Stress test

This paper presents the investigation of the dynamic mechanical properties of coal rock under complex stress conditions at depth, based on the improved Separate Hopkinson Pressure Bar Test System. A total of 15 groups of coal samples were used to perform dynamic impact tests under different conditions. The changing rules of dynamic strength, crushing, fractal dimension and damage modes of coal under different stress conditions were analyzed. A total of nine groups of coal samples were selected for numerical simulation using ANSYS/LS-DYNA...

BACKGROUND: Two main problems examining the mechanism of cancer progression in the tissues using the computational models are lack of enough knowledge on the effective factors for such events in vivo environments and lack of specific parameters in the available computational models to simulate such complicated reactions. METHODS: In this study, it was tried to simulate the progression of cancerous lesions in the bone tissues by an independent parameter from the anatomical and physiological characteristics of the tissues, so to degrade the orthotropic mechanical properties of the bone tissues, a virtual temperature was determined to be used by a well-known framework for simulation of damages in the composite materials...

AIMS: Cellular senescence (CS) represents an intracellular defense mechanism responding to stress signals and can be leveraged as a "vulnerability" in cancer treatment. This study aims to construct a CS atlas for gastric cancer (GC) and uncover potential therapeutics for GC patients. MATERIALS AND METHODS: 38 senescence-associated regulators with prognostic significance in GC were obtained from the CellAge database to construct Gastric cancer-specific Senescence Score (GSS)...

Introduction Bone as a material varies its composition and mechanical properties throughout life. Although these variations are better understood in adulthood, there is little experimental information on the variation of these properties in early stages of development. The objective of this study is to analyze the mechanical behavior and chemical properties of cortical bone tissue from two animal species in these earliest stages. Material and methodology Twenty specimens of cortical bone were manufactured from bovine and ovine species that were in different stages of development (feeding exclusively on breast milk, in the transition period to feed or pasture, and young animals but on a solid food diet)...

Many characteristics of artificial light have been evaluated; however, light-flicker frequency (F) has not been assessed extensively in poultry. Pullets (1,344 per strain [S]; Lohmann Brown-Lite [LB] and LSL-Lite [LW]) were placed into 8 light-tight rooms, containing 6 floor pens (15 pen replicates per F × S for 30 and 250 Hz; 18 pen replicates per F x S for 90 Hz), and assigned 1 of 3 F treatments (30, 90, 250 Hz). The experiment took place over 2 trials (blocks). To evaluate long-term effects of F during rearing, birds were followed through the hen phase...

The objective of the study was to examine potential associations between positive youth development constructs (gratitude, future orientation, purpose in life) and psychological functioning (posttraumatic stress symptoms, depressive symptoms, maladaptive grief reactions) among bereaved youth and test whether these associations vary by age. A diverse sample of 197 clinic-referred bereaved youth (56.2% female; M = 12.36, SD = 3.18; 36.1% Hispanic, 23.7% White, 20.1% Black, 11.9% Multiracial, and 8.2% another race/ethnicity) completed self-report measures of psychological functioning and positive youth development constructs...

The global Covid-19 pandemic had a devastating impact on our lives. The pandemic led to sudden and momentous changes in mobility styles and travel habits. Many users started preferring to travel via private vehicles, which is contrary to sustainability policies. Strict measures were implemented against the Covid-19 pandemic in Turkey during this process, as was the case all over the world. Taking into consideration these realities, the aim of the present study was to examine the impacts of the Covid-19 pandemic on the travel modes (public transportation, walking, and bicycle), anxiety and stress perceptions, and working conditions of individuals...

For the first time, kinetic thermomagnetic extraction is a novel approach presented in this work. It required the application of four distinct variables: rotation speed (50, 75, and 100 rpm), magnetic field (0.8, 1.2, and 1.6 T), time interval (30, 60, and 90 min), and temperature (45, 55, and 65°C). Numerous phytochemical categories were detected in the 81 crude chloroform extracts of green sweet bell pepper seeds that were collected, according to phytochemical analysis. Nine extracts were discovered to be linked to the coumarin chemical class and to have the same two extraction parameters: a 90-minute extraction duration and a 55°C extraction temperature...

OBJECTIVE: Sexual minority men experience disproportionately elevated rates of skin cancers, likely driven by excess ultraviolet radiation exposure-namely through tanning behaviors. However, limited integrated theoretical models exist to explain sexual minority men's elevated skin cancer risk. The aim of the current study is to further test and refine an integrated theory of skin cancer risk behaviors among sexual minority men by incorporating minority stress into the integrated health behavior model of tanning...

OBJECTIVE: Comorbidity between posttraumatic stress disorder (PTSD) and disordered eating (DE) symptoms is common, reflecting a possible reciprocal relationship between these disorders. Network analysis may reveal candidate mechanisms underlying their comorbidity and highlight important treatment targets. METHOD: Two national samples of U.S. veterans endorsing trauma exposure self-reported PTSD and DE symptoms. The discovery sample included veterans from all service eras ( n = 434)...

The COVID-19 pandemic has been stressful for individuals worldwide, including parents. Most research investigating stress during the pandemic has focused on single stressors in relation to outcomes and has been conducted in Western countries. Among parents from Middle Eastern and North African (MENA) countries, the present study used latent class analysis to identify specific subgroups of individuals based on combinations of stressful events experienced during the first two waves of the COVID-19 global pandemic...

BACKGROUND: Recent reports have unveiled the potential utility of l-carnitine to alleviate metabolic dysfunction-associated steatohepatitis (MASH) by enhancing mitochondrial metabolic function. However, its efficacy at preventing the development of HCC has not been assessed fully. METHODS: l-carnitine (2 g/d) was administered to 11 patients with MASH for 10 weeks, and blood liver function tests were performed. Five patients received a serial liver biopsy, and liver histology and hepatic gene expression were evaluated using this tissue...

OBJECTIVE: The aim of this in vitro study was to assess the stress distribution of novel endodontic rotary files of different cross sections and metallurgy against the root canal wall at three different levels by using finite element analysis. METHODS: A total of 60 novel NiTi rotary files were included in this study after being scanned for any surface deformities using a scanning electron microscope. The scanned files were assigned into 4 groups of 15 samples each based on their metallurgy and design: Group A-TruNatomy, Group B-XP-endo Shaper, Group C-F360, and Group D-2shape files...

Layla is a 6.7-year-old girl diagnosed with attention-deficit/hyperactivity disorder (ADHD)-predominantly hyperactive/impulsive type-delayed adaptive skills, enuresis, unspecified malnutrition, and feeding difficulties. She presented to developmental-behavioral pediatrics (DBP) in January 2022 due to caregiver concerns for autism spectrum disorder (ASD).Layla lives in a polyamorous family with her biological mother and father, mother's partner whom Layla refers to as her uncle, and her 2 half-siblings. There is a maternal history of special education services, schizoaffective disorder, bipolar disorder, multiple sclerosis, Wolff-Parkinson-White syndrome, and ADHD...

As electronic devices for aviation, space, and satellite applications become more sophisticated, built-in energy storage devices also require a wider temperature spectrum. Herein, an all-climate operational, energy and power-dense, flexible, in-plane symmetric pseudocapacitor is demonstrated with utmost operational safety and long cycle life. The device is constructed with interdigital-patterned laser-scribed carbon-supported electrodeposited V5 O12 ·6H2 O as a binder-free electrode and a novel high-voltage anti-freezing water-in-salt-hybrid electrolyte...

BACKGROUND: Why do potentially traumatic events (PTEs) and substance use (SU) so commonly co-occur during adolescence? Causal hypotheses developed from the study of posttraumatic stress disorder (PTSD) and substance use disorder (SUD) among adults have not yet been subject to rigorous theoretical analysis or empirical tests among adolescents with the precursors to these disorders: PTEs and SU. Establishing causality demands accounting for various factors (e.g. genetics, parent education, race/ethnicity) that distinguish youth endorsing PTEs and SU from those who do not, a step often overlooked in previous research...

OBJECTIVES: Transient ischemic dilatation (TID) in myocardial perfusion single photon emission computed tomography (SPECT) is considered a marker of poor prognosis. However, it has been suggested that some cases are due to apparent volumetric changes secondary to differences in heart rate (HR) at the time of acquisition. We assessed the correlation between transient dilatation and HR in low risk patients with no perfusion defects. METHODS: We retrospectively analyzed patients sent for 99mTc-MIBI SPECT using a 2-day protocol...

The oxygen and hydrogen isotopic composition (δ18O, δ2H) of plant tissues are key tools for the reconstruction of hydrological and plant physiological processes and may therefore be used for disentangling reasons of tree mortality. However, how both elements respond to soil drought conditions before death have rarely been investigated. To test this, we performed a greenhouse study and determined predisposing fertilization and lethal soil drought effects on δ18O and δ2H values of organic matter (OM) in leaves and tree rings of living and dead saplings of five European tree species...

Introduction  Obstructive sleep apnea (OSA) is a severe form of sleep-disordered breathing (SDB) that is strongly correlated with comorbidities, in which epiglottic collapse (EC) and other contributing factors are involved. Objectives  To evaluate the occurrence of EC in OSA patients through drug-induced sleep endoscopy (DISE) and to determine the factors contributing to EC. Methods  A retrospective study of 37 adult patients using medical history. Patients were assessed for laryngopharyngeal reflux (LPR) and lingual tonsil hypertrophy (LTH) using reflux symptom index and reflux finding score (RFS); for OSA using polysomnography, and for airway collapse through DISE...

Background Saliva has a powerful antioxidant activity proposing that it might have a protective role in the oral cavity. It is yet unclear, how circadian rhythm might affect this activity. Objective The main goal of this study was to compare the antioxidant status of saliva in patients with periodontal diseases (PD) to that of healthy people on a diurnal basis. Material and methods A total of 18 periodontal healthy individuals and 18 patients with chronic periodontitis were chosen. Samples of saliva were collected in the morning between 6:00 and 8:00 and in the evening between 6:00 and 8:00 (both stimulated and non-stimulated)...