Cellular mechanotransduction of human osteoblasts in microgravity.

Astronauts experience significant and rapid bone loss as a result of an extended stay in space, making the International Space Station (ISS) the perfect laboratory for studying osteoporosis due to the accelerated nature of bone loss on the ISS. This prompts the question, how does the lack of load due to zero-gravity propagate to bone-forming cells, human fetal osteoblasts (hFOBs), altering their maturation to mineralization? Here, we aim to study the mechanotransduction mechanisms by which bone loss occurs in microgravity. Two automated experiments, 4 microfluidic chips capable of measuring single-cell mechanics of hFOBs via aspiration and cell spheroids incubated in pressure-controlled chambers, were each integrated into a CubeLab deployed to the ISS National Laboratory. For the first experiment, we report protrusion measurements of aspirated cells after exposure to microgravity at the ISS and compare these results to ground control conducted inside the CubeLab. Our analysis revealed slightly elongated protrusions for space samples compared to ground samples indicating softening of hFOB cells in microgravity. In the second experiment, we encapsulated osteoblast spheroids in collagen gel and incubated the samples in pressure-controlled chambers. We found that microgravity significantly reduced filamentous actin levels in the hFOB spheroids. When subjected to pressure, the spheroids exhibited increased pSMAD1/5/9 expression, regardless of the microgravity condition. Moreover, microgravity reduced YAP expression, while pressure increased YAP levels, thus restoring YAP expression for spheroids in microgravity. Our study provides insights into the influence of microgravity on the mechanical properties of bone cells and the impact of compressive pressure on cell behavior and signaling in space.

Cellular mechanotransduction of human osteoblasts in microgravity.

Astronauts experience significant and rapid bone loss as a result of an extended stay in space, making the International Space Station (ISS) the perfect laboratory for studying osteoporosis due to the accelerated nature of bone loss on the ISS. This prompts the question, how does the lack of load due to zero-gravity propagate to bone-forming cells, human fetal osteoblasts (hFOBs), altering their maturation to mineralization? Here, we aim to study the mechanotransduction mechanisms by which bone loss occurs in microgravity. Two automated experiments, microfluidic chips capable of measuring single-cell mechanics via aspiration and cell spheroids incubated in pressure-controlled chambers, were each integrated into a CubeLab deployed to the ISS National Laboratory. For the first experiment, we report protrusion measurements of aspirated cells after exposure to microgravity at the ISS and compare these results to ground control conducted inside the CubeLab. We found slightly elongated protrusions for space samples compared to ground samples indicating softening of hFOB cells in microgravity. In the second experiment, we encapsulated osteoblast spheroids in collagen gel and incubated the samples in pressure-controlled chambers. We found that microgravity significantly reduced filamentous actin levels in the hFOB spheroids. When subjected to pressure, the spheroids exhibited increased pSMAD1/5/9 expression, regardless of the microgravity condition. Moreover, microgravity reduced YAP expression, while pressure increased YAP levels, thus restoring YAP expression for spheroids in microgravity. Our study provides insights into the influence of microgravity on the mechanical properties of bone cells and the impact of compressive pressure on cell signaling in space.

Bubble nucleation and growth on microstructured surfaces under microgravity.

Understanding the dynamics of surface bubble formation and growth on heated surfaces holds significant implications for diverse modern technologies. While such investigations are traditionally confined to terrestrial conditions, the expansion of space exploration and economy necessitates insights into thermal bubble phenomena in microgravity. In this work, we conduct experiments in the International Space Station to study surface bubble nucleation and growth in a microgravity environment and compare the results to those on Earth. Our findings reveal significantly accelerated bubble nucleation and growth rates, outpacing the terrestrial rates by up to ~30 times. Our thermofluidic simulations confirm the role of gravity-induced thermal convective flow, which dissipates heat from the substrate surface and thus influences bubble nucleation. In microgravity, the influence of thermal convective flow diminishes, resulting in localized heat at the substrate surface, which leads to faster temperature rise. This unique condition enables quicker bubble nucleation and growth. Moreover, we highlight the influence of surface microstructure geometries on bubble nucleation. Acting as heat-transfer fins, the geometries of the microstructures influence heat transfer from the substrate to the water. Finer microstructures, which have larger specific surface areas, enhance surface-to-liquid heat transfer and thus reduce the rate of surface temperature rise, leading to slower bubble nucleation. Our experimental and simulation results provide insights into thermal bubble dynamics in microgravity, which may help design thermal management solutions and develop bubble-based sensing technologies.

Non-adherence to Labeling Standards Can Misrepresent Safety of Ingredients in Cosmetic Cleansers.

US Labeling requirements for cosmetic products are established by the US Food and Drug Administration (USFDA) and detailed in the Code of Federal Regulations (21 CFR 701.3).1 Over 16,000 cosmetic ingredients names have been documented and ingredient nomenclature resources are recommended by the USFDA for use by manufacturers and suppliers.

Application of the Indigenous evaluation framework to a university certificate program for building cultural awareness in science, technology, engineering, and mathematics.

This paper presents a case example of the Indigenous Evaluation Framework as applied to a science, technology, engineering, and mathematics (STEM) education pilot program. Indigenous methodologies include knowledge and data that are inclusive of historically marginalized groups, are highly meaningful, valid, and useful for all. A paradigm shift from Western evaluation methodologies to Indigenous evaluation is necessary when evaluating STEM programs that are committed to increasing recruitment, retention, and graduation of students from historically marginalized groups. This paper describes the use of the Indigenous Evaluation Framework during the first two years of the newly created Environmental Stewardship of Indigenous Lands program at the University of Colorado Denver. We discuss the importance of the Indigenous Evaluation Framework and how it informs the development and continued improvements to the program that also provides agency to program leads and participants.

Predicting nonpoint stormwater runoff quality from land use.

Evaluating the impact of urban development on natural ecosystem processes has become an increasingly complex task for planners, environmental scientists, and engineers. As the built environment continues to grow, unregulated nonpoint pollutants from increased human activity and large-scale development severely stress urban streams and lakes resulting in their currently impaired or degraded state. In response, integrated water quality management programs have been adopted to address these unregulated nonpoint pollutants by utilizing best management practices (BMPs) that treat runoff as close to the source as possible. Knowing where to install effective BMPs is no trivial task, considering budget constraints and the spatially extensive nature of nonpoint stormwater runoff. Accordingly, this paper presents an initial, straightforward and cost-effective methodology to identify critical nonpoint pollutant source watersheds through correlation of water quality with land use. Through an illustrative application to metropolitan Denver, Colorado, it is shown how this method can be used to aid stormwater professionals to evaluate and specify retrofit locations in need of water quality treatment features reduce, capture and treat stormwater runoff prior to entering receiving waters.

Hard water softening effect of a baby cleanser.

BACKGROUND: Hard water is associated with atopic dermatitis (eczema). We wanted to determine if a baby cleanser and its individual components altered free ionized calcium (Ca2+) in a simulated hard water baby bath. For these studies, an in vitro determination of free Ca2+ in a simulated hard water baby bath, and an in vivo exploratory study of free Ca2+ absorption into skin from hard water were performed. METHODS: Free Ca2+ was measured with an ion-sensitive electrode in vitro in hard water (100-500 ppm, Ca2+) before and after addition of the cleanser and/or its components. In an exploratory study, absorption of Ca2+ into skin from hard water was determined in three female participants (aged 21-29 years). RESULTS: At an in-use dilution of 1%, the test cleanser reduced free Ca2+ from ~500 ppm to <200 ppm; a 10% in-use dilution bound virtually all free Ca2+. The anionic surfactant component contributed the most to this effect. In the exploratory in vivo study, we measured a reduction of ~15% in free Ca2+ from simulated hard water over 10 minutes. CONCLUSION: Baby cleansers can bind free Ca2+ and reduce the effective water hardness of bath water. Reducing the amount of free Ca2+ in the water will reduce the availability of the ion for binding to the skin. Altering or reducing free Ca2+ concentrations in bath water may be an important parameter in creating the ideal baby bath.

Measurement of colloidal phenomena during flow through refractive index matched porous media.

Colloidal phenomena in porous media, natural or engineered, are important in a breadth of science and technology applications, but fundamental understanding is hampered by the difficulty in measuring colloid deposit morphology in situ. To partially address this need, this paper describes a static light scattering apparatus using a flow cell filled with refractive index matched (RIM) porous media, allowing real-time measurement of colloidal phenomena as a function of depth within the flow cell. A laser interacts with the colloids in the pore space and their structures, but not with the RIM media. The intensity of scattered light is measured as a function of scattering angle, which allows characterization of colloid deposit morphology as a fractal dimension and a radius of gyration. In parallel, fluid discharge rate and pressure drop are recorded to determine permeability, a key parameter for any application involving flow through porous media. This apparatus should prove useful in any application requiring characterization of colloidal phenomena within porous media. Additionally, this paper describes how to use granular Nafion as RIM porous media.

Colloid Deposit Morphology and Clogging in Porous Media: Fundamental Insights Through Investigation of Deposit Fractal Dimension.

Experiments reveal a wide discrepancy between the permeability of porous media containing colloid deposits and the available predictive equations. Evidence suggests that this discrepancy results, in part, from the predictive equations failing to account for colloid deposit morphology. This article reports a series of experiments using static light scattering (SLS) to characterize colloid deposit morphology within refractive index matched (RIM) porous media during flow through a column. Real time measurements of permeability, specific deposit, deposit fractal dimension, and deposit radius of gyration, at different vertical positions, were conducted with initially clean porous media at various ionic strengths and fluid velocities. Decreased permeability (i.e., increased clogging) corresponded with higher specific deposit, lower fractal dimension, and smaller radius of gyration. During deposition, fractal dimension, radius of gyration, and permeability decreased with increasing specific deposit. During flushing with colloid-free fluid, these trends reversed, with increased fractal dimension, radius of gyration, and permeability. These observations suggest a deposition scenario in which large and uniform aggregates become deposits, which reduce porosity, lead to higher fluid shear forces, which then decompose the deposits, filling the pore space with small and dendritic fragments of aggregate.

Human Cumulative Irritation Tests of Common Preservatives Used in Personal Care Products: A Retrospective Analysis of Over 45 000 Subjects.

The cumulative irritation test (CIT) is an accepted method used to evaluate the skin irritation potential and safety of individual ingredients and formulas of leave-on skin care and cosmetic compounds. Here, we report the results of CITs collected by JOHNSON & JOHNSON Consumer Companies, Inc. (Skillman, NJ), part of an extensive tiered program to evaluate product safety. In the CIT, test formulations were applied to the skin of adults (18-70 years) with no known skin disease or allergies, 3 times per week for 2 weeks using semi-occlusive clinical patches. Preservatives were 1 of up to 16 components of test formulas, and included ethylenediaminetetraacetic acid, diazolidinyl urea, 1,3-Bis(hydroxymethyl)-5,5-dimethylimidazolidine-2,4-dione, parabens, isothiazolinone, phenoxyethanol, sorbates, or benzoates. Skin sites were scored after each patch removal using a 5-point scale, with 0 = no visible reaction and 4 = erythema, marked edema, or substantial vesiculation. Scores were reported as percentage of maximal irritation score. Data were analyzed from 1363 CIT studies (over 45 000 subjects). There were no significant differences in percentage of maximal scores between formulas grouped by preservative types (p > .1). Median score across the entire dataset was 0.44, with most formulas showing none or mild irritation. Although seasonal variations were observed, no correlation was noted between score and preservative concentration. In conclusion, in a large, normal subject dataset, preservatives at typical in-use concentrations did not appear to contribute to skin irritation.

End-of-life care planning: improving documentation of advance directives in the outpatient clinic using electronic medical records.

BACKGROUND: The right to self-determination is fundamental in clinical ethics. End-of-life conversations and advance directives (ADs), in addition to preserving this right, have been shown to decrease the likelihood of in-hospital death, improve the quality of care, and lower health costs in the final week of life. Despite these benefits, the rates of AD documentation are poor. OBJECTIVE: Our aim was to assess the effectiveness of an electronic medical record (EMR)-based reminder in improving AD documentation rates. METHODS: We conducted a prospective quality improvement study in outpatients at the Grady Memorial Hospital Purple Pod Clinic in Atlanta, GA. Using the EMR system EPIC we set to implement a reminder system consisting of the addition of "Advanced Directives Counseling" to the problem list (ADPL) of 50% of outpatients meeting one of the following criteria: age >65 years, congestive heart failure (CHF), chronic obstructive pulmonary disease (COPD), acquired immune deficiency syndrome (AIDS), malignancy, cirrhosis, end-stage renal disease (ESRD), or stroke. Primary care physicians were encouraged to document ADs for all patients. The number of patients with documented ADs was assessed at 6 months post-test of change. RESULTS: A total of 588 patient charts were screened by seven providers, with 157 patients meeting the predefined criteria for AD documentation. During a 6-month period, 64 patients were seen in the clinic; 38 had AD on their problem list, and 26 did not. Seventy-six percent of charts with ADPL had documentation of an AD. Only 11.5% of those without ADPL had an AD documented. CONCLUSIONS: EMR-based reminders are effective in improving documentation rates of ADs. Further research is needed to establish whether improved documentation impacts inpatient management and costs of care.

40 years of topical tretinoin use in review.

Topical tretinoin has been approved for use in dermatology for 40 years and is currently approved for the treatment of acne vulgaris and photodamage. During this time, topical tretinoin has accumulated significant efficacy and safety data in the treatment of acne and photodamaged skin and demonstrated clinical potential for treating a range of other dermatologic conditions. The diverse effects may be due to complex underlying mechanisms of action associated with tretinoin, including keratolytic activity, collagenesis, and other mechanisms associated with the activation of nuclear retinoic acid receptors (RARα, RARß, and RARγ). In this article, we review the history of topical tretinoin use to date and outline emerging research suggesting that topical tretinoin may have potential clinical use for treating a multitude of other dermatological conditions when used either as monotherapy or in combination with other agents. We also describe newer formulations of topical tretinoin that have been designed to reduce irritation potential. In light of the substantial history of safety and efficacy of topical tretinoin in acne and photodamage, we speculate that it holds promise in treating many additional dermatological conditions, which may be explored in future research.

Zinc leaching from tire crumb rubber.

Because tires contain approximately 1-2% zinc by weight, zinc leaching is an environmental concern associated with civil engineering applications of tire crumb rubber. An assessment of zinc leaching data from 14 studies in the published literature indicates that increasing zinc leaching is associated with lower pH and longer leaching times, but the data display a wide range of zinc concentrations, and do not address the effect of crumb rubber size or the dynamics of zinc leaching during flow through porous crumb rubber. The present study was undertaken to investigate the effect of crumb rubber size using the synthetic precipitation leaching procedure (SPLP), the effect of exposure time using quiescent batch leaching tests, and the dynamics of zinc leaching using column tests. Results indicate that zinc leaching from tire crumb rubber increases with smaller crumb rubber and longer exposure time. Results from SPLP and quiescent batch leaching tests are interpreted with a single-parameter leaching model that predicts a constant rate of zinc leaching up to 96 h. Breakthrough curves from column tests displayed an initial pulse of elevated zinc concentration (~3 mg/L) before settling down to a steady-state value (~0.2 mg/L), and were modeled with the software package HYDRUS-1D. Washing crumb rubber reduces this initial pulse but does not change the steady-state value. No leaching experiment significantly reduced the reservoir of zinc in the crumb rubber.

Static light scattering resolves colloid structure in index-matched porous media.

Colloidal phenomena play an important role in natural porous media, where they influence soil structuring, contaminant migration, filtration, and clogging. Several methods are available to measure pore space geometry within porous media, but these methods have limited applicability when the relevant physical, chemical, or biological processes are dominated by dynamic colloidal phenomena. Here we report a new technique to quantify colloid aggregate structure as a fractal dimension using static light scattering within index-matched porous media (granular Nafion). We validate the method by obtaining consistent results for scattering in suspensions and in porous media, and verify that multiple scattering at environmentally relevant colloid concentrations does not affect the determination of fractal dimension. We also observe restructuring of aggregates during homogenization in the porous media, indicated by an apparent increase in fractal dimension, which can be explained by an analysis of the fluid shear stress caused by repeated inversions of test tubes either containing or not containing granular media. This technique will permit progress in obtaining fundamental descriptions of colloidal phenomena in porous media.

Use of topical tretinoin and the development of noncutaneous adverse events: evidence from a systematic review of the literature.

BACKGROUND: Topical retinoids have been in clinical use for the treatment of chronic skin conditions, including acne, photodamage, and psoriasis, for 30 years. OBJECTIVE: A systematic literature review was conducted to assess the incidence of noncutaneous adverse events (AE) among patients treated with topical retinoids with a focus on topical tretinoin studies reported before the Veterans Affairs Topical Tretinoin Chemoprevention trial. METHODS: Electronic literature searches were conducted in Embase and MEDLINE for literature reporting development of nonteratogenic, noncutaneous AE among patients treated with topical retinoids published through September 2008. RESULTS: The search yielded 2778 citations, of which 20 studies met inclusion criteria. Tretinoin was used in 14 of the studies. Other retinoids assessed included isotretinoin, adapalene, alitretinoin, and tazarotene. Within patients receiving topical tretinoin, 27.9% reported the occurrence of at least one noncutaneous AE. The majority of noncutaneous AE were transient and judged not to be related to tretinoin treatment. LIMITATIONS: The conclusions of this study apply largely to tretinoin compared with other topical retinoids. Many of the included trials were designed to evaluate the efficacy of topical treatment and reporting of safety events concentrated on incidence of localized AE, rather than systemic or noncutaneous events. CONCLUSION: We found no clear evidence of a relationship between the use of topical tretinoin and the development of noncutaneous AE before a recent report of excess mortality in a clinical trial. The majority of noncutaneous AE reported by patients receiving topical retinoids consisted of nonsevere, nonspecific symptoms that were judged not to be related to treatment.

Nitrogen and phosphorus transport in runoff from compost berms on a simulated military training landscape.

Compost mulches have potential to significantly offset on- and off-site environmental impacts resulting from mechanical soil disturbances and training manoeuvres on military training ranges. N and P transport was investigated in runoff from compost mulch berms made from various organic waste materials in combination with each other and with soil on a simulated military training landscape in north Alabama in 2007 and 2008. Berms were constructed using composted municipal yard waste (YW), wood chips (WC), pine bark fines (PB), and soil (SL) mixed in eight different proportions. Berms made from 100% soil which had a cumulative runoff PO(4)-P content of 12 mg L(-1) posed the greatest threat of negatively impacting the environment from inorganic P transport. Using compost mulch material with 40% soil to build berms reduced the potential for yard waste and wood chips to cause off-site negative environmental impacts from total dissolved solids, N, and P transport. Berms made from 100% pine bark fines which had cumulative runoff values of 760, 9, 22 and 5 mg L( -1), respectively, of TDS, NH(4)-N, NO(3)-N, and PO( 4)-P had the least potential to cause negative off-site environmental impact. To prevent negative impacts of nutrient transport in runoff from berms on training landscapes, the sites need to be well buffered to hydrologically isolate them from adjoining ecosystems.

Sports-specific factors, perceived peer drinking, and alcohol-related behaviors among adolescents participating in school-based sports in Southwest Georgia.

This study investigated the relationships among sports-specific factors, perceived peer drinking, and alcohol-related behaviors among adolescents, examining sex differences in the relationship between perceived peer drinking and alcohol-related behaviors. A questionnaire assessing demographics, sports-specific factors, perceived peer drinking, and alcohol-related behaviors was administered among 378 adolescents who were mostly male (76.3%) and non-Hispanic black (70.0%). Varsity sports participants reported higher levels of perceived peer drinking compared to those who participated in sports at other levels (B 0.64, 95% CI 0.28, 0.99, p<0.001). Participants in both sports offering team- and individual-level competition reported greater perceived peer drinking (B 0.71, 95% CI 0.05, 1.38, p=0.04), compared to those who only participated in individual sports. Perceived peer drinking was associated with alcohol-related behaviors (B 0.39, 95% CI 0.31, 0.47, p<0.001) and there were no significant differences between males and females in this relationship. Suggestions for future research include examining factors contributing to the low prevalence of drinking behaviors, and investigating factors related to sports that impact perceived peer drinking and alcohol-related behaviors.