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Methods of evaluating mechanical properties of 3D printed occlusal device materials: Flexural strength, fracture toughness, and impact strength
No full textSTATEMENT OF PROBLEM: The best method of characterizing the strength of 3-dimensionally (3D) printed occlusal devices is unknown. PURPOSE: The purpose of this in vitro study was to compare the flexural strength, flexural modulus, fracture toughness, and impact strength of flexible and stiff 3D printed occlusal device materials with those of milled and conventionally processed materials under wet and dry conditions. MATERIAL AND METHODS: Specimens were fabricated from flexible (KeySplint Soft, NightGuard Flex 2) and stiff (KeySplint Hard, NightGuard Firm) 3D printed resins using a Digital Light Processing (DLP) printer and milled (ProArt CAD) and heat-polymerized (Excel Formula) materials. Specimen dimensions varied based on testing: flexural strength and flexural modulus (65×10×3.3 mm), toughness (4×8×39 mm, 3-mm cut with a 100- to 400-µm notch), and impact strength (63.5×12.7×4 mm, 1.2 mm, 45-degree notch). Specimens were stored wet (37 °C, 48 h) or dry (37 °C in water and then air dried for 24 h). Flexural strength and flexural modulus and fracture toughness were tested on a universal testing machine until fracture or 15-mm deflection, while impact strength was assessed with an Izod impact machine (7.5 J, 150 degrees). Data were analyzed using 2-way ANOVA and Tukey tests (α=.05). RESULTS: Milled and heat-polymerized materials demonstrated higher flexural strength and flexural modulus than stiff 3D printed materials, which outperformed flexible 3D printed materials. Fracture toughness was better in milled and heat-polymerized materials under dry conditions, but one flexible 3D printed material outperformed all others under wet conditions. Flexible 3D printed materials exhibited significantly higher impact strength under both conditions. CONCLUSIONS: Flexible 3D printed occlusal device materials excel in impact strength and show variable performance in other mechanical properties depending on material type and testing conditions
Health Risk Assessment of Heavy Metal(loid)s Intake from Beverages in the United States
Get PDFHeavy metals in beverages can pose health risks in an exposure-dependent manner, however, few studies in the United States have evaluated their metal content and health risks. This study determined the concentrations of eight metal(loid)s, As, Al, Cd, Cr, Mn, Ni, Pb, and Zn, in 60 beverages via inductively coupled plasma[sbnd]mass spectrometry (ICPMS). The highest median concentrations (µg/kg) were found in mixed fruit juices for Ni (45.7), Cr (14.8), and As (4.5); tea for Mn (5,300), Al (730), and Pb (1.4); and plant-based milk for Zn (835) and Cd (1.1). Chronic daily intake (CDI) across age groups was calculated using the National Health and Nutrition Examination Survey (NHANES). Potential noncarcinogenic health risks were assessed via Hazard Quotients (HQ), and Hazard Indices (HI) for all elements and incremental lifetime cancer risk (ILCR) was assessed for total As, Cd, Ni, and Pb. About 58–67 % of the samples showed no noncarcinogenic risk (HQ and HI \u3c 1). HQ \u3e 1 was found in 19 samples for As, Zn, Ni, and Mn, and HI \u3e 1 in 6 additional samples (n = 25), mostly affecting children under 10, with three samples posing risk beyond adolescence. Significant carcinogenic risk (10−2 to 10−4) was found for As, Cd, and Ni across all beverage categories. This study highlights the need for consumer awareness and policy review
Ixekizumab demonstrates targeted protection against psoriatic arthritis in psoriasis patients: A multicenter retrospective cohort analysis
No full textCellular Tropism and Viral Genetics in Appendix Tissue Reservoirs of Subtype C HIV-1 Infected Aviremic Persons
No full textINTRODUCTION: Although antiretroviral therapy (ART) can suppress plasma viral loads in people living with HIV-1 (PLWH), it cannot eliminate HIV-1 proviruses persisting in various tissue reservoirs, and HIV-1 will rebound after ART cessation. We have recently identified the appendix as a novel HIV tissue reservoir, but nothing is known about the provirus and the cellular tropism in this tissue. METHODS: We utilized single genome analysis of HIV-1 env DNA and compared the viral sequences from appendix tissues and lymph nodes of the same PLWH. Sequential multiplex immunofluorescence labeling and RNAscope in situ hybridization on formalin-fixed paraffin-embedded appendix sections were performed to identify cell types harboring HIV-1 proviral DNA in the appendix, by visualizing viral and cellular biomarkers co-localization. RESULTS: The viral populations from the appendix were less heterogeneous compared to the lymph nodes in aviremic individuals, suggesting there is reduced ART selective pressure or the presence of appendix tropic HIV-1. Furthermore, we demonstrated that the follicular dendritic cell (FDC), rather than CD4+ T cell within the appendix is the major cell type harboring subtype C HIV-1. Notably, although some subtype C HIV-1 signals could be remaining virions captured by FDCs even in aviremic individuals, HIV-1 proviral DNA was detected in some FDCs in the appendix tissues of aviremic individuals, indicating the presence of infected FDCs. CONCLUSIONS: These results highlight the importance of analyzing all potential tissue and cellular tropism across different HIV-1 subtypes, to inform tailored therapeutic strategies for the diverse reservoirs that may differ across subtypes
Soluble CD13 is a potential mediator of neutrophil-induced thrombogenic inflammation in SARS-CoV-2 infection
Get PDFThe soluble variant of the ectopeptidase CD13 (sCD13), released from the cell surface by matrix metalloproteinase 14 (MMP14), is a potent pro-inflammatory mediator, displaying chemotactic, angiogenic, and arthritogenic properties through bradykinin receptor B1 (B1R). We revealed a link between sCD13 and amplified neutrophil-mediated inflammatory responses in SARS-CoV-2 infection. sCD13 was markedly elevated in patients with COVID-19 and correlated with disease severity and variants, ethnicity, inflammation markers, and neutrophil extracellular trap formation (NETosis). Neutrophils treated with sCD13 showed heightened NETosis and chemotaxis, which were inhibited by sCD13 receptor blockade. Meanwhile sCD13 did not induce platelet aggregation. Single-cell analysis of COVID-19 lungs revealed coexpression of CD13 and MMP14 by various cell types, and higher CD13 expression compared with controls. Neutrophils with high CD13 mRNA were enriched for genes associated with immaturity, though CD13 protein expression was lower. Histological examination of COVID-19 lungs revealed CD13-positive leukocytes trapped in vessels with fibrin thrombi. Flow cytometry verified the presence of B1R and a second sCD13 receptor, protease-activated receptor 4, on monocytes and neutrophils. These findings identify sCD13 as a potential instigator of COVID-19-associated NETosis, potentiating vascular stress and thromboembolic complications. The potent pro-inflammatory effects of sCD13 may contribute to severe COVID-19, suggesting that sCD13 and its receptors might be therapeutic targets
Supercharged and Delayed Thoracodorsal and Dorsal Intercostal Artery Perforator Flaps for Autologous Breast Reconstruction
Get PDFIn patients seeking total autologous breast reconstruction following mastectomy, prior abdominal surgery can present as a contraindication to utilizing traditional abdominal-based free flaps. The thoracodorsal artery perforator (TDAP) flap has emerged as a suitable alternative, providing adequate tissue and minimal donor site morbidity. This case report demonstrates further improvement to this technique by utilizing the dorsal intercostal artery perforator vessels to supercharge this pedicled flap, along with a surgical delay of the TDAP and dorsal intercostal artery perforator. This adaptation can provide added bulk and improved perfusion to the traditional TDAP-based total autologous breast reconstruction
Methods for community-engaged data collection and analysis in implementation research
Get PDFBACKGROUND: Community engagement is widely recognized as critical to successful and equitable implementation of evidence-based practices, programs, and policies. However, there are no clear guidelines for community involvement in data collection and analysis in implementation research. METHODS: We describe three specific methods for engaging community members in data collection and analysis: concept mapping, rapid ethnographic assessment, and Photovoice. Common elements are identified from a case study of each method: 1) selection and adaptation of evidence-based strategies for improving adolescent HPV vaccine initiation rates in disadvantaged communities, 2) strategies for implementing medication for opioid use disorders among low-income Medicaid enrollees during natural disasters, and 3) interventions to improve the physical health of adults with severe mental illness living in supportive housing. RESULTS: In all three cases, community members assisted in participant recruitment, provided data, and validated preliminary findings created by researchers. In the Photovoice case study, community members participated in both data collection and analysis, while in the concept mapping, community members also participated in the initial phase of organizing and prioritizing evidence-based strategies during the data analysis. CONCLUSIONS: Community involvement in implementation research data collection and analysis contributes to greater engagement and empowerment of community members and validation of study findings. Use of methods that exhibit both scientific rigor and community relevance of implementation research also contributes to greater community investment in successful implementation outcomes. Nevertheless, the case studies point to the importance and efficiency of the division of labor embedded in community-engaged implementation research. Building capacity for community members to assume greater roles in obtaining and organizing data for preliminary analysis prior to interpretation is recommended