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










Base de dados
Intervalo de ano de publicação
1.
Clin Mol Hepatol ; 29(2): 433-452, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36597018

RESUMO

BACKGROUND/AIMS: Global distribution of dominant liver cancer aetiologies has significantly changed over the past decades. This study analyzed the updated temporal trends of liver cancer aetiologies and sociodemographic status in 204 countries and territories from 1990 to 2019. METHODS: The Global Burden of Disease 2019 report was used for statistical analysis. In addition, we performed stratification analysis to five quintiles using sociodemographic index and 21 geographic regions. RESULTS: The crude numbers of liver cancer disease-adjusted life years (DALYs) and deaths significantly increased during the study period (DALYs; 11,278,630 in 1990 and 12,528,422 in 2019, deaths; 365,215 in 1990 and 484,577 in 2019). However, the Age-standardized DALY and mortality rates decreased. Hepatitis B virus (HBV) remains the leading cause of liver cancer DALYs and mortality, followed by hepatitis C virus (HCV), alcohol consumption, and non-alcoholic steatohepatitis/non-alcoholic fatty liver disease (NASH/NAFLD). Although Age-standardized DALY and mortality rates of liver cancer due to HBV and HCV have decreased, the rates due to alcohol consumption and NASH/NAFLD have increased. In 2019, the population of the East Asia region had the highest Age-standardized DALY and mortality rates, followed by high-income Asia-Pacific and Central Asia populations. Although East Asia and high-income Asia-Pacific regions showed a decrease during the study period, Age-standardized DALY rates increased in Central Asia. High-income North American and Australasian populations also showed a significant increase in Age-standardized DALY. CONCLUSION: Liver cancer remains an ongoing global threat. The burden of liver cancer associated with alcohol consumption and NASH/NAFLD is markedly increasing and projected to continuously increase.


Assuntos
Hepatite C , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Humanos , Masculino , Feminino , Anos de Vida Ajustados por Qualidade de Vida , Hepatopatia Gordurosa não Alcoólica/complicações , Hepatopatia Gordurosa não Alcoólica/diagnóstico , Hepatopatia Gordurosa não Alcoólica/epidemiologia , Carga Global da Doença , Caracteres Sexuais , Hepatite C/complicações , Hepatite C/epidemiologia , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/etiologia , Incidência
2.
Phys Chem Chem Phys ; 24(44): 27483-27494, 2022 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-36342315

RESUMO

We investigate photoelectron circular dichroism (PECD) with coherent light sources whose pulse durations range from femtoseconds to nanoseconds. To that end, we employed an optical parametric amplifier, an ultraviolet optical pulse shaper, and a nanosecond dye laser, all centered around a wavelength of 380 nm. A multiphoton ionization experiment on the gas-phase chiral prototype fenchone found that PECD measured via the 3s intermediate resonance is about 15% and robust over five orders of magnitude of the pulse duration. PECD remains robust despite ongoing molecular dynamics such as rotation, vibration, and internal conversion. We used the Lindblad equation to model the molecular dynamics. Under the assumption of a cascading internal conversion, from the 3p to the 3s and further to the ground state, we estimated the lifetimes of the internal conversion processes in the 100 fs regime.

3.
Plants (Basel) ; 11(14)2022 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-35890478

RESUMO

The objectives of this research were to evaluate the policosanol profiles and adenosine-5'-monophosphate-activated protein kinase (AMPK) properties in the seedlings of Korean oat (Avena sativa L.) cultivars at different growth times. Nine policosanols in the silylated hexane extracts were detected using GC-MS and their contents showed considerable differences; specifically, hexacosanol (6) exhibited the highest composition, constituting 88-91% of the total average content. Moreover, the average hexacosanol (6) contents showed remarkable variations of 337.8 (5 days) → 416.8 (7 days) → 458.9 (9 days) → 490.0 (11 days) → 479.2 (13 days) → 427.0 mg/100 g (15 days). The seedlings collected at 11 days showed the highest average policosanol content (541.7 mg/100 g), with the lowest content being 383.4 mg/100 g after 5 days. Interestingly, policosanols from oat seedlings grown for 11 days induced the most prevalent phenotype of AMPK activation in HepG2 cells, indicating that policosanols are an excellent AMPK activator.

4.
Adv Mater ; 34(30): e2108841, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35353395

RESUMO

Over the last 30 years, the study of ferroelectric oxides has been revolutionized by the implementation of epitaxial-thin-film-based studies, which have driven many advances in the understanding of ferroelectric physics and the realization of novel polar structures and functionalities. New questions have motivated the development of advanced synthesis, characterization, and simulations of epitaxial thin films and, in turn, have provided new insights and applications across the micro-, meso-, and macroscopic length scales. This review traces the evolution of ferroelectric thin-film research through the early days developing understanding of the roles of size and strain on ferroelectrics to the present day, where such understanding is used to create complex hierarchical domain structures, novel polar topologies, and controlled chemical and defect profiles. The extension of epitaxial techniques, coupled with advances in high-throughput simulations, now stands to accelerate the discovery and study of new ferroelectric materials. Coming hand-in-hand with these new materials is new understanding and control of ferroelectric functionalities. Today, researchers are actively working to apply these lessons in a number of applications, including novel memory and logic architectures, as well as a host of energy conversion devices.

5.
Nano Lett ; 21(10): 4185-4192, 2021 May 26.
Artigo em Inglês | MEDLINE | ID: mdl-33979525

RESUMO

Ruddlesden-Popper (RP) phases (An+1BnO3n+1, n = 1, 2,···) have attracted intensive research with diverse functionalities for device applications. However, the realization of a high-quality RP-phase film is hindered by the formation of out-of-phase boundaries (OPBs) that occur at terrace edges, originating from lattice mismatch in the c-axis direction with the A'B'O3 (n = ∞) substrate. Here, using strontium ruthenate RP-phase Sr2RuO4 (n = 1) as a model system, an experimental approach for suppressing OPBs was developed. By tuning the growth parameters, the Sr3Ru2O7 (n = 2) phase was formed in a controlled manner near the film-substrate interface. This higher-order RP-phase then blocked the subsequent formation of OPBs, resulting in nearly defect-free Sr2RuO4 layer at the upper region of the film. Consequently, the Sr2RuO4 thin films exhibited superconductivity up to 1.15 K, which is the highest among Sr2RuO4 films grown by pulsed laser deposition. This work paves the way for synthesizing pristine RP-phase heterostructures and exploring their unique physical properties.

6.
Anesth Pain Med (Seoul) ; 15(1): 49-52, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-33329789

RESUMO

BACKGROUND: Oocyte retrieval is the most important procedure in in vitro fertilization (IVF). Various anesthetic methods are used to control a patient's anxiety and pain during IVF; however, there are no recommended anesthetic methods at present. In this study, we retrospectively investigated chemical pregnancy rates according to the anesthetic method used for oocyte retrieval. METHODS: We reviewed records of patients who underwent oocyte retrieval between January 1, 2012 and December 31, 2017. Patients were divided into the spinal anesthesia (SA) and monitored anesthesia care (MAC) groups. The primary outcome was chemical pregnancy rate after IVF. RESULTS: The study included 95 patients. SA was administered in 77 (81%) and MAC in 18 (19%). The overall chemical pregnancy rate was 32.6% (31/95). According to the anesthetic method, the pregnancy rate was 32.5% (25/77) in the SA group and 33.3% (6/18) in the MAC group. There was no statistical difference in the pregnancy rate between the groups (P = 0.575). The procedural time was significantly shorter in the SA group than in the MAC group (P < 0.001). CONCLUSIONS: Chemical pregnancy rates were not significantly different between the SA and MAC groups. However, the procedure duration was shorter in the SA group than in the MAC group.

7.
Anesth Pain Med (Seoul) ; 15(2): 205-208, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33329815

RESUMO

BACKGROUND: Herpes zoster ophthalmicus (HZO) is an infectious disease that results from the reactivation of latent varicella zoster virus in the ophthalmic branch of the trigeminal ganglia. HZO manifests with herpes zoster-like symptoms such as rash with or without signs of ocular involvement. Cavernous sinus thrombosis (CST) is a life-threatening condition accompanied by signs and symptoms involving the eyes and the cranial nerves. CASE: We report a case of septic cavernous sinus thrombosis (caused by Streptococcus constellatus subsp. constellatus) which was masked by the simultaneous occurrence of HZO in this patient, resulting in delayed diagnosis. CONCLUSIONS: CST may be obscured by HZO, prompt diagnosis and treatment is necessary when such case arrive.

8.
Nat Commun ; 11(1): 4944, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33009380

RESUMO

Nonequilibrium atomic structures can host exotic and technologically relevant properties in otherwise conventional materials. Oxygen octahedral rotation forms a fundamental atomic distortion in perovskite oxides, but only a few patterns are predominantly present at equilibrium. This has restricted the range of possible properties and functions of perovskite oxides, necessitating the utilization of nonequilibrium patterns of octahedral rotation. Here, we report that a designed metastable pattern of octahedral rotation leads to robust room-temperature ferroelectricity in CaTiO3, which is otherwise nonpolar down to 0 K. Guided by density-functional theory, we selectively stabilize the metastable pattern, distinct from the equilibrium pattern and cooperative with ferroelectricity, in heteroepitaxial films of CaTiO3. Atomic-scale imaging combined with deep neural network analysis confirms a close correlation between the metastable pattern and ferroelectricity. This work reveals a hidden but functional pattern of oxygen octahedral rotation and opens avenues for designing multifunctional materials.

9.
J Nanosci Nanotechnol ; 20(11): 7039-7044, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32604554

RESUMO

Polyacrylonitrile (PAN)/Si composite fibers (electrodes) with flexibility were fabricated using an elec-trospinning method and then Si-embedded carbon (Si/C) fibers were prepared by carbonizing the composite fibers at 800, 900, and 1000°C. Si particles were distributed in the interior and exterior of entangled PAN fibers. After carbonization, the structure of electrodes was preserved but the diameter of fibers was decreased owing to the release of component elements constituting PAN such as nitrogen and oxygen. Crystalline Si particles existed in carbon fibers with both amorphous and crystalline phases. As carbonization temperature increased, the carbon content and the crys-tallinity of carbon increased. The electrode carbonized at 1000°C with the lowest charge transfer resistance exhibited the best electrochemical properties in terms of capacity, coulombic efficiency and cycle life.

10.
J Nanosci Nanotechnol ; 20(11): 7045-7050, 2020 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-32604555

RESUMO

In this work, bare Sn and carbon-coated Sn nanoparticles were prepared by a pulsed wire evaporation process. The effect of binder and pressing ratio on electrochemical properties of Sn/C composite electrodes was investigated to enhance the structural stability of Sn anode. The electrode containing the polyamide-imide (PAI) binder with high tensile strength (52 MPa) exhibited higher coulombic efficiency and better cycle performance compared to the electrode with the conventional polyvinylidene fluoride (PVdF) binder. The 5%-pressed Sn/C electrode with the proper porosity in the electrode demonstrated the best cycle performance corresponding to 45% of capacity retention ratio until 100 cycles.

11.
Nat Commun ; 11(1): 2586, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444818

RESUMO

Dielectrics have long been considered as unsuitable for pure electrical switches; under weak electric fields, they show extremely low conductivity, whereas under strong fields, they suffer from irreversible damage. Here, we show that flexoelectricity enables damage-free exposure of dielectrics to strong electric fields, leading to reversible switching between electrical states-insulating and conducting. Applying strain gradients with an atomic force microscope tip polarizes an ultrathin film of an archetypal dielectric SrTiO3 via flexoelectricity, which in turn generates non-destructive, strong electrostatic fields. When the applied strain gradient exceeds a certain value, SrTiO3 suddenly becomes highly conductive, yielding at least around a 108-fold decrease in room-temperature resistivity. We explain this phenomenon, which we call the colossal flexoresistance, based on the abrupt increase in the tunneling conductance of ultrathin SrTiO3 under strain gradients. Our work extends the scope of electrical control in solids, and inspires further exploration of dielectric responses to strong electromechanical fields.

12.
Phys Chem Chem Phys ; 22(14): 7404-7411, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32215414

RESUMO

Photoelectron circular dichroism (PECD) is a highly sensitive enantiospecific spectroscopy for studying chiral molecules in the gas phase using either single-photon ionization or multiphoton ionization. In the short pulse limit investigated with femtosecond lasers, resonance-enhanced multiphoton ionization (REMPI) is rather instantaneous and typically occurs simultaneously via more than one vibrational or electronic intermediate state due to limited frequency resolution. In contrast, vibrational resolution in the REMPI spectrum can be achieved using nanosecond lasers. In this work, we follow the high-resolution approach using a tunable narrow-band nanosecond laser to measure REMPI-PECD through distinct vibrational levels in the intermediate 3s and 3p Rydberg states of fenchone. We observe the PECD to be essentially independent of the vibrational level. This behaviour of the chiral sensitivity may pave the way for enantiomer specific molecular identification in multi-component mixtures: one can specifically excite a sharp, vibrationally resolved transition of a distinct molecule to distinguish different chiral species in mixtures.

13.
Nano Lett ; 20(4): 2468-2477, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32202801

RESUMO

In quantum matters hosting electron-electron correlation and spin-orbit coupling, spatial inhomogeneities, arising from competing ground states, can be essential for understanding exotic topological properties. A prominent example is Hall anomalies observed in SrRuO3 films, which were interpreted in terms of either magnetic skyrmion-induced topological Hall effect or inhomogeneous anomalous Hall effect (AHE). To clarify this ambiguity, we systematically investigated the evolution of AHE with controllable inhomogeneities in SrRuO3 film thickness (tSRO). By exploiting the step-flow growth of SrRuO3 films, we induced a microscopically ordered stripe pattern with one-unit-cell differences in tSRO. The associated spatial distribution of momentum-space Berry curvatures enables a two-channel AHE with hump-like Hall anomalies, which can be continuously engineered according to non-integer tSRO. We further microscopically characterized the stripe-like ferromagnetic domains and two-step magnetic switching behavior in the inhomogeneous SrRuO3 film. These unique features can be utilized to identify the two-channel AHE model and understand its microscopic origin.

14.
Adv Mater ; 32(8): e1905815, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31830343

RESUMO

The metal-insulator transition (MIT) in transition-metal-oxide is fertile ground for exploring intriguing physics and potential device applications. Here, an atomic-scale MIT triggered by surface termination conversion in SrRuO3 ultrathin films is reported. Uniform and effective termination engineering at the SrRuO3 (001) surface can be realized via a self-limiting water-leaching process. As the surface termination converts from SrO to RuO2 , a highly insulating and nonferromagnetic phase emerges within the topmost SrRuO3 monolayer. Such a spatially confined MIT is corroborated by systematic characterizations on electrical transport, magnetism, and scanning tunneling spectroscopy. Density functional theory calculations and X-ray linear dichroism further suggest that the surface termination conversion breaks the local octahedral symmetry of the crystal field. The resultant modulation in 4d orbital occupancy stabilizes a nonferromagnetic insulating surface state. This work introduces a new paradigm to stimulate and tune exotic functionalities of oxide heterostructures with atomic precision.

15.
Arch Craniofac Surg ; 20(1): 62-65, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30840819

RESUMO

Odontoma is an asymptomatic slow-growing odontogenic tumor. It is usually found by chance in the maxilla or mandible on radiography, or when it deforms the adjacent teeth. It is commonly found in patients who are 30 years of age or younger. We report our encounter with an odontoma within a dentigerous cyst found incidentally in a 56-year-old man. He presented with abnormal fullness in the right infraorbital area of the cheek. During the evaluation of the mass, we incidentally detected the odontogenic tumor within a dentigerous cyst in the patient's maxilla. Under general anesthesia, complete surgical drainage of the infraorbital cystic mass was performed. Enucleation of the odontogenic tumor and a bone grafting from the iliac bone were also performed. The final diagnosis was odontoma. After 2 years of follow-up, there was no sign of recurrence of the tumor. In case of odontogenic tumors, even in old patients, it is important to suspect an odontoma. When odontoma accompanies a dentigerous cyst, surgical excisional biopsy should be performed to rule out malignancy. In case of a large bony defect after enucleation, autogenous bone grafting is essential for reconstruction.

16.
Arch Craniofac Surg ; 19(4): 270-274, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30613088

RESUMO

BACKGROUND: Nasal bone fractures occur frequently because the nasal bone is located at the forefront of the face. The goal of this study was to examine the cause, change in severity, change in incidence, and demographics of nasal bone fracture according to today's lifestyle. METHODS: A total of 2,092 patients diagnosed as having nasal bone fractures at our department between 2002 and 2017 were included in this study. We retrospectively examined patients' medical records to extract information regarding age, sex, cause of injury, combined facial bone fractures, and related injuries such as skull base fracture, spinal cord injury, brain hemorrhage, and other bone fractures. Fracture severity was classified by nasal bone fracture type. RESULTS: No statistically significant difference was found in annual number of patients treated for nasal bone fracture. The proportion of patients who underwent closed reduction was significantly decreased over time for those with nasal bone fractures caused by traffic accidents. However, it was not significantly changed for those with nasal bone fractures due to other causes. The number of patients with combined facial bone fractures increased over time. Incidences of severe nasal bone fracture also increased over time. CONCLUSION: The study suggested that there is a decrease in the frequency and increase in the severity of nasal bone fracture due to traffic accident. Many protective devices prevent nasal bone fractures caused by a small amount of external force; however, these devices are not effective against higher amounts of external force. This study highlights the importance of preoperative thorough evaluation to manage patients with nasal bone fractures due to traffic accident.

17.
Arch Craniofac Surg ; 19(4): 287-290, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30613092

RESUMO

Tumoral calcinosis is a condition characterized by deposition of calcium salts in the skin and sub- cutaneous tissue, commonly found around the joints. However, tumoral calcinosis of the auricle is extremely rare. We present the case of a 13-year-old boy with tumoral calcinosis of the helix of the ear auricle. A 13-year-old boy presented with a 10-year history of an enlarging mass on the left auricle. The mass was hard, non-tender, and non-compressible. The patient had no history of trauma. Complete surgical excision and pathological examination of the specimen was performed. The final diagnosis of the excised mass was tumoral calcinosis. After 9 months of follow-up, there were no signs of recurrence of the tumor and the patient was satisfied with the surgical results. Tumoral calcinosis of the auricle is extremely rare and may be misdiagnosed as other tumors. Pathological examination is essential for definitive diagnosis and complete surgical excision should be considered as the treatment of choice.

18.
Nat Commun ; 7: 13317, 2016 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-27796372

RESUMO

Establishing a reliable method to form scalable neutral-atom platforms is an essential cornerstone for quantum computation, quantum simulation and quantum many-body physics. Here we demonstrate a real-time transport of single atoms using holographic microtraps controlled by a liquid-crystal spatial light modulator. For this, an analytical design approach to flicker-free microtrap movement is devised and cold rubidium atoms are simultaneously rearranged with 2N motional degrees of freedom, representing unprecedented space controllability. We also accomplish an in situ feedback control for single-atom rearrangements with the high success rate of 99% for up to 10 µm translation. We hope this proof-of-principle demonstration of high-fidelity atom-array preparations will be useful for deterministic loading of N single atoms, especially on arbitrary lattice locations, and also for real-time qubit shuttling in high-dimensional quantum computing architectures.

19.
Opt Lett ; 40(4): 510-3, 2015 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-25680137

RESUMO

We consider the Rabi oscillation of an atom ensemble of Gaussian spatial distribution interacting with ultrafast laser pulses. Based on an analytical model calculation, we show that its dephasing dynamics is solely governed by the size ratio between the atom ensemble and the laser beam, and that every oscillation peak of the inhomogeneously broadened Rabi flopping falls on the homogeneous Rabi oscillation curve. The results are verified experimentally with a cold rubidium vapor in a magneto-optical trap. As a robust means to achieve higher-fidelity population inversion of the atom ensemble, we demonstrate a spin-echo type R(x)(π/2)R(y)(π)R(x)(π/2) composite interaction as well.

20.
Sci Rep ; 4: 5867, 2014 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-25070166

RESUMO

Quantum computing is based on unitary operations in a two-level quantum system, a qubit, as the fundamental building block, and the ability to perform qubit operations in an amount of time that is considerably shorter than the coherence time is an essential requirement for quantum computation. Here, we present an experimental demonstration of arbitrary single-qubit SU(2) quantum gate operations achieved at a terahertz clock speed. Implemented by coherent control methods of tailored ultrafast laser interaction with cold rubidium atomic qubits, Bloch vector manipulation about all three rotational axes was successfully demonstrated. The dynamic evolution of the qubits was successfully measured by devised femtosecond Ramsey interferometry. We anticipate this demonstration to be a starting point to process quantum algorithm in a simplified manner by a programmed sequence of femtosecond laser pulses.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...