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1.
Nanoscale Adv ; 5(5): 1405-1415, 2023 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-36866260

RESUMO

Using DFT, the electronic structure, optical, and photocatalytic properties of PN (P = Ga, Al) and M2CO2 (M = Ti, Zr, Hf) monolayers and their PN-M2CO2 van der Waals heterostructures (vdWHs) are investigated. Optimized lattice parameters, bond length, bandgap, conduction and valence band edges show the potential of PN (P = Ga, Al) and M2CO2 (M = Ti, Zr, Hf) monolayers in photocatalytic applications, and the application of the present approach to combine these monolayers and form vdWHs for efficient electronic, optoelectronic and photocatalytic applications is shown. Based on the same hexagonal symmetry and experimentally achievable lattice mismatch of PN (P = Ga, Al) with M2CO2 (M = Ti, Zr, Hf) monolayers, we have fabricated PN-M2CO2 vdWHs. Binding energies, interlayer distance and AIMD calculations show the stability of PN-M2CO2 vdWHs and demonstrate that these materials can be easily fabricated experimentally. The calculated electronic band structures show that all the PN-M2CO2 vdWHs are indirect bandgap semiconductors. Type-II[-I] band alignment is obtained for GaN(AlN)-Ti2CO2[GaN(AlN)-Zr2CO2 and GaN(AlN)-Hf2CO2] vdWHs. PN-Ti2CO2 (PN-Zr2CO2) vdWHs with a PN(Zr2CO2) monolayer have greater potential than a Ti2CO2(PN) monolayer, indicating that charge is transfer from the Ti2CO2(PN) to PN(Zr2CO2) monolayer, while the potential drop separates charge carriers (electron and holes) at the interface. The work function and effective mass of the carriers of PN-M2CO2 vdWHs are also calculated and presented. A red (blue) shift is observed in the position of excitonic peaks from AlN to GaN in PN-Ti2CO2 and PN-Hf2CO2 (PN-Zr2CO2) vdWHs, while significant absorption for photon energies above 2 eV for AlN-Zr2CO2, GaN-Ti2CO2 and PN-Hf2CO2, give them good optical profiles. The calculated photocatalytic properties demonstrate that PN-M2CO2 (P = Al, Ga; M = Ti, Zr, Hf) vdWHs are the best candidates for photocatalytic water splitting.

2.
Nanoscale Adv ; 5(6): 1816, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36926571

RESUMO

[This corrects the article DOI: 10.1039/D3NA00017F.].

3.
Eur Rev Med Pharmacol Sci ; 25(16): 5145-5152, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34486689

RESUMO

OBJECTIVE: This study aims to construct a prediction model based on non-invasive examination and cardiovascular risk factors, to predict the presence of coronary artery disease (CAD) and its severity in patients with low-risk unstable angina pectoris (UAP)/Non-ST Segment Elevation Myocardial Infarction (NSTEMI). PATIENTS AND METHODS: This cross-sectional study aimed to assess the association between non-invasive examinations and cardiovascular risk factors in predicting CAD. Model constructed based on non-invasive assessment and cardiovascular risk factors was compared to coronary angiography, the reference standard. RESULTS: This study included 104 patients, comprising 60 men and 44 women, who fulfilled the inclusion criteria. The mean age was 52.3 (6.8) years. Two diagnostic prediction models were constructed after series of analyses. The main model consists of NO, CIMT, history of smoking, and Age-Gender, while the alternative model consists of CIMT, history of smoking, and Age-Gender. The main model has AUC of 74.5% (95% CI: 64.9-84.1), sensitivity of 72.7% (95% CI: 57.2-85.0), specificity 65.0% (95% CI: 51.6 -76.9 for a cut-off point of 74.5. While the alternative model has 69.0% AUC (95% CI: 58.9-79.1), sensitivity of 65.9% (95%: 50.1-79, 5), a specificity of 56.7% (95% CI: 43.2-69.4) for a cut-off point of 69. The main model and the alternative model have similar diagnostic prediction performance based on the ROC comparison test (p = 0.70). CONCLUSIONS: Based on these results, we conclude that NO, CIMT, smoking history, and age-gender have a value of diagnostic validity in subjects with low-risk UAP/NSTEMI.


Assuntos
Angina Instável/epidemiologia , Doença da Artéria Coronariana/diagnóstico , Infarto do Miocárdio sem Supradesnível do Segmento ST/epidemiologia , Fatores Etários , Angiografia Coronária , Doença da Artéria Coronariana/epidemiologia , Doença da Artéria Coronariana/fisiopatologia , Estudos Transversais , Feminino , Fatores de Risco de Doenças Cardíacas , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Óxido Nítrico/metabolismo , Gravidade do Paciente , Sensibilidade e Especificidade , Fatores Sexuais
4.
RSC Adv ; 12(1): 42-52, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-35424496

RESUMO

Using density functional (DFT) theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M2CO2 (M = Ti, Zr, Hf) monolayers and their corresponding BSe-M2CO2 (M = Ti, Zr, Hf) van der Waals (vdW) heterostructures. Optimized lattice constant, bond length, band structure and bandgap values, effective mass of electrons and holes, work function and conduction and valence band edge potentials of BSe and M2CO2 (M = Ti, Zr, Hf) monolayers are in agreement with previously available data. Binding energies, interlayer distance and Ab initio molecular dynamic simulations (AIMD) calculations show that BSe-M2CO2 (M = Ti, Zr, Hf) vdW heterostructures are stable with specific stacking and demonstrate that these heterostructures might be synthesized in the laboratory. The electronic band structure shows that all the studied vdW heterostructures have indirect bandgap nature - with the CBM and VBM at the Γ-K and Γ-point of BZ for BSe-Ti2CO2, respectively; while for BSe-Zr2CO2 and BSe-Hf2CO2 vdW heterostructures the CBM and VBM lie at the K-point and Γ-point of BZ, respectively. Type-II band alignment in BSe-M2CO2 (M = Ti, Zr, Hf) vdW heterostructures prevent the recombination of electron-hole pairs, and hence are crucial for light harvesting and detection. Absorption spectra are investigated to understand the optical behavior of BSe-M2CO2 (M = Ti, Zr, Hf) vdW heterostructures, where the lowest energy transitions are dominated by excitons. Furthermore, BSe-M2CO2 (M = Ti, Zr, Hf) vdW heterostructures are found to be potential photocatalysts for water splitting at pH = 0, and exhibit enhanced optical properties in the visible light zones.

5.
Sensors (Basel) ; 16(12)2016 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-27929450

RESUMO

An inkjet-printed, fully passive sensor capable of either humidity or gas sensing is presented herein. The sensor is composed of an interdigitated electrode, a customized printable gas sensitive ink and a specialized dipole antenna for wireless sensing. The interdigitated electrode printed on a paper substrate provides the base conductivity that varies during the sensing process. Aided by the porous nature of the substrate, a change in relative humidity from 18% to 88% decreases the electrode resistance from a few Mega-ohms to the kilo-ohm range. For gas sensing, an additional copper acetate-based customized ink is printed on top of the electrode, which, upon reaction with hydrogen sulphide gas (H2S) changes, both the optical and the electrical properties of the electrode. A fast response time of 3 min is achieved at room temperature for a H2S concentration of 10 ppm at a relative humidity (RH) of 45%. The passive wireless sensing is enabled through an antenna in which the inner loop takes care of conductivity changes in the 4-5 GHz band, whereas the outer-dipole arm is used for chipless identification in the 2-3 GHz band.

6.
Nicotine Tob Res ; 16(4): 413-22, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24174612

RESUMO

INTRODUCTION: Despite decades of tobacco use decline among the general population in the United States, tobacco use among low-income populations continues to be a major public health concern. Smoking rates are higher among individuals with less than a high school education, those with no health insurance, and among individuals living below the federal poverty level. Despite these disparities, smoking cessation treatments for low-income populations have not been extensively tested. In the current study, the efficacy of 2 adjunctive smoking cessation interventions was evaluated among low-income smokers who were seen in a primary care setting. METHODS: A total of 846 participants were randomly assigned either to motivational enhancement treatment plus brief physician advice and 8 weeks of nicotine replacement therapy (NRT) or to standard care, which consisted of brief physician advice and 8 weeks of NRT. Tobacco smoking abstinence was at 1, 2, 6, and 12 months following baseline. RESULTS: The use of the nicotine patch, telephone counseling, and positive decisional balance were predictive of increased abstinence rates, and elevated stress levels and temptation to smoke in both social/habit and negative affect situations decreased abstinence rates across time. Analyses showed intervention effects on smoking temptations, length of patch use, and number of telephone contacts. Direct intervention effects on abstinence rates were not significant, after adjusting for model predictors and selection bias due to perirandomization attrition. CONCLUSIONS: Integrating therapeutic approaches that promote use of and adherence to medications for quitting smoking and that target stress management and reducing negative affect may enhance smoking cessation among low-income smokers.


Assuntos
Motivação , Abandono do Hábito de Fumar/métodos , Fumar/tratamento farmacológico , Dispositivos para o Abandono do Uso de Tabaco , Adulto , Aconselhamento , Feminino , Promoção da Saúde/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Nicotina/administração & dosagem , Pobreza , Fumar/psicologia , Tabagismo/tratamento farmacológico , Tabagismo/psicologia , Estados Unidos
8.
Lancet ; 356(9229): 556-61, 2000 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-10950233

RESUMO

BACKGROUND: Inhaled corticosteroids are currently the cornerstone of asthma treatment. Some studies of high-dose fluticasone propionate in patients with no or mild asthma have, however, suggested substantial systemic absorption. We investigated the pharmacokinetics of fluticasone propionate in patients with asthma receiving appropriate doses for severity. METHODS: We did a double-blind, randomised, crossover study in 11 patients with asthma and 13 matched healthy controls (age 20-65 years; asthma patients forced expiratory volume in 1 s <75% and stable on high-dose inhaled corticosteroids). Patients received one 1000 microg intravenous dose or 1000 microg daily for 7 days inhaled (via spacer device) fluticasone propionate. In the 12 h after dosing, we monitored plasma fluticasone propionate and cortisol concentrations by mass spectrometry and competitive immunoassay with use of direct chemiluminescence. Analysis was by intention to treat. FINDINGS: After inhalation, geometric mean values were significantly lower in the asthma group than in controls for fluticasone propionate plasma area under curve (1082 [95% CI 850-1451] vs 2815 pg mL(-1) h(-1) [2262-3949], -62% difference [45-72]; p<0.001), maximum concentrations (117 [91-159] vs 383 pg/mL [302-546], -68% [-50 to -81]; p<0.001), and systemic bioavailability (10.1 [7.9-14.0] vs 21.4% [15.4-32.2], -54% [-27 to -70]; p=0.001). Intravenous-dose clearance, volume of distribution at steady state, plasma half-life, and mean residence time, were similar in the two groups. Less suppression of plasma cortisol concentrations was seen in the asthma group than in controls 4-12 h after inhaled fluticasone propionate. INTERPRETATION: Systemic availability of fluticasone propionate is substantially less in patients with moderate to severe asthma than in healthy controls. Inhaled corticosteroids that are absorbed through the lungs need to be assessed in patients who are receiving doses appropriate for disease severity, and not in normal volunteers.


Assuntos
Androstadienos/administração & dosagem , Antiasmáticos/administração & dosagem , Anti-Inflamatórios/administração & dosagem , Asma/tratamento farmacológico , Administração por Inalação , Administração Tópica , Adulto , Idoso , Androstadienos/farmacocinética , Antiasmáticos/farmacocinética , Anti-Inflamatórios/farmacocinética , Área Sob a Curva , Asma/metabolismo , Asma/fisiopatologia , Disponibilidade Biológica , Estudos Cross-Over , Método Duplo-Cego , Feminino , Fluticasona , Humanos , Hidrocortisona/metabolismo , Masculino , Pessoa de Meia-Idade , Mecânica Respiratória/efeitos dos fármacos
10.
Ann Thorac Surg ; 60(6): 1709-15, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8787468

RESUMO

BACKGROUND: We prospectively investigated the role of sympathetic activation in the etiology of atrial fibrillation following coronary artery bypass grafting. METHODS: Continuous ambulatory monitoring was performed for 80 hours in 131 patients after coronary artery bypass grafting. Right atrial plasma norepinephrine levels were assessed preoperatively and every 4 hours for 48 hours postoperatively. RESULTS: Of the 131 patients, 50% (65) had development of atrial fibrillation and 36% (47) required treatment. Onset of atrial fibrillation was preceded by a significant increase in sinus rate and atrial ectopic activity. On multivariate logistic regression, elevated mean postoperative norepinephrine levels (5.78 +/- 2.83 versus 3.57 +/- 1.31 nmol/L; p < 0.0001), increased age (68.9 +/- 5.7 versus 63.8 +/- 8.7 years; p = 0.02), and decreased postoperative magnesium levels (0.79 +/- 0.09 versus 0.83 +/- 0.10 mmol/L; p = 0.02) were independently associated with the occurrence of atrial fibrillation. CONCLUSIONS: Elevated norepinephrine levels suggest that sympathetic activation may be important in the pathogenesis of atrial fibrillation after coronary artery bypass grafting, and this underlines the importance of beta-adrenoceptor blockade as prophylaxis.


Assuntos
Fibrilação Atrial/etiologia , Ponte de Artéria Coronária/efeitos adversos , Sistema Nervoso Simpático/fisiopatologia , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Eletrocardiografia Ambulatorial , Feminino , Humanos , Magnésio/sangue , Masculino , Norepinefrina/sangue , Estudos Prospectivos
11.
Am J Physiol ; 266(2 Pt 2): H681-92, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8141369

RESUMO

We have applied a mathematical function to model sinus node recovery after atrial pacing at different cycle lengths in 13 autonomically denervated, anesthetized canines. This model provides "pure" indexes of sinoatrial conduction and of suppression of automaticity. We compared sinoatrial conduction computed from the model (SACTc) with sinoatrial conduction measured directly utilizing a catheter recording the sinus node electrogram (SACTd) to test the validity of the model. We used both the model and the sinus node electrogram to further define events after pacing. There was close agreement between SACTc and SACTd with correlation coefficients at pacing cycle lengths of 20 and 50% below resting of 0.86 (P < 0.0001) and 0.78 (P < 0.0001), respectively. We verified that the conventional sinus node recovery time is due both to suppression of automaticity and prolongation of sinoatrial conduction. Sinoatrial conduction time returned rapidly to normal over 1-3 beats, whereas automaticity recovered exponentially over 20-40 postpacing intervals. The model accurately describes postpacing phenomena and has the potential to provide a useful adjunct to the measurement of the sinus node electrogram for assessment of sinus node function in the experimental laboratory.


Assuntos
Sistema de Condução Cardíaco/fisiologia , Modelos Cardiovasculares , Nó Sinoatrial/fisiologia , Animais , Cães , Eletrocardiografia , Frequência Cardíaca , Matemática , Denervação Muscular , Nervo Vago/fisiologia
13.
Southeast Asian J Trop Med Public Health ; 16(3): 395-400, 1985 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-4095603

RESUMO

A study on the adverse reactions, occurring after treating microfilaremic patients infected with B. malayi, revealed that all reacted to a single oral dose of DEC (5 mg/kg). The major reactions were fever, headache, anorexia, abdominal pain, muscle and joint pains, nausea and vomiting. There seemed to be no association between the time of fever onset and microfilarial density, but the number of cases observed was too small to make any firm conclusion. There was a tendency for more severe reactions to occur in patients with higher microfilaria counts. Local reactions, probably due to destruction of adult worms, were seen in 3 patients. The reactions were serious enough to necessitate the patients spending approximately 48 hours in bed.


Assuntos
Dietilcarbamazina/efeitos adversos , Filariose Linfática/tratamento farmacológico , Linfedema/tratamento farmacológico , Adolescente , Adulto , Pressão Sanguínea/efeitos dos fármacos , Brugia , Criança , Dietilcarbamazina/administração & dosagem , Feminino , Febre/induzido quimicamente , Humanos , Indonésia , Masculino , Pessoa de Meia-Idade
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