RESUMO
Spin crossover (SCO) materials that possess switchable and cooperative fluorescence have long focused interest in photonic sensor devices to monitor the variations in the physicochemical parameters of the external environment. However, the lack of quantified cooperativity for the SCO transition operating in isolated molecules is detrimental to short-term technological applications. In this study, a pretwisted energy D-A system combining the deep-blue naphthalimide fluorophore (donor) and the FeN6 SCO chromophore (switchable acceptor) has been developed with the formula of Fe(naph-abpt)2(NCS)2·2DMF (1), where naph-abpt is N-[3,5-di(pyridin-2-yl)-4H-1,2,4-triazol-4-yl]-1,8-naphthalimide. Dual emission from the naphthalimide function based on its vibronic structure exhibits a different synergy effect with SCO, providing a new platform for ratiometric fluorescence thermosensing. Theoretical calculations and optical experimental results demonstrate an excellent correlation between luminescence intensity ratio signals and magnetic data of spin transition, promising a high sensitivity of the optical activity of the ligand to the spin state of the active iron(II) ions, with the maximum relative sensitivity as 0.7% K-1 around T1/2.
RESUMO
Emerging reports demonstrated that long non-coding RNAs (lncRNAs) play a role in the pathogenesis and metastasis of cancers. However, the biological functions and underlying mechanisms of LncRNA CEBPA-AS1 in acute myeloid leukemia (AML) remain largely elusive. The level of CEBPA-AS1 was examined in AML clinical tissues and cell lines via fluorescence in situ hybridization (FISH) and reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In vivo and in vitro functional tests were applied to identify the pro-oncogenic role of CEBPA-AS1 in AML development. The overexpressed CEBPA-AS1 was linked to poor survival in AML patients. Moreover, the relationships among CEBPA-AS1, Zinc Finger Protein X-Linked (ZFX), and miR-24-3p were predicted by bioinformatics and validated by RNA immunoprecipitation (RIP) and luciferase reporter assays. Our findings unveiled that transcription factor ZFX particularly interacted with the promoter of CEBPA-AS1 and activated CEBPA-AS1 transcription. Downregulation of CEBPA-AS1 inhibited the proliferation and invasion while promoted apoptosis of AML cells in in vitro, as well as in vivo, xenograft tumor growth was modified. However, overexpression of CEBPA-AS1 observed the opposite effects. Furthermore, CEBPA-AS1 acted as a competitive endogenous RNA (ceRNA) of miR-24-3p to attenuate the repressive effects of miR-24-3p on its downstream target CTBP2. Taken together, this study emphasized the pro-oncogenic role of CEBPA-AS1 in AML and illustrated its connections with the upstream transcription factor ZFX and the downstream regulative axis miR-24-3p/CTBP2, providing important insights to the cancerogenic process in AML.
Assuntos
Leucemia Mieloide Aguda , MicroRNAs , RNA Longo não Codificante , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Regulação para Cima/genética , Linhagem Celular Tumoral , Hibridização in Situ Fluorescente , Leucemia Mieloide Aguda/genética , Fatores de Transcrição/genética , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/genética , Movimento Celular/genética , Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Proteínas Correpressoras/genética , Proteínas Correpressoras/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/genética , Proteínas Estimuladoras de Ligação a CCAAT/metabolismoRESUMO
BACKGROUND: We aimed to investigate the different metastases and prognoses of neuroblastoma (NB) and determine the risk factors of metastasis. METHOD: Data of 1224 patients with NB were obtained from the Surveillance, Epidemiology and End Results database (2010-2018). Pearson's chi-square test, Kaplan-Meier analysis, multivariable logistic regression and Cox regression analysis were used to determine the factors associated with prognosis. RESULTS: The overall incidence of NB was an age-adjusted rate of 8.2 patients per 1,000,000 children. In total, 1224 patients were included in our study, with 599 patients (48.9%) exhibiting distant metastases. Compared to patients with non-metastatic NB, a greater proportion of patients with metastatic NB were under 1 year, male, had an adrenal primary site, unilateral tumour, a tumour size > 10 cm, neuroblastoma-not otherwise specified (NB-NOS), second malignant neoplasms and were more likely to choose radiotherapy and chemotherapy. Multivariate Cox regression showed that metastasis was an independent risk factor for overall survival (OS) and cancer-specific survival (CSS). The survival rate of non-metastatic patients with NB was better than those with metastasis (OS: hazard ratio (HR): 0.248, P < 0.001; CSS: HR: 0.267, P < 0.001). The bone and liver were the two most common isolated metastatic sites in NB. However, no statistical difference was observed in OS and CSS between the only bone metastasis group, only liver metastasis group and bone metastasis combined with liver metastasis group (all P > 0.05). Additionally, age at diagnosis > 1 year (odds ratio (OR): 3.295, P < 0 .001), grades III-IV (OR: 26.228, P < 0 .001) and 5-10 cm tumours (OR: 1.781, P < 0 .001) increased the risk of bone metastasis of NB. Moreover, no surgical treatment (OR: 2.441, P < 0 .001) increased the risk of liver metastasis of NB. CONCLUSION: Metastatic NB has unique clinicopathological features, with the bone and liver as the most common single metastatic sites of NB. Therefore, more aggressive treatment is recommended for high-risk children with NB displaying distant metastases.
Assuntos
Doenças da Medula Óssea , Neoplasias Ósseas , Neoplasias Hepáticas , Neuroblastoma , Humanos , Masculino , Criança , Prognóstico , Neuroblastoma/terapia , Neuroblastoma/patologia , Fatores de Risco , Neoplasias Hepáticas/secundário , Programa de SEER , Metástase NeoplásicaRESUMO
A series of bulky substituted bipyridine-related iron(II) complexes [Fe(H2Bpz2)2(L)] (pz = pyrazolyl) were prepared, where L = 5,5'-dimethyl-2,2'-bipyridine (bipy-CH3, 1), L = dimethyl-2,2'-bipyridyl-5,5'-dicarboxylate (MeObpydc, 2), L = diethyl-2,2'-bipyridyl-5,5'-dicarboxylate (EtObpydc, 3), or L = diisopropyl-2,2'-bipyridine-5,5'-dicarboxylate ( i-PrObpydc, 4). The crystal structures of five new iron(II) complexes were determined by X-ray diffraction: those of 1, 3, and 4 and two modifications of 3 (3B) and 4 (4B). Complexes 1 and 3B display incomplete spin crossover (SCO) behavior because of a freezing-in effect, whereas 3 and 4B undergo gradual and incomplete SCO behaviors. Complexes 2 and 4 show a completely gradual and steep SCO, respectively. Such different SCO behaviors can be attributed to an electronic substituent effect in the bipyridyl ligand conformation and a crystal packing effect. Importantly, the electronic substituent effect of the isopropyl acetate group and C-H···O supramolecular interactions in 4 contribute to a highly cooperative behavior, which leads to an abrupt thermally induced spin transition.
RESUMO
Efficient modulation of single-molecule magnet (SMM) behavior was realized by deliberate structural modification of the Dy2 cores of [Dy2(a'povh)2(OAc)2(DMF)2] (1) and [Zn2Dy2(a'povh)2(OAc)6]â 4 H2O (2; H2a'povh = N'-[amino(pyrimidin-2-yl)methylene]-o-vanilloyl hydrazine). Compound 1 having fourfold linkage between the two dysprosium ions shows high-performance SMM behavior with a thermal energy barrier of 322.1â K, whereas only slow relaxation is observed for compound 2 with only twofold connection between the dysprosium ions. This remarkable discrepancy is mainly because of strong axiality in 1 due to one pronounced covalent bond, as revealed by experimental and theoretical investigations. The significant antiferromagnetic interaction derived from bis(µ2-O) and two acetate bridging groups was found to be crucial in leading to a nonmagnetic ground state in 1, by suppressing zero-field quantum tunneling of magnetization.
RESUMO
The magnetic relaxation dynamics of low-coordinate Dy(III) and Er(III) complexes, namely three-coordinate ones with an equatorially coordinated triangle geometry and five-coordinate ones with a trigonal bipyramidal geometry, have been exploited for the first time. The three-coordinate Er-based complex is the first equatorially coordinated mononuclear Er-based single-molecule magnet (SMM) corroborating that simple models can effectively direct the design of target SMMs incorporating 4f-elements.
RESUMO
Two new hexanuclear symmetric dysprosium wheels, namely, [Dy6(L1)6(L')6(OCH3)6(2CH3OH)] and [Dy6(L2)6(L')6(OCH3)6(2CH3OH)] (L1H = pivalic acid and L2H = 3,5-dinitrobenzoic acid, L'H= 2,6-dimethoxyphenol) were isolated employing a mixed-ligand strategy. The strategic introduction of two different auxiliary groups with diverse steric effects and electrostatic actions affect the magnetic coupling and local anisotropy of Dy(III) ion, therefore exhibiting dissimilar magnetic behaviors.
RESUMO
A defective cubane-shaped heterometallic trinuclear Co(III)2Dy(III) compound with only one magnetically interesting ion (Dy(III)) has been assembled by virtue of a multifunctional acylhydrazone ligand. Because of the nonaxial ground state of Dy(III) ion derived from a low-symmetrical crystal field, the title compound displays field-induced multiple relaxation processes which are of molecular and a dipolar-dipolar coupling origin, as revealed by combined experimental and theoretical investigations. The results demonstrate that such a mononuclear dysprosium(III) compound with a low-symmetrical environment of magnetic center appears to be a model system for further investigations to shed light on the complex relaxation mechanism of lanthanide-based single ion magnets.
RESUMO
Reaction of in situ prepared acylhydrazone ligand with Ln(NO3)3·6H2O and Cu(OAc)2·H2O resulted in the formation of novel isostructural octanuclear Cu6Ln2 compounds (Ln = Dy (1), Tb (2), Gd (3), Y (4)) with an unprecedented octametallic structure, which can be described as an oblate wheel built up from two structurally similar Cu3 fragments linked together by two nodelike mononuclear lanthanide units. A detailed magnetic analysis reveals that the strong antiferromagnetic Cu···Cu interactions via the Cu-N-N-Cu-N-N-Cu linkage and the anticipated ferromagnetic Cu···Gd coupling makes an overall high-spin ground state in favor of the observation of significant magnetic caloric and SMM-like properties in the isotropic and anisotropic derivatives.
RESUMO
Two new dinuclear dysprosium compounds, [Dy2(HL1)2(PhCOO)2(CH3OH)2] (1) and [Dy2(L2)2(NO3)2(CH3OH)2]·2CH3OH·4H2O (2), have been assembled through applying two ligands with different coordination pockets. The different features of ligands H3L1 and H2L2 result in the distinct coordination geometry of the metal ions in their respective structures. The Dy ions of complexes 1 and 2 were linked by the alkoxide- and hydrazone-O, and display the hula hoop-like and the broken hula hoop-like coordination geometry, respectively. Consequently, these two compounds show distinct magnetic properties. Complex 1 behaves as a single molecule magnet (SMM) with rather slow quantum tunneling rate (τ > 274 ms), while no SMM behavior was observed for complex 2. In addition, the comparison of the structural parameters among the similar Dy2 SMMs with hula hoop-like geometry reveals the significant role played by coordination geometry and magnetic interaction in modulating the relaxation dynamics of SMMs.
RESUMO
Reactions of lanthanide(III) (Ln(III)) perchlorate (Ln = Dy and Ho) and a polydentate Schiff base resulted in the unprecedented assembly of novel Ln(12) wheels containing six vertex-sharing Ln(3) triangles. The Dy(12) derivative represents the largest lanthanide wheel based on the peculiar Dy(3) triangles showing slow magnetic relaxation.
RESUMO
Complexation of dysprosium(III) with the heterodonor chelating ligand o-vanillin picolinoylhydrazone (H(2)ovph) in the presence of a carbonato ligand affords two novel Dy(6) and Dy(8) clusters, namely, [Dy(6)(ovph)(4)(Hpvph)(2)Cl(4)(H(2)O)(2)(CO(3))(2)]·CH(3)OH·H(2)O·CH(3)CN (2) and [Dy(8)(ovph)(8)(CO(3))(4)(H(2)O)(8)]·12CH(3)CN·6H(2)O (3). Compound 2 is composed of three petals of the Dy(2) units linked by two carbonato ligands, forming a triangular prism arrangement, while compound 3 possesses an octanuclear core with an unprecedented tub conformation, in which Dy(ovph) fragments are attached to the sides of the carbonato core. The static and dynamic magnetic properties are reported and discussed. In the Dy(6) aggregate, three Dy(2) "skeletons", having been well preserved (see the scheme), contribute to the single-molecule-magnet behavior with a relatively slow tunneling rate, while the Dy(8) cluster only exhibits a rather small relaxation barrier.
RESUMO
The self-assembly of dysprosium(III) with the tailored chemical modification of the vanillin group affords two decorated Dy(3) compounds, namely, [Dy(3)(µ(3)-OH)(2)(Hpovh(-))(3)(NO(3))(3)(CH(3)OH)(2)H(2)O]·NO(3)·3CH(3)OH·2H(2)O (2) and [Dy(3)(µ(3)-OH)(2)(H(2)vovh(-))(3)Cl(2)(CH(3)OH)(H(2)O)(3)][Dy(3)(µ(3)-OH)(2)(H(2)vovh(-))(3)Cl(2)(H(2)O)(4)]·Cl(4)·2CH(3)OH·2CH(3)CN·7H(2)O (3), where H(2)povh = N-(pyridylmethylene)-o-vanilloylhydrazone and H(3)vovh = N-vanillidene-o-vanilloylhydrazone. Of particular interest is that those two title Dy(3) compounds maintain the peculiar vortex-spin structure of the ground nonmagnetic doublet. Complex 2 displays frequency-dependent slow magnetic relaxation, while 3 still inherits the single-molecule-magnet behavior as the parent Dy(3) prototype. The dissimilar dynamic magnetic behavior originates from the structural differences in light of the coordination environment of Dy(III) ions, which influence the local tensor of anisotropy and crystal-field splitting on each Dy site.
RESUMO
Sigmoid colon cancer often has an unsatisfactory prognosis. This study explored the effect of tumor deposits (TDs) on survival, and whether their presence/absence influence individualized treatment. Data of postoperative patients with sigmoid colon cancer were extracted from the Surveillance, Epidemiology, and End Results database. Overall survival (OS) was calculated using the Kaplan-Meier method and prognostic factors were identified using Cox regression analysis and random forest (RF). The nomogram's discrimination performance was evaluated using a concordance index (C-index), integrated discrimination improvement (IDI), calibration curves, and decision-curve analysis. The N1c group showed a worse prognosis than the N0 group. For N1c patients, a combination of surgery and chemotherapy prolonged survival, compared to surgery alone; however, the chemotherapy-surgery combination did not affect the OS of patients younger than 70 years, in stage T1-2, and/or of black race. Multivariable analysis and RF presented Age, T stage, and N stage were the most important predictors for OS. The novel nomogram had superiority to the TNM staging system with improved C-index and IDI, as well as good consistency and higher clinical benefit. TDs are associated with poor survival from sigmoid colon cancer, and considering TDs can inform the formulation of individual treatment regimens. The nomogram shows satisfactory prediction ability for OS.
Assuntos
Neoplasias do Colo Sigmoide , Humanos , Extensão Extranodal , Estadiamento de Neoplasias , Nomogramas , Prognóstico , Programa de SEER , Neoplasias do Colo Sigmoide/tratamento farmacológico , Neoplasias do Colo Sigmoide/cirurgiaRESUMO
Vapor-triggered crystal-to-crystal transformation between a discrete trinuclear complex [Ni3(sih)2(py)8] and a two-dimensional (2D) coordination polymer [Ni3(sih)2(py)2]n·2DMF·2H2O was demonstrated. It provides an example of a solid-state coordination-induced spin state switch behavior attributed to the structural phase transition triggered by solvent signal. The reversible nature can be detected by both optical (spectral) and magnetic responses in cycles.
RESUMO
Complexation of dysprosium(III) with the heterodonor chelating ligand o-vanillin picolinoylhydrazone (H(2)ovph) in the presence of different bases affords three new dinuclear dysprosium(III) coordination compounds, namely, [Dy(2)(ovph)(2)(NO(3))(2)(H(2)O)(2)]·2H(2)O (1), [Dy(2)(Hovph)(ovph)(NO(3))(2)(H(2)O)(4)]·NO(3)·2CH(3)OH·3H(2)O (2), and Na[Dy(2)(Hovph)(2)(µ(2)-OH)(OH)(H(2)O)(5)]·3Cl·3H(2)O (3), where the aroylhydrazone ligand adopts different coordination modes in respective structures depending on the reaction conditions, as revealed by single-crystal X-ray analyses to be due to their tautomeric maneuver. The magnetic properties of 1-3 are drastically distinct. Compounds 1 and 2 show single-molecule-magnet behavior, while no out-of-phase alternating-current signal is noticed for 3. The structural differences induced by the different coordinate fashions of the ligand may influence the strength of the local crystal field, the magnetic interactions between metal centers, and the local tensor of anisotropy on each Dy site and their relative orientations, therefore generating dissimilar dynamic magnetic behavior.
RESUMO
Three new alkyl chain substituted complexes [Fe(H2Bpz2)2(Cn-bipy)] (pz = pyrazolyl, Cn-bipy = bipyridine alkyl chain diester, n = 3 (3), 4 (4) and 5 (5)) show versatile spin state switching behaviour with different "tail" lengths as revealed by structural and magnetic analyses. The most striking phenomenon is observed for 5 which undergoes an abrupt spin transition accompanied by thermal hysteresis of ca. 10 K, which is attributed to crystal packing effects derived from the competition between πâ¯π and C-Hâ¯O interactions. Interestingly, each of the complexes exhibits similar gradual and complete spin crossover in methanol solution with a transition temperature around 249 K, as deduced from temperature-dependent UV-vis spectroscopy. This highlights the differences between the solid state (ligand field; crystal packing) and solution (ligand field; solvation) effects on spin crossover. This work demonstrates that the length of the complex's alkyl chain substituents on the complex can have a large impact on the transition temperature and profile of solid state spin crossover, offering a potential path to the fabrication of soft matter spin crossover materials.
RESUMO
Two new dysprosium(III) coordination compounds, namely, [Dy(4)(HL)(4)(C(6)H(4)NH(2)COO)(2)(mu(3)-OH)(4)(mu-OH)(2)(H(2)O)(4)].4CH(3)CN.12H(2)O (1) and Dy(8)(HL)(10)(C(6)H(4)NH(2)COO)(2)(mu(3)-OH)(8)(OH)(2)(NO(3))(2)(H(2)O)(4)] (2), have been synthesized from the Schiff-base ligand 2-{[(2-hydroxy-3-methoxyphenyl)methylidene]amino}benzoic acid (H(2)L) and dysprosium chloride (1) or dysprosium nitrate (2). Single-crystal X-ray diffraction studies reveal that compound 1 exhibits a tetranuclear cubane-like structure and that 2 is an octanuclear, bis-cubane complex. The [Dy(4)(mu (3)-OH)(4)] cubane cores of 1 and 2 are structurally related; however, the magnetic properties of 1 and 2 are drastically different. Indeed, 2 shows slow relaxation of magnetization while no out-of-phase alternating current (ac) signal is noticed for 1. These significant disparities are most likely due to the different M-O-M angles observed for the respective cubane cores.
RESUMO
OBJECTIVE: To investigate the electrophysiological effects of ischemia/reperfusion (I/R) on the spontaneous slow response action potentials in guinea-pig left ventricular outflow tract and the effects of antiarrhythmic drugs onI/R. METHODS: The action potentials of pacemaker cells in guinea-pig left ventricular outflow tract were recorded by conventional intracellular microelectrode technique. The influences of ischemia(I) 10 min, reperfusion(R) 2 min, and R 15min on the spontaneous slow response potentials were investigated. The effects of lidocaine, propafenone, amiodarone, verapamil, adenosine, and sodium nitroprusside (SNP) on I/R were also studied. Electrophysiological parameters were examined:velocity of diastolic depolarization(VDD), rate of pacemaker firing(RPF), maximal diastolic potential(MDP), maximal rate of depolarization(Vmax), amplitude of action potential(APA), 50% and 90% of duration of action potential(APD50 and APD90). RESULTS: â In I 10 min group, the values of VDD, RPF, Vmax and APA were decreased markedly compared with control group (P<0.05, P<0.01).In R 2 min group, VDD and RPF were increased significantly(P<0.01), MDP was increased notably(P<0.05), APD50 and APD90 were shortened significantly compared with I 10 min and control group. Vmax was increased markedly vs control group(P<0.05). APA was decreased notably vs I 10 min group (P<0.05), but was increased markedly vs control group(P<0.05). In R 15 min group, the action potentials recovered gradually to the levels of control group. â¡ Compared with I 10 min/R 2 min group, 1 µmol/L lidocaine, 10 µmol/L propafenone, 1 µmol/L amiodarone, 1 µmol/L verapamil, 50 µmol/L adenosine, and 10 µmol/L SNP decreased VDD and RPF significantly. CONCLUSIONS: I/R injury can trigger abnormal spontaneous activities of guinea-pig left ventricular outflow tract.The electrophysiological effects of I/R injury on left ventricular outflow tract can be treated by antiarrhythmic drugs.
Assuntos
Potenciais de Ação , Antiarrítmicos/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Traumatismo por Reperfusão , Disfunção Ventricular Esquerda/tratamento farmacológico , Animais , Fenômenos Eletrofisiológicos , CobaiasRESUMO
Five dinuclear lanthanide complexes with formula [Ln2L2(OAc)4(MeOH)a(H2O)b] · cMeOH · dH2O (a = 2, b = 0, c = 2, d = 0, Ln = Sm (1), Gd (2), Dy (3); a = 0, b = 2, c = 4, d = 2, Ln = Tm (4)) and [Yb2L2(OAc)4(MeOH)2]·[Yb2L2(OAc)4(H2O)2] · 2H2O (5) (HL = (E)-N'-(2-hydroxybenzylidene)-2-mercaptonicotinohydrazide), have been synthesized and their crystal structures and magnetic properties are reported. All five complexes are centrosymmetric, showing a similar dinuclear core with two lanthanide ions in each complex being bridged by acetate groups in the η(1):η(2):µ2 mode. The various coordination modes of acetate groups result in two kinds of coordination geometries for Ln ions with the ones in complexes 1-4 and the Yb2 in 5 being nine-coordinated with a mono-capped square antiprism geometry, while the Yb1 ions in the other part of complex 5 are eight-coordinated with a triangular dodecahedron geometry. Magnetic susceptibility studies reveal that complex 3 shows single molecule magnet behaviour with an energy barrier of 39.1 K. In addition, comparison of the structural parameters among the similar Dy2 SMMs with a η(1):η(2):µ2 coordination mode of carboxylate groups reveals the significant role played by coordination geometry in modulating the relaxation dynamics of SMMs.