bluuebunny/crossref_metadata_2025 huggingface dataset:
miR-16-5p Suppression Protects Human Cardiomyocytes against Endoplasmic Reticulum and Oxidative Stress-Induced Injury
Authors: Toro Rocío , Pérez-Serra Alexandra , Mangas Alipio , Campuzano Oscar , Sarquella-Brugada Georgia , Quezada-Feijoo Maribel , Ramos Mónica , Alcalá Martin , Carrera Esther , García-Padilla Carlos , Franco Diego , Bonet Fernando
Published: January 2022

Oxidative stress, defined as the excess production of reactive oxygen species (ROS) relative to antioxidant defense, plays a significant role in the development of cardiovascular diseases. Endoplasmic reticulum (ER) stress has emerged as an important source of ROS and its modulation could be cardioprotective. Previously, we demonstrated that miR-16-5p is enriched in the plasma of ischemic dilated cardiomyopathy (ICM) patients and promotes ER stress-induced apoptosis in cardiomyocytes in vitro. Here, we hypothesize that miR-16-5p might contribute to oxidative stress through ER stress induction and that targeting miR-16-5p may exert a cardioprotective role in ER stress-mediated cardiac injury. Analysis of oxidative markers in the plasma of ICM patients demonstrates that oxidative stress is associated with ICM. Moreover, we confirm that miR-16-5p overexpression promotes oxidative stress in AC16 cardiomyoblasts. We also find that, in response to tunicamycin-induced ER stress, miR-16-5p suppression decreases apoptosis, inflammation and cardiac damage via activating the ATF6-mediated cytoprotective pathway. Finally, ATF6 is identified as a direct target gene of miR-16-5p by dual-luciferase reporter assays. Our results indicate that miR-16-5p promotes ER stress and oxidative stress in cardiac cells through regulating ATF6, suggesting that the inhibition of miR-16-5p has potential as a therapeutic approach to protect the heart against ER and oxidative stress-induced injury.
Compatibility of Insecticides with Rice Resistance to Planthoppers as Influenced by the Timing and Frequency of Applications
Authors: Horgan Finbarr G. , Peñalver-Cruz Ainara
Published: January 2022

The brown planthopper, Nilaparvata lugens (Stål)(BPH) is a pest of rice in Asia. We examined the effects of seven insecticides combined with host resistance against BPH. In a screenhouse environment, we treated BPH-infested and non-infested resistant (IR62) and susceptible (IR64) rice with buprofezin, carbofuran, cartap hydrochloride, cypermethrin, deltamethrin, fipronil, or thiamethoxam + chlorantraniliprole. In one experiment, plants received one, two or three applications. In a second experiment, plants received one early or late insecticide application. Carbofuran and fipronil reduced planthopper biomass densities but resistance did not contribute to these effects (i.e., resistance was redundant). Single applications of cartap hydrochloride (at 20 or 50 days after sowing (DAS)), cypermethrin (20 DAS), or buprofezin (50 DAS) reduced BPH biomass densities on IR62 (i.e., synergies); other insecticides and application times, and multiple applications of all insecticides did not reduce BPH biomass densities on IR62 more than on IR64 (i.e., either resistance or insecticides were redundant). Deltamethrin (three applications) was antagonistic to resistance, but host resistance tended to buffer against the negative effects of single deltamethrin applications. Yields of infested IR62 were not statistically improved by insecticide applications. Late applications reduced yields of non-infested rice. We discuss how prophylactic insecticide applications could destabilize BPH populations and reduce the productivity and profitability of resistant rice.
The Identification and Validation of Hub Genes Associated with Acute Myocardial Infarction Using Weighted Gene Co-Expression Network Analysis
Authors: Xue Junqiang , Chen Lu , Cheng Hao , Song Xiaoyue , Shi Yuekai , Li Linnan , Xu Rende , Qin Qing , Ma Jianying , Ge Junbo
Published: January 2022

Acute myocardial infarction (AMI), one of the most severe and fatal cardiovascular diseases, remains the main cause of mortality and morbidity worldwide. The objective of this study is to investigate the potential biomarkers for AMI based on bioinformatics analysis. A total of 2102 differentially expressed genes (DEGs) were screened out from the data obtained from the gene expression omnibus (GEO) database. Weighted gene co-expression network analysis (WGCNA) explored the co-expression network of DEGs and determined the key module. The brown module was selected as the key one correlated with AMI. Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses demonstrated that genes in the brown module were mainly enriched in ‘ribosomal subunit’ and ‘Ribosome’. Gene Set Enrichment Analysis revealed that ‘TNFA_SIGNALING_VIA_NFKB’ was remarkably enriched in AMI. Based on the protein–protein interaction network, ribosomal protein L9 (RPL9) and ribosomal protein L26 (RPL26) were identified as the hub genes. Additionally, the polymerase chain reaction (PCR) results indicated that the expression levels of RPL9 and RPL26 were both downregulated in AMI patients compared with controls, in accordance with the bioinformatics analysis. In summary, the identified DEGs, modules, pathways, and hub genes provide clues and shed light on the potential molecular mechanisms of AMI.
Virtual Reality in the Preoperative Planning of Adult Aortic Surgery: A Feasibility Study
Authors: Abjigitova Djamila , Sadeghi Amir H. , Peek Jette J. , Bekkers Jos A. , Bogers Ad J. J. C. , Mahtab Edris A. F.
Published: January 2022

Background: Complex aortic anatomy needs careful preoperative planning in which a patient-tailored approach with novel immersive techniques could serve as a valuable addition to current preoperative imaging. This pilot study aimed to investigate the technical feasibility of virtual reality (VR) as an additional imaging tool for preoperative planning in ascending aortic surgery. Methods: Ten cardiothoracic surgeons were presented with six patients who had each undergone a recent repair of the ascending aorta. Two-dimensional computed tomography images of each patient were assessed prior to the VR session. After three-dimensional (3D) VR rendering and 3D segmentation of the ascending aorta and aortic arch, the reconstructions were analyzed by each surgeon in VR via a head-mounted display. Each cardiothoracic surgeon completed a questionnaire after each planning procedure. The results of their assessments were compared to the performed operations. The primary endpoint of the present study was a change of surgical approach from open to clamped distal anastomosis, and vice versa. Results: Compared with conventional imaging, 80% of surgeons found that VR prepared them better for surgery. In 33% of cases (two out of six), the preoperative decision was adjusted due to the 3D VR-based evaluation of the anatomy. Surgeons rated CardioVR usefulness, user-friendliness, and satisfaction with median scores of 3.8 (IQR: 3.5–4.1), 4.2 (IQR: 3.8–4.6,) and 4.1 (IQR: 3.8–4.7) on a five-point Likert scale, respectively. Conclusions: Three-dimensional VR imaging was associated with improved anatomical understanding among surgeons and could be helpful in the future preoperative planning of ascending aortic surgery.
Opioid Prescription Following Wrist and Ankle Fracture Fixation in Scotland—Tradition Prevails
Authors: Gardner William T. , MacDonald David R. W. , Kennedy Matthew J. , Faulkner Alastair C. , McIntyre Joshua R. , Forget Patrice , Aitken Stuart A. , Stevenson Iain M. ,   on behalf of the SCORE Collaborative
Published: January 2022

The American ‘opioid crisis’ is rapidly spreading internationally. Perioperative opioid use increases the risk of long-term opioid use. We review opioid use following wrist and ankle fracture fixation across Scotland, establishing prescribing patterns and associations with patient, injury, or perioperative factors. Six Scottish orthopedic units contributed. A total of 598 patients were included. Patient demographics were similar across all sites. There was variation in anesthetic practice, length of stay, and AO fracture type (p < 0.01). For wrist fractures, 85.6% of patients received a discharge opioid prescription; 5.0% contained a strong opioid. There was no significant variation across the six units in prescribing practice. For ankle fractures, 82.7% of patients received a discharge opioid prescription; 17% contained a strong opioid. Dundee and Edinburgh used more strong opioids; Inverness and Paisley gave the least opioids overall (p < 0.01). Younger patient age, location, and length of stay were independent predictors of increased prescription on binary regression. Despite variability in perioperative practices, discharge opioid analgesic prescription remains overwhelmingly consistent. We believe that the biggest influence lies with the prescriber-institutional ‘standard practice’. Education of these prescribing clinicians regarding the risk profile of opioids is key to reducing their use following surgery, thus lowering long-term opioid dependence.
XR (Extended Reality: Virtual Reality, Augmented Reality, Mixed Reality) Technology in Spine Medicine: Status Quo and Quo Vadis
Authors: Morimoto Tadatsugu , Kobayashi Takaomi , Hirata Hirohito , Otani Koji , Sugimoto Maki , Tsukamoto Masatsugu , Yoshihara Tomohito , Ueno Masaya , Mawatari Masaaki
Published: January 2022

In recent years, with the rapid advancement and consumerization of virtual reality, augmented reality, mixed reality, and extended reality (XR) technology, the use of XR technology in spine medicine has also become increasingly popular. The rising use of XR technology in spine medicine has also been accelerated by the recent wave of digital transformation (i.e., case-specific three-dimensional medical images and holograms, wearable sensors, video cameras, fifth generation, artificial intelligence, and head-mounted displays), and further accelerated by the COVID-19 pandemic and the increase in minimally invasive spine surgery. The COVID-19 pandemic has a negative impact on society, but positive impacts can also be expected, including the continued spread and adoption of telemedicine services (i.e., tele-education, tele-surgery, tele-rehabilitation) that promote digital transformation. The purpose of this narrative review is to describe the accelerators of XR (VR, AR, MR) technology in spine medicine and then to provide a comprehensive review of the use of XR technology in spine medicine, including surgery, consultation, education, and rehabilitation, as well as to identify its limitations and future perspectives (status quo and quo vadis).
The Impact of the COVID-19 Outbreak on Patients’ Adherence to PCSK9 Inhibitors Therapy
Authors: Caso Valentina Maria , Sperlongano Simona , Liccardo Biagio , Romeo Emanuele , Padula Sergio , Arenga Fortunato , D’Andrea Antonello , Caso Pio , Golino Paolo , Nigro Gerardo , Russo Vincenzo
Published: January 2022

PCSK9 inhibitors (PCSK9i) are monoclonal antibodies that have been shown to be effective in reducing both LDL cholesterol (LDL-C) values and major cardiovascular events in patients at high cardiovascular risk. Adherence to PCSK9i is critical for the success of the treatment. The aim of the present study is to evaluate patients’ adherence to PCSK9i during the COVID-19 pandemic. Patients referred to the Cardiac Diagnostic Unit of the University of Campania “Luigi Vanvitelli” Naples, taking PCSK9i, and who missed the cardiological follow-up visit during the first national COVID-19 lockdown (9 March–17 May 2020), were included. Each patient underwent medical teleconsultation to collect current clinical conditions, adherence to drug treatments, and lipid profile laboratory tests. Among 151 eligible patients, 20 were excluded for missing or untraceable telephone numbers and one for refusing to join the interview. The selected study population consisted of 130 patients (64 ± 9 years, 68% males), of whom 11 (8.5%) reported a temporary interruption of the PCSK-9 therapy for a mean period of 65 ± 1.5 days. The non-adherent patients showed a marked increase in LDL-C than in the pre-pandemic period (90.8 ± 6.0 vs. 54.4 ± 7.7 mg/dL, p < 0.0001), and 82% of patients moved out of the LDL-C therapeutic range. The non-adherent group was more likely to have a very high cardiovascular risk compared to the adherent group (81.8 vs. 33.6%, p < 0.001). Causes of interruption included drug prescription failure (63.6%) due to temporary interruption of the non-urgent outpatient visits and failure in drug withdrawal (36.4%) due to patients’ fear of becoming infected during the pandemic. The COVID-19 lockdown caused a remarkable lack of adherence to PCSK9i therapy, risking negative implications for the health status of patients at high cardiovascular risk. Facilitating patients’ access to PCSK9i and enhancing telemedicine seem to be effective strategies to ensure the continuity of care and appropriate management of these patients.
Accuracy of Machine Learning Assisted Detection of Keratoconus: A Systematic Review and Meta-Analysis
Authors: Cao Ke , Verspoor Karin , Sahebjada Srujana , Baird Paul N.
Published: January 2022

(1) Background: The objective of this review was to synthesize available data on the use of machine learning to evaluate its accuracy (as determined by pooled sensitivity and specificity) in detecting keratoconus (KC), and measure reporting completeness of machine learning models in KC based on TRIPOD (the transparent reporting of multivariable prediction models for individual prognosis or diagnosis) statement. (2) Methods: Two independent reviewers searched the electronic databases for all potential articles on machine learning and KC published prior to 2021. The TRIPOD 29-item checklist was used to evaluate the adherence to reporting guidelines of the studies, and the adherence rate to each item was computed. We conducted a meta-analysis to determine the pooled sensitivity and specificity of machine learning models for detecting KC. (3) Results: Thirty-five studies were included in this review. Thirty studies evaluated machine learning models for detecting KC eyes from controls and 14 studies evaluated machine learning models for detecting early KC eyes from controls. The pooled sensitivity for detecting KC was 0.970 (95% CI 0.949–0.982), with a pooled specificity of 0.985 (95% CI 0.971–0.993), whereas the pooled sensitivity of detecting early KC was 0.882 (95% CI 0.822–0.923), with a pooled specificity of 0.947 (95% CI 0.914–0.967). Between 3% and 48% of TRIPOD items were adhered to in studies, and the average (median) adherence rate for a single TRIPOD item was 23% across all studies. (4) Conclusions: Application of machine learning model has the potential to make the diagnosis and monitoring of KC more efficient, resulting in reduced vision loss to the patients. This review provides current information on the machine learning models that have been developed for detecting KC and early KC. Presently, the machine learning models performed poorly in identifying early KC from control eyes and many of these research studies did not follow established reporting standards, thus resulting in the failure of these clinical translation of these machine learning models. We present possible approaches for future studies for improvement in studies related to both KC and early KC models to more efficiently and widely utilize machine learning models for diagnostic process.
COVID-19 Severity and Cardiovascular Disease: An Inseparable Link
Authors: Henein Michael Y. , Cameli Matteo , Pastore Maria Concetta , Mandoli Giulia Elena
Published: January 2022

The COVID-19 pandemic is a global health issue that has so far affected over 250 million people worldwide [...]
Anatabine, Nornicotine, and Anabasine Reduce Weight Gain and Body Fat through Decreases in Food Intake and Increases in Physical Activity
Authors: Grebenstein Patricia E. , Erickson Paige , Grace Martha , Kotz Catherine M.
Published: January 2022

Obesity is a leading cause of preventable death in the United States. Currently approved pharmacotherapies for the treatment of obesity are associated with rebound weight gain, negative side effects, and the potential for abuse. There is a need for new treatments with fewer side effects. Minor tobacco alkaloids (MTAs) are potential candidates for novel obesity pharmacotherapies. These alkaloids are structurally related to nicotine, which can help reduce body weight, but without the same addictive potential. The purpose of the current study was to examine the effects of three MTAs (nornicotine, anatabine, and anabasine) and nicotine on weight gain, body composition, chow intake, and physical activity. We hypothesized that the MTAs and nicotine would reduce weight gain through reductions in chow intake and increases in physical activity. To test this, male Sprague Dawley rats were housed in metabolic phenotyping chambers. Following acclimation to these chambers and to (subcutaneous (sc)) injections of saline, animals received daily injections (sc) of nornicotine, anabasine, anatabine, or nicotine for one week. Compared to saline-injected animals that gained body weight and body fat during the treatment phase, injections of nornicotine and anatabine prevented additional weight gain, alongside reductions in body fat. Rats receiving anabasine and nicotine gained body weight at a slower rate relative to rats receiving saline injections, and body fat remained unchanged. All compounds reduced the intake of chow pellets. Nornicotine and nicotine produced consistent increases in physical activity 6 h post-injection, whereas anabasine’s and anatabine’s effects on physical activity were more transient. These results show that short-term, daily administration of nornicotine, anabasine, and anatabine has positive effects on weight loss, through reductions in body fat and food intake and increases in physical activity. Together, these findings suggest that MTAs are worthy of further investigations as anti-obesity pharmacotherapies.
Pneumonia in Acute Ischemic Stroke Patients with Proximal Occlusions within the Anterior Circulation after Endovascular Therapy or Systemic Thrombolysis
Authors: Muhl Henning , Roth Christian , Schröter Andreas , Politi Maria , Alexandrou Maria , Dahl Janina , Gindorf Susanne , Papanagiotou Panagiotis , Kastrup Andreas
Published: January 2022

While endovascular treatment (ET) improves clinical outcomes in patients with proximal vessel occlusions compared to thrombolysis (IVT), the impact of ET on the frequency of stroke-associated pneumonia (SAP) is uncertain. We compared the rates of SAP in patients with large vessel occlusions in the anterior circulation after IVT or ET. We also determined risk factors for SAP, as well as the impact of SAP on early clinical outcomes. A total of 544 patients were treated with IVT, and 1061 patients received ET (with or without IVT). The rates of SAP did not differ significantly between ET (217/1061; 20%) and IVT (100/544; 18%) (p = 0.3). Overall, the occurrence of SAP was significantly associated with mortality and a poor clinical outcome. In the multivariable regression analysis, age, sex, the presence of dysphagia, early signs of ischemia on imaging and a history of stroke and mechanical ventilation were all significantly associated with the occurrence of SAP. In patients with large vessel occlusions, the introduction of ET did not result in lower rates of SAP compared with IVT. There is an ongoing need to reduce the rates of SAP in this patient population, for which the risk factors found here could become useful.
Anemochore Seeds Harbor Distinct Fungal and Bacterial Abundance, Composition, and Functional Profiles
Authors: Liu Dong , Cai Jie , He Huajie , Yang Shimei , Chater Caspar C. C. , Yu Fuqiang
Published: January 2022

Many plants adapted to harsh environments have evolved low seed mass (‘light seeds’) with specific dispersal strategies, primarily either by wind (anemochory) or water (hydrochory). However, the role of their seed microbiota in their survival, and their seed microbial abundance and structure, remain insufficiently studied. Herein, we studied the light seed microbiome of eight anemochores and two hydrochores (as controls) collected from four provinces in China, using qPCR and metagenomic sequencing targeting both bacteria and fungi. Substantial variations were found for seed endophytic fungi (9.9 × 1010~7.3 × 102 gene copy numbers per seed) and bacteria (1.7 × 1010~8.0 × 106). Seed microbial diversity and structure were mainly driven by the plant genotype (species), with weak influences from their host plant classification level or dispersal mode. Seed microbial composition differences were clear at the microbial phylum level, with dominant proportions (~75%) for Proteobacteria and Ascomycota. The light seeds studied harbored unique microbial signatures, sharing only two Halomonas amplicon sequence variants (ASVs) and two fungal ASVs affiliated to Alternaria and Cladosporium. A genome-level functional profile analysis revealed that seed bacterial microbiota were enriched in amino acid, nucleoside, and nucleotide biosynthesis, while in fungal communities the generation of precursor metabolites and respiration were more highly represented. Together, these novel insights provide a deeper understanding of highly diversified plant-specific light seed microbiota and ecological strategies for plants in harsh environments.
The Determinants of the 13-Year Risk of Incident Atrial Fibrillation in a Russian Population Cohort of Middle and Elderly Age
Authors: Shapkina Marina , Ryabikov Andrey , Mazdorova Ekaterina , Titarenko Anastasia , Avdeeva Ekaterina , Mazurenko Elena , Shcherbakova Lilia , Pikhart Hynek , Bobak Martin , Malyutina Sofia
Published: January 2022

Atrial fibrillation (AF) is the most common arrhythmia and a predictor of the complications of atherosclerotic cardiovascular diseases (ASCVDs), particularly thromboembolic events and the progression of heart failure. We analyzed the determinants of the 13-year risk of incident AF in a Russian population cohort of middle and elderly age. A random population sample (n = 9360, age 45–69 years) was examined at baseline in 2003–2005 and reexamined in 2006–2008 and 2015–2017 in Novosibirsk (the HAPIEE study). Incident AF was being registered during the average follow-up of 13 years. The final analysis included 3871 participants free from baseline AF and cardiovascular disease (CVD) who participated in all three data collections. In a multivariable-adjusted Cox regression model, the 13-year risk of AF was positively associated with the male sex (hazard ratio (HR) = 2.20; 95% confidence interval (CI) 1.26–3.87); age (HR = 1.10 per year; 95% CI 1.07–1.14); body mass index (BMI), (HR = 1.11 per unit; 95% CI 1.07–1.15); systolic blood pressure (SBP), (HR = 1.02 per 1 mmHg; 95% CI 1.01–1.02), and it was negatively associated with total cholesterol (TC), (HR = 0.79 per 1 mmol/L; 95% CI 0.66–0.94). In women, the risk of AF was more strongly associated with hypertension (HT) and was also negatively related to total cholesterol (TC) level (HR = 0.74 per 1 mmol/L; 95% CI 0.56–0.96). No independent association was found with mean alcohol intake per drinking occasion. These results in a Russian cohort have an implication for the prediction of AF and ASCVD complications in the general population.
What Problem Is Post-Crisis QE Trying to Solve?
Authors: Atkinson Paul , Blundell-Wignall Adrian
Published: January 2022

What problem the Fed and other central banks are solving by printing money and letting interest rates fall to zero is the focus of this paper. This activity does not appear to affect nominal GDP or inflation prior to COVID, and yet central bank liabilities have continued to rise. This suggests the presence of rising cash demand that has prevented excess cash and inflation pressures from emerging. While there was some hope that quantitative easing would be a new instrument in addition to interest rates as far as monetary policy goals were concerned, this has not proved to be the case. Instead, banking system demand for central bank liabilities keeps rising as an endogenous response to the changed business models of banks forced on them by post-crisis re-regulation and extremely low interest rates. These ideas were tested with cointegration and error correction econometric techniques. Examples of the growing risk of leverage and counterparty risks in this disequilibrium process are provided.
African Forest-Fringe Farmers Benefit from Modern Farming Practices despite High Environmental Impacts
Authors: Acheampong Emmanuel Opoku , Sloan Sean , Sayer Jeffrey , Macgregor Colin J.
Published: January 2022

Agricultural expansion has led to a significant loss of habitat and biodiversity in Ghana and throughout West Africa and the tropics generally. Most farmers adopt both organic and inorganic inputs to boost production, with the potential to slow agricultural expansion, but with relatively little consideration of related environmental impacts. In Ghana, where high-input modern farming is rapidly overtaking traditional organic agricultural practices, we examined five stakeholder groups in regard to their perceptions of the environmental, economic, and social costs and benefits of modern, mixed-input, and traditional farming systems. The stakeholder groups included farmers adopting different agricultural practices, as well as governmental and non-governmental natural resource managers. Our findings indicate that the overall perceived costs of modern farming, attributable to large quantities of inorganic inputs, are higher than the overall perceived benefits. Farmers are, however, still motivated to practice modern farming because of perceived higher returns on investment, regardless of environmental impacts, which they tend to discount. Traditional farmers do not use inorganic inputs and instead rely on swidden ‘slash-and-burn’ practices, resulting in declining productivity and soil fertility over time. Since traditional farmers are ultimately forced to encroach into nearby forests to maintain productivity, the perceived environmental sustainability of such farming systems is also limited. Mixed-input farming is not significantly different from modern farming with respect to its perceived environmental and economic traits, because it incorporates agro-chemicals alongside organic practices. Stakeholders’ perceptions and the apparent environmental outcomes of different farming systems suggest that reducing the use of inorganic inputs and promoting the adoption of organic inputs could minimise the negative impacts of agro-chemicals on the forest environment without necessarily compromising productivity. Campaigns to promote low-input or organic agriculture on environmental grounds in West Africa may falter if they fail to recognise farmers’ relatively favourable perceptions of the environmental implications of modern farming practices.
Evaluation of Public Service Facilities in 19 Large Cities in China from the Perspective of Supply and Demand
Authors: Wei Wei , Ren Xiwen , Guo Shiyi
Published: January 2022

The equalization of urban public service facilities is important to the daily lives of urban residents. Spatial quantification of the supply and demand of public service facilities can reveal relationships between supply and demand agents and provide a foundation for the planning of urban public service facilities. This study proposed a comprehensive framework to assess the current state of supply (accessibility of facilities) and demand (population carrying pressure) of various public services in cities and determine patterns between different public service facilities. This framework contains three elements: (a) multi-scale spatial quantification of the matching of supply and demand, (b) spatial matching of supply and demand, and (c) spatial clustering analysis of the supply and demand balance. This study analyzed 19 major cities in China from a supply and demand perspective and examined implications for matching the supply and demand of public service facilities. The results indicated that education service facilities had the most appropriate supply and demand relationship. Areas where public service facilities had a good matching of supply and demand demonstrated a strong pattern of clustering. There were significant differences in the level of matching of the supply and demand of public service facilities among various regions in China. The limitations of the framework and future directions are discussed.
(±)-2-(2-Fluoro-[1,1′-biphenyl]-4-yl)-N-(1-phenylpropan-2-yl)propanamide
Authors: Manolov Stanimir , Ivanov Iliyan , Bojilov Dimitar
Published: January 2022

2-(2-fluoro-[1,1′-biphenyl]-4-yl)-N-(1-phenylpropan-2-yl)propanamide was synthesized by a reaction between amphetamine and flurbiprofen in high yields. The newly obtained hybrid molecule was fully analyzed and characterized via 1H, 13C, UV, IR, HPLC, and mass spectral data.
Study on Oxygen Evolution Reaction Performance of Jarosite/C Composites
Authors: Chen Junxue , Li Sijia , Qu Zizheng , Li Zhonglin , Wang Ding , Shen Jialong , Li Yibing
Published: January 2022

In the electrolysis of water process, hydrogen is produced and the anodic oxygen evolution reaction (OER) dominates the reaction rate of the entire process. Currently, OER catalysts mostly consist of noble metal (NM) catalysts, which cannot be applied in industries due to the high price. It is of great importance to developing low-cost catalysts materials as NM materials substitution. In this work, jarosite (AFe3(SO4)2(OH)6, A = K+, Na+, NH4+, H3O+) was synthesized by a one-step method, and its OER catalytic performance was studied using catalytic slurry (the weight ratios of jarosite and conductive carbon black are 2:1, 1:1 and 1:2). Microstructures and functional groups of synthesized material were analyzed using XRD, SEM, FI-IR, etc. The OER catalytic performance of (NH4)Fe3(SO4)2(OH)6/conductive carbon black were examined by LSV, Tafel, EIS, ECSA, etc. The study found that the OER has the best catalytic performance when the weight ratio of (NH4)Fe3(SO4)2(OH)6 to conductive carbon black is 2:1. It requires only 376 mV overpotential to generate current densities of 10 mA cm−2 with a small Tafel slope (82.42 mV dec−1) and large Cdl value (26.17 mF cm−2).
Prospective Clinical Evaluation of Posterior Third-Generation Monolithic Zirconia Crowns Fabricated with Complete Digital Workflow: Two-Year Follow-Up
Authors: Gseibat Mustafa , Sevilla Pablo , Lopez-Suarez Carlos , Rodríguez Verónica , Peláez Jesús , Suárez María J.
Published: January 2022

Clinical studies on the behavior of posterior translucent monolithic zirconia restorations are lacking. We assessed the clinical outcome and survival rate of posterior third-generation monolithic zirconia crowns over a 2-year period. A total of 24 patients, requiring 30 posterior full-contour restorations were selected. All abutments were scanned, and crowns were milled and cemented with a self-adhesive dual cure cement. Crowns were assessed using the California Dental Association’s criteria. Gingival status was assessed by evaluating the gingival index, plaque index, periodontal probing depth of the abutments and control teeth, and the margin index of the abutment teeth. Statistical analyses were performed using the Friedman and the Wilcoxon signed-rank tests. During the 2-year follow-up, no biological or mechanical complications were observed, and the survival and success rate was 100%. All restorations ranked as satisfactory throughout the follow-up period. The gingival index and plaque index were worse at the end of the 2-year follow-up. The margin index was stable during the 2 years of clinical service. No significant differences were recorded in periodontal parameters between crowns and control teeth. Third-generation monolithic zirconia could be a reliable alternative to posterior metal–ceramic and second-generation monolithic zirconia posterior crowns.
Properties of Old Concrete Built in the Former Leipziger Palace
Authors: Ambroziak Andrzej , Haustein Elżbieta
Published: January 2022

This research aims to determine the mechanical, chemical, and physical properties of old concrete used in the former Leipziger Palace in Wrocław, Poland. The cylindrical specimens were taken from the basement concrete walls using a concrete core borehole diamond drill machine. The determination of the durability and strength of old concrete was based on specified chosen properties of the old concrete obtained through the following set of tests: measurements of dry density, tests of water absorption, specification of concrete compressive strength and frost resistance, determination of the modulus of elasticity, measurement of the pH value, determination of water-soluble chloride salts and sulphate ions, and X-ray diffraction analyses. Large dispersions of the compressive strength (10.4 MPa to 34.2 MPa), density (2049 kg/m3 to 2205 kg/m3), water absorption (4.72% to 6.55%), and stabilized secant modulus of elasticity (15.25 Gpa to 19.96 GPa) were observed. The paper is intended to provide scientists, civil engineers, and designers with guidelines for examining and assessing the long-term durability of old concrete, and also extending knowledge in the field of archaeological restoration and the protection of old concrete structures.
Morphology Design and Fabrication of Bio-Inspired Nano-MgO–Mg(OH)2 via Vapor Steaming to Enable Bulk CO2 Diffusion and Capture
Authors: Senevirathna Hasanthi L. , Wu Shunnian , Lee W. P. Cathie , Wu Ping
Published: January 2022

The absorption of CO2 on MgO is being studied in depth in order to enhance carbon engineering. Production of carbonate on MgO surfaces, such as MgCO3, for example, has been shown to hinder further carbon lattice transit and lower CO2 collecting efficiency. To avoid the carbonate blocking effect, we mimic the water harvesting nano-surface systems of desert beetles, which use alternate hydrophobic and hydrophilic surface domains to collect liquid water and convey condensed droplets down to their mouths, respectively. We made CO2-philic MgO and CO2-phobic Mg(OH)2 nanocomposites from electrospun nano-MgO by vapor steaming for 2–20 min at 100 °C. The crystal structure, morphology, and surface properties of the produced samples were instrumentally characterized using XRD, SEM, XPS, BET, and TGA. We observed that (1) fiber morphology shifted from hierarchical particle and sheet-like structures to flower-like structures, and (2) CO2 capture capacity shifted by around 25%. As a result, the carbonate production and breakdown processes may be managed and improved using vapor steaming technology. These findings point to a new CO2 absorption technique and technology that might pave the way for more CO2 capture, mineralization, and fuel synthesis options.
Recovery of Waste Materials: Technological Research and Industrial Scale-Up
Authors: Medici Franco
Published: January 2022

An increase in population, booming economy, rapid urbanization and the rise in living standards have exponentially accelerated waste production [...]
Anion Recognition by a Pincer-Type Host Constructed from Two Polyamide Macrocyclic Frameworks Jointed by a Photo-Addressable Azobenzene Switch
Authors: Niedbała Patryk , Ceborska Magdalena , Mehmet Mart , Ignacak Wiktor , Jurczak Janusz , Dąbrowa Kajetan
Published: January 2022

A sterically crowded light-responsive host 1 was synthetized with a 93% yield by applying a post-functionalization protocol utilizing the double amidation of 4,4′-azodibenzoyl dichloride with a readily available 26-membered macrocyclic amine. X-ray structures of two hydrates of trans-1 demonstrate a very different alignment of the azobenzene linkage, which is involved in T-shape or parallel-displaced π⋯π stacking interactions with the pyridine-2,6-dicarboxamide moieties from the macrocyclic backbone. Despite the rigidity of the macrocyclic framework, which generates a large steric hindrance around the azobenzene chromophore, the host 1 retains the ability to undergo a reversible cis⟷trans isomerization upon irradiation with UVA (368 nm) and blue (410 nm) light. Moreover, thermal cis→trans back-isomerization (ΔG0 = 106.5 kJ∙mol−1, t½ = 141 h) is markedly slowed down as compared to the non-macrocyclic analog. 1H NMR titration experiments in DMSO-d6/0.5% water solution reveal that trans-1 exhibits a strong preference for dihydrogenphosphate (H2PO4−) over other anions (Cl−, MeCO2−, and PhCO2−), whereas the photogenerated metastable cis-1 shows lower affinity for the H2PO4− anion.
Properties of Blended Cement Containing Iron Tailing Powder at Different Curing Temperatures
Authors: Wang Heng , Han Fanghui , Pu Shaochang , Zhang Hongbo
Published: January 2022

The properties of blended cement containing 0%, 20%, and 50% iron tailing powder (ITP) at 20 °C and 60 °C were investigated by determining the hydration heat, microstructure, and compressive strength. The addition of ITP decreases the exothermic rate and cumulative hydration heat of blended cement at 20 °C. The high temperature increases the hydration rate and leads to the hydration heat of blended cement containing 20% ITP higher than that of Portland cement. Increasing the amount of ITP decreases the non-evaporable water content and Ca(OH)2 content as well as compressive strength at both of the two studied temperatures. The addition of ITP coarsens the early-age pore structure but improves the later-age pore structure at 20 °C. The high temperature significantly improves the early-age properties of blended cement containing ITP, but it is detrimental to the later-age properties development. The reaction of ITP is limited even at high temperature. The large ITP particles bond poorly with surrounding hydration products under early high-temperature curing condition. The properties of blended cement containing a large amount of ITP are much poorer at high temperature.
Preparation of Allyl Alcohol Oligomers Using Dipicolinate Oxovanadium(IV) Coordination Compound
Authors: Pobłocki Kacper , Jacewicz Dagmara , Walczak Juliusz , Gawdzik Barbara , Kramkowski Karol , Drzeżdżon Joanna , Kowalczyk Paweł
Published: January 2022

Currently, new precatalysts for olefin oligomerization are being sought in the group of vanadium(IV) complexes. Thus, the aim of our research was to examine the catalytic activity of the oxovanadium(IV) dipicolinate complex [VO(dipic)(H2O)2] 2 H2O (dipic = pyridine-2,6-dicarboxylate anion) in 2-propen-1-ol oligomerization as well as to characterize oligomerization products using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry (MALDI-TOF-MS), infrared spectroscopy (IR) and nuclear magnetic resonance (NMR). The oligomerization process took place at room temperature, under atmospheric pressure and under nitrogen atmosphere to prevent oxidation of the activator MMAO-12—the modified methylaluminoxane (7 wt.%) aluminum in toluene. The last point was to determine the catalytic activity of the complex in the oligomerization reaction of 2-propen-1-ol. The aspect that enriches this work is the proposed mechanism of oligomerization of allyl alcohol based on the literature.
Diffusion Bonding of Al-Mg-Si Alloy and 301L Stainless Steel by Friction Stir Lap Welding Using a Zn Interlayer
Authors: Dong Ji-Hong , Liu Hua , Ji Shu-De , Yan De-Jun , Zhao Hua-Xia
Published: January 2022

Friction stir lap welding (FSLW) is expected to join the hybrid structure of aluminum alloy and steel. In this study, the Al-Mg-Si aluminum alloy and 301L stainless steel were diffusion bonded by FSLDW with the addition of 0.1 mm thick pure Zn interlayer, when the tool pin did not penetrate the upper aluminum sheet. The characteristics of lap interface and mechanical properties of the joint were analyzed. Under the addition of Zn interlayer, the diffusion layer structure at lap interface changed from continuous to uneven and segmented. The components of the diffusion layer were more complex, including Fe-Al intermetallic compounds (IMCs), Fe-Zn IMCs and Al-Zn eutectic. The largely changed composition and thickness of uneven and segmented diffusion layer at the lap interface played a significant role in the joint strength. The tensile shear load of Zn-added joint was 6.26 kN, increasing by 41.3% than that of Zn-not-added joint. These two joints exhibited interfacial shear fracture, while the Zn interlayer enhanced the strength of diffusion bonding by extending the propagation path of cracks.
Natural Frequencies Optimization of Thin-Walled Circular Cylindrical Shells Using Axially Functionally Graded Materials
Authors: Alshabatat Nabeel Taiseer
Published: January 2022

One method to avoid vibration resonance is shifting natural frequencies far away from excitation frequencies. This study investigates optimizing the natural frequencies of circular cylindrical shells using axially functionally graded materials. The constituents of functionally graded materials (FGMs) vary continuously in the longitudinal direction based on a trigonometric law or using interpolation of volume fractions at control points. The spatial change of material properties alters structural stiffness and mass, which then affects the structure’s natural frequencies. The local material properties at any place in the structure are obtained using Voigt model. First-order shear deformation theory and finite element method are used for estimating natural frequencies, and a genetic algorithm is used for optimizing material volume fractions. To demonstrate the proposed method, two optimization problems are presented. The goal of the first one is to maximize the fundamental frequency of an FGM cylindrical shell by optimizing the material volume fractions. In the second problem, we attempt to find the optimal material distribution that maximizes the distance between two adjoining natural frequencies. The optimization examples show that building cylindrical shells using axially FGM is a useful technique for optimizing their natural frequencies.
Investigation of the Effects of Tool Positioning Factors on Peak Temperature in Dissimilar Friction Stir Welding of AA6061-T6 and AA7075-T6 Aluminum Alloys
Authors: Ghiasvand Amir , Suksatan Wanich , Tomków Jacek , Rogalski Grzegorz , Derazkola Hesamoddin Aghajani
Published: January 2022

Among the emerging new welding techniques, friction stir welding (FSW) is used frequently for welding high-strength aluminum alloys that are difficult to weld by conventional fusion-welding techniques. This paper investigated the effects of tool-positioning factors on the maximum temperature generated in the dissimilar FSW joint of AA6061-T6 and AA7075-T6 aluminum alloys. Three factors of plunge depth, tool offset, and tilt angle were used as the input parameters. Numerical simulation of the FSW process was performed in ABAQUS software using the coupled Eulerian–Lagrangian (CEL) approach. Central composite design (CCD) based on response surface methodology (RSM) was used to analyze and design the experiments. Comparison of the numerical and experimental results showed that numerical simulations were in good agreement with the experimental ones. Based on the statistical model results, plunge depth, tilt angle, and tool offset were the most significant factors on maximum process temperature, respectively. It was found that increasing the plunge depth caused a sharp increase in the maximum process temperature due to increased contact surfaces and the frictional interaction between the tool and workpiece.
Image-Based vs. Parametric Modelling of Concrete Meso-Structures
Authors: Wang Jiaming , Jivkov Andrey P. , Engelberg Dirk L. , Li Qingming
Published: January 2022

Damage initiation and crack propagation in concrete are associated with localisation of energy dissipation by the concrete meso-structure. Meso-scale models are, therefore, required for realistic analysis of concrete non-linear behaviour. Such models are constructed either from X-ray Computed Tomography images (image-based modelling) or by in silico meso-structure generation (parametric modelling), while both approaches are widely used and their advantages and disadvantages are recognised, little work is done on comparing their performance in predicting measured macroscopic behaviour with equivalent constitutive relations for meso-structural features. This work uses microstructure characterisation and mechanical behaviour data to construct, validate and compare the two modelling approaches. The macroscopic behaviour obtained with both meso-structural models is found to be in good agreement with experimental data. Differences are observed only between the predicted distributions of damage within specimens. These outcomes suggest that the computationally simpler parametric meso-structures are sufficient to derive stress–strain behaviour for engineering-scale models in the absence of other environmental factors. The observed differences in damage distribution could be important for analysis of coupled behaviour, e.g., mass transport and chemical reactions affecting local mechanical properties and being affected by local damage. Establishing the importance of damage distribution is such cases requires further research.
A Calculation Method for Tooth Wear Depth Based on the Finite Element Method That Considers the Dynamic Mesh Force
Authors: He Zao , Hu Yumei , Zheng Xingyuan , Yu Yuanyuan
Published: January 2022

Gear wear is a progressive material removal process that gradually changes the tooth profile shape and dynamic mesh force, where the dynamic mesh force affects the tooth surface wear. To describe this process, a spur gear dynamic model that includes the mesh stiffness and unloaded static transmission error (STE) of the worn tooth profile is proposed for calculating the dynamic mesh force. Then, based on the finite element method (FEM), a dynamic contact analysis model that considers the dynamic mesh force is proposed for calculating the time-varying contact stress and relative sliding distance of the tooth surface mesh point. Finally, combined with the Archard wear model, a tooth wear depth calculation method that considers the worn tooth profile and the dynamic mesh force is proposed. In addition, the wear depth and dynamic characteristics under different wear times are studied.
Event-Triggered Impulsive Optimal Control for Continuous-Time Dynamic Systems with Input Time-Delay
Authors: Bai Quanyu , Zhu Wei
Published: January 2022

Time-delay is an inevitable factor in practice, which may affect the performance of optimal control. In this paper, the event-triggered impulsive optimal control for linear continuous-time dynamic systems is studied. The event-triggered impulsive optimal feedback controller with input time-delay is presented, where the impulsive instants are determined by some designed event-triggering function and condition depending on the state of the system. Some sufficient conditions are given for guaranteeing the exponential stability with the optimal controller. Moreover, the Zeno-behavior for the impulsive instants is excluded. Finally, an example with numerical simulation is given to verify the validity of the theoretical results.
Equal Access to University Education in Chile? An Application Using Spatial Heckman Probit Models
Authors: Quiroz Juan Luis , Peeters Ludo , Chasco Coro , Aroca Patricio
Published: January 2022

This study contributes to the debate on accessibility of higher education in Chile, with a special focus on the geospatial dimension of access to university studies. This paper addresses the central question of whether geography (physical distance and neighborhood effects) plays a significant role in determining the accessibility of higher education to students in Chile. We use Heckman probit-type (Heckit) models to adjust for selection during application for higher education—that is, pre-selection among applications to study at university and, ultimately, admission (or denial) to a higher educational institution. Of all high school graduates who took the university selection test (PSU), only 37.9% were able to attend higher education. The results show that the geospatial elements—neighborhood characteristics and distance from the city of Santiago—have a significant local effect on the student’s application and access to Chilean universities. Specifically, the most significant local range for each candidate is 300 neighbors. We also find that, when distance to the capital city increases, the probability of applying to university increases to a threshold of 1400 km, at which point probability begins to decrease.