC metastasis and provided important target information for the design of therapeutic lead compounds for metastatic CC.

Hepatocyte TIPE2 is a fasting-induced Raf-1 inactivator that drives hepatic gluconeogenesis to maintain glucose homeostasis.

BACKGROUND: The liver regulates metabolic balance during fasting-feeding cycle. Hepatic adaptation to fasting is precisely modulated on multiple levels. Tumor necrosis factor-α-induced protein 8-like 2 (TIPE2) is a negative regulator of immunity that reduces several liver pathologies, but its physiological roles in hepatic metabolism are largely unknown. METHODS: TIPE2 expression was examined in mouse liver during fasting-feeding cycle. TIPE2-knockout mice, liver-specific TIPE2-knockout mice, liver-specific TIPE2-overexpressed mice were examined for fasting blood glucose and pyruvate tolerance test. Primary hepatocytes or liver tissues from these mice were evaluated for glucose production, lipid accumulation, gene expression and regulatory pathways. TIPE2 interaction with Raf-1 and TIPE2 transcription regulated by PPAR-α were examined using gene overexpression or knockdown, co-immunoprecipitation, western blot, luciferase reporter assay and DNA-protein binding assay. RESULTS: TIPE2 expression was upregulated in fasted mouse liver and starved hepatocytes, which was positively correlated with gluconeogenic genes. Liver-specific TIPE2 deficiency impaired blood glucose homeostasis and gluconeogenic capacity in mice upon fasting, while liver-specific TIPE2 overexpression elevated fasting blood glucose and hepatic gluconeogenesis in mice. In primary hepatocytes upon starvation, TIPE2 interacted with Raf-1 to accelerate its ubiquitination and degradation, resulting in ERK deactivation and FOXO1 maintenance to sustain gluconeogenesis. During prolonged fasting, hepatic TIPE2 deficiency caused aberrant activation of ERK-mTORC1 axis that increased hepatic lipid accumulation via lipogenesis. In hepatocytes upon starvation, PPAR-α bound with TIPE2 promoter and triggered its transcriptional expression. CONCLUSIONS: Hepatocyte TIPE2 is a PPAR-α-induced Raf-1 inactivator that sustains hepatic gluconeogenesis and prevents excessive hepatic lipid accumulation, playing beneficial roles in hepatocyte adaptation to fasting.

FGF21 alleviates adipose stem cell senescence via CD90 glycosylation-dependent glucose influx in remodeling healthy white adipose tissue.

The senescence of adipose stem cells (ASCs) impairs healthy adipose tissue remodeling, causing metabolic maladaptation to energy surplus. The intrinsic molecular pathways and potential therapy targets for ASC senescence are largely unclear. Here, we showed that visceral ASCs were prone to senescence that was caused by reactive oxygen species (ROS) overload, especially mitochondrial ROS. These senescent ASCs failed to sustain efficient glucose influx, pentose phosphate pathway (PPP) and redox homeostasis. We showed that CD90 silence restricted the glucose uptake by ASCs and thus disrupted their PPP and anti-oxidant system, resulting in ASC senescence. Notably, fibroblast growth factor 21 (FGF21) treatment significantly reduced the senescent phenotypes of ASCs by augmenting CD90 protein via glycosylation, which promoted glucose influx via the AKT-GLUT4 axis and therefore mitigated ROS overload. For diet-induced obese mice, chronic administration of low-dose FGF21 relieved their visceral white adipose tissue (VAT) dysfunction and systemic metabolic disorders. In particular, VAT homeostasis was restored in FGF21-treated obese mice, where ASC repertoire was markedly recovered, accompanied by CD90 elevation and anti-senescent phenotypes in these ASCs. Collectively, we reveal a molecular mechanism of ASC senescence by which CD90 downregulation interferes glucose influx into PPP and redox homeostasis. And we propose a FGF21-based strategy for healthy VAT remodeling, which targets CD90 glycosylation to correct ASC senescence and therefore combat obesity-related metabolic dysfunction.

Promoted dissipation and detoxification of atrazine by graphene oxide coexisting in water.

The herbicide atrazine (ATZ) has a detrimental effect on the health of aquatic ecosystems and has become a global concern in recent years. But the understanding of its persistence and potential toxicity under combined pollution, especially in the coexistence of other emerging pollutants, remains limited. In this work, the dissipation and transformation of ATZ in combination with graphene oxide (GO) in water were investigated. Results showed that dissipation rates of ATZ dramatically increased by 15-95% with half-lives shortened by 15-40% depending on initial concentrations of ATZ, and the products were mainly toxic chloro-dealkylated intermediates (deethylatrazine (DEA) and deisopropylatrazine (DIA)), but their contents were significantly lower under the coexistence of GO compared to ATZ alone. In the presence of GO, the nontoxic dechlorinated metabolite hydroxyatrazine (HYA) was detected earlier than 2-9 days, and ATZ transformation into HYA was increased by 6-18% during 21-day incubation periods. This study indicated that the coexistence of GO enhanced the dissipation and detoxification of ATZ. From a remediation standpoint, GO-induced hydrolytic dechlorination of ATZ can reduce its ecological toxicity. But the environmental risks of ATZ for aquatic ecosystem under the coexistence of GO should still be given the necessary prominence due to the potential hazard of ATZ adsorbed on GO and the predominant degradation products (DEA and DIA).

Effects of Graphene Oxide on the Growth and Photosynthesis of the Emergent Plant Iris pseudacorus.

The extensive applications of graphene oxide (GO) inevitably lead to entry into the natural aquatic environment. However, information on its toxicity to emergent plants is still lacking. In this study, an emergent plant, Iris pseudacorus, was exposed to GO (1, 20, 80, and 140 mg·L-1) under hydroponic conditions for 15 weeks. Changes in plant growth were assessed by analyzing plant biomass and photosynthetic pigment contents; the photosynthesis response was verified by measuring chlorophyll a fluorescence; and the nutrient levels of the plant were evaluated. Results showed that GO at 20-140 mg·L-1 significantly increased plant dry weight by 37-84% and photosynthetic pigment contents by 26-178%, and 80 mg·L-1 was the optimal concentration. PSII activity, adjustment capacities of electron transport in PSII, the grouping or energetic connectivity between PSII units, light energy conversion efficiency, photosynthesis performance indexes (by 11-51%), and contents of several nutrient elements (N, Fe, and Cu) were increased by 49-69%, 34-84%, and 11-38%, respectively. These findings indicate that GO can enhance plant growth by promoting plant photosynthesis performance and improving plant nutrient levels, and has great application potential in promoting the growth and development of this emergent plant as a phytoremediation agent.

[Mechanism of Qiwei Guibao Granules in treatment of premature ovarian failure based on proteomics].

In this study, the underlying mechanism of Qiwei Guibao Granules(QWGB) in the treatment of premature ovarian fai-lure(POF) was explored by the proteomics technique. Firstly, the POF model was induced in mice by intragastric administration of Tripterygium wilfordii glycosides solution at 50 mg·kg~(-1) for 14 days. Ten days prior to the end of the modeling, the estrous cycle of mice was observed every day to evaluate the success of modeling. From the 1st day after modeling, the POF model mice were treated with QWGB by gavage every day and the treatment lasted four weeks. On the 2nd day after the end of the experiment, blood was collected from the eyeballs and the serum was separated by centrifugation. The ovaries and uterus were collected and the adipose tissues were carefully stripped. The organ indexes of the ovaries and uterus of each group were calculated. The serum estrogen(E_2) level of mice in each group was detected by ELISA. Protein samples were extracted from ovarian tissues of mice, and the differential proteins before and after QWGB intervention and before and after modeling were analyzed by quantitative proteomics using tandem mass tags(TMT). As revealed by the analysis of differential proteins, QWGB could regulate 26 differentially expressed proteins related to the POF model induced by T. wilfordii glycosides, including S100A4, STAR, adrenodoxin oxidoreductase, XAF1, and PBXIP1. GO enrichment results showed that the 26 differential proteins were mainly enriched in biological processes and cellular components. The results of KEGG enrichment showed that those differential proteins were involved in signaling pathways such as completion and coalescence cascades, focal adhesion, arginine biosynthesis, and terpenoid backbone biosynthesis. The complement and coalescence cascades signaling pathway was presumably the target pathway of QWGB in the treatment of POF. In this study, the proteomics technique was used to screen the differential proteins of QWGB in the treatment of POF in mice induced by T. wilfordii glycosides, and they were mainly involved in immune regulation, apoptosis regulation, complement and coagulation cascade reactions, cholesterol metabolism, and steroid hormone production, which may be the main mechanisms of QWGB in the treatment of POF.

CX3CR1hi macrophages sustain metabolic adaptation by relieving adipose-derived stem cell senescence in visceral adipose tissue.

Adipose-derived stem cells (ASCs) drive healthy visceral adipose tissue (VAT) expansion via adipocyte hyperplasia. Obesity induces ASC senescence that causes VAT dysfunction and metabolic disorders. It is challenging to restrain this process by biological intervention, as mechanisms of controlling VAT ASC senescence remain unclear. We demonstrate that a population of CX3CR1hi macrophages is maintained in mouse VAT during short-term energy surplus, which sustains ASCs by restraining their senescence, driving adaptive VAT expansion and metabolic health. Long-term overnutrition induces diminishment of CX3CR1hi macrophages in mouse VAT accompanied by ASC senescence and exhaustion, while transferring CX3CR1hi macrophages restores ASC reservoir and triggers VAT beiging to alleviate the metabolic maladaptation. Mechanistically, visceral ASCs attract macrophages via MCP-1 and shape their CX3CR1hi phenotype via exosomes; these macrophages relieve ASC senescence by promoting the arginase1-eIF5A hypusination axis. These findings identify VAT CX3CR1hi macrophages as ASC supporters and unravel their therapeutic potential for metabolic maladaptation to obesity.

CgMYB1, an R2R3-MYB transcription factor, can alleviate abiotic stress in an annual halophyte Chenopodium glaucum.

MYB transcription factors (TFs) are important regulators of the stress response in plants. In the present study, we characterized the CgMYB1 gene in Chenopodium glaucum, a member of the R2R3-MYB TF family. CgMYB1 was located in the nucleus with an activating domain at the C terminus. The CgMYB1 gene could be induced by salt and cold stress in C. glaucum. Overexpressing CgMYB1 in Arabidopsis significantly enhanced salt and cold tolerance, probably by improving physiological performance and stress-related gene expression. Further analysis suggests that the positive response of CgMYB1 to abiotic stress may partially be attributed to the interaction between CgMYB1 and the CgbHLH001 promoter followed by activation of downstream stress-responsive genes, which mediates stress tolerance. Our findings should contribute to further understanding of the function of R2R3 MYB TF in response to abiotic stress.

Promoter activity and transcriptome analyses decipher functions of CgbHLH001 gene (Chenopodium glaucum L.) in response to abiotic stress.

BACKGROUND: Our previous studies revealed that CgbHLH001 transcription factor (TF) played an important role in abiotic stress tolerance, suggesting that its promoter was a potential target in response to stress signals. In addition, the regulatory mechanism of CgbHLH001 TF is still limited. RESULTS: In the present study, a 1512 bp of 5'-flanking sequence of CgbHLH001 gene was identified, and the sequence carried quite a few of cis-acting elements. The gene promoter displayed strong activity and was induced by multiple abiotic stress. A series of 5'-deletions of the promoter sequence resulted in a gradual decrease in its activity, especially, the 5' untranslated region (UTR) was necessary to drive promoter activity. Further, CgbHLH001 promoter drove its own gene overexpression ectopically at the transcriptional and translational levels, which in turn conferred the stress tolerance to transgenic Arabidopsis. Transcriptome analysis showed that salt stress induced a large number of genes involved in multiple biological regulatory processes. Differentially expressed genes (DEGs) that mediate phytohormone signal transduction and mitogen-activated protein kinase (MAPK) signaling pathway were widely induced and mostly upregulated under salt stress, and the transcription levels in PbHLH::bHLH-overexpressing transgenic lines were higher than that of 35S::bHLH overexpression. CONCLUSIONS: The CgbHLH001 promoter exhibited a positive response to abiotic stress and its 5' UTR sequence enhanced the regulation of gene expression to stress. A few important pathways and putative key genes involved in salt tolerance were identified, which can be used to elucidate the mechanism of salt tolerance and decipher the regulatory mechanism of promoters to develop an adaptation strategy for desert halophytes.

Sterility of Aedes albopictus by X-ray Irradiation as an Alternative to γ-ray Irradiation for the Sterile Insect Technique.

The mosquito Aedes albopictus can transmit various arboviral diseases, posing a severe threat to human health. As an environmentally friendly method, sterile insect technology (SIT) is considered an alternative to traditional methods such as chemical pesticides to control Ae. albopictus. In SIT, the sterility of male mosquitoes can be achieved by γ-ray or X-ray radiation. Compared with γ-rays, X-rays are easier to obtain, cheaper, and less harmful. However, there is a lack of comparative assessment of these two types of radiation for SIT under the same controlled conditions. Here, we compared the effects of X-ray and γ-ray radiation on the sterility of Ae. albopictus males under laboratory-controlled conditions. Neither type of radiation affected the number of eggs but significantly reduced the survival time and hatch rate. The same dose of γ-rays caused a higher sterility effect on males than X-rays but had a more significant impact on survival. However, X-rays could achieve the same sterility effect as γ-rays by increasing the radiation dose. For example, X-rays of 60 Gy induced 99% sterility, similar to γ-rays of 40 Gy. In the test of male mating competitiveness, the induced sterility and the male mating competitiveness index were also identical at the same release ratio (sterile males/fertile males). At a release ratio of 7:1, nearly 80% of eggs failed to hatch. Sterile males produced by X-ray and γ-ray radiation had similar male competitiveness in competition with field males. In conclusion, a higher dose of X-rays is required to achieve the same sterility effect, compared to γ-rays. When γ-rays are not readily available, high-dose X-rays can be used instead. This study provides data supporting the selection of more suitable radiation for the field release of sterile male mosquitoes.

A novel NADP(H)-dependent 3α-HSDH from the intestinal microbiome of Ursus thibetanus.

3α-HSDHs have a crucial role in the bioconversion of steroids, and have been widely applied in the detection of total bile acid (TBA). In this study, we report a novel NADP(H)-dependent 3α-HSDH (named Sc 3α-HSDH) cloned from the intestinal microbiome of Ursus thibetanus. Sc 3α-HSDH was solubly expressed in E. coli (BL21) as a recombinant glutathione-S-transferase (GST)-tagged protein and freed from its GST-fusion by cleavage using the PreScission protease. Sc 3α-HSDH is a new member of the short-chain dehydrogenases/reductase superfamily (SDRs) with a typical α/ß folding pattern, based on protein three-dimensional models predicted by AlphaFold. The best activity of Sc 3α-HSDH occurred at pH 8.5 and the temperature optima was 55 °C, indicating that Sc 3α-HSDH is not an extremozyme. The catalytic efficiencies (kcat/Km) of Sc 3α-HSDH catalyzing the oxidation reaction with the substrates, glycochenodeoxycholic acid (GCDCA) and glycoursodeoxycholic acid (GUDCA), were 183.617 and 34.458 s-1 mM-1, respectively. In addition, multiple metal ions can enhance the activity of Sc 3α-HSDH when used at concentrations ranging from 2 % to 42 %. The results also suggest that the metagenomic approach is an efficient method for identifying novel enzymes.

Expression and Functional Characterization of a Novel NAD(H)- dependent 3α-HSDH.

BACKGROUND: 3α-Hydroxysteroid dehydrogenase (3α-HSDH) reversibly catalyzes the oxidation of the C3-hydroxyl group of steroids, and has been used in clinical applications to detect serum total bile acid (TBA). In this study, A novel 3α-HSDH (called Sb 3α-HSDH) was expressed and characterized. METHODS: Plasmid pGEX-6p-1 was used for the expression of Sb 3α-HSDH in Escherichia coli (BL21), and activities were determined by recording the change in absorbance at 340 nm with/without adding of ions. A prediction of its three-dimensional structure was performed with AlphaFold. RESULTS: The substrate specificity test indicated that Sb 3α-HSDH is NAD(H)-dependent and has no activity with NADP(H). We also showed that Sb 3α-HSDH can catalyze the oxidation reaction of GCDCA and GUDCA with catalytic efficiencies (kcat/Km) of 29.060 and 45.839 s-1mM-1, respectively. The temperature dependence of catalysis suggests that Sb 3α-HSDH is a member of the mesophilic enzymes with its best activity at about 45 °C. The optimum pH of Sb 3α-HSDH was found to be between pH 8.0 and 9.0. The effect of ions, including K+, Mg2+, Na+, Cu2+, Mn2+, Fe2+, and Fe3+ on enzyme activity was evaluated and K+ and Mg2+ were found to enhance the activity of Sb 3α-HSDH by about 20% at concentrations of 200 mM and 50 mM, respectively. The well-conserved GIG motif, the active sites, and the Rossmann fold in the threedimensional structure indicate that Sb 3α-HSDH belongs to the "classical" type of SDR superfamily. CONCLUSION: We expressed and characterized a novel NAD(H)-dependent 3α-HSDH with typical threedimensional characteristics of the SDRs that exhibited substrate specificity to GCDCA and GUDCA.

Effects of Amendments and Indigenous Microorganisms on the Growth and Cd and Pb Uptake of Coriander (Coriandrum sativum L.) in Heavy Metal-Contaminated Soils.

Heavy metal (HM) contamination of soils is a worldwide problem with adverse consequences to the environment and human health. For the safe production of vegetables in contaminated soil, efficient soil amendments need to be applied such as nano-hydroxyapatite (n-HAP) and poly γ-glutamic acid (γ-PGA), which can mitigate heavy metal uptake and enhance crop yield. However, the combined effects of soil amendments and indigenous microorganisms (IMOs) on HMs immobilisation and accumulation by crops have received little attention. We established a pot experiment to investigate the effects of IMOs combined with n-HAP and γ-PGA on coriander (Coriandrum sativum L.) growth and its Cd and Pb uptake in two acidic soils contaminated with HMs. The study demonstrated that applying n-HAP, with and without IMOs, significantly increased shoot dry biomass and reduced plant Cd and Pb uptake and diethylenetriaminepentaacetic acid (DTPA) extractable Cd and Pb concentrations in most cases. However, γ-PGA, with and without IMOs, only reduced soil DTPA-extractable Pb concentrations in slightly contaminated soil with 0.29 mg/kg Cd and 50.9 mg/kg Pb. Regardless of amendments, IMOs independently increased shoot dry biomass and soil DTPA-extractable Cd concentrations in moderately contaminated soil with 1.08 mg/kg Cd and 100.0 mg/kg Pb. A synergistic effect was observed with a combined IMOs and n-HAP treatment, where DTPA-extractable Cd and Pb concentrations decreased in slightly contaminated soil compared with the independent IMOs and n-HAP treatments. The combined treatment of γ-PGA and IMOs substantially increased shoot dry biomass in moderately contaminated soil. These results indicate that solo n-HAP enhanced plant growth and soil Cd and Pb immobilisation, and mitigated Cd and Pb accumulation in shoots. However, the combination of n-HAP and IMOs was optimal for stabilising and reducing HMs' uptake and promoting plant growth in contaminated soil, suggesting its potential for safe crop production.

The mitochondrial unfolded protein response: A multitasking giant in the fight against human diseases.

Mitochondria, which serve as the energy factories of cells, are involved in cell differentiation, calcium homeostasis, amino acid and fatty acid metabolism and apoptosis. In response to environmental stresses, mitochondrial homeostasis is regulated at both the organelle and molecular levels to effectively maintain the number and function of mitochondria. The mitochondrial unfolded protein response (UPRmt) is an adaptive intracellular stress mechanism that responds to stress signals by promoting the transcription of genes encoding mitochondrial chaperones and proteases. The mechanism of the UPRmt in Caenorhabditis elegans (C. elegans) has been clarified over time, and the main regulatory factors include ATFS-1, UBL-5 and DVE-1. In mammals, the activation of the UPRmt involves eIF2α phosphorylation and the uORF-regulated expression of CHOP, ATF4 and ATF5. Several additional factors, such as SIRT3 and HSF1, are also involved in regulating the UPRmt. A deep and comprehensive exploration of the UPRmt can provide new directions and strategies for the treatment of human diseases, including aging, neurodegenerative diseases, cardiovascular diseases and diabetes. In this review, we mainly discuss the function of UPRmt, describe the regulatory mechanisms of UPRmt in C. elegans and mammals, and summarize the relationship between UPRmt and various human diseases.

Template-Free In Situ Encapsulation of Enzymes in Hollow Covalent Organic Framework Capsules for the Electrochemical Analysis of Biomarkers.

Although capsule-like materials as host carriers for enzyme encapsulation have been a hot topic in recent years, creating an ideal microenvironment for enhanced enzymatic performance is still a formidable challenge. Herein, we created a template-free method to in situ encapsulate natural enzymes in hollow covalent organic framework (COF) capsules at room temperature. The COF crystallites migrated from the inner core and self-assembled at the outside walls during the inside-out Ostwald ripening process, retaining the enzymes in the cavity. The adjustable hollow structure of the enzyme@COF capsule allowed the basic vibration of the enzyme to maintain a certain degree of freedom, thus significantly enhancing the enzymatic bioactivity. The hollow enzyme@COF capsule has large mesoporous tunnels allowing the efficient transport. In addition, the enzyme encapsulated in the capsule showed superior activity and ultrahigh stability under various extreme conditions that may lead to enzyme inactivation, such as high temperature, organic solvents, chelates, and the denaturing agent. Finally, the prepared hollow GOx@COF capsule was used for electrochemical sensing of glucose in human serum, and the electrochemical sensor exhibited high selectivity and satisfactory test results. This research not only provides a new way for COFs to encapsulate enzymes but also has potential applications in biocatalysis and biosensing, making artificial organelles possible.

Insertion of Hemin into Metal-Organic Frameworks: Mimicking Natural Peroxidase Microenvironment for the Rapid Ultrasensitive Detection of Uranium.

Constructing enzyme-like active sites in mimic enzyme systems is critical for achieving catalytic performances comparable to natural enzymes and can shed light on the natural development of enzymes. In this study, we described a specific hemin-based mimetic enzyme, which was facilely synthesized by the assembly of zeolitic imidazolate framework-l (ZIF-l) and hemin. The obtained hemin-based mimetic enzyme (denoted as ZIF-l-hemin) displayed enhanced peroxidase activity compared to free hemin in solution. Such excellent activity originated from the ZIF-l framework mimicking the active site cavity microenvironment of horseradish peroxidase in terms of axially coordinated histidine and distal histidine. Additionally, the constructed peroxidase mimetic was extremely resistant to a variety of severe circumstances that would normally denature natural enzymes. These characteristics made ZIF-l-hemin a potential platform for the colorimetric sensor of uranium (UO22+) with wide linear ranges (0.25-40 µM) and low limits of detection (0.079 µM). Moreover, the detection mechanism demonstrated that the coordination of uranyl ion with imidazole of ZIF-l-hemin reduced the catalytic efficiency of ZIF-l-hemin. The current work not only proposed a novel approach for fabricating artificial peroxidase but also offered facile colorimetric methods for selective radionuclide detection.

Room temperature fabrication of magnetic covalent organic frameworks for analyzing sulfonamide residues in animal-derived foods.

A magnetic solid phase extraction method based on magnetic covalent organic frameworks (TpBD@Fe3 O4 ; 2,4,6-triformylphloroglucinol (Tp) and benzidine (BD)) combined with high performance liquid chromatography has been developed to detect the sulfonamides including sulfadiazine, sulfamerazine, sulfamethazine, and sulfamethoxazole in milk and meat. TpBD@Fe3 O4 were synthesized at room temperature under mild reaction conditions with a simple and rapid operation. The TpBD@Fe3 O4 exhibited higher extraction efficiency because of the π-π and electrostatic interactions between the benzene ring structure of the TpBD and the sulfonamide molecules. The extraction conditions including the dosage of adsorbents, the type and dosage of eluent, the elution time, and the pH of the sample solution were fully optimized. The detection results showed good linearity over a wide range (50-5 × 104 ng/mL) and low detection limits (3.39-5.77 ng/mL) for the sulfonamide targets. The practicability of this magnetic solidphase extraction-high-performance liquid chromatography method was further evaluated by analyzing milk and meat samples, with recoveries of the targets of 71.6-110.8% in milk and 71.9-109.7% in pork. The successful detection of sulfonamides residues has demonstrated the TpBD@Fe3 O4 excellent practical potential for analyzing pharmaceutical residues in animal-derived foods.

A novel NAD(H)-dependent 3alpha-HSDH with enhanced activity by magnesium or manganese ions.

3α-Hydroxysteroid dehydrogenase (3α-HSDH) plays a crucial role in the metabolism of sex hormones and bile acids. In this study, we heterologously expressed and characterized a novel 3α-HSDH (named Sa 3α-HSDH). Substrate specificity tests showed that Sa 3α-HSDH could catalyze Glycochenodeoxycholic acid (GCDCA) and Glycoursodeoxycholic acid (GUDCA) with catalytic efficiency (kcat/Km) 40.815 and 14.616 s-1 mM-1, respectively. Sa 3α-HSDH is NAD(H) dependent according to the results of coenzyme screening, and one of mesophilic enzymes with optimum temperature 40 °C. Additionally, Sa 3α-HSDH displayed the highest activity at pH 8.5. In this study, effect of metal ions on activity was investigated, and the results showed Mn2+ (10 mM) and Mg2+ (50 mM) could significantly enhance the activity by nearly 140% and 100%, respectively. Fe2+, Cu2+, Fe3+ and K+ could enhance the activity of Sa 3α-HSDH at different levels. Meanwhile, Na+ only displayed activity-declining effect. The three-dimensional structure of Sa 3α-HSDH was predicted and displayed the well-conserved α/ß folding patterns (Rossman-fold) with a central ß-sheet. These results indicated that Sa 3α-HSDH would contribute to the quantitative determination of serum total bile acids and associated bioconversion.

High proportion strontium-doped micro-arc oxidation coatings enhance early osseointegration of titanium in osteoporosis by anti-oxidative stress pathway.

The excessive accumulation of reactive oxygen species (ROS) under osteoporosis precipitates a microenvironment with high levels of oxidative stress (OS). This could significantly interfere with the bioactivity of conventional titanium implants, impeding their early osseointegration with bone. We have prepared a series of strontium (Sr)-doped titanium implants via micro-arc oxidation (MAO) to verify their efficacy and differences in osteoinduction capabilities under normal and osteoporotic (high OS levels) conditions. Apart from the chemical composition, all groups exhibited similar physicochemical properties (morphology, roughness, crystal structure, and wettability). Among the groups, the low Sr group (Sr25%) was more conducive to osteogenesis under normal conditions. In contrast, by increasing the catalase (CAT)/superoxide dismutase (SOD) activity and decreasing ROS levels, the high Sr-doped samples (Sr75% and Sr100%) were superior to Sr25% in inducing osteogenic differentiation of MC3T3-E1 cells and the M2 phenotype polarization of RAW264.7 cells, thus enhancing early osseointegration. Furthermore, the results of both in vitro cell co-culture and in vivo studies also showed that the high Sr-doped samples (especially Sr100%) had positive effects on osteoimmunomodulation under the OS microenvironment. Ultimately, the collated findings indicated that the high proportion Sr-doped MAO coatings were more favorable for osteoporosis patients in implant restorations.