A Review on Metal-and Metal Oxide-Based Nanozymes:Properties,Mechanisms,and Applications

Since the ferromagnetic(Fe_(3)O_(4))nanoparticles were firstly reported to exert enzyme-like activity in 2007,extensive research progress in nanozymes has been made with deep investigation of diverse nanozymes and rapid development of related nanotechnologies.As promising alterna-tives for natural enzymes,nanozymes have broadened the way toward clinical medicine,food safety,environmental monitoring,and chemical production.The past decade has witnessed the rapid development of metal-and metal oxide-based nanozymes owing to their remarkable physicochemical proper-ties in parallel with low cost,high stability,and easy storage.It is widely known that the deep study of catalytic activities and mechanism sheds sig-nificant influence on the applications of nanozymes.This review digs into the characteristics and intrinsic properties of metal-and metal oxide-based nanozymes,especially emphasizing their catalytic mechanism and recent applications in biological analysis,relieving inflammation,antibacterial,and cancer therapy.We also conclude the present challenges and provide insights into the future research of nanozymes constituted of metal and metal oxide nanomaterials.

Simple nucleophile/H_(2)O promoted defluorinative ring-opening of gem-difluorocyclopropenes

A novel defluorinative ring-opening of gem-difluorocyclopropenes is presented,providing a concise and efficient method for accessing 2-fluoropropenals and 2-fluorobuta-1,3-dienes in moderate to good yields with excellent regio-and stereoselectivities.The reaction is performed under mild conditions with no need of using an excess amount of nucleophilic reagents.Water plays a crucial role in this transformation.

Legume-specific SnRK1 promotes malate supply to bacteroids for symbiotic nitrogen fixation

Nodulation is an energy-expensive behavior driven by legumes by providing carbon sources to bacteroids and obtaining nitrogen sources in return.The energy sensor sucrose nonfermenting 1-related protein kinase 1(SnRK1)is the hub of energy regulation in eukaryotes.However,the molecular mechanism by which SnRK1 coordinates the allocation of energy and substances during symbiotic nitrogen fixation(SNF)remains unknown.In this study,we identified the novel legume-specific SnRK1α4,a member of the SnRK1 family that positively regulates SNF.Phenotypic analysis showed that nodule size and nitrogenase activity increased in SnRK1α4-overexpressing plants and decreased significantly in snrk1α4 mutants.We demonstrated that a key upstream kinase involved in nodulation,Does Not Make Infection 2(DMI2),can phosphorylate SnRK1α4 at Thr175 to cause its activation.Further evidence clarified that SnRK1α4 phosphorylates the malate dehydrogenases MDH1/2 to promote malate production in the cytoplasm,supplying carbon sources to bacteroids.Therefore,our findings reveal an essential role of the DMI2–SnRK1α4–MDH pathway in supplying carbon sources to bacteroids for SNF and provide a new module for constructing cereal crops with SNF.

Phase I study of camrelizumab in patients with advanced solid tumors

Dear Editor,Camrelizumab(SHR-1210)is a humanized monoclonal antibody(mAb)that binds to programmed cell death protein 1(PD-1).1 Since May 2019,camrelizumab has been successfully approved for the therapy of patients with various malignancies.2 However,only a few studies have focused on the pharmacokinetics(PK).

The Chromosome-Level Genome Sequence of the Autotetraploid Alfalfa and Resequencing of Core Germplasms Provide Genomic Resources for Alfalfa Research

Alfalfa(Medicago sativa)is one of the most important forage crops in the world;however,its molecular genetics and breeding research are hindered due to the lack of a high-quality reference genome.Here,we report a de novo assembled 816-Mb high-quality,chromosome-level haploid genome sequence for‘Zhongmu No.1’alfalfa,a heterozygous autotetraploid.The contig N50 is 3.92 Mb,and 49165 genes are annotated in the genome.The alfalfa genome is estimated to have diverged from M.truncatula approximately 8 million years ago.Genomic population analysis of 162 alfalfa accessions revealed high genetic diversity,weak population structure,and extensive gene flow from wild to cultivated alfalfa.Genome-wide association studies identified many candidate genes associated with important agronomic traits.Furthermore,we showed that MsFTa2,a Flowering Locus T homolog,whose expression is upregulated in salt-resistant germplasms,may be associated with fall dormancy and salt resistance.Taken together,these genomic resources will facilitate alfalfa genetic research and agronomic improvement.

Direct interaction between CD155 and CD96 promotes immunosuppression in lung adenocarcinoma

Despite the advance in targeted therapy,lung adenocarcinoma(LUAD)remains one of the leading causes of death in patients with cancer.CD155,a member of poliovirus receptor–related(PRR)family,has been identified as the ligand of the Ig-like receptors tactile(CD96)and DNAM-1(CD226)on T cells.The interaction of CD155 with CD96 transmits an inhibitory signal and suppresses immune response.The interaction of CD155 with CD226 enhances the immune response.1,2,3 CD155 expression has been shown to be elevated in many types of cancers4,5 and is involved with immune suppression in melanoma.6 However,how CD155/CD96 is involved in immune response in the tumor microenvironment of LUAD remains unknown.

The histone methyltransferase SUVR2 promotes DSB repair via chromatin remodeling and liquidliquid phase separation

Maintaining genomic integrity and stability is particularly important for stem cells,which are at the top of the cell lineage origin.Here,we discovered that the plant-specific histone methyltransferase SUVR2 maintains the genome integrity of the root tip stem cells through chromatin remodeling and liquid-liquid phase separation(LLPS)when facing DNA double-strand breaks(DSBs).The histone methyltransferase SUVR2(MtSUVR2)has histone methyltransferase activity and catalyzes the conversion of histone H3 lysine 9 monomethylation(H3K9me1)to H3K9me2/3 in vitro and in Medicago truncatula.Under DNA damage,the proportion of heterochromatin decreased and the level of DSB damage marker y-H2AX increased in suvr2 mutants,indicating that MtSUVR2 promotes the compaction of the chromatin structure through H3K9 methylation modification to protect DNA from damage.Interestingly,MtSUVR2 was induced by DSBs to phase separate and form droplets to localize at the damage sites,and this was confirmed by immunofluorescence and fluorescence recovery after photobleaching experiments.The IDR1 and lowcomplexity domain regions of MtSUVR2 determined its phase separation in the nucleus,whereas the IDR2 region determined the interaction with the homologous recombinase MtRAD51.Furthermore,we found that MtSUVR2 drove the phase separation of MtRAD51 to form"DNA repair bodies,"which could enhance the stability of MtRAD51 proteins to facilitate error-free homologous recombination repair of stem cells.Taken together,our study reveals that chromatin remodeling-associated proteins participate in DNA repair through LLPS.

Causes of Inflation in China:Inflation Expectations

This paper argues that the main causes of inflation in China since the early 21st century are changes in the public＇s inflation expectations. The conventional wisdom, the quantity theory of money, may not be adequate to capture the relationship between price changes and money supply growth, as the economic system evolves and people ＂s income and wealth grow. An examination of China＇s GDP deflator and broad money supply relative to nominal GDP shows that the relationship between the two series is relatively weak. A further examination of China＇s monthly CPI series over the period 2001-2010 reveals that the autoregressive models are a better fit than the moving average models, which suggests that the role of CPl expectations has been significant and important. Because of the importance of inflation expectations in CP1 movement, we believe the Central Bank＇s monetary policy that targets CPI inflation should emphasize the use of policy instruments that have direct and strong communication links with the public. Quantitative measures would have their own use, but their effectiveness would be unlikely to match that of interest rate measures, especially from a short-term perspective.