40 research outputs found
Effect of high-salt diet on blood pressure and body fluid composition in patients with type 1 diabetes: randomized controlled intervention trial
INTRODUCTION: Patients with type 1 diabetes are susceptible to hypertension, possibly resulting from increased salt sensitivity and accompanied changes in body fluid composition. We examined the effect of a high-salt diet (HSD) in type 1 diabetes on hemodynamics, including blood pressure (BP) and body fluid composition. RESEARCH DESIGN AND METHODS: We studied eight male patients with type 1 diabetes and 12 matched healthy controls with normal BP, body mass index, and renal function. All subjects adhered to a low-salt diet and HSD for eight days in randomized order. On day 8 of each diet, extracellular fluid volume (ECFV) and plasma volume were calculated with the use of iohexol and 125I-albumin distribution. Hemodynamic measurements included BP, cardiac output (CO), and systemic vascular resistance. RESULTS: After HSD, patients with type 1 diabetes showed a BP increase (mean arterial pressure: 85 (5) mm Hg vs 80 (3) mm Hg; p<0.05), while BP in controls did not rise (78 (5) mm Hg vs 78 (5) mm Hg). Plasma volume increased after HSD in patients with type 1 diabetes (p<0.05) and not in controls (p=0.23). There was no significant difference in ECFV between diets, while HSD significantly increased CO, heart rate (HR) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in type 1 diabetes but not in controls. There were no significant differences in systemic vascular resistance, although there was a trend towards an HSD-induced decrease in controls (p=0.09). CONCLUSIONS: In the present study, patients with type 1 diabetes show a salt-sensitive BP rise to HSD, which is accompanied by significant increases in plasma volume, CO, HR, and NT-proBNP. Underlying mechanisms for these responses need further research in order to unravel the increased susceptibility to hypertension and cardiovascular disease in diabetes. TRIAL REGISTRATION NUMBERS: NTR4095 and NTR4788
Towards understanding and eliminating defects in additively manufactured CubeSat mirrors
Fabricating mirrors using additive manufacturing (AM; 3D printing) is a promising yet under-researched production route. There are several issues that need to be better understood before AM can be fully adopted to fabricate mirror substrates. A significant obstacle to AM adoption is the presence of porosity and the influence that has on the resultant optical proprieties. Several batches of high-silicon aluminium (AlSi10Mg) samples were created to investigate the relationships laser parameters, laser paths and build orientations have with the porosity. The results showed that eliminating defects relies on a complex interaction of the process parameters and material properties, with the residual heating from the laser proving to be a significant factor. In addition, the use of a hot isostatic press is investigated and some full prototypes of the Cassegrain CubeSat were produced
Evaluation of factors affecting nuclear medicine examinations
This dissertation focuses on the significant role of research techniques within nuclear medicine, such as PET and SPECT, in understanding physiological processes in the human body. These techniques are of great value for the diagnosis, staging, treatment, and monitoring of diseases. The research focuses on factors that influence the accuracy and reliability of these methods, including patient characteristics, medication use, and analytical methods.The first part focuses on patient-related factors in breast cancer patients. Age, BMI, and tumour palpability are predictive factors for visualizing the sentinel lymph node. The second part investigates the influence of medication, such as the binding of radiotracers to dopamine transporters and somatostatin receptors. Results suggest that medication use does not always affect imaging and sometimes even increases tracer uptake. The third part emphasizes the importance of analytical methods, particularly in measuring the transcapillary escape rate of albumin. The research suggests that timing of blood sampling and the use of specific analytical models can influence results.Overall, the dissertation provides valuable insight into factors that influence various research techniques within nuclear medicine. It underscores the importance of optimizing procedures for accurate and reliable diagnosis and treatment, thereby contributing to the advancement of this field in modern medicine