120 research outputs found

    Evolution Criterion in the Coupled Fields Theory

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    The evolution criterion, as formulated by Glansdorff and Prigogine, allows to find the kinetic potential describing a dissipative process. This paper deals with the construction of the kinetic potential for micropolar media embedded in the dielectric fluid and subjected to the coupled field interactions. We extend the results derived by Muschik and Papenfafl in Muschik and Papenfuss (1.993) for the liquid crystals immersed in the perfect fluid, playing there the role of the thermostat. Generalization deals with the dissipative coupled mechanical, thermal, and electromagnetic processes occurring in the micropolar medium. The description of the micropolar medium is based on the approach of Eringen (Eringen, 1999). The formulated criterion is applied to obtain the equilibrium conditions for micropolar elastic solids, micropolar electromagnetic fluids, and liquid crystals

    Diagnostic difficulties in the differentiation of urine retention and developmental anomalies in the pelvicalyceal system in the ultrasound examination of children

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    Ultrasound examination of the abdominal cavity is part of the baseline diagnostics of urinary tract diseases. Dilatation of the pelvicalyceal system is one of the most frequent findings. In ultrasonography of the urinary tract there are, however, some images of anatomical anomalies of the pelvicalyceal system which should not be consider as abnormal. In the study we analysed 920 ultrasound examinations of the urinary tract. Of all the ultrasound images only those with isolated dilatation of the renal pelvises and calices were selected (130 cases). Ampulla-shaped and/or external pelvises, isolated calices or both abnormalities were disclosed in 104, 46 and 20 cases, respectively. In about one-third of patients additional examinations (voiding cystography, intravenous urography, renal scyntygraphy) were performed which revealed normal anatomy of the urinary tract and disorders of urine flow in 80% and 20% of patients, respectively. In conclusion, the study implies that not all dilatation of the pelvicalyceal system structures signifies urine retention, although in the event of further doubt, there is a need for additional diagnostics

    The morphology and application of stem cells in digestive system surgery

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    Background: Stem cells constitute a group of cells which possess the ability to self-renew as well as the capacity to differentiate into a vast number of different cells within the human organism. Moreover, stem cells are able to undergo a potentially unlimited number of divisions and this characteristic is clinically essential. Specific fields of its application include treatment of diseases mainly in the field of haematology, orthopaedics, surgery, dentistry, and neurology. Materials and methods: In the following work, the current knowledge concerning mechanisms of stem cell treatment in different parts of the digestive system with its diseases as well as adjacent therapy for surgery has been revised. Results: Stem cells therapy may be used in the treatment of various diseases of different parts of the digestive system. This also applies to the end part of the digestive tract (proctological diseases) because stem cells can be used to treat fistulas. Liposuction allows more recovery of mesenchymal stem cells, compared to previous bone marrow harvesting methods. Despite the application of stem cells in the treatment of different diseases used for many years so far, the therapeutic use for the regeneration of the gastrointestinal tract is still rare and unfamiliar. Conclusions: Regenerative medicine seems to be a promising tool in medical research, especially when insulated cells and designed biomaterials are taken into consideration. Major points of discussion include types of stem cells, their origin or differentiation for the treatment of many diseases

    Mechanisms of the Epithelial-Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

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    Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world's population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial-mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial-mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer

    Constrictive bronchiolitis obliterans in patient with Castelman’s disease

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    A 37-year-old woman with hialin- vascular type Castelman’s disease (CD) localised in the retroperitoneal region, incompletely resected, developed progressive dyspnoea. The chest radiograph taken 3 months before the operation was normal. The chest CT scan revealed diffused bronchiectases, hyperinflation and air trapping. Pulmonary function tests disclosed severe obstructive impairment with hyperinflation. The bronchoscopic examination of the bronchial tree was normal. Cultures of sputum, bronchial washing and blood were negative. No pemphigus antibodies were found. Mycoplasmal, chlamydial and viral infections were excluded. Histological examination of specimens obtained by open lung biopsy revealed bronchiolar inflammation, submucosal bronchial fibrosis with obliteration of bronchiolar lumen. Constrictive bronchiolitis obliterans (CBO) was diagnosed. Despite slight clinical and spirometric improvements that were achieved due to corticosteroid therapy, one year later she died as a result of respiratory failure. It is widely known that patients with CD develop CBO during the course of paraneoplastic pemphigus. However we present the case of CBO and CD but without any symptoms of this condition

    Implicator-conjunctor based models of fuzzy rough sets: definitions and properties

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    Ever since the first hybrid fuzzy rough set model was proposed in the early 1990' s, many researchers have focused on the definition of the lower and upper approximation of a fuzzy set by means of a fuzzy relation. In this paper, we review those proposals which generalize the logical connectives and quantifiers present in the rough set approximations by means of corresponding fuzzy logic operations. We introduce a general model which encapsulates all of these proposals, evaluate it w.r.t. a number of desirable properties, and refine the existing axiomatic approach to characterize lower and upper approximation operators

    Non-small-cell lung cancer in a French department, (1982–1997): management and outcome

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    Addition of chemotherapy to the treatment of non-small-cell lung cancer (NSCLC) resulted in a modest but clear improvement in the survival of selected patients. To ascertain if this translates to improved survival in the whole population of patients, we conducted a retrospective population-based study of a sample of 1738 patients diagnosed with primary NSCLC in a French department between 1982 and 1997. The proportion of women, metastatic cases and adenocarcinoma changed significantly over time, as did their management: use of chemotherapy alone increased from 9.7 to 28.1% (P<0.0001), while the use of radiotherapy alone decreased from 32.2 to 9.4% (P<0.0001). The 5-year survival probability was 15.7 % for all patients and 32.6% for those with resectable disease. The 1- and 2-year survival probabilities were 38.2 and 15.6% in locally advanced disease, and were, respectively, 16.8 and 5.2% in metastatic disease. Disease extent and histological subtype were significant independent prognostic factors. Survival of resectable disease was longer among patients treated with surgery or surgery plus chemotherapy, while better outcomes for locally advanced disease were associated with radiation plus chemotherapy. In metastastic disease, patients treated by classical agent without platin or palliative care only had the shortest survival. Despite changes in treatment in accordance with the state-of-the-art, overall survival did not improve over time. It is not unlikely that more patients with bad PS were diagnosed during the latter end of the study period. This could at least partially explain the absence of detection of an overall improvement in survival

    Do genetic factors protect for early onset lung cancer? A case control study before the age of 50 years

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    <p>Abstract</p> <p>Background</p> <p>Early onset lung cancer shows some familial aggregation, pointing to a genetic predisposition. This study was set up to investigate the role of candidate genes in the susceptibility to lung cancer patients younger than 51 years at diagnosis.</p> <p>Methods</p> <p>246 patients with a primary, histologically or cytologically confirmed neoplasm, recruited from 2000 to 2003 in major lung clinics across Germany, were matched to 223 unrelated healthy controls. 11 single nucleotide polymorphisms of genes with reported associations to lung cancer have been genotyped.</p> <p>Results</p> <p>Genetic associations or gene-smoking interactions was found for <it>GPX1(Pro200Leu) </it>and <it>EPHX1(His113Tyr)</it>. Carriers of the Leu-allele of <it>GPX1(Pro200Leu) </it>showed a significant risk reduction of OR = 0.6 (95% CI: 0.4–0.8, p = 0.002) in general and of OR = 0.3 (95% CI:0.1–0.8, p = 0.012) within heavy smokers. We could also find a risk decreasing genetic effect for His-carriers of <it>EPHX1(His113Tyr) </it>for moderate smokers (OR = 0.2, 95% CI:0.1–0.7, p = 0.012). Considered both variants together, a monotone decrease of the OR was found for smokers (OR of 0.20; 95% CI: 0.07–0.60) for each protective allele.</p> <p>Conclusion</p> <p>Smoking is the most important risk factor for young lung cancer patients. However, this study provides some support for the T-Allel of <it>GPX1(Pro200Leu) </it>and the C-Allele of <it>EPHX1(His113Tyr) </it>to play a protective role in early onset lung cancer susceptibility.</p
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