bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical Utility of Pepsin and Bile Acid in Tracheal Secretions for Accurate Diagnosis of Aspiration in ICU Patients
Authors: Bandorski Dirk , Tello Khodr , Erdal Harun , Sommerlad Janine , Wilhelm Jochen , Vadasz Istvan , Hecker Matthias , Walmrath Dieter , Seeger Werner , Krauss Ekaterina , Kuhnert Stefan
Published: August 2023

Background: Aspiration of stomach content or saliva in critical conditions—e.g., shock, intoxication, or resuscitation—can lead to acute lung injury. While various biomarkers in bronchoalveolar lavage fluids have been studied for diagnosing aspiration, none have been conclusively established as early indicators of lung damage. This study aims to evaluate the diagnostic value of pepsin, bile acid, and other biomarkers for detecting aspiration in an intensive care unit (ICU). Materials and methods: In this study, 50 ICU patients were enrolled and underwent intubation before admission. The evaluation of aspiration was based on clinical suspicion or documented instances of observed events. Tracheal secretion (TS) samples were collected within 6 h after intubation using sterile suction catheters. Additional parameters, including IL-6, pepsin, and bile acid, were determined for analysis. Pepsin levels were measured with an ELISA kit, while bile acid, uric acid, glucose, IL-6, and pH value in the tracheal secretion were analyzed using standardized lab methods. Results: The 50 patients admitted to the ICU with various diagnoses. The median survival time for the entire cohort was 52 days, and there was no significant difference in survival between patients with aspiration pneumonia (AP) and those with other diagnoses (p = 0.69). Among the AP group, the average survival time was 50.51 days (±8.1 SD; 95% CI 34.63–66.39), while patients with other diagnoses had a mean survival time of 32.86 days (±5.1 SD; 95% CI 22.9–42.81); the survival group comparison did not yield statistically significant results. The presence of pepsin or bile acid in TS patients did not significantly impact survival or the diagnosis of aspiration. The p-values for the correlations between pepsin and bile acid with the aspiration diagnosis were p = 0.53 and p > 0.99, respectively; thus, pepsin and bile acid measurements did not significantly affect survival outcomes or enhance the accuracy of diagnosing aspiration pneumonia. Conclusions: The early and accurate diagnosis of aspiration is crucial for optimal patient care. However, based on this study, pepsin concentration alone may not reliably indicate aspiration, and bile acid levels also show limited association with the diagnosis. Further validation studies are needed to assess the clinical usefulness and reliability of gastric biomarkers in diagnosing aspiration-related conditions. Such future studies would provide valuable insights for improving aspiration diagnosis and enhancing patient care.
Inter-Rater Reliability of Collateral Status Assessment Based on CT Angiography: A Retrospective Study of Middle Cerebral Artery Ischaemic Stroke
Authors: Dolotova Daria D. , Blagosklonova Evgenia R. , Muslimov Rustam Sh. , Ramazanov Ganipa R. , Zagryazkina Tatyana A. , Stepanov Valentin N. , Gavrilov Andrey V.
Published: August 2023

The importance of assessing the collateral status (CS) in patients with ischaemic stroke (IS) has repeatedly been emphasised in clinical guidelines. Various publications offer qualitative or semiquantitative scales with gradations corresponding to the different extents of the collaterals, visualised mostly on the basis of CTA images. However, information on their inter-rater reliability is limited. Therefore, the aim of this study is to investigate the inter-rater reliability of the scales for collateral assessment. CTA images of 158 patients in the acute period of IS were used in the study. The assessment of CS was performed by two experts using three methodologies: the modified Tan scale, the Miteff scale, and the Rosenthal scale. Cohen’s kappa, weighted kappa and Krippendorff’s alpha were used as reliability measures. For the modified Tan scale and the Miteff and Rosenthal scales, the weighted kappa values were 0.72, 0.49 and 0.59, respectively. Although the best measure of consistency was found for the modified Tan scale, no statistically significant differences were revealed among the scales. The impact of the CS on the degree of neurological deficit at discharge was shown for the modified Tan and Rosenthal scales. In conclusion, the analysis showed a moderate inter-rater reliability of the three scales, but was not able to distinguish the best one among them.
GSH-Activatable Metal-Phenolic Networks for Photothermal-Enhanced Chemotherapy and Chemodynamic Therapy
Authors: Chen Weijun , Yang Meiyang , Li Jie , Chen Zhilan , Hu Lefei , Zhang Jiannan , Cai Liangyu , Qiu Lipeng , Chen Jinghua
Published: August 2023

Chemotherapy (CT) plays an important role in the antitumor process, but the unsatisfactory therapeutic efficacy and the obvious toxic side effects of CT seriously restrict its application. To overcome the limitations of CT, the strategy of chemotherapy enhanced by chemodynamic therapy (CDT) and photothermal therapy (PTT) has been considered a promising approach to improve the anticancer effect. Herein, a novel GSH-activatable Cu2+-Quercetin network (QC) was synthesized via a convenient strategy to load Au nanoparticles (NPs) and DOX, named QCDA, for the synergistic therapy of CT/CDT/PTT. The results showed that QCDA exhibited GSH-sensitive degradation and “cargos” release in cancer cells, and then PTT and CDT caused by Au NPs and Cu+ significantly enhanced the CT effect of DOX and Quercetin on anticancer. More importantly, the PTT and depleted GSH accelerated the Fenton-like ionization process resulting in facilitating the CDT efficiency. Collectively, the multi-mode synergistic strategy of CT/CDT/PTT, which showed an excellent therapeutic effect, maybe a potential therapeutic pathway for anticancer.
Evaluation of How Methacrylate Gelatin Hydrogel Loaded with Ximenia americana L. Extract (Steam Bark) Effects Bone Repair Activity Using Rats as Models
Authors: Leal Seânia Santos , Gusmão Gustavo Oliveira de Meira , Uchôa Valdiléia Teixeira , Figueiredo-Silva José , Pinto Lucielma Salmito Soares , Tim Carla R. , Assis Lívia , Maia-Filho Antonio Luiz Martins , Oliveira Rauirys Alencar de , Lobo Anderson Oliveira , Pavinatto Adriana
Published: August 2023

The use of bioactive materials, such as Ximenia americana L., to stimulate the bone repair process has already been studied; however, the synergistic effects of its association with light emitting diode (LED) have not been reported. The present work aims to evaluate the effect of its stem bark extract incorporated into methacrylate gelatin hydrogel (GelMA) on the bone repair process using pure hydrogel and hydrogel associated with LED therapy. For this purpose, the GelMA hydrogel loaded with Ximenia americana L. extract (steam bark) was produced, characterized and applied in animal experiments. The tests were performed using 50 male Wistar rats (divided into 5 groups) submitted to an induced tibia diaphyseal fracture. The therapy effects were verified for a period of 15 and 30 days of treatment using histological analysis and Raman spectroscopy. After 15 days of induced lesion/treatment, the new bone formation was significantly higher in the GXG (GelMA + X. americana L.) group compared to the control group (p < 0.0001). After 30 days, a statistically significant difference was observed when comparing the GXLEDG (GelMA + X. americana L. + LED) and the control group (p < 0.0001), the GXG and the control group (p < 0.001), and when comparing the GG, GXG (p < 0.005) and GXLEDG (p < 0.001) groups. The results shows that the Ximenia americana L. stem extract incorporated into GelMA hydrogel associated with LED therapy is a potentiator for animal bone repair.
A Newly Proposed Method for Hydrogen Storage in a Metal Hydride Storage Tank Intended for Maritime and Inland Shipping
Authors: Lázár Marián , Mihálik Ivan , Brestovič Tomáš , Jasminská Natália , Tóth Lukáš , Dobáková Romana , Duda Filip , Kmeťová Ľubomíra , Hudák Šimon
Published: August 2023

The utilisation of hydrogen in ships has important potential in terms of achieving the decarbonisation of waterway transport, which produces approximately 3% of the world’s total emissions. However, the utilisation of hydrogen drives in maritime and inland shipping is conditioned by the efficient and safe storage of hydrogen as an energy carrier on ship decks. Regardless of the type, the constructional design and the purpose of the aforesaid vessels, the preferred method for hydrogen storage on ships is currently high-pressure storage, with an operating pressure of the fuel storage tanks amounting to tens of MPa. Alternative methods for hydrogen storage include storing the hydrogen in its liquid form, or in hydrides as adsorbed hydrogen and reformed fuels. In the present article, a method for hydrogen storage in metal hydrides is discussed, particularly in a certified low-pressure metal hydride storage tank—the MNTZV-159. The article also analyses the 2D heat conduction in a transversal cross-section of the MNTZV-159 storage tank, for the purpose of creating a final design of the shape of a heat exchanger (intensifier) that will help to shorten the total time of hydrogen absorption into the alloy, i.e., the filling process. Based on the performed 3D calculations for heat conduction, the optimisation and implementation of the intensifier into the internal volume of a metal hydride alloy will increase the performance efficiency of the shell heat exchanger of the MNTZV-159 storage tank. The optimised design increased the cooling power by 46.1%, which shortened the refuelling time by 41% to 2351 s. During that time, the cooling system, which comprised the newly designed internal heat transfer intensifier, was capable of eliminating the total heat from the surface of the storage tank, thus preventing a pressure increase above the allowable value of 30 bar.
A Possible Synergistic Approach: Case Study of Saccharina latissima Extract and Nitrifying Bacteria in Lettuce
Authors: Pacheco Diana , Cotas João , Pereira Leonel , Bahcevandziev Kiril
Published: August 2023

Nowadays, the exponential expansion in human population has resulted in the massification of intensive agricultural practices, with crop yield and sustainability being one of the most pressing challenges. Therefore, there was a need for new and natural fertilizers and pesticides, which has become a popular agricultural trend nowadays. Therefore, there was an increased interest to apply seaweed and bacterial extracts in agriculture to promote new means of sustainability and soil usage. This work aims to test seaweed inclusion in the agricultural field, as a simple or complex foliar biofertilizer solution applied together with a nitrifying bacteria, to verify if there is a potential synergistic effect of these two different types of biofertilizers on economically important vegetables. As a result, experiments were conducted in a greenhouse using an aqueous extract of the brown seaweed Saccharina latissima (1.2% v/v) and a biofertilizer based on BlueN bacteria (0.03% m/v), both simple or in combination, on lettuce (Lactuca sativa L. var. crispa) plants. The seaweed extract (simple or in combination), presented favorable effect on lettuce growth and nutritional properties. The aqueous algal extract, and it in combination with BlueN, produced heavier lettuce leaves (74.25 ± 6.86 and 74.13 ± 3.07 g, respectively) than the controls and enriched leaf micronutrient contents (zinc and manganese). Also, this study demonstrated that a combined seaweed-bacteria fertilizer did not show synergistic behavior, being a non-profitable solution when compared to a simple seaweed extract. In summary, this study demonstrated that simple (crude) seaweed extracts can be considered as an important key for natural plant biofertilizers and growth stimulators concerned with the blue circular economy.
Route Planning of a Polar Cruise Ship Based on the Experimental Prediction of Propulsion Performance in Ice
Authors: Huang Yan , Sun Ce , Sun Jianqiao , Song Zhipeng
Published: August 2023

The effective assessment of risk and speed limitations in ice are critical for the route planning of polar cruise ships. While the Polar Operational Limit Assessment Risk Indexing System (POLARIS) is widely used to evaluate the operational risk in ice, its scope of assessment is limited to the ship’s assigned ice class. For a specific ship with a given ice class, the propulsion performance under varying ice conditions is more essential for assessing the besetting risk and finding an optimal route. To establish a more detailed risk evaluation method for a PC6 class polar cruise ship, propulsion performance under various ice conditions is obtained via model tests in an ice tank. During the tests, the tow force, propeller torque, and thrust are measured under different ship velocities and propeller rotation rates, and the relations between required delivered power (P) and ship velocity (V) under the tested ice thicknesses and concentrations are obtained and extended to other ice conditions by curve fitting. A new risk index outcome, RIO*, is proposed after POLARIS according to the optimized load ranges of the ship’s rated power. Four risk levels, including low, medium, high, and unnavigable, are classified with the required propulsion power in ice being 50%, 85%, 100%, and >100% of the rated power, respectively. The recommended speed limit for each risk level is proposed based on the economical service speed of 11 kn, the operational limit of 3 kn by POLARIS and the minimum speed of 0.5 kn to avoid besetting, respectively. Based on the RIO* and P–V relations, the speed map for varying ice thicknesses and concentrations can be calculated. On these bases, a route planning simulation for the present polar cruise ship is performed. Results of the case study show that 29% of the simulated area is identified as “unnavigable” by the present procedure, while only 8% is detected by POLARIS.
Life Cycle Assessment of a Coastal Concrete Bridge Aided by Non-Destructive Damage Detection Methods
Authors: Hadizadeh-Bazaz Mehrdad , Navarro Ignacio J. , Yepes Víctor
Published: August 2023

Recently, using economic damage identification techniques to ensure the safety of bridges has become essential. But investigating the performance of those techniques for various conditions and environments and, in addition, a life cycle assessment (LCA) through these methods depending on the situation and during the life of a structure could help specialists and engineers in this field. In these regards, analyzing the implementation of a technique for the restoration and maintenance stages of costly structures such as bridges can illustrate the effect of each damage detection method on the LCA. This research assessed non-destructive abilities and a dynamic approach to predict the amount and location of damages in the LCA. For this purpose, the power spectral density (PSD) technique’s performance by different approaches in identifying corrosion damages for a coastal bridge and the effectiveness of using this technique on reducing the environmental impact compared with a conventional method were evaluated. The results demonstrate a reduction of the environmental impacts by approximately 23% when using the PSD during the bridge’s service life. In conclusion, the PSD approach does well in anticipating the damage quantity and location on a coastal bridge, which reduces the environmental impacts during the repair and maintenance.
Underwater Image Enhancement Based on Hybrid Enhanced Generative Adversarial Network
Authors: Xu Danmi , Zhou Jiajia , Liu Yang , Min Xuyu
Published: August 2023

In recent years, underwater image processing has played an essential role in ocean exploration. The complexity of seawater leads to the phenomena of light absorption and scattering, which in turn cause serious image degradation problems, making it difficult to capture high-quality underwater images. A novel underwater image enhancement model based on Hybrid Enhanced Generative Adversarial Network (HEGAN) is proposed in this paper. By designing a Hybrid Underwater Image Synthesis Model (HUISM) based on a physical model and a deep learning method, many richly varied paired underwater images are acquired to compensate for the missing problem of underwater image enhancement dataset training. Meanwhile, the Detection Perception Enhancement Model (DPEM) with Perceptual Loss is designed to transfer the coding knowledge in the form of the gradient to the enhancement model through the perceptual loss, which leads to the generation of visually better and detection-friendly underwater images. Then, the synthesized and enhanced models are integrated into an adversarial network to generate high-quality underwater clear images through game learning. Experiments show that the proposed method significantly outperforms several state-of-the-art methods both qualitatively and quantitatively. Furthermore, it is also demonstrated that the method can improve target detection performance in underwater environments, which has specific application value for subsequent image processing.
Fungal Biotechnology and Applications
Authors: Xu Baojun
Published: August 2023

The demand for fossil fuels for industry, agriculture, transportation, and private sectors is sharply increasing globally [...]
Antibacterial Polyketides Isolated from the Marine-Derived Fungus Fusarium solani 8388
Authors: Lin Cankai , Huang Rongchun , Liu Juntao , Li Hong , Zhu Liping , Huang Xin , Ding Bo , Liu Lan , Huang Hongbo , Tao Yiwen
Published: August 2023

Seven new polyketides named fusarisolins F-K (1–6) and fusarin I (7) were isolated from the marine-derived fungus Fusarium solani 8388, together with the known anhydrojavanicin (8), 5-deoxybostry coidin (9), and scytalol A (10). Their structures were established by comprehensive spectroscopic data analyses, and by comparison of the 1H and 13C NMR data with those reported in literature. Fusarisolin F (1) contained both a dichlorobenzene group and an ethylene oxide unit, which was rare in nature. In the bioassays, fusarisolin I (4), fusarisolin J (5), and 5-deoxybostry coidin (9) exhibited obvious antibacterial activities against methicillin-resistant Staphylococcus aureus n315 with MIC values of 3, 3, and 6 μg/mL, respectively. Fusarisolin H (3) and fusarisolin J (5) showed inhibitory effects against methicillin-resistant Staphylococcus aureus NCTC 10442 with the same MIC value of 6 μg/mL. With the exception of 5, all other compounds did not show or showed weak cytotoxicities against HeLa, A549, and KB cells; while fusarisolin J (5) demonstrated moderate cytotoxicities against the three human cancer cell lines with CC50 values between 9.21 and 14.02 μM.
Comparison of the Severity of Zoster-Associated Pain and Incidence of Postherpetic Neuralgia in Patients with and without Pre-Existing Spinal Disorders at the Same Spinal Nerve Level: A Retrospective Multicenter Study
Authors: Chae Ji Seon , Im Jiwoong , Choi Yong Ju , Lee Hyun Jung , Kim Won-Joong
Published: August 2023

The incidences of herpes zoster (HZ) and postherpetic neuralgia (PHN) are significantly influenced by age. As individuals age, the occurrence of spinal disorders increases, thereby raising the likelihood of HZ and PHN coexistence. Considering this, our study aimed to explore the potential impact of pre-existing spinal disorders at the nerve level where HZ developed, on the severity of zoster-associated pain (ZAP) and the incidence of PHN. For our investigation, we retrospectively analyzed a total of 237 patients who presented with HZ and ZAP at various sensory levels (cervical, thoracic, lumbar, and sacral) with or without pre-existing spinal disorders. The presence or absence of spinal disorders at the sensory level affected by HZ was determined using computed tomography or magnetic resonance imaging. Our study results revealed that the group with spinal disorders at the sensory level where HZ developed did not exhibit an increased incidence of PHN. However, 3–6 months after HZ onset, this same group showed significantly higher ZAP scores compared to the group without spinal disorders. It implies a need for heightened pain management, as the coexistence of these conditions can increase pain severity. This study furnishes an initial standpoint to delve into intricate interactions between two diseases.
HPLC Analysis and Risk Assessment of 15 Priority PAHs in Human Blood Serum of COPD Patient from Urban and Rural Areas, Iasi (Romania)
Authors: Buculei Ioana , Dobrin Mona Elisabeta , Matei Daniela , Onu Ilie , Cioroiu Ionel Bogdan , Caba Bogdan , Postelnicu Mădălina-Gabriela , Buhociu Dragos-Horia , Musat Carmina Liana , Crisan-Dabija Radu , Cernomaz Andrei Tudor , Trofor Antigona Carmen
Published: August 2023

One of the leading risk factors for environmental health problems is air pollution. The World Health Organization (WHO) reports that this risk factor is associated with one of every nine deaths worldwide. Epidemiological studies conducted in this field have shown a solid connection between respiratory pathology and polycyclic aromatic hydrocarbon (PAH) exposure. COPD and asthma are respiratory diseases that were shown to have a strong association with exposure to PAHs. The purpose of the present study was to assess the serum levels of 15 PAHs in 102 COPD patients and to evaluate the results according to the residence environment of the investigated subjects. Analyses were carried out using a high-performance liquid chromatograph Nexera X2—Shimadzu Japan, which was equipped with an LC–30AD pump and an SIL–30AC autosampler. Spiked matrices, procedure blanks, spiked controls, and calibration standards in the acetonitrile were used as quality-assurance samples. Benzo(a)pyrene is the main representative of PAHs and was determined in higher concentrations in subjects with COPD versus the control group from the urban area (0.90/0.47 ng/mL) and rural area (0.73/0.44 ng/mL). The values obtained for the Benzo(a)pyrene-equivalent factor indicate a higher carcinogenic potential for patients diagnosed with COPD in urban areas compared to those in rural areas. These results could be due to traffic and vehicle emissions. This research identifies the need for legislative action to decrease semi-volatile organic compounds, especially PAHs, mainly in urban cities, in order to improve environmental management and health conditions.
Identification and Mechanism of Residents’ Regional Non-Commuting Flow Patterns Based on the Gradient Boosting Decision Tree Model: A Case Study of the Shanghai Metropolitan Area
Authors: Cao Yang , Wang Linxing , Wu Hao , Yan Shuqi , Shen Shuwen
Published: August 2023

With the improvement in residents’ living standards, non-commuting has gradually become an important daily transportation behaviour for residents. The intensity of non-commuting flow can reflect the level of urban functional services and external attractiveness and can intuitively characterise the interconnection pattern and relationship among various cities within the metropolitan area. Related research is also a key topic in the fields of urban planning and transportation geography from a humanistic perspective. Taking the Shanghai Metropolitan Area as an example, this study explored the characteristics of the non-commuting flow of residents in the region and between cities and its nonlinear influencing factors with the help of the mobile phone signalling data and the gradient lifting decision tree model. Three conclusions were identified: first, non-commuting flow within each city in the metropolitan area was concentrated in the central urban area, while non-commuting flow between cities was concentrated in the central urban area of the urban border and strong core cities. Second, the built environment had a nonlinear impact on residents’ non-commuting flow. Different types of large-scale service facilities had different impact mechanisms on non-commuting flow, and public service facilities and transportation infrastructure jointly affected residents’ non-commuting flow. Third, transportation facilities had a more significant impact on the non-commuting flow between cities. Large tourism, cultural, and medical service facilities had a more significant impact on non-commuting flow within cities, with upper or lower thresholds according to the type of facility. The planning strategy needs to conduct targeted planning, regulation, and facility configuration based on the area’s actual needs. In addition, this study identified the characteristics of non-commuter flow differentiation in street towns and the nonlinear impact of the built environment.
Multilingualism as a Functional Element, a Useful Category for the Study of the Construction and Translation of Linguistically Diverse Discourse
Authors: Hurtado-Malillos Lorena
Published: August 2023

This article is a discursive and equivalence-generating study of the use of the multilingual property as a narrative transmission mechanism in audiovisual texts. Specific functions can be constructed and different events and aspects of the plot can be presented through the introduction of linguistic variation and its deliberate application to achieve defined purposes. The analysis is based on functionalist approaches to the study of fiction and translation and on the binary branching classification model of solution types for determining textual problems in translation based on the form these adopt. This article presents the findings of multilingual property identification and translation related to the application of this forms- and functions-based approach. Several classifications of solution types are also developed with representative examples extracted from film and series.
The Possibility of Using Fruit-Bearing Plants of Temperate Climate in the Treatment and Prevention of Diabetes
Authors: Łysiak Grzegorz P. , Szot Iwona
Published: August 2023

Diabetes mellitus is one of the most dangerous metabolic diseases. The incidence of this disease continues to increase and is often associated with severe complications. Plants and natural plant products with a healing effect have been successfully used in the treatment of many disease entities since the beginning of the history of herbalism and medicine. At present, great emphasis is placed on the biodiversity of crops and the replacement of the monoculture production system of popular temperate climate plants, such as apple, pear, plum, and vine, with alternative fruit species. Very promising fruit plants are Cornelian cherry (Cornus mas); mulberry (Morus alba); bird cherry (Prunus padus); sour cherry (Prunus cerasus); plants of the genus Amelanchier, Sorbus, and Crategus; medlar (Mespilus germanica); quince (Cydonia oblonga); plants of the genus Vaccinium; and wild roses. When promoting the cultivation of alternative fruit-bearing plants, it is worth emphasizing their beneficial effects on health. This systematic review indicates that the antidiabetic effect of various parts of fruit plants is attributed to the presence of polyphenols, especially anthocyanins, which have different mechanisms of antidiabetic action and can be used in the treatment of diabetes and various complications associated with this disease.
The Role of the CuCl Active Complex in the Stereoselectivity of the Salt-Induced Peptide Formation Reaction: Insights from Density Functional Theory Calculations
Authors: Fox Allison C. , Boettger Jason D. , Berger Eve L. , Burton Aaron S.
Published: August 2023

The salt-induced peptide formation (SIPF) reaction is a prebiotically plausible mechanism for the spontaneous polymerization of amino acids into peptides on early Earth. Experimental investigations of the SIPF reaction have found that in certain conditions, the l enantiomer is more reactive than the d enantiomer, indicating its potential role in the rise of biohomochirality. Previous work hypothesized that the distortion of the CuCl active complex toward a tetrahedral-like structure increases the central chirality on the Cu ion, which amplifies the inherent parity-violating energy differences between l- and d-amino acid enantiomers, leading to stereoselectivity. Computational evaluations of this theory have been limited to the protonated–neutral l + l forms of the CuCl active complex. Here, density functional theory methods were used to compare the energies and geometries of the homochiral (l + l and d + d) and heterochiral (l + d) CuCl–amino acid complexes for both the positive–neutral and neutral–neutral forms for alanine, valine, and proline. Significant energy differences were not observed between different chiral active complexes (i.e., d + d, l + l vs. l + d), and the distortions of active complexes between stereoselective systems and non-selective systems were not consistent, indicating that the geometry of the active complex is not the primary driver of the observed stereoselectivity of the SIPF reaction.
Prediction of Thrust Force and Torque for High-Speed Drilling of AL6061 with TMPTO-Based Bio-Lubricants Using Machine Learning
Authors: Kathmore Pramod , Bachchhav Bhanudas , Nandi Somnath , Salunkhe Sachin , Chandrakumar Palanisamy , Nasr Emad Abouel , Kamrani Ali
Published: August 2023

This study was designed to examine the effects of a trimethylolpropane trioleate (TMPTO)-based lubricant on thrust force and torque under the high-speed drilling of Al-6061 as an effective environmentally friendly cutting fluid. The tribological performance of three lubricant blends was evaluated based on ASTM standards. TMPTO base oil, notably enhances load-carrying capacity under extreme pressure conditions, with a seizer load of 7848 N. The best-performing oil was further optimized using a Taguchi-based design experiment to investigate the effect of different additive concentrations on thrust force and torque under actual contact conditions. Experiments were conducted using three critical machining parameters: additive concentration, spindle speed, and feed rate. The results of the ANOVA analysis reveal that spindle speed contributes most substantially (62.99%) to torque, with feed rate (23.72%) and additive concentration (7.74%) also showing significant impacts. On the other hand, thrust force is primarily influenced by feed rate (73.52%), followed by spindle speed (16.82%), and additive concentration (6.28%). Furthermore, a machine learning model was developed to predict and compare a few significant aspects of high-speed drilling machinability, including thrust force and torque. Three different error metrics were utilized in order to assess the performance of the predicted values, namely the coefficient of determination (R2), mean absolute percentage error (MAPE) and mean square error (MSE), which are all based on the coefficient of determination. Compared to other models, decision tree produces more accurate prediction values for cutting forces. The present study provides a novel approach for evaluating the most promising biodegradable lube oils and predicting cutting forces by formulating a perfect blend.
Research on Oil–Gas Two-Phase Flow Characteristics and Improvement of Aero-Engine Bearing Chamber
Authors: Ren Guozhe , Li Yanpeng , Zhao Huan , Yan Yang , Xu Wenfeng , Sun Dan
Published: August 2023

In order to study the oil–gas two-phase flow characteristics of an aero-engine bearing chamber and improve the scavenge effect of lubricating oil, the two-phase flow solution model of a bearing chamber based on the Euler–Euler method was established. Three improvement schemes were proposed for the ventilation structure and scavenge structure of the bearing chamber. The flow characteristics and scavenge characteristics of a conventional bearing chamber and three improvement schemes under different working conditions were analyzed in depth. The results show that after the conventional bearing chamber ventilation structure is embedded (Embed) and improved, with the increase in the embedding depth, the oil in the cavity is further blocked in the cavity, the amount of oil flowing out from the vent is further reduced, and the scavenge efficiency is further improved. After the slope improvement of the scavenge structure of the conventional bearing chamber, due to the increase in the depth of the oil return groove, the drag effect of the air shear force in the cavity on the oil in the oil return groove is further weakened, and the oil accumulation area on the right side of the scavenge port is further suppressed. The volume fraction of the oil in the cavity is further reduced, and the scavenge efficiency is further improved. The combined improvement scheme (ES) can take into account the advantages of embedding and slope improvement schemes, and further improve the scavenge efficiency. Compared to the conventional bearing chamber, when the oil flow rate is 200 L/h and the speed is 15,000 r/min, the oil return efficiency of the embedded (h = 12 mm), slope (l = 56 mm) and combined improvement schemes are increased by 20.19%, 13.43%, and 37.94%, respectively.
Efficient Synthesis of 2-Ethylhexanoic Acid via N-Hydroxyphthalimide Catalyzed Oxidation of 2-Ethylhexanal with Oxygen
Authors: Czieszowic Łukasz , Orlińska Beata , Lisicki Dawid , Pankalla Ewa
Published: August 2023

An efficient method for the synthesis of 2-ethylhexanoic acid has been reported. The method involves the 2-ethylhexanal oxidation using oxygen or air in the presence of N-hydroxyphthalimide in isobutanol as a solvent under mild conditions. A high selectivity of >99% for 2-ethylhexanoic acid was achieved. The influence of catalyst amount, solvent type and quantity, temperature, and reaction time on the product composition was studied. The developed method is in line with the global trends aimed at developing green oxidation processes as well as having potential for implementation in industry due to its high selectivity, cost-effective oxidizing agent, and mild reaction conditions. The use of isobutanol as a solvent is of crucial importance providing an opportunity for potential producers of 2-EHAL from butanal to employ the less valuable alcohol.
Effect of Target Power on Microstructure, Tribological Performance and Biocompatibility of Magnetron Sputtered Amorphous Carbon Coatings
Authors: Dhandapani Vishnu Shankar , Subbiah Ramesh , Thangavel Elangovan , Kim Chang-Lae , Kang Kyoung-Mo , Veeraraghavan Veeravazhuthi , Park Kwideok , Kim Dae-Eun , Park Dongkyou , Kim Byungki
Published: August 2023

The tribological properties and preosteoblast behavior of an RF magnetron-sputtered amorphous carbon coating on a Si (100) substrate were evaluated. The graphite target power was varied from 200 to 500 W to obtain various coating structures. The amorphous nature of the coatings was confirmed via Raman analysis. The contact angle also increased from 58º to 103º, which confirmed the transformation of the a-C surface from a hydrophilic to hydrophobic nature with an increasing graphite target power. A minimum wear rate of about 4.73 × 10−8 mm3/N*mm was obtained for an a-C coating deposited at a 300 W target power. The 300 W and 400 W target power coatings possessed good tribological properties, and the 500 W coating possessed better cell viability and adhesion on the substrate. The results suggest that the microstructure, wettability, tribological behavior and biocompatibility of the a-C coating were highly dependent on the target power of the graphite. A Finite Element Analysis (FEA) showed a considerable increase in the Von Mises stress as the mesh size decreased. Considering both the cell viability and tribological properties, the 400 W target power coating was identified to have the best tribological property as well as biocompatibility.
Lead Chalcogenide Colloidal Quantum Dots for Infrared Photodetectors
Authors: Zhao Xue , Ma Haifei , Cai Hongxing , Wei Zhipeng , Bi Ying , Tang Xin , Qin Tianling
Published: August 2023

Infrared detection technology plays an important role in remote sensing, imaging, monitoring, and other fields. So far, most infrared photodetectors are based on InGaAs and HgCdTe materials, which are limited by high fabrication costs, complex production processes, and poor compatibility with silicon-based readout integrated circuits. This hinders the wider application of infrared detection technology. Therefore, reducing the cost of high-performance photodetectors is a research focus. Colloidal quantum dot photodetectors have the advantages of solution processing, low cost, and good compatibility with silicon-based substrates. In this paper, we summarize the recent development of infrared photodetectors based on mainstream lead chalcogenide colloidal quantum dots.
A Novel Multi-Scale Ceramic-Based Array (SiCb+B4Cp)/7075Al as Promising Materials for Armor Structure
Authors: Luo Tian , Chao Zhenlong , Du Shanqi , Jiang Longtao , Chen Shengpeng , Zhang Runwei , Han Huimin , Han Bingzhuo , Wang Zhiwei , Chen Guoqin , Mei Yong
Published: August 2023

Ceramic panel collapse will easily lead to the failure of traditional targets. One strategy to solve this problem is to use separate ceramic units as armor panels. Based on this idea, we propose an aluminum matrix composite using pressure infiltration, containing an array of ceramic balls, the reinforcement of which consists of centimeter-scale SiC balls and micron-scale B4C particles. Three different array layouts were designed and fabricated: compact balls in the front panel (F-C), non-compact balls in the front panel (F-NC), and compact balls inside the target (I-C). The penetration resistance properties were tested using a 12.7 mm armor-piercing incendiary (API). The results show that there are no significant internal defects, and the ceramic balls are well-bonded with the matrix composite. The F-NC structure behaves the best penetration resistance with minimal overall damage; the I-C structure has a large area of spalling and the most serious damage. Finite element simulation reveals that the ceramic balls play a major role in projectile erosion; in the non-compact structure, the composite materials between the ceramic balls can effectively disperse the stress, thereby avoiding the damage caused by direct contact between ceramic balls and improving the efficiency of ceramic ball erosion projectiles. Furthermore, it is essential to have a certain thickness of supporting materials to prevent spalling failure caused by stress wave transmission during penetration. This multi-scale composite exhibits excellent ballistic performance, providing valuable insights for developing anti-penetration composite armor in future applications.
Advanced Injection Molding Methods: Review
Authors: Czepiel Mateusz , Bańkosz Magdalena , Sobczak-Kupiec Agnieszka
Published: August 2023

Injection molding is a method commonly used to manufacture plastic products. This technology makes it possible to obtain products of specially designed shape and size. In addition, the developed mold allows for repeated and repeatable production of selected plastic parts. Over the years, this technology grew in importance, and nowadays, products produced by injection molding are used in almost every field of industry. This paper is a review and provides information on recent research reports in the field of modern injection molding techniques. Selected plastics most commonly processed by this technique are discussed. Next, the chosen types of this technique are presented, along with a discussion of the parameters that affect performance and process flow. Depending on the proposed method, the influence of various factors on the quality and yield of the obtained products was analyzed. Nowadays, the link between these two properties is extremely important. The work presented in the article refers to research aimed at modifying injection molding methods enabling high product quality with high productivity at the same time. An important role is also played by lowering production costs and reducing the negative impact on the environment. The review discusses modern injection molding technologies, the development of which is constantly progressing. Finally, the impact of the technology on the ecological environment is discussed and the perspectives of the process were presented.
On the Selectivity of Simultaneous CO2 and N2 Reduction Using TiO2/Carbon Sphere Photocatalysts Prepared by Microwave Treatment and Mounted on Silica Cloth
Authors: Kusiak-Nejman Ewelina , Ćmielewska Katarzyna , Pełech Iwona , Ekiert Ewa , Staciwa Piotr , Sibera Daniel , Wanag Agnieszka , Kapica-Kozar Joanna , Gano Marcin , Narkiewicz Urszula , Morawski Antoni W.
Published: August 2023

This paper presents new photocatalysts obtained by treating carbon spheres (CS) and TiO2 in a microwave reactor at a pressure of 20 atm and a temperature of up to 300 °C for 15 min and then depositing TiO2/CS composites on glass fibre cloths. Such highly CO2-adsorbing photocatalysts showed photoactivity in the simultaneous water-splitting process, generating H2, reducing CO2 to CO and CH4, and reducing N2 to NH3. In addition, calculations of the hydrogen balance involved in all reactions were performed. Adding 1 g of carbon spheres per 1 g of TiO2 maintained the high selectivity of nitrogen fixation at 95.87–99.5%, which was continuously removed from the gas phase into the water as NH4+ ions.
Application of an Optimal Control Therapeutic Approach for the Memory-Regulated Infection Mechanism of Leprosy through Caputo–Fabrizio Fractional Derivative
Authors: Cao Xianbing , Ghosh Salil , Rana Sourav , Bose Homagnic , Roy Priti Kumar
Published: August 2023

Leprosy (Hansen’s disease) is an infectious, neglected tropical skin disease caused by the bacterium Mycobacterium leprae (M. leprae). It is crucial to note that the dynamic behavior of any living microorganism such as M. leprae not only depends on the conditions of its current state (e.g., substrate concentration, medium condition, etc.) but also on those of its previous states. In this article, we have developed a three-dimensional mathematical model involving concentrations of healthy Schwann cells, infected Schwann cells, and M. leprae bacteria in order to predict the dynamic changes in the cells during the disease dissemination process; additionally, we investigated the effect of memory on system cell populations, especially on the M. leprae bacterial population, by analyzing the Caputo–Fabrizio fractionalized version of the model. Most importantly, we developed and investigated a fractionalized optimal-control-induced system comprising the combined drug dose therapy of Ofloxacin and Dapsone intended to achieve a more realistic treatment regime for leprosy. The main goal of our research article is to compare this fractional-order system with the corresponding integer-order model and also to distinguish the rich dynamics exhibited by the optimal-control-induced system based on different values of the fractional order ζ∈(0,1). All of the analytical results are validated through proper numerical simulations and are compared with some real clinical data.
Bounds on Performance for Recovery of Corrupted Labels in Supervised Learning: A Finite Query-Testing Approach
Authors: Seong Jin-Taek
Published: August 2023

Label corruption leads to a significant challenge in supervised learning, particularly in deep neural networks. This paper considers recovering a small corrupted subset of data samples which are typically caused by non-expert sources, such as automatic classifiers. Our aim is to recover the corrupted data samples by exploiting a finite query-testing system as an additional expert. The task involves identifying the corrupted data samples with minimal expert queries and finding them to their true label values. The proposed query-testing system uses a random selection of a subset of data samples and utilizes finite field operations to construct combined responses. In this paper, we demonstrate an information-theoretic lower bound on the minimum number of queries required for recovering corrupted labels. The lower bound can be represented as a function of joint entropy with an imbalanced rate of data samples and mislabeled probability. In addition, we find an upper bound on the error probability using maximum a posteriori decoding.
An Efficient and Secure Fog Based Routing Mechanism in IoT Network
Authors: Malik Tauqeer Safdar , Tanveer Jawad , Anwar Shahid , Mufti Muhammad Rafiq , Afzal Humaira , Kim Ajung
Published: August 2023

The Internet of Things (IoT) networks are the most prone to internal as well as external attacks in addition to energy consumption problems. Conventional security solutions are not able to address these issues effectively due to the limited resources of sensor nodes participating in IoT communications. In this work, an Efficient and Secure Fog Based Routing Mechanism (ESFRM) is proposed to protect the network from faulty internal as well as external attacks. Every node participating in IoT communications calculates the comprehensive trust value of the next intermediate node which is the addition of direct trust, indirect trust and energy trust values before forwarding the data. This comprehensive trust value is then compared with the comprehensive threshold trust value to decide whether the particular node is a rogue node or a valid normal node. Further, an enhanced RSA (Rivest, Shamir, Adleman) algorithm is implemented to provide three levels of data security from Cluster Head (CH) to fog node, from fog node to cloud server and directly from CH to cloud server. For this purpose, an efficient CH selection technique is also proposed in this work. The proposed methodology is compared with the Secure Energy-efficient Fog-based Routing (SEFR) protocol and Trust-aware Secure Routing Protocol (TSRP). The evaluation results show that the proposed ESFRM outperforms the conventional schemes with respect to energy consumption, malicious node detection and transmission rate.
A Dynamic Network Loading Model for Hub Station Pedestrian Flow Collection and Distribution
Authors: Zheng Weihao , Mou Ruifang
Published: August 2023

A macro network loading model for multi-flow lines, time varying, and pedestrian congestion is proposed. The station hub is abstracted as a network of different types of nodes, and the flow of passengers at each node is calculated in real time for the purpose of simulating the hub’s collection and distribution process. For correct transmission of passenger flow on heterogeneous networks, three types of indexes are proposed to distinguish the nodes, and the corresponding fundamental diagrams are then matched. This paper divides the update process of the dynamic network loading model into multiple processes by flow lines, and improves the computational speed of the DNL model. The proposed model is applied to the simulation of passenger flow collection and distribution in an actual hub station with multi-flow lines. The analysis results illustrate that the model can accurately reflect the realistic congestion facilities and explain the formation process of high-density areas. A rolling passenger flow control model based on optimal control theory is proposed. The effectiveness of the control model is verified based on simulation data.
Representations by Beurling Systems
Authors: Kazarian Kazaros
Published: August 2023

We prove that a Beurling system with F∈Hp(D),1≤p<∞ is an M—basis in Hp(D) with an explicit dual system. Any function f∈Hp(D),1≤p<∞ can be expanded as a series by the system {zmF(z)}m=0∞. For different summation methods, we characterize the outer functions F for which the expansion with respect to the corresponding Beurling system converges to f. Related results for weighted Hardy spaces in the unit disc are studied. Particularly we prove Rosenblum’s hypothesis.