Near Room Temperature Production of Segregated Network Composites of Carbon Nanotubes and Regolith as Multifunctional, Extra-Terrestrial Building Materials.

Constructing a semi-permanent base on the moon or Mars will require maximal use of materials found in situ and minimization of materials and equipment transported from Earth. This will mean a heavy reliance on regolith (Lunar or Marian soil) and water, supplemented by small quantities of additives fabricated on Earth. Here it is shown that SiO2-based powders, as well as Lunar and Martian regolith simulants, can be fabricated into building materials at near-ambient temperatures using only a few weight-percent of carbon nanotubes as a binder. These composites have compressive strength and toughness up to 100 MPa and 3 MPa respectively, higher than the best terrestrial concretes. They are electrically conductive (>20 S m-1) and display an extremely large piezoresistive response (gauge factor >600), allowing these composites to be used as internal sensors to monitor the structural health of extra-terrestrial buildings.

Knot Architecture for Biocompatible and Semiconducting 2D Electronic Fiber Transistors.

Wearable devices have generally been rigid due to their reliance on silicon-based technologies, while future wearables will utilize flexible components for example transistors within microprocessors to manage data. Two-dimensional (2D) semiconducting flakes have yet to be investigated in fiber transistors but can offer a route toward high-mobility, biocompatible, and flexible fiber-based devices. Here, the electrochemical exfoliation of semiconducting 2D flakes of tungsten diselenide (WSe2) and molybdenum disulfide (MoS2) is shown to achieve homogeneous coatings onto the surface of polyester fibers. The high aspect ratio (>100) of the flake yields aligned and conformal flake-to-flake junctions on polyester fibers enabling transistors with mobilities µ ≈1 cm2 V-1 s-1 and a current on/off ratio, Ion/Ioff ≈102-104. Furthermore, the cytotoxic effects of the MoS2 and WSe2 flakes with human keratinocyte cells are investigated and found to be biocompatible. As an additional step, a unique transistor 'knot' architecture is created by leveraging the fiber diameter to establish the length of the transistor channel, facilitating a route to scale down transistor channel dimensions (≈100 µm) and utilize it to make a MoS2 fiber transistor with a human hair that achieves mobilities as high as µ ≈15 cm2 V-1 s-1.

Exploring the Inclusion of Person-Centered Care Domains in Stroke Transitions of Care Interventions: A Scientific Statement From the American Heart Association.

BACKGROUND: Health care teams along the stroke recovery continuum have a responsibility to support care transitions and return to the community. Ideally, individualized care will consider patient and family preferences, best available evidence, and health care professional input. Person-centered care can improve patient-practitioner interactions through shared decision-making in which health professionals and institutions are sensitive to those for whom they provide care. However, it is unclear how the concepts of person-centered care have been described in reports of stroke transitional care interventions. METHODS: A secondary analysis of a systematic review and meta-analysis was undertaken. We retrieved all included articles (n=17) and evaluated the extent to which each intervention explicitly addressed 7 domains of person-centered care: alignment of care with patients' values, preferences, and needs; coordination of care; information and education; physical comfort; emotional support; family and friend involvement; and smooth transition and continuity of care. RESULTS: Most of the articles included some aspects of person-centeredness; we found that certain domains were not addressed in the descriptions of transitional care interventions, and no articles mentioned all 7 domains of person-centered care. We identified 3 implications for practice and research: (1) delineating person-centered care components when reporting interventions, (2) elucidating social and cultural factors relevant to the study sample and intervention, and (3) clearly describing the role of family and nonmedical support in the intervention. CONCLUSIONS: There is still room for greater consistency in the reporting of person-centeredness in stroke transitions of care interventions, despite a long-standing definition and conceptualization of person-centered care in academic and clinically focused literature.

Intersectional forms of racism and sexual minority stress are associated with alcohol use among Latinx sexual minority men with greater Hispanic/Latinx cultural orientation.

Background: Latinx sexual minorities with increased levels of acculturation report higher rates of alcohol use, and discrimination may impact this association. Yet, there is little research examining the concomitant impact of racism and sexual minority stress (i.e. intersectional discrimination) and the additive effect of acculturation on Latinx sexual minority men's risk for hazardous alcohol consumption.Objectives: This study investigated the role of perceived stressfulness of intersectional discrimination in the relation between acculturation (US cultural orientation/Hispanic cultural orientation) and alcohol use among Latinx sexual minority men.Methods: A structural equation model was utilized to test the indirect effect of discrimination between acculturation and alcohol use with a sample of 357 Latinx sexual minority men (Mage = 28.39) recruited via Amazon MTurk.Results: The indirect effect between the Hispanic cultural orientation to alcohol use through intersectional forms of discrimination was significant and positive (b = .19, SE = .03, p < .01). The indirect effect for the US cultural orientation to alcohol use through intersectional forms of discrimination was significant and negative (b = -.10, SE = .03, p < .01).Conclusion: Contrary to previous literature, Latinx sexual minority men with a higher Hispanic cultural orientation reported higher levels of intersectional forms of discrimination, which in turn was associated with increased alcohol use. Those with a higher US cultural orientation reported lower levels of intersectional forms of discrimination, which in turn was associated with decreased alcohol use. These findings may help identify mechanisms that exacerbate health disparities for Latinx sexual minority men.

High-Mobility Flexible Transistors with Low-Temperature Solution-Processed Tungsten Dichalcogenides.

The investigation of high-mobility two-dimensional (2D) flakes beyond molybdenum disulfide (MoS2) will be necessary to create a library of high-mobility solution-processed networks that conform to substrates and remain functional over thousands of bending cycles. Here we report electrochemical exfoliation of large-aspect-ratio (>100) semiconducting flakes of tungsten diselenide (WSe2) and tungsten disulfide (WS2) as well as MoS2 as a comparison. We use Langmuir-Schaefer coating to achieve highly aligned and conformal flake networks, with minimal mesoporosity (∼2-5%), at low processing temperatures (120 °C) and without acid treatments. This allows us to fabricate electrochemical transistors in ambient air, achieving average mobilities of µMoS2 ≈ 11 cm2 V-1 s-1, µWS2 ≈ 9 cm2 V-1 s-1, and µWSe2 ≈ 2 cm2 V-1 s-1 with a current on/off ratios of Ion/Ioff ≈ 2.6 × 103, 3.4 × 103, and 4.2 × 104 for MoS2, WS2, and WSe2, respectively. Moreover, our transistors display threshold voltages near ∼0.4 V with subthreshold slopes as low as 182 mV/dec, which are essential factors in maintaining power efficiency and represent a 1 order of magnitude improvement in the state of the art. Furthermore, the performance of our WSe2 transistors is maintained on polyethylene terephthalate (PET) even after 1000 bending cycles at 1% strain.

Solution processed, vertically stacked hetero-structured diodes based on liquid-exfoliated WS2 nanosheets: from electrode-limited to bulk-limited behavior.

Vertically stacked metal-semiconductor-metal heterostructures, based on liquid-processed nanomaterials, hold great potential for various printed electronic applications. Here we describe the fabrication of such devices by spray-coating semiconducting tungsten disulfide (WS2) nanosheets onto indium tin oxide (ITO) bottom electrodes, followed by spraying single-walled carbon nanotubes (SWNTs) as the top electrode. Depending on the formulation of the SWNTs ink, we could fabricate either Ohmic or Schottky contacts at the WS2/SWNTs interface. Using isopropanol-dispersed SWNTs led to Ohmic contacts and bulk-limited devices, characterized by out-of-plane conductivities of ∼10-4 S m-1. However, when aqueous SWNTs inks were used, rectification was observed, due to the formation of a doping-induced Schottky barrier at the WS2/SWNTs interface. For thin WS2 layers, such devices were characterized by a barrier height of ∼0.56 eV. However, increasing the WS2 film thickness led to increased series resistance, leading to a change-over from electrode-limited to bulk-limited behavior at a transition thickness of ∼2.6 µm. This work demonstrates that Ohmic/Schottky behavior is tunable and lays the foundation for fabricating large-area 2D nanosheet-based solution-deposited devices and stacks.

Complete Genome Sequence of Stenotrophomonas maltophilia Siphophage Silvanus.

Stenotrophomonas maltophilia is an opportunistic Gram-negative bacterium capable of causing respiratory infections. S. maltophilia siphophage Silvanus was isolated, and its 45,678-bp genome is not closely related to known phages based on whole-genome comparative genomics analysis. It is predicted to use cos-type packaging due to the similarity of its large terminase subunit to that of phage HK97.

Quantifying the Piezoresistive Mechanism in High-Performance Printed Graphene Strain Sensors.

Printed strain sensors will be important in applications such as wearable devices, which monitor breathing and heart function. Such sensors need to combine high sensitivity and low resistance with other factors such as cyclability, low hysteresis, and minimal frequency/strain-rate dependence. Although nanocomposite sensors can display a high gauge factor (G), they often perform poorly in the other areas. Recently, evidence has been growing that printed, polymer-free networks of nanoparticles, such as graphene nanosheets, display very good all-round sensing performance, although the details of the sensing mechanism are poorly understood. Here, we perform a detailed characterization of the thickness dependence of piezoresistive sensors based on printed networks of graphene nanosheets. We find both conductivity and gauge factor to display percolative behavior at low network thickness but bulk-like behavior for networks above ∼100 nm thick. We use percolation theory to derive an equation for gauge factor as a function of network thickness, which well-describes the observed thickness dependence, including the divergence in gauge factor as the percolation threshold is approached. Our analysis shows that the dominant contributor to the sensor performance is not the effect of strain on internanosheet junctions but the strain-induced modification of the network structure. Finally, we find these networks display excellent cyclability, hysteresis, and frequency/strain-rate dependence as well as gauge factors as high as 350.

A path model of racial/ethnic discrimination and cardiovascular disease risk factors among college students of color.

ObjectiveRacial/ethnic minorities experience disproportionately greater risk to cardiovascular diseases (CVDs). This study examined racial/ethnic discrimination-as a psychosocial stressor-in a path model and its associations with CVD health risk factors among undergraduate students of color (SoC). Participants: The sample included 404 SoC whose ages ranged from 18 to 54 (Mage = 21.82, SD = 5.26; 65% female) from a Hispanic Serving Institution in Southern California. Methods: Participants responded to measures assessing the following traditional and non-traditional CVD indicators: depression, anxiety, and body mass index (BMI). A path model was configured with paths corresponding from racial/ethnic discrimination to BMI, depression, and anxiety symptoms, controlling for gender and age. Results: After accounting for covariates, findings revealed greater levels of racial/ethnic discrimination was uniquely associated with greater BMI, depression, and anxiety symptoms. Conclusions: Findings demonstrate racial/ethnic discrimination is associated with CVD health risk factors among SoC. Data highlight the importance and magnitude of adverse psychosocial experiences on CVD health.

Additive Manufacturing of Ti3 C2 -MXene-Functionalized Conductive Polymer Hydrogels for Electromagnetic-Interference Shielding.

The ongoing miniaturization of devices and development of wireless and implantable technologies demand electromagnetic interference (EMI)-shielding materials with customizability. Additive manufacturing of conductive polymer hydrogels with favorable conductivity and biocompatibility can offer new opportunities for EMI-shielding applications. However, simultaneously achieving high conductivity, design freedom, and shape fidelity in 3D printing of conductive polymer hydrogels is still very challenging. Here, an aqueous Ti3 C2 -MXene-functionalized poly(3,4-ethylenedioxythiophene):polystyrene sulfonate ink is developed for extrusion printing to create 3D objects with arbitrary geometries, and a freeze-thawing protocol is proposed to transform the printed objects directly into highly conductive and robust hydrogels with high shape fidelity on both the macro- and microscale. The as-obtained hydrogel exhibits a high conductivity of 1525.8 S m-1 at water content up to 96.6 wt% and also satisfactory mechanical properties with flexibility, stretchability, and fatigue resistance. Furthermore, the use of the printed hydrogel for customizable EMI-shielding applications is demonstrated. The proposed easy-to-manufacture approach, along with the highlighted superior properties, expands the potential of conductive polymer hydrogels in future customizable applications and represents a real breakthrough from the current state of the art.

Centering race/ethnicity: Differences in traumatic brain injury inpatient rehabilitation outcomes.

BACKGROUND: Persons of color have a higher incidence of traumatic brain injury (TBI) and experience disparities in the quality and quantity of interventions received, discharge disposition, functional outcomes, and mortality rate post TBI. OBJECTIVE: To examine racial/ethnic differences in rehabilitation outcomes for patients with TBI. DESIGN: Multiyear (2005-2016) and retrospective cohort using secondary data analysis from inpatient rehabilitation facilities (IRFs) across the United States. SETTING: eRehabData participating IRFs throughout the United States. PATIENTS: Forty-one thousand eight hundred forty-seven adults with a diagnosis of TBI, admitted to U.S. eRehabData participating IRFs. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Inpatient rehabilitation functional outcomes and discharge disposition. RESULTS: Participants were 41,847 non-Hispanic Whites (NHWs), Hispanics, non-Hispanic Asians (NHAs), and non-Hispanic Blacks (NHBs) aged 18-107 years. NHWs were used as the reference group. NHBs had the longest length of stay (17.65 ± 14.96). At admission, NHB, Hispanic, and NHA races/ethnicities were significantly associated with 1-3 point lower motor, cognitive, and total Functional Independence Measure (FIM) scores. NHB race was significantly associated with less than 1-point lower cognitive, motor, and total efficiency FIM scores. At discharge, NHB race was significantly associated with 1-2 point lower motor, cognitive, and total FIM scores; Hispanics and NHA race were associated with less than 1-point lower cognitive FIM scores. Compared to NHWs, Hispanic ethnicity was associated with greater odds of a discharge to home (odds ratio = 1.16, 95% confidence interval = 1.06-1.27). CONCLUSION: Contrary to established literature on functionality differences 1 year post TBI, the current study found racial/ethnic differences in functional outcomes during inpatient rehabilitation. These findings suggest a need for cultural competence/sensitivity in the care of racial/ethnic persons and centering potential contributing factors for racial/ethnic differences in TBI rehabilitation outcomes.

Interprofessional Education Activities for Students in Physician Assistant, Clinical Psychology, and Athletic Training Programs Utilizing Aspects of Team-Based and Problem-Based Learning Practices.

Interprofessional education (IPE) allows two or more professionals to learn from one another through partnership to improve patient outcomes. Implementation of IPE varies within health profession programs and universities, requiring programs to develop IPE activities that adhere to specific learning objectives or accreditation standards. These activities were a preliminary investigation on the feasibility of IPE activities at an institution with no substantial IPE infrastructure. Students integrated aspects of team-based learning (TBL), problem-based learning (PBL), and didactic components into diverse simulated patient cases with health profession students to develop skills in interdisciplinary patient-centered care. Lessons learned and future directions are discussed.

Printable G-Putty for Frequency- and Rate-Independent, High-Performance Strain Sensors.

While nanocomposite electromechanical sensors are expected to display reasonable conductivity and high sensitivity, little consideration is given to eliminating hysteresis and strain rate/frequency dependence from their response. For example, while G-putty, a composite of graphene and polysiloxane, has very high electromechanical sensitivity, its extreme viscoelasticity renders it completely unsuitable for real sensors due to hysteretic and rate-/frequency-dependent effects. Here it is shown that G-putty can be converted to an ink and printed into patterned thin films on elastic substrates. A partial graphene-polymer phase segregation during printing increases the thin-film conductivity by ×106 compared to bulk, while the mechanical effects of the substrate largely suppress hysteresis and completely remove strain rate and frequency dependence. This allows the fabrication of practical, high-gauge-factor, wearable sensors for pulse measurements as well as patterned sensors for low-signal vibration sensing.

Complete Genome Sequence of Burkholderia cenocepacia Phage Mica.

Burkholderia cenocepacia is a multidrug-resistant Gram-negative pathogen known to colonize patients with chronic granulomatous disease and cystic fibrosis. Here, we describe Burkholderia phage Mica, which is predicted to be a lysogenic myophage based on the similarity of its structural proteins to Enterobacteria phage P2 and Burkholderia phage KL3.

A Simple Model Relating Gauge Factor to Filler Loading in Nanocomposite Strain Sensors.

Conductive nanocomposites are often piezoresistive, displaying significant changes in resistance upon deformation, making them ideal for use as strain and pressure sensors. Such composites typically consist of ductile polymers filled with conductive nanomaterials, such as graphene nanosheets or carbon nanotubes, and can display sensitivities, or gauge factors, which are much higher than those of traditional metal strain gauges. However, their development has been hampered by the absence of physical models that could be used to fit data or to optimize sensor performance. Here we develop a simple model which results in equations for nanocomposite gauge factors as a function of both filler volume fraction and composite conductivity. These equations can be used to fit experimental data, outputting figures of merit, or predict experimental data once certain physical parameters are known. We have found these equations to match experimental data, both measured here and extracted from the literature, extremely well. Importantly, the model shows the response of composite strain sensors to be more complex than previously thought and shows factors other than the effect of strain on the interparticle resistance to be performance limiting.

Macular microhole and foveal red spot syndrome: a critical review of the literature.

PURPOSE: The purpose of this article is to review the literature on nomenclature, natural history, clinical features, diagnosis, management, and prognosis of both macular microhole (MMH) and foveal red spot syndrome (FRS). METHODS: A PubMed primary literature search (February 1, 2020) utilizing the terms macular microhole, foveal red spot syndrome, and outer retinal hole was conducted. All chosen articles were case reports or case series. Articles qualified for inclusion if they documented symptoms, imaging findings, or followed patients longitudinally. RESULTS: A total of 14 studies from 1988 to 2019 that evaluated either MMH, FRS, or both were included in the review. No comparative study between the two defects was found. Studies often used the terms FRS and MMH interchangeably to reference both partial- and full-thickness lesions of the macula. Spectral-domain optical coherence tomography (SD-OCT) was most frequently able to identify these lesions and revealed an absence of all neural retinal layers from the inner limiting membrane (ILM) to the retinal pigment epithelium (RPE) in the full-thickness lesions while the partial-thickness lesions most often involved the photoreceptor layer (PRL) and less frequently the external limiting membrane (ELM). OCT revealed that vitreomacular traction (VMT) was involved in the natural history of both FRS and MMH for a significant subset of patients. CONCLUSION: The terms MMH and FRS have been used interchangeably in the literature. Advances in OCT have revealed that MMHs and FRSs are distinct but sometimes overlapping entities. We suggest that MMH and FRS are similar entities defined as one or more sharply defined lesions in the fovea of the eye < 150 µm in size. MMHs are a full-thickness defect of the entire neuroretina at the center of the foveola while FRSs are partial-thickness lesions. Current literature suggests that there may be subtle differences in the pathogenesis, clinical features, and diagnosis between MMH and FRS; however, prognosis and management for both are favorable. Lastly, we suggest that the terms outer lamellar macular microholes and full-thickness macular microholes may be the more appropriate terminologies to refer to FRS and MMH, respectively.

Neuroendocrine mechanisms of puberty in non-human primates.

An increase in pulsatile release of gonadotropin releasing hormone (GnRH) initiates puberty in mammalian species. While mutations in KISS1 and TAC3 and their receptors, KISS1R and NK3R, respectively, result in the absence or abnormal timing of puberty, the neurocircuitry and precise role of kisspeptin and neurokinin B (NKB) in regulation of the GnRH neurosecretory system in primate puberty remain elusive. This review discusses how kisspeptin and NKB signaling contributes to the pubertal increase in GnRH release in non-human primates and how remodeling of the NKB and kisspeptin signaling circuitry controlling GnRH neurons takes place during the progress of puberty. Importantly, the pubertal remodeling of kisspeptin and NKB signaling ensures efficient functions of the GnRH neurosecretory system that regulates sex-specific reproduction in primates.

Role of Kisspeptin and NKB in Puberty in Nonhuman Primates: Sex Differences.

To understand the roles of kisspeptin and neurokinin B (NKB) in puberty and sex differences in their involvement, we conducted a series of experiments measuring the release of gonadotropin-releasing hormone (GnRH) and kisspeptin in the median eminence of the hypothalamus in male and female monkeys throughout sexual development. Results indicate that kisspeptin-10 and the NKB agonist, senktide, stimulated GnRH release in males and females at the prepubertal and pubertal stages, but females are much more sensitive to kisspeptin signaling than males. Moreover, throughout the progress of puberty, major remodeling of kisspeptin and NKB signaling pathways for the regulation of GnRH release takes place. In females during puberty, reciprocal pathways (i.e., kisspeptin signaling mediated through NKB neurons and NKB signaling mediated through kisspeptin neurons) are established, to provide powerful and flexible mechanisms for GnRH neurosecretory activity necessary for complex female reproductive function in adulthood. By contrast, during puberty in males, reciprocal pathways are consolidated to a simpler kisspeptin-dominant signaling pathway. Nevertheless, in primates, both kisspeptin and NKB signaling are contributing factors for the pubertal increase in GnRH release, rather than initiating puberty.