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1.
Nanoscale Res Lett ; 14(1): 375, 2019 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-31832795

RESUMO

In this work, a high-density hydrogen (HDH) treatment is proposed to reduce interface traps and enhance the efficiency of the passivated emitter rear contact (PERC) device. The hydrogen gas is compressed at pressure (~ 70 atm) and relatively low temperature (~ 200 °C) to reduce interface traps without changing any other part of the device's original fabrication process. Fourier-transform infrared spectroscopy (FTIR) confirmed the enhancement of Si-H bonding and secondary-ion mass spectrometry (SIMS) confirmed the SiN/Si interface traps after the HDH treatment. In addition, electrical measurements of conductance-voltage are measured and extracted to verify the interface trap density (Dit). Moreover, short circuit current density (Jsc), series resistance (Rs), and fill factor (F.F.) are analyzed with a simulated light source of 1 kW M-2 global AM1.5 spectrum to confirm the increase in cell efficiency. External quantum efficiency (EQE) is also measured to confirm the enhancement in conversion efficiency between different wavelengths. Finally, a model is proposed to explain the experimental result before and after the treatment.

2.
J Clin Med ; 8(12)2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31816820

RESUMO

Aim: This study aimed to compare mortality risks across uric acid (UA) levels between non-diabetes adults and participants with diabetes and to investigate the association between hyperuricemia and mortality risks in low-risk adults. Methods: We analyzed data from adults aged >18 years without coronary heart disease and chronic kidney disease (n = 29,226) from the National Health and Nutrition Examination Survey (1999-2010) and the associated mortality data (up to December 2011). We used the Cox proportional hazards models to examine the risk of all-cause and cause-specific (cardiovascular disease (CVD) and cancer) mortality at different UA levels between adults with and without diabetes. Results: Over a median follow-up of 6.6 years, 2069 participants died (495 from CVD and 520 from cancers). In non-diabetes adults at UA ≥ 5 mg/dL, all-cause and CVD mortality risks increased across higher UA levels (p-for-trend = 0.037 and 0.058, respectively). The lowest all-cause mortality risk in participants with diabetes was at the UA level of 5-7 mg/dL. We set the non-diabetes participants with UA levels of <7 mg/dL as a reference group. Without considering the effect of glycemic control, the all-cause mortality risk in non-diabetes participants with UA levels of ≥7 mg/dL was equivalent to risk among diabetes adults with UA levels of <7 mg/dL (hazard ratio = 1.44 vs. 1.57, p = 0.49). A similar result was shown in CVD mortality risk (hazard ratio = 1.80 vs. 2.06, p = 0.56). Conclusion: Hyperuricemia may be an indicator to manage multifaceted cardiovascular risk factors in low-risk adults without diabetes, but further studies and replication are warranted.

3.
ACS Appl Mater Interfaces ; 11(43): 40196-40203, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31573173

RESUMO

In this study, the impact of moisture on the electrical characteristics of an amorphous In-Ga-Zn-O thin-film transistor (a-IGZO TFT) was investigated. In commercial applications of such TFTs, high stability and quality performance in humid environments are essential. During TFT operation under ambient moisture, the electrolysis of water molecules occurs via the tip electric field effect. Hydrogen diffuses from the etch-stop layer or back-channel into the main channel under a negative electric field. The hydrogen atoms act as shallow donors (which causes the carrier concentration in the channel to rise), causing the threshold voltage (VTH) to shift in the negative direction. Hydrogen diffusion from the overlap of the source/drain and gate electrodes to the channel center caused by the tip electric field induces a significant barrier lowering and VTH shifts in a short-channel device. However, under negative bias stress (NBS) in ambient moisture, the negative VTH shift is more obvious in short- than in long-channel devices, indicating suppressed hydrogen diffusion in long-channel devices. This is attributed to the electrolysis of water by the tip electric field at the source, drain, and gate electrodes, which causes hydrogen to diffuse to the center of the channel. Here, a novel physical model of the capacitance-voltage (C-V) electrical property changes under ambient moisture is proposed, based on the early appearance of abnormalities in the C-V measurements. The electrolysis of water caused by the tip electric field and electrical abnormalities caused by hydrogen diffusion into the a-IGZO active layer are explained by this model. A secondary-ion mass spectrometry analysis shows that hydrogen content in the channel generally increases under NBS in ambient moisture. The degradation behavior due to moisture in a-IGZO is clarified. Thus, inhibiting the tip electric field may benefit future flexible-display and gas-sensing applications.

4.
Sci Rep ; 9(1): 3654, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30842539

RESUMO

In this study, we demonstrated a blue phosphorescent organic light-emitting diode (BPOLED) based on a host with two carbazole and one trizole (2CbzTAZ) moiety, 9,9'-(2-(4,5-diphenyl-4H-1,2,4-triazol-3-yl)-1,3-phenylene)bis(9H-carbazole), that exhibits bipolar transport characteristics. Compared with the devices with a carbazole host (N,N'-dicarbazolyl-3,5-benzene, (mCP)), triazole host (3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, (TAZ)), or a physical mixture of mCP:TAZ, which exhibit hole, electron, and bipolar transport characteristics, respectively, the BPOLED with the bipolar 2CbzTAZ host exhibited the lowest driving voltage (6.55 V at 10 mA/cm2), the highest efficiencies (maximum current efficiency of 52.25 cd/A and external quantum efficiency of 23.89%), and the lowest efficiency roll-off, when doped with bis[2-(4,6-difluorophenyl)pyridinato-C2,N](picolinato)iridium(III) (FIrpic) as blue phosphor. From analyses of light leakage of the emission spectra of electroluminescence, transient electroluminescence, and partially doped OLEDs, it was found that the recombination zone was well confined inside the emitting layer and the recombination rate was most efficient in a 2CbzTAZ-based OLED. For the other cases using mCP, TAZ, and mCP:TAZ as hosts, electrons and holes transported with different routes that resulted in carrier accumulation on different organic molecules and lowered the recombination rate.

5.
Molecules ; 23(10)2018 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-30301176

RESUMO

Fifty-seven compounds were purified from the stems of Tinospora sinensis, including three new compounds characterized as a lignan (1), a pyrrole alkaloid (11), and a benzenoid (17), respectively. Their structures were elucidated and established by various spectroscopic and spectrometric analytical methods. Among the isolates, fifteen compounds were examined for their anti-inflammatory potential in vitro. The results showed that several compounds displayed moderate inhibition of N-formyl-methionyl-leucyl-phenylalanine/cytochalasin B (fMLP/CB)-induced superoxide anion generation and elastase release.


Assuntos
Alcaloides/farmacologia , Lignanas/farmacologia , Elastase Pancreática/metabolismo , Pirróis/farmacologia , Alcaloides/química , Citocalasina B/antagonistas & inibidores , Citocalasina B/toxicidade , Humanos , Lignanas/química , Estrutura Molecular , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Elastase Pancreática/biossíntese , Elastase Pancreática/efeitos dos fármacos , Caules de Planta/química , Pirróis/química , Superóxidos/antagonistas & inibidores , Superóxidos/toxicidade , Tinospora/química
6.
Curr Med Res Opin ; 34(11): 1885-1892, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29429368

RESUMO

OBJECTIVE: To investigate the effects of statins on all-cause mortality risk at different low-density lipoprotein cholesterol (LDL-C) levels, and to compare the mortality risk between statin users and non-users with identical LDL-C levels in a type 2 diabetes cohort. METHODS: In total, 10,582 outpatients aged ≥18 years with type 2 diabetes mellitus (T2DM) between 2009 and 2012 were enrolled in this retrospective cohort study in central Taiwan. All-cause mortality events were followed up until the end of 2014. According to the medical records during the follow-up period, the patients were classified into statin (+) and statin (-) groups. Patients were categorized into different LDL-C segments based on their mean LDL-C levels during the 2.8-year follow-up. RESULTS: Non-cardiovascular mortality accounted for more than half the deaths. Overall, statin therapy significantly reduced the all-cause mortality risk in both univariable and multivariable models (hazard ratios = 0.39 and 0.38, respectively). Sub-group analyses showed that the lowest mortality risk occurred in the 80-89 mg/dL segment in the statin (-) group and in the 90-99 mg/dL segment in the statin (+) group. Statin therapy significantly reduced the mortality risk at all LDL-C levels except for low LDL-C (<60 mg/dL). CONCLUSIONS: In addition to reducing LDL-C levels, statin therapy reduced all-cause mortality risk in Taiwanese patients with T2DM. Statins further reduced the mortality risk at most LDL levels. However, at low LDL-C levels, the positive effects of statins may have been nullified.


Assuntos
LDL-Colesterol/sangue , Diabetes Mellitus Tipo 2 , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipidemias , Adulto , Idoso , Grupo com Ancestrais do Continente Asiático/estatística & dados numéricos , Estudos de Coortes , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/mortalidade , Feminino , Humanos , Hiperlipidemias/sangue , Hiperlipidemias/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Mortalidade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Taiwan/epidemiologia
7.
Nanoscale ; 9(25): 8586-8590, 2017 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-28636031

RESUMO

This study proposes a method for a HfO2-based device to exhibit both resistive switching (RS) characteristics as resistive random access memory (RRAM) and selector characteristics by introducing vanadium (V) as the top electrode. This simple V/HfO2/TiN structure can demonstrate these two different properties depending on forming polarities. The RS mechanism is activated by a positive forming bias. In contrast, the selector property is induced by a negative forming bias. The material analyses firstly confirm the existence of V in the top electrode. Then the electrical measurements for the same V/HfO2/TiN structures but with different forming polarities were carried out to further investigate their DC sweeping characteristics to act as either a selector or RRAM device. Furthermore, reliability tests for both selector and RRAM devices were also conducted to confirm their switching stabilities. Finally, current fitting methods and temperature influence experiments were performed to investigate the carrier transport mechanisms. Finally, physical models were proposed to illustrate the selector property and RS mechanism for selector and RRAM devices, respectively. This simple device structure with its easy operating method accomplishes a significant advancement of devices combining both selector properties and RRAM for remarkable real applications in the near future.

8.
ACS Appl Mater Interfaces ; 9(12): 10788-10797, 2017 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-28225260

RESUMO

The atomic layer deposition (ALD) technique is applied to coat Ag nanowires (NWs) with a highly uniform and conformal TiO2 layer to improve the stability and sustainability of Ag NW transparent conductive films (TCFs) at high temperatures. The TiO2 layer can be directly deposited on Ag NWs with a surface polyvinylpyrrolidone (PVP) coat that acts a bed for TiO2 seeding in the ALD process. The ALD TiO2 layer significantly enhances the thermal stability at least 100 fold when aged between 200-400 °C and also provides an extra function of violet-blue light filtration for Ag NW TCFs. Investigation into the interaction between TiO2 and Ag reveals that the conformal TiO2 shell could effectively prevent Ag from 1D-to-3D ripening. However, Ag could penetrate the conformal TiO2 shell and form nanocrystals on the TiO2 shell surface when it is aged at 400 °C. According to experimental data and thermodynamic evaluation, the Ag penetration leads to an interlayer composed of mixed Ag-Ag2O-amorphous carbon phases and TiO2-x at the Ag-TiO2 interface, which is thought to be caused by extremely high vapor pressure of Ag at the Ag-TiO2 interface at a higher temperature (e.g., 400 °C).

9.
ACS Appl Mater Interfaces ; 9(3): 3149-3155, 2017 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-28072511

RESUMO

In this study, an O2 inductively coupled plasma (ICP) treatment was developed in order to modify the characteristics of indium tin oxide (ITO) film for use as an insulator in resistive random access memory (RRAM). After the O2 plasma treatment, the previously conductive ITO film is oxidized and becomes less conductive. In addition, after capping the same ITO material for use as a top electrode, we found that the ITO/ITO(O2 plasma)/TiN device exhibits very stable and robust resistive switching characteristics. On the contrary, the nontreated ITO film for use as an insulator in the ITO/ITO/TiN device cannot perform resistance switching behaviors. The material analysis initially investigated the ITO film characteristics with and without O2 plasma treatment. The surface was less rough after O2 plasma treatment. However, the molar concentration of each element and measured sheet resistance results for the O2-plasma-treated ITO film were dramatically modified. Next, electrical measurements were carried out to examine the resistance switching stability under continuous DC and AC operation in this ITO/ITO(O2 plasma)/TiN device. Reliability tests, including endurance and retention, also proved its capability for use in data storage applications. In addition to these electrical measurements, current fitting method experiments at different temperatures were performed to examine and confirm the resistance switching mechanisms. This easily fabricated device, using a simple material combination, achieves excellent performance by using ITO with an O2 plasma treatment and can further the abilities of RRAM for use in remarkable potential applications.

10.
Endocr Pract ; 20(12): e256-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25148817

RESUMO

OBJECTIVE: Fasting hypoglycemia may occur in subjects with systemic lupus erythematosus (SLE) when accompanied with insulin-binding antibodies or insulin-receptor antibodies. However, insulinoma has not been reported in SLE subjects with hypoglycemia. METHODS: We present a case report and review the relevant literature. RESULTS: A 26-year-old female with underlying SLE experienced several episodes of neuropsychiatric symptoms in a fasting state. The steroid dosage was titrated up, but in vain. Timely imaging studies showed a pancreatic tumor, and insulinoma was proven by pathology. Hypoglycemia did not recur after surgery. CONCLUSION: Physicians should distinguish insulinoma from autoimmunity-mediated hypoglycemia in SLE patients with fasting hypoglycemia.

11.
Diabetol Metab Syndr ; 6: 68, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24932223

RESUMO

BACKGROUND: This study aimed to explore parameters which will predict good control of HbA1c after adding a second anti-diabetic drug in patients with type 2 diabetes mellitus (T2DM) inadequately controlled with metformin monotherapy. METHODS: Fifty-one patients (M/F: 25/26, mean age: 53.7 ± 8.2 years, mean glycated hemoglobin [HbA1c] 8.4 ± 1.2%) with T2DM inadequately controlled with metformin were randomized to add-on glibenclamide or acarbose for 16 weeks. Before and after combination therapy, the subjects underwent a 2-hour liquid mixed meal tolerance test to determine insulin secretion (HOMA-ß, insulinogenic index, and disposition index [DI]) and insulin sensitivity (HOMA-IR and Matsuda insulin sensitivity index). RESULTS: At baseline, there was a significant inverse relationship between DI120 and HbA1c (p = 0.001) in all subjects. The addition of glibenclamide and acarbose improved HbA1c significantly from 8.6 ± 1.6% to 7.4 ± 1.2% (p < 0.001), and from 8.2 ± 0.8% to 7.5 ± 0.8% (p < 0.001), respectively. In the glibenclamide group, DI120 significantly increased from 51.2 ± 24.2 to 74.9 ± 41.9 (p < 0.05), and in the acarbose group, from 62.5 ± 31.4 to 91.7 ± 36.2 (p < 0.05), respectively. Multiple regression analyses showed that both baseline HbA1c and DI120 independently predicted reduction of HbA1c as well as final HbA1c after combination therapy. CONCLUSIONS: In patients with T2DM inadequately controlled with metformin, add-on oral anti-diabetic agent with glibenclamide or acarbose resulted in the significant HbA1c reduction and improvement of ß-cell function. Subjects with greater baseline ß-cell function reserve displayed better glycemic response in the combination therapy of metformin with glibenclamide or acarbose. TRIAL REGISTRATION: This study was registered in the ClinicalTrials.gov with registration number of NCT00417729.

12.
Chem Commun (Camb) ; 50(33): 4379-82, 2014 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-24643760

RESUMO

A Pt@TiO2@AAO membrane nanoreactor was fabricated by atomic layer deposition. The photodegradation test of methylene blue demonstrated that the nanoreactor shows efficient photocatalysis performance. It exhibited ~28% photodegradation of methylene blue after ten flow-through cycles, corresponding to about 2.7 × 10(-2) s of contact time of methylene blue with Pt@TiO2 nanotubes.

13.
PLoS One ; 8(6): e65853, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23776557

RESUMO

Cd(2+) causes damages to several human tissues. Although the toxicological and carcinogenetic mechanisms of Cd(2+) have been previously established, some basic questions on this toxicant remain unclear. In this study, we constructed Met-cad 1.57, a new fluorescent resonance energy transfer (FRET)-based Cd(2+) indicator, which contains a portion of a Cd(2+)-binding protein (CadR) obtained from Pseudomonas putida as the Cd(2+) sensing key. We produced a human embryonic kidney cell line HEK-MCD157 which stably expresses the Met-cad 1.57 for further investigations. Both fluorescence spectroscopy and FRET microscopic ratio imaging were used to monitor the Cd(2+) concentration within the living HEK-MCD157 cells. The dissociation constant of Met-cad 1.57 was approximately 271 nM. The function of Ca(2+) channels as a potential Cd(2+) entry gateway was further confirmed in the HEK-MCD157 cells. The organelle-targeted property of the protein-based Cd(2+) indicator directly reveals the nucleus accumulation phenomena. In summary, a human kidney cell line that stably expresses the FRET-based Cd(2+) indicator Met-cad 1.57 was constructed for reliable and convenient investigations to determine the Cd(2+) concentration within living cells, including the identification of the entry pathway of Cd(2+) and sub-cellular sequestration.


Assuntos
Cádmio/metabolismo , Transferência Ressonante de Energia de Fluorescência , Proteínas de Bactérias/metabolismo , Linhagem Celular , Núcleo Celular/metabolismo , Humanos , Espectrometria de Fluorescência , Fatores de Transcrição/metabolismo
14.
Opt Express ; 21(24): 30065-73, 2013 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-24514556

RESUMO

This paper demonstrates that quantum-confined Stark effect (QCSE) within the multiple quantum wells (MQWs) can be suppressed by the growths of InGaN-based light-emitting diodes (LEDs) on the nano-sized patterned c-plane sapphire substrates (PCSSs) with reducing the space. The efficiency droop is also determined by QCSE. As verified by the experimentally measured data and the ray-tracing simulation results, the suppressed efficiency droop for the InGaN-based LED having the nano-sized PCSS with a smaller space of 200 nm can be acquired due to the weaker function of the QCSE within the MQWs as a result of the smaller polarization fields coming from the lower compressive strain in the corresponding epitaxial layers.

15.
Chang Gung Med J ; 33(6): 699-705, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-21199616

RESUMO

The conventional approach in orthodontic surgery treatment of dentofacial anomalies requires a varied period of pre-surgical orthodontic treatment. This presurgical period is considered to be important for adequate surgical treatment and stable results. This period is usually long bothersome for patients because dental decompensation is required and there is consequent deterioration of aesthetics and function, especially in cases of skeletal Class III occlusion. At Chang Gung Craniofacial Center, a surgery-first approach (SFA), i.e. minimal pre-surgical orthodontics, is one of the treatment choices for Class III patients. In this report, we present a 19-year-old man with mandibular prognathism, an anterior open bite and severe dental crowding treated with SFA. The patient received orthognathic surgery a week after bracing of the teeth. The operation and recovery were uneventful as well as the following orthodontic treatment. The total treatment time was only four months, much shorter than with the conventional approach. The patient benefitted from immediate improvement of the facial profile after surgery, and a much shorter total treatment, and the results were not compromised. We believe in selected cases, SFA is a good and effective treatment alternative.


Assuntos
Prognatismo/cirurgia , Humanos , Masculino , Ortodontia Corretiva , Adulto Jovem
16.
Am J Orthod Dentofacial Orthop ; 131(3): 352-6, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17346590

RESUMO

INTRODUCTION: The purpose of this study was to measure the thickness of the infrazygomatic (IZ) crest above the maxillary first molar at different angles and positions to the maxillary occlusal plane. These measurements were then used to derive clinical implications and guidance for inserting miniscrews in the IZ crest without injuring the mesiobuccal root of the maxillary first molar. METHODS: Computed tomographic images of 16 adults were used. For each subject, on the coronal slice of the computed tomographic image containing the IZ crest and mesiobuccal root of the maxillary first molar, the IZ crest thickness and the miniscrew insertion position were measured by postulating that the miniscrew would be inserted at each 5 degrees increment from 40 degrees to 75 degrees to the maxillary occlusal plane. RESULTS: The IZ crest thickness above the maxillary first molar ranged from 5.2 +/- 1.1 mm to 8.8 +/- 2.3 mm, measured at 40 degrees to 75 degrees to the maxillary occlusal plane and 13 to 17 mm above the maxillary occlusal plane. CONCLUSIONS: By adopting 6 mm as the minimal IZ crest thickness for sustaining a miniscrew well throughout treatment and avoiding injury to the mesiobuccal root of the maxillary first molar, the clinical implication for miniscrew placement in the IZ crest of an adult is to insert it 14 to 16 mm above the maxillary occlusal plane and the maxillary first molar at an angle of 55 degrees to 70 degrees to the maxillary occlusal plane.


Assuntos
Parafusos Ósseos , Dente Molar/diagnóstico por imagem , Zigoma/anatomia & histologia , Adulto , Cefalometria , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Tomografia Computadorizada por Raios X , Raiz Dentária/diagnóstico por imagem , Zigoma/diagnóstico por imagem
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