bluuebunny/crossref_metadata_2025 huggingface dataset:
Exchange Rate Volatility Effect on Economic Growth under Different Exchange Rate Regimes: New Evidence from Emerging Countries Using Panel CS-ARDL Model
Authors: Ameziane Karim , Benyacoub Bouchra
Published: October 2022

This paper analyzes the impact of exchange rate volatility on economic growth under various exchange rate regimes. It empirically examines this issue in 14 emerging countries from 1990 to 2020. This study has three particularities: First, we use the GARCH model to generate the conditional variance, which will be used as a proxy variable for the exchange rate volatility. Second, to address our issue, we employ the Panel CS-ARDL model, one of the most recent models for handling panel cases. Third, we apply the Dumitrescu and Hurlin Granger non-causality test to capture the potential indirect effect that exchange rate volatility can have on economic growth through the channel of its determinants. The results of our study demonstrate that exchange rate volatility costs emerging countries both directly and indirectly in terms of growth. However, by controlling our countries according to the adopted exchange rate regime, we find that the magnitude of this impact tends to be stifled in the case of countries adopting intermediate exchange rate regimes. Through their combination of rigidity and flexibility, intermediate exchange rate regimes appear to be more effective in mitigating the direct effects of exchange rate volatility on economic growth.
Use of Derivatives and Market Valuation of the Banking Sector: Evidence from the European Union
Authors: Miloș Marius Cristian , Miloș Laura Raisa
Published: October 2022

(1) Background: This paper aims to investigate whether the derivatives usage by the banking sector in the European Union has impacted its market valuation in the aftermath of the financial crisis. (2) Methods: Our analysis takes 120 European financial institutions listed on the European Union stock exchange over a period of 14 years into account (2008–2021). We use the generalized method of moments (GMM) to assess whether the use of derivatives allows financial intermediaries to increase their market value. Control variables, such as size, profitability, expectations of the market, bank risk, liquidity performance, and financial condition, are also taken into consideration. (3) Results: Our main findings suggest that market value is affected negatively by derivative asset accumulation. (4) Conclusions: The results are in line with the studies that investigated the impact of financial derivatives on the market value and found a negative connection between the two, justified by the suboptimal hedging or the higher volatility of the earnings.
The Need to Articulate Historic and Cultural Dimensions of Landscapes in Sustainable Environmental Planning—A Swedish Case Study
Authors: Eliasson Ingegärd , Fredholm Susanne , Knez Igor , Gustavsson Eva
Published: October 2022

Ignoring the historic and cultural dimensions of landscapes makes environmental planning unsustainable, which in the long run, will have a negative impact on both the environment and society. This paper examines the work and perceptions of practitioners with a focus on the role of historic and cultural landscape dimensions and their relation to the recent implementation of the ecosystem service framework in sustainable environmental planning. Semi-structured interviews with officials at local and regional planning levels in a Swedish case study showed that the historical landscape forms the basis for environmental work. Respondents expressed an integrated view of the landscape, and historic and cultural landscape dimensions were considered important in the initial planning process. However, several challenges existed later in the planning process and final decision-making, such as conceptual ambiguities, unclear policy and assignments, limited cross-sectorial coordination and lack of awareness, knowledge, resources and other priorities. The results also show that the respondents worked regularly with intangible landscape dimensions, which can be defined as cultural ecosystem services, but they do not label them as such. Furthermore, established knowledge and expertise of heritage planning was not activated in the implementation of the ecosystem service approach. We conclude that historic and cultural landscape dimensions are not ignored in practice, but there is a need to articulate these aspects more clearly in order to achieve sustainable environmental planning. There is also an unexplored opportunity to connect skills and create new forms of cross-sectorial collaboration between heritage planning and the ES approach.
Middle-Aged Lpaatδ-Deficient Mice Have Altered Metabolic Measures
Authors: Tomczewski Michelle Victoria , Fernandes Maria Fernanda , Grewal Rajan Singh , Duncan Robin Elaine
Published: October 2022

Lysophosphatidic acid acyltransferases/acylglycerophosphate acyltransferases (LPAATs/AGPATs) are a group of homologous enzymes that catalyze the formation of phosphatidic acid (PA) from lysophosphatidic acid. We have previously reported that LPAATδ/AGPAT4 localizes to mitochondria, suggesting a potential role in energy metabolism. However, in prior studies of young Lpaatδ-deficient mice (age 9–12 weeks old), we found no differences in body weights, food intakes, activity levels, respiratory gas exchange, or energy expenditure compared to their wildtype (Wt) littermates. To test whether Lpaatδ−/− mice may develop differences in metabolic measures with advancing age, we recorded body weights and food intakes, and used metabolic chambers to assess ambulatory and locomotor activity levels, oxygen consumption (VO2), carbon dioxide production (VCO2), respiratory exchange ratio (RER), and total energy expenditure (heat). Fourteen-month-old Lpaatδ−/− mice had significantly lower mean body weights compared to Wt littermate controls (44.6 ± 1.08 g vs. 53.5 ± 0.42 g, respectively), but no significant differences in food intake or activity levels. This phenotypic difference was accompanied by significantly elevated 24 h daily, and 12 h light and dark photoperiod average VO2 (~20% higher) and VCO2 (~30% higher) measures, as well as higher RER and total energy expenditure (heat) values compared to Wt control littermates. Thus, an age-related metabolic phenotype is evident in Lpaatδ−/− mice. Future studies should examine the role of the lipid-modifying enzyme LPAATδ across the lifespan for greater insight into its role in normal and pathophysiology.
Fixation of the Membrane during Matrix-Induced Autologous Chondrocyte Implantation in the Knee: A Systematic Review
Authors: Migliorini Filippo , Vaishya Raju , Bell Andreas , Weber Christian D. , Götze Christian , Maffulli Nicola
Published: October 2022

Introduction: It is unclear whether the type of membrane used for matrix-assisted autologous chondrocyte implantation (mACI) influences results. A systematic review was conducted to investigate the midterm results of the three most common types of membrane fixation for mACI. Methods: This systematic review was conducted according to the 2020 PRISMA checklist. PubMed, Google Scholar, Embase, and Scopus online databases were accessed in August 2022. All the prospective clinical trials reporting outcomes of mACI in the knee were considered. Studies that describe the modality of membrane fixation (glued, glued, and sutured, no fixation) used for mACI were eligible. Studies that conducted a minimum of 12 months of follow-up were considered. The outcomes of interest were the Tegner Activity Scale and International Knee Documentation Committee (IKDC) score. The rate of failure and revisions were also collected. Results: Data from 26 studies (1539 procedures; 554 of 1539 (36%) were women) were retrieved. The mean follow-up was 42.6 (12 to 84) months. No difference between the groups was found in terms of mean duration of symptoms, age, BMI, gender, and defect size (P > 0.1). No difference was found in terms of the Tegner score (P = 0.3). When no fixation was used, a statistically significant higher IKDC compared to the other groups (P = 0.02) was evidenced. No difference was found in the rate of failure (P = 0.1). The no-fixation group evidenced a statistically significant lower rate of revisions (P = 0.02). Conclusions: No membrane fixation for mACI in the knee scored better than the fastening techniques at the midterm follow-up.
Bone Remodeling Interaction with Magnesium Alloy Implants Studied by SEM and EDX
Authors: Drobyshev Alexey , Komissarov Alexander , Redko Nikolay , Gurganchova Zaira , Statnik Eugene S. , Bazhenov Viacheslav , Sadykova Iuliia , Miterev Andrey , Romanenko Igor , Yanushevich Oleg
Published: October 2022

The development direction of bioresorbable fixing structures is currently very relevant because it corresponds to the priority areas in worldwide biotechnology development. Magnesium (Mg)-based alloys are gaining high levels of attention due to their promising potential use as the basis for fixating structures. These alloys can be an alternative to non-degradable metal implants in orthopedics, maxillofacial surgery, neurosurgery, and veterinary medicine. In our study, we formulated a Mg-2Zn-2Ga alloy, prepared pins, and analyzed their biodegradation level based on SEM (scanning electron microscopy) and EDX (energy-dispersive X-ray analysis) after carrying out an experimental study on rats. We assessed the resorption parameters 1, 3, and 6 months after surgery. In general, the biodegradation process was characterized by the systematic development of newly formed bone tissue. Our results showed that Mg-2Zn-2Ga magnesium alloys are suitable for clinical applications.
Effect of Secondary-Phase Precipitation on Mechanical Properties and Corrosion Resistance of 00Cr27Ni7Mo5N Hyper-Duplex Stainless Steel during Solution Treatment
Authors: Wang Hang , Wang Aiqin , Li Changyi , Yu Xingsheng , Xie Jingpei , Liu Chenlu
Published: October 2022

In this work, the effect of secondary-phase precipitation on the microstructure, mechanical properties, and corrosion resistance of 00Cr27Ni7Mo5N hyper-duplex stainless steel (HDSS) during solution treatment was investigated. The results reveal that σ-phase precipitates at the interface between the α and γ phase when the solution treatment temperature is lower than 1070 °C. It is not only brittle, but also prone to create a Cr-depleted zone, which significantly deteriorates the mechanical properties and corrosion resistance. With the increase in the solution treatment temperature, the volume fraction of ferrite gradually increases. The yield strength and tensile strength increase slightly, but the elongation decreases. At the same time, the impact toughness shows a trend of first increasing and then decreasing. When the solution treatment temperature is higher than 1130 °C, Cr2N precipitates in the ferrite. The precipitation of Cr2N causes a decrease in the plastic toughness, but it does not deteriorate the mechanical properties as significantly as the σ phase. However, it can also cause the formation of a Cr-depleted zone that significantly decreases the corrosion resistance. There is no secondary-phase precipitation in the sample after solution treatment at 1100 °C, which shows the best mechanical properties and corrosion resistance.
A Study on Mechanical and Microstructural Characteristics of Concrete Using Recycled Aggregate
Authors: Joseph Herbert Sinduja , Pachiappan Thamilselvi , Avudaiappan Siva , Flores Erick I. Saavedra
Published: October 2022

The objective of this paper is to provide a comprehensive study about the performance of concrete using mixed coarse recycled aggregate (MCRA) as an alternative for natural aggregate (NA) at replacement levels of 0, 30, 60, and 100%, which can greatly reduce the environmental pollution by incorporating the construction and demolition wastes in the reproduction of concrete. The focus of this study was to use the raw MCRA that was directly obtained from a recycling plant and not further processed. Initially, MCRA was studied to ascertain if its property meets the recommended Indian standards for natural aggregates. Using the slump test, the workability of freshly prepared concrete with a characteristic strength of 30 MPa was assessed. Additionally, the mechanical performance of concrete was assessed on the specimens prepared in the different forms: cubes, cylinders, and beams. Moreover, Scanning Electron Microscopy (SEM) with EDAX, XRD, and FTIR were used to study the microstructural behavior of selected optimum and control mixes at 7 and 28 days of curing. The studies revealed that a higher MCRA content improved the workability of concrete and 30% replacement of MCRA improved the compressive strength by 11.01, 6.98, 6.19, and 14.24% at 7, 28, 56, and 90 days respectively. At the same time, the 30% replacement of the MCRA mix showed an improved split tensile and flexural strength by 2.92 and 6.26%, respectively. The microstructural analysis showed that the optimum mixture had a more condensed microstructure. Therefore, 30% replacement of MCRA can be incorporated in the characteristic strength of concrete of 30 MPa. In particular, MCRA incorporation had a positive influence similar to conventional concrete on the physical, mechanical, and microstructural properties, which can increase the utilization of all kinds of directly obtained construction and demolition wastes to increase the circular economy in the construction sector.
Mesosphere of Carbon-Shelled Copper Nanoparticles with High Conductivity and Thermal Stability via Direct Carbonization of Polymer Soft Templates
Authors: Huang Min , Cao Xinyu , Zhang Jingnan , Liu Huiqun , Lu Jiaxin , Yi Danqing , Ma Yongmei
Published: October 2022

Copper nanoparticle (Cu NP) is a promising replacement for noble metal nanoparticles due to its high electrical conductivity and low cost. However, Cu NPs are relatively active compared to noble metals, and current ways of protecting Cu NPs from oxidation by encapsulation have severe drawbacks, such as a long reaction time and complicated processes. Here, a facial and effective method to prepare the mesosphere of carbon-shelled copper nanoparticles (Cu@MC) was demonstrated, and the resulting Cu@MC was both highly electrically conductive and thermally stable. Cu@organic (100 nm) was first synthesized by the reduction of Cu ions with poly (vinyl pyrrolidone) (PVP) and sodium poly ((naphthalene-formaldehyde) sulfonate) (Na-PNFS) as soft templates. Then, the carbon shells were obtained by in situ carbonization of the polymer soft templates. The Cu@organic and Cu@MC showed an anti-oxidation ability up to 175 and 250 °C in the air atmosphere, respectively. Furthermore, the Cu@MC exhibited excellent volume resistivity of 7.2 × 10−3 Ω·cm under 20 MPa, and showed promising application potential in electric sensors and devices.
Proposition for Determining the Residual Strength of Fiber-Reinforced Cement Composite
Authors: Głodkowska Wiesława , Laskowska-Bury Joanna
Published: October 2022

Designing bending elements made of fiber composites requires knowledge of the residual strengths. Residual strengths determined according to PN-EN 14651, regardless of the type of matrix and the fibers used, are characterized by a very-high coefficient of variation, about 30%. The variability of this feature is so large that the normal distribution adopted in statistical analyses, which is consistent for compressive strength or tensile strength, may, in the case of residual strengths, result in a significant overdesign of the elements. Therefore, the article proposes a novel method of determining the residual strength with the use of centrally bent square plates simply supported at the perimeter. The coefficient of variation of this characteristic in the case of plate testing is about 8%.
Ultrasonic-Assisted Rapid Preparation of Sulfonated Polyether Ether Ketone (PEEK) and Its Testing in Adsorption of Cationic Species from Aqueous Solutions
Authors: Baltag Laurentiu , Cojocaru Corneliu , Enache Andra-Cristina , Samoila Petrisor , Harabagiu Valeria
Published: October 2022

Herein, we report a new approach for the sulfonation of polyether ether ketone (PEEK) following a shorter path of reaction undertaken at 60 °C under ultrasonication. The application of this method enabled the reduction of the reaction time from several hours to less than one hour, achieving a relevant sulfonation degree. The sulfonated-PEEK (SPEEK) was characterized by advanced chemical and physical instrumental methods. According to 1H-NMR analysis, the degree of sulfonation of the polymer was equal to 70.3%. Advanced microscopy (SEM) showed that the fabricated SPEEK beads (2–4 mm) were porous inside with a log-normal distribution of pore sizes within the range 1.13–151.44 μm. As an application, the SPEEK polymer was tested for the adsorption of a cationic organic pollutant (Methylene blue, MB) from aqueous solutions. The equilibrium studies (isotherms) disclosed maximum adsorption capacities of 217 mg/g, 119 mg/g, and 68 mg/g at temperatures of 323 K, 313 K, and 300 K, respectively. The thermodynamic calculations indicated an endothermic effect (ΔHad = +11.81 kJ/mol) of the investigated adsorption process. The maximum removal efficiency of 99.14% was established by process optimization using the design of experiments strategy and data-driven modeling. Additionally, molecular docking simulations were performed to disclose the mechanism of interaction at the molecular level between the adsorbent (SPEEK) and pollutant.
Industry 4.0-Oriented Turnkey Project: Rapid Configuration and Intelligent Operation of Manufacturing Systems
Authors: Xie Shulian , Zhang Weimin , Xue Feng , Li Dongdong , Liu Yangbokun , Fleischer Jürgen , Ehrmann Christopher
Published: October 2022

More extensive personalized product requirements and shorter product life cycles have put forward higher requirements for the rapid establishment, commissioning, and operation of corresponding manufacturing systems. However, the traditional manufacturing system development process is complicated, resulting in a longer delivery time. Many manufacturing enterprises, especially small and micro enterprises, may not have the necessary manufacturing knowledge or capabilities to meet these requirements. Therefore, it is essential to promote the construction of turnkey projects under the paradigm of Industry 4.0, parallelizing and integrating the existing manufacturing system development process based on mass manufacturing equipment to quickly provide turnkey solutions for manufacturing systems’ configuration and implementation for these enterprises. This paper aims to extract and refine the configuration and operation key views of the Industry 4.0-oriented Turnkey Project (I4TP) from Reference Architecture Model Industrie 4.0 (RAMI4.0) and use it to guide the development of key functional processes of turnkey projects to achieve rapid configuration and efficient operation management of manufacturing systems. The turnkey project platform in the Advanced Manufacturing Technology Center (AMTC) is taken as a demonstration case to provide a reference idea for the rapid configuration and intelligent operation of the turnkey manufacturing system.
Enzymatic Degradation of Fiber-Reinforced PLA Composite Material
Authors: Urinov Eldor , Hanstein Stefan , Weidenkaff Anke
Published: October 2022

Application of thermoplastic fiber-reinforced lightweight composite materials provides a wide range of advantages that are of particular importance for the mobility sector. UD tapes composed of unidirectionally (UD) oriented inorganic fibers embedded in a thermoplastic matrix represent light-weight materials with high tensile strength. This publication addresses recycling aspects of novel UD tape made of a combination of basalt fibers and different PLA (polylactic acid) formulations. The kinetics of enzyme-based separation of polymer from the fiber were investigated. Different types of UD tapes with a thickness of 270–290 µm reinforced with basalt fiber weight ratios ranging between 51 and 63% were incubated at 37 °C in buffer solution (pH 7.4) containing proteinase K. The influence of enzyme concentration, tape weight per incubation tube, proteinase K activators, and tape types on the rate of enzymatic decomposition was investigated. Enzyme activity was measured by analyzing lactate concentration with lactate dehydrogenase and by measuring weight loss of the composite material. The rate of lactate release increased in the first 30 min of incubation and remained stable for at least 90 min. Weight loss of 4% within 4 h was achieved for a tape with 56% (w/w) fiber content. For a sample with a surface area of 3 cm2 in a buffer volume of 10 mL, the rate of lactate release as a function of enzyme concentration reached saturation at 300 µg enzyme/mL. With this enzyme concentration, the rate of lactate release increased in a linear manner for tape surface areas between 1 and 5 cm2. Four tapes with different PLA types were treated with the enzyme for 17 h. Weight loss ranged between 7 and 24%. Urea at a concentration of 0.5% (w/v) increased lactate release by a factor of 9. Pretreatment of tapes in alkaline medium before enzymatic degradation increased weight loss to 14% compared to 5% without pretreatment. It is concluded that enzymatic PLA hydrolysis from UD tapes is a promising technology for the release of basalt fibers after alkaline pretreatment or for the final cleaning of basalt fibers.
Analysis of Formation Mechanism of Slightly Inclined Bedding Mudstone Landslide in Coal Mining Subsidence Area Based on Finite–Discrete Element Method
Authors: Zhong Jiaxin , Mao Zhengjun , Ni Wankui , Zhang Jia , Liu Gaoyang , Zhang Jinge , Geng Mimi
Published: October 2022

In this paper, the formation mechanism of a slightly inclined bedding mudstone landslide in the overlying mountain of the coal mining subsidence area of the Tanshan Coal Mine in Ningxia, China, is studied. By means of geotechnical investigation, indoor geotechnical tests, theoretical analysis and other technical means, we find the geological environment background of the study area and obtain the physical and mechanical property indexes of the mining landslide in the Tanshan Coal Mine. By combining the numerical simulation of discrete elements and finite elements, the macro deformation and failure law of the mining mudstone landslide and the displacement and stress nephogram of the failure process are discussed. The results show that the slightly inclined bedding mudstone landslide in the Tanshan Coal Mine is 850 m long from east to west, 500 m wide from north to south and 10,875,000 m3 in volume. It is composed of Jurassic mudstone and is a traction landslide caused by the coal mining subsidence area. The formation of the landslide is affected by internal factors and inducing factors. The internal factors are mainly geotechnical types and engineering geological properties, and the inducing factors are mainly coal mining activities and rainfall. By analyzing and summarizing the calculation process of the slope model prior to the landslide in 2D-Block and GeoStudio numerical simulation software, the sliding process of the slightly inclined bedding mudstone landslide in the Tanshan Coal Mine is divided into four stages: slope creep, slope deformation, landslide movement and landslide accumulation. GeoStudio software is used to calculate the stability of the Tanshan Coal Mine landslide under natural and rainfall conditions. The landslide is in a stable state under natural conditions and is basically stable under rainfall conditions. By comparing the calculation results of the limit equilibrium method and the finite element limit equilibrium method, we find that the calculated stability coefficient is more accurate when the appropriate constitutive model is selected. The research results have important reference significance for the prevention and control of the gently inclined bedding mudstone landslide of the overlying mountain in the coal mining subsidence area of the Loess Plateau.
Koopman Operator and Path Integral of Quantum Free-Electron Laser Model
Authors: Iomin Alexander
Published: October 2022

A quantum model of a free-electron laser (FEL) is considered. Two different approaches for the exploration of the the FEL system are considered. In the first case, the Heisenberg equations of motion are mapped on the basis of the initial wave functions, which consists of the photon coherent states and many-dimensional electron coherent states. This mapping is an exact procedure, which makes it possible to obtain an exact equation of motion for the intensity of the laser field in a closed form. The obtained equation is controlled by a Koopman operator. The analytical expression for the evolution of the FEL intensity is obtained in the framework of a perturbation theory, which is constructed for a small time scale. The second way of the consideration is based on the construction of the many-dimensional path integrals for the evolution of the wave function. This method also makes it possible to estimate the time evolution and the gain of the FEL intensity.
A Queueing Model for Traffic Flow Control in the Road Intersection
Authors: Elbaum Yona , Novoselsky Alexander , Kagan Evgeny
Published: October 2022

In this paper, we consider a simple road intersection with traffic light control and suggest a queueing model for the traffic flow in the intersection. The suggested model implements the well-known queue with state-dependent departure rates. Using this model, we define optimal state-dependent scheduling of the traffic lights in the intersection and consider its properties. Activity of the model is illustrated by numerical simulations. It is demonstrated that in practical conditions the suggested scheduling of the traffic lights allows the prevention of traffic jams in the intersection and resolves vehicles queues with reasonable waiting times in the crossing lanes.
Computational Metabolomics Tools Reveal Subarmigerides, Unprecedented Linear Peptides from the Marine Sponge Holobiont Callyspongia subarmigera
Authors: Castaldi Andrea , Teta Roberta , Esposito Germana , Beniddir Mehdi , De Voogd Nicole , Duperron Sébastien , Costantino Valeria , Bourguet-Kondracki Marie-Lise
Published: October 2022

A detailed examination of a unique molecular family, restricted to the Callyspongia genus, in a molecular network obtained from an in-house Haplosclerida marine sponge collection (including Haliclona, Callyspongia, Xestospongia, and Petrosia species) led to the discovery of subarmigerides, a series of rare linear peptides from Callyspongia subarmigera, a genus mainly known for polyacetylenes and lipids. The structure of the sole isolated peptide, subarmigeride A (1) was elucidated through extensive 1D and 2D NMR spectroscopy, HRMS/MS, and Marfey’s method to assign its absolute configuration. The putative structures of seven additional linear peptides were proposed by an analysis of their respective MS/MS spectra and a comparison of their fragmentation patterns with the heptapeptide 1. Surprisingly, several structurally related analogues of subarmigeride A (1) occurred in one distinct cluster from the molecular network of the cyanobacteria strains of the Guadeloupe mangroves, suggesting that the true producer of this peptide family might be the microbial sponge-associated community, i.e., the sponge-associated cyanobacteria.
Transitional Care Programs for Patients with High Nursing Activity Scores Reduce Unplanned Readmissions to Intensive Care Units
Authors: Haruna Junpei , Masuda Yoshiki , Tatsumi Hiroomi
Published: October 2022

Background and Objectives: The main objective of a transitional care program (TCP) is to detect patients with early deterioration following intensive care unit (ICU) discharge in order to reduce unplanned ICU readmissions. Consensus on the effectiveness of TCPs in preventing unscheduled ICU readmissions remains lacking. In this case study assessing the effectiveness of TCP, we focused on the association of unplanned ICU readmission with high nursing activities scores (NASs), which are considered a risk factor for ICU readmission. Materials and Methods: This retrospective observational study analyzed the data of patients admitted to a single-center ICU between January 2016 and December 2019, with an NAS of >53 points at ICU discharge. The following data were extracted: patient characteristics, ICU treatment, acute physiology and chronic health evaluation II (APACHE II) score at ICU admission, Charlson comorbidity index (CCI), 28-day mortality rate, and ICU readmission rate. The primary outcome was the association between unplanned ICU readmissions and the use of a TCP. The propensity score (PS) was calculated using the following variables: age, sex, APACHE II score, and CCI. Subsequently, logistic regression analysis was performed using the PS to evaluate the outcomes. Results: A total of 143 patients were included in this study, of which 87 (60.8%) participated in a TCP. Respiratory failure was the most common cause of unplanned ICU readmission. The unplanned ICU readmission rate was significantly lower in the TCP group. In the logistic regression model, TCP (odds ratio, 5.15; 95% confidence interval, 1.46–18.2; p = 0.01) was independently associated with unplanned ICU readmission. Conclusions: TCP intervention with a focus on patients with a high NAS (>53 points) may prevent unplanned ICU readmission.
Energy Devices for Clipless–Sutureless Laparoscopic Appendectomy: A Systematic Review and Meta-Analysis on Utility and Safety
Authors: Singh Apoorv , Anand Sachit , Pakkasjärvi Niklas , Verma Ajay , Bajpai Minu
Published: October 2022

Background and Objectives: While laparoscopic appendectomy is standardized, techniques for appendiceal stump closure and mesoappendix division remain variable. Novel vessel sealing techniques are increasingly utilized ubiquitously. We sought to systematically summarize all relevant data and to define the current evidence on the safety and utility of energy devices for clipless–sutureless laparoscopic appendectomy in this systematic review and meta-analysis. Materials and Methods: This review was conducted following the PRISMA guidelines. PubMed, Embase, Scopus, and Web of Science were systematically searched. Inclusion criteria included studies with laparoscopic appendectomy for appendicitis. The intervention included patients undergoing division of mesoappendix and/or securing of the appendicular base using diathermy (Monopolar or Bipolar or LigaSure Sealing Device) or Harmonic Scalpel (Group A) compared to patients undergoing division of mesoappendix and/or securing of the appendicular base using endoclip or Hem-o-lok or ligature (Group B). The methodological quality of the included studies was assessed using the Downs and Black scale. The outcomes of surgical site infection (SSI) or intra-abdominal collection, postoperative ileus, average operative duration, and length of hospital stay (LHS) were compared. Results: Six comparative studies were included; three were retrospective, two were prospective, and one was ambispective. Meta-analysis revealed a shorter operative duration in Group A with respect to appendicular base ligation (MD −12.34, 95% CI −16.57 to −8.11, p < 0.00001) and mesoappendix division (MD −8.06, 95% CI −14.03 to −2.09, p = 0.008). The pooled risk ratios showed no difference in SSI between groups. Additionally, no difference was observed in LHS. The risk of postoperative ileus was higher in group B regarding mesoappendix division (RR 0.56, 95% CI 0.34 to 0.93, p = 0.02), but no difference was found concerning appendicular base ligation. The included studies showed a moderate-to-high risk of bias. Conclusions: Clipless–sutureless laparoscopic appendectomy is safe and fast. Postoperative ileus seems less common with energy devices for mesoappendix division. However, the studies included have a moderate-to-high risk of bias. Further studies addressing the individual devices with surgeons of similar levels are needed.
Risk Factors for Feeding and Swallowing Disorders in Very Low Birth Weight Infants in Their Second Year of Life
Authors: Slana Nuša , Hočevar-Boltežar Irena , Kornhauser-Cerar Lilijana
Published: October 2022

Background and Objectives: This study aimed to identify the prevalence of feeding and swallowing disorders (FSD) in very low birth weight (VLBW, 1500 g or less) infants in the first two years after discharge from the maternity hospital, their possible risk factors, and the consequences of them. Materials and Methods: A total of 117 preterm children with VLBW born between 2013 and 2015 were included. The data concerning possible FSD after discharge from the hospital were obtained through accessible medical documentation for the child and a short parental questionnaire. Results: FSD was reported in 32 (27.4%) infants following discharge from the hospital but in only five children (4.3%) at a mean age of four years. Four variables (birth gestational age less than 28 weeks, birth weight equal to or less than 1000 g, birth length below 33 cm, and start of oral feeding after the 34th gestational week) were identified as risk factors for FSD after discharge. However, only birth length remained a significant predictor after being included in a binary logistic regression model (p = 0.000). Abnormal oral sensitivity and a decrease in weight to under the 10th percentile were significantly more common in the FSD group at follow-up visits at the age of about 2 years. Conclusions: FSD was still present in more than one-quarter of VLBW infants after discharge from the maternity hospital but mostly disappeared within four years. A birth gestational age under 28 weeks, weight up to 1000 g, the late beginning of per oral feeding, and a birth length below 33 cm were determined to be significant predictive factors for FSD. Having a birth length below 33 cm was associated with an almost 6.5-fold increase in the odds of having persistent FSD after discharge from the hospital. FSD in the first years of life may have an impact on the child’s further growth and development.
Characterization of Commercial Polymer–Carbon Composite Bipolar Plates Used in PEM Fuel Cells
Authors: Hala Miroslav , Mališ Jakub , Paidar Martin , Bouzek Karel
Published: October 2022

Bipolar plates represent a crucial component of the PEM fuel cell stack. Polymer–carbon composites are recognized as state-of-the-art materials for bipolar plate manufacturing, but their use involves a compromise between electrical and heat conductivity, mechanical strength and costs. Thus, all key parameters must be considered when selecting a suitable plate satisfying the demands of the desired application. However, data relevant to commercial materials for such selection are scarce in the open literature. To address this issue, 13 commercially available polymer–carbon composites are characterised in terms of the following parameters: through-plane conductivity, hydrogen permeability, mechanical strength, water uptake, density, water contact angle and chemical stability. None of the materials tested reached the DOE target for electrical conductivity, while five of the materials met the target for flexural strength. The overall best-performing material showed a conductivity value of 50.4 S·cm−1 and flexural strength of 40.1 MPa. The data collected provide important supporting information in selecting the materials most suitable for the desired application. In addition, the key parameters determined for each bipolar plate supply important input parameters for the mathematical modelling of fuel cells.
Monte Carlo Simulations for the Estimation of the Effective Permeability of Mixed-Matrix Membranes
Authors: Cao Zheng , Kruczek Boguslaw , Thibault Jules
Published: October 2022

Recent years have seen the explosive development of mixed-matrix membranes (MMMs) for a myriad of applications. In gas separation, it is desired to concurrently enhance the permeability, selectivity and physicochemical properties of the membrane. To help achieving these objectives, experimental characterization and predictive models can be used synergistically. In this investigation, a Monte Carlo (MC) algorithm is proposed to rapidly and accurately estimate the relative permeability of ideal MMMs over a wide range of conditions. The difference in diffusivity coefficients between the polymer matrix and the filler particle is used to adjust the random progression of the migrating species inside each phase. The solubility coefficients of both phases at the polymer–filler interface are used to control the migration of molecules from one phase to the other in a way to achieve progressively phase equilibrium at the interface. Results for various MMMs were compared with the results obtained with the finite difference method under identical conditions, where the results from the finite difference method are used in this investigation as the benchmark method to test the accuracy of the Monte Carlo algorithm. Results were found to be very accurate (in general, <1% error) over a wide range of polymer and filler characteristics. The MC algorithm is simple and swift to implement and provides an accurate estimation of the relative permeability of ideal MMMs. The MC method can easily be extended to investigate more readily non-ideal MMMs with particle agglomeration, interfacial void, polymer-chain rigidification and/or pore blockage, and MMMs with any filler geometry.
Effect of Distigmasterol-Modified Acylglycerols on the Fluidity and Phase Transition of Lipid Model Membranes
Authors: Pruchnik Hanna , Włoch Aleksandra , Gładkowski Witold , Grudniewska Aleksandra , Chojnacka Anna , Krzemiński Mateusz , Rudzińska Magdalena
Published: October 2022

Plant sterols are known for their health-promoting effects, lowering blood cholesterol levels and alleviating cardiovascular disease. In this work, we continue our research on the asymmetric acylglycerols in which fatty acid residues are replaced by two stigmasterol residues in sn-1 and sn-2 or sn-2 and sn-3 positions as new thermostable carriers of phytosterols for their potential application in foods or as components of new liposomes in the pharmaceutical industry. The aim of this manuscript was to compare and analyze the effects of four distigmasterol-modified acylglycerols (dStigMAs) on the fluidity and the main phase transition temperature of the model phospholipid membrane. Their properties were determined using differential scanning calorimetry (DSC), steady-state fluorimetry and attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR). The determination of the effect of the tested compounds on the mentioned physicochemical parameters of the model membranes will allow for the determination of their properties and stability, which is essential for their practical application. The results indicated that all compounds effect on the physicochemical properties of the model membrane. The degree of these changes depends on the structure of the compound, especially the type of linker by which stigmasterol is attached to the glycerol backbone, as well as on the type of hydrocarbon chain.
An Anisotropic Damage Model for Prediction of Ductile Fracture during Cold-Forging
Authors: Watanabe Atsuo , Hayakawa Kunio , Fujikawa Shinichiro
Published: October 2022

Researchers have formulated equations of ductile fracture to simulate and predict defects in cold-forged parts, e.g., the Cockcroft–Latham criterion. However, these equations are not applicable to certain cases of fracture in forged products. This study formulates a new equation for predicting ductile fractures with better prediction accuracy than the convention by which the cost for trial-and-error design can be reduced. The equation is expressed as a second-rank symmetric tensor, which is the inner product of the stress and strain-increment tensors. The theoretical efficacy of the equation in predicting ductile fractures is verified via a uniaxial tensile test. The practicability of the equation is confirmed by applying it to the simulations of two real cold-forged components: a cold-forged hollow shaft and a flanged shaft. For the hollow shaft, the equation predicts the position where the ductile fracture would initiate, which—to the best of the authors’ knowledge—is unique to this study. For the flanged shaft, the equation predicts the occurrence of diagonal cracks due to different lubrication conditions.
Effects of Alloying Elements on Solidification Structures and Macrosegregation in Slabs
Authors: Zhang Pan , Wang Minglin , Shi Pengzhao , Xu Lijun
Published: October 2022

A Cellular Automaton-Finite Element (CAFE) model and a secondary dendrite arm spacing (SDAS) model are established to study the evolutionary behavior of the macrostructure and the secondary dendrites on a 295 × 2270 mm2 slab cross-section of experimental steel, respectively. The relationship between the element content, SDAS, equiaxed crystal ratio (ECR) and macrosegregation in continuously cast experimental slabs was studied comprehensively. It is found that with the increase in carbon content, the ECR increases at first and then decreases, and the ECR reaches the maximum value when the carbon content is 0.3%. With the increase in carbon content, the SDAS and average grain size of the equiaxed crystal zone increase, whereas the Si and Al content evidently affects the SDAS and average grain size of the equiaxed crystal zone to a greater extent than the Mn content. In addition, the SDAS can be reduced by reducing the content of C and Si within the acceptable range of alloy composition.
Effect of Different Heat Treatments on the Evolution of Novel Al-Si-Cu-Ni-Fe-Re Alloy Fabricated by Selective Laser Melting
Authors: Zhang Jizhe , Yan Pengfei , Yan Biao
Published: October 2022

In this study, Cu and Ni are successfully added to additively manufactured Al-Si alloy by the mixing process to improve the strength and ductility of the alloy. The effects of different heat treatments on the microstructural evolution and bending properties of selective laser-melted Al-Si-Cu-Ni-Fe-Re alloy are systematically investigated to optimize the mechanical properties. Nearly complete dense samples are initially additively manufactured with optimized parameters. The samples display a particular fiber network microstructure in which Cu-rich and Ni-rich phases distribute in an interwoven mesh around the eutectic silicon. After substrate plate heating (SPH) treatment, the network becomes denser, and the bending strength increases by 44.99 ± 1 MPa to 811.11 ± 29 MPa, despite the hardness decreases. Comparatively, solution aging (SQA) treatment results in the fiber network structures transforming into second-phase particles, which leads to a decline in bending strength and a significantly higher degree of ductility. Finally, the mechanisms of changes in microstructure and morphology, as well as mechanical properties after heat treatment, are discussed.
Departure of Nitrogen Bubbles at the Solid–Liquid Interface during the Solidification of Duplex Stainless Steels
Authors: Wang Qian , Xing Chenyang , Wang Rui , Luo Peng , Wang Bo , Zhang Jieyu , Ma Jie
Published: October 2022

The departure of nitrogen bubbles from duplex stainless steel (DSS) is essential for studying the precipitation behavior of bubbles during solidification. In the current work, the numerical and theoretical derivation of analytical formula were used to study the bubble departure at the solid–liquid interface. In the paper, the departure radius of bubbles was deduced by numerical analysis. Based on the works of subcooled boiling flow, the forces of bubbles were analyzed at the solid–liquid interface. The critical condition of bubble departure was theoretically obtained. The effects of various factors on bubble departure and slip were also analyzed. The results showed that the critical radius of the bubble departure increased at the solid–liquid interface when reducing the interface inclination angle, the depth of liquid steel, the contact angle, the flow velocity of liquid steel, and the gas pressure on the surface of liquid steel. Moreover, when the interface inclination angle equaled zero, there was no slip in the interface direction before bubble departure, letting the bubbles float directly. However, when the interface inclination angle equaled π/4 or π/2, the bubbles slid along the interface before bubble departure in the x negative direction, which was more likely to cause the bubbles to be trapped.
Effect of Ca Deoxidation on Toughening of Heat-Affected Zone in High-Strength Low-Alloy Steels after Large-Heat-Input Welding
Authors: Zhang Yinhui , Yang Jian , Du Hailong , Zhang Yu , Ma Han
Published: October 2022

Large-heat-input welding can effectively increase the efficiency and reduce the cost of manufacturing a super-large container ship for marine trade worldwide with thick, high-strength low-alloy (HSLA) steel plates; however, it significantly degrades the toughness of the welding heat-affected zone (HAZ). This paper describes the effect of Ca deoxidation on the impact toughness of simulated coarse-grained HAZs (CGHAZs) in HSLA steels after large-heat-input welding at 400 kJ cm−1. The average impact energy of the CGHAZ increases with an increase in Ca content; in particular, the energy of the steel with 25 ppm Ca content is satisfactorily high, owing to the uniform and fine prior austenite grains. In contrast, the grains in the CGHAZs of the steels with relatively low Ca contents are not uniform, leading to large test variabilities at −20 °C. Failure analyses reveal that the major and secondary cracks preferentially propagate along the coarse and brittle grain boundary ferrite (GBF), but their propagation is retarded by the fine and interlocking intragranular acicular ferrite (IAF) as the grain size decreases. It is therefore recommended to increase the Ca content to about 25 ppm during the deoxidation of steelmaking to improve HAZ toughness by forming fine and uniform prior austenite grains and IAF within grains.
Euclea divinorum Hiern: Chemical Profiling of the Leaf Extract and Its Antioxidant Activity In Silico, In Vitro and in Caenorhabditis elegans Model
Authors: Bogari Hanin A. , Rashied Rasha M. H. , Abdelfattah Mohamed A. O. , Malatani Rania T. , Khinkar Roaa M. , Hareeri Rawan H. , Wink Michael , Sobeh Mansour
Published: October 2022

Euclea divinorum Hiern is a medicinal plant widely distributed in the northeast parts of South Africa. This plant has been used to treat miscarriage and to alleviate gastrointestinal problems. It can also be used externally for the treatment of ulcers and gonorrhea. In this study, we investigated the phytochemical composition of E. divinorum leaf extract using LC-MS and explored its antioxidant properties in vitro and in vivo. The total polyphenolic content of the extract was determined by the Folin–Ciocalteu method. DPPH and FRAP assays were employed to confirm the plant’s antioxidant potential in vitro. A survival assay in the Caenorhabditis elegans model was used to evaluate the extract’s ability to counteract juglone-induced oxidative stress. Moreover, a docking study was performed for the extract’s metabolites, in order to predict possible molecular targets that could explain the antioxidant effect of the plant on a molecular level. This in silico approach was accomplished on three different proteins; xanthine oxidase enzyme, heat shock protein 90 (Hsp90), and induced nitric oxide synthase (iNOS). Docking scores of the resulting poses and their interactions with binding sites’ residues were explored for each protein and were compared to those of simultaneously docked respective co-crystallized and reference substrates. The extract furnished promising antioxidant activities in vitro and in vivo in the C. elegans model that might be attributed to the presence of 46 compounds, which showed several interactions and low binding scores with the tested enzymes. In conclusion, E. divinorum is a promising, safe, and effective antioxidant candidate that could be used to ameliorate oxidative stress-related disorders.