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1.
Anticancer Drugs ; 2020 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-31913197

RESUMO

OBJECTIVE: This multi-institutional study aimed to identify prognostic factors for cabazitaxel treatment of castration-resistant prostate cancer (CRPC). METHODS: This study included 74 Japanese patients with CRPC who were treated with cabazitaxel between 2014 and 2017. Associations between clinicopathological factors including serum markers and progression-free survival (PFS) and overall survival (OS) were investigated. RESULTS: On multivariate analysis, high Gleason score [≥9 vs. ≤7; hazard ratio (HR), 95% confidence interval (CI): 2.00 (1.01-4.34); P = 0.047], presence of pain [HR, 95% CI: 2.02 (1.14-3.58); P = 0.016], and lactate dehydrogenase (LDH) level [HR, 95% CI: 47.31 (3.79-577.49); P = 0.0019] were significantly associated with PFS. Similarly, number of docetaxel cycles [HR, 95% CI: 0.050 (0.0037-0.45); P = 0.0057], performance status [≥2 vs. 0; HR, 95% CI: 5.07 (1.57-16.24); P < 0.0001], and LDH level [HR, 95% CI: 2946 (50-420994); P = 0.0001] were significantly associated with OS. CONCLUSION: This study showed that LDH level is robustly prognostic for both PFS and OS in cabazitaxel chemotherapy for CRPC.

2.
Anticancer Res ; 40(1): 335-339, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31892584

RESUMO

BACKGROUND/AIM: The novel taxane cabazitaxel has been shown to exert excellent anticancer effects after androgen receptor axis-targeting (ARAT) agents in clinical data, but not in in vitro data. We investigated the clinical outcome of cabazitaxel chemotherapy after docetaxel according to use of ARAT agents. PATIENTS AND METHODS: Prostate specific antigen (PSA) response, progression-free survival, and overall survival were compared between cases with and without prior use of ARAT agents in 74 Japanese patients with metastatic castration-resistant prostate cancer treated with cabazitaxel chemotherapy. RESULTS: Background characteristics were comparable between patients with and without prior use of ARAT agents. PSA response, progression-free survival, and overall survival in cabazitaxel chemotherapy were comparable between patients with and without prior use of ARAT agents. CONCLUSION: No detrimental effects of prior ARAT agents on clinical outcome were observed for cabazitaxel chemotherapy in the post-docetaxel setting, suggesting that cabazitaxel can be expected to remain active even after ARAT agent therapy.


Assuntos
Antagonistas de Receptores de Andrógenos/farmacologia , Docetaxel/farmacologia , Terapia de Alvo Molecular , Receptores Androgênicos/metabolismo , Taxoides/farmacologia , Idoso , Antagonistas de Receptores de Andrógenos/uso terapêutico , Docetaxel/uso terapêutico , Humanos , Masculino , Prognóstico , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Taxoides/uso terapêutico , Resultado do Tratamento
3.
Anticancer Res ; 39(8): 4411-4414, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366538

RESUMO

BACKGROUND/AIM: Cabazitaxel use has usually been limited to up to 10 cycles in most countries according to the protocol in the TROPIC trial. Therefore, clinical data on cabazitaxel use beyond 10 cycles is limited. The aim of this study was to report the therapeutic outcome of cabazitaxel chemotherapy administered for >10 cycles. PATIENTS AND METHODS: This study included 74 Japanese patients with prostate cancer between 2014 and 2017. Patients background, and treatment outcomes including PSA decline, progression-free survival, treatment-failure-free survival, overall survival, and adverse events were investigated, comparing patients treated with ≤10 and >10 cycles. RESULTS: Patients characteristics were favorable as indicated by the higher number of cycles of prior docetaxel chemotherapy, absence of pain, and absence of bony and visceral metastases among men who received >10 cycles of cabazitaxel. PSA response, progression-free survival, treatment-failure-free survival and overall survival were better among patients treated with >10 cycles of cabazitaxel compared to those treated with ≤10 cycles. The incidence of severe adverse events was similar between the two groups. CONCLUSION: Taken together, this study suggested that continuous chemotherapy with cabazitaxel beyond 10 cycles may be beneficial.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Docetaxel/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Taxoides/administração & dosagem , Idoso , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Docetaxel/efeitos adversos , Esquema de Medicação , Humanos , Masculino , Pessoa de Meia-Idade , Intervalo Livre de Progressão , Antígeno Prostático Específico/sangue , Neoplasias de Próstata Resistentes à Castração/sangue , Neoplasias de Próstata Resistentes à Castração/patologia , Taxoides/efeitos adversos , Resultado do Tratamento
4.
Cancer Chemother Pharmacol ; 84(3): 561-566, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31115605

RESUMO

OBJECTIVE: This study aimed to reveal the efficacy and safety profiles of 4-weekly cabazitaxel in patients with castration-resistant prostate cancer (CRPC). METHODS: The study included 62 Japanese patients who were treated for CRPC with ≥ 2 courses of cabazitaxel between 2014 and 2017. The oncological outcomes and adverse events were compared between 16 (25.8%) and 46 (74.2%) men who were treated with standard 3-weekly and alternative 4-weekly regimens, respectively. RESULTS: The prostate-specific antigen (PSA) response was comparable between the 3-weekly and 4-weekly regimens (median [interquartile range]: - 9.9% [- 64.5 to 13.0%] and - 30.7% [- 52.8 to 10.9%], P = 0.89), respectively. For patients on the 4-weekly regimen, the risks of progression (hazard ratio [HR], 95% confidence interval [CI] 1.27, 0.71-2.43, P = 0.44), treatment failure (HR, 95% CI 0.84, 0.48-1.55, P = 0.57) and any-cause mortality (HR, 95% CI 1.09, 0.58-2.17, P = 0.79) were comparable to those for patients on the 3-weekly regimen. The incidences of severe adverse events were also similar between the 3-weekly and 4-weekly regimens. CONCLUSIONS: 3-weekly and 4-weekly regimens of cabazitaxel showed similar efficacy and safety profiles in a real-world clinical setting. These data suggest that a 4-weekly regimen may be acceptable for selected patients.

5.
Med Oncol ; 36(4): 32, 2019 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-30815799

RESUMO

This multi-institutional study aimed to investigate the efficacy and safety profiles of cabazitaxel after prior docetaxel chemotherapy in patients with castration-resistant prostate cancer (CRPC). This study included 63 Japanese patients with CRPC who were treated with cabazitaxel from 2014 to 2017. The oncological outcomes and adverse events (AEs) were documented, and prognostic factors for oncological outcomes and predictive factors for AEs were analysed. PSA decline was observed in 68.3% of patients, including 25.4% who achieved a ≥ 50% decline. The median progression-free survival, treatment failure-free survival, and overall survival were 4.3, 4.1, and 9.0 months, respectively. More cycles of prior docetaxel therapy was identified as common favourable prognostic factors for progression-free survival, treatment failure-free survival, and overall survival. Severe neutropenia, febrile neutropenia, and severe non-haematological AEs were observed in 73.0%, 33.3%, and 23.8% of patients, respectively. However, > 10 cycles of docetaxel was not associated with increased incidence of AEs. In conclusion, cabazitaxel chemotherapy was still active in Japanese CRPC patients treated with > 10 cycles of docetaxel chemotherapy, with an acceptable risk of AE burden. Treatment with cabazitaxel after > 10 cycles of docetaxel may be an appropriate option when it can be administered.


Assuntos
Docetaxel/administração & dosagem , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Taxoides/administração & dosagem , Taxoides/efeitos adversos , Idoso , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Esquema de Medicação , Humanos , Masculino , Resultado do Tratamento
6.
J Phys Condens Matter ; 31(22): 223001, 2019 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-30822763

RESUMO

Thanks to advances in in situ measurement techniques for electrical transport in ultra-high vacuum together with emergent materials such as Rashba-type surfaces, topological insulators, atomic-layer superconductors, and 2D materials like graphene, surface states and edge states on crystals provide intriguing topics, e.g. dissipation-less currents, spin-polarized electric current, and pure spin current. This is due to broken symmetry and strong spin-orbit and electron-phonon interactions. Here we review some examples of experimental techniques of multi-probe methods at macroscopic and microscopic scales, followed by transport phenomena revealed by them. These are opening a field in condensed matter physics driven by symmetry breaking at surfaces and atomic layers.

7.
Nihon Hinyokika Gakkai Zasshi ; 110(1): 32-35, 2019.
Artigo em Japonês | MEDLINE | ID: mdl-31956216

RESUMO

A 70-year-old woman, with an 8 cm tumor in the left kidney and multiple lung tumor and was diagnosed with Renal Cell Carcinoma (cT3aN0M1). The kidney tumor were unresectable and we started treatment with Tyrosine Kinase Inhibitors (sunitinib, pazopanib, axitinib, temsirolimus), but they failed because of disease progression or adverse events. We used nivolumab for 5th line treatment; then, interstitial pneumonia was observed. The renal tumor shrunk and pulmonary metastatic foci revealed prominent disappearance. The renal tumor became resectable and we tried nephrectomy. Pathological findings were clear cell carcinoma with marked necrosis, hyperplasia and internal bleeding.

8.
J Phys Condens Matter ; 30(26): 265001, 2018 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-29770777

RESUMO

We show Shubnikov-de Haas (SdH) oscillations in topological insulator (Bi x Sb1-x )2Te3 flakes whose carrier types are p-type (x = 0.29, 0.34) and n-type (x = 0.42). The physical properties such as the Berry phase, carrier mobility, and scattering time significantly changed by tuning the Fermi-level position with the concentration x. The analyses of SdH oscillations by Landau-level fan diagram, Lifshitz-Kosevich theory, and Dingle-plot in the p-type samples with x = 0.29 and 0.34 showed the Berry phase of zero and a relatively low mobility (2000-6000 cm2 V-1 s-1). This is due to the dominant bulk component in transport. On the other hand, the mobility in the n-type sample with x = 0.42 reached a very large value ~17 000 cm2 V-1 s-1 and the Berry phase of near π, whereas the SdH oscillations were neither purely two- nor three-dimensional. These suggest that the transport channel has a surface-bulk coupling state which makes the carrier scattering lesser and enhances the mobility and has a character between two- and three-dimension.

9.
Nano Lett ; 17(6): 3493-3500, 2017 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-28545300

RESUMO

Inducing magnetism into topological insulators is intriguing for utilizing exotic phenomena such as the quantum anomalous Hall effect (QAHE) for technological applications. While most studies have focused on doping magnetic impurities to open a gap at the surface-state Dirac point, many undesirable effects have been reported to appear in some cases that makes it difficult to determine whether the gap opening is due to the time-reversal symmetry breaking or not. Furthermore, the realization of the QAHE has been limited to low temperatures. Here we have succeeded in generating a massive Dirac cone in a MnBi2Se4/Bi2Se3 heterostructure, which was fabricated by self-assembling a MnBi2Se4 layer on top of the Bi2Se3 surface as a result of the codeposition of Mn and Se. Our experimental results, supported by relativistic ab initio calculations, demonstrate that the fabricated MnBi2Se4/Bi2Se3 heterostructure shows ferromagnetism up to room temperature and a clear Dirac cone gap opening of ∼100 meV without any other significant changes in the rest of the band structure. It can be considered as a result of the direct interaction of the surface Dirac cone and the magnetic layer rather than a magnetic proximity effect. This spontaneously formed self-assembled heterostructure with a massive Dirac spectrum, characterized by a nontrivial Chern number C = -1, has a potential to realize the QAHE at significantly higher temperatures than reported up to now and can serve as a platform for developing future "topotronics" devices.

10.
ACS Nano ; 10(2): 2761-5, 2016 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-26815333

RESUMO

We report the direct evidence for superconductivity in Ca-intercalated bilayer graphene C6CaC6, which is regarded as the thinnest limit of Ca-intercalated graphite. We performed the electrical transport measurements with the in situ 4-point-probe method in ultrahigh vacuum under zero- or nonzero-magnetic field for pristine bilayer graphene, Li-intercalated bilayer graphene (C6LiC6) and C6CaC6 fabricated on SiC substrate. We observed that the zero-resistance state occurs in C6CaC6 with the onset temperature (T(c)(onset)) of 4 K, while the T(c)(onset) is gradually decreased upon applying the magnetic field. This directly proves the superconductivity origin of the zero resistance in C6CaC6. On the other hand, both pristine bilayer graphene and C6LiC6 exhibit nonsuperconducting behavior, suggesting the importance of intercalated atoms and its species to drive the superconductivity.

11.
Phys Rev Lett ; 113(20): 206802, 2014 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-25432051

RESUMO

We performed in situ magnetotransport measurements on ultrathin Bi(111) films [4-30 bilayers (BLs), 16-120 Å thick] to elucidate the role of bulk or surface states in the transport phenomena. We found that the temperature dependence of the film conductivity shows no thickness dependence for the 6-16 BL films and is affected by the electron-electron scattering, suggesting surface-state dominant contribution. In contrast, the weak antilocalization effect observed by applying a magnetic field shows clear thickness dependence, indicating bulk transport. This apparent inconsistency is explained by a coherent bulk-surface coupling that produces a single channel transport. For the films thicker than 20 BLs, the behavior changes drastically which can likely be interpreted as a bulk dominant conduction.

12.
J Am Chem Soc ; 136(41): 14357-60, 2014 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-25251306

RESUMO

A bulk material comprising stacked nanosheets of nickel bis(dithiolene) complexes is investigated. The average oxidation number is -3/4 for each complex unit in the as-prepared sample; oxidation or reduction respectively can change this to 0 or -1. Refined electrical conductivity measurement, involving a single microflake sample being subjected to the van der Pauw method under scanning electron microscopy control, reveals a conductivity of 1.6 × 10(2) S cm(-1), which is remarkably high for a coordination polymeric material. Conductivity is also noted to modulate with the change of oxidation state. Theoretical calculation and photoelectron emission spectroscopy reveal the stacked nanosheets to have a metallic nature. This work provides a foothold for the development of the first organic-based two-dimensional topological insulator, which will require the precise control of the oxidation state in the single-layer nickel bisdithiolene complex nanosheet (cf. Liu, F. et al. Nano Lett. 2013, 13, 2842).

13.
Phys Rev Lett ; 110(23): 237001, 2013 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-25167523

RESUMO

In situ micro-four-point-probe conductivity measurements in ultrahigh vacuum revealed that the Si(111)-striped incommensurate-Pb surface showed the superconductivity transition at 1.1 K. Both of the hexagonal and rectangular phases of Si(111)√[7]×√[3]-In surface showed superconductivity at 2.4 and 2.8 K, respectively. By applying magnetic field perpendicular to the surface, the upper critical field was deduced to be 0.1-1 T. The derived Ginzburg-Landau coherence length of the Cooper pairs was several tens of nm, which was much smaller than the Pippard's coherence length estimated from the band structures. The short coherence length is determined by the carrier mean free path.

14.
Phys Rev Lett ; 107(16): 166801, 2011 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-22107414

RESUMO

We report the formation of a bilayer Bi(111) ultrathin film, which is theoretically predicted to be in a two-dimensional quantum spin Hall state, on a Bi(2)Te(3) substrate. From angle-resolved photoemission spectroscopy measurements and ab initio calculations, the electronic structure of the system can be understood as an overlap of the band dispersions of bilayer Bi and Bi(2)Te(3). Our results show that the Dirac cone is actually robust against nonmagnetic perturbations and imply a unique situation where the topologically protected one- and two-dimensional edge states are coexisting at the surface.

15.
Phys Rev Lett ; 106(11): 116802, 2011 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-21469886

RESUMO

We have succeeded in detecting metallic transport in a monatomic layer of In on an Si(111) surface, Si(111)-sqrt[7]×sqrt[3]-In surface reconstruction, using the micro-four-point probe method. The In layer exhibited conductivity higher than the minimum metallic conductivity (the Ioffe-Regel criterion) and kept the metallic temperature dependence of resistivity down to 10 K. This is the first example of a monatomic layer, with the exception of graphene, showing metallic transport without carrier localization at cryogenic temperatures. By introducing defects on this surface, a metal-insulator transition occurred due to Anderson localization, showing hopping conduction.

16.
J Phys Condens Matter ; 22(8): 084026, 2010 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-21389402

RESUMO

Several examples are known in which massive arrays of metal atomic chains are formed on semiconductor surfaces that show quasi-one-dimensional metallic electronic structures. In this review, Au chains on Si(557) and Si(553) surfaces, and In chains on Si(111) surfaces, are introduced and discussed with regard to the physical properties determined by experimental data from scanning tunneling microscopy (STM), angle-resolved photoemission spectroscopy (ARPES) and electrical conductivity measurements. They show quasi-one-dimensional Fermi surfaces and parabolic band dispersion along the chains. All of them are known from STM and ARPES to exhibit metal-insulator transitions by cooling and charge-density-wave formation due to Peierls instability of the metallic chains. The electrical conductivity, however, reveals the metal-insulator transition only on the less-defective surfaces (Si(553)-Au and Si(111)-In), but not on a more-defective surface (Si(557)-Au). The latter shows an insulating character over the whole temperature range. Compared with the electronic structure (Fermi surfaces and band dispersions), the transport property is more sensitive to the defects. With an increase in defect density, the conductivity only along the metal atomic chains was significantly reduced, showing that atomic-scale point defects decisively interrupt the electrical transport along the atomic chains and hide the intrinsic property of transport in quasi-one-dimensional systems.

17.
Phys Rev Lett ; 101(10): 107604, 2008 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-18851258

RESUMO

The electronic structure of Ag(111) quantum well films covered with a (sqrt[3]xsqrt[3]) R30 degrees Bi/Ag surface ordered alloy, which shows a Rashba spin-split surface state, is investigated with angle-resolved photoemission spectroscopy. The band dispersion of the spin-split surface state is significantly modified by the interaction with the quantum well states of Ag films. The interaction is well described by the band hybridization model, which concludes the spin polarization of the quantum well states.

18.
Phys Rev Lett ; 99(14): 146805, 2007 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-17930700

RESUMO

Temperature-dependent electron transport in a metallic surface superstructure, Si(111)sqrt[3] x sqrt[3]-Ag, was studied by a micro-four-point probe method and photoemission spectroscopy. The surface-state conductivity exhibits a sharp transition from metallic conduction to strong localization at approximately 150 K. The metallic regime is due to electron-phonon interaction while the localization seemingly originates from coherency of electron waves. Random potential variations, caused by Friedel oscillations of surface electrons around defects, likely induce strong carrier localization.

19.
Phys Rev Lett ; 98(24): 247601, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17677992

RESUMO

We report the energy dispersions of the highest occupied molecular orbitals (HOMO)-derived bands of a pentacene (Pn) thin film, whose in-plane structure resembles closely that of the ab plane of a low-density bulk Pn phase. Our present photoemission result indicates that the overlap of the pi-orbitals of adjacent Pn molecules is larger than what was expected from theoretical calculations. Further, of the two HOMO-derived bands, the large dispersion width of the band with higher binding energy suggests that this one mainly contributes to the bandlike charge transport in a Pn crystal.

20.
Rev Sci Instrum ; 78(5): 053705, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17552823

RESUMO

The authors have developed an ultrahigh vacuum (UHV) variable-temperature four-tip scanning tunneling microscope (STM), operating from room temperature down to 7 K, combined with a scanning electron microscope (SEM). Four STM tips are mechanically and electrically independent and capable of positioning in arbitrary configurations in nanometer precision. An integrated controller system for both of the multitip STM and SEM with a single computer has also been developed, which enables the four tips to operate either for STM imaging independently and for four-point probe (4PP) conductivity measurements cooperatively. Atomic-resolution STM images of graphite were obtained simultaneously by the four tips. Conductivity measurements by 4PP method were also performed at various temperatures with the four tips in square arrangement with direct contact to the sample surface.


Assuntos
Aumento da Imagem/instrumentação , Interpretação de Imagem Assistida por Computador/instrumentação , Interpretação de Imagem Assistida por Computador/métodos , Microscopia de Tunelamento/instrumentação , Transdutores , Desenho de Equipamento , Análise de Falha de Equipamento , Aumento da Imagem/métodos , Microscopia de Tunelamento/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Temperatura Ambiente
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