Purification and biochemical characterization of a novel ene- reductase from Kazachstania exigua HSC6 for dihydro-ß-ionone from ß-ionone.

PURPOSE: We purified and characterized a novel ene-reductase (KaDBR1) from Kazachstania exigua HSC6 for the synthesis of dihydro-ß-ionone from ß-ionone. METHODS: KaDBR1 was purified to homogeneity by ammonium sulfate precipitation and phenyl-Sepharose Fast Flow and Q-Sepharose chromatography. The purified enzyme was characterized by measuring the amount of dihydro-ß-ionone from ß-ionone with LC-MS analysis method. RESULTS: The molecular mass of KaDBR1 was estimated to be 45 kDa by SDS-PAGE. The purified KaDBR1 enzyme had optimal activity at 60 °C and pH 6.0. The addition of 5 mM Mg2+, Ca2+, Al3+, Na+, and dithiothreitol increased the activity of KaDBR1 by 25%, 18%, 34%, 20%, and 23%, respectively. KaDBR1 favored NADH over NADPH as a cofactor, and its catalytic efficiency (kcat/Km) toward ß-ionone using NADH was 8.1-fold greater than when using NADPH. CONCLUSION: Owing to its unique properties, KaDBR1 is a potential candidate for the enzymatic biotransformation of ß-ionone to dihydro-ß-ionone in biotechnology applications.

The association of cytokine gene polymorphisms with tuberculosis susceptibility in several regional populations.

PURPOSE: By collecting the data of all relevant articles, the goal of this study was to better understand the relationship between the IL-6/IL-18 polymorphism and susceptibility to tuberculosis in several regional populations. METHODS: Pubmed, Embase, WOS and CNKI were used to find relevant literature. The findings of separate research were merged using Review Manager. RESULTS: A total of 25 studies were included in this study. IL-6 rs1800795 (dominant. comparison: p-value < 0.0001, OR 1.43, 95 % CI 1.23-1.67; recessive comparison: p-value < 0.0001, OR 0.48, 95 % CI 0.35-0.65; allele comparison: p-value < 0.0001, OR 1.43, 95 % CI 1.27-1.62), IL-18 rs1946518 (dominant comparison: p-value = 0.01, OR 1.19, 95 % CI 1.04-1.35; recessive comparison: p-value = 0.01, OR 0.82, 95 % CI 0.71-0.96; allele comparison: p-value = 0.002, OR 1.14, 95 % CI 1.05-1.24), IL-18 rs187238 (dominant comparison: p-value = 0.0002, OR 1.35, 95 % CI 1.15-1.58; allele comparison: p-value < 0.0001, OR 1.31, 95 % CI 1.14-1.50). All gene polymorphisms were shown to be substantially linked to tuberculosis in the general population. Positive findings of rs187238 and rs1800795 polymorphisms were primarily driven by several regional populations, according to subgroup analyses. CONCLUSION: This meta-analysis found that the the IL-6 rs1800795and IL-18 rs187238 polymorphisms may have a role in TB susceptibility.

The potentially therapeutic targets of pediatric anaplastic ependymoma by transcriptome profiling.

Ependymoma (EPN) is a type of tumor that occurs in the central nervous system of children and adults. EPN produces resistance to chemotherapy, and there are no targeted drugs available as a proper cure. Therefore, the use of high-throughput sequencing technologies to elucidate pathogenic mechanisms is of prime importance to identify potential tumor target genes helpful for developing effective therapeutic approaches against EPN. With this objective, we used RNA-seq analysis to identify differentially expressed genes (DEGs) and pathways in 4 pairs of EPN tissues and adjacent tissues. In total, we found 5,445 differentially expressed genes. The synaptic vesicle cycle and extracellular matrix (ECM) receptor interaction pathways were highly enriched in the ependymoma group. Nine differentially expressed genes (SNAP25, GRM4, CELSR1, LAMA1, WNT5A, ROR2, CCND1, EPHB2, FOXJ1) were randomly verified by RT-qPCR, supporting the authenticity of our sequencing results. This study provides global gene information and some new potential biomarkers for the diagnosis and therapeutic targets of ependymoma.

A novel thermophilic ß-carotene 15,15'-monooxygenase with broad substrate specificity from the marine bacterium Candidatus Pelagibacter sp. HTCC7211.

To characterize a novel thermophilic ß-carotene 15,15'-monooxygenase BCMO7211 isolated from the marine bacterium Candidatus Pelagibacter sp. HTCC7211. BCMO7211 was functionally overexpressed in Escherichia coli and purified to homogeneity by Ni-NTA affinity chromatography and Superdex-200 gel filtration chromatography. Labeling experiments with H218O demonstrated that the oxygen atom in the terminal aldehyde group of the produced retinal molecules was provided from both molecular oxygen and water, indicating that BCMO7211 is the first characterized bacterial ß-carotene 15,15'-monooxygenase. BCMO7211 exhibited broad carotenoid substrate specificity toward α-carotene, ß-cryptoxanthin, ß-carotene, zeaxanthin, and lutein. The optimum temperature, pH, and concentrations of the substrate and enzyme for retinal production were 60 °C, 9.0, 500 mg ß-carotene/L, and 2.5 U/ml, respectively. Under optimum conditions, 888.3 mg/L retinal was produced in 60 min with a conversion rate of 89.0% (w/w). BCMO7211 is a potential candidate for the enzymatic synthesis of retinal in biotechnological applications.

Effect of PFDTS/TiO2 Coating on Microstructure and Wetting Behavior of Phosphogypsum.

Phosphogypsum (PG) constitutes a form of solid byproduct emanating from the manufacturing process of wet-process phosphoric acid. The fabrication of one metric ton of wet-process phosphoric acid entails the generation of approximately five tons of phosphogypsum, a highly prolific and economically viable waste stream. If we can effectively solve the problem of poor hydrophobicity of phosphogypsum, it is possible to replace cement and other traditional cementitious materials. In this way, we can not only improve the utilization rate of phosphogypsum but also obtain significant economic and environmental benefits. In the present investigation, hydrophobic surface coatings were synthesized and applied onto the surface of α-hemihydrate phosphogypsum (α-HPG) utilizing sol-gel processing and impregnation techniques. After hydroxylating α-HPG with alkaline solution (OH-α-HPG), titanium dioxide nanoparticles (TiO2) hybridized with perfluorodecyltriethoxysilane (PFDTS) were grafted on its surface. The assessment of the hydrophobic properties of the coatings was conducted through water contact angle measurements, Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM) analyses. The contact angle remained above 124.2° after strong acidic and alkaline immersion and 50 tape adhesion experiments with good chemical stability and durability, and the mechanism of surface hydrophobicity modification was discussed. The experimental outcomes demonstrated a notable increase in the hydroxyl group concentration on the α-HPG surface following hydroxylation, significantly enhancing the attachment rate of PFDTS and TiO2 onto the HPG surface. PFDTS and TiO2 can undergo chemical interaction with hydroxyl groups, facilitating their robust adsorption onto the surface of OH-α-HPG through chemisorption mechanisms. After bonding the OH-α-HPG surface with PFDTS and TiO2 via hydrogen bonding, the otherwise hydrophilic α-HPG surface acquired excellent hydrophobicity (OH-α-HPG-PT, contact angle (CA) = 146.7°). The surface modification of α-HPG through hydroxylation and hydrophobicity enhancement significantly augmented the compatibility and interfacial interplay between α-HPG and PT. This research successfully enhanced the hydrophobic properties of α-HPG, profoundly showcasing its immense potential within the construction industry and the realm of comprehensive solid waste utilization.

Enhanced Cycling Performance of Spinel LiNi0.5Mn1.5O4 Cathodes through Mg-Mn Hetero-Valent Doping via Microwave Sol-Gel Method.

As a high energy density cathode material, further development of high working voltage spinel LiNi0.5Mn1.5O4 has hindered by its rapid capacity degradation. To address this, a hetero-valent substitution of magnesium for manganese was used to synthesize spinel LiNi0.5MgxMn1.5-xO4 (x = 0, 0.03, 0.05) via a microwave sol-gel method. XRD and refined results indicate that such strategy leads to the modification of the 16c interstitial sites. The electrical performance demonstrates that a modest substitution (x = 0.03) significantly improves both rate performance (113.1 mAh/g, charge and discharge at 5 C) and cycling stability (85% capacity retention after 500 cycles at 1 C). A higher substitution level (x = 0.05) markedly improves high-rate cycling performance, achieving 96% capacity retention after 500 cycles at 5 C. It offers tailored solutions for various application needs, including capacity-focused and high-current-rate applications. Furthermore, the stable LiNi0.5Mg0.05Mn1.45O4 sample could also serve as an effective coating layer for other electrode materials to enhance their cycling stability.

A case report of using gauze packing to treat postoperative chest bleeding after left pneumonectomy for secondary rifampicin-resistant tuberculosis.

One patient with rifampin-resistant tuberculosis underwent emergency left pneumonectomy and thoracic gauze packing for hemoptysis due to recurrent hemoptysis after transcatheter arterial embolization. Vital signs were maintained by mechanical ventilation and medication. Tracheotomy and anti-tuberculosis treatment were performed. After half a year of follow-up, the patient's condition was stable.

An image reconstruction algorithm for electrical capacitance tomography based on robust principle component analysis.

Electrical capacitance tomography (ECT) attempts to reconstruct the permittivity distribution of the cross-section of measurement objects from the capacitance measurement data, in which reconstruction algorithms play a crucial role in real applications. Based on the robust principal component analysis (RPCA) method, a dynamic reconstruction model that utilizes the multiple measurement vectors is presented in this paper, in which the evolution process of a dynamic object is considered as a sequence of images with different temporal sparse deviations from a common background. An objective functional that simultaneously considers the temporal constraint and the spatial constraint is proposed, where the images are reconstructed by a batching pattern. An iteration scheme that integrates the advantages of the alternating direction iteration optimization (ADIO) method and the forward-backward splitting (FBS) technique is developed for solving the proposed objective functional. Numerical simulations are implemented to validate the feasibility of the proposed algorithm.

Difference of Convex Functions Programming With Machine-Learning Prior for the Imaging Problem in Electrical Capacitance Tomography.

The electrical capacitance tomography technology has potential benefits for the process industry by providing visualization of material distributions. One of the main technical gaps and impediments that must be overcome is the low-quality tomogram. To address this problem, this study introduces the data-guided prior and combines it with the electrical measurement mechanism and the sparsity prior to produce a new difference of convex functions programming problem that turns the image reconstruction problem into an optimization problem. The data-guided prior is learned from a provided dataset and captures the details of imaging targets since it is a specific image. A new numerical scheme that allows a complex optimization problem to be split into a few less difficult subproblems is developed to solve the challenging difference of convex functions programming problem. A new dimensionality reduction method is developed and combined with the relevance vector machine to generate a new learning engine for the forecast of the data-guided prior. The new imaging method fuses multisource information and unifies data-guided and measurement physics modeling paradigms. Performance evaluation results have validated that the new method successfully works on a series of test tasks with higher reconstruction quality and lower noise sensitivity than the popular imaging methods.

Lymph node dissection effectively shortens the course of anti-tuberculosis treatment.

Objective: To evaluate the clinical efficacy of postoperative ultra-short-course chemotherapy in treating cervical lymph node tuberculosis in the Wuhan region. Methods: Follow-up of patients in the surgery and non-surgery group after discharge, evaluating the number of cervical lymph nodes during the administration of antituberculosis drugs. Results: The age of the patients in the surgical therapy group ranged from 6 to 83 years old with an average age of 45 and a standard deviation of 20. The number of cervical lymph nodes in the patients ranged from 1.61 to 8.15. The average antituberculosis treatment duration before surgery for patients in the surgical group was 98.02 days, while for patients in the non-surgical group it was 96.13 days. The average length of hospital stay for patients receiving surgical treatment was 12.76 days, while for patients receiving non-surgical treatment it was 8.74 days. The average antituberculosis treatment duration after discharge for patients in the surgical group was 205 days, with a standard deviation of 42.39, while for patients in the non-surgical group it was 372 days, with a standard deviation of 71.54. The T-test results for antituberculosis treatment during hospitalization and after discharge were 98.3x10-10 and 5.02x10-67, respectively. Conclusion: After surgical treatment of cervical lymph node tuberculosis, the effectiveness of a 4-6 month short-course chemotherapy in Wuhan region is not weaker than the effectiveness of a conventional 6-9 month drug treatment.

Comparative analysis of five etiological detecting techniques for the positive rates in the diagnosis of tuberculous granuloma.

Purpose: To examine the relationship between the positive rate and types of necrosis in pathological examinations of tuberculosis granulomas with necrosis, to improve the detection rate of positive cases. Methods: Specimens from 381 patients were collected in Wuhan Pulmonary Hospital from Jan 2022 to Feb 2023. The samples were examined using various methods such as AFB smear microscopy, mycobacterial culture, PCR, SAT-TB, and X-pert MTB/RIF rapid molecular detection. Result: There were 3 types of necrosis. Including 270 cases of caseous necrosis, 30 cases of coagulation necrosis, and 76 cases of an abscess. Five cases were non-necrotizing granulomas.In the pathological specimen testing for tuberculosis, five detection techniques were used and their positive rates detected in descending order were X-pert, TBDNA, SAT-TB, tuberculosis culture, AFB. Comparison between different examinations in the group: X-pert had the highest positive rate in each group, and it was significantly higher than TBDNA (P < 0.01) in caseous necrosis specimens. Compared with the same examination between the groups, the detection rates of X-pert and TBDNA in abscess and caseous necrosis specimens were significantly higher than in coagulation necrosis specimens (P < 0.01). Conclusion: The positive rates of the five etiological detection techniques in tuberculous granuloma with different types of necrosis were quite different. The specimens of caseous necrosis or abscess could be selected for detection, and X-pert had the highest positive rate.

Preparation and Performance of H-PDMS/PMHS/OTS Hybrid Nanosilica Hydrophobic and Self-Cleaning Coatings on Phosphogypsum Surface.

Hemihydrate phosphogypsum, an industrial solid waste product of phosphoric acid production, is abundant and inexpensive. If the problem of poor water resistance is solved, this material could be substituted for cement and other traditional energy-consuming cementitious materials in the construction industry. This approach would confer important economic and environmental benefits while promoting the resource utilization of phosphogypsum (PG). In this study, hydrophobic and self-cleaning coatings of H-PDMS/PMHS/OTS hybrid nanosilica were prepared on a post-hydroxylated PG surface using sol-gel and impregnation methods. The water contact angle, Fourier-transform infrared spectroscopy, Three-dimensional surface morphology and roughness analysis, X-ray photoelectron spectroscopy, scanning electron microscopy, surface abrasion tests, and tape adhesion tests were used to evaluate the hydrophobicity of the coatings. The results demonstrated that the in situ reaction produced a hydrophobic siloxane/nanosilica hybrid network that bonded to the PG surface via hydrogen bonding, making the otherwise completely hydrophilic PG hydrophobic (PGH-3, contact angle (CA) = 144.1°). The PGH-3 sample exhibited excellent chemical stability, maintaining a contact angle greater than 135° under strongly acidic or alkaline conditions. The contact angle remained at 123.7° after 50 tape-bonding tests. After 100 wear cycles, the contact angle remained at 121.9°. This study presents an environmentally friendly method and a straightforward application procedure to impart hydrophobicity to solid waste PG. Its potential is thus demonstrated in the field of PG-based construction materials and the comprehensive utilization of solid waste.

The safety and efficacy of decortication for stage III drug-resistant tuberculous empyema.

OBJECTIVES: The goal of this study was to evaluate the safety and efficacy of decortication for stage III drug-resistant tuberculous empyema (TE). METHODS: We analysed all patients with stage III TE who underwent decortication between March 2015 and October 2019 at Wuhan Pulmonary Hospital. The patients were divided into 2 groups according to drug-susceptibility testing of bronchoscopy lavage fluid, pleural effusion and tissue specimens, including a drug-resistant group and a drug-sensitive group. We collected and compared the preoperative, perioperative and postoperative data from the 2 groups to evaluate the safety and efficacy of decortication for stage III drug-resistant TE. RESULTS: In total, 135 cases met the inclusion criteria and were enrolled, including 30 cases in the drug-resistant group and 105 cases in the drug-sensitive group. No deaths were recorded for the entire study population. Compared to the drug-sensitive group, the drug-resistant group had longer operation times (259.8 ± 78.4 min vs 187.2 ± 56.0 min, P = 0.00), a larger volume of intraoperative blood loss [300 (200,400) ml vs 200 (130, 300) ml, P = 0.00] and a higher intraoperative transfusion rate (5/30, 16.7% vs 4/105, 3.8%, P = 0.04). The rate of complications was significantly higher in the drug-resistant group (23; 76.7%) than in the drug-sensitive group (53; 50.5%) (P = 0.01). Recurrence was not reported in any of the patients. Twenty-three (76.7%) patients in the drug-resistant group and 90 (85.7%) patients in the drug-sensitive group recovered to an "excellent" level, and 3 cases in each group recovered to a "poor" level; there was no significant difference between the 2 groups in surgical effects (P = 0.21). CONCLUSIONS: Decortication is a safe, effective and feasible option for patients with stage III drug-resistant TE, although the operation is difficult and risky.

Feasibility and safety of uniportal thoracoscopy for chronic pulmonary aspergillosis.

Surgery plays a crucial role in the treatment of patients with chronic pulmonary aspergillosis (CPA). However, there is currently limited information available regarding the use of uniportal thoracoscopy (Uni-VATS) in CPA patients. To address this gap, we conducted a retrospective analysis of surgical procedures performed at a single center, aiming to demonstrate the feasibility and safety of Uni-VATS for patients with CPA. We collected basic information and surgical data from patients who underwent surgery for CPA at our hospital between January 2018 and June 2022. All patients received voriconazole antifungal medication for 3-6 months post-surgery and were monitored for a minimum of 6 months. A total of 110 patients, comprising 59 cases in the traditional open chest incision group and 51 cases in the Uni-VATS group, met the inclusion criteria. Among those who underwent surgery, 70% were male (77/110). The median age (IQR) of all enrolled patients was 55 (46-62) years. There were no statistically significant differences in general information, such as age, sex, comorbidities, BMI, FEV1, FVC, clinical symptoms, location of the disease, and duration of voriconazole antifungal medication, between the OS group and the Uni-VATS group (p > 0.05). The postoperative complication rates were 40.7% (24/59) for the traditional open chest incision group and 17.6% (9/51) for the Uni-VATS group. Through univariate analysis, we identified sex and operative approach as risk factors for postoperative complications. Multivariate logistic analysis confirmed that male and OS procedures were the independent risk factors for postoperative complications. There were statistically significant differences in operative time, intraoperative blood loss volume, postoperative drainage volume, pain scores, postoperative drainage tube removal time, postoperative hospital stay time between the OS group and the Uni-VATS group (p < 0.05). Uni-VATS is a feasible and safe surgical procedure for patients with CPA, and we recommend it as a preferred option for selected patients with CPA.

Approach to Significantly Enhancing the Electrochromic Performance of PANi by In Situ Electrodeposition of the PANi@MXene Composite Film.

Electrochromic materials (ECMs) are capable of reversibly adjusting their transmittance or reflectance properties in response to changes in the external biasing voltages. In this study, we enhanced the electrochromic and electrochemical properties of polyaniline (PANi) effectively through the incorporation of MXene Ti2CTx using an in situ composite strategy. This improvement in the electrochromic and electrochemical properties observed can be attributed to the intermolecular forces between the aniline group of PANi and the terminal groups of MXene Ti2CTx sheets. The presence of hydrogen bonds between the PANi monomers and the MXene sheets was confirmed through theoretical calculations and photoluminescence results, which effectively improved the composite interfaces. Additionally, the PANi@MXene composite films were successfully prepared through a simple one-step in situ polymerization process, as verified by SEM and XPS characterization. The electrochemical studies revealed enhanced electronic conductivity, a high ion diffusion coefficient, and a narrow energy redox gap, all contributing to the excellent electrochemical properties observed. Overall, our results demonstrate that the MXene Ti2CTx composition effectively enhances the electrochromic performance of PANi. The PANi@MXene composite films exhibited a high optical modulation range, rapid switching response time, good thermal radiation regulation, and excellent operational stability. This composite strategy significantly improves the performance and practical applicability of ECMs.

Effect of Synergistic Modification of Building Materials Based on α-Hemihydrate Phosphogypsum by Portland Cement/H-PDMS on Water Resistance.

Alpha-hemihydrate phosphogypsum (α-HPG) is a cementitious material obtained by dehydration of phosphogypsum (PG), a byproduct of phosphoric acid production. Poor water resistance of α-HPG has usually restricted its application in construction materials. In this study, hydroxy-terminated polydimethylsiloxane (H-PDMS) and Portland cement (PC) were used for the hydrophobic modification of α-HPG. The fluidity, setting times, compressive strength, flexural strength, ratio of compressive to flexural strength, water absorption rate, softening coefficient, pore structure, chemical information, and microstructure of the samples were measured to evaluate the modification effect of H-PDMS and PC. The results showed that H-PDMS and PC significantly improved waterproof properties of α-HPG and reduced its porosity, total pore area, and pore diameter. Specifically, PC provided the reactive group -OH that reacted with H-PDMS. Also, due to the coverage of hydrophobic -CH3 groups, PG was given an overall hydrophobicity with a contact angle of 134° (1.5% H-PDMS). H-HPG (H-PDMS- and PC-modified α-HPG) hydrophobic material can be used in building materials with waterproof requirements and achieve the comprehensive utilization of solid waste PG.

Comparative analysis of five inspection techniques for the application in the diagnosis and treatment of osteoarticular tuberculosis.

OBJECTIVE: To evaluate five examination techniques in the diagnosis and treatment of osteoarticular tuberculosis (TB). METHODS: Microbiological samples were collected from a total of 284 patients during the period August 2017 to December 2019 in Wuhan Pulmonary Hospital. The specimens were examined by acid-fast bacillus (AFB) smear microscopy, mycobacterial culture, PCR, T-SPOT.TB, and X-pert MTB/RIF rapid molecular detection. RESULTS: The diagnostic sensitivity of the Xpert technology was 96.8% (116/120), specificity was 96.8% (58/60), the Youden index was 0.936, and the area under the receiver operating characteristic (ROC) curve was 0.967. The sensitivity and specificity of PCR were 84.2% (104/128) and 95.2% (76/80), respectively; the area under the ROC curve was 0.881. T-SPOT.TB had a detection sensitivity of 75.0% (12/16) and specificity of 85.0% (17/20). AFB smear microscopy had a sensitivity of 60.0% (75/125) and specificity of 95.8% (152/159). TB culture sensitivity was 58.1% (72/124) and specificity was 96.2% (73/76). The sensitivity and specificity of Xpert MTB/RIF for detecting rifampicin resistance were 100% (2/2) and 97.3% (73/75), respectively. CONCLUSIONS: The Xpert MTB/RIF technique was found to have a good diagnostic value. With an additional diagnosis of Rifampicin resistance, it was also useful in tuberculosis therapy.

Production, characterization, and bioactivities of exopolysaccharides from the submerged culture of Ganoderma cantharelloideum M. H. Liu.

In this study, the submerged culture conditions for exopolysaccharide (EPS) production by Ganoderma cantharelloideum M. H. Liu were screened and optimized, and the physicochemical and biological properties of EPS were investigated. Results showed that the glucose and tryptone were the best C and N sources for the maximum EPS production, respectively. Under the optimal culture conditions, the EPS production achieved 1.60 g/L at day 6 in a 5 L stirred tank reactor. Two purified fractions (i.e., Fr-I and Fr-II) were obtained from the G. cantharelloideum EPS by gel permeation chromatography. Fr-II had a higher yield (87.54%), carbohydrate (95.86%), and protein (3.07%) contents and lower molecular weight (74.56 kDa) than that of Fr-I. Both Fr-I and Fr-II were polysaccharide-protein complexes with different monosaccharide compositions and chemical structures. Fr-II also exhibited stronger radical scavenging abilities, antioxidant capacities, and α-amylase and α-glycosidase inhibitory activities in vitro than that of Fr-I. Therefore, Fr-II obtained from G. cantharelloideum EPS might be explored as potential natural functional components or supplements for applications in food, medicine, and cosmetics.

Effect of doping different Si source on Ca-P bioceramic coating fabricated by laser cladding.

The doping of silicon (Si) has been proved to improve the bioactivity of Ca-P ceramics. In light of this thinking, in the present study, Ca-P coatings with La2O3 by addition of 10 wt% SiO2 and 10 wt% diatomaceous earth (DE) were fabricated by laser cladding on Ti6Al4V, respectively. Coating doped without Si was also fabricated as the comparison group for the experiment. The effect of two different Si sources on the surface morphology, microstructure, microhardness, and bioactivity was systematically studied. The experimental results show that the Si-doped coating is of rough surface morphology, and the addition of DE significantly reduces the number of cracks and improves the microhardness. The X-ray diffraction results reveal that the amount of bioactive phase tricalcium-phosphate (TCP) and hydroxyapatite (HA) reaches maximum in the DE-doped coating. After soaking in simulated body fluid (SBF), the precipitate of bone-like apatite in the DE-doped coating is significantly higher than that of the other coatings.

Study on microstructure, microhardness, bioactivity, and biocompatibility of La2 O3 -containing bioceramic coating doping SiO2 fabricated by laser cladding.

To solve the lack of strength of calcium phosphate ceramic coatings in load-bearing applications, gradient Ca-P bioceramic coatings doped with La2 O3 and SiO2 are fabricated by laser cladding on Ti-6Al-4 V. The effect of SiO2 on microstructure, microhardness, bioactivity, and biocompatibility of coatings was investigated. The experimental results illustrate that the coating doped with La2 O3 and SiO2 has excellent metallurgical bonding. The XRD analysis confirms that the amount of hydroxyapatite and tricalcium phosphate in the coating reached maximum when doping amount of SiO2 is 10 wt %. SiO2 -doped coatings show a significantly higher bone-like apatite precipitation after immersion in SBF than that of other coatings. in vitro experiment also shows that coating with 10 wt % SiO2 is more suitable for the attachment and proliferation of MG63 cells, indicating that coating with 10 wt % SiO2 exhibits best bioactivity and biocompatibility. These results suggest that the addition of SiO2 improves the bonding strength, bioactivity, and biocompatibility of coatings.