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•Pressure differences across the façade negatively affect room ventilation units.•Units with axial fans are more sensitive compared to units with centrifugal fans.•The resulting ...imbalance between supply and exhaust is higher at lower fan speeds.•A humidity-controlled damper can be used in the intake of a natural ventilation shaft.•This can mitigate the pressure differences across the façade due to stack effect.
Room ventilation units (RVUs) with heat recovery represent an alternative ventilation solution for renovated residential buildings, allowing simple installation through the façade. However, wind pressure on the façade can have a substantial impact on fan performance and thus affect the airflows through the RVU. Airflow imbalances between supply and exhaust negatively affect total heat recovery and supply air temperatures. Moreover, RVUs installed in apartments on the ground floor of multi-story buildings with a natural ventilation shaft are highly affected by negative pressures due to stack effect during winter periods. The issues that characterize these units were examined in this study in relation to the fan type and fan operation, aiming to establish why the performance is varying for different units. The study simulated the performance of RVUs in a typical Danish test apartment under various wind pressure conditions. To investigate the combined impacts of wind and stack effect, the simulations assumed the test apartment being located on the ground floor of a 4-storey building with an 11-meter natural ventilation shaft. The authors performed dynamic annual simulations with different fan characteristic curves and fan operating points for centrifugal and axial fans. Simulations tested the additional impact of adding a humidity-controlled damper in the intake of the natural ventilation shaft to reduce pressure differences across the building envelope due to stack effect. Results showed that centrifugal fans were less sensitive to pressure differences than axial fans due to their steeper fan curves and generally higher operating pressures. When taking into account wind pressure and disregarding stack effect, the sensible heat recovery decreased by up to 8% in RVUs with centrifugal fans and up to 22% in RVUs with axial fans at the same airflow settings. After including stack effect, the decrease in sensible heat recovery was instead up to 20% for RVUs with centrifugal fans and up to 52% for RVUs with axial fans. The inclusion of a humidity-controlled damper reduced the pressure differences due to stack effect and halved the negative impact on sensible heat recovery on average. As a result, the RVUs were able to provide considerably higher supply air temperatures. The study showed that a humidity-controlled damper could reduce the negative impact of stack effect on the performance of an RVU.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Humidity-controlled mechanical exhaust ventilation (RH-MEV) has been widely used in France for over 35 years, demonstrating high durability and robustness. This exhaust-only ventilation strategy is ...widely used as an energy-saving measure, replacing constant mechanical exhaust ventilation (Constant-MEV) systems in residential buildings. It demonstrates energy savings due to the restricted airflows, but as a downside, the building's indoor air quality (IAQ) often deteriorates. Moreover, it is impossible to recover heat with exhaust-only ventilation systems, which means that energy consumption for space heating is still quite significant and cold supply air temperatures are frequently introduced to the heated spaces. Room ventilation units (RVUs) with heat recovery represent an alternative ventilation solution allowing simple installation through the façade and providing fresh outdoor air and exhaust ventilation to each room. This study investigates these units' energy saving potential and indoor environmental quality performance as an alternative solution to centralized exhaust-only ventilation systems. The dynamic simulations were performed for a reference residential building under various French climatic conditions for a heating season. The three ventilation strategies investigated were Constant-MEV, RH-MEV and room-based ventilation with RVUs. The results demonstrated 61-85% savings in space heating demand with the RVUs, compared to Constant-MEV under all climatic conditions. Compared to RH-MEV, the RVUs saved 44-75% energy for space heating while the CO
2
concentration and relative humidity levels were decreased due to RVUs' constant air exchange rate. In all cases, RVUs provided considerably higher supply air temperatures due to the implemented heat recovery, which can potentially improve indoor thermal comfort.
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BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
Objective: Assessing arterial properties in patients with aortic valve stenosis undergoing surgical aortic valve replacement (SAVR) is difficult, and the results to date have been inconclusive. We ...sought to investigate how SAVR affects vascular stiffness in the short and long term. Design and method: We included 55 patients (mean age 70 ± 8 years, 69% men) with severe symptomatic aortic stenosis who underwent SAVR. Arterial stiffness was assessed using the carotid-femoral pulse wave velocity (cfPWV) and brachial-ankle pulse wave velocity (baPWV). Measurements were conducted at baseline, in the acute phase, and 1 year after the operation. Results: Immediately after SAVR there was an increase in cfPWV (7.66 ± 1.63 m/s vs 8.27 ± 2.06 m/s, p = .010) that was sustained at 1 year (7.66 ± 1.63 m/s vs 8.98 ± 2.31 m/s, p = <.001, figure 1). Similarly, baPWV increased in the acute phase (1597 ± 455 cm/s vs 1954 ± 658 cm/s, p < .001) and persisted 1 year postoperatively (1597 ± 1833 cm/s, p < .001, figure 2). Conclusions: After SAVR the arterial system shows an increase of stiffness in response to the acute relief of the obstruction, which is retained in the long term.
Despite the increasing use of transcatheter aortic valve procedures, many patients still require surgical aortic valve replacement (SAVR). Assessing arterial properties in patients undergoing SAVR ...for aortic valve stenosis can be challenging, and the existing evidence is inconclusive. Our study aimed to investigate the impact of SAVR on vascular stiffness and the quality of life, as well as the different effects of valve type on arterial properties.
We included 60 patients (mean age 70.25 ± 8.76 years, 65% men) with severe symptomatic aortic stenosis who underwent SAVR. Arterial stiffness (cfPWV, baPWV) and vascular parameters (AIx@75, central pressures, SEVR) were measured at baseline, pre-discharge, and 1-year post-operation. The QOL was assessed using the generic questionnaire-short-form health survey 36 (SF-36) pre-operatively and at 1 year.
Post-SAVR, cfPWV increased immediately (7.67 ± 1.70 m/s vs. 8.27 ± 1.92 m/s,
= 0.009) and persisted at 1 year (8.27 ± 1.92 m/s vs. 9.29 ± 2.59 m/s,
≤ 0.001). Similarly, baPWV (n = 55) increased acutely (1633 ± 429 cm/s vs. 2014 ± 606 cm/s,
< 0.001) and remained elevated at 1 year (1633 ± 429 cm/s vs. 1867 ± 408 cm/s,
< 0.001). Acute decrease in Alx@75 (31.16 ± 10% vs. 22.48 ± 13%,
< 0.001) reversed at 1 year (31.16 ± 10% vs. 30.98 ± 9%,
= 0.71). SEVR improved (136.1 ± 30.4% vs. 149.2 ± 32.7%,
= 0.01) and persisted at 1 year (136.1 ± 30.4% vs. 147.5 ± 30.4%,
= 0.01). SV had a greater cfPWV increase at 1 year (
= 0.049). The QOL improved irrespective of arterial stiffness changes.
After SAVR, arterial stiffness demonstrates a persistent increase at 1-year, with valve type having a slight influence on the outcomes. These findings remain consistent despite the perceived QOL.
Aim
Thyroidectomy is the most common operation in the field of endocrine surgery. The aim of this study was to compare the use of LigaSure vessel (LS) and harmonic scalpel (HS) in 1653 total ...thyroidectomies between January 2008 and March of 2023, with regards to analysis of surgical bleeding complications duration the hospital stay and operative surgical time.
Methods
It is a retrospective analysis of a prospectively maintained database. Patients have been categorized into two groups:
Group A included 718 patients from January 2008 to May 2013 when LS was used, and the Group B included 935 patients from June 2013 to March 2023 when HS was used.
Results
From the total of 14 postoperative bleeding cases that occurred in patients of Group A, only in 4 of them it was necessary
to have a reoperation. The other 10 cases involved minor haemorrhages, while from the total of 6 postoperative bleeding cases that happened to patients of Group B, there were 4 cases that needed a reoperation (p-value >0.05) and 2 patients with minor haemorrhages. The postoperative evaluation of minor bleedings revealed statistically significant differences between the two groups (p-value < 0.05). The average hospital stay was similar in the two groups.
Conclusion
Both devices exhibit identical safety profiles in thyroidectomies specifically regarding major bleeding complications
that require reoperation. Additionally, HS was found to be more effective at achieving haemostasis, especially in the subgroup of patients with thyroid carcinoma. The results of the present study may be useful for high-volume centres performing numerous thyroidectomies every day.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Current treatment options for achalasia of the esophagus predominantly consist of endoscopic myotomy or laparoscopic myotomy combined with a partial fundoplication. The intraoperative use of ...conventional manometry has previously been proposed with various results. The aim of the present study was to introduce the use of high-resolution manometry (HRM) during surgical treatment for achalasia and to assess the long-term outcome of this technique.
We enrolled achalasia patients within the time period November 2013 to July 2016 who underwent HRM and evaluation of Eckardt scores (ES) before and after tailored laparoscopic myotomy and fundoplication with intraoperative recording using HRM.
Twenty patients were classified as having achalasia type I (20%), type II (55%), or type III (25%). During surgery, 9 myotomies were extended and 13 fundoplications were modified according to HRM findings. Mean resting (16.1 vs. 41.9 mmHg) and residual (9 vs. 28.7 mmHg) pressures of the lower esophageal sphincter and ES (0.7 vs. 6.9) were significantly eliminated postoperatively over a mean follow-up time of 17.7 months.
The use of intraoperative HRM gives us the advantage of simultaneous real-time estimation of intraluminal pressures of the esophagus and the ability to identify the exact points that produce pressure during laparoscopy. Consequently, it may be the key to the tailoring of the Heller-Dor technique and improving the outcomes for achalasia patients.
INTRODUCTION/OBJECTIVEThyroid carcinoma (TC) accounts for one percent of all carcinomas, with a higher incidence in women. Although there is controversy on the selection of the best surgical ...treatment for differentiated TC, total thyroidectomy (TT) and subtotal thyroidectomy (STT) are still the two main surgical procedures. The aim of the present study was to evaluate the early complication rates of thyroidectomy in patients undergoing thyroid surgery at a tertiary hospital in Greece. MethodsA total of 306 patients with differentiated TC who underwent thyroid surgery were enrolled retrospectively. Patients were divided into two groups. Group A included 214 patients undergoing TT, whereas 92 patients (group B) underwent STT. Demographic details of patients, operating time, and early complications (hypoparathyroidism, hematoma, infection, temporary recurrent laryngeal nerve palsy) were noted. ResultsThere was no significant difference in the sex, age, and mean operating time between the two groups (P=0.47, P=0.55, and P=0.09, respectively). Either hematoma or wound infection occurred in 3 (1.4%) or 4 (1.87%) of the patients undergoing TT compared to two (2.17%) or three (3.26%) of the patients undergoing STT (P=0.63 and P=0.46, respectively). In addition, either hypoparathyroidism or temporary recurrent laryngeal nerve palsy was observed in 34 (15.89%) or 13 (6.07%) of the patients undergoing TT compared with eleven (11.96%) or nine (9.78%) of the patients undergoing STT (P=0.37 and P=0.25, respectively). ConclusionsThe current study demonstrates that total thyroidectomy can be safely performed in patients with differentiated thyroid carcinoma without increasing the risk of early complications.
The relation among the various causal factors of obesity is not well understood, and there remains a lack of viable data to advance integrated, systems models of its etiology. The collection of big ...data has begun to allow the exploration of causal associations between behavior, built environment, and obesity-relevant health outcomes. Here, the traditional epidemiologic and emerging big data approaches used in obesity research are compared, describing the research questions, needs, and outcomes of 3 broad research domains: eating behavior, social food environments, and the built environment. Taking tangible steps at the intersection of these domains, the recent European Union project “BigO: Big data against childhood obesity” used a mobile health tool to link objective measurements of health, physical activity, and the built environment. BigO provided learning on the limitations of big data, such as privacy concerns, study sampling, and the balancing of epidemiologic domain expertise with the required technical expertise. Adopting big data approaches will facilitate the exploitation of data concerning obesity-relevant behaviors of a greater variety, which are also processed at speed, facilitated by mobile-based data collection and monitoring systems, citizen science, and artificial intelligence. These approaches will allow the field to expand from causal inference to more complex, systems-level predictive models, stimulating ambitious and effective policy interventions.
Teaser Text: Using large volumes and varieties of data—“big data”—can help to study the complex factors influencing obesity. This article explores the roles for big data in obesity research.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Being the second most common neurodegenerative disease, Parkinson's disease (PD) can be symptomatically treated, although, unfortunately, it cannot be cured yet. Moreover, diagnosing and assessing PD ...patients is a complex process, requiring continuous monitoring. In this vein, the design, development, and validation of innovative assessment tools may be helpful in the management of patients with PD, in particular. Based on intelligent ICT interventions, the i-PROGNOSIS project intends to mitigate PD's specific symptoms, such as neurological movement disorders of gait, balance, coordination, and posture, already characterized in the early phase of the disease. From this perspective, an innovative iPrognosis motor assessment tool is presented here, taking into consideration the Unified Parkinson Disease Rating Scale (UPDRS) Part III motor skills testing items, for evaluating the motor skills status. The efficiency of the proposed Assessment Tests to reflect the motor skills status, similarly to the UPDRS Part III items, was validated via 27 participants (18 males; mean age = 62 years, SD = 10.36 years; range, 43–79 years) with early (n = 10) and moderate (n = 17) PD who performed the Assessment Tests. Features from the latter were then correlated with the corresponding clinically assessed UPDRS Part III items, and statistically significant negative correlations (range, −0.364 to −0.802) were identified between the median values of the Assessment Tests and the UPDRS Part III items. In this vein, the iPrognosis Assessment Tests were integrated within the personalized interventions of the i-PROGNOSIS project, providing alternative means of assessing their effect on the PD patient's motor skills enhancement. The promising results presented here elaborate on the concept of using ICT-based assessment means to achieve comparable outcomes with the clinical standards in motor skills assessment.
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