Innovative Minichannel Condensers and Evaporators for Air Conditioning Equipment

The use of aluminum heat exchangers for refrigeration and air-conditioning equipment is very interesting since it allows to reduce weight and manufacturing costs while maintaining high performance. In this paper a two-phase heat transfer characterization of an innovative aluminum minichannel heat exchanger is presented. The heat exchanger (HX) is composed by rectangular channels with internal perforated turbolators. A special test section has been projected and realized in the Two Phase Heat Transfer Lab of the University of Padova in order to measure the heat transfer coefficient (HTC) on the refrigerant side during flow boiling and condensation. The test section has a single refrigerant channel with a perforated fin to make the minichannels. The test section is provided with 14 water flow modules installed at top and bottom of the refrigerant channel to promote boiling or condensation of the refrigerant. Therefore, the test section is made of seven different zones: each of them is equipped with 8 thermocouples to measure the wall temperature during the refrigerant phase change. The heat flow rate in each zone is calculated by an energy balance on the water side. Pressure transducers and thermocouples on the refrigerant side allow to determine the saturation temperature and thus the heat transfer coefficient of the refrigerant. The operating refrigerant used during tests is R410A. The particular scheme adopted for the test section enables to measure HTC at varying vapor quality and heat flow rate. Vaporization and condensation tests were carried out with different saturation temperatures, specific heat flow rate (from 40 to 150 kW/m2) and refrigerant mass flux (50÷150 kg/(m2 s) ). Data acquired have been compared with vaporization and condensation predictions from various correlations available in literature. This part of the work is very interesting since no data is available in the literature for such a geometry in vaporization nor in condensation. Therefore, the present paper will investigate the potential performance of these innovative minichannel heat exchangers as condensers and evaporators in air-conditioning equipment

Laparoscopic and robotic ureteral stenosis repair: a multi-institutional experience with a long-term follow-up

The treatment of ureteral strictures represents a challenge due to the variability of aetiology, site and extension of the stricture; it ranges from an end-to-end anastomosis or reimplantation into the bladder with a Boari flap or Psoas Hitch. Traditionally, these procedures have been done using an open access, but minimally invasive approaches have gained acceptance. The aim of this study is to evaluate the safety and feasibility and perioperative results of minimally invasive surgery for the treatment of ureteral stenosis with a long-term follow-up. Data of 62 laparoscopic (n\uc2 =\uc2 36) and robotic (n\uc2 =\uc2 26) treatments for ureteral stenosis in 9 Italian centers were reviewed. Patients were followed according to the referring center\ue2\u80\u99s protocol. Laparoscopic and robotic approaches were compared. All the procedures were completed successfully without open conversion. Average estimated blood loss in the two groups was 91.2\uc2 \uc2\ub1\uc2 71.9\uc2 cc for the laparoscopic and 47.2\uc2 \uc2\ub1\uc2 32.3\uc2 cc for the robotic, respectively (p\uc2 =\uc2 0.004). Mean days of hospitalization were 5.9\uc2 \uc2\ub1\uc2 2.4 for the laparoscopic group and 7.6\uc2 \uc2\ub1\uc2 3.4 for the robotic group (p\uc2 =\uc2 0.006). No differences were found in terms of operative time and post-operative complications. After a median follow-up of 27\uc2 months, the robotic group yielded 2 stenosis recurrence, instead the laparoscopic group shows no cases of recurrence (p\uc2 =\uc2 0.091). Minimally invasive approach for ureteral stenosis is safe and feasible. Both robotic and pure laparoscopic approaches may offer good results in terms of perioperative outcomes, low incidence of complications and recurrence

Impact of gastrointestinal side effects on patients’ reported quality of life trajectories after radiotherapy for prostate cancer: Data from the prospective, observational pros-it CNR study

Radiotherapy (RT) represents an important therapeutic option for the treatment of localized prostate cancer. The aim of the current study is to examine trajectories in patients’ reported quality of life (QoL) aspects related to bowel function and bother, considering data from the PROState cancer monitoring in ITaly from the National Research Council (Pros-IT CNR) study, analyzed with growth mixture models. Data for patients who underwent RT, either associated or not associated with androgen deprivation therapy, were considered. QoL outcomes were assessed over a 2-year period from the diagnosis, using the Italian version of the University of California Los Angeles-Prostate Cancer Index (Italian-UCLA-PCI). Three trajectories were identified for the bowel function; having three or more comorbidities and the use of 3D-CRT technique for RT were associated with the worst trajectory (OR = 3.80, 95% CI 2.04–7.08; OR = 2.17, 95% CI 1.22–3.87, respectively). Two trajectories were identified for the bowel bother scores; diabetes and the non-Image guided RT method were associated with being in the worst bowel bother trajectory group (OR = 1.69, 95% CI 1.06–2.67; OR = 2.57, 95% CI 1.70–3.86, respectively). The findings from this study suggest that the absence of comorbidities and the use of intensity modulated RT techniques with image guidance are related with a better tolerance to RT in terms of bowel side effects

Disease-specific and general health-related quality of life in newly diagnosed prostate cancer patients: The Pros-IT CNR study

Background: The National Research Council (CNR) prostate cancer monitoring project in Italy (Pros-IT CNR) is an observational, prospective, ongoing, multicentre study aiming to monitor a sample of Italian males diagnosed as new cases of prostate cancer. The present study aims to present data on the quality of life at time prostate cancer is diagnosed. Methods: One thousand seven hundred five patients were enrolled. Quality of life is evaluated at the time cancer was diagnosed and at subsequent assessments via the Italian version of the University of California Los Angeles-Prostate Cancer Index (UCLA-PCI) and the Short Form Health Survey (SF-12). Results: At diagnosis, lower scores on the physical component of the SF-12 were associated to older ages, obesity and the presence of 3+ moderate/severe comorbidities. Lower scores on the mental component were associated to younger ages, the presence of 3+ moderate/severe comorbidities and a T-score higher than one. Urinary and bowel functions according to UCLA-PCI were generally good. Almost 5% of the sample reported using at least one safety pad daily to control urinary loss; less than 3% reported moderate/severe problems attributable to bowel functions, and sexual function was a moderate/severe problem for 26.7%. Diabetes, 3+ moderate/severe comorbidities, T2 or T3-T4 categories and a Gleason score of eight or more were significantly associated with lower sexual function scores at diagnosis. Conclusions: Data collected by the Pros-IT CNR study have clarified the baseline status of newly diagnosed prostate cancer patients. A comprehensive assessment of quality of life will allow to objectively evaluate outcomes of different profile of care

A DSC Test for the Early Detection of Neoplastic Gastric Lesions in a Medium-Risk Gastric Cancer Area

In this study, we aimed to assess the accuracy of the proposed novel, noninvasive serum DSC test in predicting the risk of gastric cancer before the use of upper endoscopy. To validate the DSC test, we enrolled two series of individuals living in Veneto and Friuli-Venezia Giulia, Italy (n = 53 and n = 113, respectively), who were referred for an endoscopy. The classification used for the DSC test to predict gastric cancer risk combines the coefficient of the patient’s age and sex and serum pepsinogen I and II, gastrin 17, and anti-Helicobacter pylori immunoglobulin G concentrations in two equations: Y1 and Y2. The coefficient of variables and the Y1 and Y2 cutoff points (>0.385 and >0.294, respectively) were extrapolated using regression analysis and an ROC curve analysis of two retrospective datasets (300 cases for the Y1 equation and 200 cases for the Y2 equation). The first dataset included individuals with autoimmune atrophic gastritis and first-degree relatives with gastric cancer; the second dataset included blood donors. Demographic data were collected; serum pepsinogen, gastrin G17, and anti-Helicobacter pylori IgG concentrations were assayed using an automatic Maglumi system. Gastroscopies were performed by gastroenterologists using an Olympus video endoscope with detailed photographic documentation during examinations. Biopsies were taken at five standardized mucosa sites and were assessed by a pathologist for diagnosis. The accuracy of the DSC test in predicting neoplastic gastric lesions was estimated to be 74.657% (65%CI; 67.333% to 81.079%). The DSC test was found to be a useful, noninvasive, and simple approach to predicting gastric cancer risk in a population with a medium risk of developing gastric cancer

A DSC Test for the Early Detection of Neoplastic Gastric Lesions in a Medium-Risk Gastric Cancer Area

In this study, we aimed to assess the accuracy of the proposed novel, noninvasive serum DSC test in predicting the risk of gastric cancer before the use of upper endoscopy. To validate the DSC test, we enrolled two series of individuals living in Veneto and Friuli-Venezia Giulia, Italy (n = 53 and n = 113, respectively), who were referred for an endoscopy. The classification used for the DSC test to predict gastric cancer risk combines the coefficient of the patient’s age and sex and serum pepsinogen I and II, gastrin 17, and anti-Helicobacter pylori immunoglobulin G concentrations in two equations: Y1 and Y2. The coefficient of variables and the Y1 and Y2 cutoff points (>0.385 and >0.294, respectively) were extrapolated using regression analysis and an ROC curve analysis of two retrospective datasets (300 cases for the Y1 equation and 200 cases for the Y2 equation). The first dataset included individuals with autoimmune atrophic gastritis and first-degree relatives with gastric cancer; the second dataset included blood donors. Demographic data were collected; serum pepsinogen, gastrin G17, and anti-Helicobacter pylori IgG concentrations were assayed using an automatic Maglumi system. Gastroscopies were performed by gastroenterologists using an Olympus video endoscope with detailed photographic documentation during examinations. Biopsies were taken at five standardized mucosa sites and were assessed by a pathologist for diagnosis. The accuracy of the DSC test in predicting neoplastic gastric lesions was estimated to be 74.657% (65%CI; 67.333% to 81.079%). The DSC test was found to be a useful, noninvasive, and simple approach to predicting gastric cancer risk in a population with a medium risk of developing gastric cancer

Large bladder diverticula: a comparison between laparoscopic excision and endoscopic fulguration

Objective: The treatment of bladder diverticula consists of diverticulectomy, mainly by a laparoscopic approach or transurethral resection of the diverticular neck and fulguration of the mucosa. The endoscopic approach is generally dedicated to small diverticula. The aim of this study was to compare laparoscopic diverticulectomy versus endoscopic fulguration for bladder diverticula larger than 4\u2009cm. Materials and methods: A retrospective review of the medical records of consecutive patients undergoing endoscopic or laparoscopic treatment for bladder diverticula larger than 4\u2009cm at two tertiary hospitals was performed. Therapeutic success was defined as either complete resolution or a decrease of at least 80% in the size of the diverticulum. Complications were recorded and graded according to the Clavien\u2013Dindo classification. Results: All patients were treated with transurethral resection of the prostate in the same operative session. The endoscopic group included a cohort of 20 male patients. The median age, diverticular diameter and operative time were 65 years, 7\u2009cm and 62.5\u2009min, respectively. No early postoperative complications were observed. Therapeutic success was achieved in 15 cases (75%). The laparoscopic group included a cohort of 13 male patients with a median age of 63 years and median diverticular diameter of 7.0\u2009cm. The median operative time was 185\u2009min (p\u2009<\u20090.0001). Two grade III postoperative complications were observed (15.3%). Therapeutic success was achieved in all patients (100%). Conclusions: Acquired bladder diverticula larger than 4\u2009cm can be effectively managed either by a laparoscopic approach or by endoscopic fulguration