Investigating the Corrosion Resistance of Different SiC Crystal Types: From Energy Sectors to Advanced Applications.

Silicon carbide, as a third-generation semiconductor material, plays a pivotal role in various advanced technological applications. Its exceptional stability under extreme conditions has garnered a significant amount of attention. These superior characteristics make silicon carbide an ideal candidate material for high-frequency, high-power electronic devices and applications in harsh environments. In particular, corrosion resistance in natural or artificially acidic and alkaline environments limits the practical application of many other materials. In fields such as chemical engineering, energy conversion, and environmental engineering, materials often face severe chemical erosion, necessitating materials with excellent chemical stability as foundational materials, carriers, or reaction media. Silicon carbide exhibits outstanding performance under these conditions, demonstrating significant resistance to corrosive substances such as hydrochloric acid, sulfuric acid, nitric acid, and alkaline substances such as potassium hydroxide and sodium hydroxide. Despite the well-known chemical stability of silicon carbide, the stability conditions of its different types (such as 3C-, 4H-, and 6H-SiC polycrystals) in acidic and alkaline environments, as well as the specific corrosion mechanisms and differences, warrant further investigation. This Review not only delves deeply into the detailed studies related to this topic but also highlights the current applications of different silicon carbide polycrystals in chemical reaction systems, energy conversion equipment, and recycling processes. Through a comprehensive analysis, this Review aims to bridge research gaps, offering a comparative analysis of the advantages and disadvantages between different polymorphs. It provides material scientists, engineers, and developers with a thorough understanding of silicon carbide's behavior in various chemical environments. This work will propel the research and development of silicon carbide materials under extreme conditions, especially in areas where chemical stability is crucial for device performance and durability. It lays a solid foundation for ultra-high-power, high-integration, high-reliability module architectures, supercomputing chips, and highly safe long-life batteries.

A Topology-Defined Polyester Elastomer from CO2 and 1,3-Butadiene: A One-Pot-One-Step "Scrambling Polymerizations" Strategy.

It is significant and challenging to use CO2 to produce polymeric materials, especially with olefins. Here, a novel strategy named "scrambling polymerizations" is designed and performed for the copolymerization of a CO2 -and-1,3-butadiene-derived valerolactone, 3-ethylidene-6-vinyltetrahydro-2H-pyran-2-one (EVL), with ϵ-caprolactone (CL) to prepare polyesters. Anionic ring-opening polymerization of CL and conjugated addition oligomerization of EVL take place individually to form PCL and EVL oligomers, respectively. Then EVL oligomers insert into PCL by transesterification resulting in polyester P(CL-co-EVL) with a tunable topology and composition. The non-cytotoxic and degradable polyester network with elongation at break of >600 % can be used as an elastomer. We propose a method to provide polyester elastomers from CO2 and olefins for the first time, and expand the potential of transformation from sustainable feedstocks to polymeric materials.

Protective effects of ectoine on articular chondrocytes and cartilage in rats for treating osteoarthritis.

Osteoarthritis (OA) is a chronic degenerative disease that primarily includes articular cartilage destruction and inflammatory reactions, and effective treatments for this disease are still lacking. The present study aimed to explore the protective effects of ectoine, a compatible solute found in nature, on chondrocytes in rats and its possible application in OA treatment. In the in vitro studies, the morphology of the chondrocytes after trypsin digestion for 2 min and the viability of the chondrocytes at 50°C were observed after ectoine treatment. The reactive oxygen species (ROS) levels in chondrocytes pretreated with ectoine and post-stimulated with H2O2 were detected using an ROS assay. Chondrocytes were pretreated with ectoine before IL-1ß stimulation. RT‒qPCR was used to measure the mRNA levels of cyclooxygenase-2 (COX-2), metallomatrix proteinase-3, -9 (MMP-3, -9), and collagen type II alpha 1 (Col2A1). In addition, immunofluorescence was used to assess the expression of type II collagen. The in vivo effect of ectoine was evaluated in a rat OA model induced by the modified Hulth method. The findings revealed that ectoine significantly increased the trypsin tolerance of chondrocytes, maintained the viability of the chondrocytes at 50°C, and improved their resistance to oxidation. Compared with IL-1ß treatment alone, ectoine pretreatment significantly reduced COX-2, MMP-3, and MMP-9 expression and maintained type II collagen synthesis in chondrocytes. In vivo, the cartilage of ectoine-treated rats exhibited less degeneration and lower Osteoarthritis Research Society International (OARSI) scores. The results of this study suggest that ectoine exerts protective effects on chondrocytes and cartilage and can, therefore, be used as a potential therapeutic agent in the treatment of OA.

A probabilistic approach for assessing the mechanical performance of intertrochanteric fracture stabilized with proximal femoral nail antirotation.

Maintaining post-operative mechanical stability is crucial for successfully healing intertrochanteric fractures treated with the Proximal Femoral Nail Antirotation (PFNA) system. This stability is primarily dependent on the bone mineral density (BMD) and strain on the fracture. Current PFNA failure analyses often overlook the uncertainties related to BMD and body weight (BW). Therefore, this study aimed to develop a probabilistic model using finite element modeling and engineering reliability analysis to assess the post-operative performance of PFNA under various physiological loading conditions. The model predictions were validated through a series of experimental test. The results revealed a negative nonlinear relationship between the BMD and compressive strain. Conversely, the BW was positively and linearly correlated with the compressive strain. Importantly, the compressive strain was more sensitive to BW than to BMD when the BMD exceeded 0.6 g/cm3. Potential trabecular bone compression failure is also indicated if BMD is equal to or below 0.15 g/cm3 and BW increases to approximately 2.5 times the normal or higher. This study emphasizes that variations in the BMD significantly affect the probability of failure of a PFNA system. Thus, careful planning of post-operative physical therapy is essential. For patients aged > 50 years restrictions on high-intensity activities are advised, while limiting strenuous movements is recommended for those aged > 65 years.

SiC@FeZnZiF as a Bifunctional Catalyst with Catalytic Activating PMS and Photoreducing Carbon Dioxide.

Herein, we encapsulated modified silicon carbide nanoparticles utilizing a metal-organic backbone. E-SiC-FeZnZIF composites were successfully prepared via Fe doping. The catalysis activity of this bifunctional composite material was evaluated by the degradation of tetracycline (THC) and carbamazepine (CBZ) and the reduction of carbon dioxide (CO2). Nano SiC has received widespread attention in advanced oxidation applications, especially in the catalytic activation of peroxymonosulfate (PMS). However, the inferior activity of SiC has severely restricted its practical use. In this study of dual functional composite materials, nano SiC was firstly etched under aqueous alkali. Then, zeolite imidazolate frame-8 (ZIF-8) was used for immobilization. The filling of the etched nano SiC with FeZnZiF was confirmed by SEM, XRD, FTIR, BET, and XPS analyses. In addition, E-SiC-FeZnZIF exhibited excellent catalytic activation of peroxymonosulfate (PMS) to oxidize water pollutants, which can degrade tetracycline hydrochloride (THC), achieving a removal rate of 72% within 60 min. Moreover, E-SiC-FeZnZIF exhibited a relatively high CO2 reduction rate with H2O. The yields of CO and CH4 were 0.085 and 0.509 µmol g-1, respectively, after 2 h, which are higher than that of 50 nm of commercial SiC (CO: 0.084 µmol g-1; CH4: 0.209 µmol g-1). This work provides a relatively convenient synthesis path for constructing metal skeleton composites for advanced oxidation and photocatalytic applications. This will have practical significance in protecting water bodies and reducing CO2, which are vital not only for maintaining the natural ecological balance and negative feedback regulation, but also for creating a new application carrier based on nano silicon carbide.

Sesquiterpene lactones-enriched fractions from Xanthium mongolicum Kitag alleviate RA by regulating M1 macrophage polarization via NF-κB and MAPK signaling pathway.

Introduction: Rheumatoid arthritis (RA) is a chronic autoimmune disease, characterized by activated M1-like macrophage in the joint. Xanthium mongolicum Kitag (X. mongolicum) is a traditional medicinal plant that has long been used to treat RA and other immune diseases in China. Methods: Fractions of X. mongolicum were separated based on polarity. Anti-RA activity of the fractions were screened by LPS-stimulated RAW264.7 macrophage in vitro. The major active compounds were identified by UPLC-MS and quantified by HPLC. The anti-RA effects of the active fraction was evaluated in complete freund's adjuvant (CFA)-induced arthritis and collagen-induced arthritis (CIA) mouse models in vivo and LPS-stimulated macrophage in vitro. Results: Sesquiterpene lactones-enriched fraction from X. mongolicum (SL-XM) exhibited the strongest anti-RA activity among all components in vitro. Five major constituents i.e., Xanthinosin (1), Xanthatin (2), Mogolide D (3), Mogolide E (4), and Mogolide A (5) were identified as major compounds of SL-XM. SL-XM ameliorated symptoms of CFA and CIA induced arthritis mice model. Furthermore, SL-XM treatment inhibited LPS-induced M1 macrophages polarization. In addition, SL-XM inhibited the phosphorylation of NF-κB and MAPK signaling pathways in LPS-induced macrophage and CIA-challenged mice. Discussion: The main anti-RA active fraction of X. mongolicum may be the Sesquiterpene lactones, which includes five key compounds. SL-XM may exert its anti-RA effect by suppressing M1 macrophage polarization via the NF-κB and MAPK signaling pathway.

In Situ Fabrication of Mn-Doped NiMoO4 Rod-like Arrays as High Performance OER Electrocatalyst.

The slow kinetics of the oxygen evolution reaction (OER) is one of the significant reasons limiting the development of electrochemical hydrolysis. Doping metallic elements and building layered structures have been considered effective strategies for improving the electrocatalytic performance of the materials. Herein, we report flower-like nanosheet arrays of Mn-doped-NiMoO4/NF (where NF is nickel foam) on nickel foam by a two-step hydrothermal method and a one-step calcination method. The doping manganese metal ion not only modulated the morphologies of the nickel nanosheet but also altered the electronic structure of the nickel center, which could be the result of superior electrocatalytic performance. The Mn-doped-NiMoO4/NF electrocatalysts obtained at the optimum reaction time and the optimum Mn doping showed excellent OER activity, requiring overpotentials of 236 mV and 309 mV to drive 10 mA cm-2 (62 mV lower than the pure NiMoO4/NF) and 50 mA cm-2 current densities, respectively. Furthermore, the high catalytic activity was maintained after continuous operation at a current density of 10 mA cm-2 of 76 h in 1 M KOH. This work provides a new method to construct a high-efficiency, low-cost, stable transition metal electrocatalyst for OER electrocatalysts by using a heteroatom doping strategy.

Interfacial construction of P25/Bi2WO6 composites for selective CO2 photoreduction to CO in gas-solid reactions.

Photocatalysis provides an attractive approach to convert CO2 into valuable fuels, which relies on a well-designed photocatalyst with good selectivity and high CO2 reduction ability. Herein, a series of P25/Bi2WO6 nanocomposites were synthesized by a simple one-step in situ hydrothermal method. The formation of a heterojunction between Bi2WO6, which absorbs visible light, and P25, which absorbs ultraviolet light, expands the utilization of sunlight by the catalysts, and consequently, leads to a remarkably enhanced CO2 selective photoreduction to CO. The maximum CO yield of the P25/Bi2WO6 heterojunction under simulated solar irradiation was 15.815 µmol g-1 h-1, which was 4.04 and 2.80 times higher than that of pure P25 and Bi2WO6, respectively. Our investigations verified a Z-scheme charge migration mechanism based on various characterization techniques between P25 and Bi2WO6. Furthermore, in situ DRIFTS uncovered the related reaction intermediates and CO2 photoreduction mechanism. Our work sheds light on investigating the efficacious construction of Bi2WO6-based hybrids for light-driven photocatalysis.

Tomentosin suppressed M1 polarization via increasing MERTK activation mediated by regulation of GAS6.

ETHNOPHARMACOLOGICAL RELEVANCE: Xanthium sibiricum Patrin ex Widder (X. sibiricum) are widely used traditional herbal medicines for arthritis treatment in China. Rheumatoid arthritis (RA) is characterized by progressive destructions of joints, which is accompanied by chronic, progressive inflammatory disorder. According to our previous research, tomentosin was isolated from X. sibiricum and revealed anti-inflammatory activity. However, the potential therapeutic effect of tomentosin on RA and the anti-inflammatory mechanism of tomentosin remain to be clarified. The present study lays theoretical support for X. sibiricum in RA treatment, also provides reference for further development of X. sibiricum in clinic. AIM OF THE STUDY: To investigate the effect of tomentosin in collagen-induced arthritis (CIA) mice and reveal its underlying mechanism. MATERIALS AND METHODS: In vivo, tomentosin (10, 20 and 40 mg/kg) was given to CIA mice for seven consecutive days, to evaluate its therapeutic effect and anti-inflammatory activity. In vitro, THP-1-derived macrophages were used to verify the effect of tomentosin on inflammation. Then, molecular docking and experiments in vitro was conducted to predict and explore the mechanism of tomentosin inhibiting inflammation. RESULTS: Tomentosin attenuated the severity of arthritis in CIA mice, which was evidenced by the swelling of the hind paws, arthritis scores, and pathological changes. Particularly, tomentosin effectively reduced the ratio of M1 macrophage and TNF-α levels in vitro and vivo. Then, molecular docking and experiments in vitro was carried out, indicating that tomentosin inhibited M1 polarization and TNF-α levels accompanied by the increase of MERTK and up-regulated GAS6 levels. Moreover, it has been proved that GAS6 was necessary for MERTK activation and tomentosin could up-regulate GAS6 levels effectively in transwell system. Further mechanistic studies revealed that tomentosin suppressed M1 polarization via increasing MERTK activation mediated by regulation of GAS6 in transwell system. CONCLUSION: Tomentosin relieved the severity of CIA mice by inhibiting M1 polarization. Furthermore, tomentosin suppressed M1 polarization via increasing MERTK activation mediated by regulation of GAS6.

A Mid-term Follow-up Study on the Reimplantation of Autoclaved Femoral and Tibial Components as Spacers for Treating Infected Total Knee Arthroplasty.

OBJECTIVE: Infection after total knee arthroplasty (TKA) is a rare but devastating complication. Different types of spaces have been used in two-stage revision. The study aimed to evaluate the effect of autoclaved femoral and tibial components as spacers for treating periprosthetic infections after TKA. METHODS: A retrospective study was performed for 13 patients (five males, eight females) with a mean age of 69 ± 6 (range, 57-80) years and suffering from periprosthetic infection after TKA. They were treated with unconventional two-stage revision from May 2008 to June 2017. In the first-stage surgery, the autoclaved femoral and tibial components were reimplanted with a new liner as a spacer after a thorough debridement. After 4-6 months, the second-stage surgery was performed according to the patients' requirements. The knee society score (KSS) and knee range of motion (ROM) were assessed before and after surgery. The reinfection rate was calculated. RESULTS: The mean duration of follow-up was 5.7 ± 2.1 (range, 3.1-8.8) years. Culture-positive infections comprised 69% of the cohort. All patients were able to walk 24 h after the first stage surgery, and the knee ROM could reach 90° in 1 week. Two patients (15.4%) experienced an infection recurrence. One patient was reinfected 1 year after the first stage surgery. Another patient developed reinfection 3 years after surgery but did not choose re-revision and died of pneumonia. Only one patient underwent the second stage revision. The remaining 10 patients refused to receive a new prosthesis. At the time of the final follow-up, six patients had slight pain in the knee while walking, and one patient required crutches to walk. There were no signs of prosthesis dislocation, rupture, deep vein thrombosis, pulmonary embolism, or delayed wound healing. No radiolucent lines or osteolysis were found. The mean KSS improved from 51 ± 10 (range, 35-63) points preoperatively to 79 ± 5 (range, 60-85) points at the final follow-up. The average ROM before and after the first stage surgery were 62° ± 29° (range, 10°-100°) and 104° ± 9° (range, 90°-120°) (t = 4.659, P < 0.01) respectively. The infection control rate was 84.6%. CONCLUSION: Reimplantation of the autoclaved original femoral and tibial components as an articulating spacer during the first stage surgery is a valuable addition for treating an infected TKA.

The androgen receptor in hormone-refractory prostate cancer.

Advanced prostate cancer is responsive to hormone therapy that interferes with androgen receptor (AR) signalling. However, the effect is short-lived, as nearly all tumours progress to a hormone-refractory (HR) state, a lethal stage of the disease. Intuitively, the AR should not be involved because hormone therapy that blocks or reduces AR activity is not effective in treating HR tumours. However, there is still a consensus that AR plays an essential role in HR prostate cancer (HRPC) because AR signalling is still functional in HR tumours. AR signalling can be activated in HR tumours through several mechanisms. First, activation of intracellular signal transduction pathways can sensitize the AR to castrate levels of androgens. Also, mutations in the AR can change AR ligand specificity, thereby allowing it to be activated by non-steroids or anti-androgens. Finally, overexpression of the wild-type AR sensitizes itself to low concentrations of androgens. Therefore, drugs targeting AR signalling could still be effective in treating HRPC.

Cementless revision for infected hip arthroplasty: an 8.6 years follow-up.

OBJECTIVE: To investigate cementless revision for postoperative infection after total hip arthroplasty (THA). METHODS: From November 1997 to December 2009, 10 patients (10 hips; four males, six females) of mean age 58 years (36-73 years) with infection after THA were treated. Six of the 10 hips underwent revision total hip arthroplasty, two only received new acetabular components and two underwent stem revision. One-stage revision was performed in six cases and two-stage revision in four. Consecutive radiographs were compared to evaluate component conditions. Harris hip scores were determined before surgery and at final follow-up. Erythrocyte sedimentation rate and C-reactive protein were assessed. RESULTS: All patients were followed up for a mean duration of 8.6 years (6.5-15.6 years). The mean Harris hip score improved from 35 (18-63) points preoperatively to 89 (60-99) points at final follow-up. No re-infection occurred. Femoral component exsertion was occurred in one asymptomatic patient. Hip joint pain resolved in seven cases; three patients had mild pain when walking long distances. At final follow-up, six patients still had slight limps. Heterotopic ossification developed in two hips. Mean polyethylene liner wear was 0.08 mm per year at final follow-up. Deep vein phlebothrombosis and nerve injury did not occur. CONCLUSION: One- or two-stage revisions using cementless prosthesis can produce satisfactory clinical outcomes in patients with infection after THA. Whether the original prosthesis can be partially retained when attached tightly to the femur or acetabular bone needs further investigation.

Effects of Sox9 gene therapy on the healing of bone-tendon junction: An experimental study.

BACKGROUND: Sox9 is an operon that positively regulates the transcription of type II collagen. The generation of type II collagen plays a critical role in the healing process of the bone-tendon junction (BTJ). MATERIALS AND METHODS: Sox9 was injected into an established bone-tendon healing model in order to observe its effect on the healing by determining the biomechanical properties of the BTJ. In addition, the recombinant adenovirus Sox9 was used to transduce the animal model samples and in vivo observations of the effect of the adenovirus-mediated Sox9 transduction as well as its promotion of the healing properties were made. RESULTS: Sox9 was not only able to promote the healing, but also increased the biomechanical strength. The recombinant Sox9 delivered by adenoviral vector can be expressed at a high level in the damaged tissues of the bone-tendon junction, which can stimulate the production of type II collagen and improve the healing of the BTJ. CONCLUSIONS: Based on the results of this study, we considered that gene therapy may be applicable in the healing process of the bone-tendon junction.

[Biomechanical research of SOX9, CTGF in bone tendon junction healing].

AIM: To investigate the biomechanical effect of SOX9, CTGF in bone tendon junction healing. METHODS: 36 adult New Zealand rabbits were randomly divided into A, B and C groups(each group were 12 rab-bits). Group A with SOX9 inject into bone tendon junction;Group B with CTGF inject into bone tendon junction; C group was inject nothing. The animal of three groups were used surgery and all of the animals were faced with biomechanical test after 4 weeks, 8 weeks and 12 weeks; The result were used statistical analysis. RESULTS: group A and group B's cross-sectional area were lower than group C during 4 weeks, 12 weeks postoperative; there were statistical difference between each groups ( P < 0. 05). group Aand group B's pulled off load and ultimate tensile stress were higher than group C during 4 weeks, 8 weeks, 12 weeks postoperative, the result were statistical difference between each groups ( P < 0. 05). CONCLUSION: SOX9 and CTGF group can not only promote the early bone ten-don junction healing, But also increased the biomechanical strength of bone tendon junction.