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1.
Nanomaterials (Basel) ; 13(17)2023 Aug 24.
Article in English | MEDLINE | ID: mdl-37686915

ABSTRACT

OEMT is an existing optimizing envelope method for thin-film characterization that uses only one transmittance spectrum, T(λ), of the film deposited on the substrate. OEMT computes the optimized values of the average thickness, d¯, and the thickness non-uniformity, Δd, employing variables for the external smoothing of T(λ), the slit width correction, and the optimized wavelength intervals for the computation of d¯ and Δd, and taking into account both the finite size and absorption of the substrate. Our group had achieved record low relative errors, <0.1%, in d¯ of thin semiconductor films via OEMT, whereas the high accuracy of d¯ and Δd allow for the accurate computation of the complex refractive index, N˙(λ), of the film. In this paper is a proposed envelope method, named OEMR, for the characterization of thin dielectric or semiconductor films using only one quasi-normal incidence UV/Vis/NIR reflectance spectrum, R(λ), of the film on the substrate. The features of OEMR are similar to the described above features of OEMT. OEMR and several popular dispersion models are employed for the characterization of two a-Si films, only from R(λ), with computed d¯ = 674.3 nm and Δd = 11.5 nm for the thinner film. It is demonstrated that the most accurate characterizations of these films over the measured spectrum are based on OEMR.

2.
Materials (Basel) ; 15(23)2022 Dec 02.
Article in English | MEDLINE | ID: mdl-36500112

ABSTRACT

Notwithstanding the significant optical applicability of PAZO polymer films, there are no accurate data about their optical characteristics. To remedy this shortcoming, in this study three PAZO polymer thin films are characterized, with dissimilar thicknesses, on glass substrates using only one UV/VIS/NIR transmittance spectrum T(λ) per sample and an original hybrid dispersion model (HDM). HDM is based on the Tauc-Lorentz model, the new amorphous dispersion formula, the Tauc-Lorentz-Urbach model of Foldyna and the Tauc-Lorentz-Urbach model of Rodriguez. HDM with two oscillators is employed in characterizations of the PAZO polymer films in the range [300, 2500] nm, whereby the root-mean-square deviation (RMSD) of the fitted transmittance spectrum with respect to T(λ) does not exceed 1.6 × 10-3. Decreasing RMSD by 2.3% to 94.4% is demonstrated by employing HDM compared with the above mentioned four popular dispersion models, for each one of the studied films. HDM is applicable to amorphous films independent of their thickness as well as to cases of non-transparent substrate.

3.
Materials (Basel) ; 14(16)2021 Aug 19.
Article in English | MEDLINE | ID: mdl-34443203

ABSTRACT

Three means are investigated for further increasing the accuracy of the characterization of a thin film on a substrate, from the transmittance spectrum T(λ) of the specimen, based on the envelope method. Firstly, it is demonstrated that the accuracy of characterization, of the average film thickness d¯ and the thickness non-uniformity ∆d over the illuminated area, increases, employing a simple dual transformation utilizing the product T(λ)xs(λ), where Tsm(λ) is the smoothed spectrum of T(λ) and xs(λ) is the substrate absorbance. Secondly, an approach is proposed for selecting an interval of wavelengths, so that using envelope points only from this interval provides the most accurate characterization of d¯ and ∆d, as this approach is applicable no matter whether the substrate is transparent or non-transparent. Thirdly, the refractive index n(λ) and the extinction coefficient k(λ) are computed, employing curve fitting by polynomials of the optimized degree of 1/λ, instead of by previously used either polynomial of the optimized degree of λ or a two-term exponential of λ. An algorithm is developed, applying these three means, and implemented, to characterize a-Si and As98Te2 thin films. Record high accuracy within 0.1% is achieved in the computation of d¯ and n(λ) of these films.

4.
Circulation ; 122(12): 1183-91, 2010 Sep 21.
Article in English | MEDLINE | ID: mdl-20823391

ABSTRACT

BACKGROUND: Medication nonadherence is common and results in preventable disease complications. This study assessed the effectiveness of a multifactorial intervention to improve both medication adherence and blood pressure control and to reduce cardiovascular events. METHODS AND RESULTS: In this multicenter, cluster-randomized trial, physicians from hospital-based hypertension clinics and primary care centers across Spain were randomized to receive and provide the intervention to their high-risk patients. Eligible patients were ≥ 50 years of age, had uncontrolled hypertension, and had an estimated 10-year cardiovascular risk greater than 30%. Physicians randomized to the intervention group counted patients' pills, designated a family member to support adherence behavior, and provided educational information to patients. The primary outcome was blood pressure control at 6 months. Secondary outcomes included both medication adherence and a composite end point of all-cause mortality and cardiovascular-related hospitalizations. Seventy-nine physicians and 877 patients participated in the trial. The mean duration of follow-up was 39 months. Intervention patients were less likely to have an uncontrolled systolic blood pressure (odds ratio 0.62, 95% confidence interval 0.50 to 0.78) and were more likely to be adherent (odds ratio 1.91, 95% confidence interval 1.19 to 3.05) than control group patients at 6 months. After 5 years, 16% of the patients in the intervention group and 19% in the control group met the composite end point (hazard ratio 0.97, 95% confidence interval 0.67 to 1.39). CONCLUSIONS: A multifactorial intervention to improve adherence to antihypertensive medication was effective in improving both adherence and blood pressure control, but it did not appear to improve long-term cardiovascular events.


Subject(s)
Antihypertensive Agents/therapeutic use , Blood Pressure/physiology , Cardiovascular Diseases/epidemiology , Hypertension/drug therapy , Patient Compliance , Adult , Female , Follow-Up Studies , Humans , Hypertension/physiopathology , Kaplan-Meier Estimate , Longitudinal Studies , Male , Middle Aged , Outcome Assessment, Health Care , Patient Education as Topic , Risk Factors , Spain , Treatment Outcome
7.
Clin Drug Investig ; 27(11): 765-70, 2007.
Article in English | MEDLINE | ID: mdl-17914895

ABSTRACT

OBJECTIVE: To assess the acceptability of lansoprazole orally disintegrating tablets (LODT) in patients with gastro-oesophageal reflux disease (GORD). METHODS: A multicentre, observational, cross-sectional study of patients diagnosed with GORD aged > or =18 years under the care of 272 gastroenterologists. Acceptability was determined by global patient assessment whereby the drug's organoleptic characteristics and properties were evaluated by a self-administered 11-item ad hoc questionnaire with a 5-point Likert-type scale. RESULTS: A total of 734 patients (mean age 49.6 years [SD = 15.2]) with GORD who had been prescribed LODT > or =14 days prior to inclusion in the study were evaluable for the main endpoint. Of these, 51.1% were men. Most patients (80.7%) had been treated with doses of LODT 30mg/day for an average of 52.7 days (SD = 59.3). Overall, 93.6% of patients rated LODT treatment as 'very acceptable' or ''acceptable'. The degree of acceptability was associated with the perception that the formulation helps treatment compliance (p < 0.001). The drug's properties were rated as follows: size 'neither large nor small' (70.0%); flavour 'very pleasant' or 'pleasant' (75.2%); intensity of flavour 'neither strong nor mild', 'mild' or 'very mild' (86.1%); no 'sandy sensation' (53.4%); speed of dissolving 'fast' or 'very fast' (80.2%); use of tablets 'very easy' or 'easy' (92.4%) and use of tablets 'very convenient' or 'convenient' (91.0%). Three adverse reactions, none of them serious, were reported in three patients (0.4%). CONCLUSIONS: LODT were well accepted by patients with GORD. Patients reported that this formulation improved compliance with therapy. Tolerability was excellent.


Subject(s)
2-Pyridinylmethylsulfinylbenzimidazoles/administration & dosage , Gastroesophageal Reflux/drug therapy , Patient Acceptance of Health Care , Proton Pump Inhibitors/administration & dosage , Administration, Oral , Adolescent , Adult , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Lansoprazole , Male , Middle Aged , Patient Compliance , Tablets
8.
Clin Drug Investig ; 27(6): 407-17, 2007.
Article in English | MEDLINE | ID: mdl-17506591

ABSTRACT

BACKGROUND: Twenty-four-hour ambulatory blood pressure monitoring (ABPM) provides the most accurate efficacy assessment of an antihypertensive agent throughout a 24-hour dosing interval. The objective of this prospective, randomised, double-blind, parallel-group, multicentre study was to compare the antihypertensive efficacy of imidapril versus candesartan cilexetil using ABPM. METHODS: After screening and a single-blind, placebo run-in phase, ambulatory adult patients with mild to moderate hypertension (defined as a mean office sitting diastolic BP [DBP] and systolic BP [SBP], respectively, of 90-109 mm Hg and 140-179 mm Hg, and a mean ABPM DBP and SBP, respectively, of >or=80 mm Hg and >or=125 mm Hg) were randomised to once-daily treatment with imidapril or candesartan cilexetil for 12 weeks. ABPM was performed at baseline and at the end of the 12-week treatment period in 112 patients (imidapril group, n=55; candesartan cilexetil group, n=57). To achieve the target BP of

Subject(s)
Angiotensin II Type 1 Receptor Blockers/therapeutic use , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Benzimidazoles/therapeutic use , Biphenyl Compounds/therapeutic use , Hypertension/drug therapy , Imidazolidines/therapeutic use , Tetrazoles/therapeutic use , Adult , Aged , Angiotensin II Type 1 Receptor Blockers/adverse effects , Angiotensin-Converting Enzyme Inhibitors/adverse effects , Benzimidazoles/adverse effects , Biphenyl Compounds/adverse effects , Blood Pressure/drug effects , Blood Pressure Monitoring, Ambulatory , Double-Blind Method , Humans , Imidazolidines/adverse effects , Middle Aged , Prospective Studies , Tetrazoles/adverse effects
9.
Appl Opt ; 41(34): 7300-8, 2002 Dec 01.
Article in English | MEDLINE | ID: mdl-12477122

ABSTRACT

The role played by a glass substrate on the accurate determination of the optical constants and the thickness of a thin dielectric film deposited on it, when well-known envelope methods are used, is discussed. Analytical expressions for the two envelopes of the optical transmission spectra corresponding to film. with both uniform and nonuniform thicknesses are derived, assuming the substrate to be a weakly absorbing layer. It is shown that accurate determination of the refractive index and the film thickness is notably improved when the absorption of the substrate is considered. The analytical expressions for the upper and lower envelope, are used to characterize optically and geometrically both uniform and nonuniform amorphous chalcogenide films. The results obtained are compared with those derived by use of expressions for the envelopes that neglect the substrate absorption. The comparison shows that overestimated refractive indexes and underestimated thicknesses are obtained when the conventional approach, in which the substrate absorption is neglected, is used.

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