bluuebunny/crossref_metadata_2025 huggingface dataset:
Chronic Rhinosinusitis with Nasal Polyps: A Survey on Routine Management and Evaluation of Disease Control in Practice
Authors: De Corso Eugenio , Ottaviano Giancarlo , Pipolo Carlotta , Cantone Elena , Mattavelli Davide , Alicandri-Ciufelli Matteo , Lucidi Daniela , Caminati Marco , Senna Gianenrico , Cavaliere Carlo , Ghidini Angelo , Gallo Stefania , Macchi Alberto , Torretta Sara , Seccia Veronica , Garzaro Massimiliano , Fadda Gian Luca , Trimarchi Matteo , Pasquini Ernesto , Pagella Fabio , Canevari Frank Rikki , Preti Andrea , La Mantia Ignazio , Galli Jacopo
Published: October 2023

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a disease with a significant impact on quality of life. The overall goal of CRSwNP management, as with other chronic conditions, is to achieve “disease control”, and for that reason, a definition of control of disease is pivotal in deciding the best treatment strategy. Although many staging systems have already been developed to evaluate the disease, disease control is not yet to be standardized, and a specific tool that is consistently applied and accepted by all practitioners is still missing in daily clinical practice. To gain an overview of the implementation and limitations of existing guidelines and to shed light on real-life definitions of control and disease severity, we conducted a nationwide survey of otorhinolaryngologists routinely treating CRSwNP to identify unmet clinical needs in Italy. The results showed homogeneous responses regarding the knowledge contained in international guidelines while highlighting the difficulty of their implementation in day-to-day practice. Respondents called attention to the importance of clinical symptoms, giving more weight to the patient’s perspective. Among the symptoms to be considered, respondents emphasized nasal obstruction, followed by loss of sense of smell and rhinorrhea. Others also believe that the physician’s perspective should be considered, and the inclusion of endoscopy as a measure of control was warranted by many. The need for a specific tool that is able to unequivocally ascertain disease control is increasingly pivotal in this new era of biologics for treating CRSwNP.
Point-of-Care Disease Screening in Primary Care Using Saliva: A Biospectroscopy Approach for Lung Cancer and Prostate Cancer
Authors: Martin Francis L. , Morais Camilo L. M. , Dickinson Andrew W. , Saba Tarek , Bongers Thomas , Singh Maneesh N. , Bury Danielle
Published: October 2023

Saliva is a largely unexplored liquid biopsy that can be readily obtained noninvasively. Not dissimilar to blood plasma or serum, it contains a vast array of bioconstituents that may be associated with the absence or presence of a disease condition. Given its ease of access, the use of saliva is potentially ideal in a point-of-care screening or diagnostic test. Herein, we developed a swab “dip” test in saliva obtained from consenting patients participating in a lung cancer-screening programme being undertaken in north-west England. A total of 998 saliva samples (31 designated as lung-cancer positive and 17 as prostate-cancer positive) were taken in the order in which they entered the clinic (i.e., there was no selection of participants) during the course of this prospective screening programme. Samples (sterile Copan blue rayon swabs dipped in saliva) were analysed using attenuated total reflection Fourier-transform infrared (ATR-FTIR) spectroscopy. In addition to unsupervised classification on resultant infrared (IR) spectra using principal component analysis (PCA), a range of feature selection/extraction algorithms were tested. Following preprocessing, the data were split between training (70% of samples, 22 lung-cancer positive versus 664 other) and test (30% of samples, 9 lung-cancer positive versus 284 other) sets. The training set was used for model construction and the test set was used for validation. The best model was the PCA-quadratic discriminant analysis (QDA) algorithm. This PCA-QDA model was built using 8 PCs (90.4% of explained variance) and resulted in 93% accuracy for training and 91% for testing, with clinical sensitivity at 100% and specificity at 91%. Additionally, for prostate cancer patients amongst the male cohort (n = 585), following preprocessing, the data were split between training (70% of samples, 12 prostate-cancer positive versus 399 other) and test (30% of samples, 5 prostate-cancer positive versus 171 other) sets. A PCA-QDA model, again the best model, was built using 5 PCs (84.2% of explained variance) and resulted in 97% accuracy for training and 93% for testing, with clinical sensitivity at 100% and specificity at 92%. These results point to a powerful new approach towards the capability to screen large cohorts of individuals in primary care settings for underlying malignant disease.
A Preliminary Study on the Meaning of Inflammatory Indexes in MS: A Neda-Based Approach
Authors: Bunul Sena Destan , Alagoz Aybala Neslihan , Piri Cinar Bilge , Bunul Fatih , Erdogan Seyma , Efendi Husnu
Published: October 2023

Background: Multiple sclerosis (MS) is a disease of the central nervous system characterized by inflammation, demyelination, and axonal degeneration. This study aimed to investigate the relationship between inflammatory indexes and MS disease activity and progression. Methods: A prospective cohort study was conducted at the Kocaeli University Neurology Clinic, involving 108 patients diagnosed with MS. Data related to patient demographics, clinical presentations, radiological findings, and laboratory results were recorded. Inflammatory markers such as NLR (neutrophil-to-lymphocyte ratio), PLR (platelet-to-lymphocyte ratio), MLR (monocyte-to-lymphocyte ratio), and indexes such as SII (systemic immune inflammation index), SIRI (systemic immune response index), and AISI (systemic total aggregation index) were examined to determine their correlation with MS disease activity and disability. When assessing the influence of SII, AISI, and SIRI in predicting NEDA, it was found that all three indexes significantly predict NEDA. All indexes demonstrated a significant relationship with the EDSS score. Notably, SII, SIRI, and AISI were significant predictors of NEDA, and all inflammatory indexes showed a strong intercorrelation. This study investigates the role of inflammation markers in MS patients. It suggests that one or more of these non-invasive, straightforward, and practical markers could complement clinical and radiological parameters in monitoring MS.
CMV and HIV Coinfection in Women from a Region in Eastern Europe
Authors: Halichidis Stela , Aschie Mariana , Cozaru Georgeta Camelia , Manea Mihaela , Dobrin Nicolae , Vlad Sabina E. , Matei Elena , Baltatescu Gabriela Izabela , Mitroi Anca Florentina , Rosu Mihai Catalin , Nitu Bogdan Florentin , Resul Ghiulendan , Nicolau Anca Antonela , Cretu Ana Maria , Chisoi Anca
Published: October 2023

(1) Background: Human cytomegalovirus (CMV) infection is one of the most frequent opportunistic infections in immunosuppressed patients. Romania has one of the highest incidences of patients living with human immunodeficiency virus (HIV) which determines an immunosuppressive state. The aim of this study was to establish the prevalence of CMV infection among women living with HIV in Southeastern Romania and also to evaluate and correlate antiretroviral therapy (ART) with CD4 level and CMV disease evolution. (2) Methods: Seventy women living with HIV from Southeastern Romania were screened for CMV infection using antigen quantification. Of these, 50 were included in the study. First, the patients filled out a questionnaire regarding social conditions and other associated diseases. Then, we explored the statistical correlations between the data and HIV status, CD4+ cell counts, viral load, and antiretroviral therapy (ART). (3) Results: Median age of the patients was 33 years. Twenty-nine cases were diagnosed with HIV after sexual life beginning and 21 before. Most of the patients had a CD4 level over 200 cells/µL. ART duration in the CD4 under 200 cells/µL group was a bit longer than that in the CD4 over 200 cells/µL group. Forty-one patients had undetectable viremia. CD4 average value in the lot of patients with undetectable viremia was 704.71 cells/µL and in the lot with detectable viremia was 452.44 cells/µL. Viremia values correlated negatively with CD4 level. A positive correlation between IgG CMV values and ART therapy length was identified. A negative significant correlation between values of IgG CMV and values of CD4 was identified. CD4 value correlated negatively with IgG CMV values and with CMV avidity. (4) Conclusions: IgG CMV values had a weak positive correlation with ART therapy length, and a negative statistically significant correlation with values of CD4. CMV avidity has a negative correlation with CD4 value.
The Impact of Rural Credit on Cultivated Land Use Efficiency: An Empirical Analysis Using China Rural Revitalization Survey Data
Authors: Lu Mengna , Qi Yuan , Zhang Jiaqing , Zhu Daolin
Published: October 2023

Insufficient capital investment coupled with limited land resources significantly limits cultivated land use efficiency (CLUE). China’s rural credit policy system is currently growing, yet the impact of farmer-level credit on CLUE remains understudied. Therefore, this study investigated whether rural credit enhances CLUE by using the China Rural Revitalization Survey (CRRS) data. It explored the impact and mechanism of rural credit on CLUE using least squares regression and mediation models. According to our results, the average CLUE level for farmers in the study area was 0.661, which still had much room for improvement compared with Japan, which also has a large population but limited land. In addition, access to rural credit positively affected CLUE, with cultivated land scale-up and technological applications mediating the rural-credit-driven increase in CLUE. Further analyses of the rural credit allocation mode (RCAM) indicated that farmers’ use of credit for investment in agricultural production factors boosted CLUE more than non-farming allocation of credit funds. These findings suggest that the government should continue to increase support for rural credit while improving the monitoring mechanism for credit allocation to prevent rural credit de-farming from hindering CLUE improvement.
Correction: Díaz-Diego et al. The Last Attempt at Land Reform in Spain: Application and Scope of the Andalusian Agrarian Reform, 1984–2011. Land 2023, 12, 683
Authors: Díaz-Diego José , Jurado-Almonte José Manuel , Márquez-Domínguez Juan Antonio
Published: October 2023

In the original publication [...]
Long-Term Clinical Impact of Patients with Multi-Vessel Non-Obstructive Coronary Artery Disease
Authors: Jung Jin , Lee Su-Nam , Her Sung-Ho , Yoo Ki-Dong , Moon Keon-Woong , Moon Donggyu , Jang Won-Young
Published: October 2023

Background: Non-obstructive coronary artery disease (CAD) is a disease commonly diagnosed in patients undergoing coronary angiography. However, little is known regarding the long-term clinical impact of multi-vessel non-obstructive CAD. Therefore, the object of this study was to investigate the long-term clinical impact of multi-vessel non-obstructive CAD. Method: A total of 2083 patients without revascularization history and obstructive CAD were enrolled between January 2010 and December 2015. They were classified into four groups according to number of vessels involved in non-obstructive CAD (25% ≤ luminal stenosis < 70%): zero, one, two, or three diseased vessels (DVs). We monitored the patients for 5 years. The primary outcome was major cardiovascular and cerebrovascular events (MACCEs), defined as a composite of cardiac death, stroke, and myocardial infarction (MI). Result: The occurrence of MACCEs increased as the number of non-obstructive DVs increased, and was especially high in patients with three DVs. After adjustment, patients with three DVs still showed significantly poorer clinical outcomes of MACCEs, stroke, and MI compared those with zero DVs. Conclusion: Multi-vessel non-obstructive CAD, especially in patients with non-obstructive three DVs, is strongly associated with poor long-term clinical outcomes. This finding suggests that more intensive treatment may be required in this subset of patients.
Examining the Aryl Hydrocarbon Receptor Network in the Placental Tissues of Pregnancies Complicated by Pre-Eclampsia: An Explorative Case–Control Analysis
Authors: Xodo Serena , Londero Ambrogio P. , Orsaria Maria , Marzinotto Stefania , Colussi Gianluca , Cagnacci Angelo , Mariuzzi Laura , Gri Giorgia
Published: October 2023

Severe maternal and newborn morbidity and mortality associated with pre-eclampsia, which are caused partly by premature delivery, affect a factual proportion of pregnancies. Despite its prevalence, the underlying causes of pre-eclampsia remain elusive, with emerging evidence implicating the aryl hydrocarbon receptor (AhR) in its pathogenesis. This study sought to elucidate the involvement of the AhR and its associated pathway in pre-eclampsia by comparing placental components of the AhR pathway in pregnant individuals with and without pre-eclampsia. This case–control investigation was conducted at the University Hospital of Udine from May 2021 to February 2023. The AhR was assessed using immunohistochemistry and immunofluorescence, and its mRNA was evaluated using a Real-Time Quantitative Reverse Transcription PCR. Levels of mRNA expression were also estimated for other components of the AhR pathway (CYP1B1, IDO1, ARNT, TIPARP, S100A4, and AHRR). Our findings show decreased levels of expression of AhR, IDO1, ARNT, TiPARP, and S100A4 in the placental tissues of individuals with pre-eclampsia compared to controls (p < 0.05). The AhR exhibited a distinct localization within the syncytiotrophoblast (nuclei and cytoplasm) and CD45-positive cells (nuclei and cytoplasm). Furthermore, a significant positive correlation between the AhR and S100A4 (rho = 0.81) was observed in normal placentas, while CYP1B1 displayed a significant negative correlation with the AhR (rho = −0.72), within addition to its negative correlation with TiPARP (rho = −0.83). This study illuminates pre-eclampsia’s molecular aberrations, suggesting new diagnostic, therapeutic, and mechanistic approaches. This study emphasizes the need for more research to validate and broaden these findings to improve the management of this complex pregnancy condition.
Investigation of the Cementing Efficiency of Fly Ash Activated by Microsilica in Low-Cement Concrete
Authors: Dvorkin Leonid , Zhitkovsky Vadim , Lapovskaya Svetlana , Ribakov Yuri
Published: October 2023

This paper presents experimental results on the influence of concrete composition factors on the criterion characterizing the ratio between the compressive strength of activated low-cement concrete and clinker consumption. The investigation was carried out using mathematical planning of the experiments. Experimental and statistical models describing the influence of the fly ash, activating additive (microsilica), consumption of cement and aggregates, as well as the superplasticizer on the strength of low-cement concrete under normal hardening conditions and after steaming were obtained. The values of the clinker efficiency criterion and the mineral additive cementing efficiency coefficient were calculated, and models of these parameters were obtained for the investigated concrete compositions. It was shown that the activating effect of microsilica yields an increase in ash cementing efficiency and clinker efficiency criterion in concrete. Using the obtained models, an example for calculating the ash cementing efficiency coefficient is given.
Mechanical and Biological Properties of Titanium and Its Alloys for Oral Implant with Preparation Techniques: A Review
Authors: Wu Haochen , Chen Xiaohong , Kong Linghui , Liu Ping
Published: October 2023

Dental implants have revolutionised restorative dentistry, offering patients a natural-looking and durable solution to replace missing or severely damaged teeth. Titanium and its alloys have emerged as the gold standard among the various materials available due to their exceptional properties. One of the critical advantages of titanium and its alloys is their remarkable biocompatibility which ensures minimal adverse reactions within the human body. Furthermore, they exhibit outstanding corrosion resistance ensuring the longevity of the implant. Their mechanical properties, including hardness, tensile strength, yield strength, and fatigue strength, align perfectly with the demanding requirements of dental implants, guaranteeing the restoration’s functionality and durability. This narrative review aims to provide a comprehensive understanding of the manufacturing techniques employed for titanium and its alloy dental implants while shedding light on their intrinsic properties. It also presents crucial proof-of-concept examples, offering tangible evidence of these materials’ effectiveness in clinical applications. However, despite their numerous advantages, certain limitations still exist necessitating ongoing research and development efforts. This review will briefly touch upon these restrictions and explore the evolving trends likely to shape the future of titanium and its alloy dental implants.
Physical and Mechanical Effects of Silica Sand in Cement Mortars: Experimental and Statistical Modeling
Authors: Douadi Abdellah , Hebbache Kamel , Boutlikht Mourad , Tabchouche Seifeddine , Belebchouche Cherif , Hammouche Redha , Del Serrone Giulia , Moretti Laura
Published: October 2023

The environmental impacts of cement manufacturing are becoming a real-time issue that requires attention. This paper investigates the mechanical and physical properties of mortars with finely ground sand as a substitute for cement. The experimental program consisted of three silica sands with a Blaine Specific Surface (BSS) area of 459 m2/kg, 497 m2/kg, and 543 m2/kg and four substitution ratios of 10%, 20%, 30%, and 40%. A total of 12 mixtures have been prepared and tested for comparison to the reference mortar. The pozzolanic effect of the sand was evaluated using thermogravimetric analysis (TGA). The results revealed that the fineness variation from 459 m2/kg to 543 m2/kg resulted in an increase of 20% and 30% in water absorption and compressive strength, respectively. However, increasing the substitution ratio from 10% to 40% led to a 40% decrease in mechanical strength and a 25% increase in water absorption. The statistical analysis of the results demonstrated that both factors under study influenced compressive strength and water absorption. The ANalysis of VAriance (ANOVA) confirmed that the proposed regression equations predict the experimental results. Further studies will investigate both the technical and environmental performances of cement mortars with finely ground silica sand.
Nanostructure Effect on Magnetization Processes in FePt Polytwin Crystals
Authors: Yi Jingwei , Xu Xinyu , Yue Wenqin , Liu Feiyang , Hu Jingzhi , Geng Liwei D.
Published: October 2023

In FePt polytwin crystals with large magnetocrystalline anisotropy, the boundaries may play a crucial role in the magnetization processes occurring under an external magnetic field. In this study, we employed phase-field modeling and computer simulations to systematically investigate the effect of three types of polytwin boundaries—namely, symmetric (Type I), asymmetric (Type II), and mixed (Type III) boundaries—on magnetization processes as well as coercive fields under an external magnetic field along various directions. Because of the large anisotropy of FePt, the domain wall motion mechanism is usually dominant in the domain switching processes, while the magnetization rotation mechanism only becomes important at the late magnetization stage under a high external magnetic field. Among these three types of polytwin boundaries, the low coercivity is mainly due to the domain wall motion process, which starts from the intersection point at the polytwin boundary. The coercive field for the mixed polytwin boundary (Type III) is always in between the values of Type I and II.
Geometric Conformability of 3D Concrete Printing Mixtures from a Rheological Perspective
Authors: Miranda Luiza R. M. de , Jovanović Balša , Lesage Karel , De Schutter Geert
Published: October 2023

The effectiveness of 3D concrete printing (3DCP) relies on understanding the rheological properties of cementitious materials and their time-dependent evolution. These materials exhibit shear-thinning viscosity, an elastic region, and both static and dynamic yield stress, which are challenging to balance in 3DCP. Layer deformation can be caused by factors such as self-weight, the weight of subsequently deposited layers, and the stress induced by the nozzle pressing. Starting at the level of a single filament, the final geometrical conformity of a 3D-printed object is the sum of individual filament conformities. Hence, the control of layer deformation during the printing process is critical. The failure of 3D-printed objects can occur due to two primary mechanisms: material failure, which occurs when the material’s strength is exceeded, resulting in fracture or uncontrolled deformation; and stability failure, where the object cannot retain equilibrium of forces. These mechanisms often interact; extensive deformations resulting from material failure can lead to stability loss, or conversely, stability loss generates local excessive stresses leading to material failure. The governing mechanism depends on various factors, including material and process characteristics, as well as the transient nature of material properties, print strategy, and object design. With this in mind, this research aimed to broaden the understanding of the connection between rheological material properties—primarily yield stress—and the geometric conformability of printed objects. Experimental tests were conducted on pastes using a rheometer, and correlated mortars, allowing for the evaluation of realistic extrusion properties.
Explainable Stacked Ensemble Deep Learning (SEDL) Framework to Determine Cause of Death from Verbal Autopsies
Authors: Mapundu Michael T. , Kabudula Chodziwadziwa W. , Musenge Eustasius , Olago Victor , Celik Turgay
Published: October 2023

Verbal autopsies (VA) are commonly used in Low- and Medium-Income Countries (LMIC) to determine cause of death (CoD) where death occurs outside clinical settings, with the most commonly used international gold standard being physician medical certification. Interviewers elicit information from relatives of the deceased, regarding circumstances and events that might have led to death. This information is stored in textual format as VA narratives. The narratives entail detailed information that can be used to determine CoD. However, this approach still remains a manual task that is costly, inconsistent, time-consuming and subjective (prone to errors), amongst many drawbacks. As such, this negatively affects the VA reporting process, despite it being vital for strengthening health priorities and informing civil registration systems. Therefore, this study seeks to close this gap by applying novel deep learning (DL) interpretable approaches for reviewing VA narratives and generate CoD prediction in a timely, easily interpretable, cost-effective and error-free way. We validate our DL models using optimisation and performance accuracy machine learning (ML) curves as a function of training samples. We report on validation with training set accuracy (LSTM = 76.11%, CNN = 76.35%, and SEDL = 82.1%), validation accuracy (LSTM = 67.05%, CNN = 66.16%, and SEDL = 82%) and test set accuracy (LSTM = 67%, CNN = 66.2%, and SEDL = 82%) for our models. Furthermore, we also present Local Interpretable Model-agnostic Explanations (LIME) for ease of interpretability of the results, thereby building trust in the use of machines in healthcare. We presented robust deep learning methods to determine CoD from VAs, with the stacked ensemble deep learning (SEDL) approaches performing optimally and better than Long Short-Term Memory (LSTM) and Convolutional Neural Network (CNN). Our empirical results suggest that ensemble DL methods may be integrated in the CoD process to help experts get to a diagnosis. Ultimately, this will reduce the turnaround time needed by physicians to go through the narratives in order to be able to give an appropriate diagnosis, cut costs and minimise errors. This study was limited by the number of samples needed for training our models and the high levels of lexical variability in the words used in our textual information.
How Lung Volume Recruitment Maneuvers Enhance Respiratory Function in Multiple Sclerosis Patients: A Quasi-Randomized Pilot Study
Authors: Enrichi Claudia , Regazzetti Martina , Cieślik Błażej , Zanetti Cristiano , D’Imperio Daniela , Compagno Elisa , Cacciante Luisa , Federico Sara , Pregnolato Giorgia , Zitti Mirko , Kiper Pawel
Published: October 2023

Background and Objectives: In patients with multiple sclerosis (MS), a decrease in muscle strength can lead to limitations in pulmonary functions, potentially causing respiratory complications. To address these challenges, the lung volume recruitment (LVR) maneuver has emerged as a potential intervention. This study sought to evaluate the impact of a four-week LVR protocol on respiratory function in secondary progressive MS patients. Materials and Methods: In a quasi-randomized pre/post-controlled trial, 24 patients with secondary progressive MS were recruited. Participants aged 20–70 years with an EDSS score of 2 to 9 were alternately allocated to intervention (n = 12) or control groups (n = 12). The intervention group underwent a 4-week respiratory rehabilitation training focused on LVR, using a standardized cough machine treatment protocol twice daily. The control group received no respiratory intervention. Outcomes measured included forced vital capacity (FVC), maximal insufflation capacity (MIC), and peak cough flow (PCF), using turbine spirometry and other associated equipment. All measurements were taken at baseline (T0) and after 4 weeks (T1) by a blinded assessor. Results: For the intervention group, the mean difference pre/post-treatment in MIC (mL) was 0.45 (SD 1.13) (p = 0.02), and in MIC (%), it was 0.13 (SD 0.24) (p = 0.03). Compared to the control group (n = 10), the between-group mean difference for MIC (mL) was 0.54 (p = 0.02), and for MIC (%), it was 0.15 (p = 0.02). Conclusions: The short-term daily LVR protocol notably improved passive lung capacity, despite minimal changes in active lung capacity or cough force. The LVR maneuver offers promise for enhancing respiratory function, especially passive lung capacity, in secondary progressive MS patients. Further research should explore optimal treatment durations and frequencies for more extensive respiratory gains.
Oxyanion Removal from Impaired Water by Donnan Dialysis Plug Flow Contactors
Authors: Fox Shalom , Stadnik Kristina , Thakur Amit K. , Farkash Lior , Ronen Zeev , Oren Yoram , Gilron Jack
Published: October 2023

In the last twenty-five years, extensive work has been done on ion exchange membrane bioreactors (IEMB) combining Donnan dialysis and anaerobic reduction to remove trace oxyanions (e.g., perchlorate, nitrate, chlorate, arsenate) from contaminated water sources. Most studies used Donnan dialysis contactors with high recirculation rates on the feed side, so under continuous operation, the effective concentration on the feed side of the membrane is the same as the exit concentration (CSTR mode). We have built, characterized, and modelled a plug flow Donnan dialysis contactor (PFR) that maximizes concentration on the feed side and operated it on feed solutions spiked with perchlorate and nitrate ion using ACS and PCA-100 anion exchange membranes. At identical feed inlet concentrations with the ACS membrane, membrane area loading rates are three-fold greater, and fluxes are more than double in the PFR contactor than in the CSTR contactor. A model based on the nonlinear adsorption of perchlorate in ACS membrane correctly predicted the trace ion concentration as a function of space-time in experiments with ACS. For PCA membrane, a linear flux dependence on feed concentration correctly described trace ion feed concentration as a function of space-time. Anion permeability for PCA-100 was high enough that the overall mass transfer was affected by the film boundary layer resistance. These results provide a basis for efficiently scaling up Donnan dialysis contactors and incorporating them in full-scale IEMB setups.
Low-Speed Impact and Residual Mechanical Performance of the BR1200HS/AA6082 Self-Piercing Riveted Joints
Authors: Jia Ying-Lian , Huang Zhi-Chao , Jiang Yu-Qiang
Published: October 2023

To investigate the low-speed impact response of the BR1200HS steel and AA6082 aluminum alloy self-piercing riveted (SPR) joint, low-speed impact tests with impact energies of 2.5 J, 5.0 J, 7.5 J, 10.0 J, 12.5 J, 15.0 J, 20.0 J, and 30.0 J were conducted utilizing a drop hammer impact tester. The results show that with the increased impact energy, the visual breakages of the SPR joints become more severe. The maximum impact energy the joints can sustain ranges from 10.0 J to 12.5 J. When the impact energy is less than 12.5 J, the contact force/energy–time curves show similar variations. Moreover, as the impact energy increases, total uptake energy value (Et), maximum uptake energy value (Ef), and maximum contact force (Fm) of the joints increase gradually. The low-speed impact energy has little effect on the maximum static tensile force of the impacted joints. However, the residual energy values decrease with the increase in impact energy. The tensile failure form of the joints is the pulling out of the rivets from the lower plates, and the low-speed impacts have no significant effect on the tensile failure form of the joints.
Influence of Alternative Hard and Binder Phase Compositions in Hardmetals on Thermophysical and Mechanical Properties
Authors: Hering Benjamin , Gestrich Tim , Steinborn Clemens , Vornberger Anne , Pötschke Johannes
Published: October 2023

Due to the classification of Co as a CMR (carcinogenic, mutagenic, toxic to reproduction) as well as the classification of both Co and WC as CRM (critical raw materials) more and more research is being carried out to investigate possible substitutes for WC-Co hardmetals. To directly compare their microstructure as well as mechanical and thermophysical properties, five very different hardmetals were investigated. For this purpose, the compositions WC-Co, WC-FeNiMn, WC-HEA, NbC-Co and HEC-Co were selected in order to investigate alternative binders for cobalt as well as different alternative hard phases for WC. The results of the hardness measurements showed that for the hardmetals with alternative binders (WC-FeNiMn and WC-HEA) hardness values of 1327 HV10 and 1299 HV10 comparable to WC-Co with 1323 HV10 can be achieved. When WC is replaced by HEC as the hard phase, a significantly higher hardness of 1543 HV10 can be obtained, demonstrating the great potential of high-entropy carbides. Furthermore, the hot hardness measurements between RT and 900 °C showed significantly higher values (up to approx. 290 HV10) for the WC-HEA and HEC-Co hardmetals compared to those of WC-Co. However, the fracture toughness of the alternative hardmetals was lower compared to that of conventional WC-Co hardmetals. In terms of thermophysical properties, the results of the hardmetals with alternative binders were close to those of WC-Co. Thus, it can be shown that it is possible to produce alternative hardmetals with comparable properties to WC-Co and that with further optimization they show great potential to replace WC-Co in the near future.
Enhancing Linearity in Parallel-Plate MEMS Varactors through Repulsive Actuation
Authors: Bensalem Roufaida , Elsayed Mohannad Y. , Tawfik Hani H. , Nabki Frederic , El-Gamal Mourad N.
Published: October 2023

This paper presents a new MEMS varactor that uses repulsive actuation to achieve an ultra-linear capacitance-to-voltage response. The approach proposed involves actuating the moveable electrode away from the fixed electrode, instead of the conventional closing-the-gap direction. This increasing-gap movement reduces the capacitance as the actuation voltage increases. The MEMS variable capacitor is fabricated using PolyMUMPs technology and exhibits an excellent linearity factor of 99.7% in capacitance-to-voltage response, and a capacitance tuning ratio of 11× was achieved. The proposed strategy will enable the development of high-performance MEMS-based tunable devices for various applications.
The Stability of Dams with Different Stoping Elevations in the Tongling Valley-Type Tailings Impoundment: A Case Study in Yunnan China
Authors: Pan Yiwen , Chen Jianping , Zuo Xiaohuan , Zhang Cheng , Wu Shuangshuang
Published: October 2023

Significant interest has been focused on recovery rates, recovery options, and recovery utilization when tailings impoundments are re-mined. However, the stability of the tailings dams during the recovery process is also a severe issue. Based on engineering geological surveys and laboratory tests, the evolution of the Tongling tailings impoundment’s instability characteristics under different recovery heights and diverse working conditions was analyzed by numerical simulation. Firstly, with the help of 2D software, the position of the tailings dam infiltration line and the alteration of the dam safety factor during the stoping process were calculated. Secondly, 3Dmine (2017) software was used to create the 3D surface structure of the tailings impoundment, and then a 3D numerical analysis model was established by means of Midas GTS NX software. The numerical simulation of seepage and stress analyses were conducted based on the model. Consequently, the evolution of the stability characteristics of tailings dam under different operating conditions was calculated. The research demonstrates that the dry beach length of the tailings pond gradually reduces with a decrease in the extraction height, resulting in a lower infiltration line. Under flood conditions, the saturation line has partial overflow due to the poor seepage discharge capacity of the dam. The total displacement of the dam body is inversely proportional to the retrieval height. The more extreme the analyzed working conditions, the more the safety factor will be reduced. Additionally, the plastic variation area of the dam body will be more comprehensive, which will increase the risk of a dam collapse.
Magmatic–Hydrothermal Origin of Fe-Mn Deposits in the Lesser Khingan Range (Russian Far East): Petrographic, Mineralogical and Geochemical Evidence
Authors: Berdnikov Nikolai , Kepezhinskas Pavel , Nevstruev Victor , Krutikova Valeria , Konovalova Natalia , Savatenkov Valery
Published: October 2023

Iron and iron–manganese deposits form three closely spaced clusters within the Lesser Khingan Range of the Russian Far East. Fe-Mn mineralization is hosted in Vendian–Cambrian carbonates and composed of magnetite, hematite, braunite, haussmanite, rhodochrosite and pyrolusite. The iron–manganese ores are closely associated with explosive intermediate–felsic breccias, magnetite-rich lavas, dolerites and mineralized lithocrystalloclastic tuffs. Magmatic rocks display both concordant and discordant relationships with Fe-Mn mineralization and contain abundant xenoliths of host carbonates. Both magmatic rocks (with the exception of Nb-enriched dolerites) and Fe-Mn ores are characterized by variable enrichments in large-ion lithophile and light rare earth elements and strong depletions in high-field strength elements compatible with the broad subduction setting for explosive volcanism and associated hydrothermal Fe-Mn ore mineralization. Nd-Sr isotope systematics suggest contamination by both ancient and juvenile continental crust and the involvement of recycled pelagic sediment in the formation of Fe-Mn deposits in the Lesser Khingan Range of the Russian Far East.
A Review of Foods of Plant Origin as Sources of Vitamins with Proven Activity in Oxidative Stress Prevention according to EFSA Scientific Evidence
Authors: Ciudad-Mulero María , Domínguez Laura , Morales Patricia , Fernández-Ruiz Virginia , Cámara Montaña
Published: October 2023

Beyond their nutritional benefits, vitamins could decrease the risk of chronic diseases due to their potent antioxidant capacity. The present work is aimed at reviewing the state of the art regarding (1) the vitamins involved in oxidative stress prevention in accordance with the requirements established by the European Food Safety Authority (EFSA) and (2) the foods of plant origin that are sources of those vitamins and have potential benefits against oxidative stress in humans. According to the European regulations based on EFSA scientific evidence, riboflavin, vitamin C, and vitamin E are those vitamins subjected to the approved health claim “contribute to the protection of cells from oxidative stress”. Scientific studies conducted in humans with some natural food sources of riboflavin (almonds, wheat germ, mushrooms, oat bran), vitamin C (guava, kale, black currant, Brussels sprouts, broccoli, orange), and vitamin E (hazelnuts, almonds, peanuts, pistachio nuts, extra virgin olive oil, dates, rye) have been performed and published in the literature. However, no food of plant origin has obtained a favorable EFSA opinion to substantiate the approval of health claims related to its potential properties related to oxidative stress prevention. Further studies (concretely, well-controlled human intervention studies) must be carried out in accordance with EFSA requirements to provide the highest level of scientific evidence that could demonstrate the potential relationship between foods of plant origin and antioxidant capacity. This review could be useful for the scientific community to study the application of health claims referring to the antioxidant capacity potentially exerted by foods of plant origin.
A Norbornadiene-Based Molecular System for the Storage of Solar–Thermal Energy in an Aqueous Solution: Study of the Heat-Release Process Triggered by a Co(II)-Complex
Authors: Castro Franco , Gancheff Jorge S. , Ramos Juan C. , Seoane Gustavo , Bazzicalupi Carla , Bianchi Antonio , Ridi Francesca , Savastano Matteo
Published: October 2023

It is urgent yet challenging to develop new environmentally friendly and cost-effective sources of energy. Molecular solar thermal (MOST) systems for energy capture and storage are a promising option. With this in mind, we have prepared a new water-soluble (pH > 6) norbornadiene derivative (HNBD1) whose MOST properties are reported here. HNBD1 shows a better matching to the solar spectrum compared to unmodified norbornadiene, with an onset absorbance of λonset = 364 nm. The corresponding quadricyclane photoisomer (HQC1) is quantitatively generated through the light irradiation of HNBD1. In an alkaline aqueous solution, the MOST system consists of the NBD1−/QC1− pair of deprotonated species. QC1− is very stable toward thermal back-conversion to NBD1−; it is absolutely stable at 298 K for three months and shows a marked resistance to temperature increase (half-life t½ = 587 h at 371 K). Yet, it rapidly (t½ = 11 min) releases the stored energy in the presence of the Co(II) porphyrin catalyst Co-TPPC (ΔHstorage = 65(2) kJ∙mol−1). Under the explored conditions, Co-TPPC maintains its catalytic activity for at least 200 turnovers. These results are very promising for the creation of MOST systems that work in water, a very interesting solvent for environmental sustainability, and offer a strong incentive to continue research towards this goal.
Improving the Activity of Tryptophan Synthetase via a Nucleic Acid Scaffold
Authors: Wang Yaping , Wang Xiangyi , Niu Shuhui , Cheng Wei , Liu Xiaoyan , Min Yong , Qiu Yimin , Ma Lixin , Rao Ben , Zhu Lei
Published: October 2023

Tryptophan synthetase (TSase), which functions as a tetramer, is a typical enzyme with a substrate channel effect, and shows excellent performance in the production of non-standard amino acids, histamine, and other biological derivatives. Based on previous work, we fused a mutant CE protein (colistin of E. coli, a polypeptide with antibacterial activity) sequence with the sequence of TSase to explore whether its catalytic activity could be enhanced, and we also analyzed whether the addition of a DNA scaffold was a feasible strategy. Here, dCE (CE protein without DNase activity) protein tags were constructed and fused to the TrapA and TrapB subunits of TSase, and the whole cell was used for the catalytic reaction. The results showed that after the dCE protein tag was fused to the TrapB subunit, its whole cell catalytic activity increased by 50%. Next, the two subunits were expressed separately, and the proteins were bound in vitro to ensure equimolar combination between the two subunits. After the dCE label was fused to TrapB, the activity of TSase assembled with TrapA also improved. A series of experiments revealed that the enzyme fused with dCE9 showed higher activity than the wild-type protein. In general, the activity of assembly TSase was optimal when the temperature was 50 °C and the pH was about 9.0. After a long temperature treatment, the enzyme maintained good activity. With the addition of exogenous nucleic acid, the activity of the enzyme increased. The maximum yield was 0.58 g/L, which was almost three times that of the wild-type TSase (0.21 g/L). The recombinant TSase constructed in this study with dCE fusion had the advantages of higher heat resistance and higher activity, and confirmed the feasibility of adding a nucleic acid scaffold, providing a new idea for the improvement of structurally similar enzymes.
Seasonal Variability of Volatile Components in Calypogeia integristipula
Authors: Wawrzyniak Rafał , Guzowska Małgorzata , Wasiak Wiesław , Jasiewicz Beata , Bączkiewicz Alina , Buczkowska Katarzyna
Published: October 2023

Liverworts contain a large number of biologically active compounds that are synthesised and stored in their oil bodies. However, knowledge about the chemical composition of individual species is still incomplete. The subject of the study was Calypogeia integristipula, a species representing leafy liverworts. Plant material for chemotaxonomic studies was collected from various locations in Poland. The chemical composition was determined in 74 samples collected from the natural environment in 2021 and 2022 in three growing seasons: spring, summer and autumn, and for comparison with samples originating from in vitro culture. The plants were classified as Calypogeia integristipula on the basis of morphological characteristics, oil bodies, and DNA markers. The volatile organic compounds (VOCs) from the biological material were extracted by headspace solid phase microextraction (HS-SPME). The samples were then analysed by gas chromatography–mass spectrometry (GC-MS). A total of 79 compounds were detected, of which 44 compounds were identified. The remaining compounds were described using the MS fragmentation spectrum. Cyclical changes in the composition of compounds associated with the growing season of Calypogeia integristipula were observed. Moreover, samples from in vitro culture and samples taken from the natural environment were shown to differ in the composition of chemical compounds. In terms of quantity, among the volatile compounds, compounds belonging to the sesquiterpene group (46.54–71.19%) and sesqiuterpenoid (8.12–22.11%) dominate. A smaller number of compounds belong to aromatic compounds (2.30–10.96%), monoterpenes (0.01–0.07%), monoterpenoids (0.02–0.33%), and aliphatic hydrocarbons (1.11–6.12%). The dominant compounds in the analysed liverworts were: anastreptene (15.27–31.14%); bicyclogermacrene (6.99–18.09%), 4,5,9,10-dehydro-isolongifolene (2.00–8.72%), palustrol (4.95–9.94%), spathulenol (0.44–5.11%).
Nature-Inspired Biomolecular Corona Based on Poly(caffeic acid) as a Low Potential and Time-Stable Glucose Biosensor
Authors: Kuznowicz Maria , Jędrzak Artur , Jesionowski Teofil
Published: October 2023

Herein, we present a novel biosensor based on nature-inspired poly(caffeic acid) (PCA) grafted to magnetite (Fe3O4) nanoparticles with glucose oxidase (GOx) from Aspergillus niger via adsorption technique. The biomolecular corona was applied to the fabrication of a biosensor system with a screen-printed electrode (SPE). The obtained results indicated the operation of the system at a low potential (0.1 V). Then, amperometric measurements were performed to optimize conditions like various pH and temperatures. The SPE/Fe3O4@PCA-GOx biosensor presented a linear range from 0.05 mM to 25.0 mM, with a sensitivity of 1198.0 μA mM−1 cm−2 and a limit of detection of 5.23 μM, which was compared to other biosensors presented in the literature. The proposed system was selective towards various interferents (maltose, saccharose, fructose, L-cysteine, uric acid, dopamine and ascorbic acid) and shows high recovery in relation to tests on real samples, up to 10 months of work stability. Moreover, the Fe3O4@PCA-GOx biomolecular corona has been characterized using various techniques such as Fourier transform infrared spectroscopy (FTIR), high-resolution transmission electron microscopy (HRTEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Bradford assay.
Exploring the Potential of Heteroatom-Doped Graphene Nanoribbons as a Catalyst for Oxygen Reduction
Authors: Cardoso Eduardo S. F. , Fortunato Guilherme V. , Rodrigues Clauber D. , Lanza Marcos R. V. , Maia Gilberto
Published: October 2023

In this study, we created a series of N, S, and P-doped and co-doped carbon catalysts using a single graphene nanoribbon (GNR) matrix and thoroughly evaluated the impact of doping on ORR activity and selectivity in acidic, neutral, and alkaline conditions. The results obtained showed no significant changes in the GNR structure after the doping process, though changes were observed in the surface chemistry in view of the heteroatom insertion and oxygen depletion. Of all the dopants investigated, nitrogen (mainly in the form of pyrrolic-N and graphitic-N) was the most easily inserted and detected in the carbon matrix. The electrochemical analyses conducted showed that doping impacted the performance of the catalyst in ORR through changes in the chemical composition of the catalyst, as well as in the double-layer capacitance and electrochemically accessible surface area. In terms of selectivity, GNR doped with phosphorus and sulfur favored the 2e− ORR pathway, while nitrogen favored the 4e− ORR pathway. These findings can provide useful insights into the design of more efficient and versatile catalytic materials for ORR in different electrolyte solutions, based on functionalized carbon.