Performance of a GridPix detector based on the Timepix3 chip Ligtenberg, C.; Heijhoff, K.; Bilevych, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
11/2018, Letnik:
908
Journal Article
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A GridPix readout for a TPC based on the Timepix3 chip is developed for future applications at a linear collider. The GridPix detector consists of a gaseous drift volume read out by a single Timepix3 ...chip with an integrated amplification grid. Its performance is studied in a test beam with 2.5 GeV electrons. The GridPix detector detects single ionization electrons with high efficiency. The Timepix3 chip allowed for high sample rates and time walk corrections. Diffusion is found to be the dominating error on the track position measurement both in the pixel plane and in the drift direction, and systematic distortions in the pixel plane are below 10 μm. Using a truncated sum, an energy loss (dE/dx) resolution of 4.1% is found for an effective track length of 1 m.
Sodium-glucose cotransporter 2 (SGLT2) inhibitors include a relatively new class of glucose-lowering drugs that reduce plasma glucose concentrations by inhibiting proximal tubular reabsorption of ...glucose in the kidney, while increasing its excretion in urine. Recent large randomised controlled trials have demonstrated that many of these agents reduce the occurrence of major adverse cardiovascular events, hospitalisation for heart failure, cardiovascular death and/or chronic kidney disease progression in patients with and without type 2 diabetes mellitus (DM2). Given their unique insulin-independent mode of action and favourable efficacy and adverse-event profile, SGLT2 inhibitors are promising and they offer an interesting therapeutic approach for the cardiologist to incorporate into routine practice. However, despite accumulating data supporting this class of therapy, cardiologists infrequently prescribe SGLT2 inhibitors, potentially due to a lack of familiarity with their use and the reticence to change DM medication. Here, we provide an up-to-date practical guide highlighting important elements of treatment initiation based on real-world evidence and expert opinion. We describe how to change DM medication, including insulin dosing when appropriate, and how to anticipate any adverse events based on real-world experience in patients with DM2 in the Meander Medical Centre in Amersfoort, the Netherlands. This includes a simple algorithm showing how to initiate SGLT2 inhibitor treatment safely, while considering the consequence of the glucosuric effects of these inhibitors for the individual patient.
New results from GridPix Detectors Bilevych, Y; Desch, K; Fransen, J-P ...
Journal of physics. Conference series,
04/2020, Letnik:
1498, Številka:
1
Journal Article
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GridPix structures combine the high resolution of a pixel readout chip with a Micromegas as gas amplification stage. This detector has shown excellent performance before with the Timepix ASIC, but ...has been improved by using the successor ASIC, the Timepix3. This new version of the GridPix detectors has been used in test beams at the ELSA accelerator at Bonn, where 2.5 GeV electrons are available for tracking studies. It could be demonstrated that the spatial resolution in both transverse and longitudinal direction follows the diffusion function. Structures made of four GridPixes have been designed and constructed to cover larger areas. Also these devices called quads have been successfully tested with the electron beam giving similarly good results as the single GridPix detector.
1. The specific role of physical activity in the treatment of type 2 diabetes is still subject to discussion. A randomized prospective study was performed, investigating both the influence of ...physical training on metabolic control and the feasibility of physical training in the elderly. 2. A total of 58 patients (mean age: 62 +/- 5 years; range: 55-75 years) with type 2 diabetes were randomized to either a physical training or a control programme. The training programme consisted of three sessions a week, aiming at 60-80% of the maximal oxygen uptake (VO2max). The 12 week supervised period was followed by a 14 week non-supervised one. The control group followed an educational programme. VO2max was assessed during exercise on a cycle ergometer. Glycosylated haemoglobin (HbA1c) was used as a measure for glucose control, and an insulin tolerance test was performed to test insulin sensitivity. Multivariate analysis of variance, with repeated measures design, was used to test differences between groups. 3. Fifty-one patients completed the study. VO2max was higher in the training group than in the control group both after 6 weeks (P < or = 0.01 between groups) and after 26 weeks training group: 1796 +/- 419 ml/min (prestudy), 1880 +/- 458 ml/min (6 weeks), 1786 +/- 591 ml/min (26 weeks); control group: 1859 +/- 455 ml/min (prestudy), 1742 +/- 467 ml/min (6 weeks), 1629 +/- 504 ml/min (26 weeks). Blood glucose control and insulin sensitivity did not change during the study. Levels of total triacylglycerols, very-low-density lipoprotein-triacylglycerols and apolipoprotein B were significantly lower after 6 weeks (P < or = 0.01, P < or = 0.05, P < or = 0.05 between groups respectively), and so was the level of total cholesterol after 12 weeks of training (P < or = 0.05 between groups). 4. Physical training in obese type 2 diabetic patients over 55 years of age does not change glycaemic control or insulin sensitivity in the short-term. Regular physical activity may lower triacylglycerol and cholesterol levels in this group of patients. 5. Finally, physical training in motivated elderly type 2 diabetic patients without major cardiovascular or musculoskeletal disorders is feasible, but only under supervision.
On the properties of a negative-ion TPC prototype with GridPix readout Ligtenberg, C.; van Beuzekom, M.; Bilevych, Y. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
10/2021, Letnik:
1014
Journal Article
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The performance of a GridPix detector to read out a negative ion TPC was studied using a module with four GridPix chips that are based on the Timepix3 pixelated readout ASIC. The quad module ...dimensions are 39.6mm×28.38mm, and the maximum drift distance is 40mm. The TPC is operated using a 93.6/5.0/1.4 gas mixture (by volume) of Ar/iC4H10/CS2 with a small amount of oxygen and water vapour at a pressure of 1030mbar and a temperature of 297K. Tracks were produced by a pulsed N2 laser. The GridPix chips are sensitive to single drift ions, and allow for the determination of the drift distance using the velocities of the different ion species. The 1.56ns time resolution of the Timepix3 chips allows for a precise determination of the drift properties in the longitudinal direction. The measured mobility of majority ion charge carriers is (1.391±0003) cm2/V/s. Using the high granularity pixel readout, the transverse and longitudinal diffusion coefficients were measured to correspond to an effective thermal diffusion temperature of 314 K and 384 K respectively. For 429 detected ions, the precision on the absolute drift distance is expected to be 1.33mm for a mean drift distance of 20mm.
Performance of the GridPix detector quad Ligtenberg, C.; Bilevych, Y.; Desch, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
03/2020, Letnik:
956
Journal Article
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Odprti dostop
A gaseous pixel readout module with four GridPix chips, called the quad, has been developed as a building block for a large time projection chamber readout plane. The quad module has dimensions ...39.6mm×28.38mm and an active surface coverage of 68.9%. The GridPix chip consists of a Timepix3 chip with integrated amplification grid and have a high efficiency to detect single ionization electrons, which enable to make a precise track position measurement. A quad module was installed in a small time projection chamber and measurements of 2.5GeV electrons were performed at the ELSA accelerator in Bonn, where a silicon telescope was used to provide a reference track. The error on the track position measurement, both in the pixel plane and drift direction, is dominated by diffusion. The quad was designed to have minimum electrical field inhomogeneities and distortions, achieving systematics of better than 13µm in the pixel plane. The resolution of the setup is 41µm, where the total systematic error of the quad detector is 24µm.
The gaseous QUAD pixel detector Ligtenberg, C.; Bilevych, Y.; Desch, K. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2020, Letnik:
958
Journal Article
Recenzirano
A gaseous pixel detector has been developed based on four Timepix3 chips, called a quad, that can serve as a building block for e.g. a large Time Projection Chamber readout plane. The quad was ...designed to have minimum electrical field inhomogeneities and distortions, achieving a tracking precision in the pixel plane with systematics of better than 20 μm. Due to the high efficiency to detect the ionization electrons a precise measurement of the energy loss dE/dx can be performed. In this article we present details about the construction of the quad and the results from a recent test beam experiment performed at the ELSA electron beam in Bonn where a silicon telescope was used to provide accurate tracking to study the quad detector.
A 69-year-old woman developed Cushing's syndrome after long-term use of Sinatren, an Indonesian over the-counter drug, which was pharmacologically analysed three times before the correct content was ...discovered. After discontinuation she developed adrenal insufficiency, for which she needed substitution of steroids. Physicians should be aware of the presence of corticosteroids in over-the-counter products, that are not mentioned on the instruction leaflet.
The main purpose of the present study was to assess the relation between long-term physical activity and glycemic control in patients with type 1 diabetes mellitus.
Medical data and blood samples for ...the determination of glycosylated hemoglobin (glyHb) were collected in 221 consecutive type 1 diabetes patients between 18 and 45 years of age without late complications. A self-report questionnaire was used to determine the degree of physical activity. Correlation coefficients and analysis of variance were used for statistical analyses.
No correlation was observed between the different levels of physical activity and glycemic control. Females showed a significantly higher total physical activity index than males (p = 0.004), mostly due to the leisure time activity index. More active patients used a lower amount of insulin (r = -0.20, p = 0.002) than less active patients.
Glycemic control was not found to be associated with long-term physical activity in type 1 diabetes patients. Physical activity did not negatively affect long-term glycemic control.
STUDY QUESTION
Is type 1 diabetes a determinant of advanced ovarian ageing, resulting in an early age at natural menopause?
SUMMARY ANSWER
No clear evidence was provided that type 1 diabetes is a ...determinant of accelerated ovarian ageing resulting in an early menopause.
WHAT IS KNOWN ALREADY
The association between type 1 diabetes and early menopause has been examined previously with inconsistent results.
STUDY DESIGN, SIZE, DURATION
A cross-sectional study was performed in 140 post-menopausal women with, and 5426 post-menopausal women without, diabetes.
PARTICIPANTS/MATERIALS, SETTING, METHODS
Both women with and without diabetes had experienced natural menopause. Study participants filled out a standardized questionnaire including report of their age at last menstrual period. Differences in menopausal age were analysed using linear regression analyses, with adjustment for possible confounders.
MAIN RESULTS AND THE ROLE OF CHANCE
Mean age at natural menopause was 49.8 ± 4.7 years in women with type 1 diabetes and 49.8 ± 4.1 in women without diabetes. Linear regression analyses showed that type 1 diabetes was not associated with an earlier menopause compared with the reference group without diabetes, after adjustment for age, smoking history and parity (difference in age at menopause between women with type 1 diabetes and reference group 0.34 years, 95% confidence interval −0.34, 1.01).
LIMITATIONS, REASON FOR CAUTION
Age at menopause was self-reported and assessed retrospectively. We had no information regarding microvascular complications therefore a possible association between vascular health and menopausal age could not be investigated.
WIDER IMPLICATIONS OF THE FINDINGS
It has been hypothesized that the possible mechanism behind an accelerated ovarian ageing process in type 1 diabetes is prolonged poor glycaemic control and subsequent effects on vascular health. The improved glycaemic control during the last decades may have prevented vascular damage from occurring to an extent that would affect organ function. Nevertheless, the present findings are reassuring for reproductive health prospects in women with type 1 diabetes.
STUDY FUNDING/ COMPETING INTEREST(S)
The EPIC-NL study was funded by the ‘Europe against Cancer’ Program of the European Commission (SANCO), the Dutch Ministry of Public Health, Welfare and Sports, the Dutch Cancer Society, the Netherlands Organisation for Health research and Development (ZonMW), and World Cancer Research Fund (WCRF). F.J.M.B. has received fees and grant support from the following companies: Ferring, Gedeon Richter, Merck Serono, Medical Specialties Distributors, and Roche.
TRIAL REGISTRATION NUMBER
Not applicable.
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