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Andrzej Jopkiewicz, Jacek Gawron and Stanisław Nowak

Abstract

Purpose. The aim of the study was to check whether and to what extent leisure-time physical activity and commuting activity constitute a factor differentiating physical fitness in a selected group of females and males aged 20-59 years. Methods. The study was performed in the Świętokrzyskie region of Poland in the spring of 2010. The sample included 1032 adults (517 females and 515 males) employed and at the same time completing extramural education or attending vocational improvement programs. Four age groups were delineated (20-29, 30-39, 40-49 and 50-59). A self-report questionnaire assessed physical activity level whereas physical fitness was determined by tests assessing handgrip strength, upper (dynamic) and lower (explosive) extremity strength, agility, hand movement speed, and endurance. Results. A significant relationship was found between leisure-time physical activity and all the performance-based measures in both females and males. With regard to commuting activity, statistically significant relationships were observed only in the females with regard to handgrip strength, lower extremity strength and endurance. Conclusions. A significant positive relationship between leisure-time physical activity and physical fitness was demonstrated in both females and males aged 20-59 years while commuting activity should significant correlations only in females.

Open access

Iwona Adamiec-Wójcik, Andrzej Nowak and Stanisław Wojciech

Abstract

Dry electrostatic precipitators (ESPs) are widely used for purification of exhaust gases in industrial applications. Maintenance of their high efficiency depends primarily on periodical cleaning of the collecting electrodes (CEs). Dust removal (regeneration of CEs) is realized by inducing periodical vibrations of the electrodes. The paper presents results of vibration modelling of a system of CEs; the results were obtained by means of the finite element method, the hybrid finite element method, the finite strip method and a model formulated using Abaqus. Numerical results are compared with those obtained from experimental measurements. Conclusions concerning numerical effectiveness and exactness of the methods are formulated and reasons for differences are discussed.

Open access

Iwona Adamiec-Wójcik, Andrzej Nowak and Stanisław Wojciech

Abstract

The rigid finite element method (RFEM) has been used mainly for modelling systems with beam-like links. This paper deals with modelling of a single set of electrodes consisting of an upper beam with electrodes, which are shells with complicated shapes, and an anvil beam. Discretisation of the whole system, both the beams and the electrodes, is carried out by means of the rigid finite element method. The results of calculations concerned with free vibrations of the plates are compared with those obtained from a commercial package of the finite element method (FEM), while forced vibrations of the set of electrodes are compared with those obtained by means of the hybrid finite element method (HFEM) and experimental measurements obtained on a special test stand.

Open access

Sławomir Mrowiec, Magdalena Dobija, Joanna Nalewajka-Kołodziejczak, Anna Kasicka-Jonderko, Krzysztof Jonderko, Stanisław Nowak and Paweł Lampe

Gastric Emptying in Esophageal Substitutes

For patients undergoing esophagectomy, the stomach is the organ that is most commonly used to restore continuity in the gastrointestinal tract. As a consequence of changes in stomach shape and location, patients in the postoperative period usually experience disturbed motility of the upper gastrointestinal tract of variable intensity.

The aim of the study was to assess the motility of esophageal substitutes and the emptying rate of a narrowed stomach (in particular its prepyloric portion) using scintigraphy in patients undergoing esophageal resection compared to those in healthy controls.

Material and methods. Between 2000 and 2006, 297 patients (105 women, 192 men) underwent surgical treatment for esophageal cancer in the Clinic of Gastrointestinal Surgery. Ten patients (average age 59; range 54 to 67 years) who underwent an attempted curative esophageal resection were selected into the study group. Patients from this group underwent scintigraphic assessment of gastric emptying between three to 11 months after the surgical procedure (an average 7 months). Furthermore, ten healthy volunteers (average age 28; range 19 to 43 years) constituted the control group.

Results. The average radiotracer retention after two hours was 44.7±6.5% in the study group and 51.1±7.4% (p>0.2) in the control group. Frequency of contractions of the whole prepyloric segment, as well as its distal fragment, in the subsequent periods of examination was comparable in both groups. Correlation among the frequency of contractions, contraction duration and duration of relaxation of the whole prepyloric segment and its distal fragment was high for the control group (correlation coefficients 0.71 p<0.001; 0.71 p=0; and 0.63 p=0, respectively). In the study group, correlation between the frequency of contractions and contraction duration was poor (coefficients of correlation 0.03 p>0.8 and -0.02 p>0.9), while correlation between duration of relaxation of the whole prepyloric segment and its distal fragment was moderate (coefficient of correlation 0.34 p>0.06).

Conclusions. Formation of a gastric substitute after its narrowing and denervation (truncal vagotomy) does not abolish gastric contractility. Frequency, amplitude, duration of contraction, and relaxation duration of the prepyloric portion of the ectopic substitute do not differ significantly from the patterns of motility of the upper gastrointestinal tract in healthy volunteers.

Open access

Marcin Barczyński, Aleksander Konturek, Małgorzata Stopa, Filip Gołkowski, Alicja Hubalewska-Dydejczyk, Stanisław Cichoń and Wojciech Nowak

Bilateral Neck Exploration with Intraoperative iPTH Assay in the ERA of Minimaly Invasive Parathyroidectomy

At present, the majority of patients with sporadic primary hyperparathyroidism (pHPT) qualify to minimally invasive parathyroidectomy (MIP). Nevertheless, in some patients, especially those with multiglandular parathyroid disease, achieving normocalcemia necessitates bilateral neck exploration (BNE).

The aim of the study was evaluation of current indications for BNE and results obtained employing this method in an endocrine surgery referral center.

Material and methods. A prospective analysis included 385 patients with pHPT qualified to parathyroidectomy (300 to MIP and 85 to BNE procedures) in the period between 12/2002 and 05/2008. Prior to the procedure, all the patients underwent preoperative imaging diagnostic studies (scintiscans of the parathyroids and ultrasound of the neck). Intraoperative parathormone assay was carried out in the course of all the operations. Indications for BNE and therapeutic results were evaluated.

Results. The most common indication for BNE was lack of preoperative location of a parathyroid adenoma in imaging studies aiming either at lateralization or regionalization (49.4%), followed by concomitant thyroid pathology that required surgical treatment (23.5%), MEN 1 syndrome (12.9%), long-term lithium therapy (5.9%), refusal of the patient to grant informed consent to a minimally invasive parathyroidectomy (5.9%) and MEN 2A syndrome (2.4%). In the discussed group, 31 subtotal parathyroidectomies were performed, along with ten resections of two parathyroid adenomas and 44 resections of single parathyroid adenomas. Intraoperative iPTH assay affected the extent of parathyroid tissues resection in eight (9.4%) cases. One case of persistent and one case of recurrent hyperparathyroidism were noted in the follow-up of mean 37.4 ± 19.4 months postoperatively.

Conclusions. In an endocrine surgery referral center, BNE is a procedure of choice in patients suspected of multiglandular parathyroid disease (MEN 1 and 2A, familial pHPT, long-term lithium therapy), in cases when a pathological parathyroid has not been located preoperatively and in patients which refuse their consent to MIP. Supplementing BNE with intraoperative iPTH assay allows for maintaining the highest quality of surgical treatment.

Open access

Paweł Ocłoń, Stanisław Łopata and Marzena Nowak

Abstract

The finite element method (FEM) is one of the most frequently used numerical methods for finding the approximate discrete point solution of partial differential equations (PDE). In this method, linear or nonlinear systems of equations, comprised after numerical discretization, are solved to obtain the numerical solution of PDE. The conjugate gradient algorithms are efficient iterative solvers for the large sparse linear systems. In this paper the performance of different conjugate gradient algorithms: conjugate gradient algorithm (CG), biconjugate gradient algorithm (BICG), biconjugate gradient stabilized algorithm (BICGSTAB), conjugate gradient squared algorithm (CGS) and biconjugate gradient stabilized algorithm with l GMRES restarts (BICGSTAB(l)) is compared when solving the steady-state axisymmetric heat conduction problem. Different values of l parameter are studied. The engineering problem for which this comparison is made is the two-dimensional, axisymmetric heat conduction in a finned circular tube.

Open access

Małgorzata Kandefer-Gola, Janusz A. Madej, Stanisław Dzimira, Izabela Janus, Marcin Nowak and Rafał Ciaputa

Abstract

The aim of the study was to assess the microvessel density based on the analysis of the expression of the CD31, VEGF, and LIMS-1 proteins in canine mast cell tumours. The study was conducted on 60 mastocytomas; 16 cases were classified as the grade I, 26 as the grade II, and 18 as the grade III. Statistical analysis showed a positive correlation only between the grade of the tumour and the expression of LIMS-1. In conclusion, LIMS-1 could be successfully used as a prognostic endothelial cell marker in mast cell tumour. CD31 may be a useful marker, but further examinations are necessary. VEGF is not recommended