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1.
The crystal-face dependence of the dye-sensitized photocurrents and the adsorption properties of benzothiazole merocyanine (Mc[18,1]) dye molecules were investigated, using atomically flat (1 0 0) and (1 1 0) TiO2 single crystal surfaces. From the estimation of the amount of the transferred charge from the TiO2 surface to CO groups of dye molecules based on NEXAFS data, it was revealed that the interaction of the adsorbed molecules and the (1 1 0) surface was much stronger than that for the (1 0 0) surface. On the other hand, the absorbed photon to current conversion efficiency (APCE) value was almost the same for both surfaces. We suggested a possible explanation as follows: the energy difference between the LUMO of Mc[18,1] and the conduction band of TiO2 was large enough to give a nearly 100% quantum efficiency of electron transfer from photoexcited dye to TiO2, which made the difference in the interaction between dye molecules and TiO2 not apparent. The incident photon to current conversion efficiency (IPCE) for the (1 0 0) surface was much larger than that for the (1 1 0) surface, which was explained by the fact that the amount of the adsorbed dye molecules on the (1 0 0) surface was larger than on the (1 1 0) surface, probably due to the larger surface density of five-coordinated Ti sites in the former surface.  相似文献   

2.

Aim

To investigate the association between interleukin-6 (IL-6) − 174G > C and − 572C > G polymorphisms and risk for ischemic stroke (IS) in young patients.

Methods

We genotyped IL-6  − 174G > C and − 572C > G in a case–control study of 430 young IS patients and 461 control subjects. An unconditional multiple logistical regression model was used to calculate the effects of IL-6 − 174G > C and − 572C > G polymorphisms on IS risk.

Results

Higher body mass index, diabetes, hypertension, obesity, and smoking were associated with risk of ischemic stroke. Multivariate regression analyses showed that subjects carrying the − 174CC genotype (OR = 1.69, 95% CI = 1.16–2.57) and C allele (OR = 1.37, 95% CI = 1.09–1.67) had a small but significant increased risk of IS. Similarly, those carrying the − 572GG genotype (OR = 2.12, 95% CI = 1.18–3.82) and G allele (OR = 1.43, 95% CI = 1.14–1.83) had a moderate increased risk of IS. We found the − 174G > C and − 572C > G polymorphisms interact with hypertension and obesity.

Conclusion

Our results suggest that polymorphisms in IL-6 − 174G > C and − 572C > G are associated with IS risk in young patients, and that these polymorphisms interact with hypertension, obesity and etiologic subtypes. These findings could be helpful in identifying individuals at increased risk for developing IS.  相似文献   

3.
The hydrothermal reactions of MoO3, tetra-2-pyridylpyrazine (tpyprz) and M(CH3CO2)2 · 2H2O (M = Co, Ni) yielded the two-dimensional oxides [M2(tpyprz)(H2O)2Mo8O26] · xH2O [M = Co, x = 1.8 (1); M = Ni, x = 0.6 (2)]. However, the reaction of (NH4)6Mo7O24 · 4H2O, tpyprz and Cu(CH3CO2)2 · H2O produced [{Cu2(tpyprz)}2Mo8O26] · 2H2O (3 · 2H2O). The isomorphous structures of 1 and 2 are constructed from clusters linked through {M2(tpyprz)(H2O)2}4+ subunits into two-dimensional networks. While the structure of 3 is also two-dimensional, the molybdate building block is present as the δ-isomer and the secondary-metal/ligand component consists of a one-dimensional chain. The structure of 3 is compared to that of the previously reported three-dimensional material [{Cu2(tpyprz)}2Mo8O26] · 7H2O which contains clusters and structurally distinct chains.  相似文献   

4.
Low-temperature, single crystal X-ray structural characterisations of trans-[NiCl2(HOMe)4], trans-O-[Ni(MeOH)2(μ-Cl)(2/2)2](∞∣∞) · 0.5dioxan and trans-trans-[Ni(H2O)2Cl2(O-dioxan-O)(2/2)](∞∣∞) · dioxan are recorded, offering intriguing insights into O-donor/Ni(II) relativities. All nickel atoms in all structures are located on crystallographic inversion centres, the last two compounds being one-dimensional polymers.  相似文献   

5.
Phosphoryl-transfer reactions have long been of interest due to their importance in maintaining numerous cellular functions. A phosphoryl-transfer reaction results in two possible stereochemical outcomes: either retention or inversion of configuration at the transferred phosphorus atom. When the product is phosphate, isotopically-labeled [16O, 17O, 18O]-phosphate derivatives can be used to distinguish these outcomes; one oxygen must be replaced by sulfur or esterified to achieve isotopic chirality. Conventionally, stereochemical analysis of isotopically chiral phosphate has been based on 31P NMR spectroscopy and involves complex chemical or enzymatic transformations. An attractive alternative would be direct determination of the enantiomeric excess using chiroptical spectroscopy. (S)-Methyl-[16O, 17O, 18O]-phosphate (MePi), 7 and enantiomeric [16O, 17O, 18O]-thiophosphate (TPi), 10, were previously reported to exhibit weak electronic circular dichroism (ECD), although with 10 the result was considered to be uncertain. We have now re-examined the possibility that excesses of 7 and 10 enantiomers can be detected by ECD spectrometry, using both experimental and theoretical approaches. 7 and both the (R) and (S) enantiomers of 10 (10a10b) were synthesized by the ‘Oxford route’ and characterized by 1H, 31P and 17O NMR, and by MS analysis. Weak ECD could be found for 7, with suboptimal S/N. No significant ECD could be detected for the 10 enantiomers.Time-dependent DFT (TDDFT) calculations of the electronic excitation energies and rotational strengths of the same three enantiomers were carried out using the functional B3LYP and the basis set 6-311G∗∗. The isotopically-perturbed geometries were predicted using the anharmonic vibrational frequency calculational code in GAUSSIAN 03. In the case of 10, calculations were also carried out for the hexahydrated complex to investigate the influence of the aqueous solvent. The predicted excitation wavelengths are greater than the observed wavelengths, a not unusual result of TDDFT calculations. The predicted anisotropy ratios are 2.9 × 10−5 for 7, −5.3 × 10−6 for 10a/b, and 1.7 × 10−6 for 10a/b⋅(H2O)6. For 7 the predicted anisotropy ratio approximates that observed in this work, 4.5 × 10−5 at 208 nm. For 10a/b, the upper limits of the experimental anisotropy ratios (<5 × 10−6 at 225 nm, pH 9; <5 × 10−6 at 236 nm, pH 12) are comparable to the predicted magnitude of the value for 10a/b. The lower predicted value for 10a/b · (H2O)6 suggests that the aqueous environment affects the ECD significantly. Altogether, the TDDFT calculations together with a stereochemical analysis based on NMR and the MS data support the conclusion that the experimental ECD results for MePi and TPi may be reliable in order of magnitude.  相似文献   

6.
Reaction of [CuIIL⊂(H2O)] (H2L = N,N′-ethylenebis(3-ethoxysalicylaldimine)) with nickel(II) perchlorate in 1:1 ratio in acetone produces the trinuclear compound [(CuIIL)2NiII(H2O)2](ClO4)2 (1). On the other hand, on changing the solvent from acetone to methanol, reaction of the same reactants in same ratio produces the pentametallic compound [(CuIIL)2NiII(H2O)2](ClO4)2·2[CuIIL⊂(H2O)]·2MeOH (2A), which loses solvated methanol molecules immediately after its isolation to form [(CuIIL)2NiII(H2O)2](ClO4)2·2[CuIIL⊂(H2O)] (2B). Clearly, formation of 1 versus 2A and 2B is solvent dependent. Crystal structures of 1 and 2A have been determined. Interestingly, compound 2A is a [3 × 1 + 1 × 2] cocrystal. The cryomagnetic profiles of 1 and 2B indicate that the two pairs of copper(II)···nickel(II) ions in the trinuclear cores in both the complexes are coupled by almost identical moderate antiferromagnetic interaction (J = −22.8 cm−1 for 1 and −26.0 cm−1 for 2B).  相似文献   

7.
The iridium 1,1,1-tris(diphenylphosphinomethyl)ethane (triphos) complexes [{κ2(C1,C4)-CRCRCRCR}{CH3C(CH2PPh2)3}Ir(NCMe)]BF4 (2-NCMe, R = CO2Me) and [{κ2(C1,C4)-CRCRCRCR}{CH3C(CH2PPh2)3}Ir(CO)]BF4 (2-CO, R = CO2Me) serve as models for proposed iridium-vinylidene intermediates of relevance to the [2 + 2 + 1] cyclotrimerization of alkynes. The solid-state structures of 2-NCMe, 2-CO, and [κ2(C1,C4)-CRCRCRCR]{CH3C(CH2PPh2)3}Ir(Cl) (2-Cl), were determined by X-ray crystallography.  相似文献   

8.

Background

Diethylnitrosamine (DEN) and carbon tetrachloride (CCl4) have been used as initiator and promoter respectively to establish an animal model for investigating molecular events appear to be involved in development of liver cancer. Use of herbal medicine in therapeutics to avoid the recurrence of hepatocarcinoma has already generated considerable interest among oncologists. In this context studies involving S-allyl-cysteine (SAC) and berberine have come up with promising results. Here we have determined the individual effect of SAC and berberine on the biomolecules associated with DEN + CCl4 induced hepatocarcinoma. Effective therapeutic value of combined treatment has also been estimated.

Methods

ROS accumulation was analyzed by FACS following DCFDA incubation. Bcl2-Bax and HDAC1‐pMdm2 interaction were demonstrated by co-immunoprecipitation. Immunosorbent assay was performed to analyze PP2A and caspase3 activities. MMP was determined cytofluorimetrically by investigating JC-1 fluorescence. AnnexinV binding was demonstrated by labeling the cells with AnV-FITC followed by flow cytometry.

Results

CytochromeP4502E1 mediated bioactivation of DEN + CCl4 induced Akt dependent pMdm2‐HDAC1 interaction that led to p53 deacetylation, probable cause of its degradation. In parallel, oxidative stress dependent Nrf2‐HO1 activation increased Bcl2 expression which in turn stimulated cell proliferation. SAC in combination with berberine inhibited Akt mediated cell proliferation. Activation of PP2A as well as inhibition of JNK resulted in induction of apoptosis after 30 days of treatment. Extension of combined treatment reverted tissue physiology towards control. Co-treated group displayed normal tissue structure.

Conclusion and general significance

SAC and berberine mediated HDAC1/Akt inhibition implicates the efficacy of combined treatment in the amelioration of DEN + CCl4 induced hepatocarcinoma.  相似文献   

9.

Background

The human adiponectin gene variations are associated with obesity, insulin resistance, and diabetes. However, these associations have not been fully examined in a non-diabetic population in Saudi Arabia. We aimed to investigate the association of 45T > G single nucleotide polymorphism (SNP) in the adiponectin gene with total adiponectin levels, insulin resistance (IR), fasting blood glucose (FBG) and other markers of obesity in non-diabetic Saudi females.

Methods

One hundred non diabetic Saudi females were enrolled in this study. They were further divided according to their body mass index (BMI) into two groups. Group I, 46 non diabetic subjects with normal body weight and group II, 54 overweight and obese females. Adiponectin 45T/G polymorphism was detected by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP). Serum adiponectin was measured by ELISA.

Results

Obese women exhibited a higher distribution of TG/GG genotype compared with non-obese women. SNP + 45T > G genotypes were associated with higher FBG, insulin levels and HOMA–IR with lower total adiponectin levels in obese Saudi women. Otherwise the all estimated variables revealed non-significant differences among the non-obese genotypes. The observed differences in insulin resistance markers were very significant among women with a higher body weight but not among normal body weight women, thus suggesting that SNP + 45T > G effects on insulin sensitivity may depend upon body weight and body fat status.

Conclusion

SNP + 45T > G of adiponectin gene has a significant role in the development of insulin resistance in Saudi women possibly through an interaction with increase body weight and hypoadiponectinemia.  相似文献   

10.
The reaction of [RuCl2(PPh3)3] and [OsBr2(PPh3)3] precursors with a series of heterocyclic bidentate (N, X) ligands, X = S, Se, gave complexes [M(R-pyS)2(PPh3)2], (R = H, 3-CF3, 5-CF3, 3-Me3Si); [M(R-pymS)2(PPh3)2], (R = 4-CF3, 4,6-MeCF3) and [M(R-pySe)2(PPh3)2], (R = H, 3-CF3, 5-CF3), where M is Ru or Os, pyS and pymS the anions of pyridine-2-thione and pyrimidine-2-thione, respectively, and pySe is the anion produced by the reductive cleavage of the Se-Se bond in the dipyridyl-2,2′-diselenide. All of the compounds obtained were characterized by microanalysis, IR, FAB, NMR spectroscopy and by cyclic voltammetry. Compounds [Ru(3-CF3-pyS)2(PPh3)2] · 2(CH2Cl2) (2), [Ru(3-Me3Si-pyS)2(PPh3)2] (4), [Ru(4-CF3-pymS)2(PPh3)2] (5), [Ru(3-CF3-pySe)2(PPh3)2] · 2(CH2Cl2) (8), [Os(3-CF3-pyS)2(PPh3)2] · (CHCl3) (11), [Os(3-Me3Si-pyS)2(PPh3)2] (13), [Os(3-CF3-pySe)2(PPh3)2] · 2(CH2Cl2) (17), [Os(5-CF3-pySe)2(PPh3)2] · 2(H2O) (18) and [OsCl2(4,6-MeCF3-pymS)(PPh3)2] (19) were also characterized by X-ray diffraction. In all cases, the metal is in a distorted octahedral environment with the heterocyclic ligand acting as a bidentate (N, S) chelate system.  相似文献   

11.
The reactions of methyl 2-pyridyl ketone oxime, (py)C(Me)NOH, with MSO4 · xH2O (M = Zn, x = 7; M = Cd, x = 8/3), in the absence of an external base, have been investigated. The synthetic study has led to the two new complexes [Zn(SO4){(py)C(Me)NOH}(H2O)3] · H2O (1 · H2O) and [Zn2(SO4)2{(py)C(Me)NOH}4] · (py)C(Me)NOH [2 · (py)C(Me)NOH], and the coordination polymer [Cd(SO4){(py)C(Me)NOH}(H2O)]n · [Cd(SO4){(py)C(Me)NOH}(H2O)2]n (3). In the three complexes the organic ligand chelates through its nitrogen atoms. The sulfate anion in 1 · H2O is monodentate; the complex molecule is the mer isomer considering the positions of the aqua ligands. The ZnII centers in 2 · (py)C(Me)NOH are bridged by two syn, anti η112 ligands; each metal ion has the cis-cis-trans disposition of the coordinated sulfate oxygen, pyridyl nitrogen and oxime nitrogens, respectively. The molecular structure of 3 is unique consisting of two different linear and ladder - type chains. π-π stacking interactions and/or hydrogen bonds lead to the formation of interesting supramolecular architectures in the three complexes. The thermal decomposition of complex 3 has been studied. Characteristic vibrational (IR, Raman) bands are discussed in terms of the nature of bonding and the structures of the three complexes.  相似文献   

12.
A synthetic strategy for the covalent anchoring of nickel β-diketonate complexes on Si(1 0 0) has been examined. Engineered Si(1 0 0) surfaces were prepared by the Si-grafting of 10-undecylenic acid methyl ester followed by hydrolysis of the ester to free the carboxylic functions suited for the anchoring of the Ni complex. Bis(pentane-2,4-dionate)Ni(II) was bonded to the functionalized surface from the gas phase by the exchange of the acetylacetonate ligand with the grafted acid. The surface density of the anchored Ni complex was controlled by tuning the surface concentration of carboxylic groups adopting a mixed monolayer of undecylenic acid and 1-decene used as a spectator spacer. The nickel decorated silicon surfaces were characterized by attenuate total reflectance infrared absorption spectroscopy (ATR-IRAS) and angle resolved X-ray photoelectron spectroscopy (AR-XPS).  相似文献   

13.
Aneuploid cells are frequently observed in human tumors, suggesting that aneuploidy may play an important role in the development of cancer. In this review, I discuss the processes that may give rise to aneuploid cells in normal tissue and in tumors. Aneuploid cells may arise directly from diploid cells through errors in chromosome segregation, as a consequence of incorrect microtubule-kinetochore attachments, or through failure of the spindle checkpoint. A second route to formation of aneuploid cells is through a tetraploid intermediate, where division of tetraploid cells can yield very high rates of chromosome missegregation as a consequence of multipolar spindle formation. Diploid cells may become tetraploid through a variety of mechanisms, including endoreduplication, cell fusion, and cytokinesis failure. Although aneuploid cells may arise from either diploid or tetraploid cells, the fate of the resulting aneuploid cells may be distinct. It is therefore important to understand the different pathways that can give rise to aneuploid cells, and how the varied origins of these cells affect their subsequent ability to survive or proliferate.  相似文献   

14.
Single-crystal X-ray structural characterizations of MX:dpam (1:1) (‘dpam’ = Ph2AsCH2AsPh2) are reported for MX = AgCl, Br; CuI, CN/Cl (all isomorphous) and AgI, AgSCN, CuSCN arrays, all being of the novel form [(μ-X){M(μ-X)(As-dpam-As′)2M′}], essentially the familiar M(E-dpem-E′)2M′ binuclear array with both ‘bridging’ and (linking) ‘terminal’ (pseudo-)halides involved in the polymer. A different arrangement of bridging and linking entities is found with AgX:dpae (1:1)2(∞|∞), X = Br, NCO, ‘dpae’ = Ph2As(CH2)2AsPh2, now comprising [M(μ-X)2(As-dpae-As)M] kernels linked by As-dpae-As′, while in the thiocyanate analogue units are linked by the dpae ligands into a two-dimensional web. Synthetic procedures for all adducts have been reported. All compounds have been characterized both in solution (1H, 13C, 31P NMR, ESI MS) and in the solid state (IR).  相似文献   

15.
Cobalt(III) and rhodium(III) complexes of the series of [MIIICl3 − n(P)3 + n]n+ (M = Co or Rh; n = 0, 1, 2 or 3) have been prepared with the use of 1,1,1-tris(dimethylphosphinomethyl)ethane (tdmme) and mono- or didentate phosphines. The single-crystal X-ray analyses of both series of complexes revealed that the M-P and M-Cl bond lengths were dependent primarily on the strong trans influence of the phosphines, and secondarily on the steric congestion around the metal center resulting from the coordination of several phosphine groups. In fact, the M-P(tdmme) bonds became longer in the order of [MCl3(tdmme)] < [MCl2(tdmme)(PMe3)]+ < [MCl(tdmme)(dmpe)]2+ (dmpe = 1,2-bis(dimethylphosphino)ethane) < [M(tdmme)2]3+ for both CoIII and RhIII series of complexes, while the M-Cl bond lengths were shortened in this order (except for [M(tdmme)2]3+). Such a steric congestion around the metal center can also account for the structural and spectroscopic characteristics of the series of complexes, [MCl(tdmme)(dmpm, dmpe or dmpp)]2+ (dmpm = bis(dimethylphosphino)methane, dmpp = 1,3-bis(dimethylphosphino)propane). The X-ray analysis for [CoCl(tdmme)(dmpm or dmpe)](BF4)2 showed that all Co-P bonds in the dmpm complex were shorter by 0.03-0.04 Å than those in the dmpe complex. Furthermore, the first d-d transition energy of the CoIII complexes and the 1JRh-P(tdmme) coupling constants observed for the RhIII complexes indicated an unusual order in the coordination bond strengths of the didentate diphosphines, i.e., dmpm > dmpe > dmpp.  相似文献   

16.
17.

Background

Polymorphisms in apolipoprotein A5 gene (APOA5) have been associated with higher triglyceride levels in many populations. The aim of the study was to determine the allelic and genotypic distribution of the APOA5 − 1131T > C polymorphism and to identify the association of the genetic variant and the risk for dyslipidemia.

Methods

We genotyped 109 dyslipidemic subjects and 107 controls. The total cholesterol, triglycerides and HDL-c were determined enzymatically. Comparison of means among groups was calculated by ANOVA. Significant differences among groups were evaluated by Student–Newman–Keuls test.

Results

The minor allele C was more frequent in dyslipidemic subjects than controls (p = 0.019) and confers an increased individual risk for dyslipidemia (OR = 1.726, CI 95% = 1.095–2.721). The genotype analysis by gender showed that this allele was more frequent in dyslipidemic males (p = 0.037; OR = 2.050, CI 95% = 1.042–4.023). When participants were analyzed according to genotypes TT and TC/CC, C-carriers presented higher cholesterol and triglycerides levels than TT homozygous (p = 0.046 and 0.049, respectively).

Conclusions

The allele C confers higher total cholesterol and triglycerides levels in dyslipidemic adults. The APOA5 − 1131T > C polymorphism is associated with dyslipidemia in male subjects.  相似文献   

18.
19.

Background/aims

A large number of studies have shown that polymorphisms in the tumor necrosis factor-α (TNF-α, TNFA) gene are implicated in susceptibility to tuberculosis (TB). However, the results are inconsistent. We performed this meta-analysis to estimate the association between polymorphisms in the TNFA gene and TB susceptibility.

Methods

Relevant studies published before March 2012 were identified by searching PubMed, ISI web of knowledge, EBSCO and CNKI. The strength of relationship between the TNFA gene and TB susceptibility was assessed using odds ratios (ORs).

Results

A total number of twenty-three case–control studies including 3630 cases and 4055 controls were identified referring to three previously chosen single-nucleotide polymorphisms (SNPs): − 308G>A, − 863C>A and − 857C>T. No association was found between − 308G>A, − 863C>A and TB susceptibility: − 308G>A (GG + GA vs. AA): OR 0.85, 95%CI: 0.55–1.30, P = 0.44; − 863C>A (CC + CA vs. AA): OR 0.93, 95%CI: 0.84–1.81, P = 0.83. Increased risk of TB was associated with − 857C>T in the dominant genetic model (CC + CT vs. TT: OR 2.13, 95%CI: 1.25–3.63, P = 0.01), the heterozygote comparison (CT vs. TT: OR 2.69, 95%CI: 1.44–5.02, P = 0.00) and the homozygote comparison (CC vs. TT: OR 2.08, 95%CI: 1.22–3.53, P = 0.01) in Asian subjects.

Conclusion

There is an increased association between TNFA − 857C>T polymorphism and TB risk among Asian subjects. No association was found between − 308G>A and − 863C>A with TB risk. Due to several limitations in the present study, well-designed epidemiological studies with large sample size among different ethnicities should be performed in the future.  相似文献   

20.
Synthesis, X-ray crystal structure and IR spectrum of {[MnII(Im)6] · 2(2-IC) · 2(NC) · 2(DMSO)} (Im = imidazole, 2-HIC = indole-2-carboxylic acid, NC = 2,9-dimethyl-1,10-phenanthroline, DMSO = dimethyl sulfoxide) are reported. The manganese(II) ion has octahedral geometry with a MnN6 core. The crystal structure is completed by two NC, two 2-IC and two DMSO solvate molecules. The individual cations are linked into chains running parallel to the a axis by four intermolecular hydrogen bonding involving two 2-ICsolvate. Moreover, these chains are connected by π-π stacking interactions which occur between neocuproine molecules related through inversion center. In IR spectroscopy, the compound spectrum is roughly similar to the imidazole one: (i) above 1800 cm−1, the bands are broad, but when focussing on some of them a doublet structure can be found; (ii) below 1800 cm−1, the bands are sharp and it is then possible to point out the modification of S-O band when this later is involved in bifurcated hydrogen bonding to a second solvate 2-IC. The compound catalyses the disproportionation of H2O2; moreover an additional quantity of imidazole increases the reaction rate.  相似文献   

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