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1.
J Am Chem Soc ; 145(37): 20539-20550, 2023 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-37697685

RESUMO

We have applied an underexplored backbone modification strategy to generate new analogues of peptides that activate two clinically important class B1 G protein-coupled receptors (GPCRs). Most peptide modification strategies involve changing side chains or, less commonly, changing the configuration at side chain-bearing carbons (i.e., l residues replaced by d residues). In contrast, backbone modifications alter the number of backbone atoms and the identities of backbone atoms relative to a poly-α-amino acid backbone. Starting from the peptide agonists PTH(1-34) (the first 34 residues of the parathyroid hormone, used clinically as the drug teriparatide) and glucagon-like peptide-1 (7-36) (GLP-1(7-36)), we replaced native α-residue triads with a diad composed of a ß-amino acid residue and a γ-amino acid residue. The ß/γ diad retains the number of backbone atoms in the ααα triad. Because the ß and γ residue each bear a single side chain, we implemented ααα→ßγ replacements at sites that contained a Gly residue (i.e., at α-residue triads that presented only two side chains). All seven of the α/ß/γ-peptides derived from PTH(1-34) or GLP-1(7-36) bind to the cognate receptor (the PTHR1 or the GLP-1R), but they vary considerably in their activity profiles. Outcomes include functional mimicry of the all-α agonist, receptor-selective agonist activity, biased agonism, or strong binding with weak activation, which could lead to antagonist development. Collectively, these findings demonstrate that ααα→ßγ replacements, which are easily implemented via solid-phase synthesis, can generate peptide hormone analogues that display unique and potentially useful signaling behavior.


Assuntos
Hormônio Paratireóideo , Transdução de Sinais , Aminoácidos , Carbono , Peptídeo 1 Semelhante ao Glucagon
2.
Medicina (Kaunas) ; 59(7)2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37512054

RESUMO

Background and Objectives: The goal in treating anterior cruciate ligament (ACL) injury especially in revision cases is return to sports activity by regaining dynamic postural stability. Among various methods to achieve this goal, additional anterolateral ligament reconstruction (ALLR) is gaining attention. The purpose of this study was to evaluate the effects of additional ALLR in revision ACL reconstruction (RACLR). Materials and Methods: Patients who underwent RACLR between July 2015 and June 2018 were enrolled. The exclusion criteria were less than 1-year follow-up, age older than 45 years, concomitant multiple ligament injuries, contralateral knee injury, subtotal or total meniscectomized state, and articular cartilage lesions worse than Outerbridge grade 3. Thirty-nine patients (20 patients; RACLR only (Group A), 19 patients; RACLR with additional ALLR (Group B)) were included. Clinical scores (Lysholm score, subjective International Knee Documentation Committee (IKDC) score, Tegner activity scale), isokinetic strength test, single-leg-hop for distance test (SLHDT), Y-balance test (YBT) were checked preoperatively and 1-year postoperatively. Results: Limb symmetry index values in YBT showed significantly better result in Group B 1-year postoperatively (Group A: 97.2 ± 4.0, Group B: 100.3 ± 2.9, p = 0.010), although there were no differences preoperatively between groups (Group A: 90.4 ± 6.7, Group B: 89.3 ± 5.5, p = 0.594). Regarding clinical scores, isokinetic strength tests, and SLHDT, there were no differences between groups preoperatively nor 1-year postoperatively. Conclusions: Additional ALLR in RACLR helped patients gain better dynamic postural stability at 1-year postoperative follow-up.


Assuntos
Lesões do Ligamento Cruzado Anterior , Reconstrução do Ligamento Cruzado Anterior , Humanos , Pessoa de Meia-Idade , Ligamento Cruzado Anterior , Seguimentos , Articulação do Joelho/cirurgia , Lesões do Ligamento Cruzado Anterior/cirurgia , Reconstrução do Ligamento Cruzado Anterior/métodos , Extremidade Inferior , Resultado do Tratamento
3.
Microsurgery ; 42(5): 470-479, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35175656

RESUMO

PURPOSE: Free tissue transfer is a treatment option for soft tissue defects of the lower extremity. For a successful outcome, it is necessary to evaluate the vessel condition and blood flow patency. The administration of a vasopressor could impact the survival rate of free tissue transfer; however, there is a lack of studies on vasopressor use and lower extremity reconstruction. This study aimed to investigate the relationship between the use of a vasopressor and outcomes of free tissue transfer in lower extremity reconstruction. METHODS: This retrospective, observational study was conducted between March 2010 and February 2019. Data were divided into intraoperative and postoperative variables according to the administration time. Data on patient demographics, risk factors, details of reconstruction, flap outcomes, and duration of intensive care unit (ICU) stay were obtained. Binary logistic regression models were computed to determine the association between flap outcome and vasopressor administration. RESULTS: Of the 338 patients, 186 were administered a vasopressor. Intraoperative and postoperative vasopressor use was not related to the overall complication rate (odds ratio, 1.547; 95% confidence interval, 0.830-2.882; p = .169). Low-intraoperative levels of hemoglobin were associated with the overall complication rate. Postoperative vasopressor administration was associated with prolonged ICU stay. CONCLUSION: Our results showed that the intraoperative and postoperative use of vasopressors was not significantly associated with the success rate of free flaps. Future studies investigating the relationship between the dose, type, and duration of vasopressors and the complication rate following free tissue transfer are warranted.


Assuntos
Retalhos de Tecido Biológico , Procedimentos de Cirurgia Plástica , Retalhos de Tecido Biológico/irrigação sanguínea , Sobrevivência de Enxerto , Humanos , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Procedimentos de Cirurgia Plástica/métodos , Estudos Retrospectivos , Resultado do Tratamento , Vasoconstritores/uso terapêutico
4.
J Craniofac Surg ; 33(4): 1028-1031, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36041102

RESUMO

BACKGROUND: Complete naso-orbital-ethmoid (NOE) complex fractures including hollow space defects are difficult to treat. A proper bone fragment should be maintained for bony rearrangement and reconstruction; however, no guidelines are available for the treatment of the NOE complex. In patients with empty bone fragment from NOE fractures, implantation of autologous rib grafts may be an option for recreating the orbital rim. METHODS: A 57-year-old man with open complete NOE fracture. Computed tomography (CT) revealed complete loss of bone fragments within the NOE area, including the inferior orbital rim and maxillary wall. A bone was harvested from the right fifth rib. The grafted bone mimicked the inferomedial orbital rim and was stabilized with mid plates. RESULTS: Follow-up CT and three-dimensional (3D) volumetry were performed at 1, 3, 6, and 12 months. A well-positioned rib graft and orbital wall were observed. In 3D volumetry analysis, we noted that the absorption rate of the rib cartilage was 7.84% at 6 months. The absorption rate of rib cartilage was evaluated using CT images, which were reconstructed with a 3D image reconstruction program (Α-VIEW, Coreline soft, Seoul, Korea). CONCLUSIONS: Complete NOE fractures, especially fractures involving loss of the buttress for plating, may pose a burden to surgeons. In such cases, implantation of an autologous rib cartilage graft is a good option for bony frame reconstruction, without any concerns of bony resorption.


Assuntos
Cartilagem Costal , Traumatismos Faciais , Fraturas Orbitárias , Fratura da Base do Crânio , Fraturas Cranianas , Osso Etmoide/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Fraturas Orbitárias/diagnóstico por imagem , Fraturas Orbitárias/cirurgia , Costelas , Fraturas Cranianas/cirurgia
5.
Korean J Physiol Pharmacol ; 26(6): 501-509, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36302624

RESUMO

Irisin is a myokine caused by exercise that improves insulin resistance and weight loss. However, under unfavorable conditions such as air pollution, and during the pandemic, outdoor activities are uncomfortable. Therefore, in this study, the effect of heat therapy (half bath 42 ± 0.5°C for 30 min) on irisin circulation levels as an exercise alternative for middle-aged obese women after menopause was investigated. Subjects were 33 women aged 49.54 ± 6.04 years, with parameters of height, 160.12 ± 4.33 cm, weight, 69.71 ± 7.52 kg, body surface area 1.73 ± 0.13 m2, body mass index, 27.19 ± 3.40 kg/m2. The results suggest that circulating irisin levels showed a significant increase after one-time thermotherapy (TH-1). However, the increase in circulating irisin levels after 15 treatments (TH-15, 5 days/week, 3 weeks) was significantly varied. The level of adiponectin, which increases fatty oxidation to reduce fatty deposition, increased significantly at TH-1, but further increased at TH-15, which was significantly different from the level of TH-1. In addition, the basic serum free fatty acid (FFA) level was significantly increased at TH-15 compared to TH-1. Significant differences were also found in the lipid profile (body mass index, waist circumference, and % body fat). Thermotherapy can significantly increase the tympanic temperature and induce changes in circulating irisin and adiponectin levels. Thus, it resulted in positive changes in FFA and lipid profiles. Therefore, repeated thermotherapy is effective in increasing circulating irisin levels in postmenopausal obese women.

6.
Sensors (Basel) ; 21(2)2021 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-33440684

RESUMO

In order to utilize wave energy, various wave power systems are being actively researched and developed and interest in them is increasing. To maximize the operational efficiency, it is very important to monitor and maintain the fault of components of the system. In recent years, interest in the management cost, high reliability and facility utilization of such systems has increased. In this regard, fault diagnosis technology including fault factor analysis and fault reproduction is drawing attention as an important main technology. Therefore, in this study, to reproduce and monitor the faults of a wave power system, firstly, the failure mode of the system was analyzed using FMEA analysis. Secondly, according to the derived failure mode and effect, the thrust bearing was selected as a target for fault reproduction and a test equipment bench was constructed. Finally, with the vibration data obtained by conducting the tests, the vibration spectrum was analyzed to extract the features of the data for each operating status; the data was classified by applying the three machine learning algorithms: naïve Bayes (NB), k-nearest neighbor (k-NN), and multi-layer perceptron (MLP). The criteria for determining the fault were derived. It is estimated that a more efficient fault diagnosis is possible by using the standard and fault monitoring method of this study.

7.
Korean J Physiol Pharmacol ; 24(5): 385-394, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32830145

RESUMO

Eupatilin is known to possess anti-apoptotic, anti-oxidative, and antiinflammatory properties. We report here that eupatilin has a protective effect on the ethanol-induced injury in rats. Sprague-Dawley rats were divided into 6 groups: control, vehicle, silymarin, eupatilin 10 mg/kg, eupatilin 30 mg/kg, and eupatilin 100 mg/kg. Plasma levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were analyzed to determine the extent of liver damage. Total cholesterol (TC) and triglycerides (TG) were analyzed to determine the level of liver steatosis. Malondialdehyde level, superoxide dismutase (SOD) activity, and glutathione (GSH) level were analyzed to determine the extent of oxidative stress. Tumor necrosis factor (TNF)-α and interleukin (IL)-1ß were quantified to verify the degree of inflammation. Based on our findings, chronic alcohol treatment significantly changed the serum indexes and liver indicators of the model rats, which were significantly improved by eupatilin treatment. Rats in the eupatilin-treatment group showed reduced levels of AST, ALT, TG, TC, TNF-α, and IL-1ß, increased SOD activity and GSH levels, and improved overall physiology compared to the alcoholic liver disease model rats. H&E staining also verified the eupatilin-mediated improvement in liver injury. In conclusion, eupatilin inhibits alcohol-induced liver injury via its antioxidant and anti-inflammatory effects.

8.
Knee Surg Sports Traumatol Arthrosc ; 27(8): 2558-2567, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30406407

RESUMO

PURPOSE: To evaluate the postoperative size of discoid lateral meniscus using magnetic resonance imaging (MRI) after partial meniscectomy relative to the size of medial meniscus midbody. METHODS: This study included 48 patients who underwent arthroscopic partial meniscectomy with or without repair for symptomatic complete discoid meniscus. The intraoperative size of midbody of medial meniscus was used as a reference for partial meniscectomy. MRIs were performed pre- and postoperatively. Quantitative evaluations of the height, width, extrusion of the meniscus, and relative percentage of extrusion in the coronal and sagittal planes were completed. Demographic data, preoperative shift, type of shift, and operative technique were analyzed while considering the remaining meniscus. Logistic regression analyses were used. RESULTS: The mean remaining discoid meniscal width in the coronal plane of MRI was not significantly different from the width of midbody of medial meniscus (9.1 ± 4.2 mm vs. 9.4 ± 1.4 mm, n.s.) Absolute meniscal extrusion and relative percentage of extrusion in the coronal plane and the ratio of t meniscus in sagittal plane of the final MRI were significantly increased as compared with the preoperative MRI. Preoperative shift was a risk factor for the reduction of remaining meniscal width (odds ratio 11.997, p = 0.016, 95% CI 1.586-90.737). CONCLUSION: The size of midbody of medial meniscus could be a reference for partial meniscectomy in symptomatic complete discoid meniscus. Preoperative shift represents a risk factor for decreased remaining meniscal width. These findings could be helpful in ensuring appropriate surgical planning and explaining poor prognostic factors. LEVEL OF EVIDENCE: Prospective cohort study, Level II.


Assuntos
Meniscos Tibiais/cirurgia , Lesões do Menisco Tibial/cirurgia , Adulto , Estudos de Coortes , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Meniscectomia , Meniscos Tibiais/diagnóstico por imagem , Estudos Prospectivos , Valores de Referência , Lesões do Menisco Tibial/diagnóstico por imagem , Adulto Jovem
9.
Chin J Physiol ; 62(6): 279-284, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31793465

RESUMO

The aim of this study was to investigate the plasma dopamine and serum serotonin levels in humans with and without caffeine (CAFF) ingestion during treadmill running exercise. Thirty male volunteers participated in the randomized experiment involving two groups: CON (n = 15, 200 mL of tap water) versus CAFF (n = 15, 3 mg/kg CAFF and 200 mL tap water). After treadmill running, the dopamine level was significantly increased in the CAFF group (P < 0.01) and was significantly higher than in the CON group (P < 0.01). Serotonin was significantly increased in both groups after treadmill running (P < 0.05). However, serotonin levels showed no significant statistical difference between the groups. Prolactin and cortisol were significantly increased in both groups after treadmill running (P < 0.01). However, there was no significant statistical difference between groups. ß-endorphin level was significantly increased in the CAFF group at after treadmill running (P < 0.01) and was significantly higher than in CON after treadmill running (P < 0.01). In conclusion, 3 mg/kg CAFF ingestion before treadmill running stimulated dopamine release without inhibiting serotonin, which may reduce central fatigue.


Assuntos
Corrida , Cafeína , Dopamina , Teste de Esforço , Humanos , Masculino , Homens
10.
Korean J Physiol Pharmacol ; 23(4): 263-270, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31297010

RESUMO

Hydrogen sulfide is well-known to exhibit anti-inflammatory and cytoprotective activities, and also has protective effects in the liver. This study aimed to examine the protective effect of hydrogen sulfide in rats with hepatic encephalopathy, which was induced by mild bile duct ligation. In this rat model, bile ducts were mildly ligated for 26 days. Rats were treated for the final 5 days with sodium hydrosulfide (NaHS). NaHS (25 µmol/kg), 0.5% sodium carboxymethyl cellulose, or silymarin (100 mg/kg) was administered intraperitoneally once per day for 5 consecutive days. Mild bile duct ligation caused hepatotoxicity and inflammation in rats. Intraperitoneal NaHS administration reduced levels of aspartate aminotransferase and alanine aminotransferase, which are indicators of liver disease, compared to levels in the control mild bile duct ligation group. Levels of ammonia, a major causative factor of hepatic encephalopathy, were also significantly decreased. Malondialdehyde, myeloperoxidase, catalase, and tumor necrosis factor-α levels were measured to confirm antioxidative and anti-inflammatory effects. N-Methyl-D-aspartic acid (NMDA) receptors with neurotoxic activity were assessed for subunit NMDA receptor subtype 2B. Based on these data, NaHS is suggested to exhibit hepatoprotective effects and guard against neurotoxicity through antioxidant and anti-inflammatory actions.

11.
Small ; 14(8)2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29266730

RESUMO

Large-scale 2D single-crystalline copper nanoplates (Cu NPLs) are synthesized by a simple hydrothermal method. The combination of a mild reductant, stabilizer, and shape modifier allows the dimensional control of the Cu nanocrystals from 1D nanowires (NWs) to 2D nanoplates. High-resolution transmission electron microscopy (HR-TEM) reveals that the prepared Cu NPLs have a single-crystalline structure. From the X-ray photoelectron spectroscopy (XPS) analysis, it is found that iodine plays an important role in the modification of the copper nanocrystals through the formation of an adlayer on the basal plane of the nanoplates. Cu NPLs with an average edge length of 10 µm are successfully synthesized, and these Cu NPLs are the largest copper 2D crystals synthesized by a solution-based process so far. The application of the metallic 2D crystals as a semitransparent electrode proves their feasibility as a conductive filler, exhibiting very low sheet resistance (0.4 Ω â–«-1 ) compared to Cu NWs and a transmittance near 75%. The efficient charge transport is due to the increased contact area between each Cu NPL, i.e., so-called plane contact (2D electrical contact). In addition, this type of contact enhances the current-carrying capability of the Cu NPL electrodes, implying that the large-size Cu NPLs are promising conductive fillers for printable electrode applications.

12.
Nano Lett ; 17(12): 7462-7470, 2017 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-29182342

RESUMO

The controllability of switching conductive filaments is one of the central issues in the development of reliable metal-oxide resistive memory because the random dynamic nature and formation of the filaments pose an obstacle to desirable switching performance. Here, we introduce a simple and novel approach to control and form a single silicon nanocrystal (Si-NC) filament for use in SiOx memory devices. The filament is formed with a confined vertical nanoscale gap by using a well-defined single vertical truncated conical nanopore (StcNP) structure. The physical dimensions of the Si-NC filaments such as number, size, and length, which have a significant influence on the switching properties, can be simply engineered by the breakdown of an Au wire through different StcNP structures. In particular, we demonstrate that the designed SiOx memory junction with a StcNP of pore depth of ∼75 nm and a bottom diameter of ∼10 nm exhibited a switching speed of up to 6 ns for both set and reset process, significantly faster than reported SiOx memory devices. The device also exhibited a high ON-OFF ratio, multistate storage ability, acceptable endurance, and retention stability. The influence of the physical dimensions of the StcNP on the switching features is discussed based on the simulated temperature profiles of the Au wire and the nanogap size generated inside the StcNP structure during electromigration.

14.
Nanotechnology ; 28(14): 145602, 2017 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-28276339

RESUMO

A network structure consisting of nanomaterials with a stable structural support and charge path on a large area is desirable for various electronic and optoelectronic devices. Generally, network structures have been fabricated via two main strategies: (1) assembly of pre-grown nanostructures onto a desired substrate and (2) direct growth of nanomaterials onto a desired substrate. In this study, we utilized the surface defects of graphene to form a nano-network of ZnO via atomic layer deposition (ALD). The surface of pure and structurally perfect graphene is chemically inert. However, various types of point and line defects, including vacancies/adatoms, grain boundaries, and ripples in graphene are generated by growth, chemical or physical treatments. The defective sites enhance the chemical reactivity with foreign atoms. ZnO nanoparticles formed by ALD were predominantly deposited at the line defects and agglomerated with increasing ALD cycles. Due to the formation of the ZnO nano-network, the photocurrent between two electrodes was clearly changed under UV irradiation as a result of the charge transport between ZnO and graphene. The line patterned ZnO/graphene (ZnO/G) nano-network devices exhibit sensitivities greater than ten times those of non-patterned structures. We also confirmed the superior operation of a fabricated flexible photodetector based on the line patterned ZnO/G nano-network.

15.
Environ Sci Technol ; 51(11): 6044-6052, 2017 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-28462990

RESUMO

Sediment samples from the East China and Yellow seas collected adjacent to continental China were found to have lower δ15N values (expressed as δ15N = [15N:14Nsample/15N:14Nair - 1] × 1000‰; the sediment 15N:14N ratio relative to the air nitrogen 15N:14N ratio). In contrast, the Arctic sediments from the Chukchi Sea, the sampling region furthest from China, showed higher δ15N values (2-3‰ higher than those representing the East China and the Yellow sea sediments). Across the sites sampled, the levels of sediment δ15N increased with increasing distance from China, which is broadly consistent with the decreasing influence of anthropogenic nitrogen (NANTH) resulting from fossil fuel combustion and fertilizer use. We concluded that, of several processes, the input of NANTH appears to be emerging as a new driver of change in the sediment δ15N value in marginal seas adjacent to China. The present results indicate that the effect of NANTH has extended beyond the ocean water column into the deep sedimentary environment, presumably via biological assimilation of NANTH followed by deposition. Further, the findings indicate that NANTH is taking over from the conventional paradigm of nitrate flux from nitrate-rich deep water as the primary driver of biological export production in this region of the Pacific Ocean.


Assuntos
Monitoramento Ambiental , Sedimentos Geológicos , Nitrogênio , Regiões Árticas , China , Oceanos e Mares , Oceano Pacífico
16.
Surg Endosc ; 31(4): 1936-1946, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27553800

RESUMO

BACKGROUND: Subepithelial tumors (SETs) in the gastrointestinal tract are often incidentally found during endoscopic examinations. Although the utility and safety of endoscopic resection (ER) of SETs in the esophagus and stomach have been described, data about the ER of duodenal SETs remain scant. Therefore, we aimed to investigate the clinical outcomes associated with the ER of duodenal SETs and to assess possible predictive factors for incomplete resection. METHODS: We conducted a retrospective observational study of 62 patients (64 lesions) that underwent ER of duodenal SETs between June 2005 and December 2015 at the Pusan National University Hospital. The therapeutic outcomes from ER and procedure-related complications were analyzed. RESULTS: Endoscopic mucosal resection (EMR) was performed in 38 tumors, EMR with a ligation device (EMR-L) in 18 and endoscopic submucosal dissection (ESD) in 8. The overall en bloc resection and complete ER rates were 96.9 % (62/64) and 100 % (64/64), respectively. The complete pathologic resection rate was 76.6 % (49/64). Multivariate logistic regression analyses determined that the macroscopic type (Yamada type I or II; odds ratio [OR] 6.460, 95 % confidence interval [CI] 1.569-37.458, p = 0.027) and the treatment method (ESD; OR 7.178, 95 % CI 1.291-39.323, p = 0.024) were independently associated with incomplete pathologic resection. The procedure-related bleeding and perforation rates were 6.3 % and 4.7 %, respectively. No recurrences were observed in patients who had undergone complete ER at a median follow-up period of 20 months (range 6-112 months). CONCLUSION: ER is an effective, safe, and feasible treatment for duodenal SETs, especially when the SET is located in the deep mucosal layer and/or the submucosal layer.


Assuntos
Carcinoma/cirurgia , Neoplasias Duodenais/cirurgia , Ressecção Endoscópica de Mucosa/métodos , Endoscopia do Sistema Digestório/métodos , Lipoma/cirurgia , Recidiva Local de Neoplasia/epidemiologia , Tumores Neuroendócrinos/cirurgia , Complicações Pós-Operatórias/epidemiologia , Adulto , Idoso , Carcinoma/patologia , Neoplasias Duodenais/diagnóstico por imagem , Endossonografia , Feminino , Hemorragia Gastrointestinal/epidemiologia , Humanos , Perfuração Intestinal/epidemiologia , Lipoma/patologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Neoplasia Residual , Tumores Neuroendócrinos/patologia , Razão de Chances , Estudos Retrospectivos , Resultado do Tratamento
17.
Nanotechnology ; 27(14): 145204, 2016 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-26905768

RESUMO

A highly efficient solution-processible charge trapping medium is a prerequisite to developing high-performance organic nano-floating gate memory (NFGM) devices. Although several candidates for the charge trapping layer have been proposed for organic memory, a method for significantly increasing the density of stored charges in nanoscale layers remains a considerable challenge. Here, solution-processible graphene quantum dots (GQDs) were prepared by a modified thermal plasma jet method; the GQDs were mostly composed of carbon without any serious oxidation, which was confirmed by x-ray photoelectron spectroscopy. These GQDs have multiple energy levels because of their size distribution, and they can be effectively utilized as charge trapping media for organic NFGM applications. The NFGM device exhibited excellent reversible switching characteristics, with an on/off current ratio greater than 10(6), a stable retention time of 10(4) s and reliable cycling endurance over 100 cycles. In particular, we estimated that the GQDs layer trapped ∼7.2 × 10(12) cm(-2) charges per unit area, which is a much higher density than those of other solution-processible nanomaterials, suggesting that the GQDs layer holds promise as a highly efficient nanoscale charge trapping material.

18.
Int J Biometeorol ; 59(4): 473-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24865598

RESUMO

The purpose of this study was to determine whether repeated heat load is closely related to circulating levels of free fatty acids (FFA) during repeated passive heat loading (PHL), defined as immersion of the lower body up to an umbilical level in hot water, 42 ± 0.5 °C (three times/week, 30 min/day) for 2 weeks. There were significant correlations between mean body temperature and FFA before and after repeated heat load (p < 0.001, respectively), and the level of FFA was significantly higher after repeated heat load during PHL (p < 0.01). The threshold of mean body temperature for lipolysis was lowered by repeated heat load and enhanced lipolysis during PHL. However, caution is needed for diabetic individuals.


Assuntos
Temperatura Corporal/fisiologia , Ácidos Graxos não Esterificados/sangue , Resposta ao Choque Térmico/fisiologia , Calefação/métodos , Imersão/fisiopatologia , Ácidos Graxos não Esterificados/metabolismo , Humanos , Lipólise/fisiologia , Masculino , República da Coreia , Adulto Jovem
19.
Korean J Physiol Pharmacol ; 19(1): 9-14, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25605991

RESUMO

We investigated the sweating response during passive heating (partial submersion up to the umbilical line in 42±0.5℃ water, 30 min) after summer and winter seasonal acclimatization (SA). Testing was performed in July during the summer, 2011 [summer-SA; temp, 25.6±1.8℃; relative humidity (RH), 82.1±8.2%] and in January during the winter, 2012 (winter-SA; temp, -2.7±2.9℃; RH, 65.0±13.1%) in Cheonan (126°52'N, 33.38'E), Republic of Korea. All experiments were carried out in an automated climatic chamber (temp, 25.0±0.5℃: RH, 60.0±3.0%). Fifteen healthy men (age, 23.4±2.5 years; height, 175.0±5.9 cm; weight, 65.3±6.1 kg) participated in the study. Local sweat onset time was delayed during winter-SA compared to that after summer-SA (p< 0.001). Local sweat volume, whole body sweat volume, and evaporative loss volume decreased significantly after winter-SA compared to those after summer-SA (p<0.001). Changes in basal metabolic rate increased significantly after winter-SA (p< 0.001), and tympanic temperature and mean body temperature were significantly lower after summer-SA (p<0.05). In conclusion, central sudomotor acitivity becomes sensitive to summer-SA and blunt to winter-SA in Rebubic of Korea. These results suggest that the body adjusts its temperature by economically controlling the sweating rate but does not lower the thermal dissipation rate through a more effective evaporation scheme after summer-SA than that after winter-SA.

20.
J Therm Biol ; 45: 163-7, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25436966

RESUMO

There is relativley little information on the serum biomarkers of heat stress. Therefore, the goal of this study was to verify the effect of passive heat loading (PHL) on the expression of fibroblast growth factor-21 (FGF21) and free fatty acids (FFAs). Four PHL protocols based on intensity (39 °C vs. 43 °C, leg immersion, 30 min) and type (leg vs. half immersion, 42 °C, 30 min) were used. Each protocol was applied on a 2 day cycle to 12 healthy adult males (age, 22.4 ± 2.9 years; height, 174.1 ± 4.6 cm; weight, 71.3 ± 5.6 kg; body mass index, 23.1 ± 3.0). The subjects were categorized into two groups according to the study design (randomized, with a parallel trial). Body temperature, FGF21 and FFAs were determined prior to PH L, immediately and 60 min after PHL. Body temperature was significant higher (43 °C) than the 39 °C measured under identical PHL type (leg immersion). PHL was effective for the expression of FGF21 and for lipolysis. The quantitative levels of FGF21 and FFA increased with increasing temperature (39 °C<42 °C<43 °C). A significant difference in the quantitative levels of FGF21 and FFAs was also evident based on the type of PHL (leg

Assuntos
Fatores de Crescimento de Fibroblastos/sangue , Resposta ao Choque Térmico , Temperatura Alta , Lipólise , Adulto , Temperatura Corporal , Ácidos Graxos não Esterificados/sangue , Humanos , Imersão , Masculino , Água
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