In this paper,^(1)H NMR spectroscopy,isothermal titration calorimetry,X-ray crystallography and other characterization methods were used to investigate the interaction modes of tetramethyl cucurbit[6]uril(TMeQ[6])and ...In this paper,^(1)H NMR spectroscopy,isothermal titration calorimetry,X-ray crystallography and other characterization methods were used to investigate the interaction modes of tetramethyl cucurbit[6]uril(TMeQ[6])and three benzimidazole derivatives in an aqueous solution-solid state.The results showed that the aromatic ring moieties in the three derivatives all entered the cavity of TMeQ[6]and their substituents were located at the port of TMeQ[6],forming 1:1 host-guest inclusion complexes.The crystal structures showed that the aromatic part of the benzimidazole derivatives interacted with the cavity of TMeQ[6]via hydrogen bond interactions and the N atoms on the benzimidazole ring formed hydrogen bonds with the carbonyl oxygen of TMeQ[6].The ion-dipole interactions between[ZnCl_(4)]^(2-)and TMeQ[6]formed supramolecular self-assembly entities.展开更多
The magnetic properties of magnetosome magnetite are of interdisciplinary interest because magnetosomes are potential carriers of natural remanent magnetization and paleoenvironment, as well as novel nano-biomaterials...The magnetic properties of magnetosome magnetite are of interdisciplinary interest because magnetosomes are potential carriers of natural remanent magnetization and paleoenvironment, as well as novel nano-biomaterials in biotechnological and biomedical applications. We carried out magnetic and electron transmission microscopy analyses of fresh Magnetospirillum magneticum AMB-1 whole cells and isolated magnetosomes. Results revealed that AMB-1 synthesized single-domain magnetite magneto-somes, which are arranged in the form of linear fragmental chain. The distinct differences of magnetic properties between these two samples can be faithfully interpreted in terms of spatial arrangement of magnetosomes and magnetostatic interaction. For the whole cells, the strong intra-chain interactions and weak inter-chain interactions generate behaviors of non-interacting uniaxial single-domain particles. Its δ-ratio is 3.0 and passes the Moskowitz test. In contrast, the isolated magnetosome sample has reduced values of coercivity and δ-ratio (1.5), due to increasing three-dimensional magnetostatic interactions and collapse of magneto-some chains. These observations provide useful insights into applications of the biogenic magnetite (magnetosomes) in magnetic nano-materials and magnetofossils in the paleomagnetic and environmental magnetism.展开更多
The complex regulatory network between microRNAs and gene expression remains an unclear domain of active research.We proposed to address in part this complex regulation with a novel approach for the genome-wide identi...The complex regulatory network between microRNAs and gene expression remains an unclear domain of active research.We proposed to address in part this complex regulation with a novel approach for the genome-wide identification of biomodules derived from paired microRNA and mRNA profiles,which could reveal correlations associated with a complex network of dys-regulation in human cancer.Two published expression datasets for 68 samples with 11 distinct types of epithelial cancers and 21 samples of normal tissues were used,containing microRNA expression and gene expression profiles,respectively.As results,the microRNA expression used jointly with mRNA expression can provide better classifiers of epithelial cancers against normal epithelial tissue than either dataset alone(P=1×10-10,F-test).We identified a combination of 6 microRNA-mRNA biomodules that optimally classified epithelial cancers from normal epithelial tissue(total accuracy = 93.3%;95% confidence intervals:86%-97%),using penalized logistic regression(PLR) algorithm and three-fold cross-validation.Three of these biomodules are individually sufficient to cluster epithelial cancers from normal tissue using mutual information distance.The biomodules contain 10 distinct microRNAs and 98 distinct genes,including well known tumor markers such as miR-15a,miR-30e,IRAK1,TGFBR2,DUSP16,CDC25B and PDCD2.In addition,there is a significant enrichment(Fisher's exact test P=3×10-10) between putative microRNA-target gene pairs reported in 5 microRNA target databases and the inversely correlated microRNA-mRNA pairs in the biomodules.Further,microRNAs and genes in the biomodules were found in abstracts mentioning epithelial cancers(Fisher's Exact test,unadjusted P<0.05).Taken together,these results strongly suggest that the discovered microRNA-mRNA biomodules correspond to regulatory mechanisms common to human epithelial cancer samples.In conclusion,we developed and evaluated a novel comprehensive method to systematically identify,on a genome scale,microRNA-mRNA expression biomodules common to distinct cancers of the same tissue.These biomodules also comprise novel microRNA and genes as well as an imputed regulatory network,which may accelerate the work of cancer biologists as large regulatory maps of cancers can be drawn efficiently for hypothesis generation.展开更多
The host-guest interactions between cyclopentanocucurbit-[6]uril(CyP_(6)Q[6])as host and six alkyl imidazolium hydrochloride as guests(g1,g2,g3,g4,g5,and g6)have been studied by various techniques,such as^(1)H NMR spe...The host-guest interactions between cyclopentanocucurbit-[6]uril(CyP_(6)Q[6])as host and six alkyl imidazolium hydrochloride as guests(g1,g2,g3,g4,g5,and g6)have been studied by various techniques,such as^(1)H NMR spectroscopy,isothermal titration calorimetry,mass spectrometry,and single-crystal X-ray diffraction analysis.The experimental results showed that CyP6Q[6]formed 1:1 inclusion complexes with each of guests g1-g6.The part of the guest entered the cavity of CyP_(6)Q[6]changes as the alkyl chain increases in length.It can be seen that the length of the alkyl chain plays a key role in determining the mode of host-guest interactions.展开更多
基金supported by the National Natural Science Foundation of China(No.22161010)。
文摘In this paper,^(1)H NMR spectroscopy,isothermal titration calorimetry,X-ray crystallography and other characterization methods were used to investigate the interaction modes of tetramethyl cucurbit[6]uril(TMeQ[6])and three benzimidazole derivatives in an aqueous solution-solid state.The results showed that the aromatic ring moieties in the three derivatives all entered the cavity of TMeQ[6]and their substituents were located at the port of TMeQ[6],forming 1:1 host-guest inclusion complexes.The crystal structures showed that the aromatic part of the benzimidazole derivatives interacted with the cavity of TMeQ[6]via hydrogen bond interactions and the N atoms on the benzimidazole ring formed hydrogen bonds with the carbonyl oxygen of TMeQ[6].The ion-dipole interactions between[ZnCl_(4)]^(2-)and TMeQ[6]formed supramolecular self-assembly entities.
基金supported by the National Natural Science Foundation of China (Grant Nos. 40821091 and 40325011)Hundred Talents Program of the Chi-nese Academy of Sciences and Marie-Curie Fellowship (IIF) Return Phase of (Grant No. MIF1-CT-2005-007555)
文摘The magnetic properties of magnetosome magnetite are of interdisciplinary interest because magnetosomes are potential carriers of natural remanent magnetization and paleoenvironment, as well as novel nano-biomaterials in biotechnological and biomedical applications. We carried out magnetic and electron transmission microscopy analyses of fresh Magnetospirillum magneticum AMB-1 whole cells and isolated magnetosomes. Results revealed that AMB-1 synthesized single-domain magnetite magneto-somes, which are arranged in the form of linear fragmental chain. The distinct differences of magnetic properties between these two samples can be faithfully interpreted in terms of spatial arrangement of magnetosomes and magnetostatic interaction. For the whole cells, the strong intra-chain interactions and weak inter-chain interactions generate behaviors of non-interacting uniaxial single-domain particles. Its δ-ratio is 3.0 and passes the Moskowitz test. In contrast, the isolated magnetosome sample has reduced values of coercivity and δ-ratio (1.5), due to increasing three-dimensional magnetostatic interactions and collapse of magneto-some chains. These observations provide useful insights into applications of the biogenic magnetite (magnetosomes) in magnetic nano-materials and magnetofossils in the paleomagnetic and environmental magnetism.
基金supported by the National Natural Science Foundation of China (60971099,60671018 and 60771024)Center for Multilevel Analyses of Genomic and Cellular Networks (1U54CA121852-01A1)the Cancer Research Foundation
文摘The complex regulatory network between microRNAs and gene expression remains an unclear domain of active research.We proposed to address in part this complex regulation with a novel approach for the genome-wide identification of biomodules derived from paired microRNA and mRNA profiles,which could reveal correlations associated with a complex network of dys-regulation in human cancer.Two published expression datasets for 68 samples with 11 distinct types of epithelial cancers and 21 samples of normal tissues were used,containing microRNA expression and gene expression profiles,respectively.As results,the microRNA expression used jointly with mRNA expression can provide better classifiers of epithelial cancers against normal epithelial tissue than either dataset alone(P=1×10-10,F-test).We identified a combination of 6 microRNA-mRNA biomodules that optimally classified epithelial cancers from normal epithelial tissue(total accuracy = 93.3%;95% confidence intervals:86%-97%),using penalized logistic regression(PLR) algorithm and three-fold cross-validation.Three of these biomodules are individually sufficient to cluster epithelial cancers from normal tissue using mutual information distance.The biomodules contain 10 distinct microRNAs and 98 distinct genes,including well known tumor markers such as miR-15a,miR-30e,IRAK1,TGFBR2,DUSP16,CDC25B and PDCD2.In addition,there is a significant enrichment(Fisher's exact test P=3×10-10) between putative microRNA-target gene pairs reported in 5 microRNA target databases and the inversely correlated microRNA-mRNA pairs in the biomodules.Further,microRNAs and genes in the biomodules were found in abstracts mentioning epithelial cancers(Fisher's Exact test,unadjusted P<0.05).Taken together,these results strongly suggest that the discovered microRNA-mRNA biomodules correspond to regulatory mechanisms common to human epithelial cancer samples.In conclusion,we developed and evaluated a novel comprehensive method to systematically identify,on a genome scale,microRNA-mRNA expression biomodules common to distinct cancers of the same tissue.These biomodules also comprise novel microRNA and genes as well as an imputed regulatory network,which may accelerate the work of cancer biologists as large regulatory maps of cancers can be drawn efficiently for hypothesis generation.
基金This work was supported by the National Natural Science Foundation of China(No.21762011)the Guizhou Science and Technology Planning Project,China(Guizhou Science and Technology Cooperation Platform Talent)(No.20175788)the Guizhou Province Graduate Education Innovation Project,China[No.YJSCXJH(2020)188].
文摘The host-guest interactions between cyclopentanocucurbit-[6]uril(CyP_(6)Q[6])as host and six alkyl imidazolium hydrochloride as guests(g1,g2,g3,g4,g5,and g6)have been studied by various techniques,such as^(1)H NMR spectroscopy,isothermal titration calorimetry,mass spectrometry,and single-crystal X-ray diffraction analysis.The experimental results showed that CyP6Q[6]formed 1:1 inclusion complexes with each of guests g1-g6.The part of the guest entered the cavity of CyP_(6)Q[6]changes as the alkyl chain increases in length.It can be seen that the length of the alkyl chain plays a key role in determining the mode of host-guest interactions.
