Tale Of A Non-Interacting Additive In A Lithium-Ion Electrolyte: Effect On Ionic Speciation And Electrochemical Properties

New lithium electrolytes compatible with high energy density cells are critical for lithium metal battery applications, but dendrite formation associated with the use of dilute organic electrolytes complicates their realization. High-concentration electrolytes mitigate some of the issues of the electrolytes but introduce additional problems, such as low conductivity and high cost. Hence, pseudo-concentrated electrolytes, wherein a co-solvent is added to a dilute electrolyte, have been presented as a possible alternative to both dilute and concentrated electrolytes. However, the effect that the co-solvent has on the electrolyte properties at both macroscopic and microscopic levels is unknown. Here, a study of the structure and electrochemical properties of two electrolytes as a function of co-solvent concentration is presented using an array of spectroscopies (FTIR, ATR-FTIR, and nuclear magnetic resonance) and computational methods (density functional theory calculations). The chosen electrolytes comprised two different lithium salts (LiPF6 and LiTFSI) in a mixture of dimethyl carbonate (DMC) with 1,1,1,3,3-pentafluorobutane (PFB) as the co-solvent. Our results show that in the case of the LiPF6/DMC electrolyte, the addition of a co-solvent (PFB) with a larger dielectric constant results in the strengthening of the lithium-anion interaction and the formation of aggregate species since PFB does not interact with the anion. Conversely, in the LiTFSI/DMC electrolyte, the co-solvent appears to interact with the anion via hydrogen bonds, which leads to the dissociation of contact ion pairs. The change in ionic speciation of the electrolytes upon addition of PFB provides a reasonable framework to explain the different trends in both the bulk and interfacial macroscopic properties, such as conductivity, viscosity, and electrochemical stability. Overall, our findings demonstrate that the interactions between the anion and the co-solvent must be taken into consideration when adding a co-solvent because they play a major role in determining the final electrolyte properties

The Effects of Grazing Cover Crops on Animal Performance and Soybean Production

Grazing cover crops has the potential to offset costs incurred with cover crop establishment, thus incentivizing management adoption. Information regarding cover crop species in combination with grazing and their subsequent effects on soybean production is limited. A field trial was conducted in Newton, MS from 2019 to 2021 to assess these effects. Cover crop treatments included oats (O), O + crimson clover (OC), and OC + radish (OCR) were applied in a randomized complete block design with three replications. Cover crops differed in nutritive analysis; O had significantly lower mean CP, but greater total daily nutrients (TDN). Weaned beef steers grazing cover crops had lower ADG in the OCR treatment (3.03 lb hd-1 d-1), compared to O (3.52 lb hd-1 d-1) and OC (3.55 lb hd-1 d-1). No significant difference was observed in soybean grain yield between cover crop treatments. Mean yields were 51.1, 46.1, and 38.7 bu ac-1 for the O, OC, and OCR treatments, respectively. Total net returns for grazing plus soybean production were significantly lower in the OCR ($817.51 ac-1), compared to the O ($1,107.03 ac-1) and OC ($1,071.15 ac-1) treatments. These returns suggest that grazing provides an added value to cover crop establishment and provides incentives for increased revenue for producers willing to combine livestock and row crop enterprises

Chemical and Thermal Analysis

Work has included significant research in several areas aimed at further clarification of the aging and chemical failure mechanism of thermoplastics (PVDF or Tefzel) for pipes. Among the areas investigated were the crystallinity changes associated with both the Coflon and Tefzel after various simulated environmental exposures using X-Ray diffraction analysis. We have found that significant changes in polymer crystallinity levels occur as a function of the exposures. These crystallinity changes may have important consequences on the fracture, fatigue, tensile, and chemical resistance of the materials. We have also noted changes in the molecular weight distribution of the Coflon material using a dual detector Gel Permeation Analysis. Again these changes may result in variation in the mechanical and chemical properties in the material. We conducted numerous analytical studies with methods including X-Ray Diffraction, Gel Permeation Chromatography, Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis, and Differential Scanning Calorimetry. We investigated a number of aged samples of both Tefzel and Coflon that were forwarded from MERL. Pressurized tests were performed in a modified Fluid G, which we will call G2. In this case the ethylene diamine concentration was increased to 3 percent in methanol. Coflon pipe sections and powdered Coflon were exposed in pressure cells at 1700 psi at three separate test temperatures, 70 C, 110 C, and 130 C. The primary purpose of the pressure tests in Fluid G2 was to further elucidate the aging mechanism of PVDF degradation

Healthy & Empowered Youth: A Positive Youth Development Program for Native Youth

Introduction: During 2010–2012, Oregon Health & Science University’s Prevention Research Center, a Northwest Tribe, and the Northwest Portland Area Indian Health Board, collaborated to evaluate the Healthy & Empowered Youth Project, a school- and community-based positive youth development program for American Indian and Alaska Native high school students. Methods: The Native STAND (Students Together Against Negative Decisions) curriculum was enhanced with hands-on learning activities in media design to engage students in sexual and reproductive health topics covered by the curriculum. Guest speakers, field trips, and extracurricular activities were added to provide academic enrichment, engage students in cultural activities, and offer opportunities for career development. Students completed comprehensive pre- and postsurveys, and the authors conducted focus groups and key informant interviews with students and teachers. Data analysis was conducted during 2013–2014. Results: Survey findings demonstrated improvements in student leadership and achievement, physical and mental health, and protective sexual health behaviors. The percentage of female teens reporting use of a condom the last time they had sex increased from 17% to 30%, and those who reported ever having been tested for sexually transmitted illnesses doubled from 12% to 24%. Focus group and interview findings indicated similar improvements in student self-esteem, life skills, health behavior, and engagement in community. Conclusions: The Healthy & Empowered Youth Project educated and empowered Native high school students on a variety of sensitive health topics. The media enhancements were central to the program’s success, reinforcing and personalizing classroom lessons and generating health-related videos and posters that resonated with family and friends

Possible new Arkansas endemic plant revealed by DNA sequence analysis, A

Cardamine angustata var. ouachitana, a wildflower in the mustard family (Brassicaceae), was described by Smith in 1982 to include a form of Cardamine found only in the Ouachita Mountains of Arkansas. This variety is morphologically very similar to typical Cardamine angustata. The major difference noted by Smith for the two varieties was the complete lack of leaf hairs (trichomes) in the new variety, whereas typical Cardamine angustata normally possesses trichomes. However, Al-Shehbaz rejected the variety ouachitana and reduced it to synonymy with the typical C. angustata. The recommendation of Al-Shehbaz has been followed and the taxon Cardamine angustata var. ouachitana is currently not accepted by most plant taxonomists. We performed a preliminary evaluation of the status of Cardamine angustata var. ouachitana by comparing ribosomal internal transcribed spacer region DNA sequences from specimens of Cardamine angustata var. ouachitana with sequences of Cardamine angustata from the main range of the species and other related species of Cardamine. Phylogenetic analyses of these data produced an unexpected result; specimens of C. angustata var. ouachitana were actually closely related to C. concatenata, rather than the expected close relationship with C. angustata. However, C. angustata var. ouachitana is morphologically distinct from C. concatenata. These results suggest that Cardamine angustata var. ouachitana is actually a new species found only in the Ouachita Mountains of Arkansas

Favorable Climate Change Response Explains Non-Native Species' Success in Thoreau's Woods

Invasive species have tremendous detrimental ecological and economic impacts. Climate change may exacerbate species invasions across communities if non-native species are better able to respond to climate changes than native species. Recent evidence indicates that species that respond to climate change by adjusting their phenology (i.e., the timing of seasonal activities, such as flowering) have historically increased in abundance. The extent to which non-native species success is similarly linked to a favorable climate change response, however, remains untested. We analyzed a dataset initiated by the conservationist Henry David Thoreau that documents the long-term phenological response of native and non-native plant species over the last 150 years from Concord, Massachusetts (USA). Our results demonstrate that non-native species, and invasive species in particular, have been far better able to respond to recent climate change by adjusting their flowering time. This demonstrates that climate change has likely played, and may continue to play, an important role in facilitating non-native species naturalization and invasion at the community level

Transcriptome-Guided Functional Analyses Reveal Novel Biological Properties and Regulatory Hierarchy of Human Embryonic Stem Cell-Derived Ventricular Cardiomyocytes Crucial for Maturation

Human (h) embryonic stem cells (ESC) represent an unlimited source of cardiomyocytes (CMs); however, these differentiated cells are immature. Thus far, gene profiling studies have been performed with non-purified or non-chamber specific CMs. Here we took a combinatorial approach of using systems biology to guide functional discoveries of novel biological properties of purified hESC-derived ventricular (V) CMs. We profiled the transcriptomes of hESCs, hESC-, fetal (hF) and adult (hA) VCMs, and showed that hESC-VCMs displayed a unique transcriptomic signature. Not only did a detailed comparison between hESC-VCMs and hF-VCMs confirm known expression changes in metabolic and contractile genes, it further revealed novel differences in genes associated with reactive oxygen species (ROS) metabolism, migration and cell cycle, as well as potassium and calcium ion transport. Following these guides, we functionally confirmed that hESC-VCMs expressed IKATP with immature properties, and were accordingly vulnerable to hypoxia/reoxygenation-induced apoptosis. For mechanistic insights, our coexpression and promoter analyses uncovered a novel transcriptional hierarchy involving select transcription factors (GATA4, HAND1, NKX2.5, PPARGC1A and TCF8), and genes involved in contraction, calcium homeostasis and metabolism. These data highlight novel expression and functional differences between hESC-VCMs and their fetal counterparts, and offer insights into the underlying cell developmental state. These findings may lead to mechanism-based methods for in vitro driven maturation. © 2013 Poon et al.published_or_final_versio

Validation of a score tool for measurement of histological severity in juvenile dermatomyositis and association with clinical severity of disease.

OBJECTIVES: To study muscle biopsy tissue from patients with juvenile dermatomyositis (JDM) in order to test the reliability of a score tool designed to quantify the severity of histological abnormalities when applied to biceps humeri in addition to quadriceps femoris. Additionally, to evaluate whether elements of the tool correlate with clinical measures of disease severity. METHODS: 55 patients with JDM with muscle biopsy tissue and clinical data available were included. Biopsy samples (33 quadriceps, 22 biceps) were prepared and stained using standardised protocols. A Latin square design was used by the International Juvenile Dermatomyositis Biopsy Consensus Group to score cases using our previously published score tool. Reliability was assessed by intraclass correlation coefficient (ICC) and scorer agreement (α) by assessing variation in scorers' ratings. Scores from the most reliable tool items correlated with clinical measures of disease activity at the time of biopsy. RESULTS: Inter- and intraobserver agreement was good or high for many tool items, including overall assessment of severity using a Visual Analogue Scale. The tool functioned equally well on biceps and quadriceps samples. A modified tool using the most reliable score items showed good correlation with measures of disease activity. CONCLUSIONS: The JDM biopsy score tool has high inter- and intraobserver agreement and can be used on both biceps and quadriceps muscle tissue. Importantly, the modified tool correlates well with clinical measures of disease activity. We propose that standardised assessment of muscle biopsy tissue should be considered in diagnostic investigation and clinical trials in JDM