Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 15 de 15
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
J Cancer Prev ; 27(4): 239-246, 2022 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-36713940

RESUMO

Since ancient times, honey has been used in traditional medicine owing to its pharmacological effects. It possesses anticancer properties. However, the therapeutic implications of Sangju honey in cancer remains unknown. Therefore, we aimed to demonstrate the potential anticancer effects of Sangju honey on human oral squamous cell carcinoma (OSCC), particularly focusing on epithelial-mesenchymal transition (EMT) and apoptotic and mitogen-activated protein kinase (MAPK) signaling pathways. Ca9-22 and YD-10B human OSCC cells were treated with 0.25% or 0.5% Sangju honey, and the cell viability was examined using the Cell Counting Kit-8 assay. Cell morphology studies were conducted to observe morphological changes, and the wound-healing assay was performed to evaluate the proliferation of honey-treated OSCC cells. Western blot analysis was conducted to investigate protein expression related to EMT and apoptotic and MAPK signaling pathways. Sangju honey reduced cell viability, induced morphological changes, and significantly suppressed the proliferation and migration of Ca9-22 and YD-10B cells. The expression of E-cadherin and N-cadherin was increased and decreased, respectively, in both OSCC cell lines. Moreover, Sangju honey stimulated apoptosis by increasing the expression of p21, p53, cleaved caspase 3, and caspase 9. Furthermore, it downregulated the expression of phospho (p)-extracellular signal-regulated kinases 1 and 2, p-c-Jun amino-terminal kinase, and p-p38 in Ca9-22 and YD-10B cells. Sangju honey inhibits Ca9-22 and YD-10B cell proliferation by regulating EMT, inducing apoptosis, and suppressing the MAPK signaling pathway. Thus, it is a potential anticancer agent for human OSCC.

2.
Appl Opt ; 60(5): 1191-1195, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33690549

RESUMO

We have developed a high-power ultraviolet (UV) nanosecond-pulsed laser based on a rod-type photonic crystal fiber. The UV pulse energy and the pulse repetition rate are 0.75 mJ and 100 kHz, respectively, yielding 75-W UV average power. The temporal pulse shape and the linewidth of a 1030-nm seed laser are optimized for efficient third-harmonic generation, and the high conversion efficiency of 50% is achieved with a good beam quality (M2∼1.2). To our knowledge, this is the highest UV pulse energy from fiber lasers.

3.
Chemosphere ; 263: 127903, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32841873

RESUMO

In this study, seasonal/regional variations of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and dioxin like-polychlorinated biphenyls in the ambient air were monitored for ten years (2008-2017) using a high volume air sampler. As a result of strict regulation enforced by Korea Ministry of Environment in 2008, PCDD/DFs concentrations in the ambient air decreased from 0.051 pg I-TEQ Sm-3 in 2009 to 0.014 pg I-TEQ Sm-3 in 2017 which was comparably associated with cut-down of their emission sources from 880.2 g I-TEQ Sm-3 in 2001 to 24.2 g I-TEQ Sm-3 in 2015; revealing that it was only 2.7% against that of 2001. In 2017, mean TEQ concentration level of PCDD/DFs in the air of South Korea was quite low in comparison to its ambient environmental standards of 0.6 pg I-TEQ Sm-3 for PCDD/DFs. Particularly, the sum of PCDD/DFs in the background revealed the lowest level, however, the fraction of octachlorodibenzodioxin among other isomers exposed at the highest level in this study, suggesting that the ambient air quality in the background being studied was severely and persistently impaired by inflowing unknown sources of any possible anthropogenic transboundary migratory air pollutants. Moreover, this study conducted the scientific analysis of the long-term variations in the ambient air and emission sources using principal component analysis. From this of 10 years long-term nationwide assessments for the PCDD/DFs and dl-PCBs in the ambient air, it is possible to prove that South Korean environmental policy to manage POPs has been successfully conducted for the last ten years.


Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/estatística & dados numéricos , Dibenzofuranos Policlorados/análise , Monitoramento Ambiental , Dibenzodioxinas Policloradas/análise , Ar/análise , Poluição do Ar/análise , Benzofuranos/análise , Dibenzofuranos/análise , Dioxinas/análise , Bifenilos Policlorados/análise , República da Coreia , Estações do Ano
4.
Disabil Rehabil Assist Technol ; 14(5): 526-531, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30318956

RESUMO

Aim: To design and manufacture a patient-specific assistive device optimized for patient function after estimating the disability status of a patient with brain injury through 3D printing technique Materials and methods: The left hand of a man with right-side hemiparesis was scanned with a three-dimensional scanner, and the left-hand image was flipped over to the right side to design the orthosis. To change devices easily, a connector was designed to connect the devices and was easily detachable with the orthosis by using the magnetics. To enable the writing, a round-shaped ring was attached to the orthosis to fix a pen. The Jebsen-Taylor Hand Function Test (JHFT) and Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST) were evaluated one month after the application. Results: The JHFT score improved after application 3D printed devices. In most QUEST items, 3D printed devices showed better results than ready-made assistive devices. The typing speed became faster in 3D printed devices than in ready-made assistive devices. The patient was satisfied with the orthosis in writing a pen, eating food and typing keyboard because of its fitness to his hand and easy-to-use. Conclusion: We designed and manufactured a patient-specific assistive device optimized for patient function after estimating the disability status of a patient with brain injury through 3D printing techniques. We hope to provide low-cost, customized devices to disabled patients through 3D printing techniques. Implications for Rehabilitation We designed and manufactured a patient-specific assistive device optimized for patient function through 3D printing technique. We hope to provide low-cost, customized devices to disabled patients through 3D printing techniques.


Assuntos
Desenho Assistido por Computador , Mãos/fisiopatologia , Paresia/reabilitação , Impressão Tridimensional , Desenho de Prótese , Adulto , Humanos , Masculino , Satisfação do Paciente , Adulto Jovem
5.
Prosthet Orthot Int ; 42(6): 636-643, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30009672

RESUMO

BACKGROUND:: Three-dimensional printer technology can produce the personalized orthosis in various forms. OBJECTIVE:: To develop a personalized wrist orthosis using a three-dimensional scanner and three-dimensional printer for patients with wrist pain. STUDY DESIGN:: A preliminary, prospective, randomized, open-label study. METHODS:: A total of 22 patients with wrist pain were randomly assigned to the control and experimental groups. The control group wore a cock-up orthosis and the experimental group wore a three-dimensional-printed wrist orthosis for 1 week. The Patient-Rated Wrist Evaluation, Jebsen Hand Function Test, and Orthotics and Prosthetics Users' Survey were checked before and 1 week after the application. RESULTS:: The Patient-Rated Wrist Evaluation showed significant pain relief in both groups. Two items of the 28 Orthotics and Prosthetics Users' Survey questions, "Put toothpaste on brush and brush teeth" and "Dial a touch tone phone," showed high satisfaction scores, with statistically significant difference in the experimental group ( p = 0.036 and 0.004). CONCLUSION:: The three-dimensional-printed wrist orthosis was superior to the cock-up orthosis for two items of the Orthotics and Prosthetics Users' Survey. Wrist pain was reduced in the group wearing the three-dimensional-printed wrist orthosis as well as the group wearing the cock-up orthosis, so the three-dimensional-printed wrist orthosis could possibly play the same role as the cock-up orthosis. CLINICAL RELEVANCE: A three-dimensional-printed wrist orthosis can be a substitute for a conventional ready-made wrist orthosis for patients with wrist pain with more satisfaction.


Assuntos
Artralgia/terapia , Desenho de Equipamento , Aparelhos Ortopédicos , Impressão Tridimensional , Articulação do Punho , Atividades Cotidianas , Adulto , Artralgia/etiologia , Feminino , Humanos , Masculino , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
6.
Prosthet Orthot Int ; 42(1): 107-111, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27913783

RESUMO

BACKGROUND AND AIM: Three-dimensional printer is widely used in industry, biology, and medical fields. We report a finger prosthesis produced by a three-dimensional scanner and printer for a 67-year-old man with a right thumb amputation above the metacarpophalangeal joint. TECHNIQUE: His right amputated and left intact hands were scanned with a three-dimensional scanner, and the left-hand image was rotated to the right side to design the right thumb prosthesis. The designed prosthesis was printed with a three-dimensional printer using the fused filament fabrication output system. DISCUSSION: The Jebsen-Taylor hand function test and Box and Block Test scores improved after application of the prosthesis. Most Quebec User Evaluation of Satisfaction with Assistive Technology results were "very satisfied," and most Orthotics and Prosthetics Users' Survey results were "very easy." Preparing the prosthesis made by three-dimensional scanner and three-dimensional printer was faster and cheaper than preparing a conventional prosthesis. Clinical relevance Using three-dimensional scanning and printing technique, we can easily produce specifically shaped finger prostheses for specific movements in amputated patients with low cost.


Assuntos
Amputação Traumática/reabilitação , Membros Artificiais , Atividade Motora/fisiologia , Impressão Tridimensional , Desenho de Prótese , Polegar/lesões , Atividades Cotidianas , Idoso , Humanos , Masculino
7.
Opt Express ; 25(16): 19309-19319, 2017 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-29041124

RESUMO

Techniques for wavefront improvement in an end-pumped Nd:YAG zigzag slab laser amplifier were proposed and demonstrated experimentally. First, a study on the contact materials was conducted to improve the heat transfer between the slab and cooling blocks and to increase the cooling uniformity. Among many attempts, only the use of silicon oil showed an improvement in the wavefront. Thus, the appropriate silicone oil was applied to the amplifier as a contact material. In addition, the wavefront compensation method using a glass rod array was also applied to the amplifier. A very low wavefront distortion was obtained through the use of a silicone-oil contact and glass rod array. The variance of the optical path difference for the entire beam height was 3.87 µm at a pump power of 10.6 kW, and that for the 80% section was 1.69 µm. The output power from the oscillator was 3.88 kW, which means the maximum output extracted from the amplifier at a pump power of 10.6 kW.

8.
Appl Bionics Biomech ; 2017: 9610468, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28827977

RESUMO

We described 3D printing technique and automated design software and clinical results after the application of this AFO to a patient with a foot drop. After acquiring a 3D modelling file of a patient's lower leg with peroneal neuropathy by a 3D scanner, we loaded this file on the automated orthosis software and created the "STL" file. The designed AFO was printed using a fused filament fabrication type 3D printer, and a mechanical stress test was performed. The patient alternated between the 3D-printed and conventional AFOs for 2 months. There was no crack or damage, and the shape and stiffness of the AFO did not change after the durability test. The gait speed increased after wearing the conventional AFO (56.5 cm/sec) and 3D-printed AFO (56.5 cm/sec) compared to that without an AFO (42.2 cm/sec). The patient was more satisfied with the 3D-printed AFO than the conventional AFO in terms of the weight and ease of use. The 3D-printed AFO exhibited similar functionality as the conventional AFO and considerably satisfied the patient in terms of the weight and ease of use. We suggest the possibility of the individualized AFO with 3D printing techniques and automated design software.

9.
Opt Express ; 24(13): 14152-8, 2016 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-27410573

RESUMO

We demonstrate an all-fiber Tm-doped soliton laser with high power by using a monolayer graphene saturable absorber (SA). Large area, uniform monolayer graphene was transferred to the surface of the side-polished fiber (SPF) to realize an in-line graphene SA that operates around 2 µm wavelength. To increase the nonlinear interaction with graphene, we applied an over-cladding onto the SPF, where enhanced optical absorption at monolayer graphene was observed. All-fiber Tm-doped mode-locked laser was built including our in-line graphene SA, which stably delivered the soliton pulses with 773 fs pulse duration. The measured 3-dB spectral bandwidth was 5.14 nm at the wavelength of 1910 nm. We obtained the maximum average output power of 115 mW at a repetition rate of 19.31 MHz. Corresponding pulse energy was estimated to be 6 nJ, which is the highest value among all-fiber Tm-doped soliton oscillators using carbon-material-based SAs.

10.
Appl Opt ; 54(2): 189-94, 2015 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-25967616

RESUMO

We report the observation of transverse mode instability (TMI) in a pulsed single-frequency ytterbium-doped large-core fiber amplifier in which stimulated Brillouin scattering (SBS) is generated easily owing to the high peak power and narrow linewidth of the laser pulses. It was shown experimentally that the threshold of TMI is almost the same as that of SBS and that the suppression of SBS also increases the threshold of TMI, which indicates that the TMI originates from SBS in the fiber.

11.
Opt Express ; 22(19): 22667-72, 2014 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-25321735

RESUMO

We demonstrate a dissipative soliton fiber laser with high pulse energy (>30 nJ) based on a single-walled carbon nanotube saturable absorber (SWCNT-SA). In-line SA that evanescently interacts with the high quality SWCNT/polymer composite film was fabricated under optimized conditions, increasing the damage threshold of the saturation fluence of the SA to 97 mJ/cm(2). An Er-doped mode-locked all-fiber laser operating at net normal intra-cavity dispersion was built including the fabricated in-line SA. The laser stably delivers linearly chirped pulses with a pulse duration of 12.7 ps, and exhibits a spectral bandwidth of 12.1 nm at the central wavelength of 1563 nm. Average power of the laser output is measured as 335 mW at an applied pump power of 1.27 W. The corresponding pulse energy is estimated to be 34 nJ at the fundamental repetition rate of 9.80 MHz; this is the highest value, to our knowledge, reported in all-fiber Er-doped mode-locked laser using an SWCNT-SA.


Assuntos
Tecnologia de Fibra Óptica/instrumentação , Lasers de Estado Sólido , Luz , Nanotubos de Carbono/química , Desenho de Equipamento
12.
Appl Opt ; 49(9): 1666-70, 2010 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-20300165

RESUMO

We have generated continuous-wave single-frequency 1.5 W 378 nm radiation by frequency doubling a high-power Ti:sapphire laser in an external enhancement cavity. An LBO crystal that is Brewster-cut and antireflection coated on both ends is used for a long-term stable frequency doubling. By optimizing the input coupler's reflectivity, we could generate 1.5 W 378 nm radiation from a 5 W 756 nm Ti:sapphire laser. According to our knowledge, this is the highest CW frequency-doubled power of a Ti:sapphire laser.

13.
Opt Express ; 16(7): 4866-71, 2008 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-18542585

RESUMO

We have developed a 5-W 756-nm injection-locked Ti:sapphire laser and frequency-doubled it in an external enhancement cavity for the generation of watt-level 378-nm single-frequency radiation, which is essential for isotope-selective optical pumping of thallium atoms. With a lithium triborate (LBO) crystal in the enhancement cavity, 1.1 W at 378 nm was coupled out from the cavity. Such results are to our knowledge the highest powers of continuous-wave single-frequency radiation generated from a Ti:sapphire laser and its frequency doubling.


Assuntos
Óxido de Alumínio , Desenho Assistido por Computador , Lasers , Modelos Teóricos , Titânio , Simulação por Computador , Desenho de Equipamento , Análise de Falha de Equipamento
14.
Appl Opt ; 46(28): 6854-8, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17906710

RESUMO

We have analyzed the temporal characteristics of amplified spontaneous emission (ASE) in femtosecond terawatt Ti:sapphire lasers by using a simple method based on fast photodiodes. Instead of measuring ASE directly with fast photodiodes, we created a narrow gap in the spectrum of seed pulses and, after amplification, detected the pure ASE signal through the gap by using a fast photodiode covered with a bandpass filter with high transmission at the gap. Because the detected ASE signal was completely separated from amplified main pulses, preceding and even trailing ASEs could be characterized quantitatively in a single-shot measurement. We believe that our method is a good alternative or a complement to conventional methods for ASE measurements.

15.
Appl Opt ; 44(36): 7810-3, 2005 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-16381532

RESUMO

We have developed a 756 nm, 3 W single-frequency cw Ti:sapphire laser by using the technique of injection locking. A cw Ti:sapphire laser in a ring-type configuration was forced to lase unidirectionally by use of an optical diode to prevent a high-power backward laser from disturbing the injection laser. A master laser was amplified by a broad-area laser diode and coupled into a single-mode fiber to generate a 50 mW injection laser with a Gaussian beam profile, which was enough to lock the Ti:sapphire laser at full power of 3 W. Such a high-power single-frequency Ti:sapphire laser enables a watt-level blue or near-ultraviolet single-frequency laser to be generated by frequency doubling.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...