Electromagnetic shielding materials generated with the extensive application of electromagnetic wave have been utilized in military radar stealth, electromagnetic shielding of advanced electronic equipment, electromagnetic radiation protection, and other fields. With the quick development of Internet and electronic devices, a large number of electromagnetic waves flood into the living environment, affecting human life and health potentially. Meanwhile, further development and applications of terahertz (THz) electromagnetic detection technology challenge the research of electromagnetic interference shielding (EMIS). Therefore, EMIS materials have been developed toward the direction of high efficiency, wide bandwidth, and lightweight. However, traditional single metal-based and polymer-based EMIS materials cannot meet the demand. Current studies confirmed that graphene, especially graphene foam (GF)-based EMIS materials, has become one of the most potential EMIS materials in the field of electromagnetic wave loss and absorption due to its unique physical structure and excellent electrical and mechanical properties. GF, a three-dimensional graphene structure prepared from graphene and its derivatives not only fully utilizes the unique physical and chemical properties of graphene but also further reduces the density of EMIS materials and improves the EMIS performance. This work expounds the potential value of graphene in the field of EMIS based on the mechanism of EMIS and then summarizes the recent progress of GF-based materials for EMIS applications. More focus on the effects of different preparation methods toward the structure, mechanical properties, and EMIS performance of GF materials are introduced and discussed in detail.

Sulfur can form diverse S(IV) and S(VI) stereogenic centers, of which some have gained significant attention recently due to their increasing use as pharmacophores in drug discovery programs. The preparation of these sulfur stereogenic centers in their enantiopure form has been challenging, and progress made will be discussed in this Perspective. This Perspective summarizes different strategies, with selected works, for asymmetric synthesis of these moieties, including diastereoselective transformations using chiral auxiliaries, enantiospecific transformations of enantiopure sulfur compounds, and catalytic enantioselective synthesis. We will discuss the advantages and limitations of these strategies and will provide our views on how this field will develop.

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Hormone-sensitive lipase-knockout (HSL−/−) mice exhibit azoospermia for unclear reasons. To explore the basis of sterility, we performed the following three experiments. First, HSL protein distribution in the testis was determined. Next, transcriptome analyses were performed on the testes of three experimental groups. Finally, the fatty acid and cholesterol levels in the testes with three different genotypes studied were determined. We found that the HSL protein was present from spermatocyte cells to mature sperm acrosomes in wild-type (HSL+/+) testes. Spermiogenesis ceased at the elongation phase of HSL−/− testes. Transcriptome analysis indicated that genes involved in lipid metabolism, cell membrane, reproduction and inflammation-related processes were disordered in HSL−/− testes. The cholesterol content was significantly higher in HSL−/− than that in HSL+/+ testis. Therefore, gene expression and cholesterol ester content differed in HSL−/− testes compared to other testes, which may explain the sterility of male HSL−/− mice.