386 research outputs found
Feasibility of overnight closed-loop therapy in young children with type 1 diabetes aged 3-6â years: comparison between diluted and standard insulin strength.
OBJECTIVE: To assess feasibility of overnight closed-loop therapy in young children with type 1 diabetes and contrast closed loop using diluted versus standard insulin strength. RESEARCH DESIGN AND METHODS: Eleven children (male 6; age range 3.75-6.96â
years; glycated hemoglobin 60 (14) mmol/mol; body mass index SD score 1.0 (0.8); diabetes duration 2.2 (1.0) years, mean (SD); total daily dose 12.9 (10.6, 16.5) IU/day, median (IQR)) were studied at a clinical research facility on two occasions. In random order, participants received closed loop with diluted insulin aspart (CL_Dil; 20â
IU/mL) or closed loop with standard aspart (CL_Std; 100â
IU/mL) from 17:00 until 8:00 the following morning. Children consumed an evening meal at 17:00 (44 (12) gCHO) and an optional bedtime snack (6 (7) gCHO) identical on both occasions. Meal insulin boluses were calculated by standard pump bolus calculators. Basal rates on insulin pump were adjusted every 15â
min as directed by a model-predictive-control algorithm informed by a real-time glucose sensor values. RESULTS: Mean plasma glucose was 122 (24) mg/dL during CL_Dil vs 122 (23) mg/dL during CL_Std (p=0.993). The time spent in the target glucose range 70-145â
mg/dL was 83 (70, 100)% vs 72 (54, 81)% (p=0.328). Time above 145â
mg/dL was 13 (0, 27)% vs 19 (10, 45)% (p=0.477) and time spent below 70â
mg/dL was 0.0 (0.0, 1.4)% vs 1.4 (0.0, 11.6)% (p=0.161). One asymptomatic hypoglycemia below 63â
mg/dL occurred in one participant during CL_Dil versus six episodes in five participants during CL_Std (p=0.09). Glucose variability measured by CV of plasma glucose tended to be reduced during CL_Dil (20% (13, 31) vs 32% (24, 42), p=0.075). CONCLUSIONS: In this feasibility study, closed-loop therapy maintained good overnight glucose control with tendency towards reduced hypoglycemia and reduced glucose variability using diluted insulin. TRIAL REGISTRATION NUMBER: clinicaltrials.gov Identifier: NCT01557634.This work was funded by the Juvenile Diabetes Research Foundation (JDRF Grant Number: 22-2011-668) and supported by NIHR Cambridge Biomedical Research Centre.This is the final published version. It first appeared at http://drc.bmj.com/content/2/1/e000040.abstract
The Adolescent Cardio-Renal Intervention Trial (AdDIT): retinal vascular geometry and renal function in adolescents with type 1 diabetes
Aims/hypothesis We examined the hypothesis that elevation in urinary albumin creatinine ratio (ACR) in adolescents with type 1 diabetes is associated with abnormal retinal vascular geometry (RVG) phenotypes.
Methods A cross-sectional study at baseline of the relationship between ACR within the normoalbuminuric range and RVG in 963 adolescents aged 14.4 ± 1.6 years with type 1 diabetes (median duration 6.5 years) screened for participation in AdDIT. A validated algorithm was used to categorise log10 ACR into tertiles: upper tertile ACR was defined as âhigh-riskâ for future albuminuria and the lower two tertiles were deemed âlow-riskâ. RVG analysis, using a semi-automated computer program, determined retinal vascular calibres (standard and extended zones) and tortuosity. RVG measures were analysed continuously and categorically (in quintiles: Q1âQ5) for associations with log10 ACR and ACR risk groups.
Results Greater log10 ACR was associated with narrower vessel calibres and greater tortuosity. The high-risk group was more likely to have extended zone vessel calibres in the lowest quintile (arteriolar Q1 vs Q2âQ5: OR 1.67 [95% CI 1.17, 2.38] and venular OR 1.39 [0.98, 1.99]) and tortuosity in the highest quintile (Q5 vs Q1âQ4: arteriolar OR 2.05 [1.44, 2.92] and venular OR 2.38 [1.67, 3.40]). The effects of retinal vascular calibres and tortuosity were additive such that the participants with the narrowest and most tortuous vessels were more likely to be in the high-risk group (OR 3.32 [1.84, 5.96]). These effects were independent of duration, blood pressure, BMI and blood glucose control.
Conclusions/interpretation Higher ACR in adolescents is associated with narrower and more tortuous retinal vessels. Therefore, RVG phenotypes may serve to identify populations at high risk of diabetes complications during adolescence and well before onset of clinical diabetes complications.This work was supported by the National Health and Medical Research Council of Australia (NHMRC 632521), JDRF (08-2007-902), Diabetes UK (DUK PO NO 2177 BDA:RD06/003341) and the British Heart Foundation
Efectos de histéresis en la producción de un destilador
Con el objetivo de optimizar la producciĂłn de destilado se realizaron ensayos con un destilador de laboratorio sometido a calentamiento que reproduce el calentamiento solar de dĂa claro, cuyas cubiertas tienen una pendiente de 20Âș y se compararon con resultados previos obtenidos con una pendiente de 45Âș. Se observĂł que tanto el destilado promedio horario como el destilado total diario eran mayores en el caso de mayor pendiente. Se comprobĂł que la producciĂłn depende de la historia del funcionamiento del destilador, mostrando un efecto de histĂ©resis y se analizĂł la influencia estacional.With the aim of optimizing the distillate production essays were performed on a laboratory still with 20Âș inclination of the covers, under conditions similar to clear day solar heating. The results were compared with those obtained previously with a 45Âș slope in the covers. It was observed that the hourly mean distillate as well as the total daily distillate were higher in the case of higher slope and that the still production depends on the history of the functioning of the still, showing an hysteresis effect. The stational influence was analyzed.AsociaciĂłn Argentina de EnergĂas Renovables y Medio Ambiente (ASADES
Efectos de histéresis en la producción de un destilador
Con el objetivo de optimizar la producciĂłn de destilado se realizaron ensayos con un destilador de laboratorio sometido a calentamiento que reproduce el calentamiento solar de dĂa claro, cuyas cubiertas tienen una pendiente de 20Âș y se compararon con resultados previos obtenidos con una pendiente de 45Âș. Se observĂł que tanto el destilado promedio horario como el destilado total diario eran mayores en el caso de mayor pendiente. Se comprobĂł que la producciĂłn depende de la historia del funcionamiento del destilador, mostrando un efecto de histĂ©resis y se analizĂł la influencia estacional.With the aim of optimizing the distillate production essays were performed on a laboratory still with 20Âș inclination of the covers, under conditions similar to clear day solar heating. The results were compared with those obtained previously with a 45Âș slope in the covers. It was observed that the hourly mean distillate as well as the total daily distillate were higher in the case of higher slope and that the still production depends on the history of the functioning of the still, showing an hysteresis effect. The stational influence was analyzed.AsociaciĂłn Argentina de EnergĂas Renovables y Medio Ambiente (ASADES
Cardiac autonomic dysfunction is associated with high-risk albumin-to-creatinine ratio in young adolescents with type 1 diabetes in AdDIT (adolescent type 1 diabetes cardio-renal interventional trial).
OBJECTIVE: This study examined the association between cardiac autonomic dysfunction and high albumin-to-creatinine ratio (ACR) in adolescents with type 1 diabetes. RESEARCH DESIGN AND METHODS: Adolescents recruited as part of a multicenter screening study (n = 445, 49% female, aged 10-17 years, mean duration 6.9 years; mean HbA1c 8.4%, 68 mmol/mol) underwent a 10-min continuous electrocardiogram recording for heart rate variability analysis. Time-domain heart rate variability measures included baseline heart rate, SD of the R-R interval (SDNN), and root mean squared difference of successive R-R intervals (RMSSD). Spectral analysis included sympathetic (low-frequency) and parasympathetic (high-frequency) components. Standardized ACR were calculated from six early morning urine collections using an established algorithm, reflecting age, sex, and duration, and stratified into ACR tertiles, where the upper tertile reflects higher nephropathy risk. RESULTS: The upper-tertile ACR group had a faster heart rate (76 vs. 73 bpm; P < 0.01) and less heart rate variability (SDNN 68 vs. 76 ms, P = 0.02; RMSSD 63 vs. 71 ms, P = 0.04). HbA1c was 8.5% (69 mmol/mmol) in the upper tertile vs. 8.3% (67 mmol/mol) in the lower tertiles (P = 0.07). In multivariable analysis, upper-tertile ACR was associated with faster heart rate (ÎČ = 2.5, 95% CI 0.2-4.8, P = 0.03) and lower RMSSD (ÎČ = -9.5, 95% CI -18.2 to -0.8, P = 0.03), independent of age and HbA1c. CONCLUSIONS: Adolescents at potentially higher risk for nephropathy show an adverse cardiac autonomic profile, indicating sympathetic overdrive, compared with the lower-risk group. Longitudinal follow-up of this cohort will further characterize the relationship between autonomic and renal dysfunction and the effect of interventions in this population.National Health and Medical Research Council, Australia (NHMRC) 632521, Australasian Paediatric Endocrine Group (APEG), Juvenile Diabetes Research Foundation, British Heart Foundation, Diabetes UK.This is the accepted manuscript. The final version is available at http://care.diabetesjournals.org/content/early/2015/01/01/dc14-1848
Gravity modes as a way to distinguish between hydrogen- and helium-burning red giant stars
Red giants are evolved stars that have exhausted the supply of hydrogen in
their cores and instead burn hydrogen in a surrounding shell. Once a red giant
is sufficiently evolved, the helium in the core also undergoes fusion.
Outstanding issues in our understanding of red giants include uncertainties in
the amount of mass lost at the surface before helium ignition and the amount of
internal mixing from rotation and other processes. Progress is hampered by our
inability to distinguish between red giants burning helium in the core and
those still only burning hydrogen in a shell. Asteroseismology offers a way
forward, being a powerful tool for probing the internal structures of stars
using their natural oscillation frequencies. Here we report observations of
gravity-mode period spacings in red giants that permit a distinction between
evolutionary stages to be made. We use high-precision photometry obtained with
the Kepler spacecraft over more than a year to measure oscillations in several
hundred red giants. We find many stars whose dipole modes show sequences with
approximately regular period spacings. These stars fall into two clear groups,
allowing us to distinguish unambiguously between hydrogen-shell-burning stars
(period spacing mostly about 50 seconds) and those that are also burning helium
(period spacing about 100 to 300 seconds).Comment: to appear as a Letter to Natur
Operations of and Future Plans for the Pierre Auger Observatory
Technical reports on operations and features of the Pierre Auger Observatory,
including ongoing and planned enhancements and the status of the future
northern hemisphere portion of the Observatory. Contributions to the 31st
International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200
Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory
The Pierre Auger Collaboration has reported evidence for anisotropy in the
distribution of arrival directions of the cosmic rays with energies
eV. These show a correlation with the distribution
of nearby extragalactic objects, including an apparent excess around the
direction of Centaurus A. If the particles responsible for these excesses at
are heavy nuclei with charge , the proton component of the
sources should lead to excesses in the same regions at energies . We here
report the lack of anisotropies in these directions at energies above
(for illustrative values of ). If the anisotropies
above are due to nuclei with charge , and under reasonable
assumptions about the acceleration process, these observations imply stringent
constraints on the allowed proton fraction at the lower energies
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