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1.
Sensors (Basel) ; 23(10)2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37430754

RESUMEN

This paper describes Monolithic Microwave Integrated Circuits (MMICs) for an X-band radar transceiver front-end implemented in 0.25 µm GaN High Electron Mobility Transistor (HEMT) technology. Two versions of single pole double throw (SPDT) T/R switches are introduced to realize a fully GaN-based transmit/receive module (TRM), each of which achieves an insertion loss of 1.21 dB and 0.66 dB at 9 GHz, IP1dB higher than 46.3 dBm and 44.7 dBm, respectively. Therefore, it can substitute a lossy circulator and limiter used for a conventional GaAs receiver. A driving amplifier (DA), a high-power amplifier (HPA), and a robust low-noise amplifier (LNA) are also designed and verified for a low-cost X-band transmit-receive module (TRM). For the transmitting path, the implemented DA achieves a saturated output power (Psat) of 38.0 dBm and output 1-dB compression (OP1dB) of 25.84 dBm. The HPA reaches a Psat of 43.0 dBm and power-added efficiency (PAE) of 35.6%. For the receiving path, the fabricated LNA measures a small-signal gain of 34.9 dB and a noise figure of 2.56 dB, and it can endure higher than 38 dBm input power in the measurement. The presented GaN MMICs can be useful in implementing a cost-effective TRM for Active Electronically Scanned Array (AESA) radar systems at X-band.

2.
J Transl Med ; 9: 181, 2011 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-22017805

RESUMEN

Prolonged life expectancy, life style and environmental changes have caused a changing disease pattern in developed countries towards an increase of degenerative and autoimmune diseases. Stem cells have become a promising tool for their treatment by promoting tissue repair and protection from immune-attack associated damage. Patient-derived autologous stem cells present a safe option for this treatment since these will not induce immune rejection and thus multiple treatments are possible without any risk for allogenic sensitization, which may arise from allogenic stem cell transplantations. Here we report the outcome of treatments with culture expanded human adipose-derived mesenchymal stem cells (hAdMSCs) of 10 patients with autoimmune associated tissue damage and exhausted therapeutic options, including autoimmune hearing loss, multiple sclerosis, polymyotitis, atopic dermatitis and rheumatoid arthritis. For treatment, we developed a standardized culture-expansion protocol for hAdMSCs from minimal amounts of fat tissue, providing sufficient number of cells for repetitive injections. High expansion efficiencies were routinely achieved from autoimmune patients and from elderly donors without measurable loss in safety profile, genetic stability, vitality and differentiation potency, migration and homing characteristics. Although the conclusions that can be drawn from the compassionate use treatments in terms of therapeutic efficacy are only preliminary, the data provide convincing evidence for safety and therapeutic properties of systemically administered AdMSC in human patients with no other treatment options. The authors believe that ex-vivo-expanded autologous AdMSCs provide a promising alternative for treating autoimmune diseases. Further clinical studies are needed that take into account the results obtained from case studies as those presented here.


Asunto(s)
Tejido Adiposo/citología , Enfermedades Autoinmunes/terapia , Técnicas de Cultivo de Célula/métodos , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Adulto , Anciano , Animales , Proliferación Celular , Ensayos de Uso Compasivo , Humanos , Ratones , Ratones SCID , Persona de Mediana Edad , Trasplante Autólogo , Adulto Joven
3.
BMC Public Health ; 11: 468, 2011 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-21669004

RESUMEN

BACKGROUND: There are many differences in culture, community identity, community participation, and ownership between communities in Western and Asian countries; thus, it is difficult to adopt the results of community intervention studies from Western countries. In this study, we conducted a multicity, multicomponent community intervention trial to correct breast cancer myths and promote screening mammography for women living in an urban community in Korea. METHODS: A 6-month, 2-city community intervention trial was conducted. In the intervention city, 480 women were surveyed at baseline and 7 months later to evaluate the effects of the intervention program. Strategies implemented in the intervention city included community outreach and clinic and pharmacy-based in-reach strategies. RESULTS: This study showed a 20.4-percentage-point decrease in myths about the link between cancer and breast size, a 19.2-percentage-point decrease in myths concerning mammography costs, and a 14.1-percentage-point increase in intention to undergo screening mammography. We also saw a 23.4-percentage-point increase in the proportion of women at the action stage of the transtheoretical model in the intervention city. In the comparison city, smaller decreases and increases were observed. CONCLUSIONS: Our study showed the value of an intervention study aimed at reducing belief in breast cancer myths in an urban community in Korea. The invention also made women more likely to undergo mammography in future.


Asunto(s)
Neoplasias de la Mama , Redes Comunitarias , Conocimientos, Actitudes y Práctica en Salud , Promoción de la Salud , Tamizaje Masivo , Adulto , Anciano , Femenino , Encuestas de Atención de la Salud , Humanos , Persona de Mediana Edad , República de Corea
4.
Org Lett ; 19(24): 6642-6645, 2017 12 15.
Artículo en Inglés | MEDLINE | ID: mdl-29192789

RESUMEN

The first total synthesis of (+)-intricenyne consisting of an oxocane skeleton was achieved via an extremely selective endocyclization strategy. The key features of the synthesis include a regio- and diastereoselective epoxide opening reaction, concise elaboration of oxocane cores via abnormally selective endocyclization ether ring formation, and versatile incorporation of the labile functional groups.

5.
Neurobiol Aging ; 36(10): 2885-92, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26242706

RESUMEN

The treatment of Parkinson's disease (PD) using stem cells has long been the focus of many researchers, but the ideal therapeutic strategy has not yet been developed. The consistency and high reliability of the experimental results confirmed by animal models are considered to be a critical factor in the stability of stem cell transplantation for PD. Therefore, the aim of this study was to investigate the preventive and therapeutic potential of human adipose-derived stem cells (hASC) for PD and was to identify the related factors to this therapeutic effect. The hASC were intravenously injected into the tail vein of a PD mouse model induced by 6-hydroxydopamine. Consequently, the behavioral performances were significantly improved at 3 weeks after the injection of hASC. Additionally, dopaminergic neurons were rescued, the number of structure-modified mitochondria was decreased, and mitochondrial complex I activity was restored in the brains of the hASC-injected PD mouse model. Overall, this study underscores that intravenously transplanted hASC may have therapeutic potential for PD by recovering mitochondrial functions.


Asunto(s)
Adipocitos/citología , Enfermedad de Parkinson/terapia , Trasplante de Células Madre/métodos , Células Madre , Animales , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/patología , Complejo I de Transporte de Electrón/deficiencia , Humanos , Masculino , Ratones Endogámicos C57BL , Mitocondrias/patología , Enfermedades Mitocondriales/etiología , Enfermedades Mitocondriales/terapia , Oxidopamina , Enfermedad de Parkinson/complicaciones , Enfermedad de Parkinson/patología , Enfermedad de Parkinson/prevención & control
6.
Asian Pac J Cancer Prev ; 13(2): 437-41, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22524802

RESUMEN

OBJECTIVE: Health risk appraisal is often utilized to modify individual's health behavior, especially concerning disease prevention, and web-based health risk appraisal services are being provided to the general public in Korea. However, little is known about the psychological effect of the health risk appraisal even though poorly communicated information by the web-based service may result in unintended adverse health outcomes. This study was conducted to explore the psychological effect of health risk appraisal using epidemiological risk factor profile. METHODS: We conducted a randomized trial comparing risk factor list type health risk appraisal and risk score type health risk appraisal. We studied 60 women aged 30 years and older who had no cancer. Anxiety level was assessed using the Spielberger State-Trait Anxiety Inventory YZ. RESULTS: The results of multivariate analysis showed that risk status was the independent predictors of increase of state anxiety after health risk appraisal intervention when age, education, health risk appraisal type, numeracy, state anxiety, trait anxiety, and health risk appraisal type by risk status interaction was adjusted. Women who had higher risk status had an odd of having increased anxiety that was about 5 times greater than women who had lower risk status. CONCLUSIONS: Our findings indicate that communicating the risk status by individual health risk appraisal service can induce psychological sequelae, especially in women having higher risk status. Hospitals, institutes, or medical schools that are operating or planning to operate the online health risk appraisal service should take side effects such as psychological sequelae into consideration.


Asunto(s)
Neoplasias de la Mama/etiología , Neoplasias de la Mama/psicología , Indicadores de Salud , Internet , Estrés Psicológico , Adulto , Anciano , Neoplasias de la Mama/epidemiología , Femenino , Humanos , Persona de Mediana Edad , Pronóstico , República de Corea/epidemiología , Medición de Riesgo
7.
PLoS One ; 7(9): e45757, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23049854

RESUMEN

Alzheimer's disease (AD) is characterized by the accumulation of amyloid plaques and neurofibrillary tangles accompanied by cognitive dysfunction. The aim of the present study was to elucidate preventive and therapeutic potential of stem cells for AD. Among stem cells, autologous human adipose-derived stem cells (hASCs) elicit no immune rejection responses, tumorigenesis, or ethical problems. We found that intravenously transplanted hASCs passed through the BBB and migrated into the brain. The learning, memory and pathology in an AD mouse model (Tg2576) mice greatly improved for at least 4 months after intravenous injection of hASC. The number of amyloid plaques and Aß levels decreased significantly in the brains of hASC-injected Tg mice compared to those of Tg-sham mice. Here, we first report that intravenously or intracerebrally transplanted hASCs significantly rescues memory deficit and neuropathology, in the brains of Tg mice by up-regulating IL-10 and VEGF and be a possible use for the prevention and treatment of AD.


Asunto(s)
Tejido Adiposo/citología , Enfermedad de Alzheimer/metabolismo , Tratamiento Basado en Trasplante de Células y Tejidos/métodos , Regulación de la Expresión Génica , Proteínas Amiloidogénicas/metabolismo , Animales , Encéfalo/metabolismo , Modelos Animales de Enfermedad , Femenino , Humanos , Inyecciones Intravenosas , Interleucina-10/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Transgénicos , Microscopía Fluorescente/métodos , Factores de Tiempo , Regulación hacia Arriba , Factor A de Crecimiento Endotelial Vascular/metabolismo
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