Search Results (29)

This study assessed the repair shear bond strength (SBS; MPa) and surface roughness (Ra; μm) of aged hybrid ceramic (Cerasmart270, GC) and nano-hybrid ceramic (Grandio Blocs, Voco) CAD/CAM blocks after different surface pretreatment methods. In this study, 2 mm thick Cerasmart270 and Grandio Blocs were cut into slabs (Isomet; n = 80 per group). Following aging for six months, the specimens in each CAD/CAM material were randomly divided into four groups (n: 20 each) according to the surface pretreatments: control (no pretreatment), Er:YAG laser, sandblasting, and bur grinding. A total of 10 specimens in each CAD/CAM material pretreatment group were used for Ra evaluation (Perthometer Mahr), while the other 10 were for SBS. After the application of a silane primer (G-Multi Primer, GC) and universal adhesive (G2-Bond, GC), composite build-ups (Filtek Z250; 3MESPE) were performed for the SBS evaluation. After storage in distilled water for 24 h, SBS was evaluated with a universal testing machine (Instron). SBS and Ra data were analyzed with two-way ANOVA and Tukey’s post hoc tests (p < 0.05). SBS was significantly affected by the surface pretreatment methods (p = 0.0001) and by the types of CAD/CAM material (p = 0.005). Bur grinding showed the highest SBS for both CAD/CAM materials, while the control groups yielded significantly lower SBS than bur grinding and sandblasting (p < 0.05). Er:YAG lasers did not significantly enhance the SBS compared to the control group. Sandblasting presented significantly higher SBS than lasers only in Grandio Blocs (p < 0.05). The surface pretreatment methods significantly influenced Ra (p = 0.0001); however, no significant interaction was found between the types of CAD/CAM material and the surface pretreatments (p > 0.05). Control groups exhibited, significantly, the lowest Ra for both materials (p = 0.0001), while no significant differences were observed between the other pretreatment methods. Bur grinding was identified as the most effective pretreatment method for repairing hybrid ceramic CAD/CAM materials. Full article

Hyperlipidemia is the root cause of numerous chronic conditions, leading to high mortality rates around the globe. Spirulina (Arthrospira platensis) microalgae serve as a promising reservoir of bioactive compounds with diverse pharmacological properties. The current study examined the nutritional profile of spirulina powder in relation to strict glycemic control, specifically focusing on its potential to lower lipid levels. In an in vivo investigation, normal healthy male Wistar albino rats (n = 60) were divided into two groups: a negative control group (NC) of ten rats and a high-fat diet group (n = 50) that were fed a cholesterol-rich diet until their cholesterol levels reached or exceeded 250 mg/dL. Subsequently, the hypercholesterolemic rats were then randomly allocated to several treatment groups: a positive control (PC); a standard treatment diet (STD) involving fenofibrate at a dose of 20 mg/kg body weight; and three experimental groups (T1, T2, and T3) that received spirulina powder supplementation at doses of 300, 600, and 900 mg per kg body weight, respectively, for the period of 12 weeks. Blood samples were analyzed for oxidative stress biomarkers, insulin levels, lipid profiles, liver function, and expression of gene levels in the diabetogenic pathway. The study utilized spectrophotometric colorimetric methods to identify oxidative stress biomarkers, serum kit methods to measure lipid profiles and liver enzymes, and the assessment of qPCR for mRNA quantity. According to the research findings, spirulina powder has certain noteworthy features. It had the greatest quantity of chlorogenic acid (4052.90 µg/g) among seven phenolics and two flavonoid compounds obtained by HPLC-UV analysis. Furthermore, the proximate analysis demonstrated that spirulina is high in protein (16.45 ± 0.8%) and has a significant energy yield of 269.51 K-calories per 100 g. A maximal spirulina dose of 900 mg/kg/wt significantly lowered oxidative stress, cholesterol, triglyceride, low-density lipoproteins (LDL), and insulin levels (p ≤ 0.05). In contrast, high-density lipoprotein (HDL) and total antioxidant capacity (TAC) levels increased significantly (p ≤ 0.05) compared to all other groups, except the NC group. The study provides remarkable proof about the pharmacological impact of spirulina powders. Significant reductions (p ≤ 0.05) in liver enzymes {alanine aminotransferase (ALT) and aspartate aminotransferase (AST)} were observed across all treatment groups, with the exception of the NC, compared to the positive control. The treatment groups had significantly greater gene expression levels of INS-1, PDX-1, IGF-1, and GLUT-2 than the positive control group (p ≤ 0.05). These findings highlight spirulina’s potential as a long-term regulator of hyperglycemia in rat models with induced hyperlipidemia, owing to its phenolic bioactive components that serve as antioxidants. Full article

Disabled people need to be activists given the many problematic lived realities they face. However, they frequently encounter obstacles in traditional offline activism. Online activism could be a potential alternative. The objective of this scoping review is to examine the extent and nature of the coverage of disabled people in the academic literature that focuses on online activism. We searched the abstracts in Scopus, Web of Science, and the 70 databases in EBSCO-HOST for the presence of 57 terms linked to online activism or online tools or places for online activism, which generated 18,069 abstracts for qualitative analysis. Of the 18,069 abstracts, only 54 discussed online the activism by disabled people. Among these 54 relevant abstracts, only one contained the term “Global South”. No relevant abstracts were found that contained the terms “Metaverse” or “Democrac*” together with “activis*”. Only two relevant abstracts contained the phrase “digital citizen*”. Out of the 57 terms, 28 had no hits. The thematic analysis identified 24 themes: 6 themes in 30 abstracts had a positive sentiment, 7 themes in 30 abstracts had a negative sentiment, and 11 themes present in 23 abstracts had a neutral sentiment. There were three main themes: the positive role and use of online activism; the technical accessibility barriers to online activism; and the attitudinal accessibility problems arising from ableist judgments. The intersectionality of the disability identity with other marginalized identities and the issue of empowerment were rarely addressed, and ability judgment-based concepts beyond the term’s “ableism” and “ableist” were not used. The study underscores the necessity for further research given the few relevant abstracts found. The study also indicates that actions are needed on barriers to online activism and that examples for best practices exist that could be applied more often. Future studies should also incorporate a broader range of ability judgment-based concepts to enrich the analysis and to support the empowerment of disabled activists. Full article

Surgery of the aortic arch remains a complex procedure, with neurological events such as stroke remaining its most dreaded complications. Changes in surgical technique and the continuous innovation in neuroprotective strategies have led to a significant decrease in cerebral and spinal events. Different modes of cerebral perfusion, varying grades of hypothermia, and a number of pharmacological strategies all aim to reduce hypoxic and ischemic cerebral injury, yet there is no evidence indicating the clear superiority of one method over another. While surgical results continue to improve, novel hybrid and interventional techniques are just entering the stage and the question of optimal neuroprotection remains up to date. Within this perspective statement, we want to shed light on the current evidence and controversies of cerebral protection in aortic arch surgery, as well as what is on the horizon in this fast-evolving field. We further present our institutional approach as a large tertiary aortic reference center. Full article

Objective: To determine the effect of grit-blasting before and after sintering on the surface roughness of zirconia and the micro-tensile bond strength of a pressable veneering ceramic to zirconia. Methods: Pre-sintered zirconia blocks (IPS e.max ZirCAD, Ivoclar) were divided into four test groups of three specimens each and a control group (‘CTR’; no surface treatment). Pre-S-30, Pre-S-50, and Pre-S-110 were grit-blasted with 30-µm SiO₂-coated Al₂O₃, 50-µm Al₂O₃ and 110-µm Al₂O₃ particles, respectively, before sintering. Post-S-30 was grit-blasted with 30-µm SiO₂-coated Al₂O₃ after sintering. For each treatment, the surface roughness was measured (Ra, Perthometer M4P, Mahr Perthen). After sintering the zirconia blocks, a liner was applied and a pressable ceramic (IPS e.max ZirPress, Ivoclar) was heat-pressed. Sixteen microbars were obtained from each block and submitted to micro-tensile bond-strength (µTBS) testing. Data were analyzed with one-way ANOVA. Any correlation between Ra and µTBS was evaluated (Sperman test). Results: Grit-blasting before sintering with 110-µm Al₂O₃ (Ra_Pre-S-110 = 3.4 ± 0.4 µm), 50-µm Al₂O₃ (Ra_Pre-S-50 = 2.3 ± 0.5 µm), and 30-µm SiO₂-coated Al₂O₃ (Ra_Pre-S-30 = 1.2 ± 0.2 µm) resulted in significantly higher roughness than grit-blasting after sintering with 30-µm SiO₂-coated Al₂O₃ (Ra_Post-S-30 = 0.5 ± 0.1 µm). The highest µTBS was measured when the sintered zirconia was grit-blasted with 30-μm SiO₂-coated Al₂O₃ (µTBS_Post-S-30 = 28.5 ± 12.6 MPa), which was significantly different from that of specimens that were grit-blasted before sintering (µTBS_Pre-S-30 = 21.8 ± 10.4; µTBS_Pre-S-50 = 24.1 ± 12.6; µTBS_Pre-S-110 = 26.4 ± 14.1) or were not grit-blasted (µTBS_CTR = 20.2 ± 11.2). Conclusions: Grit-blasting zirconia before sintering enhanced the surface roughness proportionally to the particle size of the sand used. Grit-blasting with 30-µm SiO₂-coated Al₂O₃ after sintering improved bonding of the veneering ceramic to zirconia. Clinical Significance: As grit-blasting with 30-µm SiO₂-coated Al₂O₃ after sintering improved bonding of the veneering ceramic to zirconia, it may reduce veneering ceramic fractures/chipping. Full article

Achieving a homogeneous and uniform powder bed surface as well as a defined, uniform layer thickness is crucial for achieving reproducible component properties that meet requirements when powder bed fusion of metals with a laser beam. The existing recoating processes cause wear of the recoater blade due to protruded, melted obstacles, which affects the powder bed surface quality locally. Impairments to the powder bed surface quality have a negative effect on the resulting component properties such as surface quality and relative density. This can lead either to scrapped components or to additional work steps such as surface reworking. In this work, an electric smoother is presented with which a wear-free and contactless smoothing of the powder bed can be realized. The achievable powder bed surface quality was analyzed using optical profilometry. It was found that the electric smoother can compensate for impairments in the powder bed surface and achieve a reproducible surface quality of the powder bed regardless of the initial extent of the impairments. Consequently, the electric smoother offers a promising opportunity to reduce the scrap rate in PBF-LB/M and to increase component quality. Full article

In line with the “beautiful-is-good” heuristic, numerous studies show that physically attractive individuals are perceived in a more positive light. However, building on previous findings suggesting that the “beauty–good” relationship is bidirectional, the present research investigates how information on a stigmatized attribute impacts attractiveness perceptions and social judgments. Within a controlled experimental design, we present evidence that the mere label of mental illness (i.e., schizophrenia) decreased the positivity of personality evaluations and perceived attractiveness of a male target that had previously been validated to be highly attractive. Consistent with the “good-is-beautiful” heuristic, a mental illness label led to decreased perceptions of attractiveness, which was mediated by the inference of less positive personality characteristics. This finding lends further support for the bidirectional nature of the “beauty–good” relationship and provides a valuable avenue for future research on the multifaceted ways in which the stigma of mental illness affects social perceptions. Full article

Electromobility promises to efficiently mitigate consequences of increasing traffic volume and its accompanied greenhouse gas emissions. On an individual level, electrified bikes allow emission free electrified mobility at moderate costs, and consequently their stock has increased significantly in recent years. This simultaneously increases the demand for spare parts, which are often manufacturer- or application-specific, and due to many variants, challenging to provide for the market. This article evaluates powder-based and extrusion-based metal additive manufacturing of a typical electrified bike component. The overarching objective is to establish a sustainable spare parts supply in the field of electromobility by manufacturing spare parts in a resource-efficient and decentralized manner. This approach aims to eliminate the need for physical storage space and long transport routes for the provision of spare parts, while significantly increasing the service life of e-bikes. The investigation demonstrates how these parts can be additively manufactured function equivalent and with sufficient mechanical properties, also taking economical aspects into account. Furthermore, the needed resources and related environmental consequences for metal-based additive manufacturing spare-part production are compared for both process routes. The results show that both routes are capable of producing spare-parts at comparatively the same mechanical performance, with the mechanical performance of the initial part clearly surpassed. Furthermore, it can be observed that both routes exhibit comparable resource costs, with the powder bed fusion of metals using laser beams showing significantly lower energy and gas costs by more than ten times, but higher material costs that are approximately twice as high as those of atomic diffusion additive manufacturing. Therefore, additive manufacturing offers a promising opportunity to rapidly produce parts in small quantities which are resource efficient. Full article

A synergistic multi-material flame retardant system based on expandable graphite (EG), aluminum diethylphosphinate (AlPi), melamine polyphosphate (MPP), and montmorillonite (MMT) has been studied in glass-fiber-reinforced polyamide 6 (PA6). Analytical evaluations and fire performances were evaluated using coupled thermogravimetric analysis (TGA) and Fourier-transform infrared spectroscopy (FTIR) as well as cone calorimetry, UL-94 fire testing, and limiting oxygen index (LOI). A combination of EG/AlPi/MPP/MMT has been shown to provide superior flame-retarding properties when integrated at 20 wt.% into glass-fiber-reinforced PA6 (25 wt.%), achieving UL-94 V0 classification and an oxygen index of 32%. Strong residue formation resulted in low heat development overall, with a peak heat release rate (pHRR) of 103 kW/m², a maximum of average heat release rate (MAHRE) of 33 kW/m², and deficient total smoke production (TSP) of 3.8 m². Particularly remarkable was the structural stability of the char residue. The char residue could easily withstand an areal weight of 35 g/cm², showing no visible deformation. Full article

This paper establishes a study for an accurate parameter modeling method for lithium-ion batteries. A precise state space model generated from an equivalent electric circuit is used to carry out the proposed identification process, where parameter identification is a nonlinear optimization process problem. The African vultures optimization algorithm (AVOA) is utilized to solve this problem by simulating African vultures’ foraging and navigating habits. The AVOA is used to implement this strategy and improve the quality of the solutions. Four scenarios are considered to take the effect of loading, fading, and dynamic analyses. The fitness function is selected as the integral square error between the estimated and measured voltage in these scenarios. Numerical simulations were executed on a 2600 mAhr Panasonic Li-ion battery to demonstrate the effectiveness of the suggested parameter identification technique. The proposed AVOA was fulfilled with high accuracy, the least error, and high closeness with the experimental data compared with different optimization algorithms, such as the Nelder–Mead simplex algorithm, the quasi-Newton algorithm, the Runge Kutta optimizer, the genetic algorithm, the grey wolf optimizer, and the gorilla troops optimizer. The proposed AVOA achieves the lowest fitness function level of the scenarios studied compared with relative optimization algorithms. Full article

A new phosphate-containing bio-polyester based on glycerol and citric acid was synthesized and evaluated as fire-retardant (FR) in wooden particleboards. Phosphorus pentoxide was used to first introduce phosphate esters in the glycerol followed by esterification with citric acid to produce the bio-polyester. The phosphorylated products were characterized by ATR-FTIR, ¹H-NMR and TGA-FTIR. After polyester curing, they were grinded and incorporated in laboratory produced particleboards. The fire reaction performance of the boards was evaluated by cone calorimeter. An increased char residue was produced depending on the phosphorus content and the THR (Total Heat Release), PHRR (Peak of Heat Release Rate) and MAHRE (Maximum Average of the Rate of Heat Emission) were considerably reduced in presence of the FRs. Highlights: Phosphate containing bio-polyester as fire retardant in wooden particle board; Fire performance is improved; Bio-polyester acts in the condensed and gas phases; Additive effectiveness similar to ammonium polyphosphate. Full article

Dietary interventions have captured the attention of nutritionists due to their health-promoting aspects, in addition to medications. In this connection, supplementation of nutraceuticals is considered as a rational approach to alleviating various metabolic disorders. Among novel strategies, prebiotic-supplemented foods are an encouraging trend in addressing the issue. In the present investigation, prebiotic fructooligosaccharides (FOS) were extracted from garlic (Allium sativum L.) powder using ultrasound-assisted extraction (UAE). The response surface methodology (RSM) was used to optimize the independent sonication variables, i.e., extraction temperature (ET, 80, 90, and 100 °C), amplitude level (AL, 70, 80, and 90%) and sonication time (ST, 10, 15 and 20 min). The maximum FOS yield (6.23 ± 0.52%) was obtained at sonication conditions of ET (80 °C), AL (80%) and ST (10 min), while the minimum yield of FOS was obtained at high operating temperatures and time. The optimized FOS yield (7.19%) was obtained at ET (80 °C), AL (73%) and ST (15 min) after model validation. The influence of sonication parameters, i.e., ET, AL and ST, on FOS yield was evaluated by varying their coded levels from −1 to +1, respectively, for each independent variable. High-performance liquid chromatography with refractive index detector (HPLC-RID) detection and quantification indicated that sucrose was present in high amounts (2.06 ± 0.10 g/100 g) followed by fructose and glucose. Total FOS fractions which included nystose present in maximum concentration (526 ± 14.7 mg/100 g), followed by 1-kestose (428 ± 19.5 mg/100 g) and fructosylnystoses (195 ± 6.89 mg/100 g). Conclusively, garlic is a good source of potential prebiotics FOS and they can be extracted using optimized sonication parameters using ultrasound-assisted techniques with maximum yield percentage. Full article

The current review investigates the effects of black seed (Nigella sativa) on human health, which is also used to encapsulate and oxidative stable in different food products. In recent decades, many extraction methods, such as cold pressing, supercritical fluid extraction, Soxhlet extraction, hydro distillation (HD) method, microwave-assisted extraction (MAE), ultrasound-assisted extraction, steam distillation, and accelerated solvent extraction (ASE) have been used to extract the oils from black seeds under optimal conditions. Black seed oil contains essential fatty acids, in which the major fatty acids are linoleic, oleic, and palmitic acids. The oxidative stability of black seed oil is very low, due to various environmental conditions or factors (temperature and light) affecting the stability. The oxidative stability of black seed oil has been increased by using encapsulation methods, including nanoprecipitation, ultra-sonication, spray-drying, nanoprecipitation, electrohydrodynamic, atomization, freeze-drying, a electrospray technique, and coaxial electrospraying. Black seed, oil, microcapsules, and their components have been used in various food processing, pharmaceutical, nutraceutical, and cosmetics industries as functional ingredients for multiple purposes. Black seed and oil contain thymoquinone as a major component, which has anti-oxidant, -diabetic, -inflammatory, -cancer, -viral, and -microbial properties, due to its phenolic compounds. Many clinical and experimental studies have indicated that the black seed and their by-products can be used to reduce the risk of cardiovascular diseases, chronic cancer, diabetes, oxidative stress, polycystic ovary syndrome, metabolic disorders, hypertension, asthma, and skin disorders. In this review, we are focusing on black seed oil composition and increasing the stability using different encapsulation methods. It is used in various food products to increase the human nutrition and health properties. Full article

Background: A “surgery as needed” approach may be offered to patients with esophageal cancer (EC) who achieve major histopathological response (MaHR) after neoadjuvant chemoradiotherapy (nCRT). However, the utility of clinical response assessment (CRE) for predicting histopathological response to nCRT remains limited. Circulating tumor cells (CTCs) hold promise as biomarkers of response to nCRT. Methods: We analyzed the clinical utility of post-nCRT CTCs, alone or in combination with CRE, in the prediction of MaHR. We defined MaHR as either the lack or a limited presence (≤10%) of vital residual tumor cells in the resected esophageal specimen in the absence of nodal involvement. Results: Of the 48 study patients, 27 (56%) achieved MaHR. Patients with MaHR had a significantly lower CTCs count compared with those without (3.61 ± 4.53 versus 6.83 ± 5.22 per mL of blood, respectively; P = 0.027). Using a cutoff for positivity of 5 CTCs per mL of blood, the combination of CTCs and CRE allowed achieving a negative predictive value for MaHR of 93% (95% confidence interval [CI] = 70–99%) along with a false negative rate of 5% (95% CI = 1–33%). Conclusion: CTCs count assessed in combination with CRE can potentially help identify patients with EC who achieved MaHR after nCRT. Full article

This article seeks to recover the financial rights of separated women living in the Muslim communities of Russia’s Volga-Ural region in the eighteenth and early nineteenth centuries. It argues that by the 1780s–1820s, separated Muslim women were guaranteed certain rights and powers over their marital finances and personal property. These rights emerged out of a complex plural legal landscape created by the Volga-Ural region’s complicated religious and political history in the late medieval and early modern periods. By the end of the eighteenth century, separated Muslim women could claim certain financial rights under both Islamic law and Russian civil law, but had to pursue different kinds of claims through different legal systems. The legal landscape and practices that evolved in relation to separated women’s rights during the early modern period became formalized and institutionalized in the nineteenth century and persisted until the collapse of the Russian empire. Full article