Environmental Chemistry Letters
·
2019
·Vol. 18
·期 2
·475-481
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IF 4.617
Nivesse A-L.,Thibault de Chanvalon A.,Baglan N.,Montavon G.,Granger G.,Péron O.
Tritium ( 3 H), the radioactive isotope of hydrogen, is a contaminant occurring in most nuclear liquid releases from nuclear industries. The behavior of tritium in the environment is an ongoing societal concern, notably the storage of tritium in organic compounds in waters, soils and sediments. In particular, the fate of tritium depends on the availability of hydrogen for isotopic exchanges in natural organic matter, especially in lignin-like molecules. Therefore, we studied here H exchangeability using natural lignite and leonardite humic matter samples. We compared results from gas–solid isotopic exchanges ( α iso ) with those from widely used methods of functional group characterization by means of deprotonation ( α depro = α carboxyl + α phenol + α alcohol ). Since standard methods for titrating total acidity and determining protonated carboxyl groups are limited by the unconstrained slow deprotonation of humic material, we have modified methods to maximize exchangeable hydrogen reactivity by extending the reaction time in reagent solutions out to 3 weeks, while total OH groups are investigated by the standard acetylation method for alcohol group determination. Results show that more than two times less hydrogen remains available for deprotonation than for isotopic exchanges with an average of α iso = 35.9% versus α depro = 15.5%. This finding reveals the existence of a neglected pool of hydrogen likely to play a key role in processes based on hydrogen exchange, such as metal complexation by natural ligands. Results also show the reliability of the isotopic exchange method for hydrogen speciation in soil-type matrices.
研究领域:
环境科学
·
放射生物学
✓ 已验证
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2018
·
IF 6.759
Yihu Dai,Xing Gao,Xiaofang Chu,Chunyang Jiang,Yao Yao,Zhen Guo,Chunmei Zhou,Chuan Wang,Hongming Wang,Yanhui Yang
A series of carbon nanotube (CNT)-supported bimetallic PtFe nanoparticles were synthesized and employed as catalysts for hydrogenation of cinnamaldehyde in pure water. A synergy between water and bimetallic PtFe catalysts has allowed the efficiently selective production of cinnamyl alcohol. With the aid of water, an initial reaction rate of >1200 h −1 and a high selectivity of >97%, as well as a good cycling stability, were achieved with a Pt 3 Fe/CNT catalyst under mild reaction conditions. Isotopic labeling studies and theoretic calculation results demonstrated that the water-involved hydrogen-exchange pathway occurred with a lower energy barrier, which coexisted with the pathway of direct H 2 dissociation–hydrogenation. This work also suggested that water participated in the catalytic hydrogenation reaction by serving as a hydrogen-exchange bridge.
研究领域:
催化化学
·
绿色化学
✓ 已验证
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2025
·
IF 1.6
Jiang Wenjia,Zhang Pingzhu,Jia Qingqing,Liu Yaming,Hu Shilin,Ruan Hao,Huang Li,Wu Dong,Zhao Zhi
Herein, a nickel foam (NF) (Φ27 mm × 2 mm) was employed as a structured carrier. First, porous nitrogen-doped carbon (N–C) was synthesized in situ on this NF via a hydrothermal method followed by activation treatment. Subsequently, Pt particles were deposited on the N–C coated NF by reducing Pt in the high-valence state using H 2 . Finally, the superhydrophobic Pt/N–C/NF catalyst was fabricated via hydrophobic modification using 1H, 1H, 2H, 2H-heptadecafluorodecyltrimethoxysilane, achieving a contact angle of 162°. Results showed that the average particle size of Pt was only 1.41 nm and that the zero-valence Pt content was 65%. These outstanding properties endowed Pt/N–C/NF with excellent catalytic activity in water–hydrogen exchange reactions, achieving a total volumetric mass transfer coefficient of 7.60 × 10 −2 s −1 .
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
REPRODUCTION
·
2023
·
IF 3.8
Min Chen,Jia-Lu Shi,Zi-Meng Zheng,Zhi Lin,Ming-Qing Li,Jun Shao
The autophagy of trophoblasts is necessary for developing and maintaining of a healthy pregnancy. Autophagy dysfunction in trophoblast cells is linked to recurrent spontaneous abortion (RSA). However, the mechanism underlying trophoblast autophagy is unknown. In this study, we investigated the expression of autophagy-related genes in both normal and RSA villi. We also examined the production of lysophosphatidic acid (LPA) and lysophosphatidic acid receptor1 (LPAR1) in trophoblast cells during early pregnancy. We found that the activation of the LPA-LPAR1 axis triggered the autophagy of trophoblast cells and increased the expression of sodium/hydrogen exchanger 1 (NHE1). Inhibition of NHE1 suppressed the autophagy in trophoblast cells and we confirmed that NHE1 regulates LPA production in trophoblast cells. Additionally, we found decreased expression of autophagy-related genes and LPAR1 in villi from RSA patients. These observations indicate that the LPA/LPAR1-NHE1 axis regulates the autophagy of trophoblast cells during pregnancy. Insufficient autophagy and poor expression of LPAR1 in trophoblast cells may result in dysfunction of the trophoblasts and increased risk of spontaneous abortion. Overall, our research elucidated that a positive LPA/LPAR1-NHE1 axis can promote the autophagy of trophoblast cells and the abnormal axis leads to the autophagy deficiency of trophoblast cells in recurrent spontaneous abortion.
研究领域:
妇产科学
·
分子生物学
·
生殖医学
✓ 已验证
DOI
PubMed
高影响因子
CATALYSIS LETTERS
·
2025
·Vol. 155
·期 9
·1-14
·
IF 2.4
Jiang Wenjia,Zhang Pingzhu,Jia Qingqing,Zhang Zhongao,Liu Yaming,Hu Shilin,Ruan Hao,Huang Li,Wu Dong,Zhao Zhi
Hydrophobic catalysts are essential for water-hydrogen exchange reactions to facilitate the separation of hydrogen isotopes. However, existing hydrophobic catalysts are primarily small-sized pelleted forms, which are not suitable for large-scale systems. In contrast, structured catalysts, which offer a low pressure drop and enhanced mass and heat transfer properties, present promising applications. In this work, cake-like nickel foam (NF) was selected as the structural support. Activated carbon was initially loaded onto the NF using silica sol, followed by hydrothermal deposition of NiCo 2 O 4 with a rough morphology, resulting in a carrier with high roughness and a large specific surface area. The carrier attained a superhydrophobic state after modification with heptadecafluorodecyltrimethoxysilane (FD-TMS), achieving a contact angle of 163.8°. The Pt/NiCo 2 O 4 /C/NF superhydrophobic catalyst was subsequently prepared by loading Pt particles via an impregnation-gas phase reduction method. This method exposes the active metal on the surface, enhancing the Pt utilization rate. Furthermore, the extensive surface area of the carrier provided numerous attachment sites for Pt, leading to smaller particle sizes and greater exposure of Pt precursors for reduction to zero-valent Pt. The results indicated that the Pt particle size in the catalyst was 2.31 nm, with 73% of the Pt in the zero-valent form. In water-hydrogen exchange reactions, the total volume mass transfer coefficient Kya for the Pt/NiCo 2 O 4 /C/NF superhydrophobic catalyst reached 17.35 × 10 –2 s –1 , indicating strong catalytic performance. Graphical abstract
研究领域:
催化
·
材料科学
·
化学工程
·
表面科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）