A compact-rigid multi-analyser for energy and angle filtering of high-resolution X-ray experiments. Part 2. Efficiency of a single-crystal-comb.

Diffraction instruments using filtering by one or several analyser crystals exist since the 1980s and 1990s at synchrotron radiation sources, but, due to its low efficiency, this filtering is little used on laboratory sources. In order to overcome this limitation, the efficiency of a small diffraction filtering multi-analyzer block (MAD block) realized with a `single-crystal-comb' curved on a rigid support is demonstrated here. The geometry of this curved surface is logarithmic spiral and is optimized to allow multi-filtering over a relatively important diffraction angular range and to be also applicable over an X-ray spectral range. The efficiency of such a small rigid-compact MAD block consisting of this single-crystal-comb generating 20-50 Si(111) single-crystal blades, associated with a block of Soller collimators, is demonstrated. The angle between each crystal is 0.1°, so the measurement range of the comb is 2-5°. The geometry of this system has been optimized for operation with a synchrotron X-ray source over an energy range of 22 keV to 46 keV and could be used with laboratory X-ray sources (Ag Kα1, 22.1 keV). This MAD block complements and exploits the qualities of the `photon-counting' detectors which have very low intrinsic noise. Their joint efficacy is supported by powder pattern measurements of a LaB6 reference sample and of several heterogeneous samples of cultural heritage materials, carried out at 22 keV on the D2AM beamline at the ESRF. Their signal-to-noise ratio is excellent (1000/1) and allows the detection thresholds of the measurements (from 3-1% to 0.1%) to detect minor phases in the studies of `real' heterogeneous materials to be drastically improved.

Evaluación de un programa de educación de tratamiento intensivo en adolescentes con diabetes tipo 1. Seguimiento por dos años / Evaluation of an intensive treatment education program for type 1 diabetes in a group of adolescents. A two year follow up

During the past decade several reports were published showing that intensive treatment of type 1 diabetes can prevent and delay disease-related microvascular complications. However, several problems were reported in children and adolescents such as frequent hypoglycemic episodes and weight gain. The aim of this study was to describe the results of intensified treatment for type 1 diabetes in a group of Argentinean adolescents after a follow-up of two years. Twenty five adolescents with type 1 diabetes older than 10 years with at least one year from diagnosis were selected. All patients received a one-week teaching program during admission to our center. All patients were followed-up monthly during two years. Treatment schedule included 4-5 controls in fasting conditions, two doses of NPH insulin and four doses of regular insulin according to glycemia and the amount of calculated carbohydrate intake. Median age was 13.5 years (range 10 to 19 years). Mean time from diagnosis to inclusion in the study was 3.8 years (range 1.25 to 9 years). Mean total dose of NPH insulin decreased significantly when measured at the inclusion in the study (0.9 IU/kg) and after a year of follow-up 0.8 IU/kg (p 0.04). However, there were no changes in NPH insulin dose after two years follow-up (0.85 IU/kg). On the contrary, the dose of regular insulin administered on fasting conditions with normal glycemia increased from 0 to 0.21/kg after a year (p 0.0001) and to 0.69 after two years (non significant). Median HbA1C showed a significant reduction from 10 +/- 1.62% to 8.53 +/- 1.04% after a year (p 0.03) and to 8.72 +/- 0.81% after two years. BMI Z score increased from significantly from 0.7 +/- 0.9 to 1.06 +/- 1.15 after a year (p 0.03) with a further reduction without a significant difference from the basal value after two years. We found no significant differences in the frequency of hypoglycemia or other metabolic features. Our results show that intensive treatment of type 1 diab...

Durante la década pasada, se publicaron numerosos trabajos demostrando que el tratamiento intensivo de la diabetes tipo 1 puede prevenir y retrasar el desarrollo de las complicaciones microvasculares asociadas a la misma. Sin embargo en el grupo de niños y adolescentes se hallaron algunos problemas como el incremento de la frecuencia de los episodios de hipoglucemia y el excesivo aumento de peso. El propósito del presente estudio fue describir los resultados del tratamiento intensificado llevado a cabo durante 2 años en una población de niños y adolescentes argentinos con diabetes tipo 1. Fueron seleccionados 25 pacientes mayores de 10 años de edad con diabetes de más de 1 año de evolución. Todos ellos realizaron un programa de educación durante una semana de internación. El seguimiento posterior fue mensual durante los siguientes dos años. El esquema de tratamiento insulínico consistió en 4 a 5 controles preprandiales diarios, dos dosis de insulina NPH cubriendo requerimientos basales y cuatro dosis de insulina regular preprandial ajustadas de acuerdo al cálculode hidratos de carbono a ingerir, la actividad física y el valor de glucemia. La media de edad fue de 13.5años (r: 10-19 años). El tiempo medio transcurrido desde el diagnóstico hasta la intensificación del tratamientofue de 3.8 años ( r: 1.2 –9 años). La dosis media total de NPH disminuyó significativamente desde 0.9 U/kg en elinicio a 0.8 U/kg al año de seguimiento (p = 0.04), sin diferencias al segundo año de seguimiento (0.85 U/kg). Porel contrario, la dosis de insulina regular administrada en forma preprandial en normoglucemia aumentó de 0 a0.21 U/kg en el primer año (p 0.0001) y a 0.69 U/kg a los dos años (p NS). La media de HbA1C mostró unasignificativa reducción desde 10±1.62% a 8.53±1.04% en el primer año (p = 0.03) y 8.72± 0.81% a los dos años.El Z score de IMC aumentó significativamente de 0.7 ± 0.9 a 1.06 ± 1.15 luego de un año (p = 0.03) descendiendo a valores no...

Evaluación de un programa de educación de tratamiento intensivo en adolescentes con diabetes tipo 1. Seguimiento por dos años / Evaluation of an intensive treatment education program for type 1 diabetes in a group of adolescents. A two year follow up

During the past decade several reports were published showing that intensive treatment of type 1 diabetes can prevent and delay disease-related microvascular complications. However, several problems were reported in children and adolescents such as frequent hypoglycemic episodes and weight gain. The aim of this study was to describe the results of intensified treatment for type 1 diabetes in a group of Argentinean adolescents after a follow-up of two years. Twenty five adolescents with type 1 diabetes older than 10 years with at least one year from diagnosis were selected. All patients received a one-week teaching program during admission to our center. All patients were followed-up monthly during two years. Treatment schedule included 4-5 controls in fasting conditions, two doses of NPH insulin and four doses of regular insulin according to glycemia and the amount of calculated carbohydrate intake. Median age was 13.5 years (range 10 to 19 years). Mean time from diagnosis to inclusion in the study was 3.8 years (range 1.25 to 9 years). Mean total dose of NPH insulin decreased significantly when measured at the inclusion in the study (0.9 IU/kg) and after a year of follow-up 0.8 IU/kg (p 0.04). However, there were no changes in NPH insulin dose after two years follow-up (0.85 IU/kg). On the contrary, the dose of regular insulin administered on fasting conditions with normal glycemia increased from 0 to 0.21/kg after a year (p 0.0001) and to 0.69 after two years (non significant). Median HbA1C showed a significant reduction from 10 +/- 1.62% to 8.53 +/- 1.04% after a year (p 0.03) and to 8.72 +/- 0.81% after two years. BMI Z score increased from significantly from 0.7 +/- 0.9 to 1.06 +/- 1.15 after a year (p 0.03) with a further reduction without a significant difference from the basal value after two years. We found no significant differences in the frequency of hypoglycemia or other metabolic features. Our results show that intensive treatment of type 1 diab...(AU)

Durante la década pasada, se publicaron numerosos trabajos demostrando que el tratamiento intensivo de la diabetes tipo 1 puede prevenir y retrasar el desarrollo de las complicaciones microvasculares asociadas a la misma. Sin embargo en el grupo de niños y adolescentes se hallaron algunos problemas como el incremento de la frecuencia de los episodios de hipoglucemia y el excesivo aumento de peso. El propósito del presente estudio fue describir los resultados del tratamiento intensificado llevado a cabo durante 2 años en una población de niños y adolescentes argentinos con diabetes tipo 1. Fueron seleccionados 25 pacientes mayores de 10 años de edad con diabetes de más de 1 año de evolución. Todos ellos realizaron un programa de educación durante una semana de internación. El seguimiento posterior fue mensual durante los siguientes dos años. El esquema de tratamiento insulínico consistió en 4 a 5 controles preprandiales diarios, dos dosis de insulina NPH cubriendo requerimientos basales y cuatro dosis de insulina regular preprandial ajustadas de acuerdo al cálculode hidratos de carbono a ingerir, la actividad física y el valor de glucemia. La media de edad fue de 13.5años (r: 10-19 años). El tiempo medio transcurrido desde el diagnóstico hasta la intensificación del tratamientofue de 3.8 años ( r: 1.2 ¹9 años). La dosis media total de NPH disminuyó significativamente desde 0.9 U/kg en elinicio a 0.8 U/kg al año de seguimiento (p = 0.04), sin diferencias al segundo año de seguimiento (0.85 U/kg). Porel contrario, la dosis de insulina regular administrada en forma preprandial en normoglucemia aumentó de 0 a0.21 U/kg en el primer año (p 0.0001) y a 0.69 U/kg a los dos años (p NS). La media de HbA1C mostró unasignificativa reducción desde 10±1.62% a 8.53±1.04% en el primer año (p = 0.03) y 8.72± 0.81% a los dos años.El Z score de IMC aumentó significativamente de 0.7 ± 0.9 a 1.06 ± 1.15 luego de un año (p = 0.03) descendiendo a valores no...(AU)

Use of serum cholesterol/triglyceride ratio to discern for which individuals the Friedewald formula can be used confidently.

The values of low-density lipoprotein cholesterol obtained according to the Friedewald formula (Clin Chem 1972; 18:499-502), or by the De Long transformation (J Am Med Assoc 1986;256:2372-7), were compared with the values obtained when the individual cholesterol/triglyceride ratio of very-low-density lipoprotein was used for estimating the contribution of this lipoprotein to the total cholesterol. We found that these formulas gave the greatest errors for individuals with a low serum cholesterol/triglyceride ratio. We propose criteria for deciding when the numerically calculated value of low-density cholesterol is appropriate, and when it is not.