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1.
Nutr. hosp ; 39(3): 547-553, may. - jun. 2022. tab
Artigo em Espanhol | IBECS | ID: ibc-209935

RESUMO

Aim: type-2 diabetes (T2DM) seems to worsen the prognosis of patients admitted for COVID-19, although most studies included Asiatic patients. We aimed to assess whether this condition applies for Mediterranean patients. Methods: a total of 90 patients admitted for COVID-19 with T2DM were retrospectively compared with 50 patients without T2DM. Results: subjects with T2DM were older than their counterparts (73.3 ± 12.4 vs 53 ± 15.7 years; p < 0.0001). Either absolute lymphocyte count (1.1 ± 0.6 vs 1.3 ± 0.7 x 109/L; p = 0.005) or hemoglobin (11.9 ± 1.6 vs 13.1 ± 2.1 g/dL; p < 0.0001) were lower among subjects with T2DM. CRP and procalcitonin were higher among subjects with T2DM (91.9 ± 71.2 vs 70.1 ± 63.3 mg/L; p = 0.002 and 0.8 ± 0.3 vs 0.4 ± 0.1 ng/mL; p < 0.0001, respectively). Albumin was lower among patients with T2DM (3.4 ± 0.5 vs 3.8 ± 0.5 g/L: p < 0.001). Length of stay was longer among subjects with T2DM (11.7 ± 7.7 vs 9.7 ± 8.6 days; p = 0.01). However, both groups were comparable regarding both the proportion of subjects who were admitted to the ICU (16.5 % vs 8 %; p = 0.1) and mortality (11 % vs 4 %; p = 0.2). Conclusions: in a Mediterranean sample, despite of age, comorbidities, nutritional status, and inflammatory markers, subjects with T2DM with a proper glycemic control admitted for COVID-19 had similar prognostic outcomes than patients without this metabolic condition (AU)


Objetivo: la diabetes de tipo 2 (DM2) parece empeorar el pronóstico de los pacientes ingresados por COVID-19, aunque la mayoría de los estudios incluyeron pacientes asiáticos. Nuestro objetivo fue evaluar si esto se aplica a los pacientes de una población Mediterránea. Métodos: un total de 90 pacientes ingresados por COVID-19 con DM2 se compararon retrospectivamente con 50 pacientes sin DM2. Resultados: los sujetos con DM2 eran mayores que sus contrapartes (73,3 ± 12,4 frente a 53 ± 15,7 años; p < 0,0001). El recuento absoluto de linfocitos (1,1 ± 0,6 vs. 1,3 ± 0,7 x 109/L; p = 0,005) o la hemoglobina (11,9 ± 1,6 vs. 13,1 ± 2,1 g/dL; p < 0,0001) fueron menores entre los sujetos con DM2. La PCR y la procalcitonina fueron mayores entre los sujetos con DM2 (91,9 ± 71,2 frente a 70,1 ± 63,3 mg/L; p = 0,002 y 0,8 ± 0,3 frente a 0,4 ± 0,1 ng/ml; p < 0,0001, respectivamente). La albúmina fue menor entre los pacientes con DM2 (3,4 ± 0,5 vs. 3,8 ± 0,5 g/L: p < 0,001). La estancia hospitalaria fue mayor entre los sujetos con DM2 (11,7 ± 7,7 frente a 9,7 ± 8,6 días; p = 0,01). Sin embargo, ambos grupos fueron comparables en cuanto a la proporción de sujetos con ingreso en la UCI (16,5 % vs. 8 %; p = 0,1) y la mortalidad (11 % vs. 4 %; p = 0,2). Conclusiones: en una muestra mediterránea, a pesar de la edad, las comorbilidades, el estado nutricional y los marcadores inflamatorios, los sujetos con DM2 con un adecuado control glucémico ingresados por COVID-19 tuvieron resultados pronósticos similares a los de los pacientes sin esta condición metabólica (AU)


Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Diabetes Mellitus , Infecções por Coronavirus/mortalidade , Pneumonia Viral/mortalidade , Pandemias , Comorbidade , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Estudos de Casos e Controles
2.
Opt Lett ; 47(10): 2498-2501, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35561384

RESUMO

Integrated silicon nitride waveguides of 100 nm height can achieve ultralow propagation losses below 0.1 dB/cm at the 1550 nm wavelength band but lack the scattering strength to form efficient grating couplers. An enhanced grating coupler design based on an amorphous silicon layer on top of silicon nitride is proposed and demonstrated to improve the directionality of the coupler. The fabrication process is optimized for a self-alignment process between the amorphous silicon and silicon nitride layers without increasing waveguide losses. Experimental coupling losses of 5 dB and a 3 dB bandwidth of 75 nm are achieved with both regular and focusing designs.

3.
J Endocrinol Invest ; 45(4): 875-882, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34792795

RESUMO

BACKGROUND: As COVID-19 became a pandemic, the urgent need to find an effective treatment vaccine has been a major objective. Vaccines contain adjuvants which are not exempt from adverse effects and can trigger the autoimmune/inflammatory syndrome induced by adjuvants (ASIA). There is very little information about autoimmune endocrine disease and the ASIA after the use of mRNA-based SARS-CoV2 vaccination. CASE SERIES: We report three cases and also review the literature showing that the thyroid gland can be involved in the ASIA induced by the mRNA-based SARS-CoV2 vaccination. We present the first case to date of silent thyroiditis described in the context of SARS-CoV2 vaccination with Pfizer/BioNTech. Also, we discuss the first subacute thyroiditis in the context of SARS-CoV2 vaccination with the Moderna's vaccine. Finally, we provide another case to be added to existing evidence on Graves' disease occurring post-vaccination with the Pfizer/BioNTech vaccine. DISCUSSION: Adjuvants play an important role in vaccines. Their ability to increase the immunogenicity of the active ingredient is necessary to achieve the desired immune response. Both the Moderna and the Pfizer/BioNTech vaccines use mRNA coding for the SARS-CoV2 S protein enhanced by adjuvants. In addition, the cross-reactivity between SARS-CoV2 and thyroid antigens has been reported. This would explain, at least, some of the autoimmune/inflammatory reactions produced during and after SARS-CoV2 infection and vaccination. CONCLUSION: The autoimmune/inflammatory syndrome induced by adjuvants involving the thyroid could be an adverse effect of SARS-CoV2 vaccination and could be underdiagnosed.


Assuntos
Vacinas contra COVID-19/efeitos adversos , Doença de Graves/etiologia , Glândula Tireoide/imunologia , Tireoidite/etiologia , Vacinação/efeitos adversos , Adulto , Vacinas contra COVID-19/imunologia , Feminino , Doença de Graves/imunologia , Humanos , Masculino , Tireoidite/imunologia
4.
BMC Psychol ; 7(1): 14, 2019 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-30841895

RESUMO

BACKGROUND: Diverse studies have investigated the relationship between diet and depression. In fact some cross-sectional studies suggested that a healthy diet reduced the risk for depression. The main objective of this study was to assess the relationship of consumption of different food groups with depression. The food groups were selected based on their content of substances that were precursors to neurotransmitters (tryptophan or inositol) or their effect on oxidative stress. METHODS: This observational retrospective study compared the diets of individuals who were with depressive symptoms (Beck Depression Inventory Questionnaire [BDI] ≥ 10; 53 women, 23 men, age 38+/- 11) and with no depressive levels (BDI < 10; 33 women, 23 men, age 41+/- 13). Dietary data were collected from a questionnaire that asked about consumption of legumes, nuts, whole-grain foods, fruits and vegetables, chocolate, and sweet foods and refined sugars. RESULTS: Depressed individuals consumed significantly lower amounts of legumes, fruits, and vegetables, but higher amounts of sweets and refined sugars (p < 0.05 for all comparisons). After statistical adjustment for age and sex, the consumption of no legumes (adjusted odds ratio [aOR] = 2.60, 95% confidence interval [CI] = 1.19-5.67), low consumption of fruits and vegetables (aOR = 2.69, 95% CI = 1.18-6.13), and high consumption of sweet foods and refined sugars (aOR = 1.91, 95% CI = 1.23-2.99) were significantly associated with depression. The two groups had no significant differences in the consumption of chocolate. DISCUSSION: The results indicate significant relationships of the consumption of certain foods with depression, although the study design precludes any conclusions regarding causality. Further studies are necessary to determine the causal relationships of the consumption of specific foods with depression, and of depression with the consumption of specific foods. CONCLUSION: In spite of the limitations, we find that individuals without depression consumed more legumes, fruits, and vegetables, but fewer sweets and pastries than those with depression.


Assuntos
Depressão/etiologia , Dieta/psicologia , Adulto , Estudos Transversais , Feminino , Frutas , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Inquéritos e Questionários , Verduras
5.
J Endocrinol Invest ; 42(8): 881-888, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30788770

RESUMO

BACKGROUND: Depressive disorder encompasses a wide spectrum of somatic and psychological symptoms. It is not known whether there are differences regarding the cluster of depressive symptomatology between subjects with depression with and without T2DM. PURPOSE: To explore whether the cluster of depression that prevails among depressive subjects with T2DM differs from individuals with depression, but without T2DM. METHODS: 87 T2DM patients with a pathological Beck Depression Inventory test (BDI) were compared with 50 age- and gender-matched individuals with a major depressive disorder. All 21 items expressed in the BDI were compared between the two groups. RESULTS: The score obtained after administering the BDI was comparable between patients with T2DM and significant depressive symptoms and the control group (18.8 ± 2.7 vs 18.9 ± 3.4; p = 0.9). Subjects with T2DM had higher scores compared with the control group in the following items: sadness (1.4 ± 0.9 vs 0.9 ± 0.9; p = 0.011), difficulty in concentration (1.3 ± 0.8 vs 0.8 ± 0.8; p = 0.01), indecisiveness (1.1 ± 0.8 vs 0.5 ± 0.9; p = 0.012), worries about their health (1.3 ± 0.9 vs 0.6 ± 0.9; p < 0.0001), fatigue (1.2 ± 0.6 vs 0.8 ± 0.7; p = 0.003) and loss of sexual appetite (2.7 ± 0.6 vs 1.2 ± 1.3; p = 0.0001). Suicidal ideation was significantly lower among subjects with T2DM compared with the control group (0.1 ± 0.3 vs 0.6 ± 0.8; p = 0.0001). CONCLUSIONS: Subjects with T2DM and a positive screening for depression presented a different cluster of depression compared with depressed subjects without T2DM, with a predominance of somatic-biological depressive symptoms rather than psychological-cognitive cluster and negative emotions, such as suicidal ideation.


Assuntos
Sintomas Afetivos/etiologia , Depressão/classificação , Transtorno Depressivo Maior/etiologia , Diabetes Mellitus Tipo 2/complicações , Adulto , Estudos de Casos e Controles , Depressão/etiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico
6.
Opt Lett ; 42(3): 490-493, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28146509

RESUMO

In this Letter, we present the design, simulation (2D and 3D), fabrication, and experimental characterization of compact and fully etched focusing gratings for a horizontal slot waveguide based on a silicon nitride layer sandwiched between amorphous silicon and a silicon-on-insulator. The measured coupling losses are about 4 dB with a 3 dB bandwidth of 38 nm. The fully etched configuration allows the fabrication in a single lithography step.

7.
Exp Clin Endocrinol Diabetes ; 124(10): 630-636, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27437917

RESUMO

Objective: To determine the frequency and clinical parameters, of clinically significant depressive symptoms among a type 2 diabetes (T2DM) sample from a Mediterranean area without an established diagnosis of depressive disorder (DD). Methods: 320 subjects with T2DM were recruited randomly from Primary-Care settings and the Endocrine Department from a tertiary center in Mallorca (Spain). 91 healthy individuals matched by age, gender and BMI were used as controls. All participating patients graded by the presence of DD by using the "Beck Depression Inventory" (BDI), considering pathological a cut-off score equal or greater than 16. Results: 27.2% T2DM subjects had significant symptoms of DD compared with 12.1% in the control group (p<0.01). BDI score was higher among T2DM when compared with controls (12±9.6 vs. 7.4±5, p<0.0001). The proportion of females (68% vs. 37%, p<0.0001), subjects without an active job (68% vs. 45%, p=0.01) and singles (38% vs. 18%, p=0.007) was greater among T2DM with a BDI≥16. Subjects with criteria for DD had a higher BMI (31.99±5.96 vs. 30.53±5.62, p=0.03). Fasting plasma glucose was higher among T2DM with a BDI≥16 (162±70 vs. 147±45 mg/dl, p=0.02) as well as HbA1c levels (7.9±1.8% vs. 7.4±1.4%, p=0.01), triglycerides (203±183 vs. 161±103 mg/dl; p=0.03) and LDL-cholesterol (112±31 vs. 104±35 mg/dl; p=0.03). Gender, marital status, BMI and triglycerides were independently related to the presence of DD after a logistic regression model. Conclusions: Relevant depressive symptoms are more prevalent among Mediterranean T2DM subjects than in general population. Main clinical correlators of significant depressive symptoms are gender, marital status and BMI.


Assuntos
Depressão/diagnóstico , Transtorno Depressivo/diagnóstico , Diabetes Mellitus Tipo 2/sangue , Idoso , Depressão/epidemiologia , Transtorno Depressivo/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Masculino , Ilhas do Mediterrâneo/epidemiologia , Pessoa de Meia-Idade , Prevalência , Espanha/epidemiologia
8.
Opt Lett ; 40(7): 1452-5, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25831357

RESUMO

Vanadium dioxide (VO(2)) is a metal-insulator transition (MIT) oxide recently used in plasmonics, metamaterials, and reconfigurable photonics. Because of the MIT, VO(2)shows great change in its refractive index allowing for ultra-compact devices with low power consumption. We theoretically demonstrate a transverse electric (TE) and a transverse magnetic (TM) pass polarizer with an ultra-compact length of only 1 µm and tunable using the MIT of the VO2. During the insulating phase, both devices exhibit insertion losses below 2 dB at 1550 nm. Changing to the metallic phase, the unwanted polarization is attenuated above 15 dB while insertion losses are kept below 3 dB. Broadband operation over a range of 60 nm is also achieved.

9.
Gastroenterol. latinoam ; 26(1): 9-16, ene.-mar. 2015. tab
Artigo em Espanhol | LILACS | ID: lil-766827

RESUMO

Irritable bowel syndrome (IBS) is a psychosomatic disease whose prevalence has increased considerably in recent years. IBS tends to present comorbidity with other psychopathological conditions such as anxiety, phobias, hypochondria and depression, which makes the medical and psychotherapeutic treatment more complex. There is little empirical evidence on psychotherapeutic treatments to help patients cope with these symptoms. The purpose if this study is to describe the narratives of patients with IBS and explore the role that these narratives play in the establishment and persistence of the disease. Two female IBS-patients were selected and an in depth interview was conducted. The dialogue was transcribed and data were analyzed using the biographical approach. The results show that patients have high levels of alexithymia, operational thinking and difficulties in emotional expression; confirming the main features of psychosomatic personality. It is proposed to define specific psychotherapeutic approaches for each patient according to their personality inferred through their narratives, rather than a unified approved technique for all patients with this disease...


El síndrome de intestino irritable (SII) es una enfermedad psicosomática cuya prevalencia ha aumentado considerablemente en los últimos años. Tiende a presentar comorbilidad con otros cuadros psicopatológicos como la ansiedad, fobias, hipocondría y depresión, lo cual otorga mayor complejidad al tratamiento médico y psicoterapéutico. Existe escasa evidencia empírica sobre tratamientos psicoterapéuticos que ayuden a estos pacientes a lidiar con la sintomatología. El presente trabajo tuvo por objetivo describir las narrativas de pacientes que padecen SII y explorar el rol que cumplen estas narrativas en la constitución y mantenimiento de la enfermedad. Se seleccionaron dos pacientes de sexo femenino con diagnóstico médico de SII y se realizó una entrevista en profundidad. El diálogo fue transcrito a texto y los datos fueron analizados desde el enfoque biográfico. Los resultados muestran que las pacientes padecen altos niveles de alexitimia, pensamiento operatorio y dificultades en la expresión emocional; confirmando las principales características de la personalidad psicosomática. Se propone definir abordajes psicoterapéutico específicos a cada paciente de acuerdo a su personalidad inferida a través de sus narrativas, más que una técnica homologada unificada para todos los pacientes que padecen esta enfermedad...


Assuntos
Humanos , Adulto , Feminino , Pessoa de Meia-Idade , Sintomas Afetivos , Transtornos Psicofisiológicos , Síndrome do Intestino Irritável/psicologia , Psicoterapia , Síndrome do Intestino Irritável/terapia
10.
Opt Lett ; 38(15): 2842-5, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23903158

RESUMO

A novel ultracompact (8 µm length) hybrid silicon-plasmonic TM-TE converter is reported. The conversion is achieved during a partial power coupling between a waveguide and a hybrid plasmonic parallel waveguide. The impact of different types of metals is also analyzed. At a wavelength of 1.55 µm, the device has an extinction ratio (ER) of 27.6 dB and insertion loss (IL) of 1.75 dB. Furthermore, an optical bandwidth as large as 100 nm is achieved with ERs higher than 25 dB and ILs below 2 dB.

11.
Opt Lett ; 37(17): 3504-6, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22940930

RESUMO

In this Letter, we demonstrate a highly efficient, compact, high-contrast and low-loss silicon slow wave modulator based on a traveling-wave Mach-Zehnder interferometer with two 500 µm long slow wave phase shifters. 40 Gb/s operation with 6.6 dB extinction ratio at quadrature and with an on-chip insertion loss of only 6 dB is shown. These results confirm the benefits of slow light as a means to enhance the performance of silicon modulators based on the plasma dispersion effect.

12.
Opt Express ; 20(13): 14698-704, 2012 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-22714530

RESUMO

We present an optimized design for a 10G- differential-phase-shift-keyed (DPSK) receiver based on a silicon-on-insulator (SOI) unbalanced tunable Mach-Zehnder interferometer (MZI) switch in sequence with a Mach-Zehnder delay interferometer (MZDI). The proposed design eliminates the limitation in sensitivity of the device produced by the waveguide propagation losses in the delay line. A 2.3 dB increase in receiver sensitivity at a bit-error-rate (BER) of 10(-9) is experimentally measured over a standard implementation. The enhanced sensitivity is achieved with zero power consumption by tuning the operating wavelength or with less than 5 mW for a fixed wavelength using microheaters. Also the foot-print of the device is minimized to 0.11 mm(2) by the use of compact spirals.


Assuntos
Interferometria/instrumentação , Processamento de Sinais Assistido por Computador/instrumentação , Telecomunicações/instrumentação , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Sensibilidade e Especificidade
13.
Opt Lett ; 37(10): 1721-3, 2012 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-22627549

RESUMO

We describe and demonstrate experimentally a method for photonic mixing of microwave signals by using a silicon electro-optical Mach-Zehnder modulator enhanced via slow-light propagation. Slow light with a group index of ~11, achieved in a one-dimensional periodic structure, is exploited to improve the upconversion performance of an input frequency signal from 1 to 10.25 GHz. A minimum transmission point is used to successfully demonstrate the upconversion with very low conversion losses of ~7 dB and excellent quality of the received I/Q modulated QPSK signal with an optimum EVM of ~8%.

14.
Opt Express ; 19(21): 20876-85, 2011 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-21997097

RESUMO

While current optical communication networks efficiently carry and process huge amounts of digital information over large and medium distances, silicon photonics technology has the capacity to meet the ceaselessly increasing demand for bandwidth via energy efficient, inexpensive and mass producible short range optical interconnects. In this context, handling electrical-to-optical data conversion through compact and high speed electro-optical modulators is of paramount importance. To tackle these challenges, we combine the attractive properties of slow light propagation in a nanostructured periodic waveguide together with a high speed semiconductor pn diode, and demonstrate a highly efficient and mass manufacturable 500 µm-long silicon electro-optical device, exhibiting error free modulation up to 20 Gbit/s. These results, supported by modulation rate capabilities reaching 40 Gbit/s, pave a foreseeable way towards dense, low power and ultra fast integrated networks-on-chip for future chip-scale high performance computing systems.

15.
Eur J Nutr ; 49(6): 321-6, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20108098

RESUMO

BACKGROUND: Important health benefits have been reported recently to phytate intake. This includes the prevention of pathological calcifications such as renal calculi, dental calculi and cardiovascular calcification, due its action as crystallization inhibitor of calcium salts, and as preventive of cancer. AIM OF STUDY: The aim of this study was to establish a relation between the intake of phytate, through consumption of typical components of the Mediterranean diet (including nuts), and its excretion in urine. METHODS: This study recruited participants from subjects included in a larger trial (PREDIMED) of food habits, that were assigned to one of two diet groups: (1) the Mediterranean diet with low proportion of phytate-rich food group, where participants were asked to maintain their usual diet; and (2) the Mediterranean diet with high proportion of phytate-rich food group, where participants were asked to increase phytate-rich foods in their diet. Phytate intake was assessed on the basis of a food frequency questionnaire. Urinary phytate excretion was determined in 2-h urine samples. RESULTS: The overall phytate consumption of the Mediterranean diet with high proportion of phytate-rich food group (672 +/- 50 mg) was significantly higher than the Mediterranean diet with low proportion of phytate-rich food group (422 +/- 34 mg), representing a 59% difference. Urinary phytate excretion was also significantly higher (54%) in the Mediterranean diet with high proportion of phytate-rich food group (1,016 +/- 70 microg/L) than the Mediterranean diet with low proportion of phytate-rich food group (659 +/- 45 microg/L). CONCLUSIONS: Mediterranean diets high in whole cereals, legumes and nuts compared to Mediterranean diets low in these phytate-rich foods increase the urinary phytate excretion in humans.


Assuntos
Dieta Mediterrânea , Ácido Fítico/administração & dosagem , Ácido Fítico/urina , Idoso , Calcinose/prevenção & controle , Neoplasias Colorretais/prevenção & controle , Estudos Transversais , Grão Comestível/química , Fabaceae/química , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nozes/química , Sementes/química , Inquéritos e Questionários
16.
Opt Express ; 17(24): 21986-91, 2009 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-19997443

RESUMO

High speed modulation based on a compact silicon ring resonator operating in depletion mode is demonstrated. The device exhibits an electrical small signal bandwidth of 19 GHz. The device is therefore a candidate for highly compact, wide bandwidth modulators for a variety of applications.


Assuntos
Dispositivos Ópticos , Óptica e Fotônica , Silício/química , Eletrônica/instrumentação , Microscopia Eletrônica de Varredura/métodos , Fótons , Refratometria
17.
Opt Express ; 17(11): 9204-11, 2009 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-19466170

RESUMO

We modelled strong slow wave modulation enhancement in a rib corrugated waveguide with respect to a conventional rib waveguide, both embedded in a reverse biased pn junction. This enhancement is characterized in terms of effective index change versus reverse bias variations from 0V to -10V and for moderate group velocities varying in the range 0.02c to 0.15c. Interaction lengths and insertion losses below 750 microm and 3dB are respectively found for voltage variations in the range -8V to -10V. Furthermore, the device electrical modulation bandwidth is expected to be higher than 10 GHz.


Assuntos
Eletrônica/instrumentação , Dispositivos Ópticos , Refratometria/instrumentação , Telecomunicações/instrumentação , Desenho Assistido por Computador , Desenho de Equipamento , Análise de Falha de Equipamento , Micro-Ondas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
18.
J Periodontal Res ; 44(5): 616-21, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-18973518

RESUMO

BACKGROUND AND OBJECTIVE: Dental calculus occurs as a consequence of supersaturation of saliva with respect to calcium phosphates. This mineralization of dental plaque can be delayed by the presence of crystallization inhibitors, such as pyrophosphate or bisphosphonates. Phytate inhibits brushite and hydroxyapatite crystallization and has the potential to prevent dental calculi formation. The aim of the present study was to examine the effects of phytate and zinc, administered in a mouthwash solution, to prevent the formation of dental calculus. MATERIAL AND METHODS: Healthy dental plaque-forming volunteers (n = 25) took part in a randomized, double-blind, three-period crossover clinical study to assess the efficacy of a phytate-containing mouthwash in relation to control and placebo effects. Subjects rinsed their mouths for 1 min, twice each day, with 20 mL of the test solution, without ingestion. Mouthwash efficacy was assessed through quantification of the amounts of calcium, phosphorus and magnesium present in the residues obtained by dental cleaning, performed by a single trained examiner. RESULTS: A good correlation was found among total calcium, magnesium and phosphorus in calcified dental plaque residues, indicating that any of these variables is adequate for evaluating the reduction of plaque crystallization as calcium phosphate. A statistically significant decrease in total calcium, magnesium and phosphorus was found in the phytate-treatment period compared with control and placebo periods, demonstrating the efficacy of the proposed treatment in reducing dental calculus formation. CONCLUSION: The high efficacy of phytate in reducing dental calculus formation suggests that this substance may be an effective treatment for preventing the development of calculus deposits.


Assuntos
Anti-Infecciosos Locais/uso terapêutico , Cálculos Dentários/prevenção & controle , Antissépticos Bucais/uso terapêutico , Ácido Fítico/uso terapêutico , Triclosan/uso terapêutico , Adolescente , Adulto , Idoso , Cálcio/análise , Fosfatos de Cálcio/antagonistas & inibidores , Estudos Cross-Over , Cristalização , Placa Dentária/química , Método Duplo-Cego , Durapatita/antagonistas & inibidores , Feminino , Humanos , Magnésio/análise , Masculino , Pessoa de Meia-Idade , Fósforo/análise , Placebos , Adulto Jovem , Zinco/uso terapêutico
19.
Opt Lett ; 32(6): 635-7, 2007 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-17308585

RESUMO

Coupled-cavity waveguides (CCWs) allow light propagation with strong field confinement in the cavities and small group velocity, which greatly enhances the efficiency of nonlinear effects. In addition, guided modes have zero dispersion at the central region of the transmission miniband. We show that CCWs created in planar photonic crystals, in which index guiding is required in some spatial dimensions, are intrinsically lossy in the region of zero dispersion, which strongly limits their use in nonlinear applications and devices.

20.
Opt Express ; 15(11): 7058-65, 2007 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-19547023

RESUMO

A polarization insensitive technique for highly efficient coupling between SOI waveguides and high mode field diameter single-mode fibers is reported. The proposed coupling structure is based on an inverted taper structure coupled to a fiber-adapted waveguide. The fiber-adapted waveguide is made by using the SiO(2) layer under the Si waveguiding layer of the SOI wafer thus avoiding the use of extra materials such as polymers. The proposed coupling structure is aimed for being integrated with V-groove auto-alignment techniques. Coupling losses of 3.5dB and 3.7dB to 8mum mode field diameter single-mode fibers have been estimated by means of 3D-BPM simulations for TE and TM polarizations respectively and a 1550nm input signal wavelength.

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