OPTIMISATION OF DIFFUSION GAS BURNER UTILISATION

A gas burner is a device which delivers defined amounts of gas fuel and oxidiser to the combustion zone as well as stabilises the flame at its outlet and ensures it has required parameters, i.e. a proper shape and, determined by the heating process, an appropriate level and a balanced distribution of temperatures. Selecting a burner for an existing furnace and designing a new burner for a furnace under development are very complex tasks. Intensification of flame gas dynamics requires high pressure to ensure a high outflow substrate velocity. In the paper, aspects of optimal utilisation of diffusion gas burners are presented. The effects of design and gas-dynamic parameters on burner operation in terms of applied optimisation criteria were analysed. The combustion process was found to influence a change in the air flow characteristics, limiting the potential for achieving the nominal power of the burner with no increased overpressure of the combustion air

Neuropathic alterations of the myenteric plexus neurons following subacute intraperitoneal administration of salsolinol

Introduction. Impairment of the enteric nervous system has been suggested to occur within the pathogenesis of neurodegenerative diseases. Thus, in the current study, we consider salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, SAL) as a substance that can potentially induce myenteric neurodegen­eration. Material and methods. Male Wistar rats were subjected to continuous intraperitoneal dosing of salsolinol (200 mg/kg in total) with osmotic mini-pumps for either two or four weeks. An equivalent group of rats served as the control. Jejunal myenteric neurons were subjected to immunofluorescence staining to detect neuron specific protein — protein gene product (pan-neuronal marker, PGP 9.5), nitric oxide synthase (NOS), choline acetyltransferase (ChAT), Bax-protein and alpha-synuclein. In search of any functional impairment within the gastrointestinal tract, gut motility was assessed by determining the residual solid food contents in the stomach and the small and large intestine transit. Results. The myenteric neuron count, the mean size of the neuron body, the area of ganglia and the diameter of nerve strands were decreased in both of the salsolinol-treated groups compared with the controls. The number of NOS-positive cells was lower in the salsolinol-treated groups, while the number of ChAT-positive cells remained unchanged in comparison with the controls. Neurons expressing the pro-apoptotic Bax protein and alpha-synuclein deposits were observed among the myenteric neurons of the salsolinol-treated rats. Conclusions. Salsolinol evokes enteric neuronal cell death via initiation of apoptosis and leads to the formation of pathological aggregates of alpha-synuclein. Impairment of myenteric neurons, mainly the inhibitory motor neurons, might be responsible for the abnormal intestinal transit. Thus, salsolinol might be regarded as a suitable compound for inducing experimental enteric neurodegeneration in rats

FLOW INVESTIGATIONS ON THE SUBSTRATE DELIVERY SYSTEM IN A GAS BURNER

Applied combustion systems should ensure the optimal safety of operation and required qualitative parameters of a technological process. Selection of the path equipment components is determined by pressure drops resulting from local flow resistances and by the utilisation requirements of a heated device. Their flow characteristics as well as methods for calculating pressure drops in the system and local resistance numbers are presented. The combustion process was found to influence a change in the airflow characteristics, limiting the potential for achieving the nominal power of the burner with no increased overpressure of the combustion air. The determined flow characteristics and local resistance number values can be used for the algorithms of burner designs in order to obtain optimal operating parameters

Co-existence of apoptotic and necrotic features within one single cell as a result of menadione treatment

In the present study we examined the effects of menadione, a redox cycling agent, on structural changes of human osteosarcoma line 143B cells. It has been previously reported that menadione can cause necrotic or apoptotic cell death in a concentration- depending manner. In our experimental model, cells were treated with 100 μM menadione for 24 hours. Using electron microscopy technique cells carrying three kinds of morphological changes were detected: necrotic cells, apoptotic cells and those demonstrating a co-existence of apoptotic and necrotic features in one single cell

Telocytes : new insight into the pathogenesis of gallstone disease

The major mechanisms of gallstone formation include biliary cholesterol hypersecretion, supersaturation and crystallization, mucus hypersecretion, gel formation and bile stasis. Gallbladder hypomotility seems to be a key event that triggers the precipitation of cholesterol microcrystals from supersaturated lithogenic bile. Telocytes, a new type of interstitial cells, have been recently identified in many organs, including gallbladder. Considering telocyte functions, it is presumed that these cells might be involved in the signalling processes. The purpose of this study was to correlate the quantity of telocytes in the gallbladder with the lithogenicity of bile. Gallbladder specimens were collected from 24 patients who underwent elective laparoscopic cholecystectomy for symptomatic gallstone disease. The control group consisted of 25 consecutive patients who received elective treatment for pancreatic head tumours. Telocytes were visualized in paraffin sections of gallbladders with double immunofluorescence using primary antibodies against c‐Kit (anti‐CD117) and anti‐mast cell tryptase. Cholesterol, phospholipid and bile acid levels were measured in gallbladder bile. The number of telocytes in the gallbladder wall was significantly lower in the study group than that in the control group (3.03 ± 1.43 versus 6.34 ± 1.66 cell/field of view in the muscularis propria, P < 0.001) and correlated with a significant increase in the cholesterol saturation index. The glycocholic and taurocholic acid levels were significantly elevated in the control subjects compared with the study group. The results suggest that bile composition may play an important role in the reduction in telocytes density in the gallbladder

The assessment of pit pattern on the polyps' surface as the essential part of high quality colonoscopy

The meaning of the term high-quality endoscopy is gradually widening and consists of multiple elements. The highest possible quality of colonoscopies constitutes the basis of anticancer protective action by the identification and treatment of early precancerous lesions. Data from randomised trials demonstrate that only top quality endoscopy has a protective value against colon cancer morbidity. On the other hand, data coming from medical centres which do not meet high standards confirm the lack of protective anticancer value of low-quality colonoscopies and an increased rate of interval cancers. The fundamental indicators of high standards are: caecal intubation rate, adenoma detection rate, colonoscopy withdrawal time and bowel preparation. These parameters are gradually widened to include other factors such as: proximal colon polyp detection rate, retrieval rate of removed polyps, sedation practice and many others. One of the biggest challenges we have to face is the effort to perform endoscopic visual assessment of polyps in vivo. The principal aim of this action is to reduce the number of redundant histopathological tests and in general to reduce histopathology workload for very low-risk lesions, especially polyps ≤5 mm in diameter, this being the so called "resect and discard" strategy. One of useful tools is the assessment of the pattern of colonic crypt outlets, known as the pit pattern. The combination of the pit pattern and the Paris polyp classification determine high-risk lesions well in terms of advanced histology and technical problems with safe removal. Lesions originally found as unresectable should be reassessed and resected endoscopically in experienced expert centres

Acute aortic dissection in a patient with long-standing untreated hypertension and metabolic syndrome

Ostre rozwarstwienie aorty jest jednym z potencjalnych powikłań nieleczonego nadciśnienia tętniczego. Jego objawy, w tym silny rozrywający ból zamostkowy promieniujący do kręgosłupa, często sugerują ostry zespół wieńcowy. Podstawą diagnozy jest wykonanie tomografii komputerowej aorty. Pacjenci z ostrym rozwarstwieniem aorty wymagają pilnej operacji naczyniowej. Jednym z warunków jej powodzenia i dobrego rokowania jest uzyskanie redukcji wartości ciśnienia tętniczego. W pracy przedstawiono przypadek pacjenta z nieleczonym wieloletnim nadciśnieniem tętniczym, u którego doszło do rozwarstwienia aorty zstępującej oraz jej odgałęzień i w konsekwencji do pogorszenia funkcji nerek. Po początkowych trudnościach w ustaleniu optymalnej farmakoterapii uzyskano redukcję wartości ciśnienia tętniczego oraz nie obserwuje się poszerzenia wrót rozwarstwienia.Acute aortic dissection (AOD) is one of the possible complications of untreated hypertension. Its symptoms (severepopping chest pain radiating to the back) are often confused with acute coronary syndrome. The basis of diagnosis isa computed tomography of the aorta. Patients with AOD requires emergency vascular surgery. One of the conditions forthe success and good prognosis is to reduce blood pressure. The paper presents a case of a patient with long-standinguntreated hypertension, in whom there was a dissection of the descending aorta and its branches, and consequentlythe deterioration of renal function. After initial difficulties in determining the optimal pharmacotherapy reduction ofblood pressure was achieved and widening gates delamination is not observed