Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 5
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

Background: The older population is very heterogeneous with regard to the co-morbidity and the physical reserve. This can result in unacceptably high postoperative complications rates. Th erefore, the aim of the study was to review the literature regarding the outcomes of older patients treated for pancreatic cancer, including the usage of minimal invasive techniques.

Methodology: A review of the literature was carried out including studies on pancreatic cancer in older patients published between 2011 and 2016.

Results: Seventeen retrospective studies were included. The total number of patients was 9981 with the age range of 65 years and more. Studies on surgical treatment alone (1.4%), neoadjuvant/adjuvant treatment with or without surgery (89.4%) and palliative therapy (9.2%) were assessed separately. Appropriate comparison was diffi cult due to the retrospective character and heterogeneity of the study population. Mortality was low, yet there was a great diff erence in morbidity ranging from some percent to even 100% of the study population. Long-term results were poor.

Conclusions: The functional status, not the chronological age alone, is the factor limiting therapeutic options in older patients with pancreatic cancer.

Go to article

Authors and Affiliations

Mateusz Gajda
Jakub Kenig
Download PDF Download RIS Download Bibtex

Abstract

The main purpose of this work is to provide an extensive, simulation-based comparison of robustness of PID and MPC algorithms in control of blood glucose levels in patients with type 1 diabetes and thus answer the question of their safety. Cohort testing, with 1000 simulated, randomized patients allowed to analyze specific control quality indicators, such as number of hypoglycemic events, and length of hypo- and hyperglycemia periods. Results show that both algorithms provide a reasonable safety level, taking into account natural changes of patients’ physiological parameters. At the same time, we point out drawbacks of each solution, as well as general problems arising in close-loop control of blood glucose level.
Go to article

Authors and Affiliations

Artur Wyciślok
1
ORCID: ORCID
Jarosław Śmieja
1

  1. Department of Biology and Systems Engineering, Silesian University of Technology, Gliwice, Poland
Download PDF Download RIS Download Bibtex

Abstract

The demand of energy and the search for alternative energy sources are the reason why scientists are interested in starch hydrolysis. The aim of the work was to experimental study of the hydrolysis of starch by α–amylase from porcine pancreas with α–amylase deactivation. Based on the experiments data, the parameters of starch hydrolysis by α– amylase with deactivation of enzyme was estimated. A mathematical model of temperature impact on the activity of α–amylase from porcine pancreas was used. It has been estimated that the activation energy Ea and the deactivation energy Ed were equal to 66 ± 4 kJ/mol and 161 ± 12 kJ/mol, respectively. Additionally, specific constant of starch hydrolysis k 0 and specific constant of α–amylase deactivation k d0 were calculated. The optimum temperature Topt equal to 318 ± 0.5 K was obtained from mathematical model. The obtained values of Ea, Ed, k 0 and k d0 parameters were used to the model starch hydrolysis by α–amylase from porcine pancreas at 310 K and 333 K.
Go to article

Authors and Affiliations

Justyna Miłek
1
ORCID: ORCID
Ireneusz Grubecki
2
ORCID: ORCID
Wirginia Tomczak
1
ORCID: ORCID

  1. Bydgoszcz University of Science and Technology, Department of Chemical and Biochemical Engineering, Faculty of Chemical Technology and Engineering, Semianryjna 3, 85-326 Bydgoszcz, Poland
  2. Cracow University of Technology, Faculty of Chemical Engineering and Technology, Warszawska 24, 31-155 Cracow, Poland
Download PDF Download RIS Download Bibtex

Abstract

The primary objective of this paper is the custom design of an effective, yet relatively easyto- implement, predictive control algorithm to maintain normoglycemia in patients with type 1 diabetes. The proposed patient-tailorable empirical model featuring the separated feedback dynamics to model the effect of insulin administration and carbohydrate intake was proven to be suitable for the synthesis of a high-performance predictive control algorithm for artificial pancreas.Within the introduced linear model predictive control law, the constraints were applied to the manipulated variable in order to reflect the technical limitations of insulin pumps and the typical nonnegative nature of the insulin administration. Similarly, inequalities constraints for the controlled variable were also assumed while anticipating suppression of hypoglycemia states during the automated insulin treatment. However, the problem of control infeasibility has emerged, especially if one uses too tight constraints of the manipulated and the controlled variable concurrently. To this end, exploiting the Farkas lemma, it was possible to formulate the helper linear programming problem based on the solution of which this infeasibility could be identified and the optimality of the control could be restored by adapting the constraints. This adaptation of constraints is asymmetrical, thus one can force to fully avoid hypoglycemia at the expense of mild hyperglycemia. Finally, a series of comprehensive in-silico experiments were carried out to validate the presented control algorithm and the proposed improvements. These simulations also addressed the control robustness in terms of the intersubject variability and the meal announcements uncertainty.
Go to article

Authors and Affiliations

Martin Dodek
1
Eva Miklovicová
1

  1. Institute of Robotics and Cybernetics, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology in Bratislava, Slovakia
Download PDF Download RIS Download Bibtex

Abstract

Previous morphological studies of mammalian pancreatic islets have been performed mainly in domestic and laboratory animals. Therefore, the present immunohistochemical investigation was conducted in a wild species, the European bison, using antibodies against glucagon-like peptide-1 (GLP1), glucagon, insulin and somatostatin. Morphological analyses revealed that the mean area of the endocrine pancreas constituted 2.1±0.1% of the whole area of the pancreas, while the mean area of a single pancreatic islet was 13301.5±686.5 µm2. Glucagon-immunoreac- tive cells accounted for 22.4±1.1% and occupied 19.4±0.4% of the average islet area. As many as 14.3±1.4% of pancreatic islet cells were shown to express GLP1, which constituted 12.6±0.8% of the mean area of the islet. Insulin expression was confirmed in 67.6±0.7% of pancreatic islet cells, which represented 62.3±4.9% of the mean total area of the pancreatic islet. As many as 8.5±1.3% of cells stained for somatostatin. The somatostatin-immunoreactive cell area was 4.9±0.3% of the mean pancreatic islet area. In summary, we have determined in detail for the first time the morphometry and islet composition of the European bison pancreas. The distri- bution patterns of immunoreactivities to the substances studied in the European bison show many similarities to those described in other ruminant species.

Go to article

Authors and Affiliations

S. Mozel
S. Szymańczyk
M. Krzysiak
I. Puzio
A. Zacharko-Siembida
M.B. Arciszewski

This page uses 'cookies'. Learn more