4-Hydroxy-2-Oxoglutaric Acid,A KeyMetabolite Involved in Trypsin-Regulation of Arginine Metabolism in Hylocereus undatus during Storage

Trypsin,a novel superoxide scavenger,significantly enhances the storage quality of Hylocereus undatus(H.undatus).To elucidate the preservation mechanism of trypsin on H.undatus,a widely targeted metabolomic analysis,and transcriptomics analysis were conducted.Firstly,a total of 453 metabolites were identified,with organic acids and their derivatives constituting the largest proportion(25%).Amino acids and their metabolites,prominent among organic acids,were further analyzed.Among them,73 metabolites were associated with amino acids,and 37 exhibited significant differences.The most enriched Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway was arginine biosynthesis(map00220),with polyamine metabolites showing the most pronounced differences,particularly spermine(FC=1.7594).Compared with the control group,4-hydroxy-2-oxoglutaric acid was significantly upregulated(FC=2.117)in the process of spermine biosynthesis.Furthermore,the results of Gene Ontology(GO)and KEGG enrichment analysis of the H.undatus transcriptome profile revealed that trypsin treatment led to 187 differentially expressed genes associated with arginine.Both GO and KEGG analyses exhibited significant enrichment in the spermine biosynthetic process(GO:0006597)(map:00220)within the arginine biosynthesis pathway.Moreover,most enzymes and metabolites within the spermine biosynthesis pathway in H.undatus were upregulated.The results of the PPI network highlighted that ADC,SPDS,and SAMDC,among others,were pivotal proteins involved in trypsin-regulated arginine metabolism and spermine synthesis.This study revealed that trypsin could significantly delay postharvest senescence of H.undatus at room temperature.This effect might be attributed to trypsin triggering the synthesis of 4-hydroxy-2-oxoglutaric acid in the fruit peel,thereby promoting the biosynthesis of spermine and other polyamines.

Efficient and photostable CsPbI_(2) Br solar cells realized by adding PMMA

Organic–inorganic hybrid perovskite materials demonstrate promising applications in high-efficiency perovskite solar cells (PSCs) with a certified power conversion efficiency(PCE) of 25.5%(https://www.nrel.gov/pv/cell-efficiency.html).

Successively Regioselective Electrosynthesis and Electron Transport Property of Stable Multiply Functionalized[60]Fullerene Derivatives

With the recent advance in chemical modification of fullerenes,electrosynthesis has demonstrated increasing importance in regioselective synthesis of novel fullerene derivatives.Herein,we report successively regioselective synthesis of stable tetra-and hexafunctionalized[60]fullerene derivatives.The cycloaddition reaction of the electrochemically generated dianions from[60]fulleroindolines with phthaloyl chloride regioselectively affords 1,2,4,17-functionalized[60]fullerene derivatives with two attached ketone groups and a unique addition pattern,where the heterocycle is rearranged to a[5,6]-junction and the carbocycle is fused to an adjacent[6,6]-junction.This addition pattern is in sharp contrast with that of the previously reported biscycloadducts,where both cycles are appended to[6,6]-junctions.The obtained tetrafunctionalized compounds can be successively manipulated to 1,2,3,4,9,10-functionalized[60]fullerene derivatives with an intriguing“S”-shaped configuration via a novel electrochemical protonation.Importantly,the stability of tetrafunctionalized[60]fullerene products allows them to be applied in planar perovskite solar cells as efficient electron transport layers.

Dithiol treatments enhancing the efficiency of hybrid solar cells based on PTB7 and CdSe nanorods

We report the fabrication of polymer/inorganic hybrid solar cells （HSCs） based on CdSe nanorods （NRs） and the semiconducting polymer PTB7. The power conversion efficiency of HSCs can be significantly enhanced by engineering the polymer/nanocrystal interface with ethanedithiol （EDT） and 1,4-benzenedithiol （1,4-BDT） treatments and reached 2.58% and 2.79%, respectively. These results were preferable to that of a pyridine-coated NR-based device （1.75%）. This improvement was attributed to the thiol groups of EDT and 1,4-BDT, which can tightly coordinate the Cd ions to form Cd-thialate on CdSe NR surfaces, thereby effectively passivating the NR surface and reducing the active layer defects. Therefore, the rate of exciton generation and dissociation was enhanced and led to the improvement of the device performance.