bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Novel NGS Methodology for Ultrasensitive Circulating Tumor DNA Detection as a Tool for Early-Stage Breast Cancer Diagnosis
Authors: Jiménez-Rodríguez Begoña , Alba-Bernal Alfonso , López-López Esperanza , Quirós-Ortega María Elena , Carbajosa Guillermo , Garrido-Aranda Alicia , Álvarez Martina , Godoy-Ortiz Ana , Queipo-Ortuño María Isabel , Vicioso Luis , Díaz-Córdoba Gema , Roldán-Díaz María Dunia , Velasco-Suelto Jesús , Hernando Cristina , Bermejo Begoña , Julve-Parreño Ana , Lluch Ana , Pascual Javier , Comino-Méndez Iñaki , Alba Emilio
Published: December 2022

Breast cancer (BC) is the most prevalent cancer in women. While usually detected when localized, invasive procedures are still required for diagnosis. Herein, we developed a novel ultrasensitive pipeline to detect circulating tumor DNA (ctDNA) in a series of 75 plasma samples from localized BC patients prior to any medical intervention. We first performed a tumor-informed analysis to correlate the mutations found in tumor tissue and plasma. Disregarding the tumor data next, we developed an approach to detect tumor mutations in plasma. We observed a mutation concordance between the tumor and plasma of 29.50% with a sensitivity down to 0.03% in mutant variant allele frequency (VAF). We detected mutations in 33.78% of the samples, identifying eight patients with plasma-only mutations. Altogether, we determined a specificity of 86.36% and a positive predictive value of 88.46% for BC detection. We demonstrated an association between higher ctDNA median VAF and higher tumor grade, multiple plasma mutations with a likelihood of relapse and more frequent TP53 plasma mutations in hormone receptor-negative tumors. Overall, we have developed a unique ultra-sensitive sequencing workflow with a technology not previously employed in early BC, paving the way for its application in BC screening.
Exposure of Immunogenic Tumor Antigens in Surrendered Immunity and the Significance of Autologous Tumor Cell-Based Vaccination in Precision Medicine
Authors: Ke Chiao-Hsu , Chiu Yi-Han , Huang Kuo-Chin , Lin Chen-Si
Published: December 2022

The mechanisms by which immune systems identify and destroy tumors, known as immunosurveillance, have been discussed for decades. However, several factors that lead to tumor persistence and escape from the attack of immune cells in a normal immune system have been found. In the process known as immunoediting, tumors decrease their immunogenicity and evade immunosurveillance. Furthermore, tumors exploit factors such as regulatory T cells, myeloid-derived suppressive cells, and inhibitory cytokines that avoid cytotoxic T cell (CTL) recognition. Current immunotherapies targeting tumors and their surroundings have been proposed. One such immunotherapy is autologous cancer vaccines (ACVs), which are characterized by enriched tumor antigens that can escalate specific CTL responses. Unfortunately, ACVs usually fail to activate desirable therapeutic effects, and the low immunogenicity of ACVs still needs to be elucidated. This difficulty highlights the significance of immunogenic antigens in antitumor therapies. Previous studies have shown that defective host immunity triggers tumor development by reprogramming tumor antigenic expressions. This phenomenon sheds new light on ACVs and provides a potential cue to improve the effectiveness of ACVs. Furthermore, synergistically with the ACV treatment, combinational therapy, which can reverse the suppressive tumor microenvironments, has also been widely proposed. Thus, in this review, we focus on tumor immunogenicity sculpted by the immune systems and discuss the significance and application of restructuring tumor antigens in precision medicine.
4-Hexylresorcinol Treatment before Degumming Increases the β-Sheet Structure of Silk Sericin and BMP-2 Expression in RAW264.7 Cells
Authors: Lee Ji Hae , Kweon HaeYong , Oh Ji-Hyeon , Kang Yei-Jin , Kim Dae-Won , Yang Won-Geun , Chae Weon-Sik , Kim Seong-Gon
Published: December 2022

Silk sericin is a degumming product used by the silk industry. The degumming process can affect the protein structure and molecular weight of silk sericin. The present study examined how pretreatment with 4-hexylresorcinol (4HR) affects the biomedical properties of silk sericin. Before the degumming process, silkworm cocoons were treated with 4HR solution. The protein structure of the final degumming product was evaluated by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy. Untreated silk sericin (S) and silk sericin pretreated with 4HR (S+4HR) were added to RAW264.7 cells, and the expression of BMP-2 was determined. The bone-regenerating capacity of S+4HR was evaluated using the critical-sized rat calvarial defect model. Compared with S, S+4HR showed an increase in β-sheet structures. Administration of S+4HR to RAW264.7 cells increased expression of BMP-2, mainly via the TLR-mediated signaling pathway. Bone volume, as measured by micro-computerized tomography, was significantly greater in the S+4HR group than in the S, gelatin alone, and unfilled control groups (p < 0.05 each). Expression of BMP-2 and runx2 in tissue specimens was significantly higher following treatment with S+4HR than with S (p < 0.05). Taken together, these findings show that 4HR pretreatment before the degumming process increased the β-sheet structure of silk sericin, as well as inducing BMP-2 expression and bone regeneration ability.
The D165H Polymorphism of QiMYB-like-1 Is Linked to Interactions between Tannin Accumulation, Herbivory and Biogeographical Determinants of Quercus ilex
Authors: Gallardo Alejandro , Morcuende David , Rodríguez-Romero Manuela , Igeño María Isabel , Pulido Fernando , Quesada Alberto
Published: December 2022

The accumulation in the leaves and young stems of phenolic compounds, such as hydrolyzable and condensed tannins, constitutes a defense mechanism of plants against herbivores. Among other stressing factors, chronic herbivory endangers Quercus ilex, a tree playing a central role in Mediterranean forests. This work addressed the connections between the chemical defenses of Q. ilex leaves and their susceptibility to herbivory, quantitative traits whose relationships are modulated by environmental and genetic factors that could be useful as molecular markers for the selection of plants with improved fitness. A search for natural variants detected the polymorphism D165H in the effector domain of QiMYB-like-1, a TT2-like transcription factor whose family includes members that control the late steps of condensed tannins biosynthesis in different plant species. QiMYB-like-1 D165H polymorphism was screened by PCR-RFLP in trees from six national parks in Spain where Q. ilex has a relevant presence, revealing that, unlike most regions that match the Hardy-Weinberg equilibrium, homozygous plants are over-represented in “Monfragüe” and “Cabañeros”, among the best examples to represent the continental Mediterranean (cM) ecosystem. Accordingly, the averages of two stress-related quantitative traits measured in leaves, herbivory index and accumulation of condensed tannins, showed asymmetric distributions depending on the clustering of trees based on ecological and genetic factors. Thus, the impact of herbivory was greater in managed forests with a low density of trees from the cM region, among which QiMYB-like-1 D165 homozygotes stand out, whereas condensed tannins accumulation was higher in leaves of QiMYB-like-1 H165 homozygotes from low-density forests, mainly in the Pyrenean (Py) region. Besides, the correlation between the contents of condensed tannins and total tannins vanished after clustering by the same factors: the cM region singularity, forest tree density, and QiMYB-like-1 genotype, among which homozygous shared the lowest link. The biogeographical and genetic constraints that modulate the contribution of condensed tannins to chemical defenses also mediated their interactions with the herbivory index, which was found positively correlated with total phenolics or tannins, suggesting an induction signal by this biotic stress. In contrast, a negative correlation was observed with condensed tannins after tree clustering by genetics factors where associations between tannins were lost. Therefore, condensed tannins might protect Q. ilex from defoliation in parks belonging to the cM ecosystem and carrying genetic factor(s) linked to the QiMYB-like-1 D165H polymorphism.
Presence of Ceramidase Activity in Electronegative LDL
Authors: Puig Núria , Rives Jose , Estruch Montserrat , Aguilera-Simon Ana , Rotllan Noemi , Camacho Mercedes , Colomé Núria , Canals Francesc , Sánchez-Quesada José Luis , Benitez Sonia
Published: December 2022

Electronegative low-density lipoprotein (LDL(−)) is a minor modified fraction of human plasma LDL with several atherogenic properties. Among them is increased bioactive lipid mediator content, such as lysophosphatidylcholine (LPC), non-esterified fatty acids (NEFA), ceramide (Cer), and sphingosine (Sph), which are related to the presence of some phospholipolytic activities, including platelet-activating factor acetylhydrolase (PAF-AH), phospholipase C (PLC), and sphingomyelinase (SMase), in LDL(−). However, these enzymes’ activities do not explain the increased Sph content, which typically derives from Cer degradation. In the present study, we analyzed the putative presence of ceramidase (CDase) activity, which could explain the increased Sph content. Thin layer chromatography (TLC) and lipidomic analysis showed that Cer, Sph, and NEFA spontaneously increased in LDL(−) incubated alone at 37 °C, in contrast with native LDL(+). An inhibitor of neutral CDase prevented the formation of Sph and, in turn, increased Cer content in LDL(−). In addition, LDL(−) efficiently degraded fluorescently labeled Cer (NBD-Cer) to form Sph and NEFA. These observations defend the existence of the CDase-like activity’s association with LDL(−). However, neither the proteomic analysis nor the Western blot detected the presence of an enzyme with known CDase activity. Further studies are thus warranted to define the origin of the CDase-like activity detected in LDL(−).
Heat Transfer Investigation during Condensation on the Horizontal Pipe
Authors: Zainullina Elza R. , Mityakov Vladimir Yu.
Published: December 2022

This paper presents an experimental investigation of condensation heat transfer by gradient heatmetry. The experiments were carried out during the condensation of saturated steam at atmospheric pressure on the cooled surface of a horizontal pipe. The distributions of the local heat flux, surface temperature, and heat transfer coefficient along the circumference of the horizontal pipe were experimentally determined. The surface average condensation heat flux on the horizontal pipe was about 141.06 kW/m2. The proposed method allows us to determine the area of condensate accumulation on the pipe (in the range of azimuth angle φ = 150…180∘) in which the heat flux decreases by 34% of the average value. The heat flux per unit area relative uncertainty was about 5.2%. The surface-averaged heat transfer coefficient during condensation on the horizontal pipe was about 5.5 kW/(m2×K), and relative uncertainty was about 9.4%.
Survival and Functional Outcomes after Surgical Treatment for Spinal Metastasis in Patients with a Short Life Expectancy
Authors: Park Se-Jun , Ma Chang-Hyun , Lee Chong-Suh , Jeon Chung-Youb , Shin Tae-Soo , Park Jin-Sung
Published: December 2022

This study aimed to analyze the survival and functional outcome after surgery in spinal metastasis patients with a short life expectancy and to compare the baseline characteristics based on 3-month survival. A total of 492 surgical treatment cases with a preoperative revised Tokuhashi score ≤ 8were reviewed. Median survival was calculated and Kaplan–Meier analysis was used to analyze the survival rates at 6 months, 1 year, and 2 years postoperatively. The surgical period was divided into three time frames to examine the time trends. For the functional outcome, Eastern Cooperative Oncology Group Performance Status (ECOG-PS) was analyzed. This study categorized subjects based on 3-month survival and compared the baseline characteristics. The median overall survival was 10.6 months. The 2013–2020 period showed a significantly better median survival than the other two periods (p < 0.001). Lung and kidney cancers showed a significant survival improvement in 2013–2020 (p < 0.001). Patients with ECOG-PS ≤ 2 increased from 37.4% preoperatively to 63.7% postoperatively (p < 0.001). There were significantly more cases of preoperative favorable performance status, slow and moderate growth cancers, and chemotherapy after surgery in the survival ≥3 months group. Depending on the type of primary cancer, surgery can be considered even in spinal metastasis patients with a short life expectancy, particularly those with a good performance status.
A Mad7 System for Genetic Engineering of Filamentous Fungi
Authors: Vanegas Katherina Garcia , Rendsvig Jakob Kræmmer Haar , Jarczynska Zofia Dorota , Cortes Marcio Vinicius de Carvalho Barros , van Esch Abel Peter , Morera-Gómez Martí , Contesini Fabiano Jares , Mortensen Uffe Hasbro
Published: December 2022

The introduction of CRISPR technologies has revolutionized strain engineering in filamentous fungi. However, its use in commercial applications has been hampered by concerns over intellectual property (IP) ownership, and there is a need for implementing Cas nucleases that are not limited by complex IP constraints. One promising candidate in this context is the Mad7 enzyme, and we here present a versatile Mad7-CRISPR vector-set that can be efficiently used for the genetic engineering of four different Aspergillus species: Aspergillus nidulans, A. niger, A. oryzae and A. campestris, the latter being a species that has never previously been genetically engineered. We successfully used Mad7 to introduce unspecific as well as specific template-directed mutations including gene disruptions, gene insertions and gene deletions. Moreover, we demonstrate that both single-stranded oligonucleotides and PCR fragments equipped with short and long targeting sequences can be used for efficient marker-free gene editing. Importantly, our CRISPR/Mad7 system was functional in both non-homologous end-joining (NHEJ) proficient and deficient strains. Therefore, the newly implemented CRISPR/Mad7 was efficient to promote gene deletions and integrations using different types of DNA repair in four different Aspergillus species, resulting in the expansion of CRISPR toolboxes in fungal cell factories.
Evaluation of Cerebral Volume Changes in Patients with Tremor Treated by MRgFUS Thalamotomy
Authors: Bruno Federico , Tommasino Emanuele , Catalucci Alessia , Pastorelli Cristina , Borea Francesco , Caldarelli Giulia , Bellini Mattia , Badini Pierfrancesco , Mancini Sara , Santobuono Chiara , Martino Saverio , Pagliei Valeria , Manco Guglielmo , Cerone Davide , Pistoia Francesca , Palumbo Pierpaolo , Arrigoni Francesco , Di Cesare Ernesto , Marini Carmine , Barile Antonio , Splendiani Alessandra , Masciocchi Carlo
Published: December 2022

The purpose of the study is to quantify volumetric variations of cortical and subcortical brain structures after Vim ablation using MRgFUS, and correlate them with the patients’ clinical features and treatment outcomes. For this pilot retrospective study we enrolled 31 patients with a mean age of 70.86 years who were eligible for unilateral Vim thalamotomy. Clinical evaluation included tremor severity assessment using the FTM scale and cognitive assessment using the MoCA score. MRI data were acquired with a 3T scanner, using a dedicated 32-channel coil and acquiring a volumetric sequence of T1 3D IR FSPGR (BRAVO), before treatment and one year after MRgFUS thalamotomy. Image processing and volume data extraction were conducted with dedicated software. A volumetric analysis showed a significant reduction (p < 0.05) of the left thalamus 1 year after the treatment in patients with ET. Other significant results were found on the same side in the other nuclei of the basal ganglia and in the cerebellar cortex. In confronting the two groups (ET, PD), no significant differences were found in terms of age, FTM, MoCA scores, or brain volumes. Similarly, no significant correlations were found between the FTM and MoCA scores and the brain volumes before the treatment.
RNA Foci Formation in a Retinal Glial Model for Spinocerebellar Ataxia Type 7
Authors: Suárez-Sánchez Rocío , Ávila-Avilés Rodolfo Daniel , Hernández-Hernández J. Manuel , Sánchez-Celis Daniel , Azotla-Vilchis Cuauhtli N. , Gómez-Macías Enue R. , Leyva-García Norberto , Ortega Arturo , Magaña Jonathan J. , Cisneros Bulmaro , Hernández-Hernández Oscar
Published: December 2022

Spinocerebellar ataxia type 7 (SCA7) is a neurodegenerative disorder characterized by cerebellar ataxia and retinopathy. SCA7 is caused by a CAG expansion in the ATXN7 gene, which results in an extended polyglutamine (polyQ) tract in the encoded protein, the ataxin-7. PolyQ expanded ataxin-7 elicits neurodegeneration in cerebellar Purkinje cells, however, its impact on the SCA7-associated retinopathy remains to be addressed. Since Müller glial cells play an essential role in retinal homeostasis, we generate an inducible model for SCA7, based on the glial Müller MIO-M1 cell line. The SCA7 pathogenesis has been explained by a protein gain-of-function mechanism, however, the contribution of the mutant RNA to the disease cannot be excluded. In this direction, we found nuclear and cytoplasmic foci containing mutant RNA accompanied by subtle alternative splicing defects in MIO-M1 cells. RNA foci were also observed in cells from different lineages, including peripheral mononuclear leukocytes derived from SCA7 patient, suggesting that this molecular mark could be used as a blood biomarker for SCA7. Collectively, our data showed that our glial cell model exhibits the molecular features of SCA7, which makes it a suitable model to study the RNA toxicity mechanisms, as well as to explore therapeutic strategies aiming to alleviate glial dysfunction.
Influence of Cold Atmospheric Plasma on Surface Characteristics and Bond Strength of a Resin Nanoceramic
Authors: Zhu Xiaoming , Shi Jiamin , Ye Xinyi , Ma Xinrong , Zheng Miao , Yang Yang , Tan Jianguo
Published: December 2022

The purpose of this study was to investigate the effect of cold atmospheric plasma (CAP) treatment on resin nanoceramic (RNC) surface state and its bond strength with resin cement. RNC with different surface treatments were prepared: control, sandblasting treatment (SB), hydrofluoric acid etching (HF) and plasma treatment of helium gas (CAP-He) and argon gas (CAP-Ar). The prepared samples were measured by SEM, Ra, Rz, contact angle goniometer, and XPS for surface characteristics. The shear bond test of RNC was examined in nine groups: SB + saline coupling agent (SL), HF + SL, CAP-He/Ar, CAP-He/Ar + SL, SB + CAP-He/Ar + SL, and control. The bond strength between RNC and resin cement was compared using shear bond strength test, before and after thermocycling. After CAP irradiation, the surface topography maintained, while the surface water contact angle was significantly reduced to 10.18° ± 1.36° (CAP-He) and 7.58° ± 1.79° (CAP-Ar). The removal of carbon contamination and inducing of oxygen radicals was detected after CAP treatment. The bond strength was improved by CAP treatment, but varied on CAP gas species and combination methods. CAP of Ar gas had better SBS than He gas. After thermocycling, CAP-Ar + SL showed the maximized shear bond strength (32.38 ± 1.42 MPa), even higher than SB + SL group (30.08 ± 2.80 MPa, p < 0.05). In conclusion, CAP treatment of helium and argon can improve the bonding properties of RNC by improving surface wettability, and CAP of argon gas combined with silane coupling agent shows the highest bond strength.
Structure Optimization of a Fe–Mn–Pd Alloy by Equal-Channel Angular Pressing for Biomedical Use
Authors: Rybalchenko Olga , Anisimova Natalia , Martynenko Natalia , Rybalchenko Georgy , Kiselevskiy Mikhail , Tabachkova Natalia , Shchetinin Igor , Raab Arseniy , Dobatkin Sergey
Published: December 2022

In this work, a Fe–Mn–Pd alloy was produced by methods of equal channel angular pressing (ECAP) in order to obtain an alloy with a high rate of degradation for the development of biodegradable devices. Special efforts were made to the obtaining of an ultrafine-grained structure of alloys in a fully austenitic state at temperatures of 300 °C and 450 °C. Further investigation of its effect on the corrosion rate and mechanical properties was carried out. The formation of an austenitic structure with structural element sizes of 100–250 nm after deformation was confirmed by X-ray diffraction analysis. ECAP proved to be the reason for a significant increase in strength with maximum σUTS = 1669 MPa and σYS = 1577 MPa while maintaining satisfactory plasticity. The alloy degradation rate was investigated using the potentiodynamic polarization analysis. The corrosion rate of the alloy after ECAP (~1 mm/y) is higher than that of the coarse-grained state and significantly higher than that of annealed iron (~0.2 mm/y). ECAP in both modes did not impair the biocompatibility of the Fe–Mn–Pd alloy and the colonization of the sample surface by cells.
Green Pervious Concrete Containing Diatomaceous Earth as Supplementary Cementitous Materials for Pavement Applications
Authors: Alex Alexander Gladwin , Jose Prakash Arul , Saberian Mohammad , Li Jie
Published: December 2022

Portland cement porous concrete (PCPC) has received immense interest recently due to its environmental aids. Its porous structure helps to reduce the water runoff amount while improving the recharge of groundwater. Earlier studies have concentrated on illustrating and knowing the functional as well as structural properties of PCPC. However, very few studies are available on PCPC in combination with natural silica sources as supplementary cementitious materials (SCMs). Most SCMs are by-products of industrial manufacturing processes and cause some environmental concerns, but with their pozzolanic effect, they could be utilized as partial substitute materials for ordinary Portland cement (OPC) to enhance the strength as well as durability performance. The aim of this study is to evaluate the effects of diatomaceous earth (DE) as a supplementary cementitious material for partial substitution of OPC for Portland cement porous concrete application. Compression strength, split tensile strength, and flexural strength tests were performed to determine the effect of partial replacement. To investigate the impact of test variables, basic tests, including void content and water permeability, were also performed. Compared to the control concrete, the results show that a 15% replacement of cement with DE significantly increased the compressive strength (by 53%) while also providing adequate porosity and better water permeability. Statistical analysis (ANOVA) and regression analysis showed that there is a significant (p < 0.05) growth within the physical characteristics of concrete upon the replacement of cement by 15% DE. Collectively, the replacement of cement with DE could not only improve the concrete strength but also reduce the consumption of cement, thereby lessening the cost of construction as well as indirectly reducing the carbon footprint.
Formation Mechanism of Thicker Intermetallic Compounds in Friction Stir Weld Joints of Dissimilar AA2024/AZ31B Alloys
Authors: Tan Maoju , Wu ChuanSong , Shi Lei
Published: December 2022

The hybrid structures of AA2024 aluminum alloy and AZ31B magnesium alloy have the advantages of being lightweight, having high specific strength, etc., which are of great application potentials in the aerospace industry. It is a key problem to realize the high-quality welding of these two dissimilar alloys. In this study, the friction stir welding (FSW) tests of AA2024 aluminum alloy and AZ31B magnesium alloy plates of thickness 3 mm were carried out. The intermetallic compounds (IMCs) at the bonding interface were characterized by scanning electron microscope, electron probe, and transmission electron microscope. It was found that the IMCs at the bonding interface in weld nugget zones of dissimilar AA2024/AZ31B FSW has a double-layer structure and a much larger thickness. During the welding process of AA2024/AZ31B, when the boundary of magnesium grains bulges and nucleates, the aluminum atoms diffuse into the magnesium grains, and the γ phase (Al12Mg17) nucleates at the bonding interface. The β phase (Al3Mg2) then precipitates at the grain boundary of the γ phase and preferentially grows into γ phase grains. The continuous grain growth to the aluminum side makes the copper contained in AA2024 aluminum alloy concentrate on the side of β phase, which reduces the nucleation work of recrystallization and phase transformation, and further promotes the nucleation and growth of IMCs grains. This is the main reason for the thicker IMCs in the FSW weld of dissimilar AA2024/AZ31B alloys.
Functionalized β-Cyclodextrins Catalyzed Environment-Friendly Cycloaddition of Carbon Dioxide and Epoxides
Authors: Wen Qin , Yuan Xuexin , Zhou Qiqi , Yang Hai-Jian , Jiang Qingqing , Hu Juncheng , Guo Cun-Yue
Published: December 2022

Ammonium, imidazole, or pyridinium functionalized β-cyclodextrins (β-CDs) were used as efficient one-component bifunctional catalysts for the coupling reaction of carbon dioxide (CO2) and epoxide without the addition of solvent and metal. The influence of different catalysts and reaction parameters on the catalytic performance were examined in detail. Under optimal conditions, Im-CD1-I catalysts functionalized with imidazole groups were able to convert various epoxides into target products with high selectivity and good conversion rates. The one-component bifunctional catalysts can also be recovered easily by filtration and reused at least for five times with only slight decrease in catalytic performance. Finally, a possible process for hydroxyl group-assisted ring-opening of epoxide and functionalized group- induced activation of CO2 was presented.
Effects of Micro-Arc Oxidation Discharge Parameters on Formation and Biomedical Properties of Hydroxyapatite-Containing Flower-like Structure Coatings
Authors: Chen Kuan-Ting , Huang Jun-Wei , Lin Wei-Ting , Kuo Tsung-Yuan , Chien Chi-Sheng , Chang Ching-Ping , Lin Yung-Ding
Published: December 2022

The micro-arc oxidation (MAO) process was used to prepare hydroxyapatite-containing flower-like structure coatings on commercially pure titanium substrates with various values of the applied voltage (330, 390, 450 V), applied current (0.4, 0.5, 0.6 A), and duration time (1, 3, 5 min). It was found that the surface morphology of the coatings was determined primarily by the applied voltage. A voltage of 330 V yielded a flower-like/plate-like structure, while voltages of 390 V and 450 V produced a flower-like structure and a porous morphology, respectively. The applied current and duration time mainly affected the coating formation speed and petal size of the flower-like structures, respectively. The coatings prepared using voltages of 330 V and 390 V (0.6 A, 5 min) both contained Ti, TiO2-A (anatase), TiO2-R (rutile), DCPD (CaHPO4·2H2O, calcium hydrogen phosphate), and hydroxyapatite (HA). However, the latter coating contained less DCPD and had a higher HA/DCPD ratio and a Ca/P ratio closer to the ideal value of HA. The coating prepared with a voltage of 450 V consisted mainly of Ti, TiO2-A, TiO2-R, and CaTiO3. For the coatings prepared with a voltage of 390 V, the flower-like structures consisted mainly of HA-containing compounds. DCPD plate-like structures were observed either between the HA-containing flower-like structures (330 V samples) or within the flower-like structures themselves (390 V samples). The coating surfaces with flower-like/plate-like or flower-like structures had a greater roughness, which increased their hydrophilicity and resulted in superior bioactivity (SBF immersion) and biocompatibility (MG-63 cell culture). The optimal biomedical performance was found in the 390 V coating due to its flower-like structure and high HA/DCPD ratio.
Preparation and Electrochromic Properties of Benzodithiophene-Isoindigo Conjugated Polymers with Oligoethylene Glycol Side Chains
Authors: Wang Qilin , Zhai Yuehui , Chao Danming , Chen Zheng , Jiang Zhenhua
Published: December 2022

Functional polymers featuring good processability in non-halogenated, benzene-free green solvents are highly desired due to health and environmental concerns. Herein, a series of novel D-A type conjugated polymers, PBDT-IIDs, are designed and successfully prepared by “green” functionalization of the polymers with highly hydrophilic, highly polar, highly flexible, and biocompatible oligoethylene glycol (OEG) side chains in order to improve the processability. These series polymers are named PBDT-IID2, PBDT-IID3, and PBDT-IID4, respectively, according to the number of oxygen atoms in the side chain. After confirmation by structural characterization, the basic properties of PBDT-IIDs are also investigated. With the increase in the OEG side chain length, the polymer PBDT-IID4 not only has good solubility in the halogen solvent chlorobenzene, but also exhibits excellent solubility in the green halogen-free solvent methyltetrahydrofuran (Me-THF). As a result, the green solvent Me-THF can also be applied to prepare PBDT-IIDs’ electrochromic active layers, except for chlorobenzene and toluene. The electrochromism of PBDT IIDs under both positive and negative voltages has a practical application potential. The several controllable switches between dark green and khaki (0–0.6 V) are expected to show great potential in the field of military camouflage. Furthermore, according to the principle of red, green, and blue (RGB) mixing, light blue-green in the reduced state (−1.6 V) can be used in the preparation of complementary ECDs to provide one of the three primary colors (green).
Fatigue Behavior of Additively Manufactured Stainless Steel 316L
Authors: Avanzini Andrea
Published: December 2022

316L stainless steel is the material of choice for several critical applications in which a combination of mechanical strength and resistance to corrosion is required, as in the biomedical field. Additive Manufacturing (AM) technologies can pave the way to new design solutions, but microstructure, defect types, and surface characteristics are substantially different in comparison to traditional processing routes, making the assessment of the long-term durability of AM materials and components a crucial aspect. In this paper a thorough review is presented of the relatively large body of recent literature devoted to investigations on fatigue of AM 316L, focusing on the comparison between different AM technologies and conventional processes and on the influence of processing and post-processing aspects in terms of fatigue strength and lifetime. Overall fatigue data are quite scattered, but the dependency of fatigue performances on surface finish, building orientation, and type of heat treatment can be clearly appreciated, as well as the influence of different printing processes. A critical discussion on the different testing approaches presented in the literature is also provided, highlighting the need for shared experimental test protocols and data presentation in order to better understand the complex correlations between fatigue behavior and processing parameters.
Functionalization of the Surface of Porous Nickel–Titanium Alloy with Macrocyclic Compounds
Authors: Marchenko Ekaterina , Luchsheva Venera , Baigonakova Gulsharat , Bakibaev Abdigali , Vorozhtsov Alexander
Published: December 2022

For the first time, we performed functionalization of the surface of porous titanium nickelide alloys with bambusuril[6]-based macrocyclic compounds by different methods in order to provide the basis for saturation with therapeutic agents to impart antibacterial activity and accelerate its osteogenesis. It has been shown for the first time that the vacuum modification method is preferable for bambusuril deposition, since it provides a uniform deposition of organic matter on both the outer and inner surfaces of the pores. The effect of bambusuril deposition methods on the continuity, structure, and cytocompatibility of the porous titanium nickelide surface was evaluated. In vitro tests proved high biocompatibility and low toxicity of porous TiNi treated with BU[6] under vacuum. The SEM study of the structure of the surface layer of TiNi modified with BU[6] under the vacuum method showed that BU[6] agglomerates are uniformly deposited on the inner and outer surfaces of TiNi pores, which will provide an even saturation of BU[6] cavities with various pharmaceuticals, including antibiotics and inhibitors.
Adducts of the Zinc Salt of Dinitramic Acid
Authors: Il’yasov Sergey G. , Glukhacheva Vera S. , Il’yasov Dmitri S. , Zhukov Egor E. , Eltsov Ilia V. , Nefedov Andrey A. , Gatilov Yuri V.
Published: December 2022

Herein, we describe the synthesis of coordination compounds starting from carbohydrazide ((H2NHN)2C=O (CHZ)) and the Zn2+ salt of dinitramic acid (HDN), which are high-nitrogen substances that exhibit properties similar to those of a burning-rate inhibitor of pyrotechnic compositions. This study demonstrates that these compounds react with glyoxal to furnish adducts of metal–organic macrocyclic cages bearing the elements of carbohydrazide, complexing metals and the HDN anion, depending on the ratio of the starting reactants. The assembled macrocyclic cage has “host–guest” properties and is a safe container for the storage of HDN salts. X-ray crystallographic analysis of the resultant coordination compound, [Zn(chz)3(N(NO2)2)2]), indicated that the metal–ligand association occurs via the N and O atoms of carbohydrazide. The zinc salt of dinitramic acid, which is enclosed into adducts with a macrocycle, is thermally stable and insensitive to mechanical impacts. The complex zinc salt of dinitramide was shown herein to exhibit inhibitory activity towards the burning rate of pyrotechnic compositions.
Influence of Weather Conditions and Mechanical Reclamation on Molding Sand with Alkali-Phenolic Binder for Manganese Cast Steel
Authors: Łucarz Mariusz , Drożyński Dariusz , Garbacz-Klempka Aldona , Jezierski Jan , Bartocha Dariusz , Wróbel Tomasz , Kostrzewa Krzysztof , Feliks Edward
Published: December 2022

The article presents the results of research on the properties of molding sands in Alphaset technology (alkaline-phenolic). These sands are often used in steel foundries, producing large castings. However, knowledge about them, and especially about the changeability of their properties with the change of environmental conditions (seasons), is still insufficient. Various compositions of molding sand were analyzed based on fresh chromite sand and reclaimed sand. A binder and hardener in various mass ratios were used to prepare the mass. The research methodology included, among others, tests of tensile and bending strength, permeability, abrasion, gas emissivity, and ignition losses. These tests were carried out for summer and winter conditions. The results showed the optimal proportions of resin and hardener, showed the influence of ambient temperature on the properties of the molding sand, and the possible ratio of reclaimed sand in relation to fresh sand. However, you should always remember to verify them under the conditions of a specific foundry.
Manufacturing of Pure Copper with Electron Beam Melting and the Effect of Thermal and Abrasive Post-Processing on Microstructure and Electric Conductivity
Authors: Megahed Sandra , Fischer Florian , Nell Martin , Forsmark Joy , Leonardi Franco , Zhu Leyi , Hameyer Kay , Schleifenbaum Johannes Henrich
Published: December 2022

Due to the increasing demand for electrification in the automotive sector, the interest in the manufacturing and processing of pure Copper (Cu; purity 99.99%) is also increasing. Laser-based technologies have proven to be challenging due to Cu’s high optical reflectivity. Processing pure Cu with Electron Beam Melting (EBM) is a promising manufacturing route, allowing for high design freedom. The highest priority is to achieve outstanding thermal and electric conductivity in manufactured Cu components. Chemical contamination or manufacturing defects, such as porosity, significantly reduce the thermal and electric conductivity. The literature on post-processing (thermal and abrasive) of additively manufactured Cu is scarce. Therefore, this study discusses the correlation between as built and heat treated microstructure, as well as surface roughness on the EBM electric conductivity. EBSD analysis is performed to analyze the effect of microstructure on electric conductivity. The effect of sandblasting and vibratory finishing on surface roughness and electric conductivity is investigated. Additionally, the samples are mechanically tested in terms of hardness.
The Magnetic Properties and Magnetocaloric Effect of Pr0.7Sr0.3MnO3 Thin Film Grown on SrTiO3 Substrate
Authors: Zhao Bojun , Hu Xiaojie , Dong Fuxiao , Wang Yan , Wang Haiou , Tan Weishi , Huo Dexuan
Published: December 2022

The magnetic behaviors and magnetocaloric effect (MCE) of Pr0.7Sr0.3MnO3 (PSMO-7) film grown on a (001) SrTiO3 single-crystal substrate by a pulsed laser deposition (PLD) were studied in this paper. X-ray diffraction with a high resolution (HRXRD) measurement shows that PSMO-7 film is grown with a (001) single orientation. The magnetic properties and the MCE related to the ferromagnetic (FM) phase transition of the PSMO-7 film are investigated using the temperature dependence of magnetization M(T) and the magnetic field dependence of magnetization M(H). The M(T) data suggest that with decreasing temperatures, the PSMO-7 film goes through the transition from the paramagnetic (PM) state to the FM state at around the Curie temperature (TC). The TC (about 193 K) can be obtained by the linear fit of the Curie law. Magnetic hysteresis loop measurements show that the PSMO-7 film exhibits the FM feature at temperatures of 10, 100, and 150 K (low magnetic hysteresis can be found), while the film reveals the PM feature with the temperature increased up to 200 and/or 300 K. The research results of M(H) data are consistent with the M(T) data. Furthermore, the magnetic entropy change (−ΔSM) of the PSMO-7 film was studied. It was found that the maximum value of (−ΔSM) near TC reaches about 4.7 J/kg·K under the applied field change of 20 kOe, which is comparable to that of metal Gd (−ΔSM of 2.8 J/kg K under 10 kOe), indicating the potential applications of PSMO-7 film in the field of magnetic refrigeration.
Facile One-Pot Synthesis of Nickel Nanoparticles by Hydrothermal Method
Authors: Kim Gawon , Na Chan Woong , Myung Yoon
Published: December 2022

The one-pot synthesis process has emerged as an economical synthesis method without the involvement of purification or formation of intermediate compounds. Therefore, nickel nanoparticles were selectively synthesized by a simple hydrothermal method using nickel(II) chloride hexahydrate and borane–ammonia complex as a precursor and reducing agent, respectively. The morphology and crystal growth were observed by controlling the precursor concentration ratio of Ni:AB from 1:0.1 to 1:4 under various temperatures ranging from 80 to 140 degrees. In addition, we observed that the crystal growth rate under the influence of NaCl and KCl resulted in spherical Ni particles with size distributions controlled in the range of 297.65 nm to 1082.15 nm and 358.6 nm to 605 nm, respectively.
Surface Topography Description of Threads Made with Turning on Inconel 718 Shafts
Authors: Krawczyk Bartłomiej , Szablewski Piotr , Mendak Michał , Gapiński Bartosz , Smak Krzysztof , Legutko Stanisław , Wieczorowski Michał , Miko Edward
Published: December 2022

The technology of producing threads, especially in materials that are difficult to cut, is a rare subject of research and scientific publications. The requirements for the production of these elements apply not only to the geometry, but also to the quality of the surface obtained. This is particularly important in the aviation industry, where the durability of the threaded connection affects passenger safety. Due to the design of the thread, the quality of its surface is assessed visually in industrial practice. The authors of this study decided to examine the surface topography of external threads made by turning on Inconel 718 shafts in order to confirm the visual evaluation, as well as to investigate the influence of such factors as cutting speed, turning direction and type of profile. Three types of contours were cut for the research: triangular, trapezoidal symmetrical and trapezoidal asymmetrical. Turning of each was carried out twice at cutting speeds vc = 17 m/min and vc = 30 m/min. On each of the threads, the side surface of the profile made in the direction of the insert feed and the opposite surface were examined. The surface texture parameters Sa, Sq, Sp, Sv, Sz, Ssk and Sku were determined and compared. It was noticed that the thread surfaces show a tendency to irregular roughness, which was confirmed by the analysis of the Sku and Ssk coefficients. The sides of the contours made in the direction of the insert feed are characterized by a higher roughness in relation to the opposite sides, which may result from high cutting forces and difficulties with chip evacuation. With the cutting speed being considered, lower values of Sa and Sq were obtained for vc = 17 m/min, which differed from the visual assessment, proving its high subjectivity.
Development of New Azomethine Metal Chelates Derived from Isatin: DFT and Pharmaceutical Studies
Authors: Al-Shamry Abdulrhman A. , Khalaf Mai M. , El-Lateef Hany M. Abd , Yousef Tarek A. , Mohamed Gehad G. , El-Deen Kariman M. Kamal , Gouda Mohamed , Abu-Dief Ahmed M.
Published: December 2022

Through the condensation of isatin (indoline-2, 3-dione) and aniline in a 1:1 ratio, a Schiff base ligand was synthesized and characterized via (1H-NMR, mass, IR, UV-Vis) spectra. Elemental analyses, spectroscopy (1H-NMR, mass, UV-Vis), magnetic susceptibility, molar conductivity, mass spectra, scanning electron microscope (SEM), and thermal analysis have all been used to characterize a series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), and Cd(II) metal complexes derived from the titled ligand. The metal-to-ligand ratio is 1:1, according to the analytical data. The Schiff base ligand displayed bidentate behavior with NO coordination sites when it bonded to metal ions, as seen by the IR spectra. The magnetic moment measurement and UV-Vis spectral investigation showed the octahedral geometry of the Cr(III), Fe(III), Co(II), Ni(II), and Zn(II) complexes, whereas they suggested the tetrahedral geometry of the Mn(II), Cu(II), and Cd(II) complexes. The thermal analysis study confirmed the presence of both hydrated and coordinated water molecules in all the compounds, except for the Mn(II) complex, and showed that the complexes decomposed in three or five decomposition steps leaving the corresponding metal oxide as a residue. The ligand and its metal complexes’ antibacterial efficacy were evaluated. The findings showed that the metal complexes had stronger antibacterial properties than the ligand alone. The ligand and its metal complexes’ anticancer properties were also investigated. A DFT investigation is also reported to gather information regarding the electronic features of the ligand and its metal complexes. Finally, drug-likeness and ADME characteristics were also calculated as parameters.
The Effect of the Extrusion Ratio on Load and Die Wear in the Extrusion Process
Authors: Kut Stanisław , Nowotyńska Irena
Published: December 2022

In this paper, regarding the example of concurrent extrusion of a round bar, the results of a comparative analysis of the impact of the extrusion ratio R on process parameters such as die wear intensity, extrusion force, stress intensity in the die, and its elastic deformation during extrusion are presented. The tests were carried out in a wide range of the R (1.5–11), assuming a constant outer diameter of the die. A comparative analysis of the wear was carried out in the area of the die corner radius and the calibration strip since the wear is the highest there. Based on the result obtained, it was shown that the increase in the extrusion force was not proportional to the increase in the extrusion ratio, and this could be described by a logarithmic equation. On the other hand, the value of equivalent stresses in the area of the die corner depends, to a relatively small extent, on the value of the extrusion ratio. However, due to the deformation of the die, it is most advantageous to use an extrusion ratio greater than or equal to three. Based on the wear analysis, it was estimated that the increase in the extrusion ratio R from 3 to 7 caused a more than 2.5 times increase in tool wear. In turn, the implementation of the extrusion process with the use of R = 11 caused a 4.5-fold increase in the average depth of die wear compared to its wear using the extrusion ratio R = 3.
A Study of the Essential Parameters of Friction-Stir Spot Welding That Affect the D/W Ratio of SSM6061 Aluminum Alloy
Authors: Meengam Chaiyoot , Dunyakul Yongyuth , Kuntongkum Siriporn
Published: December 2022

This study aimed to investigate how the depth-to-width (D/W) ratio of the welding area affects the welding quality of the SSM6061 aluminum alloy via the friction-stir spot welding (FSSW) process. The results showed that a higher D/W ratio directly results in better mechanical properties. If the D/W ratio value is high (at 1.494), then this leads to higher tensile shear strength at 2.25 kN. On the other hand, if the D/W ratio values are low (at 1.144), then this reduces tensile shear strength to 1.17 kN. The fracture surface behavior on the ring zone also affects the characteristics of ductile fracture. During Vickers hardness analysis, the hardness profiles are in the shape of a W; the maximum hardness was 71.97 HV, resulting from the rotation speed of 3500 rpm and the dwell time of 28 s, where the hardness of the base metal was at 67.18 HV. Finite element (FEM) analysis indicated that the maximum temperature during simulation was 467 °C in the region near the edge shoulder tool, which is 72.96% of the melting point. According to FEM simulation, the temperature under the tool pin region was 369 °C. The generated heat was sufficient to induce changes in the microstructure. For microstructure changes, the globular grain took on a rosette-like form, and coarse grains were observed in the thermal mechanical affect zone (TMAZ) and in the nugget zone (NZ), transforming in the mix zone. Hooks, kissing bonds, voids, and porosity are the defects found in this experiment. These defects indicate a discontinuity in the NZ that leads to worse mechanical properties. During examination via SEM and energy dispersive X-ray (EDX) analysis, the recrystallization structure from β-Mg2Si IMCs to Al3Mg2 and Al12Mg17 IMCs was observed. The size was reduced to an average width of 1–2 µm and an average length of 2–17 µm. Simultaneously, the oxides from the ambient atmosphere present during welding showed dominant partial elements from SiO2, MgO, and Al2O3.