Search Results (75)

Background and Objectives: Perineal wound complications and pelvic fluid collections or abscesses following proctectomy for Crohn’s disease are a common cause of morbidity and might be mitigated by filling the pelvis and occluding the pelvic inlet with a flap. Alternative flap options can be considered when inadequate omentum is available and when avoiding myofasciocutaneous flaps. Materials and Methods: A retrospective review of our Crohn’s proctectomy database was conducted to identify patients who underwent a non-omental or non-myofasciocutaneous local pedicle flap to their pelvis or pelvic exclusion using biological material during surgery. The techniques and outcomes of these alternative techniques are described in detail. Results: 228 patients underwent proctectomy for Crohn’s disease during the 10-year study period. However, only six patients had their pelvis filled or pelvic inlet occluded using a non-omental, non-myofasciocutaneous local pedicled flap or biological material. The techniques identified included two sigmoid mesocolic flaps, one peritoneal, preperitoneal fat and falciform ligament flap, one perivesical fat flap, one Gerota’s fat pad flap, and one bovine pericardial patch assisted pelvic exclusion. These flaps’ clinicopathological and operative characteristics, surgical outcomes, and technical aspects are described. Conclusions: When greater omentum is unavailable or inadequate and myofasciocutaneous flaps need to be avoided, local pedicled flaps using a range of intra-abdominal tissues or biological material can be used to fill the pelvis or occlude the pelvic inlet after proctectomy for Crohn’s disease. These techniques may help to prevent short and long-term complications associated with having a pelvic dead space. Full article

Introduction: Craniopharyngiomas are rare sellar embryonic malformational tumors of low-grade histological malignancy. Despite high overall survival rates (92%), quality of life is frequently reduced due to adverse late effects caused by hypothalamic obesity. It is well known that morbid hypothalamic obesity is associated with the grade of hypothalamic damage. Accordingly, craniopharyngioma should be considered a paradigmatic disease, reflecting challenges in the diagnosis and treatment of acquired hypothalamic obesity. Methods: A narrative review was performed after searching the MEDLINE/PubMed, Embase, and Web of Science databases for initial identifying articles. The search terms childhood-onset craniopharyngioma and hypothalamic obesity were used. Results: Despite the availability of promising therapeutic approaches, such as medication with central stimulating agents, antidiabetic drugs, glucagon-like peptide 1 (GLP1) receptor agonists, and Setmelanotide, it must be emphasized that there is currently no pharmaceutical treatment for hypothalamic obesity in craniopharyngioma proven to be effective in randomized controlled trials. For Setmelanotide, a prospective blinded randomized trial over a 12-month treatment period is ongoing. Bariatric interventions are effective, but non-reversible procedures such as bypass operations are controversial in the pediatric age group due to legal and ethical concerns. Recently, a treatment algorithm was introduced to improve the management of hypothalamic syndrome/obesity by offering more personalized treatment. Decisions on treatment strategies focusing on the preservation of visual, neuroendocrine, and hypothalamic integrity should be made by experienced multidisciplinary teams. Conclusions: Treatment approaches for hypothalamic obesity are limited. Further research on novel treatment approaches for hypothalamic obesity is warranted to improve the quality of life after childhood-onset craniopharyngioma. Full article

Companies operating in the energy market in Poland conduct business activity on the basis of special regulations applicable to this type of entity. However, they are, like any other entrepreneur, exposed to the risk of delays in payments, non-payment, restructuring, or even bankruptcy of their contractor. Appropriate instruments should be used to mitigate these risks. There are many methods available today to deal with trading risks. However, they should be tailored to the individual needs of each entrepreneur based on an in-depth analysis of its contractors. This article analyzes the five largest companies selling electricity in Poland in terms of the risk of late payments in the period 2018–2023. It turned out that in the surveyed companies in the period 2018–2013, the amount of receivables was constantly increasing, and the average recovery term was longer than the average payment term in enterprises in general. The real impact of delayed payments on the profitability of the surveyed companies was also calculated. Then, the available methods of transaction risk mitigation (tangible collateral, personal collateral, form of paying, other legal, banking and insurance instruments) were analyzed and described, and whether and to what extent they are used in the surveyed companies. The conducted research also allowed the author to conclude that, unfortunately, despite the existence of many instruments, they are not used due to the costs and formalities associated with their acquisition. Full article

Reproductive interactions between species could have negative effects on the fitness of the species involved, which can have important ecological and evolutionary consequences, such as population declines (including local extinction) or character divergence. Here, we report the courtship and attempted mating between two congeneric species of fireflies endemic to Mexico. The interactions involved males of the synchronous firefly Photinus palaciosi and females of the much larger, non-synchronous P. extensus. In the study site, the population density of P. palaciosi is much higher than that of P. extensus. Observations of marked P. extensus females throughout most of the mating season showed that 37.8% of their interactions with males were with P. palaciosi males. Although interspecific interactions were usually of shorter length, they frequently consumed a significant portion of the nightly mate-locating/courting period. These interspecific interactions are probably facilitated by the similarities in the mate location and courtship behavior of both species, which also share female brachyptery (elytra and wing reduction that makes females unable to fly). The simplest hypothesis to explain our behavioral observations is that P. palaciosi males mistakenly courted P. extensus females. The available evidence suggests that the operational sex ratio (OSR) of P. palaciosi is male-biased, as it seems to be the case in all synchronous fireflies studied to date. We hypothesize that the intense male competition for mates resulting from a male-biased OSR explains, at least in part, the “indiscriminate” sexual responses of P. palaciosi males. Another still not studied factor that could contribute to the frequent interspecific sexual interactions observed is the degree of similitude of the mating signals. The relatively high frequency of interspecific interactions and the significant amount of time invested in many of them (relative to the duration of the nightly mating period) indicate that the study of the potential fitness costs (and benefits?) of these interactions is a promising line of research. Full article

Pediatric cancers, while rare, pose unique challenges due to the heightened sensitivity of developing tissues and the increased risk of long-term radiation-induced effects. Radiotherapy (RT) is a cornerstone in pediatric oncology, but its application is limited by concerns about toxicity, particularly secondary malignancies, growth abnormalities, and cognitive deficits. CyberKnife (CK), an advanced robotic radiosurgery system, has emerged as a promising alternative due to its precision, non-invasiveness, and ability to deliver hypofractionated, high-dose RT while sparing healthy tissues. This narrative review explores the existing evidence on CK application in pediatric patients, synthesizing data from case reports, small series, and larger cohort studies. All the studies analyzed reported cases of tumors located in the skull or in the head and neck region. Findings suggest CK’s potential for effective tumor control with favorable toxicity profiles, especially for complex or inoperable tumors. However, the evidence remains limited, with the majority of studies involving small sample sizes and short follow-up periods. Moreover, concerns about the “dose-bath” effect and limited long-term data on stochastic risks warrant cautious adoption. Compared to Linac-based RT and proton therapy, CK offers unique advantages in reducing session numbers and enhancing patient comfort, while its real-time tracking provides superior accuracy. Despite these advantages, CK is associated with significant limitations, including a higher potential for low-dose scatter (often referred to as the “dose-bath” effect), extended treatment times in some protocols, and high costs requiring specialized expertise for operation. Emerging modalities like π radiotherapy further underscore the need for comparative studies to identify the optimal technique for specific pediatric cases. Notably, proton therapy remains the benchmark for minimizing long-term toxicity, but its cost and availability limit its accessibility. This review emphasizes the need for balanced evaluations of CK and highlights the importance of planning prospective studies and long-term follow-ups to refine its role in pediatric oncology. A recent German initiative to establish a CK registry for pediatric CNS lesions holds significant promise for advancing evidence-based applications and optimizing treatment strategies in this vulnerable population. Full article

Decarbonization of shipping is a legal obligation imposed by the International Maritime Organization (IMO). The ferry port and daily operations located near or in urban zones negatively impact the nearby environment. The electrification of ferries contributes to reducing the negative environmental impact. The available electrical infrastructure in ports often does not meet daily needs. The ferry fleet’s sailing schedule creates a non-periodic daily energy profile to determine the energy needs of the shore connection. The proposed research aims to optimize the daily electric ferry fleet peak charging power schedule process using particle swarm optimization and a greedy algorithm. A four-stage model has been proposed, consisting of the initialization of the ferry fleet’s daily energy profile, initial population generation with input constraints, optimization, and the creation of the modified daily energy load diagram. Robustness and validation of the proposed model were investigated and proven for energy profiles with and without optimization. For the proposed charging schedule, the study results show a reduction in peak power of 24%. By optimizing the charging process, peak charging power has been reduced without needing an additional energy storage system. Full article

Beyond portable mobile devices, lithium-ion batteries play a crucial role in electric vehicle operations and stationary grid power generation. However, the aging of lithium-ion batteries, often accelerated by extreme temperatures and load current influences, requires thorough examination and solution. The high load current, cycling, temperature differential, and operational conditions are factors contributing to the reduction in capacity and shortened lifespan of lithium-ion batteries. In this study, a lithium-ion (LiNi_xMn_yCo_zO₂) battery was modeled by using the MATLAB/Simulink model technique. In order to investigate the effect of resistance build-up in the batteries, the capacity of the batteries (old and new batteries) was analyzed over different usage periods: 360 cycles, 1000 cycles, and 2000 cycles. A cooling system was introduced to explicitly carry out an inductive analysis of the effect of temperature on the performances of the batteries. The effect of load current on the capacity of the battery was examined between 30 A and 100 A. The results showed that the available capacity of a battery is proportional to its usage rate. Generally, when the load current on the batteries (old and new batteries) was 30 A, the battery was ideally in good health even after 1000 cycles for a 2 h discharge time. In addition, the old battery, however, showed a capacity decrease to about 74.15% and 74.94% for scenarios 1 and 2 after 1000 cycles for a 2 h discharge time when the batteries were subjected to a 100 A discharge current. Amongst other factors, scenarios 1 and 2 can be differentiated by whether the battery pack discharges uniformly or non-uniformly, whether the individual cells operate under the same or different discharge cycles, and whether the batteries are with cooling or without a cooling system. The voltage and temperature differences between the old and new batteries, after 2000 cycles for the 100 A load current, are 4.0 V and 5.3 °C (scenario 2), respectively. Moreover, after 360 cycles at a 100 A discharge current, the temperature difference between the old and new batteries was 4.5 °C in scenario 1 and 2.3 °C in scenario 2. Based on the results obtained in this study, useful equations for proper calibration, voltage, and cooling switching time characteristics were proposed. Additionally, the study results indicated that at higher load currents, battery degradation became less affected by temperature differentials. The results of this study will aid in the adequate load optimization and thermal management of lithium-ion batteries for electric vehicle applications. Full article

In this paper, we investigate a rescheduling problem with rejection and an operator non-availability period on a single machine. An optimal original schedule with the objective of minimizing the total weighted completion time has been made in a deterministic production scheduling system without an unavailable interval. However, prior to the start of formal job processing, a time interval becomes unavailable due to the operator. No jobs can start or complete in the interval; nonetheless, a job that begins prior to this interval and finishes afterward is possible (if there is such a job, we call it a crossover job). In order to deal with the operator non-availability period, job rejection is allowed. Each job is either accepted for processing or rejected by paying a rejection cost. The planned original schedule is required to be rescheduled. The objective is to minimize the total weighted completion time of the accepted jobs plus the total penalty of the rejected jobs plus the weighted maximum tardiness penalty between the original schedule and the new reschedule. We present a pseudo-polynomial time dynamic programming exact algorithm and subsequently develop it into a fully polynomial time approximation scheme. Full article

In response to the SARS-CoV-2 pandemic, the United States declared a state of emergency and implemented large-scale shutdowns and public health initiatives to prevent overwhelming public resources. The success of these prevention methods remains unresolved as restrictions and implementation varied from national, state, and local levels. Despite national and local regulations, individual adherence to preventative guidelines presented an additional layer of variability. Cases of COVID-19 continued to rise and fall over a two-year period on a national level, despite masking recommendations, ease of testing, and availability of vaccines. The Ysleta del Sur Pueblo is a Native American tribal community and sovereign nation located in El Paso, Texas. Speaking Rock Entertainment Center is a major business operated by the tribe, employing many tribal and non-tribal members from the El Paso area. Following nationwide re-openings of non-essential businesses, Speaking Rock implemented an infection control program with strict adherence to recommendations provided by the Center for Disease Control and Prevention (CDC) and additional disease control. This response would result in a fully vaccinated workforce within the wider community of El Paso, where the vaccination rate was less than 80%. Herein, we examine the efficacy of these measures and report on the success of the program resulting in zero hospitalizations or deaths compared with rates of 1 in 250 and 1 in 40, respectively, in the surrounding community. Full article

Background: Balloon aortic valvuloplasty (BAV) is currently used as pre-treatment for patients undergoing trans-catheter aortic valve replacement (TAVR) as well as a stand-alone option for subjects with significant contraindications to TAVR. Mammoth is a newly available non-compliant balloon catheter (BC) included in the balloon-expandable Myval THV system (Meril Life Sciences Pvt. Ltd., India). As limited data on the performance of this BC are available, we here report the results following its use for BAV as pre-dilatation during TAVR or as a stand-alone procedure. Methods: A retrospective, single-center cohort analysis was performed on patients with severe aortic valve stenosis (AS) treated with the Mammoth BC at IRCCS Ospedale Galeazzi Sant’Ambrogio, Milan, Italy. The primary endpoint was technical success defined as successful Mammoth BC advancement across the AS followed by its full and homogeneous inflation without major complications such as aortic root/left ventricular outflow tract injury and/or stroke. Results: A total of 121 patients were treated by BAV with Mammoth BC during the study period. Among these, 105 patients underwent BAV pre-dilatation before TAVR while 16 patients underwent a stand-alone BAV procedure. Mammoth BC was delivered and successfully inflated at the target site in all of the 121 cases without BC-related complications (100% technical success). However, in the BAV “stand-alone group”, three patients required two different balloon sizes while in nine patients multiple rounds (two to three) of balloon inflation were needed to significantly lower the transvalvular gradient. No cases of aortic root injury or massive aortic regurgitation due to Mammoth BC-related aortic leaflet injury were reported while one major stroke occurred late after TAVR. No intra-procedural deaths occurred nor bleeding (BARC 3-4) or major vascular complication. Conclusions: Mammoth BC use in patients with severe AS proved safe and effective, either before TAVR or as a stand-alone procedure, expanding the range of available tools for structural operators. Full article

Load balancing between required power demand and the available generation capacity is the main task of demand response for a smart grid. Matching between the objectives of users and utilities is the main gap that should be addressed in the demand response context. In this paper, a multi-user optimal load scheduling is proposed to benefit both utility companies and users. Different objectives are considered to form a multi-objective artificial hummingbird algorithm (MAHA). The cost of energy consumption, peak of load, and user inconvenience are the main objectives considered in this work. A hybrid multi-criteria decision making method is considered to select the dominance solutions. This approach is based on the removal effects of criteria (MERECs) and is utilized for deriving appropriate weights of various criteria. Next, the Vlse Kriterijumska Optimizacija Kompromisno Resenje (VIKOR) method is used to find the best solution of load scheduling from a set of Pareto front solutions produced by MAHA. Multiple pricing schemes are applied in this work, namely the time of use (ToU) and adaptive consumption level pricing scheme (ACLPS), to test the proposed system with regards to different pricing rates. Furthermore, non-cooperative and cooperative users’ working schemes are considered to overcome the issue of making a new peak load time through shifting the user load from the peak to off-peak period to realize minimum energy cost. The results demonstrate 81% cost savings for the proposed method with the cooperative mode while using ACLPS and 40% savings regarding ToU. Furthermore, the peak saving for the same mode of operation provides about 68% and 64% for ACLPs and ToU, respectively. The finding of this work has been validated against other related contributions to examine the significance of the proposed technique. The analyses in this research have concluded that the presented approach has realized a remarkable saving for the peak power intervals and energy cost while maintaining an acceptable range of the customer inconvenience level. Full article

Background/Objectives: Contrast-induced acute kidney injury (AKI) is associated with early mortality and adverse events. However, in the setting of transcatheter aortic valve implantation (TAVI), previous literature has failed to establish a correlation between the absolute volume of contrast media administered and mortality. We aimed to investigate the impact of contrast volume administered normalised to estimated glomerular filtration rate (CV/eGFR) on the development of AKI and on 30-day all-cause mortality in TAVI patients. Methods: We retrospectively analysed a cohort of 1150 patients who underwent TAVI at our unit between 2015 and 2018. Results: Follow-up was complete for 1064 patients. There were 23 deaths within the follow-up period and 76 cases of AKI, 9 of which required new renal replacement therapy (RRT). Receiver-operating characteristic (ROC) curve analysis showed fair discrimination for 30-day all-cause mortality at a CV/eGFR ratio of 3.6 (area under the ROC curve (AUC) 0.671). Of patients in whom CV data were available, 86.0% (n = 757) had a CV/eGFR < 3.6 and 14.0% (n = 123) had a CV/eGFR ≥ 3.6. In multivariate logistic regression analysis, CV/eGFR ≥ 3.6 was the strongest predictor of 30-day all-cause mortality (odds ratio 5.06, 95% confidence interval [1.61–15.7], p = 0.004). Other independent predictors were procedural urgency (3.28 [1.04–10.3], p = 0.038) and being under general anaesthesia (4.81 [1.10–17.3], p = 0.023). CV/eGFR ≥ 3.6 was also independently associated with significantly increased odds of AKI (2.28 [1.20–4.17], p = 0.009) alongside significant non-left main stem coronary artery disease (2.56 [1.45–4.66], p = 0.001), and diabetes (1.82 [1.03–3.19], p = 0.037). In supplementary ROC curve analysis, a similar CV/eGFR cut point of 3.6 was found to be an excellent predictor for new RRT (AUC 0.833). Conclusions: In conclusion, a CV/eGFR ≥ 3.6 post-TAVI was found to be a strong predictor of 30-day mortality and AKI. The maximum contrast volume that can be safely administered in each patient without significantly increasing the risk of mortality and AKI can be calculated using this ratio. Full article

The equatorial post-sunset ionospheric irregularities induce rapid fluctuations in the phase and amplitude of global navigation satellite system (GNSS) signals which may lead to the loss of lock and can potentially degrade the position accuracy. This study presents a new analysis of L-band scintillation from a low latitude station at Guntur (Geographic 16.44°N, 80.62°E, dip 22.18°), India, for the period of 18 months from August 2021 to January 2023. The observations are categorized either in the medium Earth-orbiting (MEO) or geosynchronous orbiting (GSO) satellites (GSO is considered as a set of the geostationary and inclined geosynchronous satellites) for L1, L2, and L5 signals. The results show a higher occurrence of moderate (0.5 < S4 ≤ 0.8) and strong (S4 > 0.8) scintillations on different signals from the MEO compared to the GSO satellites. Statistically, the average of peak S4 values provides a higher confidence in the severity of scintillations on a given night, which is found to be in-line with the scintillation occurrences. The percentage occurrence of scintillation-affected satellites is found to be higher on L1 compared to other signals, wherein a contrasting higher percentage of affected satellites over GSO than MEO is observed. While a clear demarcation between the L2/L5 signals and L1 is found over the MEO, in the case of GSO, the CCDF over L5 is found to match mostly with the L1 signal. This could possibly originate from the space diversity gain effect known to impact the closely spaced geostationary satellite links. Another major difference of higher slopes and less scatter of S4 values corresponding to L1 versus L2/L5 from the GSO satellite is found compared to mostly non-linear highly scattered relations from the MEO. The distribution of the percentage of scintillation-affected satellites on L1 shows a close match between MEO and GSO in a total number of minutes up to ~60%. However, such a number of minutes corresponding to higher than 60% is found to be larger for GSO. Thus, the results indicate the possibility of homogeneous spatial patterns in a scintillation distribution over a low latitude site, which could originate from the closely spaced GSO links and highlight the role of the number of available satellites with the geometry of the links, being the deciding factors. This helps the ionospheric community to develop inter-GNSS (MEO and GSO) operability models for achieving highly accurate positioning solutions during adverse ionospheric weather conditions. Full article

With the development of smart grids and new power systems, the combination of non-intrusive load identification technology and smart home technology can provide users with the operating conditions of home appliances and equipment, thus reducing home energy loss and improving users’ ability to demand a response. This paper proposes a non-intrusive load decomposition model with a parallel multiscale attention mechanism (PMAM). The model can extract both local and global feature information and fuse it through a parallel multiscale network. This improves the attention mechanism’s ability to capture feature information over long time periods. To validate the model’s decomposition ability, we combined the PMAM model with four benchmark models: the Long Short-Term Memory (LSTM) recurrent neural network model, the Time Pooling-based Load Disaggregation Model (TPNILM), the Extreme Learning Machine (ELM), and the Load Disaggregation Model without Parallel Multi-scalar Attention Mechanisms (UNPMAM). The model was trained on the publicly available UK-DALE dataset and tested. The models’ test results were quantitatively evaluated using a confusion matrix. This involved calculating the F1 score of the load decomposition. A higher F1 score indicates better model decomposition performance. The results indicate that the PMAM model proposed in this paper maintains an F1 score above 0.9 for the decomposition of three types of electrical equipment under the same household user, which is 3% higher than that of the other benchmark models on average. In the cross-household test, the PMAM also demonstrated a better decomposition ability, with the F1 score maintained above 0.85, and the mean absolute error (MAE) decreased by 5.3% on average compared with that of the UNPMAM. Full article

Currently, double-hole complementary ventilation is a mature ventilation method for operating tunnels, but how to carry out it in the construction tunnel poses a new challenge. Due to the desynchronization in the construction period of the double-hole tunnel, there is an instantaneous difference in the air flow demand between the two working faces. The study analyzes the impact of geometric parameters, specifically L_t (the distance from the traffic cross passage to the working face of the advance side tunnel), L_p (the distance between the pedestrian cross passage and the working face of the advance side tunnel), H_t (height of the upper step), and L_w (safe step distance of the double-hole working face) on ventilation network stability. The results show that with the increase of L_t and L_p, the R_m resistance of each branch changes non-uniformly, and the stability of the ventilation network is significantly different. Then, when L_t, L_p = 80 and 180 m, the air flow directions of the double-hole tunnel are the same. Finally, when L_t and L_p = 130 m, the air flow directions are inconsistent, which indicates that in the range of 80 m < L_t or L_p < 180 m, the cross-section size of the cross passage affects the stability of the ventilation network. However, when 2.5 m < H_t < 3 m, or 30 m < L_w < 50 m, the stability of the ventilation network is not affected, and the flow field of the double-holes does not interfere with each other. The conclusions obtained confirm that the double-hole complementary ventilation method is available in construction tunnels, and has potential for implementation. Full article