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2.
ACS Omega ; 5(7): 3498-3503, 2020 Feb 25.
Article in English | MEDLINE | ID: mdl-32118164

ABSTRACT

We prepared a series of ordered mesoporous carbons embedded with different contents of Cu nanoparticles (Cu/OMC-X) and applied them to electrocatalytic synthesis of benzyl methyl carbonate. The materials were characterized by many measurements, which showed that Cu/OMC-X materials maintain highly ordered mesoporous structures with high surface area and highly dispersed Cu nanoparticles. As expected, the materials exhibit good electrocatalytic performance. The optimal yield of benzyl methyl carbonate reaches 69.7% on Cu/OMC-3.

3.
Colloids Surf B Biointerfaces ; 183: 110458, 2019 Nov 01.
Article in English | MEDLINE | ID: mdl-31472392

ABSTRACT

Almost all clay minerals carry an abundance of surface charges. The role and impacts of surface charges during adsorption of amino acids and biochemical reactions are of great importance while currently remain elusive, which are to be tackled in this study by first-principles density functional calculations. A wide range of surface charges (-0.42˜ + 0.42 C m-2) have been considered. Distribution of different amino acid isomers and their interaction with clay minerals rely strongly on the sign and amount of surface charges. Zwitterionic structures remain stable for all negative surface charges and become dominant when negative surface charges are abundant (σ ≤ -0.28 C m-2), whereas only very high positive surface charges (σ ≥ +0.35 C m-2) can stabilize zwitterionic glycine. Increase of surface charges pronouncedly enhances the interactions of amino acids with clay minerals, which favors their gathering at clay surfaces and condensation to protein fragments. The superior binding of amino acids by negatively rather than positively charged clay minerals is due to stronger H bonding and electrostatic interactions. The biochemical reactions are greatly accelerated at higher surface charges and zwitterion formation becomes almost barrierless; however, the reverse reactions of forming canonical isomers have so moderate activation barriers that can occur facilely and get ready for the condensation to protein fragments. Accordingly, clay minerals, even in the anhydrous state, should be the suitable birthplace for life, where surface charges play a central role.


Subject(s)
Amino Acids/chemistry , Clay/chemistry , Glycine/chemistry , Minerals/chemistry , Adsorption , Hydrogen Bonding , Molecular Structure , Static Electricity , Stereoisomerism , Surface Properties
4.
Front Pharmacol ; 10: 586, 2019.
Article in English | MEDLINE | ID: mdl-31214029

ABSTRACT

Type 2 diabetes mellitus (T2DM) is prevalent, with a dramatic increase in recent years. Moreover, its microvascular and macrovascular complications cause significant societal issues. The demand for new and effective antidiabetic therapies grows with each passing day and motivates organizations and individuals to pay more attention to such products. In this article, we focused on oral antihyperglycemic drugs patented in China and introduced them according to their antihyperglycemic mechanisms. By searching the website of State Intellectual Property Office of the People's Republic of China (http://www.sipo.gov.cn), 2,500 antihyperglycemic patents for T2DM were identified and analyzed. These consisted of 4 patents for derivatives of herbal extracts (0.2%), 162 patents for herbal extracts (6.5%), 61 compositions for traditional Chinese medicine (TCM) (2.4%), 2,263 patents for synthetic compounds (90.5%), and 10 (0.4%) patents of the combination of synthetic compounds and TCM. As the most common drugs for diabetes mellitus, synthetic compounds can also be classified into several categories according to their working mechanisms, such as insulin secretion promotor agents, insulin sensitizer agents, α-glucosidase inhibitors, and so forth. This article discussed the chemical structure, potential antihyperglycemic mechanism of these antihyperglycemic drugs in patents in China. Expert opinion: Insulin sensitivity and ß-cell function could be improved by weight loss to prevent prediabetes into T2DM. However, 40-50% patients with impaired glucose tolerance (IGT) still progress to T2DM, even after successful long-term weight loss. Antihyperglycemic remedies provide a treatment option to improve insulin sensitivity and maintain ß-cell function. Combination therapy is the best treatment for diabetes. Combination therapy can reduce the dosage of each single drug option, and avoid the side effects. Drugs with different mechanisms are complementary, and are better adapted to patients with changing conditions. Classical combination therapies include combinations such as sulfonylureas plus biguanides or glucosidase inhibitors, biguanide plus glucosidase inhibitors or insulin sensitizers, insulin treatment plus biguanides or glucosidase inhibitors. The general principle of combination therapy is that two drugs with different mechanisms are selected jointly, and the combination of three types of hypoglycemic drugs is not recommended. After reading a large amount of literature, we have rarely found a case of three oral hypoglycemic agents, which may mean that the combination of three oral hypoglycemic agents is unnecessary and has unpredictable risks. There is no objection to the idea of multi-drug therapy. But multiple drugs can only be used when it shows a significant benefit to the patients. Combined use of multiple antidiabetic drugs poses a risk to patients due to drug interactions and overtreatment.

5.
Int J Mol Med ; 43(6): 2267-2278, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31017262

ABSTRACT

Among a number of mRNA modifications, N6­methyladenosine (m6A) modification is the most common type in eukaryotes and nuclear­replicating viruses. m6A has a significant role in numerous cancer types, including leukemia, brain tumors, liver cancer, breast cancer and lung cancer. Although m6A methyltransferases are essential during RNA modifications, the biological functions of m6A and the underlying mechanisms remain to be fully elucidated, predominantly due to the limited detection methods for m6A. In the present review, the currently available m6A detection methods and the respective scope of their applications are presented to facilitate the further investigation of the roles of m6A in biological process.


Subject(s)
Adenosine/analogs & derivatives , RNA/chemistry , Adenosine/analysis , Adenosine/genetics , Animals , Biosensing Techniques/methods , Blotting, Northern/methods , Chromatography, High Pressure Liquid/methods , Electrochemical Techniques/methods , Humans , Immunoblotting/methods , Immunoprecipitation/methods , Methylation , Neoplasms/genetics , RNA/genetics , Sequence Analysis, RNA/methods
6.
Chemosphere ; 217: 18-25, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30396046

ABSTRACT

Sulfur dioxide (SO2) ranks as a major air pollutant and is likely to generate acid rain. When molecular oxygen is the oxygen source, the regular surfaces of gibbsite (one of the most abundant mineral dusts) show no reactivity for SO2 conversions to H2SO4, while the partially dehydrated (100) surface with coordination-unsaturated Al sites becomes catalytically effective. Because of the easy availability of molecular oxygen, results manifest that acid rain can form under all atmospheric conditions and may account for the high conversion ratio of atmospheric SO2. The (100) and (001) surfaces show divergent catalytic effects, and hydrolysis is always the rate-limiting step. Path A (hydrolysis and then oxidation) is preferred for (100) surface, whereas a third path with obviously lower activation barriers is presented for (001) surface, which is non-existent for (100) surface. Atomic oxygen originating from the dissociation of molecular oxygen is catalytically active for (100) surface, while the active site of (001) surface fails to be recovered, suggesting that SO2 conversions over gibbsite surfaces are facet-controlled. This work also offers an environmentally friendly route for production of H2SO4 (one of the essential compounds in chemical industry), directly using molecular oxygen as the oxygen source.


Subject(s)
Acid Rain , Oxygen/chemistry , Sulfur Dioxide/chemistry , Air Pollution , Aluminum , Catalysis , Dust , Hydrolysis , Oxidation-Reduction
7.
Phys Chem Chem Phys ; 20(34): 22228-22240, 2018 Aug 29.
Article in English | MEDLINE | ID: mdl-30118125

ABSTRACT

Non-covalent interactions play a critical role during the application of carbonaceous materials. DFT calculations are presently employed to study the non-covalent interactions of graphene flakes (GFs) with ion pairs, considering the impacts of doping (electron-deficient and electron-rich) and curving (direction, curvature and surface: inner and outer) as well as their combined effects. The results are relevant to carbon nanotubes, from which curved graphene sheets can be facilely produced. Doping changes the predominant binding configurations and fundamentally affects non-covalent interactions, and all dopants enhance the binding strength, especially the electron-deficient ones that alter frontier orbitals. Curving will not alter the binding configurations but despite the lower impact compared to doping, larger curvatures may result in structural collapse. The changing trends of non-covalent interactions are opposite for inner and outer surfaces. Combined effects during non-covalent interactions are then tackled, producing four influencing factors that decrease as identity of dopant > curvature > curving direction and identity of dopant > surface. The sign of the combined effects (Ω > 0: counteractive while Ω < 0: synergetic) relies strongly on the identity of the dopants, and the other factors contribute less as elaborated in the text. Meanwhile, insightful clues about utilizing different computational methods to handle non-covalent interactions are offered. The results obtained thus far greatly further the understanding of non-covalent interactions regarding carbonaceous materials.

8.
Zhongguo Yi Liao Qi Xie Za Zhi ; 34(4): 246-9, 2010 Jul.
Article in Chinese | MEDLINE | ID: mdl-21033107

ABSTRACT

EEG signals of depression patients and normal control subjects under the states of closed eyes and mental arithmetic are investigated through the method of phase synchronization (PS) analysis. Compared with conventional quantitative EEG (qEEG) analysis, PS analysis is a powerful method which can detect the weak interaction between signals by quantifying the relationship of the instantaneous phases of the signals but excluding the influence of the amplitudes. Results suggest that the global PS index of depression in the two states are much lower than that of controls, and the left hemispheric and the inter-hemispheric PS indices of depression show significant difference from that of controls, while the right hemispheric PS index shows no significant difference between these two groups.


Subject(s)
Depression/physiopathology , Electroencephalography , Signal Processing, Computer-Assisted , Adult , Aged , Case-Control Studies , Female , Humans , Male , Middle Aged , Young Adult
9.
Brain Topogr ; 19(1-2): 21-8, 2006.
Article in English | MEDLINE | ID: mdl-17136593

ABSTRACT

Localizing interictal epileptic activities is a difficult problem in clinical practice. We report a novel noninvasive technique, resting functional magnetic resonance imaging (fMRI) with spatio-temporal independent component analysis (ICA), for localizing interictal epileptic activities. First, the fMRI data is separated into independent spatial patterns by spatial-ICA, and the patterns with Z-values larger than a threshold are selected as the potential spatial patterns of the epileptic activities. Second, the temporal series of the active points in the selected patterns are separated by temporal-ICA, and the component with the biggest Gaussian deviation (kurtosis) is selected as the representative of the epileptic discharge activity in a sub-region. Finally, those spatial sub-regions, which have distinct epileptic discharge activities confirmed by temporal-ICA are considered as the epileptic foci. This method was applied to fMRI data of six epileptic patients, and the results are consistent with the clinical assessment. Though more studies are required to validate this technique, the above preliminary results demonstrate the potential of using the resting fMRI with spatio-temporal ICA to detect and localize latent epileptic activities.


Subject(s)
Brain Mapping/methods , Epilepsy, Temporal Lobe/diagnosis , Magnetic Resonance Imaging/methods , Signal Processing, Computer-Assisted , Adult , Artifacts , Female , Humans , Male , Models, Neurological , Normal Distribution
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