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EN
This paper is devoted to application of adsorption process for cooling power generation in a cooling devices. Construction and working principle of a water-silica gel adsorption chiller has been presented and the basic refrigeration cycle has been discussed. The article outlines behavior of a single-stage adsorption system influenced by changes in cycle time. The effect of cycle time and inlet chilled water temperatures on the main system performance parameters has been analysed
EN
The aim of the study was to present our own experience in the treatment of anal fistulas by means of VAAFT (Video-Assisted Anal Fistula Treatment). Material and methods. Twenty patients were qualified for the VAAFT procedure. All were subjected to diagnostics. Two patients after the diagnostic stage underwent classical fistula surgery. The remaining 18 patients were subjected to the full procedure (diagnostic fistuloscopy, supply of the internal ostium, and coagulation of the fistula canal). The mean observation period was 10 months. Results. In most cases the trans-sphincter fistula was observed during the diagnostic phase, including three with additional fluid compartments. There was one intersphincteric fistula. Considering the 18 patients subjected to the full VAAFT procedure the internal ostium was supplied by means of an advancement flap in 3 cases, while in 11 by means of a mattress suture, including one with additional tissue glue. In 4 cases the internal ostium was tightly covered by mucosa. Surgical complications were not observed during the procedure. During further observation a permanent fistula was observed in 4 (22%) patients, and in two (17%), recurrence of anal fistula. In the remaining 12 patients one observed healing without fistula recurrence. Complications were not observed, including stool and gas control deterioration (based on the FISI scoring). Conclusions. The VAAFT method does not affect sphincter efficiency, no intra- and postoperative complications were observed. As compared to other minimally invasive procedures a comparable recovery rate is observed without the risk of incontinence. It is the only method enabling the intraoperative identification of the internal ostium and fistula canal under visual control. Initial optimistic results require further investigations on a larger group of patients.
EN
Ligation of intersphincteric fistula tract in treatment of anal fistulas (LIFT) is being said to have satisfactory results in short and long follow up, with low risk of complications. This study was designed to evaluate the results in patients with complex and recurrent fistulas in comparison with simple transsphincteric anal fistulas. The aim of the study was to present a single-center experience in LIFT procedure in treatment of both simple and complex anal fistulas, including recurrent fistulas, in comparison with a review of current literature. Material and methods. A series of 17 patients were qualified to LIFT procedure. 5 patients were treated for simple transsphincteric, 6 for complex fistulas, 6 with fistulas recurrent after fistulotomy. Median age was 47, most of the patients were male (16/17). Mean follow up was 11 months. Results. Mean operating time was 55 minutes counting from surgical site disinfection to final dressing of the wound. Of the 17 patients the overall success rate was 53%. As expected, best results were achieved in patients with simple fistulas (80% success rate), then complex (50%), and recurrent fistulas (only 33%). There were no early nor late complications of the surgery. Conclusion. As expected, in simple transsphincteric fistulas the results were satisfactory, taking into account low complication rate. Complex and recurrent fistulas seem to be risk factors of LIFT failure. The results are consistent with data published by other authors, based on the review of the current literature, and it seems there is still room for improvement, so further research is required.
EN
The paper is focused on the idea of a combustion modelling of a large-scale circulating fluidised bed boiler (CFB) during coal and biomass co-combustion. Numerical computation results for three solid biomass fuels co-combustion with lignite are presented in the paper. The results of the calculation showed that in previously established kinetics equations for coal combustion, some reactions had to be modified as the combustion conditions changed with the fuel blend composition. Obtained CO2, CO, SO2 and NOx emissions are located in borders of ± 20% in the relationship to the experimental data. Experimental data was obtained for forest biomass, sunflower husk, willow and lignite cocombustion tests carried out on the atmospheric 261 MWe COMPACT CFB boiler operated in PGE Turow Power Station in Poland. The energy fraction of biomass in fuel blend was: 7%wt, 10%wt and 15%wt. The measured emissions of CO, SO2 and NOx (i.e. NO + NO2) were also shown in the paper. For all types of biomass added to the fuel blends the emission of the gaseous pollutants was lower than that for coal combustion.
EN
The purpose of this work is to find a correlation for heat transfer to walls in a 1296 t/h supercritical circulating fluidised bed (CFB) boiler. The effect of bed-to-wall heat transfer coefficient in a long active heat transfer surface was discussed, excluding the radiation component. Experiments for four different unit loads (i.e. 100% MCR, 80% MCR, 60% MCR and 40% MCR) were conducted at a constant excess air ratio and high level of bed pressure (ca. 6 kPa) in each test run. The empirical correlation of the heat transfer coefficient in a large-scale CFB boiler was mainly determined by two key operating parameters, suspension density and bed temperature. Furthermore, data processing was used in order to develop empirical correlation ranges between 3.05 to 5.35 m·s-1 for gas superficial velocity, 0.25 to 0.51 for the ratio of the secondary to the primary air, 1028 to 1137K for bed temperature inside the furnace chamber of a commercial CFB boiler, and 1.20 to 553 kg·m-3 for suspension density. The suspension density was specified on the base of pressure measurements inside the boiler’s combustion chamber using pressure sensors. Pressure measurements were collected at the measuring ports situated on the front wall of the combustion chamber. The obtained correlation of the heat transfer coefficient is in agreement with the data obtained from typical industrial CFB boilers.
EN
Heath related quality of life has been an important object of interest in the clinical practice, focused on assessment of treatment effects from patient's point of view, with particular emphasis placed on effect of treatment on daily patient functioning. Concept of health-related quality of life needs valid and reliable instruments.The aim of the study was to present the process of validation of a new version of EORTC QLQ-CR29 module in Polish patients suffering from rectal cancer.Material and methods. EORTC QLQ-CR29 module comprises 29 questions, and was adapted to Polish cultural conditions based on EORTC procedure. Data collected from 20 patients were analyzed, their agreement with theoretical and empirical structure was assessed. Convergent and discriminant validity were analyzed with multi trait scaling.Reliability was assessed with Cronbach alpha coefficient. Known group validity was assessed in terms of differences between men and women, and between stoma and non-stoma patients. Exact Mann-Whitney test was used. P values lower than 0.05 were considered significant.Results. Scales built on bases of empirical model of module had higher validity and reliability than those based on theoretical model.There were no significant differences between men and women in health-related quality of life. Significantly higher values were observed in non-stoma patients on body image scale and for leakage of stool item. Reversed relationship was observed in case of abdominal and buttocks pain, as well as embarrassment because of bowel movements.Conclusions. Module CR29 is a valid and reliable tool, which enables standardized measurement of treatment effects, suggested for use as main tool measuring impact of disease itself and applied treatment on health-related quality of life of rectal cancer patients.
EN
This paper presents a study on nitrogen conversion in oxy-fuel coal combustion in a pilot scale CFB 0.1 MWth facility. The paper is focused on fuel-N behaviour in the combustion chamber when the combustion process is accomplished under oxy-fuel CFB conditions. The analysis is based on infurnace sampling of flue gas and calculations of the conversion ratios of fuel-nitrogen (fuel-N) to NO, NO2, N2O, NH3 and HCN. For the tests, O2/CO2 mixtures with the oxygen content of 21 vol.% (primary gas) and with the oxygen content varied from 21 to 35 vol.% (secondary gas), were used as the fluidising gas. Measurements were carried out in 4 control points located along the combustion chamber: 0.43 m, 1.45 m, 2.50 m and 4.88 m. Results presented below indicate that an increased oxygen concentration in the higher part of the combustion chamber has strong influence on the behaviour of fuel based nitrogen compounds.
EN
The aim of the study was to assess the influence of neoadjuvant radiotherapy and resection of the rectum on the functional parameters of anal sphincters.Material and methods. 20 patients with rectal cancer, qualified for low anterior rectal resection with neoadjuvant radiotherapy were enrolled in the study group. The study protocol included an anorectal manometry, electromyography and fecal incontinence questionnaire (FISI) before radiotherapy, after radiotherapy, and after the operation.Results. Of the 20 patients 12 were included in the final analysis, because 8 patients were re-qualified to abdomino-perineal resection of the rectum after neoadjuvant treatment. There were no significant changes in anal pressures assessed 5 to 8 days after radiotherapy. In 3 cases (25%) pathological changes in RAIR reflex were found in the manometric examination. After low anterior resection mean basal anal pressures were significantly lower, whereas squeeze anal pressures did not change significantly. In 7 patients (58%) the RAIR reflex was pathological or even absent after low anterior resection. Changes in manometric parameters correlated with FISI incontinence assessment after the operation. In electromyographic examination action potentials of motoric units of the external anal sphincter were still present both after radiotherapy, and after operation.Conclusions. Fecal incontinence after low anterior resection of the rectum seems to be caused mostly by changes in autonomic functionality of anal sphincters and lack of compliance of the neorectum, since the influence of neoadjuvant radiotherapy and the operation itself on the somatic innervation of anal sphincters seems to be minimal.
EN
The recurrent laryngeal nerve (RLN) is particularly prone to injury during thyroidectomy in case of extralaryngeal bifurcation being present in approximately one-third of patients near the inferior thyroid artery or ligament of Berry. Meticulous surgical dissection in this area may be additionally facilitated by the use of intraoperative neuromonitoring (IONM) to assure safe and complete removal of thyroid tissue.The aim of the study was to verify the hypothesis that meticulous surgical technique of tissue dissection in the area of the posterior surface of the thyroid capsule and adjacent RLN may be additionally facilitated by intraoperative neuromonitoring (IONM), and may contribute to increasing the safety and radicalness of total thyroidectomy in patients with well-differentiated thyroid cancer.Material and methods. The outcomes of total thyroidectomy with level VI lymph node clearance for well-differentiated thyroid cancer (WDTC; pT1-3, N0-1, Mx) were retrospectively compared between 151 patients undergoing surgery with IONM (01/2005-06/2009) and 151 patients undergoing surgery without IONM (2003-2004). RLN morbidity (calculated for nerves at risk) was assessed by videolaryngoscopy or indirect laryngoscopy (mandatory before and after surgery and at 12-month follow-up). The anatomical course of the extralaryngeal segment of RLNs were analyzed in detail in each operation. Thyroid iodine uptake (131I) was measured during endogenous TSH stimulation test a week before radioiodine therapy.Results. Among patients operated with vs. without IONM, the early RLN injury rate was 3% vs. 6.7% (p=0.02), including 2% vs. 5% (p=0.04) of temporary nerve lesions, and 1% vs. 1.7% of permanent nerve events (p=0.31), respectively. Extralaryngeal RLN bifurcation was identified in 42 (27.8%) vs. 25 (16.6%) of patients operated with vs. without IONM, respectively (p=0.001). Mean I-131 uptake following total thyroidectomy with vs. without IONM was 0.67 ± 0.39% vs. 1.59 ± 0.69% (p<0.001). 131I uptake lower than 1% was found in 106 (70.2%) vs. 38 (25.2%) patients operated with vs. without IONM, respectively (p<0.001).Conclusions. Most patients with WDTC who undergo total thyroidectomy have a small amount of residual thyroid tissue. The use of IONM may improve the outcomes of surgery among these patients by both increasing the completeness of total thyroidectomy and significantly reducing the prevalence of temporary RLN injury. The possible mechanism of this improvement is the aid in dissection at the level of the Berry's ligament offered by IONM which enhances the surgeon's ability to identify a branched RLN, and allows for reduction of traction injury and neuropraxia of the anterior branch of bifid nerves.
EN
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.
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