Impact of solvent substitution on kinetically controlled transmetalation behaviours in a MOF

2020 ◽  
Vol 44 (34) ◽  
pp. 14679-14685
Author(s):  
Wen Chen ◽  
Haoyue Zhang ◽  
Ang Qiao ◽  
Haizheng Tao

Transmetalation-induced amorphization and decreased chemical stability are confirmed by DSC, XRD and SEM.

2019 ◽  
Author(s):  
Terry Gani ◽  
Michael Orella ◽  
Eric Anderson ◽  
Michael Stone ◽  
Fikile Brushett ◽  
...  

Lignin is an abundant biopolymer important for plant function while holding promise as a renewable source of valuable chemicals. Although the lignification process in plant cell walls has been long-studied, a comprehensive, mechanistic understanding on the molecular scale remains elusive. A better understanding of lignification will lead to improved atomistic models of the plant cell wall that could, in turn, inform effective strategies for biomass valorization. Here, using first-principles quantum chemical calculations, we show that a simple model of kinetically-controlled radical coupling broadly rationalizes qualitative experimental observations of lignin structure across a wide variety of biomass types, thus paving the way for predictive, first-principles models of lignification while highlighting the ability of computational chemistry to help illuminate complex biological processes.


2009 ◽  
Vol 25 (1) ◽  
pp. 63-67
Author(s):  
Hao-Yang XIONG ◽  
Bin-Bin HU ◽  
Zhong-Hui XUE ◽  
Li CAI ◽  
Shu-Xi DAI ◽  
...  

1981 ◽  
Vol 46 (11) ◽  
pp. 2669-2675 ◽  
Author(s):  
Ivo Paseka

Hydrogenation of nitrogen oxide in acid solutions on Pt-C catalysts proceeds in dependence on experimental conditions either in purely diffusion region or in the diffusion and kinetically controlled region. The boundary between these two processes shifts to the higher ratio of NO to H2 partial pressures with increasing platinum content and decreasing intensity of agitation.


2018 ◽  
pp. 1656-1662 ◽  
Author(s):  
Mojtaba Raeisi ◽  
Mohammad Hashemi ◽  
Majid Aminzare ◽  
Asma Afshari ◽  
Tayebeh Zeinali ◽  
...  

Background and Aim: Extending the shelf life of foods is an essential concept in food safety. Most of the time, foods deteriorate through the growth of microorganisms or oxidation process. Essential oils (EOs) derived from plant material have well-documented antioxidant and antibacterial activity. This study aimed to evaluate the effect of Zataria multiflora Boiss EO (ZEO) and Mentha piperita EO (MEO) on the chemical stability of minced meat during storage at 7°C. Materials and Methods: Total phenolic content, β-Carotene bleaching test, ferric reducing antioxidant potential assay, and 2,2-Diphenyl-1-picrylhydrazyl radical scavenging activity were used to determine the antioxidant potential of EOs. Five different groups including control, ZEO 0.3%, ZEO 0.5%, MEO 0.3%, and MEO 0.5% were designed to assess the chemical stability of minced meat by measuring pH, thiobarbituric acid (TBA), total volatile base nitrogen (TVBN), and peroxide value (PV). Results: pH did not have any significant change during storage. TBA values in the control group were significantly higher than the treatment groups, especially from the 5th day of storage. TVBN in the treatment group was significantly lower than the control group during storage. PV values in the treatment group were significantly lower than the control group during storage. Conclusion: Results indicate that ZEO and MEO had an excellent antioxidant activity and retarded the spoilage process in minced meat. Keywords: antioxidant, Mentha piperita, minced meat, Zataria multiflora Boiss.


Author(s):  
Madhu Ramesh ◽  
Kolla Rajasekhar ◽  
Kavya Gupta ◽  
Vardhaman Babagond ◽  
Deepak Kumar Saini ◽  
...  

A far-red turn-on fluorescent probe (Mito-TG) with excellent biocompatibility, photostability, chemical stability targets mitochondrial matrix. The insensitivity of probe under different pH and ROS enabled tracking of mitophagy and Aβ induced mitochondrial dynamics.


2021 ◽  
Author(s):  
Tao Li ◽  
Xuefeng Chang ◽  
Lifang Mei ◽  
Xiayun Shu ◽  
Jidong Ma ◽  
...  

Ti3C2Tx is a promising new two-dimensional layered material for supercapacitors with good electrical conductivity and chemical stability. However, Ti3C2Tx has problems such as collapse of the layered structure and low...


2020 ◽  
pp. 088532822097735
Author(s):  
Fedra P Zaribaf ◽  
Harinderjit S Gill ◽  
Elise C Pegg

Ultra-high molecular weight polyethylene (UHMWPE) can be made radiopaque for medical imaging applications through the diffusion of an iodised oil-based contrast agent (Lipiodol Ultra Fluid). A similar process is used for Vitamin E incorporated polyethylene which provides antioxidant properties. This study aimed to investigate the critical long-term properties of oil-infused medical polyethylene after 4 weeks of accelerated thermal ageing. Samples treated with an oil (Vitamin E or Lipiodol) had a higher oxidation stability than currently used medical grade polyethylene, indicated by a smaller increase in oxidation index after ageing (Vitamin E + 36%, Lipiodol +40%, Untreated +136%, Thermally treated +164%). The tensile properties of oil treated polyethylene after ageing were significantly higher than the Untreated and Thermally treated controls (p<0.05) indicating less mechanical degradation. There was also no alteration in the percentage crystallinity of oil treated samples after ageing, though the radiopacity of the Lipiodol treated samples reduced by 54% after ageing. The leaching of oil with time was also investigated; the leaching of Lipiodol and Vitamin E followed the same trend and reached a steady state by two weeks. Overall, it can be concluded that the diffusion of an oil-based fluid into polyethylene not only increases the oxidative and chemical stability of polyethylene but also adds additional functionality (e.g. radiopacity) providing a more suitable material for long–term medical applications.


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