PDZK1 protects against mechanical overload-induced chondrocyte senescence and osteoarthritis by targeting mitochondrial function

Mechanical overloading and aging are two essential factors for osteoarthritis(OA)development.Mitochondria have been identified as a mechano-transducer situated between extracellular mechanical signals and chondrocyte biology,but their roles and the associated mechanisms in mechanical stress-associated chondrocyte senescence and OA have not been elucidated.

Experimental research on stabilities, thermophysical properties and heat transfer enhancement of nanofluids in heat exchanger systems

Stable TiO_2–water nanofluids are prepared by a two-step method, stabilities of nanofluids are investigated by precipitation method and transmittance method respectively, and thermal conductivities and viscosities are also measured. An experimental system for studying the heat transfer enhancement of nanofluids is established,and heat transfer and flow characteristics of TiO_2–water nanofluids in heat exchanger systems with a triangular tube and circular tube are experimentally studied. The effects of nanoparticle mass fractions(ω = 0.1 wt%–0.5 wt%) and Reynolds numbers(Re = 800–10000) on the heat transfer and flow performances of nanofluids are analyzed. Fitting formulas for Nusselt number and resistance coefficient of nanofluids in a triangular tube are put forward based on the experimental data. The comprehensive performances of nanofluids in a triangular tube are investigated. It is found that nanofluids in a triangular tube can significantly improve the heat transfer performance at the cost of a small increase in resistance coefficient compared with that in a circular tube, especially the resistance coefficients are almost the same between different nanoparticle mass fractions at turbulent flow. It is also found that the comprehensive evaluation index η decreases with Reynolds number at laminar flow but a critical maximum value appears at turbulent flow.

Design, Synthesis, and Biological Activity of Novel Aromatic Amide Derivatives Containing Sulfide and Sulfone Substructures

In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inhibitor(SDHI)fungicide developed by Bayer AG in Germany,has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action.In this paper,two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures.The structures were identified and characterized by 1H nuclear magnetic resonance(NMR),13C NMR,and high-resolution mass spectrometer(HRMS).The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 lgmL-1 in comparison with fluopyram,while the nematode mortality rate dropped sharply at 100μg·mL-1,except for compounds I-11 and II-6.In terms of fungicidal activity,compound I-9 was discovered to have an excellent inhibitory rate,and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.

High-tenacity in-situ Ti/Zr-based bulk metallic glasses composites fabricated by industrial high-pressure die casting

The glass-forming ability and mechanical properties of metallic glasses and their composites are well known to be sensitive to the preparation conditions and are highly deteriorated by industrial preparing conditions such as low-purity raw materials and low vacuum.Here,we showed that a series of in-situ bulk metallic glass composites(BMGCs)which exhibit excellent ductility and segmental work hardening were successfully developed utilizing a high vacuum high-pressure die casting(HV-HPDC)technology along with industrial-grade raw materials.The tensile properties of these BMGCs are systematically investigated and correlated with the alloy microstructure.As compared with the copper mold suction casting method,the volume fraction difference of the dendrite phase for the BMGCs with the same composition is not significant when fabricated by the HV-HPDC,whereas the size of theβ-phase is generally larger.Insitu BMGCs with the composition of Ti_(48)Zr_(20)(V_(12/17)Cu_(5/17))19 Be 13 obtained by the HV-HPDC process show ductility up to 11.3%under tension at room temperature and exhibit a certain amount of work hardening.Two conditions need to be met to enable the BMGCs,which are prepared by vacuum die-casting to retain favorable ductility:(1)The volume fraction ofβphase stays below 62%±2%;(2)The equiaxed crystals with a more uniform size in the range of 5-10μm.Meanwhile,the results of the present study provided guidance for developing BMGCs with good ductile properties under industrial conditions.

Potential effects of elevated carbon dioxide on leaf-feeding forest insects

The elevated concentration of atmospheric CO_(2)may result in a decline of leaf nutritional quality(especially N)and an increase in some kinds of defensive secondary components(such as phenolics).The changes in the phytochemistry of trees,combined with the effect of elevated CO_(2)per se,have a potential negative influence on insect herbivores.Here,we review the effect of elevated CO_(2)on the performance of leaf-feeding forest insects at individual-level and commun-ity-level.The elevated CO_(2)per se have little influence on the metabolism of insects.Over half of the tree-insect experimental systems show that the performance of individual insect become poorer under high-CO_(2)grown trees;but the others show that the insects have just little or no response to the treatments.The direction and magnitude of the changes in the performance of insects could be mediated by various factors.The effects of treatment are strongly species-dependent.The mag-nitude of changes in the phytochemistry,the sensitivity and adaptive capacity of insects to the poorer leaf quality,the differences in plant growth conditions and experimental methods,and the mediated effects of other environmental factors(such as soil nutrient availability,light,temperature,O_(3))were all closely related to the final performance of insects.However,the larvae’s consumption usually increased under enriched CO_(2)treatment,which was widely thought to be a compens-atory response to poorer plant quality.The experiments on forest community-level found identically a reduction in herbivory,which was contrary to the results from small-scale experiments.The changes in insect popu-lation and the actual response of consumption by leaf-feeding forest insects under CO_(2)enrichment remain unclear,and more field-based experiments need to be conducted.