bluuebunny/crossref_metadata_2025 huggingface dataset:
Preventing Growth Stagnation and Premature LH Surge Are the Keys to Obtaining a Viable Embryo in Monofollicular IVF Cycles: A Retrospective Cohort Study
Authors: Guo Xiaoyan , Zhu Xiaoping , Wu Xiangli , Yu Yiqi , Zhang Ling , Shu Jing
Published: December 2022

How LH levels influenced the outcomes of monofollicular IVF cycles using different stimulation protocols was controversial. In this single-center, retrospective study, we analyzed 815 monofollicular IVF cycles between 2016–2022 using natural cycle (NC), medroxyprogesterone acetate (MPA) or clomiphene citrate (CC) in addition to human menopausal gonadotropin (hMG), with or without GnRH antagonist. A viable embryo was obtained in 35.7% of all cycles. Growth stagnation and premature LH surge are two markedly negative factors for obtaining viable embryos (odds ratios of 0.12 [0.08–0.65], p < 0.0001 and 0.33 [0.26,0.42], p < 0.0001, respectively). NC/hMG cycles are prone to premature LH surge (40.4%), yielding a significantly lower opportunity of obtaining embryos (24.7%, p = 0.029). The administration of GnRH antagonist on the background of MPA resulted in a significant decrease in LH levels (from 2.26 IU/L to −0.89 IU/L relative to baseline, p = 0.000214), leading to a higher risk of growth stagnation (18.6%, p = 0.007). We hypothesized that the abrupt decline of LH might increase the risk of apoptosis in granulosa cells. We proposed a “marginal effect” framework to emphasize that the change of LH was the key to its bioactivity, rather than the traditional “window” concept with fixed cutoff values of a threshold and a ceiling.
Salivary Biomarkers in Periodontitis Post Scaling and Root Planing
Authors: Priya K. Lakshmi , Mahendra Jaideep , Mahendra Little , Kanakamedala Anilkumar , Alsharif Khalaf F. , Mugri Maryam H. , Varadarajan Saranya , Alamoudi Ahmed , Hassan Ali Abdel-Halim Abdel-Azim , Alnfiai Mrim M. , Alzahrani Khalid J. , Bahammam Maha A. , Baeshen Hosam Ali , Balaji Thodur Madapusi , Bhandi Shilpa
Published: December 2022

Objectives: This study was conducted to evaluate the levels of salivary uric acid and arginase in patients with periodontitis, generalized gingivitis, and in healthy individuals. Then, the effects of non-surgical periodontal therapy on levels of salivary arginase and uric acid were also investigated. Methods: A total of 60 subjects were divided into three groups based on periodontal health: group I comprised 20 healthy individuals; group II comprised 20 subjects who had generalized gingivitis; group III comprised 20 subjects who had generalized periodontitis. On day 0, the clinical examination of periodontal status was recorded, following which saliva samples were collected. Group II and group III subjects underwent non-surgical periodontal therapy. These patients were recalled on day 30 to collect saliva samples. The periodontal parameters were reassessed on day 90, and saliva samples were collected for analysis of salivary arginase and uric acid levels. Results: Group II and group III showed improvement in clinical parameters following non-surgical periodontal therapy on the 90th day. The MGI score, PPD, and CAL showed improvement. On day 0, at baseline, salivary arginase levels in group III and group II were higher than those in healthy subjects, whereas on day 0, salivary uric acid levels in group III and group II were lower than those in healthy subjects. Both on day 0 and day 90, the salivary arginase level showed a positive correlation with the periodontal parameters, whereas the salivary uric acid level was positively correlated with the periodontal parameters on day 90. Conclusion: the level of salivary arginase was a pro-inflammatory marker and a raised level of salivary uric acid was an anti-inflammatory marker following periodontal therapy, suggesting their pivotal role in assessing periodontal status and evaluation of treatment outcome.
Evaluation of an Injectable Biphasic Calcium Sulfate/Hydroxyapatite Cement for the Augmentation of Fenestrated Pedicle Screws in Osteoporotic Vertebrae: A Biomechanical Cadaver Study
Authors: Tian Xinggui , Raina Deepak B. , Vater Corina , Kilian David , Ahlfeld Tilman , Platzek Ivan , Nimtschke Ute , Tägil Magnus , Lidgren Lars , Thomas Alexander , Platz Uwe , Schaser Klaus-Dieter , Disch Alexander C. , Zwingenberger Stefan
Published: December 2022

Cement augmentation of pedicle screws is one of the most promising approaches to enhance the anchoring of screws in the osteoporotic spine. To date, there is no ideal cement for pedicle screw augmentation. The purpose of this study was to investigate whether an injectable, bioactive, and degradable calcium sulfate/hydroxyapatite (CaS/HA) cement could increase the maximum pull-out force of pedicle screws in osteoporotic vertebrae. Herein, 17 osteoporotic thoracic and lumbar vertebrae were obtained from a single fresh-frozen human cadaver and instrumented with fenestrated pedicle screws. The right screw in each vertebra was augmented with CaS/HA cement and the un-augmented left side served as a paired control. The cement distribution, interdigitation ability, and cement leakage were evaluated using radiographs. Furthermore, pull-out testing was used to evaluate the immediate mechanical effect of CaS/HA augmentation on the pedicle screws. The CaS/HA cement presented good distribution and interdigitation ability without leakage into the spinal canal. Augmentation significantly enhanced the maximum pull-out force of the pedicle screw in which the augmented side was 39.0% higher than the pedicle-screw-alone side. Therefore, the novel biodegradable biphasic CaS/HA cement could be a promising material for pedicle screw augmentation in the osteoporotic spine.
A Regional Observational Study on COVID-19-Associated Pulmonary Aspergillosis (CAPA) within Intensive Care Unit: Trying to Break the Mold
Authors: Lupia Tommaso , Montrucchio Giorgia , Gaviraghi Alberto , Musso Gaia , Puppo Mattia , Bolla Cesare , Shbaklo Nour , Rizzello Barbara , Della Selva Andrea , Concialdi Erika , Rumbolo Francesca , Barbui Anna Maria , Brazzi Luca , De Rosa Francesco Giuseppe , Corcione Silvia
Published: December 2022

The reported incidence of COVID-19-associated pulmonary aspergillosis (CAPA) ranges between 2.4% and 35% in intensive care unit (ICU) patients, and awareness in the medical community is rising. We performed a regional retrospective observational study including patients diagnosed with CAPA defined according to the Modified AspICU Dutch/Belgian Mycosis Study Group and CAPA–EECMM, from five different ICUs, admitted between March, 2020 and September, 2021. Forty-five patients were included. The median age was 64 (IQR 60–72), mostly (73%) males. At ICU admission, the median Charlson comorbidity index was 3 (2–5), and the simplified acute physiology score (SAPS)-II score was 42 (31–56). The main underlying diseases were hypertension (46%), diabetes (36%) and pulmonary diseases (15%). CAPA was diagnosed within a median of 17 days (IQR 10–21.75) after symptoms onset and 9 days (IQR 3–11) after ICU admission. The overall 28-day mortality rate was 58%, and at univariate analysis, it was significantly associated with older age (p = 0.009) and SAPS-II score at admission (p = 0.032). The use of immunomodulatory agents, p = 0.061; broad-spectrum antibiotics, p = 0.091; positive culture for Aspergillus on BAL, p = 0.065; and hypertension, p = 0.083, were near reaching statistical significance. None of them were confirmed in multivariate analysis. In critically ill COVID-19 patients, CAPA acquired clinical relevance in terms of incidence and reported mortality. However, the risk between underdiagnosis—in the absence of specific invasive investigations, and with a consequent possible increase in mortality—and over-diagnosis (case identification with galactomannan on broncho-alveolar fluid alone) might be considered. Realistic incidence rates, based on local, real-life epidemiological data, might be helpful in guiding clinicians.
The Impact of Climate Change and Grain Planting Structure Change on Irrigation Water Requirement for Main Grain Crops in Mainland China
Authors: Wang Jiayue , Xin Liangjie , Wang Xue , Jiang Min
Published: December 2022

To understand the change in irrigation water requirement (IWR) in China under the changing climate conditions and grain planting structures, this paper focused on rice, wheat and maize and analyzed the IWR change in each county under the background of climate change and the adjustment of planting structure by means of the China Agro-Ecological Zones (China-AEZ) model. The results show that: (1) Climate change causes the increase of IWR. Compared with the 1961–1990 period, the average IWR of counties in China increased by 9.31 mm and 16.50% under the climate conditions of the 1981–2010 period. Regionally, the water consumption effect of climate change is stronger in water-poor areas than in water-rich areas. (2) Planting structure change causes the decrease of IWR. Compared with 1990, under the planting structure in 2014, the average IWR of counties in China decreased by 6.61 mm and 11.41%. Regionally, the water-saving effect of the change in planting structure in the north is stronger than that in the south. (3) With the change in climate conditions and planting structure, the average IWR of counties in China first increased and then decreased, with an overall increase of 2.06 mm and 3.56%. Regionally, the IWR in most parts of the country has shown a decreasing trend, while the IWR in northwestern and north China, where water resources are relatively scarce, has increased significantly. (4) Nationally, the change in IWR is dominated by climate change, and the overall trend is in the direction of water consumption. Therefore, adjusting the crop planting structure is a promising way to save irrigation water. To adapt to the pressures on water resources caused by climate change, the proportion of crops with water-saving advantages should be increased in the corresponding areas to achieve regional water savings. In northwest China, which mainly relies on irrigation water, many crops with low IWR should be planted, such as wheat and maize, while the planting proportion of rice should be reduced; furthermore, the planting proportion of wheat should be reduced, and the planting proportion of maize should be increased in north China. Finally, rice with high IWR should be more localized in central, southern and northeastern China.
Developing Management Practices in: “Living Labs” That Result in Healthy Soils for the Future, Contributing to Sustainable Development
Authors: Bouma J. , Veerman C. P.
Published: December 2022

There is general agreement on the need for sustainable development, but the concept has remained rather vague until seventeen specific goals (SDGs) were approved by the UN Assembly in 2015, including targets and indicators. The EU followed this example by introducing their Green Deal in 2019. Soils play a very important role in realizing these goals by the intended year of 2030 in terms of (amongst other less directly related goals) contributing to food production (SDG2: “zero hunger”), good health and wellbeing (SDG3), water quality (SDG6: “clean water and sanitation”), sustainable production (SDG12: ”sustainable consumption and production”), carbon capture and greenhouse gas emission (SDG13: “climate action”) and soil health and biodiversity preservation (SDG15: “life on land”). Of course, not only soils but many other scientific disciplines contribute to achieving the SDGs, and the EU Mission Board for Soil Health and Food has, therefore, defined soil health in terms of specific soil contributions to interdisciplinary ecosystem services: “soils supporting ecosystem services in line with the SDGs and the Green Deal”. Restricting attention in this paper to soils, the Board has defined six indicators for soil health that allow an integrated assessment of the role of soils, reported in this paper in a slightly modified version: presence of soil pollutants, organic matter content, structure, biodiversity, nutrient content and water regimes. Currently, different indicator systems are being used while soil research is rather fragmented, as future environmental policies are still being discussed. The research and policy arenas face major challenges at this point in time to rise to the occasion by defining clear operational assessment procedures for soil health that will, above all, be accepted and internalized by land users, of which farmers manage the largest land area. Only then can implementation be realized in practice. An effort is needed to test the vast body of existing techniques and expertise and focus new research on gaps that appear. This is discussed in detail for the six indicators distinguished, and particular attention is paid to defining threshold values, separating the “good” from the “not yet good enough”. New ways have to be explored to achieve real and productive interactions between scientists and stakeholders, including farmers. The establishment of Living Labs aimed at realizing successful Lighthouses is, therefore, seen as an effective way for scientists to work with farmers in developing innovative management schemes, including the role of soils, expressed in terms of indicators and thresholds for soil health. Such procedures should be the basis for future rules and regulations, where a “one-out, all-out” principle can be used for the various indicators to avoid the current complex discussions about deriving a single, overall soil health indicator.
Does Japanese/German L1 Metrical and Tonal Structure Constrain the Acquisition of French L2 Morphology?
Authors: Granget Cyrille , Delais-Roussarie Elisabeth
Published: December 2022

In different studies dedicated to the acquisition of verbal morphology by bilingual children or by L2 learners, it has been noted that differences in the acquisition process cannot be accounted for by only considering the distance between L1 and L2 morphology. Some forms, such as auxiliaries, may occur in L2 productions without being motivated by L1 morphology. To account for this, the prosodic transfer hypothesis—according to which the acquisition of morphology in the non-dominant language is influenced by the prosody of the dominant language—has been formulated. That prosodic features may influence the acquisition of morphology is interesting as it shows that the acquisition process must be apprehended by considering interfaces and interrelations between the various levels of linguistic description. The aim of this contribution is thus twofold: (i) clarifying to which aspects of prosody prosodic transfer hypothesis refers (specifically, among tonal and metrical prosodic elements, which one comes into play to account for morphological development); and (ii) explaining the importance of considering grammatical interfaces in study on L2 development. To do so, an exploratory study, which relies on the analysis of L2 French narratives produced by two learners with L1 Japanese and two with L1 German, was achieved. This preliminary analysis of the data suggests that metrical structure—more precisely, the nature of the basic metrical unit—may constrain the occurrence of auxiliary and vowel-final forms in the productions of Japanese learners.
A Narrative Review of Sex and Gender Differences in Sleep Disordered Breathing: Gaps and Opportunities
Authors: Bublitz Margaret , Adra Nour , Hijazi Leen , Shaib Fidaa , Attarian Hrayr , Bourjeily Ghada
Published: December 2022

Introduction: Sleep disordered breathing (SDB) is a common condition, associated with multiple comorbidities including cardiovascular and metabolic disease. It has been previously established that SDB is more prevalent in men than women, shifting the literature’s focus away from the latter population. As such, underdiagnosis, and thus undertreatment, of SDB in women exists. Methods: To establish the differences in prevalence, clinical presentation, and pathophysiology of SDB between the two sexes, a narrative review of the current literature was performed. Results: Rates of SDB are higher among men, likely driven by differences in symptom presentation between men and women, with women presenting with more “atypical” symptoms, and lack of sensitivity in SDB screening tools to detect SDB in women. In addition to the cardiovascular risks of SDB, women with SDB may have worse quality of life, higher prevalence of insomnia, and respiratory issues. Discussion: More research is needed to better define the unique pathophysiology and clinical presentation of SDB in women. In addition, an increased awareness among health care providers and the lay public of the SDB-specific sex and gender differences will serve to minimize disparities in identification and treatment of SDB in women.
Physicochemical Properties of Water-Based Copolymer and Zeolite Composite Sustained-Release Membrane Materials
Authors: Sun Haonan , Lei Tao , Liu Jianxin , Guo Xianghong , Lv Jiangjian
Published: December 2022

A nitrogen fertilizer slow-release membrane was proposed using polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), epoxy resin, and zeolite as raw materials. The effects of the water-based copolymer (PVA:PVP) solution ratio A (A1–A4) and zeolite amount B (B1–B4) on the water absorption rate (XS), water permeability (TS), fertilizer permeability (TF), tensile strength (KL), elongation at break (DSL), and viscosity (ND) of the membrane were explored using the swelling method, a self-made device, and a universal testing machine. The optimal combination of the water-based copolymer and zeolite amount was determined by the coefficient-of-variation method. The results show that the effects of the decrease in A on KL and the increase in B on KL and DSL are promoted first and then inhibited. DSL and ND showed a negative response to the A decrease, whereas XS, TS, and TF showed a positive response. The effect of increasing B on ND, TS, and TF showed a zigzag fluctuation. In the condition of A1–A3, XS showed a negative response to the B increase, whereas in the condition of A4, XS was promoted first and then inhibited. Adding PVP and zeolite caused the hydroxyl stretching vibration peak of PVA at 3300 cm−1 to widen; the former caused the vibration peak to move to low frequencies, and the latter caused it to move to high frequencies. The XRD pattern shows that the highest peak of zeolite is located at 2θ = 7.18° and the crystallization peak of the composite membrane increases with the rise in the proportion of zeolite. Adding PVP made the surface of the membrane smooth and flat, and adding a small amount of zeolite improved the mechanical properties of the membrane and exhibited good compatibility with water-based copolymers. In the evaluation model of the physicochemical properties of sustained-release membrane materials, the weight of all indicators was in the following order: TF > ND > TS > KL > XL > DSL. The optimal membrane material for comprehensive performance was determined to be A2B3.
Synthesis Optimization of BaGdF5:x%Tb3+ Nanophosphors for Tunable Particle Size
Authors: Polyakov Vladimir , Gadzhimagomedova Zaira , Kirsanova Daria , Soldatov Alexander
Published: December 2022

X-ray photodynamic therapy (XPDT) is aimed at the treatment of deep-located malignant tumors thanks to the high penetration depth of X-rays. In XPDT therapy, it is necessary to use materials that effectively absorb X-rays and convert them into visible radiation-nanophosphors. Rare-earth elements, fluorides, in particular, doped BaGdF5, are known to serve as efficient nanophosphor. On the other hand, the particle size of nanophosphors has a crucial impact on biodistribution, cell uptake, and cytotoxicity. In this work, we investigated various Tb:Gd ratios in the range from 0.1 to 0.5 and optimized the terbium content to achieve the maximum luminescence under X-ray excitation. The effect of temperature, composition of the ethylene glycol/water solvent, and the synthesis technique (solvothermal and microwave) on the size of the nanophosphors was explored. It was found that the synthesis techniques and the solvent composition had the greatest influence on the averaged particle size. By varying these two parameters, it is possible to tune the size of the nanophosphor particles, which make them suitable for biomedical applications.
Morphological Effects of Strain Localization in the Elastic Region of Magnetorheological Elastomers
Authors: Johari Mohd Aidy Faizal , Mazlan Saiful Amri , Nordin Nur Azmah , Choi Seung-Bok , Aziz Siti Aishah Abdul , Daud Shaari , Bahiuddin Irfan
Published: December 2022

Strain localization is a significant issue that poses interesting research challenges in viscoelastic materials because it is difficult to accurately predict the damage evolution behavior. Over time, the damage mechanism in the amorphous structure of viscoelastic materials leads to subsequent localization into a shear band, gradually jeopardizing the materials’ elastic sustainability. The primary goal of this study is to further understand the morphological effects and the role of shear bands in viscoelastic materials precipitated by strain localization. The current study aims to consolidate the various failure mechanisms of a sample and its geometry (surface-to-volume ratio) used in torsional testing, as well as to understand their effects on stress relaxation durability performance. A torsional shear load stress relaxation durability test was performed within the elastic region on an isotropic viscoelastic sample made of silicon rubber and a 70% weight fraction of micron-sized carbonyl iron particles. Degradation was caused by a shear band of localized plasticity that developed microscopically due to stress relaxation durability. The failure pattern deteriorated as the surface-to-volume ratio decreased. A field-emission scanning electron microscope (FESEM) and a tapping-mode atomic force microscope (AFM) were used for further observation and investigation of the sample. After at least 7500 cycles of continuous shearing, the elastic sustainability of the viscoelastic materials microstructurally degraded, as indicated by a decline in stress performance over time. Factors influencing the formation of shear bands were observed in postmortem, which was affected by simple micromanipulation of the sample geometry, making it applicable for practical implementation to accommodate any desired performance and micromechanical design applications.
Experimental Design, Equilibrium Modeling and Kinetic Studies on the Adsorption of Methylene Blue by Adsorbent: Activated Carbon from Durian Shell Waste
Authors: Tran Quoc Toan , Đo Tra Huong , Ha Xuan Linh , Duong Thi Tu Anh , Chu Manh Nhuong , Vu Van Nhuong , Chau Hung Dung , Tran Thi Kim Ngan , Song Phomthavongsy
Published: December 2022

For the first time, activated carbon from a durian shell (ACDS) activated by H2SO4 was successfully synthesized in the present study. The fabricated ACDS has a porous surface with a specific surface area of 348.0017 m2·g−1, average capillary volume of 0.153518 cm3·g−1, the average pore diameter of 4.3800 nm; ash level of 55.63%; humidity of 4.74%; density of 0.83 g·cm−3; an iodine index of 634 mg·g−1; and an isoelectric point of 6.03. Several factors affecting Methylene Blue (MB) adsorption capacity of ACDS activated carbon was investigated by the static adsorption method, revealing that the adsorption equilibrium was achieved after 90 min. The best adsorbent pH for MB is 7 and the mass/volume ratio is equal to 2.5 g·L−1. The MB adsorption process of ACDS activated carbon follows the Langmuir, Freundlich, Tempkin, and Elovich isotherm adsorption model, which has determined the maximum adsorption capacity for MB of ACDS as qmax = 57.47 mg·g−1. The MB adsorption process of ACDS follows the of pseudo-second-order adsorption kinetic equation. The Weber and Morris Internal Diffusion Model, the Hameed and Daud External Diffusion Model of liquids have been studied to see if the surface phase plays any role in the adsorption process. The results of thermodynamic calculation of the adsorption process show that the adsorption process is dominated by chemical adsorption and endothermic. The obtained results provide an insight for potential applications of ACDS in the treatment of water contaminated by dyes.
A Lightweight AlTiVNb High-Entropy Alloy Film with High Strength-Ductility Synergy and Corrosion Resistance
Authors: Feng Xiaobin , Feng Chuangshi , Lu Yang
Published: December 2022

The simultaneous improvement of mechanical and corrosion resistance is of great significance for engineering applications. In this work, a novel lightweight amorphous structure AlTiVNb high-entropy alloy (HEA) film was fabricated by magnetron sputtering. The compression test of the AlTiVNb HEA film nanopillar exhibits a high compressive strength of up to 3.6 GPa and deformability approaching 58%. The high strength is affected by the disordered state, the nanostructure, and the lattice distortion effect, while the high ductility comes from the ductile shear band and the island structure. In addition, the AlTiVNb HEA film shows a current density of 4.90 × 10−8 A/cm2 and a potential of −0.234 V in the 3.5% NaCl solution, comparable to that of the 316L stainless steel. The chemical disorder state, cocktail effect, and homogeneous amorphous structure contribute to excellent corrosion resistance. This finding offers new insights into high-performance HEA films with robust mechanical and anticorrosion performances for microelectronic devices and mechanical metamaterials.
Patient-Specific Stent Fabrication Using a Seven-Degree-of-Freedom Additive Manufacturing System
Authors: Huss John M. , Lehman Malachi , Erdman Arthur G.
Published: December 2022

With advances in additive manufacturing technologies, the creation of medical devices which are tailored to the geometry of a patient’s unique anatomy is becoming more feasible. The following paper details the capabilities of a seven-degree-of-freedom fused filament deposition modeling system which enables a wide variety of user-control over previously restricted parameters, such as nozzle angle, print bed rotation, and print bed tilt. The unique capabilities of this system will be showcased through the production of a patient-specific tracheal stent using three different methods: segmented overmolding, transverse rastering, and longitudinal rastering. The resulting opportunities and time savings demonstrated by the prints will provide a case for greater implementation of seven-degree-of-freedom manufacturing technologies.
Towards a Fault Diagnosis Method for Rolling Bearings with Time-Frequency Region-Based Convolutional Neural Network
Authors: Tang Jiahui , Wu Jimei , Hu Bingbing , Qing Jiajuan
Published: December 2022

An artificial-intelligence (AI)-based method for fault diagnosis is a strong candidate for industrial applications in the health management of rolling bearings. However, traditional fault diagnosis methods fail to improve the detection accuracy because they only extract a single feature and have limitations in feature representation. In addition, advanced object detection frameworks such as region-based convolutional neural networks have not yet been applied in fault diagnosis. To this end, a fault diagnosis model using a Time-Frequency Region-Based Convolutional Neural Network (TF-RCNN) is proposed in this paper. This method was mainly adopted to extract multiple regions that can characterize fault features from the Time-Frequency Representation (TFR). Specifically, an attention module was introduced so the model could focus on representative features. The existing classification strategy was also enhanced to perform multiple types of fault classification. Finally, an end-to-end rolling bearing fault diagnosis framework based on the TF-RCNN was developed with the aforementioned improvements. The effectiveness of this method was proven experimentally on artificial faults and real faults. The superiority of the proposed method is demonstrated using a comparison with the typical object detection method and an advanced fault diagnosis method.
Configuration-Dependent Substructuring as a Tool to Predict the Vibrational Response of Mechanisms
Authors: Brunetti Jacopo , D’Ambrogio Walter , Fregolent Annalisa
Published: December 2022

Dynamic substructuring allows us to predict the dynamic behavior of mechanical systems built by linking together several subsystems, whose dynamic behavior is known. The classical formulation, originally conceived for invariant systems, was extended by the authors to include mechanical systems made by invariant subsystems that may be coupled in different configurations. A mechanism is a typical example of a mechanical system built by coupling together invariant subsystems; during its motion, it can take several configurations that significantly affect its vibrational behavior. Therefore, the configuration-dependent substructuring approach can provide meaningful insights into the dynamic behavior of the mechanism. In this paper, the proposed approach is exploited to evaluate the vibrational behavior of a three-point linkage, a widely used mechanism to connect agricultural tractors to operating machines, considering a significant range of operative configurations. The proposed substructuring approach is able to predict the frequency response functions, the natural frequencies and the mode shapes of the mechanism in a wide range of configurations.
Solitary Wave Interactions with an External Periodic Force: The Extended Korteweg-de Vries Framework
Authors: Flamarion Marcelo V. , Pelinovsky Efim
Published: December 2022

In this work we asymptotically and numerically studied the interaction of large amplitude solitary waves with an external periodic force using the forced extended Korteweg-de Vries equation (feKdV). Regarding these interactions, we found three types of regimes depending on the amplitude of the solitary wave and how its speed and the speed of the external force are related. A solitary wave can remain steady when its crest and the crest of the external force are in phase, it can bounce back and forth remaining close to its initial position when its speed and the external force speed are near resonant, or it can move away from its initial position without reversing its direction. Additionally, we verified that the numerical results agreed qualitatively well within the asymptotic approximation theory for external broad forces.
Marine Compounds and Cancer: Updates 2022
Authors: Dyshlovoy Sergey A. , Honecker Friedemann
Published: December 2022

The field of marine bioactive compounds (marine drugs) has evolved significantly in recent years [...]
Estonian Parents’ Awareness of Pediculosis and Its Occurrence in Their Children
Authors: Kutman Ave , Parm Ülle , Tamm Anna-Liisa , Hüneva Birgit , Jesin Diana
Published: December 2022

Background and Objectives: Pediculosis, or head lice infestation, is a widespread health problem that can affect anyone, regardless of gender, age, or social background. The purpose of this study was to clarify the occurrence of pediculosis among Estonian preschool- and primary school-aged children according to their parents and the parent’s awareness of pediculosis and related behaviors. Materials and Methods: An online questionnaire was completed by the parents of the preschool children (n = 1141) in 2019 and the parents of the elementary school children (n = 362) in 2021. For the descriptive data, t-test, Mann–Whitney or χ2 test, linear regression, and logistic regression analyses were applied. Results: According to the parents, pediculosis had occurred in 34.7% of the children, and more than one-third of pediculosis patients had experienced it more than twice. Lice were mainly acquired from elementary school or preschool and less often from friends, relatives, or training environments. Parents’ knowledge of head lice was rather good; the average score of the correct answers was 14.0 ± 3.4 (max. 20). In the multivariate analysis, higher age (coefficient 0.07, p < 0.001), healthcare education (coefficient 1.19, p < 0.001), and a previous occurrence of pediculosis in a family (coefficient 1.95; p < 0.001) were factors influencing better knowledge. In order to treat the infestation, antilice shampoo and combing were the most often used methods. Conclusion: Despite parents’ awareness, pediculosis infestations continue to be common among our children.
Combined Bentall and Modified Ravitch Procedures: A Case Report and Systematic Review of the Evidence
Authors: Taghizadeh Waghefi Ali , Petrov Asen , Wilbring Manuel , Fajfrova Zuzana , Fitze Guido , Matschke Klaus , Kappert Utz
Published: December 2022

Background and Objectives: Marfan syndrome (MS) is a genetic disorder with autosomal dominant inheritance that affects the connective tissue and consequently many organ systems. The cardiovascular manifestations of MS are notorious and include aortic root dilatation or acute aortic dissection, which can cause morbidity and early mortality. However, surgical treatment of aortic pathology may be complicated by musculoskeletal deformity of the chest wall, as in pectus excavatum. In this regard, single-stage combined Bentall and Ravitch surgery is an extreme rarity that has also been scarcely reported in the literature. Patients and Methods: We present the medical history and single-stage Bentall and modified Ravitch surgical treatment of an 18-year-old male MS patient with symptomatic and severe pectus excavatum (PEX) in conjunction with a pear-shaped aortic root aneurysm. To discuss our case in the context of a synopsis of similar published cases, we present a systematic review of combined Bentall surgical aortic aneurysm repair and Ravitch correction of PEX. Results: A total of four studies (one case series and three case reports) and a case from our institution describing a single-stage combined Bentall and Ravitch operation were included. Patients were 22 ± 5.9 years of age (median = 22.5 years) and predominantly male (60%). All cases reported a midline vertical skin incision over the sternum. The most common surgical approach was midsternotomy (80%). In all cases metal struts were used to reinforce the corrected chest wall. Postoperative mortality was zero. Conclusions: Single-stage combined Bentall and Ravitch surgery is an underutilized surgical approach. Its use in MS patients with concomitant PEX and ascending aortic aneurysm that require surgical treatment warrants further investigation. Midsternotomy seems to be a viable access route that provides sufficient exposure in the single-stage surgical setting. Although operative time is long, the intraoperative and postoperative risks appear to be low and manageable.
Effect of Direct Rolling Process on Microstructure and Mechanical Properties of the Electron Beam Cold Hearth Melting Ti-6Al-4V Alloy
Authors: Zhang Haoze , Yi Jianhong , Wang Junsheng , Xiao Han , Wang Meng , Wang Wei
Published: December 2022

Titanium alloy is a key supporting material in the field of engineering technology and high-tech, and also an extremely important national defense strategic metal material. However, the high cost limits its wider application. Direct rolling of titanium alloy melted by electron beam cold hearth melting (EBCHM) technology is considered to be an important low-cost plate production process. The rolling process has a considerable influence on the microstructure and mechanical properties of the alloy. Therefore, Ti-6Al-4V alloy melted by EBCHM technology was investigated in this study. The effects of different rolling processes on the microstructural evolution and mechanical properties of titanium alloy plates were evaluated. The results show that with the increase of deformation amount and rolling temperature, the more obvious the disintegration of lamella α and the higher the degree of equiaxation when the deformation is below the β transus. However, only dynamic recovery occurs when rolling temperature above the β transus, and lamella α does not undergo disintegration and equiaxation. With ultimate tensile strength (UTS) of 1076 MPa and elongation (EI) of 11%, the plate with 90% deformation at 950 °C has good strength and plasticity.
A Multifocal Study Investigation of Pyrolyzed Printed Circuit Board Leaching
Authors: Jovanović Gvozden , Bugarčić Mladen , Petronijević Nela , Stopic Srecko R. , Friedrich Bernd , Marković Branislav , Stanković Srđan , Sokić Miroslav
Published: December 2022

Electric waste from numerous devices that are put out of use every day has some form of printed circuit board that contains precious and valuable metals in their components. In order to extract these metals, the printed circuit boards were crushed and pyrolyzed into powder. The fine pyrolyzed printed circuit board (PPCB) powder was separated into fractions, and the fine metallic fraction was used as a raw material for metal leaching extraction. In order to better understand how various metal species react in leaching media, several leaching agents were used (sulfuric acid, nitric acid, glycine, and acid mine drainage-AMD) alone, and with the addition of hydrogen peroxide. Additionally, the influence of the S/L ratio and leaching temperature were investigated in sulfuric acid leaching solutions, as this is the one most widely used. In one case, the reactor was heated in a thermal bath, while in the other, it was heated in an ultrasonic bath. Lastly, several experiments were conducted with a (consecutive) two-pronged leaching approach, with and without applied pretreatment. The aim of this paper is to give a multifocal and detailed approach to how metals such as Al, Cu, Co, Zn, Sn, and Ca behave when extracted from fine PPCB powder. However, some attention is given to Nd, Pd, Pb, and Ba as well. One of the main findings is that regardless of the pretreatment or the sequence of leaching media applied, consecutive two-pronged leaching cannot be used for selective metal extraction. However, AMD was found to be suitable for selective leaching with very limited applications.
Kinetics and Mechanisms of Artificial Willemite Leaching in Low-Sulfuric-Acid Solution at Elevated Temperature
Authors: Xu Hongsheng , Qian Yanan , Zhou Quanfa , Wei Chang , Wang Qi , Zhao Wenjie , Zhu Binglong , Wu Juan , Ren Fang , Xu Jingxu
Published: December 2022

The present study was undertaken to investigate the effects of temperature, sulfuric acid concentration, agitation speed, and particle size on the high-temperature leaching kinetics of artificial willemite in low sulfuric acid solution. A mathematical model taking into account the change in acid concentration was evaluated for the leaching rate increased with increasing sulfuric acid concentration, temperature, and agitation speed and decreasing particle size. The kinetic analysis indicated that the leaching process was well interpreted by a modified grain model with product layer diffusion as the main rate-controlling step, and the shrinking core model was used to represent the reaction of each grain. The characteristic changes of the sample before and after leaching were studied using a scanning electron microscope/energy dispersive X-ray spectrometer (SEM/EDS) and X-ray diffraction (XRD) to elucidate the leaching mechanism. The apparent activation energy was found to be 22.06 kJ/mol at 373–413 K, and the reaction order with sulfuric acid concentration was 1.6472. On the basis of the grain model, the following rate equation was established: 1.07ln(1−0.93x)−[1.28ln0.17+(1−x)23−0.42(1−x)130.17+(1−x)23+0.84(1−x)13+4.5arctan(2.76(1−x)13−0.58)]+3.8=43.55e−22060RTt.
Impact of Copper, Tin and Titanium Addition on Bending-Induced Damage of Intermetallic Phases in Hot Dip Galvanizing
Authors: Bellini Costanzo , Di Cocco Vittorio , Iacoviello Francesco , Mocanu Larisa Patricia
Published: December 2022

Hot dip galvanizing is among the cheapest methods for protecting ferrous alloys against corrosion. The success is due to both the low cost of the process and the high degree of protection in many corrosive environments, where the coatings serve as sacrificial protection. The purpose of this analysis is to study the mechanical characteristics of steel plates, that have been hot dip coated with five different zinc alloy molten bath for different time periods. The mechanical tests performed is a non-standardized four-point bending test considering three distinct bending angles. Results are examined in terms of both mechanical behaviour and coating phase damage. The development of intermetallic phases and their damage are both influenced by the chemical compositions of the zinc bath, demonstrating that fractures arise mostly at the substrate-coating interface. All the coatings showed the arising of micro-cracks except for the Aluminium, which demonstrated its ductility. In addition, Zn-Ti coatings showed the arising of a new compact phase rich in iron, characterized by a great hardness. More research is needed to explore the aluminium impact on the zinc bath, the lack of tiny fractures in the phase, and the lesser thickness compared to the other coatings tested.
The Challenges of Modeling Defect Behavior and Plasticity across Spatial and Temporal Scales: A Case Study of Metal Bilayer Impact
Authors: Granger Leah , Chen Muh-Jang , Brenner Donald , Zikry Mohammed
Published: December 2022

Atomistic molecular dynamics (MD) and a microstructural dislocation density-based crystalline plasticity (DCP) framework were used together across time scales varying from picoseconds to nanoseconds and length scales spanning from angstroms to micrometers to model a buried copper–nickel interface subjected to high strain rates. The nucleation and evolution of defects, such as dislocations and stacking faults, as well as large inelastic strain accumulations and wave-induced stress reflections were physically represented in both approaches. Both methods showed similar qualitative behavior, such as defects originating along the impactor edges, a dominance of Shockley partial dislocations, and non-continuous dislocation distributions across the buried interface. The favorable comparison between methods justifies assumptions used in both, to model phenomena, such as the nucleation and interactions of single defects and partials with reflected tensile waves, based on MD predictions, which are consistent with the evolution of perfect and partial dislocation densities as predicted by DCP. This substantiates how the nanoscale as modeled by MD is representative of microstructural behavior as modeled by DCP.
Innovative Approach for the Evaluation of the Mechanical Behavior of Dissimilar Welded Joints
Authors: Carone Simone , Corigliano Pasqualino , Epasto Gabriella , Moramarco Vincenzo , Palomba Giulia , Pappalettera Giovanni , Casavola Caterina
Published: December 2022

This study aims to propose a thorough experimental methodology to assess the mechanical quality of dissimilar joints. This comprehensive approach investigates the fatigue behavior by exploiting the thermographic method, accompanying and correlating the results with information obtained from extensive measurements of residual stresses and detailed evaluation of fracture surfaces. The integration of the information obtained by this hybrid approach allows for a deeper understanding in terms of fatigue behavior even in complicated situations as those represented by dissimilar welded joints. A complex laser-welded Ti6Al4V/Inconel 625 dissimilar joint, obtained using intermediate inserts of Vanadium and AISI 304, was considered as case study. The residual stresses, both longitudinal and transverse to the weld beads, were measured on surface by means of X-ray diffraction, whereas, for in-depth measurements, the multiple-cut contour method was implemented to determine full 2D maps of longitudinal residual stresses with the first cut, and transverse stresses in the Vanadium insert with the second cut. In the investigation of longitudinal residual stresses, the area mostly affected by harmful tensile residual stresses is the weld between the stainless steel and Vanadium, where the maximum value of about 560 MPa is reached; the analysis of transverse residual stresses highlighted a maximum value of 350 MPa at the core of the Vanadium insert. The fatigue behavior of the joints was investigated along with a detailed analysis of the fractured surfaces by scanning electron and confocal microscopes. The analysis of the fracture surfaces indicated that the failure modes are mainly related to the occurrence of defects on the crack path, especially at stress range higher than 200 MPa, for which a large number of pores cluster were detected. Nevertheless, the crack initiation is usually on the side of Vanadium. When the crack path deviates on the stainless-steel region, the fracture mode is brittle due to high residual stresses.
Dynamic Analysis and Path Planning of a Turtle-Inspired Amphibious Spherical Robot
Authors: Zheng Liang , Tang You , Guo Shuxiang , Ma Yuke , Deng Lijin
Published: December 2022

A dynamic path-planning algorithm based on a general constrained optimization problem (GCOP) model and a sequential quadratic programming (SQP) method with sensor input is proposed in this paper. In an unknown underwater space, the turtle-inspired amphibious spherical robot (ASR) can realise the path-planning control movement and achieve collision avoidance. Due to the special underwater environments, thrusters and diamond parallel legs (DPLs) are installed in the lower hemisphere to realise accurate motion control. A propulsion model for a novel water-jet thruster based on experimental analysis and a modified Denavit–Hartenberg (MDH) algorithm are developed for multiple degrees of freedom (MDOF) to realize high-precision and high-speed motion control. Simulations and experiments verify that the effectiveness of the GCOP and SQP algorithms can realize reasonable path planning and make it possible to improve the flexibility of underwater movement with a small estimation error.
Tellurium-Modified Nucleosides, Nucleotides, and Nucleic Acids with Potential Applications
Authors: Chen Cen , Huang Zhen
Published: December 2022

Tellurium was successfully incorporated into proteins and applied to protein structure determination through X-ray crystallography. However, studies on tellurium modification of DNA and RNA are limited. This review highlights the recent development of Te-modified nucleosides, nucleotides, and nucleic acids, and summarizes the main synthetic approaches for the preparation of 5-PhTe, 2′-MeTe, and 2′-PhTe modifications. Those modifications are compatible with solid-phase synthesis and stable during Te-oligonucleotide purification. Moreover, the ideal electronic and atomic properties of tellurium for generating clear isomorphous signals give Te-modified DNA and RNA great potential applications in 3D crystal structure determination through X-ray diffraction. STM study also shows that Te-modified DNA has strong topographic and current peaks, which immediately suggests potential applications in nucleic acid direct imaging, nanomaterials, molecular electronics, and diagnostics. Theoretical studies indicate the potential application of Te-modified nucleosides in cancer therapy.