Search

Microwave absorption performance and mechanisms of core–shell SiO2@C and hollow carbon nanospheres with different sizes.

Two unique polyoxometalate (POM)-encapsulated tubular materials with the formula K(H

Three POM-based coordination polymers with 1,3,5-tris(1-imidazolyl)benzene have been synthesized. 1 exhibits a rare 3,6-connected pyr topology; 2 and 3 reveal 3D hydrogen-bonded structures with good proton conductivity.

Traditional stepwise approach usually adjusts the treatment regimen based on changes in asthma symptoms and severity to achieve good asthma control. However, due to the generalized heterogeneity and complexity of asthma, its therapeutic efficacy in difficult-to-treat asthma is limited. Recently, a precision medicine approach based on the identification and intervention of treatable traits of chronic airway disease has been proposed and appears to be of greater benefit to asthmatics. We reported a 71-year-old male with uncontrolled asthma and multiple exacerbations over the past year. He complained of persistent dyspnea despite high-dose of inhaled corticosteroids plus other controllers. Does this patient have some potential treatable traits contributing to difficult-to-treat asthma? Through a multidimensional assessment of three domains including pulmonary, extrapulmonary, and behavioral/risk factors, 15 treatable traits were identified in the patient, mainly including airflow limitation, eosinophilic airway inflammation, small airway dysfunction, exacerbation prone, dilated cardiomyopathy, diabetes mellitus, inhaler device polypharmacy, smoking, and the absence of an asthma action plan. After targeted treatment for these treatable traits, the patient experienced significant improvement in dyspnea and he could maintain good asthma control with low-dose inhaled corticosteroids and long-acting β2-agonist. This study shows that, in response to the limitation of a stepwise approach to therapy, treatable traits is a new strategy where patients are individually assessed for a specified set of treatable problems, and an individualized treatment program is developed and implemented based on this multidimensional assessment, especially for difficult-to-treat asthma.

Background Data on treatable traits (TTs) in different populations are limited. Objective To assess TTs in elderly patients with asthma and compare them to younger patients, to evaluate the association of TTs with future exacerbations, and to develop an exacerbation prediction model. Methods We consecutively recruited 521 participants at West China Hospital, Sichuan University based on the Australasian Severe Asthma Network, classified as elderly (n = 62) and nonelderly (n = 459). Participants underwent a multidimensional assessment to characterize the TTs and were then followed up for 12 months. TTs and their relationship with future exacerbations were described. Based on the TTs and asthma control levels, an exacerbation prediction model was developed, and the overall performance was externally validated in an independent cohort. Results A total of 38 TTs were assessed. Elderly patients with asthma had more chronic metabolic diseases, fixed airflow limitation, emphysema, and neutrophilic inflammation, whereas nonelderly patients with asthma exhibited more allergic characteristics and psychiatric diseases. Nine traits were associated with increased future exacerbations, of which exacerbation prone, upper respiratory infection–induced asthma attack, cardiovascular disease, diabetes, and depression were the strongest. A model including exacerbation prone, psychiatric disease, cardiovascular disease, upper respiratory infection–induced asthma attack, noneosinophilic inflammation, cachexia, food allergy, and asthma control was developed to predict exacerbation risk and showed good performance. Conclusions TTs can be systematically assessed in elderly patients with asthma, some of which are associated with future exacerbations, proving their clinical utility of evaluating them. A model based on TTs can be used to predict exacerbation risk in people with asthma.

Al0.15Nb0.15Ti0.7O2 ceramics were synthesized via strong magnetic field alignment at 6 T and sintered under a nitrogen atmosphere. A ceramic prepared at 6 T by polishing it along the direction parallel to the magnetic field (parallel-6 T) with a brick-layered microstructure shows a colossal permittivity of er ≈ 8.2 × 104 and a low dielectric loss of tan δ ≈ 0.019 at 1 kHz, with impedance spectroscopy suggesting that the colossal permittivity is attributed to internal barrier layer capacitor effects. XRD results indicate that approximately 90 % of the grains are aligned along the magnetic field with a tilt angle less than 10°. The average width and length of the grains for parallel-6 T ceramics are 4.1 μm and 9.4 μm. Compared to non-magnetically treated Al0.15Nb0.15Ti0.7O2 ceramics, the high grain boundary resistance (1.6 × 108 Ω cm) of the parallel-6 T ceramic can be responsible for this low dielectric loss.

Background: GnRHa treatment was established for improving final adult height (FAH) in children presenting with Idiopathic central precocious puberty (ICPP) up to age 8, while several controversies remained for older age groups. The primary objective was to evaluate whether boys diagnosed with ICPP over 9 years of chronological age (CA) could achieve a height benefit from GnRHa treatment.Methods: We retrospectively evaluated the medical records of 23 boys treated for idiopathic central precocious puberty between January 2018 and January 2021 at Jiangsu Children's Medical Center. All patients started treatment with intramuscular depot GnRHa at a dose of 80-100 μg/kg, followed by continuous intramuscular injection every 28 days at a dose of 60-80 μg/kg. The hormonal parameters, bone age/chronological age ratio, FAH, growth velocity (GV), tanner staging and body mass index (BMI) were assessed during the treatment period.Results: After one course of treatment (3 months), the basal FSH and testosterone levels were reduced, while the basal LH value was not significantly changed compared with those before treatment. Furthermore, the mean BA/CA ratio reduction was statistically significant at month 12. The mean PAH following administration of GnRHa after 12 months was statistically improved compared with those at baseline. In addition, the clinical sign of puberty and GV were significantly improved and the BMI remained unchanged as desired at month 12.Conclusions: This analysis highlighted the positive outcome on the decrease in the rate of bone maturation, with a favorable effect on progression of clinical signs of puberty. Furthermore, our study confirmed improved PAH even in the older children at onset of treatment (ages 9-10), emphasizing the importance of personalized treatment in such population.

(1-xwt)Bi0.0025Nb0.0025Ti0.995O2-xwtBi2Ti4O11 composite ceramics with high permittivity were fabricated by a conventional sintering method. The sintering temperature was decreased from 1300 °C to 1130 °C, and the grain size was reduced from ~2.6 μm to ~1.5 μm by the addition of Bi2Ti4O11 phase. When xwt = 0.2, the breakdown strength was increased from 1 kV/cm to 13 kV/cm while preserving high permittivity (ϵ' ~ 1100). Microstructure, I–V behavior, and Impedance spectroscopy studies demonstrated that the enhanced breakdown strength and excellent dielectric properties were attributed to the small grain size and the highly resistant grain boundaries. These advantages, together with its excellent DC bias stability of dielectric constant (0–1050 V/cm), give the composites a great potential in rutile TiO2-based high voltage MLCC applications.

Novel FeB/B4C nanowire composite was synthesized by a catalyst-assisted process. The results showed that the composite contains mainly B4C nanowires with diameters under 100 nm and FeB nanoparticles with a size of ~50 nm. Reflection loss value of the FeB/B4C nanowire-paraffin composite reaches −13.6 dB at 8.2 GHz when the thickness is 3.5 mm, and absorption bandwidth with RL below −10 dB reaches 1.6 GHz (7.5–9.1 GHz). The minimum RL value reaches −50.8 dB at 17.4 GHz when the thickness is 4.8 mm, with the absorption bandwidth increased to 2.4 GHz (15.6–18.0 GHz). Electromagnetic parameters of the composite were studied to understand its excellent microwave absorbing properties.

In mainland China, there remains a shortage of pediatric drugs. The Chinese government has recently launched policies and incentives to encourage pediatric drug development and clinical trials. However, data on the characteristics or development trends of these trials are limited. In this review, we extracted source data from the Chinese Clinical Trials Registry and Information Transparency Platform and systematically reviewed the pediatric clinical trials conducted in mainland China from 2009 to 2020, a comprehensive process evaluation of the pediatric drug clinical trials development in the past decade, providing data support to policy makers and industry stakeholders. We included 487 pediatric clinical trials. Over the past decade, the number of pediatric trials has increased, especially since 2016. The most common therapeutic areas were infectious diseases (n = 108, 22.2%), agents for preventive purpose (n = 99, 20.3%), and neurological and psychiatric diseases (n = 71, 14.6%). The number of clinical trials involving epilepsy (39, 10.1%), asthma (33, 8.5%), and influenza (24, 6.2%) were the highest. The distribution of leading institutions is unbalanced in mainland China, with most units in East China (34.0%) and few in Southwest China (6.9%). China has made progress in improving the research and development environment of pediatric drugs and increasing pediatric trials. However, a wide gap in pediatric drug development and clinical trials quality exists between China and the developed countries. The pharmaceutical industry in China has faced grim setbacks, including study duplication, lack of innovation, poor research design, and unbalanced resource allocation. Thus, we suggest that the Chinese government should adjust their policies to improve innovation and clinical design capacity, and optimize resource allocation between regions.

In this paper, electrical and photoluminescence properties of the (Bi0.5−x/0.94Erx/0.94Na0.5)0.94Ba0.06TiO3 lead-free ceramics with x ≤ 0.02 were investigated. All ceramics have pure perovskite phase. Lattice distortion induced by the doping of Er3+ was observed. The ceramics show average grain sizes around 0.6–1.0 µm. The doped ceramics exhibit decreased dielectric constant, which are still higher than 1200 at room temperature. Curie temperatures of the samples do not fluctuate dramatically with changing the doping amounts, which are around 250 °C. The piezoelectric constant d33 is closely related to the Er3+ content. Under an excitation of 487 nm, the ceramics exhibit visible luminescent emissions at 528 nm (green), 548 nm (green), and 670 nm (red).

Developing highly efficient electromagnetic wave absorbers with high reflection loss, wide absorption bandwidth, strong thermal stability and light weight is still a challenge at present. Herein, we creatively developed ultralight B4C-based hybrid nanowires as novel absorbers. The synthesized B4C nanowires with abundant stacking faults exhibit excellent microwave absorption properties. Heterointerface engineering of the B4C nanowires was realized by introducing SiC nanoparticles into the nanowires through a multi-step vapor–liquid–solid process. The SiC embedded B4C hybrid nanowires with a unique worm-like structure achieved a broadband effective absorption up to 4.7 GHz (13.3–18 GHz) at 2.5 mm and a broadband absorption up to 4.9 GHz (7.4–12.3 GHz) at 3.7 mm, which covered the whole X-band. Furthermore, the optimized reflection loss value became −50.81 dB at 11.9 GHz at 3.3 mm thickness, almost three times that of the B4C nanowires. The significantly improved microwave absorption ability primarily resulted from the enhanced dual dielectric relaxation, that is, electric dipole polarization and interfacial polarization. The low reflection loss values and wide absorption bandwidth of the SiC/B4C hybrid nanowires, together with their high temperature stability and light weight, make them a good candidate as highly efficient electromagnetic wave absorbers under harsh conditions.

Background: For advanced non-small cell lung cancer (NSCLC) patients, first-line chemotherapy is the main treatment in the clinic despite its efficacy is limited and adverse effects are always inescapable. Ginsenoside Rg3, an anti-cancer active ingredient by suppressing angiogenesis, has been increasingly widely used as an adjuvant in first-line chemotherapy for advanced NSCLC to optimize treatment in China. However, no comprehensive meta-analyses have been conducted to estimate the efficacy and safety of the therapy combining ginsenoside Rg3 and first-line chemotherapy in advanced NSCLC patients.Methods: Randomized controlled trails using a combination of first-line chemotherapy and ginsenoside Rg3 for advanced NSCLC patients were searched and selected from six databases. The Cochrane Risk of Bias tool was used to assessed the quality of these selected original researches. And we used Review Manager 5.3 and STATA to analyze the data.Results: Twenty-two RCTs that matched our selection criteria with a number of 2202 patients were included in our review. The results showed that compared with first-line chemotherapy alone, the combination of ginsenoside Rg3 and first-line chemotherapy could better improve the objective response rate (ORR) (RR [95% CI], 1.44 [1.27, 1.63], p < 0.00001 ), the disease control rate (DCR) (RR [95% CI], 1.24 [1.12, 1.38], p < 0.0001), karnofsky performance status (KPS) (RR [95% CI], 1.62 [1.42, 1.84], p < 0.00001), one-year survival rate (RR [95% CI], 1.49 [1.08, 2.06], p = 0.01), two-year survival rate (RR [95% CI], 6.22 [1.68, 22.95], p = 0.006), weight change (RR [95% CI], 1.31 [1.04, 1.66], p = 0.02), and higher reduce the VEGF levels (RR [95% CI], -2.21 [-4.03, -0.38], p = 0.02), the incidence of gastrointestinal reactions (RR [95% CI], 0.66 [0.47, 0.93], p = 0.02) and bone marrow suppression (RR [95% CI], 0.43 [0.30, 0.61], p < 0.00001).Conclusion: Ginsenoside Rg3 can enhance drug efficacy and reduce drug-induced toxicity from chemotherapy. These findings provide helpful information for clinicians indicating that a therapy combined of ginsenoside Rg3 and first-line chemotherapy may be used to optimal the treatment of advanced NSCLC.

This is the first comprehensive review on inherent anisotropic features of transition metal diboride (MB 2 ) and their implementation for tailoring the microstructure and properties of MB 2 -based Ultra-high temperature Ceramics (UHTCs). The emphasis is on the processing approaches, microstructures, and properties of self-reinforced and/or textured MB 2 -based composites with elongated MB 2 grains. The crystal structure characteristics and grain growth behaviour of MB 2 are also critically reviewed. Benefiting from the tailored microstructure, the MB 2 -based ceramics exhibit some improved properties. Considering the success of Si 3 N 4 ceramics in the field of structural ceramics, it is expected that the potential MB 2 -based ceramic composites with abundant elongated MB 2 grains, textured structures, and controlled grain boundaries would possess improved fracture toughness, thermal shock resistance, and reliable high-temperature properties, which are desired for their practical applications. Accordingly, microstructure designing and tailoring provide an important perspective for the future development of UHTCs.

A highly stable electrochemical acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs) was developed simply by adsorption of AChE on chitosan (CS), TiO2 sol-gel, and reduced graphene oxide (rGO) based multi-layered immobilization matrix (denoted as CS@TiO2-CS/rGO). The biosensor fabrication conditions were optimized, and the fabrication process was probed and confirmed by scanning electron microscopy and electrochemical techniques. The matrix has a mesoporous nanostructure. Incorporation of CS and electrodeposition of a CS layer into/on the TiO2 sol-gel makes the gel become mechanically strong. The catalytic activity of the AChE immobilized CS@TiO2-CS/rGO/glassy carbon electrode to acetylthiocholine is significantly higher than those missing any one of the component in the matrix. The detection linear range of the biosensor to dichlorvos, a model OP compound, is from 0.036μM (7.9 ppb) to 22.6μM, with a limit of detection of 29nM (6.4 ppb) and a total detection time of about 25min. The biosensor is very reproducibly and stable both in detection and in storage, and can accurately detect the dichlorvos levels in cabbage juice samples, providing an efficient platform for immobilization of AChE, and a promisingly applicable OPs biosensor with high reliability, simplicity, and rapidness.

A large amount of multi-walled carbon nanotubes (MWCNTs) (10 vol%) were uniformly and intimately dispersed within ZrB 2 ceramic matrix using an aqueous hetero-coagulation approach followed by spark plasma sintering (SPS) at 1700 °C. Addition of MWCNTs inhibited grain growth, increased the relative density from 89% to 97%, and resulted in a composite with a fine, rather pore-free and uniform microstructure. Structural evolution of MWCNTs in the ZrB 2 matrix was further studied after SPS sintering at 1900 °C by XRD, Raman, scanning electron microscopy and TEM. When sintered at 1700 °C, the MWCNTs remained intact with their tubular one-dimensional structure though experiencing an expected radial elastic compression/buckling due to thermal misfit residual stresses. When sintered at 1900 °C, their unzipping into graphite nanoribbons was observed. For practical applications, MWCNTs content should however be lowered to prevent their agglomeration during grain growth.

Aims Arbuscular mycorrhizal fungi (AMF) are symbiotic partners of many invasive plants, however, it is still unclear how AMF contribute to traits that are important for the successful invasion of their host and how environmental factors, such as nutrient conditions, influence this. This study was to explore the effects of Glomus versiforme (GV) and Glomus mosseae (GM) on the growth and disease resistance of the invasive plant Wedelia trilobata under different nutrient conditions. Methods and results We found that GV and GM had higher root colonization rates resulting in faster W. trilobata growth under both low-N and low-P nutrient conditions compared to the normal condition. Also, the colonization of W. trilobata by GV significantly reduced the infection area of the pathogenic fungus Rhizoctonia solani under low-N conditions. Conclusions These results demonstrated that AMF can promote the growth and pathogenic defence of W. trilobata in a nutrient-poor environment, which might contribute to their successful invasion into certain type of habitats. Significance and impact of the study In this study, we report for the first time that AMF can promote growth and disease resistance of W. trilobata under nutrient-poor environment, which contribute to a better understanding of plant invasion.

To explore the mechanisms of 5-aminolevulinic acid (ALA)-improved plant salt tolerance, strawberries (Fragaria × ananassa Duch. cv. 'Benihoppe') were treated with 10 mg l-1 ALA under 100 mmol l-1 NaCl stress. We found that the amount of Na+ increased in the roots but decreased in the leaves. Laser scanning confocal microscopy (LSCM) observations showed that ALA-induced roots had more Na+ accumulation than NaCl alone. Measurement of the xylem sap revealed that ALA repressed Na+ concentrations to a large extent. The electron microprobe X-ray assay also confirmed ALA-induced Na+ retention in roots. qRT-PCR showed that ALA upregulated the gene expressions of SOS1 (encoding a plasma membrane Na+ /H+ antiporter), NHX1 (encoding a vacuolar Na+ /H+ antiporter) and HKT1 (encoding a protein of high-affinity K+ uptake), which are associated with Na+ exclusion in the roots, Na+ sequestration in vacuoles and Na+ unloading from the xylem vessels to the parenchyma cells, respectively. Furthermore, we found that ALA treatment reduced the H2 O2 content in the leaves but increased it in the roots. The exogenous H2 O2 promoted plant growth, increased root Na+ retention and stimulated the gene expressions of NHX1, SOS1 and HKT1. Diphenyleneiodonium (DPI), an inhibitor of H2 O2 generation, suppressed the effects of ALA or H2 O2 on Na+ retention, gene expressions and salt tolerance. Therefore, we propose that ALA induces H2 O2 accumulation in roots, which mediates Na+ transporter gene expression and more Na+ retention in roots, thereby improving plant salt tolerance.

To explore the mechanisms of 5-aminolevulinic acid (ALA)-improved plant salt tolerance, strawberries (Fragaria × ananassa Duch. cv. 'Benihoppe') were treated with 10 mg l

A sensitive, accurate, free of oxygen interference electrochemical sensing approach was developed in this study for H2O2 level, an important parameter in clinical, biological and environmental fields. A boron-doped diamond (BDD) electrode was modified with mesoporous platinum (MPrPt) by electrodeposition of Pt–Cu alloy and anodic dissolution of Cu from the alloy, followed by the electropolymerization of a poly(pyrrole-3-carboxylic acid) (PPy3C) and polypyrrole (PPy) (PPy3C: PPy = 4:1, molar ratio) copolymer. SEM micrographs revealed that MPrPt irregularly spreads on the BDD surface as ~ 100 nm mesoporous and snow-flake-like nanoclusters, with a pore size of 10 ~ 15 nm, and a trace amount of remnant Cu. The resulting Pt roughness factor and the effective surface area of the MPrPt/BDD were significantly larger, and its charge-transfer resistance was much smaller than those of the Pt nanoparticle modified BDD electrode. The PPy3C–PPy/MPrPt/BDD electrode exhibited very much sensitive, selective, precise, accurate, stable, reproducible, and a wide linear range of H2O2 responses at neutral pH under ambient condition, with similar sensitivity and S/N ratio to those under nitrogen protection. The limit of detection (LOD) for H2O2 was 2 μM, with linearity range of 5 μM ~ 49 mM (4 orders of magnitude). The BDD substrate, MPrPt, and the PPy3C–PPy copolymer together exerted a synergic effect to the prominent sensing performance. The detection was free from endogenous oxygen interference, one of the most critical issues in microanalysis, in vivo monitoring and field applications.

This paper uses the fuzzy neural network technology to establish AMT ramp adaptive system. When driving on a vehicle ramp, the shift point is modified. In the uphill, the forced downshift ensures that the vehicle has sufficient power and effectively avoids frequent shifting; In the downhill, to avoid the high speed and high grade of the vehicle, the brake must be used for a long time to stabilize the vehicle speed, which may cause the brake drum or the brake disc to overheat, thus causing an accident.

Despite of good oxidation resistance and ablation resistance, challenge to densify and tendency to loss high temperature (H.T.) strength have limited its potential applications in aerospace for HfB2–SiC ceramic. In this work, dense HfB2–SiC ceramic with improved H.T. flexural strength was prepared using WC as sintering aid. Pure HfB2–SiC ceramic exhibited creep deformation at 1600 °C with measured strength value of 389 ± 82 MPa, whereas WC doped sample showed much higher flexural strength of 658 ± 69 MPa with linear elastic behavior prior to fracture. In addition to clean grain boundary, the addition of 5 vol.%WC into HfB2–SiC ceramic promoted the formation of fine (Hf,W)B2, (Hf,W)C and WB precipitates. This combinative effect is responsible for its excellent H.T. mechanical property of WC doped HfB2–SiC ceramic.

A highly stable electrochemical acetylcholinesterase (AChE) biosensor for detection of organophosphorus pesticides (OPs) was developed simply by adsorption of AChE on chitosan (CS), TiO

To study the effectiveness of surgical dorsal endoscopic rhizotomy for the treatment of facetogenic chronic low back pain.From April 2011 to November 2011, 58 patients who were diagnosed with lumbar facetogenic chronic low back pain (CLBP) and thereafter experienced80% reliefs of pain with two comparative lumbar medial branch blocks were recruited in the study. Of those 58 patients, 45 cases (the operation group) received dorsal endoscopic rhizotomy, and the remaining 13 cases (the conservative group) received conservative treatment. Patients' preoperative and postoperative VAS score, percentage of pain relief and the MacNab score were analyzed and compared. Anatomic variations and any possible complications were recorded.In the operation group, VAS scores of pain (low back/referred) at any time point postoperatively were significantly lower than that before MBB (P0.05), which, however, showed no significant difference as compared to the scores after MBB (P0.05). In the conservative group, VAS scores of pain (low back/referred) at any time point postoperatively with conservative treatment decreased significantly compared with that before MBB (P0.05) and were significantly higher than that after MBB (P0.05). Percentage of pain relief in the operation group at any time point postoperatively were significantly higher than that in the conservative group (P0.01). The MacNab scores of 1 year follow-up in the operation group were higher than that in the conservative group. In addition, four separate newly identified anatomical variations of medial branch anatomy were observed and reported.Dorsal endoscopic rhizotomy is safe and effective for the facetogenic CLBP, and can achieve better clinical outcome than the conservative treatment.

In this study, the isolation of an endophytic fungus from the leaves of the medicinal herb adlay (Coix lacryma-jobi L. var. ma-yuen Stapf) is reported for the first time. The fungus produced Triolein (trioleoylglycerol), a major constituent of triacylglycerols (TAGs) of adlay, in rice medium under shake-flask and bench-scale fermentation conditions. The fungus was identified as Gibberella moniliformis (Fusarium verticillioides) by its morphology and authenticated by ITS analysis (ITS1 and ITS2 regions and the intervening 5.8S rDNA region). Triolein was identified by HPLC-ELSD coupled with APCI-MS and confirmed through comparison with authentic standard. The concentration of triolein produced by G. moniliformis AH13 reached 2.536 ± 0.006 mg/g dry weight of mycelium. Moreover, the EtOAc extract of G. moniliformis AH13 showed strong antitumor activity against four types of tumor cells (A549, HCT116, MDA-MB-231, and SW1990). These results suggest that G. moniliformis AH13 in adlay has significant scientific and industrial potential to meet the pharmaceutical demands and sustainable energy requirements for TAGs in a cost-effective, easily accessible, and reproducible way and is also a potential novel source of natural antitumor bioactive agents.

Binderless WC ceramics were prepared by reactive spark plasma sintering, using tungsten trioxide, tungsten and carbon black as the starting materials. Phase assemblages and microstructure of the as-sintered ceramics were investigated. It was found that graphite existed as an impurity phase due to the volatilization of WO 3 , and W could compensate for the WO 3 loss to form WC with a single phase. Benefiting from the enhanced sinterability, WC ceramics with high relative density and good hardness could be obtained at temperature as low as 1500 °C.

A solid state reaction of ZrH2, Si3N4 and B4C has been proposed to synthesize machinable ZrB2–SiC–BN composites. Dense ZrB2–SiC–BN composites with fine grain size and homogeneous microstructure were fabricated via spark plasma sintering at 1900 °C in vacuum. The kinetics of the reaction process was studied with XRD results. SEM and TEM results showed that the in-situ formed BN phase was composed of micro-sized intergranular and nano-sized intragranular h-BN particles. The influences of the BN content on the mechanical properties as well as the thermal conductivities of the composites were studied. The composites that contained >20 vol% BN exhibited excellent machinability and high strength.

ZrB 2 powders were synthesized by mechanical alloying (MA) of the mixture of elemental Zr and B powders using WC vial and balls. The effect of the initial composition, the milling time on MA and the phase changes during MA were investigated. Well-crystallized ZrB 2 powder with micrometer size was received by directly ball milling the Zr/B powder mixtures. Nanocrystalline ZrB 2 powders were received by adding ZrB 2 powder into the Zr/B powder mixture as a diluent to exhibit the ignition of the raw powders. The phase transformation and the morphology of the powders were characterized by XRD analysis and SEM and TEM observation.

ZrB 2 –SiC–ZrN composites were fabricated by reactive hot pressing using Zr, Si 3 N 4 , and B 4 C powders as starting materials. Sintering was conducted at temperatures of 1800 to 2000 °C under a load of 20 MPa in Ar atmosphere. The composite was densified at 2000 °C. The in situ formed BN flakes which distributed uniformly at the grain boundaries were identified by X-ray diffraction and scanning electron microscopy. The formation of h- BN phase and its effect on the mechanical properties of the composite are discussed.

Zirconium carbide and hafnium carbide ceramics were prepared by reactive spark plasma sintering, using oxides and carbon black as the raw materials. The phase and microstructure evolution during the sintering process was investigated. It was found that ZrC and HfC powder intermediates were formed at 1750 and 1800 °C, respectively. Due to the high sinterability of the in situ formed carbide particles, samples with a fine microstructure could be densified at a relatively low temperature.

ZrB2–SiC–BN composites were fabricated from a powder mixture of ZrH2, Si3N4 and B4C via reactive hot pressing (RHP) and reactive spark plasma sintering (R-SPS). The phase composition, density, microstructure and mechanical properties of the final products were studied and compared. The sample fabricated by the R-SPS process showed higher density, flexural strength and fracture toughness and had a more homogeneous microstructure compared to the one fabricated by the RHP process.

Dense, highly textured ZrB2 and ZrB2–MoSi2 ceramics were fabricated via a strong magnetic field alignment method followed by spark plasma sintering. Unlike with the previous studies, which only focused on the alignment of single-phase particles, both ZrB2 and MoSi2, which exhibited a magnetic anisotropy, have been aligned in this study. The alignment of MoSi2 in the same direction of ZrB2 enhanced the degree of orientation of ZrB2, decreased the grain size, but increased the aspect ratio of the platelet ZrB2 grains. The microstructure and anisotropic mechanical properties as well as the oxidation resistance in different directions were discussed.

We investigate the high-temperature compressive deformation behavior of a novel, fully dense and structurally uniform, 20 vol% multiwalled carbon nanotube (MWCNT)–α-Al2O3 matrix hybrid, which has a strong room-temperature interfacial shear resistance (ISR) and a unique MWCNT-concentrated grain-boundary (GB) structure. We realized a perfect plastic deformation at 1400°C and a rather high initial strain rate of 10−4 s−1 by a low ~30 MPa flow stress, which is contrary to the strain hardening response of fine-grain monolithic Al2O3. This unique performance in CNT–ceramic system in compression is explained as follows: the concentrated network of individual MWCNTs perfectly withstands the high-temperature and shear/compressive forces, and strongly preserves the nanostructure of Al2O3 matrix by preventing the dynamic grain growth, even during a large ~44% deformation. Furthermore, the presence of large amount of radially soft/elastic, highly energy-absorbing MWCNTs in the GB and specially multiple junction areas, and a potentially weak 1400°C-ISR, could greatly facilitate the GB sliding process (despite the hybrid's strong room-temperature ISR), as evidenced by the formation of some submicrometer-scale MWCNT aggregates in GB area, the equiaxed grains and dislocation-free nanostructure of the deformed hybrid. The results presented here could be attractive for the ceramic forming industry and could be regarded as a reference for oxide systems in which, the GB areas are occupied with soft/elastic, highly energy-absorbing nanostructures.

ZrO2 impurity phase was examined by means of X-ray diffraction and scanning electron microscopy in reactive-sintered ZrB2–SiC–ZrC composites hot-pressed at 1600°C and 1800°C. An analytical electron microscopy study further revealed solid-solution of both Zr and O in the β-SiC phase: Zr:Si ratios were measured to be 1.83 ± 0.17 × 10−2 and 1.91 ± 0.16 × 10−2 respectively for each sample, while O:Si ratios were in the range of 2.3 ∼ 2.8 × 10−2. Common co-existence of ZrO2 grains and SiC grains containing Zr–O solutes indicates that this oxide plays a significant role in the sintering process, which substantially modifies the reactive phase relations. Observation of an intergranular Si–Zr–C–O glassy phase suggests the presence of a similar sintering liquid as a fast or even dominant diffusion path to promote the reactive sintering.

Divided orbital fibroblasts from patients with thyroid-associated ophthalmopathy (TAO) into CD90⁺ and CD90⁻ subsets respect to surface CD90 expression, then determined whether CD90⁺ and/or CD90⁻ fibroblasts were capable of differentiating into lipofibroblasts.Fibroblasts subset separation into CD90⁺ and CD90⁻ subsets was accomplished by three to four rounds of magnetic bead selection, then treated with 3-isobutyl-1-lmethylxanthine (IBMX), insulin and dexamethasone which was an known inducer of the lipofibroblastic phenotype, then the cells were observed every day to find Lipid droplets. Oil red O staining were conducted at 5 d, 10 d, 15 d, 20 d and 25 d after inducing. The percent of lipofibroblasts were calculated.The ratio in fibroblast derived from extraocular muscles of differentiating into lipofibroblast is less than from connective/adipose tissue (P0.05). The ratio of CD90⁺ fibroblast is less than CD90⁻ fibroblast (P0.05). CD90⁺ cells derived from extraocular miscles could not be induced to differentiate into lipofibroblast. The ratio in CD90⁻ fibroblast from connective/adipose tissue is highest (P0.05).Orbital fibroblast which has the function of differentiating into lipofibroblast is mainly CD90⁻ connective/adipose tissue.

Using elemental Zr, B, Mo and Si as raw materials, partially textured ZrB2–MoSi2 composites with in situ platelet ZrB2 grains were fabricated by reactive hot pressing. Synthesized by a combustion reaction, the in situ formed ZrB2 phase had unique characteristics to grow up to platelet grains, on the surroundings of Mo–Si–B ternary liquid phase at high temperature. Mechanical properties were dependent on grain size and aspect ratio of the ZrB2 platelets. The rotation and realignment of the platelet ZrB2 grains under hot pressing led to a partially textured microstructure, which showed anisotropic mechanical properties on different directions of the as-sintered samples. A roadmap of the reaction process, microstructure evolution and texture formation was given to describe the preparation of partially textured ZrB2–MoSi2 composites by reactive hot pressing. # 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Sirtuin 1 (Sirt1) is the class III histone/protein deacetylase that interferes with the NF-κB signaling pathway, thereby has anti-inflammatory function. This study was undertaken to investigate whether Sirt1 could protect osteoblasts against TNF-α-induced injury in vitro. Murine osteoblastic cell line, MC3T3-E1, was used. Overexpress of Sirt1 protein in MC3T3-E1 cells was made by transfection the cells with Sirt1-overexpressing adenovirus. The levels of mRNAs and proteins were determined with qRT-PCR and Western blotting, respectively. The activity of NF-κB was examined using NF-κB luciferase assay. The NO concentration was measured using the Griess method. Treatment of MC3T3-E1 cells with TNF-α (2.5–10 ng/mL) suppressed Sirt1 protein expression in a concentration-dependent manner. TNF-α (5 ng/mL) resulted in an increase in apoptosis and a reduction in ALP activity in the cells. Overexpression of Sirt1 in the cells significantly attenuated TNF-α-induced injury through suppressing apoptosis, increasing ALP activity, and increasing the expression of Runx2 and osteocalcin mRNAs. Furthermore, overexpression of Sirt1 in the cells significantly suppressed TNF-α-induced NF-κB activation, followed by reducing the expression of iNOS and NO formation. Sirt1 activator resveratrol (10 μmol/L) mimicked the protection of the cells by Sirt1 overexpression against TNF-α-induced injury, which was reversed by the Sirt1 inhibitor EX-527 (5 μmol/L). Overexpression of Sirt1 protects MC3T3-E1 osteoblasts aganst TNF-α-induced cell injury in vitro, at least in part, via suppressing NF-κB signaling. Sirt1 may be a novel therapeutic target for treating rheumatoid arthritis-related bone loss.