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1.
Pharm Dev Technol ; 28(3-4): 363-370, 2023.
Article in English | MEDLINE | ID: mdl-36987819

ABSTRACT

Mixing/blending is a crucial operation in the manufacturing of solid drug products in the pharmaceutical industry. Although usually described and controlled in specific steps, blending is also inherent to other operations such as the transference of materials and equipment feeding systems. This study aimed to investigate a simple and fast wettability testing procedure capable to foresee the potential over-blending effects of lubricants occurring during the manufacturing of solid dosage forms. An industrial batch blend was submitted to two mixing mechanisms studies (diffusion and shear) during increasing time periods, and the developed wettability testing procedure was applied to assess their impact on blend water uptake. Capsules filled with these blends were tested for dissolution and disintegration. The method was applied to capsules with known dissolution results manufactured at an industrial scale. Results demonstrated that processes inducing shear stress led to less permeable blends with consequent retardation on capsules dissolution of at least 35% in the tested timepoints and obtained study metrics above 500 s. Moreover, disintegration testing was not able to detect non-compliant dissolutions, while the proposed wettability testing procedure proved to be able to identify performance failures. Wettability results correlate the effect of mixing mechanisms to capsules dissolution performance, evidencing that this technique can be applied in the pharmaceutical industry to evaluate possible over-blending effects.


Subject(s)
Chemistry, Pharmaceutical , Lubricants , Wettability , Chemistry, Pharmaceutical/methods , Solubility , Capsules , Tablets
2.
Nanotechnology ; 30(43): 435502, 2019 Oct 25.
Article in English | MEDLINE | ID: mdl-31323652

ABSTRACT

Here, the ability of using p-type tin oxide (SnO x ) thin films as a thermal sensor has been investigated. Firstly, the thermoelectric performance was optimized by controlling the thickness of the SnO x film from 60 up to 160 nm. A high Seebeck coefficient of +263 µV K-1 and electrical conductivity of 4.1 × 102 (S m-1) were achieved in a 60 nm thick SnO x film, due to a compact nanostructured film and the absence of the Sn metallic phase, which was observed for the thicker SnO x film leading to a typical thermoelectric transport properties of a n-type Sn film. Moreover, x-ray photoelectron spectroscopy revealed the co-existence of SnO (79.7%) and SnO2 (20.3%) phases in the 60 nm thick SnO x film, while the optical measurements revealed an indirect gap of 1.8 eV and a direct gap of 2.7 eV, respectively. The 60 nm-SnO x thin film have been tested as a thermoelectric touch sensor, achieving a Vsignal /Vnoise  ≈ 20, with a rise time <1 s. Therefore, this work provides an efficient way for developing highly efficient thermal sensors with potential use in display technologies.

3.
ACS Appl Mater Interfaces ; 10(17): 15240-15249, 2018 May 02.
Article in English | MEDLINE | ID: mdl-29630331

ABSTRACT

In the present work, we study the hysteretic behavior in the electric-field-dependent capacitance and the current characteristics of 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BCZT)/ZnO bilayers deposited on 0.7 wt % Nb-doped (001)-SrTiO3 (Nb:STO) substrates in a metal-ferroelectric-semiconductor (MFS) configuration. The X-ray diffraction measurements show that the BCZT and ZnO layers are highly oriented along the c-axis and have a single perovskite and wurtzite phases, respectively, whereas high-resolution transmission electron microscopy revealed very sharp Nb:STO/BCZT/ZnO interfaces. The capacitance-electric field ( C- E) characteristics of the bilayers exhibit a memory window of 47 kV/cm and a capacitance decrease of 22%, at a negative bias. The later result is explained by the formation of a depletion region in the ZnO layer. Moreover, an unusual resistive switching (RS) behavior is observed in the BCZT films, where the RS ratio can be 500 times enhanced in the BCZT/ZnO bilayers. The RS enhancement can be understood by the barrier potential profile modulation at the depletion region, in the BCZT/ZnO junction, via ferroelectric polarization switching of the BCZT layer. This work builds a bridge between the hysteretic behavior observed either in the C- E and current-electric field characteristics on a MFS structure.

4.
Nanotechnology ; 28(34): 345701, 2017 Aug 25.
Article in English | MEDLINE | ID: mdl-28628483

ABSTRACT

In this work, we report on the production of regular (SiGe/SiO2)20 multilayer structures by conventional RF-magnetron sputtering, at 350 °C. Transmission electron microscopy, scanning transmission electron microscopy, raman spectroscopy, and x-ray reflectometry measurements revealed that annealing at a temperature of 1000 °C leads to the formation of SiGe nanocrystals between SiO2 thin layers with good multilayer stability. Reducing the nominal SiGe layer thickness (t SiGe) from 3.5-2 nm results in a transition from continuous SiGe crystalline layer (t SiGe ∼ 3.5 nm) to layers consisting of isolated nanocrystals (t SiGe ∼ 2 nm). Namely, in the latter case, the presence of SiGe nanocrystals ∼3-8 nm in size, is observed. Spectroscopic ellipsometry was applied to determine the evolution of the onset in the effective optical absorption, as well as the dielectric function, in SiGe multilayers as a function of the SiGe thickness. A clear blue-shift in the optical absorption is observed for t SiGe ∼ 2 nm multilayer, as a consequence of the presence of isolated nanocrystals. Furthermore, the observed near infrared values of n = 2.8 and k = 1.5 are lower than those of bulk SiGe compounds, suggesting the presence of electronic confinement effects in the nanocrystals. The low temperature (70 K) photoluminescence measurements performed on annealed SiGe/SiO2 nanostructures show an emission band located between 0.7-0.9 eV associated with the development of interface states between the formed nanocrystals and surrounding amorphous matrix.

5.
Sci Rep ; 7: 46350, 2017 04 11.
Article in English | MEDLINE | ID: mdl-28397865

ABSTRACT

An enhanced resistive switching (RS) effect is observed in Pt/BaTiO3(BTO)/ITO ferroelectric structures when a thin HfO2:Al2O3 (HAO) dielectric layer is inserted between Pt and BTO. The P-E hysteresis loops reveal the ferroelectric nature of both Pt/BTO/ITO and Pt/HAO/BTO/ITO structures. The relation between the RS and the polarization reversal is investigated at various temperatures in the Pt/HAO/BTO/ITO structure. It is found that the polarization reversal induces a barrier variation in the Pt/HAO/BTO interface and causes enhanced RS, which is suppressed at Curie temperature (Tc = 140 °C). Furthermore, the Pt/HAO/BTO/ITO structures show promising endurance characteristics, with a RS ratio >103 after 109 switching cycles, that make them potential candidates for resistive switching memory devices. By combining ferroelectric and dielectric layers this work provides an efficient way for developing highly efficient ferroelectric-based RS memory devices.

6.
Rev Port Pneumol (2006) ; 22(6): 315-322, 2016.
Article in English | MEDLINE | ID: mdl-27320704

ABSTRACT

Systemic inflammation has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD) systemic effects. However, most COPD patients do not suffer from persistent systemic inflammation even after exacerbations and exercise and scientific evidence has provided conflicting results. Our aim is to evaluate inflammatory gene expression at rest and at 1 and 24h after strenuous exercise in COPD patients and study the patient variables associated with inflammatory expression. A cross-sectional study was conducted in COPD patients who were recruited on entry to a pulmonary rehabilitation (PR) program. Demographic, clinical and functional data were collected. Blood samples were collected and gene expression was analyzed by reverse transcriptase polymerase chain reaction for IFNg, IL1b, IL6, IL8, TNFa, TGFb1 and iNOS. The study included 21 patients (15 men, 71.4%), mean age 66.1 years old (SD=8.27), mean FEV1 46.76% (SD 20.90%), 67% belonging to GOLD grade D, mean BODE index of 3.9, 90.5% with smoking history, mean BMI 25.81 (SD=4.87), median of 1.29 exacerbations in the previous year. There was no statistical significant difference between inflammatory expression at rest and at 1h and 24h after the maximal exercise test for all tested genes. We found an association between BMI and inflammatory expression at all the points of time checked, a slight inverse association occurs with low BMI for mRNA IL1b, IL6, TNFa, TGFb1 and iNOS, and there was a more pronounced positive association for obese patients for all tested genes. This preliminary study did not show an enhanced inflammatory gene expression from rest to 1h and 24h after short-term exercise, but did show an increased inflammatory gene expression in both BMI extremes, both at rest and after exercise, suggesting not only malnourishment, but also obesity as potential links between COPD and systemic inflammation. Studies with larger samples and designed to definitely exclude OSA or OHS as confounding factors in obese patients are required.


Subject(s)
Exercise , Inflammation/etiology , Obesity/complications , Pulmonary Disease, Chronic Obstructive/complications , Aged , Aged, 80 and over , Cross-Sectional Studies , Female , Humans , Inflammation/genetics , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/genetics
7.
Nanoscale ; 8(20): 10706-13, 2016 May 19.
Article in English | MEDLINE | ID: mdl-27150301

ABSTRACT

Oral delivery of proteins is still a challenge in the pharmaceutical field. Nanoparticles are among the most promising carrier systems for the oral delivery of proteins by increasing their oral bioavailability. However, most of the existent data regarding nanosystems for oral protein delivery is from in vitro studies, lacking in vivo experiments to evaluate the efficacy of these systems. Herein, a multifunctional composite system, tailored by droplet microfluidics, was used for dual delivery of glucagon like peptide-1 (GLP-1) and dipeptidyl peptidase-4 inhibitor (iDPP4) in vivo. Oral delivery of GLP-1 with nano- or micro-systems has been studied before, but the simultaneous nanodelivery of GLP-1 with iDPP4 is a novel strategy presented here. The type 2 diabetes mellitus (T2DM) rat model, induced through the combined administration of streptozotocin and nicotinamide, a non-obese model of T2DM, was used. The combination of both drugs resulted in an increase in the hypoglycemic effects in a sustained, but prolonged manner, where the iDPP4 improved the therapeutic efficacy of GLP-1. Four hours after the oral administration of the system, blood glucose levels were decreased by 44%, and were constant for another 4 h, representing half of the glucose area under the curve when compared to the control. An enhancement of the plasmatic insulin levels was also observed 6 h after the oral administration of the dual-drug composite system and, although no statistically significant differences existed, the amount of pancreatic insulin was also higher. These are promising results for the oral delivery of GLP-1 to be pursued further in a chronic diabetic model study.


Subject(s)
Diabetes Mellitus, Type 2/drug therapy , Dipeptidyl-Peptidase IV Inhibitors/administration & dosage , Enzyme Inhibitors/administration & dosage , Glucagon-Like Peptide 1/antagonists & inhibitors , Hypoglycemic Agents/administration & dosage , Microfluidics , Animals , Blood Glucose , Diabetes Mellitus, Experimental/drug therapy , Insulin , Male , Rats , Rats, Wistar
9.
Nanotechnology ; 23(40): 405605, 2012 Oct 12.
Article in English | MEDLINE | ID: mdl-22997179

ABSTRACT

In this work, the influence of air pressure during the annealing of Ge quantum dot (QD) lattices embedded in an amorphous Al(2)O(3) matrix on the structural, morphological and compositional properties of the film is studied. The formation of a regularly ordered void lattice after performing a thermal annealing process is explored. Our results show that both the Ge desorption from the film and the regular ordering of the QDs are very sensitive to the annealing parameters. The conditions for the formation of a void lattice, a crystalline Ge QD lattice and a disordered QD lattice are presented. The observed effects are explained in terms of oxygen interaction with the Ge present in the film.

10.
Case Rep Urol ; 2012: 849681, 2012.
Article in English | MEDLINE | ID: mdl-22919536

ABSTRACT

The nutcracker syndrome (NCS) is a rare cause of haematuria. It embraces an extended nonpathognomonic spectrum of symptoms that imply a difficult diagnosis. Ultimately it may be associated with substantial morbidity and even life-threatening events. We report a rare cause if a 12-year-old boy who presented with a history of frequent intermittent episodes of painless constant haematuria. The cystoscopy showed a bloody urine ejaculate from the left ureter meatus. The Doppler ultrasonography showed turbulent pattern of venous blood flow of the posterior renal vein branch behind the aorta. The abdominopelvic computer tomography (apCT) revealed left renal vein (LRV) duplication with a dilated retroaortic branch, entrapped between the aorta and the vertebral column, promoting the renal nutcracker syndrome. The patient was initially hospitalized and managed with oral iron supplements and continuous saline bladder irrigation, not requiring additional treatment. The child is currently asymptomatic, with haemoglobin value returning to normal and therefore proposed to conservative management with close followup. The authors present a case report of episodic haematuria caused by a rare entity-posterior nutcracker syndrome with renal vein duplication.

11.
Nanotechnology ; 21(50): 505705, 2010 Dec 17.
Article in English | MEDLINE | ID: mdl-21098929

ABSTRACT

We report on the structural and electrical properties of Mn-doped ZnO/Al(2)O(3) nanostructures produced by the pulsed laser deposition technique. Grazing incidence small angle x-ray scattering (GISAXS) and Rutherford backscattering spectrometry revealed the multilayered structure in as-deposited samples. Annealing of the nanostructures was shown to promote the formation of nanocrystals embedded in the Al(2)O(3) matrix, as was evidenced by GISAXS and high resolution transmission microscopy. Particle-induced x-ray emission analysis showed a doping of 8 at.% Mn in ZnO. Grazing incidence x-ray diffraction and Raman spectroscopy demonstrated that the nanocrystals have the pure wurtzite ZnMnO crystalline phase. Resonant Raman scattering displayed an increase of intensity of the 1LO mode as well as broadening of the 2LO mode related to the size effect. Capacitance-voltage measurements showed carrier retention with a voltage shift higher than those reported for similar systems.

12.
Rev Port Pneumol ; 16(6): 899-906, 2010.
Article in English, Portuguese | MEDLINE | ID: mdl-21067696

ABSTRACT

The Portuguese Journal of Pulmonology is progressively achieving an important status in Portuguese medical literature. The present editors thought it would be an enriching task to revise the main topics published during 2009. The invited members of the Editorial Board covered and commented the most relevant articles and gave us an important picture of the quality of the science it was published in Portuguese Pulmonology.


Subject(s)
Periodicals as Topic , Pulmonary Medicine , Humans , Portugal
13.
J Nanosci Nanotechnol ; 10(4): 2858-62, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20355514

ABSTRACT

Alumina films containing gold nanoparticles (NPs) were grown by magnetron radio frequency (rf) sputtering technique. They were investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD) and optical absorption spectroscopy. It is suggested that the increase of the contrast of surface plasmon resonance band after annealing is connected with increasing of electron free mean path in Au NPs rather than with change in particle size distribution. The absorption spectra of the nanocomposites have been modelled taking into account a correction of the dielectric constant for electron mean free path limitation.

14.
Clin Rev Allergy Immunol ; 38(2-3): 307-18, 2010 Apr.
Article in English | MEDLINE | ID: mdl-19557315

ABSTRACT

Systemic lupus erythematosus (SLE) is a disease of unknown cause that may involve one or many organ or systems. Skin involvement is a major feature in this disease, and a wide variety of skin conditions may be present. Lupus erythematosus panniculitis (LEP) constitutes a rare form of cutaneous lupus characterized by recurrent nodular or plaque lesions that can vary from a benign and mild course to a more disfiguring disease. Initial therapy includes corticosteroids, antimalarials, and azathioprine and, in refractory cases, two antimalarials in association, mycophenolate mofetil, or other immunomodulators. Intravenous immuglobulin (IVIG) is used in many autoimmune disorders, like in SLE, although clinical trials have not yet taken place. In this report, we review skin manifestations of SLE and their treatment, IVIG, and finally a case of LEP successfully treated with IVIG when other therapy modalities failed.


Subject(s)
Immunoglobulins, Intravenous/therapeutic use , Panniculitis, Lupus Erythematosus/drug therapy , Adult , Female , Humans , Immunosuppressive Agents/therapeutic use , Middle Aged , Panniculitis, Lupus Erythematosus/physiopathology
15.
J Nanosci Nanotechnol ; 9(6): 3418-23, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19504863

ABSTRACT

In this paper we report on the structural, optical and electrical properties of CdSe nanocrystals (NCs) embedded in silica matrix grown by the rf-magnetron sputtering technique with subsequent annealing under argon flux. Grazing incidence X-ray diffraction (GIXD), Photoluminescence (PL) and Raman spectroscopy, as well as current-voltage (I-V) measurements were used to characterize the CdSe NCs. The PL spectra of annealed samples demonstrate the presence of peaks in the range of 550-620 nm, indicating the quantum confinement effect in CdSe NCs. This quantum confinement effect in CdSe NCs was also confirmed by Raman spectroscopy. Finally, I-V behavior was explained by different concentrations and sizes of CdSe NCs.

16.
J Nanosci Nanotechnol ; 9(6): 3555-61, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19504881

ABSTRACT

This paper reports on the systematic optical characterization of Er3+ (1.0%) doped lead-zinc-borate glass from the measured absorption, luminescence and fluorescence lifetime decay curve profiles. By the application of the Judd-Ofelt theory, spectral intensities of the absorption bands have been analysed and these absorption results have been used in evaluating the luminescence properties of the Er3+ doped lead-zinc-borate glass. Stimulated emission cross-sections (sigmapE) of the measured emission transitions have been computed. Based on the measured glass density, and refractive indices, other related physical parameters have also been evaluated. Further, the structural and morphology of the glass material have also been investigated from X-ray diffraction, Fourier transform infrared spectroscopy, and scanning electron microscopy analysis.

17.
J Nanosci Nanotechnol ; 9(6): 3672-7, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19504901

ABSTRACT

This paper reports on the development and spectral analysis of Sm3+ (1.0%) and Dy3+ (1.0%) doped lithium-boro-tellurite glasses. A bright orange (4G5/2-->6H7/2) along with a red (4G5/2-->6H9/2) and a yellow (4G5/2-->6H5/2) emission transition have been measured from Sm3+ doped lithium-boro-tellurite glass. Both blue (4F9/2-->6H15/2) and yellow (4F9/2-->6H13/2) emission bands have been obtained from Dy3+ glass. From the measured decay profiles, the lifetimes of the emissions of the Sm3+ glass (4G5/2-->6H5/2, 7/2, 9/2 and 11/2) at an excitation of 401 nm have been found to be in the range 0.47-0.81 ms, and with respect to the Dy3+ emissions (4F9/2-->6H15/2 and 13/2), with excitation at 450 nm, are measured to be in the range of 0.302-0.307 ms. Stimulated emission cross-sections (sigmapE) of the measured emission transitions have also been computed and the values are in the range of (0.38-1.20) x 10(-20) cm2 for Sm3+ and for Dy3+ doped lithium-boro-tellurite glass the values are (0.66-1.39) x 10(-20) cm2.

18.
J Nanosci Nanotechnol ; 8(2): 572-6, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18464372

ABSTRACT

Ge nanocrystals (NCs) embedded in aluminum oxide were grown by RF-magnetron sputtering. Raman, high resolution transmission electron microscopy (HRTEM), selected area diffraction (SAD), and X-ray diffraction (XRD) techniques confirmed good cristallinity of the NCs from samples annealed at 800 degrees C. The average NC size was estimated to be around 7 nm. Photoluminescence (PL) measurements show an emission related to the NCs. The temperature dependence of the PL confirms the confinement phenomenon in the Ge NCs.

19.
J Anim Sci ; 83(2): 350-7, 2005 Feb.
Article in English | MEDLINE | ID: mdl-15644507

ABSTRACT

The relationship between ultrasound measurements and empty body and carcass chemical composition was investigated. A 500-V real-time ultrasound with a 7.5-MHz probe combined with image analysis was used to make in vivo measurements to predict the empty body and carcass chemical composition of 31 female lambs of two genotypes, ranging in BW from 18.2 to 48.9 kg. Eleven ultrasound measurements of s.c. fat, muscle, and tissue depth were taken at four different sites (over the 13th thoracic vertebra, between the 3rd and 4th lumbar vertebrae, at the 3rd sternebra of the sternum, and over the 11th rib, 16 cm from the dorsal midline). The single best predictor of empty body fat quantity and energy value was the s.c. fat depth over the 13th thoracic vertebra (r(2) = 0.904 and 0.912; P <0.01, respectively). Body weight was used with ultrasound measurements in multiple regression equations to establish the best independent variables combination for predicting chemical composition. Results showed that BW and two of the three ultrasound measurements (s.c. fat depth over the 13th thoracic vertebra, between the 3rd and 4th lumbar vertebrae, and tissue depth over the 11th rib, 16 cm from the dorsal midline), explained 94.7 to 98.7% (P < 0.01) of the quantity of water and fat and the energy value variation in the empty body and carcass. Body weight per se was the best predictor of the quantity of protein, accounting for 97.5 and 96.8% (P < 0.01) of the variation observed in the empty body and carcass, respectively. The results of this study suggest that BW and some ultrasound measurements combined with image analysis, particularly subcutaneous fat depth over the 13th thoracic vertebra, allow accurate prediction of empty body and carcass chemical composition in lambs.


Subject(s)
Adipose Tissue/diagnostic imaging , Animal Husbandry/methods , Body Composition/physiology , Diet/veterinary , Sheep/physiology , Adipose Tissue/physiology , Animal Feed/analysis , Animals , Dietary Proteins/analysis , Female , Image Processing, Computer-Assisted , Proteins/analysis , Proteins/physiology , Regression Analysis , Sheep/growth & development , Ultrasonography , Water/analysis , Water/physiology
20.
Acta Med Port ; 14(3): 317-21, 2001.
Article in Portuguese | MEDLINE | ID: mdl-11556358

ABSTRACT

UNLABELLED: When, at the end of a medical visit, a doctor prescribes medication, he may be unaware that writing is unknown to the patient. This fact compromises the patient's understanding of disease and therapeutics and thus the importance of diagnosing illiteracy. The A.A studied prospectively 200 consecutive patients admitted to a Medical Ward at Santa Maria Hospital in Lisbon, from 13/3/1997 to 8/7/1998. The study included age, gender, social environment, evaluation of the ability to read and write, years of scholarship and the principal diagnosis. The results were to chi 2 (Yates) and Student's T-tests. RESULTS: 94 patients were male and 106 female, aged between 18 and 95 years (mean 62.3), 106 from an urban environment, 54 from a rural environment and 37 had lived their adult life in a rural environment but were at present living in an urban environment. The percentage of illiteracy was 30.5%, being considerably higher in the females (43.4%) than in the males (15.96%), in patients above 65 years (49%) compared to patients from 15 to 64 years old (12%), in non-urban patients (55%) opposed to urban born patients (10.4%). Any of these variables, gender, age and social environments had statistical significance to P < 0.001 when associated to illiteracy. CONCLUSIONS: The comparative analysis of the official results for the general Portuguese Population study, Census 91, shows an important analogy. In both studies illiteracy was worst in females and in those above 65 years of age. Today illiteracy is still days a serious National problem, with important medical implications, a troublesome obstacle to the understanding of the disease and compliance with therapy.


Subject(s)
Educational Status , Adolescent , Adult , Aged , Aged, 80 and over , Female , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Prospective Studies
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