AbstractExperimental research on seismic behavior of structural columns is one of the most important and active research areas in structural engineering. Various methods with innovative loading ...configurations have been developed by researchers over the past several decades, and the research has enhanced our knowledge about the performance of structural columns, resulting in the improvement of design practice. This paper provides a state-of-the-art review of the testing setups for simulating earthquake loading on structural columns, to reveal the trend of sophistication of testing methods. Special attention is given to the large tonnage axial loading methods and the shortcomings of existing methods. Based on past experiences and a review of existing methods, a new multiuse structural testing (MUST) system is developed and described in this paper. Because the MUST equipment has the unique ability to maintain the axial load vertical during lateral loading, and the force inputs to the structural model can be directly measured, it is more suitable for simulating structural responses under horizontal and vertical ground motions.
There are still controversies as to the location of ligating the inferior mesenteric artery and the central lymph node dissection during rectal cancer surgery. The reason is that the level of ...evidence in this area is low. Existing studies are mostly retrospective, analyses or small-sample randomized controlled trials. These results showed no significant differences between high-ligation and low-ligation, in terms of anastomotic leakage and other short-term postoperative complications. Low-ligation seems better for the recovery of postoperative genitourinary function. Due to the low rate of central lymph node metastasis and many other confounding factors that affect the survival rate, it is difficult to conclude the survival benefits of ligation site or central node dissection. It is necessary to carry out some targeted, well-designed, large-scale randomized controlled trials to explain the related issues of inferior mesenteric artery ligation site and extent of central lymphadenectomy.
Summary
Background
Tinea capitis is still common in developing countries, such as China. Its pathogen spectrum varies across regions and changes over time.
Objectives
This study aimed to clarify the ...current epidemiological characteristics and pathogen spectrum of tinea capitis in China.
Methods
A multicentre, prospective descriptive study involving 29 tertiary hospitals in China was conducted. From August 2019 to July 2020, 611 patients with tinea capitis were enrolled. Data concerning demography, risk factors and fungal tests were collected. When necessary, the pathogens were further identified by morphology or molecular sequencing in the central laboratory.
Results
Among all enrolled patients, 74·1% of the cases were in patients aged 2–8 years. The children with tinea capitis were mainly boys (56·2%) and were more likely than adults to have a history of animal contact (57·4% vs. 35·3%, P = 0·012) and zoophilic dermatophyte infection (73·5% vs. 47%). The adults were mainly female (83%) and were more likely than children to have anthropophilic agent infection (53% vs. 23·9%). The most common pathogen was zoophilic Microsporum canis (354, 65·2%), followed by anthropophilic Trichophyton violaceum (74, 13·6%). In contrast to the eastern, western and northeastern regions, where zoophilic M. canis predominated, anthropophilic T. violaceum predominated in central China (69%, P < 0·001), where the patients had the most tinea at other sites (20%) and dermatophytosis contact (26%) but the least animal contact (39%). Microsporum ferrugineum was the most common anthropophilic agent in the western area, especially in Xinjiang province.
Conclusions
Boys aged approximately 5 years were the most commonly affected group. Dermatologists are advised to pay more attention to the different transmission routes and pathogen spectra in different age groups from different regions.
What is already known about this topic?
Tinea capitis is an infection of the scalp and hair caused by dermatophytes and is still common in developing countries. Prepubertal children are mainly affected.
The pathogen spectrum of tinea capitis varies across different geographical areas and changes over time.
Nationwide prospective epidemiological surveys of tinea capitis in China are rare and out of date.
What does this study add?
This study provides data concerning the epidemiological characteristics and pathogen spectrum of tinea capitis in contemporary China.
Boys aged approximately 5 years were most commonly affected and were more likely than adults to have zoophilic dermatophyte infection.
The main pathogens of tinea capitis in China are zoophilic dermatophytes, mainly Microsporum canis. In contrast to the other regions, the predominant pathogens in central China are anthropophilic dermatophytes.
Plain language summary available online
Influenza A virus (IAV) infection leads to variable and imperfectly understood pathogenicity. We report that segment 3 of the virus contains a second open reading frame ("X-ORF"), accessed via ...ribosomal frameshifting. The frameshift product, termed PA-X, comprises the endonuclease domain of the viral PA protein with a C-terminal domain encoded by the X-ORF and functions to repress cellular gene expression. PA-X also modulates IAV virulence in a mouse infection model, acting to decrease pathogenicity. Loss of PA-X expression leads to changes in the kinetics of the global host response, which notably includes increases in inflammatory, apoptotic, and T lymphocyte-signaling pathways. Thus, we have identified a previously unknown IAV protein that modulates the host response to infection, a finding with important implications for understanding IAV pathogenesis.
Intestinal IgA, which is regulated by gut microbiota, has a crucial role in maintenance of intestinal homeostasis and in protecting the intestines from inflammation. However, the means by which ...microbiota promotes intestinal IgA responses remain unclear. Emerging evidence suggests that the host can sense gut bacterial metabolites in addition to pathogen-associated molecular patterns and that recognition of these small molecules influences host immune response in the intestines and beyond. We reported here that microbiota metabolite short-chain fatty acid acetate promoted intestinal IgA responses, which was mediated by "metabolite-sensing" GPR43. GPR43
mice demonstrated lower levels of intestinal IgA and IgA
gut bacteria compared with those in wild type (WT) mice. Feeding WT but not GPR43
mice acetate but not butyrate promoted intestinal IgA response independent of T cells. Acetate promoted B-cell IgA class switching and IgA production in vitro in the presence of WT but not GPR43
dendritic cells (DCs). Mechanistically, acetate-induced DC expression of Aldh1a2, which converts Vitamin A into its metabolite retinoic acid (RA). Moreover, blockade of RA signaling inhibited the acetate induction of B-cell IgA production. Our studies thus identified a new pathway by which microbiota promotes intestinal IgA response through its metabolites.
Water plays an important role in the whole process of geopolymer synthesis. X-ray diffraction (XRD) and thermogravimetry (TG) showed that residual water depressed the activity development of calcined ...kaolin before stable crystalline phases formed as confirmed by the compressive strength. Reaction heat evolution measurement revealed that high liquid/solid ratio could accelerate the dissolution of raw materials and the hydrolysis of Si
4+ and Al
3+ compounds but hinder the polycondensation when OH
− concentration is high enough as 12 mol/L. The effect of nonevaporable water on the strength variation of geopolymers was firstly analyzed. The results indicated that nonevaporable water was necessary to keep the strength stable and the optimum content was about 7.4%.
•Developed a new type of hybrid space truss system composed of steel lower chord and glubam upper chords and web elements.•Experimentally investigated the gravity loading behavior of the steel-glubam ...truss, validating its good capacity.•Different possible failure modes were investigated and the lower chord yielding can offer larger deformability.
This paper introduces a new type of hybrid truss system composed of glue laminated bamboo (glubam) for web and upper chord members and steel pipes for lower chords. Several experiments of physical and mechanical properties were carried out on the glubam material for structural design and construction according to timber specifications and codes. A full-scale space truss model with different configurations was constructed and tested under gravity loads. Different failure modes, such as buckling of web chords, shear fracture of bolted connecting joints and yield of bottom steel pipes, were discussed. Analyses of the structural behavior under static load are compared with the experimental results, showing a good agreement. The experimental results validate that the space truss system is of excellent load carrying capacity. If yielding of the lower chord steel pipes can be realized, the system can also have a large plastic deformation under the ultimate loading condition. A prototype structure was successfully designed and constructed as a rain-shed canopy of an office building.
Stress is an external event or condition that places a strain on a biological system. The animal response to a stress involves the expenditure of energy to remove or reduce the impact of the stress. ...This increases maintenance requirements of the animal and results in loss of production. The biological response to stress is divided into acute and chronic phases, with the acute phase lasting hours to a few days and the chronic phase lasting several days to weeks. The acute response is driven by homeostatic regulators of the nervous and endocrine systems and the chronic phase by homeorhetic regulators of the endocrine system. Both responses involve alterations in energy balance and metabolism. Thermal environment affects all animals and therefore represents the largest single stressor in animal production. Other types of stressors include housing conditions, overcrowding, social rank, disease, and toxic compounds. “Acclimation” to a stress is a phenotypic response developed by the animal to an individual stressor within the environment. However, under natural conditions, it is rare for only one environmental variable to change over time. “Acclimatization” is the process by which an animal adapts to several stressors within its natural environment. Acclimation is a homeorhetic process that takes several weeks to occur and occurs via homeorhetic, not homeostatic, mechanisms. It is a phenotypic change that disappears when the stress is removed. When the stress is severe and not relieved by acclimatization or management changes, the animal is considered chronically stressed and is susceptible to increased incidence of disease and poor health. Milk yield and reproduction are extremely sensitive to stress because of the high energy and protein demands of lactation and the complexity of the reproductive process and multiple organs that are involved. Improvements in protection of animals against stress require improved education of producers to recognize stress and methods for estimating degree of stress on animals.
Ecdysone receptor (EcR) is the hormonal receptor of ecdysteroids and strictly regulates growth and development in insects. However, the action mechanism of EcR is not very clear. In this study, the ...cDNA of EcR isoform‐B was cloned from Apolygus lucorum (AlEcR‐B) and its expression profile was investigated. We reduced AlEcR‐B mRNA expression using systemic RNA interference in vivo, and obtained knockdown specimens. Examination of these specimens indicated that AlEcR‐B is required for nymphal survival, and that reduced expression is associated with longer development time and lower nymphal weight. To investigate the underlying molecular mechanism of the observed suppression effects, we selected trehalase for a detailed study. Transcript encoding soluble trehalase (AlTre‐1) was up‐regulated by 20‐hydroxyecdysone and in agreement with the mRNA expression of AlEcR‐B. The expression profile of AlTre‐1, soluble trehalase activity and translated protein level in the midgut of surviving nymphs were down‐regulated, compared with controls, after the knockdown expression of AlEcR‐B. By contrast, membrane‐bound trehalase activity, the related gene expression and translated protein level remained at their initial levels. However, trehalose content significantly increased and the glucose content significantly decreased under the same conditions. We propose that AlEcR‐B controls normal carbohydrate metabolism by mediating the expression of AlTre‐1 to regulate the growth and development in A. lucorum, which provide an extended information into the functions of AlEcR‐B.
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