Thermal performance comparison between microchannel and round tube heat exchangers

Alternative round tube profiles to straight microchannel (SMC) tube geometry was explored by gradually applying the microchannel features to fin and tube type heat exchangers. First, previous experimental and computational works related to design and heat transfer analysis of microchannel heat exchanger tubes and testing was reviewed and then a numerical CFD model in FLUENT solver was developed, which was experimentally validated within an error range of 0.1 to 7.8 % based on available data in literature. Single phase, water to water, laminar, counter fluid flow of tube in shell calorimeter heat transfer experiments were numerically simulated to analyze the refrigerant side heat transfer enhancement if round microchannel tubes are used as outdoor coil. According to numerical results, the refrigerant side heat transfer capacity of round tubes of 10.3mm outer diameter with 42 microports of about 0.6 mm port diameter distributed around the tube perimeter (round tube microchannel) was estimated to be about 24% higher than conventional round tube (with no microchannel ports in them) and about 15% lower than conventional straight microchannel tube heat exchangers used in outdoor evaporators. In addition to refrigerant side, parametric studies were performed to investigate the heat transfer effectiveness of 10.3 mm and 5.15 mm outer diameter round (microchannel) tubes (multi port and annular) under cross flow configuration with dry air streams and results were compared with straight microchannel tubes in terms of tube diameter tube spacing effect. It was obtained that the round tube design of 5.15 mm outer diameter having an annular port of 1.6mm hydraulic diameter within 11mm edge to edge tube spacing of vertically parallel fin and tube coil configuration can provide similar air side heat transfer capacity of straight microchannel coil based on its secondary heat transfer area. Additionally, this configuration can provide 50 % better pressure drop performance compared to conventional straight microchannel tube coil.Mechanical & Aerospace Engineerin

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Echocardiographic reference ranges for normal cardiac Doppler data in healthy Turkish population: ECHO-DOP-TR Trial

Aim Doppler echocardiography has become the standard imaging modality for diastolic function and provides pathophysiological insight into systolic and diastolic heart failure. In this study, we aimed to obtain normal echocardiographic Doppler parameters of healthy Turkish population. Methods Among 31 collaborating institutions from all regions of Turkey, 1154 healthy volunteers were enrolled in this study. Predefined protocols were used for all participants during echocardiographic examination and The American Society of Echocardiography and European Association of Cardiovascular Imaging recommendations were used for echocardiographic Doppler measurements. Results A total of 967 healthy participants were enrolled in this study after applying exclusion criteria. Echocardiographic examination was obtained from all subjects following predefined protocols. Mitral E wave velocity andE/Aratio were higher in females and decreased progressively in advancing ages. E wave deceleration time and A wave velocity were increased with aging. Assessment of tissue Doppler velocities showed that left ventricular laterale ', septale ', and septals ' were higher in younger subjects and in females.E/e ' ratio was increased progressively with advancing decades. Right ventriculare ' ands ' were decreased buta ' was increased with increasing age. Septale ' lower than 8 cm/s was 1.9% in the fifth decade and 13.7% in ages older than 50 years. TheE/e ' ratio greater than 15 (and also 13) was not found. Conclusion This study, for the first time, provides echocardiographic reference ranges for normal cardiac Doppler data in healthy Turkish population which will be useful in routine clinical practice as well as in future clinical trials

Impact of deep phenotyping: high diagnostic yield in a diverse pediatric population of 172 patients through clinical whole-genome sequencing at a single center

Background: Pediatric patients with undiagnosed conditions, particularly those suspected of having Mendelian genetic disorders, pose a significant challenge in healthcare. This study investigates the diagnostic yield of whole-genome sequencing (WGS) in a pediatric cohort with diverse phenotypes, particularly focusing on the role of clinical expertise in interpreting WGS results.Methods: A retrospective cohort study was conducted at Acibadem University’s Maslak Hospital in Istanbul, Turkey, involving pediatric patients (0–18 years) who underwent diagnostic WGS testing. Clinical assessments, family histories, and previous laboratory and imaging studies were analyzed. Variants were classified and interpreted in conjunction with clinical findings.Results: The cohort comprised 172 pediatric patients, aged 0–5 years (62.8%). International patients (28.5%) were from 20 different countries. WGS was used as a first-tier approach in 61.6% of patients. The diagnostic yield of WGS reached 61.0%, enhanced by reclassification of variants of uncertain significance (VUS) through reverse phenotyping by an experienced clinical geneticist. Consanguinity was 18.6% of the overall cohort. Dual diagnoses were carried out for 8.5% of solved patients.Discussion: Our study particularly advocates for the selection of WGS as a first-tier testing approach in infants and children with rare diseases, who were under 5 years of age, thereby potentially shortening the duration of the diagnostic odyssey. The results also emphasize the critical role of a single clinical geneticist’s expertise in deep phenotyping and reverse phenotyping, which contributed significantly to the high diagnostic yield

Real life experience of patients with locally advanced gastric and gastroesophageal junction adenocarcinoma treated with neoadjuvant chemotherapy: a Turkish oncology group study

Neoadjuvant chemotherapy (NACT) in gastroesophageal junction (GEJ) and gastric cancer (GC) was shown to improve survival in recent studies. We aimed to share our real-life experience of patients who received NACT to compare the efficacy and toxicity profile of different chemotherapy regimens in our country. This retrospective multicentre study included locally advanced GC and GEJ cancer patients who received NACT between 2007 and 2021. Relation between CT regimens and pathological evaluation were analysed. A total of 794 patients from 45 oncology centers in Turkey were included. Median age at the time of diagnosis was 60 (range: 18-86). Most frequent NACT regimens used were FLOT (65.4%), DCF (17.4%) and ECF (8.1%), respectively. In the total study group, pathological complete remission (pCR) rate was 7.2%, R0 resection rate 86.4%, and D2 dissection rate was 66.8%. Rate of pCR and near-CR (24%), and R0 resection (84%) were numerically higher in FLOT arm (p > 0.05). Patients who received FLOT had also higher chemotherapy-related toxicity rate compared to patients who received other regimens (p > 0.05). Median follow-up time was 16 months (range: 1-154 months). Estimated median overall survival (OS) was 58.4months (95% CI: 35.2-85.7) and disease-free survival (DFS) was 50.7 months (95% CI: 25.4-75.9). The highest 3-year estimated OS rate was also shown in FLOT arm (68%). We still do not know which NACT regimen is the best choice for daily practice. Clinicians should tailor treatment regimens according to patients' multifactorial status and comorbidities for to obtain best outcomes. Longer follow-up period needs to validate our results

Prevalence of Anosmia in 10.157 Pediatric COVID-19 Cases: Multicenter Study from Turkey.

Introduction: COVID-19-related anosmia is a remarkable and disease-specific finding. With this multicenter cohort study, we aimed to determine the prevalence of anosmia in pediatric cases with COVID-19 from Turkey and make an objective assessment with a smell awareness questionnaire. Material and Methods: This multicenter prospective cohort study was conducted with pediatric infection clinics in 37 centers in 19 different cities of Turkey between October 2020 and March 2021. The symptoms of 10.157 COVID-19 cases 10-18 years old were examined. Age, gender, other accompanying symptoms, and clinical severity of the disease of cases with anosmia and ageusia included in the study were recorded. The cases were interviewed for the smell awareness questionnaire at admission and one month after the illness. Results: Anosmia was present in 12.5% (1.266/10.157) of COVID-19 cases 10-18 years of age. The complete records of 1053 patients followed during the study period were analyzed. The most common symptoms accompanying symptoms with anosmia were ageusia in 885 (84%) cases, fatigue in 534 cases (50.7%), and cough in 466 cases (44.3%). Anosmia was recorded as the only symptom in 84 (8%) of the cases. One month later, it was determined that anosmia persisted in 88 (8.4%) cases. In the smell awareness questionnaire, the score at admission was higher than the score one month later (P < 0.001). Discussion: With this study, we have provided the examination of a large case series across Turkey. Anosmia and ageusia are specific symptoms seen in cases of COVID-19. With the detection of these symptoms, it should be aimed to isolate COVID-19 cases in the early period and reduce the spread of the infection. Such studies are important because the course of COVID-19 in children differs from adults and there is limited data on the prevalence of anosmia

The prevalence of childhood psychopathology in Turkey: a cross-sectional multicenter nationwide study (EPICPAT-T).

Aim: The aim of this study was to determine the prevalence of childhood psychopathologies in Turkey

The prevalence of childhood psychopathology in Turkey: a cross-sectional multicenter nationwide study (EPICPAT-T)

Conclusion: This is the largest and most comprehensive epidemiological study to determine the prevalence of psychopathologies in children and adolescents in Turkey. Our results partly higher than, and partly comparable to previous national and international studies. It also contributes to the literature by determining the independent predictors of psychopathologies in this age group