Interface bonding in silicon oxide nanocontacts: interaction potentials and force measurements.

The interface bonding between two silicon-oxide nanoscale surfaces has been studied as a function of atomic nature and size of contacting asperities. The binding forces obtained using various interaction potentials are compared with experimental force curves measured in vacuum with an atomic force microscope. In the limit of small nanocontacts (typically <103 nm2) measured with sensitive probes the bonding is found to be influenced by thermal-induced fluctuations. Using interface interactions described by Morse, embedded atom model, or Lennard-Jones potential within reaction rate theory, we investigate three bonding types of covalent and van der Waals nature. The comparison of numerical and experimental results reveals that a Lennard-Jones-like potential originating from van der Waals interactions captures the binding characteristics of dry silicon oxide nanocontacts, and likely of other nanoscale materials adsorbed on silicon oxide surfaces. The analyses reveal the importance of the dispersive surface energy and of the effective contact area which is altered by stretching speeds. The mean unbinding force is found to decrease as the contact spends time in the attractive regime. This contact weakening is featured by a negative aging coefficient which broadens and shifts the thermal-induced force distribution at low stretching speeds.

The FIELDS Instrument Suite for Solar Probe Plus: Measuring the Coronal Plasma and Magnetic Field, Plasma Waves and Turbulence, and Radio Signatures of Solar Transients.

NASA's Solar Probe Plus (SPP) mission will make the first in situ measurements of the solar corona and the birthplace of the solar wind. The FIELDS instrument suite on SPP will make direct measurements of electric and magnetic fields, the properties of in situ plasma waves, electron density and temperature profiles, and interplanetary radio emissions, amongst other things. Here, we describe the scientific objectives targeted by the SPP/FIELDS instrument, the instrument design itself, and the instrument concept of operations and planned data products.

Brooke-Spiegler syndrome - report of four families: treatment with CO2 laser.

BACKGROUND: Brooke-Spiegler syndrome is a well known but rare cutaneous disorder characterized by the presence of multiple trichoepitheliomas and cylindromas. METHODS: Four families with Brooke-Spiegler syndrome are described. RESULTS: Spiradenomas developed on the back in two patients. A CO(2) laser was used to treat facial trichoepitheliomas in two patients with good results. CONCLUSIONS: The large number of facial lesions in this syndrome often produce a significant emotional impact. We believe that it is important to provide patients with a good therapeutic option. CO(2) laser therapy may fill this role.

Fixed drug eruption due to loratadine.

We present the clinical case of a 8-years-old boy suffering a fixed drug reaction attributed to the oral intake of loratadine. He is an atopic child with perennial rhinitis and asthma and marked hypersensitivity to the house-dust mite Dermatophagoides pteronyssinus who is receiving inhaled corticosteroids and b2-agonists ad libitum plus specific immunotherapy with the mite. When the boy received loratadine to alleviate his nasal symptoms he suffered a well-defined erythematous and oedematous plaque in his right elbow that disappeared without treatment in one week. Several methods such as the patch-tests, the UBCT or ultra-brief-challenge test (our version of the peroral provocation one) and the skin biopsy were applied. The UBCT and the skin histopathology were the most important techniques to assure the suspected diagnosis. Other antihistamines such as ebastine and cetirizine as well as some excipients used as controls were all negative. Conventional prick or intradermal skin tests with the drug were not performed because we considered that they were useless in this case.

Foliculitis en penacho / Tufted hair folliculitis

Presentamos tres pacientes, dos mujeres y un varón, con diagnóstico de foliculitis en penacho, caracterizada por áreas de alopecia cicatrizal dentro de las cuales emergen conglomerados pilosos de un único orificio folicular. Una de las pacientes fue tratada con infiltraciones con corticoides y nadifloxacina tópica; la otra, con corticoides tópicos y queratolíticos, y el paciente varón, con isotretinoína oral. En los tres se obtuvo una mejoría parcial. La FEP sería una variante de la foliculitis decalvante, caracterizada por la formación del penacho piloso como fenómeno principal, evolución tórpida y tratamiento dificultoso

Foliculitis en penacho / Tufted hair folliculitis

Presentamos tres pacientes, dos mujeres y un varón, con diagnóstico de foliculitis en penacho, caracterizada por áreas de alopecia cicatrizal dentro de las cuales emergen conglomerados pilosos de un único orificio folicular. Una de las pacientes fue tratada con infiltraciones con corticoides y nadifloxacina tópica; la otra, con corticoides tópicos y queratolíticos, y el paciente varón, con isotretinoína oral. En los tres se obtuvo una mejoría parcial. La FEP sería una variante de la foliculitis decalvante, caracterizada por la formación del penacho piloso como fenómeno principal, evolución tórpida y tratamiento dificultoso (AU)

Zoon's balanitis: presentation of 15 patients, five treated with a carbon dioxide laser.

BACKGROUND: Zoon's balanitis is a chronic erosive process of the penis. The lesions are refractory to conservative topical and some surgical therapy, and frequently require circumcision as a curative measure. METHODS: Fifteen patients with a clinical and histopathologic diagnosis of Zoon's balanitis were studied between October 1991 and October 2001. Five were treated with a carbon dioxide laser. RESULTS: The ages of the patients ranged from 36 to 69 years (average, 50.8 years). All the men were uncircumcised and presented with a discharge and erythematous lesions on the glans penis; the balanopreputial fold was affected in 10 patients and eight had a lesion on the internal surface of the prepuce. One patient was human immunodeficiency virus positive. Five were treated with a carbon dioxide laser. Two relapsed 1 and 3 years later, respectively, and the remaining three have been followed up for 2, 5, and 6 years, respectively, without relapse. One patient developed lichen sclerosus et atrophicus of the prepuce. CONCLUSIONS: We have presented our case study of 15 patients with Zoon's balanitis, and emphasize the possible use of a carbon dioxide laser as an alternative therapy.

Piomiositis no tropical y síndrome de superposición: lupus / Sjõgren / Nontropical pyomyositis and overlap syndrome: systemic lupus erythematosus and Sjõgren syndrome

La Piomiositis (PMS) es una infección primaria del músculo estriado, con progresión insidiosa de una colección purulenta, que se presenta generalmente en áreas tropicales denominándose por esa razón PMS tropical. La incidencia de PMS se ha incrementado últimamente en zonas templadas, denominándose a esta entidad como PMS no tropical, ya que existen algunas características que la diferencian de la PMS clásica. Presentamos el caso de una mujer de 39 años de edad con Síndrome de Superposición, Lupus Erimatoso Sistémico (LES) / Síndrome de Sjõgren (SS), que presentó durante la evolución de su enfermedad una PMS no tropical como ampliación atípica.

Development of cutaneous sarcoidosis in a patient with chronic hepatitis C treated with interferon alpha 2b.

BACKGROUND: Sarcoidosis is a multisystemic granulomatous disorder of unknown etiology that most commonly affects young adults. A probable induction of sarcoidosis by interferons (IFN) has been published. To this date, few cases of cutaneous sarcoidosis inpatients with chronic hepatitis C under interferon treatment have been reported. OBJECTIVE: We describe a 50-year-old woman with chronic hepatitis C who developed lesions of cutaneous sarcoidosis three months after IFN treatment. CONCLUSIONS: The possible role of INF therapy in the development of cutaneous sarcoidosis in a patient with chronic hepatitis C should be considered.

Micosis fungoide folicular / Follicular mycosis fungoides

La micosis fungoide folicular (MFF) es una variante clínica infrecuente de MF. Presentamos el caso de un paciente de 51 años de edad con localización en cuero cabelludo y buena respuesta al tratamiento. Realizamos además una revisión de la literatura

Micosis fungoide folicular / Follicular mycosis fungoides

La micosis fungoide folicular (MFF) es una variante clínica infrecuente de MF. Presentamos el caso de un paciente de 51 años de edad con localización en cuero cabelludo y buena respuesta al tratamiento. Realizamos además una revisión de la literatura (AU)

Carcinoma de mama y síndrome de Sweet / Breast carcinoma and Sweet's syndrome

El síndrome de Sweet es una entidad dermatológica poco frecuente, definida como una dermatosis neutrofílica febril aguda. Esta patología presenta características clínicas bien definidad, y en un porcentaje minoritario de pacientes está asociada a neoplasias sólidas. Presentamos el caso de una paciente de 71 años de edad que consulta debido a la aparición de placas eritemato-edematosas infiltradas y dolorosas en miembro superior y región mamaria derechas, extendiéndose a hemiabdomen homolateral y dorso, precedidas por fiebre y escalofríos. Como antecedentes personales de importancia destaca haber padecido cáncer de mama 4 años antes de la aparición de la dermatosis