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Effects of ancillary ligands in acceptorless benzyl alcohol dehydrogenation mediated by phosphine-free cobalt complexes

《化学科学与工程前沿(英文)》 2023年 第17卷 第3期   页码 314-325 doi: 10.1007/s11705-022-2219-2

摘要: Acceptorless alcohol dehydrogenation stands out as one of the most promising strategies in hydrogen storage technologies. Among various catalytic systems for this reaction, cost-effective molecular catalysts using phosphine-free ligands have gained considerable attention. However, the central challenge for using non-precious metals is to overcome the propensity of reacting by one-electron pathway. Herein, we synthesized a phosphine-free η5-C5Me5-Co complex by using the metal–ligand cooperative strategy and compared its activity with analogous catalysts toward acceptorless alcohol dehydrogenation. The catalyst showed excellent performance with a turnover number of 130.4 and a selectivity close to 100%. The improved performance among the class of η5-C5Me5-Co complexes could be attributed to the more accessible Co center and its cooperation with the redox-active ligand. To further study the systematic structure-activity relationship, we investigated the electronic structures of η5-C5Me5-Co complexes by a set of characterizations. The results showed that the redox-active ligand has a significant influence on the η5-C5Me5-Co moiety. In the meantime, the proximal O/OH group is beneficial for shuttling protons. For the catalytic cycle, two dehydrogenation scenarios were interrogated through density functional theory, and the result suggested that the outer-sphere pathway was preferred. The formation of a dihydrogen complex was the rate-determining step with a ΔG value of 16.9 kcal∙mol‒1. The electron population demonstrated that the η5-C5Me5 ligand played a key role in stabilizing transition states during dehydrogenation steps. This work identified the roles of vital ligand components to boost catalytic performance and offered rationales for designing metal–ligand cooperative nonprecious metal complexes.

关键词: acceptorless alcohol dehydrogenation     η5-C5Me5-Co     metal–ligand cooperation     theoretical calculation    

RGS16 regulated by let-7c-5p promotes glioma progression by activating PI3K-AKT pathway

《医学前沿(英文)》 2023年 第17卷 第1期   页码 143-155 doi: 10.1007/s11684-022-0929-y

摘要: Gliomas are the most common central nervous system tumours; they are highly aggressive and have a poor prognosis. RGS16 belongs to the regulator of G-protein signalling (RGS) protein family, which plays an important role in promoting various cancers, such as breast cancer, pancreatic cancer, and colorectal cancer. Moreover, previous studies confirmed that let-7c-5p, a well-known microRNA, can act as a tumour suppressor to regulate the progression of various tumours by inhibiting the expression of its target genes. However, whether RGS16 can promote the progression of glioma and whether it is regulated by miR let-7c-5p are still unknown. Here, we confirmed that RGS16 is upregulated in glioma tissues and that high expression of RGS16 is associated with poor survival. Ectopic deletion of RGS16 significantly suppressed glioma cell proliferation and migration both in vitro and in vivo. Moreover, RGS16 was validated as a direct target gene of miR let-7c-5p. The overexpression of miR let-7c-5p obviously downregulated the expression of RGS16, and knocking down miR let-7c-5p had the opposite effect. Thus, we suggest that the suppression of RGS16 by miR let-7c-5p can promote glioma progression and may serve as a potential prognostic biomarker and therapeutic target in glioma.

关键词: RGS16     let-7c-5p     glioma     proliferation     migration    

The modification of titanium in mesoporous silica for Co-based Fischer–Tropsch catalysts

《化学科学与工程前沿(英文)》 2022年 第16卷 第8期   页码 1224-1236 doi: 10.1007/s11705-022-2139-1

摘要: Ordered SBA-15 mesoporous silica with incorporated titanium was successfully synthesized via a one-pot hydrothermal crystallization method. The characterization including powder X-ray diffraction, Brunauer–Emmett–Teller, transmission electron microscope, temperature-programmed reduction, temperature-programmed desorption, Fourier transform infrared and ultraviolet-visible-near infrared spectrometer was performed to explore the physical and chemical structures of both the supports and the catalysts. The results showed that titanium was successfully incorporated into the mesoporous silica framework with a limited amount of titanium (Si/Ti > 20), and the mesoporous structure was retained. However, the increased titanium content inevitably resulted in the formation of anatase TiO 2 particles on the support surface. The increased incorporated titanium strengthened the interactions between cobalt species and supports, which was favorable for the cobalt species dispersion, despite the limited cobalt oxide reducibility. The enhanced metal-support interactions were beneficial for the CO/H2 ratio at the active cobalt sites, which facilitated the formation of more C5+ hydrocarbons. This study provides a promising method for support modification with incorporated-heteroatoms for the rational development of Fischer–Tropsch catalysts.

关键词: Fischer–Tropsch synthesis     titanium incorporation     mesoporous silica     metal-support interactions     C5+ selectivity    

Novel mutation c.1210-3C>G in with a poly-T tract of 5T affects mRNA splicing in a Chinese patient

《医学前沿(英文)》 2022年 第16卷 第1期   页码 150-155 doi: 10.1007/s11684-021-0846-5

摘要: Cystic fibrosis (CF) is a rare autosomal recessive disease with only one pathogenic gene cystic fibrosis transmembrane conductance regulator (CFTR). To identify the potential pathogenic mutations in a Chinese patient with CF, we conducted Sanger sequencing on the genomic DNA of the patient and his parents and detected all 27 coding exons of CFTR and their flanking intronic regions. The patient is a compound heterozygote of c.2909G>A, p.Gly970Asp in exon 18 and c.1210-3C>G in cis with a poly-T of 5T (T5) sequence, 3 bp upstream in intron 9. The splicing effect of c.1210-3C>G was verified via minigene assay in vitro, indicating that wild-type plasmid containing c.1210-3C together with T7 sequence produced a normal transcript and partial exon 10-skipping-transcript, whereas mutant plasmid containing c.1210-3G in cis with T5 sequence caused almost all mRNA to skip exon 10. Overall, c.1210-3C>G, the newly identified pathogenic mutation in our patient, in combination with T5 sequence in cis, affects the CFTR gene splicing and produces nearly no normal transcript in vitro. Moreover, this patient carries a p.Gly970Asp mutation, thus confirming the high-frequency of this mutation in Chinese patients with CF.

关键词: cystic fibrosis     CFTR     splicing mutation     minigene    

On the monolayer dispersion behavior of Co3O4 on HZSM-5 support: designing applicable

《化学科学与工程前沿(英文)》 2023年 第17卷 第11期   页码 1741-1754 doi: 10.1007/s11705-023-2332-x

摘要: Based on monolayer dispersion theory, Co3O4/ZSM-5 catalysts with different loadings have been prepared for selective catalytic reduction of nitrogen oxides by ammonia. Co3O4 can spontaneously disperse on HZSM-5 support with a monolayer dispersion threshold of 0.061 mmol 100 m–2, equaling to a weight percentage around 4.5%. It has been revealed that the quantities of surface active oxygen (O2) and acid sites are crucial for the reaction, which can adsorb and activate NOx and NH3 reactants effectively. Below the monolayer dispersion threshold, Co3O4 is finely dispersed as sub-monolayers or monolayers and in an amorphous state, which is favorable to generate the two kinds of active sites, hence promoting the performance of ammonia selective catalytic reduction of nitrogen oxide. However, the formation of crystalline Co3O4 above the capacity is harmful to the reaction performance. 4% Co3O4/ZSM-5, the catalyst close to the monolayer dispersion capacity, possesses the most abundant active O2 species and acidic sites, thereby demonstrating the best reaction performance in all the samples. It is proposed the optimal Co3O4/ZSM-5 catalyst can be prepared by loading the capacity amount of Co3O4 onto HZSM-5 support.

关键词: Co3O4/ZSM-5     NOx-SCR by NH3     monolayer dispersion threshold effect     surface acid sites     surface active O2 anions    

5G成效未达预期

Mitch Leslie

《工程(英文)》 2023年 第29卷 第10期   页码 5-7 doi: 10.1016/j.eng.2023.08.003

Facile controlled synthesis of hierarchically structured mesoporous Li4Ti5O12/C/rGO composites as high-performance

Cehuang FU, Shuiyun SHEN, Ruofei WU, Xiaohui YAN, Guofeng XIA, Junliang ZHANG

《能源前沿(英文)》 2022年 第16卷 第4期   页码 607-612 doi: 10.1007/s11708-021-0798-0

摘要: In this paper, a facile strategy is proposed to controllably synthesize mesoporous Li4Ti5O12/C nanocomposite embedded in graphene matrix as lithium-ion battery anode via the co-assembly of Li4Ti5O12 (LTO) precursor, GO, and phenolic resin. The obtained composites, which consists of a LTO core, a phenolic-resin-based carbon shell, and a porous frame constructed by rGO, can be denoted as LTO/C/rGO and presents a hierarchical structure. Owing to the advantages of the hierarchical structure, including a high surface area and a high electric conductivity, the mesoporous LTO/C/rGO composite exhibits a greatly improved rate capability as the anode material in contrast to the conventional LTO electrode.

关键词: Li4Ti5O12     phenolic-resin-based carbon     mesoporous composite     graphene    

基于 5G技术的教育信息化应用研究

卢向群,孙禹

《中国工程科学》 2019年 第21卷 第6期   页码 120-128 doi: 10.15302/J-SSCAE-2019.06.020

摘要:

教育信息化日益普及,智慧学习空间不断出现,学生对学习内容的个性化、便捷化、多样化需求也日益凸显,而第五代移动通信( 5G)技术以其大带宽、本文重点探索 5G技术的教育信息化应用,在梳理教育信息化主要特征的基础上,分析了我国教育网络面临的技术挑战,从教学、教研、教育管理三方面着手,论证提出相应的 5G应用场景,形成 5G教育信息化总体视图。面向 2035年, 5G的技术普及与应用拓展,将不断丰富教育场景的内涵,推动教育场景的变革,成为我国教育信息化创新的原生动力。

关键词: 教育     信息技术     教育信息化     5G 技术     应用场景    

5G应用下的MIMO阵列天线去耦方法综述 Review Articles

Xiao-xi ZHANG, Ai-di REN, Ying LIU

《信息与电子工程前沿(英文)》 2020年 第21卷 第1期   页码 62-71 doi: 10.1631/FITEE.1900466

摘要: 提出一种面向微纳卫星的自主汽化管理液氨推进系统。相比常规冷气或液化气推进系统,提出多路平行筛孔式汽化装置和对应汽化控制方法。所提方案有效解决了液氨高汽化潜热和不易完全汽化的问题,从而发挥液氨推进剂高贮存密度和高比冲性能优势。此外,重点分析自主汽化管理液氨推进系统的工作流程及其涉及的物理化学过程和数学模型。综合考虑推力表现和能源效率,提出最优系统推力控制策略。地面测试表明,自主汽化管理液氨推进系统总重1.8 kg(包含0.34 kg液氨推进剂),比冲达到100 s,系统功耗在10 W以下。自主汽化管理液氨推进系统具有高比冲、低功耗、可实现性强、推力输出均一稳定等特点,适合微纳卫星在轨应用。

关键词: MIMO阵列;5G手机;去耦方法    

lncR-GAS5 upregulates the splicing factor to impair endothelial autophagy, leading to atherogenesis

《医学前沿(英文)》 2023年 第17卷 第2期   页码 317-329 doi: 10.1007/s11684-022-0931-4

摘要: Long noncoding RNAs (lncRNAs) play a critical role in the regulation of atherosclerosis. Here, we investigated the role of the lncRNA growth arrest-specific 5 (lncR-GAS5) in atherogenesis. We found that the enforced expression of lncR-GAS5 contributed to the development of atherosclerosis, which presented as increased plaque size and reduced collagen content. Moreover, impaired autophagy was observed, as shown by a decreased LC3II/LC3I protein ratio and an elevated P62 level in lncR-GAS5-overexpressing human aortic endothelial cells. By contrast, lncR-GAS5 knockdown promoted autophagy. Moreover, serine/arginine-rich splicing factor 10 (SRSF10) knockdown increased the LC3II/LC3I ratio and decreased the P62 level, thus enhancing the formation of autophagic vacuoles, autolysosomes, and autophagosomes. Mechanistically, lncR-GAS5 regulated the downstream splicing factor SRSF10 to impair autophagy in the endothelium, which was reversed by the knockdown of SRSF10. Further results revealed that overexpression of the lncR-GAS5-targeted gene miR-193-5p promoted autophagy and autophagic vacuole accumulation by repressing its direct target gene, SRSF10. Notably, miR-193-5p overexpression decreased plaque size and increased collagen content. Altogether, these findings demonstrate that lncR-GAS5 partially contributes to atherogenesis and plaque instability by impairing endothelial autophagy. In conclusion, lncR-GAS5 overexpression arrested endothelial autophagy through the miR-193-5p/SRSF10 signaling pathway. Thus, miR-193-5p/SRSF10 may serve as a novel treatment target for atherosclerosis.

关键词: lncR-GAS5     miR-193-5p     splicing factor SRSF10     autophagy     atherogenesis    

2020普遍通信与5G技术国际会议(UC5G 2020)

会议日期: 2020年03月26日

会议地点: 上海

主办单位: APISE

Boehmite-supported CuO as a catalyst for catalytic transfer hydrogenation of 5-hydroxymethylfurfural

《化学科学与工程前沿(英文)》 2023年 第17卷 第4期   页码 415-424 doi: 10.1007/s11705-022-2225-4

摘要: 2,5-bis(hydroxymethyl)furan (BHMF) is an important monomer of polyester. Its oxygen-containing rigid ring structure and symmetrical diol functional group establish it as an alternative to petroleum-based monomer with unique advantages for the prodution of the degradable bio-based polyester materials. Herein, we prepared a boehmite-supported copper-oxide catalyst for the selective hydrogenation of 5-hydroxymethylfurfural into BHMF via catalytic transfer hydrogenation (CTH). Further, ethanol successfully replaced conventional high-pressure hydrogen as the hydrogen donor, with up to 96.9% BHMF selectivity achieved under suitable conditions. Through characterization and factor investigations, it was noted that CuO is crucial for high BHMF selectivity. Furthermore, kinetic studies revealed a higher by-product activation energy compared to that of BHMF, which explained the influence of reaction temperature on product distribution. To establish the catalyst structure-activity correlation, a possible mechanism was proposed. The copper-oxide catalyst deactivated following CTH because ethanol reduced the CuO, which consequently decreased the active sites. Finally, calcination of the catalyst in air recovered its activity. These results will have a positive impact on hydrogenation processes in the biomass industry.

关键词: biomass     5-hydroxymethylfurfural     2     5-bis(hydroxymethyl)furan     transfer hydrogenation     catalysis    

一场潜在的5G干扰风暴

Chris Palmer

《工程(英文)》 2019年 第5卷 第5期   页码 815-816 doi: 10.1016/j.eng.2019.08.007

2020年5G移动通信与信息科学国际学术会议(MCIS-5G2020)

会议日期: 2020年06月26日

会议地点: 广东广州

5G综述及中国的进展 None

Shan-zhi CHEN, Shao-li KANG

《信息与电子工程前沿(英文)》 2018年 第19卷 第3期   页码 309-321 doi: 10.1631/FITEE.1800070

摘要: 5G技术、标准和产业化从20012年开始高速发展,是全球经济新的驱动力。本文全面介绍了5G,包括愿景、要求、演进、关键技术、标准化、频谱分配、技术试验、产业化进展和5G主要贡献者。同时指出,中国企业作为5G主要技术和标准的贡献者,正处于“5G引领”过程中。最后介绍了5G最新进展和作者关于5G的再思考。

关键词: 5G;IMT-2020;关键技术;标准;现场试验    

标题 作者 时间 类型 操作

Effects of ancillary ligands in acceptorless benzyl alcohol dehydrogenation mediated by phosphine-free cobalt complexes

期刊论文

RGS16 regulated by let-7c-5p promotes glioma progression by activating PI3K-AKT pathway

期刊论文

The modification of titanium in mesoporous silica for Co-based Fischer–Tropsch catalysts

期刊论文

Novel mutation c.1210-3C>G in with a poly-T tract of 5T affects mRNA splicing in a Chinese patient

期刊论文

On the monolayer dispersion behavior of Co3O4 on HZSM-5 support: designing applicable

期刊论文

5G成效未达预期

Mitch Leslie

期刊论文

Facile controlled synthesis of hierarchically structured mesoporous Li4Ti5O12/C/rGO composites as high-performance

Cehuang FU, Shuiyun SHEN, Ruofei WU, Xiaohui YAN, Guofeng XIA, Junliang ZHANG

期刊论文

基于 5G技术的教育信息化应用研究

卢向群,孙禹

期刊论文

5G应用下的MIMO阵列天线去耦方法综述

Xiao-xi ZHANG, Ai-di REN, Ying LIU

期刊论文

lncR-GAS5 upregulates the splicing factor to impair endothelial autophagy, leading to atherogenesis

期刊论文

2020普遍通信与5G技术国际会议(UC5G 2020)

2020年03月26日

会议信息

Boehmite-supported CuO as a catalyst for catalytic transfer hydrogenation of 5-hydroxymethylfurfural

期刊论文

一场潜在的5G干扰风暴

Chris Palmer

期刊论文

2020年5G移动通信与信息科学国际学术会议(MCIS-5G2020)

2020年06月26日

会议信息

5G综述及中国的进展

Shan-zhi CHEN, Shao-li KANG

期刊论文