Asymmetrically Difunctionalized 1,1′-Ferrocenyl Metalloligands and Their Transition Metal Complexes

FcBipy: Novel redox-active bipyridine ligands based on 1,1′ difunctionalized ferrocenyl backbone, in conjunction with their metal complexes, are reported. The influence of the implemented functional groups on both the iron-centred redox potential and the N,N′-coordinated nickel complexes were confirmed for the reductive elimination reaction of an aryl ether induced by oxidation of the corresponding methoxides

Photocatalytic Reduction of CO2_2 by Highly Efficient Homogeneous FeII^{II} Catalyst based on 2,6‐Bis(1’,2’,3’‐triazolyl‐methyl)pyridine - Comparison with Analogues

Fully earth-abundant and highly efficient systems for producing syngas CO/H$_2$ through photocatalytic reduction from CO$_2$ are essential to approach a sustainable way of closing the carbon cycle. Herein, the synthesis and characterization of a new iron complex, Fe$^{II}$L(NCS)$_2$py, coordinated to an N,N,N-pincer ligand 2,6-bis(4’-phenyl-1’,2’,3’-triazol-1’-yl-methyl)pyridine (L), two isothiocyanate groups (NCS) and one pyridine is reported. Its catalytic activity in the photo-driven reduction of carbon dioxide has been investigated and compared with its Co$^{II}$ analogue (CoL(NCS)$_2$py) and their homoleptic complexes ML$_2$. In this work, the catalysts are used in combination with the heteroleptic complex [Cu$^I$(dmp)(DPEphos)], where dmp is 2,9-dimethyl-1,10-phenanthroline and DPEPhos is bis[(2-diphenylphosphino)phenyl] ether, to reach entirely earth-abundant systems. The new iron heteroleptic complex Fe$^{II}$L(NCS)$_2$py showed considerable activity with a TON$_{CO}$ of 576 obtained after 4 h (TOF=144 h$^{−1}$) through visible light (λ=420 nm) and a quantum yield of 7.1 %

Delocalized nonlinear vibrational modes in graphene: second harmonic generation and negative pressure

With the help of molecular dynamics simulations, delocalized nonlinear vibrational modes (DNVM) in graphene are analyzed. Such modes are dictated by the lattice symmetry, they are exact solutions to the atomic equations of motion, regardless the employed interatomic potential and for any mode amplitude (though for large amplitudes they are typically unstable). In this study, only one‐ and two‐component DNVM are analyzed, they are reducible to the dynamical systems with one and two degrees of freedom, respectively. There exist 4 one‐component and 12 two‐component DNVM with in‐plane atomic displacements. Any two‐component mode includes one of the one‐component modes. If the amplitudes of the modes constituting a two‐component mode are properly chosen, periodic in time vibrations are observed for the two degrees of freedom at frequencies ω and 2ω, that is, second harmonic generation takes place. For particular DNVM, the higher harmonic can have frequency nearly two times larger than the maximal frequency of the phonon spectrum of graphene. Excitation of some of DNVM results in the appearance of negative in‐plane pressure in graphene. This counterintuitive result is explained by the rotational motion of carbon hexagons. Our results contribute to the understanding of nonlinear dynamics of the graphene lattice

Cooperativity‐Driven Reactivity of a Dinuclear Copper Dimethylglyoxime Complex

In this report, we present the dinuclear copper(II) dimethylglyoxime (H$_2$dmg) complex [Cu$_2$(H$_2$dmg)(Hdmg)(dmg)]$^+$ (1), which, in contrast to its mononuclear analogue [Cu(Hdmg)$_2$] (2), is subject to a cooperativity-driven hydrolysis. The combined Lewis acidity of both copper centers increases the electrophilicity of the carbon atom in the bridging μ$_2$-O−N=C-group of H$_2$dmg and thus, facilitates the nucleophilic attack of H2O. This hydrolysis yields butane-2,3-dione monoxime (3) and NH$_2$OH that, depending on the solvent, is then either oxidized or reduced. In ethanol, NH$_2$OH is reduced to NH$_4$$^+$, yielding acetaldehyde as the oxidation product. In contrast, in CH$_3$CN, NH$_2$OH is oxidized by Cu$^{II}$ to form N$_2$O and [Cu(CH$_3$CN)4]$^+$. Herein are presented the combined synthetic, theoretical, spectroscopic and spectrometric methods that indicate and establish the reaction pathway of this solvent-dependent reaction

Comparison of the Effect of Natural Turpentine and Synthetic Sugar Free Gums on Dental Plaque pH Recovery

Introduction:Many different kinds of chewing gum can increase the flow of saliva, and they have been proven to have anti-bacterial effects as well. The aim of this study was to compare the effect of natural turpentine and synthetic sugar-free gums on dental plaque pH after a sucrose challenge. Methods: This randomized clinical trial was conducted on 15 subjects, who refrained from oral hygiene for two days and rinsed with 10% sucrose solution. Then for 30 minutes, they chewed one of three sugar-free gums: Van (natural), Orbit Complete, Orbit (synthetic), or one sugar-containing chewing gum (Banana). One group did not receive any gum (control group). Plaque pH was measured by the plaque sampling method before rinsing with sucrose, and 5, 10, 15, 20, and 30 minutes after chewing. Results: The lowest plaque pH drop was seen in the Orbit Complete group, and the highest was in the Banana group. The pH increased faster with Van and Orbit Complete gums. The plaque pH was more than baseline pH after 20 minutes in the Van and Orbit Complete groups (

The Role of Different Organism, Task and Environment Constraints in Coincidence Anticipation Timing Accuracy

Perceptual-motor skills play a vital role in many tasks of daily life and sports skills. The measurement of coincidence anticipation timing ability is a method to evaluate perceptual and perceptual-motor skills. Thus, the main aim of the present study was to investigate the role of different organism, task and environment constraints in coincidence anticipation timing accuracy. For this purpose, 30 female adolescents (17-15 years old), young (20-40 years old) and elderly (60-80 years old) participated in 4 tests of coincidence anticipation timing. The tests included a coincidence anticipation timing task with green (1), blue (2), red (3) color background and an additional environment constraint (4) and participants had to coincide with the arrival of the stimulus in the target point and press the corresponding key. For data analysis, mixed ANOVA (3*4), 4 one-way ANOVA and 3 ANOVA with repeated measures were used for each group with adjusted Bonferroni. Statistical analysis showed a significant difference in test 1, 3 and 4 (P≤0.0125). Also, all groups showed a significant reduction in performance when the background color changed from green to red and the addition of the secondary task (P≤0.017). In addition, results indicated that the elderly group had the weakest performance compared with the adolescent and young groups and the reason might be a weakness in perceptual-motor systems related to age increase. Finally, different coincidence anticipation training programs were recommended for athletes, elderly and patients with perceptual-motor system weakness

Killer cell immunoglobulin-like receptors (KIRs) genotype and haplotype analysis in Iranians with non-melanoma Skin Cancers

Background: The innate immune system against malignancies is mainly orchestrated by natural killer cells, which carry out killing mechanisms by using their receptors, such as killer immunoglobulin-like receptors (KIRs). This study was designed to determine the diversity of KIR genes in non-melanoma skin cancers. Methods: A total of 160 subjects with skin cancer, including 60 cases of squamous cell carcinoma and 100 cases of basal cell carcinoma (BCC), and 270 healthy subjects formed the study groups. The sequence-specific polymerase chain reaction was carried out to detect the presence or absence of 16 KIR genes. Results: KIR3DL1 (p = 0.0381, OR = 4.78, 95% CI = 1.108 to 20.62) increased in BCC patients compared to healthy controls. Conclusion: We concluded that the higher frequency of KIR3DL1 in BCC patients compared with healthy controls may increase the probability of developing BCC in Iranians. keywords:Basal cell carcinoma KIR Natural killer cells Receptors Squamous cell carcinom

Coexistence of inhibitory and activating killer-cell immunoglobulin-like receptors to the same cognate HLA-C2 and Bw4 ligands confer breast cancer risk.

Human leukocyte antigen (HLA) class I-specific killer-cell immunoglobulin-like receptors (KIR) regulate natural killer (NK) cell function in eliminating malignancy. Breast cancer (BC) patients exhibit reduced NK-cytotoxicity in peripheral blood. To test the hypothesis that certain KIR-HLA combinations impairing NK-cytotoxicity predispose to BC risk, we analyzed KIR and HLA polymorphisms in 162 women with BC and 278 controls. KIR-Bx genotypes increased significantly in BC than controls (83.3% vs. 71.9%, OR 1.95), and the increase was more pronounced in advanced-cancer (OR 5.3). No difference was observed with inhibitory KIR (iKIR) and HLA-ligand combinations. The activating KIR (aKIR) and HLA-ligand combinations, 2DS1 + C2 (OR 2.98) and 3DS1 + Bw4 (OR 2.6), were significantly increased in advanced-BC. All patients with advanced-cancer carrying 2DS1 + C2 or 3DS1 + Bw4 also have their iKIR counterparts 2DL1 and 3DL1, respectively. Contrarily, the 2DL1 + C2 and 3DL1 + Bw4 pairs without their aKIR counterparts are significantly higher in controls. These data suggest that NK cells expressing iKIR to the cognate HLA-ligands in the absence of putative aKIR counterpart are instrumental in antitumor response. These data provide a new framework for improving the utility of genetic risk scores for individualized surveillance

Coexistence of inhibitory and activating killer-cell immunoglobulin-like receptors to the same cognate HLA-C2 and Bw4 ligands confer breast cancer risk.

Human leukocyte antigen (HLA) class I-specific killer-cell immunoglobulin-like receptors (KIR) regulate natural killer (NK) cell function in eliminating malignancy. Breast cancer (BC) patients exhibit reduced NK-cytotoxicity in peripheral blood. To test the hypothesis that certain KIR-HLA combinations impairing NK-cytotoxicity predispose to BC risk, we analyzed KIR and HLA polymorphisms in 162 women with BC and 278 controls. KIR-Bx genotypes increased significantly in BC than controls (83.3% vs. 71.9%, OR 1.95), and the increase was more pronounced in advanced-cancer (OR 5.3). No difference was observed with inhibitory KIR (iKIR) and HLA-ligand combinations. The activating KIR (aKIR) and HLA-ligand combinations, 2DS1 + C2 (OR 2.98) and 3DS1 + Bw4 (OR 2.6), were significantly increased in advanced-BC. All patients with advanced-cancer carrying 2DS1 + C2 or 3DS1 + Bw4 also have their iKIR counterparts 2DL1 and 3DL1, respectively. Contrarily, the 2DL1 + C2 and 3DL1 + Bw4 pairs without their aKIR counterparts are significantly higher in controls. These data suggest that NK cells expressing iKIR to the cognate HLA-ligands in the absence of putative aKIR counterpart are instrumental in antitumor response. These data provide a new framework for improving the utility of genetic risk scores for individualized surveillance