bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanoparticle-Based Drug Delivery Systems for Photodynamic Therapy of Metastatic Melanoma: A Review
Authors: Nkune Nkune Williams , Abrahamse Heidi
Published: November 2021

Metastatic melanoma (MM) is a skin malignancy arising from melanocytes, the incidence of which has been rising in recent years. It poses therapeutic challenges due to its resistance to chemotherapeutic drugs and radiation therapy. Photodynamic therapy (PDT) is an alternative non-invasive modality that requires a photosensitizer (PS), specific wavelength of light, and molecular oxygen. Several studies using conventional PSs have highlighted the need for improved PSs for PDT applications to achieve desired therapeutic outcomes. The incorporation of nanoparticles (NPs) and targeting moieties in PDT have appeared as a promising strategy to circumvent various drawbacks associated with non-specific toxicity, poor water solubility, and low bioavailability of the PSs at targeted tissues. Currently, most studies investigating new developments rely on two-dimensional (2-D) monocultures, which fail to accurately mimic tissue complexity. Therefore, three-dimensional (3-D) cell cultures are ideal models to resemble tumor tissue in terms of architectural and functional properties. This review examines various PS drugs, as well as passive and active targeted PS nanoparticle-mediated platforms for PDT treatment of MM on 2-D and 3-D models. The overall findings of this review concluded that very few PDT studies have been conducted within 3-D models using active PS nanoparticle-mediated platforms, and so require further investigation.
Exploring the Impact of the Microbiome on Neuroactive Steroid Levels in Germ-Free Animals
Authors: Diviccaro Silvia , Caputi Valentina , Cioffi Lucia , Giatti Silvia , Lyte Joshua M. , Caruso Donatella , O’Mahony Siobhain M. , Melcangi Roberto Cosimo
Published: November 2021

Steroid hormones are essential biomolecules for human physiology as they modulate the endocrine system, nervous function and behaviour. Recent studies have shown that the gut microbiota is directly involved in the production and metabolism of steroid hormones in the periphery. However, the influence of the gut microbiota on levels of steroids acting and present in the brain (i.e., neuroactive steroids) is not fully understood. Therefore, using liquid chromatography–tandem mass spectrometry, we assessed the levels of several neuroactive steroids in various brain areas and the plasma of germ-free (GF) male mice and conventionally colonized controls. The data obtained indicate an increase in allopregnanolone levels associated with a decrease in those of 5α-androstane-3α, 17β-diol (3α-diol) in the plasma of GF mice. Moreover, an increase of dihydroprogesterone and isoallopregnanolone in the hippocampus, cerebellum, and cerebral cortex was also reported. Changes in dihydrotestosterone and 3α-diol levels were also observed in the hippocampus of GF mice. In addition, an increase in dehydroepiandrosterone was associated with a decrease in testosterone levels in the hypothalamus of GF mice. Our findings suggest that the absence of microbes affects the neuroactive steroids in the periphery and the brain, supporting the evidence of a microbiota-mediated modulation of neuroendocrine pathways involved in preserving host brain functioning.
Family Perceptions of Newborn Cytomegalovirus Screening: A Qualitative Study
Authors: Cannon Michael J. , Levis Denise M. , McBride Holly , Watson Danie , Rheaume Carol , Hall Mary Ann Kirkconnell , Lanzieri Tatiana M. , Demmler-Harrison Gail
Published: November 2021

We sought to understand long-term retrospective parental perceptions of the utility of newborn screening in a context where many affected children never develop sequelae but where intensive support services and ongoing healthcare were provided. We conducted focus groups and interviews among parents (N = 41) of children with congenital CMV who had been enrolled in a long-term follow-up study at a large medical college for a mean of 22 years following diagnosis. Groups included parents whose children were: symptomatic at birth; initially asymptomatic but later developed sensorineural hearing loss; and who remained asymptomatic into adulthood. With proper follow-up support, newborn CMV screening was viewed positively by parents, who felt empowered by the knowledge, though parents often felt that they and healthcare providers needed more information on congenital CMV. Parents in all groups valued newborn CMV screening in the long term and believed it should be embedded within a comprehensive follow-up program. Despite initial distress, parents of CMV-positive children felt newborn CMV screening was a net positive. Mandatory or opt-out screening for conditions with variable presentations and treatment outcomes may be valuable in contexts where follow-up and care are readily available.
Modifying the Unified Theory of Acceptance and Use of Technology (UTAUT) Model for the Digital Transformation of the Construction Industry from the User Perspective
Authors: Hewavitharana Thathsarani , Nanayakkara Samudaya , Perera Asoka , Perera Prasad
Published: November 2021

Inefficient and ineffective practices in the construction industry have hindered productivity even though it is considered as one of the largest sectors in any county. One best solution to overcome these inherent problems in the construction industry is to move forward with digital technologies. For that, organizational structure, technical aspects, and, most importantly, human factors need to be considered. The aim of this research is to find out human behaviors that affect the digital transformation of the construction industry based on the well-accepted model Unified Theory of Acceptance and Use of Technology (UTAUT). An in-depth literature review was carried out using fifty-five journal papers to develop a conceptual model for the acceptance of digital transformation, and it was validated and further reviewed using ten expert interviews. The model consists of seven constraints: Personal Benefits, Perceived Usefulness, Perceived Risk, Facility Conditions, Attitudes, and Subjective Norms. The analytical hierarchy process (AHP) was carried out to rank these seven factors according to individual priorities in the construction industry. Further, the model was extended and modified using factors derived from literature review and expert feedback. It is proved that “Perceived Personal Benefits” is the major consideration of an individual who is willing to move towards digital transformation. This research fulfills the lack of knowledge in the digitalization of the construction industry as per a human perspective, and it provides a prerequisite to finding the solutions for the issues which emerged within the industry towards digitalization. Further, the framework developed in the research can be used to systematically adopt the human factor for the digital transformation of the construction industry. In addition, this enables the analysis of changing demands for humans in digitally transformed environments, such as Industry 4.0 environments, and contributes towards a successful digital transformation that avoids the pitfalls of innovation performed without attention to human factors. The paper concludes by highlighting future research directions on the human factor in digital transformation as well as managerial implications for successful application in practice.
Prognostic Role of Subclinical Congestion in Heart Failure Outpatients: Focus on Right Ventricular Dysfunction
Authors: Vecchi Andrea , Muccioli Silvia , Marazzato Jacopo , Mancinelli Antonella , Iacovoni Attilio , De Ponti Roberto
Published: November 2021

Background: subclinical pulmonary and peripheral congestion is an emerging concept in heart failure, correlated with a worse prognosis. Very few studies have evaluated its prognostic impact in an outpatient setting and its relationship with right-ventricular dysfunction. The study aims to investigate subclinical congestion in chronic heart failure outpatients, exploring the close relationship between the right heart-pulmonary unit and peripheral congestion. Materials and methods: in this observational study, 104 chronic HF outpatients were enrolled. The degree of congestion and signs of elevated filling pressures of the right ventricle were evaluated by physical examination and a transthoracic ultrasound to define multiparametric right ventricular dysfunction, estimate the right atrial pressure and the pulmonary artery systolic pressure. Outcome data were obtained by scheduled visits and phone calls. Results: ultrasound signs of congestion were found in 26% of patients and, among this cohort, half of them presented as subclinical, affecting their prognosis, revealing a linear correlation between right ventricular/arterial coupling, the right-chambers size and ultrasound congestion. Right ventricular dysfunction, TAPSE/PAPS ratio, clinical and ultrasound signs of congestion have been confirmed to be useful predictors of outcome. Conclusions: subclinical congestion is widespread in the heart failure outpatient population, significantly affecting prognosis, especially when right ventricular dysfunction also occurs, suggesting a strict correlation between the heart-pulmonary unit and volume overload.
Differences in Fat-Free Mass According to Serum Vitamin D Level and Calcium Intake: Korea National Health and Nutrition Examination Survey 2008–2011
Authors: An Hye-Ji , Seo Young-Gyun
Published: November 2021

We analyzed the differences in fat-free mass (FFM) according to serum vitamin D level (VitD) and daily calcium intake (Ca) in 14,444 adults aged over 19 years. We used data from the 4th and 5th Korea National Health and Nutrition Examination Surveys (2008–2011). FFM was measured using dual-energy X-ray absorptiometry. VitD was classified as insufficient or sufficient (cutoff: 20 ng/mL). Ca was classified as unsatisfactory or satisfactory (recommended daily intake: 700 mg). In men, the FFM of group 2 (VitD ≥ 20 ng/mL; Ca < 700 mg), group 3 (VitD < 20 ng/mL; Ca ≥ 700 mg) and group 4 (VitD ≥ 20 ng/mL; Ca ≥ 700 mg) was 0.50 kg (95% confidence interval (CI), 0.084–0.92), 0.78 kg (95% CI, 0.26–1.29) and 1.58 kg (95% CI, 0.95–2.21) higher than that of group 1 (VitD < 20 ng/mL; Ca < 700 mg), respectively. In women, a 1 ng/mL increase in VitD was associated with a 0.023 kg increase in FFM (95% CI, 0.003–0.043) and a 1 g increase in Ca was associated with a 0.62 kg increase in FFM (95% CI, 0.067–1.16). High VitD and Ca were associated with a high FFM.
Reliability of Different Anterior Cranial Base Reference Areas for Voxel-Based Superimposition
Authors: Ghamri Mohammed , Kanavakis Georgios , Gkantidis Nikolaos
Published: November 2021

The study aimed to evaluate the reliability and reproducibility and compare the outcomes of two 3D voxel-based superimposition techniques for craniofacial CBCT images, using anterior cranial base areas of different extent as references. Fifteen preexisting pairs of serial CBCTs (initial age: 11.7 ± 0.6 years; interval: 1.7 ± 0.4 years) were superimposed on total anterior cranial base (TACB) or middle anterior cranial base (MACB) structures through the Dolphin 3D software. The overlap of the reference structures was assessed visually to indicate reliability. All superimpositions were repeated by the same investigator. Outcomes were compared to assess the agreement between the two methods. Reliability was perfect for the TACB and moderate for the MACB method (p = 0.044). Both areas showed good overall reproducibility, though in individual cases there were notable differences for MACB superimpositions, ranging from −1.84 to 1.64 mm (TACB range: −0.48 to 0.31 mm). The overall agreement in the detected T0/T1 changes was also good, though it was significantly reduced for individual measurements (median < 0.01 mm, IQR: 0.46 mm, range: −2.81 to 0.73 mm). In conclusion, the voxel-based superimposition on TACB was more reliable and showed higher reproducibility than the superimposition on MACB. Thus, the extended anterior cranial base area is recommended for the assessment of craniofacial changes.
Exploring Consensus on Preventive Measures and Identification of Patients at Risk of Age-Related Macular Degeneration Using the Delphi Process
Authors: García-Layana Alfredo , Garhöfer Gerhard , Aslam Tariq M. , Silva Rufino , Delcourt Cécile , Klaver Caroline C. W. , Seddon Johanna M. , Minnella Angelo M.
Published: November 2021

Background: Early identification of AMD can lead to prompt and more effective treatment, better outcomes, and better final visual acuity; several risk scores have been devised to determine the individual level of risk for developing AMD. Herein, the Delphi method was used to provide recommendations for daily practice regarding preventive measures and follow-up required for subjects at low, moderate, and high risk of AMD evaluated with the Simplified Test AMD Risk-assessment Scale (STARS®) questionnaire. Methods: A steering committee of three experts drafted and refined 25 statements on the approach to be recommended in different clinical situations [general recommendations (n = 2), use of evaluation tools (n = 4), general lifestyle advice (n = 3), and AREDS-based nutritional supplementation (n = 5)] with the help of a group of international experts, all co-authors of this paper. Thirty retinal specialists from Europe and the US were chosen based on relevant publications, clinical expertise, and experience in AMD, who then provided their level of agreement with the statements. Statements for which consensus was not reached were modified and voted upon again. Results: In the first round of voting, consensus was reached for 24 statements. After modification, consensus was then reached for the remaining statement. Conclusion: An interprofessional guideline to support preventive measures in patients at risk of AMD based on STARS® scoring has been developed to aid clinicians in daily practice, which will help to optimize preventive care of patients at risk of AMD.
Higher-Order Free Vibration Analysis of Porous Functionally Graded Plates
Authors: Merdaci Slimane , Adda Hadj Mostefa , Hakima Belghoul , Dimitri Rossana , Tornabene Francesco
Published: November 2021

The present work analyzes the free vibration response of functionally graded (FG) plates made of Aluminum (Al) and Alumina (Al2O3) with different porosity distributions, as usually induced by a manufacturing process. The problem is tackled theoretically based on a higher-order shear deformation plate theory, while proposing a Navier-type approximation to solve the governing equations for simply-supported plates with different porosity distributions in the thickness direction. The reliability of the proposed theory is checked successfully by comparing the present results with predictions available from literature based on further first-order or higher-order theories. A large parametric study is performed systematically to evaluate the effect of different mechanical properties, such as the material indexes, porosity volume fractions, porosity distributions, and length-to-thickness ratios, on the free vibration response of FG plates, as useful for the design purposes of most engineered materials and composite applications.
Sedimentary Sequence, Evolution Model and Petroleum Geological Significance of Forced Regression: A Case Study of the Miocene Zhujiang Formation of the Pearl River Mouth Basin in the Northern South China Sea
Authors: Yu Ye , Cai Linghui , Zhang Changmin , Wang Li , Zhu Rui , Huang Yanran , Cao Taotao
Published: November 2021

Using 2D/3D seismic data and a large number of drilling and logging data and applying sequence stratigraphy, seismic sedimentology, and petroleum geology concepts, the characteristics of the sedimentary sequence of the forced regression have been analysed, the migration trajectory of the coastline have been reconstructed, the evolution model of the forced regression have been presented, and the significance for petroleum geology of the forced regressive sandbodies have been discussed. The falling stage systems tract (FSST) of the Zhujiang Formation present offlap high-angle oblique foreset reflection structure in the seismic profiles of the depositional trends and turbidite fan deposits with strong amplitude mound reflection structure are developed in the downdip direction of its front. The trajectory of migration of the shoreline shows a terraced downtrend in the direction of basin. The FSST is characterized by the shelf-edge delta without topset beds. The FSST was formed in the fall of relative sea-level. Five sets of foreset beds controlled by high-frequency relative eustatic were developed, therefore ordinal regressive overlap can be observed for the five sets of shelf-edge deltas in the depositional trends. The favourable reservoirs which were located close to the upper boundary of the falling stage systems tract and the basal surface of forced regression are sandbodies of the shelf-edge delta front and wave-dominated shoreface sands and the sandbodies of the turbidite fan. Those sandbodies favour the formation of lithologic oil–gas reservoirs by means of good trap sealing conditions, excellent oil–gas reserving performance, and effective oil source communication of fracture system.
Prognostic Scores and Azole-Resistant Aspergillus fumigatus in Invasive Aspergillosis from an Indian Respiratory Medicine ICU (ICU Patients with IA Suspicion)
Authors: Dabas Yubhisha , Mohan Anant , Xess Immaculata
Published: November 2021

Objective: To assess the effectiveness of three general prognostic models (APACHE II, SAPS II, and SOFA) with serum galactomannan antigen in a clinically suspected invasive aspergillosis (IA) subpopulation admitted to a respiratory medicine ICU and to identify azole-resistant Aspergillus fumigatus (ARAF) cases. Methodology and Results: A total of 235 clinically suspected IA patients were prospectively enrolled and observed 30-day mortality was 29.7%. The three general models showed poor discrimination assessed by area under receiver operating characteristic (ROC) curves (AUCs, <0.7) and good calibration (p = 0.92, 0.14, and 0.13 for APACHE II, SAPS II, and SOFA, respectively), evaluated using Hosmer–Lemeshow goodness-of-fit tests. However, discrimination was significantly better with galactomannan values (AUC, 0.924). In-vitro antifungal testing revealed higher minimum inhibitory concentration (MIC) for 12/34 isolates (35.3%) whereas azole resistance was noted in 40% of Aspergillus fumigatus isolates (6/15) with two hotspot cyp51A mutations, G54R and P216L. Conclusions: Patients diagnosed with putative and probable IA (71.4% and 34.6%, respectively), had high mortality. The general prognostic model APACHE II seemed fairly accurate for this subpopulation. However, the use of local GM cut-offs calculated for mortality, may help the intensivists in prompt initiation or change of therapy for better outcome of patients. In addition, the high MICs highlight the need of antifungal surveillance to know the local resistance rate which might aid in patient treatment.
Light Irradiation Coupled with Exogenous Metal Ions to Enhance Exopolysaccharide Synthesis from Agaricus sinodeliciosus ZJU-TP-08 in Liquid Fermentation
Authors: Lu Hongyun , Liu Siyu , Zhang Shengliang , Chen Qihe
Published: November 2021

To promote Agaricus sinodeliciosus var. Chaidam ZJU-TP-08 growth and metabolites accumulation, a novel integrated strategy was developed by adopting high levels of metal ions coupled with light treatment. The results revealed that yellow and blue light could significantly promote biomass and exopolysaccharides production, respectively. Furthermore, the yellow–blue light shift strategy could stimulate exopolysaccharides formation. Ca2+ ions coupled with blue light mostly promoted exopolysaccharides production related to oxidative stress, which was 42.00% and 58.26% higher than that of Ca2+ ions coupled with the non-light and dark cultivation without Ca2+ ions in 5-L bioreactor. RNA-seq was performed to uncover the underlined molecular mechanism regulated by light-induced gene expressions in exopolysaccharides biosynthesis and oxidative stress. The findings of this work provide valuable insights into adopting metal ions coupled with the light-assisted method for the macrofungus submerged fermentation for exopolysaccharides production.
Individual Differences in Emotion Dysregulation and Social Anxiety Discriminate between High vs. Low Quality of Life in Patients with Mild Psoriasis
Authors: Fino Edita , Russo Paolo Maria , Tengattini Vera , Bardazzi Federico , Patrizi Annalisa , Martoni Monica
Published: November 2021

A deeper understanding of how health-related quality of life relates to the clinical and individual characteristics of patients is essential for the delivery of patient-centered dermatological care. The current study aimed to examine the role of individual differences in emotion dysregulation and social anxiety in modulating quality of life in psoriatic patients. A total of 130 patients affected by psoriasis were consecutively enrolled in the study as they approached the Dermatology Unit of Sant’Orsola-Malpighi Hospital of Bologna. Clinical information gathered included illness severity, assessed with the Psoriasis Area and Severity Index (PASI) and the Body Surface Area (BSA); illness onset; familiarity; and prescribed treatment. The patient-reported outcome measures were the Dermatology Life Quality Index (DLQI), measuring the patient’s quality of life; the Psoriasis Skin Appearance Bothersomeness scale (PSAB), measuring patient’s perception of illness severity; the Difficulties in Emotion Regulation Scale (DERS), assessing emotion dysregulation traits; and the Social Interaction Anxiety Scale (SIAS), measuring anxiety about social interactions. Patients with moderate-to-severe psoriasis reported significantly lower quality of life compared to mildly affected patients. In addition, of the patients affected by mild psoriasis, those characterized by emotion dysregulation and social anxiety traits showed significantly lower levels of quality of life. Our findings suggest that individual differences in emotion dysregulation and social anxiety contribute to health-related quality of life in addition to illness severity. Therapeutic approaches that combine dermatological care with psychological support, especially focused on emotional regulation skills, may be useful to improve clinical outcomes in patients with psoriasis.
PSI-Guided Mandible-First Orthognathic Surgery: Maxillo-Mandibular Position Accuracy and Vertical Dimension Adjustability
Authors: Badiali Giovanni , Bevini Mirko , Lunari Ottavia , Lovero Elisa , Ruggiero Federica , Bolognesi Federico , Feraboli Liliana , Bianchi Alberto , Marchetti Claudio
Published: November 2021

In orthognathic surgery, patient-specific osteosynthesis implants (PSIs) represent a novel approach for the reproduction of the virtual surgical planning on the patient. The aim of this study is to analyse the quality of maxillo-mandibular positioning using a hybrid mandible-first mandibular-PSI-guided procedure on twenty-two patients while the upper maxilla was fixed using manually bent stock titanium miniplates. The virtual surgical plan was used to design PSIs and positioning guides, which were then 3D printed using biocompatible materials. A Cone Beam Computed Tomography (CBCT) scan was performed one month after surgery and postoperative facial skeletal models were segmented for comparison against the surgical plan. A three-dimensional cephalometric analysis was carried out on both planned and obtained anatomies. A Spearman correlation matrix was computed on the calculated discrepancies in order to achieve a more comprehensive description of maxillo-mandibular displacement. Intraoperatively, all PSIs were successfully applied. The procedure was found to be accurate in planned maxillo-mandibular positioning reproduction, while maintaining a degree of flexibility to allow for aesthetics-based verticality correction in a pitch range between −5.31 and +1.79 mm. Such a correction did not significantly affect the achievement of planned frontal symmetry.
Delineating Urban Functional Zones Using U-Net Deep Learning: Case Study of Kuancheng District, Changchun, China
Authors: Yang Yuewen , Wang Dongyan , Yan Zhuoran , Zhang Shuwen
Published: November 2021

Scientific functional zone planning is the key to achieving long-term development goals for cities. The rapid development of remote sensing technology allows for the identification of urban functional zones, which is important since they serve as basic spatial units for urban planning and functioning. The accuracy of three methods—kernel density estimation, term frequency-inverse document frequency, and deep learning—for detecting urban functional zones was investigated using the Gaode points of interest, high-resolution satellite images, and OpenStreetMap. Kuancheng District was divided into twenty-one functional types (five single functional types and twenty mixed ones). The results showed that an approach using deep learning had a higher accuracy than the other two methods for delineating four out of five functions (excluding the commercial function) when compared with a field survey. The field survey showed that Kuancheng District was progressing towards completing the goals of the Land-Use Plan of the Central City of Changchun (2011–2020). Based on these findings, we illustrate the feasibility of identifying urban functional areas and lay out a framework for transforming them. Our results can guide the adjustment of the urban spatial structure and provide a reference basis for the scientific and reasonable development of urban land-use planning.
Evaluating the Space Use of Large Railway Hub Station Areas in Beijing toward Integrated Station-City Development
Authors: Liang Ying , Song Wei , Dong Xiaofeng
Published: November 2021

With the large-scale construction of high-speed railways and the continuous increase in population flows, railway hubs are becoming the most dynamic places in cities. As a key node of intercity traffic and an important part of urban development, railway hub stations are the main carriers for the implementation of the Integrated Station-City Development (ISCD) strategy. A comprehensive evaluation of the space use of railway hub station areas can provide a basic understanding of the intensive utilization and optimization of urban space. However, existing relevant studies lack a comprehensive assessment of the compound structures and functions within large railway hub station areas at the microscopic level. Therefore, this paper was guided by integrated station-city development, relying on Geographic Information Science (GIS)technology, and big data such as Points of Interest (POI) and real-time traffic, focusing on walking accessibility, facility convenience, function compound, and land development intensity used around railway hub station areas. The uses of the station areas in four large railway hubs in Beijing were analyzed. Based on this, we built an ISCD index, combined with the Analytic Hierarchy Process (AHP) method, and assessed the degree of ISCD in the four railway hubs. The study showed that among the four large railway hubs in Beijing, the Beijing North railway station offers the best walking accessibility. The Beijing railway station features the largest facility convenience, function compound, and land development intensity. In general, the levels of ISCD of the Beijing and Beijing North Railway Stations were significantly higher than those of the Beijing West and Beijing South Railway Stations.
Leydig Cells in Patients with Non-Obstructive Azoospermia: Do They Really Proliferate?
Authors: Hauptman Dinko , Perić Marta Himelreich , Marić Tihana , Bojanac Ana Katušić , Sinčić Nino , Zimak Zoran , Kaštelan Željko , Ježek Davor
Published: November 2021

Background: Non-obstructive azoospermia (NOA) is a form of male infertility caused by disorders of the testicular parenchyma and impaired spermatogenesis. This study aimed to investigate the nature of Leydig cell changes in patients with NOA, especially whether their actual proliferation occurred. Methods: 48 testicular biopsies from infertile patients with NOA and 24 testicular biopsies originating from azoospermic patients suffering from obstructive azoospermia (OA) were included in the study. Leydig cells and their possible proliferative activity were analysed by immunohistochemistry and morphometry (stereology). Results: Unlike in the OA group, Leydig cells in NOA patients were sometimes organised into larger clusters and displayed an abundant cytoplasm/hypertrophy. Moreover, significant fibrosis of the interstitial compartment was demonstrated in some NOA samples, often accompanied by inflammatory cells. Stereological analysis showed no increase/proliferation of Leydig cells; on the contrary, these cells decreased in number in the NOA group. Conclusions: The decrease in the number of Leydig cells can be explained by previous inflammatory changes within the testicular interstitium and consequent interstitial fibrosis. The interstitial fibrosis might have a deteriorating effect on Leydig cells.
Additives Imparting Antimicrobial Properties to Acrylic Bone Cements
Authors: Robu Alina , Antoniac Aurora , Grosu Elena , Vasile Eugeniu , Raiciu Anca Daniela , Iordache Florin , Antoniac Vasile Iulian , Rau Julietta V. , Yankova Viktoriya G. , Ditu Lia Mara , Saceleanu Vicentiu
Published: November 2021

PMMA bone cements are mainly used to fix implanted prostheses and are introduced as a fluid mixture, which hardens over time. The problem of infected prosthesis could be solved due to the development of some new antibacterial bone cements. In this paper, we show the results obtained to develop four different modified PMMA bone cements by using antimicrobial additives, such as gentamicin, peppermint oil incorporated in hydroxyapatite, and silver nanoparticles incorporated in a ceramic glass matrix (2 and 4%). The structure and morphology of the modified bone cements were investigated by SEM and EDS. We perform experimental measurements on wettability, hydration degree, and degradation degree after immersion in simulated body fluid. The cytotoxicity was evaluated by MTT assay using the human MG-63 cell line. Antimicrobial properties were checked against standard strains Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. The addition of antimicrobial agents did not significantly affect the hydration and degradation degree. In terms of biocompatibility assessed by the MTT test, all experimental PMMA bone cements are biocompatible. The performance of bone cements with peppermint essential oil and silver nanoparticles against these two pathogens suggests that these antibacterial additives look promising to be used in clinical practice against bacterial infection.
Computation of High-Performance Concrete Compressive Strength Using Standalone and Ensembled Machine Learning Techniques
Authors: Xu Yue , Ahmad Waqas , Ahmad Ayaz , Ostrowski Krzysztof Adam , Dudek Marta , Aslam Fahid , Joyklad Panuwat
Published: November 2021

The current trend in modern research revolves around novel techniques that can predict the characteristics of materials without consuming time, effort, and experimental costs. The adaptation of machine learning techniques to compute the various properties of materials is gaining more attention. This study aims to use both standalone and ensemble machine learning techniques to forecast the 28-day compressive strength of high-performance concrete. One standalone technique (support vector regression (SVR)) and two ensemble techniques (AdaBoost and random forest) were applied for this purpose. To validate the performance of each technique, coefficient of determination (R2), statistical, and k-fold cross-validation checks were used. Additionally, the contribution of input parameters towards the prediction of results was determined by applying sensitivity analysis. It was proven that all the techniques employed showed improved performance in predicting the outcomes. The random forest model was the most accurate, with an R2 value of 0.93, compared to the support vector regression and AdaBoost models, with R2 values of 0.83 and 0.90, respectively. In addition, statistical and k-fold cross-validation checks validated the random forest model as the best performer based on lower error values. However, the prediction performance of the support vector regression and AdaBoost models was also within an acceptable range. This shows that novel machine learning techniques can be used to predict the mechanical properties of high-performance concrete.
The Effect of AlI3 Nanoadditive on the Thermal Behavior of PMMA Subjected to Thermoanalytical Py-GC-MS Technique
Authors: Adnan Muhammad , Rahman Taj Ur , Bahadur Ali , Zeb Muhammad Aurang , Liaqat Wajiha , Akitsu Takashiro , Abdel-Hafez Shams H. , El-Sayed Wael A.
Published: November 2021

Thermal degradation of polymethylmethacrylate (PMMA) was studied by using inorganic salt of aluminum triiodide (AlI3). The composites of PMMA were prepared with AlI3 by changing the concentration of the AlI3 additive from 2% to 10% (w/w). The PMMA composites with AlI3 were characterized by TGA, DTG, SEM, FTIR, HBT, and Py-GC-MS techniques. The FTIR peaks of PMMA composite at 1316, 786, and 693 cm−1 justify the chemical association between PMMA and AlI3. TGA study shows that the stability of PMMA is enhanced by the addition of the AlI3 additive. SEM analysis represented that there is a relationship between polymer and additive when they are mixed at the molecular level. The horizontal burning test (HBT) also confirmed that the AlI3 additive produced the flame retarding properties in PMMA polymer. The burning rate of composite with 10% of AlI3 additive decreases five times as much as compared to pure PMMA polymer. Py-GC-MS analysis deduced that PMMA composite produced less toxic and environment-friendly substances (CO2) by the influence of AlI3 additive as compared to neat PMMA.
Performance Comparison of Zn-Based and Al–Si Based Coating on Boron Steel in Hot Stamping
Authors: Chen Long , Chen Wei , Cao Miao , Li Xin
Published: November 2021

The coatings of boron steels play an important role in affecting the quality of hot stamping parts, so it is important to evaluate the hot stamping performance of coatings before designing processes. Taking the U-type hot stamping part of boron steel as research objects, the surface quality, microstructure and temperature variation of samples with GA (galvannealed), GI (galvanized) and Al–Si coatings were observed and analyzed to evaluate the anti-oxidation, forming and quenching performances of different coatings. The results show that all the GA, GI and Al–Si coatings could provide good oxidation protection and also act as the lubricants for avoiding the friction damage of sample substrates and die-surface. But the different compositions of GA, GI and Al–Si coatings will contribute the different colors. Under the same deformation degree, the Al–Si coating can provide the best substrate protection and the GI coating will induce cracks in the substrate because of the liquid metal-induced embrittlement phenomenon. There is no significant difference between the quenching performances of GA, GI and Al–Si coatings, and the thermal conductivity of the GI coating is slightly better than Al–Si and GA coatings.
Electromagnetic Wave Shielding Properties of Amorphous Metallic Fiber-Reinforced High-Strength Concrete Using Waveguides
Authors: Lee Sangkyu , Kim Gyuyong , Kim Hongseop , Son Minjae , Lee Yaechan , Choi Yoonseon , Woo Jongmyung , Nam Jeongsoo
Published: November 2021

In this study, high-strength concrete containing hooked-end steel or amorphous metallic fibers was fabricated, and the electrical conductivity and electromagnetic shielding effectiveness were evaluated after 28 and 208 days based on considerations of the influences of the moisture content. Amorphous metallic fibers, which have the same length and length/equivalent diameter ratio as hooked-end steel fibers, were favored for the formation of a conductive network because they can be added in large quantities owing to their low densities. These fibers have a large specific surface area as thin plates. The electromagnetic shielding effectiveness clearly improved as the electrical conductivity increased, and it can be expected that the shielding effectiveness will approach the saturation level when the fiber volume fraction of amorphous metallic fibers exceeds 0.5 vol.%. Meanwhile, it is necessary to reduce the amount of moisture to conservatively evaluate the electromagnetic shielding performance. In particular, when 0.5 vol.% of amorphous metallic fibers was added, a shielding effectiveness of >80 dB (based on a thickness of 300 mm) was achieved at a low moisture content after 208 days. Similar to the electrical conductivity, excellent shielding effectiveness can be expected from amorphous metallic fibers at low contents compared to that provided by hooked-end steel fibers.
Regularities of Structure Formation in 30 mm Rods of Thermoelectric Material during Hot Extrusion
Authors: Lavrentev Mikhail G. , Bublik Vladimir T. , Milovich Filipp O. , Panchenko Viktoriya P. , Parkhomenko Yuri N. , Prostomolotov Anatoly I. , Tabachkova Nataliya Yu. , Verezub Nataliya A. , Voronov Mikhail V. , Yarkov Ivan Yu.
Published: November 2021

In this study, Ingots of (Bi, Sb)2Te3 thermoelectric material with p-type conductivity have been obtained by hot extrusion. The main regularities of hot extrusion of 30 mm rods have been analyzed with the aid of a mathematical simulation on the basis of the joint use of elastic-plastic body approximations. The phase composition, texture and microstructure of the (Bi, Sb)2Te3 solid solutions have been studied using X-ray diffraction and scanning electron microscopy. The thermoelectric properties have been studied using the Harman method. We show that extrusion through a 30 mm diameter die produces a homogeneous strain. The extruded specimens exhibit a fine-grained structure and a clear axial texture in which the cleavage planes are parallel to the extrusion axis. The quantity of defects in the grains of the (Bi, Sb)2Te3 thermoelectric material decreases with an increase in the extrusion rate. An increase in the extrusion temperature leads to a decrease in the Seebeck coefficient and an increase in the electrical conductivity. The specimens extruded at 450 °C and a 0.5 mm/min extrusion rate have the highest thermoelectric figure of merit (Z = 3.2 × 10−3 K−1).
Wear Analysis of Forging Tools Used in an Industrial Production Process—Hot Forging in Closed Dies of the “Head-Disk” of an Engine Valve Forging
Authors: Hawryluk Marek , Ziemba Jacek , Janik Marta , Górski Piotr , Dudkiewicz Łukasz , Głód Kornelia , Krawczyk Jakub
Published: November 2021

The article performs an analysis of the durability of punches applied in the process of producing a valve forging from chromium-nickel steel. A forging of this type is made in two operations: coextrusion of a long shank, followed by finishing forging in closed dies of the valve head. The product obtained in this way (after other additional finishing procedures) constitutes the key element of the combustion engine (resistant to high pressures and temperatures) in motor trucks. Unfortunately, a significant problem in this production process is a relatively low durability of the forging tools, especially the punch used in the second forging operation. The key element at this stage, deciding about the punch’s further operation, is the area of the so-called “calotte”. The short-term life of the tools results from very hard performance conditions present during the forging process (periodical high mechanical and thermal loads, long path of friction). The latter cause intensive abrasive wear as well as high adhesion of the forging material to the tool surface. Based on the performed studies, including the following: technology analysis, numerical modelling, macro analyses combined with 3D scanning of tool sections as well as microstructural tests and hardness measurements, it was established that it is crucial to properly select the process parameters (charge and tool temperature, tribological conditions), as even slight changes introduced into them significantly affect the operation time of the forging tools. Mastering and proper implementation of the analyzed forging technology requires numerous further studies and tests, which will enable its perfection and thus increase the durability of the tools as well as the quality of the produced items.
Highly Stable Potentiometric (Bio)Sensor for Urea and Urease Activity Determination
Authors: Urbanowicz Marcin , Sadowska Kamila , Paziewska-Nowak Agnieszka , Sołdatowska Anna , Pijanowska Dorota G.
Published: November 2021

There is growing interest for bioanalytical tools that might be designed for a specific user, primarily for research purposes. In this perspective, a new, highly stable potentiometric sensor based on glassy carbon/polyazulene/NH4+-selective membrane was developed and utilized for urease activity determination. Urease–urea interaction studies were carried out and the Michaelis–Menten constant was established for this enzymatic reaction. Biofunctionalization of the ammonium ion-selective sensor with urease lead to urea biosensor with remarkably good potential stability (drift coefficient ~0.9 mV/h) and short response time (t95% = 36 s). The prepared biosensor showed the Nernstian response (S = 52.4 ± 0.7 mV/dec) in the urea concentration range from 0.01 to 20 mM, stable for the experimental time of 60 days. In addition, some insights into electrical properties of the ion-to-electron transducing layer resulting from impedance spectroscopy measurements are presented. Based on the RCQ equivalent circuits comparison, it can be drawn that the polyazulene (PAz) layer shows the least capacitive behavior, which might result in good time stability of the sensor in respect to response as well as potential E0. Both the polyazulene-based solid-contact ion selective electrodes and urea biosensors were successfully used in trial studies for determination of ammonium ion and urea in human saliva samples. The accuracy of ammonium ion and urea levels determination by potentiometric method was confirmed by two reference spectrophotometric methods.
A Novel Nitrogen Ion Implantation Technique for Turning Thin Film “Normally On” AlGaN/GaN Transistor into “Normally Off” Using TCAD Simulation
Authors: Sheu Gene , Song Yu-Lin , Susmitha Dupati , Issac Kutagulla , Mogarala Ramyasri
Published: November 2021

This study presents an innovative, low-cost, mass-manufacturable ion implantation technique for converting thin film normally on AlGaN/GaN devices into normally off ones. Through TCAD (Technology Computer-Aided Design) simulations, we converted a calibrated normally on transistor into a normally off AlGaN/GaN transistor grown on a silicon <111> substrate using a nitrogen ion implantation energy of 300 keV, which shifted the bandgap from below to above the Fermi level. In addition, the threshold voltage (Vth) was adjusted by altering the nitrogen ion implantation dose. The normally off AlGaN/GaN device exhibited a breakdown voltage of 127.4 V at room temperature because of impact ionization, which showed a positive temperature coefficient of 3 × 10−3 K−1. In this study, the normally off AlGaN/GaN device exhibited an average drain current gain of 45.3%, which was confirmed through an analysis of transfer characteristics by changing the gate-to-source ramping. Accordingly, the proposed technique enabled the successful simulation of a 100-µm-wide device that can generate a saturation drain current of 1.4 A/mm at a gate-to-source voltage of 4 V, with a mobility of 1487 cm2V−1s−1. The advantages of the proposed technique are summarized herein in terms of processing and performance.
Recovery of Biologically Treated Textile Wastewater by Ozonation and Subsequent Bipolar Membrane Electrodialysis Process
Authors: Yuzer Burak , Selcuk Huseyin
Published: November 2021

The Bipolar Membrane Electrodialysis process (BPMED) can produce valuable chemicals such as acid (HCl, H2SO4, etc.) and base (NaOH) from saline and brackish waters under the influence of an electrical field. In this study, BPMED was used to recover wastewater and salt in biologically treated textile wastewater (BTTWW). BPMED process, with and without pre-treatment (softening and ozonation), was evaluated under different operational conditions. Water quality parameters (color, remaining total organic carbon, hardness, etc.) in the acid, base and filtrated effluents of the BPMED process were evaluated for acid, base, and wastewater reuse purposes. Ozone oxidation decreased 90% of color and 37% of chemical oxygen demand (COD) in BTTWW. As a result, dye fouling on the anion exchange membrane of the BPMED process was reduced. Subsequently, over 90% desalination efficiency was achieved in a shorter period. Generated acid, base, and effluent wastewater of the BPMED process were found to be reusable in wet textile processes. Results indicated that pre-ozonation and subsequent BPMED membrane systems might be a promising solution in converging to a zero discharge approach in the textile industry.
One-Step Electrodeposition of Superhydrophobic Coating on 316L Stainless Steel
Authors: Zaffora Andrea , Di Franco Francesco , Megna Bartolomeo , Santamaria Monica
Published: November 2021

Superhydrophobic coatings were fabricated through a one-step electrochemical process onto the surface of 316L stainless steel samples. The presence of hierarchical structures at micro/nanoscale and manganese stearate into the coatings gave superhydrophobicity to the coating, with contact angle of ~160°, and self-cleaning ability. Corrosion resistance of 316L samples was also assessed also after the electrodeposition process through Electrochemical Impedance Spectra recorded in an aqueous solution mimicking seawater condition.
Investigation on Vanadium Chemistry in Basic-Oxygen-Furnace (BOF) Slags—A First Approach
Authors: Wunderlich Sophie , Schirmer Thomas , Fittschen Ursula E. A.
Published: November 2021

Basic oxygen furnace (BOF) slag accounts for the majority of all residual materials produced during steelmaking and may typically contain certain transition metals. Vanadium, in particular, came into focus in recent years because of its potential environmental toxicity as well as its economic value. This study addresses the vanadium chemistry in BOF slags to better understand its recovery and save handling of the waste stream. The experimental results from the electron probe microanalysis (EPMA) study show that vanadium is preferably incorporated in calcium orthosilicate-like compounds (COS), with two variations occurring, a low vanadium COS (COS-Si) (approx. 1 wt.%), and a high vanadium COS (COS-V) (up to 18 wt.%). Additionally, vanadium is incorporated in dicalcium ferrite-like compounds (DFS) with an average amount of 3 wt.%. Using powder x-ray diffraction analysis (PXRD), EPMA, and virtual component models, stoichiometric formulas of the main vanadium-bearing phases were postulated. The stoichiometries give an estimate of the oxidation states of vanadium in the respective hosts. According to these results, trivalent vanadium is incorporated on the Fe-position in dicalcium ferrite solid solution (DFS), and V4+ and V5+ are incorporated on the Si-position of the COS.