Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Chemistry ; 27(16): 5171-5179, 2021 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-33300620

RESUMO

1,2,3,4-Tetrahydroquinolines should be applicable to the development of new pharmaceutical agents. A facile synthesis of 1,2,3,4-tetrahydroquinolines that is achieved by a photoinduced formal [4+2] cycloaddition reaction of acyclic α,ß-unsaturated amides and imides with N,N-dialkylanilines under visible-light irradiation, in which a new IrIII complex photosensitizer, a thiourea, and an oxidant act cooperatively in promoting the reaction, is reported. The photoreaction enables the synthesis of a wide variety of 1,2,3,4-tetrahydroquinolines, while controlling the trans/cis diastereoselectivity (>99:1) and constructing contiguous stereogenic centers. A chemoselective cleavage of an acyclic imide auxiliary is demonstrated.

2.
Chemistry ; 25(60): 13728-13738, 2019 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-31376186

RESUMO

Realization of molecular quantum cellular automata (QCA), a promising architecture for molecular computing through current-free processes, requires improved understanding and application of mixed-valence (MV) molecules. In this report, we present an electrostatic approach to creating MV subspecies through internalizing opposite charges in close proximity to MV ionic moieties. This approach is demonstrated by unsymmetrically attaching a charge-responsive boron substituent to a well-known organometallic MV complex, biferrocenium. Guest anions (CN- and F- ) bind to the Lewis acidic boron center, leading to unusual blue-shifts of the intervalence charge-transfer (IVCT) bands. To the best of our knowledge, this is the first reported example of a zwitterionic MV series in which the degree of positive charge delocalization can be varied by changing the bound anions, and serves to clarify the interplay between IVCT parameters. The key underlying factor is the variable zero-level energy difference in the MV states. This work provides new insight into imbuing MV molecules with external charge-responsiveness, a prerequisite of molecular QCA techniques.

3.
J Org Chem ; 84(14): 8910-8920, 2019 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-31072099

RESUMO

In this study, we report the generation of new mixed-valence (MV) subspecies with charge-separated (CS) characters from an unsymmetrical acceptor-donor-donor (A-D-D) triad. The triad was synthesized by attaching a dimesitylboryl group (A) to a D-D conjugate that consisted of triarylamine (NAr3) units. The MV radical cation, obtained by chemical oxidation of the triad, exhibited a strong intervalence charge transfer (IVCT) absorption derived from the bis(NAr3)•+ moiety in the near-IR region. The charge-separated MV (CSMV) state, obtained by photoexcitation of the triad, caused a blue shift in IVCT energy in the femtosecond transient absorption spectra, reflecting a bias of positive charge distributions to the D end site. This resulted from increased electron density at the A site and restructuring of the central D site from NAr3 to NAr2 sites. Interestingly, any shift in the IVCT energy that was caused by the polarity of the solvent was minimal, reflecting the unique characteristics of the CSMV state. These findings represent the first detailed analysis of the CSMV state, including a comparison with conventional MV states. Therefore, this work provides new insights into counterion-free MV systems and their applications in molecular devices.

4.
J Appl Biomech ; 32(5): 454-61, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27249655

RESUMO

This study evaluated the effect of foot progression angle on the reduction in knee adduction moment caused by a lateral wedged insole during walking. Twenty healthy, young volunteers walked 10 m at their comfortable velocity wearing a lateral wedged insole or control flat insole in 3 foot progression angle conditions: natural, toe-out, and toe-in. A 3-dimensional rigid link model was used to calculate the external knee adduction moment, the moment arm of ground reaction force to knee joint center, and the reduction ratio of knee adduction moment and moment arm. The result indicated that the toe-out condition and lateral wedged insole decreased the knee adduction moment in the whole stance phase. The reduction ratio of the knee adduction moment and the moment arm exhibited a close relationship. Lateral wedged insoles decreased the knee adduction moment in various foot progression angle conditions due to decrease of the moment arm of the ground reaction force. Moreover, the knee adduction moment during the toe-out gait with lateral wedged insole was the smallest due to the synergistic effect of the lateral wedged insole and foot progression angle. Lateral wedged insoles may be a valid intervention for patients with knee osteoarthritis regardless of the foot progression angle.


Assuntos
Pé/fisiologia , Articulação do Joelho/fisiologia , Sapatos , Caminhada/fisiologia , Desenho de Equipamento , Feminino , Voluntários Saudáveis , Humanos , Masculino , Osteoartrite do Joelho/fisiopatologia , Adulto Jovem
5.
J Appl Biomech ; 31(6): 476-83, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26252560

RESUMO

The purpose of this study was to determine whether a lateral wedge insole reduces the external knee adduction moment during slope walking. Twenty young, healthy subjects participated in this study. Subjects walked up and down a slope using 2 different insoles: a control flat insole and a 7° lateral wedge insole. A three-dimensional motion analysis system and force plate were used to examine the knee adduction moment, the ankle valgus moment, and the moment arm of the ground reaction force to the knee joint center in the frontal plane. The lateral wedge insole significantly decreased the moment arm of the ground reaction force, resulting in a reduction of the knee adduction moment during slope walking, similar to level walking. The reduction ratio of knee adduction moment by the lateral wedge insole during the early stance of up-slope walking was larger than that of level walking. Conversely, the lateral wedge insole increased the ankle valgus moment during slope walking, especially during the early stance phase of up-slope walking. Clinicians should examine the utilization of a lateral wedge insole for knee osteoarthritis patients who perform inclined walking during daily activity, in consideration of the load on the ankle joint.


Assuntos
Articulação do Tornozelo/fisiologia , Órtoses do Pé , Marcha/fisiologia , Articulação do Joelho/fisiologia , Amplitude de Movimento Articular/fisiologia , Caminhada/fisiologia , Adaptação Fisiológica/fisiologia , Adulto , Desenho de Equipamento , Análise de Falha de Equipamento , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Sapatos
6.
Anticancer Res ; 40(8): 4701-4706, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32727795

RESUMO

BACKGROUND/AIM: Bovine mastitis is caused by the invasion and propagation of pathogenic microorganisms into the udder and mammary gland tissues of cattle. In this study, the therapeutic effect of a low-molecular-weight whey protein (LMW-WP) on bovine mastitis was evaluated. MATERIALS AND METHODS: LMW-WP was orally, intraperitoneally, and vaginally administered to bovine with mastitis. The number of somatic cells in milk was measured 24 h before the administration of LMW-WP. The effect of LMW-WP on cytokine production was measured with a microarray that evaluates the expression of cytokines. RESULTS: In the group that received 1,000 mg intraperitoneally, the somatic cell count was reduced to less than 400,000 at the shipment standard value in three of the four udders, indicating 75% efficacy. The group that received 1,000 mg by vaginal administration showed 67% efficacy. It was confirmed that LMW-WP increased the production of cytokines such as IL-5, IL-6, IL-9, IL-12, MCP-1, and VEGF in mouse macrophage cells, but it did not show any antibacterial activity. CONCLUSION: LMW-WP may be an effective therapeutic agent for bovine mastitis.


Assuntos
Macrófagos/efeitos dos fármacos , Mastite Bovina/tratamento farmacológico , Proteínas do Soro do Leite/farmacologia , Animais , Antibacterianos/farmacologia , Bovinos , Contagem de Células/métodos , Linhagem Celular , Citocinas/metabolismo , Feminino , Glândulas Mamárias Animais/metabolismo , Mastite Bovina/microbiologia , Camundongos , Leite/metabolismo , Células RAW 264.7
7.
Phys Rev E ; 100(6-1): 062608, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31962405

RESUMO

The motions of a solvation motor in a Lennard-Jones solvent were calculated by using molecular dynamics simulation. The results were analyzed considering the large spatial scale effects caused by the motion of the solvation motor. A reaction site was located on the surface of the solvation motor and the attraction between the reaction site and the solvent molecules was varied for 100 fs. The motion of the motor was driven by solvation changes near the reaction site on the motor. Two finite-size effects were observed in the motion. One was the hydrodynamic effect and the other was the increase in solvent viscosity caused by heat generation. The latter affected not only the displacement of the motor caused by the reaction but also the wave propagation phenomena. Both effects reduced the motor displacement. Heat generation affects the displacement, in particular for small systems. By contrast, the hydrodynamic effect remained even for large systems. An extrapolation method was proposed for the displacement.

8.
RSC Adv ; 9(22): 12365-12369, 2019 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-35515875

RESUMO

A novel asymmetric photodimerization reaction of coumarin derivatives bearing the (S)-4-benzyl-2-oxazolidinone auxiliary provides only the syn-head-to-tail (syn-HT) dimer with moderate diastereoselectivity (up to 75 : 25). The mechanism of complete syn-HT selectivity and moderate diastereoselectivity is proposed based on the result of density functional theory (DFT) calculation. The benzyl group of the (S)-4-benzyl-2-oxazolidinone auxiliary in combination with a Lewis acid exerts effective diastereofacial shielding of the reaction site.

9.
Anticancer Res ; 38(7): 4299-4304, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29970565

RESUMO

BACKGROUND/AIM: Whey protein is a mixture of globulins isolated from whey and mainly composed of ß-lactoglobulin, α-lactoalbumin, and lactoferrin. In this study, whey protein was hydrolyzed using various proteases, and the macrophage activation was evaluated. MATERIALS AND METHODS: Hydrolyzed whey protein was prepared using various proteases to evaluate phagocytic activity and cytokine productivity. RESULTS: The results of SDS-PAGE and gel permeation chromatography (GPC) analysis indicated that the molecular weight of whey protein was reduced using various proteases. The hydrolyzed whey protein showed a concentration-dependent induction of macrophage phagocytic activity. In addition, the hydrolyzed whey protein significantly enhanced the production of the inflammatory cytokine, TNF-α. Production of the anti-inflammatory cytokine, IL-10, was not observed at concentrations up to 1 µg, but significant production was confirmed at 100 µg. CONCLUSION: Hydrolyzed whey protein can induce the phagocytic activity of macrophages and activation of the inflammatory/anti-inflammatory functions of the macrophages depends on the concentration of the hydrolyzed whey protein.


Assuntos
Ativação de Macrófagos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Proteínas do Soro do Leite/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Feminino , Inflamação/imunologia , Camundongos , Camundongos Endogâmicos ICR
10.
Dalton Trans ; 44(33): 14635-45, 2015 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-26212616

RESUMO

In this study, we report intramolecular charge transfer (ICT) properties and charge distributions in a series of FcC derivatives (FcC = 4-ferrocenylcatecholate where Fc = ferrocene and C = catecholate). This series consists of a previously reported complex FcV (4-ferrocenylveratrole) and newly synthesized complexes FcA (4-ferrocenylcatechol bis(acetate) and Pt((t)Bu2bpy)(FcC) ((t)Bu2bpy = 4,4'-di-tert-butyl-2,2'-dipyridyl). An electrochemical analysis of Pt((t)Bu2bpy)(FcC) using cyclic voltammetry revealed two well-defined, reversible waves which were assigned to the sequential oxidation of the Pt((t)Bu2bpy)(C) and Fc moieties. The potential splitting between the waves (524 mV) indicated that there was an electronic interaction between both moieties. ICT property and charge distribution of [Pt((t)Bu2bpy)(FcC)]˙(+) were rationalized by comparison with the [FcV]˙(+) and [FcA]˙(+) (4-ferrocenylcatechol bis(acetate)). DFT calculations and UV-vis-NIR spectroscopy revealed that [Pt((t)Bu2bpy)(FcC)]˙(+), [FcV]˙(+), and [FcA]˙(+) were ferrocenium (Fc(+))-centered rather than semiquinone ligand-centered and that these complexes exhibited ICT transition bands from the catechol-derivatized framework to the Fc(+) moiety in the near infrared (NIR) region. Both the electronic coupling parameter (HAB) and delocalization parameter (α) increased in value as the electron-donating strength of the substituent groups in the catechol-derivatized framework increased (OCOCH3 ([FcA]˙(+)) < OCH3 ([FcV]˙(+)) < O(-) ([Pt((t)Bu2bpy)(FcC)]˙(+))). The electronic interactions between the organometallic center and the non-innocent framework were tuned by changing the substituents. The potential energy surfaces of the Fc(+) derivatives, obtained using two-state Marcus-Hush theory, can be modulated by changing the energy level of the molecular orbitals of the appended catechol-derivatized moieties.

11.
Anticancer Res ; 35(8): 4487-92, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26168491

RESUMO

BACKGROUND/AIM: Colostrum contains antibodies, such as immunoglobulin G (IgG), immunoglobulin A (IgA) and immunoglobulin M (IgM), and, therefore, has potent immunomodulating activity. In particular, IgA has an O-linked sugar chain similar to that in the group-specific component (Gc) protein, a precursor of the Gc protein-derived macrophage-activating factor (GcMAF). In the present study, we investigated the macrophage-activating effects of degalactosylated/desialylated bovine colostrum. RESULTS: We detected the positive band in degalactosylated/ desialylated bovine colostrum by western blotting using Helix pomatia agglutinin lectin. We also found that degalactosylated/ desialylated bovine colostrum could significantly enhance the phagocytic activity of mouse peritoneal macrophages in vitro and of intestinal macrophages in vivo. Besides, degalactosylated/desialylated bovine colostrum did not mediate the production of inflammatory cytokines such as tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß). CONCLUSION: Similar to the use of GcMAF, degalactosylated/desialylated bovine colostrum can be used as a potential macrophage activator for various immunotherapies.


Assuntos
Colostro/imunologia , Imunomodulação , Interleucina-1beta/biossíntese , Ativação de Macrófagos/imunologia , Macrófagos Peritoneais/imunologia , Fator de Necrose Tumoral alfa/biossíntese , Animais , Bovinos , Feminino , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Lectinas/imunologia , Fatores Ativadores de Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fagocitose , Gravidez , Proteína de Ligação a Vitamina D/imunologia
12.
Dalton Trans ; 43(25): 9579-85, 2014 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-24827859

RESUMO

1',1'''-Biferrocenediboronic acid () was synthesized from 1',1'''-dibromobiferrocene by a typical procedure of converting Br to B(OH)2 groups in 76% yield and identified by (1)H-, (13)C- and (11)B-NMR and ESI-MS. X-ray diffraction (XRD) studies showed that, in non-solvated crystals (Form I), the new organobimetallic building block formed 1D hydrogen-bonded networks (i.e., chain) with octaatomic rings composed of the neighbouring two molecules. In solvated crystals with a composition of ()3(THF)2 (Form II), exists in two conformers (Conformers A and B) with respect to the rotation of the CpB(OH)2 moieties relative to the Cp rings of the fulvalenide moieties; Conformer A formed 1D hydrogen-bonded networks laterally hydrogen-bonding with THF molecules while Conformer B formed a new planar hydrogen-bonded motif involving four B(OH)2 groups and stepwise laminated networks of the planar motif. A macrocyclic tetraferrocenyl boronate ester was synthesized by cyclocondensation between and pentaerythritol in 33% yield and identified by (1)H-, (13)C- and (11)B-NMR, ESI-MS and XRD. In electrochemical measurements, the cyclocondensed compound exhibited four defined reversible waves with a total spread of 756 mV in CH2Cl2 containing n-Bu4NBArF4 (ArF = 3,5-bis(trifluoromethyl)phenyl), displaying both intra- and inter-biferrocenyl interactions.

13.
Materials (Basel) ; 3(8): 4277-4290, 2010 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-28883329

RESUMO

Dynamic behavior of signal transmission through metal complexes [L5M-BL-ML5]5+ (M=Fe, Ru, Os, BL=pyrazine (py), 4,4'-bipyridine (bpy), L=NH3), which are simplified models of the molecular quantum-dot cellular automata (molecular QCA), is discussed from the viewpoint of one-electron theory, density functional theory. It is found that for py complexes, the signal transmission time (tst) is Fe(0.6 fs) < Os(0.7 fs) < Ru(1.1 fs) and the signal amplitude (A) is Fe(0.05 e) < Os(0.06 e) < Ru(0.10 e). For bpy complexes, tst and A are Fe(1.4 fs) < Os(1.7 fs) < Ru(2.5 fs) and Os(0.11 e) < Ru(0.12 e)

14.
Phys Chem Chem Phys ; 11(10): 1474-83, 2009 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-19240923

RESUMO

Signal transmission through Creutz-Taube complexes [(NH(3))(5)Ru-BL-Ru(NH(3))(5)](5+)(BL = pyrazine (py), 4,4'-bipyridine (bpy)), which are simplified models of the molecular quantum-dot cellular automata (molecular QCA), is discussed both statically and dynamically with a view to designing useful molecular QCA. In the static treatment, the difference between stationary states before and after the switch of the input to the molecular QCA is discussed. In the dynamic treatment, time-evolution of electronic structure after the moment of the switch is simulated, and a simple method for the simulation is also proposed. Geometric and electronic structures are obtained by density functional theory (UB3LYP) and Hartree-Fock (UHF) calculations, and discussions are based on the Mulliken charge. It is found that signal amplitude (A) is strongly dependent on the position and charge of the input to the molecular QCA, but signal period (T) is almost independent of them. These results are explained from molecular orbitals and orbital energies, and a set of large A (large overlap between orbitals) and small T (large energy gap) generally leads to a prompt signal transmission.

15.
J Phys Chem A ; 112(4): 758-67, 2008 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-18181586

RESUMO

Vibronic coupling, or electron-phonon coupling, of naphthalene is calculated. A method of vibronic coupling density analysis, which has been proposed for the vibronic coupling of the Jahn-Teller active modes in a Jahn-Teller molecule, is extended for totally symmetric vibrational modes of a molecule including a non-Jahn-Teller molecule. Contrary to non-totally-symmetric modes, orbital relaxation upon a charge transfer plays a crucial role in the vibronic coupling calculation for the totally symmetric modes. The method is applied for the ground state of the naphthalene anion to compare with that of the benzene anion. The relationship between the vibronic coupling density and a nuclear Fukui function is also discussed.

16.
J Chem Phys ; 124(2): 024314, 2006 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-16422590

RESUMO

A method of calculation of vibronic or electron-phonon coupling constant is presented for a Jahn-Teller molecule, cyclopentadienyl radical. It is pointed out that symmetry breaking at degenerate point and violation of Hellmann-Feynman theorem occur in the calculations based on a single Slater determinant. In order to overcome these difficulties, the electronic wave functions are calculated using generalized restricted Hartree-Fock and complete active space self-consistent-field method and the couplings are computed as matrix elements of the electronic operator of the vibronic coupling. Our result agrees well with the experimental and theoretical values. A concept of vibronic coupling density is proposed in order to explain the order of magnitude of the coupling constant from view of the electronic and vibrational structures. It illustrates the local properties of the coupling and enables us to control the interaction. It could open a way to the engineering of vibronic interactions.

17.
J Chem Phys ; 124(15): 154303, 2006 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-16674222

RESUMO

Vibronic coupling constants of Jahn-Teller molecules, benzene radical cation and anion, are computed as matrix elements of the electronic part of the vibronic coupling operator using the electronic wave functions calculated by generalized restricted Hartree-Fock and state-averaged complete active space self-consistent-field methods. The calculated vibronic coupling constants for benzene cation agree well with the experimental and theoretical values. Vibronic coupling density analysis, which illustrates the local properties of the coupling, is performed in order to explain the order of magnitude of the coupling constant from view of the electronic and vibrational structures. This analysis reveals that the couplings of the e2g2 and e2g3 modes in which the large displacements locate on C-C bonds are strong in the cation. On the other hand, they are greatly weakened in the anion because of the decrease of electron density in the region of the C-C bonds, which originates from the antibonding nature of the singly occupied molecular orbital of the anion. However, the difference of the electronic structure has a little influence on the vibronic coupling of the e2g4 mode. These results indicate that the vibronic coupling depends not only on the direction of the nuclear displacement but also on the frontier electron density.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA