Characterized by light weight and high strength, composites are widely used as protective materials in dynamic impact loading under extreme conditions, such as high strain rates. Therefore, based on the excellent tensile properties of continuous fiber and the good flexibility and toughness of the bionic spiral structure, this study uses a multi-material 3D printer to incorporate continuous fiber, and then modifies the G-CODE file to control the printing path to achieve the production of a continuous fiber-reinforced Polylactic Acid composite helicoidal (spiral angle 60°) structure (COF-HP). Dynamic behavior under high-strain-rate impact experiments have been conducted using the Split Hopkinson Pressure Bar (SHPB). Stress-strain curves, impact energy curves and high-speed camera photographs with different strain rates at 680 s-1 and 890 s-1 have been analyzed to explore the dynamic process and illustrate the damage evolution. In addition, some detailed simulation models considering the incorporation of continuous optical fiber (COF) and different strain rates have been established and verified for deeper investigations. The results show that the COF does enhance the impact resistance of the laminates. When the porosity is reduced, the maximum stress of the continuous fiber-reinforced composite material is 4~7% higher than that of the pure PLA material. Our findings here expand the application of COF and provide a new method for designing protective materials, which have broad application prospects in the aerospace and automotive industries.
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http://dx.doi.org/10.3390/polym15234599 | DOI Listing |
J Clin Tuberc Other Mycobact Dis
December 2024
Department of Microbiology and Virology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran.
Background: Leprosy is a chronic infectious disease caused by () However, the emergence of drug-resistant strains of this bacterium, especially multidrug-resistant (MDR) strains, is a serious concern. This study aimed to evaluate the global prevalence of MDR and its implications.
Methods: Using PRISMA guidelines, we systematically reviewed ISI Web of Science, MEDLINE, and EMBASE up to August 2023 to assess the prevalence of MDR .
Front Microbiol
December 2024
College of Biology, Hunan University, Changsha, China.
Introduction: Dengue viruses (DENVs), the causative agents of dengue hemorrhagic fever and dengue shock syndrome, undergo genetic mutations that result in new strains and lead to ongoing global re-infections.
Objectives: To address the growing complexity of identifying and tracking biological samples, this study screened RNA barcode segments for the four DENV serotypes, ensuring high specificity and recall rates for DENV identification using segments.
Results: Through analyzing complete genome sequences of DENVs, we screened eight barcode segments for DENV, DENV-1, DENV-2, DENV-3, and DENV-4 identification.
Front Microbiol
December 2024
Department of Laboratory Medicine, Guangdong Provincial Hospital of Chinese Medicine, Zhuhai, China.
Background: Previous microbiological investigations have demonstrated a significant correlation between complex (CKC) infection and mastitis. Recent studies have confirmed the existence of the CKC, with () identified as the primary infectious agent. Examining the incidence of CKC in cases of severe non-lactational mastitis, alongside the clinical characteristics of infected patients, as well as evaluating the drug sensitivity testing protocols for CKC, can provide a more robust foundation for the diagnosis and treatment of CKC infections.
View Article and Find Full Text PDFDifferentiated service delivery (DSD) models in resource-limited settings have reduced strain on health services and improved client experience, retention and viral suppression, but little is known about the impact of HIV DSD models on quality of life (QoL), which is essential for optimizing person-centered care. This study assessed the impact of DSD models on QoL, loss to follow-up (LTFU), and mortality among persons living with HIV (PLHIV) on ART over time at a large urban HIV clinic in Uganda. We analyzed records of 1,000 PLHIV who had been on ART for 10 years and followed up for eight years, starting in 2014 or 2015 at the Infectious Diseases Institute clinic in Kampala, Uganda.
View Article and Find Full Text PDFSexual and gender minority young adult (SGM YA) populations use tobacco at higher rates than their non-SGM YA peers. Prior studies have identified significant correlations between interpersonal stigma and tobacco use, yet structural stigma may also influence tobacco use among SGM YA. This study aimed to assess the indirect effects of structural stigma on current tobacco use among SGM YA and non-SGM YA via depletion of economic resources, interpersonal discrimination, and perceived psychological stress.
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