Clinical Manifestations and Genetic Analysis of 17 Patients with Autosomal Dominant Hyper-IgE Syndrome in Mainland China: New Reports and a Literature Review.

PURPOSE: Autosomal dominant hyper-IgE syndrome (AD-HIES) is a rare complicated primary immunodeficiency disease (PID). Signal transducer and activator of transcription 3 (STAT3) gene mutation is found to cause AD-HIES. The distribution of AD-HIES patients with STAT3 deficiency in the Chinese population is not clear. Herein, we retrospectively report 17 AD-HIES patients with STAT3 deficiency and demonstrate their clinical, immunological, and genetic features. METHODS: Patients' clinical data were collected from their medical records. Routine laboratory testing results included lymphocyte subset analysis and immunoglobulin quantification. STAT3 mutations were investigated by sequencing of genomic DNA. RESULTS: Among 575 patients with PID, 28 (4.87%) were clinically diagnosed as HIES. Among them, 17 (2.96%) were confirmed as STAT3 mutant AD-HIES. The ratio of male to female patients was 8:9. All of the 17 patients had NIH scores over 40 points. The mean ages at onset and diagnosis were 1.05 and 10.35 years, respectively. Three patients (17.65%, 3/17) died with a mean age of 13.33 years. Eczema, recurrent skin infection, and respiratory tract infection were the most common clinical symptoms and are present in all of the 17 patients in this study. Six patients (37.5%, 6/16) suffered complication from BCG vaccination. Noninfection symptoms are characteristic facial features in 17 patients (100%, 17/17), retention of primary teeth in 10 patients (90.91%, 10/11), and abnormal bone fractures in 7 patients (41.18%, 7/17). Eleven types of STAT3 mutations were identified in 17 patients, including 1 novel mutation. CONCLUSIONS: We here retrospectively report the largest Chinese cohort of AD-HIES patients with STAT3 mutation. Unique features, when compared to existing literature reports, include (1) later age of diagnosis, (2) significantly higher rate of BCG complications, and (3) lower rate of candidiasis and chronic otitis media.

Liposomes as a Novel Ocular Delivery System for Brinzolamide: In Vitro and In Vivo Studies.

The objective of this study was to investigate the potential of liposomes as an ophthalmic delivery system for brinzolamide (Brz) to enhance the local glaucomatous therapeutic effect. The liposomes of Brz (Brz-LPs) were produced by the thin-film dispersion method with a particle size of 84.33 ± 2.02 nm and an entrapment efficiency of 98.32 ± 1.61%. Differential scanning calorimetry (DSC) and X-ray powder diffraction (XRD) analysis proved that Brz was successfully entrapped into Brz-LPs. Brz-LPs displayed a biphasic release pattern in vitro with burst release initially and sustained release afterwards. The corneal permeability was measured using modified Franz-type diffusion cells, and Brz-LPs showed 6.2-fold increase in the apparent permeability coefficient when compared with the commercial available formulation (B rz-Sus). Moreover, Brz-LPs (1 mg/mL Brz) showed a more sustained and effective intraocular pressure reduction (5-10 mmHg) than Brz-Sus (10 mg/mL Brz) in white New Zealand rabbits. Therefore, Brz-LPs were a hopeful formulation of Brz for glaucoma treatment and worthy of further investigation.

High sensitivity nanoparticle detection using optical microcavities.

We demonstrate a highly sensitive nanoparticle and virus detection method by using a thermal-stabilized reference interferometer in conjunction with an ultrahigh-Q microcavity. Sensitivity is sufficient to resolve shifts caused by binding of individual nanobeads in solution down to a record radius of 12.5 nm, a size approaching that of single protein molecules. A histogram of wavelength shift versus nanoparticle radius shows that particle size can be inferred from shift maxima. Additionally, the signal-to-noise ratio for detection of Influenza A virus is enhanced to 381 from the previously reported 31. The method does not use feedback stabilization of the probe laser. It is also observed that the conjunction of particle-induced backscatter and optical-path-induced shifts can be used to enhance detection signal-to-noise.

The Impact of Molar Incisor Hypomineralisation on Children and Adolescents: A Narrative Review.

Molar incisor hypomineralisation (MIH) is a qualitative developmental enamel defect with a prevalence of 13% worldwide. This review aims to outline the current evidence regarding the impact of MIH on children's oral health and, more broadly, their day-to-day activities. MIH is associated with negative sequelae, including hypersensitivity, post-eruptive breakdown, the rapid development of carious lesions and poor aesthetics. Other concerns pertain to the clinical management of MIH and include difficulty in achieving local anaesthesia, increased dental fear and anxiety (DFA) and increased behaviour management problems. Oral health-related quality of life (OHRQoL) is the most standardised measure of patient impact; however, no instruments have been validated for use in MIH populations. The few existing observational studies investigating the impact of MIH on OHRQoL in children have produced conflicting results. Interventions to alleviate hypersensitivity and improve aesthetics had a positive impact on the OHRQoL of MIH-affected children. Multiple methodological issues make it difficult to measure the impact of MIH, including heterogeneity in the MIH severity classification, an overlap in the indices used to diagnose dental caries and MIH as well as the subjectivity of outcome measures for hypersensitivity and DFA.

Diagnostic agreement between visual examination and an automated scanner system with fluorescence for detecting and classifying occlusal carious lesions in primary teeth.

OBJECTIVES: To investigate the in vivo diagnostic agreement between visual examination (VE) using the International Caries Detection and Assessment System (ICDAS) and an automated scanner system for detecting and classifying carious lesions in primary teeth. METHODS: 5-year-old children (n = 216) underwent VE and intraoral scanning (TRIOS 4, 3Shape TRIOS A/S, Copenhagen, Denmark). Dental caries experience was recorded for each tooth surface using ICDAS. An automated, fluorescence-based caries scoring system was applied to eligible primary teeth occlusal surfaces on the 3D models using commercially available software. The automated system classified surfaces as sound, initial caries (ICDAS 01/02), or moderate-extensive caries (ICDAS ≥03). The diagnostic agreement was investigated using multi-level modelling and intraclass correlation coefficients. Analyses were repeated at both the initial threshold (ICDAS ≥01) and the moderate-extensive threshold (ICDAS ≥03). RESULTS: 213 participants were included in the study, and 1525 primary molar occlusal surfaces were included in the analysis. The odds of detecting caries using the automated system were 46 % lower at the initial disease threshold (OR 0.54, 95 % CI 0.39-0.74) and 70 % lower at the moderate-extensive disease threshold (OR 0.30, 95 % CI 0.16-0.58) compared to VE. The intraclass correlation estimates at the initial and moderate-extensive thresholds were 0.90 (95 % CI 0.70-0.96) and 0.76 (95 % CI 0.22-0.94) respectively. CONCLUSION: The automated system is less likely to detect initial lesions and is more likely to underestimate lesion severity relative to visual examination using ICDAS. CLINICAL SIGNIFICANCE: Clinically, using the automated tool to replace thorough visual inspection in primary teeth could result in missed opportunities to provide professional or self-care to arrest or reverse early disease. Additionally, it could misclassify moderate lesions as initial caries, potentially leading to complications associated with the delayed management of dental caries.

Temporal dynamics of lignin degradation in Quercus acutissima sawdust during Ganoderma lucidum cultivation.

Despite a fair amount of lignin conversion during mycelial growth, previous structural analyses have not yet revealed how lignin changes continuously and what the relationship is between lignin and ligninolytic enzymes. To clarify these aspects, Quercus acutissima sawdust attaching Ganoderma lucidum mycelium collected from different growth stage was subjected to analysis of lignin structure and ligninolytic enzyme activity. Two key periods of lignin degradation are found during the cultivation of G. lucidum: hypha rapid growth period and primordium formation period. In the first stage, laccase activity is associated with the opening of structures such as methoxyls, ß-O-4' substructures and guaiacyl units in lignin, as well as the shortening of lignin chains. Manganese peroxidases and lignin peroxidases are more suitable for degrading short chain lignin. The structure of phenylcoumarans and syringyl changes greatly in the second stage. The results from sawdust attaching mycelium provide new insights to help improve the cultivation substrate formulation of G. lucidum and understand biomass valorization better.

Nanoemulsion based lipid nanoparticles for effective demethylcantharidin delivery to cure liver cancer.

Demethylcantharidin (DEM) is a widely used antitumor drug; however, its poor tumor targeting and serious organotoxicity limit its application. The aim of this study was to develop a new drug delivery system for efficient delivery of DEM. Nanoemulsion based lipid nanoparticles containing demethylcantharidin (DNLNs) were prepared by loading nanoemulsions into lipid nanoparticles. The cells proliferation, apoptosis, cycle, and uptake were investigated by Cell counting kit-8 (CCK-8), flow cytometry, and in situ fluorescence assays, respectively. Then, we established the H22 tumor-bearing mouse model to evaluate the antitumor efficacy of DNLNs and further studied its organ toxicity and distribution. DNLNs significantly inhibited the proliferation and promoted apoptosis of H22 cells, and H22 cells could take up more DNLNs. Compared with DEM, DNLNs had certain tumor-targeting properties, and the tumor inhibition rate increased by 23.24%. Moreover, DNLNs can increase white blood cell count and reduce organ toxicity. This study paves the way for nanoemulsion-based lipid nanoparticle (NLNs)-efficient DEM delivery to treat liver cancer.

Caries Detection in Primary Teeth Using Intraoral Scanners Featuring Fluorescence: Protocol for a Diagnostic Agreement Study.

BACKGROUND: Digital methods that enable early caries identification can streamline data collection in research and optimize dental examinations for young children. Intraoral scanners are devices used for creating 3D models of teeth in dentistry and are being rapidly adopted into clinical workflows. Integrating fluorescence technology into scanner hardware can support early caries detection. However, the performance of caries detection methods using 3D models featuring color and fluorescence in primary teeth is unknown. OBJECTIVE: This study aims to assess the diagnostic agreement between visual examination (VE), on-screen assessment of 3D models in approximate natural colors with and without fluorescence, and application of an automated caries scoring system to the 3D models with fluorescence for caries detection in primary teeth. METHODS: The study sample will be drawn from eligible participants in a randomized controlled trial at the Royal Children's Hospital, Melbourne, Australia, where a dental assessment was conducted, including VE using the International Caries Detection and Assessment System (ICDAS) and intraoral scan using the TRIOS 4 (3Shape TRIOS A/S). Participant clinical records will be collected, and all records meeting eligibility criteria will be subject to an on-screen assessment of 3D models by 4 dental practitioners. First, all primary tooth surfaces will be examined for caries based on 3D geometry and color, using a merged ICDAS index. Second, the on-screen assessment of 3D models will include fluorescence, where caries will be classified using a merged ICDAS index that has been modified to incorporate fluorescence criteria. After 4 weeks, all examiners will repeat the on-screen assessment for all 3D models. Finally, an automated caries scoring system will be used to classify caries on primary occlusal surfaces. The agreement in the total number of caries detected per person between methods will be assessed using a Bland-Altman analysis and intraclass correlation coefficients. At a tooth surface level, agreement between methods will be estimated using multilevel models to account for the clustering of dental data. RESULTS: Automated caries scoring of 3D models was completed as of October 2023, with the publication of results expected by July 2024. On-screen assessment has commenced, with the expected completion of scoring and data analysis by March 2024. Results will be disseminated by the end of 2024. CONCLUSIONS: The study outcomes may inform new practices that use digital models to facilitate dental assessments. Novel approaches that enable remote dental examination without compromising the accuracy of VE have wide applications in the research environment, clinical practice, and the provision of teledentistry. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12622001237774; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=384632. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/51578.

Manipulating microRNA miR408 enhances both biomass yield and saccharification efficiency in poplar.

The conversion of lignocellulosic feedstocks to fermentable sugar for biofuel production is inefficient, and most strategies to enhance efficiency directly target lignin biosynthesis, with associated negative growth impacts. Here we demonstrate, for both laboratory- and field-grown plants, that expression of Pag-miR408 in poplar (Populus alba × P. glandulosa) significantly enhances saccharification, with no requirement for acid-pretreatment, while promoting plant growth. The overexpression plants show increased accessibility of cell walls to cellulase and scaffoldin cellulose-binding modules. Conversely, Pag-miR408 loss-of-function poplar shows decreased cell wall accessibility. Overexpression of Pag-miR408 targets three Pag-LACCASES, delays lignification, and modestly reduces lignin content, S/G ratio and degree of lignin polymerization. Meanwhile, the LACCASE loss of function mutants exhibit significantly increased growth and cell wall accessibility in xylem. Our study shows how Pag-miR408 regulates lignification and secondary growth, and suggest an effective approach towards enhancing biomass yield and saccharification efficiency in a major bioenergy crop.

Low-pump-power, low-phase-noise, and microwave to millimeter-wave repetition rate operation in microcombs.

Microresonator-based frequency combs (microcombs or Kerr combs) can potentially miniaturize the numerous applications of conventional frequency combs. A priority is the realization of broadband (ideally octave spanning) spectra at detectable repetition rates for comb self-referencing. However, access to these rates involves pumping larger mode volumes and hence higher threshold powers. Moreover, threshold power sets both the scale for power per comb tooth and also the optical pump. Along these lines, it is shown that a class of resonators having surface-loss-limited Q factors can operate over a wide range of repetition rates with minimal variation in threshold power. A new, surface-loss-limited resonator illustrates the idea. Comb generation on mode spacings ranging from 2.6 to 220 GHz with overall low threshold power (as low as 1 mW) is demonstrated. A record number of comb lines for a microcomb (around 1900) is also observed with pump power of 200 mW. The ability to engineer a wide range of repetition rates with these devices is also used to investigate a recently observed mechanism in microcombs associated with dispersion of subcomb offset frequencies. We observe high-coherence phase locking in cases where these offset frequencies are small enough so as to be tuned into coincidence. In these cases, a record-low microcomb phase noise is reported at a level comparable to an open-loop, high-performance microwave oscillator.

Effect of chlorine sanitizer on metabolic responses of Escherichia coli biofilms "big six" during cross-contamination from abiotic surface to sponge cake.

The effect of chlorine on Escherichia coli biofilm O157:H7 are well established; however, the effect on biofilm adhesion to food as well as the six emerging E. coli serotypes ("big six") have not been fully understood. Chlorine sanitization with 1-min 100 mg/L was applied against seven pathogenic E. coli (O111, O121:H19, O45:H2, O26:H11, O103:H11, O145, and O157:H7) biofilms on high-density polyethylene (HDPE) and stainless steel (SS) coupons, respectively. Using sponge cake as a food model, the adhesion behavior was evaluated by comparison of bacteria transfer rate before and after treatment. Besides, the metabolic profiles of biofilms were analyzed by nuclear magnetic resonance (NMR) spectrometer. A significant decrease in transfer rate (79% decline on SS and 33% decline on HDPE) was recorded as well as the distinctive pattern between SS and HDPE coupons was also noticed, with a low population (6-7 log CFU/coupon) attached and low survivals (0-3 log CFU/coupon) upon chlorine on SS, while high population (7-8 log CFU/coupon) attached and high survivals (5-7 log CFU/coupon) on HDPE. Moreover, O121:H19 and O26:H11 demonstrated the highest resistance to chlorine with the least metabolic status and pathways affected. O103:H11, O145, and O111 followed similar metabolic patterns on both surfaces. Distinct metabolic patterns were found in O45:H2 and O157:H7, where the former had more affected metabolic status and pathways on SS but less on HDPE, whereas the latter showed an opposite trend. Overall, a potential contamination source of STEC infection in flour products was demonstrated and metabolic changes induced by chlorine were revealed by NMR-based metabolomics, which provides insights to avoid "big six" biofilms contamination in food.

Preparation and characterization of two novel osteoinductive fishbone-derived biphasic calcium phosphate bone graft substitutes.

Many studies have reported on the conversion of natural resources into xenografts with hydroxyapatite (HA) as major component, but the extraction of biphasic calcium phosphate (HA/ß-TCP) from animal bones and transformation into bone graft substitutes are rarely reported. In this research, two kinds of fish bones were made into granular porous biphasic calcium phosphate bone graft substitutes with particle sizes between 500 to 1000 µm through a series of preparation procedures (Salmo salar calcined at 900°C named Sa900 and Anoplopoma fimbria calcined at 800°C named An800). The chemical composition was characterized by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The morphology and porous structure of the scaffolds were comparatively analyzed by scanning electron microscopy (SEM) and mercury porosimeter. The specific surface area of materials was measured by the nitrogen adsorption technique based on BET theory. Cytotoxicity and ectopic osteogenesis were also carried out to investigate the biocompatibility and osteoinductive potential of these materials. The results showed that both fishbone-derived scaffolds were composed of HA and ß-TCP with different proportions, and numerous interconnected pores with different sizes were observed at the surface of materials. An800 had higher total porosity reaching 74.8% with higher interconnectivity and micropores mostly distributed at 0.27 µm and 0.12 µm, while Sa900 had a higher specific surface area and higher intraparticle porosity with nanopores mostly distributed at 0.07 µm. CCK-8 assays and Live/dead staining demonstrated excellent biocompatibility. Material-induced osteoid formation were observed on the interface of both internal pores and periphery of materials after implantation in muscle pouch of Wistar rats for 8 weeks which indicated some extent of osteoinductive potential of materials. The possible mechanism of material-induced osteogenesis and the effects of chemical composition, surface topography, and spatial structure on osteogenesis were also discussed in this paper.

Sprayable hydrogel for biomedical applications.

Polymeric hydrogels have extraordinary potential to be utilized for biomedical applications. Recently, sprayable hydrogels have received increasing attention for their biocompatibility, degradability, tunable mechanical properties and rapid spray-filming abilities. In this review, hydrogel-based biomaterials, especially those based on natural polymers, such as polysaccharides and proteins, have been explained. The focus of this review lies on illuminating recent advances in sprayable hydrogel systems and highlighting the properties and applications of sprayable hydrogels, such as wound management, postoperative adhesion and cancer therapeutics. In addition, future research directions and challenges are also discussed.

Microbial succession and degradation during kitchen waste biodrying, highlighting the thermophilic phase.

Biodrying in conjunction with compound stone amendment was used to treat kitchen waste, which improved biodrying. After 16 days, the pile moisture content decreased from 68.8% to 23.0%. Lignin, cellulose and hemicellulose concentrations decreased from 104.6 mg g-1 d.b., 322.9 mg g-1 d.b. and 155.9 mg g-1 d.b., respectively, to 74.0 mg g-1 d.b., 224.8 mg g-1 d.b. and 134.5 mg g-1 d.b., respectively. The Shannon index for bacteria increased from 2.5 to 3.1, while for fungi, it decreased from 4.6 to 0.6. The relative abundances of Amino Acid Metabolism and Carbohydrate Metabolism exceeded 7%. The thermophilic phase during the process inactivated the pathogenic microorganisms, increased the bacterial diversity, decreased the fungal diversity, and potentially improved the metabolism of nutrients, including amino acids, carbohydrates, lipids and vitamins. The biomarker analysis and predicated protein sequences provide genetic evidence to elucidate why the thermophilic phase is the peak time for nutrient metabolism.

PCDD/Fs characteristics in flue gas and surrounding environment of iron and steel smelting industry.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations and distributions, emission factors and amounts, and ambient air and soil potential sources were investigated by collecting flue gas, ambient air, and soil samples from ten sintering furnaces and two electric arc furnaces of eight iron and steel smelting industries (ISSI) in China. In flue gas, the concentrations of PCDD/Fs ranged from 0.05 to 2.93 ng I-TEQ Nm-3 (mass, from 0.38 to 30.67 ng Nm-3), with an average of 0.42 ng I-TEQ Nm-3 (mass, 4.99 ng Nm-3), respectively. In ambient air, the concentrations ranged from 0.05 to 0.35 pg I-TEQ m-3 (mass, from 0.66 to 5.66 pg m-3), with an average of 0.20 pg I-TEQ m-3 (mass, 2.96 pg m-3), respectively. In surface soil, the concentrations ranged from 1.80 to 21.02 ng I-TEQ kg-1 (mass, from 34.29 to 836.00 ng kg-1), with an average of 5.82 ng I-TEQ kg-1 (mass, 252.10 ng kg-1), respectively. In deep soil, the concentrations ranged from 1.17 to 12.00 ng I-TEQ kg-1 (mass, from 56.83 to 1488.00 ng kg-1), with an average of 7.76 ng I-TEQ kg-1 (mass, 433.20 ng kg-1), respectively. Compared with emission limits for PCDD/Fs, the compliance was 78.9% in flue gas, 100% in ambient air, and 77.3% in soil. In congener profiles, the contributions of PCDFs were much higher than those of PCDDs in flue gas and ambient air, but the opposite was observed in soil. In ten sintering furnaces, the emission factors ranged from 22.11 to 901.22 ng I-TEQ t-1, with an average of 373.80 ng I-TEQ t-1, respectively. In two electric arc furnaces, the emission factors were 1667.52 and 894.96 ng I-TEQ t-1, with an average of 1281.24 ng I-TEQ t-1. According to both principal component analysis and hierarchical cluster analysis, all ambient air samples were affected by the emissions of PCDD/Fs from ISSIs, but to different degrees. However, the concentrations of PCDD/Fs in most soil samples were not influenced by the ISSI emissions.

Influence of chemical treatment and drying method on the properties of cellulose fibers of luffa sponge.

The exploration of modified luffa sponge (LS) cellulose fiber in the field of polymer composite can contribute to the development of high-performance and lightweight composites. In this study, two chemical treatments (10%NaOH-20%CH3COOH (Method 1) and 10%NaOH-5%Na2SO3 (Method 2)) and two drying methods (air drying and freeze-drying) were used to treat LS. The microscopic characteristics and physical properties showed that Methods 1 and 2 caused shrinkage of the LS fibers and increased their fiber density by 30.6% and 15.0%. Meanwhile, freeze-drying kept the cells of modified LS fibers full and decreased their fiber density by 5.0% and 21.0%, respectively. The tensile properties test analyses indicated that freeze-drying further increased the elongation at break values of modified LS fibers by 25.3% and 17.7%, respectively. The moisture absorption analyses showed that freeze-drying could further decrease the moisture absorption ratios of modified LS fibers by 25.8% and 35.8%, respectively, which was useful for improving the dimensional stability of composite materials. Moreover, the thermogravimetric analysis reveals that freeze-drying increased onset degradation temperatures of the modified fibers by 24.0 °C and 6.7 °C, which was beneficial to improve the thermal stability of the composite material.

Poly(styrene-alt-maleic anhydride) derivatives as potent anti-HIV microbicide candidates.

Topical microbicides offer women the opportunity to protect themselves from sexual HIV transmission under their own control. A series of poly[styrene-alt-(maleic anhydride)] derivatives were prepared by amidation or hydrolysis of the anhydride moiety. The derivatives were shown to be of low cell toxicity and effectively inhibited HIV-1 infections in an in vitro cellular model. Poly[styrene-alt-(maleic acid, sodium salt)] was the most potent inhibitor, being 100-fold more potent than dextran sulfate suggesting its potential application as a new class of polyanionic microbicides.

[Therapeutic effect and toxicity of compound vincristine liposome on breast cancer in nude mice].

This study was intended to assess the therapeutic effect and toxicity of Compound vincristine liposome on breast cancer in nude mice. The mammary cancer models of BALB/c nude mice were set up using MCF-7 cells, and were divided into seven groups: MTO-VCR-LP, MTO-VCR-Soln, VCR-LP, VCR-Soln, MTO-LP, MTO-Soln and 0.9% NaCl. After the first treatment in the same day of transplantation, different treatments were given respectively. According to the design, the BLAB/c nude mice were given the therapy, the weight of nude mice and tumor volume were measured, and the tumor growth inhibitory rate was calculated. Bone marrow smears and extravasation injury were observed. The tumor growth inhibitory rates were higher in MTO-VCR-LP and MTO-VCR-Soln groups than in other groups. MTO-VCR-Soln, VCR-Soln and MTO-Soln led to severe local extravasation injury. MTO-VCR-Soln cause serious bone marrow inhibition of nude mice. The average weight of nude mice in the three liposome groups was higher than that in the three solution groups. So the use of liposome as the carriers of the two anticancer drugs could improve the cure rate of cancer and decrease the side-effects. This work, which not only expanded the research field of liposome but also brought in new ideas and new methods to treat cancer. Furthermore, the findings in this research may have the potential for use in clinical practice.

Horseradish peroxidase immobilized on the magnetic composite microspheres for high catalytic ability and operational stability.

In the present study, a novel and efficient immobilization for horseradish peroxidase (HRP) had been developed by using 6-arm magnetic composite microsphere (Fe3O4@PAA-6-arm-PEG-NH2) containing 6-arm polyethylene glycol (6-arm-PEG-NH2) and Fe3O4. The morphology and chemical properties of Fe3O4@PAA-6-arm-PEG-NH2 were characterized by transmission electron microscopy (TEM), Fourier transform infrared spectra (FTIR), X-ray powder diffraction (XRD), vibrating sample magnetometer (VSM) and thermogravimetric analysis (TGA). The immobilization conditions and loading capacity of the carrier toward HRP were also investigated. According to the results, the optimum immobilization conditions were as follows: glutaraldehyde concentration of 0.10 mol L-1, the carrier concentration of 7 mg L-1, the temperature of 35 °C and immobilization time of 180 min. The loading capacity of the immobilized HRP arrived to 139.82 mg g-1 (RSD = 0.87%). Compared with free HRP, the stability of the immobilized HRP had been enhanced in a wide range of temperature and pH. The activity of the immobilized HRP retained 71.05% of its initial activity after 60 days storage. It was also found that the activity of the immobilized HRP retained 61.06% of its initial activity after eight times of successive reuse. The immobilized HRP could hydrolyze phenol to 94.4% within 10 min. It proved that the immobilized HRP could improve the performance of HRP, which had a good prospect in biological application.

Parameters affecting the formation mechanisms of dioxins in the steel manufacture process.

With the implementation of the new national standards in the steel industry, dioxins (polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs)) emission and control have attracted more and more attention in China. The PCDD/Fs levels and signatures of nine steelmaking materials and by-products were experimentally analysed and compared, including five kinds of steelmaking fly ash (sintering fly ash, basic oxygen furnace fly ash, electric arc furnace fly ash and two kinds of blast furnace fly), three kind of steel sludge (continuous casting sludge, hot rolling sludge and cold rolling sludge) and sintering raw material. Dioxin formation from the sintering fly ash was highest of all 9 materials. Furthermore, highly chlorinated PCDD/Fs homologues were abundant in that sample, while the profiles were contrary to those of other materials. More importantly, the entire isomer signatures of all 61 samples were analysed, involving various materials, temperatures, oxygen levels, particle size and inhibitors, with special emphasis on those congeners associated with chlorophenol precursor routes, as well as seventeen 2,3,7,8-substituted PCDD/Fs. Strong correlation was found among seven PCDD-congeners of CP-route. The analysis of the molecular structure of these congeners revealed that 2,4,6/2,3,5-trichlorophenol may act as a precursor to form all those PCDD-congeners by condensation. In addition, the influence of various factors (temperature, oxygen level, particle size, inhibitors addition etc.) on the relative importance of CP-route congeners and 2,3,7,8-substituted congeners was discussed, with the goal of shedding more light on the mechanism of PCDD/Fs-formation.