Abstract
The paper proposes a class of tunable metamaterials that use inclined beams to achieve instability in a rigid system. Three different beam tilt angles, 25°, 45°, and 60°, are evaluated in ...the form of unit cells using quasi-static compression tests and numerical simulations. Snap-through behavirous are characterised by structural stiffness and buckling load. Periodic and gradient structures are assembled and analysed by arranging the unit cells in rows and columns. Size effect analyses and parametric studies are carried out on various unit-cell arrangements and different beam angles. The proposed metamaterials are manufactured through fused filament fabrication 3D printing technology with a composite material, onyx. The results from experiments, finite element analysis, and analytical models are compared and evaluated. The structural stiffness and buckling load are shown to be positively related to the inclination angle of the tilted beams. The number of rows of unit cells governs the nonlinear mechanical response (number of snap-throughs) of multiple-layered structures. By increasing the number of rows and columns of unit cells, which are less prone to manufacturing defects, the reliability and repeatability of the structural properties of periodic/gradient structures could be improved. A design plot is also provided to predict and tune the snap-through behaviour of multiple-layered structures via beam angles and unit-cell arrangements.
Previous research has shown that patients with chronic obstructive pulmonary disease (COPD) tend to have a higher risk for cognitive impairment and dementia, a neurodegenerative disorder. The goal of ...this study was to examine what relationship, if any, exists between COPD and Parkinson's disease (PD), which is also a neurodegenerative disorder.
Our study analyzed medical data from the population of Taiwan from 1998 to 2008, with a follow-up period extending to the end of 2010. We identified patients with COPD by the Taiwan National Health Insurance Research Database (NHIRD). We selected a comparison cohort from the general population that was random frequency-matched by age (in 5-year increments), sex and index year, and further analyzed the risk of PD using Cox's regression model, including sex, age and comorbidities.
The study enrolled 20 728 COPD patients (71.1% male, mean age = 68.2 years) and 41 147 controls. The risk of developing PD was 1.37 times greater in patients with COPD compared with patients without COPD after adjusting for age, sex and comorbidities. A significantly increased risk of PD was also found in patients with COPD who had any comorbidity other than diabetes.
This nationwide retrospective cohort study demonstrates that PD risk is significantly increased in patients with COPD compared with those of the general population.
Summary
Porcine postweaning multisystemic wasting syndrome (PMWS) caused by porcine circovirus type 2 (PCV2) is a disease causing severe economic losses annually worldwide to the pig industry. PCV2 ...infection was first reported in China in 2000, and currently has three major genotypes, PCV2a, b and d, circulating in this country. To further elucidate the origin and prevalence of PCV2 in China, 123 clinical pig tissue samples collected in 25 provinces between 1990 and 1999 were analysed by PCV2‐specific PCR, resulting in identification of 23 PCV2 strains collected between 1996 and 1999. Phylogenetic analysis based on the nucleotide sequences of open reading frame 2 (ORF2) showed that 20 of the 23 grouped within PCV2a, while the remaining three strains formed an independent clade, so far unreported and therefore named PCV2f. This genotype shared lower sequence identity with other known genotypes. This study provides further understanding of the genetic diversity and evolution of PCV2 and has tracked PCV2 infection in China back to 1996 rather than 2000.
All purple photosynthetic bacteria contain RC–LH1 ‘Core’ complexes. The structure of this complex from
Rhodobacter sphaeroides
,
Rhodopseudomonas palustris
and
Thermochromatium tepidum
has been ...solved using X-ray crystallography. Recently, the application of single particle cryo-EM has revolutionised structural biology and the structure of the RC–LH1 ‘Core’ complex from
Blastochloris viridis
has been solved using this technique, as well as the complex from the non-purple Chloroflexi species,
Roseiflexus castenholzii
. It is apparent that these structures are variations on a theme, although with a greater degree of structural diversity within them than previously thought. Furthermore, it has recently been discovered that the only phototrophic representative from the phylum Gemmatimonadetes,
Gemmatimonas phototrophica
, also contains a RC–LH1 ‘Core’ complex. At present only a low-resolution EM-projection map exists but this shows that the
Gemmatimonas phototrophica
complex contains a double LH1 ring. This short review compares these different structures and looks at the functional significance of these variations from two main standpoints: energy transfer and quinone exchange.
Summary
Babesia spp., Theileria spp. and Anaplasma ovis are important intracellular agents that are transmitted by tick bites. However, Babesia spp., Theileria spp. and A. ovis in ticks have not been ...systematically reported along the border of northwestern China. In this study, a total of 1,084 adult ticks, including 134 Haemaphysalis punctata, 337 Hyalomma asiaticum, 233 Dermacentor nuttalli, 69 Rhipicephalus turanicus and 265 Dermacentor marginatus were collected from 11 counties or cities of Xinjiang Uygur Autonomous Region. The ticks were identified from morphological and molecular characteristics. Two fragments of 18S rRNA gene were used to determine the species level of Babesia and Theileria. Msp4 gene encoding major surface protein 4 was used to determine A. ovis. Of the 1,084 samples, five species of Babesia (B. occultans, B. caballi, B. motasi, B. major and Babesia sp. detected in this study), two kinds of Theileria (Theileria ovis and Theileria sp. detected in this study) and A. ovis with six phylogenic branches were detected in the border of northwestern China. Babesia occultans, first found in China, was first molecularly detected in D. nuttalli. Babesia caballi and Babesia sp. detected in this study were first molecularly detected in Hy. asiaticum. Genotype III of A. ovis was predominant in the border regions of northwestern China.
Zein, which accounts for around 80% of the total protein composition in corn, is a biocompatible and biodegradable substance derived from renewable sources. Although insoluble in water, its ...amphiphilic characteristics are utilized to generate nanoparticles, nanofibers, microparticles, and even films. Numerous recent studies have demonstrated the potential of zein as a prospective biomaterial to develop fibrous scaffolds for biomedical functions owing to its biocompatibility, fibrous formation, and encapsulating qualities. Fabrication of zein‐based fibrous scaffolds for biomedical applications is achieved by a wide variety of techniques, including electrospinning, wet spinning, freeze drying, and additive manufacturing. This article overviews current advancements in manufacturing techniques for zein‐based fibrous scaffolds. In addition, it summarizes the most recent biomedical applications and research activities utilizing zein‐based fibrous scaffolds. Overall, zein is proposed as a potential biomaterial for the production of fibrous scaffolds that stimulate cell adhesion and proliferation in a number of exciting biomedical applications due to its biodegradability, biocompatibility, and other unique features related to its structure.
This article spotlights zein as a potential biomaterial for fabriction of fibrous scaffolds in diverse biomedical applications. It introduces unique features of zein and explores the latest manufacturing advancements, applications, and research on zein fibrous scaffolds. The article concludes with a critical analysis of current state and offers suggestions for future research in this field.
The relationship between tuberculosis (TB) and subsequent chronic kidney disease (CKD) remains unclear. Therefore, we examined the risk of CKD among patients with TB in a nationwide study.
We ...conducted a retrospective cohort study using data from the National Health Insurance system of Taiwan. The cohort included 8735 patients who were newly diagnosed with TB. Patients were recruited between 1998 and 2002, and the date of diagnosis was defined as the index date. Each patient was randomly matched with four people from the general population without TB, according to age, gender and the index year. The occurrence of CKD was followed up until the end of 2011. The relative risks of CKD were estimated using the Cox proportional hazard model after adjusting for age, gender, index year and comorbidities.
The overall incidence of CKD was 1.27-fold greater in the TB cohort than in the non-TB cohort. The adjusted hazard ratio (HR) of CKD associated with TB was higher in women (1.72; 95% confidence interval CI: 1.33-2.22), those aged <50 years (1.67; 95% CI: 1.15-2.41) and those without comorbidities (1.39; 95% CI: 1.06-1.83). In addition, patients with more comorbidities among hypertension, diabetes and hyperlipidemia have a greater risk of developing CKD in both cohorts, and the adjusted HRs were higher in the TB cohort than in the non-TB cohort.
TB patients had a significantly higher risk of developing CKD than the general population. The detailed mechanisms need further investigation.
Hepatocellular carcinoma (HCC) is the most common type of liver cancer. Despite the availability of several treatment strategies, resistance to chemotherapeutic agents, which limits the effectiveness ...of anticancer drugs, is a major problem in cancer therapy. In this study, we used a histone deacetylases inhibitor (HDACi) to establish drug-resistant HCC cells and further analyzed the molecular mechanisms underlying the development of resistance in HCC cells. Compared with the parental cells, HDACi-resistant cells showed high metastatic and pro-survival abilities. Two-dimensional electrophoresis data showed that the cofilin-1 (CFL-1) protein was altered in HDACi-resistant cells and was highly expressed in resistant cells compared with parental cells. The molecular function of CFL-1 is actin depolymerization, and it is involved in tumor metastasis. In this study, we showed that CFL-1 inhibition decreased cell migration and increased cell apoptosis in HDACi-resistant cells. We observed that HDACi induced ROS accumulation in cells and apoptosis via promotion of the CFL-1 interaction with Bax and CFL-1 translocation to the mitochondria, resulting in cytochrome C release. Importantly, phosphorylation of CFL-1 by activated extracellular signal-regulated kinases 1 and 2 (ERK1/2) confers strong protection against HDAC inhibitor-induced cell injury. p-CFL-1 shows a loss of affinity with Bax and will not translocate to mitochondria, stably remaining in the cytoplasm. These results indicate that phosphorylation to inactivate CFL-1 decreased the chemosensitivity to HDAC inhibitors and resulting in drug resistance of HCC cells.
The emergence of liquid metal catalysts endows electrocatalytic processes with enhanced efficiencies by eliminating coking issues that rapidly deactivate conventional solid catalysts. Alloying them ...with trace amounts of redox-active metal additives can further improve their catalytic activity. Here we report a vanadium-liquid metal alloy with superior activity that can drive electrochemical reduction of CO
2
into solid carbon. The reaction mechanism has been thoroughly investigated and discussed. In addition, artificial neural networks trained by machine learning have been demonstrated to be powerful in predicting performance of LM alloys with various compositions.
An electrocatalyst with trace vanadium alloyed with liquid metal reduces CO
2
directly into solid carbon.
The evaluation and interpretation of the behavior of construction materials under fire conditions have been complicated. Over the last few years, artificial intelligence (AI) has emerged as a ...reliable method to tackle this engineering problem. This review summarizes existing studies that applied AI to predict the fire performance of different construction materials (e.g., concrete, steel, timber, and composites). The prediction of the flame retardancy of some structural components such as beams, columns, slabs, and connections by utilizing AI-based models is also discussed. The end of this review offers insights on the advantages, existing challenges, and recommendations for the development of AI techniques used to evaluate the fire performance of construction materials and their flame retardancy. This review offers a comprehensive overview to researchers in the fields of fire engineering and material science, and it encourages them to explore and consider the use of AI in future research projects.
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