In Vitro Inflammatory Cell-Induced Corrosion Using a Lymphocyte and Macrophage Co-Culture.

INTRODUCTION: Cobalt-chromium-molybdenum (CoCrMo) and titanium alloys have been used for orthopaedic implants for decades. However, recent evidence has shown that inflammatory cell-induced corrosion (ICIC) can damage these metal alloys. This study aimed to investigate the mechanisms of ICIC by co-culturing macrophages with lymphocytes. We hypothesized that macrophages would be able to alter the surface oxide layer of CoCrMo and titanium alloy (Ti6Al4V) disks, with greater oxide layer damage occurring in groups with a co-culture compared to a macrophage monoculture and in groups with inflammatory activators compared to nonactivated groups. METHODS: Murine macrophages were cultured on American Society for Testing and Materials (ASTM) F1537 CoCrMo and ASTM F136 Ti6Al4V disks for 30 days and activated with interferon gamma and lipopolysaccharide. Interferon gamma and lipopolysaccharide were added to the culture medium to simulate local inflammation. Macrophages were either cultured alone or in a co-culture with T helper lymphocytes. After the 30-day experiment, scanning electron microscopy was used to examine the disk surfaces, and oxide levels were found using energy dispersive x-ray spectroscopy. RESULTS: Pitting features consistent with previous reports of ICIC were found on disks cultured with cells. Both CoCrMo and Ti6Al4V disks had significantly lower oxide levels in all groups with cells compared to control groups with no cells (P < 0.01). Additionally, CoCrMo disks had significantly lower oxide levels when cultured with activated macrophages and lymphocytes compared to nonactivated macrophages alone (P < 0.001), activated macrophages alone (P < 0.01), and nonactivated macrophages and lymphocytes (P < 0.05). No differences in the oxide levels were found among the Ti6Al4V groups. CONCLUSION: This study demonstrates the ability of macrophages to alter the surface chemistry of commonly used orthopaedic alloys. We found that the addition of lymphocytes and a simulated local inflammatory response may contribute to the ICIC of CoCrMo implants.

Working viscosity and non-Newtonian behavior of silicone denture liners.

PURPOSE: To evaluate flow profile and non-Newtonian behavior of 10 different silicone lining materials. METHODS: Ten commercially available silicone lining materials were selected for evaluation. The flow profile and non-Newtonian behavior of each material was measured using a shark fin testing method. Fin height and resultant base thickness were measured with a digital caliper and compared with one-way ANOVA and Student-Newman-Keuls post hoc test and fin base by Kruskal-Wallis one-way ANOVA on ranks with Dunn post hoc test with significance at P< 0.05 for both. RESULTS: Shark fin heights ranged from 9.62 ± 0.86 mm [Reline II (Soft)] to 25.54 ± 0.43 mm [Sofreliner (Medium)]. Shark fin bases ranged from 2.57 ± 0.51 mm [Sofreliner (Medium)] to 10.31 ± 0.57 mm [Reline II (Soft)]. Statistically significant differences were found between certain samples' shark fin heights as well as resultant bases (P< 0.05) indicating different rheological properties. CLINICAL SIGNIFICANCE: Silicone liner materials differ significantly with respect to flow profile and non-Newtonian behavior. While a high flow profile (low viscosity) of an elastomeric impression material improves accuracy, it may be a detriment to a denture lining material that must achieve a critical minimum thickness to provide resilience. Likewise, a low flow profile (high viscosity) material may also pose a disadvantage, requiring excessive compression and possible tissue distortion to achieve the same critical thickness. The results of this study should be considered when selecting the appropriate material for clinical application. Additional studies are indicated to further quantify rheological properties as well as correlate them to physical properties after the complete cure of the material.

Effect of different storage media on elemental analysis and microhardness of cervical cavity margins restored with a bioactive material.

Objectives: This study aimed to investigate the elemental analysis and microhardness of a bioactive material (Activa) and marginal tooth structure after storage in different media. Materials and Methods: Fifteen teeth received cervical restorations with occlusal enamel and gingival dentin margins using the tested material bonded with a universal adhesive, 5 of them on the 4 axial surfaces and the other 10 on only the 2 proximal surfaces. The first 5 teeth were sectioned into 4 restorations each, then stored in 4 different media; deionized water, Dulbecco's phosphate buffered saline (DPBS), Tris buffer, and saliva. The storage period for deionized water was 24 hours while it was 3 months for the other media. Each part was analyzed by scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis for different substrates/distances and the wt% of calcium, phosphorus, silica, and fluoride were calculated. The other 10 teeth were sectioned across the restoration, stored in either Tris buffer or saliva for 24 hours or 3 months, and were evaluated for microhardness of different substrates/areas. Data were analyzed using analysis of variance and Tukey's post hoc test. Results: Enamel and dentin interfaces in the DPBS group exhibited a significant increase in calcium and phosphorus wt%. Both silica and fluoride significantly increased in tooth structure up to a distance of 75 µm in the 3-month-media groups than the immediate group. Storage media did not affect the microhardness values. Conclusions: SEM-EDS analysis suggests an ion movement between Activa and tooth structure through a universal adhesive while stored in DPBS.

Mechanical properties of conventional versus microwave-polymerized denture base acrylic resins.

STATEMENT OF PROBLEM: New denture base acrylic resins have been introduced that are specifically formulated for microwave polymerization. Microwave polymerization is a time-efficient procedure, but few studies have evaluated how these new acrylic resin formulations compare with conventionally processed acrylic resins. PURPOSE: The purpose of this in vitro study was to compare the stiffness and strength of denture base acrylic resins formulated for microwave polymerization with conventionally processed acrylic resin. MATERIAL AND METHODS: Rectangular beams were fabricated from 2 microwave-polymerized denture base acrylic resins, microwave-specific resin (Nature-Cryl MC), resin with the option of microwave polymerization (Diamond D), and a conventionally processed resin as a control (Lucitone 199). Specimens (n=10) were stored in water for 1 week and subjected to a 3-point bend test to determine the flexural modulus (stiffness) and flexural strength before (initial properties) or after 120 000 load cycles. The load cycles, conducted between 5 and 25 N at 2 Hz, simulated 6 months of mastication. Data were analyzed by using 2-way ANOVA, followed by pairwise comparisons (α=.05). RESULTS: The initial flexural modulus (mean ±standard deviation) was conventionally processed resin, 2.65 ±0.33 GPa; microwave-specific resin, 3.01 ±0.20 GPa; and microwave-option resin, 2.63 ±0.04 GPa. After load cycling, the mean flexural modulus was conventionally processed resin, 2.34 ±0.32 GPa; microwave-specific resin, 2.69 ±0.20 GPa; and microwave-option resin, 1.96 ±0.11 GPa. The initial flexural strength was conventionally processed resin, 77.6 ±11.0 MPa; microwave-specific resin, 83.6 ±3.5 MPa; and microwave-option resin, 78.9 ±2.6 MPa. After load cycling, the mean flexural strength was conventionally processed resin, 68.7 ±9.0 MPa; microwave-specific resin, 73.3 ±3.3 MPa; and microwave-option resin, 65.5 ±3.5 MPa. Resin and loading state significantly affected the stiffness and strength (P<.01); the interaction resin×state was not significant (P≥.558). CONCLUSIONS: Microwave-polymerized denture base acrylic resins were comparable in stiffness and strength with conventionally processed acrylic resin. All acrylic resins decreased in stiffness and strength after load cycling. The microwave-specific resin was significantly stiffer and stronger than the other denture base acrylic resins, initially and after 120 000 load cycles.

Effects of -H and -OH Termination on Adhesion of Si-Si Contacts Examined Using Molecular Dynamics and Density Functional Theory.

The contact between nanoscale single-crystal silicon asperities and substrates terminated with -H and -OH functional groups is simulated using reactive molecular dynamics (MD). Consistent with previous MD simulations for self-mated surfaces with -H terminations only, adhesion is found to be low at full adsorbate coverages, be it self-mated coverages of mixtures of -H and -OH groups, or just -OH groups. As the coverage reduces, adhesion increases markedly, by factors of ∼5 and ∼6 for -H-terminated surfaces and -OH-terminated surfaces, respectively, and is due to the formation of covalent Si-Si bonds; for -OH-terminated surfaces, some interfacial Si-O-Si bonds are also formed. Thus, covalent linkages need to be broken upon separation of the tip and substrate. In contrast, replacing -H groups with -OH groups while maintaining complete coverage leads to negligible increases in adhesion. This indicates that increases in adhesion require unsaturated sites. Furthermore, plane-wave density functional theory (DFT) calculations were performed to investigate the energetics of two Si(111) surfaces fully terminated by either -H or -OH groups. Importantly for the adhesion results, both DFT and MD calculations predict the correct trends for the relative bond strengths: Si-O > Si-H > Si-Si. This work supports the contention that prior experimental work observing strong increases in adhesion after sliding Si-Si nanoasperities over each other is due to sliding-induced removal of passivating species on the Si surfaces.

Longevity of extrinsic stains on monolithic zirconia restorations: An in vitro study.

STATEMENT OF PROBLEM: Three-mol% yttria-stabilized tetragonal zirconia polycrystal (3Y-TZP) has been commonly used for fixed prosthodontic restorations. The opacity of 3Y-TZP may be masked with external staining, although the longevity of extrinsic stains applied to monolithic zirconia is unclear. PURPOSE: The purpose of this in vitro study was to analyze the color and surface roughness of extrinsically stained zirconia specimens after thermocycling and toothbrushing. MATERIAL AND METHODS: Monolithic Ø12.5×1.25-mm zirconia disks were milled from 3Y-TZP blocks, sintered according to manufacturer instructions, and then divided into 3 groups (C, J, and O; n=16) for application of stain and glaze. All specimens underwent 10 000 thermocycles in distilled water before being further divided into 2 dentifrice groups (n=8): normal grit, low relative dentin abrasivity (RDA) (Subgroup N) and abrasive grit, high RDA (Subgroup A). Specimens were brushed in a multistation brushing machine under 1.47 N of force using a 5:8 toothpaste and distilled water slurry for 10 000 cycles with a straight (American Dental Association Standard) toothbrush to simulate 1 year of toothbrushing. Color and surface roughness measurements were obtained at 3 time points: baseline, after thermocycling, and after brushing. A 2-way repeated measures ANOVA was used to independently assess changes in color and surface roughness with respect to thermocycling and brushing (α=.05). RESULTS: Group J displayed no significant change in color for either dentifrice system (P>.05). However, a significant change in surface roughness was observed for both dentifrice subgroups (P<.001). Group C specimens displayed significant changes in color (P<.001) and surface roughness (P<.001) for both dentifrice systems. Group O specimens displayed significant changes in color (P<.025) for both dentifrice systems and significant changes in surface roughness (P<.004) for subgroup A, but no significant changes for subgroup N (P=.075). CONCLUSIONS: Artificial aging of monolithic zirconia resulted in changes in color and surface roughness that did not surpass the thresholds for perceptibility and acceptability. This study failed to establish durability limits for extrinsic stains applied to 3Y-TZP.

Microhardness of different thicknesses of bulk fill composites.

PURPOSE: To compare the microhardness values and bottom/top hardness ratios of different composites after being cured in 2 or 4 mm increments. METHODS: Two bulk fill composites, methacrylate-based and ormocer-based, and one conventional composite were tested. 36 cylindrical discs were prepared (n=12/composite, with six for 2 mm, and six for 4 mm thickness) by pressing each composite into a mold between two glass slides covered by Mylar strips. The top and bottom surfaces of each sample were evaluated using a Buehler hardness tester for Knoop microhardness, with a 50 g static load applied for 10 seconds at three different locations of the central part of each sample. The bottom/top hardness ratio was calculated for each sample. The Knoop microhardness data and bottom/top ratio percentages were analyzed using two-way repeated measures ANOVA and Holm-Sidak post hoc test, with significance at P< 0.05. RESULTS: The tested methacrylate-based bulk fill had the highest overall microhardness among the three tested composites. All three composite types showed a significant difference in microhardness between the top and bottom of the 4 mm discs. The bottom/top ratio percentages differed significantly for both tested bulk fill composites across different thicknesses. Both tested bulk fill materials had a bottom/top ratio of ≥ 80% at the deepest level of a 4 mm increment. CLINICAL SIGNIFICANCE: The type of material significantly affected both the bottom and top microhardness values under the experimental conditions used. While both tested bulk fill composites showed a decline in microhardness at the bottom of the 4 mm depth, they had clinically acceptable microhardness ratios at greater depths.

Comparative evaluation of subgingival scaling and polishing techniques on dental material surface roughness.

PURPOSE: To evaluate and compare the effects of different scaling and polishing techniques on the surface roughness of four different restorative materials. METHODS: 72 specimens were prepared, molded to a size of 8.0 by 2.0 mm, and cured according to the manufacturers' instructions. The specimens were stored at 37°C for 24 hours and then thermocycled for 5,000 cycles (from 55°C to 5°C) to simulate 6 months of clinical use. Surface roughness (Ra/average and Rz/max-overall heights) was calculated using a stylus profilometer by subtracting the simulated treatments of hand scaling, ultrasonic scaling, and air polishing from the baseline measurements. The difference in Ra and Rz data were compared independently for each measurement using a two-way ANOVA on Ranks and the Holm-Sidak test, with α< 0.05 used to determine significance. RESULTS: Irrespective of the scaling or polishing technique employed, flowable bulk fill demonstrated the lowest Ra and Rz values. Hand scaling exhibited the highest roughness and variability among the other techniques, regardless of the materials tested (P< 0.001). Air polishing with glycine resulted in the lowest roughness values across all tested materials, with the exception of the tested bioactive restorative material group. CLINICAL SIGNIFICANCE: Regarding surface roughness, air polishing with glycine may be an effective and safe intervention for periodontal maintenance of subgingival restorations compared to the other tested scaling methods.

Multivalent human antibody-centyrin fusion protein to prevent and treat Staphylococcus aureus infections.

Treating and preventing infections by antimicrobial-resistant bacterial pathogens is a worldwide problem. Pathogens such as Staphylococcus aureus produce an array of virulence determinants, making it difficult to identify single targets for the development of vaccines or monoclonal therapies. We described a human-derived anti-S. aureus monoclonal antibody (mAb)-centyrin fusion protein ("mAbtyrin") that simultaneously targets multiple bacterial adhesins, resists proteolysis by bacterial protease GluV8, avoids Fc engagement by S. aureus IgG-binding proteins SpA and Sbi, and neutralizes pore-forming leukocidins via fusion with anti-toxin centyrins, while maintaining Fc- and complement-mediated functions. Compared with the parental mAb, mAbtyrin protected human phagocytes and boosted phagocyte-mediated killing. The mAbtyrin also reduced pathology, reduced bacterial burden, and protected from different types of infections in preclinical animal models. Finally, mAbtyrin synergized with vancomycin, enhancing pathogen clearance in an animal model of bacteremia. Altogether, these data establish the potential of multivalent mAbs for treating and preventing S. aureus diseases.

Global Distribution of O Serotypes and Antibiotic Resistance in Extraintestinal Pathogenic Escherichia coli Collected From the Blood of Patients With Bacteremia Across Multiple Surveillance Studies.

BACKGROUND: Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of bacteremia worldwide, with older populations having increased risk of invasive bacterial disease. Increasing resistance to first-line antibiotics and emergence of multidrug-resistant (MDR) strains represent major treatment challenges. ExPEC O serotypes are key targets for potential multivalent conjugate vaccine development. Therefore, we evaluated the O serotype distribution and antibiotic resistance profiles of ExPEC strains causing bloodstream infections across 4 regions. METHODS: Blood culture isolates from patients aged ≥60 years collected during 5 retrospective E. coli surveillance studies in Europe, North America, Asia-Pacific, and South America (2011-2017) were analyzed. Isolates were O serotyped by agglutination; O genotyping was performed for nontypeable isolates. Antimicrobial susceptibility testing was also conducted. RESULTS: Among 3217 ExPEC blood culture isolates, the most ubiquitous O serotype was O25 (n = 737 [22.9%]), followed by O2, O6, O1, O75, O15, O8, O16, O4, O18, O77 group, O153, O9, O101/O162, O86, and O13 (prevalence of ≥1%). The prevalence of these O serotypes was generally consistent across regions, apart from South America; together, these 16 O serotypes represented 77.6% of all ExPEC bacteremia isolates analyzed. The overall MDR frequency was 10.7%, with limited variation between regions. Within the MDR subset (n = 345), O25 showed a dominant prevalence of 63.2% (n = 218). CONCLUSIONS: Predominant O serotypes among ExPEC bacteremia isolates are widespread across different regions. O25 was the most prevalent O serotype overall and particularly dominant among MDR isolates. These findings may inform the design of multivalent conjugate vaccines that can target the predominant O serotypes associated with invasive ExPEC disease in older adults.

Correlation between different methodologies used to evaluate the marginal adaptation of proximal dentin gingival margins elevated using a glass hybrid.

Objectives: This study aimed to evaluate the effect of aging on the marginal quality of glass hybrid (GH) material used to elevate dentin gingival margins, and to analyze the consistency of the results obtained by 3 in vitro methods. Materials and Methods: Ten teeth received compound class II cavities with subgingival margins. The dentin gingival margins were elevated with GH, followed by resin composite. The GH/gingival dentin interfaces were examined through digital microscopy, scanning electron microscopy (SEM) using resin replicas, and according to the World Dental Federation (FDI) criteria. After initial evaluations, all teeth were subjected to 10,000 thermal cycles, followed by repeating the same marginal evaluations and energy dispersive spectroscopy (EDS) analysis for the interfacial zone of 2 specimens. Marginal quality was expressed as the percentage of continuous margin at ×200 for microscopic techniques and as the frequency of each score for FDI ranking. Data were analyzed using the paired sample t-test, Wilcoxon signed-rank test, and Pearson and Spearmen correlation coefficients. Results: None of the testing techniques proved the significance of the aging factor. Moderate and strong significant correlations were found between the testing techniques. The EDS results suggested the presence of an ion-exchange layer along the GH/gingival dentin interface of aged specimens. Conclusions: The marginal quality of the GH/dentin gingival interface defied aging by thermocycling. The replica SEM and FDI ranking results had stronger correlations with each other than either showed with the digital microscopy results.

Impact of Metal Particles Released during Ultrasonic Scaling of Titanium Surfaces on Human Gingival Fibroblasts.

PURPOSE: Metal particles found in tissues around dental implants have been proposed to play a pathogenic role in peri-implantitis. Ultrasonic scaling has been suggested as a mechanism by which these particles can be inadvertently released into surrounding tissues. Furthermore, risk factors like diabetes can result in exacerbation of this inflammatory condition. The current study aimed to analyze metal particles released from titanium surfaces during ultrasonic scaling and their impact on pro-inflammatory cytokine production by human gingival fibroblasts. METHODS: Metal particles generated from ultrasonic scaling of titanium discs using two different tips (metal and poly-etheretherketone tips) were characterized using scanning electron microscopy and elemental analysis. Endotoxin levels and Human gingival fibroblast viability, in the presence commercial and ultrasonically generated particles were determined. Fibroblasts, cultured in high or low glucose growth medium, were incubated with commercial titanium particles or ultrasonically generated particles in the presence or absence of interluekin-1ß. Interleukin 6 and interleukin 8 production were then quantified using Enzyme linked immunosorbent assay. RESULTS: Analysis of particles after scaling of titanium discs showed significant levels of titanium particles. Commercial titanium particles and generated particles had no effect of fibroblast viability. Endotoxin levels of all particles were too low to stimulate HGF cells. IL-1ß significantly stimulated IL-6 and IL-8 production. However, commercial, and generated particles generally had no significant effect on IL- 6 and IL-8 production. CONCLUSION: Our study concluded that particles generated during ultrasonic scaling had no significant effect on viability of HGF cells and cytokine production.

Surface Roughness of Prefabricated Pediatric Zirconia Crowns Following Simulated Toothbrushing.

Purpose: The purpose of this study was to evaluate the surface roughness of three different brands of prefabricated pediatric zirconia crowns (ZRCs) following simulated toothbrushing with a variety of dentifrices. Methods: Ninety-six total maxillary right central incisor prefabricated pediatric ZRCs (n equals 32 ZRCs/brand) were obtained from the manufacturers: Kinder Krowns®, NuSmile®, and Sprig®. ZRCs were equally assigned to dentifrices (n equals eight/dentifrice) with a variety of Relative Dentin Abrasion (RDA) values: Tom's of Maine Children's; Crest Kid's; Prevident 5000; and Crest® Pro-Health. ZRCs were brushed 10,000 strokes with a V-8 Toothbrushing Machine using the assigned dentifrices. Pre- and post-intervention data for the surface roughness of ZRCs, represented in Ra (average roughness) and Rz (mean roughness depth), were obtained using a stylus profilometer. Data were analyzed independently using two-way repeated measures analysis of variance with the Holm- Sidak method (α equals 0.05). Results: Baseline versus brushed Ra Kinder Krowns® with Prevident and Sprig® with Crest Kid's indicated statistically significant differences. Sprig® versus NuSmile® utilizing Crest Kid's were different in change in roughness. Both baseline and brushed NuSmile® dentifrice options were different versus all Sprig® and Kinder® ZRCs. Conclusions: Despite statistical significance, changes in surface roughness were small in scale. Although this study did not address toothbrushing and different dentifrices may affect the mechanical properties, durability, and/or retention properties of ZRCs, the study's results provide confidence to clinicians when using prefabricated pediatric ZRCs as a sustainable treatment option along with other restorative options, such as strip crowns and stainless steel crowns.

Effect of whitening dentifrices on toothbrush abrasion on composites.

PURPOSE: To evaluate the laboratory long-term effect of various whitening dentifrices on the surface roughness of two brands of resin composite (TPH ST, Filtek Bulk Fill One) using a mechanical toothbrushing simulation. METHODS: Thirty-two samples each of Filtek and TPH were fabricated in ring molds 10 x 1 mm. Samples were randomly grouped (n=8; four groups), according to dentifrice used; Crest 3D, Optic White, Hello (charcoal), and Aim as control. Samples were brushed in mixed solutions containing deionized water and dentifrice at 150 gf for 10,000x with rotation to ensure uniform brushing. Surface roughness was measured both before (baseline) and after the mechanical toothbrushing simulation using a stylus profilometer. Data collected was compared independently for each treatment using two-way ANOVA and SNK with α< 0.05 for significance. RESULTS: The data showed that TPH was more susceptible to the abrasive nature of three of the whitening dentifrices tested [Crest 3D, Optic White, and Hello (charcoal) ]. Filtek also exhibited significant susceptibility to the abrasive nature of Hello. Aim showed the least or minimal amount of abrasion. CLINICAL SIGNIFICANCE: TPH ST composite was more susceptible to the abrasive nature of the three whitening dentifrices tested [Crest 3D, Optic White, and Hello (charcoal)]. Filtek also exhibited significant susceptibility to the abrasive nature of Hello. Aside from the data supporting the clinical efficacy of TPH compared to Filtek, clinicians should inform patients of the abrasive capacity of all whitening dentifrices, especially those that are charcoal based.

What would improve MS clinic services for cognition? - A stakeholder panel and survey exploration.

Cognitive difficulties in MS are widely acknowledged to have a major negative impact on the lives of people with MS (PwMS). However they are viewed as "invisible" symptoms, sometimes overlooked or ignored by health professionals. DL and CAY are in the process of writing a cognition handbook for MS clinics, summarising practical information to help the MS multidisciplinary team improve care for PwMS who have cognitive difficulties. We convened a stakeholder panel and offered a survey at a major MS professional education conference, to understand what content would be most helpful for our clinic handbook. The survey showed that health professionals think that cognition is not generally addressed well by clinics and that infrastructure and resources, education and information for both PwMS and professionals, and technologies to assess and treat cognition are all required to deliver better cognition services in MS clinics.

Interfacial Properties of Linear Alkane/Nitrogen Binary Mixtures: Molecular Dynamics Vapor-Liquid Equilibrium Simulations.

Molecular dynamics simulations were used to investigate the vapor-liquid equilibria (VLE) and interfacial properties of binary mixtures of N2 with either ethane, propane, n-decane, or n-dodecane. Alkanes and N2 were modeled by using the TraPPE-UA and Rivera force fields, respectively. The typically used Lorentz-Berthelot combining rules resulted in liquid phases that are too N2-rich compared to experiment. To improve the accuracy of VLE predictions, the hydrocarbon-nitrogen interactions were fine-tuned, and these improved parameters were used to investigate interfacial properties. Scaling the interaction strength between nitrogen and -CH3 and -CH2- groups by factors of 0.95 and 0.85, respectively, relative to the Lorentz-Berthelot value, was found to minimize error in pressure-composition phase diagrams. These scaling parameters gave excellent agreement with experimental phase diagrams for mixtures of N2 with ethane, propane, or n-dodecane over a range of state points. For ethane/N2 and n-decane/N2 mixtures, trends in surface tension as a function of temperature and pressure are correctly reproduced, although the simulated values are slightly too high compared to experimental values. To assess how the accuracy of hydrocarbon-N2 interaction strength impacts interfacial property predictions, we have compared density profiles and surface tension using several different scaling factors. Using the Lorentz-Berthelot combining rules rather than optimized parameters gave the same qualitative trends, although some quantitative results, such as liquid-phase N2 mole fraction, were found to differ by a factor of ∼1.5. Using the optimized interaction parameters, interfacial behavior was examined by calculating density and free energy profiles. Nitrogen molecules preferentially adsorb at the interfacial region between the liquid and vapor phases. This interfacial adsorption becomes less energetically favorable as either the temperature, pressure, or length of the alkane chain increases.

US county-level estimation for maternal and infant health-related behavior indicators using pregnancy risk assessment monitoring system data, 2016-2018.

BACKGROUND: There is a critical need for maternal and child health data at the local level (for example, county), yet most counties lack sustainable resources or capabilities to collect local-level data. In such case, model-based small area estimation (SAE) could be a feasible approach. SAE for maternal or infant health-related behaviors at small areas has never been conducted or evaluated. METHODS: We applied multilevel regression with post-stratification approach to produce county-level estimates using Pregnancy Risk Assessment Monitoring System (PRAMS) data, 2016-2018 (n = 65,803 from 23 states) for 2 key outcomes, breastfeeding at 8 weeks and infant non-supine sleeping position. RESULTS: Among the 1,471 counties, the median model estimate of breastfeeding at 8 weeks was 59.8% (ranged from 34.9 to 87.4%), and the median of infant non-supine sleeping position was 16.6% (ranged from 10.3 to 39.0%). Strong correlations were found between model estimates and direct estimates for both indicators at the state level. Model estimates for both indicators were close to direct estimates in magnitude for Philadelphia County, Pennsylvania. CONCLUSION: Our findings support this approach being potentially applied to other maternal and infant health and behavioral indicators in PRAMS to facilitate public health decision-making at the local level.

In-Vitro Cell-Induced Corrosion by Macrophages on Cobalt-Chromium-Molybdenum Alloy.

BACKGROUND: Patients have received cobalt-chromium-molybdenum (CoCrMo) implants for their joint replacement for decades. There have been reports of inflammatory cell-induced corrosion (ICIC) of these implants from retrieval studies. The goal of this study is to see if we could recreate ICIC in vitro and whether electrocautery damage to alloy surfaces may hasten this process. METHODS: Murine macrophages were cultured on CoCr disks with and without damage from a monopolar electrocautery. Culture medium was replaced every 12 hours and supernatant was collected every 4 days. After 30 days, cells were removed, counted, and digested. The metal concentrations in the supernatant and within cells were assessed using inductively coupled plasma spectrometry for comparison. RESULTS: The Co supernatant concentration was higher in the undamaged disks with activated macrophages. Higher concentrations of Co and Mo were found in the supernatant of the undamaged disks vs the electrocautery (EC) corrosion damaged disks. There was a significantly higher intracellular Co and Mo concentration with activated cells on CoCrMo disks vs the control group and no difference compared to EC damaged disk group. Scanning electron microscopy displayed microscopic pitting on the surfaces exposed to macrophages without EC damage. CONCLUSION: We found that macrophages could reproduce findings of ICIC pits on the surface of CoCrMo alloy and that the addition of EC damage to the surface did not increase the process. The clinical significance of these findings should be further investigated to determine if this could explain a small number of poor total knee arthroplasty reported outcomes.

Disaster Preparedness Among Women With a Recent Live Birth in Hawaii - Results From the Pregnancy Risk Assessment Monitoring System (PRAMS), 2016.

OBJECTIVE: The aim of this study was to examine emergency preparedness behaviors among women with a recent live birth in Hawaii. METHODS: Using the 2016 Hawaii Pregnancy Risk Assessment Monitoring System, we estimated weighted prevalence of 8 preparedness behaviors. RESULTS: Among 1010 respondents (weighted response rate, 56.3%), 79.3% reported at least 1 preparedness behavior, and 11.2% performed all 8 behaviors. The prevalence of women with a recent live birth in Hawaii reporting preparedness behaviors includes: 63.0% (95% CI: 58.7-67.1%) having enough supplies at home for at least 7 days, 41.3% (95% CI: 37.1-45.6%) having an evacuation plan for their child(ren), 38.7% (95% CI: 34.5-43.0%) having methods to keep in touch, 37.8% (95% CI: 33.7-42.1%) having an emergency meeting place, 36.6% (95% CI: 32.6-40.9%) having an evacuation plan to leave home, 34.9% (95% CI: 30.9-39.2%) having emergency supplies to take with them if they have to leave quickly, 31.8% (95% CI: 27.9-36.0%) having copies of important documents, and 31.6% (95% CI: 27.7-35.8%) having practiced what to do during a disaster. CONCLUSIONS: One in 10 women practiced all 8 behaviors, indicating more awareness efforts are needed among this population in Hawaii. The impact of preparedness interventions implemented in Hawaii can be tracked with this question over time.

Opioid use during pregnancy: An analysis of comment data from the 2016 Pregnancy Risk Assessment Monitoring System survey.

ABTSTRACTBackground: Opioid misuse during pregnancy has been associated with adverse infant outcomes including preterm birth, stillbirth, and neonatal opioid withdrawal syndrome. The Pregnancy Risk Assessment Monitoring System (PRAMS) is an on-going state-based surveillance system of maternal behaviors, attitudes, and experiences prior to, during, and after pregnancy. Methods: We analyzed qualitative comments related to opioid use during pregnancy collected in 2016 from an open-ended prompt at the end of the PRAMS survey in 35 states (N = 40,408). Key word searches were conducted on the open-ended responses (n = 9,549) to identify opioid-related content with an automated function using Microsoft Excel. All responses from the initial screening (n = 1,035) were manually reviewed, and 69 responses were confirmed to relate to the respondent's personal experience with opioid use during pregnancy. Content analysis was conducted by 3 independent coders; key themes were compiled, discussed, and finalized by the coding team. Results: Five key themes related to opioid use during pregnancy were identified: (1) gratitude for treatment, recovery, and healthy infants; (2) pregnancy as motivation to seek treatment; (3) difficulty finding prenatal care providers with training in substance use disorders; (4) concern about the effects of treatment on the infant; and (5) experiences of discrimination and stigma in the hospital around the time of delivery. Conclusions: Women may be aware of the potential impact of opioid use during pregnancy on the health of their infants and motivated to seek treatment. Findings may help inform new and ongoing initiatives designed to improve care and reduce stigma for women needing or seeking treatment.