More intrinsic parameters should be used in assessing degeneration of articular cartilage with quantitative ultrasound

During the last decade, the quantitative ultrasound technique has been widely employed as a versatile modality to investigate a thin but crucial tissue layer – the articular cartilage. Previous studies provide information about the morphology and mechanical and acoustic properties of the tissue derived from ultrasound measurements and correlate them with cartilage degeneration. In a previous issue of Arthritis Research & Therapy, Kuroki and colleagues presented a study about the relationship between International Cartilage Repair Society grading and ultrasound echo magnitude, duration, and interval in human knee cartilage. We think indirect measurements of the intrinsic physical characteristics of cartilage, as reported in this study, should be interpreted more carefully as they can be affected by many experimental and physical factors. In this editorial, we offer our opinion that more intrinsic material parameters should be selected for the assessment of degeneration states of cartilage using quantitative ultrasound

Electronic, mechanical, and thermodynamic properties of americium dioxide

By performing density functional theory (DFT) +$U$ calculations, we systematically study the electronic, mechanical, tensile, and thermodynamic properties of AmO$_{2}$. The experimentally observed antiferromagnetic insulating feature [J. Chem. Phys. 63, 3174 (1975)] is successfully reproduced. It is found that the chemical bonding character in AmO$_{2}$ is similar to that in PuO$_{2}$, with smaller charge transfer and stronger covalent interactions between americium and oxygen atoms. The valence band maximum and conduction band minimum are contributed by 2$p-5f$ hybridized and 5$f$ electronic states respectively. The elastic constants and various moduli are calculated, which show that AmO$_{2}$ is less stable against shear forces than PuO$_{2}$. The stress-strain relationship of AmO$_{2}$ is examined along the three low-index directions by employing the first-principles computational tensile test method. It is found that similar to PuO$_{2}$, the [100] and [111] directions are the strongest and weakest tensile directions, respectively, but the theoretical tensile strengths of AmO$_{2}$ are smaller than those of PuO$_{2}$. The phonon dispersion curves of AmO$_{2}$ are calculated and the heat capacities as well as lattice expansion curve are subsequently determined. The lattice thermal conductance of AmO$_{2}$ is further evaluated and compared with attainable experiments. Our present work integrally reveals various physical properties of AmO$_{2}$ and can be referenced for technological applications of AmO$_{2}$ based materials.Comment: 23 pages, 8 figure

The effect of prestressing force on natural frequencies of concrete beams - A numerical validation of existing experiments by modelling shrinkage crack closure

This paper investigates the effect of prestressing force on the natural frequencies of reinforced concrete beams. From a pure theoretical point of view, such effects in different prestressing conditions appear to involve no ambiguity; however, in practice contradictory observations have been reported in existing research publications. Theoretical studies showed that natural frequencies would be decreasing or unchanged in different scenarios. On the other hand, some experiments that were conducted on prestressed concrete beams indicated an increasing trend of the natural frequencies with the prestressing force. This paper is aimed to provide a systematic explanation of the reasons causing the discrepancies and propose a coherent framework for the prediction of the natural frequencies under a prestressed condition. Numerical simulations using finite element model are carried out to simulate the influence of prestressing force on natural frequencies with the existence of the shrinkage cracks. The results demonstrate that such shrinkage-type cracks inside the concrete indeed tend to close when the prestressing force is applied, and this in turn increases the bending stiffness and consequently results in an increase of the natural frequencies of the beams.MOE (Min. of Education, S’pore)Accepted versio

Screening soybean for adaptation to relay intercropping systems: associations between reproductive organ abscission and yield

The flower and pod abscission is one of the characteristics of soybean that severely limits yield, especially when intercropped with maize. Therefore, suitable soybean cultivars for intercropping are urgently needed to improve farmland productivity. We conducted a two-year field experiment to evaluate the flower and pod abscission, dry matter production, and yield advantages of 15 soybean cultivars. The results of the principal component analysis (PCA) and cluster analysis (CA) showed that 15 soybean cultivars were classified into three groups, i.e., high-yielding group (HYG), mid-yielding cultivars (MYG), and low-yielding cultivars (LYG). In the HYG group, ND12 and GX3 had characteristics of more flowers and pods and less abscission of flowers and pods. Moreover, the net assimilation rate (NAR) and relative growth rate (RGR) of HYG were significantly higher than the other. The HYG obtained a considerably higher partition ratio of 53% from biomass to seed than the other. Therefore, selecting and breeding cultivars with the characteristics of more flowers and pods and less abscission of flowers and pods can help to increase soybean yield in intercropping.This research was funded by the Program on Industrial Technology System of National Soybean (CARS-04-PS18), and the National Key Research and Development Program of China (2021YFF1000500). Qing Du was a recipient of a joint PhD scholarship supported by the China Scholarship Council (CSC) (No. 202106910037)

Implementing universal nonadiabatic holonomic quantum gates with transmons

Geometric phases are well known to be noise-resilient in quantum evolutions/operations. Holonomic quantum gates provide us with a robust way towards universal quantum computation, as these quantum gates are actually induced by nonabelian geometric phases. Here we propose and elaborate how to efficiently implement universal nonadiabatic holonomic quantum gates on simpler superconducting circuits, with a single transmon serving as a qubit. In our proposal, an arbitrary single-qubit holonomic gate can be realized in a single-loop scenario, by varying the amplitudes and phase difference of two microwave fields resonantly coupled to a transmon, while nontrivial two-qubit holonomic gates may be generated with a transmission-line resonator being simultaneously coupled to the two target transmons in an effective resonant way. Moreover, our scenario may readily be scaled up to a two-dimensional lattice configuration, which is able to support large scalable quantum computation, paving the way for practically implementing universal nonadiabatic holonomic quantum computation with superconducting circuits.Comment: v3 Appendix added, v4 published version, v5 published version with correction

SYNTHESIS AND BIOLOGICAL EVALUATION OF NOVEL (2-OXO-3-(ARYLIMINO) INDOLIN-1-YL)-N-ARYL PROPANAMIDES AS ANTI-HUMAN IMMUNODEFICIENCY AGENTS

Objective: Acquired immunodeficiency syndrome (AIDS) was first identified in the Western world in 1981. Since then, AIDS has been increasingly wide spreading, its rapid worldwide dissemination brought about by modern mass tourism. Isatin (1 H-indole-2, 3-Dione), an endogenous compound identified in many organisms, shows a wide range of biological activities. In view of the above details, we wish to report the synthesis and evaluation of novel isatin analogs, as promising anti-human immunodeficiency (HIV) agents.Methods: A series of novel isatin analogs (3a-3p) were synthesized, and their chemical structures were confirmed by nuclear magnetic resonance:1H, 13C, ESI-MS spectral data, and CHNS.Results: The compounds were evaluated as inhibitors of HIV type-1 in MT-4 cell cultures. Of these sixteen compounds, only 5 compounds showed potent anti-HIV activity.Conclusion: Evaluation of compound properties in silico showed that they possess significant drug-like characteristics