Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 38
Filtrar
Mais filtros












Base de dados
Intervalo de ano de publicação
1.
Small ; 19(32): e2301966, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37178437

RESUMO

The combination of single-ion magnets (SIMs) and metal-organic frameworks (MOFs) is expected to produce new quantum materials. The principal issue to be solved in this regard is the development of new strategies for the synthesis of SIM-MOFs. This work demonstrates a new simple strategy for the synthesis of SIM-MOFs where a diamagnetic MOF is used as the framework into which the SIM sites are doped. 1, 0.5, and 0.2 mol% of the Co(II) ions are doped into the Zn(II) sites of [CH6 N3 ][ZnII (HCOO)3 ]. The doped Co(II) sites in the MOFs perform as SIM with a positive D term of zero-field splitting. The longest magnetic relaxation time is 150 ms (0.2 mol% Co) at 1.8 K under a static field of 0.1 T. Temperature dependency of the relaxation time suggests suppressing magnetic relaxation by reduction of spin-spin interaction upon doping in the rigid framework. Thus, this work represents a proof of concept for the creation of a single-ion doped magnet in the MOF. This simple synthetic strategy will be widely applied for the creation of quantum magnetic materials.

2.
Angew Chem Int Ed Engl ; 62(12): e202300437, 2023 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-36723446

RESUMO

NiII 3,7,13,17-tetrapyridyl-5,15-diazaporphyrin serves as a double tridentate ligand to PdII ions to provide a pincer-type bispalladium complex. Electrochemical analysis revealed that the bispalladium complex shows excellent ability to accept electrons and reversible redox properties due to the coordination of the two cationic PdII centers to the meso-nitrogen atoms. We isolated and characterized one- and two-electron reduction species of the bispalladium complex. The 20π antiaromatic nature of the two-electron reduction species was confirmed by 1 H NMR spectroscopy, UV/Vis-near-IR (NIR) absorption spectra, and density functional theory (DFT) calculations. X-ray diffraction revealed highly twisted structures for the bispalladium complexes regardless of the oxidation state.

3.
Respir Med Case Rep ; 40: 101781, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36408483

RESUMO

A 55-year-old man experienced nausea and vomiting after brushing his teeth. He experienced back pain after this episode and visited our emergency department. Chest computed tomography (CT) images revealed moderate pleural fluid accumulation and mild left pneumothorax. Thoracentesis showed black pleural effusion. Thoracic drainage included food debris with black pleural effusion, and gastroscopy revealed food debris and perforation of the lower esophagus. Esophageal perforation was surgically repaired using omental implantation and pleuroclysis. Given the high mortality rate associated with black pleural effusion, prompt diagnostic procedures and corresponding management are essential.

4.
Inorg Chem ; 61(35): 14067-14074, 2022 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-36006962

RESUMO

In condensed matter, phase separation is strongly related to ferroelasticity, ferroelectricity, ferromagnetism, electron correlation, and crystallography. These ferroics are important for nano-electronic devices such as non-volatile memory. However, the quantitative information regarding the lattice (atomic) structure at the border of phase separation is unclear in many cases. Thus, to design electronic devices at the molecular level, a quantitative electron-lattice relationship must be established. Herein, we elucidated a PdII-PdIV/PdIII-PdIII phase transition and phase separation mechanism for [Pd(cptn)2Br]Br2 (cptn = 1R,2R-diaminocyclopentane), propagated through a hydrogen-bonding network. Although the Pd···Pd distance was used to determine the electronic state, the differences in the Pd···Pd distance and the optical gap between Mott-Hubbard (MH) and charge-density-wave (CDW) states were only 0.012 Å and 0.17 eV, respectively. The N-H···Br···H-N hydrogen-bonding network functioned as a jack, adjusting the structural difference dynamically, and allowing visible ferroelastic phase transition/separation in a fluctuating N2 gas flow. Additionally, the effect of the phase separation on the spin susceptibility and electrical conductivity were clarified to represent the quasi-epitaxial crystals among CDW-MH states. These results indicate that the phase transitions and separations could be controlled via atomic and molecular level modifications, such as the addition of hydrogen bonding.

5.
Inorg Chem ; 61(25): 9504-9513, 2022 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-35695034

RESUMO

Halogen-bridged linear chain metal complexes (MX-Chains) are fascinating compounds that have a quasi-one-dimensional (1D) electronic system. In this study, we synthesized the first Ni-based MX-Chain compound having hydroxy groups, i.e., [Ni(dabdOH)2Br]Br2·[Ni(dabdOHx)2Br]0.5·(2-PrOH)0.25·(MeOH)0.25 (1·solvent, x = ∼0.6, dabdOH = (2S,3S)-2,3-diaminobutane-1,4-diol). Single-crystal X-ray diffraction revealed that the MX-Chains in 1·solvent formed sheets and single-chain structures in the superlattice. It suggested an MH-like state, whereas the polarized reflection and Raman spectra suggested a CDW-like state. Magnetic and electron spin resonance measurements revealed that both high-spin Ni(II) (∼15%) and low-spin Ni(III) (∼85%) sites are present in the chain structures, i.e., the metal sites show mixed valency. Therefore, we concluded that 1·solvent adopts an intermediate state between the MH and CDW states. Moreover, a single crystal of 1·solvent exhibited semiconductive characteristics along the chain direction. This finding represents a new structural and electronic state of 1D electronic systems as well as MX-Chains.

6.
Intern Med ; 60(19): 3101-3105, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33840698

RESUMO

We herein report the first case of low-dose oxygen therapy for pneumatosis cystoides intestinalis (PCI) using PaO2 as a therapeutic index to prevent acute exacerbation of interstitial pneumonia. An 86-year-old man was admitted to our hospital with abdominal distension. PCI was diagnosed by abdominal computed tomography. Low-dose oxygen therapy was started to avoid acute exacerbation of interstitial pneumonia. The oxygen dose was adjusted so that the PaO2 value was approximately 100 mmHg. After seven days of treatment, the colon gas had disappeared, and no acute exacerbation of interstitial pneumonia was observed. A PaO2 value around 100 mmHg is effective for PCI without inducing acute exacerbation of interstitial pneumonia.


Assuntos
Doenças Pulmonares Intersticiais , Pneumatose Cistoide Intestinal , Idoso de 80 Anos ou mais , Colo , Humanos , Doenças Pulmonares Intersticiais/diagnóstico por imagem , Doenças Pulmonares Intersticiais/terapia , Masculino , Oxigênio , Oxigenoterapia , Pneumatose Cistoide Intestinal/diagnóstico por imagem
7.
Intern Med ; 60(15): 2465-2468, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33678738

RESUMO

We experienced a case of the successful treatment of intractable pulmonary aspergillosis with inhaled liposomal amphotericin B (L-AMB) and oral voriconazole (VRCZ). A 52-year-old man was admitted to our hospital with a fever. Chest computed tomography (CT) revealed an infiltrative shadow. Two separate sputum cultures detected Aspergillus niger. Although we treated the patient with single and combined antifungal agents, the infiltrative shadow worsened. After obtaining sufficient informed consent from the patient, we switched him to an inhaled L-AMB. The infiltrative shadow subsequently improved. The patient has remained well for one year without exacerbation. We herein report the usefulness of inhaled L-AMB and oral VRCZ.


Assuntos
Antifúngicos , Aspergilose Pulmonar , Anfotericina B , Antifúngicos/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Aspergilose Pulmonar/diagnóstico por imagem , Aspergilose Pulmonar/tratamento farmacológico , Voriconazol
8.
Dalton Trans ; 50(5): 1614-1619, 2021 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-33332512

RESUMO

The Pd(iii) oxidation state is unusual and unstable since it strongly tends to disproportionate. We synthesized the quasi-one-dimensional (1D) halogen-bridged Pd(iii)-Cl complex [Pd(dabdOH)2Cl]Cl2 (1-Cl; dabdOH = (2S,3S)-2,3-diaminobutane-1,4-diol) with multiple hydrogen bonds. From single-crystal X-ray diffraction, the bridging Cl- ions were located at the midpoint of the Pd-Cl-Pd moieties in the 1D chains, indicating that the Pd ions are in a Pd(iii) average valence (AV) state. Moreover, bright spots for the Pd(iii) dz2 orbitals in the upper Hubbard band above the Fermi level were observed every ∼5 Šusing scanning tunnelling microscopy. These results clearly indicate that the Pd ions are in a Pd(iii) AV state in 1-Cl. In addition, 1-Cl has the highest thermal stability (470 K) among the Pd(iii) complexes reported and the highest electrical conductivity (0.6 S cm-1 at 300 K) among the 1D Pd-Cl chains reported so far.

9.
Intern Med ; 60(5): 783-788, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33229802

RESUMO

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive hereditary disease that may be complicated by progressive and potentially fatal interstitial pneumonia. We herein report a 64-year-old woman with interstitial pneumonia associated with HPS type 4 whom we treated with nintedanib after pirfenidone proved ineffective. To our knowledge, there have been no previous reports of nintedanib being used to treat a patient with HPS type 4. There is a need for clinical trials of antifibrotic agents, including nintedanib, pirfenidone, and new therapeutic agents with different mechanisms of action in these patients.


Assuntos
Síndrome de Hermanski-Pudlak , Doenças Pulmonares Intersticiais , Fibrose Pulmonar , Feminino , Humanos , Doenças Pulmonares Intersticiais/tratamento farmacológico , Doenças Pulmonares Intersticiais/etiologia , Pessoa de Meia-Idade , Fibrose Pulmonar/tratamento farmacológico , Fibrose Pulmonar/etiologia
10.
Sci Adv ; 6(7): eaay8065, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32110735

RESUMO

Conducting polymer thin films containing inherent structural disorder exhibit complicated electronic, transport, and thermoelectric properties. The unconventional power-law relation between the Seebeck coefficient (S) and the electrical conductivity (σ) is one of the typical consequences of this disorder, where no maximum of the thermoelectric power factor (P = S 2σ) has been observed upon doping, unlike conventional systems. Here, it is demonstrated that a thiophene-based semicrystalline polymer exhibits a clear maximum of P through wide-range carrier doping by the electrolyte gating technique. The maximum value appears around the macroscopic insulator-to-metal transition upon doping, which is firmly confirmed by the temperature dependence of σ and magnetoresistance measurements. The effect of disorder on charge transport is suppressed in the metallic state, resulting in the conventional S-σ relation described by the Mott equation. The present results provide a physical background for controlling the performance of conducting polymers toward the application to thermoelectric devices.

11.
Lung Cancer ; 132: 54-58, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31097094

RESUMO

BACKGROUND: Osimertinib is a tyrosine kinase inhibitor (TKI) that is an essential agent for the treatment of epidermal growth factor receptor (EGFR)-mutant non-small-cell lung cancer (NSCLC). However, there is no established strategy for treatment following acquired resistance to this agent. One potential strategy for treating acquired resistance to EGFR TKIs is re-administration, which has been evaluated mainly using first- or second-generation EGFR TKIs. However, no clinical data are available with which to determine the significance of re-administration of osimertinib, a third-generation EGFR TKI. The aim of this study was to evaluate the efficacy of re-administering osimertinib to patients who had acquired resistance to this agent. PATIENTS AND METHODS: We reviewed the medical records of consecutive patients with advanced NSCLC harboring EGFR-activating mutations and secondary T790M, who had undergone osimertinib re-administration to treat acquired resistance. RESULTS: Seventeen patients were re-administered osimertinib after acquiring resistance to osimertinib. Of these, two received osimertinib to treat carcinomatous meningitis without any measurable lesion. Responses were evaluated in the remaining 15 patients. The objective response and disease control rates were 33% and 73%, respectively. Tumor shrinkage by osimertinib re-administration was associated with that due to initial osimertinib treatment (r = 0.585, 95% confidence interval [CI]: 0.104-0.844). In the remaining two patients without measurable lesions, one exhibited improved clinical symptoms following osimertinib re-administration. The median progression-free survival (PFS) time of all 17 patients was 4.1 months (95% CI: 1.9-6.7). The toxicity of re-administration was low, without interruption of the treatment due to adverse events (AEs). Most patients had grade 2 AEs or lower. CONCLUSIONS: Re-administration of osimertinib for EGFR-mutant NSCLC yielded modest activity with tolerable toxicity.


Assuntos
Acrilamidas/uso terapêutico , Compostos de Anilina/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Adulto , Idoso , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Feminino , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Mutação/genética , Estadiamento de Neoplasias , Análise de Sobrevida
12.
Entropy (Basel) ; 21(6)2019 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-33267263

RESUMO

The well-known Hölder's inequality has been recently utilized as an essential tool for solving several optimization problems. However, such an essential role of Hölder's inequality does not seem to have been reported in the context of generalized entropy, including Rényi-Tsallis entropy. Here, we identify a direct link between Rényi-Tsallis entropy and Hölder's inequality. Specifically, we demonstrate yet another elegant proof of the Rényi-Tsallis entropy maximization problem. Especially for the Tsallis entropy maximization problem, only with the equality condition of Hölder's inequality is the q-Gaussian distribution uniquely specified and also proved to be optimal.

13.
Nat Commun ; 8: 15200, 2017 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-28492241

RESUMO

The control of spins and spin to charge conversion in organics requires understanding the molecular spin-orbit coupling (SOC), and a means to tune its strength. However, quantifying SOC strengths indirectly through spin relaxation effects has proven difficult due to competing relaxation mechanisms. Here we present a systematic study of the g-tensor shift in molecular semiconductors and link it directly to the SOC strength in a series of high-mobility molecular semiconductors with strong potential for future devices. The results demonstrate a rich variability of the molecular g-shifts with the effective SOC, depending on subtle aspects of molecular composition and structure. We correlate the above g-shifts to spin-lattice relaxation times over four orders of magnitude, from 200 to 0.15 µs, for isolated molecules in solution and relate our findings for isolated molecules in solution to the spin relaxation mechanisms that are likely to be relevant in solid state systems.

14.
J Am Chem Soc ; 139(19): 6562-6565, 2017 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-28467845

RESUMO

A Br-bridged Pd chain complex with the Pd ion in an uncommon +3 oxidation state, [Pd(dabdOH)2Br]Br2 (3), was prepared using a new method involving multiple hydrogen bonds. The PdBr chain complex exhibited superior electrical conductivity and thermal stability. An in-plane ligand with an additional hydrogen donor group (hydroxy group), (2S,3S)-2,3-diaminobutane-1,4-diol (dabdOH), was used to create a multiple-hydrogen-bond network, which effectively shrinks the Pd-Br-Pd distance, stabilizing the Pd(III) state up to its decomposition temperature (443 K). 3 shows semiconducting behavior with quite high electrical conductivity (3-38 S cm-1 at room temperature), which is 106 times larger than the previous record for analogous PdBr chains. Indeed, 3 is the most conductive MX-type chain complex reported so far. The precise positional control of ions via a multiple-hydrogen-bond network is a useful method for controlling the electronic states, thermal stability and conductivity of linear coordination polymers.

15.
Adv Mater ; 29(18)2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28262982

RESUMO

Ions and electrons in blends of polymer-electrolyte can work in ensemble to operate light-emitting electrochemical cells (LECs), in which the unique features of in situ formed p-n homojunctions offer efficient charge injection and transport. However, electrochemical features give rise to significant stability and speed issues due to limited electrochemical stability and low ion mobility, resulting in low brightness and a slow response of LECs. Here, these issues are overcome by the separate control of ionic and electronic charges, using a simple driving pulse superimposed on a small base voltage; ions with slow response are rearranged by a constant base voltage, while a high-voltage pulse, superimposed upon the base, injects electrons/holes which have fast response, with minimal effect on the ions. This scheme successfully injects an extremely high current density of > 2 kA cm-2 with a balanced electron/hole ratio, at a high-speed response time of ≈ 50 ns; both properties demonstrate advantages of LECs in making polymers brighter. An in situ electron spin resonance measurement on the LECs further revealed that this impressive performance is due to the highly doped polymers, whose spin density reached 7 × 1019 spins cm-3 , and an ordered polymer structure in the active layer blend.

16.
Clin Lung Cancer ; 18(2): 245-249, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27847247

RESUMO

Concurrent chemoradiotherapy (CRT) is the standard of care for locally advanced non-small cell lung cancer (LA-NSCLC). However, this intensive therapy often causes severe esophagitis, which could deteriorate a patient's quality of life (QOL), leading to poor treatment compliance. Sodium alginate, approved in Japan for gastritis, is sufficiently highly viscous to remain in the esophageal mucosa, providing a protective effect in the esophagus. To investigate whether this compound has a preventive effect against severe esophagitis in patients receiving concurrent CRT, we plan a 3-arm randomized trial of sodium alginate with 2 different schedules versus water. The primary endpoint is set as the proportion of patients with grade ≥ 3 esophagitis using the Common Terminology Criteria for Adverse Events, version 4.0. With stratification by institute, performance status, and percentage of the esophageal volume receiving >35 Gy, the patients will be randomly assigned to 1 of the following groups: sodium alginate initiated concomitantly with CRT (group A), sodium alginate initiated soon after the development of extremely mild esophagitis during CRT (group B), or water administered throughout CRT (group C). Assuming that the proportion of grade ≥ 3 esophagitis would be 8% in groups A and B and 27% in group C, the required sample size would be 200 patients, with 70% power and 5% α. The secondary endpoints include QOL, the frequency of additional prescriptions of analgesics, treatment response, and survival. The results of the present study will clarify whether sodium alginate can prevent esophagitis in patients with LA-NSCLC undergoing CRT.


Assuntos
Alginatos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/terapia , Quimiorradioterapia/efeitos adversos , Esofagite/tratamento farmacológico , Neoplasias Pulmonares/terapia , Lesões por Radiação/tratamento farmacológico , Protetores contra Radiação/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/patologia , Esofagite/etiologia , Feminino , Seguimentos , Ácido Glucurônico/uso terapêutico , Ácidos Hexurônicos/uso terapêutico , Humanos , Japão , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Lesões por Radiação/etiologia , Dosagem Radioterapêutica , Adulto Jovem
17.
Nat Mater ; 15(8): 896-902, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27159015

RESUMO

Doping is one of the most important methods to control charge carrier concentration in semiconductors. Ideally, the introduction of dopants should not perturb the ordered microstructure of the semiconducting host. In some systems, such as modulation-doped inorganic semiconductors or molecular charge transfer crystals, this can be achieved by spatially separating the dopants from the charge transport pathways. However, in conducting polymers, dopants tend to be randomly distributed within the conjugated polymer, and as a result the transport properties are strongly affected by the resulting structural and electronic disorder. Here, we show that in the highly ordered lamellar microstructure of a regioregular thiophene-based conjugated polymer, a small-molecule p-type dopant can be incorporated by solid state diffusion into the layers of solubilizing side chains without disrupting the conjugated layers. In contrast to more disordered systems, this allows us to observe coherent, free-electron-like charge transport properties, including a nearly ideal Hall effect in a wide temperature range, a positive magnetoconductance due to weak localization and the Pauli paramagnetic spin susceptibility.

18.
Chem Commun (Camb) ; 50(61): 8382-4, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-24944025

RESUMO

We synthesized and characterized bromide-bridged Pd(III) chain complexes, [Pd(en)2Br](MalCn-Y)2·H2O (en = ethylenediamine; MalCn-Y = dialkyl sulfomalonate; n: the number of carbon atoms) (n = 7 and 12). The compound with n = 7 showed charge-bistability near room temperature. In addition, it is shown that the Pd(III) state is maintained in the thin film state.

19.
Dalton Trans ; 43(30): 11529-32, 2014 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-24869914

RESUMO

We report an unusual magnetic anisotropy in a S = 1/2 1D antiferromagnetic (AF) compound CuCl2(pdz) (pdz = pyridazine). The magnetic susceptibility for H//a* and H//c showed characteristic behavior in the S = 1/2 1D Heisenberg AF system, whereas that for H//b exhibited a 1/T contribution. The origin of such an anomalous anisotropy in the magnetic susceptibility is explained by the staggered g-tensor of this compound.

20.
Adv Mater ; 26(15): 2376-83, 2014 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-24327521

RESUMO

Fluoroalkylsilane (FTS) acts as an efficient p-type dopant for organic semiconductors. FTS-doped films of the semicrystalline PBTTT polymer exhibit relatively high conductivities. We demonstrate that highly doped PBTTT films exhibit a metallic nature with clear Pauli paramagnetism as observed microscopically using electron spin resonance spectroscopy. The metallic state is realized within crystalline grains, as confirmed from the anisotropy of the ESR signal.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...