Search Results (24)

Isolated Locoregionally Recurrent Pancreatic Adenocarcinoma (ILRPA) accounts for 25–30% of recurrences after radical resection, yet the role of salvage radiation (RT) in this setting remains controversial due to limited data. We aimed to evaluate the impact of salvage RT on survival outcomes compared with non-salvage RT in patients with ILRPA. We retrospectively analyzed data of patients with ILRPA post-radical resection treated at our centre between 2012 and 2021. Patients were categorized into two cohorts based on whether salvage RT was administered post-recurrence. Patients who received a minimum of 30 Gy in 10 fractions (BED₁₀ ≥ 39 Gy) were included for analysis. The clinical characteristics, treatments, and outcomes were analyzed. The chi-square or Fisher’s exact test for categorical variables and Student’s t-test or Wilcoxon rank sum test for continuous variables were utilized for comparisons. The Kaplan–Meier method and log-rank test were performed to compare overall survival (OS) and progression-free survival (PFS) between the two groups. OS and PFS were calculated from the time of locoregional recurrence until event or loss of follow-up. Thirty-two patients were identified, with sixteen patients in each group. The patients and tumour characteristics were balanced between the two cohorts, except for chemotherapy, where the salvage RT group tended to receive palliative chemotherapy more than the non-salvage group (p = 0.007). The median radiotherapy dose received for the salvage RT cohort was 50.4 Gy (BED₁₀ = 59.5 Gy). Chemotherapy was restarted in 75% either before, after, or during radiation, and only in 31.25% of patients in the non-salvage group (p = 0.013). Patients who received salvage RT had statistically significantly better median OS and PFS than those who did not (25.2 vs. 8.4 months, p = 0.0006, HR 0.25, 95% CI (0.11–0.59)), (15.6 vs. 7.2 months, p = 0.0006, HR 0.26, 95% CI (0.11–0.58), respectively). Ten patients (62.5%) developed distant metastases (DM) at least 3 months post-recurrence in the salvage RT cohort compared to five patients (31.25%) in the non-salvage RT cohort (p = 0.08). In the salvage RT group, 10/16 patients (62.5%) maintained locoregional disease control post-RT. Salvage RT was associated with better OS and PFS in patients with ILRPA, highlighting its potential as an essential treatment modality. While salvage RT appears beneficial, confounding factors like chemotherapy disparities between groups necessitate further investigation in prospective cohorts. Full article

Waste management in the agri-food industry is an important technological and environmental problem. Slaughterhouse waste is particularly problematic, as it contains significant amounts of proteins and lipids, neither of which constitute a good substrate for methane production. The physical properties of mixtures of fat and polar solvents inhibit the methanogenesis process. The aim of this research was to assess the impact of the addition of fat emulsifiers and biochar on the amount of biogas produced and the level of carbon conversion per unit of waste weight. The assumed goal was achieved based on a laboratory experiment using static methane fermentation, carried out in accordance with the methodology of the DIN 38414/S8 standard. The results of the experiment indicate that the addition of fat emulsifiers increased the biogas yield from slaughterhouse waste from approximately 370 to 430 dm³ per 2 kg dry weight of waste. Each technological variant resulted in an increase in the amount of carbon that was transformed in the methanogenesis process. Although the level of carbon transformation in the methanogenesis process increased by approximately 20% in objects with emulsifier addition, the use of biochar and fat emulsifiers did not change the amount of methane production. Within the assumed system limits, therefore, the use of fat emulsifiers and biochar seems to be pointless. However, the use of the developed technology can improve the efficiency of biogas production by up to 18% and shorten the process by 5 days. Assuming the continuous operation of the biogas plant, the use of the developed technology will increase the efficiency of biogas production from slaughterhouse waste in the long term by over 30% without the need to modify the infrastructure in the biogas plant. Full article

The purpose of this study is to determine if forged TiAl alloys are worth using for small parts such as jet engine turbine blades. As part of this goal, this study investigated ways to improve the impact resistance of forged TiAl alloys and compared them to cast TiAl alloys. The effects of additive elements and microstructure on the impact resistance of forged ternary TiAl alloys of 43.5 at. % Al were evaluated using the Charpy impact test on specimens heated to 500 °C prior to testing. The impact resistance of the forged alloys improved with the addition of Cr, V, and Mn and deteriorated with the addition of Nb. The impact resistance of the microstructure containing a β-phase, a common microstructure in forged TiAl alloys, was significantly lower. The fully lamellar structure obtained at the expense of forgeability showed much higher impact resistance than this. However, even the best impact resistance of the forged alloys was significantly inferior to that of cast ternary alloys of 46.5 at. % Al prepared with the same additive content. Combined with the high cost and low high-temperature strength of the forged TiAl alloys, it is concluded that it is pointless to use forged TiAl alloys for small parts that can be made via casting. Full article

Magnetic resonance angiography is a medical procedure used to offer an image of the blood vessels and organs of the body. Given the worldwide spread of cardiovascular diseases, more and more resources are invested in treating them. One of the most modern treatments involves the acquisition of images of the heart. Sometimes the contrast of these images is not satisfactory. Injecting invasive enhancement substances to obtain a better view of the cardiac route is not advisable. However, software algorithms can solve the problem. This study proposes and tests a local adaptive contrast-adjustment algorithm using the dual-tree complex wavelet transform. The method has been tested with medical data from a public database to allow comparisons to other methods. The selected algorithm further improved the contrast of images. The performances are given for evaluation, both visually (to help doctors make accurate diagnoses) and in parametric form (to show engineers which parts of the algorithm might need improvement). Compared to other contrast enhancement methods, the proposed wavelet algorithm shows good results and greater stability. Thus, we aim to avoid future pointless complications due to unnecessary contrast substances. Full article

A lack of aggregate analysis concerning energy communities exists in the academic literature. The authors utilized a combination of literature reviews and desk research to fill this gap. The existing debate on the classification of energy communities was summarized and aligned. Discovered classifications were used to analyze the status quo of the sector. The authors found nearly 4000 energy communities with 900,000 members in the European Union. On average, there are 844 members per one energy community. Germany, the Netherlands, Denmark, and the United Kingdom are at the forefront of the movement. Different countries have different primary sources of renewable energy utilized by energy communities, and membership structures vary based on the energy source and corporate purpose of the energy community together with the sector’s maturity in a certain country. Predominantly, hydro and biomass are used by energy communities in Alpine countries, solar energy is used in Germany, Spain, and France, wind in the Netherlands and Denmark, and different renewables in the United Kingdom. More members have joined the hydro, biomass, and wind communities than solar communities. Each country has national and regional associations of energy communities. In addition, intermediary actors, researchers, and consultancy agencies have shown a growing interest in the deployment of the movement. Achieving a conformity of business models Europe-wide would probably be impossible and pointless. Distinct geographical, institutional, and policy context-specific conditions stimulate diversity rather than conformity. Full article

The objective of the present study was to explore three types of vibro-compacted precast concrete mixtures replacing fine and coarse gravel with a recycled/mixed concrete aggregate (RCA or MCA). The portlandite phase found in RCA and MCA by XRD is a “potential” CO₂ sink. CO₂ curing improved the compressive strength in all the mixtures studied. One tonne of the mixtures studied could be decarbonised after only 7 days of curing 13,604, 36,077 and 24,635 m³ of air using natural aggregates, RCA or MCA, respectively. The compressive strength obtained, XRD, TGA/DTA and carbon emission evaluation showed that curing longer than 7 days in CO₂ was pointless. The total CO₂ emissions by a mixture using CO₂ curing at 7 days were 221.26, 204.38 and 210.05 kg CO₂ eq/m³ air using natural aggregates, RCA or MCA, respectively. The findings of this study provide a valuable contribution to carbon emission evaluation of CO₂ curing in vibro-compacted precast concrete with recycled/mixed concrete aggregates (RCA or MCA). The technology proposed in this research facilitates carbon capture and use and guarantees enhanced compressive strength of the concrete samples. Full article

Indeterminate thyroid nodules (ITN) are commonly encountered among the general population, with a malignancy rate of 10 to 40%. However, many patients may be overtreated with futile surgery for benign ITN. To avoid unnecessary surgery, PET/CT scan is a possible alternative to help differentiate between benign and malignant ITN. In this narrative review, the major results and limitations of the most recent studies on PET/CT efficacy (from PET/CT visual assessment to quantitative PET parameters and recent radiomic features analysis) and on cost-effectiveness (compared to other alternatives (such as surgery)) are presented. PET/CT can reduce futile surgery with visual assessment (around 40%; if ITN ≥ 10 mm). Moreover, PET/CT conventional parameters and radiomic features extracted from PET/CT imaging can be associated together in a predictive model to rule out malignancy in ITN, with a high NPV (96%) when certain criteria are met. Even though promising results were obtained in these recent PET/CT studies, further studies are needed to enable PET/CT to become the definitive diagnostic tool once a thyroid nodule is identified as indeterminate. Full article

A large number of researchers spend a lot of time searching for the most efficient neural network to solve a given problem. The procedure of configuration, training, testing, and comparison for expected performance is applied to each experimental neural network. The configuration parameters—training methods, transfer functions, number of hidden layers, number of neurons, number of epochs, and tolerable error—have multiple possible values. Setting guidelines for appropriate parameter values would shorten the time required to create an efficient neural network, facilitate researchers, and provide a tool to improve the performance of automated neural network search methods. The task considered in this paper is related to the determination of upper bounds for the number of hidden layers and the number of neurons in them for approximating artificial neural networks trained with algorithms using the Jacobi matrix in the error function. The derived formulas for the upper limits of the number of hidden layers and the number of neurons in them are proved theoretically, and the presented experiments confirm their validity. They show that the search for an efficient neural network can focus below certain upper bounds, and above them, it becomes pointless. The formulas provide researchers with a useful auxiliary tool in the search for efficient neural networks with optimal topology. They are applicable to neural networks trained with methods such as Levenberg–Marquardt, Gauss–Newton, Bayesian regularization, scaled conjugate gradient, BFGS quasi-Newton, etc., which use the Jacobi matrix. Full article

This paper provides an analysis of James Sterba’s argument from evil in the world and the author’s Thomistic counterargument. Many authors of contemporary analytic philosophy of religion discuss the concept of “horrendous evils”, which is a representative name for pointless evil and suffering in the world. Sterba claims that the existence of such evil is not logically compatible with the existence of the all-good theistic God. If such a God existed, according to Sterba, he would have intervened in time and prevented and not permitted horrendous evil consequences; in other words, he would have acted as an ideal state. The author of this paper argues that the analogy of an ideal state does not disprove the existence of God of theism. Furthermore, people would prefer if God was not like an ideal state. Applying the characteristics of an ideal state to a theistic God is not reasonable because it relies on anthropomorphism. Such anthropomorphism is incoherent with some basic theistic beliefs. The author of this paper applies Thomistic concepts to the problem of horrendous evils. Full article

We address the question of how organizations’ practices of social responsibility impact their employees’ job performance. Independent studies have shown that job performance is influenced by how employees perceive the organization they work for and how they perceive the work they perform for the organization. Moreover, studies on the relationship between social responsibility and job performance have shown that employees’ perceptions of their organization mediate the relationship. What is thus far neglected, however, is whether and how their perceptions of work itself mediate the relationship as well. We derive a sequential mediation model according to which social responsibility improves job performance by contributing to a supportive and trustworthy work context (employees’ perceptions of the organization they work for), in turn promoting work meaningfulness and engagement (employees’ perceptions of work itself). We collect survey data and test the sequential mediation model against a series of alternative models, each of which challenges a specific assumption of the proposed model. Our model provides the best tradeoff between the accuracy and the parsimony with which it describes the data collected, and is, therefore, expected to generalize best to other data. Full article

Paddy is an artificial ecosystem driven by human activities, such as adjustment of cropping systems, deployment of resistant varieties and pesticides use. Inappropriate human intervention aggravated the disruption of ecosystems, which resulted in rice viral disease epidemics characterized by fulminant, migrating and intermittent outbreaks. Rice stripe disease (RSD), lasting for over 10 years from 2000, was modeled for exploring better management strategies of plant viral disease transmitted by insect vectors. In eight counties of Jiangsu province, China, the biotic, abiotic and human factors between 2000 and 2012 were monitored to determine key factors of human activities related to RSD epidemics. RSD severity was significantly related to resistance, the interval of wheat harvest and rice sowing (WHRS) and inconsecutive interval of wheat sowing and rice harvest (WSRH). The relationship between human activities and the small brown planthopper (SBPH) showed that the resistance was more significantly associated with SBPH viruliferous rate in the preceding year than that of the current year but not correlated with SBPH density. Resistance could impact the SBPH viruliferous rate in the preceding year indirectly through transmission probability and, thereafter, the continuing disease epidemics. The insignificant interactive effects among resistance, WHRS and WSRH on disease severity meant that these three factors could be taken into consideration separately in agricultural practice according to rice chronological order. The quantitative field study conducted in Jiangsu province presented a good example of plant viral disease management, guided by which could not only avoid pointless actions but, most importantly, generate more efficient and economic returns. Therefore, in order to improve the management of RSD, it should focus on the adjustment of these human factors independently and sequentially in combination with the forecast of RSD. Full article

On 1 August 2020, South Africa’s Minister of Health announced that more than half of a million coronavirus cases were confirmed in the country. South Africa was by far the hardest-hit country in Africa, accounting for half of all infections reported across the continent. The prevalence of underlying conditions such as fever and blood oxygen saturation (SpO2) has been known known to be a significant determinant in the hospitalisation of COVID-19 patients. Low oxygen saturation on admission was reported as a strong predictor of in-hospital mortality in COVID-19 patients. The study sought to assess the association between body temperature and other clinical risk factors with low SpO2 among COVID-19 inpatient case fatalities. A quantitative retrospective study was carried out in Limpopo Province, employing secondary data from the Limpopo Department of Health (LDoH) on COVID-19 inpatients case fatalities across all districts in the province. The chi-square test and Pearson’s correlation coefficient were used to assess the relationship between body temperature and clinical risk factors with SpO2 levels. The findings of this paper indicated that age (older age), chills, sore throat, anosmia, dysgeusia, myalgia/body aches, diarrhoea and HIV/AIDS were associated with low SpO2 in-hospital mortality in COVID-19 patients. Nasal prongs and a face mask with a reservoir for respiratory support cannula were commonly used patient interfaces to provide supplemental oxygen, with the use of only a high-flow nasal cannula (HFNC) being minimal (7%). The majority of COVID-19 inpatient fatalities had normal body temperature (<38 °C) and SpO2, with no correlation between the two variables. Considering temperature screening as a possible strategy to combat the spread of COVID-19 or suspicious COVID-19 cases appeared, then, to be a pointless exercise. This study aimed to recommend new clinical criteria for detecting COVID-19 cases. Full article

For the last few decades, medical guidelines have recommended treating patients with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) with graded exercise therapy (GET) and cognitive behavioural therapy (CBT). Moreover, doctors have questioned the recovery behaviour of these patients and stimulated them to follow these treatments so that they would be able to go back to work. In this article, we reviewed trials of GET and CBT for ME/CFS that reported on work status before and after treatment to answer the question of whether doctors should continue to question the recovery behaviour of patients with ME/CFS. Our review shows that more patients are unable to work after treatment than before treatment with CBT and GET. It also highlights the fact that both treatments are unsafe for patients with ME/CFS. Therefore, questioning the recovery behaviour of patients with ME/CFS is pointless. This confirms the conclusion from the British National Institute for Health and Care Excellence (NICE), which has recently published its updated ME/CFS guideline and concluded that CBT and GET are not effective and do not lead to recovery. Studies on CBT and GET for long COVID have not yet been published. However, this review offers no support for their use in improving the recovery of patients with an ME/CFS-like illness after infection with COVID-19, nor does it lend any support to the practice of questioning the recovery behaviour of these patients. Full article

The use of artificial intelligence (AI) systems in biomedical and clinical settings can disrupt the traditional doctor–patient relationship, which is based on trust and transparency in medical advice and therapeutic decisions. When the diagnosis or selection of a therapy is no longer made solely by the physician, but to a significant extent by a machine using algorithms, decisions become nontransparent. Skill learning is the most common application of machine learning algorithms in clinical decision making. These are a class of very general algorithms (artificial neural networks, classifiers, etc.), which are tuned based on examples to optimize the classification of new, unseen cases. It is pointless to ask for an explanation for a decision. A detailed understanding of the mathematical details of an AI algorithm may be possible for experts in statistics or computer science. However, when it comes to the fate of human beings, this “developer’s explanation” is not sufficient. The concept of explainable AI (XAI) as a solution to this problem is attracting increasing scientific and regulatory interest. This review focuses on the requirement that XAIs must be able to explain in detail the decisions made by the AI to the experts in the field. Full article

Assisted reproductive techniques in cattle, such as artificial insemination (AI) and embryo transfer (ET), are widely used. Despite many years of methodological improvements, the pregnancy rate (PR) in cows has not increased in direct proportion with their development. Among the possibilities to increase the PR is the use of certain steroids and nonsteroidal anti-inflammatory drugs (NSAIDs). The antiluteolytic effect of NSAIDs is achieved by blocking cyclooxygenase, which is involved in the conversion of arachidonic acid to prostaglandins. This article compares the PRs obtained after treatment with the commonly used NSAIDs in cattle, including flunixin meglumine, carprofen, meloxicam, ibuprofen, aspirin, and sildenafil. Studies on the effectiveness of certain steroid drugs on the PR have also been described. The results were not always consistent, and so comparisons between studies were made. In conclusion, flunixin meglumine seems to be an option, and can be recommended for improving ET results, especially in situations of high exposure or susceptibility to stress. Its administration under all circumstances, however, might be pointless and will not lead to the desired effect. Full article