The modern Gastroenterology have witnessed an essential stride since
was first found in the stomach and then its pathogenic effect was discovered. According to the researches conducted during the ...nearly 40 years, it has been found that this bacterium is associated with a natural history of many upper gastrointestinal diseases. Epidemiological data show an increased incidence of autoimmune disorders with or after infection with specific microorganisms. The researches have revealed that
is a potential trigger of gastric autoimmunity, and it may be associated with other autoimmune diseases, both innate and acquired. This paper reviews the current support or opposition about
as the role of potential triggers of autoimmune diseases, including inflammatory bowel disease, autoimmune thyroiditis, type 1 diabetes mellitus, autoimmune liver diseases, rheumatoid arthritis, idiopathic thrombocytopenic purpura, systemic lupus erythematosus, as well as Sjogren's syndrome, chronic urticaria and psoriasis, and tried to explain the possible mechanisms.
The relaxation spectra of the components in polymer blends determine the dynamic mechanical properties of the corresponding composite materials, which, in thermo‐rheological studies, show a delicate ...dependence on their chemical and physical properties as well as its bulk composition. A molecular dynamics simulation based Rouse mode analysis is performed to detect the relaxation spectra of the component chains on all length scales ranging from one monomer to the whole chain size, indicating that the bulk composition dominates the relaxation dynamics of the components in miscible polymer blends. The relaxation of component chains accelerates on all length scales as increasing the free volume available to monomers to move, with the dependence of mobility shift on composition being quantified by a Williams–Landel–Ferry like function governing the time‐composition superposition. Role of the chain connectivity induced self‐concentration effect on chain relaxation in polymer blends is discussed and proved to be limited, which leads to a visible but subtle length‐scale dependent rheological complexity as the composition is varied.
Rouse mode analysis performed to detect the relaxation spectra of chains on full length scales up to the whole chain size, demonstrates that the bulk composition governed dynamical environment dominates the relaxation dynamics of components in miscible polymer blends. A Williams–Landel–Ferry like function is presented and verified to quantify the dependence of mobility shift of involved components on composition.
This study aimed at developing a detailed three-dimensional (3D) finite element (FE) model of the body-seat system to investigate the effect of sitting posture and seat on the biodynamic responses of ...internal human body under vertical white noise excitation. Three postures of human models (vertical seated body (VSB), reclined seated body (RSB), and seated body in driving posture (DSB)) and three different stiffness seats were modeled. The initial boundary condition between human body and seat for biodynamic response analysis was obtained by static analysis of the body-seat system under the action of gravity. Random response analysis was performed under white noise excitation at 0–20 Hz in the vertical direction by a modal superposition method. Principal responses of lumbar intervertebral discs (LIDs) in VSB were in the range of human body natural frequencies. The damping ratio greatly decreased the peak response values of LID. When compared with the supports of the elastic seat in VSB, those of the elastic seat in RSB increased the peak response frequencies of LID in the anterior-posterior direction and decreased them in the vertical direction, thus making them equal in both directions. Compared to RSB, DSB not only increased the peak response frequencies but also changed the peak response values. The principal response frequencies of LID in both directions increased with the increase in seat stiffness. The proposed FE model of biodynamic random response analysis is a new fundamental method for gaining insights on the responses of internal human body to vibrations and can be used to investigate the responses of the human body-seat system instead of conducting experiments to evaluate the dynamic characteristics of newly designed seats and guide the design of seats for reducing the injury risk of the lumbar spine.
This study created the detailed three-dimension finite element model of body-seat system to investigate effect of sitting posture and seat on the biodynamic responses of lumbar spine under vertical white noise excitation. The conclusions were that sitting posture and seat could change the peak response frequencies of lumbar spine, and designing proper seat or changing posure could avoid or reduce the effect of certain frequency excitation on lumbar spine for protect human body health under whole body vibration. The proposed FE model of biodynamic random response analysis is a new fundamental method for gaining insights on the responses of internal human body to vibrations and can be used to research on the responses of human body-seat system instead of conducting experiment to evaluate dynamic characteristics of newly designed seats and guide the design of seats for reducing injury risk of lumbar spine under whole body vibration. Display omitted
Radiographic periodontal bone loss is one of the most important basis for periodontitis staging, with problems such as limited accuracy, inconsistency, and low efficiency in imaging diagnosis. Deep ...learning network may be a solution to improve the accuracy and efficiency of periodontitis imaging staging diagnosis. This study aims to establish a comprehensive and accurate radiological staging model of periodontal alveolar bone loss based on panoramic images.
A total of 640 panoramic images were included, and 3 experienced periodontal physicians marked the key points needed to calculate the degree of periodontal alveolar bone loss and the specific location and shape of the alveolar bone loss. A two-stage deep learning architecture based on UNet and YOLO-v4 was proposed to localize the tooth and key points, so that the percentage of periodontal alveolar bone loss was accurately calculated and periodontitis was staged. The ability of the model to recognize these features was evaluated and compared with that of general dental practitioners.
The overall classification accuracy of the model was 0.77, and the performance of the model varied for different tooth positions and categories; model classification was generally more accurate than that of general practitioners.
It is feasible to establish deep learning model for assessment and staging radiographic periodontal alveolar bone loss using two-stage architecture based on UNet and YOLO-v4.
Acoustic aberration, caused by the uneven distribution of tissue speed-of-sound (SoS), significantly reduces the quality of ultrasound imaging. An important approach to mitigate this issue is imaging ...correction based on local SoS estimation. Computed ultrasound tomography in echo mode (CUTE) is an SoS estimation method that utilizes phase-shift information from ultrasound pulse-echo signals, offering both practical utility and computational efficiency. However, the traditional single-pass CUTE often suffers from poor accuracy and robustness. In this paper, an advanced approach known as iterative CUTE is introduced, which refines SoS estimates through iterative correction of errors and noise, addressing the limitations of traditional single-pass methods. It is argued that traditional precision indicators like root mean square error (RMSE) fall short in adequately reflecting the quality of SoS estimates for imaging correction, and coherence factor (CF) is proposed as a more indicative metric. Performance validation of the iterative CUTE algorithm was conducted using a simulation and agar phantom experiment. The results indicated that the iterative CUTE approach surpasses the single-pass approach, enhancing the average CF for SoS estimates by up to 18.2%. In phantom experiments, imaging corrected with SoS estimates from iterative CUTE reduced the Array Performance Index (API) by up to 40% compared to traditional methods.
Purpose
This paper aims to provide and meta-analytically investigate a theoretical framework of work–nonwork conflict and its antecedents and outcomes in hospitality management.
...Design/methodology/approach
This paper adopts the psychometric meta-analytical methods and meta-structural equation modeling methods to synthesize the relationships between work-to-nonwork conflict (WNC) and nonwork-to-work conflict (NWC) and its antecedents and outcomes.
Findings
WNC and NWC are found to be correlated with antecedents including social support; positive affectivity and negative affectivity; work characteristics; and outcomes including job-related well-being, life-related well-being, burnout, performance and turnover intentions.
Originality/value
This paper is the very first meta-analysis in International Journal of Contemporary Hospitality Management. It is also the first meta-analysis on the relationship between overall work–nonwork conflict and its antecedents and outcomes in hospitality and tourism.
•We proposed a model for nanogear drive system with intersecting axes between motor and rotor for rotation transmission.•Between 40 K and 100 K, the rotor has stable asynchronous rotation with 60° of ...intersecting angle.•When the input rotational frequency is very high, the rotation transmission ratio is independent on temperature < 100 K.•Results guide the potential application of the present nanodevice in a nanomachine.
Using molecular dynamics simulation, the dynamic response of a nanogear drive system with intersecting axes was investigated. The nanogear drive system made from carbon nanotubes (CNT) contains two parts, i.e., a motor and a nanobearing. Their tube axes have an intersecting angle of θ. Due to van der Waals (vdW) interaction at their adjacent edges, the rotor in the bearing can be driven to rotate by the constant-speed motor. By increasing the value of θ, the vdW interaction decreases and the difference between the rotational frequencies of the motor and the rotor becomes larger. Especially, at temperature below 100 K, the system with θ = 60° has very stable and asynchronous transmission effect, which will benefit potential application of an asynchronous rotation transmission nanosystem in a nanomachine.
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In order to reveal the mechanical response of surrounding rock of karst tunnel under stress-damage-seepage coupling effect, a new damage constitutive mechanical model of surrounding rock of karst ...tunnel under stress-damage-seepage coupling effect is established, which is calculated by the COMSOL Multiphysics in this paper. When the mechanical parameters are assigned to microelements of rock mass by the Weibull distribution function, the larger the m value is, the more homogeneous the rock mass is. The variation trend of strain energy density with m is similar to equivalent stress, which increases firstly and then decreases. The number of damage points increases with the increase in loading step and decreases rapidly after reaching the peak value and then remains a small number in the later loading stage. With the increase in γ, the stress range expands to the rock mass above the vault and below the floor; the stress value increases significantly, and the surrounding rock of karst tunnel is closer to strength limit, leading to the damage of rock mass. With the increase in γ, the area of the damage area in the upper part of the vault becomes larger, and most of the rock mass below the bottom plate is damaged; the damage area is semicircular, which indicates that both places are damaged by shearing action, resulting in the developed fissures. Besides, there are the distribution characteristics of “high value on both sides with a peak value and low value in the middle position” in the permeability distribution, and high permeability is located at the arch foot, and the low permeability is located at the floor. The larger the value of γ, the larger the permeability. The research achievements provide an important theoretical basis for prediction and treatment for dynamical disaster of karst tunnel.
Squalene epoxidase (SQLE) is a key enzyme in the mevalonate-cholesterol pathway that plays a critical role in cellular physiological processes. It converts squalene to 2,3-epoxysqualene and catalyzes ...the first oxygenation step in the pathway. Recently, intensive efforts have been made to extend the current knowledge of SQLE in cancers through functional and mechanistic studies. However, the underlying mechanisms and the role of SQLE in cancers have not been fully elucidated yet. In this review, we retrospected current knowledge of SQLE as a rate-limiting enzyme in the mevalonate-cholesterol pathway, while shedding light on its potential as a diagnostic and prognostic marker, and revealed its therapeutic values in cancers. We showed that SQLE is regulated at different levels and is involved in the crosstalk with iron-dependent cell death. Particularly, we systemically reviewed the research findings on the role of SQLE in different cancers. Finally, we discussed the therapeutic implications of SQLE inhibitors and summarized their potential clinical values. Overall, this review discussed the multifaceted mechanisms that involve SQLE to present a vivid panorama of SQLE in cancers.
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