bluuebunny/crossref_metadata_2025 huggingface dataset:
B-Cell Activating Factor Increases Related to Adiposity, Insulin Resistance, and Endothelial Dysfunction in Overweight and Obese Subjects
Authors: Sánchez Diana Carolina Villalpando , Castellanos Sergio Gutiérrez , Sandoval Martha Eva Viveros , García Anel Gómez
Published: April 2022

Obesity (OB) is a major healthcare problem that results from long-term energy imbalance. Adipokines and pro-inflammatory cytokines facilitate adipose tissue (AT) remodeling to safely store excess nutrients. B-cell activating factor (BAFF) is a newly described adipokine whose role in enhancing adipogenesis has been reported. The present study aimed to evaluate serum BAFF association with adiposity distribution, serum adipokines, pro-inflammatory cytokines, and metabolic and endothelial dysfunction markers. The study included 124 young Mexican adults with no diagnosed comorbidities, divided according to their BMI. Anthropometric measurements, blood counts, and serum molecules (i.e., glucose, lipid profile, insulin, leptin, pro- and anti-inflammatory cytokines, von Willebrand factor (vWF), and BAFF) were assessed. The analysis showed positive correlation between BAFF and increased fat mass in all anthropometric measurements (p < 0.0001). BAFF augmentation was related to systemic inflammatory environment (p < 0.05), and linked with insulin resistance status (p < 0.05). BAFF increment was also correlated with early endothelial damage markers such as vWF (p < 0.0001). Linear regression analysis showed a role for BAFF in predicting serum vWF concentrations (p < 0.01). In conclusion, our data show that BAFF is an adipokine dynamically related to OB progression, insulin resistance status, and systemic inflammatory environment, and is a predictor of soluble vWF augmentation, in young overweight and obese Mexican subjects.
Multi-Frequency Intraoperative Monitoring of Hearing Preservation during Cochlear Implantation
Authors: Skarżyński Piotr Henryk , Lorens Artur , Walkowiak Adam , Polak Marek , Skarżyński Henryk
Published: April 2022

(1) Background: Current indications for cochlear implants (CIs) have expanded to include patients with appreciable low-frequency hearing. However, longitudinal results indicate that only one-third of these recipients retain full hearing preservation. In another words, the remaining two-thirds lose this facility either partially or fully. This points to the need to better understand the impact of cochlear implantation on cochlear integrity. Intracochlear electrocochleography (ECochG) involves the recording of electrical potentials generated in the inner ear in response to acoustic stimuli, and previous studies have shown that these potentials give an indication of residual inner ear function. Aim of the research: The aim is to monitor intracochlear ECochG during CI surgery and gain a better understanding of how the implant impacted inner ear function. A newly developed SPL Chirp was used for stimulation. (2) Methods: Intracochlear ECochG signals were measured in a subject with residual preoperative low-frequency hearing, while an electrode array was introduced into the cochlea and was continued until the round window was sealed. Afterwards, surgical events were reviewed with the surgeon; preoperative and postoperative radiological data and hearing thresholds were also evaluated. (3) Conclusions: Real-time intraoperative monitoring, with multifrequency evaluation and video recording, has the potential to allow surgeons and audiologists to continuously assess cochlear function. ECochG monitoring may be a useful tool during cochlear implantation to gain frequency-specific information on the status of the patient’s hearing, assisting surgeons to lower hearing trauma during the operation.
Concerns with Male Infertility Induced by Exposure to Titanium Nanoparticles and the Supporting Impact of Pelargonium graveolens Essential Oil: Morphometric Records in Male-Wistar Rats
Authors: Said Ahmed Abdou , Nasr Yasmin , Galal Azza A. A. , Abdelhamid Ahmed E. , Mohamed Haiam A. , Metwally Mohamed M. M. , Said Mahmoud A. , Nassan Mohamed A. , Dahran Naief , Mohamed Amany Abdel-Rahman
Published: April 2022

Background: Due to the increased use of titanium dioxide nanoparticles (TiO2 NPs), the risks of their reprotoxic effect arise. This study anticipated examining the potential protective effects of GEO (geranium essential oil) components screened via GC/MS analysis against the reprotoxic impacts of TiO2 NPs on male rats. Methods: Thirty-two adult male rats were randomly assigned to four groups: control, GEO (75 mg/kg bwt/orally/day/60 days), TiO2 NPs (100 ppm/rat/IP/day/60 days), and TiO2 NPs + GEO. After 60 days, hormonal assay, semen appraisal, lipid peroxidation, antioxidant enzymes, testis and prostate morphometry, and the steroidogenesis-related genes’ mRNA expressions were assessed. Results: The TEM and DLS results demonstrated that synthesized TiO2 NPs are spherical with minimal aggregations polydispersed and varying in size from 50 to 100 nm. TiO2 NPs IP injection-induced sperm abnormalities decreased the percent of motile sperms in the sperm count, reduced sex hormone levels, altered the testicular oxidant/antioxidant status and mRNA expression of steroid-related genes, and induced architectural alterations in testicular, epididymal, and prostate gland tissues. GEO significantly rescued the TiO2 NPs-altered spermiogram, sex hormones, and antioxidant capacity, restored the tissue architectures, and enhanced steroidogenesis-related gene mRNA expression. Conclusions: These findings may significantly contribute to developing combinatorial treatments for infertility associated with various environmental and industrial xenobiotic exposures.
Modulation by Estradiol of L-Dopa-Induced Dyskinesia in a Rat Model of Post-Menopausal Hemiparkinsonism
Authors: Kolmančič Kaja , Živin Marko , Zorović Maja
Published: April 2022

Treatment with levodopa (L-dopa) in Parkinson’s disease (PD) leads to involuntary movements termed L-dopa-induced dyskinesia (LID). There are contradictory data about the influence of hormone therapy in female PD patients with LID and of 17-β-estradiol (E2) on animal correlates of LID-abnormal involuntary movements (AIMs). Our aim was to characterize the influence of E2 on motor impairment and AIMs in ovariectomized 6-hydroxydopamine (6-OHDA) rat model of PD. Half of the rats received empty and the other half implants filled with E2. Following the 6-OHDA surgery, the rats received daily treatment with either L-dopa or saline for 16 days. They were assessed for AIMs, contralateral rotations, and FAS. In the L-dopa-treated rats, E2 intensified and prolonged AIMs and contralateral rotations. On the other hand, it had no effect on motor impairment. Postmortem tyrosine hydroxylase immunostaining revealed an almost complete unilateral lesion of nigrostriatal dopaminergic neurons. E2 partially prevented the upregulation of striatal ΔFosB caused by dopamine depletion. L-dopa potentiated the upregulation of ΔFosB within the dopamine-depleted striatum and this effect was further enhanced by E2. We speculate that the potentiating effects of E2 on AIMs and on contralateral rotations could be explained by the molecular adaptations within the striatal medium spiny neurons of the direct and indirect striatofugal pathways.
Reduced Recurrence Rates Are Associated with Photodynamic Diagnostics Compared to White Light after Extended Transurethral Resection of Bladder Tumors
Authors: Marquardt Alexander , Richterstetter Mario , Taubert Helge , Hartmann Arndt , Wullich Bernd , Lieb Verena , Bellut Laura , Wach Sven , Apel Hendrik
Published: April 2022

One pillar in treating non-muscle-invasive bladder cancer (NMIBC) is the complete and high-quality transurethral resection of the primary tumor (TURBT). However, even after a high-quality primary resection, the residual tumor risk is considerable, thus requiring a re-TURBT. Resections performed with the aid of a photodynamic diagnostics report improved recurrence-free survival rates and increased detection rates of carcinoma in situ (CIS). This monocentric retrospective study reports on patients treated with an extended TURBT procedure using conventional white-light cystoscopy or photodynamic diagnostics (PDD). Only patients undergoing a TURBT resection for their primary tumor were included in the statistical analysis. Recurrence-free survival and overall survival were the clinical endpoints. Mann–Whitney U tests and chi-squared tests were used for descriptive intergroup comparisons. The associations with overall survival and recurrence-free survival were determined by univariate and multivariate analyses. The test results were considered significant when p was < 0.05. In comparison to conventional white-light cystoscopy, PDD increased the detection rates of CIS (p = 0.004) and tumor multifocality (p = 0.005) and led to reduced residual tumor incidence at the primary resection site (p < 0.001). Likewise, tumor recurrence rates were reduced in the PDD cohort (p < 0.001). Patient age and the presence of residual tumor at the primary resection site were identified as independent predictors of overall survival. For recurrence-free survival, only the PDD resection method was an independent predictor (HR = 0.43; p < 0.001). In summary, we demonstrated that the utilization of PDD techniques was associated with improved detection rates of CIS and multifocal tumors and with reduced recurrence rates. The extended resection protocol allowed us to determine that PDD resections lead to a reduced residual tumor rate at the initial resection site. This residual tumor state at the resection site, determined by extended TURBT, became an independent predictor of long-term survival. On the other hand, the PDD technique was confirmed as the only independent predictor of recurrence-free survival.
Chronic Exposure to the Food Additive tBHQ Modulates Expression of Genes Related to SARS-CoV-2 and Influenza Viruses
Authors: Németh Krisztina , Petschner Peter , Pálóczi Krisztina , Fekete Nóra , Pállinger Éva , Buzás Edit I. , Tamási Viola
Published: April 2022

Background. tert-butylhydroquinone (tBHQ) is an antioxidant commonly used as a food additive. Studies suggest that tBHQ could modulate immune responses to influenza and SARS-CoV-2 infection. In our transcriptomic analysis we explored the molecular mechanisms behind tBHQ’s modulatory properties and the relationships to respiratory viral infections. Methods. tBHQ was administered per os to BALB/c mice (1.5% [w/w]) for 20 days. Splenic T cells were isolated with magnetic separation and subjected to transcriptomic analysis. Gene-set enrichment analysis and g:Profiler was conducted to provide a functional interpretation of significantly changed genes. Further analysis for AHR/NRF2 binding sites was performed with GeneHancer. Results. In CD4+ cells, we found significantly altered expression of 269 genes by tBHQ. Of them, many had relevance in influenza infection such as genes responsible for virus entry (Anxa1/2, Cd14), interferon signaling (Dusp10, Tnfsf13), or prostaglandin synthesis (Ptgs1/2). In SARS-CoV-2 infections, interferon signaling (Ifitm1), proteolytic enzymes (CtsB), and also cell-surface proteins (Cd14, Cd151) were among the prominent alterations after tBHQ exposure. Of these genes, many had one or more binding sites for AHR and NRF2, two major xenosensors triggered by tBHQ. Conclusions. Our results strongly suggest that a common food additive, tBHQ, can modulate virus-dependent processes in both influenza and SARS-CoV-2 infections.
The Influence of Sex, Gender, and Age on COVID-19 Data in the Piedmont Region (Northwest Italy): The Virus Prefers Men
Authors: De Francia Silvia , Ferretti Alessandro , Chiara Francesco , Allegra Sarah , Mancardi Daniele , Allice Tiziano Giacomo , Milia Maria Grazia , Gregori Gabriella , Burdino Elisa , Avanzini Claudio , Ghisetti Valeria , Durio Alessandra
Published: April 2022

Several important sex and gender differences in the clinical manifestation of diseases have been known for a long time but are still underestimated. The infectious Coronavirus 2019 disease pandemic has provided evidence of the importance of a sex and gender-based approach; it mainly affected men with worse symptomatology due to a different immune system, which is stronger in women, and to the Angiotensin-converting enzyme 2 and Transmembrane protease serine 2 roles which are differently expressed among the sexes. Additionally, women are more inclined to maintain social distance and smoke less. Analysis of data on the infectious Coronavirus 2019 disease testing from people admitted to the Amedeo di Savoia Hospital, a regional referral center for infectious diseases, has been applied to the whole of 2020 data (254,640 records). A high percentage of data in the dataset was not suitable due to a lack of information or entering errors. Among the suitable samples, records have been analyzed for positive/negative outcomes, matching records for unique subjects (N = 123,542), to evaluate individual recurrence of testing. Data are presented in age and sex-disaggregated ways. Analyses of the suitable sample also concerned the relation between testing and hospital admission motivation and symptoms. Our analysis indicated that a sex and gender-based approach is mandatory for patients and the National Health System’s sustainability.
Manipulation of Insect Vectors’ Host Selection Behavior by Barley Yellow Dwarf Virus Is Dependent on the Host Plant Species and Viral Co-Infection
Authors: Minato Nami , Hatori Shuichi , Okawa Azusa , Nakagawa Kai , Hironaka Mantaro
Published: April 2022

Previous studies have shown that vector-borne viruses can manipulate the host selection behavior of insect vectors, yet the tripartite interactions of pathogens, host plants and insect vectors have been documented only in a limited number of pathosystems. Here, we report that the host selection behavior of the insect vector of barley yellow dwarf virus-PAV (BYDV-PAV) and cereal yellow dwarf virus-RPS (CYDV-RPS) is dependent on the host plant species and viral co-infection. This study shows that a model cereal plant, Brachypodium distachyon, is a suitable host plant for examining tripartite interactions with BYDV-PAV and CYDV-RPS. We reveal that BYDV-PAV has a different effect on the host selection behavior of its insect vector depending on the host plant species. Viruliferous aphids significantly prefer non-infected plants to virus-infected wheat plants, whereas viral infection on a novel host plant, B. distachyon, is not implicated in the attraction of either viruliferous or nonviruliferous aphids. Furthermore, our findings show that multiple virus infections of wheat with BYDV-PAV and CYDV-RPS alter the preference of their vector aphid. This result indicates that BYDV-PAV acquisition alters the insect vector’s host selection, thereby varying the spread of multiple viruses.
The Influence of Shot Peening and Artificially Ageing Aluminium Alloy 7075 on Corrosion Behaviour
Authors: Žagar Sebastjan , Mrvar Primož , Grum Janez , Šturm Roman
Published: April 2022

This paper investigates the corrosion of shot peened AA7075 aluminium alloys aged at different temperatures. The surface integrity of the hardened layer was evaluated with SEM, EDS, differential scanning calorimetry, hardness, and roughness measurements, and in the end also with corrosion resistance tests. The research results indicated that there were significant differences in precipitates distribution between aluminium alloys artificially aged at different temperatures. As the ageing temperature increases, the microhardness decreases, which influences the final roughness condition of the surface layer after shot peening. The results of potentiodynamic polarisation tests indicate that shot peening enables shifting the pitting potential to positive values, which ensures slightly higher corrosion resistance. SEM images confirmed the dissolution of the aluminium matrix near the separated iron-rich phases of the Alx form (Fe, Mn) by the action of galvanic cells.
Solar-Driven Syngas Production Using Al-Doped ZnTe Nanorod Photocathodes
Authors: Jang Youn Jeong , Lee Chohee , Moon Yong Hyun , Choe Seokwoo
Published: April 2022

Syngas, traditionally produced from fossil fuels and natural gases at high temperatures and pressures, is an essential precursor for chemicals utilized in industry. Solar-driven syngas production can provide an ideal pathway for reducing energy consumption through simultaneous photoelectrochemical CO2 and water reduction at ambient temperatures and pressures. This study performs photoelectrochemical syngas production using highly developed Al-doped ZnTe nanorod photocathodes (Al:ZnTe), prepared via an all-solution process. The facile photo-generated electrons are transferred by substitutional Al doping on Zn sites in one-dimensional arrays to increase the photocurrent density to −1.1 mA/cm2 at −0.11 VRHE, which is 3.5 times higher than that for the pristine ZnTe. The Al:ZnTe produces a minor CO (FE ≈ 12%) product by CO2 reduction and a major product of H2 (FE ≈ 60%) by water reduction at −0.11 VRHE. Furthermore, the product distribution is perfectly switched by simple modification of Au deposition on photocathodes. The Au coupled Al:ZnTe exhibits dominant CO production (FE ≈ 60%), suppressing H2 evolution (FE ≈ 15%). The strategies developed in this study, nanostructuring, doping, and surface modification of photoelectrodes, can be applied to drive significant developments in solar-driven fuel production.
Nanofunctionalization of Additively Manufactured Titanium Substrates for Surface-Enhanced Raman Spectroscopy Measurements
Authors: Pisarek Marcin , Ambroziak Robert , Hołdyński Marcin , Roguska Agata , Majchrowicz Anna , Wysocki Bartłomiej , Kudelski Andrzej
Published: April 2022

Powder bed fusion using a laser beam (PBF-LB) is a commonly used additive manufacturing (3D printing) process for the fabrication of various parts from pure metals and their alloys. This work shows for the first time the possibility of using PBF-LB technology for the production of 3D titanium substrates (Ti 3D) for surface-enhanced Raman scattering (SERS) measurements. Thanks to the specific development of the 3D titanium surface and its nanoscale modification by the formation of TiO2 nanotubes with a diameter of ~80 nm by the anodic oxidation process, very efficient SERS substrates were obtained after deposition of silver nanoparticles (0.02 mg/cm2, magnetron sputtering). The average SERS enhancement factor equal to 1.26 × 106 was determined for pyridine (0.05 M + 0.1 M KCl), as a model adsorbate. The estimated enhancement factor is comparable with the data in the literature, and the substrate produced in this way is characterized by the high stability and repeatability of SERS measurements. The combination of the use of a printed metal substrate with nanofunctionalization opens a new path in the design of SERS substrates for applications in analytical chemistry. Methods such as SEM scanning microscopy, photoelectron spectroscopy (XPS) and X-ray diffraction analysis (XRD) were used to determine the morphology, structure and chemical composition of the fabricated materials.
Effect of Current Density on the Microstructure and Mechanical Properties of 3YSZ/Al2O3 Composites by Flash Sintering
Authors: Bai Yujie , Zhang Ying , Tian Zhifeng , Zhang Junzhan , Shi Zongmo
Published: April 2022

The 3YSZ/40 wt% Al2O3 composites were prepared by flash sintering at a low furnace temperature (700 °C). The effects of the current density on the relative density and Vickers hardness of the composites were systematically investigated. The results showed that the relative densities and Vickers hardness of the samples increased gradually with the increasing of the current densities, and the relative density was as high as 94.2%. The Vickers hardness of 11.3 GPa was obtained under a current density of 102 mA/mm2. Joule heating and defects generation are suggested to be the main causes of rapid densification in flash sintering. The microstructure of the molten zone showed the formation of eutectic structures in the composite, suggesting that grain boundary overheating may have contributed to the formation of the molten zone.
Argon Ion Beam Current Dependence of Si-Si Surface Activated Bonding
Authors: Yang Song , Deng Ningkang , Qu Yongfeng , Wang Kang , Yuan Yuan , Hu Wenbo , Wu Shengli , Wang Hongxing
Published: April 2022

In order to optimize the process parameters of Si-Si wafer direct bonding at room temperature, Si-Si surface activated bonding (SAB) was performed, and the effect of the argon ion beam current for surface activation treatment on the Si-Si bonding quality was investigated. For the surface activation under the argon ion beam irradiation for 300 s, a smaller ion beam current (10~30 mA) helped to realize a lower percentage of area covered by voids and higher bonding strength. Especially with the surface activation under 30 mA, the bonded Si-Si specimen obtained the highest bonding quality, and its percentage of area covered by voids and bonding strength reached <0.2% and >7.62 MPa, respectively. The transmission electron microscopy analyses indicate that there exists an ultrathin amorphous Si interlayer at the Si-Si bonding interface induced by argon ion beam irradiation to Si wafer surfaces, and its thickness increases as the argon ion beam current rises. The investigation results can be used to optimize the SAB process and promote the applications of SAB in the field of semiconductor devices.
XPS Study on Calcining Mixtures of Brucite with Titania
Authors: Sánchez-Zambrano Karla Sofía , Hernández-Reséndiz Marina , Gómez-Rodríguez Cristian , García-Quiñonez Linda Viviana , Aguilar-Martínez Josué Amilcar , Rodríguez-Castellanos Edén Amaral , Verdeja Luis Felipe , Fernández-González Daniel , Castillo-Rodríguez Guadalupe Alan
Published: April 2022

In this work, we studied the phases in a Mg-Ti-O system using a 1:1 formulation of MgO:TiO2, mixing synthetic brucite of Mexican origin with TiO2 microparticles of high purity, with a heat treatment at 1100 °C for 1 h. Due to its valence electrons, TiO2 can contribute to the sintering process to improve density in MgO products. The raw materials and formulation by XPS and X-RD techniques were characterized. The results demonstrate the presence of different oxidation states in titania and the formation of different oxides in the Mg-Ti-O system when mixed and calcined at 1100 °C; additionally, we estimated the formation of vacancies in the crystal lattice during the transformation from hexagonal brucite to magnesia with a cubic structure centered on the faces. Its thermal behavior is indicated by the MgO-TiO2 phase diagram.
Multifunctional Cu2SnS3 Nanoparticles with Enhanced Photocatalytic Dye Degradation and Antibacterial Activity
Authors: Shelke Harshad D. , Machale Archana R. , Survase Avinash A. , Pathan Habib M. , Lokhande Chandrakant D. , Lokhande Abhishek C. , Shaikh Shoyebmohamad F. , Rana Abu ul Hassan S. , Palaniswami Marimuthu
Published: April 2022

We present a simplistic, ultrafast, and facile hydrothermal deposition of ternary Cu2SnS3 nanoparticles (CTS NPs). The fabricated CTS NPs show superior antimicrobial and photocatalytic activities. In the presence of UV-Visible illumination, methylene blue (MB) dye was studied for photocatalytic dye degradation activity of CTS NPs. Excellent efficiency is shown by incorporating CTS NPs to degrade MB dye. There is a ~95% decrease in the absorbance peak of the dye solution within 120 min. Similarly, CTS NPs tested against three bacterial strains, i.e., B. subtilis, S. aureus, P. vulgaris, and one fungal strain C. albicans, defining the lowest inhibitory concentration and zone of inhibition, revealed greater antimicrobial activity. Hence, it is concluded that the CTS NPs are photocatalytically and antimicrobially active and have potential in biomedicine.
Lattice Dynamics, Mechanical Properties, Electronic Structure and Magnetic Properties of Equiatomic Quaternary Heusler Alloys CrTiCoZ (Z = Al, Si) Using First Principles Calculations
Authors: Andharia Eesha , Alqurashi Hind , Hamad Bothina
Published: April 2022

First principles calculations are performed to investigate the thermodynamical stability, dynamical, mechanical, electronic and magnetic properties of CrTiCoZ (Z = Al/Si) novel quaternary Heusler alloys. A Y-type III atomic configuration is found to be the most stable structure for both compounds. The lattice constant values obtained using GGA-PBE approach are 5.9368 Å and 5.7853 Å for CrTiCoAl and CrTiCoSi, respectively. Using the value of elastic moduli for both the compounds, the computed Pugh’s ratio value is 2.5 and 2.7 for CrTiCoAl and CrTiCoSi, respectively, which is higher than 1.75, indicating both the compounds are ductile in nature. The melting temperatures of both compounds are as high as 2142 K and 2420 K for CrTiCoAl and CrTiCoSi, respectively. The electronic structure calculations, using the GGA-PBE approach, show a half metallic behavior of CrTiCoAl. The spin-down channel exhibits a direct band gap of 0.15 eV, whereas the spin-up channel is metallic, making CrTiCoAl a half metallic ferromagnet with 100% spin polarization and an appreciable magnetic moment of −2 μB. However, CrTiCoSi is found to be semi-metallic in the spin-down channel and metallic in the spin-up channel, which leads to a spin polarization of 99.7% with a non-integer magnetic moment of −0.99 μB. The Curie temperature of CrTiCoAl is well above the room temperature (385 K), whereas that of CrTiCoSi is below the room temperature (203 K). Thus, CrTiCoAl is found to be more promising than CrTiCoSi as a spin injector in spintronic devices.
Effect of Parylene C on the Corrosion Resistance of Bioresorbable Cardiovascular Stents Made of Magnesium Alloy ‘Original ZM10’
Authors: Sasaki Makoto , Xu Wei , Koga Yuki , Okazawa Yuki , Wada Akira , Shimizu Ichiro , Niidome Takuro
Published: April 2022

Magnesium (Mg) alloy has attracted significant attention as a bioresorbable scaffold for use as a next-generation stent because of its mechanical properties and biocompatibility. However, Mg alloy quickly degrades in the physiological environment. In this study, we investigated whether applying a parylene C coating can improve the corrosion resistance of a Mg alloy stent, which is made of ‘Original ZM10’, free of aluminum and rare earth elements. The coating exhibited a smooth surface with no large cracks, even after balloon expansion of the stent, and improved the corrosion resistance of the stent in cell culture medium. In particular, the parylene C coating of a hydrofluoric acid-treated Mg alloy stent led to excellent corrosion resistance. In addition, the parylene C coating did not affect a polymer layer consisting of poly(ε-caprolactone) and poly(D,L-lactic acid) applied as an additional coating for the drug release to suppress restenosis. Parylene C is a promising surface coating for bioresorbable Mg alloy stents for clinical applications.
Analysis of Selected Properties of Microporous PLA as a Result of Abiotic Degradation
Authors: Tor-Świątek Aneta , Garbacz Tomasz , Stloukal Petr
Published: April 2022

In the study, an investigation was made into the hydrolytic degradation behavior of the microporous polylactide (PLA) in the initial stage in three biological buffer solutions with various pH-simulating body fluids in comparison with pure PLA. Studies also include the analysis of selected mechanical properties and physical structures. A microporous PLA was obtained by melt extrusion using a chemical blowing agent. The rate of Mw decrease induced by hydrolysis over 35 days of microporous PLA was roughly comparable to the pure material. The rate of depolymerization was slightly accelerated at an acid pH due to acid-catalyzed hydrolysis at the end of the observed period. The mechanical analysis showed the influence of various pH on the obtained results.
Engineered Chimeric Peptides with IGF-1 and Titanium-Binding Functions to Enhance Osteogenic Differentiation In Vitro under T2DM Condition
Authors: Wang Jun-Jun , Xue Qian , Wang Ying-Jie , Zhang Min , Chen Yong-Jin , Zhang Qian
Published: April 2022

Due to the complexity of the biomolecules and titanium (Ti) combination, it is a challenge to modify the implant surface with biological cytokines. The study proposed a new method for immobilizing cytokines on implant surface to solve the problem of low osseointegration under type 2 diabetes mellitus (T2DM) condition. This new modified protein that connected Ti-binding artificial aptamer minTBP-1 with Insulin-like growth factor I (IGF-I), had a special strong affinity with Ti and a therapeutic effect on diabetic bone loss. According to the copies of minTBP-1, three proteins were prepared, namely minTBP-1-IGF-1, 2minTBP-1-IGF-1 and 3minTBP-1-IGF-1. Compared with the other modified proteins, 3minTBP-1-IGF-1 adsorbed most on the Ti surface. Additionally, this biointerface demonstrated the most uniform state and the strongest hydrophilicity. In vitro results showed that the 3minTBP-1-IGF-1 significantly increased the adhesion, proliferation, and mineralization activity of osteoblasts under T2DM conditions when compared with the control group and the other modified IGF-1s groups. Real-time PCR assay results confirmed that 3minTBP-1-IGF-1 could effectively promote the expression of osteogenic genes, that is, ALP, BMP-2, OCN, OPG, and Runx2. All these data indicated that the 3minTBP-1-IGF-1 had the most efficacious effect in promoting osteoblasts osteogenesis in diabetic conditions, and may be a promising option for further clinical use.
Mechanical and Microstructural Characterization of Rammed Earth Stabilized with Five Biopolymers
Authors: Losini Alessia Emanuela , Grillet Anne-Cecile , Woloszyn Monika , Lavrik Liudmila , Moletti Chiara , Dotelli Giovanni , Caruso Marco
Published: April 2022

This study aims to check the compatibility of a selection of waste and recycled biopolymers for rammed earth applications in order to replace the more common cement-based stabilization. Five formulations of stabilized rammed earth were prepared with different biopolymers: lignin sulfonate, tannin, sheep wool fibers, citrus pomace and grape-seed flour. The microstructure of the different formulations was characterized by investigating the interactions between earth and stabilizers through mercury intrusion porosimetry (MIP), nitrogen soprtion isotherm, powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). The unconfined compressive strength (UCS) was also evaluated for all stabilized specimens. Three out of five biopolymers were considered suitable as rammed earth stabilizers. The use of wool increased the UCS by 6%, probably thanks to the combined effect of the length of the fibers and the roughness of their surfaces, which gives a contribution in binding clay particles higher than citrus and grape-seed flour. Lignin sulfonate and tannin increased the UCS by 38% and 13%, respectively, suggesting the additives’ ability to fill pores, coat soil grains and form aggregates; this capability is confirmed by the reduction in the specific surface area and the pore volume in the nano- and micropore zones.
Optical and Photosensitive Properties of Flexible n (p)–InSe/In2O3 Heterojunctions
Authors: Sprincean Veaceslav , Leontie Liviu , Caraman Iuliana , Untila Dumitru , Girtan Mihaela , Gurlui Silviu , Lisnic Petru , Doroftei Corneliu , Carlescu Aurelian , Iacomi Felicia , Caraman Mihail
Published: April 2022

In this work, optical, including photoluminescence and photosensitivity, characteristics of micrometer-sized flexible n (p)–InSe/In2O3 heterojunctions, obtained by heat treatment of single-crystalline InSe plates doped with (0.5 at.%) Cd (Sn), in a water-vapor- and oxygen-enriched atmosphere, are investigated. The Raman spectrum of In2O3 layers on an InSe:Sn substrate, in the wavelength range of 105–700 cm−1, contains the vibration band characteristic of the cubic (bcc-In2O3) phase. As revealed by EDX spectra, the In2O3 layer, ~2 μm thick, formed on InSe:Cd contains an ~18% excess of atomic oxygen. The absorption edge of InSe:Sn (Cd)/In2O3 structures was studied by ultraviolet reflectance spectroscopy and found to be 3.57 eV and ~3.67 eV for InSe:Cd and InSe:Sn substrates, respectively. By photoluminescence analysis, the influence of doping impurities on the emission bands of In2O3:Sn (Cd) was revealed and the energies of dopant-induced and oxygen-induced levels created by diffusion into the InSe layer from the InSe/In2O3 interface were determined. The n (p)–InSe/In2O3 structures display a significantly wide spectral range of photosensitivity (1.2–4.0 eV), from ultraviolet to near infrared. The influence of Cd and Sn concentrations on the photosensitivity and recombination of nonequilibrium charge carriers in n (p)–InSe layers from the heterojunction interface was also studied. The as-obtained nanosized InSe/In2O3 structures are suitable for optoelectronic applications.
Design and Control of a Hydraulic Hexapod Robot with a Two-Stage Supply Pressure Hydraulic System
Authors: Liu Ziqi , Jin Bo , Dong Junkui , Zhai Shuo , Tang Xuan
Published: April 2022

This paper focuses on the system design and control strategies of a hydraulic hexapod robot (HHR) ZJUHEX01 with a two-stage supply pressure hydraulic system (TSS). Firstly, a brief introduction is given, including the mechanical structure, the onboard hydraulic system, and the control system architecture. Secondly, the kinematics model and hydraulic system model are built in preparation for the controller design. Then a sliding mode repetitive controller (SMRC) for the separate meter in and separate meter out (SMISMO) hydraulic system is proposed, as well as the valve configuration, to help HHR get better control performance and smaller tracking errors. Furthermore, a high order sliding mode differentiator (HOSMD) is developed to obtain the joint angular velocity and acceleration. Finally, the ADAMS and MATLAB/Simulink co-simulation model is established to verify the effectiveness of the control strategy. Also, the energy consumption of TSS is compared with that of one-stage supply pressure hydraulic system (OSS) to show a great energy-saving effect of 51.94%.
Buffering Performance Analysis of an Ostrich-like Leg Based on a Seven-Link Parallel Mechanism
Authors: Nie Daming , Du Ruilong , Tian Jiangren , Zhang Pu , Shen Fangyan , Gu Jason , Fu Yili
Published: April 2022

As one of the fastest running animals on land, the ostrich’s excellent athletic ability benefits from its unique leg structure. Based on the idea of bionics, this paper intends to obtain a kind of robotic leg structure with a similar buffering capacity to that of the ostrich. For this purpose, the structural characteristics of a seven-link parallel mechanism are analyzed firstly, having some specific features similar to ostrich legs, such as the center of mass (COM) located at the root of the leg, a large folding/unfolding ratio, and so on. Then, the kinematic model of the bionic leg is established, and the energy storage of the flexible parts of the leg is investigated. Finally, an impact experiment of the structure onto the ground is carried out to verify the accuracy of the established kinematic model. This paper systematically reveals the nonlinear law of the elasticity of an ostrich-like leg and provides the buffering performance characteristics of the leg in the process of hitting the ground, based on its elastic properties by the kinematic model and the experiment.
Experimental Study on the Response of Hand-Transmitted Vibration from an EVA Power Tool
Authors: Fu Hao , Jin Minghe , Yu Yang , Chen Yang , Zheng Peng
Published: April 2022

The objective of this paper is to accurately measure the vibration response of tools and hands by simulating the hand-held power tools, which are operated by astronauts wearing extravehicular spacesuit gloves under microgravity conditions. The total vibration value and the daily vibration exposure of the subject’s hand are obtained. The results show that the opisthenar is more sensitive to the vibration frequency less than 200 Hz. After frequency weighting, the vibration exposure in the composite state of wearing an unpressurized spacesuit glove on the opisthenar is 23.6% greater than the vibration exposure of the palm, and for the bare hand, the percentage is 25.1% under the same condition. Because the operation time of tightening a screw is longer than that of loosening, the tightening operation performed by wearing spacesuit gloves produces 15.7% more mean vibration exposure on the palm and opisthenar than the loosening operation. The results of vibration transmissibility characterized by the total vibration weighted method and the total vibration unweighted method are 0.039 and 0.094, respectively. In comparison with bare hands, the mean daily vibration exposure on the palm and opisthenar in the composite state by wearing spacesuit gloves is 16.3% less, indicating that the unpressurized spacesuit gloves have an effect on vibration reduction. The research reveals the law of hand-transmitted vibration caused by the coupling of the extravehicular activities (EVA) power tools and spacesuit gloves, and provides a novel method for further similar tests and verification of hand-held EVA power tools.
USV Application Scenario Expansion Based on Motion Control, Path Following and Velocity Planning
Authors: Feng Ziang , Pan Zaisheng , Chen Wei , Liu Yong , Leng Jianxing
Published: April 2022

The ability of unmanned surface vehicles (USV) on motion control and the accurate following of preset paths is the embodiment of its autonomy and intelligence, while there is extensive room for improvement when expanding its application scenarios. In this paper, a model fusion of USV and preset path was carried out through the Serret-Frenet coordinate system. Control strategies were then scrupulously designed with the help of Lyapunov stability theory, including resultant velocity control in the presence of drift angle, course control based on the nonlinear backstepping method, and reference point velocity control as a virtual control variable. Specifically, based on USV resultant velocity control, this paper proposes respective solutions for two common scenarios through velocity planning. In a derailment correction scenario, an adaptive reference velocity was designed according to the position and attitude of USV, which promoted its maneuverability remarkably. In a dynamic obstacle avoidance scenario, an appropriate velocity curve was searched by dynamic programming on ST graph and optimized by quadratic programming, which enabled USV to evade obstacles without changing the original path. Simulation results proved the convergence and reliability of the motion control strategies and path following algorithm. Furthermore, velocity planning was verified to perform effectively in both scenarios.
Symmetry Groups, Quantum Mechanics and Generalized Hermite Functions
Authors: Celeghini Enrico , Gadella Manuel , del Olmo Mariano A.
Published: April 2022

This is a review paper on the generalization of Euclidean as well as pseudo-Euclidean groups of interest in quantum mechanics. The Weyl–Heisenberg groups, Hn, together with the Euclidean, En, and pseudo-Euclidean Ep,q, groups are two families of groups with a particular interest due to their applications in quantum physics. In the present manuscript, we show that, together, they give rise to a more general family of groups, Kp,q, that contain Hp,q and Ep,q as subgroups. It is noteworthy that properties such as self-similarity and invariance with respect to the orientation of the axes are properly included in the structure of Kp,q. We construct generalized Hermite functions on multidimensional spaces, which serve as orthogonal bases of Hilbert spaces supporting unitary irreducible representations of groups of the type Kp,q. By extending these Hilbert spaces, we obtain representations of Kp,q on rigged Hilbert spaces (Gelfand triplets). We study the transformation laws of these generalized Hermite functions under Fourier transform.
Efficiency and Productivity of Local Educational Administration in Korea Using the Malmquist Productivity Index
Authors: Eom Moonyoung , Yoo Hyungchul , Yoo Jisung
Published: April 2022

As local governments around the world struggle to finance and deliver quality education under fiscal constraints, pressures mount to increase efficiency and productivity in order to obtain more output from the same or fewer resources. Focusing on the case of Korea, this study investigates the productivity of outputs in local offices of education (OEs) through the analysis of personnel and financial factors by year (2012–2016). Overall, the results indicate the efficient operation of the OEs in Korea. The Malmquist productivity index (MPI) mean decreased from 2012 to 2014, increased from 2014 to 2015, and decreased from 2015 to 2016. The rate of chronological change in each OE’s MPI showed the same pattern of change in the distribution ratio of school expenditures. Finally, the MPI had the same pattern as the Technical Change Index. Policy implications are provided.
A Fractional-Order Compartmental Model of Vaccination for COVID-19 with the Fear Factor
Authors: Chatterjee Amar Nath , Basir Fahad Al , Ahmad Bashir , Alsaedi Ahmed
Published: April 2022

During the past several years, the deadly COVID-19 pandemic has dramatically affected the world; the death toll exceeds 4.8 million across the world according to current statistics. Mathematical modeling is one of the critical tools being used to fight against this deadly infectious disease. It has been observed that the transmission of COVID-19 follows a fading memory process. We have used the fractional order differential operator to identify this kind of disease transmission, considering both fear effects and vaccination in our proposed mathematical model. Our COVID-19 disease model was analyzed by considering the Caputo fractional operator. A brief description of this operator and a mathematical analysis of the proposed model involving this operator are presented. In addition, a numerical simulation of the proposed model is presented along with the resulting analytical findings. We show that fear effects play a pivotal role in reducing infections in the population as well as in encouraging the vaccination campaign. Furthermore, decreasing the fractional-order parameter α value minimizes the number of infected individuals. The analysis presented here reveals that the system switches its stability for the critical value of the basic reproduction number R0=1.
Explicit Information Geometric Calculations of the Canonical Divergence of a Curve
Authors: Felice Domenico , Cafaro Carlo
Published: April 2022

Information geometry concerns the study of a dual structure (g,∇,∇*) upon a smooth manifold M. Such a geometry is totally encoded within a potential function usually referred to as a divergence or contrast function of (g,∇,∇*). Even though infinitely many divergences induce on M the same dual structure, when the manifold is dually flat, a canonical divergence is well defined and was originally introduced by Amari and Nagaoka. In this pedagogical paper, we present explicit non-trivial differential geometry-based proofs concerning the canonical divergence for a special type of dually flat manifold represented by an arbitrary 1-dimensional path γ. Highlighting the geometric structure of such a particular canonical divergence, our study could suggest a way to select a general canonical divergence by using the information from a general dual structure in a minimal way.
Analytical Solutions to Minimum-Norm Problems
Authors: Campos-Jiménez Almudena , Vílchez-Membrilla José Antonio , Cobos-Sánchez Clemente , García-Pacheco Francisco Javier
Published: April 2022

For G∈Rm×n and g∈Rm, the minimization min∥Gψ−g∥2, with ψ∈Rn, is known as the Tykhonov regularization. We transport the Tykhonov regularization to an infinite-dimensional setting, that is min∥T(h)−k∥, where T:H→K is a continuous linear operator between Hilbert spaces H,K and h∈H,k∈K. In order to avoid an unbounded set of solutions for the Tykhonov regularization, we transform the infinite-dimensional Tykhonov regularization into a multiobjective optimization problem: min∥T(h)−k∥andmin∥h∥. We call it bounded Tykhonov regularization. A Pareto-optimal solution of the bounded Tykhonov regularization is found. Finally, the bounded Tykhonov regularization is modified to introduce the precise Tykhonov regularization: min∥T(h)−k∥with∥h∥=α. The precise Tykhonov regularization is also optimally solved. All of these mathematical solutions are optimal for the design of Magnetic Resonance Imaging (MRI) coils.
An Improved Three-Way Clustering Based on Ensemble Strategy
Authors: Wu Tingfeng , Fan Jiachen , Wang Pingxin
Published: April 2022

As a powerful data analysis technique, clustering plays an important role in data mining. Traditional hard clustering uses one set with a crisp boundary to represent a cluster, which cannot solve the problem of inaccurate decision-making caused by inaccurate information or insufficient data. In order to solve this problem, three-way clustering was presented to show the uncertainty information in the dataset by adding the concept of fringe region. In this paper, we present an improved three-way clustering algorithm based on an ensemble strategy. Different to the existing clustering ensemble methods by using various clustering algorithms to produce the base clustering results, the proposed algorithm randomly extracts a feature subset of samples and uses the traditional clustering algorithm to obtain the diverse base clustering results. Based on the base clustering results, labels matching is used to align all clustering results in a given order and voting method is used to obtain the core region and the fringe region of the three way clustering. The proposed algorithm can be applied on the top of any existing hard clustering algorithm to generate the base clustering results. As examples for demonstration, we apply the proposed algorithm on the top of K-means and spectral clustering, respectively. The experimental results show that the proposed algorithm is effective in revealing cluster structures.
Fluorescent Labeling of Polymannuronic Acid and Its Distribution in Mice by Tail Vein Injection
Authors: Song Shuliang , Wei Qiang , Wang Ke , Yang Qiong , Wang Yu , Ji Aiguo , Chen Guanjun
Published: April 2022

Polymannuronic acid (PM) possesses more pharmacological activities than sodium alginate, but there have been few studies on its absorption mechanism, tissue distribution, and pharmacokinetics. Studies of pharmacokinetics and tissue distribution are necessary to elucidate the pharmacological effects of PM. Thus, we used fluorescein isothiocyanate (FITC) to produce fluorescently labeled PM (FITC-PM) and detected the distribution and pharmacokinetics of PM in vivo via tail vein injection. The results demonstrate that the FITC-PM showed high stability in different pH solutions. After the tail vein injection, FITC-PM tended to be distributed in the kidney, followed by the liver and in the heart, spleen, and lungs at lower concentrations. Pharmacokinetic analysis showed that the elimination rate constant of FITC-PM was 0.24, the half-life time was 2.85 h, the peak concentration was 235.17 μg/mL, the area under the curve was 631.48 μg/mL·h, the area under the curve by statistical moment was 1843.15 μg/mL·h2, the mean residence time was 2.92 h, and the clearance rate was 79.18 mL/h. These results indicate that FITC-PM could be used for PM distribution and pharmacokinetic studies, and the studies of pharmacokinetics and tissue distribution provided basic information that can be used to further clarify PM pharmacodynamic mechanisms.