Crack

The importance of aesthetics in children has increased over time. Therefore, this multicenter randomized clinical trial aimed to analyze and compare three-dimensional (3D)-printed resin crowns (RCs) as a potential alternative to stainless-steel crowns (SSCs) for restoring primary molars with extensive carious lesions. According to the null hypothesis, no statistically significant difference was observed in restoration failure between RC and SSC groups. A total of 56 primary molars after pulp treatment at two dental hospitals were included...

This work is devoted to the emergence of a connected network of slots (cracks) on a square grid. Accordingly, extensive Monte Carlo simulations and finite-size scaling analysis have been conducted to study the site percolation of straight slots with length l measured in the number of elementary cells of the grid with the edge size L. A special focus was made on the dependence of the percolation threshold p_{C}(l,L) on the slot length l varying in the range 1≤l≤L-2 for the square grids with edge size in the range 50≤L≤1000...

We introduce an approach to particle breakage, wherein the particle is modeled as an aggregate of polyhedral cells with their common surfaces governed by the Griffith criterion of fracture. This model is implemented within a discrete element code to simulate and analyze the breakage behavior of a single particle impacting a rigid plane. We find that fracture dynamics involves three distinct regimes as a function of the normalized impact energy ω. At low values of ω, the particle undergoes elastic rebound and no cracks occur inside the particle...

With increasing global awareness of soil health, attention must be paid to fluorine exposure in soils, which poses a threat to human health. Therefore, this study aimed to study the fluorine adsorption characteristics of swine manure and straw biochars and their impact on fluorine adsorption-desorption in soil with batch experiments. The biochar samples originated from high-temperature anaerobic cracking of swine manure (350°C, 500°C, and 650°C) and straw (500°C). Results indicated that the adsorption of soil fluorine reached adsorption equilibrium at around 4 h after the mixing of swine manure and straw biochar...

This article reconstructs the complex diplomatic negotiations that led to the peculiar organization of molecular biology at the European level, by focusing in particular on the establishment of the European Molecular Biology Conference (EMBC), the intergovernmental structure founded in 1969-70 to support the scientific program of the European Molecular Biology Organization (EMBO). By combining the analysis of the informal decision-making kept in the Nobel Prize laureate John C. Kendrew's personal papers (Oxford) with the in-depth exploration of the institutional documentation available in the EMBO and CERN archives (Heidelberg and Geneva) and the Swiss Federal Archives (Bern), the article sheds light on the importance of the EMBC not only for the construction of molecular biology as a scientific, social, and political field in the European context, but also for the broader process of definition of the European research policy...

Lithium metal batteries (LMBs) offer substantial promise for next-generation energy storage owing to lithium metal's low reduction potential (-3.045 V vs. the standard hydrogen electrode) and its high specific capacity of 3860 mA h g-1 . Among various cathode materials in LMBs, LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) is extensively employed because of its notably high specific capacity (over 200 mA h g-1 ) and comparatively lower cost. However, structural stress, nickel ions migration, and uneven Li+ deposition in NCM811 particles lead to cracking, irreversible decomposition of active substances, and the growth of mossy Li dendrites, causing severe capacity decline and low Coulomb efficiency in LMBs...

BACKGROUND: Radiation therapy (RT) is often indicated in the treatment of breast cancer following breast conserving surgery or mastectomy, yet carries a 95% risk of radiation dermatitis (RD) of varying severity within 1 to 4 weeks of treatment. The burdens of RT include skin breakdown, pain, psychological distress, and functional challenges. Given limited patient education regarding the prevention and management of RD, a Clinician Guide and Evidence-based Skin Care Plan were developed to offer a holistic, patient-centered approach to care, with optimal RD prevention and management strategies to enhance patients' quality of life and survival...

BACKGROUND: Almost all paramedics encounter workplace violence (WPV) during their careers. The most common form of WPV is verbal, and the perpetrator is usually the patient. It is known that paramedics suffer from post-traumatic stress disorder and other mental health problems, and WPV is one of the reasons behind that. Nevertheless, little is known about the recovery processes paramedics have had after encountering WPV. The research question was: What kind of recovery processes have paramedics had after encountering WPV? METHODS: A qualitative, narrative interview study was done...

Fatigue crack propagation resistance and high-cycle S-N fatigue life of cortical bone allograft tissue are both negatively impacted in a radiation dose-dependent manner from 0 to 25 kGy. The standard radiation sterilization dose of 25-35 kGy has been shown to induce cleavage of collagen molecules into smaller peptides and accumulation of stable crosslinks within the collagen matrix, suggesting that these mechanisms may influence radiation-induced losses in cyclic fracture resistance. The objective of this study was to determine the radiation dose-dependency of collagen chain fragmentation and crosslink accumulation within the dose range of 0-25 kGy...

Supercontinuum generation (SCG) is an important nonlinear optical process enabling broadband light sources for many applications, for which silicon nitride (Si3 N4 ) has emerged as a leading on-chip platform. To achieve suitable group velocity dispersion and high confinement for broadband SCG the Si3 N4 waveguide layer used is typically thick (>∼700 nm), which can lead to high stress and cracks unless specialized processing steps are used. Here, we report on efficient octave-spanning SCG in a thinner moderate-confinement 400-nm Si3 N4 platform using a highly nonlinear tellurium oxide (TeO2 ) coating...

To investigate the influence of carbonization process parameters on the characteristics of municipal sludge carbonization products, this study selected carbonization temperatures of 300-700 °C and carbonization times of 0.5-1.5 h to carbonize municipal sludge. The results showed that with an increase in temperature and carbonization time, the sludge was carbonized more completely, and the structure and performance characteristics of the sludge changed significantly. Organic matter was continuously cracked, the amorphous nature of the material was reduced, its morphology was transformed into an increasing number of regular crystalline structures, and the content of carbon continued to decrease, from the initial 52...

Despite the prevalence of substance use during pregnancy, studies focusing exclusively on Neonatal Intensive Care Units (NICU) admissions remain limited. This study investigates the impact of maternal use of tobacco, alcohol, and/or crack, on neonatal outcomes among infants admitted to three Brazilian NICUs. Additionally, the investigation explores the impact of substance use on DNA damage in newborns. Over a one-year period, data from 254 newborns were collected through medical records, accompanied by blood samples...

Aluminum oxide (Al2O3) nanopowder is spin-coated onto both sides of commercial polypropene separator to create artificial solid-electrolyte interphase (SEI) and artificial cathode electrolyte interface (CEI) in potassium metal batteries (KMBs). This significantly enhances the stability, including of KMBs with Prussian Blue (PB) cathodes. For example, symmetric cells are stable after 1,000 cycles at 0.5 mA/cm2 - 0.5 mAh/cm2 and 3.0 mA/cm2 - 0.5 mAh/cm2. Alumina modified separators promote electrolyte wetting and increase ionic conductivity (0...

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Bone tissue is subjected to increased mechanical stress during high-intensity work. Inadequate bone remodeling reparability can result in the continuous accumulation of microdamage, leading to stress fractures. The aim of this work was to investigate the characteristics and repair mechanisms of tibial microdamage under several degrees of overload. Also, we aimed at better understanding the effects of overload on the multi-scale structure and mechanical properties of bone. Sixty 5-month female rats were divided into three groups with different time points...

Nacre is a classic model, providing an inspiration for fabricating high-performance bulk nanocomposites with the two-dimensional platelets. However, the "brick" of nacre, aragonite platelet, is an ideal building block for making high-performance bulk nanocomposites. Herein, we demonstrated a strong and tough conductive nacre through reassembling aragonite platelets with bridged by MXene nanosheets and hydrogen bonding, not only providing high mechanical properties but also excellent electrical conductivity...

INTRODUCTION: Orthodontic treatment with fixed vestibular appliances is still widely used worldwide. When choosing the aesthetic alternative of ceramic brackets, the possibility of failure and cracking of braces should be considered. Therefore, the aim of the present study was to compare the failure rates of ceramic and metal brackets in a 12-month clinical study. METHODS: Eighty patients undergoing fixed orthodontic treatment with vestibular appliances were enrolled and divided into 2 equal groups: MET for metal brackets and CER for ceramic brackets...

Plant-based biochar was demonstrated promising capability in adsorbing microplastic particles (MPs) within soil porous mediums. However, biochar's function in mitigating MPs' vertical penetration during wetting-drying cycles, typical of seasonal precipitation and evaporation, remains uncertain. Furthermore, few studies have investigated the structures of how biochar combines with soil. This study conducted column tests to assess the MPs retention capabilities of soil-biochar porous media under saturated and wetting-drying conditions...

Aqueous Zinc-sulfur (Zn-S) batteries are promising for the field of energy storage due to their low cost, high theoretical capacity, and safety. However, the large volume expansion and the inherently poor conductivity of sulfur would result in electrode cracking and sluggish reaction kinetics, limiting the practical application of Zn-S batteries. Herein, commercial zinc sulfide (ZnS) is employed instead of S as cathode and proposed a doping modification strategy to solve the above problems. The designed ZnS0...

Hydrogels, polymeric networks swollen with water, exhibit time/rate-dependent adhesion due to their poroviscoleastic constitution. In this study, we conducted probe-tack experiments on gelatin and investigated the influence of dwelling times and unloading rates on pull-off forces and work of adhesion. We utilized in situ contact imaging to monitor separation kinematics and interfacial crack velocities. We found that the crack velocities scaled nonlinearly with the unloading rate, in a power law with an exponent of 0...