Synthesis of diamond from a chlorinated organic substance under hydrothermal conditions

Hydrothermal growth of diamond particles and films was achieved during interaction of a liquid organic precursor (C₂H₃Cl₃) and 10 M NaOH in the presence of diamond or cubic BN seeds at the temperature 300 °C and 1 GPa pressure. Synthesized diamond was thoroughly characterized by TG-DTA, SEM, EDX, TEM, Raman spectroscopy and had (220) preferable orientation according to XRD pattern in the case of the film.     

Consolidation and high-temperature strength of monolithic lanthanum hexaboride

In this study we explored the densification, microstructure evolution, and high-temperature properties of bulk lanthanum hexaboride. LaB₆ bulks were consolidated using spark-plasma sintering only in the temperature range between 1400°C and 1700°C. We adopted flash spark plasma sintering (SPS) of LaB₆ using a direct current heating without a graphite die. We observed a peculiar grain-size gradient when coarse grains exceeding 300 μm were observed on the top side of the specimen, while the bottom side had a grain size of 15–20 μm. Such large grain was not observed using SPS at 2000°C, suggesting that these might originate from a local overheating. Based on the three-point flexural tests, it was observed that the toughness and strength of the LaB₆ were acceptable at room-temperature (3.1 ± 0.2 MPa m^1/2, 300 ± 20 MPa). However, at 1600°C, these parameters would decrease to 1.3 ± 0.1 MPa m^1/2 and 120 ± 40 MPa, respectively.     

Protective Effect of Water-Soluble C60 Fullerene Nanoparticles on the Ischemia-Reperfusion Injury of the Muscle Soleus in Rats

The biomechanical parameters of muscle soleus contraction in rats and their blood biochemical indicators after the intramuscular administration of water-soluble C₆₀ fullerene at doses of 0.5, 1, and 2 mg/kg 1 h before the onset of muscle ischemia were investigated. In particular, changes in the contraction force of the ischemic muscle soleus, the integrated power of the muscle, the time to achieve the maximum force response, the dynamics of fatigue processes, and the parameters of the transition from dentate to smooth tetanus, levels of creatinine, creatine kinase, lactate and lactate dehydrogenase, and parameters of prooxidant–antioxidant balance (thiobarbituric acid reactive substances, hydrogen peroxide, and reduced glutathione and catalase) were analyzed. The positive therapeutic changes in the studied biomechanical and biochemical markers were revealed, which indicate the possibility of using water-soluble C₆₀ fullerenes as effective prophylactic nanoagents to reduce the severity of pathological conditions of the muscular system caused by ischemic damage to skeletal muscles.     

Phase equilibria on the ternary Mg–Mn–Ce system at the Mg-rich corner

Three isopleths at the Mg-rich corner of Mg–Mn–Ce ternary system were investigated via thermal analysis, SEM/EPMA and XRD. A ternary eutectic reaction was observed at 1 wt.% Mn and 23 wt.% Ce and 592 °C. A solid-solution type ternary intermetallic compound, (Mg,Mn)₁₂Ce, was observed with 0.5 at% solid solubility of Mn in the tetragonal Mg₁₂Ce. With the aid of thermodynamic modeling and experiments, a revised phase diagram for the binary Mg–Ce system and the isopleths of 0.6, 1.8 and 2.5 wt.% Mn were proposed up to 25 wt.% Ce.     

Kinetics and thermodynamics of hydrogenation-dehydrogenation for Mg-25%TM (TM = Ti,Nb or V) composites synthesized by reactive ball milling in hydrogen

0.75Mg?0.25TM?H (TM = Ti, Nb or V) samples were mechano-chemically synthesized by reactive ball milling. The detailed reaction mechanism during hydrogen release and uptake was investigated by in-situ synchrotron radiation powder X-ray diffraction (SR-PXD) experiments. The thermodynamic and kinetic properties have been studied by Sievert's method. On the base of calculated values of the Gibbs free energy for reaction of hydrogen absorption (ΔG < 0) it reveals that hydrogenation reaction could thermodynamically proceed at room temperature, which is experimentally confirmed for all of the studied composites. It is clearly shown that β-MgH₂ forms at RT under conditions of experiment. Comparative analysis of the MgTi, MgV and MgNb systems makes it possible to establish that the most effective additive facilitating hydrogen uptake, particularly at RT, is vanadium. It provides the degree of conversion into hydride phase α = 0.86 for the first minute of hydrogenation. In contrast, additives of Nb and Ti provide only α = 0.62 and 0.36, respectively, following the 30 min of exposure. However, this study reveals that for the dehydrogenation process, titanium is the best among the examined additives, which is evidenced by lowest value of activation energy E_a = 53.6 kJ/mol of the hydrogen desorption.     

Fine equiaxed β grains and superior tensile property in Ti-6Al-4V alloy deposited by coaxial electron beam wire feeding additive manufacturing

Coarse columnar β grains result in anisotropic mechanical properties in Ti alloys deposited by additive manufacturing. This study reports that Ti-6Al-4V alloy fabricated by coaxial electron beam wire feeding additive manufacturing presents a weak anisotropy, high strength and ductility. The superior tensile property arises from a microstructure with fine equiaxed β grains (EGβ), discontinuous grain boundary α phase and short intragranular α lamellae. A large region of fine EGβ arises from a special combination of the temperature gradient and solidification rate, and attractive α morphology is caused by solid phase transformations during interpass thermal cycling and post heat treatments.     

Tilting the Balance: Therapeutic Prospects of CD83 as a Checkpoint Molecule Controlling Resolution of Inflammation

Chronic inflammatory diseases and transplant rejection represent major challenges for modern health care. Thus, identification of immune checkpoints that contribute to resolution of inflammation is key to developing novel therapeutic agents for those conditions. In recent years, the CD83 (cluster of differentiation 83) protein has emerged as an interesting potential candidate for such a “pro-resolution” therapy. This molecule occurs in a membrane-bound and a soluble isoform (mCD83 and sCD83, respectively), both of which are involved in resolution of inflammation. Originally described as a maturation marker on dendritic cells (DCs), mCD83 is also expressed by activated B and T cells as well as regulatory T cells (Tregs) and controls turnover of MHC II molecules in the thymus, and thereby positive selection of CD4⁺ T cells. Additionally, it serves to confine overshooting (auto-)immune responses. Consequently, animals with a conditional deletion of CD83 in DCs or regulatory T cells suffer from impaired resolution of inflammation. Pro-resolving effects of sCD83 became evident in pre-clinical autoimmune and transplantation models, where application of sCD83 reduced disease symptoms and enhanced allograft survival, respectively. Here, we summarize recent advances regarding CD83-mediated resolution of inflammatory responses, its binding partners as well as induced signaling pathways, and emphasize its therapeutic potential for future clinical trials.