Broad-Band, Intensity-Dependent Absorption In Tetravalent Chromium-Doped Crystals

Cr4+ -doped Y2SiO5 and Ca2Al2SiO7 have been investigated as broadband, solid state saturable absorbers. Saturation properties in the near infrared as well as a demonstration of tunable, passive Q switching of a flash-lamp pumped Cr:LiSAF laser are discussed

Crecimiento anormal de grano en hielo

Como parte de Ias investigaciones de crecimiento de grano en hielo, se realizaron experiencias de recocidos isotérmicos en muestras de hielo dopado con 10 -2 M de HF y NH4OH. Las temperaturas de recocido estudiadas son -2 , -6 y -10 ºC y Ios tiempos varian entre 24 hs y 3 meses. Las muestras estudiadas tienen una zona externa caracterizada por cristales elongados en Ia dirección radial y una zona central de cristales equiaxiados. Los resultados obtenidos muestran que Ia cinética de crecimiento de Ios granos pertenecientes a Ia zona externa es similar a Ia observada anteriormente, en muestras de hielo dopado cαn Ias impurezas que se encuentran naturalmente en Ia atmósfera. Los cristales de Ia zona central, sin embargo, presentan una velocidad de crecimiento un orden de magnitud mayor. El diferente comportamiento observado se atribuye a Ia diferencia de forma de Ios cristales. Se discute Ia necesidad de tener en cuenta Ios presentes resultados cuando se analiza Ia estructura cristalina de Ios granizos.Isothermic annealing exρεriments are made uεing HF 10-2 M and NH4OH 10-2 M frozen isolation as a part of the researchs on grain growth in ice. The annealing temperatures are -2, -6 and -10 ºC and the times range from 24 hs to 3 months. The samples háve an equiaxed crystal zones surrounded by an outer ring of elongated crystals. The grain growth kinetic in tne outer zone is similar to that already observed in ice samples doped with impurities frecuently appearing in the atmosphere. The central crystals, in contrast, have a growth rate 10 times higher. This is attributed to the different crystal shape. The Importance of the ρresent results on crystal structure analysis of hailstones is dicussed.Asociación Argentina de Geofísicos y Geodesta

Estudio de la etapa inicial del proceso de acreción

Diversos autores discutieron el proceso de congelación de gotas de agua, que cho can sobre un sustrato a velocidad terminal de caída libre. En esas condiciones no se manifiesta la orientación preferencial típica de los granizos y acreciones formados en crecimiento seco. En consecuencia, se decidió realizar experiencias con velocidades de impacto de 10 ms-l, gotas de 50 a 200 m, sustratos básales y prismáticos, temperaturas del aire y del sustrato entre -2°C y -15°C. Los resultados indican que la estructura de las acreciones depende fundamentalmente de la velocidad de impacto de las gotas. Se discuten los mecanismos que determinan el predominio de uno u otro tipo de proceso. Los resultados se aplican a la interpretación de la estructura de acrecí enes, en especial la de embriones de granizos.Many authors have discussed the freezing process of water drops, which fall down on the substrate at free fall terminal velocity. Under such conditions , the typical preferential orientation of the hailstones and accretions formed in a dry growth is not shown. Thus, it was decided to experiment with impact velocities of 10 ms~l, drops frcm 50m to 200m, basal and prismatic substrates, air and subís trate temperatures between -2°C and -15°C. The results indicate that the accretion structure fundamentally depends on the impact velocity of the waterdrops. It is being discussed the mechanisms which determine the predominance of one of the two types of processes over the other. The results apply to the interpretation of the structure of the accretions, especially that of hail embryos.Asociación Argentina de Geofísicos y Geodesta

Locomotor adaptability in persons with unilateral transtibial amputation

Background Locomotor adaptation enables walkers to modify strategies when faced with challenging walking conditions. While a variety of neurological injuries can impair locomotor adaptability, the effect of a lower extremity amputation on adaptability is poorly understood. Objective Determine if locomotor adaptability is impaired in persons with unilateral transtibial amputation (TTA). Methods The locomotor adaptability of 10 persons with a TTA and 8 persons without an amputation was tested while walking on a split-belt treadmill with the parallel belts running at the same (tied) or different (split) speeds. In the split condition, participants walked for 15 minutes with the respective belts moving at 0.5 m/s and 1.5 m/s. Temporal spatial symmetry measures were used to evaluate reactive accommodations to the perturbation, and the adaptive/de-adaptive response. Results Persons with TTA and the reference group of persons without amputation both demonstrated highly symmetric walking at baseline. During the split adaptation and tied post-adaptation walking both groups responded with the expected reactive accommodations. Likewise, adaptive and de-adaptive responses were observed. The magnitude and rate of change in the adaptive and de-adaptive responses were similar for persons with TTA and those without an amputation. Furthermore, adaptability was no different based on belt assignment for the prosthetic limb during split adaptation walking. Conclusions Reactive changes and locomotor adaptation in response to a challenging and novel walking condition were similar in persons with TTA to those without an amputation. Results suggest persons with TTA have the capacity to modify locomotor strategies to meet the demands of most walking conditions despite challenges imposed by an amputation and use of a prosthetic limb

An interdisciplinary intervention for older Taiwanese patients after surgery for hip fracture improves health-related quality of life

Abstract Background The effects of intervention programs on health-related quality of life (HRQOL) of patients with hip fracture have not been well studied. We hypothesized that older patients with hip fracture who received our interdisciplinary intervention program would have better HRQOL than those who did not. Methods A randomized experimental design was used. Older patients with hip fracture (N = 162), 60 to 98 years old, from a medical center in northern Taiwan were randomly assigned to an experimental (n = 80) or control (n = 82) group. HRQOL was measured by the SF-36 Taiwan version at 1, 3, 6, and 12 months after discharge. Results The experimental group had significantly better overall outcomes in bodily pain (β = 9.38, p = 0.002), vitality (β = 9.40, p < 0.001), mental health (β = 8.16, p = 0.004), physical function (β = 16.01, p < 0.001), and role physical (β = 22.66, p < 0.001) than the control group at any time point during the first year after discharge. Physical-related health outcomes (physical functioning, role physical, and vitality) had larger treatment effects than emotional/mental- and social functioning-related health outcomes. Conclusions This interdisciplinary intervention program may improve health outcomes of elders with hip fracture. Our results may provide a reference for health care providers in countries using similar programs with Chinese/Taiwanese immigrant populations. Trial registration NCT01052636http://deepblue.lib.umich.edu/bitstream/2027.42/78259/1/1471-2474-11-225.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78259/2/1471-2474-11-225.pdfPeer Reviewe

The Use of Preoperative Epoetin-α in Revision Hip Arthroplasty

PURPOSE: To evaluate the efficacy of preoperative epoetin-α on the revision hip arthroplasty patient. We hypothesized that epoetin-α will reduce blood transfusion. A pertinent review of the literature is provided. METHODS: Forty-six patients were retrospectively reviewed. Sixteen patients received epoetin-α. Patients were case matched by age, preoperative hemoglobin, surgery, gender, and BMI. The clinical triggers for blood transfusion during or after the procedure were determined based on peri- and postoperative hemoglobin levels, ASA score, and/or clinical symptoms consistent with anemia. Blood salvage was not used. RESULTS: Blood transfusion and length of stay were decreased in the epoetin-α group. Hemoglobin in the intervention group increased from 12.0 to 14.5, preoperatively. Patients who received epoetin-α were 0.78 (RR=0.225) times as likely to receive a transfusion. Number Needed to Treat (NNT) to avoid one allogeneic transfusion was 1.84. Age, Gender, BMI, ASA, total and hidden blood loss, preoperative Iron supplements, preop Hct, preop PLT, PT, PTT, and INR were similar. One (6.0%) patient developed an uncomplicated deep venous thrombosis in the intervention group. CONCLUSIONS: The mildly anemic revision hip arthroplasty patient is at increased risk for transfusion. Epoetin-α increased preoperative hemoglobin counts and reduced transfusions in this study; it also decreased patient length of hospital stay likely allowing for an earlier readiness to resume normal activities and/or meet short-term milestones. A randomized study to evaluate the direct and indirect costs of such a treatment methodology in the mildly anemic revision patient may be warranted