ABSTRACT
Earlier findings have confirmed that CO molecules have propensities to adsorb on low-coordinated gold atoms (top sites) of Au-based clusters, which can be treated by the Blyholder model wherein the σ donation and π-back donation take place. Here, the structural features and stability of (AuLi)n (n = 1-9) clusters were first analyzed using the GA-DFT method. The new adsorption modes, vibration frequencies and electronic interactions for Au-Li clusters with CO were investigated in detail. More excitingly, we found that CO prefers to adsorb on the bridge sites of the Au-Li clusters rather than on the top sites, which are much lower in energies than the top adsorptions, and the C-O stretching frequencies are also red-shifted. AIMD simulations show that the adsorption structures still have good thermal stability at 500 K. The density of states reveals that the electronic structures of Au-Li clusters have excellent stability for the bridge adsorptions of CO molecules. The ETS-NOCV analysis and NPA charges show that the direction of charge flow is from Au-Li clusters â CO. Our study provides an idea to elucidate the new adsorption mechanism on Au-Li clusters and the connection between the geometries and reaction properties.
ABSTRACT
The pyramidal Au20 cluster is a highly inert and stable superatomic molecule, but it is not suitable as a potential catalyst for covalent bond activations, e.g., CO oxidation reaction. Herein, the adsorption and electronic properties of CO molecules on various pyramidal clusters based on the structural framework of Au20 are investigated using density functional theory. According to the SVB model, we constructed isoelectronic superatomic molecules with different pyramid configurations by replacing the vertex atoms of the Au20 using metal M atoms (M = Li, Be, Ni, Cu, and Zn group atoms). After the CO molecules are adsorbed on the vertex atoms of these metal clusters, we analyzed the CO adsorption energies, C-O bond stretching frequencies, and electronic properties of the adsorption structures. It was found that the adsorption of CO molecules results in minimal changes in the parent geometries of the pyramidal clusters, and most adsorption structures are consistent with the geometry of CO adsorption at the vertex site of the Au20 cluster. There are significant red shifts when CO molecules are adsorbed on the Ni/Pd/Pt atoms of the clusters, and their CO adsorption energies were also greater. The molecular orbitals and density of states reveal that there are overlaps between the frontier orbitals of the clusters and CO, and the electronic structure of NiAu19- is not sensitive to CO. The ETS-NOCV analysis shows that the increase in the density of the bonding area caused by the orbital interactions between the fragments is higher than the decrease in the density of the bonding area caused by Pauli repulsion, presenting that the direction of charge flow in the deformation density is from CO â clusters. From energy decomposition analysis (EDA) and NPA charge, we find a predominant covalent nature of the contributions in COâ¯M interactions (σ-donation). Our study indicates that the SVB model provides a new direction to expand the superatomic catalysts from the superatom clusters, which also provides inference for the extension of the single atom catalysis.
ABSTRACT
The deformation behavior for highly purified Fe-17Cr alloy was investigated at 700~1000 °C and 0.5~10 s-1. The microstructure evolution and corresponding mechanism during deformation were studied in-depth, using electron backscattering diffraction, transmission electron microscopy and precession electron diffraction. During deformation, dynamic recrystallization (DRX) occurred, along with extensive dynamic recovery, and the active DRX mechanism depended on deformation conditions. At higher Zener-Hollomon parameter (Z ≥ 5.93 × 1027 s-1), the development of the shear band was promoted, and then continuous DRX was induced by the formation and intersection shear band. At lower Zener-Hollomon parameter (Z ≤ 3.10 × 1025 s-1), the nucleation of the new grain was attributed to the combination of continuous DRX by uniform increase in misorientation between subgrains and discontinuous DRX by grain boundary bulging, and with increasing temperature, the effect of the former became weaker, whereas the effect of the latter became stronger. The DRX grain size increased with the temperature. For alleviating ridging, it seems advantageous to activate the continuous DRX induced by shear band through hot deformation with higher Z. In addition, the modified Johnson-Cook and Arrhenius-type models by conventional way were developed, and the modified Johnson-Cook model was developed, using the proposed way, by considering strain dependency of the material parameters. The Arrhenius-type model was also modified by using the proposed way, through distinguishing stress levels for acquiring partial parameter and through employing peak stress to determine the activation energy and considering strain dependency of only other parameters for compensating strain. According to our comparative analyses, the modified Arrhenius-type model by the proposed approach, which is suggested to model hot-deformation behavior for metals having only ferrite, could offer a more accurate prediction of flow behavior as compared to other developed models.
ABSTRACT
OBJECTIVE: This study aimed to clarify the mechanism of Fei-Xian formula (FXF) in the treatment of pulmonary fibrosis based on network pharmacology analysis combined with molecular docking validation. METHODS: Firstly, ingredients in FXF with pharmacological activities, together with specific targets, were identified based on the BATMA-TCM and TCMSP databases. Then, targets associated with pulmonary fibrosis, which included pathogenic targets as well as those known therapeutic targets, were screened against the CTD, TTD, GeneCards, and DisGeNet databases. Later, Cytoscape was employed to construct a candidate component-target network of FXF for treating pulmonary fibrosis. In addition, for nodes within the as-constructed network, topological parameters were calculated using CytoHubba plug-in, and the degree value (twice as high as the median degree value for all the nodes) was adopted to select core components as well as core targets of FXF for treating pulmonary fibrosis, which were subsequently utilized for constructing the core network. Furthermore, molecular docking study was carried out on those core active ingredients together with the core targets using AutoDock Vina for verifying results of network pharmacology analysis. At last, OmicShare was employed for enrichment analysis of the core targets. RESULTS: Altogether 12 active ingredients along with 13 core targets were identified from our constructed core component-target network of FXF for the treatment of pulmonary fibrosis. As revealed by enrichment analysis, the 13 core targets mostly concentrated in regulating biological functions, like response to external stimulus (from oxidative stress, radiation, UV, chemical substances, and virus infection), apoptosis, cell cycle, aging, immune process, and protein metabolism. In addition, several pathways, like IL-17, AGE-RAGE, TNF, HIF-1, PI3K-AKT, NOD-like receptor, T/B cell receptor, and virus infection-related pathways, exerted vital parts in FXF in the treatment of pulmonary fibrosis. CONCLUSIONS: FXF can treat pulmonary fibrosis through a "multicomponent, multitarget, and multipathway" mean. Findings in this work lay foundation for further exploration of the FXF mechanism in the treatment of pulmonary fibrosis.
ABSTRACT
An-Chuan Granule (ACG), a traditional Chinese medicine (TCM) formula, is an effective treatment for asthma but its pharmacological mechanism remains poorly understood. In the present study, network pharmacology was applied to explore the potential mechanism of ACG in the treatment of asthma. The tumor necrosis factor (TNF), Toll-like receptor (TLR), and Th17 cell differentiation-related, nucleotide-binding oligomerization domain (NOD)-like receptor, and NF-kappaB pathways were identified as the most significant signaling pathways involved in the therapeutic effect of ACG on asthma. A mouse asthma model was established using ovalbumin (OVA) to verify the effect of ACG and the underlying mechanism. The results showed that ACG treatment not only attenuated the clinical symptoms, but also reduced inflammatory cell infiltration, mucus secretion and MUC5AC production in lung tissue of asthmatic mice. In addition, ACG treatment notably decreased the inflammatory cell numbers in bronchoalveolar lavage fluid (BALF) and the levels of pro-inflammatory cytokines (including IL-6, IL-17, IL-23, TNF-alpha, IL-1beta and TGF-beta) in lung tissue of asthmatic mice. In addition, ACG treatment remarkably down-regulated the expression of TLR4, p-P65, NLRP3, Caspase-1 and adenosquamous carcinoma (ASC) in lung tissue. Further, ACG treatment decreased the expression of receptor-related orphan receptor (RORγt) in lung tissue but increased that of Forkhead box (Foxp3). In conclusion, the above results demonstrate that ACG alleviates the severity of asthma in a ´multi-compound and multi-target' manner, which provides a basis for better understanding of the application of ACG in the treatment of asthma.
Subject(s)
Asthma/drug therapy , Drugs, Chinese Herbal/pharmacology , Animals , Asthma/immunology , Drugs, Chinese Herbal/therapeutic use , Forkhead Transcription Factors/metabolism , Interleukins/metabolism , Lung/drug effects , Lung/metabolism , Male , Mice , Mice, Inbred BALB C , Mucin 5AC/metabolism , NF-kappa B/metabolism , NLR Family, Pyrin Domain-Containing 3 Protein/metabolism , Nuclear Receptor Subfamily 1, Group F, Member 3/metabolism , T-Lymphocytes, Regulatory/drug effects , T-Lymphocytes, Regulatory/immunology , Th17 Cells/drug effects , Th17 Cells/immunology , Toll-Like Receptors/metabolism , Tumor Necrosis Factor-alpha/metabolismABSTRACT
BACKGROUND Intracerebral hemorrhage (ICH), a fatal type of stroke, profoundly affects public health. Yi-Qi-Huo-Xue decoction (YQHXD), a traditional Chinese medicine (TCM) prescription, is verified to be an efficient method to treat ICH stroke among the Chinese population. Nevertheless, the pharmacological mechanisms of YQHXD have been unclear. MATERIAL AND METHODS We used a strategy based on network pharmacology to explore the possible multi-component, multi-target, and multi-pathway pattern of YQHXD in treating ICH. First, candidate targets for YQHXD were identified using the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Then, these candidate YQHXD targets were used in combination with the known targets for the treatment of ICH stroke to construct the core network (cPPI) using data on protein-protein interaction (PPI). We calculated 5 topological parameters for identification of the main hubs. Pathway enrichment and GO biological process enrichment analyses were performed after the incorporation of the main hubs into ClueGO. RESULTS In total, 55 candidate YQHXD targets for ICH were recognized to be the major hubs in accordance with their topological importance. As suggested by enrichment analysis, the YQHXD targets for ICH were roughly classified into several biological processes (related to redox equilibrium, cell-cell communication, adhesion and collagen biosynthesis, cytokine generation, lymphocyte differentiation and activation, neurocyte apoptosis and development, neuroendocrine system, and vascular development) and related pathways (VEGF, mTOR, NF-kappaB, RAS/MAPK, JAK/STAT and cytokine-cytokine receptors interaction), indicating those mechanisms underlying the therapeutic effect of YQHXD. CONCLUSIONS The present results may serve as a pharmacological framework for TCM studies in the future, helping to promote the use of YQHXD in clinical treatment of ICH.
Subject(s)
Hemorrhagic Stroke/drug therapy , Gene Ontology , Hemorrhagic Stroke/metabolism , Humans , Medicine, Chinese Traditional , Protein Interaction MapsABSTRACT
OBJECTIVE: To investigate the value of the difference between peripheral arterial and venous blood gas analysis for the prognosis of patients with septic shock after resuscitation. METHODS: Patients with septic shock aged 18 to 80 years admitted to intensive care unit (ICU) of Affiliated Hospital of Integrated Traditional Chinese and Western Medicine, Nanjing University of Chinese Medicine from May 2016 to December 2017 were enrolled. The peripheral arterial blood and peripheral venous blood gas analysis were measured simultaneously after the early 6 hours resuscitation, including pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide (PCO2), base excess (BE), bicarbonate (HCO3-) and lactate (Lac) level, and the difference values between peripheral arterial and venous blood were calculated. According to the 28-day survival, the patients were divided into survival group and death group. Multiple Logistic regression analysis was used to analyze the risk factors of death, and the receiver operating characteristic curve (ROC) was used to analyze the prognostic value of blood gas analysis parameters for prognosis. RESULTS: A total of 65 patients with septic shock resuscitation were enrolled in the study, 35 survived while 30 died during the 28-day period. (1) There was no significant difference in gender, age, and mean arterial pressure (MAP), central venous pressure (CVP), central venous oxygen saturation (ScvO2) and norepinephrine (NE) dose between the two groups. (2) The arterial and venous Lac, the difference of Lac (ΔLac) and PCO2 (ΔPCO2) between arterial and venous blood in death group were significantly higher than those in survival group [arterial Lac (mmol/L): 7.40±3.10 vs. 4.82±2.91, venous Lac (mmol/L): 9.17±3.27 vs. 5.81±3.29, ΔLac (mmol/L): 1.77±0.54 vs. 0.99±0.60, ΔPCO2 (mmHg, 1 mmHg = 0.133 kPa): 9.64±5.08 vs. 6.70±3.71, all P < 0.01], and there was no significant difference in the other arterial and venous blood gas analysis index and its corresponding differential difference between two groups. (3) Multiple Logistic regression analysis showed that ΔPCO2 [ß = 0.247, odd ratio (OR) = 1.280, 95% confidential interval (95%CI) = 1.057-1.550, P = 0.011], and ΔLac (ß = 2.696, OR = 14.820, 95%CI = 2.916-75.324, P = 0.001) were the independent risk factors for the prognosis of septic shock. (4) It was shown by ROC curve analysis that arterial blood Lac, ΔLac and ΔPCO2 had predictive value on prognosis of septic shock, the area under ROC curve (AUC) was 0.792, 0.857, 0.680, respectively (all P < 0.05). When the best cut-off value of arterial Lac was 4.00 mmol/L, the sensitivity was 100%, and the specificity was 62.86% for predictor of death in 28-day; when the best cut-off value of ΔLac was 1.25 mmol/L, the sensitivity was 93.33%, and the specificity was 68.57% for predictor of death in 28-day; when the best cut-off value of ΔPCO2 was 4.35 mmHg, the sensitivity was 83.33%, and the specificity was 37.14% for predictor of death in 28-day. CONCLUSIONS: Compared to other parameters, the difference between peripheral arterial and venous blood gas analysis, ΔPCO2 and ΔLac had the best correlation with the prognosis of septic shock. The ΔPCO2 and ΔLac are the independent prognostic predictors for 28-day survival.
Subject(s)
Shock, Septic , Adolescent , Adult , Aged , Aged, 80 and over , Blood Gas Analysis , Central Venous Pressure , Humans , Middle Aged , Prognosis , Resuscitation , Young AdultABSTRACT
Based on the inhibition effect of rutin on the luminol-hydrogen peroxide chemiluminescence (CL) system catalyzed by tetrasulfonated colbalt phthalocyanine (CoTSPc), a sensitive flow-injection CL method has been developed for the determination of rutin. The CL reaction mechanism was carefully investigated by examining CL emission spectra, UV-visible spectra and variation of reaction conditions. It was found that there existed a linear relationship between CL intensity and the concentration of rutin in the range of 8.0 x 10(-9) to 1.0 x 10(-6) mol L(-1), and the detection limit is 3.8 x 10(-9) mol L(-1). This proposed method is sensitive, convenient and simple, and has been applied to the determination of rutin in commercial rutin tablets with satisfactory results.
Subject(s)
Cobalt/chemistry , Hydrogen Peroxide/chemistry , Indoles/chemistry , Luminescent Measurements/methods , Luminol/chemistry , Rutin/analysis , Sulfur/chemistry , Catalysis , Isoindoles , Luminescent Agents/chemistry , Molecular Structure , Rutin/chemistry , Tablets/analysis , Tablets/chemistryABSTRACT
The title compound, C(14)H(9)Br(3)N(2)O(2)·CH(4)O, was prepared by the reaction of 3,5-dibromo-2-hydroxy-benzaldehyde and 3-bromo-benzohydrazide in methanol. The asymmetric unit of the crystal consists of a Schiff base mol-ecule and a methanol mol-ecule of crystallization. The dihedral angle between the two benzene rings is 5.5â (2)°. An intra-molecular O-Hâ¯N hydrogen bond is observed. In the crystal structure, pairs of adjacent Schiff base mol-ecules are linked by two methanol mol-ecules through inter-molecular N-Hâ¯O and O-Hâ¯O hydrogen bonds.
ABSTRACT
The title compound, C(14)H(9)BrCl(2)N(2)O(2), was prepared by the reaction of 3,5-dichloro-2-hydroxy-benzaldehyde and 3-bromo-benzohydrazide in methanol. The dihedral angle between the two benzene rings is 13.0â (2)°. An intra-molecular O-Hâ¯N hydrogen bond is observed. The mol-ecules are linked into chains along the c axis by inter-molecular N-Hâ¯O hydrogen bonds.
ABSTRACT
The asymmetric unit of the title compound, [ZnBr(2)(C(14)H(20)N(2)O)]·H(2)O, consists of a mononuclear Schiff base zinc(II) complex mol-ecule and a solvent water mol-ecule. The Zn(II) atom is four-coordinated in an approximately tetra-hedral geometry, binding to the imine N and phenolate O atoms of the neutral zwitterionic Schiff base ligand and to two terminal Br(-) anions. In the crystal structure, mol-ecules are linked through inter-molecular O-Hâ¯Br and O-Hâ¯O hydrogen bonds, forming chains running along the b axis.