bluuebunny/crossref_metadata_2025 huggingface dataset:
The Effect of Trap Color on Catches of Monochamus galloprovincialis and Three Most Numerous Non-Target Insect Species
Authors: Sukovata Lidia , Dziuk Aleksander , Plewa Radosław , Jaworski Tomasz
Published: February 2022

Black pheromone-baited traps are commonly used for monitoring Monochamus galloprovincialis, a vector of Bursaphelenchus xylophilus, although few studies have been conducted on its response to color (black, white, and clear). The objective of our studies was to evaluate the attractiveness of different colors to M. galloprovincialis and non-target species: Spondylis buprestoides and predatory Thanasimus formicarius and T. femoralis. Laboratory tests of fifteen colors against immature and mature M. galloprovincialis revealed some differences in their color preference. In two field tests, eight colors of coroplast vanes in cross-vane traps were compared with unpainted white (a reference (RF)). The first test confirmed the laboratory results, i.e., RF was slightly more attractive to M. galloprovincialis than pastel yellow, reseda green, and cyan blue, but trap color had no significant effect on any of the insect species studied. In the second test, the attractiveness of RF was highest and significantly different from pure white (for all four species), light blue, and pine green (except S. buprestoides). Overall, the unpainted white traps appeared to be most effective in catching M. galloprovincialis. Thanasimus spp. responded to the colors similarly to M. galloprovincialis; therefore, either trap design or lure composition should be modified to reduce their catches.
Are the Dental Guidelines for Early Dental Visits and Fluoridation Measures Supported by Pediatricians, and What Are Their Caries Prevention Efforts?
Authors: Geiken Antje , Holtmann Louise , Splieth Christian H. , Conrad Jonas , Doerfer Christof E. , Graetz Christian
Published: February 2022

(1) Background: In Germany, new recommendations for dental examinations of children and the use of fluorides have been introduced. The pediatrician (PA) should refer the patient to the dentist for dental examinations and check-ups (DEs) from the sixth month of age. Therefore, our aim was to determine with a questionnaire the extent to which PAs find DE useful, make referrals for DE and recommend fluoride. (2) Methods: The nationwide empirical survey was conducted with a self-developed and validated standardized online questionnaire. In addition to personal information, 16 items were collected. Agreement with the items was recorded using Likert scales. The data were primarily analysed descriptively. (3) Results: 696 PAs participated in the survey (age: 51.7 (8.4) years, women/men: 428/286 (61.5/38.5%). A total of 11% of PAs found referral by eruption of first tooth very important (important/neutral/unimportant: 13.8/32/43.2%), compared to 70% for complete deciduous teeth (21.3/7.3/1.4%). A total of 48.8% of PAs always recommended fluoridated toothpaste from the first tooth (often/occasionally/rarely/never: 18.3/7.8/8/17.1%) and 50.6% completely refused to recommend fluoride-free toothpaste (always/often/occasionally/rarely: 9.8/9/14.7/15.9%). A total of 44.8% never recommended the use of fluoridated toothpaste if the child cannot yet spit (always/often/occasionally/rarely: 19.2/13.9/7.8/14.3%). (4) Conclusions: Among PAs, referral to DEs was increasingly implemented as children grew older. Specific fluoride recommendations were accepted.
Hemorrhagic Transformation in Acute Ischemic Stroke: A Quantitative Systematic Review
Authors: Honig Asaf , Percy Jennifer , Sepehry Amir A. , Gomez Alejandra G. , Field Thalia S. , Benavente Oscar R.
Published: February 2022

The prevalence and risk factors of hemorrhagic transformation (HT) after acute ischemic stroke HT have not been adequately delineated. We performed a systematic review and meta-analysis to identify English-language prospective observational MEDLINE and EMBASE-listed reports of acute ischemic stroke with HT published from 1985–2017. Studies that used the ECASS-2 definitions of hemorrhagic transformation subtypes, hemorrhagic infarction (HI), and parenchymal hematoma (PH) were included. Patients treated with intravenous thrombolysis with tissue plasminogen activator (IV-tPA) were compared with those who did not receive thrombolysis. A total of 65 studies with 17,259 patients met inclusion criteria. Overall, HT prevalence was 27%; 32% in patients receiving IV-tPA vs. 20% in those without. Overall PH prevalence was 9%; 12% in IV-tPA treated patients vs. 5% in those without. HT was associated with a history of atrial fibrillation (OR 2.94) and use of anticoagulants (OR 2.47). HT patients had higher NIHSS (Hedge’s-G 0.96) and larger infarct volume (diffusion-weighted MRI, Hedge’s-G 0.8). In IV-tPA treated patients, PH correlated with antiplatelet (OR 3) and statin treatment (OR 4). HT (OR 3) and PH (OR 8) were associated with a poor outcome at 90-day (mRS 5–6). Hemorrhagic transformation is a frequent complication of acute ischemic stroke and is associated with poor outcome. Recognition of risk factors for HT and PH may reduce their incidence and severity.
Cryoballoon Ablation for Persistent and Paroxysmal Atrial Fibrillation: Procedural Differences and Results from the Spanish Registry (RECABA)
Authors: Vallès Ermengol , Jiménez Jesús , Martí-Almor Julio , Toquero Jorge , Ormaetxe José Miguel , Barrera Alberto , García-Alberola Arcadio , Rubio José Manuel , Moriña Pablo , Grande Carlos , Fé Arcocha Maria , Peinado Rafael , Cózar Rocío , Hernández Julio , Pérez-Alvarez Luisa , Gaztañaga Larraitz , Ferrero-De Loma-Osorio Angel , Ruiz-Granell Ricardo , Villuendas Roger , Martínez-Alday Jesús Daniel
Published: February 2022

Introduction: Cryoballoon ablation (CBA) has become a standard treatment for paroxysmal atrial fibrillation (PaAF) but limited data is available for outcomes in patients with persistent atrial fibrillation (PeAF). Methods: We analyzed the first 944 patients included in the Spanish Prospective Multi-center Observation Post-market Registry to compare characteristics and outcomes of patients undergoing CBA for PeAF versus PaAF. Results: A total of 944 patients (57.8 ± 10.4 years; 70.1% male) with AF (27.9% persistent) were prospectively included from 25 centers. PeAF patients were more likely to have structural heart disease (67.7 vs. 11.4%; p < 0.001) and left atrium dilation (72.6 vs. 43.3%; p < 0.001). CBA of PeAF was less likely to be performed under general anesthesia (10.7 vs. 22.2%; p < 0.001), with an arterial line (32.2 vs. 44.6%; p < 0.001) and assisted transeptal puncture (11.9 vs. 17.9%; p = 0.025). During an application, PeAF patients had a longer time to −30 °C (35.91 ± 14.20 vs. 34.93 ± 12.87 s; p = 0.021) and a colder balloon nadir temperature during vein isolation (−35.04 ± 9.58 vs. −33.61 ± 10.32 °C; p = 0.004), but received fewer bonus freeze applications (30.7 vs. 41.1%; p < 0.001). There were no differences in acute pulmonary vein isolation and procedure-related complications. Overall, 76.7% of patients were free from AF recurrences at 15-month follow-up (78.9% in PaAF vs. 70.9% in PeAF; p = 0.09). Conclusions: Patients with PeAF have a more diseased substrate, and CBA procedures performed in such patients were more simplified, although longer/colder freeze applications were often applied. The acute efficacy/safety profile of CBA was similar between PaAF and PeAF patients, but long-term results were better in PaAF patients.
IGNITE Status Epilepticus Survey: A Nationwide Interrogation about the Current Management of Status Epilepticus in Germany
Authors: Kowoll Christina , Klein Matthias , Salih Farid , Fink Gereon , Stetefeld Henning , Onur Oezguer , Malter Michael ,   on behalf of the IGNITE Group
Published: February 2022

We aimed to evaluate the current management of status epilepticus (SE) in intensive care units (ICUs) in Germany, depending on the different hospital levels of care and the ICU specialty. We performed a nationwide web-based anonymized survey, including all German ICUs registered with the German Society for Neurointensive and Emergency Care (Deutsche Gesellschaft für Neurointensiv- und Notfallmedizin; DGNI). The response rate was 83/232 (36%). Continuous EEG monitoring (cEEG) was available in 86% of ICUs. Regular written cEEG reports were obtained in only 50%. Drug management was homogeneous with a general consensus regarding substance order: benzodiazepines—anticonvulsants—sedatives. Thereunder first choice substances were lorazepam (90%), levetiracetam (91%), and propofol (73%). Data suggest that network structures for super-refractory SE are not permeable, as 75% did not transfer SE patients. Our survey provides “real world data” concerning the current management of SE in Germany. Uniform standards in the implementation of cEEG could help further improve the overall quality. Initial therapy management is standardized. For super-refractory SE, a concentration of highly specialized centers establishing network structures analogous to neurovascular diseases seems desirable to apply rescue therapies with low evidence carefully, ideally collecting data on this rare condition in registries and clinical trials.
Management of the Secondary Spontaneous Pneumothorax: Current Guidance, Controversies, and Recent Advances
Authors: Nava George William , Walker Steven Philip
Published: February 2022

Secondary spontaneous pneumothorax (SSP) is a medical emergency where the lung collapses in the presence of underlying chronic lung disease. It is the commonest cause of spontaneous pneumothorax and results in significant breathlessness, higher morbidity, mortality, and longer hospital admissions than with patients with pneumothoraces and no underlying lung disease. This article explores the current guidance, controversies, and recent advances in the management of this condition.
The Influence of Atrial Fibrillation on In-Hospital Mortality in People with Hospital-Acquired Pneumonia: An Observational, Sex-Stratified Study
Authors: de Miguel-Yanes Jose M. , Jimenez-Garcia Rodrigo , de Miguel-Diez Javier , Hernandez-Barrera Valentin , Mendez-Bailon Manuel , Zamorano-Leon Jose J. , Lopez-de-Andres Ana
Published: February 2022

(1) Background: The study aimed to analyze the influence of atrial fibrillation (AF) prior to hospital admission (“prevalent”) and new-onset AF diagnosed during hospital admission (“incident”) on in-hospital mortality (IHM) in women and men who developed hospital-acquired pneumonia (HAP) in Spain (2016–2019). (2) Methods: We used the Spanish Register of Specialized Care-Basic Minimum Database. (3) Results: We analyzed 38,814 cases of HAP (34.6% women; 13.5% ventilator-associated). Prevalent AF was coded in 19.9% (n = 7742), and incident AF in 5.5% (n = 2136) of HAP. Crude IHM was significantly higher for prevalent AF (34.22% vs. 27.35%, p < 0.001) and for incident AF (35.81% vs. 28.31%, p < 0.001) compared to no AF. After propensity score matching, IHM among women and men with prevalent AF was higher than among women and men with no AF (among women, 32.89% vs. 30.11%, p = 0.021; among men, 35.05% vs. 32.46%, p = 0.008). Similarly, IHM among women and men with incident AF was higher than among women and men with no AF (among women, 36.23% vs. 29.90%, p = 0.013; among men, 35.62% vs. 30.47%; p = 0.003). Sex was associated with a higher IHM only in people with incident AF (for female, OR = 1.21; 95% CI: 1.01–1.57). (4) Conclusions: Both prevalent and incident AF were associated with higher IHM in people who developed HAP. Female sex was associated with a higher IHM in incident AF.
Exploring the Relationships between Four New Species of Boletoid Fungi from Northern China and Their Related Species
Authors: Wang Yang , Tuo Yong-Lan , Wu Dong-Mei , Gao Neng , Zhang Zhen-Hao , Rao Gu , Wang Xiao-Min , Wang Jing , Dai Dan , Li Yu , Zhang Bo
Published: February 2022

The family Boletaceae primarily represents ectomycorrhizal fungi, which play an essential ecological role in forest ecosystems. Although the Boletaceae family has been subject to a relatively global and comprehensive history of work, novel species and genera are continually described. During this investigation in northern China, many specimens of boletoid fungi were collected. Based on the study of their morphology and phylogeny, four new species, Butyriboletus pseudoroseoflavus, Butyriboletus subregius, Tengioboletus subglutinosus, and Suillellus lacrymibasidiatus, are introduced. Morphological evidence and phylogenetic analyses of the single or combined dataset (ITS or 28S, rpb1, rpb2, and tef1) confirmed these to be four new species. The evidence and analyses indicated the new species’ relationships with other species within their genera. Detailed descriptions, color photographs, and line drawings are provided. The species of Butyriboletus in China were compared in detail and the worldwide keys of Tengioboletus and Suillellus were given.
Medical/Surgical, Cloth and FFP/(K)N95 Masks: Unmasking Preference, SARS-CoV-2 Transmissibility and Respiratory Side Effects
Authors: Mouliou Dimitra S. , Pantazopoulos Ioannis , Gourgoulianis Konstantinos I.
Published: February 2022

Background: Social distancing and mask-wearing were recommended and mandatory for people during the COVID-19 pandemic. Methods: A web-based questionnaire was disseminated through social media assessing mask type preference and COVID-19 history amongst tertiary sector services and the rates of the triad of respiratory symptoms in each mask type, along with other respiratory-related parameters. Results: Amongst 4107 participants, 63.4% of the responders, mainly women, preferred medical/surgical masks; 20.5%, mainly men, preferred cotton cloth masks; and 13.8% preferred FFP/(K)N95 masks. COVID-19 history was less common in FFP/(K)N95 compared to medical/surgical (9.2% vs. 15.6%, p < 0.001) or cloth masks (9.2% vs. 14.4%, p = 0.006). Compared to the control group (rare mask-wearing, nonsmokers and without lung conditions), those wearing one medical mask were more likely to report frequent sputum production (4.4% vs. 1.9%, p = 0.026) and frequent cough (4.4% vs. 1.6%, p = 0.013), and those wearing FFP/(K)N95 masks were more likely to report frequent cough (4.1% vs. 1.6%, p = 0.048). Compared to the control group, those preferring cotton cloth masks were more likely to report a frequent cough (7.3% vs. 1.6%, p = 0.0002), sputum production (6.3% vs. 1.9%, p = 0.003) and dyspnea (8% vs. 1.3%, p = 0.00001). Conclusions: Safe mask-wearing should be in parallel with a more personalized and social interaction approach.
A Machine Learning Approach to Predict the Rehabilitation Outcome in Convalescent COVID-19 Patients
Authors: Adamo Sarah , Ambrosino Pasquale , Ricciardi Carlo , Accardo Mariasofia , Mosella Marco , Cesarelli Mario , d’Addio Giovanni , Maniscalco Mauro
Published: February 2022

Background: After the acute disease, convalescent coronavirus disease 2019 (COVID-19) patients may experience several persistent manifestations that require multidisciplinary pulmonary rehabilitation (PR). By using a machine learning (ML) approach, we aimed to evaluate the clinical characteristics predicting the effectiveness of PR, expressed by an improved performance at the 6-min walking test (6MWT). Methods: Convalescent COVID-19 patients referring to a Pulmonary Rehabilitation Unit were consecutively screened. The 6MWT performance was partitioned into three classes, corresponding to different degrees of improvement (low, medium, and high) following PR. A multiclass supervised classification learning was performed with random forest (RF), adaptive boosting (ADA-B), and gradient boosting (GB), as well as tree-based and k-nearest neighbors (KNN) as instance-based algorithms. Results: To train and validate our model, we included 189 convalescent COVID-19 patients (74.1% males, mean age 59.7 years). RF obtained the best results in terms of accuracy (83.7%), sensitivity (84.0%), and area under the ROC curve (94.5%), while ADA-B reached the highest specificity (92.7%). Conclusions: Our model enables a good performance in predicting the rehabilitation outcome in convalescent COVID-19 patients.
Cost-Effectiveness of Screening Algorithms for Familial Hypercholesterolaemia in Primary Care
Authors: Jones Matthew , Akyea Ralph K. , Payne Katherine , Humphries Steve E. , Abdul-Hamid Hasidah , Weng Stephen , Qureshi Nadeem
Published: February 2022

Although familial hypercholesterolemia (FH) screening within primary care is considered cost-effective, which screening approach is cost-effective has not been established. This study determines the cost-effectiveness of six case-finding strategies for screening of electronic health records to identify index patients who have genetically confirmed monogenic FH in English primary care. A decision tree was constructed to represent pathways of care for each approach (FH Case Identification Tool (FAMCAT) versions 1 and 2, cholesterol screening, Dutch Lipid Clinic Network (DLCN), Simon Broome criteria, no active screening). Clinical effectiveness was measured as the number of monogenic FH cases identified. Healthcare costs for each algorithm were evaluated from an NHS England perspective over a 12 week time horizon. The primary outcome was the incremental cost per additional monogenic FH case identified (ICER). FAMCAT2 was found to dominate (cheaper and more effective) cholesterol and FAMCAT1 algorithms, and extendedly dominate DLCN. The ICER for FAMCAT2 vs. no active screening was 8111 GBP (95% CI: 4088 to 14,865), and for Simon Broome vs. FAMCAT2 was 74,059 GBP (95% CI: −1,113,172 to 1,697,142). Simon Broome found the largest number of FH cases yet required 102 genetic tests to identify one FH patient. FAMCAT2 identified fewer, but only required 23 genetic tests.
Vinculum of Sustainable Development Goal Practices and Firms’ Financial Performance: A Moderation Role of Green Innovation
Authors: Khan Parvez Alam , Johl Satirenjit Kaur , Akhtar Shakeb
Published: February 2022

The 2030 Agenda for Sustainable Development (SDGs) has been established to alter our world by addressing the challenges faced by humanity in order to promote wellbeing, economic prosperity, and the protection of the environment. The SDGs provide a holistic and multi-dimensional approach to development compared to conventional development plans that focus on a limited range of dimensions. As a result, linkages between the SDGs may result in differing outcomes. This research is the first to investigate the direct relationship of environmental and social SDGs with firms’ financial performance and the moderating role of green innovation. Data from 67 companies from five continents (Europe, Australia and New Zealand, Asia, North America, and Africa) and their top five blue-chip firms were collected through content analysis. Generalized least squares (GLS) were used to test for direct relationships. The results showed a positive correlation between environmental SDGs and the negative significance of social SDGs on firms’ financial performance. However, mixed findings regarding the moderation variable green innovation over SDGs and firms’ financial performance were found. The new findings extend the SDG literature and provide empirical evidence to practitioners and policymakers.
Correction: Peponi, A.; Morgado, P. Transition to Smart and Regenerative Urban Places (SRUP): Contributions to a New Conceptual Framework. Land 2021, 10, 2
Authors: Peponi Angeliki , Morgado Paulo
Published: February 2022

Error in Figure/Table Caption [...]
Evaluating the Impact of Ecological Property Rights to Trigger Farmers’ Investment Behavior—An Example of Confluence Area of Heihe Reservoir, Shaanxi, China
Authors: Li Min , Sarkar Apurbo , Wang Yuge , Khairul Hasan Ahmed , Meng Quanxing
Published: February 2022

Property rights of natural resources have been acting as a critical legislative tool for promoting sustainable resource utilization and conservation in various regions of the globe. However, incorporating ecological property rights into the natural resources property rights structure may significantly influence farmers’ behavior in forestry investment. It may also trigger forest protection, water conservation, and urban water security. The main aim of the research is to evaluate the impact of ecological property rights and farmers’ investment behavior in the economic forest. We have constructed an analytical framework of collective forest rights from two indicators of integrity and stability, by adopting the theory of property rights and ecological capital to fulfill the study’s aims. The empirical data has been comprised of the microdata of 708 farmers, collected from the confluence area of the Heihe Reservoir, Shaanxi, China. The study also conducted pilot ecological property rights transactions in the surveyed area. The study utilized the double-hurdle model to test the proposed framework empirically. The results show that forest land use rights, economic products, and eco-product income rights positively affect farmers’ forestry investment intensity, and disposal rights (forest land transfer rights) negatively affect farmers’ investment intensity. However, in terms of the integrity of property rights, only the right to profit from ecological products affects farmers’ forestry investment willingness, and other property rights are insignificant. The study also found that the lower the farmers’ forest land expropriation risk is expected, the greater the possibility of investment and the higher the input level. However, we traced that the farmers’ forest land adjustment has no significant impact on farmers’ willingness to invest. Obtaining the benefits of ecological products has been found as the primary motivation for forestry investment within the surveyed area. The completeness of ownership rights positively impacted farmers’ investment intensity. Farmers should realize the ecological value of water conservation forests through the market orientation of the benefit of ecological products. Therefore, the government should encourage farmers and arrange proper training to facilitate a smooth investment. A well-established afforestation program should also be carried out.
A Review on the Efficacy and Safety of Nab-Paclitaxel with Gemcitabine in Combination with Other Therapeutic Agents as New Treatment Strategies in Pancreatic Cancer
Authors: Chapa-González Christian , López Karina , Lomelí Kimberly Michelle , Roacho-Pérez Jorge Alberto , Stevens Jazmín Cristina
Published: February 2022

Pancreatic cancer has one of the highest mortality rates among cancers, and a combination of nab-paclitaxel with gemcitabine remains the cornerstone of first-line therapy. However, major advances are required to achieve improvements in patient outcomes. For this reason, several research groups have proposed supplementing treatment with other therapeutic agents. Ongoing studies are being conducted to find the optimal treatment in a first-line setting. In this work, we used a search strategy to compare studies on the efficacy and safety of nab-paclitaxel with gemcitabine in combination with other therapeutic agents based on the criteria of the Preferred Reporting Items for Systematic Reviews. We found seven studies in different clinical phases that met the inclusion criteria. The seven therapeutic agents were ibrutinib, necuparanib, tarextumab, apatorsen, cisplatin, enzalutamide, and momelotinib. Although these therapeutic agents have different mechanisms of action, and molecular biology studies are still needed, the present review was aimed to answer the following question: which formulations of the nab-paclitaxel/gemcitabine regimen in combination with other therapeutic agents are safest for patients with previously untreated metastatic pancreas ductal adenocarcinoma? The triple regimen is emerging as the first-line option for patients with pancreatic cancer, albeit with some limitations. Thus, further studies of this regimen are recommended.
Lavandula pedunculata (Mill.) Cav. Aqueous Extract Antibacterial Activity Improved by the Addition of Salvia rosmarinus Spenn., Salvia lavandulifolia Vahl and Origanum compactum Benth
Authors: Boutahiri Salima , Eto Bruno , Bouhrim Mohamed , Mechchate Hamza , Saleh Asmaa , Al kamaly Omkulthom , Drioiche Aziz , Remok Firdaous , Samaillie Jennifer , Neut Christel , Gressier Bernard , Kouoh Elombo Ferdinand , Nassiri Laila , Zair Touriya , Sahpaz Sevser
Published: February 2022

Lavender aqueous extracts are widely used in the Moroccan traditional medicine for their antibacterial properties. However, previous research have generally focused on investigating the antibacterial activity of lavender essential oils. The aim of this study is to evaluate the antibacterial activity of the Moroccan Lavandula pedunculata (Mill.) Cav. aqueous extract, alone, as well as in combination with extracts of other plant species known for their antibacterial activity: Salvia rosmarinus Spenn., Salvia lavandulifolia Vahl. and Origanum compactum Benth. We have tested the antibacterial activity of L. pedunculata, S. rosmarinus, S. lavandulifolia and O. compactum aqueous extracts individually and in combination against 34 strains using the agar dilution method. The combination effect was evaluated using the fractional inhibitory concentration (FIC). Polyphenol and tannin contents were determined using Folin-Ciocalteu reagent, and then some phenolic compounds were identified using UHPLC-MS. All the extracts displayed a large spectrum of antibacterial activity, especially against staphylococci, streptococci, Mycobacterium smegmatis and Proteus mirabilis. The minimum inhibitory concentration (MIC) values reached 0.15 ± 0.00 mg/mL for Staphylococcus warneri tested with S. lavandulifolia and 0.20 ± 0.07 mg/mL for Staphylococcus epidermidis tested with L. pedunculata or S. rosmarinus. Association of the L. pedunculata extract with S. rosmarinus, S. lavandulifolia and O. compactum showed synergistic effects (FIC ≤ 1). Moreover, the association of L. pedunculata with S. lavandulifolia was active against most of the Gram-negative strains resistant to the individual extracts. Determination of polyphenol and tannin contents showed the richness of the studied plants in these compounds. Additionally, chromatographic analysis demonstrated the high presence of rosmarinic acid in all the studied plant extracts. To our knowledge, this is the first study that shows the enhancing effect of the antibacterial activity of L. pedunculata aqueous extract combined with S. rosmarinus, S. lavandulifolia and O. compactum. These results confirm the effectiveness of the plant mixtures commonly used by traditional healers in Morocco and suggest that L. pedunculata might be used as an antibacterial agent either alone or, more efficiently, in combination with S. rosmarinus, S. lavandulifolia and O. compactum.
Experimental Study and Verification of New Monolithic Rotary Cutting Tool for an Active Driven Rotation Machining
Authors: Czán Andrej , Joch Richard , Šajgalík Michal , Holubják Jozef , Horák Andrej , Timko Pavol , Valíček Jan , Kušnerová Milena , Harničárová Marta
Published: February 2022

Forced rotation turning appears to be an effective machining method due to higher tool life, time efficiency and acceptable quality. Several studies have been carried out to investigate the basic characteristics of forced rotation machining. So far, tools are used whose design included several components. However, such tools may generate vibrations, which are undesirable in the process. In engineering practice, most vibration problems are solved by reducing the cutting parameters (cutting speed and feed rate), which reduces machining productivity. For this reason, a new type of monolithic rotary tool has been designed that eliminates the design complexity and high assembly accuracy requirements of current rotary tools. Based on the performed experimental research, it is possible to define the influence of cutting parameters on the cutting force. Next, the equation of the cutting force and the resulting roughness of the machined surface was determined. In the introduction, the results of the analysis of machining parameters with a rotary tool were added. The presented solution fundamentally validates the new monolithic tool for forced rotation technology and defines its application for different machining materials.
Effect of Al Addition on Grain Refinement and Phase Transformation of the Mg-Gd-Y-Zn-Mn Alloy Containing LPSO Phase
Authors: Zuo Jing , Zhang Mingquan , Nakata Taiki , Wang Guisong , Li Danyang , Shi Hailong , Xu Chao , Wang Xiaojun , Li Wenjun , Fan Guohua , Geng Lin , Kamado Shigeharu
Published: February 2022

The effect of 0–1.0 at.% Al additions on grain refinement and phase transformation of the Mg-2.0Gd-1.2Y-0.5Zn-0.2Mn (at.%) alloy containing a long period stacking ordered (LPSO) phase was investigated in this work. The addition of Al promoted the formation of the Al2RE phase in the Mg-2.0Gd-1.2Y-0.5Zn-0.2Mn (at.%) alloy, and the dominant secondary phases in the as-cast Mg-2.0Gd-1.2Y-0.5Zn-0.2Mn-1.0Al (at.%) alloy were the Mg3RE phase, LPSO phase, and Al2RE phase. With increased Al addition, the area fraction of the Al2RE phase increased monotonously, while the area fraction of LPSO phase and Mg3RE phase decreased gradually. The orientation relationship between the Al2RE phase and the α-Mg matrix was determined to be <112>Al2RE//<112¯0>α-Mg, {101}Al2RE//{101¯0}α-Mg, which was not affected by Zn and Mn concentrations in the Al2RE phase. Since the Al2RE particles with a size more than 6 μm located at the center of grains could act as nucleants for α-Mg grains, the average grain size of the as-cast alloys decreased from 276 μm to 49 μm after 1.0% Al addition. The effect of the Al addition on the grain refinement of the Mg-2.0Gd-1.2Y-0.5Zn-0.2Mn alloy was comparable to that of the Zr refined counterpart.
Characterizing the Effect of Adding Boron Nitride Nanotubes on the Mechanical Properties of Electrospun Polymer Nanocomposite Microfibers Mesh
Authors: Alsmairat Ohood , Barakat Nael
Published: February 2022

Electrospun fibrous meshes have a variety of applications such as filtration, drug delivery, energy storage, and engineered tissues due to their high surface area to mass ratio. Therefore, understanding the mechanical properties of these continuously evolving meshes is critical to expand and improve their performance. In this study, the effect of adding Boron Nitride Nanotube (BNNT) to Polymethylmethacrylate (PMMA) composite meshes on the mechanical properties of the polymer is studied. Electrospinning is used to fabricate microfiber meshes of PMMA and BNNT-PMMA. The fabricated meshes are tested experimentally with a uniaxial tensile tester. In addition, a theoretical model is introduced to investigate the effect of the number of fibers and the diameter of fiber inside the mesh on Young’s Modulus and Tensile Strength of the PMMA mesh. By adding 0.5% BNNT to the PMMA, Young’s Modulus and Tensile Strength of the PMMA mesh improved by 62.4% and 9.3%, respectively. Furthermore, simulated results show enhanced mesh properties when increasing the number of fibers and the single fiber diameter inside the mesh. The findings of this study help in understanding the mechanical properties of the nanocomposite electrospun meshes which expands and improves its utilization in different applications.
Calibration and Validation of a Linear-Elastic Numerical Model for Timber Step Joints Based on the Results of Experimental Investigations
Authors: Braun Matthias , Pełczyński Jan , Al Sabouni-Zawadzka Anna , Kromoser Benjamin
Published: February 2022

The paper is dedicated to the numerical analysis of a single-step joint, enabling the prediction of stiffness and failure modes of both single- and double-step joints. An experimental analysis of the geometrically simplest version, the single-step joint, serves as a reference for the calibration of the subsequent finite element model. The inhomogeneous and anisotropic properties of solid timber make detailed modelling computationally intensive and strongly dependent on the respective specimen. Therefore, the authors present a strategy for simplified but still appropriate modelling for the prediction of local failure at certain load levels. The used mathematical approach is based on the linear elasticity theory and orthotropic material properties. The finite element calculations are performed in the environment of the software Abaqus FEA. The calibrated numerical model shows a good conformity until first failures occur. It allows for a satisfactory quantification of the stiffness of the connection and estimation of the force when local failure begins and is, therefore, recommended for future, non-destructive research of timber connections of various shapes.
Effects of Microstructure Modification by Friction Surfacing on Wear Behavior of Al Alloys with Different Si Contents
Authors: Schütte Malte R. , Ehrich Jonas , Linsler Dominic , Hanke Stefanie
Published: February 2022

In this work, Al alloys with 6.6%, 10.4%, and 14.6% Si were deposited as thick coatings by Friction Surfacing (FS), resulting in grain refinement and spheroidization of needle-shaped eutectic Si phase. Lubricated sliding wear tests were performed on a pin-on-disc tribometer using Al-Si alloys in as-cast and FS processed states as pins and 42CrMo4 steel discs. The chemical composition of the worn surfaces was analyzed by X-ray photoelectron spectroscopy (XPS). The wear mechanisms were studied by scanning electron microscopy (SEM) and focused ion beam (FIB), and the wear was evaluated by measuring the weight loss of the samples. For the hypoeutectic alloys, spheroidization of the Si phase particles in particular leads to a significant improvement in wear resistance. The needle-shaped Si phase in as-cast state fractures during the wear test and small fragments easily detach from the surface. The spherical Si phase particles in the FS state also break away from the surface, but to a smaller extent. No reduction in wear due to FS was observed for the hypereutectic alloy. Here, large bulky primary Si phase particles are already present in the as-cast state and do not change significantly during FS, providing high wear resistance in both material states. This study highlights the mechanisms and limitations of improved wear resistance of Si-rich Al alloys deposited as thick coatings by Friction Surfacing.
Material Removal and Surface Integrity Analysis of Ti6Al4V Alloy after Polishing by Flexible Tools with Different Rigidity
Authors: Ke Xiaolong , Wu Wei , Wang Chunjin , Yu Yongheng , Zhong Bo , Wang Zhenzhong , Wang Tianyi , Fu Jianji , Guo Jiang
Published: February 2022

Ti6Al4V alloy has been widely used in many fields, such as aerospace and medicine, due to its excellent biocompatibility and mechanical properties. Most high-performance components made of Ti6Al4V alloy usually need to be polished to produce their specific functional requirements. However, due to the material properties of Ti6Al4V, its polishing process still requires significant development. Therefore, this study aimed to investigate the performance of polishing Ti6Al4V by using tools with different rigidities. Two kinds of bonnet tool were used, namely a pure rubber (PR) bonnet and a semirigid (SR) bonnet. The characterization of material removal and surface integrity after polishing was conducted through a series of experiments on a 6-DOF robotic polishing device. The results demonstrate that both bonnet tools successfully produce nanometric level surface roughness. Moreover, the material removal rate of the SR bonnet tool is significantly higher than that of the PR bonnet, which is consistent with the material removal characteristics of glass polishing in previous research. In addition, the presented analysis on key polishing parameters and surface integrity lays the theoretical foundation for the polishing process of titanium alloy in different application fields.
Influence of Cryo-Processing and Post-SPD Annealing on Creep Behavior of CP Titanium
Authors: Dvorak Jiri , Kral Petr , Kadomtsev Andrey G. , Betekhtin Vladimir I. , Narykova Maria V. , Kvapilova Marie , Sklenicka Vaclav
Published: February 2022

The commercial purity of VT1-0 titanium was processed by the rolling process and executed at elevated, room, and cryo-temperatures. These processings led to the formation of an ultrafine-grained microstructure, with the mean grain size at a nanometer level. Some of these materials were statically annealed at a temperature of 823 K for 1 h, which led to significant subgrains and grain coarsening. The constant load creep tests in tension were carried out in argon on all states of materials, at temperatures of 648–723 K and different ranges of applied stresses. From the value of the steady-state creep rate, the control creep mechanisms were determined. The microstructure analyses were carried out via SEM and TEM. It was found that titanium prepared at elevated and room temperatures have a higher creep strength than titanium prepared at cryo-temperatures. Furthermore, the post-SPD —annealing led to a significant decrease in the creep properties. The influence of the preparation temperature on the difference of the creep behavior were discussed and explained using the microstructure analyses of the tests’ samples.
Functional Investigation of Geometrically Scaled Drive Components by X-in-the-Loop Testing with Scaled Prototypes
Authors: Steck Michael , Matthiesen Sven , Gwosch Thomas
Published: February 2022

Validation is important for a high product quality of drive components. An X-in-the-Loop test bench enables the integration of scaled prototypes through coupling systems and scaling models even before serial parts are available. In the context of X-in-the-loop investigations, it is still unclear whether a scaling model enables the early investigation of geometry variants in powertrain subsystems. In this paper, scaled geometry experiments taking into account the interacting system are considered to evaluate the scaling model in terms of early investigation of geometry variants. The aim of this paper is the functional investigation of geometrically scaled drive components by integrating scaled prototypes in an X-in-the-Loop test bench. Using an overload clutch with detents, component variants of different size levels are investigated in scaled experiments with a scaling model. The results confirm possibilities of X-in-the-Loop integration of scaled prototypes and their investigation on geometrically scaled drive components. The investigations show, therefore, the opportunities of integrating scaled drive components through the scaling model to support the investigation of geometry variants before serial parts are available. Scaled geometry investigations considering the interacting system can, thus, support product development.
Relative Symmetric Reductions under Multi-Choice Non-Transferable-Utility Situations
Authors: Liao Yu-Hsien
Published: February 2022

In many game-theoretical results, the reduction axiom and its converse have been regarded as important requirements under axiomatic processes for solutions. However, it is shown that the replicated core counters a specific (inferior) converse reduction axiom under multi-choice non-transferable-utility situations. Thus, two modified reductions and relative properties of the reduction axiom and its converse are proposed to characterize the replicated core in this article.The main methods and relative results are as follows. First, two different types of reductions are proposed by focusing on both participants and participation levels under relative symmetric reducing behavior. Further, relative reduction axioms and their converse are adopted to characterize the replicated core.
Second-Order Spatial-Temporal Correlation Filters for Visual Tracking
Authors: Yu Yufeng , Chen Long , He Haoyang , Liu Jianhui , Zhang Weipeng , Xu Guoxia
Published: February 2022

Discriminative correlation filters (DCFs) have been widely used in visual object tracking, but often suffer from two problems: the boundary effect and temporal filtering degradation. To deal with these issues, many DCF-based variants have been proposed and have improved the accuracy of visual object tracking. However, these trackers only adopt first-order data-fitting information and have difficulty maintaining robust tracking in unconstrained scenarios, especially in the case of complex appearance variations. In this paper, by introducing a second-order data-fitting term to the DCF, we propose a second-order spatial–temporal correlation filter (SSCF) learning model. To be specific, the SSCF tracker both incorporates the first-order and second-order data-fitting terms into the DCF framework and makes the learned correlation filter more discriminative. Meanwhile, the spatial–temporal regularization was integrated to develop a robust model in tracking with complex appearance variations. Extensive experiments were conducted on the benchmarking databases CVPR2013, OTB100, DTB70, UAV123, and UAVDT-M. The results demonstrated that our SSCF can achieve competitive performance compared to the state-of-the-art trackers. When penalty parameter λ was set to 10−5, our SSCF gained DP scores of 0.882, 0.868, 0.706, 0.676, and 0.928 on the CVPR2013, OTB100, DTB70, UAV123, and UAVDT-M databases, respectively.
Isoporous Polyvinylidene Fluoride Membranes with Selective Skin Layers via a Thermal-Vapor Assisted Phase Separation Method for Industrial Purification Applications
Authors: Choi Da Han , Kwon Sei , Yoo Youngmin , Kim In-Chul , Park Hosik , Park You-In , Yang Sung Yun , Nam Seung-Eun , Cho Young Hoon
Published: February 2022

The membrane filtration process is the most widely used purification process in various industries due to its high separation efficiency, process simplicity, and low cost. Although there is a wide range of membrane products with diverse materials and pore sizes on the market, there is a technological gap between microfiltration and ultrafiltration membranes. Here we developed highly porous polyvinylidene fluoride (PVDF) membranes with a selective skin layer with a pore size range of 20 to 80 nm by using a thermal-vapor assisted phase separation method. Porous and bi-continuous sublayers were generated from spinodal decomposition induced by cooling. The overall membrane structure and pore size changed with the dope composition, while the pore size and thickness of the selective skin layer were effectively controlled by water vapor exposure. The excellent nanoparticle removal efficiencies of the prepared PVDF membranes were confirmed, indicating their potential application in high-level purification processes to remove small trace organic or inorganic impurities from various industrial fluids.
Photoinduced Oxidation of Lipid Membranes in the Presence of the Nonsteroidal Anti-Inflammatory Drug Ketoprofen
Authors: Mastova Anna V. , Selyutina Olga Yu. , Evseenko Veronika I. , Polyakov Nikolay E.
Published: February 2022

The damage of cell membranes induced by photosensitive drugs has attracted the significant attention of researchers in various fields of medicine. Ketoprofen (KP) is known to be the most photosensitive among the nonsteroidal anti-inflammatory drugs. The phototoxic side effects of KP and other non-steroidal anti-inflammatory drugs are associated with the action of free radicals, but there is insufficient information about the nature of these radicals. In the present study, free radicals formed upon KP irradiation within lipid membranes were studied using nuclear magnetic resonance (NMR) and chemically induced dynamic nuclear polarization (CIDNP) methods, as well as a molecular dynamics simulation. Our study confirmed the effective penetration of KP into the lipid bilayer and showed a significant effect of the nature of the medium on the photolysis mechanism. While, in a homogeneous solution, the main channel of KP photolysis is free radical-mediated monomolecular decomposition with formation of radical pairs of benzyl and CO2H● radicals, then, in the lipid membrane, the reaction route shifts towards the bimolecular reaction of KP photoreduction. In addition, the effect of the presence an electron donor (the amino acid tryptophan) on lipid oxidation has been studied. It was found that photoreaction of KP with tryptophan proceeds more efficiently than with lipid molecules.
Effect of Neutron Flux on an Irradiation-Induced Microstructure and Hardening of Reactor Pressure Vessel Steels
Authors: Ulbricht Andreas , Hernández-Mayoral Mercedes , Oñorbe Elvira , Etienne Auriane , Radiguet Bertrand , Hirschmann Eric , Wagner Andreas , Hein Hieronymus , Bergner Frank
Published: February 2022

The existing knowledge about the effect of neutron irradiation on the mechanical properties of reactor pressure vessel steels under reactor service conditions relies to a large extent on accelerated irradiations realized by exposing steel samples to a higher neutron flux. A deep understanding of flux effects is, therefore, vital for gaining service-relevant insight into the mechanical property degradation. The existing studies on flux effects often suffer from incomplete descriptions of the irradiation-induced microstructure. Our study aims to give a detailed picture of irradiation-induced nanofeatures by applying complementary methods using atom probe tomography, positron annihilation, small-angle neutron scattering and transmission electron microscopy. The characteristics of the irradiation-induced nanofeatures and the dominant factors responsible for the observed increase of Vickers hardness are identified. Microstructural changes due to high flux conditions are smaller nm-sized solute atom clusters with almost the same volume fraction and a higher concentration of vacancies and sub-nm vacancy clusters compared to low flux conditions. The results rationalize why pronounced flux effects on the nanofeatures, in particular on solute atom clusters, only give rise to small or moderate flux effects on hardening.
Effect of Heat Treatment on Microstructural Evolution and Microhardness Change of Al-5Zn-0.03In-1Er Alloy
Authors: Cui Jin , Tang Zhichao , Yu Muzhi , Hu Jiajin , Chen Xiaoyang , Xu Zhengbing , Zeng Jianmin
Published: February 2022

Adding an appropriate amount of Er element to Al-Zn-In alloys can improve the electrochemical performance of Al alloys; it is convenient to study the electrochemical behavior of the alloy in the rest of our work. However, Er segregation in solid solutions which reduced the comprehensive properties of alloys was difficult to reduce and there was no report on the homogenization of Al-Zn-In alloys. We found that the ultra-high temperature treatment (UHTT) can obviously reduce Er segregation. To explore the better homogenization treatment and the microstructure evolution of Al-5Zn-0.03In-1Er alloy after UHTT, we carried out a series of heat treatments on the alloy and characterized the microstructure of the alloy by optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy spectrum analysis (EDS) and transmission electron microscopy (TEM). The results showed that the main element Er of the Al-Zn-In-Er was largely enriched in grain boundaries after UHTT; the distribution Zn and In was almost unchanged. The as-cast Al-Zn-In-Er alloy consisted mainly of α(Al) solid solution and Al3Er phase. As the temperature of UHTT increased and the treatment time prolonged, the precipitated phase dissolved into the matrix, and there were dispersed Al3Er particles in the crystal. The proper UHTT for reducing the interdendritic segregation of the alloy was 615 °C × 32 h, which was properly consistent with the results of the evolution of the statistical amount of interdendritic phase, the line scanning analysis and the microhardness. Moreover, the microhardness of the alloy after treatment of 615 °C × 32 h was obviously higher than that of the as-cast alloy because of the anchoring effect of Al3Er nanoparticles on the movement of dislocations.