Advanced Ceramics Manufacturing (United States)

Osteosarcoma (OS) constitutes a severe malignant disorder affecting bone tissue and poses a significant global public health risk. Here, we introduce an injectable, synergistic chemopiezodynamic therapy utilizing tin selenide (SnSe) two-dimensional nanosheets, which generate reactive oxygen species (ROS) to target OS effectively. We observed clear antitumor effects in OS following treatment with SnSe. These effects are primarily attributed to Sn/Se vacancy-driven free radical catalysis, known as chemodynamic therapy, and are further augmented by ultrasonic vibrations for ultrasound-triggered piezocatalysis (piezodynamic therapy). Additionally, SnSe induced apoptosis and autophagy in OS cells while demonstrating satisfactory histocompatibility in mouse models. Comprehensive assessments at both in vitro cellular level and in vivo xenograft models confirm that injectable SnSe nanosheets achieve cytotoxicity and tumor eradication via the synergistic effects of chemo-piezocatalysis. This research paves the way for the customized development of advanced nanocatalysts with integrated synergistic catalysis, offering promising avenues for enhanced therapeutic strategies in oncology.

Ultralong cylindrical and chain-beaded SiCnw with strong wave-absorbing capabilities were successfully synthesized by carbothermal reduction, employing coconut active charcoal as a carbon source, silicon powders as a silicon source, and graphite flake as a growth matrix. The sintering temperature and holding duration considerably influenced the composition, microstructure, morphology, dielectric properties, and absorption traits of SiCnw. Elevated sintering temperature facilitated the transformation from cylindrical to chain-beaded SiCnw. Extending the holding duration from 2 h to 6 h promoted SiCnw growth in both longitudinal and transverse directions. At 1200 °C for 2 h, the cylindrical SiCnw exhibited superior absorption properties, featuring an RL of −65.40 dB at 4.5 mm and 5.32 GHz, along with an EAB of 1.66 GHz spanning 4.64–6.30 GHz. When sintered at 1200 °C for 6 h, the cylindrical SiCnw demonstrated an RL of −57.70 dB at 2.00 mm and 14.86 GHz, along with an EAB of 5.50 GHz between 12.50 and 18.00 GHz. At 1400 °C for 6 h, the chain-beaded SiCnw exhibited an RL of −47.00 dB at 3.50 mm and 5.96 GHz and an EAB of 1.56 GHz across 5.30–6.86 GHz. These insights accentuate the considerable possibilities of SiCnw in electromagnetic wave absorption applications.

The present study reports trigonal phase molybdenum disulfide quantum dots (MoS2/QDs)-decorated (Bi1−xFex)VO4 composite heterostructures. Initially, (Bi1−xFex)VO4 heterostructure nanophotocatalysts were synthesized through the hydrothermal method decorated with 1T-MoS2via a sonication process. 1T-MoS2@(Bi1−xFex)VO4 heterostructures were characterized in detail for phase purity and crystallinity using XRD and Raman spectroscopy. The Raman mode evaluation indicated monoclinic, mixed monoclinic-tetragonal and tetragonal structure development with increasing Fe concentration. For physiochemical properties, SEM, EDX, XPS, PL, EPR, UV-visible and BET techniques were applied. The optical energy band gaps of 1T-MoS2@(Bi1−xFex)VO4 heterostructures were calculated using the Tauc plot method. It shows a blue shift initially within a monoclinic structure then a red shift with an increase of Fe concentration. 1T-MoS2@(Bi40Fe60)VO4 with 2 wt% of 1T-MoS2-QDs carrying a mixed phase exhibited higher photocatalytic activity. The enhanced photocatalytic activity is attributed to the higher electron transportation from (Bi1−xFex)VO4 surface onto 1T-MoS2 surface, consequently blocking the fast electron–hole recombination within (Bi1−xFex)VO4. 1T-MoS2 co-catalyst interaction with (Bi1−xFex)VO4 enhanced the light absorption in the visible region. The close contact of small 1T-MoS2-QDs with (Bi1−xFex)VO4 develops a high degree of crystallinity, with fewer defects showing mesoporous/nanoporous structures within the heterostructures which allows more active sites. Herein, the mechanism involved in the synthesis of heterostructures and optimum conditions for photocatalytic degradation of crystal violet dye are explored and discussed thoroughly.

To compare the inherent methanol steam reforming properties of intermetallic compounds and a corresponding intermetallic compound–oxide interface, we selected the Cu–In system as a model to correlate the stability limits, self-activation and redox activation properties with the catalytic performance. Three distinct intermetallic Cu–In compounds – Cu7In3, Cu2In and Cu11In9 – were studied both in an untreated and redox-activated state resulting from alternating oxidation–reduction cycles. The stability of all studied intermetallic compounds during methanol steam reforming (MSR) operation is essentially independent of the initial stoichiometry and all accordingly resist substantial structural changes. The inherent activity under batch MSR conditions is highest for Cu2In, corroborating the results of a Cu2In/In2O3 sample accessed through reactive metal–support interaction. Under flow MSR operation, Cu7In3 displays considerable deactivation, while Cu2In and Cu11In9 feature stable performance at simultaneously high CO2 selectivity. The missing significant self-activation is most evident in the operando thermogravimetric experiments, where no oxidation is detected for any of the intermetallic compounds. In situ X-ray diffraction allowed us to monitor the partial decomposition and redox activation of the Cu–In intermetallic compounds into Cu0.9In0.1/In2O3 (from Cu7In3), Cu7In3/In2O3 (from Cu2In) and Cu7In3/Cu0.9In0.1/In2O3 (from Cu11In9) interfaces with superior MSR performance compared to the untreated samples. Although the catalytic profiles appear surprisingly similar, the latter interface with the highest indium content exhibits the least deactivation, which we explain by formation of stabilizing In2O3 patches under MSR conditions.

Experimental Bayesian optimization for Li ion conductivity in NASICON-type LiZr2(PO4)3.

In this paper, we have introduced the auxetic effect in black phosphorus (BP) analog Sb and achieved auxetic modulations in monolayer As and Sb via first-principles calculations. Compared with monolayer As, the monolayer Sb is phonon unstable. By applying uniaxial strain along each direction, we discovered zigzag-vertical reversibility on out-of-plane auxeticity, and the negative Poisson's ratios for monolayer As and Sb were simulated to be -0.125/-0.172 and -0.036/-0.063, respectively, by applying the strain along zigzag/vertical directions. The negative Poisson's ratio could be significantly manipulated by applying a vertical electric field as it can be increased up to 70.3% for monolayer As and decreased up to 55.6% for monolayer Sb. Such an intrinsic negative Poisson's ratio and electric field modulation could endow these monolayers with potential applications in auxetic optoelectronic devices, electrodes and sensors, leading to novel multi-functionalities.

The Cover Feature shows a schematic representation of an anion exchange membrane fuel cell (AEMFC). A carbon-rich, silica-based ceramic composite decorated with intermetallic cobalt silicide nanospheres is presented as a new, non-precious-metal cathode electrocatalyst for AEMFCs. More information can be found in the Article by S. Abinaya et al. on page 3268 in Issue 13, 2019 (DOI: 10.1002/celc.201900475).

B4C-based ceramic composites containing 0–2 vol% highly aligned graphene nanoplatelets (GNPs) are fabricated. The electromagnetic interference (EMI) shielding properties of the obtained composites are investigated at X-band (8.2–12.4 GHz) frequency range from room-temperature up to 800 °C. All composites exhibit outstanding EMI shielding properties with satisfactory frequency- and thermal-stability. The shielding effectiveness (SE) of GNP/B4C composites increases monotonically with increasing GNP loading. Superior room-temperature SE close to 40 dB is achieved with only 2 vol% GNPs and high SE around 35 dB still persists at 800 °C. Considering their relatively low density, GNP/B4C composites possess a high specific shielding effectiveness (SSE) of 16 dB cm3 g−1 which is among the highest values in reported ceramic-based shielding composites. Especially, the GNP/B4C composite with 2 vol% GNPs exhibits the highest SSE/t (SSE divided by thickness) values at temperatures above 200 °C for all reported shielding composites, indicating that GNP/B4C composites belong to the most promising high-temperature shielding composites. The excellent shielding properties of GNP/B4C composites arise mainly from the high electrical conductivity, high dielectric loss and the multiple reflections by the highly aligned and large-sized GNP layers.