scholarly journals Probing the effect of minor groove interactions on the catalytic efficiency of DNAzymes 8–17 and 10–23

2015 ◽  
Vol 11 (5) ◽  
pp. 1454-1461 ◽  
Author(s):  
Michael H. Räz ◽  
Marcel Hollenstein
Keyword(s):  
Catalytic Activity ◽  
Catalytic Efficiency ◽  
Minor Groove ◽  
Dna Enzymes ◽  
Purine Ring ◽  
Adenosine Analog

An adenosine analog devoid of the N3-nitrogen of the purine ring was incorporated into the catalytic cores of the well-known DNA enzymes 8–17 and 10–23. The results show that minor groove interactions are important for the catalytic activity and thus constitute an important feature of DNA enzymes.

Promoting inherent catalytic activity and stability of TiO2 supported Pt single-atoms at CeOx-TiO2 interfaces

2021 ◽  
Author(s):  
Mi Yoo ◽  
Eunji Kang ◽  
Hyuk Choi ◽  
Hyunwoo Ha ◽  
Han Seul Choi ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Efficiency ◽  
Reaction Centers ◽  
Next Generation ◽  
Single Atoms ◽  
General Concern

Single-atoms Single-atoms (SAs) with atomically coordinated reaction centers are considered the next generation catalyst that can reveal exceptional catalytic efficiency. However, the general concern about thermodynamic vulnerabilities of the SAs...

PHOTO-CATALYTIC ACTIVITY AND PHOTO-ABSORPTION OF PLASMA-SPRAYED NANO-STRUCTURED TiO2 COATINGS

2010 ◽  
Vol 24 (31) ◽  
pp. 6115-6127 ◽  
Author(s):  
MARYAMOSSADAT BOZORGTABAR ◽  
MEHDI SALEHI ◽  
MOHAMMADREZA RAHIMIPOUR ◽  
MOHAMMADREZA JAFARPOUR
Keyword(s):  
Catalytic Activity ◽  
Flow Rate ◽  
Test Chamber ◽  
Catalytic Efficiency ◽  
Surface Characteristics ◽  
Catalytic Performance ◽  
Atmospheric Plasma ◽  
Argon Flow Rate ◽  
Photo Catalytic Activity ◽  
Argon Flow

Titanium dioxide coatings were deposited by utilizing atmospheric plasma-spraying system. The agglomerated P25/20 nano-powder and different spraying parameters (e.g., Argon flow rate and spray distance) were used to determine their influences on the microstructure, crystalline structure, photo-absorption, and photo-catalytic performance of the coatings. The microstructure and phases of as-sprayed TiO 2 coatings were characterized by scanning electron microscope SEM and X-ray diffraction, respectively. Surface characteristics were investigated by Fourier Transform Infrared. Photo-catalytic efficiency of the elaborated samples was also determined in an environmental test chamber set-up and evaluated from the conversion rate of ethanol. The photo-absorption was determined by UV–Vis spectrophotometer. The as-sprayed TiO2 coating was photo-catalytically reactive for the degradation of ethanol. The photo-catalytic activity was influenced by spray conditions. It is found that the photo-catalytic activity is significantly influenced by anatase content, surface area, and surface state. The results showed that the argon flow rate has an influence on the microstructure, anatase content, and photo-catalytic activity of the TiO 2 coatings.

Synthesis of 1,2-Diamine Bifunctional Catalysts for the Direct Aldol Reaction Through Probing the Remote Amide Hydrogen

2019 ◽  
Vol 6 (2) ◽  
pp. 171-176
Author(s):  
Rajasekhar Dodda ◽  
Sampak Samanta ◽  
Matthew Su ◽  
John Cong-Gui Zhao
Keyword(s):  
Hydrogen Bonding ◽  
Catalytic Activity ◽  
Aldol Reaction ◽  
Catalytic Efficiency ◽  
Aldol Reactions ◽  
Catalyst Loading ◽  
Bifunctional Catalysts ◽  
Amide Hydrogen ◽  
Highly Efficient ◽  
Direct Aldol Reaction

Background: While proline can catalyze the asymmetric direct aldol reactions, its catalytic activity and catalyst turnover are both low. To improve the catalytic efficiency, many prolinebased organocatalysts have been developed. In this regard, prolinamide-based bifunctional catalysts have been demonstrated by us and others to be highly efficient catalysts for the direct aldol reactions. Results: Using the β-acetamido- and β-tosylamidoprolinamide catalysts, the highly enantio- and diastereoselective direct aldol reactions between enolizable ketones and aldehydes were achieved (up to >99% ee, 98:2 dr). A low catalyst loading of only 2-5 mol % of the β-tosylamidoprolinamide catalyst was needed to obtain the desired aldol products in good to high yields and high stereoselectivities. Methods: By carefully adjusting the hydrogen bonding ability of the remote β-amide hydrogen of the 1,2-diamine-based prolinamide bifunctional catalysts, the catalytic activity and the asymmetric induction of these catalysts were significantly improved for the direct aldol reaction between aldehydes and enolizable ketones. Conclusion: Some highly efficient 1,2-diamine-based bifunctional prolinamide catalysts have been developed through probing the remote β-amide hydrogen for its hydrogen bonding capability. These catalysts are easy to synthesize and high enantioselectivities may be achieved at very low catalyst loadings.

Highly stable and biocompatible zwitterionic dendrimer-encapsulated palladium nanoparticles that maintain their catalytic activity in bacterial solution

2018 ◽  
Vol 42 (24) ◽  
pp. 19740-19748 ◽  
Author(s):  
Longgang Wang ◽  
Jin Zhang ◽  
Xiaolei Guo ◽  
Shengfu Chen ◽  
Yanshuai Cui ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Palladium Nanoparticles ◽  
Catalytic Efficiency ◽  
Artificial Enzyme

This study offers a method for constructing an artificial enzyme (Pdn-G5MC), which maintains its catalytic efficiency in bacterial solution.

scholarly journals AuNPs-Based Thermoresponsive Nanoreactor as an Efficient Catalyst for the Reduction of 4-Nitrophenol

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 963
Author(s):  
Wei Liu ◽  
Xiaolian Zhu ◽  
Chengcheng Xu ◽  
Zhao Dai ◽  
Zhaohui Meng
Keyword(s):  
Aqueous Solution ◽  
Electron Transfer ◽  
Phase Transformation ◽  
Catalytic Activity ◽  
Catalytic Efficiency ◽  
Environmental Pollutant ◽  
Temperature Sensitive ◽  
Efficient Catalyst ◽  
Catalytic Rate ◽  
Silica Core

A new AuNPs-based thermosensitive nanoreactor (SiO2@PMBA@Au@PNIPAM) was designed and prepared by stabilizing AuNPs in the layer of poly(N,N’-methylenebisacrylamide) (PMBA) and subsequent wrapping with the temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) layer. The new nanoreactor exhibited high dispersibility and stability in aqueous solution and effectively prevented the aggregation of AuNPs caused by the phase transformation of PNIPAM. The XPS and ATR-FTIR results indicated that AuNPs could be well stabilized by PMBA due to the electron transfer between the N atoms of amide groups in the PMBA and Au atoms of AuNPs. The catalytic activity and thermoresponsive property of the new nanoreactor were invested by the reduction of the environmental pollutant, 4-nitrophenol (4-NP), with NaBH4 as a reductant. It exhibited a higher catalytic activity at 20 °C and 30 °C (below LCST of PNIPAM), but an inhibited catalytic activity at 40 °C (above LCST of PNIPAM). The PNIPAM layer played a switching role in controlling the catalytic rate by altering the reaction temperature. In addition, this nanoreactor showed an easily recyclable property due to the existence of a silica core and also preserved a rather high catalytic efficiency after 16 times of recycling.

scholarly journals Cu(II) and Fe(III) Complexes Derived from N-Acetylpyrazine-2-Carbohydrazide as Efficient Catalysts Towards Neat Microwave Assisted Oxidation of Alcohols

Catalysts ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1053 ◽  
Author(s):  
Manas Sutradhar ◽  
Tannistha Roy Barman ◽  
Armando J. L. Pombeiro ◽  
Luísa M. D. R. S. Martins
Keyword(s):  
Catalytic Activity ◽  
Ir Spectroscopy ◽  
Maximum Yield ◽  
Catalytic Efficiency ◽  
Benzyl Alcohols ◽  
X Ray ◽  
X Ray Crystallography ◽  
Microwave Assisted ◽  
Tert Butyl Hydroperoxide ◽  
Oxidation Of Alcohols

The mononuclear Cu(II) complex [Cu((kNN′O-HL)(H2O)2] (1) was synthesized using N-acetylpyrazine-2-carbohydrazide (H2L) and characterized by elemental analysis, IR spectroscopy, ESI-MS and single crystal X-ray crystallography. Two Fe(III) complexes derived from the same ligand viz, mononuclear [Fe((kNN′O-HL)Cl2] (2) and the binuclear [Fe(kNN′O-HL)Cl(μ-OMe)]2 (3) (synthesized as reported earlier), were also used in this study. The catalytic activity of these three complexes (1–3) was examined towards the oxidation of alcohols using tert-butyl hydroperoxide (TBHP) as oxidising agent under solvent-free microwave irradiation conditions. Primary and secondary benzyl alcohols (benzyl alcohol and 1-phenylethanol), and secondary aliphatic alcohols (cyclohexanol) were used as model substrates for this study. A comparison of their catalytic efficiency was performed. Complex 1 exhibited the highest activity in the presence of TEMPO as promoter for the oxidation of 1-phenylethanol with a maximum yield of 91.3% of acetophenone.

Al centre-powered graphitic nanozyme with high catalytic efficiency for pH-independent chemodynamic therapy of cancer

2020 ◽  
Vol 56 (46) ◽  
pp. 6285-6288 ◽  
Author(s):  
Jun Li ◽  
Ke Yi ◽  
Yanli Lei ◽  
Zhihe Qing ◽  
Zhen Zou ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Cancer Therapy ◽  
Reaction Kinetics ◽  
Catalytic Efficiency ◽  
High Reaction

In this work, an Al centre-powered graphitic nanozyme (Fe/Al-GNE) was developed for chemodynamic cancer therapy, which afforded pH-independent catalytic activity and high reaction kinetics.

Cobalt phosphide-based electrocatalysts: synthesis and phase catalytic activity comparison for hydrogen evolution

2016 ◽  
Vol 4 (13) ◽  
pp. 4745-4754 ◽  
Author(s):  
Yuan Pan ◽  
Yan Lin ◽  
Yinjuan Chen ◽  
Yunqi Liu ◽  
Chenguang Liu
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Crystalline Phase ◽  
Catalytic Efficiency ◽  
Cobalt Phosphide ◽  
Carbon Species ◽  
Activity Comparison

The HER catalytic efficiency of cobalt phosphide-based catalysts can be enhanced significantly by adjusting crystalline phase and carbon species structures.

scholarly journals The hepatic glycogenolysis induced by reversible ischaemia or KCN is exclusively catalysed by phosphorylase a

1988 ◽  
Vol 256 (2) ◽  
pp. 685-688 ◽  
Author(s):  
A Vandebroeck ◽  
K Uyttenhove ◽  
M Bollen ◽  
W Stalmans
Keyword(s):  
Catalytic Activity ◽  
Wistar Rats ◽  
Catalytic Efficiency ◽  
Isolated Hepatocytes ◽  
Phosphorylase Kinase ◽  
Genetic Deficiency

1. Ischaemia was applied for 30 min to the liver of Wistar rats and of gsd/gsd rats, which have a genetic deficiency of phosphorylase kinase. The rate of glycogenolysis corresponded closely to the concentration of phosphorylase a. The loss of glycogen from Wistar livers was accounted for by the intrahepatic increase in glucose plus lactate. Further, the accumulation of oligosaccharides was negligible in the gsd/gsd liver. 2. Isolated hepatocytes from Wistar and gsd/gsd rats were incubated for 40 min in the presence of either KCN or glucagon. Again, the production of glucose plus lactate was strictly dependent on the presence of phosphorylase a. However, the catalytic efficiency of phosphorylase a was about 2-fold higher in the presence of KCN. 3. We conclude that the hepatic glycogenolysis induced by anoxia and by KCN is solely mediated by phosphorylase a. The higher catalytic activity of phosphorylase a under these circumstances could be due to an increased concentration of the substrate Pi.

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