Search Results (18,693)

Type IV gas cylinders are widely used in the field of vehicles due to their advantages such as light weight, cleanliness, and low cost. Ramie fiber/degradable epoxy resin composites (RFRDE) provide new ideas for the material selection of Type IV gas cylinders due to their advantages of low carbon emissions, low environmental pollution, and renewable resource utilization. However, the poor interfacial bonding strength and moisture resistance between polyethylene plastics and RFRDE have limited their application areas. This study tested the mechanical properties of ramie fibers at different heat treatment temperatures, and studied the thermal mechanical properties of RFRDE through differential scanning calorimeter and curing kinetics methods. At 180 °C, the tensile strength of fiber bundles decreased by 34% compared to untreated fibers. As the highest curing temperature decreases, the tensile strength of RFRDE increases but the curing degree decreases. At the highest curing temperature of 100 °C, the tensile strength of RFRDE is 296 MPa. The effect of the corona discharge and flexible adhesive on the surface modification of polyethylene was analyzed using scanning electron microscopy. These results provide guidance for the development of natural fiber/degradable epoxy resin composite materials. Full article

Recent studies have revealed that the frequency and magnitude of floods tend to increase due to climate change. Hence, excessive scouring due to flood events puts river bridges at greater risk of failure. This paper presents the initial findings of an experimental study to improve the understanding of the main characteristics of bridge pier scour under pressurized flow encountered during flooding. The experiments were carried out in four main groups according to two deck alignments with circular and oblong pier shapes. For each group of experiments, thirty-six tests were conducted under partially and fully pressurized flow conditions using four approach flow depths and three discharge values. The validity of the structured design approach for pier scour estimation implemented in the guidelines was investigated. The results showed that the bridge pier scour depths were up to 29.4% and 49.4% greater than the sum of the vertical contraction and local scour depths for 100 L/s for partially and fully pressurized flow conditions, respectively. However, as the discharge increased to 120 L/s, the bridge pier scour depth became 38.3% and 17.8% smaller than the sum of the vertical contraction and local scour depths for partially and fully pressurized flow, respectively. So, the structured design approach was determined to be safe for high discharge values. Furthermore, it was found that tests with a circular pier resulted in higher bridge pier scour depths than the sum of the vertical contraction and local scour depths up to 19.3% even for 120 L/s. Conversely, smaller bridge pier scour depths than the sum of the vertical contraction and local scour depths were observed up to 17.8% for tests with oblong piers. Thus, it can be concluded that the pier shape has a profound effect on scour holes and oblong piers cause smaller scour depths than circular piers in pressurized flow conditions. This study showed that the flow–pier–deck interaction significantly affects the depth and width of the scour hole, especially for small discharges and fully pressurized flow conditions. Full article

Comprehensively clarifying the influencing factors of carbon emissions is crucial to realizing carbon emission reduction targets in China. To address this issue, this paper develops a four-level carbon emission influencing factor system from six perspectives: population, economy, energy, water resources, main pollutants, and afforestation. To analyze how these factors affect carbon emissions, we propose an improved partial least squares structural equation model (PLS-SEM) based on a random forest (RF), named RF-PLS-SEM. In addition, the entropy weight method (EWM) is employed to evaluate the low-carbon development level according to the results of the RF-PLS-SEM. This paper takes Shandong Province as an example for empirical analysis. The results demonstrate that the improved model significantly improves accuracy from 0.8141 to 0.9220. Moreover, water resources and afforestation have relatively small impacts on carbon emissions. Primary and tertiary industries are negative influencing factors that inhibit the growth of carbon emissions, whereas total energy consumption, the volume of wastewater discharged and of common industrial solid waste are positive and direct influencing factors, and population density is indirect. In particular, this paper explores the important role of fisheries in reducing carbon emissions and discusses the relationship between population aging and carbon emissions. In terms of the level of low-carbon development, the assessment system of carbon emission is constructed from four dimensions, namely, population, economy, energy, and main pollutants, showing weak, basic, and sustainable stages of low-carbon development during the 1997–2012, 2013–2020, and 2021–2022 periods, respectively. Full article

Both nanoscience and nanotechnology have undoubtedly contributed significantly to the development of thermite-based nanoenergetic materials (NEMs) with tunable and tailorable combustion performance and their subsequent integration into devices. Specifically, this review article reflects the immense paybacks in designing and fabricating ordered/disordered assembly of energetic materials over multiple length scales (from nano- to milli-scales) in terms of realization of desired reaction rates and sensitivity. Besides presenting a critical review of present advancements made in the synthesis of NEMs, this article touches upon aspects related to various applications concomitantly. The article concludes with the author’s summary of the insurmountable challenges and the road ahead toward the deployment of nanoenergetic materials in practical applications. The real challenge lies in the ability to preserve the self-assembly of fuel and oxidizer nanoparticles achieved at the nanoscale while synthesizing macroscale energetic formulations using advanced fabrication techniques both in bulk and thin film forms. Most importantly, these self-assembled NEMs have to exhibit excellent combustion performance at reduced sensitivity to external stimuli such as electrostatic discharge (ESD), friction and impact. Full article

In this manuscript, we report on the synthesis of a polynitrogen material from a potassium azide precursor using nanosecond-pulsed spark discharge plasma in liquid nitrogen. The polynitrogen material was characterized using Raman and Fourier transform infrared (FTIR) spectroscopy and identified as K₂N₆, with planar N₆ rings and K- ions that have P6/mmm symmetry. An analysis of the mechanism behind such a transformation shows the importance of direct plasma–chemical effects in polymerization, while the crystal structure changes are believed to be due to plasma-emitted radiation in the ultraviolet range. Full article

Background and Objectives: Constipation affects health-related quality of life and increases hospital visits. We conducted this prospective cohort study to assess laxative use, health outcomes of constipation in medically hospitalized patients, and related health outcomes. Materials and Methods: A prospective single-center study included all adult patients admitted under the General Internal Medicine Unit from 1 February 2022, to 31 August 2022. Constipation was defined using the Constipation Assessment Scale (CAS). Patients were assessed for 28 days during their hospital stay and up to 90 days post-discharge. Result: Among the included patients, 62.45% experienced constipation, which was associated with poor health outcomes including delirium (p = 0.048), intensive care admission (p < 0.01), cardiopulmonary arrest (p < 0.01), inpatient mortality (p < 0.01), longer hospital stay (p < 0.01), 90-day mortality (p < 0.01), and 90-day hospital readmission (p < 0.01). Laxative treatment was administered to only 33.93% of patients with constipation and was more commonly used among older patients (p < 0.01), those with high CAS scores (p < 0.01), longer hospital stays (p < 0.01), and critically ill patients (intensive care admission) (p = 0.01), as well as those who had cardiopulmonary arrest (p < 0.01) and high inpatient mortality (p < 0.01). Conclusions: This study identified several associations between constipation and poor health outcomes and highlighted the underutilization of laxatives in treating constipation. It is vital to interpret our results with caution. Therefore, we believe that a randomized controlled trial will help enhance our understanding of the interaction between constipation, laxative use, and poor health outcomes. Full article

Bronchial-subarachnoid fistulas are rare occurrences, which are not well defined in the literature. This uncommon clinical phenomenon may result in symptomatic pneumorrhachis and presents unique clinical challenges. This report details a case of a 53-year-old female whose treatment for recurrent chondrosarcoma of the thoracic spine included multiple surgeries and radiotherapy. Two weeks after her most recent debulking surgery, she experienced a rapid onset of unusual symptoms, including headache, back and neck spasms, bladder incontinence, and confusion. The source of her symptoms was found to be secondary to pneumorrhachis from a pre-existing bronchial-pleural fistula that had fistulized to the subarachnoid space discovered on computed tomography (CT) and confirmed intraoperatively. The patient was treated successfully with high-flow oxygen therapy and bed rest, followed by surgical correction of both a pleural air leak and a dural defect with muscular flaps. The patient was discharged home in stable condition and remained clinically free of recurrent bronchial-subarachnoid fistula six months after surgical repair. This case contributes to the existing literature by providing detailed clinical insights into the diagnosis and successful management of a bronchial-subarachnoid fistula leading to pneumorrhachis, thereby highlighting the importance of early recognition and intervention and underscoring the need for further research in this area. Full article

Background: Post COVID-19 syndrome or long COVID (LC) is a novel fluctuating condition with a protracted course in some patients. Specialist LC services have been operational in the UK since 2020 and deal with a high caseload of patients. Aims: To evaluate long-term outcomes in patients discharged from a community-based LC specialist service. Methods: A service evaluation study that included patients who were well engaged in the services [completed the standard Patient Reported Outcome Measures (PROMs) and received intervention from clinician(s)] and had been discharged for at least 3 months from the service. They consented to the study and completed standard PROMs: COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), EQ-5D-5L and National Institute for Health and Care Excellence (NICE) criteria for myalgia encephalomyelitis/chronic fatigue syndrome (ME/CFS). Results: Out of 460 patients contacted, 112 (average of 37.6 months since infection and 9.8 months post-discharge) completed the PROMs. Of these, 90.2% patients continued to experience LC symptoms and disability and had not returned to their pre-COVID-19 health status. The average EQ-5D-5L index score was 0.53 (SD 0.29), highlighting a significant disability and that LC had become a long-term condition (LTC) in the majority of patients who responded to the survey. Of these patients, 43% met the criteria for suspected ME/CFS. Conclusions: A proportion of LC patients develop persistent long COVID (PLC) consistent with a LTC and had a significant overlap with ME/CFS. Full article

The Sierra Seca aquifer system is located in the northeast (NE) of the province of Granada, in the Prebetic Domain (Betic Cordillera). It is composed of different aquifer units hosted in the Lower Cretaceous and Upper Cretaceous limestones. The two aquifers are separated by a low permeability marl layer, which effectively acts as a barrier between them. To outline the behavior of the hydrogeological system, 407 samples of precipitation and 67 samples of groundwater were obtained from May 2020 to Oct. 2022 and isotopically (${\delta }^{18}O$ and ${\delta }^{2}H$) analyzed. For the estimation of the recharge elevation, a new methodology has been applied to estimate the isotopic content of recharge as a function of precipitation. This allowed the evaluation of the vertical gradient of both precipitation (${\nabla }_Z{\delta }^{18}{O}_P=-2.9‰/\mathrm{k}\mathrm{m}$) and aquifer recharge (${-4.4‰/\mathrm{k}\mathrm{m}\le \nabla }_Z{\delta }^{18}{O}_R\le -2.9‰/\mathrm{k}\mathrm{m}$). Therefore, estimating (1) the recharge zone elevation associated with the aquifer system, which is comprised between 1500 and 1700 m a.s.l., and (2) the transit time of recharge to reach the outflow point of the aquifer system, which varies between 4 and 5 months, is possible. Additionally, three tracer tests were conducted to outline the hydrologic connection between the recharge and discharge zones of the aquifer system. The results show that the Fuente Alta spring drains the limestones of the Lower Cretaceous, while La Natividad spring does the same with the limestones of the Upper Cretaceous. In the case of the Enmedio spring, groundwater discharge is related to infiltration through the streambed of the watercourse fed by the Fuente Alta spring. Full article

In this work, a comprehensive multi-physics electrochemical hybrid stack model is developed for a vanadium redox flow battery (VRFB) stack considering electrolyte flow, mass transport, electrochemical reactions, shunt currents, and as heat generation and transfer simultaneously. Compared with other VRFB stack models, this model is more comprehensive in considering the influence of multiple factors. Based on the established model, the electrolyte flow rate distribution across cells in the stack is investigated. The distribution and variation in shunt currents, single-cell current and single-cell voltage are analyzed. The distribution and variation in temperature and heat generation and heat transfer are also researched. It can be found that the VRFB stack temperature will exceed 40 °C when operating at 60 A and 100 mA cm⁻² at an ambient temperature of 30 °C, which will lead to electrolyte ion precipitation, affecting the performance and safety of the battery. To control the stack temperature below 40 °C, a new tank cooling control strategy is proposed, and the suitable starting cooling point and the controlled temperature are specified. Compared with the common room cooling strategy, the new tank cooling strategy reduces energy consumption by 27.18% during 20 charge–discharge cycles. Full article

Background/Objectives: Refeeding syndrome (RFS) is recognized as a potentially fatal metabolic disturbance, particularly concerning for non-critically ill patients who do not receive frequent electrolyte assessments. Assessing the risk of developing RFS and implementing preventive strategies is essential in these cases. We investigated the proportion of risk and its association with prognosis in a high-dependency unit (HDU). Method: This observational study was conducted in a tertiary care hospital’s HDU in Japan. We consecutively enrolled all patients who had been admitted urgently to the HDU and hospitalized for three days or more. We evaluated the National Institute for Health and Clinical Excellence (NICE) RFS risk factors at admission and classified patients into four groups based on the modified NICE criteria. The primary outcome was 30-day in-hospital mortality. The secondary outcome was a composite of 30-day in-hospital mortality and transfer to the intensive care unit, or discharge to locations other than home. Using logistic regression, we assessed the association between the four risk groups and outcomes, using the no-risk group as a reference. Results: A total of 955 patients were analyzed, of which 33.1%, 26.7%, 37.8%, and 2.4% were classified into the no-risk, low-risk, high-risk, and very high-risk groups, respectively. The 30-day in-hospital mortality was 4.4%, 5.5%, 5.0%, and 21.7%, respectively (Log-rank trend test: p = 0.047). In multivariable logistic regression, adjusting for sepsis, comorbidities, and age, only the very high-risk group was associated with 30-day in-hospital mortality (odds ratio: 5.54, 95% confidence interval: 1.73–17.79) A similar association was observed for the secondary outcomes. Conclusions: For patients admitted urgently to the HDU, there may be an opportunity to improve outcomes for very high-risk patients through preventive strategies. Full article

Objective: This study investigates the effectiveness of extubation from conventional mechanical ventilation using an endotracheal tube (MVET) compared to synchronized non-invasive positive-pressure ventilation (sNIPPV) using neurally adjusted ventilatory assist (NAVA) and conventional non-invasive positive-pressure ventilation (NIPPV) in extremely low-birth-weight (ELBW) infants. Methods: An institutional review board (IRB) approved this study (#12175) to conduct a single-center randomized control trial including 60 ELBW infants assigned in a one-to-one computer-generated scheme to either sNIPPV using NAVA or NIPPV. The primary outcome involved the need for reintubation, and the secondary outcome involved the assessment of moderate/severe BPD, defined as an oxygen requirement at 36 weeks, as in #NCT03613987 (clinicaltrials.gov). Results: There were 60 ELBW infants enrolled and randomized. The overall gestational age was 26 (1.5) weeks, and the birth weight was 773 (157) g [mean (SD)]. There were no statistically significant differences between the NAVA and NIPPV patient characteristics. There was a 41% extubation failure rate in the NIPPV group and 35% in the NAVA group (p = NS). The NAVA group had less moderate and severe BPD (p = 0.03), a shorter oxygen therapy duration (p = 0.002), a decreased length of stay (p = 0.03), and less need for home oxygen (0, 43%; p = 0.0004). Conclusions: This study found similar extubation failure rates among ELBW infants as in prior studies. However, the NAVA group had lower rates of moderate/severe BPD and need for oxygen at discharge, as well as shorter oxygen therapy duration and length of stay. The use of NAVA may be a reasonable alternative mode of non-invasive ventilation in the ELBW population. Full article

Background: Proximal humeral fractures (PHFs) are common, especially in the elderly, and account for 4% to 10% of all fractures, with women more often affected than men. Treatments include conservative methods, internal fixation and arthroplasty, with surgical approaches increasingly being used due to technological advancements. This study analyzes the evolution of PHF treatments in Italy from 2001 to 2022, using data from the Italian Hospital Discharge Records (HDRs) Database, and includes a stratified analysis by age and sex. Methods: Using HDR data from 2001 to 2022, records with ICD9-CM codes for proximal humeral fractures (812.0 and 812.1) among diagnoses were selected and categorized into three treatment groups: arthroplasty, fixation and conservative. Time series were analyzed with stratification by sex and age. Results: The extracted data included 486,368 records of PHFs, with 223,742 cases treated surgically (arthroplasty or internal fixation) and 262,626 treated conservatively; the average patient age was 66.6 years, with a higher proportion of women, especially among arthroplasty patients. Over time, the use of fixation and arthroplasty increased from 20% of treatments in 2001 to over 60% in 2022, with fixation becoming the most common treatment method by 2014 and arthroplasty significantly increasing among women, particularly in the 65–74 and 75–84 age groups. Conclusions: The study shows that in Italy, over the past two decades, treatment for PHFs has shifted from conservative methods to a preference for internal fixation and increasingly for arthroplasty, particularly among women and patients aged 65–84, reflecting evolving trends and technological improvements. Full article

Artificial intelligence (AI), including machine learning (ML) and deep learning (DL), learns by training and is restricted by the amount and quality of training data. Training involves a tradeoff between prediction bias and variance controlled by model complexity. Increased model complexity decreases prediction bias, increases variance, and increases overfitting possibilities. Overfitting is a significantly smaller training prediction error relative to the trained model prediction error for an independent validation set. Uncertain data generate risks for AI–ML because they increase overfitting and limit generalization ability. Specious confidence in predictions from overfit models with limited generalization ability, leading to misguided water resource management, is the uncertainty-related negative consequence. Improved data is the way to improve AI–ML models. With uncertain water resource data sets, like stream discharge, there is no quick way to generate improved data. Data assimilation (DA) provides mitigation for uncertainty risks, describes data- and model-related uncertainty, and propagates uncertainty to results using observation error models. A DA-derived mitigation example is provided using a common-sense baseline, derived from an observation error model, for the confirmation of generalization ability and a threshold identifying overfitting. AI–ML models can also be incorporated into DA to provide additional observations for assimilation or as a forward model for prediction and inverse-style calibration or training. The mitigation of uncertain data risks using DA involves a modified bias–variance tradeoff that focuses on increasing solution variability at the expense of increased model bias. Increased variability portrays data and model uncertainty. Uncertainty propagation produces an ensemble of models and a range of predictions. Full article

Background: Depression in type 2 diabetes mellitus (T2DM) impacts glycemic control and complications. This study examines the influence of depression on compliance with recommended annual diabetes assessments in patients within the Local Healthcare Authority of Romagna. From a clinical health psychology perspective, understanding how depression influences patients’ engagement in managing their conditions is crucial. This insight can help improve healthcare services by ensuring they address mental health needs and thereby enhance treatment effectiveness and overall patient outcomes. Methods: This retrospective cohort study included residents of Romagna with incident T2DM from 2015 to 2017, followed from 1 January 2018 to 31 December 2022. Depression was identified via hospital discharge records or antidepressant prescriptions. Adherence to diabetes care guidelines was measured using the Guideline Composite Indicator (GCI). Results: The study included 13,285 patients, with a mean age of 61.1 years. Prevalence of post-diabetes depression increased from 3.0% in 2018 to 8.9% in 2022. Initial analyses showed higher GCI rates among patients with depression. However, propensity-score adjustment revealed that by 2021–2022, patients with pre-diabetes depression had 5% lower compliance rates (p-value ≤ 0.05). Older adults with depression had reduced adherence, while younger adults with post-diabetes depression had higher adherence rates. Conclusions: Depression significantly affects adherence to diabetes care guidelines in T2DM patients, particularly among older adults. Integrated care models addressing both diabetes and depression are crucial for improving health outcomes. Full article