Since their discovery in 2011, 2D transition metal carbide/nitride (MXene) materials have received extensive interest due to their unique planar structure, chemical diversity, and superior physiochemical features. Very recently, MXenes have demonstrated outstanding photothermal conversion by virtue of excellent electromagnetic wave absorption capacity and a localized surface plasmon resonance effect. Photothermal conversion is an efficient way to utilize solar energy that allows the transformation of solar illumination into thermal energy, thus enabling MXenes to be applied in various fields, such as solar steam generation and biomedicals. However, the light-to-heat capability of MXenes has been paid much less attention until now. Recent progress in photothermal MXenes is reviewed to provide a comprehensive understanding of their photothermal conversion mechanism and applications. First, synthetic strategies of MXenes and their nanocomposites will be briefly summarized, and the discussion of the photothermal conversion mechanism and, most importantly, current advances in their photothermal applications will follow. It is highly anticipated that 2D MXenes, through elaborate material design and interdisciplinary approach, will become one of the mainstream photothermal materials and their application fields will also be expanded in the near future.

The North China Plain (NCP) is the most important agricultural production area in China. Crop production in the NCP is sensitive to changes in both climate and management practices. While previous studies showed a negative impact of climatic change on crop yield since 1980s, the confounding effects of climatic and agronomic factors have not been separately investigated. This paper used 25 years of crop data from three locations (Nanyang, Zhengzhou and Luancheng) across the NCP, together with daily weather data and crop modeling, to analyse the contribution of changes in climatic and agronomic factors to changes in grain yields of wheat and maize. The results showed that the changes in climate were not uniform across the NCP and during different crop growth stages. Warming mainly occurred during the vegetative (preflowering) growth stage of wheat and maize, while there was a cooling trend or no significant change in temperatures during the postflowering stage of wheat (spring) or maize (autumn). If varietal effects were excluded, warming during vegetative stages would lead to a reduction in the length of the growing period for both crops, generally leading to a negative impact on crop production. However, autonomous adoption of new crop varieties in the NCP was able to compensate the negative impact of climatic change. For both wheat and maize, the varietal changes helped stabilize the length of preflowering period against the shortening effect of warming and, together with the slightly reduced temperature in the postflowering period, extend the length of the grain-filling period. The combined effect led to increased wheat yield at Zhengzhou and Luancheng; increased maize yield at Nanyang and Luancheng; stabilized wheat yield at Nanyang, and a slight reduction in maize yield at Zhengzhou, compared with the yield change caused entirely by climatic change.

The fast development of nanoscience and nanotechnology has significantly advanced the fabrication of nanocatalysts and the in-depth study of the structural-activity characteristics of materials at the atomic level. Vacancies, as typical atomic defects or imperfections that widely exist in solid materials, are demonstrated to effectively modulate the physicochemical, electronic, and catalytic properties of nanomaterials, which is a key concept and hot research topic in nanochemistry and nanocatalysis. The recent experimental and theoretical progresses achieved in the preparation and application of vacancy-rich nanocatalysts for electrochemical water splitting are explored. Engineering of vacancies has shown to open up a new avenue beyond the traditional morphology, size, and composition modifications for the development of nonprecious electrocatalysts toward efficient energy conversion. First, an introduction followed by discussions of different types of vacancies, the approaches to create vacancies, and the advanced techniques widely used to characterize these vacancies are presented. Importantly, the correlations between the vacancies and activities of the vacancy-rich electrocatalysts via tuning the electronic states, active sites, and kinetic energy barriers are reviewed. Finally, perspectives on the existing challenges along with some opportunities for the further development of vacancy-rich noble metal-free electrocatalysts with high performance are discussed.

TiO 2 -based photocatalyst being inexpensive and abundant in conjunction with high photostability and environmental friendly characteristics makes it the most extensively studied photocatalytic material for hydrogen production and pollutant degradation. However, its existing issues such as wide bandgap, high overpotential and rapid recombination of photogenerated carriers limit its photocatalytic properties. The opportunities for structural development of TiO 2 nanomaterial towards highly efficient and pragmatic photocatalysis applications are evidently plentiful. Hence in this review, we will look into critical structural engineering strategies that endow favorable physicochemical properties such as improved light absorption, photostability, charge-carrier dynamics, increase surface area etc. that benefit photocatalysis functionalities. Amongst the various structural engineering constitutions, we will be covering the most prevalent and elegant core-shell and hierarchical structural designs that rationally combine the advantages of structural manipulation and multi-material composition engineering. This review aims to provide a comprehensive and contemporary overview as well as a guide of the development of new generation TiO 2 based photocatalysts via structural design for improved solar energy conversion technologies.

In article number 2000712, Laisheng Li, Jing Wang, and co‐workers discuss 2D MXenes, which demonstrate a superior photothermal conversion property by virtue of their electromagnetic wave absorption capacity and localized surface plasmon resonance effect. This efficient way to utilize solar energy that allows the transformation of solar illumination into thermal energy enables MXene‐based materials to be applied in diverse fields, such as solar steam generation and biomedicals.

Female fertility irreversibly declines with aging, and this is primarily associated with the decreased quality and quantity of oocytes. To evaluate whether a long‐term of melatonin treatment would improve the fertility of aged mice, different concentrations of melatonin (10−3, 10−5, 10−7 mol/L) were supplemented into drinking water. Melatonin treatments improved the litter sizes of mice at the age of 24 weeks. Mice treated with 10−5 mol/L melatonin had the largest litter size among other concentrations. At this optimal concentration, melatonin not only significantly increased the total number of oocytes but also their quality, having more oocytes with normal morphology that could generate more blastocyst after in vitro fertilization in melatonin (10−5 mol/L)‐treated group than that in the controls. When these blastocysts were transferred to recipients, the litter size was also significantly larger in melatonin treated mice than that in controls. The increases in TAOC and SOD level and decreases in MDA were detected in ovaries and uterus from melatonin‐treated mice compared to the controls. Melatonin reduced ROS level and maintained mitochondrial membrane potential in the oocytes cultured in vitro. Mechanistically studies revealed that the beneficial effects of melatonin on oocytes were mediated by MT1 receptor and AMPK pathway. Thereafter, MT1 knocking out (MT1‐KO) were generated and shown significantly reduced number of oocytes and litter size. The expression of SIRT1, C‐myc, and CHOP were downregulated in the ovary of MT1‐KO mice, but SIRT1 and p‐NF‐kB protein level were elevated in response to disturbed redox balance. The results have convincingly proven that melatonin administration delays ovary aging and improves fertility in mice via MT1/AMPK pathway.

No abstract

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most threatening pathogens due to its multi-drug resistance (MDR) and strong biofilm-forming capacity. Here, we described the screening of a novel chimeolysin (ClyF) that was active against planktonic and biofilm MRSA. Biochemical tests showed that ClyF was active against all S. aureus clinical isolates tested under planktonic and biofilm conditions. Structure analysis revealed that ClyF has an enhanced thermostability and pH tolerance than its parental lysin Pc by forming a hydrophobic cleft in the catalytic domain and an Ig-like structure in the cell-wall binding domain. A single intraperitoneally or topically administration of ClyF showed good MRSA removing efficacy in mouse models of bacteremia and burn wound infection, respectively. Our data collectively demonstrated that ClyF has good bactericidal activity against planktonic and biofilm MRSA both in vitro and in vivo, and therefore represents a useful antibacterial to combat MDR S. aureus.