Uniaxial compressive damage evolution and constitutive modeling of fissure-like rocks under different loading rates based on acoustic emission.

In natural environments, most rocks possess internal fissures and are often exposed to diverse external loads arising from engineering activities and ground stress, among other factors. This study aims to explore the influence of different loading rates on the mechanical properties and acoustic emission (AE) characteristics of fissured rocks and to develop an intrinsic damage model. To achieve this, prefabricated fissured rock specimens that mimic natural rocks were prepared.

Prevalence of falls and associations with family functioning among community-dwelling older adults in Guangzhou, China.

Introduction: Falls are the primary cause of unintentional fatalities among individuals aged 65 and older. Enhancing research on fall prevention among older adults is an urgent priority. Consequently, this study aims to investigate the prevalence and influencing factors of falls among community-dwelling older adults in Guangzhou, China, with a particular emphasis on the impact of family functioning.

Hydrogen Bond-Mediated Self-Assembly of Carbon Dots Enabling Precise Tuning of Particle and Cluster Luminescence for Advanced Optoelectronic Applications.

The effective control over the self-assembly process of carbon dots (CDs) and their cluster luminescence in the aggregated state is of paramount significance and challenge. This study, for the first time, systematically explores the photoluminescent behavior of CDs in their aggregated state, which is less understood compared to their discrete state. By investigating the effects of concentration and solvent environment, it's demonstrated that CDs could exhibit dual emission properties, shifting from blue particle emissions to red cluster emissions as they aggregate.

Poria cocos-derived carbon dots for parallel detection of Cr/Fe in complex environments with superior sensitivity.

Multifunctional sensor capable of parallel sensing is of great importance thanks to their wide applications and great practicality. In this report, Poria cocos-derived carbon dots (CDs) were adopted for the development of multifunctional sensor for the parallel detection of Cr and Fe with superior sensitivity and applicability. Specifically, extremely low limit of detection (LOD) of 1.

Effect of airflow rate on droplet deposition of an impinging-jet inhaler in the human respiratory tract.

This paper presents a numerical investigation to understand the transport and deposition of sprays emitted by an impinging-jet inhaler in the human respiratory tract under different inhalation flow rates. An injection model is used for the numerical simulations considering the spreading angles of the spray in the two directions, which are measured from experiments. The model parameter is adjusted to match the mean droplet size measured in the previous experiment.

Experimental Investigation on the Influence of Water on Rockburst in Rock-like Material with Voids and Multiple Fractures.

To investigate the influence of water content on the rockburst phenomena in tunnels with horizontal joints, experiments were conducted on simulated rock specimens exhibiting five distinct levels of water absorption. Real-time monitoring of the entire blasting process was facilitated through a high-speed camera system, while the microscopic structure of the rockburst debris was analyzed using scanning electron microscopy (SEM) and a particle size analyzer. The experimental findings revealed that under varying degrees of water absorption, the specimens experienced three stages: debris ejection; rockburst; and debris spalling.

Carbon dots as multifunctional fluorescent probe for Fe sensing in ubiquitous water environments and living cells as well as lysine detection via "on-off-on" mechanism.

Iron and amino acids are essential nutrients for living organisms, and their deficiency or excess can cause a range of diseases. Therefore, there is considerable interest in developing sensing assays capable of detecting these nutrients with sensitivity, selectivity, and multifunctionality even in complex environments. In this report, hydrothermally synthesized blue fluorescent carbon dots (C-dots) from zinc gluconate were utilized for the detection of Fe and lysine via "on-off" and "on-off-on" mechanisms, respectively.

Solid-State, Hectogram-Scale Preparation of Red Carbon Dots as Phosphor for Energy-Transfer-Induced High-Quality White LEDs with CRI of 97.

In this study, pre-crystallization-controlled, solid-state preparation of red carbon dots (C-dots) from o-phenylenediamine on a hectogram scale with a 94% yield is reported. Highly efficient red phosphor (C-dots@MCC) is obtained by dispersing the C-dots in microcrystalline cellulose, which matched extremely well with the commercial Y Al O :Ce (YAG) phosphor. White light-emitting diodes (WLEDs) fabricated from the two phosphors emitted warm white light with a correlated color temperature of 3845 K, CIE color coordinates of (0.

Behavioral and psychosocial factors and their effects on insomnia among people undergoing entry quarantine in hotels during COVID-19 pandemic: a cross-sectional study in Guangzhou, China.

Background: The COVID-19 pandemic continues to impact global health and China requires a 14-day quarantine for individuals on flights with positive COVID-19 cases. This quarantine can impact mental well-being, including sleep. This study aims to examine the impact of psychosocial and behavioral factors on insomnia among individuals undergoing quarantine in hotels.

Carbon Dots-Based Fluorescence Assay for the Facile and Reliable Detection of Ag in Natural Water and Serum Samples.

In this report, red-emissive carbon dots (C-dots) were facilely prepared from -phenylenediamine via microwave-assisted hydrothermal treatment. The C-dots demonstrated excitation wavelength-independent emission with maximums at 621 nm that could be effectively quenched by Ag via static quenching. This phenomenon was exploited to establish a sensitive fluorescence assay with a low detection limit (0.

An insight into embryogenesis interruption by carbon nitride dots: can they be nucleobase analogs?

The carbon nitride dot (CND) is an emerging carbon-based nanomaterial. It possesses rich surface functional moieties and a carbon nitride core. Spectroscopic data have demonstrated the analogy between CNDs and cytosine/uracil.

Hydrothermal vs microwave nanoarchitechtonics of carbon dots significantly affects the structure, physicochemical properties, and anti-cancer activity against a specific neuroblastoma cell line.

Carbon dots (CDs) from glucose were synthesized using two of the most common bottom-up methods, namely, microwave assisted (MW) and hydrothermal carbonization (HT). Synthetic parameters such as reaction time, temperature, and precursor concentration were changed to study the effects of each parameter on CD size, structure, surface functionalities, charge, photoluminescence behavior, quantum yield, cytotoxicity, blood-brain barrier (BBB) crossing ability and bioimaging. A detailed analysis is performed to compare the structure and properties of the CDs synthesized in ten different conditions.

Sensitive, Selective and Reliable Detection of Fe in Lake Water via Carbon Dots-Based Fluorescence Assay.

In this study, C-dots were facilely synthesized via microwave irradiation using citric acid and ethylenediamine as carbon precursors. The fluorescence emissions of the C-dots could be selectively quenched by Fe, and the degree of quenching was linearly related to the concentrations of Fe presented. This phenomenon was utilized to develop a sensitive fluorescence assay for Fe detection with broad linear range (0-250, 250-1200 μmol/L) and low detection limit (1.

Synthesis Mechanisms, Structural Models, and Photothermal Therapy Applications of Top-Down Carbon Dots from Carbon Powder, Graphite, Graphene, and Carbon Nanotubes.

In this study, top-down syntheses of carbon dots (CDs) from four different carbon precursors, namely, carbon nano powders, graphite, graphene, and carbon nanotubes, were carried out. Systematic study demonstrated that the optical properties and surface functionalities of the CDs were quite similar and mainly influenced by the synthesis method, while the sizes, morphologies, chemical compositions, and core structures of the CDs were heavily influenced by the carbon precursors. On the basis of these studies, the formation processes and structural models of these four top-down CDs were proposed.

Ferulic acid regulates miR-17/PTEN axis to inhibit LPS-induced pulmonary microvascular endothelial cells apoptosis through activation of PI3K/Akt pathway.

Acute lung injury (ALI) is mainly mediated by the damage of pulmonary microvascular endothelial cells (PMVECs). LPS is one of the pathogenic factors leading to microcirculatory abnormalities of ALI. Ferulic acid (FA) exhibits therapeutic effects against various diseases.

Carbon dot composites for bioapplications: a review.

Carbon dots (CDs) have received extensive attention in the last decade for their excellent optical, chemical and biological properties. In recent years, CD composites have also received significant attention due to their ability to improve the intrinsic properties and expand the application scope of CDs. In this article, the synthesis processes of four types of CD composites (metal-CD, nonmetallic inorganics-CD, and organics-CD as well as multi-components-CD composites) are systematically summarized first.

Facile and Sensitive Detection of Nitrogen-Containing Organic Bases with Near Infrared C-Dots Derived Assays.

In this article, we have designed both colorimetric (including solution and test paper type) and spectral sensors (including UV-vis and PL type) for the quick and sensitive detection of general nitrogen-containing organic bases (NCOBs); the limit of detection could reach as low as 0.50 nM. NCOBs included 11 examples, covering aliphatic and aromatic amines, five- and six-membered heterocyclics, fused-ring heterocyclics, amino acids, and antibiotics.

Size-Dependent Photocatalytic Activity of Carbon Dots with Surface-State Determined Photoluminescence.

Carbon dots (CDs) were synthesized by a microwave-mediated method and separated by size exclusion chromatography into three different size fractions. There was no correlation of the size with photoluminescence (PL) emission wavelength, which shows that the PL mechanism is not quantum-size dependent. UV/vis absorption and diffuse reflectance spectroscopies showed that the light absorption properties as well as the band gap of the CDs changed with the size of the particle.

Recent Developments of Carbon Dots in Biosensing: A Review.

Early diagnosis of diseases is of great importance because it increases the chance of a cure and significantly reduces treatment costs. Thus, development of rapid, sensitive, and reliable biosensing techniques is essential for the benefits of human life and health. As such, various nanomaterials have been explored to improve performance of biosensors, among which, carbon dots (CDs) have received enormous attention due to their excellent performance.

Facile Synthesis of "Boron-Doped" Carbon Dots and Their Application in Visible-Light-Driven Photocatalytic Degradation of Organic Dyes.

Carbon dots (C-dots) were facilely fabricated via a hydrothermal method and fully characterized. Our study shows that the as-synthesized C-dots are nontoxic, negatively charged spherical particles (average diameter 4.7 nm) with excellent water dispersion ability.

Direct conjugation of distinct carbon dots as Lego-like building blocks for the assembly of versatile drug nanocarriers.

As a promising drug nanocarrier, carbon dots (CDs) have exhibited many excellent properties. However, some properties such as bone targeting and crossing the blood-brain barrier (BBB) only apply to a certain CD preparation with limited drug loading capacity. Therefore, it is significant to conjugate distinct CDs to centralize many unique properties on the novel drug nanocarrier.

Bone Tissue Engineering via Carbon-Based Nanomaterials.

Bone tissue engineering (BTE) has received significant attention due to its enormous potential in treating critical-sized bone defects and related diseases. Traditional materials such as metals, ceramics, and polymers have been widely applied as BTE scaffolds; however, their clinical applications have been rather limited due to various considerations. Recently, carbon-based nanomaterials attract significant interests for their applications as BTE scaffolds due to their superior properties, including excellent mechanical strength, large surface area, tunable surface functionalities, high biocompatibility as well as abundant and inexpensive nature.