bluuebunny/crossref_metadata_2025 huggingface dataset:
Organized Breast and Cervical Cancer Screening: Attendance and Determinants in Rural China
Authors: Han Huinan , Wang Xiaoyu , Zhu Yimei , Liang Yuan
Published: July 2022

To evaluate the attendance and determinants of organized cervical and breast cancer (two-cancer) screening, especially higher-level factors, we conducted a cross-sectional survey in central China from June 2018 to November 2019 among 1949 women (age ≥ 35 years). We examined organizer-level factors, provider-level factors, receiver-lever factors and attendance and participation willingness of screening. The results indicate that the attendance and participation willingness of organized two-cancer screening was 61.19% and 77.15%, respectively. After adjustment for potential confounders, women who received screening notification were more likely to have greater participation willingness and higher attendance than those who received no notification (adjusted odds ratio [aOR] = 1.59, 95% confidence interval [CI]: 1.27–1.99; aOR = 98.03, 95% CI: 51.44–186.82, respectively). Compared with being notified about screening by GPs, being notified by community women’s leaders and other community leaders were more likely to lead to greater willingness to participate again (aOR = 2.86, 95% CI: 1.13–7.24; aOR = 3.27, 95% CI: 1.26–8.48, respectively) and recommending screening to others (aOR = 2.18, 95% CI: 1.02–4.65; aOR = 4.14, 95% CI: 1.84–9.30, respectively). The results suggest that notification of women about screening by community leaders is an important organizer-level factor. As a part of public health services, the design and implementation of optimal cancer screening strategies may require public-sector involvement at the organizer level instead of a one-man show by the health sector.
Estimation and Potential Analysis of Land Population Carrying Capacity in Shanghai Metropolis
Authors: Wang Hefeng , Cao Yuan , Wu Xiaohu , Zhao Ao , Xie Yi
Published: July 2022

It is of great practical significance to understand the current situation of urban land carrying capacity, explore its potential space, and continuously improve the economic adaptability and resilience and population carrying capacity of megacities. Based on the guiding principle of territorial spatial division and the concept of moderate-scale resilient cities, combined with GIS technology, this study aims to divide land spaces into three types and construct different index systems to evaluate the land carrying capacity of Shanghai in different spaces. Furthermore, we propose different schemes of estimating subspace land population carrying capacity, and the carrying potential of land population is analysed as well. The acquired results demonstrate three key points. Firstly, the total land population capacity of Shanghai is estimated at 25,476.61–32,047.27 people, with urban land space being the most dominant for the city’s population carrying capacity. Furthermore, the inner suburbs carry the largest population, and the urban centre carries a larger population density than other areas. Secondly, there are significant spatial differences in land population carrying potential. Compared with the demographic data from 2017, Shanghai still has a population carrying potential of 1293.30–7863.97 people and a suitable population carrying potential of 4578.64 people. The population of the urban centre is near the upper limit of the estimated population carrying capacity, and the suburbs, especially the outer suburbs, have large population carrying potential. Thirdly, the estimation method adopted in this study can effectively reveal the spatial differences in population carrying capacity and the potential of different land spaces and different regions in Shanghai, with the estimation results being highly credible. The results will provide references for the improvement of the multi-scenario population planning strategy in Shanghai, as well as enrich the research span and methods currently employed in land carrying capacity.
Contribution Ratio of Metatarsal Osteotomy and First Tarsometatarsal Joint Reduction in Moderate to Severe Hallux Valgus Correction
Authors: Seo Dong-Kyo , Park Hasung , Song Myeong Geun , Jung Youngjoo , Choi Young-Rak
Published: July 2022

Hallux valgus is a common foot and ankle disease, for which numerous surgical procedures were introduced. So, understanding the mechanism of deformity reduction is important to select the proper method. Intermetatarsal angle (IMA) determines the severity of hallux valgus, which is influenced by the translated metatarsal head and the reduction of the first tarsometatarsal joint. We hypothesized that both of the mechanisms simultaneously contribute to the correction of IMA. Hallux valgus (70 feet) operated with a Scarf osteotomy with the Akin procedure were reviewed. Hallux valgus angle (HVA), IMA (mechanical and anatomical), hallux valgus interphalangeal angle (HVIP), distal metatarsal articular angle (DMAA), and sesamoid position were checked. The ratio of contributions to the IMA changes were calculated and compared. When the individual contributions by metatarsal head translation and first tarsometatarsal joint reduction were compared, metatarsal head translation contributed by 82%, whereas first tarsometatarsal joint reduction contributed by 18%. Both were responsible for mechanical IMA correction. However, IMA change by metatarsal head translation was a major correction mechanism compared to anatomical IMA change by first tarsometatarsal joint reduction.
Relevant Strength Parameters to Allow Return to Running after Primary Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft
Authors: Grondin Jérôme , Crenn Vincent , Gernigon Marie , Quinette Yonis , Louguet Bastien , Menu Pierre , Fouasson-Chailloux Alban , Dauty Marc
Published: July 2022

After anterior cruciate ligament reconstruction (ACLR), a progressive process is followed from rehabilitation to the return to sport including a crucial step known as the return to running. Return to running (RTR) can be predicted by an isokinetic knee strength assessment at 4 months post-surgery. All patients who had primarily undergone ACLR with a hamstring autograft procedure between 2010 and 2020 were included in this study. Four months after surgery, patients were evaluated using an isokinetic knee strength test. Patients were monitored until the 6th month post-surgery to see if they had returned to running. Comparisons were carried out between the two groups—the RTR and the no-RTR. A multivariate logistic regression analysis was used to predict the RTR status from explicative parameters. Receiver Operating Characteristic (ROC) curves were established to identify cutoffs with their characteristics. A total of 413 patients were included and 63.2% returned to running at 4 months post-surgery. The mean Lysholm score, knee complication rate, and isokinetic parameters were statistically different between both groups. Using a multivariate logistic regression model and ROC curves, the best isokinetic parameter to assist with the decision to allow an RTR was the quadriceps limb symmetry index at 60°/s with a cutoff of 65%. The hamstring LSI at 180°/s could be added (cutoff of 80%) to slightly increase the prediction of an RTR. Quadriceps strength normalized to body weight at 60°/s is a useful parameter (cutoff: 1.60 Nm/kg) but measurements on both sides are necessary. Isokinetic parameters are objective parameters to allow a return to running at 4 months after ACLR with a hamstring procedure.
Immigrant Parents’ Perceived Social Support and Their Children’s Oral Health Behaviors and Caries Experience
Authors: Dahlan Rana , Bohlouli Babak , Saltaji Humam , Kornerup Ida , Salami Bukola , Amin Maryam
Published: July 2022

This study examined the associations between immigrant parents’ perceived social support (PSS) and their children’s oral health behaviors (OHB) and caries experience. We recruited immigrant parents and children aged 2–12 years. Data were collected on the sociodemographic and OHB information of the children. The parents’ total PSS score and its dimensions were measured using the validated Personal Resource Questionnaire (PRQ2000). Dental examinations determined the children’s caries experience using the DMFT/dmft index. A total of 336 parents and children were included in the study. Household income predicted the parents’ PSS (B = −5.69; 95% CI −9.077, −2.32). Children of parents with higher PSS reported ≥2 toothbrushing/day (p ≤ 0.05). Among the PSS domains, parental education level predicted their social integration (B = −0.16; 95% CI −0.30, −0.02) and nurturance (B = −0.24; 95% CI −0.43, −0.06). Family income predicted social integration (B = −0.17; 95% CI −0.33 −0.01), worth (B = −0.23; 95% CI −0.39 −0.06), and assistance (B = −0.22; 95% CI −0.42 −0.01). Parents with higher scores of intimacy and social integration were more aware of their children’s oral health (p = 0.01). The parental social integration mean scores were significantly higher among parents whose children consumed ≥1 sugary snack/day (p = 0.02). All five domain scores were significantly higher among parents of children who reported ≥2 toothbrushing/day compared with children who brushed <2/day (p < 0.05). The results demonstrated that parents’ PSS only improved their children’s toothbrushing frequency. Compared to other domains, social integration was significantly associated with children’s OHB. Neither parental PSS total score nor domains were associated with DMFT/dmft.
Knowledge, Attitudes, and Practices in Relation to Mosquito-Borne Diseases in Bangladesh
Authors: Mobin Mir , Khan Mohammad , Anjum Hasnain , Rahman Habibur , Marzan Mahfuza , Islam Md Asiful
Published: July 2022

Mosquito-borne diseases (MBDs) such as dengue, malaria, and chikungunya are common in Bangladesh, with frequent outbreaks in the rainy season. Analysis of the knowledge, attitudes, and practices of people toward any crisis is fundamental to addressing any gap. Here, we conducted a cross-sectional study mainly focusing on the northern, southern and central parts of Bangladesh to understand the level of knowledge, attitudes, and practices of people regarding MBDs, mosquito habitats, or control measures. A total of 1720 participants were involved in the study from 33 out of 64 districts of Bangladesh, of which 56.9% were male. While most of them knew about dengue (97.1%), chikungunya (81.4%), and malaria (85.2%), only half of them were aware of filaria (53.3%), which is endemic to the northern region. A knowledge score (0–8, low), (9–16, moderate), (17–24, high), and attitude score (0–4, poor), (5–8, moderate), and (9–13, high) were assigned. While poor and moderate attitudes were considered negative, good attitudes were considered positive. About 45% of the respondents had a moderate knowledge score (50–70); however, about 67.9% of participants showed a good attitude score (>70) towards the control of MBDs. It was found that the knowledge and attitude of the responders were related to their profession (knowledge p < 0.001; attitude, p = 0.002), residential area (knowledge p < 0.001; attitude, p < 0.001), and education level (knowledge p < 0.001; attitude p = 0.004). A mosquito is a kind of nuisance bug, and about 79.8% of responders admitted that they kill mosquitoes as soon as they notice them. They also use bed nets (93.7%) followed by mosquito coils (85.7%) as a preventive method. Interestingly, 73.2% of the responders were reluctant to contact the local government during an increase in mosquito numbers. Overall, the people of Bangladesh have a positive attitude towards the prevention of mosquito-borne diseases. It is highly recommended that the government creates more knowledge regarding this issue and develops collaborative approaches with local people to implement robust preventive measures against mosquito-borne diseases.
Seasonal Pollution Characteristics of Antibiotics on Pig Farms of Different Scales
Authors: Du Delin , Zhou Jing , Zhang Keqiang , Zhi Suli
Published: July 2022

Scientific interest in pollution from veterinary antibiotics (VAs) on intensive animal farms has been increasing in recent years. However, limited information is available on the seasonal pollution characteristics and the associated ecological risks of VAs, especially about the different scale farms. Therefore, this study investigated the seasonal pollution status and ecological risks of 42 typical VAs (5 classes) on three different scale pig farms (breeding scales of about 30,000, 1200, and 300 heads, respectively) in Tianjin, China. The results showed that large-scale pig farms usually had the highest antibiotic pollution levels, followed by small-scale pig farms and medium-scale pig farms. Among different seasons, antibiotic contamination was more severe in winter and spring than that in the other seasons. Tetracyclines (TCs) usually had higher proportions (over 51.46%) and the residual concentration detected in manure, and wastewater samples ranged from not detected (ND)-1132.64 mg/kg and ND-1692.50 μg/L, respectively, which all occurred for oxytetracycline (OTC) during winter. For the antibiotic ecological risks in the effluent, we found high-risk level of 12 selected VAs accounted for 58% in spring, and 7 kinds of VAs were selected in the amended soil, but nearly all the antibiotics had no obvious ecological risks except OTC (spring and summer). All these data provided an insight into the seasonal variability and the associated ecological risks of antibiotics on intensive pig farms, which can provide scientific guidance on decreasing antibiotic contamination to enhance environmental security in similar areas.
The Fate of Epidermal Tight Junctions in the stratum corneum: Their Involvement in the Regulation of Desquamation and Phenotypic Expression of Certain Skin Conditions
Authors: Haftek Marek , Oji Vinzenz , Feldmeyer Laurence , Hohl Daniel , Hadj-Rabia Smaïl , Abdayem Rawad
Published: July 2022

We evaluated the presence of tight junction (TJ) remnants in the stratum corneum (SC) of in vitro reconstructed human epidermis and human skin explants subjected or not to an aggressive topical treatment with beta-lipohydroxy salicylic acid (LSA) for 24 h. LSA-treated samples showed an increased presence of TJ remnants in the two lowermost layers of the SC, as quantified with standard electron microscopy. The topical aggression-induced overexpression of TJ-like cell–cell envelope fusions may influence SC functions: (1) directly, through an enhanced cohesion, and (2) indirectly, by impeding accessibility of peripheral corneodesmosomes to extracellular hydrolytic enzymes and, thus, slowing down desquamation. Observations of ichthyotic epidermis in peeling skin disease (PSD; corneodesmosin deficiency; two cases) and ichthyosis hypotrichosis sclerosing cholangitis syndrome (IHSC/NISCH; absence of claudin-1; two cases) also demonstrated increased persistence of TJ-like intercellular fusions in pathological SC and contributed to the interpretation of the diseases’ pathological mechanisms.
Medicinal Hypervalent Tellurium Prodrugs Bearing Different Ligands: A Comparative Study of the Chemical Profiles of AS101 and Its Halido Replaced Analogues
Authors: Chiaverini Lorenzo , Cirri Damiano , Tolbatov Iogann , Corsi Francesca , Piano Ilaria , Marrone Alessandro , Pratesi Alessandro , Marzo Tiziano , La Mendola Diego
Published: July 2022

Ammonium trichloro (dioxoethylene-O,O′) tellurate (AS101) is a potent immunomodulator prodrug that, in recent years, entered various clinical trials and was tested for a variety of potential therapeutic applications. It has been demonstrated that AS101 quickly activates in aqueous milieu, producing TeOCl3−, which likely represents the pharmacologically active species. Here we report on the study of the activation process of AS101 and of two its analogues. After the synthesis and characterization of AS101 and its derivatives, we have carried out a comparative study through a combined experimental and computational analysis. Based on the obtained results, we describe here, for the first time, the detailed reaction that AS101 and its bromido- and iodido-replaced analogues undergo in presence of water, allowing the conversion of the original molecule to the likely true pharmacophore. Interestingly, moving down in the halogens’ group we observed a higher tendency to react, attributable to the ligands’ effect. The chemical and mechanistic implications of these meaningful differences are discussed.
Integrative Analyses of Transcriptomes to Explore Common Molecular Effects of Antipsychotic Drugs
Authors: Truong Trang T. T. , Bortolasci Chiara C. , Kidnapillai Srisaiyini , Spolding Briana , Panizzutti Bruna , Liu Zoe S. J. , Kim Jee Hyun , Dean Olivia M. , Richardson Mark F. , Berk Michael , Walder Ken
Published: July 2022

There is little understanding of the underlying molecular mechanism(s) involved in the clinical efficacy of antipsychotics for schizophrenia. This study integrated schizophrenia-associated transcriptional perturbations with antipsychotic-induced gene expression profiles to detect potentially relevant therapeutic targets shared by multiple antipsychotics. Human neuronal-like cells (NT2-N) were treated for 24 h with one of the following antipsychotic drugs: amisulpride, aripiprazole, clozapine, risperidone, or vehicle controls. Drug-induced gene expression patterns were compared to schizophrenia-associated transcriptional data in post-mortem brain tissues. Genes regulated by each of four antipsychotic drugs in the reverse direction to schizophrenia were identified as potential therapeutic-relevant genes. A total of 886 genes were reversely expressed between at least one drug treatment (versus vehicle) and schizophrenia (versus healthy control), in which 218 genes were commonly regulated by all four antipsychotic drugs. The most enriched biological pathways include Wnt signaling and action potential regulation. The protein-protein interaction (PPI) networks found two main clusters having schizophrenia expression quantitative trait loci (eQTL) genes such as PDCD10, ANK2, and AKT3, suggesting further investigation on these genes as potential novel treatment targets.
Intelligent Video Surveillance Systems for Vehicle Identification Based on Multinet Architecture
Authors: González-Cepeda Jacobo , Ramajo Álvaro , Armingol José María
Published: July 2022

Security cameras have been proven to be particularly useful in preventing and combating crime through identification tasks. Here, two areas can be mainly distinguished: person and vehicle identification. Automatic license plate readers are the most widely used tool for vehicle identification. Although these systems are very effective, they are not reliable enough in certain circumstances. For example, due to traffic jams, vehicle position or weather conditions, the sensors cannot capture an image of the entire license plate. However, there is still a lot of additional information in the image which may also be of interest, and that needs to be analysed quickly and accurately. The correct use of the processing mechanisms can significantly reduce analysis time, increasing the efficiency of video cameras significantly. To solve this problem, we have designed a solution based on two technologies: license plate recognition and vehicle re-identification. For its development and testing, we have also created several datasets recreating a real environment. In addition, during this article, it is also possible to read about some of the main artificial intelligence techniques for these technologies, as they have served as the starting point for this research.
Parasitoids and Predators of the Invasive Aphid Melanaphis sorghi Found in Sorghum and Non-Crop Vegetation of the Sorghum Agroecosystem
Authors: Faris Ashleigh M. , Brewer Michael J. , Elliott Norman C.
Published: July 2022

Melanaphis sorghi (Theobald) (sorghum aphid), (=Melanaphis sacchari Zehntner) (Hemiptera: Aphididae), is an invasive pest of Sorghum bicolor (L.) in North America. Over 19 species of predators and parasitoids have been found to prey on M. sorghi. Natural enemies may reside in vegetation such as sorghum in cultivation (in-season) and persist after harvest (off-season), in Johnson grass (Sorghum halepense) (L.) and riparian areas consisting of shrubs and grasses, including Johnson grass. The objective was to assess the ability of these vegetation types to harbor M. sorghi natural enemies during and between annual grain sorghum production. Predator diversity was greatest in riparian vegetation in-season, with twelve species detected across seven families, and four orders of insects. Six lady beetle (Coleoptera: Coccinellidae) species were abundant in-season, and Cycloneda sanguinea (L.) persisted at relatively high abundance off-season. Parasitoid diversity was more limited (two primary parasitoids and one hyperparasitoid detected) with the primary parasitoids commonly detected. Aphelinus nigritus (Howard) (Hymenoptera: Aphelinidae), accounted for 85% and 57% of parasitoids in- and off-season, respectively. Aphelinus nigritus abundance was steady across the annual sorghum season in all vegetation types. Results from this study will inform land-management strategies on how diverse vegetations can play a role in the biological control of M. sorghi.
Predictors for Returning to Paid Work after Transient Ischemic Attack and Minor Ischemic Stroke
Authors: Wicht Corentin A. , Chavan Camille F. , Annoni Jean-Marie , Balmer Philippe , Aellen Jérôme , Humm Andrea M. , Crettaz von Roten Fabienne , Spierer Lucas , Medlin Friedrich
Published: July 2022

This study aims to determine which factors within the first week after a first-ever transient ischemic attack (TIA) or minor ischemic stroke (MIS) are associated with stroke survivors’ ability to return to either partial or full time paid external work (RTpW). In this single-center prospective cohort study, we recruited 88 patients with first-ever TIA or MIS (NIHSS ≤ 5). Bivariate analyses were conducted between patients that did (RTpW) or did not return to paid work (noRTpW) within 7 days after stroke onset and at 3-months follow-up. Then, we conducted multivariate logistic and negative binomial regression analyses assessing (i) which factors are associated with RTpW at 3 months (ii) the likelihood that patients would RTpW at 3 months and (iii) the number of months necessary to RTpW. Overall, 43.2% of the patients did not RTpW at 3 months. At 3-months follow-up, higher anxiety/depression and fatigue-related disabilities were associated with noRTpW. Multivariate analysis showed that higher NIHSS scores at onset and hyperlipidemia (LDL cholesterol > 2.6 mmol/L or statins at stroke onset) were associated with noRTpW at 3 months. Stroke severity and/or newly diagnosed hypercholesterolemia at stroke onset in TIA or MIS patients were associated with not returning to paid work at 3 months.
Evolution Characteristics, Eco-Environmental Response and Influencing Factors of Production-Living-Ecological Space in the Qinghai–Tibet Plateau
Authors: Zhang Shuaibing , Zhao Kaixu , Ji Shuoyang , Guo Yafang , Wu Fengqi , Liu Jingxian , Xie Fei
Published: July 2022

The Qinghai–Tibet Plateau (QTP) is a major “river source” and “ecological source” in China, as well as South Asia and Southeast Asia, and is a typical plateau region. Studying the evolution characteristics and ecological effects of the production-living-ecological space (PLES) of the QTP is of great practical significance and theoretical value for strengthening its ecological construction and environmental protection. Based on 30 m × 30 m land use/cover data of the QTP at five time-points of 1980, 1990, 2000, 2010, and 2020, this paper investigates the PLES evolution characteristics, transfer characteristics, eco-environmental response, and influencing factors of the eco-environmental quality index (EEQI) in the region of China of the QTP from 1980 to 2020 by land use transfer matrix, eco-environmental response model, hot spot analysis, and geographically weighted regression (GWR). The results show that: (1) from 1980 to 2020, the ecological space of the QTP decreased, while the production and living space saw an increase. The PLES pattern of the QTP showed a clear shift from 2000 to 2010, while there was no significant change from 1980 to 2000 and from 2010 to 2020. (2) From 1980 to 2020, the EEQI of the QTP decreased from 0.5634 in 1980 to 0.5038 in 2010, and then increased to 0.5044 in 2020, showing a changing trend of first decreasing and then increasing; the degradation of grassland ecological space to other ecological space was the main cause leading to ecological environment deterioration. (3) From 1980 to 2000, the EEQI was high in the midwestern and southeastern parts of the QTP, presenting a double-center distribution. From 2010 to 2020, the EEQI decreased in the western part, while the high value area in the eastern part increased significantly, obviously low in the west and high in the east. The spatial variation characteristics of hot and cold spots and EEQI are generally similar. (4) Natural ecological and socioeconomic factors have significant differences on the spatial distribution of EEQI in the QTP, and natural ecological factors are the main driving factors, with topographic relief having the strongest effect on EEQI as a natural ecological factor, and population density having the strongest effect as a socioeconomic factor.
Characterization and Biomechanical Study of a Novel Magnesium Potassium Phosphate Cement
Authors: Han Zhenchuan , Wang Bo , Ren Bowen , Liu Yihao , Zhang Nan , Wang Zheng , Liu Jianheng , Mao Keya
Published: July 2022

Magnesium potassium phosphate cement (MKPC) has attracted considerable attention as a bone regeneration material. However, there are only a few reports on its biomechanical properties. To evaluate the biomechanical properties of MKPC, we compared the mechanical parameters of pedicle screws enhanced with either MKPC or polymethyl methacrylate (PMMA) bone cement. The results show that the maximum pull-out force of the pedicle screws was 417.86 ± 55.57 and 444.43 ± 19.89 N after MKPC cement setting for 30 min and 12 h, respectively, which was better than that of the PMMA cement. In fatigue tests, the maximum pull-out force of the MKPC cement group was 435.20 ± 7.96 N, whereas that of the PMMA cement in the control group was 346.80 ± 7.66 N. Furthermore, the structural characterization analysis of the MKPC cement revealed that its microstructure after solidification was an irregular tightly packed crystal, which improved the mechanical strength of the cement. The maximum exothermic temperature of the MKPC reaction was 45.55 ± 1.35 °C, the coagulation time was 7.89 ± 0.37 min, and the compressive strength was 48.29 ± 4.76 MPa, all of which meet the requirements of clinical application. In addition, the MKPC cement did not significantly inhibit cell proliferation or increase apoptosis, thus indicating good biocompatibility. In summary, MKPC exhibited good biomechanical properties, high initial strength, good biocompatibility, and low exothermic reaction temperature, demonstrating an excellent application potential in the field of orthopedics.
An Analytical Approach for Predicting EHL Friction: Usefulness and Limitations
Authors: Echávarri Otero Javier , de la Guerra Ochoa Eduardo , Chacón Tanarro Enrique , Franco Martínez Francisco , Contreras Urgiles Rafael Wilmer
Published: July 2022

The article studies the friction coefficient in elastohydrodynamic lubrication (EHL) by means of analytically obtained equations for different contact geometries. The introduction of some simplifications allows for the simultaneous consideration of piezoviscous, pseudoplastic and thermal phenomena, resulting in complete and realistic models, which provide results in a quick and easy manner. The predictive potential of this analytical approach is analyzed by comparing the estimates of friction with full-EHL simulations and experimental data under different operating conditions. The results obtained allow us to discuss the influence of some assumptions taken into account and the scope of applicability of the models, in order to determine their usefulness and limitations.
Synthesis and Evaluation of Self-Assembling Properties of 3-(3,5-Difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium Iodides
Authors: Pikun Nadiia , Lacis Davis , Sobolev Arkadij , Rucins Martins , Plotniece Mara , Pajuste Karlis , Plotniece Aiva
Published: July 2022

A synthesis of 3-(3,5-difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodides with ethyl or nonyl ester groups at positions 3 and 5 was performed. Treatment of the corresponding 2’,6’-dimethyl-1’,4’-dihydro-[3,4’-bipyridine]-3’,5’-dicarboxylates with Selectfluor® followed by quaternization of pyridine moiety in the obtained dialkyl 2,4-diacetyl-2,4-difluoro-3-(pyridin-3-yl)pentanedioates with methyl iodide gave the desired 3-(3,5-difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodides. This type of compound would be useful as synthetic lipids for further development of the delivery systems. The obtained target compounds were fully characterized by 1H NMR, 19F NMR, 13C NMR, HRMS, IR and UV data. The estimation of self-assembling properties and characterization of the nanoparticles obtained by ethanol solution injection in an aqueous media were performed by dynamic light scattering (DLS) measurements. DLS measurement data showed that 3-(3,5-difluoro-3,5-bis((nonyloxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodide created liposomes with the average diameter of 300–400 nm and polydispersity index (PDI) value around 0.30–0.40, while 3-(3,5-difluoro-3,5-bis((ethyloxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodide formed a heterogeneous sample with PDI value 1, which was not prospective for delivery system development.
Tensile Modulus of Polymer Halloysite Nanotube Systems Containing Filler–Interphase Networks for Biomedical Requests
Authors: Zare Yasser , Rhee Kyong Yop , Park Soo-Jin
Published: July 2022

To date, there have been a limited number of studies modeling the tensile modulus in the polymer halloysite nanotube (HNT) systems before or after percolation onset. In this paper, an equation for a composite’s modulus post-percolation onset was developed for HNT-filled samples including the interphase and HNT network. The dispersed nanoparticles and adjoining interphase part were neglected, because they caused ineffective influences on the stiffness of the system after percolation onset. The developed model reflects the impacts of HNTs’ size, interphase depth, percolation onset and the volume shares and moduli of the HNT network and its adjacent interphase on the modulus of HNT-based systems. The impacts of issues on the nanocomposite modulus are defendable, confirming the effectiveness of the developed model. HNT length, interphase depth, HNT concentration, net modulus and net portion directly influenced the stiffness, while the HNT radius and percolation onset had inverse effects. Results show that there was a 142% improvement in the modulus of samples at an interphase depth of 40 nm. Moreover, the stiffness improved by 60% at a net modulus of 200 GPa, but it later exhibited a 180% enhancement at a net modulus of 1000 GPa. In addition, the experimental data for the modulus of numerous composites display fine agreement to the predictions, confirming the validity of the developed model.
Short Implants versus Longer Implants with Sinus Floor Elevation: A Systemic Review and Meta-Analysis of Randomized Controlled Trials with a Post-Loading Follow-Up Duration of 5 Years
Authors: Wang Miaozhen , Liu Feng , Ulm Christian , Shen Huidan , Rausch-Fan Xiaohui
Published: July 2022

This study compared the outcome of fixed prostheses supported by short implants (<8 mm) and longer implants (≥8 mm) with an elevated sinus floor after 5 years of follow-up. The literature searches were performed electronically and manually in PubMed, EMBASE, and Web of Science databases to identify relevant articles published from 1 January 2013 to 31 January 2020. We selected eligible studies using inclusion criteria and assessed their quality. From 1688 identified studies, five randomized controlled trials were included. Between the short implant group and the control group, the implant failure-related pooled risk ratio (RR) was 3.64 (p = 0.07). The RR for technical complications was 2.61 (p = 0.0002), favoring longer implants. Marginal peri-implant bone loss after 1 and 5 years of function showed statistically significant less bone loss at short implants (1 year: mean difference = 0.21 mm; p < 0.00001; 5 years: mean difference = 0.26 mm; p = 0.02). The implant failure and the biological failure of both groups were similar after 5 years of follow-up. Short implants could be an alternative to long implants with an elevated sinus floor for atrophic maxillae in aging populations. Studies with larger trials and longer periods of follow-up (10 years) remain essential.
Recent Progress on Regulating Strategies for the Strengthening and Toughening of High-Strength Aluminum Alloys
Authors: Zheng Jia , Pang Qiu , Hu Zhili , Sun Qian
Published: July 2022

Due to their high strength, high toughness, and corrosion resistance, high-strength aluminum alloys have attracted great scientific and technological attention in the fields of aerospace, navigation, high-speed railways, and automobiles. However, the fracture toughness and impact toughness of high-strength aluminum alloys decrease when their strength increases. In order to solve the above contradiction, there are currently three main control strategies: adjusting the alloying elements, developing new heat treatment processes, and using different deformation methods. This paper first analyzes the existing problems in the preparation of high-strength aluminum alloys, summarizes the strengthening and toughening mechanisms in high-strength aluminum alloys, and analyzes the feasibility of matching high-strength aluminum alloys in strength and toughness. Then, this paper summarizes the research progress towards adjusting the technology of high-strength aluminum alloys based on theoretical analysis and experimental verification, including the adjustment of process parameters and the resulting mechanical properties, as well as new ideas for research on high-strength aluminum alloys. Finally, the main unsolved problems, challenges, and future research directions for the strengthening and toughening of high-strength aluminum alloys are systematically emphasized. It is expected that this work could provide feasible new ideas for the development of high-strength and high-toughness aluminum alloys with high reliability and long service life.
Effect of Bi, Sb, and Ti on Microstructure and Mechanical Properties of SAC105 Alloys
Authors: Yang Tixin , Chen Youyang , You Kangdong , Dong Ziqiang , Jia Yandong , Wang Gang , Peng Jubo , Cai Shanshan , Luo Xiaobin , Liu Chen , Wang Jiajun
Published: July 2022

The Sn-Ag-Cu (SAC) solder alloys with a low Ag (Ag < 3 wt.%) content have attracted great attention owing to their low cost, increased ability in bulk compliance, and plastic energy dissipation. However, some of their mechanical properties are generally lower than the SAC alloys with a higher Ag content. Adding alloying elements is an effective approach for improving the mechanical properties of the SAC alloys. In this study, the effect of Bi, Sb, and Ti on Sn-1 wt.%Ag-0.5 wt.%Cu (SAC105) solder alloys was investigated. The SAC solders with four compositions: SAC105-1 wt.%Bi, SAC105-1 wt.%Sb, SAC105-1 wt.%Bi-1 wt.%Sb, SAC105-1 wt.%Bi-1 wt.%Sb-0.4 wt.%Ti were prepared. The microstructure and phase compositions were characterized using electron scanning microscopy, and X-ray diffraction. The thermal properties and wettability were also examined. Uniaxial tensile tests and nano-indentation tests were conducted to evaluate the mechanical properties. The results show that adding Bi or Sb could increase the strength of SAC105 alloys mainly due to the solid solution strengthening effect. The creep resistance of SAC105 alloys was also improved with the additions of Bi and Sb. The co-additions of Bi and Sb into SAC105 alloys exhibit an enhanced creep resistance than that calculated by the theoretical calculation. The further addition of Ti into SAC105-1Bi-1Sb alloys demonstrated a much-improved creep resistance, which could be attributed to the synergistic effects of both solid solution strengthening and the precipitation hardening effects.
Special Issue: Advanced Science and Technology of Polymer Matrix Nanomaterials
Authors: Xu Liguo , Zhou Jintang , Jiao Zibao , Liu Peijiang
Published: July 2022

Nanotechnology has witnessed an incredible resonance and a substantial number of new applications in various areas during the past three decades [...]
Grey Correlation Analysis of the Durability of Steel Fiber-Reinforced Concrete under Environmental Action
Authors: Ji Yongcheng , Xu Wenwen , Sun Yichen , Ma Yulong , He Qiulin , Xing Zhiqiang
Published: July 2022

The interface performance of steel fiber-reinforced concrete (SFRC) is a critical factor in determining mechanical properties and durability. The degradation of the concrete matrix and micro-structure interface is caused by environmental erosion, which shortens the service life of the structure design. Considering different volume contents of steel fiber (0%, 1%, 2%), the failure mechanism of SFRC under different environmental erosion conditions was studied through a laboratory test scheme. A total of six environmental factors are selected, including water, sodium chloride solution, sodium sulfate solution, dilute sulfuric acid solution, sodium hydroxide solution, and a freeze-thaw cycle. When subjected to different erosion concentrations and periods, micro-structure and axial bearing capacity deterioration laws are compared and analyzed. A durability equation related to fiber mixture ratio and strength is presented based on the experimental data and the numerical simulation method. The influence of different environments on steel fiber-reinforced concrete is analyzed, and the grey correlation degree of axial compressive strength is analyzed. The experimental results show that steel fiber can effectively improve the concrete axial bearing capacity, but different responses are observed under the various erosion conditions. A freeze-thaw cycle environment has the most significant impact on the axial compressive strength of concrete, followed by the sulfuric acid environment, and other environments have a weaker impact. The research results will provide a theoretical basis for predicting the performance deterioration of SFRC concerning other erosion conditions and periods.
Implementation of Horizontal Connections in the Course of Mathematics by Combining Pedagogical and Digital Technologies
Authors: Tolkacheva Elena , Ivanov Sergey , Pozdniakov Sergei
Published: July 2022

The study examines three experiments of implementing the “learning through teaching” approach combined with the development of digital technologies and explores the influence of these methods on the quality of education for undergraduate engineering students at an urban technical university in Russia. In the first experiment, small independent groups of students within the same cohort developed individual Java modules with the goal of creating an intelligent system to support solving problems using graphs. In the second experiment, each student peer-taught the topic of their choice to three other students and then administered an oral exam to these students to assess their understanding. In the third experiment, each participant selected a problem to develop a solution and recorded a video that explained this solution to other students. All recorded videos were made available to all students, and the combined collection consisted of 100 videos. During the final exam, students were randomly assigned one of these problems and had to present their solutions to the instructor. Analysis of the experiments demonstrated that integrating “learning through teaching” led to an increase in student interest in the discipline and an improvement in conceptual understanding, more so for students in the role of teacher than in the role of learner. Overall, combining pedagogical and digital technologies improved the quality of education for engineering students.
Monochromatic Edges in Complete Multipartite Hypergraphs
Authors: Kittipassorn Teeradej , Sirirojrattana Boonpipop
Published: July 2022

Consider the following problem. In a school with three classes containing n students each, given that their genders are unknown, find the minimum possible number of triples of same-gender students—not all of which are from the same class. Muaengwaeng asked this question and conjectured that the minimum scenario occurs when the classes are all boys, all girls and half-and-half. In this paper, we solve many generalizations of the problem including when the school has more than three classes, when triples are replaced by groups of larger sizes, when the classes are of different sizes, and when gender is replaced by other non-binary attributes.
Magnetic Impact on the Unsteady Separated Stagnation-Point Flow of Hybrid Nanofluid with Viscous Dissipation and Joule Heating
Authors: Zainal Nurul Amira , Nazar Roslinda , Naganthran Kohilavani , Pop Ioan
Published: July 2022

The behaviour of magnetic impact on the unsteady separated stagnation-point flow of hybrid nanofluid with the influence of viscous dissipation and Joule heating is investigated numerically in this study. A new mathematical hybrid nanofluid model is developed, and similarity solutions are obtained in the form of ordinary differential equations (ODEs). The bvp4c approach in MATLAB is used to determine the reduced ODEs’ estimated solutions. The influence of various physical parameters is scrutinised. The findings revealed that the skin friction coefficient increases with the increment of the nanoparticle volume fraction and the unsteadiness parameter. This observation is also applied to the heat transfer rate of the fluid. Additionally, the presence of the magnetic and acceleration parameter provides a significant result in the heat transfer performance. The addition of the Eckert number increased the temperature profile distribution, thereby spontaneously decreasing the heat transfer rate. The first solution is declared stable by the analysis of solution stability.
A Reverse Hardy–Hilbert’s Inequality Containing Multiple Parameters and One Partial Sum
Authors: Yang Bicheng , Wu Shanhe , Huang Xingshou
Published: July 2022

In this work, by introducing multiple parameters and utilizing the Euler–Maclaurin summation formula and Abel’s partial summation formula, we first establish a reverse Hardy–Hilbert’s inequality containing one partial sum as the terms of double series. Then, based on the newly proposed inequality, we characterize the equivalent conditions of the best possible constant factor associated with several parameters. At the end of the paper, we illustrate that more new inequalities can be generated from the special cases of the reverse Hardy–Hilbert’s inequality.
Multi-Step-Ahead Electricity Price Forecasting Based on Temporal Graph Convolutional Network
Authors: Su Haokun , Peng Xiangang , Liu Hanyu , Quan Huan , Wu Kaitong , Chen Zhiwen
Published: July 2022

Traditional electricity price forecasting tends to adopt time-domain forecasting methods based on time series, which fail to make full use of the regional information of the electricity market, and ignore the extra-territorial factors affecting electricity price within the region under cross-regional transmission conditions. In order to improve the accuracy of electricity price forecasting, this paper proposes a novel spatio-temporal prediction model, which is combined with the graph convolutional network (GCN) and the temporal convolutional network (TCN). First, the model automatically extracts the relationships between price areas through the graph construction module. Then, the mix-jump GCN is used to capture the spatial dependence, and the dilated splicing TCN is used to capture the temporal dependence and forecast electricity price for all price areas. The results show that the model outperforms other models in both one-step forecasting and multi-step forecasting, indicating that the model has superior performance in electricity price forecasting.
Modified Inertial Subgradient Extragradient Method with Regularization for Variational Inequality and Null Point Problems
Authors: Song Yanlai , Bazighifan Omar
Published: July 2022

The paper develops a modified inertial subgradient extragradient method to find a solution to the variational inequality problem over the set of common solutions to the variational inequality and null point problems. The proposed method adopts a nonmonotonic stepsize rule without any linesearch procedure. We describe how to incorporate the regularization technique and the subgradient extragradient method; then, we establish the strong convergence of the proposed method under some appropriate conditions. Several numerical experiments are also provided to verify the efficiency of the introduced method with respect to previous methods.
Automatic Speech Emotion Recognition of Younger School Age Children
Authors: Matveev Yuri , Matveev Anton , Frolova Olga , Lyakso Elena , Ruban Nersisson
Published: July 2022

This paper introduces the extended description of a database that contains emotional speech in the Russian language of younger school age (8–12-year-old) children and describes the results of validation of the database based on classical machine learning algorithms, such as Support Vector Machine (SVM) and Multi-Layer Perceptron (MLP). The validation is performed using standard procedures and scenarios of the validation similar to other well-known databases of children’s emotional acting speech. Performance evaluation of automatic multiclass recognition on four emotion classes “Neutral (Calm)—Joy—Sadness—Anger” shows the superiority of SVM performance and also MLP performance over the results of perceptual tests. Moreover, the results of automatic recognition on the test dataset which was used in the perceptual test are even better. These results prove that emotions in the database can be reliably recognized both by experts and automatically using classical machine learning algorithms such as SVM and MLP, which can be used as baselines for comparing emotion recognition systems based on more sophisticated modern machine learning methods and deep neural networks. The results also confirm that this database can be a valuable resource for researchers studying affective reactions in speech communication during child-computer interactions in the Russian language and can be used to develop various edutainment, health care, etc. applications.
Enhanced Corrosion Resistance and Biological Properties of Ultrafine-Grained Ti15Zr5Cu Alloy
Authors: Wang Hai , Gao Wenwei , Zhang Xiyue , Li Yi , Zhang Shuyuan , Ren Ling , Yang Ke
Published: July 2022

Titanium alloys are widely used in the biomedical field. To ensure their strength meets requirements in clinics, medical titanium alloys are generally alloyed with toxic Al and/or V elements, hence ensuring their long-term biological safety after implantation is a challenge. In our previous research, we developed an ultrafine-grained Ti15Zr5Cu alloy without toxic elements while its mechanical properties were at the same level with the most widely used Ti6Al4V alloy. In order to promote the clinical application of the ultrafine-grained Ti15Zr5Cu alloy, herein we have systematically studied the hot deformation behaviors of the material as well as evaluated its corrosion resistance and biological properties. Results showed that when the as-quenched Ti15Zr5Cu alloy deformed at 0.05 ≤ ε˙ ≤ 1, 730 °C ≤ T ≤ 750 °C, it not only possessed good workability but also can be converted into an equiaxed ultrafine-grained microstructure. Moreover, the material also exhibited better corrosion resistance, antibacterial properties and biocompatibility than the Ti15Zr alloy and the commercial pure Ti. The results of the present study help lay a foundation for the development of a new generation of medical titanium alloys.