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C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 pathway as a therapeutic target and regulatory mechanism for spinal cord injury 被引量:1
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作者 Xiangzi Wang Xiaofei Niu +4 位作者 Yingkai Wang Yang Liu Cheng Yang Xuyi Chen Zhongquan Qi 《Neural Regeneration Research》 SCIE CAS 2025年第8期2231-2244,共14页
Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand... Spinal cord injury involves non-reversible damage to the central nervous system that is characterized by limited regenerative capacity and secondary inflammatory damage.The expression of the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis exhibits significant differences before and after injury.Recent studies have revealed that the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis is closely associated with secondary inflammatory responses and the recruitment of immune cells following spinal cord injury,suggesting that this axis is a novel target and regulatory control point for treatment.This review comprehensively examines the therapeutic strategies targeting the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis,along with the regenerative and repair mechanisms linking the axis to spinal cord injury.Additionally,we summarize the upstream and downstream inflammatory signaling pathways associated with spinal cord injury and the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review primarily elaborates on therapeutic strategies that target the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the latest progress of research on antagonistic drugs,along with the approaches used to exploit new therapeutic targets within the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis and the development of targeted drugs.Nevertheless,there are presently no clinical studies relating to spinal cord injury that are focusing on the C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 axis.This review aims to provide new ideas and therapeutic strategies for the future treatment of spinal cord injury. 展开更多
关键词 apoptosis C-C motif chemokine ligand 2/C-C motif chemokine receptor 2 pathway C-C motif chemokine receptor 2 antagonists chemokine ligand 2 chemokine receptor 2 inflammation macrophage microglia spinal cord injury therapeutic method
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Ligand substitution of diiron hexacarbonyl complex with aminodiphosphine to prepare diiron aminophosphine complexes relevant to[FeFe]-hydrogenases
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作者 LIU Xufeng WANG Shaojie ZHAO Peihua 《无机化学学报》 北大核心 2025年第9期1851-1858,共8页
To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(... To extend a new family of aminophosphine-coordinated[FeFe]-hydrogenase mimics for catalytic hydro-gen(H_(2))evolution,we carried out the ligand substitutions of diiron hexacarbonyl precursors[Fe_(2)(μ-X_(2)pdt)(CO)_(6)](X_(2)pdt=(SCH_(2))_(2)CX_(2),X=Me,H)with aminodiphosphines(Ph_(2)PCH_(2))_(2)NY(Y=(CH_(2))_(2)OH,(CH_(2))_(3)OH)to obtain two new diiron aminophosphine complexes[Fe_(2)(L1)(μ-Me_(2)pdt)(CO)_(5)](1)and[Fe_(2)(L2)(μ-H_(2)pdt)(CO)_(5)](2),where L1=3-[(diphe-nylphosphaneyl)methyl]oxazolidine,L2=3-[(diphenylphosphaneyl)methyl]-1,3-oxazinane.Moreover,the structures of 1 and 2 have been fully confirmed by elemental analysis,spectroscopic techniques,and single-crystal X-ray diffraction.Using cyclic voltammetry(CV),we investigated the electrochemical redox performance and proton reduc-tion activities of 1 and 2 in acetic acid(HOAc).The CV study indicates that diiron aminophosphine complexes 1 and 2 can be considered to be hydrogenase-inspired diiron molecular electrocatalysts for the reduction of protons into H 2 generation in the presence of HOAc.CCDC:2443967,1;2443969,2. 展开更多
关键词 [FeFe]-hydrogenases diiron model complexes aminophosphine ligand STRUCTURE electrochemical performance
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Enhanced effect of dimension of receptor-ligand complex and depletion effect on receptor-mediated endocytosis of nanoparticles
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作者 刘野 高庆庆 +4 位作者 刘益军 赵闯 毛宗良 胡林 刘艳辉 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期48-54,共7页
We present an extended analytical model including the depletion effect and the dimension of ligand-receptor complex, aiming to elucidate their influences on endocytosis of spherocylindrical nanoparticles (NPs). It i... We present an extended analytical model including the depletion effect and the dimension of ligand-receptor complex, aiming to elucidate their influences on endocytosis of spherocylindrical nanoparticles (NPs). It is found that the dimension of ligand-receptor complex (δ) and the depletion effect interrelatedly govern the optimal conditions of NP endocytosis. The endocytosis phase diagram constructed in the space of NP radius and relative aspect ratio indicates that the endocytosis of NP is enhanced evidently by reducing the optimal radius and the threshold radius of endocytosed NP. Meanwhile, through thermodynamic and kinetic analysis of the diffusion of receptors, the dependence of diffusion length on depletion effect and the dimension of ligand-receptor complex can be identified in great detail. For small aspect ratio, diffusion length decreases with increasing concentration c of small bioparticles in cellular environment. Endocytosis speed corresponding to large radius R and high concentration c of small bioparticles strongly depends on the increasing (2r-δ). These results may show some highlights into the conscious design of NPs for diagnostic agents and therapeutic drug delivery applications. 展开更多
关键词 cellular uptake depletion effect dimension of receptor-ligand complex elasticity theory
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RNA interference-mediated osteoprotegerin silencing increases the receptor activator of nuclear factor-kappa B ligand/osteoprotegerin ratio and promotes osteoclastogenesis
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作者 Song-Guan Wei Hui-Hong Chen +4 位作者 Liu-Rong Xie Yuan Qin Yu-Ying Mai Lin-Hui Huang Hong-Bing Liao 《World Journal of Stem Cells》 2025年第4期64-78,共15页
BACKGROUND In vivo degradation of bone scaffolds is significantly influenced by osteoclast(OC)activity,which is orchestrated by the interplay between receptor activator of nuclear factor-kappa B ligand(RANKL)and osteo... BACKGROUND In vivo degradation of bone scaffolds is significantly influenced by osteoclast(OC)activity,which is orchestrated by the interplay between receptor activator of nuclear factor-kappa B ligand(RANKL)and osteoprotegerin(OPG).The ratio of RANKL/OPG is a crucial determinant of OC-mediated bone resorption,which plays an integral role in bone remodeling and scaffold degradation.Elevated levels of RANKL relative to OPG enhance osteoclastogenesis,thereby accelerating the degradation process essential for integrating bone scaffolds into the host tissue.AIM To elucidate the effects of OPG gene silencing on osteoclastogenesis within rat bone marrow-derived mesenchymal stem cells(BMSCs).By investigating these effects,the study aimed to provide deeper insights into the regulatory mechanisms that influence bone scaffold degradation,potentially leading to improved bone repair and regeneration strategies.METHODS We employed recombinant lentiviral plasmids to silence the OPG gene in rat BMSCs to achieve the aims.The efficacy of gene silencing was assessed using quantitative reverse transcription polymerase chain reaction and western blot analysis to measure the expression levels of OPG and RANKL.Tartrate-resistant acid phosphatase staining was utilized to evaluate the formation of OCs.Additionally,co-immunoprecipitation assays were conducted to explore the interactions between RANKL and OPG proteins,further assessing the biochemical pathways involved in osteoclastogenesis.RESULTS The silencing of the OPG gene in BMSCs resulted in a significant increase in the RANKL/OPG ratio,evidenced by decreased expression levels of OPG and increased levels of RANKL.Enhanced osteoclastogenesis was observed through tartrate-resistant acid phosphatase staining,which indicated a substantial rise in OC formation in response to the altered RANKL/OPG balance.The co-immunoprecipitation assays provided concrete evidence of the direct interaction between RANKL and OPG proteins,substantiating their pivotal roles in regulating OC activity.CONCLUSION The findings from this study underscore the critical role of the RANKL/OPG axis in osteoclastogenesis.Silencing of the OPG gene in BMSCs effectively increases the RANKL/OPG ratio,promoting OC activity and potentially enhancing bone scaffold degradation.This regulatory mechanism offers a promising avenue for modulating bone remodeling processes,which is essential for effective bone repair and the successful integration of bone scaffolds into damaged sites.Future research might focus on optimizing the control of this axis to better facilitate bone tissue engineering and regenerative therapies. 展开更多
关键词 OSTEOPROTEGERIN receptor activator of nuclear factor-kappa B ligand Bone marrow-derived mesenchymal stem cells RNA interference OSTEOCLAST Bone scaffold
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Role of osteoprotegerin/receptor activator of nuclear factor kappa B/receptor activator of nuclear factor kappa B ligand axis in nonalcoholic fatty liver disease 被引量:11
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作者 Lucia Pacifico Gian Marco Andreoli +2 位作者 Miriam D'Avanzo Delia De Mitri Pasquale Pierimarchi 《World Journal of Gastroenterology》 SCIE CAS 2018年第19期2073-2082,共10页
Concomitantly with the increase in the prevalences of overweight/obesity, nonalcoholic fatty liver disease(NAFLD) has worldwide become the main cause of chronic liver disease in both adults and children. Patients with... Concomitantly with the increase in the prevalences of overweight/obesity, nonalcoholic fatty liver disease(NAFLD) has worldwide become the main cause of chronic liver disease in both adults and children. Patients with fatty liver display features of metabolic syndrome(Met S), like insulin resistance(IR), glucose intolerance, hypertension and dyslipidemia. Recently, epidemiological studies have linked obesity, Met S, and NAFLD to decreased bone mineral density and osteoporosis, highlighting an intricate interplay among bone, adipose tissue, and liver. Osteoprotegerin(OPG), an important symbol of the receptor activator of nuclear factor-B ligand/receptor activator of nuclear factor kappa B/OPG system activation, typically considered for its role in bone metabolism, may also play critical roles in the initiation and perpetuation of obesityrelated comorbidities. Clinical data have indicated that OPG concentrations are associated with hypertension, left ventricular hypertrophy, vascular calcification, endothelial dysfunction, and severity of liver damage in chronic hepatitis C. Nonetheless, the relationship between circulating OPG and IR as a key feature of Met S as well as between OPG and NAFLD remains uncertain. Thus, the aims of the present review are to provide the existent knowledge on these associations and to discuss briefly the underlying mechanisms linking OPG and NAFLD. 展开更多
关键词 Nonalcoholic fatty liver disease Insulin resistance Metabolic syndrome OSTEOPROTEGERIN receptor ACTIVATOR of NUCLEAR factor KAPPA B receptor ACTIVATOR of NUCLEAR factor KAPPA B ligand
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Neuroprotective effects of receptor imidazoline 2 and its endogenous ligand agmatine 被引量:9
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作者 Wei-Wen QIU Rong-Yuan ZHENG 《Neuroscience Bulletin》 SCIE CAS CSCD 2006年第3期187-191,共5页
Receptor imidazoline 2 (I2) is one of the imidazoline receptors with high affinity for [^3H]-idazoxan. Receptor I2, being classified into I2A and I28 subtypes, is mainly localized to the outer membrane of mitochondr... Receptor imidazoline 2 (I2) is one of the imidazoline receptors with high affinity for [^3H]-idazoxan. Receptor I2, being classified into I2A and I28 subtypes, is mainly localized to the outer membrane of mitochondria in liver, kidney and brain. Receptor I2, displaying high similarity of sequence with monoamine oxidase-B (MAO-B), is structurally related to MAO-B, but the I2 imidazoline binding site (IEBS) with ligand is distinct from the catalytic site of MAO-B. Agmatine is the endogenous ligand of receptor I2. Accumulating evidence have revealed that the activation of receptors I2 may produce neuroprotective effects by increasing expression of glial fibriUary acidic protein (GFAP) in astrocytes, inhibiting activity of MAO, reducing calcium overload in cells. Agmatine exerts neuroprotection against ischemia-hypoxia, injury, glutamateinduced neurotoxicity by activating imidazoline receptors, blocking N-methyl-D-aspartate (NMDA) receptor, inhibiting all isoforms of nitric oxide synthase (NOS), and selectively blocking the voltage-gated calcium channels (VGCC). It would be expected that agmatine is one of the potential neuroprotective agents. 展开更多
关键词 receptor IMIDAZOLINE ligand AGMATINE NEUROPROTECTION
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Synthesis and Characterization of Chiral Organogallium and Indium Complexes with Salen Ligands 被引量:3
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作者 Fu Xing GAO Cheng Jian ZHU +2 位作者 Fang YUAN Yu Hua ZHU Yi PAN 《Chinese Chemical Letters》 SCIE CAS CSCD 2003年第2期138-140,共3页
Several new chiral organogallium and indium complexes with chiral Salen (1 and 2) as anxciliary ligands have been synthesized and characterized by elemental analysis, IR, 1H NMR and Mass spectroscopy. For the gallium... Several new chiral organogallium and indium complexes with chiral Salen (1 and 2) as anxciliary ligands have been synthesized and characterized by elemental analysis, IR, 1H NMR and Mass spectroscopy. For the gallium, mono and bimetallic complexes were obtained, whereas ring closure complexes of indium were obtained. 展开更多
关键词 Chiral complex organogallium complex organoindium complex Salen ligand.
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Effects of Y(Ⅲ) Ions on the Fluorescence Properties of Ce(Ⅲ) Ion and the Organic Ligands in the Complex 被引量:3
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作者 LI Wen-lian. (Changchun Institute of Physics and the Excited State Process Laboratory, Chinese Academy of Sciences , Changchun , 1 30021 ) Takayuku Mishima , Gin-Ya Adachi and Jiro Shiokawa (Department of Applied Chemistry, Faculty of Engineering, 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 1997年第3期189-194,共6页
The enhancement effects of Y ( Ⅲ) ions on the fluorescence of Ce ( Ⅲ) in Ce ( Ⅲ)-Y ( Ⅲ)-PMMA (polymethylmethacrylate ) or Ce ( Ⅲ)-Y ( Ⅲ)-PVC (polyvinyl chloride ) complex systems were observed. The influence of ... The enhancement effects of Y ( Ⅲ) ions on the fluorescence of Ce ( Ⅲ) in Ce ( Ⅲ)-Y ( Ⅲ)-PMMA (polymethylmethacrylate ) or Ce ( Ⅲ)-Y ( Ⅲ)-PVC (polyvinyl chloride ) complex systems were observed. The influence of Y ( Ⅲ) ions on the emission spectra of PMMA ligands in PMMA-Y ( Ⅲ) and the fluorescent enhance- ment of Y( Ⅲ) on Ce( Ⅲ) emission in PMMA-Ce-Y by Y( Ⅲ) ion were studied. It was also of interest to note that when Y ( Ⅲ) ions were added into PMMA and into bpy(bipyridine ) , respectively , the emission spectrum of PMMA ligands was split into fine structure bands by Y ( Ⅲ) , and the fluorescence intensities of bpy ligands in bpy-Y ( Ⅲ) complexes were considerably increased. 展开更多
关键词 Effect Fluorescence properties Organic ligand complex
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Increased Expression of Receptor Activator of Nuclear Factor-κB Ligand in Osteoblasts from Adolescent Idiopathic Scoliosis Patients with Low Bone Mineral Density 被引量:4
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作者 周松 王渭君 +7 位作者 朱泽章 孙旭 朱锋 俞杨 钱邦平 王斌 殷刚 邱勇 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2012年第5期686-690,共5页
Persistent generalized low bone mineral density (BMD) has been reported in patients with adolescent idiopathic scoliosis (AIS).However,the exact mechanisms and causes of the low BMD in AIS patients are largely unknown... Persistent generalized low bone mineral density (BMD) has been reported in patients with adolescent idiopathic scoliosis (AIS).However,the exact mechanisms and causes of the low BMD in AIS patients are largely unknown.The purpose of this study was to examine the relationship between the receptor activator of NF-κB ligand (RANKL)/osteoprotegerin (OPG) levels in osteoblasts (OBs) from AIS patients with low BMD and with comparison made between the patients and controls.Twenty AIS patients and eight age-matched controls were included in the present study.The BMD of lumbar spine and proximal femur was measured in all subjects.OBs from the cancellous bone of each subject was harvested and primarily cultured.The mRNA and protein expression of RANKL and OPG in OBs was detected by RT-PCR and Western blotting.The results showed BMD was lower in AIS patients than in controls.A significantly higher mRNA and protein expression of RANKL was observed in OBs from AIS patients,while no significant difference was found in the expression of OPG between AIS patients and controls.As a result,RANKL/OPG ratio in patients with AIS was remarkably higher than controls.Our study preliminarily demonstrated expression of RANKL was higher in OBs from AIS patients with low BMD as compared with controls,suggesting the unbalanced RANKL/OPG ratio caused by an over-expression of RANKL in OBs may be responsible for the low BMD in AIS patients. 展开更多
关键词 adolescent idiopathic scoliosis bone mineral density OSTEOBLAST receptor activator of NF-κB ligand OSTEOPROTEGERIN
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Intercalation Assembly, Characterization and Luminescent Properties of Novel Supramolecular Composite Materials, Tb(Ⅲ) Complex with Tetrapodal Ligand-Montmorillonite 被引量:3
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作者 Jiang Wei Tang Yu +2 位作者 Xu Li Liu Weisheng Tan Minyu 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第5期537-537,共1页
Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of... Two kinds of Tb( Ⅲ ) complexes with tetrapodal ligand, [TbL(NO3)]^3+ and [TbL]^3+ (L: 1,1, 1', 1'-tera ( 2-pyridinecarboxylester )-di ( trimethylpropane)) were intercalated into the interlayer space of montmorillonite (MT) by ion exchange and coordination reaction of L with the Tb^3+ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL (NO3) ]^2+-MT and [TbL]^3+-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing (d001) approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer. 展开更多
关键词 Tb(Ⅲ) complexes with tetrapodal ligand MONTMORILLONITE supramolecular composite materials intercalation assembly luminescent properties rare earths
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Synthesis of Eu(Ⅲ) and Tb(Ⅲ) Complexes with New Aryl Amide Type Tetrapodal Ligand and Their Luminescence Properties 被引量:3
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作者 蔡正洪 谭民裕 《Journal of Rare Earths》 SCIE EI CAS CSCD 2002年第5期382-384,共3页
A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these c... A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied. 展开更多
关键词 rare earths aryl amide tetrapodal ligand Eu(Ⅲ) and Tb(Ⅲ) complexes luminescence property
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Mechanism of cleaving DNA through hydrolysis of a novel complex of Mg containing dien ligand 被引量:2
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作者 Pin YANG Ai Xin SONG Xiao Yi FAN (Institute of Molecular Science, Shanxi University, Taiyuan 030006) 《Chinese Chemical Letters》 SCIE CAS CSCD 2000年第1期35-36,共2页
A series of metal complexes were designed and synthesized and a novel binuclear magnesium complex has been selected, namely [Mg-2(dien)Cl(OH2)(2)]Cl-2 . H2O (dien=diethylene-triamine), which can cleave the plasmid pBR... A series of metal complexes were designed and synthesized and a novel binuclear magnesium complex has been selected, namely [Mg-2(dien)Cl(OH2)(2)]Cl-2 . H2O (dien=diethylene-triamine), which can cleave the plasmid pBR322 DNA effectively in close to physiological condition without adding any external materials. Through biological and chemical methods, especially the comparative experiments, we find the interaction between the complex and DNA belongs to hydrolytic mechanism. 展开更多
关键词 pBR322 DNA metal complexes dien ligand BDNPP
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Science Letters:A synthetic Toll-like receptor 2 ligand decreases allergic immune responses in a mouse rhinitis model sensitized to mite allergen 被引量:6
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作者 Cheng ZHOU Xiao-dong KANG Zhi CHEN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2008年第4期279-285,共7页
It has been proposed that activation of Toll-like receptors (TLRs) plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 (TLR2) ligand, Pam3CSK4, has been reported ... It has been proposed that activation of Toll-like receptors (TLRs) plays crucial roles in the polarization of adaptive immune responses. A synthetic Toll-like receptor 2 (TLR2) ligand, Pam3CSK4, has been reported to modulate the balance of Th1/Th2 responses. We evaluated the modulation effect of Pam3CSK4 on allergic immune response in a mouse rhinitis model sensitized to house dust mite allergen (HDM). Mice were sensitized and challenged with Dermatophagoidesfarinae allergen (Der f), and then the allergic mice were treated by Pam3CSK4. Nasal allergic symptoms and eosinophils were scored. Der f-specific cytokine responses were examined in the splenocytes and bronchoalveolar lavage fluid (BALF). Serum level of total IgE was also detected. After establishing a mouse allergic rhinitis model with HDM, we have showed that Pam3CSK4 treatment not only ameliorated the nasal allergic symptoms remarkably but also decreased the eosinophils and total inflammation cells in BALF significantly. Analysis of cytokine profile found that IFN-7 released from either BALF or stimulated splenocytes increased markedly in Pam3CSK4-treated mice, while IL-13 decreased significantly. Moreover, serum level of total IgE was significantly lower in Pam3CSK4-treated mice than in the untreated. Thus, in an allergic rhinitis mouse model developed with HDM, Pam3CSK4 was shown to exhibit an antiallergic effect, indicating its potential application in allergic diseases. 展开更多
关键词 Toll-like receptor 2 (TLR2) ligand Allergic immune response Mite allergen
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Two Novel Copper(Ⅱ) Complexes with A Novel Ligand 2,4-Di(2-aminopyridine)-6-methylpyrimidine 被引量:2
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作者 MAHai-rui WANGYao-yu +4 位作者 LIUPing LIDong-sheng SHIQi-zhen LEEGene-hsiang PENGShie-ming 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2005年第3期365-367,共3页
关键词 Novel ligand Copper(Ⅱ) complex Cystal structure SUPRAMOLECULE
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Steric hindrance effect of Schiff-base ligands on magnetic relaxation dynamics and emissive behavior of two dinuclear dysprosium complexes 被引量:4
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作者 Youdong Jiang Sourav Dey +5 位作者 Hongshan Ke Yongsheng Yang Lin Sun Gang Xie Sanping Chen Gopalan Rajaraman 《Journal of Rare Earths》 SCIE EI CAS CSCD 2023年第7期1049-1057,I0003,共10页
The self-assembly reactions between mixed-ligand and tetrahydrate dysprosium acetate in the presence of mixed organic solvents lead to two structural similar dinuclear dysprosium complexes with composition formulas of... The self-assembly reactions between mixed-ligand and tetrahydrate dysprosium acetate in the presence of mixed organic solvents lead to two structural similar dinuclear dysprosium complexes with composition formulas of Dy_(2)(L_1)_(2)(L_(2))_(2)(CH_(3)OH)_(2)·CH_(2)Cl_(2)·CH_(3)OH(1) and Dy_(2)(L_1)_(2)(L_(3))_(2)(CH_(3)OH)_(2)·CH_(3)CN(2),where L_1,L_(2) and L_(3) represent the deprotonated form of 4-tert-butyl-2-(7-methoxybenzo[d]oxazol-2-yl)phenol,(E)-1-(((3,5-di-tert-butyI-2-hydroxyphenyI)imino)methyl)naphthalen-2-ol and(E)-2,4-di-tertbutyl-6-((2-hydroxybenzylidene)amino)phenol.The tiny difference of the core structure of 1 and 2 is derived from the steric hindrance of Schiff base ligands L_(2) and L_(3).Dynamic magnetic measurements reveal that 1 and 2 show frequency-dependent out-of-phase alternating-current susceptibility signal peaks at different temperatures under zero dc field,diagnostic of single-molecule magnet behavior.The experimental derived energy barrier to magnetization reversal for 1 and 2 is 108(1),47(2) and 33(3) K.Ab initio CASSCF calculations performed on 1 and 2 suggest that the origin of the difference in magnetic properties originates from the variation in the single-ion anisotropy that arises due to minor structural variation.Further,the equation to calculate the effective energy barrier for Dy_(2) proposed earlier is found to yield an excellent agreement with the experimental results.Solid state fluorescence measurements performed on 1 and 2 demonstrate that both exhibit two ligands centered components of fluorescent emissive,in addition,with different emitting colors and chromaticity coordinates.The discrepancy of fluorescence and single molecule magnet behavior showed by 1 and 2 can be attributed to the steric hindrance effect of Schiff base ligands. 展开更多
关键词 Fluorescent single-molecule magnets Dinuclear dysprosium complexes Mixed ligand Steric hindrance Theoretical calculations Rare earths
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Construction of NIR luminescent nanoscale lanthanide complexes with new flexible Schiff base ligands 被引量:1
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作者 Bichen Yuan Junbin Tao +3 位作者 Fei Wang Chaoqun Zhu Min Li Xiaoping Yang 《Journal of Rare Earths》 SCIE EI CAS CSCD 2020年第2期143-147,共5页
Four mono-and bi-nuclear lanthanide complexes [LnL1(No3)(H2O)DMF](Ln=Nd(1) and Yb(2)) and[Ln2(L2)2(OAc)2](Ln=Nd(3) and Yb(4)) were synthesized by using two new Schiff base ligands with long(CH2)2 NH(CH2)2 backbone.The... Four mono-and bi-nuclear lanthanide complexes [LnL1(No3)(H2O)DMF](Ln=Nd(1) and Yb(2)) and[Ln2(L2)2(OAc)2](Ln=Nd(3) and Yb(4)) were synthesized by using two new Schiff base ligands with long(CH2)2 NH(CH2)2 backbone.The lengths of the Schiff base ligands are about 1.8 nm.The bi-nuclear lanthanide complexes 3 and 4 have nanoscale structures with sizes of approximately 0.7 nm×1.1 nm×1.6 nm.For 3,the molar ratio of Nd:Br:O obtained by the energy dispersive X-ray spectroscopy analysis is in agreement with the crystal structure.The chromogenic Schiff base ligands in1-4 can efficiently transfer energy to lanthanide ions,thus,these complexes exhibit the typical NIR luminescence of lanthanide ions.Interestingly,3 and 4 have higher NIR emission quantum yields(Φem)than 1 and 2,respectively. 展开更多
关键词 CONSTRUCTION SCHIFF base ligandS LANTHANIDE complexes NANOSCALE structures NIR luminescence Rare earths
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SYNTHESES,CHARACTERIZATION AND ETHYLENE POLYMERIZATION OF HALF-SANDWICH GROUP IV METAL COMPLEXES WITH TRIDENTATE [O,N,S] LIGANDS 被引量:1
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作者 Ya-lin Qiao Ping Hu 金国新 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2013年第5期760-768,共9页
A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-((2-(SC6H5)C6H4N = CHC6H2O)]- (La) and dianionic phenoxy-amine arylsulfide [O... A series of half-sandwich group IV metal complexes with tridentate monoanionic phenoxy-imine arylsulfide [O-NS] ligand [2-Bu^t4-Me-6-((2-(SC6H5)C6H4N = CHC6H2O)]- (La) and dianionic phenoxy-amine arylsulfide [O-N-S] ligand [2-Bu^t4-Me-6-((2-(SC6H5)C6H4N-CH2C6H2O)]2- (Lb) have been synthesized and characterized. Lb was obtained easily in high yield by reduction of ligand La with excess LiAlH4 in cool diethyl ether. Half-sandwich Group Ⅳ metal complexes CpTi[O-NS]Cl2 (1a), CpZr[O-NS]Cl2 (1b), CpTi[O-N-S]Cl (2a), CpZr[O-N-S]Cl (2b) and CpZr[O-N-S]Cl (2c) were synthesized by the reactions of La and Lb with CpTiCl3, CpZrCl3 and Cp ZrCl3, and characterized by IR, ^1H-NMR, ^13C-NMR and elemental analysis. In addition, an X-ray structure analysis was performed on ligand Lb. The title Group IV half-sandwich bearing tridentate [O,N,S] ligands show good catalytic activities for ethylene polymerization in the presence of methylaluminoxane (MAO) as co-catalyst up to 1.58 × 10^7 g-PE.mol-Zr-1.h-1. The good catalytic activities can be maintained even at high temperatures such as 100 ℃ exhibiting the excellent thermal stability for these half-sandwich metal pre-catalysts. 展开更多
关键词 Half-sandwich group IV metal complexes Tridentate dianionic ligands Phenoxy-imine arylsulfide ligands Catalyst Ethylene polymerization
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Expression of N-methyl-D-aspartic acid 2A-B and 2B receptors in anterior thalamic nucleus and subiculum complex of rats 被引量:1
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作者 Yuanshan Fu Xiaokai Ma Xiaoling Yue Bin Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第8期822-825,共4页
BACKGROUND:Glutamate acid ionotropic receptor N-methyl-D-aspartic acid (NMDA) takes part in long-term potentiation, thereby influencing the process of learning and memory. OBJECTIVE: To verify expression of NMDA 2... BACKGROUND:Glutamate acid ionotropic receptor N-methyl-D-aspartic acid (NMDA) takes part in long-term potentiation, thereby influencing the process of learning and memory. OBJECTIVE: To verify expression of NMDA 2A/B and 2B receptors in the anterior thalamic nucleus and subiculum complex of rats. DESIGN, TIME AND SETTING: A single-sample observation was performed at Department of Anatomy in Dalian Medical University (Dalian, Liaoning, China) from April to September in 2007. MATERIALS: Ten adult Wistar rats were used for this study, as well as rabbit anti-NMDA 2A/B and 2B antibodies. METHODS: The rats were anesthetized and perfused, followed by brain resection and coronal sectioning of the brain tissue. A 1:3 series was selected for immunohistochemistry, using antibodies specific to NMDA 2A/B and 2B receptors. Photos were taken using the Nikon image analysis system. MAIN OUTCOME MEASURES: Expression and distribution of immunohistochemistry staining of NMDA 2A/B and 2B receptor subunits. RESULTS: There were a large number of NMDA 2A/B and 2B receptor-positive neurons distributed throughout the anterior dorsal thalamic nucleus. In the anterior ventral thalamic nucleus, distribution of positive neurons was rare, staining intensity was lighter, and cell bodies were smaller compared with the anterior dorsal thalamic nucleus. In the subiculum complex, staining intensity of NMDA 2A/B and 2B-positive neurons was weakest in the molecular layer and stronger in the pyramidal layer, in particular the region with large cell bodies adjacent to the molecular layer. In the multiform layer, more positive neurons of various sizes were detected. CONCLUSION: NMDA 2A/B and 2B receptor subunits were richly distributed in the anterior thalamic nucleus, with a small difference existing between the anterior dorsal nucleus and anterior ventral nucleus. These neurons were also differentially distributed within the three layers of the subiculum complex. 展开更多
关键词 anterior thalamic nucleus learning MEMORY NMDA receptor RATS subiculum complex
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Synthesis and thermal studies of mixed ligand complexes of Cu(II), Co(II), Ni(II) and Cd(II) with mercaptotriazoles and dehydroacetic acid 被引量:2
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作者 Dina M. Fouad Ahmed Bayoumi +2 位作者 Mohamed A. ElGahami Said A. Ibrahim Abbas M. Hammam 《Natural Science》 2010年第8期817-827,共11页
A series of new mixed ligand complexes of cobalt(II), nickel(II), copper(II) and cadmium(II) have been synthesized with 3benzyl1H4[(2 methoxybenzylidine) amino]1, 2, 4triazole5 thione (MBT), 3bezyl1H4[(4chlorobenzylid... A series of new mixed ligand complexes of cobalt(II), nickel(II), copper(II) and cadmium(II) have been synthesized with 3benzyl1H4[(2 methoxybenzylidine) amino]1, 2, 4triazole5 thione (MBT), 3bezyl1H4[(4chlorobenzylidine) amino]1, 2, 4triazole5thione (CBT), 3benzyl 1H4[(4nitrobenzylidine)amino]1, 2, 4triazole 5thione (NBT) and dehydroacetic acid sodium salt (Nadha). The mixed ligand complexes have been characterized by elemental analysis, spec troscopic spectral measurements (IR, UVVis.), molar conductance, magnetic measurements and thermal studies. The stoichiometry of these com plexes is M:L1:L2 = 1:1:1, 1:2:1 or 1:1:2 where L1 = NBT, CBT and MBT and L2 = Nadha. Tetrahedral structure was proposed for all Cd(II) mixed ligand complexes while the square planar geometry was proposed for Cu(II) mixed ligand complex with NBT. Octahedral structure was proposed for Ni(II), Co(II) mixed ligand complexes and Cu(II) mixed ligand complexes with CBT and MBT ligands. The thermal decomposition study of the prepared complexes was monitored by TG, DTG and DTA analysis in dynamic nitrogen atmosphere. TG, DTG and DTA studies confirmed the chemical formulations of theses complexes. The kinetic parameters were determined from the the thermal decomposition data using the graphical methods of CoatsRedfern and HorwitzMetzger. Thermodynamic parameters were calculated using standard relations. 展开更多
关键词 MIX ligand complexes Mercaptotriazoles Dehydroacetic Acid
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Asymmetric transfer hydrogenation of ketones catalyzed by nickel complex with new PNO-type ligands 被引量:1
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作者 Zhen Rong Dong Yan Yun Li +2 位作者 Shen Luan Yu Guo Song Sun Jing Xing Gao 《Chinese Chemical Letters》 SCIE CAS CSCD 2012年第5期533-536,共4页
The new polydentate mixed-N,P,O chiral ligands have been synthesized by the condensation of bis(o-formylphenyl)- phenylphosphane and R-phenylglycinol in CHCl_3,and fully characterized by IR,NMR and EIMS spectra.Thes... The new polydentate mixed-N,P,O chiral ligands have been synthesized by the condensation of bis(o-formylphenyl)- phenylphosphane and R-phenylglycinol in CHCl_3,and fully characterized by IR,NMR and EIMS spectra.These ligands were employed with a simple Ni complex Ni(PPh_s)_2Cl_2 in situ as catalytic systems for asymmetric transfer hydrogenation of ketones,and the corresponding optical alcohols were obtained with up to 84%ee under mild conditions. 展开更多
关键词 Nickel complex NPO-type ligand Asymmetric transfer hydrogenation KETONES
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