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1.
Allergy ; 73(8): 1575-1596, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29318628

RESUMEN

Hereditary Angioedema (HAE) is a rare and disabling disease. Early diagnosis and appropriate therapy are essential. This update and revision of the global guideline for HAE provides up-to-date consensus recommendations for the management of HAE. In the development of this update and revision of the guideline, an international expert panel reviewed the existing evidence and developed 20 recommendations that were discussed, finalized and consented during the guideline consensus conference in June 2016 in Vienna. The final version of this update and revision of the guideline incorporates the contributions of a board of expert reviewers and the endorsing societies. The goal of this guideline update and revision is to provide clinicians and their patients with guidance that will assist them in making rational decisions in the management of HAE with deficient C1-inhibitor (type 1) and HAE with dysfunctional C1-inhibitor (type 2). The key clinical questions covered by these recommendations are: (1) How should HAE-1/2 be defined and classified?, (2) How should HAE-1/2 be diagnosed?, (3) Should HAE-1/2 patients receive prophylactic and/or on-demand treatment and what treatment options should be used?, (4) Should HAE-1/2 management be different for special HAE-1/2 patient groups such as pregnant/lactating women or children?, and (5) Should HAE-1/2 management incorporate self-administration of therapies and patient support measures?


Asunto(s)
Angioedemas Hereditarios/diagnóstico , Angioedemas Hereditarios/tratamiento farmacológico , Enfermedades Raras/diagnóstico , Enfermedades Raras/tratamiento farmacológico , Adolescente , Adulto , Cuidados Posteriores , Angioedemas Hereditarios/prevención & control , Niño , Proteína Inhibidora del Complemento C1/genética , Consenso , Femenino , Directrices para la Planificación en Salud , Humanos , Lactancia , Masculino , Medicina de Precisión , Embarazo , Enfermedades Raras/prevención & control , Terminología como Asunto , Adulto Joven
3.
Nanotechnology ; 28(8): 085702, 2017 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-28045010

RESUMEN

Recently, black phosphorus quantum dots were fabricated experimentally. Motivated by these experiments, we theoretically investigate the electronic and optical properties of rectangular phosphorene quantum dots (RPQDs) in the presence of an in-plane electric field and a perpendicular magnetic field. The energy spectra and wave functions of RPQDs are obtained numerically using the tight-binding approach. We find edge states within the band gap of the RPQD which are well separated from the bulk states. In an undoped RPQD and for in-plane polarized light, due to the presence of well-defined edge states, we find three types of optical transitions which are between the bulk states, between the edge and bulk states, and between the edge states. The electric and magnetic fields influence the bulk-to-bulk, edge-to-bulk, and edge-to-edge transitions differently due to the different responses of bulk and edge states to these fields.

4.
Acta Endocrinol (Buchar) ; 12(2): 150-156, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-31149080

RESUMEN

CONTEXT: Angiotensin converting enzyme 2 (ACE2) is highly expressed in the kidney and cleaves angiotensin II to Angiotensin (1-7), annihilating the deleterious effects of angiotensin II which is known to be a strong activator of oxidative stress. OBJECTIVE: We aimed to evaluate the relationship of oxidative stress to urinary ACE2 (uACE2) in type 2 diabetes mellitus (T2DM) patients. DESIGN: We included consecutive normo or microalbuminuric T2DM patients in an observational transversal study. Routine laboratory investigations, plasma malondialdehyde (MDA, fluorimetric thiobarbituric method) as a marker of prooxidant capacity and superoxide dismutase (SOD, cytochrome reduction method) and catalase (CAT) activity (in erythrocyte lysate by the modification of absorbance method) as two measures of serum antioxidant capacity and uACE2 (ELISA method) were assessed. RESULTS: MDA showed a negative correlation with SOD (r=-0.44, p=0.001), CAT (r=-0.37, p=0.006), uACE2 (r=-0.33, p=0.016) and a positive correlation with glycated haemoglobin (HbA1c) (r=0.49, p<0.001) and associated cardiovascular disease (r=0.42, p=0.001). CAT as also positively correlated to uACE2 (r=0.29, p=0.037). SOD was also negatively correlated with glycemia (r=-0.71, p<0.001) and HbA1c (r=-0.53, p<0.001). Patients with lower MDA (when divided according to median value of 3.88 nmol/mL) had higher uACE2 57.15(40.3-71.2) pg/mL compared to 38.5(31.8-45.95) pg/mL in patients with higher MDA (p<0.001). In multivariate logistic regression uACE2 was the only predictor for MDA above or below its median (OR=0.94, 95%CI[0.90-0.98], p=0.002). CONCLUSION: Increased prooxidant serum capacity is associated with lower uACE2 levels in T2DM patients.

5.
Allergy ; 70(12): 1661-4, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26248961

RESUMEN

The factors influencing the heterogeneous clinical manifestation of hereditary angioedema due to C1-INH deficiency (C1-INH-HAE) represent one of the oldest unsolved problems of the disease. Considering that factor XII (FXII) levels may affect bradykinin production, we investigated the contribution of the functional promoter polymorphism F12-46C/T in disease phenotype. We studied 258 C1-INH-HAE patients from 113 European families, and we explored possible associations of F12-46C/T with clinical features and the SERPING1 mutational status. Given that our cohort consisted of related subjects, we implemented generalized estimating equations (GEEs), an extension of the generalized linear model accounting for the within-subject correlation. F12-46C/T carriers exhibited a significantly delayed disease onset (P < 0.001) and did not need long-term treatment (P = 0.02). In a GEE linear regression model, the presence of F12-46C/T was significantly associated with a 7-year delay in disease onset (P < 0.0001) regardless of SERPING1 mutational status. It is concluded that F12-46C/T carriage acts as an independent modifier of C1-INH-HAE severity.


Asunto(s)
Factor XII/genética , Estudios de Asociación Genética , Angioedema Hereditario Tipos I y II/genética , Polimorfismo de Nucleótido Simple , Adolescente , Adulto , Anciano , Niño , Preescolar , Proteínas Inactivadoras del Complemento 1/genética , Proteína Inhibidora del Complemento C1 , Análisis Mutacional de ADN , Femenino , Genotipo , Humanos , Lactante , Masculino , Persona de Mediana Edad , Mutación , Fenotipo , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Adulto Joven
6.
Allergy ; 68(1): 118-24, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23121116

RESUMEN

BACKGROUND: Hereditary angioedema (HAE) is a disease characterized by recurrent tissue swelling affecting various body locations. Recent literature shows that patients with frequent attacks may benefit from long-term prophylaxis. This study evaluated the safety and prophylactic effect of weekly administrations of recombinant C1INH (rhC1INH). METHODS: Patients with a history of HAE attacks occurring ≥every 2 weeks received a once weekly administration of 50 U/kg rhC1INH. Hereditary angioedema attack history was collected at screening. Breakthrough attacks during the study were recorded at each visit. Following a 2-week run-in period, HAE patients received 8 weekly rhC1INH administrations and were followed-up for an additional 6 weeks. Efficacy was evaluated by comparing the HAE attack incidence during the treatment period to the historical attacks over the previous 2 years. Safety evaluation was based on clinical laboratory and adverse events (AEs) reports. RESULTS: The 25 participants reported a mean of 0.9 attacks/week over the past 2 years. The mean breakthrough attack rate during the treatment period was 0.4 attacks/week (95% CI 0.28-0.56). A total of 30 treatment-emergent-AEs were reported in 13 patients, all mild to moderate. One patient died from a laryngeal attack 25 days after last study drug administration. The only possible drug related AEs reported were dry mouth, dizziness and anxiety in one patient and hypotension in another. There were no allergic AEs and no neutralizing antibodies observed. CONCLUSIONS: Weekly administrations of 50 U/kg rhC1INH appeared to reduce the frequency of HAE attacks and were generally safe and well tolerated.


Asunto(s)
Proteína Inhibidora del Complemento C1/uso terapéutico , Angioedema Hereditario Tipos I y II/prevención & control , Proteínas Recombinantes/uso terapéutico , Adolescente , Adulto , Anciano , Proteína Inhibidora del Complemento C1/administración & dosificación , Proteína Inhibidora del Complemento C1/efectos adversos , Proteína Inhibidora del Complemento C1/farmacocinética , Femenino , Angioedema Hereditario Tipos I y II/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Proyectos Piloto , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/farmacocinética , Resultado del Tratamiento , Adulto Joven
7.
Clin Exp Allergy ; 42(6): 929-35, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22909164

RESUMEN

BACKGROUND: Hereditary angioedema (HAE) owing to C1 inhibitor deficiency is an autosomal dominant disorder, characterized by recurrent, potentially life-threatening, localized attacks of tissue swelling. Current treatment involves the infusion of C1 inhibitor protein (C1-INH) isolated from human plasma. OBJECTIVES: This open-label extension to a European, Israeli and Argentinean randomized study (NCT00262301) aimed to investigate the efficacy and safety of recombinant human C1 inhibitor (rhC1-INH) as a first-line treatment following an HAE attack, together with its effect on subsequent attacks. METHODS: An HAE-specific visual analogue scale (VAS) 0-100 mm was used by patients to assess the severity of attack at four anatomical locations. Patients were treated with one, single-vial, fixed-dose of rhC1-INH (2100 U), followed by up to two further vials at the investigators discretion. The primary end-point was the time from first rhC1-INH injection to first onset of relief of symptoms (≥ 20 mm decrease on VAS). Response to treatment was defined as the onset of relief within 4 h. RESULTS: A total of 57 patients were treated for 194 HAE attacks. Overall, sustained relief of symptoms was achieved in 87% of rhC1-INH-treated patients within 4 h of treatment, with 57% of attacks requiring only one vial of rhC1-INH. When categorized by successive attacks experienced by individual patients, the response rate to rhC1-INH treatment was 96%, 83%, 87%, 80% and 80% for attacks 1-5 respectively. Treatment with rhC1-INH was well tolerated, with no discontinuations owing to treatment-emergent adverse events and no adverse events relating to immunogenicity. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with rhC1-INH provides fast-onset relief for an HAE attack, with a high rate of therapeutic response maintained throughout subsequent attacks.


Asunto(s)
Angioedemas Hereditarios/tratamiento farmacológico , Proteína Inhibidora del Complemento C1/uso terapéutico , Inactivadores del Complemento/uso terapéutico , Adolescente , Adulto , Anciano , Proteína Inhibidora del Complemento C1/administración & dosificación , Proteína Inhibidora del Complemento C1/efectos adversos , Inactivadores del Complemento/administración & dosificación , Inactivadores del Complemento/efectos adversos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/uso terapéutico , Factores de Riesgo , Resultado del Tratamiento , Adulto Joven
8.
Urologe A ; 58(6): 617-626, 2019 Jun.
Artículo en Alemán | MEDLINE | ID: mdl-31209530

RESUMEN

Urinary incontinence and pelvic organ prolapse (POP) are increasing due to demographic factors. Increasing life expectancy and sociocultural demands of women require successful treatments that also have low complication rates. Classic open procedures such as colposuspension or colposacropexy (native tissue repair as well as mesh procedures) are experiencing a renaissance due to the current critical view of mesh-repair pelvic floor surgery and continue to be of great importance. With suitable patient selection, long-term results of abdominal procedures are on a par with minimally invasive techniques. Cosmetically acceptable results can be achieved with optimized incisions. The therapeutically relevant target for apical fixation is the elevation angle of the vagina (EAV). Minimally invasive mesh-based primary reconstructions and interventions for POP recurrence proved to be superior to conventional procedures due to good long-term results, lower recurrence rates and reduced early and late complication rates when anatomically correct and gentle surgery is performed with a critical selection of textile implants. Abdominal procedures are not inferior to minimally invasive techniques when instrumental suturing techniques and modern instruments are used. Adequate and critical information about surgical options and possible risks of complications should be provided in a timely manner. Education and training in modern diagnostics as well as in abdominal and current minimally invasive techniques and complication management should be implemented according to the guidelines and recommendations of professional societies, the Food and Drug Administration and the European Network of Information Centres.


Asunto(s)
Procedimientos Quirúrgicos Ginecológicos/métodos , Laparoscopía , Diafragma Pélvico/diagnóstico por imagen , Prolapso de Órgano Pélvico/cirugía , Procedimientos de Cirugía Plástica/métodos , Procedimientos Quirúrgicos Urológicos/métodos , Femenino , Humanos , Prolapso de Órgano Pélvico/diagnóstico por imagen , Mallas Quirúrgicas , Técnicas de Sutura , Resultado del Tratamiento , Incontinencia Urinaria/cirugía , Vagina
9.
Urologe A ; 56(12): 1576-1582, 2017 Dec.
Artículo en Alemán | MEDLINE | ID: mdl-29134243

RESUMEN

There has been an overall increase in pelvic organ prolapse due to demographic changes (increased life expectancy). Increasing sociocultural demands of women require treatments that are more effective with methods that are more successful. In the treatment of pelvic floor insufficiency and uterovaginal prolapse, pelvic floor reconstructions with mesh implants have proven to be superior to conventional methods such as the classic colporrhaphy, reconstructions with biomaterial, and native tissue repair in appropriately selected patients and when applying exact operation techniques, especially because of good long-term results and low recurrence rates. When making a systematic therapy plan, one should adhere to certain steps, for example, a pelvic floor reconstruction should be undertaken before performing the corrective procedure for incontinence. The approach, if vaginal, laparoscopic, or abdominal should be chosen wisely, taking into consideration the required space of action, in such a way that none or only minimal collateral damage related to the operation occurs. The use of instrumental suturing techniques and operation robots are advantageous in the case of difficult approaches and limited anatomical spaces. In principle, the surgeon who implants meshes should be able to explant them! The surgical concept of mesh-related interventions in the pelvis must meet established rules. "Implant as little mesh as possible and only as much suitable (!) mesh as absolutely necessary!" In the case of apical direct fixations, a therapeutically relevant target variable is the elevation angle of vagina (EAV). Established anatomical fixation points are preferable. A safe distance between implants and vulnerable tissue is to be maintained. Mesh-based prolapse repairs are indicated in recurrences, in primary situations, in combined defects of the anterior compartment, in central defects of multimorbid and elderly patients, and above all, when organ preservation is wanted. Native connective tissue structures are to be preserved, strengthened and reconstructed to restore altered functions. Practical skills for highly specialized mesh-based operations as well as effective techniques for complication management should be taught in interdisciplinary specialist courses.


Asunto(s)
Trastornos del Suelo Pélvico/cirugía , Mallas Quirúrgicas , Prolapso Uterino/cirugía , Femenino , Humanos , Recurrencia , Reoperación/métodos , Sacro/cirugía , Anclas para Sutura , Incontinencia Urinaria/etiología , Incontinencia Urinaria/cirugía , Vagina/cirugía
10.
Rev Pneumol Clin ; 62(3): 179-82, 2006 Jun.
Artículo en Francés | MEDLINE | ID: mdl-16840996

RESUMEN

Sclerosing epithelioid fibrosarcoma is a rare tumor recently described. The histological presentation can be confused with certain soft tissue benign tumors and certain sarcomas. Metastatic spread is usually late in the natural course of the disease. We report a case of recurrent sclerosing epithelioid fibrosarcoma with pleural metastases which developed ten years after surgical resection of the primary tumor. The tumor was formed by small uniform round epithelioid cells with a clear cytoplasm. The tumor cells were strongly positive for vimentin. This clinical case is discussed in light of other cases reported in the literature.


Asunto(s)
Fibrosarcoma/secundario , Neoplasias Pleurales/secundario , Neoplasias de los Tejidos Blandos/patología , Anciano , Fibrosarcoma/química , Fibrosarcoma/cirugía , Humanos , Masculino , Neoplasias Pleurales/química , Neoplasias de los Tejidos Blandos/cirugía , Factores de Tiempo , Vimentina/análisis
11.
Eur Ann Allergy Clin Immunol ; 37(7): 279-82, 2005 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16285234

RESUMEN

According to physician, Aspirin and NSAIDS hypersensitivity are causing three major problems: how to make the diagnosis? Which treatment are to he given to these patients? What kind of anti-inflammatory drugs are to be prescribed? For these last three years, several articles regarding these matters were being published.


Asunto(s)
Antiinflamatorios no Esteroideos/efectos adversos , Aspirina/efectos adversos , Hipersensibilidad a las Drogas/diagnóstico , Antiinflamatorios no Esteroideos/inmunología , Aspirina/inmunología , Hipersensibilidad a las Drogas/fisiopatología , Humanos
12.
Clin Biochem ; 48(13-14): 860-5, 2015 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-26006757

RESUMEN

OBJECTIVES: Adiponectin is an insulin-sensitizing, anti-inflammatory adipokine with anti-atherogenic actions in the general population. In dialysis patients it is unclear whether adiponectin conserves its protective value or is, on the contrary, associated to worse prognosis. We assessed the predictive value of adiponectin for atherosclerosis related cardiovascular events in type 2 diabetic dialysis patients. DESIGN AND METHODS: Prevalent diabetic dialysis patients from three dialysis units (n=77) were enrolled in a 3years' prospective observational study. Serum adiponectin, clinical and laboratory parameters were determined at baseline; new occurrence of atherosclerosis related events (coronary events, atherosclerosis obliterans, and stroke) was recorded. RESULTS: Baseline adiponectin was 17.25(9.53-31.97) µg/mL and significantly correlated to HDL cholesterol (r=0.29, p=0.01), triglycerides (r=-0.40, p=0.0004), ferritin (r=-0.29, p=0.02), transferrin (r=-0.28, p=0.02), and uric acid (r=-0.24, p=0.04). In multivariate analysis association to triglycerides (p=0.001), HDL cholesterol (p=0.01) and ferritin (p=0.04) remained significant. 36 new fatal and non-fatal new cardiovascular events occurred, 29 patient died. Cox proportional regression analysis showed that adiponectin below or above a ROC-derived cut-off of 27.33µg/mL significantly influenced event-free survival: hazard ratio (HR) 2.48, 95% confidence interval (CI) (1.09-5.66), p=0.031 along with fasting glucose HR 1.01, 95%CI(1.00-1.02), p=0.01 and history of cardiovascular events at inclusion HR 3.16, 95%CI(1.36-7.32), p=0.007. In multivariate analysis baseline adiponectin HR 5.02, 95%CI(0.98-25.06), p=0.05 and glycemia HR 1.01, 95%CI(1.00-1.02), p=0.01 influenced event-free survival. Adiponectin also predicted cardiovascular events in patients without cardiovascular disease at inclusion but was not associated to overall mortality. CONCLUSIONS: In diabetes dialysis patients low adiponectin favors occurrence of atherosclerosis related cardiovascular events.


Asunto(s)
Adiponectina/sangre , Enfermedades Cardiovasculares/diagnóstico , Diabetes Mellitus/sangre , Diálisis Renal , Aterosclerosis/sangre , Enfermedades Cardiovasculares/sangre , Estudios de Cohortes , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Análisis Multivariante , Modelos de Riesgos Proporcionales , Análisis de Regresión , Resultado del Tratamiento
13.
IEEE Trans Pattern Anal Mach Intell ; 9(1): 153-60, 1987 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21869387

RESUMEN

The problems in computer vision range from edge detection and segmentation at the lowest level to the problem of cognition at the highest level. This correspondence describes the organization and operation of a semantic network array processor (SNAP) as applicable to high level computer vision problems. The architecture consists of an array of identical cells each containing a content addressable memory, microprogram control, and a communication unit. The applications discussed in this correspondence are the two general techniques, discrete relaxation and dynamic programming. While the discrete relaxation is discussed with reference to scene labeling and edge interpretation, the dynamic programming is tuned for stereo.

14.
Int Urol Nephrol ; 44(4): 1151-7, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21993769

RESUMEN

BACKGROUND: Experimental studies have shown that adiponectin has antiproteinuric and nephroprotective effects. The purpose of the study was to assess the value of plasma adiponectin as a predictor of proteinuria in type 2 diabetes (T2D) patients. METHODS: In this one-year prospective follow-up study, we included T2D patients with positive visual test for microalbuminuria (Micral) and negative visual test for proteinuria. Exclusion criteria were: glomerular filtration ratio (GFR) < 30 ml/min, acute infection/inflammation, uncontrolled hypertension, and atherosclerotic complications. The main outcome measure was the change in urinary albumin/creatinine ratio (UACR) after 1 year follow-up (Δ UACR). RESULTS: Fifty-six patients (66% males) completed the study. Their initial mean UACR was 81.58 ± 26.42 mg/g and mean GFR was 81.15 ± 3.96 ml/min. At baseline, simple regression disclosed significant correlations between UACR and plasma adiponectin (r = 0.54, P = 0.00002) and GFR (r = -0.28, P = 0.03); in multiple regression analysis, plasma adiponectin remained the only predictor of UACR (P = 0.00007). Baseline plasma adiponectin was significantly correlated to body mass index (r = -0.28, P = 0.04), waist circumference (r = -0.27, P = 0.05), HDL cholesterol (r = 0.35, P = 0.01), and LDL cholesterol (r = 0.27, P = 0.04). Baseline plasma adiponectin significantly correlated in simple (r = -0.38, P = 0.004) and multiple regression (P = 0.04) to Δ UACR. When patients were divided according to Δ UACR in nonprogressors (Δ UACR < 0) and progressors (Δ UACR > 0), logistic regression showed that baseline GFR (OR = 1.04, CI95%: 1.00-1.09, P = 0.04) and plasma adiponectin (OR = 1.16, CI95%: 1.02-1.32, P = 0.02) were the only factors that predicted whether the patient would be a progressor or not. CONCLUSION: In T2D patients, lower plasma adiponectin levels seem to be predictive of increased UACR.


Asunto(s)
Adiponectina/sangre , Albuminuria/metabolismo , Creatinina/sangre , Creatinina/orina , Diabetes Mellitus Tipo 2/metabolismo , Nefropatías Diabéticas/metabolismo , Albuminuria/complicaciones , Índice de Masa Corporal , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/etiología , Nefropatías Diabéticas/fisiopatología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Humanos , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Factores de Tiempo
15.
J Magn Reson ; 208(1): 156-62, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21106419

RESUMEN

Residual second moment of dipolar interactions M(2) and correlation time segmental dynamics distributions were measured by Hahn-echo decays in combination with inverse Laplace transform for a series of unfilled and filled EPDM samples as functions of carbon-black N683 filler content. The fillers-polymer chain interactions which dramatically restrict the mobility of bound rubber modify the dynamics of mobile chains. These changes depend on the filler content and can be evaluated from distributions of M(2). A dipolar filter was applied to eliminate the contribution of bound rubber. In the first approach the Hahn-echo decays were fitted with a theoretical relationship to obtain the average values of the (1)H residual second moment and correlation time <τ(c)>. For the mobile EPDM segments the power-law distribution of correlation function was compared to the exponential correlation function and found inadequate in the long-time regime. In the second approach a log-Gauss distribution for the correlation time was assumed. Furthermore, using an averaged value of the correlation time, the distributions of the residual second moment were determined using an inverse Laplace transform for the entire series of measured samples. The unfilled EPDM sample shows a bimodal distribution of residual second moments, which can be associated to the mobile polymer sub-chains (M(2) ≅ 6.1 rad (2) s(-2)) and the second one associated to the dangling chains M(2) ≅ 5.4 rad(2) s(-2)). By restraining the mobility of bound rubber, the carbon-black fillers induce diversity in the segmental dynamics like the apparition of a distinct mobile component and changes in the distribution of mobile and free-end polymer segments.


Asunto(s)
Algoritmos , Espectroscopía de Resonancia Magnética/métodos , Modelos Químicos , Hollín/análisis , Hollín/química , Simulación por Computador , Protones
16.
Ann Biomed Eng ; 34(9): 1442-51, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16897422

RESUMEN

The interactions of methanol with lipid bilayers were studied by means of molecular dynamics (MD) simulations. Our MD simulations focus on the effect of approximately 11.3 mol% methanol on two fully hydrated dipalmitoylphosphatidylcholine (DPPC) and palmitoyloleoylphosphatidylcholine (POPC) lipid bilayers both in the fluid phase and under equilibrium conditions at 323 and 298 K, respectively. The effects of methanol on bilayers structural characteristics were investigated. In both systems the simulations show that the presence of relatively high concentration of methanol leads to a significant increase in the area per lipid. The increase in the area per lipid is accompanied by a corresponding decrease of the bilayer thickness such that the volume occupied per lipid does not change significantly in the presence of methanol. Other properties such as ordering of phospholipid tails and lateral diffusion of the lipids are also affected significantly by the presence of methanol. Consistent with other previously reported MD simulation studies of bilayers in the presence of methanol (albeit at a significantly smaller concentration of 1 mol%) our study shows very few hydrogen bonding formation between lipids and methanol.


Asunto(s)
Membrana Dobles de Lípidos/química , Metanol/química , Modelos Químicos , Fosfolípidos/química , Enlace de Hidrógeno
17.
Pneumoftiziologia ; 43(1-2): 29-33, 1994.
Artículo en Ro | MEDLINE | ID: mdl-7734984

RESUMEN

The inhalational histamine and metacholine test is a standard procedure to estimate the degree of bronchial reactivity. During the last 10 years the method of continuously generated aerosol inhalation compels recognition. The test consists in the inhalation during 2 minutes, every 5 minutes of a double dosage of drug followed by measurement of MEVS after each step. Thus the dosage response curve is set up. The concentration of the necessary drug dosage for decreasing with 20% of MEVS (PC20 or PD20) are accepted as indices for bronchial reactivity. The method is indicated in cases suspected for atypical bronchial asthma, professional asthma and drug research. The technical and subjective factors interfering the measurements should be taken into account and analysed in order to ensure reproducibility and comparability of the method.


Asunto(s)
Pruebas de Provocación Bronquial/métodos , Histamina , Cloruro de Metacolina , Administración por Inhalación , Hiperreactividad Bronquial/diagnóstico , Pruebas de Provocación Bronquial/instrumentación , Histamina/administración & dosificación , Humanos , Cloruro de Metacolina/administración & dosificación , Reproducibilidad de los Resultados
18.
Artículo en Inglés | MEDLINE | ID: mdl-11970292

RESUMEN

We study the dynamics of the classical Euler buckling of compressed solid membranes. We relate the membrane buckling dynamics to phase ordering phenomena. Membranes develop a wavelike pattern whose wavelength grows, via coarsening, as a power of time. We find that evolving membranes are similar to growing surfaces ("growing interfaces") whose transverse width grows as a power of time. The morphology of the evolving membranes is characterized by the presence of a network of growing ridges where the elastic energy is mostly localized. We used this fact to develop a scaling theory of the buckling dynamics that gives analytic estimates of the coarsening exponents. Our findings show that the membrane buckling dynamics is characterized by a distinct scaling behavior not found in other coarsening phenomena.

19.
Physiologie ; 25(1-2): 83-7, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3133679

RESUMEN

Sinus node recovery time, used as an objective parameter of the sinus node function estimation, may be left out in the situation in which an atrial parasystolic focus is present. The overdrive suppression induced through rapid atrial pacing is without effect upon the protected parasystolic focus, and its firing will disturb the post-drive pause. This situation is noticed in two instances and demonstrated in one case.


Asunto(s)
Arritmias Cardíacas/fisiopatología , Nodo Sinoatrial/fisiopatología , Estimulación Cardíaca Artificial , Electrocardiografía , Atrios Cardíacos/fisiopatología , Humanos , Síndrome del Seno Enfermo/diagnóstico , Sístole , Factores de Tiempo
20.
Med Interne ; 18(3): 265-77, 1980.
Artículo en Inglés | MEDLINE | ID: mdl-7414238

RESUMEN

In fifteen patients with WPW syndrome the standard electrocardiogram, the vector cardiogram and the precordial map were used togther in order to better localize the ventricular pre-excitation. These three noninvasive techniques permit a more precise location of the accessory pathway in WPW syndrome.


Asunto(s)
Electrocardiografía , Vectorcardiografía , Síndrome de Wolff-Parkinson-White/diagnóstico , Adolescente , Adulto , Nodo Atrioventricular/fisiopatología , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Vías Nerviosas
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