Valleytronics is an emergent discipline in condensed matter physics and offers a new way to encode and manipulate information based on the valley degree of freedom in materials. Among the various materials being studi...Valleytronics is an emergent discipline in condensed matter physics and offers a new way to encode and manipulate information based on the valley degree of freedom in materials. Among the various materials being studied, Kekulé distorted graphene has emerged as a promising material for valleytronics applications. Graphene can be artificially distorted to form the Kekulé structures rendering the valley-related interaction. In this work, we review the recent progress of research on Kekulé structures of graphene and focus on the modified electronic bands due to different Kekulé distortions as well as their effects on the transport properties of electrons. We systematically discuss how the valley-related interaction in the Kekulé structures was used to control and affect the valley transport including the valley generation, manipulation, and detection. This article summarizes the current challenges and prospects for further research on Kekulé distorted graphene and its potential applications in valleytronics.展开更多
To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The ...To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity (GS) values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions (0.447), while Australia accessions have the furthest distance (0.503). A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.展开更多
The absorption, fluorescence and Raman spectra of Ce(NO3)(3)(phen)(2) complex were assigned and the crystal structure of the complex was studied. Meanwhile the interactions between Cc (NO3)(3) (phen)(2) and DNA were s...The absorption, fluorescence and Raman spectra of Ce(NO3)(3)(phen)(2) complex were assigned and the crystal structure of the complex was studied. Meanwhile the interactions between Cc (NO3)(3) (phen)(2) and DNA were studied by spectrum methods. As DNA was added, it is found that both the UV absorption bands of Ce(NO3)(3)(phen)(2) and the SERS bands of Ce(NO3)(3)(phen)(2) weaken evidently, while the fluorescence intensity of Ce(NO3)(3)(phen)(2) enhance dramatically. The complex compete against EB on the reaction with DNA. It is indicated by this spectrum methods that there are strong interactions between Ce(NO3)(3)(phen)(2) and DNA, and the bond mode is intercalation. The bond constant of the complex with DNA is determined to be 1.7 x 10(5).展开更多
The novel dinuclear copper complex [Cu2(H20)2(DMF)2(L)2] (1, H2L = 5-phenyl- 2H-1,2,3-triazole-4-carboxylic acid, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by X-ray single-crystal di...The novel dinuclear copper complex [Cu2(H20)2(DMF)2(L)2] (1, H2L = 5-phenyl- 2H-1,2,3-triazole-4-carboxylic acid, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by X-ray single-crystal diffraction. The compound crystallizes in triclinic system, space group P1 with a = 9.591, b = 10.508, c = 15.515A,β = 75.11°, V= 1446.2 A3, Z= 2, Mr = 683.62, Dc = 1.570 g/cm3, μ = 1.531 mm^-1, F(000) = 700, the final R = 0.0404 and wR = 0.1130 for 5327 observed reflections with I 〉 2σ(I). In each unit of the complex, two Cu2+ ions coordinated with two triazole ligands to form a dimeric [5,6,5] tricyclic structure. The central Cu atom is five-coordinated, and each copper atom shows a square pyramidal geometry. The crystal structure is stabilized by the inversion-related O-H…O hydrogen bond and C-H…O hydrogen bonding interactions to form a layer structure. Fluorescent spectra show an obvious quenching of fluorescence compared with free 1,2,3-triazole ligand. The results of agarose gel electrophoresis indicate that this complex can cleave the plasmid supercoiled DNA within shorter time in the 50-folds excess of ascorbate under physiological conditions, providing a new example in the research for artificial metal nucleic acid enzyme.展开更多
A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic ...A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.展开更多
Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) compounds(1~3) based on 2-(2-pyridyl)benzothiazole(bpt) and terephthalic acid(PTA) were synthesized. The crystal structures of [Zn(bpt)(PTA)2](1), [Ni(bpt)(PTA)2](2), and [Co(bpt)(PTA)2](3) ...Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) compounds(1~3) based on 2-(2-pyridyl)benzothiazole(bpt) and terephthalic acid(PTA) were synthesized. The crystal structures of [Zn(bpt)(PTA)2](1), [Ni(bpt)(PTA)2](2), and [Co(bpt)(PTA)2](3) have been determined by single-crystal X-ray diffraction analysis, which shows that all the three complexes belong to monoclinic system with space group P21/c. Time-dependent density functional theory(TD-DFT) calculation is performed on a reference structure of compound 3. The excited electrons mainly localized at the π* of ligand 2-(2-pyridyl)benzothiazole, which will be convenient for them to bind with the DNA reacting sites. Fluorescence spectroscopy, ultraviolet(UV) spectroscopy and viscosity were used to characterize the interaction of the compounds with Calf thymus DNA(CT-DNA). The results indicate that compounds 1~3 bind to CT-DNA and have a strong interaction with DNA. The compounds can probably bind to CT-DNA via a non-intercalative mode as concluded by studying the viscosity of a DNA solution in the presence of the compounds. This combination can effectively break DNA, which speculates that these three compounds may interact with the cancer cell DNA in this binding mode, thereby damaging the cancer cells.展开更多
The title compound, N-(benzimidazol-2-ylmethyl)-5-chlorosalicylideneimine, has been synthesized and characterized by X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n, wit...The title compound, N-(benzimidazol-2-ylmethyl)-5-chlorosalicylideneimine, has been synthesized and characterized by X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n, with a = 8.3765(2), b = 18.1398(4), c = 9.4764(3)А, β= 112.141(2)°, V= 1333.74(6)А^3, Mr = 285.73, Z = 4, Dc = 1.423 g/cm^3, F(000) = 592,/z = 0.285 mm^-1, the final R = 0.0538 and wR = 0.1456 for 1917 observed reflections with I〉2σ-(I). The fluorescence quenching of the title compound by DNA with Stern-Volmer constant of 2.8×104 M^-1 indicates that it binds to double-stranded DNA in a partial intercalation mode.展开更多
A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffrac...A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic space group P2 1 /c with a=11.218(3),b=9.355(3),c=13.449(4),β=108.722(4)°,V=1336.8(6)3,Z=2,Dc=2.008 g/cm 3,μ(MoKα)=7.024 mm-1,F(000)=806,S=0.999,the final R=0.0342 and wR=0.0641for2611observed reflections (I〉2σ(I)).The central copper(Ⅱ) is four-coordinate and bonds to two nitrogen and two oxygen atoms from two Schiff base ligands.The complex is linked into a two-dimensional supramolecular structure by weak intermolecular interactions.In addition,DNA-binding properties of the metal complex were investigated using spectrometric titrations and viscosity measurements.The results show that the complex binds with calf-thymus DNA(CT-DNA),presumably via a partial intercalative mode.The intrinsic binding constant of the Cu(Ⅱ) complex with DNA is 7.335×10 3 M-1.展开更多
In this study, the entire mitochondrial DNA(mtDNA) control region(CR) of Pholis fangi was amplified via polymerase chain reaction followed by direct sequencing. The length of the mtDNA CR consensus sequence of P. fang...In this study, the entire mitochondrial DNA(mtDNA) control region(CR) of Pholis fangi was amplified via polymerase chain reaction followed by direct sequencing. The length of the mtDNA CR consensus sequence of P. fangi was 853 bp in length. In accordance with the recognition sites as were previously reported in fish species, the mtDNA CR sequence of P. fangi can be divided into 3 domains, i.e., the extended terminal associated sequence(ETAS), the central conserved sequence block(CSB), and the CSB domain. In addition, the following structures were identified in the mtDNA CR sequence of P. fangi: 2 ETASs in the ETAS domain(TAS and cTAS), 6 CSBs in the central CSB domain(CSB-F to CSB-A), and 3 CSBs in the CSB domain(CSB-1 to CSB-3). These demonstrated that the structure of the mtDNA CR of P. fangi was substantially different from those of most other fish species. The mtDNA CR sequence of P. fangi contained one conserved region from 656 bp to 815 bp. Similar to most other fish species, P. fangi has no tandem repeat sequences in its mtDNA CR sequence. Phylogenetic analysis based on the complete mtDNA CR sequences showed that there were no genetic differences within P. fangi populations of the same geographical origin and between P. fangi populations of different geographical origins.展开更多
Pholis fangi is an ecologically important fish species inhabiting Chinese coastal waters of Yellow Sea and Bohai Sea. To investigate the genetic diversity and population genetic structure of P. fangi, a fragment of 48...Pholis fangi is an ecologically important fish species inhabiting Chinese coastal waters of Yellow Sea and Bohai Sea. To investigate the genetic diversity and population genetic structure of P. fangi, a fragment of 487 bp in the first hypervariable region (HVR-1) of the mitochondrial DNA (mtDNA) control region was sequenced for 181 individuals collected from Bohai Sea and Yel- low Sea. A total of 18 polymorphic sites were detected, which defined 25 haplotypes. A moderate level of haplotype diversity (h = 0.7052) and a low level of nucleotide diversity (π= 0.0028) were detected. Both the phylogenetic tree and the haplotype network showed no significant genealogical structure difference among sampling locations. Pairwise FST comparison and hierarchical mo- lecular variance analysis (AMOVA) revealed that no significant genetic structure difference existed throughout the investigated re- gions, suggesting a high gene exchange among different populations. The results of neutrality test and mismatch distribution analysis indicated that a late Pleistocene population expansion (38000 127000 years ago) happened. Seasonal schooling migration may con- tribute to the genetically homogeneous population structure of the species.展开更多
The title complex [ NH3 CH2 CH ( NH2 ) CH3 ]2 [ M ( Ⅵ ) O2 ( OC6 H4 O)2 ] ( M = Mo0. 6 W0.4 ) was synthesized via a simple solution-phase ehemieal route. The determination of single erystal X-ray diffraction ...The title complex [ NH3 CH2 CH ( NH2 ) CH3 ]2 [ M ( Ⅵ ) O2 ( OC6 H4 O)2 ] ( M = Mo0. 6 W0.4 ) was synthesized via a simple solution-phase ehemieal route. The determination of single erystal X-ray diffraction revealed that the title eompound is erystallized in a monoelinie system with P2( 1 )/n spaee group, a = 1. 0913(10) nm, b = 1. 0442(10) nm, c=1.8842(19) nm, α=90°, β=96.530(17)°, γ=90°, Z=4, and V=2.133(4) nm^3. The mononuelear anionie unit [ M ( Ⅵ ) O2 ( 0C6 H4 O) 2 ] 2 - displays ehiral pseudo-oetahedral [ MO6 ] eoordination geometry and is linked by ehiral eations via hydrogen bond and π…π stacking interaetion. The transmission electron microseopy images show that the title eomplex is eomprised of nano-partieles with diameters ranging from 20 to 50 nm. The NMR study shows the ^1H downfield chemical shifts of [ NH3 CHa Hb CH ( NH2 ) CH3 ]^+ eations in the title eomplex when it is mixed with adenosine-triphosphate( ATP), and the chemical shift difference between Ha and Hb is inereased greatly, and most of the eateeholate ligands dissociate from the eentral metal atoms. The DNA cleavage aetivity experiment reveals that DNA eleavage promoted by the title eomplex is lower than that by Na2 MoO4 whieh possesses antitumor propetty, but higher than that by Na2WO4.展开更多
The Schiff base organotin(IV) complex {[4-Et2NC6H3(O)C=NC6H3(O)-5-NO2](n- Bu2Sn)}2 has been synthesized via the reaction between 4-(diethylamino) salicylaldehyde-2-arnino- 4-nitrophenol Schiff base (H2L) a...The Schiff base organotin(IV) complex {[4-Et2NC6H3(O)C=NC6H3(O)-5-NO2](n- Bu2Sn)}2 has been synthesized via the reaction between 4-(diethylamino) salicylaldehyde-2-arnino- 4-nitrophenol Schiff base (H2L) and dibutyltin oxide. Complex C1 has been characterized by IR, 1H NMR, 13C NMR spectra, and elemental analysis, and its crystal structure was determined by X-ray diffraction, It crystallizes in the monoclinic system, space group P21/n with a = 15.6559(8), b = 9.1657(5), c = 18.8351(10) ]A, β = 107.3440(10)°, Z = 4, V = 2579.9(2) A3, Dc = 1.442 Mg.m-3, μ(MoKa) = 1.025 mm-1, F(000) = 1152, R = 0.0250 and wR = 0.0633. The central Sn atom is coordinated in a hexadentate manner to assume a distorted octahedral configuration. Complex C1 was studied by TGA analysis in air atmosphere. The interaction between complex C1 and the herring sperm DNA was realized through the intercalation of the complex based on the studies by EB fluorescent probe.展开更多
A new complex [Ni(phen)(mal)(H2O)2]·3H2O (phen = 1,10-phenanthroline, real^2- = malonic acid) has been synthesized by the reaction of nickel nitrate, phen and malonic acid. EA, IR spectra and X-ray single...A new complex [Ni(phen)(mal)(H2O)2]·3H2O (phen = 1,10-phenanthroline, real^2- = malonic acid) has been synthesized by the reaction of nickel nitrate, phen and malonic acid. EA, IR spectra and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure of the title complex. Crystal data: monoclinic system, space group P2/c,α = 8.937(3), b = 12.163(5), c = 9.725(3) A,β = 119.36°, C15H19N2O9Ni,Mr= 430.03, Z = 2, F(000) = 446, V= 921.3 A3, Dc = 1.550 g/cm^3, μ= 1.104 mm^-1, -10≤h≤10, -12≤k≤ 14, -11≤1≤7, R = 0.0261 and wR = 0.0609 for 4376 (Rint = 0.0203) independent reflections and 1631 observed ones (I 〉 2σ(I)). Ni(Ⅱ) exhibits an octahedral coordination geometry, with hydrogen bonds and π-π interactions stabilizing the whole structure. UV spectrum of the complex interacting with protamine DNA indicates that the title compound interacts with DNA via insertion mode with bonding constant Kb of 1. 11 × 10^4.展开更多
The paper was to explore the effect of cryopreservation on DNA integrity and morphological structure of boar sperm, and to explore the protective effect of trehalose and lactose on frozen boar sperm. The morphology, u...The paper was to explore the effect of cryopreservation on DNA integrity and morphological structure of boar sperm, and to explore the protective effect of trehalose and lactose on frozen boar sperm. The morphology, ultrastructure and DNA integrity of sperms were observed by phase contract microscope, scanning electron microscope (SEM) and acridine orange (AO) staining, respectively. The results showed that the normal morphological rate and DNA integrity rate of fro- zen sperms were significantly lower than that of fresh sperms (95.5% and 94.7%, respectively), and the difference between two frozen groups was also significant (P 〈 0.05 ). The normal morphological rates in trehalose group and lactose group were 74.7% and 67.6%, while DNA integrity rates in trehalose group and lactose group were 66.4% and 63.2%, respectively. The common deformations of frozen sperms under SEM were partial or complete fracture between head and neck, swollen neck_ dama=ed aemsome stnJetn~.展开更多
A new compound 3-(2-(3,5-diphenyl-4,5-dihydropyrazol-1-yl)thiazol-4-yl)-2Hchromen-2-one was synthesized by cyclocondensation of 3,5-diphenyl-4,5-dihydropyrazole-1-carbothioamide with 3-(2-bromoacetyl)-2H-chromen...A new compound 3-(2-(3,5-diphenyl-4,5-dihydropyrazol-1-yl)thiazol-4-yl)-2Hchromen-2-one was synthesized by cyclocondensation of 3,5-diphenyl-4,5-dihydropyrazole-1-carbothioamide with 3-(2-bromoacetyl)-2H-chromen-2-one in ethanol at reflux for 2hrs. The compound was characterized by IR, 1H-NMR, 13C-NMR and single-crystal X-ray diffraction analysis. The newly synthesized compound(C27H19N3O2S) crystallizes in the triclinic system, space group P1 with a = 5.2476(6), b = 18.289(2), c = 23.115(3) , α = 93.546(7), β = 94.715(6), γ = 92.347(7)°, V = 2204.3(4)3, Z = 4, Mr = 449.51, crystal size = 0.38 mm × 0.22 mm × 0.16 mm,(I 2σ(I)) = 35317, 9736, 3785, Rint = 0.081,(Δρ)max = 0.19 and(Δρ)min = –0.24 e·-3. DNA interaction studies revealed that the target compound strongly interacts with DNA through an intercalation binding mode and the binding constant of the compound is 7.45 × 104 M-1.展开更多
The novel chromium(Ⅲ) complex with salicylaldehyde semicarbazone was synthesized and characterized by IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space ...The novel chromium(Ⅲ) complex with salicylaldehyde semicarbazone was synthesized and characterized by IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space group Pbca with a = 8.9849(13), b = 12.0475(16), c = 34.522(5)A, V = 3736.9(9)A3, Z = 8, C16H18C1CrN6O5, Mr= 461.81, De= 1.642 g/cm^3, F(000) = 1896,A(MoKα) = 0.799 mm^-1, the final R = 0.0370 and wR = 0.0827 for 2908 observed reflections with I 〉 2σ(I). The interaction between the chromium(Ⅲ) complex with calf thymus DNA (Ct-DNA) has been investigated by absorption spectroscopy, fluorescence spectroscopy and viscosity measurements. The results indicated that the complex was bonded to Ct-DNA through a non-classical intercalative mode.展开更多
The title compound α,α′-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopropenyl hydrazine (C16H22N6O, Mr = 314.40) has been prepared. It was characterized by elemental analysis as well as IR, MS, ^1H-NMR an...The title compound α,α′-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopropenyl hydrazine (C16H22N6O, Mr = 314.40) has been prepared. It was characterized by elemental analysis as well as IR, MS, ^1H-NMR and ^13C-NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction, getting the following data: triclinic, space group P1^- with a = 6.9734(16), b = 10.773(3), c = 12.001(3)A, α = 75.311(4), β = 82.695(4), ),γ = 77.143(4)°, Z = 2, V = 847.9(3)A^3, Dc = 1.231 g/cm^3, F(000) = 336 and/μ(MoKα) = 0.082 mm^-1 (λ= 0.71073A). The results of crystal structure determination show that there exist intermolecular and intramolecular hydrogen bonds, resulting in a two-dimensional supramolecular framework of the title compound. The binding of the title compound to DNA was investigated by absorption, emission, and viscosity measurements. The title compound shows absorption hyperchromicity accompanied by a blue shift at about 254 nm. The binding constant Kb for the title compound has been determined to be 1.89 × 10^4 M^-1 from absorption measurements. The addition of the title compound to DNA pretreated with EB causes appreciable reduction in the emission intensity, indicating that the DNA-bound EB fluorophore is partially replaced by the title compound. The value of K is 3.093 × 10^4 M^-1. The relative viscosity of DNA decreased with the addition of the title compound. Results suggest that the title compound binds to DNA with a non-classical intercalative or groove interaction mode. The observed efficient nuclease activity of the title compound is interesting and may have further influences on the chemistry of DNA minor groove binders.展开更多
A complex [Cd2Na2(BOABA)2(H2O)8]·H2O(1) was synthesized by using 2,4-bisoxyacetate-benzoic acid(H3BOABA) and Cd(OH)2. It was characterized by elemental analysis, IR spectra, and single-crystal X-ray dif...A complex [Cd2Na2(BOABA)2(H2O)8]·H2O(1) was synthesized by using 2,4-bisoxyacetate-benzoic acid(H3BOABA) and Cd(OH)2. It was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 shows a two-dimensional 3-connected rigid plane. The interactions between the ligand and its complex with DNA were studied by Et Br fluorescence probe. Photoluminescent studies indicate that the complex may be excellent candidates for potential photoactive materials.展开更多
An unsymmetrical macrocyclic dinuclear Zn(II) complex, [Zn2(H0.5L)(OAc)](ClO4)1.5(1, H2 L is the condensation product between 2, 6-diformyl-4-methylphenol and diethylenetriamine), was obtained and characteri...An unsymmetrical macrocyclic dinuclear Zn(II) complex, [Zn2(H0.5L)(OAc)](ClO4)1.5(1, H2 L is the condensation product between 2, 6-diformyl-4-methylphenol and diethylenetriamine), was obtained and characterized by IR spectrum, elemental analysis and X-ray single-crystal diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 16.784(2), b = 19.474(3), c = 10.3364(13)A, β = 92.923(2)°, V = 3374.1(7) A3, Z = 4, Dc = 1.672 g/cm^3, F(000) = 1740, μ = 1.651 mm^-1, the R = 0.0609 and wR = 0.1696 for 4745 observed reflections(I 〉 2σ(I)). The interactions of the complex with DNA have been measured by electrochemical studies, UV spectroscopy and viscosity experiment. The interactions of the complex with calf thymus DNA were studied by UV-vis spectra and the binding constant is 1.58 × 10^4 mol·L^-1. The phosphate hydrolysis catalyzed by the complex was investigated using 4-nitrophenyl phosphate(NPP) as the substrate; the observed first order rate constant value is 3.0 × 10^–4 s^-1.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12174051 and 12304069)。
文摘Valleytronics is an emergent discipline in condensed matter physics and offers a new way to encode and manipulate information based on the valley degree of freedom in materials. Among the various materials being studied, Kekulé distorted graphene has emerged as a promising material for valleytronics applications. Graphene can be artificially distorted to form the Kekulé structures rendering the valley-related interaction. In this work, we review the recent progress of research on Kekulé structures of graphene and focus on the modified electronic bands due to different Kekulé distortions as well as their effects on the transport properties of electrons. We systematically discuss how the valley-related interaction in the Kekulé structures was used to control and affect the valley transport including the valley generation, manipulation, and detection. This article summarizes the current challenges and prospects for further research on Kekulé distorted graphene and its potential applications in valleytronics.
基金supported by the National Natural Science Foundation of China (30800700)the China Agriculture Research System
文摘To understand genetic structure and diversity of parental cultivars involved in China Mainland sugarcane breeding programs, 92 elite parents and 4 wild relatives were genotyped with 18 microsatellite DNA markers. The genetic similarity (GS) values among the cultivars ranged from 0.346 to 0.960 with an average of 0.533. Among the introduced cultivars, India accessions had the closest genetic distance to China Mainland accessions (0.447), while Australia accessions have the furthest distance (0.503). A comparison of allelic diversity among geographical origins showed that there were 22 China Mainland specific alleles, of which 28% were derived from native S. spontaneaum germplasm in China. Model-based genetic structure, clustering, and principal components analyses consistently revealed there were five groups within the 96 accessions. Groups 1, 2, 4, and 5 consisted of all cultivars and group 3 only contained wild germplasm. Group 2 was characterized as the Introduction group with 46 cultivars predominantly introduced from Australia, Taiwan of China, India, and USA. Groups 1, 4, and 5 consisted of cultivars mostly originated from China Mainland, defined as the Complex group, Yacheng lines group, and F134/CP72-1210 group, respectively, upon their pedigree. By understanding the genetic relationships among the parental cultivars, breeders can gain a rational basis for expanding the gene pool and select the best parental accessions for crossing.
文摘The absorption, fluorescence and Raman spectra of Ce(NO3)(3)(phen)(2) complex were assigned and the crystal structure of the complex was studied. Meanwhile the interactions between Cc (NO3)(3) (phen)(2) and DNA were studied by spectrum methods. As DNA was added, it is found that both the UV absorption bands of Ce(NO3)(3)(phen)(2) and the SERS bands of Ce(NO3)(3)(phen)(2) weaken evidently, while the fluorescence intensity of Ce(NO3)(3)(phen)(2) enhance dramatically. The complex compete against EB on the reaction with DNA. It is indicated by this spectrum methods that there are strong interactions between Ce(NO3)(3)(phen)(2) and DNA, and the bond mode is intercalation. The bond constant of the complex with DNA is determined to be 1.7 x 10(5).
基金supported by the National Natural Science Foundation of China(No.21002076)Wuhan Youth Chenguang Program of Science and Technology(No.201271031374)
文摘The novel dinuclear copper complex [Cu2(H20)2(DMF)2(L)2] (1, H2L = 5-phenyl- 2H-1,2,3-triazole-4-carboxylic acid, DMF = N,N-dimethyl-formamide) has been synthesized and characterized by X-ray single-crystal diffraction. The compound crystallizes in triclinic system, space group P1 with a = 9.591, b = 10.508, c = 15.515A,β = 75.11°, V= 1446.2 A3, Z= 2, Mr = 683.62, Dc = 1.570 g/cm3, μ = 1.531 mm^-1, F(000) = 700, the final R = 0.0404 and wR = 0.1130 for 5327 observed reflections with I 〉 2σ(I). In each unit of the complex, two Cu2+ ions coordinated with two triazole ligands to form a dimeric [5,6,5] tricyclic structure. The central Cu atom is five-coordinated, and each copper atom shows a square pyramidal geometry. The crystal structure is stabilized by the inversion-related O-H…O hydrogen bond and C-H…O hydrogen bonding interactions to form a layer structure. Fluorescent spectra show an obvious quenching of fluorescence compared with free 1,2,3-triazole ligand. The results of agarose gel electrophoresis indicate that this complex can cleave the plasmid supercoiled DNA within shorter time in the 50-folds excess of ascorbate under physiological conditions, providing a new example in the research for artificial metal nucleic acid enzyme.
基金Supported by the Scientific Research Foundation of Higher Education Institutions of Ningxia(No.NGY2017004)the National Natural Science Foundation of China(Nos.21763022 and 50564043)the Major Innovation Projects for Building First-class Universities in China’s Western Region(No.ZKZD2017003)
文摘A new complex Mn(Htpc)2(H2O)2(1, Htpc = 5-(trifluoromethyl)pyridine-2-carboxylic acid) has been synthesized and characterized by elemental analysis, IR, TG and single-crystal X-ray diffraction. 1 belongs to triclinic system, space group P■ with a = 5.0885(10), b = 6.5574(13), c = 14.016(3) ?, β = 90.67(3)o, V = 436.34(17) ?3, Z = 1, Dc = 1.793 g·cm-3, μ = 0.855 mm-1, Mr = 471.18, F(000) = 235, the final R = 0.0454 and wR = 0.1134 for 1998 observed reflections with I > 2σ(I). The Mn(Ⅱ) ion is coordinated by two N and two O atoms from two Htpc as well as two O atoms from two coordinated water molecules, forming a 0D motif with distorted octahedral coordinate geometry. The adjacent 0D units are linked into 1D chains through hydrogen bond O(1W)–H(1 WB)···O(2), and via the O(1 W)–H(1 WA)···O(1) hydrogen bond the neighboring 1D chains are connected into a 2D supramolecular layer. Moreover, the interactions between the ligand and its complex with CT-DNA were studied by EtBr fluorescence probe, which suggested that these compounds bind to CT-DNA through an intercalation mode. The binding constants were 0.41 and 0.64 for Htpc and complex 1, respectively. It indicates that the interaction between complex 1 and CT-DNA is stronger than Htpc.
基金Supported by the Foundation for Jilin of China of 2014 Human Resources Developmentthe Natural Science Project Foundation of Education Department of Jilin Province(No.2015358)the Natural Science Foundation of Changchun Normal University(No.201203)
文摘Zn(Ⅱ), Ni(Ⅱ) and Co(Ⅱ) compounds(1~3) based on 2-(2-pyridyl)benzothiazole(bpt) and terephthalic acid(PTA) were synthesized. The crystal structures of [Zn(bpt)(PTA)2](1), [Ni(bpt)(PTA)2](2), and [Co(bpt)(PTA)2](3) have been determined by single-crystal X-ray diffraction analysis, which shows that all the three complexes belong to monoclinic system with space group P21/c. Time-dependent density functional theory(TD-DFT) calculation is performed on a reference structure of compound 3. The excited electrons mainly localized at the π* of ligand 2-(2-pyridyl)benzothiazole, which will be convenient for them to bind with the DNA reacting sites. Fluorescence spectroscopy, ultraviolet(UV) spectroscopy and viscosity were used to characterize the interaction of the compounds with Calf thymus DNA(CT-DNA). The results indicate that compounds 1~3 bind to CT-DNA and have a strong interaction with DNA. The compounds can probably bind to CT-DNA via a non-intercalative mode as concluded by studying the viscosity of a DNA solution in the presence of the compounds. This combination can effectively break DNA, which speculates that these three compounds may interact with the cancer cell DNA in this binding mode, thereby damaging the cancer cells.
基金supported by the Natural Science Foundation of Zhejiang Province (Y407301)
文摘The title compound, N-(benzimidazol-2-ylmethyl)-5-chlorosalicylideneimine, has been synthesized and characterized by X-ray single-crystal diffraction. It crystallizes in the monoclinic system, space group P21/n, with a = 8.3765(2), b = 18.1398(4), c = 9.4764(3)А, β= 112.141(2)°, V= 1333.74(6)А^3, Mr = 285.73, Z = 4, Dc = 1.423 g/cm^3, F(000) = 592,/z = 0.285 mm^-1, the final R = 0.0538 and wR = 0.1456 for 1917 observed reflections with I〉2σ-(I). The fluorescence quenching of the title compound by DNA with Stern-Volmer constant of 2.8×104 M^-1 indicates that it binds to double-stranded DNA in a partial intercalation mode.
文摘A new asymmetric bidentate copper(Ⅱ) complex,CuL 2(HL=2-((E)-(4-bromophenylimino)methyl)-6-bromo-4-chlorophenol),has been synthesized and characterized by elemental analyses and single-crystal X-ray diffraction.The complex crystallizes in the monoclinic space group P2 1 /c with a=11.218(3),b=9.355(3),c=13.449(4),β=108.722(4)°,V=1336.8(6)3,Z=2,Dc=2.008 g/cm 3,μ(MoKα)=7.024 mm-1,F(000)=806,S=0.999,the final R=0.0342 and wR=0.0641for2611observed reflections (I〉2σ(I)).The central copper(Ⅱ) is four-coordinate and bonds to two nitrogen and two oxygen atoms from two Schiff base ligands.The complex is linked into a two-dimensional supramolecular structure by weak intermolecular interactions.In addition,DNA-binding properties of the metal complex were investigated using spectrometric titrations and viscosity measurements.The results show that the complex binds with calf-thymus DNA(CT-DNA),presumably via a partial intercalative mode.The intrinsic binding constant of the Cu(Ⅱ) complex with DNA is 7.335×10 3 M-1.
基金supported by the Public Science and Technology Research Funds Projects of Ocean (Nos. 201305043 and 201405010)
文摘In this study, the entire mitochondrial DNA(mtDNA) control region(CR) of Pholis fangi was amplified via polymerase chain reaction followed by direct sequencing. The length of the mtDNA CR consensus sequence of P. fangi was 853 bp in length. In accordance with the recognition sites as were previously reported in fish species, the mtDNA CR sequence of P. fangi can be divided into 3 domains, i.e., the extended terminal associated sequence(ETAS), the central conserved sequence block(CSB), and the CSB domain. In addition, the following structures were identified in the mtDNA CR sequence of P. fangi: 2 ETASs in the ETAS domain(TAS and cTAS), 6 CSBs in the central CSB domain(CSB-F to CSB-A), and 3 CSBs in the CSB domain(CSB-1 to CSB-3). These demonstrated that the structure of the mtDNA CR of P. fangi was substantially different from those of most other fish species. The mtDNA CR sequence of P. fangi contained one conserved region from 656 bp to 815 bp. Similar to most other fish species, P. fangi has no tandem repeat sequences in its mtDNA CR sequence. Phylogenetic analysis based on the complete mtDNA CR sequences showed that there were no genetic differences within P. fangi populations of the same geographical origin and between P. fangi populations of different geographical origins.
基金supported by the National Natural Science Foundation of China (No. 41776171)
文摘Pholis fangi is an ecologically important fish species inhabiting Chinese coastal waters of Yellow Sea and Bohai Sea. To investigate the genetic diversity and population genetic structure of P. fangi, a fragment of 487 bp in the first hypervariable region (HVR-1) of the mitochondrial DNA (mtDNA) control region was sequenced for 181 individuals collected from Bohai Sea and Yel- low Sea. A total of 18 polymorphic sites were detected, which defined 25 haplotypes. A moderate level of haplotype diversity (h = 0.7052) and a low level of nucleotide diversity (π= 0.0028) were detected. Both the phylogenetic tree and the haplotype network showed no significant genealogical structure difference among sampling locations. Pairwise FST comparison and hierarchical mo- lecular variance analysis (AMOVA) revealed that no significant genetic structure difference existed throughout the investigated re- gions, suggesting a high gene exchange among different populations. The results of neutrality test and mismatch distribution analysis indicated that a late Pleistocene population expansion (38000 127000 years ago) happened. Seasonal schooling migration may con- tribute to the genetically homogeneous population structure of the species.
文摘The title complex [ NH3 CH2 CH ( NH2 ) CH3 ]2 [ M ( Ⅵ ) O2 ( OC6 H4 O)2 ] ( M = Mo0. 6 W0.4 ) was synthesized via a simple solution-phase ehemieal route. The determination of single erystal X-ray diffraction revealed that the title eompound is erystallized in a monoelinie system with P2( 1 )/n spaee group, a = 1. 0913(10) nm, b = 1. 0442(10) nm, c=1.8842(19) nm, α=90°, β=96.530(17)°, γ=90°, Z=4, and V=2.133(4) nm^3. The mononuelear anionie unit [ M ( Ⅵ ) O2 ( 0C6 H4 O) 2 ] 2 - displays ehiral pseudo-oetahedral [ MO6 ] eoordination geometry and is linked by ehiral eations via hydrogen bond and π…π stacking interaetion. The transmission electron microseopy images show that the title eomplex is eomprised of nano-partieles with diameters ranging from 20 to 50 nm. The NMR study shows the ^1H downfield chemical shifts of [ NH3 CHa Hb CH ( NH2 ) CH3 ]^+ eations in the title eomplex when it is mixed with adenosine-triphosphate( ATP), and the chemical shift difference between Ha and Hb is inereased greatly, and most of the eateeholate ligands dissociate from the eentral metal atoms. The DNA cleavage aetivity experiment reveals that DNA eleavage promoted by the title eomplex is lower than that by Na2 MoO4 whieh possesses antitumor propetty, but higher than that by Na2WO4.
基金supported by the Natural Science Foundation of Hunan Province (No. 13JJ3112)Scientific & Technological Projects of Hunan Province (No. 2013TZ2025, 2014FJ3060)+2 种基金Scientific Research Fund of Hunan Provincial Education Department of China (14C0171)the Foundation of Key Laboratory of Functional Organometallic Materials,University of Hunan Province(No. 13K03, 13K04, 13K05)the Science Foundation of Hengyang Normal University (No. 12C45, 13A21)
文摘The Schiff base organotin(IV) complex {[4-Et2NC6H3(O)C=NC6H3(O)-5-NO2](n- Bu2Sn)}2 has been synthesized via the reaction between 4-(diethylamino) salicylaldehyde-2-arnino- 4-nitrophenol Schiff base (H2L) and dibutyltin oxide. Complex C1 has been characterized by IR, 1H NMR, 13C NMR spectra, and elemental analysis, and its crystal structure was determined by X-ray diffraction, It crystallizes in the monoclinic system, space group P21/n with a = 15.6559(8), b = 9.1657(5), c = 18.8351(10) ]A, β = 107.3440(10)°, Z = 4, V = 2579.9(2) A3, Dc = 1.442 Mg.m-3, μ(MoKa) = 1.025 mm-1, F(000) = 1152, R = 0.0250 and wR = 0.0633. The central Sn atom is coordinated in a hexadentate manner to assume a distorted octahedral configuration. Complex C1 was studied by TGA analysis in air atmosphere. The interaction between complex C1 and the herring sperm DNA was realized through the intercalation of the complex based on the studies by EB fluorescent probe.
基金Project was supported by the Natural Science Foundation of China (20671064), Natural Science Foundation of Liaoning Province (20052014) and the Ph. D. Programs Foundation of China
文摘A new complex [Ni(phen)(mal)(H2O)2]·3H2O (phen = 1,10-phenanthroline, real^2- = malonic acid) has been synthesized by the reaction of nickel nitrate, phen and malonic acid. EA, IR spectra and X-ray single-crystal diffraction were carried out to determine the composition and crystal structure of the title complex. Crystal data: monoclinic system, space group P2/c,α = 8.937(3), b = 12.163(5), c = 9.725(3) A,β = 119.36°, C15H19N2O9Ni,Mr= 430.03, Z = 2, F(000) = 446, V= 921.3 A3, Dc = 1.550 g/cm^3, μ= 1.104 mm^-1, -10≤h≤10, -12≤k≤ 14, -11≤1≤7, R = 0.0261 and wR = 0.0609 for 4376 (Rint = 0.0203) independent reflections and 1631 observed ones (I 〉 2σ(I)). Ni(Ⅱ) exhibits an octahedral coordination geometry, with hydrogen bonds and π-π interactions stabilizing the whole structure. UV spectrum of the complex interacting with protamine DNA indicates that the title compound interacts with DNA via insertion mode with bonding constant Kb of 1. 11 × 10^4.
基金Supported by Natural Science Foundation of Jiangsu Province(BK2008589)
文摘The paper was to explore the effect of cryopreservation on DNA integrity and morphological structure of boar sperm, and to explore the protective effect of trehalose and lactose on frozen boar sperm. The morphology, ultrastructure and DNA integrity of sperms were observed by phase contract microscope, scanning electron microscope (SEM) and acridine orange (AO) staining, respectively. The results showed that the normal morphological rate and DNA integrity rate of fro- zen sperms were significantly lower than that of fresh sperms (95.5% and 94.7%, respectively), and the difference between two frozen groups was also significant (P 〈 0.05 ). The normal morphological rates in trehalose group and lactose group were 74.7% and 67.6%, while DNA integrity rates in trehalose group and lactose group were 66.4% and 63.2%, respectively. The common deformations of frozen sperms under SEM were partial or complete fracture between head and neck, swollen neck_ dama=ed aemsome stnJetn~.
基金supported by the Higher Education Commission(HEC),Govt.of Pakistan
文摘A new compound 3-(2-(3,5-diphenyl-4,5-dihydropyrazol-1-yl)thiazol-4-yl)-2Hchromen-2-one was synthesized by cyclocondensation of 3,5-diphenyl-4,5-dihydropyrazole-1-carbothioamide with 3-(2-bromoacetyl)-2H-chromen-2-one in ethanol at reflux for 2hrs. The compound was characterized by IR, 1H-NMR, 13C-NMR and single-crystal X-ray diffraction analysis. The newly synthesized compound(C27H19N3O2S) crystallizes in the triclinic system, space group P1 with a = 5.2476(6), b = 18.289(2), c = 23.115(3) , α = 93.546(7), β = 94.715(6), γ = 92.347(7)°, V = 2204.3(4)3, Z = 4, Mr = 449.51, crystal size = 0.38 mm × 0.22 mm × 0.16 mm,(I 2σ(I)) = 35317, 9736, 3785, Rint = 0.081,(Δρ)max = 0.19 and(Δρ)min = –0.24 e·-3. DNA interaction studies revealed that the target compound strongly interacts with DNA through an intercalation binding mode and the binding constant of the compound is 7.45 × 104 M-1.
基金Supported by the Scientific Research Common Program of Beijing Municipal Commission of Education, PRC (KM200510028005)
文摘The novel chromium(Ⅲ) complex with salicylaldehyde semicarbazone was synthesized and characterized by IR spectra and single-crystal X-ray diffraction analysis. The crystal belongs to the orthorhombic system, space group Pbca with a = 8.9849(13), b = 12.0475(16), c = 34.522(5)A, V = 3736.9(9)A3, Z = 8, C16H18C1CrN6O5, Mr= 461.81, De= 1.642 g/cm^3, F(000) = 1896,A(MoKα) = 0.799 mm^-1, the final R = 0.0370 and wR = 0.0827 for 2908 observed reflections with I 〉 2σ(I). The interaction between the chromium(Ⅲ) complex with calf thymus DNA (Ct-DNA) has been investigated by absorption spectroscopy, fluorescence spectroscopy and viscosity measurements. The results indicated that the complex was bonded to Ct-DNA through a non-classical intercalative mode.
基金financially supported by young science found of Key Laboratory of Advanced Textile Materials and Manufacturing Technology (Zhejiang Sci-Tech University), Ministry of Education
文摘The title compound α,α′-bis(3,5-bismethyl-pyrozole-N-yl)-carbene-acetyl-isopropenyl hydrazine (C16H22N6O, Mr = 314.40) has been prepared. It was characterized by elemental analysis as well as IR, MS, ^1H-NMR and ^13C-NMR spectra. Its crystal structure was determined by single-crystal X-ray diffraction, getting the following data: triclinic, space group P1^- with a = 6.9734(16), b = 10.773(3), c = 12.001(3)A, α = 75.311(4), β = 82.695(4), ),γ = 77.143(4)°, Z = 2, V = 847.9(3)A^3, Dc = 1.231 g/cm^3, F(000) = 336 and/μ(MoKα) = 0.082 mm^-1 (λ= 0.71073A). The results of crystal structure determination show that there exist intermolecular and intramolecular hydrogen bonds, resulting in a two-dimensional supramolecular framework of the title compound. The binding of the title compound to DNA was investigated by absorption, emission, and viscosity measurements. The title compound shows absorption hyperchromicity accompanied by a blue shift at about 254 nm. The binding constant Kb for the title compound has been determined to be 1.89 × 10^4 M^-1 from absorption measurements. The addition of the title compound to DNA pretreated with EB causes appreciable reduction in the emission intensity, indicating that the DNA-bound EB fluorophore is partially replaced by the title compound. The value of K is 3.093 × 10^4 M^-1. The relative viscosity of DNA decreased with the addition of the title compound. Results suggest that the title compound binds to DNA with a non-classical intercalative or groove interaction mode. The observed efficient nuclease activity of the title compound is interesting and may have further influences on the chemistry of DNA minor groove binders.
基金supported by the Natural Science Project of Zhejiang Province(LY12B01003)
文摘A complex [Cd2Na2(BOABA)2(H2O)8]·H2O(1) was synthesized by using 2,4-bisoxyacetate-benzoic acid(H3BOABA) and Cd(OH)2. It was characterized by elemental analysis, IR spectra, and single-crystal X-ray diffraction. Complex 1 shows a two-dimensional 3-connected rigid plane. The interactions between the ligand and its complex with DNA were studied by Et Br fluorescence probe. Photoluminescent studies indicate that the complex may be excellent candidates for potential photoactive materials.
基金Supported by National Natural Science Foundation of China(21201136)Wuhan Youth Chenguang Program of Science and Technology(201271031374)
文摘An unsymmetrical macrocyclic dinuclear Zn(II) complex, [Zn2(H0.5L)(OAc)](ClO4)1.5(1, H2 L is the condensation product between 2, 6-diformyl-4-methylphenol and diethylenetriamine), was obtained and characterized by IR spectrum, elemental analysis and X-ray single-crystal diffraction. The complex crystallizes in monoclinic, space group P21/c with a = 16.784(2), b = 19.474(3), c = 10.3364(13)A, β = 92.923(2)°, V = 3374.1(7) A3, Z = 4, Dc = 1.672 g/cm^3, F(000) = 1740, μ = 1.651 mm^-1, the R = 0.0609 and wR = 0.1696 for 4745 observed reflections(I 〉 2σ(I)). The interactions of the complex with DNA have been measured by electrochemical studies, UV spectroscopy and viscosity experiment. The interactions of the complex with calf thymus DNA were studied by UV-vis spectra and the binding constant is 1.58 × 10^4 mol·L^-1. The phosphate hydrolysis catalyzed by the complex was investigated using 4-nitrophenyl phosphate(NPP) as the substrate; the observed first order rate constant value is 3.0 × 10^–4 s^-1.