bluuebunny/crossref_metadata_2025 huggingface dataset:
COVID-19 Vaccine Acceptance among Social Media Users: A Content Analysis, Multi-Continent Study
Authors: Shaaban Ramy , Ghazy Ramy Mohamed , Elsherif Fawzia , Ali Nancy , Yakoub Youssef , Aly Maged Osama , ElMakhzangy Rony , Abdou Marwa Shawky , McKinna Bonny , Elzorkany Amira Mohamed , Abdullah Fatimah , Alnagar Amr , ElTaweel Nashwa , Alharthi Majed , Mohsin Ali , Ordóñez-Cruickshank Ana , Toniolo Bianca , Grafolin Tâmela , Aye Thit Thit , Goh Yong Zhin , Deghidy Ehsan Akram , Bahri Siti , Sappayabanphot Jarntrah , Elhadi Yasir Ahmed Mohammed , Mohammed Salma , El-Deen Ahmed Nour , Ismail Ismail , ElHafeez Samar Abd , Elbarazi Iffat , Saddik Basema , El-Khatib Ziad , Mohsin Hiba , Kamal Ahmed
Published: May 2022

Vaccine hesitancy (VH) is defined as a delayed in acceptance or refusal of vaccines despite availability of vaccination services. This multinational study examined user interaction with social media about COVID-19 vaccination. The study analyzed social media comments in 24 countries from five continents. In total, 5856 responses were analyzed; 83.5% of comments were from Facebook, while 16.5% were from Twitter. In Facebook, the overall vaccine acceptance was 40.3%; the lowest acceptance rates were evident in Jordan (8.5%), Oman (15.0%), Senegal (20.0%) and Morocco (20.7%) and the continental acceptance rate was the lowest in North America 22.6%. In Twitter, the overall acceptance rate was (41.5%); the lowest acceptance rate was found in Oman (14.3%), followed by USA (20.5%), and UK (23.3%) and the continental acceptance rate was the lowest in North America (20.5%), and Europe (29.7%). The differences in vaccine acceptance across countries and continents in Facebook and Twitter were statistically significant. Regarding the tone of the comments, in Facebook, countries that had the highest number of serious tone comments were Sweden (90.9%), USA (61.3%), and Thailand (58.8%). At continent level, serious comments were the highest in Asia (58.4%), followed by Africa (46.2%) and South America (46.2%). In Twitter, the highest serious tone was reported in Egypt (72.2%) while at continental level, the highest proportion of serious comments was observed in Asia (59.7%), followed by Europe (46.5%). The differences in tone across countries and continents in Facebook and Twitter and were statistically significant. There was a significant association between the tone and the position of comments. We concluded that the overall vaccine acceptance in social media was relatively low and varied across the studied countries and continents. Consequently, more in-depth studies are required to address causes of such VH and combat infodemics.
Providing Scale to a Known Taxonomic Unknown—At Least a 70-Fold Increase in Species Diversity in a Cosmopolitan Nominal Taxon of Lichen-Forming Fungi
Authors: Zhang Yanyun , Clancy Jeffrey , Jensen Jacob , McMullin Richard Troy , Wang Lisong , Leavitt Steven D.
Published: May 2022

Robust species delimitations provide a foundation for investigating speciation, phylogeography, and conservation. Here we attempted to elucidate species boundaries in the cosmopolitan lichen-forming fungal taxon Lecanora polytropa. This nominal taxon is morphologically variable, with distinct populations occurring on all seven continents. To delimit candidate species, we compiled ITS sequence data from populations worldwide. For a subset of the samples, we also generated alignments for 1209 single-copy nuclear genes and an alignment spanning most of the mitochondrial genome to assess concordance among the ITS, nuclear, and mitochondrial inferences. Species partitions were empirically delimited from the ITS alignment using ASAP and bPTP. We also inferred a phylogeny for the L. polytropa clade using a four-marker dataset. ASAP species delimitations revealed up to 103 species in the L. polytropa clade, with 75 corresponding to the nominal taxon L. polytropa. Inferences from phylogenomic alignments generally supported that these represent evolutionarily independent lineages or species. Less than 10% of the candidate species were comprised of specimens from multiple continents. High levels of candidate species were recovered at local scales but generally with limited overlap across regions. Lecanora polytropa likely ranks as one of the largest species complexes of lichen-forming fungi known to date.
Four New Highly Oxygenated Eremophilane Sesquiterpenes from an Endophytic Fungus Boeremia exigua Isolated from Fritillaria hupehensis
Authors: Ai Hong-Lian , Lv Xiao , Ye Ke , Wang Meng-Xi , Huang Rong , Shi Bao-Bao , Li Zheng-Hui
Published: May 2022

Four new eremophilane-type sesquiterpenes, boeremialanes A–D (1–4) were obtained from solid substrate cultures of Boeremia exigua (Didymellaceae), an endophytic fungus isolated from Fritillaria hupehensis (Liliaceae). Boeremialanes A–C (1–3) are highly oxygenated eremophilanes with a benzoate unit attached at the C-13 position and are rarely found in nature. Their structures and absolute configurations were determined by extensive spectroscopic methods, electronic circular dichroism (ECD), and nuclear magnetic resonance (NMR) calculations with DP4+ analysis. Boeremialane D (4) potently inhibited nitric oxide production in lipopolysaccharide-treated RAW264.7 macrophages with an IC50 of 8.62 μM and was more potent than the positive control, pyrrolidinedithiocarbamate (IC50 = 23.1 μM).
Dysosmia Is a Predictor of Motor Function and Quality of Life in Patients with Parkinson’s Disease
Authors: Lin Chia-Yen , Chang Ting-Ya , Chang Ming-Hong
Published: May 2022

(1) Background: The correlation between dysosmia with quality of life (QoL) in patients with PD was rarely reported. The study aimed to examine the effect of dysosmia on motor function and QoL in PD. (2) Methods: This cross-sectional study, performed between October 2016 and February 2021, recorded the traditional Chinese version of the University of Pennsylvania Smell Identification Test (UPSIT), the Montreal Cognitive Assessment (MoCA), the Movement Disorder Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale (MDS UPDRS), and the 39-item Parkinson’s Disease Questionnaire (PDQ-39) in patients with PD. UPSIT = 19 was applied to separate the total anosmia and non-anosmia groups. (3) Results: 243 patients with PD were recruited. The total anosmia group had higher MDS UPDRS total, part II, and part III scores than the non-anosmia group. They also had worse scores on the dimensions of activities of daily living (ADL) and cognition of the PDQ-39 than the non-anosmia group. The UPSIT score correlated MDS UPDRS part III score (p < 0.0001), PDQ-39 ADL quartile (p = 0.0202), and Dopamine transporter scan (p = 0.0082) in the linear regression. (4) Conclusions: Dysosmia in PD predicted a phenotype with defective motor function, ADL, and cognition QoL. The findings supported the olfactory transmission of α-synuclein to the cortices, substantia nigra.
Assessing the Need for Semantic Data Integration for Surgical Biobanks—A Knowledge Representation Perspective
Authors: Brochhausen Mathias , Whorton Justin M. , Zayas Cilia E. , Kimbrell Monica P. , Bost Sarah J. , Singh Nitya , Brochhausen Christoph , Sexton Kevin W. , Blobel Bernd
Published: May 2022

To improve patient outcomes after trauma, the need to decrypt the post-traumatic immune response has been identified. One prerequisite to drive advancement in understanding that domain is the implementation of surgical biobanks. This paper focuses on the outcomes of patients with one of two diagnoses: post-traumatic arthritis and osteomyelitis. In creating surgical biobanks, currently, many obstacles must be overcome. Roadblocks exist around scoping of data that is to be collected, and the semantic integration of these data. In this paper, the generic component model and the Semantic Web technology stack are used to solve issues related to data integration. The results are twofold: (a) a scoping analysis of data and the ontologies required to harmonize and integrate it, and (b) resolution of common data integration issues in integrating data relevant to trauma surgery.
Study of the Association between VEGF Polymorphisms and the Risk of Coronary Artery Disease in Koreans
Authors: Ko Eun-Ju , Kim In-Jai , Lee Jeong-Yong , Park Hyeon-Woo , Park Han-Sung , Kim Sang-Hoon , Moon Jae-Youn , Sung Jung-Hoon , Kim Nam-Keun
Published: May 2022

Coronary artery disease (CAD), a leading cause of death worldwide, has a complex etiology comprising both traditional risk factors (type 2 diabetes, dyslipidemia, arterial hypertension, and cigarette smoking) and genetic factors. Vascular endothelial growth factor (VEGF) notably contributes to angiogenesis and endothelial homeostasis. However, little is known about the relationship between CAD and VEGF polymorphisms in Koreans. The aim of this study is to investigate the associations of 2 VEGF promoter region polymorphisms (−1154G>A [rs1570360], −1498T>C [rs833061]) and 4 VEGF 3′-UTR polymorphisms (+936C>T [rs3025039], +1451C>T [rs3025040], +1612G>A [rs10434], and +1725G>A [rs3025053]) with CAD susceptibility in Koreans. We studied 885 subjects: 463 CAD patients and 422 controls. Genotyping was conducted with polymerase chain reaction-restriction fragment length polymorphism analysis and TaqMan allelic discrimination assays, and the genotype frequencies were calculated. We then performed haplotype and genotype combination analyses and measured the associations between VEGF polymorphisms and clinical variables in both the CAD patients and control subjects. We detected statistically significant associations between CAD and certain VEGF allele combinations. In the haplotypes of 5 single-nucleotide polymorphisms, the VEGF allele combination −1154A/+936T was associated with a decreased prevalence of CAD (A-T-T-G-G of VEGF −1154G>A/−1498T>C/+936C>T/+1612G>A/+1725G>A, AOR = 0.077, p = 0.021). In contrast, the VEGF allele combinations −1498T/+1725A and −1498T/+1612A/+1725A were associated with an increased prevalence of CAD (G-T-C-C-A of VEGF −1154G>A/−1498T>C/+936C>T/+1451C>T/+1725G>A, AOR = 1.602, p = 0.047; T-C-C-A-A of VEGF −1498T>C/+936C>T/+1451C>T/+1612G>A/+1725G>A, AOR = 1.582, p = 0.045). Gene–environment combinatorial analysis showed that the combination of the VEGF +1725AA genotype and several clinical factors (e.g., body mass index, hemoglobin A1c, and low-density lipoprotein cholesterol) increased the risk of CAD. Therefore, we suggest that VEGF polymorphisms and clinical factors may impact CAD prevalence.
Willingness to Communicate and Second Language Fluency: Korean-Speaking Short-Term Sojourners in Australia
Authors: Kim Jeongmin , Zhao Helen , Diskin-Holdaway Chloé
Published: May 2022

The current mixed-method study investigated two groups of Korean-speaking short-term sojourners in Australia. One group (students) was composed of learners enrolled in English training programs, whereas the other group (workers) was of learners in the workplace. We administered questionnaires and a semi-structured interview to examine their willingness to communicate (WTC) in English as their second language (L2) and explored the relationship between this variable and the sojourners’ amount of L2 contact and their oral fluency in English. Our quantitative analyses show that the student group showed a higher level of WTC and amount of L2 exposure than the worker group. For both groups, WTC significantly predicted sojourners’ amount of L2 exposure. However, oral fluency was found neither to be associated with WTC nor with the amount of L2 exposure. Qualitative theme-based analysis suggests that the two sojourn groups demonstrated similarities and differences in their attitudes and motivations related to WTC and unwillingness to communicate (unWTC). The students demonstrated a stronger tendency to engage in L2 interaction than the workers, aligning with their significantly higher frequency of reported L2 exposure. The workers’ attitudes were characterized by feelings of ambivalence, with co-existence of both WTC and unWTC.
Multiplexed Promoter Engineering for Improving Thaxtomin A Production in Heterologous Streptomyces Hosts
Authors: Zhao Xuejin , Zong Yeqing , Wei Weijia , Lou Chunbo
Published: May 2022

Thaxtomin A is a potent bioherbicide in both organic and conventional agriculture; however, its low yield hinders its wide application. Here, we report the direct cloning and heterologous expression of the thaxtomin A gene cluster in three well-characterized Streptomyces hosts. Then, we present an efficient, markerless and multiplex large gene cluster editing method based on in vitro CRISPR/Cas9 digestion and yeast homologous recombination. With this method, we successfully engineered the thaxtomin A cluster by simultaneously replacing the native promoters of the txtED operon, txtABH operon and txtC gene with strong constitutive promoters, and the yield of thaxtomin A improved to 289.5 µg/mL in heterologous Streptomyces coelicolor M1154. To further optimize the biosynthetic pathway, we used constraint-based combinatorial design to build 27 refactored gene clusters by varying the promoter strength of every operon, and the highest titer of thaxtomin A production reached 504.6 μg/mL. Taken altogether, this work puts forward a multiplexed promoter engineering strategy to engineer secondary metabolism gene clusters for efficiently improving fermentation titers.
Endothelial EphrinB2 Regulates Sunitinib Therapy Response in Murine Glioma
Authors: Broggini Thomas , Stange Lena , Lucia Kristin Elizabeth , Vajkoczy Peter , Czabanka Marcus
Published: May 2022

Vascular guidance is critical in developmental vasculogenesis and pathological angiogenesis. Brain tumors are strongly vascularized, and antiangiogenic therapy was anticipated to exhibit a strong anti-tumor effect in this tumor type. However, vascular endothelial growth factor A (VEGFA) specific inhibition had no significant impact in clinical practice of gliomas. More research is needed to understand the failure of this therapeutic approach. EphrinB2 has been found to directly interact with vascular endothelial growth factor receptor 2 (VEGFR2) and regulate its activity. Here we analyzed the expression of ephrinB2 and EphB4 in human glioma, we observed vascular localization of ephrinB2 in physiology and pathology and found a significant survival reduction in patients with elevated ephrinB2 tumor expression. Induced endothelial specific depletion of ephrinB2 in the adult mouse (efnb2i∆EC) had no effect on the quiescent vascular system of the brain. However, we found glioma growth and perfusion altered in efnb2i∆EC animals similar to the effects observed with antiangiogenic therapy. No additional anti-tumor effect was observed in efnb2i∆EC animals treated with antiangiogenic therapy. Our data indicate that ephrinB2 and VEGFR2 converge on the same pathway and intervention with either molecule results in a reduction in angiogenesis.
Liver Trauma: Until When We Have to Delay Surgery? A Review
Authors: García Inés Cañas , Villalba Julio Santoyo , Iovino Domenico , Franchi Caterina , Iori Valentina , Pettinato Giuseppe , Inversini Davide , Amico Francesco , Ietto Giuseppe
Published: May 2022

Liver involvement after abdominal blunt trauma must be expected, and in up to 30% of cases, spleen, kidney, and pancreas injuries may coexist. Whenever hemodynamics conditions do not contraindicate the overcoming of the ancient dogma according to which exploratory laparotomy should be performed after every major abdominal trauma, a CT scan has to clarify the liver lesions so as to determine the optimal management strategy. Except for complete vascular avulsion, no liver trauma grade precludes nonoperative management. Every attempt to treat the injured liver by avoiding a strong surgical approach may be considered. Each time, a nonoperative management (NOM) consisting of a basic “wait and see” attitude combined with systemic support and blood replacement are inadequate. Embolization should be considered to stop the bleeding. Percutaneous drainage of collections, endoscopic retrograde cholangiopancreatography (ERCP) with papilla sphincterotomy or stent placement and percutaneous transhepatic biliary drainage (PTBD) may avoid, or at least delay, surgical reconstruction or resection until systemic and hepatic inflammatory remodeling are resolved. The pathophysiological principle sustaining these leanings is based on the opportunity to limit the further release of cell debris fragments acting as damage-associated molecular patterns (DAMPs) and the following stress response associated with the consequent immune suppression after trauma. The main goal will be a faster recovery combined with limited cell death of the liver through the ischemic events that may directly follow the trauma, exacerbated by hemostatic procedures and surgery, in order to reduce the gross distortion of a regenerated liver.
Correction: Danner et al. It More than Adds Up: Interaction of Antibiotic Mixing and Temperature. Life 2021, 11, 1435
Authors: Danner Marie-Claire , Azams Sharon Omonor , Robertson Anne , Perkins Daniel , Behrends Volker , Reiss Julia
Published: May 2022

The Authors wish to make the following corrections to this paper [...]
Genetic Association between TNFA Polymorphisms (rs1799964 and rs361525) and Susceptibility to Cancer in Systemic Sclerosis
Authors: Kosałka-Węgiel Joanna , Lichołai Sabina , Dziedzina Sylwia , Milewski Mamert , Kuszmiersz Piotr , Rams Anna , Gąsior Jolanta , Matyja-Bednarczyk Aleksandra , Kwiatkowska Helena , Korkosz Mariusz , Siwiec Andżelika , Koźlik Paweł , Padjas Agnieszka , Sydor Wojciech , Dropiński Jerzy , Sanak Marek , Musiał Jacek , Bazan-Socha Stanisława
Published: May 2022

Tumor necrosis factor (TNF)-α is a proinflammatory cytokine that plays an important role in the pathogenesis of autoimmune diseases. The aim of the study was to establish an association between TNF-α promoter variability and systemic sclerosis (SSc). The study included 43 SSc patients and 74 controls. Four single nucleotide polymorphisms (rs361525, rs1800629, rs1799724, and rs1799964) located at the promoter of the TNFA gene were genotyped using commercially available TaqMan allelic discrimination assays with real-time PCR. The rs1799724 allele was associated with an increased SSc susceptibility (p = 0.028). In turn, none of the polymorphisms studied were related to the clinical and laboratory parameters of SSc patients, except for a higher prevalence of anti-Ro52 antibodies in the AG rs1800629 genotype in comparison to GG carriers (p = 0.04). Three of four cancer patients had both CT rs1799964 and AG rs361525 genotypes; thus, both of them were related to the increased risk of cancer, as compared to the TT (p = 0.03) and GG carriers (p = 0.0003), respectively. The TNFA C rs1799724 variant is associated with an increased risk of SSc, while the CT rs1799964 and AG rs361525 genotypes might enhance cancer susceptibility in SSc patients, although large observational and experimental studies are needed to verify the above hypothesis.
Integrated Analysis of the Altered lncRNA, microRNA, and mRNA Expression in HBV-Positive Hepatocellular Carcinoma
Authors: Yu Jingya , Zhang Haibin , Zhang Yan , Zhang Xiaolu
Published: May 2022

Hepatitis B virus (HBV) infection is the most prominent risk factor for developing hepatocellular carcinoma (HCC), which can increase the incidence of HCC by more than 100 times. Accumulated evidence has revealed that non-coding RNAs (ncRNAs) play a regulatory role in various tumors through the long non-coding RNA (lncRNA)–microRNA (miRNA)–mRNA regulation axis. However, the involvement of the ncRNA regulatory network in the progression of HBV infection-induced HCC remains elusive. In the current work, five tumor samples from patients with hepatitis B surface antigen (HBsAg)-positive HCC and three tumor samples from patients with HBsAg-negative HCC were collected for whole-transcriptome sequencing. Between the two groups, 841 lncRNAs, 54 miRNAs, and 1118 mRNAs were identified to be differentially expressed (DE). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses indicated that DE genes were mainly involved in cancer-related pathways, including Wnt and MAPK signaling pathways. The Gene Expression Omnibus (GEO) analysis further validated the selected DE mRNAs. The DE lncRNA–miRNA–mRNA network was built to explore the effect of HBV infection on the regulation of ncRNAs in HCC. These findings provide novel insights into the role of HBV infection in the progression of HCC.
Variation in Plasma Levels of Apixaban and Rivaroxaban in Clinical Routine Treatment of Venous Thromboembolism
Authors: Reda Sara , Rudde Eva , Müller Jens , Hamedani Nasim Shahidi , Oldenburg Johannes , Pötzsch Bernd , Rühl Heiko
Published: May 2022

Direct oral anticoagulants (DOACs) apixaban and rivaroxaban are broadly used in the management of venous thromboembolism (VTE). Although not routinely required, measurement of their plasma concentration is advised for an increasing number of indications. Due to the lack of therapeutic ranges, current guidelines recommend reporting DOAC plasma levels together with expected levels from previous pivotal studies. The aim of this study was to assess DOAC level variation in a large VTE patient population. Drug concentrations determined by measurement of the anti-Xa-activity using drug-specific calibrators in citrated plasma samples from patients on rivaroxaban (n = 1471) or apixaban (n = 725) were analyzed. Observed 5th–95th percentile ranges of apixaban peak/trough levels (63–299/13–114 ng/mL for 5 mg, 37–161/7–68 ng/mL for 2.5 mg twice daily) were similar to previously reported mass-spectrometry-based reference data, and 10th–90th percentile ranges of rivaroxaban peak/trough levels (98–367/8–55 ng/mL for 20 mg, 51–211/5–27 ng/mL for 10 mg once daily) were even narrower. Age and drug levels correlated weakly (r ≤ 0.330). Drug levels measured repeatedly in subgroups of patients showed a strong correlation (r ≥ 0.773). In conclusion, anti-Xa-activity-based measurement of apixaban and rivaroxaban yields reliable results. However, the paucity of levels off-range underlines the need for evidence-based thresholds to better assist clinical decision making.
The Impact of Weight Loss during Chemoradiotherapy for Unresectable Esophageal Cancer: Real-World Results
Authors: Huang Tzu-Ting , Chou Shang-Yu , Lin Yun-Hsuan , Li Shau-Hsuan , Chen Yen-Hao , Lu Hung-I , Lo Chien-Ming , Fang Fu-Min , Chiu Yi-Chun , Chou Yeh-Pin , Wang Yu-Ming
Published: May 2022

Weight loss is a common phenomenon presented in unresectable esophageal cancer (EC) patients during their definitive chemoradiotherapy (dCRT) treatment course. This study explored the prognostic value of weight changes during dCRT in unresectable EC patients. From 2009 to 2017, 69 cT4b thoracic EC patients undergoing complete curative dCRT without baseline malnutrition were included. Clinical factors were analyzed via the Cox proportional hazards model and survival was analyzed by the Kaplan–Meier method. During dCRT, the median weight loss percentage was 5.51% (IQR = 2.77–8.85%), and the lowest body weight was reached at 35 days (IQR = 23–43 days). Median OS of these patients was 13.5 months. Both univariate and multivariate analysis demonstrated that weight loss ≤ 4% during dCRT was significantly associated with superior OS with a hazard ratio of 2.61 (95% CI: 1.40–4.85, p = 0.002). The median OS for patients with weight loss ≤ 4% and >4% during dCRT was 59.6 months and 9.7 months, respectively (p = 0.001). Our study demonstrated that weight loss ≤ 4% during dCRT course is a favorable prognostic factor for cT4b EC patients. This index could serve as a nutrition support reference for unresectable EC patients receiving dCRT in the future.
Evaluation of the High- and Low-Temperature Performance of Asphalt Mortar Based on the DMA Method
Authors: Wang Yanzhu , Wang Xudong , Ma Zhimin , Shan Lingyan , Zhang Chao
Published: May 2022

Asphalt mortar is a typical temperature-sensitive material that plays a crucial role in the performance of asphalt mixture. This study evaluates the high- and low-temperature performance of asphalt mortar based on the dynamic mechanical analysis (DMA) method. Temperature-sweep tests of asphalt mortars were conducted using the DMA method under fixed strain level, frequency, and heating rate conditions. The dynamic mechanical response curves, characteristic temperature, and other indices were obtained and used to investigate the high- and low-temperature performance of asphalt mortar. The results showed that the phase transition temperatures T1, T0, and Tg can be used to evaluate the low-temperature performance of asphalt mortar. Additionally, they had a good linear relationship, and the evaluation results were consistent. Meanwhile, T2, E60, and tan(δ)max indicators can effectively evaluate the high-temperature performance of asphalt mortar. Asphalt plays a key role in the performance of asphalt mortar. Mortars with neat asphalt A70 and modified asphalt AR had the worst and best high- and low-temperature performances, respectively. Furthermore, the finer gradation improved the low-temperature performance of asphalt mortar, while the coarser gradation improved the high-temperature properties of modified asphalt mortars but had the opposite effect on neat asphalt A70.
Sulfate Freeze–Thaw Resistance of Magnesium Potassium Phosphate Cement Mortar
Authors: Yang Bin , Ji Rong-Jian , Lan Qian , Yang Jian-Ming , Xu Jun
Published: May 2022

Concrete facilities in the severe-cold areas of western China (salt lake environments and heavy saline soils) are seriously damaged by the multiple corrosion effects of freeze–thaw cycles and sulfate corrosion. Magnesium phosphate cement (MPC) cement-based material has become an ideal concrete structural component because of its superior performance. Because concrete structural repair materials are used in heavy-corrosion environments, their durability in those environments should also be considered. Regarding the salt-freezing resistance of MPC, the existing studies have all used a NaCl solution as the heat transfer medium. In addition to chlorine salt, sulfate, especially Na2SO4, is also common in typical use environments such as oceans, salt lakes, and groundwater. To evaluate the sulfate freeze–thaw resistance of potassium magnesium phosphate cement (MKPC) mortar, in this study the strength development, weight loss, and water absorption of MKPC mortar specimens subjected to different freeze–thaw cycles were tested and compared with those for Portland cement (P.O) mortar specimens of the same strength grade. The results showed that the P.O mortar specimen completely lost its strength after 75 cycles of rapid water freezing and thawing and 50 cycles of sodium sulfate solution (5%) freezing and thawing. However, the residual strength rating of the MKPC mortar specimen after 75 cycles of water freezing and thawing and 100 cycles of sodium sulfate solution freezing and thawing was higher than 75%. After 50 rapid freeze–thaw cycles in water and a 5% Na2SO4 solution, the P.O mortar specimen’s mass loss exceeded the 5% failure standard, whereas the mass loss of the MKPC mortar specimens was much less than 5%. Before the freeze–thaw cycles, the water absorption of the P.O mortar specimen was close to 8 times that of the MKPC mortar specimen, and after 50 water freeze–thaw cycles and 25 sulfate solution freeze–thaw cycles, the water absorption reached 4.88% and 5.68%, respectively. However, after 225 freeze–thaw cycles in water and the sulfate solution, the water absorption rates of MKPC mortar specimens were 2.91% and 2.51% respectively. The test and analysis results show that the freeze–thaw resistance of MKPC mortar was much higher than that of Portland cement mortar specimens. Those results provide a prerequisite for applying and expanding the use of MKPC-based materials in severe-cold areas of western China (salt lake and heavily saline soil environments).
GIPAW Pseudopotentials of d Elements for Solid-State NMR
Authors: Tantardini Christian , Kvashnin Alexander G. , Ceresoli Davide
Published: May 2022

Computational methods are increasingly used to support interpreting, assigning and predicting the solid-state nuclear resonance magnetic spectra of materials. Currently, density functional theory is seen to achieve a good balance between efficiency and accuracy in solid-state chemistry. To be specific, density functional theory allows the assignment of signals in nuclear resonance magnetic spectra to specific sites and can help identify overlapped or missing signals from experimental nuclear resonance magnetic spectra. To avoid the difficulties correlated to all-electron calculations, a gauge including the projected augmented wave method was introduced to calculate nuclear resonance magnetic parameters with great success in organic crystals in the last decades. Thus, we developed a gauge including projected augmented pseudopotentials of 21 d elements and tested them on, respectively, oxides or nitrides (semiconductors), calculating chemical shift and quadrupolar coupling constant. This work can be considered the first step to improving the ab initio prediction of nuclear magnetic resonance parameters, and leaves open the possibility for inorganic compounds to constitute an alternative standard compound, with respect to tetramethylsilane, to calculate the chemical shift. Furthermore, this work represents the possibility to obtain results from first-principles calculations, to train a machine-learning model to solve or refine structures using predicted nuclear magnetic resonance spectra.
PCL/Si-Doped Multi-Phase Calcium Phosphate Scaffolds Derived from Cuttlefish Bone
Authors: Ressler Antonia , Bauer Leonard , Prebeg Teodora , Ledinski Maja , Hussainova Irina , Urlić Inga , Ivanković Marica , Ivanković Hrvoje
Published: May 2022

Increasing attention is focused on developing biomaterials as temporary scaffolds that provide a specific environment and microstructure for bone tissue regeneration. The aim of the present work was to synthesize silicon-doped biomimetic multi-phase composite scaffolds based on bioactive inorganic phases and biocompatible polymers (poly(ε-caprolactone), PCL) using simple and inexpensive methods. Porous multi-phase composite scaffolds from cuttlefish bone were synthesized using a hydrothermal method and were further impregnated with (3-aminopropyl)triethoxysilane 1–4 times, heat-treated (1000 °C) and coated with PCL. The effect of silicon doping and the PCL coating on the microstructure and mechanical and biological properties of the scaffolds has been investigated. Multi-phase scaffolds based on calcium phosphate (hydroxyapatite, α-tricalcium phosphate, β-tricalcium phosphate) and calcium silicate (wollastonite, larnite, dicalcium silicate) phases were obtained. Elemental mapping revealed homogeneously dispersed silicon throughout the scaffolds, whereas silicon doping increased bovine serum albumin protein adsorption. The highly porous structure of cuttlefish bone was preserved with a composite scaffold porosity of ~78%. A compressive strength of ~1.4 MPa makes the obtained composite scaffolds appropriate for non-load-bearing applications. Cytocompatibility assessment by an MTT assay of human mesenchymal stem cells revealed the non-cytotoxicity of the obtained scaffolds.
Effect of Polyimide-Phosphating Double Coating and Annealing on the Magnetic Properties of Fe-Si-Cr SMCs
Authors: Long Haiming , Wu Xiaojie , Lu Yunkun , Zhang Haifeng , Hao Junjie
Published: May 2022

Fe-Si-Cr soft magnetic powder cores (SMCs), with high electrical resistivity, magnetic permeability, saturation magnetic induction, and good corrosion resistance, are widely applied to inductors, filters, choke coils, etc. However, with the development of electronic technology with high frequency and high power density, the relative decline in the magnetic properties limits the high-frequency application of SMCs. In this paper, the phosphating process and polyimide (PI) insulation coating is applied to Fe-Si-Cr SMCs to reduce the core loss, including hysteresis loss and eddy current loss. The microstructure and composition of Fe-Si-Cr powders were analyzed by SEM, XRD, and Fourier-transform infrared spectra, respectively. The structural characteristics of the Fe-Si-Cr @ phosphate layer @ PI layer core–shell double coating were studied, and the best process parameters were determined through experiments. For SMCs with 0.4 wt% content of PI, the relative permeability is greater than 68%, and the core loss is the lowest, 7086 mW/cm3; annealed at 500 °C, the relative permeability is greater than 57%, and the core loss is the lowest, 6222 mW/cm3. A 0.4 wt% content of PI, annealed at 500 °C, exhibits the ideal magnetic properties: μe = 47 H/m, P = 6222 mW/cm3.
A Facile Fabrication of CdSe/ZnS QDs—Block Copolymer Brushes-Modified Graphene Oxide Nanohybrid with Temperature-Responsive Behavior
Authors: Song Yajiao , Yu Hongcui , Wang Xiaohui , Liu Jinglin , Liu Jinghai
Published: May 2022

In this paper, we described a straightforward one-step chemical method for the synthesis of semiconductor quantum dots(QDs)—block copolymer brushes functionalized graphene oxide(GO) fluorescence nanohybrids. The azobenzene-terminated block copolymer poly(N-isopropylacrylamid)-b-poly(styrene-co-5-(2-methacryoylethyloxymethyl)-8-quinolinol)(PNIPAM-b-P(St-co-MQ)) was modified on the surface of GO sheets via host–guest interactions between β-cyclodextrin-modified GO and azobenzene moieties, and simultaneously CdSe/ZnS QDs were integrated on the block copolymer brushes through the coordination between 8-hydroxyquinoline units in the polymer brushes and CdSe/ZnS QDs. The resulting fluorescence nanohybrid exhibited dual photoluminescence at 620 nm and 526 nm, respectively, upon excitation at 380 nm and LCST-type thermo-responsive behavior which originated from the change in the PNIPAM conformation in the block copolymer brushes of GO sheets.
A Highly Effective, UV-Curable, Intumescent, Flame-Retardant Coating Containing Phosphorus, Nitrogen, and Sulfur, Based on Thiol-Ene Click Reaction
Authors: Li Wenqian , Dou Yanli , Li Xuefei , Fang Shengbo , Li Jian , Li Quanming
Published: May 2022

In this paper, a flame-retardant, UV-cured coating was prepared on the fiber composites’ (FC) surface via a thiol-ene click reaction using pentaerythritol tetra(3-mercaptopropionate) (PETMP), triallyl cyanurate (TAC), and 2-hydroxyethyl methacrylate phosphate (PM-2). The synergistic effectiveness of phosphorus (P), nitrogen (N), and sulfur (S) was studied in detail by changing the proportion of these reactants. Sample S4(N3P2)6, with a molar ratio of N and P elements of 3:2, and the thiol and vinyl groups of 4:6 had the highest LOI value (28.6%) and was self-extinguishing in the horizontal combustion test. It had the lowest peak heat release rate (PHRR) value (279.25 kW/m2) and total smoke production (2.18 m2). Moreover, the thermogravimetric analysis (TG) showed that the decomposition process of the coated composites was delayed. The conversion rate of the double bond and the thiol of S4(N3P2)6 was 100% and 92.0%, respectively, which showed that the cross-linked network structure was successfully formed. The tensile strength and the flexural strength of coated composites improved, and the transparency of the coating can reach 90%. These characteristics showed that the UV-cured coatings could be used in industrial production to effectively prevent fires.
Design and Preparation of White High-Strength Concrete with Ground Limestone Powder by Means of Response Surface Methodology
Authors: Xia Jingliang , Cao Changwei , Jiang Zhengwu , Ren Qiang , Zhang Ying , Wang Jing , Leng Faguang
Published: May 2022

This paper investigates the properties of white high-strength concrete (WHSC) prepared with ground limestone powder (GLP). Response surface methodology (RSM) was used to design the proportions of mixes and evaluate the influence of the water–binder ratio (w/b), slurry volume fraction (Vs), and the content of GLP in a binder (Cg) on the slump, whiteness and compressive strength of WHSC via Box–Behnken equations. Results indicate that quadratic polynomial regression equations can be used to predict the performance of WHSC as influenced by combined factors. Both slump and compressive strength of WHSC are found highly influenced by w/b while GLP significantly improves the whiteness of WHSC. An optimal mix proportion of WHSC is provided by the multi-objective optimization with high-accuracy predictions. This paper demonstrates the feasibility of preparing WHSC with GLP and presents the potential of using RSM in the mix proportioning of concrete.
Comparative Analysis of Mine Shaft Hoisting Systems’ Brake Temperature Using Finite Element Analysis (FEA)
Authors: Popescu Florin Dumitru , Radu Sorin Mihai , Andraș Andrei , Brînaș Ildiko , Budilică Daniela Ioana , Popescu Valentin
Published: May 2022

This paper studies both the thermal and mechanical behavior of brake system models in the case of the emergency braking of a mine hoist model. Using a step-by-step approach inspired by studies conducted on small brake systems with high rotation speeds specific to road and rail vehicles, a comparative analysis using a computer simulation was performed for the two types of brakes of a mine hoist system. A Solidworks model was built for two configurations: the drum-and-shoe and the disc-and-pads, and it was imported to COMSOL Multiphysics, where the material properties and simulation parameters were defined. Simulations were performed for each configuration, first using a Heat transfer module in the solids to investigate the frictional heat. The results showed the locations of the hot points on the disc and on the drum, with the surface temperature reaching 97 °C on the disc and 115 to 159 °C on the drum. Next, simulations using a Structural Mechanics module were run to obtain the stress and deformation induced by the heat generated during braking. The von Mises stress of the drum-and-shoe brake occurred on the external surface of the drum and had a value of 2 × 108 N/m2. For the disc-and-pad brake, the stress occurred towards the edges of the brake pad contact and was 4 × 108 N/m2. Both values were under the yield stress of the passive brake element material. Regarding the deformations, for the drum-and-shoe brake, it appeared towards the outer boundary of the drum, being 0.45 mm, and for the disc-and-pad brake, it was situated at the external edge of the disc, being 0.25 mm. COMSOL Multiphysics allowed the evaluation of the thermo-mechanical behavior using noninvasive techniques since actual emergency braking testing on a working mine hoisting installation is not possible because of safety and logistic concerns.
Analysis of Non-Metallic Inclusions by Means of Chemical and Electrolytic Extraction—A Review
Authors: Ramesh Babu Shashank , Michelic Susanne Katharina
Published: May 2022

Research on non-metallic inclusions is of critical importance, as they have a significant influence on the final properties of steel products. In this regard, the 3D analysis of inclusions isolated from steel samples allows for the accurate measurement of their chemical composition, without the influence of the steel matrix, and detailed insights into their morphology. Inclusions can be extracted from the steel sample matrix using extraction methods followed by their measurement with scanning electron microscopy. Extraction methods can be broadly classified into chemical and electrolytic analyses. There have been numerous studies documenting the different extraction methods for the isolation of different inclusion types in a range of steels. The focus of this paper is to briefly review their developments over a century up until the present period. The most relevant methods and the corresponding steels and observed inclusions are also summarized in a table which could be a useful reference for researchers in this field.
Advantages of Cubosomal Formulation for Gatifloxacin Delivery in the Treatment of Bacterial Keratitis: In Vitro and In Vivo Approach Using Clinical Isolate of Methicillin-Resistant Staphylococcus aureus
Authors: Nasr Mohamed , Saber Sameh , Bazeed Alaa Y. , Ramadan Heba A. , Ebada Asmaa , Ciorba Adela Laura , Cavalu Simona , Elagamy Heba I.
Published: May 2022

The objective of this study was to enhance the corneal permeation of gatifloxacin (GTX) using cubosomal nanoparticle as a delivery system. Cubosomal nanoparticle loaded with GTX was prepared and subjected for in vitro and in vivo investigations. The prepared GTX-loaded cubosomal particles exhibited nanoparticle size of 197.46 ± 9.40 nm and entrapment efficiency of 52.8% ± 2.93. The results of ex vivo corneal permeation of GTX-loaded cubosomal dispersion show approximately 1.3-fold increase compared to GTX aqueous dispersion. The incorporation of GTX into cubosomal particles resulted in a fourfold reduction in the minimum inhibitory concentration (MIC) value for the GTX cubosomal particles relative to GTX aqueous dispersion. Furthermore, the enhanced corneal penetration of GTX-loaded cubosomal dispersion compared was evident by a significant decrease in the area % of corneal opacity in MRSA infected rats. Moreover, these results were confirmed by photomicrographs of histological structures of corneal tissues from rats treated with GTX-cubosomal dispersion which did not present any change compared to that of the normal rat corneas. In conclusion, treatment of ocular bacterial infections and reduction in the probability of development of new resistant strains of MRSA could be accomplished with GTX-loaded cubosomal nanoparticles.
Structure, Spectra, Morphology, and Magnetic Properties of Nb5+ Ion-Substituted Sr Hexaferrites
Authors: Zhang Wenhao , Li Pengwei , Wang Yonglun , Guo Jing , Li Jie , Shan Shuo , Ma Saisai , Suo Xing
Published: May 2022

SrFe12−xNbxO19 (x = 0.00–0.15) was here synthesized by a conventional solid-state reaction method. Thermogravimetry and differential scanning calorimetry curves revealed the sample reactions at four temperature ranges, and the optimal reaction stability was obtained at 1240 °C. A single-phase polycrystalline form of SrFe12O19 was obtained until the substitution reached 0.09, and the average crystallite size was found to be in the range of 44.21–60.02 nm. According to Fourier-transform infrared spectra, the formation of Fe–O bonds occurred at 69 and 450 cm−1 in the M-type ferrite, while Raman spectra revealed that all the peaks in the sample corresponded to Raman vibration modes and M-type structures. Through the shift of the peaks, it is speculated that Nb5+ enters into the lattice. The hysteresis loops of the samples were measured by vibrating-sample magnetometry, and the calculated results demonstrated that the coercivity increased with increases in the doping amount (686.3 Oe). At the same time, the saturation magnetization remained at a large value (>72.49 emu/g), which has rarely been reported.
The Structure of Biologically Active Functionalized Azoles: NMR Spectroscopy and Quantum Chemistry
Authors: Larina Lyudmila
Published: May 2022

This review summarizes the data on the stereochemical structure of functionalized azoles (pyrazoles, imidazoles, triazoles, thiazoles, and benzazoles) and related compounds obtained by multipulse and multinuclear 1H, 13C, 15N NMR spectroscopy and quantum chemistry. The stereochemistry of functionalized azoles is a challenging topic of theoretical research, as the correct interpretation of their chemical behavior and biological activity depends on understanding the factors that determine the stereochemical features and relative stability of their tautomers. NMR spectroscopy, in combination with quantum chemical calculations, is the most convenient and reliable approach to the evaluation of the stereochemical behavior of, in particular, nitrogen-containing heteroaromatic and heterocyclic compounds. Over the last decade, 15N NMR spectroscopy has become almost an express method for the determination of the structure of nitrogen-containing heterocycles.
The Influence of Precipitation Hardening on the Damping Capacity in Al–Si–Mg Cast Components at Different Strain Amplitudes
Authors: Carneiro Vitor H. , Grilo José , Soares Delfim , Duarte Isabel , Puga Hélder
Published: May 2022

An A356 alloy is a classic casting light alloy, which is able to be processed into complex geometrical shapes with tailored static and dynamic mechanical properties. As a promising material to reduce fuel and energy consumption in future vehicle designs, there is an interest in understanding the impact of heat treatments on the damping capacity of this alloy. The Granato–Lücke theory is used to detail the forced vibration response in gravity cast A356. It is shown that a solution treatment enhances damping capacity in lower stress states (i.e., strain-independent regime) due to the increase in weak pinning length. However, in high-stress states (i.e., strain-dependent regime), peak-aged (T6) samples display higher damping capacity. This is proposed to be originated by releasing dislocations from weak pinning points, which start bowing in the precipitates that act as strong pinning points. Based on these results, it is shown for the first time that the selection of heat treatments to optimize damping in forced vibration is highly dependent on the expected stress–strain state and must be considered in the design of cast components.
A Reliability Analysis Framework of Ship Local Structure Based on Efficient Probabilistic Simulation and Experimental Data Fusion
Authors: Xiao Shuming , Han Yang , Zhang Yi , Wei Qikun , Wang Yifan , Wang Na , Wang Haodong , Liu Jingxi , Liu Yan
Published: May 2022

This paper presents a comprehensive framework for the reliability analysis of ship local structures. Existing reliability analysis of ship local structures relies on empirical analysis without experimental validation. The presented framework improves the probabilistic simulation process by combining finite element analysis and the Kriging surrogate model to increase the computational efficiency in uncertainty quantification. In addition, ultimate strength test data are introduced to update the prior distribution based on Bayesian data fusion. A cross-deck structure of a ship is studied in detail to present the application of this work. The framework provides a valuable reference for the reliability analysis of ship local structures and promotes the development of reliability-based design code. The novelty of this paper is that it introduces the combination of testing and probabilistic simulation into the reliability analysis of ship local structures.